Acute Ethanol-Induced Innate Immune Response in Liver

描述(申请人提供)：内毒素在早期酒精诱导的肝损伤中的作用已得到很好的证实；支持这一假设，即发病机制涉及天然免疫和炎症介质方面。大量研究表明，Kupffer细胞在酒精中毒的发病机制中起着重要作用。具体地说，研究表明，内毒素受体CD14缺陷的小鼠对慢性酒精诱导的肝损伤具有抵抗力。CD14主要表达在库普弗细胞上。这些数据表明，CD14信号可能是酒精相关性肝损伤的关键组成部分。总体假设是来自肠道的内毒素激活库普弗细胞，导致氧化剂产生增加，随后释放肿瘤坏死因子-α。这一假设得到了大量使用基因治疗、基因敲除和转基因动物的研究，以及体内小鼠胃内酒精喂养模型的有力支持。尽管有大量关于内毒素在酒精性肝损伤中作用的新信息，但在我们的理解中仍然存在关键的差距。例如，参与内毒素诱导的氧化剂产生的信号机制，CD14和相关信号成分在发病机制中的调控，以及决定损伤性别差异的分子机制仍不清楚。本应用的目的是解决以下基本假设：1.PI3激酶介导了内毒素诱导的枯否细胞中NADPH氧化酶产生超氧化物。2.氧化敏感转录因子NF-kappaB和AP-1调节急性乙醇中毒后CD14的表达。3.在调节先天性免疫反应和转录因子激活方面的性别差异是增加女性对酒精致病易感性的关键。下面的目标将使用基因传递技术和基因敲除小鼠技术来解决这些关键问题，这些问题与内毒素、PI3激酶激活和CD14表达在急性乙醇毒性和慢性乙醇毒性中的作用有关。

DESCRIPTION (provided by applicant): The involvement of endotoxin in early alcohol-induced liver injury is well established; supporting the hypothesis, that pathogenesis involves aspects of innate immunity and inflammatory mediators. A number of reports have clearly demonstrated that Kupffer cells play a critical role in the pathogenesis due to ethanol. Specifically, it was shown that mice deficient in the endotoxin receptor CD14, which is primarily expressed on Kupffer cells, were resistant to chronic alcohol-induced liver injury. These data suggest that CD14 signaling may be a critical component in alcohol-related liver injury. The overall hypothesis is that LPS from the gut activates Kupffer cells causing an increase in oxidant production and subsequent TNF-alpha release. This hypothesis is strongly supported by a number of studies using gene therapy, knockout and transgenic animals, as well as an in vivo mouse intragastric ethanol-feeding model. Despite a great amount of new information regarding the role of endotoxin in ethanol-induced liver injury, critical gaps still exist in our understanding. For example, the signaling mechanisms involved in LPS- induced oxidant production, the regulation of CD14 and related signaling components in pathogenesis, and the molecular mechanisms determining gender- related differences in injury remain unknown. The purpose of this application is to address the following underlying hypotheses: 1. PI3 kinase mediates LPS-induced NADPH oxidase generation of superoxide in Kupffer cells. 2. Oxidant-sensitive transcription factors NF-kappaB and AP-1 regulate CD14 expression following acute ethanol administration. 3. Gender differences in regulation of innate immune response and transcription factor activation are key to increased susceptibility to ethanol-induced pathogenesis in females. The aims below will use gene delivery techniques and knockout mouse technology to address these critical questions related to roles of LPS, PI3 kinase activation, and CD14 expression in both acute ethanol and chronic ethanol toxicity.