Exp Hematol. 2021 Aug 28. pii: S0301-472X(21)00289-7. [Epub ahead of print]
Hematopoietic stem cells (HSCs) are immature blood cells that exhibit multi-lineage differentiation capacity. Homeostasis is critical for HSC potential and life-long hematopoiesis, and HSC homeostasis is tightly governed by both intrinsic molecular networks and microenvironmental signals. The evolutionarily conserved serine/threonine protein kinase B (PKB, also referred to as Akt) -mammalian target of rapamycin (mTOR) pathway is universal to nearly all multicellular organisms and plays an integral role in most cellular processes. Emerging evidence has revealed a central role of the Akt-mTOR network in HSC homeostasis, as it responses to multiple intracellular and extracellular signals and regulates various downstream targets, eventually affecting several cellular processes, including the cell cycle, mitochondrial metabolism, and protein synthesis. The dysregulated Akt-mTOR signaling greatly affects HSC self-renewal, maintenance, differentiation, survival, and autophagy, and aging, as well as transformation of HSCs to leukemia stem cells (LSCs). Here, we review recent works and provide an advanced understanding of how the Akt-mTOR network regulates HSC homeostasis, thus offering insights for future clinical applications.
Keywords: Akt-mTOR; Hematopoietic stem cells; Homeostasis; Leukemia stem cells