FIGURE 7:

VEGF induces Cx43 GJ internalization via CME. (A) PAECs were (a) untreated or treated with VEGF for 15 min at 37°C in HEPES-buffered, serum-free DMEM without (b) or with (c) 0.45 M sucrose (hypertonic medium, a potent inhibitor of endocytosis) or with inhibitors of CME (d) 80 μM dynasore, (e) 30 μM Pitstop 2, or (f) 4 μM ikarugamycin before fixation and immunostaining cells for Cx43. Representative images acquired with identical camera settings are shown. (B) Quantitative analyses of plasma membrane–localized Cx43 GJ fluorescence of seven independent measurements. Note significant inhibition of Cx43 GJ internalization in cells in which CME was blocked. (C) Coimmunolocalization of Cx43 (green) and clathrin (red) in PAECs treated for 15 min with VEGF. Several colocalizing cytoplasmic vesicles (yellow) are depicted with arrows.