摘要目的 探讨大麻素CB2受体激动剂AM1241预处理对联用脂多糖(LPS)和γ-干扰素(IFN-γ)所致小胶质细胞活化和损伤的影响.方法 选择小鼠小胶质细胞进行实验,细胞分为对照组、AM1241组、LPS/IFN-γ组和AM1241+LPS/IFN-γ组.对照组细胞正常培养;AM1241组细胞经AM1241预处理2 h后正常培养;LPS/IFN-γ组细胞用含1 μg/mL LPS和50 U/mL,IFN-γ的培养基培养24 h;AM1241+LPS/IFN-γ组细胞经AM1241预处理2 h后,更换正常培养基培养2 h,最后用含1 μg/mL LPS和50 U/mL IFN-γ的培养基培养24 h.采用MTT法检测细胞代谢率,NO检测试剂盒检测细胞培养液中NO释放量,倒置相差显微镜观察细胞形态.结果 AM1241+LPS/IFN-γ组细胞代谢率为92.55%±8.37%,明显高于LPS/IFN-γ组(75.04%±3.01%),差异有统计学意义(P<0.05).AM1241+LPS/IFN-γ组细胞培养基中NO浓度为(43.44±5.52) μmol/L,明显低于LPS/IFN-γ组[(90.87±4.28)μmol/L],差异有统计学意义(P<0.05).LPS/IFN-γ组大量细胞结构被破坏,胞体增大,伪足增粗、变短或消失;AM1241+LPS/IFN-γ组少量细胞结构被破坏,胞体稍增大,伪足较明显.结论 大麻素CB2受体激动剂AM1241预处理可减轻联用LPS和IFN-γ所致的小胶质细胞活化和损伤.

abstractsObjective To investigate the effect of preconditioning with cannabinoid CB2 receptor agonist AM1241 on microglial activation and injury induced by lipopolysaccharide ( LPS) and interferon-γ (IFN-γ). Methods The microglial cells were chosen and assigned to control group,AM1241 treatment group, LPS/IFN-γ inducement group and AM1241+LPS/IFN-γ treatment group. Cells of control group were cultured in normal medium;cells of AM1241 treatment group were preconditioned with AM 1241 for 2 h, and then the medium was changed with normal medium;cells of LPS/IFN-γ inducement group were exposed to the medium containing 1 μg/mL LPS plus 50 U/mL IFN-γ for 24 h;cells of AM1241+LPS/IFN-γ treatment group were preconditioned with AM1241, then the medium were changed with normal medium for 2 h, and at last, cells of this group were exposed to 1 μg/mL LPS plus 50 U/mL IFN-γ for 24 h. Microglial metabolism was assessed by MTT assay;NO release was measured by Reagent Kit;microglial shapes were observed through microscope. Results CB2 receptor agonist preconditioning can up-regulate the microglial CB2 receptor expression markedly;cell metabolism of AM1241+LPS/IFN-γ treatment group (92.55 ±8.37%) was obviously higher than that of LPS/IFN-γ inducement group (75.04±3.01%, P<0.05);AM1241+LPS/IFN-γ treatment group (43.44±5.52 μmol/L) released significantly less NO than LPS/IFN-γ inducement group (90.87±4.28 (μmol/L, P<0.05). Cells of the LPS/IFN-γ inducement group were destroyed seriously with enlarged soma and thickened and shortened pseudopodium;cells of the AM1241+LPS/IFN-γ treatment group were destroyed slightly with slightly enlarged soma and thickened and shortened pseudopodium. Conclusion Preconditioning with cannabinoid CB2 receptor agonist AM1241 reduces microglial activation and injury induced by LPS plus IFN-γ.