Research Article
Oleuropein-Induced Apoptosis Is Mediated by Mitochondrial Glyoxalase 2 in NSCLC A549 Cells: A Mechanistic Inside and a Possible Novel Nonenzymatic Role for an Ancient Enzyme
Figure 2
OP induces apoptosis through a mechanism involving SOD2-mediated superoxide anion- (O2⋅--) dependent mGlo2 upregulation in NSCLC A549 cells. (a) Superoxide dismutase 2 (SOD2) activity and (b) superoxide anion (O2⋅-) level in untreated (0 μM) and oleuropein- (OP-) treated A549 cells. Under 150 μM OP exposure, SOD2 silencing by small interfering RNA (siSOD2) (c) significantly reversed (d) O2⋅- levels, (e) mitochondrial Glo2 expression, and (f) apoptosis, evaluated by active caspase-3 expression. Western blots were stripped of the bound Abs and reprobed with anti-β-actin or anti-Cox-IV, to confirm equal loading. The western blots shown are representative of three separate experiments. Histograms indicate the of three different cultures each of which was tested in triplicate. siCtr: control (nonspecific siRNA), (-) untreated, and (+) treated cells; , , and versus unexposed cells; ° versus OP-treated cells.
| (a) |
| (b) |
| (c) |
| (d) |
| (e) |
| (f) |