Université PSL



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Glutamate spillover in C. elegans triggers repetitive behavior through presynaptic activation of MGL-2/mGluR5.
Laboratoire pour la biologie quantitative du développement - Katz M, Corson F, Keil W,Singhal A, Bae A, Lu Y, Liang Y, Shaham S.
Nat Commun - 10(1) 1882 - doi: 10.1038/s41467-019-09581-4. - 2019
Glutamate is a major excitatory neurotransmitter, and impaired glutamate clearance following synaptic release promotes spillover, inducing extra-synaptic signaling. The effects of glutamate spillover on animal behavior and its neural correlates are poorly understood. We developed a glutamate spillover model in Caenorhabditis elegans by inactivating the conserved glial glutamate transporter GLT-1. GLT-1 loss drives aberrant repetitive locomotory reversal behavior through uncontrolled oscillatory release of glutamate onto AVA, a major interneuron governing reversals. Repetitive glutamate release and reversal behavior require the glutamate receptor MGL-2/mGluR5, expressed in RIM and other interneurons presynaptic to AVA. mgl-2 loss blocks oscillations and repetitive behavior; while RIM activation is sufficient to induce repetitive reversals in glt-1 mutants. Repetitive AVA firing and reversals require EGL-30/Gαq, an mGluR5 effector. Our studies reveal that cyclic autocrine presynaptic activation drives repetitive reversals following glutamate spillover. That mammalian GLT1 and mGluR5 are implicated in pathological motor repetition suggests a common mechanism controlling repetitive behaviors.
Synthesis of benzaldehyde with high selectivity using immobilized AuNPs and AuNPs@zeolite in a catalytic microfluidic system
Laboratoire Procédés - Plasmas - Microsystèmes - Xi Rao, ORCID logo, Ali Abou Hassan, Cédric Guyon, Erick Osvaldo Martinez Ruiz, Michaël Tatoulianb and Stephanie Ognier
Lab. Chip - 17 - DOI: 10.1039/c9lc00386j - 2019
In the present work, gold based catalysts were synthesized and immobilized on the surface of cyclic olefin copolymer (COC) microreactors. The microreactors were subsequently applied in a homemade microfluidic system for synthesizing benzaldehyde by oxidation of benzyl alcohol in water medium. The Au nanoparticles (NPs) immobilized on the inner surface of the microchannel showed a very high selectivity (94%) for benzaldehyde, while zeolite NPs exhibited only an adsorption feature to this reaction. Moreover, the results showed that the AuNP catalytic activity was maintained for at least 9 hours. However, the obtained conversion with AuNPs was only 20%, indicating a relatively low productivity. In comparison, AuNPs assembled on the surface of zeolite NPs (AuNPs@zeolite) and immobilized in the microchannel showed the best catalytic performance, as the highest benzaldehyde selectivity (>99%) with a relatively high benzyl alcohol conversion of 42.4% was achieved under the same conditions. To the best of our knowledge, this is the first example demonstrating the use of AuNP or AuNP@zeolite catalysts in a microsystem performing such high selectivity for benzaldehyde in water medium.

Two-step local functionalization of fluoropolymer Dyneon THV microfluidic materials by scanning electrochemical microscopy combined to click reaction
Laboratoire Sciences Analytiques Bioanalytiques et Miniaturisation - Kadhirvel P, Combès A, Bordron L, Pichon V
Anal. Bioanal. Chem - 411(8) 1525-1536 - doi: 10.1007/s00216-019-01586-8 - 2019
A molecularly imprinted polymer (MIP) was designed in order to allow the selective solid-phase extraction of carbamazepine (CBZ), an anticonvulsant and mood-stabilizing drug, at ultra-trace level from aqueous environmental samples. A structural analog of CBZ was selected as a dummy template and different synthesis conditions were screened. The selectivity of the resulting imprinted polymers was evaluated by studying the retention of CBZ in a solvent similar to the one used for the synthesis. The presence of imprinted cavities in the polymers was then demonstrated by comparing the elution profiles (obtained by using MIP and a non-imprinted polymer, NIP, as a control) of the template, of CBZ, and of a structural analog of CBZ. Then, the extraction procedure was further optimized for the treatment of aqueous samples on the two most promising MIPs, with special attention being paid to the volume and composition of the percolation and washing solutions. The best MIP provided a highly selective retention in tap water with 81% extraction recovery for CBZ in the elution fraction of the MIP and only 14% for NIP. The repeatability of the extraction procedure was demonstrated for both tap and river waters (RSD below 4% in river water) for the drugs CBZ, oxcarbamazepine, and one metabolite (carbamazepine 10,11-epoxide). A MIP capacity of 1.15 μmol g-1 was determined. Finally, an analytical procedure involving the MIP was developed allowing the detection of CBZ at a concentration level of only a few nanograms per liter in river water. The selectivity provided by the MIP resulted in a 3000-fold increase of the signal-to-noise ratio in LC/MS analysis as compared to the use of conventional sorbent. Graphical abstract.
First profiling in hydrophilic interaction liquid chromatography of intact human chorionic gonadotropin isoforms.
Laboratoire Sciences Analytiques Bioanalytiques et Miniaturisation - Camperi J, Pichon V, Fournier T, Delaunay N
J Pharm Biomed Anal - 10;174 495-499. - doi: 10.1016/j.jpba.2019.06.014 - 2019
The study of glycoproteins is a rapidly growing field, which is not surprising considering that approximately 70% of human proteins are glycosylated and that numerous biological functions are associated to the glycosylation. In this work, our interest focused on the heterodimeric human Chorionic Gonadotropin (hCG) glycoprotein that is the specific hormone of the human pregnancy, consisting of an α and a β subunit, so-called hCGα and hCGβ, respectively. This protein possesses a very high structural heterogeneity, essentially due to the presence of 8 glycosylation sites, but also other types of post-translational modifications. In this study, for the first time, the potential of hydrophilic interaction liquid chromatography (HILIC) was investigated to separate the intact hCG isoforms. Three different HILIC stationary phases were tested using an hCG-based drug as standard, a recombinant hCG. For each stationary phase, the effect of the initial mobile phase composition based on ACN/H2O mixture, the slope of the gradient, the content and nature of the acidic additive (formic acid and trifluoroacetic acid (TFA)), and the addition of a volatile salt (ammonium formate) on the retention and the resolution were studied. The best HILIC separation was obtained with the amide column and a mobile phase composed of water/ACN containing 0.1% of TFA. The repeatability in terms of retention times and peak areas was then assessed. Finally, the method was applied to the analysis of a second hCG-based drug obtained from urine of pregnant women. Both drugs gave chromatograms with more than 10 peaks. However, they were significantly different, which demonstrated the potential of HILIC method for hCG isoform fingerprinting
Investigation of serum proteome homeostasis during radiation therapy by a quantitative proteomics approach
Laboratoire Spectrométrie de masse biologique et protéomique - Amira Ouerhani ; Giovanni Chiappetta ; Oussema Souiai ; Halima Mahjoubi ; Joelle Vinh
Biosci Rep - 39 (7) BSR20182319 - doi.org/10.1042/BSR20182319 - 2019
The purpose of the present study is to analyze the serum proteome of patients receiving Radiation Therapy (RT) at different stages of their treatment to discovery candidate biomarkers of the radiation-induced skin lesions and the molecular pathways underlying the radiation signatures. Six stages of RT treatment were monitored from patients treated because of brain cancer: before starting the treatment, during the treatment (four time points), and at 4 weeks from the last RT dose. Serum samples were analyzed by a proteomics approach based on the Data Independent Acquisition (DIA) mass spectrometry (MS). RT induced clear changes in the expression levels of 36 serum proteins. Among these, 25 proteins were down- or up-regulated significantly before the emergence of skin lesions. Some of these were still deregulated after the completion of the treatment. Few days before the appearance of the skin lesions, the levels of some proteins involved in the wound healing processes were down-regulated. The pathway analysis indicated that after partial body irradiation, the expression levels of proteins functionally involved in the acute inflammatory and immune response, lipoprotein process and blood coagulation, were deregulated.
Development of Immobilized Enzyme Reactors for the characterization of the glycosylation heterogeneity of a protein
Laboratoire Spectrométrie de masse biologique et protéomique - Stan Perchepied, Nicolas Eskenazi, Chiara Giangrande, Julien Camperi, Thierry Fournier, Joëlle Vinh, Nathalie Delaunay, Valérie Pichon
Biosci Rep - 206 120171 - doi.org/10.1016/j.talanta.2019.120171 - 2019
The mapping of post-translational modifications (PTMs) of proteins can be addressed by bottom-up proteomics strategy using proteases to achieve the enzymatic digestion of the biomolecule. Glycosylation is one of the most challenging PTM to characterize due to its large structural heterogeneity. In this work, two Immobilized Enzyme Reactors (IMERs) based on trypsin and pepsin protease were used for the first time to fasten and improve the reliability of the specific mapping of the N-glycosylation heterogeneity of glycoproteins. The performance of the supports was evaluated with the digestion of human Chorionic Gonadotropin hormone (hCG), a glycoprotein characterized by four N- and four O-glycosylation sites, prior to the analysis of the digests by nanoliquid chromatography coupled to tandem mass spectrometry (nanoLC-MS/MS). Firstly, the repeatability of the nanoLC-MS/MS was evaluated and a method to control the identification of the identified glycans was developed to validate them regarding the retention time of glycopeptides in reversed phase nanoLC separation. The repeatability of the digestion with trypsin-based IMER was evaluated on the same hCG batch and on three independent batches with common located glycans up to 75%. Then, the performance of the IMER digestions was compared to in-solution digestions to evaluate the qualitative mapping of the glycosylation. It has given rise to 42 out of 45 common glycans between both digestions modes. For the first time, the complementarity of trypsin and pepsin was illustrated for the glycosylation mapping as trypsin led to identifications on 2 out of 4 glycosylation site while pepsin was informative on the 4 glycosylation site. The potential of IMERs for the study of the glycosylation of a protein was illustrated with the comparison of two hCG-based drugs, Ovitrelle® and Pregnyl
Contribution of proteases and cellulases produced by solid-state fermentation to the improvement of corn ethanol production
Laboratoire Spectrométrie de masse biologique et protéomique - Anaïs Guillaume, Aurore Thorigné, Yoann Carré, Joëlle Vinh and Loïc Levavasseur
Biosci Rep - 6 7 - doi.org/10.1186/s40643-019-0241-0 - 2019
By cultivating a strain of Aspergillus tubingensis on agro-industrial by-products using solid-state fermentation technology, a biocatalyst containing more than 130 different enzymes was obtained. The enzymatic complex was composed mainly of hydrolases, among which a protease, an aspergillopepsin, accounted for more than half of the total proteins. Cell-wall-degrading enzymes such as pectinases, cellulases and hemicellulases were also highly represented. Adding the biocatalyst to corn mash at 1 kg/T corn allowed to significantly improve ethanol production performances. The final ethanol concentration was increased by 6.8% and the kinetics was accelerated by 14 h. The aim of this study was to identify the enzymes implicated in the effect on corn ethanol production. By fractionating the biocatalyst, the particular effect of the major enzymes was investigated. Experiments revealed that, together, the protease and two cellulolytic enzymes (an endoglucanase and a β-glucosidase) were responsible for 80% of the overall effect of the biocatalyst. Nevertheless, the crude extract of the biocatalyst showed greater impact than the combination of up to seven purified enzymes, demonstrating the complementary enzymatic complex obtained by solid-state fermentation. This technology could, therefore, be a relevant natural alternative to the use of GMO-derived enzymes in the ethanol industry.
Global host molecular perturbations upon in situ loss of bacterial endosymbionts in the deep-sea mussel Bathymodiolus azoricus assessed using proteomics and transcriptomics
Laboratoire Spectrométrie de masse biologique et protéomique - Détrée C1, Haddad I, Demey-Thomas E, Vinh J, Lallier FH, Tanguy A, Mary J
BMC Genomics - 20(1) 109 - doi: 10.1186/s12864-019-5456-0. - 2019
Colonization of deep-sea hydrothermal vents by most invertebrates was made efficient through their adaptation to a symbiotic lifestyle with chemosynthetic bacteria, the primary producers in these ecosystems. Anatomical adaptations such as the establishment of specialized cells or organs have been evidenced in numerous deep-sea invertebrates. However, very few studies detailed global inter-dependencies between host and symbionts in these ecosystems. In this study, we proposed to describe, using a proteo-transcriptomic approach, the effects of symbionts loss on the deep-sea mussel Bathymodiolus azoricus' molecular biology. We induced an in situ depletion of symbionts and compared the proteo-transcriptome of the gills of mussels in three conditions: symbiotic mussels (natural population), symbiont-depleted mussels and aposymbiotic mussels.

Global proteomic and transcriptomic results evidenced a global disruption of host machinery in aposymbiotic organisms. We observed that the total number of proteins identified decreased from 1118 in symbiotic mussels to 790 in partially depleted mussels and 761 in aposymbiotic mussels. Using microarrays we identified 4300 transcripts differentially expressed between symbiont-depleted and symbiotic mussels. Among these transcripts, 799 were found differentially expressed in aposymbiotic mussels and almost twice as many in symbiont-depleted mussels as compared to symbiotic mussels. Regarding apoptotic and immune system processes - known to be largely involved in symbiotic interactions - an overall up-regulation of associated proteins and transcripts was observed in symbiont-depleted mussels.

Overall, our study showed a global impairment of host machinery and an activation of both the immune and apoptotic system following symbiont-depletion. One of the main assumptions is the involvement of symbiotic bacteria in the inhibition and regulation of immune and apoptotic systems. As such, symbiotic bacteria may increase their lifespan in gill cells while managing the defense of the holobiont against putative pathogens.
Stress field inside the bath determines dip coating with yield-stress fluids in cylindrical geometry
MIE - Matériaux Innovants pour l'Energie - Wilbert J Smit, Christophe Kusina, Jean-François Joanny, Annie Colin
Phys. Rev. Lett. - 123(14) 148002 - - 2019
We study experimentally and theoretically the thickness of the coating obtained by pulling out a rod from a reservoir of yield-stress fluid. Opposite to Newtonian fluids, the coating thickness for a fluid of large enough yield stress is determined solely by the flow inside the reservoir and not by the flow inside the meniscus. The stress field inside the reservoir determines the thickness of the coating layer. The thickness is observed to increase nonlinearly with the sizes of the rod and of the reservoir. We develop a theoretical framework that describes this behavior and allows us to precisely predict the coating thickness.
Polymeric foams for flexible and highly sensitive low-pressure capacitive sensors
MIE - Matériaux Innovants pour l'Energie - Mickaël Pruvost, Wilbert J Smit, Cécile Monteux, Philippe Poulin, Annie Colin
npj Flexible Electronics - 1 7 - - 2019
Flexible low-pressure sensors (< 10 kPa) are required in areas as diverse as blood-pressure monitoring, human–computer interactions, robotics, and object detection. For applications, it is essential that these sensors combine flexibility, high sensitivity, robustness, and low production costs. Previous works involve surface micro-patterning, electronic amplification (OFET), and hydrogels. However, these solutions are limited as they involve complex processes, large bias voltages, large energy consumption, or are sensitive to evaporation. Here, we report a major advance to solve the challenge of scalable, efficient and robust e-skin. We present an unconventional capacitive sensor based on composite foam materials filled with conductive carbon black particles. Owing to the elastic buckling of the foam pores, the sensitivity exceeds 35 kPa− 1 for pressure< 0.2 kPa. These performances are one order of magnitude …

410 publications.