Objectives: To investigate the effects on the motor function, cortex blood flow perfusion, microglial cells, and the contents of serum inflammatory factors, i.e. interleukin-1β (IL-1β), transforming growth factor-β (TGF-β), and interleukin-10 (IL-10) after electroacupuncture (EA) preconditioning at "Baihui" (GV20) and "Dazhui" (GV14) in the mice with ischemic stroke, so as to explore the mechanism of EA preconditioning for improving motor function after ischemic stroke.
Methods: C57BL/6 mice were randomly divided into sham-operation group, model group, and EA preconditioning group (EA group), with 15 mice in each group. A photothrombotic method was used to induce the model of unilateral ischemic stroke and motor impairment. The mice in the EA group received EA preconditioning, 20 min each time, once daily for 7 consecutive days before modeling. The motor function of mice was evaluated by the grid-walking test and cylinder test before and after modeling. Laser speckle blood flow video monitoring system was employed to assess the cerebral blood flow perfusion in the primary motor cortex of mice. The contents of IL-1β, TGF-β, and IL-10 in the serum were measured by ELISA, and the expressions of microglial cell and M2 subtype cell marker in the primary motor cortex were detected using immunofluorescence staining.
Results: After modeling, compared with the sham-operation group, the grid error rate and the dragging rate of the affected limb were increased (P<0.01)；the utilization rate of the affected limb and percentage of the blood perfusion in the affected cortex to healthy side were decreased (P<0.01)；the contents of serum IL-1β, TGF-β, and IL-10 were increased (P<0.01, P<0.05)；and the microglia in the primary motor cortex on the affected side showed ameboid, the fluorescence intensity of ionized calcium-binding adapter molecule 1 (IBA1) and CD206 was increased (P<0.01) in the model group. In the EA group, when compared with the model group, the grid error rate and the dragging rate of affected limb were decreased (P<0.01)；the utilization rate of affected limb and the percentage of blood perfusion were increased (P<0.05)；the content of serum IL-1β was decreased (P<0.01), while the contents of TGF-β and IL-10 were increased (P<0.01)；and the microglia in the primary motor cortex on the affected side got more round and were distributed more densely, the fluorescence intensity of IBA1 and CD206 was increased (P<0.01).
Conclusions: Electroacupuncture preconditioning at "GV20" and "GV14" can up-regulate the expression of microglial cells, especially the M2 subtype cell marker, and increase the contents of the anti-inflammatory factors and decrease that of the pro-inflammatory factors in the serum, thereby alleviate the inflammatory reaction.
目的: 观察电针预处理“百会”“大椎”对缺血性中风小鼠运动功能、脑皮层血流灌注、小胶质细胞和血清炎性因子白细胞介素1β（IL-1β）、转化生长因子β（TGF-β）、白细胞介素10（IL-10）含量的影响，探讨电针预处理改善缺血性中风后运动功能的机制。方法: C57BL/6小鼠随机分为假手术组、模型组、电针预处理组（电针组），每组15只。光栓诱导构建单侧缺血性卒中运动障碍模型。电针组小鼠在造模前进行连续7 d的电针“百会”“大椎”预处理，每次20 min，每天1次。用网格实验和爬杯实验评价小鼠造模前后运动功能；激光散斑血流监测视频系统评估小鼠初级运动皮层血流灌注量；ELISA法检测小鼠血清IL-1β、TGF-β、IL-10的含量；免疫荧光染色法检测小鼠初级运动皮层小胶质细胞及其M2亚型细胞标记物的表达。结果: 造模后，与假手术组比较，模型组小鼠网格错误率、患肢拖拽率升高（P<0.01），患肢利用率及患侧占健侧皮层血流灌注量百分比降低（P<0.01）；血清IL-1β、TGF-β、IL-10含量升高（P<0.01，P<0.05）；患侧初级运动皮层小胶质细胞呈阿米巴样，离子钙接头蛋白分子1（IBA1）和CD206荧光强度升高（P<0.01）。与模型组比较，电针组小鼠网格错误率、患肢拖拽率降低（P<0.01），患肢利用率及患侧与健侧血流灌注量百分比升高（P<0.05）；血清IL-1β含量降低（P<0.01），TGF-β、IL-10含量升高（P<0.01）；患侧初级运动皮层小胶质细胞胞体较模型组更圆、更密集，IBA1和CD206荧光强度升高（P<0.01）。结论: 电针预处理“百会”“大椎”可提高梗死局部小胶质细胞尤其是M2亚型标记物的表达，提高血清抗炎因子含量及降低促炎因子含量，从而减轻炎性反应。.
Keywords: Electroacupuncture preconditioning; Inflammatory response; Ischemic stroke; Microglial cells.