毛兰素调节Slit2/Robo1信号通路对糖尿病肾病模型大鼠肾小球内皮细胞血管生成的影响

Effect of erianin on angiogenesis of glomerular endothelial cells in diabetic nephropathy model rats by regulating Slit2/Robo1 signaling pathway

目的 探讨毛兰素对糖尿病肾病(DN)模型大鼠肾小球内皮细胞血管生成的影响及slit同源蛋白2(Slit2)/轴突导向受体蛋白1(Robo1)信号通路的作用。方法 采用高糖高脂饲料持续饲养雄性SD大鼠8周,ip给予链脲佐菌素35 mg·kg^(-1)制备DN大鼠模型。将DN模型大鼠分为模型组及模型+毛兰素10,20和40 mg·kg^(-1)组(ig给予毛兰素,持续8周),每组10只,同时设置正常对照组(ig给予0.5%羟甲基纤维素钠,持续8周)。尿蛋白定量试剂盒测定大鼠24 h尿蛋白水平,全自动生化分析仪检测血清空腹血糖(FPG)和血肌酐(Scr)水平,PAS染色观察大鼠肾组织病理变化,免疫荧光法检测肾组织血小板内皮细胞黏附分子31(CD31)和足细胞标志蛋白(PCX)表达水平,Western印迹法检测肾组织Slit2和Robo1蛋白表达。结果 与正常对照组比较,模型组大鼠FPG、Scr和24 h尿蛋白水平以及肾组织CD31、Slit2和Robo1蛋白表达显著升高(P<0.01);肾组织新增肾小球毛细血管,并出现肾小球肥大和系膜面积扩张,存在非管状CD31染色,缺少相邻PCX染色,以及部分CD31管状区域染色也缺乏相邻的PCX染色。与模型组比较,模型+毛兰素10,20和40 mg·kg^(-1)组大鼠FPG、Scr和24 h尿蛋白水平及肾组织CD31、Slit2和Robo1蛋白表达显著降低(P<0.05,P<0.01);肾组织新增肾小球毛细血管、肾小球肥大和系膜面积扩张现象减轻,CD31管状区域染色与PCX足细胞区域染色基本相邻。结论 毛兰素可能通过抑制Slit2/Robo1信号通路而抑制DN模型大鼠肾小球内皮细胞血管生成。

OBJECTIVE To investigate the effect of erianin on the angiogenesis of glomerular endothelial cells in diabetic nephropathy(DN)rats and the role of slit homolog 2 protein(Slit2)/roundabout homolog 1(Robo1)consecutive signaling pathway.METHODS Rats were fed with high sugar and high fat feed for 8 weeks,before being intraperitoneally injected with streptozotocin solution(35 mg·kg^(-1))to prepare a DN rat model.DN rats were divided into the model group and model+erianin 10,20 and 40 mg·kg^(-1) groups,with 10 rats in each,while another 10 rats served as normal control group.The urine protein quantification kit was used to measure the 24 h urine protein level of rats in each group while the automatic biochemical analyzer was used to detect the fasting plasma glucose(FPG)and serum creatinine(Scr)levels of rats in each group.PAS staining was applied to observe the pathological changes in the renal tissue of rats in each group.Immunofluorescence was used to detect the expressions of platelet endo-thelial cell adhesion molecule-31(CD31)and podocalyxin(PCX)in kidney tissue of rats in each group.Western blot was adopted to detect the expressions of Slit2 and Robo1 proteins in the renal tissues of rats in each group.RESULTS Compared with normal control group,the CD31 protein expressions,FPG,Scr,24 h urine protein levels,and renal tissue Slit2 and Robo1 protein expressions were significantly increased in the model group(P<0.05).Pathological and immunofluorescence results suggested that rats in the model group developed many neoplastic glomerular capillaries,glomerular hypertrophy,and dilated mesangial areas,with non-tubular CD31 staining lacking adjacent PCX staining,and partial staining of tubular areas of CD31 lacking adjacent PCX staining.Compared with the model group,the CD31 glomerular endothelial area,FPG,Scr,24 h urine protein levels,and protein expressions of Slit2 and Robo1 in renal tissues were significantly reduced in the model+erianin 10,20 and 40 mg·kg^(-1) groups(P<0.05).Pathological and immunofluorescence results showed new glomerular capillaries,glomerular hypertrophy and dilatation of the thylakoid area were attenuated in rats,and CD31 tubular region staining was essentially adjacent to the PCX foot cell region staining in the model+erianin 10,20 and 40 mg·kg^(-1) groups.CONCLUSION Erianin may inhibit angiogenesis in glomerular endothelial cells of DN model rats by inhibiting the Slit2/Robo1 signaling pathway.