95 research outputs found

    Integrin α2β1 Expression Regulates Matrix Metalloproteinase-1-Dependent Bronchial Epithelial Repair in Pulmonary Tuberculosis.

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    Pulmonary tuberculosis (TB) is caused by inhalation of Mycobacterium tuberculosis, which damages the bronchial epithelial barrier to establish local infection. Matrix metalloproteinase-1 plays a crucial role in the immunopathology of TB, causing breakdown of type I collagen and cavitation, but this collagenase is also potentially involved in bronchial epithelial repair. We hypothesized that the extracellular matrix (ECM) modulates M. tuberculosis-driven matrix metalloproteinase-1 expression by human bronchial epithelial cells (HBECs), regulating respiratory epithelial cell migration and repair. Medium from monocytes stimulated with M. tuberculosis induced collagenase activity in bronchial epithelial cells, which was reduced by ~87% when cells were cultured on a type I collagen matrix. Matrix metalloproteinase-1 had a focal localization, which is consistent with cell migration, and overall secretion decreased by 32% on type I collagen. There were no associated changes in the specific tissue inhibitors of metalloproteinases. Decreased matrix metalloproteinase-1 secretion was due to ligand-binding to the α2β1 integrin and was dependent on the actin cytoskeleton. In lung biopsies, samples from patients with pulmonary TB, integrin α2β1 is highly expressed on the bronchial epithelium. Areas of lung with disrupted collagen matrix showed an increase in matrix metalloproteinases-1 expression compared with areas where collagen was comparable to control lung. Type I collagen matrix increased respiratory epithelial cell migration in a wound-healing assay, and this too was matrix metalloproteinase-dependent, since it was blocked by the matrix metalloproteinase inhibitor GM6001. In summary, we report a novel mechanism by which α2β1-mediated signals from the ECM modulate matrix metalloproteinase-1 secretion by HBECs, regulating their migration and epithelial repair in TB

    Complex regulation of neutrophil-derived MMP-9 secretion in central nervous system tuberculosis.

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    BACKGROUND: Central nervous system tuberculosis (CNS-TB) may be fatal even with treatment. Neutrophils are the key mediators of TB immunopathology, and raised CSF matrix metalloproteinase-9 (MMP-9) which correlates to neutrophil count in CNS-TB is associated with neurological deficit and death. The mechanisms by which neutrophils drive TB-associated CNS matrix destruction are not clearly defined. METHODS: Human brain biopsies with histologically proven CNS-TB were stained for neutrophils, neutrophil elastase, and MMP-9. Neutrophil MMP-9 secretion and gene expression were analyzed using Luminex and real-time PCR. Type IV collagen degradation was evaluated using confocal microscopy and quantitative fluorescent assays. Intracellular signaling pathways were investigated by immunoblotting and chemical inhibitors. RESULTS: MMP-9-expressing neutrophils were present in tuberculous granulomas in CNS-TB and neutrophil-derived MMP-9 secretion was upregulated by Mycobacterium tuberculosis (M.tb). Concurrent direct stimulation by M.tb and activation via monocyte-dependent networks had an additive effect on neutrophil MMP-9 secretion. Destruction of type IV collagen, a key component of the blood-brain barrier, was inhibited by neutralizing neutrophil MMP-9. Monocyte-neutrophil networks driving MMP-9 secretion in TB were regulated by MAP-kinase and Akt-PI3 kinase pathways and the transcription factor NF-kB. TNFα neutralization suppressed MMP-9 secretion to baseline while dexamethasone did not. CONCLUSIONS: Multiple signaling paths regulate neutrophil-derived MMP-9 secretion, which is increased in CNS-TB. These paths may be better targets for host-directed therapies than steroids currently used in CNS-TB

    Membrane Type 1 Matrix Metalloproteinase Regulates Monocyte Migration and Collagen Destruction in Tuberculosis

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    Tuberculosis (TB) remains a global pandemic and drug resistance is rising. Multicellular granuloma formation is the pathological hallmark of Mycobacterium tuberculosis infection. The membrane type 1 matrix metalloproteinase (MT1-MMP or MMP-14) is a collagenase that is key in leukocyte migration and collagen destruction. In patients with TB, induced sputum MT1-MMP mRNA levels were increased 5.1-fold compared with matched controls and correlated positively with extent of lung infiltration on chest radiographs (r = 0.483; p < 0.05). M. tuberculosis infection of primary human monocytes increased MT1-MMP surface expression 31.7-fold and gene expression 24.5-fold. M. tuberculosis-infected monocytes degraded collagen matrix in an MT1-MMP-dependent manner, and MT1-MMP neutralization decreased collagen degradation by 73%. In human TB granulomas, MT1-MMP immunoreactivity was observed in macrophages throughout the granuloma. Monocyte-monocyte networks caused a 17.5-fold increase in MT1-MMP surface expression dependent on p38 MAPK and G protein-coupled receptor-dependent signaling. Monocytes migrating toward agarose beads impregnated with conditioned media from M. tuberculosis-infected monocytes expressed MT1-MMP. Neutralization of MT1-MMP activity decreased this M. tuberculosis network-dependent monocyte migration by 44%. Taken together, we demonstrate that MT1-MMP is central to two key elements of TB pathogenesis, causing collagen degradation and regulating monocyte migration

    Inventorying geological heritage in large territories : a methodological proposal applied to Brazil

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    An adequate management of geological heritage by national and regional authorities presupposes the existence of a solid geosites inventory. Unfortunately, this is not the case for many countries. Most often, there is no national inventory at all or the method and criteria used to assess geosites was not adequate. This paper makes an overview of the strengths and weaknesses of the most common procedures to produce a geosite inventory and proposes a methodology particularly adapted for large territories such as Brazil. Nevertheless, this methodological approach can be easily adapted to any other geographical or geological setting, promoting the characterization and conservation of the world's geological heritage.High Level Scholarship Programme of the European Union - Programme AlβanFundação para a Ciência e a Tecnologia (FCT)

    Conservation of geosites as a tool to protect geoheritage: the inventory of Ceará Central Domain, Borborema Province - NE/Brazil

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    The Ceará Central Domain, in the northern Borborema Province/NE Brazil, encompasses important geological records (geosites) which allow understanding a relevant period of the Earth’s evolution, mainly associated to Neoproterozoic Brazilian/Pan-African Cycle and West Gondwana amalgamation, besides Neoarchean to Ordovician records. The presented geoheritage inventory aims to characterise the geosites with scienti c relevance of Ceará Central Domain. By applying a method for large areas, the nal selection resulted in eight geological frameworks represented by 52 geosites documented in a single database. This is the rst step for a geoconservation strategy based on systematic inventories, statutory protection, geoethical behaviour and awareness about scienti c, educational and/or cultural relevance of geosites.We specially thank all experts that helped us with this inventory: Afonso Almeida, Carlos E.G. de Araújo, César Veríssimo, Christiano Magini, Clóvis Vaz Parente, Felipe G. Costa, Irani C. Mattos, Neivaldo de Castro, Otaciel de Melo, Sebástian G. Chiozza, Ticiano Santos and Stefano Zincone. We are also thankful to Kátia Mansur, Ricardo Fraga Pereira and anonymous reviewers for their valuable contributions. PM is grateful to Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) for PhD mobility scholarship PDSE Program/Process n 88881.132168/2016-01info:eu-repo/semantics/publishedVersio

    Hypoxia and tissue destruction in pulmonary TB.

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    BACKGROUND: It is unknown whether lesions in human TB are hypoxic or whether this influences disease pathology. Human TB is characterised by extensive lung destruction driven by host matrix metalloproteinases (MMPs), particularly collagenases such as matrix metalloproteinase-1 (MMP-1). METHODS: We investigated tissue hypoxia in five patients with PET imaging using the tracer [18F]-fluoromisonidazole ([18F]FMISO) and by immunohistochemistry. We studied the regulation of MMP secretion in primary human cell culture model systems in normoxia, hypoxia, chemical hypoxia and by small interfering RNA (siRNA) inhibition. RESULTS: [18F]FMISO accumulated in regions of TB consolidation and around pulmonary cavities, demonstrating for the first time severe tissue hypoxia in man. Patlak analysis of dynamic PET data showed heterogeneous levels of hypoxia within and between patients. In Mycobacterium tuberculosis (M.tb)-infected human macrophages, hypoxia (1% pO2) upregulated MMP-1 gene expression 170-fold, driving secretion and caseinolytic activity. Dimethyloxalyl glycine (DMOG), a small molecule inhibitor which stabilises the transcription factor hypoxia-inducible factor (HIF)-1α, similarly upregulated MMP-1. Hypoxia did not affect mycobacterial replication. Hypoxia increased MMP-1 expression in primary respiratory epithelial cells via intercellular networks regulated by TB. HIF-1α and NF-κB regulated increased MMP-1 activity in hypoxia. Furthermore, M.tb infection drove HIF-1α accumulation even in normoxia. In human TB lung biopsies, epithelioid macrophages and multinucleate giant cells express HIF-1α. HIF-1α blockade, including by targeted siRNA, inhibited TB-driven MMP-1 gene expression and secretion. CONCLUSIONS: Human TB lesions are severely hypoxic and M.tb drives HIF-1α accumulation, synergistically increasing collagenase activity which will lead to lung destruction and cavitation.Medical Research CouncilThis is the final version of the article. It first appeared from the British Medical Journal via https://doi.org/10.1136/thoraxjnl-2015-20740

    An Airport Experience Framework from a Tourism Perspective

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    This study, by integrating the perspectives of sociological, psychological, and service marketing and management, all of which affect the passenger experience, proposes a theoretical framework for the creation of the airport experience in relation to tourism. This research responds to the current phenomenon in which airports are offering other types of experiences within the airport terminal, expanding the role of an airport from being a utility for transportation into a place where various and different values can be offered. This research explores the current airport experience and adds to research on airport experience by clarifying ten key components necessary for airport passenger experience propositions based on existing research, the current industry phenomena, and the empirical study. The paper also underlines those components that can enhance passenger experience in relation to tourism and highlights the role that airports contribute to a destination

    A new methodological contribution for the geodiversity assessment: applicability to Ceará State (Brazil)

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    The concept of geodiversity aggregates the abiotic elements of nature and promotes the geoconservation. The main objective of this work is to contribute to the upgrade of the method for the assessment and quantification of geodiversity proposed by Pereira et al. (2013). The method is based on the superposition of a regular grid of 12 × 12 km on different maps (lithology, geomorphology, soil, paleonthology, mineral and geological energy resources) at scales of 1:250,000 to 1:600,000. In addition to other up- grades, the water resources are regarded here as a new com- ponent to consider when quantifying geodiversity. The sum of these maps generated the quantitative Map of Geodiversity Indices and the Map of Geodiversity Assessment, ranging from very low to very high geodiversity. The analysis of the geodiversity map of the State of Ceará (Brazil) shows the applicability and advantage of this method, highlighting two regions with higher levels of geodiversity (Northwest and South) and another region with the lowest levels (Sertões Cearenses). The results also allowed the characterization of the State of Ceará concerning the individual components of the geodiversity, especially the water resources. Geodiversity indices and maps are comprehensive and user-friendly data in the territorial planning, considering the geodiversity either as a whole, or each of its components, especially the more sensi- tive such as fossil conservation, and water, mineral, and non- renewable energy resources management.The authors express their gratitude to the Brazilian research fostering institution "Coordenação de Aperfeiçoamento de Pessoal de Nível Superior" (CAPES) for awarding the Ciência Sem Fronteiras (CsF) PhD scholarship that enabled this work. This work was partially co-funded by the European Union through the European Regional Development Fund, based on COMPETE 2020 (Programa Operacional da Competitividade e Internacionalização), project ICT (UID/GEO/04683/ 2013) with reference POCI-01-0145-FEDER-007690 and national funds provided by Fundação para a Ciência e Tecnologia

    The granite and glacial landscapes of the Peneda-Gerês National Park

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    Granite and glacial landforms are presented as the main geomorphological landscape features of the Peneda-Gerês National Park. The park was established in 1971 and it is the only national park and most important protected area in Portugal. The aesthetic attractiveness is supported mainly by the distinct granite landscape of the Gerês and Peneda Mountains, where the post-orogenic Variscan Gerês gran- ite facies occurs. The rugged relief is poorly covered by vegetation, differentiating it from the surrounding moun- tainous areas and the most distinctive landforms are bornhardts, locally named as “medas”. Typical glacial landforms, such as U-shaped valleys, cirques and moraines, express the sheltered character of a low-altitude glaciation, which is of great significance in the context of the Pleistocene glaciation in Southern Europe.This work is co-funded by the European Union through the European Regional Development Fund, based on COMPETE 2020 (Programa Operacional da Competitividade e Inter nacionalização), project ICT (UID/GEO/04683/2013) with reference POCI-01-0145- FEDER-007690 and Portuguese national funds pro vided by Fundação para a Ciência e Tecnologi

    Geodiversity assessment of Paraná state (Brazil): an innovative approach

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    Geodiversity is considered as the natural range of geological, geomorphological, and soil features, including their assemblages, relationships, properties, interpretations, and systems. A method developed for the quantitative assessment of geodiversity was applied to Parana ́ , a Brazilian state with an area of about 200,000 km2. The method is based on the overlay of a grid over different maps at scales ranging from 1/500,000 to 1/650,000, with the final Geodiversity Index the sum of five partial indexes calculated on a 25 9 25 km grid. The partial indexes represent the main components of geodi- versity, including geology (stratigraphy and lithology), geomorphology, paleontology, and soils. The fifth partial index covers mineral occurrences of geodiversity, such precious stones and metals, energy and industrial minerals, mineral waters, and springs. The Geodiversity Index takes the form of an isoline map that can be used as a tool in land-use planning, particularly in identifying priority areas for conservation, management, and use of natural resources at the state level.The Portuguese authors express their gratitude for the financial support given by the Fundacao para a Ciencia e a Tecnologia to the Centro de Geologia da Universidade do Porto, which partially supports this research. The Brazilian author expresses his gratitude for the financial support given by the CNPq (Conselho Nacional de Desenvolvimento Cientifico e Tecnologico) (Process Number 200074/2011-3)
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