Calcium Regulation in the Progression of Muscular Dystrophy

肌营养不良症进展中的钙调节

• 批准号: 7532263
• 负责人: Noah Weisleder
• 金额: $ 7.97万
• 依托单位: UNIV OF MED/DENT NJ-R W JOHNSON MED SCH
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-07-09 至 2013-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7532263
• 关键词: Actins; Address; Affect; Animal Model; Animals; Biological Assay; Breeding; Calcium; Cells; Characteristics; Code; Complex; Confocal Microscopy; Coupling; Cytoskeleton; Data; Defect; Development; Disruption; Duchenne muscular dystrophy; Dystroglycan; Dystrophin; Elevation; Epithelial Cells; Event; Extracellular Matrix; Extracellular Space; Fiber; Foundations; Generations; Genes; Goals; Hereditary Disease; Homeostasis; Image; In Vitro; Knowledge; Laminin; Link; Localized; Measurement; Mediating; Mediator of activation protein; Membrane; Mentors; Methods; Microscopic; Molecular; Muscle; Muscle Cells; Muscle Fibers; Muscular Dystrophies; Mutation; Myopathy; PLA2G6 gene; Pathology; Pathway interactions; Patients; Phase; Phenotype; Phospholipase; Phospholipase A2; Preparation; Regulation; Research; Research Personnel; Role; Sarcoplasmic Reticulum; Severities; Signal Transduction; Skeletal Muscle; Smooth Muscle; Stress; Striated Muscles; Structure; Testing; Training; United States; base; extracellular; human PLA2G6 protein; insight; link protein; mdx mouse; mouse model; patch clamp; programs; reagent testing; research study; response

DESCRIPTION (provided by applicant): Duchenne muscular dystrophy is a common genetic disorder resulting from mutations within the dystrophin gene. It is likely that the dystrophic phenotype does not result directly from alteration to the myofibrillar structures, rather it is a disruption of sarcolemmal membrane integrity that normally confers tight control of intracellular Ca homeostasis, which leads to elevated intracellular Ca and eventual muscle degeneration. The pathophysiological mechanism responsible for elevation of intracellular Ca levels is not clear, however our recent findings suggest that store-operated Ca entry (SOCE) linked to uncontrolled Ca spark activity may contribute to the aberrant Ca influx observed in dystrophic muscle. While the mechanism of SOCE activation is still a matter of intensive study, it has been recently determined that the Ca insensitive phospholipase A2 (iPLA2) is an important mediator of SOCE. The focus of this project is to test the hypothesis that aberrant Ca spark activity acts as a trigger for SOCE and thus induces a dystrophic cascade in mammalian skeletal muscle through a pathway that involves IPLA2 mediated signaling. We will test this with three specific aims: Aim 1: To establish induced Ca sparks as a trigger for SOCE in healthy and dystrophic muscle. We will utilize multiple methods for measurement of SOCE to examine alteration to Ca : entry in dystrophic fiber. Patch-clamp measurement and modulation of Ca influx will provide insight into SR Ca release and the activation of SOCE in dystrophic fibers. Aim 2: Determine the contribution of IPLA2 activity to Ca influx in muscular dystrophy. We will examine the altered characteristics of JPLA2 function in dystrophic muscle using various in vitro molecular and pharmacological methods. Aim 3: To elucidate if SOCE facilitates the dystrophic cascade in skeletal muscle. Due to the inability to assess changes in the dystrophic phenotype in skeletal muscle we will modulate SOCE in dystrophic animals and assay changes in dystrophic phenotypes. This project will contribute to our understanding of how muscle damage occurs in cases of Duchenne muscular dystrophy (DMD), the most common genetic disease in the United States. Our experiments will establish that defects in how calcium enters muscle cells result in the development of DMD. Such knowledge will suggest new methods to treat DMD, some of which will be tested on experimental animals in this study.

描述（由申请人提供）：杜氏肌营养不良症是一种常见的遗传性疾病，由肌营养不良蛋白基因突变引起。营养不良表型很可能不是直接由肌原纤维结构的改变引起的，而是肌膜完整性的破坏，而肌膜完整性通常对细胞内 Ca 稳态进行严格控制，从而导致细胞内 Ca 升高并最终导致肌肉退化。导致细胞内 Ca 水平升高的病理生理机制尚不清楚，但我们最近的研究结果表明，与不受控制的 Ca 火花活动相关的钙库操纵的 Ca 内流 (SOCE) 可能导致营养不良性肌肉中观察到的异常 Ca 流入。虽然 SOCE 激活机制仍然是一个深入研究的问题，但最近确定 Ca 不敏感磷脂酶 A2 (iPLA2) 是 SOCE 的重要介质。该项目的重点是测试以下假设：异常的 Ca 火花活动可作为 SOCE 的触发因素，从而通过涉及 IPLA2 介导的信号传导的途径诱导哺乳动物骨骼肌中的营养不良级联反应。我们将通过三个具体目标对此进行测试： 目标 1：建立诱导 Ca 火花作为健康和营养不良肌肉中 SOCE 的触发器。我们将利用多种 SOCE 测量方法来检查营养不良纤维中 Ca : 进入的变化。膜片钳测量和 Ca2+ 流入的调节将有助于深入了解营养不良纤维中 SR Ca2+ 的释放和 SOCE 的激活。目标 2：确定 IPLA2 活性对肌营养不良症中 Ca 内流的贡献。我们将使用各种体外分子和药理学方法检查营养不良性肌肉中 JPLA2 功能的改变特征。目标 3：阐明 SOCE 是否促进骨骼肌营养不良级联反应。由于无法评估骨骼肌营养不良表型的变化，我们将调节营养不良动物的 SOCE 并测定营养不良表型的变化。该项目将有助于我们了解杜氏肌营养不良症 (DMD)（美国最常见的遗传性疾病）中肌肉损伤是如何发生的。我们的实验将确定钙进入肌肉细胞的缺陷会导致 DMD 的发生。这些知识将提出治疗 D​​MD 的新方法，其中一些方法将在本研究中在实验动物上进行测试。