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Burnstock G, Pelleg A. Cardiac purinergic signalling in health and disease. Purinergic Signal 2015; 11:1-46. [PMID: 25527177 PMCID: PMC4336308 DOI: 10.1007/s11302-014-9436-1] [Citation(s) in RCA: 103] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2014] [Accepted: 11/25/2014] [Indexed: 01/09/2023] Open
Abstract
This review is a historical account about purinergic signalling in the heart, for readers to see how ideas and understanding have changed as new experimental results were published. Initially, the focus is on the nervous control of the heart by ATP as a cotransmitter in sympathetic, parasympathetic, and sensory nerves, as well as in intracardiac neurons. Control of the heart by centers in the brain and vagal cardiovascular reflexes involving purines are also discussed. The actions of adenine nucleotides and nucleosides on cardiomyocytes, atrioventricular and sinoatrial nodes, cardiac fibroblasts, and coronary blood vessels are described. Cardiac release and degradation of ATP are also described. Finally, the involvement of purinergic signalling and its therapeutic potential in cardiac pathophysiology is reviewed, including acute and chronic heart failure, ischemia, infarction, arrhythmias, cardiomyopathy, syncope, hypertrophy, coronary artery disease, angina, diabetic cardiomyopathy, as well as heart transplantation and coronary bypass grafts.
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Affiliation(s)
- Geoffrey Burnstock
- Autonomic Neuroscience Centre, University College Medical School, Rowland Hill Street, London, NW3 2PF, UK,
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Coyan FC, Abderemane-Ali F, Amarouch MY, Piron J, Mordel J, Nicolas CS, Steenman M, Mérot J, Marionneau C, Thomas A, Brasseur R, Baró I, Loussouarn G. A long QT mutation substitutes cholesterol for phosphatidylinositol-4,5-bisphosphate in KCNQ1 channel regulation. PLoS One 2014; 9:e93255. [PMID: 24681627 PMCID: PMC3969324 DOI: 10.1371/journal.pone.0093255] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2013] [Accepted: 03/03/2014] [Indexed: 01/08/2023] Open
Abstract
Introduction Phosphatidylinositol-4,5-bisphosphate (PIP2) is a cofactor necessary for the activity of KCNQ1 channels. Some Long QT mutations of KCNQ1, including R243H, R539W and R555C have been shown to decrease KCNQ1 interaction with PIP2. A previous study suggested that R539W is paradoxically less sensitive to intracellular magnesium inhibition than the WT channel, despite a decreased interaction with PIP2. In the present study, we confirm this peculiar behavior of R539W and suggest a molecular mechanism underlying it. Methods and Results COS-7 cells were transfected with WT or mutated KCNE1-KCNQ1 channel, and patch-clamp recordings were performed in giant-patch, permeabilized-patch or ruptured-patch configuration. Similar to other channels with a decreased PIP2 affinity, we observed that the R243H and R555C mutations lead to an accelerated current rundown when membrane PIP2 levels are decreasing. As opposed to R243H and R555C mutants, R539W is not more but rather less sensitive to PIP2 decrease than the WT channel. A molecular model of a fragment of the KCNQ1 C-terminus and the membrane bilayer suggested that a potential novel interaction of R539W with cholesterol stabilizes the channel opening and hence prevents rundown upon PIP2 depletion. We then carried out the same rundown experiments under cholesterol depletion and observed an accelerated R539W rundown that is consistent with this model. Conclusions We show for the first time that a mutation may shift the channel interaction with PIP2 to a preference for cholesterol. This de novo interaction wanes the sensitivity to PIP2 variations, showing that a mutated channel with a decreased affinity to PIP2 could paradoxically present a slowed current rundown compared to the WT channel. This suggests that caution is required when using measurements of current rundown as an indicator to compare WT and mutant channel PIP2 sensitivity.
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Affiliation(s)
- Fabien C. Coyan
- l'institut du thorax, Institut National de la Santé et de la Recherche Médicale, Nantes, France
- Unité Mixte de Recherche 6291, Centre National de la Recherche Scientifique, Nantes, France
- Unité de Formation et de Recherche de Médecine, Université de Nantes, Nantes, France
| | - Fayal Abderemane-Ali
- l'institut du thorax, Institut National de la Santé et de la Recherche Médicale, Nantes, France
- Unité Mixte de Recherche 6291, Centre National de la Recherche Scientifique, Nantes, France
- Unité de Formation et de Recherche de Médecine, Université de Nantes, Nantes, France
| | - Mohamed Yassine Amarouch
- l'institut du thorax, Institut National de la Santé et de la Recherche Médicale, Nantes, France
- Unité Mixte de Recherche 6291, Centre National de la Recherche Scientifique, Nantes, France
- Unité de Formation et de Recherche de Médecine, Université de Nantes, Nantes, France
| | - Julien Piron
- l'institut du thorax, Institut National de la Santé et de la Recherche Médicale, Nantes, France
- Unité Mixte de Recherche 6291, Centre National de la Recherche Scientifique, Nantes, France
- Unité de Formation et de Recherche de Médecine, Université de Nantes, Nantes, France
| | - Jérôme Mordel
- l'institut du thorax, Institut National de la Santé et de la Recherche Médicale, Nantes, France
- Unité Mixte de Recherche 6291, Centre National de la Recherche Scientifique, Nantes, France
- Unité de Formation et de Recherche de Médecine, Université de Nantes, Nantes, France
| | - Céline S. Nicolas
- l'institut du thorax, Institut National de la Santé et de la Recherche Médicale, Nantes, France
- Unité Mixte de Recherche 6291, Centre National de la Recherche Scientifique, Nantes, France
- Unité de Formation et de Recherche de Médecine, Université de Nantes, Nantes, France
| | - Marja Steenman
- l'institut du thorax, Institut National de la Santé et de la Recherche Médicale, Nantes, France
- Unité Mixte de Recherche 6291, Centre National de la Recherche Scientifique, Nantes, France
| | - Jean Mérot
- l'institut du thorax, Institut National de la Santé et de la Recherche Médicale, Nantes, France
- Unité Mixte de Recherche 6291, Centre National de la Recherche Scientifique, Nantes, France
- Unité de Formation et de Recherche de Médecine, Université de Nantes, Nantes, France
| | - Céline Marionneau
- l'institut du thorax, Institut National de la Santé et de la Recherche Médicale, Nantes, France
- Unité Mixte de Recherche 6291, Centre National de la Recherche Scientifique, Nantes, France
- Unité de Formation et de Recherche de Médecine, Université de Nantes, Nantes, France
| | - Annick Thomas
- Institut de Pharmacologie et de Biologie Structurale, Centre National de la Recherche Scientifique, Toulouse, France
| | - Robert Brasseur
- Centre de Biophysique Moléculaire Numérique, University of Liège, Gembloux, Belgium
| | - Isabelle Baró
- l'institut du thorax, Institut National de la Santé et de la Recherche Médicale, Nantes, France
- Unité Mixte de Recherche 6291, Centre National de la Recherche Scientifique, Nantes, France
- Unité de Formation et de Recherche de Médecine, Université de Nantes, Nantes, France
| | - Gildas Loussouarn
- l'institut du thorax, Institut National de la Santé et de la Recherche Médicale, Nantes, France
- Unité Mixte de Recherche 6291, Centre National de la Recherche Scientifique, Nantes, France
- Unité de Formation et de Recherche de Médecine, Université de Nantes, Nantes, France
- * E-mail:
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Regulatory mechanisms underlying the modulation of GIRK1/GIRK4 heteromeric channels by P2Y receptors. Pflugers Arch 2012; 463:625-33. [PMID: 22362083 DOI: 10.1007/s00424-012-1082-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2011] [Revised: 02/05/2012] [Accepted: 02/06/2012] [Indexed: 01/10/2023]
Abstract
The muscarinic K(+) channel (I (K,ACh)) is a heterotetramer composed of GIRK1 (Kir3.1) and GIRK4 (Kir3.4) subunits of a G protein-coupled inwardly rectifying channel, and plays an important role in mediating electrical responses to the vagal stimulation in the heart. I (K,ACh) displays biphasic changes (activation followed by inhibition) through the stimulation of the purinergic P2Y receptors, but the regulatory mechanism involved in these modulation of I (K,ACh) by P2Y receptors remains to be fully elucidated. Various P2Y receptor subtypes and GIRK1/GIRK4 (I (GIRK)) were co-expressed in Chinese hamster ovary cells, and the effect of stimulation of P2Y receptor subtypes on I (GIRK) were examined using the whole-cell patch-clamp method. Extracellular application of 10 μM ATP induced a transient activation of I (GIRK) through the P2Y(1) receptor, which was completely abolished by pretreatment with pertussis toxin. ATP initially caused an additive transient increase in ACh-activated I (GIRK) (via M(2) receptor), which was followed by subsequent inhibition. This inhibition of I (GIRK) by ATP was attenuated by co-expression of regulator of G-protein signaling 2, or phosphatidylinositol-4-phosphate-5-kinase, or intracellular phosphatidylinositol 4,5-bisphosphate loading, but not by the exposure to protein kinase C inhibitors. P2Y(4) stimulation also persistently suppressed the ACh-activated I (GIRK). In addition, I (GIRK) evoked by the stimulation of the P2Y(4) receptor exhibited a transient activation, but that evoked by the stimulation of P2Y(2) or P2Y(12) receptor showed a rather persistent activation. These results reveal (1) that P2Y(1) and P2Y(4) are primarily coupled to the G(q)-phospholipase C-pathway, while being weakly linked to G(i/o), and (2) that P2Y(2) and P2Y(12) involve G(i/o) activation.
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KCNE1 enhances phosphatidylinositol 4,5-bisphosphate (PIP2) sensitivity of IKs to modulate channel activity. Proc Natl Acad Sci U S A 2011; 108:9095-100. [PMID: 21576493 DOI: 10.1073/pnas.1100872108] [Citation(s) in RCA: 88] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Phosphatidylinositol 4,5-bisphosphate (PIP(2)) is necessary for the function of various ion channels. The potassium channel, I(Ks), is important for cardiac repolarization and requires PIP(2) to activate. Here we show that the auxiliary subunit of I(Ks), KCNE1, increases PIP(2) sensitivity 100-fold over channels formed by the pore-forming KCNQ1 subunits alone, which effectively amplifies current because native PIP(2) levels in the membrane are insufficient to activate all KCNQ1 channels. A juxtamembranous site in the KCNE1 C terminus is a key structural determinant of PIP(2) sensitivity. Long QT syndrome associated mutations of this site lower PIP(2) affinity, resulting in reduced current. Application of exogenous PIP(2) to these mutants restores wild-type channel activity. These results reveal a vital role of PIP(2) for KCNE1 modulation of I(Ks) channels that may represent a common mechanism of auxiliary subunit modulation of many ion channels.
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