Describing the Epigenetic Mechanisms in Control of Hematopoietic Development and Rapid Inflammatory Responses

描述控制造血发育和快速炎症反应的表观遗传机制

• 批准号: 10490961
• 负责人: Andrew Daman
• 金额: $ 4.68万
• 依托单位: WEILL MEDICAL COLL OF CORNELL UNIV
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-01-31 至 2024-01-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10490961
• 关键词: Animal Model; Arginine; Bacterial Infections; Base Pairing; Biological Models; Biological Process; Biology; Blood; Blood Cells; Bone Marrow; Cell Differentiation process; Cell Line; Cell Lineage; Cell physiology; Cells; Chromatin; Collaborations; Complex; DNA biosynthesis; Data; Defect; Development; DiGeorge Syndrome; Disease; Enhancers; Epigenetic Process; Face; Foundations; Future; Gene Expression; Gene Expression Regulation; Genes; Genetic; Genetic Models; Genetic Transcription; Genome; Goals; Health; Hematopoiesis; Hematopoietic; Hematopoietic stem cells; Heterochromatin; High-Throughput Nucleotide Sequencing; Histone H3; Histones; Human; Immune; Immune response; Immunity; Individual; Infection; Inflammatory Response; Knock-out; Knowledge; Lentivirus; Link; Listeria; Lysine; Malignant Neoplasms; Maps; Modeling; Modification; Mus; Mutation; Myeloid Cells; Organism; Pathway interactions; Patients; Phenotype; Post-Translational Protein Processing; Process; Proteins; Reader; Regulation; Regulatory Pathway; Research; Role; Serine; Signal Transduction; Speed; Spleen; System; T-Lymphocyte; Tail; Testing; Tissues; Training; Variant; Vertebrates; Yeasts; adult stem cell; base; cell type; epigenetic regulation; exhaustion; experimental study; extracellular; fly; histone modification; in vivo; insight; interest; macrophage; mammalian genome; mouse model; mutant; novel; pathogen; progenitor; promoter; response; screening; stem cell survival; therapeutic target

Project Summary Complex organisms face daunting “epigenetic challenges”. How is a single genome interpreted to instruct over one thousand distinct cell fates? How do extracellular signals rapidly and robustly turn on select genes in the three billion base-pair genome? Epigenetic mechanisms underlie balanced blood cell differentiation and the speed and scope of cellular responses to pathogens or tissue damage—features that define immunity, tolerance, and survival during infection. Critical to understanding the mechanisms that “solve” these epigenetic challenges is the study of histones, proteins that package and regulate the genome. The focus of this project is to reveal the function of histones and histone post-translational modifications (PTMs) in mammalian organisms. Of particular interest is Histone variant H3.3, which represents 2 of 15 copies of H3 in the genome but is enriched in dynamically regulated chromatin such as enhancers, promotors and gene bodies. Additionally, H3.3 is the only H3 that is expressed in a DNA synthesis independent fashion. For these reasons we have focused on studying the function of H3.3 residues and modifications in hematopoietic development and immune cell function as these systems reflect complex mammalian development and rapid cellular responses, and are highly relevant to health and disease. Preliminary experiments focused on the function of co-transcriptional modification H3.3S31ph, and loss of this mark abrogates the ability of a macrophage cell line (RAW264.7s) to respond to LPS. To examine which other H3.3 residues and modifications are required for this rapid transcriptional response, I have developed a novel knockout and replacement system in BMDMs (Aim 1). Early results have shown that mutation of certain lysine residues to arginine (H3.3K4R, H3.3K36R) leads to decreased stimulation-induced transcription, whereas others (H3.3K9R, H3.3K27R) have no effect. To validate the functional relevance of these results, we have shown the requirement of H3.3 for in vivo immune response to listeria. Our results will inform ongoing studies to define dedicated mechanisms for rapid transcription. Additionally, we will use this model of knockout and replacement to determine the function of H3.3 and key residues in hematopoietic development (Aim 2). Initial experiments shown the requirement for H3.3 in hematopoietic stem cell survival, and macrophage differentiation. Targeted and unbiased screening of histone “readers, writers, and erasers” will enable us to link H3.3 mutant phenotypes to chromatin regulatory pathways and factors. Together these studies will elucidate how epigenetic mechanisms can regulate cellular differentiation and the speed and scope of cellular responses. By advancing basic knowledge of the epigenetic mechanisms regulating these cellular processes, the proposed research will have broad implications for basic biology and disease, as well as direct implications in bacterial infection and patients with H3.3 pathway mutations.

项目总结