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Camacho Londoño JE, Tian Q, Hammer K, Schröder L, Camacho Londoño J, Reil JC, He T, Oberhofer M, Mannebach S, Mathar I, Philipp SE, Tabellion W, Schweda F, Dietrich A, Kaestner L, Laufs U, Birnbaumer L, Flockerzi V, Freichel M, Lipp P. A background Ca2+ entry pathway mediated by TRPC1/TRPC4 is critical for development of pathological cardiac remodelling. Eur Heart J 2015; 36:2257-66. [PMID: 26069213 DOI: 10.1093/eurheartj/ehv250] [Citation(s) in RCA: 84] [Impact Index Per Article: 9.3] [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: 09/22/2014] [Accepted: 05/18/2015] [Indexed: 12/22/2022] Open
Abstract
AIMS Pathological cardiac hypertrophy is a major predictor for the development of cardiac diseases. It is associated with chronic neurohumoral stimulation and with altered cardiac Ca(2+) signalling in cardiomyocytes. TRPC proteins form agonist-induced cation channels, but their functional role for Ca(2+) homeostasis in cardiomyocytes during fast cytosolic Ca(2+) cycling and neurohumoral stimulation leading to hypertrophy is unknown. METHODS AND RESULTS In a systematic analysis of multiple knockout mice using fluorescence imaging of electrically paced adult ventricular cardiomyocytes and Mn(2+)-quench microfluorimetry, we identified a background Ca(2+) entry (BGCE) pathway that critically depends on TRPC1/C4 proteins but not others such as TRPC3/C6. Reduction of BGCE in TRPC1/C4-deficient cardiomyocytes lowers diastolic and systolic Ca(2+) concentrations both, under basal conditions and under neurohumoral stimulation without affecting cardiac contractility measured in isolated hearts and in vivo. Neurohumoral-induced cardiac hypertrophy as well as the expression of foetal genes (ANP, BNP) and genes regulated by Ca(2+)-dependent signalling (RCAN1-4, myomaxin) was reduced in TRPC1/C4 knockout (DKO), but not in TRPC1- or TRPC4-single knockout mice. Pressure overload-induced hypertrophy and interstitial fibrosis were both ameliorated in TRPC1/C4-DKO mice, whereas they did not show alterations in other cardiovascular parameters contributing to systemic neurohumoral-induced hypertrophy such as renin secretion and blood pressure. CONCLUSIONS The constitutively active TRPC1/C4-dependent BGCE fine-tunes Ca(2+) cycling in beating adult cardiomyocytes. TRPC1/C4-gene inactivation protects against development of maladaptive cardiac remodelling without altering cardiac or extracardiac functions contributing to this pathogenesis.
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Affiliation(s)
- Juan E Camacho Londoño
- Pharmakologisches Institut, Ruprecht-Karls-Universität Heidelberg, 69120 Heidelberg, Germany Experimentelle und Klinische Pharmakologie und Toxikologie, 66421 Homburg, Germany DZHK (German Centre for Cardiovascular Research), partner site Heidelberg/Mannheim, Germany
| | - Qinghai Tian
- Institut für Molekulare Zellbiologie, 66421 Homburg, Germany
| | - Karin Hammer
- Institut für Molekulare Zellbiologie, 66421 Homburg, Germany
| | - Laura Schröder
- Institut für Molekulare Zellbiologie, 66421 Homburg, Germany
| | | | - Jan C Reil
- Innere Medizin III Universität des Saarlandes, 66421 Homburg, Germany
| | - Tao He
- DZHK (German Centre for Cardiovascular Research), partner site Heidelberg/Mannheim, Germany Research Unit Cardiac Epigenetics, Department of Cardiology, Ruprecht-Karls-Universität Heidelberg, 69120 Heidelberg, Germany Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, 430030 Wuhan, China
| | | | - Stefanie Mannebach
- Experimentelle und Klinische Pharmakologie und Toxikologie, 66421 Homburg, Germany
| | - Ilka Mathar
- Pharmakologisches Institut, Ruprecht-Karls-Universität Heidelberg, 69120 Heidelberg, Germany Experimentelle und Klinische Pharmakologie und Toxikologie, 66421 Homburg, Germany
| | - Stephan E Philipp
- Experimentelle und Klinische Pharmakologie und Toxikologie, 66421 Homburg, Germany
| | | | - Frank Schweda
- Institut für Physiologie, Universität Regensburg, 93053 Regensburg, Germany
| | - Alexander Dietrich
- Walther-Straub-Institut für Pharmakologie und Toxikologie, LMU, 80336 München, Germany
| | - Lars Kaestner
- Institut für Molekulare Zellbiologie, 66421 Homburg, Germany
| | - Ulrich Laufs
- Innere Medizin III Universität des Saarlandes, 66421 Homburg, Germany
| | - Lutz Birnbaumer
- Transmembrane Signaling Group, NIEHS, PO Box 12233, NC 27709, USA
| | - Veit Flockerzi
- Experimentelle und Klinische Pharmakologie und Toxikologie, 66421 Homburg, Germany
| | - Marc Freichel
- Pharmakologisches Institut, Ruprecht-Karls-Universität Heidelberg, 69120 Heidelberg, Germany Experimentelle und Klinische Pharmakologie und Toxikologie, 66421 Homburg, Germany DZHK (German Centre for Cardiovascular Research), partner site Heidelberg/Mannheim, Germany
| | - Peter Lipp
- Institut für Molekulare Zellbiologie, 66421 Homburg, Germany
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