TRANSCRIPTIONAL REGULATION IN STEM CELLS

阶段和组织特异的基因表达控制着 造血干细胞继续自我更新与其 增殖和分化为成熟的、有功能的造血细胞 细胞。该项目将重点研究ID家族的四个基因，它们编码 螺旋-环-螺旋(HLH)转录的重要负调控因子 因子族。假说；ID家族基因的差异表达 在细胞周期进程中，细胞因子诱导的造血干细胞 增殖和分化。这个家庭的成员已经被展示了 对一个品种的增殖和分化有深远的影响 造血细胞系。因此，我们建议身份证的成员- 家族调控造血干细胞增殖及其对 差异化。 I.四个ID家族基因的表达模式将在 小鼠造血细胞系的自我更新和诱导 差异化。四种内源性id家族基因的表达 将在同步生长期间、在增殖和 谱系选择性细胞因子诱导的分化。 二、ID基因过表达对生长发育和 小鼠造血细胞系的分化将通过 转录型或硒诱导型ID基因构建体的转染 受管制的平移控制。ID HLH调节器的能力 对细胞增殖和分化的影响将用 具有整合的、可调控表达结构的造血细胞系 个体ID家族基因。 将检测ID家族基因在造血干细胞中的表达 细胞及其过度表达对细胞周期的影响 去髓小鼠的进展、分化和植入。 转入受调控ID基因构建体的小鼠干细胞 通过对增殖的评估来检查过度表达的影响 和体外分化，以及分化和植入 在活体内。 这些研究的结果将促进我们对STEM的基本理解 细胞生物学将反过来促进骨髓研究的进一步进展 移植和基因治疗。

Stage-and tissue specific gene expression controls the ability of hematopoietic stem cells to continue self-renewal versus their proliferation and differentiation into mature, functional hematopoietic cells. This project will focus on the four Id family genes, which encode important negative regulators of the helix-loop-helix (HLH) transcription factor family. Hypothesis; Id family genes are differentially expressed in hematopoietic stem cells during cell cycle progression, cytokine-induced proliferation, and differentiation. Members of this family have been shown to have a profound effect on proliferation and differentiation in a variety of hematopoietic cell lines. Therefore, we propose that members of the Id- family regulate hematopoietic stem cell proliferation and its commitment to differentiation. I. The expression patterns of the four Id family genes will be examined in murine hematopoietic cell lines during self-renewal and induced differentiation. The expression of the four endogenous id family genes will be followed during synchronized growth, and during proliferation and differentiation induced by lineage-selective cytokines. II. The consequences of Id gene overexpression the growth and differentiation of murine hematopoietic cell lines will be tested by transfection of Id gene constructs under transcriptional or selenium- regulated translational control. The ability of Id HLH regulators to affect cell proliferation and differentiation will be assayed using hematopoietic cell lines with integrated, regulated expression constructs of individual Id family genes. III. Id family gene expression will be examined in hematopoietic stem cells and the consequences of overexpression determined on cell cycle progression, differentiation and engraftment into myeloablated mice. Murine stem cells transfected with regulated Id gene constructs will be examined for the effects of overexpression by evaluation of proliferation and differentiation in vitro, as well as on differentiation and engraftment in vivo. The results of these studies will advance our basic understanding of stem cell biology that will, in turn, promote further progress in bone marrow transplantation and gene therapy.