基于线粒体动力学探讨雷公藤多苷对IgA肾病大鼠的作用机制

Exploration of mechanism of action of tretinoin polyglucoside in rats with IgA nephropathy based on mitochondrial dynamics

目的探讨雷公藤多苷(multi-glycosides of Tripterygium wilfordii,GTW)对IgA肾病(IgA nephrophathy,IgAN)大鼠线粒体动力学相关蛋白的影响及肾脏保护作用机制。方法SPF级雄性SD大鼠,随机分为空白组、造模组、醋酸泼尼松组(prednisone acetate tablets,PAT;6.25 mg·kg·d^(-1))、GTW组(6.25 mg·kg·d^(-1))。采用“牛血清白蛋白(BSA)+四氯化碳(CCl 4)+脂多糖(LPS)”法建立IgAN大鼠模型。收集大鼠24 h尿液检测尿蛋白总量(24 h-UTP)并对尿液中红细胞计数,采集大鼠腹主动脉血液生化检测血清白蛋白(ALB)、谷丙转氨酶(ALT)、尿素氮(BUN)、血肌酐(Scr)水平;利用免疫荧光和HE染色观察肾脏组织病理;RT-PCR法和Western blot法检测大鼠肾组织中调控线粒体分裂融合的关键蛋白:动力相关蛋白1(Drp1)、线粒体融合蛋白1(Mfn1)和线粒体融合蛋白2(Mfn2)及PTEN诱导的假定激酶1(Pink1)mRNA及蛋白表达水平。结果GTW明显降低IgAN大鼠尿红细胞计数和24 h-UTP,降低血清ALT、BUN、Scr水平,提高血清ALB水平,改善IgAN大鼠肾组织病理状态,提高肾组织中Mfn1、Mfn2、Pink1蛋白和mRNA表达水平,降低Drp1蛋白和mRNA表达水平。结论GTW可能通过促进Mfn1、Mfn2、Pink1及降低Drp1的表达,调节线粒体结构,维持线粒体动力学动态平衡,以降低尿红细胞计数和蛋白尿,改善肾脏功能。

Aim To investigate the effects of multi-glycosides of Tripterygium wilfordii(GTW)on mitochondrial dynamics-related proteins and the mechanism of nephroprotective effects in IgA nephrophathy(IgAN)rats.Methods SPF grade male SD rats were randomly divided into the Control group,modelling group,prednisone group(6.25 mg·kg·d^(-1))and GTW group(6.25 mg·kg·d^(-1)).The IgAN rat model was established by the method of“bovine serum albumin(BSA)+carbon tetrachloride(CCl 4)+lipopolysaccharide(LPS)”.The total amount of urinary protein(24 h-UTP)and erythrocyte count in urine were measured in 24 h urine.Blood biochemistry of serum albumin(ALB),alanine aminotransferase(ALT),urea nitrogen(BUN),and creatinine(Scr)were measured in abdominal aorta of the rats;immunofluorescence and HE staining were used to observe the histopathology of the kidneys;RT-PCR and Western blotting were used to detect the mRNA and protein expression levels of key proteins regulating mitochondrial division and fusion:dynamin-related protein 1(Drp1),mitochondrial fusion protein 1(Mfn1),and mitochondrial fusion protein 2(Mfn2),and PTEN-induced putative kinase 1(Pink1),in the kidney tissue of rats.Results GTW significantly reduced urinary erythrocyte count and 24 h-UTP,decreased serum ALT,BUN and Scr levels,increased serum ALB levels,improved renal histopathological status in IgAN rats,increased the protein and mRNA expression levels of Mfn1,Mfn2,and Pink1,and decreased the protein and mRNA expression levels of Drp1 in renal tissues.Conclusions GTW may regulate mitochondrial structure and maintain the dynamic balance of mitochondrial dynamics by promoting the expression of Mfn1,Mfn2,Pink1 and decreasing Drp1.This may result in a reduction in urinary erythrocyte counts and proteinuria,and an improvement in renal function.