Electromagnetic fields affect transcript levels of apoptosis-related genes in embryonic stem cell-derived neural progenitor cells
Teodora Nikolova*, Jaroslaw Czyz*,1, Alexandra Rolletschek*, Przemyslaw Blyszczuk*, Jörg Fuchs*, Gabriele Jovtchev*, Jürgen Schuderer†, Niels Kuster† and Anna M. Wobus*,2
* Institute of Plant Genetics and Crop Plant Research (IPK), Gatersleben, Germany;
† Foundation for Research on Information Technologies in Society (IT’IS), Zurich, Switzerland
2 Correspondence: In Vitro Differentiation Group, Institute of Plant Genetics and Crop Plant Research (IPK), Correnstr.3, D-06466 Gatersleben, Germany. E-mail: email@example.com
In the present study we aimed to investigate the effects of radiofrequency (RF) and extremely low frequency (ELF) electromagnetic fields (EMF) on the transcript level of cell cycle regulatory and apoptosis-related genes, on proliferation, apoptosis and chromosomal damage in neural progenitors generated from pluripotent mouse embryonic stem cells in vitro.
1. ELF-EMF exposure affected bcl-2, bax, and GADD45 transcript levels in embryonic stem (ES) cell-derived neural progenitors
Pluripotent mouse ES cells were cultured as aggregates ("embryoid bodies," EBs) for 4 days followed by differentiation induction into neural progenitor and neuronal cells (Fig. 1 ). Differentiation of 4d EBs resulted in up to 85% of nestin-positive neural progenitor cells 4–6 days after plating. The cells were exposed to 50 Hz powerline ELF-EMF for 48 h at day 4+4, differentiated into the neuronal lineage, and analyzed at various time points. Magnetic flux density of 2 mT was applied with 5 min ON/ 30 min OFF intermittency cycles. The ELF exposure setup allowed studies under "blind" conditions and the control of temperature differences (±0.2°C) for sham- and ELF-EMF-exposed cultures. Quantitative (Q) RT-PCR analysis (Fig. 2 ) showed a relative increase of bcl-2 and bax mRNA levels at stage 4+11d relative to transcript levels of GAPDH, used as an internal standard. Transcript levels of the "growth arrest and DNA damage-inducible gene" GADD45 were down-regulated at terminal stage (4+23d, Fig. 2A ). Immunofluorescence analysis of EMF- and sham-exposed cells, however, showed no differences in the intracellular distribution and number of cells expressing neuronal (ßIII-tubulin, tyrosin hydroxylase, TH) or astrocytic (glial fibrillary acidic protein, GFAP) proteins.
Extremely low frequency electromagnetic fields as effectors of cellular responses in vitro: Possible immune cell activation
Article first published online: 26 JUL 2004
Copyright © 2004 Wiley-Liss, Inc.
Journal of Cellular Biochemistry
Volume 93, Issue 1, pages 83–92, 1 September 2004
There is presently an intense discussion if electromagnetic field (EMF) exposure has consequences for human health. This include exposure to structures and appliances that emit in the extremely low frequency (ELF) range of the electromagnetic spectrum, as well as emission coming from communication devices using the radiofrequency part of the spectrum. Biological effects of such exposures have been noted frequently, although the implication for specific health effects is not that clear. The basic interaction mechanism(s) between such fields and living matter is unknown. Numerous hypotheses have been suggested, although none is convincingly supported by experimental data. Various cellular components, processes, and systems can be affected by EMF exposure. Since it is unlikely that EMF can induce DNA damage directly, most studies have examined EMF effects on the cell membrane level, general and specific gene expression, and signal transduction pathways. In addition, a large number of studies have been performed regarding cell proliferation, cell cycle regulation, cell differentiation, metabolism, and various physiological characteristics of cells. Although 50/60 Hz EMF do not directly lead to genotoxic effects, it is possible that certain cellular processes altered by exposure to EMF indirectly affect the structure of DNA causing strand breaks and other chromosomal aberrations. The aim of this article is to present a hypothesis of a possible initial cellular event affected by exposure to ELF EMF, an event which is compatible with the multitude of effects observed after exposure. Based on an extensive literature review, we suggest that ELF EMF exposure is able to perform such activation by means of increasing levels of free radicals. Such a general activation is compatible with the diverse nature of observed effects. Free radicals are intermediates in natural processes like mitochondrial metabolism and are also a key feature of phagocytosis. Free radical release is inducible by ionizing radiation or phorbol ester treatment, both leading to genomic instability. EMF might be a stimulus to induce an “activated state” of the cell such as phagocytosis, which then enhances the release of free radicals, in turn leading to genotoxic events. We envisage that EMF exposure can cause both acute and chronic effects that are mediated by increased free radical levels: (1) Direct activation of, for example macrophages (or other cells) by short-term exposure to EMF leads to phagocytosis (or other cell specific responses) and consequently, free radical production. This pathway may be utilized to positively influence certain aspects of the immune response, and could be useful for specific therapeutic applications. (2) EMF-induced macrophage (cell) activation includes direct stimulation of free radical production. (3) An increase in the lifetime of free radicals by EMF leads to persistently elevated free radical concentrations. In general, reactions in which radicals are involved become more frequent, increasing the possibility of DNA damage. (4) Long-term EMF exposure leads to a chronically increased level of free radicals, subsequently causing an inhibition of the effects of the pineal gland hormone melatonin. Taken together, these EMF induced reactions could lead to a higher incidence of DNA damage and therefore, to an increased risk of tumour development. While the effects on melatonin and the extension of the lifetime of radicals can explain the link between EMF exposure and the incidence of for example leukaemia, the two additional mechanisms described here specifically for mouse macrophages, can explain the possible correlation between immune cell system stimulation and EMF exposure. © 2004 Wiley-Liss, Inc.
Electromagnetic field effects on cells of the immune system: the role of calcium signaling
Research Medicine and Radiation Biophysics Division, Lawrence Berkeley Laboratory, University of California 94720.
During the past decade considerable evidence has accumulated demonstrating that nonthermal exposures of cells of the immune system to extremely low-frequency (ELF) electromagnetic fields (< 300 Hz) can elicit cellular changes that might be relevant to in vivo immune activity. A similar responsiveness to nonionizing electromagnetic energy in this frequency range has also been documented for tissues of the neuroendocrine and musculoskeletal system. However, knowledge about the underlying biological mechanisms by which such fields can induce cellular changes is still very limited. It is generally believed that the cell membrane and Ca(2+)-regulated activity is involved in bioactive ELF field coupling to living systems. This article begins with a short review of the current state of knowledge concerning the effects of nonthermal levels of ELF electromagnetic fields on the biochemistry and activity of immune cells and then closely examines new results that suggest a role for Ca2+ in the induction of these cellular field effects. Based on these findings it is proposed that membrane- mediated Ca2+ signaling processes are involved in the mediation of field effects on the immune system.
Elisha Gray wrote:You notice this effect when the cell phone in your hand appears to feel hot (the device isn't hot its just slowly cooking you).
Elisha Gray wrote:In your permaculture planning you can treat this energy source like wind or any other on your property that needs mitigation. Meanwhile try to take advantage of the benefits these gadgets bring... Your going to be dealing with the ill effects either way.
Paul Abbott wrote:Ground yourself or "earth" yourself... check it out... http://www.earthing.com/
Ben Stallings wrote:Can you point me to an existing study, or should I test it myself?
Randy Gibson wrote:
I realize there are things that can be avoided, as well as things that cannot. I try to be proactive in my health as well as with my children.
I keep seeing comments such as; it's not so bad, the signal is relatively weak, etc. I'd prefer "has no effect at all" etc.