Effect of Hypoxia in Severe Preeclampsia through Epigenetic Regulation

Though the pathophysiology of preeclampsia (PE) is unclear worldwide, placental hypoxia has been implicated in the pathologic processes of PE.In this study, we profiled the transcriptome in BeWo and JEG-3 cells cultured in hypoxic condition or normal ones based on the RNA sequencing dataset. After filtered the low-quality ones, the RNA readers was aligned to human genome hg19 by TopHat and then assembled by Cufflinks. The expression value of each transcript was calculated and consequently differentially expressed genes were screened out. CD39 and ZDHHC14 were found to have both different mRNA in hypoxic cells and abnormal methylation level in severely preeclamptic placentas. The mRNA expression of CD39 and ZDHHC14 in placental tissues were analyzed using qRT-PCR. The differential methylated regions (DMRs) of CD39 and ZDHHC14 were confirmed by MassARRY EppiTYPER. The effect of hypoxia on trophoblast cells was detected with western blotting and enzyme linked immunosorbent assay. The results showed CD39 and ZDHHC14were significantly lower in severe PE placenta, hypoxia significantly reduced the expression of CD39 and ZDHHC14 and the secretion of CD39 in trophoblast cells. Therefore, we believed hypoxia plays an important role in the processes of severe PE via decreasing the expression of CD39 and ZDHHC14 by changing their methylation level in placenta. Overall design: mRNA profiles of three cell lines at five stages and two different conditions were generated by deep sequencing, using HiSeq 2500.