Patent Application
20210085744
The interaction of diet and the gut microbiota to health have emerged in recent years. First, unlike other factors including disease and disease treatment, diet has been clearly demonstrated to have a considerable effect on the composition of the gut microbiota throughout human life (Sonnenburg & Bäckhed, 2016; Sonnenburg et al., 2016; Glenwright et al., 2017). Different human populations can have vastly different intestinal microbiomes, and changes in diet lead to changes in microbiota composition (Maslowski & Mackay, 2011). Second, owing to the essential role of the gut microbiota in maintaining host physiology, its alteration as a result of unhealthy diet can trigger a wide range of physiological disorders, including low-grade inflammation, metabolic disorders, and loss of insulin sensitivity, which increase the risk of developing metabolic diseases (Chassaing et al., 2012; Chassaing & Gewirtz, 2014; Huttenhower et al., 2014; Arrieta et al., 2015; Usami et al., 2015; Patterson et al., 2016; Tang et al., 2017). Third, vegetable and meat are mostly made of cells that contain high levels of nucleic acids including RNA (Hess & Greenberg, 2012; Garcia-Segura et al., 2013). Although it is well known that food, including edible plants, are the main carbon and energy source for gut microbes, the impact of dietary-derived RNA on the gut microbiota are not defined. If the interactions between diet-derived RNA and the microbiome in a sequence-specific manner are determined and understood, manipulation of the microbiome could be optimized for development of food-derived factor-based therapeutic strategies in restoring gut microbiota homeostasis with minimum side effects. Lastly, gene sequencing data have shown that the gut metagenome (that is, all the genes in the community of gut microorganisms) is involved in core functions, such as the digestion and degradation of otherwise indigestible nutrients (Tschop et al., 2009). Whether diet-derived RNA plays a dominate role during communication with gut microbiota rather than being utilized as a nutrient to health is less defined.
Well over half of the animal and human transcriptome is predicted to be under miRNA regulation. miRNA from edible plants has been detected in human blood (Zhang et al., 2012). Whether the expression of gut bacterial genes is regulated by edible plant miRNA is not known. An exosome-like nanoparticle (ELNs) complex (Ju et al., 2013; Record, 2013; Wang et al., 2013; Mu et al., 2014; Wang et al., 2014; Zhuang et al., 2015; Deng et al., 2017) that is present in foods has been described. The published data (Mu et al., 2014; Wang et al., 2014; Deng et al., 2017) further indicate that edible ELNs contain miRNAs (Mu et al., 2014). Little is known about whether the diet-derived ELN RNA communicates with gut bacteria to shape microbiota.
This summary lists several embodiments of the presently disclosed subject matter, and in many cases lists variations and permutations of these embodiments. This summary is merely exemplary of the numerous and varied embodiments. Mention of one or more representative features of a given embodiment is likewise exemplary. Such an embodiment can typically exist with or without the feature(s) mentioned; likewise, those features can be applied to other embodiments of the presently disclosed subject matter, whether listed in this summary or not. To avoid excessive repetition, this Summary does not list or suggest all possible combinations of such features.
In some embodiments, the presently disclosed subject matter provides methods for modulating gut microbiota. In some embodiments, the methods comprise administering to a subject an effective amount of a composition comprising a first edible plant-derived nanoparticle encapsulating an effective amount of RNA, optionally wherein the RNA is obtained from a second edible-plant derived nanoparticle, wherein the effective amount results in a change in the makeup of the subject's gut microbiota relative to that present prior to the administering step. In some embodiments, the first edible plant-derived ELN, the second edible plant-derived ELN, or both are derived from an edible plant selected from the group consisting of ginger, grapefruit, carrot, garlic, and turmeric. In some embodiments, the edible plant is ginger. In some embodiments, effective amount of RNA comprises and effective amount of an miRNA. In some embodiments, the miRNA is selected from the group consisting of miR166c, miRNA167a, miR319a, miR396e, miR842, and miR827. In some embodiments, the gut microbiota that is modulated is a Lactobacillaceae, a Bacteroidaceae, a Clostridiaceae, a Ruminococcaceae, or any combination thereof. In some embodiments, the modulating comprises increasing numbers of Lactobacillaceae and/or Bacteroidaceae, decreasing numbers of Clostridiaceae and/or Ruminococcaceae, or both in the gut microbiota of the subject.
In some embodiments, the presently disclosed subject matter also provides methods for preventing and/or treating gut dysbiosis. In some embodiments, the methods comprise administering to a subject an effective amount of a composition comprising a first edible plant-derived nanoparticle encapsulating an effective amount of RNA, optionally wherein the RNA obtained from a second edible-plant derived nanoparticle, wherein the effective amount results in a change in the makeup of the subject's gut microbiota relative to that present prior to the administering step, thereby preventing and/or treating gut dysbiosis in the subject. In some embodiments, the first edible plant-derived ELN, the second edible plant-derived ELN, or both are derived from an edible plant selected from the group consisting of ginger, grapefruit, carrot, garlic, and turmeric. In some embodiments, the edible plant is ginger. In some embodiments, effective amount of RNA comprises and effective amount of an miRNA. In some embodiments, the miRNA is selected from the group consisting of miR166c, miRNA167a, miR319a, miR396e, miR842, and miR827. In some embodiments, the gut microbiota that is modulated is a Lactobacillaceae, a Bacteroidaceae, a Clostridiaceae, a Ruminococcaceae, or any combination thereof. In some embodiments, the gut dysbiosis comprises inflammation. In some embodiments, the gut dysbiosis is colitis. In some embodiments, the first edible plant-derived nanoparticle is a ginger exosome-like nanoparticle (ELN) that encapsulates an effective amount of an miRNA. In some embodiments, the ginger ELN is present within a Lactobacillus rhamnosus GG (LGG) bacterium that is administered to the subject. In some embodiments, the LGG bacterium comprising the ginger ELN is administered orally to the subject. In some embodiments, the administering step comprises administering to the subject a dose of 1-1000 mg/kg, optionally a dose of 20-400 mg/kg.
In some embodiments, the presently disclosed subject matter provides methods for personalized medicine. In some embodiments, the methods comprise screening a subject for a suboptimal gut microbiota, wherein the suboptimal gut microbiota comprises a profile of gut bacterial that can be improved, identifying one or more gut bacteria that could provide a health benefit to the subject, and administering to the subject one or more compositions comprising a first edible plant-derived nanoparticle encapsulating an effective amount of RNA, optionally wherein the RNA is obtained from a second edible-plant derived nanoparticle, wherein the effective amount results in a desirable change in the makeup of the subject's gut microbiota relative to that present prior to the administering step.
The presently disclosed subject matter also provides in some embodiments methods for modulating growth of a bacterium in a subject's digestive system. In some embodiments, the methods comprise administering to the subject an exosome-like nanoparticle (ELN) in an amount and by a route sufficient to modulate the growth of the Lactobacillus bacterium in the subject's digestive system. In some embodiments, the ELN is a ginger ELN (GELN) and the administering results in an increase in the number of Lactobacillaceae and/or Bacteroidaceae in the subject's digestive system, a decrease in the number of Clostridiaceae and/or Ruminococcaceae in the subject's digestive system, or both. In some embodiments, the ELN is a grapefruit ELN (GFELN) and the administering results in a decrease in the number of Lactobacillaceae in the subject's digestive system. In some embodiments, the bacterium is a Lactobacillaceae and the ELN comprises an miR396 microRNA.
In some embodiments, the presently disclosed subject matter also provides methods for modulating one or more inflammatory cytokines in the gut of a subject. In some embodiments, the methods comprise administering to the subject an effective amount of an edible plant-derived nanoparticle encapsulating an effective amount of RNA and/or an RNA isolated therefrom, whereby an inflammatory cytokine in the gut of the subject is modulated. In some embodiments, the inflammatory cytokine is selected from the group consisting of tumor necrosis factor α (TNFα), interleukin 1β (IL-1β), interleukin 22 (IL-22), or a combination thereof. In some embodiments, the administering reduces TNFα and/or IL-1β in the gut of the subject. In some embodiments, the administering increases IL-22 expression in the gut of the subject. In some embodiments, the administering protects against and/or reduces inflammation in the gut of the subject.
The presently disclosed subject matter also provides in some embodiments methods for reducing migration of Lactobacillaceae from the gut to gut-associated bloodstream of a subject. In some embodiments, the methods comprise contacting Lactobacillaceae with a plurality of ginger exosome-like nanoparticles (GELNs) and/or RNA derived therefrom under conditions sufficient for the GELNs and/or RNA derived therefrom to be taken up by the Lactobacillaceae; and administering the Lactobacillaceae in an amount sufficient for the Lactobacillaceae to colonize the gut of the subject, whereby migration of the Lactobacillaceae from the gut to the gut-associated bloodstream of the subject is reduced. In some embodiments, the GELNs and/or the RNA derived therefrom comprise an microRNA selected from the group consisting of a miR167a species or a precursor thereof, an miR842 species or a precursor thereof, an miR827 species or a precursor thereof, or any combination thereof. In some embodiments, the miRNA167a microRNA and/or the precursor thereof is present in an amount sufficient to reduce expression of a spaC gene product in the Lactobacillaceae.
In some embodiments of all of the presently disclosed methods, the subject is a mammal, optionally a human.
The presently disclosed subject matter also provides in some embodiments compositions comprising a first edible plant-derived exosome-like nanoparticle (ELN) encapsulating an effective amount of an RNA, the RNA obtained from a second edible-plant derived nanoparticle. In some embodiments, the first edible plant-derived ELN, the second edible 33plant-derived ELN, or both are derived from an edible plant selected from the group consisting of ginger, grapefruit, carrot, garlic, and turmeric. In some embodiments, the edible plant is ginger. In some embodiments, the effective amount of RNA comprises and effective amount of an miRNA. In some embodiments, the miRNA is selected from the group consisting of miR166c, miRNA167a, miR319a, miR396e, miR842, and miR827. In some embodiments, the effective amount of the RNA is sufficient to modulate gut microbiota in a subject when the composition is administered to a subject. In some embodiments, the gut microbiota that is modulated is from a member of Lactobacillaceae, Bacteroidaceae, Clostridiaceae, or Ruminococcaceae.
The presently disclosed subject matter also provides in some embodiments pharmaceutical compositions comprising the compositions as disclosed herein and at least one pharmaceutically acceptable carrier, diluent, and/or excipient. In some embodiments, the pharmaceutical composition is pharmaceutically acceptable for use in a human. In some embodiments, the pharmaceutical composition is formulated for oral administration.
Thus, it is an object of the presently disclosed subject matter to provide compositions and methods for regulating and modifying the gut microbiota.
An object of the presently disclosed subject matter having been stated hereinabove, and which is achieved in whole or in part by the presently disclosed subject matter, other objects will become evident as the description proceeds when taken in connection with the accompanying Figures as best described herein below.
SEQ ID NOs: 1 and 2 are the nucleotide sequences of exemplary oligonucleotides that can be employed for amplifying a SpaC fragment that includes the ginger ELN (GELN) ath-miR167a target sequence.
SEQ ID NOs: 3 and 4 are the nucleotide sequences of exemplary oligonucleotides that can be employed for mutating the GELN ath-miR167a target sequence.
SEQ ID NOs: 5 and 6 are the nucleotide sequences of exemplary oligonucleotides that can be employed for amplifying v1-v3 regions of bacterial 16S rRNA genes.
SEQ ID NOs: 7 and 8 are the nucleotide sequences of exemplary oligonucleotide adaptors that can be employed for anchoring oligonucleotides for multiplexing.
SEQ ID NO: 9 is the nucleotide sequence of the mature ath-miR167a-5p.
SEQ ID NO: 10 is the nucleotide sequence of an exemplary oligonucleotide primer that can be employed along with the QIAGEN Universal Reverse Primer in a quantitative PCR (qPCR) reaction of an osa-miR820a (SEQ ID NO: 141) nucleic acid.
SEQ ID NO: 11 is the nucleotide sequence of an exemplary oligonucleotide primer that can be employed along with the QIAGEN Universal Reverse Primer in a quantitative PCR (qPCR) reaction of an ath-miR167a-5p nucleic acid.
SEQ ID NO: 12 is the nucleotide sequence of an exemplary oligonucleotide primer that can be employed along with the QIAGEN Universal Reverse Primer in a quantitative PCR (qPCR) reaction of an osa-miR820a (SEQ ID NO: 141) nucleic acid.
SEQ ID NO: 13 is the nucleotide sequence of an exemplary oligonucleotide primer that can be employed along with the QIAGEN Universal Reverse Primer in a quantitative PCR (qPCR) reaction of a vvi-miR3634-3p (SEQ ID NO: 159) nucleic acid.
SEQ ID NO: 14 is the nucleotide sequence of an exemplary oligonucleotide primer that can be employed along with the QIAGEN Universal Reverse Primer in a quantitative PCR (qPCR) reaction of an ath-miR842 (SEQ ID NO: 82) nucleic acid.
SEQ ID NO: 15 is the nucleotide sequence of an exemplary oligonucleotide primer that can be employed along with the QIAGEN Universal Reverse Primer in a quantitative PCR (qPCR) reaction of a ppt-miR1028a-3p (SEQ ID NO: 144) nucleic acid.
SEQ ID NO: 16 is the nucleotide sequence of an exemplary oligonucleotide primer that can be employed along with the QIAGEN Universal Reverse Primer in a quantitative PCR (qPCR) reaction of an osa-miR2865 (SEQ ID NO: 137) nucleic acid.
SEQ ID NO: 17 is the nucleotide sequence of an exemplary oligonucleotide primer that can be employed along with the QIAGEN Universal Reverse Primer in a quantitative PCR (qPCR) reaction of an aly-miR163-3p.2 nucleic acid.
SEQ ID NO: 18 is the nucleotide sequence of an exemplary oligonucleotide primer that can be employed along with the QIAGEN Universal Reverse Primer in a quantitative PCR (qPCR) reaction of an osa-miR166j-5p (SEQ ID NO: 136) nucleic acid.
SEQ ID NO: 19 is the nucleotide sequence of an exemplary oligonucleotide primer that can be employed along with the QIAGEN Universal Reverse Primer in a quantitative PCR (qPCR) reaction of an esi-miR3463-5p (SEQ ID NO: 97) nucleic acid.
SEQ ID NO: 20 is the nucleotide sequence of an exemplary oligonucleotide primer that can be employed along with the QIAGEN Universal Reverse Primer in a quantitative PCR (qPCR) reaction of an aly-miR3447-5p (SEQ ID NO: 66) nucleic acid.
SEQ ID NO: 21 is the nucleotide sequence of an exemplary oligonucleotide primer that can be employed along with the QIAGEN Universal Reverse Primer in a quantitative PCR (qPCR) reaction of an esi-miR3469-3p (SEQ ID NO: 98) nucleic acid.
SEQ ID NO: 22 is the nucleotide sequence of an exemplary oligonucleotide primer that can be employed along with the QIAGEN Universal Reverse Primer in a quantitative PCR (qPCR) reaction of a cre-miR1153-5p.2 (SEQ ID NO: 96) nucleic acid.
SEQ ID NO: 23 is the nucleotide sequence of an exemplary oligonucleotide primer that can be employed along with the QIAGEN Universal Reverse Primer in a quantitative PCR (qPCR) reaction of an ath-miR827 (SEQ ID NO: 81) nucleic acid.
SEQ ID NO: 24 is the nucleotide sequence of an exemplary oligonucleotide primer that can be employed along with the QIAGEN Universal Reverse Primer in a quantitative PCR (qPCR) reaction of an mdo-miR-7267-3p (SEQ ID NO: 129) nucleic acid.
SEQ ID NOs: 25 and 26 are the nucleotide sequences of exemplary oligonucleotides primer that can be employed together in a quantitative PCR (qPCR) reaction of a ycnE nucleic acid.
SEQ ID NOs: 27 and 28 are the nucleotide sequences of exemplary oligonucleotides primer that can be employed together in a quantitative PCR (qPCR) reaction of spaC nucleic acid.
SEQ ID NOs: 29 and 30 are the nucleotide sequences of exemplary oligonucleotides primer that can be employed together in a quantitative PCR (qPCR) reaction of lexA nucleic acid.
SEQ ID NOs: 31 and 32 are the nucleotide sequences of exemplary oligonucleotides primer that can be employed together in a quantitative PCR (qPCR) reaction of a Bacteroidetes-specific nucleic acid.
SEQ ID NOs: 33 and 34 are the nucleotide sequences of exemplary oligonucleotides primer that can be employed together in a quantitative PCR (qPCR) reaction of a Clostridial-specific nucleic acid.
SEQ ID NOs: 35 and 36 are the nucleotide sequences of exemplary oligonucleotides primer that can be employed together in a quantitative PCR (qPCR) reaction of a Bacteria-specific nucleic acid.
SEQ ID NOs: 37 and 38 are the nucleotide sequences of exemplary oligonucleotides primer that can be employed together in a quantitative PCR (qPCR) reaction of a Lactobacilli-specific nucleic acid.
SEQ ID NOs: 39 and 40 are the nucleotide sequences of exemplary oligonucleotides primer that can be employed together in a quantitative PCR (qPCR) reaction of a Enterobacteria-specific nucleic acid.
SEQ ID NOs: 41 and 42 are the nucleotide sequences of exemplary oligonucleotides primer that can be employed together in a quantitative PCR (qPCR) reaction of an LGG-dnaJ-specific nucleic acid.
SEQ ID NOs: 43 and 44 are the nucleotide sequences of exemplary oligonucleotides primer that can be employed together in a quantitative PCR (qPCR) reaction of a Ruminococcaceae-specific nucleic acid.
SEQ ID NOs: 45 and 46 are the nucleotide sequences of exemplary oligonucleotides primer that can be employed together in a quantitative PCR (qPCR) reaction of a universal 16S rRNA.
SEQ ID NOs: 47-164 arfe the nucleotide sequences of exemplary mature miRNAs disclosed herein, particularly those disclosed in the Tables.
The details of one or more embodiments of the presently-disclosed subject matter are set forth in this document. Modifications to embodiments described in this document, and other embodiments, will be evident to those of ordinary skill in the art after a study of the information provided in this document. The information provided in this document, and particularly the specific details of the described exemplary embodiments, is provided primarily for clearness of understanding and no unnecessary limitations are to be understood therefrom. In case of conflict, the specification of this document, including definitions, will control.
While the terms used herein are believed to be well understood by those of ordinary skill in the art, certain definitions are set forth to facilitate explanation of the presently-disclosed subject matter.
Unless defined otherwise, all technical and scientific terms used herein have the same meaning as is commonly understood by one of skill in the art to which the invention(s) belong.
Where reference is made to a URL or other such identifier or address, it understood that such identifiers can change and particular information on the internet can come and go, but equivalent information can be found by searching the internet. Reference thereto evidences the availability and public dissemination of such information.
As used herein, the abbreviations for any protective groups, amino acids and other compounds, are, unless indicated otherwise, in accord with their common usage, recognized abbreviations, or the IUPAC—IUB Commission on Bio-Chemical Nomenclature Symbols for Amino-Acid Derivatives and Peptides, 1972.
Although any methods, devices, and materials similar or equivalent to those described herein can be used in the practice or testing of the presently-disclosed subject matter, representative methods, devices, and materials are described herein.
The present application can “comprise” (open ended) or “consist essentially of” the components of the present invention as well as other ingredients or elements described herein. As used herein, “comprising” is open ended and means the elements recited, or their equivalent in structure or function, plus any other element or elements which are not recited. The terms “having” and “including” are also to be construed as open ended unless the context suggests otherwise.
Following long-standing patent law convention, the terms “a”, “an”, and “the” refer to “one or more” when used in this application, including the claims. Thus, for example, reference to “a cell” includes a plurality of such cells, and so forth.
Unless otherwise indicated, all numbers expressing quantities of ingredients, properties such as reaction conditions, and so forth used in the specification and claims are to be understood as being modified in all instances by the term “about”. Accordingly, unless indicated to the contrary, the numerical parameters set forth in this specification and claims are approximations that can vary depending upon the desired properties sought to be obtained by the presently-disclosed subject matter.
As used herein, the term “about,” when referring to a value or to an amount of mass, weight, time, volume, concentration or percentage is meant to encompass variations of in some embodiments ±20%, in some embodiments ±10%, in some embodiments ±5%, in some embodiments ±1%, in some embodiments ±0.5%, and in some embodiments ±0.1% from the specified amount, as such variations are appropriate to perform the disclosed method.
As used herein, ranges can be expressed as from “about” one particular value, and/or to “about” another particular value. It is also understood that there are a number of values disclosed herein, and that each value is also herein disclosed as “about” that particular value in addition to the value itself. For example, if the value “10” is disclosed, then “about 10” is also disclosed. It is also understood that each unit between two particular units are also disclosed. For example, if 10 and 15 are disclosed, then 11, 12, 13, and 14 are also disclosed.
As used herein, “optional” or “optionally” means that the subsequently described event or circumstance does or does not occur and that the description includes instances where said event or circumstance occurs and instances where it does not. For example, an optionally variant portion means that the portion is variant or non-variant.
The presently-disclosed subject matter includes edible plant-derived nanoparticles for regulation of gut microbiota. In some embodiments, a composition is provided that comprises a first edible plant-derived nanoparticle encapsulating an effective amount of RNA. In some embodiments, the RNA encapsulated by the first edible plant-derived nanoparticle is obtained from a second edible-plant derived nanoparticle.
The term “nanoparticle” as used herein in reference to the edible plant-derived nanoparticles of the presently disclosed subject matter, refers to nanoparticles that are in some embodiments in the form of small assemblies of lipid particles, in some embodiments are about 50 to 1000 nm in size, and are not only secreted by many types of in vitro cell cultures and in vivo cells, but are also commonly found in vivo in body fluids, such as blood, urine and malignant ascites. Indeed, such nanoparticles include, but are not limited to, particles such as microvesicles, exosomes, epididimosomes, argosomes, exosome-like vesicles, microparticles, promininosomes, prostasomes, dexosomes, texosomes, dex, tex, archeosomes, and oncosomes.
Such nanoparticles can be formed by a variety of processes, including the release of apoptotic bodies, the budding of microvesicles directly from the cytoplasmic membrane of a cell, and exocytosis from multivesicular bodies. For example, exosomes are commonly formed by their secretion from the endosomal membrane compartments of cells as a consequence of the fusion of multivesicular bodies with the plasma membrane. The multivesicular bodies are formed by inward budding from the endosomal membrane and subsequent pinching off of small vesicles into the luminal space. The internal vesicles present in the multivesicular bodies are then released into the extracellular fluid as so-called exosomes. Nanoparticles can also be engineered to be similar to these isolatable entities.
As part of the formation and release of nanoparticles, unwanted molecules are eliminated from cells. However, cytosolic and plasma membrane proteins are also incorporated during these processes into the microvesicles, resulting in microvesicles having particle size properties, lipid bilayer functional properties, and other unique functional properties that allow the nanoparticles to potentially function as effective nanoparticle carriers of therapeutic agents. In this regard, in some embodiments, the term “nanoparticle” is used interchangeably herein with the terms “microvesicle,” “liposome,” “exosome,” “exosome-like particle,” “nanovector” and grammatical variations of each of the foregoing.
The term “edible plant” is used herein to describe organisms from the kingdom Plantae that are capable of producing their own food, at least in part, from inorganic matter through photosynthesis, and that are fit for consumption by a subject, as defined herein below. Such edible plants include, but are not limited to, vegetables, fruits, nuts, and the like. In some embodiments of the nanoparticle compositions described herein, the edible plant is a fruit. In some embodiments, the fruit is selected from a grape, a grapefruit, and a tomato. In some embodiments, the edible plant is selected from a ginger, a grapefruit, and a carrot. In some embodiments, the edible plant is ginger.
The phrases “derived from an edible plant” and “edible plant-derived”, when used in the context of a nanoparticle, refers to a nanoparticle that, by the hand of man, exists apart from its native environment and is therefore not a product of nature. In this regard, in some embodiments, the phrase “derived from an edible plant” can be used interchangeably with the phrase “isolated from an edible plant” to describe a nanoparticle of the presently-disclosed subject matter that is useful for encapsulating therapeutic agents. However, in some embodiments the phrases “derived from an edible plant” and “edible plant-derived” refer to a nanoparticle that has been created from total lipids extracted from an isolated planbt derived nanoparticle. In such embodiments, the “edible plant-derived nanoparticle” is a nanoparticle that is constructed to have a particular lipid bilayer composition that is substantially similar to that of an edible plant-derived nanoparticle that can be isolated from an edible plant. As discussed in more detail here below, different edible plant-derived nanoparticles preferentially target different types of bacteria based at least in part on the types of lipids present in their bilayers. By way of example and not limitation, exosome-like nanoparticle (ELNs) derived from ginger (GELNs) or from turmeric (TELNs) have lipid bilayers that are enriched for phosphatidic acids (PAs), primarily 1,2-dilinoleoyl-sn-glycero-3-phosphate, C18:1/C18:3 (36:4) and 1-palmitoyl-2-linoleoyl-sn-glycero-3-phosphate, C16:0/C18:2 (34:2). ELNs from grapefruit and garlic have relatively low levels of PAs (only 3.5% and 5.5%, respectively), with the majority of the lipid in grapefruit (GFELNs) and garlic (GaELNs) being phosphatidylcholine (PC; 36.2% and 52.6%, respectively). Manufactured nanoparticles (also referred to herein as “nanovectors” (NVs)) can be designed to have particular lipid bilayer compositions (including but not limited to enriched for PAs or PC) depending on which bacterial genera are of interest to target. By way of example and not limitation, if the bacteria to be targeted are Lactobacillaceae, an nanovector can be designed to have a bilayer enriched in PA since GELNs and garlic NVs (GNVs) have a bilayer enriched in PA and are been shown to preferentially target Lactobacillaceae. Bacterial genera that are preferentially targeted by GFELNs or GaELNs can also be targeted with NVs that comprise a lipid bilayer enriched for PC. Accordingly, the phrase “edible plant-derived nanoparticle” includes both isolatable nanoparticles as well as manufactured nanoparticles.
The phrase “encapsulated by a nanoparticle,” or grammatical variations thereof is used herein to refer to nanoparticles whose lipid bilayer surrounds a therapeutic agent. For example, a reference to “nanoparticle RNA” refers to a nanoparticle whose lipid bilayer encapsulates or surrounds an effective amount of RNA. In some embodiments, the encapsulation of various therapeutic agents within nanoparticles can be achieved by first mixing one or more therapeutic agents with isolated nanoparticles in a suitable buffered solution, such as phosphate-buffered saline (PBS). After a period of incubation sufficient to allow the therapeutic agent to become encapsulated during the incubation period, the nanoparticle/therapeutic agent mixture is then subjected to a sucrose gradient (e.g., an 8, 30, 45, and 60% sucrose gradient) to separate the free therapeutic agent and free microvesicles from the therapeutic agents encapsulated within the microvesicles, and a centrifugation step to isolate the nanoparticles encapsulating the therapeutic agents. After this centrifugation step, the nanoparticles including the therapeutic agents are seen as a band in the sucrose gradient such that they can then be collected, washed, and dissolved in a suitable solution for use as described herein below.
In some embodiments, the effective amount of RNA that is encapsulated by the first edible plant-derived nanoparticle and that is obtained from the second-edible plant derived nanoparticle comprises and effective amount of miRNA. In some embodiments, the miRNA comprises miRNA167a. Of course, microRNAs are naturally occurring, small non-coding RNAs that are about 17 to about 25 nucleotide bases (nt) in length in their biologically active form. miRNAs post-transcriptionally regulate gene expression by repressing target mRNA translation. It is thought that miRNAs function as negative regulators of gene expression and/or of a biological activity of a gene product, i.e. greater amounts of a particular miRNA will correlate with lower levels of target gene expression. There are three forms of miRNAs existing in vivo: primary miRNAs (pri-miRNAs), premature miRNAs (pre-miRNAs), and mature miRNAs. Primary miRNAs (pri-miRNAs) are expressed as stem-loop structured transcripts of about a few hundred bases to over 1 kb. The pri-miRNA transcripts are cleaved in the nucleus by an RNase II endonuclease called Drosha that cleaves both strands of the stem near the base of the stem loop. Drosha cleaves the RNA duplex with staggered cuts, leaving a 5′ phosphate and 2 nt overhang at the 3′ end. The cleavage product, the premature miRNA (pre-miRNA) is about 60 to about 110 nt long with a hairpin structure formed in a fold-back manner. Pre-miRNA is transported from the nucleus to the cytoplasm by Ran-GTP and Exportin-5. Pre-miRNAs are processed further in the cytoplasm by another RNase II endonuclease called Dicer. Dicer recognizes the 5′ phosphate and 3′ overhang, and cleaves the loop off at the stem-loop junction to form miRNA duplexes. The miRNA duplex binds to the RNA-induced silencing complex (RISC), where the antisense strand is preferentially degraded and the sense strand mature miRNA directs RISC to its target site. It is the mature miRNA that is the biologically active form of the miRNA and is about 17 to about 25 nt in length.
In some embodiments of the presently disclosed subject matter, a pharmaceutical composition is provided that comprises an edible plant-derived nanoparticle composition disclosed herein and a pharmaceutical vehicle, carrier, or excipient. In some embodiments, the pharmaceutical composition is pharmaceutically-acceptable for use in humans. Also, as described further below, in some embodiments, the pharmaceutical composition can be formulated as a therapeutic composition for delivery to a subject, including but not limited to a human subject.
A pharmaceutical composition as described herein in some embodiments comprises a composition that includes pharmaceutical carrier such as aqueous and non-aqueous sterile injection solutions that can contain antioxidants, buffers, bacteriostats, bactericidal antibiotics and solutes that render the formulation isotonic with the bodily fluids of the intended recipient; and aqueous and non-aqueous sterile suspensions, which can include suspending agents and thickening agents. The pharmaceutical compositions used can take such forms as suspensions, solutions or emulsions in oily or aqueous vehicles, and can contain formulatory agents such as suspending, stabilizing and/or dispersing agents. Additionally, the formulations can be presented in unit-dose or multi-dose containers, for example sealed ampoules and vials, and can be stored in a frozen or freeze-dried or room temperature (lyophilized) condition requiring only the addition of sterile liquid carrier immediately prior to use.
In some embodiments, solid formulations of the compositions for oral administration can contain suitable carriers or excipients, such as corn starch, gelatin, lactose, acacia, sucrose, microcrystalline cellulose, kaolin, mannitol, dicalcium phosphate, calcium carbonate, sodium chloride, or alginic acid. Disintegrators that can be used include, but are not limited to, microcrystalline cellulose, corn starch, sodium starch glycolate, and alginic acid. Tablet binders that can be used include acacia, methylcellulose, sodium carboxymethylcellulose, polyvinylpyrrolidone, hydroxypropyl methylcellulose, sucrose, starch, and ethylcellulose. Lubricants that can be used include magnesium stearates, stearic acid, silicone fluid, talc, waxes, oils, and colloidal silica. Further, the solid formulations can be uncoated or they can be coated by known techniques to delay disintegration and absorption in the gastrointestinal tract and thereby provide a sustained/extended action over a longer period of time. For example, glyceryl monostearate or glyceryl distearate can be employed to provide a sustained-/extended-release formulation. Numerous techniques for formulating sustained release preparations are known to those of ordinary skill in the art and can be used in accordance with the present invention, including the techniques described in the following references: U.S. Pat. Nos. 4,891,223; 6,004,582; 5,397,574; 5,419,917; 5,458,005; 5,458,887; 5,458,888; 5,472,708; 6,106,862; 6,103,263; 6,099,862; 6,099,859; 6,096,340; 6,077,541; 5,916,595; 5,837,379; 5,834,023; 5,885,616; 5,456,921; 5,603,956; 5,512,297; 5,399,362; 5,399,359; 5,399,358; 5,725,883; 5,773,025; 6,110,498; 5,952,004; 5,912,013; 5,897,876; 5,824,638; 5,464,633; 5,422,123; and 4,839,177; and WO 98/47491, each of which is incorporated herein by this reference.
Liquid preparations for oral administration can take the form of, for example, solutions, syrups or suspensions, or they can be presented as a dry product for constitution with water or other suitable vehicle before use. Such liquid preparations can be prepared by conventional techniques with pharmaceutically-acceptable additives such as suspending agents (e.g., sorbitol syrup, cellulose derivatives or hydrogenated edible fats); emulsifying agents (e.g. lecithin or acacia); non-aqueous vehicles (e.g., almond oil, oily esters, ethyl alcohol or fractionated vegetable oils); and preservatives (e.g., methyl or propyl-p-hydroxybenzoates or sorbic acid). The preparations can also contain buffer salts, flavoring, coloring and sweetening agents as appropriate. Preparations for oral administration can be suitably formulated to give controlled release of the active compound. For buccal administration the compositions can take the form of capsules, tablets or lozenges formulated in conventional manner.
Various liquid and powder formulations can also be prepared by conventional methods for inhalation into the lungs of the subject to be treated or for intranasal administration into the nose and sinus cavities of a subject to be treated. For example, the compositions can be conveniently delivered in the form of an aerosol spray presentation from pressurized packs or a nebulizer, with the use of a suitable propellant, e.g., dichlorodifluoromethane, trichlorofluoromethane, dichlorotetrafluoroethane, carbon dioxide or other suitable gas. Capsules and cartridges of, for example, gelatin for use in an inhaler or insufflator may be formulated containing a powder mix of the desired compound and a suitable powder base such as lactose or starch.
The compositions can also be formulated as a preparation for implantation or injection. Thus, for example, the compositions can be formulated with suitable polymeric or hydrophobic materials (e.g., as an emulsion in an acceptable oil) or ion exchange resins, or as sparingly soluble derivatives (e.g., as a sparingly soluble salt).
Injectable formulations of the compositions can contain various carriers such as vegetable oils, dimethylacetamide, dimethylformamide, ethyl lactate, ethyl carbonate, isopropyl myristate, ethanol, polyols (glycerol, propylene glycol, liquid polyethylene glycol), and the like. For intravenous injections, water soluble versions of the compositions can be administered by the drip method, whereby a formulation including a pharmaceutical composition of the presently-disclosed subject matter and a physiologically-acceptable excipient is infused. Physiologically-acceptable excipients can include, for example, 5% dextrose, 0.9% saline, Ringer's solution or other suitable excipients. Intramuscular preparations, e.g., a sterile formulation of a suitable soluble salt form of the compounds, can be dissolved and administered in a pharmaceutical excipient such as Water-for-Injection, 0.9% saline, or 5% glucose solution. A suitable insoluble form of the composition can be prepared and administered as a suspension in an aqueous base or a pharmaceutically-acceptable oil base, such as an ester of a long chain fatty acid, (e.g., ethyl oleate).
In addition to the formulations described above, the microvesicle compositions of the presently-disclosed subject matter can also be formulated as rectal compositions, such as suppositories or retention enemas, e.g., containing conventional suppository bases such as cocoa butter or other glycerides. Further, the nanoparticle compositions can also be formulated as a depot preparation by combining the compositions with suitable polymeric or hydrophobic materials (for example as an emulsion in an acceptable oil) or ion exchange resins, or as sparingly soluble derivatives, for example, as a sparingly soluble salt.
Further provided, in some embodiments of the presently-disclosed subject matter, are methods for regulating gut microbiota and/or treating gut dysbiosis that comprise administering to a subject an effective amount of a composition comprising a first edible plant-derived nanoparticle encapsulating an effective amount of RNA, where the RNA is obtained from a second edible-plant derived nanoparticle.
As used herein, the terms “treatment” or “treating” relate to any treatment of a condition of interest (e.g., an inflammatory disorder or a cancer), including but not limited to prophylactic treatment and therapeutic treatment. As such, the terms “treatment” or “treating” include, but are not limited to: preventing a condition of interest or the to development of a condition of interest; inhibiting the progression of a condition of interest; arresting or preventing the further development of a condition of interest; reducing the severity of a condition of interest; ameliorating or relieving symptoms associated with a condition of interest; and causing a regression of a condition of interest or one or more of the symptoms associated with a condition of interest.
For administration of a therapeutic composition as disclosed herein (e.g., an edible plant-derived nanoparticle encapsulating a RNA), conventional methods of extrapolating human dosage based on doses administered to a murine animal model can be carried out using the conversion factor for converting the mouse dosage to human dosage: Dose Human per kg=Dose Mouse per kg/12 (Freireich et al., 1966). Doses can also be given in milligrams per square meter of body surface area because this method rather than body weight achieves a good correlation to certain metabolic and excretionary functions. Moreover, body surface area can be used as a common denominator for drug dosage in adults and children as well as in different animal species as described by Freireich et al. 1966. Briefly, to express a mg/kg dose in any given species as the equivalent mg/sq m dose, multiply the dose by the appropriate km factor. In an adult human, 100 mg/kg is equivalent to 100 mg/kg×37 kg/sq m=3700 mg/m2.
Suitable methods for administering a therapeutic composition in accordance with the methods of the presently-disclosed subject matter include, but are not limited to, systemic administration, parenteral administration (including intravascular, intramuscular, and/or intraarterial administration), oral delivery, buccal delivery, rectal delivery, subcutaneous administration, intraperitoneal administration, inhalation, intratracheal installation, surgical implantation, transdermal delivery, local injection, intranasal delivery, and hyper-velocity injection/bombardment. Where applicable, continuous infusion can enhance drug accumulation at a target site (see e.g., U.S. Pat. No. 6,180,082).
Regardless of the route of administration, the compositions of the presently-disclosed subject matter are typically administered in amount effective to achieve the desired response. As such, the term “effective amount” is used herein to refer to an amount of the therapeutic composition (e.g., a nanoparticle encapsulating a therapeutic agent, and a pharmaceutically vehicle, carrier, or excipient) sufficient to produce a measurable biological response (e.g., a decrease in inflammation). Actual dosage levels of active ingredients in a therapeutic composition of the present invention can be varied so as to administer an amount of the active compound(s) that is effective to achieve the desired therapeutic response for a particular subject and/or application. Of course, the effective amount in any particular case will depend upon a variety of factors including the activity of the therapeutic composition, formulation, the route of administration, combination with other drugs or treatments, severity of the condition being treated, and the physical condition and prior medical history of the subject being treated. In some embodiments, a minimal dose is administered, and the dose is escalated in the absence of dose-limiting toxicity to a minimally effective amount. Determination and adjustment of a therapeutically effective dose, as well as evaluation of when and how to make such adjustments, are known to those of ordinary skill in the art.
For additional guidance regarding formulation and dose, see U.S. Pat. Nos. 5,326,902; 5,234,933; PCT International Patent Application Publication No. WO 93/25521; Berkow et al., 1997; Goodman et al., 1996; Ebadi, 1998; Katzung, 2001; Remington et al., 1975; Speight et al., 1997; and Duch et al., 1998.
As used herein, the term “subject” includes both human and animal subjects. Thus, veterinary therapeutic uses are provided in accordance with the presently disclosed subject matter. As such, the presently-disclosed subject matter provides for the treatment of mammals such as humans, as well as those mammals of importance due to being endangered, such as Siberian tigers; of economic importance, such as animals raised on farms for consumption by humans; and/or animals of social importance to humans, such as animals kept as pets or in zoos. Examples of such animals include but are not limited to: carnivores such as cats and dogs; swine, including pigs, hogs, and wild boars; ruminants and/or ungulates such as cattle, oxen, sheep, giraffes, deer, goats, bison, and camels; and horses. Also provided is the treatment of birds, including the treatment of those kinds of birds that are endangered and/or kept in zoos, as well as fowl, and more particularly domesticated fowl, i.e., poultry, such as turkeys, chickens, ducks, geese, guinea fowl, and the like, as they are also of economic importance to humans. Thus, also provided is the treatment of livestock, including, but not limited to, domesticated swine, ruminants, ungulates, horses (including race horses), poultry, and the like.
The practice of the presently-disclosed subject matter can employ, unless otherwise indicated, conventional techniques of cell biology, cell culture, molecular biology, transgenic biology, microbiology, recombinant DNA, and immunology, which are within the skill of the art. Such techniques are explained fully in the literature. See e.g., Sambrook et al., 1989 (Chapters 16 and 17); U.S. Pat. No. 4,683,195; Glover & Hames, 1985; Glover & Hames, 1995; Gait, 1984; Hames & Higgins, eds., 1984; Hames & Higgins, eds., 1985; Freshney, 1987; Immobilized Cells And Enzymes, IRL Press, 1986; Perbal, 1984; Abelson & Simon, 1988a; Abelson & Simon, 1988b; Miller & Calos, 1987; Mayer & Walker, 1987; Weir et al., 1986.
The presently-disclosed subject matter is further illustrated by the following particular but non-limiting examples.
The following EXAMPLES provide illustrative embodiments. In light of the present disclosure and the general level of skill in the art, those of skill will appreciate that the following Examples are intended to be exemplary only and that numerous changes, modifications, and alterations can be employed without departing from the scope of the presently disclosed subject matter.
Herein is shown that edible plant exosome-like nanoparticles, such as ginger ELN, were taken up by gut bacteria, leading to altering the composition of gut bacteria. It is further demonstrated that edible plant RNAs play a role in the ELN mediated change of composition of gut microbiota. Lactobacillus rhamnosus (LGG), a gut bacterium that takes up ginger ELNs (GELNs), was used as a proof-of-concept to study the molecular mechanisms whereby LGG prevents gut inflammation in a mouse colitis model. Lactobacillus colonizes gut mucosal sites using pili (fimbriae) to adhere to intestinal epithelial cells. The pili are formed by the polymerization of 3 subunits, SpaA, B, and C (called SpaCBA). SpaC is a key factor for adhesion between LGG and human intestinal mucus (Segers & Lebeer, 2014). Whether the expression of SpaC is regulated by GELN miRNA is not known. While not wishing to be bound by any particular theory of operation, it is hypothesized that GELNs shape gut microbiota and prevent the invasion of gut microbiota via GELN miRNA interaction with gut bacterial mRNA.
Mice. Eight- to twelve-week-old male specific-pathogen-free (SPF) C57BL/6 mice and IL-22 knockout mice (C57BL/6-IL-22tm1.1(icre)Stck/J) were purchased from the Jackson Laboratory (Bar Harbor, Me., United States of America). AHR knockout mice were purchased from Taconic Biosciences, Inc. (Rensselaer, N.Y., United States of America). All mice were housed under specific-pathogen-free conditions. Germ-free mice were purchased from the National Gnotobiotic Rodent Resource Center (University of North Carolina at Chapel Hill, Chapel Hill, N.C., United States of America) and maintained in flexible film isolators (Taconic Biosciences, Inc.) at the Clean Mouse Facility of the University of Louisville (Louisville, Ky., United States of America). Animal care was performed following the Institute for Laboratory Animal Research (ILAR) guidelines, and all animal experiments were conducted in accordance with protocols approved by the University of Louisville Institutional Animal Care and Use Committee (Louisville, Ky., United States of America).
Clinical Samples. The study involved 58 healthy volunteers between the ages of 25 and 46 years (30 males, 28 females) who were randomly assigned to a GELN group (14 males, 14 females) or a control group (16 males, 14 females) using simple randomization (Kim & Shin, 2014). The sample size for human subjects was determined by a one-way ANOVA-based power analysis (http://www.biostathandbook. com/power.html). Given a power of 0.8, effect size of 0.4 and significance level of 0.05, the sample size needed in each group was 25.52458 (rounded=26) and resource equation method (Festing & Altman, 2002). The participants in the two groups were matched for age and gender. All clinical fecal samples from healthy volunteers were collected in the Department of Surgery, Huai'an First People's Hospital, Huai'an, Jiangsu, China with written informed consent from patients. Approval for the study was granted by the Institutional Research Ethics Committee at the Health Department of Huai'an, Jiangsu, China. All subjects provided signed informed consent for participation in the study. Volunteers were recruited from the population in 2017 in Huai'an, Jiangsu, China. No subjects had a history of chronic gastrointestinal disease, antibiotic use within three months prior to testing, alcohol abuse, or smoking. To prevent bias in study results, participants were kept blinded to the allocation. Both researchers and participants were kept blinded to the treatment groups. Before taking GELNs, volunteers provided fecal samples at day 0. Participants drank GELNs in the amount of 200 mg in 10 ml of sterile 0.9% sodium chloride (GELNs group; n=28) or 10 ml of sterile 0.9% sodium chloride only (control group; n=30) on days 2, 4, and 6. The feces of all enrolled subjects were collected at day 7.
Cells. C57BL/6 murine colon adenocarcinoma MC-38 cells (gender unknown; Kerafast, Inc., Boston, Mass., United States of America) or human epithelial colorectal adenocarcinoma Caco-2 cells (male karyotype; American Type Culture Collection, ATCC®, Manassas, Va., United States of America) were grown in tissue culture plates with Dulbecco's modified Eagle's medium (DMEM) supplemented with 10% heat-inactivated fetal bovine serum (FBS), 100 U/mL penicillin, and 100 μg/mL streptomycin at 37° C. in a 5% CO2 atmosphere.
Bacteria. Lactobacillus rhamnosus (LGG) was obtained from ATCC® (Catalog No. 53103). The SpaC-deleted LGG was cultured in Lysogeny broth (LB; ISC BioExpress, Kaysville, Utah, United States of America) at 37° C. Ruminococcaceae sp. (ATCC® Catalog No. TSD-27) was grown in GS2+cellobiose medium (Biddle et al., 2013). Listeria monocytogenes (Listeria; ATCC® Catalog No. 15313) and Bacteroides fragilis (Fragilis, NCTC 9343) were cultured in brain heart infusion (BHI) broth (Hardy Diagnostics, Santa Maria, Calif., United States of America) as described in Zhang & Wang, 2015 and Deng et al., 2015, respectively. LGG was grown in MRS broth media at 37° C. in anaerobic conditions for 14-16 hours to an OD600 of 0.8-1.0. Bacterial viability and concentration were checked by MRS agar platting. Cultures were centrifuged and the bacterial pellet was diluted in MRS for in vitro experiments and in PBS for gavaging at 109 CFU/mouse per day.
Preparation of Plant ELNs. To prepare plant exosome-like nanoparticles (ELNs), peeled Hawaiian ginger roots (Simply ginger, PLU #:4612), carrot, garlic, turmeric roots, and grapefruit were used for isolation and purification of ELNs using a previously described method (Mu et al., 2014). Briefly, the plants listed above were peeled and then homogenized in a high-speed blender for 1 minute. The juice was collected after net filtration. The supernatant was collected after centrifugation at 1,000×g for 10 minutes, 2,000×g for 20 minutes, 4,000×g for 30 minutes, and 10,000×g for 1 hour. The pellets containing nanoparticles derived from each plant were spun down at 100,000×g for 1.5 hours at 4° C. The isolated exosomes were further purified in a sucrose gradient (8, 30, 45, and 60% sucrose in 20 mM Tri-Cl, pH 7.2), followed by centrifugation at 100,000×g for 1.5 hours at 4° C. Purified GELNs were fixed in 2% paraformaldehyde and imaged under a Zeiss EM 900 electron microscope using a previously described method (Mu et al., 2014). The purity of GELNs was evaluated by calculating the ratio of particle to protein (Webber & Clayton, 2013). The size distribution of GELNs was analyzed using a Zetasizer Nano ZS (Malvern Instrument, United Kingdom) at a flow rate of 0.03 ml per minute. The protein concentration of GELNs was determined using a Bio-Rad Protein Quantitation Assay kit with bovine serum albumin as the standard.
RNA Extraction. Total RNA containing miRNA was isolated from ELNs and murine tissue using a miRNeasy mini kit (QIAGEN) according to the manufacturer's instructions. In brief, 50 mg of plant-derived ELNs or tissue was disrupted in QIAzol Lysis Reagent. Tissue was homogenized using a tissue grinder before disruption. The homogenate was mixed with 140 μl of chloroform and centrifuged. The upper aqueous phase was mixed with 1.5 volumes of ethanol and loaded into an RNeasy spin column. The flow-through was discarded after centrifugation, and the column was washed with RWT and RPE sequentially. Total RNA was eluted with RNase-free water. Bacterial mRNA was isolated using RiboPure Bacteria and MICROBExpress kits (Thermo Fisher Scientific) according to the manufacturers' instructions. The quality and quantity of the isolated RNA were analyzed using a NanoDrop spectrophotometer and Agilent Bioanalyzer.
Preparation of Plant Nanovectors. To prepare GELN nanovectors (GNVs) and grapefruit ELN nanovectors (GFNVs), the GELN or grapefruit ELN-derived lipids were extracted with chloroform and dried under vacuum. To generate GNVs and GFNVs, 200 nmol of lipid was suspended in 200-400 μl of 155 mM NaCl with or without 10 μg of ELN-derived RNA. After UV irradiation at 500 mJ/cm2 in a Spectrolinker crosslinker (Spectronic Corp., Westbury, N.Y., United States of America) and a bath sonication (F S60 bath sonicator; Thermo Fisher Scientific, Hampton, N.H., United States of America) for 30 minutes, the pelleted particles were collected by centrifugation at 100,000×g for 1 hour at 4° C. The RNA encapsulation efficiency of GNVs (68±5%) was determined using a previously described method (Teng et al., 2016).
Plant ELN Distribution in Vivo. Plant ELNs labeled with DiR dye were administered to C57BL/6 mice (n=5) by oral gavage at 500 mg/kg. The labeled plant ELNs in the gut of mice were visualized using an Odyssey CLx Imaging System (LI-COR, Inc., Lincoln, Nebr., United States of America).
Migration Assays. MC-38 or Caco-2 cells (ATCC) were seeded at 1×105 cells per well in a 12-well tissue culture plate with Dulbecco's modified Eagle's medium (DMEM) without antibiotics. The cells were inoculated with 1×107 bacteria per well for 90 minutes at 37° C. in a 5% CO2 atmosphere to allow bacterial adhesion and entry. The number of intracellular bacteria was quantified as described in Zhang & Wang, 1998.
DSS Colitis Model. Colitis was induced by addition of dextran sulfate sodium (DSS; MP Biomedicals, Santa Ana, Calif., United States of America) to autoclaved drinking water at 2.5%. Colitis development was monitored daily by assessing body weight and presence of blood in the stool.
Bacterial Translocation. Bacterial translocation from the murine gut to peripheral blood and liver was determined at the indicated times presented in the relevant figures after oral bacterial administration. Fifty microliters of anticoagulant blood were cultured on MRS agar for 48 h at 37° C. in an anaerobic chamber. Liver tissue samples were homogenized in 0.5% Triton X-100/PBS, and 100 μl of the homogenates were cultured on MRS agar plates. After 48 hours of incubation, CFUs were counted, and the results are expressed as number of bacteria detected/mL of blood or gram of liver.
Labeling of Bacteria and Nanoparticles. Bacteria, ELNs, or ELN nanovectors were labeled with PKH26 or PKH67 Fluorescent Cell Linker Kits (Sigma-Aldrich Co., St. Louis, Mo., United States of America) in accordance with the manufacturer's instructions. After a wash with PBS, bacteria pellets, ELNs or ELN nanovectors were suspended in 250-500 μl of diluent C with 2-4 μl of PKH26/67 and subsequently incubated for 30 minutes at room temperature. After centrifugation for 5 minutes at 13,000×g, labeled LGG, ELNs, or ELN nanovectors were resuspended for further use.
Bacteria GELN Uptake Assay. Briefly, 1×107 LGG cells were incubated for 30 minutes at room temperature with 1 mg of PKH26-labeled GELNs or 1 μg of GELN RNA encapsulated in GNVs. After two washes with PBS, LGG uptake of GELNs was visualized using a confocal microscope. To exclude the possibility of detecting GELNs remaining (adhering) on the outside of bacteria, the bacteria were washed three times with medium and treated with 100 μl of 0.5% Triton X-100 for eight minutes, followed by the immediate addition of bacteria broth to wash bacteria twice before the bacteria were imaged using confocal microscopy. (Note: 0.5% Triton X-100 did not affect bacterial viability for at least 30 minutes after addition).
Immunogold Labeling of LGG Pili and TEM. To visualize LGG pili via transmission electron microscopy (TEM), LGG cultures were grown overnight (OD600<1.0) and washed once with PBS. Formvar-carbon-coated copper grids (Electron Microscopy Sciences, Hatfield, Pa., United States of America) first were floated for 1 hour on droplets of the diluted LGG at 107/mL in PBS, washed several times with 0.02 M glycine in PBS, and then treated with a blocking solution of 1% bovine serum albumin (BSA) in PBS. The grids were then floated for 1 hour on droplets of anti-SpaC serum (1:100) in blocking solution. After a wash with 0.1% BSA in PBS, the grids were incubated for 20 minutes with protein A-conjugated 10-nm-diameter gold particles (Cytodiagnostics, Burlington, Ontario, Canada) diluted 1:55 in blocking solution. After one wash in PBS, the grids were fixed with 1% glutaraldehyde, washed with distilled water, and then stained with 1% ammonium molybdate on the surface of the EM grid. After excess ammonium molybdate was removed from the grid, images were visualized using a Thermo-Fisher TEM Tecnai Spirit at 80 kV, and images were collected with an AMT XR60 digital camera.
Quantitative Real-Time PCR for RNA Expression. The quantity of mature miRNAs was determined with quantitative real-time PCR (qPCR) using a miScript II RT kit (QIAGEN Inc., Germantown, Md., United States of America) and miScript SYBR Green PCR Kit (QIAGEN) with QIAGEN 3′ universal primers. The 5′ specific miRNA primers used are listed in Table 1. For analysis of gene mRNA expression, 1 μg of total RNA was reverse transcribed using SuperScript III reverse transcriptase (Invitrogen, Waltham, Mass., United States of America), and quantitation was performed using SsoAdvanced™ Universal SYBR Green Supermix (Bio-Rad Laboratories, Inc., Hercules, Calif., United States of America) and the listed primers (Table 1) with SsoAdvanced™ Universal SYBR Green Supermix (Bio-Rad). qPCR was performed using a Bio-Rad CFX96 qPCR System with each reaction run in triplicate. Analysis and fold-changes were determined using the comparative threshold cycle (Ct) method. Changes in miRNA or mRNA expression were calculated as fold-change.
Quantification of Gut Bacteria Using QPCR. For gut bacteria identification, qPCR was performed from gut microbiota-derived DNA extracted with a QIAamp DNA Stool Mini Kit (QIAGEN). All kits were used according to the manufacturer's instructions. Quantitation was performed using SsoAdvanced™ Universal SYBR Green Supermix (Bio-Rad), and the bacterial specific primers are listed in Table 1. qPCR was performed using the Bio-Rad CFX96 qPCR System with each reaction run in triplicate. Analysis and fold-change were determined using the comparative threshold cycle (Ct) method.
Plasmid Construction and Mutagenesis. The SpaC fragment (339-800, LGG RS02140) spanning the sequences of the potential target (710-717) of GELN ath-miR167a was obtained by PCR with cDNA from LGG RNA. PCR was performed using a Bio-Rad thermal cycler T100. The 462-bp PCR product amplified by the primer pair SpaC-pGFPuv-F: 5′-GCGCATGCCTGCAACTAATTTTGTCGCAAACG-3′ (SEQ ID NO: 1) and SpaC-pGFPuv-R: 5′-CCTCTAGAACAGTTTTCAGCAGGCATCC-3′ (SEQ ID NO: 2) was ligated into the Sphl and Xbal restriction enzyme sites of a pGFPuv vector (Takara Bio/Clontech, Mountain View, Calif., United States of America) to obtain a green fluorescent protein (GFP) expression reporter. SpaC-pGFPuv fused with the SpaC gene fragment, which can be expressed in prokaryotic cells. To generate mutants of SpaC, the oligonucleotide primers SpaCMut-F, 5′-CTGTAGGTGCTGTAACTGCCTGAATA CCGTAATAC-3′ (SEQ ID NO: 3), and SpaCMut-R, 5′-GTATTACGGTATTCAGGCAG TTACAGCACCTACAG-3′ (SEQ ID NO: 4), were designed to specifically disrupt the putative ath-miR167a binding site. A GENEART® brand Site-Directed Mutagenesis System (#A13282, Invitrogen) was used in conjunction with specific primers to introduce a SpaC mutation in the pGFPuv construct according to the manufacturer's instructions. After mutant strand synthesis (using T4 DNA polymerase) and ligation, the resultant plasmids were introduced into E. coli, and transformants were selected using ampicillin resistance. Further restriction endonuclease Sphl and Xbal analysis was performed to screen clones, and all of the constructs were confirmed by DNA sequencing.
Microbiota 16S rRNA Gene Sequencing. GELNs were administered by gavage to C57BL/6 mice (500 mg/kg of body weight) three times in seven days (n=5). To identify bacterial strains that preferentially take up GELNs, PKH26-labeled GELNs were administered by gavage, and PKH26-positive microbiota from fecal samples were sorted using a BD FACSARIA™ III brand cell sorter (BD Biosciences, San Jose, Calif., United States of America). Bacterial DNA from fecal samples was isolated with QIAamp DNA Stool Mini Kits (QIAGEN), and bacterial strains were investigated using 16S rRNA gene sequencing. DNA (15 ng) was used as a template to amplify the 16S rRNA gene using a High Fidelity PCR system kit (Roche Molecular Systems, Inc., Branchburg, N.J., United States of America). The v1-v3 regions of 16S ribosomal RNA gene were amplified using 27f (5′-AGAGTTTGATCCTGGCTCAG-3′; SEQ ID NO: 5) and 534r (5′-ATTACCGCGGCTGCTGG-3′; SEQ ID NO: 6) primers (1 μM). The primers were anchored with adaptors (adapter A: 5′-CCATCTCATCCCTGCGTGTCTCCGACTCAG-3′; SEQ ID NO: 7 and adapter B: 5′-CCTATCCCCTGTGTGCCTTGGCAGTCTCAG-3′; SEQ ID NO: 8) and Multiplex Identifiers (MIDs; 10 bp long). The multiplexed amplicons were purified using a QIAquick Gel Extraction Kit (QIAGEN). The amplicon sequence was conducted using the 454 Jr. Sequencing platform. The 16S rRNA gene sequences were analyzed using QIIME platform scripts (www.qiime.org). The microbial classification was performed with the GreenGenes reference database (Version gg_otus-13_8; The Greengenes Database Consortium, Second Genome, Inc., University of Colorado, Boulder, Colo., United States of America, University of Queensland, Brisbane, Australia) using QIIME tools (Caporaso et al., 2010a). By applying hierarchical clustering algorithms (HCAs), the species clustering based on the operational taxonomic unit (OTU) using amplicon sequencing of 16S RNA was determined. The reference sequences allowed sorting of the results into OTUs by clustering 97% sequence similarity (uclust) and classification according to various taxonomic ranks (phylum, order, class, family, genus, and species). The percentage of each bacterial species was virtualized with Interactive Tree Of Life (iTOL) and R software (Letunic & Bork, 2007).
Mouse Cytokine Array. To investigate effects of GELN RNAs on the regulation of cytokine expression in colon epithelia, germ-free mice with DSS-induced colitis were administered 109 LGG pretreated with GNVs or GNVs with GELN RNAs. The colon tissue extracts were prepared in modified radioimmunoprecipitation assay (RIPA) buffer (Sigma) with the addition of protease and phosphatase inhibitors (Roche). Cytokine proteins were analyzed with a Proteome Profiler Mouse XL Cytokine Array Kit (Catalog No. ARY028; R&D Systems, Inc., Minneapolis, Minn., United States of America). Quantification of the spot intensity in the arrays was conducted with background subtraction using ImageJ.
Proteomic LGG Sample Preparation. Briefly, 1×107 LGG were incubated with 1 mg GELNs for 2 hours and then harvested by centrifugation at 13,000×g for 5 minutes. Bacteria were suspended in lysis buffer (2% SDS, 100 mM DTT, 20 mM Tris-HCl pH 8.8) for 20 minutes at 95° C. LGG lysate was collected from supernatants after centrifugation, and concentrations were estimated using an RC DC Protein Assay Kit (Bio-Rad). Protein aliquots (50 μg) were diluted into 4% SDS/0.1 M Tris-HCl pH 8.5 and 1 M DTT and processed according to the filter-aided sample preparation (FASP) method as described in Teng et al., 2017. The digested, ultrafiltered samples were trap-cleaned with C18 PROTO™, 300 Å Ultra MicroSpin columns; lyophilized by vacuum centrifugation; and redissolved in 16 μl of 2% v/v acetonitrile. Concentrations were estimated based on absorption at 205 nm using a NanoDrop 2000 spectrophotometer (Thermo Fisher Scientific, San Jose, Calif., United States of America).
LC-MS Analysis of LGG Protein. Liquid chromatography-mass spectrometry (LC-MS) was carried out using a method described in Teng et al., 2017. Proteome Discoverer v1.4.1.114 (Thermo) was used to analyze the data collected by MS. The database used in Mascot v2.5.1 and SequestHT searches was the Feb. 17, 2017 version of the LGG proteome from UniprotKB (Proteome ID UP000000955; https://www.uniprot.org). Scaffold was used to calculate the false discovery rate using the Peptide and Protein Prophet algorithms. Proteins were grouped to satisfy the parsimony principle. The proteins were clustered based on differential expression, and heat maps representing differentially regulated proteins by GELNs were generated using R software.
Coomassie Blue Staining. The LGG proteins were separated on a 10% SDS-PAGE gel. The gel was fixed and stained for imaging using 0.1% Coomassie Brilliant Blue R-250 (Bio-Rad).
Western Blotting. LGG cells were treated as indicated in each individual Figure and harvested from 100-350 ml cultures by centrifugation at 5,000×g for 10 minutes. The cells were resuspended on ice for 45 minutes in 1 ml of TE buffer (100 mM Tris-Cl, 10 mM EDTA, pH 8.0) supplemented with protease inhibitor cocktail (Roche) and lysozyme (1 mg/mL). The cell lysates were sonicated on ice using three 10-second bursts at medium intensity and then frozen in liquid nitrogen. The lysates were quickly thawed at 37° C., and two more rapid sonication-freeze-thaw cycles were performed. Proteins were separated on 10% SDS-PAGE gels and transferred to PVDF membranes (Bio-Rad Laboratories, Inc., Hercules, Calif.). Mouse anti-SpaC antibody was purchased from PodiCeps (Catalog No. PODI-0063, Netherland) and anti-DnaK antibody was purchased from Abcam (Catalog No. ab69617; Cambridge, Mass., United States of America). After the Alexa Fluor-647 (Invitrogen) conjugated secondary antibody incubation, the bands were visualized and analyzed using an Odyssey Imager (LI-COR, Lincoln, Nebr., United States of America). For immunoblotting of tissue, mice were treated as indicated in the figure legends, and lysates were prepared in modified RIPA buffer (Sigma) with the addition of protease and phosphatase inhibitors (Roche). Proteins were separated on 10% SDS-PAGE gels and transferred to PVDF membranes (Bio-Rad Laboratories, Inc.). Dual-color precision protein MW markers (Bio-Rad) were separated in parallel. Antibodies were purchased as follows: AHR (PAS-25447) and phosphorylated AHR (PAS-38404) antibodies from Thermo Fisher, CYP1A1 (ab79819) and GAPDH (ab9485) antibodies from Abcam. The secondary antibodies conjugated to Alex Fluor-488 or Alex Fluor-594 were purchased from Invitrogen (Eugene, Oreg., United States of America). The bands were visualized using an Odyssey Imager (LI-COR).
GELN RNA Libraries and Sequencing. Small RNA libraries were generated with 100 ng of total RNA and TruSeq Small RNA Library Preparation Kits (Illumina, Inc., San Diego, Calif., United States of America) according to the manufacturer's instructions. Following PCR amplification (16 cycles), libraries between 140 and 160 bp in size were gel purified and resuspended in 11 μl of ultrapure water. Equal amounts of libraries were pooled and sequenced on the Illumina HiSeq 2500, followed by demultiplexing and fastq generation with CASAVA v1.8.4. Raw fastqs were adapter and quality score trimmed with cutadapt v1.10. with a minimum length of 15 nt. MicroRNAs were identified using sRNABench Pipeline software (version 05/14). A core set of plant miRNAs from miRBase v21 were used as the reference, and this set included all 14 plant species with at least 200 mature microRNA sequences annotated in miRBase. Within the sRNABench pipeline, mapping was performed with bowtie software (v0.12.9), and microRNA folding was predicted with RNAfold from the Vienna package (v2.1.6).
LGG mRNA Sequencing. LGG cells were treated with fluorescent dye PKH26-labeled GELNs or PBS as indicated in the individual figure legends and harvested from 100-350 ml cultures by centrifugation at 4000×g for 10 minutes. PKH26-positive LGG were sorted with FACS. mRNA was isolated from bacteria using RiboPure Bacteria and MICROBExpress (Thermo Fisher Scientific). For each RNA sample, double-stranded cDNA was synthesized from 10 ng mRNA using a SMARTer Universal Low Input RNA Kit (Catalog No. 634940; Takara Bio Inc., Mountain View, Calif., United States of America) for sequencing, which included a 16-cycle PCR. Following quantitation with Qubit dsDNA HS Reagent (Catalog No., Q32854; Thermo Scientific,), 10 ng of dscDNA/sample was fragmented with an E220 Focused-ultrasonicator (Covaris, Matthews, N.C., United States of America). The fragmented cDNA was then prepared into libraries using a KAPA Hyper Prep Kit (Catalog NO. KK8504; KAPA Biosystems, Wilmington, Massacusetts, United States of America). Libraries were then combined into equimolar pools, which were then measured for size and concentration. The pools were clustered onto a paired-end flowcell with a 20% v/v PhiX spike-in and sequenced on an Illumina HighSeq 2500 sequencer. The first and second reads were each 83 bases.
Species Alignment and Analysis. The mRNA sequencing data were demultiplexed and converted to fastqs with CASAVA v1.8.4, and 7 nt were trimmed from R1 and R2 raw fastqs with cutadapt v1.10 as recommended by the SMARTer kit. Transcript abundance was estimated with salmon v7.2 with the following options: -libType A -num, Bootstraps 100, -seqBias -gcBias -dumpEq -geneMap. For LGG abundance, the transcriptome fasta and annotation from EnsemblBacteria (Genome Assembly ASM2650v1) were used. For Zingiber officinale (ginger) abundance, the ESTs from NCBI were used as transcriptome input for salmon. Ginger transcript sequence similarity was determined using NCBI blast v.2.2.26, keeping the top hit against the nucleotide (nt) database with a maximum e-value of 0.001.
Predicting GELN miRNA Targeting to LGG mRNA. After downloading eleven gut bacterial genomes from the RefSeq database available from the website of the National Center for Biotecnology Information (NCBI; U.S. National Library of Medicine, Bethesda Md., United States of America), bacterial mRNAs potentially targeted by ginger miRNAs were identified by enrichment analysis of the reverse complement of the miRNA seed sequence in the 300 bp region near the coding sequence (CDS) start site (200 bp before and 100 bp after the site). For the enrichment analysis, two seed subsequences were used: a 7-mer (nt 2-8) and an 8-mer (nt 1-8). The enrichment analysis adopted a framework that utilizes the 1st order Markov model (MM). In this framework, the observed k-mer count in the 300-bp region of each bacterial mRNA was compared against the background count derived from the 1′ order Markov model. A P-value was then calculated for each miRNA-mRNA pair to estimate the likelihood of having a functional pair. Once all p-values were calculated, the false discovery rate (FDR) was obtained using the Benjamini-Hochberg method (Benjamini & Hochberg, 1995) for multiple P-value correction.
Microbial DNA QPCR Arrays. To determine whether ELN RNA has an effect on the composition of major gut microbial species, mice were gavaged with GELN RNAs and grapefruit and carrot ELN RNAs encapsulated in the GELN lipid-derived liposomes (GNVs; 500 mg/kg mouse weight in 100 μl PBS; n=5). The GNVs were given to mice once every other day for seven days. Three hours after the last dose, the mice were sacrificed, fecal DNA was extracted, and a qPCR array was performed using QIAGEN Custom Microbial DNA qPCR Arrays (Catalog No. 330161) on an Applied Biosystems VIIA™ 7 Real-Time PCR System. Normalization to Pan Bacteria (QIAGEN Catalog No. BPCL00362A) was performed using a threshold cycle (Ct) to correct for potential DNA input or RT efficiency biases. DNA qPCR array data generated from the fecal samples were analyzed using SPSS 16.0 software and are based on fold-changes compared with PBS as a control. Heat maps generated from qPCR data using software R reflect the abundance of the microbial species analyzed.
Thin-Layer Chromatography (TLC) Analysis. Lipids from ELNs were extracted and quantitatively analyzed using a method previously described (Wang et al., 2013). TLC was performed (Zhuang et al., 2015). Briefly, HPTLC-plates (silica gel 60 with a concentrating zone, 20 cm×10 cm; Merck KGaA, Darmstadt, Germany) were used for the separation. After aliquots of concentrated lipid samples were extracted from plant ELNs, they were separated on a plate that had been developed with chloroform/methanol/acetic acid (190:9:1, by vol). After drying in air, the plates were sprayed with a 10% copper sulfate and 8% phosphoric acid solution and then charred by heating at 180° C. for 5 min. The bands of lipid on the plate were imaged using an Odyssey Scanner (LI-COR).
Lipidomic Analysis with Mass Spectrometry. Lipid samples extracted from ELNs were submitted to the Lipidomics Research Center, Kansas State University (Manhattan, Kans., United States of America) for analysis using a method previously described. In brief, the lipid composition was determined using triple quadrupole MS (Applied Biosystems Q-TRAP, Applied Biosystems, Foster City, Calif., United States of America). The protocol follows was as described in Wang et al., 2013. The data are reported as the concentration (nmol/mg ELNs) and percentage of each lipid within the total signal for the molecular species determined after normalization of the signals to internal standards of the same lipid class.
Histological Analysis. For hematoxylin and eosin (H&E) staining, tissues were fixed with buffered 10% formalin solution (SF93-20; Fisher Scientific, Fair Lawn, N.J., United States of America) overnight at 4° C. Dehydration was achieved by sequential immersion in a graded ethanol series of 70%, 80%, 95%, and 100% ethanol for 40 minutes each. Tissues were embedded in paraffin and subsequently cut into ultrathin slices (5 μm) using a microtome. Tissue sections were deparaffinized in xylene (Fisher), rehydrated in decreasing concentrations of ethanol in PBS, and stained with H&E, and the slides were scanned with an Aperio ScanScope. For frozen sections, tissues were fixed with periodate-lysine-paraformaldehyde (PLP) and dehydrated with 30% sucrose in PBS overnight at 4° C., and nuclei were stained with 4′,6-diamidino-2-phenylindole dihydrochloride (DAPI). The slides were scanned using an Aperio ScanScope or visualized via confocal laser scanning microscopy (Nikon, Melville, N.Y., United States of America) as described in Teng et al., 2017.
HPLC Analysis of Tryptophan Metabolites. The fecal samples and LGG MRS broth were diluted with an equal volume of methanol. After centrifugation at 10,000×g for 30 minutes, 50 μl of supernatant was injected for high-performance liquid chromatography (HPLC) analysis. The HPLC analysis was performed on an Agilent 1260 Infinity system equipped with an Agilent ZORBAX SB-C18 column (4.6×150 mm, 3.5 μm), with following parameters: mobile phase A: 5 mM NH4Ac in water modified with 0.1% formic acid (v/v); mobile phase B: 5 mM NH4Ac in 90% acetonitrile modified with 0.1% formic acid (v/v); gradient: 5% B in first 5 min, 5-20% B for 10 min, hold 20% B for 5 min, 20%-50% B for 5 min, hold 50% B for 5 min, 50%-100% B for 5 min, hold 100% B for 10 min, 100-5% B for 5 min; flow rate: 1.0 ml/min; temperature: 30° C. UV detection at 300 nm was used to monitor indole-3-carboxaldehyde (I3A) and indole-3-acetaldehyde (IAAld); FLD (ex=280 nm; em=350 nm) was used for detection of tryptophan and indole-3-acetamide (I3AM). The standard for I3A (Catalog No. 129445-5g), I3AM (Catalog No. 286281-1G), IAAld (Catalog No. I1000-25MG), and tryptophan (Catalog No. T0254-25g) were purchased from Sigma.
Enzyme-Linked Immunosorbent Assay (ELISA). The cytokine IL-22, IL-1β, and TNFα levels in cell culture supernatants or mouse colon mucus were quantified using ELISA kits (eBioscience) according to the manufacturer's instructions. Briefly, a microtiter plate was coated with anti-mouse IL-22, IL-1β and TNFα antibody at 1:200 overnight at 4° C. Excess binding sites were blocked with 200 μl of 1×ELISA/ELISPoT Diluent (eBioscience, San Diego, Calif., United States of America) for 1 hour at 22° C. After washing three times with PBS containing 0.05% Tween 20, the plate was incubated with detection antibody in blocking buffer for 1 hour at 22° C. After three washes, avidin conjugated with horseradish peroxidase and substrate were each added sequentially for 1 hour and 30 min at 22° C. An analysis of absorbance at 405 nm using a microtiter plate reader (BioTek Synergy HT, BioTek Instruments, Inc., Winooski, Vt., United States of America) followed.
Isolation of Lymphoid Cells in the Colon. Intestinal lymphoid cells were isolated from the intestine by incubation in PBS supplemented with 1 mM EDTA, 15 mM HEPES and 10% FCS for 30 minutes at 37° C. Supernatants were discarded, and tissues were then incubated in RPMI supplemented with 15 mM HEPES and 300 units/mL collagenase type VIII (Sigma) for 30 minutes with gentle shaking. Lysates were gently pressed through nylon cell strainers (70 μm in diameter; Fisher Scientific), and mononuclear cells were isolated on a 40%/80% colloidal silica particle (Percoll) gradient. Lymphocytes were recovered from the interface and washed twice.
Antibiotic Treatment. Six- to eight-week-old male mice were provided sterile drinking water supplemented with vancomycin (0.5 mg/mL), streptomycin (1 mg/mL), neomycin (1 mg/mL), chloramphenicol (0.5 mg/mL) or metronidazole (1 mg/mL) for 3 weeks before the beginning of GELN or GNV treatment.
Flow Cytometry. Isolated lymphocytes from colon tissue were seeded into 6-well plates and stimulated for 6 hours with LPS (10 μg/mL) in the presence of brefeldin A (5 μg/mL; Invitrogen). Washed cells were stained for 40 minutes at 4° C. with the appropriate fluorochrome-conjugated antibodies in PBS with 2% FBS. Characterization and phenotyping of the various lymphocyte subsets from the liver or spleen were performed using flow cytometry. Data were acquired using a BD FACSCalibur flow cytometer (BD Biosciences, San Jose, Calif., United States of America) and analyzed using FlowJo software (Tree Star Inc., Ashland, Oreg., United States of America). To visualize bacteria stained with PKH26/67 and transformed with SpaC-pGFPuv plasmid, the PKH26/67-positive and GFP-positive bacteria were detected by flow cytometry using a BD FACSCalibur flow cytometer (BD Biosciences, San Jose, Calif., United States of America), and data were analyzed using FlowJo software (Tree Star Inc., Ashland, Oreg., United States of America).
In Vivo Intestinal Permeability Assay. For in vivo intestinal permeability studies, fluorescein-5-isothiocyanate (FITC)-conjugated dextran (MW 4000; Sigma-Aldrich, St. Louis, Mo., United States of America) was administered by oral gavage at a concentration of 60 mg/100 g of body weight. Serum was collected retro-orbitally five hours later, and fluorescence intensity was determined with a fluorescence spectrophotometer (BioTek) at emission and excitation wavelengths of 485 nm and 528 nm, respectively. FITC concentration was measured from standard curves generated by serial dilution of FITC-dextran.
Quantification and Statistical Analysis. Unless otherwise indicated, all statistical analyses in this study were performed with SPSS 16.0 software. The data are presented as values with standard deviation (as the mean±SD). The significance of differences in mean values between two groups was analyzed using Student's t-test. Differences between individual groups were analyzed via one- or two-way ANOVA. Differences between percentages of bacterial composition were analyzed with a chi-square test. Differences were considered significant when the P-value was less than 0.05 or 0.01. A P value greater than 0.05 was considered not significant (NS). Both animals and human subjects were randomly assigned to a control group and different experimental condition groups matched for age and gender using simple randomization. Double-blinded studies were used for animal and human subject studies. Unless otherwise indicated, the mice used in the in vivo study were male C57BL/6 strain mice. Using one-way ANOVA comparing up to four groups, for a power of 0.7, a large effect size (0.75) and a significance level of 0.05, the minimum sample size needed in each group was 4.992 (rounded=5; Festing & Altman, 2002). The reported “n” in animal and human studies represents the number of animals and human subjects. Data are representative of three independent experiments.
A number of edible nanoparticles have been characterized based on electron microscopy (EM) examination (Mu et al., 2014). GELNs were characterized based on size distribution (Mu et al., 2014) and the RNAs and proteins present. Gel electrophoresis demonstrated the presence of substantial amounts of small-sized RNAs (less than 300 nucleotides;
ELN RNA stability in the gut is required for potential interaction of ELN RNA with gut bacterial mRNA. Analysis of the tissue distribution of ELNs indicated that grapefruit ELNs preferentially migrated to the liver, but GELNs were more likely to stay in the intestine. The evidence of GELNs in the gut and feces over a 6-hour period was further confirmed by quantitative PCR (qPCR) analysis of GELN miRNA aly-miR319a-3p and grapefruit miRNA vvi-miR166c (
Whether GELNs cross-talked with gut microbiota and regulated their composition was thus tested. Fecal samples from C57BL/6 mice that were administered GELNs for a week were collected and the microbial composition was analyzed via 16S rRNA gene (v1-v3 regions) sequencing (the sequencing data were deposited in NCBI Sequence Read Archive (SRA); Accession Number SRP121341). Further downstream analysis was performed using QIIME 1.9.1 pipeline tools (Caporaso et al., 2010). Microbial alignment and classification was performed using the Green Genes reference database (Version gg_13_8_otus) as described herein above. An increase in Lactobacillaceae and Bacteroidales S24-7 and a decrease in Clostridiaceae was observed in GELN-treated mice in comparison with mice treated with PBS. The Lactobacillaceae percentage increased from 0.25±0.15% to 24.80±5.41% (p<0.001) in mice that received GELNs by gavage. The sequencing data were subsequently verified using a qPCR assay (
The effect of GELNs at a high dose of 10 mg/25 g of body weight and at a low dose of 0.5 mg/25 g of body weight (a physiologically relevant dose for human intake; Schwertner et al., 2006) on the composition of gut bacteria was determined. The results generated from both higher and lower doses of GELNs supported the conclusion that GELN treatment increases Lactobacillaceae and Bacteroidaceae and decreases Clostridiaceae compared with PBS (
To address whether ELN RNAs influenced gut microbiota composition, ELN RNAs from ginger, grapefruit, and carrot were extracted from purified ELNs and encapsulated in GELN nanovectors (GNVs) made with GELN-derived lipid. The results indicated that the mice gavaged with ginger, grapefruit, or carrot ELN RNAs exhibited a change in the composition of gut microbiota, which suggested that edible plant ELN RNAs had an effect on the gut microbiota composition in general. The data from a heat map depicting the mouse gut microbiota using a qPCR array also supported the finding that GELNs shaped gut microbiota. Ginger ELN RNAs induced several species of Lactobacillus identical to GELNs when compared with GNVs as a control. However, carrot ELN RNAs seem to have no effect on the Lactobacillus level. Cluster analysis using R software (Rosselli et al., 2016) indicated that PBS and GNVs were grouped in the same cluster, GNVs/grapefruit ELN RNAs and GNVs/carrot ELN RNAs were in the same cluster, and GNVs/GELN-RNAs had the least similarity with the other two clusters.
To further determine whether the findings described above can be translated into clinical application, 16S rRNA gene sequencing data generated from stool samples of healthy subjects after oral GELN administration for a week were quantitatively analyzed (
Considering the direct contact of food ELNs and numerous bacteria in the gut, it was hypothesized that food ELNs might be taken up by bacteria and the contents of food ELN RNAs could directly regulate gene expression in bacteria. To test this hypothesis, PKH26-labeled GELNs were administered to C57BL/6 mice via oral gavage. Confocal imaging analysis indicated that the GELNs were taken up by gut bacteria, and this result was further confirmed by quantitative fluorescence-activated cell sorting (FACS) analysis of PKH26+ GELNs. To determine whether the changes in gut bacteria composition were associated with preferential uptake of GELNs by specific gut microbiota, PKH26+ GELNs were administered to mice via oral gavage. The PKH26+ bacteria from fecal samples of mice were sorted by FACS followed by 16S rRNA gene sequencing. The results showed that 31.54 (±7.92%) of the GELNs/PKH26-positive gut bacteria were Lactobacillaceae (
Next, whether the concept that edible plant exosomes could preferentially target bacteria in the intestine could be generalized was tested. ELNs from turmeric, which belongs to the same family as ginger, garlic, and grapefruit, were used as proof of concept. A 16S ribosomal rRNA gene library was generated, and 16S sequencing analysis of fecal samples from mice administered PKH26+ ELNs from garlic, turmeric, and grapefruit was performed (Table 5). The analysis of GELN+ bacteria suggested that all three types of ELNs were preferentially taken up by Bacteroidales S24-7. Interestingly, turmeric, from the same Zingiberaceae family as ginger, was also preferentially taken up by Lactobacillaceae. In contrast, garlic- and grapefruit-derived ELNs were preferentially taken up by Ruminococcaceae.
The data presented herein showed that Lactobacillaceae numbers increased in GELN-administered mice (see
To determine whether GELNs also have an effect on the growth of other Lactobacillus species and other families of bacteria, the growth of Lactobacillus reuteri (L. reuteri), Lactobacillus murinus (L. murinus), B. fragilis, E. coli, and Ruminococcaceae sp. (TSD-27) was evaluated after incubation with GELNs for 8 hours. It was observed that GELNs also induced L. reuteri and L. murinus growth (
To explore the mechanism by which ELNs are preferentially taken up by specific bacteria, comparative lipid profiles generated from mass spectrometry (MS) analysis were assessed (Table 6). It was determined that GELN and turmeric ELN-derived lipids were enriched with phosphatidic acids (PAs; 35.2% and 34.4%, respectively), primarily 1,2-dilinoleoyl-sn-glycero-3-phosphate, C18:1/C18:3 (36:4) and 1-palmitoyl-2-linoleoyl-sn-glycero-3-phosphate, C16:0/C18:2 (34:2), whereas PAs in grapefruit and garlic represented only 3.5% and 5.5%, respectively, of the total lipid content (
It was hypothesized that GELN PA lipids might serve as a signal for preferential uptake by LGG. To generate PA-depleted GELN lipids, GELN lipids were isolated with chloroform and separated via thin-layer chromatography (TLC;
These data suggested that PA is required for GELN uptake by LGG. ELN lipid-dependent uptake was also demonstrated in grapefruit ELNs. FACS analysis indicated that PC-enriched grapefruit GFNVs were preferentially taken up by Ruminococcaceae sp. (TSD-27). PC depletion in grapefruit GFNVs resulted in reduced uptake by Ruminococcaceae, and the uptake was rescued by addition of PC 34:2 back into the PC-depleted grapefruit GNVs (
To further determine whether lipids also play a role in tissue targeting in vivo, mice were gavaged with DiR-labeled GELNs, PA-deleted GELNs, GELNs plus PC 34:2, grapefruit ELNs, and PC-depleted grapefruit ELNs. Analysis of imaging signals in mouse intestines and livers was performed at 1 hour and 6 hours after the gavage. The results suggested that PA lipids played a role in maintaining the duration and amount of ELN accumulation in the gut. PC lipid enhanced migration of ELNs from the intestine to the liver (see
To determine whether GELNs had an effect on gene expression and protein production in LGG, the efficiency of PKH26-labeled GELN uptake by LGG in an in vitro culture assay was determined. LGG was incubated with PKH26-labeled GELNs for 1 hour at 22° C., and uptake of GELNs by LGG was visualized with confocal microscopy.
GELN uptake in vivo was also evaluated. Briefly, two hours after mice were gavaged with PKH67 fluorescence-labeled LGG (1×109), the mice were administered PKH26-labeled GELNs (500 mg/kg of body weight in 300 μl PBS). Twelve hours after the last gavage, analysis of the PKH67+PKH26+ double-positive bacteria suggested that LGG took up the GELNs. In vitro confocal and in vivo FACS analysis (
An LGG gene expression profile was obtained using next-generation mRNA sequencing (
RNA sequence analysis further revealed that GELN RNAs harboring the complementary seed-matching sequence of LGG mRNA had the potential for binding gut bacterial mRNA (Tables 2 and 3). Evidence indicating a similarity in regulating the composition of gut microbiota of mice fed with GELNs and GELN RNA (see Table 8) prompted a further examination of whether GELN RNAs could modulate bacterial function and in turn host biology. First, evidence showing PKH26-labeled GNVs encapsulating GELN-RNAs were present in LGG was visualized using confocal microscopy. LGG growth in MRS broth was induced by GELN RNAs but not by scrambled RNAs (
Cytokine array analysis (
Whether the GELN-mediated inhibition of IL-1β and TNFα and the increase in IL-22 occurred through the AHR pathway was tested. Knockout (KO) of AHR led to neither inhibition of IL-1β and TNFα expression nor an increase in the expression of IL-22 in AHR KO mice with DSS-induced colitis (
Next, the molecular basis of LGG+GNV/GELN-RNA-mediated induction of IL-22 was tested. LGG metabolizes tryptophan to indole derivates, including I3A, which acts as a ligand for AHR, inducing local production of IL-22. High-performance liquid chromatography (HPLC) analysis indicated that the level of I3A in the feces of GELN-RNA-treated C57BL/6 mice dramatically increased (
The role of I3AM in generation of I3A was then determined. HPLC analysis indicated that addition of I3AM to LGG cultures significantly inhibited GELN-RNA-mediated induction of the I3A precursor, IAAld (
Protein LC-MS/MS and mRNA sequencing analysis indicated that the expression of monooxygenase ycnE (also called antibiotic biosynthesis monooxygenase [Lactobacillus rhamnosus GG]; GENBANK® biosequence database Accession No. CAR87039) in LGG (
To validate that the induction of I3A by GELN-RNAs is gut bacteria-dependent, broad-spectrum antibiotic treatment was used to deplete gut bacteria prior to GELN-RNA administration. The I3A level in feces of antibiotic-treated mice was decreased, and GELN-RNAs no longer induced I3A until additional LGG was administered (see
Whether the AHR pathway in gut lymphocytes of mice gavaged with GELN-RNAs was activated was tested by evaluating phosphorylation of AHR and induction of IL-22. Mice were gavaged with GELN-RNA one week prior to being treated with 2.5% DSS in drinking water for one additional week. Lymphoid cells were then isolated from the colon of treated mice. Western blotting analysis indicated that the levels of cytochrome P450 1A1 (CYP1A1) and phosphorylated AHR increased as a result of GELN-RNA treatment without affecting the total amount of AHR (see
To further address whether the metabolites of LGG treated with GELN-RNAs might have an impact on the induction of IL-22 via the AHR pathway, colon lymphocytes from naïve B6 mice were incubated for 3 hours with I3A, MRS supernatant of LGG treated with GELN-RNAs, or GNVs only. ELISA results indicated that I3A induced expression of IL-22, and more IL-22 was induced when the colon lymphocytes were treated with LGG supernatant (
Dysfunction of the gut epithelial barrier is a hallmark of inflammatory intestinal diseases. The intestinal epithelial barrier is maintained by tight junctions that connect adjacent epithelial cells and seal the paracellular space. IL-22 is critical for maintenance of the intestinal barrier function. Whether GELN-RNA-mediated induction of IL-22 played a causative role in protecting mice against colitis was tested. Indeed, unlike WT mice, IL-22 KO led to a loss of GELN-RNA-mediated protection against DSS-induced colon injury (
LGG that took up GELN-RNAs exhibited reduced migration into the bloodstream and liver of DSS-treated SPF (
The LGG pilus-specific protein SpaC was down-regulated at both the transcriptional and protein levels when LGG was treated with GELNs. Experimentally, based on array data and in vitro transmigration of colon epithelial cell data (see
To further investigate the mechanism underlying how GELN-RNAs prevented LGG migration, nucleotide sequences were aligned using BLAST, and the results indicated that the GELN miRNA ath-miR167a might directly bind to the LGG pilus protein SpaC mRNA and regulate SpaC expression (see Table 3). MC38 cells exposed to LGG treated with seven specifically selected GELN-derived miRNAs indicated that ath-miR167a-5p, ath-miR842 (SEQ ID NO: 82), and ath-miR827 (SEQ ID NO: 81) could prevent the entry of LGG into gut epithelial cells (
Investigation of the effect of GELN miRNA on LGG migration in vivo indicated that ath-miR167a significantly reduced LGG translocation into the peripheral blood, and LGG remained on mucosal surfaces (
To further determine whether SpaC was specifically targeted by miR167a-5p, the effects of SpaC on entry into gut epithelial cells and mucosa-associated LGG and miR167a-5p-treated LGG growth was tesetd. Immuno-TEM demonstrated that SpaC deleted (SpaCdel) LGG had no detectable SpaC. SpaCdel LGG was less efficient in entering MC38 cells than wild-type LGG. Although the gene encoding for SpaC was not detected in SpaCdel LGG (
Then, to further demonstrate the role of endogenous miR167a-5p in the context of GELN RNA, miR167a-5p was depleted from the pooled GELN RNAs with biotinylated anti-sense miR167a-5p. Then, GELN RNA or scrambled miRNA was encapsulated in GNVs. qPCR data indicated that miR167a-5p was successfully depleted from the pooled GELN RNA (
Extensive research has shown that diet modulates the composition and function of the gut microbiota in humans and other mammals (Claesson et al., 2012; Cotillard et al., 2013; Desai et al., 2016; Dey et al., 2015; Lukens et al., 2014; Muegge et al., 2011; Schwarzer et al., 2016; Sonnenburg & Backhed, 2016). Despite the body of knowledge that exists on fecal RNA, the impact of gut RNA on the microbiota is particularly poorly understood. Here, small RNAs and miRNAs from ELNs were identified and found to modulate the composition of gut microbiota and their metabolites and inhibit mouse colitis. At a molecular level, the present disclosure supports the idea that: (1) lipid-enriched ELNs send a signal that causes their uptake by gut bacteria; (2) ELN small RNAs mediate the cross-talk between gut microbiota and the host immune system, shaping the homeostatic balance between immunity and gut microbiota; and (3) ELN RNA regulates the composition, metabolites, growth, and localization of gut microbiota. Specifically, it was determined that gut probiotic LGG I3A induced by GELN-RNA promotes the expression of IL-22 through activation of the AHR signaling pathway, eliciting antimicrobial immunity and tissue repair at barrier surfaces.
A given miRNA can have hundreds of different bacterial mRNA targets (Hausser & Zavolan, 2014), several hundred miRNAs might be encapsulated in a given edible plant ELN, and ELNs from one type of edible plant could have a different miRNA profile than those from other plants. Therefore, it is conceivable that unlike endogenous miRNA released from host intestinal epithelial cells (Liu et al., 2016), which release a limited number of miRNAs, a large number and variety of food-derived ELN miRNAs can be taken up by gut microbiota. In addition, in terms of gut bacterial targeting, the ELNs from one type of edible plant could also have a different lipid profile, resulting in a targeting signal that is distinct from other ELNs. Therefore, a large variety of ELN-derived miRNAs and lipids could meet the requirement for potential regulation of the more than two million genes present in the gut microbiota through dietary-derived ELNs in a lipid targeting and a sequence-specific manner.
All organisms possess a diverse set of genetic programs that are used to alter cellular physiology in response to environmental cues. LexA acts as a transcriptional repressor of the SOS response genes coding primarily for error-prone DNA polymerases, DNA repair enzymes, and cell division inhibitors (Miller et al., 2004). The observation that GELN gma-miR396e (SEQ ID NO: 119) promoted LGG growth at least partly through inhibition of LexA expression supports the hypothesis that ELNs from different types of food could have a role in regulating LexA-mediated SOS activity in the intestinal microenvironment. In addition, since SOS activity has a direct effect on the bacterial cell cycle and survival in general and ELNs from different types of food have preferential bacterial hosts, it is conceivable that the SOS activity in different species of gut bacteria is dependent on what types of food are eaten. Therefore, the present disclosure also supports the hypothesis that ELN-dependent SOS activity has an effect on the composition of gut microbiota through regulating the bacterial cell cycle and bacteria survival.
Ingestion of probiotics, beneficial molecules, or microbes is designed to deliver a health benefit to the host by increasing the numbers of beneficial microbes or their products within the gut. From a therapeutic application aspect, using ginger ELN-derived liposomes, it was possible to orally deliver miRNA to target gut bacteria for treatment of mouse colitis. This strategy could provide an alternate approach for gene therapy in gut dysbiosis-related disease and provide a rationale for ELN-based oral delivery of therapeutic miRNA for treatment of disease due to dysbiosis. It is conceivable that gut bacterial activity regulated by miRNA that interacts with bacterial mRNA in a gene-specific manner will have many advantages over other approaches such as chemotherapy drugs, which induce gut dysbiosis, and antibiotic treatment, which drives rapid development of resistant strains.
A variety of host-derived factors, such as antimicrobial peptides, play a crucial role in selecting and maintaining the stable diversity of the gut microbiota. Edible plant-derived factors that selectively regulate the stability of mucosa-associated microbiota have not been studied in detail. As disclosed herein, it was determined that the ratios of LGG among other species of mucosa-associated microbiota can remain stable, with a shift from mucosal-associated LGG to the majority of the LGG accumulating in the lumen. In zebrafish, an increased level of lumen-associated LGG has a more beneficial effect on gut barrier function than mucosal LGG (He et al., 2017); the role of lumen-associated LGG in mammals is less well understood. The results presented herein explain how GELN small RNAs contribute to gut health via the LGG pilus-specific protein SpaC.
While not wishing to be bound by any particular theory of operation, since all of the diets that have been tested in the past contained ELN small RNAs, the concept that spatial niche partitioning could be governed by diet ELN small RNAs is possible, and this could help to explain both the long-term persistence of relatively stable numbers and the resilience of the microbiota, as well as the resistance to colonization by pathogens. Furthermore, the immune system has an active role in allowing only beneficial species to access these locations during homeostasis, as demonstrated herein above by IL-22. The presently disclosed subject matter thus opens up avenues for investigating whether other factors, such as GELN lipids and ELNs from other diets, can also participate in selection of which particular bacterial species are close to the epithelium and the creation of stable reservoirs for microorganisms to persist in the face of rapidly changing conditions in the gut lumen. Thus, through localized, immune-facilitated and adherence-dependent ELN selection, the host can maintain the stability of a diverse community of microbial symbionts.
In conclusion, given the importance of gut microbiota in human physiology, the findings disclosed herein revealed an important molecular mechanism underlying how diet ELN miRNAs can cross-talk with gut microbiota to maintain gut health. Because the composition of diet-derived ELN miRNAs and lipids is different among diets and each ELN miRNA has targets specific bacterial mRNA, this feature could be utilized for specific manipulation of the microbiome for human health and treatment of dysbiosis-related disease.
All references cited in the instant disclosure, including but not limited to all patents, patent applications and publications thereof, scientific journal articles, and database entries (e.g., GENBANK®, UniprotKB, the NCBI RefSeq database, the Sequence Read Archive database, and the GreenGenes database, including all entries and annotations available therein) are incorporated herein by reference in their entireties to the extent that they supplement, explain, provide a background for, or teach methodology, techniques, and/or compositions employed herein.
It will be understood that various details of the presently disclosed subject matter can be changed without departing from the scope of the subject matter disclosed herein. Furthermore, the foregoing description is for the purpose of illustration only, and not for the purpose of limitation.
Clostridial
Lactobacilli
Enterobacteria
Ruminococcaceae
Lactobacillus rhamnosus
Lactobacillus ruminis
Prevotella melaninogenica
Helicobacter pylori
Ruminococcus bicirculans
Eubacterium rectale
Enterococcus faecalis
Escherichia coli
Clostridium perfringens
Bacteroides fragilis
Akkermansia muciniphila
This application is based on and claims priority to U.S. Provisional Patent Application Ser. No. 62/589,901, filed Nov. 22, 2017, and U.S. Provisional Patent Application Ser. No. 62/686,421, filed Jun. 18, 2018, the disclosure of each of which is incorporated herein by reference in its entirety.
This invention was made with government support under grant numbers UH3TR000875 and R01AT008617 awarded by the National Institutes of Health. The government has certain rights in the invention.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/US2018/062349 | 11/21/2018 | WO | 00 |
| Number | Date | Country | |
|---|---|---|---|
| 62589901 | Nov 2017 | US | |
| 62686421 | Jun 2018 | US |
