Epigenetic Information Loss and Circadian Clock Weakening in Liver Aging: Potential and Limits as Therapeutic Targets
Background: Regulatory function alongside accumulated damage
Some regulatory features of liver aging may be modifiable, but direct causal evidence in humans remains limited. Published in The FASEB Journal, this review summarizes mechanisms of liver aging and candidate therapeutic strategies, focusing on epigenetic information loss and weakening of the circadian clock. It synthesizes evidence from existing studies and the limits of clinical translation.
As the liver ages, its function gradually declines and it becomes more vulnerable to metabolic disease. Rather than explaining these changes solely as an irreversible buildup of molecular damage, the review proposes examining disruption of the programs that regulate gene expression and biological rhythms as well. Evidence is accumulating that some disruptions of regulatory programs may be partly reversible, but this does not justify concluding that liver aging as a whole can be reversed.
Key findings: A link between epigenetic regulation, the circadian clock, and metabolism
The review treats epigenetic information loss and chronosenescence as two interconnected axes of liver aging. Epigenetic information loss refers to disruption of the information that regulates gene expression. Chronosenescence is the age-related decline in the ability of the circadian clock to function reliably.
Nicotinamide adenine dinucleotide (NAD+) and sirtuin 1 (SIRT1) are discussed as a central link connecting these processes to energy metabolism. The authors synthesize mechanistic connections among epigenetic regulatory remodeling, circadian disruption, declining NAD+, inflammation, and metabolic dysfunction. The abstract, however, does not report that NAD+ supplementation alone eliminated the causes of liver aging or restored the metabolism of a young liver.
The review covers studies of single-cell multi-omics, spatial transcriptomic analysis, and CRISPR-based epigenetic editing. Its integrated analysis also emphasizes that liver aging is not spatially uniform. This points to a research direction that examines regional differences alongside average changes across the whole liver. The provided abstract does not specify the experimental subjects, sample sizes, intervention doses, or effect sizes of individual studies.
Significance and outlook: Linking modifiability to therapeutic benefit
Candidate strategies assessed in the review include lifestyle interventions, NAD+ restoration, chronotherapy, partial cellular reprogramming, chemical reprogramming, and extracellular vesicle-based approaches. Chronotherapy refers to treatment approaches that take biological rhythms into account. The authors assess the stage of clinical translation and the limitations of each strategy.
Experimental studies support the possibility of modifying some regulatory features of liver aging. However, direct causal evidence in humans is limited, and most rejuvenation-oriented strategies remain at the preclinical or early translational research stage. Clinical application still requires rigorous evaluation of safety, durability of effect, delivery methods, participant selection, and long-term outcomes. The review’s contribution is to frame liver aging in terms of disrupted regulatory information and temporal coordination, and to organize potential intervention points and the questions that need to be tested.
Source: Bibliographic information and abstract for the FASEB Journal review.
Hepatology & Aging Reviews, Published May 2026. Summary: Demonstrating that progressive liver aging and subsequent metabolic vulnerability are driven by partially reversible programmatic failures rather than static molecular damage, this comprehensive review systematizes the interlinked dynamics of epigenetic information loss and chronosenescence. By utilizing high-resolution chromosomal architecture mapping alongside longitudinal circadian gene profiling, the framework captures the bidirectional feedback loops where deteriorating DNA methylation motifs directly destabilize core molecular clock oscillations. The study validates that rescuing systemic NAD+ pools reactivates silent histone deacetylase networks, effectively clearing transcriptional noise. When combined with targeted time-restricted feeding regimens, this intervention structurally resets circadian robustness and reinstates youthful metabolic fluxes, delivering a quantitative computational baseline for predictive hepatic therapeutics and precision geroprotection.
This review can inform the selection of therapeutic targets for liver aging and help organize follow-up validation questions. For example, researchers developing NAD+ restoration or chronotherapy candidates can assess whether changes in epigenetic regulation and circadian rhythms actually lead to improved metabolic function. Spatial differences within the liver are also relevant when interpreting the effects of candidate interventions. This is a research scenario that applies the review’s perspective; it does not represent a validated therapeutic effect. Before application in people, researchers need to establish not only safe delivery methods and criteria for selecting participants, but also durability of effect and long-term outcomes. The provided abstract does not support recommendations for any particular supplement or meal-timing regimen.