Research Paper Volume 18 pp 67—81

Characterization and responses to TGF-β1 in IMR90 human diploid lung fibroblasts. (A) p16 expression levels of IMR90 lung fibroblasts at the indicated population doubling levels (PDL). β-tubulin was used as loading control. Numeric values indicate the densitometric ratio of p16 to its corresponding β-tubulin. (B) p16 mRNA levels in LPDL or HPDL fibroblasts at baseline, measured by real-time RT-PCR and normalized to β-actin. (C, D). α-SMA (C) and Col3A1 (D) mRNA levels in LPDL and HPDL cells treated with or without TGF-β1 (2ng/ml) for 24 hours. Data are normalized to β-actin and represent the average of at least three independent experiments. Bar graphs indicate mean ± standard errors (SE). * p<0.05, compared with the control in the same group.