The Neuroprotective Effects of Cyclin-dependent Kinase-5 Inhibition in Mice with Niemann-Pick Disease Type C

摘要

In order to investigate the neuroprotective effects of cyclin-dependent kinase-5 (cdk-5) inhibition in mice with Niemann-Pick disease type C (NPC) (npc-/-), recombinant adeno-associated virus (rAAV) carrying the small interfering RNA (siRNA) specific for cdk-5 gene was injected into 3-day-old npc-/-mice intracerebroventricularly. The rAAV-GFP-injected age-matched npc-/-mice and non-surgery age-matched npc-/-mice were employed as controls (n=6―10/group). From the 4th to 8th week after the treatment, mice were weighed, and evaluated for limb motor activity by using the coat hanger test once a week. Eight-week-old npc-/-mice were sacrificed by decapitation, and brains were quickly dissected and halved sagittally. Immunohistochemistry, Western blotting, and HE staining were used to evaluate the neuropathology in npc-/-mice. The results showed that rAAV-cdk-5-siRNA-GFP significantly reduced the number of axonal spheroids, delayed the death of Purkinje neurons, ameliorated motor defects in npc-/-mice, and significantly attenuated the hyper-phosphorylation of tau proteins. These data suggested that inhibition of cdk-5 activity has neuropro-tective effect on neurons in NPC mice.