Candidate For Treatment Of Obesity Research Articles

211-OR: Dual Amylin and Calcitonin Receptor Agonists Increase Mitochondrial Respiratory Capacity in Adipose Tissues of Obese Rat

Dual amylin and calcitonin receptor agonists (DACRAs) are potential therapeutic candidates for treatment of obesity. Preclinical studies have shown favorable effects of DACRAs on appetite regulation contributing to a reduction in body weight. Interestingly, the DACRA-induced effects on weight loss are superior to the effects of a suppressed food intake, suggesting an effect on energy expenditure potentially by targeting the mitochondria. We investigated the effects of long-term treatment with a class of DACRAs, namely KBPs, on body weight, food intake and mitochondrial respiratory capacity (MRC) in Sprague-Dawley rats fed a high-fat diet and treated s.c. with KBPs for 8 weeks. Moreover, a pair-fed (PF) group was used to examine food intake-independent effects of KBPs on MRC. At study end, MRC was analyzed in perirenal (pAT) and inguinal (iAT) adipose tissue using high resolution respirometry. Expectedly, KBP treatment significantly reduced body weight compared to PF and vehicle. PF was successfully KBP-matched in terms of accumulated food intake and the food intake was significantly lower than that of vehicle-treated rats. Coupled and uncoupled MRC supported by complex I+II substrates and fatty acids were significantly greater in iAT and pAT after KBP treatment indicating effects on both carbohydrate and lipid metabolism. Additionally, an increased oligomycin-induced leak-respiration was found to be independent of food intake in iAT. Further analysis will shed light on whether these changes in MRC are a result of an increased mitochondrial content or of the respiratory capacity of each mitochondrion. In conclusion, treatment with KBPs in obese rats is associated with an increased MRC in pAT and iAT and elicits effects additional to those obtained by diet-induced weight loss. This highlights DACRAs’ potential as anti-obesity agents with possible benefits on energy expenditure as a contributing cause to the DACRA-induced weight loss. Disclosure E.A.Petersen: Employee; Nordic Bioscience A/S. I.Blom: None. S.A.Melander: None. M.A.Karsdal: Speaker's Bureau; Pfizer Inc. S.Larsen: None. K.Henriksen: Employee; Nordic Bioscience A/S, Stock/Shareholder; Nordic Bioscience A/S. A.T.Larsen: Employee; Nordic Bioscience A/S. Funding Innovation Fund Denmark

Thermo-Responsive self-assembly of a dual glucagon-like peptide and glucagon receptor agonist

The human peptide hormone Oxyntomodulin (Oxm) is known to induce satiety, increase energy expenditure, and control blood glucose in humans, making it a promising candidate for treatment of obesity and/or type 2 diabetes mellitus. However, a pharmaceutical exploitation has thus far been impeded by fast in vivo clearance and the molecule‘s sensitivity to half-life extending structural modifications. We recently showed that Oxm self-assembles into amyloid-like nanofibrils that continuously release active, soluble Oxm in a peptide-deprived environment. S.c. injected Oxm nanofibrils extended plasma exposure from a few hours to five days in rodents, compared to s.c. applied soluble Oxm. Here we show that Oxm fibril elongation kinetics and thermodynamics display a uniquely low temperature optimum compared to previously reported amyloid-like peptide and protein assemblies. Elongation rate is optimal at room temperature, with association rates 2–3 times higher at 25 °C than at ≥37 °C or ≤20 °C. We deduce from a combination of Cryo electron microscopy and spectroscopic methods that Oxm fibrils have a double-layered, triangular cross-section composed of arch-shaped monomers. We suggest a thermodynamic model that links the necessary molecular rearrangements during fibrillation and peptide release to the unique temperature effects in Oxm self-assembly and disassembly.

Syringin: A Phenylpropanoid Glycoside Compound in Cirsium brevicaule A. GRAY Root Modulates Adipogenesis.

Cirsium brevicaule A. GRAY is a wild perennial herb, and its roots (CbR) have traditionally been used as both food and medicine on the Japanese islands of Okinawa and Amami. The present study evaluated the antiadipogenic effect of CbR using mouse embryonic fibroblast cell line 3T3-L1 from JCRB cell bank. Dried CbR powder was serially extracted with solvents of various polarities, and these crude extracts were tested for antiadipogenic activity. Treatment with the methanol extract of CbR showed a significant suppression of lipid accumulation in 3T3-L1 cells. Methanol extract of CbR was then fractionated and subjected to further activity analyses. The phenylpropanoid glycosidic molecule syringin was identified as an active compound. Syringin dose dependently suppressed lipid accumulation of 3T3-L1 cells without cytotoxicity, and significantly reduced the expressions of peroxisome proliferator-activated receptor gamma, the master regulator of adipogenesis, and other differentiation markers. It was demonstrated that syringin effectively enhanced the phosphorylation of the AMP-activated protein kinase and acetyl-CoA carboxylase. These results indicate that syringin attenuates adipocyte differentiation, adipogenesis, and promotes lipid metabolism; thus, syringin may potentially serve as a therapeutic candidate for treatment of obesity.

Discovery and preclinical efficacy of HSG4112, a synthetic structural analog of glabridin, for the treatment of obesity

BackgroundHSG4112 is a clinical-stage drug candidate for the treatment of obesity. Here, we report its discovery and preclinical efficacy.MethodsIn high-fat diet (HFD)-induced obese male C57BL/6J mice, we tested the weight loss effect of synthetic compounds derived from a structure–activity relationship (SAR) study of glabridin, a natural compound known to reduce body weight and influence energy homeostasis. After selecting HSG4112 as our optimized compound from this discovery method, we characterized its pharmacological effects on parameters related to obesity through in vivo metabolic and biochemical measurements, histology and gene expression analysis, and indirect calorimetry.ResultsThrough the SAR study, we identified four novel components of glabridin pertinent for its anti-obesity activity, and found that HSG4112, an optimized structural analog of glabridin, markedly supersedes glabridin in weight reduction efficacy and chemical stability. Six-week administration of HSG4112 to HFD-induced obese mice led to dose-dependent normalization of obesity-related parameters, including body weight, muscle and adipose tissue weight, adipocyte size, and serum leptin/insulin/glucose levels. The weight reduction induced by HSG4112 was partially mediated by decreased food intake and mainly mediated by increased energy expenditure, with no change in physical activity. Accordingly, the pattern of transcriptional changes was aligned with increased energy expenditure in the liver and muscles. Following significant body weight reduction, robust amelioration of histopathology and blood markers of fatty liver were also observed.ConclusionsOur study demonstrates the key chemical components of glabridin pertinent to its weight loss effects and suggests HSG4112 as a promising novel drug candidate for the pharmacological treatment of obesity.

Inhibition of PTP1B disrupts cell\u2013cell adhesion and induces anoikis in breast epithelial cells

Protein tyrosine phosphatase 1B (PTP1B) is a well-known inhibitor of insulin signaling pathways and inhibitors against PTP1B are being developed as promising drug candidates for treatment of obesity. PTP1B has also been linked to breast cancer both as a tumor suppressor and as an oncogene. Furthermore, PTP1B has been shown to be a regulator of cell adhesion and migration in normal and cancer cells. In this study, we analyzed the PTP1B expression in normal breast tissue, primary breast cells and the breast epithelial cell line D492. In normal breast tissue and primary breast cells, PTP1B is widely expressed in both epithelial and stromal cells, with highest expression in myoepithelial cells and fibroblasts. PTP1B is widely expressed in branching structures generated by D492 when cultured in 3D reconstituted basement membrane (3D rBM). Inhibition of PTP1B in D492 and another mammary epithelial cell line HMLE resulted in reduced cell proliferation and induction of anoikis. These changes were seen when cells were cultured both in monolayer and in 3D rBM. PTP1B inhibition affected cell attachment, expression of cell adhesion proteins and actin polymerization. Moreover, epithelial to mesenchymal transition (EMT) sensitized cells to PTP1B inhibition. A mesenchymal sublines of D492 and HMLE (D492M and HMLEmes) were more sensitive to PTP1B inhibition than D492 and HMLE. Reversion of D492M to an epithelial state using miR-200c-141 restored resistance to detachment induced by PTP1B inhibition. In conclusion, we have shown that PTP1B is widely expressed in the human breast gland with highest expression in myoepithelial cells and fibroblasts. Inhibition of PTP1B in D492 and HMLE affects cell–cell adhesion and induces anoikis-like effects. Finally, cells with an EMT phenotype are more sensitive to PTP1B inhibitors making PTP1B a potential candidate for further studies as a target for drug development in cancer involving the EMT phenotype.

Intranasal delivery of N-terminal modified leptin-pluronic conjugate for treatment of obesity

Leptin is an adipocyte-secreted hormone that is delivered via a specific transport system across the blood-brain barrier (BBB) to the brain where it acts on the hypothalamus receptors to control appetite and thermogenesis. Peripheral resistance to leptin due to its impaired brain delivery prevents therapeutic use of leptin in overweight and moderately obese patients. To address this problem, we modified the N-terminal amine of leptin with Pluronic P85 (LepNP85) and administered this conjugate intranasally using the nose-to-brain (INB) route to bypass the BBB. We compared this conjugate with the native leptin, the N-terminal leptin conjugate with poly(ethylene glycol) (LepNPEG5K), and two conjugates of leptin with Pluronic P85 attached randomly to the lysine amino groups of the hormone. Compared to the random conjugates of leptin with P85, LepNP85 has shown higher affinity upon binding with the leptin receptor, and similarly to native hormone activated hypothalamus receptors after direct injection into brain. After INB delivery, LepNP85 conjugate was transported to the brain and accumulated in the hypothalamus and hippocampus to a greater extent than the native leptin and LepNPEG5K and activated leptin receptors in hypothalamus at lower dose than native leptin. Our work suggests that LepNP85 can access the brain directly after INB delivery and confirms our hypothesis that the improvement in brain accumulation of this conjugate is due to its enhanced brain absorption. In conclusion, the LepNP85 with optimized conjugation chemistry is a promising candidate for treatment of obesity.

Neuromedin U inhibits food intake partly by inhibiting gastric emptying

Neuromedin U (NMU) is a gut-brain peptide, implicated in energy and glucose homeostasis via the peripherally expressed NMU receptor 1 (NMUR1) and the central NMUR2. We investigated the effects of a lipidated NMU analog on gastric emptying (GE), glucose homeostasis and food intake to evaluate the use of a NMU analog as drug candidate for treatment of obesity and diabetes. Finally mRNA expression of NMU and NMUR1 in the gut and NMUR2 in the hypothalamus was investigated using a novel chromogen-based in situ hybridization (ISH) assay. Effects on food intake (6 and 18h post dosing) were addressed in both mice and rats. The effects on GE and glycaemic control were assessed in mice, immediately after the first dose and after seven days of bidaily (BID) dosing. The lipidated NMU analog exerted robust reductions in GE and food intake in mice and improved glycaemic control when measured immediately after the first dose. No effects were observed after seven days BID. In rats, the analog induced only a minor effect on food intake. NMU mRNA was detected in the enteric nervous system throughout the gut, whereas NMUR1 was confined to the lamina propria. NMUR2 was detected in the paraventricular (PVN) and arcuate nuclei (ARC) in mice, with a reduced expression in ARC in rats. In summary, the anorectic effect of the lipidated NMU is partly mediated by a decrease in gastric emptying which is subject to tachyphylaxis after continuous dosing. Susceptibility to NMU appears to be species specific.

Regulation of Gastric Nesfatin-1/NUCB2

Originally identified in the hypothalamus as a satiety factor, recent studies provide evidence that nefatin-1/NUCB2 is a gutbrain peptide with a broader array of actions. Detection of abundant nesfatin-1/NUCB2 in gastric X/A like endocrine cells, which also produce the orexigenic hormone ghrelin, indicates that gastric mucosa may be one of the predominant sources of nesfatin-1/NUCB2. Functional studies have revealed significant effects of nefatin-1 on inhibition of feeding behavior and on glucose homeostasis. These metabolic functions make nesfatin-1/NUCB2 a novel candidate for treatment of obesity and diabetes. However, deficiencies in our understanding of nesfatin-1/NUCB2 receptor pose a significant hurdle for therapies that target its action. Defining novel pathways to alter the production of nesfatin-1/NUCB2 would shift therapeutic focus to gastric targets. A necessary precondition is improved understanding of the mechanisms by which nesfatin-1/NUCB2 is synthesized and secreted by gastric X/A like cells. Recent studies provide evidence that mTOR is a critical regulatory molecule in these endocrine cells and that its activity is linked to the production of ghrelin and nesfatin- 1/NUCB2. These findings suggest that gastric mTOR is involved in the regulation of food intake and overall energy metabolism through modulation of ghrelin and nesfatin-1/NUCB2. In this review, we first summarize current advances in the relationship between organism energy status and nesfatin-1/NUCB2 levels, and then discuss the novel finding on mTOR as the gastric fuel sensor and its role in the regulation of nesfatin-1/NUCB2 expression.

Utilidad de los fármacos antiobesidad en la diabetes mellitus tipo 2

Both obesity and diabetes mellitus type 2 are major health problems in our society that often go together, being in most cases the second consequence of the first. Obesity drugs may be useful in diabetic patients, since important weight loss is associated with a significant improvement of glycemic control, as well as other metabolic parameters. The objective of this manuscript is to offer an analysis of the drugs currently used for the treatment of obesity and that may be useful for obese patients with type 2 diabetes. We will analyze different therapeutic perspectives and review the limited armamentarium currently available to approach the serious problem of the obesity in the context of the diabetic patient. Furthermore, anti-obesity drugs currently in phase III of development will be presented as possible candidates for treatment of obesity and diabetes.

The acute and subchronic effects of a brain-penetrating, neurotensin-1 receptor agonist on feeding, body weight and temperature

The neurotensin-1 (NT1) receptor has been implicated in mediating a number of important neurotensin effects. We have found that PD149163, a selective, brain-penetrating, NT1 receptor agonist, produces a number of therapeutic-like preclinical effects after peripheral administration including pro-cognitive, antipsychotic and anxiolytic effects. In this study, we investigated PD149163's effect on food intake and thermal regulation, two physiological processes thought to be mediated by NT1 receptors. Brown Norway rats and leptin-deficient mice (ob/ob) mice were administered subcutaneous PD149163 (0, 0.1, 0.25, or 1 mg/kg) for ten consecutive days. Weight and 24-h food intake were measured in mice and rats and core body temperature was also measured in rats. PD149163 significantly decreased food intake in rats and ob/ob mice and no tolerance was demonstrated to this effect over the course of the study. PD149163-treated animals exhibited weight loss compared to saline-treated animals. PD149163 produced hypothermia as expected but this effect did show tolerance over the course of the study, unlike feeding. The results suggest that NT1 receptor agonists are candidates for treatment of obesity and that somewhat different mechanisms are involved in NT1-induced feeding regulation and temperature regulation.

Serum Levels Of Human Angiopoietin-related Growth Factor In Human Body

The angiopoietin-related growth factor (AGF) is a novel hepatokine that increases energy expenditure and insulin sensitivity. Animal models demonstrated AGF as a candidate for treatment of obesity and diabetes; however, no human study has been reported. PURPOSE: To determine the serum levels of AGF in human body and the correlations with biochemical markers or body measurement data. METHODS: From Korean Rural Genomic Cohort (KRGC) study, 195 subjects were enrolled (age 56.1 ± 8.015, 98 were male, 97 were female). Sandwich ELISA was performed to measure the serum levels of AGF; biochemical markers and body measurement data collected in KRGC study were used for correlation analysis. RESULTS: Serum AGF levels were significantly increased in the people with metabolic syndrome (328.48±16.28ng/mL) compared to those of healthy people (276.65±10.72ng/mL). Among the components of metabolic syndrome, people with high waist circumferences showed significant higher serum AGF than in control group. Correlations with significance were observed between serum AGF and weight, waist, hip, body mass index, total body fat, visceral fat, LDL, AST, ALT, fasting insulin, or 1 hour insulin level of oral glucose tolerance test(OGTT) in positive, and age in negative. CONCLUSIONS: Serum levels of human AGF were diametrically opposed to hypotheses from animal models. Further study is needed to investigate the AGF resistance. This is the first report of serum levels of AGF in human.

Efficiency Biliopancreatic bypass surgery in bulimia nervosa

A clinical significance in the treatment of bulimia nervosa patients with morbid obesity had already been raised [10, 13], but we did not find publications on the effectiveness of bariatric surgery in these cases. There is also information about the possibility of applying the operation bilio-pancreatic bypass, effective in patients with morbid obesity with uncontrolled eating behavior for the treatment of patients with anorexia BILIM not suffering from morbid obesity. In this article the data of clinical observation of a small sample of patients. As a result, the treatment of these patients found that severe nervous BILIM can be seen as a latent form of morbid obesity. The choice of treatment should depend not only on the initial body weight of the patient, but also on the severity of the nervous BILIM. Unsuccessful attempts at organized-balanced, conservative treatment of patients with severe bulimia nervosa may be considered a variant of surgical treatment, while bilio-pancreatic bypass surgery is considered as the most preferred operation, compared with the installation of the gastric balloon and others. All candidates for surgical treatment of obesity must identify clinical signs of bulimia nervosa, as this may influence the choice of method of operation. Further study of the role of hyperinsulinemia, secretion of ghrelin, leptin, intestinal peptide may contribute to the elucidation of the true causes of bulimia nervosa, probably has a similar origin with morbid obesity.

Practical Synthesis of NPY Antagonist Drug Candidates for Treatment of Obesity

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.

Genotoxicity of 2-(3-Chlorobenzyloxy)-6-(piperazinyl)pyrazine, a Novel 5-Hydroxytryptamine2c Receptor Agonist for the Treatment of Obesity: Role of Metabolic Activation

2-(3-Chlorobenzyloxy)-6-(piperazin-1-yl)pyrazine (3) is a potent and selective 5-HT(2C) agonist that exhibits dose-dependent inhibition of food intake and reduction in body weight in rats, making it an attractive candidate for treatment of obesity. However, examination of the genotoxicity potential of 3 in the Salmonella Ames assay using tester strains TA98, TA100, TA1535, and TA1537 revealed a metabolism (rat S9/NADPH)- and dose-dependent increase of reverse mutations in strains TA100 and TA1537. The increase in reverse mutations was attenuated upon coincubation with methoxylamine and glutathione. The irreversible and concentration-dependent incorporation of radioactivity in calf thymus DNA after incubations with [14C]3 in the presence of rat S9/NADPH suggested that 3 was bioactivated to a reactive intermediate that covalently bound DNA. In vitro metabolism studies on 3 with rat S9/NADPH in the presence of methoxylamine and cyanide led to the detection of amine and cyano conjugates of 3. The mass spectrum of the amine conjugate was consistent with condensation of amine with an aldehyde metabolite derived from hydroxylation of the secondary piperazine nitrogen-alpha-carbon bond. The mass spectrum of the cyano conjugate suggested a bioactivation pathway involving N-hydroxylation of the secondary piperazine nitrogen followed by two-electron oxidation to generate an electrophilic nitrone, which reacted with cyanide. The 3-chlorobenzyl motif in 3 was also bioactivated via initial aromatic ring hydroxylation followed by elimination to a quinone-methide species that reacted with glutathione or with the secondary piperazine ring nitrogen in 3 and its monohydroxylated metabolite(s). The metabolism studies described herein provide a mechanistic basis for the mutagenicity of 3.

Cannabinoid-1 Receptor Antagonist, Rimonabant, for Management of Obesity and Related Risks

The prevalence of obesity has risen substantially during the past 25 years in the United States and most developed countries, with a related increase in type 2 diabetes mellitus.1,2 Almost one third of the adult US population is considered to be obese (body mass index [BMI] ≥30), and 1 in 20 is extremely obese (BMI ≥40).3 Nearly 17% of children and adolescents are overweight in the United States.3 Obesity is associated with increased risk for type 2 diabetes mellitus, coronary heart disease (CHD), hypertension, obstructive sleep apnea, and cancer, higher overall mortality rate,4–6 and decreased longevity.7,8 Extreme obesity can truncate life expectancy in young adults by 5 to 20 years.8 Accordingly, the expected benefits of weight reduction for obese individuals are profound. Weight loss of 5% to 10% generally lessens many health risks, including cardiovascular risks, although such improvements are most notably demonstrable in studies specifically conducted in high-risk populations, and the benefits are presumed to be greater when healthier weight is maintained for long periods.9,10 In overweight and obese individuals, weight loss achieved with most interventions over 1 to 2 years generally leads to improvements in blood pressure (BP), glycemic measures, and triglycerides (TGs). Improvements in total cholesterol, high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C) have been reported in studies using dietary interventions combined with exercise. When weight loss is achieved primarily via pharmacological interventions, these benefits have not occurred quite so consistently.11 Reduced caloric intake and increased physical activity are generally accepted as the foundations of any approach directed at weight reduction, but these lifestyle interventions do not appear to provide long-lasting success for obese individuals wishing to lose weight. About half of the weight lost with the help of lifestyle interventions is regained at 1 year; after …