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: 9816749
• 负责人: DOUGLAS J EPSTEIN
• 金额: $ 47.77万
• 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/9816749
• 关键词: Acoustic Nerve; Actins; Address; 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; Developing Countries; Development; 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; Structure; Supporting Cell; Symptoms; Tensile Strength; Testing; Viral; alpha Tubulin; base; cell type; crosslink; design; early onset; experimental study; gene therapy; genetic regulatory protein; hearing impairment; hearing restoration; human model; inner ear development; inner ear diseases; insight; link protein; live cell imaging; mechanical force; mechanical properties; mouse model; novel; postnatal; prevent hearing loss; repaired; sound; 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 对我们了解内耳细胞类型的特殊功能有很大的贡献。 尽管取得了这些进展，但遗传性听力损失的原因仍不清楚。 许多情况下，表明与感觉神经性听力有关的新基因的发现 亏损(SNHL)还远未饱和。为了填补这一空白，我们对新的调节器进行了筛选 并确定了几个被预测在耳蜗发育中发挥重要作用的基因 耳蜗机能。我们对其中一个基因--生长停滞--进行了小鼠基因敲除 特异性2(Gas2)，编码一个假定的细胞骨架调节蛋白。Gas2基因敲除小鼠 在胚胎阶段表现出严重的听力损失，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力的渐进性不稳定。 柱状细胞和Deiters细胞中的微管细胞骨架 被认为提供抗拉强度和用于转移的结构框架的Corti 声音诱发振动过程中的机械力。这项拨款提案中的实验是 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Gas2依赖于微管束的稳定性的假设 需要佩雷尔和戴特斯的牢房才能听到。其次，我们将确定 Gas2和α-微管蛋白降解对细胞表面力学性质和微管的影响 动力学。最后，我们将探索Gas2病毒传播支持的令人兴奋的可能性 如果在新生儿出现症状之前给药，细胞可以防止听力损失 Gas2基因敲除小鼠，甚至更具挑衅性的，可能修复细胞骨架缺陷和 给成年人用药后，恢复听力。总而言之，这些实验将澄清 Gas2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的微管束，这一活动是 听觉功能。