Differentially expressed microRNAs revealed by molecular signatures of Preeclampsia and IUGR in human placenta

The placenta plays an important role as a regulator of fetal nutrition and growth throughout development and placental factors contribute to gestational abnormalities such as preeclampsia. This study describes the genome-wide gene expression profiles of a large (n=94) set of human placentas in order to uncover gene expression patterns (or molecular signatures) associated with preeclampsia and IUGR. Besides modulated modularity clustering and pathway analysis, a set of candidate miRNAs were predicted by Gene Set Enrichment Analysis (GSEA) based on differentially expressed genes. A case-control study was conducted to examine the expression patterns of these candidate miRNAs in human placentas 35 IUGR (including 8 technical repeats for batch effect), 19 preeclamptic and 40 control placentas included in this study were collected during the years of 2004-2008 and hybridized in two batches to microarrays. Samples were randomized across arrays to control for array and batch variability.