黄芪甲苷抑制糖尿病大鼠足细胞凋亡的作用和机制研究

Inhibitory effects of astragaloside IV on apoptosis of podocytes and its mechanism in diabetic rats

目的探讨黄芪甲苷（AS- IV）抑制糖尿病大鼠足细胞凋亡的作用及其机制，为糖尿病肾病的治疗开辟新途径。方法将体重180~220g健康雄性SD大鼠按配伍法分为正常对照组、糖尿病组和糖尿病AS- IV治疗组，每组10只，链脲霉素（STZ）腹腔注射法建立糖尿病大鼠模型，糖尿病AS- IV治疗组予AS- IV 10mg/（kg·d）治疗，共8周；糖尿病组予等量1%CMC混悬液；正常对照组不予处理。第8周末测量大鼠体重、24h尿白蛋白、血糖、糖化血红蛋白（HbA1c）、ALT、血尿素氮、肌酐水平；PAS、Masson染色，光镜观察肾脏病理变化；肾母细胞瘤基因1（WT-1）免疫组织化学染色观察肾小球足细胞密度变化，TUNEL染色观察足细胞凋亡，real- time PCR及Western blot测大鼠肾皮质凋亡相关蛋白Bcl-2、Bax及其mRNA表达的变化。结果与正常对照组相比，糖尿病组大鼠血糖、HbA1c和24h尿白蛋白增高，肾小球足细胞数量减少，系膜增生，足细胞凋亡增加，Bcl-2及其mRNA表达下调，Bax及其mRNA表达上调，差异均有统计学意义（均P＜0.05）。AS- IV可显著改善糖尿病大鼠蛋白尿，抑制肾小球足细胞数目减少、系膜区增生、足细胞凋亡，上调Bcl-2表达，抑制Bax表达。结论 AS- IV对早期糖尿病大鼠足细胞具有保护作用，可能与其调节凋亡蛋白Bcl-2和Bax，抑制足细胞凋亡相关。

Objective To investigate the effects of astragaloside IV （AS- IV） on apoptosis of podocytes and its mech-anism in diabetic rats. Methods Male SD rats were randomly divided into normal control group, diabetes group and diabetes with AS- IV treatment group with 10 in each group. Diabetes was induced by STZ intraperitoneal injection in rats. Rats in treatment group were given AS- IV 10mg/kg/d for 8 weeks. At the end of the 8th week, 24h microalbumin, body weight, blood glucose, blood glycated hemoglobin A1c, alanine aminotransferase, blood urea nitrogen and creatinine were measured;renal pathological changes were evaluated by light microscopy with PAS and Masson staining; glomerular podocyte density was examined by WT- 1 immunohistochemical staining;podocyte apoptosis was detected by TUNEL;the mRNA and protein expression of Bax and Bcl- 2, apoptosis- related proteins in rat renal cortex were determined by Western blot and real time- PCR. Results Hyper-glycemia, increased 24h microalbumin, mesangial expansion, interstitial fibrosis, podocyte loss and podocyte apoptosis, in-creased mRNA and protein expression of Bax and decreased mRNA and protein expression of Bcl- 2 were detected in diabetic rats. AS- IV treatment inhibited podocyte apoptosis, ameliorated podocyte loss and renal histopathology, decreased microalbu-min, partial y restored mRNA and protein expression of Bax and Bcl- 2. Conclusion AS- IV may inhibit podocyte apoptosis and ameliorate diabetic nephropathy by inhibiting the expression of Bax and restoring the expression of Bcl- 2 in diabetic rats.