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，但还没有有效的治疗方法 为ALD开发。阻碍ALD有效治疗发展的原因之一可能是 缺乏适合研究人类ALD相关分子机制的模型系统。当前可用的 细胞培养系统和啮齿动物ALD模型不能概括人类ALD的相关情况。至 在体外考察了更多的生理实验条件，我们建立了芯片上的肝脏模型，该模型 是一种3D体外肝脏微生理系统，旨在模拟体内肝脏的功能状况 通过共培养人类起源的细胞来获得组织。我们最近设计了一种人体芯片上的肝脏模型，适合 为了研究ALD在体外的分子机制，基于人类原发的 芯片肝脏上的肝细胞表达更高水平的酒精代谢酶，如酒精 脱氢酶1(ADH1)、乙醛脱氢酶2(ALDH2)和细胞色素P450-2E_1，与单层比较 培养的肝细胞。在这项建议中，基于我们使用芯片上肝脏模型的新的初步数据，我们 假设除了肝细胞，肝窦内皮细胞(LSECs)和乙醛代谢 在酒精性肝损伤中，LSECs起着重要的调节作用。我们将调查是否 LSECs中的ALDH2通过乙醛参与保护ALD的发生 使用芯片肝脏系统进行新陈代谢(目标1)。因为纤维化是导致高死亡率的危险因素。 在酒精性肝炎(AH)中，我们进一步假设肝星状细胞(HSCs)和 LSECs的衰老改变增加了酒精性肝损伤的易感性。我们 将研究衰老的LSECs和纤维化的HSCs是否有助于 肝硬变重度酒精性肝病的微环境在重症急性肝病发病机制中的作用 使用芯片上肝脏系统的肝硬变(目标2)。这项拟议的研究将为我们提供新的视角，了解 酒精性肝损伤进展过程中不同肝细胞ALDH2的表达及乙醛代谢 并为将芯片上的肝脏模型用作新的体外实验工具提供了基础。 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.