Rejuvenation of aged hematopoietic stem cells.

Until recently, there was broad consensus in the stem cell aging field that the phenotype of aged hematopoietic stem cells (HSCs) is fixed-dominated by cell-intrinsic regulatory mechanisms that cannot be altered by pharmacological or genetic means. The conventional thinking was that HSC aging could not be reverted by therapeutic intervention. This paradigm has started to shift dramatically, primarily because hallmarks of aged HSCs have been successfully reverted by distinct experimental approaches by multiple laboratories. We will discuss in this review these hallmarks of HSCs aging and the novel approaches that successfully ameliorated or even reverted aging-associated hallmarks of aged HSCs.