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Kamkin AG, Kamkina OV, Kazansky VE, Mitrokhin VM, Bilichenko A, Nasedkina EA, Shileiko SA, Rodina AS, Zolotareva AD, Zolotarev VI, Sutyagin PV, Mladenov MI. Identification of RNA reads encoding different channels in isolated rat ventricular myocytes and the effect of cell stretching on L-type Ca 2+current. Biol Direct 2023; 18:70. [PMID: 37899484 PMCID: PMC10614344 DOI: 10.1186/s13062-023-00427-0] [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: 06/19/2023] [Accepted: 10/13/2023] [Indexed: 10/31/2023] Open
Abstract
BACKGROUND The study aimed to identify transcripts of specific ion channels in rat ventricular cardiomyocytes and determine their potential role in the regulation of ionic currents in response to mechanical stimulation. The gene expression levels of various ion channels in freshly isolated rat ventricular cardiomyocytes were investigated using the RNA-seq technique. We also measured changes in current through CaV1.2 channels under cell stretching using the whole-cell patch-clamp method. RESULTS Among channels that showed mechanosensitivity, significant amounts of TRPM7, TRPC1, and TRPM4 transcripts were found. We suppose that the recorded L-type Ca2+ current is probably expressed through CaV1.2. Furthermore, stretching cells by 6, 8, and 10 μm, which increases ISAC through the TRPM7, TRPC1, and TRPM4 channels, also decreased ICa,L through the CaV1.2 channels in K+ in/K+ out, Cs+ in/K+ out, K+ in/Cs+ out, and Cs+ in/Cs+ out solutions. The application of a nonspecific ISAC blocker, Gd3+, during cell stretching eliminated ISAC through nonselective cation channels and ICa,L through CaV1.2 channels. Since the response to Gd3+ was maintained in Cs+ in/Cs+ out solutions, we suggest that voltage-gated CaV1.2 channels in the ventricular myocytes of adult rats also exhibit mechanosensitive properties. CONCLUSIONS Our findings suggest that TRPM7, TRPC1, and TRPM4 channels represent stretch-activated nonselective cation channels in rat ventricular myocytes. Probably the CaV1.2 channels in these cells exhibit mechanosensitive properties. Our results provide insight into the molecular mechanisms underlying stretch-induced responses in rat ventricular myocytes, which may have implications for understanding cardiac physiology and pathophysiology.
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Affiliation(s)
- Andre G Kamkin
- Department of Physiology, Pirogov Russian National Research Medical University, Moscow, Russian Federation
| | - Olga V Kamkina
- Department of Physiology, Pirogov Russian National Research Medical University, Moscow, Russian Federation
| | - Viktor E Kazansky
- Department of Physiology, Pirogov Russian National Research Medical University, Moscow, Russian Federation
| | - Vadim M Mitrokhin
- Department of Physiology, Pirogov Russian National Research Medical University, Moscow, Russian Federation
| | - Andrey Bilichenko
- Department of Physiology, Pirogov Russian National Research Medical University, Moscow, Russian Federation
| | - Elizaveta A Nasedkina
- Department of Physiology, Pirogov Russian National Research Medical University, Moscow, Russian Federation
| | - Stanislav A Shileiko
- Department of Physiology, Pirogov Russian National Research Medical University, Moscow, Russian Federation
| | - Anastasia S Rodina
- Department of Physiology, Pirogov Russian National Research Medical University, Moscow, Russian Federation
| | - Alexandra D Zolotareva
- Department of Physiology, Pirogov Russian National Research Medical University, Moscow, Russian Federation
| | - Valentin I Zolotarev
- Department of Physiology, Pirogov Russian National Research Medical University, Moscow, Russian Federation
| | - Pavel V Sutyagin
- Department of Physiology, Pirogov Russian National Research Medical University, Moscow, Russian Federation
| | - Mitko I Mladenov
- Department of Physiology, Pirogov Russian National Research Medical University, Moscow, Russian Federation.
- Faculty of Natural Sciences and Mathematics, Institute of Biology, "Ss. Cyril and Methodius" University, Skopje, North, Macedonia.
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Xing C, Bao L, Li W, Fan H. Progress on role of ion channels of cardiac fibroblasts in fibrosis. Front Physiol 2023; 14:1138306. [PMID: 36969589 PMCID: PMC10033868 DOI: 10.3389/fphys.2023.1138306] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2023] [Accepted: 02/27/2023] [Indexed: 03/29/2023] Open
Abstract
Cardiac fibrosis is defined as excessive deposition of extracellular matrix (ECM) in pathological conditions. Cardiac fibroblasts (CFs) activated by injury or inflammation differentiate into myofibroblasts (MFs) with secretory and contractile functions. In the fibrotic heart, MFs produce ECM which is composed mainly of collagen and is initially involved in maintaining tissue integrity. However, persistent fibrosis disrupts the coordination of excitatory contractile coupling, leading to systolic and diastolic dysfunction, and ultimately heart failure. Numerous studies have demonstrated that both voltage- and non-voltage-gated ion channels alter intracellular ion levels and cellular activity, contributing to myofibroblast proliferation, contraction, and secretory function. However, an effective treatment strategy for myocardial fibrosis has not been established. Therefore, this review describes the progress made in research related to transient receptor potential (TRP) channels, Piezo1, Ca2+ release-activated Ca2+ (CRAC) channels, voltage-gated Ca2+ channels (VGCCs), sodium channels, and potassium channels in myocardial fibroblasts with the aim of providing new ideas for treating myocardial fibrosis.
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Fancher IS. Cardiovascular mechanosensitive ion channels-Translating physical forces into physiological responses. CURRENT TOPICS IN MEMBRANES 2021; 87:47-95. [PMID: 34696889 DOI: 10.1016/bs.ctm.2021.07.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Cells and tissues are constantly exposed to mechanical stress. In order to respond to alterations in mechanical stimuli, specific cellular machinery must be in place to rapidly convert physical force into chemical signaling to achieve the desired physiological responses. Mechanosensitive ion channels respond to such physical stimuli in the order of microseconds and are therefore essential components to mechanotransduction. Our understanding of how these ion channels contribute to cellular and physiological responses to mechanical force has vastly expanded in the last few decades due to engineering ingenuities accompanying patch clamp electrophysiology, as well as sophisticated molecular and genetic approaches. Such investigations have unveiled major implications for mechanosensitive ion channels in cardiovascular health and disease. Therefore, in this chapter I focus on our present understanding of how biophysical activation of various mechanosensitive ion channels promotes distinct cell signaling events with tissue-specific physiological responses in the cardiovascular system. Specifically, I discuss the roles of mechanosensitive ion channels in mediating (i) endothelial and smooth muscle cell control of vascular tone, (ii) mechano-electric feedback and cell signaling pathways in cardiomyocytes and cardiac fibroblasts, and (iii) the baroreflex.
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Affiliation(s)
- Ibra S Fancher
- Department of Kinesiology and Applied Physiology, College of Health Sciences, University of Delaware, Newark, DE, United States.
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Barbeau S, Gilbert G, Cardouat G, Baudrimont I, Freund-Michel V, Guibert C, Marthan R, Vacher P, Quignard JF, Ducret T. Mechanosensitivity in Pulmonary Circulation: Pathophysiological Relevance of Stretch-Activated Channels in Pulmonary Hypertension. Biomolecules 2021; 11:biom11091389. [PMID: 34572602 PMCID: PMC8470538 DOI: 10.3390/biom11091389] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Revised: 09/17/2021] [Accepted: 09/19/2021] [Indexed: 01/03/2023] Open
Abstract
A variety of cell types in pulmonary arteries (endothelial cells, fibroblasts, and smooth muscle cells) are continuously exposed to mechanical stimulations such as shear stress and pulsatile blood pressure, which are altered under conditions of pulmonary hypertension (PH). Most functions of such vascular cells (e.g., contraction, migration, proliferation, production of extracellular matrix proteins, etc.) depend on a key event, i.e., the increase in intracellular calcium concentration ([Ca2+]i) which results from an influx of extracellular Ca2+ and/or a release of intracellular stored Ca2+. Calcium entry from the extracellular space is a major step in the elevation of [Ca2+]i, involving a variety of plasmalemmal Ca2+ channels including the superfamily of stretch-activated channels (SAC). A common characteristic of SAC is that their gating depends on membrane stretch. In general, SAC are non-selective Ca2+-permeable cation channels, including proteins of the TRP (Transient Receptor Potential) and Piezo channel superfamily. As membrane mechano-transducers, SAC convert physical forces into biological signals and hence into a cell response. Consequently, SAC play a major role in pulmonary arterial calcium homeostasis and, thus, appear as potential novel drug targets for a better management of PH.
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Affiliation(s)
- Solène Barbeau
- Centre de Recherche Cardio-Thoracique de Bordeaux, Univ. Bordeaux, U1045, F-33600 Pessac, France; (S.B.); (G.C.); (I.B.); (V.F.-M.); (C.G.); (R.M.); (P.V.); (J.-F.Q.)
- INSERM, Centre de Recherche Cardio-Thoracique de Bordeaux, U1045, F-33600 Pessac, France
| | - Guillaume Gilbert
- ORPHY, UFR Sciences et Techniques, University of Brest, EA 4324, F-29238 Brest, France;
| | - Guillaume Cardouat
- Centre de Recherche Cardio-Thoracique de Bordeaux, Univ. Bordeaux, U1045, F-33600 Pessac, France; (S.B.); (G.C.); (I.B.); (V.F.-M.); (C.G.); (R.M.); (P.V.); (J.-F.Q.)
- INSERM, Centre de Recherche Cardio-Thoracique de Bordeaux, U1045, F-33600 Pessac, France
| | - Isabelle Baudrimont
- Centre de Recherche Cardio-Thoracique de Bordeaux, Univ. Bordeaux, U1045, F-33600 Pessac, France; (S.B.); (G.C.); (I.B.); (V.F.-M.); (C.G.); (R.M.); (P.V.); (J.-F.Q.)
- INSERM, Centre de Recherche Cardio-Thoracique de Bordeaux, U1045, F-33600 Pessac, France
| | - Véronique Freund-Michel
- Centre de Recherche Cardio-Thoracique de Bordeaux, Univ. Bordeaux, U1045, F-33600 Pessac, France; (S.B.); (G.C.); (I.B.); (V.F.-M.); (C.G.); (R.M.); (P.V.); (J.-F.Q.)
- INSERM, Centre de Recherche Cardio-Thoracique de Bordeaux, U1045, F-33600 Pessac, France
| | - Christelle Guibert
- Centre de Recherche Cardio-Thoracique de Bordeaux, Univ. Bordeaux, U1045, F-33600 Pessac, France; (S.B.); (G.C.); (I.B.); (V.F.-M.); (C.G.); (R.M.); (P.V.); (J.-F.Q.)
- INSERM, Centre de Recherche Cardio-Thoracique de Bordeaux, U1045, F-33600 Pessac, France
| | - Roger Marthan
- Centre de Recherche Cardio-Thoracique de Bordeaux, Univ. Bordeaux, U1045, F-33600 Pessac, France; (S.B.); (G.C.); (I.B.); (V.F.-M.); (C.G.); (R.M.); (P.V.); (J.-F.Q.)
- INSERM, Centre de Recherche Cardio-Thoracique de Bordeaux, U1045, F-33600 Pessac, France
| | - Pierre Vacher
- Centre de Recherche Cardio-Thoracique de Bordeaux, Univ. Bordeaux, U1045, F-33600 Pessac, France; (S.B.); (G.C.); (I.B.); (V.F.-M.); (C.G.); (R.M.); (P.V.); (J.-F.Q.)
- INSERM, Centre de Recherche Cardio-Thoracique de Bordeaux, U1045, F-33600 Pessac, France
| | - Jean-François Quignard
- Centre de Recherche Cardio-Thoracique de Bordeaux, Univ. Bordeaux, U1045, F-33600 Pessac, France; (S.B.); (G.C.); (I.B.); (V.F.-M.); (C.G.); (R.M.); (P.V.); (J.-F.Q.)
- INSERM, Centre de Recherche Cardio-Thoracique de Bordeaux, U1045, F-33600 Pessac, France
| | - Thomas Ducret
- Centre de Recherche Cardio-Thoracique de Bordeaux, Univ. Bordeaux, U1045, F-33600 Pessac, France; (S.B.); (G.C.); (I.B.); (V.F.-M.); (C.G.); (R.M.); (P.V.); (J.-F.Q.)
- INSERM, Centre de Recherche Cardio-Thoracique de Bordeaux, U1045, F-33600 Pessac, France
- Correspondence:
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Stewart L, Turner NA. Channelling the Force to Reprogram the Matrix: Mechanosensitive Ion Channels in Cardiac Fibroblasts. Cells 2021; 10:990. [PMID: 33922466 PMCID: PMC8145896 DOI: 10.3390/cells10050990] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Revised: 04/13/2021] [Accepted: 04/21/2021] [Indexed: 02/06/2023] Open
Abstract
Cardiac fibroblasts (CF) play a pivotal role in preserving myocardial function and integrity of the heart tissue after injury, but also contribute to future susceptibility to heart failure. CF sense changes to the cardiac environment through chemical and mechanical cues that trigger changes in cellular function. In recent years, mechanosensitive ion channels have been implicated as key modulators of a range of CF functions that are important to fibrotic cardiac remodelling, including cell proliferation, myofibroblast differentiation, extracellular matrix turnover and paracrine signalling. To date, seven mechanosensitive ion channels are known to be functional in CF: the cation non-selective channels TRPC6, TRPM7, TRPV1, TRPV4 and Piezo1, and the potassium-selective channels TREK-1 and KATP. This review will outline current knowledge of these mechanosensitive ion channels in CF, discuss evidence of the mechanosensitivity of each channel, and detail the role that each channel plays in cardiac remodelling. By better understanding the role of mechanosensitive ion channels in CF, it is hoped that therapies may be developed for reducing pathological cardiac remodelling.
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Affiliation(s)
| | - Neil A. Turner
- Discovery and Translational Science Department, Leeds Institute of Cardiovascular and Metabolic Medicine, School of Medicine, University of Leeds, Leeds LS2 9JT, UK;
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Izu LT, Kohl P, Boyden PA, Miura M, Banyasz T, Chiamvimonvat N, Trayanova N, Bers DM, Chen-Izu Y. Mechano-electric and mechano-chemo-transduction in cardiomyocytes. J Physiol 2020; 598:1285-1305. [PMID: 31789427 PMCID: PMC7127983 DOI: 10.1113/jp276494] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2019] [Accepted: 11/21/2019] [Indexed: 12/11/2022] Open
Abstract
Cardiac excitation-contraction (E-C) coupling is influenced by (at least) three dynamic systems that couple and feedback to one another (see Abstract Figure). Here we review the mechanical effects on cardiomyocytes that include mechano-electro-transduction (commonly referred to as mechano-electric coupling, MEC) and mechano-chemo-transduction (MCT) mechanisms at cell and molecular levels which couple to Ca2+ -electro and E-C coupling reviewed elsewhere. These feedback loops from muscle contraction and mechano-transduction to the Ca2+ homeodynamics and to the electrical excitation are essential for understanding the E-C coupling dynamic system and arrhythmogenesis in mechanically loaded hearts. This white paper comprises two parts, each reflecting key aspects from the 2018 UC Davis symposium: MEC (how mechanical load influences electrical dynamics) and MCT (how mechanical load alters cell signalling and Ca2+ dynamics). Of course, such separation is artificial since Ca2+ dynamics profoundly affect ion channels and electrogenic transporters and vice versa. In time, these dynamic systems and their interactions must become fully integrated, and that should be a goal for a comprehensive understanding of how mechanical load influences cell signalling, Ca2+ homeodynamics and electrical dynamics. In this white paper we emphasize current understanding, consensus, controversies and the pressing issues for future investigations. Space constraints make it impossible to cover all relevant articles in the field, so we will focus on the topics discussed at the symposium.
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Affiliation(s)
- Leighton T. Izu
- Department of Pharmacology, University of California, Davis, CA 95616, USA
| | - Peter Kohl
- Institute for Experimental Cardiovascular Medicine, University Heart Centre, and Faculty of Medicine, University of Freiburg, D-79110, Germany
| | | | - Masahito Miura
- Department of Clinical Physiology, Health Science, Tohoku University Graduate School of Medicine, Sendai 980-8574, Japan
| | - Tamas Banyasz
- Department of Physiology, University of Debrecen, Debrecen, Hungary
| | - Nipavan Chiamvimonvat
- Department of Internal Medicine, Cardiovascular Medicine, University of California, Davis, USA
| | - Natalia Trayanova
- Department of Department of Medicine, Johns Hopkins University, Baltimore, MD 21205, USA
| | - Donald M. Bers
- Department of Pharmacology, University of California, Davis, CA 95616, USA
| | - Ye Chen-Izu
- Department of Pharmacology, University of California, Davis, CA 95616, USA
- Department of Internal Medicine, Cardiovascular Medicine, University of California, Davis, USA
- Department of Biomedical Engineering, University of California, Davis, CA 95616, USA
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7
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Tinker A, Aziz Q, Li Y, Specterman M. ATP‐Sensitive Potassium Channels and Their Physiological and Pathophysiological Roles. Compr Physiol 2018; 8:1463-1511. [DOI: 10.1002/cphy.c170048] [Citation(s) in RCA: 72] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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8
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Levy AD, Xiao X, Shaw JE, Sudarsana Devi SP, Katrancha SM, Bennett AM, Greer CA, Howe JR, Machida K, Koleske AJ. Noonan Syndrome-Associated SHP2 Dephosphorylates GluN2B to Regulate NMDA Receptor Function. Cell Rep 2018; 24:1523-1535. [PMID: 30089263 PMCID: PMC6234505 DOI: 10.1016/j.celrep.2018.07.006] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2018] [Revised: 05/21/2018] [Accepted: 07/01/2018] [Indexed: 11/23/2022] Open
Abstract
Hyperactivating mutations in the non-receptor tyrosine phosphatase SHP2 cause Noonan syndrome (NS). NS is associated with cognitive deficits, but how hyperactivation of SHP2 in NS changes neuron function is not well understood. We find that mice bearing an NS-associated SHP2 allele (NS mice) have selectively impaired Schaffer collateral-CA1 NMDA (N-methyl-D-aspartate) receptor (NMDAR)-mediated neurotransmission and that residual NMDAR-mediated currents decay faster in NS mice because of reduced contribution of GluN1:GluN2B diheteromers. Consistent with altered GluN2B function, we identify GluN2B Y1252 as an NS-associated SHP2 substrate both in vitro and in vivo. Mutation of Y1252 does not alter recombinant GluN1:GluN2B receptor kinetics. Instead, phospho-Y1252 binds the actin-regulatory adaptor protein Nck2, and this interaction is required for proper NMDAR function. These results establish SHP2 and Nck2 as NMDAR regulatory proteins and strongly suggest that NMDAR dysfunction contributes to NS cognitive deficits.
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Affiliation(s)
- Aaron D Levy
- Interdepartmental Neuroscience Program, Yale University, New Haven, CT 06520, USA
| | - Xiao Xiao
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06520, USA
| | - Juliana E Shaw
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06520, USA
| | | | - Sara Marie Katrancha
- Interdepartmental Neuroscience Program, Yale University, New Haven, CT 06520, USA
| | - Anton M Bennett
- Department of Pharmacology, Yale University, New Haven, CT 06520, USA; Program in Integrative Cell Signaling and Neurobiology of Metabolism, Yale University, New Haven, CT 06520, USA
| | - Charles A Greer
- Interdepartmental Neuroscience Program, Yale University, New Haven, CT 06520, USA; Department of Neurosurgery, Yale University, New Haven, CT 06520, USA; Department of Neuroscience, Yale University, New Haven, CT 06520, USA
| | - James R Howe
- Interdepartmental Neuroscience Program, Yale University, New Haven, CT 06520, USA; Department of Pharmacology, Yale University, New Haven, CT 06520, USA
| | - Kazuya Machida
- Raymond and Beverly Sackler Laboratory of Genetics and Molecular Medicine, Department of Genetics and Genome Sciences, University of Connecticut School of Medicine, Farmington, CT 06030, USA
| | - Anthony J Koleske
- Interdepartmental Neuroscience Program, Yale University, New Haven, CT 06520, USA; Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06520, USA; Department of Neuroscience, Yale University, New Haven, CT 06520, USA; Program in Cellular Neuroscience, Neurodegeneration and Repair, Yale University, New Haven, CT 06520, USA.
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Katsi V, Georgiopoulos G, Marketou M, Oikonomou D, Parthenakis F, Makris T, Nihoyannopoulos P, Vardas P, Tousoulis D. Atrial fibrillation in pregnancy: a growing challenge. Curr Med Res Opin 2017; 33:1497-1504. [PMID: 28498066 DOI: 10.1080/03007995.2017.1330257] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
BACKGROUND Atrial fibrillation (AF) constitutes a relatively infrequent pregnancy complication, which may be a therapeutic Gordian knot. Indeed, sparse data exist regarding the prevalence, prognosis, and management of AF during pregnancy. In general, AF occurs as a benign, self-limited arrhythmia, but occasionally may have severe hemodynamic consequences in pregnant patients suffering from heart failure, congenital heart disease, or other comorbidities. Extra-cardiac causes of AF should always be meticulously excluded. REVIEW Treatment decisions are difficult, since medications may cross the placental barrier and potentially affect fetal growth and organogenesis, or even result in fetal bradyarrhythmias. Treatment goals are not differentiated in comparison to those regarding AF occurring in the general population. Still, while maternal treatment is prioritized, issues regarding fetal health must deliberately be considered. Consequently, hemodynamic instability is to be promptly treated with synchronized electrical cardioversion. In contrast, in stable patients, pharmacologic cardioversion, under appropriate antithrombotic regimen, should be attempted. Selection of appropriate antithrombotic therapy, including novel oral anticoagulants, imposes further difficulties on therapeutic decision-making. Further clinical trials are warranted in order to assess the pathophysiology and prognosis of AF in pregnancy and ameliorate the evidence-based therapeutic strategy in this specific group of the population.
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Affiliation(s)
- Vasiliki Katsi
- a First Department of Cardiology , Hippokration Hospital, University of Athens , Athens , Greece
| | - Georgios Georgiopoulos
- a First Department of Cardiology , Hippokration Hospital, University of Athens , Athens , Greece
| | - Maria Marketou
- b Cardiology Department , Heraklion University Hospital , Crete , Greece
| | - Dimitrios Oikonomou
- a First Department of Cardiology , Hippokration Hospital, University of Athens , Athens , Greece
| | | | - Thomas Makris
- c Cardiology Department , Helena Venizelou Hospital , Athens , Greece
| | - Petros Nihoyannopoulos
- a First Department of Cardiology , Hippokration Hospital, University of Athens , Athens , Greece
| | - P Vardas
- b Cardiology Department , Heraklion University Hospital , Crete , Greece
| | - Dimitris Tousoulis
- a First Department of Cardiology , Hippokration Hospital, University of Athens , Athens , Greece
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Decher N, Kiper AK, Rinné S. Stretch-activated potassium currents in the heart: Focus on TREK-1 and arrhythmias. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2017; 130:223-232. [PMID: 28526352 DOI: 10.1016/j.pbiomolbio.2017.05.005] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2017] [Revised: 05/09/2017] [Accepted: 05/15/2017] [Indexed: 12/26/2022]
Abstract
This review focuses on the role and the molecular candidates of the cardiac stretch-activated potassium current (SAK). The functional properties of the two-pore domain potassium (K2P) channel TREK-1, a major candidate for the cardiac SAK, are analyzed and the molecular mechanism of stretch-activation in K2P potassium channels is discussed. Furthermore, the functional modulation of TREK-1 by different cardiac interaction partners, as well as evidence for the functional role of the stretch-dependent TREK-1 and its putative subunits in the heart is reviewed. In addition, we summarize the recent evidence that TREK-1 is involved in the pathogenesis of human cardiac arrhythmias.
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Affiliation(s)
- Niels Decher
- Institute for Physiology and Pathophysiology, AG Vegetative Physiology, Deutschhausstrasse 1-2, 35037 Marburg, Germany.
| | - Aytug K Kiper
- Institute for Physiology and Pathophysiology, AG Vegetative Physiology, Deutschhausstrasse 1-2, 35037 Marburg, Germany
| | - Susanne Rinné
- Institute for Physiology and Pathophysiology, AG Vegetative Physiology, Deutschhausstrasse 1-2, 35037 Marburg, Germany
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11
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Hormones and sex differences: changes in cardiac electrophysiology with pregnancy. Clin Sci (Lond) 2017; 130:747-59. [PMID: 27128800 DOI: 10.1042/cs20150710] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2015] [Accepted: 02/01/2016] [Indexed: 11/17/2022]
Abstract
Disruption of cardiac electrical activity resulting in palpitations and syncope is often an early symptom of pregnancy. Pregnancy is a time of dramatic and dynamic physiological and hormonal changes during which numerous demands are placed on the heart. These changes result in electrical remodelling which can be detected as changes in the electrocardiogram (ECG). This gestational remodelling is a very under-researched area. There are no systematic large studies powered to determine changes in the ECG from pre-pregnancy, through gestation, and into the postpartum period. The large variability between patients and the dynamic nature of pregnancy hampers interpretation of smaller studies, but some facts are consistent. Gestational cardiac hypertrophy and a physical shift of the heart contribute to changes in the ECG. There are also electrical changes such as an increased heart rate and lengthening of the QT interval. There is an increased susceptibility to arrhythmias during pregnancy and the postpartum period. Some changes in the ECG are clearly the result of changes in ion channel expression and behaviour, but little is known about the ionic basis for this electrical remodelling. Most information comes from animal models, and implicates changes in the delayed-rectifier channels. However, it is likely that there are additional roles for sodium channels as well as changes in calcium homoeostasis. The changes in the electrical profile of the heart during pregnancy and the postpartum period have clear implications for the safety of pregnant women, but the field remains relatively undeveloped.
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12
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Schwingshackl A. The role of stretch-activated ion channels in acute respiratory distress syndrome: finally a new target? Am J Physiol Lung Cell Mol Physiol 2016; 311:L639-52. [PMID: 27521425 DOI: 10.1152/ajplung.00458.2015] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2016] [Accepted: 08/05/2016] [Indexed: 02/06/2023] Open
Abstract
Mechanical ventilation (MV) and oxygen therapy (hyperoxia; HO) comprise the cornerstones of life-saving interventions for patients with acute respiratory distress syndrome (ARDS). Unfortunately, the side effects of MV and HO include exacerbation of lung injury by barotrauma, volutrauma, and propagation of lung inflammation. Despite significant improvements in ventilator technologies and a heightened awareness of oxygen toxicity, besides low tidal volume ventilation few if any medical interventions have improved ARDS outcomes over the past two decades. We are lacking a comprehensive understanding of mechanotransduction processes in the healthy lung and know little about the interactions between simultaneously activated stretch-, HO-, and cytokine-induced signaling cascades in ARDS. Nevertheless, as we are unraveling these mechanisms we are gathering increasing evidence for the importance of stretch-activated ion channels (SACs) in the activation of lung-resident and inflammatory cells. In addition to the discovery of new SAC families in the lung, e.g., two-pore domain potassium channels, we are increasingly assigning mechanosensing properties to already known Na(+), Ca(2+), K(+), and Cl(-) channels. Better insights into the mechanotransduction mechanisms of SACs will improve our understanding of the pathways leading to ventilator-induced lung injury and lead to much needed novel therapeutic approaches against ARDS by specifically targeting SACs. This review 1) summarizes the reasons why the time has come to seriously consider SACs as new therapeutic targets against ARDS, 2) critically analyzes the physiological and experimental factors that currently limit our knowledge about SACs, and 3) outlines the most important questions future research studies need to address.
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Abstract
Mechanical forces will have been omnipresent since the origin of life, and living organisms have evolved mechanisms to sense, interpret, and respond to mechanical stimuli. The cardiovascular system in general, and the heart in particular, is exposed to constantly changing mechanical signals, including stretch, compression, bending, and shear. The heart adjusts its performance to the mechanical environment, modifying electrical, mechanical, metabolic, and structural properties over a range of time scales. Many of the underlying regulatory processes are encoded intracardially and are, thus, maintained even in heart transplant recipients. Although mechanosensitivity of heart rhythm has been described in the medical literature for over a century, its molecular mechanisms are incompletely understood. Thanks to modern biophysical and molecular technologies, the roles of mechanical forces in cardiac biology are being explored in more detail, and detailed mechanisms of mechanotransduction have started to emerge. Mechano-gated ion channels are cardiac mechanoreceptors. They give rise to mechano-electric feedback, thought to contribute to normal function, disease development, and, potentially, therapeutic interventions. In this review, we focus on acute mechanical effects on cardiac electrophysiology, explore molecular candidates underlying observed responses, and discuss their pharmaceutical regulation. From this, we identify open research questions and highlight emerging technologies that may help in addressing them.
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Affiliation(s)
- Rémi Peyronnet
- From the National Heart and Lung Institute, Imperial College London, United Kingdom (R.P., P.K.); Departments of Developmental Biology and Internal Medicine, Center for Cardiovascular Research, Washington University School of Medicine, St. Louis, MO (J.M.N.); Institute for Experimental Cardiovascular Medicine, University Heart Centre Freiburg/Bad Krozingen, Freiburg, Germany (R.P., P.K.)
| | - Jeanne M Nerbonne
- From the National Heart and Lung Institute, Imperial College London, United Kingdom (R.P., P.K.); Departments of Developmental Biology and Internal Medicine, Center for Cardiovascular Research, Washington University School of Medicine, St. Louis, MO (J.M.N.); Institute for Experimental Cardiovascular Medicine, University Heart Centre Freiburg/Bad Krozingen, Freiburg, Germany (R.P., P.K.)
| | - Peter Kohl
- From the National Heart and Lung Institute, Imperial College London, United Kingdom (R.P., P.K.); Departments of Developmental Biology and Internal Medicine, Center for Cardiovascular Research, Washington University School of Medicine, St. Louis, MO (J.M.N.); Institute for Experimental Cardiovascular Medicine, University Heart Centre Freiburg/Bad Krozingen, Freiburg, Germany (R.P., P.K.).
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Roy Chowdhury U, Bahler CK, Holman BH, Dosa PI, Fautsch MP. Ocular Hypotensive Effects of the ATP-Sensitive Potassium Channel Opener Cromakalim in Human and Murine Experimental Model Systems. PLoS One 2015; 10:e0141783. [PMID: 26535899 PMCID: PMC4633217 DOI: 10.1371/journal.pone.0141783] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2015] [Accepted: 10/13/2015] [Indexed: 11/17/2022] Open
Abstract
Elevated intraocular pressure (IOP) is the most prevalent and only treatable risk factor for glaucoma, a leading cause of irreversible blindness worldwide. Unfortunately, all current therapeutics used to treat elevated IOP and glaucoma have significant and sometimes irreversible side effects necessitating the development of novel compounds. We evaluated the IOP lowering ability of the broad spectrum KATP channel opener cromakalim. Cultured human anterior segments when treated with 2 μM cromakalim showed a decrease in pressure (19.33 ± 2.78 mmHg at 0 hours to 13.22 ± 2.64 mmHg at 24 hours; p<0.001) when compared to vehicle treated controls (15.89 ± 5.33 mmHg at 0 h to 15.56 ± 4.88 mmHg at 24 hours; p = 0.89). In wild-type C57BL/6 mice, cromakalim reduced IOP by 18.75 ± 2.22% compared to vehicle treated contralateral eyes (17.01 ± 0.32 mmHg at 0 hours to 13.82 ± 0.37 mmHg at 24 hours; n = 10, p = 0.002). Cromakalim demonstrated an additive effect when used in conjunction with latanoprost free acid, a common ocular hypotensive drug prescribed to patients with elevated IOP. To examine KATP channel subunit specificity, Kir6.2(-/-) mice were treated with cromakalim, but unlike wild-type animals, no change in IOP was noted. Histologic analysis of treated and control eyes in cultured human anterior segments and in mice showed similar cell numbers and extracellular matrix integrity within the trabecular meshwork, with no disruptions in the inner and outer walls of Schlemm's canal. Together, these studies suggest that cromakalim is a potent ocular hypotensive agent that lowers IOP via activation of Kir6.2 containing KATP channels, its effect is additive when used in combination with the commonly used glaucoma drug latanoprost, and is not toxic to cells and tissues of the aqueous humor outflow pathway, making it a candidate for future therapeutic development.
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Affiliation(s)
- Uttio Roy Chowdhury
- Department of Ophthalmology, Mayo Clinic, Rochester, MN, United States of America
| | - Cindy K Bahler
- Department of Ophthalmology, Mayo Clinic, Rochester, MN, United States of America
| | - Bradley H Holman
- Department of Ophthalmology, Mayo Clinic, Rochester, MN, United States of America
| | - Peter I Dosa
- Institute for Therapeutics Discovery and Development, University of Minnesota, Minneapolis, MN, United States of America
| | - Michael P Fautsch
- Department of Ophthalmology, Mayo Clinic, Rochester, MN, United States of America
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Reed A, Kohl P, Peyronnet R. Molecular candidates for cardiac stretch-activated ion channels. Glob Cardiol Sci Pract 2014; 2014:9-25. [PMID: 25405172 PMCID: PMC4220428 DOI: 10.5339/gcsp.2014.19] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2014] [Accepted: 06/08/2014] [Indexed: 01/20/2023] Open
Abstract
The heart is a mechanically-active organ that dynamically senses its own mechanical environment. This environment is constantly changing, on a beat-by-beat basis, with additional modulation by respiratory activity and changes in posture or physical activity, and further overlaid with more slowly occurring physiological (e.g. pregnancy, endurance training) or pathological challenges (e.g. pressure or volume overload). Far from being a simple pump, the heart detects changes in mechanical demand and adjusts its performance accordingly, both via heart rate and stroke volume alteration. Many of the underlying regulatory processes are encoded intracardially, and are thus maintained even in heart transplant recipients. Over the last three decades, molecular substrates of cardiac mechanosensitivity have gained increasing recognition in the scientific and clinical communities. Nonetheless, the processes underlying this phenomenon are still poorly understood. Stretch-activated ion channels (SAC) have been identified as one contributor to mechanosensitive autoregulation of the heartbeat. They also appear to play important roles in the development of cardiac pathologies – most notably stretch-induced arrhythmias. As recently discovered, some established cardiac drugs act, in part at least, via mechanotransduction pathways suggesting SAC as potential therapeutic targets. Clearly, identification of the molecular substrate of cardiac SAC is of clinical importance and a number of candidate proteins have been identified. At the same time, experimental studies have revealed variable–and at times contrasting–results regarding their function. Further complication arises from the fact that many ion channels that are not classically defined as SAC, including voltage and ligand-gated ion channels, can respond to mechanical stimulation. Here, we summarise what is known about the molecular substrate of the main candidates for cardiac SAC, before identifying potential further developments in this area of translational research.
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Affiliation(s)
- Alistair Reed
- Medical Sciences Division, University of Oxford, United Kingdom
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