Preclinical Development of a Novel Therapeutic Strategy for LGMD2B

描述(由申请人提供)：这项建议的长期目标是促进我们对目前无法治愈的2B型肢体Girdle肌营养不良症(LGMD2B)的新治疗策略的临床前开发。肌营养不良是一种肌肉萎缩的疾病，发病率和死亡率都会增加。LGMD2B是由功能障碍蛋白基因突变导致蛋白表达改变(功能障碍病)引起的。有研究表明，通过依赖于干扰素的膜融合修复受损的膜是有缺陷的。然而，我们对deferlin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)的循环和神经肌肉接头-NMJ处突触传递的维持)的了解中存在漏洞。利用LGMD2B线虫模型中可用的强大药物遗传学工具，我们已经确定了FER-1在NMJ突触传递调节中的新角色(初步研究)。我们对突触病态或肌无力成分的识别具有巨大的病因学和翻译意义。有趣的是，乙酰胆碱酯酶抑制剂(AChEI)的应用改善了A/J小鼠模型LGMD2B的存活率(初步研究)，并提出了一种假设，即由去铁蛋白缺乏引起的NMJ缺陷可以通过使用AChEI作为候选治疗方法来治疗，以提高神经肌肉传递的效率和改善LGMD2B的结果。作为一个特定的目标，我们提出了一项精心设计的原则证明研究，以完成成功开发这一候选治疗性药物所需的初步步骤，并测试我们的翻译假设。我们将进行一项治疗试验，用AChEI治疗8月龄A/J小鼠8个月。治疗潜力将采用体内和体外方法进行分析，以确定营养不良表型的改善。这个项目的相关性和与健康相关的是，进行这些研究，我们将确保更清楚地了解分子和功能病理生理学，并促进我们对LGMD2B的新治疗策略的临床前开发。 公共卫生相关性：该项目的健康相关性在于，通过完成我们的目标，我们将确保更清楚地了解2B型肢体带状肌营养不良症(LGMD2B)的分子和功能病理生理学，并促进我们针对LGMD2B的新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.