1. Cyclooxygenase 2 is a key enzyme for inflammatory cytokine-induced angiogenesis.
- Author
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Kuwano, Takashi, Nakao, Shintaro, Yamamoto, Hidetaka, Tsuneyoshi, Masazumi, Yamamoto, Tomoya, Kuwano, Michihiko, and Ono, Mayumi
- Subjects
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CYCLOOXYGENASES , *CYCLOOXYGENASE 2 , *ARACHIDONIC acid , *MESSENGER RNA , *PROTEINS , *CYTOKINES , *INTERLEUKIN-1 , *TUMOR necrosis factors , *PROSTANOIDS , *VASCULAR endothelial growth factors , *PROTEIN-tyrosine kinases , *NEOVASCULARIZATION - Abstract
Cyclooxygenasel (COX1) and COX2 mediate the rate-limiting step in arachidonic acid metabolism. Expression of COX2 mRNA and protein is often enhanced in various human cell types by inflammatory cytokines such as interleukin-1β (IL-1β) and tumor necrosis factor α (TNFα). IL-1β enhanced expression of various prostanoids and this expression was blocked by COX2 selective inhibitors. IL-1β markedly induced angiogenesis in vitro and in vivo, which was significantly inhibited by COX2 selective inhibitors but not by a vascular endothelial growth factor (VEGF) receptor tyrosine kinase inhibitor. In contrast, COX2 selective inhibitors only partially blocked VEGF-induced angiogenesis. EP2, EP4 (prostaglandin E2 receptors) agonists and thromboxane A2 (TXA2) receptor agonists induced angiogenesis in vitro and in vivo; IL-1β-induced angiogenesis was blocked by an EP4 antagonist and a TXA2 receptor antagonist. IL-1β induced much less angiogenesis in cornea of COX2 knockout mice than that of wild-type mice. This is the first report that COX2 and some prostanoids play a key role in IL-1β-induced angiogenesis. [ABSTRACT FROM AUTHOR]
- Published
- 2004
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