Figure 5.

Effect of long-term and repetitive NIR light exposure on ROS production. (A) At day 0, HAECs were seeded and LPS-induced (h,i) or not induced (a–g) for activation of inflammation and subjected (c,f,i) or not subjected (a,b,d,e,g,h) to brief 10 min intervals of NIR light exposure, repeated once every 12 h, over a 48 h trial period according to the experimental procedure depicted in Figure 1A. At day 1 (a–c), day 2 (d–f) or day 3 (g–i) post seeding, that correspond respectively to 6 h, 6 h and 18 h after the last NIR light exposure, living HAECs were dye-labeled with DCFH-DA for 10 min and observed using an inverted Leica TCS SP5 confocal microscope. Control cell cultures not exposed to NIR light were treated in an identical manner. Scale bar is 10 μm. (B) Fluorescence intensities were measured cell-by-cell on z-projected images using ImageJ.