经鼻导入rhG—CSF对脑梗死大鼠皮层FasL和HO-1表达的影响

Effect of intranasal administration of recombinant human granulocyte colony stimulating factor on cortical expressions of Fas ligand and hemeoxygenase-1 in rats with cerebral infarction

目的探讨经鼻靶向中枢导入重组人粒细胞集落刺激因子（rhG-CSF）对脑梗死大鼠皮层Fas配体（FasL）和血红素氧合酶-1（HO-1）表达的影响。方法将60只大鼠按随机数字表法分为正常组、假手术组、脑梗死组、脑梗死＋皮下注射rhG—CSF组、脑梗死＋经鼻导人生理盐水组、脑梗死＋经鼻导入rhG—CSF组。线栓法制作大鼠可逆性大脑中动脉阻塞（MCAO）模型，2h后再灌注。于MCAO模型制作成功后1d、3d制备脑组织冠状冰冻切片，用免疫荧光染色检测FasL和HO-1在缺血半暗带皮层的表达，激光共聚焦显微镜采集图像并计数阳性细胞数。结果正常组和假手术组大鼠脑组织中见极少量FasL和HO—1阳性细胞．两组比较差异无统计学意义（P〉0．05）。脑梗死组大鼠FasL和HO-1阳性细胞数明显增加（1d时较3d时高），表达区域主要为缺血半暗带皮层，与脑梗死＋经鼻导人生理盐水组比较差异无统计学意义（P〉0．05）。经鼻给予rhG—CSF治疗后脑梗死大鼠脑组织内FasL阳性细胞表达下降．HO—1阳性细胞表达进一步上调，与脑梗死＋皮下注射rhG—CSF组大鼠比较差异有统计学意义（P〈0．05）。结论经鼻靶向中枢导入rhG—CSF可以通过降低FasL、上调HO-1表达抑制脑梗死大鼠缺血半暗带皮层神经元凋亡，参与脑保护机制。

Objective To investigate the effect of intranasal administration of recombinant human granulocyte colony stimulating factor （rhG-CSF） on Fas ligand （FasL） and hemeoxygenase-1 （HO-1） expressions in the cortical brain tissue of rats with ischemic cerebral infarction. Methods Sixty adult male SD rats were randomly assigned into 6 groups, namely the normal control group （n=6）, sham-operated group （n=6）, middle cerebral artery occlusion （MCAO） group （model group）, and another 3 MCAO groups with intranasal administration of normal saline （NS）, subcutaneous rhG-CSF injection, and intranasal rhG-CSF administration, respectively. In the 4 MCAO groups （n=12）, the rats were subjected to temporary middle cerebral artery occlusion （MCAO） for 2 h, and on the next and third days following MCAO, 6 rats from each group were sacrificed and the coronal frozen sections of the brain tissue were prepared to detect the expressions of FasL and HO-1 in the ischemic penumbra using immunohistochemical staining. Laser scanning confocal microscopy was performed to observe the amount of positive cells in the ischemic penumbra. Results In both of the normal control and sham-operated groups, only a small number of FasL- and HO-1-positive cells were found in the brain of the rats （P〉0.05）. In MCAO model group, the expressions of FasL and HO-1 increased obviously, which were higher on day 1 than on day 3 and located mainly in the ischemic penumbra, and saline administration did not cause obvious changes in their expressions （P〉0.05）. rhG-CSF treatment, administered either intranasally or subcutaneously, resulted in significantly lowered FasL expression and increased HO-1 expression, but the changes were more obvious in intranasal rhG-CSF group （P〈0.05）. Conclusion Intranasal rhG-CSF administration offers brain protection by inhibiting FasL expression and up-regulating HO-1 expression in rats with cerebral ischemia.