Reduction of ischemia-reperfusion injury of the liver by in vivo adenovirus-mediated gene transfer of the antiapoptotic bcl-2 gene

Objective To examine the possibility of reducing ischemia-reperfusion injury (I/R inj ury) to the mouse liver by in vivo adenovirus-mediated gene transfer of the antiapoptotic human Bcl-2 gene. Summary Background Data Ischemia-reperfusion injury has been demonstrated in a number of clinically relevant diseases such as myocardial infarction, cerebrovascular disease, sepsis, peripheral vascular disease, and organ transplantation. In this reg ard, apoptosis plays a central role. Methods Normal C57BL/6 mice were used. An adenovirus (Delta E1) vector containing t he human Bcl-2 gene was developed in the authors' laboratory. An adenovirus vector encoding an irrelevant gene (beta-galactosidase, AdCMVLacZ) was use d as a control. Taking advantage of the hepatotropic properties of adenovir us vectors, gene transfer was performed with 1 x 10(9) plaque-forming units by intravenous tail injection, 48 hours before the ischemic injury. Ischem ic-reperfusion injury was induced by temporal and segmental occlusion of he patic blood flow. Aspartate aminotransferase, alanine aminotransferase, and lactate dehydrogenase activity was measured using standard assays, Liver b iopsies were obtained before and 6 hours after I/R injury for morphologic a ssessment, and apoptosis was determined in situ with a histochemical assay. Results The expression of AdCMVhBcl-2 vector was confirmed by reverse transcription -polymerase chain reaction and functionally validated in apoptotic studies in endothelial cells, Expression of the Bcl-2 gene protects against I/R inj ury, as shown by a significant decrease in transaminases (p < 0.05) and nec rosis and apoptosis (p < 0.001), and permanent survival (p < 0.0001), compa red with sham-operated animals and animals treated with AdCMVLacZ. Conclusions Genetic modification of the liver to induce cytoprotection has potential ap plications to prevent I/R injury to the liver in surgical interventions, in cluding liver transplantation.