Ca2+- and PKC-dependent stimulation of PGE2 synthesis by deoxycholic acid in human colonic fibroblasts.
We investigated prostanoid biogenesis by human colonic fibroblasts (CCD-18Co cells and nine primary fibroblast cultures) exposed to a primary (cholic, CA) or a secondary (deoxycholic, DCA) bile acid. Basal PGE2 levels in CCD-18Co cultures and fibroblast strains initiated from normal and adenocarcinomatous colon, respectively, were 1.7 +/- 0.3, 4.0 +/- 2.0, and 15.0 +/- 4.8 ng/mg protein. Peak levels 24 h after exposure to DCA (300 microM) rose, respectively, seven-, six- and sevenfold, but CA elicited no such responses. Increases in PGE2 synthesis were preceded by sequential increases in PGH synthase-2 mRNA and protein expression and were fully prevented by a nonselective (indomethacin) or a selective (celecoxib) nonsteroidal anti-inflammatory drug. DCA, but not CA, caused abrupt, transient increases in fibroblast intracellular Ca2+ concentration ([Ca2+]i) approximately 1 min after exposure. Increased [Ca2+]i was required for DCA-mediated induction of PGE2 synthesis, and protein kinase C was a further essential component of this signaling pathway. Colonic fibroblasts may be a major target for prostanoid biogenesis induced by fecal bile acids and, potentially, other noxious actions of these agents.
Department of Medicine, Veterans Affairs Medical Center, University at Buffalo, Buffalo, New York 14215, USA.
Yingting
Y
Zhu
Ping
P
Hua
Shazia
S
Rafiq
Eric J
EJ
Waffner
Michael E
ME
Duffey
Peter
P
Lance
D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000494:pharmacology; D002118:Calcium / Q000502:physiology*; D002460:Cell Line; D002470:Cell Survival; D003106:Colon / Q000166:cytology / Q000187:drug effects / Q000378:metabolism* / Q000502:physiology; D051546:Cyclooxygenase 2; D003840:Deoxycholic Acid / Q000494:pharmacology*; D015232:Dinoprostone / Q000037:antagonists & inhibitors / Q000096:biosynthesis*; D004790:Enzyme Induction / Q000187:drug effects; D005347:Fibroblasts / Q000187:drug effects / Q000378:metabolism*; D006801:Humans; D007425:Intracellular Membranes / Q000378:metabolism; D007527:Isoenzymes / Q000235:genetics / Q000378:metabolism; D008565:Membrane Proteins; D011451:Prostaglandin-Endoperoxide Synthases / Q000235:genetics / Q000378:metabolism; D011493:Protein Kinase C / Q000502:physiology*; D012333:RNA, Messenger / Q000378:metabolism
D000894:Anti-Inflammatory Agents, Non-Steroidal; D007527:Isoenzymes; D008565:Membrane Proteins; D012333:RNA, Messenger; D003840:Deoxycholic Acid; D051546:Cyclooxygenase 2; C496540:PTGS2 protein, human; D011451:Prostaglandin-Endoperoxide Synthases; D011493:Protein Kinase C; D015232:Dinoprostone; D002118:Calcium