scholarly journals 1-Deoxynojirimycin Alleviates Insulin Resistance via Activation of Insulin Signaling PI3K/AKT Pathway in Skeletal Muscle of db/db Mice

Molecules ◽  
2015 ◽  
Vol 20 (12) ◽  
pp. 21700-21714 ◽  
Author(s):  
Qingpu Liu ◽  
Xuan Li ◽  
Cunyu Li ◽  
Yunfeng Zheng ◽  
Guoping Peng
Keyword(s):  
Insulin Resistance ◽  
Skeletal Muscle ◽  
Insulin Signaling ◽  
Akt Pathway

Chronic infusion of angiotensin-(1–7) improves insulin resistance and hypertension induced by a high-fructose diet in rats

2009 ◽  
Vol 296 (2) ◽  
pp. E262-E271 ◽  
Author(s):  
Jorge F. Giani ◽  
Marcos A. Mayer ◽  
Marina C. Muñoz ◽  
Ezequiel A. Silberman ◽  
Christian Höcht ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Skeletal Muscle ◽  
Metabolic Syndrome ◽  
Adipose Tissue ◽  
Insulin Signaling ◽  
Tolerance Test ◽  
Akt Pathway ◽  
Sprague Dawley ◽  
Chronic Infusion ◽  
Inhibitory Site

The current study was undertaken to determine whether Ang-(1–7) is effective in improving metabolic parameters in fructose-fed rats (FFR), a model of metabolic syndrome. Six-week-old male Sprague-Dawley rats were fed either normal rat chow (control) or the same diet plus 10% fructose in drinking water. For the last 2 wk of a 6-wk period of either diet, control and FFR were implanted with subcutaneous osmotic pumps that delivered Ang-(1–7) (100 ng·kg−1·min−1). A subgroup of each group of animals (control or FFR) underwent a sham surgery. We measured systolic blood pressure (SBP) together with plasma levels of insulin, triglycerides, and glucose. A glucose tolerance test (GTT) was performed, with plasma insulin levels determined before and 15 and 120 min after glucose administration. In addition, we evaluated insulin signaling through the IR/IRS-1/PI3K/Akt pathway as well as the phosphorylation levels of IRS-1 at inhibitory site Ser307 in skeletal muscle and adipose tissue. FFR displayed hypertriglyceridemia, hyperinsulinemia, increased SBP, and an exaggerated release of insulin during a GTT, together with decreased activation of insulin signaling through the IR/IRS-1/PI3K/Akt pathway in skeletal muscle, liver, and adipose tissue, as well as increased levels of IRS-1 phospho-Ser307 in skeletal muscle and adipose tissue, alterations that correlated with increased activation of the kinases mTOR and JNK. Chronic Ang-(1–7) treatment resulted in normalization of all alterations. These results show that Ang-(1–7) ameliorates insulin resistance in a model of metabolic syndrome via a mechanism that could involve the modulation of insulin signaling.

scholarly journals Age and tissue specific differences in the development of acute insulin resistance following injury

2009 ◽  
Vol 203 (3) ◽  
pp. 365-374 ◽  
Author(s):  
Lidong Zhai ◽  
Joseph L Messina
Keyword(s):  
Insulin Resistance ◽  
Skeletal Muscle ◽  
Insulin Signaling ◽  
Intracellular Signaling ◽  
Male Rats ◽  
Hepatic Insulin Resistance ◽  
Surgical Trauma ◽  
Induce Insulin Resistance ◽  
Old Rats ◽  
Effect Of Age

Injuries, hemorrhage, sepsis, burn, and critical illnesses all induce insulin resistance, and insulin resistance is strongly associated with advancing age. However, the effect of age on injury induced insulin resistance is not well studied. We performed surgical trauma in male rats of three different ages (3-, 6-, and 10-weeks old). Rats were either hemorrhaged to a mean arterial pressure of 35–40 mmHg and subsequently maintained at that pressure for up to 90 min, or maintained without hemorrhage as controls. Results indicate that insulin-induced intracellular signaling was diminished in liver and skeletal muscle of 6- and 10-week old rats following trauma and hemorrhage. In even younger rats, immediately post-weaning (∼3 weeks of age), insulin signaling was lost in liver, but not in skeletal muscle. Glucocorticoids can play a role in the chronic development of insulin resistance. Our results demonstrate that corticosterone levels were increased in 6- and 10-week old animals following hemorrhage, but little change was measured in 3-week old animals. Blockade of glucocorticoid synthesis prevented the development of insulin resistance in skeletal muscle, but not in liver of 6- and 10-week old rats. Moreover, skeletal muscle glucocorticoid receptor levels increased dramatically between 3 and 6 weeks of age. These results indicate that trauma and hemorrhage-induced hepatic insulin resistance occurs at all ages tested. However, there is no development of insulin resistance following trauma and hemorrhage in skeletal muscle of post-weaning rats. In skeletal muscle of 6- and 10-week old rats, inhibition of glucocorticoid levels prevents the development of insulin resistance.

Oxidative stress impairs insulin signal in skeletal muscle and causes insulin resistance in postinfarct heart failure

2011 ◽  
Vol 300 (5) ◽  
pp. H1637-H1644 ◽  
Author(s):  
Yukihiro Ohta ◽  
Shintaro Kinugawa ◽  
Shouji Matsushima ◽  
Taisuke Ono ◽  
Mochamad A. Sobirin ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Heart Failure ◽  
Insulin Resistance ◽  
Skeletal Muscle ◽  
Insulin Signaling ◽  
Glucose Transporter ◽  
Diastolic Pressure ◽  
Left Ventricular ◽  
Serine Phosphorylation ◽  
Glucose Transporter 4

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.

scholarly journals Insulin Resistance in Non-Obese Subjects Is Associated with Activation of the JNK Pathway and Impaired Insulin Signaling in Skeletal Muscle

PLoS ONE ◽  
2011 ◽  
Vol 6 (5) ◽  
pp. e19878 ◽  
Author(s):  
Umesh B. Masharani ◽  
Betty A. Maddux ◽  
Xiaojuan Li ◽  
Giorgos K. Sakkas ◽  
Kathleen Mulligan ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Skeletal Muscle ◽  
Insulin Signaling ◽  
Jnk Pathway ◽  
Impaired Insulin ◽  
Obese Subjects

Glucose infusion causes insulin resistance in skeletal muscle of rats without changes in Akt and AS160 phosphorylation

2007 ◽  
Vol 293 (5) ◽  
pp. E1358-E1364 ◽  
Author(s):  
Andrew J. Hoy ◽  
Clinton R. Bruce ◽  
Anna Cederberg ◽  
Nigel Turner ◽  
David E. James ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Skeletal Muscle ◽  
Glucose Uptake ◽  
Insulin Signaling ◽  
Glycogen Synthase ◽  
Glycogen Synthesis ◽  
Glucose Infusion ◽  
Metabolic Effects ◽  
Synthesis Rate ◽  
Muscle Sample

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.

scholarly journals Insulin signaling displayed a differential tissue-specific response to low-dose dihydrotestosterone in female mice

2018 ◽  
Vol 314 (4) ◽  
pp. E353-E365 ◽  
Author(s):  
Stanley Andrisse ◽  
Katelyn Billings ◽  
Ping Xue ◽  
Sheng Wu
Keyword(s):  
Insulin Resistance ◽  
Skeletal Muscle ◽  
Energy Storage ◽  
Protein Expression ◽  
Insulin Signaling ◽  
Low Dose ◽  
Specific Response ◽  
Pituitary Cells ◽  
Reproductive Tissues ◽  
Mrna And Protein Expression

Hyperandrogenemia and hyperinsulinemia are believed to play prominent roles in polycystic ovarian syndrome (PCOS). We explored the effects of low-dose dihydrotestosterone (DHT), a model of PCOS, on insulin signaling in metabolic and reproductive tissues in a female mouse model. Insulin resistance in the energy storage tissues is associated with type 2 diabetes. Insulin signaling in the ovaries and pituitary either directly or indirectly stimulates androgen production. Energy storage and reproductive tissues were isolated and molecular assays were performed. Livers and white adipose tissue (WAT) from DHT mice displayed lower mRNA and protein expression of insulin signaling intermediates. However, ovaries and pituitaries of DHT mice exhibited higher expression levels of insulin signaling genes/proteins. Insulin-stimulated p-AKT levels were blunted in the livers and WAT of the DHT mice but increased or remained the same in the ovaries and pituitaries compared with controls. Glucose uptake decreased in liver and WAT but was unchanged in pituitary and ovary of DHT mice. Plasma membrane GLUTs were decreased in liver and WAT but increased in ovary and pituitary of DHT mice. Skeletal muscle insulin-signaling genes were not lowered in DHT mice compared with control. DHT mice did not display skeletal muscle insulin resistance. Insulin-stimulated glucose transport increased in skeletal muscles of DHT mice compared with controls. DHT mice were hyperinsulinemic. However, the differential mRNA and protein expression pattern was independent of hyperinsulinemia in cultured hepatocytes and pituitary cells. These findings demonstrate a differential effect of DHT on the insulin-signaling pathway in energy storage vs. reproductive tissues independent of hyperinsulinemia.

(Pro)renin receptor in skeletal muscle is involved in the development of insulin resistance associated with postinfarct heart failure in mice

2014 ◽  
Vol 307 (6) ◽  
pp. E503-E514 ◽  
Author(s):  
Arata Fukushima ◽  
Shintaro Kinugawa ◽  
Shingo Takada ◽  
Shouji Matsushima ◽  
Mochamad Ali Sobirin ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Heart Failure ◽  
Insulin Resistance ◽  
Skeletal Muscle ◽  
Insulin Signaling ◽  
Glucose Transporter ◽  
Renin Angiotensin System ◽  
Left Ventricular ◽  
Serine Phosphorylation ◽  
Superoxide Production

We previously reported that insulin resistance was induced by the impairment of insulin signaling in the skeletal muscle from heart failure (HF) via NAD(P)H oxidase-dependent oxidative stress. (Pro)renin receptor [(P)RR] is involved in the activation of local renin-angiotensin system and subsequent oxidative stress. We thus examined whether (P)RR inhibitor, handle region peptide (HRP), could ameliorate insulin resistance in HF after myocardial infarction (MI) by improving oxidative stress and insulin signaling in the skeletal muscle. C57BL6J mice were divided into four groups: sham operated (Sham, n = 10), Sham treated with HRP (Sham+HRP, 0.1 mg·kg−1·day−1, n = 10), MI operated (MI, n = 10), and MI treated with HRP (MI+HRP, 0.1 mg/kg/day, n = 10). After 4 wk, MI mice showed left ventricular dysfunction, which was not affected by HRP. (P)RR was upregulated in the skeletal muscle after MI (149% of sham, P < 0.05). The decrease in plasma glucose after insulin load was smaller in MI than in Sham (21 ± 2 vs. 44 ± 3%, P < 0.05), and was greater in MI+HRP (38 ± 2%, P < 0.05) than in MI. Insulin-stimulated serine phosphorylation of Akt and glucose transporter 4 translocation were decreased in the skeletal muscle from MI by 48 and 49% of Sham, both of which were ameliorated in MI+HRP. Superoxide production and NAD(P)H oxidase activities were increased in MI, which was inhibited in MI+HRP. HRP ameliorated insulin resistance associated with HF by improving insulin signaling via the inhibition of NAD(P)H oxidase-induced superoxide production in the skeletal muscle. The (P)RR pathway is involved in the development of insulin resistance, at least in part, via the impairment of insulin signaling in the skeletal muscle from HF.

Alterations in the early steps of the insulin-signaling system in skeletal muscle of GH-transgenic mice

1999 ◽  
Vol 277 (3) ◽  
pp. E447-E454 ◽  
Author(s):  
Fernando P. Dominici ◽  
Debora Cifone ◽  
Andrzej Bartke ◽  
Daniel Turyn
Keyword(s):  
Insulin Resistance ◽  
Skeletal Muscle ◽  
Transgenic Mice ◽  
Tyrosine Phosphorylation ◽  
Insulin Signaling ◽  
Molecular Mechanisms ◽  
Kinase Activity ◽  
Signaling System ◽  
Phosphorylation State ◽  
Gh Excess

Growth hormone (GH) excess is associated with insulin resistance, but the molecular mechanisms of this association are poorly understood. In the current work, we have examined the consequences of exposure to high GH levels on the early steps of the insulin-signaling system in the muscle of bovine (b) GH-transgenic mice. The protein content and the tyrosine phosphorylation state of the insulin receptor (IR), the IR substrate-1 (IRS-1), the association between IRS-1 and the p85 subunit of phosphatidylinositol (PI) 3-kinase, and the phosphotyrosine-derived PI 3-kinase activity in this tissue were studied. We found that in skeletal muscle of bGH-transgenic mice, exposure to high circulating GH levels results in 1) reduced IR abundance, 2) reduced IR tyrosine phosphorylation, 3) reduced efficiency of IRS-1 tyrosine phosphorylation, and 4) defective activation of PI 3-kinase by insulin. These alterations may be related to the insulin resistance exhibited by these animals.

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