Mechanisms of cannabinoid tolerance

项目总结/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： 确定大麻素耐受性是否通过激动剂特异性机制介导， 化疗诱导的神经性疼痛模型。我们的方法将检查对反- 三种大麻素的触诱发痛和抗伤害性效应 具有不同信号传导和化学特征的激动剂。在尾部对109-THC抗伤害感受的耐受性 用SP 600125预处理S426 A/S430 A突变体消除了甩动试验，SP 600125是一种选择性c-Jun N-末端激酶（JNK）抑制剂表明JNK（SP 600125抑制剂）和GRK/β抑制蛋白2 (S426/S430 A突变）信号传导机制协调介导对抗伤害感受性的耐受性。 9-THC的作用。本研究的第一个目标是全面系统地检验以下假设： 大麻素耐受性通过激动剂特异性机制介导。第二个目标是 测试JNK介导的对β 9-THC的耐受需要β-arrestin 2的存在的假设。的 第三个目标是检验β-arrestin 2和JNKs可以形成蛋白质-蛋白质相互作用的假设 in vivo.第四个目的是检验JNK可以直接磷酸化CB 1的假设， 使用技术创新的化学遗传方法，由109-THC激活。前三 将在化疗（顺铂）诱导的临床相关模型中检验假设， 神经性疼痛最后一个假设同样具有创新性，将提供重要信息 关于JNK介导的THC耐受性的分子作用机制。 本项目的首要目标是更好地了解激动剂的特异性机制 负责大麻素耐受性，这将促进持久，高度 有效和个性化的疼痛治疗。

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.