Oxidative stress-induced insulin resistance in rat skeletal muscle: role of glycogen synthase kinase-3

2008 ◽  
Vol 294 (3) ◽  
pp. E615-E621 ◽  
Author(s):  
Betsy B. Dokken ◽  
Vitoon Saengsirisuwan ◽  
John S. Kim ◽  
Mary K. Teachey ◽  
Erik J. Henriksen

Oxidative stress can contribute to the multifactorial etiology of whole body and skeletal muscle insulin resistance. No investigation has directly assessed the effect of an in vitro oxidant stress on insulin action in intact mammalian skeletal muscle. Therefore, the purpose of the present study was to characterize the molecular actions of a low-grade oxidant stress (H2O2) on insulin signaling and glucose transport in isolated skeletal muscle of lean Zucker rats. Soleus strips were incubated in 8 mM glucose for 2 h in the absence or presence of 100 mU/ml glucose oxidase, which produces H2O2 at ∼90 μM. By itself, H2O2 significantly ( P < 0.05) activated basal glucose transport activity, net glycogen synthesis, and glycogen synthase activity and increased phosphorylation of insulin receptor (Tyr), Akt (Ser473), and GSK-3β (Ser9). In contrast, this oxidant stress significantly inhibited the expected insulin-mediated enhancements in glucose transport, glycogen synthesis, and these signaling factors and allowed GSK-3β to retain a more active form. In the presence of CT-98014, a selective GSK-3 inhibitor, the ability of insulin to stimulate glucose transport and glycogen synthesis during exposure to this oxidant stress was enhanced by 20% and 39% ( P < 0.05), respectively, and insulin stimulation of the phosphorylation of insulin receptor, Akt, and GSK-3 was significantly increased by 36–58% ( P < 0.05). These results indicate that an oxidant stress can directly and rapidly induce substantial insulin resistance of skeletal muscle insulin signaling, glucose transport, and glycogen synthesis. Moreover, a small, but significant, portion of this oxidative stress-induced insulin resistance is associated with a reduced insulin-mediated suppression of the active form of GSK-3β.

2007 ◽  
Vol 293 (5) ◽  
pp. E1358-E1364 ◽  
Author(s):  
Andrew J. Hoy ◽  
Clinton R. Bruce ◽  
Anna Cederberg ◽  
Nigel Turner ◽  
David E. James ◽  
...  

Hyperglycemia is a defining feature of Type 1 and 2 diabetes. Hyperglycemia also causes insulin resistance, and our group (Kraegen EW, Saha AK, Preston E, Wilks D, Hoy AJ, Cooney GJ, Ruderman NB. Am J Physiol Endocrinol Metab Endocrinol Metab 290: E471–E479, 2006) has recently demonstrated that hyperglycemia generated by glucose infusion results in insulin resistance after 5 h but not after 3 h. The aim of this study was to investigate possible mechanism(s) by which glucose infusion causes insulin resistance in skeletal muscle and in particular to examine whether this was associated with changes in insulin signaling. Hyperglycemia (∼10 mM) was produced in cannulated male Wistar rats for up to 5 h. The glucose infusion rate required to maintain this hyperglycemia progressively lessened over 5 h (by 25%, P < 0.0001 at 5 h) without any alteration in plasma insulin levels consistent with the development of insulin resistance. Muscle glucose uptake in vivo (44%; P < 0.05) and glycogen synthesis rate (52%; P < 0.001) were reduced after 5 h compared with after 3 h of infusion. Despite these changes, there was no decrease in the phosphorylation state of multiple insulin signaling intermediates [insulin receptor, Akt, AS160 (Akt substrate of 160 kDa), glycogen synthase kinase-3β] over the same time course. In isolated soleus strips taken from control or 1- or 5-h glucose-infused animals, insulin-stimulated 2-deoxyglucose transport was similar, but glycogen synthesis was significantly reduced in the 5-h muscle sample (68% vs. 1-h sample; P < 0.001). These results suggest that the reduced muscle glucose uptake in rats after 5 h of acute hyperglycemia is due more to the metabolic effects of excess glycogen storage than to a defect in insulin signaling or glucose transport.


2002 ◽  
Vol 283 (5) ◽  
pp. E965-E970 ◽  
Author(s):  
Grith S. Olsen ◽  
Bo F. Hansen

We examined whether acute activation of 5′-AMP-activated protein kinase (AMPK) by 5′-aminoimidazole-4-carboxamide-1-β-d-ribonucleoside (AICAR) ameliorates insulin resistance in isolated rat skeletal muscle. Insulin resistance was induced in extensor digitorum longus (EDL) muscles by prolonged exposure to 1.6 mM palmitate, which inhibited insulin-stimulated glycogen synthesis to 51% of control after 5 h of incubation. Insulin-stimulated glucose transport was less affected (22% of control). The decrease in glycogen synthesis was accompanied by decreased glycogen synthase (GS) activity and increased GS phosphorylation. When including 2 mM AICAR in the last hour of the 5-h incubation with palmitate, the inhibitory effect of palmitate on insulin-stimulated glycogen synthesis and glucose transport was eliminated. This effect of AICAR was accompanied by activation of AMPK. Importantly, AMPK inhibition was able to prevent this effect. Neither treatment affected total glycogen content. However, glucose 6-phosphate was increased after inclusion of AICAR, indicating increased influx of glucose. No effect of AICAR on the inhibited insulin-stimulated GS activity or increased GS phosphorylation by palmitate could be detected. Thus the mechanism by which AMPK activation ameliorates the lipid-induced insulin resistance probably involves induction of compensatory mechanisms overriding the insulin resistance. Our results emphasize AMPK as a promising molecular target for treatment of insulin resistance.


2001 ◽  
Vol 281 (1) ◽  
pp. E8-E15 ◽  
Author(s):  
Yenshou Lin ◽  
Samar I. Itani ◽  
Theodore G. Kurowski ◽  
David J. Dean ◽  
Zhijun Luo ◽  
...  

Numerous studies have shown a correlation between changes in protein kinase C (PKC) distribution and/or activity and insulin resistance in skeletal muscle. To investigate which PKC isoforms might be involved and how they affect insulin action and signaling, studies were carried out in rat soleus muscle incubated with phorbol esters. Muscles preincubated for 1 h with 1 μM phorbol 12,13-dibutyrate (PDBu) showed an impaired ability of insulin to stimulate glucose incorporation into glycogen and a translocation of PKC-α, -βI, -θ, and -ε, and probably -βII, from the cytosol to membranes. Preincubation with 1 μM PDBu decreased activation of the insulin receptor tyrosine kinase by insulin and to an even greater extent the phosphorylation of Akt/protein kinase B and glycogen synthase kinase-3. However, it failed to diminish the activation of phosphatidylinositol 3′-kinase by insulin. Despite these changes in signaling, the stimulation by insulin of glucose transport (2-deoxyglucose uptake) and glucose incorporation into lipid and oxidation to CO2 was unaffected. The results indicate that preincubation of skeletal muscle with phorbol ester leads to a translocation of multiple conventional and novel PKC isoforms and to an impairment of several, but not all, events in the insulin-signaling cascade. They also demonstrate that these changes are associated with an inhibition of insulin-stimulated glycogen synthesis but that, at the concentration of PDBu used here, glucose transport, its incorporation into lipid, and its oxidation to CO2 are unaffected.


2020 ◽  
Vol 318 (6) ◽  
pp. C1214-C1225
Author(s):  
Amanda M. Eccardt ◽  
Ross J. Pelzel ◽  
Lyn Mattathil ◽  
Yerin A. Moon ◽  
Mark H. Mannino ◽  
...  

Reactive oxygen species such as hydrogen peroxide have been implicated in causing metabolic dysfunction such as insulin resistance. Heme groups, either by themselves or when incorporated into proteins, have been shown to scavenge peroxide and demonstrate protective effects in various cell types. Thus, we hypothesized that a metalloporphyrin similar in structure to heme, Fe(III)tetrakis(4-benzoic acid)porphyrin (FeTBAP), would be a peroxidase mimetic that could defend cells against oxidative stress. After demonstrating that FeTBAP has peroxidase activity with reduced nicotinamide adenine dinucleotide phosphate (NADPH) and NADH as reducing substrates, we determined that FeTBAP partially rescued C2C12 myotubes from peroxide-induced insulin resistance as measured by phosphorylation of AKT (S473) and insulin receptor substrate 1 (IRS-1, Y612). Furthermore, we found that FeTBAP stimulates insulin signaling in myotubes and mouse soleus skeletal muscle to about the same level as insulin for phosphorylation of AKT, IRS-1, and glycogen synthase kinase 3β (S9). We found that FeTBAP lowers intracellular peroxide levels and protects against carbonyl formation in myotubes exposed to peroxide. Additionally, we found that FeTBAP stimulates glucose transport in myotubes and skeletal muscle to about the same level as insulin. We conclude that a peroxidase mimetic can blunt peroxide-induced insulin resistance and also stimulate insulin signaling and glucose transport, suggesting a possible role of peroxidase activity in regulation of insulin signaling.


2005 ◽  
Vol 288 (6) ◽  
pp. E1074-E1081 ◽  
Author(s):  
Julie A. Sloniger ◽  
Vitoon Saengsirisuwan ◽  
Cody J. Diehl ◽  
Betsy B. Dokken ◽  
Narissara Lailerd ◽  
...  

Essential hypertension is frequently associated with insulin resistance of skeletal muscle glucose transport, with a potential role of angiotensin II in the pathogenesis of both conditions. The male heterozygous TG(mREN2)27 rat harbors the mouse transgene for renin, exhibits local elevations in angiotensin II, and is an excellent model of both hypertension and insulin resistance. The present study was designed to investigate the potential cellular mechanisms for insulin resistance in this hypertensive animal model, including an assessment of elements of the insulin-signaling pathway. Compared with nontransgenic, normotensive Sprague-Dawley control rats, male heterozygous TG(mREN2)27 rats displayed elevated ( P < 0.05) fasting plasma insulin (74%), an exaggerated insulin response (108%) during an oral glucose tolerance test, and reduced whole body insulin sensitivity. TG(mREN2)27 rats also exhibited decreased insulin-mediated glucose transport and glycogen synthase activation in both the type IIb epitrochlearis (30 and 46%) and type I soleus (22 and 64%) muscles. Importantly, there were significant reductions (∼30–50%) in insulin stimulation of tyrosine phosphorylation of the insulin receptor β-subunit and insulin receptor substrate-1 (IRS-1), IRS-1 associated with the p85 subunit of phosphatidylinositol 3-kinase, Akt Ser473 phosphorylation, and Ser9 phosphorylation of glycogen synthase kinase-3β in epitrochlearis and soleus muscles of TG(mREN2)27 rats. Soleus muscle triglyceride concentration was 25% greater in the transgenic group compared with nontransgenic animals. Collectively, these data provide the first evidence that the insulin resistance of the hypertensive male heterozygous TG(mREN2)27 rat can be attributed to specific defects in the insulin-signaling pathway in skeletal muscle.


2005 ◽  
Vol 289 (2) ◽  
pp. E241-E250 ◽  
Author(s):  
Jérôme Ruzzin ◽  
Jørgen Jensen

Glucocorticoids cause insulin resistance in skeletal muscle. The aims of the present study were to investigate the effects of contraction on glucose uptake, insulin signaling, and regulation of glycogen synthesis in skeletal muscles from rats treated with the glucocorticoid analog dexamethasone (1 mg·kg−1·day−1 ip for 12 days). Insulin resistance in dexamethasone-treated rats was confirmed by reduced insulin-stimulated glucose uptake (∼35%), glycogen synthesis (∼70%), glycogen synthase activation (∼80%), and PKB Ser473 phosphorylation (∼40%). Chronic dexamethasone treatment did not impair glucose uptake during contraction in soleus or epitrochlearis muscles. In epitrochlearis (but not in soleus), the presence of insulin during contraction enhanced glucose uptake to similar levels in control and dexamethasone-treated rats. Contraction also increased glycogen synthase fractional activity and dephosphorylated glycogen synthase at Ser645, Ser649, Ser653, and Ser657 normally in muscles from dexamethasone-treated rats. After contraction, insulin-stimulated glycogen synthesis was completely restored in epitrochlearis and improved in soleus from dexamethasone-treated rats. Contraction did not increase insulin-stimulated PKB Ser473 or glycogen synthase kinase-3 (GSK-3) phosphorylation. Instead, contraction increased GSK-3β Ser9 phosphorylation in epitrochlearis (but not in soleus) in muscles from control and dexamethasone-treated rats. In conclusion, contraction stimulates glucose uptake normally in dexamethasone-induced insulin resistant muscles. After contraction, insulin's ability to stimulate glycogen synthesis was completely restored in epitrochlearis and improved in soleus from dexamethasone-treated rats.


1989 ◽  
Vol 257 (3) ◽  
pp. E418-E425 ◽  
Author(s):  
M. O. Sowell ◽  
S. L. Dutton ◽  
M. G. Buse

Denervation (24 h) of skeletal muscle causes severe postreceptor insulin resistance of glucose transport and glycogen synthesis that is demonstrable in isolated muscles after short (30 min) preincubations. After longer preincubations (2-4 h), the insulin response of glucose transport increased to normal, whereas glycogen synthesis remained insulin resistant. Basal and insulin-stimulated amino acid transport were significantly lower in denervated muscles than in controls after short or long incubations, although the percentage stimulation of transport by insulin was not significantly different. The development of glucose transport insulin resistance after denervation was not attributable to increased sensitivity to glucocorticoids or adenosine. The selective in vitro reversal of glucose transport insulin resistance was not dependent on medium composition, did not require protein or prostaglandin synthesis, and could not be attributed to release of a positive regulator into the medium. The data suggest 1) the insulin receptor in muscle stimulates glucose transport by a signaling pathway that is not shared by other insulin-sensitive effector systems, and 2) denervation may affect insulin receptor signal transduction at more than one site.


2005 ◽  
Vol 288 (6) ◽  
pp. E1188-E1194 ◽  
Author(s):  
Betsy B. Dokken ◽  
Julie A. Sloniger ◽  
Erik J. Henriksen

Glycogen synthase kinase-3 (GSK3) has been implicated in the multifactorial etiology of skeletal muscle insulin resistance in animal models and in human type 2 diabetic subjects. However, the potential molecular mechanisms involved are not yet fully understood. Therefore, we determined if selective GSK3 inhibition in vitro leads to an improvement in insulin action on glucose transport activity in isolated skeletal muscle of insulin-resistant, prediabetic obese Zucker rats and if these effects of GSK3 inhibition are associated with enhanced insulin signaling. Type I soleus and type IIb epitrochlearis muscles from female obese Zucker rats were incubated in the absence or presence of a selective, small organic GSK3 inhibitor (1 μM CT118637, Ki < 10 nM for GSK3α and GSK3β). Maximal insulin stimulation (5 mU/ml) of glucose transport activity, glycogen synthase activity, and selected insulin-signaling factors [tyrosine phosphorylation of insulin receptor (IR) and IRS-1, IRS-1 associated with p85 subunit of phosphatidylinositol 3-kinase, and serine phosphorylation of Akt and GSK3] were assessed. GSK3 inhibition enhanced ( P <0.05) basal glycogen synthase activity and insulin-stimulated glucose transport in obese epitrochlearis (81 and 24%) and soleus (108 and 20%) muscles. GSK3 inhibition did not modify insulin-stimulated tyrosine phosphorylation of IR β-subunit in either muscle type. However, in obese soleus, GSK3 inhibition enhanced (all P < 0.05) insulin-stimulated IRS-1 tyrosine phosphorylation (45%), IRS-1-associated p85 (72%), Akt1/2 serine phosphorylation (30%), and GSK3β serine phosphorylation (39%). Substantially smaller GSK3 inhibitor-mediated enhancements of insulin action on these insulin signaling factors were observed in obese epitrochlearis. These results indicate that selective GSK3 inhibition enhances insulin action in insulin-resistant skeletal muscle of the prediabetic obese Zucker rat, at least in part by relieving the deleterious effects of GSK3 action on post-IR insulin signaling. These effects of GSK3 inhibition on insulin action are greater in type I muscle than in type IIb muscle from these insulin-resistant animals.


2000 ◽  
Vol 278 (2) ◽  
pp. E234-E243 ◽  
Author(s):  
Iñaki Azpiazu ◽  
Jill Manchester ◽  
Alexander V. Skurat ◽  
Peter J. Roach ◽  
John C. Lawrence

The effects of transgenic overexpression of glycogen synthase in different types of fast-twitch muscle fibers were investigated in individual fibers from the anterior tibialis muscle. Glycogen synthase was severalfold higher in all transgenic fibers, although the extent of overexpression was twofold greater in type IIB fibers. Effects of the transgene on increasing glycogen and phosphorylase and on decreasing UDP-glucose were also more pronounced in type IIB fibers. However, in any grouping of fibers having equivalent malate dehydrogenase activity (an index of oxidative potential), glycogen was higher in the transgenic fibers. Thus increasing synthase is sufficient to enhance glycogen accumulation in all types of fast-twitch fibers. Effects on glucose transport and glycogen synthesis were investigated in experiments in which diaphragm, extensor digitorum longus (EDL), and soleus muscles were incubated in vitro. Transport was not increased by the transgene in any of the muscles. The transgene increased basal [14C]glucose into glycogen by 2.5-fold in the EDL, which is composed primarily of IIB fibers. The transgene also enhanced insulin-stimulated glycogen synthesis in the diaphragm and soleus muscles, which are composed of oxidative fiber types. We conclude that increasing glycogen synthase activity increases the rate of glycogen synthesis in both oxidative and glycolytic fibers, implying that the control of glycogen accumulation by insulin in skeletal muscle is distributed between the glucose transport and glycogen synthase steps.


2011 ◽  
Vol 300 (5) ◽  
pp. H1637-H1644 ◽  
Author(s):  
Yukihiro Ohta ◽  
Shintaro Kinugawa ◽  
Shouji Matsushima ◽  
Taisuke Ono ◽  
Mochamad A. Sobirin ◽  
...  

Insulin resistance has been shown to occur as a consequence of heart failure. However, its exact mechanisms in this setting remain unknown. We have previously reported that oxidative stress is enhanced in the skeletal muscle from mice with heart failure after myocardial infarction (MI) ( 30 ). This study is aimed to investigate whether insulin resistance in postinfarct heart failure is due to the impairment of insulin signaling in the skeletal muscle caused by oxidative stress. Mice were divided into four groups: sham operated (sham); sham treated with apocynin, an inhibitor of NAD(P)H oxidase activation (10 mmol/l in drinking water); MI; and MI treated with apocynin. After 4 wk, intraperitoneal insulin tolerance tests were performed, and skeletal muscle samples were obtained for insulin signaling measurements. MI mice showed left ventricular dilation and dysfunction by echocardiography and increased left ventricular end-diastolic pressure and lung weight. The decrease in glucose level after insulin load significantly attenuated in MI compared with sham. Insulin-stimulated serine phosphorylation of Akt and glucose transporter-4 translocation were decreased in MI mice by 61 and 23%, respectively. Apocynin ameliorated the increase in oxidative stress and NAD(P)H oxidase activities measured by the lucigenin assay in the skeletal muscle after MI. It also improved insulin resistance and inhibited the decrease of Akt phosphorylation and glucose transporter-4 translocation. Insulin resistance was induced by the direct impairment of insulin signaling in the skeletal muscle from postinfarct heart failure, which was associated with the enhanced oxidative stress via NAD(P)H oxidase.


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