Ovary Hormonal Control of Le(y) Oligosaccharide Expression during Peri-implantation of Mouse Endometrium

It has been reported that oligosaccharide Le(y) plays an essential role at the initial stage of implantation. It may act as a mediator molecule for recognition and adhesion between the surface of blastocysts and epithelial cells. Alpha 1,2 fucosyltransferase (FUT1) and alpha1,3 fucosyltransferase (FUT4) are responsible for the synthesis of its alpha1,2 and alpha1,3 fucose, respectively. In this article, the transcription of FUT1 and FUT4 genes was investigated by semi-quantitative RT-PCR and the expression of Le(y) oligosaccharide was analysized by Western blotting and immunohistochemistry with the endometrium of early pregnancymice and of the mice treated by ovary hormones after ovariectomy, in order to investigate the regulation of ovary hormones on the Le(y) oligosaccharide antigen expression. The results showed that the transcription level of FUT1 and FUT4 genes decreased during early pregnancy through days 1--5, which was in agreement with the increasing level of progesterone. In the ovariectomized group, the transcription level of the genes decreased significantly after progesterone treatment and increased after estrogen treatment, and was at the intermediate level in the group treated with both hormones. The biosynthesis of Le( y ) oligosaccharide paralleled with the transcription of FUT 1 and FUT4 gene. These results suggest that the expression of Le(y) oligosaccharide in the endometrial epithelium of mice is regulated at the level of transcription of FUT1 and FUT4 genes. It is suppressed by progesterone and stimulated by estrogen, and the effects of both hormones are in antagonism.