51
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Li C, A. Williams J. Regulation of CCK-induced ERK1/2 activation by PKC epsilon in rat pancreatic acinar cells. AIMS MOLECULAR SCIENCE 2017. [DOI: 10.3934/molsci.2017.4.463] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
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52
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Signaling Pathways in Cardiac Myocyte Apoptosis. BIOMED RESEARCH INTERNATIONAL 2016; 2016:9583268. [PMID: 28101515 PMCID: PMC5215135 DOI: 10.1155/2016/9583268] [Citation(s) in RCA: 97] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/19/2016] [Accepted: 11/20/2016] [Indexed: 12/16/2022]
Abstract
Cardiovascular diseases, the number 1 cause of death worldwide, are frequently associated with apoptotic death of cardiac myocytes. Since cardiomyocyte apoptosis is a highly regulated process, pharmacological intervention of apoptosis pathways may represent a promising therapeutic strategy for a number of cardiovascular diseases and disorders including myocardial infarction, ischemia/reperfusion injury, chemotherapy cardiotoxicity, and end-stage heart failure. Despite rapid growth of our knowledge in apoptosis signaling pathways, a clinically applicable treatment targeting this cellular process is currently unavailable. To help identify potential innovative directions for future research, it is necessary to have a full understanding of the apoptotic pathways currently known to be functional in cardiac myocytes. Here, we summarize recent progress in the regulation of cardiomyocyte apoptosis by multiple signaling molecules and pathways, with a focus on the involvement of these pathways in the pathogenesis of heart disease. In addition, we provide an update regarding bench to bedside translation of this knowledge and discuss unanswered questions that need further investigation.
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53
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Lee JS, Yang DK, Park JH, Kim JO, Park WJ, Cho C, Kim DH. MicroRNA-101b attenuates cardiomyocyte hypertrophy by inhibiting protein kinase C epsilon signaling. FEBS Lett 2016; 591:16-27. [PMID: 27925653 DOI: 10.1002/1873-3468.12508] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2016] [Revised: 11/13/2016] [Accepted: 11/21/2016] [Indexed: 11/10/2022]
Abstract
Previously, a surgical regression model identified microRNA-101b (miR-101b) as a potential inhibitor of cardiac hypertrophy. Here, we investigated the antihypertrophic mechanism of miR-101b using neonatal rat ventricular myocytes. miR-101b markedly suppressed agonist-induced cardiac hypertrophy as shown by cell size and fetal gene expression. By systems biology approaches, we identified protein kinase C epsilon (PKCε) as the major target of miR-101b. Our results from qRT-PCR, western blot, and luciferase reporter assays confirm that PKCε is a direct target of miR-101b. In addition, we found that effectors downstream of PKCε (p-AKT, p-ERK1/2, p-NFAT, and p-GSK3β) are also affected by miR-101b. Our study reveals a novel inhibitory mechanism for miR-101b as a negative regulator of cardiac hypertrophy.
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Affiliation(s)
- Jong Sub Lee
- College of Life Sciences, Gwangju Institute of Science and Technology, Korea
| | - Dong Kwon Yang
- College of Life Sciences, Gwangju Institute of Science and Technology, Korea
| | - Jei Hyoung Park
- College of Life Sciences, Gwangju Institute of Science and Technology, Korea
| | - Jin Ock Kim
- College of Life Sciences, Gwangju Institute of Science and Technology, Korea
| | - Woo Jin Park
- College of Life Sciences, Gwangju Institute of Science and Technology, Korea
| | - Chunghee Cho
- College of Life Sciences, Gwangju Institute of Science and Technology, Korea
| | - Do Han Kim
- College of Life Sciences, Gwangju Institute of Science and Technology, Korea
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54
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Abstract
Epidemiologic evidence has linked trans fatty acids (TFAs) in the diet to coronary heart disease in human populations. It has been estimated that dietary TFAs from partially hydrogenated oils may be responsible for between 30,000 and 100,000 premature coronary deaths per year in the United States. Although it is known that TFAs increase low-density lipoprotein (LDL) cholesterol levels and decrease high-density lipoprotein (HDL) cholesterol levels (markers of coronary heart disease), there is little known about the mechanisms by which TFAs actually function at the cellular level. It is unknown what levels of TFAs are clinically significant and it is unclear how TFAs are associated with cardiac arrhythmias or sudden cardiac death. We hypothesize that TFAs affect membrane structure, thus altering enzymatic pathways that may subsequently induce cardiac arrhythmias and sudden death.
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Affiliation(s)
- Gary P Zaloga
- Clintec Nutrition, One Baxter Parkway, Deerfield, IL 60015, USA.
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55
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Fan Y, Yang YL, Yeh CC, Mann MJ. Spacial and Temporal Patterns of Gene Expression After Cardiac MEK1 Gene Transfer Improve Post-Infarction Remodeling Without Inducing Global Hypertrophy. J Cell Biochem 2016; 118:775-784. [PMID: 27639174 DOI: 10.1002/jcb.25743] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2016] [Accepted: 09/16/2016] [Indexed: 11/11/2022]
Abstract
Alteration of mitogen activated protein (MAP) kinase signaling in transgenic mice can ameliorate post-myocardial infarction (MI) remodeling. However, pre-existing changes in transgenic hearts and clinically unrealistic transgene expression likely affect the response to injury; it is unknown whether clinically relevant induction of transgene expression in an otherwise normal heart can yield similar benefits. Constitutively active MEK1 (aMEK1) or LacZ adeno-associated virus 9 (AAV9) vectors were injected into the left ventricular (LV) chambers of mice either just before or after coronary ligation. Hearts were evaluated via Western blot, quantitative polymerase chain reaction, histology, and echocardiography. AAV9-mediated aMEK1 delivery altered ERK1/2 expression/activation as in transgenic mice. Transgene expression was not immediately detectable but plateaued at 17 days, and therefore did not likely impact acute ischemia as it would in transgenics. With AAV9-aMEK1 injection just prior to MI, robust expression in the infarct border zone during post-MI remodeling increased border zone wall thickness and reduced infarct size versus controls at 4 weeks, but did not induce global hypertrophy. Significant improvements in local and global LV function were observed, as were trends toward a preservation of LV volume. Delivery after ligation significantly lowered transgene expression in the infarct border zone and did not yield structural or functional benefits. The primary benefits observed in transgenic mice, ameliorated remodeling, and reduced chronic infarct size, were achievable via clinically relevant gene transfer of aMEK1, supporting ongoing translational efforts. Important differences, however, were observed, and consideration must be given to the timing and distribution of transgene delivery and expression. J. Cell. Biochem. 118: 775-784, 2017. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Yanying Fan
- Translational Research Laboratory, Division of Cardiothoracic Surgery, University of California San Francisco, San Francisco, California
| | - Yi-Lin Yang
- Translational Research Laboratory, Division of Cardiothoracic Surgery, University of California San Francisco, San Francisco, California
| | - Che-Chung Yeh
- Translational Research Laboratory, Division of Cardiothoracic Surgery, University of California San Francisco, San Francisco, California
| | - Michael J Mann
- Translational Research Laboratory, Division of Cardiothoracic Surgery, University of California San Francisco, San Francisco, California
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56
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Li J, Gao H, Huang J, Wang P, Huang Y, Luo W, Zhang X, Shen P, You J, Cai S, Li Z, Liu P. PKCζ interacts with STAT3 and promotes its activation in cardiomyocyte hypertrophy. J Pharmacol Sci 2016; 132:15-23. [DOI: 10.1016/j.jphs.2016.03.010] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2016] [Revised: 03/18/2016] [Accepted: 03/22/2016] [Indexed: 01/24/2023] Open
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57
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Drosatos K. Fatty old hearts: role of cardiac lipotoxicity in age-related cardiomyopathy. PATHOBIOLOGY OF AGING & AGE RELATED DISEASES 2016; 6:32221. [PMID: 27558317 PMCID: PMC4996860 DOI: 10.3402/pba.v6.32221] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/10/2016] [Revised: 07/29/2016] [Accepted: 07/29/2016] [Indexed: 12/11/2022]
Abstract
Age-related cardiomyopathy accounts for a significant part of heart failure cases. Imbalance of the energetic equilibrium of the heart along with mitochondrial dysfunction and impaired β-adrenergic receptor signaling contributes in the aggravation of cardiac function in the elderly. In this review article, studies that correlate cardiac aging with lipotoxicity are summarized. The involvement of inhibition of peroxisome proliferator-activated receptor-α, β-adrenergic receptor desensitization, and mitochondrial dysfunction as underlying mechanisms for the lipid-driven age-related cardiomyopathy are presented with the aim to indicate potential therapeutic targets for cardiac aging.
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Affiliation(s)
- Konstantinos Drosatos
- Metabolic Biology Laboratory, Department of Pharmacology, Center for Translational Medicine, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, USA;
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58
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Centurione L, Di Giulio C, Santavenere E, Cacchio M, Sabatini N, Rapino C, Bianchi G, Rapino M, Bosco D, Antonucci A, Cataldi A. Protein Kinase Cζ Regulation of Hypertrophic and Apoptotic Events Occurring during Rat Neonatal Heart Development and Growth. Int J Immunopathol Pharmacol 2016; 18:49-58. [PMID: 15698510 DOI: 10.1177/039463200501800106] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
The development and growth of the rat heart implies hyperplasia, which stops at birth, and hypertrophy, allowing cardiac mass to grow in response to programmed genetic events along with to haemodynamic overload. Moreover, hypertrophy is accomplished to apoptosis which controls the final number of myocardial cells, deletes vestigial structures, and takes part in remodelling the organ. Since at the basis of all these processes, which lead to the complete development of the heart, the activation of specific signalling pathways underlies, attention has been addressed to the role played in vivo by Protein Kinase Cζ (PKCζ) in regulating NF-kB signalling system and “intrinsic” mitochondrial apoptotic route at days 1, 4, 10 and 22 of rat life. In fact, a role has been assigned to PKCζ in indirectly phosphorylating IKBα, which peaks between 10 and 22 days, through a IKK determining, in turn, NF-kB activation, concomitantly to cytochrome c/Apaf 1 co-localization in the cytoplasm and caspase-9/caspase-3 activation, which leads to the occurrence of apoptosis. Thus a key role for PKCζ in regulating the hypertrophic and apoptotic events leading to establishment of complete function in rat neonatal heart is here suggested.
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Affiliation(s)
- L Centurione
- Dipartimento di Biomorfologia, Facoltà di Farmacia, Cattedra di Anatomia Umana, University of Chieti, Italy
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59
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Sundararaj K, Pleasant DL, Moschella PC, Panneerselvam K, Balasubramanian S, Kuppuswamy D. mTOR Complexes Repress Hypertrophic Agonist-Stimulated Expression of Connective Tissue Growth Factor in Adult Cardiac Muscle Cells. J Cardiovasc Pharmacol 2016; 67:110-20. [PMID: 26371948 PMCID: PMC7334753 DOI: 10.1097/fjc.0000000000000322] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Connective tissue growth factor (CTGF) is a fibrogenic cytokine that promotes fibrosis in various organs. In the heart, both cardiomyocytes (CM) and cardiac fibroblasts have been reported as a source of CTGF expression, aiding cardiac fibrosis. Although the mammalian target of rapamycin (mTOR) forms 2 distinct complexes, mTORC1 and mTORC2, and plays a central role in integrating biochemical signals for protein synthesis and cellular homeostasis, we explored its role in CTGF expression in adult feline CM. CM were stimulated with 10 μM phenylephrine (PE), 200 nM angiotensin (Ang), or 100 nM insulin for 24 hours. PE and Ang, but not insulin, caused an increase in CTGF mRNA expression with the highest expression observed with PE. Inhibition of mTOR with torin1 but not rapamycin significantly enhanced PE-stimulated CTGF expression. Furthermore, silencing of raptor and rictor using shRNA adenoviral vectors to suppress mTORC1 and mTORC2, respectively, or blocking phosphatidylinositol 3-kinase (PI3K) signaling with LY294002 (LY) or Akt signaling by dominant-negative Akt expression caused a substantial increase in PE-stimulated CTGF expression as measured by both mRNA and secreted protein levels. However, studies with dominant-negative delta isoform of protein kinase C demonstrate that delta isoform of protein kinase C is required for both agonist-induced CTGF expression and mTORC2/Akt-mediated CTGF suppression. Finally, PE-stimulated CTGF expression was accompanied with a corresponding increase in Smad3 phosphorylation and pretreatment of cells with SIS3, a Smad3 specific inhibitor, partially blocked the PE-stimulated CTGF expression. Therefore, a PI3K/mTOR/Akt axis plays a suppressive role on agonist-stimulated CTGF expression where the loss of this mechanism could be a contributing factor for the onset of cardiac fibrosis in the hypertrophying myocardium.
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Affiliation(s)
- Kamala Sundararaj
- Cardiology Division of the Department of Medicine, Gazes Cardiac Research Institute, Medical University of South Carolina, Charleston, SC 29425-2221
| | - Dorea L. Pleasant
- Cardiology Division of the Department of Medicine, Gazes Cardiac Research Institute, Medical University of South Carolina, Charleston, SC 29425-2221
| | - Phillip C. Moschella
- Cardiology Division of the Department of Medicine, Gazes Cardiac Research Institute, Medical University of South Carolina, Charleston, SC 29425-2221
| | - Kavin Panneerselvam
- Cardiology Division of the Department of Medicine, Gazes Cardiac Research Institute, Medical University of South Carolina, Charleston, SC 29425-2221
| | - Sundaravadivel Balasubramanian
- Cardiology Division of the Department of Medicine, Gazes Cardiac Research Institute, Medical University of South Carolina, Charleston, SC 29425-2221
| | - Dhandapani Kuppuswamy
- Cardiology Division of the Department of Medicine, Gazes Cardiac Research Institute, Medical University of South Carolina, Charleston, SC 29425-2221
- Corresponding author at: Gazes Cardiac Research Institute, Medical University of South Carolina, 114 Doughty Street, Charleston, South Carolina 29425-2221 Telephone: 843-876 5067; Fax: 843-876 5068;
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60
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Stoppel WL, Kaplan DL, Black LD. Electrical and mechanical stimulation of cardiac cells and tissue constructs. Adv Drug Deliv Rev 2016; 96:135-55. [PMID: 26232525 DOI: 10.1016/j.addr.2015.07.009] [Citation(s) in RCA: 148] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2015] [Revised: 07/16/2015] [Accepted: 07/25/2015] [Indexed: 12/19/2022]
Abstract
The field of cardiac tissue engineering has made significant strides over the last few decades, highlighted by the development of human cell derived constructs that have shown increasing functional maturity over time, particularly using bioreactor systems to stimulate the constructs. However, the functionality of these tissues is still unable to match that of native cardiac tissue and many of the stem-cell derived cardiomyocytes display an immature, fetal like phenotype. In this review, we seek to elucidate the biological underpinnings of both mechanical and electrical signaling, as identified via studies related to cardiac development and those related to an evaluation of cardiac disease progression. Next, we review the different types of bioreactors developed to individually deliver electrical and mechanical stimulation to cardiomyocytes in vitro in both two and three-dimensional tissue platforms. Reactors and culture conditions that promote functional cardiomyogenesis in vitro are also highlighted. We then cover the more recent work in the development of bioreactors that combine electrical and mechanical stimulation in order to mimic the complex signaling environment present in vivo. We conclude by offering our impressions on the important next steps for physiologically relevant mechanical and electrical stimulation of cardiac cells and engineered tissue in vitro.
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61
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Schmid E, Neef S, Berlin C, Tomasovic A, Kahlert K, Nordbeck P, Deiss K, Denzinger S, Herrmann S, Wettwer E, Weidendorfer M, Becker D, Schäfer F, Wagner N, Ergün S, Schmitt JP, Katus HA, Weidemann F, Ravens U, Maack C, Hein L, Ertl G, Müller OJ, Maier LS, Lohse MJ, Lorenz K. Cardiac RKIP induces a beneficial β-adrenoceptor-dependent positive inotropy. Nat Med 2015; 21:1298-306. [PMID: 26479924 DOI: 10.1038/nm.3972] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2015] [Accepted: 09/12/2015] [Indexed: 01/08/2023]
Abstract
In heart failure therapy, it is generally assumed that attempts to produce a long-term increase in cardiac contractile force are almost always accompanied by structural and functional damage. Here we show that modest overexpression of the Raf kinase inhibitor protein (RKIP), encoded by Pebp1 in mice, produces a well-tolerated, persistent increase in cardiac contractility that is mediated by the β1-adrenoceptor (β1AR). This result is unexpected, as β1AR activation, a major driver of cardiac contractility, usually has long-term adverse effects. RKIP overexpression achieves this tolerance via simultaneous activation of the β2AR subtype. Analogously, RKIP deficiency exaggerates pressure overload-induced cardiac failure. We find that RKIP expression is upregulated in mouse and human heart failure, indicative of an adaptive role for RKIP. Pebp1 gene transfer in a mouse model of heart failure has beneficial effects, suggesting a new therapeutic strategy for heart failure therapy.
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Affiliation(s)
- Evelyn Schmid
- Department of Pharmacology, Institute of Pharmacology and Toxicology, Würzburg, Germany
| | - Stefan Neef
- Department of Internal Medicine II, University Hospital Regensburg, Regensburg, Germany
| | - Christopher Berlin
- Department of Pharmacology, Institute of Pharmacology and Toxicology, Würzburg, Germany
| | - Angela Tomasovic
- Department of Pharmacology, Institute of Pharmacology and Toxicology, Würzburg, Germany
| | - Katrin Kahlert
- Department of Pharmacology, Institute of Pharmacology and Toxicology, Würzburg, Germany
| | - Peter Nordbeck
- Comprehensive Heart Failure Center, Würzburg, Germany.,Department of Internal Medicine I, University of Würzburg, Würzburg, Germany
| | - Katharina Deiss
- Department of Pharmacology, Institute of Pharmacology and Toxicology, Würzburg, Germany
| | - Sabrina Denzinger
- Department of Pharmacology, Institute of Pharmacology and Toxicology, Würzburg, Germany
| | - Sebastian Herrmann
- Comprehensive Heart Failure Center, Würzburg, Germany.,Department of Internal Medicine I, University of Würzburg, Würzburg, Germany
| | - Erich Wettwer
- Department of Pharmacology and Toxicology, Medical Faculty Gustav Carus, Dresden University of Technology, Dresden, Germany
| | - Markus Weidendorfer
- Department of Pharmacology, Institute of Pharmacology and Toxicology, Würzburg, Germany
| | - Daniel Becker
- Department of Pharmacology, Institute of Pharmacology and Toxicology, Würzburg, Germany
| | - Florian Schäfer
- Department of Pharmacology, Institute of Pharmacology and Toxicology, Würzburg, Germany
| | - Nicole Wagner
- Institute of Anatomy and Cell Biology, Würzburg, Germany
| | - Süleyman Ergün
- Institute of Anatomy and Cell Biology, Würzburg, Germany
| | - Joachim P Schmitt
- Department of Pharmacology, Institute of Pharmacology and Toxicology, Würzburg, Germany
| | - Hugo A Katus
- Department of Internal Medicine III, Heidelberg University Hospital, Heidelberg, Germany.,German Centre for Cardiovascular Research, Heidelberg University Hospital, Heidelberg, Germany
| | - Frank Weidemann
- Comprehensive Heart Failure Center, Würzburg, Germany.,Department of Internal Medicine I, University of Würzburg, Würzburg, Germany
| | - Ursula Ravens
- Department of Pharmacology and Toxicology, Medical Faculty Gustav Carus, Dresden University of Technology, Dresden, Germany
| | - Christoph Maack
- Clinic for Internal Medicine III, Saarland University Hospital, Homburg, Germany
| | - Lutz Hein
- Institute of Experimental and Clinical Pharmacology and Toxicology, Freiburg, Germany.,Centre for Biological Signalling Studies (BIOSS), University of Freiburg, Freiburg, Germany
| | - Georg Ertl
- Comprehensive Heart Failure Center, Würzburg, Germany.,Department of Internal Medicine I, University of Würzburg, Würzburg, Germany
| | - Oliver J Müller
- Department of Internal Medicine III, Heidelberg University Hospital, Heidelberg, Germany.,German Centre for Cardiovascular Research, Heidelberg University Hospital, Heidelberg, Germany
| | - Lars S Maier
- Department of Internal Medicine II, University Hospital Regensburg, Regensburg, Germany
| | - Martin J Lohse
- Department of Pharmacology, Institute of Pharmacology and Toxicology, Würzburg, Germany.,Comprehensive Heart Failure Center, Würzburg, Germany
| | - Kristina Lorenz
- Department of Pharmacology, Institute of Pharmacology and Toxicology, Würzburg, Germany.,Comprehensive Heart Failure Center, Würzburg, Germany
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62
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Li W, Wang N, Li M, Gong H, Liao X, Yang X, Zhang T. Protein kinase Cα inhibits myocardin-induced cardiomyocyte hypertrophy through the promotion of myocardin phosphorylation. Acta Biochim Biophys Sin (Shanghai) 2015. [PMID: 26206583 DOI: 10.1093/abbs/gmv067] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Myocardin plays a key role in the development of cardiac hypertrophy. However, the upstream signals that control the stability and transactivity of myocardin remain to be fully understood. The expression of protein kinase Cα (PKCα) also induces cardiac hypertrophy. An essential downstream molecule of PKCα, extracellular signal-regulated kinase 1/2, was reported to negatively regulate the activities of myocardin. But, the effect of cooperation between PKCα and myocardin and the potential molecular mechanism by which PKCα regulates myocardin-mediated cardiac hypertrophy are unclear. In this study, a luciferase assay was performed using H9C2 cells transfected with expression plasmids for PKCα and myocardin. Surprisingly, the results showed that PKCα inhibited the transcriptional activity of myocardin. PKCα inhibited myocardin-induced cardiomyocyte hypertrophy, demonstrated by the decrease in cell surface area and fetal gene expression, in cardiomyocyte cells overexpressing PKCα and myocardin. The potential mechanism underlying the inhibition effect of PKCα on the function of myocardin is further explored. PKCα directly promoted the basal phosphorylation of endogenous myocardin at serine and threonine residues. In myocardin-overexpressing cardiomyocyte cells, PKCα induced the excessive phosphorylation of myocardin, resulting in the degradation of myocardin and a transcriptional suppression of hypertrophic genes. These results demonstrated that PKCα inhibits myocardin-induced cardiomyocyte hypertrophy through the promotion of myocardin phosphorylation.
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Affiliation(s)
- Weizong Li
- Key Laboratory of Industrial Microbiology, Ministry of Education and Tianjin City, College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, China
| | - Nan Wang
- Key Laboratory of Industrial Microbiology, Ministry of Education and Tianjin City, College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, China
| | - Man Li
- Key Laboratory of Industrial Microbiology, Ministry of Education and Tianjin City, College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, China
| | - Huiqin Gong
- Key Laboratory of Industrial Microbiology, Ministry of Education and Tianjin City, College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, China
| | - Xinghua Liao
- Key Laboratory of Industrial Microbiology, Ministry of Education and Tianjin City, College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, China Department of Biochemistry, Medical College, Wuhan University of Science and Technology, Wuhan 430081, China
| | - Xiaolong Yang
- Key Laboratory of Industrial Microbiology, Ministry of Education and Tianjin City, College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, China
| | - Tongcun Zhang
- Key Laboratory of Industrial Microbiology, Ministry of Education and Tianjin City, College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, China Department of Biochemistry, Medical College, Wuhan University of Science and Technology, Wuhan 430081, China
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63
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Koczor CA, Jiao Z, Fields E, Russ R, Ludaway T, Lewis W. AZT-induced mitochondrial toxicity: an epigenetic paradigm for dysregulation of gene expression through mitochondrial oxidative stress. Physiol Genomics 2015. [PMID: 26199398 DOI: 10.1152/physiolgenomics.00045.2015] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Mitochondrial dysfunction causes oxidative stress and cardiomyopathy. Oxidative stress also is a side effect of dideoxynucleoside antiretrovirals (NRTI) and is observed in NRTI-induced cardiomyopathy. We show here that treatment with the NRTI AZT {1-[(2R,4S,5S)-4-azido-5-(hydroxymethyl)oxolan-2-yl]-5-methylpyrimidine-2,4-dione} modulates cardiac gene expression epigenetically through production of mitochondrially derived reactive oxygen species. Transgenic mice with ubiquitous expression of mitochondrially targeted catalase (MCAT) and C57Bl/6 wild-type mice littermates (WT) were administered AZT (0.22 mg/day po, 35 days), and cardiac DNA and mRNA were isolated. In AZT-treated WT, 95 cardiac genes were differentially expressed compared with vehicle-treated WTs. When MCAT mice were treated with AZT, each of those 95 genes reverted toward the expression of vehicle-treated WTs. In AZT-treated WT hearts, Mthfr [5,10-methylenetetrahydrofolate reductase; a critical enzyme in synthesis of methionine cycle intermediates including S-adenosylmethionine (SAM)], was overexpressed. Steady-state abundance of SAM in cardiac extracts from AZT-treated MCAT mice increased 60% above that of vehicle-treated MCAT. No such change occurred in WT. AZT caused hypermethylation (47%) and hypomethylation (53%) of differentially methylated DNA regions in WT cardiac DNA. AZT-treated MCAT heart DNA exhibited greater hypermethylation (91%) and less hypomethylation (9%) compared with vehicle-treated MCAT controls. The gene encoding protein kinase C-α displayed multifocal epigenetic regulation caused by oxidative stress. Results show that mitochondrially derived oxidative stress in the heart hinders cardiac DNA methylation, alters steady-state abundance of SAM, alters cardiac gene expression, and promotes characteristic pathophysiological changes of cardiomyopathy. This mechanism for NRTI toxicity offers insight into long-term side effects from these commonly used antiviral agents.
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Affiliation(s)
| | - Zhe Jiao
- Department of Pathology, Emory University, Atlanta, Georgia
| | - Earl Fields
- Department of Pathology, Emory University, Atlanta, Georgia
| | - Rodney Russ
- Department of Pathology, Emory University, Atlanta, Georgia
| | - Tomika Ludaway
- Department of Pathology, Emory University, Atlanta, Georgia
| | - William Lewis
- Department of Pathology, Emory University, Atlanta, Georgia
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64
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Song M, Matkovich SJ, Zhang Y, Hammer DJ, Dorn GW. Combined cardiomyocyte PKCδ and PKCε gene deletion uncovers their central role in restraining developmental and reactive heart growth. Sci Signal 2015; 8:ra39. [PMID: 25900833 DOI: 10.1126/scisignal.aaa1855] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Cell growth is orchestrated by changes in gene expression that respond to developmental and environmental cues. Among the signaling pathways that direct growth are enzymes of the protein kinase C (PKC) family, which are ubiquitous proteins belonging to three distinct subclasses: conventional PKCs, novel PKCs, and atypical PKCs. Functional overlap makes determining the physiological actions of different PKC isoforms difficult. We showed that two novel PKC isoforms, PKCδ and PKCε, redundantly govern stress-reactive and developmental heart growth by modulating the expression of cardiac genes central to stress-activated protein kinase and periostin signaling. Mice with combined postnatal cardiomyocyte-specific genetic ablation of PKCδ and germline deletion of PKCε (DCKO) had normally sized hearts, but their hearts had transcriptional changes typical of pathological hypertrophy. Cardiac hypertrophy and dysfunction induced by hemodynamic overloading were greater in DCKO mice than in mice with a single deletion of either PKCδ or PKCε. Furthermore, gene expression analysis of the hearts of DCKO mice revealed transcriptional derepression of the genes encoding the kinase ERK (extracellular signal-regulated kinase) and periostin. Mice with combined embryonic ablation of PKCδ and PKCε showed enhanced growth and cardiomyocyte hyperplasia that induced pathological ventricular stiffening and early lethality, phenotypes absent in mice with a single deletion of PKCδ or PKCε. Our results indicate that novel PKCs provide retrograde feedback inhibition of growth signaling pathways central to cardiac development and stress adaptation. These growth-suppressing effects of novel PKCs have implications for therapeutic inhibition of PKCs in cancer, heart, and other diseases.
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Affiliation(s)
- Moshi Song
- Center for Pharmacogenomics and Division of Cardiology, Department of Internal Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Scot J Matkovich
- Center for Pharmacogenomics and Division of Cardiology, Department of Internal Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Yan Zhang
- Center for Pharmacogenomics and Division of Cardiology, Department of Internal Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Daniel J Hammer
- Center for Pharmacogenomics and Division of Cardiology, Department of Internal Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Gerald W Dorn
- Center for Pharmacogenomics and Division of Cardiology, Department of Internal Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA.
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Zhao T, Zhao W, Meng W, Liu C, Chen Y, Gerling IC, Weber KT, Bhattacharya SK, Kumar R, Sun Y. VEGF-C/VEGFR-3 pathway promotes myocyte hypertrophy and survival in the infarcted myocardium. Am J Transl Res 2015; 7:697-709. [PMID: 26064438 PMCID: PMC4455345] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2014] [Accepted: 04/11/2015] [Indexed: 06/04/2023]
Abstract
BACKGROUND Numerous studies have shown that in addition to angio/lymphangiogenesis, the VEGF family is involved in other cellular actions. We have recently reported that enhanced VEGF-C and VEGFR-3 in the infarcted rat myocardium, suggesting the paracrine/autocrine function of VEGF-C on cardiac remodeling. The current study was designed to test the hypothesis that VEGF-C regulates cardiomyocyte growth and survival in the infarcted myocardium. METHODS AND RESULTS Gene profiling and VEGFR-3 expression of cardiomyocytes were assessed by laser capture microdissection/microarray and immunohistochemistry in the normal and infarcted myocardium. The effect of VEGF-C on myocyte hypertrophy and apoptosis during normoxia and hypoxia was detected by RT-PCR and western blotting in cultured rat neonatal cardiomyocytes. VEGFR-3 was minimally expressed in cardiomyocytes of the normal and noninfarcted myocardium, while markedly elevated in the surviving cardiomyocytes of the infarcted myocardium and border zone. Genes altered in the surviving cardiomyocytes were associated with the networks regulating cellular growth and survival. VEGF-C significantly increased the expression of atrial natriuretic factor (ANP), brain natriuretic factor (BNP), and β-myosin heavy chain (MHC), markers of hypertrophy, in neonatal cardiomyocytes. Hypoxia caused neonatal cardiomyocyte atrophy, which was prevented by VEGF-C treatment. Hypoxia significantly enhanced apoptotic mediators, including cleaved caspase 3, 8, and 9, and Bax in neonatal cardiomyocytes, which were abolished by VEGF-C treatment. CONCLUSION Our findings indicate that VEGF-C/VEGFR-3 pathway exerts a beneficial role in the infarcted myocardium by promoting compensatory cardiomyocyte hypertrophy and survival.
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Affiliation(s)
- Tieqiang Zhao
- Division of Cardiovascular Diseases, Department of Medicine, University of Tennessee Health Science CenterMemphis, TN 38163, USA
| | - Wenyuan Zhao
- Division of Cardiovascular Diseases, Department of Medicine, University of Tennessee Health Science CenterMemphis, TN 38163, USA
| | - Weixin Meng
- Division of Cardiovascular Diseases, Department of Medicine, University of Tennessee Health Science CenterMemphis, TN 38163, USA
| | - Chang Liu
- Division of Cardiovascular Diseases, Department of Medicine, University of Tennessee Health Science CenterMemphis, TN 38163, USA
| | - Yuanjian Chen
- Division of Cardiovascular Diseases, Department of Medicine, University of Tennessee Health Science CenterMemphis, TN 38163, USA
| | - Ivan C Gerling
- Division of Endocrinology, Department of Medicine, University of Tennessee Health Science CenterMemphis, TN 38163, USA
| | - Karl T Weber
- Division of Cardiovascular Diseases, Department of Medicine, University of Tennessee Health Science CenterMemphis, TN 38163, USA
| | - Syamal K Bhattacharya
- Division of Cardiovascular Diseases, Department of Medicine, University of Tennessee Health Science CenterMemphis, TN 38163, USA
| | - Rahul Kumar
- Division of Cardiovascular Diseases, Department of Medicine, University of Tennessee Health Science CenterMemphis, TN 38163, USA
| | - Yao Sun
- Division of Cardiovascular Diseases, Department of Medicine, University of Tennessee Health Science CenterMemphis, TN 38163, USA
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Lu XL, Tong YF, Liu Y, Xu YL, Yang H, Zhang GY, Li XH, Zhang HG. Gαq protein carboxyl terminus imitation polypeptide GCIP-27 improves cardiac function in chronic heart failure rats. PLoS One 2015; 10:e0121007. [PMID: 25822412 PMCID: PMC4379177 DOI: 10.1371/journal.pone.0121007] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2014] [Accepted: 02/03/2015] [Indexed: 11/24/2022] Open
Abstract
Background Gαq protein carboxyl terminus imitation polypeptide (GCIP)-27 has been shown to alleviate pathological cardiomyocyte hypertrophy induced by various factors. Pathological cardiac hypertrophy increases the morbidity and mortality of cardiovascular diseases while it compensates for poor heart function. This study was designed to investigate the effects of GCIP-27 on heart function in rats with heart failure induced by doxorubicin. Methods and Results Forty-eight rats were randomly divided into the following six groups receiving vehicle (control), doxorubicin (Dox), losartan (6 mg/kg, i.g.) and three doses of GCIP-27 (10, 30, 90 μg/kg; i.p., bid), respectively. Heart failure was induced by Dox, which was administered at a 20 mg/kg cumulative dose. After 10 weeks of treatment, we observed that GCIP-27 (30, 90 μg/kg) significantly increased ejection fraction, fraction shortening, stroke volume and sarcoplasmic reticulum Ca2+ ATPase activity of Dox-treated hearts. Additionally, GCIP-27 decreased myocardial injury, heart weight index and left ventricular weight index, fibrosis and serum cardiac troponin-I concentration in Dox-treated mice. Immunohistochemistry, western blotting and real-time PCR experiments indicated that GCIP-27 (10–90 μg/kg) could markedly upregulate the protein expression of myocardial α-myosin heavy chain (MHC), Bcl-2, protein kinase C (PKC) ε and phosphorylated extracellular signal-regulated kinase (p-ERK) 1/2 as well as the mRNA expression of α-MHC, but downregulated the expression of β-MHC, Bax and PKC βII, and the mRNA expression levels of β-MHC in Dox-treated mice. It was also found that GCIP-27 (30, 90 μg/L) decreased cell size and protein content of cardiomyocytes significantly in vitro by comparison of Dox group. Conclusions GCIP-27 could effectively ameliorate heart failure development induced by Dox. PKC–ERK1/2 signaling might represent the underlying mechanism of the beneficial effects of GCIP-27.
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Affiliation(s)
- Xiao Lan Lu
- Department of Pharmacology, College of Pharmacy, Third Military Medical University, Chongqing 400038, China
- Department of Clinical Laboratory, First Affiliated Hospital of North Sichuan Medical College, Sichuan Nanchong 637000, China
| | - Yang Fei Tong
- Department of Pharmacology, College of Pharmacy, Third Military Medical University, Chongqing 400038, China
| | - Ya Liu
- Institute of Materia Medica and Department of Pharmaceutics, College of Pharmacy, Third Military Medical University, Chongqing 40038, China
| | - Ya Li Xu
- Department of Ultrasound, Second Affiliated Hospital, Third Military Medical University, Chongqing 400037, China
| | - Hua Yang
- Department of Pharmacology, College of Pharmacy, Third Military Medical University, Chongqing 400038, China
| | - Guo Yuan Zhang
- Department of Clinical Laboratory, First Affiliated Hospital of North Sichuan Medical College, Sichuan Nanchong 637000, China
| | - Xiao-Hui Li
- Institute of Materia Medica and Department of Pharmaceutics, College of Pharmacy, Third Military Medical University, Chongqing 40038, China
| | - Hai-Gang Zhang
- Department of Pharmacology, College of Pharmacy, Third Military Medical University, Chongqing 400038, China
- * E-mail:
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Tham YK, Bernardo BC, Ooi JYY, Weeks KL, McMullen JR. Pathophysiology of cardiac hypertrophy and heart failure: signaling pathways and novel therapeutic targets. Arch Toxicol 2015; 89:1401-38. [DOI: 10.1007/s00204-015-1477-x] [Citation(s) in RCA: 371] [Impact Index Per Article: 41.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2015] [Accepted: 02/09/2015] [Indexed: 12/18/2022]
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Song X, Qian X, Shen M, Jiang R, Wagner MB, Ding G, Chen G, Shen B. Protein kinase C promotes cardiac fibrosis and heart failure by modulating galectin-3 expression. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2015; 1853:513-21. [DOI: 10.1016/j.bbamcr.2014.12.001] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2014] [Revised: 11/22/2014] [Accepted: 12/01/2014] [Indexed: 12/14/2022]
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New vis-tas in lactosylceramide research. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2015; 842:127-38. [PMID: 25408340 DOI: 10.1007/978-3-319-11280-0_8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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Basson MD, Zeng B, Downey C, Sirivelu MP, Tepe JJ. Increased extracellular pressure stimulates tumor proliferation by a mechanosensitive calcium channel and PKC-β. Mol Oncol 2014; 9:513-26. [PMID: 25454347 DOI: 10.1016/j.molonc.2014.10.008] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2014] [Revised: 10/17/2014] [Accepted: 10/20/2014] [Indexed: 01/31/2023] Open
Abstract
Large tumors exhibit high interstitial pressure heightened by growth against the constraining stroma. Such pressures could stimulate tumor proliferation via a mechanosensitive ion channel. We studied the effects of 0-80 mmHg increased extracellular pressure for 24 h on proliferation of SW620, Caco-2, and CT-26 colon; MCF-7 breast; and MLL and PC3 prostate cancer cells, and delineated its mechanism in SW620 cells with specific inhibitors and siRNA. Finally, we compared NF-kB, phospho-IkB and cyclin D1 immunoreactivity in the high pressure centers and low pressure peripheries of human tumors. Pressure-stimulated proliferation in all cells. Pressure-driven SW620 proliferation required calcium influx via the T-type Ca(2+) channel Cav3.3, which stimulated PKC-β to invoke the IKK-IkB-NF-kB pathway to increase proliferation and S-phase fraction. The mitotic index and immunoreactivity of NF-kB, phospho-IkB, and cyclin D1 in the center of 28 large human colon, lung, and head and neck tumors exceeded that in tumor peripheries. Extracellular pressure increases [Ca(2+)]i via Cav3.3, driving a PKC-β- IKK- IkB-NF-kB pathway that stimulates cancer cell proliferation. Rapid proliferation in large stiff tumors may increase intratumoral pressure, activating this pathway to stimulate further proliferation in a feedback cycle that potentiates tumor growth. Targeting this pathway may inhibit proliferation in large unresectable tumors.
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Affiliation(s)
- Marc D Basson
- Department of Surgery, Michigan State University College of Human Medicine, 1200 E Michigan Ave, Lansing Charter Township, MI 48912, USA.
| | - Bixi Zeng
- Department of Surgery, Michigan State University College of Human Medicine, 1200 E Michigan Ave, Lansing Charter Township, MI 48912, USA
| | - Christina Downey
- Department of Surgery, Michigan State University College of Human Medicine, 1200 E Michigan Ave, Lansing Charter Township, MI 48912, USA
| | - Madhu P Sirivelu
- Department of Surgery, Michigan State University College of Human Medicine, 1200 E Michigan Ave, Lansing Charter Township, MI 48912, USA
| | - Jetze J Tepe
- Department of Pharmacology, Michigan State University, 1355 Bogue Street, B440 Life Sciences Building, East Lansing, MI 48824, USA
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Macías A, de la Cruz A, Prieto A, Peraza DA, Tamkun MM, González T, Valenzuela C. PKC inhibition results in a Kv 1.5 + Kv β1.3 pharmacology closer to Kv 1.5 channels. Br J Pharmacol 2014; 171:4914-26. [PMID: 24946104 DOI: 10.1111/bph.12822] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2013] [Revised: 05/27/2014] [Accepted: 06/05/2014] [Indexed: 01/04/2023] Open
Abstract
BACKGROUND AND PURPOSE The Kv β1.3 subunit modifies the gating and pharmacology of Kv 1.5 channels in a PKC-dependent manner, decreasing channel sensitivity to bupivacaine- and quinidine-mediated blockade. Cardiac Kv 1.5 channels associate with receptor for activated C kinase 1 (RACK1), the Kv β1.3 subunit and different PKC isoforms, resulting in the formation of a functional channelosome. The aim of the present study was to investigate the effects of PKC inhibition on bupivacaine and quinidine block of Kv 1.5 + Kv β1.3 channels. EXPERIMENTAL APPROACH HEK293 cells were transfected with Kv 1.5 + Kv β1.3 channels, and currents were recorded using the whole-cell configuration of the patch-clamp technique. PKC inhibition was achieved by incubating the cells with either calphostin C or bisindolylmaleimide II and the effects of bupivacaine and quinidine were analysed. KEY RESULTS The voltage-dependent inactivation of Kv 1.5 + Kv β1.3 channels and their pharmacological behaviour after PKC inhibition with calphostin C were similar to those displayed by Kv 1.5 channels alone. Indeed, the IC50 values for bupivacaine were similar in cells whose PKC was inhibited with calphostin C or bisindolylmaleimide II. Similar results were also observed in the presence of quinidine. CONCLUSIONS AND IMPLICATIONS The finding that the voltage-dependence of inactivation and the pharmacology of Kv 1.5 + Kv β1.3 channels after PKC inhibition resembled that observed in Kv 1.5 channels suggests that both processes are dependent on PKC-mediated phosphorylation. These results may have clinical relevance in diseases that are characterized by alterations in kinase activity.
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Affiliation(s)
- A Macías
- Modelos Experimentales Enfermedades Humanas, Instituto de Investigaciones Biomédicas 'Alberto Sols' (CSIC-UAM), Madrid, Spain
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Differential and conditional activation of PKC-isoforms dictates cardiac adaptation during physiological to pathological hypertrophy. PLoS One 2014; 9:e104711. [PMID: 25116170 PMCID: PMC4130596 DOI: 10.1371/journal.pone.0104711] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2014] [Accepted: 07/11/2014] [Indexed: 02/02/2023] Open
Abstract
A cardiac hypertrophy is defined as an increase in heart mass which may either be beneficial (physiological hypertrophy) or detrimental (pathological hypertrophy). This study was undertaken to establish the role of different protein kinase-C (PKC) isoforms in the regulation of cardiac adaptation during two types of cardiac hypertrophy. Phosphorylation of specific PKC-isoforms and expression of their downstream proteins were studied during physiological and pathological hypertrophy in 24 week male Balb/c mice (Mus musculus) models, by reverse transcriptase-PCR, western blot analysis and M-mode echocardiography for cardiac function analysis. PKC-δ was significantly induced during pathological hypertrophy while PKC-α was exclusively activated during physiological hypertrophy in our study. PKC-δ activation during pathological hypertrophy resulted in cardiomyocyte apoptosis leading to compromised cardiac function and on the other hand, activation of PKC-α during physiological hypertrophy promoted cardiomyocyte growth but down regulated cellular apoptotic load resulting in improved cardiac function. Reversal in PKC-isoform with induced activation of PKC-δ and simultaneous inhibition of phospho-PKC-α resulted in an efficient myocardium to deteriorate considerably resulting in compromised cardiac function during physiological hypertrophy via augmentation of apoptotic and fibrotic load. This is the first report where PKC-α and -δ have been shown to play crucial role in cardiac adaptation during physiological and pathological hypertrophy respectively thereby rendering compromised cardiac function to an otherwise efficient heart by conditional reversal of their activation.
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Deres L, Bartha E, Palfi A, Eros K, Riba A, Lantos J, Kalai T, Hideg K, Sumegi B, Gallyas F, Toth K, Halmosi R. PARP-inhibitor treatment prevents hypertension induced cardiac remodeling by favorable modulation of heat shock proteins, Akt-1/GSK-3β and several PKC isoforms. PLoS One 2014; 9:e102148. [PMID: 25014216 PMCID: PMC4094529 DOI: 10.1371/journal.pone.0102148] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2014] [Accepted: 06/15/2014] [Indexed: 12/20/2022] Open
Abstract
Spontaneously hypertensive rat (SHR) is a suitable model for studies of the complications of hypertension. It is known that activation of poly(ADP-ribose) polymerase enzyme (PARP) plays an important role in the development of postinfarction as well as long-term hypertension induced heart failure. In this study, we examined whether PARP-inhibitor (L-2286) treatment could prevent the development of hypertensive cardiopathy in SHRs. 6-week-old SHR animals were treated with L-2286 (SHR-L group) or placebo (SHR-C group) for 24 weeks. Wistar-Kyoto rats were used as aged-matched, normotensive controls (WKY group). Echocardiography was performed, brain-derived natriuretic peptide (BNP) activity and blood pressure were determined at the end of the study. We detected the extent of fibrotic areas. The amount of heat-shock proteins (Hsps) and the phosphorylation state of Akt-1(Ser473), glycogen synthase kinase (GSK)-3β(Ser9), forkhead transcription factor (FKHR)(Ser256), mitogen activated protein kinases (MAPKs), and protein kinase C (PKC) isoenzymes were monitored. The elevated blood pressure in SHRs was not influenced by PARP-inhibitor treatment. Systolic left ventricular function and BNP activity did not differ among the three groups. L-2286 treatment decreased the marked left ventricular (LV) hypertrophy which was developed in SHRs. Interstitial collagen deposition was also decreased by L-2286 treatment. The phosphorylation of extracellular signal-regulated kinase (ERK)1/2(Thr183-Tyr185), Akt-1(Ser473), GSK-3β(Ser9), FKHR(Ser256), and PKC ε(Ser729) and the level of Hsp90 were increased, while the activity of PKC α/βII(Thr638/641), ζ/λ(410/403) were mitigated by L-2286 administration. We could detect signs of LV hypertrophy without congestive heart failure in SHR groups. This alteration was prevented by PARP inhibition. Our results suggest that PARP-inhibitor treatment has protective effect already in the early stage of hypertensive myocardial remodeling.
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Affiliation(s)
- Laszlo Deres
- First Department of Medicine, Division of Cardiology, University of Pécs, Pécs, Hungary
- Szentagothai Janos Research Center, University of Pécs, Medical School, Pécs, Hungary
| | - Eva Bartha
- First Department of Medicine, Division of Cardiology, University of Pécs, Pécs, Hungary
| | - Anita Palfi
- First Department of Medicine, Division of Cardiology, University of Pécs, Pécs, Hungary
| | - Krisztian Eros
- First Department of Medicine, Division of Cardiology, University of Pécs, Pécs, Hungary
- Szentagothai Janos Research Center, University of Pécs, Medical School, Pécs, Hungary
| | - Adam Riba
- First Department of Medicine, Division of Cardiology, University of Pécs, Pécs, Hungary
- Szentagothai Janos Research Center, University of Pécs, Medical School, Pécs, Hungary
| | - Janos Lantos
- Department of Surgical Research and Techniques, University of Pécs, Pécs, Hungary
| | - Tamas Kalai
- Department of Organic and Medicinal Chemistry, University of Pécs, Pécs, Hungary
| | - Kalman Hideg
- Department of Organic and Medicinal Chemistry, University of Pécs, Pécs, Hungary
| | - Balazs Sumegi
- Szentagothai Janos Research Center, University of Pécs, Medical School, Pécs, Hungary
- Department of Biochemistry and Medical Chemistry, Medical School, University of Pécs, Pécs, Hungary
- MTA-PTE Nuclear-Mitochondrial Interactions Research Group, Pécs, Hungary
| | - Ferenc Gallyas
- Department of Biochemistry and Medical Chemistry, Medical School, University of Pécs, Pécs, Hungary
- MTA-PTE Nuclear-Mitochondrial Interactions Research Group, Pécs, Hungary
| | - Kalman Toth
- First Department of Medicine, Division of Cardiology, University of Pécs, Pécs, Hungary
| | - Robert Halmosi
- First Department of Medicine, Division of Cardiology, University of Pécs, Pécs, Hungary
- Szentagothai Janos Research Center, University of Pécs, Medical School, Pécs, Hungary
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Simultaneous loss of phospholipase Cδ1 and phospholipase Cδ3 causes cardiomyocyte apoptosis and cardiomyopathy. Cell Death Dis 2014; 5:e1215. [PMID: 24810051 PMCID: PMC4047916 DOI: 10.1038/cddis.2014.181] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2013] [Revised: 01/23/2014] [Accepted: 03/26/2014] [Indexed: 11/10/2022]
Abstract
Phospholipase C (PLC) is a key enzyme in phosphoinositide turnover. Among 13 PLC isozymes, PLCδ1 and PLCδ3 share high sequence homology and similar tissue distribution, and are expected to have functional redundancy in many tissues. We previously reported that the simultaneous loss of PLCδ1 and PLCδ3 caused embryonic lethality because of excessive apoptosis and impaired vascularization of the placenta. Prenatal death of PLCδ1/PLCδ3 double-knockout mice hampered our investigation of the roles of these genes in adult animals. Here, we generated PLCδ1/PLCδ3 double-knockout mice that expressed PLCδ1 in extra-embryonic tissues (cDKO mice) to escape embryonic lethality. The cDKO mice were born at the expected Mendelian ratio, which indicated that the simultaneous loss of PLCδ1 and PLCδ3 in the embryo proper did not impair embryonic development. However, half of the cDKO mice died prematurely. In addition, the surviving cDKO mice spontaneously showed cardiac abnormalities, such as increased heart weight/tibial length ratios, impaired cardiac function, cardiac fibrosis, dilation, and hypertrophy. Predating these abnormalities, excessive apoptosis of their cardiomyocytes was observed. In addition, siRNA-mediated simultaneous silencing of PLCδ1 and PLCδ3 increased apoptosis in differentiated-H9c2 cardiomyoblasts. Activation of Akt and protein kinase C (PKC) θ was impaired in the hearts of the cDKO mice. siRNA-mediated simultaneous silencing of PLCδ1 and PLCδ3 also decreased activated Akt and PKCθ in differentiated-H9c2 cardiomyoblasts. These results indicate that PLCδ1 and PLCδ3 are required for cardiomyocyte survival and normal cardiac function.
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Mishra S, Chatterjee S. Lactosylceramide promotes hypertrophy through ROS generation and activation of ERK1/2 in cardiomyocytes. Glycobiology 2014; 24:518-31. [PMID: 24658420 PMCID: PMC4001711 DOI: 10.1093/glycob/cwu020] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Hypertrophy is central to several heart diseases; however, not much is known about the role of glycosphingolipids (GSLs) in this phenotype. Since GSLs have been accorded several physiological functions, we sought to determine whether these compounds affect cardiac hypertrophy. By using a rat cardiomyoblast cell line, H9c2 cells and cultured primary neonatal rat cardiomyocytes, we have determined the effects of GSLs on hypertrophy. Our study comprises (a) measurement of [(3)H]-leucine incorporation into protein, (b) measurement of cell size and morphology by immunofluorescence microscopy and (c) real-time quantitative mRNA expression assay for atrial natriuretic peptide and brain natriuretic peptide. Phenylephrine (PE), a well-established agonist of cardiac hypertrophy, served as a positive control in these studies. Subsequently, mechanistic studies were performed to explore the involvement of various signaling transduction pathways that may contribute to hypertrophy in these cardiomyocytes. We observed that lactosylceramide specifically exerted a concentration- (50-100 µM) and time (48 h)-dependent increase in hypertrophy in cardiomyocytes but not a library of other structurally related GSLs. Further, in cardiomyocytes, LacCer generated reactive oxygen species, stimulated the phosphorylation of p44 mitogen activated protein kinase and protein kinase-C, and enhanced c-jun and c-fos expression, ultimately leading to hypertrophy. In summary, we report here that LacCer specifically induces hypertrophy in cardiomyocytes via an "oxygen-sensitive signal transduction pathway."
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Affiliation(s)
- Sumita Mishra
- Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
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Huynh K, Bernardo BC, McMullen JR, Ritchie RH. Diabetic cardiomyopathy: mechanisms and new treatment strategies targeting antioxidant signaling pathways. Pharmacol Ther 2014; 142:375-415. [PMID: 24462787 DOI: 10.1016/j.pharmthera.2014.01.003] [Citation(s) in RCA: 395] [Impact Index Per Article: 39.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2014] [Accepted: 01/08/2014] [Indexed: 12/14/2022]
Abstract
Cardiovascular disease is the primary cause of morbidity and mortality among the diabetic population. Both experimental and clinical evidence suggest that diabetic subjects are predisposed to a distinct cardiomyopathy, independent of concomitant macro- and microvascular disorders. 'Diabetic cardiomyopathy' is characterized by early impairments in diastolic function, accompanied by the development of cardiomyocyte hypertrophy, myocardial fibrosis and cardiomyocyte apoptosis. The pathophysiology underlying diabetes-induced cardiac damage is complex and multifactorial, with elevated oxidative stress as a key contributor. We now review the current evidence of molecular disturbances present in the diabetic heart, and their role in the development of diabetes-induced impairments in myocardial function and structure. Our focus incorporates both the contribution of increased reactive oxygen species production and reduced antioxidant defenses to diabetic cardiomyopathy, together with modulation of protein signaling pathways and the emerging role of protein O-GlcNAcylation and miRNA dysregulation in the progression of diabetic heart disease. Lastly, we discuss both conventional and novel therapeutic approaches for the treatment of left ventricular dysfunction in diabetic patients, from inhibition of the renin-angiotensin-aldosterone-system, through recent evidence favoring supplementation of endogenous antioxidants for the treatment of diabetic cardiomyopathy. Novel therapeutic strategies, such as gene therapy targeting the phosphoinositide 3-kinase PI3K(p110α) signaling pathway, and miRNA dysregulation, are also reviewed. Targeting redox stress and protective protein signaling pathways may represent a future strategy for combating the ever-increasing incidence of heart failure in the diabetic population.
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Affiliation(s)
- Karina Huynh
- Baker IDI Heart & Diabetes Institute, Melbourne, Australia; Department of Medicine, Monash University, Clayton, Victoria, Australia
| | | | - Julie R McMullen
- Baker IDI Heart & Diabetes Institute, Melbourne, Australia; Department of Medicine, Monash University, Clayton, Victoria, Australia; Department of Physiology, Monash University, Clayton, Victoria, Australia.
| | - Rebecca H Ritchie
- Baker IDI Heart & Diabetes Institute, Melbourne, Australia; Department of Medicine, Monash University, Clayton, Victoria, Australia.
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Somvanshi RK, Zou S, Qiu X, Kumar U. Somatostatin receptor-2 negatively regulates β-adrenergic receptor mediated Ca(2+) dependent signaling pathways in H9c2 cells. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2014; 1843:735-45. [PMID: 24412308 DOI: 10.1016/j.bbamcr.2014.01.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 10/19/2013] [Revised: 12/24/2013] [Accepted: 01/02/2014] [Indexed: 01/06/2023]
Abstract
In the present study, we report that somatostatin receptor 2 (SSTR2) plays a crucial role in modulation of β1AR and β2AR mediated signaling pathways that are associated with increased intracellular Ca(2+) and cardiac complications. In H9c2 cells, SSTR2 colocalizes with β1AR or β2AR in receptor specific manner. SSTR2 selective agonist inhibits isoproterenol and formoterol stimulated cAMP formation and PKA phosphorylation in concentration dependent manner. In the presence of SSTR2 agonist, the expression of PKCα and PKCβ was comparable to the basal condition, however SSTR2 agonist inhibits isoproterenol or formoterol induced PKCα and PKCβ expression, respectively. Furthermore, the activation of SSTR2 not only inhibits calcineurin expression and its activity, but also blocks NFAT dephosphorylation and its nuclear translocation. SSTR2 selective agonist abrogates isoproterenol mediated increase in cell size and protein content (an index of hypertrophy). Taken together, the results described here provide direct evidence in support of cardiac protective role of SSTR2 via modulation of Ca(2+) associated signaling pathways attributed to cardiac hypertrophy.
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Affiliation(s)
- Rishi K Somvanshi
- Faculty of Pharmaceutical Sciences, The University of British Columbia, Vancouver, BC V6T1Z3, Canada
| | - Shenglong Zou
- Faculty of Pharmaceutical Sciences, The University of British Columbia, Vancouver, BC V6T1Z3, Canada
| | - Xiaofan Qiu
- Faculty of Pharmaceutical Sciences, The University of British Columbia, Vancouver, BC V6T1Z3, Canada
| | - Ujendra Kumar
- Faculty of Pharmaceutical Sciences, The University of British Columbia, Vancouver, BC V6T1Z3, Canada.
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O'Connell TD, Jensen BC, Baker AJ, Simpson PC. Cardiac alpha1-adrenergic receptors: novel aspects of expression, signaling mechanisms, physiologic function, and clinical importance. Pharmacol Rev 2013; 66:308-33. [PMID: 24368739 DOI: 10.1124/pr.112.007203] [Citation(s) in RCA: 132] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Adrenergic receptors (AR) are G-protein-coupled receptors (GPCRs) that have a crucial role in cardiac physiology in health and disease. Alpha1-ARs signal through Gαq, and signaling through Gq, for example, by endothelin and angiotensin receptors, is thought to be detrimental to the heart. In contrast, cardiac alpha1-ARs mediate important protective and adaptive functions in the heart, although alpha1-ARs are only a minor fraction of total cardiac ARs. Cardiac alpha1-ARs activate pleiotropic downstream signaling to prevent pathologic remodeling in heart failure. Mechanisms defined in animal and cell models include activation of adaptive hypertrophy, prevention of cardiac myocyte death, augmentation of contractility, and induction of ischemic preconditioning. Surprisingly, at the molecular level, alpha1-ARs localize to and signal at the nucleus in cardiac myocytes, and, unlike most GPCRs, activate "inside-out" signaling to cause cardioprotection. Contrary to past opinion, human cardiac alpha1-AR expression is similar to that in the mouse, where alpha1-AR effects are seen most convincingly in knockout models. Human clinical studies show that alpha1-blockade worsens heart failure in hypertension and does not improve outcomes in heart failure, implying a cardioprotective role for human alpha1-ARs. In summary, these findings identify novel functional and mechanistic aspects of cardiac alpha1-AR function and suggest that activation of cardiac alpha1-AR might be a viable therapeutic strategy in heart failure.
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Affiliation(s)
- Timothy D O'Connell
- VA Medical Center (111-C-8), 4150 Clement St., San Francisco, CA 94121. ; or Dr. Timothy D. O'Connell, E-mail:
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79
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Reuter H, Seuthe K, Korkmaz Y, Grönke S, Hoyer DP, Rottlaender D, Zobel C, Addicks K, Hoyer J, Grimminger P, Brabender J, Wilkie TM, Erdmann E. The G protein Gα11 is essential for hypertrophic signalling in diabetic myocardium. Int J Cardiol 2013; 167:1476-85. [DOI: 10.1016/j.ijcard.2012.04.039] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/01/2011] [Revised: 03/01/2012] [Accepted: 04/08/2012] [Indexed: 11/15/2022]
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80
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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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81
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Sabbatini ME, Williams JA. Cholecystokinin-mediated RhoGDI phosphorylation via PKCα promotes both RhoA and Rac1 signaling. PLoS One 2013; 8:e66029. [PMID: 23776598 PMCID: PMC3679036 DOI: 10.1371/journal.pone.0066029] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2012] [Accepted: 05/07/2013] [Indexed: 01/18/2023] Open
Abstract
RhoA and Rac1 have been implicated in the mechanism of CCK-induced amylase secretion from pancreatic acini. In all cell types studied to date, inactive Rho GTPases are present in the cytosol bound to the guanine nucleotide dissociation inhibitor RhoGDI. Here, we identified the switch mechanism regulating RhoGDI1-Rho GTPase dissociation and RhoA translocation upon CCK stimulation in pancreatic acini. We found that both Gα13 and PKC, independently, regulate CCK-induced RhoA translocation and that the PKC isoform involved is PKCα. Both RhoGDI1 and RhoGDI3, but not RhoGDI2, are expressed in pancreatic acini. Cytosolic RhoA and Rac1 are associated with RhoGDI1, and CCK-stimulated PKCα activation releases the complex. Overexpression of RhoGDI1, by binding RhoA, inhibits its activation, and thereby, CCK-induced apical amylase secretion. RhoA translocation is also inhibited by RhoGDI1. Inactive Rac1 influences CCK-induced RhoA activation by preventing RhoGDI1 from binding RhoA. By mutational analysis we found that CCK-induced PKCα phosphorylation on RhoGDI1 at Ser96 releases RhoA and Rac1 from RhoGDI1 to facilitate Rho GTPases signaling.
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Affiliation(s)
- Maria Eugenia Sabbatini
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, Michigan, United States of America.
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82
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Ham YM, Mahoney SJ. Compensation of the AKT signaling by ERK signaling in transgenic mice hearts overexpressing TRIM72. Exp Cell Res 2013; 319:1451-62. [PMID: 23567182 DOI: 10.1016/j.yexcr.2013.02.016] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2012] [Revised: 02/14/2013] [Accepted: 02/14/2013] [Indexed: 01/15/2023]
Abstract
The AKT and ERK signaling pathways are known to be involved in cell hypertrophy, proliferation, survival and differentiation. Although there is evidence for crosstalk between these two signaling pathways in cellulo, there is less evidence for cross talk in vivo. Here, we show that crosstalk between AKT and ERK signaling in the hearts of TRIM72-overexpressing transgenic mice (TRIM72-Tg) with alpha-MHC promoter regulates and maintains their heart size. TRIM72, a heart- and skeletal muscle-specific protein, downregulates AKT-mTOR signaling via IRS-1 degradation and reduces the size of rat cardiomyocytes and the size of postnatal TRIM72-Tg hearts. TRIM72 expression was upregulated by hypertrophic inducers in cardiomyocytes, while IRS-1 was downregulated by IGF-1. TRIM72 specifically regulated IGF-1-dependent AKT-mTOR signaling, resulting in a reduction of the size of cardiomyocytes. Postnatal TRIM72-Tg hearts were smaller than control-treated hearts with inhibition of AKT-mTOR signaling. However, adult TRIM72-Tg hearts were larger than of control despite the suppression of AKT-mTOR signaling. Activation of ERK, PKC-α, and JNK were observed to be elevated in adult TRIM72-Tg, and these signals were mediated by ET-1 via the ET receptors A and B. Altogether, these results suggest that AKT signaling regulates cardiac hypertrophy in physiological conditions, and ERK signaling compensates for the absence of AKT signaling during TRIM72 overexpression, leading to pathological hypertrophy.
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Affiliation(s)
- Young-Mi Ham
- College of Life Science and Biotechnology, Korea University, Seoul, Republic of Korea.
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83
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Abstract
Protein kinase C (PKC) isoforms have emerged as important regulators of cardiac contraction, hypertrophy, and signaling pathways that influence ischemic/reperfusion injury. This review focuses on newer concepts regarding PKC isoform-specific activation mechanisms and actions that have implications for the development of PKC-targeted therapeutics.
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Affiliation(s)
- Susan F Steinberg
- Department of Pharmacology, Columbia University, New York, New York, USA.
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84
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Soetikno V, Sari FR, Sukumaran V, Lakshmanan AP, Mito S, Harima M, Thandavarayan RA, Suzuki K, Nagata M, Takagi R, Watanabe K. Curcumin prevents diabetic cardiomyopathy in streptozotocin-induced diabetic rats: Possible involvement of PKC–MAPK signaling pathway. Eur J Pharm Sci 2012; 47:604-14. [DOI: 10.1016/j.ejps.2012.04.018] [Citation(s) in RCA: 89] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2011] [Revised: 03/23/2012] [Accepted: 04/21/2012] [Indexed: 10/28/2022]
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85
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Chuan P, Sivaramakrishnan S, Ashley EA, Spudich JA. Cell-intrinsic functional effects of the α-cardiac myosin Arg-403-Gln mutation in familial hypertrophic cardiomyopathy. Biophys J 2012; 102:2782-90. [PMID: 22735528 DOI: 10.1016/j.bpj.2012.04.049] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2011] [Revised: 04/02/2012] [Accepted: 04/13/2012] [Indexed: 01/27/2023] Open
Abstract
Human familial hypertrophic cardiomyopathy is the most common Mendelian cardiovascular disease worldwide. Among the most severe presentations of the disease are those in families heterozygous for the mutation R403Q in β-cardiac myosin. Mice heterozygous for this mutation in the α-cardiac myosin isoform display typical familial hypertrophic cardiomyopathy pathology. Here, we study cardiomyocytes from heterozygous 403/+ mice. The effects of the R403Q mutation on force-generating capabilities and dynamics of cardiomyocytes were investigated using a dual carbon nanofiber technique to measure single-cell parameters. We demonstrate the Frank-Starling effect at the single cardiomyocyte level by showing that cell stretch causes an increase in amplitude of contraction. Mutant 403/+ cardiomyocytes exhibit higher end-diastolic and end-systolic stiffness than +/+ cardiomyocytes, whereas active force generation capabilities remain unchanged. Additionally, 403/+ cardiomyocytes show slowed relaxation dynamics. These phenotypes are consistent with increased end-diastolic and end-systolic chamber elastance, as well as diastolic dysfunction seen at the level of the whole heart. Our results show that these functional effects of the R403Q mutation are cell-intrinsic, a property that may be a general phenomenon in familial hypertrophic cardiomyopathy.
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Affiliation(s)
- Peiying Chuan
- Department of Biochemistry, Stanford University School of Medicine, Stanford, California, USA
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86
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Exercise preconditioning provides early cardioprotection against exhaustive exercise in rats: potential involvement of protein kinase C delta translocation. Mol Cell Biochem 2012; 368:89-102. [PMID: 22648735 DOI: 10.1007/s11010-012-1346-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2012] [Accepted: 05/16/2012] [Indexed: 12/13/2022]
Abstract
The objective of this study was to investigate the early cardioprotective effect of exercise preconditioning (EP) on the exhaustive exercise-induced myocardial injury in rats and the role of protein kinase C delta isoform (PKCδ) in EP. Rats were subjected to run on the treadmill for four periods of 10 min each at 30 m/min with intervening periods of rest of 10 min as an EP protocol. The exhaustive exercise was performed 0.5 h after EP. PKC inhibitor chelerythrine (CHE) was injected before EP. Our results showed that EP markedly attenuated the exhaustive exercise-induced myocardial ischemia/hypoxia, ultrastructural damage, high serum cTnI, and NT-proBNP levels. CHE injection before EP did not abolish the protection of EP. Both exhaustive exercise and EP produced a significant increase in PKCδ and p-PKCδ(Thr507) protein levels in cardiomyocytes. However, the immunostaining of p-PKCδ(Thr507) in EP cardiomyocytes was primarily localized to intercalated disks and nuclei while the exhaustive exercise-induced high level p-PKCδ(Thr507) was mainly distributed in the cytoplasm. Moreover, the high PKCδ and p-PKCδ(Thr507) levels in exhaustive exercise were significantly down-regulated by EP. CHE did not attenuate the expressions of PKCδ and p-PKCδ(Thr507). These results indicate that an appropriate activation and translocation of PKCδ may represent a mechanism whereby EP can exert an early cardioprotection against exhaustive exercise-induced myocardial injury.
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87
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Hwang H, Robinson DA, Stevenson TK, Wu HC, Kampert SE, Pagani FD, Dyke DB, Martin JL, Sadayappan S, Day SM, Westfall MV. PKCβII modulation of myocyte contractile performance. J Mol Cell Cardiol 2012; 53:176-86. [PMID: 22587992 DOI: 10.1016/j.yjmcc.2012.05.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/29/2011] [Revised: 05/03/2012] [Accepted: 05/04/2012] [Indexed: 12/26/2022]
Abstract
Significant up-regulation of the protein kinase Cβ(II) (PKCβ(II)) develops during heart failure and yet divergent functional outcomes are reported in animal models. The goal here is to investigate PKCβ(II) modulation of contractile function and gain insights into downstream targets in adult cardiac myocytes. Increased PKCβ(II) protein expression and phosphorylation developed after gene transfer into adult myocytes while expression remained undetectable in controls. The PKCβ(II) was distributed in a peri-nuclear pattern and this expression resulted in diminished rates and amplitude of shortening and re-lengthening compared to controls and myocytes expressing dominant negative PKCβ(II) (PKCβDN). Similar decreases were observed in the Ca(2+) transient and the Ca(2+) decay rate slowed in response to caffeine in PKCβ(II)-expressing myocytes. Parallel phosphorylation studies indicated PKCβ(II) targets phosphatase activity to reduce phospholamban (PLB) phosphorylation at residue Thr17 (pThr17-PLB). The PKCβ inhibitor, LY379196 (LY) restored pThr17-PLB to control levels. In contrast, myofilament protein phosphorylation was enhanced by PKCβ(II) expression, and individually, LY and the phosphatase inhibitor, calyculin A each failed to block this response. Further work showed PKCβ(II) increased Ca(2+)-activated, calmodulin-dependent kinase IIδ (CaMKIIδ) expression and enhanced both CaMKIIδ and protein kinase D (PKD) phosphorylation. Phosphorylation of both signaling targets also was resistant to acute inhibition by LY. These later results provide evidence PKCβ(II) modulates contractile function via intermediate downstream pathway(s) in cardiac myocytes.
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Affiliation(s)
- Hyosook Hwang
- Dept. of Surgery, Cardiac Surgery Section, University of Michigan, Ann Arbor, MI 48109, USA
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88
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David M, Macías Á, Moreno C, Prieto Á, Martínez-Mármol R, Vicente R, González T, Felipe A, Tamkun MM, Valenzuela C. Protein kinase C (PKC) activity regulates functional effects of Kvβ1.3 subunit on KV1.5 channels: identification of a cardiac Kv1.5 channelosome. J Biol Chem 2012; 287:21416-28. [PMID: 22547057 DOI: 10.1074/jbc.m111.328278] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
K(v)1.5 channels are the primary channels contributing to the ultrarapid outward potassium current (I(Kur)). The regulatory K(v)β1.3 subunit converts K(v)1.5 channels from delayed rectifiers with a modest degree of slow inactivation to channels with both fast and slow inactivation components. Previous studies have shown that inhibition of PKC with calphostin C abolishes the fast inactivation induced by K(v)β1.3. In this study, we investigated the mechanisms underlying this phenomenon using electrophysiological, biochemical, and confocal microscopy approaches. To achieve this, we used HEK293 cells (which lack K(v)β subunits) transiently cotransfected with K(v)1.5+K(v)β1.3 and also rat ventricular and atrial tissue to study native α-β subunit interactions. Immunocytochemistry assays demonstrated that these channel subunits colocalize in control conditions and after calphostin C treatment. Moreover, coimmunoprecipitation studies showed that K(v)1.5 and K(v)β1.3 remain associated after PKC inhibition. After knocking down all PKC isoforms by siRNA or inhibiting PKC with calphostin C, K(v)β1.3-induced fast inactivation at +60 mV was abolished. However, depolarization to +100 mV revealed K(v)β1.3-induced inactivation, indicating that PKC inhibition causes a dramatic positive shift of the inactivation curve. Our results demonstrate that calphostin C-mediated abolishment of fast inactivation is not due to the dissociation of K(v)1.5 and K(v)β1.3. Finally, immunoprecipitation and immunocytochemistry experiments revealed an association between K(v)1.5, K(v)β1.3, the receptor for activated C kinase (RACK1), PKCβI, PKCβII, and PKCθ in HEK293 cells. A very similar K(v)1.5 channelosome was found in rat ventricular tissue but not in atrial tissue.
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Affiliation(s)
- Miren David
- Instituto de Investigaciones Biomédicas, Madrid Consejo Superior de Investigaciones Científicas-Universidad Autónoma de Madrid, C/Arturo Duperier 4, 28029 Madrid, Spain
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89
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Arumugam S, Thandavarayan RA, Veeraveedu PT, Giridharan VV, Soetikno V, Harima M, Suzuki K, Nagata M, Tagaki R, Kodama M, Watanabe K. Involvement of AMPK and MAPK signaling during the progression of experimental autoimmune myocarditis in rats and its blockade using a novel antioxidant. Exp Mol Pathol 2012; 93:183-9. [PMID: 22542793 DOI: 10.1016/j.yexmp.2012.04.012] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2012] [Revised: 03/21/2012] [Accepted: 04/10/2012] [Indexed: 01/05/2023]
Abstract
There are various reports suggesting the role of angiotensin (Ang) receptor blockers, Ang converting enzyme inhibitors, calcium channel blockers, diuretics and antioxidants against the progression of experimental autoimmune myocarditis (EAM) to dilated cardiomyopathy (DCM). Most of them were reported to be effective during this adverse cardiac remodeling. Recently much attention has been paid to studying the involvement of AMP-activated protein kinase (AMPK) and mitogen activated protein kinase (MAPK) in various cardiovascular ailments. AMPK acts as a master sensor of cellular energy balance via maintenance of lipid and glucose metabolism. Evidences also suggest the relation between AMPK and oxidative stress during physiological and pathological myocardial cellular function. Since, it is of interest to identify the roles of AMPK and MAPK during the progression of EAM to DCM and also the effect of edaravone, a novel free radical scavenger, against its progression. For this, we have carried out western blotting, histopathological staining and immunohistochemical analyses to measure the myocardial expressions of AMPK signaling and oxidative stress related parameters in normal and vehicle or edaravone-treated EAM rats, respectively. We identified the myocardial levels of phospho Akt and phosphoinositide 3-kinase, which are the upstream proteins of AMPK and MAPK activation and both were up-regulated in the vehicle-treated rats, whereas candesartan treatment significantly reversed these changes. We have also measured the myocardial levels of p-AMPKα, different isoforms of protein kinase C and MAPK signaling proteins. All of these protein levels were significantly elevated in the hearts of DCM rats whereas edaravone treatment significantly reversed these changes. In viewing these results, we can suggest that along with MAPK, AMPK signaling also plays a crucial role in the progression of EAM and it can be effectively blocked by the treatment with a novel antioxidant, edaravone.
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Affiliation(s)
- Somasundaram Arumugam
- Department of Clinical Pharmacology, Faculty of Pharmaceutical Sciences, Niigata University of Pharmacy and Applied Life Sciences, Niigata City 956-8603, Japan
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90
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Wong MH, Chapin OC, Johnson MD. LPS-stimulated cytokine production in type I cells is modulated by the renin-angiotensin system. Am J Respir Cell Mol Biol 2011; 46:641-50. [PMID: 22205632 DOI: 10.1165/rcmb.2011-0289oc] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
The alveolar epithelium serves as a barrier to the entry of potential respiratory pathogens. Alveolar Type II (TII) cells have immunomodulatory functions, but whether Type I (TI) cells, which comprise approximately 95% of the alveolar epithelium, also play a role in immunity is unknown. Because the renin-angiotensin system (RAS) is emerging as an important mediator of inflammation, and angiotensin-converting enzyme 2 (ACE2), an element of the RAS, has been implicated in lung injury, we hypothesize that TI cells can produce cytokines in response to LPS stimulation, and that this inflammation can be modulated by the RAS. Alveolar TI cells were isolated from adult Sprague-Dawley rat lungs that had been injured with an intratracheal instillation of LPS. PCR was performed to determine whether TI cells expressed transcripts for TNF-α, IL-6, or IL-1β at baseline and after lung injury. Immunocytochemical and protein analysis detected angiotensin II (Ang II) and ACE2, as well as angiotensin Type 1 receptor (AT1R) and Type 2 receptor (AT2R), in TI cells. To separate cell-specific responses, primary TI cells were isolated, cultured, and exposed to LPS, Ang II, or specific inhibitors of AT1R or AT2R. Cytokine production was assayed by ELISA. LPS stimulated the production of all cytokines, whereas ACE2 and losartan, an AT1R inhibitor, blocked elements of the LPS-induced cytokine response. Primary TI cells produce cytokines when treated with LPS, contain important components of the RAS, and can modulate LPS-induced cytokine production via the RAS, suggesting a role for TI cells in the innate immune response of the lung.
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Affiliation(s)
- Mandi H Wong
- San Francisco VA Medical Center, 4150 Clement St., San Francisco, CA 94121, USA
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91
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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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92
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Nakura A, Higuchi C, Yoshida K, Yoshikawa H. PKCα suppresses osteoblastic differentiation. Bone 2011; 48:476-84. [PMID: 20951242 DOI: 10.1016/j.bone.2010.09.238] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/11/2010] [Revised: 09/08/2010] [Accepted: 09/29/2010] [Indexed: 11/30/2022]
Abstract
Protein kinase C (PKC) plays an essential role in cellular signal transduction for mediating a variety of biological functions. There are 11 PKC isoforms and these isoforms are believed to play distinct roles in cells. Although the role of individual isoforms of PKC has been investigated in many fields, little is known about the role of PKC in osteoblastic differentiation. Here, we investigated which isoforms of PKC are involved in osteoblastic differentiation of the mouse preosteoblastic cell line MC3T3-E1. Treatment with Gö6976, an inhibitor of PKCα and PKCβI, increased alkaline phosphatase (ALP) activity as well as gene expression of ALP and Osteocalcin (OCN), and enhanced calcification of the extracellular matrix. Concurrently, osteoblastic cell proliferation decreased at a concentration of 1.0 μM. In contrast, a PKCβ inhibitor, which inhibits PKCβI and PKCβII, did not significantly affect osteoblastic differentiation or cell proliferation. Knockdown of PKCα using MC3T3-E1 cells transfected with siRNA also induced an increase in ALP activity and in gene expression of ALP and OCN. In contrast, overexpression of wild-type PKCα decreased ALP activity and attenuated osteoblastic differentiation markers including ALP and OCN, but promoted cell proliferation. Taken together, our results indicate that PKCα suppresses osteoblastic differentiation, but promotes osteoblastic cell proliferation. These results imply that PKCα may have a pivotal role in cell signaling that modulates the differentiation and proliferation of osteoblasts.
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Affiliation(s)
- Akio Nakura
- Department of Orthopaedic Surgery, Graduate School of Medicine, Osaka University, Suita, Osaka, Japan.
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93
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Pluteanu F, Cribbs LL. Regulation and function of Cav3.1 T-type calcium channels in IGF-I-stimulated pulmonary artery smooth muscle cells. Am J Physiol Cell Physiol 2010; 300:C517-25. [PMID: 21148410 DOI: 10.1152/ajpcell.00107.2010] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Arterial smooth muscle cells enter the cell cycle and proliferate in conditions of disease and injury, leading to adverse vessel remodeling. In the pulmonary vasculature, diverse stimuli cause proliferation of pulmonary artery smooth muscle cells (PASMCs), pulmonary artery remodeling, and the clinical condition of pulmonary hypertension associated with significant health consequences. PASMC proliferation requires extracellular Ca(2+) influx that is intimately linked with intracellular Ca(2+) homeostasis. Among the primary sources of Ca(2+) influx in PASMCs is the low-voltage-activated family of T-type Ca(2+) channels; however, up to now, mechanisms for the action of T-type channels in vascular smooth muscle cell proliferation have not been addressed. The Ca(v)3.1 T-type Ca(2+) channel mRNA is upregulated in cultured PASMCs stimulated to proliferate with insulin-like growth factor-I (IGF-I), and this upregulation depends on phosphatidylinositol 3-kinase/Akt signaling. Multiple stimuli that trigger an acute rise in intracellular Ca(2+) in PASMCs, including IGF-I, also require the expression of Ca(v)3.1 Ca(2+) channels for their action. IGF-I also led to cell cycle initiation and proliferation of PASMCs, and, when expression of the Ca(v)3.1 Ca(2+) channel was knocked down by RNA interference, so were the expression and activation of cyclin D, which are necessary steps for cell cycle progression. These results confirm the importance of T-type Ca(2+) channels in proper progression of the cell cycle in PASMCs stimulated to proliferate by IGF-I and suggest that Ca(2+) entry through Ca(v)3.1 T-type channels in particular interacts with Ca(2+)-dependent steps of the mitogenic signaling cascade as a central component of vascular remodeling in disease.
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Affiliation(s)
- Florentina Pluteanu
- Department of Medicine, Loyola Univ. Chicago, 2160 S. 1 Ave., Maywood, IL 60153, USA
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94
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El-Zaatari M, Zavros Y, Tessier A, Waghray M, Lentz S, Gumucio D, Todisco A, Merchant JL. Intracellular calcium release and protein kinase C activation stimulate sonic hedgehog gene expression during gastric acid secretion. Gastroenterology 2010; 139:2061-2071.e2. [PMID: 20816837 PMCID: PMC2997213 DOI: 10.1053/j.gastro.2010.08.047] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/15/2009] [Revised: 08/21/2010] [Accepted: 08/26/2010] [Indexed: 02/06/2023]
Abstract
BACKGROUND & AIMS Hypochlorhydria during Helicobacter pylori infection inhibits gastric Sonic Hedgehog (Shh) expression. We investigated whether acid-secretory mechanisms regulate Shh gene expression through intracellular calcium (Ca2(+)(i))-dependent protein kinase C (PKC) or cyclic adenosine monophosphate (cAMP)-dependent protein kinase A (PKA) activation. METHODS We blocked Hedgehog signaling by transgenically overexpressing a secreted form of the Hedgehog interacting protein-1, a natural inhibitor of hedgehog ligands, which induced hypochlorhydria. Gadolinium, ethylene glycol-bis(β-aminoethyl ether)-N,N,N',N'-tetraacetic acid (EGTA) + 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid (BAPTA), PKC-overexpressing adenoviruses, and PKC inhibitors were used to modulate Ca(2+)(i)-release, PKC activity, and Shh gene expression in primary gastric cell, organ, and AGS cell line cultures. PKA hyperactivity was induced in the H(+)/K(+)-β-cholera-toxin-overexpressing mice. RESULTS Mice that expressed secreted hedgehog-interacting protein-1 had lower levels of gastric acid (hypochlorhydria), reduced production of somatostatin, and increased gastrin gene expression. Hypochlorhydria in these mice repressed Shh gene expression, similar to the levels obtained with omeprazole treatment of wild-type mice. However, Shh expression also was repressed in the hyperchlorhydric H(+)/K(+)-β-cholera-toxin model with increased cAMP, suggesting that the regulation of Shh was not solely acid-dependent, but pertained to specific acid-stimulatory signaling pathways. Based on previous reports that Ca(2+)(i) release also stimulates acid secretion in parietal cells, we showed that gadolinium-, thapsigargin-, and carbachol-mediated release of Ca(2+)(i) induced Shh expression. Ca(2+)-chelation with BAPTA + EGTA reduced Shh expression. Overexpression of PKC-α, -β, and -δ (but not PKC-ϵ) induced an Shh gene expression. In addition, phorbol esters induced a Shh-regulated reporter gene. CONCLUSIONS Secretagogues that stimulate gastric acid secretion induce Shh gene expression through increased Ca(2+)(i)-release and PKC activation. Shh might be the ligand transducing changes in gastric acidity to the regulation of G-cell secretion of gastrin.
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Affiliation(s)
- Mohamad El-Zaatari
- Department of Internal Medicine-Gastroenterology, University of Michigan, Ann Arbor, MI
| | - Yana Zavros
- Department of Molecular and Cellular Physiology, University of Cincinnati, Cincinnati, OH
| | - Art Tessier
- Department of Internal Medicine-Gastroenterology, University of Michigan, Ann Arbor, MI
| | - Meghna Waghray
- Department of Internal Medicine-Gastroenterology, University of Michigan, Ann Arbor, MI
| | - Steve Lentz
- Michigan Diabetes Research and Training Center, University of Michigan, Ann Arbor, MI
| | - Deborah Gumucio
- Cell and Developmental Biology, University of Michigan, Ann Arbor, MI
| | - Andrea Todisco
- Department of Internal Medicine-Gastroenterology, University of Michigan, Ann Arbor, MI
| | - Juanita L. Merchant
- Department of Internal Medicine-Gastroenterology, University of Michigan, Ann Arbor, MI,Correspondence: Juanita L. Merchant, M.D., Ph.D., 109 Zina Pitcher Place, BSRB, Rm. 2051, Ann Arbor, MI 48109-2200, Phone: (734) 647-2944, Fax: (734) 736-4686,
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95
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Yan L, Huang H, Tang QZ, Zhu LH, Wang L, Liu C, Bian ZY, Li H. Breviscapine protects against cardiac hypertrophy through blocking PKC-alpha-dependent signaling. J Cell Biochem 2010; 109:1158-71. [PMID: 20127712 DOI: 10.1002/jcb.22495] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Breviscapine is a mixture of flavonoid glycosides extracted from the Chinese herbs. Previous studies have shown that breviscapine possesses comprehensive pharmacological functions. However, very little is known about whether breviscapine have protective role on cardiac hypertrophy. The aim of the present study was to determine whether breviscapine attenuates cardiac hypertrophy induced by angiotensin II (Ang II) in cultured neonatal rat cardiac myocytes in vitro and pressure-overload-induced cardiac hypertrophy in mice in vivo. Our data demonstrated that breviscapine (2.5-15 microM) dose-dependently blocked cardiac hypertrophy induced by Ang II (1 microM) in vitro. The results further revealed that breviscapine (50 mg/kg/day) prevented cardiac hypertrophy induced by aortic banding as assessed by heart weight/body weight and lung weight/body weight ratios, echocardiographic parameters, and gene expression of hypertrophic markers. The inhibitory effect of breviscapine on cardiac hypertrophy is mediated by disrupting PKC-alpha-dependent ERK1/2 and PI3K/AKT signaling. Further studies showed that breviscapine inhibited inflammation by blocking NF-kappaB signaling, and attenuated fibrosis and collagen synthesis through abrogating Smad2/3 signaling. Therefore, these findings indicate that breviscapine, which is a potentially safe and inexpensive therapy for clinical use, has protective potential in targeting cardiac hypertrophy and fibrosis through suppression of PKC-alpha-dependent signaling.
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Affiliation(s)
- Ling Yan
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan 430060, PR China
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96
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Yeh CC, Li H, Malhotra D, Turcato S, Nicholas S, Tu R, Zhu BQ, Cha J, Swigart PM, Myagmar BE, Baker AJ, Simpson PC, Mann MJ. Distinctive ERK and p38 signaling in remote and infarcted myocardium during post-MI remodeling in the mouse. J Cell Biochem 2010; 109:1185-91. [PMID: 20186881 DOI: 10.1002/jcb.22498] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Global activation of MAP kinases has been reported in both human and experimental heart failure. Chronic remodeling of the surviving ventricular wall after myocardial infarction (MI) involves both myocyte loss and fibrosis; we hypothesized that this cardiomyopathy involves differential shifts in pro- and anti-apoptotic MAP kinase signaling in cardiac myocyte (CM) and non-myocyte. Cardiomyopathy after coronary artery ligation in mice was characterized by echocardiography, ex vivo Langendorff preparation, histologic analysis and measurements of apoptosis. Phosphorylation (activation) of signaling molecules was analyzed by Western blot, ELISA and immunohistochemistry. Post-MI remodeling involved dramatic changes in the phosphorylation of both stress-activated MAP (SAP) kinase p38 as well as ERK, a known mediator of cell survival, but not of SAP kinase JNK or the anti-apoptotic mediator of PI3K, Akt. Phosphorylation of p38 rose early after MI in the infarct, whereas a more gradual rise in the remote myocardium accompanied a rise in apoptosis in that region. In both areas, ERK phosphorylation was lowest early after MI and rose steadily thereafter, though infarct phosphorylation was consistently higher. Immunostaining of p-ERK localized to fibrotic areas populated primarily by non-myocytes, whereas staining of p38 phosphorylation was stronger in areas of progressive CM apoptosis. Relative segregation of CMs and non-myocytes in different regions of the post-MI myocardium revealed signaling patterns that imply cell type-specific changes in pro- and anti-apoptotic MAP kinase signaling. Prevention of myocyte loss and of LV remodeling after MI may therefore require cell type-specific manipulation of p38 and ERK activation.
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Affiliation(s)
- Che-Chung Yeh
- Division of Cardiothoracic Surgery, University of California, San Francisco VA Medical Center, San Francisco, CA, USA
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97
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Paoletti R, Maffei A, Madaro L, Notte A, Stanganello E, Cifelli G, Carullo P, Molinaro M, Lembo G, Bouché M. Protein kinase Cθ is required for cardiomyocyte survival and cardiac remodeling. Cell Death Dis 2010; 1:e45. [PMID: 21364651 PMCID: PMC3032313 DOI: 10.1038/cddis.2010.24] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Protein kinase Cs (PKCs) constitute a family of serine/threonine kinases, which has distinguished and specific roles in regulating cardiac responses, including those associated with heart failure. We found that the PKCθ isoform is expressed at considerable levels in the cardiac muscle in mouse, and that it is rapidly activated after pressure overload. To investigate the role of PKCθ in cardiac remodeling, we used PKCθ−/− mice. In vivo analyses of PKCθ−/− hearts showed that the lack of PKCθ expression leads to left ventricular dilation and reduced function. Histological analyses showed a reduction in the number of cardiomyocytes, combined with hypertrophy of the remaining cardiomyocytes, cardiac fibrosis, myofibroblast hyper-proliferation and matrix deposition. We also observed p38 and JunK activation, known to promote cell death in response to stress, combined with upregulation of the fetal pattern of gene expression, considered to be a feature of the hemodynamically or metabolically stressed heart. In keeping with these observations, cultured PKCθ−/− cardiomyocytes were less viable than wild-type cardiomyocytes, and, unlike wild-type cardiomyocytes, underwent programmed cell death upon stimulation with α1-adrenergic agonists and hypoxia. Taken together, these results show that PKCθ maintains the correct structure and function of the heart by preventing cardiomyocyte cell death in response to work demand and to neuro-hormonal signals, to which heart cells are continuously exposed.
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Affiliation(s)
- R Paoletti
- Department of Histology and Medical Embryology, Sapienza University of Rome, Rome, Italy
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98
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Characterization of an animal model of postmenopausal cardiac hypertrophy and novel mechanisms responsible for cardiac decompensation using ovariectomized pressure-overloaded rats. Menopause 2010; 17:213-21. [PMID: 19741553 DOI: 10.1097/gme.0b013e3181b57489] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE The development of animal models of cardiovascular disease are critical to define pathophysiological mechanisms and to advance diagnosis and therapy. The lack of a suitable animal model represents a failure to define the mechanisms responsible for postmenopausal myocardial hypertrophy in hypertension and adverse cardiac remodeling. METHODS In this review, we presented a rat model of postmenopausal myocardial hypertrophy, with particular focus on the similarities between the animal model and postmenopausal women regarding myocardial function as well as molecular and subcellular mechanisms. To elucidate the molecular mechanism of left ventricular (LV) hypertrophy and remodeling in postmenopausal women, we analyzed myocardial hypertrophy as well as cardiac function and hypertrophy-related protein expression in ovariectomized (OVX) and pressure overloaded (PO) rats. RESULTS The model is characterized by depletion of serum estrogen and increased heart-to-body weight and lung-to-body weight ratios. Moreover, the OVX-PO rats also show increased mean arterial blood pressure, LV end-diastolic pressure, LV developed pressure, and maximal rates of LV contraction and relaxation compared with the OVX group. Importantly, Akt activity was largely attenuated, and both endothelial nitric oxide synthase expression and activity were markedly reduced in the OVX-PO group. Finally, significant increased mortality was observed in the OVX-PO group after chronic isoproterenol administration. CONCLUSIONS Our results demonstrate that rats subject to OVX are unable to compensate for hypertrophy partly due to impaired Akt-endothelial nitric oxide synthase signaling along with deteriorated heart function and demonstrated increased mortality. In this review, we discussed the mechanisms of cardiac injury, which could play a critical role in postmenopausal hypertrophy, as well as the characteristics of the OVX-PO female rats as a model to test cardioprotective drugs in postmenopausal women.
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99
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Molecular distinction between physiological and pathological cardiac hypertrophy: experimental findings and therapeutic strategies. Pharmacol Ther 2010; 128:191-227. [PMID: 20438756 DOI: 10.1016/j.pharmthera.2010.04.005] [Citation(s) in RCA: 604] [Impact Index Per Article: 43.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Cardiac hypertrophy can be defined as an increase in heart mass. Pathological cardiac hypertrophy (heart growth that occurs in settings of disease, e.g. hypertension) is a key risk factor for heart failure. Pathological hypertrophy is associated with increased interstitial fibrosis, cell death and cardiac dysfunction. In contrast, physiological cardiac hypertrophy (heart growth that occurs in response to chronic exercise training, i.e. the 'athlete's heart') is reversible and is characterized by normal cardiac morphology (i.e. no fibrosis or apoptosis) and normal or enhanced cardiac function. Given that there are clear functional, structural, metabolic and molecular differences between pathological and physiological hypertrophy, a key question in cardiovascular medicine is whether mechanisms responsible for enhancing function of the athlete's heart can be exploited to benefit patients with pathological hypertrophy and heart failure. This review summarizes key experimental findings that have contributed to our understanding of pathological and physiological heart growth. In particular, we focus on signaling pathways that play a causal role in the development of pathological and physiological hypertrophy. We discuss molecular mechanisms associated with features of cardiac hypertrophy, including protein synthesis, sarcomeric organization, fibrosis, cell death and energy metabolism and provide a summary of profiling studies that have examined genes, microRNAs and proteins that are differentially expressed in models of pathological and physiological hypertrophy. How gender and sex hormones affect cardiac hypertrophy is also discussed. Finally, we explore how knowledge of molecular mechanisms underlying pathological and physiological hypertrophy may influence therapeutic strategies for the treatment of cardiovascular disease and heart failure.
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100
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Malhotra R, D'Souza KM, Staron ML, Birukov KG, Bodi I, Akhter SA. G alpha(q)-mediated activation of GRK2 by mechanical stretch in cardiac myocytes: the role of protein kinase C. J Biol Chem 2010; 285:13748-60. [PMID: 20194499 PMCID: PMC2859538 DOI: 10.1074/jbc.m110.109272] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2010] [Revised: 02/25/2010] [Indexed: 01/08/2023] Open
Abstract
G protein-coupled receptor kinase-2 (GRK2) is a critical regulator of beta-adrenergic receptor (beta-AR) signaling and cardiac function. We studied the effects of mechanical stretch, a potent stimulus for cardiac myocyte hypertrophy, on GRK2 activity and beta-AR signaling. To eliminate neurohormonal influences, neonatal rat ventricular myocytes were subjected to cyclical equi-biaxial stretch. A hypertrophic response was confirmed by "fetal" gene up-regulation. GRK2 activity in cardiac myocytes was increased 4.2-fold at 48 h of stretch versus unstretched controls. Adenylyl cyclase activity was blunted in sarcolemmal membranes after stretch, demonstrating beta-AR desensitization. The hypertrophic response to mechanical stretch is mediated primarily through the G alpha(q)-coupled angiotensin II AT(1) receptor leading to activation of protein kinase C (PKC). PKC is known to phosphorylate GRK2 at the N-terminal serine 29 residue, leading to kinase activation. Overexpression of a mini-gene that inhibits receptor-G alpha(q) coupling blunted stretch-induced hypertrophy and GRK2 activation. Short hairpin RNA-mediated knockdown of PKC alpha also significantly attenuated stretch-induced GRK2 activation. Overexpression of a GRK2 mutant (S29A) in cardiac myocytes inhibited phosphorylation of GRK2 by PKC, abolished stretch-induced GRK2 activation, and restored adenylyl cyclase activity. Cardiac-specific activation of PKC alpha in transgenic mice led to impaired beta-agonist-stimulated ventricular function, blunted cyclase activity, and increased GRK2 phosphorylation and activity. Phosphorylation of GRK2 by PKC appears to be the primary mechanism of increased GRK2 activity and impaired beta-AR signaling after mechanical stretch. Cross-talk between hypertrophic signaling at the level of PKC and beta-AR signaling regulated by GRK2 may be an important mechanism in the transition from compensatory ventricular hypertrophy to heart failure.
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MESH Headings
- Animals
- Cells, Cultured
- Enzyme Activation/genetics
- G-Protein-Coupled Receptor Kinase 2/genetics
- G-Protein-Coupled Receptor Kinase 2/metabolism
- GTP-Binding Protein alpha Subunits, Gq-G11/genetics
- GTP-Binding Protein alpha Subunits, Gq-G11/metabolism
- Gene Knockdown Techniques
- Heart Ventricles/enzymology
- Mice
- Mice, Knockout
- Myocytes, Cardiac/enzymology
- Phosphorylation/genetics
- Protein Kinase C-alpha/genetics
- Protein Kinase C-alpha/metabolism
- Rats
- Receptor, Angiotensin, Type 1/genetics
- Receptor, Angiotensin, Type 1/metabolism
- Receptors, Adrenergic, beta/genetics
- Receptors, Adrenergic, beta/metabolism
- Signal Transduction
- Stress, Physiological
- Time Factors
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Affiliation(s)
- Ricky Malhotra
- From the Department of Surgery, Section of Cardiac and Thoracic Surgery, and
| | - Karen M. D'Souza
- From the Department of Surgery, Section of Cardiac and Thoracic Surgery, and
| | - Michelle L. Staron
- From the Department of Surgery, Section of Cardiac and Thoracic Surgery, and
| | - Konstantin G. Birukov
- Department of Medicine, Section of Pulmonary/Critical Care, University of Chicago Medical Center, Chicago, Illinois 60637 and
| | - Ilona Bodi
- the Institute for Molecular Pharmacology and Biophysics, University of Cincinnati, Cincinnati, Ohio 45267
| | - Shahab A. Akhter
- From the Department of Surgery, Section of Cardiac and Thoracic Surgery, and
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