Abstract
To understand the role of FoxO family members in hematopoiesis, we conditionally deleted FoxO1, FoxO3, and FoxO4 in the adult hematopoietic system. FoxO-deficient mice exhibited myeloid lineage expansion, lymphoid developmental abnormalities, and a marked decrease of the lineage-negative Sca-1+, c-Kit+ (LSK) compartment that contains the short- and long-term hematopoietic stem cell (HSC) populations. FoxO-deficient bone marrow had defective long-term repopulating activity that correlated with increased cell cycling and apoptosis of HSC. Notably, there was a marked context-dependent increase in reactive oxygen species (ROS) in FoxO-deficient HSC compared with wild-type HSC that correlated with changes in expression of genes that regulate ROS. Furthermore, in vivo treatment with the antioxidative agent N-acetyl-L-cysteine resulted in reversion of the FoxO-deficient HSC phenotype. Thus, FoxO proteins play essential roles in the response to physiologic oxidative stress and thereby mediate quiescence and enhanced survival in the HSC compartment, a function that is required for its long-term regenerative potential.
Publication types
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Research Support, N.I.H., Extramural
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Research Support, Non-U.S. Gov't
MeSH terms
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Animals
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Antioxidants / pharmacology
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Blood Cells / cytology
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Blood Cells / drug effects
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Blood Cells / metabolism*
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Bone Marrow / drug effects
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Bone Marrow / metabolism
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Bone Marrow / physiopathology
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Cell Cycle Proteins
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Cell Differentiation / genetics*
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Cell Lineage / drug effects
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Cell Lineage / genetics
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Cell Survival / drug effects
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Cell Survival / genetics
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Forkhead Box Protein O1
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Forkhead Box Protein O3
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Forkhead Transcription Factors / genetics*
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Gene Expression Regulation / physiology
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Hematopoiesis / drug effects
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Hematopoiesis / genetics*
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Hematopoietic Stem Cells / metabolism*
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Lymphocytes / cytology
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Lymphocytes / metabolism
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Mice
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Mice, Knockout
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Mice, Transgenic
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Myeloid Cells / cytology
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Myeloid Cells / metabolism
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Oxidative Stress / genetics*
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Reactive Oxygen Species / metabolism
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Transcription Factors / genetics
Substances
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Antioxidants
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Cell Cycle Proteins
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FOXO4 protein, human
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Forkhead Box Protein O1
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Forkhead Box Protein O3
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Forkhead Transcription Factors
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FoxO3 protein, mouse
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Foxo1 protein, mouse
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Reactive Oxygen Species
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Transcription Factors