A Bio-Inspired Artificial Transcription Factor for Regeneration of Functional Hair Cells

项目摘要 儿童早期的听力损失会显著影响学习和社交技能的获得， 成年人的丧失往往会导致社会孤立和无法履行许多日常社会职能。领先的 感音神经性听力损失的原因是内耳感觉毛细胞的损失。一辈子都暴露在 氨基糖苷类和响亮的声音将导致估计15%的成年美国人（约3600万）有一些 听力损失的类型细胞替代疗法是一种很有前途的减轻听力损失和耳聋的方法 通过将支持细胞转分化为毛细胞不幸的是，目前的转分化方法 依赖病毒递送对于临床转化可能是不安全和不切实际的。因此，迫切需要 开发替代平台来调节基因表达，并以一种有效的、非病毒的 适合听力恢复的方法。 为此，我们的长期目标是开发NanoScript，一种创新的、可调的基于纳米颗粒的人工 本发明涉及能够以非病毒方式有效调节基因表达的转录因子平台。使用 NanoScript，我们将支持细胞转分化为功能性毛细胞。NanoScript由一个 用特定的小分子和肽功能化的纳米颗粒， 天然转录因子（TF）蛋白的结构域。TF是内源性的多结构域蛋白， 许多细胞功能包括分化。由于NanoScript是TF蛋白的功能复制品，因此它可以 替代病毒递送的TF用于基于再生医学的应用。本提案的总体目标是 是设计三种Nanoparticles，其模拟毛细胞分化所必需的三种TF（Gfi1、Pou4f3和Atoh1; GPA）。我们将测试GPA-NanoScript是否与相同的DNA序列结合并激活基因表达。 体外接下来，我们将确定向GPA-NanoScript添加表观遗传调节剂是否会结合相同的靶点。 如TF蛋白，局部改变染色质结构并增强基因表达。最后，我们将使用 耳蜗外植体，以确定GPA-NanoScript是否促进支持细胞转分化为 毛细胞使用离体模型生成新生毛细胞将作为测试NanoScript的跳板 再生医学技术。它还将使NanoScript成为一种有效的非病毒工具， 研究人员通过直接重编程产生功能细胞。

PROJECT SUMMARY Hearing loss during early childhood significantly affects learning and acquisition of social skills, while hearing loss in adults can often result in social isolation and inability to perform many routine social functions. A leading cause of sensorineural hearing loss is the loss of sensory hair cells of the inner ear. A lifetime exposure to aminoglycoside and loud sounds will result in an estimated 15% of adult Americans (~36 million) having some form of hearing loss. A promising approach to mitigate hearing loss and deafness is a cell replacement therapy by transdifferentiating supporting cells into hair cells. Unfortunately, current approaches for transdifferentiation rely on viral delivery may be unsafe and impractical for clinical translation. Therefore, there is a critical need to develop alternative platforms to regulate gene expression and induce transdifferentiation in an efficient, non-viral manner suitable for hearing restoration. To this end, our long-term goal is to develop NanoScript, an innovative, tunable nanoparticle-based artificial transcription factor platform capable of effectively regulating gene expression in a non-viral manner. Using NanoScript, we will transdifferentiate supporting cells into functional hair cells. NanoScript consists of a nanoparticle functionalized with specific small molecules and peptides that are designed to mimic the individual domains of natural transcription factor (TF) proteins. TFs are endogenous, multi-domain proteins that orchestrate many cellular functions including differentiation. Since NanoScript is a functional replica of TF proteins, it can replace virally-delivered TFs for regenerative medicine-based applications. The overall objective of this proposal is to design three NanoScripts that mimic three TFs essential for hair cell differentiation (Gfi1, Pou4f3, and Atoh1; GPA). We will test whether GPA-NanoScript binds to the same DNA sequence and activate gene expression in vitro. Next we will determine if addition of epigenetic modulators to GPA-NanoScript will bind to the same targets as the TF proteins, locally alter the chromatin structure and enhance gene expression. Finally, we will use cochlear explants to determine whether GPA-NanoScript promotes transdifferentiation of supporting cells into hair cells. Generation of nascent hair cells using an ex vivo model will serve as a springboard to test NanoScript technology for regenerative medicine. It will also establish NanoScript as an effective and non-viral tool for researchers to generate functional cells via direct reprogramming.