The human ovary exhibits dynamic molecular remodeling in the decades post-menopause

Abstract

The human ovary is among the first organs to show age-related functional decline, resulting in menopause. Beyond this transition, the postmenopausal ovary is often regarded as quiescent and remains poorly characterized. We analyzed the proteomes of healthy, non-pathological ovaries using mass spectrometry (data-independent acquisition) from 28 postmenopausal women (50-75 years old), stratified into three age groups (50-59, 60-69, [≥]70). We quantified 5,812 protein groups and observed progressive age-associated shifts, with 117 proteins significantly altered in the [≥]70 vs 50-59 age comparison. Multivariate analysis demonstrated clear separation between 50-59 and [≥]70-year-old age cohorts, with protein signatures shifting from RNA/gene-regulatory functions in younger ovaries to metabolic, trafficking, and innate immune/complement pathways in older ovaries. Across differential abundance, multivariate modelling, and covariate-adjusted linear modelling, we identified a convergent set of age-associated proteins that were integrated into the 26-protein Buck Postmenopausal Ovary Molecular Signature (BuckPOMS), a consensus molecular signature capturing progressive extracellular matrix remodeling, inflammatory signaling, and loss of structural and keratin-associated proteins with age. Representative BuckPOMS proteins, including the secreted matrisome proteins WNT4 and Fibromodulin (FMOD), were validated by immunohistochemistry. Pathway enrichment further identified an increase in inflammatory and matrisome pathways, and increased abundance of damage-associated secretory factors decades following menopause. These data fundamentally shift the notion of the postmenopausal ovary as an inert organ and instead demonstrate active and continuous molecular remodeling that has potential relevance to tissue signaling and implications for womens health.