Signals Regulating SAG Development

调节 SAG 发展的信号

• 批准号: 7731758
• 负责人: JAMES A MARRS
• 金额: $ 39.75万
• 依托单位: INDIANA UNIV-PURDUE UNIV AT INDIANAPOLIS
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-09-11 至 2011-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7731758
• 关键词: Acoustic Nerve; Adult; Affect; Arts; Auditory; Biological Assay; Cadherins; Cell Adhesion; Cell Polarity; Cell Survival; Cell Transplantation; Cells; Cephalic; Cues; Data; Development; Developmental Process; Differentiation and Growth; Embryo; Future; Ganglia; Genes; Genetic; Growth; Hair Cells; Image; Immunohistochemistry; Individual; Labyrinth; Maintenance; Molecular; Myxoid cyst; N-Cadherin; NIH Program Announcements; Names; National Institute on Deafness and Other Communication Disorders; Nerve; Neuronal Differentiation; Neurons; Nomenclature; Otic Vesicle; Pattern; Phenotype; Positioning Attribute; Process; Proteins; R-cadherin; Research; Role; Sensory Hair; Signal Pathway; Signal Transduction; Signaling Molecule; Structure; System; Time; Zebrafish; aging population; cadherin 10; cell behavior; cell motility; computerized data processing; hearing impairment; imaging modality; loss of function; migration; neuron loss; non-genetic; novel strategies; precursor cell; research study; residence; stem cell therapy; zebrafish development

DESCRIPTION (provided by applicant): Neuron loss, either dependent or independent of sensory hair cell loss, contributes significantly to hearing loss, particularly in the aging population. Future treatments, particularly stem cell therapies, will require detailed understanding of statoacoustic ganglion (SAG; VIIIth cranial nerve) developmental processes. We propose to analyze molecular and cellular mechanism of cadherin cell adhesion during zebrafish SAG development. SAG precursor cell behaviors will be studied using various assays, including advanced imaging methods to analyze proliferation, survival, maturation and SAG precursor cell movements from the otic vesicle to the forming ganglion. These experiments specifically fit the NIDCD Program Announcement PA-07-127. Overall hypothesis: the cadherin cell adhesion system responds to polarity cues and regulates morphogenetic cell movements during SAG development. Aim 1: Determine the expression pattern for cadherin-2, -4, -6 and -10 (cadherins expressed in the SAG) during normal and knockdown embryo SAG development. Cdh2, Cdh4 and Cdh6 knockdown experiments (nomenclature: gene names cdh2, cdh4, cdh6 and cdh10; and protein names Cdh2, Cdh4, Cdh6 and Cdh10) showed that these cadherins are required for SAG development. Cdh10 knockdown showed little or no SAG development phenotype, but this cadherin is expressed in a much smaller subset of SAG cells. We will examine spatial and temporal expression patterns for cadherin-2, -4, -6 and -10. We hypothesize that cadherin expression regulates SAG precursor cell movements, precursor cell survival and neuronal differentiation during inner ear development. Individual cadherin expression patterns will also be examined in Cdh2, 4, 6 and 10 knockdown embryos to determine whether there is compensatory cadherin expression. Aim 2: Determine cadherin signaling effects on SAG development. We hypothesize that cadherin activity regulates specific cellular phenotype (differentiation, growth, survival and migration) during SAG development. Signaling mechanisms will be compared using assays for otic specification, proliferation and survival. In addition, we propose to evaluate SAG precursor cell behaviors using state-of-the-art time-lapse imaging. Normal SAG development will be compared with cadherin loss-of-function phenotypes. In addition, cell polarity signaling molecule functions during SAG development will be studied. Aim 3. Determine whether specific cadherin activity that regulates SAG cell development is cell autonomous or non-cell autonomous. We hypothesize that cadherin activity can regulate different cellular phenotypes (e.g., differentiation, growth, survival and migration) cell autonomously and other cellular phenotypes cell-non autonomously during SAG development. Cell transplantation, genetic mosaic experiments will be performed to determine whether the molecular and cellular mechanisms that were identified act cell autonomously or cell-non autonomously. Nerve cell loss contributes to hearing loss, particularly in the aging population. Future treatments for hearing loss, especially the promise of stem cell therapies, will require detailed understanding of nerve development, including growth and maintenance of the auditory nerve. We propose a novel approach to the study of this process, which fits NIDCD Program Announcement PA-07-127.

描述（由申请人提供）：神经元损失，无论是依赖于或独立于感觉毛细胞损失，都是听力损失的重要原因，特别是在老年人群中。未来的治疗，特别是干细胞疗法，将需要详细了解的平衡听神经节（SAG;第八颅神经）的发育过程。我们拟从分子和细胞两方面分析钙粘蛋白在斑马鱼SAG发育过程中的作用机制。SAG前体细胞行为将使用各种测定法进行研究，包括先进的成像方法，以分析增殖，存活，成熟和SAG前体细胞从耳囊到形成神经节的运动。这些实验特别符合NIDCD计划公告PA-07-127。总体假设：在SAG的发展过程中，钙粘蛋白细胞粘附系统响应极性线索并调节形态发生细胞的运动。目标1：确定正常和敲低胚胎SAG发育过程中钙粘蛋白-2、-4、-6和-10（SAG中表达的钙粘蛋白）的表达模式。Cdh 2、Cdh 4和Cdh 6敲低实验（命名：基因名称Cdh 2、Cdh 4、Cdh 6和Cdh 10;蛋白质名称Cdh 2、Cdh 4、Cdh 6和Cdh 10）表明，这些钙粘蛋白是SAG发育所需的。Cdh 10敲除显示很少或没有SAG发育表型，但这种钙粘蛋白在小得多的SAG细胞亚群中表达。我们将检查钙粘蛋白-2、-4、-6和-10的空间和时间表达模式。我们推测，在内耳发育过程中，钙粘蛋白的表达调节SAG前体细胞的运动，前体细胞的存活和神经元的分化。还将在Cdh 2、4、6和10敲低胚胎中检查个体钙粘蛋白表达模式，以确定是否存在代偿性钙粘蛋白表达。目的2：确定钙粘蛋白信号转导在SAG发生中的作用。我们假设钙粘蛋白活性调节特定的细胞表型（分化，生长，存活和迁移）在SAG的发展。将使用耳特异性、增殖和存活的测定来比较信号传导机制。此外，我们建议使用最先进的延时成像来评估SAG前体细胞的行为。将正常SAG发展与钙粘蛋白功能丧失表型进行比较。此外，细胞极性信号分子在SAG发展过程中的功能也将被研究。目标3。确定调节SAG细胞发育的特异性钙粘蛋白活性是细胞自主的还是非细胞自主的。我们假设钙粘蛋白活性可以调节不同的细胞表型（例如，分化、生长、存活和迁移）细胞自主和其他细胞表型细胞非自主。将进行细胞移植、遗传镶嵌实验以确定所鉴定的分子和细胞机制是细胞自主还是细胞非自主地起作用。神经细胞的丧失会导致听力损失，特别是在老年人中。未来的听力损失治疗，特别是干细胞疗法的前景，将需要详细了解神经发育，包括听神经的生长和维持。我们提出了一种新的方法来研究这个过程，这适合NIDCD计划公告PA-07-127。