Genetic dissection of neural pathways that modulate systemic inflammation

项目摘要 这项研究的总体目标是提高(I)神经的效力、(Ii)安全性和(Iii)神经的可信度 通过定义功能神经回路，刺激作为脓毒症的治疗方法。在美国，在100-300万人中 每年患有脓毒症的患者中，15%-30%会死亡，许多幸存者会遭受器官损伤。 到目前为止，传统的治疗方案是不够的。在此背景下，神经刺激等 特定穴位的非侵入性电针刺激可减轻全身炎症 与脓毒症有关，并促进实验室动物的存活。到目前为止，一种占主导地位的观点是 驱动迷走神经依赖的抗炎通路，包括激活交感细胞和 随后调节免疫细胞释放促炎细胞因子。然而，有两个 必须解决的重要悬而未决的问题，以便充分发挥ES的治疗潜力 脓毒症的治疗方法。首先，交感神经元的作用仍不明确。去甲肾上腺素(NA)，一种 从交感细胞释放的递质，长期以来一直被认为通过 β-2肾上腺素能受体的激活。然而，NA也可以通过激活α2来促进炎症 肾上腺素能受体，这种促炎信号可以在巨噬细胞前 暴露于细菌衍生的内毒素，如脂多糖(LPS)。因此，它仍然是 未知一)当脓毒症进展到特定阶段时，是否可以反指示ES；以及二)一种策略是否 最大限度地发挥抗炎作用超过促炎活性，是ES治疗严重脓毒症的关键。 其次，人们早就知道，ES只能在特定的穴位驱动迷走神经副交感反射， 但潜在的神经基础是完全未知的。因为未知的身份和解剖结构 驱动迷走神经反射的体感神经元的分布，很难优化刺激 激活这一抗炎途径的参数。为了解决这些悬而未决的问题，我们已经 开发了创新的基因工具来消融、沉默或激活分子定义的交感神经和 体感神经元。基于强有力的初步结果，我们假设：1)感觉神经元 G蛋白偶联受体PROKR2的表达对于低强度ES(0.5 mA)到 驱动迷走神经反射，以及ii)去甲肾上腺素能交感神经元以 神经肽NPY可被高强度ES(3 MA)激活，可抑制和促进 炎症，依赖于脓毒症表现之前或之后的ES。一系列来自 这些假设将得到检验。随着时间的推移，本申请书中概述的研究将使我们能够 说明了不同的神经元通路可以动态地调节脓毒症相关的全身炎症， 通过促进抗炎胜过促炎，有助于改善脓毒症的治疗。 小路。 好了！

Project Summary The broad goal of this research is to improve (i) the potency, (ii) safety, and (iii) the credibility of nerve stimulation as a treatment for sepsis by defining the functional neural circuitry. In the USA, among 1-3 million patients suffering sepsis each year, 15-30% will die and many of the survivors will suffer organ damage. Conventional therapeutic regimens are thus far inadequate. Against this backdrop, nerve stimulations such as non-invasive electroacupuncture stimulation (ES) at specific acupoints can attenuate systemic inflammation associated with sepsis and promote survival of laboratory animals. To date, one dominant view is that ES drives vagal nerve-dependent anti-inflammatory pathways, involving activation of sympathetic cells and subsequent modulation of pro-inflammatory cytokine release from immune cells. However, there are two important unresolved issues that must be addressed in order to realize the full potential of ES as a therapeutic modality for sepsis. First, the roles of sympathetic neurons are still ill-defined. Noradrenaline (NA), one of transmitters released from sympathetic cells, has long been proposed to suppress systemic inflammation, via activation of β2 adrenergic receptors. However, NA can also promote inflammation via activation of α2 adrenergic receptors, and this pro-inflammatory signaling can be sensitized following macrophage pre- exposure to bacteria-derived endotoxins such as the lipopolysaccharide (LPS). Accordingly, it remains unknown i) if ES could be counterindicated when sepsis has progressed to certain stages, and ii) if a strategy to maximize the anti-inflammatory over the pro-inflammatory activity is pivotal for ES to treat severe sepsis. Second, it has been long known that ES can drive vagal parasympathetic reflexes only in specific acupoints, but the underlying neural basis is entirely unknown. Because of unknown identities and anatomical distributions of somatosensory neurons driving vagal reflexes, it becomes difficult to optimize stimulation parameters to activate this anti-inflammation pathway. To address these unresolved issues, we have developed innovative genetic tools to ablate, silence or activate molecularly defined sympathetic and somatosensory neurons. Built upon strong preliminary results, we postulate i) that sensory neurons marked by the expression of the G protein-coupled receptor Prokr2 are required to for low electric intensity ES (0.5 mA) to drive vagal reflexes, and ii) that noradrenergic sympathetic neurons marked by the expression of the neuropeptide NPY, which can be activated by high intensity ES (3 mA), may suppress and promote inflammation, dependent on ES delivered before or after sepsis manifestation. A series of predictions from these hypotheses will be tested. In the fullness of time, the studies outlined in this application will enable us to illustrate distinct neuronal pathways that can dynamically modulate sepsis-associated systemic inflammation, and will help to improve sepsis management by promoting the anti-inflammatory over the pro-inflammatory pathways. !