Neurofibrillary tangles (NFTs) are one of the neuro-pathological hallmarks ofAlzheimer's disease (AD) and abnormally hyperphosphorylated tau is the major protein of NFTs It wasreported that cyclin-dependent kinase...Neurofibrillary tangles (NFTs) are one of the neuro-pathological hallmarks ofAlzheimer's disease (AD) and abnormally hyperphosphorylated tau is the major protein of NFTs It wasreported that cyclin-dependent kinase5 (Cdk-5) could phosphorylate tau atmost AD-related epitopesin vivo. In this study, we investigated the effect of cdk-5 overexpression on tauhyperphosphbrylation in neuroblastoma N2a cells. We demonstrated that Overexpression of cdk-5 whichresulted in a 3.5-fold Cdk-5 activation in thetransfected cells induced a dramatic increase inphosphorylation of tau at severalphosphorylatiosites. Overexpression of cdk-5 led to a reducedstaining with antibody Tau-1 and an enhanced staining with antibody PHF-1, suggestinghy-perphosphorylation of tau at Serl99/202 and Ser396/404 sites. It implies that in vitroOverexpression of cdk-5 leads to Cdk-5 overactivation and tau hyperphosphorylation may be theunderline mechanism.展开更多
In Alzheimer抯 disease (AD), hyperphosphorylation of tau may be the underlying mechanism for the cytoskeletal abnormalities and neuronal death. It was reported that cy-clin-dependent kinase5 (cdk-5) could phosphorylat...In Alzheimer抯 disease (AD), hyperphosphorylation of tau may be the underlying mechanism for the cytoskeletal abnormalities and neuronal death. It was reported that cy-clin-dependent kinase5 (cdk-5) could phosphorylate tau at most AD-related epitopes in vitro. In this study, we investigated the effect of cdk-5 overexpression on tau phosphorylation and spatial memory in rat. We demonstrated that 24 h after transfection into rat hippocampus, cdk-5 was overexpressed and induced a reduced staining with antibody tau-1 and an enhanced staining with antibodies 12e8 and PHF-1, suggesting hyperphosphorylation of tau at Ser199/202, Ser262/356 and Ser396/404 sites. Additionally, the cdk-5 transfected rats showed long latency to find the hidden platform in Morris water maze compared to the control rat. 48 h after transfection, the level of cdk-5 was decreased significantly, and the latency of rats to find the hidden platform was prolonged. It implies that in vivo overexpression of cdk-5 leads to impairment of spatial memory in rat and tau hyperphosphorylation may be the underlying mechanism.展开更多
基金Supported by the National Natural Science Foundation of China (39925012 30100057+1 种基金30170221) the Science and Technology Founda tion Committee Foundurion of China(G1999054007) and National Youth Sci ence Foundation of China(39925012)
文摘Neurofibrillary tangles (NFTs) are one of the neuro-pathological hallmarks ofAlzheimer's disease (AD) and abnormally hyperphosphorylated tau is the major protein of NFTs It wasreported that cyclin-dependent kinase5 (Cdk-5) could phosphorylate tau atmost AD-related epitopesin vivo. In this study, we investigated the effect of cdk-5 overexpression on tauhyperphosphbrylation in neuroblastoma N2a cells. We demonstrated that Overexpression of cdk-5 whichresulted in a 3.5-fold Cdk-5 activation in thetransfected cells induced a dramatic increase inphosphorylation of tau at severalphosphorylatiosites. Overexpression of cdk-5 led to a reducedstaining with antibody Tau-1 and an enhanced staining with antibody PHF-1, suggestinghy-perphosphorylation of tau at Serl99/202 and Ser396/404 sites. It implies that in vitroOverexpression of cdk-5 leads to Cdk-5 overactivation and tau hyperphosphorylation may be theunderline mechanism.
基金This work was supported in part by the National Natural Science Foundation of China(Grant Nos.39925012,30100057&30170221)Science and Technology Committee of China(G1999054007)National Educational Committee of China(2001-171).
文摘In Alzheimer抯 disease (AD), hyperphosphorylation of tau may be the underlying mechanism for the cytoskeletal abnormalities and neuronal death. It was reported that cy-clin-dependent kinase5 (cdk-5) could phosphorylate tau at most AD-related epitopes in vitro. In this study, we investigated the effect of cdk-5 overexpression on tau phosphorylation and spatial memory in rat. We demonstrated that 24 h after transfection into rat hippocampus, cdk-5 was overexpressed and induced a reduced staining with antibody tau-1 and an enhanced staining with antibodies 12e8 and PHF-1, suggesting hyperphosphorylation of tau at Ser199/202, Ser262/356 and Ser396/404 sites. Additionally, the cdk-5 transfected rats showed long latency to find the hidden platform in Morris water maze compared to the control rat. 48 h after transfection, the level of cdk-5 was decreased significantly, and the latency of rats to find the hidden platform was prolonged. It implies that in vivo overexpression of cdk-5 leads to impairment of spatial memory in rat and tau hyperphosphorylation may be the underlying mechanism.
