Figure 3.

Effect of collagen aging on DDR1 expression and activation. A. MCF-7 cells, B. ZR-75-1 cells. Cells were starved during 12 hours, and then cultured 6 hours in adult and old 3D collagen matrices. Immunoprecipitation was performed using anti-DDR1 antibody, then a western blot was realized with a phosphotyrosine antibody to detect DDR1 activation. The membrane was then stripped, and total DDR1 was visualized using a specific DDR1 antibody (upper panel). Blots are representative of three independent experiments (for MCF-7) and two independent experiments (for ZR-75-1). The histogram shows the ratio of phosphotyrosine relative to total DDR1 (lower panel). Values represent the mean ± S.D. (*p < 0.05, **p < 0.01).