In humans, the combination of all sex-specific genetic, epigenetic, and hormonal influences of biologic sex produces different in vivo environments for male and female cells. We dissect how these influences of sex modify the pharmacokinetics and pharmacodynamics of multiple drugs and provide examples for common drugs acting on specific organ systems. We also discuss how gender of physicians and patients may influence the therapeutic response to drugs. We aim to highlight sex as a genetic modifier of the pharmacological response to drugs, which should be considered as a necessary step toward precision medicine that will benefit men and women. Significance Statement This study discusses the influences of biologic sex on the pharmacokinetics and pharmacodynamics of drugs and provides examples for common drugs acting on specific organ systems. This study also discusses how gender of physicians and patients influence the therapeutic response to drugs.
More than one-third of the worldwide population is overweight or obese and therefore at risk of developing type 2 diabetes mellitus. In order to mitigate this pandemic, safer and more potent therapeutics are urgently required. This necessitates the continued use of animal models to discover, validate and optimize novel therapeutics for their safe use in humans. In order to improve the transition from bench to bedside, researchers must not only carefully select the appropriate model but also draw the right conclusions. In this Review, we consolidate the key information on the currently available animal models of obesity and diabetes and highlight the advantages, limitations and important caveats of each of these models.
Background: Like all healthy ecosystems, richness of microbiota species characterizes the GI microbiome in healthy individuals. Conversely, a loss in species diversity is a common finding in several disease states. This biome is flooded with energy in the form of undigested and partially digested foods, and in some cases drugs and dietary supplements. Each microbiotic species in the biome transforms that energy into new molecules, which may signal messages to physiological systems of the host.Scope of review: Dietary choices select substrates for species, providing a competitive advantage over other GI microbiota. The more diverse the diet, the more diverse the microbiome and the more adaptable it will be to perturbations. Unfortunately, dietary diversity has been lost during the past 50 years and dietary choices that exclude food products from animals or plants will narrow the GI microbiome further.Major conclusion: Additional research into expanding gut microbial richness by dietary diversity is likely to expand concepts in healthy nutrition, stimulate discovery of new diagnostics, and open up novel therapeutic possibilities. (C) 2016 The Authors. Published by Elsevier GmbH. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).
OBJECTIVE:Simplification of diets, low in variety but high in energy, contributes to the loss in diversity observed in the obese gastrointestinal (GI) microbiome. A novel GI microbiome modulator (GIMM) as a dietary intervention was developed.METHODS:Mice were fed either an obesogenic diet (ObD) or an ObD containing 15% activated soy pod fiber (ObD-ASPF) for 30 days. The diets were isocaloric and balanced for macronutrient content. ASPF is a novel fiber preparation from whole soy pods that is activated to produce glyceollins.RESULTS:Mice fed ObD-ASPF did not gain body fat. This was associated with decreased absorption of calories (P < 0.05) and increased fecal excretion of triglycerides, which may be attributed to decreased bile acid secretion (P < 0.05). A shift (P < 0.05) in abundances of microbiota in 10 genera was observed. Mice fed ObD-ASPF had elevated plasma concentrations of the anti-inflammatory IL-10 (P < 0.05) and decreased (P < 0.05) plasma concentrations of the neutrophil chemoattractant CXCL1.CONCLUSIONS:A novel dietary intervention derived from soy pods that acts to hinder absorption of dietary fat and glucose in mice was developed. More studies with this GIMM in animal models of diet-induced nonalcoholic fatty liver diseases, type 2 diabetes, and autism are needed.
Pigmented rice contains anthocyanins and proanthocyanidins that are concentrated in the bran layer. In this study, we determined the phenolic, flavonoid, anthocyanin, and proanthocyanidin content of five rice bran (1 brown, 2 red, and 2 purple) extracts. Each bran extract was evaluated for inhibitory effects on α-amylase and α-glucosidase activity, two key glucosidases required for starch digestion in humans. All purple and red bran extracts inhibited α-glucosidase activity, however only the red rice bran extracts inhibited α-amylase activity. Additionally, each bran extract was examined for their ability to stimulate glucose uptake in 3T3-L1 adipocytes, a key function in glucose homeostasis. Basal glucose uptake was increased between 2.3- and 2.7-fold by exposure to the red bran extracts, and between 1.9- and 3.1-fold by exposure to the purple bran extracts. In red rice bran, the highest enzyme inhibition and glucose uptake was observed with a proanthocyanidin-enriched fraction. Both IITA red bran and IAC purple bran increased expression of GLUT1 and GLUT4 mRNA, and genes encoding insulin-signaling pathway proteins.
Acylation of ghrelin is mediated by ghrelin O-acyltansferase (GOAT). Exogenous acylated ghrelin (AG) stimulates growth hormone (GH) and food intake. In non-pregnant (NP) animals, the GOAT-ghrelin-GH axis prevents hypoglycemia caused by caloric restriction (CR). In humans, maternal malnutrition challenges glucose metabolism, which is a key determinant of fetal health. To clarify the role of AG and GH, we compared effects of CR on the GOAT-ghrelin-GH axis in pregnant (P) and NP mice. C57BL/6 wild type (WT) and GOAT knock-out (KO) P and NP mice were freely fed (FF) or subjected to 50 % CR for one week. CR was started in P mice on Day 10.5 after conception. We measured body composition, blood glucose, plasma ghrelin and GH, stomach, hypothalamus and pituitary GOAT and ghrelin expression, and liver glycogen content and Pck1 expression. GOAT and AG were undetectable in KO. In NP mice, CR did not affect blood glucose (-1.3 mmol/l, p > 0.05) in WT but was lowered (-1.8 mmol/l, p < 0.0001) in KO. GH and Pck1 mRNA expression increased in WT but not in KO. In P mice, CR markedly lowered glucose (-2.7 mmol/l; p < 0.0001) in WT and caused fatal hypoglycemia in KO, despite similarly elevated GH in WT and KO mice. KO animals are more prone to hypoglycemia than WT. GH, which is high in P animals, does not prevent hypoglycemia caused by CR during pregnancy. Our data suggest a specific role of AG in the regulation of gluconeogenesis to maintain euglycemia during pregnancy when energy availability is limited.
•We observed a large surge in plasma GH near the end of pregnancy in mice.•We examined if the acylation of ghrelin through GOAT is required for this GH surge.•We used a pregnant mouse model lacking the GOAT gene (GOAT-KO).•GOAT-KO pregnant mice had a similar GH surge as WT pregnant mice.•Perinatal plasma GH surge in pregnant mice is therefore independent of AG.
ObjectiveThe objective of this study was to examine the effects of a gastrointestinal microbiome modulator (GIMM) containing inulin, β-glucan, blueberry anthocyanins, and blueberry polyphenols on metabolic parameters, fecal markers of gut microbiota, and satiety.Design and methodsThirty overweight or obese individuals aged 18 to 70years, were enrolled in a randomized controlled trial. Participants consumed the test product or placebo daily for four weeks. Stool samples were collected and blood was drawn at baseline and week four for assessments of gut microbiota, satiety hormones, glucose control, and lipid measures. Subjective satiety was assessed weekly. Linear models were used to compare differences from baseline to week four.ResultsGIMM consumption improved blood glucose tolerance (p=0.008), and increased satiety (p=0.03). There were no statistically significant differences in insulin sensitivity, fecal markers of gut microbiota, plasma satiety hormones, or serum lipid concentrations between the groups. However, plasma satiety hormones and fecal short chain fatty acid concentrations increased in the test group compared to the placebo.ConclusionsGIMM consumption for four weeks, increases satiety, and improves glucose tolerance possibly through insulin-independent pathways.
Objective: Ghrelin is produced by the stomach, hypothalamus and pituitary. It circulates as acylated ghrelin (AG, which stimulates growth hormone (GH) secretion) and unacylated ghrelin (UAG). Acylation is mediated by the enzyme ghrelin 0-acyltransferase (GOAT). In mice, pregnancy is associated with a marked increase in circulating pituitary GH. We investigated the role of AG and UAG in the surge of plasma GH concentrations in pregnant mice at the end of pregnancy. Design: Using a mouse model generated on a C57BL16 background (wild type, WT) in which the GOAT gene has been deleted (1(0), we measured plasma AG, UAG and GH concentrations and tissue (stomach, pituitary and hypothalamus) preproghrelin and GOAT mRNA in non-pregnant (NP) and pregnant (P), WT and KO mice. Results: GOAT deletion was associated with undetectable concentrations of AG. UAG concentrations were similar in all groups. In both WT and KO animals, mean GH concentrations increased 30 to 50 times during pregnancy. There was a tendency toward lower median GH concentrations in KO (301 ng/mL) compared to WT (428 ng/mL) mice (p = 0.059). Preproghrelin expression was not affected by GOAT deletion or by pregnancy in the stomach. In contrast, pituitary and hypothalamic ghrelin gene expression were lower in KO-NP and KO-P mice compared to their WT counterparts. Conclusion: The complete absence of ghrelin acylation, which is associated with undetectable AG concentrations, does not prevent the marked increase in pituitary GH concentrations observed in pregnant mice, suggesting that AG is not the major mediator of GH secretion during pregnancy. (C) 2015 Elsevier Inc. All rights reserved.
BACKGROUND:The gastrointestinal peptide hormone ghrelin was discovered in 1999 as the endogenous ligand of the growth hormone secretagogue receptor. Increasing evidence supports more complicated and nuanced roles for the hormone, which go beyond the regulation of systemic energy metabolism.SCOPE OF REVIEW:In this review, we discuss the diverse biological functions of ghrelin, the regulation of its secretion, and address questions that still remain 15 years after its discovery.MAJOR CONCLUSIONS:In recent years, ghrelin has been found to have a plethora of central and peripheral actions in distinct areas including learning and memory, gut motility and gastric acid secretion, sleep/wake rhythm, reward seeking behavior, taste sensation and glucose metabolism.
Obesity, 2015 The 33rd Annual Scientific Meeting of the Obesity Society Friday November 6, 1:30-3:30 PM T-OR-2076 A Novel Gastrointestinal Microbiome Modulator (GIMM) from Soy Pods Reduces Absorption of Dietary Fat in Mice Mark Heiman Indianapolis Indiana, Stephen Boué New Orleans LA, Ilana Fortgang New Orleans CA, Ronald Levy Alexandria Louisiana, Deepak Bhatnagar New Orleans Louisiana, Matthew Burow New Orleans LA, George Fahey Urbana IL
Background: Adverse effects of metformin are primarily related to gastrointestinal (GI) intolerance that could limit titration to an efficacious dose or cause discontinuation of the medication. Because some metformin side effects may be attributable to shifts in the GI microbiome, we tested whether a GI microbiome modulator (GIMM) used in combination with metformin would ameliorate the GI symptoms. Methods: A 2-period crossover study design was used with 2 treatment sequences, either placebo in period 1 followed by GIMM in period 2 or vice versa. Study periods lasted for 2 weeks, with a 2-week washout period between. During the first week, type 2 diabetes patients (T2D) who experienced metformin GI intolerance took 500 mg metformin along with their assigned NM504 (GIMM) or placebo treatment with breakfast and with dinner. In the second week, the 10 subjects took 500 mg metformin (t.i.d.), with GIMM or placebo consumed with the first and third daily metformin doses. Subjects were permitted to discontinue metformin dosing if it became intolerable. Results: The combination of metformin and GIMM treatment produced a significantly better tolerance score to metformin than the placebo combination (6.78 ± 0.65 [mean ± SEM] versus 4.45 ± 0.69, P = .0006). Mean fasting glucose levels were significantly ( P < .02) lower with the metformin–GIMM combination (121.3 ± 7.8 mg/dl) than with metformin-placebo (151.9 ± 7.8 mg/dl). Conclusion: Combining a GI microbiome modulator with metformin might allow the greater use of metformin in T2D patients and improve treatment of the disease.
BACKGROUND:Acyl-ghrelin is a 28-amino acid peptide released from the stomach. Ghrelin O-acyl transferase (GOAT) attaches an 8-carbon medium-chain fatty acid (MCFA) (octanoate) to serine 3 of ghrelin. This acylation is necessary for the activity of ghrelin. Animal data suggest that MCFAs provide substrate for GOAT and an increase in nutritional octanoate increases acyl-ghrelin.OBJECTIVES:To address the question of the source of substrate for acylation, we studied whether the decline in ghrelin acylation during fasting is associated with a decline in circulating MCFAs.METHODS:Eight healthy young men (aged 18-28 years, body mass index range, 20.6-26.2 kg/m(2)) had blood drawn every 10 minutes for acyl- and desacyl-ghrelin and every hour for free fatty acids (FFAs) during the last 24 hours of a 61.5-hour fast and during a fed day. FFAs were measured by a highly sensitive liquid chromatography-mass spectroscopy method. Acyl- and desacyl-ghrelin were measured in an in-house assay; the results were published previously. Ghrelin acylation was assessed by the ratio of acyl-ghrelin to total ghrelin.RESULTS:With the exception of MCFAs C8 and C10, all other FFAs, the MCFAs (C6 and C12), and the long-chain fatty acids (C14-C18) significantly increased with fasting (P < .05). There was no significant association between the fold change in ghrelin acylation and circulating FFAs.CONCLUSIONS:These results suggest that changes in circulating MCFAs are not linked to the decline in ghrelin acylation during fasting and support the hypothesis that acylation of ghrelin depends at least partially on the availability of gastroluminal MCFAs or the regulation of GOAT activity.
In addition to its orexigenic properties, ghrelin has been shown to modulate the secretory pattern of pituitary hormones, and it may exert direct effects on peripheral organs such as the gonads and endocrine pancreas. To study possible interactions among ghrelin, glucose homeostasis, and the reproductive system, we investigated 10 obese women with polycystic ovary syndrome (OB-PCOS) in comparison with 10 age-and body mass index-matched obese subjects (OB). Plasma levels of insulin, glucose, androgens, and ghrelin were measured at baseline condition and after 7 months of therapy (hypocaloric diet + metformin or placebo). Plasma ghrelin levels were lower in OB-PCOS than in OB (P < 0.05). A strong negative correlation between ghrelin and androstenedione levels was found in both populations at baseline (OB-PCOS: P < 0.01; OB: P < 0.001) and after therapy (OB-PCOS: P < 0.01; OB: P < 0.05), whereas no correlation was found between ghrelin and other androgens. In both groups, the markers of insulin resistance in fasting and stimulated conditions (glucose/insulin ratio, homeostasis model insulin resistance index, homeostasis model applied to the oral glucose tolerance test) demonstrated decreased insulin sensitivity. However, a negative correlation between plasma ghrelin and all these markers was observed only in the OB-PCOS group (P < 0.05). Accordingly, a negative correlation between ghrelin variation and treatment-induced changes of the glucose/insulin ratio, HOMA-R, and HOMA(OGTT) was observed only in the OB-PCOS group (P < 0.05). In conclusion, OB-PCOS women have lower ghrelin levels than those expected based on the presence of obesity. Only in OB-PCOS, ghrelin negatively correlates with insulin sensitivity. In addition, regardless of the presence of PCOS, a marked negative correlation exists between ghrelin and androstenedione levels, suggestive of an interaction between ghrelin and steroid synthesis or action.
Soy glyceollins, induced during stress, have been shown to inhibit cancer cell growth in vitro and in vivo. In the present study, we used prediabetic rats to examine the glyceollins effect on blood glucose. During an oral glucose tolerance test (OGTT), the blood glucose excursion was significantly decreased in the rats treated with oral administration of either 30 or 90 mg/kg glyceollins. Plasma analysis demonstrated that glyceollins are absorbed after oral administration, and duration of exposure extends from 20 min to at least 4 h postadministration. Exposure of 3T3-L1 adipocytes to glyceollins significantly increased both insulin-stimulated and basal glucose uptake. Basal glucose uptake was increased 1.5-fold by exposure to 5 μM glyceollin in a dose-response manner. Coincubation with insulin significantly stimulated maximal glucose uptake above basal uptake levels and tended to increase glucose uptake beyond the levels of either stimulus alone. On a molecular level, polymerase chain reaction showed significantly increased levels of glucose transporter GLUT4 mRNA in 3T3-L1 adipocytes, especially when the cells were exposed to 5 μM glyceollins for 3 h in vitro. It correlated with elevated protein levels of GLUT4 detected in the 5 μM glyceollin-treated cells. Thus, the simulative effect of the glyceollins on adipocyte glucose uptake was attributed to up-regulation of glucose transporters. These findings indicate potential benefits of the glyceollins as an intervention in prediabetic conditions as well as a treatment for type 1 and type 2 diabetes by increasing both the insulin-mediated and the basal, insulin-independent, glucose uptake by adipocytes.
We report the novel combination of a selective beta adrenoceptor modulator and a norepinephrine-serotonin uptake inhibitor (sibutramine) with potential for the treatment of obesity. The synthesis and characterization of 6-[4-[2-[[(2S)-3-(9H-carbazol-4-yloxy)-2-hydroxypropyl]amino]-2-methylpropyl]phenoxy]pyridine-3-carboxamide (LY377604), a human β3-adrenergic receptor agonist and β1- and β2-adrenergic receptor antagonist with no sympathomimetic activity at the β1- and β2-adrenergic receptors, is reported. Some in vivo data in both rats and humans is presented.