NF-κB在热休克预处理减轻TNF-α所致内皮细胞凋亡中的作用  

Role of NF-κB in protection of heat shock pretreatment against TNF-α-induced endothelial cell apoptosis

作　　者：钟林[1] 尢家騄[1] 肖献忠[1] 孙去病[1] 

机构地区：[1]湖南医科大学病理生理学教研室

出　　处：《中国病理生理杂志》1999年第5期436-440,共5页Chinese Journal of Pathophysiology

摘　　要：目的：探讨核转录因子－κＢ（ＮＦ－κＢ）在热休克预处理减轻肿瘤坏死因子－α（ＴＮＦ－α）所致内皮细胞凋亡中的作用。方法：将培养牛肺动脉内皮细胞（ＢＰＡＥＣ）于４２℃孵育１ｈ，３７℃再培养１６ｈ后，用ＴＮＦ－α（２５００Ｕ／ｍＬ）损伤２４ｈ，观察ＢＰＡＥＣ形态学变化、ＤＮＡ断裂百分率，抽提ＤＮＡ作琼脂糖电泳，以确定细胞凋亡情况。Ｗｅｓｔｅｒｎｂｌｏｔ分析７０ＫＤ－热休克蛋白（ＨＳＰ７０）合成、ＮＦ－κＢ抑制蛋白Ｉ－κＢα量的改变以及诱导型一氧化氮合酶（ｉＮＯＳ）的生成。凝胶滞留法检测ＮＦｋＢ活性，免疫组织化学染色法分析ＮＦｋＢ的移位。结果：热休克预处理可明显减轻ＴＮＦ－α所致ＢＰＡＥＣ凋亡，表现为与ＴＮＦ－α损伤组相比，凋亡细胞减少，ＤＮＡ电泳未出现明显“梯状”条带，ＤＮＡ断裂百分率降低。进一步实验发现热休克预处理可诱导ＢＰＡＥＣ合成ＨＳＰ７０，并可抑制ＴＮＦ－α引起的ＢＰＡＥＣ的Ｉ－κＢα的降解、ＮＦ－κＢ向细胞核的移位、ＮＦ－κＢ与ＤＮＡ的结合活性，以及ｉＮＯＳ的生成。结论：热休克预处理可减轻ＴＮＦ－α所致ＢＰＡＥＣ凋亡，其机制与ＨＳＰ７０阻断Ｉ－κＢα降解，从而抑制ＮＦ－κＢ活化，抑制ｉＮＯＳ转隶合成有?AIM:To explore the role of nuclear factor kappa B (NF-κB) in protection of heat shock pretreatment against TNF-α induced endothelial cell apoptosis.METHODS: Cultured bovine pulmonary artery endothelial cells (BPAECs) were exposed to TNF-α(2 500 U/mL, 24 h) 16h after heat shock pretreatment(43℃,1h). The apoptotic morphological changes, DNA ladder pattern on agarose gel electrophoresis, and percentage of DNA fragmentation of BPAEC were analyzed. Inducible heat shock protein-70 kD(HSP70), inhibitor κBα(I-κBα) levels, expression of inducible nitric oxide synthase(iNOS) and NF-κB activity, NF-κB translocation to nuclei were detected using Western blot analysis, electrophoretic mobility shift assays (EMSA), and immunohistochemical analysis respectively.RESULTS:Heat shock pretreatment significantly attenuated TNF-α induced apoptosis in BPAEC. To compared with TNF-α treated BPAEC, heat shocked cells showed less apoptotic cells, no specific DNA ladder pattern agarose gel electrophoresis, and less increase of percentage of DNA fragmentation. Further, it was found that heat shock pretreatment induced expression of HSP70, and inhibited TNF-αmediated I-κBα degradation, NF-κB translocation, NF-κB binding activity, and iNOS expression.CONCLUSION: Heat shock pretreatment could protect BPAEC against TNF-α induced apoptosis, and its mechanism might involve HSP70 inhibition of TNF-α mediated NF-κB activity and iNOS expression.

关 键 词：心肌损伤 NF-KB 热休克蛋白 TNFΑ 

分 类 号：R542.202[医药卫生—心血管疾病]