Possible involvement of p38 mitogen-activated protein kinase in decidual function in parturition

We designed the present study to elucidate the molecular mechanism for part urition, focusing on p38 mitogen-activated protein kinase (p38). The kinase activity of p38 in mouse uterus was gestation stage-dependent, and was mar kedly increased on day 19 of gestation and during labor. Immunohistochemica l examination with anti-phospho p38 antibody revealed that activated p38 wa s predominantly localized in decidual stromal cells stained with anti-prola ctin antibody. In human primary cultured decidual cells, a p38 inhibitor, S B202190, significantly inhibited both prostaglandin F-2 alpha production an d COX-2 expression induced by stimulation with IL-1 beta. These results sug gest that the p38 signaling pathway is involved in decidual function at the late stage of gestation and may contribute to parturition. (C) 2001 Academ ic Press.