肿瘤坏死因子α致暴发性肝功能衰竭小鼠肠上皮细胞凋亡的作用  

Tumor necrosis factor alpha and enterocyte apoptosis in mice with fulminant hepatic failure

作　　者：宋红丽[1] 吕飒[1] 刘沛[1] 

机构地区：[1]中国医科大学附属第二医院感染科,沈阳110004

出　　处：《中华肝脏病杂志》2005年第4期290-293,共4页Chinese Journal of Hepatology

基　　金：卫生部临床重点项目(97100252)

摘　　要：目的研究肿瘤坏死因子α(TNFα)对暴发性肝功能衰竭(FHF)小鼠肠黏膜上皮细胞凋亡的作用。方法用D-氨基半乳糖(GalN)+脂多糖(LPS)或TNFα造FHF小鼠模型;酶联免疫吸附法测定血清TNFα含量;光学显微镜和电子显微镜观察肠组织;末端转移酶介导的dUTP缺口末端标记法检测肠组织细胞凋亡情况;免疫组织化学法检测肿瘤坏死因子受体I(TNFRⅠ)蛋白在肠组织的表达与分布。结果实验各组动物各时间点光学显微镜下肠黏膜上皮细胞结构均保持完整,电镜下可见肝功能衰竭组有典型的凋亡细胞;对照组、LPS组、GalN组血清TNFα水平几乎正常,凋亡率低且基本没有TNFRⅠ蛋白表达;GalN+LPS组血清TNFα水平12h明显升高(P<0.01),且TNFRⅠ蛋白在6h(大肠:2.82e+4±4.60e+3;小肠:1.14e+4±2.13e+3)即有表达,此时肠上皮细胞凋亡不明显,9h和12hTNFRⅠ蛋白表达明显增加,同时肠上皮细胞凋亡也明显。用GalN+TNFα造FHF模型,结果也与GalN+LPS组类似。应用抗TNFα抗体,可降低TNFRⅠ蛋白表达和减少肠上皮细胞凋亡的发生。结论TNFα能诱导肝功能衰竭小鼠肠上皮细胞凋亡,抗TNFα抗体能阻断这一作用;在FHF的模型动物中,TNFRⅠ蛋白表达增多,TNFRⅠ蛋白表达与肠上皮细胞凋亡在一定程度上呈正相关。Objective To study the role of tumor necrosis factor α (TNFα) on enterocyte apoptosis in the experimental model of fulminant hepatic failure (FHF). Methods Liver damage was induced by lipopolysaccharide (LPS)/TNFα in D-galactosamine (GalN) sensitized BALB/c mice. Serum TNFα levels were determined by enzyme-linked immunosorbent assays (ELISA). The intestinal tissues were studied micro- and ultra-microscopically at 2 h, 6 h, 9 h, 12 h and 24 h time points in mice with fulminant hepatic failure. Enterocyte apoptosis was determined by TUNEL method. The TNFR Ⅰ expression in the intestinal tissue was tested by immunohistochemistry. Results (1) Gut mucosa was morphologically normal at every time point in all groups, but typical apoptotic cells could be seen in the experimental groups under the electron microscope. Apoptosis rate of gut mucosal epithelial cells was significantly increased at 6 h (large intestine: 6.47e-3±2.91e-4; small intestine: 6.64e-3±3.78e-4), 9 h (large intestine:6.81e+4±7.41e+3; small intestine: 2.58e+4±2.28e+3) and 12 h (large intestine:4.92e+4±9.80e+3; small intestine: 5.24e+4±3.01e+3), and peaked at 12 h in mice with FHF. (2) TNFα induced apoptosis of enterocytes in mice with FHF. Anti-TNFα inhibited this effect. (3) The integrated OD (IOD) levels of TNFα receptor Ⅰ protein expressed differently in the intestine of mice with GalN/LPS and GalN/ TNFα -induced FHF at 9 h after GalN/LPS and GalN/TNFα administration, in comparison with those of the control groups. IOD level of TNFR Ⅰ changed significantly at 6 h (large intestine: 2.82e+4±4.60e+3; small intestine: 1.14e+4±2.13e+3), 9 h (large intestine: 6.81e+4±7.41e+3; small intestine: 2.58e+4±2.28e+3) and 12 (large intestine: 4.92e+4±9.80e+3; small intestine: 5.24e+4±3.01e+3) hours after GalN/LPS and GalN/ TNFα administration. The ex- pression of TNFR1 protein was significantly higher at 9 and 12 h after GalN/LPS and GalN/TNFα administration than other time points. Protein expression of TNFR1 was positively correlated wi

关 键 词：肿瘤坏死因子Α 暴发性肝功能衰竭 小鼠 肠上皮细胞 细胞凋亡 

分 类 号：R575.3[医药卫生—消化系统]