miR-379-5p promotes ovarian granulosa cell apoptosis in primary ovarian insufficiency by targeting KNDC1 and PEG10.

Background: Primary ovarian insufficiency (POI) is a heterogeneous disorder characterized by premature decline in ovarian function in women of reproductive age, yet its molecular mechanisms remain incompletely elucidated. MicroRNAs (miRNAs), as crucial post-transcriptional regulators, may play a crucial role in the onset and progression of POI. Our research sought to elucidate the regulatory roles and mechanisms of key miRNAs and their target genes in ovarian granulosa cells (GCs) from POI patients. Methods: Based on POI-related mRNA and miRNA microarray datasets obtained from GEO database, we employed bioinformatics methods to identify differentially expressed genes (DEGs) and performed functional enrichment analyses. The interactions between miRNAs and target genes were validated using dual-luciferase reporter assays. In POI cell models, following transfection with miRNA mimics or inhibitors using a lipid-based reagent, we assessed their effects on cell proliferation, apoptosis, and cell cycle progression using CCK-8 assays, flow cytometry, real-time quantitative PCR (qRT-PCR), and Western blotting. Finally, rescue experiments were conducted to further validate the underlying mechanism. Results: This study identified 590 DEGs and 610 differentially expressed miRNAs (DEMs) from microarray datasets, which were primarily enriched in processes including cell cycle regulation, chromosome segregation, and tubulin binding. Notably, miR-379-5p was significantly upregulated in the POI group. Intersection analysis of DEGs and predicted miR-379-5p targets identified two key genes, Kinase Non-catalytic C-lobe Domain Containing 1 (KNDC1) and Paternally Expressed Gene 10 (PEG10). Experimental validation confirmed that miR-379-5p was highly expressed in the POI GCs and directly targeted and suppressed the expression of KNDC1 and PEG10. miR-379-5p mimics reduced cell viability, increased apoptosis, and induced G0/G1 phase arrest. Conversely, miR-379-5p inhibition or KNDC1/PEG10 overexpression reversed these phenotypic changes. Conclusion: This study revealed elevated miR-379-5p expression in POI GCs, which induced cell cycle arrest and apoptosis by suppressing the expression of KNDC1 and PEG10. These findings provide a theoretical basis for understanding POI pathogenesis and for developing targeted therapeutic strategies centered on miR-379-5p.