Reproductive sciences
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Reproductive sciences · Feb 2018
Control of Progesterone Receptor-A Transrepressive Activity in Myometrial Cells: Implications for the Control of Human Parturition.
Uterine quiescence during pregnancy is maintained by progesterone primarily via signaling mediated by the type-B progesterone receptor (PR-B) in myometrial cells. Withdrawal of PR-B-mediated progesterone activity is a principal trigger for labor. One mechanism for PR-B withdrawal is by inhibition of its activity by the type-A PR (PR-A) isoform in myometrial cells. ⋯ In pregnant uterus, FKBP5 was detected exclusively in myometrial cells and its expression decreased with advancing gestation and in association with the onset of labor at term. These findings suggest that in myometrial cells the repressive activity of PR-A on PR-B increases with advancing gestation and is induced by pro-inflammatory cytokines. This may be a key mechanism linking inflammation with the onset of labor.