title: High GATA-2 expression inhibits human hematopoietic stem and progenitor cell function by effects on cell cycle.
abstract: Evidence suggests the transcription factor GATA-2 is a critical regulator of murine hematopoietic stem cells. Here, we explore the relation between GATA-2 and cell proliferation and show that inducing GATA-2 increases quiescence (G(0) residency) of murine and human hematopoietic cells. In human cord blood, quiescent fractions (CD34(+)CD38(-)Hoechst(lo)Pyronin Y(lo)) express more GATA-2 than cycling counterparts. Enforcing GATA-2 expression increased quiescence of cord blood cells, reducing proliferation and performance in long-term culture-initiating cell and colony-forming cell (CFC) assays. Gene expression analysis places GATA-2 upstream of the quiescence regulator MEF, but enforcing MEF expression does not prevent GATA-2-conferred quiescence, suggesting additional regulators are involved. Although known quiescence regulators p21(CIP1) and p27(KIP1) do not appear to be responsible, enforcing GATA-2 reduced expression of regulators of cell cycle such as CCND3, CDK4, and CDK6. Enforcing GATA-2 inhibited human hematopoiesis in vivo: cells with highest exogenous expression (GATA-2(hi)) failed to contribute to hematopoiesis in nonobese diabetic-severe combined immunodeficient (NOD-SCID) mice, whereas GATA-2(lo) cells contributed with delayed kinetics and low efficiency, with reduced expression of Ki-67. Thus, GATA-2 activity inhibits cell cycle in vitro and in vivo, highlighting GATA-2 as a molecular entry point into the transcriptional program regulating quiescence in human hematopoietic stem and progenitor cells.
authors.affiliation: Medical Research Council Molecular Haematology Unit, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, United Kingdom.
authors.forename: Alex J
authors.initials: AJ
authors.lastname: Tipping
authors.forename: Cristina
authors.initials: C
authors.lastname: Pina
authors.forename: Anders
authors.initials: A
authors.lastname: Castor
authors.forename: Dengli
authors.initials: D
authors.lastname: Hong
authors.forename: Neil P
authors.initials: NP
authors.lastname: Rodrigues
authors.forename: Lorenza
authors.initials: L
authors.lastname: Lazzari
authors.forename: Gillian E
authors.initials: GE
authors.lastname: May
authors.forename: Sten Eirik W
authors.initials: SE
authors.lastname: Jacobsen
authors.forename: Tariq
authors.initials: T
authors.lastname: Enver
mesh_terms: D000818:Animals; D017209:Apoptosis; D002453:Cell Cycle; D002478:Cells, Cultured / Q000166:cytology / Q000187:drug effects; D036101:Cord Blood Stem Cell Transplantation; D004958:Estradiol / Q000494:pharmacology; D005312:Fetal Blood / Q000166:cytology; D050989:GATA2 Transcription Factor / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology*; D005786:Gene Expression Regulation / Q000235:genetics; D005813:Genes, Synthetic; D018816:Genes, cdc; D006412:Hematopoietic Stem Cells / Q000166:cytology*; D006801:Humans; D007377:Interleukin-3 / Q000494:pharmacology; D051379:Mice; D016688:Mice, Inbred NOD; D016513:Mice, SCID; D011960:Receptors, Estrogen / Q000187:drug effects / Q000235:genetics; D011993:Recombinant Fusion Proteins / Q000502:physiology; D016192:Resting Phase, Cell Cycle; D013629:Tamoxifen / Q000494:pharmacology; D014158:Transcription, Genetic
chemical_list: D050989:GATA2 Transcription Factor; C494711:GATA2 protein, human; D007377:Interleukin-3; D011960:Receptors, Estrogen; D011993:Recombinant Fusion Proteins; D013629:Tamoxifen; D004958:Estradiol