面神经损伤与修复对大鼠面神经核内信号转导子和转录激活子3活性的影响

Effects of injury of facial nerve and its repair on the signal transducer and activator of transcription-3 in facial nerve nucleus in rats

目的:探讨面神经损伤与修复条件下,面神经核运动神经元信号转导子和转录激活子3的活性以及DNA结合活性的变化。方法:实验于2004-07/10在解放军第三○三医院神经科实验室完成,选择成年雄性SD大鼠40只,随机分为2组,每组20只。单纯面神经切断组:大鼠左侧面神经切断后不予吻合处理。面神经切断后吻合组:大鼠左侧面神经切断后给予端端吻合。两组大鼠右侧面神经(健侧)作为对照。检测成年大鼠面神经切断和即刻端端吻合后面神经核内信号转导子和转录激活子3以及DNA结合活性的变化,运用抗磷酸化转导子和转录激活子3抗体做免疫印迹以及电泳迁移率改变的实验。结果:参加试验2组40只大鼠,在实验过程中,2组各有2只动物死亡,最终进入结果分析为2组,每组18只。①两组面神经核内抗磷酸化转导子和转录激活子3含量:两组健侧面神经核内抗磷酸化转导子和转录激活子3含量较低,术后第7天,两组转导子和转录激活子3磷酸化水平均较健侧增加,其增加值分别为100.9%和97.0%,两者与健侧均具有显著差异(t=-35.223,-39.778,P<0.05)。两组抗磷酸化转导子和转录激活子3含量较接近(P>0.05)。②两组面神经核内转导子和转录激活子3DNA结合活性:两组健侧面神经核抽提物的DNA结合活性较低,术后7d,两组转导子和转录激活子3DNA结合活性显著增加,其增加值分别为118.3%和116.0%(t=-185.726,-172.800,P<0.05)。两组之间转导子和转录激活子3DNA结合活性接近(P>0.05)。结论:面神经损伤可以诱导损伤侧面神经核运动神经元的信号转导子和转录激活子3磷酸化以及DNA结合活性增加,经端端吻合修复损伤面神经,上述两指标亦增加,两者增加幅度基本一致。提示面神经损伤后面神经核运动神经元内由信号转导子和转录激活子3介导的细胞因子的信号转导作用增加。

AIM： To explore the changes in the activation of signal transducer and activator of transcription-3 （STAT3） and DNA binding activation in facial nerve nucleus after facial nerve injury and repair. METHODS： The experiment was done in Laboratory of Department of Neurology of the 303 Hospital of Chinese PLA from July to October 2004. Forty adult male SD rats were selected and divided randomly into 2 groups with 20 rats in each group. Pure facial nerve broken group： After breaking, left-sideness facial nerve of rats was not conducted anastomosis treatment. Anastomosis treatment group after breaking： Left-sideness facial nerve of rats was conducted end-to-end anastomosis. Right-sideness facial nerves（uninjured side） of rats in the two groups were conducted as control. The changes on activation of STAT3 and DNA binding activation in facial nerve nucleus were detected after the breaking of facial nerves and instant end-to-end anastomosis. The experiment of immunoblot and alteration of electrophoresis migration was conducted by antibody of STAT3. RESULTS： Two groups were involved in the analysis of results. Among the forty rats in the two groups, two rats in each group died in the process of experiment. ① The content of anti-phosphoric acid transduction factor and transcription activator 3 in nucleus of facial nerve in the two groups： The content of anti-phosphoric acid transduction factor and transcription activator 3 in uninjured side of facial nerves was very low. On the 7^th day after operation, the level of phosphoric acid in transduction and transcription activator 3 became higher than that of uninjured side, which was 100.9% and 97.0% respectively. They all had significant difference compared with uninjured side （t=-35.223, -39.778, P 〈 0.05）. The contents of anti-phosphoric acid transduction factor and transcription activator 3 were similar （P 〉 0.05）. ② DNA binding activity of transduction factor and transcription activator 3 in the two groups： DNA binding activity of extractive of uninjured side of facial nerves was very low. On the 7^th day after operation, DNA binding activity of transduction factor and transcription activator 3 in the two groups significantly increased, and it was 118.3% and 116.0%,respectively （t=-185.726, -172.800, P 〈 0.05）. DNA binding activity of transduction factor and transcription activator 3 between the two groups was similar （P 〉 0.05）. CONCLUSION： Phosphoric acid of STAT3 and DNA binding activity adds in the injury of side facial nerve nucleus motoneurons, which is induced by injury of facial nerve. After the repair of injury of facial nerve by end-to-end anastomosis, the two above-mentioned indexes increase, too, and the increase range is coincident basically. Action of signal transduction of mediated cytokine indicated by STAT3 raises in motoneurons of facial nerve nucleus after facial nerve injury.