Published online before print July 16, 2009, doi: 10.1161/CIRCRESAHA.109.199919
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Submitted on April 25, 2009
Revised on July 5, 2009
Accepted on July 6, 2009
Hydrogen Sulfide Mediates Cardioprotection Through Nrf2 Signaling
John W. Calvert ;
From the Department of Surgery (J.W.C., D.J.L.), Division of Cardiothoracic Surgery, Emory University School of Medicine, Atlanta, Ga; Department of Medicine (S.J., S.G., A.R.), Division of Cardiology, Albert Einstein College of Medicine, Bronx, NY; Department of Molecular Cardiovascular Biology (J.W.E.), Cincinnati Children's Hospital Medical Center, Ohio; and Department of Pathology (C.B.P., C.G.K.), Louisiana Statue University Health Sciences Center, Shreveport.
* To whom correspondence should be addressed. E-mail: dlefer{at}emory.edu.
Rationale: The recent emergence of hydrogen sulfide (H2S) as a potent cardioprotective signaling molecule necessitates the elucidation of its cytoprotective mechanisms.
Objective: The present study evaluated potential mechanisms of H2S-mediated cardioprotection using an in vivo model of pharmacological preconditioning.
Methods and Results: H2S (100 µg/kg) or vehicle was administered to mice via an intravenous injection 24 hours before myocardial ischemia. Treated and untreated mice were then subjected to 45 minutes of myocardial ischemia followed by reperfusion for up to 24 hours, during which time the extent of myocardial infarction was evaluated, circulating troponin I levels were measured, and the degree of oxidative stress was evaluated. In separate studies, myocardial tissue was collected from treated and untreated mice during the early (30 minutes and 2 hours) and late (24 hours) preconditioning periods to evaluate potential cellular targets of H2S. Initial studies revealed that H2S provided profound protection against ischemic injury as evidenced by significant decreases in infarct size, circulating troponin I levels, and oxidative stress. During the early preconditioning period, H2S increased the nuclear localization of Nrf2, a transcription factor that regulates the gene expression of a number of antioxidants and increased the phosphorylation of protein kinase C
and STAT-3. During the late preconditioning period, H2S increased the expression of antioxidants (heme oxygenase-1 and thioredoxin 1), increased the expression of heat shock protein 90, heat shock protein 70, Bcl-2, Bcl-xL, and cyclooxygenase-2 and also inactivated the proapoptogen Bad.
Conclusions: These results reveal that the cardioprotective effects of H2S are mediated in large part by a combination of antioxidant and antiapoptotic signaling.
Key words: hydrogen sulfide • cardioprotection • antioxidant signaling • myocardial infarction • Nrf2