TRANSCRIPTIONAL REGULATION IN STEM CELLS

阶段特异性和组织特异性基因表达控制着 造血干细胞继续自我更新， 增殖和分化成成熟的、功能性造血细胞 细胞 该项目将重点关注四个Id家族基因，它们编码 螺旋-环-螺旋（HLH）转录的重要负调节因子 因子家族 假设：Id家族基因差异表达 在造血干细胞的细胞周期进程中， 增殖和分化。 这个家族的成员 对多种细胞的增殖和分化产生深远的影响， 造血细胞系。 因此，我们建议，成员国的身份- 家族调节造血干细胞增殖及其承诺 分化 I. 四种Id家族基因的表达模式将在 小鼠造血细胞系在自我更新和诱导 分化 四种内源性id家族基因的表达 在同步生长期间，在增殖期间， 分化诱导的谱系选择性细胞因子。 二. Id基因过表达的后果是生长和 鼠造血细胞系的分化将通过 Id基因构建体在转录或硒- 调节翻译控制。 Id HLH调节剂的能力， 影响细胞增殖和分化将使用 具有整合的调控表达构建体的造血细胞系 身份证家族基因的区别 三. Id家族基因表达将在造血干细胞中检测 细胞和过表达的后果决定于细胞周期 进展、分化和移植到骨髓清除小鼠中。 将用受调节的Id基因构建体转染的鼠干细胞进行免疫组化。 通过评估增殖来检查过表达的影响 体外分化，以及分化和植入 in vivo. 这些研究结果将促进我们对茎的基本认识 细胞生物学，这将反过来促进骨髓的进一步发展， 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.