Fig. 9. Increased apoptosis and reorganized fibronectin-rich extracellular matrix in 3T3-L1 cells overexpressing ADAM12 at the cell surface. ADAM12-cyt-expressing cells and control cells were treated with cycloheximide and TNF- to induce apoptosis, and stained with DAPI, and the number of apoptotic cells was counted (A-C). ADAM12-cyt-expressing cells were more prone to apoptosis (A) than were control cells (B). Apoptotic cells (fragmented nuclei) are indicated by arrows. In C, the effect of ß1-activating antibody 9EG7 on TNF--induced apoptosis was examined. Apoptosis in ADAM12-cyt expressing cells (black columns) could be prevented by 9EG7 (*P<0.01), whereas the antibody had no effect on control cells (hatched columns). Fibronectin matrix assembly was altered in ADAM12-cyt-expressing cells (D) compared with control cells (E). Bars, 5 µm (A,B) and 12 µm (D,E).