Treating AT Deficiency with Drugs that Modulate the Proteostasis Network

项目摘要 α-1抗胰蛋白酶缺乏症(ATD)是肝病最常见的遗传原因之一。 肝移植是目前唯一可用的治疗方法。与ATD相关的肝病 其特征是典型的慢性纤维化导致肝硬变和肝细胞过度增殖 易患肝细胞癌。这种病理归因于功能获得、蛋白毒性效应。 在肝细胞的内质网(ER)中聚集的突变型AT Z。我的实验室已经阐明了 肝细胞应对内质网内ATZ蓄积的蛋白毒性效应的可能机制 包括一套不同的细胞内降解途径(蛋白酶体和自噬)和一套不同的 被特异性激活的信号通路(自噬、核因子κB、内质网和线粒体半胱氨酸酶，但不是 未折叠的蛋白质反应)。我们的工作假设是，利用 这些自然发生的，想必具有保护性的蛋白平衡调节机制将具有治疗作用 对ATD所致肝病的影响。最近，我们验证了这一假设，证明了一个 自噬增强剂卡马西平(CBZ)促进ATZ的降解，降低肝脏ATZ的负荷 和体内肝纤维化的小鼠模型。在这里提出的工作中，我们将进一步探讨这一假设 通过调查其他可能对自噬系统采取行动的候选药物，包括 FDA批准的药物、环糊精和粘脂激动剂。该项目还将利用线虫 基于ATD模型的高含量筛选平台(PROJ-2)与计算药理学 分析(核心B)，以发现其他候选治疗方法。最后，我们将研究几个序列 作为候选遗传修饰物的变体，产生于一个独特的家族的整个外显子组测序 队列人口。这些变种将在模型系统(项目3，核心A和C)中进行有效性测试， 希望进入诊断平台，并作为药物开发的新目标，使国家- 最先进的个性化医疗方法。

Project Summary The classical form of α1antitrypsin deficiency (ATD) is one of the most common genetic causes of liver disease. Liver transplantation represents the only treatment currently available. The liver disease associated with ATD is characterized by a stereotypical chronic fibrosis leading to cirrhosis and hepatocyte hyper-proliferation that predisposes to hepatocellular carcinoma. This pathology is attributed to the gain-of-function, proteotoxic effect of mutant AT Z that accumulates in the endoplasmic reticulum (ER) of liver cells. My lab has elucidated the potential mechanisms by which liver cells cope with the proteotoxic effects of ATZ accumulation in the ER including a distinct set of intracellular degradation pathways (proteasomal and autophagic) and a distinct set of signaling pathways that are specifically activated (autophagy, NFκB, ER- and mitochondrial-caspases but not the unfolded protein response). Our working hypothesis is that pharmacological strategies which capitalize on these naturally occurring, presumably protective proteostasis regulatory mechanisms will have a therapeutic effect on the liver disease caused by ATD. Recently, we validated this hypothesis by showing that an autophagy enhancer drug, carbamazepine (CBZ), promotes degradation of ATZ, reduces the hepatic ATZ load and hepatic fibrosis in vivo in a mouse model. In the work proposed here we will pursue this hypothesis further by investigating other drug candidates with putative actions specifically on the autophagy system, including FDA-approved drugs, cyclodextrins and mucolipin agonists. The project will also capitalize on a C. elegans ATD model-based high content screening platform (Proj 2) together with computational pharmacological analyses (core B) to discover additional therapeutic candidates. Finally, we will investigate several sequence variants that are candidate genetic modifiers arising from whole exome sequencing of a unique family and cohort populations. These variants will be tested for validity in model systems (Proj 3, Cores A and C), hopefully to move into diagnostic platforms and as novel targets for drug development that would enable state- of-the art personalized medicine approaches.