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Circulation. 2013 Sep 10;128(11 Suppl 1):S144-51. doi: 10.1161/CIRCULATIONAHA.112.000332.

Altered apoptosis-related signaling after cardioplegic arrest in patients with uncontrolled type 2 diabetes mellitus.

Author information

1
Division of Cardiothoracic Surgery, Department of Surgery, Rhode Island Hospital, Alpert Medical School of Brown University, Providence, RI.

Abstract

BACKGROUND:

We investigated the effects of cardioplegic arrest and reperfusion (CP/Rep) on myocardial apoptosis and key apoptotic mediators, such as apoptosis-inducing factor, caspase 3, caspase 8, caspase 9, poly(adenosine diphosphate-ribose) polymerase, B-cell lymphoma 2 (Bcl-2) family proteins, and protein kinase C (PKC), in uncontrolled type 2 diabetic, controlled type 2 diabetic, and nondiabetic patients.

METHODS AND RESULTS:

Right atrial tissue was harvested pre- and post-CP/Rep from uncontrolled type 2 diabetic patients (hemoglobin A1c=9.6 ± 0.25), controlled type 2 diabetic patients (hemoglobin A1c=6.5 ± 0.15), and nondiabetic patients (hemoglobin A1c=5.4 ± 0.12) undergoing coronary artery bypass grafting (n=8/group). Terminal deoxynucleotidyl transferase dUTP nick-end labeling staining was used for the identification of apoptotic cells. Total and modified apoptosis-inducing factor, Bcl-2 family proteins, phospho-PKC-α, phospho-PKC-β1, and poly(adenosine diphosphate-ribose) polymerase were quantified by immunoblotting or immunohistochemistry. At baseline, the number of apoptotic cells and expression of total apoptosis-inducing factor, Bcl-2, Bak, and Bax in the pre-CP/Rep atrial tissue from uncontrolled type 2 diabetic patients were significantly increased compared with those of nondiabetic or controlled type 2 diabetic patients (P<0.05). After CP/Rep, the amount of apoptotic cells, apoptosis-inducing factor, phospho-Bad, phospho-PKC-α, phospho-PKC-β1, and cleaved poly(adenosine diphosphate-ribose) polymerase in post-CP/Rep atrial tissue were increased in all 3 groups compared with pre-CP/Rep. These increases after CP/Rep were more pronounced in the uncontrolled type 2 diabetic group. In addition, there were significant increases in the expression of cleaved caspase 8 and caspase 9 in the basal and post-CP/Rep atrium of uncontrolled type 2 diabetic group compared with nondiabetic or controlled type 2 diabetic group.

CONCLUSIONS:

Uncontrolled diabetes mellitus is associated with increases in myocardial apoptosis and expression of key apoptosis mediators at baseline and in the setting of CP/Rep.

KEYWORDS:

apoptosis; cardioplegia; cardiopulmonary bypass; coronary artery bypass surgery; diabetes mellitus

PMID:
24030399
PMCID:
PMC3815526
DOI:
10.1161/CIRCULATIONAHA.112.000332
[Indexed for MEDLINE]
Free PMC Article

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