Notch signaling pathways in auditory support cell differentiation and maintenance

Notch信号通路在听觉支持细胞分化和维持中的作用

基本信息

批准号：
8812731
负责人：
ANGELIKA DOETZLHOFER
金额：
$ 40.59万
依托单位：
JOHNS HOPKINS UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2011
资助国家：
美国
起止时间：
2011-03-01 至 2016-02-29
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8812731
关键词：
Ablation Address Adopted Adult Aminoglycosides Auditory Birds Cell Communication Cell Differentiation process Cell Lineage Cell Maintenance Cell division Cells Cochlea Cues Data Development Diuretics Epithelial Cells Future Gene Expression Genetic Recombination Global Change Goals Hair Cells Health Human In Situ Hybridization Injection of therapeutic agent Knowledge Label Lead Light Maintenance Mammals Mediating Molecular Mus Mutant Strains Mice Natural regeneration Neuraxis Neuroglia Notch Signaling Pathway Null Lymphocytes Organ Organ of Corti Pathway interactions Peripheral Phenotype Play Replacement Therapy Reporter Role Sensory Sensory Hair Signal Pathway Signal Transduction Staining method Stains Supporting Cell Tamoxifen Testing Time Vertebrates Work base cell injury cell type deafness equilibration disorder hair cell regeneration high throughput analysis improved inhibitor/antagonist insight notch protein novel prevent progenitor programs public health relevance receptor research study response secretase

项目摘要

DESCRIPTION (provided by applicant): In humans and other mammalian species, damage to mechano-sensory hair cells is irreversible, leading to deafness and balance disorders. Remarkably, non-mammalian vertebrates regenerate lost hair cells. In birds, supporting cells have been shown to replace lost hair cells by mechanisms involving either cell division or direct trans-differentiation. In the mammalian auditory sensory organ, supporting cells do not regenerate lost hair cells. Strikingly, our findings suggest that mammalian supporting cells retain the intrinsic ability to function as hair cell progenitors, but their plasticity to regenerate hair cells is actively suppressed by external inhibitory cues. Our long-term goal is to utilize the latent plasticity of supporting cells to develop supporting cell based hair cell replacement strategies. To attain this goal, it is vital to improve our knowledge of the molecular programs active in developing and in mature supporting cells. We reason that to "reprogram" and induce de- differentiation of supporting cells and consequently trans-differentiation of supporting cells into hair cells, we first have to understand the signals that control differentiation and maintenance in the supporting cell lineage. The goal of this proposal is to determine if the Notch signaling pathway, an evolutionary ancient and highly conserved cell-to-cell communication mechanism, functions in supporting cell differentiation and cell maintenance. In Specific Aim 1 of our proposal, we will test if Notch signaling plays an instructive role in supporting cell differentiation. We will test if induction of an activated form of the Notch1 receptor is sufficient to induce supporting cell fate and whether inhibition of Notch signaling with 3-secretase inhibitors effects the onset and progression of supporting cell differentiation. In Specific Aim 2 of our proposal, we will ablate Rbpj, a core component of the canonical Notch signaling pathway, in supporting cells to address if Notch signaling is required for supporting cell maintenance in the intact and hair cell damaged cochlea. To do so we will employ Rbpj conditional mouse mutants in combination with tamoxifen inducible CreERT lines. We anticipate that this analysis will provide valuable insight into the molecular mechanisms that drive supporting cell differentiation and elucidate the function of Notch signaling in supporting cell maintenance in the adult cochlea. In parallel, we will address a longstanding question-"does persistence of Notch signaling in the hair cell damaged cochlea underlie the lack of hair cell regeneration in mammals?" Addressing this question is relevant to human health as inhibiting Notch signaling using 3-secretase inhibitors in mature cochlea could provide a means for restoring a latent capacity to regenerate hair cells.

描述（由申请人提供）：在人类和其他哺乳动物物种中，机械感官毛细胞的损害是不可逆的，导致耳聋和平衡疾病。值得注意的是，非哺乳动物脊椎动物会再生毛细胞损失的细胞。在鸟类中，已证明辅助细胞通过涉及细胞分裂或直接反差异的机制来代替丢失的毛细胞。在哺乳动物的听觉感觉器官中，支撑细胞不会再生损失的毛细胞。令人惊讶的是，我们的发现表明，哺乳动物的辅助细胞保留了充当毛细胞祖细胞的内在能力，但是它们的可再生毛细胞的可塑性被外部抑制性提示积极抑制。我们的长期目标是利用支撑细胞的潜在可塑性来发展基于细胞的毛细胞替代策略。为了实现这一目标，提高我们对积极发展和成熟支持细胞的分子程序的了解至关重要。我们认为，要“重新编程”并诱导支撑细胞的分化，并因此将支持细胞跨分化为毛细胞，我们首先必须了解控制支持细胞谱系中分化和维持的信号。该提案的目的是确定Notch信号通路，一种进化的古代和高度保守的细胞间通信机制，在支持细胞分化和细胞维持方面的功能。在我们的提案的特定目的1中，我们将测试Notch信号是否在支撑细胞分化中起有启性的作用。我们将测试Notch1受体的激活形式是否足以诱导支撑细胞命运，以及使用3-分泌酶抑制剂对Notch信号的抑制是否影响支撑细胞分化的开始和发展。在我们的提案的特定目的2中，我们将在支持细胞的支持细胞中消融RBPJ，这是在支持细胞的支持细胞中，以解决是否需要Notch信号来支持完整和毛细单元损坏的耳蜗中的细胞维护。为此，我们将使用RBPJ有条件的小鼠突变体和他莫昔芬诱导的Creert线结合使用。我们预计，该分析将为驱动支撑细胞分化的分子机制提供宝贵的见解，并阐明Notch信号在支持成人耳蜗中支撑细胞维持方面的功能。同时，我们将解决一个长期存在的问题：“毛细胞中缺口信号的持久性是否损坏的耳蜗是哺乳动物缺乏毛细胞再生的基础？”解决这个问题与人类健康有关，因为在成熟的耳蜗中使用3-分泌酶抑制剂抑制Notch信号传导可以提供一种恢复潜在再生毛细胞的能力的方法。