脑出血后氧化应激对神经细胞凋亡及c-myc蛋白表达的影响

目的 观察脑出血后氧化应激与神经细胞凋亡的相关性及对凋亡相关蛋白c-myc表达的影响。 方法 选择SD雄性大鼠84只,随机分为假手术组、模型组、MPEG-SOD组,每组28只,自体血注入法建立脑出血模型,MPEG-SOD组建模前腹腔注射MPEG-SOD;术后12 h、1 d、3 d、7 d不同时间点行神经功能缺陷评分(NDS),取脑组织测定脑组织含水量,分光光度法测定丙二醛(MDA)、超氧化物歧化酶(SOD),免疫组化法测定核因子κB(NF-κB) p65阳性细胞表达,TUNEL测定神经细胞凋亡,Western blot测定c-myc蛋白表达水平。 结果 与假手术组比较,模型组各时点NDS评分、SOD活性明显降低,脑组织含水量、MDA含量、c-myc蛋白、NF-κB p65、TUNEL阳性细胞表达明显升高(P<0.05),术后3 d达峰值,与模型组同时点比较,MPEG-SOD组NDS评分、SOD活性明显升高,脑组织含水量、MDA含量、c-myc蛋白、NF-κB p65、TUNEL阳性细胞表达明显降低(P<0.05),c-myc蛋白表达与TUNEL阳性细胞数呈正相关(模型组r=0.83,MPEG-SOD组r=0.91,P<0.05)。 结论 脑出血后氧化应激诱导神经细胞凋亡可能与启动凋亡相关基因c-myc有关。 

Effects of oxidative stress on neuronal apoptosis and protein expression of c-myc after intracerebral hemor rhage

Objective To investigate the relationship between oxidative stress and neuronal apoptosis after intracerebral hemorrhage (ICH),and the influence of oxidative stress on c-myc expression. Methods Eighty-four male SD rats of 7-week-old were selected and randomly divided into sham operation group,model group,MPEG-SOD group,with 28 rats in each group.Intracerebral hemorrhage model was induced by autologous blood injection.Rats in MPEG-SOD group were injected with MPEG-SOD before modeling.The neurological deficit score (NDS) was measured at 12 h,1 d,3 d and 7 d after the operation.The water content of brain tissue was measured,and the content of malondialdehyde (MDA) and superoxide dismutase (SOD) in brain was measured by spectrophotometric method.The expression of nuclear factor-kappa B (NF-κB) p65 positive cells was detected by immunohistochemistry.The apoptosis of neurons was measured by TUNEL and the expression of c-myc protein was detected by Western blot. Results Compared with the sham-operated group,the NDS score and SOD activity at each time points were obviously decreased,while the water content in the brain tissue,MDA content,c-myc protein expression,NF-κB p65 and TUNEL-positive cells in the model group were significantly increased (P<0.05),which reached the peak 3d after the operation.Compared with the model group,the NDS score,SOD activity,water content in the brain tissue,MDA content,c-myc protein expression and TUNEL,NF-κB p65 positive cells in the MPEG-SOD group were significantly decreased (P<0.05).The expression of c-myc protein and TUNEL-positive cells in the brain tissue was correlated (R=0.83 in model group,as well as r=0.91 in MPEG-SOD group,P<0.05). Conclusion The oxidative stress-induced apoptosis of neurons may be related to the initiation of apoptosis-related gene c-myc after intracerebral hemorrhage.