Figure 4
Secreted protein acidic and rich in cysteine (SPARC) knockdown attenuates H 2 O 2 release from HFL-1 following transforming growth factor (TGF)-β stimulation. (A) HFL-1 cells pretreated with or without TGF-β (2 ng/ml) for 16 h were cocultured with A549 cells for 48 h in the absence or presence of NAC. A549 cell viability was assessed following 48 h of coculture by Cell Counting Kit-8. Data are expressed as means ± SE of three independent experiments. *P <0.05, **P <0.01 versus NAC 0 mM. (B) HFL-1 cells transfected with non-targeting control or SPARC siRNA were treated with or without TGF-β (2 ng/ml) for 16 h before H2O2 measurements. Data are expressed as means ± SE. Three replicate experiments showed similar results. **P <0.01 versus TGF-β-stimulated HFL-1 transfected with non-targeting control siRNA. (C) HFL-1 cells transfected with non-targeting control or SPARC siRNA were pretreated with or without TGF-β (2 ng/ml) for 16 h, and then washed before introduction of A549 cells. HFL-1 cell viability was assessed following 48 h of coculture by Cell Counting kit-8. Data are expressed as means ± SE of three independent experiments. **P <0.01 versus TGF-β-stimulated HFL-1 transfected with non-targeting control siRNA. (D) HFL-1 cells pretreated with or without TGF-β (2 ng/ml) for 16 h in the absence or presence of diphenyliodonium (DPI) before H2O2 measurements. Data are expressed as means ± SE. Three replicate experiments showed similar results. **P < 0.01 versus TGF-β-stimulated HFL-1 in the absence of DPI.