Lipoxins and other eicosanoids display potent and selective biological effects on leukocytes. In this study, we utilized radiolabeled lipoxin A4 ([3H]LXA4) to investigate whether carrier-mediated transport of LXA4 might occur in human neutrophils. At a concentration of 5 nM, uptake of [3H]LXA4, above that due to specific binding to receptors, amounted to approximately 0.6 fmol.10(6) cells-1.min-1. This influx was sensitive to a number of anionic inhibitors, including 3,5-diiodosalicylic acid (K0.5 12 microM), pentachlorophenol (K0.5 25 microM), alpha-cyano-beta-(1-phenylindol-3-yl) acrylic acid, and the organomercurial agents mersalyl (K0.5 110 microM) and p-hydroxy-mercuribenzoate. Influx, which was Na+ and membrane voltage independent, exhibited a striking dependence on pH (negative log of dissociation 5.9), results compatible with an H+ + LXA4 anion cotransport system. The LXA4 carrier did not appear to interact with arachidonic acid, prostaglandin E2, 15(S)-hydroxy-(5Z,8Z,11Z,13E)-eicosatetraenoic acid, or the leukotrienes B4, C4, and D4. Moreover, transport activity was not observed in human erythrocytes, lymphocytes, or platelets, but it was inducible in HL-60 cells on differentiation by exposure to retinoic acid. These findings represent the identification and initial characterization of a novel carrier-mediated pathway in human neutrophils that facilitates transport of LXA4 into cells.
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http://dx.doi.org/10.1152/ajpcell.1994.267.6.C1525 | DOI Listing |
BMC Pulm Med
January 2025
Department of Key Laboratory of Ningxia Stem Cell and Regenerative Medicine, Institute of Medical Sciences, Department of Pulmonary and Critical Care Medicine, General Hospital of Ningxia Medical University, Yinchuan, Ningxia, 750004, China.
Background: In this study, we aimed to explore the association between baseline and early changes in the neutrophil-to-lymphocyte ratio (NLR) and the 30-day mortality rate in patients having anti-melanoma differentiation-associated gene 5 (MDA5)-positive dermatomyositis with interstitial lung disease (DM-ILD).
Methods: Overall, 263 patients with anti-MDA5 DM-ILD from four centers in China were analyzed. Multivariate logistic regression analysis was used to evaluate the impact of baseline NLR on the 30-day mortality rate in patients with anti-MDA5-positive DM-ILD.
Semin Immunopathol
January 2025
Institute for Clinical Chemistry and Laboratory Medicine, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Fetscherstrasse 74, 01307, Dresden, Germany.
Metabolic flexibility is key for the function of myeloid cells. Arginine metabolism is integral to the regulation of myeloid cell responses. Nitric oxide (NO) production from arginine is vital for the antimicrobial and pro-inflammatory responses.
View Article and Find Full Text PDFJ Cereb Blood Flow Metab
January 2025
KG Jebsen Centre for Brain Fluid Research, University of Oslo, Oslo, Norway.
A potential two-way passage of cells and substances between the brain and skull bone marrow may open for new insights into neurological disease. The arachnoid membrane was traditionally considered to restrict cells and larger molecules in CSF from entering the dura and bone marrow directly. However, new data on exchange between brain and skull bone marrow have recently emerged.
View Article and Find Full Text PDFFront Biosci (Landmark Ed)
January 2025
Institute of Translational Medicine, Shanghai University, 200444 Shanghai, China.
Background: Dexamethasone has proven life-saving in severe acute respiratory syndrome (SARS) and COVID-19 cases. However, its systemic administration is accompanied by serious side effects. Inhalation delivery of dexamethasone (Dex) faces challenges such as low lung deposition, brief residence in the respiratory tract, and the pulmonary mucus barrier, limiting its clinical use.
View Article and Find Full Text PDFBr J Hosp Med (Lond)
January 2025
Department of Obstetrics, Beilun District People's Hospital, Ningbo, Zhejiang, China.
Intrahepatic cholestasis of pregnancy (ICP) is associated with adverse perinatal outcomes, yet the correlation between ICP and the neutrophil-to-lymphocyte ratio (NLR) remains unclear. This study aims to investigate the diagnostic value of NLR in ICP. In this retrospective case-control study, 113 patients with ICP treated in Beilun District People's Hospital from January 2020 to December 2022 were recruited and categorized as the ICP group, and 209 healthy pregnant women treated during the same period were selected as the control group.
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