阿霉素诱导的局灶节段性肾小球硬化小鼠足细胞损伤的机制研究

Mechanism of podocyte injury in mice with adriamycin-induced focal segmental glomerulosclerosis

目的构建阿霉素(ADR)诱导的局灶节段性肾小球硬化(FSGS)小鼠模型,探究足细胞损伤的分子机制。方法取24只8周龄雄性BALB/c小鼠分为生理盐水组(对照组,n=6)和FSGS模型组(ADR组,n=18),分别按照10 mg/kg的剂量尾静脉注射生理盐水和ADR,采集注射ADR后的7、14、28 d小鼠以及注射生理盐水后的28 d小鼠的血液、尿液和肾组织,检测血液和尿液中血肌酐﹑尿肌酐﹑尿蛋白含量,将肾组织进行HE和MASSON染色,观察其形态变化,然后采用实时定量PCR和Western blot法检测肾皮质组织中Synaptopodin和RhoA的表达。结果与对照组比较,注射ADR 7 d后,ADR组小鼠的尿蛋白与尿肌酐比值升高,血肌酐水平升高,差异均有统计学意义(均P<0.05);注射ADR 7 d后,与对照组比较,ADR组小鼠的肾皮质组织中Synaptopodin、RhoA的mRNA和蛋白质表达量均降低,差异均有统计学意义(均P<0.05);注射ADR 28 d后,ADR组小鼠出现肾小球硬化程度恶化、肾小管损伤和间质病变纤维化,表现为严重的肾脏损伤。结论ADR可成功诱导小鼠FSGS,Synaptopodin和RhoA的表达下调可能导致足细胞损伤,进而促进小鼠形成FSGS。

Objective To establish adriamycin-induced focal segmental glomerulosclerosis(FSGS)mice model,and explore the mechanism of podocyte injury in mice with FSGS.Methods A total of 24 male BALB/c mice at 8 weeks of age were divided into normal saline(NS)group(control group,n=6)and FSGS model group(ADR group,n=18),and NS and ADR were injected by caudal vein at the dose of 10 mg/kg,respectively.Urine,blood and kidney samples were collected from the mice injected with ADR for 7,14 and 28 days and the mice injected with normal saline(NS)for 28 days,respectively.The contents of serum creatinine,urinary creatinine and urinary protein were determined,the renal histology was examined in tissue sections stained with HE and Masson,and the expression of Synaptopodin and RhoA in the renal cortical tissue were detected by the methods of real-time PCR and Western blot.Results Compared with the control group,7 days after ADR injection,the ratio of urine protein to urine creatinine and the serum creatinine level of ADR mice increased,and the difference was statistically significant(all P<0.05).After 7 days of ADR injection,the expression of Synaptopodin、RhoA mRNA and protein in renal cortex of ADR mice was significantly lower than that of control group(all P<0.05).Twenty-eight days after ADR injection,the degree of glomerulosclerosis worsened,renal tubular injury and interstitial lesion fibrosis,which showed severe kidney injury.Conclusions Adriamycin induces FSGS in mice successfully and leads to the expression downregulation of Synaptopodin and RhoA,which might promote podocyte injury in the progression of FSGS in mice.