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: 9258426
• 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 2018-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9258426
• 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; Hemoglobin; Hepatocyte; Human; Integrin alpha4; Iron; Island; Kupffer Cells; Lead; Maps; Morphology; Mus; Myelogenous; Nuclear; Null Lymphocytes; Patients; Pattern; Peptides; Phagocytes; Phenotype; Physical condensation; Play; Process; Pronormoblasts; Regulation; Research; Reticulocytes; Role; Signal Transduction; Source; Structure; System; Testing; Zinc Fingers; base; cell type; cytokine; design; embryonic stem cell; erythroid Kruppel-like factor; experimental study; in vivo; macrophage; mutant; peripheral blood; progenitor; public health relevance; 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(申请人提供)：红细胞生成的终末分化事件不是孤立发生的，而是在一个被称为红母细胞岛的特殊利基内发生的。巨噬细胞和红系细胞的黏附相互作用对其完整性很重要，这有效地帮助红细胞从红系细胞成熟到去核网织红细胞。特定的黏附分子和核缩合效应因子的表达对这一过程都是至关重要的。然而，编码这些分子的基因是如何协调表达的还没有确定。EKLf/KLF1(red id Kr�ppel-like factor1)通过整合特定位点的转录和表观遗传信号，在红细胞生成中起着全球性的作用。因此，在分化的后期阶段发挥这样的作用值得考虑。这一猜想得到了以下实验的支持：小鼠胚胎干细胞的分化，相关EKLF靶点的鉴定，其在发育过程中的早期和定位表达，EKLF缺失的胎肝细胞所表现出的缺陷，EKLF表达模式的惊人扩展，以及先天性红细胞生成性贫血患者亚群的红细胞表型。这些构成了以下目标的基础：1-研究EKLF在早期发育和成人中红母细胞岛形成和完整性中的作用2-阐述EKLF在岛巨噬细胞中出人意料的作用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。这一提议旨在检验EKLF在两个过程中发挥协调作用的假设，这两个过程在红细胞岛生态位的背景下紧密相连：粘附剂 红系-巨噬细胞/细胞-细胞的相互作用，以及红细胞的去核。我们的研究建立在 在原代或最少操作的细胞中进行的观察，将得到活体分析和EKLF救援系统的帮助。我们提议的实验提出并将解决一个令人兴奋的想法，即EKLF不仅在红细胞岛内的红细胞中建立适当的基因表达模式方面发挥内在作用，而且它还通过一种 基于其在岛状巨噬细胞中意外表达的外在机制。了解这些基本机制最终将有助于设计培养系统，使人类细胞来源能够有效地扩增和去核，供临床使用。