硫辛酸对人晶状体上皮细胞抗紫外线损伤作用的研究

Effect of α-lipoic ACID on protection from damages to human lens epithelial cells during ultraviolet rays irradiation

目的探讨硫辛酸在人晶状体上皮细胞(LECs)中抗紫外线损伤的作用。方法对人LECs进行培养和传代,当细胞达80%以上融合时进行不同强度的紫外线照射,照射剂量分别为37、73、112mW/cm2。分别于紫外线照射前、照射中和照射后用0.5mmol/L硫辛酸孵育细胞2h作为实验组,不加硫辛酸的细胞作为对照组。照射后的LECs用常规方法继续培养48h后进行固定,质量分数0.4%龙胆紫染色,自然风干后进行吸光度(A)值测定,计算细胞存活率并进行统计分析。结果正常培养的LECs24h完全贴壁,2～3d时70%以上的LECs达到融合。未用硫辛酸孵育的LECs组细胞连接疏松,细胞膜皱缩,可见部分漂浮细胞。硫辛酸孵育的LECs形态改变程度较轻。不同照射剂量的紫外线照射条件下各硫辛酸培养组LECs存活率差异有统计学意义(Fgroup=23.27,P<0.01;Fdose=1460.34,P<0.01)。紫外线照射的不同时间添加硫辛酸各组中LECs的生存率明显高于不添加硫辛酸组(P<0.05),而在紫外线照射剂量为半数致死量时其增强细胞存活率的作用最强。在照射剂量为半数致死量及1.5倍半数致死量时其细胞存活率依次为:照射后硫辛酸组>照射前硫辛酸组>照射中硫辛酸组>对照组。结论硫辛酸可以提高紫外线照射后的人LECs的存活率。提示硫辛酸可以减轻紫外线对人LECs的光损害。

Background Researches have shown that the irradiation of ultraviolet （UV） is one of causes to induce cataract.Some experimental studied about α-lipoic acid to prevent the UV-induced cataract have been performed,but few research in human lens has been reported so far.Objective The aim of this study was to determine whether α-lipoic acid enhants the survival of human lens epithelial cells（LECs） exposed to UV irradiation in vitro.Methods Human LECs line was cultured and passaged.0.5 mmol/L of α-lipoic acid was added in DMEM for 2 hours when the cell reached the subconfluence in the timing of pre-irradiation,intrairradiation and post-irradiation of UV with the irradiating doses of 37,73,112 mW/cm2,and then all the cells were consecutively cultured in the normal conditions for 48 hours.Cultured LECs were stained using methyl violet to evaluate the cell viability.Results The cultured LECs under the normal condition showed the complete adherence in 24 hours and over 70% cells achieved confluence in 2-3 days with the normal cellular structure.Loose of cell junction,shrinking of cell memberane and death of cells were found in only UV irradiation group.Mild abnormal changes were seen in addition of α-lipoic acid.Significant differences were found in LECs survival rate among different α-lipoic acid addition groups under the different doses of UV（Fgroup=23.27,P0.01;Fdose=1 460.34,P0.01）.The survival rates of LECs were significantly higher in pre-,intra-and post-irradiation＋α-lipoic acid groups in compared with without α-lipoic acid group （all P0.05）.The good survival statue of LECs under the different irradiation doses of UV was,in turn,post-UV＋α-lipoic acid group,pre-UV＋α-lipoic acid group,UV＋α-lipoic acid group,without α-lipoic acid group.Conclusion α-Lipoic acid protect LECs against the injury of UV and enhance the survival of human LECs in vitro.