色素上皮来源因子促进晶状体上皮细胞增殖机制初探

Mechanism of PEDF promoting lens endothelial cells proliferation

目的探究色素上皮来源因子(PEDF)对晶状体内皮细胞(LECs)增殖的调节作用及其相关机制。方法选择82例(82只眼)白内障患者收集中央晶状体前囊(直径5.0~5.5 mm),根据HE染色结果,分成晶状体上皮细胞低密度组和高密度组,每组20例。RT-PCR检测LECs中PEDF mRNA的相对表达情况。细胞体外实验中,分为加PEDF实验组和不加PEDF对照组,实验组培养基中加入50 ng/ml的PEDF培养72 h。用Annexin VFITC/7-AAD复染法进行流式细胞术分析LECs在G0和S期的细胞比例及细胞凋亡率。实时荧光定量PCR检测细胞内表达VEGF的mRNA。结果中央前囊下的LECs密度以及PEDF mRNA相对表达水平均低于高密度组,两组之间无统计学差异(P=0.168),PEDF实验组的凋亡率显著低于对照组的凋亡率(P<0.001)。PEDF实验组VEGF mRNA表达水平相较于对照组更低。结论在人眼中,PEDF可能是通过抗凋亡和降低VEGF表达来促进LECs的增值。降低LECs的PEDF浓度可能调节晶状体细胞的病理生理过程。

Objective To explore the role of pigment epithelium-derived factor（ PEDF） in the regulation of lens endothelial cells（ LECs） growth. Methods Central anterior lens capsule of 82 cataract patients（ diameter 5. 0 ~ 5. 5 mm）were collected. According to H. E. staining,samples were divided into 2 groups,one having low endothelial cell density and the other having high endothelial cell density. Each group had 20 cases. PEDF mRNA in LECs was detected by RTPCR. PEDF was added to cell assay at 50 ng/ml for 72 h. The ratio of G0 to S stage cells and the apoptosis rate of LECs were analyzed by Annexin V-FITC/7-AAD. Fluorescence quantitative PCR was used to detect mRNA VEGF expression.Results LECs density and PEDF mRNA expression were lower in high epithelial cell density groupbut no significant difference between the 2 groups were found. Apoptosis rate between the experimental group（ with added PEDF） and the control group was significant（ P 0. 001）. Expression of PEDF mRNA in the experimental group was lower. Conclusions PEDF promotes the proliferation of LECs by anti-apoptotic mechanism and by reducing the expression of VEGF. Decreasing PEDFlevels may be able to regulate the pathological physiological process of LECs.