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Funken M, Knappe V, Beiert T, Nickenig G, Sasse P, Schrickel JW. TLR4 pathway induces proarrhythmogenic slow conduction by impaired depolarisation. Eur Heart J 2022. [DOI: 10.1093/eurheartj/ehac544.2977] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Abstract
Background
Cardiac inflammation driven by the Toll-Like-Receptor 4 (TLR4) is correlated to increased risk of arrhythmia. Cardiac arrhythmogenesis and the formation of re-entry tachycardia is highly dependent on conduction velocity (CV) and action potential (AP) duration (APD). As TLR4 induced APD shortening has been shown, we analyze in this study for the first time the TLR4 effect on conductance disturbances in a LPS induced septic mouse model.
Methods
Systemic activation of TLR4 in mice was achieved by intraperitoneal LPS injection 3.5 hours prior to experiments. In vivo electrophysiological investigation (EPI) was performed using an octapolar transvenous catheter placed to the right heart. Ex vivo experiments were performed on Langendorff-perfused hearts. AP propagation was measured by optical voltage mapping (OVM) with voltage sensitive dye Di-4-ANEPPS. For AP analysis including RMP, intracellular electrical recordings were performed using sharp microelectrodes. Wildtype mice after LPS injection were compared to wildtype mice after vehicle (NaCl) injection or ubiquitous TLR4 knockout (TLR4−/−) mice with LPS or vehicle application.
Results
In vivo EPI showed a tendency to more atrial fibrillation after LPS injection (+LPS 5/6, +NaCl 2/6, p=0.2). Ventricular stimulation evoked ventricular tachycardia in every LPS treated WT mouse but less in controls (+LPS 6/6, +NaCl 1/6, p=0.01). OVM measured decreased CV in both atria and ventricle after LPS treatment (atria: +LPS: 43.1±3.1cm/s, n=5; +NaCl: 72.6±9.8cm/s, n=10, p=0.04; ventricle: +LPS: 50.2±2.2cm/s, n=6; +NaCl: 67.7±5.0cm/s, n=10, p=0.02). In analysis of AP in atria upstroke velocity was slightly decreased (max.dV/dt: +LPS: 123.1±4.8V/s, n=22; +NaCl: 158.5±5.3V/s, n=39, p=0.04) but highly reduced in ventricle (max.dV/dt: +LPS: 91.8±3.6V/s, n=27; +NaCl: 140.7±6.3V/s, n=35, p<0.0001). RMP in atria was depolarised after LPS injection (+LPS: −70.1±1.9mV, n=22; +NaCl: −81.1±1.2mV, n=39, p=0.004) explaining decreased upstroke velocity and CV slowing in atria by voltage-dependent Na+ channel inactivation. Ventricular RMP was unaffected by LPS injection (+LPS: −75.1±1.1mV, n=44; +NaCl: −76.3±0.9mV, n=55, p=0.83). Therefore the Na+ currents were measured in isolated ventricular cardiomyocytes using whole cell patch clamp revealing the maximum Na+ current density lowered after LPS treatment (+LPS: −20.6±1.7 pA/pF, n=16, +NaCl 27.1±2.6 pA/pF, n=10, p=0.03). LPS did not affect EPI, CV, upstroke velocity or current density in TLR4−/− mice.
Conclusion
Herein we report for the first time impaired cardiac depolarisation and conduction after short term activation of TLR4 in vivo. Pro arrhythmogenic mechanisms differ in atria and ventricle: Increased atrial RMP inactivates Na+ current leading to reduction of CV. Ventricular slow CV is caused by reduced current density of Na+ channels. This different TLR4 effect might be important for novel antiarrhythmic and antiinflammatory applications.
Funding Acknowledgement
Type of funding sources: Public grant(s) – National budget only. Main funding source(s): GEROK-grant, University Bonn
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Affiliation(s)
- M Funken
- Heartcenter Bonn, University Hospital Bonn , Bonn , Germany
| | - V Knappe
- Heartcenter Bonn, University Hospital Bonn , Bonn , Germany
| | - T Beiert
- Heartcenter Bonn, University Hospital Bonn , Bonn , Germany
| | - G Nickenig
- Heartcenter Bonn, University Hospital Bonn , Bonn , Germany
| | - P Sasse
- University of Bonn, Institute of Physiology I , Bonn , Germany
| | - J W Schrickel
- Heartcenter Bonn, University Hospital Bonn , Bonn , Germany
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Wagdi A, Malan D, Beauchamp JS, Narayanan UBS, Dusend V, Sasse P, Bruegmann T. OPN5 a new optogenetic receptor to study Gq signalling in the heart with light. Europace 2021. [DOI: 10.1093/europace/euab116.574] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Abstract
Funding Acknowledgements
Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Deutsche Forschungsgemeinschaft (DFG) Deutsche Zentrum für Herz-Kreislauf-Forschung (DZHK)
Background
Gq signalling plays an imperative role in cardiac physiology as well as pathophysiologies such as arrhythmias, hypertrophy, and heart failure. However, the underlying kinetics and the transition from physiological to pathological signalling is yet to be investigated. Optogenetics provides an unprecedented spatial and temporal precision as well as cell specificity, but up to now, selective control of Gq signalling in the intact heart with light has not been achieved.
Aim
To prove the potential of human Neuropsin (OPN5) to selectively control Gq signalling in the adult heart.
Methods
The biophysical behaviour of OPN5 in HEK293 cells was characterized by measuring IP1 accumulation, Ca2+ imaging, and patch-clamp analysis of GIRK current activity. We generated a new transgenic mouse model expressing OPN5 in fusion with eYFP under the control of the chicken-β-actin promotor and analysed the expression pattern in the whole heart after tissue clearing with light sheet microscopy and the expression rate after single cell dissociation. Adult isolated cardiomyocytes were examined to measure the effect of OPN5 activation on contractility with a novel custom-made software for on-line contraction analysis by pixel tracking. In Langendorff-perfused hearts, illumination of the sinus node region with UV light (385 nm, 10 s, 1 mW/mm2) was used to measure the influence on the heart rate in electrogram recordings. The light-induced effects and basal ECG parameters as well as the heart-weight-to-femur-length ratio of OPN5 hearts were compared to hearts from non-expressing siblings as well as from CD1 wild-type.
Results
We prove the selective activation of the Gq proteins by UV light-induced increase in IP3 production and induction of Ca2+ transients in HEK293 cells because both effects were abolished after applying the Gq protein specific blocker FR900359. Promiscuous activation of Gi proteins was excluded by light-induced inhibition of GIRK channels instead of activation. Within two different mouse lines, we found an OPN5/eYFP expression rate of ∼70% within the cardiomyocytes targeted to the plasmamembrane. UV light induced a significant increase in contraction velocity in ventricular cardiomyocytes, and this effect could be abolished by blocking Gq proteins. In the right atrium HCN4 positive sinus nodal cells expressed OPN5/ eYFP and illumination of this region resulted in OPN5 expressing hearts in an average increase of 5.9 ± 0.97% (n= 20, in founder line 1) in the heart rate, which was significant lager than control hearts (all groups <2.4% increase, n≥17). Importantly we could not find any differences in basal ECG parameters or the heart weight-to-femur-length between OPN5 expressing and control.
Conclusion
We herein prove the specificity of OPN5 for Gq protein activation and demonstrate its use in cardiomyocytes as well as the whole heart. Thus OPN5 is the first optogenetic tool allowing to control Gq signalling in the whole heart precisely.
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Affiliation(s)
- A Wagdi
- University Medical Center of Gottingen (UMG), Institute for Cardiovascular Physiology, Goettingen, Germany
| | - D Malan
- University of Bonn, Institute of Physiology, Bonn, Germany
| | - JS Beauchamp
- University Medical Center of Gottingen (UMG), Institute for Cardiovascular Physiology, Goettingen, Germany
| | - U BS Narayanan
- University Medical Center of Gottingen (UMG), Institute for Cardiovascular Physiology, Goettingen, Germany
| | - V Dusend
- University of Bonn, Institute of Physiology, Bonn, Germany
| | - P Sasse
- University of Bonn, Institute of Physiology, Bonn, Germany
| | - T Bruegmann
- University Medical Center of Gottingen (UMG), Institute for Cardiovascular Physiology, Goettingen, Germany
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Bader A, Brodarac A, Hetzer R, Kurtz A, Stamm C, Baraki H, Kensah G, Asch S, Rojas S, Martens A, Gruh I, Haverich A, Kutschka I, Cortes-Dericks L, Froment L, Kocher G, Schmid RA, Delyagina E, Schade A, Scharfenberg D, Skorska A, Lux C, Li W, Steinhoff G, Drey F, Lepperhof V, Neef K, Fatima A, Wittwer T, Wahlers T, Saric T, Choi YH, Fehrenbach D, Lehner A, Herrmann F, Hollweck T, Pfeifer S, Wintermantel E, Kozlik-Feldmann R, Hagl C, Akra B, Gyongyosi M, Zimmermann M, Pavo N, Mildner M, Lichtenauer M, Maurer G, Ankersmit J, Hacker S, Mittermayr R, Mildner M, Haider T, Nickl S, Zimmermann M, Beer L, Lebherz-Eichinger D, Schweiger T, Mitterbauer A, Keibl C, Werba G, Frey M, Ankersmit HJ, Herrmann S, Lux CA, Steinhoff G, Holfeld J, Tepekoylu C, Wang FS, Kozaryn R, Schaden W, Grimm M, Wang CJ, Holfeld J, Tepekoylu C, Kozaryn R, Urbschat A, Zacharowski K, Grimm M, Paulus P, Avaca MJ, Kempf H, Malan D, Sasse P, Fleischmann B, Palecek J, Drager G, Kirschning A, Zweigerdt R, Martin U, Katsirntaki K, Haller R, Ulrich S, Sgodda M, Puppe V, Duerr J, Schmiedl A, Ochs M, Cantz T, Mall M, Martin U, Mauritz C, Kensah G, Lara AR, Dahlmann J, Zweigerdt R, Schwanke K, Hegermann J, Skvorc D, Gawol A, Azizian A, Wagner S, Krause A, Drager G, Ochs M, Haverich A, Gruh I, Martin U, Klopsch C, Gaebel R, Kaminski A, Chichkov B, Jockenhoevel S, Steinhoff G, Klose K, Roy R, Brodarac A, Kang KS, Bieback K, Nasseri B, Choi YH, Kurtz A, Stamm C, Lepperhof V, Polchynska O, Kruttwig K, Bruggemann C, Xu G, Drey F, Neef K, Saric T, Lichtenauer M, Werba G, Mildner M, Baumgartner A, Hasun M, Nickl S, Beer L, Mitterbauer A, Zimmermann M, Gyongyosi M, Podesser BK, Ankersmit HJ, Ludwig M, Tolk A, Skorska A, Noack T, Steinhoff G, Margaryan R, Assanta N, Menciassi A, Burchielli S, Matteucci M, Lionetti V, Luchi C, Cariati E, Coceani F, Murzi B, Martens A, Rojas SV, Kensah G, Rotarmel A, Baraki H, Haverich A, Martin U, Gruh I, Kutschka I, Nasseri BA, Klose K, Ebell W, Dandel M, Kukucka M, Gebker R, Choi YH, Hetzer R, Stamm C, Paulus P, Holfeld J, Urbschat A, Mutlak H, Ockelmann P, Tacke S, Zacharowski K, Scheller B, Pereszlenyi A, Rojas SV, Martens A, Baraki H, Schwanke K, Zweigerdt R, Martin U, Haverich A, Kutschka I, Rojas SV, Martens A, Meier M, Baraki H, Schecker N, Rathert C, Zweigerdt R, Martin U, Haverich A, Kutschka I, Roy R, Brodarac A, Kukucka M, Kurtz A, Becher PM, Choi YH, Drori-Carmi N, Bercovich N, Zahavi-Goldstein E, Jack M, Netzer N, Pinzur L, Chajut A, Tschope C, Stamm C, Ruch U, Kaminski A, Strauer BE, Tiedemann G, Steinhoff G, Schade A, Delyagina E, Scharfenberg D, Lux C, Steinhoff G, Schlegel F, Dhein S, Akhavuz O, Mohr FW, Dohmen PM, Schlegel F, Salameh A, Oelmann K, Kiefer P, Dhein S, Mohr FW, Dohmen PM, Schwanke K, Merkert S, Templin C, Jara-Avaca M, Muller S, Haverich A, Martin U, Zweigerdt R, Skorska A, von Haehling S, Ludwig M, Slavic S, Curato C, Altarche-Xifro W, Unger T, Steinhoff G, Li J, Zhang Y, Li WZ, Ou L, Lux CA, Ma N, Steinhoff G, Haase A, Alt R, Schwanke K, Martin U. 3rd EACTS Meeting on Cardiac and Pulmonary Regeneration Berlin-Brandenburgische Akademie, Berlin, Germany, 14-15 December 2012. Interact Cardiovasc Thorac Surg 2013. [DOI: 10.1093/icvts/ivs561] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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