Scientists reverse muscle aging in mice and discover a surprising catch

A UCLA study in mice reveals that aging muscle stem cells accumulate a protein that slows repair but boosts survival. This protein, NDRG1, acts like a brake, preventing cells from activating quickly after injury. When researchers blocked it in older mice, muscle healing sped up dramatically - but stem cells became less resilient over time. The work suggests aging may reflect a survival trade-off rather than straightforward decline.