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Subati T, Yang Z, Murphy MB, Stark JM, Trykall DZ, Davies SS, Barnett JV, Murray KT. Isolevuglandins Promote Mitochondrial Dysfunction and Electrophysiologic Abnormalities in Atrial Cardiomyocytes. Cells 2024; 13:483. [PMID: 38534327 DOI: 10.3390/cells13060483] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2023] [Revised: 03/01/2024] [Accepted: 03/02/2024] [Indexed: 03/28/2024] Open
Abstract
Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia, yet the cellular and molecular mechanisms underlying the AF substrate remain unclear. Isolevuglandins (IsoLGs) are highly reactive lipid dicarbonyl products that mediate oxidative stress-related injury. In murine hypertension, the lipid dicarbonyl scavenger 2-hydroxybenzylamine (2-HOBA) reduced IsoLGs and AF susceptibility. We hypothesized that IsoLGs mediate detrimental pathophysiologic effects in atrial cardiomyocytes that promote the AF substrate. Using Seahorse XFp extracellular flux analysis and a luminescence assay, IsoLG exposure suppressed intracellular ATP production in atrial HL-1 cardiomyocytes. IsoLGs caused mitochondrial dysfunction, with reduced mitochondrial membrane potential, increased mitochondrial reactive oxygen species (ROS) with protein carbonylation, and mitochondrial DNA damage. Moreover, they generated cytosolic preamyloid oligomers previously shown to cause similar detrimental effects in atrial cells. In mouse atrial and HL-1 cells, patch clamp experiments demonstrated that IsoLGs rapidly altered action potentials (AP), implying a direct effect independent of oligomer formation by reducing the maximum Phase 0 upstroke slope and shortening AP duration due to ionic current modifications. IsoLG-mediated mitochondrial and electrophysiologic abnormalities were blunted or totally prevented by 2-HOBA. These findings identify IsoLGs as novel mediators of oxidative stress-dependent atrial pathophysiology and support the investigation of dicarbonyl scavengers as a novel therapeutic approach to prevent AF.
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Affiliation(s)
- Tuerdi Subati
- Departments of Medicine and Pharmacology, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - Zhenjiang Yang
- Departments of Medicine and Pharmacology, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - Matthew B Murphy
- Departments of Medicine and Pharmacology, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - Joshua M Stark
- Departments of Medicine and Pharmacology, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - David Z Trykall
- Departments of Medicine and Pharmacology, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - Sean S Davies
- Departments of Medicine and Pharmacology, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - Joey V Barnett
- Departments of Medicine and Pharmacology, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - Katherine T Murray
- Departments of Medicine and Pharmacology, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
- Division of Clinical Pharmacology Room 559, Preston Research Building, Vanderbilt University School of Medicine, 2220 Pierce Avenue, Nashville, TN 37232, USA
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2
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Murphy MB, Yang Z, Subati T, Farber-Eger E, Kim K, Blackwell DJ, Fleming MR, Stark JM, Van Amburg JC, Woodall KK, Van Beusecum JP, Agrawal V, Smart CD, Pitzer A, Atkinson JB, Fogo AB, Bastarache JA, Kirabo A, Wells QS, Madhur MS, Barnett JV, Murray KT. LNK/SH2B3 loss of function increases susceptibility to murine and human atrial fibrillation. Cardiovasc Res 2024:cvae036. [PMID: 38377486 DOI: 10.1093/cvr/cvae036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Revised: 08/31/2023] [Accepted: 10/07/2023] [Indexed: 02/22/2024] Open
Abstract
AIMS The lymphocyte adaptor protein (LNK) is a negative regulator of cytokine and growth factor signaling. The rs3184504 variant in SH2B3 reduces LNK function and is linked to cardiovascular, inflammatory, and hematologic disorders including stroke. In mice, deletion of Lnk causes inflammation and oxidative stress. We hypothesized that Lnk-/- mice are susceptible to atrial fibrillation (AF) and that rs3184504 is associated with AF and AF-related stroke in humans. During inflammation, reactive lipid dicarbonyls are a major component of oxidative injury, and we further hypothesized that these mediators are critical drivers of the AF substrate in Lnk-/- mice. METHODS AND RESULTS Lnk-/- or wild-type (WT) mice were treated with vehicle or 2-hydroxybenzylamine (2-HOBA), a dicarbonyl scavenger, for 3 months. Compared to WT, Lnk-/- mice displayed increased AF duration that was prevented by 2-HOBA. In the Lnk-/- atria, action potentials were prolonged with reduced transient outward K+ current, increased late Na+ current, and reduced peak Na+ current, proarrhythmic effects that were inhibited by 2-HOBA. Mitochondrial dysfunction, especially for complex I, was evident in Lnk-/- atria, while scavenging lipid dicarbonyls prevented this abnormality. Tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) were elevated in Lnk-/- plasma and atrial tissue, respectively, both of which caused electrical and bioenergetic remodeling in vitro. Inhibition of soluble TNF-α prevented electrical remodeling and AF susceptibility, while IL-1β inhibition improved mitochondrial respiration but had no effect on AF susceptibility. In a large database of genotyped patients, rs3184504 was associated with AF, as well as AF-related stroke. CONCLUSIONS These findings identify a novel role for LNK in the pathophysiology of AF in both experimental mice and in humans. Moreover, reactive lipid dicarbonyls are critical to the inflammatory AF substrate in Lnk-/- mice and mediate the proarrhythmic effects of pro-inflammatory cytokines, primarily through electrical remodeling.
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Affiliation(s)
- Matthew B Murphy
- Departments of Medicine, Pharmacology
- Departments of Medicine, Pathology, Microbiology, and Immunology
| | - Zhenjiang Yang
- Departments of Medicine, Pharmacology
- Departments of Medicine, Pathology, Microbiology, and Immunology
| | - Tuerdi Subati
- Departments of Medicine, Pharmacology
- Departments of Medicine, Pathology, Microbiology, and Immunology
| | | | - Kyungsoo Kim
- Departments of Medicine, Pharmacology
- Departments of Medicine, Pathology, Microbiology, and Immunology
| | - Daniel J Blackwell
- Departments of Medicine, Pharmacology
- Departments of Medicine, Pathology, Microbiology, and Immunology
| | | | - Joshua M Stark
- Departments of Medicine, Pharmacology
- Departments of Medicine, Pathology, Microbiology, and Immunology
| | - Joseph C Van Amburg
- Departments of Medicine, Pharmacology
- Departments of Medicine, Pathology, Microbiology, and Immunology
| | - Kaylen K Woodall
- Departments of Medicine, Pharmacology
- Departments of Medicine, Pathology, Microbiology, and Immunology
| | - Justin P Van Beusecum
- Departments of Medicine, Pharmacology
- Departments of Medicine, Pathology, Microbiology, and Immunology
| | | | - Charles D Smart
- Departments of Medicine, Pharmacology
- Departments of Medicine, Pathology, Microbiology, and Immunology
| | - Ashley Pitzer
- Departments of Medicine, Pharmacology
- Departments of Medicine, Pathology, Microbiology, and Immunology
| | | | | | | | - Annet Kirabo
- Departments of Medicine, Pharmacology
- Departments of Medicine, Pathology, Microbiology, and Immunology
| | - Quinn S Wells
- Departments of Medicine, Pharmacology
- Departments of Medicine, Pathology, Microbiology, and Immunology
- Departments of Medicine, Vanderbilt University School of Medicine, Nashville, TN
| | - Meena S Madhur
- Departments of Medicine, Pharmacology
- Departments of Medicine, Pathology, Microbiology, and Immunology
| | - Joey V Barnett
- Departments of Medicine, Pharmacology
- Departments of Medicine, Pathology, Microbiology, and Immunology
| | - Katherine T Murray
- Departments of Medicine, Pharmacology
- Departments of Medicine, Pathology, Microbiology, and Immunology
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3
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Fadaei R, Davies SS. Oxidative modification of HDL by lipid aldehydes impacts HDL function. Arch Biochem Biophys 2022; 730:109397. [PMID: 36116503 PMCID: PMC9670862 DOI: 10.1016/j.abb.2022.109397] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2022] [Accepted: 09/12/2022] [Indexed: 11/21/2022]
Abstract
Reduced levels of high-density lipoprotein (HDL) cholesterol correlate with increased risk for atherosclerotic cardiovascular diseases and HDL performs functions including reverse cholesterol transport, inhibition of lipid peroxidation, and suppression of inflammation, that would appear critical for cardioprotection. However, several large clinical trials utilizing pharmacologic interventions that elevated HDL cholesterol levels failed to provide cardioprotection to at-risk individuals. The reasons for these unexpected results have only recently begun to be elucidated. HDL cholesterol levels and HDL function can be significantly discordant, so that elevating HDL cholesterol levels may not necessarily lead to increased functional capacity, particularly under conditions that cause HDL to become oxidatively modified, resulting in HDL dysfunction. Here we review evidence that oxidative modifications of HDL, including by reactive lipid aldehydes generated by lipid peroxidation, reduce HDL functionality and that dicarbonyl scavengers that protect HDL against lipid aldehyde modification are beneficial in pre-clinical models of atherosclerotic cardiovascular disease.
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Affiliation(s)
- Reza Fadaei
- Sleep Disorders Research Center, Kermanshah University of Medical Sciences, Kermanshah, Iran
| | - Sean S Davies
- Department of Pharmacology, Vanderbilt University, Nashville, TN, USA.
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Fouda MA, Mohamed YF, Fernandez R, Ruben PC. Anti-inflammatory effects of cannabidiol against lipopolysaccharides in cardiac sodium channels. Br J Pharmacol 2022; 179:5259-5272. [PMID: 35906756 DOI: 10.1111/bph.15936] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Revised: 07/13/2022] [Accepted: 07/24/2022] [Indexed: 12/01/2022] Open
Abstract
BACKGROUND Sepsis, caused by a dysregulated host response to infections, can lead to cardiac arrhythmias. However, the mechanisms underlying sepsis-induced inflammation, and how inflammation provokes cardiac arrhythmias, are not well understood. We hypothesized that CBD may ameliorate lipopolysaccharides (LPS)-induced cardiotoxicity via Toll-like receptor 4 (TLR-4) and cardiac sodium channels (Nav1.5). METHODS AND RESULTS We incubated human immune cells (THP-1 macrophages) with LPS for 24 hours, then extracted the THP-1 incubation media. ELISA assay showed that LPS (1 or 5 μg/ml), in a concentration-dependent manner, or MPLA (TLR-4 agonist, 5 μg/ml) stimulated the THP-1 cells to release inflammatory cytokines (TNF-α and IL-6). Prior incubation (4 hours) with cannabidiol (CBD: 5 μM) or C34 (TLR-4 antagonist: 5 μg/ml) inhibited LPS and MPLA-induced release of both IL-6 and TNF-α. Human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CM) were subsequently incubated for 24 hours in the media extracted from THP-1 cells incubated with LPS, MPLA alone, or in combination with CBD or C34. Voltage-clamp experiments showed a right shift in the voltage dependence of Nav1.5 activation, steady state fast inactivation (SSFI), increased persistent current and prolonged in silico action potential duration in hiSPC-CM incubated in the LPS or MPLA-THP-1 media. Co-incubation with CBD or C34 rescued the biophysical dysfunction caused by LPS and MPLA. CONCLUSION Our results suggest that CBD may protect against sepsis-induced inflammation and subsequent arrhythmias through (i) inhibition of the release of inflammatory cytokines, antioxidant and anti-apoptotic effects and/or (ii) direct effect on Nav1.5.
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Affiliation(s)
- Mohamed A Fouda
- Department of Biomedical Physiology and Kinesiology, Simon Fraser University, Burnaby, Canada.,Department of Pharmacology and Toxicology, Alexandria University, Alexandria, Egypt
| | - Yasmine Fathy Mohamed
- Department of Microbiology and Immunology, University of British Columbia, Vancouver, Canada.,Department of Microbiology and Immunology, Alexandria University, Alexandria, Egypt
| | - Rachel Fernandez
- Department of Microbiology and Immunology, University of British Columbia, Vancouver, Canada
| | - Peter C Ruben
- Department of Biomedical Physiology and Kinesiology, Simon Fraser University, Burnaby, Canada
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5
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Fouda MA, Ghovanloo MR, Ruben PC. Late sodium current: incomplete inactivation triggers seizures, myotonias, arrhythmias, and pain syndromes. J Physiol 2022; 600:2835-2851. [PMID: 35436004 DOI: 10.1113/jp282768] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Accepted: 04/12/2022] [Indexed: 11/08/2022] Open
Abstract
Acquired and inherited dysfunction in voltage-gated sodium channels underlies a wide range of diseases. "In addition to the defects in trafficking and expression, sodium channelopathies are also caused by dysfunction in one or several gating properties, for instance activation or inactivation. Disruption of the channel inactivation leads to the increased late sodium current, which is a common defect in seizure disorders, cardiac arrhythmias skeletal muscle myotonia and pain. An increase in late sodium current leads to repetitive action potential in neurons and skeletal muscles, and prolonged action potential duration in the heart. In this topical review, we compare the effects of late sodium current in brain, heart, skeletal muscle, and peripheral nerves. Abstract figure legend Shows cartoon illustration of general Nav channel transitions between (1) resting, (2) open, and (3) fast inactivated states. Disruption of the inactivation process exacerbates (4) late sodium currents. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Mohamed A Fouda
- Department of Biomedical Physiology and Kinesiology, Simon Fraser University, Burnaby, Canada.,Department of Pharmacology and Toxicology, Alexandria University, Alexandria, Egypt
| | | | - Peter C Ruben
- Department of Biomedical Physiology and Kinesiology, Simon Fraser University, Burnaby, Canada
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6
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Daimi H, Lozano-Velasco E, Aranega A, Franco D. Genomic and Non-Genomic Regulatory Mechanisms of the Cardiac Sodium Channel in Cardiac Arrhythmias. Int J Mol Sci 2022; 23:1381. [PMID: 35163304 PMCID: PMC8835759 DOI: 10.3390/ijms23031381] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2021] [Revised: 12/30/2021] [Accepted: 01/06/2022] [Indexed: 12/19/2022] Open
Abstract
Nav1.5 is the predominant cardiac sodium channel subtype, encoded by the SCN5A gene, which is involved in the initiation and conduction of action potentials throughout the heart. Along its biosynthesis process, Nav1.5 undergoes strict genomic and non-genomic regulatory and quality control steps that allow only newly synthesized channels to reach their final membrane destination and carry out their electrophysiological role. These regulatory pathways are ensured by distinct interacting proteins that accompany the nascent Nav1.5 protein along with different subcellular organelles. Defects on a large number of these pathways have a tremendous impact on Nav1.5 functionality and are thus intimately linked to cardiac arrhythmias. In the present review, we provide current state-of-the-art information on the molecular events that regulate SCN5A/Nav1.5 and the cardiac channelopathies associated with defects in these pathways.
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Affiliation(s)
- Houria Daimi
- Biochemistry and Molecular Biology Laboratory, Faculty of Pharmacy, University of Monastir, Monastir 5000, Tunisia
| | - Estefanía Lozano-Velasco
- Department of Experimental Biology, University of Jaen, 23071 Jaen, Spain; (E.L.-V.); (A.A.); (D.F.)
- Medina Foundation, Technology Park of Health Sciences, Av. del Conocimiento, 34, 18016 Granada, Spain
| | - Amelia Aranega
- Department of Experimental Biology, University of Jaen, 23071 Jaen, Spain; (E.L.-V.); (A.A.); (D.F.)
- Medina Foundation, Technology Park of Health Sciences, Av. del Conocimiento, 34, 18016 Granada, Spain
| | - Diego Franco
- Department of Experimental Biology, University of Jaen, 23071 Jaen, Spain; (E.L.-V.); (A.A.); (D.F.)
- Medina Foundation, Technology Park of Health Sciences, Av. del Conocimiento, 34, 18016 Granada, Spain
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7
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Emerging Anti-Atherosclerotic Therapies. Int J Mol Sci 2021; 22:ijms222212109. [PMID: 34829992 PMCID: PMC8624828 DOI: 10.3390/ijms222212109] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2021] [Revised: 10/24/2021] [Accepted: 11/02/2021] [Indexed: 12/11/2022] Open
Abstract
Cardiovascular disease (CAD) is the main cause of morbidity and deaths in the western world. The development of atherosclerosis underlying CAD development begins early in human life. There are numerous genetic and environmental risk factors accelerating its progression which then leads to the occurrence of acute events. Despite considerable progress in determining risk factors, there is still a lot of work ahead since identified determinants are responsible only for a part of overall CAD risk. Current therapies are insufficient to successfully reduce the risk of atherosclerosis development. Therefore, there is a need for effective preventive measures of clinical manifestations of atherosclerosis since the currently available drugs cannot prevent the occurrence of even 70% of clinical events. The shift of the target from lipid metabolism has opened the door to many new therapeutic targets. Currently, the majority of known targets for anti-atherosclerotic drugs focus also on inflammation (a common mediator of many risk factors), mechanisms of innate and adaptive immunity in atherosclerosis, molecule scavengers, etc. The therapeutic potential of cyclodextrins, protein kinase inhibitors, colchicine, inhibitors of p38 mitogen-activated protein kinase (MAPK), lipid dicarbonyl scavengers, a monoclonal antibody targeting interleukin-1β, and P-selectin inhibitors is still not fully confirmed and requires confirmation in large clinical trials. The preliminary results look promising.
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May-Zhang LS, Kirabo A, Huang J, Linton MF, Davies SS, Murray KT. Scavenging Reactive Lipids to Prevent Oxidative Injury. Annu Rev Pharmacol Toxicol 2020; 61:291-308. [PMID: 32997599 DOI: 10.1146/annurev-pharmtox-031620-035348] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Oxidative injury due to elevated levels of reactive oxygen species is implicated in cardiovascular diseases, Alzheimer's disease, lung and liver diseases, and many cancers. Antioxidant therapies have generally been ineffective at treating these diseases, potentially due to ineffective doses but also due to interference with critical host defense and signaling processes. Therefore, alternative strategies to prevent oxidative injury are needed. Elevated levels of reactive oxygen species induce lipid peroxidation, generating reactive lipid dicarbonyls. These lipid oxidation products may be the most salient mediators of oxidative injury, as they cause cellular and organ dysfunction by adducting to proteins, lipids, and DNA. Small-molecule compounds have been developed in the past decade to selectively and effectively scavenge these reactive lipid dicarbonyls. This review outlines evidence supporting the role of lipid dicarbonyls in disease pathogenesis, as well as preclinical data supporting the efficacy of novel dicarbonyl scavengers in treating or preventing disease.
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Affiliation(s)
- Linda S May-Zhang
- Division of Clinical Pharmacology, Departments of Medicine and Pharmacology, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-6602, USA;
| | - Annet Kirabo
- Division of Clinical Pharmacology, Departments of Medicine and Pharmacology, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-6602, USA;
| | - Jiansheng Huang
- Division of Clinical Pharmacology, Departments of Medicine and Pharmacology, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-6602, USA;
| | - MacRae F Linton
- Division of Clinical Pharmacology, Departments of Medicine and Pharmacology, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-6602, USA;
| | - Sean S Davies
- Division of Clinical Pharmacology, Departments of Medicine and Pharmacology, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-6602, USA;
| | - Katherine T Murray
- Division of Clinical Pharmacology, Departments of Medicine and Pharmacology, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-6602, USA;
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Liu M, Dudley SC. Magnesium, Oxidative Stress, Inflammation, and Cardiovascular Disease. Antioxidants (Basel) 2020; 9:E907. [PMID: 32977544 PMCID: PMC7598282 DOI: 10.3390/antiox9100907] [Citation(s) in RCA: 53] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2020] [Revised: 09/17/2020] [Accepted: 09/18/2020] [Indexed: 12/15/2022] Open
Abstract
Hypomagnesemia is commonly observed in heart failure, diabetes mellitus, hypertension, and cardiovascular diseases. Low serum magnesium (Mg) is a predictor for cardiovascular and all-cause mortality and treating Mg deficiency may help prevent cardiovascular disease. In this review, we discuss the possible mechanisms by which Mg deficiency plays detrimental roles in cardiovascular diseases and review the results of clinical trials of Mg supplementation for heart failure, arrhythmias and other cardiovascular diseases.
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Affiliation(s)
- Man Liu
- Division of Cardiology, Department of Medicine, the Lillehei Heart Institute, University of Minnesota at Twin Cities, Minneapolis, MN 55455, USA
| | - Samuel C. Dudley
- Division of Cardiology, Department of Medicine, the Lillehei Heart Institute, University of Minnesota at Twin Cities, Minneapolis, MN 55455, USA
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Scavenging of reactive dicarbonyls with 2-hydroxybenzylamine reduces atherosclerosis in hypercholesterolemic Ldlr -/- mice. Nat Commun 2020; 11:4084. [PMID: 32796843 PMCID: PMC7429830 DOI: 10.1038/s41467-020-17915-w] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Accepted: 07/27/2020] [Indexed: 12/21/2022] Open
Abstract
Lipid peroxidation generates reactive dicarbonyls including isolevuglandins (IsoLGs) and malondialdehyde (MDA) that covalently modify proteins. Humans with familial hypercholesterolemia (FH) have increased lipoprotein dicarbonyl adducts and dysfunctional HDL. We investigate the impact of the dicarbonyl scavenger, 2-hydroxybenzylamine (2-HOBA) on HDL function and atherosclerosis in Ldlr−/− mice, a model of FH. Compared to hypercholesterolemic Ldlr−/− mice treated with vehicle or 4-HOBA, a nonreactive analogue, 2-HOBA decreases atherosclerosis by 60% in en face aortas, without changing plasma cholesterol. Ldlr−/− mice treated with 2-HOBA have reduced MDA-LDL and MDA-HDL levels, and their HDL display increased capacity to reduce macrophage cholesterol. Importantly, 2-HOBA reduces the MDA- and IsoLG-lysyl content in atherosclerotic aortas versus 4-HOBA. Furthermore, 2-HOBA reduces inflammation and plaque apoptotic cells and promotes efferocytosis and features of stable plaques. Dicarbonyl scavenging with 2-HOBA has multiple atheroprotective effects in a murine FH model, supporting its potential as a therapeutic approach for atherosclerotic cardiovascular disease. Hypercholesterolemia is associated with lipid peroxidation induced reactive dicarbonyl adducts. Here the authors show that the dicarbonyl scavenger, 2-hydroxybenzylamine(2-HOBA), decreases reactive dicarbonyl modifications of LDL and HDL, improves HDL function, reduces atherosclerosis and promotes features of stable plaques in a mouse model of hypercholestrolemia.
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Juang JMJ, Binda A, Lee SJ, Hwang JJ, Chen WJ, Liu YB, Lin LY, Yu CC, Ho LT, Huang HC, Chen CYJ, Lu TP, Lai LC, Yeh SFS, Lai LP, Chuang EY, Rivolta I, Antzelevitch C. GSTM3 variant is a novel genetic modifier in Brugada syndrome, a disease with risk of sudden cardiac death. EBioMedicine 2020; 57:102843. [PMID: 32645615 PMCID: PMC7341360 DOI: 10.1016/j.ebiom.2020.102843] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2020] [Revised: 05/28/2020] [Accepted: 06/03/2020] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND Brugada syndrome (BrS) is a rare inherited disease causing sudden cardiac death (SCD). Copy number variants (CNVs) can contribute to disease susceptibility, but their role in Brugada syndrome (BrS) is unknown. We aimed to identify a CNV associated with BrS and elucidated its clinical implications. METHODS We enrolled 335 unrelated BrS patients from 2000 to 2018 in the Taiwanese population. Microarray and exome sequencing were used for discovery phase whereas Sanger sequencing was used for the validation phase. HEK cells and zebrafish were used to characterize the function of the CNV variant. FINDINGS A copy number deletion of GSTM3 (chr1:109737011-109737301, hg38) containing the eighth exon and the transcription stop codon was observed in 23.9% of BrS patients versus 0.8% of 15,829 controls in Taiwan Biobank (P < 0.001), and 0% in gnomAD. Co-segregation analysis showed that the co-segregation rate was 20%. Patch clamp experiments showed that in an oxidative stress environment, GSTM3 down-regulation leads to a significant decrease of cardiac sodium channel current amplitude. Ventricular arrhythmia incidence was significantly greater in gstm3 knockout zebrafish at baseline and after flecainide, but was reduced after quinidine, consistent with clinical observations. BrS patients carrying the GSTM3 deletion had higher rates of sudden cardiac arrest and syncope compared to those without (OR: 3.18 (1.77-5.74), P<0.001; OR: 1.76 (1.02-3.05), P = 0.04, respectively). INTERPRETATION This GSTM3 deletion is frequently observed in BrS patients and is associated with reduced INa, pointing to this as a novel potential genetic modifier/risk predictor for the development of the electrocardiographic and arrhythmic manifestations of BrS. FUNDING This work was supported by the Ministry of Science and Technology (107-2314-B-002-261-MY3 to J.M.J. Juang), and by grants HL47678, HL138103 and HL152201 from the National Institutes of Health to CA.
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Affiliation(s)
- Jyh-Ming Jimmy Juang
- Cardiovascular Center and Division of Cardiology, Department of Internal Medicine, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan
| | - Anna Binda
- University of Milano Bicocca School of Medicine and Surgery, Via Cadore, 48, 20900 Monza (MB), Italy
| | - Shyh-Jye Lee
- Department of Life Science, National Taiwan University, Taipei, Taiwan
| | - Juey-Jen Hwang
- Cardiovascular Center and Division of Cardiology, Department of Internal Medicine, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan
| | - Wen-Jone Chen
- Cardiovascular Center and Division of Cardiology, Department of Internal Medicine, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan
| | - Yen-Bin Liu
- Cardiovascular Center and Division of Cardiology, Department of Internal Medicine, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan
| | - Lian-Yu Lin
- Cardiovascular Center and Division of Cardiology, Department of Internal Medicine, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan
| | - Chih-Chieh Yu
- Cardiovascular Center and Division of Cardiology, Department of Internal Medicine, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan
| | - Li-Ting Ho
- Cardiovascular Center and Division of Cardiology, Department of Internal Medicine, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan
| | - Hui-Chun Huang
- Cardiovascular Center and Division of Cardiology, Department of Internal Medicine, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan
| | - Ching-Yu Julius Chen
- Cardiovascular Center and Division of Cardiology, Department of Internal Medicine, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan
| | - Tzu-Pin Lu
- Institute of Epidemiology and Preventive Medicine, National Taiwan University, Taipei, Taiwan; Department of Public Health, National Taiwan University, Taipei, Taiwan.
| | - Liang-Chuan Lai
- Graduate Institute of Physiology, National Taiwan University, Taipei, Taiwan
| | - Shih-Fan Sherri Yeh
- Department of Environmental and Occupational Medicine, National Taiwan University Hospital, Hsin-Chu branch and National Taiwan University College of Medicine, Taipei, Taiwan
| | - Ling-Ping Lai
- Cardiovascular Center and Division of Cardiology, Department of Internal Medicine, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan
| | - Eric Y Chuang
- Graduate Institute of Biomedical Electronics and Bioinformatics, National Taiwan University, Taipei, Taiwan
| | - Ilaria Rivolta
- University of Milano Bicocca School of Medicine and Surgery, Via Cadore, 48, 20900 Monza (MB), Italy
| | - Charles Antzelevitch
- Lankenau Institute for Medical Research and Lankenau Heart Institute, Wynnewood, PA and Sidney Kimmel Medical College of Thomas Jefferson University, Philadelphia, PA, USA.
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Prinsen JK, Kannankeril PJ, Sidorova TN, Yermalitskaya LV, Boutaud O, Zagol-Ikapitte I, Barnett JV, Murphy MB, Subati T, Stark JM, Christopher IL, Jafarian-Kerman SR, Saleh MA, Norlander AE, Loperena R, Atkinson JB, Fogo AB, Luther JM, Amarnath V, Davies SS, Kirabo A, Madhur MS, Harrison DG, Murray KT. Highly Reactive Isolevuglandins Promote Atrial Fibrillation Caused by Hypertension. JACC Basic Transl Sci 2020; 5:602-615. [PMID: 32613146 PMCID: PMC7315188 DOI: 10.1016/j.jacbts.2020.04.004] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/02/2020] [Revised: 03/31/2020] [Accepted: 04/02/2020] [Indexed: 01/11/2023]
Abstract
Oxidative damage is implicated in atrial fibrillation (AF), but antioxidants are ineffective therapeutically. The authors tested the hypothesis that highly reactive lipid dicarbonyl metabolites, or isolevuglandins (IsoLGs), are principal drivers of AF during hypertension. In a hypertensive murine model and stretched atriomyocytes, the dicarbonyl scavenger 2-hydroxybenzylamine (2-HOBA) prevented IsoLG adducts and preamyloid oligomers (PAOs), and AF susceptibility, whereas the ineffective analog 4-hydroxybenzylamine (4-HOBA) had minimal effect. Natriuretic peptides generated cytotoxic oligomers, a process accelerated by IsoLGs, contributing to atrial PAO formation. These findings support the concept of pre-emptively scavenging reactive downstream oxidative stress mediators as a potential therapeutic approach to prevent AF.
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Key Words
- 2-HOBA, 2-hydroxylbenzylamine
- 4-HOBA, 4-hydroxylbenzylamine
- AF, atrial fibrillation
- ANP, atrial natriuretic peptide
- B-type natriuretic peptide
- BNP, B-type natriuretic peptide
- BP, blood pressure
- ECG, electrocardiogram
- G/R, green/red ratio
- IsoLG, isolevuglandin
- PAO, preamyloid oligomer
- PBS, phosphate-buffered saline
- ROS, reactive oxygen species
- ang II, angiotensin II
- atrial fibrillation
- atrial natriuretic peptide
- hypertension
- isolevuglandins
- oxidative stress
- preamyloid oligomers
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Affiliation(s)
- Joseph K. Prinsen
- Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee
- Department of Pharmacology, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Prince J. Kannankeril
- Department of Pediatrics, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Tatiana N. Sidorova
- Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee
- Department of Pharmacology, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Liudmila V. Yermalitskaya
- Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee
- Department of Pharmacology, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Olivier Boutaud
- Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee
- Department of Pharmacology, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Irene Zagol-Ikapitte
- Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee
- Department of Pharmacology, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Joey V. Barnett
- Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee
- Department of Pharmacology, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Matthew B. Murphy
- Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee
- Department of Pharmacology, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Tuerdi Subati
- Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee
- Department of Pharmacology, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Joshua M. Stark
- Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee
- Department of Pharmacology, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Isis L. Christopher
- Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee
- Department of Pharmacology, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Scott R. Jafarian-Kerman
- Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee
- Department of Pharmacology, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Mohamed A. Saleh
- Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee
- Department of Pharmacology, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Allison E. Norlander
- Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee
- Department of Pharmacology, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Roxana Loperena
- Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee
- Department of Pharmacology, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - James B. Atkinson
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Agnes B. Fogo
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - James M. Luther
- Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee
- Department of Pharmacology, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Venkataraman Amarnath
- Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee
- Department of Pharmacology, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Sean S. Davies
- Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee
- Department of Pharmacology, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Annet Kirabo
- Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee
- Department of Pharmacology, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Meena S. Madhur
- Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee
- Department of Pharmacology, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - David G. Harrison
- Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee
- Department of Pharmacology, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Katherine T. Murray
- Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee
- Department of Pharmacology, Vanderbilt University School of Medicine, Nashville, Tennessee
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Fouda MA, Ghovanloo MR, Ruben PC. Cannabidiol protects against high glucose-induced oxidative stress and cytotoxicity in cardiac voltage-gated sodium channels. Br J Pharmacol 2020; 177:2932-2946. [PMID: 32077098 DOI: 10.1111/bph.15020] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Revised: 12/23/2019] [Accepted: 01/14/2020] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND AND PURPOSE Cardiovascular complications are the major cause of mortality in diabetic patients. However, the molecular mechanisms underlying diabetes-associated arrhythmias are unclear. We hypothesized that high glucose could adversely affect Nav 1.5, the major cardiac sodium channel isoform of the heart, at least partially via oxidative stress. We further hypothesized that cannabidiol (CBD), one of the main constituents of Cannabis sativa, through its effects on Nav 1.5, could protect against high glucose-elicited oxidative stress and cytotoxicity. EXPERIMENTAL APPROACH To test these ideas, we used CHO cells transiently co-transfected with cDNA encoding human Nav 1.5 α-subunit under control and high glucose conditions (50 or 100 mM for 24 hr). Several experimental and computational techniques were used, including voltage clamp of heterologous expression systems, cell viability assays, fluorescence assays and action potential modelling. KEY RESULTS High glucose evoked cell death associated with elevation in reactive oxygen species (ROS) right shifted the voltage dependence of conductance and steady-state fast inactivation, and increased persistent current leading to computational prolongation of action potential (hyperexcitability) which could result in long QT3 arrhythmia. CBD mitigated all the deleterious effects provoked by high glucose. Perfusion with lidocaine (a well-known sodium channel inhibitor with antioxidant effects) or co-incubation of Tempol (a well-known antioxidant) elicited protection, comparable to CBD, against the deleterious effects of high glucose. CONCLUSION AND IMPLICATIONS These findings suggest that, through its favourable antioxidant and sodium channel inhibitory effects, CBD may protect against high glucose-induced arrhythmia and cytotoxicity.
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Affiliation(s)
- Mohamed A Fouda
- Department of Biomedical Physiology and Kinesiology, Simon Fraser University, Burnaby, British Columbia, Canada.,Department of Pharmacology and Toxicology, Alexandria University, Alexandria, Egypt
| | - Mohammad-Reza Ghovanloo
- Department of Biomedical Physiology and Kinesiology, Simon Fraser University, Burnaby, British Columbia, Canada
| | - Peter C Ruben
- Department of Biomedical Physiology and Kinesiology, Simon Fraser University, Burnaby, British Columbia, Canada
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Davies SS, May-Zhang LS, Boutaud O, Amarnath V, Kirabo A, Harrison DG. Isolevuglandins as mediators of disease and the development of dicarbonyl scavengers as pharmaceutical interventions. Pharmacol Ther 2019; 205:107418. [PMID: 31629006 DOI: 10.1016/j.pharmthera.2019.107418] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2019] [Accepted: 09/20/2019] [Indexed: 12/13/2022]
Abstract
Products of lipid peroxidation include a number of reactive lipid aldehydes such as malondialdehyde, 4-hydroxy-nonenal, 4-oxo-nonenal, and isolevuglandins (IsoLGs). Although these all contribute to disease processes, the most reactive are the IsoLGs, which rapidly adduct to lysine and other cellular primary amines, leading to changes in protein function, cross-linking and immunogenicity. Their rapid reactivity means that only IsoLG adducts, and not the unreacted aldehyde, can be readily measured. This high reactivity also makes it challenging for standard cellular defense mechanisms such as aldehyde reductases and oxidases to dispose of them before they react with proteins and other cellular amines. This led us to seek small molecule primary amines that might trap and inactivate IsoLGs before they could modify cellular proteins or other endogenous cellular amines such as phosphatidylethanolamines to cause disease. Our studies identified 2-aminomethylphenols including 2-hydroxybenzylamine as IsoLG scavengers. Subsequent studies showed that they also trap other lipid dicarbonyls that react with primary amines such as 4-oxo-nonenal and malondialdehyde, but not hydroxyalkenals like 4-hydroxy-nonenal that preferentially react with soft nucleophiles. This review describes the use of these 2-aminomethylphenols as dicarbonyl scavengers to assess the contribution of IsoLGs and other amine-reactive lipid dicarbonyls to disease and as therapeutic agents.
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Affiliation(s)
- Sean S Davies
- Division of Clinical Pharmacology and Departments of Pharmacology and Medicine, Vanderbilt University, Nashville, TN, United States.
| | - Linda S May-Zhang
- Division of Clinical Pharmacology and Departments of Pharmacology and Medicine, Vanderbilt University, Nashville, TN, United States
| | - Olivier Boutaud
- Division of Clinical Pharmacology and Departments of Pharmacology and Medicine, Vanderbilt University, Nashville, TN, United States
| | - Venkataraman Amarnath
- Division of Clinical Pharmacology and Departments of Pharmacology and Medicine, Vanderbilt University, Nashville, TN, United States
| | - Annet Kirabo
- Division of Clinical Pharmacology and Departments of Pharmacology and Medicine, Vanderbilt University, Nashville, TN, United States
| | - David G Harrison
- Division of Clinical Pharmacology and Departments of Pharmacology and Medicine, Vanderbilt University, Nashville, TN, United States
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15
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Gęgotek A, Skrzydlewska E. Biological effect of protein modifications by lipid peroxidation products. Chem Phys Lipids 2019; 221:46-52. [DOI: 10.1016/j.chemphyslip.2019.03.011] [Citation(s) in RCA: 50] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Revised: 02/26/2019] [Accepted: 03/24/2019] [Indexed: 01/26/2023]
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16
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Davies SS, May-Zhang LS. Isolevuglandins and cardiovascular disease. Prostaglandins Other Lipid Mediat 2018; 139:29-35. [PMID: 30296489 DOI: 10.1016/j.prostaglandins.2018.10.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Revised: 09/25/2018] [Accepted: 10/03/2018] [Indexed: 11/30/2022]
Abstract
Isolevuglandins are 4-ketoaldehydes formed by peroxidation of arachidonic acid. Isolevuglandins react rapidly with primary amines including the lysyl residues of proteins to form irreversible covalent modifications. This review highlights evidence for the potential role of isolevuglandin modification in the disease processes, especially atherosclerosis, and some of the tools including small molecule dicarbonyl scavengers utilized to assess their contributions to disease.
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Affiliation(s)
- Sean S Davies
- Department of Pharmacology, Division of Clinical Pharmacology, Vanderbilt University, Nashville, TN, United States.
| | - Linda S May-Zhang
- Department of Pharmacology, Division of Clinical Pharmacology, Vanderbilt University, Nashville, TN, United States
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17
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Mutant α-Synuclein Overexpression Induces Stressless Pacemaking in Vagal Motoneurons at Risk in Parkinson's Disease. J Neurosci 2017; 37:47-57. [PMID: 28053029 DOI: 10.1523/jneurosci.1079-16.2016] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2016] [Revised: 10/20/2016] [Accepted: 10/27/2016] [Indexed: 01/03/2023] Open
Abstract
α-Synuclein overexpression (ASOX) drives the formation of toxic aggregates in neurons vulnerable in Parkinson's disease (PD), including dopaminergic neurons of the substantia nigra (SN) and cholinergic neurons of the dorsal motor nucleus of the vagus (DMV). Just as these populations differ in when they exhibit α-synucleinopathies during PD pathogenesis, they could also differ in their physiological responses to ASOX. An ASOX-mediated hyperactivity of SN dopamine neurons, which was caused by oxidative dysfunction of Kv4.3 potassium channels, was recently identified in transgenic (A53T-SNCA) mice overexpressing mutated human α-synuclein. Noting that DMV neurons display extensive α-synucleinopathies earlier than SN dopamine neurons while exhibiting milder cell loss in PD, we aimed to define the electrophysiological properties of DMV neurons in A53T-SNCA mice. We found that DMV neurons maintain normal firing rates in response to ASOX. Moreover, Kv4.3 channels in DMV neurons exhibit no oxidative dysfunction in the A53T-SNCA mice, which could only be recapitulated in wild-type mice by glutathione dialysis. Two-photon imaging of redox-sensitive GFP corroborated the finding that mitochondrial oxidative stress was diminished in DMV neurons in the A53T-SNCA mice. This reduction in oxidative stress resulted from a transcriptional downregulation of voltage-activated (Cav) calcium channels in DMV neurons, which led to a reduction in activity-dependent calcium influx via Cav channels. Thus, ASOX induces a homeostatic remodeling with improved redox signaling in DMV neurons, which could explain the differential vulnerability of SN dopamine and DMV neurons in PD and could promote neuroprotective strategies that emulate endogenous homeostatic responses to ASOX (e.g., stressless pacemaking) in DMV neurons. SIGNIFICANCE STATEMENT Overexpression of mutant α-synuclein causes Parkinson's disease, presumably by driving neurodegeneration in vulnerable neuronal target populations. However, the extent of α-synuclein pathology (e.g., Lewy bodies) is not directly related to the degree of neurodegeneration across various vulnerable neuronal populations. Here, we show that, in contrast to dopamine neurons in the substantia nigra, vagal motoneurons do not enhance their excitability and oxidative load in response to chronic mutant α-synuclein overexpression. Rather, by downregulating their voltage-activated calcium channels, vagal motoneurons acquire a stressless form of pacemaking that diminishes mitochondrial and cytosolic oxidative stress. Emulating this endogenous adaptive response to α-synuclein overexpression could lead to novel strategies to protect dopamine neurons and perhaps delay the onset of Parkinson's disease.
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Davies SS, Zhang LS. Reactive Carbonyl Species Scavengers-Novel Therapeutic Approaches for Chronic Diseases. ACTA ACUST UNITED AC 2017; 3:51-67. [PMID: 28993795 DOI: 10.1007/s40495-017-0081-6] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
PURPOSE OF THE REVIEW To summarize recent evidence supporting the use of reactive carbonyl species scavengers in the prevention and treatment of disease. RECENT FINDINGS The newly developed 2-aminomethylphenol class of scavengers shows great promise in preclinical trials for a number of diverse conditions including neurodegenerative diseases and cardiovascular disease. In addition, new studies with the thiol-based and imidazole-based scavengers have found new applications outside of adjunctive therapy for chemotherapeutics. SUMMARY Reactive oxygen species (ROS) generated by cells and tissues act as signaling molecules and as cytotoxic agents to defend against pathogens, but ROS also cause collateral damage to vital cellular components. The polyunsaturated fatty acyl chains of phospholipids in the cell membranes are particularly vulnerable to damaging peroxidation by ROS. Evidence suggests that the breakdown of these peroxidized lipids to reactive carbonyls species plays a critical role in many chronic diseases. Antioxidants that abrogate ROS-induced formation of reactive carbonyl species also abrogate normal ROS signaling and thus exert both beneficial and adverse functional effects. The use of scavengers of reactive dicarbonyl species represent an alternative therapeutic strategy to potentially mitigate the adverse effects of ROS without abrogating normal signaling by ROS. In this review, we focus on three classes of reactive carbonyl species scavengers: thiol-based scavengers (2-mercaptoethanesulfonate and amifostine), imidazole-based scavengers (carnosine and its analogs), and 2-aminomethylphenols-based scavengers (pyridoxamine, 2-hydroxybenzylamine, and 5'-O-pentyl-pyridoxamine) that are either undergoing pre-clinical studies, advancing to clinical trials, or are already in clinical use.
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Affiliation(s)
- Sean S Davies
- Department of Pharmacology and Division of Clinical Pharmacology, Vanderbilt University, 556 Robinson Research Building, 2220 Pierce Avenue, Nashville, TN 37232-6602
| | - Linda S Zhang
- Department of Pharmacology and Division of Clinical Pharmacology, Vanderbilt University, 556 Robinson Research Building, 2220 Pierce Avenue, Nashville, TN 37232-6602
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19
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Elinder F, Liin SI. Actions and Mechanisms of Polyunsaturated Fatty Acids on Voltage-Gated Ion Channels. Front Physiol 2017; 8:43. [PMID: 28220076 PMCID: PMC5292575 DOI: 10.3389/fphys.2017.00043] [Citation(s) in RCA: 88] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2016] [Accepted: 01/16/2017] [Indexed: 01/29/2023] Open
Abstract
Polyunsaturated fatty acids (PUFAs) act on most ion channels, thereby having significant physiological and pharmacological effects. In this review we summarize data from numerous PUFAs on voltage-gated ion channels containing one or several voltage-sensor domains, such as voltage-gated sodium (NaV), potassium (KV), calcium (CaV), and proton (HV) channels, as well as calcium-activated potassium (KCa), and transient receptor potential (TRP) channels. Some effects of fatty acids appear to be channel specific, whereas others seem to be more general. Common features for the fatty acids to act on the ion channels are at least two double bonds in cis geometry and a charged carboxyl group. In total we identify and label five different sites for the PUFAs. PUFA site 1: The intracellular cavity. Binding of PUFA reduces the current, sometimes as a time-dependent block, inducing an apparent inactivation. PUFA site 2: The extracellular entrance to the pore. Binding leads to a block of the channel. PUFA site 3: The intracellular gate. Binding to this site can bend the gate open and increase the current. PUFA site 4: The interface between the extracellular leaflet of the lipid bilayer and the voltage-sensor domain. Binding to this site leads to an opening of the channel via an electrostatic attraction between the negatively charged PUFA and the positively charged voltage sensor. PUFA site 5: The interface between the extracellular leaflet of the lipid bilayer and the pore domain. Binding to this site affects slow inactivation. This mapping of functional PUFA sites can form the basis for physiological and pharmacological modifications of voltage-gated ion channels.
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Affiliation(s)
- Fredrik Elinder
- Department of Clinical and Experimental Medicine, Linköping University Linköping, Sweden
| | - Sara I Liin
- Department of Clinical and Experimental Medicine, Linköping University Linköping, Sweden
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20
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Mont S, Davies SS, Roberts second LJ, Mernaugh RL, McDonald WH, Segal BH, Zackert W, Kropski JA, Blackwell TS, Sekhar KR, Galligan JJ, Massion PP, Marnett LJ, Travis EL, Freeman ML. Accumulation of isolevuglandin-modified protein in normal and fibrotic lung. Sci Rep 2016; 6:24919. [PMID: 27118599 PMCID: PMC4847119 DOI: 10.1038/srep24919] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2016] [Accepted: 04/07/2016] [Indexed: 12/27/2022] Open
Abstract
Protein lysine modification by γ-ketoaldehyde isomers derived from arachidonic acid, termed isolevuglandins (IsoLGs), is emerging as a mechanistic link between pathogenic reactive oxygen species and disease progression. However, the questions of whether covalent modification of proteins by IsoLGs are subject to genetic regulation and the identity of IsoLG-modified proteins remain unclear. Herein we show that Nrf2 and Nox2 are key regulators of IsoLG modification in pulmonary tissue and report on the identity of proteins analyzed by LC-MS following immunoaffinity purification of IsoLG-modified proteins. Gene ontology analysis revealed that proteins in numerous cellular pathways are susceptible to IsoLG modification. Although cells tolerate basal levels of modification, exceeding them induces apoptosis. We found prominent modification in a murine model of radiation-induced pulmonary fibrosis and in idiopathic pulmonary fibrosis, two diseases considered to be promoted by gene-regulated oxidant stress. Based on these results we hypothesize that IsoLG modification is a hitherto unrecognized sequelae that contributes to radiation-induced pulmonary injury and IPF.
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Affiliation(s)
- Stacey Mont
- Department of Cancer Biology, Vanderbilt University Medical Center, Nashville, TN 37240, USA
- Department of Radiation Oncology, Vanderbilt University Medical Center, Nashville, TN 37240, USA
| | - Sean S. Davies
- Division of Clinical Pharmacology, Department of Pharmacology, Vanderbilt University Medical Center, Nashville, TN 37240, USA
| | - L. Jackson Roberts second
- Division of Clinical Pharmacology, Department of Pharmacology, Vanderbilt University Medical Center, Nashville, TN 37240, USA
| | - Raymond L. Mernaugh
- Department of Biochemistry, Vanderbilt University Medical Center, Nashville, TN 37240, USA
| | - W. Hayes McDonald
- Department of Biochemistry, Vanderbilt University Medical Center, Nashville, TN 37240, USA
- Proteomics Laboratory and Mass Spectrometry Research Center, Vanderbilt University Medical Center, Nashville, TN 37240, USA
| | - Brahm H. Segal
- Department of Medicine, Department of Immunology, Roswell Park Cancer Institute, and University at Buffalo Jacobs School of Medicine and Biomedical Sciences, Buffalo, NY, 14263, USA
| | - William Zackert
- Division of Clinical Pharmacology, Department of Pharmacology, Vanderbilt University Medical Center, Nashville, TN 37240, USA
| | - Jonathan A. Kropski
- Division of Pulmonary & Critical Care, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN 37240, USA
| | - Timothy S. Blackwell
- Division of Pulmonary & Critical Care, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN 37240, USA
| | - Konjeti R. Sekhar
- Department of Radiation Oncology, Vanderbilt University Medical Center, Nashville, TN 37240, USA
| | - James J. Galligan
- Department of Biochemistry, Vanderbilt University Medical Center, Nashville, TN 37240, USA
| | - Pierre P. Massion
- Division of Pulmonary & Critical Care, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN 37240, USA
| | - Lawrence J. Marnett
- Department of Biochemistry, Vanderbilt University Medical Center, Nashville, TN 37240, USA
- A.B. Hancock Jr. Memorial Laboratory for Cancer Research, Vanderbilt Institute of Chemical Biology, Vanderbilt-Ingram Cancer Center, Vanderbilt University Medical Center, Nashville, TN 37240, USA
| | - Elizabeth L. Travis
- Department of Experimental Radiation Oncology, Division of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX 77230, USA
| | - Michael L. Freeman
- Department of Radiation Oncology, Vanderbilt University Medical Center, Nashville, TN 37240, USA
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Patel R, Sesti F. Oxidation of ion channels in the aging nervous system. Brain Res 2016; 1639:174-85. [PMID: 26947620 DOI: 10.1016/j.brainres.2016.02.046] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2015] [Revised: 02/24/2016] [Accepted: 02/25/2016] [Indexed: 12/19/2022]
Abstract
Ion channels are integral membrane proteins that allow passive diffusion of ions across membranes. In neurons and in other excitable cells, the harmonious coordination between the numerous types of ion channels shape and propagate electrical signals. Increased accumulation of reactive oxidative species (ROS), and subsequent oxidation of proteins, including ion channels, is a hallmark feature of aging and may contribute to cell failure as a result. In this review we discuss the effects of ROS on three major types of ion channels of the central nervous system, namely the potassium (K(+)), calcium (Ca(2+)) and sodium (Na(+)) channels. We examine two general mechanisms through which ROS affect ion channels: via direct oxidation of specific residues and via indirect interference of pathways that regulate the channels. The overall status of the present studies indicates that the interaction of ion channels with ROS is multimodal and pervasive in the central nervous system and likely constitutes a general mechanism of aging susceptibility.
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Affiliation(s)
- Rahul Patel
- Department of Neuroscience and Cell Biology, Robert Wood Johnson Medical School, Rutgers University, 683 Hoes Lane West, Piscataway, NJ 08854, USA
| | - Federico Sesti
- Department of Neuroscience and Cell Biology, Robert Wood Johnson Medical School, Rutgers University, 683 Hoes Lane West, Piscataway, NJ 08854, USA.
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Abstract
SIGNIFICANCE A diverse family of lipid-derived levulinaldehydes, isolevuglandins (isoLGs), is produced by rearrangement of endoperoxide intermediates generated through both cyclooxygenase (COX) and free radical-induced cyclooxygenation of polyunsaturated fatty acids and their phospholipid esters. The formation and reactions of isoLGs with other biomolecules has been linked to alcoholic liver disease, Alzheimer's disease, age-related macular degeneration, atherosclerosis, cardiac arythmias, cancer, end-stage renal disease, glaucoma, inflammation of allergies and infection, mitochondrial dysfunction, multiple sclerosis, and thrombosis. This review chronicles progress in understanding the chemistry of isoLGs, detecting their production in vivo and understanding their biological consequences. CRITICAL ISSUES IsoLGs have never been isolated from biological sources, because they form adducts with primary amino groups of other biomolecules within seconds. Chemical synthesis enabled investigation of isoLG chemistry and detection of isoLG adducts present in vivo. RECENT ADVANCES The first peptide mapping and sequencing of an isoLG-modified protein present in human retina identified the modification of a specific lysyl residue of the sterol C27-hydroxylase Cyp27A1. This residue is preferentially modified by iso[4]LGE2 in vitro, causing loss of function. Adduction of less than one equivalent of isoLG can induce COX-associated oligomerization of the amyloid peptide Aβ1-42. Adduction of isoLGE2 to phosphatidylethanolamines causes gain of function, converting them into proinflammatory isoLGE2-PE agonists that foster monocyte adhesion to endothelial cells. FUTURE DIRECTIONS Among the remaining questions on the biochemistry of isoLGs are the dependence of biological activity on isoLG isomer structure, the structures and mechanism of isoLG-derived protein-protein and DNA-protein cross-link formation, and its biological consequences.
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Affiliation(s)
- Robert G Salomon
- Department of Chemistry, Case Western Reserve University, Cleveland, Ohio
| | - Wenzhao Bi
- Department of Chemistry, Case Western Reserve University, Cleveland, Ohio
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Nakajima T, Kaneko Y, Saito A, Ota M, Iijima T, Kurabayashi M. Enhanced fast-inactivated state stability of cardiac sodium channels by a novel voltage sensor SCN5A mutation, R1632C, as a cause of atypical Brugada syndrome. Heart Rhythm 2015; 12:2296-304. [PMID: 26031372 DOI: 10.1016/j.hrthm.2015.05.032] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/10/2015] [Indexed: 12/19/2022]
Abstract
BACKGROUND Mutations in SCN5A, which encodes the cardiac voltage-gated sodium channels, can be associated with multiple electrophysiological phenotypes. A novel SCN5A R1632C mutation, located in the domain IV-segment 4 voltage sensor, was identified in a young male patient who had a syncopal episode during exercise and presented with atrial tachycardia, sinus node dysfunction, and Brugada syndrome. OBJECTIVE We sought to elucidate the functional consequences of the R1632C mutation. METHODS The wild-type (WT) or R1632C SCN5A mutation was coexpressed with β1 subunit in tsA201 cells, and whole-cell sodium currents (INa) were recorded using patch-clamp methods. RESULTS INa density, measured at -20 mV from a holding potential of -120 mV, for R1632C was significantly lower than that for WT (R1632C: -433 ± 52 pA/pF, n = 14; WT: -672 ± 90 pA/pF, n = 15; P < .05); however, no significant changes were observed in the steady-state activation and fast inactivation rate. The steady-state inactivation curve for R1632C was remarkably shifted to hyperpolarizing potentials compared with that for WT (R1632C: V1/2 = -110.7 ± 0.8 mV, n = 16; WT: V1/2 = -85.9 ± 2.5 mV, n = 17; P < .01). The steady-state fast inactivation curve for R1632C was also shifted to the same degree. Recovery from fast inactivation after a 20-ms depolarizing pulse for R1632C was remarkably delayed compared with that for WT (R1632C: τ = 246.7 ± 14.3 ms, n = 8; WT: τ = 3.7 ± 0.3 ms, n = 8; P < .01). Repetitive depolarizing pulses at various cycle lengths greatly attenuated INa for R1632C than that for WT. CONCLUSION R1632C showed a loss of function of INa by an enhanced fast-inactivated state stability because of a pronounced impairment of recovery from fast inactivation, which may explain the phenotypic manifestation observed in our patient.
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Affiliation(s)
- Tadashi Nakajima
- Department of Medicine and Biological Science, Gunma University Graduate School of Medicine, Maebashi, Japan.
| | - Yoshiaki Kaneko
- Department of Medicine and Biological Science, Gunma University Graduate School of Medicine, Maebashi, Japan
| | - Akihiro Saito
- Department of Medicine and Biological Science, Gunma University Graduate School of Medicine, Maebashi, Japan
| | - Masaki Ota
- Department of Medicine and Biological Science, Gunma University Graduate School of Medicine, Maebashi, Japan
| | - Takafumi Iijima
- Department of Medicine and Biological Science, Gunma University Graduate School of Medicine, Maebashi, Japan
| | - Masahiko Kurabayashi
- Department of Medicine and Biological Science, Gunma University Graduate School of Medicine, Maebashi, Japan
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Nakajima T, Kaneko Y, Kurabayashi M. Unveiling specific triggers and precipitating factors for fatal cardiac events in inherited arrhythmia syndromes. Circ J 2015; 79:1185-92. [PMID: 25925977 DOI: 10.1253/circj.cj-15-0322] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Patients with inherited arrhythmia syndromes, such as long QT syndrome, Brugada syndrome, early repolarization syndrome, catecholaminergic polymorphic ventricular tachycardia, and their latent forms, are at risk for fatal arrhythmias. These diseases are typically associated with genetic mutations that perturb cardiac ionic currents. The analysis of cardiac events by genotype-phenotype correlation studies has revealed that fatal arrhythmias in some genotypes are triggered by physical or emotional stress, and those in the others are more likely to occur during sleep or at rest. Thus, the risk stratification and management of affected patients differ strikingly according to the genetic variant of the inherited arrhythmia syndrome. Risk stratification may be further refined by considering the precipitating factors, such as drugs, bradycardia, electrolyte disturbances, fever, and cardiac memory. Moreover, an increasing number of studies imply that the susceptibility of fatal arrhythmias in patients with acute coronary syndrome or takotsubo cardiomyopathy is at least partly ascribed to the genetic variants causing inherited arrhythmia syndromes. In this article, we review the recent advances in the understanding of the molecular genetics and genotype-phenotype correlations in inherited arrhythmia syndromes and consider the triggers and precipitating factors for fatal arrhythmias in these disorders. Further studies to explore the triggers and precipitating factors specific to the genotypes and diseases are needed for better clinical management.
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Affiliation(s)
- Tadashi Nakajima
- Department of Medicine and Biological Science, Gunma University Graduate School of Medicine
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Regulation of the cardiac Na+ channel NaV1.5 by post-translational modifications. J Mol Cell Cardiol 2015; 82:36-47. [PMID: 25748040 DOI: 10.1016/j.yjmcc.2015.02.013] [Citation(s) in RCA: 72] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/09/2014] [Revised: 01/28/2015] [Accepted: 02/17/2015] [Indexed: 02/07/2023]
Abstract
The cardiac voltage-gated Na(+) channel, Na(V)1.5, is responsible for the upstroke of the action potential in cardiomyocytes and for efficient propagation of the electrical impulse in the myocardium. Even subtle alterations of Na(V)1.5 function, as caused by mutations in its gene SCN5A, may lead to many different arrhythmic phenotypes in carrier patients. In addition, acquired malfunctions of Na(V)1.5 that are secondary to cardiac disorders such as heart failure and cardiomyopathies, may also play significant roles in arrhythmogenesis. While it is clear that the regulation of Na(V)1.5 protein expression and function tightly depends on genetic mechanisms, recent studies have demonstrated that Na(V)1.5 is the target of various post-translational modifications that are pivotal not only in physiological conditions, but also in disease. In this review, we examine the recent literature demonstrating glycosylation, phosphorylation by Protein Kinases A and C, Ca(2+)/Calmodulin-dependent protein Kinase II, Phosphatidylinositol 3-Kinase, Serum- and Glucocorticoid-inducible Kinases, Fyn and Adenosine Monophosphate-activated Protein Kinase, methylation, acetylation, redox modifications, and ubiquitylation of Na(V)1.5. Modern and sensitive mass spectrometry approaches, applied directly to channel proteins that were purified from native cardiac tissues, have enabled the determination of the precise location of post-translational modification sites, thus providing essential information for understanding the mechanistic details of these regulations. The current challenge is first, to understand the roles of these modifications on the expression and the function of Na(V)1.5, and second, to further identify other chemical modifications. It is postulated that the diversity of phenotypes observed with Na(V)1.5-dependent disorders may partially arise from the complex post-translational modifications of channel protein components.
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Davies SS, Guo L. Lipid peroxidation generates biologically active phospholipids including oxidatively N-modified phospholipids. Chem Phys Lipids 2014; 181:1-33. [PMID: 24704586 DOI: 10.1016/j.chemphyslip.2014.03.002] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2014] [Revised: 02/28/2014] [Accepted: 03/18/2014] [Indexed: 12/25/2022]
Abstract
Peroxidation of membranes and lipoproteins converts "inert" phospholipids into a plethora of oxidatively modified phospholipids (oxPL) that can act as signaling molecules. In this review, we will discuss four major classes of oxPL: mildly oxygenated phospholipids, phospholipids with oxidatively truncated acyl chains, phospholipids with cyclized acyl chains, and phospholipids that have been oxidatively N-modified on their headgroups by reactive lipid species. For each class of oxPL we will review the chemical mechanisms of their formation, the evidence for their formation in biological samples, the biological activities and signaling pathways associated with them, and the catabolic pathways for their elimination. We will end by briefly highlighting some of the critical questions that remain about the role of oxPL in physiology and disease.
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Affiliation(s)
- Sean S Davies
- Division of Clinical Pharmacology, Department of Pharmacology, Vanderbilt University, United States.
| | - Lilu Guo
- Division of Clinical Pharmacology, Department of Pharmacology, Vanderbilt University, United States
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Herren AW, Bers DM, Grandi E. Post-translational modifications of the cardiac Na channel: contribution of CaMKII-dependent phosphorylation to acquired arrhythmias. Am J Physiol Heart Circ Physiol 2013; 305:H431-45. [PMID: 23771687 DOI: 10.1152/ajpheart.00306.2013] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
The voltage-gated Na channel isoform 1.5 (NaV1.5) is the pore forming α-subunit of the voltage-gated cardiac Na channel, which is responsible for the initiation and propagation of cardiac action potentials. Mutations in the SCN5A gene encoding NaV1.5 have been linked to changes in the Na current leading to a variety of arrhythmogenic phenotypes, and alterations in the NaV1.5 expression level, Na current density, and/or gating have been observed in acquired cardiac disorders, including heart failure. The precise mechanisms underlying these abnormalities have not been fully elucidated. However, several recent studies have made it clear that NaV1.5 forms a macromolecular complex with a number of proteins that modulate its expression levels, localization, and gating and is the target of extensive post-translational modifications, which may also influence all these properties. We review here the molecular aspects of cardiac Na channel regulation and their functional consequences. In particular, we focus on the molecular and functional aspects of Na channel phosphorylation by the Ca/calmodulin-dependent protein kinase II, which is hyperactive in heart failure and has been causally linked to cardiac arrhythmia. Understanding the mechanisms of altered NaV1.5 expression and function is crucial for gaining insight into arrhythmogenesis and developing novel therapeutic strategies.
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Affiliation(s)
- Anthony W Herren
- Department of Pharmacology, University of California Davis, Davis, California
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28
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Mao W, You T, Ye B, Li X, Dong HH, Hill JA, Li F, Xu H. Reactive oxygen species suppress cardiac NaV1.5 expression through Foxo1. PLoS One 2012; 7:e32738. [PMID: 22400069 PMCID: PMC3293505 DOI: 10.1371/journal.pone.0032738] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2011] [Accepted: 01/30/2012] [Indexed: 12/17/2022] Open
Abstract
Na(V)1.5 is a cardiac voltage-gated Na(+) channel αsubunit and is encoded by the SCN5a gene. The activity of this channel determines cardiac depolarization and electrical conduction. Channel defects, including mutations and decrease of channel protein levels, have been linked to the development of cardiac arrhythmias. The molecular mechanisms underlying the regulation of Na(V)1.5 expression are largely unknown. Forkhead box O (Foxo) proteins are transcriptional factors that bind the consensus DNA sequences in their target gene promoters and regulate the expression of these genes. Comparative analysis revealed conserved DNA sequences, 5'-CAAAACA-3' (insulin responsive element, IRE), in rat, mouse and human SCN5a promoters with the latter two containing two overlapping Foxo protein binding IREs, 5'-CAAAACAAAACA-3'. This finding led us to hypothesize that Foxo1 regulates Na(V)1.5 expression by directly binding the SCN5a promoter and affecting its transcriptional activity. In the present study, we determined whether Foxo1 regulates Na(V)1.5 expression at the transcriptional level and also defined the role of Foxo1 in hydrogen peroxide (H(2)O(2))-mediated Na(V)1.5 suppression in HL-1 cardiomyocytes using chromatin immunoprecipitation (ChIP), constitutively nuclear Foxo1 expression, and RNAi Foxo1 knockdown as well as whole cell voltage-clamp recordings. ChIP with anti-Foxo1 antibody and follow-up semi-quantitative PCR with primers flanking Foxo1 binding sites in the proximal SCN5a promoter region clearly demonstrated enrichment of DNA, confirming Foxo1 recruitment to this consensus sequence. Foxo1 mutant (T24A/S319A-GFP, Foxo1-AA-GFP) was retained in nuclei, leading to a decrease of Na(V)1.5 expression and Na(+) current, while silencing of Foxo1 expression by RNAi resulted in the augmentation of Na(V)1.5 expression. H(2)O(2) significantly reduced Na(V)1.5 expression by promoting Foxo1 nuclear localization and this reduction was prevented by RNAi silencing Foxo1 expression. These studies indicate that Foxo1 negatively regulates Na(V)1.5 expression in cardiomyocytes and reactive oxygen species suppress Na(V)1.5 expression through Foxo1.
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Affiliation(s)
- Weike Mao
- Department of Pathology and Laboratory Medicine, University of Rochester Medical Center, Rochester, New York, United States of America
| | - Tao You
- Department of Pathology and Laboratory Medicine, University of Rochester Medical Center, Rochester, New York, United States of America
- Division of Cardiology, Second Affiliated Hospital of Soochow University, Suzhou, Jiangsu, People's Republic of China
| | - Bo Ye
- Department of Pathology and Laboratory Medicine, University of Rochester Medical Center, Rochester, New York, United States of America
| | - Xiang Li
- Department of Pathology and Laboratory Medicine, University of Rochester Medical Center, Rochester, New York, United States of America
| | - Henry H. Dong
- Division of Immunogenetics, Rangoes Research Center, Children's Hospital of Pittsburgh of UPMC, Pittsburgh, Pennsylvania, United States of America
| | - Joseph A. Hill
- Division of Cardiology, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America
| | - Faqian Li
- Department of Pathology and Laboratory Medicine, University of Rochester Medical Center, Rochester, New York, United States of America
| | - Haodong Xu
- Department of Pathology and Laboratory Medicine, University of Rochester Medical Center, Rochester, New York, United States of America
- Aab Cardiovascular Research Institute, University of Rochester Medical Center, Rochester, New York, United States of America
- * E-mail:
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Davies SS, Bodine C, Matafonova E, Pantazides BG, Bernoud-Hubac N, Harrison FE, Olson SJ, Montine TJ, Amarnath V, Roberts LJ. Treatment with a γ-ketoaldehyde scavenger prevents working memory deficits in hApoE4 mice. J Alzheimers Dis 2012; 27:49-59. [PMID: 21709376 DOI: 10.3233/jad-2011-102118] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Both inflammation and oxidative injury are features of Alzheimer's disease (AD), but the contribution of these intertwined phenomena to the loss of working memory in this disease is unclear. We tested the hypothesis that highly reactive γ-ketoaldehydes that are formed both by non-enzymatic free radical catalyzed lipid peroxidation and by cyclooxygenases may be causally linked to the development of memory impairment in AD. We found that levels of γ-ketoaldehyde protein adducts were increased in the hippocampus of brains obtained postmortem from patients with AD compared to age-matched controls, but that levels of γ-ketoaldehyde protein adducts in the cerebellum were not different in the two groups. Moreover, immunohistochemistry revealed that adducts localized to hippocampal pyramidal neurons. We tested the effect of an orally available γ-ketoaldehyde scavenger, salicylamine, on the development of spatial working memory deficits in hApoE4 targeted replacement mice, a mouse model of dementia. Long-term salicylamine supplementation did not significantly alter body weight or survival, but protected against the development of age-related deficits in spatial working memory in 12-14 month old ApoE4 mice. These findings suggest that γ-ketoaldehyde adduct formation is associated with damage to hippocampal neurons in patients with AD and can contribute to the pathogenesis of spatial working memory deficits in hApoE4 mice. These data provide a rational basis for future studies exploring whether γ-ketoaldehyde scavengers may mitigate the development of cognitive dysfunction in patients with AD.
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Affiliation(s)
- Sean S Davies
- Division of Clinical Pharmacology, Department of Pharmacology, Vanderbilt Institute of Chemical Biology, Vanderbilt University, Nashville, TN 37232-6602, USA.
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30
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Affiliation(s)
- Ginger L Milne
- Division of Clinical Pharmacology, Vanderbilt University, Nashville, Tennessee 37232-6602, USA.
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Determination of the Pharmacokinetics and Oral Bioavailability of Salicylamine, a Potent γ-Ketoaldehyde Scavenger, by LC/MS/MS. Pharmaceutics 2010; 2:18-29. [PMID: 21822464 PMCID: PMC3150493 DOI: 10.3390/pharmaceutics2010018] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
Abstract
Levels of reactive γ-ketoaldehydes derived from arachidonate increase in diseases associated with inflammation and oxidative injury. To assess the biological importance of these γ-ketoaldehydes, we previously identified salicylamine as an effective γ-ketoaldehyde scavenger in vitro and in cells. To determine if salicylamine could be administered in vivo, we developed an LC/MS/MS assay to measure salicylamine in plasma and tissues. In mice, half-life (t1/2) was 62 minutes. Drinking water supplementation (1-10 g/L) generated tissue concentrations (10-500 μM) within the range previously shown to inhibit γ-ketoaldehydes in cells. Therefore, oral administration of salicylamine can be used to assess the contribution of γ-ketoaldehydes in animal models of disease.
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