Molecular basis for adenosine A3 receptor agonists in the treatment of migraine

项目总结/摘要 尽管最近的进展与新的疗法，一个巨大的比例偏头痛患者仍然无法使用 已建立的治疗方法。对于许多患者来说，治疗并不有效，即使是新批准的CGRP mAb， 只有约50%的应答率。对于其他人来说，由于禁忌症（曲坦类）或阿片类药物， 不适合长期使用，甚至加重现有的偏头痛。这表明，仍有 我们对偏头痛机制的理解存在重大差距。因此，我们必须调查 涉及的潜在分子机制，旨在确定潜在的新治疗靶点， 以便迅速转移到诊所最近的数据已经确定腺苷A3受体（A3 AR）作为一种新的靶点 止痛药我们最近的工作还确定了高度有毒的反应性氮氧化物种的产生， 过氧亚硝酸盐（PN），引起下游修饰的谷氨酸能信号和NLRP 3/IL-1β驱动的 神经炎症，介导伤害性脊髓敏化。我们发现A3 AR激动剂可以减弱这些 在不同的啮齿动物模型的神经性疼痛的伤害感受机制，提供持久的疼痛缓解。尽管 因此，关于三叉神经血管性偏头痛模型中的A3 AR-PN机制知之甚少。然而，我们的初步 数据表明，A3 AR表达于沿着偏头痛的重要外周和中心区域， A3 AR激动剂在几种偏头痛的啮齿动物模型中抑制偏头痛样反应， 预测治疗效果。其他数据还表明PN和NLRP 3的产生都参与了调解 偏头痛样伤害性反应。这是令人兴奋的，因为A3 AR激动剂已经在非疼痛的临床试验中， 这些药物具有良好的安全性，并且似乎非常适合慢性疼痛管理。基于这些 我们假设PN的产生及其下游伤害性信号级联的激活 参与偏头痛样头痛临床前模型的神经元和行为结果， 激动剂通过调节这种PN信号级联抑制这些结果。我们在目标1中的目标是验证 A3 AR作为偏头痛样头痛的新治疗靶点，使用经验证的急性和慢性头痛的临床前模型， 慢性偏头痛样头痛和既定的行为和电生理技术。我们还将 测量A3 AR沿着偏头痛通路的时间表达和定位。在目标2中，使用 药理学和遗传学的方法，与生化分析，我们将测试是否有益的影响， A3 AR激动剂的作用是通过抑制PN的产生和减弱翻译后 对参与伤害感受性神经递质神经传递的神经元和神经胶质蛋白的修饰， NLRP 3/IL-1β驱动的神经炎症。我们的研究结果有望为分子生物学提供新的见解。 偏头痛中与三叉神经血管激活相关的神经药理学重要的是，这些研究 验证A3 AR作为偏头痛治疗的新靶点，这将加速“概念验证”临床 研究，导致一个新的翻译努力在治疗偏头痛样头痛疾病。

Project Summary/Abstract Despite recent advances with new therapies, a huge proportion of migraine patients are still unable to use established therapeutics. For many patients, treatments are not effective, even newly approved CGRP mAbs have response rates of only ~50%. For others they are unsafe due to contraindications (triptans), or like opioids, not suited for long term use, even exacerbating existing migraine headache. This illustrates that there are still major gaps in our understanding of migraine mechanisms. It is therefore imperative that we investigate the underlying molecular mechanisms involved, geared towards identifying novel therapeutic targets with potential for rapid translation to the clinic. Recent data have identified the adenosine A3 receptor (A3AR) as a novel target for pain. Our recent work has also established that production of the highly noxious reactive nitroxidative species, peroxynitrite (PN), causes downstream modifications to glutamatergic signaling and NLRP3/IL-1β-driven neuroinflammation, to mediate nociceptive spinal sensitization. We show that A3AR agonists attenuate these nociceptive mechanisms in diverse rodent models of neuropathic pain, providing persistent pain relief. Despite this, little is known about A3AR-PN mechanisms in trigeminovascular migraine models. However, our preliminary data demonstrate that A3AR are expressed in important peripheral and central regions along the migraine pain pathway, and A3AR agonists inhibit migraine-like responses in several rodent models of migraine that are highly predictive of therapeutic efficacy. Additional data also implicate both PN and NLRP3 production in mediating migraine-like nociceptive responses. This is exciting as A3AR agonists are already in clinical trials in non-pain disorders, have a good safety profile, and appear well suited for chronic pain management. Based on these observations we hypothesize that PN production and activation of its downstream nociceptive signaling cascade is involved in neuronal and behavioral outcomes in preclinical models of migraine-like headache, and A3AR agonists inhibit these outcomes, via modulation of this PN signaling cascade. Our goal in Aim 1 will be to validate A3AR as a novel therapeutic target for migraine-like headache using validated preclinical models of acute and chronic migraine-like headache and established behavioral and electrophysiological techniques. We will also measure the temporal expression and localization of A3AR along the migraine pain pathway. In Aim 2, using pharmacological and genetic approaches, with biochemical analyses, we will test whether the beneficial effects of A3AR agonists are exerted through inhibition of PN production, and attenuation of post-translational modifications to neuronal and glial proteins involved in nociceptive glutamatergic neurotransmission and NLRP3/IL-1β-driven neuroinflammation. Our results are anticipated to provide novel insights into the molecular neuropharmacology related to dural-trigeminovascular activation in migraine. Importantly, these studies will validate A3AR as a novel target for migraine treatment, which should accelerate ‘proof-of-concept’ clinical studies, leading to a new translational effort in the treatment of migraine-like headache disorders.