Placental microarray profiling reveals common mRNA and lncRNA expression patterns in Preeclampsia and Intrauterine Growth Restriction

Preeclampsia (PE) and Intrauterine Growth Restriction (IUGR) are major contributor of perinatal morbility and mortality, these pregnancy disorders associated with placental ischemia and share many similar pathophysiological features. The aim of this study was to compare the placental gene expression profiles including mRNA and lnRNAs from pregnant women from four study groups; PE, IUGR, PE-IUGR and normal pregnancy (NP). Gene expression microarray analysis was performed on placental tissue obtained at the moment of delivery and results were validated using RTq-PCR. Differential gene expression analysis revealed that the largest transcript variation was observed in the IUGR samples compared to NP (n=461; 314 mRNAs: 252 up-regulated and 62 down-regulated) and 133 lncRNAs: 36 up-regulated and 98 down-regulated). We also detected a group of differentially expressed transcripts shared between the PE and IUGR samples compared to NP (n=39), including 9 lncRNAs with a high correlation degree (P <0.05). Functional enrichment of these shared transcripts showed that cytokine signaling pathways, protein modification and regulation of JAK-STAT cascade are over-represented in both placental ischemic diseases. These findings contribute to the molecular characterization of placental ischemia showing common epigenetic regulation implicated in the pathophysiology of preeclampsia and Intrauterine Growth Restriction Gene expression profiles from placental samples obtained at the moment of delivery from four study groups were determined usign Agilent SurePrint G3 Human Gene Expression v3 8x60K Microarrays (G4851C, Agilent Technologies). Group distribution consisted in: Intrauterin Growth restriction (n=7), Preeclampsia (n=7), Preeclampsia and Intrauterine Growth Restriction (n=6) and Normal Pregnancy (n=8). Diagnosis was stablished according to the ACOG, 2013 criteria. All samples were obtained from pregnant women with intact membranes, no clinical evidence of intrauterine infection, with singleton pregnancy and who delivered by cesarean section (C-section) with no evidence of active labor. RNA was extracted righ after colletion of fresh rinsed and washed fullthickness placental tissue using RNeasy Fibrous Tissue Mini Kit (Quiagen). All RNA samples were evaluated for RIN and showed values ≧7.