Bertrand Cinquin

Bertrand Cinquin
French National Centre for Scientific Research | CNRS · Institut Pierre-Gilles de Gennes

PhD Interface Biology
Supervisor of UAR3750 Technological platform for microfluidic devices at Institut Pierre Gilles de Gennes

About

58
Publications
5,760
Reads
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787
Citations
Additional affiliations
August 2019 - August 2019
French National Centre for Scientific Research
Position
  • Engineer
October 2013 - present
SOLEIL synchrotron
Position
  • PostDoc Position
October 2013 - November 2015
French National Centre for Scientific Research
Position
  • PostDoc Position

Publications

Publications (58)
Article
In total hip arthroplasty, the hip joint is replaced by artificial materials. The fibrous tissue that re-forms around the hip joint after surgery plays an important role in joint stability. Here, the morphological and mechanical properties of the scar tissue that forms around implants composed of either polymer and metal or ceramic are compared wit...
Article
Full-text available
Autosomal Dominant Polycystic Kidney Disease (ADPKD) is a major renal pathology provoked by the deletion of PKD1 or PKD2 genes leading to local renal tubule dilation followed by the formation of numerous cysts, ending up with renal failure in adulthood. In vivo , renal tubules are tightly packed, so that dilating tubules and expanding cysts may hav...
Article
Full-text available
In the present work, droplet-based microfluidics and sol-gel techniques were combined to synthesize highly monodisperse zinc oxide (ZnO) microspheres, which can be doped easily and precisely with dyes, such as rhodamine B (RhB), and whose size can be finely tuned in the 10-30 µm range. The as-synthesized microparticles were analyzed by scanning ele...
Article
Full-text available
A lipid droplet (LD) core of a cell consists mainly of neutral lipids, triacylglycerols and/or steryl esters (SEs). The structuration of these lipids inside the core is still under debate. Lipid segregation inside LDs has been observed but is sometimes suggested to be an artefact of LD isolation and chemical fixation. LD imaging in their native sta...
Article
Full-text available
Triphenylamines (TPAs) were previously shown to trigger cell death under prolonged one- or two-photon illumination. Their initial subcellular localization, before prolonged illumination, is exclusively cytoplasmic and they translocate to the nucleus upon photoactivation. However, depending on their structure, they display significant differences in...
Article
Full-text available
Current research findings clearly reveal the role of the microalga’s cell wall as a key obstacle to an efficient and optimal compound extraction. Such extraction process is therefore closely related to the microalga species used. Effects of electrical or mechanical constraints on C. reinhardtii’s structure and particularly its cell wall and membran...
Chapter
Confocal laser scanning microscopy (CLSM) is one of the most relevant technologies for studying biofilms in situ. Several tools have been developed to investigate and quantify the architecture of biofilms. However, an approach to accurately quantify the intensity of a fluorescent signal over biofilm depth is still lacking. Here we present a tool de...
Article
Background: Nitric-oxide synthases (NOS) catalyze the formation of NO using NADPH as electron donor. We have recently designed and synthesized a new series of two-photon absorbing and photoactivatable NADPH analogues (NT). These compounds bear one or two carboxymethyl group(s) on the 2'- or/and 3'-position(s) of the ribose in the adenosine moiety,...
Article
Full-text available
The efficacy of antibacterial molecules depends on their capacity to reach inhibitory concentrations in the vicinity of their target. This is particularly challenging for drugs directed against Gram-negative bacteria, which have a complex envelope comprising two membranes and efflux pumps. Precise determination of the bacterial drug content is an e...
Article
Human mesenchymal stem cells were reseeded in decellularized human bone subject to a controlled mechanical loading to create a bone-on-chip that was cultured for over 26 months. The cell morphology and their secretome were characterized using immunohistochemistry and in situ immunofluorescence under confocal microscopy. The presence of stem cell de...
Article
Full-text available
Bacterial multidrug resistance is a worrying health issue. In Gram-negative antibacterial research, the challenge is to define the antibiotic permeation across the membranes. Passing through the membrane barrier to reach the inhibitory concentration inside the bacterium is a pivotal step for antibacterial molecules. A spectrofluorimetric methodolog...
Article
Confocal laser scanning microscopy (CLSM) is one of the most relevant technologies for studying biofilms in situ. Several tools have been developed to investigate and quantify the architecture of biofilms. However, an approach to quantify correctly the evolution of intensity of a fluorescent signal as a function of the structural parameters of a bi...
Article
Full-text available
A main challenge in chemotherapy is to determine the in cellulo parameters modulating the drug concentration required for therapeutic action. It is absolutely urgent to understand membrane permeation and intracellular concentration of antibiotics in clinical isolates: passing the membrane barrier to reach the threshold concentration inside the bact...
Article
Full-text available
Dietary restriction increases the longevity of many organisms, but the cell signaling and organellar mechanisms underlying this capability are unclear. We demonstrate that to permit long-term survival in response to sudden glucose depletion, yeast cells activate lipid-droplet (LD) consumption through micro-lipophagy (µ-lipophagy), in which fat is m...
Article
Full-text available
Sickle cell disease is a destructive genetic disorder characterized by the formation of fibrils of deoxygenated hemoglobin, leading to the red blood cell (RBC) morphology changes that underlie the clinical manifestations of this disease. Using cryogenic soft x-ray tomography (SXT) we characterized the morphology of sickled RBCs in terms of volume a...
Article
Full-text available
Bacterial multidrug resistance is a significant health issue. A key challenge, particularly in Gram-negative antibacterial research, is to better understand membrane permeation of antibiotics in clinically relevant bacterial pathogens. Passing through the membrane barrier to reach the required concentration inside the bacterium is a pivotal step fo...
Article
Full-text available
Epigenetic regulation serves as the basis for stem cell differentiation into distinct cell types, but it is unclear how global epigenetic changes are regulated during this process. Here, we tested the hypothesis that global chromatin organization affects the lineage potential of stem cells and that manipulation of chromatin dynamics influences stem...
Data
Nuclear architecture is distinctly different during stem cell differentiation into mature cells. Soft X-ray tomography was used to image whole, fully hydrated cells. The movies feature the cell (gray) and the shape of the nucleus (blue), euchromatin (green), nucleoli (red), lipid bodies (yellow), and mitochondria (gold); related to Figure 2.
Article
Alison D Walters, Christopher K May, Emma S Dauster, Bertrand P Cinquin, Elizabeth A Smith, Xavier Robellet, Damien D’Amours, Carolyn A Larabell, Orna Cohen-Fix Abnormal nuclear size and shape are hallmarks of aging and cancer [ 1, 2 ]. However, the mechanisms regulating nuclear morphology and nuclear envelope (NE) expansion are poorly understood....
Article
Beamline 2.1 (XM-2) is a transmission soft X-ray microscope in sector 2 of the Advanced Light Source at Lawrence Berkeley National Laboratory. XM-2 was designed, built and is now operated by the National Center for X-ray Tomography as a National Institutes of Health Biomedical Technology Research Resource. XM-2 is equipped with a cryogenic rotation...
Article
Full-text available
Total internal reflection fluorescence microscopy (TIRFM) is the method of choice to visualize a variety of cellular processes in particular events localized near the plasma membrane of live adherent cells. This imaging technique not relying on particular fluorescent probes provides a high sectioning capability. It is, however, restricted to a sing...
Article
Full-text available
Le rayonnement synchrotron est un continuum d’énergie des infrarouges aux rayons X-durs. Avec l’amélioration des sources − une meilleure stabilité, une plus grande brillance, une plus faible divergence du faisceau et une meilleure cohérence − de plus en plus de lignes de lumière à travers le monde, et à SOLEIL en particulier, proposent des stations...
Article
Full-text available
Each class of microscope is limited to imaging specific aspects of cell structure and/or molecular organization. However, imaging the specimen by complementary microscopies and correlating the data can overcome this limitation. Whilst not a new approach, the field of correlative imaging is currently benefitting from the emergence of new microscope...
Article
Correlated imaging is the process of imaging a specimen with two complementary modalities, and then combining the two data sets to create a highly informative, composite view. A recent implementation of this concept has been the combination of soft x-ray tomography (SXT) with fluorescence cryogenic microscopy (FCM). SXT-FCM is used to visualize cel...
Article
Full-text available
Langerin is required for the biogenesis of Birbeck granules (BGs), the characteristic organelles of Langerhans cells. We previously used a Langerin-YFP fusion protein having a C-terminal luminal YFP tag to dynamically decipher the molecular and cellular processes which accompany the traffic of Langerin. In order to elucidate the interactions of Lan...
Data
Stacks of BG-like membranes are also induced by a GFP-Lang fusion protein. A GFP-Lang fusion protein was transiently expressed in M10 cells. (A) A GFP+ cell (yellow arrow) was located by fluorescence microscopy (left panel), bright field microscopy (middle panel) and electron microscopy (right panel). (B) GFP+ puncta (red, blue and orange arrowhead...
Data
Restoration of the mobility of YFP-Lang with the A206K monomerizing mutant of YFP. Maximum intensity projections, generated from t-stacks of images acquired during FRAP experiments, are depicted for M10-Lang-YFP (left panel), M10-YFP-Lang (middle panel) and M10-mYFP-Lang (right panel) cells. The mobility of the Langerin/YFP chimeras can be roughly...
Data
A 3D reconstruction of a stack of BG-like membranes viewed with FIB/SEM, demonstrating continuity with the rough ER (same cell as in Fig. 4 ). (AVI)
Data
M10 transfected cells expressing YFP-LangE293A were fixed included in Epon. Sometimes, the central striation characteristical to classical BGs were noticed (white arrows). (TIF)
Data
Images acquired during FRAP experiments on transfected M10 cells expressing Lang-YFP cells. Multiple fluorescent vesicles can be seen in motion. (AVI)
Data
Characterization of the BG-like structures. (A) The presence of the ER chaperones BiP and calnexin (CNX) in YFP+ large puncta was studied in colocalization experiments. M10-YFP-Lang cells were fixed, permeabilized and stained with rabbit anti-BiP or anti-calnexin Abs or an isotype control (revealed with Cy5-conjugated donkey anti-rabbit Abs, red)....
Data
M10 transfected cells expressing YFP-LangE293A were fixed with 0.2% gluteraldehyde 2% paraformaldehyde, frozen in liquid N2, cryosections were labeled with rabbit polyclonal anti-GFP Abs, revealed with protein A conjugated 10 nM gold particles (PAG, Utrecht) and analyzed on CM120 electronic microscope (FEI). (TIF)
Data
Images acquired during FRAP experiments on transfected M10 cells expressing YFP-Lang cells. The fluorescent structures are nearly motionless. (AVI)
Data
CLEM analysis of cells expressing mYFP-Lang. M10 cells expressing mYFP-Lang were processed for CLEM as in Fig. 2. On the same Aclar® culture support, two cells with different phenotypes were observed: the first (a, a2, yellow arrowhead) displayed small puncta which were identified ultrastructurally as BG-like OSER; the second (b, b2, blue arrowhead...
Data
Images acquired during FRAP experiments on transfected M10 cells expressing mYFP-Lang. The introduction of the A206K mutation restores the mobility of the fluorescent vesicles. (AVI)
Article
Full-text available
A large body of knowledge relating to the constitution of Rab GTPase/Rab effector complexes and their impact on both membrane domain organization and overall membrane trafficking has been built up in recent years. However in the context of the live cell there are still many questions that remain to be answered, such as where and when these complexe...
Article
Full-text available
The study of membrane plasticity and the role of molecular «machines» in the control of biogenesis of the endo-cellular membranes have highlighted the crucial role of “Rab” GTPases family as organizing centers of functional molecular platforms in membrane sub-domains. Yet, to understand the regulation and coordination of these molecular assemblies,...
Conference Paper
Full-text available
Endocytosis/recycling and exocytosis are mechanisms conserved through evolution allowing cells to communicate with their external medium. In order to study these dynamic processes, the present work proposes a patch-based method for detecting recycling or exocytotic events at the Plasma membrane in fast TIRF microscopy combined with the computation...
Conference Paper
Full-text available
In this paper a framework for defining scale-spaces, based on the computational geometry concepts of �-shapes, is proposed. In this approach, objects (curves or surfaces) of increasing convexity are com- puted by selective sub-sampling, from the original shape to its convex hull. The relationships with the Empirical Mode Decomposition (EMD), the cu...
Article
Full-text available
In this paper a framework for defining scale-spaces, based on the computational geometry concepts of �-shapes, is proposed. In this approach, objects (curves or surfaces) of increasing convexity are com- puted by selective sub-sampling, from the original shape to its convex hull. The relationships with the Empirical Mode Decomposition (EMD), the cu...
Book
In this paper a framework for defining scale-spaces, based on the computational geometry concepts of a-shapes, is proposed. In this approach, objects (curves or surfaces) of increasing convexity are computed by selective sub-sampling, from the original shape to its convex hull. The relationships with the Empirical Mode Decomposition (EMD), the curv...
Article
We have studied the fluorescence decays of the purified enhanced cyan fluorescent protein (ECFP, with chromophore sequence Thr-Trp-Gly) and of its variant carrying the single H148D mutation characteristic of the brighter form Cerulean. Both proteins exhibit highly complex fluorescence decays showing strong temperature and pH dependences. At neutral...

Questions

Question (1)
Question
Dear Community,
As I try to understand the internalisation of a drug, I observed some conflicting results.
To do so I simply tune the temperature.  
4 °C No internalisation
37 °C  Internalisation
 I should observe  a certain ratio of fluorescence if it is purely diffusive and a ratio way bigger if an active process occurs.
When I observe fixed cells (PFA 4%) I observe a certain ratio independant of the temperature.
When I observe living cells, I observe an emission of fluorescence only at 37 °C and not at 4°C. 
Is anyone of you already had similar observations ?
Thank you for your help !
How can I explain such a difference of behavior ?

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Projects (2)
Project
Confocal analysis, structural properties and formation mechanism of ZnO microcapsules and their shell