小鼠胚胎食管和肠上皮细胞增殖与凋亡

Proliferation and apoptosis of epithelia in esophagus and intestines of fetal mice

目的:研究小鼠胚胎食管和肠上皮细胞的增殖与凋亡。方法:体视学方法观测E1117dICR胎鼠食管、十二指肠和结肠上皮的增殖与凋亡,免疫组化法显示Bcl2、P53、Bax在三段消化管上皮中的表达。结果:三段消化管的上皮细胞密度与凋亡小体密度和分裂细胞密度间未见一致的相关性。凋亡小体分布食管上皮各层,而肠上皮中主要在游离面。Bcl2和p53在食管、小肠、结肠上皮细胞中表达峰值分别在E11d～13d和E11d～14d,Bax的表达峰值分别为E11d、E14d、E15d。结论:上皮细胞密度对上皮细胞分裂和凋亡的影响不明显。食管和肠上皮中凋亡小体分布的不同可能与形态发生方式不同有关。Bax和Bcl2可能分别具有促进和抑制肠上皮细胞凋亡的作用;p53与上皮细胞凋亡的关系不密切。

Objective:To study the proliferation and apoptosis of epithelia in the esophagus and intestines of fetal mice. Methods: The epithelial proliferation and apoptosis of the esophagus, duodenum and colon of ICR fetal mice aged E1l-17 d were measured with the stereological method.The expression of Bcl-2,p53, Bax in the epithelium of the 3 segments of digestive tract were studied by immunohistochemical method.Results: In the 3 segments of digestive tract,the unanimous correlation had not been found among the density of epithelial cells (DEC), density of mitotic cells and density of apoptotic body. The apoptotic bodies distributed in all layers of the epithelial cells in the esophagus,but mainly located near the free surface of epithelium in the intestines. The peak value of Bcl-2 and p53 in the epithelium of the 3 segments of digestive tract were found on E11 d to E13 d, E11 d to E14 d respectively, the peak value of Bax were found on E11 d, E14 d, E15 d respectively. Conclusion:The influence of DEC on the epithelial proliferation and apoptosis in the fetal digestive tract is not obvious. The different location of apoptotic bodies between esophagus and intestines may be correlated with their different patterns of morphogenesis. Bax may play a role in promoting epithelial apoptosis of intestines in fetus mice; Bcl-2 may have an adverse role. p53 is not closely correlated with the epithelial apoptosis of digestive tract in fetus mice.