1
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Yan X, Li M, Lan P, Xun M, Zhang Y, Shi J, Wang R, Zheng J. Regulation of Na+-K+-ATPase leads to disturbances of isoproterenol-induced cardiac dysfunction via interference of Ca2+-dependent cardiac metabolism. Clin Sci (Lond) 2024; 138:23-42. [PMID: 38060817 DOI: 10.1042/cs20231039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2023] [Revised: 12/06/2023] [Accepted: 12/07/2023] [Indexed: 01/06/2024]
Abstract
Reductions in Na+-K+-ATPase (NKA) activity and expression are often observed in the progress of various reason-induced heart failure (HF). However, NKA α1 mutation or knockdown cannot cause spontaneous heart disease. Whether the abnormal NKA α1 directly contributes to HF pathogenesis remains unknown. Here, we challenge NKA α1+/- mice with isoproterenol to evaluate the role of NKA α1 haploinsufficiency in isoproterenol (ISO)-induced cardiac dysfunction. Genetic knockdown of NKA α1 accelerated ISO-induced cardiac cell hypertrophy, heart fibrosis, and dysfunction. Further studies revealed decreased Krebs cycle, fatty acid oxidation, and mitochondrial OXPHOS in the hearts of NKA α1+/- mice challenged with ISO. In ISO-treated conditions, inhibition of NKA elevated cytosolic Na+, further reduced mitochondrial Ca2+ via mNCE, and then finally down-regulated cardiac cell energy metabolism. In addition, a supplement of DRm217 alleviated ISO-induced heart dysfunction, mitigated cardiac remodeling, and improved cytosolic Na+ and Ca2+ elevation and mitochondrial Ca2+ depression in the NKA α1+/- mouse model. The findings suggest that targeting NKA and mitochondria Ca2+ could be a promising strategy in the treatment of heart disease.
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Affiliation(s)
- Xiaofei Yan
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Xi'an Jiaotong University, Xi'an 710061, China
| | - Meihe Li
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Xi'an Jiaotong University, Xi'an 710061, China
- Hospital of Nephrology, First Affiliated Hospital of Xi'an Jiaotong University, Xi'an 710061, China
| | - Ping Lan
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Xi'an Jiaotong University, Xi'an 710061, China
- Hospital of Nephrology, First Affiliated Hospital of Xi'an Jiaotong University, Xi'an 710061, China
| | - Meng Xun
- Department of Microbiology and Immunology, School of Basic Medical Sciences, Xi'an Jiaotong University, Xi'an 710061, China
| | - Ying Zhang
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Xi'an Jiaotong University, Xi'an 710061, China
- Hospital of Nephrology, First Affiliated Hospital of Xi'an Jiaotong University, Xi'an 710061, China
| | - Jinghui Shi
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Xi'an Jiaotong University, Xi'an 710061, China
- Department of Clinical laboratory in Xi'an Fourth Hospital, Xi'an 710004, China
| | - Ruijia Wang
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Xi'an Jiaotong University, Xi'an 710061, China
| | - Jin Zheng
- Hospital of Nephrology, First Affiliated Hospital of Xi'an Jiaotong University, Xi'an 710061, China
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2
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Elliott SJ, Eykyn TR, Kuchel PW. Multiple quantum filtered nuclear magnetic resonance of 23Na+ in uniformly stretched and compressed hydrogels. J Chem Phys 2023; 159:034903. [PMID: 37462283 DOI: 10.1063/5.0158608] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Accepted: 06/19/2023] [Indexed: 07/22/2023] Open
Abstract
Stretching or compressing hydrogels creates anisotropic environments that lead to motionally averaged alignment of embedded guest quadrupolar nuclear spins such as 23Na+. These distorted hydrogels can elicit a residual quadrupolar coupling that gives an oscillation in the trajectories of single quantum coherences (SQCs) as a function of the evolution time during a spin-echo experiment. We present solutions to equations of motion derived with a Liouvillian superoperator approach, which encompass the coherent quadrupolar interaction in conjunction with relaxation, to give a full analytical description of the evolution trajectories of rank-1 (T^1±1), rank-2 (T^2±1), and rank-3 (T^3±1) SQCs. We performed simultaneous numerical fitting of the experimental 23Na nuclear magnetic resonance (NMR) spectra and rank-2 (T^2±1) and rank-3 (T^3±1) SQC evolution trajectories measured in double and triple quantum filtered experiments, respectively. We estimated values of the quadrupolar coupling constant CQ, rotational correlation time τC, and 3 × 3 Saupe order matrix. We performed simultaneous fitting of the analytical expressions to the experimental data to estimate values of the quadrupolar coupling frequency ωQ/2π, residual quadrupolar coupling ωQ/2π, and corresponding spherical order parameter S0*, which showed a linear dependence on the extent of uniform hydrogel stretching and compression. The analytical expressions were completely concordant with the numerical approach. The insights gained here can be extended to more complicated (biological) systems such as 23Na+ bound to proteins or located inside and outside living cells in high-field NMR experiments and, by extension, to the anisotropic environments found in vivo with 23Na magnetic resonance imaging.
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Affiliation(s)
- S J Elliott
- Molecular Sciences Research Hub, Imperial College London, London W12 0BZ, United Kingdom
| | - T R Eykyn
- School of Biomedical Engineering and Imaging Sciences, King's College London, St Thomas' Hospital, London SE1 7EH, United Kingdom
| | - P W Kuchel
- School of Life and Environmental Sciences, University of Sydney, Sydney, NSW 2006, Australia
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3
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Nelson G, Ye B, Schock M, Lustgarten DL, Mayhew EK, Palmer BM, Meyer M. Heart rate changes and myocardial sodium. Physiol Rep 2022; 10:e15446. [PMID: 36065860 PMCID: PMC9446395 DOI: 10.14814/phy2.15446] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2021] [Revised: 04/14/2022] [Accepted: 08/14/2022] [Indexed: 06/15/2023] Open
Abstract
Historic studies with sodium ion (Na+ ) micropipettes and first-generation fluorescent probes suggested that an increase in heart rate results in higher intracellular Na+ -levels. Using a dual fluorescence indicator approach, we simultaneously assessed the dynamic changes in intracellular Na+ and calcium (Ca2+ ) with measures of force development in isolated excitable myocardial strip preparations from rat and human left ventricular myocardium at different stimulation rates and modeled the Na+ -effects on the sodium-calcium exchanger (NCX). To gain further insight into the effects of heart rate on intracellular Na+ -regulation and sodium/potassium ATPase (NKA) function, Na+ , and potassium ion (K+ ) levels were assessed in the coronary effluent (CE) of paced human subjects. Increasing the stimulation rate from 60/min to 180/min led to a transient Na+ -peak followed by a lower Na+ -level, whereas the return to 60/min had the opposite effect leading to a transient Na+ -trough followed by a higher Na+ -level. The presence of the Na+ -peak and trough suggests a delayed regulation of NKA activity in response to changes in heart rate. This was clinically confirmed in the pacing study where CE-K+ levels were raised above steady-state levels with rapid pacing and reduced after pacing cessation. Despite an initial Na+ peak that is due to a delayed increase in NKA activity, an increase in heart rate was associated with lower, and not higher, Na+ -levels in the myocardium. The dynamic changes in Na+ unveil the adaptive role of NKA to maintain Na+ and K+ -gradients that preserve membrane potential and cellular Ca2+ -hemostasis.
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Affiliation(s)
- Gabrielle Nelson
- Department of MedicineLillehei Heart Institute, University of Minnesota College of MedicineMinneapolisMinnesotaUSA
| | - Bo Ye
- Department of MedicineLillehei Heart Institute, University of Minnesota College of MedicineMinneapolisMinnesotaUSA
| | - Morgan Schock
- Department of MedicineLillehei Heart Institute, University of Minnesota College of MedicineMinneapolisMinnesotaUSA
| | - Daniel L. Lustgarten
- Department of Medicine and PhysiologyUniversity of Vermont Larner College of MedicineBurlingtonVermontUSA
| | - Elisabeth K. Mayhew
- Department of Medicine and PhysiologyUniversity of Vermont Larner College of MedicineBurlingtonVermontUSA
| | - Bradley M. Palmer
- Department of Medicine and PhysiologyUniversity of Vermont Larner College of MedicineBurlingtonVermontUSA
| | - Markus Meyer
- Department of MedicineLillehei Heart Institute, University of Minnesota College of MedicineMinneapolisMinnesotaUSA
- Department of Medicine and PhysiologyUniversity of Vermont Larner College of MedicineBurlingtonVermontUSA
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4
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Karmazyn M, Pierce GN, Fliegel L. The Remaining Conundrum of the Role of the Na +/H + Exchanger Isoform 1 (NHE1) in Cardiac Physiology and Pathology: Can It Be Rectified? Rev Cardiovasc Med 2022; 23:284. [PMID: 39076631 PMCID: PMC11266974 DOI: 10.31083/j.rcm2308284] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Revised: 06/29/2022] [Accepted: 07/08/2022] [Indexed: 07/31/2024] Open
Abstract
The mammalian Na + /H + exchanger (NHE) is a family of ubiquitous membrane proteins present in humans. Isoform one (NHE1) is present on the plasma membrane and regulates intracellular pH by removal of one intracellular proton in exchange for one extracellular sodium thus functioning as an electroneutral process. Human NHE1 has a 500 amino acid membrane domain plus a C-terminal 315 amino acid, regulatory cytosolic tail. It is regulated through a cytosolic regulatory C-terminal tail which is subject to phosphorylation and is modulated by proteins and lipids. Substantial evidence has implicated NHE1 activity in both myocardial ischemia and reperfusion damage and myocardial remodeling resulting in heart failure. Experimental data show excellent cardioprotection with NHE1 inhibitors although results from clinical results have been mixed. In cardiac surgery patients receiving the NHE1 inhibitor cariporide, subgroups showed beneficial effects of treatment. However, in one trial this was associated with a significantly increased incidence of ischemic strokes. This likely reflected both inappropriate dosing regimens as well as overly high drug doses. We suggest that further progress towards NHE1 inhibition as a treatment for cardiovascular disease is warranted through the development of novel compounds to inhibit NHE1 that are structurally different than those previously used in compromised clinical trials. Some novel pyrazinoyl guanidine inhibitors of NHE1 are already in development and the recent elucidation of the three-dimensional structure of the NHE1 protein and identity of the inhibitor binding site may facilitate development. An alternative approach may also be to control the endogenous regulation of activity of NHE1, which is activated in disease.
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Affiliation(s)
- Morris Karmazyn
- Department of Physiology and Pharmacology, University of Western Ontario, London, ON N6A 5C1, Canada
| | - Grant N. Pierce
- Institute of Cardiovascular Sciences, Albrechtsen Research Centre, St. Boniface Hospital, and Department of Physiology and Pathophysiology, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, MB R2H 2A6, Canada
| | - Larry Fliegel
- Department of Biochemistry, University Alberta, Edmonton, AB T6G 2H7, Canada
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5
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Patel N, Yaqoob MM, Aksentijevic D. Cardiac metabolic remodelling in chronic kidney disease. Nat Rev Nephrol 2022; 18:524-537. [DOI: 10.1038/s41581-022-00576-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/14/2022] [Indexed: 11/09/2022]
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6
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Horváth B, Szentandrássy N, Almássy J, Dienes C, Kovács ZM, Nánási PP, Banyasz T. Late Sodium Current of the Heart: Where Do We Stand and Where Are We Going? Pharmaceuticals (Basel) 2022; 15:ph15020231. [PMID: 35215342 PMCID: PMC8879921 DOI: 10.3390/ph15020231] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2022] [Revised: 02/07/2022] [Accepted: 02/09/2022] [Indexed: 02/05/2023] Open
Abstract
Late sodium current has long been linked to dysrhythmia and contractile malfunction in the heart. Despite the increasing body of accumulating information on the subject, our understanding of its role in normal or pathologic states is not complete. Even though the role of late sodium current in shaping action potential under physiologic circumstances is debated, it’s unquestioned role in arrhythmogenesis keeps it in the focus of research. Transgenic mouse models and isoform-specific pharmacological tools have proved useful in understanding the mechanism of late sodium current in health and disease. This review will outline the mechanism and function of cardiac late sodium current with special focus on the recent advances of the area.
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Affiliation(s)
- Balázs Horváth
- Department of Physiology, University of Debrecen, 4032 Debrecen, Hungary; (B.H.); (N.S.); (J.A.); (C.D.); (Z.M.K.); (P.P.N.)
| | - Norbert Szentandrássy
- Department of Physiology, University of Debrecen, 4032 Debrecen, Hungary; (B.H.); (N.S.); (J.A.); (C.D.); (Z.M.K.); (P.P.N.)
- Department of Basic Medical Sciences, Faculty of Dentistry, University of Debrecen, 4032 Debrecen, Hungary
| | - János Almássy
- Department of Physiology, University of Debrecen, 4032 Debrecen, Hungary; (B.H.); (N.S.); (J.A.); (C.D.); (Z.M.K.); (P.P.N.)
| | - Csaba Dienes
- Department of Physiology, University of Debrecen, 4032 Debrecen, Hungary; (B.H.); (N.S.); (J.A.); (C.D.); (Z.M.K.); (P.P.N.)
| | - Zsigmond Máté Kovács
- Department of Physiology, University of Debrecen, 4032 Debrecen, Hungary; (B.H.); (N.S.); (J.A.); (C.D.); (Z.M.K.); (P.P.N.)
| | - Péter P. Nánási
- Department of Physiology, University of Debrecen, 4032 Debrecen, Hungary; (B.H.); (N.S.); (J.A.); (C.D.); (Z.M.K.); (P.P.N.)
- Department of Dental Physiology and Pharmacology, University of Debrecen, 4032 Debrecen, Hungary
| | - Tamas Banyasz
- Department of Physiology, University of Debrecen, 4032 Debrecen, Hungary; (B.H.); (N.S.); (J.A.); (C.D.); (Z.M.K.); (P.P.N.)
- Correspondence: ; Tel.: +36-(52)-255-575; Fax: +36-(52)-255-116
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7
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Chung YJ, Park KC, Tokar S, Eykyn TR, Fuller W, Pavlovic D, Swietach P, Shattock MJ. Off-target effects of sodium-glucose co-transporter 2 blockers: empagliflozin does not inhibit Na+/H+ exchanger-1 or lower [Na+]i in the heart. Cardiovasc Res 2021; 117:2794-2806. [PMID: 33135077 PMCID: PMC8683707 DOI: 10.1093/cvr/cvaa323] [Citation(s) in RCA: 91] [Impact Index Per Article: 30.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Revised: 09/28/2020] [Accepted: 11/02/2020] [Indexed: 12/17/2022] Open
Abstract
AIMS Emipagliflozin (EMPA) is a potent inhibitor of the renal sodium-glucose co-transporter 2 (SGLT2) and an effective treatment for type-2 diabetes. In patients with diabetes and heart failure, EMPA has cardioprotective effects independent of improved glycaemic control, despite SGLT2 not being expressed in the heart. A number of non-canonical mechanisms have been proposed to explain these cardiac effects, most notably an inhibitory action on cardiac Na+/H+ exchanger 1 (NHE1), causing a reduction in intracellular [Na+] ([Na+]i). However, at resting intracellular pH (pHi), NHE1 activity is very low and its pharmacological inhibition is not expected to meaningfully alter steady-state [Na+]i. We re-evaluate this putative EMPA target by measuring cardiac NHE1 activity. METHODS AND RESULTS The effect of EMPA on NHE1 activity was tested in isolated rat ventricular cardiomyocytes from measurements of pHi recovery following an ammonium pre-pulse manoeuvre, using cSNARF1 fluorescence imaging. Whereas 10 µM cariporide produced near-complete inhibition, there was no evidence for NHE1 inhibition with EMPA treatment (1, 3, 10, or 30 µM). Intracellular acidification by acetate-superfusion evoked NHE1 activity and raised [Na+]i, reported by sodium binding benzofuran isophthalate (SBFI) fluorescence, but EMPA did not ablate this rise. EMPA (10 µM) also had no significant effect on the rate of cytoplasmic [Na+]i rise upon superfusion of Na+-depleted cells with Na+-containing buffers. In Langendorff-perfused mouse, rat and guinea pig hearts, EMPA did not affect [Na+]i at baseline nor pHi recovery following acute acidosis, as measured by 23Na triple quantum filtered NMR and 31P NMR, respectively. CONCLUSIONS Our findings indicate that cardiac NHE1 activity is not inhibited by EMPA (or other SGLT2i's) and EMPA has no effect on [Na+]i over a wide range of concentrations, including the therapeutic dose. Thus, the beneficial effects of SGLT2i's in failing hearts should not be interpreted in terms of actions on myocardial NHE1 or intracellular [Na+].
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Affiliation(s)
- Yu Jin Chung
- British Heart Foundation Centre of Research Excellence, King’s College London, The Rayne Institute, St Thomas’ Hospital, Lambeth Palace Road, London SE1 7EH, UK
| | - Kyung Chan Park
- Department of Physiology, Anatomy and Genetics, Parks Road, Oxford, OX1 3PT, UK
| | - Sergiy Tokar
- British Heart Foundation Centre of Research Excellence, King’s College London, The Rayne Institute, St Thomas’ Hospital, Lambeth Palace Road, London SE1 7EH, UK
| | - Thomas R Eykyn
- British Heart Foundation Centre of Research Excellence, King’s College London, The Rayne Institute, St Thomas’ Hospital, Lambeth Palace Road, London SE1 7EH, UK
- School of Biomedical Engineering and Imaging Sciences, King’s College London, The Rayne Institute, St Thomas' Hospital, Lambeth Palace Road, London SE1 7EH, UK
| | - William Fuller
- Institute of Cardiovascular & Medical Sciences, Sir James Black Building, University of Glasgow, University Avenue, Glasgow G12 8QQ, UK
| | - Davor Pavlovic
- Institute for Cardiovascular Sciences, University of Birmingham, Wolfson Drive, Birmingham B15 2TT, UK
| | - Pawel Swietach
- Department of Physiology, Anatomy and Genetics, Parks Road, Oxford, OX1 3PT, UK
| | - Michael J Shattock
- British Heart Foundation Centre of Research Excellence, King’s College London, The Rayne Institute, St Thomas’ Hospital, Lambeth Palace Road, London SE1 7EH, UK
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8
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With a grain of salt: Sodium elevation and metabolic remodelling in heart failure. J Mol Cell Cardiol 2021; 161:106-115. [PMID: 34371034 PMCID: PMC7611640 DOI: 10.1016/j.yjmcc.2021.08.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Revised: 07/09/2021] [Accepted: 08/03/2021] [Indexed: 12/14/2022]
Abstract
Elevated intracellular Na (Nai) and metabolic impairment are interrelated pathophysiological features of the failing heart (HF). There have been a number of studies showing that myocardial sodium elevation subtly affects mitochondrial function. During contraction, mitochondrial calcium (Camito) stimulates a variety of TCA cycle enzymes, thereby providing reducing equivalents to maintain ATP supply. Nai elevation has been shown to impact Camito; however, whether metabolic remodelling in HF is caused by increased Nai has only been recently demonstrated. This novel insight may help to elucidate the contribution of metabolic remodelling in the pathophysiology of HF, the lack of efficacy of current HF therapies and a rationale for the development of future metabolism-targeting treatments. Here we review the relationship between Na pump inhibition, elevated Nai, and altered metabolic profile in the context of HF and their link to metabolic (in)flexibility and mitochondrial reprogramming.
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9
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Assali EA, Sekler I. Sprinkling salt on mitochondria: The metabolic and pathophysiological roles of mitochondrial Na + signaling mediated by NCLX. Cell Calcium 2021; 97:102416. [PMID: 34062329 DOI: 10.1016/j.ceca.2021.102416] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Revised: 04/25/2021] [Accepted: 04/26/2021] [Indexed: 11/25/2022]
Abstract
NCLX, the mitochondrial Na+/Ca2+ transporter is a key player in Ca2+ signaling. However, its role in Na+ signaling is poorly understood. In this review we focus on Na+ signaling by NCLX, and discuss recent physiological and pathophysiological roles attributed to the Na+ influx into mitochondria.
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Affiliation(s)
- Essam A Assali
- Department of Physiology and Cell Biology, Faculty of Health Sciences, Ben-Gurion University, Beer-Sheva, 84105, Israel
| | - Israel Sekler
- Department of Physiology and Cell Biology, Faculty of Health Sciences, Ben-Gurion University, Beer-Sheva, 84105, Israel.
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10
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Gök C, Fuller W. Topical review: Shedding light on molecular and cellular consequences of NCX1 palmitoylation. Cell Signal 2020; 76:109791. [DOI: 10.1016/j.cellsig.2020.109791] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Revised: 09/22/2020] [Accepted: 09/22/2020] [Indexed: 01/21/2023]
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11
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Intracellular sodium elevation reprograms cardiac metabolism. Nat Commun 2020; 11:4337. [PMID: 32859897 PMCID: PMC7455741 DOI: 10.1038/s41467-020-18160-x] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2019] [Accepted: 07/10/2020] [Indexed: 12/12/2022] Open
Abstract
Intracellular Na elevation in the heart is a hallmark of pathologies where both acute and chronic metabolic remodelling occurs. Here, we assess whether acute (75 μM ouabain 100 nM blebbistatin) or chronic myocardial Nai load (PLM3SA mouse) are causally linked to metabolic remodelling and whether the failing heart shares a common Na-mediated metabolic ‘fingerprint’. Control (PLMWT), transgenic (PLM3SA), ouabain-treated and hypertrophied Langendorff-perfused mouse hearts are studied by 23Na, 31P, 13C NMR followed by 1H-NMR metabolomic profiling. Elevated Nai leads to common adaptive metabolic alterations preceding energetic impairment: a switch from fatty acid to carbohydrate metabolism and changes in steady-state metabolite concentrations (glycolytic, anaplerotic, Krebs cycle intermediates). Inhibition of mitochondrial Na/Ca exchanger by CGP37157 ameliorates the metabolic changes. In silico modelling indicates altered metabolic fluxes (Krebs cycle, fatty acid, carbohydrate, amino acid metabolism). Prevention of Nai overload or inhibition of Na/Camito may be a new approach to ameliorate metabolic dysregulation in heart failure. The failing heart is characterised by both alterations in mitochondrial metabolism and an elevation of cytosolic sodium. Here, the authors use 23Na NMR and metabolic profiling to show these are related, and that elevation in intracellular Na reprograms cardiac substrate utilisation via effects on mitochondrial Na/Ca exchange.
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12
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Hilgemann DW. Control of cardiac contraction by sodium: Promises, reckonings, and new beginnings. Cell Calcium 2019; 85:102129. [PMID: 31835176 DOI: 10.1016/j.ceca.2019.102129] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Revised: 11/20/2019] [Accepted: 11/20/2019] [Indexed: 12/12/2022]
Abstract
Several generations of cardiac physiologists have verified that basal cardiac contractility depends strongly on the transsarcolemmal Na gradient, and the underlying molecular mechanisms that link cardiac excitation-contraction coupling (ECC) to the Na gradient have been elucidated in good detail for more than 30 years. In brief, small increases of cytoplasmic Na push cardiac (NCX1) Na/Ca exchangers to increase contractility by increasing the myocyte Ca load. Accordingly, basal cardiac contractility is expected to be physiologically regulated by pathways that modify the cardiac Na gradient and the function of Na transporters. Assuming that this expectation is correct, it remains to be elucidated how in detail signaling pathways affecting the cardiac Na gradient are controlled in response to changing cardiac output requirements. Some puzzle pieces that may facilitate progress are outlined in this short review. Key open issues include (1) whether the concept of local Na gradients is viable, (2) how in detail Na channels, Na transporters and Na/K pumps are regulated by lipids and metabolic processes, (3) the physiological roles of Na/K pump inactivation, and (4) the possibility that key diffusible signaling molecules remain to be discovered.
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Affiliation(s)
- Donald W Hilgemann
- Department of Physiology, University of Texas Southwestern Medical Center, Dallas, TX, 75235, USA.
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13
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Abstract
Inflammatory processes underlie many diseases associated with injury of the heart muscle, including conditions without an obvious inflammatory pathogenic component such as hypertensive and diabetic cardiomyopathy. Persistence of cardiac inflammation can cause irreversible structural and functional deficits. Some are induced by direct damage of the heart muscle by cellular and soluble mediators but also by metabolic adaptations sustained by the inflammatory microenvironment. It is well established that both cardiomyocytes and immune cells undergo metabolic reprogramming in the site of inflammation, which allow them to deal with decreased availability of nutrients and oxygen. However, like in cancer, competition for nutrients and increased production of signalling metabolites such as lactate initiate a metabolic cross-talk between immune cells and cardiomyocytes which, we propose, might tip the balance between resolution of the inflammation versus adverse cardiac remodeling. Here we review our current understanding of the metabolic reprogramming of both heart tissue and immune cells during inflammation, and we discuss potential key mechanisms by which these metabolic responses intersect and influence each other and ultimately define the prognosis of the inflammatory process in the heart.
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Affiliation(s)
- Federica M Marelli-Berg
- William Harvey Research Institute, Queen Mary University of London, Charterhouse Square, London EC1M 6BQ, United Kingdom.,Centre for Inflammation and Therapeutic Innovation, Queen Mary University of London, Charterhouse Square, London EC1M 6BQ, United Kingdom
| | - Dunja Aksentijevic
- School of Biological and Chemical Sciences, Queen Mary University of London, G.E. Fogg Building, Mile End Road, London E1 4NS, United Kingdom.,Centre for Inflammation and Therapeutic Innovation, Queen Mary University of London, Charterhouse Square, London EC1M 6BQ, United Kingdom
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14
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Lott J, Platt T, Niesporek SC, Paech D, G. R. Behl N, Niendorf T, Bachert P, Ladd ME, Nagel AM. Corrections of myocardial tissue sodium concentration measurements in human cardiac
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Na MRI at 7 Tesla. Magn Reson Med 2019; 82:159-173. [DOI: 10.1002/mrm.27703] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2018] [Revised: 01/25/2019] [Accepted: 01/31/2019] [Indexed: 12/24/2022]
Affiliation(s)
- Johanna Lott
- German Cancer Research Center (DKFZ), Medical Physics in Radiology Heidelberg Germany
- University of Heidelberg, Faculty of Physics and Astronomy Heidelberg Germany
| | - Tanja Platt
- German Cancer Research Center (DKFZ), Medical Physics in Radiology Heidelberg Germany
| | | | - Daniel Paech
- German Cancer Research Center (DKFZ) Radiology, Heidelberg Germany
| | - Nicolas G. R. Behl
- German Cancer Research Center (DKFZ), Medical Physics in Radiology Heidelberg Germany
| | - Thoralf Niendorf
- Max Delbrueck Center for Molecular Medicine in the Helmholtz Association Berlin Germany
- MRI. TOOLS GmbH Berlin Germany
| | - Peter Bachert
- German Cancer Research Center (DKFZ), Medical Physics in Radiology Heidelberg Germany
- University of Heidelberg, Faculty of Physics and Astronomy Heidelberg Germany
| | - Mark E. Ladd
- German Cancer Research Center (DKFZ), Medical Physics in Radiology Heidelberg Germany
- University of Heidelberg, Faculty of Physics and Astronomy Heidelberg Germany
- University of Heidelberg Faculty of Medicine Heidelberg Germany
| | - Armin M. Nagel
- German Cancer Research Center (DKFZ), Medical Physics in Radiology Heidelberg Germany
- Friedrich‐Alexander‐Universität Erlangen‐Nürnberg (FAU), University Hospital Erlangen Institute of Radiology Erlangen Germany
- Friedrich‐Alexander‐Universität Erlangen‐Nürnberg (FAU) Institute of Medical Physics Erlangen Germany
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15
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23-Sodium magnetic resonance imaging of the human heart revisited: new insights in patients with Conn’s syndrome. Eur Heart J Cardiovasc Imaging 2018; 20:255-256. [DOI: 10.1093/ehjci/jey151] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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