Monocyte regulation in human alcoholic hepatitis.

项目描述/摘要 急性酒精性肝炎（AH）是一种由酗酒引发的严重炎症性肝病。它具有高 死亡率和治疗选择的效果都很差。AH只发生在一小部分重度饮酒者中 并且大多数个体似乎被保护免于这种形式的肝损伤。我们实验室以前的工作 我们鉴定了转录因子FOXO 3作为一种可能的保护因子，最近我们已经确定 来自AH患者的循环单核细胞已经失去了在S574磷酸化FOXO 3的能力， 不能产生一种蛋白质（pFOXO 3），这种蛋白质通常由酒精诱导， 有保护作用和抗炎作用。这种缺陷似乎是由于异常高表达的 脱乙酰酶SIRT 7。长期以来，人们已经知道巨噬细胞和单核细胞在免疫调节中起重要作用。 AH的发病机制。血液单核细胞计数在AH中升高，单核细胞和巨噬细胞都有 对刺激物的反应导致炎性细胞因子产生增加。该应用程序将专门检查 血液单核细胞和肝脏切片来自AH患者和重度饮酒个体， 从未患过肝病，以确定导致FOXO 3磷酸化异常的机制。 单核细胞，磷酸化缺陷对AH中单核细胞功能异常的后果，以及是否 FOXO 3通路的异常与否是AH发生的易感因素。我们 试图检验饮酒诱导单核细胞和单核细胞中pFOXO 3形成的假设， 巨噬细胞和pFOXO 3随后诱导细胞凋亡并抑制炎性细胞因子的产生 从而限制酒精引起的炎症。我们进一步假设单核细胞高表达SIRT 7 防止pFOXO 3形成，并可作为潜在的治疗靶点。最后，我们建议测试 SIRT 7表达变化导致的形成pFOXO 3的可变能力是否在 确定不同个体对酒精性肝病的内在易感性。我们将测试这些 有两个具体目标的假设。目的1将确定pFOXO 3、SIRT 7和 急性酒精性肝炎患者循环单核细胞的炎症反应这些 实验将涉及从酒精性肝炎患者获得血液单核细胞， 对照，并检查FOXO 3磷酸化与体外细胞凋亡和细胞因子之间的关系 应答目的2将研究pFOXO 3在AH易感性中的作用。这些可以检验血液 来自具有不同AH发展风险的饮酒非急性病患者的单核细胞， 来自死于酒精相关MVA的患者的尸检标本的切片。总的来说，这项建议将 使用人类疾病标本来严格测试一种新的发病机制的机制假设， 酒精性肝炎并将把这项工作从细胞培养扩展到小鼠模型， 最终目标是开发针对这种疾病的新的治疗方法。

PROJECT DESCRIPTION/SUMMARY Acute alcoholic hepatitis (AH) is a severe inflammatory liver disease triggered by binge drinking. It has high mortality and treatment options are only poorly effective. AH only occurs in a small minority of heavy drinkers and most individuals appear to be protected from this form of liver injury. Previous work from our lab has identified the transcription factor FOXO3 as a possible protection factor and more recently we have determined that circulating monocytes from patients with AH have lost the ability to phosphorylate FOXO3 at S574 thus failing to generate a form of the protein (pFOXO3) that is normally induced by alcohol and appears to have protective, anti-inflammatory effects. This defect appears to result from abnormally high expression of the deacetylase SIRT7. It has long been known that macrophages and monocytes play an important role in the pathogenesis of AH. Blood monocyte counts are elevated in AH and both monocytes and macrophages have elevated inflammatory cytokine production in response to stimuli. This application will specifically examine blood monocytes and liver sections from patients with AH and heavy alcohol-consuming individuals who have never developed liver disease to determine the mechanisms that lead to abnormal FOXO3 phosphorylation in monocytes, the consequences of phosphorylation defects to abnormal monocyte function in AH, and whether or not abnormalities in the FOXO3 pathway serve as a susceptibility factor for the development of AH. We seek to test the hypothesis that alcohol consumption induces the formation of pFOXO3 in both monocytes and macrophages and pFOXO3 subsequently induces apoptosis and suppresses inflammatory cytokine production thus limiting alcohol-induced inflammation. We further hypothesize that high monocyte expression of SIRT7 prevents pFOXO3 formation and could serve as a potential therapeutic target. Finally, we propose to test whether variable ability to form pFOXO3 as a result of variations of SIRT7 expression plays a role in determining the intrinsic susceptibility of different individuals to alcoholic liver disease. We will test these hypotheses with two specific aims. Aim 1 will determine the relationship between pFOXO3, SIRT7 and inflammatory responses in circulating monocytes from patients with acute alcoholic hepatitis. These experiments will involve obtaining blood monocytes from patients with alcoholic hepatitis and appropriate controls, and examining the relationship between FOXO3 phosphorylation and in vitro apoptosis and cytokine responses. Aim 2 will examine the role of pFOXO3 in susceptibility to AH. These will examine blood monocytes from alcohol-consuming non-acutely ill patients with varying risk of development of AH, and liver sections from autopsy specimens from patients who died from alcohol-related MVAs. Overall, this proposal will use human disease specimens to rigorously test a novel mechanistic hypothesis of the pathogenesis of alcoholic hepatitis. and will extend the work from cell culture to mouse models to human patients with the ultimate goal of developing novel therapeutic approaches for this disease.