5-Hydroxytryptamine induces cyclooxygenase-2 in rat vascular smooth muscle cells: Mechanisms involving Src, PKC and MAPK activation [corrected].
Considering the importance of 5-hydroxytryptamine (5-HT) and cyclooxygenase (COX) products in vascular pathology, we investigated the effects of 5-HT on COX expression in rat vascular smooth muscle cells (VSMCs), and to provide mechanistic insights into these effects. VSMCs were enzymatically isolated from aortic media of Wistar rats. Incubation of VSMCs with 5-HT for 24h stimulated prostaglandin I(2) production, but this stimulation was completely suppressed by NS-398, a selective COX-2 inhibitor. 5-HT induced transient COX-2, but not COX-1, protein and mRNA expression in concentration- and time-dependent manners. This effect of 5-HT was completely inhibited by sarpogrelate, a 5-HT(2A) receptor antagonist. 5-HT-induced COX-2 expression was markedly blunted by Ca(2+) depletion; GF 109203X, a protein kinase C (PKC) inhibitor; PP2, an inhibitor of Src-family tyrosine kinase (Src); PD 98059, an inhibitor of extracellular signal-regulated kinase (ERK) activation; SB 203580, an inhibitor of p38 mitogen-activated protein kinase (MAPK); and SP 600125, an inhibitor of c-Jun N-terminal kinase (JNK). 5-HT activated ERK and p38 MAPK, followed by JNK activation. PP2 inhibited these activations, while GF 109203X inhibited only JNK activation. Furthermore, PD 98059 inhibited JNK activation. These results suggest that 5-HT induces COX-2 expression in rat VSMCs, and that PKC, Src, and MAPK activation are each essential for the full expression of COX-2 pathways.
Department of Pharmacological Sciences, School of Pharmaceutical Sciences, Health Sciences University of Hokkaido, Ishikari-Tobetsu, Hokkaido 061-0293, Japan.
Takuji
T
Machida
Misa
M
Ohta
Akina
A
Onoguchi
Kenji
K
Iizuka
Mio
M
Sakai
Masaru
M
Minami
Masahiko
M
Hirafuji
D000818:Animals; D002118:Calcium / Q000378:metabolism; D051546:Cyclooxygenase 2 / Q000235:genetics* / Q000378:metabolism*; D004789:Enzyme Activation / Q000187:drug effects; D011464:Epoprostenol / Q000096:biosynthesis; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D009131:Muscle, Smooth, Vascular / Q000166:cytology* / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism; D011493:Protein Kinase C / Q000378:metabolism*; D016392:Proto-Oncogene Proteins pp60(c-src) / Q000378:metabolism*; D051381:Rats; D044402:Receptor, Serotonin, 5-HT2A / Q000378:metabolism; D012701:Serotonin / Q000494:pharmacology*; D048051:p38 Mitogen-Activated Protein Kinases / Q000378:metabolism*
D044402:Receptor, Serotonin, 5-HT2A; D012701:Serotonin; D011464:Epoprostenol; D051546:Cyclooxygenase 2; D016392:Proto-Oncogene Proteins pp60(c-src); D011493:Protein Kinase C; D048051:p38 Mitogen-Activated Protein Kinases; D002118:Calcium