黄芪甲苷IV减轻尿毒症模型大鼠肾血管内皮损伤

AstragalosideⅣreduces renal vascular endothelial injury in uremic rat model

目的探讨黄芪甲苷IV通过调控核因子E2相关因子2(Nrf2)/血红素氧合酶-1(HO-1)信号通路对尿毒症模型大鼠血管内皮的保护作用。方法将大鼠分为假手术组、模型组、黄芪甲苷低(100 mg/kg)、高(200 mg/kg)剂量组、Nrf2抑制剂组(2 mg/kg)、黄芪甲苷高剂量+Nrf2抑制剂(200 mg/kg+2 mg/kg)组,每组12只。各组腹腔注射干预给药结束后,用酶联免疫吸附法(ELISA)测血清肌酐(Scr)和血尿素氮(BUN)、血β2-微球蛋白(β2-MG)、白细胞介素-6(IL-6)和肿瘤坏死因子-α(TNF-α)含量;透射电镜观察肾组织血管结构病变;免疫荧光法检测活性氧簇(ROS);免疫荧光共定位法测血管内皮标志物CD31与Nrf2在肾组织中表达;免疫组化法检测肾组织HO-1及血管内皮损伤相关标志物-内皮型一氧化氮(eNOS)在肾组织中表达;蛋白免疫印迹法检测血管生成素样蛋白6(ANGPTL6)、单核细胞趋化蛋白-1(MCP-1)表达。结果与假手术组相比,模型组大鼠肾小管周毛细血管管腔红细胞聚集、内皮细胞肿胀及增大、管腔狭窄及受压严重;Scr、BUN、β2-MG、TNF-α及IL-6等分泌量变化明显(P<0.05);肾组织ROS、肾血管组织HO-1及eNOS阳性表达;CD31与Nrf2阳性共表达、肾组织ANGPTL6及MCP-1蛋白表达水平均升高(P<0.05)。与模型组相比,黄芪甲苷低、高剂量组大鼠肾小管周毛细血管管腔红细胞聚集、内皮细胞肿胀及增大缓解;血清毒素及炎性因子水平、肾组织ROS、肾血管内皮损伤相关蛋白ANGPTL6、MCP-1、eNOS表达降低(P<0.05);肾血管组织HO-1、CD31与Nrf2阳性共表达水平均升高(P<0.05);Nrf2抑制剂组大鼠肾小管周毛细血管管腔红细胞聚集、内皮细胞肿胀、增大进一步加重。上述指标变化趋势与黄芪甲苷Ⅳ剂量组相反(P<0.05)。结论黄芪甲苷Ⅳ可能通过促进Nrf2/HO-1通路介导的抗炎、抗氧化途径激活,减轻尿毒症大鼠肾血管内皮损伤。

Objective To investigate the protective effect of astragalosideⅣon vascular endothelium of uremic rat model by regulating nuclear factor-E2-related factor2(Nrf2)/hemeoxygenase1(HO-1)signaling pathway.MethodsSD rats were randomly divided into sham operation group,model group,low-(100 mg/kg),high-(200 mg/kg)dose astragalosideⅣgroups,Nrf2 inhibitor group(2 mg/kg)and high-dose astragalosideⅣ+Nrf2 inhibitor(200 mg/kg+2 mg/kg)group,with 12 rats in each after the performance of intraperitoneal,the renal function index like serum creatinine(Scr),urea nitrogen(BUN),β2-microglobulin(β2-MG)and interleukin-6(IL-6),tumor necrosis factor-α(TNF-α)were detected by ELISA method,the pathological changes of renal vascular structure were observed by electron microscopy;Reactive oxygen species(ROS)were detected by immuno-fluorescence technology;the expression of CD31 and Nrf2 in renal tissue was detected by immuno-fluorescence co-localization;the expression of HO-1 and endothelial nitric oxide(eNOS)in renal tissue were detected by immuno-histochemistry;the expression of angiopoietin-like protein 6(ANGPTL6)and monocyte chemoattractant protein-1(MCP-1)were detected by Western blot.Results Compared with those in the sham operation group,the erythrocyte aggregation,endothelial cell swelling and enlargement,lumen stenosis and compression in peri-tubular capillaries were serious in model group,the secretion of toxins such as Scr,BUN andβ2-MG in serum,the levels of TNF-αand IL-6,renal tissue ROS(P<0.05),positive expression of renal vascular tissue HO-1 and eNOS,the positive co-expression of CD31 and Nrf2,protein expression levels of ANGPTL6 and MCP-1 in renal tissue were increased(P<0.05).Compared with those in the model group,the erythrocyte aggregation in peri-tubular capillary lumen,the swelling and enlargement of endothelial cells were alleviated in the low-and high-dose astragalosideⅣgroups,the levels of serum toxin and inflammation,renal tissue ROS,the expression of ANGPTL6,MCP-1,and eNOS was decreased(P<0.05),and the expression of HO-1,co-expression of CD31 and Nrf2 in renal vascular tissues were increased(P<0.05);the erythrocyte aggregation in peri-tubular capillary lumen,the swelling and enlargement of endothelial cells were further aggravated in Nrf2 inhibitor group,and the change trends of the above indexes were opposite to those in the astragalosideⅣgroups(P<0.05).Conclusions AstragalosideⅣmay alleviate renal vascular endothelial injury in uremic rat model by promoting the activation of anti-inflammatory and anti-oxidant pathways mediated by the Nrf2/HO-1 pathway.