Effects Of Endurance Training On Gene Expression Of MTOR, PGC-1α And YY1 In Skeletal Muscle Of GK Rats

Under normal circumstances,energy metabolism of body is in a relatively balanced state.However,many factors can affect this balance, such as exercise, diet,genetic mutation, changes of gene expression. The abnormal energy metabolism will affect the normal life activities.Mitochondria, as the key organelle,the change of its functional status will directly affect the body's normal metabolism, lead to metabolic diseases,such as diabetes. Nowadays, diabetes mellitus, especially non-insulin-dependent diabetes,TypeⅡDiabetes,becomes a serious threat to human health. Among varieties of methods in prevention and treatment of Type II Diabetes,exercise has been widely used. Appropriate exercise can regulate the functional state of mitochondria,reduce insulin resistance and maintain the normal balance of energy metabolism. mTOR is an important regulator of energy metabolism, transcriptional complex PGC-1αis also able to control mitochondrial oxidative function to maintain energy balance,while the transcription factor YY1 is a common target protein of mTOR and PGC-1α.mTOR, through regulating PGC-1αand YY1 activities,can affect the transcriptional control of mitochondrial gene expression and oxidative function. This also provides a new direction in the treatment of metabolic diseases,as well as the exercise intervention.Objective:Investigate the effects of endurance training on blood glucose, plasma insulin levels, and the gene expression of mTOR, PGC-1α,and YY1 in GK rats.Methods:Total 12 male GK rats were randomly divided into two groups including control group (H, n=6), endurance training group (R, n=6).H group was not trained,R group was trained on the treadmill for 6 weeks,6 times a week, training method:in the first week,30min/d;in the second week,40min/d;in the third week,50min/d;and the last three weeks,60min/d, with a speed of 13m/min-16.7m/min.The rats were killed in the time during 24-48 hours after the last training. Blood glucose was measured through colorimetric method; plasma insulin concentration was measured through ELISA method.mRNA levels of mTOR, PGC-1a,and YY1 of skeletal muscle in rats were determined by using real-time PCR.Results:(1)Endurance exercise reduced the blood glucose,insulin concentration,and insulin resistance index of group R GK rats.(2)Endurance exercise significantly down-regulated PGC-1α,YY1 gene expression in skeletal muscle of group R GK rats.(3)Endurance exercise had no apparent effect on mTOR gene expression of group R GK rats.Conclusions:(1)Endurance exercise can significantly control the blood glucose,insulin concentration, and improve the insulin sensitivity in GK rats;(2)Endurance exercise significantly influences PGC-1α, YY1 gene expression, this demonstrate that PGC-1α,YY1 may be involved in the improving function of endurance exercise for TypeⅡDiabetes.