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Qian YW, Guo YQ, Li YL, Wang Y, Guo S, Niu QQ, Zhu ML, Li P. The antihypertensive effect of Alizarin is achieved by activating VEGFR2/eNOS pathway, attenuating oxidative stress-induced mitochondrial damage and premature senescence. Life Sci 2024; 351:122862. [PMID: 38917872 DOI: 10.1016/j.lfs.2024.122862] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2024] [Revised: 05/10/2024] [Accepted: 06/18/2024] [Indexed: 06/27/2024]
Abstract
The primary and initial manifestations of hypertension encompass arterial hypoelasticity and histiocyte senescence. Oxidative stress plays a pivotal role in the progression of senescence. Elevated intracellular oxidative stress levels will directly induce cell damage, disrupt normal physiological signal transduction, which can cause mitochondrial dysfunction to accelerate the process of senescence. Alizarin, an anthraquinone active ingredient isolated from Rubia cordifolia L., has a variety of pharmacological effects, including antioxidant, anti-inflammatory and anti-platelet. Nevertheless, its potential in lowering blood pressure (BP) and mitigating hypertension-induced vascular senescence remains uncertain. In this study, we used spontaneously hypertensive rats (SHR) and human umbilical vein endothelial cells (HUVECs) to establish a model of vascular senescence in hypertension. Our aim was to elucidate the mechanisms underpinning the vascular protective effects of Alizarin. By assessing systolic blood pressure (SBP) and diastolic blood pressure (DBP), H&E staining, SA-β-Gal staining, vascular function, oxidative stress levels, calcium ion concentration and mitochondrial membrane potential, we found that Alizarin not only restored SBP and increased endothelium-dependent relaxation (EDR) in SHR, but also inhibited oxidative stress-induced mitochondrial damage and significantly delayed the vascular senescence effect in hypertension, and the mechanism may be related to the activation of VEGFR2/eNOS signaling pathway.
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Affiliation(s)
- Yi-Wen Qian
- Department of Pharmacy, College of Basic Medicine and Forensic Medicine, Henan University of Science and Technology, Luoyang 471000, China
| | - Ya-Qi Guo
- Henan International Joint Laboratory of Cardiovascular Remodeling and Drug Intervention, College of Pharmacy, Xinxiang Medical University, Xinxiang 453003, China
| | - Yin-Lan Li
- College of Pharmacy, Heilongjiang University of Chinese Medicine, Heilongjiang 150040, China
| | - Yang Wang
- Henan International Joint Laboratory of Cardiovascular Remodeling and Drug Intervention, College of Pharmacy, Xinxiang Medical University, Xinxiang 453003, China
| | - Shuang Guo
- Hubei Key Laboratory of Diabetes and Angiopathy, Hubei University of Science and Technology, Xianning 437100, China
| | - Qian-Qian Niu
- Henan International Joint Laboratory of Cardiovascular Remodeling and Drug Intervention, College of Pharmacy, Xinxiang Medical University, Xinxiang 453003, China
| | - Mo-Li Zhu
- Henan International Joint Laboratory of Cardiovascular Remodeling and Drug Intervention, College of Pharmacy, Xinxiang Medical University, Xinxiang 453003, China.
| | - Peng Li
- Henan International Joint Laboratory of Cardiovascular Remodeling and Drug Intervention, College of Pharmacy, Xinxiang Medical University, Xinxiang 453003, China; Hubei Key Laboratory of Diabetes and Angiopathy, Hubei University of Science and Technology, Xianning 437100, China.
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2
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Habecker BA, Bers DM, Birren SJ, Chang R, Herring N, Kay MW, Li D, Mendelowitz D, Mongillo M, Montgomery JM, Ripplinger CM, Tampakakis E, Winbo A, Zaglia T, Zeltner N, Paterson DJ. Molecular and cellular neurocardiology in heart disease. J Physiol 2024. [PMID: 38778747 DOI: 10.1113/jp284739] [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: 02/23/2024] [Accepted: 04/16/2024] [Indexed: 05/25/2024] Open
Abstract
This paper updates and builds on a previous White Paper in this journal that some of us contributed to concerning the molecular and cellular basis of cardiac neurobiology of heart disease. Here we focus on recent findings that underpin cardiac autonomic development, novel intracellular pathways and neuroplasticity. Throughout we highlight unanswered questions and areas of controversy. Whilst some neurochemical pathways are already demonstrating prognostic viability in patients with heart failure, we also discuss the opportunity to better understand sympathetic impairment by using patient specific stem cells that provides pathophysiological contextualization to study 'disease in a dish'. Novel imaging techniques and spatial transcriptomics are also facilitating a road map for target discovery of molecular pathways that may form a therapeutic opportunity to treat cardiac dysautonomia.
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Affiliation(s)
- Beth A Habecker
- Department of Chemical Physiology & Biochemistry, Department of Medicine Knight Cardiovascular Institute, Oregon Health and Science University, Portland, OR, USA
| | - Donald M Bers
- Department of Pharmacology, University of California, Davis School of Medicine, Davis, CA, USA
| | - Susan J Birren
- Department of Biology, Volen Center for Complex Systems, Brandeis University, Waltham, MA, USA
| | - Rui Chang
- Department of Neuroscience, Department of Cellular and Molecular Physiology, Yale University School of Medicine, New Haven, CT, USA
| | - Neil Herring
- Burdon Sanderson Cardiac Science Centre and BHF Centre of Research Excellence, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK
| | - Matthew W Kay
- Department of Biomedical Engineering, George Washington University, Washington, DC, USA
| | - Dan Li
- Burdon Sanderson Cardiac Science Centre and BHF Centre of Research Excellence, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK
| | - David Mendelowitz
- Department of Pharmacology and Physiology, George Washington University, Washington, DC, USA
| | - Marco Mongillo
- Department of Biomedical Sciences, University of Padova, Padova, Italy
| | - Johanna M Montgomery
- Department of Physiology and Manaaki Manawa Centre for Heart Research, University of Auckland, Auckland, New Zealand
| | - Crystal M Ripplinger
- Department of Pharmacology, University of California, Davis School of Medicine, Davis, CA, USA
| | | | - Annika Winbo
- Department of Physiology and Manaaki Manawa Centre for Heart Research, University of Auckland, Auckland, New Zealand
| | - Tania Zaglia
- Department of Biomedical Sciences, University of Padova, Padova, Italy
| | - Nadja Zeltner
- Departments of Biochemistry and Molecular Biology, Cell Biology, and Center for Molecular Medicine, University of Georgia, Athens, GA, USA
| | - David J Paterson
- Burdon Sanderson Cardiac Science Centre and BHF Centre of Research Excellence, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK
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3
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Ohara H, Takeuchi F, Kato N, Nabika T. Genotypes of Stim1 and the proximal region on chromosome 1 exert opposite effects on stroke susceptibility in stroke-prone spontaneously hypertensive rat. J Hypertens 2024; 42:118-128. [PMID: 37711097 DOI: 10.1097/hjh.0000000000003566] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/16/2023]
Abstract
BACKGROUND The stroke-prone spontaneously hypertensive rat (SHRSP) is a genetic model for cerebral stroke. Although a recent study on a congenic SHRSP suggested that a nonsense mutation in stromal interaction molecule 1 ( Stim1 ) encoding a major component of store-operated Ca 2+ entry was a causal variant for stroke in SHRSP, this was not conclusive because the congenic region including Stim1 in that rat was too wide. On the other hand, we demonstrated that the Wistar-Kyoto (WKY)-derived congenic fragment adjacent to Stim1 exacerbated stroke susceptibility in a congenic SHRSP called SPwch1.71. In the present study, we directly examined the effects of the Stim1 genotype on stroke susceptibility using SHRSP in which wild-type Stim1 was knocked in (called Stim1 -KI SHRSP). The combined effects of Stim1 and the congenic fragment of SPwch1.71 were also investigated. METHODS Stroke susceptibility was assessed by the stroke symptom-free and survival periods based on observations of behavioral symptoms and reductions in body weight. RESULTS Stim1 -KI SHRSP was more resistant to, while SPwch1.71 was more susceptible to stroke than the original SHRSP. Introgression of the wild-type Stim1 of Stim1 -KI SHRSP into SPwch1.71 by the generation of F1 rats ameliorated stroke susceptibility in SPwch1.71. Gene expression, whole-genome sequencing, and biochemical analyses identified Art2b , Folr1 , and Pde2a as possible candidate genes accelerating stroke in SPwch1.71. CONCLUSION The substitution of SHRSP-type Stim1 to wild-type Stim1 ameliorated stroke susceptibility in both SHRSP and SPwch1.71, indicating that the nonsense mutation in Stim1 is causally related to stroke susceptibility in SHRSP.
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Affiliation(s)
- Hiroki Ohara
- Department of Functional Pathology, Faculty of Medicine, Shimane University, Izumo
| | - Fumihiko Takeuchi
- Department of Gene Diagnostics and Therapeutics
- Medical Genomics Center, Research Institute, National Center for Global Health and Medicine, Tokyo, Japan
| | - Norihiro Kato
- Department of Gene Diagnostics and Therapeutics
- Medical Genomics Center, Research Institute, National Center for Global Health and Medicine, Tokyo, Japan
| | - Toru Nabika
- Department of Functional Pathology, Faculty of Medicine, Shimane University, Izumo
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4
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Loh D, Reiter RJ. Melatonin: Regulation of Viral Phase Separation and Epitranscriptomics in Post-Acute Sequelae of COVID-19. Int J Mol Sci 2022; 23:8122. [PMID: 35897696 PMCID: PMC9368024 DOI: 10.3390/ijms23158122] [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: 05/25/2022] [Revised: 07/09/2022] [Accepted: 07/20/2022] [Indexed: 01/27/2023] Open
Abstract
The relentless, protracted evolution of the SARS-CoV-2 virus imposes tremendous pressure on herd immunity and demands versatile adaptations by the human host genome to counter transcriptomic and epitranscriptomic alterations associated with a wide range of short- and long-term manifestations during acute infection and post-acute recovery, respectively. To promote viral replication during active infection and viral persistence, the SARS-CoV-2 envelope protein regulates host cell microenvironment including pH and ion concentrations to maintain a high oxidative environment that supports template switching, causing extensive mitochondrial damage and activation of pro-inflammatory cytokine signaling cascades. Oxidative stress and mitochondrial distress induce dynamic changes to both the host and viral RNA m6A methylome, and can trigger the derepression of long interspersed nuclear element 1 (LINE1), resulting in global hypomethylation, epigenetic changes, and genomic instability. The timely application of melatonin during early infection enhances host innate antiviral immune responses by preventing the formation of "viral factories" by nucleocapsid liquid-liquid phase separation that effectively blockades viral genome transcription and packaging, the disassembly of stress granules, and the sequestration of DEAD-box RNA helicases, including DDX3X, vital to immune signaling. Melatonin prevents membrane depolarization and protects cristae morphology to suppress glycolysis via antioxidant-dependent and -independent mechanisms. By restraining the derepression of LINE1 via multifaceted strategies, and maintaining the balance in m6A RNA modifications, melatonin could be the quintessential ancient molecule that significantly influences the outcome of the constant struggle between virus and host to gain transcriptomic and epitranscriptomic dominance over the host genome during acute infection and PASC.
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Affiliation(s)
- Doris Loh
- Independent Researcher, Marble Falls, TX 78654, USA;
| | - Russel J. Reiter
- Department of Cell Systems and Anatomy, UT Health San Antonio, San Antonio, TX 78229, USA
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5
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Davis H, Liu K, Li N, Li D, Paterson DJ. Healthy cardiac myocytes can decrease sympathetic hyperexcitability in the early stages of hypertension. Front Synaptic Neurosci 2022; 14:949150. [PMID: 35989710 PMCID: PMC9386373 DOI: 10.3389/fnsyn.2022.949150] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Accepted: 07/13/2022] [Indexed: 01/08/2023] Open
Abstract
Sympathetic neurons are powerful drivers of cardiac excitability. In the early stages of hypertension, sympathetic hyperactivity is underpinned by down regulation of M current and increased activity of Cav2.2 that is associated with greater intracellular calcium transients and enhanced neurotransmission. Emerging evidence suggests that retrograde signaling from the myocyte itself can modulate synaptic plasticity. Here we tested the hypothesis that cross culturing healthy myocytes onto diseased stellate neurons could influence sympathetic excitability. We employed neuronal mono-cultures, co-cultures of neonatal ventricular myocytes and sympathetic stellate neurons, and mono-cultures of sympathetic neurons with media conditioned by myocytes from normal (Wistar) and pre-hypertensive (SHR) rats, which have heightened sympathetic responsiveness. Neuronal firing properties were measured by current-clamp as a proxy for neuronal excitability. SHR neurons had a maximum higher firing rate, and reduced rheobase compared to Wistar neurons. There was no difference in firing rate or other biophysical properties in Wistar neurons when they were co-cultured with healthy myocytes. However, the firing rate decreased, phenocopying the Wistar response when either healthy myocytes or media in which healthy myocytes were grown was cross-cultured with SHR neurons. This supports the idea of a paracrine signaling pathway from the healthy myocyte to the diseased neuron, which can act as a modulator of sympathetic excitability.
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Affiliation(s)
- Harvey Davis
- Burson Sanderson Cardiac Science Centre, Department of Physiology, Anatomy & Genetics, University of Oxford, Oxford, United Kingdom.,Department of Neuroscience, Physiology & Pharmacology, University College London, London, United Kingdom
| | - Kun Liu
- Burson Sanderson Cardiac Science Centre, Department of Physiology, Anatomy & Genetics, University of Oxford, Oxford, United Kingdom
| | - Ni Li
- Burson Sanderson Cardiac Science Centre, Department of Physiology, Anatomy & Genetics, University of Oxford, Oxford, United Kingdom
| | - Dan Li
- Burson Sanderson Cardiac Science Centre, Department of Physiology, Anatomy & Genetics, University of Oxford, Oxford, United Kingdom
| | - David J Paterson
- Burson Sanderson Cardiac Science Centre, Department of Physiology, Anatomy & Genetics, University of Oxford, Oxford, United Kingdom
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6
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Mondragón-Huerta CG, Bautista-Pérez R, Baiza-Gutman LA, Escobar-Sánchez ML, Valle-Mondragón LD, Salas-Garrido CG, Castro-Moreno P, Ibarra-Barajas M. Morphology and cyclooxygenase-2 and renin expression in the kidney of young spontaneously hypertensive rats. Vet Pathol 2021; 59:371-384. [PMID: 34841988 DOI: 10.1177/03009858211052663] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The kidneys play an important role in blood pressure regulation under normal and pathological conditions. We examined the histological changes and expression patterns of cyclooxygenase-2, renin, and (pro)renin receptor (PRR) in the renal cortex of prehypertensive spontaneously hypertensive rats (SHRs) and Wistar Kyoto rats (WKYs). Moreover, blood pressure and plasma urea, creatinine, angiotensin II, and angiotensin (1-7) levels were measured. The results showed that both strains had similar blood pressure and plasma urea and creatinine levels. The glomerular area, basement membrane thickness, collagen fiber content, and arterial wall thickness were greater in SHRs than in WKYs. By immunohistochemistry, cyclooxygenase-2 was localized in the macula densa and renal tubules of both strains. In SHRs, cyclooxygenase-2 was detected in a larger number of tubules, and the cortical expression of cyclooxygenase-2 was also increased. In both strains, PRR and renin were localized in the tubular epithelium and juxtaglomerular cells, respectively. In SHRs, PRR immunolocalization was increased in the glomerulus. The cortical expression of immature renin was markedly increased in SHRs compared to that in WKYs, while renin was significantly decreased. These changes were associated with higher plasma angiotensin II levels and lower plasma angiotensin (1-7) levels in SHRs. The results indicate that the kidneys of SHRs showed morphological changes and variations in cortical expression patterns of PRR, cyclooxygenase-2, and renin before the development of hypertension.
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Affiliation(s)
| | - Rocío Bautista-Pérez
- Instituto Nacional de Cardiología, "Dr. Ignacio Chávez," Ciudad de México, México
| | - Luis A Baiza-Gutman
- Universidad Nacional Autónoma de México, Tlalnepantla, Estado de México, México
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7
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Odnoshivkina YG, Petrov AM. The Role of Neuro-Cardiac Junctions
in Sympathetic Regulation of the Heart. J EVOL BIOCHEM PHYS+ 2021. [DOI: 10.1134/s0022093021030078] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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8
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Davis H, Herring N, Paterson DJ. Downregulation of M Current Is Coupled to Membrane Excitability in Sympathetic Neurons Before the Onset of Hypertension. Hypertension 2020; 76:1915-1923. [PMID: 33040619 PMCID: PMC8360673 DOI: 10.1161/hypertensionaha.120.15922] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Supplemental Digital Content is available in the text. Neurohumoral activation is an early hallmark of cardiovascular disease and contributes to the etiology of the pathophysiology. Stellectomy has reemerged as a positive therapeutic intervention to modify the progression of dysautonomia, although the biophysical properties underpinning abnormal activity of this ganglia are not fully understood in the initial stages of the disease. We investigated whether stellate ganglia neurons from prehypertensive SHRs (spontaneously hypertensive rats) are hyperactive and describe their electrophysiological phenotype guided by single-cell RNA sequencing, molecular biology, and perforated patch clamp to uncover the mechanism of abnormal excitability. We demonstrate the contribution of a plethora of ion channels, in particular inhibition of M current to stellate ganglia neuronal firing, and confirm the conservation of expression of key ion channel transcripts in human stellate ganglia. We show that hyperexcitability was curbed by M-current activators, nonselective sodium current blockers, or inhibition of Nav1.1-1.3, Nav1.6, or INaP. We conclude that reduced activity of M current contributes significantly to abnormal firing of stellate neurons, which, in part, contributes to the hyperexcitability from rats that have a predisposition to hypertension. Targeting these channels could provide a therapeutic opportunity to minimize the consequences of excessive sympathetic activation.
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Affiliation(s)
- Harvey Davis
- From the Burdon Sanderson Cardiac Science Centre (H.D., N.H., D.J.P.), University of Oxford, United Kingdom.,Department of Physiology, Anatomy and Genetics, Wellcome Trust OXION Initiative in Ion Channels and Disease (H.D., D.J.P.), University of Oxford, United Kingdom
| | - Neil Herring
- From the Burdon Sanderson Cardiac Science Centre (H.D., N.H., D.J.P.), University of Oxford, United Kingdom.,Oxford Heart Centre, Oxford University Hospitals NHS Foundation Trust, John Radcliffe Hospital, United Kingdom (N.H.)
| | - David J Paterson
- From the Burdon Sanderson Cardiac Science Centre (H.D., N.H., D.J.P.), University of Oxford, United Kingdom.,Department of Physiology, Anatomy and Genetics, Wellcome Trust OXION Initiative in Ion Channels and Disease (H.D., D.J.P.), University of Oxford, United Kingdom
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9
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Cheng L, Fu H, Wang X, Ye L, Lakhani I, Tse G, Zhang Z, Liu T, Li G. Effects of ticagrelor pretreatment on electrophysiological properties of stellate ganglion neurons following myocardial infarction. Clin Exp Pharmacol Physiol 2020; 47:1932-1942. [PMID: 33459403 DOI: 10.1111/1440-1681.13385] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2019] [Revised: 06/21/2020] [Accepted: 07/15/2020] [Indexed: 12/26/2022]
Abstract
Higher sympathetic activity predisposes to malignant ventricular arrhythmias in the context of myocardial infarction (MI). This is, in part, mediated by the electrical activity of the stellate ganglion (SG). The aim of this study is to examine the effects of ticagrelor pretreatment on the electrophysiological properties of SG neurons following MI in rabbits. MI was induced by isoproterenol (ISO) of 150 mg kg-1 d-1 (twice at an interval of 24 hours). Ticagrelor pretreatment was administered at low- (10 mg kg-1 d-1) or high-dose (20 mg kg-1 d-1). Protein and RNA expression were determined by immunohistochemical analysis and real-time PCR, respectively. The activity of sodium channel current (INa), delayed rectifier potassium current (IKDR), M-type potassium current (IKM) as well as action potentials (APs) from SG neurons were measured by whole-cell patch-clamp. Intracellular calcium concentrations were measured by confocal microscopy. Compared with the control group, the MI group exhibited a greater amplitude of INa, IKDR and IKM, significantly altered activation and inactivation characteristics of INa, no significant alterations in protein or mRNA expression of sodium and M-type potassium channels, along with higher AP amplitude and frequency and intracellular calcium concentrations. Most of these abnormalities were prevented by pretreatment with low- or high-dose ticagrelor. Our data suggest that ticagrelor exerts cardioprotective effects, potentially through modulating the activity of different ion channels in SG neurons.
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Affiliation(s)
- Lijun Cheng
- Tianjin Key Laboratory of Ionic-Molecular Function of Cardiovascular Disease, Department of Cardiology, Tianjin Institute of Cardiology, the Second Hospital of Tianjin Medical University, Tianjin, China
| | - Huaying Fu
- Tianjin Key Laboratory of Ionic-Molecular Function of Cardiovascular Disease, Department of Cardiology, Tianjin Institute of Cardiology, the Second Hospital of Tianjin Medical University, Tianjin, China
| | - Xinghua Wang
- Tianjin Key Laboratory of Ionic-Molecular Function of Cardiovascular Disease, Department of Cardiology, Tianjin Institute of Cardiology, the Second Hospital of Tianjin Medical University, Tianjin, China
| | - Lan Ye
- Tianjin Key Laboratory of Ionic-Molecular Function of Cardiovascular Disease, Department of Cardiology, Tianjin Institute of Cardiology, the Second Hospital of Tianjin Medical University, Tianjin, China
| | - Ishan Lakhani
- Laboratory of Cardiovascular Physiology, Li Ka Shing Institute of Health Sciences, Hong Kong, China
| | - Gary Tse
- Tianjin Key Laboratory of Ionic-Molecular Function of Cardiovascular Disease, Department of Cardiology, Tianjin Institute of Cardiology, the Second Hospital of Tianjin Medical University, Tianjin, China
| | - Zhiwei Zhang
- Tianjin Key Laboratory of Ionic-Molecular Function of Cardiovascular Disease, Department of Cardiology, Tianjin Institute of Cardiology, the Second Hospital of Tianjin Medical University, Tianjin, China
| | - Tong Liu
- Tianjin Key Laboratory of Ionic-Molecular Function of Cardiovascular Disease, Department of Cardiology, Tianjin Institute of Cardiology, the Second Hospital of Tianjin Medical University, Tianjin, China
| | - Guangping Li
- Tianjin Key Laboratory of Ionic-Molecular Function of Cardiovascular Disease, Department of Cardiology, Tianjin Institute of Cardiology, the Second Hospital of Tianjin Medical University, Tianjin, China
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10
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Bardsley EN, Paterson DJ. Neurocardiac regulation: from cardiac mechanisms to novel therapeutic approaches. J Physiol 2020; 598:2957-2976. [PMID: 30307615 PMCID: PMC7496613 DOI: 10.1113/jp276962] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2018] [Accepted: 10/02/2018] [Indexed: 12/15/2022] Open
Abstract
Cardiac sympathetic overactivity is a well-established contributor to the progression of neurogenic hypertension and heart failure, yet the underlying pathophysiology remains unclear. Recent studies have highlighted the importance of acutely regulated cyclic nucleotides and their effectors in the control of intracellular calcium and exocytosis. Emerging evidence now suggests that a significant component of sympathetic overactivity and enhanced transmission may arise from impaired cyclic nucleotide signalling, resulting from compromised phosphodiesterase activity, as well as alterations in receptor-coupled G-protein activation. In this review, we address some of the key cellular and molecular pathways that contribute to sympathetic overactivity in hypertension and discuss their potential for therapeutic targeting.
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Affiliation(s)
- E. N. Bardsley
- Wellcome Trust OXION Initiative in Ion Channels and DiseaseOxfordUK
- Burdon Sanderson Cardiac Science Centre, Department of PhysiologyAnatomy and Genetics, University of OxfordOxfordOX1 3PTUK
| | - D. J. Paterson
- Wellcome Trust OXION Initiative in Ion Channels and DiseaseOxfordUK
- Burdon Sanderson Cardiac Science Centre, Department of PhysiologyAnatomy and Genetics, University of OxfordOxfordOX1 3PTUK
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11
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Angiotensin peptide synthesis and cyclic nucleotide modulation in sympathetic stellate ganglia. J Mol Cell Cardiol 2019; 138:234-243. [PMID: 31836539 PMCID: PMC7049903 DOI: 10.1016/j.yjmcc.2019.11.157] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Revised: 11/25/2019] [Accepted: 11/26/2019] [Indexed: 12/12/2022]
Abstract
Chronically elevated angiotensin II is a widely-established contributor to hypertension and heart failure via its action on the kidneys and vasculature. It also augments the activity of peripheral sympathetic nerves through activation of presynaptic angiotensin II receptors, thus contributing to sympathetic over-activity. Although some cells can synthesise angiotensin II locally, it is not known if this machinery is present in neurons closely coupled to the heart. Using a combination of RNA sequencing and quantitative real-time polymerase chain reaction, we demonstrate evidence for a renin-angiotensin synthesis pathway within human and rat sympathetic stellate ganglia, where significant alterations were observed in the spontaneously hypertensive rat stellate ganglia compared with Wistar stellates. We also used Förster Resonance Energy Transfer to demonstrate that administration of angiotensin II and angiotensin 1-7 peptides significantly elevate cyclic guanosine monophosphate in the rat stellate ganglia. Whether the release of angiotensin peptides from the sympathetic stellate ganglia alters neurotransmission and/or exacerbates cardiac dysfunction in states associated with sympathetic over activity remains to be established.
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12
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Studying β 1 and β 2 adrenergic receptor signals in cardiac cells using FRET-based sensors. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2019; 154:30-38. [PMID: 31266653 DOI: 10.1016/j.pbiomolbio.2019.06.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 03/20/2019] [Revised: 06/10/2019] [Accepted: 06/17/2019] [Indexed: 12/17/2022]
Abstract
Cyclic 3'-5' adenosine monophosphate (cAMP) is a key modulator of cardiac function. Thanks to the sophisticated organization of its pathway in distinct functional units called microdomains, cAMP is involved in the regulation of both inotropy and chronotropy as well as transcription and cardiac death. While visualization of cAMP microdomains can be achieved thanks to cAMP-sensitive FRET-based sensors, the molecular mechanisms through which cAMP-generating stimuli are coupled to distinct functional outcomes are not well understood. One possibility is that each stimulus activates multiple microdomains in order to generate a spatiotemporal code that translates into function. To test this hypothesis here we propose a series of experimental protocols that allow to simultaneously follow cAMP or Protein Kinase A (PKA)-dependent phosphorylation in different subcellular compartments of living cells. We investigate the responses of β Adrenergic receptors (β1AR and β2AR) challenged with selective drugs that enabled us to measure the actions of each receptor independently. At the whole cell level, we used a combination of co-culture with selective βAR stimulation and were able to molecularly separate cardiac fibroblasts from neonatal rat ventricular myocytes based on their cAMP responses. On the other hand, at the subcellular level, these experimental protocols allowed us to dissect the relative weight of β1 and β2 adrenergic receptors on cAMP signalling at the cytosol and outer mitochondrial membrane of NRVMs. We propose that experimental procedures that allow the collection of multiparametric data are necessary in order to understand the molecular mechanisms underlying the coupling between extracellular signals and cellular responses.
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13
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The autonomic nervous system and cardiac arrhythmias: current concepts and emerging therapies. Nat Rev Cardiol 2019; 16:707-726. [DOI: 10.1038/s41569-019-0221-2] [Citation(s) in RCA: 77] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 05/07/2019] [Indexed: 12/19/2022]
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14
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Li D, Paterson DJ. Pre-synaptic sympathetic calcium channels, cyclic nucleotide-coupled phosphodiesterases and cardiac excitability. Semin Cell Dev Biol 2019; 94:20-27. [PMID: 30658154 DOI: 10.1016/j.semcdb.2019.01.010] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2018] [Revised: 01/07/2019] [Accepted: 01/14/2019] [Indexed: 12/20/2022]
Abstract
In sympathetic neurons innervating the heart, action potentials activate voltage-gated Ca2+ channels and evoke Ca2+ entry into presynaptic terminals triggering neurotransmitter release. Binding of transmitters to specific receptors stimulates signal transduction pathways that cause changes in cardiac function. The mechanisms contributing to presynaptic Ca2+ dynamics involve regulation of endogenous Ca2+ buffers, in particular the endoplasmic reticulum, mitochondria and cyclic nucleotide targeted pathways. The purpose of this review is to summarize and highlight recent findings about Ca2+ homeostasis in cardiac sympathetic neurons and how modulation of second messengers can drive neurotransmission and affect myocyte excitability in cardiovascular disease. Moreover, we discuss the underlying mechanism of abnormal intracellular Ca2+ homeostasis and signaling in these neurons, and speculate on the role of phosphodiesterases as a therapeutic target to restore normal autonomic transmission in disease states of overactivity.
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Affiliation(s)
- Dan Li
- Burdon Sanderson Cardiac Science Centre, Department of Physiology, Anatomy and Genetics, Sherrington Building, University of Oxford, Parks Road, Oxford, OX1 3PT, UK.
| | - David J Paterson
- Burdon Sanderson Cardiac Science Centre, Department of Physiology, Anatomy and Genetics, Sherrington Building, University of Oxford, Parks Road, Oxford, OX1 3PT, UK.
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15
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Vinogradova TM, Kobrinsky E, Lakatta EG. Dual Activation of Phosphodiesterases 3 and 4 Regulates Basal Spontaneous Beating Rate of Cardiac Pacemaker Cells: Role of Compartmentalization? Front Physiol 2018; 9:1301. [PMID: 30356755 PMCID: PMC6189467 DOI: 10.3389/fphys.2018.01301] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2018] [Accepted: 08/29/2018] [Indexed: 12/17/2022] Open
Abstract
Spontaneous firing of sinoatrial (SA) node cells (SANCs) is regulated by cyclic adenosine monophosphate (cAMP)-mediated, protein kinase A (PKA)-dependent (cAMP/PKA) local subsarcolemmal Ca2+ releases (LCRs) from ryanodine receptors (RyR). The LCRs occur during diastolic depolarization (DD) and activate an inward Na+/Ca2+ exchange current that accelerates the DD rate prompting the next action potential (AP). Basal phosphodiesterases (PDEs) activation degrades cAMP, reduces basal cAMP/PKA-dependent phosphorylation, and suppresses normal spontaneous firing of SANCs. The cAMP-degrading PDE1, PDE3, and PDE4 represent major PDE activities in rabbit SANC, and PDE inhibition by 3-isobutyl-1-methylxanthine (IBMX) increases spontaneous firing of SANC by ∼50%. Though inhibition of single PDE1–PDE4 only moderately increases spontaneous SANC firing, dual PDE3 + PDE4 inhibition produces a synergistic effect hastening the spontaneous SANC beating rate by ∼50%. Here, we describe the expression and distribution of different PDE subtypes within rabbit SANCs, several specific targets (L-type Ca2+ channels and phospholamban) regulated by basal concurrent PDE3 + PDE4 activation, and critical importance of RyR Ca2+ releases for PDE-dependent regulation of spontaneous SANC firing. Colocalization of PDE3 and PDE4 beneath sarcolemma or in striated patterns inside SANCs strongly suggests that PDE-dependent regulation of cAMP/PKA signaling might be executed at the local level; this idea, however, requires further verification.
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Affiliation(s)
- Tatiana M Vinogradova
- Laboratory of Cardiovascular Science, Intramural Research Program, NIA, NIH, Baltimore, MD, United States
| | - Evgeny Kobrinsky
- Laboratory of Cardiovascular Science, Intramural Research Program, NIA, NIH, Baltimore, MD, United States
| | - Edward G Lakatta
- Laboratory of Cardiovascular Science, Intramural Research Program, NIA, NIH, Baltimore, MD, United States
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16
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Cheng L, Wang X, Liu T, Tse G, Fu H, Li G. Modulation of Ion Channels in the Superior Cervical Ganglion Neurons by Myocardial Ischemia and Fluvastatin Treatment. Front Physiol 2018; 9:1157. [PMID: 30246810 PMCID: PMC6139347 DOI: 10.3389/fphys.2018.01157] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2018] [Accepted: 08/02/2018] [Indexed: 01/08/2023] Open
Abstract
Background: The superior cervical ganglion (SCG) of the autonomic nervous system plays an important role in different cardiovascular diseases. In this study, we investigated the effects of ischemia and fluvastatin treatment on the ion channel characteristics of SCG neurons in a rabbit myocardial ischemia (MI) model. Methods: MI was induced by abdominal subcutaneous injections of isoproterenol (ISO). The properties of the delayed rectifier potassium channel current (IK), sodium channel current (INa), and action potential (APs) on isolated SCG neurons in the control, MI-7d, MI-14d, fluvastatin-7d (fluvastatin pretreated 14 days and treated 7 days after ISO-induced MI), and fluvastatin-14d (fluvastatin pretreated 14 days and treated 14 days after ISO-induced MI) groups were studied. In addition, the RNA expressions of KCNQ3 and SCN9A in the SCG tissue were determined by performing real-time PCR. Intracellular calcium concentration was monitored using laser scanning confocal microscopy. Results: Compared with the control group, the current amplitude of IK and INa were increased in the MI-7d and MI-14d groups. KCNQ3 RNA (corresponding to channel proteins of IK) expression and SCN9A RNA (corresponding to channel proteins of INa) expression were also increased in MI groups. Activation and inactivation curves for INa in the two MI groups shifted negatively compared with the control group. These changes were reversed by fluvastatin treatment. Intracellular calcium concentration in SCG neurons was not altered significantly by MI or fluvastatin treatment. By contrast, increased AP amplitude and shortened APD90 were observed in the MI-7d and MI-14d groups. These changes were reversed in the fluvastatin-treated MI group. Conclusion: Fluvastatin treatment partly reversed the characteristics of SCG neurons in MI. The ion channel of SCG neurons could be one of the potential targets of fluvastatin in treating coronary heart diseases.
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Affiliation(s)
- Lijun Cheng
- Department of Cardiology, Tianjin Key Laboratory of Ionic-Molecular Function of Cardiovascular Disease, Tianjin Institute of Cardiology, The Second Hospital of Tianjin Medical University, Tianjin, China
| | - Xinghua Wang
- Department of Cardiology, Tianjin Key Laboratory of Ionic-Molecular Function of Cardiovascular Disease, Tianjin Institute of Cardiology, The Second Hospital of Tianjin Medical University, Tianjin, China
| | - Tong Liu
- Department of Cardiology, Tianjin Key Laboratory of Ionic-Molecular Function of Cardiovascular Disease, Tianjin Institute of Cardiology, The Second Hospital of Tianjin Medical University, Tianjin, China
| | - Gary Tse
- Department of Medicine and Therapeutics, The Chinese University of Hong Kong, Shatin, Hong Kong.,Li Ka Shing Institute of Health Sciences, The Chinese University of Hong Kong, Shatin, Hong Kong
| | - Huaying Fu
- Department of Cardiology, Tianjin Key Laboratory of Ionic-Molecular Function of Cardiovascular Disease, Tianjin Institute of Cardiology, The Second Hospital of Tianjin Medical University, Tianjin, China
| | - Guangping Li
- Department of Cardiology, Tianjin Key Laboratory of Ionic-Molecular Function of Cardiovascular Disease, Tianjin Institute of Cardiology, The Second Hospital of Tianjin Medical University, Tianjin, China
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17
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Phosphatases control PKA-dependent functional microdomains at the outer mitochondrial membrane. Proc Natl Acad Sci U S A 2018; 115:E6497-E6506. [PMID: 29941564 PMCID: PMC6048485 DOI: 10.1073/pnas.1806318115] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
The selective phosphorylation of spatially distinct PKA targets is key for the pleiotropy of the cAMP cascade. This characteristic of the pathway is currently attributed to the ability of phosphodiesterases or adenylate cyclases to create subcellular sites (microdomains) where the concentration of cAMP is distinct from that of the surrounding areas. The role of phosphatases in this process has not been tested. Here we show that limited access of phosphatases to the PKA targets present at the outer mitochondrial membrane generates distinct microdomains of PKA phosphorylated proteins despite there being no differences in the local cAMP levels. These results describe an alternative mechanism capable of generating functional cAMP/PKA-dependent microdomains and may be extrapolated to the compartmentalization of other kinase-dependent events. Evidence supporting the heterogeneity in cAMP and PKA signaling is rapidly accumulating and has been largely attributed to the localization or activity of adenylate cyclases, phosphodiesterases, and A-kinase–anchoring proteins in different cellular subcompartments. However, little attention has been paid to the possibility that, despite homogeneous cAMP levels, a major heterogeneity in cAMP/PKA signaling could be generated by the spatial distribution of the final terminators of this cascade, i.e., the phosphatases. Using FRET-based sensors to monitor cAMP and PKA-dependent phosphorylation in the cytosol and outer mitochondrial membrane (OMM) of primary rat cardiomyocytes, we demonstrate that comparable cAMP increases in these two compartments evoke higher levels of PKA-dependent phosphorylation in the OMM. This difference is most evident for small, physiological increases of cAMP levels and with both OMM-located probes and endogenous OMM proteins. We demonstrate that this disparity depends on differences in the rates of phosphatase-dependent dephosphorylation of PKA targets in the two compartments. Furthermore, we show that the activity of soluble phosphatases attenuates PKA-driven activation of the cAMP response element-binding protein while concurrently enhancing PKA-dependent mitochondrial elongation. We conclude that phosphatases can sculpt functionally distinct cAMP/PKA domains even in the absence of gradients or microdomains of this messenger. We present a model that accounts for these unexpected results in which the degree of PKA-dependent phosphorylation is dictated by both the subcellular distribution of the phosphatases and the different accessibility of membrane-bound and soluble phosphorylated substrates to the cytosolic enzymes.
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18
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Bardsley EN, Davis H, Ajijola OA, Buckler KJ, Ardell JL, Shivkumar K, Paterson DJ. RNA Sequencing Reveals Novel Transcripts from Sympathetic Stellate Ganglia During Cardiac Sympathetic Hyperactivity. Sci Rep 2018; 8:8633. [PMID: 29872217 PMCID: PMC5988725 DOI: 10.1038/s41598-018-26651-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2018] [Accepted: 05/15/2018] [Indexed: 12/15/2022] Open
Abstract
Cardiovascular disease is the most prevalent age-related illness worldwide, causing approximately 15 million deaths every year. Hypertension is central in determining cardiovascular risk and is a strong predictive indicator of morbidity and mortality; however, there remains an unmet clinical need for disease-modifying and prophylactic interventions. Enhanced sympathetic activity is a well-established contributor to the pathophysiology of hypertension, however the cellular and molecular changes that increase sympathetic neurotransmission are not known. The aim of this study was to identify key changes in the transcriptome in normotensive and spontaneously hypertensive rats. We validated 15 of our top-scoring genes using qRT-PCR, and network and enrichment analyses suggest that glutamatergic signalling plays a key role in modulating Ca2+ balance within these ganglia. Additionally, phosphodiesterase activity was found to be altered in stellates obtained from the hypertensive rat, suggesting that impaired cyclic nucleotide signalling may contribute to disturbed Ca2+ homeostasis and sympathetic hyperactivity in hypertension. We have also confirmed the presence of these transcripts in human donor stellate samples, suggesting that key genes coupled to neurotransmission are conserved. The data described here may provide novel targets for future interventions aimed at treating sympathetic hyperactivity associated with cardiovascular disease and other dysautonomias.
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Affiliation(s)
- Emma N Bardsley
- Wellcome Trust OXION Initiative in Ion Channels and Disease, Burdon Sanderson Cardiac Science Centre, Department of Physiology, Anatomy and Genetics, Sherrington Building, University of Oxford, Oxford, OX1 3PT, UK.
| | - Harvey Davis
- Wellcome Trust OXION Initiative in Ion Channels and Disease, Burdon Sanderson Cardiac Science Centre, Department of Physiology, Anatomy and Genetics, Sherrington Building, University of Oxford, Oxford, OX1 3PT, UK
| | - Olujimi A Ajijola
- UCLA Cardiac Arrhythmia Center, 100 Medical Plaza, Suite 660, Los Angeles, CA, 90095, USA
| | - Keith J Buckler
- Wellcome Trust OXION Initiative in Ion Channels and Disease, Burdon Sanderson Cardiac Science Centre, Department of Physiology, Anatomy and Genetics, Sherrington Building, University of Oxford, Oxford, OX1 3PT, UK
| | - Jeffrey L Ardell
- UCLA Cardiac Arrhythmia Center, 100 Medical Plaza, Suite 660, Los Angeles, CA, 90095, USA
| | - Kalyanam Shivkumar
- UCLA Cardiac Arrhythmia Center, 100 Medical Plaza, Suite 660, Los Angeles, CA, 90095, USA
| | - David J Paterson
- Wellcome Trust OXION Initiative in Ion Channels and Disease, Burdon Sanderson Cardiac Science Centre, Department of Physiology, Anatomy and Genetics, Sherrington Building, University of Oxford, Oxford, OX1 3PT, UK.
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19
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Bardsley EN, Davis H, Buckler KJ, Paterson DJ. Neurotransmitter Switching Coupled to β-Adrenergic Signaling in Sympathetic Neurons in Prehypertensive States. Hypertension 2018; 71:1226-1238. [PMID: 29686017 PMCID: PMC5959210 DOI: 10.1161/hypertensionaha.118.10844] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2018] [Revised: 01/18/2018] [Accepted: 03/26/2018] [Indexed: 01/16/2023]
Abstract
Single or combinatorial administration of β-blockers is a mainstay treatment strategy for conditions caused by sympathetic overactivity. Conventional wisdom suggests that the main beneficial effect of β-blockers includes resensitization and restoration of β1-adrenergic signaling pathways in the myocardium, improvements in cardiomyocyte contractility, and reversal of ventricular sensitization. However, emerging evidence indicates that another beneficial effect of β-blockers in disease may reside in sympathetic neurons. We investigated whether β-adrenoceptors are present on postganglionic sympathetic neurons and facilitate neurotransmission in a feed-forward manner. Using a combination of immunocytochemistry, RNA sequencing, Förster resonance energy transfer, and intracellular Ca2+ imaging, we demonstrate the presence of β-adrenoceptors on presynaptic sympathetic neurons in both human and rat stellate ganglia. In diseased neurons from the prehypertensive rat, there was enhanced β-adrenoceptor-mediated signaling predominantly via β2-adrenoceptor activation. Moreover, in human and rat neurons, we identified the presence of the epinephrine-synthesizing enzyme PNMT (phenylethanolamine-N-methyltransferase). Using high-pressure liquid chromatography with electrochemical detection, we measured greater epinephrine content and evoked release from the prehypertensive rat cardiac-stellate ganglia. We conclude that neurotransmitter switching resulting in enhanced epinephrine release, may provide presynaptic positive feedback on β-adrenoceptors to promote further release, that leads to greater postsynaptic excitability in disease, before increases in arterial blood pressure. Targeting neuronal β-adrenoceptor downstream signaling could provide therapeutic opportunity to minimize end-organ damage caused by sympathetic overactivity.
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Affiliation(s)
- Emma N Bardsley
- From the Wellcome Trust OXION Initiative in Ion Channels and Disease, Burdon Sanderson Cardiac Science Centre, Department of Physiology, Anatomy and Genetics, University of Oxford, United Kingdom.
| | - Harvey Davis
- From the Wellcome Trust OXION Initiative in Ion Channels and Disease, Burdon Sanderson Cardiac Science Centre, Department of Physiology, Anatomy and Genetics, University of Oxford, United Kingdom
| | - Keith J Buckler
- From the Wellcome Trust OXION Initiative in Ion Channels and Disease, Burdon Sanderson Cardiac Science Centre, Department of Physiology, Anatomy and Genetics, University of Oxford, United Kingdom
| | - David J Paterson
- From the Wellcome Trust OXION Initiative in Ion Channels and Disease, Burdon Sanderson Cardiac Science Centre, Department of Physiology, Anatomy and Genetics, University of Oxford, United Kingdom.
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20
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Liu K, Li D, Hao G, McCaffary D, Neely O, Woodward L, Ioannides D, Lu CJ, Brescia M, Zaccolo M, Tandri H, Ajijola OA, Ardell JL, Shivkumar K, Paterson DJ. Phosphodiesterase 2A as a therapeutic target to restore cardiac neurotransmission during sympathetic hyperactivity. JCI Insight 2018; 3:98694. [PMID: 29720569 DOI: 10.1172/jci.insight.98694] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2017] [Accepted: 04/05/2018] [Indexed: 12/17/2022] Open
Abstract
Elevated levels of brain natriuretic peptide (BNP) are regarded as an early compensatory response to cardiac myocyte hypertrophy, although exogenously administered BNP shows poor clinical efficacy in heart failure and hypertension. We tested whether phosphodiesterase 2A (PDE2A), which regulates the action of BNP-activated cyclic guanosine monophosphate (cGMP), was directly involved in modulating Ca2+ handling from stellate ganglia (SG) neurons and cardiac norepinephrine (NE) release in rats and humans with an enhanced sympathetic phenotype. SG were also isolated from patients with sympathetic hyperactivity and healthy donor patients. PDE2A activity of the SG was greater in both spontaneously hypertensive rats (SHRs) and patients compared with their respective controls, whereas PDE2A mRNA was only high in SHR SG. BNP significantly reduced the magnitude of the calcium transients and ICaN in normal Wistar Kyoto (WKY) SG neurons, but not in the SHRs. cGMP levels stimulated by BNP were also attenuated in SHR SG neurons. Overexpression of PDE2A in WKY neurons recapitulated the calcium phenotype seen in SHR neurons. Functionally, BNP significantly reduced [3H]-NE release in the WKY rats, but not in the SHRs. Blockade of overexpressed PDE2A with Bay 60-7550 or overexpression of catalytically inactive PDE2A reestablished the modulatory action of BNP in SHR SG neurons. This suggests that PDE2A may be a key target in modulating the action of BNP to reduce sympathetic hyperactivity.
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Affiliation(s)
- Kun Liu
- Burdon Sanderson Cardiac Science Centre and BHF Centre of Research Excellence, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
| | - Dan Li
- Burdon Sanderson Cardiac Science Centre and BHF Centre of Research Excellence, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
| | - Guoliang Hao
- Burdon Sanderson Cardiac Science Centre and BHF Centre of Research Excellence, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
| | - David McCaffary
- Burdon Sanderson Cardiac Science Centre and BHF Centre of Research Excellence, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
| | - Oliver Neely
- Burdon Sanderson Cardiac Science Centre and BHF Centre of Research Excellence, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
| | - Lavinia Woodward
- Burdon Sanderson Cardiac Science Centre and BHF Centre of Research Excellence, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
| | - Demetris Ioannides
- Burdon Sanderson Cardiac Science Centre and BHF Centre of Research Excellence, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
| | - Chieh-Ju Lu
- Burdon Sanderson Cardiac Science Centre and BHF Centre of Research Excellence, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
| | - Marcella Brescia
- Burdon Sanderson Cardiac Science Centre and BHF Centre of Research Excellence, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
| | - Manuela Zaccolo
- Burdon Sanderson Cardiac Science Centre and BHF Centre of Research Excellence, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
| | - Harikrishna Tandri
- Division of Cardiology, Department of Medicine, Johns Hopkins University, Baltimore, Maryland, USA
| | - Olujimi A Ajijola
- UCLA Cardiac Arrhythmia Center, David Geffen School of Medicine, UCLA Health System, Los Angeles, California, USA
| | - Jeffrey L Ardell
- UCLA Cardiac Arrhythmia Center, David Geffen School of Medicine, UCLA Health System, Los Angeles, California, USA
| | - Kalyanam Shivkumar
- UCLA Cardiac Arrhythmia Center, David Geffen School of Medicine, UCLA Health System, Los Angeles, California, USA
| | - David J Paterson
- Burdon Sanderson Cardiac Science Centre and BHF Centre of Research Excellence, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
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21
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Ashton JL, Burton RAB, Bub G, Smaill BH, Montgomery JM. Synaptic Plasticity in Cardiac Innervation and Its Potential Role in Atrial Fibrillation. Front Physiol 2018; 9:240. [PMID: 29615932 PMCID: PMC5869186 DOI: 10.3389/fphys.2018.00240] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2017] [Accepted: 03/06/2018] [Indexed: 12/30/2022] Open
Abstract
Synaptic plasticity is defined as the ability of synapses to change their strength of transmission. Plasticity of synaptic connections in the brain is a major focus of neuroscience research, as it is the primary mechanism underpinning learning and memory. Beyond the brain however, plasticity in peripheral neurons is less well understood, particularly in the neurons innervating the heart. The atria receive rich innervation from the autonomic branch of the peripheral nervous system. Sympathetic neurons are clustered in stellate and cervical ganglia alongside the spinal cord and extend fibers to the heart directly innervating the myocardium. These neurons are major drivers of hyperactive sympathetic activity observed in heart disease, ventricular arrhythmias, and sudden cardiac death. Both pre- and postsynaptic changes have been observed to occur at synapses formed by sympathetic ganglion neurons, suggesting that plasticity at sympathetic neuro-cardiac synapses is a major contributor to arrhythmias. Less is known about the plasticity in parasympathetic neurons located in clusters on the heart surface. These neuronal clusters, termed ganglionated plexi, or “little brains,” can independently modulate neural control of the heart and stimulation that enhances their excitability can induce arrhythmia such as atrial fibrillation. The ability of these neurons to alter parasympathetic activity suggests that plasticity may indeed occur at the synapses formed on and by ganglionated plexi neurons. Such changes may not only fine-tune autonomic innervation of the heart, but could also be a source of maladaptive plasticity during atrial fibrillation.
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Affiliation(s)
- Jesse L Ashton
- Department of Physiology, University of Auckland, Auckland, New Zealand
| | | | - Gil Bub
- Department of Physiology, McGill University, Montreal, QC, Canada
| | - Bruce H Smaill
- Department of Physiology, University of Auckland, Auckland, New Zealand.,Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand
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22
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Abstract
Hypertension is a prevalent and major health problem, involving a complex integration of different organ systems, including the central nervous system (CNS). The CNS and the hypothalamus in particular are intricately involved in the pathogenesis of hypertension. In fact, evidence supports altered hypothalamic neuronal activity as a major factor contributing to increased sympathetic drive and increased blood pressure. Several mechanisms have been proposed to contribute to hypothalamic-driven sympathetic activity, including altered ion channel function. Ion channels are critical regulators of neuronal excitability and synaptic function in the brain and, thus, important for blood pressure homeostasis regulation. These include sodium channels, voltage-gated calcium channels, and potassium channels being some of them already identified in hypothalamic neurons. This brief review summarizes the hypothalamic ion channels that may be involved in hypertension, highlighting recent findings that suggest that hypothalamic ion channel modulation can affect the central control of blood pressure and, therefore, suggesting future development of interventional strategies designed to treat hypertension.
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Affiliation(s)
- Vera Geraldes
- Instituto de Fisiologia, Universidade de Lisboa, Faculdade de Medicina, Universidade de Lisboa, Avenida Professor Egas Moniz, 1649-028, Lisbon, Portugal
| | - Sérgio Laranjo
- Instituto de Fisiologia, Universidade de Lisboa, Faculdade de Medicina, Universidade de Lisboa, Avenida Professor Egas Moniz, 1649-028, Lisbon, Portugal
| | - Isabel Rocha
- Instituto de Fisiologia, Universidade de Lisboa, Faculdade de Medicina, Universidade de Lisboa, Avenida Professor Egas Moniz, 1649-028, Lisbon, Portugal. .,Centro Cardiovascular da Universidade de Lisboa, Universidade de Lisboa, Avenida Professor Egas Moniz, 1649-028, Lisbon, Portugal.
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23
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Sympathetic neurons are a powerful driver of myocyte function in cardiovascular disease. Sci Rep 2016; 6:38898. [PMID: 27966588 PMCID: PMC5155272 DOI: 10.1038/srep38898] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2016] [Accepted: 11/15/2016] [Indexed: 01/23/2023] Open
Abstract
Many therapeutic interventions in disease states of heightened cardiac sympathetic activity are targeted to the myocytes. However, emerging clinical data highlights a dominant role in disease progression by the neurons themselves. Here we describe a novel experimental model of the peripheral neuro-cardiac axis to study the neuron’s ability to drive a myocyte cAMP phenotype. We employed a co-culture of neonatal ventricular myocytes and sympathetic stellate neurons from normal (WKY) and pro-hypertensive (SHR) rats that are sympathetically hyper-responsive and measured nicotine evoked cAMP responses in the myocytes using a fourth generation FRET cAMP sensor. We demonstrated the dominant role of neurons in driving the myocyte ß-adrenergic phenotype, where SHR cultures elicited heightened myocyte cAMP responses during neural activation. Moreover, cross-culturing healthy neurons onto diseased myocytes rescued the diseased cAMP response of the myocyte. Conversely, healthy myocytes developed a diseased cAMP response if diseased neurons were introduced. Our results provide evidence for a dominant role played by the neuron in driving the adrenergic phenotype seen in cardiovascular disease. We also highlight the potential of using healthy neurons to turn down the gain of neurotransmission, akin to a smart pre-synaptic ß-blocker.
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24
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Bardsley EN, Larsen HE, Paterson DJ. Impaired cAMP-cGMP cross-talk during cardiac sympathetic dysautonomia. Channels (Austin) 2016; 11:178-180. [PMID: 27835060 DOI: 10.1080/19336950.2016.1259040] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Affiliation(s)
- Emma N Bardsley
- a Wellcome Trust OXION Initiative in Ion Channels and Disease , Oxford , UK.,b Burdon Sanderson Cardiac Science Center, Department of Physiology , Anatomy and Genetics, University of Oxford , Oxford , UK
| | - Hege E Larsen
- a Wellcome Trust OXION Initiative in Ion Channels and Disease , Oxford , UK.,b Burdon Sanderson Cardiac Science Center, Department of Physiology , Anatomy and Genetics, University of Oxford , Oxford , UK
| | - David J Paterson
- a Wellcome Trust OXION Initiative in Ion Channels and Disease , Oxford , UK.,b Burdon Sanderson Cardiac Science Center, Department of Physiology , Anatomy and Genetics, University of Oxford , Oxford , UK
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