*Laboratory of Neuroimmunology and Developmental Origins of Disease, University Medical Center Utrecht, Utrecht, The Netherlands.
†Departamento de Biología Molecular and Centro de Biología Molecular "Severo Ochoa" UAM-CSIC, Madrid, Spain.
Biochem J. 2014 May 1;459(3):427-39. doi: 10.1042/BJ20130172.
The MAPK (mitogen-activated protein kinase) p38 is an important mediator of inflammation and of inflammatory and neuropathic pain. We have described recently that docking-groove-dependent interactions are important for p38 MAPK-mediated signal transduction. Thus virtual screening was performed to identify putative docking-groove-targeted p38 MAPK inhibitors. Several compounds of the benzo-oxadiazol family were identified with low micromolar inhibitory activity both in a p38 MAPK activity assay, and in THP-1 human monocytes acting as inhibitors of LPS (lipopolysaccharide)-induced TNFα (tumour necrosis factor α) secretion. Positions 2 and 5 in the phenyl ring are essential for the described inhibitory activity with a chloride in position 5 and a methyl group in position 2 yielding the best results, giving an IC₅₀ value of 1.8 μM (FGA-19 compound). Notably, FGA-19 exerted a potent and long-lasting analgesic effect in vivo when tested in a mouse model of inflammatory hyperalgesia. A single intrathecal injection of FGA-19 completely resolved hyperalgesia, being 10-fold as potent and displaying longer lasting effects than the established p38 MAPK inhibitor SB239063. FGA-19 also reversed persistent pain in a model of post-inflammatory hyperalgesia in LysM (lysozyme M)-GRK2 (G-protein-coupled-receptor kinase)(+/-) mice. These potent in vivo effects suggested p38 MAPK docking-site-targeted inhibitors as a potential novel strategy for the treatment of inflammatory pain.
丝裂原活化蛋白激酶（MAPK）p38 是炎症和炎症性及神经性疼痛的重要介质。我们最近描述了，对接沟依赖性相互作用对 p38 MAPK 介导的信号转导很重要。因此，进行了虚拟筛选以鉴定潜在的对接沟靶向 p38 MAPK 抑制剂。在 p38 MAPK 活性测定中，以及在作为脂多糖（LPS）诱导的 TNFα（肿瘤坏死因子α）分泌抑制剂的 THP-1 人单核细胞中，几种苯并恶二唑家族的化合物均表现出低微摩尔的抑制活性。苯环中的 2 位和 5 位对于描述的抑制活性是必需的，其中 5 位的氯和 2 位的甲基产生最佳结果，IC₅₀ 值为 1.8 μM（FGA-19 化合物）。值得注意的是，在炎症性痛觉过敏的小鼠模型中测试时，FGA-19 体内表现出强大而持久的镇痛作用。单次鞘内注射 FGA-19 可完全缓解痛觉过敏，其效力比已建立的 p38 MAPK 抑制剂 SB239063 强 10 倍，作用持续时间更长。FGA-19 还逆转了 LysM（溶菌酶 M）-GRK2（G 蛋白偶联受体激酶）（+/-）小鼠炎症后痛觉过敏模型中的持续性疼痛。这些强大的体内作用表明，p38 MAPK 对接位点靶向抑制剂可能成为治疗炎症性疼痛的一种新策略。
