Indices of apoptosis activation after blood cardioplegia and cardiopulmonary bypass.
BACKGROUND
Cardioplegic arrest (CA) using cold blood cardioplegia (CBC) has been reported to reduce ischemia-reperfusion (IR)-induced myocardial injury via apoptosis. We studied key apoptotic mediators via the caspase-dependent and intrinsic pathways as well as poly(ADP)-ribosylating protein (PARP) activity in myocardial and peripheral tissues after CA and cardiopulmonary bypass (CBP).


RESULTS
Right atrial (RA) and skeletal muscle(SM) was harvested from cardiac surgical patients with similar baseline characteristics (N =6) before and after CPB and CBC. Total and modified caspase-3, Bcl-2, Bad, apoptosis-inducing factor (AIF), and PARP were quantified by immunoblotting. Terminal caspase-3 activity was assessed and immunohistochemistry was performed for PARP and AIF. TUNEL staining was used for identification of apoptotic cells. Microarray gene expression analysis was performed using Affymetrix U95 GeneChip. In RA tissue, CA with CBC significantly increased phosphorylation of Bcl-2 (Ser70), Bad (Ser112) (2.63+/-0.4 and 1.77+/-0.3-fold respectively; P<0.05), and cleavage of the downstream caspase 3 (1.45+/-0.1-fold; P<0.05). There was no significant change in total protein levels. Also, there was an increase in mature AIF (57 kDa) levels (1.22+/-0.01-fold; P<0.05) and a trend toward nuclear translocation on histological staining. Caspase 3 activity was increased 1.5+/-0.14-fold (P<0.05). The number of apoptotic cells in atrial tissue increased after compared with before CPB/CA using TUNEL staining (1.55+/-0.66 versus 0.325+/-0.05%, respectively; P=0.03). In contrast, SM samples did not show any of the changes observed in RA tissue after CPB.


CONCLUSIONS
Despite optimal current surgical myocardial protection, we found that CA with CBC induced both programmed cell death and survival signaling in myocardial tissue.
Ramlawi
Basel
B
Division of Cardiothoracic Surgery, Department of Surgery, Beth Israel Deaconess MedicalCenter, LMOB 2A, 110 Francis St, Boston, Massachusetts 02215, USA.
Feng
Jun
J
Mieno
Shigetoshi
S
Szabo
Csaba
C
Zsengeller
Zsuzsanna
Z
Clements
Richard
R
Sodha
Neel
N
Boodhwani
Munir
M
Bianchi
Cesario
C
Sellke
Frank W
FW
D000368:Aged; D017209:Apoptosis; D051033:Apoptosis Inducing Factor / Q000032:analysis; D020517:Atrial Appendage / Q000737:chemistry / Q000473:pathology; D001769:Blood; D002315:Cardiopulmonary Bypass / Q000009:adverse effects*; D053148:Caspase 3; D020169:Caspases / Q000032:analysis; D015687:Cell Hypoxia; D005260:Female; D020869:Gene Expression Profiling; D006324:Heart Arrest, Induced / Q000009:adverse effects / Q000379:methods*; D006801:Humans; D020287:In Situ Nick-End Labeling; D008297:Male; D008875:Middle Aged; D009124:Muscle Proteins / Q000096:biosynthesis / Q000235:genetics; D018482:Muscle, Skeletal / Q000737:chemistry / Q000473:pathology; D015425:Myocardial Reperfusion; D020411:Oligonucleotide Array Sequence Analysis; D018384:Oxidative Stress; D010766:Phosphorylation; D011065:Poly(ADP-ribose) Polymerases / Q000032:analysis; D011499:Protein Processing, Post-Translational; D021381:Protein Transport; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000032:analysis; D014443:Tyrosine / Q000031:analogs & derivatives / Q000032:analysis; D051025:bcl-Associated Death Protein / Q000032:analysis
C494829:AIFM1 protein, human; D051033:Apoptosis Inducing Factor; C494819:BAD protein, human; D009124:Muscle Proteins; D019253:Proto-Oncogene Proteins c-bcl-2; D051025:bcl-Associated Death Protein; C002744:3-nitrotyrosine; D014443:Tyrosine; D011065:Poly(ADP-ribose) Polymerases; C505407:CASP3 protein, human; D053148:Caspase 3; D020169:Caspases