Multiomic profiling reveals that prostaglandin E2 reverses aged muscle stem cell dysfunction, leading to increased...

Repair of muscle damage declines with age due to the accumulation of dysfunctional muscle stem cells (MuSCs). Here, we uncover that aged MuSCs have blunted prostaglandin E2 (PGE2)-EP4 receptor signaling, which causes precocious commitment and mitotic catastrophe. Treatment with PGE2 alters chromatin accessibility and overcomes the dysfunctional aged MuSC fate trajectory, increasing viability and triggering cell cycle re-entry. We employ neural network models to learn the complex logic of transcription factors driving the change in accessibility. After PGE2 treatment, we detect increased transcription factor binding at sites with CRE and E-box motifs and reduced binding at sites with AP1 motifs, overcoming the changes that occur with age. We find that short-term exposure of aged MuSCs to PGE2 augments their long-term regenerative capacity upon transplantation. Strikingly, PGE2 injections following myotoxin- or exercise-induced injury overcome the aged niche, leading to enhanced regenerative function of endogenous tissue-resident MuSCs and an increase in strength.