Brain-targeted delivery of therapeutic molecules by exosomes derived from engineered human iPS cells: a potential therapeutic approach for Huntington's disease

项目摘要 亨廷顿氏病（HD）是一种破坏性的神经退行性疾病，由CAG重复扩增引起， 亨廷顿基因（HTT）。CAG重复序列在突变HTT中被翻译成多聚谷氨酰胺（polyQ）序列 具有神经毒性的蛋白质。目前的治疗努力集中在抑制 突变HTT蛋白或靶向神经毒性的下游途径。我们和其他人已经证明， 重复靶向的磷酰二胺吗啉寡聚物（PMO）和神经营养蛋白BDNF具有 HD的治疗益处。然而，PMO和BDNF通常不穿过血脑屏障（BBB）， 阻碍了临床应用的转化。因此，更有效的运载工具能够BBB 渗透对于开发HD和其他神经退行性疾病的有效疗法至关重要 梗概.外泌体（Exosomes，Exo）是具有BBB穿透潜力的细胞分泌的细胞外载体，能够 递送外源性治疗分子。iPSC被认为是Exo的最佳来源之一。 生产，基于高Exo产量，cGMP兼容的临床级生产平台的可用性， iPSC生产和Exo制造，以及进行基因组编辑以建立工程化iPSC的可行性 生产改良的Exo以更有效地瞄准大脑。因此，我们建议制定战略， 从工程化的iPSC产生脑靶向Exo作为PMO以及BDNF的递送载体，并且进一步 在一个小组中严格研究载有PMO和BDNF的脑靶向Exo的治疗效果， HD神经元和小鼠模型。该项目的成功将为未来更大规模的调查奠定基础 目的是使用人iPSC衍生的Exo用于靶向递送治疗性分子（例如PM0、化学物质、药物组合物、药物组合物）， 化合物和神经营养因子）用于各种神经变性病症。

PROJECT SUMMARY Huntington’s disease (HD) is a devastating neurodegenerative disease caused by a CAG repeat expansion in the gene huntingtin (HTT). The CAG repeat is translated into a polyglutamine (polyQ) tract in the mutant HTT protein that has neurotoxic properties. Current therapeutic efforts are focused at suppressing the expression of the mutant HTT protein or targeting downstream pathways of neurotoxicity. We and others have shown that CAG repeat-targeting phosphorodiamidate morpholino oligomers (PMOs) and neurotrophic protein BDNF have therapeutic benefits for HD. However, PMOs and BDNF do not usually cross the blood-brain barrier (BBB), hindering the translation of clinical application. Therefore, more efficient delivery vehicles capable of BBB penetration are critical for the development of effective therapies for HD and other neurodegenerative disorders in general. Exosomes (Exo) are cell-secreted extracellular vehicles with BBB penetration potential, capable of delivering exogeneous therapeutic molecules. iPSCs have been considered as one of the best sources for Exo manufacture, based on high Exo yield, availability of cGMP-compatible clinical-grade manufacture platform for iPSC production and Exo manufacture, and feasibility to perform genome editing to establish engineered iPSCs that produce modified Exo for more efficient brain targeting. We therefore propose to develop strategies to produce brain-targeting Exo from engineered iPSCs as delivery vehicles for PMOs as well as BDNF, and further rigorously study the therapeutic efficacy of the brain-targeting Exo loaded with PMOs and BDNF in a panel of HD neuron and mouse models. Success of this project will set the stage for future larger scale investigations aimed at using huma iPSC-derived Exo for targeted delivery of therapeutic molecules (such as PMOs, chemical compounds and neurotrophic factors) for various neurodegenerative disorders.