Systems Biology of Alcohol Mediated Aberrant Cellular Interactions in the Liver

描述(申请人提供)：作为人体的主要排毒器官，肝脏暴露在高水平的毒性中，并在严重损伤后发展出再生的能力。然而，长期饮酒完全抑制了这种再生能力。驻留在肝脏内的先天免疫细胞和肝星状细胞的适当功能已被证明是调节肝细胞在组织损伤后复制能力的关键。因此，慢性饮酒很可能会同时影响非实质细胞和肝细胞。为了合成这个复杂的系统，我建立了一个数学模型，描述了库普弗细胞、肝星状细胞和肝细胞在再生过程中的细胞相互作用和转录调控。该模型预测，系统中任何一个组件的变化可能会损害再生，但不会完全抑制再生。然而，如果对系统进行某些组合的更改，再生可能会被完全阻止。具体地说，我预测部分肝切除后的炎症改变 伴有过敏性或过度活跃的肝星状细胞会导致再生完全抑制。此外，模型模拟表明，这些影响应该在再生的启动阶段(肝切除后0-6小时)期间和之后不久观察到。尽管这些机制以前没有在长期饮酒抑制肝脏修复的背景下进行研究，但长期饮酒已被证明会改变肝脏的炎症状态，并可能进展为肝硬变，这是一种以高度激活的星状细胞为特征的疾病。因此，这个项目的目标是通过试验来描述和理解再生早期肝脏内细胞因子微环境和肝星状细胞激活的动态变化如何导致肝脏再生不足。 假设如下：(1)慢性饮酒使肝部分切除(PHX)后促炎症和抗炎细胞因子的平衡发生动态改变，导致肝细胞启动减少；(2)慢性饮酒使肝部分切除后肝星状细胞(HSCs)动态转变为一种明显的抗再生激活表型，从而改变促再生和抗再生肝星状细胞之间的平衡。根据模型预测和初步结果，我们预计会发现，长期饮酒会增加IL-10的产生，减少或延迟IL-6的产生，从而导致再生启动阶段肝细胞启动的减少。我们还预计，在再生的早期阶段，慢性酒精摄入会使HSC的平衡从主要促进再生的激活状态转变为主要反对再生的激活状态(可观察到6小时，并在PHX后12小时达到峰值)。使用系统工具来研究非实质细胞对肝脏修复动物模型的贡献，将允许将这些较少研究的肝脏对酒精适应的方面与较大的 肝脏酒精适应领域，包括基因组规模的基因表达、肝细胞信号和基于miRNA的研究。此外，这项研究中使用的基于计算模型的方法将允许在酒精诱导的非实质细胞激活表型影响整个组织规模的再生的背景下解释我们的分子机制发现。

DESCRIPTION (provided by applicant): As the body's main detoxifying organ, the liver is exposed to high levels of toxicity and has developed the ability to regenerate following even severe injury. However, chronic alcohol consumption completely inhibits this regenerative ability. Proper function of the innate immune cells and hepatic stellate cells resident within the liver has been shown to be critical in modulating hepatocytes' ability to replicate following tissu damage. Therefore, it is likely that chronic alcohol consumption affects both non-parenchymal cells and hepatocytes. To synthesize this complex system, I have developed a mathematical model of cellular interactions and transcriptional regulation between Kupffer cells, hepatic stellate cells, and hepatocytes during regeneration. The model predicts that alterations to any one component in the system may impair, but not completely inhibit, regeneration. However, if certain combinations of alterations are made to the system, regeneration can be completely inhibited. Specifically, I predicts that altered inflammation following partial hepatectomy coupled with hypersensitive or hyperactive hepatic stellate cells leads to complete inhibition of regeneration. Additionally, model simulations suggest that these effects should be observable during and shortly after the priming phase of regeneration (0-6 hrs post-hepatectomy). Although these mechanisms have not been previously studied in the context of chronic alcohol consumption's inhibition of liver repair, chronic alcohol consumption has been shown to alter the inflammatory state of the liver and may progress to cirrhosis, a diseased characterized by highly activated stellate cells. Therefore the goal of this project is to characterize and understand how dynamic alterations in cytokine microenvironment and hepatic stellate cell activation within the liver during the early phases of regeneration contribute to deficient liver regeneration by testing the following hypotheses: (1) chronic alcohol consumption dynamically shifts the balance of pro-inflammatory and anti-inflammatory liver cytokines following partial hepatectomy (PHx), leading to reduced hepatocyte priming, and (2) chronic alcohol consumption dynamically shifts hepatic stellate cells (HSCs) into a distinguishable anti-regenerative activation phenotype post-partial hepatectomy, thereby altering the balance between pro-regenerative and anti- regenerative hepatic stellate cells. Based on model predictions and preliminary results, we expect to find that chronic alcohol consumption increases IL-10 production and decreases or delays IL-6 production leading to a reduction in hepatocyte priming during the priming phase of regeneration. We also expect that chornic alcohol consumption shifts the balance of HSC from a mainly pro-regenerative activation state to a mainly anti-regenerative activation state in the earl phases of regeneration (observable by 6 hrs and peaking at 12 hrs post-PHx). Using systems-tools to investigate the contributions of non-parenchymal cells to an animal model of liver repair will allow integration of these less-studied aspects of liver adaptation to alcohol with the larger field of liver alcohol-adaptation including genome-scale gene expression, hepatocyte signaling, and miRNA-based studies. Additionally, the computational modeling-based approach used in this study will allow for interpretation of our molecular mechanistic findings in the context of alcohol-induced changes to non-parenchymal cell activation phenotype impacting regeneration at a whole-tissue scale.