Fig. 2. Effect of extracellular-signal-regulated kinase 5 (ERK5) inhibitor, BIX02189, on collagen gel contraction and chemotaxis. (A, B) Effect of BIX02189 on HFL1-mediated gel contraction (A) and chemotaxis (B). Various concentrations of BIX02189 with or without transforming growth factor (TGF)-β1 were assessed in the HLF1-mediated gel contraction and chemotaxis assays. The vertical axis in (A) shows the gel size on day 3, expressed as a percentage of the control. The vertical axis in (B) shows the number of migrated cells per five high-power fields (5HPF). (C, D) BIX02189 suppression of collagen gel contraction (C) and chemotaxis (D) in lung fibroblasts isolated from control and interstitial pneumonia (IP) subjects. The vertical axis in (C) shows the size of contracted gels following BIX02189 treatment for 72 h, expressed as a percentage of the control. The vertical axis in (D) shows the number of migrated cells per five high-power fields (5HPF) following BIX02189 treatment for 8 h, expressed as a percentage of the control. (E, F) Correlation between the magnitude of the TGF-β1-induced increase in gel contraction and chemotaxis and degrees of suppression of TGF-β1-mediated gel contraction and chemotaxis by BIX02189. Controls are represented by circles; closed triangles and squares indicate lung fibrosis subjects with histological nonspecific interstitial pneumonia and usual interstitial pneumonia patterns, respectively. Each symbol represents one patient. (G, H) Analysis of the IP group according to the histological pattern. The values represent the mean ± SEM of at least three independent experiments. (A, B) ^†P<0.05, ^††P<0.001, vs. solvent control; *P<0.05, **P<0.001 vs. stimulus. (C, D, G, H) *P<0.05, ^†P<0.01, ^‡P<0.005, ^§P<0.001.