神经钙蛋白作为治疗癌性骨痛新靶点的研究

Calcineurin play various roles in modulating nociception on intracellular-nucleus sensory signaling pathway. Its most important downstream transcription factor is NFAT. NFAT was upregulated in rats neuropathic pain model of spinal nerve ligation and inhibition of the upregulation of NFAT attenuated the tactile allodynia. These findings suggest that NFAT was involved in the pathogenesis of neuropathic pain. Cancer-induced bone pain pathogenesis is still not clear and clinical treatment is very difficult. There was not any report about that whether the calcineurin was involved in the pathogenesis of cancer-induced bone pain or not, even calcineurin was the most important upstream regulatory proteins of NFAT. Our preliminary results showed that intrathecal injection of calcineurin inhibitor can alleviate the cancer-induced bone pain. Therefore, it is possible for calcineurin to be a new target for the treatment of cancer-induced bone pain. In this study, we examine the expression of calcineurin and NFAT in PAG, spinal cord and DRG under cancer-induced bone pain. Next we explore the antinociception of the inhibitor of calcineurin or inhibitor of NFAT against cancer-induced bone pain. We also evaluate the relationship between calcineurin or NFAT with MAPKS signaling pathways and pain-related inflammatory factors under cancer-induced bone pain. We still explore the interaction between calcineurin inhibitor or NFAT inhibitor with opioids, local anesthetics, NMDA receptor antagonists, NSAIDs in the treatment of cancer-induced bone pain. It will provide a new target and theoretical for the clinical treatment of cancer-induced bone pain.

神经钙蛋白是参与胞内胞核感觉信号传递通路的蛋白，其最主要的下游调控作用因子是NFAT。最近的研究发现NFAT在大鼠神经病理性疼痛中表达上调，抑制NFAT上调能够有效减轻其机械性异常疼痛，提示NFAT参与神经病理性疼痛的发病机制。癌性骨痛发病机理复杂,治疗效果不理想。神经钙蛋白是NFAT最重要上游调控蛋白，是否参与癌性骨痛的发病机制，未见报道。我们的前期研究发现，神经钙蛋白抑制剂能减轻大鼠的癌性骨痛，我们期待神经钙蛋白能够成为治疗癌性骨痛的新靶点。本研究采用免疫组化,Western Blot,PCR检测大鼠癌性骨痛中，大脑PAG，脊髓和DRG神经钙蛋白和NFAT的表达变化情况，研究两者对胞内MAPKs信号通路和疼痛相关炎性因子的影响，探讨神经钙蛋白和NFAT的抑制剂与阿片类药物,局麻药,NMDA受体拮抗剂，NSAIDs药物之间治疗癌性骨痛的相互作用，为临床治疗癌性骨痛提供新的靶点和理论依据。

神经病理性疼痛是临床上常见的现象，常见的病因有神经损伤、化疗药物和晚期癌痛。本项目研究神经病理性疼痛的发病机制，寻找有效的治疗手段。..本项目研究内容包括神经钙蛋白在神经病理性疼痛发病机制中的作用，以及炎性因子和趋化因子在神经病理性疼痛中的作用及其调节机制。..本研究的重要结果有（1）大鼠神经病理性疼痛（腰5脊神经前跟切断，L5-VRT）引起DRG 中神经钙蛋白表达下调，并抑制IL-10释放。上调Calcineurin能够有效的上调IL-10并缓解L5-VRT引起的疼痛，临床上使用的乌司他丁能够有效的逆转L5-VRT引起的神经钙蛋白下调，并上调IL-10的表达从而发挥抗神经病理性疼痛的作用。（2）鞘内注射注射阿米洛利缓解福尔马林炎性疼痛和L5脊神经结扎引起的神经病理性疼痛现象，该作用主要与阿米洛利抑制脊髓背角c-fos表达和p38磷酸化有关。（3）神经损伤或化疗药物诱导的神经病理性疼痛后，通过上调脊髓背角miRNA-500靶向调节GAD67基因的特异性位点调控GAD67的蛋白表达，降低的GAD67通过损伤脊髓背角GABA能的突触功能，介导痛觉过敏。（4）化疗药物硼替佐米通过上调脊髓背根神经节神经元ATF3表达，促进c-Jun与CCL2基因启动区相结合，上调趋化因子CCL2表达介导痛觉过敏。（5）研究发现脊髓运用小剂量的奥沙利铂能够诱导出急性的机械性异常疼痛和热痛觉过敏，单次静脉注射奥沙利铂后脑脊液中奥沙利铂的浓度显示出时间依赖性增加，并显著增加NFB-P65和组蛋白乙酰化酶H4在CX3CL1蛋白启动区域的结合，上调CX3CL1的表达，参与急性病理性疼痛和脑病的发病。..关键数据是神经钙蛋白在神经病理性疼痛中发挥重要作用，神经钙蛋白有希望成为治疗病理性疼痛的一个靶点。其科学意义在于能够为临床防治不同类型的神经病理性疼痛提供靶点和理论依据。