Loss of cGAS, contrary to prior therapeutic targeting assumptions, shortens both lifespan and healthspan in mice by disrupting H3K9me3-mediated silencing of LINE1 retrotransposons. This reveals that cGAS functions as a suppressor of genomic instability rather than a driver of inflammaging, reversing the rationale for cGAS inhibition as an anti-aging strategy.
Key Points
- cGAS knockout reduces median lifespan and healthspan in mice
- cGAS loss derepresses LINE1 retrotransposons via H3K9me3 disorganization
- cGAS acts as genomic stabilizer, not inflammaging driver
Longevity Analysis
This finding fundamentally reframes cGAS as a protective mechanism against transposable element activation rather than a pathogenic driver of aging inflammation. When cGAS is absent, the cell's capacity to maintain epigenetic silencing of repetitive elements deteriorates, permitting LINE1 activation that accelerates cellular aging and tissue dysfunction. The research demonstrates that blocking cGAS—pursued in earlier aging studies—may paradoxically accelerate decline. Rather than targeting pathway suppression, the therapeutic opportunity lies in supporting the machinery that maintains H3K9me3 landscape integrity and transposon containment, particularly as cells accumulate damage and epigenetic control loosens with age.
Original published by Nature Aging.