Overexpression of dishevelled-1 attenuates wortmannin-induced hyperphosphorylation of cytoskeletal proteins in N2a cell

Abstract

Aim: To investigate the effect of dishevelled-1 (DVL-1) on wortmannin-induced Alzheimer-like hyperphosphorylation of cytoskeletal proteins in mouse neuroblastoma 2a (N2a) cells. Methods: Cultured N2a cells were transitorily transfected with DVL-1 expression plasmid using Lipofectamine™ 2000. Western blot and immunofluorescence microscopy were used to measure the phosphorylation of neurofilament and tau. Results: Level of phosphorylated neurofilament at SMI31 epitope and phosphorylated tau determined by PHF-1 was increased at 1 h and 3 h and back to normal at 6 h after wortmannin 1 μmol/L treatment. The highest level of phosphorylated neurofilament and phosphorylated tau was seen at 1 h and 3 h after wortmannin treatment, respectively. When DVL-1 protein was overexpressed, the hyperphosphorylation of neurofilament at SMI31 and SMI32 epitopes and tau at PHF-1 (Ser-396/404), M4 (Thr-231/Ser-235), and Tau-1 (Ser-198/199/202) epitopes was attenuated. Conclusion: Overexpression of mouse DVL-1 protein inhibits wortmannin-induced hyperphosphorylation of neurofilament and tau in N2a cells. © 2005 CPS and SIMM.