FIG 4.

The IFN-γ-induced disruption of the actin cytoskeleton mimics the effect of cytochalasin D. (A) HeLa cells were left untreated, treated with IFN-γ (100 U/ml, 24 h), or treated with different actin polymerization inhibitors (cytochalasin D and latrunculin B) (both at 0.2 μM, 30 min). Subsequently, the actin cytoskeleton was stained using fluorescently labeled phalloidin. Arrowheads, disrupted actin cytoskeleton, which was visualized as small, granular structures in the cytoplasm; arrows, bleb-like aggregates at the cell membrane in the latrunculin B-treated cells. The nuclei were counterstained with DAPI. (B) HUVECs were treated as described in the legend to panel A, with the exception that the polymerization inhibitor was utilized at a concentration of 0.1 μM. The actin pattern was observed as described in the legend to panel A and is indicated in the same manner described in the legend to panel A. The nuclei were counterstained with DAPI. Bars = 25 μm.