Nitric oxide induces HIF-1α stabilization and expression of intestinal trefoil factor in the damaged rat jejunum and modulates ulcer healing

• Published in: Journal of gastroenterology Vol. 46; no. 5; pp. 565 - 576
• Main Authors: Riaño, A., Ortiz-Masià, D., Velázquez, M., Calatayud, S., Esplugues, J. V., Barrachina, Maria Dolores
• Format: Journal Article
• Language: English
• Published: Japan Springer Japan 01.05.2011
• Subjects: Abdominal Surgery; Animals; Anti-Inflammatory Agents, Non-Steroidal - toxicity; Colorectal Surgery; Gastroenterology; Goblet Cells - metabolism; Hepatology; Hypoxia-Inducible Factor 1, alpha Subunit - metabolism; Imines - pharmacology; Immunoprecipitation; Indomethacin - toxicity; Intestinal Mucosa - metabolism; Jejunum - drug effects; Jejunum - pathology; Male; Medicine; Medicine & Public Health; Nitric Oxide - metabolism; Nitric Oxide Synthase Type II - metabolism; Original Article—Alimentary Tract; Peptic Ulcer - chemically induced; Peptic Ulcer - pathology; Peptides - metabolism; Rats; Rats, Sprague-Dawley; Surgical Oncology; Time Factors; Trefoil Factor-2; HIF-1; Nitrosylation; ITF; Indomethacin; Intestinal damage; Nitric oxide
• ISSN: 0944-1174; 1435-5922
• DOI: 10.1007/s00535-011-0374-1

Background The induction of intestinal trefoil factor (ITF) has been reported to depend on hypoxia-inducible factor-1 (HIF-1). Nitric oxide modulates HIF-1 activity. The present study aims to analyze the role of nitric oxide in jejunum damage induced by indomethacin and its ability to modulate epithelial function through the expression of ITF. Methods Rats received indomethacin (7.5 mg/kg, s.c., twice), and a time course analysis of damage was performed (24–96 h after the first administration). In these animals, the role of nitric oxide was analyzed by using 1400W, a selective iNOS activity inhibitor (5 mg/kg, i.p./day), on: (1) intestinal damage, (2) ulcer healing, (3) the presence of nitrated proteins in the jejunum and (4) the protein expression of inducible nitric oxide synthase (iNOS), HIF-1α and ITF. Results Indomethacin induced damage in the jejunum that was apparent at 24 h and peaked at 48–72 h. An increase in iNOS, HIF-1α, ITF and nitrated proteins was observed in the injured jejunum. Immunoprecipitation of HIF-1α allowed determination of the nitration/nitrosylation of this protein by using nitrotyrosine and nitrocysteine antibodies. Blockade of iNOS activity did not significantly modify damage or iNOS expression, but did significantly impede ITF induction, HIF-1α stabilization and HIF-1α detection with antibodies against nitrated proteins. In parallel to these results, pre-treatment with 1400W delayed the healing of the ulcer provoked by indomethacin. Conclusions These results suggest that iNOS-derived NO is involved in HIF-1α stabilization, probably through S-nitrosylation, and ITF expression in goblet cells of the damaged jejunum of indomethacin-treated rats and mediates ulcer healing.