Fig. 4
From: The collagen structure of C1q induces wound healing by engaging discoidin domain receptor 2
C1q induces MMP2 and MMP9 expression via p38 and ERK phosphorylation. A–C Effects of C1q on MMP2 and MMP9 production in HT1080 cells were detected via a gelatin zymography assay. The relative amounts of MMP2 (B) and MMP9 (C) were quantified using Image J. Collagen-I was used as a positive control. SE: short exposure, LE: long exposure. D–F HT1080 cells were treated with or without 20 μg/mL collagen-I and C1q for the various time points indicated. The expression of p-p38, p38, p-ERK1/2, ERK1/2, and ß-actin were detected using western blotting. DDR2 phosphorylation was tested after the immunoprecipitation of DDR2. The fold induction compared to untreated samples (NT, 0 h) was quantified using Image J. Data are presented as the means ± SEM of three independent experiments. * p < 0.05, ** p < 0.01, *** p < 0.001 (one-way ANOVA)