Investigations on pathomechanism, diagnosis and treatment in bacterial shock-For preposal of new padadigm

细菌性败血性休克已成为世界范围内最重要的临床问题之一。在这个项目中，我们根据潜在的介质研究脓毒性休克的病理机制。我们首先发现内毒素和肽聚糖刺激巨噬细胞和血小板产生内源性大麻素、内酰胺和2-花生四烯酰甘油三酯（2-AG）。产生的内源性大麻素作用于其特异性受体CB1、CB2和VR1，并发挥多种生理活性，包括低血压、免疫抑制和精神运动作用。然而，过多的内源性大麻素在循环中导致低血压性休克，并作为早期介质。对于后期介质，我们鉴定了HMGB1，即高分子基团蛋白1。HMGB1被认为是一种dna结合核因子。然而，该蛋白从大多数坏死细胞和活化的巨噬细胞中释放出来，并作用于RAGE（晚期糖基化终产物受体），RAGE在各种类型的细胞中表达。HMGB1/RAGE信号导致自由基的产生，NF-kB、Rac和CDC42的激活，导致许多器官的屏障功能障碍，并可能导致出血、炎症和水肿。因此，我们提出该蛋白可能在感染性休克中起晚期介质的作用。建立了HMGB1的ELISA特异性检测方法。由此，我们证实了致命的感染性休克患者中蛋白质的增加。在实验动物模型中，从循环中去除HMGB1可显著改善休克和致死率。我们也证实HMGB1参与了急性肺损伤和ARDS。因此，HMGB1可能介导器官功能障碍，并作为感染性休克的晚期致死因素。

Bacterial septic shock has been one of the most crucial clinical problems in all over the world. In this project, we investigated pathomechanism of septic shock based on the underlying mediators. We first showed that endocannabinoids, anandamide and 2-arachidonylgycerol(2-AG) are produced by the macrophages and platelets stimulated with endotoxin and peptidoglycan. The produced endocannabinoids act on their specific receptors, CB1,CB2 and VR1, and exert diverse physiologic activities including hypotension, immune depression and psychomotor actions. However too increased endocannabinoids in the circulation result and cause hypotensive shock, and act as an early mediator.For the late mediator, we identified HMGB1, high molecular group protein 1.HMGB1 has been known as a DNA-binding nuclear factor. However, the protein is released from most of necrotic cells and activated macrophages, and acts on RAGE(receptor for advanced glycation endproducts), which is expressed variety types of cells. HMGB1/RAGE signaling causes production of radicals, activations of NF-kB, Rac, and CDC42, resulting barrier dysfunction in many organs, and may result hemorrhages, inflammation and edema. Thus we proposed that the protein may act as a late phase mediator in septic shock. We established specific assay method of HMGB1 by ELISA. Using this, we confirmed that protein is increased in fatal septic shock patients. In experimental animal models, removal of HMGB1 from the circulation dramatically improved the shock and lethality. We also confirmed that HMGB1 is involved the acute lung injury and ARDS. Thus HMGB1 may mediate organ dysfunctions and act as a late lethal factor in septic shock.