Expression analysis of Chd7 in mouse hematopoietic stem and progenitor cells [microarray]

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. We performed gene expression analysis to determine the expression of chd7 in adult sorted HSPC populations. Loss of Chd7 in long term hematopoietic stem cells (LT-HSCs) results in upregulation of genes that function in hematopoietic system development and function. Genes representative of each blood lineage including erythroid, myeloid, and lymphoid were upregulated, suggesting that Chd7 deficiency results in LT-HSCs that are more primed for multilineage differentiation. Together with the physical and genetic interaction, the data support a model in which CHD7 interacts with and modulates Runx1 activity to provide proper timing and function of HSPCs as they emerge during hematopoietic development or mature in adults. This represents a distinct and evolutionarily conserved control mechanism to ensure accurate hematopoietic lineage differentiation. We used microarrays to detail the expression of Chd7 in adult sorted HSPC populations. To determine the expression of Chd7 in adult mouse HSPCs, long-term and short-term hematopoietic stem cells and multi-potent progenitor populations were sorted for microarray analysis.造血干细胞和祖细胞（hematopoietic stem and progenitor cell, HSPC）的形成与谱系分化，依赖于转录因子与表观遗传调控因子所调控的基因表达程序。敲低染色质域-解旋酶-DNA结合蛋白7（CHD7）可在斑马鱼与小鼠胚胎中扩增表型造血干细胞和祖细胞、红系及髓系细胞群体。CHD7在胚胎与成体个体中以细胞自主性方式抑制造血分化。我们开展了基因表达分析，以检测CHD7在成年分选的造血干细胞和祖细胞群体中的表达水平。长期造血干细胞（long term hematopoietic stem cells, LT-HSCs）中Chd7的缺失会导致造血系统发育与功能相关基因的表达上调。包括红系、髓系与淋系在内的各血液谱系代表性基因均出现上调，这提示Chd7缺陷会使长期造血干细胞更易被预致敏以进行多谱系分化。结合物理与遗传互作实验数据，本研究支持如下模型：CHD7通过相互作用并调控Runx1的活性，在造血发育阶段的造血干细胞和祖细胞产生过程，或是成体造血成熟过程中，为其提供恰当的时序调控与功能保障。这代表了一种独特且进化保守的调控机制，以确保造血谱系分化的精准性。我们借助基因芯片技术详细分析了Chd7在成年分选的造血干细胞和祖细胞群体中的表达情况。为检测Chd7在成年小鼠造血干细胞和祖细胞中的表达，我们分选了长期造血干细胞、短期造血干细胞及多能祖细胞群体用于基因芯片分析。