Contribution of HMSE-1 to surfactant conversion under acute inflammatory conditions

A reduced content of biophysically active large surfactant aggregates is a common finding in acute inflammatory lung disease. Cyclic surface area changes and a carboxylesterase activity (surfactant convertase) are thought to mediate this subtype conversion. However, data concerning regulation of surfactant convertase are scarce. We therefore investigated the expression and activity of lung surfactant convertase and HMSE-1, a potential macrophage-derived human convertase, under normal and acute inflammatory conditions.