In the hypertrophied or failing heart, signaling cascades that both induce and ameliorate maladaptive changes in cell and organ function are co-activated. Current clinical therapy largely aims at blocking pathological signaling, but efforts to enhance intrinsic adaptive pathways are also gaining interest. The cyclic GMP-protein kinase G1? (PKG1?) pathway is a prime example of the latter. Recent studies, many from my laboratory, have revealed how inhibiting phosphodiesterase type 5 to stimulate PKG blocks the progression and even reverses established heart disease. This has led to two major NIH- sponsored multicenter trials of PDE5 inhibitors in heart failure with either reduced or preserved ejection fraction. At the core of this translation is the functionality of PKG1? in the myocardium, and in new data we show for the first time that the enzyme is oxidized in diseased left ventricles, reducing its capacity to offset pathology. This involves a di-sulfide between cysteine-42 (C42) in each PKG1? monomer, a residue lying just within an N-terminus docking domain critical for protein interactions. Mice with a knock-in mutation (C42S) that precludes C42 oxidation show improved pathophysiology to sustained pressure-overload. However, they also show that PKG can no longer be activated by PDE5-inhibition. This indicates that therapies leveraging PKG activation, such as natriuretic peptides, nitric oxide donors, or PDE5-inhibitors, may themselves critically depend on PKG redox state. In this project, we determine the impact of PKG1? C42 oxidation/dimerization on the diseased heart, testing the hypothesis that redox modification alters its protein-interactome and thus kinase signaling, as well as activation by intracellular cGMP pools. This is accomplished in three Aims.
In aim 1, we determine how prevention of PKG1? C42-dimer impacts hearts subjected to pressure overload or infarction versus physiological (exercise) stress, identifying differences in kinase targeting and patho- physiological regulation. We also test if PKG1?-redox impacts the capacity of clinical methods to stimulate the kinase, and identify mechanisms for such changes.
In Aim 2, we assess how PKG1?- redox impacts kinase modification of myocyte sarcomere function, identifying changes in the myofibrillar enriched and depleted phospho-proteome.
In Aim 3, we examine the impact of PKG1?- redox on intracellular kinase localization and protein interactions. The interactome is identified, and mechanisms by which the C42-dimer impacts the protein docking-domain determined. Collectively, these studies will determine the role, mechanisms, and translational implications for PKG redox modulation, information central to optimizing therapies designed to leverage its signaling for the treatment of treat heart disease.

Public Health Relevance

Protein kinase G (PKG) acts as a molecular 'brake' in the heart, countering adverse effects of sustained abnormal stress, and trials testing drugs that stimulate it are ongoing. We now show that the kinase gets oxidized in heart disease changing how it works, and how the efficacy of drugs that stimulate it can be impacted. We will determine now PKG oxidation affects its function with the ultimate goal of improving our ability to leverage this enzyme for the treatment of heart disease.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Project (R01)
Project #
4R01HL119012-04
Application #
9063604
Study Section
Special Emphasis Panel (ZRG1)
Program Officer
Adhikari, Bishow B
Project Start
2013-09-01
Project End
2016-12-31
Budget Start
2016-06-01
Budget End
2016-12-31
Support Year
4
Fiscal Year
2016
Total Cost
Indirect Cost
Name
Johns Hopkins University
Department
Internal Medicine/Medicine
Type
Schools of Medicine
DUNS #
001910777
City
Baltimore
State
MD
Country
United States
Zip Code
21205
Chung, Heaseung Sophia; Murray, Christopher I; Van Eyk, Jennifer E (2018) A Proteomics Workflow for Dual Labeling Biotin Switch Assay to Detect and Quantify Protein S-Nitroylation. Methods Mol Biol 1747:89-101
Nakamura, Taishi; Zhu, Guangshuo; Ranek, Mark J et al. (2018) Prevention of PKG-1? Oxidation Suppresses Antihypertrophic/Antifibrotic Effects From PDE5 Inhibition but not sGC Stimulation. Circ Heart Fail 11:e004740
Hashimoto, Toru; Kim, Grace E; Tunin, Richard S et al. (2018) Acute Enhancement of Cardiac Function by Phosphodiesterase Type 1 Inhibition. Circulation 138:1974-1987
Chung, Heaseung Sophia; Kim, Grace E; Holewinski, Ronald J et al. (2017) Transient receptor potential channel 6 regulates abnormal cardiac S-nitrosylation in Duchenne muscular dystrophy. Proc Natl Acad Sci U S A 114:E10763-E10771
Cho, Gun-Sik; Lee, Dong I; Tampakakis, Emmanouil et al. (2017) Neonatal Transplantation Confers Maturation of PSC-Derived Cardiomyocytes Conducive to Modeling Cardiomyopathy. Cell Rep 18:571-582
Hsu, Steven; Kass, David A (2016) Can Nitrite AMPk Up Sirt-ainty to Treat Heart Failure With Preserved Ejection Fraction? Circulation 133:692-4
Kirk, Jonathan A; Holewinski, Ronald J; Crowgey, Erin L et al. (2016) Protein kinase G signaling in cardiac pathophysiology: Impact of proteomics on clinical trials. Proteomics 16:894-905
Hashimoto, Toru; Sivakumaran, Vidhya; Carnicer, Ricardo et al. (2016) Tetrahydrobiopterin Protects Against Hypertrophic Heart Disease Independent of Myocardial Nitric Oxide Synthase Coupling. J Am Heart Assoc 5:e003208
Bullen, John W; Tchernyshyov, Irina; Holewinski, Ronald J et al. (2016) Protein kinase A-dependent phosphorylation stimulates the transcriptional activity of hypoxia-inducible factor 1. Sci Signal 9:ra56
Prysyazhna, Oleksandra; Burgoyne, Joseph Robert; Scotcher, Jenna et al. (2016) Phosphodiesterase 5 Inhibition Limits Doxorubicin-induced Heart Failure by Attenuating Protein Kinase G I? Oxidation. J Biol Chem 291:17427-36

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