Mechanisms of cannabinoid tolerance

项目摘要/摘要 本研究将探讨大麻素耐受的机制。这一目标将通过以下方式实现 确定大麻素耐受是否是通过激动剂特异性机制介导的 化疗所致神经病理性疼痛模型。我们的方法将检查对反 ∆9-Thc、CP55、940和WIN55、212-2三种大麻素的痛觉异常和抗伤害作用 具有不同信号和化学特征的激动剂。尾部对∆9-THc的耐受性 用选择性c-jun基因SP600125对S426A/S430A突变体进行预处理，消除了轻弹试验 N-末端激酶(JNK)抑制剂提示JNK(SP600125抑制剂)和GRK/β抑制蛋白2 (S426/S430A突变)信号机制协调调节对抗伤害性药物的耐受 ∆-9-Thc的作用。这项研究的第一个目标是，全面和系统地检验这一假设 大麻素耐受是通过激动剂特有的机制来调节的。第二个目标是 测试JNK介导的对∆9-Thc的耐受需要存在β−抑制蛋白2的假设。这个 第三个目标是验证β−-arrestin2和JNKs可以形成蛋白质-蛋白质相互作用的假设 在活体内。第四个目标是检验JNKs在以下情况下可以直接磷酸化CB1的假设 由∆9-THC使用技术创新的化学遗传方法激活。前三名 假说将在临床相关的化疗(顺铂)诱导的模型中得到验证。 神经性疼痛。最后一种假设同样具有创新性，将提供重要信息。 关于JNK介导的∆9-Thc耐受的分子作用机制。 这个项目的首要目标是更好地了解激动剂的特定机制。 对大麻素的耐受性负责，这将促进长效、高度 有效的、个性化的疼痛疗法。

Project Summary/Abstract 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.