脂联素基因重组慢病毒对早期糖尿病肾病小鼠肾脏的保护作用

目的 探讨静脉注射小鼠脂联素基因重组慢病毒对糖尿病肾病(DN)模型小鼠的肾脏保护作用及其机制.方法 40只C57BL/6小鼠按数字随机法分为正常对照组(NC组)、糖尿病肾病组(DN组)、阴性对照病毒(Lenti-IRES-EGFP)治疗组(DL组)、脂联素基因重组慢病毒( Lenti-Acdc-IRES-EGFP)治疗组(DA组),每组10只.应用链脲菌素(SFZ)结合高脂饮食诱导建立DN模型.重组慢病毒注射8周后,检测各组小鼠血浆脂联素水平、肾功能、尿白蛋白排泄率、肾组织病理改变.用免疫组织化学法原位检测肾组织增殖细胞核抗原( PCNA)表达.用Western印迹检测肾组织腺苷酸活化蛋白激酶α(AMPKα)、哺乳动物雷帕霉素靶蛋白( mTOR)水平.结果 成功构建脂联素超表达DN动物模型.与NC组比较,第12周末DA组小鼠肾质量指数(肾质量/体质量,KWI)、平均肾小球体积(MGV)、系膜面积比(FMA)、24h尿蛋白(UTP)均明显升高(P＜0.05),但低于DN组、DL组(P＜0.05).DA组肾组织PCNA阳性细胞数显著低于DN组、DL组(P＜0.01).与DN组、DL组相比,DA组小鼠肾组织AMPKα磷酸化水平显著升高(P＜0.01),mTOR磷酸化水平降低(P＜0.01).结论 脂联素通过激活AMPK信号通路,抑制mTOR信号活化,进而抑制早期DN时肾组织异常增殖.

Renal protective effect of lentivirus-mediated adiponectin gene transfection on streptozocin-induced early diabetic nephropathy mice

Objective To investigate the renal protective effect of recombinant lentivirus encoding adiponectin gene on streptozocin-induced early diabetic nephropathy (DN) mice, and to explore its potential mechanism. Methods Forty C57BL/6 mice were randomly divided into normal control group (NC group, n=10), diabetic nephropathy group (DN group, n=10), Lenti-IRES-EGFP treatment group (DL group, n=10) and Lenti-Acdc-IRES-EGFP treatment group (DA group, n=10). After 8 weeks of recombinant lentivirus injection, kidney to body weight ratio (KW/BW), mean glomerular volume (MGV), fractional mesangial area (FMA), 24 h urinary protein excretion (UTP), Scr, BUN, serum albumin and adiponectin were measured. Renal pathological changes were evaluated by electron microscopy. Proliferation of glomerular and tubulointerstitial cells was assessed by immunohistochemistry using PCNA antibody. The phosphorylation of AMP-activated protein kinase (AMPK) and mammalian target of rapamycin protein (mTOR) were detected by Western blotting. Results Adiponectin was successfully over-expressed in STZ-induced DN mice after lentivirus injection. KW/BW, MGV, FMA and UTP were significantly decreased in DA group as compared to DN group and DL group (P<0.05), but were increased as compared to NC group (P<0.05). DA group animals had significantly fewer PCNA-positive cells than DN group and DL group (P<0.01). DA group mice had higher p-AMPK level and lower p-mTOR level as compared to DN group and DL group (P<0.01). Conclusion Over-expression of adiponectin has beneficial effect on early DN and attenuates aberrant proliferation of renal cells via AMPK-mTOR pathway.