The dynamics of cell morphology, in particular membrane blebbing, was studied after induction of apoptosis by etoposide or camptothecin in four human stabilized cell lines (Hep2, HT-29 and HL-60). Time lapse videomicroscopy and F-actin staining various dynamic parameters of this process including its duration, maximal extent, stages and final endpoints in individual cells.
Although generally occurring in predictable patterns, our results indicatea relatively significant variability both in appearance and temporal organization of blebbing not only between different cell lines but also within them. Apoptosis was confirmed by detection of activated caspase-3 and nuclear fragmentation.
The results indicate that in fibroplasts hexavalent chromium-induced damage to cytoskeleton and mitochondria might occur concurrently at relatively early stages of exposure. Furthermore, alternations of these targets seem to activate mitochondria-dependent and -independent apoptosis.