脓毒症小鼠肠道上皮细胞凋亡与白细胞介素1β转换酶基因表达的关系

Correlation of interleukin 1β converting enzyme(ICE) gene expression with gut epithelial cell apoptosis in septic mice

目的研究脓毒症后小鼠肠道上皮细胞凋亡与ＩＬ－１β转换酶（ＩＣＥ）及细胞因子ＩＬ－１β基因表达的关系。方法盲肠结扎穿孔（ＣＬＰ）造成小鼠脓毒症，假手术组接受同样的手术操作但不行ＣＬＰ。致伤后１、３及６小时分离肠上皮细胞，采用ＲＴ－ＰＣＲ定量检测ＩＣＥ基因的表达，琼脂糖凝胶电泳和流式细胞仪定量检测肠上皮细胞凋亡。结果ＣＬＰ组小鼠肠上皮细胞内ＩＣＥ和ＩＬ－１β的表达明显高于假手术组（Ｐ＜０．０１），肠上皮细胞内ＩＬ－１β基因表达与ＩＣＥ基因表达存在明确的依赖性且明显高于假手术组（Ｐ＜０．０１），以致伤后６小时表达量最高。肠上皮细胞凋亡在ＣＬＰ后１小时开始出现并在６小时最明显，细胞凋亡与ＩＣＥ和ＩＬ－１β基因表达成正比。假手术组未检测到肠上皮细胞凋亡。

Objective To investigate the correlation of gut epithelial cell apoptosis with ICE,IL1β gene expression in septic mice. Methods Sepsis was induced in mice by cecal ligation and puncture(CLP). Sham operation group underwent the same manipulation but without CLP. 1,3,6 hours after CLP, gut epithelial cells. were isolated. IL1β, ICE gene expression was detected quantitatively by RT PCR. Epithelial cell apoptosis was assessed by flow cytometric method and biochemically by DNA electrophoresis. Results the survival rate of CLP mice was 1/10 as compared to 10/10 of sham operation mice. IL1β, ICE mRNA expression in CLP mice was significantly higher than that in the sham operation group( P <0 01); IL1β mRNA expression was parallel to ICE mRNA expression. The number of epithelial cell apoptosis was correlated excellently to the level of ICE, IL1β mRNA expression. Epithelial cell apoptosis could not be detected in sham operation group at the indicated time points. Conclusion ICE,IL1β gene overexpression may be involved in the vulnerability of epithelial cell apoptosis in septic mice.