Role of alcohol adapted Kupffer cells in the progression and resolution of ALD

项目总结 酒精相关性肝病(ALD)是一个主要的世界性健康问题，它占 在美国，每年大约有40,000人死亡。ALD的一个主要死亡原因是急性心肌梗死 肝功能衰竭事件称为酒精性肝炎(AH)。急性呼吸窘迫综合征的发病机制 在ALD患者中的作用尚不清楚。ALD最重要的治疗方法是戒酒。 不幸的是，一些ALD患者在停止饮酒后，在肝脏方面没有得到充分的改善 功能或纤维化。同样，导致戒酒后疾病解决不完全的机制 都是未知的。肝巨噬细胞，包括Kupffer细胞和浸润性巨噬细胞，在 在ALD中调节肝功能的作用，但它们如何在AH的发病中起作用？有什么作用？ 它们在戒酒后肝脏疾病的结局中起到了作用，目前尚不清楚。我们最近 开发了一种新的西方饮食酒精(WDA)ALD模型，它复制了人类酒精的特征- 小鼠的相关性脂肪性肝炎。利用单细胞RNA测序，我们已经鉴定出酒精 特异性Kupffer细胞亚群，并通过选择性地消融它们来评估这些亚群的功能 白喉毒素受体技术。在酒精暴露期间，KC消融导致肝功能衰竭， 肝细胞去分化为祖细胞样表型非常类似于人类的情况 阿。这一结果表明，KC在维持差异化方面发挥着以前未被认识到的作用 慢性酒精暴露时肝细胞功能的变化。这项提议的总体假设是 在酒精暴露期间，KCs产生信号，如外体let-7，有助于维持 处于分化状态的肝细胞。KCs或KC功能丧失可引发类似AH的肝脏丧失 功能。戒酒后，KCs也需要恢复肝脏的动态平衡和纤维化。 决议。KC亚群丢失可延缓ALD纤维化的恢复并抑制其消退。在 目前的建议是，我们将确定特定的KC和IM亚群如何在 酒精暴露，它们在停止饮酒后如何改变和发挥作用，以及如何做到这一点 信息可以用来改善肝功能，促进ALD的恢复。我们将实现 这些目标有以下具体目标。(1)确定KC子集和IM子集的功能 ALD小鼠模型，(2)确定Kupffer细胞丢失如何促进肝细胞向 祖细胞样状态，以及(3)评估M-Φ亚群在纤维化发展和消退中的作用 在戒酒之后。了解控制酒精存在和功能的因素- 特定的KC亚群将提供机会来开发基于巨噬细胞的疗法来逆转 急性酒精性肝病患者的肝功能衰竭和加速戒酒患者的恢复 消费。

PROJECT SUMMARY Alcohol-associated liver disease (ALD) is a major world-wide health problem that accounts for approximately 40,000 deaths per year in the US. A major cause of death in ALD is the onset of an acute liver failure event called alcohol-associated hepatitis (AH). The mechanisms that cause the onset of AH in patients with ALD are unknown. The most important treatment for ALD is alcohol abstinence. Unfortunately, some people with ALD who stop drinking fail to adequately improve in terms of liver function or fibrosis. Again, the mechanisms leading to incomplete disease resolution after abstinence are unknown. Liver macrophages, including Kupffer cells and infiltrating macrophages, play a central role in regulating liver function during ALD but how they contribute to the onset of AH and what role they play in the outcome of liver disease following alcohol abstinence is unknown. We recently developed a new western diet alcohol (WDA) model of ALD that reproduces features of human alcohol- associated steatohepatitis in mice. Using single cell RNA sequencing, we have identified alcohol specific Kupffer cell subsets and assessed the function of these by selectively ablating them using diphtheria toxin receptor techniques. During alcohol exposure, KC ablation resulted in liver failure with hepatocytes de-differentiating into a progenitor-like phenotype very similar to the situation in human AH. This result demonstrates that KCs play a previously unrecognized role in maintaining differentiated hepatocyte function during chronic alcohol exposure. The overall hypothesis of this proposal is that during alcohol exposure, KCs produce signals, such as exosomal Let-7, that help to maintain hepatocytes in their differentiated state. Loss of KCs or KC function can trigger an AH-like loss of liver function. Upon alcohol cessation, KCs are also required for resumption of liver homeostasis and fibrosis resolution. Loss of KC subsets can delay recovery and suppress resolution of ALD fibrosis. In the current proposal we will determine how specific KC and IM subsets regulate hepatocyte function during alcohol exposure, how they change and function upon cessation of alcohol consumption, and how this information can be used to improve liver function and enhance recovery from ALD. We will achieve these goals with the following specific aims. (1) To determine the functions of KC and IM subsets in a mouse model of ALD, (2) to determine how Kupffer cell loss promotes hepatocyte transition to a progenitor-like state, and (3) to assess the role of MΦ subsets in fibrosis development and resolution after alcohol cessation. Understanding the factors that regulate the presence and function of alcohol- specific KC subsets would provide the opportunity to develop macrophage-based therapies to reverse liver failure in patients with AH and accelerate recovery in patients with ALD who cease alcohol consumption.