胰岛素样生长因子Ⅰ与促红细胞生成素经鼻给药对癫大鼠的协同抗凋亡作用

Anti-Apoptotic Actions of Intranasal Insulin-Like Growth Factor Ⅰ and Erythropoietin in Rats with Epilepsy

目的研究胰岛素样生长因子Ⅰ(IGF-Ⅰ)与促红细胞生成素(EPO)经鼻给药后对癫大鼠的抗凋亡作用,初步评价二者小剂量经鼻给药的疗效,并探讨其可能的作用机制。方法取SD雄性大鼠60只制作癫模型,随机分为:9 g.L-1盐水(NS)组、IGF-Ⅰ组、IGF-Ⅰ+EPO组、EPO组,分别鼻饲9 g.L-1盐水、IGF-Ⅰ、IGF-Ⅰ加EPO及EPO,应用流式细胞仪检测大鼠海马神经元细胞凋亡率;Western blot法检测其海马神经元细胞中凋亡蛋白XIAP、Smac/DIABLO及Caspase-9的表达。结果IGF-Ⅰ与EPO单用治疗组与NS组比较,可更大的降低凋亡率,更多的增加XIAP蛋白的表达,更大程度的减少Smac/DIABLO及Caspase-9的表达,而二者合用组则优于二者单用组(Pa<0.01)。结论IGF-Ⅰ和EPO经鼻给药可绕过癫大鼠血脑屏障,并通过嗅神经和三叉神经介导的细胞外途径快速进入中枢神经系统,二者均可通过上调XIAP的表达和减少Smac/DIABLO的表达来抑制Caspase-9的激活,从而发挥其抗凋亡作用,其联合应用比单用有更好的协同抗凋亡作用。

Objective To investigate the anti - apoptotic actions of intranasal insulin - like growth factorⅠ （ IGF -Ⅰ ） and erythropoietin （EPO） in rats with epilepsy, and to make a preliminary assessment about the curative effect of intranasal IGF -Ⅰ and EPO,and to investigate the possible mechanism of this action. Methods The models of epilepsy were established. Then the rats were divided into 4 groups according to the factorial design：sodium chloride group,IGF -Ⅰ group,IGF -Ⅰ ＋ EPO group and EPO group. The percentage of cell apoptosis was examined by the flow cytometry. The expression levels of Caspase - 9, XIAP, Smac/DIABLO protein were examined by Western blot. Results Compared with sodium chloride group, EPO and IGF - I group could significantly reduce the cell apoptosis and improve the expression of XIAP protein, and reduce the expression of Caspase - 9 and Smac/DIABLO, IGF -Ⅰ ＋ EPO group got the better results than the EPO group and IGF -Ⅰ group. Conclusions Intranasal administration IGF -Ⅰ ＋ EPO can bypass the blood - brain barrier via olfactory - and trigeminal - associated extracellular pathways rapidly into the central nervous system. Then they can induce an anti - apoptotic action by up - regulation the expression level of XIAP protein and reduce the expression of Smac/DIABLO protein at the same time to restrain the activation of Caspase - 9 protein. The cooperativity of IGF - 1 ＋ EPO has better actions on the anti - apoptosis than the IGF - 1 and EPO alone.