6 research outputs found

    Tumor Necrosis Factor-Induced Neutrophil Adhesion Occurs Via Sphingosine Kinase-1-Dependent Activation of Endothelial α5β1 Integrin

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    Leukocyte recruitment plays a major role in the immune response to infectious pathogens, as well as during inflammatory and autoimmune disorders. The process of leukocyte extravasation from the blood requires a complex cascade of adhesive events between the leukocytes and the endothelium, including initial leukocyte rolling, adhesion, and finally transendothelial migration. Current research in this area aims to identify the key leukocyte subsets that initiate a given disease and to identify the trafficking molecule(s) that will most specifically inhibit those cells. Herein we demonstrate that tumor necrosis factor (TNF)α activates the integrin α5β1 without altering total expression levels of β1 integrin on human umbilical vein endothelial cells. Moreover, our studies suggest that TNFα-induced β1 activation is dependent on sphingosine kinase-1, but independent of the sphingosine-1-phosphate family of G protein-coupled receptors. We also show, using a parallel plate flow chamber assay, that neutrophil adhesion to TNFα-activated endothelium can be attenuated by blocking α5β1 or its ligand angiopoietin-2. These observations add new complexities that broaden the accepted concept of cellular trafficking with neutrophil adhesion to TNFα activated endothelial cells being sphingosine kinase-1, α5β1, and angiopoietin-2 dependent. Moreover, this work supports the notion that sphingosine kinase-1 may be the single target required for an effective broad spectrum approach to combat inflammation and immune disorders

    SARS-CoV2-mediated suppression of NRF2-signaling reveals potent antiviral and anti-inflammatory activity of 4-octyl-itaconate and dimethyl fumarate

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    Versiones preprint disponibles en: http://hdl.handle.net/10261/216920 y http://hdl.handle.net/10261/217161Antiviral strategies to inhibit Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV2) and the pathogenic consequences of COVID-19 are urgently required. Here, we demonstrate that the NRF2 antioxidant gene expression pathway is suppressed in biopsies obtained from COVID-19 patients. Further, we uncover that NRF2 agonists 4-octyl-itaconate (4-OI) and the clinically approved dimethyl fumarate (DMF) induce a cellular antiviral program that potently inhibits replication of SARS-CoV2 across cell lines. The inhibitory effect of 4-OI and DMF extends to the replication of several other pathogenic viruses including Herpes Simplex Virus-1 and-2, Vaccinia virus, and Zika virus through a type I interferon (IFN)-independent mechanism. In addition, 4-OI and DMF limit host inflammatory responses to SARS-CoV2 infection associated with airway COVID-19 pathology. In conclusion, NRF2 agonists 4-OI and DMF induce a distinct IFN-independent antiviral program that is broadly effective in limiting virus replication and in suppressing the pro-inflammatory responses of human pathogenic viruses, including SARS-CoV2.This research work was supported by Ester M og Konrad Kristian Sigurdssons Dyreværnsfond, Beckett-Fonden, Kong Christian IX og Dronning Louises Jubilæumslegat, Læge Sofus Carl Emil Friis og Hustru Olga Doris Friis´ legat, Købmand I Odense Johan og Hanne Weimann Født Seedorffs Legat, Hørslev Fonden, UK Medical Research Council (MRC core funding of the MRC Human Immunology Unit; JR), Lundbeck foundation (R303-2018-3379 and R219-2016-878, and R268-2016-3927), and Independent Research Fund Denmark – Medical Sciences (9039-00078B, 4004-00047B, and 0214-00001B). CarlsbergFoundation (Semper Ardens) and European Research Council (ERC-AdG ENVISION; 786602). Marie Skłodowska-Curie Action of the European Commission # 813343 and Italian Cancer Research Society #22891 to JH.Peer reviewe
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