Cyclosporin H

Cyclosporin H是一种有效的\选择性的以及竞争性的甲酰肽受体(FPR)拮抗剂,其IC50值为0.7 μM[1].

甲酰肽受体(FPR)属于G蛋白偶联受体,参与趋化作用并介导免疫细胞响应感染.

Cyclosporin H(CsH)是一种强效的FPR选择性拮抗剂.在人中性粒细胞中,Cyclosporin H抑制FMLP诱导的超氧阴离子(O2-)形成.CsH抑制FMLP(3 nM)与HL-60细胞膜结合,其IC50值与Ki值分别为0.7 μM和0.10 μM.CsH抑制FMLP(100 nM)诱导的GTP水解,其IC50值与Ki值分别为1.3 μM和0.79 μM.CSH还能抑制FMLP诱导的胞内Ca2+浓度\O2-形成以及β-葡糖醛酸酶释放的增加,其IC50值分别为0.23 μM\0.6 μM和2.2 μM,其Ki值分别为0.08 μM\0.24 μM和0.45 μM[1][2].在外周血嗜碱性粒细胞中,CsH(8 ~ 800 nM)呈浓度依赖性地竞争抑制FMLP诱导的白三烯C4以及组胺释放[3].使小鼠吸入过敏原,从小鼠支气管肺泡灌洗液中分离出嗜酸性粒细胞,Cyclosporin H与10 U/ml白细胞介素5联合用药呈浓度依赖性地促进细胞凋亡.Cyclosporin H与10 U/ml GM-CSF合用也能增加细胞凋亡,但其作用较弱[4].

参考文献：
[1].  Wenzel-Seifert K, Seifert R. Cyclosporin H is a potent and selective formyl peptide receptor antagonist. Comparison with N-t-butoxycarbonyl-L-phenylalanyl-L-leucyl-L-phenylalanyl-L- leucyl-L-phenylalanine and cyclosporins A, B, C, D, and E. J Immunol, 1993, 150(10): 4591-4599.
[2].  Wenzel-Seifert K, Grünbaum L, Seifert R. Differential inhibition of human neutrophil activation by cyclosporins A, D, and H. Cyclosporin H is a potent and effective inhibitor of formyl peptide-induced superoxide formation. J Immunol, 1991, 147(6): 1940-1946.
[3].  de Paulis A, Ciccarelli A, de Crescenzo G, et al. Cyclosporin H is a potent and selective competitive antagonist of human basophil activation by N-formyl-methionyl-leucyl-phenylalanine. J Allergy Clin Immunol, 1996, 98(1): 152-164.
[4].  Kitagaki K, Nagai H, Hayashi S, et al. Facilitation of apoptosis by cyclosporins A and H, but not FK506 in mouse bronchial eosinophils. Eur J Pharmacol, 1997, 337(2-3): 283-289.