Maintenance and Disassembly of Olfactory Cilia

标题：嗅觉纤毛的维护和拆卸 这个项目的长期目标是确定纤毛在调节和维持嗅觉中的作用。 纤毛相关性疾病的功能及其改变。嗅觉障碍很常见，至少有16人受到影响 仅在美国就有数百万人。我们的实验室和其他实验室发现嗅觉功能障碍是一种临床表现 属于一种被称为纤毛病的人类遗传性疾病。Bardet-Biedl综合征(BBS)就是这样一种障碍， 嗅觉神经元纤毛形态的改变使细胞对气味没有反应。 尽管发现了许多纤毛疾病的潜在基因，但根治疗法(包括嗅觉疗法) 功能障碍)还不能提供给患者。我们报道了通过基因置换来恢复纤毛，从而 在有限数量的分化OSN中的感觉输入足以挽救周围气味反应 纤毛疾病子集的小鼠模型。然而，为了更好地了解嗅觉系统中的纤毛生物学和 发展潜在的治疗方法，我们必须定义潜在的嗅觉外显的细胞机制 纤毛病。我们还必须确定这些机制是否在不同的纤毛疾病中是保守的。 因此可能会受到同样的治疗策略的影响。OSN纤毛将所有必要的 用于气味检测的信号机制，即使OSN纤毛可能在生理和 病理条件，维持这一重要OSN细胞完整性的细胞机制 车厢内的情况仍然知之甚少。其他细胞和生物体中的纤毛在其 碱基，称为过渡区(TZ)，起着调节门的作用，控制独特的蛋白质和脂肪 纤毛的组成。令人惊讶的是，人们对OSN中的TZ知之甚少。这项拨款申请将阐明 OSN纤毛TZ的组成和亚细胞组织以及异常蛋白和脂质转位 纤毛的分解有助于纤毛的分解。我们的初步数据显示细胞内的变化 Ca~(2+)通过破坏TZ组分促进纤毛分解。我们假设持续的海拔高度 细胞内钙离子导致OSN纤毛TZ重塑，使纤毛膜脂发生改变 纤毛的分布和肌动蛋白的渗透是纤毛解体所必需的。因此， 我们提出以下具体目标：(1)确定OSN纤毛TZ的组成和组织 纤毛病变中伴随解体的改变；(2)确定细胞内钙离子升高对 OSN纤毛分解；(3)确定膜PIP2重分布和F-肌动蛋白在细胞中的作用 OSN纤毛分解的机制。这项工作的成功完成将提供至关重要的新见解 研究人类感觉性疾病的发病机制，是发展 治疗先天性嗅觉障碍和相关的由纤毛疾病引起的嗅觉功能障碍。

TITLE: Maintenance and Disassembly of Olfactory Cilia The long-term goal of this project is to determine the role of cilia in the regulation and maintenance of olfactory function and their alterations in cilia-related disorders. Olfactory dysfunction is common, affecting at least 16 million people in the U.S. alone. Our lab and others have found olfactory dysfunction to be a clinical manifestation of a class of human genetic disorders termed ciliopathies. Bardet-Biedl syndrome (BBS) is one such disorder, in which the altered cilia morphology of olfactory sensory neurons (OSNs) renders the cells unresponsive to odors. Despite the identification of numerous genes underlying ciliopathies, curative therapies (including for olfactory dysfunctions) are not yet available to patients. We reported that gene replacement to restore cilia and hence sensory input in a limited number of differentiated OSNs was sufficient to rescue peripheral odor responses in mouse models of a subset of ciliopathies. However, to better understand cilia biology in the olfactory system and advance potential therapies, we must define the cellular mechanisms underlying olfactory penetrance of ciliopathies. We must also determine whether these mechanisms are conserved across different ciliopathies and might thus be amenable to the same therapeutic strategies. OSN cilia compartmentalize all of necessary signaling machinery for odor detection and even though OSN cilia can be lost in both physiological and pathological conditions, the cellular mechanisms that maintain the integrity of this essential OSN cell compartment remain poorly understood. Cilia in other cells and organisms contain a multiprotein complex at its base, termed the transition zone (TZ), that functions as a regulatory gate to control the unique protein and lipid composition of cilia. Surprisingly little is known about the TZ in OSNs. This grant application will elucidate the composition and subcellular organization of the OSN cilia TZ and how aberrant protein and lipid translocation into cilia contributes to the disassembly of cilia. Our preliminary data suggest that alterations in intracellular Ca2+ contribute to cilia disassembly by disrupting TZ components. We hypothesize that sustained elevations of intracellular Ca2+ result in TZ remodeling of OSN cilia that is permissive for changes in cilia membrane lipid distribution and actin infiltration, both of which are necessary for cilia disassembly in ciliopathies. Therefore, we propose the following Specific Aims: (1) Determine the composition and organization of the OSN cilia TZ and alterations accompanying disassembly in ciliopathies; (2) Determine the effects of elevated intracellular Ca2+ on OSN cilia disassembly; (3) Determine the role of membrane PIP2 redistribution and F-actin infiltration in cellular mechanisms of OSN cilia disassembly. Successful completion of this work will provide critical new insights into the pathogenesis of human sensory perception diseases and is a necessary step for the development of treatments for congenital anosmia and related olfactory dysfunctions that result from ciliopathy.