247 research outputs found

    Fermi Surface reconstruction in the CDW state of CeTe3 observed by photoemission

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    CeTe3 is a layered compound where an incommensurate Charge Density Wave (CDW) opens a large gap (400 meV) in optimally nested regions of the Fermi Surface (FS), whereas other sections with poorer nesting remain ungapped. Through Angle-Resolved Photoemission, we identify bands backfolded according to the CDW periodicity. They define FS pockets formed by the intersection of the original FS and its CDW replica. Such pockets illustrate very directly the role of nesting in the CDW formation but they could not be detected so far in a CDW system. We address the reasons for the weak intensity of the folded bands, by comparing different foldings coexisting in CeTe3

    Proresolving and cartilage-protective actions of resolvin D1 in inflammatory arthritis

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    Rheumatoid arthritis (RA) is a debilitating disease characterized by persistent accumulation of leukocytes within the articular cavity and synovial tissue. Metabololipidomic profiling of arthritic joints from omega-3 supplemented mice identified elevated levels of specialized proresolving lipid mediators (SPM) including resolvin D1 (RvD1). Profiling of human RA synovial fluid revealed physiological levels of RvD1, which - once applied to human neutrophils - attenuated chemotaxis. These results prompted analyses of the antiarthritic properties of RvD1 in a model of murine inflammatory arthritis. The stable epimer 17R-RvD1 (100 ng/day) significantly attenuated arthritis severity, cachexia, hind-paw edema, and paw leukocyte infiltration and shortened the remission interval. Metabololipidomic profiling in arthritic joints revealed 17R-RvD1 significantly reduced PGE2 biosynthesis, while increasing levels of protective SPM. Molecular analyses indicated that 17R-RvD1 enhanced expression of genes associated with cartilage matrix synthesis, and direct intraarticular treatment induced chondroprotection. Joint protective actions of 17R-RvD1 were abolished in RvD1 receptor-deficient mice termed ALX/fpr2/3-/- . These investigations open new therapeutic avenues for inflammatory joint diseases, providing mechanistic substance for the benefits of omega-3 supplementation in RA

    Targeting Extracellular Vesicles to the Arthritic Joint using a Damaged Cartilage Specific Antibody

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    The targeted delivery of therapies to diseased tissues offers a safe opportunity to achieve optimal efficacy whilst limiting systemic exposure. These considerations apply to many disease indications, but are especially relevant for rheumatoid arthritis (RA), as RA is a systemic autoimmune disease which affects multiple joints. We have identified an antibody that is specific to damaged arthritic cartilage (anti-ROS-CII) that can be used to deliver treatments specifically to arthritic joints, yielding augmented efficacy in experimental arthritis. In the current study, we demonstrate that scaffold enriched with bioactive payloads can be delivered precisely to an inflamed joint and achieve superior efficacy outcomes consistent with the pharmacological properties of these payloads. As a scaffold, we have used extracellular vesicles (EV) prepared from human neutrophils (PMN), which possess intrinsic anti-inflammatory properties and the ability to penetrate inflamed arthritic cartilage. EV fortified with anti-ROS-CII (EV/anti-ROS-CII) retained anti-ROS-CII specificity and bound exclusively to the damaged cartilage. Following systemic administration EV/anti-ROS-CII: a) exhibited the ability to localise specifically in the arthritic joint in vivo and b) was able to specifically target single (viral IL-10 or anti-TNF) or combined (viral IL-10 and anti-TNF) anti-inflammatory treatments to the arthritic joint, which accelerated attenuation of clinical and synovial inflammation. Overall, this study demonstrates the attainability of targeting a pro-resolving biological scaffold to the arthritic joint. The potential of targeting scaffolds such as EV, nanoparticles or combination thereof alongside combined therapeutics is paramount for designing systemically administered broad-spectrum of anti-inflammatory treatments

    13-Series resolvins mediate the leukocyte-platelet actions of atorvastatin and pravastatin in inflammatory arthritis

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    This work was supported by funding from the European Research Council under the European Union’s Horizon 2020 research and innovation program (Grant 677542), a Sir Henry Dale Fellowship jointly funded by the Wellcome Trust and the Royal Society (Grant 107613/Z/15/Z), and the Barts Charity (Grant MGU0343). This work was also funded, in part, by Medical Research Council Advance Course Masters (Grant MR/J015741/1). The authors declare no conflicts of interest

    Treatment of inflammatory arthritis via targeting of tristetraprolin, a master regulator of pro-inflammatory gene expression

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    Objectives Tristetraprolin (TTP), a negative regulator of many pro-inflammatory genes, is strongly expressed in rheumatoid synovial cells. The mitogen-activated protein kinase (MAPK) p38 pathway mediates the inactivation of TTP via phosphorylation of two serine residues. We wished to test the hypothesis that these phosphorylations contribute to the development of inflammatory arthritis, and that, conversely, joint inflammation may be inhibited by promoting the dephosphorylation and activation of TTP. Methods The expression of TTP and its relationship with MAPK p38 activity were examined in non-inflamed and rheumatoid arthritis (RA) synovial tissue. Experimental arthritis was induced in a genetically modified mouse strain, in which endogenous TTP cannot be phosphorylated and inactivated. In vitro and in vivo experiments were performed to test anti-inflammatory effects of compounds that activate the protein phosphatase 2A (PP2A) and promote dephosphorylation of TTP. Results TTP expression was significantly higher in RA than non-inflamed synovium, detected in macrophages, vascular endothelial cells and some fibroblasts and co-localised with MAPK p38 activation. Substitution of TTP phosphorylation sites conferred dramatic protection against inflammatory arthritis in mice. Two distinct PP2A agonists also reduced inflammation and prevented bone erosion. In vitro anti-inflammatory effects of PP2A agonism were mediated by TTP activation. Conclusions The phosphorylation state of TTP is a critical determinant of inflammatory responses, and a tractable target for novel anti-inflammatory treatments
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