LOCAL REGULATION OF AIRWAY SMOOTH MUSCLE TONE

气道平滑肌张力的局部调节

• 批准号: 6056615
• 负责人: CAROL A HIRSHMAN
• 金额: $ 28.23万
• 依托单位: COLUMBIA UNIVERSITY HEALTH SCIENCES
• 依托单位国家: 美国
• 财政年份: 1998
• 资助国家: 美国
• 起止时间: 1998-09-01 至 2002-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6056615
• 关键词: ADP ribosylation; G protein; actins; antisense nucleic acid; biological signal transduction; bronchomotion; calcium flux; fluorescence microscopy; guanine nucleotide binding protein; immunofluorescence technique; muscle contraction; paxillin; polymerase chain reaction; receptor coupling; receptor expression; respiratory pharmacology; smooth muscle; stimulant /agonist; swine; tissue /cell culture; transfection

Airway smooth muscle (ASM) contraction is a critical component in the pathophysiology of airway disease. Parasympathetic efferent nerves, mast cells, eosinophils and epithelial cells all release or synthesize substances that modify ASM tone. Although a rise in the intracellular calcium concentration is the normal trigger for smooth muscle contraction, agonist activation renders the myofilaments more sensitive to calcium (Ca2+) and potentiates Ca2+-induced contraction. Agonist activation, moreover, dynamically reorganizes the cytoskeleton. Preliminary studies for this proposal indicate that small G proteins (rho and ras) are important regulators of agonist-activated potentiation of Ca2+-induced contraction and cytoskeletal reorganization in ASM. However, the signaling pathways which link agonist activation via the heterotrimeric and small G proteins to cytoskeletal reorganization and potentiation of Ca2+-induced contraction in ASM are not well understood. Hence our overall goal is to determine how the signalling pathways transduced by the heterotrimeric G proteins, Gq and Gi, regulate the small G proteins, rho and ras, in ASM. We hypothesize that in ASM, activation of Gi is linked to rho, whereas activation of Gq is linked to ras. Using physiological, biochemical, and molecular techniques, we propose to: a) evaluate the signalling pathways by which activation of Gi and Gq induce rho- and ras-mediated potentiation of Ca2+-induced contraction in skinned porcine ASM, b) to identify the pathways by which Gq- and Gi-coupled receptor activation of rho increases formation of actin filaments and phosphorylation of paxillin in intact porcine ASM and cultured human ASM cells, and c) to examine the intermediate steps in the pathways linking Gi- and Gq-coupled receptors to ras and rho in cultured ASM. An understanding of signaling pathways in ASM regulating these novel Ca2+ independent processes that increase force production promises new targets and improved methods for the treatment of airway disease.

气道平滑肌（ASM）收缩是关键的组成部分 气道疾病的病理生理。 副交感神经，神经， 肥大细胞，嗜酸性粒细胞和上皮细胞均释放或合成 修改ASM音调的物质。 虽然细胞内增加 钙浓度是平滑肌的正常触发因素 收缩，激动剂激活使肌膜更敏感 到钙（Ca2+）并增强Ca2+诱导的收缩。 激动剂 此外，激活动态重组细胞骨架。 该提案的初步研究表明，小的G蛋白 （RHO和RAS）是激动剂激活增强的重要调节剂 ASM中Ca2+诱导的收缩和细胞骨架重组。 但是，通过将激动剂激活的信号通路通过 杂点和小的G蛋白，以进行细胞骨架重组和 ASM中Ca2+诱导的收缩的增强尚不清楚。 因此，我们的总体目标是确定信号通路如何 由异三聚体G蛋白GQ和GI转导的调节 ASM中的小G蛋白Rho和Ras。 我们假设在ASM中 GI的激活与RHO有关，而GQ的激活是链接的 到拉斯。 使用生理，生化和分子技术，我们 提议：a）评估激活的信号通路 GI和GQ诱导Ca2+诱导的Rho和Ras介导的增强 皮肤猪ASM的收缩，b）识别途径 RHO的GQ和GI偶联受体激活增加了形成的形成 肌动蛋白丝和完整猪中帕西林的磷酸化 和培养的人ASM细胞，c）检查中间步骤 在将GI-和GQ耦合受体与RAS和RHO连接的途径中 培养的ASM。 对ASM调节中信号通路的理解 这些新颖的CA2+独立过程增加了力产生 承诺新的目标和改进的气道治疗方法 疾病。