Plasticité membranaire et fonctions cellulaires

The activity of the Biophotonics team was originally focused on the interaction of light with different classes of chromophores of biological and / or biomedical interest.

Some of these chromophores exhibit a high triplet state quantum yields that enable reactive oxygen species (ROS) production. Such agents are defined as photosensitizer. We have already shown that it became possible to use these molecules to disturb the membrane models in a fine and controlled way [1]. Our main goal today is to achieve greater levels of membrane complexity, to further explore the involved mechanisms, but also to strengthen their relevance to the biological point of view. Our aim is not only to change the composition of the model membranes on which we work, but mainly to better understand the relationship between membrane composition, its morphology and one specific biological activity. In this view, biomimetic membrane models such as proteo-liposomes (including i.e. ATPsynthase) are used [2] and structured illumination microscopy is now implemented in our lab for dynamic studies of mitochondrial membrane architecture [3]. Chemical characterization, kinetics of the photo-induced oxidation on phospholipid membrane, as well as intercellular communication can be studied by Raman and fluorescence spectroscopy of single nanoscale vesicles in the optical trap [4,5]. Moreover, taking into account the importance of oxygen in membrane oxidation processes, we have developed an original approach using both micro fluidic set-up and frequency domain fluorescence lifetime laser sheet microscopy in order to monitor oxygen gradient and diffusion in biological systems [6] 

References

[1] Heuvingh, J. and Bonneau, S. Asymmetric Oxidation of Giant Vesicles Triggers Curvature-Associated Shape Transition and Permeabilization. Biophys. J. 97, 2904-2912 (2009).

[2] Almendro-Vedia V.G., Natale P., Mell M., Bonneau S., Monroy F., Joubert F., López-Montero I. Nonequilibrium fluctuations of lipid membranes by the rotating motor protein F1F0-ATP synthase. Proc Natl Acad Sci U S A14(43):11291-11296 (2017).

[3] Shao, L., Kner, P., Rego, E.H. and Gustafsson, M.G.L. Super-resolution 3D microscopy of live whole cells using structured illumination. Nature Meth. 8, 1044-1046 (2011).

[4] Bour, A., Kruglik, S.G., Chabanon, M., Rangamani, P., Puff, N. and Bonneau, S. Lipid unsaturation properties govern the sensitivity of membranes to photo-induced oxidative stress. doi: https://doi.org/10.1101/451591. (2019)

[5] Kruglik, S.G., Royo F., Guigner, J-M. et al. Raman tweezers microspectroscopy of circa 100-nm extracellular vesicles. Nanoscale in press (2019)

[6] Monmeyran, A., Thomen, P., Jonquiere, H., Sureau, F., Li, C., Plamont, M-A., Douarche, C., Casella, J-F., Gautier, A. & Henry, N.The inducible chemical-genetic fluorescent marker FAST outperforms classical fluorescent proteins in the quantitative reporting of bacterial biofilm dynamics. Sci. Report 8, 10336 (2018).