900 MHz modulated electromagnetic fields accelerate the clathrin-mediated endocytosis pathway.
We report new data regarding the molecular mechanisms of GSM-induced increase of cell endocytosis rate. Even though endocytosis represents an important physical and biological event for cell physiology, studies on modulated electromagnetic fields (EMF) effects on this process are scarce. In a previous article, we showed that fluid phase endocytosis rate increases when cultured cells are exposed to 900 MHz EMF similar to mobile phones' modulated GSM signals (217 Hz repetition frequency, 576 micros pulse width) and to electric pulses similar to the GSM electrical component. Trying to distinguish the mechanisms sustaining this endocytosis stimulation, we exposed murine melanoma cells to Lucifer Yellow (LY) or to GSM-EMF/electric pulses in the presence of drugs inhibiting the clathrin- or the caveolin-dependent endocytosis. Experiments were performed at a specific absorption rate (SAR) of 3.2 W/kg in a wire patch cell under homogeneously distributed EMF field and controlled temperature (in the range of 28.5-29.5 degrees C). Thus, the observed increase in LY uptake was not a thermal effect. Chlorpromazine and ethanol, but not Filipin, inhibited this increase. Therefore, the clathrin-dependent endocytosis is stimulated by the GSM-EMF, suggesting that the cellular mechanism affected by the modulated EMF involves vesicles that detach from the cell membrane, mainly clathrin-coated vesicles.
Moisescu
Mihaela G
MG
Centre National de la Recherche Scientifique, UMR 8121-Vectorology and Gene Transfer, Institut Gustave Roussy, 39 rue Camille Desmoulins, Villejuif, France.
Leveque
Philippe
P
Verjus
Marie-Ange
MA
Kovacs
Eugenia
E
Mir
Lluis M
LM
D000818:Animals; D002746:Chlorpromazine / Q000633:toxicity; D002966:Clathrin / Q000494:pharmacology*; D004574:Electromagnetic Fields; D004705:Endocytosis / Q000187:drug effects / Q000502:physiology / Q000528:radiation effects*; D000431:Ethanol / Q000633:toxicity; D005372:Filipin / Q000633:toxicity; D007546:Isoquinolines / Q000378:metabolism; D051379:Mice; D013696:Temperature
D002966:Clathrin; D007546:Isoquinolines; D000431:Ethanol; D005372:Filipin; C017475:lucifer yellow; D002746:Chlorpromazine