Intranasal gene delivery for Alzheimer’s disease

项目摘要/摘要 铁超载疾病，包括遗传性血色素沉着症(HH)和输血性血红蛋白病(例如 地中海贫血、骨髓增生异常综合征、镰状细胞性贫血)，影响着全世界数千万人。铁 超负荷是几种代谢性疾病发展和进展的明确风险因素， 包括心肌病、肝硬变、关节炎、糖尿病和高甘油三酯血症。重要的是，铁含量增加 大脑中的储存与神经退行性疾病密切相关(例如阿尔茨海默氏症、帕金森氏症和 亨廷顿氏病)。虽然铁络合剂可以有效地清除体内多余的铁，但它们表现出 严重毒副作用，包括胃肠道出血、粒细胞缺乏症、感染、心动过速、肾功能衰竭 和肝纤维化。此外，没有一种螯合剂可以有效地恢复大脑中不适当的高铁。 患有神经退行性疾病的患者。因此，对一种新的治疗策略的需求尚未得到满足 控制着铁在大脑中的运输。铁转运蛋白(FPN)是铁的主要转运体，负责 输出细胞内的铁。因为FPN对肠道从饮食中吸收铁和释放铁也是必不可少的 从巨噬细胞中回收金属用于生产红细胞，组织特异性地调节FPN可以 作为一个极好的治疗靶点，以最小的全身影响来改变脑铁的运输。基因疗法可以 潜在地预防许多神经退行性疾病，包括阿尔茨海默氏症、帕金森氏症和 亨廷顿病，通过传递编码治疗分子的核酸。相反，基因沉默 选择性地降低有害分子的水平，如致癌蛋白和促炎因子 细胞因子。我们最近已经证明，鼻腔内给药纳米粒中的mRNA显著 报告基因如荧光素酶和绿色荧光蛋白在大脑中的蛋白表达上调。这些结果 这表明体内基因传递可以在铁紊乱领域得到开发，并进一步促使我们 询问通过鼻腔途径将FPN转基因基因直接输送到大脑(作用部位)是否可以调动大脑 铁储存，同时避免偏离目标的影响。因此，我们的假设是鼻腔内注射fpn基因 在阳离子脂质体(CL)中，增强大脑FPN的表达，增加脑组织中铁的外流，并 改善铁诱导的神经元损伤。具体目标集中在1)开发和验证 FPN转基因/CL提高脑内FPN水平和铁外流2)评价FPN的治疗效果 转基因/CL使用铁相关阿尔茨海默病小鼠模型。总体而言，该策略提供了一个 选择性、有效、安全的铁催化神经退行性变基因治疗方法 其他类型的神经性疾病。

PROJECT SUMMARY/ABSTRACT Iron overload disorders, including hereditary hemochromatosis (HH) and transfusional hemoglobinopathies (e.g. thalassemia, myelodysplastic syndrome, sickle cell anemia), affect tens of millions of people worldwide. Iron overload is a well-defined risk factor for the development and progression of several metabolic diseases, including cardiomyopathy, liver cirrhosis, arthritis, diabetes and hypertriglyceridemia. Importantly, increased iron stores in the brain are closely associated with neurodegenerative diseases (e.g. Alzheimer’s, Parkinson’s and Huntington’s diseases). Although iron chelators are efficient to remove excess iron from the body, they exhibit significant toxicities, including gastrointestinal bleeding, agranulocytosis, infection, tachycardia, kidney failure and liver fibrosis. Moreover, there is no chelator that effectively restores inappropriately high iron in the brain of patients with neurodegenerative diseases. Hence, there is an unmet need for a new therapeutic strategy by controlling the transport of iron in the brain. Ferroportin (FPN) is the primary iron transporter responsible for the export of intracellular iron. Since FPN is also essential for intestinal iron uptake from diet as well as iron release from the macrophages to recycle the metal for red blood cell production, tissue-specific modulation of FPN can be an excellent therapeutic target to modify brain iron transport with minimal systemic effects. Gene therapy can potentially protect against a number of neurodegenerative diseases, including Alzheimer’s, Parkinson’s, and Huntington’s diseases, by delivering nucleic acid encoding for therapeutic molecules. Conversely, gene silencing selectively decreases the levels of unwanted molecules, such as oncogenic proteins and pro-inflammatory cytokines. We have recently demonstrated that intranasal administration of mRNA in nanoparticles significantly up-regulated protein expression of the reporter genes, such as luciferase and GFP, in the brain. These results suggested that in vivo gene delivery can be exploited in the area of iron disorders, and further prompted us to inquire if a direct delivery of FPN transgene to the brain (site of action) via the intranasal route can mobilize brain iron stores, while avoiding off-target effects. Thus, our hypothesis is that intranasal administration of FPN mRNA in cationic liposomes (CL) enhances brain FPN expression, increases efflux of iron out of the brain and ameliorates iron-induced neuronal impairments. The specific aims are focused on 1) developing and validating FPN transgene/CL to increase brain FPN levels and iron efflux and 2) evaluating the therapeutic efficacy of FPN transgene/CL using a mouse model of iron-associated Alzheimer’s disease. Overall, this strategy provides a selective, effective and safe approach for gene therapy in the area of iron-catalyzed neurodegenerative and other types of neurological disorders.