Polyamines are essential in embryo implantation: Expression and function of polyamine-related genes in mouse uterus during peri-implantation period

Polyamines are key regulators in cell growth and differentiation. It has been shown that ornithine decarboxylase (Odc) was essential for post-implantation embryo development, and overexpression of spermidine/spermine N1-acetyltransferase will lead to ovarian hypofunction and hypoplastic uteri. However, the expression and function of polyamine-related genes in mouse uterus during early pregnancy are still unknown. In this study we investigated the expression, regulation, and function of polyamine-related genes in mouse uterus during the peri-implantation period. Odc expression was strongly detected at implantation sites and stimulated by estrogen treatment. The expression of Odc antizyme 1 and spermidine/spermine N1-acetyltransferase was also highly shown at implantation sites and regulated by Odc or polyamine level in uterine cells. Embryo implantation was significantly inhibited by alpha-difluoromethylornithine, an Odc inhibitor. Moreover, the reduction of Odc activity caused by alpha-difluoromethylornithine treatment was compensated by the up-regulation of S-adenosylmethionine decarboxylase gene expression. Collectively, our results indicated that the coordinated expression of uterine polyamine-related genes may be important for embryo implantation.