Role of Sox2 in Specification of Prosensory and Hair Cell Fate in Mouse Cochlea

Sox2 在小鼠耳蜗前感觉和毛细胞命运规范中的作用

• 批准号: 8388143
• 负责人: Chandrakala Puligilla
• 金额: $ 24.9万
• 依托单位: MEDICAL UNIVERSITY OF SOUTH CAROLINA
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-12-01 至 2014-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8388143
• 关键词: Address; Award; Biologically Based Therapy; Cell Differentiation process; Cells; Cochlea; Cochlear Implants; Data; Development; E-Cadherin; Elements; Epithelium; Gene Targeting; Goals; Hair Cells; Hearing; In Vitro; Inner Hair Cells; Instruction; Knowledge; Labyrinth; Lead; Mediating; Molecular; Multipotent Stem Cells; Mus; N-Cadherin; Organ of Corti; Outer Hair Cells; Pathway interactions; Pattern; Phase; Play; Positioning Attribute; Recovery; Research; Role; Sensory; Sensory Hair; Signal Pathway; Signal Transduction; Stem cells; Supporting Cell; base; cell determination; cell fate specification; cell type; chromatin immunoprecipitation; hearing impairment; in vivo; insight; loss of function; otoconia; programs; regenerative; research study; transcription factor

A key step in the development of inner ear sensory epithelia is the commitment of multipotent progenitor cells in otocyst to a prosensory fate, defined by the ability to give rise to either hair cells or support cells. However, the factors that confer prosensory fate to these cells are only beginning to be identified. Recent studies have shown that the HMG class transcription factor Sox2 is dynamically expressed in prosensory cells and is required for the formation of this cell type. However, the specific roles of Sox2, and in particular whether it can induce prosensory identity, has not been determined. The main goals of the experiments described in this proposal are to use a combination of in vivo and in vitro approaches to determine the specific effects of Sox2 during cochlear development and further, to determine whether some or all of these effects are mediated through the candidate downstream effectors, Proxl, E-cadherin, and N-cadherin. During the K99 phase of the award, progress has been made towards the completion of all three aims. The first aim that was proposed as part of K99 focussed on the specific roles of Sox2 in regulating prosensory, and ultimately hair cell specification. Our results demonstrate that transient activation of Sox2 leads to ectopic hair cell formation, suggesting a direct role of Sox2 in the induction of Atohl, a conclusion that was confirmed by chromatin immunoprecipitation analysis. In addition, our data show that induction of prosensory identity is essential for hair cell formation and that hair cells must go through a "prosensory cell" phase prior to hair cell differentiation. In the second aim, the relationship between Sox2 and the putative Sox2-target gene, E-cadherin, will be examined. Gain- & loss-of function in vivo and in vitro experiments will be used to determine whether the effects of Sox2 on cell fate and patterning are mediated through E-cadherin. In the final aim, the role of N-cadherin, a known target of Sox2, in determination of cell fate and cellular patterning will be examined. Moreover, experiments examining the specific effects of modulation of E-cadherin and Ncadherin signaling & the relationship of these two molecules to Sox2 should provide insights into the signaling pathways that direct cells towards hair cell fate.

内耳感觉上皮细胞发育的一个关键步骤是多能祖细胞的定向分化 听囊中的毛细胞向前感觉细胞的命运转变，由产生毛细胞或支持细胞的能力来定义。 然而，赋予这些细胞前感觉命运的因素才刚刚开始被确定。最近 研究表明，HMG类转录因子Sox 2在前感觉细胞中动态表达， 细胞，是形成这种细胞类型所必需的。然而，Sox 2的具体作用，特别是 它是否能诱导前感觉同一性还没有确定。实验的主要目的 本提案中描述的是使用体内和体外方法的组合来确定 Sox 2在耳蜗发育过程中的特定作用，并进一步确定这些作用中的一些或全部是否 作用通过候选下游效应物Prox 1、E-钙粘蛋白和N-钙粘蛋白介导。 在K99阶段的奖励中，在实现所有三个目标方面都取得了进展。的 作为K99的一部分提出的第一个目标集中在Sox 2在调节前感觉中的特定作用， 最终影响毛细胞的特化。我们的研究结果表明，Sox 2的瞬时激活导致 异位毛细胞形成，表明Sox 2在Atohl诱导中的直接作用， 通过染色质免疫沉淀分析证实。此外，我们的数据表明，诱导前感觉 同一性对于毛细胞形成是必不可少的，且毛细胞必须在 毛细胞的分化。在第二个目标中，Sox 2和假定的Sox 2-靶标之间的关系 将检查E-钙粘蛋白基因。体内和体外功能获得和丧失实验将用于 确定Sox 2对细胞命运和模式的影响是否通过E-钙粘蛋白介导。在 最后一个目标，N-钙粘蛋白，一个已知的Sox 2的目标，在决定细胞命运和细胞模式中的作用 将被审查。此外，检测E-钙粘蛋白和N-钙粘蛋白的调节的特定作用的实验 这两种分子与Sox 2的关系应该提供了对 这些信号通路引导细胞走向毛细胞的命运。