PT - JOURNAL ARTICLE AU - Colucci, Rocchina AU - Antonioli, Luca AU - Bernardini, Nunzia AU - Ippolito, Chiara AU - Segnani, Cristina AU - Awwad, Oriana AU - Tuccori, Marco AU - Blandizzi, Corrado AU - Scarpignato, Carmelo AU - Fornai, Matteo TI - NSAID Activated Gene (NAG-1) plays a role in the impairing effects of cyclooxygenase inhibitors on gastric ulcer healing AID - 10.1124/jpet.111.190116 DP - 2012 Jan 01 TA - Journal of Pharmacology and Experimental Therapeutics PG - jpet.111.190116 4099 - http://jpet.aspetjournals.org/content/early/2012/04/10/jpet.111.190116.short 4100 - http://jpet.aspetjournals.org/content/early/2012/04/10/jpet.111.190116.full AB - Non-steroidal anti-inflammatory drugs (NSAIDs) can impair gastric ulcer healing. This study investigates the involvement of NSAID-activated gene-1 (NAG-1) in ulcer repair impairment by cyclooxygenase (COX) inhibitors. Gastric ulcers were induced in rats by acetic acid. Four days later, animals received daily intragastric indomethacin (non-selective COX-1/COX-2 inhibitor, 1 mg/kg), SC-560 (selective COX-1 inhibitor, 2.5 mg/kg), DFU (selective COX-2 inhibitor, 5 mg/kg), celecoxib (selective COX-2 inhibitor, 1 mg/kg) and valdecoxib (selective COX-2 inhibitor, 1 mg/kg), for 1, 3 or 7 days. Ulcerated tissues were processed to assess: 1) COX-1, COX-2, NAG-1, proliferating cell nuclear antigen (PCNA) and activated caspase-3 expression; 2) ulcer area; 3) prostaglandin E2. COX-1 expression in ulcerated tissues was decreased, while COX-2 expression was enhanced. Ulcer healing was delayed by indomethacin, DFU and SC-560, but not by celecoxib and valdecoxib. Ulcer PGE2 levels were decreased by SC-560, DFU, celecoxib, valdecoxib and indomethacin. NAG-1 was over-expressed in ulcerated tissues, and further enhanced by indomethacin, DFU and SC-560, but not by celecoxib or valdecoxib. PCNA expression in ulcerated areas was reduced by indomethacin, but not by other test drugs. The expression of activated caspase-3 in ulcers was increased, and enhanced further by indomethacin, DFU or SC-560, but not by celecoxib or valdecoxib. These findings indicate that: 1) COX inhibitors exert differential impairing effects on gastric ulcer healing, through mechanisms unrelated to the inhibition of COX isoforms and prostaglandin production; 2) NAG-1 induction, followed by activation of proapoptotic pathways, can contribute to the impairing effects of COX inhibitors on ulcer healing