重复经颅磁刺激上调DJ-1表达改善小鼠创伤性脑损伤后功能障碍的研究

目的探讨重复经颅磁刺激（rTMS）对小鼠创伤性脑损伤（TBI）模型的神经功能障碍恢复及DJ-1表达的影响。 方法8~12周健康雄性C57BL/6J小鼠30只，采用随机数字表法分为Sham组（假手术组）、TBI组及rTMS组，每组10只。Sham组只开骨窗，不打击脑皮质；TBI组和rTMS组应用控制性皮层冲击损伤（CCI）模型，采用固定打击速度（3 m/s）、停留时间（200 ms）及打击深度（3.0 mm）的方法进行模型制备。模型制备后24 h对Sham组和rTMS组给予rTMS治疗（频率为1 Hz，每次持续25 s，5次/d，连续治疗14 d），TBI组治疗时放入关闭的线圈内。分别在治疗前后对小鼠进行神经功能缺损评分和行为学实验。治疗14 d后，采用苏木素-伊红（HE）染色观察组织病理学改变；采用免疫组织化学技术检测创伤灶周围区域神经元中DJ-1表达变化；采用TUNEL染色检测创伤区域细胞凋亡情况；采用Western blot检测DJ-1的蛋白水平表达变化。 结果创伤后7、14 d，TBI组和rTMS组的mNSS评分均显著高于Sham组，且rTMS组的mNSS评分低于TBI组，差异均具有统计学意义（P<0.05）。rTMS组的mNSS评分在创伤后14 d已降低至6分以下。行为学实验中，平衡木实验结果显示创伤后小鼠通过平衡木的时间显著增加，随着时间延长小鼠运动功能逐渐恢复，rTMS组小鼠通过平衡木的时间相较于TBI组明显缩短，差异均具有统计学意义（P<0.05）；转棒实验结果显示创伤后小鼠在转棒上停留的时间明显减少，随着时间延长停留时间逐渐增加，但rTMS组小鼠停留的时间明显多于TBI组，差异均具有统计学意义（P<0.05）。TBI模型小鼠脑组织病理学显示，脑创伤区域损伤明显，损伤灶局限并逐渐修复。与Sham组和TBI组相比，rTMS组DJ-1表达量显著增加，差异有统计学意义（P<0.05）。 结论rTMS可有效促进TBI小鼠神经功能的恢复和创伤灶的恢复，可能是由于rTMS促进了机体DJ-1的表达，使得神经功能缺损评分降低以及创伤面积减小。

Repeated transcranial magnetic stimulation up regulates DJ-1 expression and improves dysfunction after traumatic brain injury in mice

ObjectiveTo investigate the effects of repetitive transcranial magnetic stimulation (rTMS) on the recovery of neural dysfunction and the expression of DJ-1 in the model of traumatic brain injury (TBI) in mice. MethodsThirty healthy male C57BL/6J mice from 8 to 12 weeks were randomly divided into Sham group, TBI group and rTMS group, with 10 mice in each group. In Sham group, only bone window was opened without striking cerebral cortex; In TBI group and rTMS group, the controlled cortical impact injury (CCI) model was used, and the model was prepared by the methods of fixed strike velocity (3 m/s), residence time (200 ms) and strike depth (3.0 mm). At 24 h after model preparation, Sham group and rTMS group were treated with rTMS (frequency: 1 Hz, duration: 25 s, 5 times/d, continuous treatment: 14 d), and TBI group was put into the closed coil during treatment. The neurological deficit scores and behavioral tests were performed on mice before and after treatment. After 14 d of treatment, hematoxylin eosin (HE) staining was used to observe the histopathological changes; Immunohistochemical technique was used to detect the expression of DJ-1 in neurons around the trauma focus; TUNEL staining was used to detect apoptosis in the injured area; The protein expression of DJ-1 was detected by Western blot. ResultsAt 7 and 14 d after trauma, the mNSS scores in TBI group and rTMS group were significantly higher than those in Sham group, and the mNSS scores in rTMS group were lower than those in TBI group (P<0.05). The mNSS score of rTMS group decreased to below 6 at 14 d after trauma. In the behavioral experiment, the balance beam experiment results showed that the time for mice to pass the balance beam after trauma was significantly increased, and the motor function of mice gradually recovered with the extension of time. The time for mice in rTMS group to pass the balance beam was significantly shorter than that in TBI group, with statistically significant differences (P<0.05); The results of rod turning test showed that the time of mice staying on the rod was significantly reduced after trauma, and the time of mice staying on the rod was gradually increased with the prolongation of valve time. However, the time of mice staying in rTMS group was significantly longer than that in TBI group, and the difference was statistically significant (P<0.05). The brain histopathology of TBI model mice showed that the brain injury area was obviously damaged, the damage focus was limited and gradually repaired. Compared with Sham group and TBI group, the expression of DJ-1 in rTMS group was significantly increased (P<0.05). ConclusionrTMS can effectively promote the recovery of nerve function and trauma focal area in injured mice. It is speculated that rTMS can promote the expression of DJ-1 in the body, reduce the neurological deficit score and trauma area.