Stepwise Coordination of Eye Morphogenesis by Extracellular Matrix

细胞外基质对眼睛形态发生的逐步协调

• 批准号: 8945899
• 负责人: Kristen M Kwan
• 金额: $ 29.8万
• 依托单位: UNIVERSITY OF UTAH
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-09-01 至 2019-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8945899
• 关键词: Accounting; Actins; Adhesions; Animal Model; Anterior; Biological Models; Cell Death; Cell Polarity; Cell Survival; Cell physiology; Cells; Choroid; Collagen; Collagen Type IV; Coloboma; Complex; Computational Technique; Computing Methodologies; Defect; Development; Ectoderm; Embryo; Event; Extracellular Matrix; Eye; Eye Development; Failure; Four-dimensional; Fresh Water; Glycoproteins; Goals; Hereditary nephritis; Human; Image; Image Analysis; Imaging Techniques; Irido-corneo-trabecular dysgenesis; Laminin; Lead; Lens Placodes; Life; Microscopy; Molecular; Molecular Genetics; Morphogenesis; Movement; Mutate; Mutation; Neural Retina; Newborn Infant; Nidogen; Ocular Pathology; Optic vesicle; Optics; Pathway interactions; Play; Positioning Attribute; Process; Retina; Role; Series; Shapes; Signal Transduction; Structural defect; Structure; Structure of retinal pigment epithelium; Testing; Tissues; Vertebrates; Visual impairment; Zebrafish; base; cell behavior; cell motility; constriction; crosslink; eye formation; imaging modality; in vivo; innovation; lens; molecular dynamics; mutant; novel; optic cup; prospective; public health relevance; quantitative imaging; research study; teleost fish

 DESCRIPTION (provided by applicant): Developmental defects in eye structure commonly account for visual impairment in newborns. Proper eye structure is initially established during the process of optic cup morphogenesis, during which the optic vesicle transforms into the optic cup via a series of complex cell and tissue rearrangements, with neural retina and retinal pigmented epithelium surrounding the newly formed lens. Recent advances in live imaging have begun to reveal the cellular processes underlying optic cup morphogenesis, yet molecular control of these critical events still remains largely unknown. A compelling candidate to play a role in controlling optic cup morphogenesis is the extracellular matrix (ECM), a complex, glycoprotein-rich layer that can regulate cell survival, movement, polarity, and tissue tension. ECM components, including laminin and type IV collagens, surround eye structures throughout optic cup morphogenesis in all vertebrates examined to date. Mutations in certain ECM components can lead to specific ocular pathologies in humans and model organisms, such as coloboma (failure of choroid fissure development) or lens defects. This suggests distinct requirements for ECM components during specific events in optic cup morphogenesis, yet this has not been examined in a systematic way. Zebrafish presents an ideal model system to study this process: optical transparency and rapid development offer a unique opportunity to directly watch eye formation in vivo. Further, we previously developed 4-dimensional imaging and computational techniques to track and visualize cell movements and behaviors throughout optic cup morphogenesis. This puts us in a unique position to quantitatively determine specific morphogenetic defects arising when particular matrix components are disrupted. In this proposal, we will determine the roles of laminin, type IV collagens, and the laminin-collagen cross-linking molecule nidogen during optic cup morphogenesis. I hypothesize that sequential steps of optic cup morphogenesis harbor distinct requirements for matrix components and higher-order assembly, and that these differential requirements underlie specific ocular pathologies seen in humans and model organisms. Combining molecular genetics with innovative 4-dimensional live imaging and computational methods, we will test this hypothesis in the following specific aims: (1) determine the role of matrix components and supramolecular assembly in choroid fissure formation; (2) determine how matrix components control optic cup invagination, taking advantage of a novel mutant, in which retina-lens de-adhesion (and possibly collagen signaling) are impaired; (3) determine the role of matrix components in establishing proper lens shape and ectoderm separation. The experiments proposed here will define the cellular and molecular dynamics of extracellular matrix adhesion underlying critical steps in optic cup morphogenesis, and the specific cellular functions executed by matrix during each step.

 描述(申请人提供)：眼睛结构的发育缺陷通常是新生儿视力受损的原因。在视杯形态发生的过程中，视泡通过一系列复杂的细胞和组织重排转化为视杯，神经视网膜和视网膜色素上皮包围着新形成的晶状体。活体成像的最新进展已经开始揭示视杯形态发生的细胞过程，然而这些关键事件的分子控制在很大程度上仍然是未知的。细胞外基质(ECM)是一种复杂的富含糖蛋白的层，可以调节细胞的存活、运动、极性和组织张力，是控制视杯形态发生的一个引人注目的候选组织。细胞外基质成分，包括层粘连蛋白和IV型胶原蛋白，在所有被检查的脊椎动物的视杯形态发生过程中包围着眼睛结构。某些细胞外基质成分的突变可能导致人类和模式生物的特定眼部病理，如缺损(脉络膜裂隙发育失败)或晶状体缺陷。这表明在视杯形态发生的特定事件中对细胞外基质成分有不同的要求，但这还没有被系统地检验。斑马鱼为研究这一过程提供了一个理想的模型系统：光学透明度和快速发展为直接观察活体中的眼睛形成提供了独特的机会。此外，我们之前开发了4维成像和计算技术来跟踪和可视化细胞在视杯形态发生过程中的运动和行为。这使我们处于一个独特的位置，可以定量地确定当特定的基质成分被破坏时产生的特定的形态发生缺陷。在这项研究中，我们将确定层粘连蛋白、IV型胶原和层粘连蛋白-胶原交联分子Nidgen在视杯形态发生中的作用。我假设视杯形态发生的连续步骤对基质成分和高阶组装有不同的要求，这些不同的要求是在人类和模式生物中看到的特定眼部病理的基础。结合分子遗传学与创新的4维实时成像和计算方法，我们将在以下特定目标下检验这一假说：(1)确定基质成分和超分子组装在脉络膜裂隙形成中的作用；(2)确定基质成分如何控制视杯内陷，利用一个新的突变体，其中视网膜-晶状体去黏附(和可能的胶原信号)受损；(3)确定基质成分在建立正确的晶状体形状和外胚层分离中的作用。这里提出的实验将定义细胞外基质黏附的细胞和分子动力学，这些黏附是光学中关键步骤的基础。 杯状细胞的形态发生，以及在每个步骤中由基质执行的特定细胞功能。