背景 氧化应激诱导的晶状体上皮细胞( LECs)凋亡与c-Jun氨基末端激酶(JNK)细胞信号通路有关；槲皮素能抑制JNK细胞信号通路并且有显著的抗氧化作用,但其对高压氧诱导的人LECs损伤有无保护作用有待研究. 目的 研究高压氧诱导人LECs凋亡的作用及槲皮素对高压氧处理的人LECs的保护作用,探讨JNK细胞信号通路在上述过程中的作用.方法 人LECs细胞系SRA01/04在MEM培养基中进行培养,传至第3代进行实验.实验细胞分为空白对照组、高压氧组(体积分数99％ O2+体积分数1％ CO2)、高压氧+SP600125组和高压氧+槲皮素组,实验前2h分别在后2个组人LECs培养基中加入20μmol/L JNK2特异性抑制剂(SP600125)或1μmol/L槲皮素预孵育,除空白对照组外,其他3个组于588 kPa高压氧舱处理6h后收集人LECs.应用MTT法检测各组人LECs的细胞活力,以570 nm处吸光度(A)值表示.用流式细胞仪以Annexin V-FITC试剂盒检测人LECs处理后各组细胞的凋亡率,通过Western blot法检测各组人LECs中JNK/p-JNK、c-Jun/p-c-Jun、caspase-3、caspase-9的蛋白表达情况. 结果 实验6h后,高压氧组、高压氧+SP600125组、高压氧+槲皮素组人LECs活力分别为0.450±0.083、0.654±0.079、0.649±0.090,明显低于空白对照组(0.835±0.082),差异均有统计学意义(P=0.001)；高压氧+SP600125组、高压氧+槲皮素组人LECs活力明显高于高压氧组(P=0.003、0.002).高压氧组、高压氧+SP600125组、高压氧+槲皮素组人LECs凋亡数分别为19.77±1.44、8.45±0.93、7.79±0.78,明显高于空白对照组的3.17±0.74,差异有统计学意义(P=0.000)；高压氧+SP600125组、高压氧+槲皮素组人LECs细胞凋亡数明显少于高压氧组,差异均有统计学意义(P=0.000).同时,高压氧组人LECs中p-JNK、p-c-Jun、caspase-3和caspase-9蛋白的表达量明显高于空白对照组,差异均有统计学意义(P=0.000),而高压氧+SP600125组、高压氧+槲皮素组人LECs中p-JNK、p-c-Jun、caspase-3和caspase-9蛋白的表达量明显低于高压氧组,差异均有统计学意义(P＜0.05). 结论 JNK细胞信号通路在高压氧诱导的人LECs凋亡发生发展中起重要作用,SP600125和低浓度的槲皮素能抑制JNK细胞通路和细胞内源性凋亡途径,减轻高压氧引起的人LECs损伤.%Background Oxidative stress-induced apoptosis of human lens epithelial cells (LECs) is associated with c-Jun N terminal kinase (JNK) pathway.Quercetin possesses the antioxidation by inhibiting the JNK pathway.However,whether quercetin can protect LECs from the oxygen-induced damage is still not proved.Objective This study attempted to invatigate the effects and its mechanism of quercetin against hyperbaric oxygeninduced LECs apoptosis. Methods Human LECs line SRA01/04 was cultivated and passaged in MEM medium containing 10％ fetal bovine serum and 0.5％ non-essential amino acids for 2 hours,with or without 20 μmol/LSP600125 or 1 μmol/L quercetin prior to exposure to hyperbaric oxygen.Each exposure session remained 6 hours in 99％ O2 and 1％CO2 with a pressure chamber at 588 kPa.The viability of human LECs was detected by MTT.Cell apoptosis was assessed by flow cytometer using Annexin V-FITC apoptosis detection.The expression of JNK/p-JNK,c-Jun/p-c-Jun,caspase 3 and caspase 9 were detected by Western blot. Results LECs viability (A570 ) was 0.835 ±0.082,0.450±0.083,0.654±0.079,0.649±0.090 respectively in the blank control group,hyperbaric oxygen exposed group,hyperbaric oxygen+SP600125 group and hyperbaric oxygen+quercetin group.The A570 in the hyperbaric oxygen exposed group was significantly lower than the blank control group ( P =0.000),but those in hyperbaric oxygen + SP600125 group and hyperbaric oxygen+quercetin group were significantly higher than the hyperbaric oxygen exposed group ( P =0.003,0.002 ).The numbers of apoptosis cells were 3.17 ±0.74,19.77 ± 1.44,8.45 ±0.93,7.79 ±0.78 respectively in the blank control group,hyperbaric oxygen exposed group,hyperbaric oxygen+SP600125 group and hyperbaric oxygen+quercetin group.Apoptotic LECs were significantly increased in the hyperbaric oxygen exposed group compared with the blank control group ( P=0.000),but those in the hyperbaric oxygen+SP600125 group and hyperbaric oxygen+quercetin group were significantly reduced in comparison with hyperbaric oxygen exposed group (both P=0.000).In additional,expressions of p-JNK,p-c-Jun,caspase 3 and caspase 9 proteins in the cells were elevated in the hyperbaric oxygen exposed group compared with the blank control group (all P =0.000 ),however,those in the hyperbaric oxygen + SP600125 group and hyperbaric oxygen + quercetin group were declined when compared with the hyperbaric oxygen exposed group( all P＜0.05 ). Conclusions JNK pathway is involved in the apoptotic procedure of human LECs induced by oxygen stress.SP600125 and certain concentration of quercetin can interdict the JNK signal pathway and endogenous apoptosis of LECs and further alleviate hyperbaric oxygen-induced damage of LECs.
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