My laboratory has been engaged in studies of cellular and molecular aspects of globin gene regulation and erythropoiesis in general both at steady state and after stress for over 25 years. During that time several approaches were pioneered and employed in our research and these include: creation of heterospecific hybrid cells using human erythroid cells across all developmental spectrum; development of anti-human globin chain specific monoclonal antibodies; delineation of the kinetics of globin expression during differentiation of human erythroid cells cultured in vitro; first characterization of globin profile of erythroid cells differentiated from human ES cells and iPS cells; description of globin expression post transplantation of either adult of fetal cells. Methodological approaches employed for these studies include biochemical analyses of globins, el/sis, isoelectric focusing, HPLC, mRNA studies and epigenetic changes, i.e. methylation and DNAse HSS, immunofluorescence studies in cells and tissues.
Additional aspects of hematopoiesis/erythropoiesis studied include the impact of integrins, especially VLA-4 and beta-1 integrins, on the retention of stem/progenitor cells in bone marrow niches at baseline and on the stem cell self-renewal post transplantation; specifically on erythropoiesis beta-1 integrins contribute significantly to erythroid cell expansion and terminal differentiation post stress, whereas red cells generated in their absence have impaired response to ROS and shorter survival. These studies were enabled through the generation of conditional mouse models with deletion of specific integrins (alpha4beta1,alpha 5beta1,or all beta1 integrins) in either primitive hematopoietic cells, or specifically in erythroid cells. In addition to murine studies primates were used in some specific studies.
University of Washington School of MedicineDivision of Hematology, Box 3577101705 NE Pacific Street, HSB K-243Seattle, WA 98195-7710
Recent work involves gene editing approaches(through the use of Zink fingers, TALENs, or CRISP ) targeting binding sites of HbF –silencers in gamma promoters, or the BCL11A –erythroid specific enhancer ,in normal or thalassemic CD34+ cells, to reawaken fetal hemoglobin. The latter has an ameliorating clinical effect in all beta globin disorders.
Congenital and acquired disorders of globin and erythropoiesis
Over 300 journal publications and 54 others (book chapters, invited publications)