GSE105444
H3K27me3 dynamics dictate evolving uterine states in pregnancy and parturition [ChIP-seq]
Uncovering the causes of pregnancy complications such as preterm labor requires greater insight into how the uterus remains in a non-contractile state until term and then surmounts this state to enter labor. Here, we show in mice that dynamic deposition and removal of repressive H3K27me3 chromatin marks in decidual stromal cells dictate both elements of pregnancy success. In early gestation, H3K27me3-induced transcriptional silencing of select gene targets insures uterine quiescence by preventing the decidua from expressing parturition-inducing hormone receptors, manifesting type 1 immunity, and, most unexpectedly, generating myofibroblasts and associated wound healing responses. In late gestation, genome-wide H3K27 demethylation allows for target gene upregulation, decidual activation, and labor entry. Strikingly, pharmacological inhibition of this latter process not only prevented term parturition, but also inhibited delivery while maintaining pup viability in a non-inflammatory model of preterm parturition. Immunofluorescence analysis of human specimens suggested that similar regulatory events might occur in the human decidua. Together, these results reveal the centrality of regulated gene silencing in the uterine adaptation to pregnancy and suggest new areas in the study and treatment of pregnancy disorders. Overall design: H3K27me3 ChIP-Seq was performed on purified uterine stromal cells or whole uterine tissue layers. Biological replicates (1-3) are indicated. Each H3K27me3 ChIP has its own associated input chromatin control.