Supplement for Mechanotransduction-Dependent Remodeling of the Stereocilia Cytoskeleton

立体纤毛细胞骨架的机械传导依赖性重塑的补充

• 批准号: 10170923
• 负责人: Alejandra Catalina Velez Ortega
• 金额: $ 7.41万
• 依托单位: UNIVERSITY OF KENTUCKY
• 依托单位国家: 美国
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-07-01 至 2021-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10170923
• 关键词: 3-Dimensional; Actins; Address; Administrative Supplement; Affect; Antibodies; Architecture; Area; Auditory; Automobile Driving; Buffers; Calcium; Cells; Childbirth; Cilia; Cochlea; Cytoskeleton; Data Analyses; Data Set; Exhibits; Goals; Growth; Hair; Hair Cells; Hearing; Height; Human Resources; Image; Ions; Label; Labyrinth; Lead; Link; Maintenance; Manuscripts; Measurement; Molecular; Morphology; Motor; Mus; Mutant Strains Mice; Mutation; Myosin ATPase; Natural regeneration; Noise-Induced Hearing Loss; Outer Hair Cells; Plasmids; Preparation; Protein Isoforms; Proteins; Regulation; Resources; Rest; Role; Scanning Electron Microscopy; Sensory; Sensory Hair; Shapes; Testing; Time; Variant; age related; base; beta Actin; depolymerization; experimental study; falls; gamma Actin; hearing impairment; mechanotransduction; microscopic imaging; mutant; new therapeutic target; parent grant; polymerization; prevent; response; treadmill

PROJECT SUMMARY/ABSTRACT Stereocilia are the sensory machinery of the inner ear sensory hair cells. We found that the stability of these actin-filled projections depends on the constant influx of calcium through the mechano-electrical transduction (MET) channels that are located at the tips of stereocilia (Velez-Ortega, et al., eLife, 2017). We found that the blockage of MET channels or the breakage of their gating tip links leads to the shortening of stereocilia; but once the blockage is removed or the tip links regenerate, stereocilia are able to regrow. Based on the changes in stereocilia height in response to variations in the resting MET current, I hypothesized that the stereocilia actin cytoskeleton exhibits activity-dependent plasticity. Aim 2 of the parent grant (R21 DC017247) has been studying the contribution of myosin XV isoforms in the MET-dependent regulation of stereocilia height using several myosin XV mutant mice. Our results thus far indicate that the two types of mammalian auditory hair cells (inner vs. outer hair cells) have different molecular mechanisms driving the MET-dependent changes in the stereocilia cytoskeleton. In addition, we have observed interesting MET-dependent changes to the resting tilt of the hair bundle that could arise from changes at the level of the stereocilia rootlets and/or the cuticular plate. The goal of this Administrative Supplement is to obtain resources (for personnel and supplies) that would allow us to perform focused ion beam scanning electron microscopy (FIB-SEM) imaging to (i) answer some questions that traditional SEM imaging has not been able to address due to the difficulty in obtaining accurate 3D measurements of the extremely short stereocilia in some myosin XV mutants; and, using the same FIB-SEM data sets, to (ii) further explore the mechanotransduction-dependent rearrangements of the stereocilia rootlets and/or cuticular plate. In addition, this supplement would allow Dr. Velez-Ortega to spend less time on the bench performing experiments and, instead, more time on data analysis and manuscript preparation. This `shift' in the focus of Dr. Velez-Ortega's effort would minimize a decrease in the progress of the parent grant due to the upcoming birth of her child in the Fall of 2020.

项目摘要/摘要 立体胶质是内耳感觉毛细胞的感觉机制。我们发现 这些充满肌动蛋白的投影取决于钙通过机械电源的恒定涌入 位于Stereocilia尖端的转导（MET）通道（Velez-Ortega等，Elife，2017年）。 我们发现，MET通道的阻塞或他们的门控尖端链接的断裂导致 缩短立体膜；但是，一旦删除了阻塞或尖端链接再生，立体cil是 能够再生。基于立体胶质高度的变化，响应于静止的变化 电流，我假设立体肌动蛋白细胞骨架表现出活性依赖性可塑性。 父母赠款的目标2（R21 DC017247）一直在研究肌球蛋白XV同工型的贡献 在使用几只肌球蛋白XV突变小鼠的立体胶质高度的依赖性调节中。我们的结果 到目前为止，两种类型的哺乳动物听觉毛细胞（内毛和外毛细胞）具有 不同的分子机制驱动了立体核细胞骨架中元素依赖性变化。在 此外，我们已经观察到了有趣的Met依赖性变化，使头发束的静止倾斜 可能是由立体胶根和/或表皮板的水平上的变化引起的。 这种行政补充的目的是获得资源（对于人员和用品） 将使我们能够执行聚焦的离子光束扫描电子显微镜（FIB-SEM）成像到（i） 回答传统SEM成像由于困难而无法解决的一些问题 在某些肌球蛋白XV突变体中，获得极短的立体胶质的准确3D测量；和， 使用相同的FIB-SEM数据集，以（ii）进一步探索机械传输依赖性的 立体胶根和/或表皮板的重排。此外，该补充将允许 Velez-Ortega博士花更少的时间在表演实验的板凳上，而是更多的时间 数据分析和手稿准备。 Velez-Ortega博士努力的重点的“转变”将 最大程度地减少由于秋天的孩子即将出生而导致的父母赠款的下降 2020年。