Microsized inflammaging protects stem cells.

In this issue of Blood, Grants et al have identified connections between reduced expression of microRNA-146a (miR-146a), increased inflammation, impaired hematopoietic stem cell (HSC) quiescence, and a poor prognosis for acute myeloid leukemia (AML). miR-146a was originally identified as an anti-inflammatory microRNA that targets signaling proteins, which mediate inflammatory responses., Deletion of miR-146a in mice phenocopies many aspects of age-dependent inflammation,, termed “inflammaging.