Exosome based therapeutics in Huntington's disease

描述（由申请人提供）：该UH2和UH3的目标是研究外泌体如何通过血脑屏障递送sirna进入神经元和其他脑细胞。直接的目标是突变的亨廷顿蛋白mRNA。亨廷顿氏病（HD）是由CAG三核苷酸重复序列增加到¿36序列引起的；这需要在高水平的护理机构呆上几年因为神经退化首先是纹状体和皮层，然后是其他大脑结构。HD患者有认知障碍、抑郁和运动异常。大多数HD患者出现在30 - 40岁；少数有青少年发病。合理的治疗方法是降低突变huntingtinmrna的表达；这种治疗可以在HD小鼠模型中通过siRNA、反义寡核苷酸（ASO）和腺相关病毒（AAV）与shRNAmir靶向亨廷顿mRNA来实现。然而，输送仍然是治疗方法实际实施的一个陷阱。siRNA和ASO需要长期输注。在非人灵长类动物中，给予脊髓液的ASO不能到达纹状体，siRNA在大脑中的传播受到限制。尽管前景看好，但AAV-shRNA需要多次注射到大脑区域，而且shRNAmir是不受管制的。HD疗法的空白可以由通常由细胞、外泌体挤出的微泡填充。表面带有狂犬病毒糖蛋白（RVG）的外泌体可以注射到血液中，穿过血脑屏障，进入神经元和神经胶质。rvg -外泌体可以携带siRNA货物。外泌体进入血液循环后，将siRNA沉积在神经元中进行RNA干扰。我们的目的是开发外泌体作为HD的治疗方法。UH2检测rvg -外泌体携带siRNA对抗亨廷顿蛋白mRNA穿越血脑屏障进入神经元的能力。在脑定位和RNAi依赖性敲除将被研究。将寻找功能强大的sirna。由于外泌体是由细胞质组成的，因此外泌体mRNA、miRNA和嵌入的siRNA将通过深度测序进行鉴定。免疫反应性和免疫中和将被研究，因为外泌体具有潜在的抗原，如RVG，并且需要经常给药。UH3通过研究逆转或预防HD小鼠模型的神经病理和异常运动，进一步建立了基于外泌体的治疗方法。外泌体的剂量将得到保证。一个由HD发病机制、siRNA开发、RNA鉴定和测量、RNAi机制以及外泌体产生和脑递送方面的专家组成的团队将进行研究。利用外泌体进行脑输送有望形成一种可行的治疗方法，以减少亨廷顿舞蹈症患者突变亨廷顿蛋白的表达。患有其他遗传性神经退行性疾病的患者也会受益。

DESCRIPTION (provided by applicant): The goal of this UH2 and UH3 is to study how exosomes can deliver siRNAs across the blood brain barrier to enter neurons and other brain cells. The immediate target is the mutant huntingtin mRNA. Huntington's disease (HD) is caused by an increase in the CAG trinucleotide repeats to ¿ 36 in series; it necessitates years in a high level nursing facility because of neurodegeneration first in striatum and cortex and then to other brain structures. HD patients have cognitive impairment, depression and aberrant movements. Most HD patient present by 30 to 40 years of age; a few have a juvenile onset. A rational treatment is to decrease expression of mutant huntingtin mRNA; this therapeutic can be accomplished in HD mouse models by siRNA, antisense oligonucleotides (ASO) and adeno-associated virus (AAV) with shRNAmir directed against huntingtin mRNA. However, delivery remains a pitfall to practical implementation of the therapeutics. siRNA and ASO require long-term infusion. In non-human primates, ASO administered to spinal fluid does not reach the striatum and spread of siRNA is limited in brain. Although promising, AAV-shRNA requires several injections into brain areas and the shRNAmir is unregulated. A gap in HD therapeutics can be filled by microvesicles normally extruded by cells, exosomes. Exosomes with rabies virus glycoprotein (RVG) on their surface can be injected into the blood, cross the blood brain barrier, and enter neurons and glia. RVG-exosomes can carry siRNA cargo. Delivered into the blood circulation, the exosomes deposit siRNA in neurons to engage in RNA interference. Our purpose is to develop exosomes as a therapeutic in HD. The UH2 examines the ability of RVG-exosomes carrying siRNA against huntingtin mRNA to cross the blood brain barrier to enter neurons. Localization in brain and RNAi dependent knock down will be studied. Hyper-functional siRNAs will be sought. Because exosomes are made from cytoplasm of cells, exosome mRNA, miRNA, and implaced siRNA will be identified by deep sequencing. Immune reactivity and immune-neutralization will be studied, since exosomes have potential antigens, like RVG, and will need to be administrated often. The UH3 further establishes exosome-based therapeutics, by study of reversal or prevention of neuropathology and aberrant movement in HD mouse models. Dosing of exosomes will be secured. A team of experts in HD pathogenesis, siRNA development, RNA identification and measurement, RNAi mechanisms and exosome production and brain delivery will carry out the studies. Harnessing exosomes for brain delivery is expected to form a viable therapeutic to reduce expression of mutant huntingtin in patients with HD. Patients with other genetically- based neurodegeneration will benefit.