Morphological and functional characterization of the consequences of the oxidative stress experimentally induced on skin cell models in vitro

During the skin ageing, the produced radical species make unstable the "proliferation / differentiation / apoptosis" coupling of epidermal cells; we propose to study this loss of cell integrity, by a double original and complementary approach: - the establishment of proteomic comparative profiles, by spectrofluorimetric, 2D chromatographic/mass spectrometry techniques, - the exploration of cell growth and morphology, by a spectroscopic and topographic study by atomic force microscopy. This work will allow identifying the better biomarker(s) of skin ageing modeled in vitro by a chosen chemical treatment using glyphosate. Original molecules with cell protection effect, able to correct the induced morphological and/or functional disorders could also been identified. Our first results revealed cell morphology of a line of keratinocytes grown on different substrates. A glyphosate dose-effect was noted through an important cell destructuration. Preliminary force spectroscopy measurements on cells revealed also specific interactions with glyphosate. These experimental results based on AFM investigation should highlight the first steps of the oxidative stress mechanism, by visualization and quantification of the phenomenon after its induction at the individual cell scale.