人重组粒细胞集落刺激因子干预对脑缺血/再灌注大鼠MCP-1、IL-8表达的影响

Effect of rh G-CSF intervention on the expression of IL-8 and MCP-1 in cerebral ischemia reperfusion rats

目的探讨人重组粒细胞集落刺激因子(rh G-CSF)对大鼠局灶性脑缺血/再灌注(I/R)损伤中单核细胞趋化蛋白-1(MCP-1)、白细胞介素-8(IL-8)表达的影响。方法健康成年雄性SD大鼠54只,随机分为假手术组(Sham组,n=6)、脑缺血再灌注组(I/R组,n=24)和rh G-CSF处理组(CSF组,n=24),I/R组和CSF组按缺血再灌后不同时间点(6 h、12 h、24 h、48 h)分为4个亚组,每组6只。采用改良线栓法制作大脑中动脉脑缺血再灌注模型,CSF组在缺血再灌注2 h即刻给予皮下注射rh G-CSF(50μg/kg),其他两组给予等体积生理盐水注射。采用Long 5分制进行神经功能缺损评分;HE染色观察脑组织形态变化;免疫组织化学方法检测脑组织中MCP-1的表达;ELISA法检测脑组织IL-8含量。结果 (1)神经功能缺损评分:Sham组大鼠评分均为0分;I/R组与CSF组大鼠均出现不同程度神经功能缺损,评分差异有统计学意义(P<0.05);(2)HE染色结果显示,Sham组的脑组织结构形态正常,I/R组及CSF组:脑组织均呈现缺血缺氧性改变,结构疏松不规则,部分神经细胞胞核固缩,胞质消失,但I/R组病变更显著;(3)与Sham组相比较,I/R组和CSF组MCP-1的表达及IL-8的含量均增高(均P<0.05);与I/R组相比较,CSF组MCP-1的表达及IL-8的含量在6 h、12 h、24 h各时间点均有不同程度的降低(均P<0.05),48 h时I/R组与CSF组相比较无明显差异(P>0.05)。结论在脑缺血再灌注早期,rh G-CSF干预能够减轻缺血/再灌注大鼠神经功能缺损症状,改善脑组织病理结构,这种保护作用可能是通过下调MCP-1的表达及IL-8的含量,以减轻局部炎症反应。

Objective To investigate the effect of human recombinant granulocyte colony stimulating factor（rh G-CSF） on the expression of IL-8 and MCP-1 in focal cerebral ischemia-reperfusion（I/R） injury in rats. Methods 54 healthy adult male SD rats were randomly divided into 3 groups： sham group： 6 rats were actualized sham operation; I/R group： 24 rats were divided into 4 sub groups according to the different time（6 h, 12 h, 24 h, 48 h） after ischemia and reperfusion. And the cerebral ischemia reperfusion model was produced by modified suture method. CSF group： rh G-CSF（50 μg/kg） were given subcutaneous injection to 24 mice at 2 hours after they were same treated as I/R group. At the same time, group 1 and group 2 were given equal volume of saline injection. The neurological deficit score was evaluated by Long5, the morphological changes of brain tissue were examined by HE staining, the expression of MCP-1 was detected by immunohistochemistry, and the concentration of IL-8 in brain tissue was measured by ELISA. Results Long5 score： the score in sham group was 0; neurologic dysfunction of different degrees was found in I/R group and CSF group and the score difference was statistically significant（P〈0.05）; HE staining： we observed normal organization structure in sham group, and we also found ischemia anoxic changes, loose irregular structure of brain tissue and numerous nerve cells＇ nuclei became pyknotic and some cytoplasm disappeared in I/R group and CSF group, and these manifestations in I/R group were worse; compared with the Sham group, the expression of MCP and the concentration of IL-8 in I/R group and CSF group were increased significantly（P〈0.05）; the expression of MCP and the concentration of IL-8 in CSF group at 6 h, 12 h, 24 h MCP-1 were lower than I/R group, with significant difference（P〈0.05）, however, there had no statistical significant difference（P〈0.05） between I/R group and CSF group at 48 h. Conclusion rh G-CSF-intervention can improve the symptoms of ischemiareperfusion neurologic function defect in rats, improve tissue pathological structure, and may reduce local inflammation reaction and cerebral ischemia-reperfusion injury by decreasing the expression of MCP and the concentration of IL-8 in early cerebral ischemia reperfusion.