Qiu Rong-Rong, Zhang Hong, Deng Chang, Chen Dan-Feng, Xu Ya-Yu, Xiong Dan, Zou Ying-Jie, Tan Jie
College of Acupuncture-moxibustion and Tuina, Hunan University of Chinese Medicine,Changsha 410208, China.
Zhen Ci Yan Jiu. 2022 Apr 25;47(4):298-304. doi: 10.13702/j.1000-0607.20210324.
To observe the effect of electroacupuncture (EA) on learning-memory ability, ultrastructural changes of hippocampal CA1 neurons, reactive oxygen species (ROS) level, Nod-like receptor protein 3 (NLRP3) and auto-phagy-related proteins expression in the hippocampus of vascular dementia (VD) rats, so as to reveal its partial mechanisms in treating VD.
Male SD rats were randomly divided into sham operation, model, and EA groups (=10 rats in each group). The VD model was established by permanent ligation of bilateral common carotid arteries. Rats of the EA group were treated with EA at "Baihui" (GV20), "Dazhui" (GV14) and bilateral "Shenshu" (BL23) for 30 min, once a day for 4 weeks. Morris water maze was used to evaluate the learning and memory ability of rats before modeling, 4 weeks after modeling and after intervention. Transmission electron microscopy (TEM) was used to observe the ultrastructural changes of hippocampal CA1 neurons. The level of ROS in hippocampus was detected by DCFH-DA fluorescence probe. The expressions of NLRP3, autophagy-related protein Beclin1 and microtubule-associated protein 1 light chain 3 (LC3) were measured by Western blot.
In comparison with the sham operation group, the average escape latency of rats in the model group was prolonged (<0.01), and the times of crossing the original platform were reduced (<0.05), the level of ROS, the expression levels of LC3-Ⅱ/LC3-Ⅰ ratio, Beclin1 and NLRP3 proteins in hippocampus were increased (<0.01, <0.05) in the model group. After EA intervention, the average escape latency of rats was significantly shortened (<0.01), and the times of crossing the original platform were increased (<0.05), the level of ROS, the expression levels of LC3-Ⅱ/LC3-Ⅰ ratio, Beclin1 and NLRP3 proteins in hippocampus were decreased (<0.01, <0.05) in the EA group compared with those of the model group. Outcomes of TEM showed that CA1 neurons in the hippocampus were damaged, chromatin aggregation, mitochondria pyknosis, cristae structure disorder, rough endoplasmic reticulum expanded and degranulated, the number of free ribosomes decreased, and autophagy could be seen in the model group, which were milder in the EA group.
EA at GV20, GV14 and BL23 can improve the learning and memory abilities of VD rats, alleviate the ultrastructural damage of neurons in hippocampal CA1 area, and repair the damaged neurons. The mechanism may be related to the reduction of ROS level, LC3-Ⅱ/LC3-Ⅰ ratio, NLRP3 and Beclin1 protein expression, the decrease of neuronal autophagy, inhibition of activation of NLRP3 inflammasome and alleviation of central inflammatory response.
观察电针（EA）对血管性痴呆（VD）大鼠学习记忆能力、海马CA1区神经元超微结构变化、活性氧（ROS）水平、Nod样受体蛋白3（NLRP3）及海马自噬相关蛋白表达的影响，以揭示其治疗VD的部分机制。
雄性SD大鼠随机分为假手术组、模型组和电针组（每组10只）。采用永久性结扎双侧颈总动脉法建立VD模型。电针组大鼠于“百会”（GV20）、“大椎”（GV14）及双侧“肾俞”（BL23）进行电针治疗30分钟，每日1次，共4周。采用Morris水迷宫评价建模前、建模4周后及干预后大鼠的学习记忆能力。采用透射电子显微镜（TEM）观察海马CA1区神经元超微结构变化。用DCFH-DA荧光探针检测海马组织中ROS水平。采用蛋白质免疫印迹法检测NLRP3、自噬相关蛋白Beclin1和微管相关蛋白1轻链3（LC3）的表达。
与假手术组比较，模型组大鼠平均逃避潜伏期延长（<0.01），穿越原平台次数减少（<0.05），海马组织中ROS水平、LC3-Ⅱ/LC3-Ⅰ比值、Beclin1及NLRP3蛋白表达水平升高（<0.01，<0.05）。电针干预后，与模型组比较，电针组大鼠平均逃避潜伏期显著缩短（<0.01），穿越原平台次数增加（<0.05），海马组织中ROS水平、LC3-Ⅱ/LC3-Ⅰ比值、Beclin1及NLRP3蛋白表达水平降低（<0.01，<0.05）。TEM结果显示，模型组海马CA1区神经元受损，染色质聚集，线粒体固缩，嵴结构紊乱，粗面内质网扩张、脱颗粒，游离核糖体数量减少，可见自噬现象，电针组损伤较轻。
针刺GV20、GV14及BL23可改善VD大鼠的学习记忆能力，减轻海马CA1区神经元超微结构损伤，修复受损神经元。其机制可能与降低ROS水平、LC3-Ⅱ/LC3-Ⅰ比值、NLRP3及Beclin1蛋白表达，减少神经元自噬，抑制NLRP3炎性小体激活，减轻中枢炎症反应有关。
