Tandem Benzophenone Amino Pyridines, Potent and Selective Inhibitors of Human Leukotriene C<sub>4</sub> Synthase
作者:Thea K. Kleinschmidt、Martin Haraldsson、Devaraj Basavarajappa、Erik Lundeberg、Madhuranayaki Thulasingam、Maria Ekoff、Alexander Fauland、Christoph Lehmann、Astrid S. Kahnt、Lennart Lindbom、Jesper Z. Haeggström
DOI:10.1124/jpet.115.227157
日期:2015.10
Cysteinyl leukotrienes (cys-LTs) are lipid mediators of inflammation. The enzyme catalyzing synthesis of cys-LTs, leukotriene C4 synthase (LTC4S), is considered an important drug target. Here we report the synthesis and characterization of three tandem benzophenone amino pyridines as inhibitors of LTC4S in vitro and in vivo. The inhibitors were characterized in vitro using recombinant human LTC4S, MonoMac 6 cells, and a panel of peripheral human immune cells. In vivo, the compounds were tested in the Zymosan A-induced peritonitis mouse model. The molecules, denoted TK04, TK04a, and TK05, were potent and selective inhibitors of LTC4S with IC50 values of 116, 124, and 95 nM, respectively. Molecular docking revealed binding in a hydrophobic crevice between two enzyme monomers and interaction with two catalytic residues, Arg104 and Arg31. The TK compounds potently inhibited cys-LT biosynthesis in immune cells. In coincubations of platelets and polymorphonuclear leukocytes, inhibition of LTC4S led to shunting of LTA4 toward anti-inflammatory lipoxin A4, which was significantly enhanced by simultaneous inhibition of LTA4H. Finally, we found that TK05 (6 mg⋅kg−1⋅body weight) reduces LTE4 levels in peritoneal lavage fluid by 88% and significantly decreases vascular permeability in vivo. Our findings indicate that the TK compounds are valuable experimental tools in eicosanoid research in vitro and in vivo. Their chemical structures may serve as leads for further inhibitor design. Novel drugs depleting cys-LT production could be beneficial for treatment of inflammatory diseases associated with overexpression of LTC4S.
胱氨酰白三烯(cys-LTs)是炎症的脂质介质。催化 cys-LTs 合成的酶--白三烯 C4 合成酶(LTC4S)被认为是一个重要的药物靶点。在此,我们报告了作为 LTC4S 体外和体内抑制剂的三种串联二苯甲酮氨基吡啶的合成和表征。我们使用重组人 LTC4S、MonoMac 6 细胞和一组外周人类免疫细胞对这些抑制剂进行了体外表征。在体内,这些化合物在 Zymosan A 诱导的腹膜炎小鼠模型中进行了测试。这些分子被命名为 TK04、TK04a 和 TK05,它们是 LTC4S 的强效选择性抑制剂,IC50 值分别为 116、124 和 95 nM。分子对接显示,它们结合在两个酶单体之间的疏水缝隙中,并与 Arg104 和 Arg31 这两个催化残基相互作用。TK 化合物能有效抑制免疫细胞中 cys-LT 的生物合成。在血小板和多形核白细胞的共同作用下,抑制 LTC4S 会导致 LTA4 向抗炎性脂质毒素 A4 转移,而同时抑制 LTA4H 会显著增强这种转移。最后,我们发现 TK05(6 mg⋅kg-1⋅ 体重)可将腹腔灌洗液中的 LTE4 水平降低 88%,并显著降低体内血管的通透性。我们的研究结果表明,TK 化合物是体外和体内类二十酸研究的重要实验工具。它们的化学结构可作为进一步设计抑制剂的线索。消耗 cys-LT 生成的新型药物可能有益于治疗与 LTC4S 过度表达相关的炎症性疾病。