Project description:MicroRNAs (miRNAs) are non-coding small RNA molecules that can be secreted into the circulation and which exist in remarkably stable forms. Circulating miRNAs regulates numerous regulations of biological process and aberrantly expressed in pathological status. Differentially expressed circulating miRNAs have received attention as potential biomarkers for many diseases. In this study, we revealed that miR-515-5p was significantly upregulated in maternal serum from preeclampsia (PE) patients in comparison to normal pregnant women. Bioinformatics prediction and a dual-luciferase reporter gene assay revealed that miR-515-5p directly targets the X-linked inhibitor of apoptosis protein (XIAP) 3’-untranslated region (UTR). Furthermore, the XIAP mRNA expression was decreased in the preeclamptic placenta in comparison to that in normal pregnancy. The overexpression of miR-515-5p inhibited the proliferation and invasion of HTR-8/SVneo trophoblast cells. Collectively, miR-515-5p may play critical roles in the pathogenesis of PE through suppression of the expression of XIAP and serum miR-515-5p may act as a potential biomarker for PE