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Kreifels P, Bodi I, Hornyik T, Franke G, Perez-Feliz S, Lewetag R, Moss R, Castiglione A, Ziupa D, Zehender M, Brunner M, Bode C, Odening KE. Oxytocin exerts harmful cardiac repolarization prolonging effects in drug-induced LQTS. IJC Heart & Vasculature 2022; 40:101001. [PMID: 35391783 PMCID: PMC8980310 DOI: 10.1016/j.ijcha.2022.101001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2022] [Revised: 03/07/2022] [Accepted: 03/08/2022] [Indexed: 11/25/2022]
Abstract
Background Oxytocin is used therapeutically in psychiatric patients. Many of these also receive anti-depressant or anti-psychotic drugs causing acquired long-QT-syndrome (LQTS) by blocking HERG/IKr. We previously identified an oxytocin-induced QT-prolongation in LQT2 rabbits, indicating potential harmful effects of combined therapy. We thus aimed to analyze the effects of dual therapy with oxytocin and fluoxetine/risperidone on cardiac repolarization. Methods Effects of risperidone, fluoxetine and oxytocin on QT/QTc, short-term variability (STV) of QT, and APD were assessed in rabbits using in vivo ECG and ex vivo monophasic AP recordings in Langendorff-perfused hearts. Underlying mechanisms were assessed using patch clamp in isolated cardiomyocytes. Results Oxytocin, fluoxetine and risperidone prolonged QTc and APD in whole hearts. The combination of fluoxetine + oxytocin resulted in further QTc- and APD-prolongation, risperidone + oxytocin tended to increase QTc and APD compared to monotherapy. Temporal QT instability, STVQTc was increased by oxytocin, fluoxetine / fluoxetine + oxytocin and risperidone / risperidone + oxytocin. Similar APD-prolonging effects were confirmed in isolated cardiomyocytes due to differential effects of the compounds on repolarizing ion currents: Oxytocin reduced IKs, fluoxetine and risperidone reduced IKr, resulting in additive effects on IKtotal-tail. In addition, oxytocin reduced IK1, further reducing the repolarization reserve. Conclusion Oxytocin, risperidone and fluoxetine prolong QTc / APD. Combined treatment further prolongs QTc/APD due to differential effects on IKs and IK1 (block by oxytocin) and IKr (block by risperidone and fluoxetine), leading to pronounced impairment of repolarization reserve. Oxytocin should be used with caution in patients in the context of acquired LQTS.
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Hornyik T, Bodi I, Michaelides K, Mettke L, Perez-Feliz S, El-Battrawy I, Brunner M, Bode C, Odening K. Metabolic treatment of an electrical disease? Beneficial APD/QT prolongation by L-Carnitine in transgenic SQT1 rabbit models. Eur Heart J 2021. [DOI: 10.1093/eurheartj/ehab724.3212] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Abstract
Background
Short-QT syndrome 1 (SQT1) is a genetic cardiac channelopathy caused by gain-of-function mutations (KCNH2-N588K) in HERG/IKr, that leads to shortened QT-interval, increased risk for arrhythmias and sudden cardiac death (SCD). An acquired form of SQTS has been described in patients with primary (genetic) carnitine-deficiency, indicating that carnitine might affect cardiac repolarization.
Purpose
We aimed to investigate potential beneficial (APD/QT-prolonging) effect of L-Carnitine in (genetic) SQTS using transgenic SQT1 rabbits that mimic the human disease phenotype.
Methods
Effects of L-carnitine on cardiac repolarisation were assessed in adult wildtype (WT) and transgenic SQT1 rabbits (KCNH2-N588K) using in vivo ECG and ex vivo Langendorff-perfused whole-heart or isolated ventricular cardiomyocyte action potential (AP) recordings. Effects on ion currents were assessed by whole-cell patch-clamping.
Results
In vivo, the heart-rate corrected QT index (QTi) was prolonged significantly by L-carnitine both in WT (QTi, baseline 102.7%±4.9 vs. L-carnitine 106.9%±6.2, p<0.05, n=12) and SQT1 (QTi, baseline 94.8%±7.4 vs. L-carnitine 99.5%±8.2, p<0.05, n=13), leading to normalisation of QTi in SQT1. Ex vivo, whole-heart monophasic and cellular APs were also significantly prolonged by L-carnitine in WT and SQT1 (change in monophasic APD75, ms, WT +13.9±4.4, SQT1 +9.9±7.0; change in cellular APD90, %, WT +10.4%, SQT1 +10.4%, all p<0.05). As underlying mechanisms, we identified acute effects on the main repolarizing ion currents IKr and IKs: IKr-steady, which is significantly increased in SQT1 contributing to accelerated repolarization, was reduced by L-carnitine (WT: −23%, SQT1: −16%). Moreover, L-carnitine accelerated the deactivation kinetics of IKr - while no change was observed in IKr-tail. In addition, IKs-steady was decreased by L-carnitine in SQT1 and WT cardiomyocytes.
Conclusion
L-carnitine prolongs/normalizes QT and APD in transgenic SQT1 rabbits by decreasing the pathologically increased IKr-steady and also IKs-steady and may therefore serve as potential future anti-arrhythmic therapy in SQTS.
Funding Acknowledgement
Type of funding sources: Public grant(s) – National budget only. Main funding source(s): German Research Foundation (DFG)
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Affiliation(s)
- T Hornyik
- University of Bern, Translational Cardiology, Department of Cardiology and Department of Physiology, Bern, Switzerland
| | - I Bodi
- University of Bern, Translational Cardiology, Department of Cardiology and Department of Physiology, Bern, Switzerland
| | - K Michaelides
- Heart Center University of Freiburg, Department of Cardiology and Angiology I, Freiburg, Germany
| | - L Mettke
- Heart Center University of Freiburg, Department of Cardiology and Angiology I, Freiburg, Germany
| | - S Perez-Feliz
- Heart Center University of Freiburg, Department of Cardiology and Angiology I, Freiburg, Germany
| | - I El-Battrawy
- University Medical Centre of Mannheim, First Department of Medicine, Mannheim, Germany
| | - M Brunner
- Heart Center University of Freiburg, Department of Cardiology and Angiology I, Freiburg, Germany
| | - C Bode
- Heart Center University of Freiburg, Department of Cardiology and Angiology I, Freiburg, Germany
| | - K Odening
- University of Bern, Translational Cardiology, Department of Cardiology and Department of Physiology, Bern, Switzerland
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3
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Odening KE, Bodi I, Franke G, Rieke R, Ryan de Medeiros A, Perez-Feliz S, Fürniss H, Mettke L, Michaelides K, Lang CN, Steinfurt J, Pantulu ND, Ziupa D, Menza M, Zehender M, Bugger H, Peyronnet R, Behrends JC, Doleschall Z, Zur Hausen A, Bode C, Jolivet G, Brunner M. Transgenic short-QT syndrome 1 rabbits mimic the human disease phenotype with QT/action potential duration shortening in the atria and ventricles and increased ventricular tachycardia/ventricular fibrillation inducibility. Eur Heart J 2020; 40:842-853. [PMID: 30496390 DOI: 10.1093/eurheartj/ehy761] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/19/2017] [Revised: 05/07/2018] [Accepted: 10/29/2018] [Indexed: 11/14/2022] Open
Abstract
AIMS Short-QT syndrome 1 (SQT1) is an inherited channelopathy with accelerated repolarization due to gain-of-function in HERG/IKr. Patients develop atrial fibrillation, ventricular tachycardia (VT), and sudden cardiac death with pronounced inter-individual variability in phenotype. We generated and characterized transgenic SQT1 rabbits and investigated electrical remodelling. METHODS AND RESULTS Transgenic rabbits were generated by oocyte-microinjection of β-myosin-heavy-chain-promoter-KCNH2/HERG-N588K constructs. Short-QT syndrome 1 and wild type (WT) littermates were subjected to in vivo ECG, electrophysiological studies, magnetic resonance imaging, and ex vivo action potential (AP) measurements. Electrical remodelling was assessed using patch clamp, real-time PCR, and western blot. We generated three SQT1 founders. QT interval was shorter and QT/RR slope was shallower in SQT1 than in WT (QT, 147.8 ± 2 ms vs. 166.4 ± 3, P < 0.0001). Atrial and ventricular refractoriness and AP duration were shortened in SQT1 (vAPD90, 118.6 ± 5 ms vs. 154.4 ± 2, P < 0.0001). Ventricular tachycardia/fibrillation (VT/VF) inducibility was increased in SQT1. Systolic function was unaltered but diastolic relaxation was enhanced in SQT1. IKr-steady was increased with impaired inactivation in SQT1, while IKr-tail was reduced. Quinidine prolonged/normalized QT and action potential duration (APD) in SQT1 rabbits by reducing IKr. Diverse electrical remodelling was observed: in SQT1, IK1 was decreased-partially reversing the phenotype-while a small increase in IKs may partly contribute to an accentuation of the phenotype. CONCLUSION Short-QT syndrome 1 rabbits mimic the human disease phenotype on all levels with shortened QT/APD and increased VT/VF-inducibility and show similar beneficial responses to quinidine, indicating their value for elucidation of arrhythmogenic mechanisms and identification of novel anti-arrhythmic strategies.
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Affiliation(s)
- Katja E Odening
- Department of Cardiology and Angiology I, Heart Center University of Freiburg, Hugstetter Str. 55, Freiburg, Germany.,Faculty of Medicine, University of Freiburg, Breisacher Str. 153, Freiburg, Germany
| | - Ilona Bodi
- Department of Cardiology and Angiology I, Heart Center University of Freiburg, Hugstetter Str. 55, Freiburg, Germany.,Faculty of Medicine, University of Freiburg, Breisacher Str. 153, Freiburg, Germany
| | - Gerlind Franke
- Department of Cardiology and Angiology I, Heart Center University of Freiburg, Hugstetter Str. 55, Freiburg, Germany.,Faculty of Medicine, University of Freiburg, Breisacher Str. 153, Freiburg, Germany
| | - Raphaela Rieke
- Department of Cardiology and Angiology I, Heart Center University of Freiburg, Hugstetter Str. 55, Freiburg, Germany.,Faculty of Medicine, University of Freiburg, Breisacher Str. 153, Freiburg, Germany
| | - Anna Ryan de Medeiros
- Department of Cardiology and Angiology I, Heart Center University of Freiburg, Hugstetter Str. 55, Freiburg, Germany.,Faculty of Medicine, University of Freiburg, Breisacher Str. 153, Freiburg, Germany
| | - Stefanie Perez-Feliz
- Department of Cardiology and Angiology I, Heart Center University of Freiburg, Hugstetter Str. 55, Freiburg, Germany.,Faculty of Medicine, University of Freiburg, Breisacher Str. 153, Freiburg, Germany
| | - Hannah Fürniss
- Faculty of Medicine, University of Freiburg, Breisacher Str. 153, Freiburg, Germany.,Institute for Experimental Cardiovascular Medicine, Heart Center University of Freiburg, Elsässer Str. 2Q, Freiburg, Germany.,Department of Congenital Heart Disease and Pediatric Cardiology, Heart Center University of Freiburg, Mathildenstr. 1, Freiburg, Germany
| | - Lea Mettke
- Department of Cardiology and Angiology I, Heart Center University of Freiburg, Hugstetter Str. 55, Freiburg, Germany.,Faculty of Medicine, University of Freiburg, Breisacher Str. 153, Freiburg, Germany
| | - Konstantin Michaelides
- Department of Cardiology and Angiology I, Heart Center University of Freiburg, Hugstetter Str. 55, Freiburg, Germany.,Faculty of Medicine, University of Freiburg, Breisacher Str. 153, Freiburg, Germany
| | - Corinna N Lang
- Department of Cardiology and Angiology I, Heart Center University of Freiburg, Hugstetter Str. 55, Freiburg, Germany.,Faculty of Medicine, University of Freiburg, Breisacher Str. 153, Freiburg, Germany
| | - Johannes Steinfurt
- Department of Cardiology and Angiology I, Heart Center University of Freiburg, Hugstetter Str. 55, Freiburg, Germany.,Faculty of Medicine, University of Freiburg, Breisacher Str. 153, Freiburg, Germany
| | - Naga Deepa Pantulu
- Department of Cardiology and Angiology I, Heart Center University of Freiburg, Hugstetter Str. 55, Freiburg, Germany.,Department of Pathology, University Hospital Freiburg, Breisacher Str. 115A, Freiburg, Germany.,Department of Pathology, Maastricht University Medical Center, AZ Maastricht, Netherlands
| | - David Ziupa
- Department of Cardiology and Angiology I, Heart Center University of Freiburg, Hugstetter Str. 55, Freiburg, Germany.,Faculty of Medicine, University of Freiburg, Breisacher Str. 153, Freiburg, Germany
| | - Marius Menza
- Faculty of Medicine, University of Freiburg, Breisacher Str. 153, Freiburg, Germany.,Department of Radiology and Medical Physics, Medical Center University of Freiburg, Killianstraße 5a, Freiburg, Germany
| | - Manfred Zehender
- Department of Cardiology and Angiology I, Heart Center University of Freiburg, Hugstetter Str. 55, Freiburg, Germany.,Faculty of Medicine, University of Freiburg, Breisacher Str. 153, Freiburg, Germany
| | - Heiko Bugger
- Department of Cardiology and Angiology I, Heart Center University of Freiburg, Hugstetter Str. 55, Freiburg, Germany.,Faculty of Medicine, University of Freiburg, Breisacher Str. 153, Freiburg, Germany
| | - Remi Peyronnet
- Faculty of Medicine, University of Freiburg, Breisacher Str. 153, Freiburg, Germany.,Institute for Experimental Cardiovascular Medicine, Heart Center University of Freiburg, Elsässer Str. 2Q, Freiburg, Germany
| | - Jan C Behrends
- Faculty of Medicine, University of Freiburg, Breisacher Str. 153, Freiburg, Germany.,Department of Physiology, University of Freiburg, Hermann-Herder Straße 7, Freiburg, Germany
| | - Zoltan Doleschall
- Department of Pathogenetics, National Institute of Oncology, 7-9 Ráth György str, H-1122 Budapest, Hungary
| | - Axel Zur Hausen
- Department of Pathology, University Hospital Freiburg, Breisacher Str. 115A, Freiburg, Germany.,Department of Pathology, Maastricht University Medical Center, AZ Maastricht, Netherlands
| | - Christoph Bode
- Department of Cardiology and Angiology I, Heart Center University of Freiburg, Hugstetter Str. 55, Freiburg, Germany.,Faculty of Medicine, University of Freiburg, Breisacher Str. 153, Freiburg, Germany
| | - Genevieve Jolivet
- INRA, UMR1198 Biologie du Développement et Reproduction, Allée de Vilvert, Jouy-en-Josas, France
| | - Michael Brunner
- Department of Cardiology and Angiology I, Heart Center University of Freiburg, Hugstetter Str. 55, Freiburg, Germany.,Faculty of Medicine, University of Freiburg, Breisacher Str. 153, Freiburg, Germany.,Department of Cardiology and Medical Intensive Care, St. Josefskrankenhaus, Sautierstraße 1, Freiburg, Germany
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4
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Sarkozy A, Fernandez-Garcia M, Manzur A, Mein R, Bodi I, Phadke R, Wraige E, Deshpande C, Holder S, Hurst J, Gautel M, Jungbluth H, Muntoni F. P.109Congenital myopathy in patients with Kabuki and Au-Kline syndromes - Double trouble or expansion of the phenotypes? Neuromuscul Disord 2019. [DOI: 10.1016/j.nmd.2019.06.165] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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5
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Phadke R, Sarkozy A, Oates E, Mein R, Bodi I, Feng L, Manzur A, Thomas N, Illingworth M, Mazanti I, Ellard S, Sewry C, Gautel M, Jungbluth H, Muntoni F. P.236Myofibres with subsarcolemmal rims and/or central aggregates of mitochondria (SRCAM) are prevalent in congenital titinopathies. Neuromuscul Disord 2019. [DOI: 10.1016/j.nmd.2019.06.350] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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6
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Kirby AJ, Lavrador JP, Brogna C, Vergani F, Chandler C, Zebian B, Bodi I, Bhangoo R, Ashkan K, Finnerty GT. P11.49 An electrophysiological signature of glioma infiltration in the ex vivo human brain. Neuro Oncol 2019. [DOI: 10.1093/neuonc/noz126.195] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Abstract
BACKGROUND
Invading glioma cells affect the physiological function of the peritumoural cortex. This may manifest clinically as seizures. Here, we investigate the effect the invading glioma cells on the electrophysiological signalling of the peritumoral cortex using living human brain tissue donated by people having a craniotomy for glioma resection (REC approval, 18/SW/002).
MATERIAL AND METHODS
The brain tissue was cut into thin slices, which preserved the architecture of the glioma and the adjacent healthy brain. The brain slices were incubated in 5-aminolevulinic acid to make the glioma cells fluorescent. We observed 5-ALA induced fluorescence in both low-grade and high-grade gliomas. This enabled us to make electrophysiological recordings of brain activity across the boundary between glioma and brain.
RESULTS
We recorded from brain slices of 5 participants with glioblastoma and 4 participants with oligodendroglioma (WHO grade II - III). Spontaneous “seizure-like” discharges were recorded in brain slices from 5/8 participants (3 GBM, 2 oligodendroglioma) who reported seizures and from one participant (GBM) who had not had any clinical seizures. Further analysis of the electrical discharges revealed that they could be subdivided into two distinct types based on the major frequencies in the discharge.
CONCLUSION
We concluded that human brain slices from people with either a low-grade or a high-grade glioma can generate spontaneous seizure-like discharges. This electrophysiological signature will be compared to infiltration and grade of the glioma cells in the donated sample. The living human brain tissue preparation gives us a platform to study the mechanisms of tumour-associated seizures and how abnormal neural activity affects glioma growth.
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Affiliation(s)
- A J Kirby
- Department of Basic and Clinical Neuroscience, Kings College London, London, United Kingdom
| | - J P Lavrador
- Department of Neurosurgery, King’s College Hospital, London, United Kingdom
| | - C Brogna
- Department of Neurosurgery, King’s College Hospital, London, United Kingdom
- Department of Basic and Clinical Neuroscience, Kings College London, London, United Kingdom
| | - F Vergani
- Department of Neurosurgery, King’s College Hospital, London, United Kingdom
| | - C Chandler
- Department of Neurosurgery, King’s College Hospital, London, United Kingdom
| | - B Zebian
- Department of Neurosurgery, King’s College Hospital, London, United Kingdom
| | - I Bodi
- Department of Clinical Neuropathology, King’s College Hospital, London, United Kingdom
- Department of Basic and Clinical Neuroscience, Kings College London, London, United Kingdom
| | - R Bhangoo
- Department of Neurosurgery, King’s College Hospital, London, United Kingdom
| | - K Ashkan
- Department of Neurosurgery, King’s College Hospital, London, United Kingdom
- Department of Basic and Clinical Neuroscience, Kings College London, London, United Kingdom
| | - G T Finnerty
- Department of Basic and Clinical Neuroscience, Kings College London, London, United Kingdom
- Department of Neurology, King’s College Hospital, London, United Kingdom
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7
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Bodi I, Wuelfers EM, Castiglione A, Perez-Feliz S, Zehender M, Brunner M, Bode C, Seemann G, Odening KE. Comment: postpartum hormones oxytocin and prolactin cause pro-arrhythmic prolongation of cardiac repolarization in long QT syndrome type 2—Authors’ reply. Europace 2019; 21:1141-1142. [DOI: 10.1093/europace/euz182] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- Ilona Bodi
- Department of Cardiology and Angiology I, Heart Center University of Freiburg, Hugstetter Str. 55, Freiburg, Germany
- Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Institute of Experimental Cardiovascular Medicine, Heart Center University of Freiburg, Freiburg, Germany
| | - Eike M Wuelfers
- Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Institute of Experimental Cardiovascular Medicine, Heart Center University of Freiburg, Freiburg, Germany
| | - Alessandro Castiglione
- Department of Cardiology and Angiology I, Heart Center University of Freiburg, Hugstetter Str. 55, Freiburg, Germany
- Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Institute of Experimental Cardiovascular Medicine, Heart Center University of Freiburg, Freiburg, Germany
| | - Stefanie Perez-Feliz
- Department of Cardiology and Angiology I, Heart Center University of Freiburg, Hugstetter Str. 55, Freiburg, Germany
- Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Institute of Experimental Cardiovascular Medicine, Heart Center University of Freiburg, Freiburg, Germany
| | - Manfred Zehender
- Department of Cardiology and Angiology I, Heart Center University of Freiburg, Hugstetter Str. 55, Freiburg, Germany
- Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Michael Brunner
- Department of Cardiology and Angiology I, Heart Center University of Freiburg, Hugstetter Str. 55, Freiburg, Germany
- Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Department of Cardiology and Medical Intensive Care, St. Josefskrankenhaus, Freiburg, Germany
| | - Christoph Bode
- Department of Cardiology and Angiology I, Heart Center University of Freiburg, Hugstetter Str. 55, Freiburg, Germany
- Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Gunnar Seemann
- Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Institute of Experimental Cardiovascular Medicine, Heart Center University of Freiburg, Freiburg, Germany
| | - Katja E Odening
- Department of Cardiology and Angiology I, Heart Center University of Freiburg, Hugstetter Str. 55, Freiburg, Germany
- Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Institute of Experimental Cardiovascular Medicine, Heart Center University of Freiburg, Freiburg, Germany
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8
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Burford C, Laxton R, Sidhu Z, Aizpurua M, King A, Bodi I, Ashkan K, Al-Sarraj S. ATRX immunohistochemistry can help refine 'not elsewhere classified' categorisation for grade II/III gliomas. Br J Neurosurg 2019; 33:536-540. [PMID: 31018710 DOI: 10.1080/02688697.2019.1600657] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Purpose: The 2016 WHO tumour classification highlights the role of IDH1/2 gene mutation and 1p/19q co-deletion in classifying grade II/III gliomas. A recent cIMPACT-NOW update proposes the use of the term 'Not Elsewhere Classified' (NEC) for IDH-mutant, non co-deleted tumours. Here we show how the incorporation of ATRX immunohistochemistry can be used to better delineate the NEC group. Methods: Clinical data was collected for 112 patients (59% male) treated at our unit. Mutations in IDH1/2 genes were detected by pyrosequencing or immunohistochemistry, 1p/19q co-deletion was assessed with fluorescence in situ hybridisation and ATRX status was determined using immunohistochemical techniques. Tumours were grouped on the basis of molecular markers and outcomes compared. Results: The mean age of diagnosis was 42.6 years (20-73 years). There were 88 oligodendrogliomas (II = 47, III = 41), 18 diffuse astrocytomas (II = 9, III = 9) and 6 oligoastrocytomas (II = 4, III = 2). The majority of gliomas (87.5%) had mutations in IDH1/2. 1p/19q co-deletion was significantly associated with oligodendroglial morphology (p = < 0.001) and was mutually exclusive with ATRX mutation. Classification on the basis of molecular information showed a significant different in survival between the groups. Conclusions: ATRX immunohistochemisty is a useful adjunct which can be used with IDH mutation status, 1p/19q co-deletion and histological findings to further define tumour groups. More work is needed to understand the molecular profiles and prognostic implications for non co-deletion, ATRX preserved cases.
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Affiliation(s)
- C Burford
- Institute of Psychiatry, Psychology & Neuroscience (IoPPN), King's College London , London , UK
| | - R Laxton
- Department of Neuropathology, King's College Hospital , London , UK
| | - Z Sidhu
- Institute of Psychiatry, Psychology & Neuroscience (IoPPN), King's College London , London , UK
| | - M Aizpurua
- Department of Neuropathology, King's College Hospital , London , UK
| | - A King
- Department of Neuropathology, King's College Hospital , London , UK
| | - I Bodi
- Department of Neuropathology, King's College Hospital , London , UK
| | - K Ashkan
- Department of Neurosurgery, King's College Hospital , London , UK
| | - S Al-Sarraj
- Department of Neuropathology, King's College Hospital , London , UK
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9
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Bodi I, Sorge J, Castiglione A, Glatz SM, Wuelfers EM, Franke G, Perez-Feliz S, Koren G, Zehender M, Bugger H, Seemann G, Brunner M, Bode C, Odening KE. Postpartum hormones oxytocin and prolactin cause pro-arrhythmic prolongation of cardiac repolarization in long QT syndrome type 2. Europace 2019; 21:1126-1138. [DOI: 10.1093/europace/euz037] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2018] [Accepted: 02/21/2019] [Indexed: 12/16/2022] Open
Abstract
Aims
Women with long QT syndrome 2 (LQT2) have a particularly high postpartal risk for lethal arrhythmias. We aimed at investigating whether oxytocin and prolactin contribute to this risk by affecting repolarization.
Methods and results
In female transgenic LQT2 rabbits (HERG-G628S, loss of IKr), hormone effects on QT/action potential duration (APD) were assessed (0.2–200 ng/L). Hormone effects (200 ng/L) on ion currents and cellular APD were determined in transfected cells and LQT2 cardiomyocytes. Hormone effects on ion channels were assessed with qPCR and western blot. Experimental data were incorporated into in silico models to determine the pro-arrhythmic potential. Oxytocin prolonged QTc and steepened QT/RR-slope in vivo and prolonged ex vivo APD75 in LQT2 hearts. Prolactin prolonged APD75 at high concentrations. As underlying mechanisms, we identified an oxytocin- and prolactin-induced acute reduction of IKs-tail and IKs-steady (−25.5%, oxytocin; −13.3%, prolactin, P < 0.05) in CHO-cells and LQT2-cardiomyocytes. IKr currents were not altered. This oxytocin-/prolactin-induced IKs reduction caused APD90 prolongation (+11.9%/+13%, P < 0.05) in the context of reduced/absent IKr in LQT2 cardiomyocytes. Hormones had no effect on IK1 and ICa,L in cardiomyocytes. Protein and mRNA levels of CACNA1C/Cav1.2 and RyR2 were enhanced by oxytocin and prolactin. Incorporating these hormone effects into computational models resulted in reduced repolarization reserve and increased propensity to pro-arrhythmic permanent depolarization, lack of capture and early afterdepolarizations formation.
Conclusions
Postpartum hormones oxytocin and prolactin prolong QT/APD in LQT2 by reducing IKs and by increasing Cav1.2 and RyR2 expression/transcription, thereby contributing to the increased postpartal arrhythmic risk in LQT2.
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Affiliation(s)
- Ilona Bodi
- Department of Cardiology and Angiology I, Heart Center University of Freiburg, Hugstetter Str. 55, Freiburg, Germany
- Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Institute for Experimental Cardiovascular Medicine, University Heart Center Freiburg - Bad Krozingen and Medical Center – University of Freiburg, Freiburg, Germany
| | - Jonathan Sorge
- Department of Cardiology and Angiology I, Heart Center University of Freiburg, Hugstetter Str. 55, Freiburg, Germany
- Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Alessandro Castiglione
- Department of Cardiology and Angiology I, Heart Center University of Freiburg, Hugstetter Str. 55, Freiburg, Germany
- Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Institute for Experimental Cardiovascular Medicine, University Heart Center Freiburg - Bad Krozingen and Medical Center – University of Freiburg, Freiburg, Germany
| | - Sylva M Glatz
- Department of Cardiology and Angiology I, Heart Center University of Freiburg, Hugstetter Str. 55, Freiburg, Germany
- Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Eike M Wuelfers
- Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Institute for Experimental Cardiovascular Medicine, University Heart Center Freiburg - Bad Krozingen and Medical Center – University of Freiburg, Freiburg, Germany
| | - Gerlind Franke
- Department of Cardiology and Angiology I, Heart Center University of Freiburg, Hugstetter Str. 55, Freiburg, Germany
- Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Stefanie Perez-Feliz
- Department of Cardiology and Angiology I, Heart Center University of Freiburg, Hugstetter Str. 55, Freiburg, Germany
- Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Institute for Experimental Cardiovascular Medicine, University Heart Center Freiburg - Bad Krozingen and Medical Center – University of Freiburg, Freiburg, Germany
| | - Gideon Koren
- Division of Cardiology, Cardiovascular Research Center, Rhode Island Hospital, Alpert Medical School of Brown University, Providence, RI, USA
| | - Manfred Zehender
- Department of Cardiology and Angiology I, Heart Center University of Freiburg, Hugstetter Str. 55, Freiburg, Germany
- Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Heiko Bugger
- Department of Cardiology and Angiology I, Heart Center University of Freiburg, Hugstetter Str. 55, Freiburg, Germany
- Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Gunnar Seemann
- Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Institute for Experimental Cardiovascular Medicine, University Heart Center Freiburg - Bad Krozingen and Medical Center – University of Freiburg, Freiburg, Germany
| | - Michael Brunner
- Department of Cardiology and Angiology I, Heart Center University of Freiburg, Hugstetter Str. 55, Freiburg, Germany
- Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Department of Cardiology and Medical Intensive Care, St. Josefskrankenhaus, Freiburg, Germany
| | - Christoph Bode
- Department of Cardiology and Angiology I, Heart Center University of Freiburg, Hugstetter Str. 55, Freiburg, Germany
- Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Katja E Odening
- Department of Cardiology and Angiology I, Heart Center University of Freiburg, Hugstetter Str. 55, Freiburg, Germany
- Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Institute for Experimental Cardiovascular Medicine, University Heart Center Freiburg - Bad Krozingen and Medical Center – University of Freiburg, Freiburg, Germany
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Sooltangos A, Giamouriadis A, Barazi S, Barkas K, Thomas N, Bodi I, Ghimire P, Maratos E. P37 Do all notochordal lesions require proton beam radiotherapy? A case series of ecchordosis physaliphora. J Neurol Neurosurg Psychiatry 2019. [DOI: 10.1136/jnnp-2019-abn.109] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
ObjectivesEcchordosis physaliphora (EP) is a benign, usually asymptomatic, notochord tumour but may also present with a spontaneous CSF fistula. Differentiating EP from its more aggressive counterpart, chordoma is challenging but important as the clinical course and management differ significantly, with the latter requiring proton beam radiotherapy. This case series aims to further inform this discussion.DesignCase series.SubjectsPatients with suspected EP from 2015–2018.MethodsRetrospective analysis.ResultsSix patients were identified. Four presented with suspected CSF leak. MRI revealed a T1-hypointense and T2-hyperintense clival lesion without enhancement. CT showed pneumocephalus, a clival defect and no mass lesion. All underwent endoscopic endonasal repair of CSF fistula with biopsy. Histology revealed physaliphorous cells with no mitoses; immunohistochemistry confirmed notochord origin (EMA, S100, CD10 and/or MNF116) and low proliferation index. In 2 patients, EP was found incidentally on imaging and these lesions have remained static on follow-up.ConclusionsIn the absence of a clival mass, notochord remnant lesions with benign histopathology can be treated as EP and patients can avoid radiotherapy. The diagnosis of EP, however, remains challenging as no distinctive histopathological marker exists to differentiate it from chordoma and until a genetic or immunohistochemical marker is identified, the diagnosis rests solely on the presence or absence of a mass on imaging.
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11
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Knuiman GJ, Küsters B, Eshuis L, Snoeck M, Lammens M, Heytens L, De Ridder W, Baets J, Scalco RS, Quinlivan R, Holton J, Bodi I, Wraige E, Radunovic A, von Landenberg C, Reimann J, Kamsteeg EJ, Sewry C, Jungbluth H, Voermans NC. The histopathological spectrum of malignant hyperthermia and rhabdomyolysis due to RYR1 mutations. J Neurol 2019; 266:876-887. [PMID: 30788618 PMCID: PMC6420893 DOI: 10.1007/s00415-019-09209-z] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2018] [Revised: 01/16/2019] [Accepted: 01/19/2019] [Indexed: 12/22/2022]
Abstract
Objective The histopathological features of malignant hyperthermia (MH) and non-anaesthetic (mostly exertional) rhabdomyolysis (RM) due to RYR1 mutations have only been reported in a few cases. Methods We performed a retrospective multi-centre cohort study focussing on the histopathological features of patients with MH or RM due to RYR1 mutations (1987–2017). All muscle biopsies were reviewed by a neuromuscular pathologist. Additional morphometric and electron microscopic analysis were performed where possible. Results Through the six participating centres we identified 50 patients from 46 families, including patients with MH (n = 31) and RM (n = 19). Overall, the biopsy of 90% of patients showed one or more myopathic features including: increased fibre size variability (n = 44), increase in the number of fibres with internal nuclei (n = 30), and type I fibre predominance (n = 13). Abnormalities on oxidative staining, generally considered to be more specifically associated with RYR1-related congenital myopathies, were observed in 52%, and included unevenness (n = 24), central cores (n = 7) and multi-minicores (n = 3). Apart from oxidative staining abnormalities more frequently observed in MH patients, the histopathological spectrum was similar between the two groups. There was no correlation between the presence of cores and the occurrence of clinically detectable weakness or presence of (likely) pathogenic variants. Conclusions Patients with RYR1-related MH and RM exhibit a similar histopathological spectrum, ranging from mild myopathic changes to cores and other features typical of RYR1-related congenital myopathies. Suggestive histopathological features may support RYR1 involvement, also in cases where the in vitro contracture test is not informative. Electronic supplementary material The online version of this article (10.1007/s00415-019-09209-z) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- G J Knuiman
- Department of Pathology, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - B Küsters
- Department of Pathology, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - L Eshuis
- Department of Pathology, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - M Snoeck
- National MH Investigation Unit, Department of Anaesthesiology, Canisius Wilhelmina Hospital, Nijmegen, The Netherlands
| | - M Lammens
- Department of Pathology, Antwerp University Hospital, University of Antwerp, Edegem, Belgium
| | - L Heytens
- Malignant Hyperthermia Research Unit, University of Antwerp, Antwerp, Belgium
| | - W De Ridder
- Neurogenetics Group, Center for Molecular Neurology, VIB, Antwerp, Belgium
- Laboratory of Neuromuscular Pathology, Institute Born-Bunge, University of Antwerp, Antwerp, Belgium
- Department of Neurology, Neuromuscular Reference Centre, Antwerp University Hospital, Antwerp, Belgium
| | - J Baets
- Neurogenetics Group, Center for Molecular Neurology, VIB, Antwerp, Belgium
- Laboratory of Neuromuscular Pathology, Institute Born-Bunge, University of Antwerp, Antwerp, Belgium
- Department of Neurology, Neuromuscular Reference Centre, Antwerp University Hospital, Antwerp, Belgium
| | - R S Scalco
- MRC Centre for Neuromuscular Diseases, Institute of Neurology, University College London, London, UK
| | - R Quinlivan
- MRC Centre for Neuromuscular Diseases, Institute of Neurology, University College London, London, UK
| | - J Holton
- MRC Centre for Neuromuscular Diseases, Institute of Neurology, University College London, London, UK
| | - I Bodi
- Department of Paediatric Neurology, Neuromuscular Service, Evelina Children's Hospital, Guy's and St Thomas' Hospital NHS Foundation Trust, London, UK
| | - E Wraige
- Department of Paediatric Neurology, Neuromuscular Service, Evelina Children's Hospital, Guy's and St Thomas' Hospital NHS Foundation Trust, London, UK
| | - A Radunovic
- Barts Neuromuscular Diseases Centre, Royal London Hospital, London, UK
| | - C von Landenberg
- Muscle Lab, Department of Neurology, University of Bonn Medical Centre, Bonn, Germany
| | - J Reimann
- Muscle Lab, Department of Neurology, University of Bonn Medical Centre, Bonn, Germany
| | - E-J Kamsteeg
- Department of Human Genetics, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - C Sewry
- Dubowitz Neuromuscular Centre, UCL Institute of Child Health and Great Ormond Street Hospital for Children, London, UK
| | - H Jungbluth
- Department of Paediatric Neurology, Neuromuscular Service, Evelina Children's Hospital, Guy's and St Thomas' Hospital NHS Foundation Trust, London, UK
- Muscle Signalling Section, Randall Division for Cell and Molecular Biophysics, King's College, London, UK
- Department of Basic and Clinical Neuroscience, King's College, IoPPN, London, UK
| | - N C Voermans
- Department of Neurology, Radboud University Medical Centre, Nijmegen, The Netherlands.
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Kreifels P, Franke G, Perez-Feliz S, Bodi I, Castiglione A, Ziupa D, Bode C, Odening KE. 5922Oxytocin has harmful cardiac repolarization prolonging effects - Particularly in context of drug-induced LQTS. Eur Heart J 2018. [DOI: 10.1093/eurheartj/ehy566.5922] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- P Kreifels
- University of Freiburg, University Heart Center Freiburg, Department of Cardiology and Angiology I, Freiburg, Germany
| | - G Franke
- University of Freiburg, University Heart Center Freiburg, Department of Cardiology and Angiology I, Freiburg, Germany
| | - S Perez-Feliz
- University of Freiburg, University Heart Center Freiburg, Department of Cardiology and Angiology I, Freiburg, Germany
| | - I Bodi
- University of Freiburg, University Heart Center Freiburg, Department of Cardiology and Angiology I, Freiburg, Germany
| | - A Castiglione
- University of Freiburg, University Heart Center Freiburg, Department of Cardiology and Angiology I, Freiburg, Germany
| | - D Ziupa
- University of Freiburg, University Heart Center Freiburg, Department of Cardiology and Angiology I, Freiburg, Germany
| | - C Bode
- University of Freiburg, University Heart Center Freiburg, Department of Cardiology and Angiology I, Freiburg, Germany
| | - K E Odening
- University of Freiburg, University Heart Center Freiburg, Department of Cardiology and Angiology I, Freiburg, Germany
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Burton RAB, Rog-Zielinska EA, Corbett AD, Peyronnet R, Bodi I, Fink M, Sheldon J, Hoenger A, Calaghan SC, Bub G, Kohl P. Caveolae in Rabbit Ventricular Myocytes: Distribution and Dynamic Diminution after Cell Isolation. Biophys J 2017; 113:1047-1059. [PMID: 28877488 PMCID: PMC5653872 DOI: 10.1016/j.bpj.2017.07.026] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2016] [Revised: 05/16/2017] [Accepted: 07/06/2017] [Indexed: 12/12/2022] Open
Abstract
Caveolae are signal transduction centers, yet their subcellular distribution and preservation in cardiac myocytes after cell isolation are not well documented. Here, we quantify caveolae located within 100 nm of the outer cell surface membrane in rabbit single-ventricular cardiomyocytes over 8 h post-isolation and relate this to the presence of caveolae in intact tissue. Hearts from New Zealand white rabbits were either chemically fixed by coronary perfusion or enzymatically digested to isolate ventricular myocytes, which were subsequently fixed at 0, 3, and 8 h post-isolation. In live cells, the patch-clamp technique was used to measure whole-cell plasma membrane capacitance, and in fixed cells, caveolae were quantified by transmission electron microscopy. Changes in cell-surface topology were assessed using scanning electron microscopy. In fixed ventricular myocardium, dual-axis electron tomography was used for three-dimensional reconstruction and analysis of caveolae in situ. The presence and distribution of surface-sarcolemmal caveolae in freshly isolated cells matches that of intact myocardium. With time, the number of surface-sarcolemmal caveolae decreases in isolated cardiomyocytes. This is associated with a gradual increase in whole-cell membrane capacitance. Concurrently, there is a significant increase in area, diameter, and circularity of sub-sarcolemmal mitochondria, indicative of swelling. In addition, electron tomography data from intact heart illustrate the regular presence of caveolae not only at the surface sarcolemma, but also on transverse-tubular membranes in ventricular myocardium. Thus, caveolae are dynamic structures, present both at surface-sarcolemmal and transverse-tubular membranes. After cell isolation, the number of surface-sarcolemmal caveolae decreases significantly within a time frame relevant for single-cell research. The concurrent increase in cell capacitance suggests that membrane incorporation of surface-sarcolemmal caveolae underlies this, but internalization and/or micro-vesicle loss to the extracellular space may also contribute. Given that much of the research into cardiac caveolae-dependent signaling utilizes isolated cells, and since caveolae-dependent pathways matter for a wide range of other study targets, analysis of isolated cell data should take the time post-isolation into account.
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Affiliation(s)
- Rebecca A B Burton
- Department of Pharmacology, University of Oxford, Oxford, United Kingdom
| | - Eva A Rog-Zielinska
- National Heart and Lung Institute, Imperial College London, London, United Kingdom; Institute for Experimental Cardiovascular Medicine, University Heart Center Freiburg-Bad Krozingen, Faculty of Medicine, University of Freiburg, Freiburg, Germany.
| | | | - Rémi Peyronnet
- Institute for Experimental Cardiovascular Medicine, University Heart Center Freiburg-Bad Krozingen, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Ilona Bodi
- Institute for Experimental Cardiovascular Medicine, University Heart Center Freiburg-Bad Krozingen, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Martin Fink
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
| | - Judith Sheldon
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
| | - Andreas Hoenger
- Department of Molecular, Cellular and Developmental Biology, University of Colorado, Boulder, Colorado
| | - Sarah C Calaghan
- School of Biomedical Sciences, University of Leeds, Leeds, United Kingdom
| | - Gil Bub
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
| | - Peter Kohl
- Institute for Experimental Cardiovascular Medicine, University Heart Center Freiburg-Bad Krozingen, Faculty of Medicine, University of Freiburg, Freiburg, Germany
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Dressler FF, Bodi I, Menza M, Moss R, Bugger H, Bode C, Behrends JC, Seemann G, Odening KE. Interregional electro-mechanical heterogeneity in the rabbit myocardium. Prog Biophys Mol Biol 2017; 130:344-355. [PMID: 28655649 DOI: 10.1016/j.pbiomolbio.2017.06.016] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2017] [Revised: 06/21/2017] [Accepted: 06/22/2017] [Indexed: 12/28/2022]
Abstract
BACKGROUND Increased electrical heterogeneity has been causatively linked to arrhythmic disorders, yet the knowledge about physiological heterogeneity remains incomplete. This study investigates regional electro-mechanical heterogeneities in rabbits, one of the key animal models for arrhythmic disorders. METHODS AND FINDINGS 7 wild-type rabbits were examined by phase-contrast magnetic resonance imaging in vivo to assess cardiac wall movement velocities. Using a novel data-processing algorithm regional contraction-like profiles were calculated. Contraction started earlier and was longer in left ventricular (LV) apex than base. Patch clamp recordings showed longer action potentials (AP) in LV apex compared to the base of LV, septum, and right ventricle. Western blots of cardiac ion channels and calcium handling proteins showed lower expression of Cav1.2, KvLQT1, Kv1.4, NCX and Phospholamban in LV apex vs. base. A single-cell in silico model integrating the quantitative regional differences in ion channels reproduced a longer contraction and longer AP in apex vs. base. CONCLUSIONS Apico-basal electro-mechanical heterogeneity is physiologically present in the healthy rabbit heart. An apico-basal electro-mechanical gradient exists with longer APD and contraction duration in the apex and associated regionally heterogeneous expression of five key proteins. This pattern of apical mechanical dominance probably serves to increase pumping efficiency.
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Affiliation(s)
- Franz F Dressler
- Department of Cardiology and Angiology I, Heart Center University of Freiburg, Hugstetter Strasse 55, 79106 Freiburg, Germany; Faculty of Medicine, University of Freiburg, Breisacher Strasse 153, 79110 Freiburg, Germany
| | - Ilona Bodi
- Department of Cardiology and Angiology I, Heart Center University of Freiburg, Hugstetter Strasse 55, 79106 Freiburg, Germany; Faculty of Medicine, University of Freiburg, Breisacher Strasse 153, 79110 Freiburg, Germany
| | - Marius Menza
- Faculty of Medicine, University of Freiburg, Breisacher Strasse 153, 79110 Freiburg, Germany; Department of Medical Physics, Medical Center - University of Freiburg, Breisacher Straße 60a, 79106 Freiburg, Germany
| | - Robin Moss
- Faculty of Medicine, University of Freiburg, Breisacher Strasse 153, 79110 Freiburg, Germany; Institute of Biomedical Engineering, Karlsruhe Institute of Technology, Kaiserstrasse 12, 76128 Karlsruhe, Germany; Institute for Experimental Cardiovascular Medicine, Heart Center University of Freiburg, Medical Center - University of Freiburg, Elsaesserstrasse 2q, 79110 Freiburg, Germany
| | - Heiko Bugger
- Department of Cardiology and Angiology I, Heart Center University of Freiburg, Hugstetter Strasse 55, 79106 Freiburg, Germany; Faculty of Medicine, University of Freiburg, Breisacher Strasse 153, 79110 Freiburg, Germany
| | - Christoph Bode
- Department of Cardiology and Angiology I, Heart Center University of Freiburg, Hugstetter Strasse 55, 79106 Freiburg, Germany; Faculty of Medicine, University of Freiburg, Breisacher Strasse 153, 79110 Freiburg, Germany
| | - Jan C Behrends
- Faculty of Medicine, University of Freiburg, Breisacher Strasse 153, 79110 Freiburg, Germany; Department of Physiology, Laboratory for Membrane Physiology and -Technology, University of Freiburg, Hermann-Herder-Strasse 7, 79104 Freiburg, Germany
| | - Gunnar Seemann
- Faculty of Medicine, University of Freiburg, Breisacher Strasse 153, 79110 Freiburg, Germany; Institute of Biomedical Engineering, Karlsruhe Institute of Technology, Kaiserstrasse 12, 76128 Karlsruhe, Germany; Institute for Experimental Cardiovascular Medicine, Heart Center University of Freiburg, Medical Center - University of Freiburg, Elsaesserstrasse 2q, 79110 Freiburg, Germany
| | - Katja E Odening
- Department of Cardiology and Angiology I, Heart Center University of Freiburg, Hugstetter Strasse 55, 79106 Freiburg, Germany; Faculty of Medicine, University of Freiburg, Breisacher Strasse 153, 79110 Freiburg, Germany; Institute for Experimental Cardiovascular Medicine, Heart Center University of Freiburg, Medical Center - University of Freiburg, Elsaesserstrasse 2q, 79110 Freiburg, Germany.
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15
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Grünert SC, Bodi I, Odening KE. Possible mechanisms for sensorineural hearing loss and deafness in patients with propionic acidemia. Orphanet J Rare Dis 2017; 12:30. [PMID: 28193246 PMCID: PMC5307832 DOI: 10.1186/s13023-017-0585-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2016] [Accepted: 02/03/2017] [Indexed: 12/18/2022] Open
Abstract
Propionic acidemia is an inborn error of metabolism caused by deficiency of the mitochondrial enzyme propionyl-CoA carboxylase. Sensorineural deafness and severe hearing loss have been described as long-term complications of this disease, however, the mechanism has not yet been elucidated. We have recently shown by patch clamping experiments and Western blots that acute and chronic effects of accumulating metabolites such as propionic acid, propionylcarnitine and methylcitrate on the KvLQT1/KCNE1 channel complex cause long QT syndrome in patients with propionic acidemia by inhibition of K+ flow via this channel. The same KvLQT1/KCNE1 channel complex is expressed in the inner ear and essential for luminal potassium secretion into the endolymphatic space. A disruption of this K+ flow results in sensorineural hearing loss or deafness. It can be assumed that acute and chronic effects of accumulating metabolites on the KvLQT1/KCNE1 channel protein may similarly cause the hearing impairment of patients with propionic acidemia.
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Affiliation(s)
- S C Grünert
- Center of Pediatrics and Adolescent Medicine, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Mathildenstr. 1, 79106, Freiburg, Germany.
| | - I Bodi
- Department of Cardiology and Angiology I, University Heart Center Freiburg, Freiburg, Germany
| | - K E Odening
- Department of Cardiology and Angiology I, University Heart Center Freiburg, Freiburg, Germany
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Malhotra R, D'Souza KM, Staron ML, Birukov KG, Bodi I, Akhter SA. Retraction: Gαq-mediated activation of GRK2 by mechanical stretch in cardiac myocytes. THE ROLE OF PROTEIN KINASE C. J Biol Chem 2016; 291:14390. [DOI: 10.1074/jbc.a110.109272] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
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Smith N, Thakur B, Zebian B, Aizpurua M, Al-Sarraj S, Bodi I, Chandler C. PO83DESMOPLASTIC NON-INFANTILE GANGLIOGLIOMA - A RARE CASE OF MALIGNANT TRANSFORMATION AND A REVIEW OF THE LITERATURE. Neuro Oncol 2015. [DOI: 10.1093/neuonc/nov284.72] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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18
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Aizpurua M, Laxton R, Doey L, Bodi I, King A, Bhangoo R, Beaney R, Brazil L, Ashkan K, Al-Sarraj S. PO13ON THE BIOLOGICAL BEHAVIOUR AND PROGNOSIS OF ANAPLASTIC OLIGODENDROGLIOMA WITH NECROSIS. Neuro Oncol 2015. [DOI: 10.1093/neuonc/nov284.11] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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Nolan M, Troakes C, King A, Bodi I, Al-Sarraj S. Control tissue in brain banking: the importance of thorough neuropathological assessment. J Neural Transm (Vienna) 2015; 122:949-56. [PMID: 25673433 PMCID: PMC4498241 DOI: 10.1007/s00702-015-1376-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2014] [Accepted: 02/03/2015] [Indexed: 01/11/2023]
Abstract
Historically, control brain tissue was classified as such mainly by clinical history, and underwent limited neuropathological analysis. Significant progress has been made in recent years with the collection of more extensive clinical information and more specific classifications of neurodegenerative disease, aided by advances in histological processing and increasingly sensitive detection methods. We hypothesised that this may have resulted in certain pathologies previously going unidentified, due to insufficient block sampling and an inadequate range of stains, resulting in the disease not being recognised. We therefore investigated the significance of changes to our own protocols for examining control brain tissue before and after 2007. Control cases that were originally assessed before 2007 were re-assessed using our current staining protocol and antibodies, and compared with age-matched cases post-2007. We found that almost all cases that were originally described as neuropathologically normal displayed some level of pathology after re-analysis, with four cases displaying what we have termed ‘major’ pathology that previously went unidentified, emphasising on a small scale the importance of accurate neuropathological analysis of control tissue, and highlighting the inherent difficulty of traditionally classifying tissue simply as ‘disease’ or ‘control’. We hope our findings will stimulate debate within the brain banking community, with the eventual aim being standardisation of protocols for assessing controls across brain banks.
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Affiliation(s)
- M Nolan
- Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, Kings College London, London, UK,
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Laxton R, Doey L, Aizpurua M, Bodi I, King A, Chandler C, Bhangoo R, Beaney R, Brazil L, Ashkan K, Al-Sarraj S. P64 * QUANTITATIVE MGMT METHYLATION ANALYSIS BY PYROSEQUENCING REVEALS A STRONG CORRELATION BETWEEN 1P/19Q CO-DELETION AND HIGH LEVEL METHYLATION IN HIGH GRADE GLIOMAS. Neuro Oncol 2014. [DOI: 10.1093/neuonc/nou249.50] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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21
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Bodi I, Franke G, Pantulu ND, Wu K, Perez-Feliz S, Bode C, Zehender M, zur Hausen A, Brunner M, Odening KE. Differential effects of the β-adrenoceptor blockers carvedilol and metoprolol on SQT1- and SQT2-mutant channels. J Cardiovasc Electrophysiol 2013; 24:1163-71. [PMID: 23718892 DOI: 10.1111/jce.12178] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/07/2013] [Revised: 04/23/2013] [Accepted: 04/23/2013] [Indexed: 11/26/2022]
Abstract
BACKGROUND N588K-KCNH2 and V307L-KCNQ1 mutations lead to a gain-of-function of IKr and IKs thus causing short-QT syndromes (SQT1, SQT2). Combined pharmacotherapies using K(+) -channel-blockers and β-blockers are effective in SQTS. Since β-blockers can block IKr and IKs , we aimed at determining carvedilol's and metoprolol's electrophysiological effects on N588K-KCNH2 and V307L-KCNQ1 channels. METHODS Wild-type (WT)-KCNH2, WT-KCNQ1 and mutant N588K-KCNH2 and V307L-KCNQ1 channels were expressed in CHO-K1 or HEK-293T cells and IKs and IKr were recorded at baseline and during β-blocker exposure. RESULTS Carvedilol (10 μM) reduced IKs tail in WT- and V307L-KCNQ1 by 36.5 ± 5% and 18.6 ± 9% (P < 0.05). IC50 values were 16.3 μM (WT) and 46.1 μM (V307L), indicating a 2.8-fold decrease in carvedilol's IKs -blocking potency in V307L-KCNQ1. Carvedilol's (1 μM) inhibition of the IKr tail was attenuated in N588K-KCNH2 (4.5 ± 3% vs 50.3 ± 4%, WT, P < 0.001) with IC50 values of 2.8 μM (WT) and 25.4 μM (N588K). Carvedilol's IKr end-pulse inhibition, however, was increased in N588K-KCNH2 (10 μM, 60.7 ± 6% vs 36.5 ± 5%, WT, P < 0.01). Metoprolol (100 μM) reduced IKr end-pulse by 0.23 ± 3% (WT) and 74.1 ± 7% (N588K, P < 0.05), IKr tail by 32.9 ± 10% (WT) and 68.8 ± 7% (N588K, P < 0.05), and reduced IKs end-pulse by 18.3 ± 5% (WT) and 57.1 ± 11% (V307L, P < 0.05) and IKs tail by 3.3 ± 1% (WT) and 45.1 ± 13 % (V307L, P < 0.05), indicating an increased sensitivity to metoprolol in SQT mutated channels. CONCLUSIONS N588K-KCNH2 and V307L-KCNQ1 mutations decrease carvedilol's inhibition of the IKs or IKr tail but increase carvedilol's IKr end-pulse inhibition and metoprolol's inhibition of tail and end-pulse currents. These different effects on SQT1 and SQT2 mutated channels should be considered when using β-blocker therapy in SQTS patients.
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Affiliation(s)
- Ilona Bodi
- Heart Center Freiburg University, Department of Cardiology and Angiology I, Freiburg, Germany
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22
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Wei D, Rich P, Bridges L, Martin AJ, Chau I, Bodi I, MacDonald BK. Rare case of cerebral MALToma presenting with stroke-like symptoms and seizures. BMJ Case Rep 2013; 2013:bcr-2012-008494. [PMID: 23608841 DOI: 10.1136/bcr-2012-008494] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Mucosa-associated lymphoid tissue (MALT) cells are present in gastrointestinal mucosa but rarely found in the central nervous system (CNS). We describe an unusual and rare case of CNS MALT lymphoma in a patient presenting with stroke-like symptoms.
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Affiliation(s)
- D Wei
- Department of Neurology, Frenchay Hospital, Bristol, UK
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23
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Bodi I, Selway R, Bannister P, Doey L, Mullatti N, Elwes R, Honavar M. Diffuse form of dysembryoplastic neuroepithelial tumour: the histological and immunohistochemical features of a distinct entity showing transition to dysembryoplastic neuroepithelial tumour and ganglioglioma. Neuropathol Appl Neurobiol 2012; 38:411-25. [PMID: 21988102 DOI: 10.1111/j.1365-2990.2011.01225.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
AIMS A diffuse variant of dysembryoplastic neuroepithelial tumour (dDNT) has previously been described, which although composed of oligodendroglia-like cells (OLC), astrocytes and mature neurones, lacks the multinodularity and 'specific component' of typical DNT. The dDNT poses a significant challenge to the neuropathologist. This study was undertaken to further characterize the histological and immunohistochemical features of dDNT. MATERIALS AND METHODS Review of our archived material from epilepsy surgery identified 16 cases, in which features of dDNT predominated. Their histological and immunohistochemical features, including CD34 and nestin immunohistochemistry, were analysed. RESULTS Seven cases had the characteristics of pure dDNT. A further two cases of dDNT showed extension into the white matter with occasional dysplastic neurones. Two additional cases had similar features but with the presence of either single, or multiple small nodular clusters of OLC, in keeping with transition to classical DNT. Five cases showed ganglioglioma-like areas, of which three cases had micronodule formation but with predominant dDNT pattern. In all the cases the dDNT areas showed strong CD34 and less intense nestin immunoreactivity and microglial activation highlighting the full extent of the lesions. There was variable overlap between CD34 and nestin positivity within the micronodular and/or ganglioglioma-like areas. CONCLUSIONS Immunoreactivity for CD34 and nestin characterizes the dDNT and helps to distinguish it from other lesions associated with epilepsy. Histological evidence indicative of transition of dDNT to other forms of DNT and ganglioglioma suggests that dDNT might be an early histogenetic form of these glioneuronal tumours.
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Affiliation(s)
- I Bodi
- Department of Clinical Neuropathology Neurosurgery, King's College Hospital NHS Foundation Trust, London, UK.
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24
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25
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Haidari G, Singh S, Freudenthal B, Peters B, Kulasegaram R, Desai M, Bodi I. B2 Space occupying lesion in an HIV positive male- are common things always common? Br J Vener Dis 2012. [DOI: 10.1136/sextrans-2012-050601d.2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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26
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Goonasekera SA, Hammer K, Auger-Messier M, Bodi I, Chen X, Zhang H, Reiken S, Elrod JW, Correll RN, York AJ, Sargent MA, Hofmann F, Moosmang S, Marks AR, Houser SR, Bers DM, Molkentin JD. Decreased cardiac L-type Ca²⁺ channel activity induces hypertrophy and heart failure in mice. J Clin Invest 2011; 122:280-90. [PMID: 22133878 DOI: 10.1172/jci58227] [Citation(s) in RCA: 128] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2011] [Accepted: 10/12/2011] [Indexed: 02/06/2023] Open
Abstract
Antagonists of L-type Ca²⁺ channels (LTCCs) have been used to treat human cardiovascular diseases for decades. However, these inhibitors can have untoward effects in patients with heart failure, and their overall therapeutic profile remains nebulous given differential effects in the vasculature when compared with those in cardiomyocytes. To investigate this issue, we examined mice heterozygous for the gene encoding the pore-forming subunit of LTCC (calcium channel, voltage-dependent, L type, α1C subunit [Cacna1c mice; referred to herein as α1C⁻/⁺ mice]) and mice in which this gene was loxP targeted to achieve graded heart-specific gene deletion (termed herein α1C-loxP mice). Adult cardiomyocytes from the hearts of α1C⁻/⁺ mice at 10 weeks of age showed a decrease in LTCC current and a modest decrease in cardiac function, which we initially hypothesized would be cardioprotective. However, α1C⁻/⁺ mice subjected to pressure overload stimulation, isoproterenol infusion, and swimming showed greater cardiac hypertrophy, greater reductions in ventricular performance, and greater ventricular dilation than α1C⁺/⁺ controls. The same detrimental effects were observed in α1C-loxP animals with a cardiomyocyte-specific deletion of one allele. More severe reductions in α1C protein levels with combinatorial deleted alleles produced spontaneous cardiac hypertrophy before 3 months of age, with early adulthood lethality. Mechanistically, our data suggest that a reduction in LTCC current leads to neuroendocrine stress, with sensitized and leaky sarcoplasmic reticulum Ca²⁺ release as a compensatory mechanism to preserve contractility. This state results in calcineurin/nuclear factor of activated T cells signaling that promotes hypertrophy and disease.
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Affiliation(s)
- Sanjeewa A Goonasekera
- Department of Pediatrics, University of Cincinnati, Cincinnati Children's Hospital Medical Center, Howard Hughes Medical Institute, Cincinnati, Ohio 45229, USA
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27
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Hammer KP, Goonasekera SA, Bodi I, Moosmang S, Hofmann F, Molkentin JD, Bers DM. Suppression of Cardiac L-Type Ca Channel Activity Causes Cardiac Hypertrophy. Biophys J 2011. [DOI: 10.1016/j.bpj.2010.12.1793] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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28
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Al Moamen NJ, Prasad V, Bodi I, Miller ML, Neiman ML, Lasko VM, Alper SL, Wieczorek DF, Lorenz JN, Shull GE. Loss of the AE3 anion exchanger in a hypertrophic cardiomyopathy model causes rapid decompensation and heart failure. J Mol Cell Cardiol 2010; 50:137-46. [PMID: 21056571 DOI: 10.1016/j.yjmcc.2010.10.028] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/30/2010] [Revised: 10/13/2010] [Accepted: 10/24/2010] [Indexed: 02/08/2023]
Abstract
The AE3 Cl(-)/HCO(3)(-) exchanger is abundantly expressed in the sarcolemma of cardiomyocytes, where it mediates Cl(-)-uptake and HCO(3)(-)-extrusion. Inhibition of AE3-mediated Cl(-)/HCO(3)(-) exchange has been suggested to protect against cardiac hypertrophy; however, other studies indicate that AE3 might be necessary for optimal cardiac function. To test these hypotheses we crossed AE3-null mice, which appear phenotypically normal, with a hypertrophic cardiomyopathy mouse model carrying a Glu180Gly mutation in α-tropomyosin (TM180). Loss of AE3 had no effect on hypertrophy; however, survival of TM180/AE3 double mutants was sharply reduced compared with TM180 single mutants. Analysis of cardiac performance revealed impaired cardiac function in TM180 and TM180/AE3 mutants. TM180/AE3 double mutants were more severely affected and exhibited little response to β-adrenergic stimulation, a likely consequence of their more rapid progression to heart failure. Increased expression of calmodulin-dependent kinase II and protein phosphatase 1 and differences in methylation and localization of protein phosphatase 2A were observed, but were similar in single and double mutants. Phosphorylation of phospholamban on Ser16 was sharply increased in both single and double mutants relative to wild-type hearts under basal conditions, leading to reduced reserve capacity for β-adrenergic stimulation of phospholamban phosphorylation. Imaging analysis of isolated myocytes revealed reductions in amplitude and decay of Ca(2+) transients in both mutants, with greater reductions in TM180/AE3 mutants, consistent with the greater severity of their heart failure phenotype. Thus, in the TM180 cardiomyopathy model, loss of AE3 had no apparent anti-hypertrophic effect and led to more rapid decompensation and heart failure.
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Affiliation(s)
- Nabeel J Al Moamen
- Department of Molecular Genetics, University of Cincinnati College of Medicine, Cincinnati, OH 45267, USA
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29
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Nakayama H, Bodi I, Maillet M, DeSantiago J, Domeier TL, Mikoshiba K, Lorenz JN, Blatter LA, Bers DM, Molkentin JD. The IP3 receptor regulates cardiac hypertrophy in response to select stimuli. Circ Res 2010; 107:659-66. [PMID: 20616315 DOI: 10.1161/circresaha.110.220038] [Citation(s) in RCA: 134] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
RATIONALE Inositol 1,4,5-trisphosphate (IP(3)) is a second messenger that regulates intracellular Ca(2+) release through IP(3) receptors located in the sarco(endo)plasmic reticulum of cardiac myocytes. Many prohypertrophic G protein-coupled receptor (GPCR) signaling events lead to IP(3) liberation, although its importance in transducing the hypertrophic response has not been established in vivo. OBJECTIVE Here, we generated conditional, heart-specific transgenic mice with both gain- and loss-of-function for IP(3) receptor signaling to examine its hypertrophic growth effects following pathological and physiological stimulation. METHODS AND RESULTS Overexpression of the mouse type-2 IP(3) receptor (IP(3)R2) in the heart generated mild baseline cardiac hypertrophy at 3 months of age. Isolated myocytes from overexpressing lines showed increased Ca(2+) transients and arrhythmias in response to endothelin-1 stimulation. Although low levels of IP(3)R2 overexpression failed to augment/synergize cardiac hypertrophy following 2 weeks of pressure-overload stimulation, such levels did enhance hypertrophy following 2 weeks of isoproterenol infusion, in response to Galphaq overexpression, and/or in response to exercise stimulation. To inhibit IP(3) signaling in vivo, we generated transgenic mice expressing an IP(3) chelating protein (IP(3)-sponge). IP(3)-sponge transgenic mice abrogated cardiac hypertrophy in response to isoproterenol and angiotensin II infusion but not pressure-overload stimulation. Mechanistically, IP(3)R2-enhanced cardiac hypertrophy following isoproterenol infusion was significantly reduced in the calcineurin-Abeta-null background. CONCLUSION These results indicate that IP(3)-mediated Ca(2+) release plays a central role in regulating cardiac hypertrophy downstream of GPCR signaling, in part, through a calcineurin-dependent mechanism.
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Affiliation(s)
- Hiroyuki Nakayama
- Howard Hughes Medical Institute, Cincinnati Children's Hospital Medical Center, 240 Albert Sabin Way, Cincinnati, OH 45229-3039, USA
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30
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Malhotra R, D'Souza KM, Staron ML, Birukov KG, Bodi I, Akhter SA. G alpha(q)-mediated activation of GRK2 by mechanical stretch in cardiac myocytes: the role of protein kinase C. J Biol Chem 2010; 285:13748-60. [PMID: 20194499 PMCID: PMC2859538 DOI: 10.1074/jbc.m110.109272] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2010] [Revised: 02/25/2010] [Indexed: 01/08/2023] Open
Abstract
G protein-coupled receptor kinase-2 (GRK2) is a critical regulator of beta-adrenergic receptor (beta-AR) signaling and cardiac function. We studied the effects of mechanical stretch, a potent stimulus for cardiac myocyte hypertrophy, on GRK2 activity and beta-AR signaling. To eliminate neurohormonal influences, neonatal rat ventricular myocytes were subjected to cyclical equi-biaxial stretch. A hypertrophic response was confirmed by "fetal" gene up-regulation. GRK2 activity in cardiac myocytes was increased 4.2-fold at 48 h of stretch versus unstretched controls. Adenylyl cyclase activity was blunted in sarcolemmal membranes after stretch, demonstrating beta-AR desensitization. The hypertrophic response to mechanical stretch is mediated primarily through the G alpha(q)-coupled angiotensin II AT(1) receptor leading to activation of protein kinase C (PKC). PKC is known to phosphorylate GRK2 at the N-terminal serine 29 residue, leading to kinase activation. Overexpression of a mini-gene that inhibits receptor-G alpha(q) coupling blunted stretch-induced hypertrophy and GRK2 activation. Short hairpin RNA-mediated knockdown of PKC alpha also significantly attenuated stretch-induced GRK2 activation. Overexpression of a GRK2 mutant (S29A) in cardiac myocytes inhibited phosphorylation of GRK2 by PKC, abolished stretch-induced GRK2 activation, and restored adenylyl cyclase activity. Cardiac-specific activation of PKC alpha in transgenic mice led to impaired beta-agonist-stimulated ventricular function, blunted cyclase activity, and increased GRK2 phosphorylation and activity. Phosphorylation of GRK2 by PKC appears to be the primary mechanism of increased GRK2 activity and impaired beta-AR signaling after mechanical stretch. Cross-talk between hypertrophic signaling at the level of PKC and beta-AR signaling regulated by GRK2 may be an important mechanism in the transition from compensatory ventricular hypertrophy to heart failure.
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MESH Headings
- Animals
- Cells, Cultured
- Enzyme Activation/genetics
- G-Protein-Coupled Receptor Kinase 2/genetics
- G-Protein-Coupled Receptor Kinase 2/metabolism
- GTP-Binding Protein alpha Subunits, Gq-G11/genetics
- GTP-Binding Protein alpha Subunits, Gq-G11/metabolism
- Gene Knockdown Techniques
- Heart Ventricles/enzymology
- Mice
- Mice, Knockout
- Myocytes, Cardiac/enzymology
- Phosphorylation/genetics
- Protein Kinase C-alpha/genetics
- Protein Kinase C-alpha/metabolism
- Rats
- Receptor, Angiotensin, Type 1/genetics
- Receptor, Angiotensin, Type 1/metabolism
- Receptors, Adrenergic, beta/genetics
- Receptors, Adrenergic, beta/metabolism
- Signal Transduction
- Stress, Physiological
- Time Factors
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Affiliation(s)
- Ricky Malhotra
- From the Department of Surgery, Section of Cardiac and Thoracic Surgery, and
| | - Karen M. D'Souza
- From the Department of Surgery, Section of Cardiac and Thoracic Surgery, and
| | - Michelle L. Staron
- From the Department of Surgery, Section of Cardiac and Thoracic Surgery, and
| | - Konstantin G. Birukov
- Department of Medicine, Section of Pulmonary/Critical Care, University of Chicago Medical Center, Chicago, Illinois 60637 and
| | - Ilona Bodi
- the Institute for Molecular Pharmacology and Biophysics, University of Cincinnati, Cincinnati, Ohio 45267
| | - Shahab A. Akhter
- From the Department of Surgery, Section of Cardiac and Thoracic Surgery, and
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31
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Rajan S, Jagatheesan G, Karam CN, Alves ML, Bodi I, Schwartz A, Bulcao CF, D'Souza KM, Akhter SA, Boivin GP, Dube DK, Petrashevskaya N, Herr AB, Hullin R, Liggett SB, Wolska BM, Solaro RJ, Wieczorek DF. Molecular and functional characterization of a novel cardiac-specific human tropomyosin isoform. Circulation 2010; 121:410-8. [PMID: 20065163 DOI: 10.1161/circulationaha.109.889725] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Tropomyosin (TM), an essential actin-binding protein, is central to the control of calcium-regulated striated muscle contraction. Although TPM1alpha (also called alpha-TM) is the predominant TM isoform in human hearts, the precise TM isoform composition remains unclear. METHODS AND RESULTS In this study, we quantified for the first time the levels of striated muscle TM isoforms in human heart, including a novel isoform called TPM1kappa. By developing a TPM1kappa-specific antibody, we found that the TPM1kappa protein is expressed and incorporated into organized myofibrils in hearts and that its level is increased in human dilated cardiomyopathy and heart failure. To investigate the role of TPM1kappa in sarcomeric function, we generated transgenic mice overexpressing cardiac-specific TPM1kappa. Incorporation of increased levels of TPM1kappa protein in myofilaments leads to dilated cardiomyopathy. Physiological alterations include decreased fractional shortening, systolic and diastolic dysfunction, and decreased myofilament calcium sensitivity with no change in maximum developed tension. Additional biophysical studies demonstrate less structural stability and weaker actin-binding affinity of TPM1kappa compared with TPM1alpha. CONCLUSIONS This functional analysis of TPM1kappa provides a possible mechanism for the consequences of the TM isoform switch observed in dilated cardiomyopathy and heart failure patients.
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Affiliation(s)
- Sudarsan Rajan
- Department of Molecular Genetics, Biochemistry, and Microbiology, University of Cincinnati Medical Center, Cincinnati, OH 45267-0524, USA
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32
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Nakayama H, Bodi I, Correll RN, Chen X, Lorenz J, Houser SR, Robbins J, Schwartz A, Molkentin JD. alpha1G-dependent T-type Ca2+ current antagonizes cardiac hypertrophy through a NOS3-dependent mechanism in mice. J Clin Invest 2009; 119:3787-96. [PMID: 19920353 DOI: 10.1172/jci39724] [Citation(s) in RCA: 79] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2009] [Accepted: 09/23/2009] [Indexed: 12/21/2022] Open
Abstract
In noncontractile cells, increases in intracellular Ca2+ concentration serve as a second messenger to signal proliferation, differentiation, metabolism, motility, and cell death. Many of these Ca2+-dependent regulatory processes operate in cardiomyocytes, although it remains unclear how Ca2+ serves as a second messenger given the high Ca2+ concentrations that control contraction. T-type Ca2+ channels are reexpressed in adult ventricular myocytes during pathologic hypertrophy, although their physiologic function remains unknown. Here we generated cardiac-specific transgenic mice with inducible expression of alpha1G, which generates Cav3.1 current, to investigate whether this type of Ca2+ influx mechanism regulates the cardiac hypertrophic response. Unexpectedly, alpha1G transgenic mice showed no cardiac pathology despite large increases in Ca2+ influx, and they were even partially resistant to pressure overload-, isoproterenol-, and exercise-induced cardiac hypertrophy. Conversely, alpha1G-/- mice displayed enhanced hypertrophic responses following pressure overload or isoproterenol infusion. Enhanced hypertrophy and disease in alpha1G-/- mice was rescued with the alpha1G transgene, demonstrating a myocyte-autonomous requirement of alpha1G for protection. Mechanistically, alpha1G interacted with NOS3, which augmented cGMP-dependent protein kinase type I activity in alpha1G transgenic hearts after pressure overload. Further, the anti-hypertrophic effect of alpha1G overexpression was abrogated by a NOS3 inhibitor and by crossing the mice onto the Nos3-/- background. Thus, cardiac alpha1G reexpression and its associated pool of T-type Ca2+ antagonize cardiac hypertrophy through a NOS3-dependent signaling mechanism.
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Affiliation(s)
- Hiroyuki Nakayama
- Department of Pediatrics, University of Cincinnati, Division of Molecular Cardiovascular Biology, Howard Hughes Medical Institute, Children's Hospital Medical Center, Cincinnati, Ohio, USA
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33
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Forrest K, Bodi I, Al-Sarraj S, Tan S, Pitt M, Kayani R, Durward A, McDougall M, Irving M, Jungbluth H, Wraige E. G.P.7.06 Infantile onset muscle stiffness with marked myofibrillar disruption on muscle biopsy. Neuromuscul Disord 2009. [DOI: 10.1016/j.nmd.2009.06.144] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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35
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Fuller-Bicer GA, Varadi G, Koch SE, Ishii M, Bodi I, Kadeer N, Muth JN, Mikala G, Petrashevskaya NN, Jordan MA, Zhang SP, Qin N, Flores CM, Isaacsohn I, Varadi M, Mori Y, Jones WK, Schwartz A. Targeted disruption of the voltage-dependent calcium channel alpha2/delta-1-subunit. Am J Physiol Heart Circ Physiol 2009; 297:H117-24. [PMID: 19429829 DOI: 10.1152/ajpheart.00122.2009] [Citation(s) in RCA: 114] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Cardiac L-type voltage-dependent Ca(2+) channels are heteromultimeric polypeptide complexes of alpha(1)-, alpha(2)/delta-, and beta-subunits. The alpha(2)/delta-1-subunit possesses a stereoselective, high-affinity binding site for gabapentin, widely used to treat epilepsy and postherpetic neuralgic pain as well as sleep disorders. Mutations in alpha(2)/delta-subunits of voltage-dependent Ca(2+) channels have been associated with different diseases, including epilepsy. Multiple heterologous coexpression systems have been used to study the effects of the deletion of the alpha(2)/delta-1-subunit, but attempts at a conventional knockout animal model have been ineffective. We report the development of a viable conventional knockout mouse using a construct targeting exon 2 of alpha(2)/delta-1. While the deletion of the subunit is not lethal, these animals lack high-affinity gabapentin binding sites and demonstrate a significantly decreased basal myocardial contractility and relaxation and a decreased L-type Ca(2+) current peak current amplitude. This is a novel model for studying the function of the alpha(2)/delta-1-subunit and will be of importance in the development of new pharmacological therapies.
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Affiliation(s)
- Geraldine A Fuller-Bicer
- Institute of Molecular Pharmacology and Biophysics, Department of Surgery, University of Cincinnati, College of Medicine, Cincinnati, OH 45267-0828, USA
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36
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Ugenti MP, Bodi I, Koch SE, Budriesi R, Ioan P, Hullin R, Chiarini A, Schwartz A. Cardiovascular profile of newly developed Diltiazem analogs. Biophys J 2009. [DOI: 10.1016/j.bpj.2008.12.851] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
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37
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Prasad V, Bodi I, Meyer JW, Wang Y, Ashraf M, Engle SJ, Doetschman T, Sisco K, Nieman ML, Miller ML, Lorenz JN, Shull GE. Impaired cardiac contractility in mice lacking both the AE3 Cl-/HCO3- exchanger and the NKCC1 Na+-K+-2Cl- cotransporter: effects on Ca2+ handling and protein phosphatases. J Biol Chem 2008; 283:31303-14. [PMID: 18779325 PMCID: PMC2581574 DOI: 10.1074/jbc.m803706200] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2008] [Revised: 08/27/2008] [Indexed: 12/27/2022] Open
Abstract
To analyze the cardiac functions of AE3, we disrupted its gene (Slc4a3) in mice. Cl(-)/HCO3(-) exchange coupled with Na+-dependent acid extrusion can mediate pH-neutral Na+ uptake, potentially affecting Ca2+ handling via effects on Na+/Ca2+ exchange. AE3 null mice appeared normal, however, and AE3 ablation had no effect on ischemia-reperfusion injury in isolated hearts or cardiac performance in vivo. The NKCC1 Na+-K+-2Cl(-) cotransporter also mediates Na+ uptake, and loss of NKCC1 alone does not impair contractility. To further stress the AE3-deficient myocardium, we combined the AE3 and NKCC1 knock-outs. Double knock-outs had impaired contraction and relaxation both in vivo and in isolated ventricular myocytes. Ca2+ transients revealed an apparent increase in Ca2+ clearance in double null cells. This was unlikely to result from increased Ca2+ sequestration, since the ratio of phosphorylated phospholamban to total phospholamban was sharply reduced in all three mutant hearts. Instead, Na+/Ca2+ exchanger activity was found to be enhanced in double null cells. Systolic Ca2+ was unaltered, however, suggesting more direct effects on the contractile apparatus of double null myocytes. Expression of the catalytic subunit of protein phosphatase 1 was increased in all mutant hearts. There was also a dramatic reversal, between single null and double null hearts, in the carboxymethylation and localization to the myofibrillar fraction, of the catalytic subunit of protein phosphatase 2A, which corresponded to the loss of normal contractility in double null hearts. These data show that AE3 and NKCC1 affect Ca2+ handling, PLN regulation, and expression and localization of major cardiac phosphatases and that their combined loss impairs cardiac function.
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Affiliation(s)
- Vikram Prasad
- Department of Molecular Genetics, Biochemistry, and Microbiology, University of Cincinnati College of Medicine, Cincinnati, Ohio 45267-0524, USA
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Bodi I, Jessen W, D'souza K, Koch S, Akhter S, Wolf R, Schwartz A, Aronow B. Cell Adhesion and Fibrosis Affect the Mechanical and Electrical Coupling Of Cardiomyocytes in Human Atrial Fibrillation. FASEB J 2008. [DOI: 10.1096/fasebj.22.1_supplement.798.11] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Ilona Bodi
- SurgeryUniversity of CincinnatiCincinnatiOH
| | - Walter Jessen
- Division of Biomedical InformaticsCincinnati Children's Research FoundationCincinnatiOH
| | | | | | | | | | | | - Bruce Aronow
- Division of Biomedical InformaticsCincinnati Children's Research FoundationCincinnatiOH
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Crocker M, deSouza R, Epaliyanage P, Bodi I, Deasy N, Selway R. Masson's tumour in the right parietal lobe after stereotactic radiosurgery for cerebellar AVM: case report and review. Clin Neurol Neurosurg 2007; 109:811-5. [PMID: 17714859 DOI: 10.1016/j.clineuro.2007.07.005] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2007] [Revised: 06/14/2007] [Accepted: 07/09/2007] [Indexed: 12/20/2022]
Abstract
We present a 50-year-old patient who had undergone stereotactic radiosurgery for a cerebellar vermian arteriovenous malformation. On routine surveillance MR imaging a lesion suggestive of a meningioma was demonstrated and removed. Histologically it was found to be intravascular papillary endothelial hyperplasia (Masson's tumour). The characteristic radiological and histological findings are presented. Aspects of management of this rare tumour are discussed. Given that cases are often found in combination with a vascular abnormality, we discuss the possibility of a change in local haemodynamics after radiosurgery promoting development of this tumour.
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Affiliation(s)
- M Crocker
- Department of Neurosurgery, King's College Hospital, Denmark Hill, London SE5 9RS, United Kingdom.
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Bodi I, D'Souza K, Liggett S, Schwartz A. Enhanced Ca2+ transient and cell contractility is associated with decreased Cx43 in β1-ARG389 mice. J Mol Cell Cardiol 2007. [DOI: 10.1016/j.yjmcc.2007.03.249] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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41
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Bodi I, D'Souza K, Rubio M, Nicolaou S, Fuller G, Conforti L, Molkentin J, Schwartz A. Calcineurin Aβ null partially rescues impaired cardiac function in targeted overexpression of L-LVDCC α1C. J Mol Cell Cardiol 2007. [DOI: 10.1016/j.yjmcc.2007.03.104] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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42
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Hullin R, Matthes J, von Vietinghoff S, Bodi I, Rubio M, D'Souza K, Friedrich Khan I, Rottländer D, Hoppe UC, Mohacsi P, Schmitteckert E, Gilsbach R, Bünemann M, Hein L, Schwartz A, Herzig S. Increased expression of the auxiliary beta(2)-subunit of ventricular L-type Ca(2)+ channels leads to single-channel activity characteristic of heart failure. PLoS One 2007; 2:e292. [PMID: 17356701 PMCID: PMC1808423 DOI: 10.1371/journal.pone.0000292] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2006] [Accepted: 02/19/2007] [Indexed: 11/25/2022] Open
Abstract
Background Increased activity of single ventricular L-type Ca2+-channels (L-VDCC) is a hallmark in human heart failure. Recent findings suggest differential modulation by several auxiliary β-subunits as a possible explanation. Methods and Results By molecular and functional analyses of human and murine ventricles, we find that enhanced L-VDCC activity is accompanied by altered expression pattern of auxiliary L-VDCC β-subunit gene products. In HEK293-cells we show differential modulation of single L-VDCC activity by coexpression of several human cardiac β-subunits: Unlike β1 or β3 isoforms, β2a and β2b induce a high-activity channel behavior typical of failing myocytes. In accordance, β2-subunit mRNA and protein are up-regulated in failing human myocardium. In a model of heart failure we find that mice overexpressing the human cardiac CaV1.2 also reveal increased single-channel activity and sarcolemmal β2 expression when entering into the maladaptive stage of heart failure. Interestingly, these animals, when still young and non-failing (“Adaptive Phase”), reveal the opposite phenotype, viz: reduced single-channel activity accompanied by lowered β2 expression. Additional evidence for the cause-effect relationship between β2-subunit expression and single L-VDCC activity is provided by newly engineered, double-transgenic mice bearing both constitutive CaV1.2 and inducible β2 cardiac overexpression. Here in non-failing hearts induction of β2-subunit overexpression mimicked the increase of single L-VDCC activity observed in murine and human chronic heart failure. Conclusions Our study presents evidence of the pathobiochemical relevance of β2-subunits for the electrophysiological phenotype of cardiac L-VDCC and thus provides an explanation for the single L-VDCC gating observed in human and murine heart failure.
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Affiliation(s)
- Roger Hullin
- Department of Cardiology, Swiss Heart Center Bern, University Hospital, Bern, Switzerland
- * To whom correspondence should be addressed. E-mail: (RH); (SH); (AS)
| | - Jan Matthes
- Department of Pharmacology, University of Cologne, Cologne, Germany
| | - Sibylle von Vietinghoff
- Department of Pharmacology, University of Wuerzburg, Wuerzburg, Germany
- Franz Volhard Clinic, Nephrology/Hypertension Section, Medical Faculty of the Charité, Berlin, Germany
| | - Ilona Bodi
- University of Cincinnati College of Medicine, Institute of Molecular Pharmacology and Biophysics, University of Cincinnati, Cincinnati, Ohio, United States of America
| | - Marta Rubio
- University of Cincinnati College of Medicine, Institute of Molecular Pharmacology and Biophysics, University of Cincinnati, Cincinnati, Ohio, United States of America
| | - Karen D'Souza
- University of Cincinnati College of Medicine, Institute of Molecular Pharmacology and Biophysics, University of Cincinnati, Cincinnati, Ohio, United States of America
| | - Ismail Friedrich Khan
- Department of Pharmacology, University of Cologne, Cologne, Germany
- Center of Molecular Medicine, University of Cologne, Cologne, Germany
| | | | - Uta C. Hoppe
- Center of Molecular Medicine, University of Cologne, Cologne, Germany
| | - Paul Mohacsi
- Department of Cardiology, Swiss Heart Center Bern, University Hospital, Bern, Switzerland
| | - Eva Schmitteckert
- Department of Pharmacology, University of Wuerzburg, Wuerzburg, Germany
| | - Ralf Gilsbach
- Department of Experimental and Clinical Pharmacology and Toxicology, University of Freiburg, Freiburg, Germany
| | - Moritz Bünemann
- Department of Pharmacology, University of Wuerzburg, Wuerzburg, Germany
| | - Lutz Hein
- Department of Pharmacology, University of Wuerzburg, Wuerzburg, Germany
- Department of Experimental and Clinical Pharmacology and Toxicology, University of Freiburg, Freiburg, Germany
| | - Arnold Schwartz
- University of Cincinnati College of Medicine, Institute of Molecular Pharmacology and Biophysics, University of Cincinnati, Cincinnati, Ohio, United States of America
- * To whom correspondence should be addressed. E-mail: (RH); (SH); (AS)
| | - Stefan Herzig
- Department of Pharmacology, University of Cologne, Cologne, Germany
- Center of Molecular Medicine, University of Cologne, Cologne, Germany
- * To whom correspondence should be addressed. E-mail: (RH); (SH); (AS)
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Bodi I, D'Souza K, Liggett S, Schwartz A. WITHDRAWN: Enhanced Ca2+ transient & cell contractility is associated with decreased Cx43 in β1-ARG389 mice. J Mol Cell Cardiol 2007. [DOI: 10.1016/j.yjmcc.2007.03.853] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Gong N, Bodi I, Zobel C, Schwartz A, Molkentin JD, Backx PH. Calcineurin increases cardiac transient outward K+ currents via transcriptional up-regulation of Kv4.2 channel subunits. J Biol Chem 2006; 281:38498-506. [PMID: 17060317 DOI: 10.1074/jbc.m607774200] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Fast transient outward potassium currents (I(to,f)) are critical determinants of regional heterogeneity of cardiomyocyte repolarization as well as cardiomyocyte contractility. Additionally, I(to,f) densities are markedly down-regulated in cardiac hypertrophy and heart disease, conditions associated with activation of the serine/threonine phosphatase calcineurin (Cn). In this study, we investigated the regulation of I(to,f) expression by Cn in cultured neonatal rat ventricular myocytes (NRVMs) with and without alpha(1)-adrenoreceptor stimulation with phenylephrine (PE). Overexpression of constitutively active Cn in NRVMs induced hypertrophy and caused profound increases in I(to,f) density as well as Kv4.2 mRNA and protein expression and promoter activity, without affecting Kv4.3 or KChIP2 levels. The effects of Cn on hypertrophy, I(to,f), and Kv4.2 transcription were associated with NFAT activation and were abrogated by NFAT inhibition. Despite activating Cn and inducing hypertrophy in NRVMs, PE resulted in profound down-regulation of I(to,f) densities as well as Kv4.2, Kv4.3, and KChIP2 expression. Although hypertrophy and NFAT activation were inhibited by the Cn inhibitory peptide CAIN, I(to,f) and Kv4.2 expression were further reduced by CAIN, whereas Cn overexpression eliminated PE-induced reductions in I(to,f) and Kv4.2 expression without affecting Kv4.3 or KChIP2 levels. We conclude that Cn increases cardiac I(to,f) densities by positively regulating Kv4.2 gene transcription. Consistent with this conclusion, we found that I(to,f) was increased in myocytes isolated from young mice overexpressing Cn prior to the development of heart disease. This positive regulation of Kv4.2 transcription by Cn activation is expected to minimize the reductions in I(to,f) and Kv4.2 expression observed in hypertrophic cardiomyocytes.
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Affiliation(s)
- Nanling Gong
- Departments of Physiology and Medicine, Heart and Stroke/Richard Lewar Centre of Excellence, University Health Network, University of Toronto, 150 College Street, Toronto, Ontario M5S 3E2, Canada
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Abstract
The manner in which Ca2+-sensitive signaling proteins are activated in contracting cardiomyocytes is an intriguing theoretical problem given that the cytoplasm is continually bathed with systolic Ca2+ concentrations that should maximally activate most Ca2+-sensitive signaling kinases and phosphatases. Store-operated Ca2+ entry, partially attributed to transient receptor potential (TRP) proteins, can mediate activation of the Ca2+-sensitive phosphatase calcineurin in nonexcitable cells. Here we investigated the gain-of-function phenotype associated with TRPC3 expression in the mouse heart using transgenesis to examine the potential role of store-operated Ca2+ entry in regulating cardiac calcineurin activation and ensuing hypertrophy/myopathy. Adult myocytes isolated from TRPC3 transgenic mice showed abundant store-operated Ca2+ entry that was inhibited with SKF96365 but not verapamil or KB-R7943. Associated with this induction in store-operated Ca2+ entry, TRPC3 transgenic mice showed increased calcineurin-nuclear factor of activated T cells (NFAT) activation in vivo, cardiomyopathy, and increased hypertrophy after neuroendocrine agonist or pressure overload stimulation. The cardiomyopathic phenotype and increased hypertrophy after pressure overload stimulation were blocked by targeted disruption of the calcineurin Abeta gene. Thus, enhanced store-operated Ca2+ entry in the heart can regulate calcineurin-NFAT signaling in vivo, which could secondarily impact the hypertrophic response and cardiomyopathy.
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Affiliation(s)
- Hiroyuki Nakayama
- Department of Pediatrics, University of Cincinnati, Children's Hospital Medical Center, 3333 Burnet Ave, Cincinnati, OH 45229, USA
| | - Benjamin J. Wilkin
- Department of Pediatrics, University of Cincinnati, Children's Hospital Medical Center, 3333 Burnet Ave, Cincinnati, OH 45229, USA
| | - Ilona Bodi
- University of Cincinnati. Department of Surgery, 231 Albert Sabin Way, Cincinnati OH 45267, USA
| | - Jeffery D. Molkentin
- Department of Pediatrics, University of Cincinnati, Children's Hospital Medical Center, 3333 Burnet Ave, Cincinnati, OH 45229, USA
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Gregory KN, Ginsburg KS, Bodi I, Hahn H, Marreez YMA, Song Q, Padmanabhan PA, Mitton BA, Waggoner JR, Del Monte F, Park WJ, Dorn GW, Bers DM, Kranias EG. Histidine-rich Ca binding protein: a regulator of sarcoplasmic reticulum calcium sequestration and cardiac function. J Mol Cell Cardiol 2006; 40:653-65. [PMID: 16600288 DOI: 10.1016/j.yjmcc.2006.02.003] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/30/2005] [Revised: 01/19/2006] [Accepted: 02/10/2006] [Indexed: 02/01/2023]
Abstract
Defects in the pathways that regulate cardiac sarcoplasmic reticulum (SR) calcium (Ca) cycling represent prime targets for driving the deterioration of function and progression to heart failure. We hypothesized that the histidine-rich Ca binding protein (HRC) in the SR may be involved in SR Ca cycling and that alterations in HRC levels would result in abnormal cardiac Ca homeostasis. In order to test this hypothesis, we generated transgenic mice with cardiac overexpression (3-fold) of HRC. Increased cardiac HRC levels were associated with impaired SR Ca uptake rates (35%) and attenuated cardiomyocyte Ca transient decay (38%), without alterations in peak Ca transients or SR Ca load. The depressed SR Ca sequestration was associated with attenuated rate of Ca extrusion via Na-Ca exchange. Triadin protein expression levels and L-type Ca channel current density were increased, while the channel inactivation kinetics were not altered. Impaired SR Ca uptake and delayed Ca decline rates triggered hypertrophy and compromised the heart's responses to increased stress by either hemodynamic overload or the aging process. By 18 months of age, cardiac remodeling deteriorated to congestive heart failure in transgenic mice. Collectively, these data suggest that HRC may be an integral regulatory protein involved in cardiac muscle SR Ca uptake and Ca homeostasis.
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Affiliation(s)
- Kimberly N Gregory
- Department of Pharmacology and Cell Biophysics, University of Cincinnati College of Medicine, OH 45267-0575, USA
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Rubio M, Bodi I, Fuller-Bicer GA, Hahn HS, Periasamy M, Schwartz A. Sarcoplasmic reticulum adenosine triphosphatase overexpression in the L-type Ca2+ channel mouse results in cardiomyopathy and Ca2+ -induced arrhythmogenesis. J Cardiovasc Pharmacol Ther 2006; 10:235-49. [PMID: 16382260 DOI: 10.1177/107424840501000404] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
BACKGROUND Overexpression of the L-type voltage-dependent calcium channel alpha(1C)-subunit (L-VDCC OE) in transgenic mice results in adaptive hypertrophy followed by a maladaptive phase associated with a decrease in sarcoplasmic reticulum adenosine triphosphatase (SERCA)2a expression at 8 to 10 months of age. Overexpressing SERCA to manipulate calcium (Ca(2+)) cycling and prevent pathologic phenotypes in some models of heart failure has been proven to be a promising genetic strategy. OBJECTIVE In this study we investigated whether genetic manipulation that increases Ca(2+) uptake into the sarcoplasmic reticulum by overexpressing SERCA1a (skeletal muscle specific) into the L-VDCC OE background could restore or further deteriorate Ca(2+) cycling, contractile dysfunction, and electrical remodeling in the heart failure phenotype. RESULTS We found that the survival rate of L-VDCC OE/SERCA1a OE double transgenic mice decreased by 50%. L-VDCC OE/SERCA1a OE mice displayed an accelerated phenotype of severe dilation of both ventricles associated with deteriorated left ventricular function. Voltage clamp experiments revealed enhanced increased inward Ca(2+) current density and decreased the transient outward potassium current. Action potential duration in double transgenic ventricular myocytes was prolonged, and isoproterenol induced early after depolarization. These mice demonstrated a high incidence of spontaneous left ventricular arrhythmia. Expression of the proarrhythmic signaling protein Ca(2+)/calmodulin-dependent kinase II (CaMKII) was increased while connexin43 expression was decreased, defining an important putative mechanism in the electrophysiologic disturbances and mortality. CONCLUSIONS Despite previous reports of improved cardiac function in heart failure models after SERCA intervention, our results advocate the need to elucidate the involvement of augmented Ca(2+) cycling in arrhythmogenesis.
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Affiliation(s)
- Marta Rubio
- Institute of Molecular Pharmacology and Biophysics, University of Cincinnati Medical Center, Cincinnati, OH 45267-0828, USA
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48
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Alarcón G, Valentín A, Watt C, Selway RP, Lacruz ME, Elwes RDC, Jarosz JM, Honavar M, Brunhuber F, Mullatti N, Bodi I, Salinas M, Binnie CD, Polkey CE. Is it worth pursuing surgery for epilepsy in patients with normal neuroimaging? J Neurol Neurosurg Psychiatry 2006; 77:474-80. [PMID: 16543525 PMCID: PMC2077525 DOI: 10.1136/jnnp.2005.077289] [Citation(s) in RCA: 82] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
OBJECTIVE To determine whether it is worth pursuing surgery for the treatment of epilepsy in patients with normal neuroimaging. METHODS Two patient populations were studied: (1) 136 consecutive patients who were surgically treated; (2) 105 consecutive patients assessed with chronically implanted intracranial electrodes within the same period. Sixty patients belonged to both groups, and included all 21 patients who had normal neuroimaging. RESULTS There were no differences in the proportion of patients with favourable outcome between those with normal and those with abnormal neuroimaging, irrespective of whether intracranial recordings were required. Among the 19 operated patients with normal neuroimaging, 74% had a favourable outcome (Engel's seizure outcome grades I and II), and among the 93 patients with abnormal neuroimaging, 73% had favourable outcome (p = 0.96). In patients with temporal resections, 92% of the 13 patients with normal neuroimaging had a favourable outcome, whereas among the 70 patients with abnormal neuroimaging, 80% had a favourable outcome (p = 0.44). In patients with extratemporal resections, two of the six patients with normal neuroimaging had a favourable outcome, while 12 of the 23 patients with abnormal neuroimaging had a favourable outcome (p = 0.65). Among the 105 patients studied with intracranial electrodes, five suffered transitory deficits as a result of implantation, and two suffered permanent deficits (one hemiplegia caused by haematoma and one mild dysphasia resulting from haemorrhage). CONCLUSIONS It is worth pursuing surgery in patients with normal neuroimaging because it results in good seizure control and the incidence of permanent deficits associated with intracranial studies is low.
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Affiliation(s)
- G Alarcón
- Department of Clinical Neurophysiology, King's College Hospital, Denmark Hill, London SE5 9RS, UK.
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Xu J, Gong NL, Bodi I, Aronow BJ, Backx PH, Molkentin JD. Myocyte enhancer factors 2A and 2C induce dilated cardiomyopathy in transgenic mice. J Biol Chem 2006; 281:9152-62. [PMID: 16469744 DOI: 10.1074/jbc.m510217200] [Citation(s) in RCA: 150] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Cardiac hypertrophy and dilation are mediated by neuroendocrine factors and/or mitogens as well as through internal stretch- and stress-sensitive signaling pathways, which in turn transduce alterations in cardiac gene expression through specific signaling pathways. The transcription factor family known as myocyte enhancer factor 2 (MEF2) has been implicated as a signal-responsive mediator of the cardiac transcriptional program. For example, known hypertrophic signaling pathways that utilize calcineurin, calmodulin-dependent protein kinase, and MAPKs can each affect MEF2 activity. Here we demonstrate that MEF2 transcription factors induced dilated cardiomyopathy and lengthening of myocytes. Specifically, multiple transgenic mouse lines with cardiac-specific overexpression of MEF2A or MEF2C presented with cardiomyopathy at base line or were predisposed to more fulminant disease following pressure overload stimulation. The cardiomyopathic response associated with MEF2A and MEF2C was not further altered by activated calcineurin, suggesting that MEF2 functions independently of calcineurin in this response. In cultured cardiomyocytes, MEF2A, MEF2C, and MEF2-VP16 overexpression induced sarcomeric disorganization and focal elongation. Mechanistically, MEF2A and MEF2C each programmed similar profiles of altered gene expression in the heart that included extracellular matrix remodeling, ion handling, and metabolic genes. Indeed, adenoviral transfection of cultured cardiomyocytes with MEF2A or of myocytes from the hearts of MEF2A transgenic adult mice showed reduced transient outward K(+) currents, consistent with the alterations in gene expression observed in transgenic mice and partially suggesting a proximal mechanism underlying MEF2-dependent cardiomyopathy.
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Affiliation(s)
- Jian Xu
- Departments of Pharmacology and Pediatrics, Cincinnati Children's Hospital Medical Center, University of Cincinnati, Cincinnati, Ohio 45229, USA
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Abstract
Sydney Ringer would be overwhelmed today by the implications of his simple experiment performed over 120 years ago showing that the heart would not beat in the absence of Ca2+. Fascination with the role of Ca2+ has proliferated into all aspects of our understanding of normal cardiac function and the progression of heart disease, including induction of cardiac hypertrophy, heart failure, and sudden death. This review examines the role of Ca2+ and the L-type voltage-dependent Ca2+ channels in cardiac disease.
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Affiliation(s)
- Ilona Bodi
- Institute of Molecular Pharmacology and Biophysics, University of Cincinnati College of Medicine, Ohio 45267, USA
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