[PDF][PDF] TNF-α coordinates hematopoietic stem cell survival and myeloid regeneration

M Yamashita, E Passegué - Cell stem cell, 2019 - cell.com
M Yamashita, E Passegué
Cell stem cell, 2019cell.com
Inflammation coordinates tissue regeneration via damaged cell removal and stem cell
activation. Hematopoietic stem cells (HSCs) survive inflammatory stress that kills other blood
cells, but the mechanisms underlying this effect remain poorly understood. Here, we find that
tumor necrosis factor α (TNF-α) acts differently on HSCs and progenitors, thus facilitating
hematopoietic clearance and promoting regeneration. We show that while inducing myeloid
progenitor apoptosis, TNF-α promotes HSC survival and myeloid differentiation by activating …
Summary
Inflammation coordinates tissue regeneration via damaged cell removal and stem cell activation. Hematopoietic stem cells (HSCs) survive inflammatory stress that kills other blood cells, but the mechanisms underlying this effect remain poorly understood. Here, we find that tumor necrosis factor α (TNF-α) acts differently on HSCs and progenitors, thus facilitating hematopoietic clearance and promoting regeneration. We show that while inducing myeloid progenitor apoptosis, TNF-α promotes HSC survival and myeloid differentiation by activating a strong and specific p65-nuclear factor κB (NF-κB)-dependent gene program that primarily prevents necroptosis rather than apoptosis, induces immunomodulatory functions, and poises HSCs for myeloid cell production. These TNF-α-driven mechanisms are critical for HSC response to inflammatory stress but are also hijacked in aged and malignant HSCs. Our results reveal several TNF-α-mediated pro-survival mechanisms unique to HSCs, highlight an important role for necroptosis in HSC killing, and establish TNF-α as a major pro-survival and pro-regeneration factor for HSCs.
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