Written in bone: young bone makes young blood

Abstract

Ageing of bone marrow haematopoietic stem cells has been mostly associated with cell‐intrinsic mechanisms. New findings published in The EMBO Journal now show that reduced levels of the secreted matrix protein osteopontin in old bone marrow stroma cause ageing‐associated features in HSCs. In line, old HSCs are functionally rejuvenated by interaction with protease‐cleaved osteopontin fragment, and perform like young blood stem cells in vivo.