Control of Cell Proliferation and Differentiation in the Developing Retina

视网膜发育中细胞增殖和分化的控制

• 批准号: 8113313
• 负责人: WEI DU
• 金额: $ 30.46万
• 依托单位: UNIVERSITY OF CHICAGO
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-02-01 至 2014-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8113313
• 关键词: Binding Sites; Biochemical Genetics; Biological Models; Boxing; Cell Culture System; Cell Differentiation process; Cell Proliferation; Cells; Complex; Defect; Development; Diagnosis; Dissection; Down-Regulation; Drosophila genus; Enhancers; Eye; Genes; Grant; Investigation; Knowledge; Link; Mitotic; Modeling; Neuronal Differentiation; Pathway interactions; Phosphorylation; Photoreceptors; Prevention; Proteins; RNA Splicing; Regulation; Research; Retina; Retinal; Retinal Diseases; Role; S Phase; Signal Pathway; Signal Transduction; Site; System; Testing; base; cell fate specification; dimer; fly; gene conservation; homeodomain; human disease; in vivo; insight; notch protein; novel strategies; public health relevance; retinal progenitor cell; transcription factor

DESCRIPTION (provided by applicant): The long term objective of this grant is to elucidate the mechanisms by which cell intrinsic transcription factors and developmental signaling pathways interact in the control of cell fate specification, cell proliferation, and differentiation during retinal development. This investigation will be carried out using Drosophila as a model system because of the high functional conservations of the genes and pathways controlling retinal development between the Drosophila and the mammalian systems and because of the ease of combining biochemical, genetic, cellular, and developmental approaches in the fly system to carry out in vivo studies. During Drosophila retinal development, expression of the proneural gene Atonal (ato) is critical for retinal progenitor cells to initiate neuronal differentiation. Ato expression is initially upregulated by the Ato 3' enhancer and is refined by the Ato 5' enhancer. Dissection of the Ato 3' enhancer revealed that Ato is directly regulated by retinal determination (RD) network proteins Eyeless (Ey), Eyes absent (Eya), and Sine oculis (So). Our preliminary studies revealed that Ato 3' enhancer is also regulated by bHLH proteins both positively and negatively. Posterior to the morphogenetic furrow (MF), Notch signaling negatively regulates photoreceptor differentiation by inhibiting Ato expression and simultaneously promotes S phase in the second mitotic wave (SMW). We show that Da is also required for S phase in the SMW and that both Da and Notch signaling regulate CycE expression in the SMW through the CycEdisc enhancer. We hypothesize based on our preliminary results that different bHLH dimers are involved in the activation or inhibition of the Ato 3' enhancer based on their interactions with the RD proteins. Similarly specific Da dimers are also involved in the activation of the CycEdisc enhancer in the SMW based on their interactions with the Notch signaling. In addition, the activation of Ato 3' enhancer also provides a nice in vivo system to investigate the function and regulation of RD factors. To test these hypotheses and to use the Drosophila system to characterize the RD network proteins, we have three Specific Aims: 1. Characterize the mechanisms by which Da regulates Ato 3' enhancer. 2. Characterize the function and regulation of Ey/Pax6 using the Drosophila model. 3. Determine the mechanisms by which Da and Notch signaling coordinate the control of cell proliferation and photoreceptor differentiation in the SMW. Knowledge obtained from this study in Drosophila can be applied to the mammalian systems and will provide new mechanistic insights into the control of cell proliferation and differentiation during normal retinal development. Understanding the control of normal retinal development is critical for the eventual development of new approaches for the prevention, diagnosis, and treatment of retinal diseases as well as other human diseases involving cell proliferation or differentiation defect. PUBLIC HEALTH RELEVANCE: This research will provide new mechanistic insights into the control of cell fate specification, cell proliferation and differentiation during normal retinal development. Understanding the control of normal retinal development is critical for the eventual development of new approaches for the prevention, diagnosis, and treatment of retinal diseases.

描述（由申请人提供）：该资助的长期目标是阐明细胞内在转录因子和发育信号通路在视网膜发育过程中细胞命运规范、细胞增殖和分化的控制中相互作用的机制。这项研究将使用果蝇作为模型系统进行，因为果蝇和哺乳动物系统之间控制视网膜发育的基因和途径具有高度功能保守性，并且因为在生物化学、遗传、细胞和发育方法中很容易结合起来果蝇系统进行体内研究。在果蝇视网膜发育过程中，原神经基因 Atonal (ato) 的表达对于视网膜祖细胞启动神经元分化至关重要。 Ato 表达最初由 Ato 3' 增强子上调，并由 Ato 5' 增强子细化。对 Ato 3' 增强子的解剖表明，Ato 直接受视网膜决定 (RD) 网络蛋白 Eyeless (Ey)、Eyes Absent (Eya) 和 Sine oculus (So) 的调节。我们的初步研究表明，Ato 3' 增强子也受到 bHLH 蛋白的正向和负向调节。在形态发生沟 (MF) 后面，Notch 信号通过抑制 Ato 表达来负向调节光感受器分化，同时促进第二有丝分裂波 (SMW) 中的 S 期。我们发现 Da 也是 SMW 中 S 期所必需的，并且 Da 和 Notch 信号传导均通过 CycEdisc 增强子调节 SMW 中 CycE 的表达。根据我们的初步结果，我们假设不同的 bHLH 二聚体根据它们与 RD 蛋白的相互作用参与 Ato 3' 增强子的激活或抑制。类似地，基于与 Notch 信号传导的相互作用，特定的 Da 二聚体也参与 SMW 中 CycEdisc 增强子的激活。此外，Ato 3'增强子的激活也为研究RD因子的功能和调节提供了良好的体内系统。为了测试这些假设并使用果蝇系统来表征 RD 网络蛋白，我们有三个具体目标： 1. 表征 Da 调节 Ato 3' 增强子的机制。 2. 使用果蝇模型表征 Ey/Pax6 的功能和调节。 3. 确定 Da 和 Notch 信号传导协调 SMW 中细胞增殖和光感受器分化控制的机制。从果蝇研究中获得的知识可以应用于哺乳动物系统，并将为正常视网膜发育过程中细胞增殖和分化的控制提供新的机制见解。了解正常视网膜发育的控制对于最终开发预防、诊断和治疗视网膜疾病以及涉及细胞增殖或分化缺陷的其他人类疾病的新方法至关重要。 公共健康相关性：这项研究将为正常视网膜发育过程中细胞命运规范、细胞增殖和分化的控制提供新的机制见解。了解正常视网膜发育的控制对于最终开发预防、诊断和治疗视网膜疾病的新方法至关重要。