Fig. 6

mTOR promotes SREBP1 nuclear localization, SCD1 expression, and fibroblast activation downstream of TGF-β1. HFL1 cells were treated with TGF‑β1 (10 ng/ml) and Torin1 (5 nM) for 24 h. A–D A western blot analysis of SREBP1, FASN and SCD1 in HFL1 cells was performed. E The protein levels of SREBP1 in cytosol, nuclear and membrane extracts were detected by western blotting. F The intracellular localization of SREBP1 was visualized by immunofluorescence. Scale bar, 10 μm. G–J The protein levels of fibronectin, COL1A1, and α-SMA were measured by western blotting. K–N The immunofluorescence staining of HFL1 cells with antibodies against fibronectin, collagen I, and α-SMA was captured by confocal microscopy. Scale bar, 10 μm. The fluorescence intensities were quantified (n = 5 images from each group were used for quantification). The data are representative of three independent experiments and are presented as the means ± SEMs. *P < 0.05, **P < 0.01, ***P < 0.001, and ****P < 0.0001, as determined by one-way ANOVA with the Tukey‒Kramer post hoc test