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Dielectrophoresis as a Tool to Reveal the Potential Role of Ion Channels and Early Electrophysiological Changes in Osteoarthritis. MICROMACHINES 2021; 12:mi12080949. [PMID: 34442571 PMCID: PMC8402151 DOI: 10.3390/mi12080949] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Revised: 07/30/2021] [Accepted: 08/08/2021] [Indexed: 11/16/2022]
Abstract
Diseases such as osteoarthritis (OA) are commonly characterized at the molecular scale by gene expression and subsequent protein production; likewise, the effects of pharmaceutical interventions are typically characterized by the effects of molecular interactions. However, these phenomena are usually preceded by numerous precursor steps, many of which involve significant ion influx or efflux. As a consequence, rapid assessment of cell electrophysiology could play a significant role in unravelling the mechanisms underlying drug interactions and progression of diseases, such as OA. In this study, we used dielectrophoresis (DEP), a technique that allows rapid, label-free determination of the dielectric parameters to assess the role of potassium ions on the dielectric characteristics of chondrocytes, and to investigate the electrophysiological differences between healthy chondrocytes and those from an in vitro arthritic disease model. Our results showed that DEP was able to detect a significant decrease in membrane conductance (6191 ± 738 vs. 8571 ± 1010 S/m2), membrane capacitance (10.3 ± 1.47 vs. 14.5 ± 0.01 mF/m2), and whole cell capacitance (5.4 ± 0.7 vs. 7.5 ± 0.3 pF) following inhibition of potassium channels using 10 mM tetraethyl ammonium, compared to untreated healthy chondrocytes. Moreover, cells from the OA model had a different response to DEP force in comparison to healthy cells; this was seen in terms of both a decreased membrane conductivity (782 S/m2 vs. 1139 S/m2) and a higher whole cell capacitance (9.58 ± 3.4 vs. 3.7 ± 1.3 pF). The results show that DEP offers a high throughput method, capable of detecting changes in membrane electrophysiological properties and differences between disease states.
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2
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Schotten U. From translation to integration: how to approach the complexity of atrial fibrillation mechanisms. Cardiovasc Res 2021; 117:e88-e90. [PMID: 34131703 DOI: 10.1093/cvr/cvab168] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- Ulrich Schotten
- Department of Physiology, Cardiovascular Research Institute Maastricht, PO Box 616, 6200 MD Maastricht, The Netherlands
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3
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Abstract
This review focusses on novel findings in atrial fibrillation mechanisms derived from mapping studies. Recent panoramic mapping techniques have identified 2 arrhythmic mechanisms of interest, namely, rotational (rotors) and ectopic focal activations as drivers of atrial fibrillation. Epicardial adipose tissue and fatty infiltration into the myocardium have been described as novel substrates for atrial fibrillation. There is increasing appreciation that the thin atrial walls harbor a complex 3-dimensional electrostructural substrate to contribute to atrial fibrillation sustenance. Further research is warranted to advance the field toward more targeted therapy.
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Affiliation(s)
- Dennis H Lau
- Department of Cardiology, Centre for Heart Rhythm Disorders, University of Adelaide, Royal Adelaide Hospital, 1 Port Road, Adelaide, South Australia 5000, Australia
| | - Dominik Linz
- Department of Cardiology, Centre for Heart Rhythm Disorders, University of Adelaide, Royal Adelaide Hospital, 1 Port Road, Adelaide, South Australia 5000, Australia
| | - Prashanthan Sanders
- Department of Cardiology, Centre for Heart Rhythm Disorders, University of Adelaide, Royal Adelaide Hospital, 1 Port Road, Adelaide, South Australia 5000, Australia.
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4
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Thomas D, Christ T, Fabritz L, Goette A, Hammwöhner M, Heijman J, Kockskämper J, Linz D, Odening KE, Schweizer PA, Wakili R, Voigt N. German Cardiac Society Working Group on Cellular Electrophysiology state-of-the-art paper: impact of molecular mechanisms on clinical arrhythmia management. Clin Res Cardiol 2018; 108:577-599. [PMID: 30306295 DOI: 10.1007/s00392-018-1377-1] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/13/2018] [Accepted: 09/24/2018] [Indexed: 12/19/2022]
Abstract
Cardiac arrhythmias remain a common challenge and are associated with significant morbidity and mortality. Effective and safe rhythm control strategies are a primary, yet unmet need in everyday clinical practice. Despite significant pharmacological and technological advances, including catheter ablation and device-based therapies, the development of more effective alternatives is of significant interest to increase quality of life and to reduce symptom burden, hospitalizations and mortality. The mechanistic understanding of pathophysiological pathways underlying cardiac arrhythmias has advanced profoundly, opening up novel avenues for mechanism-based therapeutic approaches. Current management of arrhythmias, however, is primarily guided by clinical and demographic characteristics of patient groups as opposed to individual, patient-specific mechanisms and pheno-/genotyping. With this state-of-the-art paper, the Working Group on Cellular Electrophysiology of the German Cardiac Society aims to close the gap between advanced molecular understanding and clinical decision-making in cardiac electrophysiology. The significance of cellular electrophysiological findings for clinical arrhythmia management constitutes the main focus of this document. Clinically relevant knowledge of pathophysiological pathways of arrhythmias and cellular mechanisms of antiarrhythmic interventions are summarized. Furthermore, the specific molecular background for the initiation and perpetuation of atrial and ventricular arrhythmias and mechanism-based strategies for therapeutic interventions are highlighted. Current "hot topics" in atrial fibrillation are critically appraised. Finally, the establishment and support of cellular and translational electrophysiology programs in clinical rhythmology departments is called for to improve basic-science-guided patient management.
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Affiliation(s)
- Dierk Thomas
- Department of Cardiology, Medical University Hospital, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany. .,HCR (Heidelberg Center for Heart Rhythm Disorders), Heidelberg, Germany. .,DZHK (German Center for Cardiovascular Research), partner site Heidelberg/Mannheim, Heidelberg, Germany.
| | - Torsten Christ
- Department of Experimental Pharmacology and Toxicology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.,DZHK (German Center for Cardiovascular Research), partner site Hamburg/Kiel/Lübeck, Hamburg, Germany
| | - Larissa Fabritz
- Institute of Cardiovascular Sciences, University of Birmingham, Birmingham, UK.,Department of Cardiology, UHB NHS Trust, Birmingham, UK.,Department of Cardiovascular Medicine, Division of Rhythmology, University Hospital Münster, Münster, Germany
| | - Andreas Goette
- St. Vincenz-Hospital, Paderborn, Germany.,Working Group: Molecular Electrophysiology, University Hospital Magdeburg, Magdeburg, Germany
| | - Matthias Hammwöhner
- St. Vincenz-Hospital, Paderborn, Germany.,Working Group: Molecular Electrophysiology, University Hospital Magdeburg, Magdeburg, Germany
| | - Jordi Heijman
- Institute of Pharmacology, West German Heart and Vascular Center, University Duisburg-Essen, Essen, Germany.,Cardiovascular Research Institute Maastricht, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Jens Kockskämper
- Biochemical and Pharmacological Center (BPC) Marburg, Institute of Pharmacology and Clinical Pharmacy, University of Marburg, Marburg, Germany
| | - Dominik Linz
- Centre for Heart Rhythm Disorders, South Australian Health and Medical Research Institute, University of Adelaide and Royal Adelaide Hospital, Adelaide, SA, Australia.,Experimental Electrophysiology, University Hospital of Saarland, Homburg, Saar, Germany
| | - Katja E Odening
- Department of Cardiology and Angiology I, Heart Center University of Freiburg, Freiburg, Germany.,Faculty of Medicine, University of Freiburg, Freiburg, Germany.,Institute for Experimental Cardiovascular Medicine, Heart Center University of Freiburg, Freiburg, Germany
| | - Patrick A Schweizer
- Department of Cardiology, Medical University Hospital, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany.,HCR (Heidelberg Center for Heart Rhythm Disorders), Heidelberg, Germany.,DZHK (German Center for Cardiovascular Research), partner site Heidelberg/Mannheim, Heidelberg, Germany.,Heidelberg Research Center for Molecular Medicine (HRCMM), Heidelberg, Germany
| | - Reza Wakili
- Department of Cardiology and Vascular Medicine, Medical Faculty, West German Heart Center, University Hospital Essen, Essen, Germany
| | - Niels Voigt
- Institute of Pharmacology and Toxicology, University Medical Center Göttingen, Georg-August University Göttingen, Robert-Koch-Straße 40, 37075, Göttingen, Germany. .,DZHK (German Center for Cardiovascular Research), partner site Göttingen, Göttingen, Germany.
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5
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Thanigaimani S, Lau DH, Agbaedeng T, Elliott AD, Mahajan R, Sanders P. Molecular mechanisms of atrial fibrosis: implications for the clinic. Expert Rev Cardiovasc Ther 2017; 15:247-256. [DOI: 10.1080/14779072.2017.1299005] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Affiliation(s)
- Shivshankar Thanigaimani
- Centre for Heart Rhythm Disorders, South Australian Health and Medical Research Institute, University of Adelaide and Royal Adelaide Hospital, Adelaide, Australia
| | - Dennis H Lau
- Centre for Heart Rhythm Disorders, South Australian Health and Medical Research Institute, University of Adelaide and Royal Adelaide Hospital, Adelaide, Australia
| | - Thomas Agbaedeng
- Centre for Heart Rhythm Disorders, South Australian Health and Medical Research Institute, University of Adelaide and Royal Adelaide Hospital, Adelaide, Australia
| | - Adrian D. Elliott
- Centre for Heart Rhythm Disorders, South Australian Health and Medical Research Institute, University of Adelaide and Royal Adelaide Hospital, Adelaide, Australia
| | - Rajiv Mahajan
- Centre for Heart Rhythm Disorders, South Australian Health and Medical Research Institute, University of Adelaide and Royal Adelaide Hospital, Adelaide, Australia
| | - Prashanthan Sanders
- Centre for Heart Rhythm Disorders, South Australian Health and Medical Research Institute, University of Adelaide and Royal Adelaide Hospital, Adelaide, Australia
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6
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Schotten U, Dobrev D, Platonov PG, Kottkamp H, Hindricks G. Current controversies in determining the main mechanisms of atrial fibrillation. J Intern Med 2016; 279:428-38. [PMID: 26991914 DOI: 10.1111/joim.12492] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Despite considerable basic research into the mechanisms of atrial fibrillation (AF), not much progress has been made in the prognosis of patients with AF. With the exception of anticoagulant therapy, current treatments for AF still do not improve major cardiovascular outcomes. This may be due partly to the diverse aetiology of AF with increasingly more factors found to contribute to the arrhythmia. In addition, a strong increase has been seen in the technological complexity of the methods used to quantify the main pathophysiological alterations underlying the initiation and progression of AF. Because of the lack of standardization of the technological approaches currently used, the perception of basic mechanisms of AF varies widely in the scientific community. Areas of debate include the role of Ca(2+) -handling alterations associated with AF, the contribution and noninvasive assessment of the degree of atrial fibrosis, and the best techniques to identify electrophysiological drivers of AF. In this review, we will summarize the state of the art of these controversial topics and describe the diverse approaches to investigating and the scientific opinions on leading AF mechanisms. Finally, we will highlight the need for transparency in scientific reporting and standardization of terminology, assumptions, algorithms and experimental conditions used for the development of better AF therapies.
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Affiliation(s)
- U Schotten
- Cardiovascular Research Institute Maastricht, Maastricht Centre of Systems Biology, Maastricht University, Maastricht, The Netherlands
| | - D Dobrev
- Institute of Pharmacology, West German Heart and Vascular Center, School of Medicine, University Duisburg-Essen, Essen, Germany
| | - P G Platonov
- Center for Integrative Electrocardiology at Lund University (CIEL), Arrhythmia Clinic, Skåne University Hospital, Lund, Sweden
| | - H Kottkamp
- Department of Rhythmology, Klinik Hirslanden, Zürich, Switzerland
| | - G Hindricks
- Department of Cardiac Electrophysiology, Heart Center, University of Leipzig, Leipzig, Germany
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7
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Weckbach LT, Grabmaier U, Clauss S, Wakili R. MicroRNAs as a diagnostic tool for heart failure and atrial fibrillation. Curr Opin Pharmacol 2016; 27:24-30. [PMID: 26852213 DOI: 10.1016/j.coph.2016.01.001] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2015] [Accepted: 01/12/2016] [Indexed: 01/24/2023]
Abstract
MicroRNAs (miRNAs) are small non-coding RNAs, which are directly involved in the regulation of post-transcriptional gene expression. Their biological function represents a repression of protein expression of the targeted messenger-RNA(s). Expression of several miRNAs is somehow tissue-specific or cell-specific and their expression pattern can reflect an underlying pathophysiological condition. Beyond this biological function their role as potential biomarkers has been emerged in the past years. This was based on the fact that miRNAs can be detected in blood samples (serum or plasma) in a surprisingly stable form, by contrast to mRNAs. This fact made miRNAs interesting candidates for biomarkers providing information with respect to a potentially ongoing pathophysiological condition and could thereby have an impact on specific treatment strategies in patients. In this review we try to provide an overview of the potential role of miRNAs as a diagnostic tool in atrial fibrillation and heart failure patients taken different methodological aspects and distinct type of patients into account.
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Affiliation(s)
- Ludwig T Weckbach
- Department of Medicine I, University Hospital Munich, Campus Grosshadern, Ludwig-Maximilians-University Munich, Germany
| | - Ulrich Grabmaier
- Department of Medicine I, University Hospital Munich, Campus Grosshadern, Ludwig-Maximilians-University Munich, Germany
| | - Sebastian Clauss
- Department of Medicine I, University Hospital Munich, Campus Grosshadern, Ludwig-Maximilians-University Munich, Germany; Cardiovascular Research Center, Massachusetts General Hospital, Boston, MA, USA; DZHK (German Centre for Cardiovascular Research), Partner Site Munich, Germany
| | - Reza Wakili
- Department of Medicine I, University Hospital Munich, Campus Grosshadern, Ludwig-Maximilians-University Munich, Germany; DZHK (German Centre for Cardiovascular Research), Partner Site Munich, Germany.
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8
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Clauss S, Sinner MF, Kääb S, Wakili R. The Role of MicroRNAs in Antiarrhythmic Therapy for Atrial Fibrillation. Arrhythm Electrophysiol Rev 2015; 4:146-55. [PMID: 26835117 DOI: 10.15420/aer.2015.4.3.146] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/13/2015] [Accepted: 10/23/2015] [Indexed: 12/19/2022] Open
Abstract
Atrial fibrillation (AF) is the most common arrhythmia worldwide and has an enormous impact on our healthcare system as it is a major contributor of morbidity and mortality. Although there are several therapeutic options available, treatment of AF still remains challenging. AF pathophysiology is complex and still incompletely understood. In general, our understanding of AF is based on two mechanistic paradigms as functional hallmarks of AF: ectopic activity and reentry. Both ectopic activity and reentry are the result of remodelling processes. Functional and/or expressional changes in ion channels, connexins or calcium-handling proteins are important factors in electrical remodelling, whereas signalling processes leading to atrial dilatation and atrial fibrosis are key factors of structural remodelling. In recent years, new intriguing key players in AF pathophysiology have been identified: microRNAs (miRNAs). MiRNAs are short, non-coding RNA fragments that can regulate gene expression and have been demonstrated as important modifiers in signalling cascades leading to electrical and structural remodelling. In this article we review the miRNA-mediated molecular mechanisms underlying AF with special emphasis on the perspective of miRNAs as potential therapeutic targets for AF treatment.
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Affiliation(s)
- Sebastian Clauss
- Cardiovascular Research Center, Massachusetts General Hospital, Boston, MA, US; University Hospital Munich, Ludwig-Maximilians University Munich; DZHK (German Centre for Cardiovascular Research), Partner Site Munich, Germany
| | - Moritz F Sinner
- University Hospital Munich, Ludwig-Maximilians University Munich
| | - Stefan Kääb
- University Hospital Munich, Ludwig-Maximilians University Munich; DZHK (German Centre for Cardiovascular Research), Partner Site Munich, Germany
| | - Reza Wakili
- University Hospital Munich, Ludwig-Maximilians University Munich; DZHK (German Centre for Cardiovascular Research), Partner Site Munich, Germany
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9
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Lau DH, Schotten U, Mahajan R, Antic NA, Hatem SN, Pathak RK, Hendriks JML, Kalman JM, Sanders P. Novel mechanisms in the pathogenesis of atrial fibrillation: practical applications. Eur Heart J 2015; 37:1573-81. [DOI: 10.1093/eurheartj/ehv375] [Citation(s) in RCA: 101] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/14/2015] [Accepted: 07/21/2015] [Indexed: 12/21/2022] Open
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10
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Schotten U, Hatem S, Ravens U, Jaïs P, Müller FU, Goette A, Rohr S, Antoons G, Pieske B, Scherr D, Oto A, Casadei B, Verheule S, Cartlidge D, Steinmeyer K, Götsche T, Dobrev D, Kockskämper J, Lendeckel U, Fabritz L, Kirchhof P, Camm AJ. The European Network for Translational Research in Atrial Fibrillation (EUTRAF): objectives and initial results. Europace 2015; 17:1457-66. [DOI: 10.1093/europace/euv252] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2015] [Accepted: 06/29/2015] [Indexed: 01/25/2023] Open
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11
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Gorenek B, Lip GYH. Recent scientific documents from the European Heart Rhythm Association (EHRA). Europace 2015; 17:1161-3. [PMID: 26045503 DOI: 10.1093/europace/euv193] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
| | - Gregory Y H Lip
- University of Birmingham Centre for Cardiovascular Sciences, City Hospital, Birmingham, UK Aalborg Thrombosis Research Unit, Department of Clinical Medicine, Aalborg University, Aalborg, Denmark
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