Patent Application
20170051031
New analogs of prolactin releasing peptide (PrRP) represent neuroprotective agents for peripheral treatment and prevention of neurodegenerative diseases, such as Alzheimer's disease (AD), Parkinson's disease (PD), cognitive impairment no dementia (CIND), brain trauma, and neurodegenerative changes and disorders.
AD is a serious neurodegenerative brain disease affecting mainly older people. The disease starts to manifest with memory decline, learning disorders, behavioral changes, impairment in orientation in time and space, loss of autonomic functions, finally results in complete dementia. The death comes on average 9 years after diagnosis. Histopathologically, AD is characterized by two hallmarks: intracelullar neurofibrilary tangles formed by hyperphosphorylated Tau protein and extracellular senile plaques of beta peptide.
Prolactin releasing peptide (PrRP) was discovered at the end of 20th century. Naturally two isoforms of PrRP can be found in organism: peptide containing 31 amino acids (PrRP/1-31/; PrRP31) or 20 amino acids (PrRP/12-311; PrRP20), its amino acid composition also exhibits small differences in various species (human, rat, bovine) (Hinuma et al., 1998). PrRP is produced in neurons of many brain regions, mainly in medulla oblongata (in nucleus tractus solitarius and ventrolateral reticular nucleus), and hypothalamus (in paraventricular and dorsomedial nuclei), less in pituitary gland, and amygdala. In the periphery PrRP can be found in adrenal medulla, testis, pancreas, and small and large intestines.
PrRP receptor, GPR10, is extensively expressed in the whole brain; it can be found in anterior pituitary, amygdala, hypothalamus, brainstem, and medulla oblongata. In the periphery GPR10 can be found in adrenal medulla, and significantly increased expression was observed in human and rat pancreas.
Subsequently, new modified analogs of neuropeptides PrRP31 and PrRP20 were synthesized, with changes in amino acid chain, lipidated with fatty acid (e.g. myristoylated or palmitoylated) at the N-terminus, however, for use in regulating food intake (WO2014/009808) and regulating blood glucose levels (U.S. Pat. No. 61/927944).
Nowadays, drugs slowing the AD progression and improving cognitive functions are used. These are inhibitors of acetylcholinesterase, which increase acetylcholine concentration in the brain and inhibitors of N-methyl-D-aspartate receptors (e.g. memantin). Because of the high incidence of insulin resistance in AD patients, it is not possible to use insulin as an AD treatment. It is hypothesized that agents increasing insulin sensitivity, such as metformin, insulin secretagogues such as glucagon-like peptide-1 (GLP-1 gastric-inhibitory peptide (GIP and their analogs could act as AD treatment.
There is a need to provide further substances with neuroprotective effect which could be useful in the treatment of neurodegeneravie diseases.
The present invention provides lipidated neuropeptides based on prolactin-releasing peptide (PrRP-based neuropeptides) selected from prolactin-releasing peptide 20 (PrRP20), prolactin-releasing peptide 31 (PrRP31) and their analogs, wherein in the C-terminal sequence IRPVGRF-NH2 (SEQ ID NO. 1), one or more of isoleucine, valine and phenylalanine can be replaced by another amino acid; said PrRP-based neuropeptide containing C14 and/or C16 fatty acid chain, said fatty acid is bound in position 1 or 11 for PrRP31 or its analogs and in position 1 or 7 for PrRP20 or its analogs; said fatty acid being bound by a bond between an amino acid having at least one free NH2, OH or SH group and the carboxylic group of the fatty acid or through a hydrophilic linker X2 selected from the group comprising polyoxyethylene moiety, arylalkyl moiety, or a saturated or unsaturated, linear or branched C3-C8 hydrocarbon chain, wherein some carbon atoms may be replaced by heteroatoms selected from a group comprising N, S, and O; said chain carrying at least one and preferably two amino groups or carboxylic acid groups, one of which may be substituted to form a group selected from: CONH2; NH-polyoxyethylene; COOM1 wherein M1 is alkali metal, preferably Na or K; CN; COOR1, COR1, or CONHR1 wherein R1 is selected from a group comprising lower alkyl, arylalkyl, polyoxyethylene, methylpolyoxyethylene, and aminoethylpolyoxyethylene; (CHOH)nR2 where R2 is H or COOH and n is an integer from 2 to 10; or (CH)nN+R3, wherein R3 is the same or different, selected from H and C1-C4 alkyl;
and the PrRP31 or its analogs may optionally have the amino acid in position 11 replaced by an amino acid having a free NH2, OH or SH group, particularly when the fatty acid is bound in position 11 for PrRP31 or its analogs; and the PrRP20 or its analogs may have the amino acid in position 7 replaced by an amino acid having a free NH2, OH or SH group in position 7, particularly when the fatty acid is bound in position 7 for PrRP20 or its analogs; for use in a method of treatment and prevention of neurodegenerative diseases, such as Alzheimer's disease (AD), Parkinson's disease (PD), cognitive impairment no dementia (CIND), brain trauma, and neurodegenerative changes and disorders.
The PrRP31 and/or PrRP20 include variants found in various animal species. Preferred are the human and rat variants.
Preferably, in the sequence of the C-terminal heptapeptide as mentioned above, isoleucine can be replaced by phenylglycine or alanine, valine can be replaced by phenylglycine and/or terminal phenylalanine can be replaced by dichlorophenylalanine, pentafluorophenylalanine, nitrophenylalanine, histidine, benzylhistidine, naphthylalanine, tryptofane, pyroglutamic acid, benzylcysteine, benzyl-O-glutamate, tetrachlorophenylalanine, methyl-O-phenylalanine or methyl-NH-phenylalanine.
The binding of the fatty acid thus includes either a direct bond between an amino acid of the PrRP chain having at least one free amino, SH or OH group and the carboxylic group of the fatty acid, or a bond through X2, wherein X2 is a hydrophilic linker selected from a group comprising polyoxyethylene moiety, arylalkyl moiety, or a saturated or unsaturated, linear or branched C3-C8 hydrocarbon chain, wherein some carbon atoms may be replaced by heteroatoms selected from a group comprising N, S, and O; said chain carrying at least one and preferably two amino groups or carboxylic acid groups, one of which may be substituted to form a group selected from: CONH2; NH-polyoxyethylene; COOM1 wherein M1 is alkali metal, preferably Na or K; CN; COOR1, COR1, or CONHR1 wherein R1 is selected from a group comprising lower alkyl, arylalkyl, polyoxyethylene, methylpolyoxyethylene, and aminoethylpolyoxyethylene; (CHOH)nR2 wherein R2 is H or COOH and n is an integer from 2 to 10; or (CH)nN+R3, where R3 is the same or different, selected from H and C1-C4 alkyl.
Preferably, X2 is a hydrophilic linker selected from the group comprising β-alanine, γ-aminobutyric acid and γ-glutamic acid.
When the fatty acid is bound in position 11 for PrRP31 or its analogs, the PrRP31 or its analogs have an amino acid having a free NH2, OH or SH group in position 11, and when the fatty acid is bound in position 7 for PrRP20 or its analogs, the PrRP20 or its analogs have an amino acid having a free NH2, OH or SH group in position 7. Amino acids having a free NH2, OH or SH group include, for example, lysine, arginine, serine, cysteine, tyrosine.
The present invention provides, more particularly, the lipidated analogs of PrRP20 or PrRP31 (rat and human) according to the formulae:
wherein X═X1 or X1X2; X1 being tetradecanoic or hexadecanoic acid, which is bound in a position 1 to an amino acid of the above mentioned peptide chain either directly or through X2, X2 being a hydrophilic linker as defined above, preferably selected from the group consisting of β-alanine, γ-amino butyric acid and γ-glutamic acid, and wherein in the C-terminal sequence IRPVGRF-NH2, one or more of isoleucine, valine and phenylalanine can be replaced by another amino acid;
for use in the treatment and prevention, preferably by peripheral administration, of neurodegenerative diseases, which are Alzheimer's disease (AD), Parkinson's disease (PD), cognitive impairment no dementia (CIND), brain trauma, and neurodegenerative changes and disorders.
In a preferred embodiment, the lipidated analogs of PrRP20 or PrRP31 according to the formulae:
wherein palm is hexadecanoic acid, and
wherein in the C-terminal sequence IRPVGRF-NH2, one or more of isoleucine, valine and phenylalanine can be replaced by another amino acid;
are provided for use in the treatment and prevention, preferably by peripheral administration, of neurodegenerative diseases, which are Alzheimer's disease (AD), Parkinson's disease (PD), cognitive impairment no dementia (CIND), brain trauma, and neurodegenerative changes and disorders.
In another embodiment, the lipidated analogs of PrRP20 or PrRP31 according to the formulae:
wherein palm is hexadecanoic acid and X2 is γ-glutamic acid, and
wherein in the C-terminal sequence IRPVGRF-NH2, one or more of isoleucine, valine and phenylalanine can be replaced by another amino acid;
are provided for use in the treatment and prevention, preferably by peripheral administration, of neurodegenerative diseases, which are Alzheimer's disease (AD), Parkinson's disease (PD), cognitive impairment no dementia (CIND), brain trauma, and neurodegenerative changes and disorders.
A further embodiment of the invention relates to the use of lipidated neuropeptides based on prolactin-releasing peptide (PrRP-based neuropeptides) selected from prolactin-releasing peptide 20 (PrRP20), prolactin-releasing peptide 31 (PrRP31) and their analogs, wherein in the C-terminal sequence IRPVGRF-NH2, one or more of isoleucine, valine and phenylalanine can be replaced by another amino acid; said PrRP-based neuropeptide containing C14 and/or C16 fatty acid chain, said fatty acid is bound in position 1 or 11 for PrRP31 or its analogs and in position 1 or 7 for PrRP20 or its analogs; said fatty acid being bound by a bond between an amino acid having at least one free NH2, OH or SH group and the carboxylic group of the fatty acid or through a hydrophilic linker X2 selected from the group comprising polyoxyethylene moiety, arylalkyl moiety, or a saturated or unsaturated, linear or branched C3-C8 hydrocarbon chain, wherein some carbon atoms may be replaced by heteroatoms selected from a group comprising N, S, and 0; said chain carrying at least one and preferably two amino groups or carboxylic acid groups, one of which may be substituted to form a group selected from: CONH2; NH-polyoxyethylene; COOM1 wherein M1 is alkali metal, preferably Na or K; CN; COOR1, COR1, or CONHR1 wherein R1 is selected from a group comprising lower alkyl, arylalkyl, polyoxyethylene, methylpolyoxyethylene, and aminoethylpolyoxyethylene; (CHOH)PR2 where R2 is H or COOH and n is an integer from 2 to 10; or (CH)nN+R3, where R3 is the same or different, selected from H and C1-C4 alkyl;
and the PrRP31 or its analogs may have the amino acid in position 11 replaced by an amino acid having a free NH2, OH or SH group, particularly when the fatty acid is bound in position 11 for PrRP31 or its analogs; and the PrRP20 or its analogs may have the amino acid in position 7 replaced by an amino acid having a free NH2, OH or SH group in position 7, particularly when the fatty acid is bound in position 7 for PrRP20 or its analogs; for the manufacture of a medicament for treatment and prevention of neurodegenerative diseases, such as Alzheimer's disease (AD), Parkinson's disease (PD), cognitive impairment no dementia (CIND), brain trauma, and neurodegenerative changes and disorders.
Another embodiment of the invention provides a method of treatment and prevention of neurodegenerative diseases, such as Alzheimer's disease (AD), Parkinson's disease (PD), cognitive impairment no dementia (CIND), brain trauma, and neurodegenerative changes and disorders, comprising a step of administering to a subject in need of such treatment or prevention, preferably by peripheral administration, lipidated neuropeptides based on prolactin-releasing peptide (PrRP-based neuropeptides) selected from prolactin-releasing peptide 20 (PrRP20), prolactin-releasing peptide 31 (PrRP31) and their analogs, wherein in the C-terminal sequence IRPVGRF-NH2, one or more of isoleucine, valine and phenylalanine can be replaced by another amino acid; said PrRP-based neuropeptide containing C14 and/or C16 fatty acid chain, said fatty acid is bound in position 1 or 11 for PrRP31 or its analogs and in position 1 or 7 for PrRP20 or its analogs; said fatty acid being bound by a bond between an amino acid having at least one free NH2, OH or SH group and the carboxylic group of the fatty acid or through a hydrophilic linker X2 selected from the group comprising polyoxyethylene moiety, arylalkyl moiety, or a saturated or unsaturated, linear or branched C3-C8 hydrocarbon chain, wherein some carbon atoms may be replaced by heteroatoms selected from a group comprising N, S, and O; said chain carrying at least one and preferably two amino groups or carboxylic acid groups, one of which may be substituted to form a group selected from: CONH2; NH-polyoxyethylene; COOM1 wherein M1 is alkali metal, preferably Na or K; CN; COOR1, COR1, or CONHR1 wherein R1 is selected from a group comprising lower alkyl, arylalkyl, polyoxyethylene, methylpolyoxyethylene, and aminoethylpolyoxyethylene; (CHOH)nR2 wherein R2 is H or COOH and n is an integer from 2 to 10; or (CH)nN+R3, where R3 is the same or different, selected from H and C1-C4 alkyl;
and the PrRP31 or its analogs may have the amino acid in position 11 replaced by an amino acid having a free NH2, OH or SH group, particularly when the fatty acid is bound in position 11 for PrRP31 or its analogs; and the PrRP20 or its analogs may have the amino acid in position 7 replaced by an amino acid having a free NH2, OH or SH group in position 7, particularly when the fatty acid is bound in position 7 for PrRP20 or its analogs.
Statistical analysis is 2-way ANOVA with Bonferroni post hoc test. Significance is *P <0.05 and **P<0.01.
According to the structure-activity studies, analogs of PrRP31 and PrRP20, rat (identical to mouse) or human, lipidated at N-terminal or amino acid containing amino group, using C14 or C16 fatty acid. Methionine in position 8 in PrRP31 was replaced by more stable norleucine. In Thy Tau22 mice study, an analog of PrRP31 palmitoylated at Lys11 (Lys instead of Arg) through gamma glutamic acid linker (hereinafter referred to as LiPR31) was used.
Lipidated analogs of PrRP31 and PrRP20 were synthesized by solid-phase synthesis at the IOCB AS CR, Prague, on the peptide synthesis department, as described by Maixnerová et al. (Maletínská et al., 2007).
Liraglutide was purchased from Novo Nordisk A/S (Bagsvaerd, Denmark).
To examine neuroprotective properties, insulin resistant animal model was used, e.g. mouse model with obesity induced by MSG. These mice are characterized by growth hormone insufficiency, pituitary and optic nerves atrophy, and infertility (Olney, 1969). In their brains the reduced nucleus arcuatus, enlarged third brain ventricle, and narrowed eminentia mediana are observed. Total number of neurons in ARC is reduced about 75% in MSG mice compared to their controls; however, the number of neurons does not differ significantly in other brain regions (Elefteriou et al., 2003).
The imbalance between food intake and energy expenditure at MSG obese mice leads to hypophagia and an increased adipose tissue; compared to their control, MSG obese mice have even 8 times higher weight of white adipose tissue (Maletínská et al., 2006). They have also increased leptin and glucose blood concentration, and insulin resistance (Maletínská et al., 2006).
For evaluation of the the neuroprotecitve effect of palmitoylated PrRP LiPR31, the model of AD like pathology, Thy-Tau22 mice, was used. Thy-Tau22 mice overexpress human 4R-Tau protein with mutations G272V and P3015. These mice develop memory deficits, Tau hyper-phosphorylation at different epitopes, such as Ser202, Thr205, Thr212, Ser214, Thr231, Ser396, in CA1 region of hippocampus, and neurofibrillary tangles formation (Schindowski et al., 2006; Van der Jeugd et al., 2011).
Mice of strain NMRI (Harlan, Italy) were housed at the certified animal facility of IOCB AS CR, Prague, in the campus of Academy of Science in Kr{hacek over (c)} at 22±2° C., they had free access to water and food. They were fed standard chow diet St-1 (Mlýn Kocanda, Jesenice, Czech Republic), which contained 66% calories as carbohydrates, 25% as protein, and 9% as fat; its energy content was 3.4 kcal/g. Daily cycle was 12/12 hours, lights on at 6:00 a.m. All animal experiments followed the ethical guidelines for animal experiments and the Czech Republic Act No. 246/1992.
For obesity induction, the newborn NMRI mice were SC administered with sodium glutamic acid (Sigma, St. Louis, USA) at dose 4 mg/g of body weight at postnatal days 2-5. These MSG-obese mice were fed the same standard diet as the control group. The food and body weight was monitored once per week. For the study, MSG and control male mice at the age of 2 and 6 months were used.
6-Month-Old MSG Mice Treatment with Peptides Increasing Insulin Sensitivity
Groups of MSG mice (n=10 animals per group) were for 14 days SC administered with liraglutide at a dose 0.2 mg/kg, or palmitoylated analog of PrRP31 at a dose 5 mg/kg, or palmitoylated analog with PrRP31 with dichlorophenylalanin in position 31 at a dose 5 mg/kg dissolved in saline, twice a day, at 8 a.m. and 6:00 p.m. Control mice (n=10 animals per group), NMRI and MSG, were injected with saline (the volume was always 0.2 ml/mouse).
The spatial memory was tested using Morris water maze (MWM) following the protocol described in article of Vorheese and Williamse (Vorhees and Williams, 2006) in 6-month-old MSG mice and their age-matched controls.
Thy-Tau22 female mice and their age-matched WT controls (C57B1/6 origin) were a kind gift from INSERM laboratory, Lille, France, the research group “Alzheimer & Tauopathies”. Mice were obtained at the age of 7 months, and were housed 3-4 per cage in the certified animal facility of the Institute of Physiology AS CR, Prague, Czech Republic, with free access to water and Altromin diet (Altromin, Eastern-Westphalia, Germany). Daily cycle was 12/12 hours, lights on at 6:00 a.m. All animal experiments followed the ethical guidelines for animal experiments and the Czech Republic Act No. 246/1992.
Thy-Tau22 Mice Treatment with LiPR31
Thy-Tau22 mice were infused for 2 months with LiPR31, with doses 5 mg/kg/day dissolved in PBS/5% Tween 80 pH 6, using SC Alzet® osmotic pumps. Control mice were infused with PBS/5% Tween 80. Alzet® osmotic pumps were subcutaneously (SC) implanted in short-term ether anesthesia, and were changed after one months of experiment.
The spatial memory was tested before the beginning of the treatment with LiPR31, and after 2 months of the treatment, using the Y-maze. Experiment was performed following the protocol described by Belarbi et al. (Belarbi et al., 2011)
Overnight fasted mice with ad libitum access to water were weighed, and their plasma glucose concentration was measured using Glucocard glucometer. After decapitation, the brains were dissected on ice, and cut between hemispheres. For immunohistochemical staining the half of the brain was fixed for 24 hours in 4% paraformaldehyde and dehydrated in 70% ethanol, afterward. For the western blot (WB) analysis, the hippocampus was dissected, and lysed in cold lysis buffer (62.5 mmol.l−1 Tris-HCl, pH 6.8 with 1% sodium deoxycholate, 1% Triton X-100, Complete, 50 mmol.l−1 NaF, 1 mmol.l−1 Na3VO4), homogenized, sonicated 10 minutes and stored at −20° C. The blood plasma was prepared, and stored at −20° C.
Western Blot Analysis of Proteins Implicated in Insulin Signaling Cascade and Detection of Hyperphosphorylation of Tau Protein
In homogenized hippocampi the protein level was measured using BCA kit (Pierce, Thermo Fisher Scientific, Rockfor, Ill., USA), then the samples were diluted in sample buffer (62.5 mmol.l−1 Tris-HCl pH 6.8, 10% glycerol, 2% SDS, 0.01% bromfenol blue, 5% merkaptoethanol, 50 mmol/l NaF and 1 mmol/l Na3VO4) to final concentration 1 ug/μl. WB method and analysis of the results were performed according to Nagelova et al. (Nagelova et al., 2014). The list of the used antibodies and their dilution is shown in table 1.
To verify the results obtained from WB analysis the immunohistochemical staining was performed. 10 μm thick paraffin-embedded brain slices were prepared at INSERM, Lille, France. Immunohistochemical staining was performed according the method from Violet et al. (Violet et al., 2014).
Statistical analysis was calculated by 1-way ANOVA, with Dunnett post-hoc test, or by Student t-test, using GrapPad software (San Diego, Calif., USA). Data are presented as mean ±SEM.
MWM with 6-Month-Old MSG Obese Mice
The escape latency was measured in 6-month-old MSG mice and their age-matched controls. Experiment was performed 5 days with 4 sessions per day. As shown in
Insulin Signaling Activation and Tau Phosphorylation in Hippocampi of 2- and 6-Month-Old MSG Mice and Their Controls
Activation of insulin signaling cascade and Tau protein phosphorylation was measured by WB analysis in hippocampi of MSG obese mice and their controls aged 2 and 6 months. The phosphorylation of GSK-3β at Ser9 was detected. As shown in
Insulin Signaling Cascade in Hippocampi of 6-Month-Old MSG Mice after 14-Day Treatment with Palmitoylated Analog of PrRP31 and Liraglutide
Enhanced activation of kinases implicated in insulin signaling cascade was observed in hippocampi of 6-month-old MSG mice after 14-day intervention, either with palmitoylated analog of PrRP31, or with liraglutide, as shown in
Tau Phosphorylation in Hippocampi of 6-Month-Old MSG Mice after 14-Day Treatment with Palmitoylated Analog or PrRP31 and Liraglutide
Tau phosphorylation in hippocampi of 6 month-old-MSG mice after 14-day treatment was measured using WB analysis. In accordance with previous results, the increased phosphorylation of GSK-3β at Ser9 caused decreased phosphorylation of Tau protein at epitopes Ser396, Thr212 and Trh231 after 14-day-long treatment either with palmitoylated analog of PrRP31, or with liraglutide, as shown in
Phosphorylation of GSK-3β and Tau Protein at Epitope Thr231 in Hippocampi of 6-Month-Old MSG Mice after 14-Day-Long Treatment with palmitoylated analog of PrRP31 with Dichlorophenylalanin in Position 31
Phosphorylation was detected using the method of WB. As shown in
Immunohistochemical Fluorescent Double Staining of Tau Phosphorylation in CA1 Region of Hippocampi of 6-Month-Old MSG Mice after 14-Day-Long Intervention with Palmitoylated Analog of Prrp31 and Liraglutide
To evaluate the WB analysis the double immunohistochemical staining was used. As shown in
After 14-day treatment with palmitoylated analog of PrRP31 and liraglutide, the Tau phosphorylation is decreased in hippocampal region CA1, which is manifested by a weaker fluorescent signal, using the laser of the same intensity.
Spatial Memory Testing in Thy-Tau 22 Mice before and after the Treatment with LiPR31
The spatial memory was tested before and after the treatment with LiPR31 in Thy-Tau22 mice and their age-matched WT control using the Y-maze; the WT and Thy-Tau22 control group was treated with PBS/5% Tween 80. As shown in
Tau Phosphorylation in Hippocampi of 9-month-old Thy-Tau22 Mice after 2-Month-Long Treatment with LiPR31
Tau phosphorylation was determined in the hippocampi of Thy-Tau22 mice treated with LiPR31 and their Thy-Tau22 control using the method of WB. Compared to the control group, the attenuation of Tau phosphorylation at epitopes Thr231, Ser396 and Ser404 was observed in hippocampi of Thy-Tau22 mice treated for 2 months with LiPR31, as shown in
AD is characterized by two pathological changes in neurons: formation of non-soluble extracellular Aβ plaques and hyperphosphorylation of intracellular cytoskeletal Tau protein.
Within the framework of the present invention, the potential neuroprotective effect of tested compound was examined in the mouse model of obesity and insulin resistance, where obesity is caused by the application of monosodium glutamate (MSG) to newborn animals. Thy-Tau 22 mice, a model of AD like pathology, were also used to verify neuroprotective effect of tested compound.
Compounds increasing insulin sensitivity were tested regarding their effect on insulin signaling cascade and tau hyperphosphorylation in the brain (in hippocampus), in MSG obese mice before and after peptides application.
Compared to age-matched controls, the insulin resistance was observed in the brain of MSG obese mice. Decreased activation of insulin signaling cascade led to a decreased phosphorylation of GSK-313 at Ser9, which increased its kinase activity. GSK-3β is one of the most important kinases implicated in Tau phosphorylation. Consequently, hyperphosphorylation of Tau protein was observed at epitopes Ser396 and Thr231. After 14-day treatment with compounds increasing insulin sensitivity, which were palmitoylated analog of PrRP31, palmitoylated analog of PrRP31 with dichlorophenylalanin in position 31, and analog of GLP-1 liraglutide which served as a positive control, an enhanced activation of insulin signaling cascade, including increased phosphorylation of GSK-3β at Ser9, and decreased phosphorylation of Tau protein at epitopes Ser396, Thr212 and Thr231 was observed.
Tested analogs of palmitoylated PrRP enhanced insulin signaling cascade in the hippocampi of 6-month-old insulin resistant MSG mice after 14-day SC treatment. Attenuated Tau phosphorylation was also observed; Tau hyperphosphorylation is the pathological change found in brains of AD patients.
New analogs of prolactin releasing peptide (PrRP) represent neuroprotective agents for peripheral treatment and prevention of diseases, which are Alzheimer's disease (AD), Parkinson's disease (PD), cognitive impairment no dementia (CIND), brain trauma, and neurodegenerative changes and disorders.
Vorhees C V a Williams M T (2006), Nature protocols 1:848-858.
| Number | Date | Country | Kind |
|---|---|---|---|
| PV 2014-364 | May 2014 | CZ | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/CZ2015/000047 | 5/20/2015 | WO | 00 |
