Activation of apoptotic caspase-3 and nitric oxide synthase-2 in buccal mucosa with chronic alcohol ingestion

Apoptosis, the process of programmed cell death, involves activation of caspase proteases cascade that remains under the regulatory control of nitric oxide. In this study, we investigated the activity of a key apoptotic protease, caspase-3, and the expression of nitric oxide synthase-2 (NOS-2) associated with buccal epithelial cells apoptosis induced by chronic ethanol diet. The assays revealed that a 7.9-fold enhancement in buccal epithelial cells apoptosis, observed in the alcohol diet group, was accompanied by a 37.6-fold increase in caspase-3 activity and a 10.1-fold increase in NOS-2. Furthermore, the expression of NOS-2 showed a positive correlation (r = 0.92) with the extent of changes induced in caspase-3 activity. These results implicate caspase-3 in the process of alcohol-induced epithelial cells apoptosis, and point towards participation of NOS-2 in the amplification of the cell death signaling cascade.