Probing how hair bundle mechanical properties shape the mechanotransducer receptor current

探讨发束机械特性如何塑造机械传感器受体电流

• 批准号: 10778103
• 负责人: Anthony J Ricci
• 金额: $ 66.42万
• 依托单位: STANFORD UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-09-18 至 2028-08-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10778103
• 关键词: ATP phosphohydrolase; Acoustic Stimulation; Actins; Address; Age; Aging; Animals; Auditory; Biophysics; Brain; Buffers; Calcium; Cells; Characteristics; Cochlea; Coupled; Data; Data Set; Endolymph; Foundations; Frequencies; Generations; Genetic Diseases; Goals; Hair; Hair Cells; Image; Individual; Inner Hair Cells; Intervention; Investigation; Ion Channel Gating; Kinetics; Labyrinth; Link; Liquid substance; Location; Mechanical Stimulation; Mechanics; Modeling; Molecular; Monitor; Morphology; Motion; Motor; Mus; Noise; Organ; Organ Model; Organelles; Outer Hair Cells; Phosphatidylinositol 4,5-Diphosphate; Physiological; Positioning Attribute; Predisposition; Prevention therapy; Process; Property; Protocols documentation; Rana; Rattus; Receptor Cell; Reporting; Role; Rotation; Saccule structure; Sensory; Sensory Hair; Shapes; Signal Pathway; Signal Transduction; Site; Speed; Stereocilium; Stimulus; Technology; Testing; Translating; Turtles; Usher Syndrome; Work; antagonist; biophysical properties; cell type; channel blockers; experimental study; genetic manipulation; insight; mechanical properties; receptor; response; restoration; synergism; tectorial membrane; theories; therapy design; tongue papilla; voltage; ATP phosphohydrolase; Acoustic Stimulation; Actins; Address; Age; Aging; Animals; Auditory; Biophysics; Brain; Buffers; Calcium; Cells; Characteristics; Cochlea; Coupled; Data; Data Set; Endolymph; Foundations; Frequencies; Generations; Genetic Diseases; Goals; Hair; Hair Cells; Image; Individual; Inner Hair Cells; Intervention; Investigation; Ion Channel Gating; Kinetics; Labyrinth; Link; Liquid substance; Location; Mechanical Stimulation; Mechanics; Modeling; Molecular; Monitor; Morphology; Motion; Motor; Mus; Noise; Organ; Organ Model; Organelles; Outer Hair Cells; Phosphatidylinositol 4,5-Diphosphate; Physiological; Positioning Attribute; Predisposition; Prevention therapy; Process; Property; Protocols documentation; Rana; Rattus; Receptor Cell; Reporting; Role; Rotation; Saccule structure; Sensory; Sensory Hair; Shapes; Signal Pathway; Signal Transduction; Site; Speed; Stereocilium; Stimulus; Technology; Testing; Translating; Turtles; Usher Syndrome; Work; antagonist; biophysical properties; cell type; channel blockers; experimental study; genetic manipulation; insight; mechanical properties; receptor; response; restoration; synergism; tectorial membrane; theories; therapy design; tongue papilla; voltage

Abstract: Auditory and vestibular sensory cells use the hair bundle, a stair-cased array of actin filled stereocilia, to translate mechanical motion into an electrical signal. Mechanically-gated (MET) ion channels located at the tips of shorter stereocilia are activated by force created by the pulling of a tip link that extends between stereocilia. As sensory hair bundles are a major site for both genetic disorders like Ushers syndrome and are also susceptible to damage from noise and aging, understanding how these bundles operate is critical to designing therapies for prevention and restoration of function. Mammalian cochlear hair bundles have unusual morphologies and interstereocilia connectivity that is not as tight as other inner ear end organs. There is considerable debate as to the mechanisms underlying processes impacting MET currents and hair bundle mechanics, like fast and slow adaptation, gating compliance and voltage driven responses. There is further controversy over whether we truly have causal links between MET current responses and mechanical, molecular mechanisms. Before being able to use the power of genetic manipulation of newly identified MET molecules, we need a clear understanding of hair bundle biophysical properties and how they impact MET receptor currents. We hypothesize that the lack of connectivity in bundle motion is to optimize the hair bundle's response to natural stimulation and that synchronization of stereocilia comes from the tectorial membrane (OHCs) or the fluid stimulation (IHCs). We further hypothesize that we will identify mechanical correlates for fast and slow adaptation as well as gating compliance; however, we do expect there to be less slow adaptation as compared to other hair cell types but also that the mechanism of slow adaptation will not align with classical theories. And finally. we hypothesize that MET channel properties work with hair bundle mechanics to create tuning of the receptor current. We will investigate each of these hypotheses in the following specific aims. SA1 will generate a comprehensive data set of MET channel and hair bundle properties at multiple frequency positions from rats and mice P10-12 of age. By taking advantage of three modes of stimulations, wide probe, fluid jet and the newly developed narrow probe, we can separate between MET channel and hair bundle properties. SA2 will directly address hair bundle mechanics and known hair bundle properties using the newly developed high-speed imaging with either narrow probe or fluid jet technology. Experiments will target MET channel gating compliance, fast and slow adaptation and voltage dependent mechanical hair bundle responses. SA3 will generate frequency response curves under physiological conditions using the wide probe and fluid jet to define the filtering properties of the channel and the hair bundle. Completion of these aims will provide an unprecedented level of quantitative information as to how the hair bundle moves and how this motion shapes the MET receptor current generated. They will be the standard by which molecular manipulations can be assessed.

摘要：听觉和前庭感觉细胞使用头发束，这是act楼的肌动蛋白阵列 立体胶质，将机械运动转化为电信号。机械门控（Met）离子通道 位于较短的立体尾尖的尖端，通过拉伸链接延伸的尖端链接产生的力激活 在立体膜之间。由于感觉束是两个遗传疾病（例如Ushers综合征）的主要部位 并且也容易受到噪音和衰老的损害，了解这些捆绑包的工作方式至关重要 设计用于预防和恢复功能的疗法。哺乳动物的耳蜗头发束不寻常 形态和肠层连通性不如其他内耳末端器官紧密。有 关于影响MET电流和发束的机制的辩论很大 机械师，例如快速和缓慢的适应性，门控依从性和电压驱动的响应。还有更多 关于我们是否真正在MET电流响应与机械，分子之间存在因果关系的争议 机制。在能够利用新鉴定的MET分子的基因操纵的力量之前，我们 需要清楚地了解头发束生物物理特性及其如何影响MET受体电流。 我们假设捆绑运动中缺乏连通性是为了优化头发对天然的反应 刺激和立体胶质的同步来自tecorial膜（OHC）或流体 刺激（IHC）。我们进一步假设我们将确定快速和缓慢适应的机械相关性 以及门控的合规性；但是，我们确实希望与其他头发相比，适应性较慢 细胞类型，但缓慢适应的机制也与经典理论不符。最后。我们 假设MET通道属性与发束机械师一起起作用以创建受体调整 当前的。我们将在以下特定目标中调查这些假设中的每一个。 SA1将产生一个 大鼠的多个频率位置的MET通道和发束性能的全面数据集 小鼠年龄P10-12。通过利用三种刺激模式，宽探头，流体射流和新的刺激模式 开发了狭窄的探针，我们可以在MET通道和发束性质之间分开。 SA2将直接 使用新开发的高速成像来解决头发束机制和已知的头发捆 使用狭窄的探针或流体喷气技术。实验将靶向MET MET Channel Gating Comporiance，快速，并且 缓慢的适应性和依赖电压的机械头发束反应。 SA3将产生频率 使用宽探针和流体射流在生理条件下的反应曲线来定义过滤特性 频道和发束。这些目标的完成将提供空前的定量水平 有关头发如何移动以及该运动如何塑造MET受体电流的信息。 它们将是可以评估分子操作的标准。