A5081900461- Neuroscience and Neuropharmacology Research
- Cellular transport and secretion
- Alzheimer's disease research and treatments
- MicroRNA in disease regulation
- RNA regulation and disease
- Neurogenesis and neuroplasticity mechanisms
- Lipid Membrane Structure and Behavior
- Diabetes and associated disorders
- S100 Proteins and Annexins
- Neuroinflammation and Neurodegeneration Mechanisms
- Pancreatic function and diabetes
- Retinal Development and Disorders
- Photoreceptor and optogenetics research
- Advanced Fluorescence Microscopy Techniques
- Wnt/β-catenin signaling in development and cancer
- Photochromic and Fluorescence Chemistry
- Cell Image Analysis Techniques
- Protein Degradation and Inhibitors
- Aquaculture disease management and microbiota
- Renal Diseases and Glomerulopathies
- Autophagy in Disease and Therapy
- Renal Transplantation Outcomes and Treatments
- Coral and Marine Ecosystems Studies
- Bipolar Disorder and Treatment
- Hyperglycemia and glycemic control in critically ill and hospitalized patients
Université de Bordeaux
2010-2024
Centre National de la Recherche Scientifique
2010-2024
Inserm
2006-2024
Bordeaux Imaging Center
2013-2024
Bordeaux Population Health
2006-2024
Imaging Center
2020
Institut de Biologie Valrose
2017-2019
Université Côte d'Azur
2017-2018
Institut Interdisciplinaire de Neuroscience
2012-2014
Fondazione Umberto Di Mario
2010
The mechanisms governing the recruitment of functional glutamate receptors at nascent excitatory postsynapses following initial axon-dendrite contact remain unclear. We examined here ability neurexin/neuroligin adhesions to mobilize AMPA-type (AMPARs) through a diffusion/trap process involving scaffold molecule PSD-95. Using single nanoparticle tracking in primary rat and mouse hippocampal neurons overexpressing or lacking neuroligin-1 (Nlg1), striking inverse correlation was found between...
Trafficking of AMPA receptors (AMPARs) plays a key role in synaptic transmission. However, general framework integrating the two major mechanisms regulating AMPAR delivery at postsynapses (i.e., surface diffusion and internal recycling) is lacking. To this aim, we built model based on numerical trajectories individual AMPARs, including free extrasynaptic space, confinement synapse, trapping postsynaptic density (PSD) through reversible interactions with scaffold proteins. The AMPAR/scaffold...
A combination of cell culture and animal studies has recently shown that adhesion between neurexins neuroligins played important roles in synapse initiation, maturation, function. Binding neurexin-1β to neuroligin-1 triggers the postsynaptic clustering scaffold density protein 95, but composition timing accumulation glutamate receptors at those nascent contacts remain unclear. Using iontophoresis patch-clamp recordings, we identified functional AMPA (AMPARs) NMDA 95 clusters induced by...
The activation of glucocorticoid receptors (GR) by glucocorticoids increases stress-related memory through the MAPK signaling pathway and downstream transcription factor Egr-1. Here, using converging in vitro vivo approaches, respectively, GR-expressing cell lines, culture hippocampal neurons, GR genetically modified mice (GRNesCre), we identified synapsin-Ia/Ib as one effectors cascade. Stress glucocorticoid-induced modulate two complementary mechanisms. First, driving Egr-1 expression...
Adhesion between neurexin-1β (Nrx1β) and neuroligin-1 (Nlg1) induces early recruitment of the postsynaptic density protein 95 (PSD-95) scaffold; however, associated signaling mechanisms are unknown. To dissociate effects ligand binding receptor multimerization, we compared conditions in which Nlg1 neurons was bound to Nrx1β or nonactivating HA antibodies. Time-lapse imaging, fluorescence recovery after photobleaching, single-particle tracking demonstrated that addition aggregating Nlg1,...
Abstract Abnormal intraneuronal accumulation of soluble and insoluble α-synuclein (α-Syn) is one the main pathological hallmarks synucleinopathies, such as Parkinson’s disease (PD). It has been well documented that reversible liquid-liquid phase separation α-Syn can modulate synaptic vesicle condensates at presynaptic terminals. However, also form liquid-like droplets may convert into amyloid-enriched hydrogels or fibrillar polymorphs under stressful conditions. To advance our understanding...
Abstract R-spondin2 (RSPO2) is a member of the R-spondin family, which are secreted activators WNT/β-catenin (CTNNB1) signaling pathway. In mouse postnatal ovary, WNT/CTNNB1 active in oocyte and neighboring supporting cells, granulosa cells. Although role Rspo2 has been previously studied using vitro experiments, results conflicting vivo ovarian function remains unclear. present study, we found that RSPO2/Rspo2 expression restricted to developing follicles both human ovaries from beginning...
γ-Secretase is a multi-subunit enzyme whose aberrant activity associated with Alzheimer’s disease and cancer. While its structure atomically resolved, γ-secretase localization in the membrane situ relies mostly on biochemical data. Here, we combined fluorescent tagging of subunits super-resolution microscopy fibroblasts. Structured illumination revealed single complexes monodisperse distribution 1:1 stoichiometry PSEN1 nicastrin subunits. In living cells, sptPALM PSEN1/γ-secretase mainly...
The recent demonstration that pancreatic α cells can be continuously regenerated and converted into β-like upon ectopic expression of Pax4 opened new avenues research in the endocrine cell differentiation diabetes fields. To determine whether such plasticity was also shared by δ cells, we generated characterized transgenic animals express specifically somatostatin-expressing cells. We demonstrate is sufficient to induce their conversion functional Importantly, this induces compensatory...
The symbiotic interaction between cnidarians (e.g., corals and sea anemones) photosynthetic dinoflagellates of the genus Symbiodinium is triggered by both host-symbiont recognition processes metabolic exchange 2 partners. molecular communication crucial for homeostatic regulation symbiosis, under normal conditions during stresses that further lead to symbiosis collapse. It therefore important identify fully characterise key players this intimate at interface. In study, we determined cellular...
Finely tuned regulation of epithelial cell death maintains tissue integrity and homeostasis. At the cellular level, life decisions are controlled by environmental stimuli such as activation receptors. We show that polarity adherens junction formation prevent proapoptotic signals emanating from Fas receptor. is sequestered in E-cadherin actin-based adhesion structures less able to induce downstream apoptosis signaling. Using a proteomic-based approach, we find molecule Dlg1 interacts with...
The trafficking of ionotropic glutamate receptors to and from synaptic sites is regulated by proteins that interact with their cytoplasmic C-terminal domain. Profilin IIa (PfnIIa), an actin-binding protein expressed in the brain recruited synapses activity-dependent manner, was shown previously domain GluK2b subunit splice variant kainate (KARs). Here, we characterize this interaction examine role PfnIIa regulation KAR trafficking. directly specifically binds through a diproline motif....
Introduction The synaptic adhesion molecule neuroligin-1 (NLGN1) is involved in the differentiation of excitatory synapses, but precise underlying molecular mechanisms are still debated. Here, we explored role NLGN1 tyrosine phosphorylation this process, focusing on a subset receptor kinases (RTKs), namely FGFR1 and Trks, that were previously described to phosphorylate at unique intracellular residue (Y782). Methods We used pharmacological inhibitors genetic manipulation those RTKs...
Abstract The role of adhesion molecules in the assembly synapses nervous system is an important issue. To characterize neurexin/neuroligin complexes synapse differentiation, various imaging assays can be performed primary hippocampal cultures. First, to temporally control contact formation, biomimetic using microspheres coated with purified neurexin or antibody clusters that aggregate neurexin. These models are combined live fluorescence study dynamics accumulation post‐synaptic components,...
Super-resolution imaging provides unprecedented visualization of sub-cellular structures, but the two main techniques used, single-molecule localization microscopy (SMLM) and stimulated emission depletion (STED), are not easily reconciled. We present a protocol to super-impose nanoscale protein distribution reconstructed with SMLM morphology obtained in STED. describe steps for tracking cells on etched coverslips registering images from different microscopes 30-nm accuracy. In this protocol,...
Abstract Synaptic vesicles (SVs) are small organelles secreting neurotransmitters at synapses. By fusing a photoactivated fluorescent protein to VGLUT1, we generated VGLUT1 mEos2 knock-in mouse. mice viable and healthy, but exhibit severe reduction in expression levels. Using expressing neurons, established paradigms trace individual SV mobility the single-molecule level or via massive photoconversion. Hippocampal neurons with significantly diminished maintain unaltered miniature glutamate...
Background: Although several approaches have revealed much about individual factors that regulate pancreatic development, we yet to fully understand their complicated interplay during pancreas morphogenesis. Gfi1 is transcription factor specifically expressed in acinar cells, whose role cells fate identity and specification still elusive. Methods: In order gain further insight into the function of this pancreas, generated animals deficient for pancreas. conditional knockout were...
Basal autophagy is as a compressive catabolic mechanism engaged in the breakdown of damaged macromolecules and organelles leading to recycling elementary nutrients. Thought essential cellular refreshing, little known about origin constitutional rate basal autophagy. Here, we found that loss Drosophila vacuolar peduncle (vap), presumed GAP enzyme, associated with enhanced physiological alterations resulting wasteful cell energy balance, hallmark overactive By contrast, starvation-induced was...