Figure 1.

(a) DDR1 was activated by type I and type VIII collagen. HEK 293 cells were transfected with vector alone or DDR1 cDNA. The cells were incubated with plain media (C), 10 μg/ml type I collagen (I), or 10 μg/ml type VIII collagen (VIII) for 90 minutes, then cell lysates were collected and subjected to Western blotting. The same blots were sequentially probed with anti-phosphotyrosine (anti-P-Tyr) Ab (upper) and with DDR1 Ab (lower). (b) DDR1 mRNA expression was increased after injury of the rat carotid artery. Northern blot with RNA extracted from control carotids (C) and from carotids at various days after injury, then probed with a cDNA against mouse DDR1. Lower photograph is the methylene-blue–stained Northern blot showing 28s and 18s ribosomal RNA bands demonstrating equal loading in the lanes. (c) A Western blot, with arterial protein extracts from control carotids (C) and carotids taken at various times after injury, was probed with anti-human DDR1 Ab.