title: Colony-stimulating factor-1 requires PI3-kinase-mediated metabolism for proliferation and survival in myeloid cells.
abstract: Colony-stimulating factor-1 (CSF-1) is essential for macrophage growth, differentiation and survival. Myeloid cells expressing a CSF-1 receptor mutant (DeltaKI) show markedly impaired CSF-1-mediated proliferation and survival, accompanied by absent signal transducers and activators of transcription 3 (Stat3) phosphorylation and reduced PI3-kinase/Akt activity. Restoring phosphatidylinositol 3-kinase (PI3-kinase) but not Stat3 signals reverses the mitogenic defect. CSF-1-induced proliferation and survival are sensitive to glycolytic inhibitors, 2-deoxyglucose and 3-bromopyruvate. Consistent with a critical role for PI3-kinase-regulated glycolysis, DeltaKI cells reconstituted with active PI3-kinase or Akt are hypersensitive to these inhibitors. CSF-1 upregulates hexokinase II (HKII) expression through PI3-kinase, and PI3-kinase transcriptionally activates the HKII promoter. Moreover, HKII overexpression partially restores mitogenicity. In contrast, Bcl-x(L) expression does not enhance long-term proliferation, although short-term cell death is suppressed in a glycolysis-independent manner. This study identifies robust PI3-kinase activation as essential for optimal CSF-1-mediated mitogenesis in myeloid cells, in part through regulation of HKII and support of glycolysis.
authors.affiliation: Department of Pharmacology, University of Michigan Medical School, 1150W. Medical Center Dr., Ann Arbor, MI 48109, USA. awmlee@umich.edu
authors.forename: A W-M
authors.initials: AW
authors.lastname: Lee
authors.forename: D J
authors.initials: DJ
authors.lastname: States
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D020169:Caspases / Q000378:metabolism; D049109:Cell Proliferation / Q000187:drug effects*; D002470:Cell Survival / Q000187:drug effects; D004795:Enzyme Stability / Q000187:drug effects; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism; D006019:Glycolysis / Q000187:drug effects; D006593:Hexokinase / Q000378:metabolism; D006801:Humans; D016173:Macrophage Colony-Stimulating Factor / Q000494:pharmacology*; D051379:Mice; D050505:Mutant Proteins / Q000378:metabolism; D022423:Myeloid Cells / Q000166:cytology* / Q000187:drug effects*; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism*; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D016186:Receptor, Macrophage Colony-Stimulating Factor / Q000378:metabolism; D050796:STAT3 Transcription Factor / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects; D051020:bcl-X Protein / Q000378:metabolism
chemical_list: D050505:Mutant Proteins; D050796:STAT3 Transcription Factor; D051020:bcl-X Protein; D016173:Macrophage Colony-Stimulating Factor; D019869:Phosphatidylinositol 3-Kinases; D006593:Hexokinase; D016186:Receptor, Macrophage Colony-Stimulating Factor; D051057:Proto-Oncogene Proteins c-akt; D048049:Extracellular Signal-Regulated MAP Kinases; D020169:Caspases