Inhibition of cAMP-mediated decidualization in human endometrial stromal cells by IL-1 beta and laminin

Both IL-1 and laminin are reported to inhibit progesterone receptor-mediate d decidualization signals in endometrial stromal cells, but the effects of these two inhibitors on cAMP-mediated decidualization signals remain unknow n. Furthermore, the interaction between IL-1-stimulated and laminin-stimula ted signals has not been analyzed yet. In this study, interactions between these two decidualization-inhibitory signals and their effects on 8-Br-cAMP -mediated decidualization in human endometrial stromal cells were investiga ted. Prolactin release from decidualized stromal cells was measured by enzy me immunoassay in order to quantitate in vitro decidualization. Both IL-1 b eta and laminin were found to inhibit 8-Br-cAMP-induced decidualization in vitro in human endometrial stromal cells. IL-1 beta dose-dependently inhibi ted decidualization of stromal cells cultured on both laminin-coated and co llagen-coated dishes, while laminin inhibited the decidualization of stroma l cells cultured both with and without IL-1 beta. These results indicate th at IL-1 beta and laminin additively and mutually inhibit cAMP-mediated deci dualization signals, and that they may inhibit these signals through differ ent mechanisms.