Genome-wide Transcription Factor binding maps reveal cell-specific changes in the regulatory architecture of human HSPC [ChIPmentation]
Hematopoietic stem and progenitor cells (HSPCs) rely on a complex interplay of transcription factors (TFs) to regulate their differentiation into mature blood cells. A heptad of TFs - FLI1, ERG, GATA2, RUNX1, TAL1, LYL1, LMO2 - has been shown to bind to regulatory elements in bulk CD34+ HSPCs. However, whether specific combinations of these TFs have distinct roles in regulating hematopoietic differentiation remained unknown. In this study, we mapped the genome-wide binding profiles of these TFs and other chromatin-associated markers in distinct HSPC subsets (HSC, CMP, GMP, MEP). We found that the heptad occupancy and enhancer-promoter interactions varied significantly across cell types and were associated with cell-type specific gene expression. Moreover, we observed distinct regulatory elements that were enriched with specific combinations of TFs, such as stem-cell specific elements with ERG, and myeloid and megakaryocyte-erythroid specific elements with combinations of FLI1, RUNX1, GATA2, TAL1, LYL1, and LMO2. These findings suggest that specific combinations of TFs play critical roles in the regulation of hematopoietic differentiation, and provide a valuable resource for the development of targeted therapies to manipulate specific HSPC subsets. Overall design: ChIPmentation