92 research outputs found
Wnt4 and LAP2alpha as pacemakers of Thymic Epithelial Senescence
Age-associated thymic involution has considerable physiological impact by inhibiting de novo T-cell selection. This impaired T-cell production leads to weakened immune responses. Yet the molecular mechanisms of thymic stromal adipose involution are not clear. Age-related alterations also occur in the murine thymus providing an excellent model system. In the present work structural and molecular changes of the murine thymic stroma were investigated during aging. We show that thymic epithelial senescence correlates with significant destruction of epithelial network followed by adipose involution. We also show in purified thymic epithelial cells the age-related down-regulation of Wnt4 (and subsequently FoxN1), and the prominent increase in LAP2α expression. These senescence-related changes of gene expression are strikingly similar to those observed during mesenchymal to pre-adipocyte differentiation of fibroblast cells suggesting similar molecular background in epithelial cells. For molecular level proof-of-principle stable LAP2α and Wnt4-over-expressing thymic epithelial cell lines were established. LAP2α over-expression provoked a surge of PPARγ expression, a transcription factor expressed in pre-adipocytes. In contrast, additional Wnt4 decreased the mRNA level of ADRP, a target gene of PPARγ. Murine embryonic thymic lobes have also been transfected with LAP2α- or Wnt4-encoding lentiviral vectors. As expected LAP2α over-expression increased, while additional Wnt4 secretion suppressed PPARγ expression. Based on these pioneer experiments we propose that decreased Wnt activity and increased LAP2α expression provide the molecular basis during thymic senescence. We suggest that these molecular changes trigger thymic epithelial senescence accompanied by adipose involution. This process may either occur directly where epithelium can trans-differentiate into pre-adipocytes; or indirectly where first epithelial to mesenchymal transition (EMT) occurs followed by subsequent pre-adipocyte differentiation. The latter version fits better with literature data and is supported by the observed histological and molecular level changes
Role of CD248 as a potential severity marker in idiopathic pulmonary fibrosis
BACKGROUND: CD248 or Endosialin is a transmembrane molecule expressed in stromal cells binding to extracellular matrix (ECM) components. It has been previously implicated in kidney fibrosis, rheumatoid arthritis as well as in tumour-stromal interactions. This study investigates the role of CD248 in the pathogenesis of fibrotic diseases in Idiopathic Pulmonary Fibrosis (IPF). METHODS: CD248 quantitative immunohistochemistry (IHC) was performed on lung samples from 22 IPF patients and its expression was assayed in cultured pulmonary fibroblasts and epithelial cells. Effects of CD248 silencing was evaluated on fibroblast proliferation and myofibroblast differentiation. RESULTS: IHC revealed strong CD248 expression in mesenchymal cells of normal lung structures such as pleura and adventitia but not in epithelium. Fibrotic areas showed markedly stronger staining than unaffected lung tissue. The extent of CD248 staining showed a significant negative correlation to lung function parameters FEV1, FVC, TLC, and TLCO (r2 > 0 · 35, p < 0 · 01). CD248 protein levels were significantly greater in IPF-derived lung fibroblasts vs normal lung fibroblasts (p < 0 · 01) and CD248 silencing significantly reduced the proliferation of lung fibroblasts, but did not affected myofibroblast differentiation. CONCLUSION: We conclude that CD248 overexpression is possibly involved in the pathogenesis of IPF and it has potential as a disease severity marker. Given that CD248 ligands are collagen type I, IV and fibronectin, we hypothesise that CD248 signalling represents a novel matrix-fibroblast interaction that may be a potential therapeutic target in IPF. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12890-016-0211-7) contains supplementary material, which is available to authorized users
The HIBEAM program: search for neutron oscillations at the ESS
With the construction of the European Spallation Source, a remarkable
opportunity has emerged to conduct high sensitivity searches for neutron
oscillations, including a first search for thirty years for free neutrons
converting to antineutrons. Furthermore, searches can be made for transitions
of neutrons and antineutrons to sterile neutron states. The HIBEAM program
provides an increase in sensitivity of an order of magnitude compared to
previous work.
The HIBEAM program corresponds to baryon number violation by one and two
units. The observation of a process satisfying a Sakharov condition addresses
the open question of the origin of the matter-antimatter asymmetry in the
Universe. Sterile neutron states would belong to a `dark' sector of particles
which may explain dark matter. As electrically neutral, meta-stable objects
that can be copiously produced and studied, neutrons represent an attractive
portal to a `dark' sector.
This paper describes the capability, design, infrastructure, and potential of
the HIBEAM program. This includes a dedicated beamline, neutron optical system,
magnetic shielding and control, and detectors for neutrons and antineutrons.Comment: 41 pages, 12 figure
Vitamin D deficiency contributes directly to the acute respiratory distress syndrome (ARDS)
Rationale: Vitamin D deficiency has been implicated as a pathogenic factor in sepsis and intensive therapy unit mortality but has not been assessed as a risk factor for acute respiratory distress syndrome (ARDS). Causality of these associations has never been demonstrated. Objectives: To determine if ARDS is associated with vitamin D deficiency in a clinical setting and to determine if vitamin D deficiency in experimental models of ARDS influences its severity. Methods: Human, murine and in vitro primary alveolar epithelial cell work were included in this study. Findings: Vitamin D deficiency (plasma 25(OH)D levels 600 genes. In a clinical setting, pharmacological repletion of vitamin D prior to oesophagectomy reduced the observed changes of in vivo measurements of alveolar capillary damage seen in deficient patients. Conclusions: Vitamin D deficiency is common in people who develop ARDS. This deficiency of vitamin D appears to contribute to the development of the condition, and approaches to correct vitamin D deficiency in patients at risk of ARDS should be developed
Correlation between Tribological Properties, sp²/sp³-Ratio and H-Content of Low-Wear Diamond-Like Carbon (DLC) Layers
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Integrated coal preparation and CWF processing plant: Conceptual design and costing. Final technical report
At the request of the US Department of Energy (DOE), Pittsburgh Energy Technology Center, a study was conducted to provide DOE with a reliable, documented estimate of the cost of producing coal-water fuel (CWF). The approach to the project was to specify a plant capacity and location, identify and analyze a suitable coal, and develop a conceptual design for an integrated coal preparation and CWF processing plant. Using this information, a definitive costing study was then conducted, on the basis of which an economic and sensitivity analysis was performed utilizing a financial evaluation model to determine a price for CWF in 1992. The design output of the integrated plant is 200 tons of coal (dry basis) per hour. Operating at a capacity factor of 83 percent, the baseline design yields approximately 1.5 million tons per year of coal on a dry basis. This is approximately equivalent to the fuel required to continuously generate 500 MW of electric power. The CWF produced by the plant is intended as a replacement for heavy oil or gas in electric utility and large industrial boilers. The particle size distribution, particularly the top size, and the ash content of the coal in the CWF are specified at significantly lower levels than is commonly found in typical pulverized coal grinds. The particle top size is 125 microns (vs typically 300m{mu} for pulverized coal) and the coal ash content is 3.8 percent. The lower top size is intended to promote complete carbon burnout at less derating in boilers that are not designed for coal firing. The reduced mineral matter content will produce ash of very fine particle size during combustion, which leads to less impaction and reduced fouling of tubes in convective passages
Alteration in the Wnt microenvironment directly regulates molecular events leading to pulmonary senescence
In the aging lung, the lung capacity decreases even in the absence of diseases. The progenitor cells of the distal lung, the alveolar type II cells (ATII), are essential for the repair of the gas-exchange surface. Surfactant protein production and survival of ATII cells are supported by lipofibroblasts that are peroxisome proliferator-activated receptor gamma (PPARγ)-dependent special cell type of the pulmonary tissue. PPARγ levels are directly regulated by Wnt molecules; therefore, changes in the Wnt microenvironment have close control over maintenance of the distal lung. The pulmonary aging process is associated with airspace enlargement, decrease in the distal epithelial cell compartment and infiltration of inflammatory cells. qRT–PCR analysis of purified epithelial and nonepithelial cells revealed that lipofibroblast differentiation marker parathyroid hormone-related protein receptor (PTHrPR) and PPARγ are reduced and that PPARγ reduction is regulated by Wnt4 via a β-catenin-dependent mechanism. Using a human in vitro 3D lung tissue model, a link was established between increased PPARγ and pro-surfactant protein C (pro-SPC) expression in pulmonary epithelial cells. In the senile lung, both Wnt4 and Wnt5a levels increase and both Wnt-s increase myofibroblast-like differentiation. Alteration of the Wnt microenvironment plays a significant role in pulmonary aging. Diminished lipo- and increased myofibroblast-like differentiation are directly regulated by specific Wnt-s, which process also controls surfactant production and pulmonary repair mechanisms
Sociomateriality and information systems success and failure
The aim of this essay is to put forward a performative, sociomaterial perspective on Information Systems (IS) success and failure in organisations by focusing intently upon the discursive-material nature of IS development and use in practice. Through the application of Actor Network Theory (ANT) to the case of an IS that transacts insurance products we demonstrate the contribution of such a perspective to the understanding of how IS success and failure occur in practice. The manuscript puts our argument forward by first critiquing the existing perspectives on IS success and failure in the literature for their inadequate consideration of the materiality of IS, of its underling technologies and of the entanglement of the social and material aspects of IS development and use. From a sociomaterial perspective IS are not seen as objects that impact organisations one way or another, but instead as relational effects continually enacted in practice. As enactments in practice IS development and use produce realities of IS success and failure
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