摘要
目的:探讨NADPH氧化酶4(NADPH oxidase 4,NOX4)/瞬时受体电位阳离子通道C亚家族成员6(transient receptor potential channel subfamily C member 6,TRPC6)在糖尿病肾病足细胞损伤中的作用及其机制。方法:(1)将雄性Sprague-Dawley大鼠随机分为对照组、糖尿病肾病组、NOX4抑制剂(GKT137831)组、糖尿病肾病+GKTl37831组,每组8~10只。通过一次性腹腔注射链脲佐菌素(streptozotocin,STZ)(70 mg/kg)构建1型糖尿病模型,模型构建成功后腹腔注射GKT137831(5 mg/kg)。定期监测血糖和24 h尿白蛋白定量,并收集血液及肾脏组织。(2)使用小鼠肾小球足细胞为体外实验研究对象,细胞分为正常对照组、高糖组、GKTl37831组及高糖+GKTl37831组。体外高糖培养足细胞2周。使用NOX4抑制剂及使用小干扰RNA(small interfering RNA,siRNA)转染足细胞。免疫印迹、免疫组化及实时荧光反转录PCR(reverse transcription polymerase chain reaction,RT-qPCR)等技术检测NOX4和TRPC6表达水平。(3)使用荧光共聚焦显微镜观察高糖条件下足细胞线粒体形态变化,通过免疫印迹法检测足细胞中过氧化物酶体增殖物激活受体γ共激活因子1α(peroxisome proliferator-activated receptor gamma coactivator 1α,PGC1α)、线粒体转录因子A(mitochondrial transcription factor A,TFAM)、细胞色素C氧化酶亚单位I(cytochrome C oxidase subunit I,COX I)和COX IV蛋白表达水平。结果:(1)与正常对照组相比,糖尿病肾病大鼠肾小球显著肥大、基底膜增厚,系膜区增宽,尿白蛋白定量显著增加,免疫印迹及免疫组化结果显示肾组织NOX4蛋白表达水平升高,肾小球足细胞蛋白(nephrin)表达减少,间质细胞标志物如结蛋白(desmin)表达增加,TRPC6表达水平升高(P<0.05);使用GKT137831可降低肾组织desmin表达,保留肾小球nephrin,减少尿白蛋白定量(P<0.05)。(2)在体外足细胞实验中,高糖背景下,足细胞中NOX4和TRPC6表达上调(P<0.05);免疫荧光及免疫印迹检测结果显示GKT137831可减轻足细胞TRPC6和desmin表达,部分恢复nephrin表达(P<0.05);免疫印迹结果显示使用TRPC6 siRNA转染足细胞,可进一步促进GKT137831对足细胞的保护作用(P<0.05)。(3)荧光共聚焦显微镜显示高糖背景下足细胞线粒体形态受损,使用GKT137831及转染TRPC6 siRNA后,线粒体损伤得到部分恢复。免疫印迹结果显示高糖背景下足细胞PGC1α、TFAM、COX I和COX IV蛋白水平降低,使用GKT137831及转染TRPC6 siRNA后PGC1α、TFAM、COX I和COX IV表达水平升高(P<0.05)。结论:在糖尿病肾病的病理过程中,肾脏中NOX4表达增加,在一定程度上通过TRPC6通道介导足细胞的损伤,抑制NOX/TRPC6可改善足细胞线粒体功能障碍。这一发现为糖尿病肾病的临床诊疗提供了新的视角和策略。
AIM:To investigate the role and underlying mechanisms of NADPH oxidase 4(NOX4)/transient receptor potential channel subfamily C member 6(TRPC6)in the context of podocyte damage in diabetic nephropathya comprehensive investigative study was warranted.METHODS:(1)Male Sprague-Dawley rats were randomly divided into four distinct groups:a control group,a diabetic nephropathy group,a NOX4 inhibitor GKT137831-treated group,and a combined diabetic nephropathy with NOX4 inhibitor GKT137831-treated group,each consisting of 8~10 rats.The type 1 diabetes mellitus model was constructed via a single intraperitoneal injection of streptozotocin(STZ)(70 mg/kg),subse-quent to the successful induction of the model,GKT137831(at the dose of 5 mg/kg)was administered intraperitoneally.Regular monitoring of blood glucose levels was conducted,and urinary albumin excretion was quantified after 24 hours.Moreover,blood and kidney tissues were harvested for further analysis.(2)Mouse glomerular podocytes were divided into four distinct groups:a normal control group,a high glucose group,a GKT137831-treated group and a high glucose GKT137831-treated group.These podocytes were subsequently cultivated in vitro under high glucose conditions for 2 weeks.Thereafter,transfection of podocytes was carried out using NOX4 inhibitors and short interfering RNA targeting(siRNA)TRPC6.To detect the expression levels of NOX4 and TRPC6,a battery of techniques including Western blot,Immunohistochemistry,and reverse transcription polymerase chain reaction(RT-qPCR)were employed.(3)The morpho-logical changes of podocyte mitochondria under the condition of high glucose were observed by fluorescence confocal mi-croscopy,and the expression levels of peroxisome proliferator-activated receptor gamma coactivator 1α(PGC1α),mito-chondrial transcription factor A(TFAM),cytochromec oxidase subunit I(COX I)and cytochromec oxidase subunit IV(COX IV)in podocytes were assessed utilizing the Western blot technique.RESULTS:(1)Compared with normal con-trol group,mice with diabetic nephropathy manifested pronounced glomerular hypertrophy,thickening of basement mem-brane,expansion of the mesangial region,and an increased rate of urinary albumin excretion was observed.Analytical techniques such as Western blot and Immunohistochemistry showed a significant upsurge in the expression level of the NOX4 protein in kidney tissue,a diminished expression of glomerular podocyte protein(nephrin),an increased expression of interstitial cell markers(desmin),and an enhanced level of TRPC6 expression(P<0.05).GKT137831 was assoiated with a reduction in desmin expression in renal tissue,preservation of glomerular nephrin expression,and a decrease in uri-nary albumin excretion(P<0.05).(2)In vitro podocyte experiment,the expression of NOX4 and TRPC6 in podocyte was significantly increased in the context of high glucose(P<0.05).Findings from Immunofluorescence and Western blot showed that GKT137831 effectively diminished the expression levels of TRPC6 and desmin while partially rescuing neph-rin expression in podocellular cells(P<0.05).Western blot results showed that transfection of TRPC6 small interfering RNA could further promote the protective effect of GKT137831 on podiocytes.(3)Under high-glucose conditions,fluores-cence confocal microscopy revealed mitochondrial morphological damage in podocytes.However,therapeutic intervention with GKT137831 and transfection of TRPC6 siRNA partially rescued the mitochondrial structural integrity.Under high glucose conditions,immunoblot analysis demonstrated a marked decrement in the protein expression levels of PGC1α,TFAM,COX I,and COX IV in podocytes.Importantly,GKT137831 and the transfection of TRPC6 siRNA significantly upregulated the levels of PGC1α,TFAM,COX I,and COX IV(P<0.05).CONCLUSION:In the context of the patho-genesis of diabetic nephropathy,the increased expression of NOX4 in the kidneys contributes to podocyte damage,with the effect being partially mediated via the TRPC6 channel.Inhibiting the NOX4-TRPC6 signaling pathway has the potential to ameliorate mitochondrial dysfunction in podocytes.This finding offers novel perspectives and strategies for the clinical di-agnosis and treatment of diabetic nephropathy.
作者
岳汝驰
李惠敏
胡斌
宋志霞
YUE Ruchi;LI Huimin;HU Bin;SONG Zhixia(The First Clinical Medical College of China Three Gorges University,Yichang Central People's Hospital,Yichang 443000,China;Department of Nephrology,Renhe Hospital Affiliated to China Three Gorges University,Yichang 443000,China)
出处
《中国病理生理杂志》
北大核心
2025年第2期250-260,共11页
Chinese Journal of Pathophysiology
基金
湖北省自然科学基金资助项目(No.2021CFB379)
宜昌市医疗卫生项目专项基金资助项目(No.A21-2-002)。
