Dual-function vectors for in vivo gene therapy of AAT Liver disease

描述（由申请人提供）：α -1抗胰蛋白酶缺乏症是一种常见的单基因疾病，其中最常见的突变“Z”等位基因（Glu342Lys）在北欧和北美发生的频率非常高。纯合子Z患者患有由于野生型AAT缺乏正常的抗蛋白酶功能而导致的肺部疾病，也可能患有肝脏疾病，这似乎是由肝细胞内聚合和/或聚集的Z-AAT蛋白潴留引起的。表达人类z等位基因的小鼠模型在检查分子终点方面具有实用价值，但不能忠实地再现在严重感染患者中观察到的炎症和肝硬化。在这项应用中，我们建议使用环境挑战和人类干细胞衍生的肝脏嵌合体来开发更好的aat相关肝脏疾病模型，并进一步测试基因治疗/RNA抑制联合策略作为潜在的未来治疗方法。我们的第一个目标是使用乙醇诱导具有人类Z等位基因的小鼠的肝毒性来评估肝细胞癌风险增加的风险，并更好地了解这些肝脏中的促炎和促纤维化途径。然后，这一概念将扩展到使用人源化小鼠肝脏的研究，使用来自iPS细胞的正常或z等位基因阳性的人肝脏干细胞。最后，这两种模型将被用于评估基于raav的RNAi介导的Z-AAT mRNA敲低的效果。

DESCRIPTION (provided by applicant): Alpha-1 antitrypsin deficiency is a common single-gene disorder, in which the most common mutant "Z" allele (Glu342Lys) occurs with remarkably high frequency in Northern Europeans and North Americans. Homozygous Z patients suffer from a lung disease that is due to the lack of normal antiprotease function of the wild-type AAT, and may also suffer from a liver disease, that appears to be triggered by retention of polymeric and/or aggregated Z-AAT protein within hepatocytes. A mouse model expressing the human Z-allele has utility in examining molecular endpoints but does not faithfully reproduce the inflammation and cirrhosis observed in severely affected patients. In this application, we propose to develop better models of AAT-related liver disease using environmental challenges and human stem cell derived liver chimeras, and further to test a combined gene therapy/RNA inhibition strategy as a potential future therapy. Our first aim will use an ethanol induce hepatotoxicity in mice with the human Z allele to assess the risk of increased risk hepatocellualr carcinoma and to better understand the pro-inflammatory and pro-fibrotic pathways in these livers. This concept will then be extended to studies using humanized mouse livers with either normal or Z-allele positive human liver stem cells derived from iPS cells. Finally both of these models will be utilized to assess the effect of rAAV-based RNAi mediated knockdown of the Z-AAT mRNA.