Figure 4.

Enlargement of classical to suFAs recruits α-SMA to stress fibers. REF-52 myofibroblasts were grown for 12 h on extendable PDMS membranes that have been provided with covalently bound FN islets. Cells were then subjected to a 135% linear stretch and stained after 6 h for α-SMA (A and D), vinculin (B and E), and FN (C and F). Despite enlarging 6- and 4-μm-long classical FA-sized islets by the same factor, only the resulting 8.1-μm-long suFA islets (B and C) induced formation of α-SMA–positive stress fibers (A), but not resulting 5.4-μm-long classical FA islets (D–F). The experiment was performed three times and representative results are shown. Bar, 25 μm.