蝉花对糖尿病大鼠肾小球沉默信息调节因子1表达的影响

目的探讨蝉花对糖尿病大鼠肾小球沉默信息调节因子1（silent information regulation 2homolog 1,SIRT1）表达的影响及其对肾脏的保护作用。方法 40只SD大鼠,随机分为对照组10只、蝉花组10只、DM模型组10只、DM＋蝉花组10只,DM模型组与DM＋蝉花组以单次腹腔注射含链脲佐菌素柠檬酸盐缓冲液60mg/kg建立糖尿病大鼠模型,对照组与蝉花组单次腹腔注射等量柠檬酸盐缓冲液。蝉花组和DM＋蝉花组给予蝉花菌丝提取液1.8g/（kg·d）灌胃治疗,对照组和DM模型组给予饮用水灌胃。治疗期间观察各组大鼠一般情况,于24周后检测各组大鼠肾功能,取肾皮质行组织病理学检查,采用RT-PCR及Western blot法检测大鼠肾小球SIRT1基因及蛋白表达情况。结果 DM模型组和DM＋蝉花组大鼠体质量、血浆胰岛素水平较对照组和蝉花组明显降低（P〈0.01）,食物摄取量、空腹血糖、糖化血红蛋白较对照组和蝉花组明显增高（P〈0.01）;DM＋蝉花组尿素氮、24h尿白蛋白、24h尿蛋白、尿白蛋白肌酐比和肾脏指数（（17.80±2.46）mmol/L、（789.00±103.20）μg/d、（18.20±3.05）mg/d、（64.50±8.34）μg/mg、8.00±1.36）较DM模型组（（22.90±3.29）mmol/L、（1 495.00±251.30）μg/d、（25.00±3.88）mg/d、（82.20±13.32）μg/mg、8.53±1.57）明显降低,大鼠肾组织系膜面积比、肾小球硬化指数及肾小球基底膜厚度（（17.80±4.87）%、56.20±17.10、（229.40±40.87）nm）较DM模型组（（26.20±6.11）%、81.00±19.48、（320.70±54.09）nm）明显减少（P〈0.05）,肾小球SIRT1mRNA和蛋白表达水平（（77.80±13.84）%、（70.60±15.17）%）较DM模型组（（36.80±12.03）%、（27.00±15.38）%）明显增高（P〈0.05）。结论蝉花可上调糖尿病大鼠肾小球SIRT1表达,可能是其延缓糖尿病肾病进展的主要机制之一。

Influence of Cordyceps Cicadae on the expression of glomerular silent information regulation 2 homolog 1in diabetic rats

Objective To explore the influence of Cordyceps Cicadae（CC）on the expression of glomerular silent information regulation 2homolog 1（SIRT1）in diabetic rats and the protective effect on kidney.Methods Forty rats were randomly divided into four groups：control group,CC group,diabetes mellitus（DM）group and DM＋CC group,with 10 rats in each group.DM group and DM＋CC group were established DM models induced by a single intraperitoneal injection of 60mg/kg streptozotocin in citrate buffer,and same volume of citrate buffer was injected intraperitoneally in control group and CC group.CC group and DM＋CC group were administrated 1.8g/（kg·d）CC extract by gavage,and control group and DM group received gavage by drinking water.All groups were observed during treatment,and renal function was detected 24 weeks later.The histopathological changes of renal cortex were studied.The expressions of SIRT1 mRNA and protein were detected by RT-PCR and Western blot methods.Results The body mass and plasma insulin levels decreased,and the food intake,fasting plasma glucose and HbA1 c increased significantly in DM and DM＋CC groups in comparison with control group and CC group（P〈0.01）.The urea nitrogen,24-hour urinary albumin,24-hour urinary protein, urinary albumin-creatinine ratio, kidney index, kidney tissue mesangial area ratio,glomerulosclerosis index and glomerular basement membrane thickness were significantly lower in DM ＋ CC group（（17.80±2.46）mmol/L,（789.00±103.20）μg/d,（18.20±3.05）mg/d,（64.50±8.34）μg/mg,8.00±1.36,（17.80±4.87）%,56.20±17.10,（229.40±40.87）nm）than those in control group（（22.90±3.29）mmol/L,（1495.00±251.30）μg/d,（25.00±3.88）mg/d,（82.20±13.32）μg/mg,8.53±1.57,（26.20±6.11）%,81.00±19.48,（320.70±54.09）nm）（P〈0.05）.The SIRT1 mRNA and protein expression levels were significantly higher in DM＋CC group（（77.80±13.84）%,（70.60±15.17）%）than those in DM group（（36.80±12.03）%,（27.00±15.38）%）（P〈