A human Liver-on-a-Chip model for studying alcohol-associated liver disease

项目摘要 酒精相关性肝病（ALD）仍然是一个严重的健康问题，因为47%的肝脏相关死亡是由于 过度饮酒。尽管进行了广泛的研究工作，但还没有有效的治疗方法。 为ALD开发。延缓ALD有效治疗的原因之一可能是 缺乏适用于研究ALD的人类相关分子机制的模型系统。当前可用 细胞培养系统和啮齿动物ALD模型不能概括与人类相关的ALD病症。到 在体外实验条件的研究中，我们建立了一个肝芯片模型， 是一个三维体外肝脏微生理系统，旨在模拟肝脏的体内功能状态 通过共培养人源性细胞的方法。我们最近设计了一个人类肝脏芯片模型， 用于研究ALD的体外潜在分子机制，基于人原发性 肝脏芯片上的肝细胞表达更高水平的酒精代谢酶，如酒精 脱氢酶1（ADH 1）、醛脱氢酶2（ALDH 2）和CYP 2E1，与单层相比 培养的肝细胞。在这个提议中，基于我们使用肝脏芯片模型的新的初步数据，我们 假设，除了肝细胞，肝窦内皮细胞（LSEC）和醛代谢 LSECs在调节乙醇诱导的肝损伤中起重要作用。我们将调查是否 LSEC中的ALDH2有助于保护通过乙醛发展ALD 使用肝芯片系统（Aim 1）进行代谢。因为纤维化是高死亡率的危险因素， 酒精性肝炎（AH），我们进一步假设肝星状细胞（HSC）的纤维化变化， LSEC的衰老变化有助于增加乙醇诱导的肝损伤的易感性。我们 将研究衰老的LSEC和纤维化的HSC是否有助于 急性肝病中严重ALD的微环境作为严重AH发展的机制， 肝硬化使用肝芯片系统（Aim 2）。拟议的研究将为以下方面的作用提供新的见解： 乙醇诱导的肝细胞凋亡过程中各种肝细胞中ALDH2表达和乙醛代谢的变化 肝损伤，并提供了基础的使用肝芯片模型作为一种新的体外实验工具， 在人类相关条件下研究ALD。

Project Summary Alcohol-associated liver disease (ALD) is still a serious health concern as 47% of liver-related death is due to excessive alcohol consumption. Despite of extensive research efforts, no effective therapy has been developed for ALD. One of the reasons suspending the development of effective therapy for ALD could be the lack of model systems suitable to study human relevant molecular mechanism of ALD. The current available cell culture systems and rodent ALD models do not recapitulate an ALD condition relevant in humans. To investigate more physiological experimental conditions in vitro, we established a Liver-on-a-chip model, which is a 3D in vitro hepatic micro-physiological system designed to simulate the in vivo functional conditions of liver tissues by co-culturing human-originated cells. We recently engineered a human liver-on-a-chip model suitable for investigating the underlying molecular mechanism of ALD in vitro based on the fact that human primary hepatocytes on liver-on-a-chip express higher levels of alcohol-metabolizing enzymes, such as alcohol dehydrogenase 1 (ADH1), aldehyde dehydrogenase 2 (ALDH2), and CYP2E1, compared with monolayer cultured hepatocytes. In this proposal, based on our new preliminary data using a liver-on-a-chip model, we hypothesis that, in addition to hepatocytes, liver sinusoidal endothelial cells (LSECs) and aldehyde metabolism in LSECs play important roles in regulating ethanol-induced liver damage. We will investigate whether ALDH2 in LSECs contributes to the protection for the development of ALD through acetaldehyde metabolism using a Liver-on-a-chip system (Aim 1). Because fibrosis is a risk factor for high-mortality of alcoholic hepatitis (AH), we further hypothesize that fibrotic changes in hepatic stellate cells (HSCs) and senescent changes in LSECs contribute to the increased susceptibility of ethanol-induced liver damage. We will investigate whether senescent LSECs and fibrotic HSCs contribute to the development of the microenvironment of severe ALD in cirrhotic livers as the mechanism of the development of severe AH in cirrhosis using a Liver-on-a-chip system (Aim 2). The proposed study will provide new insight into the role of ALDH2 expression and acetaldehyde metabolism in various liver cells in the progression of ethanol-induced liver damage, and provide the basis for the use of a liver-on-a-chip model as a new in vitro experimental tool to study ALD with human relevant conditions.