Effects of adenoviral up-regulation of bcl-2 on oxidative stress and graft coronary artery disease in rat heart transplants.
BACKGROUND
Bcl-2 has been shown to have antioxidant properties. Early oxidative stress is an important antigen-independent factor that contributes to the development of graft coronary artery disease (GCAD). We hypothesized that adenoviral up-regulation of bcl-2 would decrease early oxidative stress and inhibit GCAD after heart transplantation.


METHODS
PVG rat hearts were treated with adenovirus carrying the human bcl-2 gene (AdvBcl-2) or null adenovirus (AdvNull) then transplanted into the abdomens of PVG recipients. After 4 days of reperfusion to allow adenoviral gene expression, grafts were retransplanted into ACI rat recipients and reperfused for 4 or 8 hours or 90 days (cyclosporine A 7.5 mg/kg on postoperative day [POD] 0-9). Production of tumor necrosis factor (TNF)-alpha after 4 hours and oxidized glutathione (GSSG) after 8 hours indicated development of oxidative stress. 90-day allografts were assessed for GCAD by way of computerized morphometry.


RESULTS
Over-expression of bcl-2 at the time of allograft reperfusion was confirmed by Western blotting. Whereas AdvNull-treated hearts demonstrated elevated TNF-alpha levels after 4 hours and increased GSSG after 8 hours of reperfusion, AdvBcl-2-treated hearts were no different from nontransplanted hearts. AdvBcl-2 treatment also resulted in decreased luminal narrowing and intima-to-media ratio at POD 90.


CONCLUSIONS
Bcl-2 over-expression interrupts the development of oxidative stress in reperfused rat-heart allografts. Early up-regulation of bcl-2 also decreases GCAD, indicating the importance of early oxidative stress and the role that bcl-2 may play in the long-term function of heart transplants.
Miniati
Douglas N
DN
Department of Cardiothoracic Surgery, Stanford University School of Medicine, CA 94305, USA.
Lijkwan
Maarten A
MA
Murata
Seiichiro
S
Martens
Jasper
J
Coleman
Caroline T
CT
Hoyt
E Grant
EG
Robbins
Robert C
RC
D000256:Adenoviridae / Q000235:genetics; D000818:Animals; D015153:Blotting, Western; D003324:Coronary Artery Disease / Q000378:metabolism* / Q000473:pathology; D004195:Disease Models, Animal; D015967:Gene Expression Regulation, Viral; D019803:Glutathione Disulfide / Q000378:metabolism; D006085:Graft Survival; D016027:Heart Transplantation; D006801:Humans; D008297:Male; D009206:Myocardium / Q000378:metabolism; D018384:Oxidative Stress / Q000502:physiology*; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000235:genetics*; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D011912:Rats, Inbred ACI; D015427:Reperfusion Injury / Q000378:metabolism / Q000473:pathology; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism; D015854:Up-Regulation
D019253:Proto-Oncogene Proteins c-bcl-2; D012333:RNA, Messenger; D014409:Tumor Necrosis Factor-alpha; D019803:Glutathione Disulfide