Histone Lactylation Antagonizes Senescence and Skeletal Muscle Aging by Modulating Aging-Related Pathways [snRNA-seq]

Epigenetic alterations are among the prominent drivers of cellular senescence and/or aging. In this study, we show that histone lactylation plays a pivotal role in counteracting senescence and mitigating dysfunctions of skeletal muscle in aged mice. Mechanistically, histone lactylation and lactyl-CoA levels markedly decrease during cellular senescence but are restored under hypoxic conditions primarily due to elevated glycolytic activity. The enrichment of histone lactylation at promoters is essential for sustaining the expression of genes involved in the cell cycle and DNA repair pathways, thereby inhibiting cellular senescence. Furthermore, the modulation of enzymes crucial for histone lactylation, including p300 and HDAC1, leads to reduced histone lactylation and accelerated cellular senescence. Consistently, the suppression of glycolysis and the depletion of histone lactylation are also observed during skeletal muscle aging. Modulating the enzymes also leads to the loss of histone lactylation in skeletal muscle, downregulating DNA repair and proteostasis pathways and accelerating muscle aging. Running exercise increases the levels of glycolysis and histone lactylation, thereby helping to preserve the proper function of skeletal muscle. Our study highlights the significant roles of histone lactylation in modulating cellular senescence and muscle aging, suggesting that this modification may serve as an innovative biomarker for senescence.