MG53-Mediated Membrane Repair in Muscle Physiology and Disease

MG53 介导的肌肉生理学和疾病中的膜修复

• 批准号: 8545523
• 负责人: Jianjie Ma
• 金额: $ 32.83万
• 依托单位: OHIO STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-09-16 至 2016-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8545523
• 关键词: Acute; Affect; Animal Model; Binding; Biochemical; Biochemical Markers; Biological Process; Caveolae; Cell membrane; Cell physiology; Cells; Cholesterol; DYSF gene; Data; Defect; Degenerative Disorder; Disease; Docking; Familial generalized lipodystrophy; Functional disorder; Gene Mutation; Goals; Human; Injury; Knock-out; Life; Link; Lipodystrophy; Mediating; Membrane; Modeling; Molecular; Mus; Muscle; Muscle Cells; Muscle Fibers; Muscular Dystrophies; Mutation; Natural regeneration; Paper; Physiological; Physiology; Polymerase; Prevention; Process; Proteins; Publishing; RNA Interference; Recovery; Regenerative Medicine; Regulation; Research Design; Role; Signal Transduction; Site; Skeletal Muscle; Structure; TRIM Family; Testing; Therapeutic Agents; Transcript; Transgenic Organisms; Translating; base; caveolin-3; cell injury; cellular imaging; genetic manipulation; human disease; improved; in vivo; injured; membrane assembly; muscular dystrophy mouse model; novel; novel therapeutic intervention; overexpression; reconstruction; release factor; repaired; research and development; research study; response; restoration; sensor

DESCRIPTION (provided by applicant): Repair of acute damage to the plasma membrane is an important aspect of normal cellular physiology and disruption of this process can result in pathophysiology in a number of human diseases including muscular dystrophy. We recently discovered that MG53, a muscle-specific TRIM-family protein, is an essential component of the membrane repair machinery. While our published data define the sensor function for MG53 in cell membrane repair, the molecular mechanisms underlying the nucleation process remain to be defined. Since MG53 can discriminate between intact and injured membrane, a membrane-delimited signal would likely be involved in tethering of MG53 to the injured site. In pilot studie, we found that PTRF is an obligatory factor for MG53-mediated nucleation of the membrane repair response, for cells lacking endogenous expression of PTRF show defective membrane resealing. While RNAi- silencing of PTRF leads to defective membrane repair in muscle fibers, overexpression of PTRF can rescue this defect in dysferlin-/- muscle but not in mg53-/- muscle, suggesting that the functional role of PTRF in membrane repair likely requires the presence of MG53. While many studies have explored the function of PTRF in regulating caveolae structure of the plasma membrane, our data present a new biological function for PTRF as an anchoring molecule for MG53 for initiation of the cell membrane repair response. Since mutations in PTRF have been identified in human disorders with lipodystrophy and muscular dystrophy, conditions that often involve compromised membrane integrity or resealing capacity, targeting the functional interaction between MG53 and PTRF, or restoration of the disrupted MG53-PTRF interaction in the diseased states, may represent an attractive avenue for treatment or prevention of degenerative diseases involving compromised membrane repair. The long-term goal of this project is to understand the cellular and molecular mechanism for membrane repair in muscle physiology and diseases. Specifically, we will focus on testing the hypothesis that "PTRF acts as a docking protein for MG53-mediated cell membrane repair, and restoration of membrane integrity in muscular dystrophy can be achieved through enhancement of MG53/PTRF function at the interface of membrane injury". Our proposed studies will focus on defining the molecular mechanism underlying the functional interaction between MG53 and PTRF for initiation of the cell membrane repair response in skeletal muscle (Aim 1); and exploring the physiological role of MG53 and PTRF in muscle physiology and diseases and test if enhancement of PTRF-MG53 function can improve membrane integrity in muscular dystrophy (Aim 2). Through tailored-expression of MG53 and PTRF and the use of biochemical markers, live cell imaging, ex vivo and in vivo animal model studies, the designed experiments will provide key proof-of-principle data for targeting MG53/PTRF-mediated cell membrane repair in treatment of muscular dystrophy.

描述（由申请人提供）：对质膜的急性损害修复是正常细胞生理学的重要方面，并且对此过程的破坏可能导致许多人类疾病在内的许多人类疾病，包括肌肉营养不良。我们最近发现，MG53是一种肌肉特异性的修剪蛋白，是膜修复机械的重要组成部分。尽管我们已发布的数据定义了MG53在细胞膜修复中的传感器函数，但成核过程的分子机制仍有待定义。由于MG53可以区分完整的膜和受伤的膜，因此可能会涉及将MG53绑定到受伤部位的信号。在Pilot Studie中，我们发现PTRF是MG53介导的膜修复响应成核的强制性因素，因为缺乏内源性PTRF的细胞表现出膜重新密封的缺陷。虽然PTRF的RNAi-Silencing导致肌肉纤维的膜修复有缺陷，但PTRF的过表达可以挽救Dysferlin - / - 肌肉中的这种缺陷，但在MG53 - / - 肌肉中不能挽救这种缺陷，这表明PTRF在膜修复中的功能作用可能需要MG53的存在。尽管许多研究探索了PTRF在调节质膜小窝结构中的功能，但我们的数据介绍了PTRF作为MG53的锚定分子的新生物学功能，用于启动细胞膜修复响应。 Since mutations in PTRF have been identified in human disorders with lipodystrophy and muscular dystrophy, conditions that often involve compromised membrane integrity or resealing capacity, targeting the functional interaction between MG53 and PTRF, or restoration of the disrupted MG53-PTRF interaction in the diseased states, may represent an attractive avenue for treatment or prevention of degenerative diseases involving compromised膜修复。该项目的长期目标是了解肌肉生理和疾病中膜修复的细胞和分子机制。具体而言，我们将重点介绍以下假设：“ PTRF充当MG53介导的细胞膜修复的对接蛋白，并且可以通过在膜损伤界面上增强MG53/PTRF功能来实现肌肉营养不良中膜完整性的恢复。我们提出的研究将着重于定义MG53和PTRF之间功能相互作用的分子机制，以启动骨骼肌中细胞膜修复反应的启动（AIM 1）；并探索MG53和PTRF在肌肉生理和疾病中的生理作用，并测试PTRF-MG53功能的增强是否可以改善肌肉营养不良中的膜完整性（AIM 2）。通过对MG53和PTRF的量身定制表达，以及生化标记，活细胞成像，EX VIVO和体内动物模型研究的使用，设计的实验将为靶向MG53/PTRF介导的细胞膜修复的关键原则数据，以治疗肌肉发育不全。