Overexpression of dishevelled-1 attenuates wortmannin-induced hyperphosphorylation of cytoskeletal proteins in N2a cell.
To investigate the effect of dishevelled-1 (DVL-1) on wortmannin-induced Alzheimer-like hyperphosphorylation of cytoskeletal proteins in mouse neuroblastoma 2a (N2a) cells. 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. 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 micromol/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. Overexpression of mouse DVL-1 protein inhibits wortmannin-induced hyperphosphorylation of neurofilament and tau in N2a cells.