In this issue of JEM, Umemoto et al. (https://doi.org/10.1084/jem.20180421) demonstrate that calcium influx stimulates mitochondrial metabolism and initiates proliferation in hematopoietic stem cells (HSCs). Extracellular adenosine, sourced from surrounding hematopoietic progenitors, inhibits this calcium influx, thereby suppressing mitochondrial metabolism and promoting HSC quiescence. This is the first demonstration that a calcium-mitochondria pathway regulates HSC division.
© 2018 Guitart et al.