Stem/Progenitor Cell Inversions With Cell Cycle Transit

干细胞/祖细胞反转与细胞周期转变

• 批准号: 7250223
• 负责人: GERALD ALEXANDER COLVIN
• 金额: $ 12.54万
• 依托单位: RHODE ISLAND HOSPITAL
• 依托单位国家: 美国
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-08-01 至 2008-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7250223
• 关键词: Adhesions; Back; Biological Assay; Blood Cells; CSF3 gene; CXCR4 gene; Cell Cycle; Cell Separation; Cell surface; Cells; Class; Cultured Cells; Cytokine Receptors; Data; Engraftment; Epitopes; Erythropoietin; G1 Phase; Grant; Granulocyte-Macrophage Colony-Stimulating Factor; Hematopoiesis; Hematopoietic; Hematopoietic stem cells; In Vitro; Incidence; Integrins; Interleukin-11; Interleukin-2; Interleukin-3; Interleukin-3 Receptor; Interleukin-6; Interleukin-7; L-Selectin; Label; Lead; Ligands; Link; Liquid substance; Macrophage Colony-Stimulating Factor; Maps; Marrow; Masks; Megakaryocytes; Modeling; Mus; Nature; Numbers; Phenotype; Population; Pre-Clinical Model; Process; Production; Property; Proteins; Research Personnel; Rhodamine; Rhodamines; Speed; Stem Cell Factor; Stem cells; System; Teflon; Testing; Thrombopoietin; Thymidine; Transplantation; Treatment Protocols; Work; adhesion receptor; base; cellular imaging; cytokine; design; granulocyte; human FLT3LG protein; in vivo; interest; macrophage; progenitor; programs; response; stem

DESCRIPTION (provided by applicant): The process of blood cell formation (hematopoiesis) has been extensively studied but many basic mechanisms continue to be unknown. Previous studies have shown that marrow cell engraftment varies at different points in cell cycle and that these changes are reversible. In recent work we have shown that murine progenitor numbers also vary with cytokine induced cell cycle transit. Studying unseparated marrow cells we demonstrated that 7-factor responsive progenitors (HPP-CFC and CFU-c) increased markedly during the first cell cycle transit and then returned to baseline. Remarkably, these increases were tightly linked to the decreased ability of stem cells to engraft in a competitive transplant model. This phenomenon is termed stem/progenitor cell inversions. These data suggest that the functional phenotype of early marrow stem cells shifts reversibly from engraftable stem cell to progenitor and back to hematopoietic stem cell as it traverses cell cycle, and that the previously conceived stem-cell-to-progenitor unidirectional hierarchy is instead a continuum of reversible phenotypic shifts. The long term objective of this grant are to further characterize the cell cycle related inversions points as to engraftment, progenitor levels and differentiation capacity of the marrow cells studying both unseparated and highly purified stem cells in FLT-3 ligand, thrombopoietin and steel factor. We plan to assess lineage(negative) rhodamine(low) Hoechst(low) (LRH) marrow cells at different points in cell cycle as to short and long-term engraftment in a competititive transplant model, to assess 7-factor-responsive progenitors and to evaluate the capacity of purified stem cells to differentiate in the presence a 7-factor cytokine cocktail and two cocktails designed to promote granulocyte-macrophage or megakaryocyte differentiation. In the engraftment studies there will be an emphasis on G1 phase of cell cycle. The differentiation studies will be carried out in bulk Teflon cultures and on a single cell clonal basis. In order to further understand the phenotype of the stem cell at different points in cell cycle. To point ways to alternative induction studies we will characterize cytokine receptors, adhesion proteins, integrins and other epitopes on the cell surface. These studies employ high-speed cell sorting, fluorescent cell imaging and a variety of in vitro and in vivo stem/progenitor assays. They promise to further define the basic nature of the hematopoietic marrow stem cells and could lead to interesting preclinical models for selective lineage support of various myeloablative therapy approaches .

描述（由申请人提供）： 血细胞形成（造血）的过程已被广泛研究，但许多基本机制仍然未知。以前的研究表明，骨髓细胞移植在细胞周期的不同点是不同的，这些变化是可逆的。在最近的工作中，我们已经表明，小鼠祖细胞数量也随着细胞因子诱导的细胞周期转运而变化。研究未分离的骨髓细胞，我们证明，7-因子反应祖细胞（HPP-CFC和CFU-c）显着增加，在第一个细胞周期过境，然后返回到基线。值得注意的是，这些增加与干细胞在竞争性移植模型中移植能力的降低密切相关。这种现象被称为干/祖细胞倒置。这些数据表明，早期骨髓干细胞的功能表型可逆地从可移植干细胞转移到祖细胞，并返回造血干细胞，因为它穿越细胞周期，而以前设想的干细胞祖细胞单向层次结构，而不是一个连续的可逆表型转变。该基金的长期目标是进一步表征细胞周期相关的逆转点，如骨髓细胞的植入、祖细胞水平和分化能力，研究FLT-3配体、血小板生成素和钢因子中未分离和高度纯化的干细胞。我们计划评估谱系（阴性）罗丹明（低）Hoechst（低）（LRH）骨髓细胞在细胞周期的不同点，以短期和长期的移植在竞争性移植模型，以评估7-因子反应的祖细胞和评估纯化的干细胞的能力，分化的存在下，7-因子细胞因子鸡尾酒和两个鸡尾酒设计，以促进粒细胞-巨噬细胞或巨核细胞分化。在植入研究中，将重点关注细胞周期的G1期。分化研究将在散装Teflon培养物中进行，并以单细胞克隆为基础。为了进一步了解干细胞在细胞周期不同点的表型。为了指出替代诱导研究的方法，我们将表征细胞因子受体，粘附蛋白，整合素和细胞表面上的其他表位。这些研究采用高速细胞分选、荧光细胞成像和各种体外和体内干/祖细胞测定。它们有望进一步确定造血骨髓干细胞的基本性质，并可能导致有趣的临床前模型，用于各种清髓性治疗方法的选择性谱系支持。