Fig. 3

Inhibition of colchicine-triggered apoptosis by caspase inhibitors. (A) CGC were treated with colchicine (1 µM) in the presence or absence of different caspase inhibitors (YVAD-cmk, filled circles; DEVD-fmk, open circles; zD-cbk, filled squares; zVAD-fmk, open squares), and the percentage of apoptotic neurons was counted after 16 hr. Data are means ± SEM from triplicate determinations. Essentially similar data were obtained with nocodazol as stimulus. (B) CGC were treated as above in the presence of different caspase inhibitors. At the end of the incubation cell lysates were prepared and analyzed by Western blot for cleavage of fodrin. (C) CGC were incubated for 24 hr with colchicine (1 µM) in the presence of zVAD-fmk (100 µM). Tubulin structure and nuclear morphology were imaged by confocal microscopy. The width of one image corresponds to 100 µm. (D) CGC were incubated for 48 hr with colchicine (1 µM) in the presence or absence of zVAD-fmk (100 µM). Nuclei were stained with H-33342 and imaged by confocal microscopy. Cells that were treated with zVAD-fmk displayed marginated, but not condensed, chromatin (indicated by the arrow; for comparison apoptotic nuclei of cells that did not receive the caspase inhibitor are also shown). Note the scale difference (the image width corresponds to 25 µm).