PPARγ受体在大鼠缺氧性肾小管上皮细胞损伤中的表达及意义

Expression of Peroxisome proliferator-activated receptor-γ in hypoxia damage of renal tubular epithelial cells and its significance

目的探讨过氧化物酶体增殖物激活受体γ(PPARγ)在大鼠缺氧性肾小管上皮细胞(RTEC)损伤中的表达及意义。方法将体外传代培养的大鼠RTEC随机分为正常对照组、缺氧模型组、罗格列酮(RGZ)组和GW9662组。RGZ组加入15μmol/L RGZ,GW9662组加入25μmol/L GW9662,将缺氧模型组、RGZ组、GW9662组放入真空罐中制作RTEC缺氧模型。正常对照组细胞不做处理。造模36 h后,采RT-PCR法和Western blot法检测各组RTEC PPARγ、转化生长因子-β1(TGF-β1)的mRNA及蛋白表达。结果与正常对照组比较,缺氧模型组、RGZ组、GW9662组RTEC PPARγmRNA表达显著升高、蛋白表达显著降低(P均<0.05);与缺氧模型组相比,RGZ组RTEC PPARγmRNA表达降低,GW9662组表达上升(P均<0.05)。与正常对照组比较,缺氧模型组、RGZ组、GW9662组RTEC TGF-β1mRNA表达显著降低、蛋白表达显著升高(P均<0.05);与缺氧模型组比较,RGZ组RTEC TGF-β1mRNA表达上升,GW9662组表达降低(P均<0.05)。相关性分析显示,缺氧性RTEC损伤中PPARγ的蛋白表达与TGF-β1的蛋白表达呈显著负相关(r=-0.91,P<0.05)。结论 PPARγ蛋白的低表达可能参与了缺氧性RTEC损伤的发生;RGZ可能通过上调PPARγ蛋白的表达而减轻缺氧性RTEC损伤。

Objective To explore the expression and effects of Peroxisome proliferator-activated receptor-γ（ PPARγ） in hypoxic damage of renal tubular epithelial cells （RTEC）.Methods Rat＇s proximal tubular epithelial cell line （NRK-52E） was subcultured in vitro and randomly assigned into normal group, hypoxia model group, Rosiglitazone （RGZ） group and GW9662 group.RGZ （15μmol/L） and GW9662 （25μmol/L） were administered to RGZ group and GW9662 group respectively.The hy-poxia model group, RGZ group and GW9662 group were put into vacuum tank to establish the model of hypoxia/reperfusion-in-duced RTEC injury.The normal group did not make any processing.The expressions （mRNA and protein） of PPARγand trans-forming growth factor-β1（TGF-β1） in RTEC were detected by RT-PCR and Western blot 36 h after establishing models.Results Compared with normal group, the mRNA and protein expressions of PPARγin the hypoxia model group, RGZ group and GW9662 group were decreased;The expressions of PPARγin the RGZ group was elevated, and the indicator was lowered in the GW9662 group when compared with hypoxia model group （all P〈0.05）.Compared with normal group, the mRNA and protein expressions of TGF-β1 in the hypoxia model group, RGZ group and GW9662 group were increased;The expression of TGF-β1 in the RGZ group was decreased , the level of the indicator in the GW9662 group was increased when comparing with hypoxia model group （all P〈0.05）.Correlation analysis showed that the protein expression of PPARγwas negatively correlated with TGF-β1 in NRK-52E cell（P〈0.05）.Conclusion The lowered expression of PPARγmay be involved in hypoxia damage of RTEC;RGZ may alleviate the injury by elevating the expression of PPARγ.