Preclinical Development of a Novel Therapeutic Strategy for LGMD2B

描述（由申请人提供）：该提案的长期目标是促进我们针对目前无法治愈的 2B 型肢带肌营养不良症 (LGMD2B) 的新型治疗策略的临床前开发。肌营养不良症是发病率和死亡率增加的肌肉消耗性疾病。 LGMD2B 是由 Dysferlin 基因突变导致蛋白质表达改变（Dysferlin 病）引起的。与通过 Dysferlin 依赖性膜融合对受损膜的修复不足有关。然而，我们对 Dysferlin 是否调节众所周知的囊泡融合相关过程（例如乙酰胆碱受体 (AChR) 回收和神经肌肉接头突触传递的维持 -NMJ）的了解存在空白。利用 LGMD2B 线虫模型中可用的强大药物遗传学工具，我们发现了 fer-1 在 NMJ 突触传递调节中的新作用（初步研究）。我们对突触病或肌无力成分的识别具有巨大的疾病分类学和转化意义。有趣的是，在一项小型试点试验（初步研究）中，乙酰胆碱酯酶抑制剂（AChEI）的施用提高了 LGMD2B A/J 小鼠模型的存活率，并提出了这样的假设：由 Dysferlin 缺乏引起的 NMJ 缺陷适合使用 AChEI 作为候选疗法进行治疗，以提高神经肌肉传递的效率并改善 LGMD2B 的结果。作为一个具体目标，我们提出了一项精心设计的原理验证研究，以完成该候选疗法成功临床前开发所需的初步步骤，并测试我们的转化假设。我们将进行一项治疗试验，用 AChEI 治疗 8 个月大的 A/J 小鼠 8 个月。将使用体内和离体方法测定治疗潜力以确定营养不良表型的改善。该项目的相关性和健康相关性在于，进行这些研究将确保我们更清楚地了解分子和功能病理生理学，并促进 LGMD2B 新型治疗策略的临床前开发。 公共健康相关性：该项目与健康的相关性在于，通过完成我们的目标，我们将确保更清楚地了解 2B 型肢带型肌营养不良症 (LGMD2B) 的分子和功能病理生理学，并促进 LGMD2B 新型治疗策略的临床前开发。

DESCRIPTION (provided by applicant): The long term goals of this proposal are to facilitate preclinical development of our novel therapeutic strategy for the currently incurable Limb Girdle Muscular Dystrophy Type 2B (LGMD2B). The muscular dystrophies are muscle wasting disorders with increased morbidity and mortality. LGMD2B is caused by dysferlin gene mutations leading to altered protein expression (dysferlinopathy). Deficient repair of damaged membranes via dysferlin-dependent membrane fusion has been implicated. However, lacunae exist in our knowledge of whether dysferlin regulates well-known vesicle fusion related processes (e.g. Acetylcholine Receptor (AChR) recycling & maintenance of synaptic transmission at the neuromuscular junction-NMJ). Using powerful pharmacogenetic tools available in the C. elegans model of LGMD2B, we have identified a novel role for fer-1 in the regulation of NMJ synaptic transmission (Preliminary studies). Our identification of a synaptopathic or myasthenic component has tremendous nosological and translational implications. Interestingly, Acetylcholine Esterase Inhibitors (AChEI) administration improves the survival of the A/J mouse model of LGMD2B in a small pilot trial (Preliminary Studies) and suggests the hypothesis that the NMJ deficit caused by dysferlin deficiency is amenable to treatment using AChEI as a candidate therapeutic to increase the efficiency of neuromuscular transmission and improve LGMD2B outcomes. As a specific aim we propose a well-designed, proof-of-principle study in order to complete the preliminary steps required for successful preclinical development of this candidate therapeutic and test our translational hypothesis. We will undertake a therapeutic trial where we treat 8 month old A/J mice with AChEI for 8 months. Therapeutic potential will be will be assayed using in vivo and ex vivo means to determine improvement of the dystrophic phenotype. The relevance and health relatedness of this project is that undertaking these studies we will ensure clearer understanding of the molecular and functional patho-physiology as well as facilitate preclinical development of our novel therapeutic strategy for LGMD2B. PUBLIC HEALTH RELEVANCE: The health relatedness of this project is that by completion of our aim we will ensure clearer understanding of the molecular and functional patho-physiology of limb-girdle muscular dystrophy Type 2B (LGMD2B) as well as facilitate preclinical development of our novel therapeutic strategy for LGMD2B.