氢化可的松对小鼠胚胎肠上皮凋亡的影响

The effect of hydrocortisone on epithelial apoptosis in fetal mice intestine

目的观察氢化可的松(hydrocortisone,HC)对胎鼠肠上皮细胞凋亡及凋亡相关蛋白表达的影响。方法分别取E13.5d、E14.5d胎鼠的十二指肠及结肠段,体外组织培养,实验各组分别加入HC液(0μg/ml,0.5μg/ml,1.0μg/ml,2.0μg/ml),培养24h后取出标本,制成石蜡切片。部分切片经HE染色,体视学法观测胎鼠肠上皮中的凋亡小体数;余切片经免疫组化染色,观察凋亡相关蛋白Bcl-2,Bax,P53及c-Fos的表达。结果①各实验组胎鼠肠上皮凋亡小体数均较对照组高,P<0.05,与HC剂量呈正相关,P<0.01。②各实验组胎鼠肠上皮细胞表达的Bcl-2均较对照组低,P<0.05,与HC的剂量呈负相关,P<0.01;而Bax及c-Fos的表达则高于对照组,P<0.05,与HC剂量均呈正相关,P<0.01;P53的表达差异无统计学意义。结论HC在体外可促进胎鼠肠上皮细胞凋亡,可能是一种通过下调Bcl-2表达,上调Bax及c-Fos表达的P53非依赖机制。

Objective:To study the effect of hydrocortisone (HC) on apoptosis and expression of apoptosis- associated proteins in the intestinal epithelium of fetal mice.Methods:The duodena and colons were taken from E13.5d and E14.5d fetal mice respectively,and cultured with different doses of HC (0 μg/ml,0.5μg/ml,1.0μg/ml,2.0μg/ml).After 24h,the samples were sliced up into the paraffin sections.Some sections were stained with HE to count the numbers of apoptotic bodies (NAB)in the fetal intestinal epithelium with stereological method.Others were stained with the immunohistochemical method to observe the expression of Bcl-2,Bax,P53 and c-Fos.Results:①In each experimental group,the NAB were higher than that of control group( P <0.05),and there was a positive correlation between the doses of HC and the NAB( P <0.01).②In all experimental group,the expression of Bcl-2 in the intestinal epithelium of fetus was lower than that of control group( P <0.05),and there was a negative correlation between the doses of HC and the expression of Bcl-2( P <0.01).But the expression of Bax and c-Fos in experimental group was higher than that of control group( P <0.05),and there was a positive correlation between the doses of HC and the expression of these proteins( P <0.01).The significant change in expression of P53 was not observed.Conclusion:HC can increase the intestinal epithelium-apoptosis of fetal mice in vitro.The effect may be a P53-independent mechanism completeed through restraining the expression of Bcl-2 and promoting the expression of Bax and c-Fos.