Activation of Cyclin-Dependent Kinase 5 Is a Consequence of Cell Death
Figure 3
Inhibiting production of p25 does not alter the mode of cell death induced by CPT. (a) Western blot of equal amounts of protein samples from C8 cells treated with CPT or CPT PD. (A) Cells exposed for 8 hours or 18 hours showed the activation of caspase-3 (17 kDa) by CPT both in the presence and in the absence of PD. (B): The expression of LC3-II, a 16 kDa fragment indicating autophagy, did not change during the course of death in either control or experimental situations. (C) expression of -tubulin demonstrated equivalent loading of protein samples. In summary, CPT marginally increases the activation of caspase 3 with or without PD but does not affect the appearance of LC3-II. (b) C8 cells treated with CPT or CPT PD for 8 or 18 hours were fixed for electron microscopy. Untreated control C8 cells (A) and PD treated cells (B) were elongated and displayed large normal nuclei. Cells exposed to CPT in the absence ((C), (E)) or presence ((D), (F)) of PD showed features of apoptosis ((C) and (D)) after 8 hours as well as vacuolization and secondary necrosis after 18 hours ((E) and (F)).
