MicroRNAs derived from urinary exosomes act as novel biomarkers in the diagnosis of intrahepatic cholestasis of pregnancy.

We aimed to investigate the value of cholestasis-related miRNAs in the diagnosis of intra-hepatic cholestasis of pregnancy (ICP) as well as the molecular mechanisms underlying the role of these miRNAs in the pathogenesis of ICP. In this study, electron microscopy was utilized to observe the exosomes present in the urine samples collected from both ICP patients and healthy pregnant women. Real-time PCR and area under curve (AUC) analysis were performed to predict the values of several miRNAs in the diagnosis of ICP. Bioinformatics analysis and luciferase assays were conducted to identify the target genes of miR-21, miR-29a and miR-590-3p, whose regulatory relationships were then established using real-time PCR, immunohistochemistry (IHC) assay and Western Blot. In the exosomes isolated from urine samples, several miRNAs, including miR-21, miR-29a and miR-590-3p, were differentially expressed between ICP patients and healthy pregnant women. In addition, the gene of intercellular adhesion molecule 1 (ICAM1) was identified as a shared target of miR-21, miR-29a and miR-590-3p, all of which inhibited ICAM1 expression. Therefore, up-regulated expression of miR-21, miR-29a and miR-590-3p in urinary exosomes reduced the expression of ICAM1, which in turn increased the incidence of ICP.