重组人粒细胞集落刺激因子对大鼠脑缺血再灌注损伤脑组织NF-κB和iNOS表达的影响

Effect of recombinant human granulocyte colony-stimulating factor on the expression of NF-κB and iNOS following cerebral ischemia/reperfusion injury in rats

目的探讨重组人粒细胞集落刺激因子(rhG-CSF)在大鼠脑缺血再灌注损伤中的神经保护机制。方法将健康成年雄性SD大鼠随机分为假手术组、模型组和rhG-CSF治疗组(治疗组),每组12只。用Longa线栓法制作大鼠大脑中动脉缺血模型,治疗组于脑缺血后2h实施再灌注并予rhG-CSF(50μg/kg)腹部皮下注射,假手术组和模型组给予等量生理盐水。采用Longa 5分制评分标准进行神经功能缺损评分,免疫组化法(PV-6001二步法)检测各组大鼠脑组织中核转录因子-κB p65(NF-κB p65)和诱导型一氧化氮合酶(iNOS)表达水平,2,3,5-三苯基氯化四氮唑(TTC)染色法测定脑梗死体积。结果模型组与治疗组大鼠均可见大脑中动脉供血区梗死灶,治疗组大鼠脑梗死体积〔(24.04±1.49)%〕较模型组〔(31.05±1.49)%〕减小(t=8.12,P<0.01),治疗组神经功能评分(1.25±0.45)低于模型组(2.58±0.67)(U=12.00,P<0.01);治疗组NF-κB p65、iNOS表达的灰度值〔分别为(136.18±5.26)、(128.05±3.19)〕均较模型组〔分别为(96.67±3.94)、(109.73±6.07)〕增高(分别t=-39.51、P<0.01,t=-18.31、P<0.01);假手术组大鼠脑组织未发现梗死灶,脑组织内NF-κB和iNOS表达的灰度值〔分别为(161.86±4.27)、(163.99±4.08)〕高于模型组(分别t=65.20、P<0.01,t=54.26、P<0.01)。结论 rhG-CSF对脑缺血再灌注损伤具有神经保护作用,其机制可能与降低NF-κB p65、iNOS表达,抑制炎性反应有关。

Objective To explore the neuroprotective mechanism of recombinant human granulocyte-stimulating factor in brain damage following cerebral ischemia/reperfusion in the rats. Methods Thirty-six male Sprague-Dawley rats were randomly divided into the sham-operated group,the model group and the rhG-CSF-treatment group（treatment group）,and 12 rats were included in each group.The middle cerebral artery occlusion was established by the Longa suture method.In the treatment group,a single dose of 50 μg/kg rhG-CSF was injected subcutaneously 2 hours after cerebral ischemia.The sham-operated group and model group received the same volume of saline.The neurological function was scored with Longa 5-point scale.The expression levels of NF-κB p65 and iNOS were detected by immunohisto-chemistry（PV-6001 two-step method）.The infarction volume was revealed by TTC stain. Results The infarction territory of the middle cerebral artery could be seen in the model group and the treatment group.The infarction volume and neurological outcome scores of the treatment group[respectively（24.04±1.49）%,（1.25±0.45） ]were lower than the model group [respectively（31.05±1.49）%,（2.58±0.67）]）（t= 8.12,P0.01;U=12.00,P0.01,respectively）.Compared with the model group [（96.67±3.94）,（109.73±6.07）],the mean gray values of the expressions of NF-κB p65 and iNOS were significantly increased in the treatment group [respectively（136.18±5.26）,（128.05±3.19）]（t=-39.51,P0.01;t=-18.31,P0.01,respectively）.Infarction was not found in the sham-operated group,and compared with the model group,the mean gray values of the expressions of NF-κB p65 and iNOS [respectively（161.86±4.27）,（163.99±4.08）] were higher（t=65.20,P0.01;t=54.26,P0.01,respectively） in the sham group. Conclusions rhG-CSF could protect brain from ischemia/reperfusion injury.This may be achieved by decreasing the expressions of NF-κB p65 and iNOS and inhibiting the inflammatory response.