Our studies in the past 20 years led to a better understanding of the molecular events contributing to cardiac injury by ischemia and reperfusion (I/R) and the role of protein kinase C (PKC) isozymes in this response. We showed that epsilon PKC activation protects from I/R-induced injury whereas activation of delta PKC increases this injury. Our work and recent discoveries by a number of other labs identified the importance of the mitochondria in the health of the myocardium. The mitochondria are critical for cardiac metabolism and energetics as well as for cell death through apoptosis and necrosis. Because we found a critical role for delta PKC-mediated mitochondrial regulation in I/R response, our current proposal is focused on elucidating the role of delta PKC in mitochondrial structure and functions following I/R and under basal conditions. Specifically, we plan Aim 1: Determine the role of delta PKC phosphorylation of the mitochondrial matrix enzyme, pyruvate dehydrogenase kinase, in inhibition of ATP regeneration Aim 2: Determine the role of delta PKC phosphorylation of dynamin-related protein 1 on mitochondrial fission Aim 3: Determine the role of delta PKC in elimination of damaged mitochondria Aim 4: Determine how delta PKC translocates onto the mitochondria, how delta PKC is imported into the mitochondrial matrix and whether I/R triggers activation of delta PKC that is different from hormone activation. Our hypothesis is that differen delta PKC substrates are critical at different stages of reperfusion injury. We previously showed that, when given right at reperfusion, a peptide inhibitor of all the phosphorylation events mediated by delta PKC that we have designed, reduced reperfusion injury by 50-70%, as measured in isolated cardiac myocytes, and in rat, mouse and pig models of myocardial infarction. However, what the role of each delta PKC substrate is in I/R and when its activity is critical is not known. Using a rational approach that we have developed, we will generate new separation-of-function inhibitors of delta PKC that will selectively inhibit phosphorylation of one substrate of delta PKC without affecting the phosphorylation of the others. These separation-of-function inhibitors of delta PKC will be used in isolated myocytes, in Langendorff preparations and in vivo, at reperfusion and during the first few weeks after MI to address the above aims. Focusing on the molecular events related to mitochondrial fate should elucidate fundamental mechanisms in cell biology, in general, and in the health of the myocardium, in particular. Further, this work will likely identify novel targets for therapeutic interventions for myocardial infarction patients.

Public Health Relevance

This work will elucidate how the cellular organelles that generate energy to the heart contribute to cardiac injury after heart attack. Some of the pharmacological reagents that we will prepare may be useful also as drug leads for patients with heart attacks.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Project (R01)
Project #
5R01HL052141-17
Application #
8617289
Study Section
Myocardial Ischemia and Metabolism Study Section (MIM)
Program Officer
Wong, Renee P
Project Start
1996-04-05
Project End
2017-01-31
Budget Start
2014-02-01
Budget End
2015-01-31
Support Year
17
Fiscal Year
2014
Total Cost
$771,400
Indirect Cost
$279,214
Name
Stanford University
Department
Biology
Type
Schools of Medicine
DUNS #
009214214
City
Stanford
State
CA
Country
United States
Zip Code
94305
Qvit, Nir; Mochly-Rosen, Daria (2014) The many hats of protein kinase C?: one enzyme with many functions. Biochem Soc Trans 42:1529-33
Mochly-Rosen, Daria; Disatnik, Marie-Helene; Qi, Xin (2014) The challenge in translating basic research discoveries to treatment of Huntington disease. Rare Dis 2:e28637
Guo, Xing; Disatnik, Marie-Helene; Monbureau, Marie et al. (2013) Inhibition of mitochondrial fragmentation diminishes Huntington's disease-associated neurodegeneration. J Clin Invest 123:5371-88
Monti, Martina; Donnini, Sandra; Morbidelli, Lucia et al. (2013) PKC? activation promotes FGF-2 exocytosis and induces endothelial cell proliferation and sprouting. J Mol Cell Cardiol 63:107-17
Disatnik, Marie-Helene; Ferreira, Julio C B; Campos, Juliane Cruz et al. (2013) Acute inhibition of excessive mitochondrial fission after myocardial infarction prevents long-term cardiac dysfunction. J Am Heart Assoc 2:e000461
Mann, Douglas L; Mochly-Rosen, Daria (2013) Translational medicine: mitigating risks for investigators. Nat Rev Drug Discov 12:327-8
Gross, Eric R; Hsu, Anna K; Urban, Travis J et al. (2013) Nociceptive-induced myocardial remote conditioning is mediated by neuronal gamma protein kinase C. Basic Res Cardiol 108:381
Palaniyandi, Suresh Selvaraj; Ferreira, Julio Cesar Batista; Brum, Patricia Chakur et al. (2011) PKC*II inhibition attenuates myocardial infarction induced heart failure and is associated with a reduction of fibrosis and pro-inflammatory responses. J Cell Mol Med 15:1769-77
Ferreira, Julio Cesar Batista; Brum, Patricia Chakur; Mochly-Rosen, Daria (2011) ?IIPKC and ?PKC isozymes as potential pharmacological targets in cardiac hypertrophy and heart failure. J Mol Cell Cardiol 51:479-84
Ding, Richard Qinxue; Tsao, Jerry; Chai, Hong et al. (2011) Therapeutic potential for protein kinase C inhibitor in vascular restenosis. J Cardiovasc Pharmacol Ther 16:160-7

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