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Publicações

Publicações por LIAAD

2015

Short term exposure of beta cells to low concentrations of interleukin-1ß improves insulin secretion through focal adhesion and actin remodeling and regulation of gene expression

Autores
Arous, C; Ferreira, PG; Dermitzakis, ET; Halban, PA;

Publicação
Journal of Biological Chemistry

Abstract
Type 2 diabetes involves defective insulin secretion with islet inflammation governed in part by IL-1ß. Prolonged exposure of islets to high concentrations of IL-1ß (>24 h, 20 ng/ml) impairs beta cell function and survival. Conversely, exposure to lower concentrations of IL-1ß for >24 h improves these same parameters. The impact on insulin secretion of shorter exposure times to IL-1ßand the underlying molecular mechanisms are poorly understood and were the focus of this study. Treatment of rat primary beta cells, as well as rat or human whole islets, with 0.1 ng/ml IL-1ß for 2 h increased glucose-stimulated (but not basal) insulin secretion, whereas 20 ng/ml was without effect. Similar differential effects of IL-1ß depending on concentration were observed after 15 min of KCl stimulation but were prevented by diazoxide. Studies on sorted rat beta cells indicated that the enhancement of stimulated secretion by 0.1 ng/ml IL-1ß was mediated by the NF-ßB pathway and c-JUN/JNK pathway acting in parallel to elicit focal adhesion remodeling and the phosphorylation of paxillin independently of upstream regulation by focal adhesion kinase. Because the beneficial effect of IL-1ß was dependent in part upon transcription, gene expression was analyzed by RNAseq. There were 18 genes regulated uniquely by 0.1 but not 20 ng/ml IL-1ß, which are mostly involved in transcription and apoptosis. These results indicate that 2h of exposure of beta cells to a low but not a high concentration of IL-1ß enhances glucose-stimulated insulin secretion through focal adhesion and actin remodeling, as well as modulation of gene expression. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

2015

Corrigendum: Sporadic and reversible chromothripsis in chronic lymphocytic leukemia revealed by longitudinal genomic analysis

Autores
Bassaganyas, L; Beà, S; Escaramís, G; Tornador, C; Salaverria, I; Zapata, L; Drechsel, O; Ferreira, PG; Rodriguez Santiago, B; Tubio, JMC; Navarro, A; Martín García, D; López, C; Martínez Trillos, A; López Guillermo, A; Gut, M; Ossowski, S; López Otín, C; Campo, E; Estivill, X;

Publicação
Leukemia

Abstract

2015

Molecular signatures of plastic phenotypes in two eusocial insect species with simple societies

Autores
Patalano, S; Vlasova, A; Wyatt, C; Ewels, P; Camara, F; Ferreirab, PG; Asher, CL; Jurkowski, TP; Segonds Pichon, A; Bachman, M; Gonzalez Navarrete, I; Minoche, AE; Krueger, F; Lowy, E; Marcet Houben, M; Rodriguez Ales, JL; Nascimento, FS; Balasubramanian, S; Gabaldon, T; Tarver, JE; Andrews, S; Himmelbauer, H; Hughes, WOH; Guigo, R; Reik, W; Sumner, S;

Publicação
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA

Abstract
Phenotypic plasticity is important in adaptation and shapes the evolution of organisms. However, we understand little about what aspects of the genome are important in facilitating plasticity. Eusocial insect societies produce plastic phenotypes from the same genome, as reproductives (queens) and nonreproductives (workers). The greatest plasticity is found in the simple eusocial insect societies in which individuals retain the ability to switch between reproductive and nonreproductive phenotypes as adults. We lack comprehensive data on the molecular basis of plastic phenotypes. Here, we sequenced genomes, microRNAs (miRNAs), and multiple transcriptomes and methylomes from individual brains in a wasp (Polistes canadensis) and an ant (Dinoponera quadriceps) that live in simple eusocial societies. In both species, we found few differences between phenotypes at the transcriptional level, with little functional specialization, and no evidence that phenotype-specific gene expression is driven by DNA methylation or miRNAs. Instead, phenotypic differentiation was defined more subtly by nonrandom transcriptional network organization, with roles in these networks for both conserved and taxon-restricted genes. The general lack of highly methylated regions or methylome patterning in both species may be an important mechanism for achieving plasticity among phenotypes during adulthood. These findings define previously unidentified hypotheses on the genomic processes that facilitate plasticity and suggest that the molecular hallmarks of social behavior are likely to differ with the level of social complexity.

2015

Detection of Additive Outliers in Poisson INAR(1) Time Series

Autores
Silva, ME; Pereira, I;

Publicação
MATHEMATICS OF ENERGY AND CLIMATE CHANGE

Abstract
Outlying observations are commonly encountered in the analysis of time series. In this paper a Bayesian approach is employed to detect additive outliers in order one Poisson integer-valued autoregressive time series. The methodology is informative and allows the identification of the observations which require further inspection. The procedure is illustrated with simulated and observed data sets.

2015

Semantically Enhancing Recommender Systems

Autores
Bettencourt, Nuno; Silva, Nuno; Barroso, Joao;

Publicação
Knowledge Discovery, Knowledge Engineering and Knowledge Management - 7th International Joint Conference, IC3K 2015, Lisbon, Portugal, November 12-14, 2015, Revised Selected Papers

Abstract
As the amount of content and the number of users in social relationships is continually growing in the Internet, resource sharing and access policy management is difficult, time-consuming and error-prone. Cross-domain recommendation of private or protected resources managed and secured by each domain’s specific access rules is impracticable due to private security policies and poor sharing mechanisms. This work focus on exploiting resource’s content, user’s preferences, users’ social networks and semantic information to cross-relate different resources through their meta information using recommendation techniques that combine collaborative-filtering techniques with semantics annotations, by generating associations between resources. The semantic similarities established between resources are used on a hybrid recommendation engine that interprets user and resources’ semantic information. The recommendation engine allows the promotion and discovery of unknownunknown resources to users that could not even know about the existence of those resources thus providing means to solve the cross-domain recommendation of private or protected resources. © Springer International Publishing AG 2016.

2015

Recommending Access Policies in Cross-domain Internet

Autores
Bettencourt, N; Silva, N; Barroso, J;

Publicação
KMIS 2015 - Proceedings of the International Conference on Knowledge Management and Information Sharing, part of the 7th International Joint Conference on Knowledge Discovery, Knowledge Engineering and Knowledge Management (IC3K 2015), Volume 3, Lisbon, Portugal, November 12-14, 2015

Abstract
As the amount of content and the number of users in social relationships is continually growing in the Internet, resource sharing and access policy management is difficult, time-consuming and error-prone. In order to aid users in the resource-sharing process, the adoption of an entity that recommends users with access policies for their resources is proposed, by the analysis of (i) resource content, (ii) user preferences, (iii) users' social networks, (iv) semantic information, (v) user feedback about recommendation actions and (vi) provenance/ traceability information gathered from action sensors. A hybrid recommendation engine capable of performing collaborative-filtering was adopted and enhanced to use semantic information. Such recommendation engine translates user and resources' semantic information and aggregates those with other content, using a collaborative filtering technique. Recommendation of access policies over resources promotes the discovery of known-unknown and unknown-unknown resources to other users that could not even know about the existence of such resources. Evaluation to such recommender system is performed.

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