scholarly journals Obesity promotes glucocorticoid-dependent muscle atrophy in male C57BL/6J mice

2020 ◽  
Author(s):  
Laura C. Gunder ◽  
Innocence Harvey ◽  
JeAnna R. Redd ◽  
Carol S. Davis ◽  
Ayat AL-Tamimi ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Mouse Model ◽  
Muscle Atrophy ◽  
Lean Mass ◽  
Muscle Fibers ◽  
Muscle Size ◽  
Type Ii ◽  
Obese Mice ◽  
Diet Induced Obesity ◽  
Synthetic Glucocorticoid

AbstractGlucocorticoids promote muscle atrophy by inducing a class of proteins called atrogenes, resulting in reductions in muscle size and strength. In this work, we evaluated whether a mouse model with pre-existing diet-induced obesity had altered glucocorticoid responsiveness. We observed that all animals treated with the synthetic glucocorticoid dexamethasone had reduced strength, but that obesity exacerbated this effect. These changes were concordant with more pronounced reductions in muscle size, particularly in Type II muscle fibers, and potentiated induction of atrogene expression in the obese mice relative to lean mice. Furthermore, we show that the reductions in lean mass do not fully account for the dexamethasone-induced insulin resistance observed in these mice. Together these data suggest that obesity potentiates glucocorticoid-induced muscle atrophy.

scholarly journals Obesity Augments Glucocorticoid-Dependent Muscle Atrophy in Male C57BL/6J Mice

Biomedicines ◽  
2020 ◽  
Vol 8 (10) ◽  
pp. 420
Author(s):  
Laura C. Gunder ◽  
Innocence Harvey ◽  
JeAnna R. Redd ◽  
Carol S. Davis ◽  
Ayat AL-Tamimi ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Mouse Model ◽  
Muscle Atrophy ◽  
Lean Mass ◽  
Muscle Fibers ◽  
Muscle Size ◽  
Type Ii ◽  
Obese Mice ◽  
Diet Induced Obesity ◽  
Synthetic Glucocorticoid

Glucocorticoids promote muscle atrophy by inducing a class of proteins called atrogenes, resulting in reductions in muscle size and strength. In this work, we evaluated whether a mouse model with pre-existing diet-induced obesity had altered glucocorticoid responsiveness. We observed that all animals treated with the synthetic glucocorticoid dexamethasone had reduced strength, but that obesity exacerbated this effect. These changes were concordant with more pronounced reductions in muscle size, particularly in Type II muscle fibers, and potentiated induction of atrogene expression in the obese mice relative to lean mice. Furthermore, we show that the reductions in lean mass do not fully account for the dexamethasone-induced insulin resistance observed in these mice. Together, these data suggest that obesity potentiates glucocorticoid-induced muscle atrophy.

scholarly journals Obesity Promotes Glucocorticoid-dependent Muscle Atrophy in Male C57BL/6J Mice.

2020 ◽  
Author(s):  
Laura C. Gunder ◽  
Innocence Harvey ◽  
JeAnna R. Redd ◽  
Carol S. Davis ◽  
Ayat AL-Tamimi ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Mouse Model ◽  
Muscle Atrophy ◽  
Lean Mass ◽  
Muscle Fibers ◽  
Muscle Size ◽  
Type Ii ◽  
Obese Mice ◽  
Diet Induced Obesity ◽  
Synthetic Glucocorticoid

Glucocorticoids promote muscle atrophy by inducing a class of proteins called atrogenes, resulting in reductions in muscle size and strength. In this work, we evaluated whether a mouse model with pre-existing diet-induced obesity had altered glucocorticoid responsiveness. We observed that all animals treated with the synthetic glucocorticoid dexamethasone had reduced strength, but that obesity exacerbated this effect. These changes were concordant with more pronounced reductions in muscle size, particularly in Type II muscle fibers, and potentiated induction of atrogene expression in the obese mice relative to lean mice. Furthermore, we show that the reductions in lean mass do not fully account for the dexamethasone-induced insulin resistance observed in these mice. Together these data suggest that obesity potentiates glucocorticoid-induced muscle atrophy.

scholarly journals Increased Tumor Growth in Mice with Diet-Induced Obesity: Impact of Ovarian Hormones

Endocrinology ◽  
2006 ◽  
Vol 147 (12) ◽  
pp. 5826-5834 ◽  
Author(s):  
Shoshana Yakar ◽  
Nomeli P. Nunez ◽  
Patricia Pennisi ◽  
Pnina Brodt ◽  
Hui Sun ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Tumor Growth ◽  
Glucose Intolerance ◽  
Tumor Development ◽  
Tumor Growth Rate ◽  
Obese Mice ◽  
Female Mice ◽  
Diet Induced Obesity ◽  
Body Adiposity ◽  
Obese Female

Obesity increases the risk of many cancers in both males and females. This study describes a link between obesity, obesity-associated metabolic alterations, and the risk of developing cancer in male and female mice. The goal of this study was to evaluate the relationship between gender and obesity and to determine the role of estrogen status in obese females and its effect on tumor growth. We examined the susceptibility of C57BL/6 mice to diet-induced obesity, insulin resistance/glucose intolerance, and tumors. Mice were injected sc with one of two tumorigenic cell lines, Lewis lung carcinoma, or mouse colon 38-adenocarcinoma. Results show that tumor growth rate was increased in obese mice vs. control mice irrespective of the tumor cell type. To investigate the effect of estrogen status on tumor development in obese females, we compared metabolic parameters and tumor growth in ovariectomized (ovx) and intact obese female mice. Obese ovx female mice developed insulin resistance and glucose intolerance similar to that observed in obese males. Our results demonstrate that body adiposity increased in ovx females irrespective of the diet administered and that tumor growth correlated positively with body adiposity. Overall, these data point to more rapid tumor growth in obese mice and suggest that endogenous sex steroids, together with diet, affect adiposity, insulin sensitivity, and tumor growth in female mice.

Black rice anthocyanins alleviate hyperlipidemia, liver steatosis and insulin resistance by regulating lipid metabolism and gut microbiota in obese mice

2021 ◽  
Author(s):  
Haizhao Song ◽  
Xinchun Shen ◽  
Yang Zhou ◽  
Xiaodong Zheng
Keyword(s):  
Insulin Resistance ◽  
Lipid Metabolism ◽  
Gut Microbiota ◽  
Hepatic Steatosis ◽  
High Fat Diet ◽  
Liver Steatosis ◽  
Obese Mice ◽  
Black Rice ◽  
High Fat ◽  
Diet Induced Obesity

Supplementation of black rice anthocyanins (BRAN) alleviated high fat diet-induced obesity, insulin resistance and hepatic steatosis by improvement of lipid metabolism and modification of the gut microbiota.

BCAA Supplementation in Mice with Diet-Induced Obesity Alters the Metabolome Without Impairing Glucose Homeostasis

Endocrinology ◽  
2021 ◽  
Author(s):  
Jennifer Lee ◽  
Archana Vijayakumar ◽  
Phillip J White ◽  
Yuping Xu ◽  
Olga Ilkayeva ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Glucose Homeostasis ◽  
Obese Mice ◽  
High Fat ◽  
Leucine Oxidation ◽  
Insulin Resistant ◽  
Diet Induced Obesity ◽  
Chain Acyl ◽  
Branched Chain ◽  
Relationship Of

Abstract Circulating branched chain amino acid (BCAA) levels are elevated in obese humans and genetically obese rodents. However, the relationship of BCAAs to insulin resistance in diet-induced obese mice, a commonly used model to study glucose homeostasis, is still ill-defined. Here we examined how high-fat high-sucrose (HFHS) or high-fat diet (HFD) feeding, with or without BCAA supplementation in water, alters the metabolome in serum/plasma and tissues in mice and whether raising circulating BCAA levels worsens insulin resistance and glucose intolerance. Neither HFHS nor HFD-feeding raised circulating BCAA levels in insulin-resistant diet-induced obese mice. BCAA supplementation raised circulating BCAA and BCKA levels and C5-OH/C3-DC acylcarnitines (AC) in muscle from HFHS or HFD-fed mice, but did not worsen insulin resistance. A set of short and long-chain acyl CoAs were elevated by diet alone in muscle, liver and WAT, but not increased further by BCAA supplementation. HFD feeding reduced valine and leucine oxidation in WAT but not in muscle. BCAA supplementation markedly increased valine oxidation in muscle from HFD-fed mice while leucine oxidation was unaffected by diet or BCAA treatment. Here we establish an extensive metabolome database showing tissue-specific changes in mice on two different HFDs, with or without BCAA supplementation. We conclude that mildly elevating circulating BCAAs and a subset of ACs by BCAA supplementation does not worsen insulin resistance or glucose tolerance in mice. This work highlights major differences in the effects of BCAAs on glucose homeostasis in diet-induced obese mice versus data reported in obese rats and in humans.

scholarly journals Cashew apple extract inhibition of fat storage and insulin resistance in the diet-induced obesity mouse model

2015 ◽  
Vol 4 ◽  
Author(s):  
Vickram Beejmohun ◽  
Cyril Mignon ◽  
Aude Mazollier ◽  
Marie Peytavy-Izard ◽  
Dominique Pallet ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Body Weight ◽  
Adipose Tissue ◽  
Mouse Model ◽  
Experimental Designs ◽  
Epididymal Adipose Tissue ◽  
Alcoholic Extract ◽  
Fat Storage ◽  
Diet Induced Obesity ◽  
Cashew Apple

AbstractThe cashew apple is an unvalued by-product from the cashew nut industry, of which millions of tonnes are simply discarded globally. Interestingly, however, cashew apple nutrients may have beneficial effects for health even if these are still poorly described. The present study was designed to evaluate the effect of a hydro-alcoholic extract of cashew apple (cashew apple extract; CAE; Cashewin™) on obesity and diabetes, in two experimental designs using the diet-induced obesity (DIO) mouse model. First, in the preventive design, mice were treated orally with the CAE at the dose of 200 mg/kg body weight from the first day under a high-fat diet (HFD) and during 8 weeks thereafter. Second, in the curative design, the animals were first maintained under the HFD for 4 weeks and then treated with the CAE for a further 4 weeks under the same regimen. For both experimental designs, body weight, peri-epididymal adipose tissue, liver weight, food consumption, glycaemia, insulinaemia and insulin resistance were assessed. In both designs, the CAE significantly reduced body-weight gain and fat storage in both the peri-epididymal adipose tissue and the liver for mice under the HFD. This was achieved without modifying their energy consumption. Furthermore, glycaemia, insulinaemia and insulin resistance (homeostasis model assessment-insulin resistance) of the DIO mice were significantly lowered compared with the control group. Thus, a well-designed hydro-alcoholic extract of cashew apple could provide an attractive nutritional food ingredient to help support the management of body weight and associated metabolic parameters such as blood glucose and insulin levels.

scholarly journals ADAM19: A Novel Target for Metabolic Syndrome in Humans and Mice

2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Lakshini Weerasekera ◽  
Caroline Rudnicka ◽  
Qing-Xiang Sang ◽  
Joanne E. Curran ◽  
Matthew P. Johnson ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Metabolic Syndrome ◽  
Adipose Tissue ◽  
Mouse Model ◽  
White Adipose Tissue ◽  
Mononuclear Cells ◽  
Western World ◽  
Diet Induced Obesity ◽  
The Metabolic Syndrome

Obesity is one of the most prevalent metabolic diseases in the Western world and correlates directly with insulin resistance, which may ultimately culminate in type 2 diabetes (T2D). We sought to ascertain whether the human metalloproteinase A Disintegrin and Metalloproteinase 19 (ADAM19) correlates with parameters of the metabolic syndrome in humans and mice. To determine the potential novel role of ADAM19 in the metabolic syndrome, we first conducted microarray studies on peripheral blood mononuclear cells from a well-characterised human cohort. Secondly, we examined the expression of ADAM19 in liver and gonadal white adipose tissue using an in vivo diet induced obesity mouse model. Finally, we investigated the effect of neutralising ADAM19 on diet induced weight gain, insulin resistance in vivo, and liver TNF-α levels. Significantly, we show that, in humans, ADAM19 strongly correlates with parameters of the metabolic syndrome, particularly BMI, relative fat, HOMA-IR, and triglycerides. Furthermore, we identified that ADAM19 expression was markedly increased in the liver and gonadal white adipose tissue of obese and T2D mice. Excitingly, we demonstrate in our diet induced obesity mouse model that neutralising ADAM19 therapy results in weight loss, improves insulin sensitivity, and reduces liver TNF-α levels. Our novel data suggest that ADAM19 is pro-obesogenic and enhances insulin resistance. Therefore, neutralisation of ADAM19 may be a potential therapeutic approach to treat obesity and T2D.

scholarly journals Glucocorticoid-Induced Metabolic Disturbances are Exacerbated in Obesity

2017 ◽  
Author(s):  
Innocence Harvey ◽  
Erin J. Stephenson ◽  
JeAnna R. Redd ◽  
Quynh T. Tran ◽  
Irit Hochberg ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Fatty Liver ◽  
Hepatic Steatosis ◽  
Adult Male ◽  
Synergistic Effects ◽  
Lipolytic Enzyme ◽  
Metabolic Dysfunction ◽  
Obese Mice ◽  
Metabolic Disturbances ◽  
Diet Induced Obesity

AbstractObjective: To determine the effects of glucocorticoid-induced metabolic dysfunction in the presence of diet-induced obesity. Methods: C57BL/6J adult male lean and diet-induced obese mice were given dexamethasone for different durations and levels of hepatic steatosis, insulin resistance and lipolysis were determined. Results: Obese mice given dexamethasone had significant, synergistic effects on insulin resistance and markers of lipolysis, as well as hepatic steatosis. This was associated with synergistic transactivation of the lipolytic enzyme ATGL. Conclusions: The combination of chronically elevated glucocorticoids and obesity leads to exacerbations in metabolic dysfunction. Our findings suggest lipolysis may be a key player in glucocorticoid-induced insulin resistance and fatty liver in individuals with obesity.

scholarly journals Adenovirus transduction to express human ACE2 causes obesity-specific morbidity in mice, impeding studies on the effect of host nutritional status on SARS-CoV-2 pathogenesis.

2021 ◽  
Author(s):  
Pallavi Rai ◽  
Christina Chuong ◽  
Tanya LeRoith ◽  
James W Smyth ◽  
Nisha K Duggal ◽  
...  
Keyword(s):  
Mouse Model ◽  
Global Economy ◽  
Adenovirus Vector ◽  
Cytokine Expression ◽  
Lung Pathology ◽  
Obese Mice ◽  
Significant Weight Loss ◽  
Diet Induced Obesity ◽  
Lean Control ◽  
Increased Risk

The COVID-19 pandemic has paralyzed the global economy and resulted in millions of deaths globally. People with co-morbidities like obesity, diabetes and hypertension are at an increased risk for severe COVID-19 illness. This is of overwhelming concern because 42% of Americans are obese, 30% are pre-diabetic and 9.4% have clinical diabetes. Here, we investigated the effect of obesity on disease severity following SARS-CoV-2 infection using a well-established mouse model of diet-induced obesity. Diet-induced obese and lean control C57BL/6N mice, transduced for ACE2 expression using replication-defective adenovirus, were infected with SARS-CoV-2, and monitored for lung pathology, viral titers, and cytokine expression. No significant differences in tissue pathology, viral replication or cytokine expression were observed between lean and obese groups. Notably, significant weight loss was observed in obese mice treated with the adenovirus vector, independent of SARS-CoV-2 infection, suggesting an obesity-dependent morbidity induced by the vector. These data indicate that the adenovirus-transduced mouse model of SARS-CoV-2 infection is inadequate for performing nutrition studies, and caution should be used when interpreting resulting data.

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