Bcl-2-mediated inhibition of apoptosis in rat cardiac allografts worsens development of graft coronary artery disease.
BACKGROUND
We hypothesized that adenovirally mediated Bcl-2 transfection of donor hearts would reduce the apoptosis that occurs during acute rejection while worsening the development of chronic graft coronary artery disease (GCAD).


METHODS
PVG donor hearts were treated with either AdvBcl-2 or AdvNull virus before heterotopic transplantation into ACI rats. Bcl-2 expression was assessed on post-operative day 4 (POD) 4 by western blot. Apoptosis was measured using (99m)Technetium-bound-annexin V imaging and caspase 3 activity assay. Allograft survival was determined in a separate cohort of animals. Long-term-treated animals were then assessed for measures of GCAD on POD 90.


RESULTS
Western blot analysis showed upregulation of Bcl-2 expression in AdvBcl-2-treated hearts. (99m)Tc-annexin V images demonstrated decreased uptake in the AdvBcl-2 group (1.41 +/- 0.33% vs 1.94 +/- 0.37%, p = 0.026). Caspase 3 activity was also significantly lower in this treatment group (0.112 +/- 0.032 vs 0.204 +/- 0.096, p = 0.049). Allograft survival was similar in both groups, respectively (7.7 +/- 1.2 vs 6.8 +/- 1.5 days, p = 0.340). GCAD, as determined by percent luminal narrowing (5.9 +/- 6.1% vs 1.6 +/- 1.5%, p = 0.039), intima-to-media ratio (5.1 +/- 5.1% vs 1.5 +/- 1.7%, p = 0.040) and percent of affected vessels (15.1 +/- 9.9% vs 5.3 +/- 4.4%, p = 0.009), was higher for the AdvBcl-2 group.


CONCLUSIONS
Treatment of cardiac allografts with AdvBcl-2 resulted in a reduction of apoptosis that did not significantly improve short-term graft survival, but worsened chronic GCAD.
Kown
Murray H
MH
Department of Cardiothoracic Surgery, Stanford University School of Medicine, Stanford, California, USA.
Miniati
Douglas N
DN
Jahncke
Christina L
CL
Lijkwan
Maarten A
MA
Murata
Seiichiro
S
Koransky
Mark L
ML
Blankenberg
Francis G
FG
Strauss
H William
HW
Robbins
Robert C
RC
D000818:Animals; D017304:Annexin A5 / Q000378:metabolism; D017209:Apoptosis; D053148:Caspase 3; D020169:Caspases / Q000378:metabolism; D003327:Coronary Disease / Q000209:etiology*; D015870:Gene Expression; D019254:Genes, bcl-2; D016027:Heart Transplantation; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D016019:Survival Analysis; D014162:Transfection; D014184:Transplantation, Homologous
D017304:Annexin A5; C505410:Casp3 protein, rat; D053148:Caspase 3; D020169:Caspases