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NSAIDs upregulate beta 2-integrin expression on human neutrophils through a calcium-dependent pathway
S Fiorucci1, L Santucci, R Gerli
1Dipartimento di Medicina Clinica, Patologia e Farmacologia, Università degli Studi di Perugia, Italy.
Alimentary Pharmacology & Therapeutics
|June 1, 1997
Summary
Non-steroidal anti-inflammatory drug (NSAID) use increases neutrophil adhesion in the stomach. Indomethacin upregulates Mac-1 expression via calcium and nitric oxide pathways, impacting neutrophil margination in NSAID-induced gastropathy.
Area of Science:
- Gastroenterology
- Immunology
- Pharmacology
Background:
- Neutrophil (PMN) margination in gastric microcirculation is key in NSAID-induced gastropathy.
- This process involves the upregulation of beta-2 integrins on PMN surfaces.
Purpose of the Study:
- To investigate indomethacin's modulation of Mac-1 expression in human PMNs.
- To examine indomethacin's effects on intracellular calcium ([Ca2+]i), protein kinase C, nitric oxide, and mitogen-associated protein kinase phosphorylation.
Main Methods:
- Human PMNs were isolated using Ficoll gradient centrifugation.
- Intracellular calcium ([Ca2+]i) was measured using fura-2.
- Mac-1 expression and PMN adhesion were assessed via flow cytometry.
Main Results:
- Indomethacin caused dose- and time-dependent upregulation of CD11b/CD18 (Mac-1) and PMN adhesion.
- Maximal Mac-1 upregulation occurred at 0.1mM indomethacin after 30 minutes; this was calcium-dependent.
- Indomethacin induced mitogen-associated protein kinase phosphorylation and increased nitric oxide production, superoxide generation, and PMN adherence.
Conclusions:
- Indomethacin-induced Mac-1 upregulation is mediated by intracellular calcium ([Ca2+]i) and nitric oxide.
- Phosphorylation of a 41-kDa mitogen-associated protein kinase is a novel NSAID target.
- These findings elucidate mechanisms contributing to indomethacin-induced gastric neutrophil margination.