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.
Zhu
Yingting
Y
Department of Medicine, Veterans Affairs Medical Center, University at Buffalo, Buffalo, New York 14215, USA.
Hua
Ping
P
Rafiq
Shazia
S
Waffner
Eric J
EJ
Duffey
Michael E
ME
Lance
Peter
P
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