Fig. 7.

Ectopic expression of dominant negative Akt enhances rapamycin’s prevention from Cd-induced neuronal cell death. PC12 cells, infected with recombinant adenovirus expressing dominant negative (dn) Akt (Ad-dn-Akt) or GFP (Ad-GFP) (as control), were pretreated with rapamycin for 48 h, followed by exposure to Cd (20 μM) for 4 h (for Western blotting) or 24 h (for live cell assay and DAPI staining). A) Total cell lysates were subjected to Western blot analysis using indicated antibodies. The blots were probed for β-tubulin as a loading control. Similar results were observed in at least three independent experiments. B) Live cells were detected by counting viable cells using trypan blue exclusion. C) Apoptotic cells were evaluated by nuclear fragmentation and condensation (arrows) using DAPI staining. Scale bar: 20 μm. D) The percentages of cells with fragmented nuclei were quantified. B and D) Rapamycin exhibited more obvious prevention from Cd-induced B) cell viability reduction and D) apoptosis in Ad-dn-Akt-infected group than in Ad-GFP-infected group. Results are presented as mean ± SEM (n = 5). ^a p < 0.05, difference with control group; ^b p < 0.05, Ad-dn-Akt group versus Ad-GFP group.