Figure 4.

MMP1 knockdown increases collagen I levels in GOFs. (a) GOFs were treated with control or MMP1 specific siRNA for 48 hours and then treated with either vehicle (DMSO) or the AHR ligand FICZ (1 µM) for 1 hour before addition of TGFβ (5 ng/mL) as indicated. (upper panel) After 72 hours of TGFβ treatment, cell extracts were isolated and analyzed by Western blot for MMP1, Collagen 1 (COL1A1) and β-tubulin (loading control). Relative protein expression (R.E.) based on densitometry are listed below the images. MMP1 siRNA reduced MMP1 protein expression and increased COL1A1 compared to control siRNA levels. (b) shows an additional strain with increased COL1A1 expression in the presence of MMP1 siRNA. Full length blots for (a,b) can be found in Supplemental Fig. 16. An additional strain was used for this experiment in Supplemental Fig. 4 with its corresponding full-length blots in Supplemental Fig. 24.