Intranasal gene delivery for Alzheimer’s disease

项目概要/摘要 铁超载疾病，包括遗传性血色素沉着病 (HH) 和输血性血红蛋白病（例如，血红蛋白病） 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 超负荷是多种代谢疾病发生和进展的明确危险因素， 包括心肌病、肝硬化、关节炎、糖尿病和高甘油三酯血症。重要的是增加铁质 大脑中的储存与神经退行性疾病（例如阿尔茨海默病、帕金森病和 亨廷顿病）。尽管铁螯合剂可以有效去除体内多余的铁，但它们表现出 显着的毒性，包括胃肠道出血、粒细胞缺乏症、感染、心动过速、肾衰竭 和肝纤维化。此外，没有螯合剂可以有效地恢复大脑中不适当的高铁含量。 患有神经退行性疾病的患者。因此，对于新的治疗策略的需求尚未得到满足 控制铁在大脑中的运输。铁转运蛋白 (FPN) 是主要的铁转运蛋白，负责 细胞内铁的输出。由于 FPN 对于肠道从饮食中吸收铁以及铁释放也至关重要 FPN 的组织特异性调节可以从巨噬细胞中回收金属用于红细胞生产 是改变脑铁转运的极佳治疗靶点，且全身效应最小。基因疗法可以 可能预防多种神经退行性疾病，包括阿尔茨海默病、帕金森病和 亨廷顿舞蹈症，通过传递编码治疗分子的核酸来治疗。反之，基因沉默 选择性降低不需要的分子的水平，例如致癌蛋白和促炎蛋白 细胞因子。我们最近证明，鼻内施用纳米粒子中的 mRNA 可显着 大脑中荧光素酶和 GFP 等报告基因的蛋白质表达上调。这些结果 表明体内基因传递可用于铁失调领域，并进一步促使我们 询问通过鼻内途径将 FPN 转基因直接递送至大脑（作用位点）是否可以动员大脑 铁储存，同时避免脱靶效应。因此，我们的假设是 FPN mRNA 鼻内给药 阳离子脂质体 (CL) 中的 FPN 增强大脑 FPN 表达，增加铁从大脑中流出， 改善铁引起的神经元损伤。具体目标集中在 1) 开发和验证 FPN 转基因/CL 可增加大脑 FPN 水平和铁流出，2) 评估 FPN 的治疗效果 使用铁相关阿尔茨海默病小鼠模型进行转基因/CL。总体而言，该策略提供了 在铁催化的神经退行性疾病领域进行选择性、有效和安全的基因治疗方法 其他类型的神经系统疾病。

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.