Hypoxia-inducible factor 1 signaling drives placental aging and can elicit inflammatory changes in uterine myocytes

Placental aging has been proposed to promote labor onset, but specific mechanisms remain elusive. An unbiased transcriptomic analysis of healthy mouse placenta revealed that hypoxia-inducible factor 1 (HIF-1) stabilization is a hallmark of advanced gestational timepoints, accompanied by mitochondrial dysfunction and cellular senescence. We validated these gestational age-associated changes through similar findings in human placenta. In parallel in primary mouse trophoblasts and human choriocarcinoma JAR cells, we modeled HIF-1 induction using prolyl hydroxylase inhibitors cobalt chloride (CoCl2) and dimethyloxalylglycine (DMOG), and demonstrated that mitochondrial dysfunction and cellular senescence occur secondary to HIF-1 stabilization. Whole transcriptome analysis revealed that HIF-1 stabilization in JAR cells recapitulated the dysregulation of several pathways observed in aged placenta. Further, conditioned media from cultured trophoblasts following HIF-1 induction is sufficient to induce a contractile phenotype in immortalized uterine myocytes, suggesting a mechanism by which the aging placenta may help drive the transition from uterine quiescence to contractility at the onset of labor. Overall design: RNA was isolated from JAR choriocarcinoma cells following six days of culture with 100µM CoCl2 versus control conditions (six replicates each) for expression profiling by high-throughput sequencing