磷脂酰肌醇-3激酶信号通路在缺氧诱导的人视网膜色素上皮细胞VEGF表达中的作用

Phosphatidylinositol 3-kinase signal tran- sduction pathway in human retinal pigment epithelium cell VEGF expression

目的:探讨磷脂酰肌醇-3激酶(phosphatidylinositol3-ki-nase,PI3K)信号转导通路对缺氧诱导的视网膜色素上皮(retinalpigmentepithelium,RPE)细胞表达VEGF的影响。方法:利用CoCl2建立培养的人RPE细胞缺氧模型,分为单纯缺氧组和30μmol/LPI3K特异性阻断剂LY294002阻断处理组,在缺氧条件下分别培养0,1,4,8,12和24h。细胞免疫荧光法检测磷酸化PI3K表达水平;酶联免疫吸附试验(enzymelinkedimmunosorbentassay,ELISA)检测RPE细胞上清中VEGF的含量。结果:缺氧刺激1,4,8,12和24h,RPE细胞膜上PI3K磷酸化表达水平逐渐增高(P<0.05);随缺氧时间延长,RPE细胞上清液中VEGF含量逐渐增加(P<0.05);LY294002处理组VEGF含量显著低于对照组(P<0.05)。结论:PI3K信号转导通路参与了缺氧引起的人RPE细胞VEGF表达的调控。

AIM： To investigate the role of phosphatidylinositol 3-kinase （PI3K）signal transduction pathway in vascular endothelial growth factor（VEGF）expression in cultured human retinal pigment epithelial（RPE） cells under hypoxia. METHODS： Cobalt chloride was used to establish a model of hypoxia and RPE cells treated with/without the specific inhibitor of PI3K, LY294002 at the concentration of 30μmol/L. The level of phosphophorylation PI3K was observed with immunofluorescence staining. The amounts of VEGF in the RPE-conditioned supernatant were measured using enzyme linked immunosorbent assay. RESULTS： Under hypoxia, the level of PI3K phosphophory-lation in RPE cells was time-dependently increased in cell membrane （P〈0.05）. The amount of VEGF in RPE cell supernatant was significantly increased in time-dependent manner under hypoxia （P〈0.05）, and that in LY294002-treatecl groups was lower than the controls （P〈0.05）. CONCLUSION： PI3K signal transduction pathway could partly play a positive role in VEGF expression induced by hypoxia in RPE cells.