Transplanted heart cardiomyocytes reveal continuous expression of antiapoptotic Bcl-2 protein.
BACKGROUND
Apoptotic mechanisms take place in cardiocyte death during acute heart graft rejection and remodeling by the mitochondrial pathway. This process is suppressed by Bcl-2 protein. Besides that, knowledge about cardiocyte antiapoptotic responses after heart transplantation is scanty. We sought to estimate Bcl-2 expression in the absence of rejection.


METHODS
The study group included endomyocardial biopsies taken at 1 week, 1 month, 1 through to 10 years after heart transplant, which showed rejection grade "0"; the control group were donor heart fragments.


METHODS
Bcl-2 expression was determined immunohistochemically by NP030 antibody (DAKO) and Envision-DAB. The intensity of staining was assessed semiquantitatively.


RESULTS
No Bcl-2 expression was seen in the controls; in the posttransplant groups, the significantly strongest sarcoplasmic reaction was observed at 1 week after heart transplant. Thereafter, the reaction decreased, and was weakest in the 3- and 5-year groups. From this time, Bcl-2 expression increased albeit without statistical significance. The intensity of the reaction showed no correlation with the time elapsed from heart transplant (Spearman r = 0.05; P > .05).


CONCLUSIONS
The expression of antiapoptotic Bcl-2 protein occurs during the entire posttransplant period, being probably a preservative and adaptative response.
Nozynski
J
J
Department of Cardiac Surgery & Transplantation, Silesian Center for Heart Disease, Zabrze, Poland.
Zakliczynski
M
M
Zembala-Nozynska
E
E
Konecka-Mrowka
D
D
Nikiel
B
B
Przybylski
R
R
Lange
D
D
Maruszewski
M
M
Zembala
M
M
D017209:Apoptosis; D001706:Biopsy; D005500:Follow-Up Studies; D006085:Graft Survival / Q000502:physiology; D016027:Heart Transplantation / Q000473:pathology / Q000502:physiology*; D006801:Humans; D007150:Immunohistochemistry; D009206:Myocardium / Q000166:cytology / Q000473:pathology*; D032383:Myocytes, Cardiac / Q000166:cytology / Q000502:physiology*; D011184:Postoperative Period; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism*; D012189:Retrospective Studies
D019253:Proto-Oncogene Proteins c-bcl-2