Hypoxia modulates human eosinophil function

<p>Abstract</p> <p>Background</p> <p>Eosinophils are involved in various inflammatory processes including allergic inflammation during which angiogenesis has been documented. Angiogenesis is most likely connected to the hypoxia which characterizes inflamed tissues. Eosinophils produce VEGF and are pro-angiogenic. However, to the best of our knowledge no study has been performed to verify the existence of a direct link between eosinophils, hypoxia and angiogenesis in allergic inflammation.</p> <p>Objective</p> <p>To characterize eosinophil function and angiogenic potential under hypoxic conditions.</p> <p>Methods</p> <p>Human peripheral blood eosinophils were cultured in normoxic or hypoxic conditions with or without cytokines. Viability and apoptosis were assessed by Annexin V/PI staining. Anti- or pro-apoptotic protein levels, HIF-1α levels and MAPK phosphorylation were analyzed by immunoblot analysis. Angiogenic mediator release was evaluated by ELISA.</p> <p>Results</p> <p>Hypoxic eosinophils were more viable than normoxic ones after up to three days. In addition in hypoxia, anti-apoptotic Bcl-XL protein levels increased more than pro-apoptotic Bax levels. Hypoxia increased VEGF and IL-8 release. In hypoxic eosinophils high levels of HIF-1α were observed, particularly in the presence of GM-CSF. MAPK, particularly ERK1/2 inhibitors, decreased hypoxia-mediated VEGF release and HIF-1α expression.</p> <p>Conclusion</p> <p>Eosinophils respond to hypoxia by up-regulation of survival and of some of their pro-angiogenic functions indicating a correlation between eosinophilic inflammation and angiogenesis.</p

Towards reference-aware FrameNet representations:Bridging generic and specific event knowledge

FrameNet (Baker et al., 2003) is a resource that encodes conceptual and linguistic knowledge in the form of frames: information packages defining word senses and semantic roles associated with a particular type of event, situation or concept. FrameNet is a rich resource for describing how events and situations can be conceptualized in language in different ways, but is limited by its focus on lexical semantics and lack of a notion of reference: a frame-semantic analysis of the event descriptions in (1) would tell us that both describe the same event type (i.e., a commercial transaction, conceptualized from two different perspectives), but not whether they in fact describe the same event token in the real world. (1) a. Yesterday, John sold Mary a book. b. A woman bought a novel in the shop. To address this limitation, we are currently developing a new FrameNet-based resource, comprising a lexical database, annotated corpus and a semantic parser, that is ‘referentially enriched’ in two ways: frame annotations are linked, on one hand, to referential information from an ontology of real-world event tokens, and on the other hand to truth-conditional meaning representations

Metabolic networking in Brunfelsia calycina petals after flower opening

Brunfelsia calycina flowers change colour from purple to white due to anthocyanin degradation, parallel to an increase in fragrance and petal size. Here it was tested whether the production of the fragrant benzenoids is dependent on induction of the shikimate pathway, or if they are formed from the anthocyanin degradation products. An extensive characterization of the events taking place in Brunfelsia flowers is presented. Anthocyanin characterization was performed using ultraperfomance liquid chromatography–quadrupole time of flight–tandem mass specrometry (UPLC-QTOF-MS/MS). Volatiles emitted were identified by headspace solid phase microextraction–gas chromatography–mass spectrometry (HS-SPME-GC-MS). Accumulated proteins were identified by 2D gel electrophoresis. Transcription profiles were characterized by cross-species hybridization of Brunfelsia cDNAs to potato cDNA microarrays. Identification of accumulated metabolites was performed by UPLC-QTOF-MS non-targeted metabolite analysis. The results include characterization of the nine main anthocyanins in Brunfelsia flowers. In addition, 146 up-regulated genes, 19 volatiles, seven proteins, and 17 metabolites that increased during anthocyanin degradation were identified. A multilevel analysis suggests induction of the shikimate pathway. This pathway is the most probable source of the phenolic acids, which in turn are precursors of both the benzenoid and lignin production pathways. The knowledge obtained is valuable for future studies on degradation of anthocyanins, formation of volatiles, and the network of secondary metabolism in Brunfelsia and related species

Review: Tissue remodeling and angiogenesis in asthma: the role of the eosinophil

This review covers the role of eosinophils in asthma-associated tissue remodeling and angiogenesis focusing on angiogenesis which is a recently discovered feature of asthma. In addition, novel directions for eosinophil-targeted/angiogenesis-targeted pharmacological intervention are discussed as new approaches in the treatment of asthma

Cold Forming of Al-TiB2 Composites Fabricated by SPS: A Computational Experimental Study

The mechanical response and failure of Al-TiB2 composites fabricated by Spark Plasma Sintering (SPS) were investigated. The effective flow stress at room temperature for different TiB2 particle volume fractions between 0% and 15% was determined using compression experiments on cylindrical specimens in conjunction with an iterative computational methodology. A different set of experiments on tapered specimens was used to validate the effective flow curves by comparing experimental force&ndash;displacement curves and deformation patterns to the ones obtained from the computations. Using a continuum damage mechanics approach, the experiments were also used to construct effective failure curves for each material composition. It was demonstrated that the fracture modes observed in the different experiments could be reproduced in the computations. The results show that increasing the TiB2 particle volume fraction to 10% results in an increase in material effective yield stress and a decrease in hardening. For a particle volume fraction of 15%, the effective yield stress decreases with no significant influence on the hardening slope. The ductility (workability) of the composite decreases with increasing particle volume fraction