IL-1β represses progesterone action via NFκB.

<p><b>A,</b> Myometrial cells were transiently co-transfected with a progesterone response element (PRE), with or without progesterone receptor B (PRB) and p65. SG5 was used as control. MPA and IL-1β were added 24 h after transfection and the cells were incubated for another 24 h before luciferase assay. <b>B,</b> Myometrial cells were transfected with either siRNA for p65 (sip65) or a non-targeting siRNA (siNT) as control. After 72 h, cells were co-transfected with PRB and PRE. MPA and IL-1β were added at day 4 post-transfection and cells were then incubated for another 24 h before luciferase assay. <b>C,</b> Myometrial cells were exposed to different stimuli, IL-1β, MPA and progesterone, either alone or in combination. mRNA was then extracted, and the FKBP5 mRNA levels were measured using qPCR. Data are expressed as median, 25^th and 75^th percentiles and range, and were analysed using Wilcoxon matched pairs test. *indicates a significant difference of <i>p</i><0.05, **, of <i>P</i><0.01, and ***, of <i>P</i><0.001; NS indicates no statistic significant difference (n = 6–12).