Pro-apoptotic signals of the bcl-2 gene family in the rat uterus occurs in the night before the day of estrus and precedes ovulation

[摘要] Although regression of the endometrium during the rat estrous cycle is a well-recognized event, little is known concerning the mechanisms involved in triggering apoptosis in the rat uterine epithelium. In an attempt to have a better understanding of the mechanisms underlying apoptosis during estrus, we evaluated the expression of several key apoptotic genes of the bcl-2 family during the transition from proestrus to estrus day in the rat. Our results show significant changes in the expression of bcl-2 family genes at midnight before estrus, characterized by a significant increase in the pro-apoptotic ratios: Bax/Bcl-2 and Bcl-x(S)/Bcl-x(L) at both mRNA and protein levels. Our results indicate the existence of a positive relation between apoptosis and pro-apoptotic ratios of bcl-2 gene family expression, during the transition from proestrus to estrus day. Importantly, pro-apoptotic signals were detected before ovulation occurred. The overall results suggest that the apoptotic process of the rat endometrium begins at midnight before the day of estrus, may be mediated by Bcl-2 family genes, and precedes ovulation. (C) 2003 Elsevier Ireland Ltd. All rights reserved.

[发布日期] 2003-10-31

[关键词] apoptosis (rat endometrium);bcl-2 gene family;estrous cycle