Applying a Human Liver Microphysiology System to Develop Therapeutic Strategies for Non-Alcoholic Fatty Liver Disease (NAFLD)

我们建议在定量系统药理学方法中应用四种互补技术， 创建非酒精性脂肪性肝病（NAFLD）的人类实验模型， 疾病，并使用该模型来测试新的治疗策略：1）实施血管化的肝腺泡， 微生理系统（vLAMPS）构建与人类患者来源的肝细胞，作为实验 重现早期NAFLD表型的模型，并作为实验测试新疗法的平台; 2） 基于我们在计算和系统生物学方面的经验，我们将使用来自正常和 NAFLD患者推断疾病进展的途径，以确定潜在的分子蛋白靶点， 是在推断的途径，并使用我们的潜在因素建模方法和三维相似性模型， 确定与这些途径中的靶点在统计学上相互作用的药物; 3）我们将采用我们高效的 用于产生成熟iPSC衍生的肝细胞的方法与基因编辑相结合以并入疾病 将工程化iPSC肝细胞（条件性功能获得/丧失）植入vLAMPS中，以开始测试患者 特异性治疗; 4）应用表型药物筛选技术。 NAFLD包括一系列肝损伤，范围从单纯性脂肪变性（NAFL）到更严重的非酒精性脂肪肝（NAFLD）。 酒精性脂肪性肝炎（NASH）、肝硬化和肝细胞癌（HCC）。肝硬化和HCC导致 肝脏的进行性损伤已经成为肝脏移植的第三大常见原因。的 NAFLD的疾病发病机制是复杂的，并且被以下方面的相当大的个体间差异所混淆： 疾病易感性、进展和并发症，表明需要患者特异性方法。 研究已经确定了NAFLD相关的基因标签和单核苷酸多态性（SNP）。在 特别是在NAFLD中下调的SIRT 1基因，已被鉴定为NAFLD的关键调节因子。 脂肪生成、脂肪生成、内质网应激、脂肪酸氧化、尿素循环和抗氧化反应， 肝细胞马铃薯糖蛋白样磷酸脂酶结构域3（PNPLA 3）基因中的SNP强烈表达。 与肝脂肪变性、纤维化、肝硬化和HCC相关。然而，在以下方面仍然存在重大差距： 我们对NAFLD发病机制的理解。例如，尽管它与NAFLD密切相关， PNPLA 3变体的功能意义尚不清楚。在阐明一个机械的主要限制 PNPLA 3在NAFLD中的作用是其表达和组织特异性的种间差异， 分布，这表明需要人类细胞模型。 这种技术和方法的结合预计将导致新的发展战略， 有可能减缓或阻止早期NAFLD向更严重的疾病进展的新疗法 晚期危及生命的阶段

We propose to apply four complementary technologies in a Quantitative Systems Pharmacology approach to create a human experimental model of non-alcoholic fatty liver disease (NAFLD), the most rapidly growing disease, and to use the model to test novel therapeutic strategies:1) Implement a vascularized, liver acinus microphysiological system (vLAMPS) constructed with human patient-derived, liver cells, as an experimental model to recapitulate early NAFLD phenotypes and as a platform to experimentally test novel therapeutics; 2) Building on our experience in computational and systems biology, we will use RNAseq data from normal and NAFLD patients to infer pathways of disease progression, to identify the potential molecular protein targets that are in the inferred pathways, and to use our latent factor modeling approach and 3D similarity models to identify drugs that statistically interact with the targets in these pathways; 3) We will employ our highly efficient processes for generating mature iPSC-derived hepatocytes combined with gene editing to incorporate disease engineered iPSC hepatocytes (conditional gain/loss of function) into the vLAMPS to begin testing patient specific therapies; and 4) Apply phenotypic drug screening technologies. NAFLD encompasses a spectrum of liver damage ranging from simple steatosis (NAFL) to more serious non- alcoholic steatohepatitis (NASH), cirrhosis and hepatocellular carcinoma (HCC). Cirrhosis and HCC resulting from progressive damage to the liver have become the third most common causes of liver transplants. The disease pathogenesis of NAFLD is complex and confounded by the considerable inter-individual differences in disease susceptibility, progression and complications, suggesting the need for a patient specific approach. Studies have identified NAFLD associated gene signatures and single nucleotide polymorphisms (SNPs). In particular, the SIRT1 gene that is downregulated in NAFLD, has been identified as a key regulator of lipogenesis, gluconeogenesis, ER stress, fatty acid oxidation, urea cycle and the antioxidant response in hepatocytes. A SNP in the patatin-like phospho-lipase domain-containing 3 (PNPLA3) gene is strongly associated with hepatic steatosis, fibrosis, cirrhosis, and HCC. However, there continues to be major gaps in our understanding of the pathogenesis of NAFLD. For example, despite its strong association with NAFLD, the functional significance of the PNPLA3 variant is unknown. A major limitation in the elucidation of a mechanistic role of PNPLA3 in NAFLD has been the interspecies differences in its expression and tissue-specific distribution, suggesting the need for human cell models. This combination of the technologies and approaches is expected to lead to new strategies for development of repurposed and new therapeutics with the potential to slow or halt the progression of early NAFLD to the more advanced, life threatening stages.