Effects of fluvoxamine on nerve growth factor-induced neurite outgrowth inhibition by dexamethasone in PC12 cells

In the present study, we examined the effects of fluvoxamine on nerve growth factor (NGF)-induced neurite outgrowth inhibition by dexamethasone (DEX) in PC12 cells. Fluvoxamine increased NGF-induced neurite outgrowth. Compared with co-treatment with NGF and fluvoxamine, p-Akt levels were higher than the values without fluvoxamine. The phosphorylated extracellular regulated kinase 1/2 levels were slightly increased by co-treatment with NGF and fluvoxamine. Fluvoxamine concentration-dependently improved NGF-induced neurite outgrowth inhibition by DEX. Fluvoxamine also improved the decrease in the NGF-induced p-Akt level caused by DEX. Interestingly, the sigma-1 receptor antagonist NE-100 blocked the improvement effects of fluvoxamine on NGF-induced neurite outgrowth inhibition by DEX. The selective sigma-1 receptor agonist PRE-084 also improved NGF-induced neurite outgrowth inhibition by DEX, which is blocked by NE-100. These results indicate that the improvement effects of fluvoxamine on NGF-induced neurite outgrowth inhibition by DEX may be attributable to the phosphorylation of Akt and the sigma-1 receptor.