Cyclic AMP-mediated inhibition of 5-lipoxygenase translocation and leukotriene biosynthesis in human neutrophils
Cyclic AMP-mediated inhibition of 5-lipoxygenase translocation and leukotriene biosynthesis in human neutrophils
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DOI：
10.1124/mol.62.2.250
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发表时间：
2002-08-01
影响因子：
3.6
通讯作者：
Borgeat, P
中科院分区：
文献类型：
--
作者：
Flamand, N;Surette, ME;Borgeat, P
5-脂氧合酶（5-LO）催化花生四烯酸转化为白三烯（LT）。在受刺激的人PMN中，5-LO的激活涉及钙、p38 MAP激酶（p38）磷酸化和5-LO从细胞质转运到含有5-LO激活蛋白（FLAP）的核膜。在本研究中，camp -升高剂如异丙肾上腺素、前列腺素E2、CGS-21680（一种腺苷A（2a）受体激动剂）、IV型磷酸二酯酶抑制剂RO 201724、腺苷酸环化酶激活剂forskolin和gs -蛋白激活剂霍乱毒素，在血小板活化因子刺激的细胞因子引发的人PMN和内膜Ca2+- atp酶阻滞剂thapsigargin刺激的人PMN中，都能抑制LT的生物合成和5-LO向细胞核的转运。此外，激活蛋白激酶A （PKA）的cAMP的单磷硫酸类似物也抑制了受刺激细胞中LT的生物合成和5-LO的易位。用CGS-21680处理PMN也可以阻止p38被thapsigargin磷酸化。用PKA抑制剂H-89和KT-5720处理PMN可以阻止camp升高剂对LT生物合成、5-LO易位和p38磷酸化的抑制作用，而p38抑制剂SB 203,580则可以剂量依赖性地抑制花生四烯酸诱导的LT生物合成。在所有实验条件下，FLAP拮抗剂MK-0591也能抑制5-LO易位，并与LT生物合成相关。这些结果表明，camp介导的PMN中PKA活化导致5-LO易位和LT生物合成的同时抑制，并支持p38在相关信号通路中的作用。这代表了人类PMN中5-LO易位的第一个生理下调机制。
5-Lipoxygenase (5-LO) catalyzes the transformation of arachidonic acid to leukotrienes (LT). In stimulated human PMN, activation of 5-LO involves calcium, p38 MAP kinase (p38) phosphorylation, and translocation of 5-LO from the cytosol to nuclear membranes containing the 5-LO activating protein (FLAP). In this study, cAMP-elevating agents such as isoproterenol, prostaglandin E2, CGS-21680 (an adenosine A(2a) receptor agonist), the type IV phosphodiesterase inhibitor RO 201724, the adenylate cyclase activator forskolin, and the Gs-protein activator cholera toxin all inhibited LT biosynthesis and 5-LO translocation to the nucleus in cytokine-primed human PMN stimulated with platelet-activating factor and in human PMN stimulated with the endomembrane Ca2+-ATPase blocker thapsigargin. Furthermore, monophosphorothioate analogs of cAMP, which activate protein kinase A (PKA), also inhibited LT biosynthesis and 5-LO translocation in stimulated cells. Treatment of PMN with CGS-21680 also prevented the phosphorylation of p38 by thapsigargin. Treatment of PMN with the PKA inhibitors H-89 and KT-5720 prevented the inhibitory effect of cAMP-elevating agents on LT biosynthesis, 5-LO translocation, and p38 phosphorylation, whereas the p38 inhibitor SB 203,580 dose-dependently inhibited arachidonic acid-induced LT biosynthesis. The 5-LO translocation was also inhibitable by the FLAP antagonist MK-0591 and correlated with LT biosynthesis in all experimental conditions tested. These results indicate that cAMP-mediated PKA activation in PMN results in the concomitant inhibition of 5-LO translocation and LT biosynthesis and support a role of p38 in the signaling pathway involved. This represents the first physiological down-regulation mechanism of 5-LO translocation in human PMN.