Neuroligin/Neurexin—Kalirin-7介导突触重塑在瑞芬太尼痛觉过敏中的调控机制

Remifentanil-induced hyperalgesia seems more frequently and predictably when compared with other opioids, but its mechanism remains elusive. Our previous study has published in Anesthesiology and manifested that postoperative kalirin-7 mediated synaptogenesis is involved in remifentanil-induced hyperalgesia. Recent studies have reported that Neuroligin-1/Neurexin-1α is critical for central glutaminergic excitatory synapsic plasticity. We hypothesize that Neuroligin-1/Neurexin-1α—Kalirin-7 pathway may exert a pivotal effect on remifentanil-induced hyperalgesia. Therefore in this study, following accomplishment of a rat model of remifentanil-induced postoperative hyperalgesia, we use nociceptive behavior test, Western blot, coimmunoprecipitation, immunofluorescence and Golgi staining to detect dynamic changes of Neuroligin-1、Neurexin-1α、Kalirin-7 and dendritic spines morphology in remifentanil-induced hyperalgesia. We also culture rat primary spinal dorsal horn neurons, and employ Neuroligin-1-siRNA to demonstrate the molecular pathogenesis of synaptic plasticity in remifentanil-induced hyperalgesia. The present study will provide the novel options for the effective prevention of hyperalgesia induced by remifentanil in clinics.

瑞芬太尼痛觉过敏临床常见，其机制尚不明确。课题组前期工作(发表于Anesthesiology)证实术后kalirin-7调节突触形成与瑞芬太尼痛敏密切相关。新近研究发现Neuroligin-1/Neurexin-1α是谷氨酸能兴奋性神经突触重塑的关键，故推测Neuroligin-1/Neurexin-1α—Kalirin-7通路可能是介导瑞芬太尼痛敏的重要机制。本研究拟建立在体SD大鼠瑞芬太尼痛敏模型，利用痛敏行为学测定、Western blot、共沉淀、荧光和高尔基染色研究Neuroligin-1、Neurexin-1α、Kalirin-7和树突棘形态在瑞芬太尼痛敏中的动态变化；体外培养大鼠脊髓背角神经元，应用Neuroligin-1-siRNA转染技术研究突触重塑分子机制在瑞芬太尼痛敏中的调控作用。本研究将为瑞芬太尼痛敏现象的临床防治提供新思路。

瑞芬太尼是超短效μ-阿片受体激动剂，广泛用于外科手术全身麻醉的镇痛，其引发的痛觉过敏（OIH）现象发生普遍。课题组前期工作(发表于Anesthesiology)证实术后kalirin-7调节突触形成与瑞芬太尼痛敏密切相关。新近研究发现Neuroligin-1/Neurexin-1α是谷氨酸能兴奋性神经突触重塑的关键，故推测Neuroligin-1/Neurexin-1α—Kalirin-7通路可能是介导瑞芬太尼痛敏的重要机制。本研究制作大鼠在体瑞芬太尼痛敏模型，利用痛敏行为学测定、Western blot、免疫共沉淀、荧光和高尔基染色，完成了Neuroligin-1、Neurexin-1α、Kalirin-7、GluR1和树突棘形态在瑞芬太尼痛敏中动态变化的检测；并体外培养大鼠脊髓片和背角神经元，利用Neuroligin-1小干扰RNA以及全细胞膜片钳技术研究Neuroligin-1/Neurexin-1α—Kalirin-7在瑞芬太尼痛敏突触重塑分子机制中的调控作用。研究发现瑞芬太尼诱发痛敏大鼠脊髓背角中Neuroligin-1、Neurexin-1α和Kalirin-7表达增高，活性增强；脊髓总蛋白、膜蛋白中GluR1亚基表达增高，同时GluR1膜上位上调；痛敏大鼠脊髓背角树突棘增大，成熟树突棘数量增加，功能性突触形成；应用Neuroligin-1慢病毒转染及GluR1拮抗剂可有效抑制脊髓背角神经元树突棘结构重塑，降低瑞芬太尼诱发痛敏程度，缩短痛敏持续时间；瑞芬太尼孵育后可增加脊髓背角神经元AMPA受体介导的mEPSC的振幅和频率，诱发C纤维LTP形成，而抑制Neuroligin-1/Neurexin-1α—Kalirin-7可有效削弱这一效应。本项目在国内外发表论文16篇, 其中SCI 10篇。本研究以突触重塑作为切入点，从整体水平出发，通过在体和离体实验，系统探讨并阐明Neuroligin-1/Neurexin-1α — Kalirin-7信号通路在瑞芬太尼引发痛觉过敏形成中的调控机制，为临床合理有效地防治瑞芬太尼引发痛敏提供新的靶点。