紫云英苷对脊髓背角小胶质细胞P2X4受体介导神经病理痛的作用研究

Neuropathic pain refers to the pain syndrome caused by nervous system injury or illness. It seriously affects the physical and mental health of patients. Due to the pathogenesis of neuropathic pain is very complex, so far there is no effective drug to remove pain. Therefore, to explore the treatment drugs of neuropathic pain and its mechanism is particularly important. ATP released by the injured tissue activated purine 2X4 (P2X4) receptor has been reported to participate in the transmission of pain information. Astragalin, as a traditional Chinese medicine (TCM), has anti-inflammatory, anti-oxidant and other pharmacological effects. Previous studies showed that astragalin can reduce pain behaviors of neuropathic pain model rats. Molecular docking indicated that astragalin is docked with the P2X4 receptor (score 7.2). Previous studies suggest that astragalin could be used to reduce the pain behavior of neuropathologic pain rats by acting on the P2X4 receptor. In this project, neuropathy pain rat model induced by chronic constriction injury(CCI) will be used. The application of nano materials of drug / gene targeted drug delivery method, combined with optical pharmacogenetics, calcium imaging, patch clamp technique, we observe the effect of astragalin (or nanomaterials astragalin with P2X4 shRNA), on P2X4 receptor in the spinal dorsal horn microglia and satellite glial cells in dorsal root ganglia mediated neuropathic pain and its possible mechanism.

神经病理性疼痛是指由神经系统损伤或疾病所引起的疼痛综合征，严重影响患者的身心健康。由于神经病理性疼痛的发病机制复杂，至今无有效的治疗药物。因此，探索治疗神经病理痛的药物及其作用机制显得尤为重要。损伤组织释放的ATP激活嘌呤P2X4受体参与痛觉信息的传递。紫云英苷具有抗炎、抗氧化等药理作用。前期研究发现紫云英苷处理后可降低神经病理痛模型大鼠的热痛敏和机械痛敏，分子对接显示紫云英苷可与P2X4受体结合（得分为-7.2），提示紫云英苷可能作用于P2X4受体产生效应。本项目应用坐骨神经慢性压迫性损伤神经病理性疼痛大鼠模型，应用纳米材料性药物/基因协同靶向给药方法，结合光遗传药理学、钙离子成像、膜片钳等技术，观察紫云英苷（或纳米材料载紫云英苷与P2X4受体shRNA合用）处理，对脊髓背角小胶质细胞和背根神经节卫星胶质细胞P2X4受体介导神经病理性疼痛的作用及可能机制。

神经病理性疼痛是指由神经系统损伤或疾病所引起的疼痛综合征，严重影响患者的身心健康。由于神经病理性疼痛的发病机制复杂，至今无有效的治疗药物。因此，探索治疗神经病理痛的药物及其作用机制显得尤为重要。本项目研究紫云英苷在脊髓背角（SDH）及背根神经节（DRG）胶质细胞P2X4受体介导的神经病理痛中的作用及可能机制。本项目研究发现：一、坐骨神经压慢性压迫性损伤（CCI）大鼠机械痛及热痛行为增强，背根神经节卫星胶质细胞P2X4受体表达增加，而应用P2X4受体选择性拮抗剂5-BDBD可减轻大鼠的痛行为，且发现ERK1/2信号通路的激活参与P2X4受体介导的神经病理痛。此研究结果表明DRG中P2X4受体参与CCI所致的神经病理痛过程。二、CCI大鼠应用紫云英苷后，抑制CCI诱导的DRG卫星胶质细胞及SDH小胶质细胞中P2X4受体表达的上调，抑制卫星胶质细胞和小胶质细胞的激活及磷酸化ERK1/2激活，从而减轻了CCI大鼠的痛行为。此研究结果表明，紫云英苷通过抑制P2X4受体及胶质细胞的激活而缓解CCI诱导的神经病理痛大鼠痛行为。三、CCI合并抑郁大鼠海马P2X4受体上调，海马P2X4受体可能通过激活小胶质细胞发挥作用及NLRP3炎症小体级联反应产生大量的IL-1β，导致海马神经元损伤，从而引起模型大鼠出现异常疼痛及抑郁样行为。而应用5-BDBD后细胞焦亡相关蛋白表达下降，缓解大鼠的痛行为及抑郁样表现。此结果表明P2X4受体可能通过小胶质细胞激活及细胞焦亡途径参与了疼痛和抑郁共病的病理过程。本项目的研究为神经病理性疼痛的预防和治疗提供了新的实验依据。