Rac1在缺氧条件下培养的人视网膜色素上皮细胞的表达

Expression of Rac1 in cultured human retinal pigment epithelial cells under hypoxia

目的观察Rac1在缺氧条件下培养的视网膜色素上皮(retinal pigment epitheli-um,RPE)细胞的表达,以探讨其在脉络膜新生血管形成中可能的作用。方法将人RPE细胞在含有200μmol·L-1CoCl2的培养液内分别培养0.5h、1h、2h、4h、8h、12h和24h。运用免疫细胞化学方法及Western-blot技术检测缺氧条件下RPE细胞Rac1的表达及时相变化。常氧状态下培养的RPE细胞作为对照。结果缺氧条件下RPE细胞早期即有Rac1的表达,主要位于胞浆,随着缺氧时间的延长,阳性表达量上调,在8h达到高峰,12h开始下降。与常氧组对照,差异有统计学意义(P<0.05)。Western-blot分析结果与免疫细胞化学染色结果一致。结论Rac1在缺氧早期的RPE细胞中呈瞬时高表达,可能与脉络膜新生血管形成有关。

Objective To determine the expression, of Racl in cultured human retinal pigment epithelial （RPE） cells under hypoxia, and to discuss the possible effect of Racl on the formation of choroidal neovascularization. Methods The human RPE cells were cultured in DMEM contairting 200 μmol·L^-1CoCl2 for 0.5 hour, 1 hour,2 hours,4 hours,8 hours, 12 hours, and 24 hours, respectively. The RPE cells cultured under normoxia as controls. The expression of Racl was measured in both controls and hypoxia-induced RPE cells by immunocytochemical staining and Western blot. Results The expression of Racl was found in the RPE cells as early as 0.5 hour after induction of hypoxia with immunocytochemical staining, and it mainly localized in the cytoplasm. There was a time-dependently increase in the expression of Racl with the peak at 8 hours,and declined at 12 hours after exposure under hypoxia. The level of expression of Racl in the cells ctdtured under hypoxia showed a significant difference when compared to that in the controls （ P 〈0.05 ）. The Western blot analysis had a results similar to that of immunocytochemical staining. Conclusion The expression of Racl in RPE cells can be up-regulated in response to hypoxia. It may be associated with the formation of choroidal