HOMEOBOX GENE PITX2 EXPRESSION IN STEM CELLS

同源框基因 PITX2 在干细胞中的表达

• 批准号: 6336671
• 负责人: BERNARD G FORGET
• 金额: $ 30.98万
• 依托单位: YALE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-08-01 至 2001-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6336671
• 关键词: cell differentiation; cell growth regulation; developmental genetics; embryonic stem cell; flow cytometry; gene expression; gene targeting; hematopoiesis; hematopoietic stem cells; homeobox genes; laboratory mouse; tissue /cell culture; transfection /expression vector

Hematopoietic stem cells comprise a very small fraction of bone marrow mononuclear cells, which retain the capacity for self-renewal as well as controlled differentiation into all the cellular elements of the peripheral blood. The molecular signals that confer the stem cell phenotype and the mechanisms that control stem cell proliferation and differentiation are incompletely understood. In preliminary work, we have identify a divergent homeobox gene (Pitx2) that is expressed in murine hematopoietic stem/progenitor cells but not in differentiated cells. Our studies have demonstrated the expression of a novel mRNA isoforms of this gene in hematopoietic stem/progenitor cells and embryonic stem cells. The research goals of this proposal are to establish the role of this gene in hematopoiesis. Specifically, we propose to: characterize the temporal and over-expression of the gene (products) on hematopoietic progenitor cell growth and differentiation in vitro as well as in vivo: study the effects of loss of function of the gene in ES cells carrying targeted disruptions of the gene as well as in various hematopoietic cells expressing a dominant negative version of Pitx2; and characterize the downstream gene targets of Pitx2 as well as the elements that regulate the expression of Pitx2.

造血干细胞包含一小部分骨髓单核细胞，该细胞保留了自我更新的能力，并控制了分化为外周血的所有细胞元素。赋予干细胞表型的分子信号以及控制干细胞增殖和分化的机制尚不完全了解。在初步工作中，我们确定了在鼠造血干/祖细胞中表达的发散同源基因（PITX2），但在分化细胞中却没有。我们的研究表明，该基因在造血干/祖细胞和胚胎干细胞中的新型mRNA同工型的表达。该提案的研究目标是确定该基因在造血中的作用。具体而言，我们建议：表征基因（产物）对造血祖细胞细胞生长的时间和过表达，体外以及体内分化：研究ES基因功能丧失的ES细胞中基因功能丧失的影响，这些细胞带来了靶向靶向中断的基因中的靶向中断以及在各种血肿细胞中表现出占主导地位的负面负面的PITX2 PITX2 PITX2;并表征PITX2的下游基因靶标以及调节PITX2表达的元素。