肿瘤坏死因子α介导肝细胞凋亡其相关死亡区蛋白及mRNA的表达

mRNA and protein expression of Fas associated death domain protein in apoptosic hepatocyte induced by tumor necrosis factor α

目的 研究凋亡调节基因 Ｆａｓ相关死亡区蛋白（ＦＡＤＤ） ｍＲＮＡ及蛋白在肿瘤坏死因子α（ＴＮＦ α）介导的凋亡肝细胞中的表达及意义。方法 尾静脉注射ＴＮＦα于Ｄ－氨基半乳糖（ＧａｌＮ）致敏的ＢＡＬＢ／ｃ／小鼠，造成暴发性肝衰竭模型，用脱氧核糖核酸转移酶介导的缺口原位末端标记技术、电镜及琼脂糖凝胶电泳检测肝组织ＤＮＡ Ｌａｄｄｅｒ观察肝细胞凋亡，分别用免疫组织化学和ＲＴ－ＰＣＲ方法检测ＦＡＤＤ ｍＲＮＡ和蛋白的表达情况。结果ＴＮＦ α可介导ＧａｌＮ致敏小鼠肝细胞凋亡、坏死，最终肝功能衰竭死亡，细胞凋亡率分别为 ０（１．５ｈ）， ０．３％（３．５ｈ），３．１５％（６ｈ）和３．１９％（９ｈ），肝组织中ＦＡＤＤ蛋白表达阳性率分别为０、２％（１．５ｈ），３．３％（３．５ ｈ），１４．２％（６ｈ）和１６．７％（９ｈ），各时间点ＦＡＤＤ ｍＲＮＡ表达的相对单位（ＦＡＤＤ积分值／β－ａｃｔｉｎ积分值）不同，分别为０．４８（正常对照组）、０．６４（３．５ ｈ），０．５９（６ｈ）和０．６５（９ｈ）。结论 ＴＮＦα可通过上调ＦＡＤＤ表达引发肝细胞凋亡的级联过程。

Objective To study the expression of protein and mRNA of Fas associated death domain protein (FADD) in the apoptosic hepatocyte induced by D-galactosamine (GalN) and TNF α. Methods Fulminant hepatic failure (FHF) was induced by injection of GaiN into sensitized BALB/c mice by TNF α. Hepatocyte apoptosis was examined by electric microscopy, in site end labeling (ISEL) and DNA electrophoresis on 1.5% agarose gel. The expression of protein and mRNA of FADD were detected by immunohistochemistry and PT-PCR. Results GalN/TNF α may induce hepatocyte apoptosis, necrosis and liver failure. The expression of protein and mRNA of FADD were positively correlative with the apoptosic hepatocytes. Conclusions TNF α induces hepatocyte apoptosis by up regulation the expression of FADD protein.