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van der Horst J, Møller S, Kjeldsen SAS, Wojtaszewski JFP, Hellsten Y, Jepps TA. Functional sympatholysis in mouse skeletal muscle involves sarcoplasmic reticulum swelling in arterial smooth muscle cells. Physiol Rep 2021; 9:e15133. [PMID: 34851043 PMCID: PMC8634630 DOI: 10.14814/phy2.15133] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Revised: 11/12/2021] [Accepted: 11/14/2021] [Indexed: 11/24/2022] Open
Abstract
The vasoconstrictive effect of sympathetic activity is attenuated in contracting skeletal muscle (functional sympatholysis), allowing increased blood supply to the working muscle but the underlying mechanisms are incompletely understood. The purpose of this study was to examine α-adrenergic receptor responsiveness in isolated artery segments from non-exercised and exercised mice, using wire myography. Isometric tension recordings performed on femoral artery segments from exercised mice showed decreased α-adrenergic receptor responsiveness compared to non-exercised mice (logEC50 -5.2 ± 0.04 M vs. -5.7 ± 0.08 M, respectively). In contrast, mesenteric artery segments from exercised mice displayed similar α-adrenergic receptor responses compared to non-exercised mice. Responses to the vasoconstrictor serotonin (5-HT) and vasodilator isoprenaline, were similar in femoral artery segments from non-exercised and exercised mice. To study sarcoplasmic reticulum (SR) function, we examined arterial contractions induced by caffeine, which depletes SR Ca2+ and thapsigargin, which inhibits SR Ca2+ -ATPase (SERCA) and SR Ca2+ uptake. Arterial contractions to both caffeine and thapsigargin were increased in femoral artery segment from exercised compared to non-exercised mice. Furthermore, 3D electron microscopy imaging of the arterial wall showed SR volume/length ratio increased 157% in smooth muscle cells of the femoral artery from the exercised mice, whereas there was no difference in SR volume/length ratio in mesenteric artery segments. These results show that in arteries surrounding exercising muscle, the α-adrenergic receptor constrictions are blunted, which can be attributed to swollen smooth muscle cell SR's, likely due to increased Ca2+ content that is possibly reducing free intracellular Ca2+ available for contraction. Overall, this study uncovers a previously unknown mechanism underlying functional sympatholysis.
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Affiliation(s)
- Jennifer van der Horst
- Department of Biomedical SciencesUniversity of CopenhagenCopenhagenDenmark
- Department of Nutrition, Exercise and SportsThe August Krogh Section for Human PhysiologyUniversity of CopenhagenCopenhagenDenmark
| | - Sophie Møller
- Department of Nutrition, Exercise and SportsThe August Krogh Section for Human PhysiologyUniversity of CopenhagenCopenhagenDenmark
| | | | - Jørgen F. P. Wojtaszewski
- Department of Nutrition, Exercise and SportsThe August Krogh Section for Molecular PhysiologyUniversity of CopenhagenCopenhagenDenmark
| | - Ylva Hellsten
- Department of Nutrition, Exercise and SportsThe August Krogh Section for Human PhysiologyUniversity of CopenhagenCopenhagenDenmark
| | - Thomas A. Jepps
- Department of Biomedical SciencesUniversity of CopenhagenCopenhagenDenmark
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Reinhardt F, Beneke K, Pavlidou NG, Conradi L, Reichenspurner H, Hove-Madsen L, Molina CE. Abnormal Calcium Handling in Atrial Fibrillation Is Linked to Changes in Cyclic AMP Dependent Signaling. Cells 2021; 10:cells10113042. [PMID: 34831263 PMCID: PMC8616167 DOI: 10.3390/cells10113042] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Revised: 10/22/2021] [Accepted: 11/02/2021] [Indexed: 01/03/2023] Open
Abstract
Both, the decreased L-type Ca2+ current (ICa,L) density and increased spontaneous Ca2+ release from the sarcoplasmic reticulum (SR), have been associated with atrial fibrillation (AF). In this study, we tested the hypothesis that remodeling of 3′,5′-cyclic adenosine monophosphate (cAMP)-dependent protein kinase A (PKA) signaling is linked to these compartment-specific changes (up- or down-regulation) in Ca2+-handling. Perforated patch-clamp experiments were performed in atrial myocytes from 53 patients with AF and 104 patients in sinus rhythm (Ctl). A significantly higher frequency of transient inward currents (ITI) activated by spontaneous Ca2+ release was confirmed in myocytes from AF patients. Next, inhibition of PKA by H-89 promoted a stronger effect on the ITI frequency in these myocytes compared to myocytes from Ctl patients (7.6-fold vs. 2.5-fold reduction), while the β-agonist isoproterenol (ISO) caused a greater increase in Ctl patients (5.5-fold vs. 2.1-fold). ICa,L density was larger in myocytes from Ctl patients at baseline (p < 0.05). However, the effect of ISO on ICa,L density was only slightly stronger in AF than in Ctl myocytes (3.6-fold vs. 2.7-fold). Interestingly, a significant reduction of ICa,L and Ca2+ sparks was observed upon Ca2+/Calmodulin-dependent protein kinase II inhibition by KN-93, but this inhibition had no effect on ITI. Fluorescence resonance energy transfer (FRET) experiments showed that although AF promoted cytosolic desensitization to β-adrenergic stimulation, ISO increased cAMP to similar levels in both groups of patients in the L-type Ca2+ channel and ryanodine receptor compartments. Basal cAMP signaling also showed compartment-specific regulation by phosphodiesterases in atrial myocytes from 44 Ctl and 43 AF patients. Our results suggest that AF is associated with opposite changes in compartmentalized PKA/cAMP-dependent regulation of ICa,L (down-regulation) and ITI (up-regulation).
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Affiliation(s)
- Franziska Reinhardt
- Department of Cardiovascular Surgery, University Heart & Vascular Center Hamburg UKE, 20251 Hamburg, Germany; (F.R.); (L.C.); (H.R.)
- German Center for Cardiovascular Research (DZHK), Partner Site Hamburg/Kiel/Lübeck, 20251 Hamburg, Germany; (K.B.); (N.G.P.)
| | - Kira Beneke
- German Center for Cardiovascular Research (DZHK), Partner Site Hamburg/Kiel/Lübeck, 20251 Hamburg, Germany; (K.B.); (N.G.P.)
- Institute of Experimental Cardiovascular Research, University Medical Center Hamburg-Eppendorf (UKE), 20251 Hamburg, Germany
| | - Nefeli Grammatica Pavlidou
- German Center for Cardiovascular Research (DZHK), Partner Site Hamburg/Kiel/Lübeck, 20251 Hamburg, Germany; (K.B.); (N.G.P.)
- Institute of Experimental Cardiovascular Research, University Medical Center Hamburg-Eppendorf (UKE), 20251 Hamburg, Germany
| | - Lenard Conradi
- Department of Cardiovascular Surgery, University Heart & Vascular Center Hamburg UKE, 20251 Hamburg, Germany; (F.R.); (L.C.); (H.R.)
| | - Hermann Reichenspurner
- Department of Cardiovascular Surgery, University Heart & Vascular Center Hamburg UKE, 20251 Hamburg, Germany; (F.R.); (L.C.); (H.R.)
- Institute of Experimental Cardiovascular Research, University Medical Center Hamburg-Eppendorf (UKE), 20251 Hamburg, Germany
| | - Leif Hove-Madsen
- Biomedical Research Institute Barcelona, IIBB-CSIC and IIB Sant Pau, Hospital de la Santa Creu i Sant Pau, 08025 Barcelona, Spain;
| | - Cristina E. Molina
- German Center for Cardiovascular Research (DZHK), Partner Site Hamburg/Kiel/Lübeck, 20251 Hamburg, Germany; (K.B.); (N.G.P.)
- Institute of Experimental Cardiovascular Research, University Medical Center Hamburg-Eppendorf (UKE), 20251 Hamburg, Germany
- Correspondence: ; Tel.: +49-407-4105-7095
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Salvage SC, Gallant EM, Fraser JA, Huang CLH, Dulhunty AF. Flecainide Paradoxically Activates Cardiac Ryanodine Receptor Channels under Low Activity Conditions: A Potential Pro-Arrhythmic Action. Cells 2021; 10:cells10082101. [PMID: 34440870 PMCID: PMC8394964 DOI: 10.3390/cells10082101] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2021] [Revised: 08/07/2021] [Accepted: 08/10/2021] [Indexed: 12/02/2022] Open
Abstract
Cardiac ryanodine receptor (RyR2) mutations are implicated in the potentially fatal catecholaminergic polymorphic ventricular tachycardia (CPVT) and in atrial fibrillation. CPVT has been successfully treated with flecainide monotherapy, with occasional notable exceptions. Reported actions of flecainide on cardiac sodium currents from mice carrying the pro-arrhythmic homozygotic RyR2-P2328S mutation prompted our explorations of the effects of flecainide on their RyR2 channels. Lipid bilayer electrophysiology techniques demonstrated a novel, paradoxical increase in RyR2 activity. Preceding flecainide exposure, channels were mildly activated by 1 mM luminal Ca2+ and 1 µM cytoplasmic Ca2+, with open probabilities (Po) of 0.03 ± 0.01 (wild type, WT) or 0.096 ± 0.024 (P2328S). Open probability (Po) increased within 0.5 to 3 min of exposure to 0.5 to 5.0 µM cytoplasmic flecainide, then declined with higher concentrations of flecainide. There were no such increases in a subset of high Po channels with Po ≥ 0.08, although Po then declined with ≥5 µM (WT) or ≥50 µM flecainide (P2328S). On average, channels with Po < 0.08 were significantly activated by 0.5 to 10 µM of flecainide (WT) or 0.5 to 50 µM of flecainide (P2328S). These results suggest that flecainide can bind to separate activation and inhibition sites on RyR2, with activation dominating in lower activity channels and inhibition dominating in more active channels.
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Affiliation(s)
- Samantha C. Salvage
- Physiological Laboratory, University of Cambridge, Downing Street, Cambridge CB2 3EG, UK; (S.C.S.); (J.A.F.); (C.L.-H.H.)
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge CB2 1QW, UK
| | - Esther M. Gallant
- Eccles Institute of Neuroscience, John Curtin School of Medical Research, The Australian National University, 131 Garran Road, Acton 2601, Australia;
| | - James A. Fraser
- Physiological Laboratory, University of Cambridge, Downing Street, Cambridge CB2 3EG, UK; (S.C.S.); (J.A.F.); (C.L.-H.H.)
| | - Christopher L.-H. Huang
- Physiological Laboratory, University of Cambridge, Downing Street, Cambridge CB2 3EG, UK; (S.C.S.); (J.A.F.); (C.L.-H.H.)
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge CB2 1QW, UK
| | - Angela F. Dulhunty
- Eccles Institute of Neuroscience, John Curtin School of Medical Research, The Australian National University, 131 Garran Road, Acton 2601, Australia;
- Correspondence:
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Maiuolo J, Carresi C, Gliozzi M, Musolino V, Scarano F, Coppoletta AR, Guarnieri L, Nucera S, Scicchitano M, Bosco F, Ruga S, Zito MC, Macri R, Cardamone A, Serra M, Mollace R, Tavernese A, Mollace V. Effects of Bergamot Polyphenols on Mitochondrial Dysfunction and Sarcoplasmic Reticulum Stress in Diabetic Cardiomyopathy. Nutrients 2021; 13:nu13072476. [PMID: 34371986 PMCID: PMC8308586 DOI: 10.3390/nu13072476] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 07/18/2021] [Accepted: 07/18/2021] [Indexed: 12/14/2022] Open
Abstract
Cardiovascular disease is the leading cause of death and disability in the Western world. In order to safeguard the structure and the functionality of the myocardium, it is extremely important to adequately support the cardiomyocytes. Two cellular organelles of cardiomyocytes are essential for cell survival and to ensure proper functioning of the myocardium: mitochondria and the sarcoplasmic reticulum. Mitochondria are responsible for the energy metabolism of the myocardium, and regulate the processes that can lead to cell death. The sarcoplasmic reticulum preserves the physiological concentration of the calcium ion, and triggers processes to protect the structural and functional integrity of the proteins. The alterations of these organelles can damage myocardial functioning. A proper nutritional balance regarding the intake of macronutrients and micronutrients leads to a significant improvement in the symptoms and consequences of heart disease. In particular, the Mediterranean diet, characterized by a high consumption of plant-based foods, small quantities of red meat, and high quantities of olive oil, reduces and improves the pathological condition of patients with heart failure. In addition, nutritional support and nutraceutical supplementation in patients who develop heart failure can contribute to the protection of the failing myocardium. Since polyphenols have numerous beneficial properties, including anti-inflammatory and antioxidant properties, this review gathers what is known about the beneficial effects of polyphenol-rich bergamot fruit on the cardiovascular system. In particular, the role of bergamot polyphenols in mitochondrial and sarcoplasmic dysfunctions in diabetic cardiomyopathy is reported.
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Affiliation(s)
- Jessica Maiuolo
- IRC-FSH Department of Health Sciences, University “Magna Græcia” of Catanzaro, Campus Universitario di Germaneto, 88100 Catanzaro, Italy; (J.M.); (C.C.); (M.G.); (V.M.); (F.S.); (A.R.C.); (L.G.); (S.N.); (M.S.); (F.B.); (S.R.); (M.C.Z.); (R.M.); (A.C.); (M.S.); (R.M.); (A.T.)
- Nutramed S.c.a.r.l, Complesso Ninì Barbieri, Roccelletta di Borgia, 88021 Catanzaro, Italy
| | - Cristina Carresi
- IRC-FSH Department of Health Sciences, University “Magna Græcia” of Catanzaro, Campus Universitario di Germaneto, 88100 Catanzaro, Italy; (J.M.); (C.C.); (M.G.); (V.M.); (F.S.); (A.R.C.); (L.G.); (S.N.); (M.S.); (F.B.); (S.R.); (M.C.Z.); (R.M.); (A.C.); (M.S.); (R.M.); (A.T.)
- Nutramed S.c.a.r.l, Complesso Ninì Barbieri, Roccelletta di Borgia, 88021 Catanzaro, Italy
| | - Micaela Gliozzi
- IRC-FSH Department of Health Sciences, University “Magna Græcia” of Catanzaro, Campus Universitario di Germaneto, 88100 Catanzaro, Italy; (J.M.); (C.C.); (M.G.); (V.M.); (F.S.); (A.R.C.); (L.G.); (S.N.); (M.S.); (F.B.); (S.R.); (M.C.Z.); (R.M.); (A.C.); (M.S.); (R.M.); (A.T.)
- Nutramed S.c.a.r.l, Complesso Ninì Barbieri, Roccelletta di Borgia, 88021 Catanzaro, Italy
| | - Vincenzo Musolino
- IRC-FSH Department of Health Sciences, University “Magna Græcia” of Catanzaro, Campus Universitario di Germaneto, 88100 Catanzaro, Italy; (J.M.); (C.C.); (M.G.); (V.M.); (F.S.); (A.R.C.); (L.G.); (S.N.); (M.S.); (F.B.); (S.R.); (M.C.Z.); (R.M.); (A.C.); (M.S.); (R.M.); (A.T.)
- Nutramed S.c.a.r.l, Complesso Ninì Barbieri, Roccelletta di Borgia, 88021 Catanzaro, Italy
| | - Federica Scarano
- IRC-FSH Department of Health Sciences, University “Magna Græcia” of Catanzaro, Campus Universitario di Germaneto, 88100 Catanzaro, Italy; (J.M.); (C.C.); (M.G.); (V.M.); (F.S.); (A.R.C.); (L.G.); (S.N.); (M.S.); (F.B.); (S.R.); (M.C.Z.); (R.M.); (A.C.); (M.S.); (R.M.); (A.T.)
- Nutramed S.c.a.r.l, Complesso Ninì Barbieri, Roccelletta di Borgia, 88021 Catanzaro, Italy
| | - Anna Rita Coppoletta
- IRC-FSH Department of Health Sciences, University “Magna Græcia” of Catanzaro, Campus Universitario di Germaneto, 88100 Catanzaro, Italy; (J.M.); (C.C.); (M.G.); (V.M.); (F.S.); (A.R.C.); (L.G.); (S.N.); (M.S.); (F.B.); (S.R.); (M.C.Z.); (R.M.); (A.C.); (M.S.); (R.M.); (A.T.)
- Nutramed S.c.a.r.l, Complesso Ninì Barbieri, Roccelletta di Borgia, 88021 Catanzaro, Italy
| | - Lorenza Guarnieri
- IRC-FSH Department of Health Sciences, University “Magna Græcia” of Catanzaro, Campus Universitario di Germaneto, 88100 Catanzaro, Italy; (J.M.); (C.C.); (M.G.); (V.M.); (F.S.); (A.R.C.); (L.G.); (S.N.); (M.S.); (F.B.); (S.R.); (M.C.Z.); (R.M.); (A.C.); (M.S.); (R.M.); (A.T.)
- Nutramed S.c.a.r.l, Complesso Ninì Barbieri, Roccelletta di Borgia, 88021 Catanzaro, Italy
| | - Saverio Nucera
- IRC-FSH Department of Health Sciences, University “Magna Græcia” of Catanzaro, Campus Universitario di Germaneto, 88100 Catanzaro, Italy; (J.M.); (C.C.); (M.G.); (V.M.); (F.S.); (A.R.C.); (L.G.); (S.N.); (M.S.); (F.B.); (S.R.); (M.C.Z.); (R.M.); (A.C.); (M.S.); (R.M.); (A.T.)
- Nutramed S.c.a.r.l, Complesso Ninì Barbieri, Roccelletta di Borgia, 88021 Catanzaro, Italy
| | - Miriam Scicchitano
- IRC-FSH Department of Health Sciences, University “Magna Græcia” of Catanzaro, Campus Universitario di Germaneto, 88100 Catanzaro, Italy; (J.M.); (C.C.); (M.G.); (V.M.); (F.S.); (A.R.C.); (L.G.); (S.N.); (M.S.); (F.B.); (S.R.); (M.C.Z.); (R.M.); (A.C.); (M.S.); (R.M.); (A.T.)
- Nutramed S.c.a.r.l, Complesso Ninì Barbieri, Roccelletta di Borgia, 88021 Catanzaro, Italy
| | - Francesca Bosco
- IRC-FSH Department of Health Sciences, University “Magna Græcia” of Catanzaro, Campus Universitario di Germaneto, 88100 Catanzaro, Italy; (J.M.); (C.C.); (M.G.); (V.M.); (F.S.); (A.R.C.); (L.G.); (S.N.); (M.S.); (F.B.); (S.R.); (M.C.Z.); (R.M.); (A.C.); (M.S.); (R.M.); (A.T.)
- Nutramed S.c.a.r.l, Complesso Ninì Barbieri, Roccelletta di Borgia, 88021 Catanzaro, Italy
| | - Stefano Ruga
- IRC-FSH Department of Health Sciences, University “Magna Græcia” of Catanzaro, Campus Universitario di Germaneto, 88100 Catanzaro, Italy; (J.M.); (C.C.); (M.G.); (V.M.); (F.S.); (A.R.C.); (L.G.); (S.N.); (M.S.); (F.B.); (S.R.); (M.C.Z.); (R.M.); (A.C.); (M.S.); (R.M.); (A.T.)
- Nutramed S.c.a.r.l, Complesso Ninì Barbieri, Roccelletta di Borgia, 88021 Catanzaro, Italy
| | - Maria Caterina Zito
- IRC-FSH Department of Health Sciences, University “Magna Græcia” of Catanzaro, Campus Universitario di Germaneto, 88100 Catanzaro, Italy; (J.M.); (C.C.); (M.G.); (V.M.); (F.S.); (A.R.C.); (L.G.); (S.N.); (M.S.); (F.B.); (S.R.); (M.C.Z.); (R.M.); (A.C.); (M.S.); (R.M.); (A.T.)
- Nutramed S.c.a.r.l, Complesso Ninì Barbieri, Roccelletta di Borgia, 88021 Catanzaro, Italy
| | - Roberta Macri
- IRC-FSH Department of Health Sciences, University “Magna Græcia” of Catanzaro, Campus Universitario di Germaneto, 88100 Catanzaro, Italy; (J.M.); (C.C.); (M.G.); (V.M.); (F.S.); (A.R.C.); (L.G.); (S.N.); (M.S.); (F.B.); (S.R.); (M.C.Z.); (R.M.); (A.C.); (M.S.); (R.M.); (A.T.)
- Nutramed S.c.a.r.l, Complesso Ninì Barbieri, Roccelletta di Borgia, 88021 Catanzaro, Italy
| | - Antonio Cardamone
- IRC-FSH Department of Health Sciences, University “Magna Græcia” of Catanzaro, Campus Universitario di Germaneto, 88100 Catanzaro, Italy; (J.M.); (C.C.); (M.G.); (V.M.); (F.S.); (A.R.C.); (L.G.); (S.N.); (M.S.); (F.B.); (S.R.); (M.C.Z.); (R.M.); (A.C.); (M.S.); (R.M.); (A.T.)
- Nutramed S.c.a.r.l, Complesso Ninì Barbieri, Roccelletta di Borgia, 88021 Catanzaro, Italy
| | - Maria Serra
- IRC-FSH Department of Health Sciences, University “Magna Græcia” of Catanzaro, Campus Universitario di Germaneto, 88100 Catanzaro, Italy; (J.M.); (C.C.); (M.G.); (V.M.); (F.S.); (A.R.C.); (L.G.); (S.N.); (M.S.); (F.B.); (S.R.); (M.C.Z.); (R.M.); (A.C.); (M.S.); (R.M.); (A.T.)
- Nutramed S.c.a.r.l, Complesso Ninì Barbieri, Roccelletta di Borgia, 88021 Catanzaro, Italy
| | - Rocco Mollace
- IRC-FSH Department of Health Sciences, University “Magna Græcia” of Catanzaro, Campus Universitario di Germaneto, 88100 Catanzaro, Italy; (J.M.); (C.C.); (M.G.); (V.M.); (F.S.); (A.R.C.); (L.G.); (S.N.); (M.S.); (F.B.); (S.R.); (M.C.Z.); (R.M.); (A.C.); (M.S.); (R.M.); (A.T.)
- IRCCS San Raffaele, Via di Valcannuta 247, 00133 Rome, Italy
| | - Annamaria Tavernese
- IRC-FSH Department of Health Sciences, University “Magna Græcia” of Catanzaro, Campus Universitario di Germaneto, 88100 Catanzaro, Italy; (J.M.); (C.C.); (M.G.); (V.M.); (F.S.); (A.R.C.); (L.G.); (S.N.); (M.S.); (F.B.); (S.R.); (M.C.Z.); (R.M.); (A.C.); (M.S.); (R.M.); (A.T.)
- Nutramed S.c.a.r.l, Complesso Ninì Barbieri, Roccelletta di Borgia, 88021 Catanzaro, Italy
| | - Vincenzo Mollace
- IRC-FSH Department of Health Sciences, University “Magna Græcia” of Catanzaro, Campus Universitario di Germaneto, 88100 Catanzaro, Italy; (J.M.); (C.C.); (M.G.); (V.M.); (F.S.); (A.R.C.); (L.G.); (S.N.); (M.S.); (F.B.); (S.R.); (M.C.Z.); (R.M.); (A.C.); (M.S.); (R.M.); (A.T.)
- Nutramed S.c.a.r.l, Complesso Ninì Barbieri, Roccelletta di Borgia, 88021 Catanzaro, Italy
- IRCCS San Raffaele, Via di Valcannuta 247, 00133 Rome, Italy
- Correspondence: ; Tel.: +39-327-475-8006
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Watanabe D, Wada M. Orthograde signal of dihydropyridine receptor increases Ca 2+ leakage after repeated contractions in rat fast-twitch muscles in vivo. Am J Physiol Cell Physiol 2021; 320:C806-C821. [PMID: 33596151 DOI: 10.1152/ajpcell.00364.2020] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Accepted: 02/10/2021] [Indexed: 11/22/2022]
Abstract
The purpose of this study was to investigate the mechanism underlying sarcoplasmic reticulum (SR) Ca2+ leakage after in vivo contractions. Rat gastrocnemius muscles were electrically stimulated in vivo, and then mechanically skinned fibers and SR microsomes were prepared from the muscles excised 30 min after repeated high-intensity contractions. The mechanically skinned fibers maintained the interaction between dihydropyridine receptors (DHPRs) and ryanodine receptors (RyRs), whereas the SR microsomes did not. Interestingly, skinned fibers from the stimulated muscles showed increased SR Ca2+ leakage, whereas Ca2+ leakage decreased in SR microsomes from the stimulated muscles. To enhance the orthograde signal of DHPRs, SR Ca2+ leakage in the skinned fiber was measured 1) under a continuously depolarized condition and 2) in the presence of nifedipine. As a result, in either of the two conditions, SR Ca2+ leakage in the rested fibers reached a level similar to that in the stimulated fibers. Furthermore, the increased SR Ca2+ leakage from the stimulated fibers was alleviated by treatment with 1 mM tetracaine (Tet) but not by treatment with 3 mM free Mg2+ (3 Mg). Tet exerted a greater inhibitory effect on the DHPR signal to RyR than 3 Mg, although their inhibitory effects on RyR were almost similar. These results suggest that the increased Ca2+ leakage after muscle contractions is mainly caused by the orthograde signal of DHPRs to RyRs.
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Affiliation(s)
- Daiki Watanabe
- Graduate School of Humanities and Social Sciences, Hiroshima University, Hiroshima, Japan
| | - Masanobu Wada
- Graduate School of Humanities and Social Sciences, Hiroshima University, Hiroshima, Japan
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Laufenberg LJ, Crowell KT, Lang CH. Alcohol Acutely Antagonizes Refeeding-Induced Alterations in the Rag GTPase-Ragulator Complex in Skeletal Muscle. Nutrients 2021; 13:1236. [PMID: 33918604 PMCID: PMC8070399 DOI: 10.3390/nu13041236] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Revised: 03/17/2021] [Accepted: 04/02/2021] [Indexed: 02/07/2023] Open
Abstract
The Ragulator protein complex is critical for directing the Rag GTPase proteins and mTORC1 to the lysosome membrane mediating amino acid-stimulated protein synthesis. As there is a lack of evidence on alcohol's effect on the Rag-Ragulator complex as a possible mechanism for the development of alcoholic skeletal muscle wasting, the aim of our study was to examine alterations in various protein-protein complexes in the Rag-Ragulator pathway produced acutely by feeding and how these are altered by alcohol under in vivo conditions. Mice (C57Bl/6; adult males) were fasted, and then provided rodent chow for 30 min ("refed") or remained food-deprived ("fasted"). Mice subsequently received ethanol (3 g/kg ethanol) or saline intraperitoneally, and hindlimb muscles were collected 1 h thereafter for analysis. Refeeding-induced increases in myofibrillar and sarcoplasmic protein synthesis, and mTOR and S6K1 phosphorylation, were prevented by alcohol. This inhibition was not associated with a differential rise in the intracellular leucine concentration or plasma leucine or insulin levels. Alcohol increased the amount of the Sestrin1•GATOR2 complex in the fasted state and prevented the refeeding-induced decrease in Sestrin1•GATOR2 seen in control mice. Alcohol antagonized the increase in the RagA/C•Raptor complex formation seen in the refed state. Alcohol antagonized the increase in Raptor with immunoprecipitated LAMPTOR1 (part of the Ragulator complex) after refeeding and decreased the association of RagC with LAMPTOR1. Finally, alcohol increased the association of the V1 domain of v-ATPase with LAMPTOR1 and prevented the refeeding-induced decrease in v-ATPase V1 with LAMPTOR1. Overall, these data demonstrate that acute alcohol intake disrupts multiple protein-protein complexes within the Rag-Ragulator complex, which are associated with and consistent with the concomitant decline in nutrient-stimulated muscle protein synthesis under in vivo conditions.
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Affiliation(s)
- Lacee J. Laufenberg
- Department of Surgery, Penn State College of Medicine, Hershey, PA 17033, USA; (L.J.L.); (K.T.C.)
| | - Kristen T. Crowell
- Department of Surgery, Penn State College of Medicine, Hershey, PA 17033, USA; (L.J.L.); (K.T.C.)
- Beth Israel Deaconess Medical Center, Department of Surgery, Boston, MA 02215, USA
| | - Charles H. Lang
- Department of Surgery, Penn State College of Medicine, Hershey, PA 17033, USA; (L.J.L.); (K.T.C.)
- Department of Cellular & Molecular Physiology, Penn State College of Medicine, Hershey, PA 17033, USA
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7
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Mekies LN, Regev D, Eisen B, Fernandez‐Gracia J, Baskin P, Ben Jehuda R, Shulman R, Reiter I, Palty R, Arad M, Gottlieb E, Binah O. Depressed β-adrenergic inotropic responsiveness and intracellular calcium handling abnormalities in Duchenne Muscular Dystrophy patients' induced pluripotent stem cell-derived cardiomyocytes. J Cell Mol Med 2021; 25:3922-3934. [PMID: 33619882 PMCID: PMC8051742 DOI: 10.1111/jcmm.16341] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Revised: 01/05/2021] [Accepted: 01/14/2021] [Indexed: 12/20/2022] Open
Abstract
Duchenne muscular dystrophy (DMD), caused by mutations in the dystrophin gene, is an X-linked disease affecting male and rarely adult heterozygous females, resulting in death by the late 20s to early 30s. Previous studies reported depressed left ventricular function in DMD patients which may result from deranged intracellular Ca2+ -handling. To decipher the mechanism(s) underlying the depressed LV function, we tested the hypothesis that iPSC-CMs generated from DMD patients feature blunted positive inotropic response to β-adrenergic stimulation. To test the hypothesis, [Ca2+ ]i transients and contractions were recorded from healthy and DMD-CMs. While in healthy CMs (HC) isoproterenol caused a prominent positive inotropic effect, DMD-CMs displayed a blunted inotropic response. Next, we tested the functionality of the sarcoplasmic reticulum (SR) by measuring caffeine-induced Ca2+ release. In contrast to HC, DMD-CMs exhibited reduced caffeine-induced Ca2+ signal amplitude and recovery time. In support of the depleted SR Ca2+ stores hypothesis, in DMD-CMs the negative inotropic effects of ryanodine and cyclopiazonic acid were smaller than in HC. RNA-seq analyses demonstrated that in DMD CMs the RNA-expression levels of specific subunits of the L-type calcium channel, the β1-adrenergic receptor (ADRβ1) and adenylate cyclase were down-regulated by 3.5-, 2.8- and 3-fold, respectively, which collectively contribute to the depressed β-adrenergic responsiveness.
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MESH Headings
- Adrenergic Agents/pharmacology
- Adult
- Calcium/metabolism
- Calcium Channels, L-Type/genetics
- Calcium Channels, L-Type/metabolism
- Cell Differentiation
- Female
- Gene Expression Regulation
- Humans
- Induced Pluripotent Stem Cells/drug effects
- Induced Pluripotent Stem Cells/metabolism
- Induced Pluripotent Stem Cells/pathology
- Male
- Middle Aged
- Muscular Dystrophy, Duchenne/drug therapy
- Muscular Dystrophy, Duchenne/metabolism
- Muscular Dystrophy, Duchenne/pathology
- Myocardial Contraction
- Myocytes, Cardiac/drug effects
- Myocytes, Cardiac/metabolism
- Myocytes, Cardiac/pathology
- RNA-Seq
- Receptors, Adrenergic, beta-1/genetics
- Receptors, Adrenergic, beta-1/metabolism
- Sarcoplasmic Reticulum/drug effects
- Sarcoplasmic Reticulum/metabolism
- Sarcoplasmic Reticulum/pathology
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Affiliation(s)
- Lucy N. Mekies
- Department of PhysiologyBiophysics and Systems BiologyRappaport Faculty of MedicineTechnion – Israel Institute of TechnologyHaifaIsrael
| | - Danielle Regev
- Department of PhysiologyBiophysics and Systems BiologyRappaport Faculty of MedicineTechnion – Israel Institute of TechnologyHaifaIsrael
| | - Binyamin Eisen
- Department of PhysiologyBiophysics and Systems BiologyRappaport Faculty of MedicineTechnion – Israel Institute of TechnologyHaifaIsrael
| | - Jonatan Fernandez‐Gracia
- Department of Cell Biology and Cancer ScienceRappaport Faculty of MedicineTechnion – Israel Institute of TechnologyHaifaIsrael
| | - Polina Baskin
- Department of PhysiologyBiophysics and Systems BiologyRappaport Faculty of MedicineTechnion – Israel Institute of TechnologyHaifaIsrael
| | - Ronen Ben Jehuda
- Department of PhysiologyBiophysics and Systems BiologyRappaport Faculty of MedicineTechnion – Israel Institute of TechnologyHaifaIsrael
- Faculty of Biotechnology and Food EngineeringTechnion – Israel Institute of TechnologyHaifaIsrael
| | - Rita Shulman
- Department of PhysiologyBiophysics and Systems BiologyRappaport Faculty of MedicineTechnion – Israel Institute of TechnologyHaifaIsrael
| | - Irina Reiter
- Department of PhysiologyBiophysics and Systems BiologyRappaport Faculty of MedicineTechnion – Israel Institute of TechnologyHaifaIsrael
| | - Raz Palty
- Department of BiochemistryRappaport Faculty of MedicineTechnion – Israel Institute of TechnologyHaifaIsrael
| | - Michael Arad
- Leviev Heart CenterSheba Medical CenterRamat GanIsrael
- Sackler Faculty of MedicineTel Aviv UniversityTel AvivIsrael
| | - Eyal Gottlieb
- Department of Cell Biology and Cancer ScienceRappaport Faculty of MedicineTechnion – Israel Institute of TechnologyHaifaIsrael
| | - Ofer Binah
- Department of PhysiologyBiophysics and Systems BiologyRappaport Faculty of MedicineTechnion – Israel Institute of TechnologyHaifaIsrael
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8
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Zhang Y, Qi Y, Li JJ, He WJ, Gao XH, Zhang Y, Sun X, Tong J, Zhang J, Deng XL, Du XJ, Xie W. Stretch-induced sarcoplasmic reticulum calcium leak is causatively associated with atrial fibrillation in pressure-overloaded hearts. Cardiovasc Res 2021; 117:1091-1102. [PMID: 32531044 DOI: 10.1093/cvr/cvaa163] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Revised: 01/06/2020] [Accepted: 06/05/2020] [Indexed: 12/21/2022] Open
Abstract
AIMS Despite numerous reports documenting an important role of hypertension in the development of atrial fibrillation (AF), the detailed mechanism underlying the pathological process remains incompletely understood. Here, we aim to test the hypothesis that diastolic sarcoplasmic reticulum (SR) Ca2+ leak in atrial myocytes, induced by mechanical stretch due to elevated pressure in the left atrium (LA), plays an essential role in the AF development in pressure-overloaded hearts. METHODS AND RESULTS Isolated mouse atrial myocytes subjected to acute axial stretch displayed an immediate elevation of SR Ca2+ leak. Using a mouse model of transverse aortic constriction (TAC), the relation between stretch, SR Ca2+ leak, and AF susceptibility was further tested. At 36 h post-TAC, SR Ca2+ leak in cardiomyocytes from the LA (with haemodynamic stress), but not right atrium (without haemodynamic stress), significantly increased, which was further elevated at 4 weeks post-TAC. Accordingly, AF susceptibility to atrial burst pacing in the 4-week TAC mice were also significantly increased, which was unaffected by inhibition of atrial fibrosis or inflammation via deletion of galectin-3. Western blotting revealed that type 2 ryanodine receptor (RyR2) in left atrial myocytes of TAC mice was oxidized due to activation and up-regulation of Nox2 and Nox4. Direct rescue of dysfunctional RyR2 with dantrolene or rycal S107 reduced diastolic SR Ca2+ leak in left atrial myocytes and prevented atrial burst pacing stimulated AF. CONCLUSION Our study demonstrated for the first time the increased SR Ca2+ leak mediated by enhanced oxidative stress in left atrial myocytes that is causatively associated with higher AF susceptibility in pressure-overloaded hearts.
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Affiliation(s)
- Yi Zhang
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an, Shaanxi, China
| | - Ying Qi
- The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi'an Jiaotong University, No. 28 West Xianning Road, Xi'an, Shaanxi 710049, China
| | - Jing-Jing Li
- The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi'an Jiaotong University, No. 28 West Xianning Road, Xi'an, Shaanxi 710049, China
| | - Wen-Jin He
- The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi'an Jiaotong University, No. 28 West Xianning Road, Xi'an, Shaanxi 710049, China
| | - Xiao-Hang Gao
- The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi'an Jiaotong University, No. 28 West Xianning Road, Xi'an, Shaanxi 710049, China
| | - Yu Zhang
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an, Shaanxi, China
| | - Xia Sun
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an, Shaanxi, China
| | - Jie Tong
- The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi'an Jiaotong University, No. 28 West Xianning Road, Xi'an, Shaanxi 710049, China
| | - Jianbao Zhang
- The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi'an Jiaotong University, No. 28 West Xianning Road, Xi'an, Shaanxi 710049, China
| | - Xiu-Ling Deng
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an, Shaanxi, China
- Cardiovascular Research Centre, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an, Shaanxi, China
| | - Xiao-Jun Du
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an, Shaanxi, China
| | - Wenjun Xie
- The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi'an Jiaotong University, No. 28 West Xianning Road, Xi'an, Shaanxi 710049, China
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9
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Abstract
RATIONALE The class Ic antiarrhythmic drug flecainide prevents ventricular tachyarrhythmia in patients with catecholaminergic polymorphic ventricular tachycardia (CPVT), a disease caused by hyperactive RyR2 (cardiac ryanodine receptor) mediated calcium (Ca) release. Although flecainide inhibits single RyR2 channels in vitro, reports have claimed that RyR2 inhibition by flecainide is not relevant for its mechanism of antiarrhythmic action and concluded that sodium channel block alone is responsible for flecainide's efficacy in CPVT. OBJECTIVE To determine whether RyR2 block independently contributes to flecainide's efficacy for suppressing spontaneous sarcoplasmic reticulum Ca release and for preventing ventricular tachycardia in vivo. METHODS AND RESULTS We synthesized N-methylated flecainide analogues (QX-flecainide and N-methyl flecainide) and showed that N-methylation reduces flecainide's inhibitory potency on RyR2 channels incorporated into artificial lipid bilayers. N-methylation did not alter flecainide's inhibitory activity on human cardiac sodium channels expressed in HEK293T cells. Antiarrhythmic efficacy was tested utilizing a Casq2 (cardiac calsequestrin) knockout (Casq2-/-) CPVT mouse model. In membrane-permeabilized Casq2-/- cardiomyocytes-lacking intact sarcolemma and devoid of sodium channel contribution-flecainide, but not its analogues, suppressed RyR2-mediated Ca release at clinically relevant concentrations. In voltage-clamped, intact Casq2-/- cardiomyocytes pretreated with tetrodotoxin to inhibit sodium channels and isolate the effect of flecainide on RyR2, flecainide significantly reduced the frequency of spontaneous sarcoplasmic reticulum Ca release, while QX-flecainide and N-methyl flecainide did not. In vivo, flecainide effectively suppressed catecholamine-induced ventricular tachyarrhythmias in Casq2-/- mice, whereas N-methyl flecainide had no significant effect on arrhythmia burden, despite comparable sodium channel block. CONCLUSIONS Flecainide remains an effective inhibitor of RyR2-mediated arrhythmogenic Ca release even when cardiac sodium channels are blocked. In mice with CPVT, sodium channel block alone did not prevent ventricular tachycardia. Hence, RyR2 channel inhibition likely constitutes the principal mechanism of antiarrhythmic action of flecainide in CPVT.
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Affiliation(s)
- Dmytro O Kryshtal
- Vanderbilt Center for Arrhythmia Research and Therapeutics, Division of Clinical Pharmacology, Vanderbilt University Medical Center, Nashville, TN (D.O.K., D.J.B., C.L.E., B.C.K.)
| | - Daniel J Blackwell
- Vanderbilt Center for Arrhythmia Research and Therapeutics, Division of Clinical Pharmacology, Vanderbilt University Medical Center, Nashville, TN (D.O.K., D.J.B., C.L.E., B.C.K.)
| | - Christian L Egly
- Vanderbilt Center for Arrhythmia Research and Therapeutics, Division of Clinical Pharmacology, Vanderbilt University Medical Center, Nashville, TN (D.O.K., D.J.B., C.L.E., B.C.K.)
| | - Abigail N Smith
- Department of Chemistry, Vanderbilt Institute of Chemical Biology, Vanderbilt University, Nashville, TN (A.N.S., S.M.B., J.N.J.)
| | - Suzanne M Batiste
- Department of Chemistry, Vanderbilt Institute of Chemical Biology, Vanderbilt University, Nashville, TN (A.N.S., S.M.B., J.N.J.)
| | - Jeffrey N Johnston
- Department of Chemistry, Vanderbilt Institute of Chemical Biology, Vanderbilt University, Nashville, TN (A.N.S., S.M.B., J.N.J.)
| | - Derek R Laver
- School of Biomedical Sciences and Pharmacy, University of Newcastle and Hunter Medical Research Institute, Callaghan, NSW, Australia (D.R.L.)
| | - Bjorn C Knollmann
- Vanderbilt Center for Arrhythmia Research and Therapeutics, Division of Clinical Pharmacology, Vanderbilt University Medical Center, Nashville, TN (D.O.K., D.J.B., C.L.E., B.C.K.)
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10
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Liu SX, Matthews HR, Huang CLH. Sarcoplasmic reticular Ca 2+-ATPase inhibition paradoxically upregulates murine skeletal muscle Na v1.4 function. Sci Rep 2021; 11:2846. [PMID: 33531589 PMCID: PMC7854688 DOI: 10.1038/s41598-021-82493-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Accepted: 01/11/2021] [Indexed: 12/18/2022] Open
Abstract
Skeletal muscle Na+ channels possess Ca2+- and calmodulin-binding sites implicated in Nav1.4 current (INa) downregulation following ryanodine receptor (RyR1) activation produced by exchange protein directly activated by cyclic AMP or caffeine challenge, effects abrogated by the RyR1-antagonist dantrolene which itself increased INa. These findings were attributed to actions of consequently altered cytosolic Ca2+, [Ca2+]i, on Nav1.4. We extend the latter hypothesis employing cyclopiazonic acid (CPA) challenge, which similarly increases [Ca2+]i, but through contrastingly inhibiting sarcoplasmic reticular (SR) Ca2+-ATPase. Loose patch clamping determined Na+ current (INa) families in intact native murine gastrocnemius skeletal myocytes, minimising artefactual [Ca2+]i perturbations. A bespoke flow system permitted continuous INa comparisons through graded depolarizing steps in identical stable membrane patches before and following solution change. In contrast to the previous studies modifying RyR1 activity, and imposing control solution changes, CPA (0.1 and 1 µM) produced persistent increases in INa within 1-4 min of introduction. CPA pre-treatment additionally abrogated previously reported reductions in INa produced by 0.5 mM caffeine. Plots of peak current against voltage excursion demonstrated that 1 µM CPA increased maximum INa by ~ 30%. It only slightly decreased half-maximal activating voltages (V0.5) and steepness factors (k), by 2 mV and 0.7, in contrast to the V0.5 and k shifts reported with direct RyR1 modification. These paradoxical findings complement previously reported downregulatory effects on Nav1.4 of RyR1-agonist mediated increases in bulk cytosolic [Ca2+]. They implicate possible local tubule-sarcoplasmic triadic domains containing reduced [Ca2+]TSR in the observed upregulation of Nav1.4 function following CPA-induced SR Ca2+ depletion.
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Affiliation(s)
- Sean X Liu
- Physiological Laboratory, University of Cambridge, Cambridge, CB2 3EG, UK
| | - Hugh R Matthews
- Physiological Laboratory, University of Cambridge, Cambridge, CB2 3EG, UK
| | - Christopher L-H Huang
- Physiological Laboratory, University of Cambridge, Cambridge, CB2 3EG, UK.
- Department of Biochemistry, University of Cambridge, Cambridge, CB2 1QW, UK.
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11
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Laasmaa M, Branovets J, Barsunova K, Karro N, Lygate CA, Birkedal R, Vendelin M. Altered calcium handling in cardiomyocytes from arginine-glycine amidinotransferase-knockout mice is rescued by creatine. Am J Physiol Heart Circ Physiol 2021; 320:H805-H825. [PMID: 33275525 DOI: 10.1152/ajpheart.00300.2020] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Revised: 10/30/2020] [Accepted: 11/23/2020] [Indexed: 01/14/2023]
Abstract
The creatine kinase system facilitates energy transfer between mitochondria and the major ATPases in the heart. Creatine-deficient mice, which lack arginine-glycine amidinotransferase (AGAT) to synthesize creatine and homoarginine, exhibit reduced cardiac contractility. We studied how the absence of a functional CK system influences calcium handling in isolated cardiomyocytes from AGAT-knockouts and wild-type littermates as well as in AGAT-knockout mice receiving lifelong creatine supplementation via the food. Using a combination of whole cell patch clamp and fluorescence microscopy, we demonstrate that the L-type calcium channel (LTCC) current amplitude and voltage range of activation were significantly lower in AGAT-knockout compared with wild-type littermates. Additionally, the inactivation of LTCC and the calcium transient decay were significantly slower. According to our modeling results, these changes can be reproduced by reducing three parameters in knockout mice when compared with wild-type: LTCC conductance, the exchange constant of Ca2+ transfer between subspace and cytosol, and SERCA activity. Because tissue expression of LTCC and SERCA protein were not significantly different between genotypes, this suggests the involvement of posttranslational regulatory mechanisms or structural reorganization. The AGAT-knockout phenotype of calcium handling was fully reversed by dietary creatine supplementation throughout life. Our results indicate reduced calcium cycling in cardiomyocytes from AGAT-knockouts and suggest that the creatine kinase system is important for the development of calcium handling in the heart.NEW & NOTEWORTHY Creatine-deficient mice lacking arginine-glycine amidinotransferase exhibit compromised cardiac function. Here, we show that this is at least partially due to an overall slowing of calcium dynamics. Calcium influx into the cytosol via the L-type calcium current (LTCC) is diminished, and the rate of the sarcoendoplasmic reticulum calcium ATPase (SERCA) pumping calcium back into the sarcoplasmic reticulum is slower. The expression of LTCC and SERCA did not change, suggesting that the changes are regulatory.
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Affiliation(s)
- Martin Laasmaa
- Laboratory of Systems Biology, Department of Cybernetics, School of Science, Tallinn University of Technology, Tallinn, Estonia
| | - Jelena Branovets
- Laboratory of Systems Biology, Department of Cybernetics, School of Science, Tallinn University of Technology, Tallinn, Estonia
| | - Karina Barsunova
- Laboratory of Systems Biology, Department of Cybernetics, School of Science, Tallinn University of Technology, Tallinn, Estonia
| | - Niina Karro
- Laboratory of Systems Biology, Department of Cybernetics, School of Science, Tallinn University of Technology, Tallinn, Estonia
| | - Craig A Lygate
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine, and the British Heart Foundation Centre of Research Excellence, University of Oxford, Tallinn, United Kingdom
| | - Rikke Birkedal
- Laboratory of Systems Biology, Department of Cybernetics, School of Science, Tallinn University of Technology, Tallinn, Estonia
| | - Marko Vendelin
- Laboratory of Systems Biology, Department of Cybernetics, School of Science, Tallinn University of Technology, Tallinn, Estonia
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12
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Montiel-Jaen MG, Monsalvo-Villegas A, Ávila G. Modulating ALDH2 reveals a differential dependence on ROS for hypertrophy and SR Ca 2+ release in aldosterone-treated cardiac myocytes. Biochem Biophys Res Commun 2021; 536:7-13. [PMID: 33360016 DOI: 10.1016/j.bbrc.2020.12.049] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Accepted: 12/16/2020] [Indexed: 11/17/2022]
Abstract
Growing evidence links high aldosterone levels with atrial fibrillation and other heart diseases. Here, we have investigated the functional consequences of culturing adult rat atrial myocytes with aldosterone, at the level of cell size, homeostasis of Ca2+, reactive oxygen species (ROS), and nitrogen oxide (NO). The protein levels of NO synthase (NOS), aldehyde dehydrogenase 2 (ALDH2), NADPH oxidase (NOX), and Na+-Ca2+ exchanger (NCX) were also studied. Aldosterone did not alter the expression of these proteins, except for the NCX, which was enhanced by nearly 100%. Additionally, the hormone inhibited and stimulated, respectively, the production of NO and ROS (the effect on ROS appeared after 24 h of treatment and reached a maximum by 4-6 days, with an EC50 of 1.2 nM). These changes in reactive species generation were blunted by tetrahydrobiopterin (BH4, a NOS cofactor), suggesting the involvement of an uncoupled NOS. An activator (Alda-1) and an inhibitor (daidzin) of ALDH2 were used, to determine if this enzyme activity is related to aldosterone effects, through possible modulation of ROS. Aldosterone produced a ∼10% increase in cell size and, remarkably, this hypertrophic effect, along with the corresponding changes in ROS and NO, were all mimicked by daidzin and prevented by Alda-1. Something different happened with SR Ca2+ release. Aldosterone increased both the magnitude of Ca2+ transients and the incidence of spontaneous Ca2+ oscillations, but these actions were not reproduced by daidzin. Moreover, rather than being prevented, they were further promoted by Alda-1, which also increased the rate of SR Ca2+ reuptake. These results suggest that NOS and ALDH2 may prevent some adverse consequences of aldosteronism (in the case of ALDH2, at the expense of exacerbating SR Ca2+ release). Our data also suggest a hierarchical model in which aldosterone promotes: SR Ca2+ release, then ROS production, and finally hypertrophy.
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13
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Pabel S, Reetz F, Dybkova N, Shomroni O, Salinas G, Mustroph J, Hammer KP, Hasenfuss G, Hamdani N, Maier LS, Streckfuss-Bömeke K, Sossalla S. Long-term effects of empagliflozin on excitation-contraction-coupling in human induced pluripotent stem cell cardiomyocytes. J Mol Med (Berl) 2020; 98:1689-1700. [PMID: 33034709 PMCID: PMC7679329 DOI: 10.1007/s00109-020-01989-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Revised: 09/11/2020] [Accepted: 10/01/2020] [Indexed: 12/18/2022]
Abstract
Abstract The SGLT2 inhibitor empagliflozin improved cardiovascular outcomes in patients with diabetes. As the cardiac mechanisms remain elusive, we investigated the long-term effects (up to 2 months) of empagliflozin on excitation-contraction (EC)-coupling in human cardiomyocytes derived from induced pluripotent stem cells (iPSC-CM) in a blinded manner. IPSC from 3 donors, differentiated into pure iPSC-CM (4 differentiations), were treated with a clinically relevant concentration of empagliflozin (0.5 μmol/l) or vehicle control. Treatment, data acquisition, and analysis were conducted externally blinded. Epifluorescence microscopy measurements in iPSC-CM showed that empagliflozin has neutral effects on Ca2+ transient amplitude, diastolic Ca2+ levels, Ca2+ transient kinetics, or sarcoplasmic Ca2+ load after 2 weeks or 8 weeks of treatment. Confocal microscopy determining possible effects on proarrhythmogenic diastolic Ca2+ release events showed that in iPSC-CM, Ca2+ spark frequency and leak was not altered after chronic treatment with empagliflozin. Finally, in patch-clamp experiments, empagliflozin did not change action potential duration, amplitude, or resting membrane potential compared with vehicle control after long-term treatment. Next-generation RNA sequencing (NGS) and mapped transcriptome profiles of iPSC-CMs untreated and treated with empagliflozin for 8 weeks showed no differentially expressed EC-coupling genes. In line with NGS data, Western blots indicate that empagliflozin has negligible effects on key EC-coupling proteins. In this blinded study, direct treatment of iPSC-CM with empagliflozin for a clinically relevant duration of 2 months did not influence cardiomyocyte EC-coupling and electrophysiology. Therefore, it is likely that other mechanisms independent of cardiomyocyte EC-coupling are responsible for the beneficial treatment effect of empagliflozin. Key messages This blinded study investigated the clinically relevant long-term effects (up to 2 months) of empagliflozin on cardiomyocyte excitation-contraction (EC)-coupling. Human cardiomyocytes derived from induced pluripotent stem cells (iPSC-CM) were used to study a human model including a high repetition number of experiments. Empagliflozin has neutral effects on cardiomyocyte Ca2+ transients, sarcoplasmic Ca2+ load, and diastolic sarcoplasmic Ca2+ leak. In patch-clamp experiments, empagliflozin did not change the action potential. Next-generation RNA sequencing, mapped transcriptome profiles, and Western blots of iPSC-CM untreated and treated with empagliflozin showed no differentially expressed EC-coupling candidates.
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Affiliation(s)
- Steffen Pabel
- Department of Internal Medicine II, University Medical Center Regensburg, Franz-Josef-Strauß-Allee 11, 93053, Regensburg, Germany
| | - Florian Reetz
- Department of Internal Medicine II, University Medical Center Regensburg, Franz-Josef-Strauß-Allee 11, 93053, Regensburg, Germany
| | - Nataliya Dybkova
- Clinic for Cardiology & Pneumology, Georg-August University Goettingen, and DZHK (German Center for Cardiovascular Research), Robert-Koch-Str. 40, 37075, Goettingen, Germany
| | - Orr Shomroni
- NGS-Integrative Genomics (NIG) Institute Human Genetics (O.S., G.S.), University Medical Center Goettingen, Georg-August University, Goettingen, Germany
| | - Gabriela Salinas
- NGS-Integrative Genomics (NIG) Institute Human Genetics (O.S., G.S.), University Medical Center Goettingen, Georg-August University, Goettingen, Germany
| | - Julian Mustroph
- Department of Internal Medicine II, University Medical Center Regensburg, Franz-Josef-Strauß-Allee 11, 93053, Regensburg, Germany
| | - Karin P Hammer
- Department of Internal Medicine II, University Medical Center Regensburg, Franz-Josef-Strauß-Allee 11, 93053, Regensburg, Germany
| | - Gerd Hasenfuss
- Clinic for Cardiology & Pneumology, Georg-August University Goettingen, and DZHK (German Center for Cardiovascular Research), Robert-Koch-Str. 40, 37075, Goettingen, Germany
| | - Nazha Hamdani
- Institute of Physiology, Ruhr University Bochum, Bochum, Germany
| | - Lars S Maier
- Department of Internal Medicine II, University Medical Center Regensburg, Franz-Josef-Strauß-Allee 11, 93053, Regensburg, Germany
| | - Katrin Streckfuss-Bömeke
- Clinic for Cardiology & Pneumology, Georg-August University Goettingen, and DZHK (German Center for Cardiovascular Research), Robert-Koch-Str. 40, 37075, Goettingen, Germany.
| | - Samuel Sossalla
- Department of Internal Medicine II, University Medical Center Regensburg, Franz-Josef-Strauß-Allee 11, 93053, Regensburg, Germany.
- Clinic for Cardiology & Pneumology, Georg-August University Goettingen, and DZHK (German Center for Cardiovascular Research), Robert-Koch-Str. 40, 37075, Goettingen, Germany.
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Liu N, Li X, Fu Y, Li Y, Lu W, Pan Y, Yang J, Kong J. Inhibition of lung cancer by vitamin D depends on downregulation of histidine-rich calcium-binding protein. J Adv Res 2020; 29:13-22. [PMID: 33842001 PMCID: PMC8020154 DOI: 10.1016/j.jare.2020.08.013] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2020] [Revised: 07/21/2020] [Accepted: 08/17/2020] [Indexed: 12/25/2022] Open
Abstract
Introduction Intrinsic vitamin D affects the proliferation, apoptosis, invasion, metastasis, and tumorigenesis of lung cancer by regulating tumor signaling pathways. Histidine-rich calcium-binding protein (HRC) maintains Ca2+ homeostasis, which plays crucial roles in the occurrence and development of cancer. Objectives Our study aims to investigate the ability of vitamin D in the regulation of HRC and the role of HRC playing in lung cancer. Methods We investigated the effects of vitamin D on lung cancer and the underlying mechanisms, by measuring HRC and vitamin D receptor (VDR) expression in lung cancer, paracancer, and normal tissues from patients using immunohistochemistry, western blotting, and real time RT-PCR. We transfected H460 lung cancer cells (supplemented or not with vitamin D) with PX458-HRC and pcDNA3.1-HRC plasmids and injected mice with lung cancer cells harboring pcDNA3.1-vector or pcDNA3.1-HRC plasmids. Results Vitamin D inhibited HRC expression and H460 cell migration and proliferation, and promoted apoptosis compared with controls. The expression of HRC and VDR was significantly upregulated and downregulated, respectively, in lung cancer versus paracancer or normal tissues. Cell proliferation and migration were reduced, apoptotic cells were more and tumors were smaller in mice treated with vitamin D/cholecalciferol cholesterol emulsion (CCE) than in vitamin D/CCE+HRC+/+ mice. Conclusion Vitamin D inhibited lung cancer tumor growth, migration, and proliferation by downregulating HRC.
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Affiliation(s)
- Ning Liu
- Department of Clinical Nutrition, Shengjing Hospital of China Medical University, Shenyang 110004, China
| | - Xiaofeng Li
- Department of Clinical Nutrition, Shengjing Hospital of China Medical University, Shenyang 110004, China
- Children's Neurorehabilitation Laboratory, Shenyang Children's Hospital, Shenyang 110032, China
| | - Yu Fu
- Department of Clinical Nutrition, Shengjing Hospital of China Medical University, Shenyang 110004, China
| | - Ye Li
- Department of Clinical Nutrition, Shengjing Hospital of China Medical University, Shenyang 110004, China
| | - Wanyi Lu
- Department of Clinical Nutrition, Shengjing Hospital of China Medical University, Shenyang 110004, China
| | - Yiming Pan
- Department of Clinical Nutrition, Shengjing Hospital of China Medical University, Shenyang 110004, China
| | - Jingxin Yang
- Department of Clinical Nutrition, Shengjing Hospital of China Medical University, Shenyang 110004, China
| | - Juan Kong
- Department of Clinical Nutrition, Shengjing Hospital of China Medical University, Shenyang 110004, China
- Corresponding author at: Department of Clinical Nutrition, Shengjing Hospital of China Medical University, Shenyang 110004, China.
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15
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Lu S, Liao Z, Lu X, Katschinski DM, Mercola M, Chen J, Heller Brown J, Molkentin JD, Bossuyt J, Bers DM. Hyperglycemia Acutely Increases Cytosolic Reactive Oxygen Species via O-linked GlcNAcylation and CaMKII Activation in Mouse Ventricular Myocytes. Circ Res 2020; 126:e80-e96. [PMID: 32134364 DOI: 10.1161/circresaha.119.316288] [Citation(s) in RCA: 76] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
RATIONALE Diabetes mellitus is a complex, multisystem disease, affecting large populations worldwide. Chronic CaMKII (Ca2+/calmodulin-dependent kinase II) activation may occur in diabetes mellitus and be arrhythmogenic. Diabetic hyperglycemia was shown to activate CaMKII by (1) O-linked attachment of N-acetylglucosamine (O-GlcNAc) at S280 leading to arrhythmia and (2) a reactive oxygen species (ROS)-mediated oxidation of CaMKII that can increase postinfarction mortality. OBJECTIVE To test whether high extracellular glucose (Hi-Glu) promotes ventricular myocyte ROS generation and the role played by CaMKII. METHODS AND RESULTS We tested how extracellular Hi-Glu influences ROS production in adult ventricular myocytes, using DCF (2',7'-dichlorodihydrofluorescein diacetate) and genetically targeted Grx-roGFP2 redox sensors. Hi-Glu (30 mmol/L) significantly increased the rate of ROS generation-an effect prevented in myocytes pretreated with CaMKII inhibitor KN-93 or from either global or cardiac-specific CaMKIIδ KO (knockout) mice. CaMKII KO or inhibition also prevented Hi-Glu-induced sarcoplasmic reticulum Ca2+ release events (Ca2+ sparks). Thus, CaMKII activation is required for Hi-Glu-induced ROS generation and sarcoplasmic reticulum Ca2+ leak in cardiomyocytes. To test the involvement of O-GlcNAc-CaMKII pathway, we inhibited GlcNAcylation removal by Thiamet G (ThmG), which mimicked the Hi-Glu-induced ROS production. Conversely, inhibition of GlcNAcylation (OSMI-1 [(αR)-α-[[(1,2-dihydro-2-oxo-6-quinolinyl)sulfonyl]amino]-N-(2-furanylmethyl)-2-methoxy-N-(2-thienylmethyl)-benzeneacetamide]) prevented ROS induction in response to either Hi-Glu or ThmG. Moreover, in a CRSPR-based knock-in mouse in which the functional GlcNAcylation site on CaMKIIδ was ablated (S280A), neither Hi-Glu nor ThmG induced myocyte ROS generation. So CaMKIIδ-S280 is required for the Hi-Glu-induced (and GlcNAc dependent) ROS production. To identify the ROS source(s), we used different inhibitors of NOX (NADPH oxidase) 2 (Gp91ds-tat peptide), NOX4 (GKT137831), mitochondrial ROS (MitoTempo), and NOS (NO synthase) pathway inhibitors (L-NAME, L-NIO, and L-NPA). Only NOX2 inhibition or KO prevented Hi-Glu/ThmG-induced ROS generation. CONCLUSIONS Diabetic hyperglycemia induces acute cardiac myocyte ROS production by NOX2 that requires O-GlcNAcylation of CaMKIIδ at S280. This novel ROS induction may exacerbate pathological consequences of diabetic hyperglycemia.
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Affiliation(s)
- Shan Lu
- From the Department of Pharmacology, University of California, Davis School of Medicine (S.L., Z.L., J.B., D.M.B.)
| | - Zhandi Liao
- From the Department of Pharmacology, University of California, Davis School of Medicine (S.L., Z.L., J.B., D.M.B.)
| | - Xiyuan Lu
- Department of Cardiology, Renji Hospital School of Medicine, Jiaotong University, Shanghai, China (X.L.)
| | - Dörthe M Katschinski
- Institute of Cardiovascular Physiology, University Medical Centre Göttingen, Germany (D.M.K.)
- German Center for Cardiovascular Research, Partner Site, Göttingen (D.M.K.)
| | - Mark Mercola
- Stanford Cardiovascular Institute and Department of Medicine, Stanford University, CA (M.M.)
| | - Ju Chen
- Department of Medicine (J.C.), University of California San Diego, La Jolla
| | - Joan Heller Brown
- Department of Pharmacology (J.H.B.), University of California San Diego, La Jolla
| | - Jeffery D Molkentin
- Department of Pediatrics, University of Cincinnati, Cincinnati Children's Hospital Medical Center, OH (J.D.M.)
| | - Julie Bossuyt
- From the Department of Pharmacology, University of California, Davis School of Medicine (S.L., Z.L., J.B., D.M.B.)
| | - Donald M Bers
- From the Department of Pharmacology, University of California, Davis School of Medicine (S.L., Z.L., J.B., D.M.B.)
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Chen HH, Wang SN, Cao TT, Zheng JL, Tian J, Shan XL, Zhao P, Guo W, Xu M, Zhang C, Lu R. Stachydrine hydrochloride alleviates pressure overload-induced heart failure and calcium mishandling on mice. J Ethnopharmacol 2020; 248:112306. [PMID: 31626909 DOI: 10.1016/j.jep.2019.112306] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2019] [Revised: 09/16/2019] [Accepted: 10/12/2019] [Indexed: 06/10/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Traditional Chinese medicine Leonurus japonicus Houtt. has a long history in the treatment of cardiovascular diseases. Stachydrine hydrochloride, the main bioactive ingredient extracted from Leonurus japonicus Houtt., has been shown to have cardioprotective effects. However, the underlying mechanisms of stachydrine hydrochloride haven't been comprehensively studied so far. AIM OF THE STUDY The aim of this study was to investigate the protective role of stachydrine hydrochloride in heart failure and elucidate its possible mechanisms of action. MATERIALS AND METHODS In vivo, transverse aorta constriction was carried out in C57BL/6J mice, and thereafter, 7.2 mg/kg telmisartan (a selective AT1R antagonist as positive control) and 12 mg/kg stachydrine hydrochloride was administered daily intragastrically for 4 weeks. Cardiac function was evaluated by assessing morphological changes as well as echocardiographic and haemodynamic parameters. In vitro, neonatal rat cardiomyocytes or adult mice cardiomyocytes were treated with stachydrine hydrochloride and challenged with phenylephrine (α-AR agonist). Ventricular myocytes were isolated from the hearts of C57BL/6J mice by Langendorff crossflow perfusion system. Intracellular calcium was measured by an ion imaging system. The length and movement of sarcomere were traced to evaluate the systolic and diastolic function of single myocardial cells. RESULTS Stachydrine hydrochloride improved the cardiac function and calcium transient amplitudes, and inhibited the SR leakage and the amount of sparks in cardiac myocytes isolated from TAC mice. We also demonstrated that stachydrine hydrochloride could ameliorated phenylephrine-induced enhance in sarcomere contraction, calcium transients and calcium sparks. Moreover, our data shown that stachydrine hydrochloride blocked the hyper-phosphorylation of CaMKII, RyR2, PLN, and prevented the disassociation of FKBP12.6 from RyR2. CONCLUSION Our results suggest that stachydrine hydrochloride exerts beneficial therapeutic effects against heart failure. These cardioprotective effects may be associated with the regulation of calcium handling by stachydrine hydrochloride through inhibiting the hyper-phosphorylation of CaMKII.
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Affiliation(s)
- Hui-Hua Chen
- School of Basic Medical Science, Shanghai University of Traditional Chinese Medicine, Shanghai, China.
| | - Si-Ning Wang
- School of Basic Medical Science, Shanghai University of Traditional Chinese Medicine, Shanghai, China.
| | | | - Jia-Li Zheng
- School of Basic Medical Science, Shanghai University of Traditional Chinese Medicine, Shanghai, China.
| | - Jing Tian
- School of Basic Medical Science, Shanghai University of Traditional Chinese Medicine, Shanghai, China.
| | - Xiao-Li Shan
- Public Laboratory Platform, School of Basic Medical Science, Shanghai University of Traditional Chinese Medicine, Shanghai, China.
| | - Pei Zhao
- Public Laboratory Platform, School of Basic Medical Science, Shanghai University of Traditional Chinese Medicine, Shanghai, China.
| | - Wei Guo
- Department of Pathology, Shanghai University of Traditional Chinese Medicine, Shanghai, China.
| | - Ming Xu
- Department of Physiology, Shanghai University of Traditional Chinese Medicine, Shanghai, China.
| | - Chen Zhang
- Department of Pathology, Shanghai University of Traditional Chinese Medicine, Shanghai, China.
| | - Rong Lu
- School of Basic Medical Science, Shanghai University of Traditional Chinese Medicine, Shanghai, China.
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Sánchez-Gómez L, Guerrero-Hernández A, Santillán M. Polymerization of sarcoplasmic-reticulum calcium-binding proteins might explain observed reticulum kinetics-on-demand behavior. J Theor Biol 2019; 482:109986. [PMID: 31465729 DOI: 10.1016/j.jtbi.2019.08.017] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2019] [Revised: 08/20/2019] [Accepted: 08/26/2019] [Indexed: 11/20/2022]
Abstract
Reported experimental results, in which transient elevations of sarcoplasmic calcium levels are induced by caffeine in smooth muscle cells, apparently contradict the principle of mass conservation. The commonly accepted model assumes that the total number of Ca2+ binding sites is fixed. A former work dealing with this problem proved that assuming the presence within the reticulum of calcium sequestering proteins whose total number of calcium binding sites increases as the existent sites get occupied, is enough to explain the above referred counter-intuitive experimental results. However, no chemical explanation was given to account for this binding-site count increase. In the present work, we propose a chemical-kinetics scheme for the binding of calcium to calsequestrin (a protein found within the reticulum) and the polymerization of this protein. On the one hand, this scheme is in agreement with reported results on calsequestrin binding kinetics, but it is also fully capable of explaining the observed intriguing performance of the sarcoplasmic reticulum. We further explore the behavior of the resulting nonlinear dynamic system and discuss possible physiological implications of the proposed scheme.
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Affiliation(s)
- Laura Sánchez-Gómez
- Centro de Investigación y de Estudios Avanzados del IPN, Unidad Monterrey, Vía del Conocimiento 201, Apodaca, NL 66600, México
| | - Agustín Guerrero-Hernández
- Centro de Investigación y de Estudios Avanzados del IPN, Unidad Zacatenco, Departamento de Bioquímica, Av. Instituto Politécnico Nacional 2508, Ciudad de México, 07000, México
| | - Moisés Santillán
- Centro de Investigación y de Estudios Avanzados del IPN, Unidad Monterrey, Vía del Conocimiento 201, Apodaca, NL 66600, México.
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Pioner JM, Santini L, Palandri C, Martella D, Lupi F, Langione M, Querceto S, Grandinetti B, Balducci V, Benzoni P, Landi S, Barbuti A, Ferrarese Lupi F, Boarino L, Sartiani L, Tesi C, Mack DL, Regnier M, Cerbai E, Parmeggiani C, Poggesi C, Ferrantini C, Coppini R. Optical Investigation of Action Potential and Calcium Handling Maturation of hiPSC-Cardiomyocytes on Biomimetic Substrates. Int J Mol Sci 2019; 20:ijms20153799. [PMID: 31382622 PMCID: PMC6695920 DOI: 10.3390/ijms20153799] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2019] [Revised: 07/31/2019] [Accepted: 08/01/2019] [Indexed: 12/18/2022] Open
Abstract
Cardiomyocytes from human induced pluripotent stem cells (hiPSC-CMs) are the most promising human source with preserved genetic background of healthy individuals or patients. This study aimed to establish a systematic procedure for exploring development of hiPSC-CM functional output to predict genetic cardiomyopathy outcomes and identify molecular targets for therapy. Biomimetic substrates with microtopography and physiological stiffness can overcome the immaturity of hiPSC-CM function. We have developed a custom-made apparatus for simultaneous optical measurements of hiPSC-CM action potential and calcium transients to correlate these parameters at specific time points (day 60, 75 and 90 post differentiation) and under inotropic interventions. In later-stages, single hiPSC-CMs revealed prolonged action potential duration, increased calcium transient amplitude and shorter duration that closely resembled those of human adult cardiomyocytes from fresh ventricular tissue of patients. Thus, the major contribution of sarcoplasmic reticulum and positive inotropic response to β-adrenergic stimulation are time-dependent events underlying excitation contraction coupling (ECC) maturation of hiPSC-CM; biomimetic substrates can promote calcium-handling regulation towards adult-like kinetics. Simultaneous optical recordings of long-term cultured hiPSC-CMs on biomimetic substrates favor high-throughput electrophysiological analysis aimed at testing (mechanistic hypothesis on) disease progression and pharmacological interventions in patient-derived hiPSC-CMs.
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Affiliation(s)
- Josè Manuel Pioner
- Department of Experimental and Clinical Medicine, Division of Physiology, Università degli studi di Firenze, 50134 Florence, Italy.
| | - Lorenzo Santini
- Department NeuroFarBa, University of Florence, 50134 Florence, Italy
| | - Chiara Palandri
- Department NeuroFarBa, University of Florence, 50134 Florence, Italy
| | - Daniele Martella
- European Laboratory for Non-Linear Spectroscopy (LENS), 50019 Florence, Italy
- National Institute of Optics, CNR-INO, 50125 Florence, Italy
| | - Flavia Lupi
- European Laboratory for Non-Linear Spectroscopy (LENS), 50019 Florence, Italy
| | - Marianna Langione
- Department of Experimental and Clinical Medicine, Division of Physiology, Università degli studi di Firenze, 50134 Florence, Italy
| | - Silvia Querceto
- Department of Experimental and Clinical Medicine, Division of Physiology, Università degli studi di Firenze, 50134 Florence, Italy
| | - Bruno Grandinetti
- European Laboratory for Non-Linear Spectroscopy (LENS), 50019 Florence, Italy
| | | | - Patrizia Benzoni
- Department of Biosciences, Università degli studi di Milano, 20137 Milan, Italy
| | - Sara Landi
- Department of Biosciences, Università degli studi di Milano, 20137 Milan, Italy
| | - Andrea Barbuti
- Department of Biosciences, Università degli studi di Milano, 20137 Milan, Italy
| | | | - Luca Boarino
- Istituto Nazionale di Ricerca Metrologica INRiM, 10129 Turin, Italy
| | - Laura Sartiani
- Department NeuroFarBa, University of Florence, 50134 Florence, Italy
| | - Chiara Tesi
- Department of Experimental and Clinical Medicine, Division of Physiology, Università degli studi di Firenze, 50134 Florence, Italy
| | - David L Mack
- Department of Rehabilitation Medicine, University of Washington, Seattle, WA 98108, USA
| | - Michael Regnier
- Department of Bioengineering, University of Washington, Seattle, WA 98108, USA
| | - Elisabetta Cerbai
- Department NeuroFarBa, University of Florence, 50134 Florence, Italy
| | - Camilla Parmeggiani
- European Laboratory for Non-Linear Spectroscopy (LENS), 50019 Florence, Italy
- Department of Chemistry "Ugo Schiff", University of Florence, 50134 Florence, Italy
| | - Corrado Poggesi
- Department of Experimental and Clinical Medicine, Division of Physiology, Università degli studi di Firenze, 50134 Florence, Italy
| | - Cecilia Ferrantini
- Department of Experimental and Clinical Medicine, Division of Physiology, Università degli studi di Firenze, 50134 Florence, Italy
- European Laboratory for Non-Linear Spectroscopy (LENS), 50019 Florence, Italy
| | - Raffaele Coppini
- Department NeuroFarBa, University of Florence, 50134 Florence, Italy.
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Bovo E, Nikolaienko R, Bhayani S, Kahn D, Cao Q, Martin JL, Kuo IY, Robia SL, Zima AV. Novel approach for quantification of endoplasmic reticulum Ca 2+ transport. Am J Physiol Heart Circ Physiol 2019; 316:H1323-H1331. [PMID: 30901276 PMCID: PMC6620677 DOI: 10.1152/ajpheart.00031.2019] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/22/2019] [Revised: 03/01/2019] [Accepted: 03/04/2019] [Indexed: 01/14/2023]
Abstract
The type 2a sarco-/endoplasmic reticulum Ca2+-ATPase (SERCA2a) plays a key role in Ca2+ regulation in the heart. However, available techniques to study SERCA function are either cell destructive or lack sensitivity. The goal of this study was to develop an approach to selectively measure SERCA2a function in the cellular environment. The genetically encoded Ca2+ sensor R-CEPIA1er was used to measure the concentration of Ca2+ in the lumen of the endoplasmic reticulum (ER) ([Ca2+]ER) in HEK293 cells expressing human SERCA2a. Coexpression of the ER Ca2+ release channel ryanodine receptor (RyR2) created a Ca2+ release/reuptake system that mimicked aspects of cardiac myocyte Ca2+ handling. SERCA2a function was quantified from the rate of [Ca2+]ER refilling after ER Ca2+ depletion; then, ER Ca2+ leak was measured after SERCA inhibition. ER Ca2+ uptake and leak were analyzed as a function of [Ca2+]ER to determine maximum ER Ca2+ uptake rate and maximum ER Ca2+ load. The sensitivity of this assay was validated by analyzing effects of SERCA inhibitors, [ATP]/[ADP], oxidative stress, phospholamban, and a loss-of-function SERCA2a mutation. In addition, the feasibility of using R-CEPIA1er to study SERCA2a in a native system was evaluated by using in vivo gene delivery to express R-CEPIA1er in mouse hearts. After ventricular myocyte isolation, the same methodology used in HEK293 cells was applied to study endogenous SERCA2a. In conclusion, this new approach can be used as a sensitive screening tool to study the effect of different drugs, posttranslational modifications, and mutations on SERCA function. NEW & NOTEWORTHY The aim of this study was to develop a sensitive approach to selectively measure sarco-/endoplasmic reticulum Ca2+-ATPase (SERCA) function in the cellular environment. The newly developed Ca2+ sensor R-CEPIA1er was used to successfully analyze Ca2+ uptake mediated by recombinant and native cardiac SERCA. These results demonstrate that this new approach can be used as a powerful tool to study new mechanisms of Ca2+ pump regulation.
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Affiliation(s)
- Elisa Bovo
- Department of Cell and Molecular Physiology, Loyola University Chicago , Chicago, Illinois
| | - Roman Nikolaienko
- Department of Cell and Molecular Physiology, Loyola University Chicago , Chicago, Illinois
| | - Siddharth Bhayani
- Department of Cell and Molecular Physiology, Loyola University Chicago , Chicago, Illinois
| | - Daniel Kahn
- Department of Cell and Molecular Physiology, Loyola University Chicago , Chicago, Illinois
| | - Quan Cao
- Department of Cell and Molecular Physiology, Loyola University Chicago , Chicago, Illinois
| | - Jody L Martin
- Department of Physiology and Biophysics, University of Illinois at Chicago , Chicago, Illinois
| | - Ivana Y Kuo
- Department of Cell and Molecular Physiology, Loyola University Chicago , Chicago, Illinois
| | - Seth L Robia
- Department of Cell and Molecular Physiology, Loyola University Chicago , Chicago, Illinois
| | - Aleksey V Zima
- Department of Cell and Molecular Physiology, Loyola University Chicago , Chicago, Illinois
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20
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Tscheschner H, Meinhardt E, Schlegel P, Jungmann A, Lehmann LH, Müller OJ, Most P, Katus HA, Raake PW. CaMKII activation participates in doxorubicin cardiotoxicity and is attenuated by moderate GRP78 overexpression. PLoS One 2019; 14:e0215992. [PMID: 31034488 PMCID: PMC6488194 DOI: 10.1371/journal.pone.0215992] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2018] [Accepted: 04/11/2019] [Indexed: 12/23/2022] Open
Abstract
The clinical use of the chemotherapeutic doxorubicin (Dox) is limited by cardiotoxic side-effects. One of the early Dox effects is induction of a sarcoplasmic reticulum (SR) Ca2+ leak. The chaperone Glucose regulated protein 78 (GRP78) is important for Ca2+ homeostasis in the endoplasmic reticulum (ER)—the organelle corresponding to the SR in non-cardiomyocytes—and has been shown to convey resistance to Dox in certain tumors. Our aim was to investigate the effect of cardiac GRP78 gene transfer on Ca2+ dependent signaling, cell death, cardiac function and survival in clinically relevant in vitro and in vivo models for Dox cardiotoxicity.By using neonatal cardiomyocytes we could demonstrate that Dox induced Ca2+ dependent Ca2+ /calmodulin-dependent protein kinase II (CaMKII) activation is one of the factors involved in Dox cardiotoxicity by promoting apoptosis. Furthermore, we found that adeno-associated virus (AAV) mediated GRP78 overexpression partly protects neonatal cardiomyocytes from Dox induced cell death by modulating Ca2+ dependent pathways like the activation of CaMKII, phospholamban (PLN) and p53 accumulation. Most importantly, cardiac GRP78 gene therapy in mice treated with Dox revealed improved diastolic function (dP/dtmin) and survival after Dox treatment. In conclusion, our results demonstrate for the first time that Ca2+ dependent CaMKII activation fosters Dox cardiomyopathy and provide additional insight into possible mechanisms by which GRP78 overexpression protects cardiomyocytes from Doxorubicin toxicity.
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Affiliation(s)
- Henrike Tscheschner
- Department of Internal Medicine III, Cardiology, University Hospital Heidelberg, University of Heidelberg, Heidelberg, Germany
| | - Eric Meinhardt
- Department of Internal Medicine III, Cardiology, University Hospital Heidelberg, University of Heidelberg, Heidelberg, Germany
| | - Philipp Schlegel
- Department of Internal Medicine III, Cardiology, University Hospital Heidelberg, University of Heidelberg, Heidelberg, Germany
- DZHK (German Centre for Cardiovascular Research), Partner Site Heidelberg/Mannheim, Heidelberg, Germany
| | - Andreas Jungmann
- Department of Internal Medicine III, Cardiology, University Hospital Heidelberg, University of Heidelberg, Heidelberg, Germany
| | - Lorenz H. Lehmann
- Department of Internal Medicine III, Cardiology, University Hospital Heidelberg, University of Heidelberg, Heidelberg, Germany
- DZHK (German Centre for Cardiovascular Research), Partner Site Heidelberg/Mannheim, Heidelberg, Germany
| | - Oliver J. Müller
- Department of Internal Medicine III, Cardiology, University Hospital Heidelberg, University of Heidelberg, Heidelberg, Germany
- DZHK (German Centre for Cardiovascular Research), Partner Site Heidelberg/Mannheim, Heidelberg, Germany
- Department of Internal Medicine III, Cardiology, Angiology and Intensive Care Medicine, University Hospital Kiel, Kiel, Germany
| | - Patrick Most
- Department of Internal Medicine III, Cardiology, University Hospital Heidelberg, University of Heidelberg, Heidelberg, Germany
- DZHK (German Centre for Cardiovascular Research), Partner Site Heidelberg/Mannheim, Heidelberg, Germany
| | - Hugo A. Katus
- Department of Internal Medicine III, Cardiology, University Hospital Heidelberg, University of Heidelberg, Heidelberg, Germany
- DZHK (German Centre for Cardiovascular Research), Partner Site Heidelberg/Mannheim, Heidelberg, Germany
| | - Philip W. Raake
- Department of Internal Medicine III, Cardiology, University Hospital Heidelberg, University of Heidelberg, Heidelberg, Germany
- * E-mail:
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21
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Tan CS, Loh YC, Ch'ng YS, Ng CH, Yeap ZQ, Ahmad M, Asmawi MZ, Yam MF. Vasorelaxant and chemical fingerprint studies of Citrus reticulatae pericarpium extracts. J Ethnopharmacol 2019; 232:135-144. [PMID: 30543913 DOI: 10.1016/j.jep.2018.12.014] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2018] [Revised: 11/16/2018] [Accepted: 12/08/2018] [Indexed: 06/09/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Citrus reticulatae Pericarpium (Chen pi) was widely used as an important ingredient in the prescription of TCM to treat phlegm fluid retention type hypertension. Since Chen pi is involved in treatment as antihypertensive TCM formula, we have reasonable expectation in believing that it might possess vasorelaxant activity. AIM OF THE STUDY This study is designed to investigate the vasorelaxant effect of Chen pi and to study its pharmacology effects. MATERIALS AND METHODS The vasorelaxant effect of water extract of Chen pi (CRW) were evaluated on thoracic aortic rings isolated from Sprague Dawley rats. The fingerprint of Chen pi and the extracts were developed with quantification of hesperidin content by HPTLC. RESULTS CRW exhibited the strongest vasorelaxant activity. CRW caused the relaxation of the phenylephrine pre-contracted aortic rings in the presence and absence of endothelium as well as in potassium chloride pre-contracted endothelium-intact aortic ring. The incubation of propranolol (β-adrenergic receptor blocker), atropine (muscarinic receptor blocker), Nω-nitro-L-arginine methyl ester (NO synthase inhibitor), ODQ (sGC inhibitor), indomethacin (COX inhibitor), 4-aminopyridine (KV blocker), barium chloride (Kir blocker), and glibenclamide (KATP blocker) significantly reduced the vasorelaxant effects of CRW. CRW was also found to be active in reducing Ca2+ releases from the sarcoplasmic reticulum and suppressing the voltage-operated calcium channels. CONCLUSION The vasorelaxant effect of CRW on rat aorta involves NO/sGC, calcium and potassium channels, muscarinic and β-adrenergic receptors.
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Affiliation(s)
- Chu Shan Tan
- School of Pharmaceutical Sciences, Universiti Sains Malaysia, 11800 Minden, Pulau Pinang, Malaysia
| | - Yean Chun Loh
- School of Pharmaceutical Sciences, Universiti Sains Malaysia, 11800 Minden, Pulau Pinang, Malaysia
| | - Yung Sing Ch'ng
- School of Pharmaceutical Sciences, Universiti Sains Malaysia, 11800 Minden, Pulau Pinang, Malaysia
| | - Chiew Hoong Ng
- School of Pharmaceutical Sciences, Universiti Sains Malaysia, 11800 Minden, Pulau Pinang, Malaysia
| | - Zhao Qin Yeap
- School of Pharmaceutical Sciences, Universiti Sains Malaysia, 11800 Minden, Pulau Pinang, Malaysia
| | - Mariam Ahmad
- School of Pharmaceutical Sciences, Universiti Sains Malaysia, 11800 Minden, Pulau Pinang, Malaysia
| | - Mohd Zaini Asmawi
- School of Pharmaceutical Sciences, Universiti Sains Malaysia, 11800 Minden, Pulau Pinang, Malaysia
| | - Mun Fei Yam
- School of Pharmaceutical Sciences, Universiti Sains Malaysia, 11800 Minden, Pulau Pinang, Malaysia; College of Pharmacy, Fujian University of Traditional Chinese Medicine, Fuzhou 350122, China.
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22
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Wang R, Zhang J, Wang S, Wang M, Ye T, Du Y, Xie X, Ye J, Sun G, Sun X. The Cardiotoxicity Induced by Arsenic Trioxide is Alleviated by Salvianolic Acid A via Maintaining Calcium Homeostasis and Inhibiting Endoplasmic Reticulum Stress. Molecules 2019; 24:molecules24030543. [PMID: 30717322 PMCID: PMC6384753 DOI: 10.3390/molecules24030543] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2019] [Revised: 01/29/2019] [Accepted: 01/30/2019] [Indexed: 12/02/2022] Open
Abstract
Arsenic trioxide (ATO) has been verified as a breakthrough with respect to the management of acute promyelocytic leukemia (APL) in recent decades but associated with some serious adverse phenomena, particularly cardiac functional abnormalities. Salvianolic acid A (Sal A) is a major effective component in treating ATO-induced cardiotoxicity. Therefore, the objective of our study was to assess whether Sal A had protective effects by the regulation of calcium homeostasis and endoplasmic reticulum (ER) stress. For the in vivo study, BALB/c mice were treated with ATO and/or Sal A via daily tail vein injections for two weeks. For the in vitro study, we detected the effects of ATO and/or Sal A in real time using adult rat ventricular myocytes (ARVMs) and an IonOptix MyoCam system. Our results showed that Sal A pretreatment alleviated cardiac dysfunction and Ca2+ overload induced by ATO in vivo and vitro. Moreover, Sal A increased sarcoplasmic reticulum (SR) Ca2+-ATPase (SERCA) activity and expression, alleviated [Ca2+]ER depletion, and decreased ER stress-related protein expression. Sal A protects the heart from ATO-induced injury and its administration correlates with the modulation of SERCA, the recovery of Ca2+ homeostasis, and the down-regulation of ER stress-mediated apoptosis.
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Affiliation(s)
- Ruiying Wang
- Beijing Key Laboratory of Innovative Drug Discovery of Traditional Chinese Medicine (Natural Medicine) and Translational Medicine, Institute of Medicinal Plant Development, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing 100193, China.
- Key Laboratory of Bioactive Substances and Resource Utilization of Chinese Herbal Medicine, Ministry of Education, Beijing 100193, China.
- Key Laboratory of Efficacy Evaluation of Chinese Medicine against Glycolipid Metabolic Disorders, State Administration of Traditional Chinese Medicine, Beijing 100193, China.
- Zhongguancun Open Laboratory of the Research and Development of Natural Medicine and Health Products, Beijing 100193, China.
| | - Jingyi Zhang
- Beijing Key Laboratory of Innovative Drug Discovery of Traditional Chinese Medicine (Natural Medicine) and Translational Medicine, Institute of Medicinal Plant Development, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing 100193, China.
- Key Laboratory of Bioactive Substances and Resource Utilization of Chinese Herbal Medicine, Ministry of Education, Beijing 100193, China.
- Key Laboratory of Efficacy Evaluation of Chinese Medicine against Glycolipid Metabolic Disorders, State Administration of Traditional Chinese Medicine, Beijing 100193, China.
- Zhongguancun Open Laboratory of the Research and Development of Natural Medicine and Health Products, Beijing 100193, China.
| | - Shan Wang
- Beijing Key Laboratory of Innovative Drug Discovery of Traditional Chinese Medicine (Natural Medicine) and Translational Medicine, Institute of Medicinal Plant Development, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing 100193, China.
- Key Laboratory of Bioactive Substances and Resource Utilization of Chinese Herbal Medicine, Ministry of Education, Beijing 100193, China.
- Key Laboratory of Efficacy Evaluation of Chinese Medicine against Glycolipid Metabolic Disorders, State Administration of Traditional Chinese Medicine, Beijing 100193, China.
- Zhongguancun Open Laboratory of the Research and Development of Natural Medicine and Health Products, Beijing 100193, China.
| | - Min Wang
- Beijing Key Laboratory of Innovative Drug Discovery of Traditional Chinese Medicine (Natural Medicine) and Translational Medicine, Institute of Medicinal Plant Development, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing 100193, China.
- Key Laboratory of Bioactive Substances and Resource Utilization of Chinese Herbal Medicine, Ministry of Education, Beijing 100193, China.
- Key Laboratory of Efficacy Evaluation of Chinese Medicine against Glycolipid Metabolic Disorders, State Administration of Traditional Chinese Medicine, Beijing 100193, China.
- Zhongguancun Open Laboratory of the Research and Development of Natural Medicine and Health Products, Beijing 100193, China.
| | - Tianyuan Ye
- Beijing Key Laboratory of Innovative Drug Discovery of Traditional Chinese Medicine (Natural Medicine) and Translational Medicine, Institute of Medicinal Plant Development, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing 100193, China.
- Key Laboratory of Bioactive Substances and Resource Utilization of Chinese Herbal Medicine, Ministry of Education, Beijing 100193, China.
- Key Laboratory of Efficacy Evaluation of Chinese Medicine against Glycolipid Metabolic Disorders, State Administration of Traditional Chinese Medicine, Beijing 100193, China.
- Zhongguancun Open Laboratory of the Research and Development of Natural Medicine and Health Products, Beijing 100193, China.
| | - Yuyang Du
- Beijing Key Laboratory of Innovative Drug Discovery of Traditional Chinese Medicine (Natural Medicine) and Translational Medicine, Institute of Medicinal Plant Development, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing 100193, China.
- Key Laboratory of Bioactive Substances and Resource Utilization of Chinese Herbal Medicine, Ministry of Education, Beijing 100193, China.
- Key Laboratory of Efficacy Evaluation of Chinese Medicine against Glycolipid Metabolic Disorders, State Administration of Traditional Chinese Medicine, Beijing 100193, China.
- Zhongguancun Open Laboratory of the Research and Development of Natural Medicine and Health Products, Beijing 100193, China.
| | - Xueheng Xie
- Harbin University of Commerce, Harbin 150028, China.
| | - Jingxue Ye
- Beijing Key Laboratory of Innovative Drug Discovery of Traditional Chinese Medicine (Natural Medicine) and Translational Medicine, Institute of Medicinal Plant Development, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing 100193, China.
- Key Laboratory of Bioactive Substances and Resource Utilization of Chinese Herbal Medicine, Ministry of Education, Beijing 100193, China.
- Key Laboratory of Efficacy Evaluation of Chinese Medicine against Glycolipid Metabolic Disorders, State Administration of Traditional Chinese Medicine, Beijing 100193, China.
- Zhongguancun Open Laboratory of the Research and Development of Natural Medicine and Health Products, Beijing 100193, China.
| | - Guibo Sun
- Beijing Key Laboratory of Innovative Drug Discovery of Traditional Chinese Medicine (Natural Medicine) and Translational Medicine, Institute of Medicinal Plant Development, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing 100193, China.
- Key Laboratory of Bioactive Substances and Resource Utilization of Chinese Herbal Medicine, Ministry of Education, Beijing 100193, China.
- Key Laboratory of Efficacy Evaluation of Chinese Medicine against Glycolipid Metabolic Disorders, State Administration of Traditional Chinese Medicine, Beijing 100193, China.
- Zhongguancun Open Laboratory of the Research and Development of Natural Medicine and Health Products, Beijing 100193, China.
| | - Xiaobo Sun
- Beijing Key Laboratory of Innovative Drug Discovery of Traditional Chinese Medicine (Natural Medicine) and Translational Medicine, Institute of Medicinal Plant Development, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing 100193, China.
- Key Laboratory of Bioactive Substances and Resource Utilization of Chinese Herbal Medicine, Ministry of Education, Beijing 100193, China.
- Key Laboratory of Efficacy Evaluation of Chinese Medicine against Glycolipid Metabolic Disorders, State Administration of Traditional Chinese Medicine, Beijing 100193, China.
- Zhongguancun Open Laboratory of the Research and Development of Natural Medicine and Health Products, Beijing 100193, China.
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23
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Rashid T, Nemazanyy I, Paolini C, Tatsuta T, Crespin P, de Villeneuve D, Brodesser S, Benit P, Rustin P, Baraibar MA, Agbulut O, Olivier A, Protasi F, Langer T, Chrast R, de Lonlay P, de Foucauld H, Blaauw B, Pende M. Lipin1 deficiency causes sarcoplasmic reticulum stress and chaperone-responsive myopathy. EMBO J 2019; 38:e99576. [PMID: 30420558 PMCID: PMC6315296 DOI: 10.15252/embj.201899576] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2018] [Revised: 09/21/2018] [Accepted: 10/02/2018] [Indexed: 12/20/2022] Open
Abstract
As a consequence of impaired glucose or fatty acid metabolism, bioenergetic stress in skeletal muscles may trigger myopathy and rhabdomyolysis. Genetic mutations causing loss of function of the LPIN1 gene frequently lead to severe rhabdomyolysis bouts in children, though the metabolic alterations and possible therapeutic interventions remain elusive. Here, we show that lipin1 deficiency in mouse skeletal muscles is sufficient to trigger myopathy. Strikingly, muscle fibers display strong accumulation of both neutral and phospholipids. The metabolic lipid imbalance can be traced to an altered fatty acid synthesis and fatty acid oxidation, accompanied by a defect in acyl chain elongation and desaturation. As an underlying cause, we reveal a severe sarcoplasmic reticulum (SR) stress, leading to the activation of the lipogenic SREBP1c/SREBP2 factors, the accumulation of the Fgf21 cytokine, and alterations of SR-mitochondria morphology. Importantly, pharmacological treatments with the chaperone TUDCA and the fatty acid oxidation activator bezafibrate improve muscle histology and strength of lipin1 mutants. Our data reveal that SR stress and alterations in SR-mitochondria contacts are contributing factors and potential intervention targets of the myopathy associated with lipin1 deficiency.
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Affiliation(s)
- Talha Rashid
- Institut Necker-Enfants Malades, Paris, France
- Inserm, U1151, Paris, France
- Université Paris Descartes, Sorbonne Paris Cité, Paris, France
- Sanofi R&D, Translational Sciences Unit, In Silico Biology, Chilly-Mazarin, France
| | - Ivan Nemazanyy
- Platform for Metabolic Analyses, Institut Necker-Enfants Malades, Paris, France
| | - Cecilia Paolini
- Center for Research on Ageing and Translational Medicine (CeSI-MeT), Department of Neuroscience, Imaging, and Clinical Sciences (DNICS), University G. d' Annunzio of Chieti, Chieti, Italy
| | - Takashi Tatsuta
- Max-Planck-Institute for Biology of Ageing, Cologne, Germany
| | - Paul Crespin
- Institut Necker-Enfants Malades, Paris, France
- Inserm, U1151, Paris, France
- Université Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - Delphine de Villeneuve
- Institut Necker-Enfants Malades, Paris, France
- Inserm, U1151, Paris, France
- Université Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - Susanne Brodesser
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
| | - Paule Benit
- INSERM, UMR 1141, Hôpital Robert Debré, Paris, France
| | - Pierre Rustin
- INSERM, UMR 1141, Hôpital Robert Debré, Paris, France
| | | | - Onnik Agbulut
- CNRS, Institut de Biologie Paris-Seine (IBPS), Biological Adaptation and Ageing, Sorbonne Université, Paris, France
| | - Anne Olivier
- Sanofi R&D, Translational Sciences Unit, In Silico Biology, Chilly-Mazarin, France
| | - Feliciano Protasi
- Center for Research on Ageing and Translational Medicine (CeSI-MeT), Department of Neuroscience, Imaging, and Clinical Sciences (DNICS), University G. d' Annunzio of Chieti, Chieti, Italy
| | - Thomas Langer
- Max-Planck-Institute for Biology of Ageing, Cologne, Germany
| | - Roman Chrast
- Department of Neuroscience and Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Pascale de Lonlay
- Institut Necker-Enfants Malades, Paris, France
- Inserm, U1151, Paris, France
- Université Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - Helene de Foucauld
- Sanofi R&D, Translational Sciences Unit, In Silico Biology, Chilly-Mazarin, France
| | - Bert Blaauw
- Department of Biomedical Sciences, Venetian Institute of Molecular Medicine, University of Padova, Padova, Italy
| | - Mario Pende
- Institut Necker-Enfants Malades, Paris, France
- Inserm, U1151, Paris, France
- Université Paris Descartes, Sorbonne Paris Cité, Paris, France
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24
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Hamilton A, Zhang Q, Salehi A, Willems M, Knudsen JG, Ringgaard AK, Chapman CE, Gonzalez-Alvarez A, Surdo NC, Zaccolo M, Basco D, Johnson PRV, Ramracheya R, Rutter GA, Galione A, Rorsman P, Tarasov AI. Adrenaline Stimulates Glucagon Secretion by Tpc2-Dependent Ca 2+ Mobilization From Acidic Stores in Pancreatic α-Cells. Diabetes 2018; 67:1128-1139. [PMID: 29563152 PMCID: PMC6258900 DOI: 10.2337/db17-1102] [Citation(s) in RCA: 55] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/15/2017] [Accepted: 03/14/2018] [Indexed: 12/25/2022]
Abstract
Adrenaline is a powerful stimulus of glucagon secretion. It acts by activation of β-adrenergic receptors, but the downstream mechanisms have only been partially elucidated. Here, we have examined the effects of adrenaline in mouse and human α-cells by a combination of electrophysiology, imaging of Ca2+ and PKA activity, and hormone release measurements. We found that stimulation of glucagon secretion correlated with a PKA- and EPAC2-dependent (inhibited by PKI and ESI-05, respectively) elevation of [Ca2+]i in α-cells, which occurred without stimulation of electrical activity and persisted in the absence of extracellular Ca2+ but was sensitive to ryanodine, bafilomycin, and thapsigargin. Adrenaline also increased [Ca2+]i in α-cells in human islets. Genetic or pharmacological inhibition of the Tpc2 channel (that mediates Ca2+ release from acidic intracellular stores) abolished the stimulatory effect of adrenaline on glucagon secretion and reduced the elevation of [Ca2+]i Furthermore, in Tpc2-deficient islets, ryanodine exerted no additive inhibitory effect. These data suggest that β-adrenergic stimulation of glucagon secretion is controlled by a hierarchy of [Ca2+]i signaling in the α-cell that is initiated by cAMP-induced Tpc2-dependent Ca2+ release from the acidic stores and further amplified by Ca2+-induced Ca2+ release from the sarco/endoplasmic reticulum.
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Affiliation(s)
- Alexander Hamilton
- Oxford Centre for Diabetes, Endocrinology and Metabolism, Churchill Hospital, University of Oxford, Headington, U.K
| | - Quan Zhang
- Oxford Centre for Diabetes, Endocrinology and Metabolism, Churchill Hospital, University of Oxford, Headington, U.K
| | - Albert Salehi
- Institute of Neuroscience of Physiology, Department of Physiology, Metabolic Research Unit, University of Göteborg, Göteborg, Sweden
| | - Mara Willems
- Oxford Centre for Diabetes, Endocrinology and Metabolism, Churchill Hospital, University of Oxford, Headington, U.K
| | - Jakob G Knudsen
- Oxford Centre for Diabetes, Endocrinology and Metabolism, Churchill Hospital, University of Oxford, Headington, U.K
| | - Anna K Ringgaard
- Diabetes Research, Department of Stem Cell Biology, Novo Nordisk A/S, Måløv, Denmark
- Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Caroline E Chapman
- Oxford Centre for Diabetes, Endocrinology and Metabolism, Churchill Hospital, University of Oxford, Headington, U.K
| | - Alejandro Gonzalez-Alvarez
- Oxford Centre for Diabetes, Endocrinology and Metabolism, Churchill Hospital, University of Oxford, Headington, U.K
| | - Nicoletta C Surdo
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, U.K
| | - Manuela Zaccolo
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, U.K
| | - Davide Basco
- Center for Integrative Genomics, Université de Lausanne, Lausanne, Switzerland
| | - Paul R V Johnson
- Oxford Centre for Diabetes, Endocrinology and Metabolism, Churchill Hospital, University of Oxford, Headington, U.K
- Oxford National Institute for Health Research, Biomedical Research Centre, Oxford, U.K
| | - Reshma Ramracheya
- Oxford Centre for Diabetes, Endocrinology and Metabolism, Churchill Hospital, University of Oxford, Headington, U.K
| | - Guy A Rutter
- Section of Cell Biology and Functional Genomics, Department of Medicine, Imperial College London, London, U.K
| | - Antony Galione
- Department of Pharmacology, University of Oxford, Oxford, U.K
| | - Patrik Rorsman
- Oxford Centre for Diabetes, Endocrinology and Metabolism, Churchill Hospital, University of Oxford, Headington, U.K.
- Institute of Neuroscience of Physiology, Department of Physiology, Metabolic Research Unit, University of Göteborg, Göteborg, Sweden
- Oxford National Institute for Health Research, Biomedical Research Centre, Oxford, U.K
| | - Andrei I Tarasov
- Oxford Centre for Diabetes, Endocrinology and Metabolism, Churchill Hospital, University of Oxford, Headington, U.K.
- Oxford National Institute for Health Research, Biomedical Research Centre, Oxford, U.K
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25
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Abstract
The ultrastructural evaluation of the early alterations adriamycin-induced on cultured mice heart cells is reported. The major effects are hypertrophy of the sarcoplasmic reticulum and a market increase of the number and total extension of the gap junctions. These findings are discussed in the light of the information available in the literature.
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26
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Lambertenghi-Deliliers G, Zanon PL, Pozzoli EF, Bellini O. Myocardial Injury Induced by a Single Dose of Adriamycin: An Electron Microscopic Study. Tumori 2018; 62:517-28. [PMID: 1020054 DOI: 10.1177/030089167606200506] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Adriamycin cardiomyopathy has been studied under the electron microscope using myocardial ventricular cells of CRF mice, previously treated with 10 mg/kg body weight of the drug given in a single intravenous injection. Within 10 min myocardial cell nucleoli show a nucleolonema fragmentation, and during the following 3 hours they acquire the nucleolar segregation pattern. Fourteen hours after drug injection, nucleolar morphology again becomes normal, while areas of focal degeneration, characterized by damaged mitochondria and enlarged smooth reticulum cisternae, appear in the sarcoplasm. One to 3 days later the degeneration process involves the myofibrillar component, and after 50 days the great majority of myocardial ventricular cells is damaged. The early appearance and the functional significance of nucleolar segregation support the hypothesis that adriamycin cardiotoxicity might be dependent on its ability to bind to myocardial cell DNA. The consequent failure of UNA and protein synthesis, impairing the continuous renewal of myofibrillar and mitochondrial components of the cell, might explain the progressive myocardial damage.
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27
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Lambertenghi-Deliliers G, Zanon PL, Pozzoli EF, Bellini O, Praga C. Ultrastructural Alterations of Atrial Myocardium Induced by Adriamycin in Chronically Treated Animals. Tumori 2018; 64:15-24. [PMID: 565963 DOI: 10.1177/030089167806400102] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The clinical use of adriamycin (AM) is limited by a possible dose-dependent myocardiopathy. Severe lesions of ventricular myocardium widely described by electron microscopy have been correlated to irreversible congestive heart failure. On the other hand, the atrial contractile elements which differ from the ventricular ones because of the presence of the so-called specific granules have rarely been considered. In the work described in this paper, adriamycin was injected into rabbits and mice according to schedules of chronic toxicity. At the end of the treatment the atrial myocells presented diffuse ultrastructural lesions of mitochondria, sarcoplasmic reticulum and myofibrillar bundles. These alterations might be caused by the ribonucleoprotein synthesis inhibition, by a direct drug toxicity or by an energetic crisis due to early mitochondrial lesions. Besides, adriamycin produces a decrease of the specific atrial granules that play a hypothetic role in the metabolism of myocardial cells. However, lack of information about the contents and the exact function of atrial granules does not allow us to conclude that their decrease in treated animals has a pathogenetic significance in myocardiopathy induced by adriamycin.
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28
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Venturi E, Lindsay C, Lotteau S, Yang Z, Steer E, Witschas K, Wilson AD, Wickens JR, Russell AJ, Steele D, Calaghan S, Sitsapesan R. Simvastatin activates single skeletal RyR1 channels but exerts more complex regulation of the cardiac RyR2 isoform. Br J Pharmacol 2018; 175:938-952. [PMID: 29278865 PMCID: PMC5825303 DOI: 10.1111/bph.14136] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2017] [Revised: 11/23/2017] [Accepted: 12/13/2017] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND AND PURPOSE Statins are amongst the most widely prescribed drugs for those at risk of cardiovascular disease, lowering cholesterol levels by inhibiting 3-hydroxy-3-methylglutaryl (HMG)-CoA reductase. Although effective at preventing cardiovascular disease, statin use is associated with muscle weakness, myopathies and, occasionally, fatal rhabdomyolysis. As simvastatin, a commonly prescribed statin, promotes Ca2+ release from sarcoplasmic reticulum (SR) vesicles, we investigated if simvastatin directly activates skeletal (RyR1) and cardiac (RyR2) ryanodine receptors. EXPERIMENTAL APPROACH RyR1 and RyR2 single-channel behaviour was investigated after incorporation of sheep cardiac or mouse skeletal SR into planar phospholipid bilayers under voltage-clamp conditions. LC-MS was used to monitor the kinetics of interconversion of simvastatin between hydroxy-acid and lactone forms during these experiments. Cardiac and skeletal myocytes were permeabilised to examine simvastatin modulation of SR Ca2+ release. KEY RESULTS Hydroxy acid simvastatin (active at HMG-CoA reductase) significantly and reversibly increased RyR1 open probability (Po) and shifted the distribution of Ca2+ spark frequency towards higher values in skeletal fibres. In contrast, simvastatin reduced RyR2 Po and shifted the distribution of spark frequency towards lower values in ventricular cardiomyocytes. The lactone pro-drug form of simvastatin (inactive at HMG-CoA reductase) also activated RyR1, suggesting that the HMG-CoA inhibitor pharmacophore was not responsible for RyR1 activation. CONCLUSION AND IMPLICATIONS Simvastatin interacts with RyR1 to increase SR Ca2+ release and thus may contribute to its reported adverse effects on skeletal muscle. The ability of low concentrations of simvastatin to reduce RyR2 Po may also protect against Ca2+ -dependent arrhythmias and sudden cardiac death.
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Affiliation(s)
- Elisa Venturi
- Department of PharmacologyUniversity of OxfordOxfordUK
| | - Chris Lindsay
- Department of PharmacologyUniversity of OxfordOxfordUK
- Department of Chemistry, Chemistry Research LaboratoryUniversity of OxfordOxfordUK
| | | | - Zhaokang Yang
- School of Biomedical SciencesUniversity of LeedsLeedsUK
| | - Emma Steer
- School of Biomedical SciencesUniversity of LeedsLeedsUK
| | | | | | - James R Wickens
- Department of Chemistry, Chemistry Research LaboratoryUniversity of OxfordOxfordUK
| | - Angela J Russell
- Department of PharmacologyUniversity of OxfordOxfordUK
- Department of Chemistry, Chemistry Research LaboratoryUniversity of OxfordOxfordUK
| | - Derek Steele
- School of Biomedical SciencesUniversity of LeedsLeedsUK
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29
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Nozdrenko DM, Miroshnychenko MS, Soroca VM, Korchins ka LV, Zavodovskiy DO. The effect of chlorpyrifos upon ATPase activity of sarcoplasmic reticulum and biomechanics of skeleta l muscle contraction. Ukr Biochem J 2018; 88:82-8. [PMID: 29227609 DOI: 10.15407/ubj88.02.082] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
We investigated the effect of chlorpyrifos, an organophosphate insecticide, on Ca2+,Mg2+-ATPase
activity of sarcoplasmic reticulum and on contraction dynamics (force and length changes) of Rana temporaria
m. tibialis anterior muscle fiber bundles. All of the used concentrations of chlorpyrifos (10-6 to 10-5 M) caused
decrease of Ca2+,Mg2+-ATPase activity. The inhibition of Ca2+,Mg2+-ATPase activity by chlorpyriphos in
concentrations of 10-6 M to 7.5·10-6 M is due to permeation of sarcoplasmic reticulum rather than due to
direct enzyme inhibition by organophosphate insecticides. The inhibitory properties of the compound were
higher at increased concentration and exposure timeframes. Chlorpyrifos in concentration range of 10-6
to 7.5·10-6 M causes changes in muscle fiber response force that were more pronounced than changes in
contractile length. We demonstrated inhibition of Ca2+,Mg2+-ATPase activity caused by noncholinergic
effects of chlorpyriphos. It is possible to conclude that influence of organophosphate insecticides happens
not only in the neuromuscular transmission but also on the level of subcellular structures.
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30
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Ko CY, Liu MB, Song Z, Qu Z, Weiss JN. Multiscale Determinants of Delayed Afterdepolarization Amplitude in Cardiac Tissue. Biophys J 2017; 112:1949-1961. [PMID: 28494965 DOI: 10.1016/j.bpj.2017.03.006] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2016] [Revised: 03/02/2017] [Accepted: 03/06/2017] [Indexed: 11/17/2022] Open
Abstract
Spontaneous calcium (Ca) waves in cardiac myocytes underlie delayed afterdepolarizations (DADs) that trigger cardiac arrhythmias. How these subcellular/cellular events overcome source-sink factors in cardiac tissue to generate DADs of sufficient amplitude to trigger action potentials is not fully understood. Here, we evaluate quantitatively how factors at the subcellular scale (number of Ca wave initiation sites), cellular scale (sarcoplasmic reticulum (SR) Ca load), and tissue scale (synchrony of Ca release in populations of myocytes) determine DAD features in cardiac tissue using a combined experimental and computational modeling approach. Isolated patch-clamped rabbit ventricular myocytes loaded with Fluo-4 to image intracellular Ca were rapidly paced during exposure to elevated extracellular Ca (2.7 mmol/L) and isoproterenol (0.25 μmol/L) to induce diastolic Ca waves and subthreshold DADs. As the number of paced beats increased from 1 to 5, SR Ca content (assessed with caffeine pulses) increased, the number of Ca wave initiation sites increased, integrated Ca transients and DADs became larger and shorter in duration, and the latency period to the onset of Ca waves shortened with reduced variance. In silico analysis using a computer model of ventricular tissue incorporating these experimental measurements revealed that whereas all of these factors promoted larger DADs with higher probability of generating triggered activity, the latency period variance and SR Ca load had the greatest influences. Therefore, incorporating quantitative experimental data into tissue level simulations reveals that increased intracellular Ca promotes DAD-mediated triggered activity in tissue predominantly by increasing both the synchrony (decreasing latency variance) of Ca waves in nearby myocytes and SR Ca load, whereas the number of Ca wave initiation sites per myocyte is less important.
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Affiliation(s)
- Christopher Y Ko
- Division of Cardiology, Department of Medicine, UCLA Cardiovascular Research Laboratory, University of California, Los Angeles, California
| | - Michael B Liu
- Division of Cardiology, Department of Medicine, UCLA Cardiovascular Research Laboratory, University of California, Los Angeles, California
| | - Zhen Song
- Division of Cardiology, Department of Medicine, UCLA Cardiovascular Research Laboratory, University of California, Los Angeles, California
| | - Zhilin Qu
- Division of Cardiology, Department of Medicine, UCLA Cardiovascular Research Laboratory, University of California, Los Angeles, California; Department of Biomathematics, David Geffen School of Medicine, University of California, Los Angeles, California
| | - James N Weiss
- Division of Cardiology, Department of Medicine, UCLA Cardiovascular Research Laboratory, University of California, Los Angeles, California; Department of Physiology, David Geffen School of Medicine, University of California, Los Angeles, California.
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31
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Ma S, Liu L, Ma Z, Zhang X. Microstructural and ultrastructural changes in the muscle cells of the oriental armyworm Mythimna separata Walker (Lepidoptera: Noctuidae) on treatment with wilforine. Pestic Biochem Physiol 2017; 139:60-67. [PMID: 28595923 DOI: 10.1016/j.pestbp.2017.05.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2017] [Revised: 04/26/2017] [Accepted: 05/01/2017] [Indexed: 06/07/2023]
Abstract
This study investigated the mode of action of wilforine, an alkaloid with insecticidal properties, extracted from Tripterygium wilfordii Hook f., on the microstructure and ultrastructure of the muscle cells of larvae and adults of the oriental armyworm Mythimna separata Walker. The bioassay results showed that wilforine had oral toxicity against both M. separata larvae (LC50=63μg/mL) and adults (LC50=36μg/mL). The typical toxicity sign was paralysis leading to death. Both light and electron microscope observations revealed that damage to the muscle cells increased with poisoning time in larvae and adults treated with the LC80 dose of wilforine. Histopathological examinations in the muscle cells of M. separata adults showed that there were large cytoplasmic spaces, disrupted Z-lines and swollen mitochondria in the muscle cells. Further, the sarcoplasmic reticulum was excessively dilated and fragmented; the nuclear membrane was ruptured; nuclear material was overflowing; and the myolemma was damaged. The similar pathological changes in the muscle cells of oriental armyworm larvae were observed, as above. In addition, a medullary sheath structure appeared and crystalline inclusion was also observed in the muscle cells of M. separata larvae. In conclusion, wilforine could induce pathological changes in the muscle cells of oriental armyworm larvae and adults, leading to their death; thus, the active site of action of wilforine maybe located in the muscle tissue of insects.
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Affiliation(s)
- Shujie Ma
- Research & Development Center of Biorational Pesticide, Northwest A & F University, Yangling 712100, PR China
| | - Lin Liu
- Research & Development Center of Biorational Pesticide, Northwest A & F University, Yangling 712100, PR China
| | - Zhiqing Ma
- Research & Development Center of Biorational Pesticide, Northwest A & F University, Yangling 712100, PR China.
| | - Xing Zhang
- Research & Development Center of Biorational Pesticide, Northwest A & F University, Yangling 712100, PR China
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Lu LH, Li C, Wang QY, Zhang Q, Zhang Y, Meng H, Wang Y, Wang W. Cardioprotective effects of Qishen Granule () on sarcoplasmic reticulum Ca 2+ handling in heart failure rats. Chin J Integr Med 2017; 23:510-517. [PMID: 28497395 DOI: 10.1007/s11655-017-2809-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2013] [Indexed: 12/22/2022]
Abstract
OBJECTIVE To assess the effects of Qishen Granule (, QSG) on sarcoplasmic reticulum (SR) Ca2+ handling in heart failure (HF) model of rats and to explore the underlying molecular mechanisms. METHODS HF rat models were induced by left anterior descending coronary artery ligation surgery and high-fat diet feeding. Rats were randomly divided into sham (n=10), model (n=10), QSG (n=12, 2.2 g/kg daily) and metoprolol groups (n=12, 10.5 mg/kg daily). The therapeutic effects of QSG were evaluated by echocardiography and blood lipid testing. Intracellular Ca2+ concentration and sarco-endoplasmic reticulum ATPase 2a (SERCA2a) activity were detected by specifific assay kits. Expressions of the critical regulators in SR Ca2+ handling were evaluated by Western blot and real-time quantitative polymerase chain reaction. RESULTS HF model of rats developed ventricular remodeling accompanied with calcium overload and defective Ca2+ release-uptake cycling in cardiomyocytes. Treatment with QSG improved contractive function, attenuated ventricular remodeling and reduced the basal intracellular Ca2+ level. QSG prevented defective Ca2+ leak by attenuating hyperphosphorylation of ryanodine receptor 2, inhibiting expression of protein kinase A and up-regulating transcriptional expression of protein phosphatase 1. QSG also restored Ca2+ uptake by up-regulating expression and activity of SERCA2a and promoting phosphorylation of phospholamban. CONCLUSION QSG restored SR Ca2+ cycling in HF rats and served as an ideal alternative drug for treating HF.
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Affiliation(s)
- Ling-Hui Lu
- School of Preclinical Medicine, Beijing University of Chinese Medicine, Beijing, 100029, China
| | - Chun Li
- Modern Research Center for Traditional Chinese Medicine, Beijing University of Chinese Medicine, Beijing, 100029, China
| | - Qi-Yan Wang
- School of Life Sciences, Beijing University of Chinese Medicine, Beijing, 100029, China
| | - Qian Zhang
- School of Preclinical Medicine, Beijing University of Chinese Medicine, Beijing, 100029, China
| | - Yi Zhang
- Modern Research Center for Traditional Chinese Medicine, Beijing University of Chinese Medicine, Beijing, 100029, China
- School of Chinese Materia Medica, Beijing University of Chinese Medicine, Beijing, 100102, China
| | - Hui Meng
- Modern Research Center for Traditional Chinese Medicine, Beijing University of Chinese Medicine, Beijing, 100029, China
- School of Chinese Materia Medica, Beijing University of Chinese Medicine, Beijing, 100102, China
| | - Yong Wang
- School of Life Sciences, Beijing University of Chinese Medicine, Beijing, 100029, China
| | - Wei Wang
- School of Preclinical Medicine, Beijing University of Chinese Medicine, Beijing, 100029, China.
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Hwang HR, Tai BY, Cheng PY, Chen PN, Sung PJ, Wen ZH, Hsu CH. Excavatolide B Modulates the Electrophysiological Characteristics and Calcium Homeostasis of Atrial Myocytes. Mar Drugs 2017; 15:md15020025. [PMID: 28125029 PMCID: PMC5334606 DOI: 10.3390/md15020025] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2016] [Revised: 01/10/2017] [Accepted: 01/18/2017] [Indexed: 12/19/2022] Open
Abstract
Severe bacterial infections caused by sepsis always result in profound physiological changes, including fever, hypotension, arrhythmia, necrosis of tissue, systemic multi-organ dysfunction, and finally death. The lipopolysaccharide (LPS) provokes an inflammatory response under sepsis, which may increase propensity to arrhythmogenesis. Excavatolide B (EXCB) possesses potent anti-inflammatory effects. However, it is not clear whether EXCB could modulate the electrophysiological characteristics and calcium homeostasis of atrial myocytes. This study investigated the effects of EXCB on the atrial myocytes exposed to lipopolysaccharide. A whole-cell patch clamp and indo-1 fluorimetric ratio technique was employed to record the action potential (AP), ionic currents, and intracellular calcium ([Ca2+]i) in single, isolated rabbit left atrial (LA) cardiomyocytes, with and without LPS (1 μg/mL) and LPS + EXCB administration (10 μM) for 6 ± 1 h, in order to investigate the role of EXCB on atrial electrophysiology. In the presence of LPS, EXCB-treated LA myocytes (n = 13) had a longer AP duration at 20% (29 ± 2 vs. 20 ± 2 ms, p < 0.05), 50% (52 ± 4 vs. 40 ± 3 ms, p < 0.05), and 90% (85 ± 5 vs. 68 ± 3 ms, p < 0.05), compared to the LPS-treated cells (n = 12). LPS-treated LA myocytes showed a higher late sodium current, Na+/Ca2+ exchanger current, transient outward current, and delayed rectifier potassium current, but a lower l-type Ca2+ current, than the control LA myocytes. Treatment with EXCB reversed the LPS-induced alterations of the ionic currents. LPS-treated, EXCB-treated, and control LA myocytes exhibited similar Na+ currents. In addition, the LPS-treated LA myocytes exhibited a lower [Ca2+]i content and higher sarcoplasmic reticulum calcium content, than the controls. EXCB reversed the LPS-induced calcium alterations. In conclusion, EXCB modulates LPS-induced LA electrophysiological characteristics and calcium homeostasis, which may contribute to attenuating LPS-induced arrhythmogenesis.
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Affiliation(s)
- Hwong-Ru Hwang
- Department of Marine Biotechnology and Resources, National Sun Yat-sen University, Kaohsiung 804, Taiwan.
- Division of Cardiology, Department of Medicine, E-Da Hospital, Kaohsiung 824, Taiwan.
- Division of Cardiology, Department of Internal Medicine, Kaohsiung Veterans General Hospital, Kaohsiung 813, Taiwan.
| | - Buh-Yuan Tai
- Department of Marine Biotechnology and Resources, National Sun Yat-sen University, Kaohsiung 804, Taiwan.
- Department of Traditional Medicine, Jianan Mental Hospital, Tainan 717, Taiwan.
| | - Pao-Yun Cheng
- Department of Physiology and Biophysics and Graduate Institute of Physiology, National Defense Medical Center, Taipei 114, Taiwan.
| | - Ping-Nan Chen
- Department of Biomedical Engineering, National Defense Medical Center, Taipei 114, Taiwan.
| | - Ping-Jyun Sung
- National Museum of Marine Biology and Aquarium, Pingtung 944, Taiwan.
- Chinese Medicine Research and Development Center, China Medical University Hospital, Taichung 404, Taiwan.
- Graduate Institute of Natural Products, Kaohsiung Medical University, Kaohsiung 807, Taiwan.
| | - Zhi-Hong Wen
- Department of Marine Biotechnology and Resources, National Sun Yat-sen University, Kaohsiung 804, Taiwan.
- Doctoral Degree Program in Marine Biotechnology, National Sun Yat-Sen University and Academia Sinica, Kaohsiung 804, Taiwan.
| | - Chih-Hsueng Hsu
- Division of Cardiology, Tri-Service General Hospital, National Defense Medical Center, Taipei 114, Taiwan.
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Scudeler EL, Garcia ASG, Pinheiro PFF, Santos DCD. Neem oil (Azadirachta indica A. Juss) affects the ultrastructure of the midgut muscle of Ceraeochrysa claveri (Navás, 1911) (Neuroptera: Chrysopidae). Acta Histochem 2017; 119:84-91. [PMID: 27939524 DOI: 10.1016/j.acthis.2016.11.012] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2016] [Revised: 11/29/2016] [Accepted: 11/29/2016] [Indexed: 01/31/2023]
Abstract
Cytomorphological changes, by means of ultrastructural analyses, have been used to determine the effects of the biopesticide neem oil on the muscle fibers of the midgut of the predator Ceraeochrysa claveri. Insects, throughout the larval period, were fed eggs of Diatraea saccharalis treated with neem oil at a concentration of 0.5%, 1% or 2%. In the adult stage, the midgut was collected from female insects at two stages of adulthood (newly emerged and at the start of oviposition) and processed for ultrastructural analyses. In the newly emerged insects obtained from neem oil treatments, muscle fibers showed a reduction of myofilaments as well as swollen mitochondria and an accumulation of membranous structures. Muscular fibers responded to those cellular injuries with the initiation of detoxification mechanisms, in which acid phosphatase activity was observed in large vesicles located at the periphery of the muscle fiber. At the start of oviposition in the neem oil treated insects, muscle fibers exhibited signs of degeneration, containing vacant areas in which contractile myofilaments were reduced or completely absent, and an accumulation of myelin structures, a dilatation of cisternae of sarcoplasmic reticulum, and mitochondrial swelling and cristolysis were observed. Enzymatic activity for acid phosphatase was present in large vesicles, indicating that mechanisms of lytic activity during the cell injury were utilized but insufficient for recovery from all the cellular damage. The results indicate that the visceral muscle layer is also the target of action of neem oil, and the cytotoxic effects observed may compromise the function of that organ.
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Affiliation(s)
- Elton Luiz Scudeler
- Laboratory of Insects, Department of Morphology, Institute of Biosciences of Botucatu, UNESP - São Paulo State University, Botucatu, SP, Brazil.
| | - Ana Silvia Gimenes Garcia
- Laboratory of Insects, Department of Morphology, Institute of Biosciences of Botucatu, UNESP - São Paulo State University, Botucatu, SP, Brazil.
| | | | - Daniela Carvalho Dos Santos
- Laboratory of Insects, Department of Morphology, Institute of Biosciences of Botucatu, UNESP - São Paulo State University, Botucatu, SP, Brazil.
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Zhang Y, Zhou H, Wu W, Shi C, Hu S, Yin T, Ma Q, Han T, Zhang Y, Tian F, Chen Y. Liraglutide protects cardiac microvascular endothelial cells against hypoxia/reoxygenation injury through the suppression of the SR-Ca(2+)-XO-ROS axis via activation of the GLP-1R/PI3K/Akt/survivin pathways. Free Radic Biol Med 2016; 95:278-92. [PMID: 27038735 DOI: 10.1016/j.freeradbiomed.2016.03.035] [Citation(s) in RCA: 142] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/31/2016] [Revised: 03/04/2016] [Accepted: 03/29/2016] [Indexed: 01/15/2023]
Abstract
Microvascular endothelial cells (CMECs) oxidative damage resulting from hypoxia/reoxygenation (H/R) injury is responsible for microcirculation perfusion disturbances and the progression of cardiac dysfunction. However, few strategies are available to reverse such pathologies. Here, we studied the effects and mechanisms of liraglutide on CEMCs oxidative damage, focusing in particular on calcium overload-triggered free radical injury signals and the GLP-1R/PI3K/Akt/survivin survival pathways. The results indicate that H/R increased IP3R expression but reduced SERCA2a expression, which rapidly raised intracellular Ca(2+) levels, subsequently leading to Ca(2+)-dependent xanthine oxidase (XO) activation, reactive oxygen species (ROS) production and the cellular apoptosis of CMECs. However, liraglutide pretreatment abrogated Ca(2+)-mediated oxidative apoptosis. Furthermore, liraglutide regulated the rate of IP3R/SERCA2a gene transcription and conserved SERCA2a-ATPase activity via the maintenance of ATP production under H/R, which drove excessive Ca(2+) reflux to the sarcoplasmic reticulum (SR) and inhibited Ca(2+) release from the SR, ultimately restoring Ca(2+) homeostasis. Furthermore, the regulatory role of liraglutide on Ca(2+) balance in conjunction with its up-regulation of superoxide dismutase, glutathione and glutathione peroxidase collectively scavenged the excess ROS under H/R. Moreover, we showed that liraglutide strengthened Akt phosphorylation and subsequently survivin expression. In addition, both the blockade of the GLP-1R/PI3K/Akt pathways and the siRNA-mediated knockdown of survivin abolished the protective effects of liraglutide on SR-Ca(2+) function and CMECs oxidative apoptosis. In summary, this study confirmed that H/R induced CMECs oxidative damage through the SR-Ca(2+)-XO-ROS injury signals and that liraglutide pretreatment may suppress such CMECs damage through the PI3K/Akt/survivin pathways.
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Affiliation(s)
- Ying Zhang
- Department of Cardiology, Chinese PLA General Hospital, #28 Fuxing Road, Beijing 100853, China
| | - Hao Zhou
- Department of Cardiology, Chinese PLA General Hospital, #28 Fuxing Road, Beijing 100853, China
| | - Wenbo Wu
- Department of Burn surgery and Plastic surgery, First Hospital Affiliated to the Chinese PLA General Hospital, Beijing, China
| | - Chen Shi
- Department of Radiotherapy, Beijing Cancer Hospital, Beijing, China
| | - Shunying Hu
- Department of Cardiology, Chinese PLA General Hospital, #28 Fuxing Road, Beijing 100853, China
| | - Tong Yin
- Department of Cardiology, Chinese PLA General Hospital, #28 Fuxing Road, Beijing 100853, China
| | - Qiang Ma
- Department of Cardiology, Chinese PLA General Hospital, #28 Fuxing Road, Beijing 100853, China
| | - Tianwen Han
- Department of Cardiology, Chinese PLA General Hospital, #28 Fuxing Road, Beijing 100853, China
| | - Yingqian Zhang
- Department of Cardiology, Chinese PLA General Hospital, #28 Fuxing Road, Beijing 100853, China
| | - Feng Tian
- Department of Cardiology, Chinese PLA General Hospital, #28 Fuxing Road, Beijing 100853, China
| | - Yundai Chen
- Department of Cardiology, Chinese PLA General Hospital, #28 Fuxing Road, Beijing 100853, China.
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Huang JH, Chen YC, Lee TI, Kao YH, Chazo TF, Chen SA, Chen YJ. Glucagon-like peptide-1 regulates calcium homeostasis and electrophysiological activities of HL-1 cardiomyocytes. Peptides 2016; 78:91-8. [PMID: 26930508 DOI: 10.1016/j.peptides.2016.02.007] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/09/2015] [Revised: 02/18/2016] [Accepted: 02/23/2016] [Indexed: 12/25/2022]
Abstract
Glucagon like-peptide-1 (GLP-1) is an incretin hormone with antidiabetic effects through stimulating insulin secretion, β cell neogenesis, satiety sensation, and inhibiting glucagon secretion. Administration of GLP-1 provides cardioprotective effects through attenuating cardiac inflammation and insulin resistance. GLP-1 also modulates the heart rate and systolic pressure, which suggests that GLP-1 may have cardiac electrical effects. Therefore, the purposes of this study were to evaluate whether GLP-1 has direct cardiac effects and identify the underlying mechanisms. Patch clamp, confocal microscopy with Fluo-3 fluorescence, and Western blot analyses were used to evaluate the electrophysiological characteristics, calcium homeostasis, and calcium regulatory proteins in HL-1 atrial myocytes with and without GLP-1 (1 and 10nM) incubation for 24h. GLP-1 (1 and 10nM) and control cells had similar action potential durations. However, GLP-1 at 10nM significantly increased calcium transients and sarcoplasmic reticular Ca(2+) contents. Compared to the control, GLP-1 (10nM)-treated cells significantly decreased phosphorylation of the ryanodine receptor at S2814 and total phospholamban, but there were similar protein levels of sarcoplasmic reticular Ca(2+)-ATPase and the sodium-calcium exchanger. Moreover, exendin (9-39) amide (a GLP-1 receptor antagonist, 10nM) attenuated GLP-1-mediated effects on total SR content and phosphorylated ryanodine receptor S2814. This study demonstrates GLP-1 may regulate HL-1 cell arrhythmogenesis through modulating calcium handling proteins.
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Affiliation(s)
- Jen-Hung Huang
- Division of Cardiovascular Medicine, Department of Internal Medicine, Wan Fang Hospital, Taipei Medical University, Taipei, Taiwan; Department of Internal Medicine, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan
| | - Yao-Chang Chen
- Department of Biomedical Engineering, National Defense Medical Center, Taipei, Taiwan
| | - Ting-I Lee
- Division of Endocrinology and Metabolism, Wan Fang Hospital, Taipei Medical University, Taipei, Taiwan
| | - Yu-Hsun Kao
- Graduate Institute of Clinical Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan; Department of Medical Education and Research, Wan Fang Hospital, Taipei Medical University, Taipei, Taiwan.
| | - Tze-Fan Chazo
- Division of Cardiology and Cardiovascular Research Center, Taipei Veterans General Hospital, Taipei, Taiwan
| | - Shih-Ann Chen
- Division of Cardiology and Cardiovascular Research Center, Taipei Veterans General Hospital, Taipei, Taiwan; National Yang-Ming University, School of Medicine, Taipei, Taiwan
| | - Yi-Jen Chen
- Division of Cardiovascular Medicine, Department of Internal Medicine, Wan Fang Hospital, Taipei Medical University, Taipei, Taiwan; Graduate Institute of Clinical Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan.
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Veklich TO. The inhibitory influence of calix[4]Arene of C-90 on the activity of Ca2+,Mg2+-ATPases in plasma membrane and sarcoplasmic reticulum in myometrium cells. Ukr Biochem J 2016; 88:5-15. [PMID: 29227596 DOI: 10.15407/ubj88.02.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Our study on the plasma membrane vesicles and myometrium cells treated with 0.1% digitonin showed
that inhibitory effect of calix[4]arene C-90 (5,11,17,23-tetra(trifluoro)methyl(phenylsulphonylimino)-methylamino-
25,26,27,28-tetrapropoxy-calix[4]arene) on the plasma membrane Ca2+,Mg2+-ATPase was more significant
than on the Ca2+,Mg2+-ATPase in sarcoplasmic reticulum (the inhibition coefficient I0.5 values were
20.2 ± 0.5 μM and 57.0 ± 1.4 μM for the plasma membrane Ca2+,Mg2+-ATPase and Ca2+,Mg2+-ATPase in
sarcoplasmic reticulum, respectively (n = 5)). Inhibition kinetics of calix[4]arene C-90 effect on the Ca2+,Mg2+-
ATPase activities in plasma membrane and sarcoplasmic reticulum were studied. This substance inhibited
both pumps as complete noncompetitive inhibitor. Calix[4]arene C-90 caused the increase of intracellular
Ca2+ concentration and decrease of hydrodynamic diameter in smooth muscle cells similar to the action of
uterotonic drug oxytocin.
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Nozdrenko DM, Abramchuk OM, Soroca VM, Miroshnichenko NS. ALUMINUM CHLORIDE EFFECT ON Ca2+,Mg(2+)-ATPase ACTIVITY AND DYNAMIC PARAMETERS OF SKELETAL MUSCLE CONTRACTION. Ukr Biochem J 2016; 87:38-45. [PMID: 26717594 DOI: 10.15407/ubj87.05.038] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
We studied enzymatic activity and measured strain-gauge contraction properties of the frog Rana temporaria m. tibialis anterior muscle fascicles during the action of aluminum chloride solution. It was shown that AlCl3 solutions did not affect the dynamic properties of skeletal muscle preparation in concentrations less than 10(-4) M Increasing the concentration of AlCl3 to 10(-2) M induce complete inhibition of muscle contraction. A linear correlation between decrease in Ca2+,Mg(2+)-ATPase activity of sarcoplasmic reticulum and the investigated concentrations range of aluminum chloride was observed. The reduction in the dynamic contraction performance and the decrease Ca2+,Mg(2+)-ATPase activity of the sarcoplasmic reticulum under the effect of the investigated AlCl3 solution were minimal in pre-tetanus period of contraction.
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Funai K, Lodhi IJ, Spears LD, Yin L, Song H, Klein S, Semenkovich CF. Skeletal Muscle Phospholipid Metabolism Regulates Insulin Sensitivity and Contractile Function. Diabetes 2016; 65:358-70. [PMID: 26512026 PMCID: PMC4747455 DOI: 10.2337/db15-0659] [Citation(s) in RCA: 82] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/18/2015] [Accepted: 10/19/2015] [Indexed: 12/18/2022]
Abstract
Skeletal muscle insulin resistance is an early defect in the development of type 2 diabetes. Lipid overload induces insulin resistance in muscle and alters the composition of the sarcoplasmic reticulum (SR). To test the hypothesis that skeletal muscle phospholipid metabolism regulates systemic glucose metabolism, we perturbed choline/ethanolamine phosphotransferase 1 (CEPT1), the terminal enzyme in the Kennedy pathway of phospholipid synthesis. In C2C12 cells, CEPT1 knockdown altered SR phospholipid composition and calcium flux. In mice, diet-induced obesity, which decreases insulin sensitivity, increased muscle CEPT1 expression. In high-fat diet-fed mice with skeletal muscle-specific knockout of CEPT1, systemic and muscle-based approaches demonstrated increased muscle insulin sensitivity. In CEPT1-deficient muscles, an altered SR phospholipid milieu decreased sarco/endoplasmic reticulum Ca(2+) ATPase-dependent calcium uptake, activating calcium-signaling pathways known to improve insulin sensitivity. Altered muscle SR calcium handling also rendered these mice exercise intolerant. In obese humans, surgery-induced weight loss increased insulin sensitivity and decreased skeletal muscle CEPT1 protein. In obese humans spanning a spectrum of metabolic health, muscle CEPT1 mRNA was inversely correlated with insulin sensitivity. These results suggest that high-fat feeding and obesity induce CEPT1, which remodels the SR to preserve contractile function at the expense of insulin sensitivity.
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Affiliation(s)
- Katsuhiko Funai
- Division of Endocrinology, Metabolism and Lipid Research, Washington University in St. Louis School of Medicine, St. Louis, MO Departments of Kinesiology and Physiology, East Carolina University, Greenville, NC
| | - Irfan J Lodhi
- Division of Endocrinology, Metabolism and Lipid Research, Washington University in St. Louis School of Medicine, St. Louis, MO
| | - Larry D Spears
- Division of Endocrinology, Metabolism and Lipid Research, Washington University in St. Louis School of Medicine, St. Louis, MO
| | - Li Yin
- Division of Endocrinology, Metabolism and Lipid Research, Washington University in St. Louis School of Medicine, St. Louis, MO
| | - Haowei Song
- Division of Endocrinology, Metabolism and Lipid Research, Washington University in St. Louis School of Medicine, St. Louis, MO
| | - Samuel Klein
- Division of Geriatrics and Nutritional Science, Washington University in St. Louis School of Medicine, St. Louis, MO
| | - Clay F Semenkovich
- Division of Endocrinology, Metabolism and Lipid Research, Washington University in St. Louis School of Medicine, St. Louis, MO Department of Cell Biology and Physiology, Washington University in St. Louis School of Medicine, St. Louis, MO
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Aureliano M. Decavanadate Toxicology and Pharmacological Activities: V10 or V1, Both or None? Oxid Med Cell Longev 2016; 2016:6103457. [PMID: 26904166 PMCID: PMC4745863 DOI: 10.1155/2016/6103457] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/26/2015] [Accepted: 12/24/2015] [Indexed: 02/07/2023]
Abstract
This review covers recent advances in the understanding of decavanadate toxicology and pharmacological applications. Toxicological in vivo studies point out that V10 induces several changes in several oxidative stress parameters, different from the ones observed for vanadate (V1). In in vitro studies with mitochondria, a particularly potent V10 effect, in comparison with V1, was observed in the mitochondrial depolarization (IC50 = 40 nM) and oxygen consumption (99 nM). It is suggested that mitochondrial membrane depolarization is a key event in decavanadate induction of necrotic cardiomyocytes death. Furthermore, only decavanadate species and not V1 potently inhibited myosin ATPase activity stimulated by actin (IC50 = 0.75 μM) whereas exhibiting lower inhibition activities for Ca(2+)-ATPase activity (15 μM) and actin polymerization (17 μM). Because both calcium pump and actin decavanadate interactions lead to its stabilization, it is likely that V10 interacts at specific locations with these proteins that protect against hydrolysis but, on the other hand, it may induce V10 reduction to oxidovanadium(IV). Putting it all together, it is suggested that the pharmacological applications of V10 species and compounds whose mechanism of action is still to be clarified might involve besides V10 and V1 also vanadium(IV) species.
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Affiliation(s)
- M. Aureliano
- 1Faculty of Sciences and Technology, University of Algarve, Campus of Gambelas, 8005-135 Faro, Portugal
- 2CCMar (Centre of Marine Sciences), University of Algarve, Campus of Gambelas, 8005-135 Faro, Portugal
- *M. Aureliano:
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Ollivier H, Marchant J, Le Bayon N, Servili A, Claireaux G. Calcium response of KCl-excited populations of ventricular myocytes from the European sea bass (Dicentrarchus labrax): a promising approach to integrate cell-to-cell heterogeneity in studying the cellular basis of fish cardiac performance. J Comp Physiol B 2015. [PMID: 26205950 DOI: 10.1007/s00360-015-0924-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Climate change challenges the capacity of fishes to thrive in their habitat. However, through phenotypic diversity, they demonstrate remarkable resilience to deteriorating conditions. In fish populations, inter-individual variation in a number of fitness-determining physiological traits, including cardiac performance, is classically observed. Information about the cellular bases of inter-individual variability in cardiac performance is scarce including the possible contribution of excitation-contraction (EC) coupling. This study aimed at providing insight into EC coupling-related Ca(2+) response and thermal plasticity in the European sea bass (Dicentrarchus labrax). A cell population approach was used to lay the methodological basis for identifying the cellular determinants of cardiac performance. Fish were acclimated at 12 and 22 °C and changes in intracellular calcium concentration ([Ca(2+)]i) following KCl stimulation were measured using Fura-2, at 12 or 22 °C-test. The increase in [Ca(2+)]i resulted primarily from extracellular Ca(2+) entry but sarcoplasmic reticulum stores were also shown to be involved. As previously reported in sea bass, a modest effect of adrenaline was observed. Moreover, although the response appeared relatively insensitive to an acute temperature change, a difference in Ca(2+) response was observed between 12- and 22 °C-acclimated fish. In particular, a greater increase in [Ca(2+)]i at a high level of adrenaline was observed in 22 °C-acclimated fish that may be related to an improved efficiency of adrenaline under these conditions. In conclusion, this method allows a rapid screening of cellular characteristics. It represents a promising tool to identify the cellular determinants of inter-individual variability in fishes' capacity for environmental adaptation.
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Affiliation(s)
| | - James Marchant
- Unité PFOM-ARN, LEMAR, Centre Ifremer de Brest, Plouzané, France
| | - Nicolas Le Bayon
- Unité PFOM-ARN, LEMAR, Centre Ifremer de Brest, Plouzané, France
| | - Arianna Servili
- Unité PFOM-ARN, LEMAR, Centre Ifremer de Brest, Plouzané, France
| | - Guy Claireaux
- Unité PFOM-ARN, LEMAR, Centre Ifremer de Brest, Plouzané, France
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Suita K, Fujita T, Hasegawa N, Cai W, Jin H, Hidaka Y, Prajapati R, Umemura M, Yokoyama U, Sato M, Okumura S, Ishikawa Y. Norepinephrine-Induced Adrenergic Activation Strikingly Increased the Atrial Fibrillation Duration through β1- and α1-Adrenergic Receptor-Mediated Signaling in Mice. PLoS One 2015. [PMID: 26203906 PMCID: PMC4512675 DOI: 10.1371/journal.pone.0133664] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
BACKGROUND Atrial fibrillation (AF) is the most common arrhythmias among old people. It causes serious long-term health problems affecting the quality of life. It has been suggested that the autonomic nervous system is involved in the onset and maintenance of AF in human. However, investigation of its pathogenesis and potential treatment has been hampered by the lack of suitable AF models in experimental animals. OBJECTIVES Our aim was to establish a long-lasting AF model in mice. We also investigated the role of adrenergic receptor (AR) subtypes, which may be involved in the onset and duration of AF. METHODS AND RESULTS Trans-esophageal atrial burst pacing in mice could induce AF, as previously shown, but with only a short duration (29.0 ± 8.1 sec). We found that adrenergic activation by intraperitoneal norepinephrine (NE) injection strikingly increased the AF duration. It increased the duration to more than 10 minutes, i.e., by more than 20-fold (656.2 ± 104.8 sec; P<0.001). In this model, a prior injection of a specific β1-AR blocker metoprolol and an α1-AR blocker prazosin both significantly attenuated NE-induced elongation of AF. To further explore the mechanisms underlying these receptors' effects on AF, we assessed the SR Ca(2+) leak, a major trigger of AF, and consequent spontaneous SR Ca(2+) release (SCR) in atrial myocytes. Consistent with the results of our in-vivo experiments, both metoprolol and prazosin significantly inhibited the NE-induced SR Ca(2+) leak and SCR. These findings suggest that both β1-AR and α1-AR may play important roles in the development of AF. CONCLUSIONS We have established a long-lasting AF model in mice induced by adrenergic activation, which will be valuable in future AF study using experimental animals, such as transgenic mice. We also revealed the important role of β1- and α1-AR-mediated signaling in the development of AF through in-vivo and in-vitro experiments.
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MESH Headings
- Adrenergic alpha-Antagonists/pharmacology
- Adrenergic beta-Antagonists/pharmacology
- Animals
- Atrial Fibrillation/chemically induced
- Atrial Fibrillation/physiopathology
- Calcium Signaling/drug effects
- Cells, Cultured
- Disease Models, Animal
- Heart Conduction System/drug effects
- Heart Conduction System/physiopathology
- Injections, Intraperitoneal
- Male
- Metoprolol/pharmacology
- Mice
- Mice, Inbred C57BL
- Myocytes, Cardiac/drug effects
- Myocytes, Cardiac/physiology
- Norepinephrine/administration & dosage
- Norepinephrine/toxicity
- Prazosin/pharmacology
- Receptors, Adrenergic, alpha-1/drug effects
- Receptors, Adrenergic, alpha-1/physiology
- Receptors, Adrenergic, beta-1/drug effects
- Receptors, Adrenergic, beta-1/physiology
- Sarcoplasmic Reticulum/drug effects
- Sympathetic Nervous System/drug effects
- Sympathetic Nervous System/physiopathology
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Affiliation(s)
- Kenji Suita
- Cardiovascular Research Institute, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Takayuki Fujita
- Cardiovascular Research Institute, Yokohama City University Graduate School of Medicine, Yokohama, Japan
- * E-mail: (TF); (YI)
| | - Nozomi Hasegawa
- Cardiovascular Research Institute, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Wenqian Cai
- Cardiovascular Research Institute, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Huiling Jin
- Cardiovascular Research Institute, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Yuko Hidaka
- Cardiovascular Research Institute, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Rajesh Prajapati
- Cardiovascular Research Institute, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Masanari Umemura
- Cardiovascular Research Institute, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Utako Yokoyama
- Cardiovascular Research Institute, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Motohiko Sato
- Cardiovascular Research Institute, Yokohama City University Graduate School of Medicine, Yokohama, Japan
- Department of Physiology, Aichi Medical University School of Medicine, Aichi, Japan
| | - Satoshi Okumura
- Cardiovascular Research Institute, Yokohama City University Graduate School of Medicine, Yokohama, Japan
- Department of Physiology, Tsurumi University School of Dental Medicine, Yokohama, Japan
| | - Yoshihiro Ishikawa
- Cardiovascular Research Institute, Yokohama City University Graduate School of Medicine, Yokohama, Japan
- * E-mail: (TF); (YI)
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Nozdrenko DM, Korchinska LV, Soroca VM. [ACTIVITY OF Ca2+,Mg(2+)-ATPase OF SARCOPLASMIC RETICULUM AND CONTRACTION STRENGTH OF THE FROG SKELETAL MUSCLES UNDER THE EFFECT OF ORGANOPHOSPHORUS INSECTICIDES]. Ukr Biochem J 2015; 87:63-69. [PMID: 26547965] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/05/2023] Open
Abstract
The results of an experimental study of organophosphorus insecticides, including pirimiphosmethyl, diazinon and chlorpyrifos caused a decline of the contraction properties in m. tibialis anterior fiber bundles of Rana temporaria, as well as sarcoplasmic reticulum Ca2+, Mg(2+)-ATPase enzymatic activity reduction are outlined in this paper. Concentration-dependent strengths response diminishing in isolated skeletal muscle fiber bundles as a result of non-cholinergic influence of organophosphorus insecticides were found. A decrease of Ca2+, Mg(2+)-ATPase enzymatic activity in sarcoplasmic reticulum was observed after administration of each insecticide. The most significant inhibition of this enzyme was observed when using chlorpyrifos.
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44
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Shemarova IV, Korotkov SM, Nesterov VP. [MECHANISMS OF THE EFFECT OF Li+ ON MYOCARDIUM OF VERTEBRATES]. Zh Evol Biokhim Fiziol 2015; 51:181-186. [PMID: 26281220] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The effect of Li+ on the frog Rana temporaria myocardium and its influence on the ion transport in the rat heart mitochondria (RHM) were studied. Li+ added to the normal Ringer solution (Li(+)-R) was found to attenuate myocardial tension, decrease the maximal rate of tension development and its half-relaxation time. Comparison of the cardiac muscle contraction parameters in the Li(+)-R with the effect of the voltage-gated Ca(2+)-channels (Cav1.2), verapamil and CdCl2, showed that the negative inotropic effect of the Na+ replacement by Li+ in the limited intermembrane ("fuzzy") space is underlain by the blocking of Ca2+ influx into the myoplasm via the reverse Ca2+/Na(+)-exchanger in the plasma membrane (PM). This, in turn, prevents Ca(2+)-induced massive Ca2+ release into the myoplasm via the RYR2-channels in the sarcoplasmic reticulum (SR) leading in aggregate to suppression of Ca(2+)-dependent myocardial contractions. In the experimental studies of the Li+ effect on the RHM it was established that Li+ just slightly increases the passive permeability of the inner mitochondrial membrane (IMM) for K+ and H+ and decreases the intensity of ion pumping out of the energized mitochondrial matrix to the external medium. This may also indicate the lack of relationship between the mitochondrial oxidative processes and the reduction in the myocardial contractile activity under the Na+ replacement by Li+.
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45
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Kong DY, Hao LR, Zhang L, Li QG, Zhou JH, Shi SZ, Zhu F, Geng YQ, Chen XM. Comparison of two fluid solutions for resuscitation in a rabbit model of crush syndrome. Clin Exp Nephrol 2015; 19:1015-23. [PMID: 25910455 DOI: 10.1007/s10157-015-1114-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2014] [Accepted: 04/07/2015] [Indexed: 12/31/2022]
Abstract
BACKGROUND Crush syndrome is a common injury, the main characteristics of which include acute kidney injury. However, there is still lack of reliable animal model of crush syndrome, and it also remains controversial as to which type of fluid should be chosen as a more appropriate treatment option for prevention and treatment of acute kidney injury. METHODS The rabbits were crushed at the lower limbs for 6 h with 36 times the body weight, which means the pressure of each leg was also 36 times the body weight. Fluid resuscitation was performed from 1 h prior to the end of the crush treatment until 24 h after the reperfusion. Tissue, blood and urine samples were collected at predetermined time points before and after reperfusion. Twelve rabbits in each group were taken for survival observation for 72 h. RESULTS The model group showed elevated serum creatine kinase, aspartate aminotransferase, alanine aminotransferase, and K(+) level, reduced serum Ca(2+) level and Na(+) level, and increased serum creatinine and blood urea nitrogen levels, neutrophil gelatinase-associated lipocalin, and kidney injury molecule-1 (p < 0.05). The 0.9 % normal saline (SAL) group and SAL plus 6 % hydroxyethyl starch 130/0.4 SAL/HES group showed reduced serum creatinine and blood urea nitrogen levels (p < 0.05). The SAL/HES group also showed reduced serum IL-6 and IL-10 levels (p < 0.05). The 72 h survival rate of the SAL/HES group was higher than that of the model group (p < 0.05). CONCLUSION The rabbit model of crush syndrome showed clinical features consistent with those of crush syndrome. There was no significant difference in the ability of preventing AKI after a crush injury between the two fluid solutions, while SAL/HES can improve the survival rate.
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Affiliation(s)
- De-yang Kong
- Department of Nephrology, Chinese PLA General Hospital, Chinese PLA Institute of Nephrology, State Key Laboratory of Kidney Diseases, National Clinical Research Center of Kidney Diseases, Beijing, China
- Department of Nephrology, 1st Affiliated Hospital of Harbin Medical University, Harbin, China
| | - Li-rong Hao
- Department of Nephrology, 1st Affiliated Hospital of Harbin Medical University, Harbin, China
| | - Li Zhang
- Department of Nephrology, Chinese PLA General Hospital, Chinese PLA Institute of Nephrology, State Key Laboratory of Kidney Diseases, National Clinical Research Center of Kidney Diseases, Beijing, China.
| | - Qing-gang Li
- Department of Nephrology, Chinese PLA General Hospital, Chinese PLA Institute of Nephrology, State Key Laboratory of Kidney Diseases, National Clinical Research Center of Kidney Diseases, Beijing, China
| | - Jian-hui Zhou
- Department of Nephrology, Chinese PLA General Hospital, Chinese PLA Institute of Nephrology, State Key Laboratory of Kidney Diseases, National Clinical Research Center of Kidney Diseases, Beijing, China
| | - Suo-zhu Shi
- Department of Nephrology, Chinese PLA General Hospital, Chinese PLA Institute of Nephrology, State Key Laboratory of Kidney Diseases, National Clinical Research Center of Kidney Diseases, Beijing, China
| | - Fei Zhu
- Department of Nephrology, Chinese PLA General Hospital, Chinese PLA Institute of Nephrology, State Key Laboratory of Kidney Diseases, National Clinical Research Center of Kidney Diseases, Beijing, China
| | - Yan-qiu Geng
- Department of Nephrology, Chinese PLA General Hospital, Chinese PLA Institute of Nephrology, State Key Laboratory of Kidney Diseases, National Clinical Research Center of Kidney Diseases, Beijing, China
| | - Xiang-mei Chen
- Department of Nephrology, Chinese PLA General Hospital, Chinese PLA Institute of Nephrology, State Key Laboratory of Kidney Diseases, National Clinical Research Center of Kidney Diseases, Beijing, China.
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Woolcott OO, Islam MS. On the paper by E. R. Muslikhov, I. F. Sukhanova, and P. V. Avdonin entitled “arachidonic acid activates release of calcium ions from reticulum via ryanodine receptor channels in C2C12 skeletal myotubes” published in Biochemistry (Moscow), Vol. 79, No. 5, pp. 435-439 (2014). Biochemistry (Mosc) 2014; 79:845-6. [PMID: 25522455 DOI: 10.1134/s0006297914080136] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
A recent study published by Muslikhov et al. (Biochemistry (Moscow), 79, 435439 (2014)) showed that arachi donic acid increases cytosolic Ca2+ concentrations in C2C12 skeletal myotubes mainly via activation of the ryanodine (RY) receptor 1. These results are consistent with the data from another study demonstrating that arachidonic acid targets RY receptor 2 in clonal and primary pancreatic βcells (Woolcott et al., 2006). A novel and intriguing finding by Muslikhov’s group is that arachidonic acid also appears to activate the twopore ion channel (TPC), suggesting that arachidonic acid could be a mediator in the interaction between TPCs and RY receptors.
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47
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Bovo E, de Tombe PP, Zima AV. The role of dyadic organization in regulation of sarcoplasmic reticulum Ca(2+) handling during rest in rabbit ventricular myocytes. Biophys J 2014; 106:1902-9. [PMID: 24806922 DOI: 10.1016/j.bpj.2014.03.032] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2013] [Revised: 02/24/2014] [Accepted: 03/25/2014] [Indexed: 01/01/2023] Open
Abstract
The dyadic organization of ventricular myocytes ensures synchronized activation of sarcoplasmic reticulum (SR) Ca(2+) release during systole. However, it remains obscure how the dyadic organization affects SR Ca(2+) handling during diastole. By measuring intraluminal SR Ca(2+) ([Ca(2+)]SR) decline during rest in rabbit ventricular myocytes, we found that ∼76% of leaked SR Ca(2+) is extruded from the cytosol and only ∼24% is pumped back into the SR. Thus, the majority of Ca(2+) that leaks from the SR is removed from the cytosol before it can be sequestered back into the SR by the SR Ca(2+)-ATPase (SERCA). Detubulation decreased [Ca(2+)]SR decline during rest, thus making the leaked SR Ca(2+) more accessible for SERCA. These results suggest that Ca(2+) extrusion systems are localized in T-tubules. Inhibition of Na(+)-Ca(2+) exchanger (NCX) slowed [Ca(2+)]SR decline during rest by threefold, however did not prevent it. Depolarization of mitochondrial membrane potential during NCX inhibition completely prevented the rest-dependent [Ca(2+)]SR decline. Despite a significant SR Ca(2+) leak, Ca(2+) sparks were very rare events in control conditions. NCX inhibition or detubulation increased Ca(2+) spark activity independent of SR Ca(2+) load. Overall, these results indicate that during rest NCX effectively competes with SERCA for cytosolic Ca(2+) that leaks from the SR. This can be explained if the majority of SR Ca(2+) leak occurs through ryanodine receptors in the junctional SR that are located closely to NCX in the dyadic cleft. Such control of the dyadic [Ca(2+)] by NCX play a critical role in suppressing Ca(2+) sparks during rest.
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Affiliation(s)
- Elisa Bovo
- Department of Cell and Molecular Physiology, Loyola University Chicago, Stritch School of Medicine, Maywood, Illinois
| | - Pieter P de Tombe
- Department of Cell and Molecular Physiology, Loyola University Chicago, Stritch School of Medicine, Maywood, Illinois
| | - Aleksey V Zima
- Department of Cell and Molecular Physiology, Loyola University Chicago, Stritch School of Medicine, Maywood, Illinois.
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48
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Hanna AD, Lam A, Tham S, Dulhunty AF, Beard NA. Adverse effects of doxorubicin and its metabolic product on cardiac RyR2 and SERCA2A. Mol Pharmacol 2014; 86:438-49. [PMID: 25106424 PMCID: PMC4164980 DOI: 10.1124/mol.114.093849] [Citation(s) in RCA: 95] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2014] [Accepted: 08/08/2014] [Indexed: 11/22/2022] Open
Abstract
The use of anthracycline chemotherapeutic drugs is restricted owing to potentially fatal cardiotoxic side effects. It has been hypothesized that anthracycline metabolites have a primary role in this cardiac dysfunction; however, information on the molecular interactions of these compounds in the heart is scarce. Here we provide novel evidence that doxorubicin and its metabolite, doxorubicinol, bind to the cardiac ryanodine receptor (RyR2) and to the sarco/endoplasmic reticulum Ca(2+) ATPase (SERCA2A) and deleteriously alter their activity. Both drugs (0.01 μM-2.5 μM) activated single RyR2 channels, and this was reversed by drug washout. Both drugs caused a secondary inhibition of RyR2 activity that was not reversed by drug washout. Preincubation with the reducing agent dithiothreitol (DTT, 1 mM) prevented drug-induced inhibition of channel activity. Doxorubicin and doxorubicinol reduced the abundance of thiol groups on RyR2, further indicating that oxidation reactions may be involved in the actions of the compounds. Ca(2+) uptake into sarcoplasmic reticulum vesicles by SERCA2A was inhibited by doxorubicinol, but not doxorubicin. Unexpectedly, in the presence of DTT, doxorubicinol enhanced the rate of Ca(2+) uptake by SERCA2A. Together the evidence provided here shows that doxorubicin and doxorubicinol interact with RyR2 and SERCA2A in similar ways, but that the metabolite acts with greater efficacy than the parent compound. Both compounds modify RyR2 and SERCA2A activity by binding to the proteins and also act via thiol oxidation to disrupt SR Ca(2+) handling. These actions would have severe consequences on cardiomyocyte function and contribute to clinical symptoms of acute anthracycline cardiotoxicity.
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Affiliation(s)
- Amy D Hanna
- John Curtin School of Medical Research, Australian National University, Canberra, ACT, Australia
| | - Alex Lam
- John Curtin School of Medical Research, Australian National University, Canberra, ACT, Australia
| | - Steffi Tham
- John Curtin School of Medical Research, Australian National University, Canberra, ACT, Australia
| | - Angela F Dulhunty
- John Curtin School of Medical Research, Australian National University, Canberra, ACT, Australia
| | - Nicole A Beard
- John Curtin School of Medical Research, Australian National University, Canberra, ACT, Australia
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Coca R, Soler F, Cortés-Castell E, Gil-Guillén V, Fernández-Belda F. Inhibition mechanism of the intracellular transporter Ca2+-pump from sarco-endoplasmic reticulum by the antitumor agent dimethyl-celecoxib. PLoS One 2014; 9:e102083. [PMID: 25003576 PMCID: PMC4086972 DOI: 10.1371/journal.pone.0102083] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2014] [Accepted: 06/13/2014] [Indexed: 11/23/2022] Open
Abstract
Dimethyl-celecoxib is a celecoxib analog that lacks the capacity as cyclo-oxygenase-2 inhibitor and therefore the life-threatening effects but retains the antineoplastic properties. The action mechanism at the molecular level is unclear. Our in vitro assays using a sarcoplasmic reticulum preparation from rabbit skeletal muscle demonstrate that dimethyl-celecoxib inhibits Ca2+-ATPase activity and ATP-dependent Ca2+ transport in a concentration-dependent manner. Celecoxib was a more potent inhibitor of Ca2+-ATPase activity than dimethyl-celecoxib, as deduced from the half-maximum effect but dimethyl-celecoxib exhibited higher inhibition potency when Ca2+ transport was evaluated. Since Ca2+ transport was more sensitive to inhibition than Ca2+-ATPase activity the drugs under study caused Ca2+/Pi uncoupling. Dimethyl-celecoxib provoked greater uncoupling and the effect was dependent on drug concentration but independent of Ca2+-pump functioning. Dimethyl-celecoxib prevented Ca2+ binding by stabilizing the inactive Ca2+-free conformation of the pump. The effect on the kinetics of phosphoenzyme accumulation and the dependence of the phosphoenzyme level on dimethyl-celecoxib concentration were independent of whether or not the Ca2+–pump was exposed to the drug in the presence of Ca2+ before phosphorylation. This provided evidence of non-preferential interaction with the Ca2+-free conformation. Likewise, the decreased phosphoenzyme level in the presence of dimethyl-celecoxib that was partially relieved by increasing Ca2+ was consistent with the mentioned effect on Ca2+ binding. The kinetics of phosphoenzyme decomposition under turnover conditions was not altered by dimethyl-celecoxib. The dual effect of the drug involves Ca2+-pump inhibition and membrane permeabilization activity. The reported data can explain the cytotoxic and anti-proliferative effects that have been attributed to the celecoxib analog. Ligand docking simulation predicts interaction of celecoxib and dimethyl-celecoxib with the intracellular Ca2+ transporter at the inhibition site of hydroquinones.
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Affiliation(s)
- Ramón Coca
- Departamento de Medicina Clínica, Universidad Miguel Hernández en Campus de San Juan, Alicante, Spain
| | - Fernando Soler
- Departamento de Bioquímica y Biología Molecular A, Universidad de Murcia en Campus de Espinardo, Murcia, Spain
| | - Ernesto Cortés-Castell
- Departamento de Farmacología, Pediatría y Química Orgánica, Universidad Miguel Hernández en Campus de San Juan, Alicante, Spain
| | - Vicente Gil-Guillén
- Departamento de Medicina Clínica, Universidad Miguel Hernández en Campus de San Juan, Alicante, Spain
| | - Francisco Fernández-Belda
- Departamento de Bioquímica y Biología Molecular A, Universidad de Murcia en Campus de Espinardo, Murcia, Spain
- * E-mail:
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Zaniboni M, Cacciani F, Lux RL. Beat-to-beat cycle length variability of spontaneously beating guinea pig sinoatrial cells: relative contributions of the membrane and calcium clocks. PLoS One 2014; 9:e100242. [PMID: 24940609 PMCID: PMC4062511 DOI: 10.1371/journal.pone.0100242] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2014] [Accepted: 05/23/2014] [Indexed: 11/18/2022] Open
Abstract
The heartbeat arises rhythmically in the sino-atrial node (SAN) and then spreads regularly throughout the heart. The molecular mechanism underlying SAN rhythm has been attributed by recent studies to the interplay between two clocks, one involving the hyperpolarization activated cation current If (the membrane clock), and the second attributable to activation of the electrogenic NaCa exchanger by spontaneous sarcoplasmic releases of calcium (the calcium clock). Both mechanisms contain, in principle, sources of beat-to-beat cycle length variability, which can determine the intrinsic variability of SAN firing and, in turn, contribute to the heart rate variability. In this work we have recorded long sequences of action potentials from patch clamped guinea pig SAN cells (SANCs) perfused, in turn, with normal Tyrode solution, with the If inhibitor ivabradine (3 µM), then back to normal Tyrode, and again with the ryanodine channels inhibitor ryanodine (3 µM). We have found that, together with the expected increase in beating cycle length (+25%), the application of ivabradine brought about a significant and dramatic increase in beat-to-beat cycle length variability (+50%). Despite the similar effect on firing rate, ryanodine did not modify significantly beat-to-beat cycle length variability. Acetylcholine was also applied and led to a 131% increase of beating cycle length, with only a 70% increase in beat-to-beat cycle length variability. We conclude that the main source of inter-beat variability of SANCs firing rate is related to the mechanism of the calcium clock, whereas the membrane clock seems to act in stabilizing rate. Accordingly, when the membrane clock is silenced by application of ivabradine, stochastic variations of the calcium clock are free to make SANCs beating rhythm more variable.
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Affiliation(s)
- Massimiliano Zaniboni
- Department of Life Sciences, University of Parma, Parma, Italy
- Center of Excellence for Toxicological Research, University of Parma, Parma, Italy
- * E-mail:
| | | | - Robert L. Lux
- Cardiovascular Research and Training Institute, University of Utah, Salt Lake City, Utah, United States of America
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