Expression Profile of CHD7-Deficient Murine Long-term Hematopoietic Stem Cells

Hematopoietic stem and progenitor cell (HSPC) formation and lineage differentiation involve gene expression programs orchestrated by transcription factors and epigenetic regulators. Knockdown of the chromatin remodeler chromodomain-helicase-DNA-binding protein 7 (CHD7) expanded phenotypic HSPCs, erythroid, and myeloid lineages in zebrafish and mouse embryos. CHD7 acts to suppress hematopoietic differentiation in a cell autonomous manner in the embryo and adult. CHD7 chromatin immunoprecipitation in human CD34+ and mouse HSPCs revealed enrichment of binding motifs for hematopoietic transcription factors including Runx1 and GATA factors, and decreased Runx1 occupancy correlated with loss of CHD7 occupancy. CHD7 physically interacts with Runx1 and suppresses Runx1-induced expansion of HSPCs during development, providing both physical and genetic evidence for the Runx1-CHD7 interaction. CHD7 modulates Runx1 activity to provide proper timing and function of HSPCs as they emerge during hematopoietic development or mature in adults, representing a distinct and evolutionarily conserved control mechanism to ensure accurate hematopoietic lineage differentiation. We profiled expression of CHD7 wild-type and deficient adult mice bone marrow long-term hematopoietic stem cells and found genes from several hematopoietic lineages are upregulated. To examine hematopoietic gene expression in CHD7-deficient HSPCs, we purified 12-week adult mice bone marrow LT-HSCs (LSKCD48-CD150+) cells. We compared the expression profile from Chd7f/f and Chd7f/f;Vav1-Cre mice.