两种电针对脊髓损伤14天后大鼠运动功能、神经元及MEK2、p-ERK1表达的影响

Influences on the locomotor function,neuron and the expression of MEK2 and p-ERK1 of the 14^(th) day post-spinal cord injury rats by using two different electro-acupuncture therapies

目的基于Raf/Ras/ERK信号通路,探讨两种电针对大鼠脊髓损伤后14天丝裂原激活/细胞外信号调节激酶2(mitogen-activated/extracellular signal-regulated kinase 2,MEK2)、磷酸化细胞外信号调节蛋白激酶1(phosphorylation-extracellular signal-regulated kinase 1,p-ERK1)表达的影响以及对大鼠后肢运功功能和神经元的影响。方法雄性清洁级SD大鼠(60只),随机分为五组,空白组(12只)、假手术组(12只)、模型组(12只)、脉冲电针组(12只)、音乐电针组(12只)。采用改良式的Allen’s打击法复制模型。两组电针组选取"大椎""命门"进行不同电针针刺干预,每天1次,每次20分钟,空白组、假手术组及模型组在治疗组治疗时进行抓取束缚,保证处理条件的相同。脊髓损伤(spinal cord injury,SCI)后14天,采用神经功能评定法——BBB评分对大鼠脊髓损伤进行评估,综合评定大鼠SCI后的运动功能。采用HE染色、尼氏染色方法观察脊髓损伤大鼠损伤脊髓前角组织病理改变。运用免疫组化技术和Western blot技术观察损伤脊髓前角MEK2、p-ERK1含量的变化。结果 BBB评分结果显示,经脉冲电针与音乐电针治疗后,脊髓损伤大鼠后肢活动功能较模型组均有改善(P<0.01),且音乐电针评分高于脉冲电针,但两组比较无统计学差异;HE染色与尼氏染色结果说明脉冲电针与音乐电针组均可修复脊髓前角神经元细胞,增加神经元细胞中尼氏体含量,且音乐电针优于脉冲电针;免疫组化及Western Blot结果说明脉冲电针与音乐电针均可提高脊髓前角神经元中MEK2、p-ERK1的含量,但两者无统计学差异。结论脉冲电针与音乐电针均能诱导SCI大鼠脊髓内MEK2、p-ERK1的表达,促进脊髓损伤后神经修复再生功能,音乐电针作用较脉冲电针略有优势。

Objective To investigate the influences on the expression of MEK2 and p-ERK1 in the 14-（th） day post spinal cord injury（ SCI） by using two different electro-acupuncture（ EA） therapies,andfurther explore the possible roles of MEK2 and p-ERK1 in the development of experimental SCI and the effect of different EA for them. Methods Adult male Sprague-Dawley（ SD） rats were randomly divided into normal control group（ n = 12）,sham operation group（ no operation,without SCI nor treatment,n =12）,SCI model group（ SCI-induction without treatment,n = 12）,pulsed EA group（ SCI-induction with pulse-EA treatment,n = 12）,and music EA group（ SCI-induction with music-EA treatment,n = 12）. SCI model was established by using the modified Allen＇s method. Basso-Beattic-Bresnahan（ BBB） scale was performed to assess the locomotor function of rats. HE staining and Nissl＇s staining were used to observe the pathological changes of SCI rats and the situation of remnant neuron. The expression of MEK2 and pERK1 was detected by using Western blot and Immunohistochemical method. Results The BBB score of SCI model group are significantly lower than normal control group and sham operation group,while pulsedEA group and music-EA group could reverse it in the 14-（th） day post-SCI（ P〈0. 01）,but there was no statistical differences between the two treatment groups（ P〈0. 05）. The results of HE staining and Nissl＇s staining showed that the two kinds of treatment could improve this pathological changes. The expression of MEK2,p-ERK1 in SCI model group increased in the 14-（th） day post-SCI,while there was no statistical differences（ P〈0. 05）,the two kinds of treatment could up-regulate the level of expression of MEK2 and p-ERK1 more significantly,but also had no statistical differences（ P〈0. 05）,and there was no statistical differences between the two treatment groups（ P〈0. 05） at the same time. Conclusion The levels of MEK2 and p-ERK1 in SCI rats were higher than normal. The pulse- and music-EA treatments may effectively improve the levels of MEK2 and p-ERK1 in spinal cord,thus promoting the recovery of hindlimb function of SCI rats. The effectiveness of music-EA offered a better result in the recovery than that of pulseEA treatment,but there was no statistical differences between the two treatment groups in locomotor function and the expression of MEK2 and p-ERK1 in the 14-（th） day post-SCI.