The investigated PC12 cells stop dividing and undergo terminal differentiation when treated with nerve growth factor, making this cell line a useful model system for neuronal differentiation. The cells were additionally treated with heat shock (45 °C), the specific inhibitor of p38 mitogen-activated protein kinase (SB 203580, 2 µM), and an inhibitor of extracellular signal-regulated MAP kinase (U 0126, 10 µM). Three independent experiments were performed.
Exposure duration: continuous for 30 or 60 min
experiments on neuritogenesis
Exposure duration: continuous for 10, 20, 30, or 60 min
cell survival studies
|Exposure duration||continuous for 30 or 60 min|
|Additional info||experiments on neuritogenesis|
The frequency of neurite outgrowth was approximately 10-fold greater in 2.45 GHz exposed cells than in only nerve growth factor treated cells. Incubation of the cells with the specific inhibitor of p38 mitogen-activated protein kinase resulted in marked inhibition of the microwave irradiation-induced neurite outgrowth. Also, activation of the transcription factor CREB induced by microwave irradiation was inhibited by the specific inhibitor of p38 mitogen-activated protein kinase.
These data indicate that p38 mitogen-activated protein kinase is responsible for the survival of the investigated cells and might induce neurite outgrowth via a CREB signaling pathway when subjected to microwave irradiation.