Fluorescence micrographs showing the effects of HALI and di-h-HALI on actin organization in LSECs, monitored with rhodamine-phalloidin (F-actin / red) and fluorescein-DNase I staining (G-actin / green). Blue color represents the nucleus stained with DAPI. (A) F-actin distribution in control LSECs shows the presence of cytoplasmic stress fibers and peripheral bands of actin bundles that line the cell margin. Note that G-actin is mainly localized in the perinuclear region. (B) LSECs treated with 100 nM HALI for 10 minutes, show a loss of cytoplasmic F-actin bundles and peripheral F-actin bands are less dense, whereas the cytoplasm is faintly stained and only few small F-actin dots and short fine filaments remaining. G-actin fluorescence increased markedly as compared to control LSECs and is distributed thorough the cytoplasm. (C) LSECs treated with 100 nM of di-h-HALI for 10 minutes show loss of F-actin bundles and appearance of brightly stained F-actin patches. Peripheral F-actin bands are still present, and furthermore G-actin is diffuse and faintly stained as compared to HALI-treated LSECs. Scale bars, 5 μm.