miR-143 regulation of prostaglandin-endoperoxidase synthase 2 in the amnion: implications for human parturition at term.

The human amnion plays a pivotal role in parturition. Two of its compartments, the placental amnion and the reflected amnion, have distinct transcriptome and are functionally coordinated for parturition. This study was conducted to determine the microRNA (miRNA) expression pattern and its significance in the placental amnion and the reflected amnion in association with labor at term.MicroRNA microarray, real-time quantitative RT-PCR (qRT-PCR), and miRNA in situ hybridization analyses of the placental amnion and the reflected amnion (n = 20) obtained at term were conducted. Luciferase assay, transfection, and qRT-PCR analyses of primary amnion epithelial cells (AECs) and amnion mesenchymal cells (AMCs) were performed. MicroRNA microarray analysis demonstrated differential expression of 32 miRNAs between the placental amnion and the reflected amnion after labor. Thirty-one (97%) miRNAs, which included miR-143 and miR-145, a cardiovascular-specific miRNA cluster, were down-regulated in the reflected amnion. Analyses of miR-143 and miR-145 by qRT-PCR confirmed microarray results, and further demonstrated their decreased expression in the reflected amnion with labor. Interestingly, expression of miR-143 and miR-145 was higher in AMCs than in AECs (p