SFP Alpes

Marco MACCARINI (chercheur UGA)
2026-03-03 14:00 (Europe/Paris) | LMGP – salle des séminaires, Grenoble INP -Phelma 3 parvis Louis Néel, Grenoble, 38054, France
Exploring the Nanostructure of Biomimetic Membranes
Résumé :
Model lipid membranes are simplified yet powerful systems that mimic key features of biological plasma membranes—the essential envelopes that define and protect living cells. Their controlled simplicity makes them ideal for precise experimental techniques, enabling us to explore their interactions with novel nanoengineered materials.
When combined with biological components like proteins, these membranes not only deepen our understanding of fundamental biological processes but also serve as building blocks for advanced nanoengineered materials with tailored technological applications.
In this seminar, I will present examples from my research, where laboratory techniques, large-scale facility analyses, and computational methods converge to provide in-depth characterization and mechanistic insights into membrane behavior. These findings hold significant potential for advancements in health, biotechnology, and fundamental biology.
Short Bio/CV
As a CNRS Chargé de Recherche, I’ve recently joined the LMGP to continue my research journey in this scientific new environment. My academic path has taken me across borders—starting with a Physics degree in Italy, followed by a PhD in Polymer Physics in England, and postdoctoral experiences in Germany and Canada. Along the way, I’ve had the privilege of working at world-class facilities like the Institut Laue Langevin, where I deepened my expertise in large-scale scientific infrastructure. I now continue this work at LMGP, where my research focuses on the intersection of physics, materials science, and biomimetic systems.
Contact : deborah.verger@grenoble-inp.fr

Viviana RICON MONTES & Andreas OFFENHÄUSSER (Forschungszentrum Jülich, Allemagne)
2026-03-05 11:30 - 12:30 | GIN – Amphi Serge Kampf, Grenoble Institut des Neurosciences (GIN) Bât. Edmond J. Safra, Chemin Fortune Ferrini CHU, La Tronche, 38700, France
Devices that interact with the brain: from nanostructured to flexible electrodes
Résumé :
Neural electrodes are the core components of neuroelectronic devices, enabling the recording and simulation of neural activity. Our research focuses on two primary areas : (1) the design and
characterization of the neuron-electrode interface, and (2) the development of flexible neural interfaces for both in vivo and in vitro applications. Microelectrode arrays (MEAs) are commonly used to bridge the interface between neurons and electronic systems. However, current MEAs face limita7ons in signal fidelity, precision of neural modulation, and long-term biocompatibility. To address these challenges, we are developing nanomaterial-based MEAs that offer enhanced physical and chemical properties, leading to improved cell-electrode coupling. Specifically, we have engineered a hybrid structure combining vertical nanostraws with nanocavities, enabling stable, non-invasive, and long-term recording at sub-threshold resolution.
Implantable neural prosthetic devices provide direct access to local neural circuits and are critical components of brain-machine interfaces. While current clinical-grade devices—typically based on silicon or noble metals—have driven significant advances, they oPen fail to sustain reliable neural communication over extended periods. Our goal is to create next-generation neurotechnologies that integrate seamlessly with biological tissue, supporting multimodal neural interrogation through electrical, optical, or chemical means. We are actively exploring novel device architectures, materials, and implantation strategies, alongside rigorous performance evaluation, with the ultimate aim of enabling both acute and chronic in vivo applications. Our approach combines thin-film technology and surface micromachining processes with additive manufacturing techniques, including two-photon lithography. These are integrated with self-
aligned, template-assisted electrodeposition processes, kirigami-inspired designs with matched-die forming, novel bonding methods, and the modular stacking of two-dimensional neural probes with key-lock systems. These technologies support versatile applications, ranging from investigating seizure-like activity in in vitro epilepsy models to advancing visual prosthesis that enable bidirectional communication along the visual pathway.
Contact : clement.hebert@univ-grenoble-alpes.fr

Carlo PIFFERI (Centre de Biophysique Moléculaire, Orléans)
2026-03-06 14:00 - 15:00 | DCM – Salle C209, DCM - Bât Chimie Recherche 301 rue de la Chimie, St Martin d'Hères, 38400, France
Exploiting disulfide-rich peptides as protein epitope mimics : development of a generalizable conjugation approach for immunogen preparation
Résumé :
Generation of specific antibodies against peptides by immunization requires their covalent conjugation to protein carriers to override their inherently weak immunogenicity. The vast majority of bioconjugation approaches to achieve peptide-protein constructs rely on thiol-maleimide chemistry1 and capitalize on a wide array of commercial maleimide-functionalized protein carriers. Disulfide-rich peptides2 (DRPs) possess a rigid, constrained structure that makes them ideal for designing synthetic mimics of protein regions/domains. For bioconjugation purposes, the introduction of a single spare thiol moiety into a linear peptide antigen is straightforward, while DRPs’ disulfide bonds are prone to intramolecular thiophilic attack by the reactive thiolate. This unintended reactivity competes with the desired Michael addition to the maleimide moiety, ultimately disrupting the native disulfide bridging framework. As a result, DRP’s tertiary structure will be altered, affording an immunogen that is a poor mimic of the native target. Although a few studies have explored the late-stage introduction of thiol-containing cross-linkers onto DRP antigens for their conjugation onto protein carriers,3,4 the stability of DRP’s disulfide pattern in the presence of an extra thiol has never been examined. To address this, we systematically evaluated the influence of different spacers in “DRP-spacer-thiol” constructs, under thiol-maleimide reaction conditions.5 Our results highlight how both linker length and flexibility are key to maintain DRP disulfides unaltered, providing a general approach to achieve DRP bioconjugation by thiol-maleimide chemistry. We have applied our approach to a small DRP predicted to closely mimic a surface-accessible epitope of the full LINGO-1 protein, and obtained a very specific antibody response upon immunization: the resulting polyclonal IgG was able to selectively bind the full-length protein in a cellular context, with stringent selectivity across its four homologs.
References :
1. M. Góngora-Benítez, J. Tulla-Puche & F. Albericio, Chem. Rev. 2014, 114, 901–926.
2. K. Renault, J. W. Fredy, P.-Y. Renard & C. Sabot, Bioconjug. Chem. 2018, 29, 2497–2513.
3. H. Katayama & M. Mita, Bioorganic Med. Chem. 2016, 24, 3596–3602.
4. H. Katayama, R. Mizuno & M. Mita, Biosci. Biotechnol. Biochem. 2019, 83, 1791–1799.
5. L. Azzoug et al., ChemRxiv 2025, DOI:10.26434/chemrxiv-2025-krjcm
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Contact : david.goyard@univ-grenoble-alpes.fr

Stéphane GUINDON (LIRMM - Montpellier)
2026-03-12 13:00 - 14:00 | IMAG – Salle de Réunion, 150 place du Torrent, St Martin d’Hères, 38400, France
Recent advances in phylogeography
Contact : lucie.lamothe@univ-grenoble-alpes.fr

Hugues Nury (Irig / IBS)
2026-03-12 18:30 - 22:30 | La Casemate, 2 Place Saint-Laurent, Grenoble, 38000, France
« Soirée du vivant » : récepteurs neuronaux : comment les poisons trouvent leur cible
Cette « S​​oirée du vivant », d’un format inédit, proposera présentation interactive, quiz participatifs, échanges libres, le tout autour de tapas végétales, pour un moment convivial et grand public.
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Hugues Nury, chercheur CNRS à l’Institut de biologie structurale de Grenoble, nous plongera dans l’univers fascinant des venins de serpents, alcaloïdes végétaux et autres insecticides modernes, qui exercent leurs effets en ciblant des récepteurs neuronaux spécifiques. Il apportera d’abord des connaissances générales pour répondre à des questions essentielles telles : pourquoi certaines substances sont-elles mortelles à des doses infimes tandis que d’autres restent inoffensives ? Comment un récepteur neuronal reconnaît-il son « poison » ?​​​​
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​Il présentera ensuite le projet ANR Pesti Penta qu’il coordonne, et qui vise à comprendre les mécanismes moléculaires d’action des insecticides sur les récepteurs neuronaux d’insectes. Cette recherche combine biologie structurale, dynamique moléculaire et électrophysiologie afin d’explorer les interactions entre différentes molécules et leurs cibles biologiques.
À terme, l’objectif de ces travaux fondamentaux est de contribuer au développement d’insecticides plus efficaces et plus ciblés.
En savoir plus : https://www.cea.fr/drf/irig/Pages/Animation-scientifique/seminaires/2026_Nury.aspx

Peter DAHLBERG (Stanford University, USA)
2026-03-13 11:00 - 12:00 | IBS – Salle des séminaires, IBS 71 avenue des Martyrs, Grenoble, 38042, France
Fluorescence-guided cryogenic FIB milling and their application to the study of the NLRP3 inflammasome
Résumé :
Numerous critical events in cell biology depend on rare ( 1 copy per cell) and small (<500 nm in diameter) structures. Observation of these processes at high resolution using cryogenic electron tomography (CryoET) presents challenges, as the structures must first be precisely targeted within thin sections through focused ion beam milling. In this presentation, I will introduce my group’s work on a tri-coincident system that integrates light, ion, and electron microscopy at a single focal point. This approach enables real-time monitoring of the milling process and makes two different modes of guidance possible that require no addition of fluorescent fiducials or image registration and whose accuracy far exceeds the optical diffraction limit. I will discuss both guidance modes in detail and then describe their application to the study of the in situ structure of the NLRP3 inflammasome. Despite its central role in innate immunity as a master regulator responsible for proinflammatory cytokine maturation and cell death, its in situ structure has remained elusive due to challenges in capturing the small singular punctum it forms per cell in thin sections compatible with CryoET — precisely the kind of target the tri-coincident system was developed for. Using our guidance approach, our cryo-tomograms revealed that the NLRP3 inflammasome forms a dense condensate within and around the microtubule-organizing center. At a later stage after activation, we saw further growth of the condensate, and the cells underwent pyroptosis with widespread mitochondrial damage and autophagy. Our study revealed new insights into NLRP3 structure and other organelle alterations during inflammation.
Contact : ibs.seminaires@ibs.fr

Martha MERROW (LMU Munich, Germany)
2026-03-16 11:00 - 12:00 | LiPhy, Salle de Conférence, 140 rue de la Physique, St Martin d'Hères, 38400
A circadian clock in Bacillus subtilis
Résumé :
The circadian clock is a molecular machine that is present in each one of our cells, directing diverse processes in a cell(developmentally)-specific manner. The natural state of the clock is ‘entrainment’, namely through synchronization with zeitgeber signals (such as the light/dark cycle) in the environment. Once moved to constant conditions, a free running rhythm of approximately 24h can be observed, demonstrating the endogenous nature of the clock. One can understand how the clock relates to our lives by noting the timing of the sleep wake cycle: this is determined by the interaction of the biological (circadian) oscillator and the external zeitgeber cycle. Disrupting the clock in humans and mice leads to increased cancers, metabolic disease and decreased cognitive performance, likely through misexpression of key regulators. The circadian clock is an essential aspect of biology and its function can be regarded as a biophysical phenomenon.
Circadian clocks have been described in all kingdoms of life except for the Eubacteria – until very recently. I will discuss the circadian clock in the model prokaryote, Bacillus subtilis. We observe rhythms in gene expression, in colony morphology on agar, and in metabolism and in planktonic cultures. The circadian transcriptome shows pervasive regulation of gene expression by the biological clock, even more extensively than sigma factors. The clock is thus a major regulatory phenomenon in this bacterium. Our work begs the questions ‘what is the same as clocks in higher organisms?’ and ‘what is different?’.
Contact : irina.mihalcescu@univ-grenoble-alpes.fr

Montserrat SOLER-LÓPEZ (Macromolecular X-ray Crystallography, Imaging and Scattering Group, ESRF)
2026-03-17 14:00 - 15:00 | LMGP – salle des séminaires, Grenoble INP -Phelma 3 parvis Louis Néel, Grenoble, 38054, France
Mitochondrial Bioenergetics in Alzheimer’s Disease : Insights from the European Synchrotron
Résumé :

Alzheimer’s disease (AD) is a devastating neurodegenerative disorder increasingly linked to defects in mitochondrial bioenergetics. At the European Synchrotron Radiation Facility (ESRF), we investigate the structural and functional mechanisms that underlie mitochondrial dysfunction in AD, with a focus on respiratory complex I, a central player in cellular energy production [1,2].
Using an integrative biology approach, we combine macromolecular crystallography, cryo-electron microscopy, X-ray imaging, and spectroscopy to analyse the architecture and regulation of mitochondrial complex I and its assembly factors (MCIA proteins) across spatial and temporal scales. Our structural and functional studies reveal novel regulatory mechanisms of energy metabolism, including phosphorylation-dependent modulation at the interface of respiration and fatty acid oxidation. Importantly, we demonstrate that AD-related amyloid oligomers disrupt these regulatory processes within neuronal mitochondria, thereby contributing to oxidative stress and impaired bioenergetics in AD [3,4]. Recent synchrotron-based imaging, including X-ray fluorescence and nano-tomography, has further provided first insights into the ultrastructure of mitochondrial assemblies in situ.
Collectively, these findings highlight how the ESRF’s interdisciplinary, state-of-the-art methodologies enable breakthroughs in deciphering the molecular basis of neurodegeneration, offering new perspectives for diagnostic markers and therapeutic strategies targeting mitochondrial dysfunction in Alzheimer’s disease.
[1] Giachin et al. Dynamics of Human Mitochondrial Complex I Assembly: Implications for Neurodegenerative Diseases. Front. Mol. Biosci. 2016, 3:43
[2] McGregor & Soler-Lopez. Structural basis of bioenergetic protein complexes in Alzheimer’s disease pathogenesis. Cur Opin Struct Biol. 2023, 80:102573
[3] Giachin et al. Assembly of The Mitochondrial Complex I Assembly Complex Suggests a Regulatory Role for Deflavination. Angew. Chem. Int. Ed. 2021, 60(9):4689
[4] McGregor et al. The assembly of the Mitochondrial Complex I Assembly complex uncovers a redox pathway coordination. Nat Commun. 2023, 14(1):8248
Contact : deborah.verger@grenoble-inp.fr

Matthieu RAYNAL (Sorbonne Université, CNRS, Institut Parisien de Chimie Moléculaire (IPCM))
2026-03-19 14:00 - 15:00 | DCM – Salle C209, DCM - Bât Chimie Recherche 301 rue de la Chimie, St Martin d'Hères, 38400, France
Supramolecular helical catalysts : chirality induction and beyond
Résumé :
Helices are commonly formed by symmetry breaking operating during the bottom-up assembly of small molecules or monomers and their sense of rotation can be controlled by various methods. Important progress has been made in controlling the chiral and structural properties of supramolecular discrete assemblies and polymers.[1] Benzene-1,3,5- tricarboxamide[2] (BTA) are ubiquitous synthons for the preparation of hydrogen-bonded helices but it remains to be demonstrated how a given macroscopic property, notably related to chirality (e.g. chiroptical, magnetic, catalytic), can be affected by tuning the structure of these supramolecular polymers or copolymers. We demonstrated that the supramolecular chirality of BTA assemblies can be transferred to intrinsically achiral metal centres (Rh, Cu) located at their periphery.[3] How the selectivity of a catalytic reaction of reference can be affected by the nature of the monomers, the presence of metal centres, and the addition of achiral additives will be particularly discussed.[4] Not only a fine tuning of the chirality of the supramolecular assemblies but also a proper control of their dynamicity is key to address important challenges. We recently disclose the possibility to select one major (70%-79%) amongst four possible stereoisomers of an amino alcohol by applying the supramolecular helical catalyst in either concomitant (with no inversion of catalyst handedness) or sequential (with inversion of catalyst handedness) hydrosilylation and hydroamination reactions [5].
References :
[1] Yashima E. et al. Chem. Rev., 2016, 116, 13752.
[2] Cantekin S. et al. Chem. Soc. Rev., 2012, 41, 6125.
[3] Desmarchelier A. et al. J. Am. Chem. Soc., 2016, 138, 4908.
[4] (a) Li Y. et al. J. Am. Chem Soc., 2020, 142, 5676. (b) Martínez-Aguirre M. A. et al. Angew. Chem. Int. Ed., 2021, 60, 4183. (c) Hammoud A. et al. Chem. Eur. J., 2023, e202300189. (d) Kong H. et al. ChemistryEurope, 2023, 1, e202300027.
[5] Chen, R. et al. Nature Commun., 2024, 15, 4116
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Contact : adrien.quintard@univ-grenoble-alpes.fr

Chrystel GENOUD (EPFL, Lausane, Suisse)
2026-03-20 11:00 - 12:00 | IBS – Salle des séminaires, IBS 71 avenue des Martyrs, Grenoble, 38042, France
Understanding tissue by volumeEM – some examples from an EM platform
Séminaire dans le cadre de la Journée Microscopie Electronique
Résumé :
Understanding the complex architecture of cells and tissues requires imaging technologies that can bridge the gap between ultrastructural details and large-volume context in room temperature and cryo-EM. Volume electron microscopy (volume EM) addresses this need by enabling 3D imaging of biological samples at nanometer resolution over tens to hundreds of microns. In this presentation, I will provide an overview of volume EM techniques available on our platform based on examples and how we combine it with correlative light and electron microscopy.I will also show how we are adressing the targeting of small structures in lare tissue in cryo-ET by using the serial lift-out method and cryo-CLEM. The example of targeting the Casparian strip in the root of Arabidopsis thaliana will be developed.
Contact : ibs.seminaires@ibs

Chloé ROFFAY (IMP Vienna, Austria)
2026-03-23 11:00 - 12:00 | LiPhy – Salle de conférence, LiPhy 140 avenue de la Physique, St Martin d'Hères, 38402, France
Uncovering the forces driving the fate and shape of the extraembryonic amnion during human gastrulation
Résumé :
Extraembryonic tissues provide key molecular signals and mechanical support to the growing embryo. For instance, the extraembryonic amnion, which forms a fluid-filled sac surrounding the embryo, was recently shown to trigger germ layer specification during gastrulation, by secreting BMP ligands. Despite the key roles of extraembryonic tissues in embryo development, little is still known regarding their molecular and biophysical programs, particularly in human. Using a 2D stem cell-based model of human gastrulation, termed gastruloid discs, we found that amnion cells undergo a sharp columnar-to-squamous transition concomitantly with fate specification. Via biophysical modelling, direct force measurements, pharmacological and genetic perturbations, we showed that this morphogenetic transition is amnion-intrinsic and it is driven by active wetting, i.e. a transition from tensile to adhesion-dominated cellular states. Molecularly, active wetting is implemented via a rewiring of cytoskeleton composition, from actomyosin to keratin-based cytoskeletal networks, akin to a bistable toggle-switch in gene regulatory networks. Strikingly, blocking shape changes at the colony edge results both in defective cellular states in the amnion and impaired gastruloid disc morphogenesis within the embryonic compartment. Together, our findings establish that a cytoskeletal toggle switch couples fate specification to tissue architecture in the human amnion and suggest an unexpectedly active mechanical role for extraembryonic tissues in shaping the embryo proper.
Contact : thomas.boudou@univ-grenoble-alpes.fr

Martial MARBOUTY (Institut Pasteur – Paris)
2026-03-26 13:00 - 14:00 | IMAG – Salle de Réunion, 150 place du Torrent, St Martin d’Hères, 38400, France
Phages with a broad host range are common across ecosystems
Contact : lucie.lamothe@univ-grenoble-alpes.fr

Soutenance de Thèse de Mohammad CHORFA (IBS/Groupe Synchrotron)
2026-03-30 09:00 - 11:00 | IBS – Salle des séminaires, IBS 71 avenue des Martyrs, Grenoble, 38042, France
Effets de la dynamique structurale d’une famille de protéines fluorescentes infrarouges sur leurs propriétés de fluorescence
Résumé :
Ce travail de thèse consiste en une étude structurale approfondie d’une famille de protéines fluorescentes infrarouges (IFP) développées à partir du bactérophytochrome d’une bactérie Gram-négative du genre Bradyrhizobium, constituée de la protéine mIFP et de ses variants décalés vers le bleu iBlueberry et iBlueberry2. Les IFP présentent un fort intérêt en imagerie de corps entier en raison de l’existence d’une fenêtre optique des tissus entre 650 et 900 nm, au-dessus du domaine de longueur d’onde dans lequel l’hémoglobine et la déoxi-hémoglobine absorbent, et en-dessous du domaine dans lequel l’eau et les lipides absorbent et diffusent la lumière. Les protéines étudiées ici présentent un pic d’émission de fluorescence entre 660 et 720 nm.
Le bactériophytochrome et les IFP qui en sont dérivées utilisent la biliverdine, un produit du catabolisme des hèmes, comme chromophore afin d’absorber la lumière entre 640 et 690 nm. L’étude structurale a permis de montrer qu’une boucle localisée au voisinage de la biliverdine pouvait aborder un grand nombre de conformations, à la différence des autres phytochromes et IFP étudiés jusqu’à présent, où cette boucle ne semble posséder qu’une seule conformation. La conséquence de cette fluctuation conformationnelle est la présence d’une configuration du chromophore jamais encore observée menant à une conformation compacte du macrocycle formé par les quatre cycles pyrroles de la biliverdine, distincte de la conformation linéaire, ou étendue, habituellement observée. Les spectroscopies d’absorption UV-Visible et d’émissions de fluorescence in crystallo, c’est-à-dire directement appliquées aux cristaux, ont permis de montrer que la conformation compacte du chromophore menait à un pic d’émission de fluorescence au-delà de 760 nm pour iBlueberry et iBlueberry 2, et de 800 nm pour mIFP. Cette conformation semble être favorisé par l’empilement cristallin, et être seulement très faiblement peuplée en solution.
L’analyse des séquences de bactériophytochromes et d’IFP a permis de mettre en évidence la conformation particulière du coude beta au début de la boucle en question. L’ingénierie de ce coude beta chez un membre d’une autre famille de protéines fluorescentes a montré qu’elle permettait effectivement d’augmenter la plasticité de la boucle.
Ce travail donne des pistes pour modifier la configuration du chromophore au sein de la protéine par ingénierie rationnelle, notamment en utilisant des méthodes basées sur l’intelligence artificielle, et ainsi permettre d’obtenir de nouvelles IFPs avec des maxima d’émission en plein milieu de la fenêtre optique des tissus, afin de mieux utiliser celle-ci dans des expériences de marquage à plusieurs couleurs en imagerie tissulaire ou de corps entier.
Contact :ibs.seminaires@ibs.fr

Soutenance de Thèse de Espérance AHO (IBS/Groupe Structure et Activité des Glycosaminoglycanes)
2026-03-31 14:00 - 16:00 | IBS – Salle des séminaires, IBS 71 avenue des Martyrs, Grenoble, 38042, France
Structural and Functional effect of CXCL12/Heparan Sulfate Interactions at the Cell Surface
Résumé :
The glycocalyx is a protective layer covering the surface of cells, particularly endothelial cells, and represents a major regulator of cell-environment interactions. It functions as a mechanical barrier, a mechanosensor, and a signalling platform that controls vascular permeability. In inflammatory and tumor contexts, alterations in glycocalyx structure and density promote increased cell adhesion, extravasation, and metastatic dissemination. Structurally, the glycocalyx is composed of glycolipids, glycoproteins and proteoglycans bearing glycosaminoglycan (GAG) chains, including heparan sulfate (HS). These linear polysaccharides, organized into sulfated and non-sulfated domains, interact with numerous proteins, including growth factors and chemokines, thereby modulating their bioavailability and biological activity. Notably, chemokine-HS interactions are essential for the formation of chemotactic gradients involved in leukocyte recruitment, inflammatory extravasation, and tumor progression. The chemokine CXCL12 (stromal cell-derived factor-1, SDF-1), a member of the CXC chemokine family, exists as six distinct isoforms generated by alternative splicing of the CXCL12 gene. These isoforms share a common N-terminal sequence but differ in their C-terminal extensions, which influence their interactions with HS. Among them, CXCL12γ isoform, characterized by its exceptionally high affinity for HS, represent a particularly relevant candidate.
This work builds upon previous findings from our group showing, using biophysical approaches (QCM-D, FRAP), that CXCL12 is able to induce cross-linking of HS chains on biomimetic surfaces, resulting in HS rigidification, decreased layer thickness, and reduced HS lateral mobility. These observations suggest that chemokine-HS interactions can modify the physical properties of HS beyond a simple ligand-presentation role. The central hypothesis of this project is that binding of the CXCL12γ to HS induces remodelling of the endothelial glycocalyx at the cell surface thereby changing cellular mechanical properties and promoting immune cell adhesion. Here, we investigate the impact of CXCL12γ on HS organization across molecular, nanoscale, and cellular levels by combining biomimetic surfaces, biophysical approaches, super-resolution microscopy, and cell-based assays.
We show that CXCL12γ reorganizes HS chains at the endothelial cell surface and that all HS-binding sites are required for efficient HS rigidification and network reorganization. CXCL12γ-driven remodeling of the glycocalyx reduces HS thickness and alters its nanoscale topology, thereby promoting paracellular permeability and formation of adhesive platforms that facilitate leukocyte capture, and firm adhesion.
Contact : ibs.seminaires@ibs

Karine PHILIPPOT (Laboratoire de Chimie de Coordination du CNRS (LCC-CNRS), Toulouse, France)
2026-04-02 10:30 - 11:30 | DCM – Salle C209, DCM - Bât Chimie Recherche 301 rue de la Chimie, St Martin d'Hères, 38400, France
Design of nanocatalysts following molecular chemistry principles
Résumé :
Due to their singular properties and potential applications in various fields, considerable effort is being devoted to the design of metal-based nanomaterials. The « Metal Nanoparticle Engineering » team at LCC-CNRS (Toulouse, France) has developed an effective toolkit for the synthesis of controlled metal nanoparticles using concepts from molecular chemistry. This approach is based on the hydrogenation of organometallic or metallo-organic complexes under mild conditions (ambient temperature; 3 bar H2) in the presence of ligands as stabilising agents. (1) This approach makes it possible to obtain small nanoparticles (<10 nm) with controlled composition, either monometallic or bimetallic (alloy, core-shell, surface-decorated). These nanoparticles can be deposited on a support by simple impregnation or by direct synthesis in the presence of the chosen support (polymers, ionic liquids, silica, alumina, carbonaceous materials, etc.). These metal nanoparticle systems are suitable models for fundamental research. They find applications in various fields such as catalysis. (2,3) Non exhaustive examples concern biomass valorization (4), hydrogenation catalysis (4-6) including reduction of CO2, (7) or electrocatalytic (8-11) or photocatalytic (12-13) water splitting process.
References :
1 C. Amiens, D. Ciuculescu-Pradines, K. Philippot, Coord. Chem. Rev., 2016, 38, 409-432.
2 M. R. Axet, K. Philippot, Chem. Rev 2020, Chem. Rev. 2020, 120, 2, 1085-1145.
3 Nanoparticles in Catalysis: Advances in Synthesis and Applications, Wiley-VCH, K. Philippot & A. Roucoux (Eds.), 2021.
4 M. Cardona, P. Lecante, C. Dinoi, I. del Rosal, R. Poteau, K. Philippot, M. Rosa Axet, Green Chemistry, 2021, 23, 8480-8500.
5 C. J Abou-Fayssal, C. Fliedel, R. Poli, A. Riisager, K. Philippot, E. Manoury, Materials Today Chemistry, 2023, 34, 101752 (https://doi.org/10.1016/j.mtchem.2023.101752).
6 D. Krishnan, L. Schill, M. R. Axet, K. Philippot, A. Riisager, ChemCatChem 2024,16(4) : e20230144.
7 X.-P. Fu, L. Peres, J. Esvan, C. Amiens, K. Philippot, N. Yan, Nanoscale, 2021, 13, 8931-8939.
8 J. Creus, S. Drouet, S. Suriñach, P. Lecante, V. Collière, R. Poteau, K. Philippot, J.García-Antón, X. Sala, ACS Catalysis., 2018, 8, 11094-11102.
9 L. Mallón, J. Navarro-Ruiz, C. Cerezo-Navarrete, N. Romero, I. del Rosal, J. García-Antón, R. Bofill, L. M. Martínez-Prieto, K. Philippot, R. Poteau, X. Sala, ACS Applied Materials &
Interfaces 2025, 17(4), 6198-6210.
10 Nanoscale NiCu electrocatalyst for the hydrogen evolution reaction, T. Straistari, N. Romero, J. Esvan, M. Gil Sepulcre, C. Amiens, O. Rüdiger, S. Debeer, S. Cavaliere, K. Philippot, Nanoscale 2025, 17, 17592-17603.
11 Regulating NiFeOOH oxidation states through ruthenium incorporation, L. Mallón,1, L. Peres, N. Rivas, A. Garzón Manjón, C. Scheu, M. Gil-Sepulcre, O. Rüdiger, S. DeBeer, N. Romero, J.
Esvan, J. García-Antón, L. Rodríguez-Santiago, X. Solans-Monfort, R. Bofill, K. Philippot, L. Francàs, X. Sala, J. Mater. Chem. A, 2026, in press.
12 N. Romero, F. Sabuzi, M. Forchetta, M. Natali, R. Signorini, R. Bofill, L. Francàs, M. Gil-Sepulcre, O. Rüdiger, S. DeBeer, J. García-Antón, K. Philippot, P. Galloni, A. Sartorel, X. Sala, Green Chemistry 2025, 27, 4352-4368.
13 Dyadic Ru-based Nanomaterials for Visible Light-driven Photocatalytic Hydrogen Evolution, G. Martí, M. Aliqué, I. López, L. Francàs, R. Bofill, O. Schott, G. S. Hanan, N. Romero, K. Philippot, A. Llobet, M. Natali, J. García-Antón, X. Sala, Applied Surface Science, 2026, 716, 164621
Contact : carole.duboc@univ-grenoble-alpes.fr

Soutenance de Thèse de Alix HAUREZ / DCM (équipe CIRe)
2026-04-02 13:30 - 15:30 | DCM – Salle C209, DCM - Bât Chimie Recherche 301 rue de la Chimie, St Martin d'Hères, 38400, France
Electroréduction du CO2 en méthane par des nanoparticules de cuivre générées in-situ

Résumé : A venir

Contact : Nathalie.Camerino@univ-grenoble-alpes.fr

Carole ESCARTIN (directrice de recherche à NeuroPSI, CNRS, Université Paris-Saclay)
2026-04-02 16:00 - 18:30 | Laboratoire IJCLab – Auditorium Pierre Lehmann, Rue Ampère, Orsay cedex, 91898, France
Les cellules gliales dans les maladies neurodégénératives : rôles émergents et potentiel thérapeutique
Résumé :
Les neurones ne sont pas seuls dans le cerveau. A leur côté, plusieurs types de cellules, collectivement appelées « cellules gliales », remplissent de nombreux rôles essentiels pour le bon fonctionnement et la survie des neurones. Ces cellules leur apportent des substrats énergétiques, assurent la défense contre des pathogènes, éliminent certains déchets cellulaires, et même régulent la façon dont les neurones transmettent et traitent l’information nerveuse.
Au final, les cellules gliales qui restent souvent dans l’ombre des neurones, sont des partenaires actifs permettant au cerveau de fonctionner, mais aussi d’apprendre et de s’adapter.
Depuis plusieurs années, les chercheurs découvrent que ces cellules jouent aussi un rôle important dans de nombreuses maladies qui touchent le cerveau. En effet, ces cellules se transforment en contexte pathologique, elles sont dites « réactives ». Ces changements peuvent avoir des conséquences majeures – positives ou négatives – sur les neurones et leur survie.
Les cellules gliales sont l’objet d’études variées pour comprendre leurs rôles dans le cerveau sain et pathologique, ouvrant des nouvelles pistes thérapeutiques pour de nombreuses maladies cérébrales.
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Toutes les informations sont disponibles sur : https://indico.ijclab.in2p3.fr/event/12390/
Contact : louis.fayard@IJCLAB.INP3.FR

Juan FONTECILLA-CAMPS (IBS/Groupe Métalloprotéines)
2026-04-03 11:00 - 12:00 | IBS – Salle des séminaires, IBS 71 avenue des Martyrs, Grenoble, 38042, France
Origin and evolution of the eukaryotic cell : the emergence of cooperation, competition and altruisme
Résumé :

The evolutionary transition from prokaryotes to eukaryotes most likely involved the fusion of an archeon with a bacterium. One important consequence of this fusion was an increase in mean gene length in protists to about 1500 nucleotides, and corresponding 500 amino acids-long proteins. The subsequent evolution of plants and metazoans resulted in a lengthening of their genes (to over 10,000 nucleotides per gene in vertebrates). However, the coded proteins remained at an average length of also about 500 amino acids. The significance of the difference in gene length but constant protein size has been the subject of some controversy.
A second result of the evolutionary transition from prokaryotes to eukaryotes was the emergence of competition, cooperation and even altruism, between cells. These interactions cover a large spectrum going from single-cell organisms to mammals like us. Indeed, recent studies have shown that cancer cells do collaborate during tumor growth.​

These two subjects will be discussed during the seminar.​​​

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Les séminaires et soutenances sont ouverts à tous, notez toutefois que l’accès au campus EPN nécessite un avis de rendez-vous. Merci de remplir ce formulaire et de l’adresser, plus de 48h à l’avance, à ce contact. Pensez à vous munir d’une pièce d’identité le jour de votre visite.

Soutenance de Thèse de Eymeline PAGEOT (IRIG / IBS)
2026-04-21 14:00 - 16:00 | IBS – Salle des séminaires, IBS 71 avenue des Martyrs, Grenoble, 38042, France
Decoding chaos : a cryo-em walk through physarum polycephalum heterogeneous cell extracts
Résumé :

Cryo-electron microscopy (cryo-EM) has become a central method in structural biology for determining high-resolution structures of macromolecular assemblies. However, most cryo-EM studies still rely on highly purified samples, which limits the range of biological systems that can be investigated. In recent years, the analysis of cell extracts by single particle cryo-EM has emerged as an alternative strategy to explore the structural diversity of cellular proteins directly from complex mixtures. Despite its potential, this approach remains technically challenging due to the high level of heterogeneity present in such samples and the difficulty of identifying proteins without complementary techniques such as mass spectrometry.

​ The work presented in this thesis investigates the feasibility of using cryo-EM as a primary discovery tool to determine and identify protein structures directly from fractionated cell extracts. The study focuses on the plasmodial slime mould Physarum polycephalum, a non-model eukaryotic organism whose structural proteome is largely unexplored. In contrast to most previous studies in the field, protein identification relied solely on structural information derived from cryo-EM reconstructions.

Cell extracts from P. polycephalum were fractionated using biochemical separation methods and analysed by cryo-EM. Because such samples contain a wide range of proteins with different sizes, shapes, and abundances, dedicated image processing strategies were developed to address the challenges posed by particle heterogeneity and flexibility. Particular attention was given to 2D classification, particle sorting, and iterative particle picking strategies to improve the recovery of multiple particle orientations and increase the number of particles contributing to 3D reconstructions.

Using these approaches, fourteen macromolecular assemblies were identified and solved directly from the heterogeneous samples. In cases where the cryo-EM maps reached sufficient resolution, atomic models could be built ab initio. For lower-resolution structures, identification relied on structural comparison with known protein folds and structures predicted by generative tools. This work demonstrates that protein identity and putative function can be inferred directly from the structural information, opening the possibility of structure-based genome annotation in poorly characterised organisms.

Beyond the individual structures determined in this study, this work also outlines the methodological challenges associated with large-scale structural exploration of complex biological mixtures. The largely manual nature of several steps in the workflow currently limits the throughput of the approach. Strategies to automate key stages of the pipeline, including particle classification, initial model generation, and structural identification, are therefore discussed as important directions for future development.​

Finally, this work highlights the importance of community-driven analysis and open data sharing for the continued development of large-scale structural exploration approaches. Making both the raw cryo-EM data and the solved structures publicly available enables other researchers to further investigate the dataset, potentially identifying additional structures and improving the analysis using new computational methods, as well as enabling the development of the methods themselves. In the longer term, combining such « shotgun » cryo-EM approaches with advances in computational modelling and high-throughput data analysis may contribute to the systematic structural characterisation of cellular proteomes.

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Les séminaires et soutenances sont ouverts à tous, notez toutefois que l’accès au campus EPN nécessite un avis de rendez-vous. Merci de remplir ce formulaire et de l’adresser, plus de 48h à l’avance, à ce contact. Pensez à vous munir d’une pièce d’identité le jour de votre visite.

Anamaria NESCULEA (LBBE - Lyon)
2026-04-23 13:00 - 14:00 | IMAG – Salle de Réunion, 150 place du Torrent, St Martin d’Hères, 38400, France
Genomic correlates of convergent phenotypic evolution in birds
Contact : lucie.lamothe@univ-grenoble-alpes.fr

Soutenance de Thèse de Moritz KIRCHNER (IRIG / IBS)
2026-04-23 14:00 - 16:00 | IBS – Salle des séminaires, IBS 71 avenue des Martyrs, Grenoble, 38042, France
Molecular bases of a multiprotein assembly linking membrane biology to stress adaptation in enterobacteria
Résumé :

Enteric bacteria encounter a variety of stress factors when infecting their host. This includes but is not limited to acid stress, oxygen limitation and antibiotic stress. Bacteria counteract such stressors using various stress response systems. A central factor in the stress adaptation of enterobacteria is their cell envelope, in particular their cell membrane. A system of proteins which has been demonstrated to be involved in multiple stress adaptation pathways is the RavA-ViaA-LdcI triad in Escherichia coli. RavA and ViaA are two proteins with as of yet unknown function that have been shown to sensitise E. coli to aminoglycoside antibiotics under anaerobic conditions. RavA forms a large complex with LdcI, an inducible lysine decarboxylase which is one of the central enzymes involved in acid stress response of E. coli. Both RavA and ViaA have been shown to bind specific anionic lipids and their lipid binding capacity is strongly linked to their sensitising effect to aminoglycosides.
​This thesis presents the exploration of the connections these three proteins have to each other and their other binding partners by optical and electron microscopy in order to elucidate how their action leads to antibiotic sensitisation and what role their connection to the cell membrane and acid stress might play in this regard. It is shown that LdcI prefers to localise to the cell periphery to efficiently counteract acid stress and that mutations of its active site lead to large domain movements which might play a crucial role in its enzymatic activity. Furthermore, an investigation of liposome decoration by RavA and ViaA is presented, demonstrating the effect they have on membrane shape. In addition, the first cryo-EM structure of ViaA is presented using helical repeat proteins to stabilise the protein. Finally, predictions of RavA and ViaA protein-protein interactions in the inner E. coli membrane reveal possible functional targets of the proteins and the implications of these new possible avenues for action are discussed with regard of the microscopy investigations.

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Les séminaires et soutenances sont ouverts à tous, notez toutefois que l’accès au campus EPN nécessite un avis de rendez-vous. Merci de remplir ce formulaire et de l’adresser, plus de 48h à l’avance, à ce contact. Pensez à vous munir d’une pièce d’identité le jour de votre visite.

Mikhail ELTSOV (Institut de Génétique et de Biologie Moléculaire et Cellulaire, Illkirch)
2026-04-24 11:00 - 12:00 | IBS – Salle des séminaires, IBS 71 avenue des Martyrs, Grenoble, 38042, France
Seeing chromatin in situ : advances and challenges of human and machine vision
Résumé :
Using cryo-electron tomography of vitreous sections, we directly visualized nucleosomes and linker DNA trajectories in situ within flash frozen Drosophila embryos. Measurements of linker length and curvature revealed an irregular zigzag pattern of chromatin folding characterized by relatively limited linker bending. In favorable orientations, individual nucleosome particles and their structural variants could be identified without the need for structural averaging. Moreover, we detected particles containing a variable number of DNA gyres, ranging from fewer than one to up to three, resembling previously proposed non-octameric nucleosome-like particles.
To place these structural observations in the context of functional chromatin organization, we are developing computational approaches for nucleosome identification in cellular tomograms. We believe that our approach, Template Learning, based on training deep-learning networks on synthetic tomographic data, can provide a general framework for detecting small macromolecular complexes in crowded cellular environments.
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Hôte : Irina Gutsche (IBS/MICA)

Giulio FACCHINI (Laboratoire Matière et Systèmes Complexes, Paris)
2026-05-04 11:00 - 12:00 | LiPhy – Salle de conférence, LiPhy 140 avenue de la Physique, St Martin d'Hères, 38402, France
Deciphering the origin of saddle-shape geometry in the microstructure of echinoderms skeleton
Résumé :
The microstructure of echinoderms skeleton, like sea stars and sea urchins, is an impressive example of self-organization and complexity. This structure called stereom is a porous meshwork, made of calcite, whose surface is saddle-shaped, and remind of minimal surfaces. Minimal surfaces have intrigued scientists for centuries, as they can spontaneously emerge from minimizing interfacial energy like surface tension. Several studies have addressed the morphogenesis of the stereom, in sea urchins and other echinoderms, showing that it forms via the addition of tiny mineral bids at the tip of small skeletal elements that successively branch and bridge to form a complex network. Yet, a global, mechanistic, comprehension of how biomineralizing cells control preferential deposition is still lacking.
During the seminar I will present a recent work1 on the morphogenesis of the particular stereom geometry observed in the sea star P. nodosus. Here, the stereom can take the form of a diamond Triply Periodic Minimal Surface (TPMS) which confer it specific mechanical properties. Using different marking protocols, we provide the first experimental insight in the formation of the diamond TPMS stereom, and show that the formation of such a highly ordered structure relies on a precise and timely coordination of the branching and bridging episodes. Moreover, we provide experimental evidences of an organic precursor made of F – actin fibers exhibiting saddle-shape geometry. We hypothesise that such a fibers template may self-organise under mechanical tension, thus explaining the peculiar curvature signature of the final structure. Finally, I will present some ongoing experimental work performed on sea urchins, showing that the same morphogenetic mechanism could be shared across very different species.
Contact : emmanuel.siefert@univ-grenoble-alpes.fr

Tiffany HO (Lab of Prof Brian Wilson at the Princess Margaret Cancer Center, Toronto, Canada)
2026-05-06 11:00 - 12:00 | IAB – Salle de séminaire, IAB Site Santé - Allée des Alpes, La Tronche, 38700, France
Redefining photodynamic therapy beyond local : Nanoparticle-enabled photodynamic-immune stimulation for treatment of hot and cold cancers
Résumé :
Photodynamic therapy (PDT) is a cancer-treatment modality that, under the appropriate treatment parameters, can induce immunogenic tumor cell death and stimulate anti-tumor immunity (photodynamic immune stimulation, PDIS). This has the potential to prime adaptive immune responses capable of targeting distant, untreated lesions, as well as eradicating primary treated tumor. The clinical impact of PDT has been limited by conventional photosensitizers, which often exhibit poor tumor selectivity and insufficient immune activation. Nanomedicine-based photosensitizer platforms offer a promising strategy to overcome such limitations. Porphysomes (PS), a class of all-organic, multifunctional porphyrin-lipid nanoparticles currently in Phase I clinical trials for positron emission tomography (PET) imaging of metastatic gynecological cancers, represent one such platform.
This seminar will focus on our work investigating PS-PDIS to drive systemic anti-tumor immunity across tumor models of different immunogenicity, including immunologically “hot” colorectal (CT26) tumors and “cold” melanoma (B16F10) and ovarian (ID8) tumors. The findings establish a strategy to expand PDT beyond localized tumor ablation toward systemic disease control, including prevention of recurrence and metastasis in cold tumors typically resistant to conventional immunotherapies. The seminar will also highlight ongoing efforts to develop gold nanocluster-based platforms for both light- and radiation-mediated immune stimulation in pancreatic cancer, further expanding the scope of nanomaterial-enabled photodynamic and radiodynamic immune stimulation.
This work was supported by the Terry Fox Research Institute (PPG 1137) and the Government of Canada’s New Frontiers in Research Fund (NFRF) (#NFRFT-2020-00573). »
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Contact : anne-laure.bulin@univ-grenoble-alpes.fr

Adeline LACROIX (Centre for Addiction and Mental Health, Toronto, Canada)
2026-05-06 11:30 - 12:30 | GIN – Amphi Serge Kampf, Grenoble Institut des Neurosciences (GIN) Bât. Edmond J. Safra, Chemin Fortune Ferrini CHU, La Tronche, 38700, France
Towards an Understanding of Sex Differences in Socio-Emotional Processing in Autism
Résumé :
Autism is characterized by persistent difficulties in social interaction and social cognition. These difficulties are partly related to atypical processing of socio-emotional signals, including emotional facial expressions. Although core autistic characteristics are observed in both males and females, increasing evidence suggests that autistic females often show a more subtle socio-emotional profile, marked by greater attention to social stimuli and more typical-appearing social behavior. However, this profile remains insufficiently characterized, and the underlying neurobiological mechanisms are still poorly understood.

Given the central role of face processing in social cognition, we conducted a series of behavioral and EEG studies to investigate sex differences in autism during face processing at different stages of attentional processing. Our results reveal sex-related differences in autism from early stages of face processing, with autistic females showing an intermediate profile between autistic males and non-autistic females. Together, these findings indicate that aggregating males and females may obscure meaningful neurocognitive differences in socio-emotional processing and highlight the need for sex-informed experimental designs and theoretical frameworks in autism research. They further suggest that early differences in socio-emotional processing may contribute to the subtler phenotypic presentation of autism in females.
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Contact : michael.pereira@univ-grenoble-alpes.fr

Pierre GARCIA (LCB, Marseille)
2026-05-07 13:00 - 14:00 | IMAG – Salle de Réunion, 150 place du Torrent, St Martin d’Hères, 38400, France
When life plays LEGOs : Ancient evolution and extreme diversity of homologous oxidoreductases involved in energy production
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Contact : lucie.lamothe@univ-grenoble-alpes.fr

Amaury PATIN (Expert in Organic Chemistry, Nestlé Institute of Food Safety & Analytical Sciences (NIFSAS), Lausanne, Suisse)
2026-05-07 14:00 - 15:00 | DCM – Salle C209, DCM - Bât Chimie Recherche 301 rue de la Chimie, St Martin d'Hères, 38400, France
The Journey of an Organic Chemist : What Organic Chemistry trains you for— From Drug Discovery toFood (Safety)
Résumé :
Organic chemistry plays a central but often under-recognized role in addressing complex industrial challenges that extend well beyond molecule synthesis. In this seminar, I will describe how training in organic chemistry can be leveraged across multiple industrial domains, based on my career spanning academia, biotech, and industrial research within a multinational food company.
The talk presents a personal career journey illustrating the diversity of opportunities available to organic chemists. Starting from doctoral and postdoctoral research in organic chemistry, I moved into medicinal chemistry within a biotech startup before joining Nestlé Research, where organic chemistry became a central tool for addressing challenges in ingredient innovation and food safety.
Through selected case studies, I will show how the same fundamental chemical concepts — reactivity, molecular structure, metabolism — can be applied in very different contexts, from drug discovery to food safety. The seminar will also address the evolution from hands-on scientist to project manager and group leader, highlighting the importance of soft skills such as communication, interdisciplinarity, and leadership.
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Contact : sandrine.py@univ-grenoble-alpes.fr

Chloé GRAZON (Laboratoire de Chimie des Polymères Organiques (LCPO), Université de Bordeaux / CNRS / Bordeaux INP, Pessac)
2026-05-21 10:00 - 11:00 | DCM – Salle C209, DCM - Bât Chimie Recherche 301 rue de la Chimie, St Martin d'Hères, 38400, France
Luminescent nanoparticles as bright nanotools for biosensing & bioimaging
Résumé : à venir
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Contact : galina.dubacheva@univ-grenoble-alpes.fr

Soutenance de Thèse de Furhan ABDUL-REZAK (DCM (équipe I2BM) - IAB)
2026-05-21 13:30 - 16:30 | IAB – Salle de séminaire, IAB Site Santé - Allée des Alpes, La Tronche, 38700, France
Selective Conjugation of Gold Nanoclusters with Macromolecules: From Functionalization to Assembly
Résumé : à venir
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Contact : nathalie.camerino@univ-grenoble-alpes.fr

Mark GLOVER (Department of Biochemistry, University of Alberta, Edmonton, Canada)
2026-05-26 11:00 - 12:00 | IBS – Salle des séminaires, IBS 71 avenue des Martyrs, Grenoble, 38042, France
Mechanism of sRNA recognition and regulation by FinO RNA chaperones
Résumé :
The FinO family of RNA chaperones regulate sRNA function throughout gram negative bacteria. Many of the best characterized family members bind to rho-independent transcription termination structures at the 3’ ends of sRNAs and mediate pairing of the sRNA with their mRNA targets. The crystal structure of the FinO domain of the Legionella pneumophila chaperone RocC bound to its sRNA target reveals a novel interaction that recognizes both the stem and the 3’ end of the terminator structure. The structure suggests a mechanism by which different FinO proteins can selectively bind RNAs with different 3’ tail lengths, which is likely conserved throughout the FinO family. Biochemical and in vivo studies indicate that intrinsically disordered regions adjacent to the FinO domain are also essential for sRNA regulation, by remodeling RNA structure to facilitate RNA-RNA association.
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Hôte : Dr Nicolas Coquelle (IBS/Groupe Dynamique et Cinétique des processus moléculaires)
Rappel : L’accès au campus EPN nécessite un avis de rendez-vous. A cet effet merci d’adresser votre demande à ibs.seminaires@ibs.fr (au moins 48h à l’avance).
