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Silnitsky S, Rubin SJS, Zerihun M, Qvit N. An Update on Protein Kinases as Therapeutic Targets-Part I: Protein Kinase C Activation and Its Role in Cancer and Cardiovascular Diseases. Int J Mol Sci 2023; 24:17600. [PMID: 38139428 PMCID: PMC10743896 DOI: 10.3390/ijms242417600] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2023] [Revised: 12/10/2023] [Accepted: 12/12/2023] [Indexed: 12/24/2023] Open
Abstract
Protein kinases are one of the most significant drug targets in the human proteome, historically harnessed for the treatment of cancer, cardiovascular disease, and a growing number of other conditions, including autoimmune and inflammatory processes. Since the approval of the first kinase inhibitors in the late 1990s and early 2000s, the field has grown exponentially, comprising 98 approved therapeutics to date, 37 of which were approved between 2016 and 2021. While many of these small-molecule protein kinase inhibitors that interact orthosterically with the protein kinase ATP binding pocket have been massively successful for oncological indications, their poor selectively for protein kinase isozymes have limited them due to toxicities in their application to other disease spaces. Thus, recent attention has turned to the use of alternative allosteric binding mechanisms and improved drug platforms such as modified peptides to design protein kinase modulators with enhanced selectivity and other pharmacological properties. Herein we review the role of different protein kinase C (PKC) isoforms in cancer and cardiovascular disease, with particular attention to PKC-family inhibitors. We discuss translational examples and carefully consider the advantages and limitations of each compound (Part I). We also discuss the recent advances in the field of protein kinase modulators, leverage molecular docking to model inhibitor-kinase interactions, and propose mechanisms of action that will aid in the design of next-generation protein kinase modulators (Part II).
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Affiliation(s)
- Shmuel Silnitsky
- The Azrieli Faculty of Medicine in the Galilee, Bar-Ilan University, Henrietta Szold St. 8, Safed 1311502, Israel; (S.S.); (M.Z.)
| | - Samuel J. S. Rubin
- Department of Medicine, School of Medicine, Stanford University, 300 Pasteur Drive, Stanford, CA 94305, USA;
| | - Mulate Zerihun
- The Azrieli Faculty of Medicine in the Galilee, Bar-Ilan University, Henrietta Szold St. 8, Safed 1311502, Israel; (S.S.); (M.Z.)
| | - Nir Qvit
- The Azrieli Faculty of Medicine in the Galilee, Bar-Ilan University, Henrietta Szold St. 8, Safed 1311502, Israel; (S.S.); (M.Z.)
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Multiomics Approach Reveals an Important Role of BNIP3 in Myocardial Remodeling and the Pathogenesis of Heart Failure with Reduced Ejection Fraction. Cells 2022; 11:cells11091572. [PMID: 35563877 PMCID: PMC9105187 DOI: 10.3390/cells11091572] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2022] [Revised: 05/03/2022] [Accepted: 05/03/2022] [Indexed: 11/16/2022] Open
Abstract
Previous work showed a role of BNIP3 in myocardial remodeling and progression to HFrEF. We utilized a multiomics approach to unravel BNIP3-related molecular mechanisms in the pathogenesis of HFrEF. BNIP3 knockdown in HFrEF improved glycolysis, pyruvate metabolism, branched-chain amino acid catabolism, and oxidative phosphorylation, and restored endoplasmic reticulum (ER)–mitochondrial (mt) calcium and ion homeostasis. These effects of BNIP3 on cardiac metabolism were related to its interaction and downregulation, and/or phosphorylation, of specific mt-proteins involved in the aforementioned metabolic pathways, including the MICOS and SLC25A families of carrier proteins. BNIP3 affected ER–mt-calcium and ion homeostasis via its interaction-induced VDAC1 dimerization and modulation of VDAC1 phosphorylation at Ser104 and Ser241, and the downregulation of LETM1. At the ER level, BNIP3 interacted with the enzyme SERCA2a and the PKA signaling complex, leading to the downregulation of SERCA2a and PKA-mediated Ser16 phospholamban phosphorylation. Additionally, BNIP3 attenuated AMPK and PRKCE activity by modulating AMPK phosphorylation at Ser485/491 and Ser377 residues, and PRKCE phosphorylation at Thr521 and Thr710 residues. BNIP3 also interacted with sarcomeric, cytoskeletal, and cellular transcription and translation proteins, and affected their expression and/or phosphorylation. In conclusion, BNIP3 modulates multiple pathobiological processes and constitutes an attractive therapeutic target in HFrEF.
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Ciocci Pardo A, González Arbeláez LF, Fantinelli JC, Álvarez BV, Mosca SM, Swenson ER. Myocardial and mitochondrial effects of the anhydrase carbonic inhibitor ethoxzolamide in ischemia-reperfusion. Physiol Rep 2021; 9:e15093. [PMID: 34806317 PMCID: PMC8606860 DOI: 10.14814/phy2.15093] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Revised: 09/21/2021] [Accepted: 09/21/2021] [Indexed: 11/24/2022] Open
Abstract
We have previously demonstrated that inhibition of extracellularly oriented carbonic anhydrase (CA) isoforms protects the myocardium against ischemia-reperfusion injury. In this study, our aim was to assess the possible further contribution of CA intracellular isoforms examining the actions of the highly diffusible cell membrane permeant inhibitor of CA, ethoxzolamide (ETZ). Isolated rat hearts, after 20 min of stabilization, were assigned to the following groups: (1) Nonischemic control: 90 min of perfusion; (2) Ischemic control: 30 min of global ischemia and 60 min of reperfusion (R); and (3) ETZ: ETZ at a concentration of 100 μM was administered for 10 min before the onset of ischemia and then during the first 10 min of reperfusion. In additional groups, ETZ was administered in the presence of SB202190 (SB, a p38MAPK inhibitor) or chelerythrine (Chel, a protein kinase C [PKC] inhibitor). Infarct size, myocardial function, and the expression of phosphorylated forms of p38MAPK, PKCε, HSP27, and Drp1, and calcineurin Aβ content were assessed. In isolated mitochondria, the Ca2+ response, Ca2+ retention capacity, and membrane potential were measured. ETZ decreased infarct size by 60%, improved postischemic recovery of myocardial contractile and diastolic relaxation increased P-p38MAPK, P-PKCε, P-HSP27, and P-Drp1 expression, decreased calcineurin content, and normalized calcium and membrane potential parameters measured in isolated mitochondria. These effects were significantly attenuated when ETZ was administered in the presence of SB or Chel. These data show that ETZ protects the myocardium and mitochondria against ischemia-reperfusion injury through p38MAPK- and PKCε-dependent pathways and reinforces the role of CA as a possible target in the management of acute cardiac ischemic diseases.
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Affiliation(s)
- Alejandro Ciocci Pardo
- Centro de Investigaciones Cardiovasculares ¨Dr Horacio E Cingolani¨CCT‐CONICETFacultad de Ciencias MédicasUniversidad Nacional de La PlataLa PlataBuenos AiresArgentina
| | - Luisa F. González Arbeláez
- Centro de Investigaciones Cardiovasculares ¨Dr Horacio E Cingolani¨CCT‐CONICETFacultad de Ciencias MédicasUniversidad Nacional de La PlataLa PlataBuenos AiresArgentina
| | - Juliana C. Fantinelli
- Centro de Investigaciones Cardiovasculares ¨Dr Horacio E Cingolani¨CCT‐CONICETFacultad de Ciencias MédicasUniversidad Nacional de La PlataLa PlataBuenos AiresArgentina
| | - Bernardo V. Álvarez
- Centro de Investigaciones Cardiovasculares ¨Dr Horacio E Cingolani¨CCT‐CONICETFacultad de Ciencias MédicasUniversidad Nacional de La PlataLa PlataBuenos AiresArgentina
- Present address:
Department of BiochemistryMembrane Protein Disease Research GroupUniversity of AlbertaEdmontonAlbertaT6G 2H7Canada
| | - Susana M. Mosca
- Centro de Investigaciones Cardiovasculares ¨Dr Horacio E Cingolani¨CCT‐CONICETFacultad de Ciencias MédicasUniversidad Nacional de La PlataLa PlataBuenos AiresArgentina
| | - Erik R. Swenson
- Department of Medicine, Pulmonary and Critical Care MedicineVA Puget Sound Health Care SystemUniversity of WashingtonSeattleWashingtonUSA
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Chaanine AH. Metabolic Remodeling and Implicated Calcium and Signal Transduction Pathways in the Pathogenesis of Heart Failure. Int J Mol Sci 2021; 22:ijms221910579. [PMID: 34638917 PMCID: PMC8508915 DOI: 10.3390/ijms221910579] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Revised: 09/20/2021] [Accepted: 09/27/2021] [Indexed: 11/16/2022] Open
Abstract
The heart is an organ with high-energy demands in which the mitochondria are most abundant. They are considered the powerhouse of the cell and occupy a central role in cellular metabolism. The intermyofibrillar mitochondria constitute the majority of the three-mitochondrial subpopulations in the heart. They are also considered to be the most important in terms of their ability to participate in calcium and cellular signaling, which are critical for the regulation of mitochondrial function and adenosine triphosphate (ATP) production. This is because they are located in very close proximity with the endoplasmic reticulum (ER), and for the presence of tethering complexes enabling interorganelle crosstalk via calcium signaling. Calcium is an important second messenger that regulates mitochondrial function. It promotes ATP production and cellular survival under physiological changes in cardiac energetic demand. This is accomplished in concert with signaling pathways that regulate both calcium cycling and mitochondrial function. Perturbations in mitochondrial homeostasis and metabolic remodeling occupy a central role in the pathogenesis of heart failure. In this review we will discuss perturbations in ER-mitochondrial crosstalk and touch on important signaling pathways and molecular mechanisms involved in the dysregulation of calcium homeostasis and mitochondrial function in heart failure.
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Affiliation(s)
- Antoine H. Chaanine
- Department of Medicine, Heart and Vascular Institute, Tulane University, New Orleans, LA 70112, USA; ; Tel.: +1-(504)-988-1612
- Department of Physiology, Tulane University, New Orleans, LA 70112, USA
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Salama A, Mansour D, Hegazy R. The cardio and renoprotective role of ginseng against epinephrine-induced myocardial infarction in rats: Involvement of angiotensin II type 1 receptor/protein kinase C. Toxicol Rep 2021; 8:908-919. [PMID: 33996504 PMCID: PMC8099916 DOI: 10.1016/j.toxrep.2021.04.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2020] [Revised: 02/26/2021] [Accepted: 04/16/2021] [Indexed: 11/30/2022] Open
Abstract
Epinephrine induced MI with renal complication through Nrf2/NF-κB imbalance and PKC/AT1R. Ginseng abolished ECG changes induced by epinephrine and stimulated Nrf2. Ginseng reduced upregulation of PKC, NF-κB, and AT1R induced by epinephrine. Ginseng inhibited iNOS and corrected renal disorder in epinephrine model of MI.
The expression of angiotensin II type 1 receptor (AT1 receptor)/protein kinase C (PKC) in heart tissues has a vital role in myocardial infarction (MI). The current work aimed to clarify the renal complication enhanced by MI following epinephrine injection via AT1 receptor/ PKC expression; in addition, the impact of ginseng extract on epinephrine-induced MI and its renal complication was assessed. Adult male albino Wistar rats were pretreated orally with ginseng extract (200 & 400 mg/kg/day) for 14 days, then two successive doses of epinephrine injection (100 mg/kg, i.p.). Epinephrine evoked electrocardiographic (ECG) and renal changes accompanied with a significant increase in heart and kidney contents of malodialdehyde (MDA), nitric oxide (NO), protein kinase C (PKC), heart contents of nuclear factor-kabba B (NF-κB) and angiotensin 1receptor (AT1R), as well as a decrease in heart and kidney reduced glutathione (GSH) and nuclear factor-erythroid-related factor 2 (Nrf2) contents. In histopathological investigations epinephrine exhibited deleterious heart changes in the form of acute MI with the presence of necrosis of cardiomyocytes with iNOS expression and produced glomerulus and renal tubules degeneration. Pretreatment of rats with ginseng extract in both doses significantly corrected epinephrine-induced heart and renal changes. The current work revealed that epinephrine-induced MI associated with aggravated renal complication and ginseng extract has cardio and reno protective role against this as it reduces infarct size, preserves cardiac and renal tissues and functions through activating Nrf2 and down-regulating NF-κB, PKC, AT1R and iNOS.
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Affiliation(s)
- Abeer Salama
- Pharmacology Department, Medical Division, National Research Centre, 33 El Bohouth St. (Former El-Tahrir St.), 12622 Dokki, Cairo, Egypt
| | - Dina Mansour
- Pharmacology Department, Medical Division, National Research Centre, 33 El Bohouth St. (Former El-Tahrir St.), 12622 Dokki, Cairo, Egypt
| | - Rehab Hegazy
- Pharmacology Department, Medical Division, National Research Centre, 33 El Bohouth St. (Former El-Tahrir St.), 12622 Dokki, Cairo, Egypt
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Korbecki J, Bajdak-Rusinek K. The effect of palmitic acid on inflammatory response in macrophages: an overview of molecular mechanisms. Inflamm Res 2019; 68:915-932. [PMID: 31363792 PMCID: PMC6813288 DOI: 10.1007/s00011-019-01273-5] [Citation(s) in RCA: 258] [Impact Index Per Article: 51.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2019] [Revised: 07/22/2019] [Accepted: 07/23/2019] [Indexed: 02/06/2023] Open
Abstract
Palmitic acid is a saturated fatty acid whose blood concentration is elevated in obese patients. This causes inflammatory responses, where toll-like receptors (TLR), TLR2 and TLR4, play an important role. Nevertheless, palmitic acid is not only a TLR agonist. In the cell, this fatty acid is converted into phospholipids, diacylglycerol and ceramides. They trigger the activation of various signaling pathways that are common for LPS-mediated TLR4 activation. In particular, metabolic products of palmitic acid affect the activation of various PKCs, ER stress and cause an increase in ROS generation. Thanks to this, palmitic acid also strengthens the TLR4-induced signaling. In this review, we discuss the mechanisms of inflammatory response induced by palmitic acid. In particular, we focus on describing its effect on ER stress and IRE1α, and the mechanisms of NF-κB activation. We also present the mechanisms of inflammasome NLRP3 activation and the effect of palmitic acid on enhanced inflammatory response by increasing the expression of FABP4/aP2. Finally, we focus on the consequences of inflammatory responses, in particular, the effect of TNF-α, IL-1β and IL-6 on insulin resistance. Due to the high importance of macrophages and the production of proinflammatory cytokines by them, this work mainly focuses on these cells.
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Affiliation(s)
- Jan Korbecki
- Department of Molecular Biology, School of Medicine in Katowice, Medical University of Silesia, Medyków 18 St., 40-752, Katowice, Poland.
| | - Karolina Bajdak-Rusinek
- Department of Medical Genetics, School of Medicine in Katowice, Medical University of Silesia, Medyków 18 St., 40-752, Katowice, Poland
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Cheung JY, Merali S, Wang J, Zhang XQ, Song J, Merali C, Tomar D, You H, Judenherc-Haouzi A, Haouzi P. The central role of protein kinase C epsilon in cyanide cardiotoxicity and its treatment. Toxicol Sci 2019; 171:247-257. [PMID: 31173149 PMCID: PMC6735853 DOI: 10.1093/toxsci/kfz137] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2019] [Revised: 05/28/2019] [Accepted: 05/28/2019] [Indexed: 01/02/2023] Open
Abstract
In adult mouse myocytes, brief exposure to sodium cyanide (CN) in the presence of glucose does not decrease ATP levels, yet produces profound reduction in contractility, intracellular Ca2+ concentration ([Ca2+]i) transient and L-type Ca2+ current (ICa) amplitudes. We analyzed proteomes from myocytes exposed to CN, focusing on ionic currents associated with excitation-contraction coupling. CN induced phosphorylation of α1c subunit of L-type Ca2+ channel and α2 subunit of Na+-K+-ATPase. Methylene blue (MB), a CN antidote that we previously reported to ameliorate CN-induced reduction in contraction, [Ca2+]i transient and ICa amplitudes, was able to reverse this phosphorylation. CN decreased Na+-K+-ATPase current contributed by α2 but not α1 subunit, an effect that was also counteracted by MB. Peptide consensus sequences suggested CN-induced phosphorylation was mediated by protein kinase C epsilon (PKCε). Indeed, CN stimulated PKC kinase activity and induced PKCε membrane translocation, effects that were prevented by MB. Pre-treatment with myristoylated PKCε translocation activator or inhibitor peptides mimicked and inhibited the effects of CN on ICa and myocyte contraction, respectively. We conclude that CN activates PKCε, which phosphorylates L-type Ca2+ channel and Na+-K+-ATPase, resulting in depressed cardiac contractility. We hypothesize that this inhibition of ion fluxes represents a novel mechanism by which the cardiomyocyte reduces its ATP demand (decreased ion fluxes and contractility), diminishes ATP turnover and preserves cell viability. However, this cellular protective effect translates into life-threatening cardiogenic shock in vivo, thereby creating a profound disconnect between survival mechanisms at the cardiomyocyte level from those at the level of the whole organism.
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Affiliation(s)
- Joseph Y Cheung
- Center for Translational Medicine and Lewis Katz School of Medicine of Temple University, Philadelphia, PA.,Department of Medicine, Lewis Katz School of Medicine of Temple University, Philadelphia, PA
| | - Salim Merali
- Moulder Center for Drug Discovery Research, Temple University School of Pharmacy, Philadelphia, PA
| | - JuFang Wang
- Center for Translational Medicine and Lewis Katz School of Medicine of Temple University, Philadelphia, PA
| | - Xue-Qian Zhang
- Center for Translational Medicine and Lewis Katz School of Medicine of Temple University, Philadelphia, PA
| | - Jianliang Song
- Center for Translational Medicine and Lewis Katz School of Medicine of Temple University, Philadelphia, PA
| | - Carmen Merali
- Moulder Center for Drug Discovery Research, Temple University School of Pharmacy, Philadelphia, PA
| | - Dhanendra Tomar
- Center for Translational Medicine and Lewis Katz School of Medicine of Temple University, Philadelphia, PA
| | - Hanning You
- Department of Medicine, Lewis Katz School of Medicine of Temple University, Philadelphia, PA
| | | | - Philippe Haouzi
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Pennsylvania State University College of Medicine, Hershey, PA
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Abstract
Heart failure (HF) is a physiological state in which cardiac output is insufficient to meet the needs of the body. It is a clinical syndrome characterized by impaired ability of the left ventricle to either fill or eject blood efficiently. HF is a disease of multiple aetiologies leading to progressive cardiac dysfunction and it is the leading cause of deaths in both developed and developing countries. HF is responsible for about 73,000 deaths in the UK each year. In the USA, HF affects 5.8 million people and 550,000 new cases are diagnosed annually. Cardiac remodelling (CD), which plays an important role in pathogenesis of HF, is viewed as stress response to an index event such as myocardial ischaemia or imposition of mechanical load leading to a series of structural and functional changes in the viable myocardium. Protein kinase C (PKC) isozymes are a family of serine/threonine kinases. PKC is a central enzyme in the regulation of growth, hypertrophy, and mediators of signal transduction pathways. In response to circulating hormones, activation of PKC triggers a multitude of intracellular events influencing multiple physiological processes in the heart, including heart rate, contraction, and relaxation. Recent research implicates PKC activation in the pathophysiology of a number of cardiovascular disease states. Few reports are available that examine PKC in normal and diseased human hearts. This review describes the structure, functions, and distribution of PKCs in the healthy and diseased heart with emphasis on the human heart and, also importantly, their regulation in heart failure.
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Affiliation(s)
- Raphael M Singh
- School of Forensic and Applied Sciences, University of Central Lancashire, Preston, England, PR1 2HE, UK.
- Faculty of Medicine and Health Sciences, University of Guyana, Turkeyen, Georgetown, Guyana.
| | - Emanuel Cummings
- Faculty of Medicine and Health Sciences, University of Guyana, Turkeyen, Georgetown, Guyana
| | - Constantinos Pantos
- Department of Pharmacology, School of Medicine, University of Athens, Athens, Greece
| | - Jaipaul Singh
- School of Forensic and Applied Sciences, University of Central Lancashire, Preston, England, PR1 2HE, UK
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Scruggs SB, Wang D, Ping P. PRKCE gene encoding protein kinase C-epsilon-Dual roles at sarcomeres and mitochondria in cardiomyocytes. Gene 2016; 590:90-6. [PMID: 27312950 DOI: 10.1016/j.gene.2016.06.016] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2016] [Revised: 05/23/2016] [Accepted: 06/05/2016] [Indexed: 12/26/2022]
Abstract
Protein kinase C-epsilon (PKCε) is an isoform of a large PKC family of enzymes that has a variety of functions in different cell types. Here we discuss two major roles of PKCε in cardiac muscle cells; specifically, its role in regulating cardiac muscle contraction via targeting the sarcomeric proteins, as well as modulating cardiac cell energy production and metabolism by targeting cardiac mitochondria. The importance of PKCε action is described within the context of intracellular localization, as substrate selectivity and specificity is achieved through spatiotemporal targeting of PKCε. Accordingly, the role of PKCε in regulating myocardial function in physiological and pathological states has been documented in both cardioprotection and cardiac hypertrophy.
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Affiliation(s)
- Sarah B Scruggs
- Departments of Physiology, Medicine (Cardiology) and Bioinformatics, NIH BD2K Center of Excellence for Biomedical Computing, University of California Los Angeles, Los Angeles, CA 90095, USA.
| | - Ding Wang
- Departments of Physiology, Medicine (Cardiology) and Bioinformatics, NIH BD2K Center of Excellence for Biomedical Computing, University of California Los Angeles, Los Angeles, CA 90095, USA
| | - Peipei Ping
- Departments of Physiology, Medicine (Cardiology) and Bioinformatics, NIH BD2K Center of Excellence for Biomedical Computing, University of California Los Angeles, Los Angeles, CA 90095, USA.
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Lin YH, Warren CM, Li J, McKinsey TA, Russell B. Myofibril growth during cardiac hypertrophy is regulated through dual phosphorylation and acetylation of the actin capping protein CapZ. Cell Signal 2016; 28:1015-24. [PMID: 27185186 DOI: 10.1016/j.cellsig.2016.05.011] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2016] [Revised: 05/11/2016] [Accepted: 05/12/2016] [Indexed: 01/08/2023]
Abstract
The mechanotransduction signaling pathways initiated in heart muscle by increased mechanical loading are known to lead to long-term transcriptional changes and hypertrophy, but the rapid events for adaptation at the sarcomeric level are not fully understood. The goal of this study was to test the hypothesis that actin filament assembly during cardiomyocyte growth is regulated by post-translational modifications (PTMs) of CapZβ1. In rapidly hypertrophying neonatal rat ventricular myocytes (NRVMs) stimulated by phenylephrine (PE), two-dimensional gel electrophoresis (2DGE) of CapZβ1 revealed a shift toward more negative charge. Consistent with this, mass spectrometry identified CapZβ1 phosphorylation on serine-204 and acetylation on lysine-199, two residues which are near the actin binding surface of CapZβ1. Ectopic expression of dominant negative PKCɛ (dnPKCɛ) in NRVMs blunted the PE-induced increase in CapZ dynamics, as evidenced by the kinetic constant (Kfrap) of fluorescence recovery after photobleaching (FRAP), and concomitantly reduced phosphorylation and acetylation of CapZβ1. Furthermore, inhibition of class I histone deacetylases (HDACs) increased lysine-199 acetylation on CapZβ1, which increased Kfrap of CapZ and stimulated actin dynamics. Finally, we show that PE treatment of NRVMs results in decreased binding of HDAC3 to myofibrils, suggesting a signal-dependent mechanism for the regulation of sarcomere-associated CapZβ1 acetylation. Taken together, this dual regulation through phosphorylation and acetylation of CapZβ1 provides a novel model for the regulation of myofibril growth during cardiac hypertrophy.
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Affiliation(s)
- Ying-Hsi Lin
- Department of Physiology and Biophysics, University of Illinois at Chicago, College of Medicine, Chicago, IL 60612-7342, United States; Department of Physiology & Biophysics, Center for Cardiovascular Research, University of Illinois at Chicago, Chicago, IL 60612-7342, United States
| | - Chad M Warren
- Department of Physiology and Biophysics, University of Illinois at Chicago, College of Medicine, Chicago, IL 60612-7342, United States; Department of Physiology & Biophysics, Center for Cardiovascular Research, University of Illinois at Chicago, Chicago, IL 60612-7342, United States
| | - Jieli Li
- Department of Physiology and Biophysics, University of Illinois at Chicago, College of Medicine, Chicago, IL 60612-7342, United States; Department of Physiology & Biophysics, Center for Cardiovascular Research, University of Illinois at Chicago, Chicago, IL 60612-7342, United States
| | - Timothy A McKinsey
- Department of Medicine, Division of Cardiology and Center for Fibrosis Research and Translation, University of Colorado Anschutz Medical Campus, Aurora, CO 80045-0508, United States
| | - Brenda Russell
- Department of Physiology and Biophysics, University of Illinois at Chicago, College of Medicine, Chicago, IL 60612-7342, United States; Department of Physiology & Biophysics, Center for Cardiovascular Research, University of Illinois at Chicago, Chicago, IL 60612-7342, United States.
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11
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Hou S, Shen PP, Zhao MM, Liu XP, Xie HY, Deng F, Feng JC. Mechanism of Mitochondrial Connexin43's Protection of the Neurovascular Unit under Acute Cerebral Ischemia-Reperfusion Injury. Int J Mol Sci 2016; 17:ijms17050679. [PMID: 27164087 PMCID: PMC4881505 DOI: 10.3390/ijms17050679] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2016] [Revised: 04/27/2016] [Accepted: 04/29/2016] [Indexed: 02/08/2023] Open
Abstract
We observed mitochondrial connexin43 (mtCx43) expression under cerebral ischemia-reperfusion (I/R) injury, analyzed its regulation, and explored its protective mechanisms. Wistar rats were divided into groups based on injections received before middle cerebral artery occlusion (MCAO). Cerebral infarction volume was detected by 2,3,5-triphenyltetrazolim chloride staining, and cell apoptosis was observed by transferase dUTP nick end labeling. We used transmission electron microscopy to observe mitochondrial morphology and determined superoxide dismutase (SOD) activity and malondialdehyde (MDA) content. MtCx43, p-mtCx43, protein kinase C (PKC), and p-PKC expression were detected by Western blot. Compared with those in the IR group, cerebral infarction volumes in the carbenoxolone (CBX) and diazoxide (DZX) groups were obviously smaller, and the apoptosis indices were down-regulated. Mitochondrial morphology was damaged after I/R, especially in the IR and 5-hydroxydecanoic acid (5-HD) groups. Similarly, decreased SOD activity and increased MDA were observed after MCAO; CBX, DZX, and phorbol-12-myristate-13-acetate (PMA) reduced mitochondrial functional injury. Expression of mtCx43 and p-mtCx43 and the p-Cx43/Cx43 ratio were significantly lower in the IR group than in the sham group. These abnormalities were ameliorated by CBX, DZX, and PMA. MtCx43 may protect the neurovascular unit from acute cerebral IR injury via PKC activation induced by mitoKATP channel agonists.
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Affiliation(s)
- Shuai Hou
- Department of Neurology and Neuroscience center, the First Hospital of Jilin University, Changchun 130021, China.
| | - Ping-Ping Shen
- Department of Neurology and Neuroscience center, the First Hospital of Jilin University, Changchun 130021, China.
| | - Ming-Ming Zhao
- Department of Neurology and Neuroscience center, the First Hospital of Jilin University, Changchun 130021, China.
| | - Xiu-Ping Liu
- Department of Neurology and Neuroscience center, the First Hospital of Jilin University, Changchun 130021, China.
| | - Hong-Yan Xie
- Department of Neurology and Neuroscience center, the First Hospital of Jilin University, Changchun 130021, China.
| | - Fang Deng
- Department of Neurology and Neuroscience center, the First Hospital of Jilin University, Changchun 130021, China.
| | - Jia-Chun Feng
- Department of Neurology and Neuroscience center, the First Hospital of Jilin University, Changchun 130021, China.
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12
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Role of the endothelin system in sexual dimorphism in cardiovascular and renal diseases. Life Sci 2016; 159:20-29. [PMID: 26939577 DOI: 10.1016/j.lfs.2016.02.093] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2015] [Revised: 02/05/2016] [Accepted: 02/26/2016] [Indexed: 02/08/2023]
Abstract
Epidemiological studies of blood pressure in men and women and in experimental animal models point to substantial sex differences in the occurrence of arterial hypertension as well as in the various manifestations of arterial hypertension, including myocardial infarction, stroke, retinopathy, chronic kidney failure, as well as hypertension-associated diseases (e.g. diabetes mellitus). Increasing evidence demonstrates that the endothelin (ET) system is a major player in the genesis of sex differences in cardiovascular and renal physiology and diseases. Sex differences in the ET system have been described in the vasculature, heart and kidney of humans and experimental animals. In the current review, we briefly describe the role of the ET system in the cardiovascular and renal systems. We also update information on sex differences at different levels of the ET system including synthesis, circulating and tissue levels, receptors, signaling pathways, ET actions, and responses to antagonists in different organs that contribute to blood pressure regulation. Knowledge of the mechanisms underlying sex differences in arterial hypertension can impact therapeutic strategies. Sex-targeted and/or sex-tailored approaches may improve treatment of cardiovascular and renal diseases.
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Li Y, Du X. Effects of α1-adrenoceptor agonist phenylephrine on swelling-activated chloride currents in human atrial myocytes. J Membr Biol 2014; 248:7-18. [PMID: 25155614 DOI: 10.1007/s00232-014-9723-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2014] [Accepted: 08/14/2014] [Indexed: 10/24/2022]
Abstract
Swelling-activated chloride currents (ICl.swell) play an important role in cardiac electrophysiology and arrhythmogenesis. However, the regulation of these currents has not been clarified to date. In this research, we focused on the function of phenylephrine, an α1-adrenoceptor agonist, in the regulation of I(Cl.swell) in human atrial myocytes. We recorded I(Cl.swell) evoked by a hypotonic bath solution with the whole-cell patch-clamp technique. We found that I(Cl.swell) increased over time, and it was difficult to achieve absolute steady state. Phenylephrine potentiated I(Cl.swell) from -1.00 ± 0.51 pA/pF at -90 mV and 2.58 ± 1.17 pA/pF at +40 mV to -1.46 ± 0.70 and 3.84 ± 1.67 pA/pF, respectively (P < 0.05, n = 6), and the upward trend in ICl.swell was slowed after washout. This effect was concentration-dependent, and the α1-adrenoceptor antagonist prazosin shifted the dose-effect curve rightward. Addition of prazosin or the protein kinase C (PKC) inhibitor bisindolylmaleimide (BIM) attenuated the effect of phenylephrine. The PKC activator phorbol 12,13-dibutyrate (PDBu) activated I(Cl.swell) from -1.69 ± 1.67 pA/pF at -90 mV and 5.58 ± 6.36 pA/pF at +40 mV to -2.41 ± 1.95 pA/pF and 7.05 ± 6.99 pA/pF, respectively (P < 0.01 at -90 mV and P < 0.05 at +40 mV; n = 6). In conclusion, the α1-adrenoceptor agonist phenylephrine augmented I(Cl.swell), a result that differs from previous reports in other animal species. The effect was attenuated by BIM and mimicked by PDBu, which indicates that phenylephrine might modulate I(Cl,swell) in a PKC-dependent manner.
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Affiliation(s)
- Yetao Li
- Department of Cardiovascular Surgery, People's Hospital of Guizhou Province, Guiyang, 550002, China
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14
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Sag CM, Wagner S, Maier LS. Role of oxidants on calcium and sodium movement in healthy and diseased cardiac myocytes. Free Radic Biol Med 2013; 63:338-49. [PMID: 23732518 DOI: 10.1016/j.freeradbiomed.2013.05.035] [Citation(s) in RCA: 83] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/31/2013] [Revised: 05/23/2013] [Accepted: 05/24/2013] [Indexed: 12/19/2022]
Abstract
In this review article we give an overview of current knowledge with respect to redox-sensitive alterations in Na(+) and Ca(2+) handling in the heart. In particular, we focus on redox-activated protein kinases including cAMP-dependent protein kinase A (PKA), protein kinase C (PKC), and Ca/calmodulin-dependent protein kinase II (CaMKII), as well as on redox-regulated downstream targets such as Na(+) and Ca(2+) transporters and channels. We highlight the pathological and physiological relevance of reactive oxygen species and some of its sources (such as NADPH oxidases, NOXes) for excitation-contraction coupling (ECC). A short outlook with respect to the clinical relevance of redox-dependent Na(+) and Ca(2+) imbalance will be given.
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Affiliation(s)
- Can M Sag
- Cardiovascular Division, The James Black Centre, King's College London, UK
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15
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Posttranslational modifications of cardiac troponin T: An overview. J Mol Cell Cardiol 2013; 63:47-56. [DOI: 10.1016/j.yjmcc.2013.07.004] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/21/2013] [Revised: 06/18/2013] [Accepted: 07/08/2013] [Indexed: 12/22/2022]
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16
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Tsai KL, Liang HJ, Yang ZD, Lue SI, Yang SL, Hsu C. Early inactivation of PKCε associates with late mitochondrial translocation of Bad and apoptosis in ventricle of septic rat. J Surg Res 2013; 186:278-86. [PMID: 24011917 DOI: 10.1016/j.jss.2013.08.010] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2013] [Revised: 07/30/2013] [Accepted: 08/08/2013] [Indexed: 01/03/2023]
Abstract
BACKGROUND Sepsis is usually accompanied by cardiomyocyte apoptosis and myocardial depression. Protein kinase C (PKC) has been reported to be important in regulating cardiac function and apoptosis; however, which PKC isoform is involved in sepsis-induced myocardial apoptosis remains unknown. MATERIALS AND METHODS A rat model of sepsis by cecal ligation and puncture was used. Early and late sepsis refers to those rats sacrificed at 9 and 18 h after cecal ligation and puncture, respectively. Ventricular septum (Sep), left ventricle (LV), and right ventricle were fractionated into membrane, mitochondrial, and cytosolic fractions, individually. The protein levels of PKC isoforms (-α, -β, -δ, -ε, -ζ, -ι, -λ, and -μ) and mitochondrial translocation of Bad were quantified by Western blot analysis. Apoptosis was detected by terminal deoxynucleotidyl transferase-mediated dUTP in situ nick-end labeling. The morphology of mitochondria was examined by electron microscopy. RESULTS The membrane/cytosol ratio of PKCε was predominantly higher in the Sep, LV, and right ventricle under physiological conditions. At early sepsis, the membrane/cytosol ratio of PKCε was significantly decreased in Sep and LV. At late sepsis, cardiomyocyte apoptosis associated with severe mitochondrial swelling and crista derangement were observed in Sep and LV at late sepsis. Additionally, mitochondria/cytosol ratio of Bad was significantly increased in Sep and LV. CONCLUSIONS The early inactivation of PKCε in the ventricle may affect the mitochondrial translocation of Bad and subsequent mitochondrial disruption and apoptosis at late sepsis. This finding opens up the prospect for a potential therapeutic strategy targeting PKCε activation to prevent myocardial depression in septic patients.
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Affiliation(s)
- Ke-Li Tsai
- Department of Physiology, School of Medicine, Faculty of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
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Drawnel FM, Archer CR, Roderick HL. The role of the paracrine/autocrine mediator endothelin-1 in regulation of cardiac contractility and growth. Br J Pharmacol 2013; 168:296-317. [PMID: 22946456 DOI: 10.1111/j.1476-5381.2012.02195.x] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2012] [Revised: 08/23/2012] [Accepted: 08/28/2012] [Indexed: 12/20/2022] Open
Abstract
UNLABELLED Endothelin-1 (ET-1) is a critical autocrine and paracrine regulator of cardiac physiology and pathology. Produced locally within the myocardium in response to diverse mechanical and neurohormonal stimuli, ET-1 acutely modulates cardiac contractility. During pathological cardiovascular conditions such as ischaemia, left ventricular hypertrophy and heart failure, myocyte expression and activity of the entire ET-1 system is enhanced, allowing the peptide to both initiate and maintain maladaptive cellular responses. Both the acute and chronic effects of ET-1 are dependent on the activation of intracellular signalling pathways, regulated by the inositol-trisphosphate and diacylglycerol produced upon activation of the ET(A) receptor. Subsequent stimulation of protein kinases C and D, calmodulin-dependent kinase II, calcineurin and MAPKs modifies the systolic calcium transient, myofibril function and the activity of transcription factors that coordinate cellular remodelling. The precise nature of the cellular response to ET-1 is governed by the timing, localization and context of such signals, allowing the peptide to regulate both cardiomyocyte physiology and instigate disease. LINKED ARTICLES This article is part of a themed section on Endothelin. To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2013.168.issue-1.
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Affiliation(s)
- Faye M Drawnel
- Babraham Research Campus, Babraham Institute, Cambridge, UK
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MicroRNA-25-dependent up-regulation of NADPH oxidase 4 (NOX4) mediates hypercholesterolemia-induced oxidative/nitrative stress and subsequent dysfunction in the heart. J Mol Cell Cardiol 2013; 62:111-21. [PMID: 23722270 DOI: 10.1016/j.yjmcc.2013.05.009] [Citation(s) in RCA: 135] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/06/2012] [Revised: 05/13/2013] [Accepted: 05/17/2013] [Indexed: 01/27/2023]
Abstract
Diet-induced hypercholesterolemia leads to oxidative/nitrative stress and subsequent myocardial dysfunction. However, the regulatory role of microRNAs in this phenomenon is unknown. We aimed to investigate, whether hypercholesterolemia-induced myocardial microRNA alterations play a role in the development of oxidative/nitrative stress and in subsequent cardiac dysfunction. Male Wistar rats were fed with 2% cholesterol/0.25% cholate-enriched or standard diet for 12weeks. Serum and tissue cholesterol levels were significantly elevated by cholesterol-enriched diet. Left ventricular end-diastolic pressure was significantly increased in cholesterol-fed rats both in vivo and in isolated perfused hearts, indicating diastolic dysfunction. Myocardial expression of microRNAs was affected by cholesterol-enriched diet as assessed by microarray analysis. MicroRNA-25 showed a significant down-regulation as detected by microarray analysis and QRT-PCR. In silico target prediction revealed NADPH oxidase 4 (NOX4) as a putative target of microRNA-25. NOX4 protein showed significant up-regulation in the hearts of cholesterol-fed rats, while NOX1 and NOX2 remained unaffected. Cholesterol-feeding significantly increased myocardial oxidative/nitrative stress as assessed by dihydroethidium staining, protein oxidation assay, and nitro-tyrosine ELISA, respectively. Direct binding of microRNA-25 mimic to the 3' UTR region of NOX4 was demonstrated using a luciferase reporter assay. Transfection of a microRNA-25 mimic into primary cardiomyocytes decreased superoxide production, while a microRNA-25 inhibitor resulted in an up-regulation of NOX4 protein and an increase in oxidative stress that was attenuated by the NADPH oxidase inhibitor diphenyleneiodonium. Here we demonstrated for the first time that hypercholesterolemia affects myocardial microRNA expression, and by down-regulating microRNA-25 increases NOX4 expression and consequently oxidative/nitrative stress in the heart. We conclude that hypercholesterolemia-induced microRNA alterations play an important role in the regulation of oxidative/nitrative stress and in consequent myocardial dysfunction.
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Abstract
SIGNIFICANCE In heart failure (HF), contractile dysfunction and arrhythmias result from disturbed intracellular Ca handling. Activated stress kinases like cAMP-dependent protein kinase A (PKA), protein kinase C (PKC), and Ca/calmodulin-dependent protein kinase II (CaMKII), which are known to influence many Ca-regulatory proteins, are mechanistically involved. RECENT ADVANCES Beside classical activation pathways, it is becoming increasingly evident that reactive oxygen species (ROS) can directly oxidize these kinases, leading to alternative activation. Since HF is associated with increased ROS generation, ROS-activated serine/threonine kinases may play a crucial role in the disturbance of cellular Ca homeostasis. Many of the previously described ROS effects on ion channels and transporters are possibly mediated by these stress kinases. For instance, ROS have been shown to oxidize and activate CaMKII, thereby increasing Na influx through voltage-gated Na channels, which can lead to intracellular Na accumulation and action potential prolongation. Consequently, Ca entry via activated NCX is favored, which together with ROS-induced dysfunction of the sarcoplasmic reticulum can lead to dramatic intracellular Ca accumulation, diminished contractility, and arrhythmias. CRITICAL ISSUES While low amounts of ROS may regulate kinase activity, excessive uncontrolled ROS production may lead to direct redox modification of Ca handling proteins. Therefore, depending on the source and amount of ROS generated, ROS could have very different effects on Ca-handling proteins. FUTURE DIRECTIONS The discrimination between fine-tuned ROS signaling and unspecific ROS damage may be crucial for the understanding of heart failure development and important for the investigation of targeted treatment strategies.
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Affiliation(s)
- Stefan Wagner
- Abt. Kardiologie und Pneumologie/Herzzentrum, Deutsches Zentrum für Herzkreislaufforschung, Georg-August-Universität, Göttingen, Germany
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Harrington EO, Ware JA. Diversity of the protein kinase C gene family Implications for cardiovascular disease. Trends Cardiovasc Med 2012; 5:193-9. [PMID: 21232259 DOI: 10.1016/1050-1738(95)00058-h] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
All eukaryotic cells are capable of responding to a changing intracellular environment and to extracellular stimuli. These functional responses are highly regulated by diverse means; one of the most common mechanisms of regulation requires the covalent phosphorylation of intracellular proteins, which when phosphorylated, mediate many functional events. The general class of enzymes that catalyzes the phosphorylation of effectors (substrates), the protein kinases, may be divided into two broad categories, depending on whether they phosphorylate serine and threonine residues or tyrosine residues. Evidence has accumulated that implicates abnormal activation of protein kinase C (PKC), which is one family of serine-threonine protein kinases, in cells and tissues from patients or models of cardiovascular disease. In this review, we present the molecular and biochemical basis for the diversity of the PKC family, and briefly summarize the evidence that PKC is implicated in cardiovascular pathology and the potential therapeutic implications and approaches.
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Affiliation(s)
- E O Harrington
- Elizabeth O. Harrington and J. Anthony Ware are at the Cardiovascular Division of the Department of Medicine, Beth Israel Hospital, Harvard Medical School, Boston, MA 02115, USA.; the Harvard-Thorndike Laboratories of the Department of Medicine, Beth Israel Hospital, Harvard Medical School, Boston, MA 02115, USA
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21
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Sabourin J, Antigny F, Robin E, Frieden M, Raddatz E. Activation of transient receptor potential canonical 3 (TRPC3)-mediated Ca2+ entry by A1 adenosine receptor in cardiomyocytes disturbs atrioventricular conduction. J Biol Chem 2012; 287:26688-701. [PMID: 22692208 DOI: 10.1074/jbc.m112.378588] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Although the activation of the A(1)-subtype of the adenosine receptors (A(1)AR) is arrhythmogenic in the developing heart, little is known about the underlying downstream mechanisms. The aim of this study was to determine to what extent the transient receptor potential canonical (TRPC) channel 3, functioning as receptor-operated channel (ROC), contributes to the A(1)AR-induced conduction disturbances. Using embryonic atrial and ventricular myocytes obtained from 4-day-old chick embryos, we found that the specific activation of A(1)AR by CCPA induced sarcolemmal Ca(2+) entry. However, A(1)AR stimulation did not induce Ca(2+) release from the sarcoplasmic reticulum. Specific blockade of TRPC3 activity by Pyr3, by a dominant negative of TRPC3 construct, or inhibition of phospholipase Cs and PKCs strongly inhibited the A(1)AR-enhanced Ca(2+) entry. Ca(2+) entry through TRPC3 was activated by the 1,2-diacylglycerol (DAG) analog OAG via PKC-independent and -dependent mechanisms in atrial and ventricular myocytes, respectively. In parallel, inhibition of the atypical PKCζ by myristoylated PKCζ pseudosubstrate inhibitor significantly decreased the A(1)AR-enhanced Ca(2+) entry in both types of myocytes. Additionally, electrocardiography showed that inhibition of TRPC3 channel suppressed transient A(1)AR-induced conduction disturbances in the embryonic heart. Our data showing that A(1)AR activation subtly mediates a proarrhythmic Ca(2+) entry through TRPC3-encoded ROC by stimulating the phospholipase C/DAG/PKC cascade provide evidence for a novel pathway whereby Ca(2+) entry and cardiac function are altered. Thus, the A(1)AR-TRPC3 axis may represent a potential therapeutic target.
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Affiliation(s)
- Jessica Sabourin
- Department of Physiology, Faculty of Biology and Medicine, University of Lausanne, 7 rue du Bugnon, CH-1005 Lausanne, Switzerland
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22
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Ferreira JCB, Brum PC, Mochly-Rosen D. βIIPKC and εPKC isozymes as potential pharmacological targets in cardiac hypertrophy and heart failure. J Mol Cell Cardiol 2011; 51:479-84. [PMID: 21035454 PMCID: PMC3135714 DOI: 10.1016/j.yjmcc.2010.10.020] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/06/2010] [Revised: 10/15/2010] [Accepted: 10/19/2010] [Indexed: 01/19/2023]
Abstract
Cardiac hypertrophy is a complex adaptive response to mechanical and neurohumoral stimuli and under continual stressor, it contributes to maladaptive responses, heart failure and death. Protein kinase C (PKC) and several other kinases play a role in the maladaptative cardiac responses, including cardiomyocyte hypertrophy, myocardial fibrosis and inflammation. Identifying specific therapies that regulate these kinases is a major focus of current research. PKC, a family of serine/threonine kinases, has emerged as potential mediators of hypertrophic stimuli associated with neurohumoral hyperactivity in heart failure. In this review, we describe the role of PKC isozymes that is involved in cardiac hypertrophy and heart failure. This article is part of a special issue entitled "Key Signaling Molecules in Hypertrophy and Heart Failure".
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Affiliation(s)
- Julio Cesar Batista Ferreira
- Department of Chemical and Systems Biology, Stanford University School of Medicine, CCSR, Rm 3145A, 269 Campus Drive, Stanford, CA 94305-5174, USA
- School of Physical Education and Sport, University of Sao Paulo, SP 05508-900, Brazil
| | - Patricia Chakur Brum
- School of Physical Education and Sport, University of Sao Paulo, SP 05508-900, Brazil
| | - Daria Mochly-Rosen
- Department of Chemical and Systems Biology, Stanford University School of Medicine, CCSR, Rm 3145A, 269 Campus Drive, Stanford, CA 94305-5174, USA
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Duquesnes N, Lezoualc'h F, Crozatier B. PKC-delta and PKC-epsilon: foes of the same family or strangers? J Mol Cell Cardiol 2011; 51:665-73. [PMID: 21810427 DOI: 10.1016/j.yjmcc.2011.07.013] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/05/2011] [Revised: 06/24/2011] [Accepted: 07/15/2011] [Indexed: 11/30/2022]
Abstract
Protein kinase C (PKC) is a family of 10 serine/threonine kinases divided into 3 subfamilies, classical, novel and atypical classes. Two PKC isozymes of the novel group, PKCε and PKCδ, have different and sometimes opposite effects. PKCε stimulates cell growth and differentiation while PKCδ is apoptotic. In the heart, they are among the most expressed PKC isozymes and they are opposed in the preconditioning process with a positive role of PKCε and an inhibiting role of PKCδ. The goal of this review is to analyze the structural differences of these 2 enzymes that may explain their different behaviors and properties.
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Kooij V, Stienen GJM, van der Velden J. The role of protein kinase C-mediated phosphorylation of sarcomeric proteins in the heart-detrimental or beneficial? Biophys Rev 2011; 3:107. [PMID: 28510060 DOI: 10.1007/s12551-011-0050-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2011] [Accepted: 06/08/2011] [Indexed: 10/18/2022] Open
Abstract
Protein kinase C (PKC) is a family of serine/threonine protein kinases, and alterations have been found in PKC isoform expression and localization in the failing heart. These alterations in PKC activation levels influence the PKC-mediated phosphorylation status of cellular target proteins involved in Ca2+-handling and sarcomeric contraction. The differences observed in the effects due to PKC-mediated phosphorylation may underlie part of the contractile dysfunction observed in the failing heart. It is therefore important to establish the beneficial and detrimental effects of this kinase in the healthy and failing heart. The function of PKC has been studied intensively; however, the complexity of the regulation of this kinase makes the interpretation of the different effects difficult. The main focus of this review is the (patho)physiological impact of phosphorylation of sarcomeric proteins, myosin light chain-2, troponin I and T, desmin, myosin binding protein-C, and titin by PKC.
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Affiliation(s)
- Viola Kooij
- Division of Cardiology, Johns Hopkins Bayview Proteomics Center, Johns Hopkins University, 5200 Eastern Avenue, MFL Bldg, Center Tower, Rm 601, Baltimore, MD, 21224, USA.
| | - Ger J M Stienen
- Laboratory for Physiology, Institute for Cardiovascular Research, VU University Medical Center, Amsterdam, The Netherlands
| | - Jolanda van der Velden
- Laboratory for Physiology, Institute for Cardiovascular Research, VU University Medical Center, Amsterdam, The Netherlands
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Choudhary G, Troncales F, Martin D, Harrington EO, Klinger JR. Bosentan attenuates right ventricular hypertrophy and fibrosis in normobaric hypoxia model of pulmonary hypertension. J Heart Lung Transplant 2011; 30:827-33. [PMID: 21550822 DOI: 10.1016/j.healun.2011.03.010] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2011] [Revised: 02/14/2011] [Accepted: 03/06/2011] [Indexed: 01/21/2023] Open
Abstract
BACKGROUND Maladaptive right ventricular (RV) hypertrophic responses lead to RV dysfunction and failure in patients with pulmonary arterial hypertension, but the mechanisms responsible for these changes are not well understood. The objective of this study was to evaluate the effect of treatment with bosentan on RV hypertrophy (RVH), fibrosis and expression of protein kinase C (PKC) isoforms in the RV of rats exposed to chronic hypoxia. METHODS Adult Sprague-Dawley rats were housed in normoxia or hypoxia (FIO(2) = 10%) and administered vehicle or 100 mg/kg/day bosentan. After 3 weeks, echocardiographic and hemodynamic assessment was performed. PKC, procollagen-1 and collagen expression levels were assessed using immunoblot or colorimetric assay. RESULTS RV systolic pressure (RVSP) and RVH were higher in hypoxic compared with normoxic animals (RVSP: 72 ± 4 vs 25 ± 2 mm Hg, p < 0.05; RVH: 1.2 ± 0.06 vs 0.5 ± 0.03 mg/g body weight, p < 0.05). Bosentan had no effect on RVSP or mass in normoxic animals, but did attenuate RVH in hypoxic animals (hypoxic/vehicle: 1.2 ± 0.06; hypoxic/bosentan: 1.0 ± 0.05 mg/g body weight; p < 0.05). Hypoxia increased RV procollagen-1, and total collagen expression, effects that were attenuated by bosentan treatment. Hypoxia increased RV total and cytosolic PKC-δ protein expression, but had no effect on PKC-α or -ε isoforms. Administration with bosentan did not affect total PKC-δ protein expression. However, animals treated with bosentan had an increase in membranous PKC-δ when exposed to hypoxia. CONCLUSIONS Bosentan inhibits RVH and RV collagen expression in rats exposed to chronic hypoxia, possibly via alteration of PKC-δ activity.
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Affiliation(s)
- Gaurav Choudhary
- Vascular Research Laboratory, Providence VA Medical Center, Providence, Rhode Island 02908, USA.
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26
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Huang Y, Zhang H, Shao Z, O'Hara KA, Kopilas MA, Yu L, Netticadan T, Anderson HD. Suppression of endothelin-1-induced cardiac myocyte hypertrophy by PPAR agonists: role of diacylglycerol kinase zeta. Cardiovasc Res 2010; 90:267-75. [DOI: 10.1093/cvr/cvq401] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
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Dhalla NS, Müller AL. Protein Kinases as Drug Development Targets for Heart Disease Therapy. Pharmaceuticals (Basel) 2010; 3:2111-2145. [PMID: 27713345 PMCID: PMC4036665 DOI: 10.3390/ph3072111] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2010] [Revised: 06/03/2010] [Accepted: 06/23/2010] [Indexed: 02/07/2023] Open
Abstract
Protein kinases are intimately integrated in different signal transduction pathways for the regulation of cardiac function in both health and disease. Protein kinase A (PKA), Ca²⁺-calmodulin-dependent protein kinase (CaMK), protein kinase C (PKC), phosphoinositide 3-kinase (PI3K) and mitogen-activated protein kinase (MAPK) are not only involved in the control of subcellular activities for maintaining cardiac function, but also participate in the development of cardiac dysfunction in cardiac hypertrophy, diabetic cardiomyopathy, myocardial infarction, and heart failure. Although all these kinases serve as signal transducing proteins by phosphorylating different sites in cardiomyocytes, some of their effects are cardioprotective whereas others are detrimental. Such opposing effects of each signal transduction pathway seem to depend upon the duration and intensity of stimulus as well as the type of kinase isoform for each kinase. In view of the fact that most of these kinases are activated in heart disease and their inhibition has been shown to improve cardiac function, it is suggested that these kinases form excellent targets for drug development for therapy of heart disease.
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Affiliation(s)
- Naranjan S Dhalla
- Institute of Cardiovascular Sciences, St. Boniface Hospital Research, and Department of Physiology, Faculty of Medicine, University of Manitoba, Winnipeg, MB R2H 2A6, Canada.
| | - Alison L Müller
- Institute of Cardiovascular Sciences, St. Boniface Hospital Research, and Department of Physiology, Faculty of Medicine, University of Manitoba, Winnipeg, MB R2H 2A6, Canada.
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Sun Q, Zang WJ, Chen C. Growth hormone secretagogues reduce transient outward K+ current via phospholipase C/protein kinase C signaling pathway in rat ventricular myocytes. Endocrinology 2010; 151:1228-35. [PMID: 20056829 DOI: 10.1210/en.2009-0877] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Endogenous ghrelin and its synthetic counterpart hexarelin are peptide GH secretagogues (GHS) that exert a positive ionotropic effect in the cardiovascular system. The mechanism by which GHS modulate cardiac electrophysiology properties to alter myocyte contraction is poorly understood. In the present study, we examined whether GHS regulates the transient outward potassium current (I(to)) as well as the putative intracellular signaling cascade responsible for such regulation. GHS and experimental agents were applied locally onto freshly isolated adult Sprague-Dawley rat ventricular myocytes and action potential morphology and I(to) was recorded using nystatin-perforated whole-cell patch-clamp recording technique. Under current clamp, ghrelin and hexarelin (10 nm) significantly prolonged action potential duration. Under voltage clamp, hexarelin and ghrelin inhibited I(to) in a concentration-dependent manner. This inhibition was abolished in the presence of the GHS receptor (GHS-R) antagonist [D-Lys(3)]GH-releasing peptide-6 (10 microm) and GHS-R1a-specific antagonist BIM28163 (1 microm). GHS-induced I(to) inhibition was totally reversed by the phospholipase C inhibitor U73122 (5 microm) and protein kinase C inhibitors GO6983 (1 microm) and calphostin C (0.1 microm) but not by the cAMP antagonist Rp-cAMP (100 microm) or the PKA inhibitor H89 (1 microm). We conclude that hexarelin and ghrelin activate phospholipase C and protein kinase C signaling cascade through the stimulation of the GHS-R, resulting in a decrease in the I(to) current and subsequent prolongation of action potential duration.
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Affiliation(s)
- Qiang Sun
- Department of Pharmacology, School of Medicine, Xi'an Jiaotong University, Xi'an 710061, China
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Wei H, Vander Heide RS. Ischemic preconditioning and heat shock activate Akt via a focal adhesion kinase-mediated pathway in Langendorff-perfused adult rat hearts. Am J Physiol Heart Circ Physiol 2009; 298:H152-7. [PMID: 19880666 DOI: 10.1152/ajpheart.00613.2009] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Heat stress (HS)-induced cardioprotection is associated with the activation of focal adhesion kinase (FAK) and protein kinase B (Akt) in neonatal rat ventricular myocytes (NRVMs), suggesting that stress-induced activation of survival pathways may be important in protecting intact hearts from irreversible injury. The purposes of this study were 1) to examine the subcellular signaling pathways activated by HS and ischemic preconditioning (IP) in intact hearts, 2) to determine whether HS and IP activate an integrated survival pathway similar to that activated by HS in cultured NRVMs, and 3) to determine whether HS and IP reduce lethal cell injury in perfused intact hearts. Adult rat hearts perfused in the Langendorff mode were subjected to 25 min of global ischemia and 30 min of reperfusion (I/R) either 24 h after whole animal HS or following a standard IP protocol. Myocardial signaling was analyzed using Western blot analysis, whereas cell death was assayed by measuring lactate dehydrogenase release into the perfusate and confirmed by light microscopy. Similar to NRVMs, HS performed in the whole animal 24 h before I/R increased phosphorylation of FAK at tyrosine-397 and protein kinase B (Akt) and resulted in protection from cell death. Using IP as a myocardial stress also resulted in an increased phosphorylation/activation of both FAK and Akt and resulted in reduced cell death in adult perfused rat hearts subjected to I/R. In conclusion, 1) myocardial stress caused by whole animal HS activates cytoskeletal-based survival signaling pathways in whole heart tissue and reduces lethal I/R injury and 2) IP activates the same stress-induced survival pathway and the activation correlates with the well-known cardioprotective effect of IP on lethal I/R injury.
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Affiliation(s)
- Hongguang Wei
- Department of Pathology, Wayne State University Medical School, Detroit, Michigan, USA
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Wei H, Vander Heide RS. Heat stress activates AKT via focal adhesion kinase-mediated pathway in neonatal rat ventricular myocytes. Am J Physiol Heart Circ Physiol 2008; 295:H561-8. [PMID: 18539755 DOI: 10.1152/ajpheart.00401.2008] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Heat stress (HS)-induced cardioprotection is associated with increased paxillin localization to the membrane fraction of neonatal rat ventricular myocytes (NRVM). The purpose of this study was 1) to examine the subcellular signaling pathways activated by HS; 2) to determine whether myocardial stress organizes and activates an integrated survival pathway; and 3) to investigate potential downstream cytoprotective proteins activated by HS. After HS, NRVM were subjected to chemical inhibitors (CI) designed to simulate ischemia by inhibiting both glycolysis and mitochondrial respiration. Protein kinase B (AKT) expression (wild type) was increased selectively with an adenoviral vector. Cell signaling was analyzed with Western blot analysis, while oncosis/apoptosis was assayed by measuring Trypan blue exclusion and/or terminal deoxynucleotidyltransferase-mediated dUTP nick end labeling (TUNEL) staining, respectively. HS increased phosphorylation of focal adhesion kinase (FAK) at tyrosine 397 but did not adversely affect the viability of NRVM before CI. HS increased association between FAK and phosphatidylinositol 3-kinase as well as causing a significant increase in AKT activity. Increased expression of wild-type AKT protected myocytes from both oncotic and apoptotic cell death. Increased expression of a FAK inhibitor, FRNK, reduced AKT phosphorylation in response to HS both at time 0 and after 10 min of CI compared with myocytes expressing empty virus. We conclude that myocardial stress activates cytoskeleton-based signaling pathways that are associated with protection from lethal cell injury.
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Affiliation(s)
- Hongguang Wei
- Dept. of Pathology, Wayne State Univ. Medical School, 540 East Canfield Ave., Detroit, MI 48201, USA
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Churchill E, Budas G, Vallentin A, Koyanagi T, Mochly-Rosen D. PKC isozymes in chronic cardiac disease: possible therapeutic targets? Annu Rev Pharmacol Toxicol 2008; 48:569-99. [PMID: 17919087 DOI: 10.1146/annurev.pharmtox.48.121806.154902] [Citation(s) in RCA: 99] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Cardiovascular disease is the leading cause of death in the United States. Therefore, identifying therapeutic targets is a major focus of current research. Protein kinase C (PKC), a family of serine/threonine kinases, has been identified as playing a role in many of the pathologies of heart disease. However, the lack of specific PKC regulators and the ubiquitous expression and normal physiological functions of the 11 PKC isozymes has made drug development a challenge. Here we discuss the validity of therapeutically targeting PKC, an intracellular signaling enzyme. We describe PKC structure, function, and distribution in the healthy and diseased heart, as well as the development of rationally designed isozyme-selective regulators of PKC functions. The review focuses on the roles of specific PKC isozymes in atherosclerosis, fibrosis, and cardiac hypertrophy, and examines principles of pharmacology as they pertain to regulators of signaling cascades associated with these diseases.
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Affiliation(s)
- Eric Churchill
- Department of Chemical and Systems Biology, Stanford University School of Medicine, Stanford, CA 94305-5174, USA
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Sumeray MS, Yellon DM. Editorial Cardiovascular & Renal: Ischaemic preconditioning: rational basis for drug design. Expert Opin Investig Drugs 2008. [DOI: 10.1517/13543784.5.11.1435] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Indira K. A, Renuka R. N. Multiple signaling pathways coordinately mediate reactive oxygen species dependent cardiomyocyte hypertrophy. Cell Biochem Funct 2008; 26:346-51. [DOI: 10.1002/cbf.1449] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Deschamps AM, Zavadzkas J, Murphy RL, Koval CN, McLean JE, Jeffords L, Saunders SM, Sheats NJ, Stroud RE, Spinale FG. Interruption of endothelin signaling modifies membrane type 1 matrix metalloproteinase activity during ischemia and reperfusion. Am J Physiol Heart Circ Physiol 2007; 294:H875-83. [PMID: 18065523 DOI: 10.1152/ajpheart.00918.2007] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The matrix metalloproteinases (MMPs), in particular, membrane type 1 MMP (MT1-MMP), are increased in the context of myocardial ischemia and reperfusion (I/R) and likely contribute to myocardial dysfunction. One potential upstream induction mechanism for MT1-MMP is endothelin (ET) release and subsequent protein kinase C (PKC) activation. Modulation of ET and PKC signaling with respect to MT1-MMP activity with I/R has yet to be explored. Accordingly, this study examined in vivo MT1-MMP activation during I/R following modification of ET signaling and PKC activation. With the use of a novel fluorogenic microdialysis system, myocardial interstitial MT1-MMP activity was measured in pigs (30 kg; n = 9) during I/R (90 min I/120 min R). Local ET(A) receptor antagonism (BQ-123, 1 microM) and PKC inhibition (chelerythrine, 1 microM) were performed in parallel microdialysis probes. MT1-MMP activity was increased during I/R by 122 +/- 10% (P < 0.05) and was unchanged from baseline with ET antagonism and/or PKC inhibition. Selective PKC isoform induction occurred such that PKC-betaII increased by 198 +/- 31% (P < 0.05). MT1-MMP phosphothreonine, a putative PKC phosphorylation site, was increased by 121 +/- 8% (P < 0.05) in the I/R region. These studies demonstrate for the first time that increased interstitial MT1-MMP activity during I/R is a result of the ET/PKC pathway and may be due to enhanced phosphorylation of MT1-MMP. These findings identify multiple potential targets for modulating a local proteolytic pathway operative during I/R.
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Affiliation(s)
- Anne M Deschamps
- Division of Cardiothoracic Surgery, Medical University of South Carolina, Charleston, SC 29403, USA
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Simonis G, Briem SK, Schoen SP, Bock M, Marquetant R, Strasser RH. Protein kinase C in the human heart: differential regulation of the isoforms in aortic stenosis or dilated cardiomyopathy. Mol Cell Biochem 2007; 305:103-11. [PMID: 17594058 DOI: 10.1007/s11010-007-9533-3] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2007] [Accepted: 06/08/2007] [Indexed: 10/23/2022]
Abstract
OBJECTIVES Protein kinase C (PKC) is a central enzyme in the regulation of growth and hypertrophy. Little was known on PKC isoform regulation in human heart. Goal of this study was to characterize the isoforms of protein kinase C in human heart, their changes during ontogenesis, and their regulation in myocardial hypertrophy and heart failure. METHODS In left ventricular and atrial samples from adults with end-stage dilated cardiomyopathy (DCM), from adults with severe aortic stenosis (AS), from small infants undergoing repair of ventricular septal defects, and from healthy organ donors (CO), activity of protein kinase C and the expression of its isozymes were examined. RESULTS In the adult human heart, the isoforms PKC-alpha, PCK-beta, PKC-delta, PKC-epsilon, PKC-lambda/-iota, and PKC-zeta were detected both on protein and on mRNA level. All isozymes are subjected to downregulation during ontogenesis. No evidence, however, exists for an isoform shift from infancy to adulthood. DCM leads to a pronounced upregulation of PKC-beta. Severe left ventricular hypertrophy in AS, however, recruits a distinct isoform pattern, i.e., isoforms PKC-alpha, PKC-delta, PKC-epsilon, PKC-lambda/-iota, and PKC-zeta are upregulated, whereas PKC-beta is not changed under this condition. CONCLUSION This work gives evidence for a differential recruitment of human PKC isoforms in various forms of myocardial hypertrophy and heart failure.
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Affiliation(s)
- Gregor Simonis
- Department of Medicine/Cardiology, Dresden University of Technology, Fetscherstr. 76, Dresden, 01307, Germany.
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Zhang H, Darwanto A, Linkhart TA, Sowers LC, Zhang L. Maternal cocaine administration causes an epigenetic modification of protein kinase Cepsilon gene expression in fetal rat heart. Mol Pharmacol 2007; 71:1319-28. [PMID: 17202284 DOI: 10.1124/mol.106.032011] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Protein kinase Cepsilon (PKCepsilon) plays a pivotal role in cardioprotection during cardiac ischemia and reperfusion injury. Recent studies demonstrated that prenatal cocaine exposure caused a decrease in PKCepsilon expression and increased heart susceptibility to ischemic injury in adult offspring, suggesting an in utero programming of PKCepsilon gene expression pattern in the heart. The present investigation aimed to elucidate whether an epigenetic mechanism, DNA methylation, accounts for cocaine-mediated repression of the PKCepsilon gene in the heart. Pregnant rats were administered either saline or cocaine intraperitoneally (15 mg/kg) twice daily from days 15 to 20 of gestational age, and term fetal hearts were studied. Cocaine treatment significantly decreased PKCepsilon mRNA and protein levels in the heart. CpG dinucleotides found in cAMP response element-binding protein (CREB), CREB/c-Jun1, and CREB/c-Jun2 binding sites at the proximal promoter region of the PKCepsilon gene were densely methylated and were not affected by cocaine. In contrast, methylation of CpGs in the activator protein 1 (AP-1) binding sites was low but was significantly increased by cocaine. Reporter gene assays showed that the AP-1 binding site played a strong stimulatory role of PKCepsilon gene transcription. Methylation of the AP-1 binding sites significantly decreased AP-1 binding to the PKCepsilon promoter. Supershift analyses implicated c-Jun homodimers binding to the AP-1 binding sites. Cocaine did not affect nuclear c-Jun levels or the binding of c-Jun to the unmethylated AP-1 binding sites. The results indicate a role for DNA methylation in cocaine-mediated PKCepsilon gene repression in the developing heart and suggest an epigenetic mechanism affecting this gene linked with vulnerability of ischemic injury in the heart of adult offspring.
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Affiliation(s)
- Haitao Zhang
- Center for Perinatal Biology, Department of Pharmacology and Physiology, Loma Linda University School of Medicine, Loma Linda, CA 92350, USA
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He H, Wang W, Zhang H, Ma L, Wu H, Wang P, Gao J. Fosinopril and Carvedilol Reverse Hypertrophy and Change the Levels of Protein Kinase Cɛ and Components of its Signaling Complex. Cardiovasc Drugs Ther 2006; 20:259-71. [PMID: 17039281 DOI: 10.1007/s10557-006-0079-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVE To demonstrate the alterations of Protein Kinase C epsilon (PKC epsilon) and components of its signaling complexes after treatment with fosinopril and carvedilol and analyze potential molecular mechanisms of the two drugs for cardiac hypertrophy and heart failure. METHODS Pressure-overload cardiac hypertrophy (POH) was developed in 8-week-old male Sprague Dawley rats by abdominal aortic banding. The rats were divided into three groups at the age of 20 weeks: POH without failure group, reversed POH with drugs group, and POH with failure group on high diet. Western Blot analysis, co-immunoprecipitation and proteomic analysis were performed in ventricular tissues of rat hearts. RESULTS Increased PKC epsilon was found during POH. PKC epsilon decreased during transition from POH to heart failure (HF). However, increased PKC epsilon inclined to recover to normal levels after treatment with both drugs. There were differential proteins in PKC epsilon complexes during the different stages of POH. The two significant PKC epsilon-binding proteins, MAD1 and Lyn A, were only present in PKC epsilon complex during reversing POH with drugs. CONCLUSION Chronic administration of carvedilol and fosinopril could reverse the development of POH and delay the appearance of HF, partly by regulating PKC epsilon level and its signaling complex. MAD1 and Lyn A may be important proteins participating in the reversing process.
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Affiliation(s)
- Hua He
- Department of Internal Medicine, Cardiovascular Institute and Fuwai Hospital, Chinese Academy of Medical Sciences, Peking Union Medical College, No167 BeiLishi Road, Xicheng District, Beijing, 100037, People's Republic of China
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Apple KA, McLean JE, Squires CE, Schaeffer B, Sample JA, Murphy RL, Deschamps AM, Leonardi AH, Allen CM, Hendrick JW, Stroud RE, Mukherjee R, Spinale FG. Differential effects of protein kinase C isoform activation in endothelin-mediated myocyte contractile dysfunction with cardioplegic arrest and reperfusion. Ann Thorac Surg 2006; 82:664-71. [PMID: 16863782 DOI: 10.1016/j.athoracsur.2006.03.021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/04/2005] [Revised: 03/06/2006] [Accepted: 03/07/2006] [Indexed: 10/24/2022]
Abstract
BACKGROUND Increased myocardial interstitial levels of endothelin (ET) occur during cardioplegic arrest (CA) and may contribute to contractile dysfunction. Endothelin receptor transduction involves the protein kinase-C (PKC) family comprised of multiple isoforms with diverse functions. Which PKC isoforms may be involved in ET-induced contractile dysfunction after CA remains unknown. METHODS Shortening velocity was measured in isolated left ventricular porcine myocytes and randomized (minimum of 30 per group): normothermia (cell culture media for 2 hours at 37 degrees C); CA (2 hours in CA solution [4 degrees C, 24 mEq K+] followed by reperfusion in cell media); ET/CA (100 pM ET incubated during CA and reperfusion). These studies were carried out in the presence and absence of PKC inhibitors (500 nM) and directed against members of the classical PKC subfamily (beta I, beta II, gamma) and the novel subfamily (epsilon, eta). RESULTS Cardiac arrest reduced shortening velocity by approximately 50%, which was further reduced in the presence of ET. Inhibition of either the beta II or gamma PKC isoform significantly increased shortening velocity from ET/CA as well as CA only values. In separate studies (n = 3), total beta II and phosphorylated beta II increased by over 150% with ET/CA (p < 0.05). Taken together, these results suggest that a predominant intracellular effector for the negative contractile effects mediated by ET in the context of CA is the PKC isoform beta II. CONCLUSIONS Targeted inhibition of specific PKC isoforms relieves the negative inotropic effects of ET after simulated CA. These findings provide important mechanistic support for the development of targeted inhibitory strategies with respect to ET signaling and myocyte contractile dysfunction in the context of CA and reperfusion.
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Affiliation(s)
- Kimberly A Apple
- Division of Cardiothoracic Surgery, Medical University of South Carolina, and The Ralph H. Johnson Veteran's Affairs Medical Center, Charleston, South Carolina 29425, USA
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Jideama NM, Crawford BH, Hussain AKMA, Raynor RL. Dephosphorylation specificities of protein phosphatase for cardiac troponin I, troponin T, and sites within troponin T. Int J Biol Sci 2006; 2:1-9. [PMID: 16585947 PMCID: PMC1415850 DOI: 10.7150/ijbs.2.1] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2006] [Accepted: 03/01/2006] [Indexed: 11/25/2022] Open
Abstract
Protein dephosphorylation by protein phosphatase 1 (PP1), acting in concert with protein kinase C (PKC) and protein kinase A (PKA), is a pivotal regulatory mechanism of protein phosphorylation. Isolated rat cardiac myofibrils phosphorylated by PKC/PKA and dephosphorylated by PP1 were used in determining dephosphorylation specificities, Ca2+-stimulated Mg2+ATPase activities, and Ca2+ sensitivities. In reconstituted troponin (Tn) complex, PP1 displayed distinct substrate specificity in dephosphorylation of TnT preferentially to TnI, in vitro. In situ phosphorylation of cardiomyocytes with calyculin A, a protein phosphatase inhibitor, resulted in an increase in the phosphorylation stiochiometry of TnT (0.3 to 0.5 (67%)), TnI (2.6 to 3.6 (38%)), and MLC2 (0.4 to 1.7 (325%)). These results further confirmed that though MLC2 is the preferred target substrate for protein phosphatase in the thick filament, the Tn complex (TnI and TnT) from thin filament and C-protein in the thick filament are also protein phosphatase substrates. Our in vitro dephosphorylation experiments revealed that while PP1 differentially dephosphorylated within TnT at multiple sites, TnI was uniformly dephosphorylated. Phosphopeptide maps from the in vitro experiments show that TnT phosphopeptides at spots 4A and 4B are much more resistant to PP1 dephosphorylation than other TnT phosphopeptides. Mg2+ATPase assays of myofibrils phosphorylated by PKC/PKA and dephosphorylated by PP1 delineated that while PKC and PKA phosphorylation decreased the Ca2+-stimulated Mg2+ATPase activities, dephosphorylation antagonistically restored it. PKC and PKA phosphorylation decreased Ca2+ sensitivity to 3.6 µM and 5.0 µM respectively. However, dephosphorylation restored the Mg2+ATPase activity of PKC (99%) and PKA (95%), along with the Ca2+ sensitivities (3.3 µM and 3.0 µM, respectively).
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Affiliation(s)
- Nathan M Jideama
- Department of Biological Sciences, Clark Atlanta University, Atlanta, GA 30314, USA.
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Bullard TA, Borg TK, Price RL. The expression and role of protein kinase C in neonatal cardiac myocyte attachment, cell volume, and myofibril formation is dependent on the composition of the extracellular matrix. MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2005; 11:224-34. [PMID: 16060975 DOI: 10.1017/s1431927605050476] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2004] [Accepted: 11/22/2004] [Indexed: 05/03/2023]
Abstract
The extracellular matrix (ECM) is a dynamic component of tissues that influences cellular phenotype and behavior. We sought to determine the role of specific ECM substrates in the regulation of protein kinase C (PKC) isozyme expression and function in cardiac myocyte attachment, cell volume, and myofibril formation. PKC isozyme expression was ECM substrate specific. Increasing concentrations of the PKC delta inhibitor rottlerin attenuated myocyte attachment to randomly organized collagen (1, 5, and 10 microM), laminin (5 and 10 microM), aligned collagen (5 and 10 microM), and fibronectin (10 microM). Rottlerin significantly decreased cell volume on laminin and randomly organized collagen, and inhibited myofibril formation on laminin. The PKC alpha inhibitor Gö 6976 inhibited attachment to randomly organized collagen at 6 nM but did not affect cell volume. The general PKC inhibitor Bisindolylmalemide I (10 and 30 microM) did not affect myocyte attachment; however, it significantly decreased cell volume on randomly organized collagen. Our data indicate that PKC isozymes are expressed and utilized by neonatal cardiac myocytes during attachment, cell growth, and myofibril formation. Specifically, it appears that PKC delta and/or its downstream effectors play an important role in the interaction between cardiac myocytes and laminin, providing further evidence that the ECM influences cardiac myocyte behavior.
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Affiliation(s)
- Tara A Bullard
- Center for Cellular and Molecular Cardiology, University of Rochester Medical Center, Rochester, NY 14642, USA
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Bae S, Gilbert RD, Ducsay CA, Zhang L. Prenatal cocaine exposure increases heart susceptibility to ischaemia-reperfusion injury in adult male but not female rats. J Physiol 2005; 565:149-58. [PMID: 15677681 PMCID: PMC1464496 DOI: 10.1113/jphysiol.2005.082701] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
The present study tested the hypothesis that prenatal cocaine exposure differentially regulates heart susceptibility to ischaemia-reperfusion (I/R) injury in adult offspring male and female rats. Pregnant rats were administered intraperitoneally either saline or cocaine (15 mg kg(-1)) twice daily from day 15 to day 21 of gestational age. There were no differences in maternal weight gain and birth weight between the two groups. Hearts were isolated from 2-month-old male and female offspring and were subjected to I/R (25 min/60 min) in a Langendorff preparation. Preischaemic values of left ventricular (LV) function were the same between the saline control and cocaine-treated hearts for both male and female rats. Prenatal cocaine exposure significantly increased I/R-induced myocardial apoptosis and infarct size, and significantly attenuated the postischaemic recovery of LV function in adult male offspring. In contrast, cocaine did not affect I/R-induced injury and postischaemic recovery of LV function in the female hearts. There was a significant decrease in PKCepsilon and phospho-PKCepsilon levels in LV in the male, but not female, offspring exposed to cocaine before birth. These results suggest that prenatal cocaine exposure causes a sex-specific increase in heart susceptibility to I/R injury in adult male offspring, and the decreased PKCepsilon gene expression in the male heart may play an important role.
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Affiliation(s)
- Soochan Bae
- Center for Perinatal Biology, Department of Physiology and Pharmacology, Loma Linda University School of Medicine, Loma Linda, CA 92350, USA
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Hunter JC, Korzick DH. Protein kinase C distribution and translocation in rat myocardium: Methodological considerations. J Pharmacol Toxicol Methods 2004; 51:129-38. [PMID: 15767206 DOI: 10.1016/j.vascn.2004.10.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2004] [Accepted: 10/07/2004] [Indexed: 10/26/2022]
Abstract
INTRODUCTION Protein kinase C (PKC) is an important modifier of several cardiovascular phenomena, including cardioprotection, apoptosis, and hypertrophy. Although pharmacological activation of PKC is often assessed by translocation, the effects of isolation procedures on left ventricular (LV) PKC distribution have not been systematically examined. Accordingly, we sought to determine whether homogenization methods (Polytron, glass-glass tissue grinder), detergent selection and concentration, or centrifugation protocols affect PKC (alpha, epsilon) distribution or phorbol-12-myristate-13-acetate (PMA)-induced translocation. METHODS Hearts of male F344 or Wistar rats were Langendorff perfused with either 100 nM PMA or vehicle, and LV cytosolic and particulate PKC (alpha, epsilon) distributions were assessed by differential centrifugation and Western blotting. RESULTS Following 100000 xg centrifugation of the homogenate, resuspension of the pellet (P(1)) in 0.1% sodium dodecyl sulfate (SDS) increased electrophoretic mobility of PKC (alpha, epsilon) such that PKCepsilon comigrated with a nonspecific band. Resuspension of P(1) in Triton X-100 (TX) did not affect mobility but decreased P(1) PKC (alpha, epsilon) levels in a TX-concentration-dependent manner; however, this decrease was found to be due to differential protein solubilization. Decreased levels of PKC (alpha, epsilon) were also noted in soluble and P(2) (supernatant of 100000 xg centrifugation of P(1)) fractions due to increased Polytron burst and total homogenization times. Interestingly, the P(2) fraction also revealed Polytron-dependent decreases (47% vs. glass-glass tissue grinder; p<0.05) in PKCepsilon following an initial 1000 xg centrifugation and an increased PMA-dependent translocation of PKC (alpha, epsilon; 2.4-fold and 1.6-fold, respectively, vs. P(1); p<0.05). DISCUSSION Taken together, these results suggest that PKC isolation procedures should be carefully considered when designing or comparing LV PKC studies due to the potential effects isolation may have on PKC distribution and translocation.
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Affiliation(s)
- J Craig Hunter
- The Noll Physiological Research Center, The Pennsylvania State University, University Park, PA 16802, USA
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LeSage GD, Alvaro D, Glaser S, Francis H, Marucci L, Roskams T, Phinizy JL, Marzioni M, Benedetti A, Taffetani S, Barbaro B, Fava G, Ueno Y, Alpini G. Alpha-1 adrenergic receptor agonists modulate ductal secretion of BDL rats via Ca(2+)- and PKC-dependent stimulation of cAMP. Hepatology 2004; 40:1116-27. [PMID: 15486932 DOI: 10.1002/hep.20424] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Acetylcholine potentiates secretin-stimulated ductal secretion by Ca(2+)-calcineurin-mediated modulation of adenylyl cyclase. D2 dopaminergic receptor agonists inhibit secretin-stimulated ductal secretion via activation of protein kinase C (PKC)-gamma. No information exists regarding the effect of adrenergic receptor agonists on ductal secretion in a model of cholestasis induced by bile duct ligation (BDL). We evaluated the expression of alpha-1A/1C, -1beta and beta-1 adrenergic receptors in liver sections and cholangiocytes from normal and BDL rats. We evaluated the effects of the alpha-1 and beta-1 adrenergic receptor agonists (phenylephrine and dobutamine, respectively) on bile and bicarbonate secretion and cholangiocyte IP(3) and Ca(2+) levels in normal and BDL rats. We measured the effect of phenylephrine on lumen expansion in intrahepatic bile duct units (IBDUs) and cyclic adenosine monophosphate (cAMP) levels in cholangiocytes from BDL rats in the absence or presence of BAPTA/AM and Gö6976 (a PKC-alpha inhibitor). We evaluated if the effects of phenylephrine on ductal secretion were associated with translocation of PKC isoforms leading to increased protein kinase A activity. Alpha-1 and beta-1 adrenergic receptors were present mostly in the basolateral domain of cholangiocytes and, following BDL, their expression increased. Phenylephrine, but not dobutamine, increased secretin-stimulated choleresis in BDL rats. Phenylephrine did not alter basal but increased secretin-stimulated IBDU lumen expansion and cAMP levels, which were blocked by BAPTA/AM and Go6976. Phenylephrine increased IP(3) and Ca(2+) levels and activated PKC-alpha and PKC-beta-II. In conclusion, coordinated regulation of ductal secretion by secretin (through cAMP) and adrenergic receptor agonist activation (through Ca(2+)/PKC) induces maximal ductal bicarbonate secretion in liver diseases. (Supplementary material for this article can be found on the HEPATOLOGY website (http://interscience.wiley.com/jpages/0270-9139/suppmat/index.html).
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Affiliation(s)
- Gene D LeSage
- Department of Medicine, Scott & White Hospital, and The Texas A&M University System HSC, COM, Temple, TX 76504, USA
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Gallego M, Setién R, Puebla L, Boyano-Adánez MDC, Arilla E, Casis O. alpha1-Adrenoceptors stimulate a Galphas protein and reduce the transient outward K+ current via a cAMP/PKA-mediated pathway in the rat heart. Am J Physiol Cell Physiol 2004; 288:C577-85. [PMID: 15496483 DOI: 10.1152/ajpcell.00124.2004] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
alpha(1)-Adrenoceptor stimulation prolongs the duration of the cardiac action potentials and leads to positive inotropic effects by inhibiting the transient outward K(+) current (I(to)). In the present study, we have examined the role of several protein kinases and the G protein involved in I(to) inhibition in response to alpha(1)-adrenoceptor stimulation in isolated adult rat ventricular myocytes. Our findings exclude the classic alpha(1)-adrenergic pathway: activation of the G protein G(alphaq), phospholipase C (PLC), and protein kinase C (PKC), because neither PLC, nor PKC, nor G(alphaq) blockade prevents the alpha(1)-induced I(to) reduction. To the contrary, the alpha(1)-adrenoceptor does not inhibit I(to) in the presence of protein kinase A (PKA), adenylyl cyclase, or G(alphas) inhibitors. In addition, PKA and adenylyl cyclase activation inhibit I(to) to the same extent as phenylephrine. Finally, we have shown a functional coupling between the alpha(1)-adrenoceptor and G(alphas) in a physiological system. Moreover, this coupling seems to be compartmentalized, because the alpha(1)-adrenoceptor increases cAMP levels only in intact cells, but not in isolated membranes, and the effect on I(to) disappears when the cytoskeleton is disrupted. We conclude that alpha(1)-adrenoceptor stimulation reduces the amplitude of the I(to) by activating a G(alphas) protein and the cAMP/PKA signaling cascade, which in turn leads to I(to) channel phosphorylation.
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Affiliation(s)
- Mónica Gallego
- Department of Physiology, School of Pharmacy, Universidad del País Vasco, Bilbao, Spain
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Ogbi M, Wingard CJ, Ogbi S, Johnson JA. Epsilon protein kinase C lengthens the quiescent period between spontaneous contractions in rat ventricular cardiac myocytes and trabecula. Naunyn Schmiedebergs Arch Pharmacol 2004; 370:251-61. [PMID: 15452687 DOI: 10.1007/s00210-004-0979-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2004] [Accepted: 08/03/2004] [Indexed: 11/25/2022]
Abstract
We have observed a lengthening of the duration between spontaneous cardiac contractions under conditions that preferentially activate the epsilon protein kinase C (epsilonPKC) isozyme. Therefore, we investigated whether this response could be selectively mediated by epsilonPKC in neonatal cardiac myocytes (NCMs) and adult rat ventricular trabeculae. Contraction of NCMs was monitored using light scattering techniques and trabecular force generation was monitored in tissue baths using a force transducer. The involvement of the epsilonPKC isozyme was confirmed using an epsilonPKC-selective translocation inhibitor and Western blot translocation assays. In NCMs 3 nM 4-beta phorbol 12-myristate-13-acetate (PMA) treatment preferentially activates (translocates) epsilonPKC. In this study 3 nM 4-beta PMA induced a 2-fold increase in contractile amplitude and a approximately 14-fold increase in the quiescent period between contractions in NCMs. Extracellular adenosine 5'-triphosphate (ATP) also enhanced contractile amplitude by 1.7-fold and the quiescent period duration by 8-fold. The enhancement of quiescent period duration was attenuated by an epsilonPKC-selective translocation inhibitor. To investigate these relationships in intact myocardium, we studied spontaneously beating adult rat ventricular trabecula. In these fibers contractile amplitude was only modestly enhanced; however, the quiescent period was lengthened by 4.5-fold following a 15-min exposure to 3 nM 4-beta PMA. 4-beta PMA treatment also promoted arrhythmogenesis and increased the association of epsilonPKC with the particulate fraction in these fibers. Our results suggest that epsilonPKC may influence a specific phase of ventricular myocyte spontaneous beating. A better understanding of epsilonPKC modulation of spontaneous cardiac contraction may improve our understanding of the molecular events contributing to ventricular automaticity.
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Affiliation(s)
- Mourad Ogbi
- Department of Pharmacology and Toxicology, Medical College of Georgia, Augusta, GA 30912-2300, USA
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Ooie T, Takahashi N, Nawata T, Arikawa M, Yamanaka K, Kajimoto M, Shinohara T, Shigematsu S, Hara M, Yoshimatsu H, Saikawa T. Ischemia-induced translocation of protein kinase C-epsilon mediates cardioprotection in the streptozotocin-induced diabetic rat. Circ J 2004; 67:955-61. [PMID: 14578604 DOI: 10.1253/circj.67.955] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
The present study investigated the role of translocation of protein kinase C (PKC) during ischemia/reperfusion in cardioprotection in the streptozotocin (STZ)-induced diabetic rat. Twelve weeks after injection of STZ or vehicle, male Wister-King rat hearts were isolated and perfused in the presence or absence of 50 nmol/L staurosporine or 2 mumol/L chelerythrine using a Langendorff apparatus. Thirty minutes of global ischemia was followed by the same period of reperfusion. The time to onset of contracture was determined during ischemia. The recovery of left ventricular function, incidence of ventricular tachycardia/fibrillation (VT/VF), and amount of released creatine kinase (CK) were determined during the reperfusion period. Translocation of the PKC-alpha, -beta, -delta and -epsilon isoforms was determined by immunoblotting. Development of contracture was delayed, the recovery of left ventricular function was greater, and the incidence of VT/VF and amount of released CK were lower in diabetic than in control hearts. Ischemia caused an increase in the particulate/cytosolic fraction ratio of the PKC- epsilon isoform in the diabetic and control hearts. However, this translocation of PKC-epsilon during ischemia was transient in the control heart, but was persistent in the diabetic heart. The ischemia-induced translocation of PKC-epsilon was abolished by chelerythrine perfusion. These results suggest that persistent translocation of PKC-epsilon during ischemia plays a major role in cardioprotection against ischemia/reperfusion injury in STZ-induced diabetic rats.
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Affiliation(s)
- Tatsuhiko Ooie
- Department of Laboratory Medicine, Oita Medical University, Hasama, Japan
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Abstract
Ischemic preconditioning (IPC) is a most powerful endogenous mechanism for myocardial protection against ischemia/reperfusion injury. It is now apparent that reactive oxygen species (ROS) generated in the mitochondrial respiratory chain act as a trigger of IPC. ROS mediate signal transduction in the early phase of IPC through the posttranslational modification of redox-sensitive proteins. ROS-mediated activation of Src tyrosine kinases serves a scaffold for interaction of proteins recruited by G protein-coupled receptors and growth factor receptors that is necessary for amplification of cardioprotective signal transduction. Protein kinase C (PKC) plays a central role in this signaling cascade. A crucial target of PKC is the mitochondrial ATP-sensitive potassium channel, which acts as a trigger and a mediator of IPC. Mitogen-activated protein (MAP) kinases (extracellular signal-regulated kinase, p38 MAP kinase, and c-Jun NH(2)-terminal kinase) are thought to exist downstream of the Src-PKC signaling module, although the role of MAP kinases in IPC remains undetermined. The late phase of IPC is mediated by cardioprotective gene expression. This mechanism involves redox-sensitive activation of transcription factors through PKC and tyrosine kinase signal transduction pathways that are in common with the early phase of IPC. The effector proteins then act against myocardial necrosis and stunning presumably through alleviation of oxidative stress and Ca(2+) overload. Elucidation of IPC-mediated complex signaling processes will help in the development of more effective pharmacological approaches for prevention of myocardial ischemia/reperfusion injury.
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Affiliation(s)
- Hajime Otani
- Department of Thoracic and Cardiovascular Surgery, Kansai Medical University, Moriguchi City, Osaka 570, Japan.
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Rao VU, Shiraishi H, McDermott PJ. PKC-epsilon regulation of extracellular signal-regulated kinase: a potential role in phenylephrine-induced cardiocyte growth. Am J Physiol Heart Circ Physiol 2004; 286:H2195-203. [PMID: 14975926 DOI: 10.1152/ajpheart.00475.2003] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Hypertrophic growth of cardiac muscle is dependent on activation of the PKC-epsilon isoform. To define the effectors of PKC-epsilon involved in growth regulation, recombinant adenoviruses were used to overexpress either wild-type PKC-epsilon (PKC-epsilon/WT) or dominant negative PKC-epsilon (PKC-epsilon/DN) in neonatal rat cardiocytes. PKC-epsilon/DN inhibited acute activation of PKC-epsilon produced in response to phorbol ester and reduced ERK1/2 activity as measured by the phosphorylation of p42 and p44 isoforms. The inhibitory effects were specific to PKC-epsilon because PKC-epsilon/DN did not prevent translocation of either PKC-alpha or PKC-delta. Overexpression of PKC-epsilon/DN blunted the acute increase in ERK1/2 phorphorylation induced by the alpha(1)-adrenergic agonist phenylephrine (PE ). Inhibition of PKC-delta with rottlerin potentiated the effects of PE on ERK1/2 phosphorylation. PKC-epsilon/DN adenovirus also blocked cardiocyte growth as measured after 48 h of PE treatment, although the multiplicity of infection was lower than that required to block acute ERK1/2 activation. PE activated p38 mitogen-activated protein kinase as measured by its phosphorylation, but the response was not blocked by PKC inhibitors or by overexpression of PKC-epsilon/DN. Taken together, these studies show that the hypertrophic agonist PE regulates ERK1/2 activity in cardiocytes by a pathway dependent on PKC-epsilon and that PE-induced growth is mediated by PKC-epsilon.
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Affiliation(s)
- Vijay U Rao
- Cardiology Division, Department of Medicine, Gazes Cardiac Research Institute, Medical University of South Carolina, 303 Thurmond Bldg., 114 Doughty Street, Charleston, SC 29403, USA
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Takahashi T, Anzai T, Yoshikawa T, Maekawa Y, Mahara K, Iwata M, Hammond HK, Ogawa S. Angiotensin receptor blockade improves myocardial beta-adrenergic receptor signaling in postinfarction left ventricular remodeling. J Am Coll Cardiol 2004; 43:125-32. [PMID: 14715194 DOI: 10.1016/j.jacc.2003.07.036] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
OBJECTIVES We tested the hypothesis that angiotensin II type 1 receptor blocker (ARB) may improve beta-adrenergic receptor (AR) coupling in heart failure (HF) after myocardial infarction (MI). BACKGROUND Beta-AR desensitization is one of the mechanisms underlying the transition from compensated to decompensated HF. Beta-adrenergic receptor kinase-1 (ARK1), which can be induced by protein kinase C (PKC) in vitro, is activated in the failing myocardium, resulting in beta-AR uncoupling. METHODS Models of MI in rats were produced by ligation of left coronary artery. Four weeks after surgery, they were randomized to vehicle (MI/control [C]) or candesartan (10 mg/kg/day) treatment (MI/ARB). Sham-operated rats, or shams, served as controls. RESULTS After two weeks of treatment, echocardiography and hemodynamics showed that the left ventricular (LV) dimension increased and that the percent of fractional shortening and maximum rate of rise in left ventricular pressure (dP/dt) decreased in MI rats compared with shams. There were no differences in these indexes between MI/C and MI/ARB. An increase in maximum dP/dt under isoproterenol (ISO) stimulation was attenuated in MI/C but improved in MI/ARB. Reductions in the percentage of high-affinity sites of beta-AR and ISO-stimulated cyclic adenosine monophosphate production in noninfarcted myocardium were also improved by ARB treatment. Up-regulation of beta-ARK1 and PKC-epsilon isoform protein levels and activation of PKC in noninfarcted myocardium from MI/C were both inhibited by ARB treatment. CONCLUSIONS Treatment with ARB during the chronic phase of MI improved beta-AR coupling in noninfarcted myocardium without affecting basal LV function. Cross-talk between beta-AR and angiotensin signaling through beta-ARK1 and PKC-epsilon may be responsible for the phenomenon.
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Affiliation(s)
- Toshiyuki Takahashi
- Cardiopulmonary Division, Department of Medicine, Keio University School of Medicine, Tokyo, Japan
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Fischer-Rasokat U, Doenst T. Insulin-induced improvement of postischemic recovery is abolished by inhibition of protein kinase C in rat heart. J Thorac Cardiovasc Surg 2003; 126:1806-12. [PMID: 14688691 DOI: 10.1016/s0022-5223(03)01229-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVE We demonstrated earlier that postischemic addition of insulin improves recovery of function in isolated rat heart by phosphatidylinositol 3-kinase. Activation of phosphatidylinositol 3-kinase before ischemia improves recovery of the heart after ischemia through protein kinase C. We tested whether protein kinase C activation is required for the positive inotropic effect of insulin during reperfusion. METHODS Isolated working rat hearts were perfused with Krebs-Henseleit buffer containing [2-(3)H]glucose (5 mmol/L, 0.05 microCi/mL) plus oleate (0.4 mmol/L) and were subjected to 15 minutes of global ischemia followed by 35 minutes of reperfusion with or without insulin (1 mU/mL). We measured cardiac power, glucose uptake, and tissue metabolites. The protein kinase C inhibitor chelerythrine (5 micromol/L) was added either at the beginning of the experiment or together with insulin. Experiments were repeated under normoxic conditions. RESULTS Cardiac power before ischemia was 9.63 to 12.4 mW. Insulin improved recovery of power after ischemia (96.3% +/- 10.8% versus 65.7% +/- 3.79%, P <.05). This effect was abolished by chelerythrine (55.3% +/- 6.49%). However, chelerythrine given at reperfusion did not block insulin's effect on recovery (101.0% +/- 4.25%, P <.05). Postischemic glucose uptake was not increased by insulin (3.07 +/- 0.32 before, 3.45 +/- 0.34 micromol/min/gdw after ischemia, not significant) and was not affected by chelerythrine (3.01 +/- 0.26 before, 3.29 +/- 0.32 micromol/min/gdw after ischemia, not significant). Under normoxic conditions, chelerythrine did not influence insulin's effects on glucose uptake or power. CONCLUSION The results suggest that (1) insulin's effect on recovery is dependent on ischemia-induced protein kinase C activation, (2) the activity of protein kinase C during reperfusion may not be important for this effect of insulin, and (3) protein kinase C plays no role in insulin's effect on glucose uptake under normoxic or postischemic conditions.
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