过氧化氢诱导人视网膜色素上皮细胞转录和表达促红细胞生成素的研究

Hydrogen peroxide induces expression and transcription of erythropoietin in the bnman retinal pigment epithelium cells

目的研究不同浓度的过氧化氢诱导人视网膜色素上皮（RPE）细胞转录和表达促红细胞生成素（EPO）的现象并探讨其发生机制。方法原代培养人胚胎RPE细胞，经鉴定后，分别应用0、200、400、600、800μmol／L浓度的过氧化氢作用6h，造成RPE细胞不同程度的氧化应激，测定细胞内超氧化物歧化酶（SOD）和丙二醛（MDA）含量；采用半定量RT-PCR法检测RPE细胞氧化应激中EPO在转录水平的表达变化；免疫组织化学法检测EPO在RPE细胞中的表达部位和表达变化。结果过氧化氢导致RPE细胞内SOD含量下降，MDA含量升高。半定量RT-PCR法检测结果显示过氧化氢诱导EPOmRNA表达量增加，并在一定范围内随着过氧化氢浓度的增高而增加，在600μmol／L过氧化氢组EPOmRNA表达量达最高值，之后随着浓度的上升而下降。免疫组织化学染色法检测结果显示过氧化氢可以诱导人RPE细胞EPO表达增强，并在一定范围内随着过氧化氢浓度的增高而增强，在600μmol／L过氧化氢组EPO表达量达到高峰。结论过氧化氢导致的氧化应激可以诱导人RPE细胞转录和表达EPO，EPO的表达量与RPE存活和耐受程度有关。

Objective To investigate the expression of erythropoietin （EPO） in human fetal retinal pigment epithelium （hfRPE） cells exposed to oxidative stress induced by hydrogen peroxide （H2O2 ） and to study the mechanisms. Methods The hfRPE cells were isolated, cultured and identified. The content of malondialdehyde （MDA） and the activity of superoxide dismutase （SOD） of the hfRPE cells were examined. The changes of level of mRNA and protein of EPO in hfRPE cells exposed to oxidative stress were measured by semi-quantitative RT-PCR and immunocytochemical staining techniques. Results H2O2 could increase the content of MDA and inhibit the activity of SOD in hfRPE cells. RT-PCR detected a significant increase of EPO mRNA level in cultured hfRPE cells exposed to oxidative stress. The level of EPO mRNA in the hfRPE cells reached a peak when exposed to 600 μmol/L H2O2, then decreased after exposing to 800 μmaol/L H2O2. The immunocytochemical study detected that the changes of the level of EPO protein were similar to that of EPO mRNA. Conclusion Oxidation stress by exposed to H2O2 induces significant increase of EPO expression of hfRPE cells. Expression of EPO may be related to the survival and tolerance of hfRPE cells.