Figure 1.

IL-8 induces idiopathic pulmonary fibrosis (IPF) mesenchymal progenitor cell (MPC) DNA damage. A: histone H2AX (γH2AX), p21, and phosphorylated (p) and total replication protein subunit 2 (RPA2) levels were quantified in IPF and control MPCs by Western blot analysis (left) (n = 6 IPF and control MPC cell lines each). GAPDH served as loading control. Densitometry values summarizing Western blot data are shown at right. B–D: IPF and control MPCs were treated with recombinant IL-8 (5 ng) or vehicle control (n = 6 IPF and control MPC cell lines each). B: a representative Western blot quantifying γH2AX levels in 1 IPF and 1 control MPC cell line (left). GAPDH served as loading control. Densitometry values summarizing Western blot data are shown at right. C: p21 levels were quantified by quantitative PCR (Q-PCR; left) and Western blot analysis (shown is a representative Western blot; center). Densitometry values summarizing Western blot data are shown at right. D: phosphorylated and total RPA2 levels were quantified by Western blot analysis (shown is a respresentative Western blot, left). Densitometry values summarizing the Western blot data are shown at right. E: IPF MPCs were treated with 5 ng of recombinant IL-8 in the presence of the IL-8 receptor inhibitor reparixin (IL-8 + R) or vehicle control (IL-8 + DMSO) (n = 6 IPF MPC cell lines). Cells not treated with IL-8 served as an additional control (Untreated). Shown is a representative Western blot quantifying γH2AX levels in 1 IPF MPC cell line (left). GAPDH served as loading control. Densitometry values summarizing the Western blot data are shown at right.