Cyclooxygenase-1 and an alternatively spliced mRNA in the rat stomach: effects of aging and ulcers.
Prostaglandins play a critical role in gastric mucosal cytoprotection and decrease progressively with age. Cyclooxygenase (COX), the rate-limiting enzyme for prostaglandin synthesis, exists in two isoforms, COX-1 and COX-2. The rat COX-1 gene expresses an alternatively spliced mRNA COX-1 splice variant (SV) that may, at best, code for a truncated COX-1 protein. With the use of competitive PCR, we determined whether COX gene expression was altered in the stomach with increasing age and after gastric ulcer induction. COX-1 mRNA was significantly reduced in the aged, and COX-1SV mRNA was significantly higher in the adults compared with the young and aged stomach. Levels of COX-1 and COX-2 were similarly expressed in the normal stomach. In acute gastric ulcers, only COX-2 mRNA levels were significantly elevated. When ulcers were undergoing healing and repair, COX-1 and COX-2 mRNA levels were significantly elevated. Age-related changes in COX-1 and COX-1SV but not COX-2 mRNA may alter gastric mucosal cytoprotection. Furthermore, COX-1 and COX-2 may both contribute to the healing of a gastric ulcer.
Vogiagis
D
D
Department of Surgery, Monash University Medical School, Alfred Hospital, Prahran, Victoria 3181, Australia.
Glare
E M
EM
Misajon
A
A
Brown
W
W
O'Brien
P E
PE
D000375:Aging / Q000378:metabolism*; D017398:Alternative Splicing; D000818:Animals; D051545:Cyclooxygenase 1; D051546:Cyclooxygenase 2; D005091:Exons; D005753:Gastric Mucosa / Q000201:enzymology* / Q000254:growth & development; D015971:Gene Expression Regulation, Enzymologic; D007527:Isoenzymes / Q000235:genetics* / Q000378:metabolism; D008297:Male; D008565:Membrane Proteins; D016133:Polymerase Chain Reaction; D011451:Prostaglandin-Endoperoxide Synthases / Q000235:genetics* / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics; D051381:Rats; D017207:Rats, Sprague-Dawley; D013270:Stomach / Q000201:enzymology / Q000254:growth & development; D013276:Stomach Ulcer / Q000201:enzymology* / Q000235:genetics
D007527:Isoenzymes; D008565:Membrane Proteins; D012333:RNA, Messenger; D051545:Cyclooxygenase 1; D051546:Cyclooxygenase 2; D011451:Prostaglandin-Endoperoxide Synthases; C496513:Ptgs1 protein, rat