Distinct urinary exosomal microRNAs as biomarkers for differentiating premature ovarian insufficiency and menopause.

BACKGROUND: Premature ovarian insufficiency (POI) and natural menopause both involve cessation of ovarian function but occur at different life stages and arise from distinct etiologies. Differentiating between these conditions is essential for appropriate clinical management, particularly in women of reproductive age. Exosomes-extracellular vesicles containing regulatory microRNAs (miRNAs)-offer a promising, non-invasive source of biomarkers for various diseases, including ovarian dysfunction. This study investigated whether urinary exosomal miRNAs can serve as diagnostic markers to distinguish POI from menopause and explore their potential biological relevance. RESULTS: We validated POI-associated miRNA expression in urinary exosomes from 11 POI patients and 11 age-matched controls, confirming differential expression of seven candidate miRNAs. We then analyzed urinary exosomal miRNAs from 45 premenopausal and 45 postmenopausal women, which revealed distinct expression patterns: hsa-miR-4516 was consistently elevated in both POI and menopause, whereas hsa-let-7c-5p, hsa-let-7f-5p, and hsa-miR-29a-3p were downregulated in POI but upregulated in menopause. These menopausal expression patterns were mechanistically supported by a 4-vinylcyclohexene diepoxide (VCD)-induced ovarian failure mouse model, where target proteins of these miRNAs-including STAT3, BCL2, and BCL2L1-were downregulated and p53 was upregulated, consistent with apoptotic pathway activation. To assess diagnostic utility, receiver operating characteristic (ROC) analysis demonstrated strong diagnostic performance, with individual miRNAs yielding AUC values of 0.70 to 0.99 and a combined four-miRNA panel achieving an AUC of 0.99 for distinguishing POI from menopause. CONCLUSIONS: Urinary exosomal miRNAs demonstrate potential as non-invasive biomarkers for differentiating POI from menopause. Specifically, hsa-let-7c-5p, hsa-let-7f-5p, and hsa-miR-29a-3p may enable clinical distinction between these two conditions, while hsa-miR-4516 may serve as a general indicator of ovarian dysfunction. The combined miRNA panel demonstrated excellent diagnostic performance; however, these findings should be considered hypothesis-generating and require validation in larger, independent cohorts before clinical translation.