Elucidating diacylglycerol lipase beta-mediated effects on neuroinflammatory signaling

项目摘要/摘要 这项建议的总体目标是了解二酰甘油脂肪酶(DAGLβ)是如何减弱的 神经炎性信号和相应的疼痛。作为对组织损伤的反应，促炎信号 (脂类或细胞因子)由受损的细胞释放，并启动基于细胞的适应性和先天免疫 保护宿主的机制。这些先天免疫细胞的激活导致了一系列 免疫调节级联反应，触发额外的炎症和刺激附近的神经，引发 疼痛。其中一个级联反应涉及促炎性二十烷(即前列腺素)脂的产生。 而另一个级联则集中在对细胞因子表达至关重要的促炎基因的转录上。 目前的药物干预措施要么在创伤部位起作用(即非类固醇抗炎 药物、非类固醇抗炎药)或由此产生的疼痛反应(即阿片类药物)的传递。然而，这些疗法中没有一种 提供有效的长期治疗，因为最终建立的药物耐受性会引起不良副作用 从慢性病到上瘾。我们迫切需要的是一种疗法，这种疗法在不同的疾病中表现出疗效。 不仅抑制炎症信号，而且还可以缓解疼痛，而不会在长期暴露的情况下产生后果。 DAGLβ是一种通过二酰甘油脂类的水解酶直接减弱二十烷基类化合物产生的酶。 前列腺素合成途径的上游。已发现抑制DAGLβ有效地抑制了 通过炎症性(急性)或神经性(慢性)疼痛模型促进抗伤害感受。 此外，长期接触DAGLβ抑制剂不会产生特征性的代谢、行为或 令人上瘾的副作用。我们理解中的一个关键差距是DAGLβ如何减弱细胞因子的产生 有强有力的证据表明，它在二十烷类化合物产生中的作用并不能解释它在 作为非甾体类抗炎药的慢性疼痛，也针对二十烷类化合物的产生，对同样的慢性疼痛往往无效 模特们。在这里，我们描述了DAGLβ活性和基于激酶的信号之间的一种新的联系，这是已知的 调节促炎细胞因子基因转录。我们试图确定DAGLβ通过什么机制 调节神经炎性信号最终将DAGLβ小分子抑制剂翻译成 缓解慢性疼痛的有效疗法。在这项建议中，我们的第一个目标是确定机制 通过它，DAGLβ活性调节一个基于激酶的信号网络，独立于经典的 前列腺素脂类产生途径。我们的第二个目标是测试DAGLβ抑制剂在 通过反复暴露抑制慢性炎症小鼠的伤害性行为。 这个项目的成功完成将扩大我们对脂质信号参与的理解 神经炎症，确定不同代谢信号通路之间的新的串扰，并展示 DAGLβ抑制剂替代当前治疗慢性疼痛药物策略的治疗潜力。

Project Summary/Abstract The overall goal of this proposal is to understand how diacylglycerol lipase beta (DAGLβ) attenuates neuroinflammatory signaling and consequential pain. In response to tissue damage, proinflammatory signals (lipids or cytokines) are released by injured cells and initiate cell-based adaptative and innate immunity mechanisms to protect the host. The activation of these innate immune cells results in a series of immunomodulatory cascades that triggers additional inflammation and the stimulation of nearby nerves, eliciting pain. One of these cascades involves the production of proinflammatory eicosanoid (i.e. prostaglandin) lipids while another cascade centers around the transcription of proinflammatory genes key to cytokine expression. Current pharmacological interventions either work at the site of trauma (i.e. non-steroidal anti-inflammatory drugs, NSAIDs) or in the transmission of resulting pain responses (i.e. opioids). However, none of these therapies provide efficacious long-term treatment as the eventual drug tolerance that builds elicits adverse side effects ranging from chronic disease to addiction. What is desperately needed is a therapy that displays efficacy in not only thwarting inflammatory signaling, but also relieving pain without consequence over long periods of exposure. DAGLβ is an enzyme that directly attenuates eicosanoid production through the hydrolysis of diacylglycerol lipids upstream of the prostaglandin synthetic pathway. Inhibition of DAGLβ has been found to be efficacious in promoting antinociception sourced through either inflammatory (acute) or neuropathic (chronic) pain models. Moreover, long-term DAGLβ inhibitor exposure does not produce characteristic metabolic, behavioral or addictive side effects. A critical gap in our understanding is how DAGLβ attenuates cytokine production as evidence strongly suggests that its role in eicosanoid production does not explain its pain-relieving effects in chronic pain as NSAIDs, which also target eicosanoid production, are often ineffective in these same chronic models. Here we describe a novel connection between DAGLβ activity and kinase-based signaling that is known to regulate proinflammatory cytokine gene transcription. We seek to identify the mechanisms by which DAGLβ regulates neuroinflammatory signaling for the eventual translation of DAGLβ small molecule inhibitors into efficacious therapies for chronic pain alleviation. In this proposal, our first aim is the determine the mechanisms through which DAGLβ activity modulates a kinase-based signaling network, separate from the canonical prostaglandin lipid production pathway. Our second aim is to test the applicability of DAGLβ inhibitors in suppressing nociceptive behaviors displayed by chronically inflamed mice through repeated exposure. Successful completion of this project will broaden our understanding of lipid signaling involved in neuroinflammation, identify novel cross-talk between distinct metabolic signaling pathways, and demonstrate the therapeutic potential of DAGLβ inhibitors in replacing current drug strategies for the treatment of chronic pain.