Fig. 1.

Fluorescence confocal microscopic analysis of the actin cytoskeleton in the cultured human ARPE-19 cells. The cells were subjected to mechanical stretch (20%, 0.33 Hz) for 0, 6, or 24 h with or without pre-treatment with 2 μM Cytochalasin D. The structure of the actin cytoskeleton was examined with phalloidin-Rhodamine staining. The cells in the control groups displayed abundant and uniform phalloidin staining (a-c). After exposure to mechanical stretch for 24 h, the phalloidin-stained actin cytoskeleton appeared unclear and irregular with a statistically significant decrease in the average fluorescence intensity of F-actin fibres (d-f, m). In all the Cytochalasin D-treated cells, the disruption of the cytoskeletal structure and a decrease in the average fluorescence intensity were observed regardless of mechanical stress (g-l, m). *P<0.05 versus baseline, n = 3 experiments