目的 观察双清平化方对代谢综合征大鼠Lee's指数、血糖、血脂及骨骼肌哺乳动物雷帕霉素靶蛋白(mammalian target of rapamycin,mTOR)、自噬效应蛋白1(Beclin1)、微管相关蛋白1轻链3(microtubule-associated protein1 light chain 3,LC3)蛋白表达的影响,探讨其改善糖脂代谢的作用机制。方法 大鼠给予高脂饲料加10%果糖水溶液喂养,并联合应用N-硝基-L-精氨酸甲酯(N-nitro-L-arginine methyl ester,L-NAME)及链脲佐菌素(streptozotocin,STZ)诱导代谢综合征模型。代谢综合征大鼠给予双清平化方或二甲双胍干预8周,实验前后定期测量大鼠体质量、体长、腹围、血压、糖耐量、糖化血红蛋白(glycated hemoglobin,GHb)、胰岛素(insulin,INS)、总胆固醇(total cholesterol,TC)、三酰甘油(triglyceride,TG)、低密度脂蛋白胆固醇(low-density lipoprotein cholesterol,LDL-C)、高密度脂蛋白胆固醇(high-density lipoprotein cholesterol,HDL-C),计算葡萄糖曲线下面积(OGTT-AUC)和胰岛素抵抗指数(HOMA-IR);采用苏木素-伊红(HE)染色观察骨骼肌组织病理形态学变化;采用Masson染色观察骨骼肌纤维形态变化;采用免疫组化法检测骨骼肌组织中LC3蛋白表达;采用Western blotting检测骨骼肌组织中mTOR、Beclin1和LC3蛋白表达。结果 与对照组比较,模型组大鼠空腹血糖(fasting blood glucose,FBG)、餐后2 h血糖(2 h postprandial glucose,PG2h)、OGTT-AUC、HOMA-IR、INS、GHb、TC、TG及LDL-C水平均显著升高(P<0.01),HDL-C水平显著降低(P<0.01);骨骼肌组织中mTOR蛋白表达显著上调(P<0.01),Beclin1、LC3蛋白表达显著下调(P<0.01)。与模型组比较,双清平化方组FBG、PG2h、OGTT-AUC、HOMA-IR、INS、GHb、TC、TG及LDL-C水平均显著降低(P<0.05、0.01),HDL-C水平显著升高(P<0.01);骨骼肌组织中mTOR蛋白表达水平显著上调(P<0.01),Beclin1和LC3蛋白表达显著下调(P<0.01)。结论 双清平化方可以改善代谢综合征大鼠胰岛素抵抗,改善糖脂代谢水平,抑制骨骼肌病理变化,其作用机制可能与调节骨骼肌自噬,激活骨骼肌组织自噬通路中mTOR、Beclin1、LC3蛋白表达有关。

Objective To observe the effects of Shuangqing Pinghua Recipe (双清平化方,SPR) on Lee's index,blood glucose,blood lipids and mammalian target of rapamycin (mTOR),Beclin1 and microtubule-associated protein1 light chain 3(LC3) protein expressions in skeletal muscle of rats with metabolic syndrome,and explore the mechanism of SPR on improving glucose and lipid metabolism.Methods A high-fat diet with 10% fructose water was fed and combined with the application ofN-nitro-L-arginine methyl ester (L-NAME) and streptozotocin (STZ) to induce metabolic syndrome model.Rats with metabolic syndrome were treated with SPR or metformin for 8 weeks,rats were periodically tested for body weight,body length,abdominal circumference,blood pressure and glucose tolerance,glycosylated hemoglobin (GHb),insulin (INS),total cholesterol (TC),and triglycerides (TG),low-density lipoprotein cholesterol (LDL-C),high-density lipoprotein cholesterol (HDL-C),and area under the glucose curve (OGTT-AUC) and insulin resistance index (HOMA-IR) were calculated.Hematoxylin-eosin (HE) staining was used to observe the pathological changes of skeletal muscle tissue;Masson staining was used to observe the morphological changes of skeletal muscle fibers;Immunohistochemistry was used to detect the expression of LC3 protein in skeletal muscle tissue;Western blotting was used to detect mTOR,Beclin1 and LC3 protein expressions in skeletal muscle tissue.Results Compared with control group,fasting blood glucose (FBG),2 h postprandial glucose (PG2h),OGTT-AUC,HOMA-IR,INS,GHb,TC,TG and LDL-C levels were significantly increased (P<0.01),HDL-C level was significantly decreased (P <0.01) in model group,mTOR protein expression in skeletal muscle tissues was significantly up-regulated (P<0.01),Beclin1 and LC3 protein expressions were significantly down-regulated (P<0.01).Compared with model group,FBG,PG2h,OGTT-AUC,HOMA-IR,INS,GHb,TC,TG and LDL-C levels in SPR group were significantly decreased (P<0.05,0.01),HDL-C level was significantly increased (P<0.01),mTOR protein expression in skeletal muscle was significantly up-regulated (P<0.01),Beclin1 and LC3 protein expressions were significantly down-regulated (P<0.01).Conclusion SPR can improve insulin resistance,improve glucose and lipid metabolism,and inhibit the pathological changes of skeletal muscle in rats with metabolic syndrome.Its mechanism may be related to regulating skeletal muscle autophagy and activating mTOR,Beclin1 and LC3 protein expressions.

R285.5

科技部对发展中国家常规性科技援助项目(KY201904005);唐山市糖尿病中西医结合防治团队(19130205C)