FK506对大鼠弥漫性轴索损伤后神经元凋亡及轴突再生相关蛋白表达的影响
The influence of FK506 on the expressions of proteins related to neuronal apoptosis and regeneration following diffuse axonal injury in rats

摘要：目的 研究FK506对大鼠弥漫性轴索损伤后神经元凋亡及轴突再生相关蛋白神经丝蛋白200(NF200)、神经生长相关蛋白43(GAP-43)、凋亡相关蛋白激酶1(DAPK1)表达的影响。方法 通过头颅瞬间旋转损伤装置建立大鼠弥漫性轴索损伤模型，90只SD成年雄性大鼠随机分为假手术组、DAI模型组、FK506干预组(各组又分为6h、1d、7d亚组，各组n=10)；各组于预定时间点采用mNSS法评估神经功能，免疫组化染色法检测DAPK1、NF200的表达变化，Western blot法检测GAP-43的表达变化、TUNEL检测神经元凋亡，实验数据以均数±标准差记录，使用统计学SPSS 18.0软件进行单因素方差分析，以P<0.05为差异有统计学意义。结果 FK506干预组较DAI组损伤后的NF200标记轴索病理改变显示，形成轴索肿胀、轴索球数目明显降低；FK506干预组较DAI组各时间点DAPK1蛋白表达明显降低，神经元凋亡数目明显减少，GAP-43、NF200蛋白表达明显升高。结论 FK506能够在DAI后减少神经元细胞凋亡与轴索病理改变，减轻神经组织损伤；FK506能够加速神经元再生，促进脑组织损伤的修复。
ABSTRACT: Objective To explore the influence of FK506 on the expressions of DAPK1, NF200 and GAP-43, proteins related to neuronal injury and regeneration following diffuse axonal injury (DAI) in rats. Methods The model of DAI by instant head rotation was produced in 90 adult male SD rats. The rats were randomly divided into three groups: sham group without injury, DAI group, and FK506 intervention group. Each group was divided into 6h, 1d and 7d sub-groups with 10 rats in each. The nerve function of each group was detected by the modified neurological severity scores (mNSS) at scheduled time points. The expressions of DAPK1 and NF200 were detected using immunohistochemistry staining method; the expression of GAP-43 was detected using Western blot; and the number of the apoptotic neurons after DAI was counted by TUNEL staining. Data were expressed as the mean values ± standard deviation. All data were analyzed with the Statistical Package for the Social Sciences version 18.0. A value of P<0.05 was considered statistically significant. Results In the FK506 intervention group, the expression of DAPK1 protein was significantly reduced, and the number of apoptotic neurons decreased significantly compared with those in the DAI group at each time point. NF200 labeled axonal pathology showed that axonal swelling and axonal ball number were decreased in the FK506 intervention group compared with the DAI group. In the FK506 intervention group, the expression of DAPK1 protein and the number of apoptotic neurons were reduced significantly at each time point; the expressions of GAP-43 and NF200 protein increased significantly compared with those in the DAI group. Conclusion FK506 can reduce the apoptosis of neurons and axon pathological changes after DAI, thus lessening nerve tissue injury. FK506 can also accelerate the regeneration of neurons and promote the repair of brain tissue injury