Regulation of Actin Dynamics in Airway Smooth Muscle

气道平滑肌肌动蛋白动力学的调节

• 批准号: 7883463
• 负责人: Susan J. Gunst
• 金额: $ 38.5万
• 依托单位: INDIANA UNIV-PURDUE UNIV AT INDIANAPOLIS
• 依托单位国家: 美国
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-08-15 至 2012-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7883463
• 关键词: Actins; Actomyosin; Address; Adhesions; Agonist; Asthma; Binding; Biochemical; Breathing; Cell membrane; Cell model; Cells; Complex; Contracts; Coupled; Cultured Cells; Cytoskeletal Modeling; Cytoskeletal Proteins; Cytoskeleton; Development; Environmental air flow; Event; Extracellular Matrix; Family; G-Protein-Coupled Receptors; GTP-Binding Proteins; Generations; Goals; In Vitro; Integrins; Mechanics; Membrane; Microfilaments; Modeling; Molecular; Molecular Conformation; Multiprotein Complexes; Muscle; Muscle Cells; Muscle Contraction; Muscle strain; Myosin Light Chains; Phosphorylation; Physiological; Play; Process; Property; Protein Dephosphorylation; Proteins; Public Health; Recombinant Proteins; Regulation; Research; Role; Series; Shapes; Signal Pathway; Smooth Muscle; Smooth Muscle Actin Staining Method; Smooth Muscle Myocytes; Stimulus; Stretching; System; Therapeutic Agents; Therapeutic Intervention; Vinculin; airway hyperresponsiveness; cell type; cofilin; design; macromolecular assembly; member; new technology; new therapeutic target; novel; polymerization; protein complex; receptor; research study; respiratory smooth muscle; response; rho GTP-Binding Proteins; transmission process

DESCRIPTION (provided by applicant): Actin polymerization and remodeling of the actin cytoskeleton are critical steps in the process of tension generation in airway smooth muscle (ASM). In ASM, the actin cytoskeletal remodeling process is distinct from the actomyosin crossbridge cycling system, and may uniquely regulate specialized physiological properties of airway smooth muscle such as mechanical adaptation, which is critical for the regulation of airway tone when they are stretched during breathing. The long term goals of this project are to determine the molecular processes that regulate actin cytoskeletal remodeling in ASM, and to describe the mechanisms by which dynamic cytoskeletal events are coupled to contractile activation of the muscle by receptor agonists and external stimuli. Studies are proposed to address the hypothesis that vinculin and cofilin are key effectors in the regulation of cytoskeletal processes that determine the mechanical and contractile properties of airway smooth muscle, and that the activation states of these proteins are regulated by contractile and relaxing stimuli in ASM through the activation of Rho GTPases. Vinculin is proposed to act as a molecular switch for the regulation of connections between cytoskeletal actin filaments and membrane adhesion protein complexes. The formation of such connections may be critical for the regulation of tension transmission from the contractile apparatus to the extracellular matrix in smooth muscle. Cofilin is proposed to function to severe actin filaments and to generate the pool of G (monomeric) actin used for actin remodeling and polymerization. The specific aims of the project are: 1) Determine the role of vinculin in regulating connections between actin filaments and membrane adhesion complexes in ASM in response to agonists that regulate airway smooth muscle contractility. 2). Determine the role of cofilin in the remodeling of actin filaments by stimuli that regulate airway contractility, and evaluate the effects of the modulation of the actin remodeling on the static and dynamic mechanical properties of ASM. 3). Evaluate the mechanisms by which small Rho GTPases couple agonist stimulation to the regulation of cytoskeletal dynamics in ASM. These aims will be addressed in a series of experiments that take advantage of novel technology that enables the expression of endogenous and recombinant proteins to be manipulated in intact airway smooth muscle tissues and the effects on their physiologic, cellular and biochemical properties determined. The activation of these key cytoskeletal effector proteins may directly couple critical cytoskeletal processes to agonist stimulation in airway smooth muscle, thus they may constitute novel targets for therapeutic intervention in the treatment of abnormalities in the regulation of airway tone and responsiveness such as asthma. PROJECT NARRATIVE: The proposed experiments are directly relevant to public health. These studies will characterize novel fundamental mechanisms by which airway smooth muscle contractility and responsiveness is regulated under the normal conditions of breathing, and determine how physiologic agents that contract airway smooth muscle activate these processes. The studies will determine the function and regulation of key molecules that act to regulate airway smooth muscle responsiveness through theses novel mechanisms. This information is necessary for the design and development of appropriate therapeutic agents to treat asthma and airway hyperreactivity.

描述(由申请人提供)：肌动蛋白聚合和肌动蛋白细胞骨架的重塑是在气道平滑肌(ASM)产生张力的过程中的关键步骤。在ASM中，肌动蛋白的细胞骨架重塑过程不同于肌动蛋白跨桥循环系统，它可能独特地调节气道平滑肌的特殊生理特性，如机械适应，这对呼吸过程中伸展时的气道张力的调节至关重要。该项目的长期目标是确定调节ASM中肌动蛋白细胞骨架重构的分子过程，并描述动态细胞骨架事件与受体激动剂和外部刺激对肌肉的收缩激活相耦合的机制。有人提出这样一种假设，即纽蛋白和粘附素是细胞骨架过程中的关键效应者，细胞骨架过程决定了气道平滑肌的机械和收缩特性，并且这些蛋白的激活状态是通过激活Rho GTP酶来调节ASM中的收缩和松弛刺激的。纽蛋白被认为是调节细胞骨架肌动蛋白细丝和膜黏附蛋白复合体之间连接的分子开关。这种连接的形成对于调节从收缩装置到细胞外基质的张力传递可能是至关重要的。Cofilin被认为对严重的肌动蛋白细丝起作用，并产生用于肌动蛋白重塑和聚合的G(单体)肌动蛋白池。该项目的具体目标是：1)确定纽蛋白在ASM中调节肌动蛋白细丝和膜黏附复合体之间的连接中的作用，以响应调节气道平滑肌收缩的激动剂。2)。通过调节气道收缩的刺激，确定cofilin在肌动蛋白细丝重塑中的作用，并评估肌动蛋白重塑对ASM静态和动态力学性能的影响。3)。评估小Rho GTP酶结合激动剂刺激调节ASM细胞骨架动力学的机制。这些目标将通过一系列实验来实现，这些实验利用新技术使内源性和重组蛋白的表达能够在完整的气道平滑肌组织中进行操纵，并确定对其生理、细胞和生化特性的影响。这些关键的细胞骨架效应蛋白的激活可能直接将关键的细胞骨架过程偶联到气道平滑肌的激动剂刺激上，因此它们可能成为治疗哮喘等气道张力和反应性异常的治疗干预的新靶点。项目简介：拟议中的实验与公共卫生直接相关。这些研究将描述在正常呼吸条件下调节气道平滑肌收缩和反应性的新的基本机制，并确定收缩气道平滑肌的生理剂如何激活这些过程。这些研究将确定关键分子的功能和调节作用，这些分子通过这些新的机制调节气道平滑肌的反应性。这些信息对于设计和开发适当的治疗药物来治疗哮喘和呼吸道高反应性是必要的。