Low intensity RF impact on an in vitro model of the rat BBB
Abstract
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RF from GSM mobiles (<2 W/kg) can reach more and more people. Recent in vivo study showed neurons and astrocytes stimulation after such an exposition of low intensity RF. We plan in vitro studies based on a Blood-Brain Barrier model to focus on the cellular impact of such exposition.
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Partners
VigiCell – Villejuif
XLIM – Université de Limoges – UMR6172 CNRS
INERIS – Verneuil-en-Halatte
Contact
Jean-Emmanuel Gilbert VigiCell
Duration
12 months
Summary
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In order to study the effects of an exposure of the rat central nervous system (CNS) to radiofrequencies (RF), the Experimental Toxicology unit of INERIS has shown modifications of function markers: astrocyte inflammation (GFAP) and modification of brain activity (c-Fos) all in non-thermal conditions of specific absorption rates (SAR). Results are correlated with SAR levels. Amplitude of the effect witnessed for GFAP increases with SAR levels (effects at 1,5W/kg These various effects, even if they do not evoke a direct sanitary risk (no anatomical or behavioural correlations), are nevertheless evidence of an interaction between RF and and the biological system constituted by the CNS. The former could stem from local modifications of the properties of the blood-brain barrier (BBB). A deeper understanding of the mechanisms at stake is necessary to more thoroughly evaluate the potential sanitary risk faced by the general population after such exposures. Indeed, the impact of RF exposures coupled to possible additional factors such as chronic inflammation, drug treatment, exposure to pollutants etc. could prove different for each individual case. In vivo, animal-based approach has proved time-consuming, expensive and often poorly relevant given the variety of the situations to study, and the nature of the latter, in human populations. In contrast, in vitro approaches could prove all the more useful and efficient in order to finely characterise effects of low-intensity RF on the BBB and elaborate both a validation and deeper understanding of the phenomenon already observed and documented.
The proposed study will initially be carried out in physiological conditions, in order to attempt to reproduce the effects observed in vivo and refine the various observations. Then, inflammatory conditions will be implemented, with optional aggravating factors. The innovative BBB model constructed is constituted by primary brain endothelial cells and astrocytes isolated in young rats. One of the main interests is that in vitro and in vivo data can be correlated in a much reliable way due to the absence of species-related issues.
The hypothesis to be investigated is a damage to the endothelium potentially implicating:
1/ Endothelial cell dysfunction or direct damage:
- Measurement of paracellular permeability of hydrophilic compounds (sucrose, Lucifer yellow) and of transendothelial electrical resistance
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- Passage measurement of compounds undergoing endocytosis (albumin)
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- Permeability measurement of efflux pumps substrates (Daunorubicin)
2/ Opening of the BBB, exposing the cerebral compartment. The effects will be investigated on astrocytes and neurons in culture.
3/ The design of this model itself allows for a differential study of responses elicited in the 2 cell types implicated, namely endothelial cells and astrocytes. Investigation focus on:
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- Expression and localization of tight junctions-specific proteins on endothelial cells.
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- GFAP expression quantification (mRNA or protein) in astrocytes.
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- Classical toxicology/toxicity assays on both cell types such as micronuclei counting, comet assays, XTT assays, oxidative stress measurements.
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This project needs the specific skills of a partnership of three entities specialized on GSM studies:
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- VigiCell: company specialized on new physiology and cellular biology approaches for predictive toxicology in healthcare and environment care. VigiCell has already conduct two clinical in vivo studies related on GSM toxicology.
- Experimental toxicology department of INERIS (Institut National de l’Environnement Industriel et des Risques), actively participated in several studies such as COMOBIO, ACI and RAMP).
- The academic laboratories XLIM (UMR 6172 CNRS-Limoges University) is integrated in the department entitled “microwaves and associated systems” (OSA). XLIM is implicated in several research programs turned to “microwaves and healthcare”. They are expert in all physical approaches of radio frequencies.
Key words : Metrology ; Dosimetry ; in vitro studies ; Blood-Brain Barrier ; GSM Radio Frequencies de type GSM ; Physiological and toxicological effect; Cofactor.