Molecular basis of mammalian cochlear regeneration

哺乳动物耳蜗再生的分子基础

基本信息

批准号：
10682272
负责人：
Alan Gi-Lun Cheng
金额：
$ 67.63万
依托单位：
STANFORD UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2023
资助国家：
美国
起止时间：
2023-05-01 至 2028-04-30
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10682272
关键词：
Ablation Adult Affect Auditory Automobile Driving Bioinformatics Biological Models Biophysics Candidate Disease Gene Cell Differentiation process Cell Maturation Cell Nucleus Cell Proliferation Cell Size Cells Cochlea Cochlear Implants Coin Data Development Diphtheria Toxin Electric Capacitance Electrophysiology (science)Epithelium Fingerprint GFI1 gene Genes Genetic Goals Hair Hair Cells Hearing Hearing Aids Homer 1 Human Image In Situ Hybridization In Vitro Inner Hair Cells Inner Supporting Cell Knowledge LGR5 gene Labyrinth Lateral Mammals Maps Maturation-Promoting Factor Measures Medial Membrane Mitotic Modeling Molecular Mus Natural regeneration Neonatal Organ of Corti Otologic Surgical Procedures Outer Hair Cells Pathology Pattern Persons Population Proliferating Property Proteins Publishing Radial Research Role SLC17A8 gene Sensorineural Hearing Loss Sensory Hair Structure Supporting Cell Synapses Technology Testing Transgenic Mice Viral Work activating transcription factor 3 cell age cell motility cell regeneration combinatorial enhancing factor experimental study genetic signature hair cell regeneration hearing impairment improved in vitro regeneration in vivo insight live cell imaging mechanotransduction migration molecular marker mouse model neonatal mice nerve supply novel novel marker overexpression permanent hearing loss postsynaptic presynaptic progenitor programs rat Pres protein single nucleus RNA-sequencing spatiotemporal transcription factor transcriptome transcriptome sequencing transdifferentiation

项目摘要

Abstract: Sensorineural hearing loss affects 1.5 billion people worldwide, with the primary pathology being the irreversible loss of cochlear hair cells and supporting cells. Although hearing aids and cochlear implants can improve hearing, we currently lack the ability to reverse the underlying pathology of hearing loss-hair cell and supporting cell loss. Recent studies found that defined transcription factors can reprogram endogenous cochlear supporting cells to directly acquire a hair cell fate, however, the hair cells formed are limited both in number and degree of maturation. Moreover, this non-mitotic approach, coined direct transdifferentiation, leads to a loss of the overall supporting cell population. Thus, a better understanding of 1) mitotic regeneration of supporting cells and 2) how regenerated hair cells in the cochlea mature is critical. In this proposal, we will test whether singular or combinatorial application of transcription factors can replenish hair cells and supporting cells in the immature and mature mouse cochlea. In preliminary and recently published data using transgenic mouse models, we found that 1) greater epithelial ridge (GER) cells, instead of being a transient structure during development, migrate into the organ of Corti to regenerate lost supporting cells and mature to become the supporting cell subtype inner phalangeal cells, which are critical for the survival of inner hair cells, 2) damage induces GER cells to robustly proliferate and upregulate transcription factors associated with proliferation, 3) Atoh1 overexpression robustly induces new hair cell formation in the GER, which mature to become inner hair cell- and outer hair cell-like cells. The first aim will test the hypothesis that damage-responsive transcription factors promote mitotic regeneration in the neonatal and damaged mature cochlea. In the second aim, we will use regenerated hair cells in the GER as a model system to characterize the spatiotemporal features by which regenerated hair cells mature and then test whether the outer hair cell factor Ikzf2 enhances an outer hair cell fate. Moreover, we will examine the ability of combination of hair cell transcription factors to induce hair cell regeneration and maturation in the damaged mature cochlea. To gain an unbiased insight into the genetic signature of ectopic supporting cells and hair cells, the third aim will probe the transcriptomes of GER-derived hair cells and supporting cells. We will reveal their genetic landscape using bioinformatic approaches to define genes marking progenitors and regenerated supporting cells and hair cells and candidate genes driving regeneration. In summary, we will apply state-of-the-art technologies (live cell imaging, electrophysiology, snRNA-seq, inner ear surgery, viral transduction) to study the mechanisms of supporting cell and hair cell regeneration. We have assembled a team of experts who have worked together to collect promising preliminary data. At the end of this 5-year proposal, we will have determined 1) whether transcription factors can enhance cochlear regeneration 2) mechanisms dictating regeneration of supporting cells and hair cells in mammals.

摘要：感官听力损失影响全球15亿人，主要病理是耳蜗细胞和支持细胞的不可逆转丧失。尽管助听器和人工耳蜗可以改善听力，我们目前缺乏扭转听力发行细胞的潜在病理的能力和支持细胞损失。最近的研究发现，定义的转录因子可以重新编程内源性耳蜗支持细胞直接获得毛细胞命运，但是，形成的毛细胞在数量上受到限制，并且成熟程度。此外，这种非有丝质方法的方法是直接转分化的，导致总体支持细胞种群。因此，更好地理解1）支持细胞的有丝分裂再生 2）耳蜗中的再生毛细胞如何至关重要。在此提案中，我们将测试转录因子的单数或组合应用是补充未成熟和成熟小鼠耳蜗中的毛细胞和支撑细胞。在初步和最近使用转基因小鼠模型发布的数据，我们发现1）更大的上皮脊（GER）细胞，而不是作为开发过程中的瞬态结构，迁移到Corti的器官中，以再生损失的支撑细胞并成熟成为支持细胞亚型内羊鼠细胞，这对于生存至关重要内毛细胞，2）损伤会诱导GER细胞牢固地增殖和上调转录因子与增殖相关，3）ATOH1过表达可鲁棒地诱导GER中的新毛细胞形成，该毛细胞形成成熟成为内毛细胞和外毛细胞状细胞。第一个目的将检验以下假设：损害响应性转录因子促进有丝分裂新生儿和损坏的成熟耳蜗的再生。在第二个目标中，我们将使用再生的毛细胞在GER中，作为模型系统，以表征时空特征，再生毛细胞成熟然后测试外毛细胞因子IKZF2是否增强了外毛细胞命运。而且，我们将检查毛细胞转录因子组合诱导毛细胞再生和成熟的能力受损的成熟耳蜗。对异位支持细胞的遗传特征和毛细胞，第三个目标将探测GER衍生的毛细胞和支撑细胞的转录组。我们将使用生物信息学方法来揭示其遗传景观，以定义标记祖细胞和的基因再生支撑细胞，毛细胞和候选基因驱动再生。总而言之，我们将采用最新技术（活细胞成像，电生理学，SNRNA-SEQ，内耳手术，病毒转导）研究支持细胞和毛细胞再生的机制。我们已经组建了一个专家团队，他们共同努力收集有希望的初步数据。在最后在这项为期5年的建议中，我们将确定1）转录因子是否可以增强人工耳蜗再生2）指示哺乳动物中支撑细胞和毛细胞再生的机制。