Understanding genetic basis for resistance to TNF-induced lethal shock using new

描述（由申请方提供）：中毒性休克的死亡率仍然是一个主要的健康问题，中毒性休克是由感染性因子引起的，感染性因子可触发巨噬细胞过度合成肿瘤坏死因子（TNF）和其他炎症分子。在这里，我们描述了第一次抵抗脂多糖（LPS）和肿瘤坏死因子诱导的死亡在体内的野生型小鼠的MSM株，代表一个新的遗传模型，抵抗中毒性休克。这些小鼠对中毒性休克的显著抵抗力进一步强调了它们对TNF和D-半乳糖胺共同给药引起的急性肝损伤缺乏敏感性，这是一种建立良好的内毒素肝损伤体内模型。在体内抗性数据的支持下，我们表明，原代MSM巨噬细胞表现出另一种表型，因为它们对TNF-或TLR-激动剂诱导的调节性坏死（“坏死性凋亡”）具有抗性，但在体外不对凋亡细胞死亡具有抗性。基于这些结果，我们假设这两个性状是机械连锁的，并建议通过遗传连锁分析，旨在确定的基因座，赋予这两个性状，检查坏死性凋亡和中毒性休克性状之间的联系。在体外结果的进一步扩展中，我们发现TNF介导的体内肝损伤可以通过关键坏死性凋亡调节因子RIP 1激酶的特异性抑制剂来预防。除了细胞死亡表型，我们证明MSM巨噬细胞的TNF合成减少，也可能受到体内RIP 1信号的影响。基于我们的初步数据，我们认为RIP 1激酶是急性中毒性休克的一种介质，并可能成为治疗干预的一个重要新靶点。我们建议进一步表征体外MSM肝细胞和巨噬细胞对TLR激动剂和TNF反应的变化范围，以便更好地确定MSM抵抗中毒性休克的细胞基础。总体而言，这些研究可能为体内中毒性休克和坏死性RIP 1激酶信号传导机制提供重要的新见解，该信号传导也与其他急性病理学有关，如中风，心肌梗死和脑外伤。 公共卫生相关性：中毒性休克的死亡率仍然是一个主要的健康问题，中毒性休克是由感染性因子引起的，感染性因子会触发巨噬细胞过度合成肿瘤坏死因子（TNF）和其他炎症分子。在这项提议中，利用野生小鼠中毒性休克抗性的遗传分析，我们将揭示控制炎症及其程度的新机制。

DESCRIPTION (provided by applicant): Mortality from toxic shock, caused by infective agents that trigger excessive synthesis of tumor necrosis factor (TNF) and other inflammatory molecules by macrophages, remains a major health problem. Here we describe for the first time resistance to lipopolysaccharide (LPS) and TNF-induced death in vivo of wild-derived mice of MSM strain, representing a new genetic model of resistance to toxic shock. The remarkable resistance of these mice to toxic shock is further emphasized by their lack of sensitivity to acute liver injury caused by the co-administration of TNF and D-galactosamine, a well-established in vivo model of endotoxic liver damage. In support of the in vivo resistance data, we show that primary MSM macrophages exhibit another phenotype in that they are resistant to TNF- or TLR-agonists-induced regulated necrosis ("necroptosis") but not apoptosis cell death in vitro. Based on these results, we hypothesize that the two traits are mechanistically linked and propose to examine the connection between necroptosis and toxic shock traits by means of genetic linkage analysis aimed at identification of the loci, which confer both traits. In further extension of the in vitro results, we discovered that TNF-mediated in vivo liver injury can be prevented by a specific inhibitor of a key necroptosis regulator, RIP1 kinase. In addition to cell death phenotype, we demonstrate that TNF synthesis by MSM macrophages is reduced and may also be influenced by RIP1 signaling in vivo. Based on our preliminary data, we suggest that RIP1 kinase is a mediator of acute toxic shock and may represent an important new target for therapeutic intervention. We propose to further characterize the scope of changes in in vitro MSM hepatocyte and macrophage responses to TLR agonists and TNF in order to better determine the cellular basis for MSM resistance to toxic shock. Overall, these studies may provide important new insights into mechanisms of both toxic shock in vivo and necroptotic RIP1 kinase signaling, which has also been implicated in other acute pathologies, such as stroke, myocardial infarction and brain trauma. PUBLIC HEALTH RELEVANCE: Mortality from toxic shock, caused by infective agents that trigger excessive synthesis of tumor necrosis factor (TNF) and other inflammatory molecules by macrophages remains a major health problem. In this proposal, using genetic analysis of resistance to toxic shock in the wild-derived mice, we will reveal novel mechanisms of control of inflammation and its magnitude.