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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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Aguilar BA, Vieira S, Veiga AC, da Silva JVMB, Paixao TV, Rodrigues KP, Tank J, Ruys LA, de Souza HCD. Physical exercise is essential for increasing ventricular contractility in hypertensive rats treated with losartan. Hypertens Res 2024; 47:1350-1361. [PMID: 38418900 DOI: 10.1038/s41440-024-01611-z] [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: 08/09/2023] [Revised: 01/07/2024] [Accepted: 01/27/2024] [Indexed: 03/02/2024]
Abstract
The treatment of hypertensive patients with losartan is very common. Despite the reduction in blood pressure, its effects on cardiac contractility and sympathetic autonomic drive are still controversial. In turn, aerobic physical training (APT) also presents an important therapeutic option, providing significant improvements in cardiovascular autonomic control, however little is known about its effects on cardiac contractility, especially when associated with losartan. Therefore, we investigated in spontaneously hypertensive rats (SHR) the effects of losartan and APT on cardiac hemodynamics and functionality, with emphasis on autonomic tonic balance and cardiac contractility. Sixty-four SHR (18 weeks old) were divided into four groups (N = 16): vehicle; vehicle submitted to APT through swimming for 12 weeks; treated with losartan (5 mg·kg-1·d-1) for 12 weeks; and treated with losartan associated with APT. The groups were submitted to cardiac morphological and functional analysis by echocardiography; double blockade of cardiac autonomic receptors with atropine and propranolol; and coronary bed reactivity and left ventricular contractility analyses by the Langendorff technique. APT improved functional parameters and autonomic balance by reducing sympathetic drive and/or increasing vagal drive. In contrast, it promoted a concentric remodeling of the left ventricle (LV). Treatment with losartan reduced sympathetic autonomic drive and cardiac morphological parameters, but there were no significant gains in cardiac functionality and contractility. When combined, the concentric remodeling of the LV to APT was abolished and gains in cardiac functionality and contractility were observed. Our findings suggest that the effects of losartan and APT are complementary and should be applied together in the treatment of hypertension. In spontaneously hypertensive rats, the combination of aerobic physical training with losartan treatment was crucial to greater blood pressure reductions and an increase in left ventricular contractility. Furthermore, losartan treatment prevented the concentric left ventricular remodeling caused by aerobic physical training.
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Affiliation(s)
- Bruno Augusto Aguilar
- Department of Health Sciences, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Suenimeire Vieira
- Department of Health Sciences, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Ana Catarine Veiga
- Department of Health Sciences, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
| | | | - Tallys Velasco Paixao
- Department of Health Sciences, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Karine Pereira Rodrigues
- Department of Health Sciences, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Jens Tank
- Department of Cardiovascular Aerospace Medicine, Institute of Aerospace Medicine, German Aerospace Center, 51147, Cologne, Germany
| | - Leticia Araujo Ruys
- Department of Health Sciences, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Hugo Celso Dutra de Souza
- Department of Health Sciences, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, São Paulo, Brazil.
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Pauziene N, Ranceviene D, Rysevaite-Kyguoliene K, Ragauskas T, Inokaitis H, Sabeckis I, Plekhanova K, Khmel O, Pauza DH. Neurochemical alterations of intrinsic cardiac ganglionated nerve plexus caused by arterial hypertension developed during ageing in spontaneously hypertensive and Wistar Kyoto rats. J Anat 2023; 243:630-647. [PMID: 37083051 PMCID: PMC10485580 DOI: 10.1111/joa.13877] [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: 01/06/2023] [Revised: 03/28/2023] [Accepted: 03/30/2023] [Indexed: 04/22/2023] Open
Abstract
The acknowledged hypothesis of the cause of arterial hypertension is the emerging disbalance in sympathetic and parasympathetic regulations of the cardiovascular system. This disbalance manifests in a disorder of sustainability of endogenous autonomic and sensory neural substances including calcitonin gene-related peptide (CGRP). This study aimed to examine neurochemical alterations of intrinsic cardiac ganglionated nerve plexus (GP) triggered by arterial hypertension during ageing in spontaneously hypertensive rats of juvenile (prehypertensive, 8-9 weeks), adult (early hypertensive, 12-18 weeks) and elderly (persistent hypertensive, 46-60 weeks) age in comparison with the age-matched Wistar-Kyoto rats as controls. Parasympathetic, sympathetic and sensory neural structures of GP were analysed and evaluated morphometrically in tissue sections and whole-mount cardiac preparations. Both the elevated blood pressure and the evident ultrasonic signs of heart failure were identified for spontaneously hypertensive rats and in part for the aged control rats. The amount of adrenergic and immunoreactive to CGRP neural structures was increased in the adult group of spontaneously hypertensive rats along with the significant alterations that occurred during ageing. In conclusion, the revealed chemical alterations of GP support the hypothesis about the possible disbalance of efferent and afferent heart innervation and may be considered as the basis for the emergence and progression of arterial hypertension and perhaps even as a consequence of hypertension in the aged spontaneously hypertensive rats. The determined anatomical changes in the ageing Wistar-Kyoto rats suggest this breed being as inappropriate for its use as control animals for hypertension studies in older animal age.
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Affiliation(s)
- Neringa Pauziene
- Institute of Anatomy, Faculty of Medicine, Lithuanian University of Health Sciences, Kaunas, Lithuania
| | - Dalia Ranceviene
- Institute of Anatomy, Faculty of Medicine, Lithuanian University of Health Sciences, Kaunas, Lithuania
| | | | - Tomas Ragauskas
- Institute of Anatomy, Faculty of Medicine, Lithuanian University of Health Sciences, Kaunas, Lithuania
| | - Hermanas Inokaitis
- Institute of Anatomy, Faculty of Medicine, Lithuanian University of Health Sciences, Kaunas, Lithuania
| | - Ignas Sabeckis
- Institute of Anatomy, Faculty of Medicine, Lithuanian University of Health Sciences, Kaunas, Lithuania
| | - Khrystyna Plekhanova
- Institute of Anatomy, Faculty of Medicine, Lithuanian University of Health Sciences, Kaunas, Lithuania
| | - Olena Khmel
- Institute of Anatomy, Faculty of Medicine, Lithuanian University of Health Sciences, Kaunas, Lithuania
| | - Dainius H Pauza
- Institute of Anatomy, Faculty of Medicine, Lithuanian University of Health Sciences, Kaunas, Lithuania
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Nemtsova V, Burkard T, Vischer AS. Hypertensive Heart Disease: A Narrative Review Series-Part 2: Macrostructural and Functional Abnormalities. J Clin Med 2023; 12:5723. [PMID: 37685790 PMCID: PMC10488346 DOI: 10.3390/jcm12175723] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2023] [Revised: 08/22/2023] [Accepted: 08/29/2023] [Indexed: 09/10/2023] Open
Abstract
Hypertensive heart disease (HHD) remains a major global public health concern despite the implementation of new approaches for the management of hypertensive patients. The pathological changes occurring during HHD are complex and involve the development of structural and functional cardiac abnormalities. HHD describes a broad spectrum ranging from uncontrolled hypertension and asymptomatic left ventricular hypertrophy (LVH), either a concentric or an eccentric pattern, to the final development of clinical heart failure. Pressure-overload-induced LVH is recognised as the most important predictor of heart failure and sudden death and is associated with an increased risk of cardiac arrhythmias. Cardiac arrhythmias are considered to be one of the most important comorbidities affecting hypertensive patients. This is the second part of a three-part set of review articles. Here, we focus on the macrostructural and functional abnormalities associated with chronic high pressure, their involvement in HHD pathophysiology, and their role in the progression and prognosis of HHD.
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Affiliation(s)
- Valeriya Nemtsova
- Medical Outpatient Department and Hypertension Clinic, ESH Hypertension Centre of Excellence, University Hospital Basel, 4031 Basel, Switzerland
- Internal Diseases and Family Medicine Department, Educational and Scientific Medical Institute, National Technical University “Kharkiv Polytechnic Institute”, 61002 Kharkiv, Ukraine
| | - Thilo Burkard
- Medical Outpatient Department and Hypertension Clinic, ESH Hypertension Centre of Excellence, University Hospital Basel, 4031 Basel, Switzerland
- Department of Cardiology, University Hospital Basel, 4031 Basel, Switzerland
- Faculty of Medicine, University of Basel, 4056 Basel, Switzerland
| | - Annina S. Vischer
- Medical Outpatient Department and Hypertension Clinic, ESH Hypertension Centre of Excellence, University Hospital Basel, 4031 Basel, Switzerland
- Faculty of Medicine, University of Basel, 4056 Basel, Switzerland
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van Weperen VYH, Ripplinger CM, Vaseghi M. Autonomic control of ventricular function in health and disease: current state of the art. Clin Auton Res 2023; 33:491-517. [PMID: 37166736 PMCID: PMC10173946 DOI: 10.1007/s10286-023-00948-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2023] [Accepted: 04/20/2023] [Indexed: 05/12/2023]
Abstract
PURPOSE Cardiac autonomic dysfunction is one of the main pillars of cardiovascular pathophysiology. The purpose of this review is to provide an overview of the current state of the art on the pathological remodeling that occurs within the autonomic nervous system with cardiac injury and available neuromodulatory therapies for autonomic dysfunction in heart failure. METHODS Data from peer-reviewed publications on autonomic function in health and after cardiac injury are reviewed. The role of and evidence behind various neuromodulatory therapies both in preclinical investigation and in-use in clinical practice are summarized. RESULTS A harmonic interplay between the heart and the autonomic nervous system exists at multiple levels of the neuraxis. This interplay becomes disrupted in the setting of cardiovascular disease, resulting in pathological changes at multiple levels, from subcellular cardiac signaling of neurotransmitters to extra-cardiac, extra-thoracic remodeling. The subsequent detrimental cycle of sympathovagal imbalance, characterized by sympathoexcitation and parasympathetic withdrawal, predisposes to ventricular arrhythmias, progression of heart failure, and cardiac mortality. Knowledge on the etiology and pathophysiology of this condition has increased exponentially over the past few decades, resulting in a number of different neuromodulatory approaches. However, significant knowledge gaps in both sympathetic and parasympathetic interactions and causal factors that mediate progressive sympathoexcitation and parasympathetic dysfunction remain. CONCLUSIONS Although our understanding of autonomic imbalance in cardiovascular diseases has significantly increased, specific, pivotal mediators of this imbalance and the recognition and implementation of available autonomic parameters and neuromodulatory therapies are still lagging.
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Affiliation(s)
- Valerie Y H van Weperen
- Division of Cardiology, Department of Medicine, UCLA Cardiac Arrythmia Center, University of California, 100 Medical Plaza, Suite 660, Los Angeles, CA, 90095, USA
| | | | - Marmar Vaseghi
- Division of Cardiology, Department of Medicine, UCLA Cardiac Arrythmia Center, University of California, 100 Medical Plaza, Suite 660, Los Angeles, CA, 90095, USA.
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Wu HF, Huang CW, Art J, Liu HX, Hart GW, Zeltner N. O-GlcNAcylation is crucial for sympathetic neuron development, maintenance, functionality and contributes to peripheral neuropathy. Front Neurosci 2023; 17:1137847. [PMID: 37229433 PMCID: PMC10203903 DOI: 10.3389/fnins.2023.1137847] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2023] [Accepted: 04/12/2023] [Indexed: 05/27/2023] Open
Abstract
O-GlcNAcylation is a post-translational modification (PTM) that regulates a wide range of cellular functions and has been associated with multiple metabolic diseases in various organs. The sympathetic nervous system (SNS) is the efferent portion of the autonomic nervous system that regulates metabolism of almost all organs in the body. How much the development and functionality of the SNS are influenced by O-GlcNAcylation, as well as how such regulation could contribute to sympathetic neuron (symN)-related neuropathy in diseased states, remains unknown. Here, we assessed the level of protein O-GlcNAcylation at various stages of symN development, using a human pluripotent stem cell (hPSC)-based symN differentiation paradigm. We found that pharmacological disruption of O-GlcNAcylation impaired both the growth and survival of hPSC-derived symNs. In the high glucose condition that mimics hyperglycemia, hPSC-derived symNs were hyperactive, and their regenerative capacity was impaired, which resembled typical neuronal defects in patients and animal models of diabetes mellitus. Using this model of sympathetic neuropathy, we discovered that O-GlcNAcylation increased in symNs under high glucose, which lead to hyperactivity. Pharmacological inhibition of O-GlcNAcylation rescued high glucose-induced symN hyperactivity and cell stress. This framework provides the first insight into the roles of O-GlcNAcylation in both healthy and diseased human symNs and may be used as a platform for therapeutic studies.
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Affiliation(s)
- Hsueh-Fu Wu
- Center for Molecular Medicine, University of Georgia, Athens, GA, United States
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA, United States
| | - Chia-Wei Huang
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA, United States
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA, United States
| | - Jennifer Art
- Center for Molecular Medicine, University of Georgia, Athens, GA, United States
- Biomedical and Translational Sciences Institute, Neuroscience Program, University of Georgia, Athens, GA, United States
| | - Hong-Xiang Liu
- Regenerative Bioscience Center, Department of Animal and Dairy Science, College of Agricultural and Environmental Sciences, University of Georgia, Athens, GA, United States
| | - Gerald W. Hart
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA, United States
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA, United States
| | - Nadja Zeltner
- Center for Molecular Medicine, University of Georgia, Athens, GA, United States
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA, United States
- Department of Cellular Biology, University of Georgia, Athens, GA, United States
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Spontaneously hypertensive rats manifest deficits in emotional response to 22-kHz and 50-kHz ultrasonic playback. Prog Neuropsychopharmacol Biol Psychiatry 2023; 120:110615. [PMID: 36007820 DOI: 10.1016/j.pnpbp.2022.110615] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Revised: 08/03/2022] [Accepted: 08/13/2022] [Indexed: 10/15/2022]
Abstract
Many symptoms used routinely for human psychiatric diagnosis cannot be directly observed in animals which cannot describe their internal states. However, the ultrasonic vocalizations (USV) rodents use to communicate their emotional states can be measured. USV have therefore become a particularly useful tool in brain disease models. Spontaneously hypertensive rats (SHR) are considered an animal model of attention deficit hyperactivity disorder (ADHD) and schizophrenia. However, the specifics of SHR's behavior have not been fully described and there is very little data on their USV. Recently, we developed a communication model, in which Wistar rats are exposed to pre-recorded playbacks of aversive (22-kHz) or appetitive (50-kHz) USV, and their vocal responses depend on the extent of prior fear conditioning (0, 1, 6 or 10 shocks). Here, we investigated SHR's behavior and heart rate (HR) in our communication model, in comparison to Wistar rats employed as controls. In general, SHR emitted typical USV categories, however, they contained more short 22-kHz and less 50-kHz USV overall. Moreover, fewer SHR, in comparison with Wistar rats, emitted long 22-kHz USV after fear conditioning. SHR did not show a 50-kHz playback-induced HR increase, while they showed a profound 22-kHz playback-induced HR decrease. Finally, the number of previously delivered conditioning shocks appeared to have no effect on the investigated vocal, locomotor and HR responses of SHR. The phenomena observed in SHR are potentially attributable to deficits in emotional perception and processing. A lower number of 50-kHz USV emitted by SHR may reflect observations of speech impairments in human patients and further supports the usefulness of SHR to model ADHD and schizophrenia.
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Ranceviene D, Rysevaite-Kyguoliene K, Inokaitis H, Saburkina I, Plekhanova K, Sabeckiene D, Sabeckis I, Azukaite J, Pauza DH, Pauziene N. Early structural alterations of intrinsic cardiac ganglionated plexus in spontaneously hypertensive rats. Histol Histopathol 2022; 37:955-970. [PMID: 35356999 DOI: 10.14670/hh-18-453] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Persistent arterial hypertension leads to structural and functional remodeling of the heart resulting in myocardial ischemia, fibrosis, hypertrophy, and eventually heart failure. Previous studies have shown that individual neurons composing the intracardiac ganglia are hypertrophied in the failing human, dog, and rat hearts, indicating that this process involves changes in cardiac innervation. However, despite a wealth of data on changes in intrinsic cardiac ganglionated plexus (GP) in late-stage disease models, little is known about the effects of hypertension on cardiac innervation during the early onset of heart failure development. Thus, we examined the impact of early hypertension on the structural organization of the intrinsic cardiac ganglionated plexus in juvenile (8-9 weeks) and adult (12-18 weeks) spontaneously hypertensive (SH) and age-matched Wistar-Kyoto (WKY) rats. GP was studied using a combination of immunofluorescence confocal microscopy and transmission electron microscopy in whole-mount preparations and tissue sections. Here, we report intrinsic cardiac GP of SH rats to display multiple structural alterations: (i) a decrease in the intracardiac neuronal number, (ii) a marked reduction in axonal diameters and their proportion within intracardiac nerves, (iii) an increased density of myocardial nerve fibers, and (iv) neuropathic abnormalities in cardiac glial cells. These findings represent early neurological changes of the intrinsic ganglionated plexus of the heart introduced by early-onset arterial hypertension in young adult SH rats.
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Affiliation(s)
- Dalia Ranceviene
- Institute of Anatomy, Lithuanian University of Health Sciences, Kaunas, Lithuania
| | | | - Hermanas Inokaitis
- Institute of Anatomy, Lithuanian University of Health Sciences, Kaunas, Lithuania
| | - Inga Saburkina
- Institute of Anatomy, Lithuanian University of Health Sciences, Kaunas, Lithuania
| | - Khrystyna Plekhanova
- Institute of Anatomy, Lithuanian University of Health Sciences, Kaunas, Lithuania
| | - Deimante Sabeckiene
- Institute of Anatomy, Lithuanian University of Health Sciences, Kaunas, Lithuania
| | - Ignas Sabeckis
- Institute of Anatomy, Lithuanian University of Health Sciences, Kaunas, Lithuania
| | - Joana Azukaite
- Institute of Anatomy, Lithuanian University of Health Sciences, Kaunas, Lithuania
| | - Dainius H Pauza
- Institute of Anatomy, Lithuanian University of Health Sciences, Kaunas, Lithuania
| | - Neringa Pauziene
- Institute of Anatomy, Lithuanian University of Health Sciences, Kaunas, Lithuania.
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Haburčák M, Harrison J, Buyukozturk MM, Sona S, Bates S, Birren SJ. Heightened sympathetic neuron activity and altered cardiomyocyte properties in spontaneously hypertensive rats during the postnatal period. Front Synaptic Neurosci 2022; 14:995474. [PMID: 36247695 PMCID: PMC9561918 DOI: 10.3389/fnsyn.2022.995474] [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: 07/15/2022] [Accepted: 09/12/2022] [Indexed: 11/18/2022] Open
Abstract
The Spontaneously Hypertensive Rat (SHR) has increased sympathetic drive to the periphery that precedes and contributes to the development of high blood pressure, making it a useful model for the study of neurogenic hypertension. Comparisons to the normotensive Wistar Kyoto (WKY) rat have demonstrated altered active and intrinsic properties of SHR sympathetic neurons shortly before the onset of hypertension. Here we examine the structural and functional plasticity of postnatal SHR and WKY sympathetic neurons cultured alone or co-cultured with cardiomyocytes under conditions of limited extrinsic signaling. SHR neurons have an increased number of structural synaptic sites compared to age-matched WKY neurons, measured by the co-localization of presynaptic vesicular acetylcholine transporter and postsynaptic shank proteins. Whole cell recordings show that SHR neurons have a higher synaptic charge than WKY neurons, demonstrating that the increase in synaptic sites is associated with increased synaptic transmission. Differences in synaptic properties are not associated with altered firing rates between postnatal WKY and SHR neurons and are not influenced by interactions with target cardiomyocytes from either strain. Both SHR and WKY neurons show tonic firing patterns in our cultures, which are depleted of non-neuronal ganglionic cells and provide limited neurotrophic signaling. This suggests that the normal mature, phasic firing of sympathetic neurons requires extrinsic signaling, with potentially differential responses in the prehypertensive SHR, which have been reported to maintain tonic firing at later developmental stages. While cardiomyocytes do not drive neuronal differences in our cultures, SHR cardiomyocytes display decreased hypertrophy compared to WKY cells and altered responses to co-cultured sympathetic neurons. These experiments suggest that altered signaling in SHR neurons and cardiomyocytes contributes to changes in the cardiac-sympathetic circuit in prehypertensive rats as early as the postnatal period.
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Affiliation(s)
- Marián Haburčák
- Biology Department, Brandeis University, Waltham, MA, United States,Volen Center for Complex Systems, Brandeis University, Waltham, MA, United States
| | - Joshua Harrison
- Biology Department, Brandeis University, Waltham, MA, United States,Volen Center for Complex Systems, Brandeis University, Waltham, MA, United States
| | - Melda M. Buyukozturk
- Biology Department, Brandeis University, Waltham, MA, United States,Volen Center for Complex Systems, Brandeis University, Waltham, MA, United States
| | - Surbhi Sona
- Biology Department, Brandeis University, Waltham, MA, United States,Volen Center for Complex Systems, Brandeis University, Waltham, MA, United States
| | - Samuel Bates
- Biology Department, Brandeis University, Waltham, MA, United States,Volen Center for Complex Systems, Brandeis University, Waltham, MA, United States
| | - Susan J. Birren
- Biology Department, Brandeis University, Waltham, MA, United States,Volen Center for Complex Systems, Brandeis University, Waltham, MA, United States,*Correspondence: Susan J. Birren
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Kim HK, Ishizawa R, Fukazawa A, Wang Z, Bezan Petric U, Hu MC, Smith SA, Mizuno M, Vongpatanasin W. Dapagliflozin Attenuates Sympathetic and Pressor Responses to Stress in Young Prehypertensive Spontaneously Hypertensive Rats. Hypertension 2022; 79:1824-1834. [PMID: 35652337 PMCID: PMC9308730 DOI: 10.1161/hypertensionaha.122.19177] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
BACKGROUND SGLT2i (sodium-glucose cotransporter 2 inhibitor), a class of anti-diabetic medications, is shown to reduce blood pressure (BP) in hypertensive patients with type 2 diabetes. Mechanisms underlying this action are unknown but SGLT2i-induced sympathoinhibition is thought to play a role. Whether SGLT2i reduces BP and sympathetic nerve activity (SNA) in a nondiabetic prehypertension model is unknown. METHODS Accordingly, we assessed changes in conscious BP using radiotelemetry and alterations in mean arterial pressure and renal SNA during simulated exercise in nondiabetic spontaneously hypertensive rats during chronic administration of a diet containing dapagliflozin (0.5 mg/kg per day) versus a control diet. RESULTS We found that dapagliflozin had no effect on fasting blood glucose, insulin, or hemoglobin A1C levels. However, dapagliflozin reduced BP in young (8-week old) spontaneously hypertensive rats as well as attenuated the age-related rise in BP in adult spontaneously hypertensive rat up to 17-weeks of age. The rises in mean arterial pressure and renal SNA during simulated exercise (exercise pressor reflex activation by hindlimb muscle contraction) were significantly reduced after 4 weeks of dapagliflozin (Δmean arterial pressure: 10±7 versus 25±14 mm Hg, Δrenal SNA: 31±17% versus 68±39%, P<0.05). Similarly, rises in mean arterial pressure and renal SNA during mechanoreflex stimulation by passive hindlimb stretching were also attenuated by dapagliflozin. Heart weight was significantly decreased in dapagliflozin compared with the control group. CONCLUSIONS These data demonstrate a novel role for SGLT2i in reducing resting BP as well as the activity of skeletal muscle reflexes, independent of glycemic control. Our study may have important clinical implications for preventing hypertension and hypertensive heart disease in young prehypertensive individuals.
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Affiliation(s)
- Han-Kyul Kim
- Departments of Internal Medicine-Hypertension Section (H.-K.K., Z.W., U.B.P., W.V.), University of Texas Southwestern Medical Center, Dallas, TX.,Applied Clinical Research (H.-K.K., R.I., A.F., S.A.S., M.M.), University of Texas Southwestern Medical Center, Dallas, TX
| | - Rie Ishizawa
- Applied Clinical Research (H.-K.K., R.I., A.F., S.A.S., M.M.), University of Texas Southwestern Medical Center, Dallas, TX
| | - Ayumi Fukazawa
- Applied Clinical Research (H.-K.K., R.I., A.F., S.A.S., M.M.), University of Texas Southwestern Medical Center, Dallas, TX
| | - Zhongyun Wang
- Departments of Internal Medicine-Hypertension Section (H.-K.K., Z.W., U.B.P., W.V.), University of Texas Southwestern Medical Center, Dallas, TX
| | - Ursa Bezan Petric
- Departments of Internal Medicine-Hypertension Section (H.-K.K., Z.W., U.B.P., W.V.), University of Texas Southwestern Medical Center, Dallas, TX
| | - Ming Chang Hu
- Internal Medicine-Renal Division (M.C.H.), University of Texas Southwestern Medical Center, Dallas, TX.,Pak Center of Mineral Metabolism and Clinical Research (M.C.H., W.V.), University of Texas Southwestern Medical Center, Dallas, TX
| | - Scott A Smith
- Applied Clinical Research (H.-K.K., R.I., A.F., S.A.S., M.M.), University of Texas Southwestern Medical Center, Dallas, TX
| | - Masaki Mizuno
- Applied Clinical Research (H.-K.K., R.I., A.F., S.A.S., M.M.), University of Texas Southwestern Medical Center, Dallas, TX
| | - Wanpen Vongpatanasin
- Departments of Internal Medicine-Hypertension Section (H.-K.K., Z.W., U.B.P., W.V.), University of Texas Southwestern Medical Center, Dallas, TX.,Pak Center of Mineral Metabolism and Clinical Research (M.C.H., W.V.), University of Texas Southwestern Medical Center, Dallas, TX
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11
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Gonzalez-Gonzalez MA, Romero K, Beitter J, Lloyd D, Lam DV, Hernandez-Reynoso AG, Kanneganti A, Kim HK, Bjune CK, Smith S, Vongpatanasin W, Romero-Ortega MI. Renal Nerve Activity and Arterial Depressor Responses Induced by Neuromodulation of the Deep Peroneal Nerve in Spontaneously Hypertensive Rats. Front Neurosci 2022; 16:726467. [PMID: 35651628 PMCID: PMC9149221 DOI: 10.3389/fnins.2022.726467] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Accepted: 03/21/2022] [Indexed: 11/13/2022] Open
Abstract
Hypertension is a main cause of death in the United States with more than 103 million adults affected. While pharmacological treatments are effective, blood pressure (BP) remains uncontrolled in 50–60% of resistant hypertensive subjects. Using a custom-wired miniature electrode, we previously reported that deep peroneal nerve stimulation (DPNS) elicited acute cardiovascular depressor responses in anesthetized spontaneously hypertensive rats (SHRs). Here, we further study this effect by implementing a wireless system and exploring different stimulation parameters to achieve a maximum depressor response. Our results indicate that DPNS consistently induces a reduction in BP and suggests that renal sympathetic nerve activity (RSNA) is altered by this bioelectronic treatment. To test the acute effect of DPNS in awake animals, we developed a novel miniaturized wireless microchannel electrode (w-μCE), with a Z-shaped microchannel through which the target nerves slide and lock into the recording/stimulation chamber. Animals implanted with w-μCE and BP telemetry systems for 3 weeks showed an average BP of 150 ± 14 mmHg, which was reduced significantly by an active DPNS session to 135 ± 8 mmHg (p < 0.04), but not in sham-treated animals. The depressor response in animals with an active w-μCE was progressively returned to baseline levels 14 min later (164 ± 26 mmHg). This depressor response was confirmed in restrained fully awake animals that received DPNS for 10 days, where tail-cuff BP measurements showed that systolic BP in SHR lowered 10% at 1 h and 16% 2 h after the DPNS when compared to the post-implantation baseline. Together, these results support the use of DPN neuromodulation as a possible strategy to lower BP in drug-resistant hypertension.
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Affiliation(s)
| | - Kevin Romero
- Department of Biomedical Engineering and Biomedical Sciences, University of Houston, Houston, TX, United States
| | - John Beitter
- Department of Biomedical Engineering, The University of Texas at Dallas, Dallas, TX, United States
| | - David Lloyd
- Department of Biomedical Engineering and Biomedical Sciences, University of Houston, Houston, TX, United States
| | - Danny V. Lam
- Department of Biomedical Engineering, The University of Texas at Dallas, Dallas, TX, United States
| | | | - Aswini Kanneganti
- Department of Biomedical Engineering, The University of Texas at Dallas, Dallas, TX, United States
| | - Han-Kyul Kim
- Hypertension Section, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, United States
| | | | - Scott Smith
- Hypertension Section, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, United States
- Applied Clinical Research, University of Texas Southwestern Medical Center, Dallas, TX, United States
| | - Wanpen Vongpatanasin
- Hypertension Section, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, United States
| | - Mario I. Romero-Ortega
- Department of Biomedical Engineering and Biomedical Sciences, University of Houston, Houston, TX, United States
- *Correspondence: Mario I. Romero-Ortega,
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12
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Neely OC, Domingos AI, Paterson DJ. Macrophages Can Drive Sympathetic Excitability in the Early Stages of Hypertension. Front Cardiovasc Med 2022; 8:807904. [PMID: 35155614 PMCID: PMC8828732 DOI: 10.3389/fcvm.2021.807904] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Accepted: 12/21/2021] [Indexed: 12/31/2022] Open
Abstract
Hypertension is a major health burden worldwide with many cases resistant to current treatments. Hyperactivity of the sympathetic nervous contributes to the etiology and progression of the disease, where emerging evidence suggests that inflammation may underpin the development of sympathetic dysautonomia. This study examined whether macrophages could drive the sympathetic phenotype in Spontaneously Hypertensive Rats (SHR) before animals develop high pressure. Stellate neurons from wild-type control Wistar rats and SHRs were co-cultured with blood leukocytes from their own strain, and also crossed cultured between strains. The calcium transient response to nicotinic stimulation was recorded using Fura-2 calcium imaging, where SHR neurons had a greater calcium transient compared with Wistar neurons. However, when co-cultured with leukocytes, Wistar neurons began to phenocopy the SHR sympathetic hyperactivity, while the SHR neurons themselves were unaltered. Resident leukocyte populations of the SHR and Wistar stellate ganglia were then compared using flow cytometry, where there was a shift in monocyte-macrophage subset proportions. While classical monocyte-macrophages were predominant in the Wistar, there were relatively more of the non-classical subset in the SHR, which have been implicated in pro-inflammatory roles in a number of diseases. When bone marrow-derived macrophages (BMDMs) were co-cultured with stellate neurons, they made Wistar neurons recapitulate the SHR nicotinic stimulated calcium transient. Wistar BMDMs however, had no effect on SHR neurons, even though SHR BMDMs increased SHR neuron responsiveness further above their hyper-responsive state. Taken together, these findings show that macrophages can be potent enhancers of sympathetic neuronal calcium responsiveness, and thus could conceivably play a role in peripheral sympathetic hyperactivity observed in the early stages of hypertension.
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Affiliation(s)
- Oliver C Neely
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
| | - Ana I Domingos
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
| | - David J Paterson
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
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13
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Mowry FE, Peaden SC, Stern JE, Biancardi VC. TLR4 and AT1R mediate blood-brain barrier disruption, neuroinflammation, and autonomic dysfunction in spontaneously hypertensive rats. Pharmacol Res 2021; 174:105877. [PMID: 34610452 PMCID: PMC8648989 DOI: 10.1016/j.phrs.2021.105877] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Revised: 09/03/2021] [Accepted: 09/05/2021] [Indexed: 01/23/2023]
Abstract
Angiotensin II (AngII) is implicated in neuroinflammation, blood-brain barrier (BBB) disruption, and autonomic dysfunction in hypertension. We have previously shown that exogenous AngII stimulates Toll-like receptor 4 (TLR4) via AngII type 1 receptor (AT1R), inducing activation of hypothalamic microglia ex vivo, and that AngII-AT1R signaling is necessary for the loss of BBB integrity in spontaneously hypertensive rats (SHRs). Herein, we hypothesized that microglial TLR4 and AT1R signaling interactions represent a crucial mechanistic link between AngII-mediated neuroinflammation and BBB disruption, thereby contributing to sympathoexcitation in SHRs. Male SHRs were treated with TAK-242 (TLR4 inhibitor; 2 weeks), Losartan (AT1R inhibitor; 4 weeks), or vehicle, and age-matched to control Wistar Kyoto rats (WKYs). TLR4 and AT1R inhibitions normalized increased TLR4, interleukin-6, and tumor necrosis factor-α protein densities in SHR cardioregulatory nuclei (hypothalamic paraventricular nucleus [PVN], rostral ventrolateral medulla [RVLM], and nucleus tractus solitarius [NTS]), and abolished enhanced microglial activation. PVN, RVLM, and NTS BBB permeability analyses revealed complete restoration after TAK-242 treatment, whereas SHRs presented with elevated dye leakage. Mean arterial pressure was normalized in Losartan-treated SHRs, and attenuated with TLR4 inhibition. In conscious assessments, TLR4 blockade rescued SHR baroreflex sensitivity to vasoactive drugs, and reduced the SHR pressor response to ganglionic blockade to normal levels. These data suggest that TLR4 activation plays a substantial role in mediating a feed-forward pro-hypertensive cycle involving BBB disruption, neuroinflammation, and autonomic dysfunction, and that TLR4-specific therapeutic interventions may represent viable alternatives in the treatment of hypertension.
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Affiliation(s)
- Francesca E Mowry
- Department of Anatomy, Physiology & Pharmacology, College of Veterinary Medicine, Auburn University, Auburn, AL, USA; Center for Neurosciences Initiative, Auburn University, Auburn, AL, USA
| | - Sarah C Peaden
- Department of Anatomy, Physiology & Pharmacology, College of Veterinary Medicine, Auburn University, Auburn, AL, USA
| | - Javier E Stern
- Center for Neuroinflammation, Georgia State University, Atlanta, GA, USA
| | - Vinicia C Biancardi
- Department of Anatomy, Physiology & Pharmacology, College of Veterinary Medicine, Auburn University, Auburn, AL, USA; Center for Neurosciences Initiative, Auburn University, Auburn, AL, USA.
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14
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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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15
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Development of the hypersecretory phenotype in the population of adrenal chromaffin cells from prehypertensive SHRs. Pflugers Arch 2021; 473:1775-1793. [PMID: 34510285 DOI: 10.1007/s00424-021-02614-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Revised: 08/10/2021] [Accepted: 08/11/2021] [Indexed: 10/20/2022]
Abstract
The hypersecretory phenotype of adrenal chromaffin cells (CCs) from early spontaneously hypertensive rats (SHRs) mainly results from enhanced Ca2+-induced Ca2+-release (CICR). A key question is if these abnormalities can be traced to the prehypertensive stage. Spontaneous and stimulus-induced catecholamine exocytosis, intracellular Ca2+ signals, and dense-core granule size and density were examined in CCs from prehypertensive and hypertensive SHRs and compared with age-matched Wistar-Kyoto rats (WKY). During the prehypertensive stage, the depolarization-elicited catecholamine exocytosis was ~ 2.9-fold greater in SHR than in WKY CCs. Interestingly, in half of CCs the exocytosis was indistinguishable from WKY CCs, while it was between 3- and sixfold larger in the other half. Likewise, caffeine-induced exocytosis was ~ twofold larger in prehypertensive SHR. Accordingly, depolarization and caffeine application elicited [Ca2+]i rises ~ 1.5-fold larger in prehypertensive SHR than in WKY CCs. Ryanodine reduced the depolarization-induced secretion in prehypertensive SHR by 57%, compared to 14% in WKY CCs, suggesting a greater contribution of intracellular Ca2+ release to exocytosis. In SHR CCs, the mean spike amplitude and charge per spike were significantly larger than in WKY CCs, regardless of age and stimulus type. This difference in granule content could explain in part the enhanced exocytosis in SHR CCs. However, electron microscopy did not reveal significant differences in granule size between SHRs and WKY rats' adrenal medulla. Nonetheless, preSHR and hypSHR display 63% and 82% more granules than WKY, which could explain in part the enhanced catecholamine secretion. The mechanism responsible for the heterogeneous population of prehypertensive SHR CCs and the bias towards secreting more medium and large granules remains unexplained.
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16
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Gardim CB, Veiga AC, Aguilar BA, Philbois SV, Souza HCD. Effects of chronic cholinergic stimulation associated with aerobic physical training on cardiac morphofunctional and autonomic parameters in spontaneously hypertensive rats. Sci Rep 2021; 11:17141. [PMID: 34433865 PMCID: PMC8387354 DOI: 10.1038/s41598-021-96505-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Accepted: 08/04/2021] [Indexed: 02/04/2023] Open
Abstract
We investigated hemodynamic, cardiac morphofunctional, and cardiovascular autonomic adaptations in spontaneously hypertensive rats (SHRs) after aerobic physical training associated with chronic cholinergic stimulation. Fifty-four SHRs were divided into two groups: trained and untrained. Each group was further subdivided into three smaller groups: vehicle, treated with pyridostigmine bromide at 5 mg/kg/day, and treated with pyridostigmine bromide at 15 mg/kg/day. The following protocols were assessed: echocardiography, autonomic double pharmacological blockade, heart rate variability (HRV), blood pressure variability (BPV), and baroreflex sensitivity (BRS). Physical training and pyridostigmine bromide reduced BP and HR and increased vagal participation in cardiac autonomic tonic balance. The associated responses were then potentialized. Treatment with pyridostigmine bromide increased HRV oscillation of both low frequency (LF: 0.2-0.75 Hz) and high frequency (HF: 0.75-3 Hz). However, the association with physical training attenuated HF oscillations. Additionally, treatment with pyridostigmine bromide also increased LF oscillations of BPV. Both treatment groups promoted morphofunctional adaptations, and associated increased ejection volume, ejection fraction, cardiac output, and cardiac index. In conclusion, the association of pyridostigmine bromide and physical training promoted greater benefits in hemodynamic parameters and increased vagal influence on cardiac autonomic tonic balance. Nonetheless, treatment with pyridostigmine bromide alone seems to negatively affect BPV and the association of treatment negatively influences HRV.
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Affiliation(s)
- Camila B Gardim
- Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Ana Catarine Veiga
- Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Bruno A Aguilar
- Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Stella V Philbois
- Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Hugo C D Souza
- Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, SP, Brazil.
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17
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Cao LL, Marshall JM, Fabritz L, Brain KL. Resting cardiac sympathetic firing frequencies suppress terminal norepinephrine transporter uptake. Auton Neurosci 2021; 232:102794. [PMID: 33714751 DOI: 10.1016/j.autneu.2021.102794] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Revised: 02/23/2021] [Accepted: 02/25/2021] [Indexed: 10/22/2022]
Abstract
The prejunctional norepinephrine transporter (NET) is responsible for the clearance of released norepinephrine (NE) back into the sympathetic nerve terminal. NET regulation must be tightly controlled as variations could have important implications for neurotransmission. Thus far, the effects of sympathetic neuronal activity on NET function have been unclear. Here, we optically monitor single-terminal cardiac NET activity ex vivo in response to a broad range of sympathetic postganglionic action potential (AP) firing frequencies. Isolated murine left atrial appendages were loaded with a fluorescent NET substrate [Neurotransmitter Transporter Uptake Assay (NTUA)] and imaged with confocal microscopy. Sympathetic APs were induced with electrical field stimulation at 0.2-10 Hz (0.1-0.2 ms pulse width). Exogenous NE was applied during the NTUA uptake- and washout phases to investigate substrate competition and displacement, respectively, on transport. Single-terminal NET reuptake rate was rapidly suppressed in a frequency-dependent manner with an inhibitory EF50 of 0.9 Hz. At 2 Hz, the effect was reversed by the α2-adrenoceptor antagonist yohimbine (1 μM) (p < 0.01) with no further effect imposed by the muscarinic receptor antagonist atropine (1 μM). Additionally, high exogenous NE concentrations abolished NET reuptake (1 μM NE; p < 0.0001) and displaced terminal specific NTUA during washout (1-100 μM NE; p < 0.0001). We have also identified α2-adrenoceptor-induced suppression of NET reuptake rate during resting stimulation frequencies, which could oppose the effect of autoinhibition-mediated suppression of exocytosis and thus amplify the effects of sympathetic drive on cardiac function.
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Affiliation(s)
- Lily L Cao
- School of Biomedical Science, Institute of Clinical Science, College of Medical and Dental Sciences, University of Birmingham, B15 2TT, UK.
| | - Janice M Marshall
- School of Biomedical Science, Institute of Clinical Science, College of Medical and Dental Sciences, University of Birmingham, B15 2TT, UK.
| | - Larissa Fabritz
- Institute of Cardiovascular Science, College of Medical and Dental Sciences, University of Birmingham, B15 2TT, UK; Department of Cardiology, University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK.
| | - Keith L Brain
- School of Biomedical Science, Institute of Clinical Science, College of Medical and Dental Sciences, University of Birmingham, B15 2TT, UK.
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18
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Phthalamide derivatives as ACE/AChE/BuChE inhibitors against cardiac hypertrophy: an in silico, in vitro, and in vivo modeling approach. Med Chem Res 2021. [DOI: 10.1007/s00044-021-02707-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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19
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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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20
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Herring N, Tapoulal N, Kalla M, Ye X, Borysova L, Lee R, Dall'Armellina E, Stanley C, Ascione R, Lu CJ, Banning AP, Choudhury RP, Neubauer S, Dora K, Kharbanda RK, Channon KM. Neuropeptide-Y causes coronary microvascular constriction and is associated with reduced ejection fraction following ST-elevation myocardial infarction. Eur Heart J 2020; 40:1920-1929. [PMID: 30859228 PMCID: PMC6588241 DOI: 10.1093/eurheartj/ehz115] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/02/2018] [Revised: 10/23/2018] [Accepted: 02/18/2019] [Indexed: 12/11/2022] Open
Abstract
Aims The co-transmitter neuropeptide-Y (NPY) is released during high sympathetic drive, including ST-elevation myocardial infarction (STEMI), and can be a potent vasoconstrictor. We hypothesized that myocardial NPY levels correlate with reperfusion and subsequent recovery following primary percutaneous coronary intervention (PPCI), and sought to determine if and how NPY constricts the coronary microvasculature. Methods and results Peripheral venous NPY levels were significantly higher in patients with STEMI (n = 45) compared to acute coronary syndromes/stable angina ( n = 48) or with normal coronary arteries (NC, n = 16). Overall coronary sinus (CS) and peripheral venous NPY levels were significantly positively correlated (r = 0.79). STEMI patients with the highest CS NPY levels had significantly lower coronary flow reserve, and higher index of microvascular resistance measured with a coronary flow wire. After 2 days they also had significantly higher levels of myocardial oedema and microvascular obstruction on cardiac magnetic resonance imaging, and significantly lower ejection fractions and ventricular dilatation 6 months later. NPY (100–250 nM) caused significant vasoconstriction of rat microvascular coronary arteries via increasing vascular smooth muscle calcium waves, and also significantly increased coronary vascular resistance and infarct size in Langendorff hearts. These effects were blocked by the Y1 receptor antagonist BIBO3304 (1 μM). Immunohistochemistry of the human coronary microvasculature demonstrated the presence of vascular smooth muscle Y1 receptors. Conclusion High CS NPY levels immediately after reperfusion correlate with microvascular dysfunction, greater myocardial injury, and reduced ejection fraction 6 months after STEMI. NPY constricts the coronary microcirculation via the Y1 receptor, and antagonists may be a useful PPCI adjunct therapy. ![]()
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Affiliation(s)
- Neil Herring
- Department of Physiology, Anatomy and Genetics, Burdon Sandersn Cardiac Science Centre, University of Oxford, Parks Road, Oxford OX13PT, UK.,Department of Cardiovascular Medicine, British Heart Foundation Centre of Research Excellence, University of Oxford, John Radcliffe Hospital, Headley Way, Oxford, UK
| | - Nidi Tapoulal
- Department of Physiology, Anatomy and Genetics, Burdon Sandersn Cardiac Science Centre, University of Oxford, Parks Road, Oxford OX13PT, UK
| | - Manish Kalla
- Department of Physiology, Anatomy and Genetics, Burdon Sandersn Cardiac Science Centre, University of Oxford, Parks Road, Oxford OX13PT, UK.,Department of Cardiovascular Medicine, British Heart Foundation Centre of Research Excellence, University of Oxford, John Radcliffe Hospital, Headley Way, Oxford, UK
| | - Xi Ye
- Department of Pharmacology, University of Oxford, Mansfield Road, Oxford UK
| | - Lyudmyla Borysova
- Department of Pharmacology, University of Oxford, Mansfield Road, Oxford UK
| | - Regent Lee
- Department of Cardiovascular Medicine, British Heart Foundation Centre of Research Excellence, University of Oxford, John Radcliffe Hospital, Headley Way, Oxford, UK
| | - Erica Dall'Armellina
- Department of Cardiovascular Medicine, British Heart Foundation Centre of Research Excellence, University of Oxford, John Radcliffe Hospital, Headley Way, Oxford, UK.,Oxford Acute Vascular Imaging Centre, Department of Cardiovascular Medicine, University of Oxford, John Radcliffe Hospital, Headley Way, Oxford UK
| | | | - Raimondo Ascione
- Bristol Heart Institute, Bristol Royal Infirmary, and Faculty of Health Sciences, University of Bristol, Horfield Road, Bristol UK
| | - Chieh-Ju Lu
- Department of Physiology, Anatomy and Genetics, Burdon Sandersn Cardiac Science Centre, University of Oxford, Parks Road, Oxford OX13PT, UK
| | - Adrian P Banning
- Department of Cardiovascular Medicine, British Heart Foundation Centre of Research Excellence, University of Oxford, John Radcliffe Hospital, Headley Way, Oxford, UK.,National Institute for Health Research (NIHR) Biomedical Research Centre, Oxford University Hospitals NHS Foundation Trust, John Radcliffe Hospital, Headley Way Oxford, UK
| | - Robin P Choudhury
- Department of Cardiovascular Medicine, British Heart Foundation Centre of Research Excellence, University of Oxford, John Radcliffe Hospital, Headley Way, Oxford, UK.,Oxford Acute Vascular Imaging Centre, Department of Cardiovascular Medicine, University of Oxford, John Radcliffe Hospital, Headley Way, Oxford UK
| | - Stefan Neubauer
- Department of Cardiovascular Medicine, British Heart Foundation Centre of Research Excellence, University of Oxford, John Radcliffe Hospital, Headley Way, Oxford, UK.,National Institute for Health Research (NIHR) Biomedical Research Centre, Oxford University Hospitals NHS Foundation Trust, John Radcliffe Hospital, Headley Way Oxford, UK
| | - Kim Dora
- Department of Pharmacology, University of Oxford, Mansfield Road, Oxford UK
| | - Rajesh K Kharbanda
- Department of Cardiovascular Medicine, British Heart Foundation Centre of Research Excellence, University of Oxford, John Radcliffe Hospital, Headley Way, Oxford, UK.,National Institute for Health Research (NIHR) Biomedical Research Centre, Oxford University Hospitals NHS Foundation Trust, John Radcliffe Hospital, Headley Way Oxford, UK
| | - Keith M Channon
- Department of Cardiovascular Medicine, British Heart Foundation Centre of Research Excellence, University of Oxford, John Radcliffe Hospital, Headley Way, Oxford, UK.,National Institute for Health Research (NIHR) Biomedical Research Centre, Oxford University Hospitals NHS Foundation Trust, John Radcliffe Hospital, Headley Way Oxford, UK
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21
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The diversity of neuronal phenotypes in rodent and human autonomic ganglia. Cell Tissue Res 2020; 382:201-231. [PMID: 32930881 PMCID: PMC7584561 DOI: 10.1007/s00441-020-03279-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Accepted: 08/10/2020] [Indexed: 12/29/2022]
Abstract
Selective sympathetic and parasympathetic pathways that act on target organs represent the terminal actors in the neurobiology of homeostasis and often become compromised during a range of neurodegenerative and traumatic disorders. Here, we delineate several neurotransmitter and neuromodulator phenotypes found in diverse parasympathetic and sympathetic ganglia in humans and rodent species. The comparative approach reveals evolutionarily conserved and non-conserved phenotypic marker constellations. A developmental analysis examining the acquisition of selected neurotransmitter properties has provided a detailed, but still incomplete, understanding of the origins of a set of noradrenergic and cholinergic sympathetic neuron populations, found in the cervical and trunk region. A corresponding analysis examining cholinergic and nitrergic parasympathetic neurons in the head, and a range of pelvic neuron populations, with noradrenergic, cholinergic, nitrergic, and mixed transmitter phenotypes, remains open. Of particular interest are the molecular mechanisms and nuclear processes that are responsible for the correlated expression of the various genes required to achieve the noradrenergic phenotype, the segregation of cholinergic locus gene expression, and the regulation of genes that are necessary to generate a nitrergic phenotype. Unraveling the neuron population-specific expression of adhesion molecules, which are involved in axonal outgrowth, pathway selection, and synaptic organization, will advance the study of target-selective autonomic pathway generation.
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22
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Peroxisome proliferator-activated receptor-γ mediates the antihypertensive effects of acupuncture in spontaneously hypertensive rats. Neuroreport 2020; 31:952-958. [PMID: 32568773 DOI: 10.1097/wnr.0000000000001496] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
We investigated a central antihypertensive effect of acupuncture in rostral ventrolateral medulla (RVLM) in spontaneously hypertensive rats (SHRs). In total, 56 rats were randomly divided into seven groups as follows: the SHR group, SHR+acupuncture (SHR+Acu) group, SHR+nonacupuncture (SHR+Non-acu) group, GW9662+acupuncture (GW9662+Acu) group, GW9662+GW1929 group, GW9662 group, and 2% DMSO group (n = 8 per group). The whole eight Wistar-Kyoto rats were assigned to the WKY group. The acupuncture treatment lasting for 14 days was performed at the Taichong acupoint (LR3) or at a nonacupoint (non-acu) once daily. The peroxisome proliferator-activated receptor (PPAR)-γ agonist GW1929 and the PPAR-γ inhibitor GW9662 were microinjected by the brain stereotactic technique. Blood pressure was measured by the tail-cuff method. Sympathetic vasomotor activity was determined by implanting in a telemetry electrocardiogram radio transmitter. The expression of PPARs in the RVLM of the rats was detected using Western blot. We demonstrated that acupuncture attenuated blood pressure, heart rate, and sympathetic vasomotor activity in SHRs. The protein expression of PPAR-γ was significantly increased in SHRs treated with acupuncture. The antihypertensive effects of acupuncture in SHRs were abrogated by microinjection bilaterally into RVLM of GW9662. Microinjection of GW1929 mimicked the antihypertensive effect of acupuncture. PPAR-γ expression was negatively correlated with blood pressure and sympathetic vasomotor activity in SHRs treated with acupuncture. These results suggested that acupuncture promoted a central antihypertensive effect by increasing the expression of PPAR-γ in RVLM of SHRs.
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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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24
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Kalla M, Hao G, Tapoulal N, Tomek J, Liu K, Woodward L, Dall’Armellina E, Banning AP, Choudhury RP, Neubauer S, Kharbanda RK, Channon KM, Ajijola OA, Shivkumar K, Paterson DJ, Herring N. The cardiac sympathetic co-transmitter neuropeptide Y is pro-arrhythmic following ST-elevation myocardial infarction despite beta-blockade. Eur Heart J 2020; 41:2168-2179. [PMID: 31834357 PMCID: PMC7299634 DOI: 10.1093/eurheartj/ehz852] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/12/2019] [Revised: 08/29/2019] [Accepted: 11/12/2019] [Indexed: 01/29/2023] Open
Abstract
AIMS ST-elevation myocardial infarction is associated with high levels of cardiac sympathetic drive and release of the co-transmitter neuropeptide Y (NPY). We hypothesized that despite beta-blockade, NPY promotes arrhythmogenesis via ventricular myocyte receptors. METHODS AND RESULTS In 78 patients treated with primary percutaneous coronary intervention, sustained ventricular tachycardia (VT) or fibrillation (VF) occurred in 6 (7.7%) within 48 h. These patients had significantly (P < 0.05) higher venous NPY levels despite the absence of classical risk factors including late presentation, larger infarct size, and beta-blocker usage. Receiver operating curve identified an NPY threshold of 27.3 pg/mL with a sensitivity of 0.83 and a specificity of 0.71. RT-qPCR demonstrated the presence of NPY mRNA in both human and rat stellate ganglia. In the isolated Langendorff perfused rat heart, prolonged (10 Hz, 2 min) stimulation of the stellate ganglia caused significant NPY release. Despite maximal beta-blockade with metoprolol (10 μmol/L), optical mapping of ventricular voltage and calcium (using RH237 and Rhod2) demonstrated an increase in magnitude and shortening in duration of the calcium transient and a significant lowering of ventricular fibrillation threshold. These effects were prevented by the Y1 receptor antagonist BIBO3304 (1 μmol/L). Neuropeptide Y (250 nmol/L) significantly increased the incidence of VT/VF (60% vs. 10%) during experimental ST-elevation ischaemia and reperfusion compared to control, and this could also be prevented by BIBO3304. CONCLUSIONS The co-transmitter NPY is released during sympathetic stimulation and acts as a novel arrhythmic trigger. Drugs inhibiting the Y1 receptor work synergistically with beta-blockade as a new anti-arrhythmic therapy.
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Affiliation(s)
- Manish Kalla
- Department of Physiology, Anatomy and Genetics, Burdon Sanderson Cardiac Science Centre, University of Oxford, Parks Road, Oxford OX13PT, UK
- Department of Cardiovascular Medicine, John Radcliffe Hospital, University of Oxford, Oxford OX3 9DU, UK
| | - Guoliang Hao
- Department of Physiology, Anatomy and Genetics, Burdon Sanderson Cardiac Science Centre, University of Oxford, Parks Road, Oxford OX13PT, UK
| | - Nidi Tapoulal
- Department of Physiology, Anatomy and Genetics, Burdon Sanderson Cardiac Science Centre, University of Oxford, Parks Road, Oxford OX13PT, UK
| | - Jakub Tomek
- Department of Physiology, Anatomy and Genetics, Burdon Sanderson Cardiac Science Centre, University of Oxford, Parks Road, Oxford OX13PT, UK
| | - Kun Liu
- Department of Physiology, Anatomy and Genetics, Burdon Sanderson Cardiac Science Centre, University of Oxford, Parks Road, Oxford OX13PT, UK
| | - Lavinia Woodward
- Department of Physiology, Anatomy and Genetics, Burdon Sanderson Cardiac Science Centre, University of Oxford, Parks Road, Oxford OX13PT, UK
| | | | - Erica Dall’Armellina
- Department of Cardiovascular Medicine, John Radcliffe Hospital, University of Oxford, Oxford OX3 9DU, UK
| | - Adrian P Banning
- Department of Cardiovascular Medicine, John Radcliffe Hospital, University of Oxford, Oxford OX3 9DU, UK
| | - Robin P Choudhury
- Department of Cardiovascular Medicine, John Radcliffe Hospital, University of Oxford, Oxford OX3 9DU, UK
- Radcliffe Department of Medicine, Acute Vascular Imaging Centre, University of Oxford, Oxford OX3 9DU, UK
| | - Stefan Neubauer
- Department of Cardiovascular Medicine, John Radcliffe Hospital, University of Oxford, Oxford OX3 9DU, UK
| | - Rajesh K Kharbanda
- Department of Cardiovascular Medicine, John Radcliffe Hospital, University of Oxford, Oxford OX3 9DU, UK
| | - Keith M Channon
- Department of Cardiovascular Medicine, John Radcliffe Hospital, University of Oxford, Oxford OX3 9DU, UK
| | - Olujimi A Ajijola
- UCLA Cardiac Arrhythmia Center and Neurocardiology Research Center, Los Angeles, CA, USA
| | - Kalyanam Shivkumar
- UCLA Cardiac Arrhythmia Center and Neurocardiology Research Center, Los Angeles, CA, USA
| | - David J Paterson
- Department of Physiology, Anatomy and Genetics, Burdon Sanderson Cardiac Science Centre, University of Oxford, Parks Road, Oxford OX13PT, UK
| | - Neil Herring
- Department of Physiology, Anatomy and Genetics, Burdon Sanderson Cardiac Science Centre, University of Oxford, Parks Road, Oxford OX13PT, UK
- Department of Cardiovascular Medicine, John Radcliffe Hospital, University of Oxford, Oxford OX3 9DU, UK
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da Costa TSR, Masson GS, Eichler RADS, Silva JCDS, Lacchini S, Michelini LC. Training-Induced Deactivation of the AT 1 Receptor Pathway Drives Autonomic Control and Heart Remodeling During the Transition From the Pre- to Hypertensive Phase in Spontaneously Hypertensive Rats. Circ J 2020; 84:1294-1303. [PMID: 32522899 DOI: 10.1253/circj.cj-19-1161] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
BACKGROUND The effects of hypertension and exercise training (T) on the sequential interplay between renin-angiotensin system (RAS), autonomic control and heart remodeling during the development of hypertension in spontaneously hypertensive rats (SHR), was evaluated.Methods and Results:Time course changes of these parameters were recorded in 4-week-old SHR submitted to a T or sedentary (S) protocol. Wistar Kyoto rats served as controls. Hemodynamic recordings were obtained in conscious rats at experimental weeks 0, 1, 2, 4, and 8. The left ventricle (LV) was collected to evaluate RAS gene and protein expression, cardiomyocytes' hypertrophy and collagen accumulation. Pre-hypertensive SHR exhibited augmented AT1R gene expression; at 5 weeks, they presented with elevated pressure, increased LV angiotensinogen and ACE mRNA expression, followed by sympathoexcitation (from the 8thweek onwards). Marked AT1R protein content, myocytes's hypertrophy, collagen deposition and increased pressure variability were observed in 12-week-old sedentary SHR. In addition to attenuating all these effects, T activated Mas receptor expression augmented parasympathetic modulation of the heart, and delayed the onset and reduced the magnitude, but did not block the development of genetic hypertension. CONCLUSIONS The close temporal relationship between changes in the LV ACE-Ang II-AT1R axis, autonomic control and cardiac remodeling at both the establishment of hypertension and during exercise training reveals the essential role played by the AT1R pathway in driving cardiac remodeling and autonomic modulation during the transition from the pre- to hypertensive phase.
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Affiliation(s)
| | - Gustavo Santos Masson
- Department of Physiology and Biophysics, Biomedical Sciences Institute, University of Sao Paulo
| | | | | | - Silvia Lacchini
- Department of Anatomy, Biomedical Sciences Institute, University of Sao Paulo
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The α1D-adrenoreceptor antagonist BMY 7378 reverses cardiac hypertrophy in spontaneously hypertensive rats. J Hypertens 2020; 38:1496-1503. [PMID: 32195823 DOI: 10.1097/hjh.0000000000002412] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
OBJECTIVE The α1D-adrenoreceptor (α1D-AR) is involved in angiotensin II-induced vascular remodeling and hypertension. Whether α1D-AR plays a role in hypertension-associated cardiac hypertrophy is unclear. Here we investigated effects of BMY 7378, a selective α1D-AR antagonist, on cardiac status in aged spontaneously hypertensive rats (SHR). METHODS Male SHR were studied during the phase of developing hypertension (5 and 10 weeks old) and once hypertension was established (20 and 30 weeks old) to assess the evolution of cardiac hypertrophy. Age-matched WKY rats were studied as controls. Thirty-week-old SHR were treated for 4 weeks with BMY 7378 (10 mg/kg per day, o.a.), or captopril (angiotensin-converting enzyme inhibitor, 40 mg/kg per day, o.a.) (as a positive control). Blood pressure and cardiac function were measured in vivo, cardiac hypertrophy by histology, and α1D-AR protein expression by immunofluorescence. RESULTS By 30 weeks of age, SHR exhibited significant hypertension and cardiac hypertrophy. BMY 7378 and captopril decreased blood pressure and improved hemodynamic parameters and cardiac function in treated SHR vs. untreated SHR (P < 0.05). Histology showed increased cardiomyocyte size, fibrosis, and left ventricular hypertrophy in SHR hearts. BMY 7378 ameliorated fibrosis and cardiac hypertrophy, but had no effect on cardiomyocyte size in SHR. Effects of BMY 7378 were associated with increased α1D-AR protein expression in SHR. CONCLUSION Our data indicate that pharmacological antagonism of α1D-AR reduces blood pressure and associated cardiac hypertrophy in aged SHR. These findings suggest that the α1D-AR plays a pathophysiological role in the development of hypertension and cardiac target organ damage in SHR.
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Abstract
Hypertension represents an autonomic dysfunction, characterized by increased sympathetic and decreased parasympathetic cardiovascular tone leading to resting tachycardia. Therefore, studies assessing hypertension-associated changes in isolated cardiac tissues were conducted under electric field stimulation to stimulate the neurons. Herein, we characterize the influence of the autonomic neurotransmitter on the baseline atrial chronotropism of unpaced isolated right atria of normotensive Wistar rats (NWR) and spontaneously hypertensive rats (SHR). Our results revealed a resting bradycardia in tissues from SHR in comparison to NWR. The release of autonomic neurotransmitters, acetylcholine or norepinephrine, still occurs in the electrically unstimulated right atrium, after excision of the sympathetic nerve, which could explain differences in basal heart rate between NWR and SHR. Nicotine and the acetylcholinesterase inhibitor physostigmine reduced the chronotropism of right atria from either NWR or SHR. Conversely, the muscarinic receptor antagonist atropine did not affect the basal chronotropism of tissues from both strains. Furthermore, tyramine increased the chronotropism of NWR and SHR atria indicating availability of the neuronal stocks of noradrenaline. Although the monoamine uptake inhibitor cocaine increased right atrium chronotropism in both strains, the basal heart rate was not affected by the β-adrenoceptor antagonist propranolol. In summary, after acute section of the sympathetic nerve, autonomic neurotransmitters are still released either in resting conditions or upon pharmacological stimulation of right atria from both strains. Nevertheless, autonomic neurotransmission does not affect resting chronotropism, nor is the responsible for reduced basal heart rate of the isolated right atrium of hypertensive rats.
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Shanks J, de Morais SDB, Gao L, Zucker IH, Wang HJ. TRPV1 (Transient Receptor Potential Vanilloid 1) Cardiac Spinal Afferents Contribute to Hypertension in Spontaneous Hypertensive Rat. Hypertension 2019; 74:910-920. [PMID: 31422690 DOI: 10.1161/hypertensionaha.119.13285] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Hypertension is associated with increased sympathetic activity. A component of this sympathoexcitation may be driven by increased signaling from sensory endings from the heart to the autonomic control areas in the brain. This pathway mediates the so-called cardiac sympathetic afferent reflex, which is also activated by coronary ischemia or other nociceptive stimuli in the heart. The cardiac sympathetic afferent reflex has been shown to be enhanced in the heart failure state and in renal hypertension. However, little is known about its role in the development or progression of hypertension or the phenotype of the sensory endings involved. To investigate this, we used the selective afferent neurotoxin, resiniferatoxin (RTX) to chronically abolish the cardiac sympathetic afferent reflex in 2 models of hypertension; the spontaneous hypertensive rats (SHRs) and AngII (angiotensin II) infusion (240 ng/kg per min). Blood pressure (BP) was measured in conscious animals for 2 to 8 weeks post-RTX. Epidural application of RTX to the T1-T4 spinal segments prevented the further BP increase in 8-week-old SHR and lowered BP in 16-week-old SHR. RTX did not affect BP in Wistar-Kyoto normotensive rats nor in AngII-infused rats. Epicardial application of RTX (50 µg/mL) in 4-week-old SHR prevented the BP increase whereas this treatment does not lower BP in 16-week-old SHR. When RTX was administered into the L2-L5 spinal segments of 16-week-old SHR, no change in BP was observed. These findings indicate that signaling via thoracic afferent nerve fibers may contribute to the hypertension phenotype in the SHR but not in the Ang II infusion model of hypertension.
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Affiliation(s)
- Julia Shanks
- From the Department of Cellular and Integrative Physiology (J.S., S.D.B.d., L.G., I.H.Z., H.-J.W.), University of Nebraska Medical Center, Omaha, NE
| | - Sharon D B de Morais
- From the Department of Cellular and Integrative Physiology (J.S., S.D.B.d., L.G., I.H.Z., H.-J.W.), University of Nebraska Medical Center, Omaha, NE
| | - Lie Gao
- From the Department of Cellular and Integrative Physiology (J.S., S.D.B.d., L.G., I.H.Z., H.-J.W.), University of Nebraska Medical Center, Omaha, NE
| | - Irving H Zucker
- From the Department of Cellular and Integrative Physiology (J.S., S.D.B.d., L.G., I.H.Z., H.-J.W.), University of Nebraska Medical Center, Omaha, NE
| | - Han-Jun Wang
- From the Department of Cellular and Integrative Physiology (J.S., S.D.B.d., L.G., I.H.Z., H.-J.W.), University of Nebraska Medical Center, Omaha, NE.,Department of Anesthesiology (H.-J.W.), University of Nebraska Medical Center, Omaha, NE
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29
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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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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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31
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Impaired cardiorespiratory coupling in young normotensives with a family history of hypertension. J Hypertens 2018; 36:2157-2167. [DOI: 10.1097/hjh.0000000000001795] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Tan CMJ, Green P, Tapoulal N, Lewandowski AJ, Leeson P, Herring N. The Role of Neuropeptide Y in Cardiovascular Health and Disease. Front Physiol 2018; 9:1281. [PMID: 30283345 PMCID: PMC6157311 DOI: 10.3389/fphys.2018.01281] [Citation(s) in RCA: 115] [Impact Index Per Article: 19.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2018] [Accepted: 08/24/2018] [Indexed: 12/20/2022] Open
Abstract
Neuropeptide Y (NPY) is an abundant sympathetic co-transmitter, widely found in the central and peripheral nervous systems and with diverse roles in multiple physiological processes. In the cardiovascular system it is found in neurons supplying the vasculature, cardiomyocytes and endocardium, and is involved in physiological processes including vasoconstriction, cardiac remodeling, and angiogenesis. It is increasingly also implicated in cardiovascular disease pathogenesis, including hypertension, atherosclerosis, ischemia/infarction, arrhythmia, and heart failure. This review will focus on the physiological and pathogenic role of NPY in the cardiovascular system. After summarizing the NPY receptors which predominantly mediate cardiovascular actions, along with their signaling pathways, individual disease processes will be considered. A thorough understanding of these roles may allow therapeutic targeting of NPY and its receptors.
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Affiliation(s)
- Cheryl M J Tan
- Oxford Cardiovascular Clinical Research Facility, Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Peregrine Green
- Department of Physiology, Anatomy and Genetics, Burdon Sanderson Cardiac Science Centre, University of Oxford, Oxford, United Kingdom
| | - Nidi Tapoulal
- Department of Physiology, Anatomy and Genetics, Burdon Sanderson Cardiac Science Centre, University of Oxford, Oxford, United Kingdom
| | - Adam J Lewandowski
- Oxford Cardiovascular Clinical Research Facility, Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Paul Leeson
- Oxford Cardiovascular Clinical Research Facility, Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Neil Herring
- Department of Physiology, Anatomy and Genetics, Burdon Sanderson Cardiac Science Centre, University of Oxford, Oxford, United Kingdom
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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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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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NPY Impairs Cell Viability and Mitochondrial Membrane Potential Through Ca2+ and p38 Signaling Pathways in Neonatal Rat Cardiomyocytes. J Cardiovasc Pharmacol 2018; 70:52-59. [PMID: 28437279 DOI: 10.1097/fjc.0000000000000493] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
NPY is involved in stress cardiomyopathy. However, the associated mechanism for NPY-induced stress cardiomyopathy remains unclear. In this study, we aimed to explore potential cell signaling pathways that are related to NPY-mediated cell viability in neonatal rat cardiomyocytes. We found that NPY induced cell viability suppression in cultured cardiomyocytes in a dose-dependent manner. After NPY treatment, expression of CaN and p-CAMKII increased significantly, and phosphorylation of p38 but not ERK and JNK was changed. Moreover, NPY treatment significantly increased PGC-1α (the key factor of mitochondrial biogenesis and energy metabolism) expression but decreased mitochondrial membrane potential in cultured cardiomyocytes. More importantly, the blockage of CaN, CAMKII, and p38 signaling pathways by their inhibitors could rescue the reduced cell viability and mitochondrial membrane potential in NPY-treated cardiomyocytes. Collectively, our data demonstrated that NPY mediated cell viability and mitochondrial membrane potential in cardiomyocytes through CaN, CAMKII, and p38 signaling pathways.
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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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Dysregulation of Neuronal Ca2+ Channel Linked to Heightened Sympathetic Phenotype in Prohypertensive States. J Neurosci 2017; 36:8562-73. [PMID: 27535905 DOI: 10.1523/jneurosci.1059-16.2016] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2016] [Accepted: 05/27/2016] [Indexed: 11/21/2022] Open
Abstract
UNLABELLED Hypertension is associated with impaired nitric oxide (NO)-cyclic nucleotide (CN)-coupled intracellular calcium (Ca(2+)) homeostasis that enhances cardiac sympathetic neurotransmission. Because neuronal membrane Ca(2+) currents are reduced by NO-activated S-nitrosylation, we tested whether CNs affect membrane channel conductance directly in neurons isolated from the stellate ganglia of spontaneously hypertensive rats (SHRs) and their normotensive controls. Using voltage-clamp and cAMP-protein kinase A (PKA) FRET sensors, we hypothesized that impaired CN regulation provides a direct link to abnormal signaling of neuronal calcium channels in the SHR and that targeting cGMP can restore the channel phenotype. We found significantly larger whole-cell Ca(2+) currents from diseased neurons that were largely mediated by the N-type Ca(2+) channel (Cav2.2). Elevating cGMP restored the SHR Ca(2+) current to levels seen in normal neurons that were not affected by cGMP. cGMP also decreased cAMP levels and PKA activity in diseased neurons. In contrast, cAMP-PKA activity was increased in normal neurons, suggesting differential switching in phosphodiesterase (PDE) activity. PDE2A inhibition enhanced the Ca(2+) current in normal neurons to a conductance similar to that seen in SHR neurons, whereas the inhibitor slightly decreased the current in diseased neurons. Pharmacological evidence supported a switching from cGMP acting via PDE3 in control neurons to PDE2A in SHR neurons in the modulation of the Ca(2+) current. Our data suggest that a disturbance in the regulation of PDE-coupled CNs linked to N-type Ca(2+) channels is an early hallmark of the prohypertensive phenotype associated with intracellular Ca(2+) impairment underpinning sympathetic dysautonomia. SIGNIFICANCE STATEMENT Here, we identify dysregulation of cyclic-nucleotide (CN)-linked neuronal Ca(2+) channel activity that could provide the trigger for the enhanced sympathetic neurotransmission observed in the prohypertensive state. Furthermore, we provide evidence that increasing cGMP rescues the channel phenotype and restores ion channel activity to levels seen in normal neurons. We also observed CN cross-talk in sympathetic neurons that may be related to a differential switching in phosphodiesterase activity. The presence of these early molecular changes in asymptomatic, prohypertensive animals could facilitate the identification of novel therapeutic targets with which to modulate intracellular Ca(2+) Turning down the gain of sympathetic hyperresponsiveness in cardiovascular disease associated with sympathetic dysautonomia would have significant therapeutic utility.
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Shanks J, Herring N, Johnson E, Liu K, Li D, Paterson DJ. Overexpression of Sarcoendoplasmic Reticulum Calcium ATPase 2a Promotes Cardiac Sympathetic Neurotransmission via Abnormal Endoplasmic Reticulum and Mitochondria Ca 2+ Regulation. Hypertension 2017; 69:625-632. [PMID: 28223472 PMCID: PMC5344179 DOI: 10.1161/hypertensionaha.116.08507] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2016] [Revised: 10/11/2016] [Accepted: 01/18/2017] [Indexed: 12/18/2022]
Abstract
Supplemental Digital Content is available in the text. Reduced cardiomyocyte excitation–contraction coupling and downregulation of the SERCA2a (sarcoendoplasmic reticulum calcium ATPase 2a) is associated with heart failure. This has led to viral transgene upregulation of SERCA2a in cardiomyocytes as a treatment. We hypothesized that SERCA2a gene therapy expressed under a similar promiscuous cytomegalovirus promoter could also affect the cardiac sympathetic neural axis and promote sympathoexcitation. Stellate neurons were isolated from 90 to 120 g male, Sprague–Dawley, Wistar Kyoto, and spontaneously hypertensive rats. Neurons were infected with Ad-mCherry or Ad-mCherry-hATP2Aa (SERCA2a). Intracellular Ca2+ changes were measured using fura-2AM in response to KCl, caffeine, thapsigargin, and carbonylcyanide-p-trifluoromethoxyphenylhydrazine to mobilize intracellular Ca2+ stores. The effect of SERCA2a on neurotransmitter release was measured using [3H]-norepinephrine overflow from 340 to 360 g Sprague–Dawley rat atria in response to right stellate ganglia stimulation. Upregulation of SERCA2a resulted in greater neurotransmitter release in response to stellate stimulation compared with control (empty: 98.7±20.5 cpm, n=7; SERCA: 186.5±28.41 cpm, n=8; P<0.05). In isolated Sprague–Dawley rat stellate neurons, SERCA2a overexpression facilitated greater depolarization-induced Ca2+ transients (empty: 0.64±0.03 au, n=57; SERCA: 0.75±0.03 au, n=68; P<0.05), along with increased endoplasmic reticulum and mitochondria Ca2+ load. Similar results were observed in Wistar Kyoto and age-matched spontaneously hypertensive rats, despite no further increase in endoplasmic reticulum load being observed in the spontaneously hypertensive rat (spontaneously hypertensive rats: empty, 0.16±0.04 au, n=18; SERCA: 0.17±0.02 au, n=25). In conclusion, SERCA2a upregulation in cardiac sympathetic neurons resulted in increased neurotransmission and increased Ca2+ loading into intracellular stores. Whether the increased Ca2+ transient and neurotransmission after SERCA2A overexpression contributes to enhanced sympathoexcitation in heart failure patients remains to be determined.
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Affiliation(s)
- Julia Shanks
- From the Department of Physiology, Anatomy and Genetics, Burdon Sanderson Cardiac Science Centre and BHF Centre of Research Excellence, Oxford, United Kingdom (J.S., N.H., K.L., D.L., D.J.P.); and Sir William Dunn School of Pathology, Oxford, United Kingdom (E.J.)
| | - Neil Herring
- From the Department of Physiology, Anatomy and Genetics, Burdon Sanderson Cardiac Science Centre and BHF Centre of Research Excellence, Oxford, United Kingdom (J.S., N.H., K.L., D.L., D.J.P.); and Sir William Dunn School of Pathology, Oxford, United Kingdom (E.J.)
| | - Errin Johnson
- From the Department of Physiology, Anatomy and Genetics, Burdon Sanderson Cardiac Science Centre and BHF Centre of Research Excellence, Oxford, United Kingdom (J.S., N.H., K.L., D.L., D.J.P.); and Sir William Dunn School of Pathology, Oxford, United Kingdom (E.J.)
| | - Kun Liu
- From the Department of Physiology, Anatomy and Genetics, Burdon Sanderson Cardiac Science Centre and BHF Centre of Research Excellence, Oxford, United Kingdom (J.S., N.H., K.L., D.L., D.J.P.); and Sir William Dunn School of Pathology, Oxford, United Kingdom (E.J.)
| | - Dan Li
- From the Department of Physiology, Anatomy and Genetics, Burdon Sanderson Cardiac Science Centre and BHF Centre of Research Excellence, Oxford, United Kingdom (J.S., N.H., K.L., D.L., D.J.P.); and Sir William Dunn School of Pathology, Oxford, United Kingdom (E.J.)
| | - David J Paterson
- From the Department of Physiology, Anatomy and Genetics, Burdon Sanderson Cardiac Science Centre and BHF Centre of Research Excellence, Oxford, United Kingdom (J.S., N.H., K.L., D.L., D.J.P.); and Sir William Dunn School of Pathology, Oxford, United Kingdom (E.J.).
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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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Cobos-Puc LE, Sánchez-López A, Centurión D. Pharmacological analysis of the cardiac sympatho-inhibitory actions of moxonidine and agmatine in pithed spontaneously hypertensive rats. Eur J Pharmacol 2016; 791:25-36. [DOI: 10.1016/j.ejphar.2016.08.017] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2016] [Revised: 08/03/2016] [Accepted: 08/22/2016] [Indexed: 02/02/2023]
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Kawase H, Bando YK, Nishimura K, Aoyama M, Monji A, Murohara T. A dipeptidyl peptidase-4 inhibitor ameliorates hypertensive cardiac remodeling via angiotensin-II/sodium-proton pump exchanger-1 axis. J Mol Cell Cardiol 2016; 98:37-47. [DOI: 10.1016/j.yjmcc.2016.06.066] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/21/2016] [Revised: 06/26/2016] [Accepted: 06/28/2016] [Indexed: 10/21/2022]
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Kalla M, Herring N, Paterson DJ. Cardiac sympatho-vagal balance and ventricular arrhythmia. Auton Neurosci 2016; 199:29-37. [PMID: 27590099 PMCID: PMC5334443 DOI: 10.1016/j.autneu.2016.08.016] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2016] [Revised: 08/24/2016] [Accepted: 08/25/2016] [Indexed: 12/11/2022]
Abstract
A hallmark of cardiovascular disease is cardiac autonomic dysregulation. The phenotype of impaired parasympathetic responsiveness and sympathetic hyperactivity in experimental animal models is also well documented in large scale human studies in the setting of heart failure and myocardial infarction, and is predictive of morbidity and mortality. Despite advances in emergency revascularisation strategies for myocardial infarction, device therapy for heart failure and secondary prevention pharmacotherapies, mortality from malignant ventricular arrhythmia remains high. Patients at highest risk or those with haemodynamically significant ventricular arrhythmia can be treated with catheter ablation and implantable cardioverter defibrillators, but the morbidity and reduction in quality of life due to the burden of ventricular arrhythmia and shock therapy persists. Therefore, future therapies must aim to target the underlying pathophysiology that contributes to the generation of ventricular arrhythmia. This review explores recent advances in mechanistic research in both limbs of the autonomic nervous system and potential avenues for translation into clinical therapy. In addition, we also discuss the relationship of these findings in the context of the reported efficacy of current neuromodulatory strategies in the management of ventricular arrhythmia. We review advances in mechanistic research in the cardiac autonomic nervous system. This is discussed in relation to neuromodulatory therapy for ventricular arrhythmia. Neuromodulation therapies can influence both neurotransmitters and co-transmitters. This may therefore improve on conventional medical treatment.
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Affiliation(s)
| | - Neil Herring
- Corresponding author at: Burdon Sanderson Cardiac Science Centre, Dept. of Physiology, Anatomy and Genetics, University of Oxford, Parks Road, OX13PT, UK.Burdon Sanderson Cardiac Science CentreDept. of Physiology, Anatomy and GeneticsUniversity of OxfordParks RoadOX13PTUK
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Habecker BA, Anderson ME, Birren SJ, Fukuda K, Herring N, Hoover DB, Kanazawa H, Paterson DJ, Ripplinger CM. Molecular and cellular neurocardiology: development, and cellular and molecular adaptations to heart disease. J Physiol 2016; 594:3853-75. [PMID: 27060296 DOI: 10.1113/jp271840] [Citation(s) in RCA: 70] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2015] [Accepted: 03/15/2016] [Indexed: 12/12/2022] Open
Abstract
The nervous system and cardiovascular system develop in concert and are functionally interconnected in both health and disease. This white paper focuses on the cellular and molecular mechanisms that underlie neural-cardiac interactions during development, during normal physiological function in the mature system, and during pathological remodelling in cardiovascular disease. The content on each subject was contributed by experts, and we hope that this will provide a useful resource for newcomers to neurocardiology as well as aficionados.
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Affiliation(s)
- Beth A Habecker
- Department of Physiology and Pharmacology, Department of Medicine Division of Cardiovascular Medicine and Knight Cardiovascular Institute, Oregon Health and Science University, Portland, OR, 97239, USA
| | - Mark E Anderson
- Johns Hopkins Department of Medicine, Johns Hopkins School of Medicine, Baltimore, MD, 21287, USA
| | - Susan J Birren
- Department of Biology, Volen Center for Complex Systems, Brandeis University, Waltham, MA, 02453, USA
| | - Keiichi Fukuda
- Department of Cardiology, Keio University School of Medicine, 35-Shinanomachi, Shinjuku-ku, Tokyo, 160-8582, Japan
| | - Neil Herring
- Burdon Sanderson Cardiac Science Centre, Department of Physiology, Anatomy and Genetics, University of Oxford, Parks Road, Oxford, OX1 3PT, UK
| | - Donald B Hoover
- Department of Biomedical Sciences, Center of Excellence in Inflammation, Infectious Disease and Immunity, James H. Quillen College of Medicine, East Tennessee State University, Johnson City, TN, 37614, USA
| | - Hideaki Kanazawa
- Department of Cardiology, Keio University School of Medicine, 35-Shinanomachi, Shinjuku-ku, Tokyo, 160-8582, Japan
| | - David J Paterson
- Burdon Sanderson Cardiac Science Centre, Department of Physiology, Anatomy and Genetics, University of Oxford, Parks Road, Oxford, OX1 3PT, UK
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Nukada H, Baba M, Ogasawara S, McMorran D, Yagihashi S. Neuropathy in the spontaneously hypertensive rat: An electrophysiological and histological study. Muscle Nerve 2016; 54:756-62. [PMID: 26970072 DOI: 10.1002/mus.25098] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2014] [Revised: 02/24/2016] [Accepted: 03/03/2016] [Indexed: 02/04/2023]
Abstract
INTRODUCTION Hypertension is identified as a risk factor for development of polyneuropathy. In this study we examined nerve conduction and morphological alteration of peripheral nerves in spontaneously hypertensive rats (SHR). METHODS Motor nerve conduction velocity (MNCV) in the sciatic-tibial nerve and sensory nerve conduction velocity (SNCV) in the sural nerve were measured. Pathological investigations included spinal cord, dorsal root ganglion, and hindlimb nerves in SHR and Wistar-Kyoto rats (WKY) aged 4-64 weeks. RESULTS Blood pressure was significantly higher in SHR than WKY animals at 4 weeks and elevated further with aging. MNCV and SNCV were significantly slower in SHR compared with WKY after age 24 weeks. Prominent morphological changes in SHR nerves included axonal atrophy and myelin splitting. SHR also had endoneurial microangiopathy with reduplication of basement membrane. CONCLUSIONS SHR showed slowed nerve conduction velocity and pathological abnormalities of hindlimb nerves. Sustained severe hypertension may cause axonal atrophy and endoneurial microangiopathy. Muscle Nerve 54: 756-762, 2016.
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Affiliation(s)
- Hitoshi Nukada
- The Nukada Institute for Medical & Biological Research, 5-18 Inage-machi, Inage-ku, Chiba, 263-0035, Japan. .,Department of Medicine, Dunedin School of Medicine, University of Otago, Dunedin, New Zealand.
| | - Masayuki Baba
- Department of Neurology, Aomori Prefectural Central Hospital, Aomori, Japan
| | - Saori Ogasawara
- Department of Pathology and Molecular Medicine, Hirosaki University, Hirosaki, Japan
| | - Denise McMorran
- Department of Medicine, Dunedin School of Medicine, University of Otago, Dunedin, New Zealand
| | - Soroku Yagihashi
- Department of Pathology and Molecular Medicine, Hirosaki University, Hirosaki, Japan
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Moyes AJ, Stanford SC, Hosford PS, Hobbs AJ, Ramage AG. Raised arterial blood pressure in neurokinin-1 receptor-deficient mice (NK1R(-/-) ): evidence for a neural rather than a vascular mechanism. Exp Physiol 2016; 101:588-98. [PMID: 26876733 DOI: 10.1113/ep085347] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2015] [Accepted: 02/11/2016] [Indexed: 11/08/2022]
Abstract
NEW FINDINGS What is the central question of this study? Does genetic ablation of neurokinin-1 receptors alter arterial blood pressure? What is the main finding and its importance? NK1R(-/-) mice have increased mean arterial blood pressure, but without a concomitant change in vascular reactivity. This finding suggests that neurokinin-1 receptors play a role in the neural regulation of blood pressure. Mice with functional ablation of the neurokinin-1 receptor gene, Tacr1, (NK1R(-/-) ) express behavioural abnormalities equivalent to those seen in attention deficit hyperactivity disorder (ADHD). An established model of ADHD is the spontaneously hypertensive rat, which exhibits high blood pressure owing to increased central sympathetic drive. In light of the evidence that the neurokinin-1 receptor (NK1R) also influences cardiovascular haemodynamics, we have investigated whether NK1R(-/-) mice exhibit raised blood pressure. Cardiovascular parameters were recorded for 24 h in conscious mice using radiotelemetry. Vascular function was assessed in mesenteric resistance arteries by wire myography. The NK1R(-/-) mice exhibited a higher blood pressure than wild-type animals throughout the 24 h period. Heart rate and locomotor activity in NK1R(-/-) mice were higher than in wild-type mice during the night period (active phase), consistent with an ADHD-like phenotype, but not during the day. Mesenteric and renal arteries from NK1R(-/-) mice exhibited normal vascular function; the responses to vasoconstrictors (U46619 and phenylephrine) and the endothelium-dependent vasodilator, acetylcholine, were not altered in these animals, suggesting that the NK1R does not regulate vascular tone. Analysis of heart rate variability revealed a higher low-frequency to high-frequency ratio in NK1R(-/-) mice, indicative of increased cardiac sympathetic activity. We propose that the raised blood pressure in NK1R(-/-) mice could be due to a neural mechanism rather than a change in vascular reactivity. Further studies are required to understand this mechanism and to establish whether a subgroup of ADHD patients with polymorphism of the equivalent (TACR1) gene are affected in a similar way.
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Affiliation(s)
- Amie J Moyes
- The William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London, UK
| | - S Clare Stanford
- Department of Neuroscience, Physiology and Pharmacology, University College London, London, UK
| | - Patrick S Hosford
- Department of Neuroscience, Physiology and Pharmacology, University College London, London, UK
| | - Adrian J Hobbs
- The William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London, UK
| | - Andrew G Ramage
- Department of Neuroscience, Physiology and Pharmacology, University College London, London, UK
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Therapeutic evaluation of rutin in two-kidney one-clip model of renovascular hypertension in rat. Life Sci 2016; 150:89-94. [PMID: 26920631 DOI: 10.1016/j.lfs.2016.02.080] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2015] [Revised: 02/19/2016] [Accepted: 02/22/2016] [Indexed: 12/31/2022]
Abstract
AIM The current investigation, designed to investigate the role of rutin in two-kidney one-clip (2K1C) induced renovascular dysfunction associated with hypertension in rat. MAIN METHODS The renovascular hypertension was developed by the application of vascular clip on left renal artery in rats; the right kidney was kept as such throughout the experimental protocol. The rutin (200 and 300 mg/kg; p.o.) and aliskiren (50mg/kg; p.o.) were administered for 9 consecutive days. The battery of pathophysiological tests i.e., systolic pressure, diastolic pressure and heart rate were performed to assess the anti-hypertensive effect of rutin. In addition, changes of kidney weight/body weight (KW/BW) ratio along with plasma renin content and renal tissue biomarkers i.e., thiobarbituric acid reactive substance (TBAR) and reduced glutathione (GSH) levels were estimated. KEY FINDINGS The administration of rutin significantly (P<0.05) attenuated the 2K1C of left kidney induced elevated systolic and diastolic pressure in a dose dependent manner. In addition, it also reduces the ratio of KW/BW along with a decrease in plasma renin content, tissue TBARS and increase the GSH levels. There were no significant changes observed in heart rate. Similar results were observed in aliskiren treated group. SIGNIFICANCE The anti-hypertensive effect of rutin may be a useful herbal medicine for the management of hypertension due to its potential free radical scavenging, inhibition of lipid peroxidation and plasma renin inhibitory action.
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Zhu X, Gillespie DG, Jackson EK. NPY1-36 and PYY1-36 activate cardiac fibroblasts: an effect enhanced by genetic hypertension and inhibition of dipeptidyl peptidase 4. Am J Physiol Heart Circ Physiol 2015; 309:H1528-42. [PMID: 26371160 DOI: 10.1152/ajpheart.00070.2015] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/28/2015] [Accepted: 09/09/2015] [Indexed: 12/13/2022]
Abstract
Cardiac sympathetic nerves release neuropeptide Y (NPY)1-36, and peptide YY (PYY)1-36 is a circulating peptide; therefore, these PP-fold peptides could affect cardiac fibroblasts (CFs). We examined the effects of NPY1-36 and PYY1-36 on the proliferation of and collagen production ([(3)H]proline incorporation) by CFs isolated from Wistar-Kyoto (WKY) normotensive rats and spontaneously hypertensive rats (SHRs). Experiments were performed with and without sitagliptin, an inhibitor of dipeptidyl peptidase 4 [DPP4; an ectoenzyme that metabolizes NPY1-36 and PYY1-36 (Y1 receptor agonists) to NPY3-36 and PYY3-36 (inactive at Y1 receptors), respectively]. NPY1-36 and PYY1-36, but not NPY3-36 or PYY3-36, stimulated proliferation of CFs, and these effects were more potent than ANG II, enhanced by sitagliptin, blocked by BIBP3226 (Y1 receptor antagonist), and greater in SHR CFs. SHR CF membranes expressed more receptor for activated C kinase (RACK)1 [which scaffolds the Gi/phospholipase C (PLC)/PKC pathway] compared with WKY CF membranes. RACK1 knockdown (short hairpin RNA) and inhibition of Gi (pertussis toxin), PLC (U73122), and PKC (GF109203X) blocked the proliferative effects of NPY1-36. NPY1-36 and PYY1-36 stimulated collagen production more potently than did ANG II, and this was enhanced by sitagliptin and greater in SHR CFs. In conclusion, 1) NPY1-36 and PYY1-36, via the Y1 receptor/Gi/PLC/PKC pathway, activate CFs, and this pathway is enhanced in SHR CFs due to increased localization of RACK1 in membranes; and 2) DPP4 inhibition enhances the effects of NPY1-36 and PYY1-36 on CFs, likely by inhibiting the metabolism of NPY1-36 and PYY1-36. The implications are that endogenous NPY1-36 and PYY1-36 could adversely affect cardiac structure/function by activating CFs, and this may be exacerbated in genetic hypertension and by DPP4 inhibitors.
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Affiliation(s)
- Xiao Zhu
- Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - Delbert G Gillespie
- Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - Edwin K Jackson
- Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
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LI PENG, GONG JUEXIAO, SUN WEI, ZHOU BIN, KONG XIANGQING. Hexamethonium attenuates sympathetic activity and blood pressure in spontaneously hypertensive rats. Mol Med Rep 2015; 12:7116-22. [DOI: 10.3892/mmr.2015.4315] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2014] [Accepted: 07/29/2015] [Indexed: 11/05/2022] Open
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Lu CJ, Hao G, Nikiforova N, Larsen HE, Liu K, Crabtree MJ, Li D, Herring N, Paterson DJ. CAPON modulates neuronal calcium handling and cardiac sympathetic neurotransmission during dysautonomia in hypertension. Hypertension 2015; 65:1288-1297. [PMID: 25916729 DOI: 10.1161/hypertensionaha.115.05290] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2015] [Accepted: 04/03/2015] [Indexed: 02/07/2023]
Abstract
Genome-wide association studies implicate a variant in the neuronal nitric oxide synthase adaptor protein (CAPON) in electrocardiographic QT variation and sudden cardiac death. Interestingly, nitric oxide generated by neuronal NO synthase-1 reduces norepinephrine release; however, this pathway is downregulated in animal models of cardiovascular disease. Because sympathetic hyperactivity can trigger arrhythmia, is this neural phenotype linked to CAPON dysregulation? We hypothesized that CAPON resides in cardiac sympathetic neurons and is a part of the prediseased neuronal phenotype that modulates calcium handling and neurotransmission in dysautonomia. CAPON expression was significantly reduced in the stellate ganglia of spontaneously hypertensive rats before the development of hypertension compared with age-matched Wistar-Kyoto rats. The neuronal calcium current (ICa; n=8) and intracellular calcium transient ([Ca(2+)]i; n=16) were significantly larger in the spontaneously hypertensive rat than in Wistar-Kyoto rat (P<0.05). A novel noradrenergic specific vector (Ad.PRSx8-mCherry/CAPON) significantly upregulated CAPON expression, NO synthase-1 activity, and cGMP in spontaneously hypertensive rat neurons without altering NO synthase-1 levels. Neuronal ICa and [Ca(2+)]i were significantly reduced after CAPON transduction compared with the empty vector. In addition, Ad.PRSx8-mCherry/CAPON also reduced (3)H-norepinephrine release from spontaneously hypertensive rat atria (n=7). NO synthase-1 inhibition (AAAN, 10 μmol/L; n=6) reversed these effects compared with the empty virus alone. In conclusion, targeted upregulation of CAPON decreases cardiac sympathetic hyperactivity. Moreover, dysregulation of this adaptor protein in sympathetic neurons might further amplify the negative cardiac electrophysiological properties seen with CAPON mutations.
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Affiliation(s)
- Chieh-Ju Lu
- Department of Physiology, Anatomy and Genetics, Burdon Sanderson Cardiac Science Centre (C.-J.L., G.H., N.N., H.E.L., K.L., D.L., N.H., D.J.P.) and Radcliffe Department of Medicine, John Radcliffe Hospital (M.J.C.), University of Oxford, Oxford, United Kingdom
| | - Guoliang Hao
- Department of Physiology, Anatomy and Genetics, Burdon Sanderson Cardiac Science Centre (C.-J.L., G.H., N.N., H.E.L., K.L., D.L., N.H., D.J.P.) and Radcliffe Department of Medicine, John Radcliffe Hospital (M.J.C.), University of Oxford, Oxford, United Kingdom
| | - Natalia Nikiforova
- Department of Physiology, Anatomy and Genetics, Burdon Sanderson Cardiac Science Centre (C.-J.L., G.H., N.N., H.E.L., K.L., D.L., N.H., D.J.P.) and Radcliffe Department of Medicine, John Radcliffe Hospital (M.J.C.), University of Oxford, Oxford, United Kingdom
| | - Hege E Larsen
- Department of Physiology, Anatomy and Genetics, Burdon Sanderson Cardiac Science Centre (C.-J.L., G.H., N.N., H.E.L., K.L., D.L., N.H., D.J.P.) and Radcliffe Department of Medicine, John Radcliffe Hospital (M.J.C.), University of Oxford, Oxford, United Kingdom
| | - Kun Liu
- Department of Physiology, Anatomy and Genetics, Burdon Sanderson Cardiac Science Centre (C.-J.L., G.H., N.N., H.E.L., K.L., D.L., N.H., D.J.P.) and Radcliffe Department of Medicine, John Radcliffe Hospital (M.J.C.), University of Oxford, Oxford, United Kingdom
| | - Mark J Crabtree
- Department of Physiology, Anatomy and Genetics, Burdon Sanderson Cardiac Science Centre (C.-J.L., G.H., N.N., H.E.L., K.L., D.L., N.H., D.J.P.) and Radcliffe Department of Medicine, John Radcliffe Hospital (M.J.C.), University of Oxford, Oxford, United Kingdom
| | - Dan Li
- Department of Physiology, Anatomy and Genetics, Burdon Sanderson Cardiac Science Centre (C.-J.L., G.H., N.N., H.E.L., K.L., D.L., N.H., D.J.P.) and Radcliffe Department of Medicine, John Radcliffe Hospital (M.J.C.), University of Oxford, Oxford, United Kingdom
| | - Neil Herring
- Department of Physiology, Anatomy and Genetics, Burdon Sanderson Cardiac Science Centre (C.-J.L., G.H., N.N., H.E.L., K.L., D.L., N.H., D.J.P.) and Radcliffe Department of Medicine, John Radcliffe Hospital (M.J.C.), University of Oxford, Oxford, United Kingdom
| | - David J Paterson
- Department of Physiology, Anatomy and Genetics, Burdon Sanderson Cardiac Science Centre (C.-J.L., G.H., N.N., H.E.L., K.L., D.L., N.H., D.J.P.) and Radcliffe Department of Medicine, John Radcliffe Hospital (M.J.C.), University of Oxford, Oxford, United Kingdom
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Jackson EK, Mi Z, Tofovic SP, Gillespie DG. Effect of dipeptidyl peptidase 4 inhibition on arterial blood pressure is context dependent. Hypertension 2015; 65:238-49. [PMID: 25368027 PMCID: PMC4268428 DOI: 10.1161/hypertensionaha.114.04631] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
UNLABELLED Because the effects of dipeptidyl peptidase 4 (DPP4) inhibitors on blood pressure are controversial, we examined the long-term effects of sitagliptin (80 mg/kg per day) on blood pressure (radiotelemetry) in spontaneously hypertensive rats (SHR), Wistar-Kyoto rats, and Zucker Diabetic-Sprague Dawley rats (metabolic syndrome model). In SHR, chronic (3 weeks) sitagliptin significantly increased systolic, mean, and diastolic blood pressures by 10.3, 9.2, and 7.9 mm Hg, respectively, a response abolished by coadministration of BIBP3226 (2 mg/kg per day; selective Y1-receptor antagonist). Sitagliptin also significantly increased blood pressure in SHR treated with hydralazine (vasodilator; 25 mg/kg per day) or enalapril (angiotensin-converting enzyme inhibitor; 10 mg/kg per day). In Wistar-Kyoto rats, chronic sitagliptin slightly decreased systolic, mean, and diastolic blood pressures (-1.8, -1.1, and -0.4 mm Hg, respectively). In Zucker Diabetic-Sprague Dawley rats, chronic sitagliptin decreased systolic, mean, and diastolic blood pressures by -7.7, -5.8, and -4.3 mm Hg, respectively, and did not alter the antihypertensive effects of chronic enalapril. Because DPP4 inhibitors impair the metabolism of neuropeptide Y1-36 (NPY1-36; Y1-receptor agonist) and glucagon-like peptide (GLP)-1(7-36)NH2 (GLP-1 receptor agonist), we examined renovascular responses to NPY1-36 and GLP-1(7-36)NH2 in isolated perfused SHR and Zucker Diabetic-Sprague Dawley kidneys pretreated with norepinephrine (to induce basal tone). In Zucker Diabetic-Sprague Dawley kidneys, NPY1-36 and GLP-1(7-36)NH2 exerted little, if any, effect on renovascular tone. In contrast, in SHR kidneys, both NPY1-36 and GLP-1(7-36)NH2 elicited potent and efficacious vasoconstriction. IN CONCLUSION (1) The effects of DPP4 inhibitors on blood pressure are context dependent; (2) The context-dependent effects of DPP4 inhibitors are due in part to differential renovascular responses to DPP4’s most important substrates (NPY1–36 and GLP-1(7–36)NH2) [corrected]; (3) Y1 receptor antagonists may prevent the prohypertensive and possibly augment the antihypertensive effects of DPP4 inhibitors.
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Affiliation(s)
- Edwin K Jackson
- From the Department of Pharmacology and Chemical Biology, University of Pittsburgh, School of Medicine, PA.
| | - Zaichuan Mi
- From the Department of Pharmacology and Chemical Biology, University of Pittsburgh, School of Medicine, PA
| | - Stevan P Tofovic
- From the Department of Pharmacology and Chemical Biology, University of Pittsburgh, School of Medicine, PA
| | - Delbert G Gillespie
- From the Department of Pharmacology and Chemical Biology, University of Pittsburgh, School of Medicine, PA
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