ACTA2, MYH11, and MYLK Mutations Affecting Smooth Muscle Contraction

ACTA2、MYH11 和 MYLK 突变影响平滑肌收缩

• 批准号: 8726464
• 负责人: JAMES T STULL
• 金额: $ 43.41万
• 依托单位: UNIVERSITY OF TEXAS HLTH SCI CTR HOUSTON
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/8726464
• 关键词: Actins; Adhesions; Affect; Agonist; Alleles; Aorta; Aortic Segment; Arteries; Attenuated; Biochemical; Biological; Blood Vessels; Cell Adhesion; Cell Proliferation; Cell-Matrix Junction; Cells; Clinical; Collagen; Contractile Proteins; Defect; Dermal; Development; Disease; Dissection; F-Actin; Fibroblasts; Filament; Focal Adhesions; Functional disorder; G Actin; Health; Human; Hypertension; In Vitro; Instruction; Knock-out; Lead; Light; Link; MYH11 gene; MYLK gene; Measurement; Mechanical Stress; Mesenteric Arteries; Microfilaments; Molecular; Molecular Motors; Mus; Muscle; Muscle Contraction; Mutate; Mutation; Myofibroblast; Myosin ATPase; Myosin Heavy Chains; Myosin Light Chain Kinase; Myosin Regulatory Light Chains; Output; Pathology; Pathway interactions; Patients; Performance; Phenotype; Phosphorylation; Process; Property; Protein Binding; Protein Isoforms; Proteins; Research; Research Project Grants; Resistance; Signal Transduction; Signaling Protein; Smooth Muscle; Smooth Muscle Actin Staining Method; Smooth Muscle Myocytes; Smooth Muscle Myosins; Testing; Thoracic Aortic Aneurysm; Tissues; Vascular Diseases; Vascular Smooth Muscle Tissue; Vasomotor; age related; ascending aorta; base; disease-causing mutation; factor A; insight; mutant; myocardin; novel; novel strategies; paxillin; polymerization; protein expression; response; transcription factor

Familial thoracic aortic aneurysms and dissection (TAAD) are linked to mutations in smooth muscle myosin heavy chain, actin and myosin light chain kinase (MLCK. We will test the overarching hypothesis that disease-causing mutations reduce smooth muscle contractile function. Aim 1: Test the hypothesis that MYH11 mutations that cause TAAD impair contractile output of smooth muscle cells. We will analyze aortic smooth muscle tissues from genetically modified mice for age-dependent adaptive changes in (1) expression of proteins in distinct adhiesion and contractile signaling modules, (2) [Ca2+]i and vasomotor performance in tissue rings in response to agonists, and (3) phosphorylation that activates the contractile myosin (RLC) or focal adhesion (paxillin) signaling modules. Aim 2: Test the hypothesis that heterozygous loss of MLCK activity impairs contractile output because of attenuated RLC phosphorylation in smooth muscle cells and leads to development of TAAD in the ascending aorta. Aim 3: Test the hypothesis that ACTA2 mutations that cause TAAD impair contractile output of smooth muscles. We will analyze the adhesion and contractile signaling modules as described in Aim 1 to determine if specific actin mutations promote selective dysfunction in one module or both. Aim 4: Test the hypothesis that ACTA2 mutations perturb myofibroblast contractions. MRTF-A will be used to induce myofibroblast phenotype expressing high amounts of smooth muscle a-actin in human dermal fibroblasts from patients harboring mutations in ACTA2. These studies will provide insights into the cellular basis of contractile performance defects associated with ACTA2 and MYH11 mutations examined at a molecular level in research Projects 1 and 2, and cellular pathways associated with reorganization of focal adhesions in mutant cells (Project 4). We also will continue collaborative studies on MLCK with Project 4.The synergy of our research interactions will provide an understanding of the molecular mechanisms that influence vascular disease based on the hypothesis that ACTA2, MYH11 and MYLK mutations lead to TAAD and occlusive vascular diseases due to selective dysfunctions of the contractile process. RELEVANCE (See instructions): We plan to establish the quantitative importance specific proteins responsible for the contractile responses of smooth muscle cells in blood vessels in health which may be deranged with mutations associated with TAAD. Characterization of key signaling proteins will provide perspectives on clinical strategies for novel pharmacological targets to manage TAAD, and potentially on cellular adaptations that may contribute to derangement of contractile responses involving smooth muscle in other vascular diseases.

家族性胸主动脉瘤和夹层 (TAAD) 与平滑肌突变有关 肌球蛋白重链、肌动蛋白和肌球蛋白轻链激酶 (MLCK)。我们将检验以下总体假设： 致病突变会降低平滑肌收缩功能。目标 1：检验假设 导致 TAAD 的 MYH11 突变会损害平滑肌细胞的收缩输出。我们将分析主动脉 来自转基因小鼠的平滑肌组织，其 (1) 表达存在年龄依赖性适应性变化 不同粘附和收缩信号模块中蛋白质的变化，(2) [Ca2+]i 和血管舒缩性能 组织环响应激动剂，以及（3）磷酸化，激活收缩肌球蛋白（RLC）或 粘着斑（桩蛋白）信号模块。目标 2：检验 MLCK 杂合缺失的假设 由于平滑肌细胞中 RLC 磷酸化减弱，活动会损害收缩输出， 导致升主动脉 TAAD 的发展。目标 3：检验 ACTA2 突变的假设 导致 TAAD 损害平滑肌的收缩输出。我们将分析粘附力和收缩力 信号模块如目标 1 中所述，以确定特定肌动蛋白突变是否促进选择性 一个或两个模块功能障碍。目标 4：检验 ACTA2 突变扰乱肌成纤维细胞的假设 宫缩。 MRTF-A 将用于诱导肌成纤维细胞表型表达大量平滑肌细胞 来自携带 ACTA2 突变的患者的人真皮成纤维细胞中的肌肉 a-肌动蛋白。 这些研究将深入了解相关收缩性能缺陷的细胞基础 研究项目 1 和 2 中在分子水平上检查了 ACTA2 和 MYH11 突变，以及细胞 与突变细胞粘着斑重组相关的途径（项目 4）。我们也将继续 与项目 4 进行 MLCK 合作研究。我们研究互动的协同作用将提供 基于以下假设了解影响血管疾病的分子机制 ACTA2、MYH11 和 MYLK 突变导致 TAAD 和选择性闭塞性血管疾病 收缩过程的功能障碍。 相关性（参见说明）： 我们计划确定负责收缩反应的特定蛋白质的定量重要性 健康血管中的平滑肌细胞可能因与以下疾病相关的突变而紊乱 TAAD。关键信号蛋白的表征将为新型药物的临床策略提供视角 管理 TAAD 的药理学目标，以及可能有助于细胞适应的药理学目标 其他血管疾病中涉及平滑肌的收缩反应紊乱。