Patent ID: 12186329

DETAILED DESCRIPTION OF CERTAIN EMBODIMENTS

The compositions and methods described herein are related, in part, to the discovery that cholic acid-7 sulfate is increased in subjects following bariatric surgery and ameliorates the symptoms of diabetes. Cholic acid-7 sulfate is a TGR5 agonist and induces GLP-1 secretion in vivo and in vitro.

Methods of Treatment and Uses

As generally described herein, provided is a method of treating or preventing diabetes, the method comprising administering to a subject in need thereof an agent that increases the level of cholic acid-7-sulfate in the subject. In one embodiment, the agent is cholic acid-7-sulfate. In one embodiment, the agent is a TGR5 agonist. In one embodiment, the TGR5 agonist is cholic acid-7-sulfate.

In one embodiment, the TGR5 agonist induces GLP-1 secretion from a target cell. In some embodiments, the activity of TGR5 is increased by at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, or more as compared to a control. In some embodiments, the secretion of GLP1 is increased by at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, or more as compared to a control.

In one embodiment, the agent is selected from the group consisting of a small molecule, an antibody, a peptide, a genome editing system, an antisense oligonucleotide, and an RNAi.

In some embodiments, the agent is a vector that encodes the agent. In one embodiment, the vector is non-integrative or integrative. In one embodiment, the vector is a viral vector.

In one embodiment, the agent is formulated with a pharmaceutical composition.

In one embodiment, the pharmaceutical composition is formulated to restrict delivery of an agent to the gastrointestinal tract of the subject.

In one embodiment, the diabetes is type I, type II, neonatal, or maturity onset diabetes in the young.

In one embodiment, the administering reduces glucose levels in the serum of a subject.

In one embodiment, wherein the subject is a mammal.

In one embodiment, the mammal is a human. In certain embodiments, the human is an adult human.

In one embodiment, the target cell is an enteroendocrine cell, an epithelial cell, an L-cell, or a neuron. In certain embodiments, the target cell is an immune cell, leukocyte, muscle cell, or an adipocyte.

In one aspect, described herein is a composition comprising an agent that increases the level of cholic acid-7-sulfate in a subject.

In one embodiment, wherein the agent is cholic acid-7-sulfate.

In one embodiment, the composition is formulated for treating or preventing diabetes.

In one embodiment, the composition further comprises a pharmaceutically acceptable carrier or excipient.

In one embodiment, the carrier or excipient restricts delivery of the composition to the gastrointestinal tract.

In one aspect, described herein is a method for treating or preventing diabetes, the method comprising administering to a subject in need thereof a genetically engineered microorganism or population thereof, that expresses an agent that increases the level of cholic acid-7-sulfate.

In one embodiment, the genetically engineered microorganism is a bacterium.

In one aspect, described herein is a method for treating or preventing diabetes, the method comprising administering to a subject in need thereof a genetically engineered microorganism or population thereof, that secretes cholic acid-7-sulfate.

In one embodiment, the genetically engineered microorganism is a bacterium.

The present disclosure contemplates using cholic acid-7-sulfate for the treatment of diabetes and/or obesity.

Thus, as generally described herein, provided is a method of treating diabetes and/or obesity comprising administering an effective amount of cholic acid-7-sulfate, or a pharmaceutically acceptable salt thereof, to a subject in need thereof. Such a method can be conducted in vivo (i.e., by administration to a subject). Treating, as used herein, encompasses therapeutic treatment and prophylactic treatment.

In some embodiments, the diabetes is type I diabetes, type II diabetes, neonatal diabetes, maturity onset diabetes in the young, or gestational diabetes.

In some embodiments, the diabetes is type II diabetes.

Diabetes can cause many complications. Acute complications (e.g., hypoglycemia, ketoacidosis, or nonketotic hyperosmolar coma) may occur if the disease is not adequately controlled. Serious long-term complications (i.e., chronic side effects) include cardiovascular disease (doubled risk), inflammatory diseases, chronic renal failure, retinal damage (which can lead to blindness), nerve damage (of several kinds), and microvascular damage, which may cause impotence and poor wound healing. Poor healing of wounds, particularly of the feet, can lead to gangrene, and possibly to amputation.

In some embodiments, the diabetes caused by obesity. In one aspect, provided herein is a method of treating obesity in a subject. The term “obesity” refers to excess fat in the body. Obesity can be determined by any measure accepted and utilized by those of skill in the art. Currently, an accepted measure of obesity is body mass index (BMI), which is a measure of body weight in kilograms relative to the square of height in meters. Generally, for an adult over age 20, a BMI between about 18.5 and 24.9 is considered normal, a BMI between about 25.0 and 29.9 is considered overweight, a BMI at or above about 30.0 is considered obese, and a BMI at or above about 40 is considered morbidly obese. (See, e.g., Gallagher et al. (2000)Am J Clin Nutr72:694-701.) These BMI ranges are based on the effect of body weight on increased risk for disease. Some common conditions related to high BMI and obesity include cardiovascular disease, high blood pressure (i.e., hypertension), osteoarthritis, cancer, and diabetes. Although BMI correlates with body fat, the relation between BMI and actual body fat differs with age and gender. For example, women are more likely to have a higher percent of body fat than men for the same BMI. Furthermore, the BMI threshold that separates normal, overweight, and obese can vary, e.g., with age, gender, ethnicity, fitness, and body type, amongst other factors. In some embodiments, a subject with obesity can be a subject with a body mass index of at least about 25 kg/m2prior to administration of a treatment as described herein. In some embodiments, a subject with obesity can be a subject with a body mass index of at least about 30 kg/m2prior to administration of a treatment, compound, or agent as described herein.

In one aspect, provided herein is a method of treating an inflammatory disease in a subject. As used herein, the term “inflammation” or “inflamed” or “inflammatory” refers to activation or recruitment of the immune system or immune cells (e.g., T cells, B cells, macrophages). A tissue that has inflammation can become reddened, white, swollen, hot, painful, exhibit a loss of function, or have a film or mucus. Methods of identifying inflammation are well known in the art. Inflammation generally occurs following injury or infection by a microorganism.

In certain embodiments, the inflammatory disease is Crohn's disease. In certain embodiments, the inflammatory disease is ulcerative colitis. In certain embodiments, the inflammatory disease is pancreatitis. In certain embodiments, the inflammatory disease is hepatitis. In certain embodiments, the inflammatory disease is appendicitis. In certain embodiments, the inflammatory disease is gastritis. In certain embodiments, the inflammatory disease is diverticulitis. In certain embodiments, the inflammatory disease is celiac disease. In certain embodiments, the inflammatory disease is food intolerance. In certain embodiments, the inflammatory disease is enteritis. In certain embodiments, the inflammatory disease is ulcer. In certain embodiments, the inflammatory disease is gastroesophageal reflux disease (GERD). In certain embodiments, the inflammatory disease is psoriatic arthritis. In certain embodiments, the inflammatory disease is psoriasis. In certain embodiments, the inflammatory disease is rheumatoid arthritis.

In some embodiments, the inflammatory disease is an intestinal inflammatory disease. In certain embodiments, the inflammatory disease is associated with inflammation of the gastroinstestinal tract. In certain embodiments, the inflammatory disease is selected from the group consisting of: Crohn's disease, inflammatory bowel disease, ulcerative colitis, pancreatitis, hepatitis, appendicitis, gastritis, diverticulitis, celiac disease, food intolerance, enteritis, ulcer, and gastroesophageal reflux disease (GERD), psoriatic arthritis, psoriasis, and rheumatoid arthritis.

In certain embodiments, the inflammatory disease is an inflammatory bowel disease. In certain embodiments, the inflammatory bowel disease is Crohn's disease. In certain embodiments, the inflammatory bowel disease is ulcerative colitis.

In certain embodiments, the inflammatory disease is an autoimmune disease. In certain embodiments, the autoimmune disease is celiac disease.

In certain embodiments, the effective amount is a therapeutically effective amount. For example, in certain embodiments, the method slows the progression of diabetes and/or obesity in the subject. In certain embodiments, the method improves the condition of the subject suffering from diabetes and/or obesity.

In certain embodiments, the effective amount is a prophylactically effective amount. For example, in certain embodiments, the method prevents or reduces the likelihood of obesity and/or diabetes, e.g., in certain embodiments, the method comprises administering CA7S to a subject in need thereof in an amount sufficient to prevent or reduce the likelihood of obesity and/or diabetes. In certain embodiments, the subject is at risk of obesity and/or diabetes.

As generally described herein, further provided is a method of increasing the amount of cholic acid-7-sulfate in a subject comprising administering an effective amount of cholic acid-7-sulfate, or a pharmaceutically acceptable salt thereof, to a subject in need thereof. Such a method can be conducted in vivo (i.e., by administration to a subject).

As generally described herein, further provided is a method of increasing the activity of TGR5 comprising administering an effective amount of cholic acid-7-sulfate, or a pharmaceutically acceptable salt thereof, to a subject in need thereof. Such a method can be conducted in vivo (i.e., by administration to a subject).

As generally described herein, further provided is a method of increasing GLP-1 secretion in a subject comprising administering an effective amount of cholic acid-7-sulfate, or a pharmaceutically acceptable salt thereof, to a subject in need thereof. Such a method can be conducted in vivo (i.e., by administration to a subject).

Pharmaceutical Compositions and Administration

The present disclosure provides pharmaceutical compositions comprising cholic acid-7-sulfate, or a pharmaceutically acceptable salt thereof, and a pharmaceutically acceptable excipient.

Pharmaceutically acceptable excipients include any and all solvents, diluents, or other liquid vehicles, dispersions, suspension aids, surface active agents, isotonic agents, thickening or emulsifying agents, preservatives, solid binders, lubricants and the like, as suited to the particular dosage form desired. General considerations in formulation and/or manufacture of pharmaceutical compositions agents can be found, for example, inRemington's Pharmaceutical Sciences, Sixteenth Edition, E. W. Martin (Mack Publishing Co., Easton, Pa., 1980), andRemington: The Science and Practice of Pharmacy,21st Edition (Lippincott Williams & Wilkins, 2005).

Pharmaceutical compositions described herein can be prepared by any method known in the art of pharmacology. In general, such preparatory methods include the steps of bringing the cholic acid-7-sulfate into association with a carrier and/or one or more other accessory ingredients, and then, if necessary and/or desirable, shaping and/or packaging the product into a desired single- or multi-dose unit.

Pharmaceutical compositions can be prepared, packaged, and/or sold in bulk, as a single unit dose, and/or as a plurality of single unit doses. As used herein, a “unit dose” is discrete amount of the pharmaceutical composition comprising a predetermined amount of cholic acid-7-sulfate. The amount of cholic acid-7-sulfate is generally equal to the dosage of cholic acid-7-sulfate which would be administered to a subject and/or a convenient fraction of such a dosage such as, for example, one-half or one-third of such a dosage.

Relative amounts of cholic acid-7-sulfate, the pharmaceutically acceptable excipient, and/or any additional ingredients in a pharmaceutical composition will vary, depending upon the identity, size, and/or condition of the subject treated and further depending upon the route by which the composition is to be administered. By way of example, the composition may comprise between 0.1% and 100% (w/w) cholic acid-7-sulfate.

Pharmaceutically acceptable excipients used in the manufacture of provided pharmaceutical compositions include inert diluents, dispersing and/or granulating agents, surface active agents and/or emulsifiers, disintegrating agents, binding agents, preservatives, buffering agents, lubricating agents, and/or oils. Excipients such as cocoa butter and suppository waxes, coloring agents, coating agents, sweetening, flavoring, and perfuming agents may also be present in the composition.

Liquid dosage forms for oral and parenteral administration include pharmaceutically acceptable emulsions, microemulsions, solutions, suspensions, syrups and elixirs. In addition to cholic acid-7-sulfate, the liquid dosage forms may comprise inert diluents commonly used in the art such as, for example, water or other solvents, solubilizing agents, and emulsifiers, and mixtures thereof. Besides inert diluents, the oral compositions can include adjuvants such as wetting agents, emulsifying and suspending agents, sweetening, flavoring, and perfuming agents. In certain embodiments for parenteral administration, the conjugates are mixed with solubilizing agents, and mixtures thereof.

Injectable preparations, for example, sterile injectable aqueous or oleaginous suspensions can be formulated according to the known art using suitable dispersing or wetting agents and suspending agents. The sterile injectable preparation can be a sterile injectable solution, suspension or emulsion in a nontoxic parenterally acceptable diluent or solvent, for example, as a solution in 1,3-butanediol. Among the acceptable vehicles and solvents that can be employed are water, Ringer's solution, U.S.P. and isotonic sodium chloride solution. In addition, sterile, fixed oils are conventionally employed as a solvent or suspending medium.

Solid dosage forms for oral administration include capsules, tablets, pills, powders, and granules. In such solid dosage forms, the cholic acid-7-sulfate is mixed with at least one inert, pharmaceutically acceptable excipient or carrier such as sodium citrate or dicalcium phosphate and/or a) fillers or extenders such as starches, lactose, sucrose, glucose, mannitol, and silicic acid, b) binders such as, for example, carboxymethylcellulose, alginates, gelatin, polyvinylpyrrolidinone, sucrose, and acacia, c) humectants such as glycerol, d) disintegrating agents such as agar, calcium carbonate, potato or tapioca starch, alginic acid, certain silicates, and sodium carbonate, e) solution retarding agents such as paraffin, f) absorption accelerators such as quaternary ammonium compounds, g) wetting agents such as, for example, cetyl alcohol and glycerol monostearate, h) absorbents such as kaolin and bentonite clay, and i) lubricants such as talc, calcium stearate, magnesium stearate, solid polyethylene glycols, sodium lauryl sulfate, and mixtures thereof. In the case of capsules, tablets and pills, the dosage form may comprise buffering agents.

Dosage forms for topical and/or transdermal administration of cholic acid-7-sulfate may include ointments, pastes, creams, lotions, gels, powders, solutions, sprays, inhalants and/or patches. Generally, the cholic acid-7-sulfate is admixed under sterile conditions with a pharmaceutically acceptable carrier and/or any needed preservatives and/or buffers as can be required.

Although the descriptions of pharmaceutical compositions provided herein are principally directed to pharmaceutical compositions which are suitable for administration to humans, it will be understood by the skilled artisan that such compositions are generally suitable for administration to animals of all sorts. Modification of pharmaceutical compositions suitable for administration to humans in order to render the compositions suitable for administration to various animals is well understood, and the ordinarily skilled veterinary pharmacologist can design and/or perform such modification with ordinary experimentation.

Cholic acid-7-sulfate may be formulated in dosage unit form for ease of administration and uniformity of dosage. It will be understood, however, that the total daily amount of CA7S will be decided by the attending physician within the scope of sound medical judgment. The specific therapeutically effective dose level for any particular subject will depend upon a variety of factors including the disease, disorder, or condition being treated and the severity of the disorder; the specific composition employed; the age, body weight, general health, sex and diet of the subject; the time of administration, route of administration, and rate of excretion of the specific compound employed; the duration of the treatment; drugs used in combination or coincidental with CA7S; and like factors well known in the medical arts.

Cholic acid-7-sulfate and compositions provided herein can be administered by any route, including enteral (e.g., oral), parenteral, intravenous, intramuscular, intra-arterial, intramedullary, intrathecal, subcutaneous, intraventricular, transdermal, interdermal, rectal, intravaginal, intraperitoneal, topical (as by powders, ointments, creams, and/or drops), mucosal, nasal, bucal, sublingual; by intratracheal instillation, bronchial instillation, and/or inhalation; and/or as an oral spray, nasal spray, and/or aerosol. In general, the most appropriate route of administration will depend upon a variety of factors including the nature of the agent, the therapeutic regimen, and/or the condition of the subject. Oral administration is the preferred mode of administration. However, in certain embodiments, the subject may not be in a condition to tolerate oral administration, and thus intravenous, intramuscular, and/or rectal administration are also preferred alternative modes of administration.

An effective amount of cholic acid-7-sulfate may be included in a single dose (e.g., single oral dose) or multiple doses (e.g., multiple oral doses). In certain embodiments, when multiple doses are administered to a subject or applied to a tissue or cell, any two doses of the multiple doses include different or substantially the same amounts of CA7S. In certain embodiments, when multiple doses are administered to a subject or applied to a tissue or cell, the frequency of administering the multiple doses to the subject or applying the multiple doses to the tissue or cell is three doses a day, two doses a day, one dose a day, one dose every other day, one dose every third day, one dose every week, one dose every two weeks, one dose every three weeks, or one dose every four weeks. In certain embodiments, a dose (e.g., a single dose, or any dose of multiple doses) described herein includes independently between 0.1 μg and 1 μg, between 0.001 mg and 0.01 mg, between 0.01 mg and 0.1 mg, between 0.1 mg and 1 mg, between 1 mg and 3 mg, between 3 mg and 10 mg, between 10 mg and 30 mg, between 30 mg and 100 mg, between 100 mg and 300 mg, between 300 mg and 1,000 mg, or between 1 g and 10 g, inclusive, of CA7S.

It will be also appreciated that cholic acid-7-sulfate or a composition comprising CA7S, as described herein, can be administered in combination with one or more additional therapeutically active agents. CA7S or a composition comprising CA7S can be administered concurrently with, prior to, or subsequent to, one or more additional therapeutically active agents. In general, each agent will be administered at a dose and/or on a time schedule determined for that agent. In will further be appreciated that the additional therapeutically active agent utilized in this combination can be administered together in a single composition or administered separately in different compositions. The particular combination to employ in a regimen will take into account compatibility of CA7S with the additional therapeutically active agent and/or the desired therapeutic effect to be achieved. In general, it is expected that additional therapeutically active agents utilized in combination be utilized at levels that do not exceed the levels at which they are utilized individually. In certain embodiments, the levels utilized in combination will be lower than those utilized individually.

In certain embodiments, the additional therapeutic agent is an anti-diabetic agent. In certain embodiments, the anti-diabetic agent is selected from the group consisting of insulin, an insulin analog, nateglinide, repaglinide, metformin, thiazolinediones, glitazones such as troglitazone, pioglitazone and rosiglitazone, glisoxepid, glyburide, glibenclamide, acetohexamide, chloropropamide, glibornuride, tolbutamide, tolazamide, glipizide, carbutamide, gliquidone, glyhexamide, phenbutamide, tolcyclamide, glimepiride and gliclazide.

In certain embodiments, the additional pharmaceutical agent is a dipeptidyl peptidase 4 (DPP-4) inhibitor (e.g., sitagliptin, linagliptin, alogliptin, saxagliptin, vildagliptin).

Also provided herein are uses for cholic acid-7-sulfate in treating or preventing disease (e.g., diabetes, obesity) in a subject in need thereof. In certain embodiments, provided herein is cholic acid-7-sulfate, or a composition comprising CA7S, for use in treating or preventing diabetes in a subject. In certain embodiments, provided herein is cholic acid-7-sulfate, or a composition comprising CA7S, for use in treating or preventing obesity in a subject.

Also encompassed by this disclosure are kits (e.g., pharmaceutical packs). The kits provided may comprise a pharmaceutical composition, as described herein, or CA7S and a container (e.g., a vial, ampule, bottle, syringe, and/or dispenser package, or other suitable container). In certain embodiments, provided kits may optionally further include a second container comprising a pharmaceutical excipient for dilution or suspension of a pharmaceutical composition or CA7S. In certain embodiments, the pharmaceutical composition or CA7S provided in the container and the second container are combined to form one unit dosage form.

EXAMPLES

In order that the invention described herein may be more fully understood, the following examples are set forth. The synthetic and biological examples described in this application are offered to illustrate the compounds (e.g., cholic acid-7-sulfate), pharmaceutical compositions, uses, and methods provided herein and are not to be construed in any way as limiting their scope.

General Procedures

Animals. Diet induced obese (DIO), male, C57Bl/6J mice were purchased from Jackson Laboratory (Bar Harbor, ME) at 11-16 weeks of age. They were housed under standard conditions in a climate-controlled environment with 12 hour light and dark cycles and reared on a high fat diet (HFD, 60% Kcal fat; RD12492; Research Diets, NJ). They were allowed to acclimate for at least 1 week prior to undergoing any procedures. All animals were cared for according to guidelines set forth by the American Association for Laboratory Animal Science. All procedures were approved by the Institutional Animal Care and Use Committee.

Sleeve gastrectomy (SG) and sham procedures. 11-week-old DIG mice were purchased and housed as described above. Mice were weight-matched into two groups and either underwent SG or sham operation. SG was performed through a 1.5 cm midline laparotomy under isoflurane anesthesia. The stomach was gently dissected free from its surrounding attachments, the vessels between the spleen and stomach (short gastric vessels) were divided, and a tubular stomach was created by removing 80% of the glandular and 100% of the non-glandular stomach with a linear-cutting surgical stapler. Sham operation consisted of a similar laparotomy, stomach dissection, ligation of short gastric vessels, and manipulation of the stomach along the staple line equivalent. Mice were then individually housed thereafter to allow for monitoring of food intake, weight, and behavior. SG and Sham mice were maintained on Recovery Gel Diet (Clear H2O, Westbrook, ME) from 1 day prior through 6 days after surgery and then were restarted on HFD on the morning of post-operative day (POD) 7. Mice were sacrificed 5-7 weeks post-surgery.

Functional glucose testing. After a 4 hour fast (8 am to noon), intraperitoneal glucose tolerance testing (IPGTT) and insulin tolerance testing (ITT) were performed at post-operative week 4 and 5, respectively. During IPGTT, mice received 2 mg/g of intraperitoneal D-Glucose (Sigma-Aldrich, St. Louis, MO) and serum glucose levels were measured from the tail vein at 15, 30, 60, and 120 min with a OneTouch Glucometer (Life technologies, San Diego, CA). ITT was performed by intraperitoneal instillation of 0.6u/kg of regular human insulin (Eli Lily and Company, Indianapolis, IN) and measurement of serum glucose levels at 15, 30, and 60 min. Baseline glucose was measured for each set prior to medication administration.

Body weight and food intake measurements. Mice were individually housed and weighed daily for the first post-operative week and then twice weekly until sacrifice. Food intake was measured twice weekly and daily food intake was calculated by averaging the grams eaten per day over the preceding days. Note that food intake measurements were started on POD 10 as animals were transitioned from Gel Diet to high fat diet on the morning of POD 7.

Bile acid analysis. Bile acid analyses were performed using a previously reported method (Yao, L. et al. eLife 2018, 7, 675).

Reagents. Stock solutions of all bile acids were prepared by dissolving the compounds in molecular biology grade DMSO (VWR International, Radnor, PA). These solutions were used to establish standard curves. CA7S was purchased from (Caymen Chemicals, Ann Arbor, MI. Cat. No. 9002532). Glyocholic acid (GCA) (Sigma) was used as the internal standard for measurements in mouse tissues. HPLC grade solvents were used for preparing and running UPLC-MS samples.

Extraction. Cecal, liver, and human fecal samples (approximately 50 mg each) and mouse portal veins were pre-weighed in lysis tubes containing ceramic beads (Precellys lysing kit tough micro-organism lysing VK05 tubes for cecal, fecal samples, and portal veins; tissue homogenizing CIKMix tubes for liver samples; Bertin technologies, Montigny-le-Bretonneux, France). 400p L of methanol containing 10 μM internal standard (GCA) was added and the tubes were homogenized in aMagNALyser (6000 speed for 90 s*2, 7000 speed for 60 s). 50 μl of mouse serum was collected in Eppendorf tubes, followed by addition of 50 μL of methanol containing 10 μM internal standard (GCA). After vortexing for 1 min, the sample was cooled to −20° C. for 20 min. All methanol-extracted tissue samples were centrifuged at 4° C. for 30 min at 15,000 rpm. The supernatant was diluted 1:1 in 50% methanol/water and centrifuged again at 4° C. for 30 min at 15000 rpm. The supernatant was transferred into mass spec vials and injected into the UPLC-MS.

UPLC-MS. Samples were injected onto a Phenomenex 1L7 μm, C18 100 Å, 100×21 mm LC column at room temperature and eluted using a 30 min gradient of 75% A to 100% B (A=water+0.05% formic acid; B=acetone+0.05% formic acid) at a flow rate of 0.350 mL/min. Samples were analyzed using an Agilent Technologies 12990 Infinity 11 UPLC system coupled online to an Agilent Technologies 6120 Quadrupole LC/MS spectrometer in negative electrospray mode with a scan range of 350-550 m/z (MSD settings: fragmentor—250, gain—3.00, threshold—150, Step size—0.10, speed (u/sec)—743). Capillary voltage was 4500 V, drying gas temperature was 300° C., and drying gas flow was 3 L/min. Analytes were identified according to their mass and retention time. For quantification of the analytes, standard curves were obtained using known bile acids, and then each analyte was quantified based on the standard curve and normalized based on the internal standard. The limit of detection for CA7S is 0.05 picomol/μL. Note that CA7S and cholic acid-3-sulfate can be distinguished based on retention time using this UPLC-MS method.

Purification of CA7S. Extracted cecal contents from 11 SG mice (same shown inFIG.1) were pooled to provide sufficient material for purification. Pooled extract was purified via MS-guided HPLC of m/z 487 using a Luna RP C18 semi-preparative column and water and acetonitrile with 0.1% formic acid as an additive.

NMR Spectroscopy. CA7S and purified m/z 487 (<1 mg) were dissolved in 250 μL DMSO-d6. Nuclear magnetic resonance (NMR) spectra were acquired on a Varian INOVA 500 MHz and are referenced internally according to residual solvent signals (DMSO to 2.50, HOD to 3.33).

Cell culture. NCI-H716 cells and Caco-2 cells were obtained from American Type Culture Collection (Manassas, VA). HEK-293T cells were a kind gift from the Blacklow lab (BCMP, HMS). Caco-2 and HEK-293T cells were maintained in Minimum Essential Medium (MEM) with GlutaMAX and Earle's Salts (Gibco, Life Technologies, UK). NCI-H716 cells were maintained in RPMI 1640 with L-glutamine (GenClone, San Diego, CA). All cell culture media were supplemented with 10% fetal bovine serum (FBS), 100 units/ml penicillin, and 100 μg/ml streptomycin (GenClone). Cells were grown in FBS- and antibiotic-supplemented ‘complete’ media at 37° C. in an atmosphere of 5% CO2.

In vitro bile acid treatments. NCI-H716 cells were seeded in cell culture plates coated with Matrigel (Corning, NY. Cat. No. 356234) diluted in Hank's Balanced Salt Solution (HBSS, Gibco) according to manufacturer's instructions. The cells were allowed to grow for 2 days in complete RPMI media. On the day of the treatment, cells were rinsed gently with low serum (0.5% FBS) RPMI 1640 medium without antibiotics. Bile acids cholic acid-7-sulfate (CA7S), cholic acid (CA) (Sigma) and taurodeoxycholic acid (TDCA) (Sigma) were diluted in dimethyl sulfoxide (DMSO, VWR International) and added to cells in the low serum media (0.5% FBS, RPMI 1640) without antibiotics. The concentration of DMSO was kept constant throughout the treatments and used as a negative control. Cells were incubated at 37° C. in an atmosphere of 5% CO2 for 2 hours. After the incubation period, cell culture media was collected in Eppendorf tubes containing 1% trifluoroacetic acid (TFA, Sigma) in sterile purified water (GenClone) to make a final TFA concentration of 0.1% and frozen at −80° C. for further GLP-1 measurements. Cells on cell culture plates were placed on ice and gently washed with PBS (GenClone). Cells used for GLP-1 measurements were treated with ice-cold cell lysis solution of 1% TFA, 1N hydrochloric acid, 5% formic acid, and 1% NaCl (all from Sigma), scraped off of the Matrigel coating, and collected in lysing tubes with ceramic beads (Precellys lysing kit tough micro-organism lysing VK05 tubes). For calcium measurements, PBS was added to cells, and were collected in lysing tubes containing ceramic beads (Precellys lysing kit tough micro-organism lysing VK05 tubes). Cells were thereafter lysed in a MagNA Lyser and stored at −80° C. for further analysis. Cells used for RNA extraction were treated with TRIzol (Ambion, Life Technologies, Thermo Fisher Scientific, Waltham, Mass.) and stored at −80° C. for further analysis.

GLP-1 and Insulin measurements. Total GLP-1 peptide measurements were performed using the GLP-1 EIA Kit (Sigma, Cat. No. RAB0201) and total insulin levels were measured using the Mouse Ins1/Insulin-1 ELISA kit (Sigma, Cat. No. RAB0817) according to manufacturer's instructions. Mouse serum samples, NCI-H716 cell lysates, and cell culture media samples were stored at −80° C. and thawed on ice prior to performance ELISA assay. 20 μl of mouse serum samples were used directly in the GLP-1 ELISA assay, while 50 μl of mouse serum samples were used directly in the Insulin ELISA assay. Cell culture media were centrifuged at 12000 rpm, and the supernatant was directly used in the GLP-1 ELISA assay. Cell lysates were subjected to peptide purification using Sep Pak C18 Classic columns (Waters Corporation, Milford, MA). The column was pretreated with a solution of 0.1% TFA in 80% isopropyl alcohol (EMD Millipore) and equilibrated with 0.1% TFA in water. Cell lysates were loaded onto the column and washed with 0.1% TFA in 80% isopropyl alcohol. The peptides were eluted in 0.1% TFA in water. The eluate was concentrated by drying under vacuum and resuspended in 0.1% TFA in water. Water was used as ‘blank’ reading for serum GLP-1 ELISA, while 0.1% TFA in water was used as ‘blank’ for cell culture media and purified cell lysate ELISAs. Excess samples were stored at −80° C. for later analyses. Total GLP-1 amounts in the cell culture media (secreted) and cell lysates were calculated using a standard curve provided in the EIA kit. Percentage GLP-1 secretion was calculated as follows: % GLP-1 secretion=total GLP-1 secreted (media)/(total GLP-1 secreted (media)+total GLP-1 in cell lysates)*100. Relative GLP-1 secretion was calculated compared to DMSO control.

Plasmids and transient transfections. Human TGR5 was cloned using cDNA from human Caco-2 cells as template and a forward primer with an EcoRI restriction-site (5′-CGGAATTCGCACTTGGTCCTTGTGCTCT-3′) (SEQ ID NO: 1) and a reverse primer with a XhoI-site (5′-GTCTCGAGTTAGTTCAAGTCCAGGTCGA-3′) (SEQ ID NO: 2). The PCR product was cloned into the pCDNA 3.1+ plasmid (Promega Corporation, Madison, WI) and transfected at a concentration of 0.4 μg/ml of media. For luciferase reporter assays for TGR5 activation, the pGL4.29[luc2P/CRE/Hygro] plasmid (Promega Corporation), and the pGL4.74[hRluc/CMV] plasmid (Promega Corporation) were used at concentration of 2 μg/ml and 0.05 μg/ml of media respectively. All plasmids were transfected using Opti-MEM (Gibco) and Lipofectamine 2000 (Invitrogen, Life Technologies, Grand Island, NY., USA) according to manufacturer's instructions. Plasmid transfection were performed in antibiotic-free media (MEM for HEK293T and RPMI for Matrigel-attached NCI-H716 cells) with 10% FBS. After overnight incubation, bile acids were added in complete media and incubated overnight. Cells were harvested the next day for luciferase assay. TGR5 siRNA (Santa Cruz Biotechnology, Dallas, TX) and negative siRNA (Ambion) transfection was performed using Opti-MEM and Lipofectamine 2000 according to manufacturer's instructions. After siRNA transfection, cells were incubated in antibiotic- and serum-free media (RPMI for Matrigel-attached NCI-H716 cells) for 24 hours. The next day, the media was replaced by complete media and incubated overnight. Bile acids were added 48 hours post-siRNA transfection in complete media and incubated overnight. Cells were harvested the next day for luciferase assay or RNA extraction.

Luciferase reporter assay. Luminescence was measured using the Dual-Luciferase Reporter Assay System (Promega Corporation) according to manufacturer's instructions. Cells were washed gently with PBS and lysed in PLB from the kit. Matrigel-attached cells were scraped in PLB. Luminescence was measured using the SpectraMax M5 plate reader (Molecular Devices, San Jose, CA) at the ICCB-Longwood Screening Facility at Harvard Medical School. Luminescence was normalized toRenillaluciferase activity and percentage relative luminescence was calculated compared to DMSO control.

Calcium measurement. CA7S-treated NCI-H716 cells collected in PBS were used to measure intracellular calcium using the Calcium Assay Kit (Fluorometric) (Abcam, UK). Cell lysates were centrifuged at 12000 rpm, and the supernatant was directly used in the calcium assay according to manufacturer's instructions. Fluorescence was measured using the SpectraMax M5 plate reader (Molecular Devices, San Jose, CA) at the ICCB-Longwood Screening Facility at HMS. Percentage relative fluorescence was calculated compared to DMSO control.

Cell viability assay. Caco-2 cells were treated with CA7S diluted in DMSO in complete MEM media. The concentration of DMSO was kept constant and used as a negative control. Cells were incubated with CA7S overnight at 37° C. in an atmosphere of 5% CO2. The next day, cells were treated with 0.25% trypsin in HBSS (GenClone) for 10 min at 37° C. Cell viability was measured in Countess II automated cell counter (Invitrogen). Percentage relative viability was calculated compared to DMSO control.

pH stability test. Stability of CA7S in physiological pH's was determined using the Waters pH stability test. Briefly, buffers of pH 1 (0.1 M HCl), pH 7.4 (PBS) and pH 9 (a 10 mM solution of ammonium formate adjusted to pH 9 with ammonium hydroxide) (all from Sigma) were prepared. CA7S was incubated in the pH buffers overnight at 37° C. with gentle shaking (50 rpm). The next day, the CA7S solution was diluted in methanol, transferred into mass spec vials and injected into the UPLC-MS.

RNA extraction and qPCR. Cells frozen in TRIzol (Ambion) were collected in RNase-free Eppendorf tubes and vortexed for 30 seconds. Tissues were collected in Precellys tubes with ceramic beads and TRIzol, followed by homogenization in a MagNA Lyser (Roche, Switzerland). Tubes were kept on ice whenever possible. Chloroform was added (200 μl chloroform/1 ml TRIzol) and vortexed for 30 seconds. Tubes were centrifuged at 12,000 rpm for 15 min at 4° C. The clear top layer was transferred to new RNase-free Eppendorf tubes containing 2-propanol and inverted to mix (500 μl 2-propanol/1 ml TRIzol). Tubes were centrifuged at 12,000 rpm for 10 min at 4° C. The pellet was washed with 70% EtOH and centrifuged at 14,000 rpm for 5 minutes at 4° C. The RNA pellet was air-dried and resuspended in RNase-free H2O (GenClone). cDNA synthesis was performed using the High Capacity cDNA Reverse Transcription Kit (Applied Biosystems, Invitrogen, Foster City, CA). qPCR was performed using the Lightcycler 480 SYBR Green I Mater (Roche, Switzerland) in a 384-well format using a LightCycler 480 System (Roche) at the ICCB-Longwood Screening Facility at Harvard Medical School. The 2−ΔΔctmethod was used to calculate the relative change in gene expression. Human TGR5 gene expression were normalized to the human HPRTI (HGPRT). Mouse GLP-1R gene expression was normalized to 18S. Primer sequences were:

human TGR5:Forward:(SEQ ID NO: 3)5′-CCTAGGAAGTGCCAGTGCAG-3′,Reverse:(SEQ ID NO: 4)5′-CTTGGGTGGTAGGCAATGCT-3′;human HGPRT:Forward:(SEQ ID NO: 5)5′-CCTGGCGTCGTGATTAGTGA-3′,Reverse:(SEQ ID NO: 6)5′-CGAGCAAGACGTTCAGTCCT-3′;mouse GLP-1R:Forward:(SEQ ID NO: 7)5′-AGGGCTTGATGGTGGCTATC-3′,Reverse:(SEQ ID NO: 8)5′-GGACACTTGAGGGGCTTCAT-3′;mouse 18S:Forward:(SEQ ID NO: 9)5′-ATTTGGAGCTGGAATTACCGC-3′,Reverse:(SEQ ID NO: 10)5′-CGGCTACCACATCCAAGGAA-3′.

In vivo enteral treatment with CA7S. 13-week-old male C57Bl/6J mice were purchased, acclimated, and housed as above. They were weight matched into two groups (p=0.88). After an overnight fast (17:00 to 0800), mice received either CA7S or PBS via direct duodenal and rectal administration. The optimal, physiologic dose of CA7S was extrapolated from the average pmol concentration of CA7S found in cecal samples from SG animals (average of 3000 pmol/mg of stool with 500 mg of stool per animal corresponds to 0.75 mg of CA7S per cecum).

Under isoflurane general anesthesia, 0.25 mg and 0.75 mg of CA7S in PBS (pH 7.2) was delivered by slow infusion (5 min) antegrade into the duodenum and retrograde into the rectum, respectively. The total volume of instillation was 2 mL (0.5 mg CA7S/mL). Control animals received similar volumes of PBS alone. 15 min post infusion, serum glucose was measured via tail vein followed by whole blood collection via cardiac puncture into K+EDTA tubes containing DPPIV inhibitor (Merck Millipore, Billerica, Mass.), Perfabloc (Sigma), and apoprotinin (Sigma). Organs were harvested for analysis. In order to account for changes in fasting times and hormonal diurnal rhythms, this experiment was carried out on four consecutive days such that only four mice were tested per day.

In vivo CA7S gavage. 16-week-old DIG mice were purchased and housed as described above. Mice were gavaged orally with 100 mg/kg CA7S from 20 mg/mL solution, or equivalent volume of PBS using 20G×38 mm gavage needle. 5 hours after CA7S/PBS administration, whole blood and intestinal segments were collected.

In vivo CA7S and OGTT. Age matched, DIG mice were kept on HFD and their blood glucose levels were monitored until average fasting glucose levels were >160 mg/dL. Animals were fasted for 4 hours on the day of the experiment. Mice were matched into two groups based on fasting glucose levels and received either 100 mg/kg CA7S from a 20 mg/ml solution or an equivalent volume of PBS by oral gavage. Three hours later, an OGTT was performed using an oral gavage of 2 mg/g oral D-glucose (Sigma-Aldrich, St. Louis, Mo.). Blood glucose levels were measured at baseline and at minutes 15, 30, 60 and 120 with a OneTouch glucometer.

Lentiviral IP injection. GLP-1R shRNA-containing lentiviral particles (LVP) were purchased from the MISSION TRC library (Sigma-Aldrich, St. Louis, Mo.). LVPs containing a mixture of three GLP-1R shRNA plasmid clones (TRCN0000004629, TRCN0000004630, and TRCN0000004633) were purchased, stored at −80° C., and thawed on ice before use. DIG mice were maintained on a HFD until average fasting glucose >160 mg/dL in a BL2 facility. Under sterile conditions, mice were injected intraperitoneally with 0.2 ml of 5×105GLP-1R shRNA LVPs with a 27G needle (Tiscornia, G., et al. PNAS 2003, 100, 1844-1848; Blosser, W. et al. PLOS ONE 2014, 9, e96036). 72 hours after LVP injection, mice underwent CA7S/PBS gavage followed by OGTT as above. After the OGTT was completed, mice were sacrificed and their tissues were harvested. GLP-1R knock-down efficiency was measured in tissues by qPCR as described above.

Human stool collection. After obtaining institutional review board approval, we prospectively collected stool specimen from obese human subjects undergoing SG. Pre-operative stool specimens were collected on the day of surgery and post-operative stool specimen were obtained from post-operative day 14 to 99 (mode 15 days; median 36 days). Specimens were snap frozen in liquid nitrogen and stored at −80° C. until bile acid analysis was performed (as above).

Example 1. Glucose and Bile Acid Profiles Post-Gastric Sleeve Surgery Mouse Model

The mouse model described herein is used to study the amelioration of diabetic phenotypes post-sleeve surgery. Mice are suitable model for bariatric surgery-induced amelioration of diabetic phenotypes. High fat diet-fed mice post-sleeve show improved glucose tolerance and insulin sensitivity (FIGS.1A and1B) consistent with what has been observed before in humans.

Bile acid profiling was performed and revealed significant changes in individual bile acids in mice post-sleeve. Mice 6 weeks post-sleeve have higher levels of cholic acid-7-sulfate in their cecum compared to sham-operated mice (FIG.2). It was confirmed that the molecule in the bile acid was cholic acid-7-sulfate by NMR. Furthermore, mice post-sleeve have lower levels of secondary bile acid LCA and components of the “CDCA pathway” including CDCA, TCDCA, and iso-LCA in their cecum (FIG.2).

The total bile acids and other bile acids did not differ significantly in cecum of mice operated with sleeve or sham surgery (FIG.7). Sleeve mice livers showed increased cholic acid-7-sulfate, CDCA, and TCDCA (FIG.3). However, total bile acids and other bile acids did not differ significantly in liver of mice operated with sleeve or sham surgery (FIG.8).

Example 2. Increased GLP1 and TGR5 Activation with Cholic Acid-7-Sulfate

It was observed that sleeve mice show increase in GLP-1 in systemic circulation (FIG.4A). Cholic acid-7-sulfate induces GLP-1 secretion in vitro better than the known GLP-1 inducer TDCA, while cholic acid had no effect (FIG.4BandFIG.9).

To identify a particular target of cholic acid-7-sulfate, it was discovered that cholic acid-7-sulfate-mediated induction of GLP-1 and requires TGR5. This was confirmed when knockdown of TGR5 abolished GLP-1 secretion (FIG.4BandFIG.9A). Therefore, cholic acid-7-sulfate is a TGR5 agonist and induces GLP-1 secretion in vitro.

To further investigate this mechanism, cholic acid-7-sulfate was extracted from cecum of mice and found to also exhibit activity inducing GLP-1 secretion in vitro (FIG.4C). Cholic acid-7-sulfate activates TGR5 in L-cells, dose response curve shows an EC50 of 0.013 μM (FIG.4D). Cholic acid-7-sulfate increased calcium levels in L-cells in vitro (FIG.9B). Cholic acid-7-sulfate induces TGR5 activation in HEK293T cells (FIG.9C).

Cholic acid-7-sulfate is stable in a wide range of pHs, and has no toxicity in intestinal Caco cells in vitro (FIGS.5A and5B). Treatment of HFD-fed mice with cholic acid-7-sulfate in vivo reduced blood glucose levels and induced GLP-1 levels within 15 min. of treatment (FIGS.5C and5D). Therefore, acute cholic acid-7-sulfate treatment induces GLP-1 and reduces serum glucose levels in vivo. Dosing with 1 mg cholic acid-7-sulfate resulted in ˜2500 μM cholic acid-7-sulfate in the cecum, similar to the amounts we saw in sleeve-operated mice (FIG.5E). Ectopic introduction of cholic acid-7-sulfate allowed only minor amounts to leak into systemic circulation and in the portal vein, and did not significantly affect other bile acids in the cecum, blood, or the portal vein (FIGS.5F and5G,FIGS.10,11, and12). Feces from human patients pre- and post-sleeve gastrectomy also have an increase in cholic acid-7-sulfate (FIG.5H).

Human fecal samples post-sleeve have a reduction in levels of secondary bile acids LCA, iso-LCA, and UDCA, similar to what was observed in mice post-sleeve (FIG.13). Other bile acids and total bile acids were not significantly affected, except for calcium levels. (FIG.13).

Example 3. SULT2A Induction and Bile Acid Profile in Liver and Blood

Sulfation is a detoxification method to excrete toxic bile acids. Bile acids have been shown to tightly regulate their own synthesis, conjugation, and sulfation. The liver is the major site for synthesis and sulfation of bile acids, therefore bile acids in the hepatic portal vein were analyzed to determine the origin of sulfated cholic acid and a mechanism for the increase in cholic acid-7-sulfate in sleeve mice. The hepatic portal vein is part of the enterohepatic circulation of bile acids. The liver receives 80% of its blood from the hepatic portal vein. The portal vein has a different repertoire of bile acids compared to circulating blood (FIG.6B&FIG.14).

Mice livers show an increase in SULT2A enzyme isoform 1, previously shown to sulfate bile acids (FIG.6A).

To not be bound by a particular theory, it was hypothesized that bile acids in the hepatic portal vein signal in the liver to induce sulfation of cholic acid. Pools of bile acids were tested mimicking those observed in the sleeve- and sham-operated mouse portal veins in inducing SULT2A1 in vitro. Using HepG2 cells, it was observed that the bile acid pool in the portal vein of sleeve-operated mice significantly induced SULT2A1 compared to the portal vein bile acid pool in sham-operated mice (FIG.6C).

Bile acids are modified in the intestine by the microbiome. Therefore, the influence of the microbiome in inducing sulfation of bile acids in the liver was tested. Sleeve gastrectomy was performed and sham surgery on HFD-fed mice treated with antibiotics. Pools of bile acids mimicking those observed in the antibiotic-treated sleeve- and sham-operated mouse portal veins were tested inducing SULT2A1 in HepG2 cells. There was no difference in induction of SULT2A1 between the pools observed (FIGS.6D and6E).

Consistently, it was observed that there was no cholic acid-7-sulfate in the liver and approximately 200-fold lower levels of cholic acid-7-sulfate in the cecum in antibiotic-treated mice (FIG.14andFIG.15) compared to HFD-fed conventional mice. Also, there was no significant difference in cholic acid-7-sulfate levels between antibiotic-treated sleeve- and sham-operated mouse cecum (FIG.9). This suggests that a microbiome is required for sulfation of cholic acid. In support of this hypothesis, germ-free animals fed a high fat diet also show 200-fold lower cholic acid-7-sulfate in their cecum (FIG.9).

To test which bile acid(s) may be involved in inducing SULT2A1 enzyme, the bile acids in the portal vein that were significantly different between HFD-fed conventional mice and HFD-fed mice treated with antibiotics were analyzed. It was observed that LCA, TDCA, CA, and CDCA were absent in the antibiotic-treated mouse portal veins (FIG.6D).

Amongst these, LCA induced SULT2A1 in HepG2, while others did not in all concentrations tested (FIG.6F). LCA levels were also increased in sleeve mice compared to sham-operated, while the total bile acid levels did not differ significantly, suggesting that LCA is an inducer of SULT2A1 expression (FIG.6B). To identify the receptor involved in LCA-mediated induction of SULT2A1 in liver cells, siRNA of known receptors was performed. The PXR receptor was consistently upregulated in mice post-sleeve in the liver (FIGS.6G and6H).

Example 4. Identification of Cholic Acid-7-Sulfate

The individual bile acids in cecal contents of post-gastric sleeve (SG) and sham mice were quantified using UPLC-MS. A significant increase in a monosulfated, trihydroxy BA in cecal contents of SG mice was observed. Using NMR spectroscopy, the compound was identified as cholic acid-7-sulfate (CA7S) (FIGS.17D and17E). This molecule is a sulfated metabolite of cholic acid (CA), which is an abundant primary BA in both mice and humans. Sulfation of BAs predominantly occurs in the liver (Alnouti, Y. Toxicol. Sci. 2009, 108, 225-246). Increased levels of CA7S in the liver of SG mice were also found (FIG.17F). CA7S was the only BA detected whose levels were significantly higher in SG mouse livers and cecal contents.

Bile acids in stool from human patients who had undergone SG were quantified. Fecal CA7S levels were also significantly increased in patients post-SG compared to their pre-surgery levels (FIG.1G).

Example 5. CA7S Activation of Human TG R5 in HEK293T Cells

The activation of human TGR5 was examined in human embryonic kidney cells (HEK293T) by CA7S, CA, or tauro-deoxycholic acid (TDCA) which is a naturally occurring BA and potent TGR5 agonist (Brighton, C. A. et al. Endocrinology 2015 156, 3961-3970). It was found that CA7S activated human TGR5 in a dose-dependent manner and to a similar extent as TDCA. CA7S also displayed a lower EC50(0.17 μM) than CA (12.22 μM) (FIG.17H).

CA7S induced GLP-1 secretion in human intestinal L-cells (NCI-H716) to a similar degree as TDCA in a dose-dependent manner, while CA had no effect on GLP-1 secretion (FIGS.17I and21A). CA7S extracted directly from cecal contents of SG mice also induced GLP-1 secretion in vitro (FIG.21B). Furthermore, siRNA-mediated knockdown of TGR5 abolished both CA7S and TDCA-mediated secretion of GLP-1 (FIGS.17I,21A, and21C). This result indicates that induction of GLP-1 secretion by CA7S requires TGR5. TGR5 agonism also results in elevated intracellular calcium levels (Kuhre, R. E. et al. Journal of Molecular Endocrinology 2016, 56, 201-211). Consistent with this previous finding, we observed a dose-dependent increase in calcium levels in NCI-H716 cells treated with CA7S (FIG.21D). Taken together, these results demonstrate that CA7S, a naturally occurring BA metabolite, is a potent TGR5 agonist and GLP-1 secretagogue.

Example 6. Evaluation of Acute Anti-Diabetic Effects In Vivo

DIO mice were treated with either CA7S or PBS via duodenal and rectal catheters (FIG.18A). Administration of 1 mg of CA7S resulted in an average of 2500 pmol/mg wet mass of CA7S in cecal contents, a concentration similar to observed post-SG levels (FIG.17E,18B, Table 1).

TABLE 1Cholic acid-7-sulfate concentration in indicated tissues and bloodCA7S concentrationTreatmentTissue/blood(mean ± SEM)DIO mice; sham surgeryCecum1726 ± 267 pmol/mgLiver0.12 ± 0.04 pmol/mgPortal veinn.d.Systemic bloodn.d.DIO mice; sleeveCecum2661 ± 331 pmol/mggastrectomyLiver0.27 ± 0.04 pmol/mgPortal veinn.d.Systemic bloodn.d.DIO mice; enteral PBSCecum161.1 ± 46.4 pmol/mgPortal vein0.07 ± 0.06 pmol/mgSystemic bloodn.d.DIO mice; enteral CA7SCecum2577 ± 185 pmol/mgPortal vein6.13 ± 2.11 pmol/mgSystemic blood0.5 ± 0.2 pmol/μlDIO mice; PBS gavageCecum947 ± 349 pmol/mgPortal veinn.d.Systemic bloodn.d.DIO mice; CA7S gavageCecum14345 ± 1451 pmol/μlPortal vein13.2 ± 7.7 pmol/μlSystemic bloodn.d.n.d. not detected, all data are presented as mean ± SEM.

CA7S-treated mice displayed increased systemic GLP-1 levels compared to PBS-treated mice within 15 minutes (FIG.18C). Moreover, CA7S-treated mice exhibited reduced blood glucose levels and increased insulin levels compared to PBS-treated mice (FIGS.18D,18E, and21E). GLP-1-producing enteroendocrine L-cells are enriched in the distal compared to the proximal gut (Eissele, R. et al. Eur. J. Clin. Invest. 1992 22, 283-291; Harach, T. et al. Sci Rep 2012, 2, 430). It was observed that TGR5 expression was increased in the colon, but not the terminal ileum, of CA7S-treated mice (FIG.18F). Without wishing to be bound by any particular theory, these results may suggest that in an acute setting, distal action of CA7S in the GI tract induces systemic glucose clearance and thus ameliorates hyperglycemia.

Example 7. Antidiabetic Effects of CA7S Over Prolonged Periods

DIO mice were orally gavaged with CA7S at a dose of 100 mg/kg (FIG.19A). Analysis of cecal contents 5 hours post-gavage showed an accumulation of 15,000 picomol/mg wet mass of CA7S (mean value,FIG.19B), a concentration that is within an order of magnitude of the mean amount measured in post-SG mice. These data indicate that we had administered a physiologically relevant concentration of this metabolite. Systemic levels of GLP-1 were increased in CA7S-gavaged mice compared to PBS-treated mice 5 hours post-treatment (FIG.19C). This result is consistent with the findings from enteral administration and demonstrates that oral CA7S treatment can increase circulating GLP-1 for several hours.

The effect of CA7S on glucose tolerance over time was also determined using an oral glucose tolerance test (OGTT). DIO mice were gavaged with CA7S (100 mg/kg) or PBS and then administered an oral glucose bolus 3 hours later. CA7S treatment resulted in an increased rate of blood glucose clearance (FIG.19D). Moreover, the total and incremental areas under the glucose versus time curves (AUC and iAUC) were significantly decreased in CA7S-compared to vehicle-treated mice (FIG.19E).

Example 8. Dependency of Anti-Diabetic Effects of CA7S on GLP-1

Lentiviral shRNA-mediated knockdown of GLP-1R was carried out in vivo. DIO mice were injected intraperitoneally with 5×105shRNA lentiviral particles targeting GLP-1R. At day 3 post-injection, expression of GLP-1R in the intestines, heart, liver, and stomach was significantly reduced, and importantly, the expression of GLP-1R was undetectable in the pancreas (FIG.22A). Mice were then gavaged with CA7S (100 mg/kg) or PBS and subjected to an OGTT 3 hours post-gavage. There were no significant differences in the glycemic curves or AUCs between CA7S-treated and PBS-treated mice in the absence of GLP-1R, suggesting that in an acute setting, the blood glucose clearing-effects of CA7S are largely dependent on GLP-1 (FIGS.19F and19G).

EQUIVALENTS AND SCOPE

In the claims articles such as “a,” “an,” and “the” may mean one or more than one unless indicated to the contrary or otherwise evident from the context. Claims or descriptions that include “or” between one or more members of a group are considered satisfied if one, more than one, or all of the group members are present in, employed in, or otherwise relevant to a given product or process unless indicated to the contrary or otherwise evident from the context. The invention includes embodiments in which exactly one member of the group is present in, employed in, or otherwise relevant to a given product or process. The invention includes embodiments in which more than one, or all of the group members are present in, employed in, or otherwise relevant to a given product or process.

Furthermore, the invention encompasses all variations, combinations, and permutations in which one or more limitations, elements, clauses, and descriptive terms from one or more of the listed claims is introduced into another claim. For example, any claim that is dependent on another claim can be modified to include one or more limitations found in any other claim that is dependent on the same base claim. Where elements are presented as lists, e.g., in Markush group format, each subgroup of the elements is also disclosed, and any element(s) can be removed from the group. It should it be understood that, in general, where the invention, or aspects of the invention, is/are referred to as comprising particular elements and/or features, certain embodiments of the invention or aspects of the invention consist, or consist essentially of, such elements and/or features. For purposes of simplicity, those embodiments have not been specifically set forth in haec verba herein. It is also noted that the terms “comprising” and “containing” are intended to be open and permits the inclusion of additional elements or steps. Where ranges are given, endpoints are included. Furthermore, unless otherwise indicated or otherwise evident from the context and understanding of one of ordinary skill in the art, values that are expressed as ranges can assume any specific value or sub-range within the stated ranges in different embodiments of the invention, to the tenth of the unit of the lower limit of the range, unless the context clearly dictates otherwise.

This application refers to various issued patents, published patent applications, journal articles, and other publications, all of which are incorporated herein by reference. If there is a conflict between any of the incorporated references and the instant specification, the specification shall control. In addition, any particular embodiment of the present invention that falls within the prior art may be explicitly excluded from any one or more of the claims. Because such embodiments are deemed to be known to one of ordinary skill in the art, they may be excluded even if the exclusion is not set forth explicitly herein. Any particular embodiment of the invention can be excluded from any claim, for any reason, whether or not related to the existence of prior art.

Those skilled in the art will recognize or be able to ascertain using no more than routine experimentation many equivalents to the specific embodiments described herein. The scope of the present embodiments described herein is not intended to be limited to the above Description, but rather is as set forth in the appended claims. Those of ordinary skill in the art will appreciate that various changes and modifications to this description may be made without departing from the spirit or scope of the present invention, as defined in the following claims.