A Novel Model System for Restoring Hearing in vivo

项目摘要/摘要 大约每400名儿童中就有1名出生时听力严重受损，这使得先天性耳聋成为 影响幼儿的最常见的疾病。大约50%的先天性耳聋是遗传性的 起源。目前，唯一可用的听力损失治疗方法是人工耳蜗或听力放大。 虽然这些治疗通常会改变生活，但它们恢复正常听力的能力有限， 这导致了终生的挣扎从童年就开始了。治疗的基因治疗方法 隐性听力损失提供了一个具有挑战性但令人兴奋的机会。将功能基因以病毒形式传递到 EAR是具有挑战性的，特别是在小鼠身上--目前的体内病毒传递方法只转导了一小部分 感觉毛细胞是正常听力所必需的，而且只对较小的蛋白质很容易起作用。此外， 可能需要多次应用病毒载体来瞄准最佳的治疗时机和持续时间。老鼠 缺乏肌动蛋白调节蛋白Eps8的人类是聋人，而Eps8 KO小鼠的立体纤毛非常短 它们不能接触到科尔蒂器官的覆盖膜。一种新的转基因小鼠品系将是 用于研究聋人Eps8 KO小鼠模型出生后基因表达的潜力。使用 PhyB系统，将创建一个小鼠系，其中任何受UAS控制的转基因的表达都可以 红灯激活或远红光灭活。利用该系统，UAS-Eps8在体内的表达将 红灯或多西环素引起的。系统地改变Eps8表达的起始和持续时间， 然后，测试听力功能和立体纤毛延长将有助于恢复立体纤毛的潜力。 出生后小鼠的体内伸长和听力恢复。此外，EPS8在这两种发育中的作用 在生物体的整个生命周期中，立体纤毛的维持将在未来的研究中得到阐明。总的来说， 这一建议将为未来许多探索基因表达调控在脑内的影响的项目铺平道路。 VIVO将为探索和扩大艾滋病的关键期提供一个创新而实用的模式体系 听力恢复。

Project Summary/Abstract Approximately 1 out of 400 children are born with significant hearing loss, making congenital deafness one of the most common disorders affecting young children. Approximately 50% of congenital deafness is genetic in origin. Currently, the only available treatments for hearing loss are cochlear implants or hearing amplification. While these treatments are often life-changing, they are limited in their ability to restore hearing to normal, which results in lifelong struggles beginning acutely in childhood. Gene therapy approaches for treating recessive hearing loss presents a challenging but exciting opportunity. Viral delivery of functional genes to the ear is challenging, especially in mice – current in vivo viral delivery methods only transduce a fraction of the sensory hair cells necessary for proper hearing function, and only works easily for smaller proteins. Moreover, multiple applications of viral vectors may be required to target the optimal timing and duration for therapy. Mice and humans lacking the actin-regulatory protein Eps8 are deaf, and Eps8 KO mice have very short stereocilia that fail to contact the tectorial membrane in the organ of Corti. A novel transgenic mouse line will be generated to study the potential of postnatal gene expression in a deaf Eps8 KO mouse model. Using the PhyB system, a mouse line will be created wherein any UAS controlled transgene’s expression can be activated with red light or inactivated with far-red light. Using this system, UAS-Eps8 expression in vivo will be induced by either red light or doxycycline. Systematically varying the initiation and duration of Eps8 expression, then testing for hearing function and stereocilia elongation will facilitate the restoration potential of stereocilia elongation and hearing restoration in vivo in postnatal mice. Furthermore, the role of Eps8 in both development and maintenance of stereocilia over the lifetime of the organism will be elucidated in future studies. Overall, this proposal will pave the way for many future projects probing the effects of gene expression modulation in vivo and will provide an innovative but practical model system for probing and expanding the critical period for hearing restoration.