Mechanisms of Novel Herbal Therapies for Sepsis.

描述（由申请人提供）：尽管最近在抗生素治疗和重症监护方面取得了进展，但脓毒症仍然是重症监护病房最常见的死亡原因，仅在美国每年就有122.5万人死亡。其发病机制部分可归因于早期促炎细胞因子（如TNF和ifn - γ）传播的调节失调的炎症反应，但由晚期促炎介质（如HMGB1）维持。针对早期促炎细胞因子（如TNF）的药物如果预防性给予可能具有保护作用；而能够抑制HMGB1释放或活性的药物即使在发病后给予，也可以使动物免于致命的败血症。我们对HMGB1作为致死性败血症的晚期介质的开创性发现，促使了对开发新的实验性治疗方法的进一步研究。我们的初步数据表明，几种常用中草药的主要成分，丹参（丹参，类固醇样丹参酮）和绿茶（山茶，没食子儿茶素没食子酸酯，EGCG）可以有效地减轻内毒素诱导的HMGB1释放，并提高内毒素血症和脓毒症小鼠模型的动物存活率。然而，目前尚不清楚草药成分是否以及如何单独或联合影响其他炎症刺激（如G+细菌外毒素、CpG-DNA、TNF或ifn - γ）诱导的HMGB1释放，并因此影响致命性内毒素血症和败血症的结果，如果通过临床可行的给药途径（静脉注射或口服）。Aim 1中概述的实验将验证以下假设，即草药成分影响其他外源性（例如G+外毒素或CpG-DNA）或内源性（例如TNF或ifn - γ）刺激诱导的HMGB1释放，并且草药成分对HMGB1诱导的一氧化氮、趋化因子和生长因子的释放有不同的影响。在目标2中，我们将验证一个新的假设，即草药成分通过促进细胞外HMGB1的内吞“再摄取”（再循环）或刺激HMGB1的自噬降解来抑制HMGB1的释放。Aim 3中概述的实验将验证口服或静脉给药草药成分通过调节腹膜白细胞浸润、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命的内毒素血症和败血症的假设。这些问题的答案将大大提高我们对两种常用中草药免疫调节机制的理解，并为脓毒症和其他炎症性疾病的治疗提供替代策略。

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. PUBLIC HEALTH RELEVANCE: Sepsis remains the most common cause of death in the intensive care units, claiming > 225,000 victims annually in the U.S. alone. It is a multi-factorial disorder that triggers an uncontrolled systemic inflammatory response, ultimately leading to multiple organ failure and death. Our recent discovery of HMGB1 as a late mediator of experimental sepsis has prompted investigation of Chinese medicinal herbs as potential HMGB1- targeting therapeutic agents. The long-term goal of this application is to elucidate novel mechanisms by which major components of two medicinal herbs [Danshen (Salvia miltiorrhiza) and Green tea (Camellia sinensis)] inhibit HMGB1 release, and consequently protect animals against lethal endotoxemia and sepsis.