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Florence Valence CIRM, Inra, Rennes : Working group of the French “BIOBANQUES” infrastructure; International audience; A calculation grid developed by an international expert group was tested across biobanks in six countries to evaluate costs for collections of various types of biospecimens. The assessment yielded a tool for setting specimen-access prices that were transparently related to biobank costs, and the tool was applied across three models of collaborative partnership.

My encounter with Derrida was organized around Circonfession. This text occupies a very distinctive place within his body of work. It seems to me that its problematic object more or less determined the conditions of our dialogue. Indeed, this "more or less" defines the space of a philosophical question that Jacques Derrida helped pose, I believe, in a quite original manner-at least within the domain of philosophy. In this process, Derrida's texts, as I have always read them, are doomed to be embodied (in the form of encounters, dialogues, protests, doubts). Therein undoubtedly lies the secret of a certain fervor, which became manifest spontaneously and in multiple forms after October 9, 2004. I heard in circles around me and read at the time what I myself had always observed and felt-namely, that Jacques Derrida's life was inseparable from his work, that our tears also had a philosophical meaning--those very tears that Circonfession works so hard to bring into the realm of thought. What I retain from this stunning book (hardly a book, in fact--more a series of annotations at the bottom of the page), from this commentary in the form of an autobiography (or this autobiography in the form of a commentary--the whole question is there), what I retain is the thesis-formulated with sufficient resolve to constitute henceforth a problemthat the biographical event (here circumcision) determines the nature, the scope, the acuteness of philosophical questioning and proposition. Here is how this is formulated in the notebooks that Circonfession works through

A variety of exogenous and endogenous agents, including toxic compounds, alcohol, drugs and viruses, can cause acute and chronic liver injuries which may lead to inflammation and fibrogenesis. Most hepatocellular carcinomas arise on a fibrotic or cirrhotic liver, and progression of hepatocellular carcinoma is associated with continuous changes in the cellular microenvironment. Extracellular matrix remodelling is a complex process involving synthesis and degradation of matrix components that modulate the fate of cancer cells. Proteases, including matrix metalloproteinases, cleave matrix components and release polypeptide modules with specific biological activities. Knowledge of the cellular and molecular mechanisms involved in extracellular matrix remodelling will open the path to biomarker identification and tailored treatments targeting the liver tumor microenvironment.

International audience; Objectives. The aim of this study was to assess the effectiveness of SPECT/CT for volume measurements and to report a case illustrating the major impact of SPECT/CT in calculating the vascularized liver volume and dosimetry prior to injecting radiolabelled yttrium-90 microspheres (Therasphere). Materials and Methods. This was a phantom study, involving volume measurements carried out by two operators using SPECT and SPECT/CT images. The percentage of error for each method was calculated, and interobserver reproducibility was evaluated. A treatment using Therasphere was planned in a patient with three hepatic arteries, and the quantitative analysis of SPECT/CT for this patient is provided. Results. SPECT/CT volume measurements proved to be accurate (mean error

International audience; Basement membranes contain three major components (ie collagen IV, laminin, and the heparan sulfate proteoglycan termed perlecan). Although the distribution and origin of both collagen IV and laminin have been well documented in the liver, perlecan has been poorly investigated, so far. We have studied the distribution and cellular origin of perlecan in rat livers in various conditions as well as in hepatocyte primary culture. By immunolocalization in both adult and 18-day-old fetal liver, perlecan was found in portal spaces, around central veins, and throughout the lobule. Immunoelectron microscopy revealed its presence at the level of basement membranes surrounding bile ducts and blood vessels, and in the space of Disse discontinuously interacting with hepatocyte microvilli. Precursors of perlecan were detected in the rough endoplasmic reticulum of bile duct cells and both vascular and sinusoidal endothelial cells. Both hepatocytes and Ito cells were negative. Northern-blot analysis confirmed the lack of appreciable expression of perlecan in hepatocytes isolated from either fetal or adult livers. In 18-month-diethylnitrosamine-treated rat liver, perlecan was abundant in neoplastic nodules. Electron microscopic investigation revealed an almost continuous layer of perlecan in the space of Disse and intracellular staining in sinusoidal endothelial cells, only. Perlecan mRNAs were detectable in malignant nodules, and absent in hepatocytes from nontumorous areas. Hepatocytes expressed high levels of perlecan mRNAs only when put in culture. This expression was reduced in conditions that allow improvement of hepatocyte survival and function (ie addition of corticoids, dimethylsulfoxide or nicotinamide to the medium, or in coculture with liver epithelial cells from biliary origin). Immunolocalization by light and electron microscopy showed that deposition of the proteoglycan occurred in coculture, in basement membranelike structures located around hepatocyte cords. In vitro attachment assay of hepatocytes on purified perlecan substrate indicated that these cells may interact with the proteoglycan through integrins which belong to the beta 1 family. These data suggest that deposition of perlecan in the space of Disse requires cellular cooperation. This article on perlecan, the third major component of hepatic basement membranes, shows a unique cellular origin in the liver and, as found for both collagen IV and laminin, an expression in adult hepatocytes when place in culture.

Laminin deposition is increased in fetal liver and in a variety of liver diseases, including the development of carcinoma. We investigated the role of the hepatocyte in the synthesis of both laminin and its 32- to 67-kd receptor in normal adult, fetal, and diethylnitrosamine-treated rat livers, and in adult rat hepatocyte primary cultures. Laminin was localized by immunoelectron microscopy in the endoplasmic reticulum of hepatocytes in fetal-derived and in 18-month-old diethylnitrosamine-treated rat livers. Steady-state mRNA levels for the three chains of laminin (A, B1, and B2) and the laminin receptor (LBP-32) were examined. Northern-blot analyses showed that hepatocytes at all stages lacked the A-chain mRNA. B1-chain mRNA was undetectable in normal adult hepatocytes, while significant levels of B1-chain mRNA were found in fetal hepatocytes and in adult hepatocyte primary culture. In hepatocytes from diethylnitrosamine-treated rats, B1-chain mRNAs were abundant and were present mainly in nodular formations rather than in the nontumorous areas. B2-chain mRNAs were barely detectable in either normal adult or fetal hepatocytes. In diethylnitrosamine-treated rats, the steady-state B2-chain mRNA level was higher in nodules than in nontumorous areas. In primary culture, B2-chain mRNAs were present as early as 4 hours after adult hepatocyte seeding, and dramatically increased during the following 2 days. Only low levels of laminin-receptor (LBP-32) mRNAs were present in normal adult hepatocytes, whereas the levels were high in the fetal and in the tumor-containing livers. In diethylnitrosamine-treated rats, LBP-32 mRNAs were more abundant in nodular formations rather than in nontumorous areas. In hepatocyte primary culture, the expression of the LBP-32 mRNA dramatically increased during the first 24 hours. These results show that in hepatocytes, expression of laminin chains and its receptor LBP-32 are not coordinated and depends on the maturation of the cells. In addition, they suggest that the expression of B1 and B2 chains in adult hepatocytes is related to changes of the normal phenotype and/or the pericellular environment.

As part of a study on terpene hydrocarbons in the biosphere-atmosphere exchange processes, an entirely automatic device has been elaborated for sampling, preconcentration and analysis of isoprene and the principal atmospheric monoterpenes. This device comprises mainly a gas chromatograph for analysis and a programmable controller for the management of the operations. It permits measurement of the concentration and flux rate of terpenes. Automatic and continuous cycles (sampling-analysis) were carried out over several days. They were characterized by a reproducibility lower than 1%; their analytical characteristics were quite acceptable.

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Cellular and molecular mechanisms involved in the deposition of extracellular matrix components in both normal and fibrotic liver are still poorly understood. We have investigated the influence of cooperation between Ito cells and hepatocytes in matrix deposition in vitro. Immunoprecipitation of radiolabeled proteins from media of 5-day-old Ito cell primary cultures showed that these cells secreted high levels of the major basement membrane components, ie, collagen IV, laminin, and entactin/nidogen. By immunocytochemistry, precursors of basement membrane components were found intracellularly, but only scarce deposits were seen around the cells. When hepatocytes were added to 2-day-old Ito cell primary cultures, they established close contacts with Ito cells in less than 24 hours and expressed ZO-1, a tight junction-associated protein not detectable in standard hepatocyte culture. Cytochemistry analysis revealed an abundant extracellular matrix deposited over hepatocyte cords and between hepatocytes and Ito cells. Immunocytochemistry studies showed that this matrix contained laminin, fibronectin, and collagens proIII and IV. These data indicate that a high level of matrix protein synthesis by liver cells in vitro is not sufficient to induce extracellular matrix deposition, and that cell-cell interactions are strongly involved in this process. Hepatocyte/Ito cell co-culture, which may reflect the actual situation in vivo, represents a useful tool for studying liver fibrogenesis.

The mortality rate of fulminant hepatic failure is about 80%. Besides orthotopic liver transplantation, specific therapies are not currently available. Indeed, not only removal of toxins is required, by means of dialysis or hemoperfusion, but specific hepatic functions must be provided to allow spontaneous liver regeneration or as a bridge before liver transplantation. Treatment with an extracorporeal bioartificial liver is an attractive approach. This system was successfully used for the correction of the Gunn rat genetic defect which results in the lack of bilirubin conjugation. The development of this system for clinical purpose requires both a large yield of functional hepatocytes and their immunoprotection in an appropriate device. We have isolated normal porcine hepatocytes by collagenase perfusion of the liver; cells are subsequently entrapped within membrane-coated alginate beads which are inoculated in a bioreactor. Plasma from an animal undergoing fulminant hepatic failure by end-to-site portocaval shunt and whole porta hepatic tightening circulates within the bioreactor. Porcine hepatocytes express liver-specific functions at high levels, particularly secretion of plasma proteins and several enzyme activities involved in the detoxication and biotransformation of xenobiotics. In addition, hepatocytes are immunoseparated from circulating immunoglobulins. Ethical concerns are discussed in the field of physiopathology, immunopathology and public health, as a prerequisite to create departments of Cell Therapy, in the near future.

The reversibility of hepatic fibrosis was investigated in an experimental model of extrahepatic cholestasis in the rat after common bile duct ligation for 2 weeks, followed by bilioduodenal anastomosis for 3 weeks. Bile duct ligation resulted in a transitory marked elevation in the serum concentration of 5'-nucleotidase, alkaline phosphatase, and bilirubin during the first 3 days. Then these levels decreased to threefold, twofold, and 100-fold the normal values, respectively, during the following 4 weeks. Histologic examination of the liver disclosed extensive bile duct proliferation and the formation of periportal fibrosis, with only slight inflammation and necrosis. The distribution of the major components of the hepatic extracellular matrix was analyzed 2 weeks after bile duct ligation, using the indirect immunoperoxidase method. Fibrous septa were found to be strongly stained for collagens I, pro-III, III and IV, fibronectin, and laminin. The most intense staining was found in enlarged periportal areas, collagen IV and laminin being particularly abundant around newly formed bile ducts. These changes paralleled high steady-state levels of alpha 1(I) and alpha 1(IV) collagen and B2 chain laminin mRNAs. Relief of the obstruction for 2 weeks resulted in a shift in the serum concentration of 5'-nucleotidase, alkaline phosphatase, and bilirubin toward normal values. A dramatic resorption of bile duct proliferations and periportal fibrosis were observed. Three weeks after bile duct repermeabilization, immunohistochemical study showed that the pattern of distribution of extracellular matrix components was almost normal, except for collagen IV, which remained abundant in the sinusoids when compared with the normal liver. In parallel, the steady-state B2-chain laminin mRNA level became lower than in cholestatic livers, whereas alpha 1(I) and alpha 1(IV) mRNAs were almost undetectable. These results show that hepatic fibrosis induced by experimental extrahepatic cholestasis in rat disappears in less than 3 weeks after relief of bile duct obstruction, suggesting that an active degradation of matrix protein occurs, except for collagen IV in the sinusoid.

This second issue of the French Complex Systems Roadmap is the outcome of the Entretiens de Cargese 2008, an interdisciplinary brainstorming session organized over one week in 2008, jointly by RNSC, ISC-PIF and IXXI. It capitalizes on the first roadmap and gathers contributions of more than 70 scientists from major French institutions. The aim of this roadmap is to foster the coordination of the complex systems community on focused topics and questions, as well as to present contributions and challenges in the complex systems sciences and complexity science to the public, political and industrial spheres.

Fibroblast growth factor (FGF-2) is a multifunctional growth factor. In cells producing this factor, FGF-2 is synthesized as different molecular weight isoforms lacking the signal peptide sequence for secretion. All forms are highly concentrated in cells. The presence of a nuclearization signal sequence in some isoforms suggests the involvement of these isoforms in cell functions bypassing the cell surface receptors. Our aims were to better define the intracellular localizations of the FGF-2 isoforms by immunocytochemistry and confocal microscopy and to analyze whether these isoforms were involved in the expression of extracellular matrix (ECM) components. We chose the pancreatic acinar cell line AR4-2J since it does not synthesize FGF-2. These cells were retrovirally transfected by point-mutated FGF-2 cDNAs. The cell lines obtained produced either the 18 kDa form (A5 cells) or the 22.5 kDa form (A3 cells). In A5 cells, the 18 kDa form was found in the cytoplasm, on the cell surface reflecting its secretion, and in the nucleoli. Parental AR4-2J cells treated with exogenous FGF-2 exhibited identical localizations, suggesting that in A5 cells the 18 kDa form followed the same translocation pathways than the exogenous FGF-2. By contrast, in A3 cells the 22.5 kDa form was predominantly localized in the nucleoplasm but was undetectable on the cell surface, suggesting its direct translocation to the nucleus. Northern and Western blot analysis showed that cells expressing the high molecular weight form exhibited a decrease of laminin B1 protein level and mRNA stability. In contrast, collagen IV and fibronectin expressions were unmodified either in FGF-2-transfected cells or in parental cells treated by exogenous FGF-2. Thus, these data indicate that: 1) 18 and 22.5 kDa FGF-2 are preferentially localized in different nuclear compartments and 2) the high molecular weight form plays a role on the expression of some ECM components.

Hepatocellular carcinoma (HCC) is the third cause of cancer-related death worldwide. Half of them show activation of Wnt/β-catenin pathway, caused by activating CTNNB1 exon 3 mutation of by stimulation of FRZD receptor. Transcriptomic based HCC classifications showed that this two types of activation were associated with distinct tumor subtypes. We tried to better understand the molecular phenotypes and the clinical features associated with these subtypes. In a first part, we linked extracellular Wnt activation with a stem/progenitor phenotype and with fibrous hotspot in HCC. Fibrous hotspot, which were called “fibrous nest”, can be detected by routine anatomic pathology analyses. We also showed that HAPLN1, an extracellular matrix protein induced by Wnt3a in progenitor HepaRG cells, was a new marker of stemness and bad outcome in HCC. Those results shows the associations between extracellular Wnt activation, extracellular matrix remodeling and tumor aggressiveness. In a second part, a transcriptome meta-analysis of 1133 HCCs highlighted 4 robust subclasses. CTNNB1 mutation, predicted by a 5-genes score based method, was associated with one of these subclasses and with good clinical features. We also highlighted a new subclass of CTNNB1 wild type HCCs associated with tumor differentiation, signatures of periportal metabolism and good outcome. This subclass was probably a confounding factor in survival studies comparing HCCs carrying mutant versus those carrying wild-type CTNNB1. Finally, we highlighted strong negative associations between CTNNB1 mutation and inflammation as well as tumor fibrosis in three independent cohorts. Preliminary results of in vitro HepaRG cells mutated for CTNNB1 in T41 and stimulated by LPS suggest an inhibitory effect of β-caténine on NF-κB. In conclusion, our results show that the two types of Wnt activation in HCC are associated with very distinct molecular phenotypes and clinical features., Le carcinome hépatocellulaire (CHC) est une des principales causes de mortalité par cancer dans le monde. Dans environ 50% des tumeurs, on observe les signes d’une activation de la voie Wnt/β-caténine, causée par une mutation de l’exon 3 du gène CTNNB1 ou par stimulation du récepteur FRZD. Des études transcriptomiques du CHCs ont montré que ces deux modes d’activation étaient associés à des sous-types de tumeurs différents. Nous avons cherché à mieux comprendre les caractéristiques cliniques et le phénotype moléculaire de ces deux sous-types de CHCs. Dans un premier temps, nous avons fait le lien entre l'activation Wnt extracellulaire, un phénotype de cellules cancéreuses souches ou progénitrices et la présence de foyers de fibrose discrète intra-tumorale, observable par examen histopathologique, que nous avons appelés "nids fibreux". Nous avons également mis en évidence HAPLN1, une protéine de la matrice extracellulaire dont l’expression est stimulée par Wnt3a dans un modèle de cellules hépatiques progénitrices HepaRG, comme un nouveau marqueur d’agressivité du CHC. Ces résultats montrent une association entre l’activation Wnt extracellulaire et une agressivité tumorale passant par un remodelage matriciel. Dans un second temps, une Méta-analyse de données publiques de transcriptomique a permis de mettre évidence 4 sous-types de CHCs. La mutation CTNNB1, prédite par l’expression de 5 marqueurs par une méthode développée durant la thèse, était associée à un de ces sous-types et à un bon pronostic clinique. Nous avons également isolé un nouveau sous-type de CHC de bon pronostic exprimant un phénotype de tumeur différenciée et des signatures de métabolisme hépatique périportales. Ce sous-type a probablement été un facteur confondant dans les études précédentes mesurant l’association de la mutation CTNNB1 avec un bon pronostic. Enfin, nous avons mis en évidence une forte association négative entre la mutation CTNNB1 et l’inflammation ainsi que la fibrose tumorale dans trois cohortes indépendantes. Cet effet pourrait être provoqué par une inhibition de NF-κB par la β-caténine mutée, comme suggérée par des résultats préliminaires issue d’un modèle in vitro d’HepaRG mutés T41 stimulés par LPS. Nos résultats suggèrent donc que les deux modes d’activation de la voie Wnt/β-caténine sont associés à des mécanismes moléculaires, des profils d’expression, des phénotypes et des pronostics cliniques très différents.