Role of Cited2 in Lung Development

Cited2 在肺部发育中的作用

• 批准号: 7539211
• 负责人: YU-CHUNG YANG
• 金额: $ 23.18万
• 依托单位: CASE WESTERN RESERVE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-12-10 至 2010-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7539211
• 关键词: A549; Alveolar; Alveolar Cell; Antibodies; Apoptosis; Apoptotic; Binding; Biological; Biological Assay; CCAAT-Enhancer-Binding Proteins; Cell Differentiation process; Cell Survival; Cells; Competitive Binding; Complex; Cysteine; D-Aspartic Acid; DNA-Binding Proteins; Defect; Development; Differentiation Antigens; EP300 gene; Electrophoretic Mobility Shift Assay; Elements; Embryo; Epithelial; Family; Figs - dietary; Gene Dosage; Gene Targeting; Genes; Genetic; Genetic Transcription; Glutamic Acid; Goals; Hela Cells; Histidine; Histology; Histone Acetylation; Histones; Hypoxia; Laboratories; Lipopolysaccharides; Luciferases; Lung; Mediating; Messenger RNA; Molecular; Mus; Oncogenes; Pathogenesis; Peroxisome Proliferator-Activated Receptors; Phenotype; Pregnancy; Proteins; Reporter; Reverse Transcriptase Polymerase Chain Reaction; Role; Serum; Signal Transduction; Small Interfering RNA; Stimulus; Tail; Testing; Time; Trans-Activators; Transcription Coactivator; Transcription Repressor/Corepressor; Transcriptional Activation; Transfection; Western Blotting; cell type; chromatin immunoprecipitation; chromatin remodeling; cytokine; in vivo; knock-down; lung development; lung maturation; member; overexpression; promoter; research study; respiratory distress syndrome; shear stress

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 activators. My laboratory cloned Cited2 and showed that Cited2 is induced by many biological stimuli such as cytokines, serum and lipopolysaccharide (LPS) in different cell types and it is a transforming gene when overexpressed. Cited2 acts as a transcriptional modulator by interacting with DNA binding proteins (Tfap2, Smad2/3, Lhx2, PPAR, and PPAR) to regulate the transcription of their corresponding target genes. It also functions as a negative regulator of HIF-1 by competing with HIF-1 in binding to the first cysteine-histidine-rich (CH1) region of CBP/p300 to inhibit HIF-1 mediated signaling. Mice lacking Cited2 die at late gestation with numerous developmental defects. Recently, we observed pulmonary immaturity in E17.5 to E18.5 Cited2-/- lungs, which display significantly reduced alveolar space due to an arrest in the type I and type II alveolar cell differentiation and decreased number of apoptotic alveolar cells. Consistent with the phenotype, genes associated with alveolar cell differentiation were differentially expressed between wild-type and Cited2-/- embryonic lungs. These results suggest that Cited2 may be a potential candidate for respiratory distress syndrome. We further demonstrated that expression of C/EBP, one of the key regulators of airway epithelial maturation, was significantly decreased in Cited2-/- embryonic lungs. Interestingly, many of the phenotypes in Cited2-null embryonic lungs were similar to those in mice bearing lung-specific deletion of C/EBP and deletion in the CH1 domain of CBP. In transient transfection assays, Tfap2c functioned as a transcriptional repressor of the C/EBP gene promoter in HeLa and A549 cells and this repressive effect was abolished by co-transfection of Cited2. Thus, we hypothesize that Cited2-Tfap2c-CBP complex controls lung maturation by regulating C/EBP expression. To test this hypothesis, we will (1) study the regulatory mechanism of Cited2 on C/EBP expression, (2) use genetic approaches to show that C/EBP is responsible for the pulmonary immaturity in Cited2- deficient embryonic lung during development, and (3) study the molecular mechanism of alveolar cell survival and differentiation arrest in Cited2-deficient embryonic lung. The accomplishment of the study will not only elucidate molecular mechanisms of lung development but also provide new clues to the molecular pathogenesis of respiratory distress syndrome 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]的反式激活剂是新的转录激活剂家族的创始成员之一。我的实验室克隆引用了2，并表明引用的2是由许多生物刺激（例如不同细胞类型的细胞因子，血清和脂多糖）（LPS）诱导的，当过表达时，它是转化的基因。引用2通过与DNA结合蛋白（TFAP2，SMAD2/3，LHX2，PPAR和PPAR）相互作用来充当转录调节剂。它还通过与HIF-1竞争与CBP/p300的第一个富含半胱氨酸 - 抗二碱的区域结合以抑制HIF-1介导的信号传导来充当HIF-1的负调节剂。缺乏引用的2岁的小鼠在妊娠晚期死亡，并且存在许多发育缺陷。最近，我们观察到E17.5至E18.5引用的2 - / - 肺中的肺动脉不成熟，由于I型和II型肺泡细胞分化和凋亡肺泡细胞的数量减少，它们显示出显着降低肺泡空间。与表型一致，与牙槽细胞分化相关的基因在野生型和引用2 - / - 胚胎肺之间差异表达。这些结果表明，引用2可能是呼吸窘迫综合征的潜在候选者。我们进一步证明，C/EBP的表达是气道上皮成熟的关键调节剂之一，在引用2 - / - 胚胎肺中显着降低。有趣的是，引用的2-无胚胎肺中的许多表型与CBP CH1结构域中的C/EBP和缺失的小鼠中的许多表型相似。在瞬时转染测定中，TFAP2C充当HELA和A549细胞中C/EBP基因启动子的转录抑制剂，并通过共转染引用2消除了这种抑制作用2。因此，我们假设引用2-TFAP2C-CBP复合物通过调节C/EBP表达来控制肺的成熟。 To test this hypothesis, we will (1) study the regulatory mechanism of Cited2 on C/EBP expression, (2) use genetic approaches to show that C/EBP is responsible for the pulmonary immaturity in Cited2- deficient embryonic lung during development, and (3) study the molecular mechanism of alveolar cell survival and differentiation arrest in Cited2-deficient embryonic lung.该研究的完成不仅将阐明肺发育的分子机制，而且还为呼吸窘迫综合征的分子发病机理提供了新的线索，并有助于识别特定疗法的靶标。