Ht31 peptide inhibited inflammatory pain by blocking NMDA receptor-mediated nociceptive transmission in spinal dorsal horn of mice
Ht31 peptide inhibited inflammatory pain by blocking NMDA receptor-mediated nociceptive transmission in spinal dorsal horn of mice
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DOI：
10.1016/j.neuropharm.2014.09.031
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发表时间：
2015-02
影响因子：
4.7
通讯作者：
Wen-tao Wang;Guoyan Pan;Zi-Yang Zhang;Zhanwei Suo;Xian Yang;Xiao-Dong Hu
中科院分区：
文献类型：
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作者：
Wen-tao Wang;Guoyan Pan;Zi-Yang Zhang;Zhanwei Suo;Xian Yang;Xiao-Dong Hu
激酶锚定蛋白(AKAPs)将cAMP依赖的蛋白激酶(PKA)组装成具有多种离子通道的信号复合体，包括N-甲基-d-天冬氨酸(NMDA)-亚型谷氨酸受体(NMDAR)，它在中枢敏化伤害性行为中起关键作用。虽然PKA在依赖NMDAR的伤害性传递和可塑性的调控中已被广泛描述，但AKAP在这些过程中的作用目前还不清楚。本研究通过将硬脂化Ht31肽(ST-Ht31)引入脊髓背角神经元，干扰AKAPs/PKA的相互作用，并观察初级传入诱发的NMDAR介导的兴奋性突触后电流(NMDAR-EpSCs)的可能变化。全细胞膜片钳记录表明，通过玻璃吸管的细胞内负载ST-Ht31不影响NMDAR介导的完整小鼠脊髓切片的突触反应。然而，当足底注射完全弗氏佐剂(CFA)建立炎性疼痛时，ST-Ht31通过选择性地将含有GluN2B亚单位的NMDAR从突触中移除，显著抑制了NMDAR-EPSCs的幅度。ST-Ht31通过抑制NMDAR介导的伤害性信息传递，有效地减轻CFA诱导的炎性疼痛。通过对微管NMDAR转运、动力蛋白依赖的NMDAR内吞或肌动蛋白解聚的药理作用，ST-Ht31肽对NMDAR-EPSCs的抑制作用消失，提示ST-Ht31阻断AKAP/PKA相互作用可能干扰NMDAR转运的多个步骤，从而减少受体突触的表达和脊髓的敏化。
A kinase anchoring proteins (AKAPs) assemble cAMP–dependent protein kinase (PKA) into signaling complexes with a wide range of ion channels, including N-methyl-d-aspartate (NMDA)-subtype glutamate receptor (NMDAR) that is critical for the central sensitization of nociceptive behaviors. Although PKA has been widely described in the regulation of NMDAR-dependent nociceptive transmission and plasticity, the roles of AKAPs in these processes are largely unknown as yet. The present study interfered with AKAPs/PKA interaction by introducing stearated Ht31 peptide (St-Ht31) into spinal dorsal horn neurons, and investigated the possible changes of primary afferent-evoked, NMDAR-mediated excitatory postsynaptic currents (NMDAR-EPSCs). Whole-cell patch clamp recordings demonstrated that intracellular loading of St-Ht31 through the glass pipettes didn't affect NMDAR-mediated synaptic responses in the spinal cord slices from intact mice. When inflammatory pain was established by intraplantar injection of Complete Freund's Adjuvant (CFA), however, St-Ht31 significantly repressed the amplitudes of NMDAR-EPSCs by selectively removing GluN2B subunit-containing NMDAR out of synapses. With the inhibition of NMDAR-mediated nociceptive transmission, St-Ht31 effectively ameliorated CFA-induced inflammatory pain. Pharmacological manipulation of microtubule-based NMDAR transport, dynamin-dependent NMDAR endocytosis or actin depolymerization abolished the inhibitory effects of St-Ht31 peptide on NMDAR-EPSCs, suggesting that disruption of AKAPs/PKA interaction by St-Ht31 might disturb multiple NMDAR trafficking steps to reduce the receptor synaptic expression and spinal sensitization.