2,707 research outputs found

    Structural and functional analyses of the shedding protease ADAM17 in HoxB8-Immortalized macrophages and dendritic-like cells

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    A disintegrin and metalloproteinase (ADAM) 17 has been implicated in many shedding processes. Major substrates of ADAM17 are TNF-α, IL-6R, and ligands of the epidermal growth factor receptor. The essential role of the protease is emphasized by the fact that ADAM17 deficiency is lethal in mice. To study ADAM17 function in vivo, we generated viable hypomorphic ADAM17 mice called ADAM17ex/ex mice. Recent studies indicated regulation of proteolytic ADAM17 activity by cellular processes such as cytoplasmic phosphorylation and removal of the prodomain by furin cleavage. Maturation and thus activation of ADAM17 is not fully understood. So far, studies of ADAM17 maturation have been mainly limited to mouse embryonic fibroblasts or transfected cell lines relying on nonphysiologic stimuli such as phorbol esters, thus making interpretation of the results difficult in a physiologic context. In this article, we present a robust cell system to study ADAM17 maturation and function in primary cells of the immune system. To this end, HoxB8 conditionally immortalized macrophage precursor cell lines were derived from bone marrow of wild-type and hypomorphic ADAM17ex/ex mice, which are devoid of measurable ADAM17 activity. ADAM17 mutants were stably expressed in macrophage precursor cells, differentiated to macrophages under different growth factor conditions (M-CSF versus GM-CSF), and analyzed for cellular localization, proteolytic activity, and podosome disassembly. Our study reveals maturation and activity of ADAM17 in a more physiological-immune cell system. We show that this cell system can be further exploited for genetic modifications of ADAM17 and for studying its function in immune cells

    Lung Cancer in Pulmonary Fibrosis: Tales of Epithelial Cell Plasticity

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    Lung epithelial cells exhibit a high degree of plasticity. Alterations to lung epithelial cell function are critically involved in several chronic lung diseases such as pulmonary fibrosis. Pulmonary fibrosis is characterized by repetitive injury and subsequent impaired repair of epithelial cells, which leads to aberrant growth factor activation and fibroblast accumulation. Increased proliferation and hyper- and metaplasia of epithelial cells upon injury have also been observed in pulmonary fibrosis; this epithelial cell activation might represent the basis for lung cancer development. Indeed, several studies have provided histopathological evidence of an increased incidence of lung cancer in pulmonary fibrosis. The mechanisms involved in the development of cancer in pulmonary fibrosis, however, remain poorly understood. This review highlights recently uncovered molecular mechanisms shared between lung cancer and fibrosis, which extend the current evidence of a common trait of cancer and fibrosis, as provided by histopathological observations. Copyright (C) 2011 S. Karger AG, Base

    Microbial ligand costimulation drives neutrophilic steroid-refractory asthma

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    Funding: The authors thank the Wellcome Trust (102705) and the Universities of Aberdeen and Cape Town for funding. This research was also supported, in part, by National Institutes of Health GM53522 and GM083016 to DLW. KF and BNL are funded by the Fonds Wetenschappelijk Onderzoek, BNL is the recipient of an European Research Commission consolidator grant and participates in the European Union FP7 programs EUBIOPRED and MedALL. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Peer reviewedPublisher PD

    Over-calcified forms of the coccolithophore Emiliania huxleyi in high-CO2 waters are not preadapted to ocean acidification

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    Marine multicellular organisms inhabiting waters with natural high fluctuations in pH appear more tolerant to acidification than conspecifics occurring in nearby stable waters, suggesting that environments of fluctuating pH hold genetic reservoirs for adaptation of key groups to ocean acidification (OA). The abundant and cosmopolitan calcifying phytoplankton Emiliania huxleyi exhibits a range of morphotypes with varying degrees of coccolith mineralization. We show that E. huxleyi populations in the naturally acidified upwelling waters of the eastern South Pacific, where pH drops below 7.8 as is predicted for the global surface ocean by the year 2100, are dominated by exceptionally over-calcified morphotypes whose distal coccolith shield can be almost solid calcite. Shifts in morphotype composition of E. huxleyi populations correlate with changes in carbonate system parameters. We tested if these correlations indicate that the hyper-calcified morphotype is adapted to OA. In experimental exposures to present-day vs. future pCO2 (400 vs. 1200 µatm), the over-calcified morphotypes showed the same growth inhibition (−29.1±6.3 %) as moderately calcified morphotypes isolated from non-acidified water (−30.7±8.8 %). Under the high-CO2–low-pH condition, production rates of particulate organic carbon (POC) increased, while production rates of particulate inorganic carbon (PIC) were maintained or decreased slightly (but not significantly), leading to lowered PIC ∕ POC ratios in all strains. There were no consistent correlations of response intensity with strain origin. The high-CO2–low-pH condition affected coccolith morphology equally or more strongly in over-calcified strains compared to moderately calcified strains. High-CO2–low-pH conditions appear not to directly select for exceptionally over-calcified morphotypes over other morphotypes, but perhaps indirectly by ecologically correlated factors. More generally, these results suggest that oceanic planktonic microorganisms, despite their rapid turnover and large population sizes, do not necessarily exhibit adaptations to naturally high-CO2 upwellings, and this ubiquitous coccolithophore may be near the limit of its capacity to adapt to ongoing ocean acidification

    Shorter Telomeres May Mark Early Risk of Dementia: Preliminary Analysis of 62 Participants from the Nurses' Health Study

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    Background: Dementia takes decades to develop, and effective prevention will likely require early intervention. Thus, it is critical to identify biomarkers of preclinical disease, allowing targeting of high-risk subjects for preventive efforts. Since telomeres shorten with age and oxidative stress both of which are important contributors to the onset of dementia, telomere length might be a valuable biomarker. Methodology/Principal Findings: Among 62 participants of the Nurses' Health Study,we conducted neurologic evaluations, including patient and caregiver interviews physical exam, neurologic exam and neuropsychologic testing. We also conducted magnetic resonance imaging (MRI) in a sample of 29 of these women. In these preliminary data, after adjustment for numerous health and lifestyle factors, we found that truncated telomeres in peripheral blood leukocytes segregate with preclinical dementia states, including mild cognitive impairment (MRI); the odds of MCI were 12 fold higher (odds ratio = 12.00, 95% confidence interval 1.24-116.5) for those with shorter telomere length compared to longer telomere length. In addition, decreasing telomere length was strongly related to decreasing hippocampal volume (p=0.038). Conclusions: These preliminary data suggest that telomere length may be a possible early marker of dementia risk, and merits further study in large, prospective investigations

    Aruskipawinaka 5 - secundaria : cuaderno de trabajo - Comunicación 5° - Aimara

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    Los cuadernos de trabajo de Comunicación elaborados para el nivel secundaria tienen el propósito de desarrollar las competencias comunicativas en la lengua originaria, fortalecer la identidad con su lengua y pueblo, además ampliar sus conocimientos a otros pueblos desde una postura crítica y reflexiva de los estudiantes de los pueblos originarios

    Leadership and quality in Higher Education

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    En la Universidad del Siglo XXI, la función de liderazgo está en la base de los procesos de surgimiento, mantenimiento e institucionalización de una nueva cultura de la calidad (Fernández Cruz, 2015). En este contexto, las universidades han creado unas Unidades de Calidad como responsables de los procesos de acreditación, seguimiento y renovación de títulos que deben actuar como verdaderos impulsores de unas acciones de mejora para las que resulta indispensable la puesta en marcha de procesos de evaluación y seguimiento que exigen el ejercicio de un liderazgo que fomente una cultura de calidad que impregne el quehacer diario de la institución. Los nuevos Títulos de Grado establecidos dentro del Espacio Europeo de Educación Superior demandan una serie de actuaciones que deben ser ejecutadas por los llamados Coordinadores de Grado como responsables de la coordinación de los equipos docentes. Además de lo anterior, el proceso de internacionalización que conlleva el Espacio Europeo de Educación Superior supone el desarrollo de estrategias de liderazgo a nivel interno, que se han traducido hacia el exterior en un fuerte liderazgo institucional (Cleveland-Innes, 2012; Juárez- Casalengua, 2015), y en un impulso y liderazgo político e institucional de la UE.In the 21st century university, the leadership function is at the base of the processes of emergence, maintenance and institutionalization of a new culture of quality (Fernández Cruz, 2015). In this context, the universities have created Quality Units to facilitate the process of accreditation, monitoring and renewal official degrees. This units must act as real drivers of improvement for which it is essential implement assessment and monitoring procedures that require a leadership that foster a culture quality in the daily activities of the institution. The new official degrees established under European Higher Education Area demand a series of actions that must be carried out by the so-called Degree Coordinators as responsible for the coordination of the teaching teams. In addition to the above, the internationalization that entails the European Higher Education Area implies the development of internal leadership strategies that have been turned into strong institutional leadership (Cleveland-Innes, 2012; Juárez-Casalengua, 2015), and in an impetus and political and institutional leadership of the EU. On the other hand, as most of the research on leadership has traditionally focused on managerial positions, we have wanted to approach from an alternative perspective the leadership function exercised by university students through the different representation positions they perform

    Constraints on the χ_(c1) versus χ_(c2) polarizations in proton-proton collisions at √s = 8 TeV

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    The polarizations of promptly produced χ_(c1) and χ_(c2) mesons are studied using data collected by the CMS experiment at the LHC, in proton-proton collisions at √s=8  TeV. The χ_c states are reconstructed via their radiative decays χ_c → J/ψγ, with the photons being measured through conversions to e⁺e⁻, which allows the two states to be well resolved. The polarizations are measured in the helicity frame, through the analysis of the χ_(c2) to χ_(c1) yield ratio as a function of the polar or azimuthal angle of the positive muon emitted in the J/ψ → μ⁺μ⁻ decay, in three bins of J/ψ transverse momentum. While no differences are seen between the two states in terms of azimuthal decay angle distributions, they are observed to have significantly different polar anisotropies. The measurement favors a scenario where at least one of the two states is strongly polarized along the helicity quantization axis, in agreement with nonrelativistic quantum chromodynamics predictions. This is the first measurement of significantly polarized quarkonia produced at high transverse momentum
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