Figure 2.

Spermidine inhibits caspase 3 activity. (a) Cell death was measured by Annexin V-FITC/PI double staining followed with flow cytometric analysis. Representative data were presented. (b) The percentages of early apoptotic and late apoptotic/necrotic cells were calculated from three independent experiments. (c) Caspase 3 activity in PC12 cells was measured by kit, and normalized to control. Data were calculated from six independent experiments. (d) mRNA level of caspase 3 was measured by real-time qPCR. The caspase 3 mRNA level was normalized by that of GAPDH. Data were calculated from three independent experiments. (e) Immunostaining of cleaved caspase 3 with an anti-cleaved caspase 3 antibody (green). Nuclei were counterstained with Hoechst 33342. Scale bar, 20 μm. (f) Protein levels of pro-caspase 3 and cleaved caspase 3 were examined by western blotting. GAPDH was used as internal control. At least three independent experiments were conducted and representative immunoblots were presented. CasI, caspase inhibitor z-VAD-fmk. *P<0.05, **P<0.01 versus Ctrl; ^#P<0.05, ^##P<0.01 versus STS