Integrins mediate binding of myofibroblasts to LTBP-1. (A and B) Arrays of an islet with typical focal adhesion features (10 × 4 × 1.5 µm) were microcontact printed using purified LTBP-1–EGFP (A) or plasma FN as a control (B). After attachment for 4 h to microcontact printed arrays in the absence of serum, hDMfs were immunostained for the printed protein (red, false colored for LTBP-1–EGFP), vinculin, and integrin subunits β1, β3, and β5 (green). Insets show higher magnification views of select focal adhesion. (C) hDMfs were seeded onto LTBP-1–EGFP-coated substrates in the presence of blocking antibodies or cyclic peptides against integrin subunits β1, β3, and β5 or the RGD site. Focal adhesion formation was visualized with vinculin (green), and nuclei were stained with DAPI (blue). (D) The number of adherent hDMfs on LTBP-1–EGFP-coated substrates was quantified by image analysis. Graph shows mean values and SDs from at least three independent experiments (***, P ≤ 0.005; two-tailed paired t test). con, control. Bars: (main images) 20 µm; (insets) 5 µm.