LOX/L gene expression level changes induced by various pro-fibrotic stimuli in primary human lung cells. (a) Primary human lung fibroblasts (NHLF) were treated with TGF-β1 (5 ng/ml), FGF (20 ng/ml) or PDGF (50 ng/ml) for 24 hours or kept under hypoxic conditions (0.5% O2) for 24 h followed by RNA isolation and quantitative PCR for the members of the LOX/L family. Data was normalized to RNA polymerase 2 expression and depicted as fold change relative to respective control treatment. Data is shown as mean ± SD of 3–4 independent experiments. (b) Primary human bronchial epithelial cells (HBECs) were differentiated at the air liquid interface for 21 days followed by basal treatment with TGF-β1 (5 ng/ml) for 48 h or kept under hypoxic conditions for 24 hours. RNA was isolated and quantitative PCR for the members of the LOX/L family was performed. Expression data was normalized to RNA polymerase 2 expression and control treatment and is depicted as mean ± SD of three experiments. *p < 0.05; **p < 0.01; ***p < 0.001, relative to control treatment.