Effect of GSK-3 overactivation on neurofilament phosphorylation.
In this study, we studied the effect of glycogen synthase kinase-3 (GSK-3) overactivation on neurofilament phosphorylation in cultured cells. After N2a cells were treated with the specific inhibitor (wortmannin) of phosphoinositol-3 kinase (PI-3K) or treated with wortmannin and the specific inhibitor (LiCl) of glycogen synthase kinase-3 (GSK-3), GSK-3 activity and neurofilament phosphorylation were detected by using GSK-3 activity assay, Western blots and immunofluoresence. Our results showed that after treatment of N2a cells with wortmannin for 1 h, overactivation of GSK-3 caused a reduced staining with antibody SMI32 and an enhanced staining with antibody SMI31. When N2a cells were treated with wortmannin and LiCl, the activity of GSK-3 was reduced substantially. At the same time, the phosphorylation of neurofilament was also reduced. The study demonstrated that overactivation of GSK-3 induced hyperphosphorylation of neurofilament and suggested that in vitro overactivation of GSK-3 resulted in neurofilament hyperphosphorylation and this may be the underlying mechanism for Alzheimer's disease.
Chen
Juan
J
Department of Biochemistry and Molecular Biology, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China.
Zhou
Jie
J
Feng
Youmei
Y
Wang
Jianzhi
J
D000544:Alzheimer Disease / Q000473:pathology; D000730:Androstadienes / Q000494:pharmacology*; D000818:Animals; D038362:Glycogen Synthase Kinase 3 / Q000037:antagonists & inhibitors / Q000378:metabolism*; D051379:Mice; D009447:Neuroblastoma / Q000201:enzymology / Q000473:pathology*; D016900:Neurofilament Proteins / Q000378:metabolism*; D000081082:Phosphoinositide-3 Kinase Inhibitors; D010766:Phosphorylation; D014407:Tumor Cells, Cultured; D000077191:Wortmannin
D000730:Androstadienes; D016900:Neurofilament Proteins; D000081082:Phosphoinositide-3 Kinase Inhibitors; D038362:Glycogen Synthase Kinase 3; D000077191:Wortmannin