目的：研究p75 NTR受体在视网膜色素上皮细胞(retinal pigment epithelial cells，RPE)氧化损伤过程中的作用及机制。

方法：将转染p75 NTR受体的RPE细胞作为实验组，未转染的RPE细胞作为对照组。BrdU检测法检测细胞增殖活性； PI/Annexin V-FITC双染法检测细胞凋亡率； 激光显微镜观察细胞内ROS的表达情况； 流式细胞仪检测细胞内ROS、线粒体标志物、细胞色素C表达水平； Western blot法检测细胞中Fas蛋白、裂解Caspase-3、VEGF165蛋白的表达水平。

结果：随着p75 NTR受体转染时间的延长，实验组RPE细胞的增殖活性呈逐渐降低趋势，各转染时间点的RPE细胞增殖活性比较，差异有统计学意义(P<0.05)； 实验组各转染时间点的RPE细胞增殖活性均明显低于对照组，差异均有统计学意义(P<0.05)。随着转染时间的延长，实验组RPE细胞凋亡率呈逐渐增加趋势，各转染时间点的RPE细胞凋亡率比较，差异有统计学意义(P<0.01)； 实验组各转染时间点的RPE细胞凋亡率均明显高于对照组，差异均有统计学意义(P<0.01)。实验组ROS荧光信号明显强于对照组。流式细胞仪检测结果显示，实验组RPE细胞中ROS、细胞色素C水平均明显高于对照组，线粒体标志物水平明显低于对照组，差异均有统计学意义(P<0.01)。Western blot 法检测结果表明，实验组细胞内Fas蛋白、Caspase-3、VEGF₁₆₅蛋白的表达水平均明显高于对照组，差异均有统计学意义(P<0.01)。

结论：p75 NTR受体高表达可导致RPE细胞线粒体发生损伤，同时促进细胞凋亡，最终导致脉络膜新生血管的形成，表明p75 NTR受体可能是导致RPE细胞发生损伤的因素之一。

METHODS: The NTR p75 receptor was used to transfer the retinal pigment epithelium cells as the experimental group, and the non transfected retinal pigment epithelium cells were used as control group. The BrdU test detected the proliferation of two groups of cells. The rate of apoptosis in two sets of apoptosis was measured by PI/in the V-FITC double dye method. The laser microscope detects the ROS levels within the cell. The flow cytometer detected the levels of ROS, mitochondrial markers, cytochrome C expression in RPE cells. The Western blot method detected the expression level of Fas, Caspase-3, and VEGF165 in RPE cells.

RESULTS: The RPE cell proliferation activity was gradually decreasing(P<0.05)with the extension of the p75 NTR receptor transfer time in experimental group. The RPE cell proliferation activity in each transfection point was significantly lower in experimental group than in the control group(P<0.05). The percentage of RPE apoptosis was gradually increased with the extension of transfection time in experimental group(P<0.01). The percentage of RPE cell apoptosis in the experimental group was significantly higher than the control group(P<0.01). ROS fluorescence was significantly better in the experimental group than the control group. Flow cytometry instrument method, according to the results of the experimental group PRE ROS levels in the cell, cytochrome C was significantly higher than control group(P<0.01), RPE cell mitochondria marker levels significantly lower than the control group(P<0.01). The results of the Western blot method showed that the expression levels of VEGF165, Fas and Caspase-3 were significantly higher in the experimental group than in the control group(P<0.01).

CONCLUSION: The over expression of p75 NTR receptor could lead to damage of mitochondria in retinal pigment epithelium cells, but it could also promote the apoptosis reaction, eventually it led to the formation of choroidal neovascularization, so it could be speculated that p75 NTR receptor is the damage factors of retinal pigment epithelium.