Figure 8

Pharmacological inhibition of CTSB activity prevented caspase-3 activation and apoptosis in Pb-exposed cells. Cells were pre-incubated with 2 μM CA 074 for 1 h, then exposed to 0.5 μM Pb for another 12 h to analyze the following assays. (a) Protein level of cleaved caspase-3 was assessed by western blot. Upper panel: representative western blot image; lower panel: quantitative analysis (mean±S.E.M., n=4). (b and c) Apoptosis was analyzed by flow cytometry. Representative flow cytometry analysis of Annexin V-PI staining is shown in (b) and its quantitative results (c) are expressed as mean±S.E.M. (n=9). (d and e) Apoptotic morphological changes were assessed by DAPI staining. Representative morphological changes of apoptosis are present in (d), and its statistical result of apoptotic rates (e) are expressed as mean±S.E.M. (n=9). **P<0.01