Functional dissection of ovarian aging-associated genes NDUFS5 and UBE2L3 through integrated genomic analyses and validation
Ovarian aging, culminating in menopause, involves a gradual decline in ovarian function. Genetic factors influencing age at natural menopause (ANM) especially premature ovarian insufficiency (POI) warrant further research. We employed a Bayesian framework to integrate a genome-wide association study (GWAS) on ANM (N=69,360) with an expression quantitative trait loci (eQTL) dataset (N=1,490), identifying 28 significant risk genes. Peripheral blood analysis from patients with POI and healthy controls, combined with RNA sequencing, differential gene (DEGs) expression analysis, and RT-qPCR verification, pinpointed MSH5, GAB2, NDUFS5, LST1, and UBE2L3 as top DEGs. NDUFS5 and UBE2L3 were aberrantly expressed in hydrogen peroxide or cyclophosphamide-treated human granulosa cells. Immunohistochemisty revealed decreased NDUFS5 and increased UBE2L3 expression in human ovarian samples of varying ages. NDUFS5 knockdown reduced granulosa cell proliferation and increased apoptosis in cell culture; UBE2L3 knockdown exhibited the opposite effect. Together, our findings indicate NDUFS5 and UBE2L3 as key risk genes involved in ovarian aging. Overall design: Peripheral blood samples were obtained from women diagnosed with POI and from women without ovarian disorders identified through physical examinations. Total RNA was isolated from PBMCs.