黄芪甲苷通过调控Sirt1/PGC-1α信号通路发挥对阿霉素肾病的保护作用

AstragalosideⅣregulates Sirt1/PGC-1αprotective effect of signal pathway on adriamycin nephropathy

目的研究黄芪甲苷通过调控沉默信息调节因子2同源蛋白1(Sirt1)/过氧化物酶体增殖物激活受体γ辅助激活因子-1α(PGC-1α)信号通路发挥对阿霉素肾病的保护作用。方法60只6周的雄性SD大鼠中取8只作正常对照组,其余大鼠尾静脉注射阿霉素建立阿霉素肾病大鼠模型,采用随机数字法将筛选出的40只模型大鼠分为模型组、西药组、黄芪甲苷低、中、高剂量组,各8只。西药组以每日0.9 mg/kg标准洛丁新混悬液灌胃,黄芪甲苷低、中、高剂量组每日分别以20、40、80 mg/kg剂量进行灌胃,每日1次,持续6周;正常组、模型组给予等容积的0.9%氯化钠溶液。干预后采用生化法检测各组24 h尿蛋白定量、血清白蛋白、丙氨酸氨基转移酶(ALT)、肌酐、尿素氮水平,酶联免疫吸附法检测肾组织白细胞介素1β(IL-1β)含量;采用苏木精-伊红染色法观察大鼠肾脏病理形态。蛋白印迹法检测肾组织中Sirt1、PGC-1α蛋白表达。结果相对于正常组,模型组24 h尿蛋白、肾组织IL-1β水平显著上升,差异均有统计意义(P<0.05);相对于模型组,西药组与黄芪甲苷高剂量组24 h尿蛋白显著下降,黄芪甲苷高剂量组IL-1β水平明显降低,差异均有统计意义(P<0.05);相对于西药组,黄芪甲苷低、中剂量组24 h尿蛋白、IL-1β上升,差异均有统计意义(P<0.05);相对于低剂量组,黄芪甲苷高剂量组24 h尿蛋白、IL-1β显著下降,差异均有统计意义(P<0.05)。相对于正常组,模型组白蛋白水平下降,ALT、肌酐、尿素氮水平上升,差异均有统计意义(P<0.05);与模型组比较,西药组与黄芪甲苷中、高剂量组白蛋白、ALT水平有所改善,且肌酐、尿素氮水平下降,差异均有统计意义(P<0.05)。西药组与黄芪甲苷高剂量组的各指标相当,优于黄芪甲苷低、中剂量组,差异均有统计意义(P<0.05)。正常组肾小球结构正常,无病理变化;模型组肾脏系膜有增生,系膜基质增多,肾小管上皮有肿胀,可见大量炎症细胞浸润;西药组与黄芪甲苷中、高剂量组肾小球系膜细胞增生有不同程度减轻,肾小管上皮细胞水肿得到改善,炎症细胞浸润缓解,效果优于黄芪甲苷低剂量组。与正常组比较,模型组Sirt1、PGC-1α蛋白表达升高,差异均有统计意义(P<0.05);与模型组比较,西药组Sirt1、PGC-1α蛋白抑制表达,差异均有统计意义(P<0.05);黄芪甲苷高剂量组Sirt1、PGC-1α蛋白表达高于低、中剂量组,差异均有统计意义(P<0.05)。结论黄芪甲苷能改善阿霉素诱导的大鼠肾损伤,通过上调肾组织Sirt1、PGC-1α蛋白表达以抑制炎症反应,改善肾功能而延缓病情发展,其中80 mg/kg剂量的效果更佳。

Objective To study the protective effect of astragalosideⅣin adriamycin nephropathy via regulating silent mating type information regulation 2 homolog 1(Sirt1)/peroxisome proliferator-activated receptorγcoactivator-1α(PGC-1α)signaling pathway.Methods Eight of 606-week-old male SD rats were selected as control group,and the rest of rats were made into adriamycin nephropathy models by a single intravenous injection through the tail vein.Forty model rats were selected by random number method and divided into model group,western medicine group,astragalosideⅣlow-dose,medium-dose and high-dose groups,each with 8 rats.The western medicine group was administered with 0.9 mg/kg standard lotensin suspension by gavage daily,and astragalosideⅣlow-dose,middle dose and high-dose groups were given 20,40 and 80 mg/kg astragalosideⅣby gavage daily for 6 weeks.Meantime,the control group and model group were given equal volume of normal saline.After intervention,24 h urinary protein,serum albumin,alanine aminotransferase,serum creatinine and blood urea nitrogen content were measured by biochemical method,and interleukin-1β(IL-1β)in renal tissue was detected by enzyme-linked immunosorbent assay.The pathological morphology of rat kidney was observed by hematoxylin eosin staining,and the protein expression levels of Sirt1 and PGC-1αin renal tissue were detected by Western blotting.Results The 24 h urinary protein and renal tissue IL-1βlevels were significantly increased in model group compared with control group,the differences were statistically significant(P<0.05).Compared with model group,24 h urinary protein in western medicine group and astragalosideⅣhigh-dose group was significantly decreased,while IL-1βlevel in astragalosideⅣhigh-dose group was significantly decreased,the differences were statistically significant(P<0.05).Compared with western medicine group,the 24 h urinary protein and IL-1βwere increased in astragalosideⅣlow dose and medium dose groups,while the 24 h urinary protein and IL-1βwere significantly decreased in astragalosideⅣhigh dose group compared with astragalosideⅣlow dose group,the differences were statistically significant(P<0.05).Compared with control group,serum albumin level was decreased,while alanine aminotransferase,serum creatinine and blood urea nitrogen contents were increased in model group,the differences were statistically significant(P<0.05).The levels of serum albumin and alanine aminotransferase were improved,and the levels of serum creatinine and blood urea nitrogen were decreased in western medicine group and astragalosideⅣmedium and high dose groups,the differences were statistically significant(P<0.05).The western medicine group was comparable to the astragalosideⅣhigh dose group in all indices,and better than those of astragalosideⅣlow and medium dose groups,the differences were statistically significant(P<0.05).In control group,the glomerular structure was normal without pathological changes.In model group,mesangial cell hyperplasia,glomerular mesangial matrix expansion,cloudy swelling of renal tubular epithelium and infiltration of a large number of inflammatory cells were observed.The mesangial cell hyperplasia,swelling of renal tubular epithelium and inflammatory cell infiltration were improved in western medicine group and astragalosideⅣmedium and high dose groups,and the improvement was better than that of astragalosideⅣlow dose group.Compared with control group,the protein expressions of Sirt1 and PGC-1αin model group were up-regulated.Compared with model group,Sirt1 and PGC-1αexpression were inhibited in western medicine group.The protein expressions of Sirt1 and PGC-1αin astragalosideⅣhigh dose group were higher than those in astragalosideⅣlow and medium dose groups,the differences were statistically significant(P<0.05).Conclusion AstragalosideⅣcan improve adriamycin induced nephropathy in mice,attenuate the inflammatory response by up-regulating the expression of Sirt1 and PGC-1αprotein in renal tissue,improve renal function and delay the development of the disease,and its optimal dose is 80 mg/kg.