PROTECTION OF HUMAN ENDOTHELIAL-CELLS FROM OXIDANT INJURY BY ADENOVIRUS-MEDIATED TRANSFER OF THE HUMAN CATALASE CDNA

In a variety of disorders, endothelial cells are exposed to high level s of oxidants, generated within the cells and/or consequent to local i nflammation. In the context of the sensitivity of endothelial cells to oxidant stress, particularly related to H2O2, we have designed a repl ication deficient recombinant adenovirus containing the human catalase cDNA (AdCL) to transfer the catalase cDNA to the endothelial cells, i n order to augment intracellular anti-H2O2 protection. Human umbilical vein endothelial cells that were not infected or infected with contro l adenovirus maintained low levels of catalase mRNA. Endothelial cells infected with AdCL expressed AdCL-driven exogenous catalase mRNA, as early as 24 hr and at least for 7 days. Catalase protein levels were i ncreased significantly over controls in cells infected with AdCL, as w ere catalase activity levels, with catalase activity correlated closel y with levels of catalase protein. Importantly, when the endothelial c ells were exposed to 500 muM H2O2, all the AdCL infected endothelial c ells survived, compared to only 37% of the control cells. Thus, a reco mbinant adenovirus containing the human catalase cDNA is able to infec t human endothelial cells in vitro and express high levels of function al intracellular catalase, protecting the cells against H2O2-mediated oxidant stress. These observations support the feasibility of the tran sfer of catalase cDNA to human endothelium to protect against oxidant injury.