蛋白酶激活受体1介导人肺上皮细胞分泌MCP-1

目的探讨蛋白酶激活受体1(protease-activated receptors1,PAR1)激动肽和凝血酶对人肺上皮细胞单核细胞趋化蛋白-1(monocyte chemoattractant protein-1,MCP-1)分泌的影响.方法人肺上皮细胞系A549细胞分别接种于12孔培养板各孔内,并分别用不同浓度的PAR1激动肽SFLLR和反PAR1激动肽RLLFS以及不同浓度的凝血酶和/或凝血酶抑制剂水蛭素进行刺激,刺激时间为2、16 h.用ELISA方法检测上清液中的MCP-1水平.结果经过16 h的培养,PAR1激动剂SFLLR可引起浓度相关性MCP-1的释放增加,增加到300μmol/L时诱导MCP-1的释放量比基础分泌量增加了近12倍,反PAR1激动剂RLLFS不能引起MCP-1的释放增加.凝血酶也可引起浓度相关性MCP-1释放,凝血酶在浓度3 000 U/L时就可引起MCP-1释放量增加,10 000 U/L时诱导MCP-1的释放量达高峰,为基础分泌量的5倍.凝血酶抑制剂水蛭素可以抑制凝血酶对MCP-1的释放作用.时间相关曲线表明,从2 h起即可引起PAR1介导的MCP-1释放增加,16 h达高峰.结论PAR1激动肽和凝血酶可促进人肺上皮细胞分泌MCP-1,PAR1拮抗剂和凝血酶抑制剂可能具有抗炎作用.

Protease-activated receptor 1 challenges human lung epithelial cells to produce MCP-1

Objective To investigate the actions of PAR1 agonists and thrombin on the secretion of monocyte chemoattractant protein (MCP)-1 from human lung epithelial cells. Methods A549 cells were cultured in a 12-well culture plate. The challenge was performed by addition of various concentrations of PAR1 agonist peptides SFLLR and its reverse peptides RLLFS, thrombin or thrombin inhibitor named hirudin into each well, respectively. After 2 h or 16 h, the reactions were terminated by removal of the supernatant from each well. A sandwich ELISA was used to determine the levels of MCP-1 in supernatants. Results Following 16 h incubation, SFLLR could induce concentration-dependent secretion of MCP-1. The maximum release of MCP-1 was nearly 12-fold more than baseline release. The reverse PAR1 agonists had little effects on MCP-1 release. Thrombin could induce concentration-dependent secretion of MCP-1. As low as 3 000 U/L thrombin could induce MCP-1 release from epithelial cells, and the maximum of accumulated release of MCP-1 was observed with 10 000 U/L thrombin, which was 5-fold more than baseline release. Thrombin inhibitor hirudin could inhibit thrombin induced secretion of MCP-1. The time course showed that the actions of PAR1 agonist peptides SFLLR and thrombin initiated at 2 h and reached their peak at 16 h. Conclusion PAR1 agonist peptides and thrombin are potent secretogogue of MCP-1 release from cultured human lung epithelial cells, and PAR1 antagonists and thrombin inhibitor may possess the ability to inhibit airway inflammation.