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）：本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相互作用控制细胞命运规范、细胞增殖和分化的机制。这项研究将使用果蝇作为模型系统，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的功能高度保守，并且因为在果蝇系统中结合生化，遗传，细胞和发育方法进行体内研究很容易。在果蝇视网膜发育过程中，视网膜前基因Atonal （ato）的表达对于视网膜前细胞启动神经元分化至关重要。Ato的表达最初由Ato 3‘增强子上调，并由Ato 5’增强子完善。解剖Ato 3'增强子发现Ato直接受到视网膜决定（RD）网络蛋白Eyeless （Ey）、Eyes absent （Eya）和Sine oculis （So）的调控。我们的初步研究表明，Ato 3'增强子也受bHLH蛋白的正向和负向调控。在形态发生沟（MF）后，Notch信号通过抑制Ato表达负向调节光受体分化，同时促进第二有丝分裂波（SMW）中的S期。我们发现Da在SMW的S期也是必需的，并且Da和Notch信号都通过CycEdisc增强子调节SMW中的CycE表达。根据我们的初步结果，我们假设不同的bHLH二聚体参与了Ato 3'增强子的激活或抑制，这是基于它们与RD蛋白的相互作用。基于与Notch信号的相互作用，类似的特异性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因子的功能和调控提供了一个很好的体内系统。为了验证这些假设，并利用果蝇系统来表征RD网络蛋白，我们有三个具体目标：1。描述Da调控Ato 3'增强子的机制。2. 利用果蝇模型表征Ey/Pax6的功能和调控。3. 确定Da和Notch信号协调控制SMW细胞增殖和光受体分化的机制。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视网膜疾病以及其他涉及细胞增殖或分化缺陷的人类疾病的预防、诊断和治疗的新方法的最终发展至关重要。