基于MCL-1mRNA表达探讨经颅磁刺激对大脑中动脉阻塞模型大鼠脑组织损伤的作用机制

Mechanism of Transcranial Magnetic Stimulation on Brain Tissue Injury in Rats with Middle Cerebral Artery Occlusion Based on MCL-1 mRNA Expression

目的:基于骨髓细胞白血病序列1(MCL-1)表达探讨经颅磁刺激(TMS)对大脑中动脉阻塞(MCAO)模型大鼠脑组织损伤的作用机制。方法:选择健康雄性无特定病原体(SPF)级SD大鼠30只(3月龄),采用随机数字表法将30只大鼠分为假手术组、模型组和TMS组,各10只,建模成功后24 h内进行TMS治疗。采用Longa评分评估3组神经功能缺损程度;采用2,3,5-三苯基氯化四氮唑(TTC)染色测定脑梗死面积;采用末端脱氧核苷酸转移酶介导的dUTP缺口末端标记(TUNEL)检测细胞凋亡;采用蛋白免疫印记法(Western Blot)检测MCL-1蛋白表达水平;采用逆转录实时荧光定量聚合酶链反应(RT-PCR)检测MCL-1mRNA表达水平。结果:假手术组大鼠神经功能缺损评分、脑梗死面积均低于TMS组、模型组,TMS组神经功能缺损评分、脑梗死面积均低于模型组(P<0.05)。假手术组细胞凋亡指数低于TMS组、模型组,TMS组细胞凋亡指数低于模型组(P<0.05)。假手术组MCL-1mRNA高于TMS组、模型组,TMS组MCL-1mRNA高于模型组(P<0.05)。假手术组MCL-1蛋白表达水平高于TMS组、模型组,TMS组MCL-1蛋白表达水平高于模型组(P<0.05)。结论:TMS通过升高MCL-1mRNA表达,减少细胞凋亡,抑制MCAO大鼠脑组织损伤。

Objective:To explore the mechanism of transcranial magnetic stimulation(TMS)on brain tissue injury in rats with middle cerebral artery occlusion(MCAO)based on myelocytic leukemia sequence 1(MCL-1).Methods:Thirty healthy free of specific pathogens(SPF)male SD rats(3 months old)were randomly divided into sham operation group,model group and TMS group,with 10 rats in each group.TMS treatment was performed within 24 h after successful modeling.Longa score was used to evaluate the degree of neurological impairment in 3 groups.The infarct area was measured by 2,3,5-triphenyltetrazolium chloride(TTC)staining.Apoptosis was detected by dUTP notch end labeling(TUNEL)mediated by terminal deoxynucleotide transferase.The protein expression of MCL-1 was detected by Western Blot.The mRNA expression of MCL-1 was detected by reverse transcription rea-l time fluorescent quantitative polymerase chain reaction(RT-PCR).Results:The nerve function deficit score and cerebral infarction area of rats in the sham operation group were less than those in the TMS group and model group,and the nerve function deficit score and cerebral infarction area of rats in the TMS group were less than those in the model group(P<0.05).The apoptosis index of the sham operation group was less than that of the TMS group and model group,and that of TMS group was less than that of model group(P<0.05).The expression of MCL-1mRNA in the sham operation group was more than that in the TMS group and model group,and the expression of MCL-1mRNA in the TMS group was more than that in the model group(P<0.05).The levels of MCL-1 protein in the sham operation group were higher than that in the TMS group and model group,and the level of MCL-1 protein in the TMS group was higher than that in the model group(P<0.05).Conclusion:TMS could reduce cell apoptosis and inhibit brain tissue injury in MCAO rats by increasing the expression of MCL-1mRNA.