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

项目摘要/摘要 在美国，前庭疾病影响着9000多万人，导致对Ac-Ac的挑战。 日常生活活动和整体生活质量受损。尽管前庭康复可能有助于缓解 对于患者的症状，目前还没有生物治疗方法来逆转前庭功能障碍。鉴于 非哺乳动物物种，如鸡和斑马鱼，旺盛地再生机械感觉毛细胞。 哺乳动物的椭圆体(重力感应器官)在损伤后需要发挥作用，只能有限地恢复 一代。Atoh1是毛细胞发育所需的转录因子，以前曾用于- 杜斯毛细胞形成。然而，再生毛细胞的分子特征和功能 自发的和Atoh1过表达的再生椭圆体还没有明确的定义。加在一起，这些 在我们试图更好地理解成熟的机制时，知识上的差距造成了一个严重的瓶颈 哺乳动物毛细胞再生。 这项建议的总体目标是研究毛细胞的分子特征和功能- 自发性和Atoh1增强的成年小鼠椭圆囊中的突触复合体。假设- SIS是毛细胞-突触复合体成熟与前庭功能改善相关，以及 这种再生可以通过Atoh1的过度表达进一步推动。完成以下具体目标 应该检验中心假设，从而达到这一应用的目的。具体目标1：考试-- 自发恢复的毛细胞-突触复合体的分子特征。具体目标2：恢复 通过Atoh1的时空遗传操作实现的前庭功能。我们将使用基于Cre-loxP的转基因 成年小鼠毛细胞损伤后支持细胞命运图的探讨。我们将对MICE进行系列评估 损伤后6个月进行前庭功能和椭圆囊组织学检查。然后我们将相互关联 随着前庭功能的恢复，组织学有所改善。 成功地执行本建议中所述的工作将使人们更好地理解这项工作。 哺乳动物内耳毛细胞-突触复合体的局部特征。这一贡献将是显著的- 不能在两个方面：首先，它将建立一个重要的，但鲜为人知的毛细胞再生之间的关系- 损伤和功能恢复。其次，它将扩大我们对使用的有效性和局限性的理解 Atoh1过表达可刺激毛细胞再生。关于内耳毛细胞再生的这样的知识 临床前模型将有助于构建未来治疗的基本构件，以恢复前庭- 在人类中具有更大的功能。

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.