牛磺酸对TGF-β1诱导的人RPE细胞凋亡的抑制作用

目的:研究牛磺酸对TGF-β1诱导体外培养人视网膜色素上皮(RPE)细胞凋亡的抑制效应及其机制。方法:体外原代培养正常RPE细胞。设置正常对照组(无药物处理);损伤组(1μg/L TGF-β1处理RPE细胞);牛磺酸保护组(10 mmol/L和20 mmol/L牛磺酸预先处理RPE细胞后再加入1μg/L TGF-β1)。利用流式细胞仪检测RPE凋亡率;RT-PCR检测RPE细胞Fas mRNA表达情况;通过Fur-2/AM测量细胞内游离钙离子浓度。结果:TGF-β1能够诱导RPE细胞凋亡,细胞Fas mRNA表达明显增高,而且细胞内钙离子浓度升高;牛磺酸可以显著地降低TGF-β1诱导的RPE细胞的凋亡率,呈浓度依赖性,Fas mRNA的表达随细胞内钙离子浓度的降低而减少。结论:牛磺酸可以抑制TGF-β1所致体外培养RPE细胞的凋亡;其作用机制可能与降低细胞内钙离子浓度进而影响Fas通路发挥诱导细胞凋亡效应有关。

Inhibitory Effect of Taurine on TGF-beta1 Induced Apoptosis of Primary-cultured Human Retinal Pigment Epithelial Cells

Objective: To study the inhibitory effect and potential mechanism of taurine on the TGF-β1-induced apoptosis of primary-cultured human retinal pigment epithelial(RPE) cells.Methods: The RPE cells were attained by primary culture from healthy adult donators died of accidents.The RPE cells were treated by taurine(10 mmol/L and 20 mmol/L,respectively) for 6 hours and then by TGF-β1(1 μg/L) for 24 hours in two taurine groups,or treated by TGF-β1(1 μg/L) alone for 24 hours in TGF group.The apoptosis rates of RPE were measured with flow cytometry.The expression of Fas mRNA of RPE was determined by RT-PCR,and the concentration of free intracellular calcium was measured by Fur-2/AM.Results: TGF-β1 could induce the apoptosis of RPE cells,which was related with high expression of Fas mRNA and increase of free intracellular calcium of RPE cells.Taurine showed dosage-dependent inhibitory effect on the TGF-β1-induced apoptosis of RPE. Furthermore,the expression of Fas mRNA decreased with the decrease of free intracellular calcium after the pre-treatment of taurine.Conclusion: Taurine can inhibit the TGF-β1-induced apoptosis of human retinal pigment epithelial cells,which may be associated with the decreased expression of Fas mRNA resulted from its effect on decreasing the concentration of free intracellular calcium.