Fig. 4.

TGF-β1 treatment promotes ATII transdifferentiation mainly by promoting loss of ATII phenotype. ATII cells were cultured in the absence or presence of human (h) TGF-β1 (4 ng/ml) through 7 days. A: the mRNA expression of Sftpa, Sftpb, and Sftpc at day 3 was determined by qRT-PCR and graphed relative to values obtained from cells treated with vehicle; n = 3; *P < 0.05. B: the mRNA expression of T1α and Aqp5 at day 5 was determined by qRT-PCR and graphed relative to values obtained from cells treated with vehicle; n = 3; *P < 0.05. C: cell lysates were harvested at the stated times and immunoblotted for proSFTPC and T1α, with β-actin used as a loading control. Blots are representative of 4 experiments with similar results.