Alcohol and Monocyte Signaling

 描述(由申请人提供)巨噬细胞(M？)、枯否细胞(KC)和中性粒细胞在酒精性肝病(ALD)的发病机制中介导炎症。以前的研究表明，促炎巨噬细胞对酒精性肝脏炎症的破坏性作用，肝脏中性粒细胞的高渗透预示着人类酒精性肝炎的不良预后。先前在人类的报告和我们在小鼠的初步数据表明，在长期饮酒后，肝脏中既有经典激活的炎性细胞M1，也有激活的M2巨噬细胞。然而，M_1和M_2型巨噬细胞(M？)极化的意义或M？极化的治疗靶点在ALD中的意义仍有待探讨。我们假设M2极化不足允许肝脏出现慢性炎症和偏爱的M1巨噬细胞表型。我们进一步假设，M2 M？极化降低至少部分是由于中性粒细胞吞噬功能不足。我们推测，促进M2巨噬细胞极化的治疗干预将减轻酒精引起的肝脏炎症和损伤。我们最近发现，M？极化的microRNAs也包装在细胞外小泡(EV)中，EV是一种小的膜小泡，在细胞间的通讯中可以作为信号细胞器。在我们的初步实验中，我们观察到在酒精性肝损伤的人和小鼠的循环中，EVS的数量增加。我们假设酒精诱导的EV是肝脏炎症和巨噬细胞极化的重要调节因素。基于这些观察，我们的目标是：特定目的#1：通过a)评估体内酒精诱导的EVS对巨噬细胞极化的影响；b)检测体内酒精诱导的EVS对体内肝脏炎症细胞的招募和表型的影响；c)测试肝源性EVS及其特有的miRNAs对体外巨噬细胞极化的影响；d)评估人类酒精性肝炎患者循环中的EVS，鉴定其miRNA组成和对单核细胞极化的影响。具体目的#2：通过评估酒精对中性粒细胞的调节及其在酒精性肝炎患者体内和体外M1/M2巨噬细胞极化中的作用，探讨酒精性肝病中巨噬细胞极化的触发因素。具体目标#3：探索调节M？表型/极化的干预措施对酒精诱导的小鼠肝脏脂肪变性、炎症和肝损伤的治疗潜力。

 DESCRIPTION (provided by applicant) Macrophages (MØ), Kupffer cells (KC) and neutrophils mediate inflammation in the pathogenesis of alcoholic liver disease (ALD). Previous studies have demonstrated damaging effects of pro-inflammatory macrophages on alcoholic liver inflammation and high neutrophil infiltration in the liver predicted poor outcome in human alcoholic hepatitis. Prior reports in humans and our preliminary data in mice show that both classically activated inflammatory, M1, and alternatively activated, M2, macrophages are present in the liver after chronic alcohol intake. However, the significance of M1 and M2 type macrophage (MØ) polarization or therapeutic targeting of MØ polarization is yet to be explored in ALD. We hypothesize that insufficient M2 polarization permits chronic inflammation and preferential M1 macrophage phenotype in the liver. We further hypothesize that reduced M2 MØ polarization is due, at least partially, to insufficient phagocytosis of neutrophils. We postulate that therapeutic interventions that promote M2 macrophage polarization will attenuate alcohol- induced liver inflammation and injury. We recently found that MØ polarizing microRNAs are also packaged in extracellular vesicles (EVs), small membrane vesicles that could act as signaling organelles in cell-to-cell communication. In our preliminary experiments, we observed that the number of EVs is increased in the circulation of humans and mice with alcoholic liver injury. We hypothesize that alcohol-induced EVs are important regulators of inflammation and macrophage polarization in the liver. Based on these observations, our aims are: Specific Aim#1: To investigate the role of alcohol-induced extracellular vesicles (EVs) on macrophage activation and polarization by a) evaluating the effects of in vivo alcohol-induced EVs on macrophage polarization in vitro; b) testing the effect of in vivo alcohol-induced EVs on recruitment and phenotype of inflammatory cells in the liver in vivo; c) testing the effect of hepatocyte-derived EVs and their characteristic miRNAs on macrophage polarization in vitro; d) evaluating circulating EVs in human patients with alcoholic hepatitis, characterizing their miRNA composition and effect on monocyte polarization. Specific Aim#2: To investigate triggers of macrophage polarization in ALD by evaluating modulation of neutrophils by alcohol and their role in M1/M2 macrophage polarization in vitro and in vivo in patients with alcoholic hepatitis. Specific Aim#3: To explore the therapeutic potential of interventions that modulate MØ phenotype/polarization on alcohol-induced liver steatosis, inflammation and liver damage in mice.