Figure 4

In vitroproduction of SP-D by alveolar type II cells after IL-6 stimulation. (A) Primary rat alveolar type II cells were cultured in the presence or absence of DCI and IL-6 for up to 4 days and intra-cellular SP-D and SP-A levels were assayed by Western blot analysis. Day 0 SP-D and SP-A signals were obtained from freshly isolated alveolar type II cells. To maintain the SP-D producing phenotype, cells have to be cultured in the presence of DCI (10 nM dexamethason, 100 nM IBMX, 10 nM cAMP) that in turn stimulates SP-D production. IL-6 selectively stimulated the production of SP-D but did not induce up-regulation of SP-A. (B) Increase of SP-D after IL-6 stimulation at day 4 was slightly dose dependent. All levels were compared to non-stimulated alveolar type II cells cultured in DCI containing medium (DCI control).