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）调节从肌浆网（SR）储存中释放Ca2+释放，并在人类中心核心疾病（CC​​D）和药物遗传学综合征中突变，恶性高温（MH）。尽管RYR1中的MH和CCD突变被认为会改变SR Ca2+释放通道功能和肌肉激发 - 收缩（EC）耦合，但这些作用导致这些疾病肌肉特征的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定义MH/CCD突变改变Ca2+稳态和激发 - 诱导（EC）耦合的细胞/分子机制和原理。我们的总体假设是：MH/CCD区域1和2中的MH和CCD突变通过改变RYR1和RYR1和RYR1之间的关键内部和分子间相互作用，从而增强电压 - 和Ca2+的SR释放。频道。 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从MH/CCD敲门小鼠获得的肌肉纤维，以及4）评估MH/CCD突变对RYR1配体激活的原位释放通道敏感性的影响，并在连接CA2+中局部增加。该应用程序汇集了两个合作者，他们高度致力于阐明MH和CCD病理生理学的基本机制，但他们以截然不同但互补的方式解决了问题。该联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，亚细胞CA2+运输/处理机制，肌肉EC耦合以及SR CA2+存储/续集/续集的机制。结果将对[应用中的截断]中Ca2+失调的其他疾病具有广泛的影响。