Gene delivery to muscle and nerve for laminin-alpha2-deficient MD (MDC1A)

描述(申请人提供)：先天性肌营养不良症(CMD)是一类目前无法治疗的严重遗传性神经肌肉疾病，影响肌肉和中枢神经系统(CNS)。层粘连蛋白-2(Merosin)缺陷型先天性肌营养不良症(MDC1A)是其中最常见的一种，每500,000名儿童中就有4名患有该病，并导致过早死亡。这项建议的目的是开发一种高效和非侵入性的基因传递方法，以跨越血脑屏障(BBB)进入中枢神经系统，除了肌肉和心脏。该方法将在带有迷你集聚蛋白基因的层粘连蛋白2基因敲除的dyw/dyw小鼠模型中进行测试，以取代失去的层粘连蛋白2的功能。先前我们表明，全身AAV1-迷你集聚蛋白注射显著改善了肌肉病理并延长了它们的寿命，但它未能传递到中枢神经系统以改善神经病理。最近我们发现，短暂性低温极大地增强了AAV进入脊髓和大脑的能力。我们还设计了具有更宽结合底物和更高亲和力的新嵌合迷你集聚蛋白基因。在进一步优化技术的同时，我们建议使用新的使能工具来测试我们的普遍假设，即改良的mini-agrin基因传递到肌肉、心脏和中枢神经系统将提供：1)更好和更广泛的肌肉和神经病理治疗益处；2)更大程度地改善dyw/dyw小鼠模型的生理功能和寿命。这项研究计划的成功可能对MDC1A患者和其他神经肌肉疾病具有潜在的可译性。

DESCRIPTION (provided by applicant): Congenital muscular dystrophy (CMD) is a class of currently untreatable, severe genetic neuromuscular disorders affecting muscle as well as the central nervous system (CNS). The laminin-¿2(merosin)-deficient congenital muscular dystrophy (MDC1A) is the most common of them, afflicts 4 in 500,000 children and causes premature death. The purpose of this proposal is to develop an efficient and non-invasive gene delivery method to cross the blood brain barrier (BBB) to the CNS, in addition to the muscle and heart. The method will be tested in a laminin ¿2-knockout dyw/dyw mouse model with a mini-agrin gene to replace the lost functions of laminin ¿2. Previously we showed that systemic AAV1-mini-agrin delivery greatly improved muscle pathology and extended their lifespan but it failed to deliver to the CNS for improvement of neurological pathology. Recently we found that transient hypothermia greatly enhances AAV delivery into the spinal cord and brain. We have also engineered new chimeric mini-agrin genes with broadened binding substrates and higher affinities. While further optimizing the technology, we propose to use the new enabling tools to test our general hypothesis that revamped mini-agrin gene delivery to muscle, heart and CNS will provide: 1) better and broader therapeutic benefits for muscle and nerve pathologies; and 2) greater improvement in physiological functions and lifespan of the dyw/dyw mouse model. The success of this research plan could be potentially translatable to MDC1A patients and to other neuromuscular diseases as well.