Mechanisms of Novel Herbal Therapies for Sepsis.

描述(申请人提供)：尽管最近在抗生素治疗和重症监护方面取得了进展，脓毒症仍然是重症监护病房中最常见的死亡原因，仅在美国每年就有225,000名患者死亡。其发病机制部分归因于动态调节的炎症反应，这些炎症反应由早期的促炎细胞因子(如肿瘤坏死因子和干扰素-γ)传播，但由晚期作用的促炎介质(如HMGB1)维持。如果预防性给予针对早期致炎细胞因子的药物(例如，肿瘤坏死因子)，则可以起到保护作用；而能够抑制HMGB1释放或活性的药物，即使在疾病发作后给予，也可以将动物从致命的脓毒症中拯救出来。我们的开创性发现HMGB1是致死性脓毒症的晚期介体，这促使我们进一步研究开发新的实验疗法。我们已经产生的初步数据表明，几种常用中药的主要成分，丹参(丹参，类固醇丹参酮)和绿茶(茶树，表没食子儿茶素没食子酸酯，EGCG)有效地减弱内毒素诱导的HMGB1释放，并在小鼠内毒素血症和败血症模型中提高动物存活率。然而，如果通过临床可行的给药途径(静脉或口服)给药，草药成分单独或组合是否以及如何影响其他炎症刺激(如G+细菌外毒素、CpG-DNA、肿瘤坏死因子或干扰素-γ)诱导的HMGB1释放，从而影响致死性内毒素血症和败血症的结局，目前尚不清楚。目标1中概述的实验将检验这一假设，即草药成分影响由其他外源性(例如G+外毒素或CpG-DNA)或内源性(例如肿瘤坏死因子或干扰素-伽马)刺激诱导的HMGB1的释放，以及草药成分不同地影响HMGB1诱导的一氧化氮、趋化因子和生长因子的释放。在目标2中，我们将测试一个新的假说，即草药成分通过促进细胞外HMGB1的内吞(循环)或通过刺激自噬HMGB1的降解来抑制HMGB1的释放。目标3中概述的实验将检验这一假设，即口服或静脉注射草药成分通过调节腹膜白细胞渗透、全身和腹膜炎症、组织损伤和器官功能障碍来保护动物免受致死性内毒素血症和败血症的侵袭。对这些问题的回答将大大提高我们对两种常用中草药免疫调节机制的了解，并为开发治疗脓毒症和其他炎症性疾病的替代策略提供帮助。

DESCRIPTION (provided by applicant): Despite recent advance in antibiotic therapy and intensive care, sepsis remains the most common cause of death in the intensive care units, claiming > 225,000 victims annually in the U.S. alone. Its pathogenesis is partly attributable to dys-regulated inflammatory responses that are propagated by early proinflammatory cytokines (e.g., TNF and IFN-gamma) but sustained by late-acting proinflammatory mediators (e.g., HMGB1). Agents targeting early proinflammatory cytokines (e.g., TNF) could be protective if given prophylatically; whereas agents capable of inhibiting HMGB1 release or activities could rescue animals from lethal sepsis even if given after onset of disease. Our seminal discovery of HMGB1 as a late mediator of lethal sepsis has prompted further investigation for developing new experimental therapeutics. We have generated preliminary data indicating that major components of several commonly used Chinese herbs, Danshen (Salvia miltiorrhiza, steroid-like tanshinones) and Green tea (Camellia sinensis, epigallocatechin gallate, EGCG) effectively attenuated endotoxin-induced HMGB1 release, and improved animal survival in murine models of endotoxemia and sepsis when given intraperitoneally. However, it is not known whether and how herbal components, individually or in combination, affect HMGB1 release induced by other inflammatory stimuli (e.g., G+ bacterial exotoxin, CpG-DNA, TNF, or IFN-gamma), and consequently influence the outcome of lethal endotoxemia and sepsis if given via clinically feasible (intravenous or oral) route of administration. The experiments outlined in Aim 1 will test the hypothesis that herbal components affect HMGB1 release induced by other exogenous (e.g., G+ exotoxin or CpG-DNA) or endogenous (e.g., TNF or IFN-gamma) stimuli, and that herbal components divergently influence HMGB1-induced release of nitric oxide, chemokines, and growth factors. In Aim 2, we will test a novel hypothesis that herbal components inhibit HMGB1 release either by facilitating endocytic "re-uptake" (recycling) of extracellular HMGB1, or by stimulating autophagic HMGB1 degradation. The experiments outlined in Aim 3 will test the hypothesis that oral or intravenous administration of herbal components protects animals against lethal endotoxemia and sepsis by modulating peritoneal leukocyte infiltration, systemic and peritoneal inflammation, tissue injury, and organ dysfunction. Answers to these questions will significantly improve our understanding of immune modulatory mechanisms of two commonly used Chinese medicinal herbs, and shed light on the development of alternative strategies for treatment of sepsis and other inflammatory diseases.