Liposome-siRNA-Peptide Complexes as Therapy to Cure Prion Diseases in Mouse Model

描述（由申请人提供）：传染性海绵状脑病（tse）包括羊痒病；牛海绵状脑病（BSE）；鹿和麋鹿慢性消耗病（CWD）；以及人类的库鲁和克雅氏病。PrPRES是正常朊蛋白的一种抗激酶（PK）形式，其积累似乎是这些疾病发病机制的核心。tse是一种无法早期诊断或治疗的致命疾病。RNA干扰（RNAi）是植物和动物中一个相对较新的发现，它可以调节可翻译成蛋白质的RNA的数量，已被实验用于限制病毒、细菌和癌细胞的复制数量。最近在朊病毒疾病的有效治疗方面取得了进展，利用RNAi抑制神经元中正常宿主蛋白PrPC的表达和随后的朊病毒神经病理学，利用了疾病严重程度和进展与神经元中PrPC含量相关的现象。然而，利用编码PrP短发卡RNA的慢病毒递送RNAi，由于递送方法的侵入性、PrPC抑制的面积有限、不可逆性和安全性问题，实验证明其效果有限，临床应用有限。我们最近开发了一种新型的小干扰RNA （siRNA）递送系统，使用脂质体-siRNA-肽复合物（LSPCs）来保护siRNA免受血清降解，特异性地将siRNA传递到神经元，并在两种细胞培养模型中充分敲低PrPC以治愈朊病毒疾病。在这里，我们建议将这项工作扩展到治疗小鼠的两种不同的朊病毒疾病，使用静脉注射LSPCs （iv）将PrP siRNA通过血脑屏障（BBB）传递到整个大脑的神经元。我们的具体目标如下。特异性目标1：确定小鼠LSPC传递动力学和PrPC敲除，以优化LSPC治疗朊病毒疾病的方法为了确定含有PrP sirna的LSPCs是否可以治愈瘙痒病和慢性消耗性疾病（CWD）小鼠模型中已建立的朊病毒感染a.用小鼠适应的瘙痒病和CWD朊病毒菌株感染小鼠b.在临床疾病发病前监测小鼠的早期行为和认知缺陷c.用PrP治疗小鼠并使用不同剂量和时间的方案控制LSPCs

DESCRIPTION (provided by applicant): Transmissible spongiform encephalopathies (TSEs) include scrapie in sheep; bovine spongiform encephalopathy (BSE) in cattle; chronic wasting disease (CWD) in deer and elk; and Kuru and Creutzfeldt-Jakob disease in humans. Accumulation of PrPRES, a proteinase K (PK) resistant form of the normal prion protein, PrPC appears central to the pathogenesis of these diseases. TSEs are invariably fatal diseases for which no early diagnosis or treatment exists. RNA interference (RNAi), a relatively new discovery in both plants and animals that regulates the amount of RNA available for translation into protein, has been used experimentally to limit the amount of viral, bacterial and cancer cell replication. Recent advances toward an effective therapy for prion diseases employ RNAi to suppress expression of a normal host protein, PrPC, in neurons and subsequent prion neuropathology, exploiting the phenomenon that disease severity and progression correlate with the amount of PrPC present in neurons. However, delivery of lentivirus encoding PrP short hairpin RNA for RNAi has demonstrated only modest effectiveness experimentally and limited use clinically due to the invasive delivery method, limited area and irreversibility of PrPC suppression and safety concerns. We have recently developed a novel small interfering RNA (siRNA) delivery system using liposome-siRNA-peptide complexes (LSPCs) to protect siRNAs from serum degradation, deliver siRNA specifically to neurons and knockdown PrPC sufficiently to cure prion disease in two cell culture models. Here we propose to extend this work to cure two distinct prion diseases in mice using LSPCs injected intravenously (iv) to deliver PrP siRNA across the blood-brain-barrier (BBB) to neurons throughout the brain. Our specific aims are as follows. SPECIFIC AIM 1: Determine kinetics of LSPC delivery and PrPC knockdown in mice to optimize LSPC therapy to treat prion disease SPECIFIC AIM 2: To determine whether PrP siRNA-containing LSPCs can cure established prion infection in mouse models of scrapie and chronic wasting disease (CWD) a. Infect mice with mouse-adapted strains of scrapie and CWD prions b. Monitor mice for early behavioral and cognitive defects prior to onset of clinical diseas c. Treat mice with PrP and control LSPCs using regiments varying in dosage and timing PUBLIC HEALTH RELEVANCE: Prion and other neurodegenerative diseases such as Alzheimer's disease are devastating illnesses that greatly impact public health, agriculture and wildlife in North America and around the world. These diseases invariably result in death, so finding an effective therapy to treat these diseases would greatly improve the well-being of humans and wildlife.