The effectiveness of poultry stunning in producing swift slaughtering was analysed in response to the time needed for the chickens to become insensible upon neck cutting (Td) and the induction of myofiber apoptosis. In total, 49 chicken broilers (BW of 2.17 ± .24 kg) were sacrificed with pre-slaughter stunning, using a constant voltage stunner where the electric current varied between 7.2 to 124.3 mA, and without stunning. The electric current applied during stunning was found to have no effect on Td. Number of apoptotic myonuclei did not vary among stunned and unstunned meat. Apoptosis inducing factor (AIF) and caspase 3 expressions were also not detected in the meat samples of both stunned and unstunned groups at 1 d postmortem. Since the slaughtering process and stunning are associated with stress, the expression of 70 kDa-heat shock protein (Hsp70) was investigated. Moreover Hsp70 is also an inhibitor of apoptosis, by preventing the activation of AIF and apoptosome which stimulates caspase 3 activation. However, expression of Hsp70 was not induced in both stunned groups and unstunned groups. Together, this study found that poultry stunning does not affect Td and myofiber apoptosis.
Epstein-Barr virus (EBV)-encoded BARF1 (BamH1-A Rightward Frame-1) is expressed in EBV-positive malignancies such as nasopharyngeal carcinoma, EBV-associated gastric cancer, B-cell lymphoma and nasal NK/T-cell lymphoma, and has been shown to have an important role in oncogenesis. However, the mechanism by which BARF1 elicits its biological effects is unclear. We investigated the effects of BARF1 silencing on cell proliferation and apoptosis in EBV-positive malignant cells. We observed that BARF1 silencing significantly inhibits cell proliferation and induces apoptosis-mediated cell death by collapsing the mitochondrial membrane potential in AG876 and Hone-Akata cells. BARF1 knockdown up-regulates the expression of pro-apoptotic proteins and downregulates the expression of anti-apoptotic proteins. In BARF1-down-regulated cells, the Bcl-2/BAX ratio is decreased. The caspase inhibitor z-VAD-fmk was found to rescue siBARF1-induced apoptosis in these cells. Immunoblot analysis showed significant increased levels of cleaved caspase 3 and caspase 9. We observed a significant increase in cytochrome c level as well as the formation of apoptosome complex in BARF1-silenced cells. In conclusion, siRNA-mediated BARF1 down-regulation induces caspase-dependent apoptosis via the mitochondrial pathway through modulation of Bcl-2/BAX ratio in AG876 and Hone-Akata cells. Targeting BARF1 using siRNA has the potential to be developed as a novel therapeutic strategy in the treatment of EBV-associated malignancies.