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）：Duchenne肌肉营养不良是由肌营养不良蛋白基因内突变引起的常见遗传疾病。营养不良的表型可能不会直接导致对肌原纤维结构的改变，而是肌膜膜完整性的破坏，通常会严格控制细胞内CA稳态，这会导致细胞内CA的升高和最终的肌肉变性。导致细胞内CA水平升高的病理生理机制尚不清楚，但是我们最近的发现表明，与不受控制的Ca Sparp活性相关的商店经营的CA进入（SOCE）可能有助于在营养不良肌肉中观察到的异常CA涌入。尽管SOCE激活的机制仍然是一项密集研究的问题，但最近已经确定CA不敏感的磷脂酶A2（IPLA2）是SOCE的重要介体。该项目的重点是检验以下假设：异常CA激素活性充当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营养不良的级联反应。我们将以三个特定的目的进行测试：目标1：建立诱导的CA火花，以触发健康和营养不良的肌肉。我们将利用多种方法来测量SOCE来检查对CA的变化：进入营养不良纤维中的进入。斑块夹的测量和调制CA涌入将为SR CA释放和营养不良纤维中SOCE的激活提供深入的了解。 AIM 2：确定IPLA2活性对CA涌入肌肉营养不良的贡献。我们将使用各种体外分子和药理学方法研究JPLA2功能在营养不良肌肉中的变化。目标3：阐明SOCE是否有助于骨骼肌中营养不良的级联反应。由于无法评估骨骼肌营养不良表型的变化，因此我们将调节营养不良的动物中的SOCE，并在营养不良表型中进行测定变化。该项目将有助于我们理解在美国最常见的遗传疾病Duchenne肌肉营养不良（DMD）的情况下如何发生肌肉损害。我们的实验将确定钙如何进入肌肉细胞的缺陷导致DMD的发展。这些知识将提出治疗DMD的新方法，其中一些方法将在本研究中对实验动物进行测试。