NF-κB/I-κB在过氧化氢所致心肌细胞损伤中的作用机制  

The Mechanism of Action of NF-κB / I-κB in Hydrogen Peroxide Induced Cardiomyocyte Injury

作　　者：涂自智[1] 肖卫民[1] 刘梅冬[1] 尢家騄[1] 肖献忠[1] 

机构地区：[1]中南大学湘雅医学院病理生理学教研室,湖南长沙410078

出　　处：《医学临床研究》2004年第8期833-836,共4页Journal of Clinical Research

基　　金：国家自然科学基金 ( 3 0 0 0 0 0 69) ;国家 973重点项目 (G2 0 0 0 0 5 690 8);教育部博士点专项基金 ( 2 0 0 2 0 5 3 3 0 3 2 )资助

摘　　要：【目的】探讨氧化应激损伤心肌细胞的分子机制。【方法】采用 0 .5mmol/L过氧化氢 (hydrogenperoxide ,H2 O2 )作用于原代培养的新生大鼠心肌细胞 ;采用胎盘蓝染色检测细胞死亡率 ,乳酸脱氢酶 (LDH)测定试剂盒检测其释放率 ,末端标记检测细胞凋亡 ,Westernblot检测NF κB内源性抑制蛋白I κB (inhibitorκB ,I κB)含量 ,免疫组化检测NF κB在细胞内的分布情况。【结果】①H2 O2 损伤 3h ,心肌细胞死亡率和LDH释放率均较对照组明显升高 (P <0 .0 1) ;②H2 O2 损伤 2 4h ,出现大量心肌细胞凋亡 ;③I κB在H2 O2 损伤 5min即减少 ,15min时减至最低 ,而后逐渐恢复 ;④H2 O2 损伤 0 .5h可引起心肌细胞中NF κB从胞浆向胞核移位 ,2h后复位 ;⑤与单纯损伤组比 ,NF κB抑制剂吡咯烷二硫代氨基甲酸盐 (pyrrolidinedithiocarbamate,PDTC)能明显降低心肌细胞LDH释放率 (P <0 .0 1)。【结论】在H2 O2 所致心肌细胞损伤中 ,既有坏死 ,又有凋亡的发生 ,而NF κB/I κB信号通路的激活可能介导了H2 O2 所致的心肌细胞损伤。Objective To investigate the molecular mechanism of oxidative stress in cardiomyocyte injury.The neonatal rat cardiomyocytes cultured in primary generation were injured by exposure to 0.5 mmol/L hydrogen peroxide (H 2O 2) for different durations. The cell death rate was detected by placental blue staining , the release rate of lactate dehydrogenase (LDH) was measured with its reagent kit and apoptosis was checked by terminal deoxynucleotidyl transferase-mediated biotin-dUTP nick-end labeling (TUNEL),respectively. The contents of endogenous inhibitory protein for NF-kB ( i.e. I-κB) was detected by Western-blotting, while the translocation of NF-κB from cytoplasm to nucleus was observed by immunohistochemical analysis.①The cell death rate ,LDH release rate and TUNEL positivity in H 2O 2 exposure group after 3 h injury were significantly higher than those in the control group (P<0.01); ②H 2O 2 injury for 24h caused massive apoptosis of cardiomyocytes ; ③I-κB-levels began to decline 5 min after H 2O 2 treatment, reached its lowest figure at 15min, and then recovered gradually at 1h ; ④Translocation of NF-κB from cytoplasm to nucleus in cardiomyocytes was found after exposure to H 2O 2 for 0.5 h, and its relocation to cytoplasm happened 2h. later;⑤Compared with simple injury group, pyrrolidine dithiocarbamate (PDTC) ,an inhibitor of NF-κB, could obviously attenuate H 2O 2-induced LDH release rate in cardiomyocyte (P<0.01).[Conclusion]H 2O 2 could induce both necrosis and apoptosis in cultured neonatal rat cardiomyocytes, which may be mediated by activation of NF-κB/I-κB signal pathway.

关 键 词：心肌 过氧化氢 NF-ΚB 

分 类 号：R363[医药卫生—病理学]