雌激素对缺氧损伤的人视网膜色素上皮细胞表达血管内皮细胞生长因子的影响

Effects of 17β-estradiol on the expression of vascular endothelial growth factor in cultured anoxia-injured human retinal pigment epitheliual cells

目的观察雌激素17β-雌二醇（17β-E2）对实验性缺氧损伤的人视网膜色素上皮（RPE）细胞血管内皮生长因子（VEGF）表达和乳酸脱氢酶（LDH）释放率的影响。方法用17β-E2和17β-E2拮抗剂三苯氧胺（Tamxifen,TAM）预处理RPE细胞后,氯化钴（CoCl2）制备RPE细胞缺氧损伤模型,分别采用比色法、细胞免疫化学法、逆转录聚合酶链式反应（RT-PCR）法检测定正常对照组、缺氧损伤组、17β-E2预处理组及17β-E2和TAM预处理组LDH释放率、VEGF蛋白表达、VEGFmRNA表达情况。结果缺氧损伤组RPE细胞较正常对照组LDH释放率增加,VEGFmRNA及蛋白表达增多（P〈0.05）。17β-E2预处理组与缺氧损伤组比较,VEGF的表达和LDH释放率明显降低（P〈0.05）;17β-E2作用被TAM阻断后,VEGF表达和LDH释放率增加,与缺氧损伤组比较差差无统计学意义（P〉0.05）。结论VEGF在缺氧损伤的人RPE细胞中表达增强;17β-E2可以抑制缺氧损伤后RPE细胞VEGF的表达,降低其LDH释放率,该作用可以为其拮抗剂TAM所阻断。

Objective To investigate the role of 17β estradiol on the expression of vascular endothelial growth factor （VEGF） and on the releasing rate of lactate dehydrogenase （LDH） in cultured anoxia-injured human retinal pigment epitheliual （RPE） cells. Methods Established the anoxia-injuried model of human RPE cells with Cobalt Chloride （CoCl2） after RPE cells were pretreated with 17β-E2 and tamoxife, 17β-E2 antagonist. The expression of VEGF mRNA was detected by reverse transcriptionpolymerase chain reaction technique （RT-PCR）. The cultured RPE cells were divided into four groups： normal control group, anoxia-injured group, 17β-E2 pretreatment group and 17β-E2 with tamoxifen pretreatment group. The releasing rate of LDH was detected by chromatometry. The expression of VEGF protein were detected by cellular immunohistochemistry. Results The expression of VEGF and LDH releasing rate were higher in anoxia-injured group than that in normal control group （P〈0.05）, and were lower in 17β-E2 pretreatment group than that in anoxia-injured group （P〈0.05）. When the effect of 17β- E2 was obstructed by tamoxifen, the expression of VEGF and LDH releasing rate increased but didn＇t differ much from which in anoxia-injured group （P〉0. 05）. Conclusion The expression of VEGF increases in anoxia-injured human RPE cells. 17β-E2 can down-regulate the expression of VEGF and decrease the releasing rate of LDH, which can be blocked by tamoxifen.