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Soriano JE, Hudelle R, Squair JW, Mahe L, Amir S, Gautier M, Puchalt VP, Barraud Q, Phillips AA, Courtine G. Longitudinal interrogation of sympathetic neural circuits and hemodynamics in preclinical models. Nat Protoc 2023; 18:340-373. [PMID: 36418397 DOI: 10.1038/s41596-022-00764-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Accepted: 05/27/2022] [Indexed: 11/24/2022]
Abstract
Neurological disorders, including spinal cord injury, result in hemodynamic instability due to the disruption of supraspinal projections to the sympathetic circuits located in the spinal cord. We recently developed a preclinical model that allows the identification of the topology and dynamics through which sympathetic circuits modulate hemodynamics, supporting the development of a neuroprosthetic baroreflex that precisely controls blood pressure in rats, monkeys and humans with spinal cord injuries. Here, we describe the continuous monitoring of arterial blood pressure and sympathetic nerve activity over several months in preclinical models of chronic neurological disorders using commercially available telemetry technologies, as well as optogenetic and neuronal tract-tracing procedures specifically adapted to the sympathetic circuitry. Using a blueprint to construct a negative-pressure chamber, the approach enables the reproduction, in rats, of well-controlled and reproducible episodes of hypotension-mimicking orthostatic challenges already used in humans. Blood pressure variations can thus be directly induced and linked to the molecular, functional and anatomical properties of specific neurons in the brainstem, spinal cord and ganglia. Each procedure can be completed in under 2 h, while the construction of the negative-pressure chamber requires up to 1 week. With training, individuals with a basic understanding of cardiovascular physiology, engineering or neuroscience can collect longitudinal recordings of hemodynamics and sympathetic nerve activity over several months.
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Affiliation(s)
- Jan Elaine Soriano
- Neuro-X Institute, School of Life Sciences, Swiss Federal Institute of Technology (EPFL), Lausanne, Switzerland.,Department of Clinical Neuroscience, Lausanne University Hospital (CHUV) and University of Lausanne (UNIL), Lausanne, Switzerland.,Defitech Center for Interventional Neurotherapies (.NeuroRestore), EPFL/CHUV/UNIL, Lausanne, Switzerland.,Department of Physiology and Pharmacology, Clinical Neurosciences, Cardiac Sciences, Hotchkiss Brain Institute, Libin Cardiovascular Institute, Cumming School of Medicine, University of Calgary, Calgary, Canada
| | - Rémi Hudelle
- Neuro-X Institute, School of Life Sciences, Swiss Federal Institute of Technology (EPFL), Lausanne, Switzerland.,Department of Clinical Neuroscience, Lausanne University Hospital (CHUV) and University of Lausanne (UNIL), Lausanne, Switzerland.,Defitech Center for Interventional Neurotherapies (.NeuroRestore), EPFL/CHUV/UNIL, Lausanne, Switzerland
| | - Jordan W Squair
- Neuro-X Institute, School of Life Sciences, Swiss Federal Institute of Technology (EPFL), Lausanne, Switzerland.,Department of Clinical Neuroscience, Lausanne University Hospital (CHUV) and University of Lausanne (UNIL), Lausanne, Switzerland.,Defitech Center for Interventional Neurotherapies (.NeuroRestore), EPFL/CHUV/UNIL, Lausanne, Switzerland.,Department of Physiology and Pharmacology, Clinical Neurosciences, Cardiac Sciences, Hotchkiss Brain Institute, Libin Cardiovascular Institute, Cumming School of Medicine, University of Calgary, Calgary, Canada
| | - Lois Mahe
- Neuro-X Institute, School of Life Sciences, Swiss Federal Institute of Technology (EPFL), Lausanne, Switzerland.,Department of Clinical Neuroscience, Lausanne University Hospital (CHUV) and University of Lausanne (UNIL), Lausanne, Switzerland.,Defitech Center for Interventional Neurotherapies (.NeuroRestore), EPFL/CHUV/UNIL, Lausanne, Switzerland
| | - Suje Amir
- Neuro-X Institute, School of Life Sciences, Swiss Federal Institute of Technology (EPFL), Lausanne, Switzerland.,Department of Clinical Neuroscience, Lausanne University Hospital (CHUV) and University of Lausanne (UNIL), Lausanne, Switzerland.,Defitech Center for Interventional Neurotherapies (.NeuroRestore), EPFL/CHUV/UNIL, Lausanne, Switzerland
| | - Matthieu Gautier
- Neuro-X Institute, School of Life Sciences, Swiss Federal Institute of Technology (EPFL), Lausanne, Switzerland.,Department of Clinical Neuroscience, Lausanne University Hospital (CHUV) and University of Lausanne (UNIL), Lausanne, Switzerland.,Defitech Center for Interventional Neurotherapies (.NeuroRestore), EPFL/CHUV/UNIL, Lausanne, Switzerland
| | - Victor Perez Puchalt
- Neuro-X Institute, School of Life Sciences, Swiss Federal Institute of Technology (EPFL), Lausanne, Switzerland.,Department of Clinical Neuroscience, Lausanne University Hospital (CHUV) and University of Lausanne (UNIL), Lausanne, Switzerland.,Defitech Center for Interventional Neurotherapies (.NeuroRestore), EPFL/CHUV/UNIL, Lausanne, Switzerland
| | - Quentin Barraud
- Neuro-X Institute, School of Life Sciences, Swiss Federal Institute of Technology (EPFL), Lausanne, Switzerland.,Department of Clinical Neuroscience, Lausanne University Hospital (CHUV) and University of Lausanne (UNIL), Lausanne, Switzerland.,Defitech Center for Interventional Neurotherapies (.NeuroRestore), EPFL/CHUV/UNIL, Lausanne, Switzerland
| | - Aaron A Phillips
- Department of Physiology and Pharmacology, Clinical Neurosciences, Cardiac Sciences, Hotchkiss Brain Institute, Libin Cardiovascular Institute, Cumming School of Medicine, University of Calgary, Calgary, Canada.
| | - Gregoire Courtine
- Neuro-X Institute, School of Life Sciences, Swiss Federal Institute of Technology (EPFL), Lausanne, Switzerland. .,Department of Clinical Neuroscience, Lausanne University Hospital (CHUV) and University of Lausanne (UNIL), Lausanne, Switzerland. .,Defitech Center for Interventional Neurotherapies (.NeuroRestore), EPFL/CHUV/UNIL, Lausanne, Switzerland.
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2
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Vinit S, Michel-Flutot P, Mansart A, Fayssoil A. Effects of C2 hemisection on respiratory and cardiovascular functions in rats. Neural Regen Res 2023; 18:428-433. [PMID: 35900441 PMCID: PMC9396504 DOI: 10.4103/1673-5374.346469] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
High cervical spinal cord injuries induce permanent neuromotor and autonomic deficits. These injuries impact both central respiratory and cardiovascular functions through modulation of the sympathetic nervous system. So far, cardiovascular studies have focused on models of complete contusion or transection at the lower cervical and thoracic levels and diaphragm activity evaluations using invasive methods. The present study aimed to evaluate the impact of C2 hemisection on different parameters representing vital functions (i.e., respiratory function, cardiovascular, and renal filtration parameters) at the moment of injury and 7 days post-injury in rats. No ventilatory parameters evaluated by plethysmography were impacted during quiet breathing after 7 days post-injury, whereas permanent diaphragm hemiplegia was observed by ultrasound and confirmed by diaphragmatic electromyography in anesthetized rats. Interestingly, the mean arterial pressure was reduced immediately after C2 hemisection, with complete compensation at 7 days post-injury. Renal filtration was unaffected at 7 days post-injury; however, remnant systolic dysfunction characterized by a reduced left ventricular ejection fraction persisted at 7 days post-injury. Taken together, these results demonstrated that following C2 hemisection, diaphragm activity and systolic function are impacted up to 7 days post-injury, whereas the respiratory and cardiovascular systems display vast adaptation to maintain ventilatory parameters and blood pressure homeostasis, with the latter likely sustained by the remaining descending sympathetic inputs spared by the initial injury. A better broad characterization of the physiopathology of high cervical spinal cord injuries covering a longer time period post-injury could be beneficial for understanding evaluations of putative therapeutics to further increase cardiorespiratory recovery.
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Bacova BS, Andelova K, Sykora M, Egan Benova T, Barancik M, Kurahara LH, Tribulova N. Does Myocardial Atrophy Represent Anti-Arrhythmic Phenotype? Biomedicines 2022; 10:2819. [PMID: 36359339 PMCID: PMC9687767 DOI: 10.3390/biomedicines10112819] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Revised: 10/31/2022] [Accepted: 11/02/2022] [Indexed: 11/30/2023] Open
Abstract
This review focuses on cardiac atrophy resulting from mechanical or metabolic unloading due to various conditions, describing some mechanisms and discussing possible strategies or interventions to prevent, attenuate or reverse myocardial atrophy. An improved awareness of these conditions and an increased focus on the identification of mechanisms and therapeutic targets may facilitate the development of the effective treatment or reversion for cardiac atrophy. It appears that a decrement in the left ventricular mass itself may be the central component in cardiac deconditioning, which avoids the occurrence of life-threatening arrhythmias. The depressed myocardial contractility of atrophied myocardium along with the upregulation of electrical coupling protein, connexin43, the maintenance of its topology, and enhanced PKCƐ signalling may be involved in the anti-arrhythmic phenotype. Meanwhile, persistent myocardial atrophy accompanied by oxidative stress and inflammation, as well as extracellular matrix fibrosis, may lead to severe cardiac dysfunction, and heart failure. Data in the literature suggest that the prevention of heart failure via the attenuation or reversion of myocardial atrophy is possible, although this requires further research.
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Affiliation(s)
| | - Katarina Andelova
- Centre of Experimental Medicine, Slovak Academy of Sciences, 84104 Bratislava, Slovakia
| | - Matus Sykora
- Centre of Experimental Medicine, Slovak Academy of Sciences, 84104 Bratislava, Slovakia
| | - Tamara Egan Benova
- Centre of Experimental Medicine, Slovak Academy of Sciences, 84104 Bratislava, Slovakia
| | - Miroslav Barancik
- Centre of Experimental Medicine, Slovak Academy of Sciences, 84104 Bratislava, Slovakia
| | - Lin Hai Kurahara
- Department of Cardiovascular Physiology, Faculty of Medicine, Kagawa University, Miki-cho 761-0793, Japan
| | - Narcis Tribulova
- Centre of Experimental Medicine, Slovak Academy of Sciences, 84104 Bratislava, Slovakia
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4
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Ahmadian M, Williams AM, Mannozzi J, Konecny F, Hoiland RL, Wainman L, Erskine E, Duffy J, Manouchehri N, So K, Tauh K, Sala-Mercado JA, Shortt K, Fisk S, Kim KT, Streijger F, Foster GE, Kwon BK, O’Leary DS, West CR. A cross-species validation of single-beat metrics of cardiac contractility. J Physiol 2022; 600:4779-4806. [PMID: 36121759 PMCID: PMC9669232 DOI: 10.1113/jp283319] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Accepted: 09/02/2022] [Indexed: 12/24/2022] Open
Abstract
The assessment of left ventricular (LV) contractility in animal models is useful in various experimental paradigms, yet obtaining such measures is inherently challenging and surgically invasive. In a cross-species study using small and large animals, we comprehensively tested the agreement and validity of multiple single-beat surrogate metrics of LV contractility against the field-standard metrics derived from inferior vena cava occlusion (IVCO). Fifty-six rats, 27 minipigs and 11 conscious dogs underwent LV and arterial catheterization and were assessed for a range of single-beat metrics of LV contractility. All single-beat metrics were tested for the various underlying assumptions required to be considered a valid metric of cardiac contractility, including load-independency, sensitivity to inotropic stimulation, and ability to diagnose contractile dysfunction in cardiac disease. Of all examined single-beat metrics, only LV maximal pressure normalized to end-diastolic volume (EDV), end-systolic pressure normalized to EDV, and the maximal rate of rise of the LV pressure normalized to EDV showed a moderate-to-excellent agreement with their IVCO-derived reference measure and met all the underlying assumptions required to be considered as a valid cardiac contractile metric in both rodents and large-animal models. Our findings demonstrate that single-beat metrics can be used as a valid, reliable method to quantify cardiac contractile function in basic/preclinical experiments utilizing small- and large-animal models KEY POINTS: Validating and comparing indices of cardiac contractility that avoid caval occlusion would offer considerable advantages for the field of cardiovascular physiology. We comprehensively test the underlying assumptions of multiple single-beat indices of cardiac contractility in rodents and translate these findings to pigs and conscious dogs. We show that when performing caval occlusion is unfeasible, single-beat metrics can be utilized to accurately quantify cardiac inotropic function in basic and preclinical research employing various small and large animal species. We report that maximal left-ventricular (LV)-pressure normalized to end-diastolic volume (EDV), LV end-systolic pressure normalized to EDV and the maximal rate of rise of the LV pressure waveform normalized to EDV are the best three single-beat metrics to measure cardiac inotropic function in both small- and large-animal models.
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Affiliation(s)
- Mehdi Ahmadian
- School of Kinesiology, Faculty of Education, University of British Columbia, Vancouver, BC, Canada
- International Collaboration on Repair Discoveries, University of British Columbia, Vancouver, BC, Canada
- Centre for Chronic Disease Prevention and Management, University of British Columbia, Kelowna, BC, Canada
| | - Alexandra M. Williams
- International Collaboration on Repair Discoveries, University of British Columbia, Vancouver, BC, Canada
- Department of Cellular and Physiological Sciences, Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada
| | - Joseph Mannozzi
- Department of Physiology, School of Medicine, Wayne State University, Detroit, MI 48009
| | - Filip Konecny
- Transonic Scisense Inc., London, ON, Canada
- MaRS Centre Toronto Medical Discovery Tower, 3rd Floor, 101 College Street, M5G 1L7, Toronto, Ontario, Canada
| | - Ryan L. Hoiland
- International Collaboration on Repair Discoveries, University of British Columbia, Vancouver, BC, Canada
- Department of Cellular and Physiological Sciences, Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada
- Department of Anesthesiology, Pharmacology and Therapeutics, Faculty of Medicine, Vancouver General Hospital, 899 West 12th Avenue, University of British Columbia, Vancouver, BC, Canada, V5Z 1M9
| | - Liisa Wainman
- International Collaboration on Repair Discoveries, University of British Columbia, Vancouver, BC, Canada
- Centre for Chronic Disease Prevention and Management, University of British Columbia, Kelowna, BC, Canada
- Department of Cellular and Physiological Sciences, Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada
| | - Erin Erskine
- International Collaboration on Repair Discoveries, University of British Columbia, Vancouver, BC, Canada
- Centre for Chronic Disease Prevention and Management, University of British Columbia, Kelowna, BC, Canada
- Department of Cellular and Physiological Sciences, Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada
| | - Jennifer Duffy
- International Collaboration on Repair Discoveries, University of British Columbia, Vancouver, BC, Canada
- Centre for Chronic Disease Prevention and Management, University of British Columbia, Kelowna, BC, Canada
- Department of Cellular and Physiological Sciences, Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada
| | - Neda Manouchehri
- International Collaboration on Repair Discoveries, University of British Columbia, Vancouver, BC, Canada
| | - Kitty So
- International Collaboration on Repair Discoveries, University of British Columbia, Vancouver, BC, Canada
| | - Keerit Tauh
- International Collaboration on Repair Discoveries, University of British Columbia, Vancouver, BC, Canada
| | | | - Katelyn Shortt
- International Collaboration on Repair Discoveries, University of British Columbia, Vancouver, BC, Canada
| | - Shera Fisk
- International Collaboration on Repair Discoveries, University of British Columbia, Vancouver, BC, Canada
| | - Kyoung-Tae Kim
- International Collaboration on Repair Discoveries, University of British Columbia, Vancouver, BC, Canada
- Department of Neurosurgery, School of Medicine, Kyungpook National University Hospital, Daegu, South Korea
| | - Femke Streijger
- International Collaboration on Repair Discoveries, University of British Columbia, Vancouver, BC, Canada
| | - Glen E. Foster
- Centre for Heart, Lung, & Vascular Health, School of Health and Exercise Sciences, University of British Columbia Okanagan, 3333 University Way, Kelowna, BC, V1V1V7
| | - Brian K. Kwon
- International Collaboration on Repair Discoveries, University of British Columbia, Vancouver, BC, Canada
| | - Donal S. O’Leary
- Department of Physiology, School of Medicine, Wayne State University, Detroit, MI 48009
| | - Christopher R. West
- International Collaboration on Repair Discoveries, University of British Columbia, Vancouver, BC, Canada
- Centre for Chronic Disease Prevention and Management, University of British Columbia, Kelowna, BC, Canada
- Department of Cellular and Physiological Sciences, Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada
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5
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Fossey MPM, Balthazaar SJT, Squair JW, Williams AM, Poormasjedi-Meibod MS, Nightingale TE, Erskine E, Hayes B, Ahmadian M, Jackson GS, Hunter DV, Currie KD, Tsang TSM, Walter M, Little JP, Ramer MS, Krassioukov AV, West CR. Spinal cord injury impairs cardiac function due to impaired bulbospinal sympathetic control. Nat Commun 2022; 13:1382. [PMID: 35296681 PMCID: PMC8927412 DOI: 10.1038/s41467-022-29066-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Accepted: 02/20/2022] [Indexed: 02/08/2023] Open
Abstract
Spinal cord injury chronically alters cardiac structure and function and is associated with increased odds for cardiovascular disease. Here, we investigate the cardiac consequences of spinal cord injury on the acute-to-chronic continuum, and the contribution of altered bulbospinal sympathetic control to the decline in cardiac function following spinal cord injury. By combining experimental rat models of spinal cord injury with prospective clinical studies, we demonstrate that spinal cord injury causes a rapid and sustained reduction in left ventricular contractile function that precedes structural changes. In rodents, we experimentally demonstrate that this decline in left ventricular contractile function following spinal cord injury is underpinned by interrupted bulbospinal sympathetic control. In humans, we find that activation of the sympathetic circuitry below the level of spinal cord injury causes an immediate increase in systolic function. Our findings highlight the importance for early interventions to mitigate the cardiac functional decline following spinal cord injury. By combining experimental models with prospective clinical studies, the authors show that spinal cord injury causes a rapid reduction in cardiac function that precedes structural changes, and that the loss of descending sympathetic control is the major cause of reduced cardiac function following spinal cord injury.
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Affiliation(s)
- Mary P M Fossey
- International Collaboration on Repair Discoveries (ICORD), University of British Columbia, Vancouver, BC, Canada.,Experimental Medicine, Department of Medicine, Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada
| | - Shane J T Balthazaar
- International Collaboration on Repair Discoveries (ICORD), University of British Columbia, Vancouver, BC, Canada.,Experimental Medicine, Department of Medicine, Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada
| | - Jordan W Squair
- International Collaboration on Repair Discoveries (ICORD), University of British Columbia, Vancouver, BC, Canada
| | - Alexandra M Williams
- International Collaboration on Repair Discoveries (ICORD), University of British Columbia, Vancouver, BC, Canada.,Department of Cellular and Physiological Sciences, Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada
| | | | - Tom E Nightingale
- International Collaboration on Repair Discoveries (ICORD), University of British Columbia, Vancouver, BC, Canada.,School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham, Birmingham, UK.,Centre for Trauma Sciences Research, University of Birmingham, Edgabaston, Birmingham, UK
| | - Erin Erskine
- International Collaboration on Repair Discoveries (ICORD), University of British Columbia, Vancouver, BC, Canada.,Department of Cellular and Physiological Sciences, Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada
| | - Brian Hayes
- International Collaboration on Repair Discoveries (ICORD), University of British Columbia, Vancouver, BC, Canada
| | - Mehdi Ahmadian
- International Collaboration on Repair Discoveries (ICORD), University of British Columbia, Vancouver, BC, Canada.,School of Kinesiology, Faculty of Education, University of British Columbia, Vancouver, BC, Canada
| | - Garett S Jackson
- Faculty of Health and Social Development, University of British Columbia, Kelowna, BC, Canada
| | - Diana V Hunter
- International Collaboration on Repair Discoveries (ICORD), University of British Columbia, Vancouver, BC, Canada
| | - Katharine D Currie
- International Collaboration on Repair Discoveries (ICORD), University of British Columbia, Vancouver, BC, Canada
| | - Teresa S M Tsang
- Division of Cardiology, University of British Columbia, Vancouver General and University of British Columbia Hospital Echocardiography Department, Vancouver, BC, Canada
| | - Matthias Walter
- International Collaboration on Repair Discoveries (ICORD), University of British Columbia, Vancouver, BC, Canada.,Department of Urology, University Hospital Basel, University of Basel, Basel, Switzerland
| | - Jonathan P Little
- School of Health and Exercise Sciences, University of British Columbia, Kelowna, BC, Canada
| | - Matt S Ramer
- International Collaboration on Repair Discoveries (ICORD), University of British Columbia, Vancouver, BC, Canada.,Department of Zoology, Faculty of Science, University of British Columbia, Vancouver, BC, Canada
| | - Andrei V Krassioukov
- International Collaboration on Repair Discoveries (ICORD), University of British Columbia, Vancouver, BC, Canada. .,Experimental Medicine, Department of Medicine, Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada. .,Division of Physical Medicine and Rehabilitation, Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada. .,GF Strong Rehabilitation Centre, Vancouver Coastal Health, Vancouver, BC, Canada.
| | - Christopher R West
- International Collaboration on Repair Discoveries (ICORD), University of British Columbia, Vancouver, BC, Canada. .,Department of Cellular and Physiological Sciences, Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada.
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6
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Development of a Spinal Cord Injury Model Permissive to Study the Cardiovascular Effects of Rehabilitation Approaches Designed to Induce Neuroplasticity. BIOLOGY 2021; 10:biology10101006. [PMID: 34681105 PMCID: PMC8533334 DOI: 10.3390/biology10101006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/01/2021] [Revised: 09/23/2021] [Accepted: 09/29/2021] [Indexed: 11/24/2022]
Abstract
Simple Summary People living with high-level spinal cord injury experience worse cardiovascular health than the general population. In most spinal cord injuries, there are some remaining functioning pathways leading from the brain through the spinal cord to the organs and muscles, but not enough to sustain normal levels of function. Recently, therapies that aim to increase the strength of connections in these remaining pathways have shown great potential in restoring walking, hand, and breathing function in the spinal cord injured population. In order to test these therapies for their effects on cardiovascular function, we developed a new type of spinal cord injury rat model that spares enough pathways for these therapies to act upon but still produces measurable reductions in heart and blood vessel function that can be targeted with interventions/treatments. Abstract As primary medical care for spinal cord injury (SCI) has improved over the last decades there are more individuals living with neurologically incomplete (vs. complete) cervical injuries. For these individuals, a number of promising therapies are being actively researched in pre-clinical settings that seek to strengthen the remaining spinal pathways with a view to improve motor function. To date, few, if any, of these interventions have been tested for their effectiveness to improve autonomic and cardiovascular (CV) function. As a first step to testing such therapies, we aimed to develop a model that has sufficient sparing of descending sympathetic pathways for these interventions to target yet induces robust CV impairment. Twenty-six Wistar rats were assigned to SCI (n = 13) or naïve (n = 13) groups. Animals were injured at the T3 spinal segment with 300 kdyn of force. Fourteen days post-SCI, left ventricular (LV) and arterial catheterization was performed to assess in vivo cardiac and hemodynamic function. Spinal cord lesion characteristics along with sparing in catecholaminergic and serotonergic projections were determined via immunohistochemistry. SCI produced a decrease in mean arterial pressure of 17 ± 3 mmHg (p < 0.001) and left ventricular contractility (end-systolic elastance) of 0.7 ± 0.1 mmHg/µL (p < 0.001). Our novel SCI model produced significant decreases in cardiac and hemodynamic function while preserving 33 ± 9% of white matter at the injury epicenter, which we believe makes it a useful pre-clinical model of SCI to study rehabilitation approaches designed to induce neuroplasticity.
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7
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Hayes BD, Fossey MPM, Poormasjedi-Meibod MS, Erskine E, Soriano JE, Scott B, Rosentreter R, Granville DJ, Phillips AA, West CR. Experimental high thoracic spinal cord injury impairs the cardiac and cerebrovascular response to orthostatic challenge in rats. Am J Physiol Heart Circ Physiol 2021; 321:H716-H727. [PMID: 34448635 DOI: 10.1152/ajpheart.00239.2021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Accepted: 08/24/2021] [Indexed: 11/22/2022]
Abstract
Spinal cord injury (SCI) impairs the cardiovascular responses to postural challenge, leading to the development of orthostatic hypotension (OH). Here, we apply lower body negative pressure (LBNP) to rodents with high-level SCI to demonstrate the usefulness of LBNP as a model for experimental OH studies, and to explore the effect of simulated OH on cardiovascular and cerebrovascular function following SCI. Male Wistar rats (n = 34) were subjected to a sham or T3-SCI surgery and survived into the chronic period postinjury (i.e., 8 wk). Cardiac function was tracked via ultrasound pre- to post-SCI to demonstrate the clinical utility of our model. At study termination, we conducted left-ventricular (LV) catheterization and insonated the middle cerebral artery to investigate the hemodynamic, cardiac, and cerebrovascular response to a mild dose of LBNP that is sufficient to mimic clinically defined OH in rats with T3-SCI but not sham animals. In response to mimicked OH, there was a greater decline in stroke volume, cardiac output, maximal LV pressure, and blood pressure in SCI compared with sham (P < 0.034), whereas heart rate was increased in sham but decreased in SCI (P < 0.029). SCI animals also had an exaggerated reduction in peak, minimum and mean middle cerebral artery flow, for a given change in blood pressure, in response to LBNP (P < 0.033), implying impaired dynamic cerebral autoregulation. Using a preclinical SCI model of OH, we demonstrate that complete high thoracic SCI impairs the cardiac response to OH and disrupts dynamic cerebral autoregulation.NEW & NOTEWORTHY This is the first use of LBNP to interrogate the cardiac and cerebrovascular responses to simulated OH in a preclinical study of SCI. Here, we demonstrate the utility of our simulated OH model and use it to demonstrate that SCI impairs the cardiac response to simulated OH and disrupts dynamic cerebrovascular autoregulation.
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Affiliation(s)
- Brian D Hayes
- International Collaboration on Repair Discoveries, University of British Columbia, Vancouver, British Columbia, Canada
- School of Kinesiology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Mary Pauline Mona Fossey
- International Collaboration on Repair Discoveries, University of British Columbia, Vancouver, British Columbia, Canada
- Experimental Medicine, Department of Medicine, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada
| | | | - Erin Erskine
- International Collaboration on Repair Discoveries, University of British Columbia, Vancouver, British Columbia, Canada
- Department of Cellular and Physiological Sciences, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada
| | - Jan Elaine Soriano
- Departments of Physiology and Pharmacology, Cardiac Sciences, Clinical Neurosciences, Libin Cardiovascular Institute, Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Berkeley Scott
- Departments of Physiology and Pharmacology, Cardiac Sciences, Clinical Neurosciences, Libin Cardiovascular Institute, Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Ryan Rosentreter
- Departments of Physiology and Pharmacology, Cardiac Sciences, Clinical Neurosciences, Libin Cardiovascular Institute, Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - David J Granville
- International Collaboration on Repair Discoveries, University of British Columbia, Vancouver, British Columbia, Canada
- Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, British Columbia, Canada
| | - Aaron A Phillips
- Departments of Physiology and Pharmacology, Cardiac Sciences, Clinical Neurosciences, Libin Cardiovascular Institute, Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Christopher R West
- International Collaboration on Repair Discoveries, University of British Columbia, Vancouver, British Columbia, Canada
- Department of Cellular and Physiological Sciences, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada
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8
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Williams AM, Manouchehri N, Erskine E, Tauh K, So K, Shortt K, Webster M, Fisk S, Billingsley A, Munro A, Tigchelaar S, Streijger F, Kim KT, Kwon BK, West CR. Cardio-centric hemodynamic management improves spinal cord oxygenation and mitigates hemorrhage in acute spinal cord injury. Nat Commun 2020; 11:5209. [PMID: 33060602 PMCID: PMC7562705 DOI: 10.1038/s41467-020-18905-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2020] [Accepted: 09/14/2020] [Indexed: 12/29/2022] Open
Abstract
Chronic high-thoracic and cervical spinal cord injury (SCI) results in a complex phenotype of cardiovascular consequences, including impaired left ventricular (LV) contractility. Here, we aim to determine whether such dysfunction manifests immediately post-injury, and if so, whether correcting impaired contractility can improve spinal cord oxygenation (SCO2), blood flow (SCBF) and metabolism. Using a porcine model of T2 SCI, we assess LV end-systolic elastance (contractility) via invasive pressure-volume catheterization, monitor intraparenchymal SCO2 and SCBF with fiberoptic oxygen sensors and laser-Doppler flowmetry, respectively, and quantify spinal cord metabolites with microdialysis. We demonstrate that high-thoracic SCI acutely impairs cardiac contractility and substantially reduces SCO2 and SCBF within the first hours post-injury. Utilizing the same model, we next show that augmenting LV contractility with the β-agonist dobutamine increases SCO2 and SCBF more effectively than vasopressor therapy, whilst also mitigating increased anaerobic metabolism and hemorrhage in the injured cord. Finally, in pigs with T2 SCI survived for 12 weeks post-injury, we confirm that acute hemodynamic management with dobutamine appears to preserve cardiac function and improve hemodynamic outcomes in the chronic setting. Our data support that cardio-centric hemodynamic management represents an advantageous alternative to the current clinical standard of vasopressor therapy for acute traumatic SCI.
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Affiliation(s)
- Alexandra M Williams
- International Collaboration On Repair Discoveries (ICORD), University of British Columbia, Vancouver, BC, Canada.,Department of Cellular and Physiological Sciences, Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada
| | - Neda Manouchehri
- International Collaboration On Repair Discoveries (ICORD), University of British Columbia, Vancouver, BC, Canada
| | - Erin Erskine
- International Collaboration On Repair Discoveries (ICORD), University of British Columbia, Vancouver, BC, Canada.,Department of Cellular and Physiological Sciences, Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada
| | - Keerit Tauh
- International Collaboration On Repair Discoveries (ICORD), University of British Columbia, Vancouver, BC, Canada
| | - Kitty So
- International Collaboration On Repair Discoveries (ICORD), University of British Columbia, Vancouver, BC, Canada
| | - Katelyn Shortt
- International Collaboration On Repair Discoveries (ICORD), University of British Columbia, Vancouver, BC, Canada
| | - Megan Webster
- International Collaboration On Repair Discoveries (ICORD), University of British Columbia, Vancouver, BC, Canada
| | - Shera Fisk
- International Collaboration On Repair Discoveries (ICORD), University of British Columbia, Vancouver, BC, Canada
| | - Avril Billingsley
- International Collaboration On Repair Discoveries (ICORD), University of British Columbia, Vancouver, BC, Canada
| | - Alex Munro
- International Collaboration On Repair Discoveries (ICORD), University of British Columbia, Vancouver, BC, Canada
| | - Seth Tigchelaar
- International Collaboration On Repair Discoveries (ICORD), University of British Columbia, Vancouver, BC, Canada
| | - Femke Streijger
- International Collaboration On Repair Discoveries (ICORD), University of British Columbia, Vancouver, BC, Canada
| | - Kyoung-Tae Kim
- International Collaboration On Repair Discoveries (ICORD), University of British Columbia, Vancouver, BC, Canada.,Department of Neurosurgery, School of Medicine, Kyungpook National University Hospital, Daegu, South Korea
| | - Brian K Kwon
- International Collaboration On Repair Discoveries (ICORD), University of British Columbia, Vancouver, BC, Canada.,Vancouver Spine Surgery Institute, Department of Orthopaedics, University of British Columbia, Vancouver, BC, Canada
| | - Christopher R West
- International Collaboration On Repair Discoveries (ICORD), University of British Columbia, Vancouver, BC, Canada. .,Department of Cellular and Physiological Sciences, Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada.
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9
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Järve A, Qadri F, Todiras M, Schmolke S, Bader M. Angiotensin-II receptor type Ia does not contribute to cardiac atrophy following high-thoracic spinal cord injury in mice. Exp Physiol 2020; 105:1316-1325. [PMID: 32515106 DOI: 10.1113/ep088378] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2019] [Accepted: 06/03/2020] [Indexed: 12/27/2022]
Abstract
NEW FINDINGS What is the central question of this study? What is the role of the renin-angiotensin system with angiotensin II acting via its receptor AT1a in spinal cord injury-induced cardiac atrophy? What is the main finding and its importance? Knockout of AT1a did not protect mice that had undergone thoracic level 4 transection from cardiac atrophy. There were no histopathological signs but there was reduced load-dependent left ventricular function (lower stroke volume and cardiac output) with preserved ejection fraction. ABSTRACT Spinal cord injury (SCI) leads to cardiac atrophy often accompanied by functional deficits. The renin-angiotensin system (RAS) with angiotensin II (AngII) signalling via its receptor AT1a might contribute to cardiac atrophy post-SCI. We performed spinal cord transection at thoracic level T4 (T4-Tx) or sham-operation in female wild-type mice (WT, n = 27) and mice deficient in AT1a (Agtr1a-/- , n = 27). Echocardiography (0, 7, 21 and 28 days post-SCI) and histology and gene expression analyses at 1 and 2 months post-SCI were performed. We found cardiac atrophy post-SCI: reduced heart weight, reduced estimated left ventricular mass in Agtr1a-/- , and reduced cardiomyocyte diameter in WT mice. Although, the latter as well as stroke volume (SV) and cardiac output (CO) were reduced in Agtr1a-/- mice already at baseline, cardiomyocyte diameter was even smaller in injured Agtr1a-/- mice compared to injured WT mice. SV and CO were reduced in WT mice post-SCI. Ejection fraction and fractional shortening were preserved post-SCI in both genotypes. There were no histological signs of fibrosis and pathology in the cardiac sections of either genotype post-SCI. Gene expression of Agtr1a showed a trend for up-regulation at 2 months post-SCI; angiotensinogen was up-regulated at 2 month post-SCI in both genotypes. AngII receptor type 2 (Agtr2) was up- and down-regulated at 1 and 2 months post-SCI in WT mice, respectively, and Ang-(1-7) receptor (Mas) at 1 and 2 months post-SCI. Atrogin-1/MAFbx and MuRF1, atrophy markers, were not significantly up-regulated post-SCI. Our data show that lack of AT1a does not protect from cardiac atrophy post-SCI.
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Affiliation(s)
- Anne Järve
- Max-Delbrück-Center for Molecular Medicine in the Helmholtz Association (MDC), Berlin, Germany.,DZHK (German Center for Cardiovascular Research), Partner Site Berlin, Berlin, Germany
| | - Fatimunnisa Qadri
- Max-Delbrück-Center for Molecular Medicine in the Helmholtz Association (MDC), Berlin, Germany
| | - Mihail Todiras
- Max-Delbrück-Center for Molecular Medicine in the Helmholtz Association (MDC), Berlin, Germany.,Nicolae Testemițanu State University of Medicine and Pharmacy, Chisinau, Moldova
| | - Shirley Schmolke
- Max-Delbrück-Center for Molecular Medicine in the Helmholtz Association (MDC), Berlin, Germany
| | - Michael Bader
- Max-Delbrück-Center for Molecular Medicine in the Helmholtz Association (MDC), Berlin, Germany.,DZHK (German Center for Cardiovascular Research), Partner Site Berlin, Berlin, Germany.,Charité Universitätsmedizin Berlin, Berlin, Germany.,Institute for Biology, University of Lübeck, Lübeck, Germany
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10
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Protein Degradome of Spinal Cord Injury: Biomarkers and Potential Therapeutic Targets. Mol Neurobiol 2020; 57:2702-2726. [PMID: 32328876 DOI: 10.1007/s12035-020-01916-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Accepted: 03/31/2020] [Indexed: 12/13/2022]
Abstract
Degradomics is a proteomics sub-discipline whose goal is to identify and characterize protease-substrate repertoires. With the aim of deciphering and characterizing key signature breakdown products, degradomics emerged to define encryptic biomarker neoproteins specific to certain disease processes. Remarkable improvements in structural and analytical experimental methodologies as evident in research investigating cellular behavior in neuroscience and cancer have allowed the identification of specific degradomes, increasing our knowledge about proteases and their regulators and substrates along with their implications in health and disease. A physiologic balance between protein synthesis and degradation is sought with the activation of proteolytic enzymes such as calpains, caspases, cathepsins, and matrix metalloproteinases. Proteolysis is essential for development, growth, and regeneration; however, inappropriate and uncontrolled activation of the proteolytic system renders the diseased tissue susceptible to further neurotoxic processes. In this article, we aim to review the protease-substrate repertoires as well as emerging therapeutic interventions in spinal cord injury at the degradomic level. Several protease substrates and their breakdown products, essential for the neuronal structural integrity and functional capacity, have been characterized in neurotrauma including cytoskeletal proteins, neuronal extracellular matrix glycoproteins, cell junction proteins, and ion channels. Therefore, targeting exaggerated protease activity provides a potentially effective therapeutic approach in the management of protease-mediated neurotoxicity in reducing the extent of damage secondary to spinal cord injury.
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11
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Sachdeva R, Krassioukov AV, Bucksot JE, Hays SA. Acute Cardiovascular Responses to Vagus Nerve Stimulation after Experimental Spinal Cord Injury. J Neurotrauma 2020; 37:1149-1155. [PMID: 31973660 DOI: 10.1089/neu.2019.6828] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Pairing vagus nerve stimulation (VNS) with rehabilitation has emerged as a potential strategy to enhance plasticity and improve recovery in a range of neurological disorders. A recent study highlights the therapeutic promise of VNS in promoting motor recovery after spinal cord injury (SCI). We investigated the safety of acute VNS in a rat model of chronic SCI. We measured the cardiovascular response to various VNS paradigms following chronic high-thoracic SCI that is known to deleteriously impact cardiovascular control. Dose-response experiments with continuous VNS revealed an SCI-dependent increase in sensitivity for heart rate (HR) and blood pressure (BP) compared with controls. A clinically relevant intermittent VNS resulted in transient reduction in HR in rats with SCI; however, BP remained unaltered. In all experiments, the effect lasted only while the VNS stimulus train was present, as HR and BP restored to baseline values as soon as VNS ended. No prolonged episodes of persisting hypotension were seen in either group. Further, VNS did not trigger autonomic dysreflexia or exacerbate the severity of autonomic dysreflexia when induced during or after stimulation sessions. Overall, these findings provide initial evidence that intermittent VNS at parameters used for targeted plasticity therapy (30 Hz, 0.8 mA) appears safe and supports further investigation of this potential therapy for use following SCI.
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Affiliation(s)
- Rahul Sachdeva
- International Collaboration on Repair Discoveries (ICORD), Division of Physical Medicine and Rehabilitation, University of British Columbia, Vancouver, British Columbia, Canada.,Department of Medicine, Division of Physical Medicine and Rehabilitation, University of British Columbia, Vancouver, British Columbia, Canada
| | - Andrei V Krassioukov
- International Collaboration on Repair Discoveries (ICORD), Division of Physical Medicine and Rehabilitation, University of British Columbia, Vancouver, British Columbia, Canada.,Department of Medicine, Division of Physical Medicine and Rehabilitation, University of British Columbia, Vancouver, British Columbia, Canada.,G.F. Strong Rehabilitation Center, Vancouver Coastal Health, Vancouver, British Columbia, Canada
| | - Jesse E Bucksot
- Erik Jonsson School of Engineering and Computer Science, The University of Texas at Dallas, Richardson, Texas, USA
| | - Seth A Hays
- Erik Jonsson School of Engineering and Computer Science, The University of Texas at Dallas, Richardson, Texas, USA.,Texas Biomedical Device Center, The University of Texas at Dallas, Richardson, Texas, USA.,School of Behavioral Brain Sciences, The University of Texas at Dallas, Richardson, Texas, USA
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12
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Järve A, Qadri F, Todiras M, Schmolke S, Alenina N, Bader M. Angiotensin-(1-7) Receptor Mas Deficiency Does Not Exacerbate Cardiac Atrophy Following High-Level Spinal Cord Injury in Mice. Front Physiol 2020; 11:203. [PMID: 32226394 PMCID: PMC7080696 DOI: 10.3389/fphys.2020.00203] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2019] [Accepted: 02/21/2020] [Indexed: 11/13/2022] Open
Abstract
Experimental spinal cord injury (SCI) causes a morphological and functional deterioration of the heart, in which the renin–angiotensin system (RAS) might play a role. The recently discovered non-canonical axis of RAS with angiotensin-(1–7) and its receptor Mas, which is associated with cardioprotection could be essential to prevent damage to the heart following SCI. We investigated the cardiac consequences of SCI and the role of Mas in female wild-type (WT, n = 22) and mice deficient of Mas (Mas–/–, n = 25) which underwent spinal cord transection at thoracic level T4 (T4-Tx) or sham-operation by echocardiography (0, 7, 21, and 28 days post-SCI), histology and gene expression analysis at 1 or 2 months post-SCI. We found left ventricular mass reduction with preserved ejection fraction (EF) and fractional shortening in WT as well as Mas–/– mice. Cardiac output was reduced in Mas–/– mice, whereas stroke volume (SV) was reduced in WT T4-Tx mice. Echocardiographic indices did not differ between the genotypes. Smaller heart weight (HW) and smaller cardiomyocyte diameter at 1 month post-SCI compared to sham mice was independent of genotype. The muscle-specific E3 ubiquitin ligases Atrogin-1/MAFbx and MuRF1 were upregulated or showed a trend for upregulation in WT mice at 2 months post-SCI, respectively. Angiotensinogen gene expression was upregulated at 1 month post-SCI and angiotensin II receptor type 2 downregulated at 2 month post-SCI in Mas–/– mice. Mas was downregulated post-SCI. Cardiac atrophy following SCI, not exacerbated by lack of Mas, is a physiological reaction as there were no signs of cardiac pathology and dysfunction.
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Affiliation(s)
- Anne Järve
- Max Delbrück Center for Molecular Medicine, Helmholtz Association of German Research Centers, Berlin, Germany.,Partner Site Berlin, German Center for Cardiovascular Research, Berlin, Germany
| | - Fatimunnisa Qadri
- Max Delbrück Center for Molecular Medicine, Helmholtz Association of German Research Centers, Berlin, Germany
| | - Mihail Todiras
- Max Delbrück Center for Molecular Medicine, Helmholtz Association of German Research Centers, Berlin, Germany.,Nicolae Testemiţanu State University of Medicine and Pharmacy, Chişinãu, Moldova
| | - Shirley Schmolke
- Max Delbrück Center for Molecular Medicine, Helmholtz Association of German Research Centers, Berlin, Germany
| | - Natalia Alenina
- Max Delbrück Center for Molecular Medicine, Helmholtz Association of German Research Centers, Berlin, Germany.,Partner Site Berlin, German Center for Cardiovascular Research, Berlin, Germany
| | - Michael Bader
- Max Delbrück Center for Molecular Medicine, Helmholtz Association of German Research Centers, Berlin, Germany.,Partner Site Berlin, German Center for Cardiovascular Research, Berlin, Germany.,Charité Universitätsmedizin Berlin, Berlin, Germany.,Institute for Biology, University of Lübeck, Lübeck, Germany
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13
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West CR, Poormasjedi-Meibod MS, Manouchehri N, Williams AM, Erskine EL, Webster M, Fisk S, Morrison C, Short K, So K, Cheung A, Streijger F, Kwon BK. A porcine model for studying the cardiovascular consequences of high-thoracic spinal cord injury. J Physiol 2020; 598:929-942. [PMID: 31876952 DOI: 10.1113/jp278451] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2019] [Accepted: 12/24/2019] [Indexed: 11/08/2022] Open
Abstract
KEY POINTS We have developed a novel porcine model of high-thoracic midline contusion spinal cord injury (SCI) at the T2 spinal level. We describe this model and the ensuing cardiovascular and neurohormonal responses, and demonstrate the model is efficacious for studying clinically relevant cardiovascular dysfunction post-SCI. We demonstrate that the high-thoracic SCI model, but not a low-thoracic SCI model, induces persistent hypotension along with a gradual reduction in plasma noradrenaline and increases in plasma aldosterone and angiotensin II. We additionally conducted a proof-of-concept long-term (12 weeks) survival study in animals with T2 contusion SCI demonstrating the potential utility of this model for not only acute experimentation but also long-term drug studies prior to translation to the clinic. ABSTRACT Cardiovascular disease is a leading cause of morbidity and mortality in the spinal cord injury (SCI) population, especially in those with high-thoracic or cervical SCI. With this in mind, we aimed to develop a large animal (porcine) model of high-thoracic (T2 level) contusion SCI and compare the haemodynamic and neurohormonal responses of this injury against a low-thoracic (T10 level) model. Ten Yorkshire pigs were randomly subjected to 20 cm weight drop contusion SCI at either the T2 or the T10 spinal level. Systolic blood pressure (SBP), mean arterial pressure (MAP) and heart rate (HR) were continuously monitored until 4 h post-SCI. Plasma noradrenaline (NA), aldosterone and angiotensin II (ANGII) were measured pre-SCI and at 30, 60, 120 and 240 min post-SCI. Additionally, two Yucatan pigs were subjected to T2-SCI and survived up to 12 weeks post-injury to demonstrate the efficacy of this model for long-term survival studies. Immediately after T2-SCI, SBP, MAP and HR increased (P < 0.0001). Between decompression (5 min post-SCI) and 30 min post-decompression in T2-SCI, SBP and MAP were lower than pre-SCI (P < 0.038). At 3 and 4 h after T2-SCI, SBP remained lower than pre-SCI (P = 0.048). After T10-SCI, haemodynamic indices remained largely unaffected. Plasma NA was lower in T2- vs. T10-SCI post-SCI, whilst aldosterone and ANGII were higher. Both chronically injured pigs demonstrated a vast reduction in SBP at 12 weeks post-SCI. Our model of T2-SCI causes a rapid and sustained alteration in neurohormonal control and cardiovascular function, which does not occur in the T10 model.
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Affiliation(s)
- Christopher R West
- International Collaboration on Repair Discoveries, University of British Columbia, Vancouver, Canada.,Department of Cellular and Physiological Sciences, Faculty of Medicine, University of British Columbia, Vancouver, Canada
| | - Malihe-Sadat Poormasjedi-Meibod
- International Collaboration on Repair Discoveries, University of British Columbia, Vancouver, Canada.,Department of Cellular and Physiological Sciences, Faculty of Medicine, University of British Columbia, Vancouver, Canada
| | - Neda Manouchehri
- International Collaboration on Repair Discoveries, University of British Columbia, Vancouver, Canada
| | - Alexandra M Williams
- International Collaboration on Repair Discoveries, University of British Columbia, Vancouver, Canada.,Department of Cellular and Physiological Sciences, Faculty of Medicine, University of British Columbia, Vancouver, Canada
| | - Erin L Erskine
- International Collaboration on Repair Discoveries, University of British Columbia, Vancouver, Canada
| | - Megan Webster
- International Collaboration on Repair Discoveries, University of British Columbia, Vancouver, Canada
| | - Shera Fisk
- International Collaboration on Repair Discoveries, University of British Columbia, Vancouver, Canada
| | - Charlotte Morrison
- International Collaboration on Repair Discoveries, University of British Columbia, Vancouver, Canada
| | - Katelyn Short
- International Collaboration on Repair Discoveries, University of British Columbia, Vancouver, Canada
| | - Kitty So
- International Collaboration on Repair Discoveries, University of British Columbia, Vancouver, Canada
| | - Amanda Cheung
- International Collaboration on Repair Discoveries, University of British Columbia, Vancouver, Canada
| | - Femke Streijger
- International Collaboration on Repair Discoveries, University of British Columbia, Vancouver, Canada
| | - Brian K Kwon
- International Collaboration on Repair Discoveries, University of British Columbia, Vancouver, Canada.,Vancouver Spine Surgery Institute, Department of Orthopedics, University of British Columbia, Vancouver, Canada
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14
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Sachdeva R, Hutton G, Marwaha AS, Krassioukov AV. Morphological maladaptations in sympathetic preganglionic neurons following an experimental high-thoracic spinal cord injury. Exp Neurol 2020; 327:113235. [PMID: 32044331 DOI: 10.1016/j.expneurol.2020.113235] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2019] [Revised: 01/15/2020] [Accepted: 02/06/2020] [Indexed: 10/25/2022]
Abstract
Spinal cord injury (SCI) disrupts the supraspinal vasomotor pathways to sympathetic preganglionic neurons (SPNs) leading to impaired blood pressure (BP) control that often results in episodes of autonomic dysreflexia and orthostatic hypotension. The physiological cardiovascular consequences of SCI are largely attributed to the plastic changes in spinal SPNs induced by their partial deafferentation. While multiple studies have investigated the morphological changes in SPNs following SCI with contrasting reports. Here we investigated the morphological changes in SPNs rostral and caudal to a high thoracic (T3) SCI at 1-, 4- and 8-weeks post injury. SPNs were identified using Nicotinamide adenine dinucleotide hydrogen phosphate-diaphorase (NADPH- diaphorase) staining and were quantified for soma size and various dendritic measurements. We show that rostral to the lesion, soma size was increased at 1 week along with increased dendritic arbor. The total dendritic length was also increased at chronic stage (8 weeks post SCI). Caudal to the lesion, the soma size or dendritic lengths did not change with SCI. However, dendritic branching was enhanced within a week post SCI and remained elevated throughout the chronic stages. These findings demonstrate that SPNs undergo significant structural changes form sub-acute to chronic stages post-SCI that likely determines their functional consequences. These changes are discussed in context of physiological cardiovascular outcomes post-SCI.
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Affiliation(s)
- Rahul Sachdeva
- International Collaboration on Repair Discoveries (ICORD), University of British Columbia, Vancouver, Canada; Department of Medicine, Division of Physical Medicine and Rehabilitation, University of British Columbia, Vancouver, Canada
| | - Gillian Hutton
- International Collaboration on Repair Discoveries (ICORD), University of British Columbia, Vancouver, Canada; Department of Medicine, Division of Physical Medicine and Rehabilitation, University of British Columbia, Vancouver, Canada
| | - Arshdeep S Marwaha
- International Collaboration on Repair Discoveries (ICORD), University of British Columbia, Vancouver, Canada; Department of Medicine, Division of Physical Medicine and Rehabilitation, University of British Columbia, Vancouver, Canada
| | - Andrei V Krassioukov
- International Collaboration on Repair Discoveries (ICORD), University of British Columbia, Vancouver, Canada; Department of Medicine, Division of Physical Medicine and Rehabilitation, University of British Columbia, Vancouver, Canada; GF Strong Rehabilitation Center, Vancouver Coastal Health, Vancouver, Canada.
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