ID Number		1795
Study Type		In Vitro
Model		900 MHz (GSM) exposure to keratinocytes (analysis of gene expression) and a pigmented skin model (analysis of epidermal homoeostasis).
Details		RHE keratinocytes were exposed to 900 MHz (GSM) using the exposure system described by Laval et al (Bioelectromagnetics 21:255-263). No exposure conditions were provided other than cells were maintained at 37 degrees. Following exposure, cells were incubated for an additional 2 or 18 hours post exposure and analyzed for gene expression profiles. The authors report increased expression of neuromedial B (bombesin-related peptide family, activates MAPK and raf-1), c-myc, c-jun, jun-B suggesting activation of a cascade of protein-1 transcription factors of proinflammatory and stress related genes. This was also corroborated by increases in IL-1R1, IL-2R alpha, TNF-R1, TGF-beta R2, and Nos-2. In addition, hsp70, hsp47, hsp40, hsp90A, hspA5 and hsp90B were also increased to relatively high levels. In contrast, hsp27 was not increased. RF exposure also decreased expression of several genes involved in cell structure or oxidative stress response. Most expression increases were on the order of 2-6 fold, although HSP70 and hsp47 were elevated 15 fold. The authors suggest these findings indicate an inflammatory response that subsided 18 hours after exposure. AUTHORS' ABSTRACT: Simon et al. 2013 (IEEE #5578): Exposure to electromagnetic radiations (EMR) produced by mobile phone concerns half the world's population and raises the problem of their impact on human health. In this study, we looked at the effects of mobile phone exposure (GSM basic, 900 MHz, SAR 2 mW g(-1) , 6 h) on a model of pigmented skin. We have analysed the expression and localization of various markers of keratinocyte and melanocyte differentiation 2, 6, 18 and 24 h after EMR exposure of reconstructed epidermis containing either only keratinocytes or a combination of keratinocytes and melanocytes grown on dead de-epidermized dermis, using histology, immunohistochemistry and Western blot. No changes were found in epidermal architecture, localization of epidermal markers, presence of apoptotic cells and the induction of p53 in both types of epidermis (with or without melanocytes) after exposure to EMR. In pigmented reconstructs, no change in the location and dendricity of melanocytes and in melanin transfer to neighbouring keratinocytes was detected after EMR exposure. Loricrin, cytokeratin 14 were significantly decreased at 6 h. The level of all markers increased at 24 h as compared to 6 h post-EMR exposure, associated with a significant decrease of the 20S proteasome activity. Our data indicate that exposure to 900 MHz frequency induces a transient alteration of epidermal homoeostasis, which may alter the protective capacity of the skin against external factors. Presence or absence of melanocytes did not modify the behaviour of reconstructs after EMR exposure.
Findings		Effects
Status		Completed With Publication
Principal Investigator		University Bordeaux, France - djavad.mossalayi@imparph.u-bordeaux2.fr
Funding Agency		?????
Country		FRANCE
References		Ennamany, R et al. J Invest Dermatol, (2008) 128:743-746 Simon, D et al. Int J Cosmet Sci., (2013) 35:27-34
Comments		No exposure conditions, SAR, length of time, culture conditions, field uniformity - nothing. There is also no indication of how they verified maintaining 37 degrees C (i.e., how did they insure no hot spots). The exposure system paper (Laval et al) suggests the system can be used for higher exposures maintaining uniformity of SAR, which suggests the authors of this study may have used very high SAR for exposure.