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1. SMAC mimetic drives microglia phenotype and glioblastoma immune microenvironment

Author

Snacel-Fazy, Emmanuel, Soubéran, Aurélie, Grange, Magali, Joseph, Kevin, Colin, Carole, Morando, Philippe, Luche, Hervé, Pagano, Alessandra, Brustlein, Sophie, Debarbieux, Franck, Toutain, Soline, Siret, Carole, van de Pavert, Serge A., Rougon, Geneviève, Figarella-Branger, Dominique, Ravi, Vidhya Madapusi, Tabouret, Emeline, and Tchoghandjian, Aurélie

Published
2024
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3. Functional networks of inhibitory neurons orchestrate synchrony in the hippocampus.

Author

Bocchio, Marco, Vorobyev, Artem, Sadeh, Sadra, Brustlein, Sophie, Dard, Robin, Reichinnek, Susanne, Emiliani, Valentina, Baude, Agnes, Clopath, Claudia, and Cossart, Rosa

Subjects
PYRAMIDAL neurons, DIVISION of labor, SYNCHRONIC order, NEURONS, OPTOGENETICS, INTERNEURONS
Abstract

Inhibitory interneurons are pivotal components of cortical circuits. Beyond providing inhibition, they have been proposed to coordinate the firing of excitatory neurons within cell assemblies. While the roles of specific interneuron subtypes have been extensively studied, their influence on pyramidal cell synchrony in vivo remains elusive. Employing an all-optical approach in mice, we simultaneously recorded hippocampal interneurons and pyramidal cells and probed the network influence of individual interneurons using optogenetics. We demonstrate that CA1 interneurons form a functionally interconnected network that promotes synchrony through disinhibition during awake immobility, while preserving endogenous cell assemblies. Our network model underscores the importance of both cell assemblies and dense, unspecific interneuron connectivity in explaining our experimental findings, suggesting that interneurons may operate not only via division of labor but also through concerted activity. Interneurons control the timing of activation of excitatory neurons, but how single interneurons affect synchrony in vivo is unclear. This study shows that CA1 hippocampus interneurons form a functionally connected network that promotes synchrony between pyramidal cells at the single neuron level. [ABSTRACT FROM AUTHOR]

Published
2024
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4. Comparing Different Methods for the Diagnosis of Liver Steatosis: What Are the Best Diagnostic Tools?

Author

Chopinet, Sophie, Lopez, Olivier, Brustlein, Sophie, Uzel, Antoine, Moyon, Anais, Varlet, Isabelle, Balasse, Laure, Kober, Frank, Bobot, Mickaël, Bernard, Monique, Haffner, Aurélie, Sdika, Michaël, Montcel, Bruno, Guillet, Benjamin, Vidal, Vincent, Grégoire, Emilie, Hardwigsen, Jean, and Brige, Pauline

Subjects
STAINS & staining (Microscopy), NUCLEAR magnetic resonance spectroscopy, NEAR infrared spectroscopy, RECEIVER operating characteristic curves, LIVER transplantation
Abstract

Background: Due to the ongoing organ shortage, marginal grafts with steatosis are more frequently used in liver transplantation, leading to higher occurrences of graft dysfunction. A histological analysis is the gold standard for the quantification of liver steatosis (LS), but has its drawbacks: it is an invasive method that varies from one pathologist to another and is not available in every hospital at the time of organ procurement. This study aimed to compare non-invasive diagnostic tools to a histological analysis for the quantification of liver steatosis. Methods: Male C57BL6J mice were fed with a methioninecholine-deficient (MCD) diet for 14 days or 28 days to induce LS, and were compared to a control group of animals fed with a normal diet. The following non-invasive techniques were performed and compared to the histological quantification of liver steatosis: magnetic resonance spectroscopy (MRS), CARS microscopy, 99mTc MIBI SPECT imaging, and a new near-infrared spectrometer (NIR-SG1). Results: After 28 days on the MCD diet, an evaluation of LS showed ≥30% macrovesicular steatosis. High correlations were found between the NIR-SG1 and the blinded pathologist analysis (R2 = 0.945) (p = 0.001), and between the CARS microscopy (R2 = 0.801 (p < 0.001); MRS, R2 = 0.898 (p < 0.001)) and the blinded pathologist analysis. The ROC curve analysis showed that the area under the curve (AUC) was 1 for both the NIR-SG1 and MRS (p = 0.021 and p < 0.001, respectively), while the AUC = 0.910 for the Oil Red O stain (p < 0.001) and the AUC = 0.865 for the CARS microscopy (p < 0.001). The AUC for the 99mTc MIBI SPECT was 0.640 (p = 0.013), and this was a less discriminating technique for LS quantification. Conclusions: The best-performing non-invasive methods for LS quantification are MRS, CARS microscopy, and the NIR-SG1. The NIR-SG1 is particularly appropriate for clinical practice and needs to be validated by clinical studies on liver grafts. [ABSTRACT FROM AUTHOR]

Published
2024
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5. SMAC mimetics drive microglia phenotype and glioblastoma immune microenvironment

Author

Snacel-Fazy, Emmanuel, primary, Soubéran, Aurélie, additional, Grange, Magali, additional, Joseph, Kevin, additional, Colin, Carole, additional, Morando, Philippe, additional, Luche, Hervé, additional, Brustlein, Sophie, additional, Debarbieux, Franck, additional, Siret, Carole, additional, de Pavert, Serge A. van, additional, Rougon, Geneviève, additional, Figarella-Branger, Dominique, additional, Ravi, Vidhya Madapusi, additional, Tabouret, Emeline, additional, and Tchoghandjian, Aurélie, additional

Published
2024
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7. Melanoma-inhibitor of apoptosis protein: a key driver of microglia phenotype and glioblastoma immune microenvironment

Author

Snacel-Fazy, Emmanuel, primary, Soubéran, Aurélie, additional, Grange, Magali, additional, Joseph, Kevin, additional, Colin, Carole, additional, Morando, Philippe, additional, Luche, Hervé, additional, Brustlein, Sophie, additional, Debarbieux, Franck, additional, Siret, Carole, additional, de Pavert, Serge A. van, additional, Rougon, Geneviève, additional, Figarella-Branger, Dominique, additional, Ravi, Vidhya Madapusi, additional, Tabouret, Emeline, additional, and Tchoghandjian, Aurélie, additional

Published
2024
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10. Light-inducible T cell engagers trigger, tune, and shape the activation of primary T cells

Author

Jaeger, Morgane, primary, Anastasio, Amandine, additional, Chamy, Léa, additional, Brustlein, Sophie, additional, Vincentelli, Renaud, additional, Durbesson, Fabien, additional, Gigan, Julien, additional, Thépaut, Morgane, additional, Char, Rémy, additional, Boussand, Maud, additional, Lechelon, Mathias, additional, Argüello, Rafael J., additional, Marguet, Didier, additional, He, Hai-Tao, additional, and Lasserre, Rémi, additional

Published
2023
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14. Light-inducible T cell engagers trigger, tune and shape the activation of primary T cells

Author

Jaeger, Morgane, primary, Anastasio, Amandine, additional, Brustlein, Sophie, additional, Vincentelli, Renaud, additional, Durbesson, Fabien, additional, Char, Rémy, additional, Boussand, Maud, additional, Lechelon, Mathias, additional, Argüello, Rafael J., additional, Marguet, Didier, additional, He, Hai-Tao, additional, and Lasserre, Rémi, additional

Published
2022
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15. Light affects the magnetotactic behaviour and reproduction of ellipsoidal multicellular magnetoglobules in the Mediterranean Sea

Author

Qian, Xin-Xin, ZHAO, Yi-Cong, Santini, Claire-lise, Pan, Hong Miao, Xiao, Tian, Chen, Hai Tao, Song, Tao, Li, Jin Hua, Alberto, François, Brustlein, Sophie, Wu, Long-Fei, Institute of Microbiology, Chinese Academy of Sciences, International Associated Laboratory of Evolution and Development of Magnetotactic Multicellular Organisms ( LIA-MagMC), Chinese Academy of Sciences [Beijing] (CAS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de chimie bactérienne (LCB), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), Institute of Electrical Engineering, Chinese Academy of Sciences, Beijing 100190, China, Key Laboratory of Earth and Planetary Physics, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing, 100029, China., and Aix Marseille Université (AMU)

Subjects
[SDV]Life Sciences [q-bio], magnetic alignment, equipment and supplies, human activities, coordinated swimming, Photo-response
Abstract

International audience; Magnetotactic bacteria (MTB) synthesize intracellular magnetic organelles, magnetosomes, which consist of magnetic crystals that are enveloped in a membrane. Magnetosomes are organized into a chain(s) and confer on cells a magnetic dipolar moment. This magnetic property allows MTB cells to align and swim along geomagnetic field lines, a movement referred to as magnetotaxis. Some MTB species change their swim direction in response to illumination by UV, violet and blue light. Here we analyzed the polarity of morphology, magnetism and motion in Mediterranean multicellular magnetotactic prokaryotes, also called, magnetoglobules or MMP. The magnetoglobules were assembled from 60-80 cells into an asymmetric ellipsoidal morphology with a relative narrow and large end. They swam dominantly northward, parallel to the direction of the magnetic field, with the narrow-end as the leading side. In response to a reversal in thedirection of the magnetic field they aligned quickly along the magnetic field lines and kept swimming northward. Interestingly, under constant illumination,385 nm UV light, magnetoglobules changed their swimming direction southward anti-parallel to the direction of the magnetic field, with the large-end as the leading side. The change from a northward to southward direction, occurred along with an increase of swimming speed. A minimum of 35 mW/cm2 irradiance of UV light was sufficient to trigger the swimming re-orientation. UV radiation also triggered the unidirectional division of magnetoglobules. Together these results revealed a coordination of the polarity of magnetoglobule morphology, magnetic moment and swimming orientation, in response to magnetic and optical stimuli. The UV triggered the reversal of magnetotaxis and magnetoglobule division indicating the ecological significance of light for multicellular magnetotactic prokaryotes

Published
2021

17. Functional Mapping of Adhesiveness on Live Cells Reveals How Guidance Phenotypes Can Emerge From Complex Spatiotemporal Integrin Regulation

Author

Robert, Philippe, primary, Biarnes-Pelicot, Martine, additional, Garcia-Seyda, Nicolas, additional, Hatoum, Petra, additional, Touchard, Dominique, additional, Brustlein, Sophie, additional, Nicolas, Philippe, additional, Malissen, Bernard, additional, Valignat, Marie-Pierre, additional, and Theodoly, Olivier, additional

Published
2021
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18. Longitudinal Intravital Microscopy Reveals Axon Degeneration Concomitant With Inflammatory Cell Infiltration in an LPC Model of Demyelination

Author

El Waly, Bilal, Buttigieg, Emeline, Karakus, Cem, Brustlein, Sophie, Debarbieux, Franck, Institut de Neurosciences de la Timone (INT), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), Centre Européen de Recherche en Imagerie médicale (CERIMED), Aix Marseille Université (AMU)-Assistance Publique - Hôpitaux de Marseille (APHM)-École Centrale de Marseille (ECM)-Institut Paoli-Calmettes, Fédération nationale des Centres de lutte contre le Cancer (FNCLCC)-Fédération nationale des Centres de lutte contre le Cancer (FNCLCC)-Centre National de la Recherche Scientifique (CNRS), Department of Physiology, and Center for Integrative Physiology and Molecular Medicine, Saarland University [Saarbrücken], Institut de Biologie du Développement de Marseille (IBDM), Aix Marseille Université (AMU)-Collège de France (CdF (institution))-Centre National de la Recherche Scientifique (CNRS), ANR-15-CE16-0009,NeuroInflamDyn,Etude de la dynamique et de la fonction de la neuroinflammation dans un modèle EAE combinant l'imagerie biphotonique et la cytométrie multiparamètrique ,(2015), and ANR-15-CE19-0018,MyDeepCARS,Microscopie en profondeur de fluorescence et de Diffusion Raman Anti-Stokes Stimulée polarisée pour l'imagerie quantitative de la démyélination dans les pathologies neurodégénératives(2015)

Subjects
lysophosphatidylcholine, Cellular and Molecular Neuroscience, spinal glass window, [SDV]Life Sciences [q-bio], neurodegeneration innate immune cells, CARS, demyelination
Abstract

International audience; Demyelination and axon degeneration are major events in all neurodegenerative diseases, including multiple sclerosis. Intoxication of oligodendrocytes with lysophosphatidylcholine (LPC) is often used as a selective model of focal and reversible demyelination thought to have no incidence for neurons. To characterize the cascade of cellular events involved in LPC-induced demyelination, we have combined intravital coherent antistoke Raman scattering microscopy with intravital two-photon fluorescence microscopy in multicolor transgenic reporter mice. Moreover, taking advantage of a unique technique of spinal glass window implantation, we here provide the first longitudinal description of cell dynamics in the same volume of interest over weeks after insults. We have detected several patterns of axon–myelin interactions and classified them in early and advanced events. Unexpectedly, we have found that oligodendrocyte damages are followed by axon degeneration within 2 days after LPC incubation, and this degeneration is amplified after the recruitment of the peripheral proinflammatory cells at day 4. Beyond day 7, the recovery of axon number and myelin takes 3 more weeks postlesion and involves a new wave of anti-inflammatory innate immune cells at day 14. Therefore, recurrent imaging over several weeks suggests an important role of peripheral immune cells in regulating both the axonal and oligodendroglial fates and thereby the remyelination status. Better understanding the recruitment of peripheral immune cells during demyelinating events should help to improve diagnosis and therapy.

Published
2020

20. ALOHA—Astronomical Light Optical Hybrid Analysis

Author

Lehmann, Lucien, Darré, Pascaline, Szemendera, Ludovic, Gomes, Jean-Thomas, Baudoin, Romain, Ceus, Damien, Brustlein, Sophie, Delage, Laurent, Grossard, Ludovic, Reynaud, François, Photonique Fibre et Sources Cohérentes (XLIM-PHOT), XLIM (XLIM), and Université de Limoges (UNILIM)-Centre National de la Recherche Scientifique (CNRS)-Université de Limoges (UNILIM)-Centre National de la Recherche Scientifique (CNRS)

Subjects
[SPI.OPTI]Engineering Sciences [physics]/Optics / Photonic
Abstract

International audience; This paper gives an overview of the Astronomical Light Optical Hybrid Analysis (ALOHA) project dedicated to investigate a new method for high resolution imaging in mid infrared astronomy. This proposal aims to use a non-linear frequency conversion process to shift the thermal infrared radiation to a shorter wavelength domain compatible with proven technology such as guided optics and detectors. After a description of the principle, we summarise the evolution of our study from the high flux seminal experiments to the latest results in the photon counting regime.

Published
2018

21. Phosphoinositides regulate the TCR/CD3 complex membrane dynamics and activation

Author

Chouaki-Benmansour, Nassima, Ruminski, Kilian, Sartre, Anne-Marie, Phelipot, Marie-Claire, Salles, Audrey, Bergot, Elise, Wu, Ambroise, Chicanne, Gaëtan, Fallet, Mathieu, Brustlein, Sophie, Billaudeau, Cyrille, Formisano, Anthony, Mailfert, Sébastien, Payrastre, Bernard, Marguet, Didier, Brasselet, Sophie, He, Hai-Tao, and Hamon, Yannick

Abstract

Phosphoinositides (PIs) play important roles in numerous membrane-based cellular activities. However, their involvement in the mechanism of T cell receptor (TCR) signal transduction across the plasma membrane (PM) is poorly defined. Here, we investigate their role, and in particular that of phosphatidylinositol 4,5-bisphosphate [PI(4,5)P2] in TCR PM dynamics and activity in a mouse T-cell hybridoma upon ectopic expression of a PM-localized inositol polyphosphate-5-phosphatase (Inp54p). We observed that dephosphorylation of PI(4,5)P2 by the phosphatase increased the TCR/CD3 complex PM lateral mobility prior stimulation. The constitutive and antigen-elicited CD3 phosphorylation as well as the antigen-stimulated early signaling pathways were all found to be significantly augmented in cells expressing the phosphatase. Using state-of-the-art biophotonic approaches, we further showed that PI(4,5)P2 dephosphorylation strongly promoted the CD3e cytoplasmic domain unbinding from the PM inner leaflet in living cells, thus resulting in an increased CD3 availability for interactions with Lck kinase. This could significantly account for the observed effects of PI(4,5)P2 dephosphorylation on the CD3 phosphorylation. Our data thus suggest that PIs play a key role in the regulation of the TCR/CD3 complex dynamics and activation at the PM.

Published
2018

22. Phosphoinositides regulate the TCR/CD3 complex membrane dynamics and activation

Author

Chouaki-Benmansour, Nassima, Ruminski, Kilian, Sartre, Anne-Marie, Phelipot, Marie-Claire, Salles, Audrey, Bergot, Elise, Wu, Ambroise, Chicanne, Gaëtan, Fallet, Mathieu, Brustlein, Sophie, Billaudeau, Cyrille, Formisano, Anthony, Mailfert, Sébastien, Payrastre, Bernard, Marguet, Didier, Brasselet, Sophie, Hamon, Yannick, He, Hai-Tao, Centre d'Immunologie de Marseille - Luminy (CIML), Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU), Institut des Maladies Métaboliques et Cardiovasculaires (I2MC), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut National de la Santé et de la Recherche Médicale (INSERM), Institut FRESNEL (FRESNEL), Centre National de la Recherche Scientifique (CNRS)-École Centrale de Marseille (ECM)-Aix Marseille Université (AMU), Laboratoire de photonique et de nanostructures (LPN), Centre National de la Recherche Scientifique (CNRS), Centre de Physiopathologie Toulouse Purpan (CPTP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Sol Agro et hydrosystème Spatialisation (SAS), AGROCAMPUS OUEST, Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut National de la Recherche Agronomique (INRA), This work was supported by institutional grants from INSERM and CNRS and by specific grants from the Agence Nationale de la Recherche (ANR-10-BLAN-1509, ANR-11-LABX-Investissement d’Avenir Labex-INFORM, ANR-10-INBS-04-01 France Bio Imaging, ANR-10-BLAN-1509,ReceptOrient,Observation de l'activation du récepteur des lymphocytes T (TCR) en temps réel: suivi des orientations dynamiques du domaine intracellulaire du complexe récepteur dans les cellules vivantes par imagerie en fluorescence polarisée résolue de temps(2010), ANR-10-INBS-0004,France-BioImaging,Développment d'une infrastructure française distribuée coordonnée(2010), Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS), Centre de Physiopathologie Toulouse Purpan ex IFR 30 et IFR 150 (CPTP), Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS), Institut National de la Recherche Agronomique (INRA)-AGROCAMPUS OUEST, ANR-10-INBS-04-01/10-INBS-0004,France-BioImaging,Développment d'une infrastructure française distribuée coordonnée(2010), Aix Marseille Université (AMU)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Brasselet, Sophie, BLANC - Observation de l'activation du récepteur des lymphocytes T (TCR) en temps réel: suivi des orientations dynamiques du domaine intracellulaire du complexe récepteur dans les cellules vivantes par imagerie en fluorescence polarisée résolue de temps - - ReceptOrient2010 - ANR-10-BLAN-1509 - BLANC - VALID, Développment d'une infrastructure française distribuée coordonnée - - France-BioImaging2010 - ANR-10-INBS-0004 - INBS - VALID, Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National de la Santé et de la Recherche Médicale (INSERM), and Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Hybridomas, [SPI.OPTI] Engineering Sciences [physics]/Optics / Photonic, CD3 Complex, T-Lymphocytes, lcsh:R, Cell Membrane, Receptors, Antigen, T-Cell, lcsh:Medicine, Phosphatidylinositols, Article, Phosphoric Monoester Hydrolases, Fungal Proteins, Jurkat Cells, Mice, [SPI.OPTI]Engineering Sciences [physics]/Optics / Photonic, Animals, Humans, lcsh:Q, Phosphorylation, lcsh:Science, Author Correction
Abstract

International audience; Phosphoinositides (PIs) play important roles in numerous membrane-based cellular activities. However, their involvement in the mechanism of T cell receptor (TCR) signal transduction across the plasma membrane (PM) is poorly defined. Here, we investigate their role, and in particular that of phosphatidylinositol 4,5-bisphosphate [PI(4,5)P2] in TCR PM dynamics and activity in a mouse T-cell hybridoma upon ectopic expression of a PM-localized inositol polyphosphate-5-phosphatase (Inp54p). We observed that dephosphorylation of PI(4,5)P2 by the phosphatase increased the TCR/CD3 complex PM lateral mobility prior stimulation. The constitutive and antigen-elicited CD3 phosphorylation as well as the antigen-stimulated early signaling pathways were all found to be significantly augmented in cells expressing the phosphatase. Using state-of-the-art biophotonic approaches, we further showed that PI(4,5)P2 dephosphorylation strongly promoted the CD3ε cytoplasmic domain unbinding from the PM inner leaflet in living cells, thus resulting in an increased CD3 availability for interactions with Lck kinase. This could significantly account for the observed effects of PI(4,5)P2 dephosphorylation on the CD3 phosphorylation. Our data thus suggest that PIs play a key role in the regulation of the TCR/CD3 complex dynamics and activation at the PM.

Published
2017

26. Parametric amplification of weak images - Application to fluorescence lifetime imaging

Author

Brustlein, Sophie, Centre d'Immunologie de Marseille - Luminy (CIML), Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU), Université de Franche-Comté, Fabrice Devaux(fabrice.devaux@univ-fcomte.fr), Brustlein, Sophie, and Aix Marseille Université (AMU)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)

Subjects
photon statistics, [SPI.OPTI] Engineering Sciences [physics]/Optics / Photonic, optique quantique, Nonlinear optic, quantum optic, optical parametric amplification, spontaneous parametric down-conversion, lifetime, temps de vie, Optique non linéaire, amplification paramétrique optique, [PHYS.QPHY]Physics [physics]/Quantum Physics [quant-ph], [SPI.OPTI]Engineering Sciences [physics]/Optics / Photonic, fluorescence paramétrique, fluorescence, statistique de photons, [PHYS.QPHY] Physics [physics]/Quantum Physics [quant-ph]
Abstract

This thesis dealt with an application of the ultra-fast optical temporal gating properties of parametric image amplification to fluorescence lifetime imaging. We have proposed a method which associates each pixel of an image to a lifetime without scanning the sample. The objective of this work was to resolve different lifetimes on the same image in the nano to picosecond time scale. The first part shown that a weak image of dye fluorescence can be retrieved with a good signal to noise ratio, despite of the presence of noise in amplified images due to the amplification of quantum noise (Spontaneous Parametric Down Conversion). We have also shown that this noise (SPDC) can be used to achieve 2D radiance map directly expressed in photons per spatio temporal mode. Radiance images of incoherent signals with 10-2 photon per mode have been resolved. The second part of this work was devoted to fluorescence lifetime imaging. We use here parametric interaction in picosecond pulsed regime to perform a temporal sampling of the fluorescence signal. In this case, the optical temporal gate is achieved by detecting only the idler wave. Indeed, only the part of the signal synchronized with the pump pulse is amplified and duplicated on the idler channel. Hence, the detection of the idler wave and the rejection of the signal allow gating of the signal with a time gate duration given by the pump pulse duration (down to 1 ps). Images of different lifetimes have been obtained on the picosecond time scale with liquid and solid samples (dye molecules in PMMA). Moreover, we have observed very weak variations of the lifetime (few ps) according to the chemical environment of the fluorophore., Cette thèse porte sur une application des propriétés de porte optique temporelle de l'amplification paramétrique à l'imagerie de temps de vie de fluorescence. Nous proposons une méthode qui permet d'associer à chaque pixel d'une image un temps de déclin sans scanner l'échantillon. L'objectif étant de résoudre sur la même image différents temps de vie dans une gamme allant de la nano à la picoseconde. Dans un premier temps, nous avons montré qu'il était possible de détecter des images de fluorescence de faible niveau amplifiées, avec un bon rapport signal à bruit malgré la présence de bruit dans les images liée à l'amplification du bruit quantique (SPDC). Nous avons également montré que ce bruit permettait d'obtenir une cartographie de la luminance d'une source incohérente directement exprimée en nombre de photons par mode spatio-temporel. La deuxième partie de ces travaux visait l'application à l'imagerie de temps de vie de fluorescence. Nous utilisons ici l'interaction paramétrique en régime impulsionnel pour échantillonner un signal de fluorescence dans le temps. La fonction de porte optique temporelle est dans ce cas assurée par la détection de l'onde idler seule qui est, d'un point de vue temporel, la réplique de la partie du signal synchrone avec la pompe. La résolution temporelle est alors fixée par la durée de l'impulsion pompe (jusqu'à 1 ps). Des images d'échantillons liquides ou solides (fluorophores et PMMA) sont obtenues avec des temps de vie de quelques dizaines de picosecondes. De plus, nous avons montré qu'il était possible de détecter de très faibles variations (de quelques ps) du temps de déclin d'un même fluorophore suivant son environnement chimique.

Published
2005

27. How Sum Frequency Generation Can be Used for High Resolution Imaging

Author

Ceus, Damien, Brustlein, Sophie, Del Rio, L., Tonello, Alessandro, Reynaud, François, PHOTONIQUE, XLIM (XLIM), Université de Limoges (UNILIM)-Centre National de la Recherche Scientifique (CNRS)-Université de Limoges (UNILIM)-Centre National de la Recherche Scientifique (CNRS), Institut FRESNEL (FRESNEL), Centre National de la Recherche Scientifique (CNRS)-École Centrale de Marseille (ECM)-Aix Marseille Université (AMU), Maury, Véronique, and Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)

Subjects
[SPI.OPTI] Engineering Sciences [physics]/Optics / Photonic, Astrophysics::Instrumentation and Methods for Astrophysics, [SPI.OPTI]Engineering Sciences [physics]/Optics / Photonic
Abstract

International audience; We propose a new version of high angular resolution instrument taking advantage of the frequency conversion of astronomical light by SFG.

Published
2010

28. Influence of birefringence on polarization resolved nonlinear microscopy and collagen SHG structural imaging

Author

Aït-Belkacem, Dora, Gasecka, Alicja, Munhoz, Fabiana, Brustlein, Sophie, Brasselet, Sophie, Institut FRESNEL (FRESNEL), Centre National de la Recherche Scientifique (CNRS)-École Centrale de Marseille (ECM)-Aix Marseille Université (AMU), MOSAIC (MOSAIC), Centre National de la Recherche Scientifique (CNRS)-École Centrale de Marseille (ECM)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-École Centrale de Marseille (ECM)-Aix Marseille Université (AMU), Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS), Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS), and Munhoz, Fabiana

Subjects
[PHYS.PHYS.PHYS-OPTICS] Physics [physics]/Physics [physics]/Optics [physics.optics], [PHYS.PHYS.PHYS-OPTICS]Physics [physics]/Physics [physics]/Optics [physics.optics], [SPI.OPTI] Engineering Sciences [physics]/Optics / Photonic, [SPI.OPTI]Engineering Sciences [physics]/Optics / Photonic, ComputingMilieux_MISCELLANEOUS
Abstract

International audience

Published
2010

29. Utilisation de la conversion paramétrique en somme de fréquence dans un interféromètre d'imagerie haute résolution pour astronomie

Author

Reynaud, François, Brustlein, Sophie, del Rio, Louis, Tonello, Alessandro, Delage, Laurent, Ceus, Damien, Grossard, Ludovic, PHOTONIQUE, XLIM (XLIM), Université de Limoges (UNILIM)-Centre National de la Recherche Scientifique (CNRS)-Université de Limoges (UNILIM)-Centre National de la Recherche Scientifique (CNRS), Institut FRESNEL (FRESNEL), Centre National de la Recherche Scientifique (CNRS)-École Centrale de Marseille (ECM)-Aix Marseille Université (AMU), Lebraud, Sophie, and Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)

Subjects
[SPI.OPTI] Engineering Sciences [physics]/Optics / Photonic, [SPI.OPTI]Engineering Sciences [physics]/Optics / Photonic, ComputingMilieux_MISCELLANEOUS
Abstract

International audience

Published
2009

30. Raman depolarization ratio of liquids probed by linear polarization coherent anti-Stokes Raman spectroscopy

Author

Munhoz, Fabiana, Brustlein, Sophie, Gachet, David, Billard, Franck, Brasselet, Sophie, Rigneault, Hervé, Institut FRESNEL (FRESNEL), Centre National de la Recherche Scientifique (CNRS)-École Centrale de Marseille (ECM)-Aix Marseille Université (AMU), and Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)

Subjects
polarization, spectroscopy, [PHYS.PHYS.PHYS-OPTICS]Physics [physics]/Physics [physics]/Optics [physics.optics], microscopy, CARS
Abstract

International audience; We present a simple analytical model to describe the linear polarization coherent anti-Stokes Raman scattering (CARS) spectroscopy. In this scheme, the pump and Stokes beams can have arbitrary linear polarization states and the CARS emitted signal is analyzed along two perpendicular directions. We concentrate on isotropic media without electronic resonances and show that only two polarization CARS measurements performed at the peak and the dip of a CARS spectrum are sufficient to deduce the Raman depolarization ratio, the resonant versus nonresonant contribution, the Raman resonance frequency and the linewidth.We demonstrate the applicability of our scheme to toluene and cyclohexane solutions.

Published
2009

31. Imagerie optique haute résolution pour l'astronomie.Développement technologique et méthodes prospectives

Author

Reynaud, François, Delage, Laurent, Tonello, Alessandro, Oliver, S., del Rio, Louis, Brustlein, Sophie, PHOTONIQUE, XLIM (XLIM), Université de Limoges (UNILIM)-Centre National de la Recherche Scientifique (CNRS)-Université de Limoges (UNILIM)-Centre National de la Recherche Scientifique (CNRS), and Maury, Véronique

Subjects
ComputingMilieux_MISCELLANEOUS
Abstract

National audience

Published
2008

33. Temporal hypertélescope ; Up conversion and coherence transfer for high resolution imaging

Author

Reynaud, François, Delage, Laurent, Tonello, Alessandro, Olivier, Serge, del Rio, Louis, Brustlein, Sophie, PHOTONIQUE, XLIM (XLIM), Université de Limoges (UNILIM)-Centre National de la Recherche Scientifique (CNRS)-Université de Limoges (UNILIM)-Centre National de la Recherche Scientifique (CNRS), and Maury, Véronique

Subjects
ComputingMilieux_MISCELLANEOUS
Abstract

International audience

Published
2006

49. Leukocyte transmigration efficiency and longitudinal forward-thrusting force in a microfluidic Transwell device

Author

Aoun, Laurene, Nègre, Paulin, Gonsales, Cristina, Seveau de Noray, Valentine, Brustlein, Sophie, Biarnes-Pelicot, Martine, Valignat, Marie-Pierre, and Theodoly, Olivier

Abstract

Transmigration of leukocytes across blood vessels walls is a critical step of the immune response. Transwell assays examine transmigration properties in vitro by counting cells passages through a membrane, however the difficulty of in situ imaging hampers a clear disentanglement of the roles of adhesion, chemokinesis and chemotaxis. We used here microfluidic Transwells to image the cells transition from 2D migration on a surface to 3D migration in a confining microchannels, and measure cells longitudinal forward-thrusting force in microchannels. Primary human effector T lymphocytes adhering with integrins LFA-1 (αLβ2) had a marked propensity to transmigrate in transwells without chemotactic cue. Both adhesion and contractility were important to overcome the critical step of nucleus penetration, but were remarkably dispensable for 3D migration in smooth microchannels deprived of topographic features. Transmigration in smooth channels was qualitatively consistent with a propulsion by treadmilling of cell envelope and squeezing of cell trailing edge. Stalling conditions of 3D migration were then assessed by imposing pressure drops across microchannels. Without specific adhesion, the cells slid backwards with sub-nanonewton forces, showing that 3D migration under stress is strongly limited by a lack of adhesion and friction with channels. With specific LFA-1 mediated adhesion, stalling occurred at around 3 and 6 nN in respectively 2x4 and 4x4 μm2channels, supporting that stalling of adherent cells was under pressure control rather than force control. The stall pressure of 4 mbar is consistent with the pressure of actin filament polymerization that mediates lamellipod growth. The arrest of adherent cells under stress seems therefore controlled by the compression of the cell leading edge that perturbs cells front-rear polarization, and triggers adhesion failure or polarization reversal. While stalling assays in microfluidic Transwells do not mimic in vivo transmigration, they provide a powerful tool to scrutinize 2D/3D migration, barotaxis and chemotaxis.

Published
2021
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50. Longitudinal Intravital Microscopy Reveals Axon Degeneration Concomitant With Inflammatory Cell Infiltration in an LPC Model of Demyelination.

Author

El Waly B, Buttigieg E, Karakus C, Brustlein S, and Debarbieux F

Abstract

Demyelination and axon degeneration are major events in all neurodegenerative diseases, including multiple sclerosis. Intoxication of oligodendrocytes with lysophosphatidylcholine (LPC) is often used as a selective model of focal and reversible demyelination thought to have no incidence for neurons. To characterize the cascade of cellular events involved in LPC-induced demyelination, we have combined intravital coherent antistoke Raman scattering microscopy with intravital two-photon fluorescence microscopy in multicolor transgenic reporter mice. Moreover, taking advantage of a unique technique of spinal glass window implantation, we here provide the first longitudinal description of cell dynamics in the same volume of interest over weeks after insults. We have detected several patterns of axon-myelin interactions and classified them in early and advanced events. Unexpectedly, we have found that oligodendrocyte damages are followed by axon degeneration within 2 days after LPC incubation, and this degeneration is amplified after the recruitment of the peripheral proinflammatory cells at day 4. Beyond day 7, the recovery of axon number and myelin takes 3 more weeks postlesion and involves a new wave of anti-inflammatory innate immune cells at day 14. Therefore, recurrent imaging over several weeks suggests an important role of peripheral immune cells in regulating both the axonal and oligodendroglial fates and thereby the remyelination status. Better understanding the recruitment of peripheral immune cells during demyelinating events should help to improve diagnosis and therapy., (Copyright © 2020 El Waly, Buttigieg, Karakus, Brustlein and Debarbieux.)

Published
2020
Full Text
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