Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.5.4.4 (adenosine deaminase)
 5,136 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The effects of the carbocyclic nucleoside MDL 201,112 and the purine nucleoside adenosine on the interferon-gamma (IFN-gamma)-induced priming of macrophages (m phi s) for the respiratory burst and major histocompatibility class II (MHC class II) Ia+ antigen expression were compared. Priming of purified, peritoneal m phi s from Lewis (LEW/N) rats for 18 h with recombinant rat IFN-gamma (rRaIFN-gamma) in the presence of either adenosine (100 microM) or MDL 201,112 (10 microM) resulted in a fourfold decrease in superoxide anion (O2-) production after stimulation with opsonized zymosan. Both agents were effective even when added 2 or 4 h after rRaIFN-gamma treatment. Peritoneal m phi s from LEW/N rats stimulated with LPS/rRaIFN-gamma were observed to secrete immunoreactive and bioactive TNF-alpha over 18 h in vitro and this cytokine could be dose-dependently inhibited by MDL 201,112. MDL 201,112 did not bind to classical A1 or A2 receptors on rat brain homogenates. Physiological levels of adenosine deaminase, or treatment with the nucleoside transport inhibitor dipyridamole, reversed the effects of adenosine; however, these agents at physiological concentrations had little or no effect on the inhibition of O2- release mediated by MDL 201,112. Furthermore, incubation of LEW/N m phi s for 18 h in vitro with rRaIFN-gamma resulted in significant enhancement of MHC class II Ia+ antigen expression, and these levels could be blocked by nearly 50% by either MDL 201,112 (10 microM) or adenosine (100 microM). MDL 201,112 and adenosine were also effective in decreasing m phi opsonized zymosan-stimulated O2- levels and MHC class II Ia+ antigen expression in vivo. The effects of MDL 201,112 on the down-regulation of heat-killed M. tuberculosis-activated LEW/N m phi MHC class II Ia+ antigen expression in vitro appear to be mediated by a novel pathway, because there was no rank order of potency of ADO A1 or A2 agonist/antagonists (CCPA, NECA, XAC, or CPT) in our in vitro system. In summary, our data provide compelling evidence that immunoregulatory carbocyclic nucleoside analogues such as MDL 201,112 or adenosine appear to regulate LEW/N rat m phi activation through novel molecular mechanisms and may have important therapeutic implications for acute and chronic inflammatory diseases.
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PMID:Effect of the carbocyclic nucleoside analogue MDL 201,112 on inhibition of interferon-gamma-induced priming of Lewis (LEW/N) rat macrophages for enhanced respiratory burst and MHC class II Ia+ antigen expression. 807 90

Better understanding of the pathogenesis and treatment of primary systemic vasculitides (PSV) has led to the development of many potentially clinically relevant biomarkers. Genome-wide association studies have highlighted that MHC class II polymorphisms may influence the development of particular anti-neutrophil cytoplasmic antibody (ANCA) serotypes, but not the clinical phenotype of ANCA-associated vasculitis (AAV). Although ANCAs are overall poor biomarkers of disease activity, they may be useful for the prediction of flares of renal and/or pulmonary vasculitis. Moreover, patients with proteinase 3 (PR3)-AAV may respond better to rituximab than cyclophosphamide. Newer biomarkers of renal vasculitis in AAV include urinary soluble CD163, and may in the future reduce the requirement for renal biopsy. Better understanding of dysregulated neutrophil activation in AAV has led to the identification of novel biomarkers including circulating microparticles, and neutrophil extracellular traps (NETs), although their clinical utility has not yet been realised. Studies examining endothelial injury and repair responses have additionally revealed indices that may have utility as disease activity and/or prognostic biomarkers. Last, next-generation sequencing technologies are revealing monogenic forms of vasculitis, such as deficiency of adenosine deaminase type 2 (DADA2), and are profoundly influencing the approach to the diagnosis and treatment of vasculitis in the young.
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PMID:Vasculitis update: pathogenesis and biomarkers. 2878 84