Endorepellin remodels the endothelial transcriptome toward a pro-autophagic and pro-mitophagic gene signature.

Regulation of autophagy by proteolytically cleaved fragments of heparan sulfate proteoglycans is a novel and current research focus in tumor biology. Endorepellin is the C-terminal angiostatic fragment of the heparan sulfate proteoglycan perlecan and induces autophagy in endothelial cells. To further investigate this property, we used NanoString, a digital PCR platform for measuring pre-defined transcripts in biological samples to analyze a custom subset of 95 autophagy-related genes in human umbilical vein endothelial cells treated with ultrapure human recombinant endorepellin. We discovered an endorepellin-evoked pro-autophagic and pro-mitophagic gene expression signatures, which included two coordinately up-regulated mitochondrial-associated genes encoding the E3 ubiquitin protein ligase Parkin and the tumor suppressor mitostatin. Induction of both proteins required the tyrosine kinase activity of vascular endothelial growth factor receptor 2 (VEGFR2). Furthermore, we discovered that endorepellin evoked mitochondrial depolarization in endothelial cells via a specific interaction between its two proximal LG1/2 domains and VEGFR2. We also found that following loss of membrane potential, mitostatin and parkin interact and that mitostatin associates with the established Parkin receptor mitofusin-2. In conclusion, we have identified a critical role for endorepellin in remodeling the autophagic transcriptome and influencing mitochondrial homeostasis

El precio justo

El precio justoFil: Schinder, Alejandro Fabian. Fundación Instituto Leloir; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Bioquimicas de Buenos Aires; ArgentinaFil: Mongiat, Lucas Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Patagonia Norte. Instituto de Investigación En Biodiversidad y Medioambiente; Argentin

Analyse des pratiques en évaluation de programme : les éléments qui contribuent à formuler un jugement fondé

Grâce à son caractère indéniablement pratique ainsi qu'au développement de son corpus théorique, l'évaluation de programme s'est imposée à l'intérieur des diverses organisations chargées de la gestion des programmes éducatifs et sociaux. Paradoxalement, ce domaine est également périodiquement remis en question par les utilisateurs. Ils doutent de sa capacité à remplir ses fonctions premières, soit produire des jugements suffisamment crédibles pour être acceptés des clients et ainsi, guider les grandes orientations des programmes. Pour expliquer ce phénomène, Guba (1972) et Scriven (1995) avancent que ce serait une mauvaise application du processus spécifique à l'évaluation de programme qui nuirait à la formulation d'un jugement fondé. Leurs propos demeurant cependant de l'ordre des intuitions, la présente étude vise à approfondir la contribution de l'application du processus spécifique à l'évaluation de programme à la formulation d'un jugement fondé. Les pratiques telles que rapportées ou écrites à l'intérieur des rapports d'évaluation (40) sont ainsi analysées afin de cerner cette contribution. Plus précisément, cette étude poursuit les efforts investis au premier volet du projet de recherche (Hurteau et Houle, 2006) sur les pratiques évaluatives et appuie son corpus théorique sur l'apport de Scriven (1980), de Hurteau (1991), de Fournier (1995), de Stake (2004) et d'Arens (2006). Les résultats montrent que l 'Opérationnalisation de l'évaluation qui spécifie le type d'évaluation, les objectifs et/ou les questions d'évaluation n'est pas réalisée de manière systématique et présente des irrégularités au niveau de son utilisation. Ils révèlent également qu'il n'y a que la moitié des rapports étudiés qui ont su dépasser les évidences pour produire un jugement et qu'il y en a encore moins qui les nuancent par les limites ou forces du devis de l'évaluation. Ce constat met en doute la teneur même des rapports d'évaluation actuellement produits. Ces rapports constituent-ils réellement des évaluations ou sont-ils davantage de l'ordre d'une simple enquête? Ce constat s'ajoute au fait qu'aucun rapport n'explique la manière dont les déclarations ont été synthétisées pour construire le jugement et que plusieurs rapports émettent des recommandations qui dépassent la portée du type d'évaluation effectué. Enfin, les résultats suggèrent qu'il n'y aurait pas de relation significative entre l'application de la modélisation et la formulation d'un jugement fondé. Un examen plus qualitatif met toutefois en évidence que certains éléments de la modélisation, hormis ceux liés à l'Opérationnalisation de l'évaluation, peuvent être réinvestis à l'intérieur d'une argumentation pour convaincre ou dissuader du bien-fondé du jugement. Enfin, cette recherche cerne avec plus de précision le malaise touchant la connaissance et/ou application du processus spécifique à l'évaluation de programme et la formulation d'un jugement fondé dans le domaine de l'évaluation de programme. ______________________________________________________________________________ MOTS-CLÉS DE L’AUTEUR : Évaluation de programme, Logique de l'évaluation, Pratiques évaluatives, Jugement

Multiplex staining depicts the immune infiltrate in colitis-induced colon cancer model

Assessment of the host immune response pattern is of increasing importance as highly prognostic and diagnostic, in immune-related diseases and in some types of cancer. Chronic inflammation is a major hallmark in colon cancer formation, but, despite the extent of local inflammatory infiltrate has been demonstrated to be extremely informative, its evaluation is not routinely assessed due to the complexity and limitations of classical immunohistochemistry (IHC). In the last years, technological advance helped in bypassing technical limits, setting up multiplex IHC (mIHC) based on tyramide signal amplification (TSA) method and designing software suited to aid pathologists in cell scoring analysis. Several studies verified the efficacy of this method, but they were restricted to the analysis of human samples. In the era of translational medicine the use of animal models to depict human pathologies, in a more complete and complex approach, is really crucial. Nevertheless, the optimization and validation of this method to species other than human is still poor. We took advantage of Multispectral Imaging System to identify the immunoprofile of Dextran Sulphate Sodium (DSS)-treated mouse colon. We optimized a protocol to sequentially stain formalin fixed paraffin embedded murine colon samples for CD3, CD8a, CD4, and CD4R5B0 antigens. With this approach we obtained a detailed lymphocyte profile, while preserving the morphological tissue context, generally lost with techniques like gene expression profiling or flow cytometry. This study, comparing the results obtained by mIHC with immunophenotyping performed with cytofluorimetric and standard IHC methods validates the potentiality and the applicability of this innovative approach

Social isolation impairs active avoidance performance and decreases neurogenesis in the dorsomedial telencephalon of rainbow trout

Alterations in the social environment, such as isolating an individual that would normally live in a social group, can generate physiological responses that compromise an individual's capacity to learn. To investigate this, we tested whether social isolation impairs learning skills in the rainbow trout. We show that rainbow trout can achieve an active avoidance (AA) learning program with inter-individual variability. Moreover, c-Fos expression in dorsomedial telencephalon (Dm) correlates with the AA performance, indicating that this structure is involved in this cognitive task. Given that Dm participates in AA learning and this region is under plastic remodelling by addition of new-born neurons, we tested whether social isolation impinges on adult neurogenesis and, consequently, on the Dm cognitive outcome. Trout were reared for four weeks in control or isolated conditions. We found that social isolation diminished the percentage of adult-born neurons that are being incorporated into Dm network. Interestingly, the same isolation treatment also induced a severe deficit in the AA performance. Our results demonstrate a structure-to-function relationship between the Dm and the learning ability in an AA task, indicate that social isolation reduces the incorporation of adult-born neurons into Dm, and show that social isolation impairs the Dm-related cognitive function.Fil: Ausas, Maria Soledad. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; Argentina. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; ArgentinaFil: Mazzitelli Fuentes, Laura Soledad. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; Argentina. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; ArgentinaFil: Román, Fernanda Ruth. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; Argentina. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; ArgentinaFil: Crichigno, Sonia Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto Andino Patagónico de Tecnologías Biológicas y Geoambientales. Universidad Nacional del Comahue. Instituto Andino Patagónico de Tecnologías Biológicas y Geoambientales; ArgentinaFil: de Vincenti, Ana Paula. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Biología Celular y Neurociencia "Prof. Eduardo de Robertis". Universidad de Buenos Aires. Facultad de Medicina. Instituto de Biología Celular y Neurociencia; ArgentinaFil: Mongiat, Lucas Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; Argentina. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentin

Role of extracellular matrix in gastrointestinal cancer-associated angiogenesis

Gastrointestinal tumors are responsible for more cancer-related fatalities than any other type of tumors, and colorectal and gastric malignancies account for a large part of these diseases. Thus, there is an urgent need to develop new therapeutic approaches to improve the patients\u2019 outcome and the tumor microenvironment is a promising arena for the development of such treatments. In fact, the nature of the microenvironment in the different gastrointestinal tracts may significantly influence not only tumor development but also the therapy response. In particular, an important microenvironmental component and a potential therapeutic target is the vasculature. In this context, the extracellular matrix is a key component exerting an active effect in all the hallmarks of cancer, including angiogenesis. Here, we summarized the current knowledge on the role of extracellular matrix in affecting endothelial cell function and intratumoral vascularization in the context of colorectal and gastric cancer. The extracellular matrix acts both directly on endothelial cells and indirectly through its remodeling and the consequent release of growth factors. We envision that a deeper understanding of the role of extracellular matrix and of its remodeling during cancer progression is of chief importance for the development of new, more efficacious, targeted therapies

Promoter hypermethylation of HS3ST2, SEPTIN9 and SLIT2 combined with FGFR3 mutations as a sensitive/specific urinary assay for diagnosis and surveillance in patients with low or high-risk non-muscle-invasive bladder cancer

International audienceBackgroundNon-muscle-invasive bladder cancer (NMIBC) is a high incidence form of bladder cancer (BCa), where genetic and epigenetic alterations occur frequently. We assessed the performance of associating a FGFR3 mutation assay and a DNA methylation analysis to improve bladder cancer detection and to predict disease recurrence of NMIBC patients.MethodsWe used allele specific PCR to determine the FGFR3 mutation status for R248C, S249C, G372C, and Y375C. We preselected 18 candidate genes reported in the literature as being hypermethylated in cancer and measured their methylation levels by quantitative multiplex-methylation specific PCR. We selected HS3ST2, SLIT2 and SEPTIN9 as the most discriminative between control and NMIBC patients and we assayed these markers on urine DNA from a diagnostic study consisting of 167 NMIBC and 105 controls and a follow-up study consisting of 158 NMIBC at diagnosis time’s and 425 at follow-up time. ROC analysis was performed to evaluate the diagnostic accuracy of each assay alone and in combination.ResultsFor Diagnosis: Using a logistic regression analysis with a model consisting of the 3 markers’ methylation values, FGFR3 status, age and known smoker status at the diagnosis time we obtained sensitivity/specificity of 97.6 %/84.8 % and an optimism-corrected AUC of 0.96. With an estimated BCa prevalence of 12.1 % in a hematuria cohort, this corresponds to a negative predictive value (NPV) of 99.6 %. For Follow-up: Using a logistic regression with FGFR3 mutation and the CMI at two time points (beginning of the follow-up and current time point), we got sensitivity/specificity/NPV of 90.3 %/65.1 %/97.0 % and a corrected AUC of 0.84. We also tested a thresholding algorithm with FGFR3 mutation and the two time points as described above, obtaining sensitivity/specificity/NPV values of, respectively, 94.5 %/75.9 %/98.5 % and an AUC of 0.82.ConclusionsWe showed that combined analysis of FGFR3 mutation and DNA methylation markers on urine can be a useful strategy in diagnosis, surveillance and for risk stratification of patients with NMIBC. These results provide the basis for a highly accurate noninvasive test for population screening and allowing to decrease the frequency of cystoscopy, an important feature for both patient quality of life improvement and care cost reduction

Article a new epigenetic model to stratify glioma patients according to their immunosuppressive state

Gliomas are the most common primary neoplasm of the central nervous system. A promising frontier in the definition of glioma prognosis and treatment is represented by epigenetics. Further-more, in this study, we developed a machine learning classification model based on epigenetic data (CpG probes) to separate patients according to their state of immunosuppression. We considered 573 cases of low-grade glioma (LGG) and glioblastoma (GBM) from The Cancer Genome Atlas (TCGA). First, from gene expression data, we derived a novel binary indicator to flag patients with a favorable immune state. Then, based on previous studies, we selected the genes related to the immune state of tumor microenvironment. After, we improved the selection with a data-driven procedure, based on Boruta. Finally, we tuned, trained, and evaluated both random forest and neural network classifiers on the resulting dataset. We found that a multi-layer perceptron network fed by the 338 probes selected by applying both expert choice and Boruta results in the best performance, achieving an out-of-sample accuracy of 82.8%, a Matthews correlation coefficient of 0.657, and an area under the ROC curve of 0.9. Based on the proposed model, we provided a method to stratify glioma patients according to their epigenomic state