Figure 4.

Alcohol ingestion, or direct treatment with TGFβ1, increased the expression of the αvβ6 integrin in alveolar epithelial cells, and antibodies to αvβ6 reversed epithelial monolayer permeability in alcohol treated co-cultures of epithelial cells and macrophages. Shown are (A) the relative gene expression, (B) flow cytometric analysis of membrane protein expression of the integrin chains αv and β6 in freshly isolated alveolar epithelial cells from control- and alcohol-fed rats, (C) the relative gene expression of αv and β6 in alveolar epithelial cells isolated from control-fed rats and treated in vitro with 10 ng/ml of active TGFβ1 for 48 h. n = 4; * p < 0.05 compared to control-fed in panel A & B and compared to untreated (no TGFβ1) group in panel C. In panel (D) primary alveolar type II epithelial cells and macrophages from four rats were cultured with or without 60 mM alcohol, anti-αvβ6 Abs (1 μg/ml) for 6 days. The barrier function of epithelial monolayer was measured by transepithelial resistance (TER) and data are shown as mean ± SEM. * p < 0.05 compared to co-culture without alcohol (second column). ** p < 0.05 compared to co-culture with alcohol but without antibodies to αvβ6 (third column). Transepithelial resistance for alcohol treated co-cultures with anti-TGFβ1 antibody and IgG in this experiment was 637 ± 29 and 465 ± 57, respectively (not shown in the graph).