Bcl-xL Gene Transfer Inhibits Bax Translocation and Prolongs Cardiac Cold Preservation Time in Rats

Abstract
Background— Apoptosis is an important cause of early graft loss after heart transplantation. Bcl-xL was reported to protect the heart against normothermic ischemia and reperfusion injury. In this study, we determined whether overexpression of Bcl-xL could inhibit tissue injury resulting from prolonged cold preservation followed by warm reperfusion of heart transplants. Methods and Results— Lewis rat hearts were transduced with an adenovirus vector harboring Bcl-xL cDNA (AxCAhBclxL) 4 days before collection of tissue. After preservation in University of Wisconsin solution at 4°C for 24 hours, the heart was either perfused with a Langendorff device ex vivo or used for heterotopic heart transplantation in vivo. Bcl-xL gene transfer significantly reduced the infarct size (23.0±2.6% versus 47.7±7.0% in saline control and 48.6±6.1% in vector control, P P c release from the mitochondria; it also significantly decreased cardiac cell apoptosis and improved graft survival rate after long cold preservation, followed by warm reperfusion. Conclusions— Bcl-xL gene transfer inhibited the translocation of Bax and prolonged the cold preservation time of cardiac transplants. This may be a potential therapeutic method in clinical practice.