1
|
Chakraborty P, Azam MA, Massé S, Lai PF, Rose RA, Ibarra Moreno CA, Riazi S, Nanthakumar K. Uncoupling cytosolic calcium from membrane voltage by transient receptor potential melastatin 4 channel (TRPM4) modulation: A novel strategy to treat ventricular arrhythmias. Heart Rhythm O2 2023; 4:725-732. [PMID: 38034891 PMCID: PMC10685170 DOI: 10.1016/j.hroo.2023.10.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2023] Open
Abstract
The current antiarrhythmic paradigm is mainly centered around modulating membrane voltage. However, abnormal cytosolic calcium (Ca2+) signaling, which plays an important role in driving membrane voltage, has not been targeted for therapeutic purposes in arrhythmogenesis. There is clear evidence for bidirectional coupling between membrane voltage and intracellular Ca2+. Cytosolic Ca2+ regulates membrane voltage through Ca2+-sensitive membrane currents. As a component of Ca2+-sensitive currents, Ca2+-activated nonspecific cationic current through the TRPM4 (transient receptor potential melastatin 4) channel plays a significant role in Ca2+-driven changes in membrane electrophysiology. In myopathic and ischemic ventricles, upregulation and/or enhanced activity of this current is associated with the generation of afterdepolarization (both early and delayed), reduction of repolarization reserve, and increased propensity to ventricular arrhythmias. In this review, we describe a novel concept for the management of ventricular arrhythmias in the remodeled ventricle based on mechanistic concepts from experimental studies, by uncoupling the Ca2+-induced changes in membrane voltage by inhibition of this TRPM4-mediated current.
Collapse
Affiliation(s)
- Praloy Chakraborty
- Hull Family Cardiac Fibrillation Management Laboratory, Toronto General Hospital, University Health Network, Toronto, Ontario, Canada
| | - Mohammed Ali Azam
- Hull Family Cardiac Fibrillation Management Laboratory, Toronto General Hospital, University Health Network, Toronto, Ontario, Canada
| | - Stéphane Massé
- Hull Family Cardiac Fibrillation Management Laboratory, Toronto General Hospital, University Health Network, Toronto, Ontario, Canada
| | - Patrick F.H. Lai
- Hull Family Cardiac Fibrillation Management Laboratory, Toronto General Hospital, University Health Network, Toronto, Ontario, Canada
| | - Robert A. Rose
- Libin Cardiovascular Institute of Alberta, University of Calgary, Calgary, Alberta, Canada
| | - Carlos A. Ibarra Moreno
- Malignant Hyperthermia Investigation Unit, Department of Anesthesiology and Pain Medicine, Toronto General Hospital, University Health Network, Toronto, Ontario, Canada
| | - Sheila Riazi
- Malignant Hyperthermia Investigation Unit, Department of Anesthesiology and Pain Medicine, Toronto General Hospital, University Health Network, Toronto, Ontario, Canada
| | - Kumaraswamy Nanthakumar
- Hull Family Cardiac Fibrillation Management Laboratory, Toronto General Hospital, University Health Network, Toronto, Ontario, Canada
| |
Collapse
|
2
|
Hu Y, Cang J, Hiraishi K, Fujita T, Inoue R. The Role of TRPM4 in Cardiac Electrophysiology and Arrhythmogenesis. Int J Mol Sci 2023; 24:11798. [PMID: 37511555 PMCID: PMC10380800 DOI: 10.3390/ijms241411798] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Revised: 07/20/2023] [Accepted: 07/20/2023] [Indexed: 07/30/2023] Open
Abstract
The transient receptor potential melastatin 4 (TRPM4) channel is a non-selective cation channel that activates in response to increased intracellular Ca2+ levels but does not allow Ca2+ to pass through directly. It plays a crucial role in regulating diverse cellular functions associated with intracellular Ca2+ homeostasis/dynamics. TRPM4 is widely expressed in the heart and is involved in various physiological and pathological processes therein. Specifically, it has a significant impact on the electrical activity of cardiomyocytes by depolarizing the membrane, presumably via Na+ loading. The TRPM4 channel likely contributes to the development of cardiac arrhythmias associated with specific genetic backgrounds and cardiac remodeling. This short review aims to overview what is known so far about the TRPM4 channel in cardiac electrophysiology and arrhythmogenesis, highlighting its potential as a novel therapeutic target to effectively prevent and treat cardiac arrhythmias.
Collapse
Affiliation(s)
- Yaopeng Hu
- Department of Physiology, Fukuoka University School of Medicine, Fukuoka 814-0180, Japan
| | - Jiehui Cang
- Department of Physiology, Fukuoka University School of Medicine, Fukuoka 814-0180, Japan
| | - Keizo Hiraishi
- Department of Physiology, Fukuoka University School of Medicine, Fukuoka 814-0180, Japan
| | - Takayuki Fujita
- Department of Physiology, Fukuoka University School of Medicine, Fukuoka 814-0180, Japan
| | - Ryuji Inoue
- Department of Physiology, Fukuoka University School of Medicine, Fukuoka 814-0180, Japan
| |
Collapse
|
3
|
Welcome MO, Dogo D, Nikos E Mastorakis. Cellular mechanisms and molecular pathways linking bitter taste receptor signalling to cardiac inflammation, oxidative stress, arrhythmia and contractile dysfunction in heart diseases. Inflammopharmacology 2023; 31:89-117. [PMID: 36471190 PMCID: PMC9734786 DOI: 10.1007/s10787-022-01086-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2022] [Accepted: 10/11/2022] [Indexed: 12/12/2022]
Abstract
Heart diseases and related complications constitute a leading cause of death and socioeconomic threat worldwide. Despite intense efforts and research on the pathogenetic mechanisms of these diseases, the underlying cellular and molecular mechanisms are yet to be completely understood. Several lines of evidence indicate a critical role of inflammatory and oxidative stress responses in the development and progression of heart diseases. Nevertheless, the molecular machinery that drives cardiac inflammation and oxidative stress is not completely known. Recent data suggest an important role of cardiac bitter taste receptors (TAS2Rs) in the pathogenetic mechanism of heart diseases. Independent groups of researchers have demonstrated a central role of TAS2Rs in mediating inflammatory, oxidative stress responses, autophagy, impulse generation/propagation and contractile activities in the heart, suggesting that dysfunctional TAS2R signalling may predispose to cardiac inflammatory and oxidative stress disorders, characterised by contractile dysfunction and arrhythmia. Moreover, cardiac TAS2Rs act as gateway surveillance units that monitor and detect toxigenic or pathogenic molecules, including microbial components, and initiate responses that ultimately culminate in protection of the host against the aggression. Unfortunately, however, the molecular mechanisms that link TAS2R sensing of the cardiac milieu to inflammatory and oxidative stress responses are not clearly known. Therefore, we sought to review the possible role of TAS2R signalling in the pathophysiology of cardiac inflammation, oxidative stress, arrhythmia and contractile dysfunction in heart diseases. Potential therapeutic significance of targeting TAS2R or its downstream signalling molecules in cardiac inflammation, oxidative stress, arrhythmia and contractile dysfunction is also discussed.
Collapse
Affiliation(s)
- Menizibeya O Welcome
- Department of Physiology, Faculty of Basic Medical Sciences, College of Health Sciences, Nile University of Nigeria, Plot 681 Cadastral Zone, C-00 Research and Institution Area, Jabi Airport Road Bypass, FCT, Abuja, Nigeria.
| | - Dilli Dogo
- Department of Surgery, Faculty of Clinical Sciences, College of Health Sciences, Nile University of Nigeria, Abuja, Nigeria
| | - Nikos E Mastorakis
- Technical University of Sofia, Klement Ohridksi 8, Sofia, 1000, Bulgaria
| |
Collapse
|
4
|
Mirbod SM, Khanahmad H, Amerizadeh A, Amirpour A, Mirbod SM, Zaker E. Viewpoints on the Role of Transient Receptor Potential Melastatin Channels in Cardiovascular System and Disease: A Systematic Review. Curr Probl Cardiol 2023; 48:101012. [PMID: 34644560 DOI: 10.1016/j.cpcardiol.2021.101012] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Accepted: 08/08/2021] [Indexed: 01/04/2023]
Abstract
Transient receptor potential (TRP) family play critical roles in cardiovascular system. TRPM family as largest TRP subfamily is non-voltage Ca2+-activated selective channels which has 8 members. This study aimed to discuss the role of TRPM family in cardiovascular system and diseases. Systematic search was performed covering PubMed, ISI Web of Science, and Google Scholar from inception until June 2021 using related keywords and Mesh terms for English studies with human, animal and in-vitro subjects. Finally 10 studies were selected for data extraction. Reviewing the articles showed that TRPM2, TRPM4, TRPM5, TRPM6 and TRPM7 play important roles in cardiovascular system and diseases. TRPM2 could be activated by reactive oxygen species (ROS) and effects on cardiac injury and cardiac fibrosis. TRPM7 and TRPM6 also have been reported to be associated with cardiac fibrosis and atrial fibrosis development respectively. TRPM4 channels contributed to resting membrane potential of cerebral artery smooth muscle cells and atrial contraction. TRPM5 channels are bitter taste sensors and prevent high salt intake and consequently high blood pressure due to the high salt intake. In conclusion based on the proof of the effectiveness of some members of TRPM family in the cardiovascular system, research on other members of this channel group seems to be useful and necessary to find their possible connection to the cardiovascular system.
Collapse
Affiliation(s)
| | - Hossein Khanahmad
- Department of Genetics and Molecular biology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Atefeh Amerizadeh
- Department of Cardiology, Isfahan University of Medical Sciences, Isfahan, Iran; Applied Physiology Research Center, Department of Physiology, Cardiovascular Research Institute, Isfahan University of Medical sciences, Isfahan, Iran
| | - Afshin Amirpour
- Cardiac Rehabilitation Research Center, Cardiovascular Research Institute, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Seyedeh Mojgan Mirbod
- Heart Failure Research Center, Cardiovascular Research Institute, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Erfan Zaker
- Department of Genetics and Molecular biology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran
| |
Collapse
|
5
|
Li R, Huang W. Yes-Associated Protein and Transcriptional Coactivator with PDZ-Binding Motif in Cardiovascular Diseases. Int J Mol Sci 2023; 24:ijms24021666. [PMID: 36675179 PMCID: PMC9861006 DOI: 10.3390/ijms24021666] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Revised: 01/08/2023] [Accepted: 01/10/2023] [Indexed: 01/18/2023] Open
Abstract
Yes-associated protein (YAP, also known as YAP1) and its paralogue TAZ (with a PDZ-binding motif) are transcriptional coactivators that switch between the cytoplasm and nucleus and regulate the organ size and tissue homeostasis. This review focuses on the research progress on YAP/TAZ signaling proteins in myocardial infarction, cardiac remodeling, hypertension and coronary heart disease, cardiomyopathy, and aortic disease. Based on preclinical studies on YAP/TAZ signaling proteins in cellular/animal models and clinical patients, the potential roles of YAP/TAZ proteins in some cardiovascular diseases (CVDs) are summarized.
Collapse
|
6
|
Chen J, Chang Y, Zhu J, Peng Y, Li Z, Zhang K, Zhang Y, Lin C, Lin Z, Pan S, Huang K. Flufenamic acid improves survival and neurologic outcome after successful cardiopulmonary resuscitation in mice. J Neuroinflammation 2022; 19:214. [PMID: 36050694 PMCID: PMC9438280 DOI: 10.1186/s12974-022-02571-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2022] [Accepted: 08/19/2022] [Indexed: 11/10/2022] Open
Abstract
Background Brain injury is the main cause of high mortality and disability after successful cardiopulmonary resuscitation (CPR) from sudden cardiac arrest (CA). The transient receptor potential M4 (TRPM4) channel is a novel target for ameliorating blood–brain barrier (BBB) disruption and neuroinflammation. Herein, we tested whether flufenamic acid (FFA), which is reported to block TRPM4 with high potency, could confer neuroprotection against brain injury secondary to CA/CPR and whether its action was exerted by blocking the TRPM4 channel. Methods Wild-type (WT) and Trpm4 knockout (Trpm4−/−) mice subjected to 10-min CA/CPR were randomized to receive FFA or vehicle once daily. Post-CA/CPR brain injuries including neurologic deficits, survival rate, histological damage, edema formation, BBB destabilization and neuroinflammation were assessed. Results In WT mice subjected to CA/CPR, FFA was effective in improving survival and neurologic outcome, reducing neuropathological injuries, attenuating brain edema, lessening the leakage of IgG and Evans blue dye, restoring tight junction protein expression and promoting microglia/macrophages from the pro-inflammatory subtype toward the anti-inflammatory subtype. In comparison to WT mice, Trpm4−/− mice exhibited less neurologic deficiency, milder histological impairment, more BBB integrity and more anti-inflammatory microglia/macrophage polarization. As expected, FFA did not provide a benefit of superposition compared with vehicle in the Trpm4−/− mice after CA/CPR. Conclusions FFA mitigates BBB breach and modifies the functional status of microglia/macrophages, thereby improving survival and neurologic deficits following CA/CPR. The neuroprotective effects occur at least partially by interfering with the TRPM4 channel in the neurovascular unit. These results indicate the significant clinical potential of FFA to improve the prognosis for CA victims who are successfully resuscitated. Supplementary Information The online version contains supplementary material available at 10.1186/s12974-022-02571-2.
Collapse
Affiliation(s)
- Jiancong Chen
- Department of Neurology, Nanfang Hospital, Southern Medical University, Guangzhou North Avenue, Guangzhou, 1838#510515, China
| | - Yuan Chang
- Department of Neurology, Nanfang Hospital, Southern Medical University, Guangzhou North Avenue, Guangzhou, 1838#510515, China
| | - Juan Zhu
- Department of Neurology, Nanfang Hospital, Southern Medical University, Guangzhou North Avenue, Guangzhou, 1838#510515, China
| | - Yuqin Peng
- Department of Neurology, Nanfang Hospital, Southern Medical University, Guangzhou North Avenue, Guangzhou, 1838#510515, China
| | - Zheqi Li
- Department of Neurology, Nanfang Hospital, Southern Medical University, Guangzhou North Avenue, Guangzhou, 1838#510515, China
| | - Kunxue Zhang
- Department of Neurology, Nanfang Hospital, Southern Medical University, Guangzhou North Avenue, Guangzhou, 1838#510515, China
| | - Yuzhen Zhang
- Department of Neurology, Nanfang Hospital, Southern Medical University, Guangzhou North Avenue, Guangzhou, 1838#510515, China
| | - Chuman Lin
- Department of Neurology, Nanfang Hospital, Southern Medical University, Guangzhou North Avenue, Guangzhou, 1838#510515, China
| | - Zhenzhou Lin
- Department of Neurology, Nanfang Hospital, Southern Medical University, Guangzhou North Avenue, Guangzhou, 1838#510515, China
| | - Suyue Pan
- Department of Neurology, Nanfang Hospital, Southern Medical University, Guangzhou North Avenue, Guangzhou, 1838#510515, China.
| | - Kaibin Huang
- Department of Neurology, Nanfang Hospital, Southern Medical University, Guangzhou North Avenue, Guangzhou, 1838#510515, China.
| |
Collapse
|
7
|
Malysz J, Maxwell SE, Petkov GV. Differential effects of TRPM4 channel inhibitors on Guinea pig urinary bladder smooth muscle excitability and contractility: Novel 4-chloro-2-[2-(2-chloro-phenoxy)-acetylamino]-benzoic acid (CBA) versus classical 9-phenanthrol. Pharmacol Res Perspect 2022; 10:e00982. [PMID: 35822549 PMCID: PMC9277609 DOI: 10.1002/prp2.982] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2022] [Accepted: 05/24/2022] [Indexed: 11/06/2022] Open
Abstract
Non-selective cation channels in urinary bladder smooth muscle (UBSM) are thought to mediate increases in cellular excitability and contractility. For transient receptor potential melastatin type-4 (TRPM4) channels, the evidence primarily relies on the inhibitor 9-phenanthrol, which exhibits pharmacological limitations. Recently, 4-chloro-2-[2-(2-chloro-phenoxy)-acetylamino]-benzoic acid (CBA) has been discovered as a novel TRPM4 channel blocker. We examined how, in comparison to 9-phenanthrol, CBA affects the excitability of freshly isolated guinea pig UBSM cells and the contractility of UBSM strips. Additionally, non-selective TRPM4 channel inhibitor flufenamic acid (FFA) and potentiator BTP2 (also known as YM-58483) were studied in UBSM cells. Unlike robust inhibition for 9-phenanthrol already known, CBA (up to 100 μM) displayed either no or a very weak reduction (<20%) in spontaneous phasic, 20 mM KCl-induced, and electrical field stimulated contractions. For 300 μM CBA, reductions were higher except for an increase in the frequency of KCl-induced contractions. In UBSM cells, examined under amphotericin B-perforated patch-clamp, CBA (30 μM) did not affect the membrane potential (I = 0) or voltage step-induced whole-cell cation currents, sensitive to 9-phenanthrol. The currents were not inhibited by FFA (100 μM), increased by BTP2 (10 μM), nor enhanced under a strongly depolarizing holding voltage of -16 or + 6 mV (vs. -74 mV). None of the three compounds affected the cell capacitance, unlike 9-phenanthrol. In summary, the novel inhibitor CBA and nonselective FFA did not mimic the inhibitory properties of 9-phenanthrol on UBSM function. These results suggest that TRPM4 channels, although expressed in UBSM, play a distinct role rather than direct regulation of excitability and contractility.
Collapse
Affiliation(s)
- John Malysz
- Department of Pharmaceutical Sciences, College of PharmacyUniversity of Tennessee Health Science CenterMemphisTennesseeUSA
- Present address:
Department of Physiology and Cell BiologyUniversity of NevadaRenoNevadaUSA
| | - Sarah E. Maxwell
- Department of Pharmaceutical Sciences, College of PharmacyUniversity of Tennessee Health Science CenterMemphisTennesseeUSA
| | - Georgi V. Petkov
- Department of Pharmaceutical Sciences, College of PharmacyUniversity of Tennessee Health Science CenterMemphisTennesseeUSA
| |
Collapse
|
8
|
Yarishkin O, Phuong TTT, Vazquez-Chona F, Bertrand J, van Battenburg-Sherwood J, Redmon SN, Rudzitis CN, Lakk M, Baumann JM, Freichel M, Hwang EM, Overby D, Križaj D. Emergent Temporal Signaling in Human Trabecular Meshwork Cells: Role of TRPV4-TRPM4 Interactions. Front Immunol 2022; 13:805076. [PMID: 35432302 PMCID: PMC9008486 DOI: 10.3389/fimmu.2022.805076] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Accepted: 03/02/2022] [Indexed: 11/26/2022] Open
Abstract
Trabecular meshwork (TM) cells are phagocytic cells that employ mechanotransduction to actively regulate intraocular pressure. Similar to macrophages, they express scavenger receptors and participate in antigen presentation within the immunosuppressive milieu of the anterior eye. Changes in pressure deform and compress the TM, altering their control of aqueous humor outflow but it is not known whether transducer activation shapes temporal signaling. The present study combines electrophysiology, histochemistry and functional imaging with gene silencing and heterologous expression to gain insight into Ca2+ signaling downstream from TRPV4 (Transient Receptor Potential Vanilloid 4), a stretch-activated polymodal cation channel. Human TM cells respond to the TRPV4 agonist GSK1016790A with fluctuations in intracellular Ca2+ concentration ([Ca2+]i) and an increase in [Na+]i. [Ca2+]i oscillations coincided with monovalent cation current that was suppressed by BAPTA, Ruthenium Red and the TRPM4 (Transient Receptor Potential Melastatin 4) channel inhibitor 9-phenanthrol. TM cells expressed TRPM4 mRNA, protein at the expected 130-150 kDa and showed punctate TRPM4 immunoreactivity at the membrane surface. Genetic silencing of TRPM4 antagonized TRPV4-evoked oscillatory signaling whereas TRPV4 and TRPM4 co-expression in HEK-293 cells reconstituted the oscillations. Membrane potential recordings suggested that TRPM4-dependent oscillations require release of Ca2+ from internal stores. 9-phenanthrol did not affect the outflow facility in mouse eyes and eyes from animals lacking TRPM4 had normal intraocular pressure. Collectively, our results show that TRPV4 activity initiates dynamic calcium signaling in TM cells by stimulating TRPM4 channels and intracellular Ca2+ release. It is possible that TRPV4-TRPM4 interactions downstream from the tensile and compressive impact of intraocular pressure contribute to homeostatic regulation and pathological remodeling within the conventional outflow pathway.
Collapse
Affiliation(s)
- Oleg Yarishkin
- Department of Ophthalmology and Visual Sciences, University of Utah School of Medicine, Salt Lake City, United States
| | - Tam T T Phuong
- Department of Ophthalmology and Visual Sciences, University of Utah School of Medicine, Salt Lake City, United States
| | - Felix Vazquez-Chona
- Department of Ophthalmology and Visual Sciences, University of Utah School of Medicine, Salt Lake City, United States
| | - Jacques Bertrand
- Department of Bioengineering, Imperial College London, London, United Kingdom
| | | | - Sarah N Redmon
- Department of Ophthalmology and Visual Sciences, University of Utah School of Medicine, Salt Lake City, United States
| | - Christopher N Rudzitis
- Department of Ophthalmology and Visual Sciences, University of Utah School of Medicine, Salt Lake City, United States.,Interdepartmental Program in Neuroscience, University of Utah, Salt Lake City, United States
| | - Monika Lakk
- Department of Ophthalmology and Visual Sciences, University of Utah School of Medicine, Salt Lake City, United States
| | - Jackson M Baumann
- Department of Ophthalmology and Visual Sciences, University of Utah School of Medicine, Salt Lake City, United States.,Department of Bioengineering, University of Utah, Salt Lake City, United States
| | - Marc Freichel
- Institute of Pharmacology, Heidelberg University, Heidelberg, Germany
| | - Eun-Mi Hwang
- Center for Functional Connectomics, Korea Institute of Science and Technology (KIST), Seoul, South Korea
| | - Darryl Overby
- Department of Bioengineering, Imperial College London, London, United Kingdom
| | - David Križaj
- Department of Ophthalmology and Visual Sciences, University of Utah School of Medicine, Salt Lake City, United States.,Interdepartmental Program in Neuroscience, University of Utah, Salt Lake City, United States.,Department of Bioengineering, University of Utah, Salt Lake City, United States.,Department of Neurobiology, University of Utah, Salt Lake City, United States
| |
Collapse
|
9
|
Kovács ZM, Dienes C, Hézső T, Almássy J, Magyar J, Bányász T, Nánási PP, Horváth B, Szentandrássy N. Pharmacological Modulation and (Patho)Physiological Roles of TRPM4 Channel—Part 1: Modulation of TRPM4. Pharmaceuticals (Basel) 2022; 15:ph15010081. [PMID: 35056138 PMCID: PMC8781449 DOI: 10.3390/ph15010081] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Accepted: 01/06/2022] [Indexed: 02/06/2023] Open
Abstract
Transient receptor potential melastatin 4 is a unique member of the TRPM protein family and, similarly to TRPM5, is Ca2+-sensitive and permeable to monovalent but not divalent cations. It is widely expressed in many organs and is involved in several functions by regulating the membrane potential and Ca2+ homeostasis in both excitable and non-excitable cells. This part of the review discusses the pharmacological modulation of TRPM4 by listing, comparing, and describing both endogenous and exogenous activators and inhibitors of the ion channel. Moreover, other strategies used to study TRPM4 functions are listed and described. These strategies include siRNA-mediated silencing of TRPM4, dominant-negative TRPM4 variants, and anti-TRPM4 antibodies. TRPM4 is receiving more and more attention and is likely to be the topic of research in the future.
Collapse
Affiliation(s)
- Zsigmond Máté Kovács
- Department of Physiology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary; (Z.M.K.); (C.D.); (T.H.); (J.A.); (J.M.); (T.B.); (P.P.N.); (B.H.)
- Doctoral School of Molecular Medicine, University of Debrecen, 4032 Debrecen, Hungary
| | - Csaba Dienes
- Department of Physiology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary; (Z.M.K.); (C.D.); (T.H.); (J.A.); (J.M.); (T.B.); (P.P.N.); (B.H.)
- Doctoral School of Molecular Medicine, University of Debrecen, 4032 Debrecen, Hungary
| | - Tamás Hézső
- Department of Physiology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary; (Z.M.K.); (C.D.); (T.H.); (J.A.); (J.M.); (T.B.); (P.P.N.); (B.H.)
- Doctoral School of Molecular Medicine, University of Debrecen, 4032 Debrecen, Hungary
| | - János Almássy
- Department of Physiology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary; (Z.M.K.); (C.D.); (T.H.); (J.A.); (J.M.); (T.B.); (P.P.N.); (B.H.)
| | - János Magyar
- Department of Physiology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary; (Z.M.K.); (C.D.); (T.H.); (J.A.); (J.M.); (T.B.); (P.P.N.); (B.H.)
- Division of Sport Physiology, Department of Physiology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary
| | - Tamás Bányász
- Department of Physiology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary; (Z.M.K.); (C.D.); (T.H.); (J.A.); (J.M.); (T.B.); (P.P.N.); (B.H.)
| | - Péter P. Nánási
- Department of Physiology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary; (Z.M.K.); (C.D.); (T.H.); (J.A.); (J.M.); (T.B.); (P.P.N.); (B.H.)
- Department of Dental Physiology and Pharmacology, Faculty of Dentistry, University of Debrecen, 4032 Debrecen, Hungary
| | - Balázs Horváth
- Department of Physiology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary; (Z.M.K.); (C.D.); (T.H.); (J.A.); (J.M.); (T.B.); (P.P.N.); (B.H.)
- Faculty of Pharmacy, University of Debrecen, 4032 Debrecen, Hungary
| | - Norbert Szentandrássy
- Department of Physiology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary; (Z.M.K.); (C.D.); (T.H.); (J.A.); (J.M.); (T.B.); (P.P.N.); (B.H.)
- Department of Basic Medical Sciences, Faculty of Dentistry, University of Debrecen, 4032 Debrecen, Hungary
- Correspondence:
| |
Collapse
|
10
|
Pharmacological Modulation and (Patho)Physiological Roles of TRPM4 Channel-Part 2: TRPM4 in Health and Disease. Pharmaceuticals (Basel) 2021; 15:ph15010040. [PMID: 35056097 PMCID: PMC8779181 DOI: 10.3390/ph15010040] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Revised: 12/21/2021] [Accepted: 12/22/2021] [Indexed: 02/06/2023] Open
Abstract
Transient receptor potential melastatin 4 (TRPM4) is a unique member of the TRPM protein family and, similarly to TRPM5, is Ca2+ sensitive and permeable for monovalent but not divalent cations. It is widely expressed in many organs and is involved in several functions; it regulates membrane potential and Ca2+ homeostasis in both excitable and non-excitable cells. This part of the review discusses the currently available knowledge about the physiological and pathophysiological roles of TRPM4 in various tissues. These include the physiological functions of TRPM4 in the cells of the Langerhans islets of the pancreas, in various immune functions, in the regulation of vascular tone, in respiratory and other neuronal activities, in chemosensation, and in renal and cardiac physiology. TRPM4 contributes to pathological conditions such as overactive bladder, endothelial dysfunction, various types of malignant diseases and central nervous system conditions including stroke and injuries as well as in cardiac conditions such as arrhythmias, hypertrophy, and ischemia-reperfusion injuries. TRPM4 claims more and more attention and is likely to be the topic of research in the future.
Collapse
|
11
|
Trpm5 channels encode bistability of spinal motoneurons and ensure motor control of hindlimbs in mice. Nat Commun 2021; 12:6815. [PMID: 34819493 PMCID: PMC8613399 DOI: 10.1038/s41467-021-27113-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2021] [Accepted: 11/02/2021] [Indexed: 11/09/2022] Open
Abstract
Bistable motoneurons of the spinal cord exhibit warmth-activated plateau potential driven by Na+ and triggered by a brief excitation. The thermoregulating molecular mechanisms of bistability and their role in motor functions remain unknown. Here, we identify thermosensitive Na+-permeable Trpm5 channels as the main molecular players for bistability in mouse motoneurons. Pharmacological, genetic or computational inhibition of Trpm5 occlude bistable-related properties (slow afterdepolarization, windup, plateau potentials) and reduce spinal locomotor outputs while central pattern generators for locomotion operate normally. At cellular level, Trpm5 is activated by a ryanodine-mediated Ca2+ release and turned off by Ca2+ reuptake through the sarco/endoplasmic reticulum Ca2+-ATPase (SERCA) pump. Mice in which Trpm5 is genetically silenced in most lumbar motoneurons develop hindlimb paresis and show difficulties in executing high-demanding locomotor tasks. Overall, by encoding bistability in motoneurons, Trpm5 appears indispensable for producing a postural tone in hindlimbs and amplifying the locomotor output.
Collapse
|
12
|
Dienes C, Hézső T, Kiss DZ, Baranyai D, Kovács ZM, Szabó L, Magyar J, Bányász T, Nánási PP, Horváth B, Gönczi M, Szentandrássy N. Electrophysiological Effects of the Transient Receptor Potential Melastatin 4 Channel Inhibitor (4-Chloro-2-(2-chlorophenoxy)acetamido) Benzoic Acid (CBA) in Canine Left Ventricular Cardiomyocytes. Int J Mol Sci 2021; 22:ijms22179499. [PMID: 34502410 PMCID: PMC8430982 DOI: 10.3390/ijms22179499] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Revised: 07/23/2021] [Accepted: 08/27/2021] [Indexed: 01/16/2023] Open
Abstract
Transient receptor potential melastatin 4 (TRPM4) plays an important role in many tissues, including pacemaker and conductive tissues of the heart, but much less is known about its electrophysiological role in ventricular myocytes. Our earlier results showed the lack of selectivity of 9-phenanthrol, so CBA ((4-chloro-2-(2-chlorophenoxy)acetamido) benzoic acid) was chosen as a new, potentially selective inhibitor. Goal: Our aim was to elucidate the effect and selectivity of CBA in canine left ventricular cardiomyocytes and to study the expression of TRPM4 in the canine heart. Experiments were carried out in enzymatically isolated canine left ventricular cardiomyocytes. Ionic currents were recorded with an action potential (AP) voltage-clamp technique in whole-cell configuration at 37 °C. An amount of 10 mM BAPTA was used in the pipette solution to exclude the potential activation of TRPM4 channels. AP was recorded with conventional sharp microelectrodes. CBA was used in 10 µM concentrations. Expression of TRPM4 protein in the heart was studied by Western blot. TRPM4 protein was expressed in the wall of all four chambers of the canine heart as well as in samples prepared from isolated left ventricular cells. CBA induced an approximately 9% reduction in AP duration measured at 75% and 90% of repolarization and decreased the short-term variability of APD90. Moreover, AP amplitude was increased and the maximal rates of phase 0 and 1 were reduced by the drug. In AP clamp measurements, CBA-sensitive current contained a short, early outward and mainly a long, inward current. Transient outward potassium current (Ito) and late sodium current (INa,L) were reduced by approximately 20% and 47%, respectively, in the presence of CBA, while L-type calcium and inward rectifier potassium currents were not affected. These effects of CBA were largely reversible upon washout. Based on our results, the CBA induced reduction of phase-1 slope and the slight increase of AP amplitude could have been due to the inhibition of Ito. The tendency for AP shortening can be explained by the inhibition of inward currents seen in AP-clamp recordings during the plateau phase. This inward current reduced by CBA is possibly INa,L, therefore, CBA is not entirely selective for TRPM4 channels. As a consequence, similarly to 9-phenanthrol, it cannot be used to test the contribution of TRPM4 channels to cardiac electrophysiology in ventricular cells, or at least caution must be applied.
Collapse
Affiliation(s)
- Csaba Dienes
- Department of Physiology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary; (C.D.); (T.H.); (D.Z.K.); (D.B.); (Z.M.K.); (L.S.); (J.M.); (T.B.); (P.P.N.); (B.H.); (M.G.)
- Doctoral School of Molecular Medicine, University of Debrecen, 4032 Debrecen, Hungary
| | - Tamás Hézső
- Department of Physiology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary; (C.D.); (T.H.); (D.Z.K.); (D.B.); (Z.M.K.); (L.S.); (J.M.); (T.B.); (P.P.N.); (B.H.); (M.G.)
- Doctoral School of Molecular Medicine, University of Debrecen, 4032 Debrecen, Hungary
| | - Dénes Zsolt Kiss
- Department of Physiology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary; (C.D.); (T.H.); (D.Z.K.); (D.B.); (Z.M.K.); (L.S.); (J.M.); (T.B.); (P.P.N.); (B.H.); (M.G.)
- Doctoral School of Molecular Medicine, University of Debrecen, 4032 Debrecen, Hungary
| | - Dóra Baranyai
- Department of Physiology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary; (C.D.); (T.H.); (D.Z.K.); (D.B.); (Z.M.K.); (L.S.); (J.M.); (T.B.); (P.P.N.); (B.H.); (M.G.)
- Doctoral School of Molecular Medicine, University of Debrecen, 4032 Debrecen, Hungary
| | - Zsigmond Máté Kovács
- Department of Physiology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary; (C.D.); (T.H.); (D.Z.K.); (D.B.); (Z.M.K.); (L.S.); (J.M.); (T.B.); (P.P.N.); (B.H.); (M.G.)
- Doctoral School of Molecular Medicine, University of Debrecen, 4032 Debrecen, Hungary
| | - László Szabó
- Department of Physiology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary; (C.D.); (T.H.); (D.Z.K.); (D.B.); (Z.M.K.); (L.S.); (J.M.); (T.B.); (P.P.N.); (B.H.); (M.G.)
- Doctoral School of Molecular Medicine, University of Debrecen, 4032 Debrecen, Hungary
| | - János Magyar
- Department of Physiology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary; (C.D.); (T.H.); (D.Z.K.); (D.B.); (Z.M.K.); (L.S.); (J.M.); (T.B.); (P.P.N.); (B.H.); (M.G.)
- Division of Sport Physiology, Department of Physiology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary
| | - Tamás Bányász
- Department of Physiology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary; (C.D.); (T.H.); (D.Z.K.); (D.B.); (Z.M.K.); (L.S.); (J.M.); (T.B.); (P.P.N.); (B.H.); (M.G.)
| | - Péter P. Nánási
- Department of Physiology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary; (C.D.); (T.H.); (D.Z.K.); (D.B.); (Z.M.K.); (L.S.); (J.M.); (T.B.); (P.P.N.); (B.H.); (M.G.)
- Department of Dental Physiology and Pharmacology, Faculty of Dentistry, University of Debrecen, 4032 Debrecen, Hungary
| | - Balázs Horváth
- Department of Physiology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary; (C.D.); (T.H.); (D.Z.K.); (D.B.); (Z.M.K.); (L.S.); (J.M.); (T.B.); (P.P.N.); (B.H.); (M.G.)
- Faculty of Pharmacy, University of Debrecen, 4032 Debrecen, Hungary
| | - Mónika Gönczi
- Department of Physiology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary; (C.D.); (T.H.); (D.Z.K.); (D.B.); (Z.M.K.); (L.S.); (J.M.); (T.B.); (P.P.N.); (B.H.); (M.G.)
| | - Norbert Szentandrássy
- Department of Physiology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary; (C.D.); (T.H.); (D.Z.K.); (D.B.); (Z.M.K.); (L.S.); (J.M.); (T.B.); (P.P.N.); (B.H.); (M.G.)
- Department of Basic Medical Sciences, Faculty of Dentistry, University of Debrecen, 4032 Debrecen, Hungary
- Correspondence: ; Tel.: +36-52255575; Fax: +36-52255116
| |
Collapse
|
13
|
Veteto AB, Peana D, Lambert MD, McDonald KS, Domeier TL. Transient receptor potential vanilloid-4 contributes to stretch-induced hypercontractility and time-dependent dysfunction in the aged heart. Cardiovasc Res 2021; 116:1887-1896. [PMID: 31693106 DOI: 10.1093/cvr/cvz287] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/01/2019] [Revised: 09/29/2019] [Accepted: 11/04/2019] [Indexed: 01/06/2023] Open
Abstract
AIMS Cardiovascular disease remains the greatest cause of mortality in Americans over 65. The stretch-activated transient receptor potential vanilloid-4 (TRPV4) ion channel is expressed in cardiomyocytes of the aged heart. This investigation tests the hypothesis that TRPV4 alters Ca2+ handling and cardiac function in response to increased ventricular preload and cardiomyocyte stretch. METHODS AND RESULTS Left ventricular maximal pressure (PMax) was monitored in isolated working hearts of Aged (24-27 months) mice following preload elevation from 5 to 20mmHg, with and without TRPV4 antagonist HC067047 (HC, 1 µmol/L). In preload responsive hearts, PMax prior to and immediately following preload elevation (i.e. Frank-Starling response) was similar between Aged and Aged+HC. Within 1 min following preload elevation, Aged hearts demonstrated secondary PMax augmentation (Aged>Aged+HC) suggesting a role for stretch-activated TRPV4 in cardiac hypercontractility. However, after 20 min at 20 mmHg Aged exhibited depressed PMax (Aged<Aged+HC) suggestive of TRPV4-dependent contractile dysfunction with sustained stretch. To examine stretch-induced Ca2+ homeostasis at the single-cell level, isolated cardiomyocytes were stretched 10-15% of slack length while measuring intracellular Ca2+ with fura-2. Uniaxial longitudinal stretch increased intracellular Ca2+ levels and triggered Ca2+ overload and terminal cellular contracture in Aged, but not Aged+HC. Preload elevation in hearts of young/middle-age (3-12 months) mice produced an initial PMax increase (Frank-Starling response) without secondary PMax augmentation, and cardiomyocyte stretch did not affect intracellular Ca2+ levels. Hearts of transgenic mice with cardiac-specific TRPV4 expression exhibited PMax similar to 3- to 12-month control mice prior to and immediately following preload elevation but displayed secondary PMax augmentation. Cardiomyocytes of mice with transgenic TRPV4 expression were highly sensitive to mechanical stimulation and exhibited elevated Ca2+ levels, Ca2+ overload, and terminal contracture upon cellular attachment and stretch. CONCLUSION TRPV4 contributes to a stretch-induced increase in cardiomyocyte Ca2+ and cardiac hypercontractility, yet sustained stretch leads to cardiomyocyte Ca2+ overload and contractile dysfunction in the aged heart.
Collapse
Affiliation(s)
- Adam B Veteto
- Department of Medical Pharmacology and Physiology, University of Missouri School of Medicine, 1 Hospital Drive, Columbia, MO 65212, USA
| | - Deborah Peana
- Department of Medical Pharmacology and Physiology, University of Missouri School of Medicine, 1 Hospital Drive, Columbia, MO 65212, USA
| | - Michelle D Lambert
- Department of Medical Pharmacology and Physiology, University of Missouri School of Medicine, 1 Hospital Drive, Columbia, MO 65212, USA
| | - Kerry S McDonald
- Department of Medical Pharmacology and Physiology, University of Missouri School of Medicine, 1 Hospital Drive, Columbia, MO 65212, USA
| | - Timothy L Domeier
- Department of Medical Pharmacology and Physiology, University of Missouri School of Medicine, 1 Hospital Drive, Columbia, MO 65212, USA
| |
Collapse
|
14
|
An Arrhythmic Mutation E7K Facilitates TRPM4 Channel Activation via Enhanced PIP 2 Interaction. Cells 2021; 10:cells10050983. [PMID: 33922380 PMCID: PMC8146980 DOI: 10.3390/cells10050983] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2021] [Revised: 04/16/2021] [Accepted: 04/21/2021] [Indexed: 11/17/2022] Open
Abstract
A Ca2+-activated monovalent cation-selective TRPM4 channel is abundantly expressed in the heart. Recently, a single gain-of-function mutation identified in the distal N-terminus of the human TRPM4 channel (Glu5 to Lys5; E7K) was found to be arrhythmogenic because of enhanced cell membrane expression. In this study, we conducted detailed analyses of this mutant channel from more functional aspects, in comparison with its wild type (WT). In an expression system, intracellular application of a short soluble PIP2 (diC8PIP2) restored the single-channel activities of both WT and E7K, which had quickly faded after membrane excision. The potency (Kd) of diC8PIP2 for this recovery was stronger in E7K than its WT (1.44 vs. 2.40 μM). FRET-based PIP2 measurements combined with the Danio rerio voltage-sensing phosphatase (DrVSP) and patch clamping revealed that lowering the endogenous PIP2 level by DrVSP activation reduced the TRPM4 channel activity. This effect was less prominent in E7K than its WT (apparent Kd values estimated from DrVSP-mediated PIP2 depletion: 0.97 and 1.06 μM, respectively), being associated with the differential PIP2-mediated modulation of voltage dependence. Moreover, intracellular perfusion of short N-terminal polypeptides containing either the ‘WT’ or ‘E7K’ sequences respectively attenuated the TRPM4 channel activation at whole-cell and single-channel levels, but in both configurations, the E7K polypeptide exerted greater inhibitory effects. These results collectively suggest that N-terminal interaction with endogenous PIP2 is essential for the TRPM4 channel to function, the extent of which may be abnormally strengthened by the E7K mutation through modulating voltage-dependent activation. The altered PIP2 interaction may account for the arrhythmogenic potential of this mutation.
Collapse
|
15
|
Deletion of Trpm4 Alters the Function of the Na v1.5 Channel in Murine Cardiac Myocytes. Int J Mol Sci 2021; 22:ijms22073401. [PMID: 33810249 PMCID: PMC8037196 DOI: 10.3390/ijms22073401] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Revised: 03/18/2021] [Accepted: 03/23/2021] [Indexed: 12/12/2022] Open
Abstract
Transient receptor potential melastatin member 4 (TRPM4) encodes a Ca2+-activated, non-selective cation channel that is functionally expressed in several tissues, including the heart. Pathogenic mutants in TRPM4 have been reported in patients with inherited cardiac diseases, including conduction blockage and Brugada syndrome. Heterologous expression of mutant channels in cell lines indicates that these mutations can lead to an increase or decrease in TRPM4 expression and function at the cell surface. While the expression and clinical variant studies further stress the importance of TRPM4 in cardiac function, the cardiac electrophysiological phenotypes in Trpm4 knockdown mouse models remain incompletely characterized. To study the functional consequences of Trpm4 deletion on cardiac electrical activity in mice, we performed perforated-patch clamp and immunoblotting studies on isolated atrial and ventricular cardiac myocytes and surfaces, as well as on pseudo- and intracardiac ECGs, either in vivo or in Langendorff-perfused explanted mouse hearts. We observed that TRPM4 is expressed in atrial and ventricular cardiac myocytes and that deletion of Trpm4 unexpectedly reduces the peak Na+ currents in myocytes. Hearts from Trpm4−/− mice presented increased sensitivity towards mexiletine, a Na+ channel blocker, and slower intraventricular conduction, consistent with the reduction of the peak Na+ current observed in the isolated cardiac myocytes. This study suggests that TRPM4 expression impacts the Na+ current in murine cardiac myocytes and points towards a novel function of TRPM4 regulating the Nav1.5 function in murine cardiac myocytes.
Collapse
|
16
|
Simard C, Ferchaud V, Sallé L, Milliez P, Manrique A, Alexandre J, Guinamard R. TRPM4 Participates in Aldosterone-Salt-Induced Electrical Atrial Remodeling in Mice. Cells 2021; 10:636. [PMID: 33809210 PMCID: PMC7998432 DOI: 10.3390/cells10030636] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Revised: 03/05/2021] [Accepted: 03/10/2021] [Indexed: 12/20/2022] Open
Abstract
Aldosterone plays a major role in atrial structural and electrical remodeling, in particular through Ca2+-transient perturbations and shortening of the action potential. The Ca2+-activated non-selective cation channel Transient Receptor Potential Melastatin 4 (TRPM4) participates in atrial action potential. The aim of our study was to elucidate the interactions between aldosterone and TRPM4 in atrial remodeling and arrhythmias susceptibility. Hyperaldosteronemia, combined with a high salt diet, was induced in mice by subcutaneously implanted osmotic pumps during 4 weeks, delivering aldosterone or physiological serum for control animals. The experiments were conducted in wild type animals (Trpm4+/+) as well as Trpm4 knock-out animals (Trpm4-/-). The atrial diameter measured by echocardiography was higher in Trpm4-/- compared to Trpm4+/+ animals, and hyperaldosteronemia-salt produced a dilatation in both groups. Action potentials duration and triggered arrhythmias were measured using intracellular microelectrodes on the isolated left atrium. Hyperaldosteronemia-salt prolong action potential in Trpm4-/- mice but had no effect on Trpm4+/+ mice. In the control group (no aldosterone-salt treatment), no triggered arrythmias were recorded in Trpm4+/+ mice, but a high level was detected in Trpm4-/- mice. Hyperaldosteronemia-salt enhanced the occurrence of arrhythmias (early as well as delayed-afterdepolarization) in Trpm4+/+ mice but decreased it in Trpm4-/- animals. Atrial connexin43 immunolabelling indicated their disorganization at the intercalated disks and a redistribution at the lateral side induced by hyperaldosteronemia-salt but also by Trpm4 disruption. In addition, hyperaldosteronemia-salt produced pronounced atrial endothelial thickening in both groups. Altogether, our results indicated that hyperaldosteronemia-salt and TRPM4 participate in atrial electrical and structural remodeling. It appears that TRPM4 is involved in aldosterone-induced atrial action potential shortening. In addition, TRPM4 may promote aldosterone-induced atrial arrhythmias, however, the underlying mechanisms remain to be explored.
Collapse
Affiliation(s)
| | | | | | | | | | | | - Romain Guinamard
- EA 4650, Signalisation, Electrophysiologie et Imagerie des Lésions d’Ischémie-Reperfusion Myocardique, GIP Cyceron, Université de Caen Normandie, CHU de Caen, 14032 Caen, France; (C.S.); (V.F.); (L.S.); (P.M.); (A.M.); (J.A.)
| |
Collapse
|
17
|
Maxwell SE, Leo MD, Malysz J, Petkov GV. Age-dependent decrease in TRPM4 channel expression but not trafficking alters urinary bladder smooth muscle contractility. Physiol Rep 2021; 9:e14754. [PMID: 33625779 PMCID: PMC7903938 DOI: 10.14814/phy2.14754] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Accepted: 01/20/2021] [Indexed: 11/24/2022] Open
Abstract
During development, maturation, or aging, the expression and function of urinary bladder smooth muscle (UBSM) ion channels can change, thus affecting micturition. Increasing evidence supports a novel role of transient receptor potential melastatin‐4 (TRPM4) channels in UBSM physiology. However, it remains unknown whether the functional expression of these key regulatory channels fluctuates in UBSM over different life stages. Here, we examined TRPM4 channel protein expression (Western blot) and the effects of TRPM4 channel inhibitors, 9‐phenanthrol and glibenclamide, on phasic contractions of UBSM isolated strips obtained from juvenile (UBSM‐J, 5–9 weeks old) and adult (UBSM‐A, 6–18 months old) male guinea pigs. Compared to UBSM‐J, UBSM‐A displayed a 50–70% reduction in total TRPM4 protein expression, while the surface‐to‐intracellular expression ratio (channel trafficking) remained the same in both age groups. Consistent with the reduced total TRPM4 protein expression in UBSM‐A, 9‐phenanthrol showed lower potencies and/or maximum efficacies in UBSM‐A than UBSM‐J for inhibiting amplitude and muscle force of spontaneous and 20 mM KCl‐induced phasic contractions. Compared to 9‐phenanthrol, glibenclamide also attenuated both spontaneous and KCl‐induced contractions, but with less pronounced differential effects in UBSM‐A and UBSM‐J. In both age groups, regardless of the overall reduced total TRPM4 protein expression in UBSM‐A, cell surface TRPM4 protein expression (~80%) predominated over its intracellular fraction (~20%), revealing preserved channel trafficking mechanisms toward the cell membrane. Collectively, this study reports novel findings illuminating a fundamental physiological role for TRPM4 channels in UBSM function that fluctuates with age.
Collapse
Affiliation(s)
- Sarah E Maxwell
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Tennessee Health Science Center, Memphis, TN, USA
| | - M Dennis Leo
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Tennessee Health Science Center, Memphis, TN, USA
| | - John Malysz
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Georgi V Petkov
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Tennessee Health Science Center, Memphis, TN, USA.,Department of Pharmacology, College of Medicine, University of Tennessee Health Science Center, Memphis, TN, USA.,Department of Urology, College of Medicine, University of Tennessee Health Science Center, Memphis, TN, USA
| |
Collapse
|
18
|
Hu Y, Kaschitza DR, Essers M, Arullampalam P, Fujita T, Abriel H, Inoue R. Pathological activation of CaMKII induces arrhythmogenicity through TRPM4 overactivation. Pflugers Arch 2021; 473:507-519. [PMID: 33392831 DOI: 10.1007/s00424-020-02507-w] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Revised: 12/02/2020] [Accepted: 12/16/2020] [Indexed: 12/13/2022]
Abstract
TRPM4 is a Ca2+-activated nonselective cation channel involved in cardiovascular physiology and pathophysiology. Based on cellular experiments and numerical simulations, the present study aimed to explore the potential arrhythmogenicity of CaMKII-mediated TRPM4 channel overactivation linked to Ca2+ dysregulation in the heart. The confocal immunofluorescence microscopy, western blot, and proximity ligation assay (PLA) in HL-1 atrial cardiomyocytes and/or TRPM4-expressing TSA201 cells suggested that TRPM4 and CaMKII proteins are closely localized. Co-expression of TRPM4 and CaMKIIδ or a FRET-based sensor Camui in HEK293 cells showed that the extent of TRPM4 channel activation was correlated with that of CaMKII activity, suggesting their functional interaction. Both expressions and interaction of the two proteins were greatly enhanced by angiotensin II treatment, which induced early afterdepolarizations (EADs) at the repolarization phase of action potentials (APs) recorded from HL-1 cells by the current clamp mode of patch clamp technique. This arrhythmic change disappeared after treatment with the TRPM4 channel blocker 9-phenanthrol or CaMKII inhibitor KN-62. In order to quantitatively assess how CaMKII modulates the gating behavior of TRPM4 channel, the ionomycin-permeabilized cell-attached recording was employed to obtain the voltage-dependent parameters such as steady-state open probability and time constants for activation/deactivation at different [Ca2+]i. Numerical simulations incorporating these kinetic data into a modified HL-1 model indicated that > 3-fold increase in TRPM4 current density induces EADs at the late repolarization phase and CaMKII inhibition (by KN-62) completely eliminates them. These results collectively suggest a novel arrhythmogenic mechanism involving excessive CaMKII activity that causes TRPM4 overactivation in the stressed heart.
Collapse
Affiliation(s)
- Yaopeng Hu
- Department of Physiology, Fukuoka University School of Medicine, 7-45-1 Nanakuma, Jonan-ku, Fukuoka, 814-0180, Japan.
| | - Daniela Ross Kaschitza
- Institute of Biochemistry and Molecular Medicine, National Center of Competence in Research NCCR TransCure, University of Bern, Bern, Switzerland
| | - Maria Essers
- Institute of Biochemistry and Molecular Medicine, National Center of Competence in Research NCCR TransCure, University of Bern, Bern, Switzerland
| | - Prakash Arullampalam
- Institute of Biochemistry and Molecular Medicine, National Center of Competence in Research NCCR TransCure, University of Bern, Bern, Switzerland
| | - Takayuki Fujita
- Department of Physiology, Fukuoka University School of Medicine, 7-45-1 Nanakuma, Jonan-ku, Fukuoka, 814-0180, Japan
| | - Hugues Abriel
- Institute of Biochemistry and Molecular Medicine, National Center of Competence in Research NCCR TransCure, University of Bern, Bern, Switzerland
| | - Ryuji Inoue
- Department of Physiology, Fukuoka University School of Medicine, 7-45-1 Nanakuma, Jonan-ku, Fukuoka, 814-0180, Japan.
| |
Collapse
|
19
|
Hedon C, Lambert K, Chakouri N, Thireau J, Aimond F, Cassan C, Bideaux P, Richard S, Faucherre A, Le Guennec JY, Demion M. New role of TRPM4 channel in the cardiac excitation-contraction coupling in response to physiological and pathological hypertrophy in mouse. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2020; 159:105-117. [PMID: 33031824 DOI: 10.1016/j.pbiomolbio.2020.09.006] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Revised: 09/17/2020] [Accepted: 09/23/2020] [Indexed: 11/26/2022]
Abstract
The transient receptor potential Melastatin 4 (TRPM4) channel is a calcium-activated non-selective cation channel expressed widely. In the heart, using a knock-out mouse model, the TRPM4 channel has been shown to be involved in multiple processes, including β-adrenergic regulation, cardiac conduction, action potential duration and hypertrophic adaptations. This channel was recently shown to be involved in stress-induced cardiac arrhythmias in a mouse model overexpressing TRPM4 in ventricular cardiomyocytes. However, the link between TRPM4 channel expression in ventricular cardiomyocytes, the hypertrophic response to stress and/or cellular arrhythmias has yet to be elucidated. In this present study, we induced pathological hypertrophy in response to myocardial infarction using a mouse model of Trpm4 gene invalidation, and demonstrate that TRPM4 is essential for survival. We also demonstrate that the TRPM4 is required to activate both the Akt and Calcineurin pathways. Finally, using two hypertrophy models, either a physiological response to endurance training or a pathological response to myocardial infarction, we show that TRPM4 plays a role in regulating transient calcium amplitudes and leads to the development of cellular arrhythmias potentially in cooperation with the Sodium-calcium exchange (NCX). Here, we report two functions of the TRPM4 channel: first its role in adaptive hypertrophy, and second its association with NCX could mediate transient calcium amplitudes which trigger cellular arrhythmias.
Collapse
Affiliation(s)
- Christophe Hedon
- PhyMedExp, Université de Montpellier, INSERM U1046, UMR CNRS, 9412, Montpellier, France
| | - Karen Lambert
- PhyMedExp, Université de Montpellier, INSERM U1046, UMR CNRS, 9412, Montpellier, France
| | - Nourdine Chakouri
- PhyMedExp, Université de Montpellier, INSERM U1046, UMR CNRS, 9412, Montpellier, France
| | - Jérôme Thireau
- PhyMedExp, Université de Montpellier, INSERM U1046, UMR CNRS, 9412, Montpellier, France
| | - Franck Aimond
- PhyMedExp, Université de Montpellier, INSERM U1046, UMR CNRS, 9412, Montpellier, France
| | - Cécile Cassan
- PhyMedExp, Université de Montpellier, INSERM U1046, UMR CNRS, 9412, Montpellier, France
| | - Patrice Bideaux
- PhyMedExp, Université de Montpellier, INSERM U1046, UMR CNRS, 9412, Montpellier, France
| | - Sylvain Richard
- PhyMedExp, Université de Montpellier, INSERM U1046, UMR CNRS, 9412, Montpellier, France
| | - Adèle Faucherre
- IGF, Université de Montpellier, INSERM, CNRS, Montpellier, France
| | - Jean-Yves Le Guennec
- PhyMedExp, Université de Montpellier, INSERM U1046, UMR CNRS, 9412, Montpellier, France
| | - Marie Demion
- PhyMedExp, Université de Montpellier, INSERM U1046, UMR CNRS, 9412, Montpellier, France.
| |
Collapse
|
20
|
Malysz J, Petkov GV. Urinary bladder smooth muscle ion channels: expression, function, and regulation in health and disease. Am J Physiol Renal Physiol 2020; 319:F257-F283. [PMID: 32628539 PMCID: PMC7473901 DOI: 10.1152/ajprenal.00048.2020] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Revised: 06/21/2020] [Accepted: 06/28/2020] [Indexed: 12/17/2022] Open
Abstract
Urinary bladder smooth muscle (UBSM), also known as detrusor smooth muscle, forms the bladder wall and ultimately determines the two main attributes of the organ: urine storage and voiding. The two functions are facilitated by UBSM relaxation and contraction, respectively, which depend on UBSM excitability shaped by multiple ion channels. In this review, we summarize the current understanding of key ion channels establishing and regulating UBSM excitability and contractility. They include excitation-enhancing voltage-gated Ca2+ (Cav) and transient receptor potential channels, excitation-reducing K+ channels, and still poorly understood Cl- channels. Dynamic interplay among UBSM ion channels determines the overall level of Cav channel activity. The net Ca2+ influx via Cav channels increases global intracellular Ca2+ concentration, which subsequently triggers UBSM contractility. Here, for each ion channel type, we describe UBSM tissue/cell expression (mRNA and protein) profiles and their role in regulating excitability and contractility of UBSM in various animal species, including the mouse, rat, and guinea pig, and, most importantly, humans. The currently available data reveal certain interspecies differences, which complicate the translational value of published animal research results to humans. This review highlights recent developments, findings on genetic knockout models, pharmacological data, reports on UBSM ion channel dysfunction in animal bladder disease models, and the very limited human studies currently available. Among all gaps in present-day knowledge, the unknowns on expression and functional roles for ion channels determined directly in human UBSM tissues and cells under both normal and disease conditions remain key hurdles in the field.
Collapse
Affiliation(s)
- John Malysz
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Tennessee Health Science Center, Memphis, Tennessee
| | - Georgi V Petkov
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Tennessee Health Science Center, Memphis, Tennessee
- Department of Pharmacology, College of Medicine, University of Tennessee Health Science Center, Memphis, Tennessee
- Department of Urology, College of Medicine, University of Tennessee Health Science Center, Memphis, Tennessee
| |
Collapse
|
21
|
Malysz J, Maxwell SE, Yarotskyy V, Petkov GV. TRPM4 channel inhibitors 9-phenanthrol and glibenclamide differentially decrease guinea pig detrusor smooth muscle whole-cell cation currents and phasic contractions. Am J Physiol Cell Physiol 2020; 318:C406-C421. [PMID: 31851526 DOI: 10.1152/ajpcell.00055.2019] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Nonselective cation channels, consistent with transient receptor potential melastatin-4 (TRPM4), regulate detrusor smooth muscle (DSM) function. TRPM4 channels can exist as homomers or assemble with sulfonylurea receptors (SURs) as complexes. We evaluated contributions of TRPM4/SUR-TRPM4 channels to DSM excitability and contractility by examining the effects of TRPM4/SUR-TRPM4 channel modulators 9-phenanthrol, glibenclamide, and diazoxide on freshly-isolated guinea pig DSM cells (amphotericin-B perforated patch-clamp electrophysiology) and mucosa-free DSM strips (isometric tension recordings). In DSM cells, complete removal of extracellular Na+ decreased voltage-step-induced cation (non-K+ selective) currents. At high positive membrane potentials, 9-phenanthrol at 100 μM attenuated voltage step-induced currents more effectively than at 30 μM, revealing concentration-dependent, voltage-sensitive inhibition. In comparison to 9-phenanthrol, glibenclamide (100 μM) displayed lower inhibition of cation currents. In the presence of glibenclamide (100 μM), 9-phenanthrol (100 μM) further decreased the currents. The SUR-TRPM4 complex activator diazoxide (100-300 μM) weakly inhibited the currents. 9-Phenanthrol, but not glibenclamide or diazoxide, increased cell capacitance (a cell surface area indicator). In contractility studies, glibenclamide displayed lower potencies than 9-phenanthrol attenuating spontaneous and 20 mM KCl-induced DSM phasic contractions. While both compounds showed similar maximum inhibitions on DSM spontaneous phasic contractions, glibenclamide was generally less efficacious on 20 mM KCl-induced phasic contractions. In summary, the observed differential effects of 9-phenanthrol and glibenclamide on DSM excitability and contractility support unique mechanisms for the two compounds. The data suggest that SUR-TRPM4 complexes do not contribute to DSM function. This study advances our understanding of pharmacological effects of glibenclamide and 9-phenanthrol on DSM cell cation currents.
Collapse
Affiliation(s)
- John Malysz
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Tennessee Health Science Center, Memphis, Tennessee
| | - Sarah E Maxwell
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Tennessee Health Science Center, Memphis, Tennessee
| | - Viktor Yarotskyy
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Tennessee Health Science Center, Memphis, Tennessee
| | - Georgi V Petkov
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Tennessee Health Science Center, Memphis, Tennessee
| |
Collapse
|
22
|
Hof T, Chaigne S, Récalde A, Sallé L, Brette F, Guinamard R. Transient receptor potential channels in cardiac health and disease. Nat Rev Cardiol 2020; 16:344-360. [PMID: 30664669 DOI: 10.1038/s41569-018-0145-2] [Citation(s) in RCA: 83] [Impact Index Per Article: 20.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Transient receptor potential (TRP) channels are nonselective cationic channels that are generally Ca2+ permeable and have a heterogeneous expression in the heart. In the myocardium, TRP channels participate in several physiological functions, such as modulation of action potential waveform, pacemaking, conduction, inotropy, lusitropy, Ca2+ and Mg2+ handling, store-operated Ca2+ entry, embryonic development, mitochondrial function and adaptive remodelling. Moreover, TRP channels are also involved in various pathological mechanisms, such as arrhythmias, ischaemia-reperfusion injuries, Ca2+-handling defects, fibrosis, maladaptive remodelling, inherited cardiopathies and cell death. In this Review, we present the current knowledge of the roles of TRP channels in different cardiac regions (sinus node, atria, ventricles and Purkinje fibres) and cells types (cardiomyocytes and fibroblasts) and discuss their contribution to pathophysiological mechanisms, which will help to identify the best candidates for new therapeutic targets among the cardiac TRP family.
Collapse
Affiliation(s)
- Thomas Hof
- IHU-Liryc, Electrophysiology and Heart Modeling Institute, Foundation Bordeaux Université, Pessac-Bordeaux, France.,INSERM, Centre de recherche Cardio-Thoracique de Bordeaux, U1045, Bordeaux, France.,Université Bordeaux, Centre de recherche Cardio-Thoracique de Bordeaux, U1045, Bordeaux, France
| | - Sébastien Chaigne
- IHU-Liryc, Electrophysiology and Heart Modeling Institute, Foundation Bordeaux Université, Pessac-Bordeaux, France.,INSERM, Centre de recherche Cardio-Thoracique de Bordeaux, U1045, Bordeaux, France.,Université Bordeaux, Centre de recherche Cardio-Thoracique de Bordeaux, U1045, Bordeaux, France
| | - Alice Récalde
- IHU-Liryc, Electrophysiology and Heart Modeling Institute, Foundation Bordeaux Université, Pessac-Bordeaux, France.,INSERM, Centre de recherche Cardio-Thoracique de Bordeaux, U1045, Bordeaux, France.,Université Bordeaux, Centre de recherche Cardio-Thoracique de Bordeaux, U1045, Bordeaux, France
| | - Laurent Sallé
- Normandie Université, UNICAEN, EA4650, Signalisation, Électrophysiologie et Imagerie des Lésions d'Ischémie-Reperfusion Myocardique, Caen, France
| | - Fabien Brette
- IHU-Liryc, Electrophysiology and Heart Modeling Institute, Foundation Bordeaux Université, Pessac-Bordeaux, France.,INSERM, Centre de recherche Cardio-Thoracique de Bordeaux, U1045, Bordeaux, France.,Université Bordeaux, Centre de recherche Cardio-Thoracique de Bordeaux, U1045, Bordeaux, France
| | - Romain Guinamard
- Normandie Université, UNICAEN, EA4650, Signalisation, Électrophysiologie et Imagerie des Lésions d'Ischémie-Reperfusion Myocardique, Caen, France.
| |
Collapse
|
23
|
TRPC Channels: Dysregulation and Ca 2+ Mishandling in Ischemic Heart Disease. Cells 2020; 9:cells9010173. [PMID: 31936700 PMCID: PMC7017417 DOI: 10.3390/cells9010173] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Revised: 01/03/2020] [Accepted: 01/08/2020] [Indexed: 12/17/2022] Open
Abstract
Transient receptor potential canonical (TRPC) channels are ubiquitously expressed in excitable and non-excitable cardiac cells where they sense and respond to a wide variety of physical and chemical stimuli. As other TRP channels, TRPC channels may form homo or heterotetrameric ion channels, and they can associate with other membrane receptors and ion channels to regulate intracellular calcium concentration. Dysfunctions of TRPC channels are involved in many types of cardiovascular diseases. Significant increase in the expression of different TRPC isoforms was observed in different animal models of heart infarcts and in vitro experimental models of ischemia and reperfusion. TRPC channel-mediated increase of the intracellular Ca2+ concentration seems to be required for the activation of the signaling pathway that plays minor roles in the healthy heart, but they are more relevant for cardiac responses to ischemia, such as the activation of different factors of transcription and cardiac hypertrophy, fibrosis, and angiogenesis. In this review, we highlight the current knowledge regarding TRPC implication in different cellular processes related to ischemia and reperfusion and to heart infarction.
Collapse
|
24
|
So EC, Liu PY, Lee CC, Wu SN. High Effectiveness in Actions of Carfilzomib on Delayed-Rectifier K + Current and on Spontaneous Action Potentials. Front Pharmacol 2019; 10:1163. [PMID: 31649537 PMCID: PMC6791059 DOI: 10.3389/fphar.2019.01163] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2019] [Accepted: 09/10/2019] [Indexed: 12/27/2022] Open
Abstract
Carfilzomib (CFZ, Kyprolis®) is widely recognized as an irreversible inhibitor of proteasome activity; however, its actions on ion currents in electrically excitable cells are largely unresolved. The possible actions of CFZ on ionic currents and membrane potential in pituitary GH3, A7r5 vascular smooth muscle, and heart-derived H9c2 cells were extensively investigated in this study. The presence of CFZ suppressed the amplitude of delayed-rectifier K+ current (IK(DR)) in a time-, state-, and concentration-dependent manner in pituitary GH3 cells. Based on minimal reaction scheme, the value of dissociation constant for CFZ-induced open-channel block of IK(DR) in these cells was 0.33 µM, which is similar to the IC50 value (0.32 µM) used for its efficacy on inhibition of IK(DR) amplitude. Recovery from IK(DR) block by CFZ (0.3 µM and 1 µM) could be well fitted by single exponential with 447 and 645 ms, respectively. The M-type K+ current, another type of K+ current elicited by low-threshold potential, was slightly suppressed by CFZ (1 µM). Under current-clamp condition, addition of CFZ depolarized GH3 cells, broadened the duration of action potentials as well as raised the firing frequency. In A7r5 vascular smooth muscle cells or H9c2 cardiac cells, the CFZ-induced inhibition of IK(DR) remained efficacious. Therefore, our study led us to reflect that CFZ or other structurally similar compounds should somehow act on the activity of membrane KV channels through which they influence the functional activities in different types of electrically excitable cells such as endocrine, neuroendocrine cells, smooth muscle cells, or heart cells, if similar in vivo findings occur.
Collapse
Affiliation(s)
- Edmund Cheung So
- Department of Anesthesia, An Nan Hospital, China Medical University, Tainan, Taiwan.,Graduate Institute of Medical Sciences, Chang Jung Christian University, Tainan, Taiwan
| | - Ping-Yen Liu
- Division of Cardiovascular Medicine, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Chien-Ching Lee
- Department of Anesthesia, An Nan Hospital, China Medical University, Tainan, Taiwan.,Institute of Imaging and Biomedical Photonics, National Chiao Tung University, Tainan, Taiwan
| | - Sheng-Nan Wu
- Department of Physiology, National Cheng Kung University Medical College, Tainan, Taiwan.,Institute of Basic Medical Sciences, National Cheng Kung University Medical College, Tainan, Taiwan
| |
Collapse
|
25
|
Ottolini M, Hong K, Sonkusare SK. Calcium signals that determine vascular resistance. WILEY INTERDISCIPLINARY REVIEWS. SYSTEMS BIOLOGY AND MEDICINE 2019; 11:e1448. [PMID: 30884210 PMCID: PMC6688910 DOI: 10.1002/wsbm.1448] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2018] [Revised: 02/07/2019] [Accepted: 02/14/2019] [Indexed: 12/19/2022]
Abstract
Small arteries in the body control vascular resistance, and therefore, blood pressure and blood flow. Endothelial and smooth muscle cells in the arterial walls respond to various stimuli by altering the vascular resistance on a moment to moment basis. Smooth muscle cells can directly influence arterial diameter by contracting or relaxing, whereas endothelial cells that line the inner walls of the arteries modulate the contractile state of surrounding smooth muscle cells. Cytosolic calcium is a key driver of endothelial and smooth muscle cell functions. Cytosolic calcium can be increased either by calcium release from intracellular stores through IP3 or ryanodine receptors, or the influx of extracellular calcium through ion channels at the cell membrane. Depending on the cell type, spatial localization, source of a calcium signal, and the calcium-sensitive target activated, a particular calcium signal can dilate or constrict the arteries. Calcium signals in the vasculature can be classified into several types based on their source, kinetics, and spatial and temporal properties. The calcium signaling mechanisms in smooth muscle and endothelial cells have been extensively studied in the native or freshly isolated cells, therefore, this review is limited to the discussions of studies in native or freshly isolated cells. This article is categorized under: Biological Mechanisms > Cell Signaling Laboratory Methods and Technologies > Imaging Models of Systems Properties and Processes > Mechanistic Models.
Collapse
Affiliation(s)
- Matteo Ottolini
- Robert M. Berne Cardiovascular Research Center, University of Virginia-School of Medicine, Charlottesville, VA, 22908, USA
- Department of Pharmacology, University of Virginia-School of Medicine, Charlottesville, VA, 22908, USA
| | - Kwangseok Hong
- Robert M. Berne Cardiovascular Research Center, University of Virginia-School of Medicine, Charlottesville, VA, 22908, USA
- Department of Physical Education, Chung-Ang University, Seoul, 06974, South Korea
| | - Swapnil K. Sonkusare
- Robert M. Berne Cardiovascular Research Center, University of Virginia-School of Medicine, Charlottesville, VA, 22908, USA
- Department of Pharmacology, University of Virginia-School of Medicine, Charlottesville, VA, 22908, USA
- Department of Molecular Physiology and Biological Physics, University of Virginia-School of Medicine, Charlottesville, VA, 22908, USA
| |
Collapse
|
26
|
Ezeani M. TRP Channels Mediated Pathological Ca 2+-Handling and Spontaneous Ectopy. Front Cardiovasc Med 2019; 6:83. [PMID: 31281820 PMCID: PMC6595228 DOI: 10.3389/fcvm.2019.00083] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2018] [Accepted: 06/04/2019] [Indexed: 01/06/2023] Open
Abstract
Ion channel biology offers great opportunity in identifying and learning about cardiac pathophysiology mechanisms. The discovery of transient receptor potential (TRP) channels is an add-on to the opportunity. Interacting with numerous signaling pathways, being activated multimodally, and having prescribed signatures underlining acute hemodynamic control and cardiac remodeling, TRP channels regulate cardiac pathophysiology. Impaired Ca2+-handling cause contractile abnormality. Modulation of intracellular Ca2+ concentration ([Ca2+]i) is a major part of Ca2+-handling processes in cardiac pathophysiology. TRP channels including TRPM4 regulate [Ca2+]i, Ca2+-handling and cardiac contractility. The channels modulate flux of divalent cations, such as Ca2+ during Ca2+-handling and cardiac contractility. Seminal works implicate TRPM4 and TRPC families in intracellular Ca2+ homeostasis. Defective Ca2+-homeostasis through TRP channels interaction with Ca2+-dependent regulatory proteins such as sodium calcium exchanger (NCX) results in abnormal Ca2+ handling, contractile dysfunction and in spontaneous ectopy. This review provides insight into TRP channels mediated pathological Ca2+-handling and spontaneous ectopy.
Collapse
Affiliation(s)
- Martin Ezeani
- Faculty of Medicine, Nursing and Health Sciences, Alfred Hospital, Monash University, Melbourne, VIC, Australia
| |
Collapse
|
27
|
Falcón D, Galeano-Otero I, Calderón-Sánchez E, Del Toro R, Martín-Bórnez M, Rosado JA, Hmadcha A, Smani T. TRP Channels: Current Perspectives in the Adverse Cardiac Remodeling. Front Physiol 2019; 10:159. [PMID: 30881310 PMCID: PMC6406032 DOI: 10.3389/fphys.2019.00159] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2018] [Accepted: 02/08/2019] [Indexed: 12/22/2022] Open
Abstract
Calcium is an important second messenger required not only for the excitation-contraction coupling of the heart but also critical for the activation of cell signaling pathways involved in the adverse cardiac remodeling and consequently for the heart failure. Sustained neurohumoral activation, pressure-overload, or myocardial injury can cause pathologic hypertrophic growth of the heart followed by interstitial fibrosis. The consequent heart’s structural and molecular adaptation might elevate the risk of developing heart failure and malignant arrhythmia. Compelling evidences have demonstrated that Ca2+ entry through TRP channels might play pivotal roles in cardiac function and pathology. TRP proteins are classified into six subfamilies: TRPC (canonical), TRPV (vanilloid), TRPM (melastatin), TRPA (ankyrin), TRPML (mucolipin), and TRPP (polycystin), which are activated by numerous physical and/or chemical stimuli. TRP channels participate to the handling of the intracellular Ca2+ concentration in cardiac myocytes and are mediators of different cardiovascular alterations. This review provides an overview of the current knowledge of TRP proteins implication in the pathologic process of some frequent cardiac diseases associated with the adverse cardiac remodeling such as cardiac hypertrophy, fibrosis, and conduction alteration.
Collapse
Affiliation(s)
- Debora Falcón
- Department of Medical Physiology and Biophysics, Institute of Biomedicine of Seville, University of Seville, Sevilla, Spain
| | - Isabel Galeano-Otero
- Department of Medical Physiology and Biophysics, Institute of Biomedicine of Seville, University of Seville, Sevilla, Spain
| | - Eva Calderón-Sánchez
- Department of Medical Physiology and Biophysics, Institute of Biomedicine of Seville, University of Seville, Sevilla, Spain.,CIBERCV, Madrid, Spain
| | - Raquel Del Toro
- Department of Medical Physiology and Biophysics, Institute of Biomedicine of Seville, University of Seville, Sevilla, Spain.,CIBERCV, Madrid, Spain
| | - Marta Martín-Bórnez
- Department of Medical Physiology and Biophysics, Institute of Biomedicine of Seville, University of Seville, Sevilla, Spain
| | - Juan A Rosado
- Department of Physiology (Cell Physiology Research Group), University of Extremadura, Cáceres, Spain
| | - Abdelkrim Hmadcha
- Department of Generation and Cell Therapy, Andalusian Center for Molecular Biology and Regenerative Medicine (CABIMER), University of Pablo de Olavide-University of Seville-CSIC, Sevilla, Spain.,CIBERDEM, Madrid, Spain
| | - Tarik Smani
- Department of Medical Physiology and Biophysics, Institute of Biomedicine of Seville, University of Seville, Sevilla, Spain.,CIBERCV, Madrid, Spain
| |
Collapse
|
28
|
Gaur N, Hof T, Haissaguerre M, Vigmond EJ. Propagation Failure by TRPM4 Overexpression. Biophys J 2019; 116:469-476. [PMID: 30598284 DOI: 10.1016/j.bpj.2018.11.3137] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2018] [Revised: 11/22/2018] [Accepted: 11/27/2018] [Indexed: 11/17/2022] Open
Abstract
Transient receptor potential melastatin member 4 (TRPM4) channels are nonselective monovalent cationic channels found in human atria and conduction system. Overexpression of TRPM4 channels has been found in families suffering from inherited cardiac arrhythmias, notably heart block. In this study, we integrate a mathematical formulation of the TRPM4 channel into a Purkinje cell model (Pan-Rudy model). Instead of simply adding the channel to the model, a combination of existing currents equivalent to the TRPM4 current was constructed, based on TRPM4 current dynamics. The equivalent current was then replaced by the TRPM4 current to preserve the model action potential. Single-cell behavior showed early afterdepolarizations for increases in TRPM4 channel expression above twofold. In a homogeneous strand of tissue, propagation conducted faithfully for lower expression levels but failed completely for more than a doubling of TRPM4 channel expression. Only with a heterogeneous distribution of channel expression was intermittent heart block seen. This study suggests that in Purkinje fibers, TRPM4 channels may account for sodium background current (INab), and that a heterogeneous expression of TRPM4 channels in the His/Purkinje system is required for type II heart block, as seen clinically.
Collapse
Affiliation(s)
- Namit Gaur
- University Bordeaux, IMB UMR 5251, Talence, France; IHU Liryc, Electrophysiology and Heart Modeling Institute, Fondation Bordeaux Université, Pessac-Bordeaux, France
| | - Thomas Hof
- IHU Liryc, Electrophysiology and Heart Modeling Institute, Fondation Bordeaux Université, Pessac-Bordeaux, France; Université Bordeaux, Centre de recherche Cardio-Thoracique de Bordeaux, U1045, Bordeaux, France
| | - Michel Haissaguerre
- IHU Liryc, Electrophysiology and Heart Modeling Institute, Fondation Bordeaux Université, Pessac-Bordeaux, France; Bordeaux University Hospital (CHU), Cardiac Electrophysiology and Cardiac Stimulation Team, Pessac, France
| | - Edward J Vigmond
- University Bordeaux, IMB UMR 5251, Talence, France; IHU Liryc, Electrophysiology and Heart Modeling Institute, Fondation Bordeaux Université, Pessac-Bordeaux, France.
| |
Collapse
|
29
|
Azarov JE, Semenov I, Casciola M, Pakhomov AG. Excitation of murine cardiac myocytes by nanosecond pulsed electric field. J Cardiovasc Electrophysiol 2019; 30:392-401. [PMID: 30582656 DOI: 10.1111/jce.13834] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/14/2018] [Revised: 12/18/2018] [Accepted: 12/21/2018] [Indexed: 01/26/2023]
Abstract
INTRODUCTION Opening of voltage-gated sodium channels takes tens to hundreds of microseconds, and mechanisms of their opening by nanosecond pulsed electric field (nsPEF) stimuli remain elusive. This study was aimed at uncovering the mechanisms of how nsPEF elicits action potentials (APs) in cardiomyocytes. METHODS AND RESULTS Fluorescent imaging of optical APs (FluoVolt) and Ca2+ -transients (Fluo-4) was performed in enzymatically isolated murine ventricular cardiomyocytes stimulated by 200-nanosecond trapezoidal pulses. nsPEF stimulation evoked tetrodotoxin-sensitive APs accompanied or preceded by slow sustained depolarization (SSD) and, in most cells, by transient afterdepolarization waves. SSD threshold was lower than the AP threshold (1.26 ± 0.03 vs 1.34 ± 0.03 kV/cm, respectively, P < 0.001). Inhibition of l-type calcium and sodium-calcium exchanger currents reduced the SSD amplitude and increased the AP threshold ( P < 0.05). The threshold for Ca 2+ -transients (1.40 ± 0.04 kV/cm) was not significantly affected by a tetrodotoxin-verapamil cocktail, suggesting the activation of a Ca 2+ entry pathway independent from the opening of Na + or Ca 2+ voltage-gated channels. Removal of external Ca 2+ decreased the SSD amplitude ( P = 0.004) and blocked Ca 2+ -transients but not APs. The incidence of transient afterdepolarization waves was decreased by verapamil and by removal of external Ca 2+ ( P = 0.002). CONCLUSIONS The study established that nsPEF stimulation caused calcium entry into cardiac myocytes (including routes other than voltage-gated calcium channels) and SSD. Tetrodotoxin-sensitive APs were mediated by SSD, whose amplitude depended on the calcium entry. Plasma membrane electroporation was the most likely primary mechanism of SSD with additional contribution from l-type calcium and sodium-calcium exchanger currents.
Collapse
Affiliation(s)
- Jan E Azarov
- Frank Reidy Research Center for Bioelectrics, Old Dominion University, Norfolk, Virginia.,Laboratory of Cardiac Physiology, Institute of Physiology, Komi Science Center, Ural Branch, Russian Academy of Sciences, Syktyvkar, Russia.,Department of Physiology, Medical Institute of Pitirim Sorokin Syktyvkar State University, Syktyvkar, Russia
| | - Iurii Semenov
- Frank Reidy Research Center for Bioelectrics, Old Dominion University, Norfolk, Virginia
| | - Maura Casciola
- Frank Reidy Research Center for Bioelectrics, Old Dominion University, Norfolk, Virginia
| | - Andrei G Pakhomov
- Frank Reidy Research Center for Bioelectrics, Old Dominion University, Norfolk, Virginia
| |
Collapse
|
30
|
Hou JW, Fei YD, Li W, Chen YH, Wang Q, Xiao Y, Wang YP, Li YG. The transient receptor potential melastatin 4 channel inhibitor 9-phenanthrol modulates cardiac sodium channel. Br J Pharmacol 2018; 175:4325-4337. [PMID: 30153324 DOI: 10.1111/bph.14490] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2018] [Revised: 08/06/2018] [Accepted: 08/20/2018] [Indexed: 01/11/2023] Open
Abstract
BACKGROUND AND PURPOSE 9-Phenanthrol, known as a specific inhibitor of the transient receptor potential melastatin 4 (TRMP4) channel, has been shown to modulate cardiac electrical activity and exert antiarrhythmic effects. However, its pharmacological effects remain to be fully explored. Here, we tested the hypothesis that cardiac sodium current inhibition contributes to the cardioprotective effect of 9-phenanthrol. EXPERIMENTAL APPROACH Single ventricular myocytes (VMs) and Purkinje cells (PCs) were enzymatically isolated from rabbits. Arterially perfused rabbit wedge preparations were also used, and transmural electrocardiogram and endocardial action potentials (APs) were simultaneously recorded. Wild-type and mutated human recombinant SCN5A were expressed in HEK293 cells. Anemonia toxin II (ATX-II) was used to amplify the late sodium current (INaL ) and induce arrhythmias. Whole-cell patch clamp technique was used to record APs and ionic currents. KEY RESULTS 9-Phenanthrol (10-50 μM) stabilized ventricular repolarization and abolished arrhythmias induced by ATX-II in both isolated VMs, PCs and wedge preparations. Further study revealed that 9-phenanthrol modulated the gating properties of cardiac sodium channels and dose-dependently inhibited INaL and peak sodium current (INaP ) in VMs with an IC50 of 18 and 71.5 μM respectively. Its ability to inhibit INaL was further confirmed in PCs and HEK293 cells expressing SCN5A mutations. CONCLUSIONS AND IMPLICATIONS Our results indicate that 9-phenanthrol modulates the gating properties of cardiac sodium channels and inhibits INaL and INaP , which may contribute to its antiarrhythmic and cardioprotective effects.
Collapse
Affiliation(s)
- Jian-Wen Hou
- Department of Cardiology, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Yu-Dong Fei
- Department of Cardiology, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Wei Li
- Department of Cardiology, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Yi-He Chen
- Department of Cardiology, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Qian Wang
- Department of Cardiology, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Ying Xiao
- Department of Cardiology, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Yue-Peng Wang
- Department of Cardiology, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Yi-Gang Li
- Department of Cardiology, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| |
Collapse
|
31
|
PTPN6 regulates the cell-surface expression of TRPM4 channels in HEK293 cells. Pflugers Arch 2018; 470:1449-1458. [PMID: 29931651 DOI: 10.1007/s00424-018-2161-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2018] [Revised: 05/11/2018] [Accepted: 05/30/2018] [Indexed: 10/28/2022]
Abstract
Transient receptor-potential, cation channel, subfamily M, member 4 (TRPM4) channels regulate a variety of physiological and pathological processes; however, their roles as functional channels under diverse conditions remain unclear. In this study, cytosolic protein tyrosine phosphatase non-receptor type 6 (PTPN6) interacted with TRPM4 channels. We confirmed their interaction by performing co-immunoprecipitation (Co-IP) assays following heterologous PTPN6 and TRPM4 channel expression in HEK293 cells. Furthermore, biomolecular fluorescence complementation (BiFC) image analysis confirmed TRPM4-PTPN6 binding. In addition, immunoblotting and Co-IP analyses revealed that TRPM4 expression significantly decreased in the membrane fraction of cells after PTPN6 was silenced with a specific short-hairpin RNA (shRNA-PTPN6). In agreement, TRPM4-induced changes in whole-cell currents were not detected in PTPN6-silenced HEK cells, in contrast to cells transfected with a scrambled RNA (scRNA) or in naïve HEK cells. These data suggest that PTPN6 inhibits TRPM4 channel activity by disrupting TRPM4 expression. Furthermore, TRPM4 channels were expressed in the membrane of naïve cells and scRNA transfectants, but not in those of PTPN6-silenced cells. These results indicated that PTPN6 is critically associated with TRPM4 trafficking. This role of PTPN6 in TRPM4 membrane localization was also demonstrated in HeLa cells. TRPM4 overexpression significantly enhanced cell proliferation in untreated HeLa cells, but not in HeLa cells with silenced PTPN6 expression. These findings indicate that PTPN6-dependent TRPM4 expression and trafficking to the plasma membrane is critical for cell proliferation in both HEK293 and HeLa cells. Therefore, PTPN6 is a novel therapeutic target for treating pathologic diseases involving TRPM4.
Collapse
|
32
|
Ozhathil LC, Delalande C, Bianchi B, Nemeth G, Kappel S, Thomet U, Ross‐Kaschitza D, Simonin C, Rubin M, Gertsch J, Lochner M, Peinelt C, Reymond J, Abriel H. Identification of potent and selective small molecule inhibitors of the cation channel TRPM4. Br J Pharmacol 2018; 175:2504-2519. [PMID: 29579323 PMCID: PMC6002741 DOI: 10.1111/bph.14220] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2017] [Revised: 03/08/2018] [Accepted: 03/16/2018] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND AND PURPOSE TRPM4 is a calcium-activated non-selective cation channel expressed in many tissues and implicated in several diseases, and has not yet been validated as a therapeutic target due to the lack of potent and selective inhibitors. We sought to discover a novel series of small-molecule inhibitors by combining in silico methods and cell-based screening assay, with sub-micromolar potency and improved selectivity from previously reported TRPM4 inhibitors. EXPERIMENTAL APPROACH Here, we developed a high throughput screening compatible assay to record TRPM4-mediated Na+ influx in cells using a Na+ -sensitive dye and used this assay to screen a small set of compounds selected by ligand-based virtual screening using previously known weakly active and non-selective TRPM4 inhibitors as seed molecules. Conventional electrophysiological methods were used to validate the potency and selectivity of the hit compounds in HEK293 cells overexpressing TRPM4 and in endogenously expressing prostate cancer cell line LNCaP. Chemical chaperone property of compound 5 was studied using Western blots and electrophysiology experiments. KEY RESULTS A series of halogenated anthranilic amides were identified with TRPM4 inhibitory properties with sub-micromolar potency and adequate selectivity. We also showed for the first time that a naturally occurring variant of TRPM4, which displays loss-of-expression and function, is rescued by the most promising compound 5 identified in this study. CONCLUSIONS AND IMPLICATIONS The discovery of compound 5, a potent and selective inhibitor of TRPM4 with an additional chemical chaperone feature, revealed new opportunities for studying the role of TRPM4 in human diseases and developing clinical drug candidates.
Collapse
Affiliation(s)
- Lijo Cherian Ozhathil
- Institute of Biochemistry and Molecular Medicine, National Center of Competence in Research NCCR TransCureUniversity of BernBernSwitzerland
| | - Clémence Delalande
- Department of Chemistry and Biochemistry, National Center of Competence in Research NCCR TransCureUniversity of BernBernSwitzerland
| | - Beatrice Bianchi
- Institute of Biochemistry and Molecular Medicine, National Center of Competence in Research NCCR TransCureUniversity of BernBernSwitzerland
| | - Gabor Nemeth
- Department of Chemistry and Biochemistry, National Center of Competence in Research NCCR TransCureUniversity of BernBernSwitzerland
| | - Sven Kappel
- Institute of Biochemistry and Molecular Medicine, National Center of Competence in Research NCCR TransCureUniversity of BernBernSwitzerland
| | - Urs Thomet
- Institute of Biochemistry and Molecular Medicine, National Center of Competence in Research NCCR TransCureUniversity of BernBernSwitzerland
| | - Daniela Ross‐Kaschitza
- Institute of Biochemistry and Molecular Medicine, National Center of Competence in Research NCCR TransCureUniversity of BernBernSwitzerland
| | - Céline Simonin
- Department of Chemistry and Biochemistry, National Center of Competence in Research NCCR TransCureUniversity of BernBernSwitzerland
| | - Matthias Rubin
- Institute of Biochemistry and Molecular Medicine, National Center of Competence in Research NCCR TransCureUniversity of BernBernSwitzerland
| | - Jürg Gertsch
- Institute of Biochemistry and Molecular Medicine, National Center of Competence in Research NCCR TransCureUniversity of BernBernSwitzerland
| | - Martin Lochner
- Institute of Biochemistry and Molecular Medicine, National Center of Competence in Research NCCR TransCureUniversity of BernBernSwitzerland
- Department of Chemistry and Biochemistry, National Center of Competence in Research NCCR TransCureUniversity of BernBernSwitzerland
| | - Christine Peinelt
- Institute of Biochemistry and Molecular Medicine, National Center of Competence in Research NCCR TransCureUniversity of BernBernSwitzerland
| | - Jean‐Louis Reymond
- Department of Chemistry and Biochemistry, National Center of Competence in Research NCCR TransCureUniversity of BernBernSwitzerland
| | - Hugues Abriel
- Institute of Biochemistry and Molecular Medicine, National Center of Competence in Research NCCR TransCureUniversity of BernBernSwitzerland
| |
Collapse
|
33
|
Veress R, Baranyai D, Hegyi B, Kistamás K, Dienes C, Magyar J, Bányász T, Nánási PP, Szentandrássy N, Horváth B. Transient receptor potential melastatin 4 channel inhibitor 9-phenanthrol inhibits K + but not Ca 2+ currents in canine ventricular myocytes. Can J Physiol Pharmacol 2018; 96:1022-1029. [PMID: 29806985 DOI: 10.1139/cjpp-2018-0049] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The role of transient receptor potential melastatin 4 (TRPM4) channels has been frequently tested using their inhibitor 9-phenanthrol in various cardiac preparations; however, the selectivity of the compound is uncertain. Therefore, in the present study, the concentration-dependent effects of 9-phenanthrol on major ionic currents were studied in canine isolated ventricular cells using whole-cell configuration of the patch-clamp technique and 10 mM BAPTA-containing pipette solution to prevent the Ca2+-dependent activation of TRPM4 channels. Transient outward (Ito1), rapid delayed rectifier (IKr), and inward rectifier (IK1) K+ currents were suppressed by 10 and 30 μM 9-phenanthrol with the blocking potency for IK1 < IKr < Ito1 and partial reversibility. L-type Ca2+ current was not affected up to the concentration of 30 μM. In addition, a steady outward current was detected at voltages positive to -40 mV in 9-phenanthrol, which was larger at more positive voltages and larger 9-phenanthrol concentrations. Action potentials were recorded using microelectrodes. Maximal rate of depolarization, phase-1 repolarization, and terminal repolarization were decreased and the plateau potential was depressed by 9-phenanthrol (3-30 μM), congruently with the observed alterations of ionic currents. Significant action potential prolongation was observed by 9-phenanthrol in the majority of the studied cells, but only at 30 μM concentration. In conclusion, 9-phenanthrol is not selective to TRPM4 channels in canine ventricular myocardium; therefore, its application as a TRPM4 blocker can be appropriate only in expression systems but not in native cardiac cells.
Collapse
Affiliation(s)
- Roland Veress
- a Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Dóra Baranyai
- a Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Bence Hegyi
- b Department of Pharmacology, University of California at Davis, Davis, CA 95616, USA
| | - Kornél Kistamás
- a Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Csaba Dienes
- a Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - János Magyar
- a Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary.,c Division of Sport Physiology, Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Tamás Bányász
- a Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Péter P Nánási
- a Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary.,d Department of Dental Physiology and Pharmacology, Faculty of Dentistry, University of Debrecen, Debrecen, Hungary
| | - Norbert Szentandrássy
- a Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary.,d Department of Dental Physiology and Pharmacology, Faculty of Dentistry, University of Debrecen, Debrecen, Hungary
| | - Balázs Horváth
- a Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary.,e Faculty of Pharmacy, University of Debrecen, Debrecen, Hungary
| |
Collapse
|
34
|
Hu Y, Duan Y, Takeuchi A, Hai-Kurahara L, Ichikawa J, Hiraishi K, Numata T, Ohara H, Iribe G, Nakaya M, Mori MX, Matsuoka S, Ma G, Inoue R. Uncovering the arrhythmogenic potential of TRPM4 activation in atrial-derived HL-1 cells using novel recording and numerical approaches. Cardiovasc Res 2018; 113:1243-1255. [PMID: 28898995 DOI: 10.1093/cvr/cvx117] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/02/2017] [Accepted: 06/13/2017] [Indexed: 12/20/2022] Open
Abstract
Aims Transient receptor potential cation channel subfamily melastatin member 4 (TRPM4), a Ca2+-activated nonselective cation channel abundantly expressed in the heart, has been implicated in conduction block and other arrhythmic propensities associated with cardiac remodelling and injury. The present study aimed to quantitatively evaluate the arrhythmogenic potential of TRPM4. Methods and results Patch clamp and biochemical analyses were performed using expression system and an immortalized atrial cardiomyocyte cell line (HL-1), and numerical model simulation was employed. After rapid desensitization, robust reactivation of TRPM4 channels required high micromolar concentrations of Ca2+. However, upon evaluation with a newly devised, ionomycin-permeabilized cell-attached (Iono-C/A) recording technique, submicromolar concentrations of Ca2+ (apparent Kd = ∼500 nM) were enough to activate this channel. Similar submicromolar Ca2+ dependency was also observed with sharp electrode whole-cell recording and in experiments coexpressing TRPM4 and L-type voltage-dependent Ca2+ channels. Numerical simulations using a number of action potential (AP) models (HL-1, Nygren, Luo-Rudy) incorporating the Ca2+- and voltage-dependent gating parameters of TRPM4, as assessed by Iono-C/A recording, indicated that a few-fold increase in TRPM4 activity is sufficient to delay late AP repolarization and further increases (≥ six-fold) evoke early afterdepolarization. These model predictions are consistent with electrophysiological data from angiotensin II-treated HL-1 cells in which TRPM4 expression and activity were enhanced. Conclusions These results collectively indicate that the TRPM4 channel is activated by a physiological range of Ca2+ concentrations and its excessive activity can cause arrhythmic changes. Moreover, these results demonstrate potential utility of the first AP models incorporating TRPM4 gating for in silico assessment of arrhythmogenicity in remodelling cardiac tissue.
Collapse
Affiliation(s)
- Yaopeng Hu
- Department of Physiology, Fukuoka University School of Medicine, 7-45-1 Nanakuma, Jonan-ku, Fukuoka 814-0180, Japan.,Department of Cardiology, Zhongda Hospital, Southeast University, Nanjing, Jiangsu 210009, China
| | - Yubin Duan
- Department of Physiology, Fukuoka University School of Medicine, 7-45-1 Nanakuma, Jonan-ku, Fukuoka 814-0180, Japan
| | - Ayako Takeuchi
- Department of Integrative and Systems Physiology, Faculty of Medical Sciences, University of Fukui, Yoshida-gun, Fukui 910-1193, Japan
| | - Lin Hai-Kurahara
- Department of Physiology, Fukuoka University School of Medicine, 7-45-1 Nanakuma, Jonan-ku, Fukuoka 814-0180, Japan
| | - Jun Ichikawa
- Department of Physiology, Fukuoka University School of Medicine, 7-45-1 Nanakuma, Jonan-ku, Fukuoka 814-0180, Japan
| | - Keizo Hiraishi
- Department of Physiology, Fukuoka University School of Medicine, 7-45-1 Nanakuma, Jonan-ku, Fukuoka 814-0180, Japan
| | - Tomohiro Numata
- Department of Physiology, Fukuoka University School of Medicine, 7-45-1 Nanakuma, Jonan-ku, Fukuoka 814-0180, Japan
| | - Hiroki Ohara
- Department of Pharmacology and Toxicology, Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka 812-8582, Japan
| | - Gentaro Iribe
- Department of Cardiovascular Physiology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Kita-ku, Okayama 700-8558, Japan
| | - Michio Nakaya
- Department of Pharmacology and Toxicology, Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka 812-8582, Japan
| | - Masayuki X Mori
- Department of Physiology, Fukuoka University School of Medicine, 7-45-1 Nanakuma, Jonan-ku, Fukuoka 814-0180, Japan.,Department of Synthetic Chemistry and Biological Chemistry, School of Engineering, Kyoto University, Kyoto, Japan
| | - Satoshi Matsuoka
- Department of Integrative and Systems Physiology, Faculty of Medical Sciences, University of Fukui, Yoshida-gun, Fukui 910-1193, Japan
| | - Genshan Ma
- Department of Cardiology, Zhongda Hospital, Southeast University, Nanjing, Jiangsu 210009, China
| | - Ryuji Inoue
- Department of Physiology, Fukuoka University School of Medicine, 7-45-1 Nanakuma, Jonan-ku, Fukuoka 814-0180, Japan
| |
Collapse
|
35
|
Bianchi B, Ozhathil LC, Medeiros-Domingo A, Gollob MH, Abriel H. Four TRPM4 Cation Channel Mutations Found in Cardiac Conduction Diseases Lead to Altered Protein Stability. Front Physiol 2018; 9:177. [PMID: 29568272 PMCID: PMC5852105 DOI: 10.3389/fphys.2018.00177] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2017] [Accepted: 02/20/2018] [Indexed: 12/20/2022] Open
Abstract
Transient receptor potential melastatin member 4 (TRPM4), a non-selective cation channel, mediates cell membrane depolarization in immune response, insulin secretion, neurological disorders, and cancer. Pathological variants in TRPM4 gene have been linked to several cardiac phenotypes such as complete heart block (CHB), ventricular tachycardia, and Brugada syndrome (BrS). Despite recent findings regarding the functional implications of TRPM4 in cardiac diseases, the molecular and cellular mechanisms leading to altered conduction are poorly understood. In the present study, we identify and characterize four novel TRPM4 variants found in patients with CHB or ventricular fibrillation. Three of them, p.A101T, p.S1044C and a double variant p.A101T/P1204L, led to a decreased expression and function of the channel. On the contrary, the variant p.Q854R showed an increase in TRPM4 current. Recent evidence indicates that altered degradation rate of mutant proteins represents a pathogenic mechanism underlying genetic diseases. In consequence, protein turnover of WT-TRPM4 and TRPM4 variants overexpressed in HEK293 cells was analyzed using cycloheximide, an inhibitor of protein biosynthesis. Upon addition of cycloheximide, WT-TRPM4 decayed with a half-life of ~20 h, while loss-of-expression variants showed a ~30% increase in degradation rate, with a half-life close to 12 h. Together, the gain-of-expression variant showed a higher stability and a doubled half-life compared to WT-TRPM4. In conclusion, decreased or increased protein expression of several TRPM4 variants linked to cardiac conduction disorders or ventricular arrhythmias were found to be caused by altered TRPM4 half-life compared to the WT form.
Collapse
Affiliation(s)
- Beatrice Bianchi
- Swiss National Centre of Competence in Research (NCCR) TransCure, Institute of Biochemistry and Molecular Medicine, University of Bern, Bern, Switzerland
| | - Lijo Cherian Ozhathil
- Swiss National Centre of Competence in Research (NCCR) TransCure, Institute of Biochemistry and Molecular Medicine, University of Bern, Bern, Switzerland
| | | | - Michael H Gollob
- Department of Medicine, Peter Munk Cardiac Centre, Toronto General Hospital, University of Toronto, Toronto, ON, Canada
| | - Hugues Abriel
- Swiss National Centre of Competence in Research (NCCR) TransCure, Institute of Biochemistry and Molecular Medicine, University of Bern, Bern, Switzerland
| |
Collapse
|
36
|
Leiva-Salcedo E, Riquelme D, Cerda O, Stutzin A. TRPM4 activation by chemically- and oxygen deprivation-induced ischemia and reperfusion triggers neuronal death. Channels (Austin) 2017; 11:624-635. [PMID: 28876976 DOI: 10.1080/19336950.2017.1375072] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Cerebral ischemia-reperfusion injury triggers a deleterious process ending in neuronal death. This process has two components, a glutamate-dependent and a glutamate-independent mechanism. In the glutamate-independent mechanism, neurons undergo a slow depolarization eventually leading to neuronal death. However, little is known about the molecules that take part in this process. Here we show by using mice cortical neurons in culture and ischemia-reperfusion protocols that TRPM4 is fundamental for the glutamate-independent neuronal damage. Thus, by blocking excitotoxicity, we reveal a slow activating, glibenclamide- and 9-phenanthrol-sensitive current, which is activated within 5 min upon ischemia-reperfusion onset. TRPM4 shRNA-based silenced neurons show a reduced ischemia-reperfusion induced current and depolarization. Neurons were protected from neuronal death up to 3 hours after the ischemia-reperfusion challenge. The activation of TRPM4 during ischemia-reperfusion injury involves the increase in both, intracellular calcium and H2O2, which may act together to produce a sustained activation of the channel.
Collapse
Affiliation(s)
- Elías Leiva-Salcedo
- a Departamento de Biología , Facultad de Química y Biología, Universidad de Santiago de Chile , Santiago , Chile
| | - Denise Riquelme
- a Departamento de Biología , Facultad de Química y Biología, Universidad de Santiago de Chile , Santiago , Chile
| | - Oscar Cerda
- b Programa de Biología Celular y Molecular , Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile , Santiago , Chile.,c Millennium Nucleus of Ion Channels-Associated Diseases (MiNICAD) , Universidad de Chile , Santiago , Chile
| | - Andrés Stutzin
- d Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile , Santiago , Chile
| |
Collapse
|
37
|
Kim JC, Son MJ, Wang J, Woo SH. Regulation of cardiac Ca 2+ and ion channels by shear mechanotransduction. Arch Pharm Res 2017; 40:783-795. [PMID: 28702845 DOI: 10.1007/s12272-017-0929-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2017] [Accepted: 07/06/2017] [Indexed: 11/25/2022]
Abstract
Cardiac contraction is controlled by a Ca2+ signaling sequence that includes L-type Ca2+ current-gated opening of Ca2+ release channels (ryanodine receptors) in the sarcoplasmic reticulum (SR). Local Ca2+ signaling in the atrium differs from that in the ventricle because atrial myocytes lack transverse tubules and have more abundant corbular SR. Myocardium is subjected to a variety of forces with each contraction, such as stretch, shear stress, and afterload, and adapts to those mechanical stresses. These mechanical stimuli increase in heart failure, hypertension, and valvular heart diseases that are clinically implicated in atrial fibrillation and stroke. In the present review, we describe distinct responses of atrial and ventricular myocytes to shear stress and compare them with other mechanical responses in the context of local and global Ca2+ signaling and ion channel regulation. Recent evidence suggests that shear mechanotransduction in cardiac myocytes involves activation of gap junction hemichannels, purinergic signaling, and generation of mitochondrial reactive oxygen species. Significant alterations in Ca2+ signaling and ionic currents by shear stress may be implicated in the pathogenesis of cardiac arrhythmia and failure.
Collapse
Affiliation(s)
- Joon-Chul Kim
- College of Pharmacy, Chungnam National University, 99 Daehak-ro, Yuseong-gu, Daejeon, 305-764, South Korea
| | - Min-Jeong Son
- College of Pharmacy, Chungnam National University, 99 Daehak-ro, Yuseong-gu, Daejeon, 305-764, South Korea
| | - Jun Wang
- College of Pharmacy, Chungnam National University, 99 Daehak-ro, Yuseong-gu, Daejeon, 305-764, South Korea
| | - Sun-Hee Woo
- College of Pharmacy, Chungnam National University, 99 Daehak-ro, Yuseong-gu, Daejeon, 305-764, South Korea.
| |
Collapse
|
38
|
Angstadt JD, Giordano JR, Goncalves AJ. 9-Phenanthrol modulates postinhibitory rebound and afterhyperpolarizing potentials in an excitatory motor neuron of the medicinal leech. J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2017; 203:613-633. [DOI: 10.1007/s00359-017-1178-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2017] [Revised: 05/01/2017] [Accepted: 05/02/2017] [Indexed: 12/19/2022]
|
39
|
Lemoine S, Blanchart K, Souplis M, Lemaitre A, Legallois D, Coulbault L, Simard C, Allouche S, Abraini JH, Hanouz JL, Rouet R, Sallé L, Guinamard R, Manrique A. Argon Exposure Induces Postconditioning in Myocardial Ischemia-Reperfusion. J Cardiovasc Pharmacol Ther 2017; 22:564-573. [PMID: 28381122 DOI: 10.1177/1074248417702891] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
BACKGROUND AND PURPOSE Cardioprotection against ischemia-reperfusion (I/R) damages remains a major concern during prehospital management of acute myocardial infarction. Noble gases have shown beneficial effects in preconditioning studies. Because emergency proceedings in the context of myocardial infarction require postconditioning strategies, we evaluated the effects of argon in such protocols on mammalian cardiac tissue. EXPERIMENTAL APPROACHES In rat, cardiac I/R was induced in vivo by transient coronary artery ligature and cardiac functions were evaluated by magnetic resonance imaging. Hypoxia-reoxygenation (H/R)-induced arrhythmias were evaluated in vitro using intracellular microelectrodes on both rat-isolated ventricle and a model of border zone in guinea pig ventricle. Hypoxia-reoxygenation loss of contractile force was assessed in human atrial appendages. In those models, postconditioning was induced by 5 minutes application of argon at the time of reperfusion. KEY RESULTS In the in vivo model, I/R produced left ventricular ejection fraction decrease (24%) and wall motion score increase (36%) which was prevented when argon was applied in postconditioning. In vitro, argon postconditioning abolished H/R-induced arrhythmias such as early after depolarizations, conduction blocks, and reentries. Recovery of contractile force in human atrial appendages after H/R was enhanced in the argon group, increasing from 51% ± 2% in the nonconditioned group to 83% ± 7% in the argon-treated group ( P < .001). This effect of argon was abolished in the presence of wortmannin and PD98059 which inhibit prosurvival phosphatidylinositol-3-kinase (PI3K)/protein kinase B (Akt) and MEK/extracellular receptor kinase 1/2 (ERK 1/2), respectively, or in the presence of the mitochondrial permeability transition pore opener atractyloside, suggesting the involvement of the reperfusion injury salvage kinase pathway. CONCLUSION AND IMPLICATIONS Argon has strong cardioprotective properties when applied in conditions of postconditioning and thus appears as a potential therapeutic tool in I/R situations.
Collapse
Affiliation(s)
- Sandrine Lemoine
- 1 Signalisation, Electrophysiologie et Imagerie des lésions d'ischémie-reperfusion myocardique, Normandie Univ, UNICAEN, Caen, France
| | - Katrien Blanchart
- 1 Signalisation, Electrophysiologie et Imagerie des lésions d'ischémie-reperfusion myocardique, Normandie Univ, UNICAEN, Caen, France
| | - Mathieu Souplis
- 1 Signalisation, Electrophysiologie et Imagerie des lésions d'ischémie-reperfusion myocardique, Normandie Univ, UNICAEN, Caen, France
| | - Adrien Lemaitre
- 1 Signalisation, Electrophysiologie et Imagerie des lésions d'ischémie-reperfusion myocardique, Normandie Univ, UNICAEN, Caen, France
| | - Damien Legallois
- 1 Signalisation, Electrophysiologie et Imagerie des lésions d'ischémie-reperfusion myocardique, Normandie Univ, UNICAEN, Caen, France
| | - Laurent Coulbault
- 1 Signalisation, Electrophysiologie et Imagerie des lésions d'ischémie-reperfusion myocardique, Normandie Univ, UNICAEN, Caen, France
| | - Christophe Simard
- 1 Signalisation, Electrophysiologie et Imagerie des lésions d'ischémie-reperfusion myocardique, Normandie Univ, UNICAEN, Caen, France
| | - Stéphane Allouche
- 1 Signalisation, Electrophysiologie et Imagerie des lésions d'ischémie-reperfusion myocardique, Normandie Univ, UNICAEN, Caen, France
| | - Jacques H Abraini
- 1 Signalisation, Electrophysiologie et Imagerie des lésions d'ischémie-reperfusion myocardique, Normandie Univ, UNICAEN, Caen, France
| | - Jean-Luc Hanouz
- 1 Signalisation, Electrophysiologie et Imagerie des lésions d'ischémie-reperfusion myocardique, Normandie Univ, UNICAEN, Caen, France
| | - René Rouet
- 1 Signalisation, Electrophysiologie et Imagerie des lésions d'ischémie-reperfusion myocardique, Normandie Univ, UNICAEN, Caen, France
| | - Laurent Sallé
- 1 Signalisation, Electrophysiologie et Imagerie des lésions d'ischémie-reperfusion myocardique, Normandie Univ, UNICAEN, Caen, France
| | - Romain Guinamard
- 1 Signalisation, Electrophysiologie et Imagerie des lésions d'ischémie-reperfusion myocardique, Normandie Univ, UNICAEN, Caen, France
| | - Alain Manrique
- 1 Signalisation, Electrophysiologie et Imagerie des lésions d'ischémie-reperfusion myocardique, Normandie Univ, UNICAEN, Caen, France
| |
Collapse
|
40
|
Inhibition of rapid delayed rectifier potassium current (I Kr) by ischemia/reperfusion and its recovery by vitamin E in ventricular myocytes. J Electrocardiol 2017. [PMID: 28646979 DOI: 10.1016/j.jelectrocard.2017.03.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Ischemia/reperfusion (I/R) induces prolongation of QT interval and action potential duration (APD), which is a major cardiac electrical disorder in patients with arrhythmias. However, the mechanism of QT interval prolongation induced by I/R remains unclear. In the present study, we hypothesized that the rapid component of delayed rectifier potassium (IKr) channel plays an important role in I/R-induced QT interval prolongation. We observed a marked attenuation of IKr and a significant prolongation of action potential duration (APD) in a simulated I/R system with sodium dithionite (Na2S2O4) in ventricular myocytes of guinea pigs. The IKr current density was inhibited by 64% and APD increased by 87% respectively. Moreover, the inhibition of IKr is primarily ascribed to overproduction of reactive oxygen species (ROS) by I/R, which can be partly reversed by antioxidant vitamin E (100μmol/L). The value of IKr tail current density increased from 0.516±0.040 pA/pF in I/R to 0.939±0.091 pA/pF when treated with vitamin E. Moreover, we also demonstrated that QTc interval was increased by I/R and reversed by Vitamin E in isolated guinea pig hearts. In conclusion, the inhibition of IKr is one of the underlying mechanisms of prolongation of QT interval and APD in I/R. Vitamin E might have a benefit in coronary reperfusion therapy.
Collapse
|
41
|
The TRPM4 channel is functionally important for the beneficial cardiac remodeling induced by endurance training. J Muscle Res Cell Motil 2017; 38:3-16. [DOI: 10.1007/s10974-017-9466-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2016] [Accepted: 02/02/2017] [Indexed: 10/20/2022]
|
42
|
Ma Z, Björklund A, Islam MS. A TRPM4 Inhibitor 9-Phenanthrol Inhibits Glucose- and Glucagon-Like Peptide 1-Induced Insulin Secretion from Rat Islets of Langerhans. J Diabetes Res 2017; 2017:5131785. [PMID: 29098165 PMCID: PMC5643033 DOI: 10.1155/2017/5131785] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/26/2017] [Revised: 08/18/2017] [Accepted: 09/10/2017] [Indexed: 11/29/2022] Open
Abstract
Pancreatic β-cells express several ion channels of the transient receptor potential family, which play important roles in mediating the stimulus-secretion coupling. One of these channels, the TRPM4 is a Ca2+-activated monovalent cation channel. This channel is inhibited by 9-phenanthrol, which also inhibits the TMEM16a Cl- channel, and activates the Ca2+-activated K+ channel, Kca3.1. The net effects of ion-channel modulation by 9-phenantherol on the insulin secretion remain unclear. We tested the effects of 9-phenanthrol on glucose- and GLP-1-induced insulin secretion from isolated rat islets in static incubations. When applied to the islets in the presence of 3.3 mM glucose, 9-phenanthrol caused a small increase in insulin secretion (~7% of the insulin secretion stimulated by 10 mM glucose). 10 μM 9-phenanthrol did not inhibit glucose- or GLP-1-induced insulin secretion. 20 μM and 30 μM 9-phenanthrol inhibited glucose-induced insulin secretion by ~80% and ~85%, respectively. Inhibition of the GLP-1-induced insulin secretion by 20 μM and 30 μM 9-phenanthrol was 65% and 94%, respectively. Our study shows that the major effect of 9-phenanthrol on the islets is a strong inhibition of insulin secretion, and we speculate that compounds related to 9-phenanthrol may be potentially useful in treating the pancreatogenous hyperinsulinemic hypoglycemia syndromes.
Collapse
Affiliation(s)
- Zuheng Ma
- Department of Molecular Medicine and Surgery, Karolinska Institutet, Karolinska University Hospital, 171 76 Stockholm, Sweden
| | - Anneli Björklund
- Department of Molecular Medicine and Surgery, Karolinska Institutet, Karolinska University Hospital, 171 76 Stockholm, Sweden
| | - Md. Shahidul Islam
- Department of Clinical Science and Education, Södersjukhuset, Karolinska Institutet, Research Center, 3rd Floor, 118 83 Stockholm, Sweden
- Department of Emergency Care and Internal Medicine, Uppsala University Hospital, Uppsala University, Uppsala, Sweden
| |
Collapse
|
43
|
Son MJ, Kim JC, Kim SW, Chidipi B, Muniyandi J, Singh TD, So I, Subedi KP, Woo SH. Shear stress activates monovalent cation channel transient receptor potential melastatin subfamily 4 in rat atrial myocytes via type 2 inositol 1,4,5-trisphosphate receptors and Ca(2+) release. J Physiol 2016; 594:2985-3004. [PMID: 26751048 DOI: 10.1113/jp270887] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2015] [Accepted: 01/06/2016] [Indexed: 12/22/2022] Open
Abstract
KEY POINTS During each contraction and haemodynamic disturbance, cardiac myocytes are subjected to fluid shear stress as a result of blood flow and the relative movement of sheets of myocytes. The present study aimed to characterize the shear stress-sensitive membrane current in atrial myocytes using the whole-cell patch clamp technique, combined with pressurized fluid flow, as well as pharmacological and genetic interventions of specific proteins. The data obtained suggest that shear stress indirectly activates the monovalent cation current carried by transient receptor potential melastatin subfamily 4 channels via type 2 inositol 1,4,5-trisphosphate receptor-mediated Ca(2+) release in subsarcolemmal domains of atrial myocytes. Ca(2+) -mediated interactions between these two proteins under shear stress may be an important mechanism by which atrial cells measure mechanical stress and translate it to alter their excitability. ABSTRACT Atrial myocytes are subjected to shear stress during the cardiac cycle under physiological or pathological conditions. The ionic currents regulated by shear stress remain poorly understood. We report the characteristics, molecular identity and activation mechanism of the shear stress-sensitive current (Ishear ) in rat atrial myocytes. A shear stress of ∼16 dyn cm(-2) was applied to single myocytes using a pressurized microflow system, and the current was measured by whole-cell patch clamp. In symmetrical CsCl solutions with minimal concentrations of internal EGTA, Ishear showed an outwardly rectifying current-voltage relationship (reversal at -2 mV). The current was conducted primarily (∼80%) by monovalent cations but not Ca(2+) . It was suppressed by intracellular Ca(2+) buffering at a fixed physiological level, inhibitors of transient receptor potential melastatin subfamily 4 (TRPM4), intracellular introduction of TRPM4 antibodies or knockdown of TRPM4 expression, suggesting that TRPM4 carries most of this current. A notable reduction in Ishear occurred upon inhibition of Ca(2+) release through the ryanodine receptors or inositol 1,4,5-trisphosphate receptors (IP3 R) and upon depletion of sarcoplasmic reticulum Ca(2+) . In type 2 IP3 R (IP3 R2) knockout atrial myocytes, Ishear was 10-20% of that in wild-type myocytes. Immunocytochemistry and proximity ligation assays revealed that TRPM4 and IP3 R2 were expressed at peripheral sites with co-localization, although they are not localized within 40 nm. Peripheral localization of TRPM4 was intact in IP3 R2 knockout cells. The data obtained in the present study suggest that shear stress activates TRPM4 current by triggering Ca(2+) release from the IP3 R2 in the peripheral domains of atrial myocytes.
Collapse
Affiliation(s)
- Min-Jeong Son
- Laboratory of Physiology, College of Pharmacy, Chungnam National University, Yuseong-gu, Daejeon, South Korea
| | - Joon-Chul Kim
- Laboratory of Physiology, College of Pharmacy, Chungnam National University, Yuseong-gu, Daejeon, South Korea
| | - Sung Woo Kim
- Laboratory of Physiology, College of Pharmacy, Chungnam National University, Yuseong-gu, Daejeon, South Korea
| | - Bojjibabu Chidipi
- Laboratory of Physiology, College of Pharmacy, Chungnam National University, Yuseong-gu, Daejeon, South Korea
| | - Jeyaraj Muniyandi
- Laboratory of Physiology, College of Pharmacy, Chungnam National University, Yuseong-gu, Daejeon, South Korea
| | - Thoudam Debraj Singh
- Laboratory of Physiology, College of Pharmacy, Chungnam National University, Yuseong-gu, Daejeon, South Korea
| | - Insuk So
- Department of Physiology, College of Medicine, Seoul National University, Seoul, South Korea
| | - Krishna P Subedi
- Laboratory of Physiology, College of Pharmacy, Chungnam National University, Yuseong-gu, Daejeon, South Korea.,Secretory Physiology Section, Molecular Physiology and Therapeutics Branch, National Institute of Dental and Craniofacial Research, NIH, Bethesda, MD, USA
| | - Sun-Hee Woo
- Laboratory of Physiology, College of Pharmacy, Chungnam National University, Yuseong-gu, Daejeon, South Korea
| |
Collapse
|
44
|
Hof T, Sallé L, Coulbault L, Richer R, Alexandre J, Rouet R, Manrique A, Guinamard R. TRPM4 non-selective cation channels influence action potentials in rabbit Purkinje fibres. J Physiol 2015; 594:295-306. [PMID: 26548780 DOI: 10.1113/jp271347] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2015] [Accepted: 10/29/2015] [Indexed: 11/08/2022] Open
Abstract
KEY POINTS The transient receptor potential melastatin 4 (TRPM4) inhibitor 9-phenanthrol reduces action potential duration in rabbit Purkinje fibres but not in ventricle. TRPM4-like single channel activity is observed in isolated rabbit Purkinje cells but not in ventricular cells. The TRPM4-like current develops during the notch and early repolarization phases of the action potential in Purkinje cells. ABSTRACT Transient receptor potential melastatin 4 (TRPM4) Ca(2+)-activated non-selective cation channel activity has been recorded in cardiomyocytes and sinus node cells from mammals. In addition, TRPM4 gene mutations are associated with human diseases of cardiac conduction, suggesting that TRPM4 plays a role in this aspect of cardiac function. Here we evaluate the TRPM4 contribution to cardiac electrophysiology of Purkinje fibres. Ventricular strips with Purkinje fibres were isolated from rabbit hearts. Intracellular microelectrodes recorded Purkinje fibre activity and the TRPM4 inhibitor 9-phenanthrol was applied to unmask potential TRPM4 contributions to the action potential. 9-Phenanthrol reduced action potential duration measured at the point of 50 and 90% repolarization with an EC50 of 32.8 and 36.1×10(-6) mol l(-1), respectively, but did not modulate ventricular action potentials. Inside-out patch-clamp recordings were used to monitor TRPM4 activity in isolated Purkinje cells. TRPM4-like single channel activity (conductance = 23.8 pS; equal permeability for Na(+) and K(+); sensitivity to voltage, Ca(2+) and 9-phenanthrol) was observed in 43% of patches from Purkinje cells but not from ventricular cells (0/16). Action potential clamp experiments performed in the whole-cell configuration revealed a transient inward 9-phenanthrol-sensitive current (peak density = -0.65 ± 0.15 pA pF(-1); n = 5) during the plateau phases of the Purkinje fibre action potential. These results show that TRPM4 influences action potential characteristics in rabbit Purkinje fibres and thus could modulate cardiac conduction and be involved in triggering arrhythmias.
Collapse
Affiliation(s)
- Thomas Hof
- Groupe Signalisation, Electrophysiologie et Imagerie des Lésions d'Ischémie-Reperfusion Myocardique, Unicaen, Normandie Université, EA 4650, Caen, France
| | - Laurent Sallé
- Groupe Signalisation, Electrophysiologie et Imagerie des Lésions d'Ischémie-Reperfusion Myocardique, Unicaen, Normandie Université, EA 4650, Caen, France
| | - Laurent Coulbault
- Groupe Signalisation, Electrophysiologie et Imagerie des Lésions d'Ischémie-Reperfusion Myocardique, Unicaen, Normandie Université, EA 4650, Caen, France
| | - Romain Richer
- Groupe Signalisation, Electrophysiologie et Imagerie des Lésions d'Ischémie-Reperfusion Myocardique, Unicaen, Normandie Université, EA 4650, Caen, France
| | - Joachim Alexandre
- Groupe Signalisation, Electrophysiologie et Imagerie des Lésions d'Ischémie-Reperfusion Myocardique, Unicaen, Normandie Université, EA 4650, Caen, France
| | - René Rouet
- Groupe Signalisation, Electrophysiologie et Imagerie des Lésions d'Ischémie-Reperfusion Myocardique, Unicaen, Normandie Université, EA 4650, Caen, France
| | - Alain Manrique
- Groupe Signalisation, Electrophysiologie et Imagerie des Lésions d'Ischémie-Reperfusion Myocardique, Unicaen, Normandie Université, EA 4650, Caen, France
| | - Romain Guinamard
- Groupe Signalisation, Electrophysiologie et Imagerie des Lésions d'Ischémie-Reperfusion Myocardique, Unicaen, Normandie Université, EA 4650, Caen, France
| |
Collapse
|
45
|
Miller BA, Cheung JY. TRPM2 protects against tissue damage following oxidative stress and ischaemia-reperfusion. J Physiol 2015; 594:4181-91. [PMID: 26420388 DOI: 10.1113/jp270934] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2015] [Accepted: 09/13/2015] [Indexed: 12/17/2022] Open
Abstract
TRPM channels are a subgroup of the transient receptor potential (TRP) channel superfamily whose members have important roles in cell proliferation and survival. TRPM2, the second subfamily member to be cloned, is expressed in many tissues including brain, heart, vasculature and haematopoietic cells. TRPM2 is activated by oxidative stress and several other extracellular signals including tumour necrosis factor α (TNF-α) and amyloid β-peptide, which increase production of ADP-ribose (ADPR). ADPR binds to the TRPM2 C-terminal NUDT9-H domain, activating the channel. Early studies support the paradigm that TRPM2 activation induces cell death by sustained Ca(2+) influx or by enhancing cytokine production, aggravating inflammation and tissue injury. However, more recent data show that for a number of physiological processes, TRPM2 is protective. TRPM2 protects lungs from endotoxin-induced injury by reducing reactive oxygen species (ROS) production by phagocytes. It protects hearts from oxidative damage after ischaemia-reperfusion or hypoxia-reoxygenation by maintaining better mitochondrial bioenergetics and by decreasing ROS. Sustained Ca(2+) entry through TRPM2 is required to maintain cellular bioenergetics and protect against hypoxia-reoxygenation injury. TRPM2 also protects neuroblastoma from moderate oxidative stress by decreasing ROS through increased levels of forkhead box transcription factor 3a (FOXO3a) and a downstream effector, superoxide dismutase 2. TRPM2 is important for tumour growth and cell survival through modulation of hypoxia-inducible transcription factor expression, mitochondrial function and mitophagy. These findings in cardiac ischaemia and in neuroblastoma suggest that TRPM2 has a basic role in sustaining mitochondrial function and in cell survival that applies to a number of physiological systems and pathophysiological processes including ischaemia-reperfusion injury.
Collapse
Affiliation(s)
- Barbara A Miller
- Departments of Pediatrics and Biochemistry & Molecular Biology, Pennsylvania State University College of Medicine, Hershey, PA, 17033, USA
| | - Joseph Y Cheung
- Center of Translational Medicine and Department of Medicine, Temple University School of Medicine, Philadelphia, PA, 19140, USA
| |
Collapse
|
46
|
Kim JC, Woo SH. Shear stress induces a longitudinal Ca(2+) wave via autocrine activation of P2Y1 purinergic signalling in rat atrial myocytes. J Physiol 2015; 593:5091-109. [PMID: 26377030 DOI: 10.1113/jp271016] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2015] [Accepted: 09/11/2015] [Indexed: 12/25/2022] Open
Abstract
Atrial myocytes are exposed to shear stress during the cardiac cycle and haemodynamic disturbance. In response, they generate a longitudinally propagating global Ca(2+) wave. Here, we investigated the cellular mechanisms underlying the shear stress-mediated Ca(2+) wave, using two-dimensional confocal Ca(2+) imaging combined with a pressurized microflow system in single rat atrial myocytes. Shear stress of ∼16 dyn cm(-2) for 8 s induced ∼1.2 aperiodic longitudinal Ca(2+) waves (∼79 μm s(-1)) with a delay of 0.2-3 s. Pharmacological blockade of ryanodine receptors (RyRs) or inositol 1,4,5-trisphosphate receptors (IP3 Rs) abolished shear stress-induced Ca(2+) wave generation. Furthermore, in atrial myocytes from type 2 IP3R (IP3R2) knock-out mice, shear stress failed to induce longitudinal Ca(2+) waves. The phospholipase C (PLC) inhibitor U73122, but not its inactive analogue U73343, abolished the shear-induced longitudinal Ca(2+) wave. However, pretreating atrial cells with blockers for stretch-activated channels, Na(+)-Ca(2+) exchanger, transient receptor potential melastatin subfamily 4, or nicotinamide adenine dinucleotide phosphate oxidase did not suppress wave generation under shear stress. The P2 purinoceptor inhibitor suramin, and the potent P2Y1 receptor antagonist MRS 2179, both suppressed the Ca(2+) wave, whereas the P2X receptor antagonist, iso-PPADS, did not alter it. Suppression of gap junction hemichannels permeable to ATP or extracellular application of ATP-metabolizing apyrase inhibited the wave. Removal of external Ca(2+) to enhance hemichannel opening facilitated the wave generation. Our data suggest that longitudinally propagating, regenerative Ca(2+) release through RyRs is triggered by P2Y1-PLC-IP3R2 signalling that is activated by gap junction hemichannel-mediated ATP release in atrial myocytes under shear stress.
Collapse
Affiliation(s)
- Joon-Chul Kim
- Laboratory of Physiology, College of Pharmacy, Chungnam National University, 99 Daehak-ro, Yuseong-gu, Daejeon, 305-764, South Korea
| | - Sun-Hee Woo
- Laboratory of Physiology, College of Pharmacy, Chungnam National University, 99 Daehak-ro, Yuseong-gu, Daejeon, 305-764, South Korea
| |
Collapse
|
47
|
Flannery RJ, Kleene NK, Kleene SJ. A TRPM4-dependent current in murine renal primary cilia. Am J Physiol Renal Physiol 2015; 309:F697-707. [PMID: 26290373 PMCID: PMC4609916 DOI: 10.1152/ajprenal.00294.2015] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2015] [Accepted: 08/13/2015] [Indexed: 12/13/2022] Open
Abstract
Defects in primary cilia lead to a variety of human diseases. One of these, polycystic kidney disease, can be caused by defects in a Ca²⁺-gated ion channel (TRPP2) found on the cilium. Other ciliary functions also contribute to cystogenesis, and defects in apical Ca²⁺ homeostasis have been implicated. By recording directly from the native cilia of mIMCD-3 cells, a murine cell line of renal epithelial origin, we have identified a second Ca²⁺-gated channel in the ciliary membrane: the transient receptor potential cation channel, subfamily M, member 4 (TRPM4). In excised primary cilia, TRPM4 was found to have a low sensitivity to Ca²⁺, with an EC₅₀ of 646 μM at +100 mV. It was inhibited by MgATP and by 9-phenanthrol. The channel was not permeable to Ca²⁺ or Cl⁻ and had a permeability ratio PK/PNa of 1.42. Reducing the expression of Trpm4 mRNA with short hairpin (sh) RNA reduced the TRPM4 current by 87% and shortened primary cilia by 43%. When phospholipase C was inhibited, the sensitivity to cytoplasmic Ca²⁺ greatly increased (EC₅₀ = 26 μM at +100 mV), which is consistent with previous reports that phosphatidylinositol 4,5-bisphosphate (PIP2) modulates the channel. MgATP did not restore the channel to a preinactivation state, suggesting that the enzyme or substrate necessary for making PIP2 is not abundant in primary cilia of mIMCD-3 cells. The function of TRPM4 in renal primary cilia is not yet known, but it is likely to influence the apical Ca²⁺ dynamics of the cell, perhaps in tandem with TRPP2.
Collapse
Affiliation(s)
- Richard J Flannery
- Department of Molecular and Cellular Physiology, University of Cincinnati, Cincinnati, Ohio
| | - Nancy K Kleene
- Department of Molecular and Cellular Physiology, University of Cincinnati, Cincinnati, Ohio
| | - Steven J Kleene
- Department of Molecular and Cellular Physiology, University of Cincinnati, Cincinnati, Ohio
| |
Collapse
|
48
|
Guinamard R, Bouvagnet P, Hof T, Liu H, Simard C, Sallé L. TRPM4 in cardiac electrical activity. Cardiovasc Res 2015; 108:21-30. [PMID: 26272755 DOI: 10.1093/cvr/cvv213] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/16/2014] [Accepted: 07/31/2015] [Indexed: 11/12/2022] Open
Abstract
TRPM4 forms a non-selective cation channel activated by internal Ca(2+). Its functional expression was demonstrated in cardiomyocytes of several mammalian species including humans, but the channel is also present in many other tissues. The recent characterization of the TRPM4 inhibitor 9-phenanthrol, and the availability of transgenic mice have helped to clarify the role of TRPM4 in cardiac electrical activity, including diastolic depolarization from the sino-atrial node cells in mouse, rat, and rabbit, as well as action potential duration in mouse cardiomyocytes. In rat and mouse, pharmacological inhibition of TRPM4 prevents cardiac ischaemia-reperfusion injuries and decreases the occurrence of arrhythmias. Several studies have identified TRPM4 mutations in patients with inherited cardiac diseases including conduction blocks and Brugada syndrome. This review identifies TRPM4 as a significant actor in cardiac electrophysiology.
Collapse
Affiliation(s)
- Romain Guinamard
- Groupe Signalisation, Electrophysiologie et Imagerie des Lésions d'Ischémie-Reperfusion Myocardique, EA4650, Université de Caen Basse-Normandie, Sciences D, Esplanade de la Paix, CS 14032, 14032 Caen Cedex 5, France
| | | | - Thomas Hof
- Groupe Signalisation, Electrophysiologie et Imagerie des Lésions d'Ischémie-Reperfusion Myocardique, EA4650, Université de Caen Basse-Normandie, Sciences D, Esplanade de la Paix, CS 14032, 14032 Caen Cedex 5, France
| | - Hui Liu
- Department of Anatomy, Hainan Medical College, Haikou, Hainan 571101, China
| | - Christophe Simard
- Groupe Signalisation, Electrophysiologie et Imagerie des Lésions d'Ischémie-Reperfusion Myocardique, EA4650, Université de Caen Basse-Normandie, Sciences D, Esplanade de la Paix, CS 14032, 14032 Caen Cedex 5, France
| | - Laurent Sallé
- Groupe Signalisation, Electrophysiologie et Imagerie des Lésions d'Ischémie-Reperfusion Myocardique, EA4650, Université de Caen Basse-Normandie, Sciences D, Esplanade de la Paix, CS 14032, 14032 Caen Cedex 5, France
| |
Collapse
|
49
|
Hoffman NE, Miller BA, Wang J, Elrod JW, Rajan S, Gao E, Song J, Zhang XQ, Hirschler-Laszkiewicz I, Shanmughapriya S, Koch WJ, Feldman AM, Madesh M, Cheung JY. Ca²⁺ entry via Trpm2 is essential for cardiac myocyte bioenergetics maintenance. Am J Physiol Heart Circ Physiol 2015; 308:H637-50. [PMID: 25576627 DOI: 10.1152/ajpheart.00720.2014] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Ubiquitously expressed Trpm2 channel limits oxidative stress and preserves mitochondrial function. We first demonstrated that intracellular Ca(2+) concentration increase after Trpm2 activation was due to direct Ca(2+) influx and not indirectly via reverse Na(+)/Ca(2+) exchange. To elucidate whether Ca(2+) entry via Trpm2 is required to maintain cellular bioenergetics, we injected adenovirus expressing green fluorescent protein (GFP), wild-type (WT) Trpm2, and loss-of-function (E960D) Trpm2 mutant into left ventricles of global Trpm2 knockout (gKO) or WT hearts. Five days post-injection, gKO-GFP heart slices had higher reactive oxygen species (ROS) levels but lower oxygen consumption rate (OCR) than WT-GFP heart slices. Trpm2 but not E960D decreased ROS and restored OCR in gKO hearts back to normal levels. In gKO myocytes expressing Trpm2 or its mutants, Trpm2 but not E960D reduced the elevated mitochondrial superoxide (O2(.-)) levels in gKO myocytes. After hypoxia-reoxygenation (H/R), Trpm2 but not E906D or P1018L (inactivates Trpm2 current) lowered O2(.-) levels in gKO myocytes and only in the presence of extracellular Ca(2+), indicating sustained Ca(2+) entry is necessary for Trpm2-mediated preservation of mitochondrial function. After ischemic-reperfusion (I/R), cardiac-specific Trpm2 KO hearts exhibited lower maximal first time derivative of LV pressure rise (+dP/dt) than WT hearts in vivo. After doxorubicin treatment, Trpm2 KO mice had worse survival and lower +dP/dt. We conclude 1) cardiac Trpm2-mediated Ca(2+) influx is necessary to maintain mitochondrial function and protect against H/R injury; 2) Ca(2+) influx via cardiac Trpm2 confers protection against H/R and I/R injury by reducing mitochondrial oxidants; and 3) Trpm2 confers protection in doxorubicin cardiomyopathy.
Collapse
Affiliation(s)
- Nicholas E Hoffman
- Center of Translational Medicine, Temple University School of Medicine, Philadelphia, Pennsylvania; Department of Biochemistry, Temple University School of Medicine, Philadelphia, Pennsylvania; and
| | - Barbara A Miller
- Department of Pediatrics, The Pennsylvania State University College of Medicine, Hershey, Pennsylvania
| | - JuFang Wang
- Center of Translational Medicine, Temple University School of Medicine, Philadelphia, Pennsylvania
| | - John W Elrod
- Center of Translational Medicine, Temple University School of Medicine, Philadelphia, Pennsylvania
| | - Sudasan Rajan
- Center of Translational Medicine, Temple University School of Medicine, Philadelphia, Pennsylvania; Department of Biochemistry, Temple University School of Medicine, Philadelphia, Pennsylvania; and
| | - Erhe Gao
- Center of Translational Medicine, Temple University School of Medicine, Philadelphia, Pennsylvania
| | - Jianliang Song
- Center of Translational Medicine, Temple University School of Medicine, Philadelphia, Pennsylvania
| | - Xue-Qian Zhang
- Center of Translational Medicine, Temple University School of Medicine, Philadelphia, Pennsylvania
| | | | - Santhanam Shanmughapriya
- Center of Translational Medicine, Temple University School of Medicine, Philadelphia, Pennsylvania; Department of Biochemistry, Temple University School of Medicine, Philadelphia, Pennsylvania; and
| | - Walter J Koch
- Center of Translational Medicine, Temple University School of Medicine, Philadelphia, Pennsylvania
| | - Arthur M Feldman
- Center of Translational Medicine, Temple University School of Medicine, Philadelphia, Pennsylvania
| | - Muniswamy Madesh
- Center of Translational Medicine, Temple University School of Medicine, Philadelphia, Pennsylvania; Department of Biochemistry, Temple University School of Medicine, Philadelphia, Pennsylvania; and
| | - Joseph Y Cheung
- Center of Translational Medicine, Temple University School of Medicine, Philadelphia, Pennsylvania; Division of Nephrology, Temple University School of Medicine, Philadelphia, Pennsylvania;
| |
Collapse
|
50
|
Trpm4 gene invalidation leads to cardiac hypertrophy and electrophysiological alterations. PLoS One 2014; 9:e115256. [PMID: 25531103 PMCID: PMC4274076 DOI: 10.1371/journal.pone.0115256] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2014] [Accepted: 11/20/2014] [Indexed: 12/14/2022] Open
Abstract
RATIONALE TRPM4 is a non-selective Ca2+-activated cation channel expressed in the heart, particularly in the atria or conduction tissue. Mutations in the Trpm4 gene were recently associated with several human conduction disorders such as Brugada syndrome. TRPM4 channel has also been implicated at the ventricular level, in inotropism or in arrhythmia genesis due to stresses such as ß-adrenergic stimulation, ischemia-reperfusion, and hypoxia re-oxygenation. However, the physiological role of the TRPM4 channel in the healthy heart remains unclear. OBJECTIVES We aimed to investigate the role of the TRPM4 channel on whole cardiac function with a Trpm4 gene knock-out mouse (Trpm4-/-) model. METHODS AND RESULTS Morpho-functional analysis revealed left ventricular (LV) eccentric hypertrophy in Trpm4-/- mice, with an increase in both wall thickness and chamber size in the adult mouse (aged 32 weeks) when compared to Trpm4+/+ littermate controls. Immunofluorescence on frozen heart cryosections and qPCR analysis showed no fibrosis or cellular hypertrophy. Instead, cardiomyocytes in Trpm4-/- mice were smaller than Trpm4+/+with a higher density. Immunofluorescent labeling for phospho-histone H3, a mitosis marker, showed that the number of mitotic myocytes was increased 3-fold in the Trpm4-/-neonatal stage, suggesting hyperplasia. Adult Trpm4-/- mice presented multilevel conduction blocks, as attested by PR and QRS lengthening in surface ECGs and confirmed by intracardiac exploration. Trpm4-/-mice also exhibited Luciani-Wenckebach atrioventricular blocks, which were reduced following atropine infusion, suggesting paroxysmal parasympathetic overdrive. In addition, Trpm4-/- mice exhibited shorter action potentials in atrial cells. This shortening was unrelated to modifications of the voltage-gated Ca2+ or K+ currents involved in the repolarizing phase. CONCLUSIONS TRPM4 has pleiotropic roles in the heart, including the regulation of conduction and cellular electrical activity which impact heart development.
Collapse
|