Monocyte regulation in human alcoholic hepatitis.

项目说明/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。它有很高的 死亡率和治疗方案的效果很差。只有一小部分酗酒者会出现这种情况 而且大多数人似乎都能免受这种形式的肝脏损伤。我们实验室以前的工作是 确定转录因子FOX03为可能的保护因子，最近我们确定 AH患者的循环单核细胞在S574失去了磷酸化FOXO_3的能力，因此 不能产生一种通常由酒精诱导的蛋白质(PFOXO_3)，似乎有 具有保护、抗炎的作用。这一缺陷似乎是由于异常高表达的 脱乙酰酶SIRT7。人们早就知道巨噬细胞和单核细胞在人类免疫缺陷中起着重要作用。 急性胰腺炎的发病机制。急性肝炎患者血单核细胞计数升高，单核细胞和巨噬细胞均 刺激引起的炎性细胞因子产生增加。此应用程序将专门检查 急性酒精性肝炎和重度酒精消耗者的血液单核细胞和肝脏切片 从未发生过肝病以确定导致FOXO_3异常磷酸化的机制 单核细胞，磷酸化缺陷对AH患者单核细胞功能异常的后果，以及 FOXO_3途径异常是否为AH发生的易感因素。我们 试图验证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症细胞因子的产生 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SIRT7 防止pFOXO_3的形成，可作为潜在的治疗靶点。最后，我们建议测试 SIRT7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 有两个特定目的的假设。目标1将确定pFOXO_3、SIRT7和 急性酒精性肝炎患者循环单核细胞的炎症反应。这些 实验将包括从酒精性肝炎患者身上获取血液单核细胞，并适当地 对照组，检测FOXO_3的磷酸化与体外细胞凋亡和细胞因子的关系 回应。目的2将研究pFOXO_3在AH易感性中的作用。这些人将检查血液 有不同发病风险的饮酒非急性期患者的单核细胞 从酒精相关MVA死亡患者的尸检标本中提取的切片。总体而言，这项提议将 用人类疾病标本严格检验一种新的致病机制假说 酒精性肝炎。并将把这项工作从细胞培养扩展到老鼠模型，再到患有 为这种疾病开发新的治疗方法的最终目标。

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.