Fig. 4

Effect of CCh-mediated endogenous TGF-β1 release in lung fibroblasts. Sub-confluent HFL1 cells (a) and primary lung fibroblasts (b) were cultured in SF-DMEM for 24 h in the presence or absence of CCh with or without GLY and/or IND. After 24 h of incubation, supernatants were harvested and used for TGF-β1 quantification. Vertical axis: TGF-β1 production expressed as amount per cells. Horizontal axis: conditions. Each pair of symbols connected by a line represents data of an individual cell strain isolated from non-smokers or patients with COPD. Cells from non-smokers are indicated by open circles, cells from patients with COPD (GOLD I) by squares, and cells from patients with COPD (GOLD II) by closed circles. c Sub-confluent HFL1 cells were cultured in SF-DMEM for 24 h. Cells were casted into collagen gels in the presence of CCh with or without SB431542, a selective inhibitor of the TGF-β1 receptor, ALK5. Gel size was measured on day 3. Vertical axis: gel size expressed as a percentage of control. Horizontal axis: conditions. All values represent the mean ± SEM of three separate experiments, each performed in triplicate. d HFL1 cells were grown to sub-confluence in monolayer culture and serum deprived for 24 h. Cells were stimulated with CCh in the presence or absence of SB431542. After 48 h of incubation, cells were harvested for the detection of α-SMA by immunoblotting. Vertical axis, relative intensity of α-SMA/β-actin ratio; Horizontal axis, conditions. All values represent the mean ± SEM of the three different strains. ^† P < 0.05, compared with solvent control. *P < 0.05, compared with stimulus. ^§ P < 0.05, compared with non-smokers and COPD lung fibroblasts in the same stimulus group