Induction of Selective Blood-Tumor Barrier Permeability and Macromolecular Transport by a Biostable Kinin B1 Receptor Agonist in a Glioma Rat Model

Treatment of malignant glioma with chemotherapy is limited mostly because of delivery impediment related to the blood-brain tumor barrier (BTB). B1 receptors (B1R), inducible prototypical G-protein coupled receptors (GPCR) can regulate permeability of vessels including possibly that of brain tumors. Here, we determine the extent of BTB permeability induced by the natural and synthetic peptide B1R agonists, LysdesArg9BK (LDBK) and SarLys[dPhe8]desArg9BK (NG29), in syngeneic F98 glioma-implanted Fischer rats. Ten days after tumor inoculation, we detected the presence of B1R on tumor cells and associated vasculature. NG29 infusion increased brain distribution volume and uptake profiles of paramagnetic probes (Magnevist and Gadomer) at tumoral sites (T1-weighted imaging). These effects were blocked by B1R antagonist and non-selective cyclooxygenase inhibitors, but not by B2R antagonist and non-selective nitric oxide synthase inhibitors. Consistent with MRI data, systemic co-administration of NG29 improved brain tumor delivery of Carboplatin chemotherapy (ICP-Mass spectrometry). We also detected elevated B1R expression in clinical samples of high-grade glioma. Our results documented a novel GPCR-signaling mechanism for promoting transient BTB disruption, involving activation of B1R and ensuing production of COX metabolites. They also underlined the potential value of synthetic biostable B1R agonists as selective BTB modulators for local delivery of different sized-therapeutics at (peri)tumoral sites

Vital NETosis vs. suicidal NETosis during normal pregnancy and preeclampsia

Background: NETosis occurs in the context of infection or inflammation and results in the expulsion of decondensed DNA filaments called NETs (Neutrophil Extracellular Traps) into the extracellular environment. NETosis activates coagulation and contributes to the thrombotic risk of inflammatory diseases. To date, two mechanisms of NETosis have been identified: suicidal NETosis, in which neutrophils die after expelling the filaments; and vital NETosis, in which expulsion appears without altering the membrane. Human pregnancy is associated with a mild pro-inflammatory state, which is increased in the event of complications such as preeclampsia (PE). NETosis has been observed in these situations, but the mechanism of its production has not yet been studied. The aim of our study was to evaluate the balance of vital vs. suicidal NETosis in normal pregnancy and in PE.Patients/Methods: Neutrophils from healthy volunteers were stimulated with plasma from normal pregnancies (n = 13) and from women developing preeclampsia (n = 13). Immunofluorescent labelling was performed to determine the percentages and origin of NETs in both groups. Inhibition with suicidal or vital NETosis inhibitors was also performed to validate our results.Results: We found a significant increase in NETs in women with PE compared to women with normal pregnancies. We showed that vital and non-vital NETosis are present in normal and preeclamptic pregnancies. We demonstrated that the higher proportion of NETs observed in PE was due to non-vital NETosis whose main component is represented by suicidal NETosis.Discussion: These results suggest the important part of non-vital NETosis in the pathophysiology of PE

Genome-Wide Diet-Gene Interaction Analyses for Risk of Colorectal Cancer

Dietary factors, including meat, fruits, vegetables and fiber, are associated with colorectal cancer; however, there is limited information as to whether these dietary factors interact with genetic variants to modify risk of colorectal cancer. We tested interactions between these dietary factors and approximately 2.7 million genetic variants for colorectal cancer risk among 9,287 cases and 9,117 controls from ten studies. We used logistic regression to investigate multiplicative gene-diet interactions, as well as our recently developed Cocktail method that involves a screening step based on marginal associations and gene-diet correlations and a testing step for multiplicative interactions, while correcting for multiple testing using weighted hypothesis testing. Per quartile increment in the intake of red and processed meat were associated with statistically significant increased risks of colorectal cancer and vegetable, fruit and fiber intake with lower risks. From the case-control analysis, we detected a significant interaction between rs4143094 (10p14/near GATA3) and processed meat consumption (OR = 1.17; p = 8.7E-09), which was consistently observed across studies (p heterogeneity = 0.78). The risk of colorectal cancer associated with processed meat was increased among individuals with the rs4143094-TG and -TT genotypes (OR = 1.20 and OR = 1.39, respectively) and null among those with the GG genotype (OR = 1.03). Our results identify a novel gene-diet interaction with processed meat for colorectal cancer, highlighting that diet may modify the effect of genetic variants on disease risk, which may have important implications for prevention. © 2014

DataSHIELD: taking the analysis to the data, not the data to the analysis

Research in modern biomedicine and social science requires sample sizes so large that they can often only be achieved through a pooled co-analysis of data from several studies. But the pooling of information from individuals in a central database that may be queried by researchers raises important ethico-legal questions and can be controversial. In the UK this has been highlighted by recent debate and controversy relating to the UK's proposed 'care.data' initiative, and these issues reflect important societal and professional concerns about privacy, confidentiality and intellectual property. DataSHIELD provides a novel technological solution that can circumvent some of the most basic challenges in facilitating the access of researchers and other healthcare professionals to individual-level data. Commands are sent from a central analysis computer (AC) to several data computers (DCs) storing the data to be co-analysed. The data sets are analysed simultaneously but in parallel. The separate parallelized analyses are linked by non-disclosive summary statistics and commands transmitted back and forth between the DCs and the AC. This paper describes the technical implementation of DataSHIELD using a modified R statistical environment linked to an Opal database deployed behind the computer firewall of each DC. Analysis is controlled through a standard R environment at the AC. Based on this Opal/R implementation, DataSHIELD is currently used by the Healthy Obese Project and the Environmental Core Project (BioSHaRE-EU) for the federated analysis of 10 data sets across eight European countries, and this illustrates the opportunities and challenges presented by the DataSHIELD approach. DataSHIELD facilitates important research in settings where: (i) a co-analysis of individual-level data from several studies is scientifically necessary but governance restrictions prohibit the release or sharing of some of the required data, and/or render data access unacceptably slow; (ii) a research group (e.g. in a developing nation) is particularly vulnerable to loss of intellectual property-the researchers want to fully share the information held in their data with national and international collaborators, but do not wish to hand over the physical data themselves; and (iii) a data set is to be included in an individual-level co-analysis but the physical size of the data precludes direct transfer to a new site for analysis

Transplantation of skin-derived precursor cells into neonatal rat brain

We have isolated a novel source of stem cells derived from the dermis of either rodent or human skin. When induced to differentiate in vitro, these cells give rise to all types of neuronal lineages. In this study, we therefore investigated if naive S̲ḵin-derived P̲recursor (SKPs) cells could be neuralized by the neonatal brain environment thereby generating neural cells in vivo. We transplanted orange cell tracker-labelled mouse SKPs into the lateral cerebral ventricule and the hippocampus of neonatal rats. Analysis of the transplants revealed that SKPs survived over the short, medium and long-term in vivo, with SKPs remaining viable for up to 6 weeks without forming tumors. Many cells also adopted a branched morphology, but, based on immunocytochemistry of orange cell tracker-labelled SKPs with specific markers for either neurons or glia, these morphologically complex cells did not differentiate into specific neuronal cell types. In control experiments, neural stem cells exhibited a similar in vivo pattern of survival and a lack of differentiation, thereby validating our results and that our transplantation protocol required further refinement in order to give optimal results. In conclusion, we have shown that SKPs can survive in vivo and do not appear to form neural lineages

Role de la GTPase RhoE dans la fusion des myoblastes et leur transformation

Les GTPases de la famille Rho sont impliquées dans de nombreux processus physiologiques comme la différenciation musculaire squelettique ou myogenèse, mais également dans la transformation cellulaire lorsqu'elles sont dérégulées. Nous avons montré que l'expression d'un membre atypique de cette famille, RhoE, est induite lors de la myogenèse, jusqu'à un maximum atteint au moment de la fusion des myoblastes en myotubes, avant de retrouver son niveau basal. Nous avons mis en évidence, par interférence ARN, que son extinction inhibe cette étape de fusion, à cause de défauts d'alignement et d'élongation des myoblastes. D'un point de vue mécanistique, RhoE participe à ce processus par la régulation négative des activités de la GTPase RhoA et de son effecteur la kinase ROCK1, deux évènements indispensables pour que la fusion ait lieu. Cette inhibition est médiée à la fois par l'activation de la protéine p190RhoGAP, qui inactive RhoA en favorisant l'hydrolyse du GTP, et également par une interaction directe avec la kinase ROCK1. Dans un deuxième temps, nous avons observé que l'expression de RhoE est fortement diminuée dans des lignées de rhabdomyosarcomes (RMS) et dans des myoblastes surexprimant la R-cadhérine, un marqueur de cette pathologie qui conduit à leur transformation via l'activation de la GTPase Rac1. L'inhibition de son activité permet d'ailleurs une restauration des niveaux de RhoE. De plus, nous avons pu montrer que cette diminution d'expression participe à l'acquisition du pouvoir invasif des cellules de RMS, phénomène qui est largement diminué lorsqu'on réexprime RhoE. L'utilisation, sur les cellules de RMS, de drogues inhibant respectivement RhoA ou ROCK1 conduit à une diminution de l'invasion cellulaire, suggérant qu'une fois de plus RhoE contrôle cette propriété en régulant les activités de RhoA et de son effecteur ROCK1Rho family GTPases are involved in various physiological processes, such as skeletal muscle differentiation, also called myogenesis, and, when they are misregulated, in cellular transformation. We have shown that the expression of an atypical member of the family, RhoE, is induced during myogenesis up to a maximum at fusion time, before resuming its basal level. Then, we report that its extinction by RNA interference blocked the fusion process because of myoblast alignment and elongation defects. Mechanistically, RhoE negatively regulates the activities of the GTPase RhoA and of its effector, the kinase ROCK1, which must be downregulated to allow myoblast fusion. This inhibition is mediated by the activation of p190RhoGAP, which enhances GTP hydrolysis by RhoA and also by direct interaction with ROCK1. Secondly, we observed that RhoE expression is strongly downregulated in rhabdomyosarcoma cell lines and in R-cadherin-expressing myoblasts. R-cadherin induces their transformation via the activation of Rac1 GTPase. Inhibition of Rac1 activity allows a rescue of RhoE level. Moreover, we have shown that this decrease participates in invasive properties of RMS cell lines. Conversely, this process is lost when we express exogenous RhoE in these cells. By using drugs that target selectively RhoA or ROCK1, we observed a decrease of invasiveness, meaning that RhoE controls this property by downregulating the activities of RhoA and its effector ROCK1MONTPELLIER-BU Sciences (341722106) / SudocSudocFranceF

Les Buts institutionnels : rapport d'étape /

Titre de la couv.La couv. porte en outre: Dossie

Mobilité et sédentarité : stratégies familiales en Nouvelle-France

Les travaux récents sur la mobilité géographique en Nouvelle-France orientent l'attention du chercheur vers l'échelle individuelle du phénomène migratoire. Les facteurs de provenance locale ou régionale restent secondaires par rapport aux situations familiales et aux liens de parenté dans le processus initial de peuplement à partir de la France.L'essaimage de proche en proche dans la vallée du Saint-Laurent répond aussi, en partie, à des stratégies familiales visant à l'établissement des enfants en surnombre. Le modèle se reproduit au XVIIIe siècle dans l'établissement des Canadiens au pays des Illinois. À côté du mythe de l'aventure s'impose une autre facette du monde rural en Nouvelle-France : la mobilité de la sédentarité

Le droit des affaires pharmaceutiques : vers une caractérisation d’une lex pharmaceutica ?

International audienceL’ouvrage, constitué des actes du colloque organisé sur le thème, vise à s’interroger sur les spécificités avérées ou naissantes d’un droit des affaires commun à l’ensemble du monde de l’entreprise, lorsqu’il est en prise avec un secteur caractérisé par ses enjeux particuliers (la santé publique) et ses règlementations abondantes. Les différents droits impliqués ­—droit commercial, droit des sociétés, droit des contrats, droit de la concurrence, droit des investissements, etc.— connaissent ainsi des adaptations, voire des transformations plus profondes qui peuvent mettre en évidence un droit des affaires particulier, adapté au domaine des médicaments, notamment à celui de l’industrie pharmaceutique. Mais ce droit n’aurait pas pour seule origine les États (droit national ou international constitué des traités qu’ils concluent entre eux), mais potentiellement aussi les acteurs privés : d’où l’idée de la recherche de l’existence d’une Lex pharmaceutica, entendons d’un droit spontané né de la pratique même de ces opérateurs, s’inscrivant dans les recherches déjà menées par le CREDIMI dans d’autres domaines (droit du sport, droit des activités spatiales, droit des énergies renouvelables, etc.). L’industrie pharmaceutique est-elle cependant en mesure, malgré les contraintes provenant d’une réglementation publique forte, de développer son propre droit spontané des affaires (de la pratique contractuelle à la résolution des litiges, en passant par la protection du savoir-faire) ?A travers l’étude de la production des normes, mais aussi de la résolution des litiges (par les modes alternatifs de règlement des différends notamment), se dessine une complémentarité — État/opérateurs privés, droit national/normes internationales— qui pourrait s’avérer plus efficace que le droit étatique seul sur le plan de la qualité, de la sécurité et de l’accès aux traitements tout en satisfaisant les intérêts industriels des acteurs