In aging rat testes, loss of the DNA methyltransferase DNMT1 removes methylation restraint on the Fto promoter, raising FTO levels and stripping m6A marks from Hsp90aa1 mRNA. The resulting drop in HSP90AA1 weakens AKT signaling, increases Leydig cell apoptosis, and reduces testosterone output; restoring DNMT1 reversed the senescent phenotype and recovered steroidogenic capacity.
Key Points
- DNMT1 declines in aging testes alongside falling testosterone levels
- Reduced DNMT1 raises FTO, lowering Hsp90aa1 m6A and HSP90AA1 protein
- DNMT1 restoration reversed Leydig cell senescence and renewed testosterone synthesis
Longevity Analysis
Age-related testosterone decline is framed here not as simple glandular exhaustion but as an epigenetic control failure — DNA methylation and RNA methylation operating in sequence to determine whether hormone-producing cells survive or apoptose. That distinction matters clinically: it separates the question of replacing a hormone from the question of preserving the cells that make it, and it identifies a specific upstream node where intervention could maintain endogenous output. The same methylation machinery governs cell survival signaling well beyond the gonad, placing reproductive aging within the broader arithmetic of tissue regeneration and hormonal signal integrity.
Original published by Wiley Aging Cell, by Yaqi Li, Yulei Duan, Zihang Tian, Yibing Gao, Yufei Qiao, Shuang Zhao, Wenyan Li, Zheng Gao, Siyun Niu .