Mitochondrial oxidative stress is associated with ischemia-reperfusion (I/R) injury. At the myocardial level of the post-ischemic heart, defective energy metabolism has been linked to marked overproduction of oxygen free radical(s). Available evidence indicates that [a] specific interactions between oxygen free radicals and respiratory chain proteins are critical in the I/R pathophysiology, and [b] oxygen free radical- induced oxidative stress can act as a redox signal to change the thiol redox state of mitochondria! proteins, subsequently triggering cellular events such as apoptosis, proliferation and senescence. Two mitochondrial proteins containing critical redox thiols, NADH dehydrogenase (NDH) and succinate ubiquinone reductase (SQR), are also catalytic components responsible for superoxide production in mitochondria. The broad long-term goal of this project is to elucidate the molecular mechanism of how oxygen free radical production in mitochondria contributes to the myocardial injury. The key hypotheses of superoxide generation and protein S-glutathiolation will be tested by pursuing the following specific aims using the isolated enzyme complex and post-ischemic hearts. [1] Determine the mechanism of superoxide production by NDH. [2] Determine the mechanism of superoxide production by SQR. [3] Elucidate the molecular mechanism of protein S-glutathiolation resulting from the major pathway of oxygen free radical production. [4] Evaluate protein S-glutathiolation and NDH/SQR-derived S- glutathiolation in post-ischemic hearts. Enzyme-mediated superoxide production will be measured by EPR spin trapping and immobilized enzyme EPR (IE-EPR). Enzyme-mediated NO consumption rates will be measured by electrochemical detection using a NO electrode. Protein-derived S-glutathiolation and protein radical formation will be detected by immunoblotting. Protein radical(s), reactive thiol(s), and glutathione-binding (GS-binding) domain(s) will be identified by mass spectrometry and peptide mapping. The functional role of each identified domain will be defined by immunochemistry using specific antibodies against conformational epitope peptides. The utilization of protein S-glutathiolation as a biomarker of redox change resulting from oxidative stress will be evaluated in the systems of post- ischemic heart. Results from this proposal will provide fundamental information concerning the pathophysiological role of oxygen free radicals and protein redox thiol(s) in mitochondrial dysfunction, and potentially improve clinical diagnosis, therapeutics, and prevention of heart diseases.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Project (R01)
Project #
5R01HL083237-04
Application #
7651083
Study Section
Myocardial Ischemia and Metabolism Study Section (MIM)
Program Officer
Liang, Isabella Y
Project Start
2006-08-01
Project End
2009-12-31
Budget Start
2009-08-01
Budget End
2009-12-31
Support Year
4
Fiscal Year
2009
Total Cost
$364,125
Indirect Cost
Name
Ohio State University
Department
Internal Medicine/Medicine
Type
Schools of Medicine
DUNS #
832127323
City
Columbus
State
OH
Country
United States
Zip Code
43210
Kang, Patrick T; Chen, Chwen-Lih; Lin, Paul et al. (2018) Mitochondrial complex I in the post-ischemic heart: reperfusion-mediated oxidative injury and protein cysteine sulfonation. J Mol Cell Cardiol 121:190-204
Chen, Yeong-Renn (2018) Comparing cardioprotetion by DiOHF intervention and ischemic preconditioning. Int J Cardiol 259:163-165
Zhang, Liwen; Chen, Chwen-Lih; Kang, Patrick T et al. (2017) Differential protein acetylation assists import of excess SOD2 into mitochondria and mediates SOD2 aggregation associated with cardiac hypertrophy in the murine SOD2-tg heart. Free Radic Biol Med 108:595-609
Kang, Patrick T; Chen, Chwen-Lih; Lin, Paul et al. (2017) Impairment of pH gradient and membrane potential mediates redox dysfunction in the mitochondria of the post-ischemic heart. Basic Res Cardiol 112:36
Griendling, Kathy K; Touyz, Rhian M; Zweier, Jay L et al. (2016) Measurement of Reactive Oxygen Species, Reactive Nitrogen Species, and Redox-Dependent Signaling in the Cardiovascular System: A Scientific Statement From the American Heart Association. Circ Res 119:e39-75
Guarini, Giacinta; Kiyooka, Takahiko; Ohanyan, Vahagn et al. (2016) Impaired coronary metabolic dilation in the metabolic syndrome is linked to mitochondrial dysfunction and mitochondrial DNA damage. Basic Res Cardiol 111:29
DelloStritto, Daniel J; Connell, Patrick J; Dick, Gregory M et al. (2016) Differential regulation of TRPV1 channels by H2O2: implications for diabetic microvascular dysfunction. Basic Res Cardiol 111:21
Kang, Patrick T; Chen, Chwen-Lih; Ohanyan, Vahagn et al. (2015) Overexpressing superoxide dismutase 2 induces a supernormal cardiac function by enhancing redox-dependent mitochondrial function and metabolic dilation. J Mol Cell Cardiol 88:14-28
Kang, Patrick T; Chen, Chwen-Lih; Chen, Yeong-Renn (2015) Increased mitochondrial prooxidant activity mediates up-regulation of Complex I S-glutathionylation via protein thiyl radical in the murine heart of eNOS(-/-). Free Radic Biol Med 79:56-68
Kang, Patrick T; Chen, Chwen-Lih; Ren, Pei et al. (2014) BCNU-induced gR2 defect mediates S-glutathionylation of Complex I and respiratory uncoupling in myocardium. Biochem Pharmacol 89:490-502

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