NEURONAL NICOTINIC RECEPTORS-EXPRESSION AND REGULATION

描述(摘自申请者摘要)：烟碱型乙酰胆碱受体 含有alpha7基因产物(alpha7-nAChRs)的是最丰富的 在神经系统中，并已被牵连到广泛的高级 大脑功能和神经退行性疾病。因为它们的钙含量很高 通透性和不同的位置，受体可以影响许多细胞 事件。目前的续期申请基于三项新发现： 受体可以通过细胞骨架的相互作用集中在体刺上 对于突触信号；受体功能可能基本上受到以下因素的限制 体内负调控；受体可影响基因表达 新奇的方式。这些发现形成了提出的四个具体目标。(1)识别 在突触部位系住α7-nAChRs的组件。(2)机制分析 控制α7-nAChRs的反应性。(3)评估 Alpha7-nAChR信号转导基因表达。(4)测试突触后的中枢神经系统模型 字母7-nAChRs。初步工作将在雏鸡睫状神经节上进行 因为它们提供了已知最丰富的受体来源。这个 神经元将在体内和细胞培养中进行检查，以确定细胞-细胞 支配体细胞脊椎的相互作用和受体相关分子 形成和α7-nAChR聚集性。外源成分显著增加 增加全细胞α7-nAChR反应将检查分子 机制和体内相关性。赋能的条件和机制 还将检测影响基因表达的α7-nAChR受体，以及 将确定受影响的基因家族，以检验关于 该效应的生理学相关性。富含中枢神经元的 然后将使用alpha7-nAChRs来确定哪些监管原则 控制睫状神经节受体可以跨系统广泛扩展 具有不同的生理任务。实验方法将 利用荧光成像、3-D断层扫描EM重建和全细胞 膜片钳原位和细胞培养记录。这些将与 生物化学和分子生物学方法用于鉴定和检测 影响受体功能和位置的分子，并确定哪些 受受体影响最大的是基因家族。所获得的信息将 说明大脑中的主要尼古丁受体是如何控制的，以及它是如何 转而，通过基因调控实施长期控制。生物医学 相关性是重大的，因为与健康相关的巨大后果 烟草使用和尼古丁成瘾，因为越来越多的证据表明 尤其是α7-nAChRs与神经退行性疾病有关，如 阿尔茨海默氏症对公众造成了毁灭性的损失。

DESCRIPTION (From applicant's abstract): Nicotinic acetylcholine receptors containing the alpha7 gene product (alpha7-nACHRs) are among the most abundant in the nervous system and have been implicated in a wide variety of higher brain functions and neurodegenerative diseases. Because of their high calcium permeability and diverse locations, the receptors can influence many cellular events. The present renewal application is based on three new discoveries: the receptors can be concentrated on somatic spines by cytoskeletal interactions for synaptic signaling; receptor function may be constrained substantially by negative regulation in vivo; and the receptors can influence gene expression in novel ways. These findings shape the four specific aims proposed. (1) Identify components that tether alpha7-nAChRs at synaptic sites. (2) Analyze mechanisms controlling the responsiveness of alpha7-nAChRs. (3) Assess the significance of alpha7-nAChR signaling for gene expression. (4) Test CNS models of postsynaptic alpha7-nAChRs. The initial work will be carried out with chick ciliary ganglion neurons because they provide the richest known source of the receptors. The neurons will be examined both in vivo and in cell culture to identify cell-cell interactions and receptor-associated molecules that govern somatic spine formation and alpha7-nAChR clustering. Exogenous components that dramatically increase the whole-cell alpha7-nAChR response will be examined for molecular mechanism and for in vivo relevance. The conditions and mechanisms enabling alpha7-nAChR receptors to influence gene expression will also be examined, and the gene families affected will be identified in order to test hypotheses about the physiological relevance of the effect. CNS neurons enriched in alpha7-nAChRs will then be used to determine which of the regulatory principles governing ciliary ganglion receptors can be extended broadly across systems having different physiological assignments. The experimental approaches will utilize fluorescence imaging, 3-D tomographic EM reconstruction, and whole-cell patch clamp recording in situ and in cell culture. These will be combined with biochemical and molecular biological approaches to identify and examine molecules influencing receptor function and location, and to determine which gene families are most affected by the receptors. The information obtained will indicate how a major nicotinic receptor in brain is controlled and how it, in turn, exerts long-term control through gene regulation. The biomedical relevance is substantial because of the enormous health-related consequences of tobacco usage and nicotine addiction and because of growing evidence that alpha7-nAChRs in particular are involved in neurodegenerative diseases such as Alzheimer's with a devastating toll on the public.