Examination of the molecular features and function of the hair cell-synaptic complex in the spontaneously and Atoh1-enhanced regenerating adult mouse utricle

检查自发和 Atoh1 增强的成年小鼠椭圆囊再生中毛细胞突触复合体的分子特征和功能

• 批准号: 9300706
• 负责人: Zahra Sayyid
• 金额: $ 4.67万
• 依托单位: STANFORD UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-06-20 至 2021-06-19
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9300706
• 关键词: Acoustic Nerve; Action Potentials; Activities of Daily Living; Adult; Affect; American; Amination; Amines; Biological Response Modifier Therapy; Birds; Cell Count; Cell physiology; Cells; Chickens; Cochlea; Complex; Cre-LoxP; Critical Thinking; Data; Development; Disease; Drug Modelings; Equilibrium; Evoked Potentials; Foundations; Functional disorder; Future; Generations; Goals; Gravity Perception; Hair Cells; Hearing; Histologic; Histology; Human; Impairment; Individual; Knowledge; Laboratories; Labyrinth; Lead; Maps; Measurement; Measures; Mission; Modeling; Molecular; Mus; National Institute on Deafness and Other Communication Disorders; Natural regeneration; Organ; Outcome; Pathology; Patients; Pattern; Pre-Clinical Model; Process; Public Health; Quality of life; Recovery; Recovery of Function; Rehabilitation therapy; Research; Research Personnel; Research Training; Role; Sense Organs; Sensory; Supporting Cell; Symptoms; Synapses; Technical Expertise; Testing; Therapeutic; Time; Transgenic Organisms; United States; United States National Institutes of Health; Utricle structure; Vestibular loss; Work; Zebrafish; base; cell injury; density; disability; experimental study; genetic manipulation; guided inquiry; hair cell regeneration; improved; in vivo Model; in vivo regeneration; insight; mechanotransduction; mouse model; nerve supply; novel therapeutics; overexpression; reduce symptoms; relating to nervous system; spatiotemporal; transcription factor

Project Summary/Abstract Vestibular disorders affect more than 90 million individuals in the United States, leading to challenges with ac- tivities of daily living and impaired overall quality of life. Although vestibular rehabilitation may help alleviate patients’ symptoms, there are currently no biological treatments to reverse vestibular dysfunction. Whereas non-mammalian species such as chickens and zebrafish robustly regenerate the mechanosensory hair cells required for function after damage, the mammalian utricle (gravity-sensing organ) is only capable of limited re- generation. Atoh1, the transcription factor required for hair cell development, has previously been used to in- duce hair cell formation. However, the molecular features and functionality of the regenerated hair cells in the spontaneously and Atoh1-overexpressed regenerating utricles have not been clearly defined. Together, these gaps in knowledge create a critical bottleneck in our attempt to better understand the mechanisms of mature mammalian hair cell regeneration. The overall objective of this proposal is to examine the molecular features and function of the hair cell- synaptic complex in the spontaneously and Atoh1-enhanced regenerating adult mouse utricle. The hypothe- sis is that maturation of the hair cell-synaptic complex correlates with improvement of vestibular function, and that this regeneration can be driven further by Atoh1 overexpression. Completion of the following specific aims should test the central hypothesis and, thereby, attain the objective of this application. Specific Aim 1: Exam- ine molecular features of the spontaneously recovering hair cell-synaptic complex. Specific Aim 2: Restore vestibular function via spatiotemporal genetic manipulation of Atoh1. We will use a Cre-LoxP based transgenic approach to fate-map supporting cells after hair cell damage in mature mice. We will serially evaluate mice for vestibular function and examine utricles histologically up to six months after damage. We will then correlate improved histology with recovery of vestibular function. Successful execution of the work described in this proposal will result in a greater understanding of the mo- lecular features of the hair cell-synaptic complex in the mammalian inner ear. This contribution will be signifi- cant in two ways: first, it will establish an important but poorly understood relationship between hair cell regen- eration and functional recovery. Secondly, it will extend our understanding of the efficacy and limitation of using Atoh1 overexpression to stimulate hair cell regeneration. Such knowledge on inner ear hair cell regeneration in preclinical models will help construct the fundamental building blocks of future therapeutics to restore vestibu- lar function in humans.

项目总结/摘要 前庭障碍影响着美国9000多万人，导致了ac的挑战。 日常生活活动和整体生活质量受损。虽然前庭康复可能有助于减轻 患者的症状，目前还没有生物治疗逆转前庭功能障碍。而 非哺乳动物物种如鸡和斑马鱼强健地再生机械感觉毛细胞 哺乳动物的椭圆囊（重力感应器官）在受损后只能进行有限的修复。 一代Atoh 1是毛细胞发育所需的转录因子，以前曾被用于在 诱导毛细胞形成。然而，再生的毛细胞的分子特征和功能， 自发和Atoh 1过表达的再生胞囊尚未明确定义。所有这些 知识上的差距造成了我们试图更好地理解成熟的机制的关键瓶颈。 哺乳动物毛细胞再生 本提案的总体目标是研究毛细胞的分子特征和功能- 突触复合体在自发和Atoh 1增强再生成年小鼠椭圆囊。皮下组织- SIS是毛细胞-突触复合体成熟与前庭功能的改善相关， 这种再生可以通过Atoh 1过表达进一步驱动。实现以下具体目标 应该检验中心假设，从而达到本申请的目的。具体目标1：考试- 自然恢复的毛细胞-突触复合体的分子特征。具体目标2：恢复 前庭功能通过Atoh 1的时空遗传操作。我们将使用基于Cre-LoxP的转基因 成熟小鼠毛细胞损伤后的命运图支持细胞的方法。我们将连续评估小鼠的 前庭功能，并在损伤后6个月内对椭圆囊进行组织学检查。然后我们将关联 组织学改善，前庭功能恢复。 成功执行本建议书中所述的工作将使人们更好地了解 哺乳动物内耳毛细胞-突触复合体的特征。这一贡献将具有重大意义-- 不能在两个方面：第一，它将建立一个重要的，但知之甚少的毛细胞再生之间的关系， 功能恢复和功能恢复。其次，它将扩展我们对使用的有效性和局限性的理解 Atoh 1过表达刺激毛细胞再生。内耳毛细胞再生的知识， 临床前模型将有助于构建未来治疗的基本组成部分，以恢复前庭， 在人类中最大的功能。