Distinct DNA methylomes of human placentas between pre-eclampsia and gestational diabetes mellitus

The placenta acts not only as a conduit of nutrient and waste exchange between mother and developing fetus but also functions as a regulator of the intrauterine environment. Pre-eclampsia (PE) and gestational diabetes mellitus (GDM) are leading causes of complications during pregnancy. Pathophysiologies show that they are associated with one another. Epigenetics provides a link between environmental factors that have previously been linked to poor pregnancy outcomes and fetal programming.

The present study investigated genome-wide DNA methylation changes in PE and GDM compared with control subjects through DNA methylation microarray. We found that the methylation patterns of placentas from PE and GDM women were similar; 64.4% of the annotated genes with differential methylation presented concordant changes between PE and GDM patients. Significantly, the same functional processes were affected by PE and GDM, with cell adhesion and cell differentiation being the most populated clusters and including genes related to carbohydrate metabolism and lipid metabolism.

Our work showed that of DNA methylation patterns in human placentas are reliably and significantly associated with PE and GDM. DNA methylation status in the human placenta can function as a marker for the intrauterine environment and potentially play a functional role in PE and GDM development.