Intrinsic and extrinsic control of erythropoietic maturation

红细胞生成成熟的内在和外在控制

• 批准号: 9042359
• 负责人: JAMES J BIEKER
• 金额: $ 36.87万
• 依托单位: ICAHN SCHOOL OF MEDICINE AT MOUNT SINAI
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-04-01 至 2018-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9042359
• 关键词: Address; Adhesives; Adult; Affect; Biological Assay; Cell Adhesion Molecules; Cell Communication; Cell Line; Cell Maturation; Cell Nucleus; Cell Surface Proteins; Cells; Chromatin; Clinical; Complement; Congenital dyserythropoietic anemia; Defect; Deoxyribonucleases; Development; Differentiation and Growth; Epigenetic Process; Erythroblasts; Erythrocytes; Erythroid; Erythroid Cells; Erythropoiesis; Evaluation; Event; Exhibits; Fetal Liver; Gene Expression; Gene Expression Profile; Gene Expression Regulation; Gene Targeting; Genetic Transcription; Globin; HDAC2 gene; Hepatocyte; Human; Integrin alpha4; Iron; Island; Kupffer Cells; Lead; Maps; Mus; Myelogenous; Nuclear; Null Lymphocytes; Patients; Pattern; Peptides; Phenotype; Physical condensation; Play; Process; Pronormoblasts; Regulation; Research; Reticulocytes; Role; Signal Transduction; Source; Staging; Structure; System; Testing; Zinc Fingers; base; cell type; cytokine; design; embryonic stem cell; erythroid Kruppel-like factor; in vivo; macrophage; mutant; peripheral blood; progenitor; public health relevance; research study; three dimensional structure; transcription factor

DESCRIPTION (provided by applicant): The terminal differentiation events of erythropoiesis do not occur in isolation, but rather within a specialized niche known as the erythroblastic island Adhesive macrophage-erythroid cell interactions are important for its integrity, which efficiently aid the red cell maturation progression from erythroblast to enucleated reticulocyte. Expression of specific adhesion molecules and nuclear condensation effectors each are critical for this process. However, how expression of the genes encoding these molecules is coordinated is not established. EKLF/KLF1 (erythroid Kr¿ppel-like factor) plays a global role in erythropoiesis by integrating transcriptional and epigenetic signals at specific loci. As a result, it merits consideration for performing such a role at late stages of differentiation. Such a conjecture is supported by experiments in differentiating murine embryonic stem cells, identification of relevant EKLF targets, its early and localized expression during development, deficiencies exhibited by EKLF-null fetal liver cells, the surprising expansion of EKLF expression pattern, and the red cell phenotype in a subset of congenital dyserythropoietic anemia patients. These form the basis for the following aims: 1-Investigate the role of EKLF in erythroblastic island formation and integrity during early development and in the adult 2-Elaborate on EKLF's unexpected role in the island macrophage 3-Utilize a proliferation/differentiation system of primary erythroid cells to address EKLF's ability to coordinate nuclear maturation events. This proposal is designed to test the hypothesis that EKLF plays a coordinating role in two processes that are intimately interconnected within the context of the erythroblastic island niche: adhesive erythroid-macrophage/cell-cell interactions, and enucleation of the red cell. Our studies build on observations made in primary or minimally manipulated cells that will be aided by in vivo assays and EKLF rescue systems. Our proposed experiments raise and will address the exciting idea that EKLF not only plays an intrinsic role in establishing the proper gene expression patterns in the red cell within the erythroblastic island, but that it additionally affects this process by an extrinsic mechanism based on its unanticipated expression within the island macrophage. Understanding these basic mechanisms will ultimately aid in the design of culture systems that enable efficient expansion and enucleation of human cell sources for clinical use.

描述（由申请人提供）：红细胞生成的终末分化事件不是孤立发生的，而是在称为成红细胞岛的专门小生境内发生的。粘附性巨噬细胞-红系细胞相互作用对于其完整性是重要的，其有效地帮助红细胞从成红细胞成熟进展为无核网织红细胞。特异性粘附分子和核凝聚效应物的表达对于这一过程都是至关重要的。然而，编码这些分子的基因的表达是如何协调的尚未确定。EKLF/KLF 1（红系Kr？ppel样因子）通过在特定基因座整合转录和表观遗传信号而在红细胞生成中起全局作用。因此，值得考虑在分化后期发挥这种作用。这种推测得到了以下实验的支持：分化小鼠胚胎干细胞，鉴定相关的EKLF靶点，其在发育过程中的早期和局部表达，EKLF缺失的胎肝细胞表现出的缺陷，EKLF表达模式的惊人扩增，以及先天性红细胞生成障碍性贫血患者亚群中的红细胞表型。研究EKLF在成红细胞岛形成和完整性中的作用 2-阐述EKLF在岛巨噬细胞中的意想不到的作用 3-利用原代红系细胞的增殖/分化系统来解决EKLF协调核成熟事件的能力。 该建议旨在检验EKLF在两个过程中起协调作用的假设，这两个过程在成红细胞岛生态位的背景下密切相关：粘附 红细胞-巨噬细胞/细胞-细胞相互作用和红细胞去核。 我们的研究建立在 在原代或最低限度操作的细胞中进行的观察，将通过体内测定和EKLF拯救系统进行辅助。我们提出的实验提出并将解决一个令人兴奋的想法，即EKLF不仅在成红细胞岛内红细胞中建立适当的基因表达模式中起内在作用，而且它还通过一种新的途径影响这一过程。 基于其在岛巨噬细胞内的非预期表达的外在机制。 了解这些基本机制将最终有助于设计培养系统，使有效的扩增和去核人类细胞来源的临床使用。