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

描述（由申请人提供）：先天性肌肉萎缩症（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）。其中最常见的是层粘连蛋白- 2（merosin）缺陷型先天性肌营养不良症（MDC1A），每50万名儿童中就有4人患病，并导致过早死亡。该提案的目的是开发一种高效且非侵入性的基因传递方法，以穿过血脑屏障（BBB）到达中枢神经系统，除了肌肉和心脏。该方法将在一个层粘连蛋白2敲除的dyw/dyw小鼠模型中进行测试，该模型带有一个mini-agrin基因来取代层粘连蛋白2失去的功能。先前我们发现，全身给药AAV1-mini-agrin可大大改善肌肉病理并延长其寿命，但不能给药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向脊髓和大脑的传递。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农用蛋白基因。在进一步优化技术的同时，我们建议使用新的启用工具来测试我们的一般假设，即改良的mini-agrin基因递送到肌肉、心脏和中枢神经系统将提供：1)对肌肉和神经病变更好、更广泛的治疗效果；2) dyw/dyw小鼠模型生理功能和寿命有较大改善。这项研究计划的成功可能潜在地转化为MDC1A患者和其他神经肌肉疾病。

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.