Publications

@article{pmid37655966,

title = {Activation of Nod2 signaling upon norovirus infection enhances antiviral immunity and susceptibility to colitis},

author = {Ghaffar Muharram and Marion Thépaut and Pierre-Emmanuel Lobert and Teddy Grandjean and Olivier Boulard and Myriam Delacre and Emmrich Wakeford and Richard Wheeler and Lionel Franz Poulin and Ivo Gomperts Boneca and Frank Lafont and Marie-Cécile Michallet and Didier Hober and Ken Cadwell and Mathias Chamaillard},

doi = {10.1080/19490976.2023.2249960},

issn = {1949-0984},

year  = {2023},

date = {2023-12-01},

journal = {Gut Microbes},

volume = {15},

number = {2},

pages = {2249960},

abstract = {Over 90% of epidemic non-bacterial gastroenteritis are caused by human noroviruses (NoVs), which persist in a substantial subset of people allowing their spread worldwide. This has led to a significant number of endemic cases and up to 70,000 children deaths in developing countries. NoVs are primarily transmitted through the fecal-oral route. To date, studies have focused on the influence of the gut microbiota on enteric viral clearance by mucosal immunity. In this study, the use of mouse norovirus S99 (MNoV_S99) and CR6 (MNoV_CR6), two persistent strains, allowed us to provide evidence that the norovirus-induced exacerbation of colitis severity relied on bacterial sensing by nucleotide-binding oligomerization domain 2 (Nod2). Consequently, -deficient mice showed reduced levels of gravity of Dextran sodium sulfate (DSS)-induced colitis with both viral strains. And MNoV_CR6 viremia was heightened in  mice in comparison with animals hypomorphic for , which are prone to aggravated inflammation under DSS. Accordingly, the infection of macrophages derived from WT mice promoted the phosphorylation of Signal Transducer and Activator of Transcription 1 (STAT1) and NOD2's expression levels. Higher secretion of Tumor Necrosis Factor alpha (TNF) following NOD2 activation and better viral clearance were measured in these cells. By contrast, reduced levels of pSTAT1 and blunted downstream secretion of TNF were found in -deficient macrophages infected by MNoV_S99. Hence, our results uncover a previously unidentified virus-host-bacterial interplay that may represent a novel therapeutic target for treating noroviral origin gastroenteritis that may be linked with susceptibility to several common illnesses such as Crohn's disease.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid37378568,

title = {Coupled mechanical mapping and interference contrast microscopy reveal viscoelastic and adhesion hallmarks of monocyte differentiation into macrophages},

author = {Mar Eroles and Javier Lopez-Alonso and Alexandre Ortega and Thomas Boudier and Khaldoun Gharzeddine and Frank Lafont and Clemens M Franz and Arnaud Millet and Claire Valotteau and Felix Rico},

doi = {10.1039/d3nr00757j},

issn = {2040-3372},

year  = {2023},

date = {2023-06-01},

journal = {Nanoscale},

abstract = {Monocytes activated by pro-inflammatory signals adhere to the vascular endothelium and migrate from the bloodstream to the tissue ultimately differentiating into macrophages. Cell mechanics and adhesion play a crucial role in macrophage functions during this inflammatory process. However, how monocytes change their adhesion and mechanical properties upon differentiation into macrophages is still not well understood. In this work, we used various tools to quantify the morphology, adhesion, and viscoelasticity of monocytes and differentiatted macrophages. Combination of atomic force microscopy (AFM) high resolution viscoelastic mapping with interference contrast microscopy (ICM) at the single-cell level revealed viscoelasticity and adhesion hallmarks during monocyte differentiation into macrophages. Quantitative holographic tomography imaging revealed a dramatic increase in cell volume and surface area during monocyte differentiation and the emergence of round and spread macrophage subpopulations. AFM viscoelastic mapping showed important stiffening (increase of the apparent Young's modulus, ) and solidification (decrease of cell fluidity, ) on differentiated cells that correlated with increased adhesion area. These changes were enhanced in macrophages with a spread phenotype. Remarkably, when adhesion was perturbed, differentiated macrophages remained stiffer and more solid-like than monocytes, suggesting a permanent reorganization of the cytoskeleton. We speculate that the stiffer and more solid-like microvilli and lamellipodia might help macrophages to minimize energy dissipation during mechanosensitive activities. Thus, our results revealed viscoelastic and adhesion hallmarks of monocyte differentiation that may be important for biological function.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid36870686,

title = {Structure and dynamics of ESCRT-III membrane remodeling proteins by high-speed atomic force microscopy},

author = {Nebojsa Jukic and Alma P Perrino and Lorena Redondo-Morata and Simon Scheuring},

doi = {10.1016/j.jbc.2023.104575},

issn = {1083-351X},

year  = {2023},

date = {2023-03-01},

journal = {J Biol Chem},

pages = {104575},

abstract = {Endosomal Sorting Complex Required for Transport (ESCRT) proteins assemble on the cytoplasmic leaflet of membranes and remodel them. ESCRT is involved in biological processes where membranes are bent away from the cytosol, constricted, and finally severed, such as in multi-vesicular body formation (in the endosomal pathway for protein sorting) or abscission during cell division. The ESCRT system is hijacked by enveloped viruses to allow buds of nascent virions to be constricted, severed and released. ESCRT-III proteins, the most downstream components of the ESCRT system, are monomeric and cytosolic in their autoinhibited conformation. They share a common architecture, a four-helix bundle with a fifth helix that interacts with this bundle to prevent polymerizing. Upon binding to negatively charged membranes, the ESCRT-III components adopt an activated state that allows them to polymerize into filaments and spirals, and to interact with the AAA-ATPase Vps4 for polymer remodeling. ESCRT-III has been studied with electron microscopy (EM) and fluorescence microscopy (FM); these methods provided invaluable information about ESCRT assembly structures or their dynamics, respectively, but neither approach provides detailed insights into both aspects simultaneously. High-speed atomic force microscopy (HS-AFM) has overcome this shortcoming, providing movies at high spatio-temporal resolution of biomolecular processes, significantly increasing our understanding of ESCRT-III structure and dynamics. Here, we review the contributions of HS-AFM in the analysis of ESCRT-III, focusing on recent developments of non-planar and deformable HS-AFM supports. We divide the HS-AFM observations into four sequential steps in the ESCRT-III lifecycle: 1) polymerization, 2) morphology, 3) dynamics, and 4) depolymerization.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid36745905,

title = {Precision of neuronal localization in 2D cell cultures by using high-performance electropolymerized microelectrode arrays correlated with optical imaging},

author = {Mahdi Ghazal and Corentin Scholaert and Corentin Dumortier and Camille Lefebvre and Nicolas Barois and Sebastien Janel and Mehmet Cagatay Tarhan and Morvane Colin and Luc Buée and Sophie Halliez and Sebastien Pecqueur and Yannick Coffinier and Fabien Alibart and Pierre Yger},

doi = {10.1088/2057-1976/acb93e},

issn = {2057-1976},

year  = {2023},

date = {2023-03-01},

journal = {Biomed Phys Eng Express},

volume = {9},

number = {3},

abstract = {Recently, the development of electronic devices to extracellularly record the simultaneous electrical activities of numerous neurons has been blooming, opening new possibilities to interface and decode neuronal activity. In this work, we tested how the use of EDOT electropolymerization to tune post-fabrication materials could optimize the cell/electrode interface of such devices. Our results showed an improved signal-to-noise ratio, better biocompatibility, and a higher number of neurons detected in comparison with gold electrodes. Then, using such enhanced recordings with 2D neuronal cultures combined with fluorescent optical imaging, we checked the extent to which the positions of the recorded neurons could be estimated solely via their extracellular signatures. Our results showed that assuming neurons behave as monopoles, positions could be estimated with a precision of approximately tens of micrometers.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{GHAZAL2023115538,

title = {Electropolymerization processing of side-chain engineered EDOT for high performance microelectrode arrays},

author = {Mahdi Ghazal and Anna Susloparova and Camille Lefebvre and Michel Daher Mansour and Najami Ghodhbane and Alexis Melot and Corentin Scholaert and David Guérin and Sébastien Janel and Nicolas Barois and Morvane Colin and Luc Buée and Pierre Yger and Sophie Halliez and Yannick Coffinier and Sébastien Pecqueur and Fabien Alibart},

url = {https://www.sciencedirect.com/science/article/pii/S0956566323004803},

doi = {https://doi.org/10.1016/j.bios.2023.115538},

issn = {0956-5663},

year  = {2023},

date = {2023-01-01},

journal = {Biosensors and Bioelectronics},

volume = {237},

pages = {115538},

abstract = {Microelectrode Arrays (MEAs) are popular tools for in vitro extracellular recording. They are often optimized by surface engineering to improve affinity with neurons and guarantee higher recording quality and stability. Recently, PEDOT:PSS has been used to coat microelectrodes due to its good biocompatibility and low impedance, which enhances neural coupling. Herein, we investigate on electro-co-polymerization of EDOT with its triglymated derivative to control valence between monomer units and hydrophilic functions on a conducting polymer. Molecular packing, cation complexation, dopant stoichiometry are governed by the glycolation degree of the electro-active coating of the microelectrodes. Optimal monomer ratio allows fine-tuning the material hydrophilicity and biocompatibility without compromising the electrochemical impedance of microelectrodes nor their stability while interfaced with a neural cell culture. After incubation, sensing readout on the modified electrodes shows higher performances with respect to unmodified electropolymerized PEDOT, with higher signal-to-noise ratio (SNR) and higher spike counts on the same neural culture. Reported SNR values are superior to that of state-of-the-art PEDOT microelectrodes and close to that of state-of-the-art 3D microelectrodes, with a reduced fabrication complexity. Thanks to this versatile technique and its impact on the surface chemistry of the microelectrode, we show that electro-co-polymerization trades with many-compound properties to easily gather them into single macromolecular structures. Applied on sensor arrays, it holds great potential for the customization of neurosensors to adapt to environmental boundaries and to optimize extracted sensing features.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid36541039,

title = {Study of the persistence and dynamics of recombinant mCherry-producing Yarrowia lipolytica strains in the mouse intestine using fluorescence imaging},

author = {Catherine Madzak and Sabine Poiret and Sophie Salomé Desnoulez and Benoit Foligné and Frank Lafont and Catherine Daniel},

doi = {10.1111/1751-7915.14178},

issn = {1751-7915},

year  = {2022},

date = {2022-12-01},

journal = {Microb Biotechnol},

abstract = {Yarrowia lipolytica is a dimorphic oleaginous non-conventional yeast widely used as a powerful host for expressing heterologous proteins, as well as a promising source of engineered cell factories for various applications. This microorganism has a documented use in Feed and Food and a GRAS (generally recognized as safe) status. Moreover, in vivo studies demonstrated a beneficial effect of this yeast on animal health. However, despite the focus on Y. lipolytica for the industrial manufacturing of heterologous proteins and for probiotic effects, its potential for oral delivery of recombinant therapeutic proteins has seldom been evaluated in mammals. As the first steps towards this aim, we engineered two Y. lipolytica strains, a dairy strain and a laboratory strain, to produce the model fluorescent protein mCherry. We demonstrated that both Y. lipolytica strains transiently persisted for at least 1 week after four daily oral administrations and they maintained the active expression of mCherry in the mouse intestine. We used confocal microscopy to image individual Y. lipolytica cells of freshly collected intestinal tissues. They were found essentially in the lumen and they were rarely in contact with epithelial cells while transiting through the ileum, caecum and colon of mice. Taken as a whole, our results have shown that fluorescent Y. lipolytica strains constitute novel tools to study the persistence and dynamics of orally administered yeasts which could be used in the future as oral delivery vectors for the secretion of active therapeutic proteins in the gut.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid36400835,

title = {Molecular recognition of a membrane-anchored HIV-1 pan-neutralizing epitope},

author = {Johana Torralba and Igor de la Arada and Angélica Partida-Hanon and Edurne Rujas and Madalen Arribas and Sara Insausti and Claire Valotteau and Javier Valle and David Andreu and José M M Caaveiro and María Angeles Jiménez and Beatriz Apellániz and Lorena Redondo-Morata and José L Nieva},

doi = {10.1038/s42003-022-04219-6},

issn = {2399-3642},

year  = {2022},

date = {2022-11-01},

journal = {Commun Biol},

volume = {5},

number = {1},

pages = {1265},

abstract = {Antibodies against the carboxy-terminal section of the membrane-proximal external region (C-MPER) of the HIV-1 envelope glycoprotein (Env) are considered as nearly pan-neutralizing. Development of vaccines capable of producing analogous broadly neutralizing antibodies requires deep understanding of the mechanism that underlies C-MPER recognition in membranes. Here, we use the archetypic 10E8 antibody and a variety of biophysical techniques including single-molecule approaches to study the molecular recognition of C-MPER in membrane mimetics. In contrast to the assumption that an interfacial MPER helix embodies the entire C-MPER epitope recognized by 10E8, our data indicate that transmembrane domain (TMD) residues contribute to binding affinity and specificity. Moreover, anchoring to membrane the helical C-MPER epitope through the TMD augments antibody binding affinity and relieves the effects exerted by the interfacial MPER helix on the mechanical stability of the lipid bilayer. These observations support that addition of TMD residues may result in more efficient and stable anti-MPER vaccines.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid36229487,

title = {Optineurin links Hace1-dependent Rac ubiquitylation to integrin-mediated mechanotransduction to control bacterial invasion and cell division},

author = {Serena Petracchini and Daniel Hamaoui and Anne Doye and Atef Asnacios and Florian Fage and Elisa Vitiello and Martial Balland and Sebastien Janel and Frank Lafont and Mukund Gupta and Benoit Ladoux and Jerôme Gilleron and Teresa M Maia and Francis Impens and Laurent Gagnoux-Palacios and Mads Daugaard and Poul H Sorensen and Emmanuel Lemichez and Amel Mettouchi},

doi = {10.1038/s41467-022-33803-x},

issn = {2041-1723},

year  = {2022},

date = {2022-10-01},

journal = {Nat Commun},

volume = {13},

number = {1},

pages = {6059},

abstract = {Extracellular matrix (ECM) elasticity is perceived by cells via focal adhesion structures, which transduce mechanical cues into chemical signalling to conform cell behavior. Although the contribution of ECM compliance to the control of cell migration or division is extensively studied, little is reported regarding infectious processes. We study this phenomenon with the extraintestinal Escherichia coli pathogen UTI89. We show that UTI89 takes advantage, via its CNF1 toxin, of integrin mechanoactivation to trigger its invasion into cells. We identify the HACE1 E3 ligase-interacting protein Optineurin (OPTN) as a protein regulated by ECM stiffness. Functional analysis establishes a role of OPTN in bacterial invasion and integrin mechanical coupling and for stimulation of HACE1 E3 ligase activity towards the Rac1 GTPase. Consistent with a role of OPTN in cell mechanics, OPTN knockdown cells display defective integrin-mediated traction force buildup, associated with limited cellular invasion by UTI89. Nevertheless, OPTN knockdown cells display strong mechanochemical adhesion signalling, enhanced Rac1 activation and increased cyclin D1 translation, together with enhanced cell proliferation independent of ECM stiffness. Together, our data ascribe a new function to OPTN in mechanobiology.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid36103541,

title = {The emergence of spontaneous coordinated epithelial rotation on cylindrical curved surfaces},

author = {Alexandros Glentis and Carles Blanch-Mercader and Lakshmi Balasubramaniam and Thuan Beng Saw and Joseph d'Alessandro and Sebastien Janel and Audrey Douanier and Benedicte Delaval and Frank Lafont and Chwee Teck Lim and Delphine Delacour and Jacques Prost and Wang Xi and Benoit Ladoux},

doi = {10.1126/sciadv.abn5406},

issn = {2375-2548},

year  = {2022},

date = {2022-09-01},

journal = {Sci Adv},

volume = {8},

number = {37},

pages = {eabn5406},

abstract = {Three-dimensional collective epithelial rotation around a given axis represents a coordinated cellular movement driving tissue morphogenesis and transformation. Questions regarding these behaviors and their relationship with substrate curvatures are intimately linked to spontaneous active matter processes and to vital morphogenetic and embryonic processes. Here, using interdisciplinary approaches, we study the dynamics of epithelial layers lining different cylindrical surfaces. We observe large-scale, persistent, and circumferential rotation in both concavely and convexly curved cylindrical tissues. While epithelia of inverse curvature show an orthogonal switch in actomyosin network orientation and opposite apicobasal polarities, their rotational movements emerge and vary similarly within a common curvature window. We further reveal that this persisting rotation requires stable cell-cell adhesion and Rac-1-dependent cell polarity. Using an active polar gel model, we unveil the different relationships of collective cell polarity and actin alignment with curvatures, which lead to coordinated rotational behavior despite the inverted curvature and cytoskeleton order.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid36012472,

title = {A Unique Enhancement of Propionibacterium freudenreichii's Ability to Remove Pb(II) from Aqueous Solution by Tween 80 Treatment},

author = {Fanny George and Marie Titécat and Nicolas Barois and Catherine Daniel and Anne Garat and Gwénaël Jan and Benoît Foligné},

doi = {10.3390/ijms23169207},

issn = {1422-0067},

year  = {2022},

date = {2022-08-01},

urldate = {2022-08-01},

journal = {Int J Mol Sci},

volume = {23},

number = {16},

abstract = {Microbial agents have promise for the bioremediation of Pb(II)-polluted environments and wastewater, the biodecontamination of foods, and the alleviation of toxicity in living organisms. The dairy bacterium  is poorly able to remove Pb(II) from aqueous solution at 25 ppm, ranging from 0 to 10% of initial concentration. Here, we report on an original strong enhancement of this activity (ranging from 75% to 93%,  < 0.01) following the addition of a polysorbate detergent (Tween 80) during or either shortly after the growth of a  culture. We evaluated the optimal Tween 80 concentration for pretreatment conditions, documented the role of other detergents, and explored the possible mechanisms involved. Our results reveal a novel, environmentally friendly, low-cost pretreatment procedure for enhancing the selective removal of lead from water by probiotic-documented bacteria.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid35673929,

title = {Deciphering pathological remodelling of the human cartilage extracellular matrix in osteoarthritis at the supramolecular level},

author = {Ilhem Lilia Jaabar and Pauline Cornette and Antoine Miche and Kristell Wanherdrick and Vincent Dupres and François-Paul Ehkirch and Adeline Cambon Binder and Francis Berenbaum and Xavier Houard and Jessem Landoulsi},

doi = {10.1039/d2nr00474g},

issn = {2040-3372},

year  = {2022},

date = {2022-06-01},

journal = {Nanoscale},

volume = {14},

number = {24},

pages = {8691--8708},

abstract = {The extracellular matrix (ECM) of articular cartilage is a three-dimensional network mainly constituted of entangled collagen fibrils and interfibrillar aggrecan aggregates. During the development of osteoarthritis (OA), the most common musculoskeletal disorder, the ECM is subjected to a combination of chemical and structural changes that play a pivotal role in the initiation and the progress of the disease. While the molecular mechanisms involved in the pathological remodelling of the ECM are considered as decisive, they remain, however, not completely elucidated. Herein, we report a relevant way for unravelling the role and nature of OA progress on human cartilage tissues, in terms of chemical composition and morphological and mechanical properties at the level of supramolecular assemblies constituting the cartilage ECM. For this purpose, we used X-ray photoelectron spectroscopy (XPS), and developed an innovative methodological approach that provides the molecular composition of the ECM. Moreover, we used atomic force microscopy (AFM) to probe the tissues at the level of individual collagen fibrils, both imaging and force spectroscopy modes being explored to this end. Taken together, these nanoscale characterization studies reveal the existence of two stages in the OA progress. At the early stage, a marked increase in the aggrecan and collagen content is observed, reflecting the homeostatic chondrocyte activity that tends to repair the cartilage ECM. At the late stage, we observe a failed attempt to stabilize and/or restore the tissue, yielding significant degradation of the supramolecular assemblies. This suggests an imbalance in the chondrocyte activity that turns in favor of catabolic events. Chemical changes are also accompanied by ECM structural changes and stiffening. Interestingly, we showed the possibility to mimic the imbalanced activities of chondrocytes by applying enzymatic digestions of healthy cartilage, through the combined action of hyaluronidase and collagenase. This yields damage strictly analogous to that observed at high OA severity. These findings bring mechanistic insights leading to a better understanding of the mechanism by which OA is initiated and progresses in the cartilage ECM. They offer guidelines for the development of curative treatments, such as targeting the homeostatic balance of chondrocyte metabolism through the control of enzymatic reactions involved in catabolic processes.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid34861543,

title = {Interactions of hydrophilic quantum dots with defect-free and defect containing supported lipid membranes},

author = {L Bar and F Perissinotto and L Redondo-Morata and M I Giannotti and J Goole and P Losada-Pérez},

doi = {10.1016/j.colsurfb.2021.112239},

issn = {1873-4367},

year  = {2022},

date = {2022-02-01},

journal = {Colloids Surf B Biointerfaces},

volume = {210},

pages = {112239},

abstract = {Quantum dots (QDs) are semiconductor nanoparticles with unique optical and electronic properties, whose interest as potential nano-theranostic platforms for imaging and sensing is increasing. The design and use of QDs requires the understanding of cell-nanoparticle interactions at a microscopic and nanoscale level. Model systems such as supported lipid bilayers (SLBs) are useful, less complex platforms mimicking physico-chemical properties of cell membranes. In this work, we investigated the effect of topographical homogeneity of SLBs bearing different surface charge in the adsorption of hydrophilic QDs. Using quartz-crystal microbalance, a label-free surface sensitive technique, we show significant differences in the interactions of QDs onto homogeneous and inhomogeneous SLBs formed following different strategies. Within short time scales, QDs adsorb onto topographically homogeneous, defect-free SLBs is driven by electrostatic interactions, leading to no layer disruption. After prolonged QD exposure, the nanomechanical stability of the SLB decreases suggesting nanoparticle insertion. In the case of inhomogeneous, defect containing layers, QDs target preferentially membrane defects, driven by a subtle interplay of electrostatic and entropic effects, inducing local vesicle rupture and QD insertion at membrane edges.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid35216412,

title = {Impact of Collagen Crosslinking on Dislocated Human Shoulder Capsules-Effect on Structural and Mechanical Properties},

author = {Pauline Cornette and Ilhem Lilia Jaabar and Vincent Dupres and Jean-David Werthel and Francis Berenbaum and Xavier Houard and Jessem Landoulsi and Geoffroy Nourissat},

doi = {10.3390/ijms23042297},

issn = {1422-0067},

year  = {2022},

date = {2022-02-01},

journal = {Int J Mol Sci},

volume = {23},

number = {4},

abstract = {Classical treatments of shoulder instability are associated with recurrence. To determine whether the modification of the capsule properties may be an alternative procedure, the effect of crosslinking treatment on the structure and mechanical properties of diseased human shoulder capsules was investigated. Joint capsules harvested from patients during shoulder surgery (n = 5) were treated or not with UV and/or riboflavin (0.1%, 1.0% and 2.5%). The structure and the mechanical properties of the capsules were determined by atomic force microscopy. The effect of treatments on cell death was investigated. Collagen fibrils were well-aligned and adjacent to each other with a D-periodicity of 66.9 ± 3.2 nm and a diameter of 71.8 ± 15.4 nm in control untreated capsules. No effect of treatments was observed on the organization of the collagen fibrils nor on their intrinsic characteristics, including D-periodicity or their mean diameter. The treatments also did not induce cell death. In contrast, UV + 2.5% riboflavin induced capsule stiffness, as revealed by the increased Young's modulus values ( < 0.0001 for each patient). Our results showed that the crosslinking procedure changed the biomechanics of diseased capsules, while keeping their structural organisation unchanged at the single fibril level. The UV/riboflavin crosslinking procedure may be a promising way to preserve the functions of collagen-based tissues and tune their elasticity for clinically relevant treatments.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid36111347,

title = {Surface tension of model tissues during malignant transformation and epithelial-mesenchymal transition},

author = {Irène Nagle and Alain Richert and Michael Quinteros and Sébastien Janel and Edgar Buysschaert and Nathalie Luciani and Henry Debost and Véronique Thevenet and Claire Wilhelm and Céline Prunier and Frank Lafont and Teresita Padilla-Benavides and Mathieu Boissan and Myriam Reffay},

doi = {10.3389/fcell.2022.926322},

issn = {2296-634X},

year  = {2022},

date = {2022-01-01},

journal = {Front Cell Dev Biol},

volume = {10},

pages = {926322},

abstract = {Epithelial-mesenchymal transition is associated with migration, invasion, and metastasis. The translation at the tissue scale of these changes has not yet been enlightened while being essential in the understanding of tumor progression. Thus, biophysical tools dedicated to measurements on model tumor systems are needed to reveal the impact of epithelial-mesenchymal transition at the collective cell scale. Herein, using an original biophysical approach based on magnetic nanoparticle insertion inside cells, we formed and flattened multicellular aggregates to explore the consequences of the loss of the metastasis suppressor NME1 on the mechanical properties at the tissue scale. Multicellular spheroids behave as viscoelastic fluids, and their equilibrium shape is driven by surface tension as measured by their deformation upon magnetic field application. In a model of breast tumor cells genetically modified for NME1, we correlated tumor invasion, migration, and adhesion modifications with shape maintenance properties by measuring surface tension and exploring both invasive and migratory potential as well as adhesion characteristics.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid35101742,

title = {Modulation of designer biomimetic matrices for optimized differentiated intestinal epithelial cultures},

author = {Wang Xi and Jad Saleh and Ayako Yamada and Caterina Tomba and Barbara Mercier and Sébastien Janel and Tien Dang and Matis Soleilhac and Aurélie Djemat and Huiqiong Wu and Béatrice Romagnolo and Frank Lafont and René-Marc Mège and Yong Chen and Delphine Delacour},

doi = {10.1016/j.biomaterials.2022.121380},

issn = {1878-5905},

year  = {2022},

date = {2022-01-01},

journal = {Biomaterials},

volume = {282},

pages = {121380},

abstract = {The field of intestinal biology is thirstily searching for different culture methods that complement the limitations of organoids, particularly the lack of a differentiated intestinal compartment. While being recognized as an important milestone for basic and translational biological studies, many primary cultures of intestinal epithelium (IE) rely on empirical trials using hydrogels of various stiffness, whose mechanical impact on epithelial organization remains vague until now. Here, we report the development of hydrogel scaffolds with a range of elasticities and their influence on IE expansion, organization, and differentiation. On stiff substrates (>5 kPa), mouse IE cells adopt a flat cell shape and detach in the short-term. In contrast, on soft substrates (80-500 Pa), they sustain for a long-term, pack into high density, develop columnar shape with improved apical-basal polarity and differentiation marker expression, a phenotype reminiscent of features in vivo mouse IE. We then developed a soft gel molding process to produce 3D Matrigel scaffolds of close-to-nature stiffness, which support and maintain a culture of mouse IE into crypt-villus architecture. Thus, the present work is up-to-date informative for the design of biomaterials for ex vivo intestinal models, offering self-renewal in vitro culture that emulates the mouse IE.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid34878112,

title = {DHA-containing phospholipids control membrane fusion and transcellular tunnel dynamics},

author = {Meng-Chen Tsai and Lucile Fleuriot and Sébastien Janel and David Gonzalez-Rodriguez and Camille Morel and Amel Mettouchi and Delphine Debayle and Stéphane Dallongeville and Jean-Christophe Olivo-Marin and Bruno Antonny and Frank Lafont and Emmanuel Lemichez and Hélène Barelli},

doi = {10.1242/jcs.259119},

issn = {1477-9137},

year  = {2022},

date = {2022-01-01},

journal = {J Cell Sci},

volume = {135},

number = {5},

abstract = {Metabolic studies and animal knockout models point to the critical role of polyunsaturated docosahexaenoic acid (22:6, DHA)-containing phospholipids (DHA-PLs) in physiology. Here, we investigated the impact of DHA-PLs on the dynamics of transendothelial cell macroapertures (TEMs) triggered by RhoA inhibition-associated cell spreading. Lipidomic analyses showed that human umbilical vein endothelial cells (HUVECs) subjected to a DHA diet undergo a 6-fold enrichment in DHA-PLs at the plasma membrane (PM) at the expense of monounsaturated oleic acid-containing PLs (OA-PLs). Consequently, DHA-PL enrichment at the PM induces a reduction in cell thickness and shifts cellular membranes towards a permissive mode of membrane fusion for transcellular tunnel initiation. We provide evidence that a global homeostatic control of membrane tension and cell cortex rigidity minimizes overall changes of TEM area through a decrease of TEM size and lifetime. Conversely, low DHA-PL levels at the PM lead to the opening of unstable and wider TEMs. Together, this provides evidence that variations of DHA-PL levels in membranes affect cell biomechanical properties.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid34747313,

title = {A noncanonical autophagy is involved in the transfer of -microvesicles to astrocytes},

author = {Inès Leleu and Delphine Genete and Sophie Salomé Desnoulez and Nasreddine Saidi and Priscille Brodin and Frank Lafont and Stanislas Tomavo and Sylviane Pied},

doi = {10.1080/15548627.2021.1993704},

issn = {1554-8635},

year  = {2022},

date = {2022-01-01},

journal = {Autophagy},

volume = {18},

number = {7},

pages = {1583--1598},

abstract = {Cerebral malaria is a neuroinflammatory disease induced by  infection. In animal models, the neuro-pathophysiology of cerebral malaria results from the sequestration of infected red blood cells (iRBCs) in microvessels that promotes the activation of glial cells in the brain. This activation provokes an exacerbated inflammatory response characterized by the secretion of proinflammatory cytokines and chemokines, leading to brain infiltration by pathogenic CD8 T lymphocytes. Astrocytes are a major subtype of brain glial cells that play an important role in maintaining the homeostasis of the central nervous system, the integrity of the brain-blood barrier and in mounting local innate immune responses. We have previously shown that parasitic microvesicles (A-MVs) are transferred from iRBCs to astrocytes. The present study shows that an unconventional LC3-mediated autophagy pathway independent of ULK1 is involved in the transfer and degradation of A-MVs inside the astrocytes. We further demonstrate that inhibition of the autophagy process by treatment with 3-methyladenine blocks the transfer of A-MVs, which remain localized in the astrocytic cell membrane and are not internalized. Moreover, bafilomycin A, another drug against autophagy promotes the accumulation of A-MVs inside the astrocytes by inhibiting the fusion with lysosomes, and prevents ECM in mice infected with A. Finally, we establish that RUBCN/rubicon or ATG5 silencing impede astrocyte production in CCL2 and CXCL10 chemokines induced by A stimulation. Altogether, our data suggest that a non-canonical autophagy-lysosomal pathway may play a key role in cerebral malaria through regulation of brain neuro-inflammation by astrocytes.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid34998435,

title = {The Alzheimer susceptibility gene BIN1 induces isoform-dependent neurotoxicity through early endosome defects},

author = {Erwan Lambert and Orthis Saha and Bruna Soares Landeira and Ana Raquel Melo de Farias and Xavier Hermant and Arnaud Carrier and Alexandre Pelletier and Johanna Gadaut and Lindsay Davoine and Cloé Dupont and Philippe Amouyel and Amélie Bonnefond and Frank Lafont and Farida Abdelfettah and Patrik Verstreken and Julien Chapuis and Nicolas Barois and Fabien Delahaye and Bart Dermaut and Jean-Charles Lambert and Marcos R Costa and Pierre Dourlen},

doi = {10.1186/s40478-021-01285-5},

issn = {2051-5960},

year  = {2022},

date = {2022-01-01},

journal = {Acta Neuropathol Commun},

volume = {10},

number = {1},

pages = {4},

abstract = {The Bridging Integrator 1 (BIN1) gene is a major susceptibility gene for Alzheimer's disease (AD). Deciphering its pathophysiological role is challenging due to its numerous isoforms. Here we observed in Drosophila that human BIN1 isoform1 (BIN1iso1) overexpression, contrary to human BIN1 isoform8 (BIN1iso8) and human BIN1 isoform9 (BIN1iso9), induced an accumulation of endosomal vesicles and neurodegeneration. Systematic search for endosome regulators able to prevent BIN1iso1-induced neurodegeneration indicated that a defect at the early endosome level is responsible for the neurodegeneration. In human induced neurons (hiNs) and cerebral organoids, BIN1 knock-out resulted in the narrowing of early endosomes. This phenotype was rescued by BIN1iso1 but not BIN1iso9 expression. Finally, BIN1iso1 overexpression also led to an increase in the size of early endosomes and neurodegeneration in hiNs. Altogether, our data demonstrate that the AD susceptibility gene BIN1, and especially BIN1iso1, contributes to early-endosome size deregulation, which is an early pathophysiological hallmark of AD pathology.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{10.3389/fphy.2022.1052203,

title = {Rheological comparison between control and Dupuytren fibroblasts when plated in circular micropatterns using atomic force microscopy},

author = {Sandra Pérez-Domínguez and Elisabeth Werkmeister and Maria Luisa Marini and Vincent Dupres and Sébastien Janel and Frank Lafont and Manfred Radmacher},

url = {https://www.frontiersin.org/articles/10.3389/fphy.2022.1052203},

doi = {10.3389/fphy.2022.1052203},

issn = {2296-424X},

year  = {2022},

date = {2022-01-01},

journal = {Frontiers in Physics},

volume = {10},

abstract = {In tissue, cells are obliged to confine and adapt to a specific geometric shape due to the surrounding environmental constraints. Under healthy conditions, fibroblasts present an elongated shape; however, changes in biochemical and physical properties of the extracellular matrix could distort the cell shape, inducing a pathological state. We have studied fibroblasts’ mechanical behavior under circular geometrical constraints. Circular micropatterns force fibroblasts to acquire a different shape from that of a healthy tissue, inducing a possible pathological condition. In total, three different fibroblast types from Dupuytren’s disorder, all obtained from the same patient, were confined in circular-shaped micropatterns of three different diameters (25, 35, and 45 µm), and mechanical properties were evaluated using an atomic force microscope (AFM). We found that control fibroblast mechanics (apparent Young’s modulus) increases with the increasing pattern diameter and comes together with a decrease in cell height and in loss tangent, translated into a more solid-like behavior. We hypothesize that these results resemble the transition toward the myofibroblast phenotype, ameliorating cytoskeleton formation and organization and enhancing cell contraction. Scar and Dupuytren fibroblasts did not display major changes in cell mechanics and cell height when changing the pattern diameter, suggesting that they are less affected by physical changes in the environment as they can adapt their shape to the geometrical dimensions. Therefore, our findings demonstrate that combining micropatterning and AFM measurements provides a powerful tool to study cell mechanics inducing constraints onto the cell, thus mimicking certain aspects of the tissue environment in both healthy and pathological states.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid33779491b,

title = {Persistence and dynamics of fluorescent Lactobacillus plantarum in the healthy versus inflamed gut},

author = {Sophie Salomé-Desnoulez and Sabine Poiret and Benoit Foligné and Ghaffar Muharram and Véronique Peucelle and Frank Lafont and Catherine Daniel},

doi = {10.1080/19490976.2021.1897374},

issn = {1949-0984},

year  = {2021},

date = {2021-12-13},

urldate = {2021-12-13},

journal = {Gut Microbes},

volume = {13},

number = {1},

pages = {1--16},

abstract = {The gastrointestinal tract is the main ecological niche in which  strains may provide health benefits in mammals. There is currently a need to characterize host-microbe interactions in space and time by tracking these bacteria . We combined noninvasive whole-body imaging with  fluorescence confocal microscopy imaging to monitor the impact of intestinal inflammation on the persistence of orally administered  NCIMB8826 in healthy and inflamed mouse colons. We developed fluorescent  strains and demonstrated that mCherry is the best system for  imaging and  fluorescence confocal microscopy of these bacteria. We also used whole-body imaging to show that this anti-inflammatory, orally administered strain persists for longer and at higher counts in the inflamed colon than in the healthy colon. We confirmed these results by the  confocal imaging of colons from mice with experimental colitis for 3 days after induction. Moreover, extended orthogonal view projections enabled us to localize individual  in sites that differed for healthy  inflamed guts. In healthy colons, orally administered bacteria were localized in the lumen (in close contact with commensal bacteria) and sometimes in the crypts (albeit very rarely in contact with intestinal cells). The bacteria were observed within and outside the mucus layer. In contrast,  bacteria in the inflamed colon were mostly located in the lumen and (in less inflamed areas) within the mucus layer. In more intensely inflamed areas (i.e., where the colon had undergone structural damage), the  were in direct contact with damaged epithelial cells. Taken as a whole, our results show that fluorescently labeled  can be used to study the persistence of these bacteria in inflamed guts using both noninvasive whole-body imaging and  fluorescence confocal microscopy.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid34576719,

title = {Adherent-Invasive and Non-Invasive  Isolates Differ in Their Effects on  Lifespan},

author = {Maria Beatriz de Sousa Figueiredo and Elizabeth Pradel and Fanny George and Séverine Mahieux and Isabelle Houcke and Muriel Pottier and Chantal Fradin and Christel Neut and Catherine Daniel and Antonino Bongiovanni and Benoît Foligné and Marie Titécat},

doi = {10.3390/microorganisms9091823},

issn = {2076-2607},

year  = {2021},

date = {2021-08-01},

journal = {Microorganisms},

volume = {9},

number = {9},

abstract = {The adherent-invasive  (AIEC) pathotype has been implicated in the pathogenesis of inflammatory bowel diseases in general and in Crohn's disease (CD) in particular. AIEC strains are primarily characterized by their ability to adhere to and invade intestinal epithelial cells. However, the genetic and phenotypic features of AIEC isolates vary greatly as a function of the strain's clonality, host factors, and the gut microenvironment. It is thus essential to identify the determinants of AIEC pathogenicity and understand their role in intestinal epithelial barrier dysfunction and inflammation. We reasoned that soil nematode  (a simple but powerful model of host-bacterium interactions) could be used to study the virulence of AIEC vs. non- AIEC  strains. Indeed, we found that the colonization of  (strain N2) by  impacted survival in a strain-specific manner. Moreover, the AIEC strains' ability to invade cells in vitro was linked to the median lifespan in  (strain PX627). However, neither the  intrinsic invasiveness (i.e., the fact for an individual strain to be characterized as invasive or not) nor AIEC's virulence levels (i.e., the intensity of invasion, established in % from the infectious inoculum) in intestinal epithelial cells was correlated with ' lifespan in the killing assay. Nevertheless, AIEC longevity of  might be a relevant model for screening anti-adhesion drugs and anti-invasive probiotics.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid33671764,

title = {Assessment of Pb(II), Cd(II), and Al(III) Removal Capacity of Bacteria from Food and Gut Ecological Niches: Insights into Biodiversity to Limit Intestinal Biodisponibility of Toxic Metals},

author = {Fanny George and Séverine Mahieux and Catherine Daniel and Marie Titécat and Nicolas Beauval and Isabelle Houcke and Christel Neut and Delphine Allorge and Frédéric Borges and Gwénaël Jan and Benoît Foligné and Anne Garat},

doi = {10.3390/microorganisms9020456},

issn = {2076-2607},

year  = {2021},

date = {2021-02-01},

journal = {Microorganisms},

volume = {9},

number = {2},

abstract = {Toxic metals (such as lead, cadmium, and, to a lesser extent, aluminum) are detrimental to health when ingested in food or water or when inhaled. By interacting with heavy metals, gut and food-derived microbes can actively and/or passively modulate (by adsorption and/or sequestration) the bioavailability of these toxins inside the gut. This "intestinal bioremediation" involves the selection of safe microbes specifically able to immobilize metals. We used inductively coupled plasma mass spectrometry to investigate the in vitro ability of 225 bacteria to remove the potentially harmful trace elements lead, cadmium, and aluminum. Interspecies and intraspecies comparisons were performed among the Firmicutes (mostly lactic acid bacteria, including  spp., with some , , and  representatives), Actinobacteria, and Proteobacteria. The removal of a mixture of lead and cadmium was also investigated. Although the objective of the study was not to elucidate the mechanisms of heavy metal removal for each strain and each metal, we nevertheless identified promising candidate bacteria as probiotics for the intestinal bioremediation of Pb(II) and Cd(II).},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid33557275,

title = {Comparative Analysis of Hepatitis C Virus NS5A Dynamics and Localization in Assembly-Deficient Mutants},

author = {Laura Riva and Corentin Spriet and Nicolas Barois and Costin-Ioan Popescu and Jean Dubuisson and Yves Rouillé},

doi = {10.3390/pathogens10020172},

issn = {2076-0817},

year  = {2021},

date = {2021-02-01},

journal = {Pathogens},

volume = {10},

number = {2},

abstract = {The hepatitis C virus (HCV) life cycle is a tightly regulated process, during which structural and non-structural proteins cooperate. However, the interplay between HCV proteins during genomic RNA replication and progeny virion assembly is not completely understood. Here, we studied the dynamics and intracellular localization of non-structural 5A protein (NS5A), which is a protein involved both in genome replication and encapsidation. An NS5A-eGFP (enhanced green fluorescent protein) tagged version of the strain JFH-1-derived wild-type HCV was compared to the corresponding assembly-deficient viruses Δcore, NS5A basic cluster 352-533 mutant (BCM), and serine cluster 451 + 454 + 457 mutant (SC). These analyses highlighted an increase of NS5A motility when the viral protein core was lacking. Although to a lesser extent, NS5A motility was also increased in the BCM virus, which is characterized by a lack of interaction of NS5A with the viral RNA, impairing HCV genome encapsidation. This observation suggests that the more static NS5A population is mainly involved in viral assembly rather than in RNA replication. Finally, NS4B exhibited a reduced co-localization with NS5A and lipid droplets for both Δcore and SC mutants, which is characterized by the absence of interaction of NS5A with core. This observation strongly suggests that NS5A is involved in targeting NS4B to lipid droplets (LDs). In summary, this work contributes to a better understanding of the interplay between HCV proteins during the viral life cycle.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid33414462,

title = {TgAP2IX-5 is a key transcriptional regulator of the asexual cell cycle division in Toxoplasma gondii},

author = {Asma S Khelifa and Cecilia Guillen Sanchez and Kevin M Lesage and Ludovic Huot and Thomas Mouveaux and Pierre Pericard and Nicolas Barois and Helene Touzet and Guillemette Marot and Emmanuel Roger and Mathieu Gissot},

doi = {10.1038/s41467-020-20216-x},

issn = {2041-1723},

year  = {2021},

date = {2021-01-01},

journal = {Nat Commun},

volume = {12},

number = {1},

pages = {116},

abstract = {Apicomplexan parasites have evolved efficient and distinctive strategies for intracellular replication where the timing of emergence of the daughter cells (budding) is a decisive element. However, the molecular mechanisms that provide the proper timing of parasite budding remain unknown. Using Toxoplasma gondii as a model Apicomplexan, we identified a master regulator that controls the timing of the budding process. We show that an ApiAP2 transcription factor, TgAP2IX-5, controls cell cycle events downstream of centrosome duplication. TgAP2IX-5 binds to the promoter of hundreds of genes and controls the activation of the budding-specific cell cycle expression program. TgAP2IX-5 regulates the expression of specific transcription factors that are necessary for the completion of the budding cycle. Moreover, TgAP2IX-5 acts as a limiting factor that ensures that asexual proliferation continues by promoting the inhibition of the differentiation pathway. Therefore, TgAP2IX-5 is a master regulator that controls both cell cycle and developmental pathways.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid33100165,

title = {Biological physics by high-speed atomic force microscopy},

author = {Ignacio Casuso and Lorena Redondo-Morata and Felix Rico},

doi = {10.1098/rsta.2019.0604},

issn = {1471-2962},

year  = {2020},

date = {2020-12-01},

journal = {Philos Trans A Math Phys Eng Sci},

volume = {378},

number = {2186},

pages = {20190604},

abstract = {While many fields have contributed to biological physics, nanotechnology offers a new scale of observation. High-speed atomic force microscopy (HS-AFM) provides nanometre structural information and dynamics with subsecond resolution of biological systems. Moreover, HS-AFM allows us to measure piconewton forces within microseconds giving access to unexplored, fast biophysical processes. Thus, HS-AFM provides a tool to nourish biological physics through the observation of emergent physical phenomena in biological systems. In this review, we present an overview of the contribution of HS-AFM, both in imaging and force spectroscopy modes, to the field of biological physics. We focus on examples in which HS-AFM observations on membrane remodelling, molecular motors or the unfolding of proteins have stimulated the development of novel theories or the emergence of new concepts. We finally provide expected applications and developments of HS-AFM that we believe will continue contributing to our understanding of nature, by serving to the dialogue between biology and physics. This article is part of a discussion meeting issue 'Dynamic  microscopy relating structure and function'.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid32398681,

title = {Galectin-3 modulates epithelial cell adaptation to stress at the ER-mitochondria interface},

author = {Lucie Coppin and Arnaud Jannin and Emilie Ait Yahya and Caroline Thuillier and Céline Villenet and Meryem Tardivel and Antonino Bongiovanni and Cécile Gaston and Simon de Beco and Nicolas Barois and Isabelle van Seuningen and Emmanuelle Durand and Amélie Bonnefond and Jean-Claude Vienne and Joseph Vamecq and Martin Figeac and Audrey Vincent and Delphine Delacour and Nicole Porchet and Pascal Pigny},

doi = {10.1038/s41419-020-2556-3},

issn = {2041-4889},

year  = {2020},

date = {2020-05-01},

journal = {Cell Death Dis},

volume = {11},

number = {5},

pages = {360},

abstract = {Cellular stress response contributes to epithelial defense in adaptation to environment changes. Galectins play a pivotal role in the regulation of this response in malignant cells. However, precise underlying mechanisms are largely unknown. Here we demonstrate that Galectin-3, a pro and anti-apoptotic lectin, is required for setting up a correct cellular response to stress by orchestrating several effects. First, Galectin-3 constitutes a key post-transcriptional regulator of stress-related mRNA regulons coordinating the cell metabolism, the mTORC1 complex or the unfolded protein response (UPR). Moreover, we demonstrated the presence of Galectin-3 with mitochondria-associated membranes (MAM), and its interaction with proteins located at the ER or mitochondrial membranes. There Galectin-3 prevents the activation and recruitment at the mitochondria of the regulator of mitochondria fission DRP-1. Accordingly, loss of Galectin-3 impairs mitochondrial morphology, with more fragmented and round mitochondria, and dynamics both in normal and cancer epithelial cells in basal conditions. Importantly, Galectin-3 deficient cells also display changes of the activity of the mitochondrial respiratory chain complexes, of the mTORC1/S6RP/4EBP1 translation pathway and reactive oxygen species levels. Regarding the ER, Galectin-3 did not modify the activities of the 3 branches of the UPR in basal conditions. However, Galectin-3 favours an adaptative UPR following ER stress induction by Thapsigargin treatment. Altogether, at the ER-mitochondria interface, Galectin-3 coordinates the functioning of the ER and mitochondria, preserves the integrity of mitochondrial network and modulates the ER stress response.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid32294143,

title = {A refined model of how Yersinia pestis produces a transmissible infection in its flea vector},

author = {Amélie Dewitte and Typhanie Bouvenot and François Pierre and Isabelle Ricard and Elizabeth Pradel and Nicolas Barois and Anaïs Hujeux and Sébastien Bontemps-Gallo and Florent Sebbane},

doi = {10.1371/journal.ppat.1008440},

issn = {1553-7374},

year  = {2020},

date = {2020-04-01},

journal = {PLoS Pathog},

volume = {16},

number = {4},

pages = {e1008440},

abstract = {In flea-borne plague, blockage of the flea's foregut by Yersinia pestis hastens transmission to the mammalian host. Based on microscopy observations, we first suggest that flea blockage results from primary infection of the foregut and not from midgut colonization. In this model, flea infection is characterized by the recurrent production of a mass that fills the lumen of the proventriculus and encompasses a large number of Y. pestis. This recurrence phase ends when the proventricular cast is hard enough to block blood ingestion. We further showed that ymt (known to be essential for flea infection) is crucial for cast production, whereas the hmsHFRS operon (known to be essential for the formation of the biofilm that blocks the gut) is needed for cast consolidation. By screening a library of mutants (each lacking a locus previously known to be upregulated in the flea gut) for biofilm formation, we found that rpiA is important for flea blockage but not for colonization of the midgut. This locus may initially be required to resist toxic compounds within the proventricular cast. However, once the bacterium has adapted to the flea, rpiA helps to form the biofilm that consolidates the proventricular cast. Lastly, we used genetic techniques to demonstrate that ribose-5-phosphate isomerase activity (due to the recent gain of a second copy of rpiA (y2892)) accentuated blockage but not midgut colonization. It is noteworthy that rpiA is an ancestral gene, hmsHFRS and rpiA2 were acquired by the recent ancestor of Y. pestis, and ymt was acquired by Y. pestis itself. Our present results (i) highlight the physiopathological and molecular mechanisms leading to flea blockage, (ii) show that the role of a gene like rpiA changes in space and in time during an infection, and (iii) emphasize that evolution is a gradual process punctuated by sudden jumps.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid32463830,

title = {Rab11A regulates dense granule transport and secretion during Toxoplasma gondii invasion of host cells and parasite replication},

author = {Kannan Venugopal and Sylia Chehade and Elisabeth Werkmeister and Nicolas Barois and Javier Periz and Frank Lafont and Isabelle Tardieux and Jamal Khalife and Gordon Langsley and Markus Meissner and Sabrina Marion},

doi = {10.1371/journal.ppat.1008106},

issn = {1553-7374},

year  = {2020},

date = {2020-01-01},

journal = {PLoS Pathog},

volume = {16},

number = {5},

pages = {e1008106},

abstract = {Toxoplasma gondii possesses an armada of secreted virulent factors that enable parasite invasion and survival into host cells. These factors are contained in specific secretory organelles, the rhoptries, micronemes and dense granules that release their content upon host cell recognition. Dense granules are secreted in a constitutive manner during parasite replication and play a crucial role in modulating host metabolic and immune responses. While the molecular mechanisms triggering rhoptry and microneme release upon host cell adhesion have been well studied, constitutive secretion remains a poorly explored aspect of T. gondii vesicular trafficking. Here, we investigated the role of the small GTPase Rab11A, a known regulator of exocytosis in eukaryotic cells. Our data revealed an essential role of Rab11A in promoting the cytoskeleton driven transport of dense granules and the release of their content into the vacuolar space. Rab11A also regulates transmembrane protein trafficking and localization during parasite replication, indicating a broader role of Rab11A in cargo exocytosis at the plasma membrane. Moreover, we found that Rab11A also regulates extracellular parasite motility and adhesion to host cells. In line with these findings, MIC2 secretion was altered in Rab11A-defective parasites, which also exhibited severe morphological defects. Strikingly, by live imaging we observed a polarized accumulation of Rab11A-positive vesicles and dense granules at the apical pole of extracellular motile and invading parasites suggesting that apically polarized Rab11A-dependent delivery of cargo regulates early secretory events during parasite entry into host cells.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid32729971,

title = {High-dose dietary supplementation with zinc prevents gut inflammation: Investigation of the role of metallothioneins and beyond by transcriptomic and metagenomic studies},

author = {Benoît Foligné and Fanny George and Annie Standaert and Anne Garat and Sabine Poiret and Véronique Peucelle and Stéphanie Ferreira and Hélène Sobry and Ghaffar Muharram and Anca Lucau-Danila and Catherine Daniel},

doi = {10.1096/fj.202000562RR},

issn = {1530-6860},

year  = {2020},

date = {2020-01-01},

journal = {FASEB J},

volume = {34},

number = {9},

pages = {12615--12633},

abstract = {Although it is known that zinc has several beneficial roles in the context of gut inflammation, the underlying mechanisms have not been extensively characterized. Zinc (Zn) is known to be the primary physiological inducer of the expression of the metallothionein (MT) superfamily of small stress-responsive proteins. The expression of MTs in various tissues is induced or enhanced (including the gastrointestinal tract (GIT)) by a variety of stimuli, including infection and inflammation. However, the MTs' exact role in inflammation is still subject to debate. In order to establish whether or not MTs are the sole vectors in the Zn-based modulation of intestinal inflammation, we used transcriptomic and metagenomic approaches to assess the potential effect of dietary Zn, the mechanisms underlying the MTs' beneficial effects, and the induction of previously unidentified mediators. We found that the expression of endogenous MTs in the mouse GIT was stimulated by an optimized dietary supplementation with Zn. The protective effects of dietary supplementation with Zn were then evaluated in mouse models of chemically induced colitis. The potential contribution of MTs and other pathways was explored via transcriptomic analyses of the ileum and colon in Zn-treated mice. The microbiota's role was also assessed via fecal 16S rRNA sequencing. We found that high-dose dietary supplementation with Zn induced the expression of MT-encoding genes in the colon of healthy mice. We next demonstrated that the Zn diet significantly protected mice in the two models of induced colitis. When comparing Zn-treated and control mice, various genes were found to be differentially expressed in the colon and the ileum. Finally, we found that Zn supplementation did not modify the overall structure of the fecal microbiota, with the exception of (i) a significant increase in endogenous Clostridiaceae, and (ii) some subtle but specific changes at the family and genus levels. Our results emphasize the beneficial effects of excess dietary Zn on the prevention of colitis and inflammatory events in mouse models. The main underlying mechanisms were driven by the multifaceted roles of MTs and the other potential molecular mediators highlighted by our transcriptomic analyses although we cannot rule out contributions by other factors from the host and/or the microbiota.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid33837691,

title = {Lipid bilayers: Phase behavior and nanomechanics},

author = {Lorena Redondo-Morata and Patricia Losada-Pérez and Marina Inés Giannotti},

doi = {10.1016/bs.ctm.2020.08.005},

issn = {1063-5823},

year  = {2020},

date = {2020-01-01},

journal = {Curr Top Membr},

volume = {86},

pages = {1--55},

abstract = {Lipid membranes are involved in many physiological processes like recognition, signaling, fusion or remodeling of the cell membrane or some of its internal compartments. Within the cell, they are the ultimate barrier, while maintaining the fluidity or flexibility required for a myriad of processes, including membrane protein assembly. The physical properties of in vitro model membranes as model cell membranes have been extensively studied with a variety of techniques, from classical thermodynamics to advanced modern microscopies. Here we review the nanomechanics of solid-supported lipid membranes with a focus in their phase behavior. Relevant information obtained by quartz crystal microbalance with dissipation monitoring (QCM-D) and atomic force microscopy (AFM) as complementary techniques in the nano/mesoscale interface is presented. Membrane morphological and mechanical characterization will be discussed in the framework of its phase behavior, phase transitions and coexistence, in simple and complex models, and upon the presence of cholesterol.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid31710810,

title = {Hierarchical Collagen-Hydroxyapatite Nanostructures Designed through Layer-by-Layer Assembly of Crystal-Decorated Fibrils},

author = {Elodie Colaço and Dalil Brouri and Nesrine Aissaoui and Pauline Cornette and Vincent Dupres and Rute F Domingos and Jean-François Lambert and Emmanuel Maisonhaute and Karim El Kirat and Jessem Landoulsi},

doi = {10.1021/acs.biomac.9b01299},

issn = {1526-4602},

year  = {2019},

date = {2019-12-01},

journal = {Biomacromolecules},

volume = {20},

number = {12},

pages = {4522--4534},

abstract = {A comprehensive understanding of the mechanism by which type I collagen (Col) interacts with hydroxyapatite nanoparticles (Hap NPs) in aqueous solutions is a pivotal step for guiding the design of biologically relevant nanocomposites with controlled hierarchical structure. In this paper we use a variety of Hap NPs differing by their shape (rod vs platelet) and their size (∼30 vs ∼130 nm) and investigate their mechanism(s) of interaction with collagen. The addition of collagen to the Hap suspensions induces different effects that strongly depend on the nanoparticle type. Interestingly, the use of small rods, typically with ∼30 nm of length (), leads to the formation of assembled collagen fibrils decorated with Hap nanocrystals which, in turn, self-assemble progressively to form larger fibrillar Hap-Col composite. The crystals decorating collagen provide "intrinsic" negative charges to the fibrillar objects that allow their incorporation in three-dimensional structure using layer-by-layer (LbL) assembly. This offers a straightforward way to construct a collagen-based hybrid material with well-defined hierarchy under near-physiological conditions. In situ, QCM-D monitoring revealed the buildup of soft and highly hydrated hybrid (PAH/-Col) multilayers for which the mechanism of growth was very different from that observed for polyelectrolytes and nanoparticles without collagen (PAH/). The LbL assembly of crystal-decorated collagen yields a hierarchical nanostructured film whose thickness and roughness can be modulated by the addition of salt and incorporate fibrillar objects of about 400 nm in width and few micrometers in length, as probed by AFM. The approach described in this work provides a relevant way to better control the (supra)molecular assembly of Col and Hap NPs with the perspective of developing hierarchical Hap-Col nanocomposites with tuned properties for various biomedical applications.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid31106790,

title = {Stiffness tomography of eukaryotic intracellular compartments by atomic force microscopy},

author = {Sébastien Janel and Michka Popoff and Nicolas Barois and Elisabeth Werkmeister and Séverine Divoux and Franck Perez and Frank Lafont},

doi = {10.1039/c8nr08955h},

issn = {2040-3372},

year  = {2019},

date = {2019-05-01},

journal = {Nanoscale},

volume = {11},

number = {21},

pages = {10320--10328},

abstract = {Precise localization and biophysical characterization of cellular structures is a key to the understanding of biological processes happening both inside the cell and at the cell surface. Atomic force microscopy is a powerful tool to study the cell surface - topography, elasticity, viscosity, interactions - and also the viscoelastic behavior of the underlying cytoplasm, cytoskeleton or the nucleus. Here, we demonstrate the ability of atomic force microscopy to also map and characterize organelles and microorganisms inside cells, at the nanoscale, by combining stiffness tomography with super-resolution fluorescence and electron microscopy. By using this correlative approach, we could both identify and characterize intracellular compartments. The validation of this approach was performed by monitoring the stiffening effect according to the metabolic status of the mitochondria in living cells in real-time.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid30552790b,

title = {The puzzling construction of the conidial outer layer of Aspergillus fumigatus},

author = {Isabel Valsecchi and Vincent Dupres and Jean-Philippe Michel and Magalie Duchateau and Mariette Matondo and Georgios Chamilos and Cosmin Saveanu and J Iñaki Guijarro and Vishukumar Aimanianda and Frank Lafont and Jean-Paul Latgé and Anne Beauvais},

doi = {10.1111/cmi.12994},

issn = {1462-5822},

year  = {2019},

date = {2019-05-01},

journal = {Cell Microbiol},

volume = {21},

number = {5},

pages = {e12994},

abstract = {If the mycelium of Aspergillus fumigatus is very short-lived in the laboratory, conidia can survive for years. This survival capacity and extreme resistance to environmental insults is a major biological characteristic of this fungal species. Moreover, conidia, which easily reach the host alveola, are the infective propagules. Earlier studies have shown the role of some molecules of the outer conidial layer in protecting the fungus against the host defense. The outer layer of the conidial cell wall, directly in contact with the host cells, consists of α-(1,3)-glucan, melanin, and proteinaceous rodlets. This study is focused on the global importance of this outer layer. Single and multiple mutants without one to three major components of the outer layer were constructed and studied. The results showed that the absence of the target molecules resulting from multiple gene deletions led to unexpected phenotypes without any logical additivity. Unexpected compensatory cell wall surface modifications were indeed observed, such as the synthesis of the mycelial virulence factor galactosaminogalactan, the increase in chitin and glycoprotein concentration or particular changes in permeability. However, sensitivity of the multiple mutants to killing by phagocytic host cells confirmed the major importance of melanin in protecting conidia.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid31118478b,

title = {Development of a novel multiphysical approach for the characterization of mechanical properties of musculotendinous tissues},

author = {Malek Kammoun and Redouane Ternifi and Vincent Dupres and Philippe Pouletaut and Sandra Même and William Même and Frederic Szeremeta and Jessem Landoulsi and Jean-Marc Constans and Frank Lafont and Malayannan Subramaniam and John R Hawse and Sabine F Bensamoun},

doi = {10.1038/s41598-019-44053-1},

issn = {2045-2322},

year  = {2019},

date = {2019-05-01},

journal = {Sci Rep},

volume = {9},

number = {1},

pages = {7733},

abstract = {At present, there is a lack of well-validated protocols that allow for the analysis of the mechanical properties of muscle and tendon tissues. Further, there are no reports regarding characterization of mouse skeletal muscle and tendon mechanical properties in vivo using elastography thereby limiting the ability to monitor changes in these tissues during disease progression or response to therapy. Therefore, we sought to develop novel protocols for the characterization of mechanical properties in musculotendinous tissues using atomic force microscopy (AFM) and ultrasound elastography. Given that TIEG1 knockout (KO) mice exhibit well characterized defects in the mechanical properties of skeletal muscle and tendon tissue, we have chosen to use this model system in the present study. Using TIEG1 knockout and wild-type mice, we have devised an AFM protocol that does not rely on the use of glue or chemical agents for muscle and tendon fiber immobilization during acquisition of transversal cartographies of elasticity and topography. Additionally, since AFM cannot be employed on live animals, we have also developed an ultrasound elastography protocol using a new linear transducer, SLH20-6 (resolution: 38 µm, footprint: 2.38 cm), to characterize the musculotendinous system in vivo. This protocol allows for the identification of changes in muscle and tendon elasticities. Such innovative technological approaches have no equivalent to date, promise to accelerate our understanding of musculotendinous mechanical properties and have numerous research and clinical applications.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid30680759,

title = {Blocking bacterial entry at the adhesion step reveals dynamic recruitment of membrane and cytosolic probes},

author = {Yann Ciczora and Sébastien Janel and Magali Soyer and Michka Popoff and Elisabeth Werkmeister and Frank Lafont},

doi = {10.1111/boc.201800070},

issn = {1768-322X},

year  = {2019},

date = {2019-03-01},

journal = {Biol Cell},

volume = {111},

number = {3},

pages = {67--77},

abstract = {BACKGROUND: Bacterial invasion covers two steps: adhesion and entry per se. The cell signalling response is triggered upon pathogen interaction at the cell surface. This response continues when the pathogen is internalised. It is likely that these two steps activate different molecular machineries. So far, it has not been possible to easily follow in physiological conditions these events separately. We thus developed an approach to uncouple adhesion from entry using atomic force microscopy (AFM)-driven force and fluorescence measurements.



RESULTS: We report nanometric-scale, high-resolution, functional dynamic measurements of bacterial interaction with the host cell surface using photonic and adhesion force analyses. We describe how to achieve a precise monitoring of iterative cell-bacterium interactions to analyse host cell signalling responses to infection. By applying this method to Yersinia pseudotuberculosis, we first unveil glycosylphosphatidylinositol-anchored protein domains recruitment to the bacterium cell surface binding site and concomitant cytoskeleton rearrangements using super-resolution fluorescence microscopy. Second, we demonstrate the feasibility of monitoring post-translationally modified proteins, for example, via ubiquitylation, during the first step of infection.



CONCLUSION: We provide an approach to discriminate between cellular signalling response activated at the plasma membrane during host-pathogen interaction and that is triggered during the internalisation of the pathogen within the cell.



SIGNIFICANCE: This approach adds to the technological arsenal to better understand and fight against pathogens and beyond the scope of microbiology to address conceptual issues of cell surface signalling.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid30911127,

title = {Targeting Type IV pili as an antivirulence strategy against invasive meningococcal disease},

author = {Kevin Denis and Marion Le Bris and Loic Le Guennec and Jean-Philippe Barnier and Camille Faure and Anne Gouge and Haniaa Bouzinba-Ségard and Anne Jamet and Daniel Euphrasie and Beatrice Durel and Nicolas Barois and Philippe Pelissier and Philippe C Morand and Mathieu Coureuil and Frank Lafont and Olivier Join-Lambert and Xavier Nassif and Sandrine Bourdoulous},

doi = {10.1038/s41564-019-0395-8},

issn = {2058-5276},

year  = {2019},

date = {2019-01-01},

journal = {Nat Microbiol},

volume = {4},

number = {6},

pages = {972--984},

abstract = {Bacterial virulence factors are attractive targets for the development of therapeutics. Type IV pili, which are associated with a remarkable array of properties including motility, the interaction between bacteria and attachment to biotic and abiotic surfaces, represent particularly appealing virulence factor targets. Type IV pili are present in numerous bacterial species and are critical for their pathogenesis. In this study, we report that trifluoperazine and related phenothiazines block functions associated with Type IV pili in different bacterial pathogens, by affecting piliation within minutes. Using Neisseria meningitidis as a paradigm of Gram-negative bacterial pathogens that require Type IV pili for pathogenesis, we show that piliation is sensitive to altered activity of the Na pumping NADH-ubiquinone oxidoreductase (Na-NQR) complex and that these compounds probably altered the establishment of the sodium gradient. In vivo, these compounds exert a strong protective effect. They reduce meningococcal colonization of the human vessels and prevent subsequent vascular dysfunctions, intravascular coagulation and overwhelming inflammation, the hallmarks of invasive meningococcal infections. Finally, they reduce lethality. This work provides a proof of concept that compounds with activity against bacterial Type IV pili could beneficially participate in the treatment of infections caused by Type IV pilus-expressing bacteria.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid30875396,

title = {Automated multi-sample acquisition and analysis using atomic force microscopy for biomedical applications},

author = {Antoine Dujardin and Peter De Wolf and Frank Lafont and Vincent Dupres},

doi = {10.1371/journal.pone.0213853},

issn = {1932-6203},

year  = {2019},

date = {2019-01-01},

journal = {PLoS One},

volume = {14},

number = {3},

pages = {e0213853},

abstract = {In the last 20 years, atomic force microscopy (AFM) has emerged as a ubiquitous technique in biological research, allowing the analysis of biological samples under near-physiological conditions from single molecules to living cells. Despite its growing use, the low process throughput remains a major drawback. Here, we propose a solution validated on a device allowing a fully automated, multi-sample analysis. Our approach is mainly designed to study samples in fluid and biological cells. As a proof of concept, we demonstrate its feasibility applied to detect and scan both fixed and living bacteria before completion of data processing. The effect of two distinct treatments (i.e. gentamicin and heating) is then evidenced on physical parameters of fixed Yersinia pseudotuberculosis bacteria. The multi-sample analysis presented allows an increase in the number of scanned samples while limiting the user's input. Importantly, cantilever cleaning and control steps are performed regularly-as part of the automated process-to ensure consistent scanning quality. We discuss how such an approach is paving the way to AFM developments in medical and clinical fields, in which statistical significance of results is a prerequisite.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid30240735,

title = {Biomechanical Control of Lysosomal Secretion Via the VAMP7 Hub: A Tug-of-War between VARP and LRRK1},

author = {Guan Wang and Sébastien Nola and Simone Bovio and Philippe Bun and Maïté Coppey-Moisan and Frank Lafont and Thierry Galli},

doi = {10.1016/j.isci.2018.05.016},

issn = {2589-0042},

year  = {2018},

date = {2018-06-01},

journal = {iScience},

volume = {4},

pages = {127--143},

abstract = {The rigidity of the cell environment can vary tremendously between tissues and in pathological conditions. How this property may affect intracellular membrane dynamics is still largely unknown. Here, using atomic force microscopy, we show that cells deficient in the secretory lysosome v-SNARE VAMP7 are impaired in adaptation to substrate rigidity. Conversely, VAMP7-mediated secretion is stimulated by more rigid substrate and this regulation depends on the Longin domain of VAMP7. We further find that the Longin domain binds the kinase and retrograde trafficking adaptor LRRK1 and that LRRK1 negatively regulates VAMP7-mediated exocytosis. Conversely, VARP, a VAMP7- and kinesin 1-interacting protein, further controls the availability for secretion of peripheral VAMP7 vesicles and response of cells to mechanical constraints. LRRK1 and VARP interact with VAMP7 in a competitive manner. We propose a mechanism whereby biomechanical constraints regulate VAMP7-dependent lysosomal secretion via LRRK1 and VARP tug-of-war control of the peripheral pool of secretory lysosomes.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid29874861b,

title = {Rv0613c/MSMEG_1285 Interacts with HBHA and Mediates Its Proper Cell-Surface Exposure in Mycobacteria},

author = {Romain Veyron-Churlet and Vincent Dupres and Jean-Michel Saliou and Frank Lafont and Dominique Raze and Camille Locht},

doi = {10.3390/ijms19061673},

issn = {1422-0067},

year  = {2018},

date = {2018-06-01},

journal = {Int J Mol Sci},

volume = {19},

number = {6},

abstract = {Heparin-binding haemagglutinin (HBHA) is a surface-exposed virulence factor of  and is involved in the binding of mycobacteria to non-phagocytic cells, allowing for extra-pulmonary dissemination of the bacilli. Despite its surface exposure, HBHA is not produced as a pre-protein containing a typical cleavable N-terminal signal peptide and is thus likely secreted by a Sec-independent, as of yet unknown mechanism. Here, we used the bacterial adenylate cyclase two-hybrid system to identify the proteins encoded by  and  as being able to interact with HBHA. Our study was focused on Rv0613c, as it showed more consistent interactions with HBHA than MmpL14. Deletion of its orthologous gene  in recombinant  producing HBHA from  resulted in the loss of proper surface exposure of HBHA, as evidenced by atomic force microscopy. Furthermore, the lack of  also abolished the clumping phenotype and rough colony morphology of the recombinant  and reduced its adherence to A549 epithelial cells. These phenotypes have previously been associated with surface-exposed HBHA. Thus, MSMEG_1285 is directly involved in the proper cell-surface exposure of HBHA. These observations identify MSMEG_1285/Rv0613c as the first accessory protein involved in the cell surface exposure of HBHA.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid30314966,

title = {ESCRT-mediated lysosome repair precedes lysophagy and promotes cell survival},

author = {Maja Radulovic and Kay O Schink and Eva M Wenzel and Viola Nähse and Antonino Bongiovanni and Frank Lafont and Harald Stenmark},

doi = {10.15252/embj.201899753},

issn = {1460-2075},

year  = {2018},

date = {2018-01-01},

journal = {EMBO J},

volume = {37},

number = {21},

abstract = {Although lysosomes perform a number of essential cellular functions, damaged lysosomes represent a potential hazard to the cell. Such lysosomes are therefore engulfed by autophagic membranes in the process known as lysophagy, which is initiated by recognition of luminal glycoprotein domains by cytosolic lectins such as Galectin-3. Here, we show that, under various conditions that cause injury to the lysosome membrane, components of the endosomal sorting complex required for transport (ESCRT)-I, ESCRT-II, and ESCRT-III are recruited. This recruitment occurs before that of Galectin-3 and the lysophagy machinery. Subunits of the ESCRT-III complex show a particularly prominent recruitment, which depends on the ESCRT-I component TSG101 and the TSG101- and ESCRT-III-binding protein ALIX Interference with ESCRT recruitment abolishes lysosome repair and causes otherwise reversible lysosome damage to become cell lethal. Vacuoles containing the intracellular pathogen  show reversible ESCRT recruitment, and interference with this recruitment reduces intravacuolar bacterial replication. We conclude that the cell is equipped with an endogenous mechanism for lysosome repair which protects against lysosomal damage-induced cell death but which also provides a potential advantage for intracellular pathogens.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid29720971,

title = {Oligomannose-Rich Membranes of Dying Intestinal Epithelial Cells Promote Host Colonization by Adherent-Invasive },

author = {Tetiana Dumych and Nao Yamakawa and Adeline Sivignon and Estelle Garenaux and Stefania Robakiewicz and Bernadette Coddeville and Antonino Bongiovanni and Fabrice Bray and Nicolas Barnich and Sabine Szunerits and Christian Slomianny and Martin Herrmann and Sébastien G Gouin and Alexander D Lutsyk and Luis E Munoz and Frank Lafont and Christian Rolando and Rostyslav Bilyy and Julie M J Bouckaert},

doi = {10.3389/fmicb.2018.00742},

issn = {1664-302X},

year  = {2018},

date = {2018-01-01},

journal = {Front Microbiol},

volume = {9},

pages = {742},

abstract = {A novel mechanism is revealed by which clinical isolates of adherent-invasive  (AIEC) penetrate into the epithelial cell layer, replicate, and establish biofilms in Crohn's disease. AIEC uses the FimH fimbrial adhesin to bind to oligomannose glycans on the surface of host cells. Oligomannose glycans exposed on early apoptotic cells are the preferred binding targets of AIEC, so apoptotic cells serve as potential entry points for bacteria into the epithelial cell layer. Thereafter, the bacteria propagate laterally in the epithelial intercellular spaces. We demonstrate oligomannosylation at two distinct sites of a glycoprotein receptor for AIEC, carcinoembryonic antigen related cell adhesion molecule 6 (CEACAM6 or CD66c), on human intestinal epithelia. After bacterial binding, FimH interacts with CEACAM6, which then clusters. The presence of the highest-affinity epitope for FimH, oligomannose-5, on CEACAM6 is demonstrated using LC-MS/MS. As mannose-dependent infections are abundant, this mechanism might also be used by other adherent-invasive pathogens.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid29141986,

title = {ArfGAP1 restricts  entry by controlling the actin cytoskeleton},

author = {Ok-Ryul Song and Christophe J Queval and Raffaella Iantomasi and Vincent Delorme and Sabrina Marion and Romain Veyron-Churlet and Elisabeth Werkmeister and Michka Popoff and Isabelle Ricard and Samuel Jouny and Nathalie Deboosere and Frank Lafont and Alain Baulard and Edouard Yeramian and Laurent Marsollier and Eik Hoffmann and Priscille Brodin},

doi = {10.15252/embr.201744371},

issn = {1469-3178},

year  = {2018},

date = {2018-01-01},

journal = {EMBO Rep},

volume = {19},

number = {1},

pages = {29--42},

abstract = {The interaction of  (Mtb) with pulmonary epithelial cells is critical for early stages of bacillus colonization and during the progression of tuberculosis. Entry of Mtb into epithelial cells has been shown to depend on F-actin polymerization, though the molecular mechanisms are still unclear. Here, we demonstrate that mycobacterial uptake into epithelial cells requires rearrangements of the actin cytoskeleton, which are regulated by ADP-ribosylation factor 1 (Arf1) and phospholipase D1 (PLD1), and is dependent on the M3 muscarinic receptor (MR). We show that this pathway is controlled by Arf GTPase-activating protein 1 (ArfGAP1), as its silencing has an impact on actin cytoskeleton reorganization leading to uncontrolled uptake and replication of Mtb. Furthermore, we provide evidence that this pathway is critical for mycobacterial entry, while the cellular infection with other pathogens, such as  and , is not affected. Altogether, these results reveal how cortical actin plays the role of a barrier to prevent mycobacterial entry into epithelial cells and indicate a novel role for ArfGAP1 as a restriction factor of host-pathogen interactions.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}