YVAD-cmK及DEVD-CHO对培养的人视网膜色素上皮细胞光损伤的影响

The effect of DEVD-CHO and YVAD-cmK on apoptosis induced by visible light in cultured human RPE cells

目的 观察半胱天冬酶(caspase-3)选择性抑制剂天冬氨酸-谷氨酸-缬氨酸-天冬氨酰胺醛(Asp-Glu-Val-Asp-CHO,DEVD-CHO),及caspase-1选择性抑制剂酪氨酸-缬氨酸-丙氨酸-天冬氨酰胺(Tyr-Val-Ala-Asp-cmK,YVAD-cmK)对可见光诱导的培养的人视网膜色素上皮(RPE)细胞凋亡的影响。方法 用(2000±500)lx的白色荧光灯光源,照射培养的人RPE细胞。在培养液中加入YVAD-cmK和DEVD-CHO,利用荧光素标记的连接素V/碘化丙锭双染色流式细胞测定观察RPE细胞的凋亡情况。结果 本研究模型下,DEVD-CHO预处理组的细胞凋亡及坏死与无光照组相比,差异无显著性(P>0.05),与光照组及YVAD-cmK预处理组相比,细胞存活数增高,差异有显著性(P<0.05)。而YVAD-cmK组与无光照组比较,其结果与单纯光照组一样,表现出细胞的明显损伤(P<0.05)。结论 可见光诱导培养的人RPE细胞凋亡的发生机制中,可能不涉及casrpase-1的作用。外源性的caspase-3抑制剂(DEVD-CHO)对RPE细胞光性损伤有一定的保护作用。

Objective To observe the role of DEVD-CHO and YVAD-cmK ( the selective inhibitor of caspase-3 and caspase-1 .respectively) in apoptosis process of human RPE cells in vitro induced by visible light. Methods Cultured human RPE cells were exposed to (2000 ± 500) Lux cold white light, and exogenous YVAD-cmK and DEVD-CHO were added into medium. Cell apoptosis and necrosis were detected by Annexin V-FITC/PI labeling and flow cytometry. Results No significant difference was found between DEVD-CHO pre-treated group and unexposed group in apoptotic and necrotic percentages ( P > 0.05). Survival rate of cells were significant higher in DEVD-CHO pre-treated groups in comparison to YVAD-cmK group and light exposure group(P < 0. 05). The damage extent of RPE cells was comparable in YVAD-cmK group and light-exposure group. Conclusions The apoptotic mechanisms of cultured human RPE cells induced by visible light may be not associated with caspase-1. Human RPE cells exposed to visible light can be rescued by using exogenous DEVD-CHO in vitro.