Abstract
Abstract: :
Purpose:To determine the role of p53 in apoptosis after ischemia/reperfusion in rat retina. To assess the role of p53 inhibitor (Pifithrin α, Calbiochem, CA) and evaluate changes in Bax, one of the pro–apoptotic target protein of p53 after ischemia/reperfusion in rat retina. Methods:Pifithrin α (0.5mg) and vehicle was injected intraperitoneally 30 minutes before induction of ischemia (75 minutes) followed by reperfusion. Animals were sacrificed at 1 day, 2 day and 3 days after ischemia/reperfusion. Retinas were processed for p53 and Bax proteins analysis by western blot. As a corollary experiment, HeLa cells were subjected to doxorubicin (to induce p53) and Pifithrin α treatment and were analyzed by western blot for p53. Results:The amount of p53 protein increased at all time points after ischemia/reperfusion in the retina. The amount of p53 protein decreased after the treatment with the Pifithrin α at 1, 2 and 3 days after ischemia/reperfusion. Bax protein significantly reduced after 2 and 3 days of ischemia/ reperfusion with Pifithrin α treatment however, no appreciable difference was noticed at 1 day after ischemia/reperfusion. The amount of p53 protein was significantly reduced in doxorubicin treated HeLa cells after treatment with Pifithrin α. Conclusion:P53 protein is upregulated after the ischemia/reperfusion in the rat retina. Pifithrin α treatment reduces the Bax protein (down stream activator of apoptosis) expression in retina after ischemia reperfusion suggesting the role of p53 in retinal apoptosis.
Keywords: apoptosis/cell death • ischemia • retina