Abstract
Using intact and fractionated human polymorphonuclear leukocytes (PMNL), we provide evidence that the enantioselective leukotriene synthesis inhibitor (LSI) BAY X 1005, (R)-2-[4-(quinolin-2-yl-methoxy)phenyl]-2-cyclopentyl acetic acid binds specifically to a high-affinity binding site, which is most likely identical to FLAP.
BAY X 1005 blocks the translocation of 5-lipoxygenase (5-LOX) in PMNL stimulated by the calcium ionophore A23187 or chemotactic stimuli such as PAF, C5a or fMLP as does MK-886. In contrast to the direct 5-LOX inhibitors (LOI) A-64077 and AA-861, the degree of leukotriene synthesis inhibition declines with increasing duration of A23187-induced leukocyte activation in the presence of BAY X 1005 and MK-886. Kinetic studies performed with BAY X 1005 showed that this effect was not accompanied by a significant translocation of 5-LOX from the cytosol to the microsomal fraction. Because FLAP has been implicated in the transfer of arachidonic acid to 5-LOX and A23187 is a potent activator of leukocyte phospholipase A2, we hypothesized that the observed loss of leukotriene synthesis inhibition may be due to competition of BAY X 1005 binding by endogenously released arachidonic acid. Accordingly, binding of BAY X 1005 to FLAP in intact and fractionated cells is dose-dependently inhibited by arachidonic acid and other unsaturated long-chain fatty acids, but not by saturated fatty acids. Therefore, we conclude that BAY X 1005 or MK-886 inhibit leukotriene biosynthesis by binding to FLAP, thereby preventing 5-LOX translocation and substrate transfer to the enzyme.
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J. A. Mancini, M. Abramovitz, M. E. Cox, E. Wong, S. Charleson, H. Perrier, Z. Wang, P. Prasit and P. J. Vickers,5-Lipoxygenase-activating protein is an arachidonate binding protein. FEBS Lett.318, 277–281 (1993).
A. Hatzelmann, R. Fruchtmann, K.-H. Mohrs, S. Raddatz and R. Müller-Peddinghaus,Mode of action of the new selective leukotriene synthesis inhibitor BAY X 1005, (R)-2-[4-(quinolin-2-yl-methoxy)phenyl]-2-cyclopentyl acetic acid, and structurally related compounds. Biochem. Pharmacol.45, 101–111 (1993).
R. Müller-Peddinghaus, C. Kohlsdorfer, P. Theisen-Popp, R. Fruchtmann, E. Perzborn, B. Beckermann, K. Bühner, H. J. Ahr and K.-H. Mohrs,BAY X 1005, a new inhibitor of leukotriene synthesis: In vivo inflammation pharmacology and pharmacokinetics. J. Pharmacol. Exp. Ther.267, 51–57 (1993).
S. Kargman, P. Prasit and J. EvansTranslocation of HL-60 cell 5-lipoxygenase. J. Biol. Chem.266, 23745–23752 (1991).
A. Wong, M. N. Cook, S. M. Hwang, H. M. Sarau, J. J. Foley and S. T. Crooke,Stimulation of leukotriene production and membrane translocation of 5-lipoxygenase by cross-linking of the IgE receptors in RBL-2H3 cells. Biochemistry31, 4046–4053 (1992).
A. Hatzelmann, R. Fruchtmann, K.-H. Mohrs, S. Raddatz, M. Matzke, U. Pleiss, J. Goosens, J. Keldenich and R. Müller-Peddinghaus,Mode of action of the leukotriene synthesis inhibitor BAY X 1005, and other structurally related quinoline derivatives—biological implications. In: Adv. Prostaglandins Leukotr. Research; Raven Press, New York (in press).
R. Fruchtmann, K.-H. Mohrs, A. Hatzelmann, S. Raddatz, B. Fugmann, B. Junge, H. Horstmann and R. Müller-Peddinghaus,In vitro pharmacology of BAY X 1005, a new inhibitor of leukotriene synthesis. Agents and Actions38, 188–195 (1993).
J. D. Winkler, C.-M. Sung, W. C. Hubbard and F. H. Chilton,Influence of arachidonic acid on indices of phospholipase A 2 activity in the human neutrophil. Biochem. J.291, 825–831 (1993).
S. Hammarström, M. Hamberg, B. Samuelsson, E. Duell, M. Stawiski and J. J. Voorhees,Increased concentration of non-esterified arachidonic acid, 12L-hydroxy-5,8,10,14-eicosatetraenoic acid, prostaglandin E, and prostaglandin F 2 alpha in epidermis of psoriasis. Proc. Natl. Acad. Sci. USA72, 5130–5134 (1975).
M. Abramovitz, E. Wong, M. E. Cox, C. D. Richardson and P. J. Vickers,5-Lipoxygenase-activating protein stimulates the utilization of arachidonic acid by 5-lipoxygenase. Eur. J. Biochem.215, 105–111 (1993).
M. Coffey, M. Peters-Golden, J. C. Fantone III and P. H. S. Sporn,Membrane association of active 5-lipoxygenase in resting cells—Evidence for novel regulation of the enzyme in the rat alveolar macrophage. J. Biol. Chem.267, 570–576 (1992).
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Kast, R., Fruchtmann, R., Kupferschmidt, R. et al. Role of 5-lipoxygenase-activating protein in the regulation of 5-lipoxygenase activity in human neutrophils. Agents and Actions 41 (Suppl 2), C166–C168 (1994). https://doi.org/10.1007/BF01987624
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DOI: https://doi.org/10.1007/BF01987624