Plasminogen-stimulated inflammatory cytokine production by airway smooth muscle cells is regulated by annexin A2

Abstract

Plasminogen has a role in airway inflammation. Airway smooth muscle(ASM) cells cleave plasminogen into plasmin, a protease with proinflammatory activity. In this study, the effect of plasminogen on cytokine production by human ASM cells was investigated in vitro. Levels of IL-6 and IL-8 in the medium of ASM cells were increased byincubation with plasminogen (5-50 μg/ml) for 24 hours (P,0.05; n = 6-9), corresponding to changes in the levels of cytokine mRNA at 4 hours. The effects of plasminogen were attenuated by a2- antiplasmin (1 mg/ml), a plasmin inhibitor (P < 0.05; n = 6-12). Exogenous plasmin (5-15 mU/ml) also stimulated cytokine production (P < 0.05; n = 6-8) in a manner sensitive to ..