Basis of Muscle Dysfunction in Malignant Hyperthermia and Central Core Disease

恶性高热和中央核心疾病中肌肉功能障碍的基础

• 批准号: 7215722
• 负责人: SUSAN L HAMILTON
• 金额: $ 36.72万
• 依托单位: BAYLOR COLLEGE OF MEDICINE
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-04-01 至 2011-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7215722
• 关键词: 5' -adenylyl (beta,gamma-methylene)diphosphonate; Adult; Affinity; Aging; Amino Acids; Anesthetics; Binding; Birth; Caffeine; Central Core Myopathy; Characteristics; Commit; Coupling; Cresol; Cresols; Cryoelectron Microscopy; Cytoplasm; Dependence; Dihydropyridine Receptors; Disease; Elevation; Embryo; Exercise; Fiber; Figs - dietary; Flexor; Functional disorder; Gifts; Goals; Heating; Homeostasis; Human; In Situ; Isoflurane; Knock-in Mouse; Knock-out; Label; Laboratories; Lead; Left; Ligands; Lipid Bilayers; Malignant hyperpyrexia due to anesthesia; Maps; Membrane; Molecular; Mus; Muscle; Muscle Fibers; Muscle function; Mutant Strains Mice; Mutate; Mutation; Numbers; Partner in relationship; Permeability; Pharmacogenetics; Property; Proteins; Rate; Regulation; Research Personnel; Resolution; Respiratory Diaphragm; Respiratory Failure; Rest; RyR1; RyR3; Ryanodine; Ryanodine Receptor Calcium Release Channel; Sarcoplasmic Reticulum; Skeletal Muscle; Skeletal system; Structure; Surface; Syndrome; Temperature; Testing; Thinking; Transgenic Organisms; Variant; Wild Type Mouse; base; day; disease-causing mutation; embryonic stem cell; image reconstruction; improved; in vivo; intermolecular interaction; knockout animal; mutant; novel; programs; reconstitution; reconstruction; response; three dimensional structure; voltage

DESCRIPTION (provided by applicant): The skeletal muscle ryanodine receptor (RYR1) regulates Ca2+ release from the sarcoplasmic reticulum (SR) stores and is mutated in human central core disease (CCD) and in the pharmacogenetic syndrome, malignant hyperthermia (MH). Although MH and CCD mutations in RyR1 are thought to alter SR Ca2+ release channel function and muscle excitation-contraction (EC) coupling, the mechanisms by which these effects result in phenotypic changes in muscle characteristic of these disorders are unknown. This project will use transgenic MH and CCD knock-in mice to provide detailed analyses of the fundamental mechanisms by which RYR1 disease mutations alter in vivo muscle function. The long-term goal of this project is to define the cellular/molecular mechanisms and principles by which MH/CCD mutations alter Ca2+ homeostasis and excitation-contraction (EC) coupling in intact muscle. Our overall hypothesis is: MH and CCD mutations in MH/CCD regions 1 and 2 enhance voltage- and Ca2+-gated SR release by altering crucial intra and intermolecular interactions within RYR1 and between RYR1 and the voltage dependent Ca2+ channel in the t-tubule membrane, while CCD-selective mutations in the region 3 pore region of RyR1 disrupt Ca2+ permeation through the channel. To test this hypothesis, we propose to: 1) Create three new MH/CCD mouse lines and analyze the effects of the mutations on muscle contractile properties in response to caffeine and temperature, 2) Analyze the effects of the mutations on RYR1 structure, 3) Assess the effects of MH/CCD mutations in RyR1 on Ca2+ homeostasis and bi-directional DHPR-RyR1 coupling in myotubes and adult muscle fibers obtained from MH/CCD knock-in mice, and 4) Evaluate the effects of MH/CCD mutations on in situ release channel sensitivity to activation by RyR1 ligands and local increases in junctional Ca2+. This application brings together two collaborators, both highly committed to elucidating fundamental mechanisms of MH and CCD pathophysiology, but who approach the problems in very different, but complementary ways. This union will result in a uniquely interdisciplinary project that will determine the mechanisms by which MH/CCD disease mutations alter RyR1 structure and regulation, subcellular Ca2+ transport/handling mechanisms, muscle EC coupling, and SR Ca2+ storage/sequestration. Results will have broad implications for other disorders of Ca2+ dysregulation in [truncated in application]

描述（由申请人提供）：骨骼肌ryanodine受体（RYR1）调节肌浆网（SR）储存的Ca2+释放，并在人类中央核心疾病（CCD）和药物遗传综合征恶性高热（MH）中发生突变。尽管人们认为RyR1中的MH和CCD突变会改变SR Ca2+释放通道功能和肌肉兴奋-收缩（EC）耦合，但这些影响导致这些疾病肌肉特征表型变化的机制尚不清楚。该项目将使用转基因MH和CCD敲入小鼠，对RYR1疾病突变改变体内肌肉功能的基本机制进行详细分析。该项目的长期目标是确定MH/CCD突变改变完整肌肉中Ca2+稳态和兴奋-收缩（EC）偶联的细胞/分子机制和原理。我们的总体假设是：MH/CCD区1和2的MH和CCD突变通过改变RYR1内和RYR1与t小管膜中电压依赖性Ca2+通道之间的关键分子内和分子间相互作用来增强电压和Ca2+门控SR释放，而RYR1区3孔区的CCD选择性突变破坏Ca2+通过通道的渗透。为了验证这一假设，我们建议：1)建立3个新的MH/CCD小鼠品系，分析突变对咖啡因和温度下肌肉收缩特性的影响；2)分析突变对RYR1结构的影响；3)评估MH/CCD敲入小鼠的RYR1中MH/CCD突变对肌管和成年肌纤维中Ca2+稳态和DHPR-RyR1双向偶联的影响。4)评估MH/CCD突变对原位释放通道对RyR1配体激活的敏感性和局部连接Ca2+增加的影响。该应用程序汇集了两位合作者，他们都高度致力于阐明MH和CCD病理生理的基本机制，但他们以非常不同但互补的方式解决问题。这种结合将导致一个独特的跨学科项目，该项目将确定MH/CCD疾病突变改变RyR1结构和调控的机制，亚细胞Ca2+运输/处理机制，肌肉EC耦合和SR Ca2+存储/封存。结果将对Ca2+失调的其他疾病具有广泛的意义[应用截断]