13 research outputs found
Identification and Characterization of a Critical CP2-binding Element in the Human Interleukin-4 Promoter
No full textSpecificities and Cell Distribution of Transcription Factors Binding To the Interleukin-4 (IL-4) Negative Regulatory Element (NRE)
No full textImpaired endothelial barrier function in apolipoprotein M-deficient mice is dependent on sphingosine-1-phosphate receptor 1
No full textApolipoprotein M (ApoM) transports sphingosine-1-phosphate (S1P) in plasma, and ApoM-deficient mice (Apom(-/-)) have ∼50% reduced plasma S1P levels. There are 5 known S1P receptors, and S1P induces adherens junction formation between endothelial cells through the S1P1 receptor, which in turn suppresses vascular leak. Increased vascular permeability is a hallmark of inflammation. The purpose of this study was to explore the relationships between vascular leakage in ApoM deficiency and S1P1 function in normal physiology and in inflammation. Vascular permeability in the lungs was assessed by accumulation of dextran molecules (70 kDa) and was increased ∼40% in Apom(-/-) mice compared to WT (C57Bl6/j) mice. Reconstitution of plasma ApoM/S1P or treatment with an S1P1 receptor agonist (SEW2871) rapidly reversed the vascular leakage to a level similar to that in WT mice, suggesting that it is caused by decreased plasma levels of S1P and reduced S1P1 stimulation. In a carrageenan-induced model of inflammation, Apom(-/-) mice had increased vascular leakage compared with that in WT mice. Adenoviral overexpression of ApoM in Apom(-/-) mice decreased the vascular leakage compared to adenoviral overexpression of green fluorescent protein. The study suggests that vascular leakage of albumin-sized particles in ApoM deficiency is S1P- and S1P1-dependent and this dependency exacerbates the response to inflammatory stimuli.-Christensen, P. M., Liu, C. H., Swendeman, S. L., Obinata, H., Qvortrup, K., Nielsen, L B., Hla, T., Di Lorenzo, A., Christoffersen, C. Impaired endothelial barrier function in apolipoprotein M-deficient mice is dependent on sphingosine-1-phosphate receptor 1.</p
Development and initial validation of the comprehensive HIV adherence with treatment scale
No full text2021 Spring.Includes bibliographical references.HIV remains a significant public health concern despite decreasing rates of transmission in the U.S. (Centers for Disease Control and Prevention, 2020c). Contributing factors include low rates of treatment adherence (de Bruin et al., 2010) and high rates of comorbidities with other medical and mental health conditions (Bing et al., 2001; Gallant et al., 2017; Lerner et al., 2020). Antiretroviral therapy (ART) has significantly improved HIV health outcomes and reduced AIDS diagnoses and AIDS-related mortality (Crum et al., 2006; Glass et al., 2008; Ickovics & Meade, 2002; Paterson et al., 2000; Stone, 2001; World Health Organization, 2015). Because of ART's effectiveness, HIV is considered a chronic rather than terminal health condition for people adherent with treatment (Aberg, 2006; Swendeman, Ingram, & Rotheram- Borus, 2009). Treatment for HIV as a chronic health condition includes several pro-health behaviors in addition to ART adherence to support overall wellness. To support future research and treatment recommendations, the current study developed a measure of adherence with pro- health behavior and conducted an initial analysis of the measure's psychometric properties with a sample of 118 people living with HIV. Structural equation modeling explored relations among antecedents (personality, treatment self-efficacy, treatment information, and treatment motivation) and health outcomes of pro-health behaviors and ART adherence. Regularly assessing engagement in, as well as antecedents and outcomes of, treatment behaviors can enhance communication between providers and people living with HIV, reinforce HIV's status as a manageable chronic condition, and link people living with HIV to appropriate interventions
ADAM33: a cellular model of over-expression. From full length to soluble
No full textPolymorphic variation in the A Disintegrin And Metalloprotease 33 (ADAM33) genehas been associated with asthma and bronchial hyperresponsiveness. The ADAMfamily of proteins has a multi-domain structure and has diverse biological functionswhich can include growth factor shedding, cell migration and cell adhesion.Evidence for a soluble form of ADAM33 has been found in BAL fluid of asthmaticpatients and there is evidence that ADAM33 has a function in angiogenesis.To determine the possible function(s) of the full length ADAM33 protein, it wasover expressed in HEK293 that do not normally express ADAM33 and thephenotypic consequences analyzed. Cells stably expressing full length ADAM33under the control of a CMV promoter were obtained by selection with the antibiotic,G418. The expression of ADAM33 was confirmed by western blot analysis. Controlcells were transfected with an empty vector control encoding G418 resistance only.Cells were examined for changes in cell phenotype and ability to produce solubleADAM33.Cells stably expressing ADAM33 grew more quickly than mock transfected cellsbut this effect was lost over time. However, processed (ie. active) ADAM33 proteincould not be detected by western blot. In order to determine whether asubpopulation of cells was able to produce active ADAM33, the cells were clonedand re-cloned by limiting dilution. This allowed isolation of a number of ADAM33clones that produced processed protein. Furthermore, these experiments revealedthat ADAM33 expression increased the clonogenic potential of the cells.Supernatant from cloned cells was pulled down with ConA and samples analysed bywestern blot which showed a band at 50-55kDa in the ADAM33 clones using anantibody to the metalloproteinase domain. This soluble ADAM33 was active andpromoted angiogenesis using a HUVEC capillary tube forming assay. SolubleADAM33 was upregulated in the presence of TGF-?2 and its shedding is unliky tobe autocatalytic.Over expression of ADAM33 in HEK293 cells alters the clonogenic potential andsurvival of HEK293 cells in low density cultures. This property may contribute tothe behaviour of mesenchymal cells in asthmatic airways. Soluble ADAM33 isreleased into culture media and has functional activity. Its release is up regulated inthe presence of TGF-?2
Migration of growth factor-stimulated epithelial and endothelial cells depends on EGFR transactivation by ADAM17
No full textThe fibroblast growth factor receptor 2-IIIb (FGFR2b) and the vascular endothelial growth factor receptor 2 (VEGFR2) are tyrosine kinases that can promote cell migration and proliferation and have important roles in embryonic development and cancer. Here we show that FGF7/FGFR2b-dependent activation of epidermal growth factor receptor (EGFR)/ERK1/2 signalling and cell migration in epithelial cells require stimulation of the membrane-anchored metalloproteinase ADAM17 and release of heparin-binding epidermal growth factor (HB-EGF). Moreover, VEGF-A/VEGFR2-induced migration of human umbilical vein endothelial cells also depends on EGFR/ERK1/2 signalling and shedding of the ADAM17 substrate HB-EGF. The pathway used by the FGF7/FGFR2b signalling axis to stimulate shedding of substrates of ADAM17, including ligands of the EGFR, involves Src, p38 mitogen-activated protein-kinase and PI3K, but does not require the cytoplasmic domain of ADAM17. Based on these findings, ADAM17 emerges as a central component in a triple membrane-spanning pathway between FGFR2b or VEGFR2 and EGFR/ERK1/2 that is required for cell migration in keratinocytes and presumably also in endothelial cells
Migration of growth factor-stimulated epithelial and endothelial cells depends on EGFR transactivation by ADAM17
No full textHDL-bound sphingosine 1-phosphate acts as a biased agonist for the endothelial cell receptor S1P1 to limit vascular inflammation.
No full textThe sphingosine 1-phosphate receptor 1 (S1P1) is abundant in endothelial cells, where it regulates vascular development and microvascular barrier function. In investigating the role of endothelial cell S1P1 in adult mice, we found that the endothelial S1P1 signal was enhanced in regions of the arterial vasculature experiencing inflammation. The abundance of proinflammatory adhesion proteins, such as ICAM-1, was enhanced in mice with endothelial cell-specific deletion of S1pr1 and suppressed in mice with endothelial cell-specific overexpression of S1pr1, suggesting a protective function of S1P1 in vascular disease. The chaperones ApoM(+)HDL (HDL) or albumin bind to sphingosine 1-phosphate (S1P) in the circulation; therefore, we tested the effects of S1P bound to each chaperone on S1P1 signaling in cultured human umbilical vein endothelial cells (HUVECs). Exposure of HUVECs to ApoM(+)HDL-S1P, but not to albumin-S1P, promoted the formation of a cell surface S1P1-β-arrestin 2 complex and attenuated the ability of the proinflammatory cytokine TNFα to activate NF-κB and increase ICAM-1 abundance. Although S1P bound to either chaperone induced MAPK activation, albumin-S1P triggered greater Gi activation and receptor endocytosis. Endothelial cell-specific deletion of S1pr1 in the hypercholesterolemic Apoe(-/-) mouse model of atherosclerosis enhanced atherosclerotic lesion formation in the descending aorta. We propose that the ability of ApoM(+)HDL to act as a biased agonist on S1P1 inhibits vascular inflammation, which may partially explain the cardiovascular protective functions of HDL
HDL activation of endothelial sphingosine-1-phosphate receptor-1 (S1P1) promotes regeneration and suppresses fibrosis in the liver
No full textRegeneration of hepatic sinusoidal vasculature is essential for non-fibrotic liver regrowth and restoration of its metabolic capacity. However, little is known about how this specialized vascular niche is regenerated. Here we show that activation of endothelial sphingosine-1-phosphate receptor-1 (S1P1) by its natural ligand bound to HDL (HDL-S1P) induces liver regeneration and curtails fibrosis. In mice lacking HDL-S1P, liver regeneration after partial hepatectomy was impeded and associated with aberrant vascular remodeling, thrombosis and peri-sinusoidal fibrosis. Notably, this "maladaptive repair" phenotype was recapitulated in mice that lack S1P1 in the endothelium. Reciprocally, enhanced plasma levels of HDL-S1P or administration of SEW2871, a pharmacological agonist specific for S1P1 enhanced regeneration of metabolically functional vasculature and alleviated fibrosis in mouse chronic injury and cholestasis models. This study shows that natural and pharmacological ligands modulate endothelial S1P1 to stimulate liver regeneration and inhibit fibrosis, suggesting that activation of this pathway may be a novel therapeutic strategy for liver fibrosis.</p
