【摘要】 目的　观察抗氧化剂N 乙酰 L 半胱氨酸 (NAC)和过氧化氢酶 (catalase ,CAT)对晶状体上皮细胞凋亡的抑制作用及对凋亡关键蛋白酶caspase 3酶活性的影响。方法　Sprayue Dawley(SD)大鼠 84只分成 4组 ,每组 2 1只。取晶状体于MEM培养液中培养 ,过氧化氢 (H2 O2 )组加入终浓度为 2mmol/L的H2 O2 ,对照组不加H2 O2 ,H2 O2 +NAC组及H2 O2 +CAT组除加入 2mmol/LH2 O2 外再分别加入 10 0 μmol/LNAC和 9× 10 5U/LCAT。培养 2 4h后观察晶状体透明度改变 ,透射电镜下观察细胞超微结构改变 ,流式细胞AnnexinV PI双染色法检测细胞凋亡率 ,并用Westernblot法分析caspase 3相对分子量为 2 0 0 0 0的活性亚单位的表达。结果　 2mmol/LH2 O2 作用 2 4h后可引起晶状体明显混浊 ,透射电镜下晶状体上皮细胞出现典型的凋亡形态学改变 ,细胞凋亡率上升为 (31 2± 3 3) % ,并伴随caspase 3酶活性增高 ;分别加入抗氧化剂NAC和CAT后 ,晶状体混浊度明显减轻 ,细胞凋亡率下降为(2 0 9± 3 2 ) %和 (15 0± 2 4 ) % (P <0 0 1) ,caspase 3酶活性均降低。结论NAC和CAT可有效抑制氧化损伤引起的晶状体混浊及上皮细胞凋亡 ,其抑制作用可能与降低caspase 3酶活性有关。更多还原

【Abstract】 Objective To investigate the effect of antioxidants N-acetyl-L-cysteine and catalase on H 2O 2-induced apoptosis of lens epithelial cells and the activity of caspase-3. Methods Rat lenses were incubated in MEM with 2 mmol/L H 2O 2 (H 2O 2 groups) or without H 2O 2 (control groups), antioxidants 100 μmol/L N-acetyl-L-cysteine and 900 U/ml catalase were used to block the oxidative injury of lens epithelial cells respectively. Lens opacification and apoptosis of lens epithelial cells were detected using transmission electron microscope and AnnexinV-PI staining after 24 hours incubation. The activity of caspase-3 was analyzed by Western blot at the same time. Results The observations revealed that 2 mmol/L H 2O 2 could apparently induce lens opacification and lens epithelial cell apoptosis in vitro, the apoptosis rate increased to (31.20±3.31)% after 24 hours incubation, which is also the time caspase-3 was activated. Treatment with N-acetyl-L-cysteine and catalase could inhibit lens opacification , apoptosis and caspase-3 activation induced by H 2O 2. The apoptosis rate decreased to (20.90±3.16)% and (15.02±2.41)% respectively ( P <0.01). Conclusion These data indicate that antioxidants N-acetyl-L-cysteine and catalase, possibly through regulation of the activity of caspase-3, can prevent lens opacification and apoptosis of lens epithelial cells.更多还原