Plasma-derived exosomal miRNA profiles reveal potential epigenetic pathogenesis of premature ovarian failure.

The role of plasma-derived exosomal miRNA in premature ovarian failure (POF) remains unclear. This study aimed to investigate the epigenetic pathogenesis of POF through exosomal miRNA sequencing. Exosomes were isolated and characterized from six POF patients and four healthy individuals using nanoparticle tracking analysis, transmission electron microscopy and western blot analysis. Exosomal miRNA sequencing was performed to identify differentially expressed miRNAs with |fold change| greater than 1.5 and p value less than 0.05. Bioinformatics analysis in GSE39501 dataset and our sequencing data was conducted to investigate underlying mechanisms of POF. The functional role of hsa-miR-19b-3p was assessed using CCK8, western blot, flow cytometry and fluorescence staining. The regulatory effect of hsa-miR-19b-3p on BMPR2 was investigated through miRNA transfection, qPCR analysis, and luciferase reporter assay. Statistical significance was determined using t-tests and one-way ANOVA (p < 0.05). Exosomal miRNA sequencing revealed 18 dysregulated miRNAs in POF patients compared to healthy controls. Functional enrichment analysis demonstrated their involvement in cell growth, oocyte meiosis and PI3K-Akt signaling pathways. Moreover, the constructed miRNA-mRNA network unveiled potential regulatory mechanisms underlying POF, particularly implicating hsa-miR-19b-3p in the regulation of BMPR2. In vitro assays conducted on KGN cells confirmed that hsa-miR-19b-3p promoted apoptosis, as evidenced by reduced cell viability, decayed mitochondrial membrane potential and increased apoptotic rate, thereby supporting its role in POF. Notably, hsa-miR-19b-3p was found to significantly downregulate BMPR2 expression via targeting its 3'UTR, while co-expression analysis revealed strong associations between BMPR2 and POF-related processes. This study sheds light on the epigenetic pathogenesis of POF by investigating exosomal miRNA profiles. Particularly, hsa-miR-19b-3p emerged as a potential regulator of BMPR2 and demonstrated its functional significance in POF through modulation of apoptosis.