DNMT/TET Imbalance and Network-Level DNA Methylation Remodeling in Ovarian Aging: Mechanistic Perspectives

Reproductive aging is characterized by progressive decline in ovarian reserve, reduced oocyte competence, and impaired endocrine coordination. Although these phenotypic changes are well documented, the molecular mechanisms that integrate aging-associated stress signals into coordinated ovarian dysfunction remain incompletely understood. Increasing evidence indicates that DNA methylation remodeling is closely associated with ovarian aging. Rather than representing isolated promoter-specific events, age-related methylation alterations may reflect progressive imbalance between DNA methyltransferases (DNMTs) and TET-mediated demethylation. Stress-responsive DNMT/TET dysregulation has been linked to distributed epigenetic remodeling across regulatory elements governing PI3K-AKT, TGF-β/SMAD, metabolic, and DNA damage response pathways in ovarian cell populations. We propose a network-level framework in which methylation drift preferentially affects highly connected regulatory hubs, potentially reducing transcriptional robustness and intercellular coordination within the follicular microenvironment. However, current human data remain largely correlative, and functional validation is required to determine whether methylation remodeling acts as a driver, amplifier, or biomarker of ovarian aging. Finally, we discuss translational implications, including circulating cell-free DNA signatures and epigenetic clock models, while emphasizing the importance of cell type-resolved and longitudinal studies. Collectively, the available evidence supports a model in which progressive DNMT/TET imbalance is associated with distributed pathway-level regulatory instability during ovarian aging.