The Polycentric Aging Framework Positions Epigenetic Change as the Dominant Mechanism of Aging
The presently available data and understanding of aging might be thought of as a jigsaw with more missing pieces than there are pieces in hand. There is a great deal of latitude to assemble what is known into a wide variety of views of the whole without being strongly contradicted in any of them. Thus theories of aging proliferate; it is always easier to theorize about existing puzzle pieces than to run a research program that will meaningfully add to the collection of puzzle pieces. Here, researchers present a framework for the relationship of the mechanisms of aging that places epigenetic change as the dominant (but not only) important process that drives loss of function, disease, and mortality.
Age-related dysfunction is unlikely to arise from a single universal mechanism. This review develops the Polycentric Aging Framework (PAF) by integrating evidence from somatic cell nuclear transfer (SCNT), DNA methylation (DNAm) clocks, nutrient-sensing pathways, cellular senescence, systemic signaling, and human intervention studies. PAF organizes aging into partially independent, interacting centers that differ in timing, causal status, resettability, reversibility, systemic influence, regenerative impact, interventional accessibility, and lifespan-limiting potential.
SCNT is interpreted not as rejuvenation of an existing organism but as a reset-hierarchy model: selected epigenetic and developmental states can be extensively reconfigured; telomere dynamics, mitochondrial state, proteostasis, stem-cell and stem cell niche capacity, and senescence and senescence-associated secretory phenotype (SASP) phenotypes show context-dependent reset, redevelopment, or recurrence; and nuclear DNA sequence and structural damage remain least resettable. In humans, PAF proposes epigenetic regulation as a dominant, but not exclusive, lifespan-limiting center because it coordinates cell identity, developmental-program persistence, nutrient sensing, inflammatory and endocrine signaling, repair, and tissue regeneration.
DNAm clocks are useful but incomplete biomarkers and may conflate pathological or causal Type 1 changes with adaptive or compensatory Type 2 responses. Clock shifts should therefore be interpreted against tissue-specific function, healthspan, morbidity, and mortality rather than as stand-alone evidence of rejuvenation. PAF predicts that intervention efficacy will depend on whether the targeted center is functionally limiting for a given tissue, disease context, and life stage, and whether another center subsequently becomes limiting. This provides a testable basis for center-specific geroprotective interventions combining controlled epigenetic reprogramming, metabolic modulation, senescence or SASP targeting, and systemic signaling modulation, with rigorous safety monitoring and tissue-context stratification.