Gelsolin modulation of airway hyperresponsiveness and inflammation

项目总结/摘要 文献中有新的证据表明，不同类型的哮喘新配体可以急性 松弛气道平滑肌（ASM），尽管细胞内钙浓度短暂增加， 通常与收缩有关，而不是放松凝溶胶蛋白是钙激活的肌动蛋白， 解聚肌动蛋白细胞骨架导致ASM松弛的蛋白质。因此，凝溶胶蛋白的活化通过 短暂的细胞内钙升高可能是解释ASM松弛的统一机制 通过这些不同的配体。在这个建议中，我们提出了令人兴奋的初步数据，表明小鼠 遗传性缺乏凝溶胶蛋白在体外、离体和体内表现出ASM松弛受损。除了切断 肌动蛋白，细胞内凝溶胶蛋白具有磷脂酰肌醇4，5二磷酸（PIP 2）的结合结构域，其是 磷脂酶Cβ合成三磷酸肌醇（IP 3）的底物，是平滑肌的关键调节剂 钙的释放和收缩。我们将进一步证明，控制细胞内凝溶胶蛋白的表达和 激活是一种使用慢病毒介导的全长过表达的ASM细胞松弛的治疗策略， 凝溶胶蛋白和通过引入含有PIP 2结合结构域的短凝溶胶蛋白肽，其将 选择性地损害Gq介导的细胞内钙的增加。这一建议也证明了凝溶胶蛋白的作用 肺部炎症是哮喘的另一个重要病理特征。我们提出 为了证明肺巨噬细胞，其中凝溶胶蛋白被大量表达，可以是靶点， 变应性肺炎免疫调节我们将证明局部递送肽片段 减少气道平滑肌收缩和过敏性肺部炎症。 一个由成功的科学家和医生科学家组成的指导委员会将提供科学的 在研究计划的各个方面，包括离子通道生理学，钙信号，Th 2肺 炎症、肺免疫学和巨噬细胞生物学。一个全面的校内和校外计划 课程和培训由具有精确切割肺切片专业知识的其他合作者补充， 磁扭细胞仪将扩大研究培训和职业发展。研究课题 是气道平滑肌病理生理学和肺免疫领域独立研究的理想途径 过敏性肺炎的细胞生物学总的来说，K 08提案概述了一条强有力的途径， 科学的独立性和成功和持续的职业生涯作为一个物理学家科学家的基础。

Project Summary/Abstract There is emerging evidence in the literature that diverse classes of novel ligands for asthma can acutely relax airway smooth muscle (ASM) despite a transient increase in intracellular calcium concentrations, which has classically been associated with contraction, not relaxation. Gelsolin is a calcium-activated actin severing protein that depolymerizes the actin cytoskeleton leading to ASM relaxation. Thus, activation of gelsolin by transient intracellular calcium increases may be the unifying mechanism that would account for ASM relaxation by these diverse ligands. In this proposal, we present exciting preliminary data demonstrating that mice genetically lacking gelsolin exhibit impaired ASM relaxation in vitro, ex vivo and in vivo. In addition to severing actin, intracellular gelsolin has a binding domain for phosphatidylinositol 4,5 bisphosphate (PIP2), which is the substrate for phospholipase Cβ synthesis of inositol triphosphate (IP3), the critical regulator of smooth muscle calcium release and contraction. We will further demonstrate that controlling intracellular gelsolin expression and activation is a therapeutic strategy for ASM cell relaxation using lentiviral-mediated overexpression of full length gelsolin and by the introduction of a short gelsolin peptide containing the binding domain for PIP2, which would selectively impair Gq-mediated increases in intracellular calcium. This proposal also demonstrate gelsolin’s role in the development of lung inflammation, which is another key pathological characteristic in asthma. We propose to demonstrate that pulmonary macrophages, in which gelsolin is abundantly expressed, can be a target for immune modulation in allergic lung inflammation. We will demonstrate that local delivery of a peptide fragment of gelsolin decreases airway smooth muscle contraction and allergic lung inflammation. A mentoring committee composed of successful scientists and physician-scientists will provide scientific expertise in each aspect of the research plan including ion channel physiology, calcium signaling, Th2 lung inflammation, lung immunology and macrophage biology. A comprehensive plan of intramural and extramural coursework and training complemented by additional collaborators with expertise in precision cut lung slices and magnetic twisting cell cytometry will expand the research training and career development. The research topic is ideal for a path to independent research in areas of airway smooth muscle pathophysiology and lung immune cell biology in allergic lung inflammation. Taken as a whole, this K08 proposal outlines a robust pathway to scientific independence and the foundation of a successful and sustained career as a physician-scientist.