All patents, patent applications and publications cited herein are hereby incorporated by reference in their entirety. The disclosures of these publications in their entireties are hereby incorporated by reference into this application in order to more fully describe the state of the art as known to those skilled therein as of the date of the invention described and claimed herein.
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Parkinson's disease (PD) is a degenerative disorder of the central nervous system. It results from the death of dopamine-containing cells in the substantia nigra, a region of the midbrain; the cause of cell-death is unknown. Early in the course of the disease, the most obvious symptoms are movement-related, including shaking, rigidity, slowness of movement and difficulty with walking and gait. Later, cognitive and behavioral problems may arise, with dementia commonly occurring in the advanced stages of the disease. Other symptoms include sensory, sleep and emotional problems. PD is more common in the elderly with most cases occurring after the age of 50.
Parkinson's disease is diagnosed by a physician exam, and diagnosis is based on the medical history and a neurological examination of the patient. There is no laboratory or molecular test that will clearly identify the disease. Brain scans are sometimes used to rule out disorders that could give rise to similar symptoms. Patients may be given levodopa, or other dopamine affecting agent, and resulting relief of motor impairment tends to confirm diagnosis. The finding of Lewy bodies in the midbrain on autopsy is usually considered proof that the patient suffered from Parkinson's disease. Thus there is need for biomarkers for PD disease or treatment.
Recent genome-wide association studies have linked common variants in the human genome to Parkinson's disease (PD) risk. In certain aspects, the invention describes that the consequences of variants at 2 such loci, PARK6 and LRRK2, are highly interrelated, both in terms of their broad impacts on human brain transcriptomes of unaffected carriers, and in terms of their associations with PD risk. Deficiency of the PARK16 locus gene RAB7L1 in primary rodent neurons, or of a RAB7L1 orthologue in Drosophila dopamine neurons, recapitulated degeneration observed with expression of a familial PD mutant form of LRRK2, whereas RAB7L1 overexpression rescued the LRRK2 mutant phenotypes. PD-associated defects in RAB7L1 or LRRK2 led to endolysosomal and Golgi apparatus sorting defects and deficiency of the VPS35 component of the retromer complex. Expression of wild-type VPS35, but not a familial PD-associated mutant form, rescued these defects. Taken together, these studies implicate retromer and lysosomal pathway alterations in PD risk.
In certain aspects the invention provides that genetic variants at PARK16 and LRRK2 interact to modify Parkinson's disease risk.
In certain aspects the invention provides that splicing of the PARK16 locus gene RAB7L1 is modified by genetic variants.
In certain aspects the invention provides that RAB7L1 and LRRK2 coordinately regulate protein sorting through the retromer pathway.
In certain aspects the invention provides that expression of the retromer component VPS35 can suppress LRRK2 mutant pathology.
In certain aspects the invention provides human functional genomics combined with cell and animal model studies, to provide convergent evidence of a critical role for RAB7L1 at the PARK16 locus and of retromer pathway dysfunction in Parkinson's disease etiology.
In certain embodiments, the subject is suspected of or evaluated for having predisposition or risk to sporadic (non-familial) PD.
In certain aspects, the invention provides methods to determine risk or predisposition to develop PD in a subject in need thereof comprising: (a) providing a sample from a subject in need thereof, (b) determining the presence or absence of a genetic variant(s) at PARK16 and LRRK2 locus, and (c) comparing the genetic variant(s) at PARK16 and/or LRRK2 locus from the subject sample to the PARK16 and/or LRRK2 locus variant in a reference sample, wherein the reference sample is associated with a non-PD status. In certain embodiments, the methods further comprise determining whether the gene variant(s) lead to a deficiency of the PARK16 locus gene RAB7L1. In certain embodiments, the deficiency is reduced level of the full-length RAB7L.
The methods can determine the protein level of full-length RAB7L, the full-length RAB7L mRNA levels, or a combination thereof. In other embodiments, the methods can determine the level of VPS35 protein or mRNA, or a combination thereof. The methods can determine the protein level of full-length RAB7L, the full-length RAB7L mRNA levels, the full-length RAB7L mRNA levels, or a combination thereof.
In certain embodiments, the predisposition or risk that is determined is to sporadic (non-familial) PD.
In certain embodiments, the variants are associated with familial PD. In other embodiments, the variants are associated with sporadic PD.
In certain aspects, the invention provides methods to determine risk or predisposition to develop PD in a subject in need thereof comprising: (a) providing a sample from a subject in need thereof, (b) determining the presence or absence of a genetic variant(s) at the PARK16 locus gene RAB7L1, and (c) comparing the genetic variant(s) at PARK16 locus gene RAB7L1 from the subject sample to the PARK16 locus gene RAB7L1 variant(s) in a reference sample, wherein the reference sample is associated with a non-PD status. In certain embodiments, the genetic variant(s) at the PARK16 locus affect the PARK16 locus gene RAB7L1. In certain embodiments, the PARK16 locus gene variant(s) lead to a deficiency of the PARK16 locus gene RAB7L1.
In certain aspects, the invention provides methods to determine a risk or predisposition to develop PD in a subject in need thereof comprising: (a) providing a sample from a subject in need thereof, (b) determining the level of full-length RAB7L, and (c) comparing the level of full-length RAB7L from the subject sample to the full-length RAB7L1 level in a reference sample, wherein the reference sample is associated in non-PD status, and wherein a reduced level of the full-length RAB7L is indicative of an increased risk or predisposition to PD. The methods can determine the protein level of full-length RAB7L, the full-length RAB7L mRNA levels, or a combination thereof. In certain embodiments, the methods comprise determining the full-length RAB7L1 level in a reference sample. In certain embodiments, the methods comprise determining whether the levels the full-length RAB7L1 level in the subject sample are reduced compared to these levels in a reference sample.
In certain aspects, the invention provides methods to determine a risk or predisposition to develop PD in a subject in need thereof comprising: (a) providing a sample from a subject in need thereof, (b) determining the level of VPS35 protein or mRNA, and (c) comparing the level of VPS35 protein or mRNA from the subject sample to the VPS35 protein or mRNA level in a reference sample, wherein the reference sample is associated in non-PD status, and wherein a reduced level of the VPS35 protein or mRNA is indicative of an increased risk or predisposition to PD. In certain embodiments, the methods comprise determining the level VPS35 protein or mRNA in a reference sample. In certain embodiments, the methods comprise determining whether the levels the VPS35 protein or mRNA level in the subject sample are reduced compared to these levels in a reference sample.
In certain embodiments, the methods determine protein or mRNA levels, or a combination thereof.
Certain PARK16 and/or LRRK2 locus variants, including but not limited to variants as described herein, are associated with increased PD risk. In certain embodiments, the PARK16 locus gene is RAB7L1. In certain embodiments, PARK16 and LRRK2 locus variants cooperatively determine PD risk. In certain embodiments, the effect of a risk associated variant at the LRRK2 locus is dependent (or correlated) on the presence of the risk variant at the PARK16 locus, and vice versa. In certain embodiments, there is a genetic interaction between PARK16 and LRRK2 locus variants that affects PD predisposition and risk.
In certain embodiments, the methods further comprise determining whether PD-associated variants or defects in RAB7L1 or LRRK2 lead to endolysosomal, Golgi apparatus sorting defects, deficiency of the VPS35 component of the retromer complex, or any combination thereof.
In certain aspects, the invention provides methods to determine risk or predisposition to develop PD in a subject in need thereof comprising: (a) providing a sample from a subject in need thereof, (b) determining the presence or absence of an endolysosomal, Golgi apparatus sorting defects, deficiency of the VPS35 component of the retromer complex, or any combination thereof, compared a reference sample, wherein the reference sample is associated with a non-PD status.
In certain embodiments, the splicing of the PARK16 locus gene RAB7L1 is modified by genetic variants and is associated with increased risk of PD. In certain embodiments, the PD-associated variants or defects in RAB7L1 or LRRK2 lead to endolysosomal, Golgi apparatus sorting defects, deficiency of the VPS35 component of the retromer complex, or any combination thereof.
In certain embodiments of the methods, the subject is diagnosed with PD and is not administered dopamine affecting agents (i.e. not treated for PD).
In certain embodiments of the methods, the subject is diagnosed by clinical symptoms, imaging of dopamine uptake, or combination thereof.
In certain embodiments, the methods comprise isolating nucleic acids from the subject's biological sample. In the instant methods, the subject's sample is a biological sample, including but not limited to a blood sample, plasma sample, serum, CSF, tissue, cell or any combination thereof. Methods to isolate nucleic acid sequences from biological samples are known in the art. Methods for quantitative determination of amount of nucleic acids in a biological sample are known in the art.
In certain embodiments, the methods comprise quantifying the nucleic acid levels of RAB7L1, VPS35, or any combination thereof, wherein the nucleic acid levels are quantified by RT-qPCR, or any other suitable method. In other embodiments, the methods comprise quantifying the protein levels of RAB7L1. VPS35, or any combination thereof. Methods to determine protein levels in a quantitative manner are known in the art.
In certain embodiments, the sample is a cerebro-spinal fluid (CSF) sample, blood sample, plasma, serum, or any other suitable sample, or any combination thereof.
The invention provides a kit comprising PCR primers to carry out the methods of any of the steps, may also include instructions to carry out steps (a), (b) and (c) of these methods.
A kit comprising at least one nucleic acid, for example but not limited to a primer or a probe, to selectively quantify the levels of RAB7L1. VPS35, or any combination thereof, so as to determine the levels of RAB7L1. VPS3, and instructions to carry out steps (a) and (b) of the method of any of the methods.
In certain aspects, the invention provides methods for treating PD, comprising administering to a subject in need thereof a therapeutic amount of the retromer component VPS35.
An aspect of the invention provides for a method of treating Parkinson's Disease (PD) in a subject. In one embodiment, the method comprises determining the presence or absence of a genetic variant at the PARK16 and LRRK2 loci in a sample from a subject, wherein the presence of a PD-associated genetic variant at both the PARK16 and LRRK2 loci in the subject sample indicates the subject has an increased risk or predisposition to PD; and administering a treatment if the subject has an increased risk or predisposition to PD. In one embodiment, the genetic variant at the PARK16 locus comprises a genetic variant in the RAB7L1 gene. In another embodiment, the genetic variant at the RAB7L1 gene is SNP rs1572931. In a further embodiment, the PD-associated genetic variant at the PARK16 locus comprises a guanine (G) nucleotide at SNP rs1572931. In some embodiments, the PD-associated genetic variant at the PARK16 locus encodes a RAB7L1 mRNA, wherein exon 2 is excluded from the RAB7L1 mRNA sequence. In other embodiments, the the PD-associated genetic variant comprises SEQ ID NO: 5. In further embodiments, the PD-associated genetic variant at the PARK16 locus results in loss of expression of a RAB7L1 protein. In some embodiments, the genetic variant at the LRRK2 locus comprises SNP rs11176052. In other embodiments, the PD-associated genetic variant at the LRRK2 locus encodes the protein of SEQ ID NO: 27 or 28. In yet further embodiments, the PD-associated genetic variant at the LRKK2 locus results in loss of expression of a LRKK2 protein. In one embodiment, the treatment comprises administering to the subject an effective amount of a nucleic acid encoding a protein comprising 90% of SEQ ID NO: 6, SEQ ID NO: 26, SEQ ID NO: 11, SEQ ID NO: 14, or a combination or fragment thereof. In some embodiments, the treatment comprises administering to the subject an effective amount of a protein comprising 90% of SEQ ID NO: 6, SEQ ID NO: 26, SEQ ID NO: 11, SEQ ID NO: 14, or a combination or fragment thereof. In further embodiments, the PD disease status is determined by any suitable method, including but not limited to a physical examination of the subject, a neurological examination of the subject, a brain scan, or a combination thereof. In another embodiment, the subject is not diagnosed with PD. In yet other embodiments, the method further comprises a physical examination of the subject, a neurological examination of the subject, a brain scan, or a combination thereof. In some embodiments, the subject is suspected of having PD or is at risk of developing PD based on the presence of any one of parkinsonism symptoms. In further embodiments, the sample is a CSF sample, blood sample, plasma sample, serum sample or any combination thereof.
An aspect of the invention provides for a method of treating Parkinson's Disease (PD) in a subject. In one embodiment, the method comprises determining the presence or absence of a genetic variant at the PARK16 and LRRK2 loci in a sample from a subject, wherein the presence of a PD-associated genetic variant at both the PARK16 and LRRK2 loci in the subject sample indicates the subject has an increased risk or predisposition to PD; and administering a treatment if the subject has an increased risk or predisposition to PD, wherein the treatment comprises administering to the subject an effective amount of a protein comprising 90% of SEQ ID NO: 6. SEQ ID NO: 26, SEQ ID NO: 11. SEQ ID NO: 14, or a combination or fragment thereof. In one embodiment, the genetic variant at the PARK16 locus comprises a genetic variant in the RAB7L1 gene. In another embodiment, the genetic variant at the RAB7L1 gene is SNP rs1572931. In a further embodiment, the PD-associated genetic variant at the PARK16 locus comprises a guanine (G) nucleotide at SNP rs1572931. In some embodiments, the PD-associated genetic variant at the PARK16 locus encodes a RAB7L1 mRNA, wherein exon 2 is excluded from the RAB7L1 mRNA sequence. In other embodiments, the the PD-associated genetic variant comprises SEQ ID NO: 5. In further embodiments, the PD-associated genetic variant at the PARK16 locus results in loss of expression of a RAB7L1 protein. In some embodiments, the genetic variant at the LRRK2 locus comprises SNP rs11176052. In other embodiments, the PD-associated genetic variant at the LRRK2 locus encodes the protein of SEQ ID NO: 27 or 28. In yet further embodiments, the PD-associated genetic variant at the LRKK2 locus results in loss of expression of a LRKK2 protein. In further embodiments, the PD disease status is determined by any suitable method, including but not limited to a physical examination of the subject, a neurological examination of the subject, a brain scan, or a combination thereof. In another embodiment, the subject is not diagnosed with PD. In yet other embodiments, the method further comprises a physical examination of the subject, a neurological examination of the subject, a brain scan, or a combination thereof. In some embodiments, the subject is suspected of having PD or is at risk of developing PD based on the presence of any one of parkinsonism symptoms. In further embodiments, the sample is a CSF sample, blood sample, plasma sample, serum sample or any combination thereof.
An aspect of the invention provides for a method of treating Parkinson's Disease (PD) in a subject. In one embodiment, the method comprises determining the presence or absence of a genetic variant at the PARK16 and LRRK2 loci in a sample from a subject, wherein the presence of a PD-associated genetic variant at both the PARK16 and LRRK2 loci in the subject sample indicates the subject has an increased risk or predisposition to PD; and administering a treatment if the subject has an increased risk or predisposition to PD, wherein the treatment comprises administering to the subject an effective amount of a nucleic acid encoding a protein comprising 90% of SEQ ID NO: 6, SEQ ID NO: 26. SEQ ID NO: 11, SEQ ID NO: 14, or a combination or fragment thereof. In one embodiment, the genetic variant at the PARK16 locus comprises a genetic variant in the RAB7L1 gene. In another embodiment, the genetic variant at the RAB7L1 gene is SNP rs1572931. In a further embodiment, the PD-associated genetic variant at the PARK16 locus comprises a guanine (G) nucleotide at SNP rs1572931. In some embodiments, the PD-associated genetic variant at the PARK16 locus encodes a RAB7L1 mRNA, wherein exon 2 is excluded from the RAB7L1 mRNA sequence. In other embodiments, the the PD-associated genetic variant comprises SEQ ID NO: 5. In further embodiments, the PD-associated genetic variant at the PARK16 locus results in loss of expression of a RAB7L1 protein. In some embodiments, the genetic variant at the LRRK2 locus comprises SNP rs11176052. In other embodiments, the PD-associated genetic variant at the LRRK2 locus encodes the protein of SEQ ID NO: 27 or 28. In yet further embodiments, the PD-associated genetic variant at the LRKK2 locus results in loss of expression of a LRKK2 protein. In further embodiments, the PD disease status is determined by any suitable method, including but not limited to a physical examination of the subject, a neurological examination of the subject, a brain scan, or a combination thereof. In another embodiment, the subject is not diagnosed with PD. In yet other embodiments, the method further comprises a physical examination of the subject, a neurological examination of the subject, a brain scan, or a combination thereof. In some embodiments, the subject is suspected of having PD or is at risk of developing PD based on the presence of any one of parkinsonism symptoms. In further embodiments, the sample is a CSF sample, blood sample, plasma sample, serum sample or any combination thereof.
An aspect of the invention provides for a method of treating Parkinson's Disease (PD) in a subject. In one embodiment, the method comprises determining the presence or absence of a genetic variant at the LRRK2 locus in a sample from a subject, wherein the presence of a PD-associated genetic variant at the LRRK2 locus in the subject sample indicates the subject has an increased risk or predisposition to PD; and administering a treatment if the subject has an increased risk or predisposition to PD. In some embodiments, the genetic variant at the LRRK2 locus comprises SNP rs11176052. In other embodiments, the PD-associated genetic variant at the LRRK2 locus encodes the protein of SEQ ID NO: 27 or 28. In yet further embodiments, the PD-associated genetic variant at the LRKK2 locus results in loss of expression of a LRKK2 protein. In further embodiments, the treatment comprises administering to the subject an effective amount of a nucleic acid encoding a protein comprising 90% of SEQ ID NO: 6, SEQ ID NO: 26, SEQ ID NO: 14, or a combination or fragment thereof. In some embodiments, the treatment comprises administering to the subject an effective amount of a protein comprising 90% of SEQ ID NO: 6, SEQ ID NO: 26, SEQ ID NO: 14, or a combination or fragment thereof. In further embodiments, the PD disease status is determined by any suitable method, including but not limited to a physical examination of the subject, a neurological examination of the subject, a brain scan, or a combination thereof. In another embodiment, the subject is not diagnosed with PD. In yet other embodiments, the method further comprises a physical examination of the subject, a neurological examination of the subject, a brain scan, or a combination thereof. In some embodiments, the subject is suspected of having PD or is at risk of developing PD based on the presence of any one of parkinsonism symptoms. In further embodiments, the sample is a CSF sample, blood sample, plasma sample, serum sample or any combination thereof.
An aspect of the invention provides for a method of treating Parkinson's Disease (PD) in a subject. In one embodiment, the method comprises determining the presence or absence of a genetic variant at the LRRK2 locus in a sample from a subject, wherein the presence of a PD-associated genetic variant at the LRRK2 locus in the subject sample indicates the subject has an increased risk or predisposition to PD; and administering a treatment if the subject has an increased risk or predisposition to PD, wherein the treatment comprises administering to the subject an effective amount of a nucleic acid encoding a protein comprising 90%/o of SEQ ID NO: 6. SEQ ID NO: 26, SEQ ID NO: 14, or a combination or fragment thereof. In some embodiments, the genetic variant at the LRRK2 locus comprises SNP rs11176052. In other embodiments, the PD-associated genetic variant at the LRRK2 locus encodes the protein of SEQ ID NO: 27 or 28. In yet further embodiments, the PD-associated genetic variant at the LRKK2 locus results in loss of expression of a LRKK2 protein. In further embodiments, the PD disease status is determined by any suitable method, including but not limited to a physical examination of the subject, a neurological examination of the subject, a brain scan, or a combination thereof. In another embodiment, the subject is not diagnosed with PD. In yet other embodiments, the method further comprises a physical examination of the subject, a neurological examination of the subject, a brain scan, or a combination thereof. In some embodiments, the subject is suspected of having PD or is at risk of developing PD based on the presence of any one of parkinsonism symptoms. In further embodiments, the sample is a CSF sample, blood sample, plasma sample, serum sample or any combination thereof.
An aspect of the invention provides for a method of treating Parkinson's Disease (PD) in a subject. In one embodiment, the method comprises determining the presence or absence of a genetic variant at the LRRK2 locus in a sample from a subject, wherein the presence of a PD-associated genetic variant at the LRRK2 locus in the subject sample indicates the subject has an increased risk or predisposition to PD; and administering a treatment if the subject has an increased risk or predisposition to PD, wherein the treatment comprises administering to the subject an effective amount of a protein comprising 90% of SEQ ID NO: 6, SEQ ID NO: 26, SEQ ID NO: 14, or a combination or fragment thereof. In some embodiments, the genetic variant at the LRRK2 locus comprises SNP rs11176052. In other embodiments, the PD-associated genetic variant at the LRRK2 locus encodes the protein of SEQ ID NO: 27 or 28. In yet further embodiments, the PD-associated genetic variant at the LRKK2 locus results in loss of expression of a LRKK2 protein. In further embodiments, the PD disease status is determined by any suitable method, including but not limited to a physical examination of the subject, a neurological examination of the subject, a brain scan, or a combination thereof. In another embodiment, the subject is not diagnosed with PD. In yet other embodiments, the method further comprises a physical examination of the subject, a neurological examination of the subject, a brain scan, or a combination thereof. In some embodiments, the subject is suspected of having PD or is at risk of developing PD based on the presence of any one of parkinsonism symptoms. In further embodiments, the sample is a CSF sample, blood sample, plasma sample, serum sample or any combination thereof.
An aspect of the invention provides for a method of treating Parkinson's Disease (PD) in a subject. In one embodiment, the method comprises determining the presence or absence of a genetic variant at the PARK16 locus in a sample from a subject, wherein the presence of a PD-associated genetic variant at the PARK16 locus in the subject sample indicates the subject has an increased risk or predisposition to PD; and administering a treatment if the subject has an increased risk or predisposition to PD. In one embodiment, the genetic variant at the PARK16 locus comprises a genetic variant in the RAB7L1 gene. In another embodiment, the genetic variant at the RAB7L1 gene is SNP rs1572931. In a further embodiment, the PD-associated genetic variant at the PARK16 locus comprises a guanine (G) nucleotide at SNP rs1572931. In some embodiments, the PD-associated genetic variant at the PARK16 locus encodes a RAB7L1 mRNA, wherein exon 2 is excluded from the RAB7L1 mRNA sequence. In other embodiments, the the PD-associated genetic variant comprises SEQ ID NO: 5. In further embodiments, the PD-associated genetic variant at the PARK16 locus results in loss of expression of a RAB7L1 protein. In one embodiment, the treatment comprises administering to the subject an effective amount of a nucleic acid encoding a protein comprising 90% of SEQ ID NO: 11, SEQ ID NO: 14, or a combination or fragment thereof. In another embodiment, the treatment comprises administering to the subject an effective amount of a protein comprising 90% of SEQ ID NO: 1, SEQ ID NO: 14, or a combination or fragment thereof. In further embodiments, the PD disease status is determined by any suitable method, including but not limited to a physical examination of the subject, a neurological examination of the subject, a brain scan, or a combination thereof. In another embodiment, the subject is not diagnosed with PD. In yet other embodiments, the method further comprises a physical examination of the subject, a neurological examination of the subject, a brain scan, or a combination thereof. In some embodiments, the subject is suspected of having PD or is at risk of developing PD based on the presence of any one of parkinsonism symptoms. In further embodiments, the sample is a CSF sample, blood sample, plasma sample, serum sample or any combination thereof.
An aspect of the invention provides for a method of treating Parkinson's Disease (PD) in a subject. In one embodiment, the method comprises determining the presence or absence of a genetic variant at the PARK16 locus in a sample from a subject, wherein the presence of a PD-associated genetic variant at the PARK16 locus in the subject sample indicates the subject has an increased risk or predisposition to PD; and administering a treatment if the subject has an increased risk or predisposition to PD, wherein the treatment comprises administering to the subject an effective amount of a nucleic acid encoding a protein comprising 90% of SEQ ID NO: 11, SEQ ID NO: 14, or a combination or fragment thereof. In one embodiment, the genetic variant at the PARK16 locus comprises a genetic variant in the RAB7L1 gene. In another embodiment, the genetic variant at the RAB7L1 gene is SNP rs1572931. In a further embodiment, the PD-associated genetic variant at the PARK16 locus comprises a guanine (G) nucleotide at SNP rs1572931. In some embodiments, the PD-associated genetic variant at the PARK16 locus encodes a RAB7L1 mRNA, wherein exon 2 is excluded from the RAB7L mRNA sequence. In other embodiments, the the PD-associated genetic variant comprises SEQ ID NO: 5. In further embodiments, the PD-associated genetic variant at the PARK16 locus results in loss of expression of a RAB7L1 protein. In further embodiments, the PD disease status is determined by any suitable method, including but not limited to a physical examination of the subject, a neurological examination of the subject, a brain scan, or a combination thereof. In another embodiment, the subject is not diagnosed with PD. In yet other embodiments, the method further comprises a physical examination of the subject, a neurological examination of the subject, a brain scan, or a combination thereof. In some embodiments, the subject is suspected of having PD or is at risk of developing PD based on the presence of any one of parkinsonism symptoms. In further embodiments, the sample is a CSF sample, blood sample, plasma sample, serum sample or any combination thereof.
An aspect of the invention provides for a method of treating Parkinson's Disease (PD) in a subject. In one embodiment, the method comprises determining the presence or absence of a genetic variant at the PARK16 locus in a sample from a subject, wherein the presence of a PD-associated genetic variant at the PARK16 locus in the subject sample indicates the subject has an increased risk or predisposition to PD; and administering a treatment if the subject has an increased risk or predisposition to PD, wherein the treatment comprises administering to the subject an effective amount of a protein comprising 90% of SEQ ID NO: 11, SEQ ID NO: 14, or a combination or fragment thereof. In one embodiment, the genetic variant at the PARK16 locus comprises a genetic variant in the RAB7L11 gene. In another embodiment, the genetic variant at the RAB7L1 gene is SNP rs1572931. In a further embodiment, the PD-associated genetic variant at the PARK16 locus comprises a guanine (G) nucleotide at SNP rs1572931. In some embodiments, the PD-associated genetic variant at the PARK6 locus encodes a RAB7L1 mRNA, wherein exon 2 is excluded from the RAB7L1 mRNA sequence. In other embodiments, the the PD-associated genetic variant comprises SEQ ID NO: 5. In further embodiments, the PD-associated genetic variant at the PARK16 locus results in loss of expression of a RAB7L1 protein. In further embodiments, the PD disease status is determined by any suitable method, including but not limited to a physical examination of the subject, a neurological examination of the subject, a brain scan, or a combination thereof. In another embodiment, the subject is not diagnosed with PD. In yet other embodiments, the method further comprises a physical examination of the subject, a neurological examination of the subject, a brain scan, or a combination thereof. In some embodiments, the subject is suspected of having PD or is at risk of developing PD based on the presence of any one of parkinsonism symptoms. In further embodiments, the sample is a CSF sample, blood sample, plasma sample, serum sample or any combination thereof.
An aspect of the invention provides for a method of treating PD in a subject. In one embodiment, the method comprises measuring the expression levels of a set of genes in a sample from a subject, wherein the set of genes comprises at least one gene selected from the genes listed in Table 2; comparing the expression levels of the set of genes in the subject sample to expression levels of the same set of genes in a reference sample or samples, wherein the reference sample or samples are from an individual who has a PD-associated SNP, and wherein similar expression levels of the set of genes in the subject sample and the set of genes in the reference sample(s) indicates the subject has an increased risk or predisposition to PD; and administering a treatment if the subject has an increased risk or predisposition to PD. In one embodiment, the treatment comprises administering to the subject an effective amount of a nucleic acid encoding a protein comprising 90% of SEQ ID NO: 6, SEQ ID NO: 26, SEQ ID NO: 11, SEQ ID NO: 14, or a combination or fragment thereof. In some embodiments, the treatment comprises administering to the subject an effective amount of a protein comprising 90% of SEQ ID NO: 6, SEQ ID NO: 26, SEQ ID NO: 11, SEQ ID NO: 14, or a combination or fragment thereof. In further embodiments, the PD disease status is determined by any suitable method, including but not limited to a physical examination of the subject, a neurological examination of the subject, a brain scan, or a combination thereof. In another embodiment, the subject is not diagnosed with PD. In yet other embodiments, the method further comprises a physical examination of the subject, a neurological examination of the subject, a brain scan, or a combination thereof. In some embodiments, the subject is suspected of having PD or is at risk of developing PD based on the presence of any one of parkinsonism symptoms. In further embodiments, the sample is a CSF sample, blood sample, plasma sample, serum sample or any combination thereof.
An aspect of the invention provides a method of treating PD in a subject. In one embodiment, the method comprises determining a level of full-length RAB7L1 in a sample from a subject; comparing the level of full-length RAB7L1 from the subject sample to a full-length RAB7L1 level in a reference sample, wherein the reference sample is associated with a non-PD status, and wherein a reduced level of the full-length RAB7L in the subject sample indicates the subject has an increased risk or predisposition to PD; and administering a treatment if the subject has an increased risk or predisposition to PD. In one embodiment, the method comprises the level of full-length RAB7L is protein level of full-length RAB7L, or mRNA levels of the full-length RAB7L, or a combination thereof. In one embodiment, the treatment comprises administering to the subject an effective amount of a nucleic acid encoding a protein comprising 90% of SEQ ID NO: 6, SEQ ID NO: 26, SEQ ID NO: 11, SEQ ID NO: 14, or a combination or fragment thereof. In some embodiments, the treatment comprises administering to the subject an effective amount of a protein comprising 90% of SEQ ID NO: 6, SEQ ID NO: 26, SEQ ID NO: 1, SEQ ID NO: 14, or a combination or fragment thereof. In further embodiments, the PD disease status is determined by any suitable method, including but not limited to a physical examination of the subject, a neurological examination of the subject, a brain scan, or a combination thereof. In another embodiment, the subject is not diagnosed with PD. In yet other embodiments, the method further comprises a physical examination of the subject, a neurological examination of the subject, a brain scan, or a combination thereof. In some embodiments, the subject is suspected of having PD or is at risk of developing PD based on the presence of any one of parkinsonism symptoms. In further embodiments, the sample is a CSF sample, blood sample, plasma sample, serum sample or any combination thereof. In another embodiment, the method further comprises a step of sequencing nucleic acids isolated from the subject's sample to determine the presence or absence of a PD-risk associated SNP, wherein the presence of a PD-risk associated SNP is further indicative that the subject is at risk of developing PD or is suffering from PD.
An aspect of the invention provides for a method of treating Parkinson's Disease (PD) in a subject. In one embodiment, the method comprises determining a level of isoform 3 of RAB7L1 in a sample from a subject; comparing the level of isoform 3 of RAB7L1 from the subject sample to an isoform 3 of RAB7L1 level in a reference sample, wherein the reference sample is associated in non-PD status, and wherein an increased level of isoform 3 of RAB7L1 in the subject sample indicates the subject has an increased risk or predisposition to PD; and administering a treatment if the subject has an increased risk or predisposition to PD. In another embodiment, the level of isoform 3 of RAB7L1 is a protein level. In a further embodiment, the method further comprises determining the level of transcript variant 4, 5, or a combination thereof of RAB7L1. In one embodiment, the treatment comprises administering to the subject an effective amount of a nucleic acid encoding a protein comprising 90% of SEQ ID NO: 6, SEQ ID NO: 26, SEQ ID NO: 11. SEQ ID NO: 14, or a combination or fragment thereof. In some embodiments, the treatment comprises administering to the subject an effective amount of a protein comprising 90% of SEQ ID NO: 6, SEQ ID NO: 26, SEQ ID NO: 11, SEQ ID NO: 14, or a combination or fragment thereof. In further embodiments, the PD disease status is determined by any suitable method, including but not limited to a physical examination of the subject, a neurological examination of the subject, a brain scan, or a combination thereof. In another embodiment, the subject is not diagnosed with PD. In yet other embodiments, the method further comprises a physical examination of the subject, a neurological examination of the subject, a brain scan, or a combination thereof. In some embodiments, the subject is suspected of having PD or is at risk of developing PD based on the presence of any one of parkinsonism symptoms. In further embodiments, the sample is a CSF sample, blood sample, plasma sample, serum sample or any combination thereof. In another embodiment, the method further comprises a step of sequencing nucleic acids isolated from the subject's sample to determine the presence or absence of a PD-risk associated SNP, wherein the presence of a PD-risk associated SNP is further indicative that the subject is at risk of developing PD or is suffering from PD.
An aspect of the invention provides a method of treating Parkinson's Disease (PD) in a subject. In one embodiment, the method comprises determining a level of transcript variant 4, 5, or a combination thereof of RAB7L1 in a sample from a subject; comparing the level of transcript variant 4, 5, or a combination thereof of RAB7L1 from the subject sample to a transcript variant 4, 5, or a combination thereof of RAB7L1 level in a reference sample, wherein the reference sample is associated in non-PD status, and wherein an increased level of transcript variant 4, 5, or a combination thereof of RAB7L1 in the subject sample indicates the subject has an increased risk or predisposition to PD; and administering a treatment if the subject has an increased risk or predisposition to PD. In another embodiment, the level of transcript variant 4, 5 or a combination thereof of RAB7L1 is a mRNA level. In a further embodiment, the method further comprises determining the level of isoform 3 of RAB7L1. In one embodiment, the treatment comprises administering to the subject an effective amount of a nucleic acid encoding a protein comprising 90% of SEQ ID NO: 6, SEQ ID NO: 26. SEQ ID NO: 11, SEQ ID NO: 14, or a combination or fragment thereof. In some embodiments, the treatment comprises administering to the subject an effective amount of a protein comprising 90% of SEQ ID NO: 6, SEQ ID NO: 26, SEQ ID NO: 11, SEQ ID NO: 14, or a combination or fragment thereof. In further embodiments, the PD disease status is determined by any suitable method, including but not limited to a physical examination of the subject, a neurological examination of the subject, a brain scan, or a combination thereof. In another embodiment, the subject is not diagnosed with PD. In yet other embodiments, the method further comprises a physical examination of the subject, a neurological examination of the subject, a brain scan, or a combination thereof. In some embodiments, the subject is suspected of having PD or is at risk of developing PD based on the presence of any one of parkinsonism symptoms. In further embodiments, the sample is a CSF sample, blood sample, plasma sample, serum sample or any combination thereof. In another embodiment, the method further comprises a step of sequencing nucleic acids isolated from the subject's sample to determine the presence or absence of a PD-risk associated SNP, wherein the presence of a PD-risk associated SNP is further indicative that the subject is at risk of developing PD or is suffering from PD.
An aspect of the invention provides a method of treating Parkinson's Disease (PD) in a subject. In one embodiment, the method comprises determining a level of retromer components in a sample from a subject; comparing the level of retromer components from the subject sample to a retromer component level in a reference sample, wherein the reference sample is associated with a non-PD status, and wherein a reduced level of the retromer components in the subject sample indicates the subject has an increased risk or predisposition to PD; and administering a treatment if the subject has an increased risk or predisposition to PD. In another embodiment, the level of retromer component is protein level of retromer component, or mRNA levels of retromer component, or a combination thereof. In a further embodiment, the retromer component is VPS35, VPS29, VPS26 or a combination thereof. In some embodiments, the level of VPS35. VPS29, or VPS26 is protein level of VPS35, VPS29, or VPS26, or mRNA levels of VPS35. VPS29, or VPS26, or a combination thereof. In one embodiment, the treatment comprises administering to the subject an effective amount of a nucleic acid encoding a protein comprising 90% of SEQ ID NO: 6. SEQ ID NO: 26, SEQ ID NO: 11. SEQ ID NO: 14, or a combination or fragment thereof. In some embodiments, the treatment comprises administering to the subject an effective amount of a protein comprising 90% of SEQ ID NO: 6, SEQ ID NO: 26, SEQ ID NO: 11, SEQ ID NO: 14, or a combination or fragment thereof. In further embodiments, the PD disease status is determined by any suitable method, including but not limited to a physical examination of the subject, a neurological examination of the subject, a brain scan, or a combination thereof. In another embodiment, the subject is not diagnosed with PD. In yet other embodiments, the method further comprises a physical examination of the subject, a neurological examination of the subject, a brain scan, or a combination thereof. In some embodiments, the subject is suspected of having PD or is at risk of developing PD based on the presence of any one of parkinsonism symptoms. In further embodiments, the sample is a CSF sample, blood sample, plasma sample, serum sample or any combination thereof. In another embodiment, the method further comprises a step of sequencing nucleic acids isolated from the subject's sample to determine the presence or absence of a PD-risk associated SNP, wherein the presence of a PD-risk associated SNP is further indicative that the subject is at risk of developing PD or is suffering from PD.
An aspect of the invention provides for a composition for evaluating the existence of, or predisposition to, PD in a subject, said composition comprising polynucleotides or oligonucleotides, wherein each polynucleotide or oligonucleotide hybridizes to a gene, gene fragment, or gene transcript of at least two different markers in a subject sample, wherein the markers comprise LRRK2, RAB7L1 and VPS35.
An aspect of the invention provides for a composition for evaluating the existence of, or predisposition to, PD in a subject, said composition comprising polynucleotides or oligonucleotides, wherein each polynucleotide or oligonucleotide hybridizes to a gene, gene fragment, or gene transcript of a different marker in a subject sample, each marker being one of the genes listed in Table 2. In one embodiment, the composition comprises a microarray, a microfluidics card, a chip, or a chamber.
An aspect of the invention provides a kit for determining the levels of RAB7L1, LRRK2, VPS35, or a combination thereof, the kit comprising at least one oligonucleotide or polynucleotide to selectively quantify the levels of RAB7L1. LRRK2. VPS35, or a combination thereof. In one embodiment, the oligonucleotide or polynucleotide comprises SEQ ID NO: 15, 16, 17, or 18.
An aspect of the invention provides for a diagnostic kit for determining whether a sample from a subject exhibits a presence or absence of a PD-associated genetic variant, the kit comprising at least one oligonucleotide or polynucleotide for sequencing nucleic acids isolated from the subject's sample to determine the presence or absence of a PD-risk associated SNP, wherein the presence of a PD-risk associated SNP is further indicative that the subject is at risk of developing PD or is suffering from PD. In one embodiment, the oligonucleotide or polynucleotide comprises SEQ ID NO: 24, or 25.
An aspect of the invention provides for a diagnostic kit comprising the microarray, microfluidics card, chip, or chamber described herein.
An aspect of the invention provides for a synthetic nucleic acid comprising SEQ ID NO: 15, 16, 17, 18, 19, 24, or 25.
To conform to the requirements for PCT patent applications, many of the figures presented herein are black and white representations of images originally created in color, such as many of those figures based on immunofluorescence microscopy. In the below descriptions and the examples, this colored staining is described in terms of its appearance in black and white. For example, GFP staining which appeared green in the original appears as a grey stain when presented in black and white. The original color versions of
The singular forms “a,” “an,” and “the” include plural reference unless the context clearly dictates otherwise.
The term “about” is used herein to mean approximately, in the region of, roughly, or around. When the term “about” is used in conjunction with a numerical range, it modifies that range by extending the boundaries above and below the numerical values set forth. In general, the term “about” is used herein to modify a numerical value above and below the stated value by a variance of 20%.
Parkinson's disease (PD) is a common neurodegenerative disorder of aging, characterized by slowed movements and a distinctive tremor at rest (Lang and Lozano, 1998). Defining pathological features of the disease include neurodegeneration that is most prominent among midbrain dopamine neurons (DNs) in the Substantia Nigra (SN) and Lewy body protein aggregates that are composed in part of alpha-Synuclein (aSyn) protein. As the course of PD is thought to last decades, and as at the time of autopsy the vast majority of DNs are long lost, the molecular pursuit of initial etiological events has proven difficult.
In rare inherited familial forms of PD, specific causative mutations have been identified, and this has significantly advanced the field (Abeliovich and Beal, 2006; Hardy et al., 2006). For instance, autosomal dominantly inherited mutations in aSyn, including missense mutations and triplication of the locus, lead to a familial PD variant, implicating aSyn directly in the disease process. Another familial genetic cause of PD is the presence of autosomal dominantly inherited mutations in the Leucine rich-repeat kinase-2 (LRRK2) protein, which encodes a large multidomain protein with GTPase and kinase activities. Although the precise functions of aSyn and LRRK2 in neurons remain to be determined, both proteins have been broadly implicated in intraneuronal protein sorting. aSyn mutations have been reported to modify synaptic vesicle kinetics (Abeliovich et al., 2000) as well as trafficking to the Golgi apparatus in a variety of model systems (Cooper et al., 2006; Thayanidhi et al., 2010), whereas LRRK2 mutations are implicated in defective lysosomal protein degradation and macroautophagy, which is a cellular process that delivers cytosolic proteins and protein agregates to the lysosome (Dodson et al., 2012; Heo et al., 2010; MacLeod et al., 2006), and Golgi Apparatus integrity (Stafa et al., 2012). The recent identification of rare autosomal dominant familial PD mutations in VPS35 (Vilarino-Guell et al., 2011; Zimprich et al., 2011), which encodes a component of the retromer complex that guides protein sorting from the endosome-lysosome degradation pathway retrogradely to the Golgi Apparatus (Bonifacino and Hurley, 2008; Seaman, 2009; Seaman et al., 1998), suggests that defective protein sorting in vesicular compartments may play a role in PD.
Several genome-wide association studies (GWAS) have described common genetic variants (at single nucleotide polymorphisms; SNPs) that modify PD risk in non-familial ‘sporadic’ cases (Hamza et al., 2010; Simon-Sanchez et al., 2009). Strikingly, a subset of these common variants lie within genomic loci previously associated with familial disease, such as aSyn or LRRK2, supporting the notion that common pathogenic pathways underlie familial and sporadic forms of PD. However, mechanisms that underlie the impact of non-familial genetic loci on PD risk, or that relate the functions of such loci to familial PD genes, remain unclear.
Described herein is a series of human brain transcriptome, human genetic, and cell biological studies, that together implicate a PD-associated genetic and cellular pathway. RAB7L1—one of 5 genes within the PARK16 non-familial PD risk-associated locus—functions together with LRRK2 to impact non-familial PD risk in the human population. This genetic interaction is apparent even in unaffected individuals who carry both risk alleles, as quantified in terms of a broad transcriptomic analysis of brain gene expression. Similarly, these genes together modify neuronal survival and neurite integrity in model systems. At a cellular level, defects in this PD-associated RAB7L1-LRRK2 pathway lead to abnormal lysosomal structures and defective retromer complex function, that normally links the endolysosomal protein degradation system with the Golgi apparatus (Bonifacino and Hurley, 2008; Seaman. 2009; Seaman et al., 1998). Consistent with a role for such cellular defects in disease pathology, mutations in a retromer complex component, VPS35, have recently been associated with rare forms of autosomal dominantly inherited familial PD (Vilarino-Guell et al., 2011; Zimprich et al., 2011).
Molecules of the Invention
As used herein, a “RAB7L1 molecule” refers to a RAB7L1 protein, or a fragment thereof. A “RAB7L1 molecule” can also refer to a nucleic acid (including, for example, genomic DNA, complementary DNA (cDNA), synthetic DNA, as well as any form of corresponding RNA) which encodes a polypeptide corresponding to a RAB7L1 protein, or fragment thereof. For example, a RAB7L1 molecule can comprise the nucleic acid sequences shown in SEQ ID NOS: 1, 2, 3, 4, or 5, or comprise the amino acid sequences shown in SEQ ID NOS: 6, 7, 8, or 26. For example, a RAB7L1 molecule can be encoded by a recombinant nucleic acid encoding a RAB7L1 protein, or fragment thereof. The RAB7L1 molecules of the invention can be obtained from various sources and can be produced according to various techniques known in the art. For example, a nucleic acid that encodes a RAB7L1 molecule can be obtained by screening DNA libraries, or by amplification from a natural source. A RAB7L1 molecule can include a fragment or portion of a RAB7L1 protein. A RAB7L1 molecule can include a variant of the above described examples, such as a fragment thereof. Such a variant can comprise a naturally-occurring variant due to allelic variations between individuals (e.g., polymorphisms), mutated alleles, or alternative splicing forms (e.g. SEQ ID NOS: 2-5). In one embodiment, a RAB7L1 molecule is encoded by a nucleic acid variant of the nucleic acid having the sequence shown in SEQ ID NOS: 1, 2, 3, 4, or 5 wherein the variant has a nucleotide sequence identity to SEQ ID NOS: 1, 2, 3, 4, or 5 of at least about 70%, at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 91%, at least about 92%, at least about 93%, at least about 94%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, or at least about 99%. In another embodiment, a variant of the RAB7L1 protein comprises a protein or polypeptide encoded by a RAB7L1 nucleic acid sequence, such as the sequence shown in SEQ ID NOS: 1, 2, 3, 4, or 5.
As used herein, a “LRRK2 molecule” refers to a LRRK2 protein, or a fragment thereof. A “LRRK2 molecule” can also refer to a nucleic acid (including, for example, genomic DNA, complementary DNA (cDNA), synthetic DNA, as well as any form of corresponding RNA) which encodes a polypeptide corresponding to a LRRK2 protein, or fragment thereof. For example, a LRRK2 molecule can comprise the nucleic acid sequences shown in SEQ ID NOS: 9, or 10, or comprising the amino acid sequences shown in SEQ ID NO: 11, 27, or 28. For example, a LRRK2 molecule can be encoded by a recombinant nucleic acid encoding a LRRK2 protein, or fragment thereof. The LRRK2 molecules of the invention can be obtained from various sources and can be produced according to various techniques known in the art. For example, a nucleic acid that encodes a LRRK2 molecule can be obtained by screening DNA libraries, or by amplification from a natural source. A LRRK2 molecule can include a fragment or portion of a LRRK2 protein. A LRRK2 molecule can include a variant of the above described examples, such as a fragment thereof. Such a variant can comprise a naturally-occurring variant due to allelic variations between individuals (e.g., polymorphisms), mutated alleles, or alternative splicing forms. In one embodiment, a LRRK2 molecule is encoded by a nucleic acid variant of the nucleic acid having the sequence shown in SEQ ID NOS: 9, or 10 wherein the variant has a nucleotide sequence identity to SEQ ID NOS: 9 or 10 of at least about 70%, at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 91%, at least about 92%, at least about 93%, at least about 94%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, or at least about 99%. In another embodiment, a variant of the LRRK2 protein comprises a protein or polypeptide encoded by a LRRK2 nucleic acid sequence, such as the sequence shown in SEQ ID NOS: 9 or 10.
As used herein, a “VPS35 molecule” refers to a VPS35 protein, or a fragment thereof. A “VPS35 molecule” can also refer to a nucleic acid (including, for example, genomic DNA, complementary DNA (cDNA), synthetic DNA, as well as any form of corresponding RNA) which encodes a polypeptide corresponding to a VPS35 protein, or fragment thereof. For example, a VPS35 molecule can comprise the nucleic acid sequences shown in SEQ ID NOS: 12 or 13, or comprising the amino acid sequences shown in SEQ ID NO: 14. For example, a VPS35 molecule can be encoded by a recombinant nucleic acid encoding a VPS35 protein, or fragment thereof. The VPS35 molecules of the invention can be obtained from various sources and can be produced according to various techniques known in the art. For example, a nucleic acid that encodes a VPS35 molecule can be obtained by screening DNA libraries, or by amplification from a natural source. A VPS35 molecule can include a fragment or portion of a VPS35 protein. A VPS35 molecule can include a variant of the above described examples, such as a fragment thereof. Such a variant can comprise a naturally-occurring variant due to allelic variations between individuals (e.g., polymorphisms), mutated alleles, or alternative splicing forms. In one embodiment, a VPS35 molecule is encoded by a nucleic acid variant of the nucleic acid having the sequence shown in SEQ ID NOS: 12, or 13 wherein the variant has a nucleotide sequence identity to SEQ ID NOS: 12, or 13 of at least about 70%, at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 91%, at least about 92%, at least about 93%, at least about 94%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, or at least about 99%. In another embodiment, a variant of the VPS35 protein comprises a protein or polypeptide encoded by a VPS35 nucleic acid sequence, such as the sequence shown in SEQ ID NOS: 12 or 13.
The nucleic acid can be any type of nucleic acid, including genomic DNA, complementary DNA (cDNA), synthetic or semi-synthetic DNA, as well as any form of corresponding RNA. For example, a nucleic acid encoding a RAB7L1, a LRRK2, or a VPS35 protein can comprise a recombinant nucleic acid encoding such a protein. The nucleic acid can be a non-naturally occurring nucleic acid created artificially (such as by assembling, cutting, ligating or amplifying sequences). It can be double-stranded or single-stranded.
The invention further provides for nucleic acids that are complementary to a RAB7L1, a LRRK2, or a VPS35 molecule. Complementary nucleic acids can hybridize to the nucleic acid sequence described above under stringent hybridization conditions. Non-limiting examples of stringent hybridization conditions include temperatures above 30° C., above 35° C., in excess of 42° C., and/or salinity of less than about 500 mM, or less than 200 mM. Hybridization conditions can be adjusted by the skilled artisan via modifying the temperature, salinity and/or the concentration of other reagents such as SDS or SSC.
According to the invention, protein variants can include amino acid sequence modifications. For example, amino acid sequence modifications fall into one or more of three classes: substitutional, insertional or deletional variants. Insertions can include amino and/or carboxyl terminal fusions as well as intrasequence insertions of single or multiple amino acid residues. Insertions ordinarily will be smaller insertions than those of amino or carboxyl terminal fusions, for example, on the order of one to four residues. Deletions are characterized by the removal of one or more amino acid residues from the protein sequence. These variants ordinarily are prepared by site-specific mutagenesis of nucleotides in the DNA encoding the protein, thereby producing DNA encoding the variant, and thereafter expressing the DNA in recombinant cell culture. In one embodiment, a RAB7L1, a LRRK2, or a VPS35molecule can be modified with an amino acid sequence inserted as a carboxyl terminal fusion. For example, carboxyl terminal fusions may be used to increase the stability of a RAB7L1, a LRRK2, or a VPS35 molecule.
In one embodiment, a RAB7L1 molecule comprises a protein or polypeptide encoded by a nucleic acid sequence encoding a RAB7L1 protein, such as the sequences shown in SEQ ID NOS: 6, 7, 8, or 26. In another embodiment, the polypeptide can be modified, such as by glycosylations and/or acetylations and/or chemical reaction or coupling, and can contain one or several non-natural or synthetic amino acids. An example of a RAB7L1 molecule is the polypeptide having the amino acid sequence shown in SEQ ID NOS: 6, 7, 8, or 26. Such variants can include those having at least from about 46% to about 50% identity to SEQ ID NOS: 6, 7, 8, or 26 or having at least from about 50.1% to about 55% identity to SEQ ID NOS: 6, 7, 8, or 26, or having at least from about 55.1% to about 60% identity to SEQ ID NOS: 6, 7, 8, or 26, or having from at least about 60.1% to about 65% identity to SEQ ID NOS: 6, 7, 8, or 26, or having from about 65.1% to about 70% identity to SEQ ID NOS: 6, 7, 8, or 26, or having at least from about 70.1% to about 75% identity to SEQ ID NOS: 6, 7, 8, or 26, or having at least from about 75.1% to about 80% identity to SEQ ID NOS: 6, 7, 8, or 26, or having at least from about 80.1% to about 85% identity to SEQ ID NOS: 6, 7, 8, or 26, or having at least from about 85.1% to about 90% identity to SEQ ID NOS: 6, 7, 8, or 26, or having at least from about 90.1% to about 95% identity to SEQ ID NOS: 6, 7, 8, or 26, or having at least from about 95.1% to about 97% identity to SEQ ID NOS: 6, 7, 8, or 26, or having at least from about 97.1% to about 99% identity to SEQ ID NOS: 6, 7, 8, or 26. In another embodiment, a RAB7L1 molecule can be a fragment of a RAB7L1 protein.
In one embodiment, a LRRK2 molecule comprises a protein or polypeptide encoded by a nucleic acid sequence encoding a LRRK2 protein, such as the sequences shown in SEQ ID NOS: 11, 27, or 28. In another embodiment, the polypeptide can be modified, such as by glycosylations and/or acetylations and/or chemical reaction or coupling, and can contain one or several non-natural or synthetic amino acids. An example of a LRRK2 molecule is the polypeptide having the amino acid sequence shown in SEQ ID NOS: 11, 27, or 28. Such variants can include those having at least from about 46% to about 50% identity to SEQ ID NOS: 11, 27, or 28 or having at least from about 50.1% to about 55% identity to SEQ ID NOS: 11, 27, or 28, or having at least from about 55.1% to about 60% identity to SEQ ID NOS: 11, 27, or 28, or having from at least about 60.1% to about 65% identity to SEQ ID NOS: 11, 27, or 28, or having from about 65.1% to about 70% identity to SEQ ID NOS: 11, 27, or 28, or having at least from about 70.1% to about 75% identity to SEQ ID NOS: 11, 27, or 28, or having at least from about 75.1% to about 80% identity to SEQ ID NOS: 11, 27, or 28, or having at least from about 80.1% to about 85% identity to SEQ ID NOS: 11, 27, or 28, or having at least from about 85.1% to about 90% identity to SEQ ID NOS: 11, 27, or 28, or having at least from about 90.1% to about 95% identity to SEQ ID NOS: 11, 27, or 28, or having at least from about 95.1% to about 97% identity to SEQ ID NOS: 11, 27, or 28, or having at least from about 97.1% to about 99% identity to SEQ ID NOS: 11, 27, or 28. In another embodiment, a LRRK2 molecule can be a fragment of a LRRK2 protein.
In one embodiment, a VPS35 molecule comprises a protein or polypeptide encoded by a nucleic acid sequence encoding a VPS35 protein, such as the sequences shown in SEQ ID NO: 14. In another embodiment, the polypeptide can be modified, such as by glycosylations and/or acetylations and/or chemical reaction or coupling, and can contain one or several non-natural or synthetic amino acids. An example of a VPS35 molecule is the polypeptide having the amino acid sequence shown in SEQ ID NO: 14. Such variants can include those having at least from about 46% to about 50% identity to SEQ ID NO: 14 or having at least from about 50.1% to about 55% identity to SEQ ID NO: 14, or having at least from about 55.1% to about 60% identity to SEQ ID NO: 14, or having from at least about 60.1% to about 65% identity to SEQ ID NO: 14, or having from about 65.1% to about 70% identity to SEQ ID NO: 14, or having at least from about 70.1% to about 75% identity to SEQ ID NO: 14, or having at least from about 75.1% to about 80% identity to SEQ ID NO: 14, or having at least from about 80.1% to about 85% identity to SEQ ID NO: 14, or having at least from about 85.10% to about 90% identity to SEQ ID NO: 14, or having at least from about 90.1% to about 95% identity to SEQ ID NO: 14, or having at least from about 95.1% to about 97% identity to SEQ ID NO: 14, or having at least from about 97.1% to about 99% identity to SEQ ID NO: 14. In another embodiment, a VPS35 molecule can be a fragment of a VPS35 protein.
In one embodiment, a RAB7L1, a LRRK2, or a VPS35 molecule, according to the methods described herein can be administered to a subject as a recombinant protein. In another embodiment, a RAB7L1, a LRRK2, or a VPS35 molecule, can be administered to a subject as a modified recombinant protein. In a further embodiment, a RAB7L1, a LRRK2, or a VPS35 molecule, according to the methods described herein can be administered to a subject by delivery of a nucleic acid encoding a RAB7L1, a LRRK2, or a VPS35 protein, or fragment thereof. For example, nucleic acids can be delivered to a subject using a viral vector.
Polypeptides can be susceptible to denaturation or enzymatic degradation in the blood, liver or kidney. Accordingly, polypeptides can be unstable and have short biological half-lives. Polypeptides can be modified to increase their stability, for example, a fusion protein can be generated for increased stability and to cause a longer biological half-life to the polypeptides in circulation.
The term “biological half-life” is the time required for the activity of a substance taken into the body to lose one half its initial pharmacologic, physiologic, or biologic activity.
The invention provides for a nucleic acid encoding a RAB7L1 protein, or fragment thereof.
For example, the human genomic nucleotide sequence corresponding to the sense strand of the human RAB7L1 gene is depicted in SEQ ID NO: 1 (9752 bp). Sequence information related to RAB7L1 is accessible in public databases by GenBank Accession number NC_000001.10, 205737114, 205744615, complement (nucleotide).
SEQ ID NO: 1:
For example, the nucleotide sequence corresponding to the mRNA of the human RAB7L1 (transcript variant 1) is depicted in SEQ ID NO:2 (3324 bp), wherein the underscored bolded “ATG” denotes the beginning of the open reading frame. Nucleotides 1130-1238, 1526-1779, 4045-4116, 4959-5140, 5758-5879, and 6159-8626 of SEQ ID NO: 1 can be spliced together to form RAB7L1 (transcript variant 1). Sequence information related to RAB7L1 (transcript variant 1) is accessible in public databases by GenBank Accession number NM 003929.2 (nucleotide).
SEQ ID NO: 2:
For example, the nucleotide sequence corresponding to the mRNA of the human RAB7L1 (transcript variant 2) is depicted in SEQ ID NO: 3 (3223 bp), wherein the underscored bolded “ATG” denotes the beginning of the open reading frame. Nucleotides 1130-1238, 1526-1779, 4045-4116, 4959-5140, 5758-5879, 6159-8626 of SEQ ID NO: 1 can be spliced together to form RAB7L1 (transcript variant 2). Sequence information related to RAB7L1 (transcript variant 2) is accessible in public databases by GenBank Accession number NM_001135662.1 (nucleotide).
SEQ ID NO: 3:
tg
ggcagccg cgaccacctg ttcaaagtgc tggtggtggg ggacgccgca gtgggcaaga
For example, the nucleotide sequence corresponding to the mRNA of the human RAB7L1 (transcript variant 3) is depicted in SEQ ID NO: 4 (3438 bp), wherein the underscored bolded “ATG” denotes the beginning of the open reading frame. Nucleotides 1130-1779, 4959-5140, 5758-5879, 6159-8626 of SEQ ID NO: 1 can be spliced together to form RAB7L1 (transcript variant 3). Sequence information related to RAB7L1 (transcript variant 3) is accessible in public databases by GenBank Accession number NM_001135663.1 (nucleotide).
SEQ ID NO: 4:
For example, the nucleotide sequence corresponding to the mRNA of the human RAB7L1 (transcript variant 4) is depicted in SEQ ID NO: 5 (3070 bp), wherein the underscored bolded “ATG” denotes the beginning of the open reading frame. Nucleotides 1130-1339, 4045-4116, 4959-5140, 5758-5879, 6159-8626 of SEQ ID NO: 1 can be spliced together to form RAB7L1 (transcript variant 4). Sequence information related to RAB7L1 (transcript variant 4) is accessible in public databases by GenBank Accession number NM_001135664.1 (nucleotide).
SEQ ID NO: 5:
For example, other mRNA transcript variants of human RAB7L1 can exist. For example nucleotides 1130-1238, 4045-4116, 4959-5140, 5758-5879, 6159-8626 of SEQ ID NO: 1 can be spliced together to form RAB7L1 (transcript variant 5). Sequence information related to RAB7L1 transcript variants is accessible in public databases such as GenBank.
For example, the polypeptide sequence corresponding to human RAB7L1 (isoform 1) is encoded by the nucleic acid sequence of SEQ ID NOS: 2 or 3 and is depicted in SEQ ID NO: 6 (203aa). Sequence information related to RAB7L1 (isoform 1) is accessible in public databases by GenBank Accession numbers NP_003920.1 and NP_001129134.1 (protein).
SEQ ID NO: 6:
For example, the polypeptide sequence corresponding to human RAB7L1 (isoform 2) is encoded by the nucleic acid sequence of SEQ ID NO: 4 and is depicted in SEQ ID NO: 7 (179aa). Sequence information related to RAB7L1 (isoform 2) is accessible in public databases by GenBank Accession numbers NP_001123135.1 (protein).
SEQ ID NO: 7:
For example, the polypeptide sequence corresponding to human RAB7L1 (isoform 3) is encoded by the nucleic acid sequence of SEQ ID NO: 5 and is depicted in SEQ ID NO: 8 (131 aa). Sequence information related to RAB7L1 (isoform 3) is accessible in public databases by GenBank Accession numbers NP_001129136.1 (protein).
SEQ ID NO: 8:
The invention provides for a nucleic acid encoding a LRRK2 protein, or fragment thereof.
For example, the human genomic nucleotide sequence corresponding to the sense strand of the human LRRK2 gene is depicted in SEQ ID NO: 9 (144275 bp). Sequence information related to LRRK2 is accessible in public databases by GenBank Accession number NG_011709.1 (nucleotide).
SEQ ID NO: 9:
For example, the nucleotide sequence corresponding to the mRNA of the human LRRK2 is depicted in SEQ ID NO: 10 (9239 bp), wherein the underscored bolded “ATG” denotes the beginning of the open reading frame. Sequence information related to LRRK2 is accessible in public databases by GenBank Accession number NM_198578.3 (nucleotide).
SEQ ID NO: 10:
For example the polypeptide sequence corresponding to human LRRK2 is encoded by the nucleic acid sequence of SEQ ID NO: 10 and is depicted in SEQ ID NO: 11 (2527aa). Sequence information related to LRRK2 is accessible in public databases by GenBank Accession numbers NP_940980.3 (protein).
The invention provides for a nucleic acid encoding a VPS35 protein, or fragment thereof.
For example, the human genomic nucleotide sequence corresponding to the sense strand of the human VPS35 gene is depicted in SEQ ID NO: 12 (29556 bp). Sequence information related to VPS35 is accessible in public databases by GenBank Accession number NG_029970.1 (nucleotide).
SEQ ID NO: 12:
For example, the nucleotide sequence corresponding to the mRNA of the human VPS35 is depicted in SEQ ID NO: 13 (3298 bp), wherein the underscored bolded “ATG” denotes the beginning of the open reading frame. Sequence information related to LRRK2 VPS35 is accessible in public databases by GenBank Accession number NM_018206.4 (nucleotide).
SEQ ID NO: 13:
For example, the polypeptide sequence corresponding to human VPS35 is encoded by the nucleic acid sequence of SEQ ID NO: 13 and is depicted in SEQ ID NO: 14 (796aa). Sequence information related to VPS35 is accessible in public databases by GenBank Accession numbers NP_060676.2 (protein).
For example, the polypeptide sequence corresponding to human RAB7L1 (isoform 1) has a mutation wherein the amino acid at position 67 is a lysine (L) instead of a glutamine (Q) and is depicted in SEQ ID NO: 26 (203aa).
SEQ ID NO: 26:
For example, the polypeptide sequence corresponding to human LRRK2 has a mutation wherein the amino acid at position 2019 is a serine (S) instead of a glycine (G) and is depicted in SEQ ID NO: 27 (2527aa).
SEQ ID NO: 27:
For example, the polypeptide sequence corresponding to human LRRK2 has a mutation wherein the amino acid at position 1441 is a cysteine (C) instead of an arginine (R) and is depicted in SEQ ID NO: 28 (2527aa).
SEQ ID NO: 28:
A RAB7L1, a LRRK2, or a VPS35 molecule can also encompass ortholog genes, which are genes conserved among different biological species such as humans, dogs, cats, mice, and rats, that encode proteins (for example, homologs (including splice variants), mutants, and derivatives) having biologically equivalent functions as the human-derived protein. Orthologs of a RAB7L1, a LRRK2, or a VPS35 protein include any mammalian ortholog inclusive of the ortholog in humans and other primates, experimental mammals (such as mice, rats, hamsters and guinea pigs), mammals of commercial significance (such as horses, cows, camels, pigs and sheep), and also companion mammals (such as domestic animals, e.g., rabbits, ferrets, dogs, and cats). A RAB7L1, a LRRK2, or a VPS35 molecule can comprise a protein encoded by a nucleic acid sequence homologous to the human nucleic acid, wherein the nucleic acid is found in a different species and wherein that homolog encodes a protein similar to a RAB7L1, a LRRK2, or a VPS35 protein.
The invention utilizes conventional molecular biology, microbiology, and recombinant DNA techniques available to one of ordinary skill in the art. Such techniques are well known to the skilled worker and are explained fully in the literature. See, e.g., Maniatis, Fritsch & Sambrook, “DNA Cloning: A Practical Approach.” Volumes I and II (D. N. Glover, ed., 1985); “Oligonucleotide Synthesis” (M. J. Gait, ed., 1984); “Nucleic Acid Hybridization” (B. D. Hames & S. J. Higgins, eds., 1985); “Transcription and Translation” (B. D. Hames & S. J. Higgins, eds., 1984); “Animal Cell Culture” (R. I. Freshney, ed., 1986); “Immobilized Cells and Enzymes” (IRL Press, 1986): B. Perbal, “A Practical Guide to Molecular Cloning” (1984), and Sambrook, et al., “Molecular Cloning: a Laboratory Manual” (2001).
One skilled in the art can obtain RAB7L1, a LRRK2, or a VPS35 molecule, in several ways, which include, but are not limited to, isolating the protein via biochemical means or expressing a nucleotide sequence encoding the protein of interest by genetic engineering methods.
The invention provides for a RAB7L1, a LRRK2, or a VPS35 molecule that are encoded by nucleotide sequences. The RAB7L1. LRRK2, or VPS35molecule can be a polypeptide encoded by a nucleic acid (including genomic DNA, complementary DNA (cDNA), synthetic DNA, as well as any form of corresponding RNA). For example, a RAB7L1, a LRRK2, or a VPS35 molecule can be encoded by a recombinant nucleic acid encoding a human RAB7L1, a human LRRK2, or a human VPS35 protein, or fragment thereof. The RAB7L1, LRRK2, or VPS35 molecules of the invention can be obtained from various sources and can be produced according to various techniques known in the art. For example, a nucleic acid that encodes a RAB7L1, a LRRK2, or a VPS35 molecule can be obtained by screening DNA libraries, or by amplification from a natural source. The RAB7L1, LRRK2, or VPS35 molecule of the invention can be produced via recombinant DNA technology and such recombinant nucleic acids can be prepared by conventional techniques, including chemical synthesis, genetic engineering, enzymatic techniques, or a combination thereof. A RAB7L1, a LRRK2, or a VPS35 molecule of this invention can also encompasses variants of the human RAB7L1, LRRK2, or VPS35 proteins. The variants can comprise naturally-occurring variants due to allelic variations between individuals (e.g., polymorphisms), mutated alleles, or alternative splicing forms.
In one embodiment, a fragment of a nucleic acid sequence that comprises a RAB7L1, a LRRK2, or a VPS35 molecule can encompass any portion of at least about 8 consecutive nucleotides of SEQ ID NO: 1, 2, 3, 4, 5, 9, 10, 12, or 13. In one embodiment, the fragment can comprise at least about 10 nucleotides, at least about 15 nucleotides, at least about 20 nucleotides, or at least about 30 nucleotides of SEQ ID NO: 1, 2, 3, 4, 5, 9, 10, 12, or 13. Fragments include all possible nucleotide lengths between about 8 and about 100 nucleotides, for example, lengths between about 15 and about 100 nucleotides, or between about 20 and about 100 nucleotides.
A RAB7L1, a LRRK2, or a VPS35 molecule, can be a fragment of a RAB7L1, a LRRK2, or a VPS35 protein. For example, the RAB7L1, LRRK2, or VPS35 protein fragment can encompass any portion of at least about 8 consecutive amino acids of SEQ ID NO: 6, 7, 8, 1, 14, 26, 27, or 28. The fragment can comprise at least about 10 consecutive amino acids, at least about 20 consecutive amino acids, at least about 30 consecutive amino acids, at least about 40 consecutive amino acids, a least about 50 consecutive amino acids, at least about 60 consecutive amino acids, at least about 70 consecutive amino acids, at least about 80 consecutive amino acids, at least about 90 consecutive amino acids, at least about 100 consecutive amino acids, at least about 110 consecutive amino acids, or at least about 120 consecutive amino acids of SEQ ID NOS: 6, 7, 8, 11, 14, 26, 27, or 28. Fragments include all possible amino acid lengths between about 8 and 80 about amino acids, for example, lengths between about 10 and about 80 amino acids, between about 15 and about 80 amino acids, between about 20 and about 80 amino acids, between about 35 and about 80 amino acids, between about 40 and about 80 amino acids, between about 50 and about 80 amino acids, or between about 70 and about 80 amino acids.
Methods of Treating Parkinson's Disease
In one aspect, the invention provides a method of treating Parkinson's Disease (PD) in a subject comprising: (a) determining the presence or absence of a genetic variant at the PARK16 and LRRK2 loci in a sample from a subject, wherein the presence of a PD-associated genetic variant at both the PARK16 and LRRK2 loci in the subject sample indicates the subject has an increased risk or predisposition to PD, and (b) administering a treatment if the subject has an increased risk or predisposition to PD.
In another aspect, the invention provides a method of treating Parkinson's Disease (PD) in a subject comprising: (a) determining the presence or absence of a genetic variant at the LRRK2 locus in a sample from a subject, wherein the presence of a PD-associated genetic variant at the LRRK2 locus in the subject sample indicates the subject has an increased risk or predisposition to PD, and (b) administering a treatment if the subject has an increased risk or predisposition to PD.
In another aspect, the invention provides a method of treating Parkinson's Disease (PD) in a subject comprising: (a) determining the presence or absence of a genetic variant at the PARK16 locus in a sample from a subject, wherein the presence of a PD-associated genetic variant at the PARK16 locus in the subject sample indicates the subject has an increased risk or predisposition to PD, and (b) administering a treatment if the subject has an increased risk or predisposition to PD.
As used herein. “single-nucleotide polymorphism” or “SNP” refers to variations at single-nucleotide positions in the DNA sequence among individuals. Information on SNPs can be found in publically accessible databases, such as, in the SNP database at the National Center for Biotechnology Information (NCBI) (http://www.ncbi.nlm.nih.gov/). In one embodiment, the genetic variant at the PARK 16 locus comprises single-nucleotide polymorphism (SNP) rs823114, SNP rs823154, SNP rs823128, SNP rs947211, or a combination thereof.
In one embodiment, the PARK16 locus comprises the genes SLC45A3, NUCKS1, RAB7L1, SLC41A1, and PM20D1. In one embodiment, the genetic variant at the PARK 16 locus comprises a genetic variant in the RAB7L1 gene. In another embodiment, the genetic variant at the PARK 16 locus comprises a genetic variant at the SLC45A3, NUCKS1, SLC41A1, or PM20D1 gene. In one embodiment, the genetic variant at the RAB7L1 gene is SNP rs1572931.
Without being bound by theory, genetic variants can be associated with PD. In one embodiment, the PD-associated genetic variant at the PARK16 locus comprises a guanine (G) nucleotide at SNP rs1572931.
Genetic variants can also affect the splicing of mRNA. Without being bound by theory, pre-mRNA transcribed from genomic DNA can be spliced so that introns are removed and exons are joined together. Transcribed pre-mRNA can be alternatively spliced creating a range of unique proteins (known as “isoforms”) and/or mRNAs (known as “transcript variants”) by varying the exon composition of the mRNA. In one embodiment, the PD-associated genetic variant at the PARK16 locus encodes a RAB7L1 mRNA, wherein exon 2 is excluded from the RAB7L1 mRNA sequence. In one embodiment, the PD-associated genetic variant at the PARK16 locus results in loss of expression of a RAB7L1 protein. Various mutations that affect the transcription and translation of a RAB7L1 molecule can result in loss of expression of a RAB7L1 protein.
In one embodiment, the genetic variant at the LRRK2 locus comprises SNP rs1176052. In another embodiment, the PD-associated genetic variant at the LRRK2 locus encodes the protein of SEQ ID NO: 27 or 28. In another embodiment, the protein of SEQ ID NO: 27 or 28 is associated with familial PD. In another embodiment, the genetic variant at the LRRK2 locus is associated with sporadic, or non-familial PD.
In one embodiment, the PD-associated genetic variant at the LRKK2 locus results in loss of expression of a LRKK2 protein. Various mutations that affect the transcription and translation of a LRRK2 molecule can result in loss of expression of a LRRK2 protein.
In one aspect the invention provides, a method of treating PD in a subject comprising: (a) measuring the expression levels of a set of genes in a sample from a subject, wherein the set of genes comprises at least one gene selected from the genes listed in Table 2 (b) comparing the expression levels of the set of genes in the subject sample to expression levels of the same set of genes in a reference sample or samples, wherein the reference sample or samples are from an individual who has a PD-associated SNP, and wherein similar expression levels of the set of genes in the subject sample and the set of genes in the reference sample(s) indicates the subject has an increased risk or predisposition to PD, and (c) administering a treatment if the subject has an increased risk or predisposition to PD.
In another aspect, the invention provides a method of treating PD in a subject comprising: (a) determining a level of full-length RAB7L1 in a sample from a subject, (b) comparing the level of full-length RAB7L1 from the subject sample to a full-length RAB7L1 level in a reference sample, wherein the reference sample is associated with a non-PD status, and wherein a reduced level of the full-length RAB7L in the subject sample indicates the subject has an increased risk or predisposition to PD, and (c) administering a treatment if the subject has an increased risk or predisposition to PD. In one embodiment, the level of full-length RAB7L is protein level of full-length RAB7L, or mRNA levels of the full-length RAB7L, or a combination thereof.
In another aspect, the invention provides a method of treating Parkinson's Disease (PD) in a subject comprising: (a) determining a level of isoform 3 of RAB7L1 in a sample from a subject, (b) comparing the level of isoform 3 of RAB7L1 from the subject sample to an isoform 3 of RAB7L1 level in a reference sample, wherein the reference sample is associated in non-PD status, and wherein an increased level of isoform 3 of RAB7L1 in the subject sample indicates the subject has an increased risk or predisposition to PD, and (c) administering a treatment if the subject has an increased risk or predisposition to PD. In one embodiment, the level of isoform 3 of RAB7L1 is a protein level. In one embodiment, the method further comprises determining the level of transcript variant 4, 5, or a combination thereof of RAB7L1.
A method of treating Parkinson's Disease (PD) in a subject comprising: (a) determining a level of transcript variant 4, 5, or a combination thereof of RAB7L1 in a sample from a subject, (b) comparing the level of transcript variant 4, 5, or a combination thereof of RAB7L1 from the subject sample to a transcript variant 4, 5, or a combination thereof of RAB7L1 level in a reference sample, wherein the reference sample is associated in non-PD status, and wherein an increased level of transcript variant 4, 5, or a combination thereof of RAB7L1 in the subject sample indicates the subject has an increased risk or predisposition to PD, and (c) administering a treatment if the subject has an increased risk or predisposition to PD. In one embodiment, the level of transcript variant 4, 5, or a combination thereof of RAB7L1 is a mRNA level. In another embodiment, the method further comprises determining the level of isoform 3 of RAB7L1.
In one embodiment, the invention provides for determine the level of retromer components. Without being bound buy theory, retromer is a complex of proteins which are involved in recycling between the endolysosomal compartment of a cell and the Golgi apparatus. In mammals, proteins of the retromer complex include, but are not limited to Vps26, Vps29, Vps35, SNX1, SNX2, SNX5 and SNX6. The retromer complex can act in two subcomplexes; a cargo recognition complex that comprises Vps35, Vps29 and Vps26 (Vps trimer), and SNX-BAR dimers that comprises SNX1 and SNX2 or SNX5 and SNX6.
In another aspect, the invention provides a method of treating Parkinson's Disease (PD) in a subject comprising: (a) determining a level of retromer components in a sample from a subject, (b) comparing the level of retromer components from the subject sample to a retromer component level in a reference sample, wherein the reference sample is associated with a non-PD status, and wherein a reduced level of the retromer components in the subject sample indicates the subject has an increased risk or predisposition to PD, and (c) administering a treatment if the subject has an increased risk or predisposition to PD. In one embodiment, the level of retromer component is protein level of retromer component, or mRNA levels of retromer component, or a combination thereof. In another embodiment, the retromer component is VPS35, VPS29, VPS26 or a combination thereof. In a further embodiment the retromer component is SNX1, SNX2. SNX5, SNX6, or a combination thereof. In one embodiment, the level of VPS35. VPS29, or VPS26 is protein level of VPS35, VPS29, or VPS26, or mRNA levels of VPS35, VPS29, or VPS26, or a combination thereof.
In one aspect, the invention provides a method of treating PD in a subject. In one embodiment, the treatment comprises administering to the subject an effective amount of a nucleic acid encoding a protein comprising 90% of SEQ ID NO: 6, SEQ ID NO: 26, SEQ ID NO: 11, SEQ ID NO: 14, or a combination or fragment thereof. In another embodiment the treatment comprises administering to the subject an effective amount of a protein comprising 90% of SEQ ID NO: 6, SEQ ID NO: 26. SEQ ID NO: 11, SEQ ID NO: 14, or a combination or fragment thereof. In one embodiment, the protein comprises at least about 70%, at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 91%, at least about 92%, at least about 93%, at least about 94%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, or at least about 99% of SEQ ID NO: 6, SEQ ID NO: 26, SEQ ID NO: 11, or SEQ ID NO: 14.
In one embodiment, the treatment comprises administering to the subject an effective amount of a nucleic acid encoding a protein comprising 90% of SEQ ID NO: 6, SEQ ID NO: 26. SEQ ID NO: 14, or a combination or fragment thereof. In another embodiment, the treatment comprises administering to the subject an effective amount of a protein comprising 90% of SEQ ID NO: 6, SEQ ID NO: 26, SEQ ID NO: 14, or a combination or fragment thereof. In one embodiment, the protein comprises at least about 70%, at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 91%, at least about 92%, at least about 93%, at least about 94%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, or at least about 99% of SEQ ID NO: 6, SEQ ID NO: 26, or SEQ ID NO: 14.
In one embodiment, the treatment comprises administering to the subject an effective amount of a nucleic acid encoding a protein comprising 90% of SEQ ID NO: 11, SEQ ID NO: 14, or a combination or fragment thereof. In another embodiment, the treatment comprises administering to the subject an effective amount of a protein comprising 90% of SEQ ID NO: 11, SEQ ID NO: 14, or a combination or fragment thereof. In one embodiment, the protein comprises at least about 70%, at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 91%, at least about 92%, at least about 93%, at least about 94%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, or at least about 99% of SEQ ID NO: 6, SEQ ID NO: 26, SEQ ID NO: 11, or SEQ ID NO: 14.
In one embodiment, the PD disease status is determined by any suitable method, including but not limited to a physical examination of the subject, a neurological examination of the subject, a brain scan, or a combination thereof. Suitable methods for determining the PD disease statuts are known to one of skill in the art.
In one embodiment, the subject is not diagnosed with PD. In another embodiment, the subject is diagnosed with PD. In another embodiment, the subject is diagnosed with a pre-disease prodromal state.
In one embodiment, the method further comprises a physical examination of the subject, a neurological examination of the subject, a brain scan, or a combination thereof. Methods and types of physical examinations are known to one of skill in the art.
In one embodiment, the method further comprises a step of sequencing nucleic acids isolated from the subject's sample to determine the presence or absence of a PD-risk associated SNP, wherein the presence of a PD-risk associated SNP is further indicative that the subject is at risk of developing PD or is suffering from PD.
In one embodiment, the subject is suspected of having PD or is at risk of developing PD based on the presence of any one of parkinsonism symptoms. Determination of parkinsonism symptoms are known to one of skill in the art.
In one embodiment, the sample is a CSF sample, blood sample, plasma sample, serum sample or any combination thereof. Methods of sample collection are known to one of skill in the art.
Expression Systems and Purification of Recombinant Proteins One skilled in the art understands that polypeptides (for example RAB7L1, LRRK2, or VPS35, and the like) can be obtained in several ways, which include but are not limited to, expressing a nucleotide sequence encoding the protein of interest, or fragment thereof, by genetic engineering methods.
In one embodiment, the nucleic acid is expressed in an expression cassette, for example, to achieve overexpression in a cell. The nucleic acids of the invention can be an RNA, cDNA, cDNA-like, or a DNA of interest in an expressible format, such as an expression cassette, which can be expressed from the natural promoter or an entirely heterologous promoter. The nucleic acid of interest can encode a protein, and may or may not include introns. Any recombinant expression system can be used, including, but not limited to, bacterial, mammalian, yeast, insect, or plant cell expression systems.
Host cells transformed with a nucleic acid sequence encoding a RAB7L1, a LRRK2, or a VPS35 molecule can be cultured under conditions suitable for the expression and recovery of the protein from cell culture. The polypeptide produced by a transformed cell can be secreted or contained intracellularly depending on the sequence and/or the vector used. Expression vectors containing a nucleic acid sequence encoding a RAB7L1, a LRRK2, or a VPS35 molecule can be designed to contain signal sequences which direct secretion of soluble polypeptide molecules encoded by a RAB7L1, a LRRK2, or a VPS35 molecule, through a prokaryotic or eukaryotic cell membrane.
Nucleic acid sequences comprising a RAB7L1, a LRRK2, or a VPS35 molecule that encode a polypeptide can be synthesized, in whole or in part, using chemical methods known in the art. Alternatively, a RAB7L1, a LRRK2, or a VPS35 molecule can be produced using chemical methods to synthesize its amino acid sequence, such as by direct peptide synthesis using solid-phase techniques. Protein synthesis can either be performed using manual techniques or by automation. Automated synthesis can be achieved, for example, using Applied Biosystems 431 A Peptide Synthesizer (Perkin Elmer). Optionally, fragments of a RAB7L1, a LRRK2, or a VPS35 molecule can be separately synthesized and combined using chemical methods to produce a full-length molecule.
A synthetic peptide can be substantially purified via high performance liquid chromatography (HPLC). The composition of a synthetic RAB7L1, LRRK2, or VPS35 molecule can be confirmed by amino acid analysis or sequencing. Additionally, any portion of an amino acid sequence comprising a protein encoded by a RAB7L1, a LRRK2, or a VPS35 molecule can be altered during direct synthesis and/or combined using chemical methods with sequences from other proteins to produce a variant polypeptide or a fusion protein.
The invention further encompasses methods for using a protein or polypeptide encoded by a nucleic acid sequence of a RAB7L1, a LRRK2, or a VPS35 molecule, such as the sequences shown in SEQ ID NOS: 6, 7, 8, 11, 14, 26, 27, or 28. In another embodiment, the polypeptide can be modified, such as by glycosylations and/or acetylations and/or chemical reaction or coupling, and can contain one or several non-natural or synthetic amino acids. An example of a RAB7L1, a LRRK2, or a VPS35 molecule has the amino acid sequence shown in either SEQ ID NO: 6, 7, 8, 11, 14, 26, 27, or 28. In certain embodiments, the invention encompasses variants of a human protein encoded by a RAB7L1, a LRRK2, or a VPS35 molecule.
One skilled in the art understands that expression of desired protein products can be carried out in prokaryotes (e.g. E. coli and B. subtilis), in plant cell systems infected with recombinant virus expression vectors (e.g., tobacco mosaic virus, TMV: cauliflower mosaic virus, CaMV), in insect cells (e.g. Autographa californica nuclear polyhedrosis virus (AcNPV) can be used as a vector to express foreign genes in Spodoptera frugiperda cells or in Trichoplusia larvae), in yeast cells (e.g. Saccharomyces sp., Pichia sp.), or in mammalian cells (e.g. BHK cells, VERO cells, CHO cells and the like).
Expression vectors (also known in the art as fusion-vectors) can be designed to add a number of amino acid residues, usually to the N-terminus of the expressed recombinant protein. Such fusion vectors can serve three functions: 1) to increase the solubility of the desired recombinant protein; 2) to increase expression of the recombinant protein of interest; and 3) to aid in recombinant protein purification by acting as a ligand in affinity purification.
An exogenous nucleic acid can be introduced into a cell via a variety of techniques known in the art, such as lipofection, microinjection, calcium phosphate or calcium chloride precipitation, DEAE-dextrin-mediated transfection, or electroporation. Electroporation is carried out at approximate voltage and capacitance to result in entry of the DNA construct(s) into cells of interest. Other methods used to transfect cells can also include modified calcium phosphate precipitation, polybrene precipitation, liposome fusion, and receptor-mediated gene delivery.
Various culturing parameters can be used with respect to the host cell being cultured. Appropriate culture conditions for mammalian cells are well known in the art (Cleveland W L, et al., J Immunol Methods, 1983, 56(2): 221-234) or can be determined by the skilled artisan (see, for example, Animal Cell Culture: A Practical Approach 2nd Ed., Rickwood, D. and Hames, B. D., eds. (Oxford University Press: New York, 1992)). Cell culturing conditions can vary according to the type of host cell selected. Commercially available medium can be utilized.
A RAB7L1, a LRRK2, or a VPS35 molecule can be purified from any human or non-human cell which expresses the polypeptide, including those which have been transfected with expression constructs that express a RAB7L1, a LRRK2, or a VPS35 molecule. A purified RAB7L1, LRRK2, or VPS35 molecule can be separated from other compounds which normally associate with the RAB7L1, LRRK2, or VPS35 molecules, in the cell, such as certain proteins, carbohydrates, or lipids, using methods practiced in the art. The desired polypeptide molecule (for example, a RAB7L1, a LRRK2, or a VPS35 molecule) is isolated or purified away from contaminating soluble proteins and polypeptides by suitable purification techniques. Non-limiting purification methods for proteins include: size exclusion chromatography; affinity chromatography; ion exchange chromatography; ethanol precipitation; reverse phase HPLC; chromatography on a resin, such as silica, or cation exchange resin, e.g., DEAE; chromatofocusing; SDS-PAGE; ammonium sulfate precipitation; gel filtration using, e.g., Sephadex G-75, Sepharose; protein A sepharose chromatography for removal of immunoglobulin contaminants; and the like. Other additives, such as protease inhibitors (e.g., PMSF or proteinase K) can be used to inhibit proteolytic degradation during purification. Purification procedures that can select for carbohydrates can also be used, e.g., ion-exchange soft gel chromatography, or HPLC using cation- or anion-exchange resins, in which the more acidic fraction(s) is/are collected.
Methods of Administration
Nucleic Acid Delivery Methods.
The invention provides methods for treating Parkinson's Disease (PD) in a subject. In one embodiment, the method can comprise administering to the subject a RAB7L1, a LRRK2, or a VPS35 molecule (e.g, a RAB7L1, a LRRK2, or a VPS35 polypeptide or a RAB7L1, a LRRK2, or a VPS35 polynucleotide).
Various approaches can be carried out to restore the activity or function of a RAB7L1, a LRRK2, or a VPS35 molecule in a subject, such as those carrying an genetic variant in a RAB7L1, a LRRK2, or a VPS35 gene locus. For example, supplying wild-type RAB7L1. LRRK2, or VPS35 gene function to such subjects can treat Parkinson's Disease. Increasing a RAB7L1, a LRRK2, or a VPS35 gene expression level or activity can be accomplished through gene or protein therapy.
A nucleic acid encoding a RAB7L11, a LRRK2, or a VPS35 molecule can be introduced into the cells of a subject. For example, the wild-type gene (or fragment thereof) can also be introduced into the cells of the subject in need thereof using a vector as described herein. The vector can be a viral vector or a plasmid. The gene can also be introduced as naked DNA. The gene can be provided so as to integrate into the genome of the recipient host cells, or to remain extra-chromosomal. Integration can occur randomly or at precisely defined sites, such as through homologous recombination. For example, a functional copy of a RAB7L1, a LRRK2, or a VPS35 molecule can be inserted in replacement of an altered version in a cell, through homologous recombination. Further techniques include gene gun, liposome-mediated transfection, or cationic lipid-mediated transfection. Gene therapy can be accomplished by direct gene injection, or by administering ex vivo prepared genetically modified cells expressing a functional polypeptide.
Delivery of nucleic acids into viable cells can be effected ex vivo, in situ, or in vivo by use of vectors, and more particularly viral vectors (e.g., lentivirus, adenovirus, adeno-associated virus, or a retrovirus), or ex vivo by use of physical DNA transfer methods (e.g., liposomes or chemical treatments). Non-limiting techniques suitable for the transfer of nucleic acid into mammalian cells in vitro include the use of liposomes, electroporation, microinjection, cell fusion, DEAE-dextran, and the calcium phosphate precipitation method (see, for example. Anderson, Nature, supplement to vol. 392, no. 6679, pp. 25-20 (1998)). Introduction of a nucleic acid or a gene encoding a polypeptide of the invention can also be accomplished with extrachromosomal substrates (transient expression) or artificial chromosomes (stable expression). Cells may also be cultured ex vivo in the presence of therapeutic compositions of the present invention in order to proliferate or to produce a desired effect on or activity in such cells. Treated cells can then be introduced in vivo for therapeutic purposes.
Nucleic acids can be inserted into vectors and used as gene therapy vectors. A number of viruses have been used as gene transfer vectors, including papovaviruses, e.g., SV40 (Madzak et al., (1992)J Gen Virol. 73(Pt 6):1533-6), adenovirus (Berkner (1992) Curr Top Microbiol Immunol. 158:39-66; Berkner (1988) Biotechniques, 6(7):616-29; Gorziglia and Kapikian (1992). J Virol. 66(7):4407-12; Quantin et al., (1992) Proc Natl Acad Sci USA. 89(7):2581-4; Rosenfeld et al., (1992) Cell. 68(1):143-55; Wilkinson et al., (1992) Nucleic Acids Res. 20(9):2233-9; Stratford-Perricaudet et al., (1990) Hum Gene Ther. 1(3):241-56), vaccinia virus (Moss (1992) Curr Opin Biotechnol. 3(5):518-22), adeno-associated virus (Muzyczka, (1992) Curr Top Microbiol Immunol. 158:97-129; Ohi et al., (1990) Gene. 89(2):279-82), herpesviruses including HSV and EBV (Margolskee (1992) Curr Top Microbiol Immunol. 158:67-95; Johnson et al., (1992) Brain Res Mol Brain Res.12(1-3):95-102; Fink et al., (1992) Hum Gene Ther. 3(1):11-9; Breakefield and Geller (1987) Mol Neurobiol. 1(4):339-71; Freese et al., (1990) Biochem Pharmacol. 40(10):2189-99), and retroviruses of avian (Bandyopadhyay and Temin (1984) Mol Cell Biol. 4(4):749-54; Petropoulos et al., (1992) J Virol. 66(6):3391-7), murine (Miller et al. (1992) Mol Cell Biol. 12(7):3262-72; Miller et al., (1985) J Virol. 55(3):521-6; Sorge et al., (1984) Mol Cell Biol. 4(9):1730-7; Mann and Baltimore (1985)J Virol. 54(2):401-7; Miller et al., (1988)J Virol. 62(11):4337-45), and human origin (Shimada et al., (1991) J Clin Invest. 88(3):1043-7; Helseth et al., (1990) J Virol. 64(12):6314-8; Page et al., (1990)J Virol. 64(11):5270-6; Buchschacher and Panganiban (1992) J Virol. 66(5):2731-9).
Non-limiting examples of in vivo gene transfer techniques include transfection with viral (typically retroviral) vectors (see U.S. Pat. No. 5,252,479, which is incorporated by reference in its entirety) and viral coat protein-liposome mediated transfection (Dzau et al., Trends in Biotechnology 11:205-210 (1993), incorporated entirely by reference). For example, naked DNA vaccines are generally known in the art; see Brower, Nature Biotechnology, 16:1304-1305 (1998), which is incorporated by reference in its entirety. Gene therapy vectors can be delivered to a subject by, for example, intravenous injection, local administration (see, e.g., U.S. Pat. No. 5,328,470) or by stereotactic injection (see, e.g., Chen, et al., 1994. Proc. Natl. Acad. Sci. USA 91: 3054-3057). The pharmaceutical preparation of the gene therapy vector can include the gene therapy vector in an acceptable diluent, or can comprise a slow release matrix in which the gene delivery vehicle is imbedded. Alternatively, where the complete gene delivery vector can be produced intact from recombinant cells, e.g., retroviral vectors, the pharmaceutical preparation can include one or more cells that produce the gene delivery system.
For reviews of gene therapy protocols and methods see Anderson et al., Science 256:808-813 (1992); U.S. Pat. Nos. 5,252,479, 5,747,469, 6,017,524, 6,143,290, 6,410,010 6,511,847; 8,398,968; and 8,404,653 which are all hereby incorporated by reference in their entireties. For an example of gene therapy treatment in humans see Porter et al., NEJM 2011 365:725-733 and Kalos et al. Sci. Transl. Med. 2011. 201 3(95):95. For additional reviews of gene therapy technology, see Friedmann, Science, 244:1275-1281 (1989); Verma, Scientific American: 68-84 (1990); Miller, Nature, 357: 455-460 (1992); Kikuchi et al., J Dermatol Sci. 2008 May; 50(2):87-98; Isaka et al., Expert Opin Drug Deliv. 2007 September; 4(5):561-71; Jager et al., Curr Gene Ther. 2007 August; 7(4):272-83; Waehler et al., Nat Rev Genet. 2007 August; 8(8):573-87; Jensen et al., Ann Med. 2007; 39(2):108-15; Herweijer et al., Gene Ther. 2007 January; 14(2):99-107; Eliyahu et al., Molecules, 2005 Jan. 31; 10(1):34-64; and Altaras et al., Adv Biochem Eng Biotechnol. 2005; 99:193-260, all of which are hereby incorporated by reference in their entireties.
These methods described herein are by no means all-inclusive, and further methods to suit the specific application is understood by the ordinary skilled artisan. Moreover, the effective amount of the compositions can be further approximated through analogy to compounds known to exert the desired effect.
Protein Delivery Methods.
Protein replacement therapy can increase the amount of protein by exogenously introducing wild-type or biologically functional protein by way of infusion. A replacement polypeptide can be synthesized according to known chemical techniques or may be produced and purified via known molecular biological techniques. Protein replacement therapy has been developed for various disorders. For example, a wild-type protein can be purified from a recombinant cellular expression system (e.g., mammalian cells or insect cells-see U.S. Pat. No. 5,580,757 to Desnick et al.; U.S. Pat. Nos. 6,395,884 and 6,458,574 to Selden et al.; U.S. Pat. No. 6,461,609 to Calhoun et al.; U.S. Pat. No. 6,210,666 to Miyamura et al.; U.S. Pat. No. 6,083,725 to Selden et al.; U.S. Pat. No. 6,451,600 to Rasmussen et al.; U.S. Pat. No. 5,236,838 to Rasmussen et al. and U.S. Pat. No. 5,879,680 to Ginns et al.), human placenta, or animal milk (see U.S. Pat. No. 6,188,045 to Reuser et al.), or other sources known in the art. After the infusion, the exogenous protein can be taken up by tissues through non-specific or receptor-mediated mechanism.
A RAB7L1, a LRRK2, or a VPS35 molecule can also be delivered in a controlled release system. For example, the RAB7L1, LRRK2, or VPS35 molecule can be administered using intravenous infusion, an implantable osmotic pump, a transdermal patch, liposomes, or other modes of administration. In one embodiment, a pump can be used (see Sefton (1987) Biomed. Eng. 14:201; Buchwald et al. (1980) Surgery 88:507; Saudek et al. (1989) N. Engl. J. Med. 321:574). In another embodiment, polymeric materials can be used (see Medical Applications of Controlled Release, Langer and Wise (eds.), CRC Pres., Boca Raton, Fla. (1974); Controlled Drug Bioavailability, Drug Product Design and Performance, Smolen and Ball (eds.), Wiley, New York (1984); Ranger and Peppas, (1983) J. Macromol. Sci. Rev. Macromol. Chem. 23:61; see also Levy et al. (1985) Science 228:190; During et al. (1989) Ann. Neurol. 25:351; Howard et al. (1989) J. Neurosurg. 71:105). In yet another embodiment, a controlled release system can be placed in proximity of the therapeutic target thus requiring only a fraction of the systemic dose (see, e.g., Goodson, in Medical Applications of Controlled Release, supra, vol. 2, pp. 115-138 (1984)). Other controlled release systems are discussed in the review by Langer (Science (1990) 249:1527-1533).
Pharmaceutical Compositions and Methods of Administration
In some embodiments, a RAB7L1, a LRRK2, or a VPS35 molecule can be supplied in the form of a pharmaceutical composition, comprising an isotonic excipient prepared under sufficiently sterile conditions for human administration. Choice of the excipient and any accompanying elements of the composition comprising a RAB7L1, a LRRK2, or a VPS35 molecule will be adapted in accordance with the route and device used for administration. In some embodiments, a composition comprising a RAB7L1, a LRRK2, or a VPS35 molecule can also comprise, or be accompanied with, one or more other ingredients that facilitate the delivery or functional mobilization of the RAB7L1, LRRK2, or VPS35 molecule.
These methods described herein are by no means all-inclusive, and further methods to suit the specific application is understood by the ordinary skilled artisan. Moreover, the effective amount of the compositions can be further approximated through analogy to compounds known to exert the desired effect.
According to the invention, a pharmaceutically acceptable carrier can comprise any and all solvents, dispersion media, coatings, antibacterial and antifungal agents, isotonic and absorption delaying agents, and the like, compatible with pharmaceutical administration. The use of such media and agents for pharmaceutically active substances is well known in the art. Any conventional media or agent that is compatible with the active compound can be used. Supplementary active compounds can also be incorporated into the compositions.
A RAB7L1, a LRRK2, or a VPS35 molecule can be administered to the subject one time (e.g., as a single injection or deposition). Alternatively, a RAB7L1, a LRRK2, or a VPS35 molecule can be administered once or twice daily to a subject in need thereof for a period of from about 2 to about 28 days, or from about 7 to about 10 days, or from about 7 to about 15 days. It can also be administered once or twice daily to a subject for a period of 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12 times per year, or a combination thereof. Furthermore, a RAB7L1, a LRRK2, or a VPS35 molecule can be co-administrated with another therapeutic.
In one embodiment, a RAB7L1, a LRRK2, or a VPS35 molecule can be co-administrated with a Parkinson's Disease drug. Some non-limiting examples of conventional PD drugs include: levodopa, carbidopa/levodopa (co-careldopa), benserazide/levodopadopamine (co-beneldopa), dopamine agonists (e.g., bromocriptine, pergolide, pramipexole, ropinirole, piribedil, cabergoline, apomorphine, and lisuride), MAO-B inhibitors (e.g. selegiline, and rasagiline), amantadine, and anticholingerics.
A RAB7L1, a LRRK2, or a VPS35 molecule may also be used in combination with surgical or other interventional treatment regimens used for the treatment of PD.
A RAB7L1, a LRRK2, or a VPS35 molecule can be administered to a subject by any means suitable for delivering the protein, nucleic acid or compound to cells of the subject. For example, it can be administered by methods suitable to transfect cells. Transfection methods for eukaryotic cells are well known in the art, and include direct injection of the nucleic acid into the nucleus or pronucleus of a cell; electroporation; liposome transfer or transfer mediated by lipophilic materials; receptor mediated nucleic acid delivery, bioballistic or particle acceleration; calcium phosphate precipitation, and transfection mediated by viral vectors.
The compositions of this invention can be formulated and administered to reduce the symptoms associated with PD by any means that produce contact of the active ingredient with the agent's site of action in the body of a human or non-human subject. They can be administered by any conventional means available for use in conjunction with pharmaceuticals, either as individual therapeutic active ingredients or in a combination of therapeutic active ingredients. They can be administered alone, but are generally administered with a pharmaceutical carrier selected on the basis of the chosen route of administration and standard pharmaceutical practice.
Pharmaceutical compositions for use in accordance with the invention can be formulated in conventional manner using one or more physiologically acceptable carriers or excipients. The therapeutic compositions of the invention can be formulated for a variety of routes of administration, including systemic and topical or localized administration. Techniques and formulations generally can be found in Remmington's Pharmaceutical Sciences, Meade Publishing Co., Easton, Pa. (20th ed., 2000), the entire disclosure of which is herein incorporated by reference. For systemic administration, an injection is useful, including intramuscular, intravenous, intraperitoneal, and subcutaneous. For injection, the therapeutic compositions of the invention can be formulated in liquid solutions, for example in physiologically compatible buffers, such as PBS, Hank's solution, or Ringer's solution. In addition, the therapeutic compositions can be formulated in solid form and redissolved or suspended immediately prior to use. Lyophilized forms are also included. Pharmaceutical compositions of the present invention are characterized as being at least sterile and pyrogen-free. These pharmaceutical formulations include formulations for human and veterinary use.
Any of the therapeutic applications described herein can be applied to any subject in need of such therapy, including, for example, a mammal such as a dog, a cat, a cow, a horse, a rabbit, a monkey, a pig, a sheep, a goat, or a human.
A pharmaceutical composition of the invention is formulated to be compatible with its intended route of administration. Examples of routes of administration include parenteral, e.g., intravenous, intradermal, subcutaneous, oral (e.g., inhalation), transdermal (topical), transmucosal, and rectal administration. Solutions or suspensions used for parenteral, intradermal, or subcutaneous application can include the following components: a sterile diluent such as water for injection, saline solution, fixed oils, polyethylene glycols, glycerine, propylene glycol or other synthetic solvents; antibacterial agents such as benzyl alcohol or methyl parabens; antioxidants such as ascorbic acid or sodium bisulfite; chelating agents such as ethylenediaminetetraacetic acid; buffers such as acetates, citrates or phosphates and agents for the adjustment of tonicity such as sodium chloride or dextrose. pH can be adjusted with acids or bases, such as hydrochloric acid or sodium hydroxide. The parenteral preparation can be enclosed in ampoules, disposable syringes or multiple dose vials made of glass or plastic.
Pharmaceutical compositions suitable for injectable use include sterile aqueous solutions (where water soluble) or dispersions and sterile powders for the extemporaneous preparation of sterile injectable solutions or dispersions. For intravenous administration, suitable carriers include physiological saline, bacteriostatic water, Cremophor EM™(BASF, Parsippany. N.J.) or phosphate buffered saline (PBS). The composition must be sterile and fluid to the extent that easy syringability exists. It must be stable under the conditions of manufacture and storage and must be preserved against the contaminating action of microorganisms such as bacteria and fungi. The carrier can be a solvent or dispersion medium containing, for example, water, ethanol, a pharmaceutically acceptable polyol like glycerol, propylene glycol, liquid polyetheylene glycol, and suitable mixtures thereof. The proper fluidity can be maintained, for example, by the use of a coating such as lecithin, by the maintenance of the required particle size in the case of dispersion and by the use of surfactants. Prevention of the action of microorganisms can be achieved by various antibacterial and antifungal agents, for example, parabens, chlorobutanol, phenol, ascorbic acid, and thimerosal. In many cases, it can be useful to include isotonic agents, for example, sugars, polyalcohols such as mannitol, sorbitol, sodium chloride in the composition. Prolonged absorption of the injectable compositions can be brought about by including in the composition an agent which delays absorption, for example, aluminum monostearate and gelatin.
Sterile injectable solutions can be prepared by incorporating the RAB7L1, LRRK2, or VPS35 molecule in the required amount in an appropriate solvent with one or a combination of ingredients enumerated herein, as required, followed by filtered sterilization. Dispersions are prepared by incorporating the active compound into a sterile vehicle which contains a basic dispersion medium and the required other ingredients from those enumerated herein. In the case of sterile powders for the preparation of sterile injectable solutions, examples of useful preparation methods are vacuum drying and freeze-drying which yields a powder of the active ingredient plus any additional desired ingredient from a previously sterile-filtered solution thereof.
Oral compositions include an inert diluent or an edible carrier. They can be enclosed in gelatin capsules or compressed into tablets. For the purpose of oral therapeutic administration, the active compound can be incorporated with excipients and used in the form of tablets, troches, or capsules. Oral compositions can also be prepared using a fluid carrier for use as a mouthwash, wherein the compound in the fluid carrier is applied orally and swished and expectorated or swallowed.
Pharmaceutically compatible binding agents, and/or adjuvant materials can be included as part of the composition. The tablets, pills, capsules, troches and the like can contain any of the following ingredients, or compounds of a similar nature: a binder such as microcrystalline cellulose, gum tragacanth or gelatin; an excipient such as starch or lactose, a disintegrating agent such as alginic acid, Primogel, or corn starch; a lubricant such as magnesium stearate or sterotes; a glidant such as colloidal silicon dioxide; a sweetening agent such as sucrose or saccharin; or a flavoring agent such as peppermint, methyl salicylate, or orange flavoring.
Systemic administration can also be by transmucosal or transdermal means. For transmucosal or transdermal administration, penetrants appropriate to the barrier to be permeated are used in the formulation. Such penetrants are known in the art, and include, for example, for transmucosal administration, detergents, bile salts, and fusidic acid derivatives. Transmucosal administration can be accomplished through the use of nasal sprays or suppositories. For transdermal administration, the active compounds are formulated into ointments, salves, gels, or creams as known in the art
A composition of the invention can be administered to a subject in need thereof. Subjects in need thereof can include but are not limited to, for example, a mammal such as a dog, a cat, a cow, a horse, a rabbit, a monkey, a pig, a sheep, a goat, or a human. A composition of the invention can also be formulated as a sustained and/or timed release formulation. Such sustained and/or timed release formulations can be made by sustained release means or delivery devices that are well known to those of ordinary skill in the art, such as those described in U.S. Pat. Nos. 3,845,770; 3,916,899; 3,536,809; 3,598,123; 4,008,719; 4,710,384; 5,674,533; 5,059,595; 5,591,767; 5,120,548; 5.073.543; 5,639,476; 5,354,556; and 5,733,566, the disclosures of which are each incorporated herein by reference. The pharmaceutical compositions of the invention (e.g., that have a therapeutic effect) can be used to provide slow or sustained release of one or more of the active ingredients using, for example, hydropropylmethyl cellulose, other polymer matrices, gels, permeable membranes, osmotic systems, multilayer coatings, microparticles, liposomes, microspheres, or the like, or a combination thereof to provide the desired release profile in varying proportions. Suitable sustained release formulations known to those of ordinary skill in the art, including those described herein, can be readily selected for use with the pharmaceutical compositions of the invention. Single unit dosage forms suitable for oral administration, such as, but not limited to, tablets, capsules, gel-caps, caplets, or powders, that are adapted for sustained release are encompassed by the invention.
In the methods described herein, a RAB7L1, a LRRK2, or a VPS35 molecule, can be administered to the subject either as RNA, in conjunction with a delivery reagent, or as a nucleic acid (e.g., a recombinant plasmid or viral vector) comprising sequences which express the gene product. Suitable delivery reagents for administration of the a RAB7L1, a LRRK2, or a VPS35 molecule, include the Mirus Transit TKO lipophilic reagent; lipofectin; lipofectamine; cellfectin; or polycations (e.g., polylysine), or liposomes.
The dosage administered can be a therapeutically effective amount of the composition sufficient to result in treatment of PD, and can vary depending upon known factors such as the pharmacodynamic characteristics of the active ingredient and its mode and route of administration; time of administration of active ingredient; age, sex, health and weight of the recipient; nature and extent of symptoms; kind of concurrent treatment, frequency of treatment and the effect desired; and rate of excretion.
In some embodiments, the effective amount of the administered RAB7L1, LRRK2, or VPS35 molecule is at least about 0.01 μg/kg body weight, at least about 0.025 μg/kg body weight, at least about 0.05 μg/kg body weight, at least about 0.075 μg/kg body weight, at least about 0.1 μg/kg body weight, at least about 0.25 μg/kg body weight, at least about 0.5 μg/kg body weight, at least about 0.75 μg/kg body weight, at least about 1 μg/kg body weight, at least about 5 μg/kg body weight, at least about 10 μg/kg body weight, at least about 25 μg/kg body weight, at least about 50 μg/kg body weight, at least about 75 μg/kg body weight, at least about 100 μg/kg body weight, at least about 150 μg/kg body weight, at least about 200 μg/kg body weight, at least about 250 μg/kg body weight, at least about 300 μg/kg body weight, at least about 350 μg/kg body weight, at least about 400 μg/kg body weight, at least about 450 μg/kg body weight, at least about 500 μg/kg body weight, at least about 550 μg/kg body weight, at least about 600 μg/kg body weight, at least about 650 μg/kg body weight, at least about 700 μg/kg body weight, at least about 750 μg/kg body weight, at least about 800 μg/kg body weight, at least about 850 μg/kg body weight, at least about 900 μg/kg body weight, at least about 950 μg/kg body weight, at least about 1000 μg/kg body weight, at least about 1500 μg/kg body weight, at least about 2000 μg/kg body weight, at least about 2500 μg/kg body weight, at least about 3000 μg/kg body weight, at least about 3500 μg/kg body weight, at least about 4000 μg/kg body weight, at least about 4500 μg/kg body weight, at least about 5000 μg/kg body weight, at least about 5500 μg/kg body weight, at least about 6000 μg/kg body weight, at least about 6500 μg/kg body weight, at least about 7000 μg/kg body weight, at least about 7500 μg/kg body weight, at least about 8000 μg/kg body weight, at least about 8500 μg/kg body weight, at least about 9000 μg/kg body weight, at least about 9500 μg/kg body weight, or at least about 10000 μg/kg body weight.
In one embodiment, a RAB7L1, a LRRK2, or a VPS35 molecule is administered at least once daily. In another embodiment, a RAB7L1, a LRRK2, or a VPS35 molecule is administered at least twice daily. In some embodiments, a RAB7L1, a LRRK2, or a VPS35 molecule is administered for at least 1 week, for at least 2 weeks, for at least 3 weeks, for at least 4 weeks, for at least 5 weeks, for at least 6 weeks, for at least 8 weeks, for at least 10 weeks, for at least 12 weeks, for at least 18 weeks, for at least 24 weeks, for at least 36 weeks, for at least 48 weeks, or for at least 60 weeks. In further embodiments, a RAB7L1, a LRRK2, or a VPS35 molecule is administered in combination with a second therapeutic agent.
Toxicity and therapeutic efficacy of therapeutic compositions of the present invention can be determined by standard pharmaceutical procedures in cell cultures or experimental animals, e.g., for determining the LD50 (the dose lethal to 50% of the population) and the ED50 (the dose therapeutically effective in 50% of the population). The dose ratio between toxic and therapeutic effects is the therapeutic index and it can be expressed as the ratio LD50/ED50. Therapeutic agents that exhibit large therapeutic indices are useful. Therapeutic compositions that exhibit some toxic side effects can be used.
Administration of a RAB7L1, a LRRK2, or a VPS35 molecule is not restricted to a single route, but may encompass administration by multiple routes. Multiple administrations may be sequential or concurrent. Other modes of application by multiple routes will be apparent to one of skill in the art.
Methods of Detection
Embodiments of the invention provide for detecting expression of a RAB7L1, a LRRK2, or a VPS35 molecule. In one embodiment, a gene alteration can result in increased or reduced protein expression and/or activity. The alteration can be determined at the level of the DNA, RNA, or polypeptide.
In some embodiments, the detecting comprises detecting in a biological sample whether there is a reduction in an mRNA encoding a RAB7L1, a LRRK2, or a VPS35 protein, or a reduction in a RAB7L1, a LRRK2, or a VPS35 protein, or a combination thereof. In further embodiments, the detecting comprises detecting in a biological sample whether there is a reduction in an mRNA encoding a RAB7L1, a LRRK2, or a VPS35 protein, or a reduction in a RAB7L1, a LRRK2, or a VPS35 protein, or a combination thereof. The presence of such an alteration is indicative of the presence or predisposition to PD.
Methods for detecting and quantifying RAB7L1, LRRK2, or VPS35 molecules in biological samples are known the art. For example, protocols for detecting and measuring the expression of a polypeptide encoded by a RAB7L1, a LRRK2, or a VPS35 molecule, using either polyclonal or monoclonal antibodies specific for the polypeptide are well established. Non-limiting examples include Western blot, enzyme-linked immunosorbent assay (ELISA), radioimmunoassay (RIA), and fluorescence activated cell sorting (FACS).
In one embodiment, a biological sample comprises, a blood sample, serum, cells (including whole cells, cell fractions, cell extracts, and cultured cells or cell lines), tissues (including tissues obtained by biopsy), body fluids (e.g., urine, sputum, amniotic fluid, synovial fluid), or from media (from cultured cells or cell lines). In one embodiment, the sample is a CSF sample, a blood sample, a plasma sample, a serum sample, or any combination thereof. The methods of detecting or quantifying RAB7L1, LRRK2, or VPS35 molecules include, but are not limited to, amplification-based assays with (signal amplification) hybridization based assays and combination amplification-hybridization assays.
Any suitable biological sample can be used in the instant methods. The biological sample can be taken from body fluid, such as urine, saliva, bone marrow, blood, and derivative blood products (sera, plasma, PBMC, circulating cells, circulating RNA). The biological sample can be taken from a human subject, from an animal, or from a cell culture. The biological sample can be obtained in vivo, in vitro or ex vivo. Non-limiting examples of biological samples include blood, serum, plasma, cerebrospinal fluid, mucus, tissue, cells, and the like, or any combination thereof. In a non-limiting embodiment the biological sample is blood. In a non-limiting embodiment the biological sample is serum. In a non-limiting embodiment the biological sample is plasma. Any suitable method to isolate nucleic acids from biological samples are contemplated for use in the invention. Biological samples for analysis are stored under suitable conditions. In non-limiting examples biological samples are kept at about 4° C. In non-limiting examples biological samples are kept at about −20° C. In non-limiting examples biological samples are kept at about −70-80° C.
A RAB7L1, a LRRK2, or a VPS35 molecule can be determined at the nucleic acid level. Optionally, detection can be determined by performing an oligonucleotide ligation assay, a confirmation based assay, a hybridization assay, a sequencing assay, an allele-specific amplification assay, a microsequencing assay, a melting curve analysis, a denaturing high performance liquid chromatography (DHPLC) assay (for example, see Jones et al, (2000) Hum Genet., 106(6):663-8), or a combination thereof. In one embodiment, the detection or determination comprises nucleic acid sequencing, selective hybridization, selective amplification, gene expression analysis, or a combination thereof. In one embodiment, the detection is performed by sequencing all or part of a RAB7L1, a LRRK2, or a VPS35 molecule, or by selective hybridization or amplification of all or part of the RAB7L1 LRRK2, or VPS35 molecule. A nucleic acid specific amplification can be carried out before the quantification step. In one embodiment, the detecting comprises using a northern blot; real time PCR and primers directed to SEQ ID NO: 1, 2, 3, 4, 5, 9, 10, 12, or 13; a ribonuclease protection assay; a hybridization, amplification, or sequencing technique to detect a RAB7L1, a LRRK2, or a VPS35 molecule; or a combination thereof. In another embodiment, the PCR primers comprise at least 10, at least 11, at least 12, at least 13, at least 14, at least 15, at least 16, at least 17, at least 18, at least 19, at least 20 consecutive nucleotides comprising SEQ ID NO: 1, 2, 3, 4, 5, 9, 10, 12, 13, 15, 16, 17, 18, 19, 24, 25, or a combination of the primers.
Hybridization detection methods are based on the formation of specific hybrids between complementary nucleic acid. A detection technique involves the use of a nucleic acid probe specific for the presence of a RAB7L1, a LRRK2, or a VPS35 molecule, followed by the detection of the presence of a hybrid. The probe can be in suspension or immobilized on a substrate or support (for example, as in nucleic acid array or chips technologies). The probe can be labeled to facilitate detection of hybrids. In one embodiment, the probe according to the invention can comprise a nucleic acid directed to SEQ ID NO: 1, 2, 3, 4, 5, 9, 10, 12, or 13. In another embodiment, the probe that detects the presence of a RAB7L1, a LRRK2, or a VPS35 molecule comprises SEQ ID NO: 15, 16, 17, 18, 19, 24, or 25.
A guide to the hybridization of nucleic acids is found in e.g., Sambrook, ed., Molecular Cloning: A Laboratory Manual (3rd Ed.), Vols. 1-3, Cold Spring Harbor Laboratory, 1989; Current Protocols In Molecular Biology, Ausubel, ed. John Wiley & Sons, Inc., New York, 2001; Laboratory Techniques In Biochemistry And Molecular Biology: Hybridization With Nucleic Acid Probes, Part I. Theory and Nucleic Acid Preparation, Tijssen, ed. Elsevier, N. Y., 1993.
Sequencing can be carried out using techniques well known in the art, using automatic sequencers. The sequencing can be performed on a RAB7L1, a LRRK2, or a VPS35 molecule. In another embodiment, the sequencing can be performed using SEQ ID NO: 24, or 25.
Amplification is based on the formation of specific hybrids between complementary nucleic acid sequences that serve to initiate nucleic acid reproduction. Amplification can be performed according to various techniques known in the art, such as by polymerase chain reaction (PCR), ligase chain reaction (LCR), strand displacement amplification (SDA) and nucleic acid sequence based amplification (NASBA). These techniques can be performed using commercially available reagents and protocols. Useful techniques in the art encompass real-time PCR, allele-specific PCR, or PCR based single-strand conformational polymorphism (SSCP). Amplification usually requires the use of specific nucleic acid primers, to initiate the reaction. In one embodiment, amplification comprises using forward and reverse PCR primers directed to SEQ ID NO: 1, 2, 3, 4, 5, 9, 10, 12, or 13. In certain subjects, the downregulation of a RAB7L1, a LRRK2, or a VPS35 molecule corresponds to a subject with PD. In one embodiment, amplification can comprise using forward and reverse PCR primers comprising at least 10, at least 11, at least 12, at least 13, at least 14, at least 15, at least 16, at least 17, at least 18, at least 19, at least 20 consecutive nucleotides comprising SEQ ID NO: 15, 16, 17, 18, 19, 24, or 25.
Non-limiting amplification methods include, e.g., polymerase chain reaction. PCR (PCR Protocols. A Guide To Methods And Applications, ed. Innis, Academic Press, N. Y., 1990 and PCR Strategies, 1995, ed. Innis, Academic Press. Inc., N.Y.); ligase chain reaction (LCR) (Wu (1989) Genomics 4:560; Landegren (1988) Science 241:1077; Barringer (1990) Gene 89:117); transcription amplification (Kwoh (1989) PNAS 86:1173); and, self-sustained sequence replication (Guatelli (1990) PNAS 87:1874); Q Beta replicase amplification (Smith (1997) J. Clin. Microbiol. 35:1477-1491), automated Q-beta replicase amplification assay (Burg (1996) Mol. Cell. Probes 10:257-271) and other RNA polymerase mediated techniques (e.g., NASBA, Cangene, Mississauga, Ontario; see also Berger (1987) Methods Enzymol. 152:307-316; U.S. Pat. Nos. 4,683,195 and 4,683,202; and Sooknanan (1995) Biotechnology 13:563-564). All the references stated above are incorporated by reference in their entireties.
The invention provides for a nucleic acid primer, wherein the primer can be complementary to and hybridize specifically to a portion of a RAB7L1, a LRRK2, or a VPS35 molecule. Primers can be specific for a RAB7L1, a LRRK2, or a VPS35 molecule. By using such primers, the detection of an amplification product indicates the presence of a a RAB7L1, a LRRK2, or a VPS35 molecule. Examples of primers of this invention can be single-stranded nucleic acid molecules of about 8 to about 15 nucleotides in length. Perfect complementarity is useful to ensure high specificity; however, certain mismatch can be tolerated. For example, a nucleic acid primer or a pair of nucleic acid primers as described above can be used in a method for detecting the presence of a genetic variant in a subject. In one embodiment, primers can be used to detect the absence of reduced level of a RAB7L1, a LRRK2, or a VPS35 molecule. In some embodiments, the primers are directed to SEQ ID NO: 1, 2, 3, 4, 5, 9, 10, 12, or 13. In another embodiment, the PCR primers comprise at least 10, at least 11, at least 12, at least 13, at least 14, at least 15, at least 16, at least 17, at least 18, at least 19, at least 20 consecutive nucleotides comprising SEQ ID NO: 15, 16, 17, 18, 19, 24, or 25.
Compositions and Kits of the Invention
In one aspect, the invention provides a composition for evaluating the existence of, or predisposition to, PD in a subject, said composition comprising polynucleotides or oligonucleotides, wherein each polynucleotide or oligonucleotide hybridizes to a gene, gene fragment, or gene transcript of at least two different markers in a subject sample, wherein the markers comprise LRRK2, RAB7L1 and VPS35.
In another aspect, the invention provides a composition for evaluating the existence of, or predisposition to, PD in a subject, said composition comprising polynucleotides or oligonucleotides, wherein each polynucleotide or oligonucleotide hybridizes to a gene, gene fragment, or gene transcript of a different marker in a subject sample, each marker being one of the genes listed in Table 2.
In one embodiment, the composition comprises a microarray, a microfluidics card, a chip, or a chamber. In another aspect, the invention provides a diagnostic kit comprising the microarray, microfluidics card, chip, or chamber.
In another aspect, the invention provides a diagnostic kit for determining the levels of RAB7L1, LRRK2, VPS35, or a combination thereof, the kit comprising at least one oligonucleotide or polynucleotide to selectively quantify the levels of RAB7L1, LRRK2, VPS35, or a combination thereof. In one embodiment, the oligonucleotide or polynucleotide comprises SEQ ID NO: 15, 16, 17, or 18. In another embodiment, the oligonucleotide or polynucleotide comprises at least about 70%, at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 91%, at least about 92%, at least about 93%, at least about 94%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, or at least about 99% of SEQ ID NO: 15, 16, 17, or 18.
In another aspect, the invention provides for a diagnostic kit for determining whether a sample from a subject exhibits a presence or absence of a PD-associated genetic variant, the kit comprising at least one oligonucleotide or polynucleotide for sequencing nucleic acids isolated from the subject's sample to determine the presence or absence of a PD-risk associated SNP, wherein the presence of a PD-risk associated SNP is further indicative that the subject is at risk of developing PD or is suffering from PD. In one embodiment, the oligonucleotide or polynucleotide comprises SEQ ID NO: 24, or 25. In another embodiment, the oligonucleotide or polynucleotide comprises at least about 70%, at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 91%, at least about 92%, at least about 93%, at least about 94%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, or at least about 99% of SEQ ID NO: 24, or 25.
The kits of the invention may also include reagents necessary or useful for the amplification of target nucleic acids, which may include, but is not limited to, DNA polymerase enzymes, primer extension deoxynucleotide triphosphates, and any buffer or other solutions generally used in PCR amplification reactions and kits.
In one embodiment, the kit can further comprise reagents and/or protocols for performing a hybridization, or amplification. In one embodiment, the kit can comprise nucleic acid primers that specifically hybridize to and can prime a polymerase reaction from a RAB7L1, a LRRK2, or a VPS35 molecule comprising at least 10, at least 11, at least 12, at least 13, at least 14, at least 15, at least 16, at least 17, at least 18, at least 19, at least 20 consecutive nucleotides comprising SEQ ID NOS: 15, 16, 17, 18, 19, 24, or 25, or a combination of the primers. In one embodiment, primers can be used to detect the absence or reduction of a RAB7L1, a LRRK2, or a VPS35 molecule, such as a primer directed to SEQ ID NOS: 1, 2, 3, 4, 5, 9, 10, 12, or 13. In another embodiment, the PCR primer comprises at least 10, at least 11, at least 12, at least 13, at least 14, at least 15, at least 16, at least 17, at least 18, at least 19, at least 20 consecutive nucleotides comprising SEQ ID NOS: 15, 16, 17, 18, 19, 24, or 25. In some embodiments, the kit comprises a probe for detecting a RAB7L1, a LRRK2, or a VPS35 molecule.
The diagnosis methods can be performed in vitro, ex vivo, or in vivo. These methods utilize a sample from the subject in order to assess the status of a RAB7L1, a LRRK2, or a VPS35 molecule. The sample can be any biological sample derived from a subject, which contains nucleic acids or polypeptides. Examples of such samples include, but are not limited to, fluids, tissues, cell samples, organs, and tissue biopsies. Non-limiting examples of samples include blood, liver, plasma, serum, saliva, urine, or seminal fluid. The sample can be collected according to conventional techniques and used directly for diagnosis or stored. The sample can be treated prior to performing the method, in order to render or improve availability of nucleic acids or polypeptides for testing. Treatments include, for instance, lysis (e.g., mechanical, physical, or chemical), centrifugation. The nucleic acids and/or polypeptides can be pre-purified or enriched by conventional techniques, and/or reduced in complexity. Nucleic acids and polypeptides can also be treated with enzymes or other chemical or physical treatments to produce fragments thereof. In one embodiment, the sample is contacted with reagents, such as probes or primers, in order to assess the absence or presence of a RAB7L1, a LRRK2, or a VPS35 molecule. Contacting can be performed in any suitable device, such as a plate, tube, well, or glass. In some embodiments, the contacting is performed on a substrate coated with the reagent, such as a nucleic acid array or a specific ligand array. The substrate can be a solid or semi-solid substrate such as any support comprising glass, plastic, nylon, paper, metal, or polymers. The substrate can be of various forms and sizes, such as a slide, a membrane, a bead, a column, or a gel. The contacting can be made under any condition suitable for a complex to be formed between the reagent and the nucleic acids or polypeptides of the sample.
These methods described herein are by no means all-inclusive, and further methods to suit the specific application will be apparent to the ordinary skilled artisan. Moreover, the effective amount of the compositions can be further approximated through analogy to compounds known to exert the desired effect.
Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Exemplary methods and materials are described below, although methods and materials similar or equivalent to those described herein can also be used in the practice or testing of the present invention.
All publications and other references mentioned herein are incorporated by reference in their entirety, as if each individual publication or reference were specifically and individually indicated to be incorporated by reference. Publications and references cited herein are not admitted to be prior art.
A number of Examples are provided below to facilitate a more complete understanding of the present invention. The following examples illustrate the exemplary modes of making and practicing the present invention. However, the scope of the invention is not limited to specific embodiments disclosed in these Examples, which are for purposes of illustration only, since alternative methods can be utilized to obtain similar results.
An unbiased and systematic approach was sought to assess the phenotypic impacts of common genetic variants associated with PD risk, particularly in brain tissue from yet unaffected carriers (
The transcriptome-wide GPI at 7 PD-associated loci was assessed (SNCA, LRRK2, MAPT, HLA-DRA, PARK16, LAMP3, STK39, Table 1) (Simon-Sanchez et al., 2009) in a publically available gene expression dataset from cerebral cortex autopsy brain tissue of 185 individuals not apparently affected by a neurodegenerative disease (GSE15222).
The GPIs of the 7 loci revealed a high degree of overlap in terms of the identity of transcripts altered in expression level and the valence of such alterations: genes were coordinately altered in their expression by each of the 7 PD-associated loci (over 15-fold greater than expected by chance: p=1.5E-5 by resampling statistics;
This observation of an overlapping GPI for these 7 PD-associated loci was moreover confirmed in an additional independent dataset of cerebral frontal cortex autopsy brain tissue of 143 individuals (p=1.6 E-3 by resampling statistics: derived from GEO GSE15745).
Function annotation was performed on the gene expression changes that underlie the common GPIs among PD risk variants. Strikingly, among the annotated gene sets most significantly reduced in expression are “mitochondria” functions (
LRRK2 and PARK16 Variants Cooperatively Determine PD Risk
Among the 7 analyzed PD risk locus GPIs, those at the PARK16 and LRRK2 loci were found to be the most similar. Furthermore, variants at these two loci impacted the transcriptome in a non-additive manner, signifying a genetic interaction (as determined by analysis of carriers of both risk variants;
Taken together, these data strongly support a genetic interaction between LRRK2 and PARK16 that initially impacts human CNS tissue physiology, as reflected by the transcriptome signature in unaffected carriers, and ultimately favors PD pathology in a small subset of individuals at risk.
Evidence of a LRRK2-RAB7L) Pathway
As 5 candidate genes are present within the PARK16 locus (SLC45A3, NUCKS, RAB7L1, SLC41A1, and PM20D1), each of the genes were experimentally screened for a functional interaction with LRRK2 (
Because GTPases such as RAB7L1 are typically only active in the GTP-bound state, mutant forms were generated that are constitutively active (CA; Q67L; this mutation is deficient in GTPase activity) or inactive (IN; T2 IN; a mutation within the presumptive GTP binding site). As expected, overexpression of the CA RAB7L1, but not IN RAB7L1, significantly suppressed the LRRK2 mutation-induced neurite length phenotype. Of other Rab family members, expression of RAB3A or RAB5A failed to rescue the phenotype, whereas RAB7 CA was effective in suppressing the process length shortening induced by LRRK2 mutation (
Next more direct evidence of a physical interaction between LRRK2 and RAB7L1 was sought and thus co-immunoprecipitation studies were performed. Epitope-tagged forms of LRRK2 and RAB7L1 (3×Flag-LRRK2 and GFP-RAB7L1) were co-transfected into HEK293T cells, and after 48 hrs, cell lysates were immunoprecipitated with an anti-Flag antibody and then probed for RAB7L1. Flag-immunoprecipitation of LRRK2 effectively co-precipitated RAB7L1 (
In vitro fluorescence microscopy studies were consistent with the presence of RAB7L1 and LRRK2 in common subcellular compartments. GFP-tagged RAB7L1, transfected into SH-SY5Y cells, localized primarily to the Golgi apparatus (as identified with the Golph4 marker), as well as along tubular structures emerging from Golgi apparatus, consistent with prior reports (Spano et al., 2011). LRRK2 staining appeared more diffuse than RAB7L1 but there was significant overlap (
In Vivo Analysis of a LRRK2-RAB7L1 Pathway in Drosophila Dopamine Neurons
To pursue potential mechanisms of LRRK2 pathology in vivo, a Drosophila model was established. Although transgenic mouse models expressing mutant LRRK2 have been widely described (Andres-Mateos et al., 2009; Li et al., 2009; Piccoli et al., 2011; Tong et al., 2009), these do not show consistent neurodegenerative phenotypes. Dopamine neuron-selective expression of human familial PD-associated G2019S-mutant LRRK2—using either a tyrosine hydroxylase (TH) (Friggi-Grelin et al., 2003) or dopa decarboxylase (DDC) promoter-Gal4 driver (Fischer et al., 1988)—induced premature mortality of young adult animals (
Subsequently a targeted screen for potential genetic modifiers of the LRRK2 G2019S mutant phenotype was performed, based on the idea that LRRK2 may modify a specific intracellular trafficking process, and focused on RAB7L1. A series of 16 Drosophila Rab genes, (see Table 4; out of 33 identified in Drosophila), or CA or IN forms of these (Zhang et al., 2007), were investigated.
Briefly, LRRK2 G2019S mutants were mated with a panel of previously described transgenic Drosophila strains that allow for overexpression of wild-type (WT) or constitutively active (CA), forms of the Rab genes (Zhang et al., 2007), using a standard balancer chromosome-based mating scheme. Co-expression of a majority of these Rab transgenes with LRRK2 within dopamine neurons produced no effect on the survival of animals co-expressing LRRK2 G2019S (
Next, dopamine neuron survival at the dorsomedial posterior protocerebral (PPM1) and dorsolateral posterior protocerebral (PPL1) clusters of Drosophila CNS mushroom bodies was quantified in terms of the loss of expression of a dopamine neuron-specific nuclear localization signal (NLS)-GFP marker protein, using fluorescent confocal microscopy analysis of whole mounted tissue. Expression of LRRK2 G2019S, but not the WT form, led to the preferential loss of neurons in the dorsomedial cluster, reminiscent of the phenotype in other Drosophila models of PD (Feany and Bender. 2000). Co-expression of CA RAB7L1 rescued the LRRK2 G2019S dopamine neuron loss phenotype (
PARK16 Risk Variants Modify RAB7L1 Splicing and Expression
The combination of human brain transcriptomic, human genetic, and model system studies support a role for PARK16, and specifically the PARK16 locus gene RAB7L1, in a pathway with LRRK2. Next possible molecular mechanisms at play at the PARK16 locus that may be responsible for a link between common genetic variants, RAB7L1 function, and PD risk were investigated. A challenge to this is that typically many variants at a given chromosomal location are so closely associated (in ‘linkage dysequilibrium’) so as to make impossible the identification of which is truly ‘causal’ rather than just coincidental. On reanalysis of existing genome-wide splicing data from human lymphoblasts (Montgomery et al., 2010), the PD-associated PARK16 haplotype was found to be associated with alternative splicing of RAB7L1, characterized by the skipping of exons 2 and 3. It is noted that a common SNP variant within the PARK16 locus, rs1572931, that is in linkage dysequilibrium with SNP rs947211 (Hamza et al., 2010) and thus similarly linked to PD risk, falls precisely within regulatory sequences for splicing at the Intron1-exon2 boundary (
Exon skipping is predicted to lead to the formation of a truncated form of RAB7L1 protein that lacks the predicted GTP-binding domain in the amino-terminal region (
Lysosomal Changes and Retromer-Associated Sorting Defects in LRRK2 and RAB7L1 Mutant Neurons
A cellular role for the LRRK2-RAB7L1 pathway was investigated. Prior studies have broadly implicated both of these gene products in intracellular sorting (Sakaguchi-Nakashima et al., 2007; Spano et al., 2011). Expression of the LRRK2 G2019S clinical mutation in rat primary neurons induced lysosomal swelling, as quantified by immunostaining for the lyosomal marker LAMP2 or using the lysosomotropic dye Lysotracker, consistent with prior work and other studies (Dodson et al., 2012; MacLeod et al., 2006; Stafa et al., 2012) (
MPR is typically recycled between the endolysosome compartment and the Golgi apparatus by the retromer complex (Arighi et al., 2004; Bonifacino and Hurley, 2008; Seaman, 2009; St. George-Hyslop et al., 2009). Given the primary apparent localization of RAB7L1 to the Golgi apparatus (
The retromer complex is required for retrograde transport of selective cargo—including MPR—between lysosomes and the Golgi apparatus, through endosomal intermediates, in mammalian cells (
The functional relationship of VPS35 with the LRRK2-RAB7L1 pathway was further investigated in the context of neurite process maintenance. In rat primary neurons, overexpression of VPS35 alone did not directly modify neurite process length, but effectively suppressed the loss of neurite processes in the context of LRRK2 G2019S expression or RAB7L1 knockdown (
Reduction in Retromer Complex Component Levels in the Context of LRRK2-RAB7L1 Pathway Defects.
Next potential molecular mechanisms for the apparent defects in retromer pathway function in the context of LRRK2 G2019S mutation or RAB7L1 knockdown were investigated. In mouse N2A neuroblastoma cells, expression of LRRK2 G2019S or knockdown of RAB7L1 led to a significant reduction in the levels of accumulated VPS35 as well as VPS29, a second component of the retromer complex (
Although the precise mechanism by which the LRRK2-RAB7L1 pathway impacts retromer complex function and levels remains to be determined, co-immunoprecipitation studies of LRRK2 with VPS35 support a direct interaction between these proteins: Lysates from SH-SY5Y cells co-expressing epitope-tagged V5-LRRK2 (or vector) and eGFP-VPS35 forms, were immunprecipitated for the eGFP tag. Subsequent Western blotting revealed co-purification of LRRK2 with eGFP-VPS35 (
To relate those findings to sporadic PD, VPS35 levels in PD or unaffected human brain tissue were analyzed. Firsta meta-analysis of substantia nigra (SN) mRNA expression levels in 5 publically available microarray gene expression datasets from patients and controls was carried out (Table 5: totally 144 individuals, 63 unaffected individuals and 81 PD patients), and a highly significant decreased in VPS35 mRNA levels (
Such a decrease was also observed in gene expression data from laser-microdissected PD SN dopamine neurons, when compared to similar cells isolated from unaffected patients (
Using a brain transcriptomic approach as a starting point, evidence is provided that the impacts of several distinct PD risk-associated common genetic variants are overlapping, even in unaffected PD-free carrier tissue. This points to a convergent pathway of action for such variants. Focusing subsequently on LRRK2 and the PARK16 locus gene RAB7L1, in vitro and in vivo studies support a functional interaction: these gene products bound together and functionally interacted in the regulation of neurite process length in vilro, as well as in the context of dopamine neuron survival in vivo. The impact of LRRK2 and PARK16 variants on brain gene expression was observed even in unaffected carriers of the PARK16 or LRRK2 locus risk variants suggesting the existence of a pre-disease prodromal state in such carriers, that favors subsequent progression.
The most prominent neuronal sorting phenotypes observed in the context of PD-associated LRRK2-RAB7L1 pathway changes were at lysosomes and the Golgi apparatus. Without being bound by theory, the proximal site of action for these proteins may be in defective retromer function at the Golgi apparatus, given the enrichment of both proteins at this structure. Trafficking of MPR to the Golgi apparatus—a function of the retromer complex—is defective, and associated with lysosomal swelling. Although the precise mechanism of retromer dysfunction is unclear, retromer pathway components including VPS35 appear reduced in the context of LRRK2 mutation or RAB711 knockdown. Recently described familial PD-associated clinical mutations in VPS35 phenocopy the deficits associated with LRRK2-RAB7L1 pathway dysfunction, whereas overexpression of VPS35 can rescue such deficits. It is also noted that RAB7 was identified in both the in vitro and in vivo screens of RAB proteins as suppressing the phenotype of LRRK2 mutant pathology, albeit less robustly than RAB7L1. RAB7 is the only RAB protein previously implicated in the regulation of retromer function (Rojas et al., 2008).
Prior studies have supported a role for LRRK2 in vesicular trafficking (Biskup et al., 2006; Dodson et al., 2012; Higashi et al., 2009; MacLeod et al., 2006; Stafa et al., 2012). However, cellular mechanisms of LRRK2 relevant in human brain—and in the context of PD or PD risk variants—have remained unclear. The studies herein are unusual in pursuing a PD genetic pathway using both human brain and model system analyses. A genetic interaction between LRRK2 and RAB7L1 was identified in the context of PD risk, and variants at the loci of these genes impact the brain transcriptome in an overlapping manner. Subsequent cell and animal model studies support a model where LRRK2 and RAB7L1 defects may modify intracellular sorting and retromer pathway function.
It is possible that PD-related defects in LRRK2 and RAB7L1 adversely impact aspects of vesicular trafficking unrelated to retromer function. Nonetheless, inducing retromer function appears sufficient to rescue cellular defects and neuronal survival in these models, suggesting a therapeutic venue in PD patients. It is interesting to note that VPS35 deficits, as well as genetic variants at retromer complex receptor loci such as SORLA (Rogaeva et al., 2007), have also been associated with a second major neurodegenerative disorder, Alzheimer's disease (Muhammad et al., 2008); this suggests a broader role for retromer dysfunction in neurodegeneration. Without being bound by theory, different cargos may be involved in the association of the retromer pathway with distinct pathological processes in Alzheimer's and Parkinson's. To this end, it is of interest to investigate the impact of such retromer dysfunction on aSyn and other proteins associated with PD pathology.
Drosophila Methods
Drosophila were cultured by standard methods on yeast-cornmeal-agar medium at 25° C. Wild-type and mutant G2019S LRRK2 transgenes were expressed specifically in catecholaminergic neurons, including dopamine neurons, using the Gal4-UAS system described (Fischer et al., 1988). Driver lines used include OK6 (motor neuron), Gmr (eye), G14 (muscle), TH (dopaminergic neuron), and DDC (dopaminergic neuron). A UAS-GFP::nuclear localization sequence (NLS) marker was used to visualize nucleii of cells in which trangenes were expressed (stock 4775 (w 1118; P{UAS-GFP.nls}14), Drosophila Stock Center, Bloomington, Ind.). For the RAB screen, UAS-LRRK2 (G2019S) transgenic Drosophila, crossed with the TH-Gal4 driver, were screened against a UAS-Rab transgenic library (Zhang et al., 2007). Crossings were typically performed using standard balancer chromosome techniques. To generate strains in which the homozygous LRRK2 transgene and another (Driver or marker) transgene lay on the same chromosome (III), genetic recombination was using standard techniques. Adult Drosophila mushroom bodies were dissected as in (Wu and Luo, 2006) and imaged immediately, without fixation, using a Zeiss LSM510 Meta confocal fluorescent microscope. For mortality curves, transgenic Drosophila surviving through adult metamorphosis were counted daily, from the day of pupal eclosion onward. Locomotion deficits were assessed by methods know in the art.
Primary Neurons Culture
Sprague-Dawley rat or mouse PI primary dissociated cortical cultures were prepared and transfected essentially as described (Xia et al., 1996) with the following modifications: cells were plated at high density, approximately 250,000 cells/cm2, in 24-well plates with 500 ul medium/well. Culture medium used for plating cells was Neurobasal-A supplemented with 2% B-27 and 10% FBS. At 1 day after plating, medium was changed to reduced serum (1% FBS+added antimitotic agents: 70 μM uridine and 25 μM 5-fluorodeoxyuridine) and replaced weekly thereafter; for transfections no DMSO was added to the transfection mixture, cells were not subjected to glycerol shock, and a total of 3 μg plasmid DNA was used per well. Cells were fixed in 4% PFA and immunostained with mouse α-RAB7L1 (Santa Cruz, 1:100), and rabbit monoclonal α-LRRK2 (Michal J. Fox Foundation MJFF4, 1:100), then with appropriate fluorescent secondaries (Jackson, 1:1000-2000). Neurite length and neurite puncta (defined as swellings greater than 2 um in diameter) were counted for for at least 20 neurons per condition. Mean puncta number per neuron was normalized to total average neurite length versus wild-type LRRK2 transfected cells. Fluorescent microscopy was performed using a Nikon TE 2000-S microscope and a Zeiss LSM510 Meta confocal microscope. Images were analyzed using Image-Pro Plus (Mediacybernetics) software version 5.1.0.20.
Colocalization Analysis
Primary rat cortical neurons were cultured on glass coverslips, transfected, and fixed as previously described in this methods section. Cells were immunostained for MRP (Abcam #ab2733, 1:400), Golph4(Abcamab #28049, 1:500), Lamp2 (Sigma L0668, 1:500). Fluorescent microscopy was performed using a Zeiss LSM510 Meta confocal microscope. Images were analysed using NIH ImageJ software version 1.45.
Cell Culture, Transfection and Cytochemistry
HEK293T and SH-SY5Y cells were maintained in Dulbecco's modified Eagle's medium (DMEM, Invitrogen) supplemented with 10% fetal bovine serum and 1% penicillin/streptomycin at 37° C. in a 5% CO2 atmosphere. Transient expression was performed by transfecting the plasmids using Lipofectamine2000 (Invitrogen) according to the manufacturer's instructions. The transfected SH-SY5Y cells grown on glass coverslips for 24 hours were fixed with 4% paraformaldehyde in PBS for 30 minutes, washed three times with PBS and subjected to the observation of fluorescence. For immunostaining of golgi, fixed cells were blocked and permeabilized with PBS containing 0.1% TritonX-100 and 3% bovine serum albumin followed by incubation with anti-Golph4 polyclonal antibody (abcam) and Alexa Fluor 555 goat anti-rabbit IgG (Invitrogen). Staining of nuclei was performed by using SYTOX Orange nucleic acid stain (Invitrogen). Fluorescence was detected using Zeiss LSM 510 confocal microscope.
Immunohistochemistry and Signal Quantification
LRRK2 R1441C or Wt BAC transgenic mice (Li et al., 2009) (Jackson Laboratory) were sacrificed and perfused immediately with 4% PFA for 20 min. Brains were cut by vibratome into sections 60 μm thick. Sections were blocked in 5% NDS overnight at 4 C, then incubated with primary antibodies overnight at 4 C. Antibodies used were sheep monoclonal α-TH (Pelfreeze. 1:500), mouse a-RAB7L1 (Santa Cruz, 1:100), and rabbit monoclonal α-LRRK2 (Michal J. Fox Foundation MJFF4, 1:100). Sections were incubated at room temperature for 2 hours with appropriate fluorescent secondaries (Jackson Laboratories. 1:1000). Microscopy was performed with a Zeiss LSM510 Meta confocal. Fluorescence signal intensity was quantified using NIH ImageJ.
Human Autopsied Brain Samples
Cortical BA9 area brain samples were obtained from the New York Brain Bank and are detailed in Table 5. Anonymous, de-identified tissue from the brain bank was used.
Quantitative Real Time RT-PCR
RT-qPCR was done as described in (Rhinn et al., 2008) RAB7L1 ratio was quantified using ΔΔCt method using primers pairs: RAB7L1_Ex2_fw
and RAB7L1_Ex3_rv
RAB7L1_Ex4_fw
RAB7L1_Ex5_rv
for human brain samples.
Minigene Splicing Assay
The human SH-SY5Y neuroblastoma cell line (ATCC) was cultured following ATCC's instructions, plated at densities of 4.10e5 cells per well (48-well plates) in wells coated with 0.1% gelatin (Specialty Media, Millipore) 24 hours prior to transfections. Transfections were performed with Lipofectamine 2000 reagent (Invitrogen) following manufacturer's instructions. After transfection with plasmids encoding the reporter contruct, RNA was extracted using miRNeasy kit (Qiagen) and reverse transcribed using Superscript III reverse transcriptase (Invitrogen) following manufacturer's instructions. The eDNA was amplified by PCR using the following primers:
(Fw, complementary to exon1 of RAB7L1) and
(Rev., complementary to GFP CDS) and Accuprime high-fidelity polymerase (Invitrogen) following manufacturer's instruction with an hybridization at 55 C and an elongation step of 1 min. Pictures from an ethidhium bromide stained agarose gels of the migrated PCR products was analyzed using ImageJ software.
Supplementary Experimental Procedures
Western Blots
Mouse brain protein fractions were prepared as follows. Mouse striata were dissected and homogenized by motorized dounce in Krebs-Ringer buffer with 0.32 M sucrose, then centrifuged at 3000×g for 10 min. Supernatant was collected and centrifuged at 10,000×g for 30 min. Pellet was resuspended in NuPage loading buffer (Invitrogen). Human brain proteins were prepared from frozen blocks using RIPA reagent (Pierce) following manufacturer's instruction. SDS-Page and Western Blot were performed according to manufacturer's protocols with NuPage Bis-Tris Mini Gel and Xcell II Blot Module (Invitrogen). Antibodies used include: LRRK2 (MJFF #1 & #2, 1:200), Rab5 (Abcam ab18211, 1:500), RAB7L1 (clone 2B8, Sigma, 1:400, clone 31-E, Santa Cruz sc-81924, 1:400), anti-Flag M2 (Sigma, 1:1000), anti-GFP (Covance, 1:1000), anti-alpha-tubulin (DM1A, 1:2000), SNAP25 (Abcam ab41455, 1:500), VAMP2 (Abcam ab3347, 1:500), beta-actin (clone C4) (Abcam ab3280, 1:800) and appropriate HRP-conjugated secondaries (Jackson, 1:2000). Blots were visualized using Supersignal luminol substrate (ThermoScientific #34075).
Immunoprecipitation
For cultured cells, HEK293T cells transfected for 48 hours were lysed with lysis buffer containing 0.5% Triton-X. 1 mM EDTA and protease inhibitor cocktail (Sigma). The lysates were rotated at 4° C. for 1 hr followed by centrifugation at 20,000 g for 5 min. The supernatant was added to 30 ul (slurry volume) of Dynabeads protein G (Invitrogen) preincubated without (preclear) and with an anti-flag M2 monoclonal antibody (Sigma) and the mixture was rotated for 30 min at 4° C. The beads were washed three times with ice-cold PBS and subjected to immunoblotting.
For mouse tissue, whole brains were dissected and homogenized by motorized dounce at 0° C. in Invitrosol detergent (Invitrogen) and Ix Protease inhibitor cocktail (Pierce) according to manufacturer's protocol Lysate was incubated shaking for 30 min at 4° C. with gel beads (Pierce Co-IP kit #26149) covalently conjugated to LRRK2 antibody (either MJFF #2 or #4) or a control IgG antibody. Beads were washed 4×10 min each, and then eluted. Eluant was analyzed by Western Blot, probed for LRRK2 (MIFF #1, 1:200), Rab7L1 (Santa Cruz sc-81924, 1:400), Rab11 (Abcam ab3612, 1:400), and beta-actin (clone C4) (Abcamab3280, 1:600).
DNA Constructs
The plasmid encoding rat RAB7L1 cDNA sequence was purchased from Open Biosystems, and the sequence was digested and ligated into BgIII-EcoRI site of pEGFP-C1 expression vector (Clontech) to generate N-terminally GFP-tagged RAB7L1. As the purchased RAB7L1 sequence contained 286 bp insertion in the middle of cDNA resulting in the generation of stop codon, this insertion was removed by a long-PCR protocol. The plasmids encoding constitutive active (Q67L) and dominant negative (T2 IN) rat RAB7L1 were generated by using site-directed PCR-mutagenesis kit (Stratagene) from the plasmid encoding N-terminally GFP-tagged wild-type RAB7L. All sequences were verified by DNA sequencing. Plasmids encoding wild-type and mutant Rab7 constructs were from Addgene; Rab3 and Rab5 constructs were also used. Plasmids encoding full-length human LRRK2 (wild-type, G2019S, K1906M) tagged with 3×FLAG at the N-terminus were used. Splice reporter minigene bearing plasmid was created by insertion of a synthesized sequence corresponding to the first exon, the first intron and the second exon and 200 bp of the second intron of human RAB7L1 gene in a pEGFP-N1 vector (Clontech) between its Xhol and HindIII restriction sites. Rab7L1 shRNA plasmid came from Sigma (MISSION shRNA clone NM_144875). LRRK2 plasmids used were those published (MacLeod et al., 2006), and confirmed.
polyA-RNAseq
Library generation and sequencing: First-strand cDNA was synthesized from 1 μg of RNA per biological sample using SuperScript III (Invitrogen) following manufacturer's instructions and using the pdT-FS oligonucleotide to prime the reverse transcription. Barcoded first-strand samples from different samples were then pooled and treated with RNase H (Invitrogen) at 37° C. for 20 minutes followed by 15 minutes at 75° C. to degrade RNA template. First-stand cDNA was then purified using QIAquick PCR Purification kit (Qiagen) in a total volume of 30 uL. Second-strand cDNA was synthesized from 25 uL of first-strand cDNA template by adding 10 μl 10× buffer 2 (NEB), 5 μl 10 mM dNTPs, 20 U Klenow Fragment (3′→5′exo-; NEB), 10 μl of 100 μM tagged 2nd strand primer (R-SS oligonucleotide:
with N=A,C,T,G mix (SEQ ID NO: 21)) and 46 μl water. The reaction mix was incubated at 37° C. for 30 minutes, followed by 10 minutes at 75° C. then cooled down at 4° C. Double-stranded cDNA was purified using PureLink PCR micro columns (Invitrogen) in a 30 uL volume. Illumina-compatible libraries were then generated by PCR from 25 uL of double-stranded cDNA template using Accuprime Pfx polymerase (Invitrogen) following manufacturer's instruction with NNSR forward
and NNSR reverse
primers. Thermo-cycling conditions were 2 min at 94° C. followed by 2 cycles of 94° C. for 10 s, 40° C. for 2 min, 68° C. for 1 min; 8 cycles of 94° C. for 10 s, 60° C. for 30 s, 68° C. for 1 min; 15 cycles of 94° C. for 15 s, 60° C. for 30 s, 68° C. for 1 min with an additional 10 s added at each cycle; and 68° C. for 5 min before cooling to 4° C. Amplified libraries were purified using PureLink PCR micro columns (Invitrogen) and directly used to generate clusters for sequencing-by-synthesis using the Illumina HiSeq 2000 platform. 100 bp single-end reads were obtained by sequencing to generate more than 300 million reads for the 34 samples.
Data was analyzed using Galaxy (Goecks et al., 2010): Illumina reads were converted to FASTQ Sanger format using FASTQ Groomer, the first 27 bp at their 5′ends of the reads were trimmed using FASTQ Trimmer to remove the polyA and adapters sequences and mapped to human hg19 genome using Burrows-Wheeler Alignment tools (Langmead et al., 2009) with Galaxy's default settings allowing 4% of missing alignments. All those tools are included in the Galaxy NGS toolset.
Human Sample Genotyping
DNA was extracted from brain samples using DNeasy kit (Qiagen) and amplified by PCR using primers RAB7L1_Genot_fw
and RAB7L1_Genot_rv
and Accuprime polymerase (Invitrogen) following manufacturer's instruction with an hybridization at 55° C. and an elongation step of 1 min. PCR products were purified using PureLink PCR columns (Invitrogen) submitted to Sanger sequencing (GeneWiz, NJ) using RAB7L1_Genot_fw primer and analyzed using SeqScanner (Applied Biosystems).
GWAS Epistasis Analysis
The AJ GWAS dataset included a total of 278 cases and 178 controls that were genotyped using the Illumina Human 610-quad bead arrays (Cases n=91 and controls n-96) or the Illumina Human 660-quad bead arrays (Cases n=191 and controls n=84). Details of the genotyping and quality control assessments are provided in Liu et al (2011). Subjects were participants in two studies the Genetic Epidemiology of Parkinson Disease and the AJ study. Ascertainment and a description of the study participants is provided in detail in Marder et al (Marder et al., 2003) and Liu et (Liu et al., 2011). All subjects in the GWAS AJ dataset were genotyped for the LRRK2 G2019S mutation and for GBA mutations common in the AJ population (N370S, L444P, 84insGG, IVS2+1 G>A, V394L, R496H, D409H, A456P and V460V). For the epistasis analysis LRRK2 and GBA mutation carriers were removed from the dataset. The final dataset is comprised of 239 PD cases and 178 controls.
In addition to the AJ dataset, 3 additional publicly available GWAS datasets were studied and downloaded from NCBI's dbGap repository (Mailman et al., 2007): NGRC (CIDR/NGRC Genes and Environment, dbGap phs000196.v2.p1, (Hamza et al., 2010)), that comprises 2013 cases and 1995 controls, NINDS (NINDS-Genome-Wide Genotyping in Parkinson's Disease, dbGap phs000089.v1.p1, (Fung et al., 2006)) that comprises 267 cases and 270 controls and Mayo (Mayo-Perlegen LEAPS (Linked Efforts to Accelerate Parkinson's Solutions) Collaboration, dbGap phs000048.v1.p1, (Maraganore et al., 2005)) that comprises 443 cases and 443 controls. All subsequent genetic analysis were done using gplink (Purcell et al., 2007) software. Epistasis between PARK16 (rs823114, as identified to modify PD age of onset in LRRK2 mutations carriers (Latourelle et al., 2011)) and LRRK2 (rs11176052 as identified by PD GWAS meta-analysis (Lill et al., 2012)) in each dataset was evaluated using epi function. As those SNPs were not present in the lower density Perlgen array used in the Mayo datasets, their best proxies were determined using SNAP in the 1000 genomes CEU population (see below); rs823154 and rs11174928 were used for the analysis in this dataset for PARK16 and LRRK2 respectively. Odd-ratios and their confidence intervals were evaluated using asso function. Meta-analysis and combination of p-values were done using Metal (http://www.sph.umich.edu/csg/abecasis/metal/).
SNP Selection
SNP-SNP pairwise linkage disequilibrium was assessed by SNAP phase (Johnson et al., 2008) using the CEU population panel from the 1000 genomes and HapMap dataset. PD associated SNPs were evaluated based on PDGene meta-analysis results (Lill et al., 2012).
GPI Analysis
Genome-wide SNP variant and gene expression data for 364 individuals were previously described (Myers et al., 2007). Normalized data corrected for covariates such as age, sex and batch effects were processed using R for gene expression analysis and gplink (Purcell et al., 2007) for genotypes. Subsequently for a given SNP, Pearson's correlation coefficient is calculated between the expression level of each gene (within the whole transcriptome dataset) and the allele load across the panel of samples. Associations were arbitrarily described with the high-risk variant at any given disease-associated SNP with positive values, and with the protective low-risk variant with negative values. As a consequence, a gene whose expression is consistently higher in samples from individuals who carry the disease-associated high-risk variant (relatively to the expression in the context of the protective low-risk variant) across the entire sample set will show a positive correlation coefficient (such as Gene 1 in
Formally, the GPI for a SNP is a n-vector of numerical values between −1 and 1, where n is a number of genes whose expression levels is available, and corresponds to the collection of the expression level correlation with the allelic load for each individual gene. The GPI of SNPx was thus calculated as
with
expression level of gene i across all samples, (aGi)j being the expression level of gene i in sample j
high-risk allele load of SNP x across all samples (ISNPx) being the high-risk allele load of SNP x in sample j.
(See
The intersection between the GPIs calculated for two SNPs is evaluated in a threshold-free approach by considering all the genes which show a correlation in the same direction for different GPIs. Formally, with GPISNPxX SNPy=GPISNPx∩GPISNPy:
In order to study potential interactions between two SNPs, a quantitative trait was defined for which classical genetic interaction analysis could be applied.
A genetic interaction is broadly defined as when the combined phenotypic effect of two mutations (in distinct genes) is not equal to the sum of the two individual phenotypic effects. Thus, such a non-additive interaction can either represent synergy (the combined effect is greater than the sum of its parts) or occlusion (the combined effect is less than the sum of its parts). The prediction for an occlusive genetic interaction is that the transcriptome effect of a risk allele at either one of the 2 genes will preclude the effect of a second risk allele.
A quantitative trait phenotype was defined for the classical genetic interaction analysis. This is most simply done by examining gene expression values that are highly impacted in common by the 2 SNPs individually (as identified above by the GPI intersection genes), and then querying the effect of their combination. Without being bound by theory, any of the gene expression values from the GPI intersection could be queried for a genetic interaction. Rather than querying individual genes expression phenotypes, a single scalar value was generated that represents the combined effect on the expression patterns of all of the relevant genes (as defined by the GPI analysis above; we used the genes most significantly impacted with p<0.01, empirically assessed by resampling). To compute this scalar value, termed the expression quantitative trait (eQT), a standard linear algebra manipulation was used: the combined quantitative trait is the sum of the expression levels of the selected genes, weighted by their GPI intersection coefficients (which reflects how consistently and strongly they are affected by both SNPs).
Formally, the complex expression phenotype for sample j will be:
with a selection of M genes from GPIsNPxX SNPy and tm the position in the GPIs vector of the mth highest absolute value in GPIsNPxX SNPy.
To actually perform the interaction analysis, we first determine the genotypes for the two SNPs of interest and then proceeded to linear model regression for the quantitative trait across all samples. Computationally, the effect of both SNPs on the quantitative phenotype was assessed using R lm function, by fitting of the linear model CEPxy˜x0+x1·LSNPx+x2·LSNPy+x3·LSNPxLSNPy. The test for interaction is based on the significance associated with the coefficient x3.
Disease Association Expression Profiles
For a given disease dataset, Pearson's correlation coefficient is calculated between the expression level of each gene (within the whole transcriptome dataset) and the disease phenotype across the panel of samples. Associations with the disease were arbitrarily described as positive values, consistently with the orientation assigned in the GPI calculation to the high-risk allele load of a disease-associated SNP. As a consequence, a gene whose expression is consistently higher in disease samples than in unaffected will show a positive correlation coefficient. By assessing the correlation coefficients across the entire transcriptome for a given variant, a global disease profile (GDP) can be obtained.
Formally, the GDP produces an object of the same class as the GPI, a n-vector of numerical values between −1 and 1, where n is a number of genes whose expression levels is available, and corresponds to the collection of the expression level correlation with the disease phenotype (0 for unaffected, 1 for disease) across the samples. Formally,
with PD=[(PD)1 . . . (PD)p], binary phenotype associated to disease D across all samples, (PD)j being the disease-associated binary phenotype in sample j.
and r(AG1, PD) the Pearson correlation coefficient between the expression level of gene i and the disease-phenotype across all samples. As a consequence, a gene whose expression level is increase in the course of the disease will be associated to a positive correlation in the disease expression profile. When multiple Affymetrix probesets were available for a given gene, the probeset showing the highest expression level was systematically selected. For resampling procedures, the values of the phenotype vector are randomly reattributed to the different samples (label switch).
Datasets of normalized gene expression (accession numbers GSE20168, GSE7621, GSE1297, GSE3790, GSE12654) were downloaded from the Gene Expression Omnibus website (http://www.ncbi.nlm.nih.govigeo/).
Similarity between a disease expression profile and a GPI intersection is evaluated by the Pearson correlation between the GPI intersection and the GDP across the subset of genes that show the highest absolute value in the GPI intersection. (In the case of the 7 PD SNPs intersection, the top 135 genes out of the 352 non-null were selected as a core set, with a FDR<5% based on resampling analysis of a 7 SNPs GPI intersection size). All data manipulations and analysis were done using R.
SNP within Probes
Common SNPs within the target sequences of microarray probes have indeed emerged as a potential technical issue for eQTL analysis in recent years (Alberts et al., 2007; Chen et al., 2009), due to the mis-hybridization caused by the allelic variant of such a SNP that does not match the designed target sequence; as a consequence of the poorer hybridization of the probe to its target sequence, the amount of target sequence might be under-evaluated. Classical eQTL studies aim at identifying relationships between the allelic load of a given variant (herein called “studied variant”) and the level of expression of a given gene. In the case of such eQTL studies, results can be biased if the allele leading to a poorer hybridization segregates with one allele of the studied SNP. This most often happens for cis-eQTL, as the local physical structure of the chromosome can lead to a systemic segregation between the studied variant and the one within the probe if those are in linkage disequilibrium. The GPI analysis can be seen as a globalization at a transcriptome-wide scale of eQTL studies, where the effect of a studied variant is considered on transcriptome-wide gene expression levels in a single measurement. As all the genes are considered with the same weight, there are two direct implications to that 1) the global measurement should be robust to potential technical issues (such as SNP-in-Probe) affecting a single probe, as this will only affect a fraction of a percent of the total GPI signal 2) the GPI is mostly based on trans-effect measurements, as more than 99% of the genes will be considered as “trans” by reference to any studied variant.
To empirically support the robustness of the GPI to SNPs in probes, all the probes sequences used in the study were obtained from Illumina, and were mapped on the human genome using Burrows-Wheeler Alignment (Langmead et al., 2009) to identify those that target sequences containing a SNP whose minor allele frequency is superior to 5% in HapMap Caucasian populations (Consortium, 2003). The whole analysis was then reproduced by excluding the 272 probes satisfying those criteria, and the same results were obtained as the one presented in the manuscript in
This application claims priority to U.S. Application Ser. No. 61/751,435 filed Jan. 11, 2013, the contents of which is hereby incorporated in its entirety.
The work described herein was supported in whole, or in part, by National Institute of Health Grant Nos. NS064433 and NS060876. The United States Government has certain rights to the invention.
Filing Document | Filing Date | Country | Kind |
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PCT/US2014/011226 | 1/13/2014 | WO | 00 |
Number | Date | Country | |
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61751435 | Jan 2013 | US |