有氧运动对胰岛素抵抗小鼠骨骼肌脂代谢相关基因表达的影响

目的:采用基因芯片技术研究6周有氧跑台运动对胰岛素抵抗(Insulin Resistance,IR)小鼠骨骼肌脂代谢相关基因表达的影响,从基因水平探究有氧运动防治IR在骨骼肌脂质代谢方面的调控机制。方法:4周龄雄性C57BL/6小鼠80只,随机分为正常饮食组(NC,n=20)和IR模型组(n=60),正常饮食组饲以基础饲料,IR组小鼠喂饲高脂饮食10周以建立IR模型。随机筛选40只成模IR小鼠再次随机分为安静对照组(HC,n=20)和运动组(HE,n=20)。对HE组小鼠施以6周、75%最大摄氧量(VO2max)强度跑台训练。实验结束后分别检测小鼠口服葡萄糖耐量(OGTT),空腹血清胰岛素(FINs)水平,血清总胆固醇(TC)、甘油三酯(TG)、高密度脂蛋白(HDL)和游离脂肪酸(FFA);并对小鼠骨骼肌组织进行基因芯片分析,对比HE与HC两组差异表达显著的基因。结果:经过6周有氧运动,HE组小鼠平均体重(BW)、FIN及血脂水平较HC组显著降低;OGTT曲线显著改善;经筛选骨骼肌基因芯片结果发现,与脂代谢相关的差异表达基因有3个,其中MAPK9和Acsl4表达显著上调,Rxr表达显著下调。结论:6周有氧运动明显改善IR小鼠脂质代谢紊乱症状。HE组小鼠骨骼肌脂代谢相关基因MAPK9、Acsl4和Rxr表达显著变化,推测这些基因可能在运动增强骨骼肌细胞脂质代谢、改善机体IR症状方面起着关键作用。

Effects of Aerobic Exercise on Relative Gene Expression of Lipid Metabolism in Skeletal Muscle of C57BL/6 Mice with Insulin Resistance

Objective To study the effects of 6-week aerobic treadmill exercise on the genes expression of lipid metabolism in the skeletal muscle of mice with insulin resistance(IR). Methods Sixty male C57BL/6 mice were randomly divided into normal control group (normal diet) and IR model group (high fat diet). After 10 weeks,IR model group were randomly divided into high fat diet control group (HC) and high fat diet plus exercise group(HE). Rats in HE group were forced to run on a treadmill for 6 weeks with the intensity of 75% VO 2 max. 24 hours after completion of 6-week exercise,oral glucose tolerance test (OGTT),fasting serum insulin level (FINs),total cholesterol (TC),triglyceride (TG),high density lipoprotein(HDL) and free fatty acids(FFA) were detected. The differentially expressed genes of skeletal muscle were analyzed and compared between the two groups. Results Comparing with group HC,body weight,fasting serum insulin level and blood-fat level decreased and glucose tolerance increased in HE group after 6-week aerobic exercise. There are 3 differentially expressed genes relevant to adipokine signaling pathway,in which MAPK9 and Acsl4 were up -regulated,and Rxr was down regulated. Conclusion 6-week aerobic exercise improved lipid metabolism in IR mice. 3 differentially expressed genes probably are involved in the adipokine signaling pathway,and related to the improved adaptation of skeletal muscle to exercise.