title: Calcium signalling in human neutrophil cell lines is not affected by low-frequency electromagnetic fields.
abstract: We are increasingly exposed to low-frequency electromagnetic fields (LF EMFs) by electrical devices and power lines, but if and how these fields interact with living cells remains a matter of debate. This study aimed to investigate the potential effect of LF EMF exposure on calcium signalling in neutrophils. In neutrophilic granulocytes, activation of G-protein coupled receptors leads to efflux of calcium from calcium stores and influx of extracellular calcium via specialised calcium channels. The cytoplasmic rise of calcium induces cytoskeleton rearrangements, modified gene expression patterns, and cell migration. If LF EMF modulates intracellular calcium signalling, this will influence cellular behaviour and may eventually lead to health problems. We found that calcium mobilisation upon chemotactic stimulation was not altered after a short 30 min or long-term LF EMF exposure in human neutrophil-like cell lines HL-60 or PLB-985. Neither of the two investigated wave forms (Immunent and 50 Hz sine wave) at three magnetic flux densities (5 μT, 300 μT, and 500 μT) altered calcium signalling in vitro. Gene-expression patterns of calcium-signalling related genes also did not show any significant changes after exposure. Furthermore, analysis of the phenotypical appearance of microvilli by scanning electron microscopy revealed no alterations induced by LF EMF exposure. The findings above indicate that exposure to 50 Hz sinusoidal or Immunent LF EMF will not affect calcium signalling in neutrophils in vitro.
authors.affiliation: Cell Biology and Immunology Group, Wageningen University, The Netherlands.
authors.forename: Lieke A
authors.initials: LA
authors.lastname: Golbach
authors.affiliation: Lab of Biophysics and Wageningen NMR Centre, Wageningen University, The Netherlands.
authors.forename: John G M
authors.initials: JG
authors.lastname: Philippi
authors.affiliation: Immunent BV, Veldhoven, The Netherlands.
authors.forename: Jan J M
authors.initials: JJ
authors.lastname: Cuppen
authors.affiliation: Cell Biology and Immunology Group, Wageningen University, The Netherlands.
authors.forename: Huub F J
authors.initials: HF
authors.lastname: Savelkoul
authors.affiliation: Cell Biology and Immunology Group, Wageningen University, The Netherlands.
authors.forename: B M Lidy
authors.initials: BM
authors.lastname: Verburg-van Kemenade
mesh_terms: D001692:Biological Transport / Q000528:radiation effects; D002118:Calcium / Q000378:metabolism; D015220:Calcium Channels / Q000235:genetics; D020013:Calcium Signaling / Q000528:radiation effects*; D002460:Cell Line; D004574:Electromagnetic Fields / Q000009:adverse effects*; D005786:Gene Expression Regulation / Q000528:radiation effects; D006801:Humans; D007700:Kinetics; D008871:Microvilli / Q000378:metabolism / Q000528:radiation effects / Q000648:ultrastructure; D009504:Neutrophils / Q000166:cytology* / Q000378:metabolism / Q000528:radiation effects* / Q000648:ultrastructure; D010641:Phenotype; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D044169:Receptors, Calcium-Sensing / Q000235:genetics; D013997:Time Factors
chemical_list: D015220:Calcium Channels; D012333:RNA, Messenger; D044169:Receptors, Calcium-Sensing; D002118:Calcium
keywords: HL-60; LF EMF; calcium influx; microvilli; neutrophilic granulocytes