Stenfeldt A-L, Karlsson J, Wennerås C, Bylund J, Fu H, Dahlgren C
Department of Rheumatology and Inflammation Research, Göteborg University, Göteborg, Sweden.
Biochem Pharmacol. 2007 Oct 1;74(7):1050-6. doi: 10.1016/j.bcp.2007.06.049. Epub 2007 Jul 7.
The anti-inflammatory drug piroxicam has been reported to affect the production of reactive oxygen species in phagocytes. This anti-inflammatory effect is thought to be mediated through inhibition of cyclooxygenase (COX), an enzyme important for prostaglandin synthesis. We have compared the effects of piroxicam on superoxide production mediated by two closely related G-protein coupled receptors expressed on neutrophils, the formyl peptide receptor (FPR) and the formyl peptide receptor like 1 (FPRL1). Neutrophils were stimulated with agonists that bind specifically to FPR (the peptide ligand N-formyl-Met-Leu-Phe, fMLF) or FPRL1 (the peptide ligand Trp-Lys-Tyr-Met-Val-L-Met-NH(2), WKYMVM) or both of these receptors (the peptide ligand Trp-Lys-Tyr-Met-Val-D-Met-NH(2), WKYMVm). Piroxicam reduced the neutrophil superoxide production induced by the FPR agonist but had no significant effect on the FPRL1 induced response. Neutrophil intracellular calcium changes induced by the agonist WKYMVm (that triggers both FPR and FPRL1) were only inhibited by piroxicam when the drug was combined with the FPRL1 specific antagonist, Trp-Arg-Trp-Trp-Trp-Trp (WRW(4)), and this was true also for the inhibition of superoxide anion release. Receptor-binding analysis showed that the fluorescently labelled FPR specific ligand N-formyl-Nle-Leu-Phe-Nle-Tyr-Lys (fNLFNYK), was competed for in a dose-dependent manner, by the FPR ligand fMLF and as well as by piroxicam. We show that piroxicam inhibits the neutrophil responses triggered through FPR, but not through FPRL1 and this inhibition is due to a reduced binding of the activating ligand to its cell surface receptor.
据报道，抗炎药吡罗昔康会影响吞噬细胞中活性氧的产生。这种抗炎作用被认为是通过抑制环氧化酶（COX）介导的，COX是一种对前列腺素合成很重要的酶。我们比较了吡罗昔康对由中性粒细胞上表达的两种密切相关的G蛋白偶联受体介导的超氧化物产生的影响，即甲酰肽受体（FPR）和甲酰肽受体样1（FPRL1）。用特异性结合FPR的激动剂（肽配体N-甲酰基-蛋氨酸-亮氨酸-苯丙氨酸，fMLF）或FPRL1（肽配体色氨酸-赖氨酸-酪氨酸-蛋氨酸-缬氨酸-L-蛋氨酸-NH₂，WKYMVM）或这两种受体（肽配体色氨酸-赖氨酸-酪氨酸-蛋氨酸-缬氨酸-D-蛋氨酸-NH₂，WKYMVm）刺激中性粒细胞。吡罗昔康减少了FPR激动剂诱导的中性粒细胞超氧化物产生，但对FPRL1诱导的反应没有显著影响。激动剂WKYMVm（触发FPR和FPRL1）诱导的中性粒细胞细胞内钙变化仅在药物与FPRL1特异性拮抗剂色氨酸-精氨酸-色氨酸-色氨酸-色氨酸-色氨酸（WRW₄）联合使用时被吡罗昔康抑制，超氧阴离子释放的抑制也是如此。受体结合分析表明，荧光标记的FPR特异性配体N-甲酰基-Nle-亮氨酸-苯丙氨酸-Nle-酪氨酸-赖氨酸（fNLFNYK）被FPR配体fMLF以及吡罗昔康以剂量依赖性方式竞争。我们表明，吡罗昔康抑制通过FPR触发的中性粒细胞反应，但不抑制通过FPRL1触发的反应，这种抑制是由于激活配体与其细胞表面受体的结合减少。
