Figure 4.

Caspase inhibitors partially blocked tau cleavage induced by pre-aggregated Aβ. A, Western blot analysis of active caspase-3 and 17 kDa tau fragment content in whole-cell extracts prepared from 21-d-in-culture hippocampal neurons treated with either DEVD (50 μm; specific caspase-3 inhibitor) or VAD (50 μm; general caspase inhibitor) 1 h before the treatment with pre-aggregated Aβ (20 μm) for 4 and 8 h using specific antibodies. B, C, Graphs showing changes in active caspase-3 and 17 kDa tau fragment content in samples obtained as described above. Data were obtained using Molecular Analyst software and normalized using total caspase-3 and tubulin as internal controls. Values are expressed as a percentage of untreated controls, considering the values obtained in these neurons as 100%. Each number represents the mean ± SEM from three different experiments. ^*p < 0.05, ^**p < 0.01, different from control.