电针预处理对脂多糖诱导的认知障碍小鼠线粒体动力学的影响

Effect of electro-acupuncture pretreatment on mitochondrial dynamics in mice with lipopolysaccharide-induced cognitive impairment

目的观察电针预处理对脂多糖(LPS)诱导的认知障碍小鼠线粒体动力学的影响。方法将45只10~11周龄SPF级雄性C57BL/6小鼠(体重25~27 g)按随机数字表法分为对照组、模型组和电针组,每组15只。模型组和电针组侧脑室注射LPS建立神经炎症诱导的认知障碍小鼠模型,对照组注射人工脑脊液。电针组于造模前对小鼠神庭、百会、足三里、内关行电针治疗,30 min/次,5次/周,连续2周。造模后6 h,每组随机选5只小鼠处死取材,采用酶联免疫吸附试验检测其海马组织肿瘤坏死因子-α(TNF-α)和白细胞介素1β(IL-1β)水平。造模后24 h,采用旷场实验观察各组剩余小鼠的自发活动和焦虑行为,Morris水迷宫空间探索测试评估认知功能,化学发光法检测各组海马组织腺苷三磷酸(ATP)水平,流式细胞术检测线粒体膜电位(MMP),蛋白质印迹法检测发动蛋白相关蛋白1(DRP1)和线粒体融合蛋白2(MFN2)的表达。结果模型组移动总路程、中央区停留时间和穿越中央区次数与对照组比较,差异无统计学意义(P>0.05)。电针组移动总路程、中央区停留时间和穿越中央区次数与模型组比较,差异无统计学意义(P>0.05)。模型组穿越原平台次数和目标象限停留时间百分比及海马组织MMP、ATP、MFN2水平均低于对照组,海马组织TNF-α、IL-1β、DRP1水平高于对照组,差异有统计学意义(P<0.05)。电针组穿越原平台次数和目标象限停留时间百分比及海马组织MMP、ATP、MFN2水平均高于模型组,海马组织TNF-α、IL-1β、DRP1水平低于模型组,差异有统计学意义(P<0.05)。结论电针预处理改善LPS诱导的小鼠认知功能障碍,降低神经炎症,其机制可能与抑制线粒体分裂,促进线粒体融合有关。

Objective To observe the effect of electro-acupuncture pretreatment on mitochondrial dynamics in mice with lipopolysaccharide(LPS)-induced cognitive impairment.Methods Forty-five SPF male C57BL/6 mice aged 10 to 11 weeks(body weight 25 to 27 g)were divided into control group,model group,and electro-acupuncture group according to random number table method,with 15 mice in each group.The model group and the electro-acupuncture group were injected with LPS in the lateral ventricle to establish the neuroinflammation-induced cognitive impairment mouse model,and the control group was injected with artificial cerebrospinal fluid.Before modeling,shéntíng,bǎihuì,zúsānlǐ,and nèiguān were treated with electro-acupuncture,30 min/time,five times/week for two consecutive weeks.Six hours after modeling,five mice in each group were randomly selected and sacrificed,and the levels of tumor necrosis factor-α(TNF-α)and interleukin-1β(IL-1β)in hippocampus were detected by enzyme-linked immunosorbent assay.Twenty-four hours after modeling The open field test was used to observe the spontaneous activity and anxiety behavior of the remaining mice in each group,the Morris water maze space exploration test was used to evaluate the cognitive function,the level of adenosine triphosphate(ATP)in hippocampus was detected by chemiluminescence method,and mitochondrial membrane potential(MMP)was detected by flow cytometry.The expressions of dynamin-related protein 1(DRP1)and mitofusion 2(MFN2)were detected by Western blotting.Results There were no significant differences between the model group and the control group in the total travel distance,the time of staying in the central area,and the number of crossing the central area(P>0.05).There were no significant differences between the electro-acupuncture group and the model group in the total distance traveled,the time spent in the total travel distance,the time of staying in the central area,and the number of crossing the central area(P>0.05).The times of crossing the original platform,the percentage of residence time in the target quadrant,and the levels of MMP,ATP,and MFN2 in hippocampus in model group were lower than those in control group,while the levels of TNF-α,IL-1β,and DRP1 in hippocampus were higher than those in control group,the differences were statistically significant(P<0.05).The times of crossing the original platform,the percentage of residence time in the target quadrant,and the levels of MMP,ATP,and MFN2 in hippocampus in electro-acupuncture group were higher than those in model group,while the levels of TNF-α,IL-1β,and DRP1 in hippocampus were lower than those in model group,the differences were statistically significant(P<0.05).Conclusion Electro-acupuncture pretreatment can improve the cognitive dysfunction and reduce neuroinflammation induced by LPS-induced mice,and its mechanism may be related to inhibiting mitochondrial fission and promoting mitochondrial fusion.