HIF-2
Menée in vitro et in vivo, cette étude met en évidence des mécanismes par lesquels, en régulant la production mitochondriale d'espèces réactives de l'oxygène, le facteur induit par l'hypoxie HIF-2
Hematopoietic stem and progenitor cells (HSPCs) are exposed to low levels of oxygen in the bone marrow niche, and hypoxia-inducible factors (HIFs) are the main regulators of cellular responses to oxygen variation. Recent studies using conditional knockout mouse models have unveiled a major role for HIF-1
α in the maintenance of murine HSCs; however, the role of HIF-2α is still unclear. Here, we show that knockdown of HIF-2α, and to a much lesser extent HIF-1α, impedes the long-term repopulating ability of human CD34+ umbilical cord blood cells. HIF-2α-deficient HSPCs display increased production of reactive oxygen species (ROS), which subsequently stimulates endoplasmic reticulum (ER) stress and triggers apoptosis by activation of the unfolded-protein-response (UPR) pathway. HIF-2α deregulation also significantly decreased engraftment ability of human acute myeloid leukemia (AML) cells. Overall, our data demonstrate a key role for HIF-2α in the maintenance of human HSPCs and in the survival of primary AML cells.
"HIF-2
α is essential for human HSPCs and acute myeloid leukemia survival
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HIF-2α regulates mitochondrial ROS production
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Silencing HIF-2α increases the endoplasmic reticulum stress induced by ROS
http://linkinghub.elsevier.com/retrieve/pii/S1934590913003743