Effects Of Weight - Bearing Treadmill Exercise And MSTN Antibody On Insulin Resistance In Rats And Its Molecular Mechanism

Insulin resistance is the basis of the variety of metabolic disease, the insulin resistance is at the current level and the popular trend of younger age. The study found that dysfunction of insulin target tissues, reduce the biological activity of insulin, insulin receptor number and activity of insulin signaling changes and abnormalities can lead to insulin resistance, The IRS-1/PI3K/Akt signaling pathway is one of the important pathway of insulin signal transduction. Studies have shown that aerobic exercise can promote the increase of the insulin receptor expression and activity, promote insulin exert its biological function. Resistance exercise can strengthen the body’s insulin sensitivity of target organs, resistance exercise can strengthen the skeletal muscle growth and skeletal muscle quality, It in close correlation with MSTN expression. As a one of the resistance exercise, to explore the improvement of a footrace with heavy armor training improving insulin resistance and aerobic exercise to improve the effect and molecular mechanism of different, help develop multiple movement mode combined with intervention in the treatment of insulin resistance. In this study by analysis the load running training and joint MSTN antibody immune to improve the effect of IR. Reveal a footrace with heavy armor training to improve the molecular mechanism of IR and their relation with that of MSTN protein expression. It could help us by different ways of combining exercise form and provide theoretical basis for movement joint multiple ways to improve IR, to improve the way through the different forms of exercise and sports combined IR provide a theoretical basis.Objective:Through moderate weight treadmill training and MSTN antibody immune and two ways of joint intervention in rats with insulin resistance disease, by examining the IRS-1/PI3K/Akt and MSTN/Akt pathway of protein and gene expression analysis two ways to improve the difference of the molecular mechanism of IR.Method:Adopt healthy male pure Sprague wrote-Dawley (SD) rats50, model group fed by high fat diet eight weeks to build rat model of insulin resistance, normal control group was fed a normal diet, Through the model building of glucose tolerance and insulin sensitivity test results. Fed a normal diet was normal control group (NC group), the success of the IR model rats were randomly divided into four groups, a control group of high-fat diet (HFD group), high-fat diet+moderate intensity resistance training group (HF+MRT group), high-fat diet+MSTN antibody injection group (HF+Ab group), high-fat diet+moderate intensity resistance training group group+MSTN antibody injection group (HF+MRT+Ab group). In formal training, carries on the under part load treadmill training, daily10groups, each group to run2min,2min rest, all treadmill training grade of0°, training for8weeks, rest on Sunday.Through tested the OGTT, ITT, ISI, HOMA-IR methods such as evaluation of IR rats model to build success and after exercise and antibody immune improved glucose tolerance, insulin sensitivity degree; Using biochemical kit elisa kit to test the serum lipid and fatty cytokine levels; With HE staining technique gastrocnemius muscle cells of rat cross-sectional area for testing; Using Western blot, rt-pcr, immunohistochemical technique of rat gastrocnemius MSTN, InsR, Glut4, PI3K, and Akt,GSK3beta, mTOR and FoxO1protein and gene expression.Results:(1) After8weeks of the moderate intensity resistance training and MSTN antibody immune, each blood glucose during treadmill exercise were significantly lower than the HFD group, HFD group blood glucose at fasting,90min,120min is significantly higher than the NC group. The HF+MRT group, HF+Ab group and HF+MRT+Ab group blood glucose tolerance were improved significantly.(2) HF+MRT group and HF+MRT+Ab group fasting blood glucose (FBG) levels were significantly reduced, all the three intervention groups fasting serum insulin (FIN) was significantly lower than the HFD group. The HF+MRT group and HF+MRT+Ab group were significantly than in rats HFD group in the insulin sensitivity. The degree of insulin resistance three means of intervention group were improved significantly.(3) The weight of rats before training model group was significantly higher than NC group, after eight weeks of training, HFD body weight compared with NC group had a significant increase, HF+MRT group, HF+Ab group, HF+MRT+Ab group weight significantly lower with the HFD group. HF+MRT group, HF+MRT+FAb group than in the HFD group Lee’s index, visceral fat pad weight effect is more obvious.(4) HF+MRT group and HF+MRT+Ab serum FFA was significantly lower than NC group and HFD group, HDLC test results show that serum levels, HFD group and HF+MRT group, the total cholesterol levels were significantly higher than the control group; HF+MRT group and HF+MRT+Ab serum LDLC, HDLC levels were significantly different than the HFD group. After eight weeks weight treadmill training, HF+MRT group and HF+MRT+Ab Ins serum levels were significantly reduced.(5) HFD serum adiponectin levels were significantly increased, all three intervention groups serum adiponectin levels were improved significantly. Whether it is weight-bearing treadmill training or antibody injections were no significant effect on serum interleukin-6and leptin, but after eight weeks weight treadmill training, HF+MRT group and HF+MRT+Ab tumor necrosis factor-a levels compare with HFD was significantly reduced.(6) In this study, western blot and RT-PCR methods to detect the gastrocnemius muscle-associated protein and gene expression found that eight weeks weight treadmill training group and MSTN antibodies and the combined group of two ways gastrocnemius InsR protein expression was not significantly higher than HFD group differences, HF+MRT group InsR mRNA expression was significantly higher than HFD group, high-fat control group is always in high levels of insulin levels, also significantly reduced InsR expression in rat gastrocnemius HFD group, weight training and treadmill MSTN antibody combined effects can be significant improvement in serum insulin compensatory phenomenon.(7) HF+MRT group, HF+Ab group. HF+MRT+Ab group rats gastrocnemius muscle cell volume was significantly increased compared with HFD group, HFD group increased significantly due to the prolonged high fat diet protein expression in skeletal muscle MSTN, HF+MRT+Ab group rat gastrocnemius MSTN protein expression compared with HFD group decreased most significantly, HF+MRT group, HF+Ab group and HF+MRT+Ab group Glut4protein and mRNA expression were significantly higher than the HFD group.(8) After8weeks weight treadmill training can improve HF+MRT group, HF+Ab group protein PI3K, phosphorylation levels were also significantly higher than the HFD group, in two ways better than a single way joint intervention. HF+MRT group, HF+Ab group, HF+MRT+Ab group PI3KmRNA expression were significantly higher than the HFD group, weight-bearing treadmill training can promote increased Akt protein expression and phosphorylation levels, phosphorylation levels compare with HFD group has been significantly improved.(9) HF+MRT group and HF+MRT+Ab group GSK3β protein expression was significantly lower than HFD group, antibody injection group did not change significantly compared with HFD group, HF+MRT group and HF+MRT+Ab group GSK3β phosphorylation levels were significantly lower than HFD group, HF+Ab group HFD group compared with HFD group no significant change. Interventions are three ways to make GSK3β mRNA expression were significantly lower than HFD group, mTOR protein expression was significantly higher than HFD group, HF+MRT group, HF+Ab group, HF+MRT+Ab group FoxO1protein expression was significantly lower than HFD group, HFD group FoxO1protein significantly increased than NC group. HF+Ab group and HF+MRT+Ab group FoxO1mRNA were significantly lower than the HFD group.Conclusion:By8weeks a high-fat diet can lead to decreased glucose tolerance ability of rats. insulin tolerance ability significantly increased; Insulin resistance index increased significantly, the symptoms can be successfully constructed model of insulin resistant rats. Moderate intensity resistance training and combined to MSTN antibody immune were produce no significant effect on the expression of the gastrocnemius muscle insulin receptor, but significantly inhibited the expression of gastrocnemius MSTN, promote muscle cell proliferation and growth, can promote intracellular Glut4protein and mRNA expression, increased blood glucose transport into the cells.8weeks weight treadmill training and MSTN antibody immune is effective to enhance the ability of the body’s glucose tolerance and insulin sensitivity in rats, reducing the accumulation of body fat to achieve increased the number and size of muscle fibers, increasing the body’s glucose metabolism, regulation of blood glucose balance, two methods combined effect is more better. Two ways by promoting MSTN/Akt signal transduction pathway and activation of Akt downstream Akt/GSK3β, Akt/mTOR, Akt/FoxO1three ways to improve its main molecular mechanisms to improve insulin resistance.