ABSTRACT
BACKGROUND: Nutritional agents have modest efficacy in reducing weight and blood glucose in animal models and humans, but combinations are less well characterized. GSK2890457 (GSK457) is a combination of 4 nutritional agents, discovered by the systematic assessment of 16 potential components using the diet-induced obese mouse model, which was subsequently evaluated in a human study. NONCLINICAL RESULTS: In the diet-induced obese mouse model, GSK457 (15% w/w in chow) given with a long-acting glucagon-like peptide -1 receptor agonist, exendin-4 AlbudAb, produced weight loss of 30.8% after 28 days of treatment. In db/db mice, a model of diabetes, GSK457 (10% w/w) combined with the exendin-4 AlbudAb reduced glucose by 217 mg/dL and HbA1c by 1.2% after 14 days. CLINICAL RESULTS: GSK457 was evaluated in a 6 week randomized, placebo-controlled study that enrolled healthy subjects and subjects with type 2 diabetes to investigate changes in weight and glucose. In healthy subjects, GSK457 well tolerated when titrated up to 40 g/day, and it reduced systemic exposure of metformin by ~ 30%. In subjects with diabetes taking liraglutide 1.8 mg/day, GSK457 did not reduce weight, but it slightly decreased mean glucose by 0.356 mmol/L (95% CI: -1.409, 0.698) and HbAlc by 0.065% (95% CI: -0.495, 0.365), compared to placebo. In subjects with diabetes taking metformin, weight increased in the GSK457-treated group [adjusted mean % increase from baseline: 1.26% (95% CI: -0.24, 2.75)], and mean glucose and HbA1c were decreased slightly compared to placebo [adjusted mean glucose change from baseline: -1.22 mmol/L (95% CI: -2.45, 0.01); adjusted mean HbA1c change from baseline: -0.219% (95% CI: -0.910, 0.472)]. CONCLUSIONS: Our data demonstrate remarkable effects of GSK457 in rodent models of obesity and diabetes, but a marked lack of translation to humans. Caution should be exercised with nutritional agents when predicting human efficacy from rodent models of obesity and diabetes. TRIAL REGISTRATION: ClinicalTrials.gov NCT01725126.
Subject(s)
Biological Factors/pharmacology , Blood Glucose/drug effects , Body Weight/drug effects , Diabetes Mellitus, Type 2/blood , Diabetes Mellitus, Type 2/physiopathology , Adolescent , Adult , Aged , Animals , Diabetes Mellitus, Type 2/metabolism , Female , Glucagon-Like Peptide 1/metabolism , Healthy Volunteers , Humans , Hypoglycemic Agents/pharmacology , Liraglutide/pharmacology , Male , Metformin/pharmacology , Mice , Mice, Inbred C57BL , Middle Aged , Weight Loss/drug effects , Young AdultABSTRACT
The gastrointestinal tract microbiome has been suggested as a potential therapeutic target for metabolic diseases such as obesity and Type 2 diabetes mellitus (T2DM). However, the relationship between changes in microbial communities and metabolic disease-phenotypes are still poorly understood. In this study, we used antibiotics with markedly different antibacterial spectra to modulate the gut microbiome in a diet-induced obesity mouse model and then measured relevant biochemical, hormonal and phenotypic biomarkers of obesity and T2DM. Mice fed a high-fat diet were treated with either ceftazidime (a primarily anti-Gram negative bacteria antibiotic) or vancomycin (mainly anti-Gram positive bacteria activity) in an escalating three-dose regimen. We also dosed animals with a well-known prebiotic weight-loss supplement, 10% oligofructose saccharide (10% OFS). Vancomycin treated mice showed little weight change and no improvement in glycemic control while ceftazidime and 10% OFS treatments induced significant weight loss. However, only ceftazidime showed significant, dose dependent improvement in key metabolic variables including glucose, insulin, protein tyrosine tyrosine (PYY) and glucagon-like peptide-1 (GLP-1). Subsequently, we confirmed the positive hyperglycemic control effects of ceftazidime in the Zucker diabetic fatty (ZDF) rat model. Metagenomic DNA sequencing of bacterial 16S rRNA gene regions V1-V3 showed that the microbiomes of ceftazidime dosed mice and rats were enriched for the phylum Firmicutes while 10% OFS treated mice had a greater abundance of Bacteroidetes. We show that specific changes in microbial community composition are associated with obesity and glycemic control phenotypes. More broadly, our study suggests that in vivo modulation of the microbiome warrants further investigation as a potential therapeutic strategy for metabolic diseases.
Subject(s)
Anti-Bacterial Agents/pharmacology , Diabetes Mellitus, Type 2/microbiology , Gastrointestinal Microbiome/drug effects , Obesity/microbiology , Animals , Ceftazidime/pharmacology , Diet/adverse effects , Disease Models, Animal , Male , Mice , Obesity/etiology , Phenotype , Prebiotics , RatsABSTRACT
µ-Opioid receptor (MOR) agonism induces palatable food consumption principally through modulation of the rewarding properties of food. N-{[3,5-difluoro-3'-(1H-1,2,4-triazol-3-yl)-4-biphenylyl]methyl}-2,3-dihydro-1H-inden-2-amine (GSK1521498) is a novel opioid receptor inverse agonist that, on the basis of in vitro affinity assays, is greater than 10- or 50-fold selective for human or rat MOR, respectively, compared with κ-opioid receptors (KOR) and δ-opioid receptors (DOR). Likewise, preferential MOR occupancy versus KOR and DOR was observed by autoradiography in brain slices from Long Evans rats dosed orally with the drug. GSK1521498 suppressed nocturnal food consumption of standard or palatable chow in lean and diet-induced obese (DIO) Long Evans rats. Both the dose-response relationship and time course of efficacy in lean rats fed palatable chow correlated with µ receptor occupancy and the plasma concentration profile of the drug. Chronic oral administration of GSK1521498 induced body weight loss in DIO rats, which comprised fat mass reduction. The reduction in body weight was equivalent to the cumulative reduction in food consumption; thus, the effect of GSK1521498 on body weight is related to inhibition of food consumption. GSK1521498 suppressed the preference for sucrose-containing solutions in lean rats. In operant response models also using lean rats, GSK1521498 reduced the reinforcement efficacy of palatable food reward and enhanced satiety. In conclusion, GSK1521498 is a potent, MOR-selective inverse agonist that modulates the hedonic aspects of ingestion and, therefore, could represent a pharmacological treatment for obesity and binge-eating disorders.
Subject(s)
Anti-Obesity Agents/pharmacology , Drinking Behavior/drug effects , Feeding Behavior/drug effects , Indans/pharmacology , Receptors, Opioid, mu/agonists , Triazoles/pharmacology , Adiposity/drug effects , Animals , Anti-Obesity Agents/pharmacokinetics , Body Weight/drug effects , Brain/metabolism , Calibration , Conditioning, Operant/drug effects , Data Interpretation, Statistical , Food Preferences/drug effects , Guanosine 5'-O-(3-Thiotriphosphate)/pharmacology , Indans/pharmacokinetics , Injections, Intravenous , Male , Rats , Rats, Sprague-Dawley , Receptors, Opioid, delta/metabolism , Receptors, Opioid, kappa/metabolism , Satiety Response/drug effects , Triazoles/pharmacokinetics , Weight Loss/drug effectsABSTRACT
Key binding interactions of the anthranilimide based glycogen phosphorylase a (GPa) inhibitor 2 from X-ray crystallography studies are described. This series of compounds bind to the AMP site of GP. Using the binding information the core and the phenyl urea moieties were optimized. This work culminated in the identification of compounds with single nanomolar potency as well as in vivo efficacy in a diabetic model.
Subject(s)
Diabetes Mellitus, Type 2/drug therapy , Glycogen Phosphorylase/antagonists & inhibitors , Hypoglycemic Agents/chemical synthesis , ortho-Aminobenzoates/chemical synthesis , ortho-Aminobenzoates/pharmacology , Animals , Blood Glucose/analysis , Combinatorial Chemistry Techniques , Crystallography, X-Ray , Disease Models, Animal , Hypoglycemic Agents/blood , Hypoglycemic Agents/chemistry , Hypoglycemic Agents/pharmacology , Mice , Molecular Conformation , Molecular Structure , Structure-Activity Relationship , Urea/pharmacology , ortho-Aminobenzoates/blood , ortho-Aminobenzoates/chemistryABSTRACT
A series of amino acid anthranilamide derivatives identified from a high-throughput screening campaign as novel, potent, and glucose-sensitive inhibitors of human liver glycogen phosphorylase a are described. A solid-phase synthesis using Wang resin was also developed which provided efficient access to a variety of analogues, and resulted in the identification of key structure-activity relationships, and the discovery of a potent exemplar (IC(50)=80 nM). The SAR scope, synthetic strategy, and in vitro results for this series are presented herein.
Subject(s)
Glycogen Phosphorylase, Liver Form/antagonists & inhibitors , ortho-Aminobenzoates/chemistry , Amino Acids/chemistry , Animals , Chemistry, Pharmaceutical/methods , Drug Design , Glycogen Phosphorylase, Liver Form/chemistry , Humans , Inhibitory Concentration 50 , Liver/enzymology , Microsomes, Liver/enzymology , Models, Chemical , Rats , Structure-Activity Relationship , Urea/chemistry , ortho-Aminobenzoates/pharmacologyABSTRACT
A set of novel heterocyclic pyrimidyl hydrazones has been synthesized as inhibitors of glycogen synthase kinase-3 (GSK-3) with the most active exhibiting low nanomolar activity. Quantum mechanical calculations indicate that of the conformational factors that could determine binding affinity, the planarity of the phenyl ring in relation to the central core and the conformation of the hydrazone chain may be the most influential.
Subject(s)
Enzyme Inhibitors/chemical synthesis , Enzyme Inhibitors/pharmacology , Glycogen Synthase Kinase 3/antagonists & inhibitors , Heterocyclic Compounds/chemical synthesis , Heterocyclic Compounds/pharmacology , Hydrazines/chemical synthesis , Hydrazines/pharmacology , Inhibitory Concentration 50 , Models, Chemical , StereoisomerismABSTRACT
Glycogen synthase kinase 3 regulates glycogen synthase, the rate-determining enzyme for glycogen synthesis. Liver and muscle glycogen synthesis is defective in type 2 diabetics, resulting in elevated plasma glucose levels. Inhibition of GSK-3 could potentially be an effective method to control plasma glucose levels in type 2 diabetics. Structure-activity studies on a N-phenyl-4-pyrazolo[1,5-b]pyridazin-3-ylpyrimidin-2-amine series have led to the identification of potent and selective compounds with good cellular efficacy. Molecular modeling studies have given insights into the mode of binding of these inhibitors. Since the initial leads were also potent inhibitors of CDK-2/CDK-4, an extensive SAR was performed at various positions of the pyrazolo[1,5-b]pyridazin core to afford potent GSK-3 inhibitors that were highly selective over CDK-2. In addition, these inhibitors also exhibited very good cell efficacy and functional response. A representative example was shown to have good oral exposure levels, extending their utility in an in vivo setting. These inhibitors provide a viable lead series in the discovery of new therapies for the treatment of type 2 diabetes.
Subject(s)
Amines/chemistry , Enzyme Inhibitors/chemistry , Enzyme Inhibitors/pharmacology , Glycogen Synthase Kinase 3/antagonists & inhibitors , Pyridazines/chemistry , Pyridazines/pharmacology , Animals , Binding Sites , Cell Line , Enzyme Inhibitors/chemical synthesis , Glycogen Synthase Kinase 3/metabolism , Humans , Inhibitory Concentration 50 , Models, Molecular , Molecular Structure , Protein Structure, Tertiary , Pyridazines/chemical synthesis , Rats , Structure-Activity RelationshipABSTRACT
A series of [1-aryl-1H-pyrazolo[3,4-d]pyrimidin-4-yl]arylhydrazones were discovered as novel inhibitors glycogen synthase kinase-3 (GSK-3). Based on initial modeling a detailed SAR was constructed. Modification of the interior binding aryl ring (Ar(1)) determined this to be a tight binding region with little room for modification. As predicted from the model, a large variety of modifications could be incorporated into the hydrazone aryl ring. This work led to GSK-3 inhibitors in the low nano-molar range.
Subject(s)
Enzyme Inhibitors/pharmacology , Glycogen Synthase Kinase 3/antagonists & inhibitors , Pyrazoles/chemistry , Pyrimidines/pharmacology , Enzyme Inhibitors/chemistry , Models, Molecular , Pyrimidines/chemistryABSTRACT
A novel series of [1-(1H-benzimidazol-7-yl)-1H-pyrazolo[3,4-d]pyrimidin-4-yl] arylhydrazones was synthesized and shown to potently inhibit glycogen synthase kinase-3 (GSK-3). In light of detailed structure-activity relationships and structural knowledge of the GSK-3 binding pocket, a benzimidazole substituent was incorporated onto the pyrazolopyrimidine core resulting in improved potency over previous analogs. More importantly, these derivatives show low nanomolar efficacy for stimulating glycogen synthesis in vitro and therefore may be useful in the treatment of type 2 diabetes mellitus.