粒细胞集落刺激因子对脑小血管病大鼠神经保护机制的研究

A Study on the Neuroprotective Mechanisms of Granulocyte Colony Stimulating Factor in Rats with Cerebral Small Vessel Disease

目的观察粒细胞集落刺激因子(G-CSF)对脑小血管病的神经保护作用,并探讨其可能机制。方法采用完全随机化方法将自发性高血压大鼠分为治疗组和模型组,另选择Wistar大鼠作为对照组。治疗组皮下注射G-CSF 50μg·kg^(-1)·d^(-1),连续7 d;模型组和对照组分别皮下注射等量生理盐水。采用免疫组化法检测基底节区血管内皮生长因子(VEGF)、血管性血友病因子(vWF)表达水平;TUNEL法检测神经元凋亡情况;透射电镜观察微血管超微结构变化。结果治疗组和模型组VEGF表达水平均高于对照组,且治疗组高于模型组,3组间比较差异有统计学意义(P<0.05)。治疗组vWF表达水平低于对照组,但较模型组有所增加,3组间比较差异有统计学意义(P<0.05)。治疗组细胞凋亡率高于对照组,但较模型组有所降低,3组间比较差异有统计学意义(P<0.05)。透射电镜下可见模型组微血管结构破坏及内皮细胞损伤明显,而治疗组和对照组微血管结构变化及内皮细胞损伤不明显。结论 G-CSF可能通过增加VEGF表达水平,促进脑小血管内皮细胞修复,减少神经元凋亡,从而减轻自发性高血压大鼠脑小血管病损伤。

Aim To observe the neuroprotective effect of granulocyte colony stimulating factor（G-CSF） on cerebral small vessel disease（CSVD）, and explore its possible mechanism. Methods Spontaneously hypertensive rats（SHR） were randomly divided into a treatment group and a model group. Wistar rats were used as the control group. The rats of the treatment group were given G-CSF by subcutaneous injection of 50 μg·kg-（-1）·d-（-1） for 7 days. The rats of model and the control group were given the same dose of normal saline. Immunohistochemical staining was used to detect the expression of vascular endothelial growth factor（VEGF）, von Willebrand factor（vWF） in basal ganglia. TUNEL was performed to assess the cell apoptosis. The changes of microvascular ultrastructure were observed by transmission electron microscope. Results The expression of VEGF in the model group, the difference between groups were statisticallysignificant（P〈0.05）. The expression of v WF in the treatment group and the model group were obviously increased as compared with the control group, and the treatment group was higher than that in the treatment and were significantly lower than that in the control group, but significantly increased than that in the model group, the difference among the groups were statistically significant（P〈0.05）. The apoptosis rate of treatment group was significantly higher than that of the control group, however, when compared with the model group, the cell apoptosis rate decreased, and the difference between the groups were statistically significant（P〈0.05）. Transmission electron microscopy showed that the damage of microvascular structure and endothelial cells in the model group were obvious, while the changes of the microvascular structure and the damage of endothelial cells in the treatment group and the control group were mild. Conclusion G-CSF could increase the expression of VEGF and promote the repairment of vascular endothelial cell, and reduce neuronal apoptosis, which could reduce the cerebral small vessel injury in spontaneously hypertensive rats.