Targeting macrophage maladaptation for bacterial sepsis treatment

摘要脓毒症导致大量生命损失，并给社会带来巨大的经济负担。那里 除了抗生素和生命支持外，没有有效的治疗方法可用于人类败血症。越来越 脓毒症是一个双相过程，包括：1）早期高能量需求的过度炎症 可引起炎性休克状态和2）低能量供应免疫抑制状态， 免疫代谢瘫痪，同时对抗氧化损伤。这两个阶段是无缝衔接的 或者甚至是同时发生的。这使得脓毒症的治疗极其困难，许多疗法，如抗- 炎性皮质类固醇通常使结果恶化。巨噬细胞（MΦs）在整个过程中发挥重要作用 脓毒症的过程在过度炎症阶段，MΦs感知病原体相关的分子模式， 通过受体如toll样受体（TLR）和含有NOD、LRP和pyrin结构域的受体， 蛋白3（NLRP 3）。MΦ NLRP 3炎性体激活并导致IL-1β分泌导致急性器官损伤 损伤相关分子模式（DAMP）的损伤和释放， 道路，形成恶性循环。因此，MΦ NLRP 3炎性小体是导致炎症的主要因素。 细菌性脓毒症的过度炎症阶段。伴随着炎性小体的激活，MΦ经历了一个 广泛的细胞代谢重新布线，有利于糖酵解，并将线粒体从ATP生成转为反应性 氧（ROS）产生，导致线粒体氧化应激、代谢瘫痪和MΦ 免疫抑制阶段的无反应性。此外，NLRP 3炎性小体激活导致GSDMD-1。 介导的焦亡细胞死亡（焦亡），直接将MΦ从对抗继发感染的斗争中清除。 最近，我们发现在MΦs中，丙酮酸脱氢酶激酶1（PDHK 1）在 协调炎性体活化和代谢重组。在用LPS和ATP或阿霉素处理的MΦ中， 刺激炎性小体活化、二氯乙酸盐（DCA，丙酮酸盐类似物和泛PDHK抑制剂）或JX 06 （一种合成的小分子和选择性PDHK 1抑制剂）有效抑制IL-1β分泌和细胞增殖。 死亡，改善线粒体完整性，并将线粒体从ROS生产重编程为ATP 一代在小鼠盲肠结扎和穿孔（CLP）模型中，PDHK抑制显著降低了血浆 IL-1β水平。在这个STTR第一阶段项目中，我们将测试JX 06可以作为一种新的 治疗细菌性败血症。我们提出了两个具体目标：SA 1。测定JX 06对培养的 体外原代小鼠和人细胞以及小鼠体内，并研究其在小鼠体内的药代动力学。SA 2.到 使用脓毒症的CLP模型建立JX 06在各种小鼠品系中的有效性。本STTR阶段 1个项目将验证MΦ PDHK 1在细菌性脓毒症中的作用，并为开发JX 06提供概念验证 或其类似物作为细菌性脓毒症的新治疗剂。成功完成这些建议 研究将成为进一步发展的里程碑。

Summary. Sepsis results in massive loss of life and places a significant economic burden on society. There are no effective treatments available for human sepsis other than antibiotics and life support. It is increasingly clear that sepsis is a bi-phasic process comprised of 1) an early high-energy demanding hyperinflammation state that can cause inflammatory shock and 2) a low energy supply immunosuppression state that promotes immunometabolic paralysis while countering oxidative damage. These two phases are seamlessly connected or even concurrent. This makes sepsis treatment extremely difficult, and many therapies such as anti- inflammatory corticosteroids often worsen the outcome. Macrophages (MΦs) play essential roles throughout the course of sepsis. In the hyperinflammation phase, MΦs sense pathogen-associated molecular patterns (PAMPs) through receptors such as toll-like receptors (TLRs) and NOD-, LRP-, and pyrin domain-containing protein 3 (NLRP3). MΦ NLRP3 inflammasome activation and resulting IL-1β secretion cause acute organ damage and release of damage-associate molecular patterns (DAMPs), which act back on the inflammatory pathways, forming a vicious cycle. Therefore, the MΦ NLRP3 inflammasome is a major contributor to the hyperinflammation phase of bacterial sepsis. Concomitant with inflammasome activation, MΦs undergo a broad cellular metabolic rewiring that favors glycolysis and turns mitochondria from ATP generation to reactive oxygen species (ROS) production, leading to mitochondrial oxidative stress, metabolic paralysis, and MΦ anergy in the immunosuppression phase. In addition, NLRP3 inflammasome activation results in GSDMD- mediated pyroptotic cell death (pyroptosis), directly removing MΦs from the fight against secondary infections. Recently, we identified that in MΦs, pyruvate dehydrogenase kinase 1 (PDHK1) plays a critical role in coordinating inflammasome activation and metabolic rewiring. In MΦs treated with LPS and ATP or Nigericin to stimulate inflammasome activation, dichloroacetate (DCA, a pyruvate analog and pan-PDHK inhibitor) or JX06 (a synthetic small-molecule and selective PDHK1 inhibitor) effectively suppressed IL-1β secretion and cell death, improved mitochondrial integrity, and reprogramed mitochondria from ROS production to ATP generation. In a mouse cecal ligation and puncture (CLP) model, PDHK inhibition significantly reduced plasma IL-1β levels. In this STTR Phase 1 project, we will test the hypothesis that JX06 can be developed as a novel therapy for bacterial sepsis. We propose two specific aims: SA1. To determine the toxicity of JX06 in cultured primary mouse and human cells in vitro and mice in vivo, and to study its pharmacokinetics in mice. SA2. To establish the effectiveness of JX06 in various mouse strains using the CLP model of sepsis. This STTR Phase 1 project will validate the role of MΦ PDHK1 in bacterial sepsis and provide a proof of concept to develop JX06 or its analog as a new therapeutic agent for bacterial sepsis. The successful completion of these proposed studies will serve as a milestone for the further development effort.