Molecular and functional characterization of type I and II vestibular hair cells in adult mice

成年小鼠 I 型和 II 型前庭毛细胞的分子和功能特征

• 批准号: 10749188
• 负责人: Amanda Nichole Ciani
• 金额: $ 4.77万
• 依托单位: UNIVERSITY OF WASHINGTON
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-07-06 至 2025-06-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10749188
• 关键词: Ablation; Adult; Age; Aging; Animal Behavior; Animals; Behavior; Bioinformatics; Brain Stem; Cells; Cellular biology; Cerebellum; Classification; Data; Development; Dissection; Epithelium; Equilibrium; Exposure to; Eye Movements; Functional disorder; Future; Gene Expression; Genes; Genetic Transcription; Goals; Hair Cells; Head; Head Movements; Human; In Situ Hybridization; Knowledge; Label; Location; Mammals; Measurement; Measures; Mentors; Messenger RNA; Molecular; Molecular Biology; Molecular Profiling; Morphology; Motion; Motor; Mus; Natural regeneration; Nerve; Organ; Patients; Peripheral; Personal Satisfaction; Pharmaceutical Preparations; Physiological; Physiology; Population; Property; Proteins; Publications; Quality of life; Research; Research Personnel; Research Training; Rotarod Performance Test; Sensory; Sensory Receptors; Space Perception; Stimulus; Supporting Cell; System; Tamoxifen; Technology; Test Result; Testing; Type I Hair Cell; Type II Hair Cell; Universities; Utricle structure; Vestibular Hair Cells; Vestibular Nerve; Work; afferent nerve; balance testing; behavior test; cell injury; cell regeneration; cell type; epithelial repair; equilibration disorder; experience; follow-up; functional restoration; hair cell regeneration; improved; insight; interest; molecular marker; nerve supply; normal aging; notch protein; novel; novel marker; novel therapeutics; ototoxicity; ototoxin; protein expression; response; single nucleus RNA-sequencing; single-cell RNA sequencing; therapy development; tool; transcriptomics; vestibulo-ocular reflex

Project Abstract The sensory receptors for mammalian vestibular organs, called hair cells, encode head movements and relay information along the vestibular nerve to the brainstem and cerebellum. Mammals have two types of hair cell, type I and type II, which different morphological and physiological properties. Type I and II hair cells also have distinct forms of afferent innervation that are differentially distributed across the epithelial zones. Vestibular hair cells die during normal aging and after exposure to ototoxins, and this loss can lead to profound vestibular deficits. After vestibular hair cell damage in adult mice, supporting cells regenerate ~50% of type ll hair cells, but no type I hair cells are replaced. This natural hair cell regeneration does not restore the vestibular system to normal function, as measured by the vestibulo-ocular reflex and other behavioral tests. One interpretation of this finding is that type I hair cells must be replaced in mammals for vestibular function to return. While this is tempting to speculate, there is little evidence that type I hair cells are required for specific vestibular functions. Indeed, we understand little about the respective contributions of type I and II hair cells to our vestibular sense. One step toward solving this puzzle is to use molecular biology to better understand the unique features of each hair cell type and to determine if subtypes of type I and II hair cells exist. Working with Drs. Neil Segil and Litao Tao, I found from single cell RNA sequencing that there seem to be four molecularly distinct populations of hair cells in adult mouse utricles: two type l-like populations, one type ll-like population, and one unknown group of hair cells. In Aim 1, I will continue these studies, examining expression of candidate cell-specific genes in all vestibular organs to determine if four distinct hair cell groups are identifiable in each organ and how these groups are distributed across epithelial zones. I will generate novel insights into hair cell features across vestibular organs, classify new markers for each cell type, and identify genes that may be used to drive cell-selective gene misexpression in future studies. Another step toward testing the different functions of type I and II hair cells is to remove each hair cell population and assess impacts on vestibular function. In Aim 2, I will use CreLoxP technology to ablate all type I hair cells or peripheral type I hair cells in all adult vestibular organs. I will determine the impact of these ablations upon animal behaviors and brainstem electrical responses to vestibular stimuli, which to my knowledge has not been done before in adult mice. I expect to gain new insights into the general function of type I hair cells and the specific functions of type I hair cells in each epithelial zone. Overall, this research provides new information about properties and functions of type I and II hair cells and inform on new therapies to treat balance disorders. Further, this project enables me to receive top-notch research training in a collaborative setting using cutting-edge scientific approaches.

项目摘要 哺乳动物前庭器官的感觉感受器，称为毛细胞，编码头部运动 并将信息沿着前庭神经传递到脑干和小脑。哺乳动物有两种 毛细胞分为I型和II型，它们具有不同的形态和生理特性。I型和II型毛细胞 也具有不同形式的传入神经支配，其在上皮区中有差异地分布。 前庭毛细胞在正常衰老过程中和暴露于耳毒素后死亡，这种损失可导致严重的 前庭缺陷成年小鼠前庭毛细胞损伤后，支持细胞再生~50%的II型 毛细胞，但没有I型毛细胞被取代。这种自然的毛细胞再生并不能恢复 前庭系统恢复正常功能，如前庭眼反射和其他行为测试所测量。 对这一发现的一种解释是，哺乳动物的I型毛细胞必须被替换，以实现前庭功能， 回报.虽然这是诱人的推测，但几乎没有证据表明I型毛细胞是特定的细胞所必需的。 前庭功能事实上，我们对I型和II型毛细胞各自的贡献知之甚少， 我们的前庭感觉。 解决这个难题的一个步骤是使用分子生物学来更好地理解这种独特的生物学。 每种毛细胞类型的特征，并确定是否存在I型和II型毛细胞的亚型。与博士一起工作。 Neil Segil和Litao Tao，我从单细胞RNA测序中发现， 成年小鼠椭圆囊中毛细胞的不同群体：两个L型样群体，一个II型样群体， 和一组未知的毛细胞在目标1中，我将继续这些研究，检查 所有前庭器官中的候选细胞特异性基因，以确定四种不同的毛细胞群是否可识别 以及这些组在上皮区中的分布。我会对这些问题 前庭器官的毛细胞特征，为每种细胞类型分类新的标记，并识别可能 在未来的研究中用于驱动细胞选择性基因错误表达。另一个测试不同 I型和II型毛细胞的功能是去除每个毛细胞群，并评估对前庭神经的影响。 功能在目标2中，我将使用CreLoxP技术消融所有I型毛细胞或外周I型毛细胞， 都是成年人的前庭器官我将确定这些消融对动物行为和脑干的影响， 对前庭刺激的电反应，据我所知，这在成年小鼠中还没有做过。我 期望对I型毛细胞的一般功能和I型毛发的特殊功能有新的认识 每一个上皮细胞。总的来说，这项研究提供了新的信息的性质和功能， I型和II型毛细胞并提供治疗平衡障碍的新疗法的信息。此外，这个项目使我 接受一流的研究培训，在合作环境中使用尖端的科学方法。