STAGE SPECIFIC EXPRESSION OF CD34 IN EARLY HEMATOPOIESIS

早期造血阶段 CD34 的阶段特异性表达

• 批准号: 6491731
• 负责人: Diane S Krause
• 金额: $ 1.05万
• 依托单位: YALE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1997
• 资助国家: 美国
• 起止时间: 1997-09-01 至 2002-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6491731
• 关键词: CD34 molecule; DNA binding protein; DNA footprinting; cell differentiation; cell line; cytokine; embryonic stem cell; gel mobility shift assay; gene expression; genetic enhancer element; genetic promoter element; genetic regulation; genetic transcription; genetic translation; hematopoiesis; hematopoietic stem cells; luciferin monooxygenase; molecular site; nucleic acid sequence; transcription factor; transfection

The long-term goal of this research program is use the CD34 gene as a tool to define the molecular mechanisms that regulate early hematopoiesis. CD34 is the only surface antigen yet identified that can be used to isolate hematopoietic reconstituting cells for human stem cell transplantation. Its expression is coordinately regulated with lineage commitment in hematopoietic differentiation such that CD34 is expressed on hematopoietic stem and progenitor cells, and as maturation progresses, its expression decreased such that mature blood cells are CD34 negative. Although much is known about the patterns of gene expression during hematopoietic differentiation, little is known about the transcriptional program of stem and elary progenitor cells. In order to address this important issue, the mechanisms that regulate murine CD34 gene expression will be elucidated. My work to date has identified two critical regions of the CD34 gene that confer tissue- specific expression on the promoter. The aims of this proposal are to determine the mechanisms by which these elements regulate CD34 expression, and to further define the critical elements of the CD34 gene that confer tissue-specific expression of CD34 vitro and in vivo. Transient transection analyses will be sued to determine regions of the D34 gene that promote tissue- specific expression. Then, using four murine cells lines that regulate up- or down- regulate CD34 expression in response to cytokines, regions of the murine CD34 gene that mediate tissue- and stage specific expression during hematopoiesis and differentiation will be delineated, and the protein factors that bind to defined critical regulatory regions of the CD34 gene will be identified. The work proposed is necessary to test the hypothesis that the mechanisms regulating CD34 expression also play an important role in determining whether a hematopoietic stem/progenitor cell will initiate hematopoietic differention or undergo self renewal. An understanding of the mechanisms that regulate CD34 will not only provide insight into pathways critical for normal early hematopoiesis and its disruption in leukemogenesis, but may also contribute to the development of novel strategies to maintain and expand hematopoietic stem cells for optimizing bone marrow reconstitution following myeloblative chemo- and radio-therapy. Also, a better understanding of the molecular control for early hematopoiesis will improve our ability to combat selective cytopenias and aplastic anemia.

该研究计划的长期目标是利用CD34基因作为 定义早期调节分子机制的工具 造血作用。 CD34 是迄今为止唯一确定的表面抗原 可用于分离人类造血重建细胞 干细胞移植。 其表达与协调调节 造血分化中的谱系定型使得 CD34 在造血干细胞和祖细胞上表达， 随着成熟的进展，其表达量下降，使得成熟的血液 细胞 CD34 阴性。 尽管人们对这些模式了解很多 造血分化过程中基因表达的变化目前知之甚少 关于干细胞和乳祖细胞的转录程序。 为了解决这个重要问题，监管机制 小鼠 CD34 基因表达将得到阐明。 我迄今为止的工作 已经确定了 CD34 基因的两个关键区域，它们赋予组织- 启动子上的特异性表达。 本提案的目的是确定机制 这些元件调节 CD34 表达，并进一步定义 CD34 基因的关键元件赋予组织特异性 CD34 的体外和体内表达。 瞬态横断面分析 将被起诉以确定 D34 基因中促进组织- 具体表达。 然后，使用四种小鼠细胞系来调节 响应细胞因子上调或下调 CD34 表达， 介导组织和阶段的鼠 CD34 基因区域 造血和分化过程中的特异性表达 描绘的，以及结合到定义的关键的蛋白质因子 CD34 基因的调控区域将被识别。 工作 提出的建议有必要检验该机制的假设 调节 CD34 的表达在决定 造血干/祖细胞是否会启动 造血分化或进行自我更新。 了解调节 CD34 的机制不仅有助于 深入了解正常早期造血的关键途径 及其对白血病发生的破坏，但也可能有助于 开发维持和扩大造血功能的新策略 干细胞用于优化骨髓重建 清髓性化疗和放疗。 也能更好的理解 早期造血的分子控制将改善我们的 对抗选择性血细胞减少症和再生障碍性贫血的能力。