Over the last ten years, the joint effort of the platform PLATIM and the laboratory of Plant Development and Reproduction (RDP) has developed a strong and recognized expertise in the imaging and quantification of cell mechanical properties in living plant issues. Specific pipelines have been developed to map and quantify:

1. Wall mechanical properties through direct measurements of key parameters such as wall stiffness, adhesion, and resistance to piercing, using AFMs and nano-indenters 

2. Cell hydrostatic pressure through stiffness measurements made using AFMs or nano-indenters and the subsequent application of physical models but also through the development of a nano-pressure probe (in progress).

In addition of the originality of these technological approaches in mecanotransduction, the interest of our R&D teams is to develop and support their evolution directly into the environment of an IBiSA core facility. Thus, the R&D Team PLATIM/RDP is one of the rare facilities in France to provide different and integrated mechanical evaluations for both plant and animal multicellular organisms.

Publications:

  • Bauer, A., Ali, O., Bied, C., Boeuf, S., Bovio, S., Delattre, A., Ingram, G., Golz, J.F. & Landrein, B. Spatiotemporally distinct responses to mechanical forces shape the developing seed of Arabidopsis. (2024) EMBO J. https://doi.org/10.1038/s44318-024-00138-w
  • Creff, A., Ali, O., Bied, C., Bayle, V., Ingram, G. & Landrein, B. Evidence that endosperm turgor pressure both promotes and restricts seed growth and size. (2023) Nature Comm. https://www.nature.com/articles/s41467-022-35542-5

Since 2010, we have developped and implemented numerous methods in optogenetics, and even chemogenetics, in order to have access to dynamics and reversible perturbations of key biological functions such as cell adhesion, cell signaling, transcription factors, inflammation, functions of immune cells and even metabolism. Our lab proposes to share this expertise to the FBI users through access for consulting and even direct collaboration. In the Rhonalpin node, our lab is focused on the coupling between optogenetics, biosensors and metabolism imaging through FLIM imaging. Indeed, we have developed a TIRF microscope presenting a module of FastFLIM imaging. Through the use of dark acceptors, this technology allows the users to extend the possibilities in terms of combining optogenetics, biosensors, metabolic imaging through ratiometric probes and classical multicolors TIRF imaging. Moreover, TIRF imaging allows long term live imaging with low levels of photoxicity. This is essential for metabolic imaging and preserving photon budget for FLIM imaging. In the future, this system will be coupled with a module of evanescent field patterning (EFP) in order to have a specific TIRF-mode illumination of only  a region of interest (microm scale).

Publications

1- An optogenetic approach to control and monitor inflammasome activation. Julien Nadjar, Sylvain Monnier, Estelle Bastien, Anne-Laure Huber, Christiane Oddou, Léa Bardoulet, Gabriel Ichim, Christophe Vanbelle, Bénédicte Py, Olivier Destaing*, Virginie Petrilli*. Recently accepted in Science Signaling. bioRxiv 2023.07.25.550490; doi: https://doi.org/10.1101/2023.07.25.550490

2-Optogenetic control of YAP cellular localisation and function. Toh PJY, Lai JKH, Hermann A, Destaing O, Sheetz MP, Sudol M, Saunders TE. EMBO Rep. 2022 Sep 5;23(9):e54401. 

3-Control of SRC molecular dynamics encodes distinct cytoskeletal responses by specifying its signaling pathway usage. Kerjouan A, Boyault C, Oddou C, Hiriart-Bryant E, Pezet M, Balland M, Faurobert E, Bonnet I, Coute Y, Fourcade B, Albiges-Rizo C, Destaing O. J Cell Sci. 2021 Jan 25;134(2):jcs254599.

4-β1A integrin is a master regulator of invadosome organization and function. Destaing O, Planus E, Bouvard D, Oddou C, Badowski C, Bossy V, Raducanu A, Fourcade B, Albiges-Rizo C, Block MR. Mol Biol Cell. 2010 Dec;21(23):4108-19.

The Liphy R&D team has a long experience in collaboration, joint-development and consulting in optic projects between physics and biology labs. Recently, our team developed a robust method to obtain absolute values of FRET from any epifluorescence microscope. The QuanTI-FRET method calibrates the experimental system and the fluorophore pair, allowing for absolute FRET efficiency and stoichiometry measurements in living cells. Current work focuses on skipping the calibration step with specific samples, hence offering a direct calibration on the sample of interest. This project has been partly funded by the SATT Linksium, an intellectual property has been registered on the software part and discussions are ongoing with private partners.

Another part of the team’s expertise is reflection interference contrast microscopy which allows the measurement of distances with nanometric precision in the vicinity of a reference surface, and to assess the surface functionalization in situ without staining (quantification, quality control). The combination with force application techniques such as flow chambers permits probing biomechanics through the simultaneous control of the force (applied) and the distance (measured). This is essential to study adhesions forces of different organisms: from bacteria to immune cells. The dedicated microscope is fully automated with temperature control, and the PI is currently working on the development of a user-friendly interface for biology-oriented projects. 

Both developments are unique in France.