Role of Cited2 in Hematopoiesis

Cited2 在造血中的作用

• 批准号: 7691250
• 负责人: YU-CHUNG YANG
• 金额: $ 39.25万
• 依托单位: CASE WESTERN RESERVE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-09-25 至 2012-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7691250
• 关键词: Address; Adult; Apoptosis; Biological; Biological Assay; Biology; Bone Marrow; Cell physiology; Cells; Cellularity; Colony-Forming Units Assay; Competitive Binding; Complex; D-Aspartic Acid; Defect; Development; EP300 gene; Embryo; Family; Fetal Liver; Frequencies; Functional disorder; Gene Expression; Gene Transfer; Genes; Glutamic Acid; Goals; Hematologic Neoplasms; Hematopoiesis; Hematopoietic; Hepatocyte; Hypoxia; In Vitro; Knock-out; Knockout Mice; Knowledge; Laboratories; Lipopolysaccharides; Lymphoid; Maintenance; Mediating; Mediator of activation protein; Microarray Analysis; Molecular; Mus; Myelogenous; Oncogenes; Oxidative Stress; Pathogenesis; Pathway interactions; Phenotype; Play; Polycomb; Pregnancy; Proto-Oncogene Protein c-kit; Regenerative Medicine; Reporter; Resistance; Retroviridae; Reverse Transcriptase Polymerase Chain Reaction; Role; Serum; Signal Transduction; Signaling Molecule; Sorting - Cell Movement; Stem cells; Stimulus; Stress; Tail; Testing; Time; Tissues; Trans-Activators; Transplantation; adult stem cell; base; cell type; cofactor; cytokine; genome-wide; hematopoietic tissue; histone acetyltransferase; in vivo; insight; leukemogenesis; member; mouse model; novel; overexpression; progenitor; public health relevance; reconstitution; research study; retroviral-mediated; stem cell biology; therapeutic development; transcription factor

DESCRIPTION (provided by applicant): Cited2 [CBP/p300-interacting transactivators with glutamic acid (E) and aspartic acid (D)-rich tail 2] is one of the founding members of a new family of transcriptional modulators. My laboratory cloned Cited2 and showed that Cited2 is induced by many cytokines and it is a transforming gene when overexpressed. We generated Cited2 null mice and found that deletion of Cited2 causes embryos to die at mid- to late gestation with several developmental defects. Since Cited2 expression correlates positively with LTR-HSCs activity and induces the expression of Bmi-1, a polycomb group gene necessary for the maintenance and renewal of embryonic and adult stem cells, we studied the role of Cited2 in fetal liver hematopoiesis. Cited2-/- fetal liver displayed significant reduction in the numbers of hematopoietic cells in different lineages. In vitro CFU and in vivo reconstitution studies demonstrate that Cited2 plays an important role in fetal liver hematopoiesis. Consistently, microarray analysis and real-time RT-PCR analyses identified several differentially expressed genes corresponding to HSC and progenitor dysfunction in Cited2-/- fetal liver. We have shown that Cited2 is a negative regulator of HIF-1 in certain tissues during development. More recently, others showed that FoxO3 is activated under hypoxia and inhibits HIF-1-induced apoptosis through Cited2 and decreased expression of Cited2 was found in FoxO triple knockout mice, establishing Cited2 as a downstream target of FoxO transcription factors. Since regional hypoxia in the bone marrow plays an important role in regulating stem cell function and FoxOs are critical mediators of HSC resistance to oxidative stress and maintenance of the HSC pool, we would like to study the crosstalk between Cited2, HIF-1, FoxOs and Bmi-1 in adult hematopoiesis using conditional knockout approach to test the hypothesis that the FoxO/Cited2/HIF-1 pathway and Bmi-1 play an important role in regulating HSC functions. The overall strategy of the application is to first functionally characterize Cited2 knockout phenotypes in adult hematopoietic tissue (Aim 1). This will be followed by two mechanistic studies to understand Cited2 actions. In addition to focusing on specific molecules such as Bmi-1 (Aim 2), FoxO3/HIF-1 (Aim 3) and their associated pathways, a more genome-wide approach will also be undertaken in parallel to uncover novel mechanisms. The proposed studies therefore will advance our knowledge of molecular mechanisms regulating normal and abnormal HSC biology, and thus may offer new insights into the therapeutic development targeting HSC for regenerative medicine and for treatment of different hematological malignancies. PUBLIC HEALTH RELEVANCE: This proposal will not only provide information critical to our understanding of normal hematopoiesis and stem cell biology but also elucidate the complex interplay between transcription factors/cofactors and signaling molecules in vivo, which may provide new clues to the molecular pathogenesis of leukemogenesis and help identify targets for specific therapies.

描述（由申请人提供）：引用2 [CBP/P300与谷氨酸（E）和天冬氨酸（D）-Rich Tail 2]的反式激活因素是新的转录调节剂家族的创始成员之一。我的实验室克隆引用了2，并表明引用2是由许多细胞因子诱导的，并且在过表达时是一个转化的基因。我们产生了引用的2个无效小鼠，发现删除引用2导致胚胎在妊娠中期至晚期死亡，并因几个发育缺陷而死亡。由于引用2的表达与LTR-HSC的活性正相关，并诱导BMI-1的表达，BMI-1是一种用于维持和更新胚胎和成人干细胞所必需的PolyComb基因基因，因此我们研究了CITED2在胎儿肝脏肝血肿中的作用。引用的2 - / - 胎儿肝显示出不同谱系中造血细胞数量的显着减少。体外CFU和体内重建研究表明，引用2在胎儿肝造血中起重要作用。一致地，微阵列分析和实时RT-PCR分析鉴定了与HSC和祖细胞功能障碍相对应的几个差异表达的基因。我们已经表明，在发育过程中，列出的2是某些组织中HIF-1的负调节剂。最近，其他人表明，在缺氧下激活了FOXO3，并通过引用2抑制HIF-1诱导的凋亡2，并且在Foxo三重基因敲除小鼠中发现了CUSID2的表达降低，并将引用2作为FOXO转录因子的下游靶标。由于骨髓中的区域缺氧在调节干细胞功能和FOXOS中起着重要作用，这是HSC抗氧化压力和HSC池维持的关键介体，因此我们想研究CITED2，HIF-1，HIF-1，HIF-1，FOXOS和BMI-1之间在成人瘤中使用fox-nockout-nif-nockout-inf-nif-hyfoth-cot/costosies的串扰。在调节HSC功能中的重要作用。该应用的总体策略是首先在功能上表征成人造血组织中引用的2基因敲除表型（AIM 1）。随后将进行两项机​​械研究，以了解引用的2个动作。除了关注BMI-1（AIM 2），FOXO3/HIF-1（AIM 3）及其相关途径等特定分子外，还将同时采用更全基因组的方法来揭示新的机制。因此，拟议的研究将提高我们对调节正常和异常HSC生物学的分子机制的了解，因此可能会为靶向HSC用于再生医学和治疗不同血液学恶性肿瘤的治疗发展提供新的见解。公共卫生相关性：该提案不仅将提供对我们对正常造血和干细胞生物学的理解至关重要的信息，而且还阐明了体内转录因子/辅助因子/辅助因子和信号分子之间的复杂相互作用，这可能为白血病生成的分子发病机理提供新的线索，并帮助识别特定特定特性的目标。