Department of Pharmacological Sciences, School of Pharmaceutical Sciences, Health Sciences University of Hokkaido, Ishikari-Tobetsu, Hokkaido 061-0293, Japan.
Eur J Pharmacol. 2011 Apr 10;656(1-3):19-26. doi: 10.1016/j.ejphar.2010.12.044. Epub 2011 Jan 22.
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.
考虑到 5-羟色胺（5-HT）和环氧化酶（COX）产物在血管病理学中的重要性，我们研究了 5-HT 对大鼠血管平滑肌细胞（VSMCs）中 COX 表达的影响，并为这些影响提供了机制上的见解。VSMCs 是从 Wistar 大鼠主动脉中层酶解分离得到的。5-HT 孵育 VSMCs 24 小时可刺激前列腺素 I（2）的产生，但这一刺激可被选择性 COX-2 抑制剂 NS-398 完全抑制。5-HT 以浓度和时间依赖的方式诱导 COX-2 蛋白和 mRNA 的瞬时表达，但不是 COX-1。5-HT 的这种作用可被 5-HT（2A）受体拮抗剂沙格雷酯完全抑制。5-HT 诱导的 COX-2 表达明显减弱钙耗竭；蛋白激酶 C（PKC）抑制剂 GF 109203X；Src 家族酪氨酸激酶（Src）抑制剂 PP2；细胞外信号调节激酶（ERK）激活抑制剂 PD 98059；p38 丝裂原活化蛋白激酶（MAPK）抑制剂 SB 203580；和 c-Jun N 末端激酶（JNK）抑制剂 SP 600125。5-HT 激活 ERK 和 p38 MAPK，随后激活 JNK。PP2 抑制这些激活，而 GF 109203X 仅抑制 JNK 激活。此外，PD 98059 抑制 JNK 激活。这些结果表明，5-HT 诱导大鼠 VSMCs 中 COX-2 的表达，PKC、Src 和 MAPK 的激活对于 COX-2 途径的完全表达都是必不可少的。
