Mechanisms of cannabinoid tolerance

本研究将探讨大麻素耐受的机制。这一目标将会实现 通过确定大麻素耐受是否通过激动剂特异性机制来调节 使用化疗引起的神经病理性疼痛的模型。我们的方法将检查对 ∆-9-Thc、CP55、940和WIN55、212-2、3的抗痛觉过敏作用 具有明显信号和化学特征的大麻素激动剂。对∆9-THC的耐受性 用S426A/S430A突变体进行预处理，可消除甩尾试验中的抗伤害感觉 SP600125，一种选择性的c-jun氨基末端激酶(JNK)抑制剂，提示JNK(SP600125) 抑制物)和GRK/β抑制素2(S426/S430A突变)信号机制协调调节 对∆-9-Thc抗伤害作用的耐受性。这项研究的第一个目标是，充分和 系统地测试大麻素耐受是通过激动剂特异性介导的假设 机械装置。第二个目标是检验JNK介导的对∆9-Thc耐受性的假设 要求存在β−逮捕2。第三个目标是检验这样一种假设，即β−逮捕蛋白2和 JNKs在体内可以形成蛋白质-蛋白质相互作用。第四个目标是检验假设 当被∆9-THC激活时，JNKs可以直接磷酸化CB1，使用一种创新的技术 化学遗传学方法。前三个假设将在一个临床相关的模型中进行验证 化疗(顺铂)诱导的神经病理性疼痛模型。最后一个假设也是一样的 并将提供有关分子作用机制的重要信息 负责JNK介导的∆-9-Thc耐受。这个项目的首要目标是获得一个 更好地了解导致大麻素耐受的激动剂特异性机制 将促进长效、高效和个性化疼痛疗法的发展。

This study will investigate the mechanisms of cannabinoid tolerance. This objective will be achieved by determining whether cannabinoid tolerance is mediated through agonist-specific mechanisms using a model of chemotherapy-induced neuropathic pain. Our approach will examine tolerance to the anti-allodynic and antinociceptive effects of ∆9-THC, CP55,940, and WIN55,212-2, three cannabinoid agonists with distinct signaling and chemical features. Tolerance to ∆9-THC antinociception in the tail-flick test was eliminated by pre-treatment of S426A/S430A mutants with SP600125, a selective c-Jun N-terminal kinase (JNK) inhibitor suggesting that JNK (SP600125 inhibitor) and GRK/βarrestin2 (S426/S430A mutation) signaling mechanisms coordinate to mediate tolerance to the antinociceptive effect of ∆9-THC. The first objective of this study is to, fully and systematically, test the hypothesis that cannabinoid tolerance is mediated through agonist-specific mechanisms. The second objective is to test the hypothesis that JNK-mediated tolerance for ∆9-THC requires the presence of β−arrestin2. The third objective is to test the hypothesis that β−arrestin2 and JNKs can form protein-protein interactions in vivo. The fourth objective is to test the hypothesis that JNKs can directly phosphorylate CB1 when activated by ∆9-THC using a technologically innovative chemical-genetic approach. The first three hypotheses will be tested in a clinically relevant model of chemotherapy (cisplatin)-induced model of neuropathic pain. The last hypothesis is equally innovative and will provide important information regarding the molecular mechanism of action that is responsible for JNK-mediated ∆9-THC tolerance. The overarching goal of this project is to gain a better understanding of the agonist-specific mechanisms responsible for cannabinoid tolerance that will facilitate the development of long lasting, highly efficacious, and personalized pain therapies.