scholarly journals Hypertrophic adipocyte-derived exosomal miR-802-5p contributes to insulin resistance in cardiac myocytes through targeting HSP60

2020 ◽  
Author(s):  
Zhongyuan Wen ◽  
Junfeng Li ◽  
Yalin Fu ◽  
Yuyang Zheng ◽  
Mingke Ma ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Insulin Resistance ◽  
Insulin Sensitivity ◽  
Ventricular Myocytes ◽  
Underlying Mechanism ◽  
Neonatal Rat ◽  
Luciferase Reporter ◽  
Heat Shock Protein 60 ◽  
Akt Phosphorylation ◽  
Protein Levels

Abstract Background : Epicardial adipose tissue (EAT) is implicated in insulin resistance, which has been recognized as a strongest predictor of the development of diabetic cardiomyopathy and subsequent heart failure. However, the underlying mechanism remains incompletely understood. Herein, we investigated the effect of hypertrophic adipocytes on cardiac insulin resistance. Methods : Palmitate was used to induce hypertrophic 3T3-L1 adipocytes. Exosomes were purified from normal control or hypertrophic 3T3-L1 adipocyte-associated conditioned medium. Exosome-exposed neonatal rat ventricular myocytes (NRVMs) were treated with insulin to investigate the effects of exosomes on insulin signaling. Insulin sensitivity was evaluated by measuring insulin-stimulated Akt phosphorylation and glucose uptake. SiRNA techniques were used to downregulate protein levels and its efficiency was evaluated by western blot.Results : Hypertrophic adipocyte-derived exosomes (h-Exo) induced insulin resistance in NRVMs. Furthermore, h-Exo high-expressed miR-802-5p. Insulin sensitivity of NRVMs was impaired by miR-802-5p mimic but improved by its inhibitor. TargetScan and luciferase reporter assays revealed that heat shock protein 60 (HSP60) was a direct target of miR-802-5p. Both h-Exo and miR-802-5p mimic could downregulate HSP60 protein levels. In addition, HSP60 silencing induced insulin resistance and mitigated the insulin-sensitizing effects of adiponectin. HSP60 depletion also significantly increased the expression levels of CHOP, a marker of the unfolded protein response (UPR), and enhanced oxidative stress, accompanied by the increased phosphorylation of JNK and IRS-1 Ser307. Inhibition of both miR-802-5p and endocytosis abolished the impacts of HSP60 knockdown on the UPR and oxidative stress. Conclusion : Hypertrophic adipocyte-derived exosomal miR-802-5p caused cardiac insulin resistance in NRVMs through downregulating HSP60. These findings provide a novel mechanism by which EAT impairs cardiac function.

scholarly journals Hypertrophic adipocyte-derived exosomal miR-802-5p contributes to insulin resistance in cardiac myocytes through targeting HSP60

2020 ◽  
Author(s):  
Zhongyuan Wen ◽  
Junfeng Li ◽  
Yalin Fu ◽  
Yuyang Zheng ◽  
Mingke Ma ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Insulin Resistance ◽  
Underlying Mechanism ◽  
Luciferase Reporter ◽  
Heat Shock Protein 60 ◽  
Protein Levels ◽  
Unfolded Protein ◽  
Reporter Assays ◽  
The Unfolded Protein Response ◽  
Protein Response

Abstract Epicardial adipose tissue (EAT) is implicated in insulin resistance, which has been recognized as a strongest predictor of the development of diabetic cardiomyopathy and subsequent heart failure. However, the underlying mechanism remains incompletely understood. Herein, we investigated the effect of hypertrophic adipocytes on cardiac insulin resistance. We found that hypertrophic adipocyte-derived exosomes (h-Exo) induced insulin resistance in NRVMs. Furthermore, h-Exo high-expressed miR-802-5p. Insulin sensitivity of NRVMs was impaired by miR-802-5p mimic but improved by its inhibitor. TargetScan and luciferase reporter assays revealed that heat shock protein 60 (HSP60) was a direct target of miR-802-5p. Both h-Exo and miR-802-5p mimic could downregulate HSP60 protein levels. In addition, HSP60 silencing induced insulin resistance and mitigated the insulin-sensitizing effects of adiponectin. HSP60 depletion also significantly increased the expression levels of CHOP, a marker of the unfolded protein response (UPR), and enhanced oxidative stress, accompanied by the increased phosphorylation of JNK and IRS-1 Ser307. Inhibition of both miR-802-5p and endocytosis abolished the impacts of HSP60 knockdown on the UPR and oxidative stress. In summary, hypertrophic adipocyte-derived exosomal miR-802-5p caused cardiac insulin resistance in NRVMs through downregulating HSP60. These findings provide a novel mechanism by which EAT impairs cardiac function.

scholarly journals Increased basal level of Akt-dependent insulin signaling may be responsible for the development of insulin resistance

2009 ◽  
Vol 297 (4) ◽  
pp. E898-E906 ◽  
Author(s):  
Hui-Yu Liu ◽  
Tao Hong ◽  
Ge-Bo Wen ◽  
Jianmin Han ◽  
Degen Zuo ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Insulin Resistance ◽  
Insulin Sensitivity ◽  
Insulin Signaling ◽  
Kinase Inhibitor ◽  
Phosphatidylinositol 3 Kinase ◽  
Akt Phosphorylation ◽  
Glucose Levels ◽  
Blood Glucose Levels ◽  
Triglyceride Content

A majority of subjects with insulin resistance and hyperinsulinemia can maintain their blood glucose levels normal for the whole life presumably through protein kinase B (Akt)-dependent insulin signaling. In this study, we found that the basal Akt phosphorylation level was increased in liver and gastrocnemius of mice under the high-fat diet (HFD). Levels of mitochondrial DNA and expression of some mitochondrion-associated genes were decreased by the HFD primarily in liver. Triglyceride content was increased in both liver and gastrocnemius by the HFD. Oxidative stress was induced by the HFD in both liver and gastrocnemius. Insulin sensitivity was decreased by the HFD. All of these changes were largely or completely reversed by treatment of animals with the phosphatidylinositol 3-kinase inhibitor LY-294002 during the time when animals usually do not eat. Consequently, the overall insulin sensitivity was increased by treatment with LY-294002. Together, our results indicate that increased basal Akt-dependent insulin signaling suppresses mitochondrial production, increases ectopic fat accumulation, induces oxidative stress, and desensitizes insulin signaling in subjects with insulin resistance and hyperinsulinemia.

scholarly journals Metformin alleviates insulin resistance in obese-induced mice via remodeling gut microbiota and intestinal metabolites

2020 ◽  
Author(s):  
Ya Zhang ◽  
Yang Cheng ◽  
Jihui Zuo ◽  
Liping Yan ◽  
Qiaojuan Li ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Insulin Resistance ◽  
Insulin Sensitivity ◽  
Gut Microbiota ◽  
High Fat Diet ◽  
Underlying Mechanism ◽  
Liver Inflammation ◽  
High Fat ◽  
Intracellular Ros ◽  
And Oxidative Stress

AbstractMetformin is widely used to surmount insulin resistance (IR) and diabetes. Evidence indicates that metformin remodels gut microbiota but the underlying mechanism remain unclear. Present results showed that metformin effectively improved insulin sensitivity and alleviated liver inflammation and oxidative stress in high fat diet (HFD)-induced mice. Metabolomics analysis showed that metformin increased tauroursodeoxycholic acid (TUDCA) production by increasing the expression of bile acid synthase Cyp7a1 and Baat. In the palmitic acid (PA)-induced cell, TUDCA activated Nrf2/ARE pathway, thereby reducing intracellular ROS and improving insulin signaling. Further gut microbiota analysis showed that metformin increased the proportion of Akkermanisia muciniphlia in the HFD-fed mice, while TUDCA promoted the proliferation of A. muciniphlia but metformin did not. These findings reveal that metformin remodels the gut microbiota, reduces oxidative stress and enhances insulin sensitivity by increasing the production of TUDCA. This provides a novel mechanism by which metformin alleviates diet-induced IR and improves metabolism.

scholarly journals Insulin resistance and liver histopathology in metabolically unhealthy subjects do not correlate with the hepatic abundance of NLRP3 inflammasome nor circulating IL-1β levels

2021 ◽  
Vol 9 (1) ◽  
pp. e001975
Author(s):  
Nicolas Quezada ◽  
Ilse Valencia ◽  
Javiera Torres ◽  
Gregorio Maturana ◽  
Jaime Cerda ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Insulin Sensitivity ◽  
Liver Damage ◽  
Nlrp3 Inflammasome ◽  
Low Grade ◽  
Model Assessment ◽  
Alcoholic Fatty Liver ◽  
Protein Levels ◽  
Liver Histopathology ◽  
Inflammatory Status

IntroductionSystemic chronic low-grade inflammation has been linked to insulin resistance (IR) and non-alcoholic steatohepatitis (NASH). NOD-like receptor protein 3 (NLRP3) inflammasome and its final product, interleukin (IL)-1β, exert detrimental effects on insulin sensitivity and promote liver inflammation in murine models. Evidence linking hepatic NLRP3 inflammasome, systemic IR and NASH has been scarcely explored in humans. Herein, we correlated the hepatic abundance of NLRP3 inflammasome components and IR and NASH in humans.Research design and methodsMetabolically healthy (MH) (n=11) and metabolically unhealthy (MUH) (metabolic syndrome, n=21, and type 2 diabetes, n=14) subjects were recruited. Insulin sensitivity (homeostatic model assessment of IR (HOMA-IR) and Oral Glucose Sensitivity (OGIS120)), glycemic (glycated hemoglobin), and lipid parameters were determined by standard methods. Plasma cytokines were quantified by Magpix. Hepatic NLRP3 inflammasome components were determined at the mRNA and protein levels by reverse transcription–quantitative PCR and western blot, respectively. Liver damage was assessed by histological analysis (Non-alcoholic Fatty Liver Disease Activity Score (NAS) and Steatosis, Inflammatory Activity, and Fibrosis (SAF) scores). IR and liver histopathology were correlated with NLRP3 inflammasome components as well as with liver and plasma IL-1β levels.ResultsBody Mass Index, waist circumference, and arterial hypertension frequency were significantly higher in MUH subjects. These patients also had increased high-sensitivity C reactive protein levels compared with MH subjects. No differences in the plasma levels of IL-1β nor the hepatic content of Nlrp3, apoptosis-associated speck-like (Asc), Caspase-1, and IL-1β were detected between MUH and MH individuals. MUH subjects had significantly higher NAS and SAF scores, indicating more severe liver damage. However, histological severity did not correlate with the hepatic content of NLRP3 inflammasome components nor IL-1β levels.ConclusionOur results suggest that NLRP3 inflammasome activation is linked neither to IR nor to the inflammatory status of the liver in MUH patients.

scholarly journals Susceptibility to oxidative stress, insulin resistance, and insulin secretory response in the development of diabetes from obesity

2007 ◽  
Vol 64 (6) ◽  
pp. 391-397 ◽  
Author(s):  
Radivoj Kocic ◽  
Dusica Pavlovic ◽  
Gordana Kocic ◽  
Milica Pesic
Keyword(s):  
Oxidative Stress ◽  
Insulin Resistance ◽  
Lipid Peroxidation ◽  
Insulin Sensitivity ◽  
Healthy Subjects ◽  
Critical Role ◽  
Secretory Response ◽  
Diabetic Patients ◽  
Apparent Difference ◽  
Insulin Secretory Response

Background/Aim. Oxidative stress plays a critical role in the pathogenesis of various diseases. Recent reports indicate that obesity may induce systemic oxidative stress. The aim of the study was to potentiate oxidative stress as a factor which may aggravate peripheral insulin sensitivity and insulinsecretory response in obesity in this way to potentiate development of diabetes. The aim of the study was also to establish whether insulin-secretory response after glucagonstimulated insulin secretion is susceptible to prooxidant/ antioxidant homeostasis status, as well as to determine the extent of these changes. Methods. A mathematical model of glucose/insulin interactions and C-peptide was used to indicate the degree of insulin resistance and to assess their possible relationship with altered antioxidant/prooxidant homeostasis. The study included 24 obese healthy and 16 obese newly diagnozed non-insulin dependent diabetic patients (NIDDM) as well as 20 control healthy subjects, matched in age. Results. Total plasma antioxidative capacity, erythrocyte and plasma reduced glutathione level were significantly decreased in obese diabetic patients, but also in obese healthy subjects, compared to the values in controls. The plasma lipid peroxidation products and protein carbonyl groups were significantly higher in obese diabetics, more than in obese healthy subjects, compared to the control healthy subjects. The increase of erythrocyte lipid peroxidation at basal state was shown to be more pronounced in obese daibetics, but the apparent difference was obtained in both the obese healthy subjects and obese diabetics, compared to the control values, after exposing of erythrocytes to oxidative stress induced by H2O2. Positive correlation was found between the malondialdehyde (MDA) level and index of insulin sensitivity (FIRI). Conclusion. Increased oxidative stress together with the decreased antioxidative defence seems to contribute to decreased insulin sensitivity and impaired insulin secretory response in obese diabetics, and may be hypothesized to favour the development of diabetes during obesity.

scholarly journals Duration of rise in free fatty acids determines salicylate's effect on hepatic insulin sensitivity

2013 ◽  
Vol 217 (1) ◽  
pp. 31-43 ◽  
Author(s):  
Sandra Pereira ◽  
Wen Qin Yu ◽  
María E Frigolet ◽  
Jacqueline L Beaudry ◽  
Yaniv Shpilberg ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Insulin Sensitivity ◽  
Muscle Protein ◽  
Hepatic Insulin Resistance ◽  
Skeletal Muscle Protein ◽  
Protein Levels ◽  
Peripheral Insulin Resistance ◽  
Plasma Ffa ◽  
A Site

We have shown in rats that sodium salicylate (SS), which inhibits IkBa kinase B (IKKB), prevents hepatic and peripheral insulin resistance caused by short-term (7 h) i.v. administration of Intralipid and heparin (IH). We wished to further determine whether this beneficial effect of SS persisted after prolonged (48 h) IH infusion, which better mimics the chronic free fatty acid (FFA) elevation of obesity. Hence, we performed hyperinsulinemic euglycemic clamps with tritiated glucose methodology to determine hepatic and peripheral insulin sensitivity in rats infused with saline, IH, IH and SS, or SS alone. SS prevented peripheral insulin resistance (P<0.05) caused by prolonged plasma FFA elevation; however, it did not prevent hepatic insulin resistance. In skeletal muscle, protein levels of phospho-IkBa were augmented by prolonged IH administration and this was prevented by SS, suggesting that IH activates while SS prevents the activation of IKKB. Markers of IKKB activation, namely protein levels of phospho-IkBa and IkBa, indicated that IKKB is not activated in the liver after prolonged FFA elevation. Phosphorylation of serine 307 at insulin receptor substrate (IRS)-1, which is a marker of proximal insulin resistance, was not altered by IH administration in the liver, suggesting that this is not a site of hepatic insulin resistance in the prolonged lipid infusion model. Our results suggest that the role of IKKB in fat-induced insulin resistance is time and tissue dependent and that hepatic insulin resistance induced by prolonged lipid elevation is not due to an IRS-1 serine 307 kinase.

Abstract 13585: Up Regulation of Autophagy in Hsp60 Mutant Heart is an Adaptive Response to Increased Oxidative Stress and Causes Cardiomyopathy

Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Hirokazu Enomoto ◽  
Shinji Makino ◽  
Nishant Mittal ◽  
Akinori Kimura ◽  
Takuro Arimura ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Stress Condition ◽  
Heat Shock Protein 60 ◽  
Loss Of Function ◽  
Lower Survival Rate ◽  
Protein Levels ◽  
Fish Model ◽  
Electron Microscopy Analysis ◽  
Pericardial Edema ◽  
Microscopy Analysis

Introduction: Despite the recent advance of genetic studies, genetic causes of hereditary dilated cardiomyopathy (DCM) are still unknown in most cases. Heat shock protein 60 (Hsp60) is a well-known chaperonin, responsible for correct folding and transportation of cytoplasmic protein to mitochondria. This study is aimed to investigate whether dysfunction of Hsp60 leads to cardiomyopathy in a fish model. Methods: We previously developed a zebrafish mutant, nbl, which has a missense mutation in hsp60, leading to the loss of function. To evaluate the phenotype of cardiomyopathy in nbl, we performed RT-PCR, western blot and immunohistochemistry of the hearts. Results: Homozygous nbl embryos showed lower survival rate (65%), compared to 81% in wild-type (WT) embryos, when subjected to 33°C (stress condition). We observed pericardial edema in 92% of nbl homozygous mutants. Also, nbl homozygotes showed sudden death at around 8 months post fertilization (mpf), when grown in non-stress condition. At 8 mpf, nbl mutants showed dilated heart and high expression of reactive oxygen species (ROS). Both mRNA and protein levels of Hsp60 were similar in nbl homozygotes and WT, at 3 mpf but, much higher expression of Hsp60 in nbl homozygotes was observed at 6 mpf, beginning of death of nbl homozygous mutants. Electron microscopy analysis showed dark mitochondria, disrupted sarcomeric structure and higher number of autophagosomes in nbl homozygote hearts at 8 mpf. We, then, analyzed autophagy related genes and found that atg5, atg3 and gabarap mRNAs were increased in nbl homozygotes, suggesting the increased autophagy might underlie the pathogenesis of DCM. Furthermore, analysis of genetically unrelated patients with familial DCM, who had no mutations in the known DCM-causing genes, identified an hsp60 mutation in one DCM family in which two of four mutation prone individuals died suddenly. Over expression of nbl mutation or DCM-associated hsp60 mutation, but not normal hsp60, increased autophagosomes in Hela cells carrying GFP-LC3. Conclusions: Functional loss of Hsp60 increased oxidative stress in the heart, which leads to increased autophagy and confer the susceptibility to cardiomyopathy.

Abstract 259: KChIP2 is a Key Transcriptional Regulator of Cardiac Excitability Under Normal and Pathogenic Conditions

2016 ◽  
Vol 119 (suppl_1) ◽  
Author(s):  
Drew M Nassal ◽  
Xiaoping Wan ◽  
Haiyan Liu ◽  
Danielle Maleski ◽  
Angelina Ramirez-Navarro ◽  
...  
Keyword(s):  
Heart Disease ◽  
Ventricular Myocytes ◽  
Direct Interaction ◽  
Neonatal Rat ◽  
K Channel ◽  
Early Event ◽  
Interacting Protein ◽  
Protein Levels ◽  
Cardiac Excitability

Introduction: Arrhythmogenesis is the primary cause of death in patients with acquired heart disease, and is the consequence of profound dysregulation of both depolarizing and repolarizing currents. Reduction in expression of the auxiliary subunit K+ channel interacting protein 2 (KChIP2), which regulates the transient outward K+ current (Ito), is a common and early event in many cardiac pathologies. Notably, transcriptional changes observed in heart disease can be elicited through direct KChIP2 silencing without disease signaling, suggesting novel transcriptional capacity for KChIP2. Methods and Results: A miRNA microarray was conducted on neonatal rat ventricular myocytes (NRVM) following in vitro silencing of KChIP2, identifying the miR-34 family as a potential transcriptional target of KChIP2. qPCR confirmed reduction in miR-34b/c when over-expressing KChIP2 and increase following silencing. Luciferase assays conducted on the promoter for miR-34b/c reinforced KChIP2 repression on the promoter, while chromatin immunoprecipitation identified direct interaction of KChIP2 on the promoter. Previous studies show modified expression of KChIP2 can lead to changes in several ion channel subunits. Therefore, we investigated if this was the consequence of KChIP2 regulation via miR-34. Expression of miR-34b/c precursors reduced transcript levels of Nav1.5 and Navβ1, and reduced protein levels for Kv4.3, resulting in loss of INa and Ito. To determine the relevance in disease signaling, NRVMs were exposed to 100 μM phenylephrine for 48 hrs, significantly reducing KChIP2, Nav1.5, Navβ1, and Kv4.3, while elevating miR-34b/c. Maintaining KChIP2 expression by adenovirus or blocking miR-34 activity with antagomirs rescued the changes in channel expression. Consequently, miR-34 inhibition rescued the induction of sustained arrhythmias observed in a 2D culture of myocytes through the maintenance of cardiac excitability. Conclusion: Collectively, these observations identify dysregulation of the KChIP2/miR-34 axis as a nodal event in the development of electrical dysfunction that characterize cardiac pathologies, and further identifies miR-34 as a viable therapeutic target for managing arrhythmogenesis in patients with heart disease.

Abstract 356: KChIP2 Mediates Ion Channel Dysregulation by Novel Transcriptional Regulation of miR-34s

2014 ◽  
Vol 115 (suppl_1) ◽  
Author(s):  
Drew Nassal ◽  
Haiyan Liu ◽  
Xiaoping Wan ◽  
Angelina Ramirez-Navarro ◽  
Eckhard Ficker ◽  
...  
Keyword(s):  
Heart Failure ◽  
Ion Channel ◽  
Transcriptional Control ◽  
Ventricular Myocytes ◽  
Neonatal Rat ◽  
Physical Interaction ◽  
Protein Patterns ◽  
Protein Levels ◽  
Disease States

Introduction: Cardiac ion channel dysregulation is a hallmark of heart failure. Consistently, the disease yields dramatic decline in Ito through loss in Kv4 and its auxiliary partner KChIP2. Notably, transcriptional changes in heart failure can be elicited through KChIP2 silencing without disease signaling, suggesting potential transcriptional capacity for KChIP2. Further, disparity between resulting transcript and protein patterns suggests a mechanism compatible with modified miRNA activity. Considering other members of the KChIP family behave as transcriptional repressors, we hypothesize that KChIP2 regulates discrete miRNAs which in turn regulate cardiac excitability. Methods and Results: A miRNA microarray was conducted on neonatal rat ventricular myocytes (NRVM) following in vitro silencing of KChIP2 by siRNA, identifying the miR-34 family as potential transcriptional targets of KChIP2. Regulation, confirmed by quantitative PCR, showed reduction in miR-34a/b/c when over-expressing KChIP2 and increase following silencing. Luciferase assays were performed on the cloned promoter for miR-34b/c which reinforced direct KChIP2 repression on the miR-34b/c promoter. Furthermore, chromatin immunoprecipitation followed by PCR identified physical interaction of KChIP2 to the promoter site. Previous studies show modified expression of KChIP2 can lead to changes in several ion channel subunits. Therefore, we investigated if this was the consequence of KChIP2 regulation via miR-34. miR-34a/b/c precursors were expressed in NRVM which reduced transcript levels of Nav1.5 and Navβ1, and reduced protein levels for Kv4.3. Reflecting these changes, peak INa was reduced following miR precursor treatment. NRVMs were exposed to 100 μM phenylephrine for 48 hrs, significantly reducing KChIP2, Nav1.5, Navβ1, and Kv4.3, while elevating miR-34b/c. Returning KChIP2 expression by adenovirus normalized these changes back towards baseline, implicating the physiologic relevance of this pathway. Conclusion: These observations describe a novel mechanism where KChIP2 regulates a host of cardiac genes through transcriptional control of miRNAs, potentially explaining electrical remodeling observed in disease states where KChIP2 is reduced.

scholarly journals Selenoprotein W deficiency does not affect oxidative stress and insulin sensitivity in the skeletal muscle of high-fat diet-fed obese mice

2019 ◽  
Vol 317 (6) ◽  
pp. C1172-C1182 ◽  
Author(s):  
Min-Gyeong Shin ◽  
Hye-Na Cha ◽  
Soyoung Park ◽  
Yong-Woon Kim ◽  
Jong-Yeon Kim ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Insulin Resistance ◽  
Skeletal Muscle ◽  
Insulin Sensitivity ◽  
High Fat Diet ◽  
Control Diet ◽  
In Vivo Studies ◽  
Selenoprotein W ◽  
Obese Mice ◽  
High Fat

Selenoprotein W (SelW) is a selenium-containing protein with a redox motif found abundantly in the skeletal muscle of rodents. Previous in vitro studies suggest that SelW plays an antioxidant role; however, relatively few in vivo studies have addressed the antioxidant role of SelW. Since oxidative stress is a causative factor for the development of insulin resistance in obese subjects, we hypothesized that if SelW plays a role as an antioxidant, SelW deficiency could aggravate the oxidative stress and insulin resistance caused by a high-fat diet. SelW deficiency did not affect insulin sensitivity and H2O2 levels in the skeletal muscle of control diet-fed mice. SelW levels in the skeletal muscle were decreased by high-fat diet feeding for 12 wk. High-fat diet induced obesity and insulin resistance and increased the levels of H2O2 and oxidative stress makers, which were not affected by SelW deficiency. High-fat diet feeding increased the expression of antioxidant enzymes; however, SelW deficiency did not affect the expression levels of antioxidants. These results suggest that SelW does not play a protective role against oxidative stress and insulin resistance in the skeletal muscle of high-fat diet-fed obese mice.

Sign in / Sign up

Export Citation Format

Share Document