COBRE: BOYS TOWN NAT RES HOSP: P4: FORMATION & REGULATION OF OTOCONIA

COBRE：男孩镇 NAT RES HOSP：P4：阵型

• 批准号: 7382086
• 负责人: Yunxia Wang Lundberg
• 金额: $ 27.31万
• 依托单位: UNIVERSITY OF NEBRASKA MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-05-01 至 2007-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7382086
• 关键词: COBRE; BOYS; TOWN; NAT; RES

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Otoconia, crystallites of CaCO3 and proteins, are required for an individual to sense linear acceleration and gravity for spatial orientation and balance control. Dysfunction of this system is a critical clinical problem, particulady in the elderly, yet little is known about the mechanisms that regulate otoconial biosynthesis. Otoconia appear to be in a dynamic state of equilibrium highly susceptible to adverse effects of aging, infections, diseases and genetic mutations, but the molecular mechanisms of these problems are largely unknown. Our overall hypotheses are that (1) the interplay of multiple specific protein components of otoconia and their embedding membrane determines their site-specific formation; (2) Otoconial protein homeostasis is essential to normal otoconia function; and (3) OC90, a major protein component of otoconia, is essential for the formation of otoconia by sequestering Ca. OC90 mutant mice will manifest a functional deficit of the inner ear, with the vestibule as the focus of this proposal. Specifically in this proposal, we will (1) identify other murine otoconial proteins and their cellular origin, to help identify factors that may contribute to otoconia formation. We will identify any interactions among OC90, otogelin, and other proteins in otoconia, its embedding membrane or the sensory epithelium by co-precipitation on PS10 protein chips to test hypothesis #1. (2) We will examine whether disrupted otoconin homeostasis caused the abnormal and malfunctioning otoconia in aging (C57BI/6J) and degenerating otoconia (head-tilt mice) by protein profiling on H4 chips, and examine changes in the deposition of otoconial proteins in embryos and newborn pups that have disrupted calcium homeostasis (tilt, PMCA-/- mice). (3) Then we will test hypothesis #3 by examining the spatial coordination of OC90 expression and Ca transportation, and by making two mutant mouse lines, one null and the other carting only one functional (PLA2L) domain, to study the role of OC90 in otoconia formation and gravity sensing, as well as in cochlea function. Combined with future sophisticated behavioral, physiological and gene/protein profiling studies, we will demonstrate the role of OC90 in bodily balancing, the molecular mechanisms of site-specific formation, regulation and proper maintenance of otoconia. Thus we will contribute to understanding inner ear development, function, physiology and pathology.

该子项目是利用 NIH/NCRR 资助的中心拨款提供的资源的众多研究子项目之一。子项目和研究者 (PI) 可能已从另一个 NIH 来源获得主要资金，因此可以在其他 CRISP 条目中出现。列出的机构是中心的机构，不一定是研究者的机构。 Otoconia（CaCO3 和蛋白质的微晶）是个体感知线性加速度和重力以进行空间定向和平衡控制所必需的。该系统的功能障碍是一个关键的临床问题，特别是在老年人中，但人们对调节耳锥生物合成的机制知之甚少。 Otoconia 似乎处于动态平衡状态，极易受到衰老、感染、疾病和基因突变的不利影响，但这些问题的分子机制在很大程度上尚不清楚。我们的总体假设是：（1）耳石的多种特定蛋白质成分及其包埋膜的相互作用决定了它们的位点特异性形成； (2)耳石蛋白质稳态对于正常耳石功能至关重要； (3) OC90是耳石的主要蛋白质成分，通过螯合Ca对于耳石的形成至关重要。 OC90 突变小鼠将表现出内耳功能缺陷，其中前庭是本提案的重点。具体来说，在本提案中，我们将 (1) 识别其他小鼠耳石蛋白及其细胞起源，以帮助识别可能有助于耳石形成的因素。我们将通过在 PS10 蛋白质芯片上进行共沉淀来鉴定 OC90、otogelin 和耳石、其包埋膜或感觉上皮中的其他蛋白质之间的任何相互作用，以检验假设 #1。 (2) 我们将通过H4芯片上的蛋白质分析来检查耳石蛋白稳态是否被破坏导致老化耳石症（C57BI/6J）和退化耳石症（歪头小鼠）的异常和功能障碍，并检查胚胎中耳石蛋白沉积的变化以及钙稳态被破坏的新生幼崽（倾斜，PMCA-/- 小鼠）。 (3) 然后，我们将通过检查 OC90 表达和 Ca2+ 运输的空间协调来检验假设#3，并通过制作两个突变小鼠系（一个无效，另一个仅携带一个功能 (PLA2L) 结构域）来研究 OC90 的作用耳石形成和重力感应以及耳蜗功能。结合未来复杂的行为、生理和基因/蛋白质分析研究，我们将展示 OC90 在身体平衡、耳石位点特异性形成、调节和正确维护的分子机制中的作用。因此，我们将有助于理解内耳的发育、功能、生理学和病理学。