Expression of KCNH2 (hERG1) and KCNE2 correlates with expression of key myometrial genes in term pregnant human myometrium

Background: Loss of activity of Kv11.1 potassium channels (encoded by KCNH2) facilitates labor, and is associated with expression of an inhibitory subunit encoded by KCNE2. Objective: To determine whether KCNH2 and KCNE2 expression was linked to expression of key genes involved in myometrial contractility, including the oxytocin receptor (OXTR), estrogen receptor 1 (ESR1), progesterone receptor (PGR) and Prostaglandin-Endoperoxidase Synthase 2 (PTGS2). We further aimed to examine KCNH2 and KCNE2 expression in preterm samples. Study Design: Biopsies of term or preterm, non-laboring human myometrium were analysed by qPCR to determine KCNH2 and KCNE2 mRNA abundance, as well as abundance of OXTR, ESR1, PGR and PTGS2 mRNAs. Results: KCNH2 and KCNE2 expression were significantly correlated at term, but not correlated with BMI. KCNH2 expression significantly correlated with OXTR, ESR1, PGR and PTGS2 expression, while KCNE2 expression correlated with the expression of ESR1, PGR and PTGS2. Preterm samples revealed no difference in KCNH2 and KCNE2 expression compared to term. Conclusion: KCNH2 and KCNE2 expression correlate with the expression of key myometrial genes implicated in parturition, further strengthening a role for Kv11.1 channels in human pregnancy. Neither gene was correlated with BMI, suggesting that previously reported effects of obesity likely affect protein levels rather than gene expression.