title: Transcription factor Gfi-1 induced by G-CSF is a negative regulator of CXCR4 in myeloid cells.
abstract: The mechanisms underlying granulocyte-colony stimulating factor (G-CSF)-induced mobilization of granulocytic lineage cells from the bone marrow to the peripheral blood remain elusive. We provide evidence that the transcriptional repressor growth factor independence-1 (Gfi-1) is involved in G-CSF-induced mobilization of granulocytic lineage cells from the bone marrow to the peripheral blood. We show that in vitro and in vivo G-CSF promotes expression of Gfi-1 and down-regulates expression of CXCR4, a chemokine receptor essential for the retention of hematopoietic stem cells and granulocytic cells in the bone marrow. Gfi-1 binds to DNA sequences upstream of the CXCR4 gene and represses CXCR4 expression in myeloid lineage cells. As a consequence, myeloid cell responses to the CXCR4 unique ligand SDF-1 are reduced. Thus, Gfi-1 not only regulates hematopoietic stem cell function and myeloid cell development but also probably promotes the release of granulocytic lineage cells from the bone marrow to the peripheral blood by reducing CXCR4 expression and function.
authors.affiliation: Laboratory of Cellular Oncology, Center for Cancer Research, National Cancer Institute (NCI), National Institutes of Health (NIH), Bethesda, MD 20892, USA.
authors.forename: Maria
authors.initials: M
authors.lastname: De La Luz Sierra
authors.forename: Paola
authors.initials: P
authors.lastname: Gasperini
authors.forename: Peter J
authors.initials: PJ
authors.lastname: McCormick
authors.forename: Jinfang
authors.initials: J
authors.lastname: Zhu
authors.forename: Giovanna
authors.initials: G
authors.lastname: Tosato
mesh_terms: D000818:Animals; D002454:Cell Differentiation / Q000187:drug effects; D002460:Cell Line; D019070:Cell Lineage / Q000276:immunology; D049109:Cell Proliferation / Q000187:drug effects; D004268:DNA-Binding Proteins / Q000378:metabolism*; D015536:Down-Regulation; D016179:Granulocyte Colony-Stimulating Factor / Q000494:pharmacology*; D006098:Granulocytes / Q000166:cytology / Q000276:immunology / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D022423:Myeloid Cells / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism*; D011401:Promoter Regions, Genetic / Q000235:genetics; D012333:RNA, Messenger / Q000235:genetics; D019718:Receptors, CXCR4 / Q000235:genetics / Q000378:metabolism*; D014157:Transcription Factors / Q000378:metabolism*; D014158:Transcription, Genetic / Q000235:genetics
chemical_list: D004268:DNA-Binding Proteins; C079873:Gfi1 protein, mouse; D012333:RNA, Messenger; D019718:Receptors, CXCR4; D014157:Transcription Factors; D016179:Granulocyte Colony-Stimulating Factor