Diverse interventions that extend mouse lifespan suppress shared age-associated epigenetic changes at critical gene regulatory regions.
Level 5 - mechanism / opinion, no new human data
Animal/bench research examining mouse liver epigenomics (CEBM level 5).
PubMed 28351383 · doi:10.1186/s13059-017-1185-3
What was done
Whole-genome, single-nucleotide level DNA methylation profiling was performed in liver tissue from wild-type mice fed an ad libitum diet to identify age-associated epigenetic changes. Researchers evaluated whether three longevity-extending interventions—the Ames dwarf (Prop1 df/df) mutation, calorie restriction, and rapamycin treatment—suppressed or modified these age-associated methylation patterns.
What was found
In control mice, age-associated hypomethylation was enriched at super-enhancers linked to highly expressed liver genes, which were also enriched for genes undergoing age-related expression changes. Hypermethylation with age was enriched at CpG islands marked with bivalent activating and repressing histone modifications, resembling patterns seen in liver cancer. Ames dwarfism and calorie restriction suppressed these age-associated methylation changes across the genome, whereas rapamycin treatment suppressed them more selectively and with less specificity. No exact numerical values, effect sizes, or p-values were reported in the abstract.
Why it matters
This study provides evidence that distinct longevity interventions (genetic, dietary, and pharmacological) converge on suppressing specific age-related epigenetic shifts, offering insight into the molecular mechanisms of the epigenetic clock and lifespan extension.
Limits
The study was conducted exclusively in mouse liver tissue, limiting generalizability to other organs and to humans. The abstract omits sample sizes, animal ages, treatment durations, and quantitative statistical metrics.
Cited by
- supports DNA methylation sites that lose methylation with aging are enriched in enhancer regions.