Regulation of hematopoietic stem and progenitor cell fate determination by Dpy30

Dpy30 对造血干细胞和祖细胞命运决定的调节

• 批准号: 9280925
• 负责人: Hao Jiang
• 金额: $ 33.08万
• 依托单位: UNIVERSITY OF ALABAMA AT BIRMINGHAM
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-06-15 至 2018-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9280925
• 关键词: ASH2L gene; Ablation; Address; Apoptosis; Binding; Biological Assay; Blood Cells; Bone Marrow; Catalytic Domain; Cell Differentiation process; Cell Fate Control; Cell Proliferation; Cell Transplants; Cell physiology; Cells; Chimera organism; Chromatin; Complex; Defect; Development; Developmental Biology; Developmental Gene; Disease; Drug Targeting; Enzymes; Epigenetic Process; Exhibits; Failure; Gene Expression; Gene Expression Profiling; Gene Expression Regulation; Genes; Genetic study; Hematological Disease; Hematopoiesis; Hematopoietic; Hematopoietic Neoplasms; Hematopoietic stem cells; Impairment; Knock-out; Knockout Mice; Knowledge; Lead; MLL gene; Maintenance; Mammals; Methylation; Molecular; Mus; Pancytopenia; Phenotype; Play; Positioning Attribute; Publishing; Regulation; Regulator Genes; Role; Stem cells; System; Testing; Therapeutic; Time; Transplant Recipients; Transplantation; Up-Regulation; Work; base; chromatin immunoprecipitation; embryonic stem cell; genome-wide; mouse model; mutant; novel therapeutics; public health relevance; reconstitution; self-renewal

 DESCRIPTION (provided by applicant): Many hematological diseases result from aberrant chromatin and gene regulation of the maintenance, proliferation and differentiation of hematopoietic stem and progenitor cells (HSPCs). As the major H3K4 methylation enzymes in mammals, the Set1/Mll complexes occupy a crucial position in developmental biology, and are considered potential drug targets for epigenetic therapeutics due to the intimate connection of H3K4 methylation with gene expression as well as the extensive association of several subunits in these complexes with diseases, including multiple blood cancers. However, it remains unclear how the H3K4 methylation activity of the Set1/Mll complexes regulates normal and abnormal hematopoiesis. We have previously established that Dpy30, a shared subunit of the Set1/Mll complexes, facilitates chromosomal H3K4 methylation, and is crucial for efficient differentiation of embryonic stem cells by facilitating the induction of many bivalently marked developmental genes. In this proposal, we will study the functional role of Dpy30 and its associated H3K4 methylation in HSPC fate determination using a Dpy30 conditional knockout (KO) mouse model that we recently generated. We have shown that the cellular H3K4 methylation level is markedly reduced in the Dpy30 KO mice. These mice develop severe pancytopenia and have profound defects in multilineage hematopoietic reconstitution, yet strongly accumulate phenotypic early HSPCs at the expense of more downstream hematopoietic cells, suggesting a block in hematopoietic differentiation. Further analyses in a competitive transplantation system also reveal profound defects in HSPC fate determination and in expression of key regulatory genes. These results allowed us to formulate our central hypothesis in this proposal -- Dpy30 is critical for HSPC cell fate determination through facilitating H3K4 methylation of key hematopoietic genes. We thus propose two specific aims to test this hypothesis: (1): To define the role of Dpy30 in HSC maintenance and HSPC differentiation. (2): To dissect the molecular mechanisms by which Dpy30 regulates HSPC function. By revealing a previous unrecognized role of the H3K4 methylation activity of the Set1/Mll complexes in regulating HSPC fate determination, this project will have important implications for developing therapeutic strategies against certain HSPC-based hematological diseases.

 描述（由申请人提供）：许多血液疾病是由染色质异常以及造血干细胞和祖细胞（HSPC）的维持、增殖和分化的基因调控引起的。作为哺乳动物中主要的 H3K4 甲基化酶，Set1/Mll 复合物在发育生物学中占据着至关重要的地位，并且由于 H3K4 甲基化与基因表达的密切联系以及这些复合物中的几个亚基与包括多种血癌在内的疾病的广泛关联，被认为是表观遗传治疗的潜在药物靶点。然而，Set1/Mll 复合物的 H3K4 甲基化活性如何调节正常和异常造血仍不清楚。我们之前已经确定，Set1/Mll 复合物的共享亚基 Dpy30 促进染色体 H3K4 甲基化，并且通过促进许多二价标记发育基因的诱导，对于胚胎干细胞的有效分化至关重要。在本提案中，我们将使用我们最近生成的 Dpy30 条件敲除 (KO) 小鼠模型来研究 Dpy30 及其相关 H3K4 甲基化在 HSPC 命运决定中的功能作用。我们发现 Dpy30 KO 小鼠的细胞 H3K4 甲基化水平显着降低。这些小鼠出现严重的全血细胞减少症，并且在多谱系造血重建方面存在严重缺陷，但以牺牲更多下游造血细胞为代价强烈积累表型早期 HSPC，表明造血分化受阻。对竞争性移植系统的进一步分析还揭示了 HSPC 命运决定和关键调控基因表达的严重缺陷。这些结果使我们能够在该提案中制定我们的中心假设——Dpy30 通过促进关键造血基因的 H3K4 甲基化而对于 HSPC 细胞的命运决定至关重要。因此，我们提出两个具体目标来检验这一假设：(1)：定义 Dpy30 在 HSC 维持和 HSPC 分化中的作用。 (2)：剖析Dpy30调节HSPC功能的分子机制。通过揭示 Set1/Mll 复合物的 H3K4 甲基化活性在调节 HSPC 命运决定中先前未被认识的作用，该项目将对开发针对某些基于 HSPC 的血液疾病的治疗策略具有重要意义。