Abstract 96: Thioredoxin-1 Is Essential for Hydrogen Sulfide-Mediated Cardioprotection in the Setting of Ischemic-Induced Heart Failure
Background: Numerous studies have reported the cytoprotective effects of hydrogen sulfide (H2S) in various models of myocardial injury. Here we examined the role that thioredoxin-1 (Trx1) plays in mediating the protective effects of H2S in a model of heart failure.
Methods and Results: Mice were subjected to 60 min of left coronary artery ischemia followed by 4 wks of reperfusion (R) at which time left ventricular dimensions and function were assessed. Mice received saline (Veh) or H2S in the form of sodium sulfide (Na2S, 100 μ g/kg) at the time of R followed by daily i.v. injections for the first 7 days of R. Mice treated with Na2S experienced less left ventricular dilatation and hypertrophy, displayed improved left ventricular ejection fraction, and displayed improved contractility and relaxation when compared to Veh-treated mice. Studies aimed at evaluating the underlying cardioprotective mechanisms found that Na2S treatment increased the expression of Trx1. Further analysis revealed that this was accompanied by an increase in phosphorylation of apoptosis signaling kinase-1 (ASK1) at serine residue 966 (inhibitory site), as well as a decrease in the phosphorylation of JNK and p38 (downstream targets of ASK1). We also found that Na2S treatment did not improve cardiac dilatation, cardiac dysfunction, or cardiac hypertrophy in cardiac specific Trx1 dominant negative transgenic (Trx1 dnTg) mice when compared to Veh-treated mice.
Conclusion: These findings provide important information that the upregulation of cardiac Trx1 by H2S in the setting of ischemic-induced heart failure sets into motion events, including ASK1 inhibition, which ultimately leads to cardioprotection.
- © 2012 by American Heart Association, Inc.