Figure 2.
The caspase inhibitor Z-VAD inhibits the caspase-3 activation and the increases in Aβ generation induced by 2% isoflurane in H4-APP cells.
A
, Treatment with 2% isoflurane (lanes 5, 6) induces caspase-3 cleavage (activation) compared with control conditions (lanes 1, 2) or Z-VAD (100 μm) treatment (lanes 3, 4). The Z-VAD treatment inhibits the caspase-3 cleavage induced by 2% isoflurane (lane 7, 8). There is no significant difference in the amounts of β-actin in the H4-APP cells with the above treatments.
B
, Quantitation of the Western blot shows that the 2% isoflurane treatment (black bar) increases caspase-3 activation compared with control conditions (white bar) or the Z-VAD (100 μm) treatment (gray bar), normalized to β-actin levels. The isoflurane-induced caspase-3 activation is inhibited by the Z-VAD treatment (striped bar).
C
, Z-VAD inhibits the isoflurane-induced changes in APP processing in H4-APP cells. Treatment with 2% isoflurane (lanes 5, 6) decreases the protein levels of APP-FL and APP-CTFs compared with control conditions (lanes 1, 2) or Z-VAD (100 μm) treatment (lanes 3, 4). The Z-VAD treatment (lanes 7, 8) inhibits the isoflurane-induced decreases in the protein levels of APP-FL and APP-CTFs. There is no significant difference in the amounts of β-actin in the H4-APP cells with all of the above treatments.
D
, Quantification of the Western blot shows that 2% isoflurane treatment (black bar) decreases the protein levels of APP-FL compared with the control condition (white bar) or Z-VAD treatment (gray bar), normalized to β-actin levels. The isoflurane-induced decrease in the protein levels of APP-FL is inhibited by the Z-VAD treatment (striped bar).
E
, Quantification of the Western blot also shows that 2% isoflurane treatment (black bar) decreases the protein levels of APP-CTFs compared with the control condition (white bar) or Z-VAD treatment (gray bar), normalized to β-actin levels. The isoflurane-induced decrease in the protein levels of APP-CTFs is also inhibited by the Z-VAD treatment (striped bar).
F
, Z-VAD inhibits the isoflurane-induced increases in Aβ generation. Treatment with 2% isoflurane (black bar) increases the levels of Aβ40 compared with the control condition (white bar). Z-VAD treatment alone (gray bar) does not change the levels of Aβ40; however, Z-VAD treatment inhibits the isoflurane-induced increases in the levels of Aβ40. Data are means ± SD; n = 6 for each experimental group. t test is used to compare the difference between control conditions and 2% isoflurane treatment (*p < 0.05; **p < 0.01) and the difference between 2% isoflurane plus DMSO treatment and 2% isoflurane plus Z-VAD treatment (#
p < 0.05; ##
p < 0.01).