【摘要】 目的确定细胞周期依赖性蛋白激酶-5(cyclin dependent kinases-5,cdk5)在C型尼曼-皮克病(Niemann-Pickdisease type C,NPC)神经元变性过程中的作用,为NPC的临床治疗提供可能的药物作用靶点。方法将针对cdk5基因的si RNA序列克隆入rAAV-2载体,对4周龄npc-/-小鼠进行小脑rAAV-cdk5-si RNA-GFP注射(n=8),以空载体病毒(rAAV-GFP)注射组及非手术的同龄npc小鼠为对照(n=8)。在干预后4周连续观察小鼠脑内cdk5水平及小鼠神经生化和病理的改变。结果注射后1周可见针道附近、小脑深部核团及浦肯野细胞出现绿色荧光蛋白表达。与空载体病毒组相比,注射4周后小鼠脑内cdk5的表达水平降低34.17%(P<0.05,n=6);轴突球状体数量减少30.76%(P<0.05,n=6),存活浦肯野细胞数增加300%(P<0.05,n=8);细胞骨架蛋白磷酸化程度降低16.32%(P<0.05,n=6)。结论rAAV2-cdk5-si RNA小脑注射,能显著减轻npc小鼠神经生化和病理改变。cdk5的激活在NPC神经元变性过程中起到了关键性的作用,有可能成为NPC治疗的新靶标。更多还原

【Abstract】 Objective To determine the precise role of cyclin dependent kinases-5(cdk5)in Niemann-Pick disease type C(NPC)neurodegeneration,and to offer a new therapeutic target for NPC.Methods Small interfering RNA(siRNA)specific for cdk5 gene was cloned into recombinant adeno-associated virus vector to generate rAAV-cdk5-siRNA-GFP.The rAAV-cdk5-siRNA-GFP and rAAV-GFP were injected into bilateral cerebella of 4-weeks-old npc mice respectively,and non-surgery age-matched npc mice were employed as controls(n=8 in each group).The cdk5 levels and neuropathological changes in these mice were observed.Results The expression of GFP could be detected in the path of needle,cerebellar deep nuclei and Purkinje neurons at the first week after injection.Four weeks after injection,the cdk5 level in cerebella was decreased by 34.17%(P<0.05,n=6),spheroid number decreased by 30.76%(P<0.05,n=6),number of surviving Purkinje cells increased by 300%(P<0.05,n=8),and phosphorylation of cytoskeletons decreased by 16.32%(P<0.05,n=6).Conclusion rAAV-cdk5-siRNA-GFP can lower the expression of cdk5 gene effectively,reduce the number of axonal spheroids,delay the death of Purkinje neurons and attenuate the hyperphosphorylation of cytoskeletons in npc mice significantly.Cdk5 plays an essential role in the neurodegenerative process and may become a new target for the treatment of NPC.更多还原