Phosphoproteomic profile of differentially phosphorylated proteins in human myocardium before and after cardiac surgery utilizing cardioplegia and cardiopulmonary bypass.

Abstract

ObjectiveCardiac surgery using cardioplegia and cardiopulmonary bypass(CP/CPB) subjects myocardium to reversible ischemic injury that can impair cardiac function. Changes in myocardial contractile activity are likely regulated in part via acute protein phosphorylation. We performed the following study to determine changes in human myocardial protein phosphorylation following CP/CPB.MethodsRight atrial appendage was collected from patients pre and post‐CP/CPB and subjected to two‐dimensional electrophoresis, phospho‐protein staining, image analysis, and tandem mass spectrometry.Results48 spots were consistently increased in the post CP/CPB group vs pre CP/CPB. There were no consistent changes in the remaining 24 consistently detected proteins post CP/CPB. Some of the identified proteins that changed in phosphorylation included: the cytoskeletal proteins tropomyosin α1, cardiac troponin I, atrial myosin light chain (MLC)‐2, atrial MLC‐4, actin, and heat shock protein 27; the metabolic proteins: ATP‐synthase subunit beta, phosphoglycerate mutase 2, and L‐lactate dehydrogenase B chain; the membrane signaling proteins 14‐3‐3εand annexin A5.ConclusionCP/CPB modifies the phosphorylation of specific cytoskeletal, metabolic, signaling, and serum proteins which may have significant implications for CP/CPB‐induced myocardial stunning. (NIH: HL046716,HL093352)