Cytoskeletal stability in stereocilia maintenance

静纤毛维持中的细胞骨架稳定性

基本信息

批准号：
10163153
负责人：
BENJAMIN J PERRIN
金额：
$ 38.54万
依托单位：
INDIANA UNIV-PURDUE UNIV AT INDIANAPOLIS
依托单位国家：
美国
项目类别：
财政年份：
2017
资助国家：
美国
起止时间：
2017-06-01 至 2022-08-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10163153
关键词：
Actin-Binding Protein Actins Address Adult Affect Aging Apical Auditory Back Behavior Biological Assay CDH23 gene Cell physiology Cell surface Cells Crosslinker Cytoskeletal Proteins Data Development Distal Excision Filament Functional disorder Genes Hair Cells Half-Life Health Hearing Homeostasis Knockout Mice Labyrinth Length Life Link Maintenance Mammals Measures Microfilaments Modeling Monitor Morphology Movement Mus Mutant Strains Mice Mutation Natural regeneration Neonatal Organism Photobleaching Process Protein Dynamics Protein Isoforms Proteins Regulation Reporter Role Sensory Sensory Hair Side Structure Surface Telomere Length Maintenance Testing Transfection Transgenic Mice Transgenic Organisms base cellular microvillus cofilin deafness destrin experimental study fascin hearing impairment in vivo insight mechanotransduction mouse model mutant new therapeutic target novel overexpression polymerization progressive hearing loss protein crosslink protein expression protein function repaired sound stem treadmill

Actin-Binding Protein Actins Address Adult Affect Aging Apical Auditory Back Behavior Biological Assay CDH23 gene Cell physiology Cell surface Cells Crosslinker Cytoskeletal Proteins Data Development Distal Excision Filament Functional disorder Genes Hair Cells Half-Life Health Hearing Homeostasis Knockout Mice Labyrinth Length Life Link Maintenance Mammals Measures Microfilaments Modeling Monitor Morphology Movement Mus Mutant Strains Mice Mutation Natural regeneration Neonatal Organism Photobleaching Process Protein Dynamics Protein Isoforms Proteins Regulation Reporter Role Sensory Sensory Hair Side Structure Surface Telomere Length Maintenance Testing Transfection Transgenic Mice Transgenic Organisms base cellular microvillus cofilin deafness destrin experimental study fascin hearing impairment in vivo insight mechanotransduction mouse model mutant new therapeutic target novel overexpression polymerization progressive hearing loss protein crosslink protein expression protein function repaired sound stem treadmill

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项目摘要

PROJECT SUMMARY Progressive hearing loss is a prevalent health problem that often stems from the loss or dysfunction of sensory hair cells in the inner ear. Hair cell function depends on actin-based protrusions called stereocilia to detect the physical movement of sound. Functional stereocilia must be maintained for the life of an organism since hair cells are not renewed or regenerated. Thus, stereocilia homeostasis is critical for continued auditory function. Tip links transmit force from stereocilia deflection to gate associated mechanotransduction channels found at stereocilia tips. Rows of stereocilia that normally have active channels also have more actin incorporation at their tips. In addition, mutations in the Cdh23 gene, which encodes the tip link component cadherin-23, strongly influence progressive hearing loss and stereocilia length maintenance in mouse models. Together, these data suggest that tip links or mechanotransduction regulates actin dynamics in stereocilia. Recently, we and others found that stereocilia actin cores are highly stable, except at stereocilia tips, where there is more dynamic actin turnover. However, several unanswered questions remain including whether actin binding proteins in stereocilia are similarly stable, how the stereocilia actin core is made to be stable and whether actin core instability directly influences progressive hearing loss. It is also unclear how the dynamic region of actin at stereocilia tips is regulated and if it contributes to stereocilia length maintenance. To address these questions, we will use transgenic reporters to monitor the dynamics of actin and the actin crosslinker fascin-2 in vivo and ex vivo, both in normal mice and in mice with deafness causing mutations in actin binding proteins found in stereocilia. We also hypothesize that stereocilia stability is particularly critical for stereocilia maintenance when tip links break. This model will be tested by measuring actin incorporation as Cdh23 expression is varied. If stereocilia shorten following tip link loss, then actin polymerization would be required to extend stereocilia back to their original length. We have found that the actin severing proteins destrin and cofilin localize to stereocilia tips, and we will determine if they promote new actin incorporation within the dynamic tip zone. Together, these experiments will provide critical insights into the roles of both extraordinarily stable and more dynamic regions of the actin core in maintaining functional stereocilia.

项目摘要渐进的听力损失是一个普遍的健康问题，通常从感官的损失或功能障碍中脱颖而出内耳中的毛细胞。毛细胞功能取决于基于肌动蛋白的蛋白质，称为立体尾依性来检测声音的身体运动。由于头发细胞未更新或再生。这对于持续听觉功能至关重要。尖端连接从立体旋转示范到栅极相关的机械转导通道的发射力。立体尾tip。通常具有活跃渠道的立体胶体行也有更多的肌动蛋白行业他们的提示。另外，编码尖端链接成分钙粘蛋白23的CDH23基因中的突变，在小鼠模型中强烈影响渐进性听力损失和立体胶质长度维持。一起，这些数据表明，尖端链接或机械转导调节立体胶质中的肌动蛋白动力学。最近，我们其他人发现立体胶质肌动蛋白核是高度稳定的，除了立体尾尖，还有更多动态肌动蛋白周转率。但是，仍然存在几个未解决的问题，包括肌动蛋白是否具有约束力立体胶质中的蛋白质同样稳定，立体尾肌动蛋白核如何稳定以及肌动蛋白是否稳定核心不稳定性直接影响渐进的听力损失。还不清楚肌动蛋白的动态区域如何在立体尾尖，是否有助于立体连续长度维持。解决这些问题，我们将使用转基因记者监测肌动蛋白的动态和肌动蛋白交联fascin-2 在正常小鼠和死亡性的小鼠中，体内和Ex ex ex and Vivo，导致肌动蛋白结合蛋白的突变在立体中发现。我们还假设立体胶质稳定性对于立体cilia尤其至关重要当小费链接断裂时维护。该模型将通过将肌动蛋白行业作为CDH23进行测试表达方式变化。如果立体胶质缩短了小费链路损失后，则需要肌动蛋白聚合将立体胶质扩展到原始长度。我们发现肌动蛋白切断了蛋白质破坏蛋白和 cofilin本地化为立体质丝提示，我们将确定它们是否在动态尖端区域。这些实验将共同提供对两个非凡角色的关键见解肌动蛋白核心在维持功能性立体胶质方面的稳定且动态的区域。