815 research outputs found

    Hyaluronic acid of low molecular weight triggers the invasive “hummingbird” phenotype on gastric cancer cells

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    The overproduction and deposition of hyaluronic acid (HA) of different sizes in the tumor microenvironment is associated with cancer metastasis. Here, the development of layerâ byâ layer (LbL) constructs containing HA of different molecular weights (i.e., 5.6, 618, and 1450 kDa) that mimic the HAâ rich cancer extracellular matrix is described to study the effect of the HA's size on the behavior of gastric cancer cells (AGS). The results demonstrate that LbL constructs with short HA, i.e., 5.6 kDa, activate the cytoskeleton rearrangement leading to the â hummingbirdâ morphology, promote high cellular motility, and activate signaling pathways with increased expression of pâ ERK1/2 and pâ AKT. In addition, it is demonstrated that this malignant transformation involves an active participation of the HA coreceptor RHAMM in AGS cells.The authors acknowledge the financial support from the European Commission’s H2020 Programme, under grant agreements H2020-WIDESPREAD-2014-668983-FORECAST and H2020-MSCA-RISE-2019-872648-MEPHOS. S.A. acknowledge the Portuguese Foundation for Science and Technology (FCT) for the PhD grant (SFRH/BD/112075/2015). The authors also thank Ramon Novoa-Caballal for performing the GPC experiments and data analysis

    Horizontally and Vertically Aligned Polymeric Nanosheets: CO2-Induced Morphological Changes of Block Copolymer Thin Films

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    Recently, the carbon dioxide (CO2) Process with sphere forming block copolymer (bcp) templates successfully introduced nanometer cells into polymeric materials. CO2 selectively swells CO2-philic domains of fluorinated blocks and introduces nanometer voids in the CO2-philic domains. We extended the same methodology to bcp templates with nonspherical domains. Depending on the initial morphologies controlled by selectivity of casting solvents, vertically or horizontally aligned polymer nanosheets spontaneously appeared after the CO2 process and were confirmed by scanning electron microscopy and grazing incident small-angle X-ray scattering. Selective swelling of minority domains with CO2 induces transition to lamellar morphology during the process and results in stacking sheet structure after depressurization of CO2

    A 'resource allocator' for transcription based on a highly fragmented T7 RNA polymerase

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    Synthetic genetic systems share resources with the host, including machinery for transcription and translation. Phage RNA polymerases (RNAPs) decouple transcription from the host and generate high expression. However, they can exhibit toxicity and lack accessory proteins (σ factors and activators) that enable switching between different promoters and modulation of activity. Here, we show that T7 RNAP (883 amino acids) can be divided into four fragments that have to be co‐expressed to function. The DNA‐binding loop is encoded in a C‐terminal 285‐aa ‘σ fragment’, and fragments with different specificity can direct the remaining 601‐aa ‘core fragment’ to different promoters. Using these parts, we have built a resource allocator that sets the core fragment concentration, which is then shared by multiple σ fragments. Adjusting the concentration of the core fragment sets the maximum transcriptional capacity available to a synthetic system. Further, positive and negative regulation is implemented using a 67‐aa N‐terminal ‘α fragment’ and a null (inactivated) σ fragment, respectively. The α fragment can be fused to recombinant proteins to make promoters responsive to their levels. These parts provide a toolbox to allocate transcriptional resources via different schemes, which we demonstrate by building a system which adjusts promoter activity to compensate for the difference in copy number of two plasmids.United States. Office of Naval Research (N00014‐13‐1‐0074)National Institutes of Health (U.S.) (5R01GM095765)National Science Foundation (U.S.) (Synthetic Biology Engineering Research Center (SA5284‐11210))United States. Dept. of Defense (National Defense Science and Engineering Graduate Fellowship (NDSEG) Program))Hertz Foundation (Fellowship

    Rheumatoid synovial fluid interleukin-17-producing CD4 T cells have abundant tumor necrosis factor-alpha co-expression, but little interleukin-22 and interleukin-23R expression

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    Introduction\ud Th17 cells have been implicated in the pathogenesis of rheumatoid arthritis (RA). The aim of this study was to systematically analyse the phenotype, cytokine profile and frequency of interleukin-17 (IL-17) producing CD4-positive T cells in mononuclear cells isolated from peripheral blood, synovial fluid and synovial tissue of RA patients with established disease, and to correlate cell frequencies with disease activity. \ud \ud Methods\ud Flow cytometry was used to analyse the phenotype and cytokine production of mononuclear cells isolated from peripheral blood (PBMC) (n = 44), synovial fluid (SFMC) (n = 14) and synovium (SVMC) (n = 10) of RA patients and PBMC of healthy controls (n = 13). \ud \ud Results\ud The frequency of IL-17-producing CD4 T cells was elevated in RA SFMC compared with RA PBMC (P = 0.04). However, the frequency of this population in RA SVMC was comparable to that in paired RA PBMC. The percentage of IL-17-producing CD4 T cells coexpressing tumor necrosis factor alpha (TNFÎą) was significantly increased in SFMC (P = 0.0068). The frequency of IFNÎł-producing CD4 T cells was also significantly higher in SFMC than paired PBMC (P = 0.042). The majority of IL-17-producing CD4 T cells coexpressed IFNÎł. IL-17-producing CD4 T cells in RA PBMC and SFMC exhibited very little IL-22 or IL-23R coexpression. \ud \ud Conclusions\ud These findings demonstrate a modest enrichment of IL-17-producing CD4 T cells in RA SFMC compared to PBMC. Th17 cells in SFMC produce more TNFÎą than their PBMC counterparts, but are not a significant source of IL-22 and do not express IL-23R. However, the percentage of CD4 T cells which produce IL-17 in the rheumatoid joint is low, suggesting that other cells may be alternative sources of IL-17 within the joints of RA patients. \ud \u

    Fungal-derived cues promote ocular autoimmunity through a Dectin-2/Card9-mediated mechanism

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    This work was supported by National Institutes of Health (RO1 EY025250) and Intramural funding (NEI Project# EY00184), along with Department of Veterans Affairs Biomedical Laboratory Research & Development Service (Merit Review Award I01 BX002180) and Australian Research Council (F130101648). The authors thank Dr. Ruth J. Napier (VA Portland Health Care System & School of Medicine, Oregon Health & Science University, Portland, OR, USA) along with Dr. Tiffany Hughes and Anthony Smith (Immunology, Allergy & Arthritis, Flinders University School of Medicine) for their helpful discussions. We are also grateful to Rachel Penchoen-Lin at VA Portland Health Care System for her technical contributions.Peer reviewedPostprin
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