Expression of S100A10 gene and its regulation by sex hormones in mouse uterus

Abstract

Abstract S100A10 belongs to the S100 calcium binding protein superfamily, and functions as one of the mediators of calcium-de-pendent signaling pathway. Recently, S100A10 gene was proved to be significantly up-regulated at the implantation site. In the present study, semi-quantitative reverse transcriptase-polymerase chain reaction and in situ hybridization are used to investigate the tissue-specificity of S100A10 expression and the expression pattern of S100A10 in the uteri during the estrous cycle and pregnancy. Meanwhile, the regulation of S100A10 expression by sex steriod hormones is studied in ovariectomized mice. The results show that S100A10 could be detected in various kinds of tissues, with relatively high expression in reproductive tracts induding ovary, uterus, testis and epididymis. During pregnancy, the expression of S100A10 in the uteri is significantly up-reulated on the 4th day. The transcript is strongly detectd in endometrial stromal cells and weakly in luminal epithelium cells at the implantation site, but almost not at the inter-implantation site. From gestational day 5 till labor, S100A10 mRNA maintains a certain level in both uteri and placentae. During the estrous cycle, expression of S100A10 is up-regulated in the uteri at proestrus and estrus. Estrediol significantly induces the expression of S100A10, while progesterone can abolish the effect of estradiol. The data suggests that S100A10 may be involved in preventing luminal epithelial cells from over-apoptosis, inducing proliferation and decidualization of stromal cells during implantation, and responding to reprductive stress triggered by copulation.