PKC信号传导通路对缺氧人视网膜色素上皮细胞表达VEGF的作用

目的 :探讨蛋白激酶C(PKC)信号传导通路对缺氧状态下培养的视网膜色素上皮 (retinalpigmentepithelium ,RPE)细胞表达VEGF的作用 .方法 :在缺氧状态下分别培养人RPE细胞 6 ,1 2和 2 4h ;将不同浓度的PKC激动剂佛波醇 1 2 豆蔻酰 1 3乙酸 (phorbol 1 2 myristate 1 3 acetate,PMA)及PKC抑制剂Chelerythrine分别加入人RPE细胞培养液 ,在缺氧状态下培养 2 4h .用免疫组化方法检测各组RPE细胞中VEGF的表达 ,经计算机图像处理 ,定量分析 .结果 :在缺氧状态下 ,RPE细胞对VEGF的表达较非缺氧组RPE细胞显著增加 (P <0 .0 1 ) ;较对照组 ,PMA可增强缺氧状态下RPE细胞VEGF的表达 (P <0 .0 1 ) ,Chelerythrine则减弱VEGF的表达 (P <0 .0 1 ) .结论 :缺氧诱导VEGF在RPE细胞中的表达 ,其信号传导途径部分是通过PKC通路实现的

Effect of PKC signaling pathway on VEGF expression in human retinal pigment epithelium cells under hypoxia

AIM: To study the effect of hypoxia on the expression of vascular endothelial growth factor (VEGF) in human retinal pigment epithelium (RPE) cells and the role of protein kinase C (PKC) signal transduction pathway in this event. METHODS: The passaged human RPE cells were cultured under hypoxia for 6, 12, 24 h. Different concentrations of phorbol 12 myristate 13 acetate (PMA) (a PKC activator) and Chelerythrine(a PKC inhibitor) were added to the medium of cultured RPE cells under hypoxia for 24 h. VEGF protein expression was determined with immunohistochemical assay, and quantitative analysis was performed after image processing with computer. RESULTS : The expression of VEGF in human RPE cells under hypoxia increased than that in normoxic group at every time point( P <0.01); Compared with control group under hypoxia, the expression of VEGF increased after the administration of PMA( P <0.01)and decreased after the treatment of Chelerythrine ( P <0.01). CONCLUSION: PKC activation is an essential component of the signal transduction pathway to increase the VEGF expression in RPE cells.