Université PSL

Publications

RECHERCHER

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Nano-on-Micro Fibrous Extracellular Matrices for Scalable Expansion of Human Es/Ips Cells
Laboratoire Pôle Microfluidique - L. Liu, K.-i. Kamei, M. Yoshioka, M. Nakajima, J. Li, N. Fujimoto, S. Terada, Y. Tokunaga, Y. Koyama, H. Sato, K. Hasegawa, N. Nakatsuji and Y. Chen
Biomaterials - 124 47-54 - DOI: 10.1016/j.biomaterials.2017.01.039 - 2019
Human pluripotent stem cells (hPSCs) hold great potential for industrial and clinical applications. Clinical-grade scaffolds and high-quality hPSCs are required for cell expansion as well as easy handling and manipulation of the products. Current hPSC culture methods do not fulfill these requirements because of a lack of proper extracellular matrices (ECMs) and cell culture wares. We developed a layered nano-on-micro fibrous cellular matrix mimicking ECM, named "fiber-on-fiber (FF)" matrix, which enables easy handling and manipulation of cultured cells. While non-woven sheets of cellulose and polyglycolic acid were used as a microfiber layer facilitating mechanical stability, electrospun gelatin nanofibers were crosslinked on the microfiber layer, generating a mesh structure with connected nanofibers facilitating cell adhesion and growth. Our results showed that the FF matrix supports effective hPSC culture with maintenance of their pluripotency and normal chromosomes over two months, as well as effective scaled-up expansion, with fold increases of 54.1 ± 15.6 and 40.4 ± 8.4 in cell number per week for H1 human embryonic stem cells and 253G1 human induced pluripotent stem cells, respectively. This simple approach to mimick the ECM may have important implications after further optimization to generate lineage-specific products.
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.
HLH-2/E2A Expression Links Stochastic and Deterministic Elements of a Cell Fate Decision during C. elegans Gonadogenesis
Laboratoire pour la biologie quantitative du développement - Michelle A.Attner, WolfgangKeil, Justin M.Benavidez, IvaGreenwald
Nat Commun - 29(18) 3094-3100.e4 - https://doi.org/10.1016/j.cub.2019.07.062 - 2019
Stochastic mechanisms diversify cell fate in organisms ranging from bacteria to humans [1, 2, 3, 4]. In the anchor cell/ventral uterine precursor cell (AC/VU) fate decision during C. elegans gonadogenesis, two “α cells,” each with equal potential to be an AC or a VU, interact via LIN-12/Notch and its ligand LAG-2/DSL [5, 6]. This LIN-12/Notch-mediated interaction engages feedback mechanisms that amplify a stochastic initial difference between the two α cells, ensuring that the cell with higher lin-12 activity becomes the VU while the other becomes the AC [7, 8, 9]. The initial difference between the α cells was originally envisaged as a random imbalance from “noise” in lin-12 expression/activity [6]. However, subsequent evidence that the relative birth order of the α cells biases their fates suggested other factors may be operating [7]. Here, we investigate the nature of the initial difference using high-throughput lineage analysis [10]; GFP-tagged endogenous LIN-12, LAG-2, and HLH-2, a conserved transcription factor that orchestrates AC/VU development [7, 11]; and tissue-specific hlh-2 null alleles. We identify two stochastic elements: relative birth order, which largely originates at the beginning of the somatic gonad lineage three generations earlier, and onset of HLH-2 expression, such that the α cell whose parent expressed HLH-2 first is biased toward the VU fate. We find that these elements are interrelated, because initiation of HLH-2 expression is linked to the birth of the parent cell. Finally, we provide a potential deterministic mechanism for the HLH-2 expression bias by showing that hlh-2 is required for LIN-12 expression in the α cells.
A new injection system for spraying liquid nitrates in a low power plasma reactor: Application to local repair of damaged thermal barrier coating
Laboratoire Procédés - Plasmas - Microsystèmes - F.Rousseau A.Quinsac D.Morvan M.-P.Bacos O.Lavigne C.Rio C.Guinard B.Chevillard
ELSEVIER - 357 195-203 - https://doi.org/10.1016/j.surfcoat.2018.09.069 - 2019
In addition to the search for new Thermal Barrier Coating (TBCs) systems with increased reliability over very long time periods, the repair of current systems is a technological and economic issue for both civilian and military engine end-users. This paper describes the latest version of the deposition process known as the Low-Power Plasma Reactor (LPPR) process, specially developed to repair locally damaged TBCs. The LPPR process enables micro/nanostructured TBCs to be made from nitrate salts in aqueous solutions, which are sprayed in an Ar/O2 plasma discharge at low power (240 W) and transformed into oxide coatings. A new injection device was designed to produce a fairly homogenous and reproducible spray to repair partially spalled APS and EB-PVD TBCs deposited on small flat coupons. The microstructure and the stability of the LPPR TBCs were assessed, in particular using SEM observations, during ageing tests under various time/temperature conditions. The Particle Image Velocimetry (PIV) technique and associated modeling have proved that the nitrates impact the substrate in a liquid state even in the presence of plasma and a vacuum. Due to the liquid state of the precursors, the new LPPR TBC seals the damaged areas and deeply infiltrates all porosities and failure cracks in the original coatings. This research has enabled the new version of the LPPR process to be validated as a simple, efficient, cheap and promising way to repair locally damaged TBCs
Cross coupling of alkylsilicates with acyl chlorides via photoredox/nickel dual catalysis: a new synthesis method for ketones
Laboratoire Procédés - Plasmas - Microsystèmes - Etienne Levernier, Vincent Corcé, Louise-Marie Rakotoarison, Adrien Smith, Mengxue Zhang, Stephanie Ognier, Michael Tatoulian, Cyril Ollivier and Louis Fensterbank
Organic Chemistry Frontiers - 6 1378-1382 - https://doi.org/10.1039/C9QO00092E - 2019
Photoredox/nickel dual catalysis using easily oxidized bis-catecholato hypercoordinated silicon derivatives as radical sources and acyl chlorides as electrophiles allows a new method of formation of dialkyl and alkyl-aryl ketones as well as dibenzyl ketones which are less easily accessed. Flow chemistry can be used.
Plasma-catalytic hybrid process for CO2 methanation: optimization of operation parameters
Laboratoire Procédés - Plasmas - Microsystèmes - M. Mikhail, B. Wang, R. Jalain, S. Cavadias, M. Tatoulian, S. Ognier, M. E. Gálvez & P. Da Costa
Reaction Kinetics, Mechanisms and Catalysis - 126 629–643 - doi.org/10.1007/s11144-018-1508-8 - 2019
The present study focuses on the hybrid plasma catalytic process for CO2 methanation. This plasma-catalytic process, based on the combination of a DBD plasma and Ni/CeZrO2 catalyst, has several advantages over conventional catalysis: it operates at ambient conditions and requires no external heating. An optimization of the process considering the effect of the different operational parameters such as voltage, GHSV, catalyst mass, flow rate, discharge length, is herein presented. Moreover, a spectroscopic study, aiming to understand the mechanism of the reaction, is also showed. At temperatures around 270 °C and under adiabatic conditions, CO2 conversion rates of about 80% were measured, with a CH4 selectivity greater than 95%.
Surface functionalization of cyclic olefin copolymer by plasma‐enhanced chemical vapor deposition using atmospheric pressure plasma jet for microfluidic applications
Laboratoire Procédés - Plasmas - Microsystèmes - Samantha Bourg Sophie Griveau Fanny d'Orlyé Michael Tatoulian Fethi Bedioui Cédric Guyon Anne Varenne
FULL PAPER - 16 6 - doi.org/10.1002/ppap.201800195 - 2019
Lab‐On‐A‐Chips promise solutions for high throughput and specific analysis for environmental and health applications, with the challenge to develop materials allowing fast, easy, and cheap microfabrication and efficient surface treatment. Cyclic olefin copolymer (COC) is a promising thermoplastic, easily microfabricated for both rapid prototyping and low‐cost mass production of microfluidic devices but still needing efficient surface modification strategies. This study reports for the first time the optimization of an easy COC silica coating process by plasma‐enhanced chemical vapor deposition at atmospheric pressure with plasma jet and tetraethylorthosilicate as precursor, leading to a 158 ± 7 nm thickness and a 14‐day‐stability of hydrophilic properties for a COC‐embedded microchannel (100 µm), paving the way for a simplified and controlled COC surface modification.
Synthesis of benzaldehyde with high selectivity using immobilized AuNPs and AuNPs@zeolite in a catalytic microfluidic system
Laboratoire Procédés - Plasmas - Microsystèmes - Xi Rao, Ali Abou Hassan, Cédric Guyon, Erick Osvaldo Martinez Ruiz, Michaël Tatoulian and Stephanie Ognier
Lab. Chip - 19 2866-2873 - https://doi.org/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.

Degradation of glucocorticoids in aqueous solution by dielectric barrier discharge: Kinetics, mechanisms, and degradation pathways
Laboratoire Procédés - Plasmas - Microsystèmes - Liu YN, Wang CH, Shen X, Zhang A, Yan SW, Li X, Miruka AC, Wu SM, Guo Y, Ognier S
Chemical Engineering Journal - 374 412-428 - DOI10.1016/j.cej.2019.05.154 - 2019
Performance and mechanism of non-thermal plasma (NTP) technology in removing glucocorticoids (GCs) was investigated using a dielectric barrier discharge (DBD) reactor with fluocinolone acetonide (FA), triamcinolone acetonide (TA) and clobetasol propionate (CP) as representative compounds. Effects of discharge power, plasma-working gases, initial pH, coexistence of ions, and various water matrices (ultrapure water, lake water, drinking water, wastewater effluent) on GC removal and energy yield were evaluated. The results confirm that DBD treatment could efficiently remove FA, TA, and CP, achieving efficiency of 72% (k = 0.0126 min(-1)), 71% (k = 0.0096 min(-1)), and 74% (k = 0.0116 min(-1)), respectively in air-DBD system at 45.2 W, with the process following the first order kinetics and energy yield of 6 mg kW(-1) h(-1). The removal efficiency decreased when adding radical scavengers, indicating that hydroxyl radicals played an important role in GC degradation, while other active species (such as solvated electrons (e(aq)(-)), ozone (O-3), hydrogen peroxide (H2O2) and ultraviolet photolysis (UV)) also contribute to GC degradation. The intermediates generated during the process were analyzed using quadrupole time-of-flight mass spectrometry (QTOF-MS). A total of 23 transformation products of FA, TA and CP were identified, and it was noted that substitution of halogen atoms with center dot OH, oxidation of hydroxyl group to keto acid, decarboxylation of the keto acid, addition of center dot OH, intramolecular cyclization, and hydrolysis of esters occurred during GC degradation by DBD treatment.
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.

Plasma Polymer Layers with Primary Amino Groups for Immobilization of Nano- and Microparticles
Laboratoire Procédés - Plasmas - Microsystèmes - Xi Rao; Ali Abou Hassan; Cédric Guyon; Mengxue Zhang; Stephanie Ognier; Michaël Tatoulian
Plasma Chemistry and Plasma Processing - 2 178 - DOI: 10.1007/s11090-019-10056-z - 2019
The assembly of nano- and micro-scale building blocks on surface has been the focus of intense interest in materials science for years. In this work, (3-aminopropyl)triethoxysilane (APTES) carrying one primary amino group was deposited on various substrate surfaces using the plasma polymerization method. The key plasma parameters i.e. pressure and power were varied to obtained the highest density of primary amino groups. The influence of such parameters on the characteristics of deposited layers (e.g. chemical structure, adhesion strength, growth rate, etc.) was systemically investigated using various characterization methods such as XPS, FTIR, ellipsometry and so on. Meanwhile, three types of particles (AuNPs, zeolites and gold@zeolites) with sizes from nano- to submicro-range were synthesized and further used as model building blocks. Subsequently, the prepared particles were deposited onto cyclic olefin copolymer (COC) substrate surfaces, which were pre-functionalized by deposition of the plasma polymer layer using the parameters of pressure = 1.0 mbar and power = 30 W. The results confirmed the formation of membrane structures consisting of highly packed particles on the COC surface, and such immobilized structures showed high stability against flowing water, evidencing the good immobilization ability of deposited APTES layers with amino groups.
Thermo-mechanical and photo-luminescence properties of micro-actuators made of liquid crystal elastomers with cyano-oligo(p-phenylene vinylene) crosslinking bridges
Laboratoire Procédés - Plasmas - Microsystèmes - Bin Ni, Hui Chen, Mengxue Zhang, Patrick Keller, Michael Tatoulian and Min-Hui Li
Materials Chemisty Frontiers - 3 2499-2506 - https://doi.org/10.1039/C9QM00480G - 2019
Nematic liquid crystal elastomer (LCE) micropillars with reversible thermomechanical deformations and photo luminescence (PL) intensity variations were successfully fabricated by introducing a cyano-oligo(p-phenylene vinylene) dye as a chemical crosslinker. The PL intensity of the micropillars decreased and increased reversibly during the thermal-deformation process. We studied in detail the possible factors that influence the PL intensity variations of the micropillars, including temperature variation, contraction/extension and phase transition. The dye molecules mainly kept the “monomer” state in the micropillars during the thermo-activated deformation. It was found that the phase transition from nematic to isotropic of the LCEs played the major role in the PL intensity variations. This kind of micropillar may have potential application in fluorescent soft sensors and actuators.

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
BACKGROUND:
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.

RESULTS:
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.

CONCLUSION:
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.
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
ELSEVIER - 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
Physicochemical Characterization of Phthalocyanine-Functionalized Quantum Dots by Capillary Electrophoresis Coupled to a LED Fluorescence Detector
Laboratoire Synthèse Electrochimie Imagerie et Systèmes Analytiques - Ramírez-García G, d'Orlyé F, Nyokong T, Bedioui F, Varenne A
Methods in Molecular Biology (Clifton, N.J.) - 2000 373-385 - DOI: 10.1007/978-1-4939-9516-5_23 - 2019
Capillary zone electrophoresis (CZE) complemented with Taylor Dispersion Analysis-CE (TDA-CE) was developed to physicochemically characterize phthalocyanine-capped core/shell/shell quantum dots (QDs) at various pH and ionic strengths. An LED-induced fluorescence detector was used to specifically detect the QDs. The electropherograms and taylorgrams allowed calculating the phthalocyanine-QDs (Pc-QDs) ζ-potential and size, respectively, and determining the experimental conditions for colloidal stability. This methodology allowed evidencing either a colloidal stability or an aggregation state according to the background electrolytes nature. The calculated ζ-potential values of Pc-QDs decreased when ionic strength increased, being well correlated with the aggregation of the nanoconjugates at elevated salt concentrations. For the same reason, the hydrodynamic diameter of Pc-QDs increased with increasing background electrolyte ionic strength. The use of electrokinetic methodologies has provided insights into the colloidal stability of the photosensitizer-functionalized QDs in physiologically relevant solutions and, thereby, its usefulness for improving their design and applications for photodynamic therapy.

515 publications.