If you have noticed that a sore muscle that would have recovered in two days now takes five, or that a minor injury that healed quickly at 30 lingers for weeks at 65, science now has a specific molecular explanation for why, and a surprising complexity in what fixing it might involve.
A new UCLA study found that stem cells in aged muscle accumulate higher levels of a protein called NDRG1 that slows their ability to activate and repair tissue, but helps the cells survive longer in the harsh environment of aging tissue. The research team, led by postdoctoral scholars Jengmin Kang and Daniel Benjamin and senior author Dr. Thomas Rando, discovered that NDRG1 increased dramatically with age — reaching levels 3.5 times higher in old cells than in young cells.
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