CerS1 but Not CerS5 Gene Silencing, Improves Insulin Sensitivity and Glucose Uptake in Skeletal Muscle

Skeletal muscle is perceived as a major tissue in glucose and lipid metabolism. High fat diet (HFD) lead to the accumulation of intramuscular lipids, including: long chain acyl-CoA, diacylglycerols, and ceramides. Ceramides are considered to be one of the most important lipid groups in the generation of skeletal muscle insulin resistance. So far, it has not been clearly established whether all ceramides adversely affect the functioning of the insulin pathway, or whether there are certain ceramide species that play a pivotal role in the induction of insulin resistance. Therefore, we designed a study in which the expression of CerS1 and CerS5 genes responsible for the synthesis of C18:0-Cer and C16:0-Cer, respectively, was locally silenced in the gastrocnemius muscle of HFD-fed mice through in vivo electroporation-mediated shRNA plasmids. Our study indicates that HFD feeding induced both, the systemic and skeletal muscle insulin resistance, which was accompanied by an increase in the intramuscular lipid levels, decreased activation of the insulin pathway and, consequently, a decrease in the skeletal muscle glucose uptake. CerS1 silencing leads to a reduction in C18:0-Cer content, with a subsequent increase in the activity of the insulin pathway, and an improvement in skeletal muscle glucose uptake. Such effects were not visible in case of CerS5 silencing, which indicates that the accumulation of C18:0-Cer plays a decisive role in the induction of skeletal muscle insulin resistance.

Download Full-text

NF-κB-Inducing Kinase (NIK) Mediates Skeletal Muscle Insulin Resistance: Blockade by Adiponectin

Endocrinology ◽

10.1210/en.2011-1343 ◽

2011 ◽

Vol 152 (10) ◽

pp. 3622-3627 ◽

Cited By ~ 26

Author(s):

Sanjeev Choudhary ◽

Sandeep Sinha ◽

Yanhua Zhao ◽

Srijita Banerjee ◽

Padma Sathyanarayana ◽

...

Keyword(s):

Insulin Resistance ◽

Skeletal Muscle ◽

Glucose Uptake ◽

Kinase Activity ◽

Pi3 Kinase ◽

Dominant Negative ◽

Muscle Insulin Resistance ◽

Akt Phosphorylation ◽

Skeletal Muscle Insulin Resistance ◽

Obese Subjects

Enhanced levels of nuclear factor (NF)-κB-inducing kinase (NIK), an upstream kinase in the NF-κB pathway, have been implicated in the pathogenesis of chronic inflammation in diabetes. We investigated whether increased levels of NIK could induce skeletal muscle insulin resistance. Six obese subjects with metabolic syndrome underwent skeletal muscle biopsies before and six months after gastric bypass surgery to quantitate NIK protein levels. L6 skeletal myotubes, transfected with NIK wild-type or NIK kinase-dead dominant negative plasmids, were treated with insulin alone or with adiponectin and insulin. Effects of NIK overexpression on insulin-stimulated glucose uptake were estimated using tritiated 2-deoxyglucose uptake. NF-κB activation (EMSA), phosphatidylinositol 3 (PI3) kinase activity, and phosphorylation of inhibitor κB kinase β and serine-threonine kinase (Akt) were measured. After weight loss, skeletal muscle NIK protein was significantly reduced in association with increased plasma adiponectin and enhanced AMP kinase phosphorylation and insulin sensitivity in obese subjects. Enhanced NIK expression in cultured L6 myotubes induced a dose-dependent decrease in insulin-stimulated glucose uptake. The decrease in insulin-stimulated glucose uptake was associated with a significant decrease in PI3 kinase activity and protein kinase B/Akt phosphorylation. Overexpression of NIK kinase-dead dominant negative did not affect insulin-stimulated glucose uptake. Adiponectin treatment inhibited NIK-induced NF-κB activation and restored insulin sensitivity by restoring PI3 kinase activation and subsequent Akt phosphorylation. These results indicate that NIK induces insulin resistance and further indicate that adiponectin exerts its insulin-sensitizing effect by suppressing NIK-induced skeletal muscle inflammation. These observations suggest that NIK could be an important therapeutic target for the treatment of insulin resistance associated with inflammation in obesity and type 2 diabetes.

Download Full-text

Prevention of skeletal muscle insulin resistance by dietary cod protein in high fat-fed rats

AJP Endocrinology and Metabolism ◽

10.1152/ajpendo.2001.281.1.e62 ◽

2001 ◽

Vol 281 (1) ◽

pp. E62-E71 ◽

Cited By ~ 96

Author(s):

Charles Lavigne ◽

Frédéric Tremblay ◽

Geneviève Asselin ◽

Hélène Jacques ◽

André Marette

Keyword(s):

Insulin Resistance ◽

Skeletal Muscle ◽

Amino Acids ◽

Glucose Uptake ◽

Soy Protein ◽

Whole Body ◽

Glucose Disposal ◽

High Fat ◽

Muscle Insulin Resistance ◽

Skeletal Muscle Insulin Resistance

In the present study, we tested the hypothesis that fish protein may represent a key constituent of fish with glucoregulatory activity. Three groups of rats were fed a high-fat diet in which the protein source was casein, fish (cod) protein, or soy protein; these groups were compared with a group of chow-fed controls. High-fat feeding led to severe whole body and skeletal muscle insulin resistance in casein- or soy protein-fed rats, as assessed by the euglycemic clamp technique coupled with measurements of 2-deoxy-d-[3H]glucose uptake rates by individual tissues. However, feeding cod protein fully prevented the development of insulin resistance in high fat-fed rats. These animals exhibited higher rates of insulin-mediated muscle glucose disposal that were comparable to those of chow-fed rats. The beneficial effects of cod protein occurred without any reductions in body weight gain, adipose tissue accretion, or expression of tumor necrosis factor-α in fat and muscle. Moreover, L6 myocytes exposed to cod protein-derived amino acids showed greater rates of insulin-stimulated glucose uptake compared with cells incubated with casein- or soy protein-derived amino acids. These data demonstrate that feeding cod protein prevents obesity-induced muscle insulin resistance in high fat-fed obese rats at least in part through a direct action of amino acids on insulin-stimulated glucose uptake in skeletal muscle cells.

Download Full-text

Amelioration of High-Insulin-Induced Skeletal Muscle Cell Insulin Resistance by Resveratrol Is Linked to Activation of AMPK and Restoration of GLUT4 Translocation

Nutrients ◽

10.3390/nu12040914 ◽

2020 ◽

Vol 12 (4) ◽

pp. 914 ◽

Cited By ~ 3

Author(s):

Filip Vlavcheski ◽

Danja J. Den Hartogh ◽

Adria Giacca ◽

Evangelia Tsiani

Keyword(s):

Insulin Resistance ◽

Skeletal Muscle ◽

Glucose Transporter ◽

Muscle Cells ◽

Skeletal Muscle Cells ◽

Muscle Insulin Resistance ◽

Skeletal Muscle Insulin Resistance ◽

High Insulin

Insulin resistance, the hallmark of type 2 diabetes mellitus (T2DM), is linked to hyperinsulinemia, which develops to counterbalance initial peripheral hormone resistance. Studies indicate that chronically elevated levels of insulin lead to skeletal muscle insulin resistance by deregulating steps within the insulin signaling cascade. The polyphenol resveratrol (RSV) has been shown to have antidiabetic properties in vitro and in vivo. In the present study, we examined the effect of RSV on high insulin (HI)-induced insulin resistance in skeletal muscle cells in vitro and investigated the mechanisms involved. Parental and GLUT4myc-overexpressing L6 rat skeletal muscle cells were used. [3H]2-deoxyglucose (2DG) uptake was measured, and total and phosphorylated levels of specific proteins were examined by immunoblotting. Exposure of L6 cells to HI levels (100 nM) for 24 h decreased the acute-insulin-stimulated 2DG uptake, indicating insulin resistance. HI increased ser307 and ser636/639 phosphorylation of IRS-1 (to 184% ± 12% and 225% ± 28.9% of control, with p < 0.001 and p < 0.01, respectively) and increased the phosphorylation levels of mTOR (174% ± 6.7% of control, p < 0.01) and p70 S6K (228% ± 33.5% of control, p < 0.01). Treatment with RSV abolished these HI-induced responses. Furthermore, RSV increased the activation of AMPK and restored the insulin-mediated increase in plasma membrane GLUT4 glucose transporter levels. These data suggest that RSV has a potential to counteract the HI-induced muscle insulin resistance.

Download Full-text

Skeletal Muscle Insulin Resistance: Roles of Fatty Acid Metabolism and Exercise

Physical Therapy ◽

10.2522/ptj.20080018 ◽

2008 ◽

Vol 88 (11) ◽

pp. 1279-1296 ◽

Cited By ~ 87

Author(s):

Lorraine P Turcotte ◽

Jonathan S Fisher

Keyword(s):

Insulin Resistance ◽

Skeletal Muscle ◽

Fatty Acid ◽

Exercise Training ◽

Aerobic Exercise ◽

Glucose Uptake ◽

Muscle Cells ◽

Aerobic Exercise Training ◽

Muscle Insulin Resistance ◽

Skeletal Muscle Insulin Resistance

The purpose of this review is to provide information about the role of exercise in the prevention of skeletal muscle insulin resistance, that is, the inability of insulin to properly cause glucose uptake into skeletal muscle. Insulin resistance is associated with high levels of stored lipids in skeletal muscle cells. Aerobic exercise training decreases the amounts of these lipid products and increases the lipid oxidative capacity of muscle cells. Thus, aerobic exercise training may prevent insulin resistance by correcting a mismatch between fatty acid uptake and fatty acid oxidation in skeletal muscle. Additionally, a single session of aerobic exercise increases glucose uptake by muscle during exercise, increases the ability of insulin to promote glucose uptake, and increases glycogen accumulation after exercise, all of which are important to blood glucose control. There also is some indication that resistance exercise may be effective in preventing insulin resistance. The information provided is intended to help clinicians understand and explain the roles of exercise in reducing insulin resistance.

Download Full-text

Angiotensin II induces differential insulin action in rat skeletal muscle

Journal of Endocrinology ◽

10.1530/joe-16-0579 ◽

2017 ◽

Vol 232 (3) ◽

pp. 547-560 ◽

Cited By ~ 3

Author(s):

Juthamard Surapongchai ◽

Mujalin Prasannarong ◽

Tepmanas Bupha-Intr ◽

Vitoon Saengsirisuwan

Keyword(s):

Insulin Resistance ◽

Skeletal Muscle ◽

Angiotensin Ii ◽

Glucose Uptake ◽

Soleus Muscle ◽

Insulin Action ◽

Insulin Resistance Syndrome ◽

Rat Skeletal Muscle ◽

Muscle Insulin Resistance ◽

Skeletal Muscle Insulin Resistance

Angiotensin II (ANGII) is reportedly involved in the development of skeletal muscle insulin resistance. The present investigation evaluated the effects of two ANGII doses on the phenotypic characteristics of insulin resistance syndrome and insulin action and signaling in rat skeletal muscle. Male Sprague–Dawley rats were infused with either saline (SHAM) or ANGII at a commonly used pressor dose (100 ng/kg/min; ANGII-100) or a higher pressor dose (500 ng/kg/min; ANGII-500) via osmotic minipumps for 14 days. We demonstrated that ANGII-100-infused rats exhibited the phenotypic features of non-obese insulin resistance syndrome, including hypertension, impaired glucose tolerance and insulin resistance of glucose uptake in the soleus muscle, whereas ANGII-500-treated rats exhibited diabetes-like symptoms, such as post-prandial hyperglycemia, impaired insulin secretion and hypertriglyceridemia. At the cellular level, insulin-stimulated glucose uptake in the soleus muscle of the ANGII-100 group was 33% lower (P < 0.05) than that in the SHAM group and was associated with increased insulin-stimulated IRS-1 Ser307 and decreased Akt Ser473 and AS160 Thr642 phosphorylation and GLUT-4 expression. However, ANGII-500 infusion did not induce skeletal muscle insulin resistance or impair insulin signaling elements as initially anticipated. Moreover, we found that insulin-stimulated glucose uptake in the ANGII-500 group was accompanied by the enhanced expression of ACE2 and MasR proteins, which are the key elements in the non-classical pathway of the renin–angiotensin system. Collectively, this study demonstrates for the first time that chronic infusion with these two pressor doses of ANGII induced differential metabolic responses at both the systemic and skeletal muscle levels.

Download Full-text

Attenuation of Free Fatty Acid (FFA)-Induced Skeletal Muscle Cell Insulin Resistance by Resveratrol is Linked to Activation of AMPK and Inhibition of mTOR and p70 S6K

International Journal of Molecular Sciences ◽

10.3390/ijms21144900 ◽

2020 ◽

Vol 21 (14) ◽

pp. 4900

Author(s):

Danja J. Den Hartogh ◽

Filip Vlavcheski ◽

Adria Giacca ◽

Evangelia Tsiani

Keyword(s):

Insulin Resistance ◽

Skeletal Muscle ◽

Glucose Uptake ◽

Glucose Transporter ◽

Muscle Insulin Resistance ◽

Skeletal Muscle Insulin Resistance ◽

Specific Proteins ◽

P70 S6k

Insulin resistance, a main characteristic of type 2 diabetes mellitus (T2DM), is linked to obesity and excessive levels of plasma free fatty acids (FFA). Studies indicated that significantly elevated levels of FFAs lead to skeletal muscle insulin resistance, by dysregulating the steps in the insulin signaling cascade. The polyphenol resveratrol (RSV) was shown to have antidiabetic properties but the exact mechanism(s) involved are not clearly understood. In the present study, we examined the effect of RSV on FFA-induced insulin resistance in skeletal muscle cells in vitro and investigated the mechanisms involved. Parental and GLUT4myc-overexpressing L6 rat skeletal myotubes were used. [3H]2-deoxyglucose (2DG) uptake was measured, and total and phosphorylated levels of specific proteins were examined by immunoblotting. Exposure of L6 cells to FFA palmitate decreased the insulin-stimulated glucose uptake, indicating insulin resistance. Palmitate increased ser307 (131% ± 1.84% of control, p < 0.001) and ser636/639 (148% ± 10.1% of control, p < 0.01) phosphorylation of IRS-1, and increased the phosphorylation levels of mTOR (174% ± 15.4% of control, p < 0.01) and p70 S6K (162% ± 20.2% of control, p < 0.05). Treatment with RSV completely abolished these palmitate-induced responses. In addition, RSV increased the activation of AMPK and restored the insulin-mediated increase in (a) plasma membrane GLUT4 glucose transporter levels and (b) glucose uptake. These data suggest that RSV has the potential to counteract the FFA-induced muscle insulin resistance.

Download Full-text

Lipid-induced mTOR activation in rat skeletal muscle reversed by exercise and 5′-aminoimidazole-4-carboxamide-1-β-d-ribofuranoside

Journal of Endocrinology ◽

10.1677/joe-09-0202 ◽

2009 ◽

Vol 202 (3) ◽

pp. 441-451 ◽

Cited By ~ 41

Author(s):

Donato A Rivas ◽

Ben B Yaspelkis ◽

John A Hawley ◽

Sarah J Lessard

Keyword(s):

Insulin Resistance ◽

Skeletal Muscle ◽

Protein Kinase ◽

Exercise Training ◽

Ampk Activation ◽

Rat Skeletal Muscle ◽

Muscle Insulin Resistance ◽

Skeletal Muscle Insulin Resistance

The serine/threonine protein kinase, mammalian target of rapamycin (mTOR) is regulated by insulin and nutrient availability and has been proposed to play a central role as a nutrient sensor in skeletal muscle. mTOR associates with its binding partners, raptor and rictor, to form two structurally and functionally distinct complexes, mTOR complex 1 (mTORC1) and mTOR complex 2 (mTORC2) respectively. We have investigated the assembly of mTORC1/2 and the activation of their downstream substrates (i.e. Akt, S6K1) in response to known effectors of mTOR, excess lipid availability and AMP-activated protein kinase (AMPK) activation/exercise training in rat skeletal muscle. The in vivo formation of mTORC1 and 2 and the activation of their respective downstream substrates were increased in response to chronic (8 weeks) consumption of a high-fat diet. Diet-induced mTORC activation and skeletal muscle insulin resistance were reversed by 4 weeks of exercise training, which was associated with enhanced muscle AMPK activation. In order to determine whether AMPK activation reverses lipid-induced mTOR activation, L6 myotubes were exposed to 0.4 mM palmitate to activate mTORC1/2 in the absence or presence of 5′-aminoimidazole-4-carboxamide-1-β-d-ribofuranoside (AICAR). Palmitate exposure (4 h) increased insulin-stimulated S6K1 Thr389 phosphorylation by 60%, indicating activation of mTORC1. AMPK activation with 1 mM AICAR abolished lipid-induced mTOR activation in vitro. Our data implicates reductions in mTOR complex activation with the reversal of lipid-induced skeletal muscle insulin resistance in response to exercise training or AICAR and identifies mTOR as a potential target for the treatment of insulin resistance.

Download Full-text

Acute, local infusion of angiotensin II impairs microvascular and metabolic insulin sensitivity in skeletal muscle

Cardiovascular Research ◽

10.1093/cvr/cvy225 ◽

2018 ◽

Vol 115 (3) ◽

pp. 590-601 ◽

Cited By ~ 4

Author(s):

Dino Premilovac ◽

Emily Attrill ◽

Stephen Rattigan ◽

Stephen M Richards ◽

Jeonga Kim ◽

...

Keyword(s):

Insulin Resistance ◽

Blood Pressure ◽

Skeletal Muscle ◽

Heart Rate ◽

Blood Flow ◽

Glucose Uptake ◽

Microvascular Blood Flow ◽

Euglycaemic Clamp ◽

Hyperinsulinaemic Euglycaemic Clamp ◽

Skeletal Muscle Glucose Uptake

Abstract Aims Angiotensin II (AngII) is a potent vasoconstrictor implicated in both hypertension and insulin resistance. Insulin dilates the vasculature in skeletal muscle to increase microvascular blood flow and enhance glucose disposal. In the present study, we investigated whether acute AngII infusion interferes with insulin’s microvascular and metabolic actions in skeletal muscle. Methods and results Adult, male Sprague-Dawley rats received a systemic infusion of either saline, AngII, insulin (hyperinsulinaemic euglycaemic clamp), or insulin (hyperinsulinaemic euglycaemic clamp) plus AngII. A final, separate group of rats received an acute local infusion of AngII into a single hindleg during systemic insulin (hyperinsulinaemic euglycaemic clamp) infusion. In all animals’ systemic metabolic effects, central haemodynamics, femoral artery blood flow, microvascular blood flow, and skeletal muscle glucose uptake (isotopic glucose) were monitored. Systemic AngII infusion increased blood pressure, decreased heart rate, and markedly increased circulating glucose and insulin concentrations. Systemic infusion of AngII during hyperinsulinaemic euglycaemic clamp inhibited insulin-mediated suppression of hepatic glucose output and insulin-stimulated microvascular blood flow in skeletal muscle but did not alter insulin’s effects on the femoral artery or muscle glucose uptake. Local AngII infusion did not alter blood pressure, heart rate, or circulating glucose and insulin. However, local AngII inhibited insulin-stimulated microvascular blood flow, and this was accompanied by reduced skeletal muscle glucose uptake. Conclusions Acute infusion of AngII significantly alters basal haemodynamic and metabolic homeostasis in rats. Both local and systemic AngII infusion attenuated insulin’s microvascular actions in skeletal muscle, but only local AngII infusion led to reduced insulin-stimulated muscle glucose uptake. While increased local, tissue production of AngII may be a factor that couples microvascular insulin resistance and hypertension, additional studies are needed to determine the molecular mechanisms responsible for these vascular defects.

Download Full-text