A screen for epigenetic regulators of hematopoiesis reveals a requirement for the Hbo1 complex during hematopoietic stem cell specification

造血表观遗传调节因子的筛选揭示了造血干细胞特化过程中对 Hbo1 复合物的需求

• 批准号: 9247893
• 负责人: Katie L Kathrein
• 金额: $ 15.07万
• 依托单位: UNIVERSITY OF SOUTH CAROLINA AT COLUMBIA
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-04-13 至 2022-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9247893
• 关键词: Acetylation; Acetyltransferase; Adult; Alpha Cell; Animal Model; Award; Binding; Binding Sites; Biology; Blood; Blood Cells; Bone Marrow Transplantation; Boston; CD34 gene; Cell Differentiation process; Cell Lineage; Cell model; Cells; ChIP-seq; Chromatin; Chromatin Remodeling Factor; Chromatin Structure; Code; Complex; Cytokine Signaling; Defect; Development; Embryo; Endothelium; Ensure; Environment; Epigenetic Process; Erythroid Cells; Family member; Fertilization; Gene Expression; Gene Expression Regulation; Genes; Genetic; Genetic Screening; Hematological Disease; Hematologist; Hematology; Hematopoiesis; Hematopoietic; Hematopoietic stem cells; Histone Code; Histones; Homeostasis; Hour; Human; In Situ Hybridization; Individual; Inflammatory; Knowledge; Laboratories; Lead; Lymphoid Cell; MYB gene; Maintenance; Marrow; Mentors; Mentorship; Molecular; Mus; Mutation; Myeloid Cells; NF-kappa B; NFKB Signaling Pathway; NuRD complex; Orthologous Gene; Pathway interactions; Patients; Pediatric Hospitals; Polycomb; Post-Translational Protein Processing; Process; Proliferating; Proteins; Proto-Oncogene Proteins c-myb; Regulation; Research; Research Personnel; Research Project Grants; Research Training; Role; Scientific Advances and Accomplishments; Scientist; Seeds; Sickle Cell Anemia; Signal Pathway; Signal Transduction; Site; Stem cells; Thalassemia; Therapeutic; Tissues; To specify; Training; Training Programs; Transplantation; Umbilical Cord Blood Transplantation; Work; Zebrafish; blastocyst; chromatin remodeling; design; hematopoietic stem cell fate; histone modification; in vivo; knock-down; medical schools; member; novel; oncology; overexpression; prevent; public health relevance; response; reverse genetics; self-renewal; skills; success; therapeutic target; tool; transcription factor

 DESCRIPTION (provided by applicant): Long-term hematopoietic stem cells (HSCs) are capable of self- renewal and differentiation into all mature hematopoietic lineages. Cell specific transcription factors interact with co-factors to orchestrate chromatin structure and facilitate gene expression. To generate a compendium of factors that establish the epigenetic code in HSCs, I completed first large-scale in vivo reverse genetic screen targeting chromatin factors. To accomplish this task, I designed antisense morpholinos for 488 zebrafish orthologs of conserved human chromatin factors and the resultant morphants were analyzed by whole embryo in situ hybridization at 36 hours post fertilization for expression of two HSC specific genes, c- myb and runx1. 25 morpholinos caused near complete knockdown of HSC marker expression and 4 were found to increase HSC marker expression. Of the morpholinos that alter formation, several genes known to be essential for HSC self-renewal and maintenance were identified. For example, knockdown of Mll or Dot1 fail to specify HSCs, as indicated by a reduction in expression of the HSC markers. Reduced expression of six polycomb family members results in a decrease in HSC marker expression. Many of the remaining hits represent factors with no previous function ascribed in hematopoiesis, though some are components of known chromatin remodeling complexes, such as the Hat1 and Hbo1 complexes. The Hbo1 complex binds to target loci through one of the complex members, Ing4, which recognizes H3K4me3 marks. Four members of the Hbo1 complex were hits in this screen and I have found that these factors genetically interact in zebrafish embryos. No role for this complex has been shown previously in HSCs. Ing4 has also been shown to negatively regulate NF-B, tying the function of this complex to regulation of inflammatory signals in HSCs. This project will connect two important pathways, chromatin remodeling through acetylation and HSC response to inflammatory signals, offering new avenues to pursue in the study of histone modifications in HSCs and for therapeutic alternatives for patients with blood disorders. As a postdoctoral Research Fellow in Hematology/Oncology at the Children's Hospital Boston, Dr. Kathrein will perform her research project in the laboratory of Dr. Leonard Zon, a renowned hematologist, stem cell biologist, and zebrafish researcher. Building on her strong background of studying cell signaling mechanisms, Dr. Kathrein will expand her advanced scientific and technical knowledge to the regulation of hematopoietic cell specification determination using zebrafish as model organism. Under the mentorship of Dr. Zon and a prestigious mentoring committee, Dr. Kathrein has developed an ambitious research and training program that will equip her with highest research skills to ensure her success in the mentored and independent award period. The nurturing environment of the Children's Hospital Boston and the Harvard Medical School will provide the perfect surroundings for Dr. Kathrein's training to become a successful independent scientist.

 描述（由申请人提供）：长期造血干细胞（HSC）能够自我更新并分化为所有成熟的造血谱系。细胞特异性转录因子与辅助因子相互作用以协调染色质结构并促进基因表达。为了完成这项任务，我设计了反义序列，这是在 HSC 中建立表观遗传密码的因素的概要。受精后 36 小时，通过全胚胎原位杂交分析了 488 个人类染色质保守因子的斑马鱼直系同源物的吗啉代，分析了两个 HSC 特异性基因 c-myb 和 runx1 的表达，25 个吗啉代导致 HSC 标记几乎完全敲低。在改变形成的吗啉代中，有几个基因被发现是必需的。例如，Mll 或 Dot1 的敲低无法指定 HSC，如 HSC 标记物表达的减少所示，六个多梳家族成员的表达减少导致 HSC 标记物表达减少。许多剩余的命中代表以前在造血过程中没有功能的因子，尽管有些是已知的染色质重塑复合物的成分，例如与 Hbo1 复合物结合的 Hat1 和 Hbo1 复合物。通过识别 H3K4me3 标记的复合体成员之一 Ing4 的目标位点在此筛选中被命中，我发现这些因子在斑马鱼胚胎中发生遗传相互作用。 HSCs.Ing4 也被证明对 NF-κB 具有负调节作用，将该复合物的功能与 HSCs 中炎症信号的调节联系起来。通过乙酰化和 HSC 对炎症信号的反应进行染色质重塑，为研究 HSC 中的组蛋白修饰以及血液疾病患者的治疗替代方案提供了新途径。 Kathrein 将在著名血液学家、干细胞生物学家和斑马鱼研究员 Leonard Zon 博士的实验室中开展她的研究项目，该项目以她强大的细胞研究背景为基础。 Kathrein 博士将利用斑马鱼作为模型生物，将其先进的科学和技术知识扩展到造血细胞规格测定的调节。在 Zon 博士和著名的指导委员会的指导下，Kathrein 博士开展了一项雄心勃勃的研究和研究。培训计划将为她提供最高的研究技能，以确保她在指导和独立奖励期间取得成功。波士顿儿童医院和哈佛医学院的培养环境将为博士提供完美的环境。凯瑟琳接受训练，成为一名成功的独立科学家。