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Rahm AK, Wieder T, Gramlich D, Müller ME, Wunsch MN, El Tahry FA, Heimberger T, Sandke S, Weis T, Most P, Katus HA, Thomas D, Lugenbiel P. Differential regulation of K Ca 2.1 (KCNN1) K + channel expression by histone deacetylases in atrial fibrillation with concomitant heart failure. Physiol Rep 2021; 9:e14835. [PMID: 34111326 PMCID: PMC8191401 DOI: 10.14814/phy2.14835] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [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: 01/19/2021] [Revised: 03/17/2021] [Accepted: 03/18/2021] [Indexed: 01/12/2023] Open
Abstract
Atrial fibrillation (AF) with concomitant heart failure (HF) poses a significant therapeutic challenge. Mechanism‐based approaches may optimize AF therapy. Small‐conductance, calcium‐activated K+ (KCa, KCNN) channels contribute to cardiac action potential repolarization. KCNN1 exhibits predominant atrial expression and is downregulated in chronic AF patients with preserved cardiac function. Epigenetic regulation is suggested by AF suppression following histone deacetylase (HDAC) inhibition. We hypothesized that HDAC‐dependent KCNN1 remodeling contributes to arrhythmogenesis in AF complicated by HF. The aim of this study was to assess KCNN1 and HDAC1–7 and 9 transcript levels in AF/HF patients and in a pig model of atrial tachypacing‐induced AF with reduced left ventricular function. In HL‐1 atrial myocytes, tachypacing and anti‐Hdac siRNAs were employed to investigate effects on Kcnn1 mRNA levels. KCNN1 expression displayed side‐specific remodeling in AF/HF patients with upregulation in left and suppression in right atrium. In pigs, KCNN1 remodeling showed intermediate phenotypes. HDAC levels were differentially altered in humans and pigs, reflecting highly variable epigenetic regulation. Tachypacing recapitulated downregulation of Hdacs1, 3, 4, 6, and 7 with a tendency towards reduced Kcnn1 levels in vitro, indicating that atrial high rates induce remodeling. Finally, Kcnn1 expression was decreased by knockdown of Hdacs2, 3, 6, and 7 and enhanced by genetic Hdac9 inactivation, while anti‐Hdac1, 4, and 5 siRNAs did not affect Kcnn1 transcript levels. In conclusion, KCNN1 and HDAC expression is differentially remodeled in AF complicated by HF. Direct regulation of KCNN1 by HDACs in atrial myocytes provides a basis for mechanism‐based antiarrhythmic therapy.
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Affiliation(s)
- Ann-Kathrin Rahm
- Department of Cardiology, Medical University Hospital Heidelberg, Heidelberg, Germany.,HCR (Heidelberg Center for Heart Rhythm Disorders), University Hospital Heidelberg, Heidelberg, Germany.,DZHK (German Centre for Cardiovascular Research), partner site Heidelberg/Mannheim, University of Heidelberg, Heidelberg, Germany
| | - Teresa Wieder
- Department of Cardiology, Medical University Hospital Heidelberg, Heidelberg, Germany.,HCR (Heidelberg Center for Heart Rhythm Disorders), University Hospital Heidelberg, Heidelberg, Germany
| | - Dominik Gramlich
- Department of Cardiology, Medical University Hospital Heidelberg, Heidelberg, Germany.,HCR (Heidelberg Center for Heart Rhythm Disorders), University Hospital Heidelberg, Heidelberg, Germany.,DZHK (German Centre for Cardiovascular Research), partner site Heidelberg/Mannheim, University of Heidelberg, Heidelberg, Germany
| | - Mara Elena Müller
- Department of Cardiology, Medical University Hospital Heidelberg, Heidelberg, Germany.,HCR (Heidelberg Center for Heart Rhythm Disorders), University Hospital Heidelberg, Heidelberg, Germany.,DZHK (German Centre for Cardiovascular Research), partner site Heidelberg/Mannheim, University of Heidelberg, Heidelberg, Germany
| | - Maximilian N Wunsch
- Department of Cardiology, Medical University Hospital Heidelberg, Heidelberg, Germany.,HCR (Heidelberg Center for Heart Rhythm Disorders), University Hospital Heidelberg, Heidelberg, Germany.,DZHK (German Centre for Cardiovascular Research), partner site Heidelberg/Mannheim, University of Heidelberg, Heidelberg, Germany
| | - Fadwa A El Tahry
- Department of Cardiology, Medical University Hospital Heidelberg, Heidelberg, Germany.,DZHK (German Centre for Cardiovascular Research), partner site Heidelberg/Mannheim, University of Heidelberg, Heidelberg, Germany
| | - Tanja Heimberger
- Department of Cardiology, Medical University Hospital Heidelberg, Heidelberg, Germany.,DZHK (German Centre for Cardiovascular Research), partner site Heidelberg/Mannheim, University of Heidelberg, Heidelberg, Germany
| | - Steffi Sandke
- Department of Cardiology, Medical University Hospital Heidelberg, Heidelberg, Germany.,DZHK (German Centre for Cardiovascular Research), partner site Heidelberg/Mannheim, University of Heidelberg, Heidelberg, Germany
| | - Tanja Weis
- Department of Cardiology, Medical University Hospital Heidelberg, Heidelberg, Germany.,DZHK (German Centre for Cardiovascular Research), partner site Heidelberg/Mannheim, University of Heidelberg, Heidelberg, Germany
| | - Patrick Most
- Department of Cardiology, Medical University Hospital Heidelberg, Heidelberg, Germany.,HCR (Heidelberg Center for Heart Rhythm Disorders), University Hospital Heidelberg, Heidelberg, Germany
| | - Hugo A Katus
- Department of Cardiology, Medical University Hospital Heidelberg, Heidelberg, Germany.,HCR (Heidelberg Center for Heart Rhythm Disorders), University Hospital Heidelberg, Heidelberg, Germany.,DZHK (German Centre for Cardiovascular Research), partner site Heidelberg/Mannheim, University of Heidelberg, Heidelberg, Germany
| | - Dierk Thomas
- Department of Cardiology, Medical University Hospital Heidelberg, Heidelberg, Germany.,HCR (Heidelberg Center for Heart Rhythm Disorders), University Hospital Heidelberg, Heidelberg, Germany.,DZHK (German Centre for Cardiovascular Research), partner site Heidelberg/Mannheim, University of Heidelberg, Heidelberg, Germany
| | - Patrick Lugenbiel
- Department of Cardiology, Medical University Hospital Heidelberg, Heidelberg, Germany.,HCR (Heidelberg Center for Heart Rhythm Disorders), University Hospital Heidelberg, Heidelberg, Germany.,DZHK (German Centre for Cardiovascular Research), partner site Heidelberg/Mannheim, University of Heidelberg, Heidelberg, Germany
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Rahm AK, Gramlich D, Wieder T, Müller ME, Schoeffel A, El Tahry FA, Most P, Heimberger T, Sandke S, Weis T, Ullrich ND, Korff T, Lugenbiel P, Katus HA, Thomas D. Trigger-Specific Remodeling of K Ca2 Potassium Channels in Models of Atrial Fibrillation. Pharmgenomics Pers Med 2021; 14:579-590. [PMID: 34045886 PMCID: PMC8144362 DOI: 10.2147/pgpm.s290291] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Accepted: 04/06/2021] [Indexed: 11/23/2022] Open
Abstract
AIM Effective antiarrhythmic treatment of atrial fibrillation (AF) constitutes a major challenge, in particular, when concomitant heart failure (HF) is present. HF-associated atrial arrhythmogenesis is distinctly characterized by prolonged atrial refractoriness. Small-conductance, calcium-activated K+ (KCa, SK, KCNN) channels contribute to cardiac action potential repolarization and are implicated in AF susceptibility and therapy. The mechanistic impact of AF/HF-related triggers on atrial KCa channels is not known. We hypothesized that tachycardia, stretch, β-adrenergic stimulation, and hypoxia differentially determine KCa2.1-2.3 channel remodeling in atrial cells. METHODS KCNN1-3 transcript levels were assessed in AF/HF patients and in a pig model of atrial tachypacing-induced AF with reduced left ventricular function. HL-1 atrial myocytes were subjected to proarrhythmic triggers to investigate the effects on Kcnn mRNA and KCa channel protein. RESULTS Atrial KCNN1-3 expression was reduced in AF/HF patients. KCNN2 and KCNN3 suppression was recapitulated in the corresponding pig model. In contrast to human AF, KCNN1 remained unchanged in pigs. Channel- and stressor-specific remodeling was revealed in vitro. Lower expression levels of KCNN1/KCa2.1 were linked to stretch and β-adrenergic stimulation. Furthermore, KCNN3/KCa2.3 expression was suppressed upon tachypacing and hypoxia. Finally, KCNN2/KCa2.2 abundance was specifically enhanced by hypoxia. CONCLUSION Reduction of KCa2.1-2.3 channel expression might contribute to the action potential prolongation in AF complicated by HF. Subtype-specific KCa2 channel remodeling induced by tachypacing, stretch, β-adrenergic stimulation, or hypoxia is expected to differentially determine atrial remodeling, depending on patient-specific activation of each triggering factor. Stressor-dependent KCa2 regulation in atrial myocytes provides a starting point for mechanism-based antiarrhythmic therapy.
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Affiliation(s)
- Ann-Kathrin Rahm
- Department of Cardiology, Medical University Hospital Heidelberg, Heidelberg, 69120, Germany
- HCR (Heidelberg Center for Heart Rhythm Disorders), University Hospital Heidelberg, Heidelberg, 69120, Germany
- DZHK (German Centre for Cardiovascular Research), Partner Site Heidelberg/Mannheim, University of Heidelberg, Heidelberg, 69120, Germany
| | - Dominik Gramlich
- Department of Cardiology, Medical University Hospital Heidelberg, Heidelberg, 69120, Germany
- HCR (Heidelberg Center for Heart Rhythm Disorders), University Hospital Heidelberg, Heidelberg, 69120, Germany
- DZHK (German Centre for Cardiovascular Research), Partner Site Heidelberg/Mannheim, University of Heidelberg, Heidelberg, 69120, Germany
| | - Teresa Wieder
- Department of Cardiology, Medical University Hospital Heidelberg, Heidelberg, 69120, Germany
- HCR (Heidelberg Center for Heart Rhythm Disorders), University Hospital Heidelberg, Heidelberg, 69120, Germany
| | - Mara Elena Müller
- Department of Cardiology, Medical University Hospital Heidelberg, Heidelberg, 69120, Germany
- HCR (Heidelberg Center for Heart Rhythm Disorders), University Hospital Heidelberg, Heidelberg, 69120, Germany
- DZHK (German Centre for Cardiovascular Research), Partner Site Heidelberg/Mannheim, University of Heidelberg, Heidelberg, 69120, Germany
| | - Axel Schoeffel
- Department of Cardiology, Medical University Hospital Heidelberg, Heidelberg, 69120, Germany
- HCR (Heidelberg Center for Heart Rhythm Disorders), University Hospital Heidelberg, Heidelberg, 69120, Germany
| | - Fadwa A El Tahry
- Department of Cardiology, Medical University Hospital Heidelberg, Heidelberg, 69120, Germany
| | - Patrick Most
- Department of Cardiology, Medical University Hospital Heidelberg, Heidelberg, 69120, Germany
- HCR (Heidelberg Center for Heart Rhythm Disorders), University Hospital Heidelberg, Heidelberg, 69120, Germany
| | - Tanja Heimberger
- Department of Cardiology, Medical University Hospital Heidelberg, Heidelberg, 69120, Germany
- DZHK (German Centre for Cardiovascular Research), Partner Site Heidelberg/Mannheim, University of Heidelberg, Heidelberg, 69120, Germany
| | - Steffi Sandke
- Department of Cardiology, Medical University Hospital Heidelberg, Heidelberg, 69120, Germany
- DZHK (German Centre for Cardiovascular Research), Partner Site Heidelberg/Mannheim, University of Heidelberg, Heidelberg, 69120, Germany
| | - Tanja Weis
- Department of Cardiology, Medical University Hospital Heidelberg, Heidelberg, 69120, Germany
- DZHK (German Centre for Cardiovascular Research), Partner Site Heidelberg/Mannheim, University of Heidelberg, Heidelberg, 69120, Germany
| | - Nina D Ullrich
- Institute of Physiology and Pathophysiology, Department of Cardiovascular Physiology, Heidelberg University, Heidelberg, 69120, Germany
| | - Thomas Korff
- Institute of Physiology and Pathophysiology, Department of Cardiovascular Physiology, Heidelberg University, Heidelberg, 69120, Germany
- European Center for Angioscience (ECAS), Medical Faculty Mannheim, Heidelberg University, Mannheim, 68167, Germany
| | - Patrick Lugenbiel
- Department of Cardiology, Medical University Hospital Heidelberg, Heidelberg, 69120, Germany
- HCR (Heidelberg Center for Heart Rhythm Disorders), University Hospital Heidelberg, Heidelberg, 69120, Germany
- DZHK (German Centre for Cardiovascular Research), Partner Site Heidelberg/Mannheim, University of Heidelberg, Heidelberg, 69120, Germany
| | - Hugo A Katus
- Department of Cardiology, Medical University Hospital Heidelberg, Heidelberg, 69120, Germany
- HCR (Heidelberg Center for Heart Rhythm Disorders), University Hospital Heidelberg, Heidelberg, 69120, Germany
- DZHK (German Centre for Cardiovascular Research), Partner Site Heidelberg/Mannheim, University of Heidelberg, Heidelberg, 69120, Germany
| | - Dierk Thomas
- Department of Cardiology, Medical University Hospital Heidelberg, Heidelberg, 69120, Germany
- HCR (Heidelberg Center for Heart Rhythm Disorders), University Hospital Heidelberg, Heidelberg, 69120, Germany
- DZHK (German Centre for Cardiovascular Research), Partner Site Heidelberg/Mannheim, University of Heidelberg, Heidelberg, 69120, Germany
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Lugenbiel P, Govorov K, Syren P, Rahm AK, Wieder T, Wunsch M, Weiberg N, Manolova E, Gramlich D, Rivinius R, Finke D, Lehmann LH, Schweizer PA, Frank D, El Tahry FA, Bruehl C, Heimberger T, Sandke S, Weis T, Most P, Schmack B, Ruhparwar A, Karck M, Frey N, Katus HA, Thomas D. Epigenetic regulation of cardiac electrophysiology in atrial fibrillation: HDAC2 determines action potential duration and suppresses NRSF in cardiomyocytes. Basic Res Cardiol 2021; 116:13. [PMID: 33630168 DOI: 10.1007/s00395-021-00855-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [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] [Received: 11/23/2020] [Accepted: 02/18/2021] [Indexed: 01/03/2023]
Abstract
Atrial fibrillation (AF) is associated with electrical remodeling, leading to cellular electrophysiological dysfunction and arrhythmia perpetuation. Emerging evidence suggests a key role for epigenetic mechanisms in the regulation of ion channel expression. Histone deacetylases (HDACs) control gene expression through deacetylation of histone proteins. We hypothesized that class I HDACs in complex with neuron-restrictive silencer factor (NRSF) determine atrial K+ channel expression. AF was characterized by reduced atrial HDAC2 mRNA levels and upregulation of NRSF in humans and in a pig model, with regional differences between right and left atrium. In vitro studies revealed inverse regulation of Hdac2 and Nrsf in HL-1 atrial myocytes. A direct association of HDAC2 with active regulatory elements of cardiac K+ channels was revealed by chromatin immunoprecipitation. Specific knock-down of Hdac2 and Nrsf induced alterations of K+ channel expression. Hdac2 knock-down resulted in prolongation of action potential duration (APD) in neonatal rat cardiomyocytes, whereas inactivation of Nrsf induced APD shortening. Potential AF-related triggers were recapitulated by experimental tachypacing and mechanical stretch, respectively, and exerted differential effects on the expression of class I HDACs and K+ channels in cardiomyocytes. In conclusion, HDAC2 and NRSF contribute to AF-associated remodeling of APD and K+ channel expression in cardiomyocytes via direct interaction with regulatory chromatin regions. Specific modulation of these factors may provide a starting point for the development of more individualized treatment options for atrial fibrillation.
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Affiliation(s)
- Patrick Lugenbiel
- Department of Cardiology, University of Heidelberg, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany
- HCR (Heidelberg Center for Heart Rhythm Disorders), Heidelberg, Germany
| | - Katharina Govorov
- Department of Cardiology, University of Heidelberg, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany
- HCR (Heidelberg Center for Heart Rhythm Disorders), Heidelberg, Germany
| | - Pascal Syren
- Department of Cardiology, University of Heidelberg, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany
- HCR (Heidelberg Center for Heart Rhythm Disorders), Heidelberg, Germany
| | - Ann-Kathrin Rahm
- Department of Cardiology, University of Heidelberg, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany
- HCR (Heidelberg Center for Heart Rhythm Disorders), Heidelberg, Germany
- DZHK (German Centre for Cardiovascular Research), partner site Heidelberg/Mannheim, University of Heidelberg, Heidelberg, Germany
| | - Teresa Wieder
- Department of Cardiology, University of Heidelberg, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany
- HCR (Heidelberg Center for Heart Rhythm Disorders), Heidelberg, Germany
| | - Maximilian Wunsch
- Department of Cardiology, University of Heidelberg, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany
- HCR (Heidelberg Center for Heart Rhythm Disorders), Heidelberg, Germany
- DZHK (German Centre for Cardiovascular Research), partner site Heidelberg/Mannheim, University of Heidelberg, Heidelberg, Germany
| | - Nadine Weiberg
- Department of Cardiology, University of Heidelberg, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany
- HCR (Heidelberg Center for Heart Rhythm Disorders), Heidelberg, Germany
| | - Emili Manolova
- Department of Cardiology, University of Heidelberg, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany
- HCR (Heidelberg Center for Heart Rhythm Disorders), Heidelberg, Germany
| | - Dominik Gramlich
- Department of Cardiology, University of Heidelberg, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany
- HCR (Heidelberg Center for Heart Rhythm Disorders), Heidelberg, Germany
- DZHK (German Centre for Cardiovascular Research), partner site Heidelberg/Mannheim, University of Heidelberg, Heidelberg, Germany
| | - Rasmus Rivinius
- Department of Cardiology, University of Heidelberg, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany
- HCR (Heidelberg Center for Heart Rhythm Disorders), Heidelberg, Germany
- DZHK (German Centre for Cardiovascular Research), partner site Heidelberg/Mannheim, University of Heidelberg, Heidelberg, Germany
| | - Daniel Finke
- Department of Cardiology, University of Heidelberg, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany
- HCR (Heidelberg Center for Heart Rhythm Disorders), Heidelberg, Germany
- Department of Molecular Cardiology and Epigenetics, University Hospital Heidelberg, Heidelberg, Germany
| | - Lorenz H Lehmann
- Department of Cardiology, University of Heidelberg, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany
- HCR (Heidelberg Center for Heart Rhythm Disorders), Heidelberg, Germany
- Department of Molecular Cardiology and Epigenetics, University Hospital Heidelberg, Heidelberg, Germany
| | - Patrick A Schweizer
- Department of Cardiology, University of Heidelberg, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany
- HCR (Heidelberg Center for Heart Rhythm Disorders), Heidelberg, Germany
- DZHK (German Centre for Cardiovascular Research), partner site Heidelberg/Mannheim, University of Heidelberg, Heidelberg, Germany
| | - Derk Frank
- Department of Internal Medicine III, Cardiology and Angiology, University Medical Center Schleswig-Holstein, Kiel, Germany
- DZHK (German Centre for Cardiovascular Research), partner site Hamburg/Kiel/Lübeck, University Medical Center Schleswig-Holstein, Kiel, Germany
| | - Fadwa A El Tahry
- Department of Cardiology, University of Heidelberg, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany
- DZHK (German Centre for Cardiovascular Research), partner site Heidelberg/Mannheim, University of Heidelberg, Heidelberg, Germany
| | - Claus Bruehl
- Institute for Physiology and Pathophysiology, Heidelberg, Germany
| | - Tanja Heimberger
- Department of Cardiology, University of Heidelberg, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany
- DZHK (German Centre for Cardiovascular Research), partner site Heidelberg/Mannheim, University of Heidelberg, Heidelberg, Germany
| | - Steffi Sandke
- Department of Cardiology, University of Heidelberg, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany
- DZHK (German Centre for Cardiovascular Research), partner site Heidelberg/Mannheim, University of Heidelberg, Heidelberg, Germany
| | - Tanja Weis
- Department of Cardiology, University of Heidelberg, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany
- DZHK (German Centre for Cardiovascular Research), partner site Heidelberg/Mannheim, University of Heidelberg, Heidelberg, Germany
| | - Patrick Most
- Department of Cardiology, University of Heidelberg, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany
- DZHK (German Centre for Cardiovascular Research), partner site Heidelberg/Mannheim, University of Heidelberg, Heidelberg, Germany
| | - Bastian Schmack
- Department of Cardiac Surgery, University Hospital Heidelberg, Heidelberg, Germany
| | - Arjang Ruhparwar
- Department of Cardiac Surgery, University Hospital Heidelberg, Heidelberg, Germany
| | - Matthias Karck
- Department of Cardiac Surgery, University Hospital Heidelberg, Heidelberg, Germany
| | - Norbert Frey
- Department of Cardiology, University of Heidelberg, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany
- HCR (Heidelberg Center for Heart Rhythm Disorders), Heidelberg, Germany
- DZHK (German Centre for Cardiovascular Research), partner site Heidelberg/Mannheim, University of Heidelberg, Heidelberg, Germany
- Department of Internal Medicine III, Cardiology and Angiology, University Medical Center Schleswig-Holstein, Kiel, Germany
- DZHK (German Centre for Cardiovascular Research), partner site Hamburg/Kiel/Lübeck, University Medical Center Schleswig-Holstein, Kiel, Germany
| | - Hugo A Katus
- Department of Cardiology, University of Heidelberg, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany
- HCR (Heidelberg Center for Heart Rhythm Disorders), Heidelberg, Germany
- DZHK (German Centre for Cardiovascular Research), partner site Heidelberg/Mannheim, University of Heidelberg, Heidelberg, Germany
| | - Dierk Thomas
- Department of Cardiology, University of Heidelberg, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany.
- HCR (Heidelberg Center for Heart Rhythm Disorders), Heidelberg, Germany.
- DZHK (German Centre for Cardiovascular Research), partner site Heidelberg/Mannheim, University of Heidelberg, Heidelberg, Germany.
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Rahm AK, Wieder T, Gramlich D, Müller ME, Wunsch MN, El Tahry FA, Heimberger T, Weis T, Most P, Katus HA, Thomas D, Lugenbiel P. HDAC2-dependent remodeling of K Ca2.2 (KCNN2) and K Ca2.3 (KCNN3) K + channels in atrial fibrillation with concomitant heart failure. Life Sci 2020; 266:118892. [PMID: 33310041 DOI: 10.1016/j.lfs.2020.118892] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Revised: 11/30/2020] [Accepted: 12/07/2020] [Indexed: 12/16/2022]
Abstract
AIMS Atrial fibrillation (AF) with concomitant heart failure (HF) is associated with prolonged atrial refractoriness. Small-conductance, calcium-activated K+ (KCa, KCNN) channels promote action potential (AP) repolarization. KCNN2 and KCNN3 variants are associated with AF risk. In addition, histone deacetylase (HDAC)-related epigenetic mechanisms have been implicated in AP regulation. We hypothesized that HDAC2-dependent remodeling of KCNN2 and KCNN3 expression contributes to atrial arrhythmogenesis in AF complicated by HF. The objectives were to assess HDAC2 and KCNN2/3 transcript levels in AF/HF patients and in a pig model, and to investigate cellular epigenetic effects of HDAC2 inactivation on KCNN expression. MATERIALS AND METHODS HDAC2 and KCNN2/3 transcript levels were quantified in patients with AF and HF, and in a porcine model of atrial tachypacing-induced AF and reduced left ventricular function. Tachypacing and anti-Hdac2 siRNA treatment were employed in HL-1 atrial myocytes to study effects on KCNN2/3 mRNA and KCa protein abundance. KEY FINDINGS Atrial KCNN2 and KCNN3 expression was reduced in AF/HF patients and in a corresponding pig model. HDAC2 displayed significant downregulation in humans and a tendency towards reduced expression in right atrial tissue of pigs. Tachypacing recapitulated downregulation of Kcnn2/KCa2.2, Kcnn3/KCa2.3 and Hdac2/HDAC2, indicating that high atrial rates trigger epigenetic remodeling mechanisms. Finally, knock-down of Hdac2 in vitro reduced Kcnn3/KCa2.3 expression. SIGNIFICANCE KCNN2/3 and HDAC2 expression is suppressed in AF complicated by HF. Hdac2 directly regulates Kcnn3 mRNA levels in atrial cells. The mechanistic and therapeutic significance of epigenetic electrophysiological effects in AF requires further validation.
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Affiliation(s)
- Ann-Kathrin Rahm
- Department of Cardiology, Medical University Hospital Heidelberg, Im Neuenheimer Feld 410, 69120 Heidelberg, Germany; HCR (Heidelberg Center for Heart Rhythm Disorders), University Hospital Heidelberg, Im Neuenheimer Feld 410, 69120 Heidelberg, Germany; DZHK (German Centre for Cardiovascular Research), partner site Heidelberg/Mannheim, University of Heidelberg, Im Neuenheimer Feld 410, 69120 Heidelberg, Germany
| | - Teresa Wieder
- Department of Cardiology, Medical University Hospital Heidelberg, Im Neuenheimer Feld 410, 69120 Heidelberg, Germany; HCR (Heidelberg Center for Heart Rhythm Disorders), University Hospital Heidelberg, Im Neuenheimer Feld 410, 69120 Heidelberg, Germany
| | - Dominik Gramlich
- Department of Cardiology, Medical University Hospital Heidelberg, Im Neuenheimer Feld 410, 69120 Heidelberg, Germany; HCR (Heidelberg Center for Heart Rhythm Disorders), University Hospital Heidelberg, Im Neuenheimer Feld 410, 69120 Heidelberg, Germany; DZHK (German Centre for Cardiovascular Research), partner site Heidelberg/Mannheim, University of Heidelberg, Im Neuenheimer Feld 410, 69120 Heidelberg, Germany
| | - Mara Elena Müller
- Department of Cardiology, Medical University Hospital Heidelberg, Im Neuenheimer Feld 410, 69120 Heidelberg, Germany; HCR (Heidelberg Center for Heart Rhythm Disorders), University Hospital Heidelberg, Im Neuenheimer Feld 410, 69120 Heidelberg, Germany; DZHK (German Centre for Cardiovascular Research), partner site Heidelberg/Mannheim, University of Heidelberg, Im Neuenheimer Feld 410, 69120 Heidelberg, Germany
| | - Maximilian N Wunsch
- Department of Cardiology, Medical University Hospital Heidelberg, Im Neuenheimer Feld 410, 69120 Heidelberg, Germany; HCR (Heidelberg Center for Heart Rhythm Disorders), University Hospital Heidelberg, Im Neuenheimer Feld 410, 69120 Heidelberg, Germany; DZHK (German Centre for Cardiovascular Research), partner site Heidelberg/Mannheim, University of Heidelberg, Im Neuenheimer Feld 410, 69120 Heidelberg, Germany
| | - Fadwa A El Tahry
- Department of Cardiology, Medical University Hospital Heidelberg, Im Neuenheimer Feld 410, 69120 Heidelberg, Germany; DZHK (German Centre for Cardiovascular Research), partner site Heidelberg/Mannheim, University of Heidelberg, Im Neuenheimer Feld 410, 69120 Heidelberg, Germany
| | - Tanja Heimberger
- Department of Cardiology, Medical University Hospital Heidelberg, Im Neuenheimer Feld 410, 69120 Heidelberg, Germany; DZHK (German Centre for Cardiovascular Research), partner site Heidelberg/Mannheim, University of Heidelberg, Im Neuenheimer Feld 410, 69120 Heidelberg, Germany
| | - Tanja Weis
- Department of Cardiology, Medical University Hospital Heidelberg, Im Neuenheimer Feld 410, 69120 Heidelberg, Germany; DZHK (German Centre for Cardiovascular Research), partner site Heidelberg/Mannheim, University of Heidelberg, Im Neuenheimer Feld 410, 69120 Heidelberg, Germany
| | - Patrick Most
- Department of Cardiology, Medical University Hospital Heidelberg, Im Neuenheimer Feld 410, 69120 Heidelberg, Germany; DZHK (German Centre for Cardiovascular Research), partner site Heidelberg/Mannheim, University of Heidelberg, Im Neuenheimer Feld 410, 69120 Heidelberg, Germany
| | - Hugo A Katus
- Department of Cardiology, Medical University Hospital Heidelberg, Im Neuenheimer Feld 410, 69120 Heidelberg, Germany; HCR (Heidelberg Center for Heart Rhythm Disorders), University Hospital Heidelberg, Im Neuenheimer Feld 410, 69120 Heidelberg, Germany; DZHK (German Centre for Cardiovascular Research), partner site Heidelberg/Mannheim, University of Heidelberg, Im Neuenheimer Feld 410, 69120 Heidelberg, Germany
| | - Dierk Thomas
- Department of Cardiology, Medical University Hospital Heidelberg, Im Neuenheimer Feld 410, 69120 Heidelberg, Germany; HCR (Heidelberg Center for Heart Rhythm Disorders), University Hospital Heidelberg, Im Neuenheimer Feld 410, 69120 Heidelberg, Germany; DZHK (German Centre for Cardiovascular Research), partner site Heidelberg/Mannheim, University of Heidelberg, Im Neuenheimer Feld 410, 69120 Heidelberg, Germany.
| | - Patrick Lugenbiel
- Department of Cardiology, Medical University Hospital Heidelberg, Im Neuenheimer Feld 410, 69120 Heidelberg, Germany; HCR (Heidelberg Center for Heart Rhythm Disorders), University Hospital Heidelberg, Im Neuenheimer Feld 410, 69120 Heidelberg, Germany; DZHK (German Centre for Cardiovascular Research), partner site Heidelberg/Mannheim, University of Heidelberg, Im Neuenheimer Feld 410, 69120 Heidelberg, Germany
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Rahm AK, Müller ME, Gramlich D, Lugenbiel P, Uludag E, Rivinius R, Ullrich ND, Schmack B, Ruhparwar A, Heimberger T, Weis T, Karck M, Katus HA, Thomas D. Inhibition of cardiac K v4.3 (I to) channel isoforms by class I antiarrhythmic drugs lidocaine and mexiletine. Eur J Pharmacol 2020; 880:173159. [PMID: 32360350 DOI: 10.1016/j.ejphar.2020.173159] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Revised: 04/01/2020] [Accepted: 04/23/2020] [Indexed: 12/29/2022]
Abstract
Transient outward K+ current, Ito, contributes to cardiac action potential generation and is primarily carried by Kv4.3 (KCND3) channels. Two Kv4.3 isoforms are expressed in human ventricle and show differential remodeling in heart failure (HF). Lidocaine and mexiletine may be applied in selected patients to suppress ventricular arrhythmias, without effects on sudden cardiac death or mortality. Isoform-dependent effects of antiarrhythmic drugs on Kv4.3 channels and potential implications for remodeling-based antiarrhythmic management have not been assessed to date. We sought to test the hypotheses that Kv4.3 channels are targeted by lidocaine and mexiletine, and that drug sensitivity is determined in isoform-specific manner. Expression of KCND3 isoforms was quantified using qRT-PCR in left ventricular samples of patients with HF due to either ischemic or dilated cardiomyopathies (ICM or DCM). Long (Kv4.3-L) and short (Kv4.3-S) isoforms were heterologously expressed in Xenopus laevis oocytes to study drug sensitivity and effects on biophysical characteristics activation, deactivation, inactivation, and recovery from inactivation. In the present HF patient cohort KCND3 isoform expression did not differ between ICM and DCM. In vitro, lidocaine (IC50-Kv4.3-L: 0.8 mM; IC50-Kv4.3-S: 1.2 mM) and mexiletine (IC50-Kv4.3-L: 146 μM; IC50-Kv4.3-S: 160 μM) inhibited Kv4.3 with different sensitivity. Biophysical analyses identified accelerated and enhanced inactivation combined with delayed recovery from inactivation as primary biophysical mechanisms underlying Kv4.3 current reduction. In conclusion, differential effects on Kv4.3 isoforms extend the electropharmacological profile of lidocaine and mexiletine. Patient-specific remodeling of Kv4.3 isoforms may determine individual drug responses and requires consideration during clinical application of compounds targeting Kv4.3.
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Affiliation(s)
- Ann-Kathrin Rahm
- Department of Cardiology, Medical University Hospital Heidelberg, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany; HCR (Heidelberg Center for Heart Rhythm Disorders), University Hospital Heidelberg, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany; DZHK (German Centre for Cardiovascular Research), Partner Site Heidelberg/Mannheim, University of Heidelberg, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany
| | - Mara Elena Müller
- Department of Cardiology, Medical University Hospital Heidelberg, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany; HCR (Heidelberg Center for Heart Rhythm Disorders), University Hospital Heidelberg, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany; DZHK (German Centre for Cardiovascular Research), Partner Site Heidelberg/Mannheim, University of Heidelberg, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany
| | - Dominik Gramlich
- Department of Cardiology, Medical University Hospital Heidelberg, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany; HCR (Heidelberg Center for Heart Rhythm Disorders), University Hospital Heidelberg, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany; DZHK (German Centre for Cardiovascular Research), Partner Site Heidelberg/Mannheim, University of Heidelberg, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany
| | - Patrick Lugenbiel
- Department of Cardiology, Medical University Hospital Heidelberg, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany; HCR (Heidelberg Center for Heart Rhythm Disorders), University Hospital Heidelberg, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany; DZHK (German Centre for Cardiovascular Research), Partner Site Heidelberg/Mannheim, University of Heidelberg, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany
| | - Ecem Uludag
- Department of Cardiology, Medical University Hospital Heidelberg, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany; HCR (Heidelberg Center for Heart Rhythm Disorders), University Hospital Heidelberg, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany
| | - Rasmus Rivinius
- Department of Cardiology, Medical University Hospital Heidelberg, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany; HCR (Heidelberg Center for Heart Rhythm Disorders), University Hospital Heidelberg, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany; DZHK (German Centre for Cardiovascular Research), Partner Site Heidelberg/Mannheim, University of Heidelberg, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany
| | - Nina D Ullrich
- DZHK (German Centre for Cardiovascular Research), Partner Site Heidelberg/Mannheim, University of Heidelberg, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany; Institute of Physiology and Pathophysiology, Division of Cardiovascular Physiology, University of Heidelberg, Im Neuenheimer Feld 307, 69120, Heidelberg, Germany
| | - Bastian Schmack
- Department of Cardiac Surgery, University Hospital Heidelberg, Im Neuenheimer Feld 110, 69120, Heidelberg, Germany
| | - Arjang Ruhparwar
- Department of Cardiac Surgery, University Hospital Heidelberg, Im Neuenheimer Feld 110, 69120, Heidelberg, Germany
| | - Tanja Heimberger
- Department of Cardiology, Medical University Hospital Heidelberg, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany; DZHK (German Centre for Cardiovascular Research), Partner Site Heidelberg/Mannheim, University of Heidelberg, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany
| | - Tanja Weis
- Department of Cardiology, Medical University Hospital Heidelberg, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany; DZHK (German Centre for Cardiovascular Research), Partner Site Heidelberg/Mannheim, University of Heidelberg, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany
| | - Matthias Karck
- Department of Cardiac Surgery, University Hospital Heidelberg, Im Neuenheimer Feld 110, 69120, Heidelberg, Germany
| | - Hugo A Katus
- Department of Cardiology, Medical University Hospital Heidelberg, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany; HCR (Heidelberg Center for Heart Rhythm Disorders), University Hospital Heidelberg, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany; DZHK (German Centre for Cardiovascular Research), Partner Site Heidelberg/Mannheim, University of Heidelberg, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany
| | - Dierk Thomas
- Department of Cardiology, Medical University Hospital Heidelberg, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany; HCR (Heidelberg Center for Heart Rhythm Disorders), University Hospital Heidelberg, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany; DZHK (German Centre for Cardiovascular Research), Partner Site Heidelberg/Mannheim, University of Heidelberg, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany.
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Heimberger T, Andrulis M, Riedel S, Stühmer T, Schraud H, Beilhack A, Bumm T, Bogen B, Einsele H, Bargou RC, Chatterjee M. The heat shock transcription factor 1 as a potential new therapeutic target in multiple myeloma. Br J Haematol 2012; 160:465-76. [PMID: 23252346 DOI: 10.1111/bjh.12164] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2012] [Accepted: 09/27/2012] [Indexed: 01/03/2023]
Abstract
The heat shock transcription factor 1 (HSF1) has recently been reported to promote malignant transformation and growth. Here we provide experimental evidence for a role of HSF1 in the pathogenesis of multiple myeloma (MM). Immunohistochemical analyses revealed that HSF1 was overexpressed in half of the investigated MM samples, including virtually all cases with extramedullary manifestations or anaplastic morphology. HSF1 function was inhibited either by siRNA-mediated knockdown or pharmacologically through treatment with triptolide. Both approaches caused depletion of HSF1, lowered the constitutively high expression of a multitude of protective HSPs (such as HSP90, HSP70, HSP40 and HSP27), induced apoptosis in human MM cells in vitro, and strongly reduced MM tumour growth in vivo. Furthermore, we observed that treatment-induced upregulation of HSPs after proteasome or HSP90 inhibition was critically dependent on HSF1. Importantly, the apoptotic effects of the HSP90 inhibitor NVP-AUY922 or the proteasome inhibitor bortezomib were strongly enhanced in combination with triptolide, suggesting a salvage role of HSF1-dependent HSP induction in response to drug treatment. Collectively, our data indicate that inhibition of HSF1 affects multiple protective HSPs and might therefore represent a therapeutic strategy - in particular in combination with proteasome or HSP90 inhibitors.
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Affiliation(s)
- Tanja Heimberger
- Department of Internal Medicine II, Comprehensive Cancer Centre Mainfranken, University Hospital of Würzburg, Würzburg, Germany
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Chatterjee M, Andrulis M, Stühmer T, Müller E, Hofmann C, Steinbrunn T, Heimberger T, Schraud H, Kressmann S, Einsele H, Bargou RC. The PI3K/Akt signaling pathway regulates the expression of Hsp70, which critically contributes to Hsp90-chaperone function and tumor cell survival in multiple myeloma. Haematologica 2012; 98:1132-41. [PMID: 23065523 DOI: 10.3324/haematol.2012.066175] [Citation(s) in RCA: 114] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Despite therapeutic advances multiple myeloma remains largely incurable, and novel therapeutic concepts are needed. The Hsp90-chaperone is a reasonable therapeutic target, because it maintains oncogenic signaling of multiple deregulated pathways. However, in contrast to promising preclinical results, only limited clinical efficacy has been achieved through pharmacological Hsp90 inhibition. Because Hsp70 has been described to interact functionally with the Hsp90-complex, we analyzed the suitability of Hsp72 and Hsp73 as potential additional target sites. Expression of Hsp72 and Hsp73 in myeloma cells was analyzed by immunohistochemical staining and western blotting. Short interfering RNA-mediated knockdown or pharmacological inhibition of Hsp72 and Hsp73 was performed to evaluate the role of these proteins in myeloma cell survival and for Hsp90-chaperone function. Furthermore, the role of PI3K-dependent signaling in constitutive and inducible Hsp70 expression was investigated using short interfering RNA-mediated and pharmacological PI3K inhibition. Hsp72 and Hsp73 were frequently overexpressed in multiple myeloma. Knockdown of Hsp72 and/or Hsp73 or treatment with VER-155008 induced apoptosis of myeloma cells. Hsp72/Hsp73 inhibition decreased protein levels of Hsp90-chaperone clients affecting multiple oncogenic signaling pathways, and acted synergistically with the Hsp90 inhibitor NVP-AUY922 in the induction of death of myeloma cells. Inhibition of the PI3K/Akt/GSK3β pathway with short interfering RNA or PI103 decreased expression of the heat shock transcription factor 1 and down-regulated constitutive and inducible Hsp70 expression. Treatment of myeloma cells with a combination of NVP-AUY922 and PI103 resulted in additive to synergistic cytotoxicity. In conclusion, Hsp72 and Hsp73 sustain Hsp90-chaperone function and critically contribute to the survival of myeloma cells. Translation of Hsp70 inhibition into the clinic is therefore highly desirable. Treatment with PI3K inhibitors might represent an alternative therapeutic strategy to target Hsp70.
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Affiliation(s)
- Manik Chatterjee
- Department of Internal Medicine II, Division of Hematology, Comprehensive Cancer Center Mainfranken, University Hospital of Würzburg, Germany.
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Bringmann G, Rüdenauer S, Irmer A, Bruhn T, Brun R, Heimberger T, Stühmer T, Bargou R, Chatterjee M. Antitumoral and antileishmanial dioncoquinones and ancistroquinones from cell cultures of Triphyophyllum peltatum (Dioncophyllaceae) and Ancistrocladus abbreviatus (Ancistrocladaceae). Phytochemistry 2008; 69:2501-2509. [PMID: 18723197 DOI: 10.1016/j.phytochem.2008.06.019] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2008] [Revised: 06/18/2008] [Accepted: 06/20/2008] [Indexed: 05/26/2023]
Abstract
From the methanolic extracts of solid callus cultures from two species of the closely related palaeotropical plant families Dioncophyllaceae and Ancistrocladaceae seven new natural naphthoquinones were isolated, dioncoquinones A (4) and B (5) from Triphyophyllum peltatum, and ancistroquinones B (6), C (7), D (9), E (10), and F (12) from Ancistrocladus abbreviatus. Their structures were elucidated by spectroscopic, chemical, and computational methods. Furthermore, the already known naphthoquinones plumbagin (2), droserone (3), malvone A (8), and nepenthone A (11) were found in the extract of A. abbreviatus. Dioncoquinones A (4) and B (5) showed good - and specific - activity against Leishmania major, while they were not active against other protozoic parasites. Moreover, treatment with 4 and 5 strongly induced apoptosis in human tumor cells derived from two different B cell malignancies, B cell lymphoma and multiple myeloma, without any significant toxicity towards normal peripheral mononuclear blood cells.
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Affiliation(s)
- Gerhard Bringmann
- Institute of Organic Chemistry, University of Würzburg, Am Hubland, D-97074 Würzburg, Germany.
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9
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White DJ, Talarico J, Chang HG, Birkhead GS, Heimberger T, Morse DL. Human babesiosis in New York State: Review of 139 hospitalized cases and analysis of prognostic factors. Arch Intern Med 1998; 158:2149-54. [PMID: 9801183 DOI: 10.1001/archinte.158.19.2149] [Citation(s) in RCA: 173] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
BACKGROUND Babesiosis infections are infrequent, occur in limited geographic locations, and range from asymptomatic infection to severe illness and death. METHODS Descriptive clinical and epidemiological information on human babesiosis cases was collated from state communicable disease reports and medical records of patients hospitalized from 1982 to 1993. Univariate and multivariate analyses were performed to determine prognostic factors associated with severe disease outcome (hospitalization ending in death, duration of hospitalization > 14 days, or intensive care unit stay > 2 days). RESULTS Between 1982 and 1993, 139 patients were hospitalized with babesiosis in New York State. Nine patients (6.5%) died, 35 (25.2%) were admitted to the intensive care unit, and 35 (25.2%) required hospitalization for more than 14 days. Mean age at first hospitalization was 62.5 years. Sixty-two percent were male, and 91% resided in Suffolk County, Long Island. The most common symptoms were fatigue/malaise/weakness (91%), fever (91%), shaking chills (77%), and diaphoresis (69%). Past medical records showed that 52% of patients had a history of chronic disease; 12% had a history of Lyme disease; 12% had undergone a splenectomy; and 2% had undergone a blood transfusion. There was a 12- to 14-day delay between onset of symptoms and initiation of appropriate antibiotic treatment. Univariate analyses showed alkaline phosphatase levels greater than 125 U/L, white blood cell counts greater than 5 x 10(9)/L, history of cardiac abnormality, history of splenectomy, presence of heart murmur, and parasitemia values of 0.04 or higher to be significantly associated with disease severity. Multiple logistic regression analyses indicated that male sex, alkaline phosphatase values greater than 125 U/L, and white blood cell counts greater than 5 x 10(9)/L remained strong predictors of severe outcome. CONCLUSIONS Human babesiosis is a rare but debilitating and potentially fatal illness, especially in the elderly. Prompt disease diagnosis and treatment are essential but are often delayed, as seen in our series. This delay reinforces the need for enhanced public and physician education targeted toward residents and visitors to the few high-risk geographic areas where disease and Ixodes scapularis ticks are endemic. Patients presenting with certain prognostic indicators (male sex, alkaline phosphatase values > 125 U/L, and white blood cell counts >5 x 10(9)/L) require comprehensive and aggressive medical care to prevent further deterioration. Since babesiosis is only 1 of 3 currently recognized diseases transmitted by I scapularis ticks, primary prevention recommendations will also reduce human exposure to Lyme disease and human granulocytic ehrlichiosis.
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Affiliation(s)
- D J White
- Division of Infectious Disease, Wadsworth Center, New York State Department of Health, Albany 12201-0509, USA
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10
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Heimberger T, Chang HG, Shaikh M, Crotty L, Morse D, Birkhead G. Knowledge and attitudes of healthcare workers about influenza: why are they not getting vaccinated? Infect Control Hosp Epidemiol 1995; 16:412-5. [PMID: 7673647 DOI: 10.1086/647139] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.3] [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: 01/26/2023]
Abstract
In a survey of employees at a chronic care psychiatric facility following an influenza outbreak, previous influenza vaccination (relative risk [RR], 69.7; 95% confidence interval [CI95], 25.2 to 192.4), age > or = 50 years (RR, 2.4; CI95, 1.3 to 4.5), and knowledge that vaccine does not cause influenza (RR, 2.3; CI95, 1.3 to 3.7) were the factors most predictive of current influenza vaccination. Medical personnel were less likely than nonmedical employees to be vaccinated (RR, 0.5; CI95, 0.3 to 0.9). Educational efforts to address misconceptions about vaccination plus more vigorous administrative measures to vaccinate employees should be considered.
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Affiliation(s)
- T Heimberger
- Division of Field Epidemiology, Centers for Disease Control and Prevention, Atlanta, GA, USA
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11
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Schoonmaker D, Heimberger T, Birkhead G. Comparison of ribotyping and restriction enzyme analysis using pulsed-field gel electrophoresis for distinguishing Legionella pneumophila isolates obtained during a nosocomial outbreak. J Clin Microbiol 1992; 30:1491-8. [PMID: 1320629 PMCID: PMC265316 DOI: 10.1128/jcm.30.6.1491-1498.1992] [Citation(s) in RCA: 128] [Impact Index Per Article: 4.0] [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: 12/26/2022] Open
Abstract
Because of the ubiquity of Legionella isolates in aquatic habitats, epidemiologic evaluation of Legionella pneumophila strains is important in the investigation and subsequent control of nosocomial outbreaks of legionellosis. In this study, ribotyping and restriction enzyme analysis by pulsed-field gel electrophoresis (PFGE) were used to compare isolates of L. pneumophila obtained from patients and the environment during a nosocomial outbreak with unrelated control strains. Restriction enzyme analysis by PFGE resolved 14 different patterns among the L. pneumophila serogroup 1 and L. pneumophila serogroup 6 isolates involved in the study. Two of the patterns were observed in the three L. pneumophila serogroup 6 isolates from patients with confirmed nosocomial infections and environmental isolates from the potable water supply, which was, therefore, believed to be the source of the patients' infections. Three more patterns that were not present in isolates from patients with legionellosis were seen in isolates from the hospital environment, demonstrating the presence of multiple strains in the hospital environment. In the outbreak, one distinct pattern occurred among the L. pneumophila serogroup 1 isolates from patients with nosocomial infections, suggesting a common source; however, the source could not be determined. By comparison, ribotyping generated five patterns. However, some control strains of both L. pneumophila serogroups 1 and 6 possessed the same ribotypes as were present in the outbreak isolates. Both techniques were used successfully to subtype the isolates obtained during the investigation of the outbreak. Furthermore, restriction enzyme analysis by PFGE was useful for subdividing ribotypes and for distinguishing strains involved in the outbreak from epidemiologically unrelated strains.
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Affiliation(s)
- D Schoonmaker
- Laboratories for Bacteriology, Wadsworth Center for Laboratories and Research, Albany, New York
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12
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Heimberger T, Birkhead G, Bornstein D, Same K, Morse D. Control of nosocomial Legionnaires' disease through hot water flushing and supplemental chlorination of potable water. J Infect Dis 1991; 163:413. [PMID: 1988527 DOI: 10.1093/infdis/163.2.413] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
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Abstract
Prior to January 1986, only one case of Lyme disease was reported from Virginia. In 1986-87, however, the Virginia Department of Health observed an increase in reports of suspected Lyme disease by physicians, despite the fact that Ixodes dammini is not highly prevalent in the Virginia tick population. Twenty-eight cases of Lyme disease were identified in Virginia, of which eight cases occurred in 1986 and 20 in 1987. Lyme disease appears to be increasing in frequency in Virginia and moving southward along the Eastern Atlantic Seaboard.
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Affiliation(s)
- T Heimberger
- Division of Infectious Diseases, Medical College of Virginia, Virginia Commonwealth University, Richmond
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Abstract
Zygomycosis of the basal ganglia should be recognized as a syndrome in intravenous drug users associated with a culture-negative cellular CSF, fever, lethargy, and lesions apparent on contrast-enhanced CT scans of the head. The infection is most likely the result of intravenous inoculation of fungal spores. This entity is different from the rhinocerebral zygomycosis seen with diabetes mellitus and other diseases. In the rhinocerebral form, there are external signs of the disease with involvement of the orbit, paranasal sinuses, and palate. In these drug users, infection was directed to areas deep within the brain.
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Affiliation(s)
- G M Stave
- Department of Medicine, Medical College of Virginia/Virginia Commonwealth University, Richmond
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Affiliation(s)
- J Sahai
- Medical College of Virginia, Virginia Commonwealth University, Richmond 23298
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