Study type: Medical/biological study (experimental study)

Microwave irradiation induces neurite outgrowth in PC12m3 cells via the p38 mitogen-activated protein kinase pathway. med./bio.

Published in: Neurosci Lett 2008; 432 (1): 35-39

Aim of study (acc. to author)

This study was conducted to study the effects of microwave irradiation on differentiation and signal transduction in a rat cell line.

Background/further details

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.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 2.45 GHz
Exposure duration: continuous for 30 or 60 min
experiments on neuritogenesis
Exposure 2: 2.45 GHz
Exposure duration: continuous for 10, 20, 30, or 60 min
cell survival studies

Exposure 1

Main characteristics
Frequency 2.45 GHz
Type
Exposure duration continuous for 30 or 60 min
Additional info experiments on neuritogenesis
Exposure setup
Exposure source
  • microthermy
Additional info For experiments on neuritogenesis, the cells were plated in 25-cm² flasks and then treated with NGF and/or exposed to MW radiation at 37 °C using microthermy and a cooling system.
Parameters
Measurand Value Type Method Mass Remarks
power 25 W - - - -
power 50 W - - - -
power 75 W - - - -
power 100 W - - - -
power 200 W - - - -

Exposure 2

Main characteristics
Frequency 2.45 GHz
Type
Exposure duration continuous for 10, 20, 30, or 60 min
Additional info cell survival studies
Exposure setup
Exposure source
Additional info For cell survival studies, the cells were plated in 25-cm² flasks and then treated with NGF or exposed to MW radiation at 37 °C or to a heat shock of 42 or 45 °C.
Parameters
Measurand Value Type Method Mass Remarks
power 25 W - - - -
power 50 W - - - -
power 75 W - - - -
power 100 W - - - -
power 200 W - - - -

Exposed system:

Methods Endpoint/measurement parameters/methodology

Investigated system:
Time of investigation:
  • before exposure
  • after exposure

Main outcome of study (acc. to author)

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.

Study character:

Study funded by

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