| Objective:Insulin resistance which is caused by the decrease of insulin sensitivity in the target tissue is the basis of the pathogenesis of many diseases. Type ? diabetes and cardiovascular disease were triggered by insulin resistance which is a worldwide problem and has a serious impact on human activity. While adipose tissue, which as the main target organ of insulin is the largest storage organ of the body, and its endocrine function is an important factor in the regulation of energy balance, which through endocrine, autocrine, and leptin are produced by paracrine, tumor necrosis factor a, adiponectin. resistin, interleukin-6 and other cytokines and hormones to regulate blood-sugar homeostasis. Brown adipose tissue (BAT) is a highly metabolically active organ plays a major role in body energy expenditure and maintain body temperature. BAT can take up too much glucose from the bloodstream to use generate body heat. Movement is considered to be one of the effective ways to improve glycometabolism and insulin resistance, but the relationship between movement types and effects for improving insulin resistance have not been studied yet, and the molecular mechanisms of improved glycometabolism by the movement has no a detailed report. Exercise can suppress the expression of MSTN which is a negative regulator for skeletal muscle and promote skeletal muscle hypertrophy. It is not only effect muscle mass, but also regulation of BAT and lipid metabolism. Studies have shown that, BAT thermogenesis activity will decline and glucose metabolic disorders when insulin resistance occurs. Therefore, this study will be regard MSTN as an target to improve glycometabolism, through sports and MSTN antibodies interfere with insulin resistance rats induced high-fat diet, testing their physiology and biochemical indexes associated with insulin resistance and impact on downstream signaling molecules of PI3K/Akt signaling pathways, and detecting the effects on insulin signaling pathway which has always been considered closely related to improving glycometabolism. Thus the resulting contrast the molecular mechanisms differences to improve glycometabolism, ladder of strength exercise and MSTN antibodies and choose an optimum intervention factor.Methods:This study bought healthy male SD rats (Sprague-Dawley) 70 (quality qualified number:shan medical card words 08-004),2 months of age, weight 150-170 g, free drinking water, adaptability raised after a week, were randomly divided into normal group (NC.10) and a high-fat diet group (HF.60). NC groups acquired from xi'an jiaotong university medicine laboratory animal center aseptic rearing SD rats (Sprague-Dawley), normal group feeding feed purchased from xi'an jiaotong university medicine laboratory animal center, feeding by breeding rodents standard, by feeding high-fat diet group feed to buy butter, egg yolk powder, sugar, etc to the xi'an jiaotong university medicine laboratory animal center, on behalf of processing. Group raised after 3 months, by oral glucose tolerance test (OGTT) and insulin tolerance test (1ST), body weight, retroperitoneal fat, holding power, to evaluate high fat and sugar to induce insulin resistance model after the build is successful. MSTN antibodies intervention,climb the ladder of strength, MSTN and ladder of strength combined with 3 kinds of sports in gym exercise intervention of model group rats, by blood flow dynamics,kinetics of ultrasonic, holding power and other indicators, biochemical indexes such as enzyme-linked immune response; Molecular techniques for testing such as Western Blot, RT-qPCR and others. It is used of analysing that different groups within the key molecular protein gene expression of the MSTN?PI3K? Akt?mTOR? PGC-1??UCP1 and Glut4 in BAT.Results:(1) After the end of 12w high fat diet induced rat model, oral glucose tolerance test (OGTT) and insulin tolerance test (ITT). The test results show that, HF group than in NC rats in glucose and insulin there was a significant difference (P<0.05), HF group blood glucose at fasting,90 min,120 min is significantly higher than the NC group. Finally through the OGTT test, ITT tests. We determine the success of a comprehensive assessment of insulin resistance in rats model.(2) After the adoption of the intervention groups (HL group, HM group, HLM group) 8w intervention period ends, HL group and HM group than in HF rats the holding power, weight, retroperitoneal fat weight, and gastrocnemius weight have significantly improved trend, and between groups was significant difference (P<0.01), in addition, a single factor in the intervention group (HL group and HM group) than HF group rats body weight, holding power, retroperitoneal fat weight, the gastrocnemius weight, but not as good as HLM group was significantly less.(3) The test results showed that serum levels of indicators. HF serum levels of HDL-c content is less than the other groups, and there was a significant difference (P <0.05), and in serum LDL-c, CHO. the content of the FFA and CK. HF was generally higher than the other groups, which. HF group and NC group. HL group on the serum LDL-c content, showing a significant difference (P<0.05), HF group compared with HM group, HL group and HLM group serum CHO was a significant difference (P <0.05); serum FFA and CK additional content, only NC group, HLM group and HL group in serum FFA There was a significant difference (P<0.05), while the rest of the rats on serum CK content, not significant difference (P> 0.05).(4) Immunohistochemistry assay revealed MSTN expression in HM rats were significantly decreased than that in HF group rats (P<0.01), the NC group rats showed also obvious lower in expression level compared with HF group rats (P<0.05). To test the possibility that the improvement of insulin resistance by anti-MSTN polyclonal antibody is mediated by an increase in the Glut4 content in BAT, Compared with the HF group rats. Protein expressions of HM group rats significant difference (P<0.05). We also analyzed the gene expression. We found gene expression significant difference (P<0.05) compared to HF group rats.(5) To verify whether the anti-MSTN polyclonal antibody induction of thermogenesis through the PI3K-AKT-mTOR signaling pathway and its downstream targets, including PGC-la and UCP1 were examined in BAT. Protein expressions levels were significantly increases in the HM rats compared to HF rats (PI3K, P<0.01; Akt, P<0.05; Glut4, P<0.05; mTOR, P<0.05; PGC-1?, P<0.05; UCP1, P<0.05). And the mRNA expression shows the same result (PI3K,P<0.01; Akt. P<0.05; Glut4. P<0.05; mTOR, P<0.05; PGC-la, P<0.05; UCP1, P<0.05).Conclusion:By 8 weeks a high-fat diet can lead to decreased glucose tolerance ability of rats, insulin tolerance ability significantly increased; The symptoms can be successfully constructed model of insulin resistant rats. Moderate intensity resistance training and combined to MSTN antibody immune were produce significant effect on the expression of BAT MSTN. promote BAT cell proliferation and growth, can promote intracellular Glut4 protein and mRNA expression, increased blood glucose transport into the cells.8 weeks weight climb the ladder of strength 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 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 PI3K/Akt/Glut4 and PI3K/AKT/mTOR/PGC-1?/UCP1 two ways to improve its main molecular mechanisms to regulate glycometabolism. |
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