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（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特殊生态位内发生。粘附巨噬细胞-红系细胞相互作用对其完整性很重要，这有效地帮助红细胞从成红细胞成熟到去核网织红细胞。特定粘附分子和核缩合效应子的表达对此过程至关重要。然而，编码这些分子的基因的表达如何协调尚未确定。 EKLF/KLF1（红系 Kröppel 样因子）通过整合特定位点的转录和表观遗传信号，在红细胞生成中发挥全局作用。因此，值得考虑在分化的后期发挥这样的作用。这一猜想得到了以下实验的支持：分化小鼠胚胎干细胞、相关 EKLF 靶标的鉴定、其在发育过程中的早期和局部表达、EKLF 缺失的胎儿肝细胞表现出的缺陷、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中的红细胞表型。这些构成了以下目标的基础： 1-研究 EKLF 在早期发育期间和成人中的红细胞岛形成和完整性中的作用 2-详细阐述 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。 该提案旨在检验以下假设：EKLF 在红细胞岛生态位背景下紧密相连的两个过程中发挥协调作用：粘合剂 红细胞-巨噬细胞/细胞-细胞相互作用，以及红细胞去核。 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得到体内测定和 EKLF 救援系统的帮助。我们提出的实验提出并将解决一个令人兴奋的想法，即 EKLF 不仅在红细胞岛内红细胞中建立正确的基因表达模式方面发挥内在作用，而且还通过 外在机制基于其在岛巨噬细胞内的意外表达。 了解这些基本机制最终将有助于设计培养系统，从而能够有效扩增和去核人类细胞源以供临床使用。