脊髓水平SIRT2介导的小胶质细胞活化在瑞芬太尼诱发的术后痛觉过敏中的作用及机制研究

Remifentanil induced hyperalgesia limits its clinical applications and the mechanism of this hyperalgesia has not yet be clarified. The previous findings of our research group in remifentanil-induced hyperalgesia rat models certified the spinal activated microglia plays an important role in this process. Recent research indicated that the NAD-dependent deacetylase sirtuin 2(SIRT2) is a suppressor of microglial activation in central nervous system. This project intends to investigate the mechanism of remifentanil induced hyperalgesia by evaluating SIRT2-microglia in spinal cord. The effect of the SIRT2 active fragments, adenovirus vector, antagonists on microglia NF-κB and FOXO3a deacetylation and the inflammatory product were also evaluated in remifentanil induced hyperalgesia models. To clarify the mechanism of SIRT2-microglia participate in remifentanil-induced hyperalgesia. The implementation of this research would provide fundamental theory for the rational use of remifentanil in clinical and novel ideas for the treatment of remifentanil-indued hyperalgesia.

瑞芬太尼所致痛觉过敏限制了其临床应用，且迄今仍未阐明其机制。课题组的前期研究发现脊髓小胶质细胞的激活在瑞芬太尼所致的痛觉过敏中发挥重要作用。文献表明沉默信息调节因子2（SIRT2）是中枢小胶质细胞活化的抑制因子。本研究拟通过评价瑞芬太尼痛觉过敏模型中脊髓背角小胶质细胞及SIRT2变化，以及SIRT2活性碎片、腺病毒载体、抑制剂对小胶质细胞NF-κB和FOXO3a去乙酰化作用及炎性产物的影响，明晰小胶质细胞SIRT2参与瑞芬太尼所致痛觉过敏的机制，为临床治疗瑞芬太尼所致痛觉过敏提供新的思路。

瑞芬太尼可以加重患者术后痛觉过敏。小胶质细胞的活化在瑞芬太尼痛觉过敏中发挥重要作用。沉默信息调节因子2（sirt2）是中枢小胶质细胞活化的抑制因子。因此sirt2对小胶质细胞活化的调节对瑞芬太尼痛觉过敏影响值得探讨。本研究在大鼠切口痛模型泵注瑞芬太尼诱导瑞芬太尼痛觉过敏模型。通过鞘内分别给予sirt2的过表达病毒和抑制剂进行干预，观察大鼠痛行为学和小胶质细胞信号通路变化。我们发现瑞芬太尼会导致切口痛大鼠术后各时间点PWMT较单纯的切口痛组大鼠明显降低；鞘内注射sirt2过表达慢病毒可以明显缓解瑞芬太尼痛觉过敏；鞘内注射sirt2抑制剂Ak-7痛觉过敏加重。Western blot分析显示：瑞芬太尼切口痛组小胶质细胞活化（Iba1）表达明显增加，而sirt2蛋白表达减少；Ad-sirt2组sirt2蛋白表达增加，Iba1表达下降。免疫荧光结果显示:脊髓背角中存在sirt2表达，Iba1和sirt2存在共表达，瑞芬太尼切口痛组Iba1表达明显增加。细胞实验中发现瑞芬太尼可以导致小胶质细胞的活化（Iba1）表达增加，sirt2表达减少，乙酰化NF-κB增加，炎症因子TNF-α，IL-1β表达增加，乙酰化FOXO3增加，SOD2表达减少；与Ad-control组比较，sirt2过表达慢病毒能减少Iba1表达，增加sirt2表达，乙酰化NF-κB减少，炎症因子TNF-α，IL-1β表达减少，乙酰化FOXO3减少，SOD2表达增加。行为学结果与分子生物学结果相一致，说明瑞芬太尼可以导致痛觉过敏，可能是通过小胶质细胞的活化导致的，而sirt2在小胶质细胞活化的过程中发挥重要作用。