选择性调控AMPKα1及α2不同亚型实现能量再平衡治疗神经病理性疼痛

We hypothesize that energy imbalance induced by nerve damage may play crucial roles in the initiation and maintenance of neuropathic pain. And the neuropathic pain might be attenuated by achieving energy rebanlance. Here we speculate that aberrant activation of AMP-activated protein kinase(AMPK) would promote central sensitization and result in neuropathic pain. For the first time we found that AMPK might play pivitol role in neuropathic pain: (1) CCI injury induced AMPK activation in spinal cord and AMPK α1 and α2 Catalytic isoform shown cell type selective distribution;(2) AMPK inhibition or activation both significantly reduced hyperalgesia in CCI rats through distinct mechanisms. In this project we intend to further reveal the intracellular localization and variation of AMPK subtypes in different cell types of spinal cord during the process of neuropathic pain; to examine the activation mechanism and downstream signals of catalytic AMPK subtypes α1 /α2 in neurons, astrocytes and microglia, reapectively; to investigate the regulation of AMPK in different cells by LKB1, CaMKKβ and TAK1, which have been reported to be the upstream regulators of AMPK; and to eventually clarify the correlation between AMPK activation and neuropathic pain as well as the possibility of treat neuropathic pain by achieving energy rebalance through targeting AMPK.

申请人提出假说：神经损伤导致的能量失衡可能是神经病理性疼痛产生和维持的核心因素，主动促成能量的再平衡可以有效镇痛。我们的前期研究首次发现：细胞中的重要能量感受器和代谢调控子AMPK（磷酸腺苷激活的蛋白激酶）在神经损伤导致的疼痛敏化过程中发挥重要作用。神经损伤后，脊髓中的AMPKα1和α2催化亚型及活性显著上升并呈细胞选择性分布。抑制或者激活AMPK均可以镇痛，但是镇痛机制存在显著区别。本项目拟进一步研究神经病理性疼痛进程中，脊髓水平的神经元、胶质细胞中，α1/α2两种AMPK催化亚型各自的激活机制及下游的关键分子信号；重点考察AMPK的三个上游调控子：LKB1，CaMKKβ和TAK1对AMPK的调控是否具有细胞选择性和时空特异性；最终阐明能量应激导致的AMPK活化与神经病理性痛之间的相关性，并探讨选择性调控不同细胞类型中的AMPK亚型,通过主动促成能量的再平衡，治疗神经病理性疼痛的可行性。

神经损伤导致的能量失衡可能是神经病理性疼痛产生和维持的核心因素，主动促成能量的再平衡可以有效镇痛。重要结果：（1）我们构建了CCI和SNI诱导的慢性神经病理性疼痛，足底切口诱发的术后痛（PSP）和坐骨神经强直电刺激诱发的慢性痛模型（HFS）；（2）阐明 AMPK 及其下游分子在慢性疼痛发生发展过程中的变化及其调控作用；（3）阐明AMPK激动上调SOCS3对于神经炎症的改善作用；（4）臭氧能够显著激活AMPK，抑制MMP-9/2的活性，显著缓解神经病理性疼痛。科学意义：本项目在对神经痛机制研究的基础上，进一步探索了基于调节AMPK缓解神经痛的治疗手段，我们发现臭氧、原花青素以及白藜芦醇都具有显著的缓解神经痛的作用。为临床治疗神经病理性疼痛提供了非常好的基础研究成果。