IL-22 attenuates bleomycin-induced epithelial mesenchymal transition (EMT) and impaired cell viability of alveolar epithelial cells. (a) Reverse transcription-polymerase chain reaction (RT-PCR) analysis was performed for IL-22R1 and GADPH on total RNA isolated from the whole lungs of human and mice, as well as human cell lines A549 and HFL1. PCR products were analyzed in ethidium bromide-2% agarose gels. (b) Human alveolar epithelial cell line A549 was treated with 10 ng/mL IL-22 at the indicated length of time. Levels of phosphorylated STAT3, total STAT3, and GADPH were determined by western blotting and analyzed by densitometry compared to GADPH expression. Fold increase in pSTAT3 expression after normalization to total STAT3 expression is shown. The experiments were performed thrice with similar results. (c) and (d) After induction by bleomycin (BLM) (100 mU/mL), A549 was treated with or without IL-22 at the indicated concentrations for 48 h. Protein levels of α-smooth muscle actin (α-SMA) and GADPH were determined by western blotting in cell homogenates and analyzed by densitometry compared to GADPH expression (c). Cell viability was examined by cell counting kit-8 (CCK-8) analysis (d). Each condition included 6~8 wells. , . Results in (c) represent one out of three independently performed experiments with similar outcomes. Values in (b), (c), and (d) are shown as . ; .
