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

描述（由申请人提供）：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（MDC 1A）是其中最常见的，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有效且非侵入性的基因递送方法，以穿过血脑屏障（BBB）到达CNS，以及肌肉和心脏。该方法将在层粘连蛋白2敲除dyw/dyw小鼠模型中进行测试，该模型具有微型聚集蛋白基因以取代层粘连蛋白2的丧失功能。先前我们表明，全身性AAV 1-微型聚集蛋白递送极大地改善了肌肉病理学并延长了它们的寿命，但它未能递送至CNS以改善神经病理学。最近，我们发现短暂低温大大增强了AAV递送到脊髓和脑中。我们还设计了新的嵌合微聚集蛋白基因，具有更宽的结合底物和更高的亲和力。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一般假设，即改进的微聚集蛋白基因递送到肌肉、心脏和CNS将提供：1）对肌肉和神经病理的更好和更广泛的治疗益处;以及2）在dyw/dyw小鼠模型的生理功能和寿命方面的更大改善。这项研究计划的成功可能也适用于MDC 1A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.