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Cruz FM, Macías Á, Moreno-Manuel AI, Gutiérrez LK, Vera-Pedrosa ML, Martínez-Carrascoso I, Pérez PS, Robles JMR, Bermúdez-Jiménez FJ, Díaz-Agustín A, de Benito FM, Arias-Santiago S, Braza-Boils A, Martín-Martínez M, Gutierrez-Rodríguez M, Bernal JA, Zorio E, Jiménez-Jaimez J, Jalife J. Extracellular Kir2.1 C122Y Mutant Upsets Kir2.1-PIP 2 Bonds and Is Arrhythmogenic in Andersen-Tawil Syndrome. Circ Res 2024; 134:e52-e71. [PMID: 38497220 PMCID: PMC11009053 DOI: 10.1161/circresaha.123.323895] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Accepted: 02/29/2024] [Indexed: 03/19/2024]
Abstract
BACKGROUND Andersen-Tawil syndrome type 1 is a rare heritable disease caused by mutations in the gene coding the strong inwardly rectifying K+ channel Kir2.1. The extracellular Cys (cysteine)122-to-Cys154 disulfide bond in the channel structure is crucial for proper folding but has not been associated with correct channel function at the membrane. We evaluated whether a human mutation at the Cys122-to-Cys154 disulfide bridge leads to Kir2.1 channel dysfunction and arrhythmias by reorganizing the overall Kir2.1 channel structure and destabilizing its open state. METHODS We identified a Kir2.1 loss-of-function mutation (c.366 A>T; p.Cys122Tyr) in an ATS1 family. To investigate its pathophysiological implications, we generated an AAV9-mediated cardiac-specific mouse model expressing the Kir2.1C122Y variant. We employed a multidisciplinary approach, integrating patch clamping and intracardiac stimulation, molecular biology techniques, molecular dynamics, and bioluminescence resonance energy transfer experiments. RESULTS Kir2.1C122Y mice recapitulated the ECG features of ATS1 independently of sex, including corrected QT prolongation, conduction defects, and increased arrhythmia susceptibility. Isolated Kir2.1C122Y cardiomyocytes showed significantly reduced inwardly rectifier K+ (IK1) and inward Na+ (INa) current densities independently of normal trafficking. Molecular dynamics predicted that the C122Y mutation provoked a conformational change over the 2000-ns simulation, characterized by a greater loss of hydrogen bonds between Kir2.1 and phosphatidylinositol 4,5-bisphosphate than wild type (WT). Therefore, the phosphatidylinositol 4,5-bisphosphate-binding pocket was destabilized, resulting in a lower conductance state compared with WT. Accordingly, on inside-out patch clamping, the C122Y mutation significantly blunted Kir2.1 sensitivity to increasing phosphatidylinositol 4,5-bisphosphate concentrations. In addition, the Kir2.1C122Y mutation resulted in channelosome degradation, demonstrating temporal instability of both Kir2.1 and NaV1.5 proteins. CONCLUSIONS The extracellular Cys122-to-Cys154 disulfide bond in the tridimensional Kir2.1 channel structure is essential for the channel function. We demonstrate that breaking disulfide bonds in the extracellular domain disrupts phosphatidylinositol 4,5-bisphosphate-dependent regulation, leading to channel dysfunction and defects in Kir2.1 energetic stability. The mutation also alters functional expression of the NaV1.5 channel and ultimately leads to conduction disturbances and life-threatening arrhythmia characteristic of Andersen-Tawil syndrome type 1.
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Affiliation(s)
- Francisco M. Cruz
- Centro Nacional de Investigaciones Cardiovasculares (CNIC), 28029 Madrid, Spain
| | - Álvaro Macías
- Centro Nacional de Investigaciones Cardiovasculares (CNIC), 28029 Madrid, Spain
| | | | - Lilian K. Gutiérrez
- Centro Nacional de Investigaciones Cardiovasculares (CNIC), 28029 Madrid, Spain
| | | | | | | | | | - Francisco J Bermúdez-Jiménez
- Centro Nacional de Investigaciones Cardiovasculares (CNIC), 28029 Madrid, Spain
- Servicio de Cardiología, Hospital Universitario Virgen de las Nieves, Granada, Spain
- Instituto de Investigación Biosanitaria de Granada IBS, Granada, Spain
| | - Aitor Díaz-Agustín
- Instituto de Química Médica (IQM), Consejo Superior de Investigaciones Científicas (CSIC), 28006 Madrid, Spain
| | - Fernando Martínez de Benito
- Centro Nacional de Investigaciones Cardiovasculares (CNIC), 28029 Madrid, Spain
- CIBER de Enfermedades Cardiovasculares (CIBERCV), Madrid, Spain
| | - Salvador Arias-Santiago
- Servicio de Dermatología Hospital Universitario Virgen de las Nieves
- Instituto de Investigación Biosanitaria de Granada IBS, Granada, Spain
| | - Aitana Braza-Boils
- Unit of Inherited Cardiomyopathies and Sudden Death (CAFAMUSME), Health Research Institute La Fe, La Fe Hospital, Valencia, Spain
- Cardiology Department, Hospital Universitario y Politécnico La Fe, Valencia, Spain
| | - Mercedes Martín-Martínez
- Instituto de Química Médica (IQM), Consejo Superior de Investigaciones Científicas (CSIC), 28006 Madrid, Spain
| | - Marta Gutierrez-Rodríguez
- Instituto de Química Médica (IQM), Consejo Superior de Investigaciones Científicas (CSIC), 28006 Madrid, Spain
| | - Juan A. Bernal
- Centro Nacional de Investigaciones Cardiovasculares (CNIC), 28029 Madrid, Spain
- CIBER de Enfermedades Cardiovasculares (CIBERCV), Madrid, Spain
| | - Esther Zorio
- CIBER de Enfermedades Cardiovasculares (CIBERCV), Madrid, Spain
- Unit of Inherited Cardiomyopathies and Sudden Death (CAFAMUSME), Health Research Institute La Fe, La Fe Hospital, Valencia, Spain
- Cardiology Department, Hospital Universitario y Politécnico La Fe, Valencia, Spain
| | - Juan Jiménez-Jaimez
- Servicio de Cardiología, Hospital Universitario Virgen de las Nieves, Granada, Spain
- Instituto de Investigación Biosanitaria de Granada IBS, Granada, Spain
| | - José Jalife
- Centro Nacional de Investigaciones Cardiovasculares (CNIC), 28029 Madrid, Spain
- CIBER de Enfermedades Cardiovasculares (CIBERCV), Madrid, Spain
- Departments of Medicine and Molecular & Integrative Physiology, University of Michigan, Ann Arbor, MI, USA
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Rems L, Rainot A, Wiczew D, Szulc N, Tarek M. Cellular excitability and ns-pulsed electric fields: Potential involvement of lipid oxidation in the action potential activation. Bioelectrochemistry 2024; 155:108588. [PMID: 37879163 DOI: 10.1016/j.bioelechem.2023.108588] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2023] [Revised: 10/10/2023] [Accepted: 10/10/2023] [Indexed: 10/27/2023]
Abstract
Recent studies showed that nanosecond pulsed electric fields (nsPEFs) can activate voltage-gated ion channels (VGICs) and trigger action potentials (APs) in excitable cells. Under physiological conditions, VGICs' activation takes place on time scales of the order 10-100 µs. These time scales are considerably longer than the applied pulse duration, thus activation of VGICs by nsPEFs remains puzzling and there is no clear consensus on the mechanisms involved. Here we propose that changes in local electrical properties of the cell membrane due to lipid oxidation might be implicated in AP activation. We first use MD simulations of model lipid bilayers with increasing concentration of primary and secondary lipid oxidation products and demonstrate that oxidation not only increases the bilayer conductance, but also the bilayer capacitance. Equipped with MD-based characterization of electrical properties of oxidized bilayers, we then resort to AP modelling at the cell level with Hodgkin-Huxley-type models. We confirm that a local change in membrane properties, particularly the increase in membrane conductance, due to formation of oxidized membrane lesions can be high enough to trigger an AP, even when no external stimulus is applied. However, excessive accumulation of oxidized lesions (or other conductive defects) can lead to altered cell excitability.
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Affiliation(s)
- Lea Rems
- University of Ljubljana, Faculty of Electrical Engineering, SI-1000 Ljubljana, Slovenia.
| | | | - Daniel Wiczew
- Université de Lorraine, CNRS, LPCT, F-54000 Nancy, France
| | - Natalia Szulc
- Université de Lorraine, CNRS, LPCT, F-54000 Nancy, France
| | - Mounir Tarek
- Université de Lorraine, CNRS, LPCT, F-54000 Nancy, France.
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3
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Silkuniene G, Mangalanathan UM, Pakhomov AG, Pakhomova ON. Silencing of ATP1A1 attenuates cell membrane disruption by nanosecond electric pulses. Biochem Biophys Res Commun 2023; 677:93-97. [PMID: 37566922 DOI: 10.1016/j.bbrc.2023.08.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2023] [Revised: 08/03/2023] [Accepted: 08/04/2023] [Indexed: 08/13/2023]
Abstract
This study explored the role of the Na/K-ATPase (NKA) in membrane permeabilization induced by nanosecond electric pulses. Using CRISPR/Cas9 and shRNA, we silenced the ATP1A1 gene, which encodes α1 NKA subunit in U937 human monocytes. Silencing reduced the rate and the cumulative uptake of YoPro-1 dye after electroporation by 300-ns, 7-10 kV/cm pulses, while ouabain, a specific NKA inhibitor, enhanced YoPro-1 entry. We conclude that the α1 subunit supports the electropermeabilized membrane state, by forming or stabilizing electropores or by hindering repair mechanisms, and this role is independent of NKA's ion pump function.
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Affiliation(s)
- Giedre Silkuniene
- Frank Reidy Research Center for Bioelectrics, Old Dominion University, Norfolk, VA, 23508, USA; Institute for Digestive System Research, Lithuanian University of Health Sciences, 44307, Kaunas, Lithuania
| | - Uma M Mangalanathan
- Frank Reidy Research Center for Bioelectrics, Old Dominion University, Norfolk, VA, 23508, USA
| | - Andrei G Pakhomov
- Frank Reidy Research Center for Bioelectrics, Old Dominion University, Norfolk, VA, 23508, USA
| | - Olga N Pakhomova
- Frank Reidy Research Center for Bioelectrics, Old Dominion University, Norfolk, VA, 23508, USA.
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4
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Ruiz-Fernández AR, Campos L, Villanelo F, Garate JA, Perez-Acle T. Protein-Mediated Electroporation in a Cardiac Voltage-Sensing Domain Due to an nsPEF Stimulus. Int J Mol Sci 2023; 24:11397. [PMID: 37511161 PMCID: PMC10379607 DOI: 10.3390/ijms241411397] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2023] [Revised: 06/15/2023] [Accepted: 07/05/2023] [Indexed: 07/30/2023] Open
Abstract
This study takes a step in understanding the physiological implications of the nanosecond pulsed electric field (nsPEF) by integrating molecular dynamics simulations and machine learning techniques. nsPEF, a state-of-the-art technology, uses high-voltage electric field pulses with a nanosecond duration to modulate cellular activity. This investigation reveals a relatively new and underexplored phenomenon: protein-mediated electroporation. Our research focused on the voltage-sensing domain (VSD) of the NaV1.5 sodium cardiac channel in response to nsPEF stimulation. We scrutinized the VSD structures that form pores and thereby contribute to the physical chemistry that governs the defibrillation effect of nsPEF. To do so, we conducted a comprehensive analysis involving the clustering of 142 replicas simulated for 50 ns under nsPEF stimuli. We subsequently pinpointed the representative structures of each cluster and computed the free energy between them. We find that the selected VSD of NaV1.5 forms pores under nsPEF stimulation, but in a way that significant differs from the traditional VSD opening. This study not only extends our understanding of nsPEF and its interaction with protein channels but also adds a new effect to further study.
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Affiliation(s)
| | - Leonardo Campos
- Computational Biology Lab, Fundación Ciencia & Vida, Santiago 7780272, Chile
- Facultad de Ingeniería y Tecnología, Universidad San Sebastián, Santiago 8420524, Chile
| | - Felipe Villanelo
- Computational Biology Lab, Fundación Ciencia & Vida, Santiago 7780272, Chile
- Facultad de Ingeniería y Tecnología, Universidad San Sebastián, Santiago 8420524, Chile
| | - Jose Antonio Garate
- Computational Biology Lab, Fundación Ciencia & Vida, Santiago 7780272, Chile
- Facultad de Ingeniería y Tecnología, Universidad San Sebastián, Santiago 8420524, Chile
- Millennium Nucleus im NanoBioPhysics, Universidad de Valparaiso, Valparaiso 2351319, Chile
| | - Tomas Perez-Acle
- Computational Biology Lab, Fundación Ciencia & Vida, Santiago 7780272, Chile
- Facultad de Ingeniería y Tecnología, Universidad San Sebastián, Santiago 8420524, Chile
- Centro Interdisciplinario de Neurociencia de Valparaíso, Universidad de Valparaíso, Valparaiso 2360102, Chile
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5
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Cruz FM, Macías Á, Moreno-Manuel AI, Gutiérrez LK, Vera-Pedrosa ML, Martínez-Carrascoso I, Pérez PS, Robles JMR, Bermúdez-Jiménez FJ, Díaz-Agustín A, de Benito FM, Santiago SA, Braza-Boils A, Martín-Martínez M, Gutierrez-Rodríguez M, Bernal JA, Zorio E, Jiménez-Jaimez J, Jalife J. Extracellular cysteine disulfide bond break at Cys122 disrupts PIP 2-dependent Kir2.1 channel function and leads to arrhythmias in Andersen-Tawil Syndrome. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.06.07.544151. [PMID: 37333254 PMCID: PMC10274791 DOI: 10.1101/2023.06.07.544151] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/20/2023]
Abstract
Background Andersen-Tawil Syndrome Type 1 (ATS1) is a rare heritable disease caused by mutations in the strong inwardly rectifying K+ channel Kir2.1. The extracellular Cys122-to-Cys154 disulfide bond in the Kir2.1 channel structure is crucial for proper folding, but has not been associated with correct channel function at the membrane. We tested whether a human mutation at the Cys122-to-Cys154 disulfide bridge leads to Kir2.1 channel dysfunction and arrhythmias by reorganizing the overall Kir2.1 channel structure and destabilizing the open state of the channel. Methods and Results We identified a Kir2.1 loss-of-function mutation in Cys122 (c.366 A>T; p.Cys122Tyr) in a family with ATS1. To study the consequences of this mutation on Kir2.1 function we generated a cardiac specific mouse model expressing the Kir2.1C122Y mutation. Kir2.1C122Y animals recapitulated the abnormal ECG features of ATS1, like QT prolongation, conduction defects, and increased arrhythmia susceptibility. Kir2.1C122Y mouse cardiomyocytes showed significantly reduced inward rectifier K+ (IK1) and inward Na+ (INa) current densities independently of normal trafficking ability and localization at the sarcolemma and the sarcoplasmic reticulum. Kir2.1C122Y formed heterotetramers with wildtype (WT) subunits. However, molecular dynamic modeling predicted that the Cys122-to-Cys154 disulfide-bond break induced by the C122Y mutation provoked a conformational change over the 2000 ns simulation, characterized by larger loss of the hydrogen bonds between Kir2.1 and phosphatidylinositol-4,5-bisphosphate (PIP2) than WT. Therefore, consistent with the inability of Kir2.1C122Y channels to bind directly to PIP2 in bioluminescence resonance energy transfer experiments, the PIP2 binding pocket was destabilized, resulting in a lower conductance state compared with WT. Accordingly, on inside-out patch-clamping the C122Y mutation significantly blunted Kir2.1 sensitivity to increasing PIP2 concentrations. Conclusion The extracellular Cys122-to-Cys154 disulfide bond in the tridimensional Kir2.1 channel structure is essential to channel function. We demonstrated that ATS1 mutations that break disulfide bonds in the extracellular domain disrupt PIP2-dependent regulation, leading to channel dysfunction and life-threatening arrhythmias.
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Affiliation(s)
- Francisco M. Cruz
- Centro Nacional de Investigaciones Cardiovasculares (CNIC), 28029 Madrid, Spain
| | - Álvaro Macías
- Centro Nacional de Investigaciones Cardiovasculares (CNIC), 28029 Madrid, Spain
| | | | - Lilian K. Gutiérrez
- Centro Nacional de Investigaciones Cardiovasculares (CNIC), 28029 Madrid, Spain
| | | | | | | | | | - Francisco J Bermúdez-Jiménez
- Centro Nacional de Investigaciones Cardiovasculares (CNIC), 28029 Madrid, Spain
- Servicio de Cardiología, Hospital Universitario Virgen de las Nieves, Granada, Spain
- Instituto de Investigación Biosanitaria de Granada IBS, Granada, Spain
| | - Aitor Díaz-Agustín
- Instituto de Química Médica (IQM), Consejo Superior de Investigaciones Científicas (CSIC), 28006 Madrid, Spain
| | - Fernando Martínez de Benito
- Centro Nacional de Investigaciones Cardiovasculares (CNIC), 28029 Madrid, Spain
- CIBER de Enfermedades Cardiovasculares (CIBERCV), Madrid, Spain
| | - Salvador Arias Santiago
- Servicio de Dermatología Hospital Universitario Virgen de las Nieves
- Instituto de Investigación Biosanitaria de Granada IBS, Granada, Spain
| | - Aitana Braza-Boils
- Unit of Inherited Cardiomyopathies and Sudden Death (CAFAMUSME), Health Research Institute La Fe, La Fe Hospital, Valencia, Spain
- Cardiology Department, Hospital Universitario y Politécnico La Fe, Valencia, Spain
| | - Mercedes Martín-Martínez
- Instituto de Química Médica (IQM), Consejo Superior de Investigaciones Científicas (CSIC), 28006 Madrid, Spain
| | - Marta Gutierrez-Rodríguez
- Instituto de Química Médica (IQM), Consejo Superior de Investigaciones Científicas (CSIC), 28006 Madrid, Spain
| | - Juan A. Bernal
- Centro Nacional de Investigaciones Cardiovasculares (CNIC), 28029 Madrid, Spain
- CIBER de Enfermedades Cardiovasculares (CIBERCV), Madrid, Spain
| | - Esther Zorio
- CIBER de Enfermedades Cardiovasculares (CIBERCV), Madrid, Spain
- Unit of Inherited Cardiomyopathies and Sudden Death (CAFAMUSME), Health Research Institute La Fe, La Fe Hospital, Valencia, Spain
- Cardiology Department, Hospital Universitario y Politécnico La Fe, Valencia, Spain
| | - Juan Jiménez-Jaimez
- Servicio de Cardiología, Hospital Universitario Virgen de las Nieves, Granada, Spain
- Instituto de Investigación Biosanitaria de Granada IBS, Granada, Spain
| | - José Jalife
- Centro Nacional de Investigaciones Cardiovasculares (CNIC), 28029 Madrid, Spain
- CIBER de Enfermedades Cardiovasculares (CIBERCV), Madrid, Spain
- Departments of Medicine and Molecular & Integrative Physiology, University of Michigan, Ann Arbor, MI, USA
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Tuergan T, Zhang R, Chen X, Aihemaiti N, Guo X, Ran B, Jiang T, Guo Q, Aji T. LncRNA Regulation Mechanism in Hepatic Alveolar Echinococcosis with Nanosecond Pulse. Acta Parasitol 2023:10.1007/s11686-023-00672-3. [PMID: 37103765 DOI: 10.1007/s11686-023-00672-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2022] [Accepted: 03/08/2023] [Indexed: 04/28/2023]
Abstract
BACKGROUND The mortality of patients infected with hepatic alveolar echinococcosis (HAE) was higher. The aim of this study was to investigate the therapeutic effect of nanosecond pulsed electric fields (nsPEFs) on HAE in rats and explore the related molecular mechanisms. METHODS Establishment of HAE rat model and the lesions were treated with nsPEFs. The RNA of lesions in the high voltage nsPEFs treatment group and model group were extracted, and lncRNA and mRNA sequence analyses was performed. After obtaining the differentially expressed lncRNAs and mRNAs between the two groups, enrichment analysis was performed for mRNAs. The target genes of lncRNAs were predicted through co-location and co-expression. The expression of important lncRNAs and target genes in lesions was detected by qPCR. RESULTS The HAE rat model was successfully established. After nsPEFs treatment, the size of lesions was improved significantly. Then, we identified 270 differentially expressed lncRNAs and 1659 differentially expressed mRNAs between the high voltage nsPEFs treatment group and model group. Enrichment analysis showed that the differentially expressed mRNAs were mainly enriched in metabolism and inflammation. Five important lncRNAs regulatory networks were identified, then Cpa1, Cpb1, Cel, Cela2a, and Cela3b were identified as key target genes. Importantly, the expression of 5 lncRNAs and 5 target genes was verified in the lesions. CONCLUSIONS Preliminary results had shown that HAE treatment with nsPEFs can inhibit the growth of lesions. NsPEFs treatment altered gene expression in the lesions, and some genes were regulated by lncRNAs. The therapeutic mechanism may involve metabolism and inflammation.
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Affiliation(s)
- Talaiti Tuergan
- Xinjiang Medical University Affiliated First Hospital, Ürümqi, China
| | - Ruiqing Zhang
- Xinjiang Medical University Affiliated First Hospital, Ürümqi, China
| | - Xinhua Chen
- Xinjiang Medical University Affiliated First Hospital, Ürümqi, China
| | | | - Xiaozhe Guo
- Xinjiang Medical University Affiliated First Hospital, Ürümqi, China
| | - Bo Ran
- Xinjiang Medical University Affiliated First Hospital, Ürümqi, China
| | - Tiemin Jiang
- Xinjiang Medical University Affiliated First Hospital, Ürümqi, China
| | - Qiang Guo
- Xinjiang Medical University Affiliated First Hospital, Ürümqi, China
| | - Tuerganaili Aji
- Xinjiang Medical University Affiliated First Hospital, Ürümqi, China.
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Scuderi M, Dermol-Černe J, Batista Napotnik T, Chaigne S, Bernus O, Benoist D, Sigg DC, Rems L, Miklavčič D. Characterization of Experimentally Observed Complex Interplay between Pulse Duration, Electrical Field Strength, and Cell Orientation on Electroporation Outcome Using a Time-Dependent Nonlinear Numerical Model. Biomolecules 2023; 13:727. [PMID: 37238597 PMCID: PMC10216437 DOI: 10.3390/biom13050727] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Revised: 04/17/2023] [Accepted: 04/18/2023] [Indexed: 05/28/2023] Open
Abstract
Electroporation is a biophysical phenomenon involving an increase in cell membrane permeability to molecules after a high-pulsed electric field is applied to the tissue. Currently, electroporation is being developed for non-thermal ablation of cardiac tissue to treat arrhythmias. Cardiomyocytes have been shown to be more affected by electroporation when oriented with their long axis parallel to the applied electric field. However, recent studies demonstrate that the preferentially affected orientation depends on the pulse parameters. To gain better insight into the influence of cell orientation on electroporation with different pulse parameters, we developed a time-dependent nonlinear numerical model where we calculated the induced transmembrane voltage and pores creation in the membrane due to electroporation. The numerical results show that the onset of electroporation is observed at lower electric field strengths for cells oriented parallel to the electric field for pulse durations ≥10 µs, and cells oriented perpendicular for pulse durations ~100 ns. For pulses of ~1 µs duration, electroporation is not very sensitive to cell orientation. Interestingly, as the electric field strength increases beyond the onset of electroporation, perpendicular cells become more affected irrespective of pulse duration. The results obtained using the developed time-dependent nonlinear model are corroborated by in vitro experimental measurements. Our study will contribute to the process of further development and optimization of pulsed-field ablation and gene therapy in cardiac treatments.
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Affiliation(s)
- Maria Scuderi
- Faculty of Electrical Engineering, University of Ljubljana, SI-1000 Ljubljana, Slovenia
| | - Janja Dermol-Černe
- Faculty of Electrical Engineering, University of Ljubljana, SI-1000 Ljubljana, Slovenia
| | - Tina Batista Napotnik
- Faculty of Electrical Engineering, University of Ljubljana, SI-1000 Ljubljana, Slovenia
| | - Sebastien Chaigne
- INSERM, CRCTB, U 1045, IHU Liryc, University of Bordeaux, F-33000 Bordeaux, France
| | - Olivier Bernus
- INSERM, CRCTB, U 1045, IHU Liryc, University of Bordeaux, F-33000 Bordeaux, France
| | - David Benoist
- INSERM, CRCTB, U 1045, IHU Liryc, University of Bordeaux, F-33000 Bordeaux, France
| | - Daniel C. Sigg
- Medtronic, Cardiac Ablation Solutions, Minneapolis, MN 55105, USA
| | - Lea Rems
- Faculty of Electrical Engineering, University of Ljubljana, SI-1000 Ljubljana, Slovenia
| | - Damijan Miklavčič
- Faculty of Electrical Engineering, University of Ljubljana, SI-1000 Ljubljana, Slovenia
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8
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Gudvangen E, Mangalanathan U, Semenov I, Kiester AS, Keppler MA, Ibey BL, Bixler JN, Pakhomov AG. Pulsed Electric Field Ablation of Esophageal Malignancies and Mitigating Damage to Smooth Muscle: An In Vitro Study. Int J Mol Sci 2023; 24:ijms24032854. [PMID: 36769172 PMCID: PMC9917603 DOI: 10.3390/ijms24032854] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Revised: 01/29/2023] [Accepted: 01/30/2023] [Indexed: 02/05/2023] Open
Abstract
Cancer ablation therapies aim to be efficient while minimizing damage to healthy tissues. Nanosecond pulsed electric field (nsPEF) is a promising ablation modality because of its selectivity against certain cell types and reduced neuromuscular effects. We compared cell killing efficiency by PEF (100 pulses, 200 ns-10 µs duration, 10 Hz) in a panel of human esophageal cells (normal and pre-malignant epithelial and smooth muscle). Normal epithelial cells were less sensitive than the pre-malignant ones to unipolar PEF (15-20% higher LD50, p < 0.05). Smooth muscle cells (SMC) oriented randomly in the electric field were more sensitive, with 30-40% lower LD50 (p < 0.01). Trains of ten, 300-ns pulses at 10 kV/cm caused twofold weaker electroporative uptake of YO-PRO-1 dye in normal epithelial cells than in either pre-malignant cells or in SMC oriented perpendicularly to the field. Aligning SMC with the field reduced the dye uptake fourfold, along with a twofold reduction in Ca2+ transients. A 300-ns pulse induced a twofold smaller transmembrane potential in cells aligned with the field, making them less vulnerable to electroporation. We infer that damage to SMC from nsPEF ablation of esophageal malignancies can be minimized by applying the electric field parallel to the predominant SMC orientation.
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Affiliation(s)
- Emily Gudvangen
- Frank Reidy Research Center for Bioelectrics, Old Dominion University, Norfolk, VA 23508, USA
| | - Uma Mangalanathan
- Frank Reidy Research Center for Bioelectrics, Old Dominion University, Norfolk, VA 23508, USA
| | - Iurii Semenov
- Frank Reidy Research Center for Bioelectrics, Old Dominion University, Norfolk, VA 23508, USA
| | - Allen S. Kiester
- Bioeffects Division, Airman System Directorate, 711th Human Performance Wing, Air Force Research Laboratory, JBSA Fort Sam Houston, San Antonio, TX 78234, USA
| | | | - Bennett L. Ibey
- Bioeffects Division, Airman System Directorate, 711th Human Performance Wing, Air Force Research Laboratory, JBSA Fort Sam Houston, San Antonio, TX 78234, USA
| | - Joel N. Bixler
- Bioeffects Division, Airman System Directorate, 711th Human Performance Wing, Air Force Research Laboratory, JBSA Fort Sam Houston, San Antonio, TX 78234, USA
| | - Andrei G. Pakhomov
- Frank Reidy Research Center for Bioelectrics, Old Dominion University, Norfolk, VA 23508, USA
- Correspondence:
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9
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Varghese F, Philpott JM, Neuber JU, Hargrave B, Zemlin CW. Surgical Ablation of Cardiac Tissue with Nanosecond Pulsed Electric Fields in Swine. Cardiovasc Eng Technol 2023; 14:52-59. [PMID: 35705890 DOI: 10.1007/s13239-022-00634-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/26/2021] [Accepted: 05/18/2022] [Indexed: 11/02/2022]
Abstract
BACKGROUND Myocardial tissue can be ablated by the application nanosecond pulsed fields (nsPEFs). The applied electric fields irreversibly permeabilize cell membranes and thereby kill myocytes while leaving the extracellular matrix intact. METHODS In domestic pigs (n = 10), hearts were exposed via sternotomy and either ablated in vivo ([Formula: see text] = 5) or in excised, Langendorff-perfused hearts ([Formula: see text] = 5). The nsPEFs consisted of 6-36 pulses of 300 ns each, delivered at 3-6 Hz; the voltage applied varied from 10 to 12 kV. Atrial lesions were either created after inserting the bottom jaw of the bipolar clamp into the atrium via a purse string incision (2-3 lesions per atrium) or by clamping a double layer of tissue at the appendages (one lesion per atrium). Ventricular lesions were created after an incision at the apex. The transmurality of each lesion was determined at three points along the lesion using a triphenyl tetrazolium chloride (TTC) stain. RESULTS All 27 atrial lesions were transmural. This includes 13/13 purse string lesions (39/39 sections, tissue thickness 2.5-4.5 mm) and 14/14 appendage lesions (42/42 sections, tissue thickness 8-12 mm). All 3 right ventricular lesions were transmural (9/9 sections, 18 pulses per lesion). Left ventricular lesions were always transmural for 36 pulses (3/3 lesions, 9/9 sections). All lesions have highly consistent width across the wall. There were no pulse-induced arrhythmias or other complications during the procedure. CONCLUSIONS nsPEF ablation reliably created acute lesions in porcine atrial and ventricular myocardium. It has far better penetration and is faster than both radiofrequency ablation and cryoablation and it is free from thermal side effects.
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Affiliation(s)
- Frency Varghese
- Department of Electrical and Computer Engineering, Old Dominion University, Norfolk, VA, USA
- Center for Bioelectrics, Old Dominion University, Norfolk, VA, USA
- Department of Cardiovascular Medicine, University of Massachusetts Medical School, Worcester, MA, USA
| | - Jonathan M Philpott
- Department of Surgery, Eastern Virginia Medical School, Norfolk, VA, USA
- Mid-Atlantic Thoracic Surgeons, Sentara Heart Hospital, Norfolk, VA, USA
| | - Johanna U Neuber
- Department of Electrical and Computer Engineering, Old Dominion University, Norfolk, VA, USA
- Center for Bioelectrics, Old Dominion University, Norfolk, VA, USA
| | - Barbara Hargrave
- Center for Bioelectrics, Old Dominion University, Norfolk, VA, USA
- Department of Biological Sciences, Old Dominion University, Norfolk, VA, USA
| | - Christian W Zemlin
- Department of Electrical and Computer Engineering, Old Dominion University, Norfolk, VA, USA.
- Center for Bioelectrics, Old Dominion University, Norfolk, VA, USA.
- Division of Cardiothoracic Surgery, Washington University School of Medicine, 660 S Euclid Ave, St. Louis, MO, 63110, USA.
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10
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Kim V, Semenov I, Kiester AS, Keppler MA, Ibey BL, Bixler JN, Pakhomov AG. Action spectra and mechanisms of (in) efficiency of bipolar electric pulses at electroporation. Bioelectrochemistry 2023; 149:108319. [PMID: 36375440 PMCID: PMC9729435 DOI: 10.1016/j.bioelechem.2022.108319] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2022] [Revised: 10/19/2022] [Accepted: 11/04/2022] [Indexed: 11/09/2022]
Abstract
The reversal of the electric field direction inhibits various biological effects of nanosecond electric pulses (nsEP). This feature, known as "bipolar cancellation," enables interference targeting of nsEP bioeffects remotely from stimulating electrodes, for prospective applications such as precise cancer ablation and non-invasive deep brain stimulation. This study was undertaken to achieve the maximum cancellation of electroporation, by quantifying the impact of the pulse shape, duration, number, and repetition rate across a broad range of electric field strengths. Monolayers of endothelial cells (BPAE) were electroporated in a non-uniform electric field. Cell membrane permeabilization was quantified by YO-PRO-1 (YP) dye uptake and correlated to local electric field strength. For most conditions tested, adding an opposite polarity phase reduced YP uptake by 50-80 %. The strongest cancellation, which reduced YP uptake by 95-97 %, was accomplished by adding a 50 % second phase to 600-ns pulses delivered at a high repetition rate of 833 kHz. Strobe photography of nanosecond kinetics of membrane potential in single CHO cells revealed the temporal summation of polarization by individual unipolar nsEP applied at sub-MHz rate, leading to enhanced electroporation. In contrast, there was no summation for bipolar pulses, and increasing their repetition rate suppressed electroporation. These new findings are discussed in the context of bipolar cancellation mechanisms and remote focusing applications.
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Affiliation(s)
- Vitalii Kim
- Frank Reidy Research Center for Bioelectrics, Old Dominion University, Norfolk, VA, USA
| | - Iurii Semenov
- Frank Reidy Research Center for Bioelectrics, Old Dominion University, Norfolk, VA, USA
| | - Allen S Kiester
- Bioeffects Division, Airman System Directorate, 711th Human Performance Wing, Air Force Research Laboratory, JBSA Fort Sam Houston, TX, USA
| | | | - Bennett L Ibey
- Bioeffects Division, Airman System Directorate, 711th Human Performance Wing, Air Force Research Laboratory, JBSA Fort Sam Houston, TX, USA
| | - Joel N Bixler
- Bioeffects Division, Airman System Directorate, 711th Human Performance Wing, Air Force Research Laboratory, JBSA Fort Sam Houston, TX, USA
| | - Andrei G Pakhomov
- Frank Reidy Research Center for Bioelectrics, Old Dominion University, Norfolk, VA, USA.
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11
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Casciola M, Feaster TK, Caiola MJ, Keck D, Blinova K. Human in vitro assay for irreversible electroporation cardiac ablation. Front Physiol 2023; 13:1064168. [PMID: 36699682 PMCID: PMC9869257 DOI: 10.3389/fphys.2022.1064168] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2022] [Accepted: 11/29/2022] [Indexed: 01/12/2023] Open
Abstract
Introduction: Pulsed electric field (PEF) cardiac ablation has been recently proposed as a technique to treat drug resistant atrial fibrillation by inducing cell death through irreversible electroporation (IRE). Improper PEF dosing can result in thermal damage or reversible electroporation. The lack of comprehensive and systematic studies to select PEF parameters for safe and effective IRE cardiac treatments hinders device development and regulatory decision-making. Human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) have been proposed as an alternative to animal models in the evaluation of cardiac electrophysiology safety. Methods: We developed a novel high-throughput in vitro assay to quantify the electric field threshold (EFT) for electroporation (acute effect) and cell death (long-term effect) in hiPSC-CMs. Monolayers of hiPSC-CMs were cultured in high-throughput format and exposed to clinically relevant biphasic PEF treatments. Electroporation and cell death areas were identified using fluorescent probes and confocal microscopy; electroporation and cell death EFTs were quantified by comparison of fluorescent images with electric field numerical simulations. Results: Study results confirmed that PEF induces electroporation and cell death in hiPSC-CMs, dependent on the number of pulses and the amplitude, duration, and repetition frequency. In addition, PEF-induced temperature increase, absorbed dose, and total treatment time for each PEF parameter combination are reported. Discussion: Upon verification of the translatability of the in vitro results presented here to in vivo models, this novel hiPSC-CM-based assay could be used as an alternative to animal or human studies and can assist in early nonclinical device development, as well as inform regulatory decision-making for cardiac ablation medical devices.
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12
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Sowa PW, Kiełbik AS, Pakhomov AG, Gudvangen E, Mangalanathan U, Adams V, Pakhomova ON. How to alleviate cardiac injury from electric shocks at the cellular level. Front Cardiovasc Med 2022; 9:1004024. [PMID: 36620647 PMCID: PMC9812960 DOI: 10.3389/fcvm.2022.1004024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Accepted: 12/08/2022] [Indexed: 12/24/2022] Open
Abstract
Electric shocks, the only effective therapy for ventricular fibrillation, also electroporate cardiac cells and contribute to the high-mortality post-cardiac arrest syndrome. Copolymers such as Poloxamer 188 (P188) are known to preserve the membrane integrity and viability of electroporated cells, but their utility against cardiac injury from cardiopulmonary resuscitation (CPR) remains to be established. We studied the time course of cell killing, mechanisms of cell death, and protection with P188 in AC16 human cardiomyocytes exposed to micro- or nanosecond pulsed electric field (μsPEF and nsPEF) shocks. A 3D printer was customized with an electrode holder to precisely position electrodes orthogonal to a cell monolayer in a nanofiber multiwell plate. Trains of nsPEF shocks (200, 300-ns pulses at 1.74 kV) or μsPEF shocks (20, 100-μs pulses at 300 V) produced a non-uniform electric field enabling efficient measurements of the lethal effect in a wide range of the electric field strength. Cell viability and caspase 3/7 expression were measured by fluorescent microscopy 2-24 h after the treatment. nsPEF shocks caused little or no caspase 3/7 activation; most of the lethally injured cells were permeable to propidium dye already at 2 h after the exposure. In contrast, μsPEF shocks caused strong activation of caspase 3/7 at 2 h and the number of dead cells grew up to 24 h, indicating the prevalence of the apoptotic death pathway. P188 at 0.2-1% reduced cell death, suggesting its potential utility in vivo to alleviate electric injury from defibrillation.
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Affiliation(s)
- Pamela W. Sowa
- Frank Reidy Research Center for Bioelectrics, Old Dominion University, Norfolk, VA, United States,Laboratory of Molecular and Experimental Cardiology, Heart Center Dresden, Technische Universität Dresden, Dresden, Germany,Department of Cardiology and Angiology, University Hospital Tübingen, Eberhard Karls University of Tübingen, Tübingen, Germany,*Correspondence: Pamela W. Sowa,
| | - Aleksander S. Kiełbik
- Frank Reidy Research Center for Bioelectrics, Old Dominion University, Norfolk, VA, United States,Department of Molecular and Cellular Biology, Faculty of Pharmacy, Wrocław Medical University, Wrocław, Poland
| | - Andrei G. Pakhomov
- Frank Reidy Research Center for Bioelectrics, Old Dominion University, Norfolk, VA, United States
| | - Emily Gudvangen
- Frank Reidy Research Center for Bioelectrics, Old Dominion University, Norfolk, VA, United States
| | - Uma Mangalanathan
- Frank Reidy Research Center for Bioelectrics, Old Dominion University, Norfolk, VA, United States
| | - Volker Adams
- Laboratory of Molecular and Experimental Cardiology, Heart Center Dresden, Technische Universität Dresden, Dresden, Germany
| | - Olga N. Pakhomova
- Frank Reidy Research Center for Bioelectrics, Old Dominion University, Norfolk, VA, United States
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13
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Ruiz-Fernández AR, Rosemblatt M, Perez-Acle T. Nanosecond pulsed electric field (nsPEF) and vaccines: a novel technique for the inactivation of SARS-CoV-2 and other viruses? Ann Med 2022; 54:1749-1756. [PMID: 35786157 PMCID: PMC9258060 DOI: 10.1080/07853890.2022.2087898] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Since the beginning of 2020, worldwide attention has been being focussed on SARS-CoV-2, the second strain of the severe acute respiratory syndrome virus. Although advances in vaccine technology have been made, particularly considering the advent of mRNA vaccines, up to date, no single antigen design can ensure optimal immune response. Therefore, new technologies must be tested as to their ability to further improve vaccines. Nanosecond Pulsed Electric Field (nsPEF) is one such method showing great promise in different biomedical and industrial fields, including the fight against COVID-19. Of note, available research shows that nsPEF directly damages the cell's DNA, so it is critical to determine if this technology could be able to fragment either viral DNA or RNA so as to be used as a novel technology to produce inactivated pathogenic agents that may, in turn, be used for the production of vaccines. Considering the available evidence, we propose that nsPEF may be used to produce inactivated SARS-CoV-2 viruses that may in turn be used to produce novel vaccines, as another tool to address 20 the current COVID-19 pandemic.Key MessagesViral inactivation by using pulsed electric fields in the nanosecond frequency.DNA fragmentation by a Nanosecond Pulsed Electric Field (nsPEF).Opportunity to apply new technologies in vaccine development.
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Affiliation(s)
- A R Ruiz-Fernández
- Computational Biology Lab, Centro Ciencia & Vida, Fundación Ciencia & Vida, Santiago, Chile.,Facultad de Ingeniería y Tecnología, Universidad San Sebastián, Santiago, Chile
| | - M Rosemblatt
- Computational Biology Lab, Centro Ciencia & Vida, Fundación Ciencia & Vida, Santiago, Chile.,Facultad de Medicina y Ciencia, Universidad San Sebastián, Santiago, Chile
| | - T Perez-Acle
- Computational Biology Lab, Centro Ciencia & Vida, Fundación Ciencia & Vida, Santiago, Chile.,Facultad de Ingeniería y Tecnología, Universidad San Sebastián, Santiago, Chile
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14
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Silkunas M, Gudvangen E, Novickij V, Pakhomov AG. Sub-MHz bursts of nanosecond pulses excite neurons at paradoxically low electric field thresholds without membrane damage. BIOCHIMICA ET BIOPHYSICA ACTA. BIOMEMBRANES 2022; 1864:184034. [PMID: 35981654 DOI: 10.1016/j.bbamem.2022.184034] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Revised: 07/29/2022] [Accepted: 08/08/2022] [Indexed: 06/15/2023]
Abstract
Neuromodulation applications of nanosecond electric pulses (nsEP) are hindered by their low potency to elicit action potentials in neurons. Excitation by a single nsEP requires a strong electric field which injures neurons by electroporation. We bypassed the high electric field requirement by replacing single nsEP stimuli with high-frequency brief nsEP bursts. In hippocampal neurons, excitation thresholds progressively decreased at nsEP frequencies above 20-200 kHz, with up to 20-30-fold reduction at sub-MHz and MHz rates. For a fixed burst duration, thresholds were determined by the duty cycle, irrespective of the specific nsEP duration, rate, or number of pulses per burst. For 100-μs bursts of 100-, 400-, or 800-ns pulses, the threshold decreased as a power function when the duty cycle exceeded 3-5 %. nsEP bursts were compared with single "long" pulses whose duration and amplitude matched the duration and the time-average amplitude of the burst. Such pulses deliver the same electric charge as bursts, within the same time interval. High-frequency nsEP bursts excited neurons at the time-average electric field 2-3 times below the threshold for a single long pulse. For example, the excitation threshold of 139 ± 14 V/cm for a single 100-μs pulse decreased to 57 ± 8 V/cm for a 100-μs burst of 100-ns, 0.25-MHz pulses (p < 0.001). Applying nsEP in bursts reduced or prevented the loss of excitability in multiple stimulation attempts. Stimulation by high-frequency nsEP bursts is a powerful novel approach to excite neurons at paradoxically low electric charge while also avoiding the electroporative membrane damage.
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Affiliation(s)
- Mantas Silkunas
- Frank Reidy Research Center for Bioelectrics, Old Dominion University, Norfolk, VA 23508, USA; Institute for Digestive System Research, Lithuanian University of Health Sciences, 44307 Kaunas, Lithuania
| | - Emily Gudvangen
- Frank Reidy Research Center for Bioelectrics, Old Dominion University, Norfolk, VA 23508, USA
| | | | - Andrei G Pakhomov
- Frank Reidy Research Center for Bioelectrics, Old Dominion University, Norfolk, VA 23508, USA.
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15
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Ruiz-Fernández AR, Campos L, Gutierrez-Maldonado SE, Núñez G, Villanelo F, Perez-Acle T. Nanosecond Pulsed Electric Field (nsPEF): Opening the Biotechnological Pandora’s Box. Int J Mol Sci 2022; 23:ijms23116158. [PMID: 35682837 PMCID: PMC9181413 DOI: 10.3390/ijms23116158] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Revised: 05/23/2022] [Accepted: 05/23/2022] [Indexed: 02/04/2023] Open
Abstract
Nanosecond Pulsed Electric Field (nsPEF) is an electrostimulation technique first developed in 1995; nsPEF requires the delivery of a series of pulses of high electric fields in the order of nanoseconds into biological tissues or cells. They primary effects in cells is the formation of membrane nanopores and the activation of ionic channels, leading to an incremental increase in cytoplasmic Ca2+ concentration, which triggers a signaling cascade producing a variety of effects: from apoptosis up to cell differentiation and proliferation. Further, nsPEF may affect organelles, making nsPEF a unique tool to manipulate and study cells. This technique is exploited in a broad spectrum of applications, such as: sterilization in the food industry, seed germination, anti-parasitic effects, wound healing, increased immune response, activation of neurons and myocites, cell proliferation, cellular phenotype manipulation, modulation of gene expression, and as a novel cancer treatment. This review thoroughly explores both nsPEF’s history and applications, with emphasis on the cellular effects from a biophysics perspective, highlighting the role of ionic channels as a mechanistic driver of the increase in cytoplasmic Ca2+ concentration.
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Affiliation(s)
- Alvaro R. Ruiz-Fernández
- Computational Biology Lab, Centro Científico y Tecnológico de Excelencia Ciencia & Vida, Fundación Ciencia & Vida, Santiago 7780272, Chile; (L.C.); (S.E.G.-M.); (G.N.); (F.V.)
- Facultad de Ingeniería y Tecnología, Universidad San Sebastian, Bellavista 7, Santiago 8420524, Chile
- Correspondence: (A.R.R.-F.); (T.P.-A.)
| | - Leonardo Campos
- Computational Biology Lab, Centro Científico y Tecnológico de Excelencia Ciencia & Vida, Fundación Ciencia & Vida, Santiago 7780272, Chile; (L.C.); (S.E.G.-M.); (G.N.); (F.V.)
- Facultad de Ingeniería y Tecnología, Universidad San Sebastian, Bellavista 7, Santiago 8420524, Chile
| | - Sebastian E. Gutierrez-Maldonado
- Computational Biology Lab, Centro Científico y Tecnológico de Excelencia Ciencia & Vida, Fundación Ciencia & Vida, Santiago 7780272, Chile; (L.C.); (S.E.G.-M.); (G.N.); (F.V.)
- Facultad de Ingeniería y Tecnología, Universidad San Sebastian, Bellavista 7, Santiago 8420524, Chile
| | - Gonzalo Núñez
- Computational Biology Lab, Centro Científico y Tecnológico de Excelencia Ciencia & Vida, Fundación Ciencia & Vida, Santiago 7780272, Chile; (L.C.); (S.E.G.-M.); (G.N.); (F.V.)
| | - Felipe Villanelo
- Computational Biology Lab, Centro Científico y Tecnológico de Excelencia Ciencia & Vida, Fundación Ciencia & Vida, Santiago 7780272, Chile; (L.C.); (S.E.G.-M.); (G.N.); (F.V.)
- Facultad de Ingeniería y Tecnología, Universidad San Sebastian, Bellavista 7, Santiago 8420524, Chile
| | - Tomas Perez-Acle
- Computational Biology Lab, Centro Científico y Tecnológico de Excelencia Ciencia & Vida, Fundación Ciencia & Vida, Santiago 7780272, Chile; (L.C.); (S.E.G.-M.); (G.N.); (F.V.)
- Facultad de Ingeniería y Tecnología, Universidad San Sebastian, Bellavista 7, Santiago 8420524, Chile
- Correspondence: (A.R.R.-F.); (T.P.-A.)
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16
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Bhattacharya S, Silkunas M, Gudvangen E, Mangalanathan U, Pakhomova ON, Pakhomov AG. Ca 2+ dependence and kinetics of cell membrane repair after electropermeabilization. BIOCHIMICA ET BIOPHYSICA ACTA. BIOMEMBRANES 2022; 1864:183823. [PMID: 34838875 DOI: 10.1016/j.bbamem.2021.183823] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Revised: 11/15/2021] [Accepted: 11/19/2021] [Indexed: 01/24/2023]
Abstract
Electroporation, in particular with nanosecond pulses, is an efficient technique to generate nanometer-size membrane lesions without the use of toxins or other chemicals. The restoration of the membrane integrity takes minutes and is only partially dependent on [Ca2+]. We explored the impact of Ca2+ on the kinetics of membrane resealing by monitoring the entry of a YO-PRO-1 dye (YP) in BPAE and HEK cells. Ca2+ was promptly removed or added after the electric pulse (EP) by a fast-step perfusion. YP entry increased sharply after the EP and gradually slowed down following either a single- or a double-exponential function. In BPAE cells permeabilized by a single 300- or 600-ns EP at 14 kV/cm in a Ca2+-free medium, perfusion with 2 mM of external Ca2+ advanced the 90% resealing and reduced the dye uptake about twofold. Membrane restoration was accomplished by a combination of fast, Ca2+-independent resealing (τ = 13-15 s) and slow, Ca2+-dependent processes (τ ~70 s with Ca2+ and ~ 110 s or more without it). These time constants did not change when the membrane damage was doubled by increasing EP duration from 300 to 600 ns. However, injury by microsecond-range EP (300 and 600 μs) took longer to recover even when the membrane initially was less damaged, presumably because of the larger size of pores made in the membrane. Full membrane recovery was not prevented by blocking both extra- and intracellular Ca2+ (by loading cells with BAPTA or after Ca2+ depletion from the reticulum), suggesting the recruitment of unknown Ca2+-independent repair mechanisms.
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Affiliation(s)
- Sayak Bhattacharya
- Frank Reidy Research Center for Bioelectrics, Old Dominion University, Norfolk, VA 23508, USA
| | - Mantas Silkunas
- Frank Reidy Research Center for Bioelectrics, Old Dominion University, Norfolk, VA 23508, USA; Institute for Digestive System Research, Lithuanian University of Health Sciences, 44307 Kaunas, Lithuania
| | - Emily Gudvangen
- Frank Reidy Research Center for Bioelectrics, Old Dominion University, Norfolk, VA 23508, USA
| | - Uma Mangalanathan
- Frank Reidy Research Center for Bioelectrics, Old Dominion University, Norfolk, VA 23508, USA
| | - Olga N Pakhomova
- Frank Reidy Research Center for Bioelectrics, Old Dominion University, Norfolk, VA 23508, USA
| | - Andrei G Pakhomov
- Frank Reidy Research Center for Bioelectrics, Old Dominion University, Norfolk, VA 23508, USA.
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17
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Electroporation safety factor of 300 nanosecond and 10 millisecond defibrillation in Langendorff-perfused rabbit hearts. PLoS One 2021; 16:e0257287. [PMID: 34559811 PMCID: PMC8462679 DOI: 10.1371/journal.pone.0257287] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Accepted: 08/30/2021] [Indexed: 11/19/2022] Open
Abstract
AIMS Recently, a new defibrillation modality using nanosecond pulses was shown to be effective at much lower energies than conventional 10 millisecond monophasic shocks in ex vivo experiments. Here we compare the safety factors of 300 nanosecond and 10 millisecond shocks to assess the safety of nanosecond defibrillation. METHODS AND RESULTS The safety factor, i.e. the ratio of median effective doses (ED50) for electroporative damage and defibrillation, was assessed for nanosecond and conventional (millisecond) defibrillation shocks in Langendorff-perfused New Zealand white rabbit hearts. In order to allow for multiple shock applications in a single heart, a pair of needle electrodes was used to apply shocks of varying voltage. Propidium iodide (PI) staining at the surface of the heart showed that nanosecond shocks had a slightly lower safety factor (6.50) than millisecond shocks (8.69), p = 0.02; while PI staining cross-sections in the electrode plane showed no significant difference (5.38 for 300 ns shocks and 6.29 for 10 ms shocks, p = 0.22). CONCLUSIONS In Langendorff-perfused rabbit hearts, nanosecond defibrillation has a similar safety factor as millisecond defibrillation, between 5 and 9, suggesting that nanosecond defibrillation can be performed safely.
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18
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Zemlin CW. Safety factor for electrostimulation with nanosecond pulses. Bioelectrochemistry 2021; 141:107882. [PMID: 34274877 DOI: 10.1016/j.bioelechem.2021.107882] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2020] [Revised: 06/08/2021] [Accepted: 06/28/2021] [Indexed: 11/19/2022]
Abstract
While electrical stimulation with pulses of milli- or microsecond duration is possible without electroporation, stimulation with nanosecond pulses typically entails electroporation, and nanosecond pulses can even cause electroporation without stimulation. A recently proposed explanation for this intriguing finding is that stimulation requires not only that a threshold membrane potential is reached, but also that it is sustained for a certain time tmin, while electroporation occurs almost immediately after a higher threshold potential is reached. Here we analytically derive stimulation and electroporation thresholds for membranes that satisfy these assumptions. We analyze the safety factor, i.e. the ratio between electroporation and stimulation threshold and its dependence on pulse duration, membrane charging time constant, and tmin. We find that the safety factor is sharply reduced if both the pulse duration and the membrane charging time constant are below tmin. We discuss different approaches to get models with varying tmin that could be used to experimentally test this theory and cardiac applications.
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Affiliation(s)
- Christian W Zemlin
- Division of Cardiothoracic Surgery, Washington University School of Medicine, Campus Box 8234, 660 S Euclid Ave, St. Louis, MO 63110, USA.
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19
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Kim V, Gudvangen E, Kondratiev O, Redondo L, Xiao S, Pakhomov AG. Peculiarities of Neurostimulation by Intense Nanosecond Pulsed Electric Fields: How to Avoid Firing in Peripheral Nerve Fibers. Int J Mol Sci 2021; 22:ijms22137051. [PMID: 34208945 PMCID: PMC8269031 DOI: 10.3390/ijms22137051] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Revised: 06/24/2021] [Accepted: 06/25/2021] [Indexed: 12/31/2022] Open
Abstract
Intense pulsed electric fields (PEF) are a novel modality for the efficient and targeted ablation of tumors by electroporation. The major adverse side effects of PEF therapies are strong involuntary muscle contractions and pain. Nanosecond-range PEF (nsPEF) are less efficient at neurostimulation and can be employed to minimize such side effects. We quantified the impact of the electrode configuration, PEF strength (up to 20 kV/cm), repetition rate (up to 3 MHz), bi- and triphasic pulse shapes, and pulse duration (down to 10 ns) on eliciting compound action potentials (CAPs) in nerve fibers. The excitation thresholds for single unipolar but not bipolar stimuli followed the classic strength–duration dependence. The addition of the opposite polarity phase for nsPEF increased the excitation threshold, with symmetrical bipolar nsPEF being the least efficient. Stimulation by nsPEF bursts decreased the excitation threshold as a power function above a critical duty cycle of 0.1%. The threshold reduction was much weaker for symmetrical bipolar nsPEF. Supramaximal stimulation by high-rate nsPEF bursts elicited only a single CAP as long as the burst duration did not exceed the nerve refractory period. Such brief bursts of bipolar nsPEF could be the best choice to minimize neuromuscular stimulation in ablation therapies.
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Affiliation(s)
- Vitalii Kim
- Frank Reidy Research Center for Bioelectrics, Old Dominion University, Norfolk, VA 23508, USA; (V.K.); (E.G.); (S.X.)
| | - Emily Gudvangen
- Frank Reidy Research Center for Bioelectrics, Old Dominion University, Norfolk, VA 23508, USA; (V.K.); (E.G.); (S.X.)
| | | | - Luis Redondo
- Lisbon Engineering Superior Institute, GIAAPP/ISEL, 1959-007 Lisbon, Portugal;
| | - Shu Xiao
- Frank Reidy Research Center for Bioelectrics, Old Dominion University, Norfolk, VA 23508, USA; (V.K.); (E.G.); (S.X.)
- Department of Electrical and Computer Engineering, Old Dominion University, Norfolk, VA 23508, USA
| | - Andrei G. Pakhomov
- Frank Reidy Research Center for Bioelectrics, Old Dominion University, Norfolk, VA 23508, USA; (V.K.); (E.G.); (S.X.)
- Correspondence:
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Exploring the Conformational Changes Induced by Nanosecond Pulsed Electric Fields on the Voltage Sensing Domain of a Ca 2+ Channel. MEMBRANES 2021; 11:membranes11070473. [PMID: 34206827 PMCID: PMC8303878 DOI: 10.3390/membranes11070473] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Revised: 06/11/2021] [Accepted: 06/13/2021] [Indexed: 12/21/2022]
Abstract
Nanosecond Pulsed Electric Field (nsPEF or Nano Pulsed Stimulation, NPS) is a technology that delivers a series of pulses of high-voltage electric fields during a short period of time, in the order of nanoseconds. The main consequence of nsPEF upon cells is the formation of nanopores, which is followed by the gating of ionic channels. Literature is conclusive in that the physiological mechanisms governing ion channel gating occur in the order of milliseconds. Hence, understanding how these channels can be activated by a nsPEF would be an important step in order to conciliate fundamental biophysical knowledge with improved nsPEF applications. To get insights on both the kinetics and thermodynamics of ion channel gating induced by nsPEF, in this work, we simulated the Voltage Sensing Domain (VSD) of a voltage-gated Ca2+ channel, inserted in phospholipidic membranes with different concentrations of cholesterol. We studied the conformational changes of the VSD under a nsPEF mimicked by the application of a continuous electric field lasting 50 ns with different intensities as an approach to reveal novel mechanisms leading to ion channel gating in such short timescales. Our results show that using a membrane with high cholesterol content, under an nsPEF of 50 ns and E→ = 0.2 V/nm, the VSD undergoes major conformational changes. As a whole, our work supports the notion that membrane composition may act as an allosteric regulator, specifically cholesterol content, which is fundamental for the response of the VSD to an external electric field. Moreover, changes on the VSD structure suggest that the gating of voltage-gated Ca2+ channels by a nsPEF may be due to major conformational changes elicited in response to the external electric field. Finally, the VSD/cholesterol-bilayer under an nsPEF of 50 ns and E→ = 0.2 V/nm elicits a pore formation across the VSD suggesting a new non-reported effect of nsPEF into cells, which can be called a “protein mediated electroporation”.
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21
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McBride S, Avazzadeh S, Wheatley AM, O’Brien B, Coffey K, Elahi A, O’Halloran M, Quinlan LR. Ablation Modalities for Therapeutic Intervention in Arrhythmia-Related Cardiovascular Disease: Focus on Electroporation. J Clin Med 2021; 10:jcm10122657. [PMID: 34208708 PMCID: PMC8235263 DOI: 10.3390/jcm10122657] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Revised: 06/13/2021] [Accepted: 06/14/2021] [Indexed: 02/06/2023] Open
Abstract
Targeted cellular ablation is being increasingly used in the treatment of arrhythmias and structural heart disease. Catheter-based ablation for atrial fibrillation (AF) is considered a safe and effective approach for patients who are medication refractory. Electroporation (EPo) employs electrical energy to disrupt cell membranes which has a minimally thermal effect. The nanopores that arise from EPo can be temporary or permanent. Reversible electroporation is transitory in nature and cell viability is maintained, whereas irreversible electroporation causes permanent pore formation, leading to loss of cellular homeostasis and cell death. Several studies report that EPo displays a degree of specificity in terms of the lethal threshold required to induce cell death in different tissues. However, significantly more research is required to scope the profile of EPo thresholds for specific cell types within complex tissues. Irreversible electroporation (IRE) as an ablative approach appears to overcome the significant negative effects associated with thermal based techniques, particularly collateral damage to surrounding structures. With further fine-tuning of parameters and longer and larger clinical trials, EPo may lead the way of adapting a safer and efficient ablation modality for the treatment of persistent AF.
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Affiliation(s)
- Shauna McBride
- Physiology and Cellular Physiology Laboratory, CÚRAM SFI Centre for Research in Medical Devices, School of Medicine, Human Biology Building, National University of Ireland (NUI) Galway, H91 W5P7 Galway, Ireland; (S.M.); (S.A.); (A.M.W.)
| | - Sahar Avazzadeh
- Physiology and Cellular Physiology Laboratory, CÚRAM SFI Centre for Research in Medical Devices, School of Medicine, Human Biology Building, National University of Ireland (NUI) Galway, H91 W5P7 Galway, Ireland; (S.M.); (S.A.); (A.M.W.)
| | - Antony M. Wheatley
- Physiology and Cellular Physiology Laboratory, CÚRAM SFI Centre for Research in Medical Devices, School of Medicine, Human Biology Building, National University of Ireland (NUI) Galway, H91 W5P7 Galway, Ireland; (S.M.); (S.A.); (A.M.W.)
| | - Barry O’Brien
- AtriAN Medical Limited, Unit 204, NUIG Business Innovation Centre, Upper Newcastle, H91 R6W6 Galway, Ireland; (B.O.); (K.C.)
| | - Ken Coffey
- AtriAN Medical Limited, Unit 204, NUIG Business Innovation Centre, Upper Newcastle, H91 R6W6 Galway, Ireland; (B.O.); (K.C.)
| | - Adnan Elahi
- Translational Medical Device Lab (TMDL), Lamb Translational Research Facility, University College Hospital Galway, H91 V4AY Galway, Ireland; (A.E.); (M.O.)
- Electrical & Electronic Engineering, School of Engineering, National University of Ireland Galway, H91 HX31 Galway, Ireland
| | - Martin O’Halloran
- Translational Medical Device Lab (TMDL), Lamb Translational Research Facility, University College Hospital Galway, H91 V4AY Galway, Ireland; (A.E.); (M.O.)
| | - Leo R. Quinlan
- Physiology and Cellular Physiology Laboratory, CÚRAM SFI Centre for Research in Medical Devices, School of Medicine, Human Biology Building, National University of Ireland (NUI) Galway, H91 W5P7 Galway, Ireland; (S.M.); (S.A.); (A.M.W.)
- CÚRAM, SFI Research Centre for Medical Devices, National University of Ireland Galway, H92 W2TY Galway, Ireland
- Correspondence:
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22
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Interference targeting of bipolar nanosecond electric pulses for spatially focused electroporation, electrostimulation, and tissue ablation. Bioelectrochemistry 2021; 141:107876. [PMID: 34171507 DOI: 10.1016/j.bioelechem.2021.107876] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Revised: 06/09/2021] [Accepted: 06/11/2021] [Indexed: 12/17/2022]
Abstract
Stimulation and electroporation by nanosecond electric pulses (nsEP) are distinguished by a phenomenon of bipolar cancellation, which stands for a reduced efficiency of bipolar pulses compared to unipolar ones. When two pairs of stimulating electrodes are arrayed in a quadrupole, bipolar cancellation inhibits nsEP effects near the electrodes, where the electric field is the strongest. Two properly shaped and synchronized bipolar nsEP overlay into a unipolar pulse towards the center of the electrode array, thus canceling the bipolar cancellation (a "CANCAN effect"). High efficiency of the re-created unipolar nsEP outweighs the weakening of the electric field with distance and focuses nsEP effects to the center. In monolayers of CHO, BPAE, and HEK cells, CANCAN effect achieved by the interference of two bipolar nsEP enhanced electroporation up to tenfold, with a peak at the quadrupole center. Introducing a time interval between bipolar nsEP prevented the formation of a unipolar pulse and eliminated the CANCAN effect. Strong electroporation by CANCAN stimuli killed cells over the entire area encompassed by the electrodes, whereas the time-separated pulses caused ablation only in the strongest electric field near the electrodes. The CANCAN approach is promising for uniform tumor ablation and stimulation targeting away from electrodes.
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23
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Muratori C, Silkuniene G, Mollica PA, Pakhomov AG, Pakhomova ON. The role of ESCRT-III and Annexin V in the repair of cell membrane permeabilization by the nanosecond pulsed electric field. Bioelectrochemistry 2021; 140:107837. [PMID: 34004548 DOI: 10.1016/j.bioelechem.2021.107837] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Revised: 04/30/2021] [Accepted: 05/04/2021] [Indexed: 01/25/2023]
Abstract
Exposure of living cells to intense nanosecond pulsed electric field (nsPEF) increases membrane permeability to small solutes, presumably by the formation of nanometer-size membrane lesions. Mechanisms responsible for the restoration of membrane integrity over the course of minutes after nsPEF have not been identified. This study explored if ESCRT-III and Annexin V calcium-dependent repair mechanisms, which play critical role in resealing large membrane lesions, are also activated by electroporation and contribute to the membrane resealing. The extent of membrane damage and the time course of resealing were monitored by the time-lapse imaging of propidium (Pr) uptake in human cervical carcinoma (HeLa) cells exposed to trains of 300-ns PEF. The removal of the extracellular Ca2+ slowed down the resealing, although did not prevent it. Recruitment of CHMP4B protein, a component of ESCRT-III complex, to the electroporated plasma membrane was not observed, thus providing no evidence for possible contribution of the macro-vesicle shedding mechanism. In contrast, silencing the AnxA5 gene impaired resealing and reduced the viability of nsPEF-treated cells. We conclude that Annexin V but not ESCRT-III was involved in the repair of HeLa cells permeabilized by 300-ns stimuli, but it was not the only and perhaps not the main repair mechanism.
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Affiliation(s)
- Claudia Muratori
- Frank Reidy Research Center for Bioelectrics, Old Dominion University, Norfolk, VA 23508, USA
| | - Giedre Silkuniene
- Frank Reidy Research Center for Bioelectrics, Old Dominion University, Norfolk, VA 23508, USA; Institute for Digestive Research, Lithuanian University of Health Sciences, 50161 Kaunas, Lithuania
| | - Peter A Mollica
- Department of Medical Diagnostics and Translational Sciences, Old Dominion University, Norfolk, VA, USA
| | - Andrei G Pakhomov
- Frank Reidy Research Center for Bioelectrics, Old Dominion University, Norfolk, VA 23508, USA
| | - Olga N Pakhomova
- Frank Reidy Research Center for Bioelectrics, Old Dominion University, Norfolk, VA 23508, USA.
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24
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李 伟, 谢 佳, 彭 莉, 魏 良, 王 双, 李 永. [Recent advances in external cardiac defibrillation techniques]. SHENG WU YI XUE GONG CHENG XUE ZA ZHI = JOURNAL OF BIOMEDICAL ENGINEERING = SHENGWU YIXUE GONGCHENGXUE ZAZHI 2020; 37:1095-1100. [PMID: 33369350 PMCID: PMC9929988 DOI: 10.7507/1001-5515.202003013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Indexed: 06/12/2023]
Abstract
As an important medical electronic equipment for the cardioversion of malignant arrhythmia such as ventricular fibrillation and ventricular tachycardia, cardiac external defibrillators have been widely used in the clinics. However, the resuscitation success rate for these patients is still unsatisfied. In this paper, the recent advances of cardiac external defibrillation technologies is reviewed. The potential mechanism of defibrillation, the development of novel defibrillation waveform, the factors that may affect defibrillation outcome, the interaction between defibrillation waveform and ventricular fibrillation waveform, and the individualized patient-specific external defibrillation protocol are analyzed and summarized. We hope that this review can provide helpful reference for the optimization of external defibrillator design and the individualization of clinical application.
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Affiliation(s)
- 伟明 李
- 陆军军医大学 生物医学工程与影像医学系(重庆 400038)Department of Biomedical Engineering and Imaging Medicine, Army Medical University, Chongqing 400038, P.R.China
| | - 佳玲 谢
- 陆军军医大学 生物医学工程与影像医学系(重庆 400038)Department of Biomedical Engineering and Imaging Medicine, Army Medical University, Chongqing 400038, P.R.China
| | - 莉 彭
- 陆军军医大学 生物医学工程与影像医学系(重庆 400038)Department of Biomedical Engineering and Imaging Medicine, Army Medical University, Chongqing 400038, P.R.China
| | - 良 魏
- 陆军军医大学 生物医学工程与影像医学系(重庆 400038)Department of Biomedical Engineering and Imaging Medicine, Army Medical University, Chongqing 400038, P.R.China
| | - 双卫 王
- 陆军军医大学 生物医学工程与影像医学系(重庆 400038)Department of Biomedical Engineering and Imaging Medicine, Army Medical University, Chongqing 400038, P.R.China
| | - 永勤 李
- 陆军军医大学 生物医学工程与影像医学系(重庆 400038)Department of Biomedical Engineering and Imaging Medicine, Army Medical University, Chongqing 400038, P.R.China
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25
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Caluori G, Odehnalova E, Jadczyk T, Pesl M, Pavlova I, Valikova L, Holzinger S, Novotna V, Rotrekl V, Hampl A, Crha M, Cervinka D, Starek Z. AC Pulsed Field Ablation Is Feasible and Safe in Atrial and Ventricular Settings: A Proof-of-Concept Chronic Animal Study. Front Bioeng Biotechnol 2020; 8:552357. [PMID: 33344428 PMCID: PMC7744788 DOI: 10.3389/fbioe.2020.552357] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Accepted: 11/09/2020] [Indexed: 12/18/2022] Open
Abstract
Introduction Pulsed field ablation (PFA) exploits the delivery of short high-voltage shocks to induce cells death via irreversible electroporation. The therapy offers a potential paradigm shift for catheter ablation of cardiac arrhythmia. We designed an AC-burst generator and therapeutic strategy, based on the existing knowledge between efficacy and safety among different pulses. We performed a proof-of-concept chronic animal trial to test the feasibility and safety of our method and technology. Methods We employed 6 female swine - weight 53.75 ± 4.77 kg - in this study. With fluoroscopic and electroanatomical mapping assistance, we performed ECG-gated AC-PFA in the following settings: in the left atrium with a decapolar loop catheter with electrodes connected in bipolar fashion; across the interventricular septum applying energy between the distal electrodes of two tip catheters. After procedure and 4-week follow-up, the animals were euthanized, and the hearts were inspected for tissue changes and characterized. We perform finite element method simulation of our AC-PFA scenarios to corroborate our method and better interpret our findings. Results We applied square, 50% duty cycle, AC bursts of 100 μs duration, 100 kHz internal frequency, 900 V for 60 pulses in the atrium and 1500 V for 120 pulses in the septum. The inter-burst interval was determined by the native heart rhythm - 69 ± 9 bpm. Acute changes in the atrial and ventricular electrograms were immediately visible at the sites of AC-PFA - signals were elongated and reduced in amplitude (p < 0.0001) and tissue impedance dropped (p = 0.011). No adverse event (e.g., esophageal temperature rises or gas bubble streams) was observed - while twitching was avoided by addition of electrosurgical return electrodes. The implemented numerical simulations confirmed the non-thermal nature of our AC-PFA and provided specific information on the estimated treated area and need of pulse trains. The postmortem chest inspection showed no peripheral damage, but epicardial and endocardial discolorations at sites of ablation. T1-weighted scans revealed specific tissue changes in atria and ventricles, confirmed to be fibrotic scars via trichrome staining. We found isolated, transmural and continuous scars. A surviving cardiomyocyte core was visible in basal ventricular lesions. Conclusion We proved that our method and technology of AC-PFA is feasible and safe for atrial and ventricular myocardial ablation, supporting their systematic investigation into effectiveness evaluation for the treatment of cardiac arrhythmia. Further optimization, with energy titration or longer follow-up, is required for a robust atrial and ventricular AC-PFA.
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Affiliation(s)
- Guido Caluori
- International Clinical Research Center, St. Anne's University Hospital Brno, Brno, Czechia.,IHU LIRYC, Electrophysiology and Heart Modeling Institute, Fondation Bordeaux Université, Pessac, France.,Univ. Bordeaux, INSERM, UMR 1045, Cardiothoracic Research Center of Bordeaux, Pessac, France
| | - Eva Odehnalova
- International Clinical Research Center, St. Anne's University Hospital Brno, Brno, Czechia
| | - Tomasz Jadczyk
- International Clinical Research Center, St. Anne's University Hospital Brno, Brno, Czechia.,Department of Cardiology and Structural Heart Diseases, Medical University of Silesia, Katowice, Poland
| | - Martin Pesl
- International Clinical Research Center, St. Anne's University Hospital Brno, Brno, Czechia.,Department of Biology, Faculty of Medicine, Masaryk University, Brno, Czechia.,First Department of Internal Medicine-Cardioangiology, St. Anne's University Hospital, Masaryk University, Brno, Czechia
| | - Iveta Pavlova
- Institute of Scientific Instruments of the Czech Academy of Sciences, Brno, Czechia
| | - Lucia Valikova
- Faculty of Veterinary Medicine, University of Veterinary and Pharmaceutical Sciences, Brno, Czechia
| | | | - Veronika Novotna
- International Clinical Research Center, St. Anne's University Hospital Brno, Brno, Czechia.,Department of Power Electrical and Electronic Engineering, Faculty of Electrical Engineering and Communication, Brno University of Technology, Brno, Czechia
| | - Vladimir Rotrekl
- International Clinical Research Center, St. Anne's University Hospital Brno, Brno, Czechia.,Department of Biology, Faculty of Medicine, Masaryk University, Brno, Czechia
| | - Ales Hampl
- International Clinical Research Center, St. Anne's University Hospital Brno, Brno, Czechia.,Department of Histology and Embryology, Faculty of Medicine, Masaryk University, Brno, Czechia
| | - Michal Crha
- Faculty of Veterinary Medicine, University of Veterinary and Pharmaceutical Sciences, Brno, Czechia
| | - Dalibor Cervinka
- Department of Power Electrical and Electronic Engineering, Faculty of Electrical Engineering and Communication, Brno University of Technology, Brno, Czechia
| | - Zdenek Starek
- International Clinical Research Center, St. Anne's University Hospital Brno, Brno, Czechia.,First Department of Internal Medicine-Cardioangiology, St. Anne's University Hospital, Masaryk University, Brno, Czechia
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26
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Maltsev AV, Kokoz YM. Cardiomyocytes generating spontaneous Ca2+-transients as tools for precise estimation of sarcoplasmic reticulum Ca2+ transport. Arch Biochem Biophys 2020; 693:108542. [DOI: 10.1016/j.abb.2020.108542] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Revised: 07/19/2020] [Accepted: 08/07/2020] [Indexed: 01/05/2023]
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27
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Pakhomov AG, Pakhomova ON. The interplay of excitation and electroporation in nanosecond pulse stimulation. Bioelectrochemistry 2020; 136:107598. [PMID: 32711366 DOI: 10.1016/j.bioelechem.2020.107598] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2020] [Revised: 07/09/2020] [Accepted: 07/10/2020] [Indexed: 12/11/2022]
Abstract
Conventional electric stimuli of micro- and millisecond duration excite or activate cells at voltages 10-100 times below the electroporation threshold. This ratio is remarkably different for nanosecond electric pulses (nsEP), which caused excitation and activation only at or above the electroporation threshold in diverse cell lines, primary cardiomyocytes, neurons, and chromaffin cells. Depolarization to the excitation threshold often results from (or is assisted by) the loss of the resting membrane potential due to ion leaks across the membrane permeabilized by nsEP. Slow membrane resealing and the build-up of electroporation damages prevent repetitive excitation by nsEP. However, peripheral nerves and muscles are exempt from this rule and withstand multiple cycles of excitation by nsEP without the loss of function or signs of electroporation. We show that the damage-free excitation by nsEP may be enabled by the membrane charging time constant sufficiently large to (1) cap the peak transmembrane voltage during nsEP below the electroporation threshold, and (2) extend the post-nsEP depolarization long enough to activate voltage-gated ion channels. The low excitatory efficacy of nsEP compared to longer pulses makes them advantageous for medical applications where the neuromuscular excitation is an unwanted side effect, such as electroporation-based cancer and tissue ablation.
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Affiliation(s)
- Andrei G Pakhomov
- Frank Reidy Research Center for Bioelectrics, Old Dominion University, Norfolk, VA 23508, USA.
| | - Olga N Pakhomova
- Frank Reidy Research Center for Bioelectrics, Old Dominion University, Norfolk, VA 23508, USA
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28
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Xiao S, Zou X, Huynh K, Yamada R, Petrella R, Bani Hani M, Beebe S. A High-Power Dielectric Biconical Antenna for Treatment of Subcutaneous Targets. Bioelectromagnetics 2020; 41:413-424. [PMID: 32533598 DOI: 10.1002/bem.22275] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2019] [Revised: 05/08/2020] [Accepted: 05/29/2020] [Indexed: 02/03/2023]
Abstract
A dielectric biconical antenna (DiBiCA) for radiating subnanosecond pulses to treat subcutaneous tissue was designed, constructed, and tested. It is composed of a conical wave launcher and truncated conical emitter. In between, there is a short cylinder that provides a space for a ring terminating resistor. The material of the antenna has a dielectric constant of 28, so its size is small (length: 7 cm and aperture diameter: 2.2 cm). It was housed in an oil container to withstand high voltages and avoid surface flashover. The radiated electric field, measured in water, increased as the input voltage increased up to 30 kV but leveled off for higher voltages up to 50 kV, presumably because of losses in the antenna dielectric. The maximum field was 1.5 kV/cm for a depth of 5 mm and 1.0 kV/cm for a depth of 20 mm. Although the dielectric loss mechanism remains to be investigated, the antenna can be useful for noninvasive delivery of subnanosecond pulses to induce biological responses on subcutaneous targets. The DiBiCA radiated pulses were shown to change the viabilities of dendritic cells and macrophages for 10-min exposure. Bioelectromagnetics. 2020;41:413-424. © 2020 Bioelectromagnetics Society.
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Affiliation(s)
- Shu Xiao
- Frank Reidy Research Center for Bioelectrics, Old Dominion University, Norfolk, Virginia.,Department of Electrical and Computer Engineering, Old Dominion University, Norfolk, Virginia
| | - Xianbing Zou
- National Key Laboratory of Communication, University of Electronic Science and Technology, Chengdu, China
| | - Khiem Huynh
- Department of Electrical and Computer Engineering, Old Dominion University, Norfolk, Virginia
| | - Ryo Yamada
- Graduate School, Kumamoto University, Kumamoto, Japan
| | - Ross Petrella
- Frank Reidy Research Center for Bioelectrics, Old Dominion University, Norfolk, Virginia
| | - Maisoun Bani Hani
- Frank Reidy Research Center for Bioelectrics, Old Dominion University, Norfolk, Virginia
| | - Stephen Beebe
- Frank Reidy Research Center for Bioelectrics, Old Dominion University, Norfolk, Virginia
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29
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Dermol-Černe J, Batista Napotnik T, Reberšek M, Miklavčič D. Short microsecond pulses achieve homogeneous electroporation of elongated biological cells irrespective of their orientation in electric field. Sci Rep 2020; 10:9149. [PMID: 32499601 PMCID: PMC7272635 DOI: 10.1038/s41598-020-65830-3] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2019] [Accepted: 04/27/2020] [Indexed: 12/21/2022] Open
Abstract
In gene electrotransfer and cardiac ablation with irreversible electroporation, treated muscle cells are typically of elongated shape and their orientation may vary. Orientation of cells in electric field has been reported to affect electroporation, and hence electrodes placement and pulse parameters choice in treatments for achieving homogeneous effect in tissue is important. We investigated how cell orientation influences electroporation with respect to different pulse durations (ns to ms range), both experimentally and numerically. Experimentally detected electroporation (evaluated separately for cells parallel and perpendicular to electric field) via Ca2+ uptake in H9c2 and AC16 cardiomyocytes was numerically modeled using the asymptotic pore equation. Results showed that cell orientation affects electroporation extent: using short, nanosecond pulses, cells perpendicular to electric field are significantly more electroporated than parallel (up to 100-times more pores formed), and with long, millisecond pulses, cells parallel to electric field are more electroporated than perpendicular (up to 1000-times more pores formed). In the range of a few microseconds, cells of both orientations were electroporated to the same extent. Using pulses of a few microseconds lends itself as a new possible strategy in achieving homogeneous electroporation in tissue with elongated cells of different orientation (e.g. electroporation-based cardiac ablation).
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Affiliation(s)
- Janja Dermol-Černe
- University of Ljubljana, Faculty of Electrical Engineering, Tržaška cesta 25, 1000, Ljubljana, Slovenia
| | - Tina Batista Napotnik
- University of Ljubljana, Faculty of Electrical Engineering, Tržaška cesta 25, 1000, Ljubljana, Slovenia
| | - Matej Reberšek
- University of Ljubljana, Faculty of Electrical Engineering, Tržaška cesta 25, 1000, Ljubljana, Slovenia
| | - Damijan Miklavčič
- University of Ljubljana, Faculty of Electrical Engineering, Tržaška cesta 25, 1000, Ljubljana, Slovenia.
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Probing Nanoelectroporation and Resealing of the Cell Membrane by the Entry of Ca 2+ and Ba 2+ Ions. Int J Mol Sci 2020; 21:ijms21093386. [PMID: 32403282 PMCID: PMC7247012 DOI: 10.3390/ijms21093386] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Revised: 05/07/2020] [Accepted: 05/08/2020] [Indexed: 12/11/2022] Open
Abstract
The principal bioeffect of the nanosecond pulsed electric field (nsPEF) is a lasting cell membrane permeabilization, which is often attributed to the formation of nanometer-sized pores. Such pores may be too small for detection by the uptake of fluorescent dyes. We tested if Ca2+, Cd2+, Zn2+, and Ba2+ ions can be used as nanoporation markers. Time-lapse imaging was performed in CHO, BPAE, and HEK cells loaded with Fluo-4, Calbryte, or Fluo-8 dyes. Ca2+ and Ba2+ did not change fluorescence in intact cells, whereas their entry after nsPEF increased fluorescence within <1 ms. The threshold for one 300-ns pulse was at 1.5–2 kV/cm, much lower than >7 kV/cm for the formation of larger pores that admitted YO-PRO-1, TO-PRO-3, or propidium dye into the cells. Ba2+ entry caused a gradual emission rise, which reached a stable level in 2 min or, with more intense nsPEF, kept rising steadily for at least 30 min. Ca2+ entry could elicit calcium-induced calcium release (CICR) followed by Ca2+ removal from the cytosol, which markedly affected the time course, polarity, amplitude, and the dose-dependence of fluorescence change. Both Ca2+ and Ba2+ proved as sensitive nanoporation markers, with Ba2+ being more reliable for monitoring membrane damage and resealing.
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31
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Hamada Y, Furumoto Y, Izutani A, Taniuchi S, Miyake M, Oyadomari M, Teranishi K, Shimomura N, Oyadomari S. Nanosecond pulsed electric fields induce the integrated stress response via reactive oxygen species-mediated heme-regulated inhibitor (HRI) activation. PLoS One 2020; 15:e0229948. [PMID: 32155190 PMCID: PMC7064201 DOI: 10.1371/journal.pone.0229948] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Accepted: 02/18/2020] [Indexed: 12/24/2022] Open
Abstract
The integrated stress response (ISR) is one of the most important cytoprotective mechanisms and is integrated by phosphorylation of the α subunit of eukaryotic translation initiation factor 2 (eIF2α). Four eIF2α kinases, heme-regulated inhibitor (HRI), double-stranded RNA-dependent protein kinase (PKR), PKR-like endoplasmic reticulum kinase (PERK), and general control nonderepressible 2 (GCN2), are activated in response to several stress conditions. We previously reported that nanosecond pulsed electric fields (nsPEFs) are a potential therapeutic tool for ISR activation. In this study, we examined which eIF2α kinase is activated by nsPEF treatment. To assess the responsible eIF2α kinase, we used previously established eIF2α kinase quadruple knockout (4KO) and single eIF2α kinase-rescued 4KO mouse embryonic fibroblast (MEF) cells. nsPEFs 70 ns in duration with 30 kV/cm electric fields caused eIF2α phosphorylation in wild-type (WT) MEF cells. On the other hand, nsPEF-induced eIF2α phosphorylation was completely abolished in 4KO MEF cells and was recovered by HRI overexpression. CM-H2DCFDA staining showed that nsPEFs generated reactive oxygen species (ROS), which activated HRI. nsPEF-induced eIF2α phosphorylation was blocked by treatment with the ROS scavenger N-acetyl-L-cysteine (NAC). Our results indicate that the eIF2α kinase HRI is responsible for nsPEF-induced ISR activation and is activated by nsPEF-generated ROS.
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Affiliation(s)
- Yoshimasa Hamada
- Division of Molecular Biology, Institute for Genome Research, Institute of Advanced Medical Sciences, Tokushima University, Tokushima, Japan
- Fujii Memorial Institute of Medical Sciences, Institute of Advanced Medical Sciences, Tokushima University, Tokushima, Japan
| | - Yuji Furumoto
- Institute of Technology and Science, Tokushima University, Tokushima, Japan
| | - Akira Izutani
- Institute of Technology and Science, Tokushima University, Tokushima, Japan
| | - Shusuke Taniuchi
- Division of Molecular Biology, Institute for Genome Research, Institute of Advanced Medical Sciences, Tokushima University, Tokushima, Japan
- Fujii Memorial Institute of Medical Sciences, Institute of Advanced Medical Sciences, Tokushima University, Tokushima, Japan
- Department of Molecular Physiology, Diabetes Therapeutics and Research Center, Institute of Advanced Medical Sciences, Tokushima University, Tokushima, Japan
| | - Masato Miyake
- Division of Molecular Biology, Institute for Genome Research, Institute of Advanced Medical Sciences, Tokushima University, Tokushima, Japan
- Fujii Memorial Institute of Medical Sciences, Institute of Advanced Medical Sciences, Tokushima University, Tokushima, Japan
- Department of Molecular Physiology, Diabetes Therapeutics and Research Center, Institute of Advanced Medical Sciences, Tokushima University, Tokushima, Japan
| | - Miho Oyadomari
- Division of Molecular Biology, Institute for Genome Research, Institute of Advanced Medical Sciences, Tokushima University, Tokushima, Japan
| | - Kenji Teranishi
- Institute of Technology and Science, Tokushima University, Tokushima, Japan
| | - Naoyuki Shimomura
- Institute of Technology and Science, Tokushima University, Tokushima, Japan
| | - Seiichi Oyadomari
- Division of Molecular Biology, Institute for Genome Research, Institute of Advanced Medical Sciences, Tokushima University, Tokushima, Japan
- Fujii Memorial Institute of Medical Sciences, Institute of Advanced Medical Sciences, Tokushima University, Tokushima, Japan
- Department of Molecular Physiology, Diabetes Therapeutics and Research Center, Institute of Advanced Medical Sciences, Tokushima University, Tokushima, Japan
- * E-mail:
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32
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Neuber JU, Varghese F, Pakhomov AG, Zemlin CW. Using Nanosecond Shocks for Cardiac Defibrillation. Bioelectricity 2019; 1:240-246. [PMID: 32685917 DOI: 10.1089/bioe.2019.0030] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
The purpose of this review article is to summarize our current understanding of the efficacy and safety of cardiac defibrillation with nanosecond shocks. Experiments in isolated hearts, using optical mapping of the electrical activity, have demonstrated that nanosecond shocks can defibrillate with lower energies than conventional millisecond shocks. Single defibrillation strength nanosecond shocks do not cause obvious damage, but repeated stimulation leads to deterioration of the hearts. In isolated myocytes, nanosecond pulses can also stimulate at lower energies than at longer pulses and cause less electroporation (propidium uptake). The mechanism is likely electroporation of the plasma membrane. Repeated stimulation leads to distorted calcium gradients.
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Affiliation(s)
- Johanna U Neuber
- Frank Reidy Research Center for Bioelectrics, Old Dominion University, Norfolk, Virginia.,Department of Electrical and Computer Engineering, Old Dominion University, Norfolk, Virginia
| | - Frency Varghese
- Department of Medicine, University of Massachusetts Medical School, Worcester, Massachusetts
| | - Andrei G Pakhomov
- Frank Reidy Research Center for Bioelectrics, Old Dominion University, Norfolk, Virginia
| | - Christian W Zemlin
- Frank Reidy Research Center for Bioelectrics, Old Dominion University, Norfolk, Virginia.,Department of Electrical and Computer Engineering, Old Dominion University, Norfolk, Virginia
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33
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Antoneli PC, Goulart JT, Bonilha I, de Carvalho DD, de Oliveira PX. Heart defibrillation: relationship between pacing threshold and defibrillation probability. Biomed Eng Online 2019; 18:96. [PMID: 31519192 PMCID: PMC6743100 DOI: 10.1186/s12938-019-0715-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2019] [Accepted: 09/03/2019] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Considering the clinical importance of the ventricular fibrillation and that the most used therapy to reverse it has a critical side effect on the cardiac tissue, it is desirable to optimize defibrillation parameters to increase its efficiency. In this study, we investigated the influence of stimuli duration on the relationship between pacing threshold and defibrillation probability. RESULTS We found out that 0.5-ms-long pulses had a lower ratio of defibrillation probability to the pacing threshold, although the higher the pulse duration the lower is the electric field intensity required to defibrillate the hearts. CONCLUSION The appropriate choice of defibrillatory shock parameters is able to increase the efficiency of the defibrillation improving the survival chances after the occurrence of a severe arrhythmia. The relationship between pulse duration and the probability of reversal of fibrillation shows that this parameter cannot be underestimated in defibrillator design since different pulse durations have different levels of safety.
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Affiliation(s)
- Priscila C Antoneli
- Department of Biomedical Engineering, School of Electrical and Computer Engineering-FEEC, University of Campinas-UNICAMP, Rua Alexander Fleming 163, Cidade Universitária Zeferino Vaz, Campinas, SP, CEP 13083-881, Brazil
| | - Jair T Goulart
- Department of Physiological Sciences, Institute of Biology, University of Brasilia-UnB, Campus Universitário Darcy Ribeiro-Asa Norte, Brasília, DF, CEP 70910-900, Brazil
| | - Isabella Bonilha
- Laboratory of Myocardial Ischemia/Reperfusion, Faculty of Medical Science, University of Campinas-UNICAMP, Rua Cinco de Junho, 350, Bloco 1, Cidade Universitária Zeferino Vaz, Campinas, SP, CEP 13083-877, Brazil
| | - Daniela D de Carvalho
- Laboratory of Myocardial Ischemia/Reperfusion, Faculty of Medical Science, University of Campinas-UNICAMP, Rua Cinco de Junho, 350, Bloco 1, Cidade Universitária Zeferino Vaz, Campinas, SP, CEP 13083-877, Brazil
| | - Pedro X de Oliveira
- Department of Biomedical Engineering, School of Electrical and Computer Engineering-FEEC, University of Campinas-UNICAMP, Rua Alexander Fleming 163, Cidade Universitária Zeferino Vaz, Campinas, SP, CEP 13083-881, Brazil. .,Center for Biomedical Engineering, University of Campinas-UNICAMP, Rua Alexander Fleming 163, Cidade Universitária Zeferino Vaz, Campinas, SP, CEP 13083-881, Brazil.
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34
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Excitation and electroporation by MHz bursts of nanosecond stimuli. Biochem Biophys Res Commun 2019; 518:759-764. [PMID: 31472962 DOI: 10.1016/j.bbrc.2019.08.133] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2019] [Accepted: 08/23/2019] [Indexed: 12/16/2022]
Abstract
Intense nanosecond pulsed electric field (nsPEF) is a novel modality for cell activation and nanoelectroporation. Applications of nsPEF in research and therapy are hindered by a high electric field requirement, typically from 1 to over 50 kV/cm to elicit any bioeffects. We show how this requirement can be overcome by engaging temporal summation when pulses are compressed into high-rate bursts (up to several MHz). This approach was tested for excitation of ventricular cardiomyocytes and peripheral nerve fibers; for membrane electroporation of cardiomyocytes, CHO, and HEK cells; and for killing EL-4 cells. MHz compression of nsPEF bursts (100-1000 pulses) enables excitation at only 0.01-0.15 kV/cm and electroporation already at 0.4-0.6 kV/cm. Clear separation of excitation and electroporation thresholds allows for multiple excitation cycles without membrane disruption. The efficiency of nsPEF bursts increases with the duty cycle (by increasing either pulse duration or repetition rate) and with increasing the total time "on" (by increasing either pulse duration or number). For some endpoints, the efficiency of nsPEF bursts matches a single "long" pulse whose amplitude and duration equal the time-average amplitude and duration of the bursts. For other endpoints this rule is not valid, presumably because of nsPEF-specific bioeffects and/or possible modification of targets already during the burst. MHz compression of nsPEF bursts is a universal and efficient way to lower excitation thresholds and facilitate electroporation.
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35
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Nanosecond pulsed electric fields induce extracellular release of chromosomal DNA and histone citrullination in neutrophil-differentiated HL-60 cells. Sci Rep 2019; 9:8451. [PMID: 31186478 PMCID: PMC6559984 DOI: 10.1038/s41598-019-44817-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2019] [Accepted: 05/22/2019] [Indexed: 12/17/2022] Open
Abstract
Nanosecond pulsed electric fields (nsPEFs) have gained attention as a novel physical stimulus for life sciences. Although cancer therapy is currently their promising application, nsPEFs have further potential owing to their ability to elicit various cellular responses. This study aimed to explore stimulatory actions of nsPEFs, and we used HL-60 cells that were differentiated into neutrophils under cultured conditions. Exposure of neutrophil-differentiated HL-60 cells to nsPEFs led to the extracellular release of chromosomal DNA, which appears to be equivalent to neutrophil extracellular traps (NETs) that serve as a host defense mechanism against pathogens. Fluorometric measurement of extracellular DNA showed that DNA extrusion was rapidly induced after nsPEF exposure and increased over time. Western blot analysis demonstrated that nsPEFs induced histone citrullination that is the hydrolytic conversion of arginine to citrulline on histones and facilitates chromatin decondensation. DNA extrusion and histone citrullination by nsPEFs were cell type-specific and Ca2+-dependent events. Taken together, these observations suggest that nsPEFs drive the mechanism for neutrophil-specific immune response without infection, highlighting a novel aspect of nsPEFs as a physical stimulus.
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36
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Ning T, Guo J, Zhang K, Li K, Zhang J, Yang Z, Ge Z. Nanosecond pulsed electric fields enhanced chondrogenic potential of mesenchymal stem cells via JNK/CREB-STAT3 signaling pathway. Stem Cell Res Ther 2019; 10:45. [PMID: 30678730 PMCID: PMC6346554 DOI: 10.1186/s13287-019-1133-0] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2018] [Revised: 12/26/2018] [Accepted: 01/03/2019] [Indexed: 12/27/2022] Open
Abstract
Background Nanosecond pulsed electric fields (nsPEFs) can produce more significant biological effects than traditional electric fields and have thus attracted rising attention in developing medical applications based on short pulse duration and high field strength, such as effective cancer therapy. However, little is known about their effects on the differentiation of stem cells. Furthermore, mechanisms of electric fields on chondrogenic differentiation of mesenchymal stem cells (MSCs) remain elusive, and effects of electric fields on cartilage regeneration need to be verified in vivo. Here, we aimed to study the effects of nsPEFs on chondrogenic differentiation of MSCs in vitro and in vivo and further to explore the mechanisms behind the phenomenon. Methods The effects of nsPEF-preconditioning on chondrogenic differentiation of mesenchymal stem cells (MSCs) in vitro were evaluated using cell viability, gene expression, glycosaminoglycan (sGAG) content, and histological staining, as well as in vivo cartilage regeneration in osteochondral defects of rats. Signaling pathways were investigated with protein expression and gene expression, respectively. Results nsPEF-preconditioning with proper parameters (10 ns at 20 kV/cm, 100 ns at 10 kV/cm) significantly potentiated chondrogenic differentiation capacity of MSCs with upregulated cartilaginous gene expression and increased matrix deposition through activation of C-Jun NH2-terminal kinase (JNK) and cAMP-response element binding protein (CREB), followed by activation of downstream signal transducer and activator of transcription (STAT3). Implantation of nsPEF-preconditioned MSCs significantly enhanced cartilage regeneration in vivo, compared with implantation of non-nsPEF-preconditioned MSCs. Conclusion This study demonstrates a unique approach of nsPEF treatment to potentiate the chondrogenic ability of MSCs through activation of JNK/CREB-STAT3 that could have translational potential for MSC-based cartilage regeneration. Electronic supplementary material The online version of this article (10.1186/s13287-019-1133-0) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Tong Ning
- , Peking-Tsinghua Center for Life Sciences, Beijing, 100871, China.,Department of Biomedical Engineering, College of Engineering, Peking University, Beijing, 100871, China.,Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, 100871, China
| | - Jinsong Guo
- Institute of Biomechanics and Biomedical Engineering, College of Engineering, Peking University, Beijing, 100871, China
| | - Kun Zhang
- Department of Biomedical Engineering, College of Engineering, Peking University, Beijing, 100871, China
| | - Kejia Li
- Department of Biomedical Engineering, College of Engineering, Peking University, Beijing, 100871, China
| | - Jue Zhang
- Institute of Biomechanics and Biomedical Engineering, College of Engineering, Peking University, Beijing, 100871, China. .,Center for BioMed-X Research, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, 100871, China.
| | - Zheng Yang
- Tissue Engineering Program, Life Sciences Institute, National University of Singapore, 27 Medical Drive, Singapore, 117510, Singapore
| | - Zigang Ge
- Department of Biomedical Engineering, College of Engineering, Peking University, Beijing, 100871, China.
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37
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Azarov JE, Semenov I, Casciola M, Pakhomov AG. Excitation of murine cardiac myocytes by nanosecond pulsed electric field. J Cardiovasc Electrophysiol 2019; 30:392-401. [PMID: 30582656 DOI: 10.1111/jce.13834] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/14/2018] [Revised: 12/18/2018] [Accepted: 12/21/2018] [Indexed: 01/26/2023]
Abstract
INTRODUCTION Opening of voltage-gated sodium channels takes tens to hundreds of microseconds, and mechanisms of their opening by nanosecond pulsed electric field (nsPEF) stimuli remain elusive. This study was aimed at uncovering the mechanisms of how nsPEF elicits action potentials (APs) in cardiomyocytes. METHODS AND RESULTS Fluorescent imaging of optical APs (FluoVolt) and Ca2+ -transients (Fluo-4) was performed in enzymatically isolated murine ventricular cardiomyocytes stimulated by 200-nanosecond trapezoidal pulses. nsPEF stimulation evoked tetrodotoxin-sensitive APs accompanied or preceded by slow sustained depolarization (SSD) and, in most cells, by transient afterdepolarization waves. SSD threshold was lower than the AP threshold (1.26 ± 0.03 vs 1.34 ± 0.03 kV/cm, respectively, P < 0.001). Inhibition of l-type calcium and sodium-calcium exchanger currents reduced the SSD amplitude and increased the AP threshold ( P < 0.05). The threshold for Ca 2+ -transients (1.40 ± 0.04 kV/cm) was not significantly affected by a tetrodotoxin-verapamil cocktail, suggesting the activation of a Ca 2+ entry pathway independent from the opening of Na + or Ca 2+ voltage-gated channels. Removal of external Ca 2+ decreased the SSD amplitude ( P = 0.004) and blocked Ca 2+ -transients but not APs. The incidence of transient afterdepolarization waves was decreased by verapamil and by removal of external Ca 2+ ( P = 0.002). CONCLUSIONS The study established that nsPEF stimulation caused calcium entry into cardiac myocytes (including routes other than voltage-gated calcium channels) and SSD. Tetrodotoxin-sensitive APs were mediated by SSD, whose amplitude depended on the calcium entry. Plasma membrane electroporation was the most likely primary mechanism of SSD with additional contribution from l-type calcium and sodium-calcium exchanger currents.
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Affiliation(s)
- Jan E Azarov
- Frank Reidy Research Center for Bioelectrics, Old Dominion University, Norfolk, Virginia.,Laboratory of Cardiac Physiology, Institute of Physiology, Komi Science Center, Ural Branch, Russian Academy of Sciences, Syktyvkar, Russia.,Department of Physiology, Medical Institute of Pitirim Sorokin Syktyvkar State University, Syktyvkar, Russia
| | - Iurii Semenov
- Frank Reidy Research Center for Bioelectrics, Old Dominion University, Norfolk, Virginia
| | - Maura Casciola
- Frank Reidy Research Center for Bioelectrics, Old Dominion University, Norfolk, Virginia
| | - Andrei G Pakhomov
- Frank Reidy Research Center for Bioelectrics, Old Dominion University, Norfolk, Virginia
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38
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Expression of voltage-gated calcium channels augments cell susceptibility to membrane disruption by nanosecond pulsed electric field. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2018; 1860:2175-2183. [PMID: 30409513 DOI: 10.1016/j.bbamem.2018.08.017] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2018] [Revised: 08/29/2018] [Accepted: 08/30/2018] [Indexed: 12/15/2022]
Abstract
We compared membrane permeabilization by nanosecond pulsed electric field (nsPEF) in HEK293 cells with and without assembled CaV1.3 L-type voltage-gated calcium channel (VGCC). Individual cells were subjected to one 300-ns pulse at 0 (sham exposure); 1.4; 1.8; or 2.3 kV/cm, and membrane permeabilization was evaluated by measuring whole-cell currents and by optical monitoring of cytosolic Ca2+. nsPEF had either no effect (0 and 1.4 kV/cm), or caused a lasting (>80 s) increase in the membrane conductance in about 50% of cells (1.8 kV/cm), or in all cells (2.3 kV/cm). The conductance pathway opened by nsPEF showed strong inward rectification, with maximum conductance increase for the inward current at the most negative membrane potentials. Although these potentials were below the depolarization threshold for VGCC activation, the increase in conductance in cells which expressed VGCC (VGCC+ cells) was about twofold greater than in cells which did not (VGCC- cells). Among VGCC+ cells, the nsPEF-induced increase in membrane conductance showed a positive correlation with the amplitude of VGCC current measured in the same cells prior to nsPEF exposure. These findings demonstrate that the expression of VGCC makes cells more susceptible to membrane permeabilization by nsPEF. Time-lapse imaging of nsPEF-induced Ca2+ transients confirmed permeabilization by a single 300-ns pulse at 1.8 or 2.3 kV/cm, but not at 1.4 kV/cm, and the transients were expectedly larger in VGCC+ cells. However, it remains to be established whether larger transients reflected additional Ca2+ entry through VGCC, or were a result of more severe electropermeabilization of VGCC+ cells.
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