Role of Gas2 in cytoskeletal architecture, support cell stiffness, and cochlear function

Gas2 在细胞骨架结构、支持细胞刚度和耳蜗功能中的作用

• 批准号: 10630146
• 负责人: DOUGLAS J EPSTEIN
• 金额: $ 44.6万
• 依托单位: UNIVERSITY OF PENNSYLVANIA
• 依托单位国家: 美国
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-08-01 至 2024-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10630146
• 关键词: Acoustic Nerve; Actins; Adult; Affect; Age; Animal Model; Animals; Applications Grants; Architecture; Atomic Force Microscopy; Auditory; Brain; Cell surface; Cells; Cellular Morphology; Clinical; Cochlea; Cochlear duct; Complex; Coupled; Cytoskeleton; Data; Defect; Developed Countries; Embryo; Exhibits; Female; Fertility; Future; GAS2 gene; GJB2 gene; Gap Junctions; Gene Mutation; Genes; Genetic Predisposition to Disease; Growth; Hair Cells; Hearing; Human; Inherited; Inner Hair Cells; Knockout Mice; Labyrinth; Length; Mammals; Mechanics; Microtubule Bundle; Microtubule Stabilization; Microtubules; Modeling; Molecular; Mus; Neonatal; Nerve Fibers; Newborn Infant; Optical Coherence Tomography; Organ; Organ of Corti; Outer Hair Cells; Ovarian; Pathogenicity; Pathway interactions; Pattern; Perrault syndrome; Play; Plus End of the Microtubule; Proteins; Role; Sensorineural Hearing Loss; Sensory; Signal Transduction; Specificity; Supporting Cell; Symptoms; Tensile Strength; Testing; Tubulin; Viral; cell type; cochlear development; conditional knockout; design; early onset; experimental study; gene therapy; genetic regulatory protein; hearing impairment; hearing restoration; human model; inner ear development; inner ear diseases; insight; live cell imaging; mechanical force; mechanical properties; mouse model; neonatal mice; novel; postnatal; prevent hearing loss; protein crosslink; repaired; sound; transmission process; vibration

The identification of gene mutations associated with hearing loss in humans and animal models has contributed greatly to our understanding of cell type specific functions in the inner ear. Despite this progress, the cause of inherited forms of hearing loss still remains unknown in many cases, suggesting that the discovery of new genes associated with sensorineural hearing loss (SNHL) is far from saturated. To fill this gap, we performed a screen for novel regulators of cochlear development and identified several genes that are predicted to play important roles in cochlear function. We generated a mouse knockout for one of these genes, Growth arrest specific 2 (Gas2), encoding a putative cytoskeletal regulatory protein. Gas2 knockout mice display severe hearing loss with no alterations in inner ear development at embryonic stages. Instead, we propose that the cause of hearing loss is due to a progressive destabilization of the microtubule cytoskeleton in pillar and Deiters’ cells, two specialized support cells in the organ of Corti that are thought to provide tensile strength and a structural framework for transferring mechanical forces during sound-evoked vibrations. The experiments in this grant proposal are designed to transform our understanding of the role that support cells play in cochlear function. Firstly, we will test the hypothesis that Gas2 dependent stabilization of microtubule bundles in pillar and Deiters’ cells is required for hearing. Secondly, we will determine the influence of Gas2 and a-tubulin detyrosination on cell surface mechanical properties and microtubule dynamics. Finally, we will pursue the exciting possibility that viral delivery of Gas2 to support cells might prevent hearing loss when administered prior to the onset of symptoms in neonatal Gas2 knockout mice, and even more provocatively, might repair the cytoskeletal defects and restore hearing when administered to adults. Taken together, these experiments will clarify the proposed role of Gas2 as a microtubule and actin cross-linking protein that is required to stabilize microtubule bundles in cochlear support cells and that this activity is necessary for auditory function.

人类和动物模型中与听力损失相关的基因突变的鉴定 对我们理解内耳中细胞类型的特定功能有很大贡献。 尽管取得了这一进展，遗传性听力损失的原因仍然是未知的， 许多病例表明，与感觉神经性听力相关的新基因的发现， 而亏损（SNHL）远未饱和。为了填补这一空白，我们进行了一个新的监管机构的筛选， 耳蜗发育，并确定了几个基因，预计发挥重要作用， 耳蜗功能我们制造了一只敲除了其中一个基因的老鼠，生长停滞 特异性2（Gas 2），编码推定的细胞骨架调节蛋白。Gas 2基因敲除小鼠 在胚胎阶段表现出严重的听力损失，但内耳发育没有变化。 相反，我们认为听力损失的原因是由于听觉系统的渐进性不稳定。 柱细胞和Deiters细胞中的微管细胞骨架，柱细胞和Deiters细胞是器官中的两种专门支持细胞 Corti被认为提供了拉伸强度和结构框架， 声音诱发振动过程中的机械力。这项拨款申请中的实验是 旨在改变我们对支持细胞在耳蜗功能中所起作用的理解。 首先，我们将检验以下假设： pillar和Deiters细胞是听觉所必需的。其次，我们将确定 Gas 2和α-微管蛋白去酪氨酸对细胞表面力学性质和微管的影响 动力学最后，我们将追求令人兴奋的可能性，即病毒递送Gas 2以支持 在新生儿出现症状之前给予细胞可以预防听力损失。 Gas 2基因敲除小鼠，甚至更有可能修复细胞骨架缺陷， 给成年人服用时恢复听力。综合起来，这些实验将阐明 Gas 2作为微管和肌动蛋白交联蛋白的作用， 稳定耳蜗支持细胞中微管束，这种活性对于 听觉功能