Transcription factor GATA-2 regulates quiescence of hematopoietic stem and progenitor cells

Control of haematopoietic stem cell (HSC) proliferation is critical in preventing bone marrow failure or haematological malignancy. Understanding the mechanisms that balance the requirement to restrain excessive HSC proliferation while allowing for production of blood cells and maintenance of the HSC pool is therefore of substantial clinical interest. Herein we discuss the nature of HSC quiescence and the role of the zinc finger transcription factor GATA2 in regulating a gene expression program which reversibly confers quiescence on HSCs and committed progenitors. We present data extending previous observations of reduced HSC and progenitor functionality in the context of enforced GATA2 expression, and begin to demonstrate the molecular mechanisms by which the GATA2 program appears to function in restraining HSC and progenitor cell proliferation. Conversely, we also show that Gata2 haploinsufficiency impacts the quiescent program of HSCs and committed progenitors, demonstrating that HSC proliferation is exquisitely responsive to either up or down-regulation of GATA2 level. Finally, we discuss the clinical manifestations of loss-of-function GATA2 mutations and high GATA2 expression in the pre-malignant myelodysplastic syndromes and myeloid leukaemi