Sprouting a new take on stem cell aging

Age associated changes in stem cell function are widely implicated as having a causal role to the declines in tissue function, homeostasis and regenerative ability that accompany aging. However, the signals and mechanisms that lead to altered stem cell functionality in aging are unclear. A recent study published in Nature (Chakkalakal et al, 2012) proposes a unique mechanism whereby a signal from the aged niche causes a cell autonomous and persistent change in the ability of a stem cell to maintain the quiescent state, which, over time, leads into impaired tissue regenerative capacity.