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Kaiser E, Tian Q, Wagner M, Barth M, Xian W, Schröder L, Ruppenthal S, Kaestner L, Boehm U, Wartenberg P, Lu H, McMillin SM, Bone DBJ, Wess J, Lipp P. DREADD technology reveals major impact of Gq signalling on cardiac electrophysiology. Cardiovasc Res 2020; 115:1052-1066. [PMID: 30321287 DOI: 10.1093/cvr/cvy251] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/20/2017] [Revised: 06/02/2018] [Accepted: 10/11/2018] [Indexed: 02/04/2023] Open
Abstract
AIMS Signalling via Gq-coupled receptors is of profound importance in many cardiac diseases such as hypertrophy and arrhythmia. Nevertheless, owing to their widespread expression and the inability to selectively stimulate such receptors in vivo, their relevance for cardiac function is not well understood. We here use DREADD technology to understand the role of Gq-coupled signalling in vivo in cardiac function. METHODS AND RESULTS We generated a novel transgenic mouse line that expresses a Gq-coupled DREADD (Dq) in striated muscle under the control of the muscle creatine kinase promotor. In vivo injection of the DREADD agonist clozapine-N-oxide (CNO) resulted in a dose-dependent, rapid mortality of the animals. In vivo electrocardiogram data revealed severe cardiac arrhythmias including lack of P waves, atrioventricular block, and ventricular tachycardia. Following Dq activation, electrophysiological malfunction of the heart could be recapitulated in the isolated heart ex vivo. Individual ventricular and atrial myocytes displayed a positive inotropic response and arrhythmogenic events in the absence of altered action potentials. Ventricular tissue sections revealed a strong co-localization of Dq with the principal cardiac connexin CX43. Western blot analysis with phosphor-specific antibodies revealed strong phosphorylation of a PKC-dependent CX43 phosphorylation site following CNO application in vivo. CONCLUSION Activation of Gq-coupled signalling has a major impact on impulse generation, impulse propagation, and coordinated impulse delivery in the heart. Thus, Gq-coupled signalling does not only modulate the myocytes' Ca2+ handling but also directly alters the heart's electrophysiological properties such as intercellular communication. This study greatly advances our understanding of the plethora of modulatory influences of Gq signalling on the heart in vivo.
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Affiliation(s)
- Elisabeth Kaiser
- Center for Molecular Signaling (PZMS), Institute for Molecular Cell Biology; Medical Faculty, Saarland University, Homburg, Germany
| | - Qinghai Tian
- Center for Molecular Signaling (PZMS), Institute for Molecular Cell Biology; Medical Faculty, Saarland University, Homburg, Germany
| | - Michael Wagner
- Center for Molecular Signaling (PZMS), Institute for Molecular Cell Biology; Medical Faculty, Saarland University, Homburg, Germany
| | - Monika Barth
- Center for Molecular Signaling (PZMS), Institute for Molecular Cell Biology; Medical Faculty, Saarland University, Homburg, Germany
| | - Wenying Xian
- Center for Molecular Signaling (PZMS), Institute for Molecular Cell Biology; Medical Faculty, Saarland University, Homburg, Germany
| | - Laura Schröder
- Center for Molecular Signaling (PZMS), Institute for Molecular Cell Biology; Medical Faculty, Saarland University, Homburg, Germany
| | - Sandra Ruppenthal
- Center for Molecular Signaling (PZMS), Institute for Molecular Cell Biology; Medical Faculty, Saarland University, Homburg, Germany
| | - Lars Kaestner
- Center for Molecular Signaling (PZMS), Institute for Molecular Cell Biology; Medical Faculty, Saarland University, Homburg, Germany
| | - Ulrich Boehm
- Center for Molecular Signaling (PZMS), Institute for Experimental and Clinical Pharmacology and Toxicology, Medical Faculty, Saarland University, Homburg, Germany
| | - Philipp Wartenberg
- Center for Molecular Signaling (PZMS), Institute for Experimental and Clinical Pharmacology and Toxicology, Medical Faculty, Saarland University, Homburg, Germany
| | - Huiyan Lu
- Mouse Transgenic Core Facility, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD, USA
| | - Sara M McMillin
- Molecular Signaling Section, Lab. of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD, USA
| | - Derek B J Bone
- Molecular Signaling Section, Lab. of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD, USA
| | - Jürgen Wess
- Molecular Signaling Section, Lab. of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD, USA
| | - Peter Lipp
- Center for Molecular Signaling (PZMS), Institute for Molecular Cell Biology; Medical Faculty, Saarland University, Homburg, Germany
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