摘要
目的:探讨白蛋白超载是否可以诱导近端肾小管上皮细胞(PTCs)向成肌纤维细胞转化(EMT)。方法:大鼠近端肾小管上皮细胞株NRK52E培养至70%融合或完全融合时,用不同浓度(0-30g/L)去脂牛血清白蛋白(dBSA)超载144h。NRK52E形态和结构改变用光镜和电镜观测。上皮细胞标记抗原E-钙黏蛋白和β-连环蛋白,以及成肌纤维细胞标记抗原α-平滑肌肌动蛋白(α-SMA)表达用免疫荧光和Western印迹法检测。结果:dBSA超载可诱导未完全融合NRK52E表达α-SMA,少数细胞变为长梭形,但α-SMA的表达不呈剂量依赖性。dBSA超载处理不能诱导完全融合的NRK52E表达α-SMA,细胞形态也无改变。dBSA超载完全或未完全融合NRK52E均不能抑制E-钙黏蛋白和β-连环蛋白表达,电镜显示这些细胞仍保持上皮细胞结构,包括微绒毛和紧密连接。结论:白蛋白超载可以诱导PTCs表达α-SMA,促进EMT,但不能诱导PTCs完全转化为成肌纤维细胞,细胞完全融合可抑制白蛋白超载诱导PTCs表达α-SMA。
AIM： To study whether albumin overload in proximal tubular epithelial cells （PTCs） induces epithelial to myofibroblast transdifferentiation （EMT）. METHODS： Rat renal proximal tubular cell line NRK52E was cultured on 6 well plates. When the cells reached 70% confluens or complete confluens, cells were serum starved for 24 h. Different concentrations of delipidated bovine serum albumin （dBSA）, ranging from 0 -30 g/L, were then added to the cells. The media was changed every 48 h until the end of 144 h. Cell shapes were monitored by light microscope during experiment. Cell structures were detected by electron microscopy. Epithelial cell markers： E - cadherin, β - catenin, and myofibroblast marker： α- smooth muscle actin （α -SMA） were detected by immunnfluorescent microscopy and Western blotting. RESULTS： dBSA overload induced the expression of α -SMA in sub -confluent NRK52E, and a few cells elongated, but the induced expression of α - SMA was not in a dose dependent manner, dBSA overload did not induce the expression of α-SMA in complete confluent NRK52E, cell shape did not change either, dBSA overload did not inhibit expression of E - cadherin or β - catenin both in sub - confluent and complete confluent NRK52E. The electron microscope showed that these cells retained epithelial phenotype, with microvilli and tight junction. CONCLUSION： Albumin overload induces PTCs expressing myofibroblast marker α - SMA and promotes EMT. However, complete EMT does not achieve. Complete confluens （cell- cell contacts） inhibits albumin induced α- SMA expression in PTCs.
出处
《中国病理生理杂志》
CAS
CSCD
北大核心
2008年第8期1575-1580,共6页
Chinese Journal of Pathophysiology
基金
广东省自然科学基金资助项目(No.06300772)
广东省医学科研基金资助项目(No.B2004033)
