Profiling of cell stress protein expression in cardiac tissue of cardiosurgical patients undergoing remote ischemic preconditioning: implications for thioredoxin in cardioprotection

Abstract

BackgroundTransient episodes of ischemia in a remote organ (remote ischemic preconditioning, RIPC) can attenuate myocardial ischemia/reperfusion injury but the underlying mechanisms of RIPC in the target organ are still poorly understood. Recent animal studies suggested that the small redox protein thioredoxin may be a potential candidate for preconditioning-induced organprotection. Here we employed a human proteome profiler array to investigate the RIPC regulated expression of cell stress proteins and particularly of thioredoxin in heart tissue of cardiosurgical patients with cardiopulmonary bypass (CPB).MethodsRIPC was induced by four 5 minute cycles of transient upper limb ischemia/reperfusion using a blood pressure cuff. Right atrial tissue was obtained from patients receiving RIPC (N = 19) and control patients (N = 19) before and after CPB. Cell stress proteome profiler arrays as well as Westernblotting and ELISA experiments for thioredoxin (Thio-1) were performed employing the respective tissue samples.ResultsProtein arrays revealed an up-regulation of 26.9% (7/26; CA IX, Cyt C, HSP-60, HSP-70, pJNK, SOD2, Thio-1) of cell stress associated proteins in RIPC tissue obtained before CPB, while 3.8% (1/26; SIRT2) of the proteins were down-regulated. Array results for thioredoxin were verified by semi-quantitative Westernblotting studies which showed a significant up-regulation of thioredoxin protein levels in cardiac tissue samples of RIPC patients taken before CPB (RIPC: 5.36 ± 0.85 a.u.; control: 3.23 ± 0.39 a.u.; P < 0.05). Quantification of thioredoxin levels in tissue of RIPC and control patients by ELISA experiments further confirmed the Westernblotting results (RIPC: 0.30 ± 0.02 ng/mg protein; control: 0.24 ± 0.02 ng/mg protein; P < 0.05).ConclusionWe provide evidence for thioredoxin as a RIPC-induced factor in heart tissue of cardiosurgical patients and identified several cell stress associated proteins that are regulated by RIPC and may play a role in RIPC-mediated cardioprotection.Electronic supplementary materialThe online version of this article (doi:10.1186/s12967-015-0403-6) contains supplementary material, which is available to authorized users.

Nuclear Factor (Erythroid-Derived 2)-Like 2 and Thioredoxin-1 in Atherosclerosis and Ischemia/Reperfusion Injury in the Heart

“…Loss of Trx-1 then leads to an ''over''-adaptive response, which explains the opposite finding of an increase of Trx-1 24 h after the reperfusion phase (80). Analyzing Trx-1 levels in cardiac tissue biopsies collected from cardiopulmonary bypass surgeries revealed an increase of Trx-1 in patients who were preconditioned by four cycles of 5 min upper arm ischemia followed by a 5 min reperfusion phase (113). This reveals one possible molecular mechanism for the improved outcome, for example, in MI after applying IPC.…”

Modulation of signaling mechanisms in the heart by thioredoxin 1

“…Remote ischemic preconditioning (RIPC) in cardiac surgery patients led to increased levels of Trx1 in cardiac tissue, suggesting that Trx1 is an RIPC-induced factor that could potentially mediate RIPC-induced cardioprotection [62]. …”

Remote ischemic preconditioning attenuates intestinal mucosal damage: insight from a rat model of ischemia–reperfusion injury

“…Several authors have shown that RIPC is able to attenuate apoptotic events induced by I/R injury in different organs [4–6]. Besides the regulation of apoptosis, preventing oxidation of cellular macromolecules by increasing antioxidant capacity within the target tissue seems to be an equally important mechanism of RIPC-mediated organ protection [7–9]. RIPC effects may also be mediated by hypoxia-inducible factor-1α (HIF-1α), a key transcription factor regulating cellular adaptation to hypoxia [10, 11], although the underlying mechanisms are only poorly understood so far [12, 13].…”