The purpose of this proposal is to elucidate the mechanism whereby S-nitrosation (SNO) confers cardioprotection from ischemia-reperfusion injury. S-nitrosation is a recently described protein modification in which a nitric oxide moiety is covalently attached to a thiol group of a cysteine residue, leading to the formation of S-nitrosothiols. SNO is a reversible modification that has been shown to modify the activity of target proteins. Additionally, SNO has been reported to protect thiol groups from oxidative damage. Potential sources for the endogenous production of nitric oxide in cardiac myocytes include nitric oxide synthase and non-enzymatic means. Brief occlusion of a coronary artery generally results in cardiac ischemia-reperfusion injury. This type of injury can lead to cardiac dysfunction, which is initially reversible (myocardial stunning) and later irreversible (infarction), and ventricular arrhythmias. However, cardioprotective effects result from ischemic preconditioning, a protective mechanism of the heart that develops from several brief episodes of ischemia. This cardioprotective measure has been reported to increase S-nitrosation formation in the cardiac myocyte. Furthermore, hearts from females exhibit endogenous cardioprotection, which has been shown to be NOS-dependent. However, studies have yet to fully characterize the signaling pathways necessary for SNO formation or the mechanism(s) through which SNO formation exerts cardioprotection. Therefore, further studies are needed in order to examine the role of S-nitrosation in cardioprotection. The role of S-nitrosation will be addressed in the specific aims of this proposal and are as follows: 1) determine the specific signaling pathways that are necessary for S-nitrosation formation in cardioprotection, 2) identify the specific cysteine residues that are SNO during cardioprotection, and 3) determine if S-nitrosation exerts cardioprotective effects by shielding critical thiol groups from oxidative damage. The overall hypotheses of this proposal are as follows: 1.) SNO formation and cardioprotection is initiated upon activation of specific signaling pathways, 2.) SNO occurs at specific cysteine residues on key target proteins, and 3.) SNO provides cardioprotection by blocking against oxidative damage.

Public Health Relevance

The specific aims of the proposed study will determine the role of S-nitrosation in cardioprotection and resolve the mechanism through which S- nitrosation serves to protect against ischemia-reperfusion injury. These results will also help to clarify inconsisties in the literature that relate to the role of nitric oxide synthase in cardioprotection. Additionally, these results may allow for improvements in the treatment of human cardiac patients by identifying novel targets for therapeutic intervention.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Postdoctoral Individual National Research Service Award (F32)
Project #
5F32HL096142-03
Application #
8085866
Study Section
Special Emphasis Panel (ZRG1-F10-H (21))
Program Officer
Meadows, Tawanna
Project Start
2009-06-15
Project End
2012-06-14
Budget Start
2011-06-15
Budget End
2012-06-14
Support Year
3
Fiscal Year
2011
Total Cost
$51,326
Indirect Cost
Name
Johns Hopkins University
Department
Pediatrics
Type
Schools of Medicine
DUNS #
001910777
City
Baltimore
State
MD
Country
United States
Zip Code
21218
Shao, Qin; Casin, Kevin M; Mackowski, Nathan et al. (2017) Adenosine A1 receptor activation increases myocardial protein S-nitrosothiols and elicits protection from ischemia-reperfusion injury in male and female hearts. PLoS One 12:e0177315
Kovács, Mária; Kiss, Attila; Gönczi, Márton et al. (2015) Effect of sodium nitrite on ischaemia and reperfusion-induced arrhythmias in anaesthetized dogs: is protein S-nitrosylation involved? PLoS One 10:e0122243
Sun, Junhui; Aponte, Angel M; Kohr, Mark J et al. (2013) Essential role of nitric oxide in acute ischemic preconditioning: S-nitros(yl)ation versus sGC/cGMP/PKG signaling? Free Radic Biol Med 54:105-12
Kohr, Mark J; Aponte, Angel; Sun, Junhui et al. (2012) Measurement of S-nitrosylation occupancy in the myocardium with cysteine-reactive tandem mass tags: short communication. Circ Res 111:1308-12
Sun, Junhui; Kohr, Mark J; Nguyen, Tiffany et al. (2012) Disruption of caveolae blocks ischemic preconditioning-mediated S-nitrosylation of mitochondrial proteins. Antioxid Redox Signal 16:45-56
Murphy, Elizabeth; Kohr, Mark; Sun, Junhui et al. (2012) S-nitrosylation: a radical way to protect the heart. J Mol Cell Cardiol 52:568-77
Murphy, Elizabeth; Lagranha, Claudia; Deschamps, Anne et al. (2011) Mechanism of cardioprotection: what can we learn from females? Pediatr Cardiol 32:354-9
Kohr, Mark J; Aponte, Angel M; Sun, Junhui et al. (2011) Characterization of potential S-nitrosylation sites in the myocardium. Am J Physiol Heart Circ Physiol 300:H1327-35
Kohr, Mark J; Sun, Junhui; Aponte, Angel et al. (2011) Simultaneous measurement of protein oxidation and S-nitrosylation during preconditioning and ischemia/reperfusion injury with resin-assisted capture. Circ Res 108:418-26
Wang, Honglan; Viatchenko-Karpinski, Serge; Sun, Junhui et al. (2010) Regulation of myocyte contraction via neuronal nitric oxide synthase: role of ryanodine receptor S-nitrosylation. J Physiol 588:2905-17