地塞米松对血管紧张素Ⅱ致肾小球内皮细胞单层通透性、F-肌动蛋白变化的影响

Effects of dexamethasone on changes of monolayer permeability and F-actin of glomerular endothelial cells induced by Angiotensin Ⅱ

目的探讨血管紧张素Ⅱ(AngⅡ)诱导肾小球内皮细胞(GENC)损伤时的单层通透性、F-肌动蛋白(F-actin)的变化及它们之间的关系,并探讨地塞米松对上述变化的影响。方法在体外分离、培养大鼠GENC的基础上,用二室弥散系统检测AngⅡ对GENC单层通透性的影响,用流式细胞仪检测AngⅡ对GENC的F-actin分布及量的影响。结果AngⅡ组作用6、12 h的GENC单层通透率均较正常对照组显著增加(P值分别<0.05、0.01),AngⅡ+地塞米松组则较AngⅡ组显著降低(P值均<0.01)。AngⅡ组作用6、12 h的GENC的F-actin的荧光强度均较正常对照组显著降低(P值均<0.01),AngⅡ+地塞米松组则较AngⅡ组显著升高(P值均<0.01)。GENC单层通透率与F-actin呈负相关(r=-0.901,P<0.01)。结论AngⅡ可引起GENC的单层通透性增高,F-actin解聚,且GENC单层通透性增高的机制可能与F-actin解聚密切相关。地塞米松可减轻AngⅡ对GENC的损伤,起保护作用。

Objective To investigate the changes of monolayer permeability and F-actin of glomerular endothelial cells （GENCs） induced by Angiotensin Ⅱ （Ang Ⅱ ）, and to study the influence of dexamethasone. Methods GENCs were isolated and cultured from Wistar rat in vitro. The influence of Ang Ⅱ on the monolayer permeability, F-actin of GENCs were observed using diffusion of bovine serum albumin/（biotin-BSA） across the monolayer. The F-actin expression was evaluated by flow cytometry. Results Exposure to Ang Ⅱ for 6 and 12 h significantly increased the permeability of GENC monolayer compared with normal control group （ P〈 0.05 or 0.01）; the permeability of Ang Ⅱ ＋ dexamethasene group was significantly lower than that of the Ang Ⅱgroup （ P〈0.01 ）. Exposure to Ang Ⅱ for 6 and 12 h significantly decreased the intensity of F-actin signal compared with the normal control group （P〈0.01 ）, and the intensity of Ang Ⅱ ＋ dexamethasone group was significantly higher than that of the Ang Ⅱ group （ P〈0.01 ）. The monolayer permeability was negatively correlated with F-actin （r = -0.901, P〈0.01）. Conclusion Ang Ⅱ can increase the permeability of GENC monolayer and depolymerize F-actin; the increase of permeability might be related to the depolymerization of F-actin. Dexamethasone can relieve Ang IT-induced damage to GENCs. （Shanghai Med J, 2009, 32; 236-239）