scholarly journals Early postnatal oestradiol exposure causes insulin resistance and signs of inflammation in circulation and skeletal muscle

2009 ◽  
Vol 201 (1) ◽  
pp. 49-58 ◽  
Author(s):  
Camilla Alexanderson ◽  
Elias Eriksson ◽  
Elisabet Stener-Victorin ◽  
Malin Lönn ◽  
Agneta Holmäng
Keyword(s):  
Insulin Resistance ◽  
Skeletal Muscle ◽  
Adipose Tissue ◽  
Insulin Sensitivity ◽  
Uncoupling Protein ◽  
Female Rats ◽  
Whole Body ◽  
Low Grade ◽  
Expression Of Genes ◽  
Genes Encoding

Early postnatal events can predispose to metabolic and endocrine disease in adulthood. In this study, we evaluated the programming effects of a single early postnatal oestradiol injection on insulin sensitivity in adult female rats. We also assessed the expression of genes involved in inflammation and glucose metabolism in skeletal muscle and adipose tissue and analysed circulating inflammation markers as possible mediators of insulin resistance. Neonatal oestradiol exposure reduced insulin sensitivity and increased plasma levels of monocyte chemoattractant protein-1 (MCP-1) and soluble intercellular adhesion molecule-1. In skeletal muscle, oestradiol increased the expression of genes encoding complement component 3 (C3), Mcp-1, retinol binding protein-4 (Rbp4) and transforming growth factor β1 (Tgfβ1). C3 and MCP-1 are both related to insulin resistance, and C3, MCP-1 and TGFβ1 are also involved in inflammation. Expression of genes encoding glucose transporter-4 (Glut 4), carnitine-palmitoyl transferase 1b (Cpt1b), peroxisome proliferator-activated receptor δ (Ppard) and uncoupling protein 3 (Ucp3), which are connected to glucose uptake, lipid oxidation, and energy uncoupling, was down regulated. Expression of several inflammatory genes in skeletal muscle correlated negatively with whole-body insulin sensitivity. In s.c. inguinal adipose tissue, expression of Tgfβ1, Ppard and C3 was decreased, while expression of Rbp4 and Cpt1b was increased. Inguinal adipose tissue weight was increased but adipocyte size was unaltered, suggesting an increased number of adipocytes. We suggest that early neonatal oestrogen exposure may reduce insulin sensitivity by inducing chronic, low-grade systemic and skeletal muscle inflammation and disturbances of glucose and lipid metabolism in skeletal muscle in adulthood.

scholarly journals STAT1 dissociates adipose tissue inflammation from insulin sensitivity in obesity

2020 ◽  
Author(s):  
Ada Admin ◽  
Aaron R. Cox ◽  
Natasha Chernis ◽  
David A. Bader ◽  
Pradip K Saha ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Adipose Tissue ◽  
Insulin Sensitivity ◽  
Tca Cycle ◽  
Whole Body ◽  
Low Grade ◽  
Type I ◽  
Obese Mice ◽  
Fat Cell ◽  
Relationship Of

Obesity fosters low-grade inflammation in white adipose tissue (WAT) that may contribute to the insulin resistance that characterizes type 2 diabetes mellitus (T2DM). However, the causal relationship of these events remains unclear. The established dominance of signal transducer and activator of transcription 1 (STAT1) function in the immune response suggests an obligate link between inflammation and the co-morbidities of obesity. To this end, we sought to determine how STAT1 activity in white adipocytes affects insulin sensitivity. STAT1 expression in WAT inversely correlated with fasting plasma glucose in both obese mice and humans. Metabolomic and gene expression profiling established STAT1 deletion in adipocytes (<i>STAT1<sup>a-KO­­­</sup></i>) enhanced mitochondrial function and accelerated TCA cycle flux coupled with reduced fat cell size in subcutaneous WAT depots. <i>STAT1<sup>a-KO</sup></i> reduced WAT inflammation, but insulin resistance persisted in obese mice. Rather, elimination of type I cytokine interferon gamma (IFNg) activity enhanced insulin sensitivity in diet-induced obesity. Our findings reveal a permissive mechanism that bridges WAT inflammation to whole-body insulin sensitivity.

scholarly journals STAT1 dissociates adipose tissue inflammation from insulin sensitivity in obesity

2020 ◽  
Author(s):  
Aaron R. Cox ◽  
Natasha Chernis ◽  
David A. Bader ◽  
Pradip K Saha ◽  
Peter M. Masschelin ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Adipose Tissue ◽  
Insulin Sensitivity ◽  
Tca Cycle ◽  
Whole Body ◽  
Low Grade ◽  
Type I ◽  
Obese Mice ◽  
Diet Induced Obesity ◽  
Relationship Of

AbstractObesity fosters low-grade inflammation in white adipose tissue (WAT) that may contribute to the insulin resistance that characterizes type 2 diabetes mellitus (T2DM). However, the causal relationship of these events remains unclear. The established dominance of signal transducer and activator of transcription 1 (STAT1) function in the immune response suggests an obligate link between inflammation and the co-morbidities of obesity. To this end, we sought to determine how STAT1 activity in white adipocytes affects insulin sensitivity. STAT1 expression in WAT inversely correlated with fasting plasma glucose in both obese mice and humans. Metabolomic and gene expression profiling established STAT1 deletion in adipocytes (STAT1 fKO) enhanced mitochondrial function and accelerated TCA cycle flux coupled with subcutaneous WAT hyperplasia. STAT1 fKO reduced WAT inflammation, but insulin resistance persisted in obese mice. Rather, elimination of type I cytokine interferon gamma (IFNγ) activity enhanced insulin sensitivity in diet-induced obesity. Our findings reveal a permissive mechanism that bridges WAT inflammation to whole-body insulin sensitivity.

scholarly journals STAT1 dissociates adipose tissue inflammation from insulin sensitivity in obesity

2020 ◽  
Author(s):  
Ada Admin ◽  
Aaron R. Cox ◽  
Natasha Chernis ◽  
David A. Bader ◽  
Pradip K Saha ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Adipose Tissue ◽  
Insulin Sensitivity ◽  
Tca Cycle ◽  
Whole Body ◽  
Low Grade ◽  
Type I ◽  
Obese Mice ◽  
Fat Cell ◽  
Relationship Of

Obesity fosters low-grade inflammation in white adipose tissue (WAT) that may contribute to the insulin resistance that characterizes type 2 diabetes mellitus (T2DM). However, the causal relationship of these events remains unclear. The established dominance of signal transducer and activator of transcription 1 (STAT1) function in the immune response suggests an obligate link between inflammation and the co-morbidities of obesity. To this end, we sought to determine how STAT1 activity in white adipocytes affects insulin sensitivity. STAT1 expression in WAT inversely correlated with fasting plasma glucose in both obese mice and humans. Metabolomic and gene expression profiling established STAT1 deletion in adipocytes (<i>STAT1<sup>a-KO­­­</sup></i>) enhanced mitochondrial function and accelerated TCA cycle flux coupled with reduced fat cell size in subcutaneous WAT depots. <i>STAT1<sup>a-KO</sup></i> reduced WAT inflammation, but insulin resistance persisted in obese mice. Rather, elimination of type I cytokine interferon gamma (IFNg) activity enhanced insulin sensitivity in diet-induced obesity. Our findings reveal a permissive mechanism that bridges WAT inflammation to whole-body insulin sensitivity.

Adipose tissue and skeletal muscle expression of genes associated with thyroid hormone action in obesity and insulin resistance

Thyroid ◽  
2021 ◽  
Author(s):  
Marek Strączkowski ◽  
Agnieszka Nikołajuk ◽  
Magdalena Stefanowicz ◽  
Natalia Matulewicz ◽  
José Manuel Fernández-Real ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Skeletal Muscle ◽  
Adipose Tissue ◽  
Thyroid Hormone ◽  
Hormone Action ◽  
Thyroid Hormone Action ◽  
Expression Of Genes

scholarly journals Hepatokine ERAP1 impairs skeletal muscle insulin sensitivity via ADRB2/PKA pathway

2020 ◽  
Author(s):  
Feifan Guo ◽  
Yuguo Niu ◽  
Haizhou Jiang ◽  
Hanrui Yin ◽  
Fenfen Wang ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Skeletal Muscle ◽  
Insulin Sensitivity ◽  
Neutralizing Antibodies ◽  
Leptin Receptor ◽  
Whole Body ◽  
C2c12 Myotubes ◽  
Insulin Resistant ◽  
Skeletal Muscle Insulin Sensitivity ◽  
Pka Pathway

Abstract The current study aimed to investigate the role of endoplasmic reticulum aminopeptidase 1 (ERAP1), a novel hepatokine, in whole-body glucose metabolism. Here, we found that hepatic ERAP1 levels were increased in insulin-resistant leptin-receptor-mutated (db/db) and high-fat diet (HFD)-fed mice. Consistently, hepatic ERAP1 overexpression attenuated skeletal muscle (SM) insulin sensitivity, whereas knockdown ameliorated SM insulin resistance. Furthermore, serum and hepatic ERAP1 levels were positively correlated, and recombinant mouse ERAP1 or conditioned medium with high ERAP1 content (CM-ERAP1) attenuated insulin signaling in C2C12 myotubes, and CM-ERAP1 or HFD-induced insulin resistance was blocked by ERAP1 neutralizing antibodies. Mechanistically, ERAP1 reduced ADRB2 expression and interrupted ADRB2-dependent signaling in C2C12 myotubes. Finally, ERAP1 inhibition via global knockout or the inhibitor thimerosal improved insulin sensitivity. Together, ERAP1 is a hepatokine that impairs SM and whole-body insulin sensitivity, and its inhibition might provide a therapeutic strategy for diabetes, particularly for those with SM insulin resistance.

Dissociation of obesity and insulin resistance in transgenic mice with skeletal muscle expression of uncoupling protein 1

2008 ◽  
Vol 32 (3) ◽  
pp. 352-359 ◽  
Author(s):  
Yvonne Katterle ◽  
Susanne Keipert ◽  
Jana Hof ◽  
Susanne Klaus
Keyword(s):  
Insulin Resistance ◽  
Skeletal Muscle ◽  
Insulin Sensitivity ◽  
Uncoupling Protein ◽  
Wild Type ◽  
Uncoupling Protein 1 ◽  
Mitochondrial Uncoupling ◽  
High Fat Diets ◽  
Fat Diets ◽  
White Fat

We evaluated the effect of skeletal muscle mitochondrial uncoupling on energy and glucose metabolism under different diets. For 3 mo, transgenic HSA-mUCP1 mice with ectopic expression of uncoupling protein 1 in skeletal muscle and wild-type littermates were fed semisynthetic diets with varying macronutrient ratios (energy % carbohydrate-protein-fat): HCLF (41:42:17), HCHF (41:16:43); LCHF (11:45:44). Body composition, energy metabolism, and insulin resistance were assessed by NMR, indirect calorimetry, and insulin tolerance test, respectively. Gene expression in different organs was determined by real-time PCR. In wild type, both high-fat diets led to an increase in body weight and fat. HSA-mUCP1 mice considerably increased body fat on HCHF but stayed lean on the other diets. Irrespective of differences in body fat content, HSA-mUCP1 mice showed higher insulin sensitivity and decreased plasma insulin and liver triglycerides. Respiratory quotient and gene expression indicated overall increased carbohydrate oxidation of HSA-mUCP1 but a preferential channeling of fatty acids into muscle rather than liver with high-fat diets. Evidence for increased lipogenesis in white fat of HSA-mUCP1 mice suggests increased energy dissipating substrate cycling. Retinol binding protein 4 expression in white fat was increased in HSA-mUCP1 mice despite increased insulin sensitivity, excluding a causal role in the development of insulin resistance. We conclude that skeletal muscle mitochondrial uncoupling does not protect from the development of obesity in all circumstances. Rather it can lead to a “healthy” obese phenotype by preserving insulin sensitivity and a high metabolic flexibility, thus protecting from the development of obesity associated disturbances of glucose homeostasis.

Whole body metabolic effects of prolonged endurance training in combination with erythropoietin treatment in humans: a randomized placebo controlled trial

2013 ◽  
Vol 305 (7) ◽  
pp. E879-E889 ◽  
Author(s):  
Britt Christensen ◽  
Birgitte Nellemann ◽  
Mads S. Larsen ◽  
Line Thams ◽  
Peter Sieljacks ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Insulin Sensitivity ◽  
Endurance Training ◽  
Exercise Capacity ◽  
Uncoupling Protein ◽  
Metabolic Effects ◽  
Whole Body ◽  
Mrna Levels ◽  
Healthy Humans ◽  
Ucp2 Mrna

Erythropoietin (Epo) administration improves aerobic exercise capacity and insulin sensitivity in renal patients and also increases resting energy expenditure (REE). Similar effects are observed in response to endurance training. The aim was to compare the effects of endurance training with erythropoiesis-stimulating agent (ESA) treatment in healthy humans. Thirty-six healthy untrained men were randomized to 10 wk of either: 1) placebo ( n = 9), 2) ESA ( n = 9), 3) endurance training ( n = 10), or 4) ESA and endurance training ( n = 8). In a single-blinded design, ESA/placebo was injected one time weekly. Training consisted of biking for 1 h at 65% of wattmax three times per week. Measurements performed before and after the intervention were as follows: body composition, maximal oxygen uptake, insulin sensitivity, REE, and palmitate turnover. Uncoupling protein 2 (UCP2) mRNA levels were assessed in skeletal muscle. Fat mass decreased after training ( P = 0.003), whereas ESA induced a small but significant increase in intrahepatic fat ( P = 0.025). Serum free fatty acid (FFA) levels and palmitate turnover decreased significantly in response to training, whereas the opposite pattern was found after ESA. REE corrected for lean body mass increased in response to ESA and training, and muscle UCP2 mRNA levels increased after ESA ( P = 0.035). Insulin sensitivity increased only after training ( P = 0.011). In conclusion: 1) insulin sensitivity is not improved after ESA treatment despite improved exercise capacity, 2) the calorigenic effects of ESA may be related to increased UCP2 gene expression in skeletal muscle, and 3) training and ESA exert opposite effects on lipolysis under basal conditions, increased FFA levels and liver fat fraction was observed after ESA treatment.

scholarly journals Skeletal muscle mitochondrial and metabolic responses to a high-fat diet in female rats bred for high and low aerobic capacity

2010 ◽  
Vol 35 (2) ◽  
pp. 151-162 ◽  
Author(s):  
Scott P. Naples ◽  
Sarah J. Borengasser ◽  
R. Scott. Rector ◽  
Grace M. Uptergrove ◽  
E. Matthew Morris ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Skeletal Muscle ◽  
Insulin Sensitivity ◽  
High Fat Diet ◽  
Female Rats ◽  
Mitochondrial Morphology ◽  
Peroxisome Proliferator ◽  
High Fat ◽  
Transcriptional Responses ◽  
Peroxisome Proliferator Activated Receptor

Rats selected artificially to be low-capacity runners (LCR) possess a metabolic syndrome phenotype that is worsened by a high-fat diet (HFD), whereas rats selected to be high-capacity runners (HCR) are protected against HFD-induced obesity and insulin resistance. This study examined whether protection against, or susceptibility to, HFD-induced insulin resistance in the HCR–LCR strains is associated with contrasting metabolic adaptations in skeletal muscle. HCR and LCR rats (generation 20; n = 5–6; maximum running distance ∼1800 m vs. ∼350 m, respectively (p < 0.0001)) were divided into HFD (71.6% energy from fat) or normal chow (NC) (16.7% energy from fat) groups for 7 weeks (from 24 to 31 weeks of age). Skeletal muscle (red gastrocnemius) mitochondrial-fatty acid oxidation (FAO), mitochondrial-enzyme activity, mitochondrial-morphology, peroxisome proliferator-activated receptor γ coactivator 1α (PGC-1α), and peroxisome proliferator-activated receptor δ (PPARδ) expression and insulin sensitivity (intraperitoneal glucose tolerance tests) were measured. The HFD caused increased adiposity and reduced insulin sensitivity only in the LCR and not the HCR strain. Isolated mitochondria from the HCR skeletal muscle displayed a 2-fold-higher rate of FAO on NC, but both groups increased FAO following HFD. PGC-1α mRNA expression and superoxide dismutase activity were significantly reduced with the HFD in the LCR rats, but not in the HCR rats. PPARδ expression did not differ between strains or dietary conditions. These results do not provide a clear connection between protection of insulin sensitivity and HFD-induced adaptive changes in mitochondrial function or transcriptional responses but do not dismiss the possibility that elevated mitochondrial FAO in the HCR may play a protective role.

Whole-body skeletal muscle mass is not related to glucose tolerance or insulin sensitivity in overweight and obese men and women

2008 ◽  
Vol 33 (4) ◽  
pp. 769-774 ◽  
Author(s):  
Jennifer L. Kuk ◽  
Katherine Kilpatrick ◽  
Lance E. Davidson ◽  
Robert Hudson ◽  
Robert Ross
Keyword(s):  
Skeletal Muscle ◽  
Adipose Tissue ◽  
Insulin Sensitivity ◽  
Glucose Tolerance ◽  
Muscle Mass ◽  
Visceral Adipose Tissue ◽  
Skeletal Muscle Mass ◽  
Whole Body ◽  
Men And Women ◽  
Visceral Adipose

The relationship between skeletal muscle mass, visceral adipose tissue, insulin sensitivity, and glucose tolerance was examined in 214 overweight or obese, but otherwise healthy, men (n = 98) and women (n = 116) who participated in various exercise and (or) weight-loss intervention studies. Subjects had a 75 g oral glucose tolerance test and (or) insulin sensitivity measures by a 3 h hyperinsulinemic–euglycemic clamp technique. Whole-body skeletal muscle mass and visceral adipose tissue were measured using a multi-slice magnetic resonance imaging protocol. Total body skeletal muscle mass was not associated with any measure of glucose metabolism in men or women (p > 0.10). These observations remained independent of age and total adiposity. Conversely, visceral adipose tissue was a significant predictor of various measures of glucose metabolism in both men and women with or without control for age and (or) total body fat (p < 0.05). Although skeletal muscle is a primary site for glucose uptake and deposition, these findings suggest that unlike visceral adipose tissue, whole-body skeletal muscle mass per se is not associated with either glucose tolerance or insulin sensitivity in overweight and obese men and women.

scholarly journals Rapid development of systemic insulin resistance with overeating is not accompanied by robust changes in skeletal muscle glucose and lipid metabolism

2013 ◽  
Vol 38 (5) ◽  
pp. 512-519 ◽  
Author(s):  
Andrea S. Cornford ◽  
Alexander Hinko ◽  
Rachael K. Nelson ◽  
Ariel L. Barkan ◽  
Jeffrey F. Horowitz
Keyword(s):  
Insulin Resistance ◽  
Skeletal Muscle ◽  
Lipid Metabolism ◽  
Insulin Sensitivity ◽  
Lipid Accumulation ◽  
Rapid Development ◽  
Insulin Response ◽  
Whole Body ◽  
Muscle Lipid ◽  
Wet Weight

Prolonged overeating and the resultant weight gain are clearly linked with the development of insulin resistance and other cardiometabolic abnormalities, but adaptations that occur after relatively short periods of overeating are not completely understood. The purpose of this study was to characterize metabolic adaptations that may accompany the development of insulin resistance after 2 weeks of overeating. Healthy, nonobese subjects (n = 9) were admitted to the hospital for 2 weeks, during which time they ate ∼4000 kcals·day−1 (70 kcal·kg−1 fat free mass·day−1). Insulin sensitivity was estimated during a meal tolerance test, and a muscle biopsy was obtained to assess muscle lipid accumulation and protein markers associated with insulin resistance, inflammation, and the regulation of lipid metabolism. Whole-body insulin sensitivity declined markedly after 2 weeks of overeating (Matsuda composite index: 8.3 ± 1.3 vs. 4.6 ± 0.7, p < 0.05). However, muscle markers of insulin resistance and inflammation (i.e., phosphorylation of IRS-1-Ser312, Akt-Ser473, and c-Jun N-terminal kinase) were not altered by overeating. Intramyocellular lipids tended to increase after 2 weeks of overeating (triacylglyceride: 7.6 ± 1.6 vs. 10.0 ± 1.8 nmol·mg−1 wet weight; diacylglyceride: 104 ± 10 vs. 142 ± 23 pmol·mg−1 wet weight) but these changes did not reach statistical significance. Overeating induced a 2-fold increase in 24-h insulin response (area under the curve (AUC); p < 0.05), with a resultant ∼35% reduction in 24-h plasma fatty acid AUC (p < 0.05). This chronic reduction in circulating fatty acids may help explain the lack of a robust increase in muscle lipid accumulation. In summary, our findings suggest alterations in skeletal muscle metabolism may not contribute meaningfully to the marked whole-body insulin resistance observed after 2 weeks of overeating.

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