1
|
Nutini A. Amyloid oligomers and their membrane toxicity - A perspective study. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2024; 187:9-20. [PMID: 38211711 DOI: 10.1016/j.pbiomolbio.2024.01.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Revised: 12/21/2023] [Accepted: 01/07/2024] [Indexed: 01/13/2024]
Abstract
Amyloidosis is a condition involving a disparate group of pathologies characterized by the extracellular deposition of insoluble fibrils composed of broken-down proteins. These proteins can accumulate locally, causing peculiar symptoms, or in a widespread way, involving many organs and. causing severe systemic failure. The damage that is created is related not only to the accumulation of. amyloid fibrils but above all to the precursor oligomers of the fibrils that manage to enter the cell in a very particular way. This article analyzes the current state of research related to the entry of these oligomers into the cell membrane and the theories related to their toxicity. The paper proposed here not only aims to review the contents in the literature but also proposes a new vision of amyloid toxicity. that could occur in a multiphase process catalyzed by the cell membrane itself. In this process, the denaturation of the lipid bilayer is followed by the stabilization of a pore through energetically favorable self-assembly processes which are achieved through particular oligomeric structures.
Collapse
Affiliation(s)
- Alessandro Nutini
- Biology and Biomechanics Dept - Centro Studi Attività Motorie, Italy.
| |
Collapse
|
2
|
Kruglov AG, Romshin AM, Nikiforova AB, Plotnikova A, Vlasov II. Warm Cells, Hot Mitochondria: Achievements and Problems of Ultralocal Thermometry. Int J Mol Sci 2023; 24:16955. [PMID: 38069275 PMCID: PMC10707128 DOI: 10.3390/ijms242316955] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2023] [Revised: 11/27/2023] [Accepted: 11/28/2023] [Indexed: 12/18/2023] Open
Abstract
Temperature is a crucial regulator of the rate and direction of biochemical reactions and cell processes. The recent data indicating the presence of local thermal gradients associated with the sites of high-rate thermogenesis, on the one hand, demonstrate the possibility for the existence of "thermal signaling" in a cell and, on the other, are criticized on the basis of thermodynamic calculations and models. Here, we review the main thermometric techniques and sensors developed for the determination of temperature inside living cells and diverse intracellular compartments. A comparative analysis is conducted of the results obtained using these methods for the cytosol, nucleus, endo-/sarcoplasmic reticulum, and mitochondria, as well as their biological consistency. Special attention is given to the limitations, possible sources of errors and ambiguities of the sensor's responses. The issue of biological temperature limits in cells and organelles is considered. It is concluded that the elaboration of experimental protocols for ultralocal temperature measurements that take into account both the characteristics of biological systems, as well as the properties and limitations of each type of sensor is of critical importance for the generation of reliable results and further progress in this field.
Collapse
Affiliation(s)
- Alexey G. Kruglov
- Institute of Theoretical and Experimental Biophysics of the Russian Academy of Sciences, 142290 Pushchino, Russia;
| | - Alexey M. Romshin
- Prokhorov General Physics Institute of the Russian Academy of Sciences, 119991 Moscow, Russia;
| | - Anna B. Nikiforova
- Institute of Theoretical and Experimental Biophysics of the Russian Academy of Sciences, 142290 Pushchino, Russia;
| | - Arina Plotnikova
- Institute for Physics and Engineering in Biomedicine, National Research Nuclear University MEPhI (Moscow Engineering Physics Institute MEPhI), 115409 Moscow, Russia;
| | - Igor I. Vlasov
- Prokhorov General Physics Institute of the Russian Academy of Sciences, 119991 Moscow, Russia;
| |
Collapse
|
3
|
Henriquez E, Hernandez EA, Mundla SR, Wankhade DH, Saad M, Ketha SS, Penke Y, Martinez GC, Ahmed FS, Hussain MS. Catecholaminergic Polymorphic Ventricular Tachycardia and Gene Therapy: A Comprehensive Review of the Literature. Cureus 2023; 15:e47974. [PMID: 38034271 PMCID: PMC10686237 DOI: 10.7759/cureus.47974] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/30/2023] [Indexed: 12/02/2023] Open
Abstract
Catecholaminergic polymorphic ventricular tachycardia (CPVT) is an inherited channelopathy. In this review, we summarize the epidemiology, pathophysiology, clinical characteristics, diagnostics, genetic mutations, standard treatment, and the emergence of potential gene therapy. This inherited cardiac arrhythmia presents in a bimodal distribution with no association between sex or ethnicity. Six different CPVT genes have been identified, however, most of the cases are related to a heterozygous, gain-of-function mutation on the ryanodine receptor-2 gene (RyR2) and calsequestrin-2 gene (CASQ2) that causes delayed after-depolarization. The diagnosis is clinically based, seen in patients presenting with syncope after exercise or stress-related emotions, as well as cardiac arrest with full recovery or even sudden cardiac death. Standard treatment relies on beta-blockers, with add-on therapy, flecainide, and cardiac sympathetic denervation as second-line treatments. An implantable cardioverter-defibrillator is indicated for patients who have suffered a cardiac arrest. Potential gene therapy has emerged in the last 20 years and accelerated because of associated viral vector application in increasing the efficiency of prolonged cardiac gene expression. Nevertheless, human trials for gene therapy for CPVT have been limited as the population is rare, and an excessive amount of funding is required.
Collapse
Affiliation(s)
- Elvis Henriquez
- Miscellaneous, Facultad de Medicina, Universidad de Ciencias Medicas, Las Tunas, CUB
| | - Edwin A Hernandez
- Miscellaneous, Faculty of Medicine, Universidad de El Salvador, San Salvador, SLV
| | - Sravya R Mundla
- Internal Medicine, Apollo Institute of Medical Sciences and Research, Hyderabad, IND
| | | | - Muhammad Saad
- Internal Medicine, Fatima Memorial College (FMH) of Medicine and Dentistry, Lahore, PAK
| | - Sagar S Ketha
- Internal Medicine, Government Medical College, Srikakulam, IND
| | - Yasaswini Penke
- Internal Medicine, Government Medical College, Srikakulam, IND
| | - Gabriela C Martinez
- Internal Medicine, Faculty of Medicine, Universidad Nacional Autonoma de Honduras, San Pedro Sula, HND
| | - Faiza S Ahmed
- Internal Medicine, Advocate Lutheran General Hospital, Park Ridge, USA
| | | |
Collapse
|
4
|
Fazio A, Evangelisti C, Cappellini A, Mongiorgi S, Koufi FD, Neri I, Marvi MV, Russo M, Ghigo A, Manzoli L, Fiume R, Ratti S. Emerging Roles of Phospholipase C Beta Isozymes as Potential Biomarkers in Cardiac Disorders. Int J Mol Sci 2023; 24:13096. [PMID: 37685903 PMCID: PMC10487445 DOI: 10.3390/ijms241713096] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2023] [Revised: 08/19/2023] [Accepted: 08/21/2023] [Indexed: 09/10/2023] Open
Abstract
Phospholipase C (PLC) enzymes represent crucial participants in the plasma membrane of mammalian cells, including the cardiac sarcolemmal (SL) membrane of cardiomyocytes. They are responsible for the hydrolysis of phosphatidylinositol 4,5-bisphosphate (PtdIns(4,5)P2) into 1,2-diacylglycerol (DAG) and inositol (1,4,5) trisphosphate (Ins(1,4,5)P3), both essential lipid mediators. These second messengers regulate the intracellular calcium (Ca2+) concentration, which activates signal transduction cascades involved in the regulation of cardiomyocyte activity. Of note, emerging evidence suggests that changes in cardiomyocytes' phospholipid profiles are associated with an increased occurrence of cardiovascular diseases, but the underlying mechanisms are still poorly understood. This review aims to provide a comprehensive overview of the significant impact of PLC on the cardiovascular system, encompassing both physiological and pathological conditions. Specifically, it focuses on the relevance of PLCβ isoforms as potential cardiac biomarkers, due to their implications for pathological disorders, such as cardiac hypertrophy, diabetic cardiomyopathy, and myocardial ischemia/reperfusion injury. Gaining a deeper understanding of the mechanisms underlying PLCβ activation and regulation is crucial for unraveling the complex signaling networks involved in healthy and diseased myocardium. Ultimately, this knowledge holds significant promise for advancing the development of potential therapeutic strategies that can effectively target and address cardiac disorders by focusing on the PLCβ subfamily.
Collapse
Affiliation(s)
- Antonietta Fazio
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Via Irnerio 48, 40126 Bologna, Italy; (A.F.); (C.E.); (A.C.); (S.M.); (F.-D.K.); (I.N.); (M.V.M.); (L.M.)
| | - Camilla Evangelisti
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Via Irnerio 48, 40126 Bologna, Italy; (A.F.); (C.E.); (A.C.); (S.M.); (F.-D.K.); (I.N.); (M.V.M.); (L.M.)
| | - Alessandra Cappellini
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Via Irnerio 48, 40126 Bologna, Italy; (A.F.); (C.E.); (A.C.); (S.M.); (F.-D.K.); (I.N.); (M.V.M.); (L.M.)
| | - Sara Mongiorgi
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Via Irnerio 48, 40126 Bologna, Italy; (A.F.); (C.E.); (A.C.); (S.M.); (F.-D.K.); (I.N.); (M.V.M.); (L.M.)
| | - Foteini-Dionysia Koufi
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Via Irnerio 48, 40126 Bologna, Italy; (A.F.); (C.E.); (A.C.); (S.M.); (F.-D.K.); (I.N.); (M.V.M.); (L.M.)
| | - Irene Neri
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Via Irnerio 48, 40126 Bologna, Italy; (A.F.); (C.E.); (A.C.); (S.M.); (F.-D.K.); (I.N.); (M.V.M.); (L.M.)
| | - Maria Vittoria Marvi
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Via Irnerio 48, 40126 Bologna, Italy; (A.F.); (C.E.); (A.C.); (S.M.); (F.-D.K.); (I.N.); (M.V.M.); (L.M.)
| | - Michele Russo
- Department of Molecular Biotechnology and Health Sciences, Molecular Biotechnology Center “Guido Tarone”, University of Torino, 10126 Torino, Italy; (M.R.); (A.G.)
| | - Alessandra Ghigo
- Department of Molecular Biotechnology and Health Sciences, Molecular Biotechnology Center “Guido Tarone”, University of Torino, 10126 Torino, Italy; (M.R.); (A.G.)
| | - Lucia Manzoli
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Via Irnerio 48, 40126 Bologna, Italy; (A.F.); (C.E.); (A.C.); (S.M.); (F.-D.K.); (I.N.); (M.V.M.); (L.M.)
| | - Roberta Fiume
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Via Irnerio 48, 40126 Bologna, Italy; (A.F.); (C.E.); (A.C.); (S.M.); (F.-D.K.); (I.N.); (M.V.M.); (L.M.)
| | - Stefano Ratti
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Via Irnerio 48, 40126 Bologna, Italy; (A.F.); (C.E.); (A.C.); (S.M.); (F.-D.K.); (I.N.); (M.V.M.); (L.M.)
| |
Collapse
|
5
|
Terrar DA. Timing mechanisms to control heart rhythm and initiate arrhythmias: roles for intracellular organelles, signalling pathways and subsarcolemmal Ca 2. Philos Trans R Soc Lond B Biol Sci 2023; 378:20220170. [PMID: 37122228 PMCID: PMC10150226 DOI: 10.1098/rstb.2022.0170] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/02/2023] Open
Abstract
Rhythms of electrical activity in all regions of the heart can be influenced by a variety of intracellular membrane bound organelles. This is true both for normal pacemaker activity and for abnormal rhythms including those caused by early and delayed afterdepolarizations under pathological conditions. The influence of the sarcoplasmic reticulum (SR) on cardiac electrical activity is widely recognized, but other intracellular organelles including lysosomes and mitochondria also contribute. Intracellular organelles can provide a timing mechanism (such as an SR clock driven by cyclic uptake and release of Ca2+, with an important influence of intraluminal Ca2+), and/or can act as a Ca2+ store involved in signalling mechanisms. Ca2+ plays many diverse roles including carrying electric current, driving electrogenic sodium-calcium exchange (NCX) particularly when Ca2+ is extruded across the surface membrane causing depolarization, and activation of enzymes which target organelles and surface membrane proteins. Heart function is also influenced by Ca2+ mobilizing agents (cADP-ribose, nicotinic acid adenine dinucleotide phosphate and inositol trisphosphate) acting on intracellular organelles. Lysosomal Ca2+ release exerts its effects via calcium/calmodulin-dependent protein kinase II to promote SR Ca2+ uptake, and contributes to arrhythmias resulting from excessive beta-adrenoceptor stimulation. A separate arrhythmogenic mechanism involves lysosomes, mitochondria and SR. Interacting intracellular organelles, therefore, have profound effects on heart rhythms and NCX plays a central role. This article is part of the theme issue 'The heartbeat: its molecular basis and physiological mechanisms'.
Collapse
Affiliation(s)
- Derek A Terrar
- Department of Pharmacology, University of Oxford, Oxford OX1 3QT, UK
| |
Collapse
|
6
|
Banerjee S, Hong J, Umar S. Comparative analysis of right ventricular metabolic reprogramming in pre-clinical rat models of severe pulmonary hypertension-induced right ventricular failure. Front Cardiovasc Med 2022; 9:935423. [PMID: 36158812 PMCID: PMC9500217 DOI: 10.3389/fcvm.2022.935423] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2022] [Accepted: 08/25/2022] [Indexed: 12/14/2022] Open
Abstract
Background Pulmonary hypertension (PH) leads to right ventricular (RV) hypertrophy and failure (RVF). The precise mechanisms of the metabolic basis of maladaptive PH-induced RVF (PH-RVF) are yet to be fully elucidated. Here we performed a comparative analysis of RV-metabolic reprogramming in MCT and Su/Hx rat models of severe PH-RVF using targeted metabolomics and multi-omics. Methods Male Sprague Dawley rats (250–300 gm; n = 15) were used. Rats received subcutaneous monocrotaline (60 mg/kg; MCT; n = 5) and followed for ~30-days or Sugen (20 mg/kg; Su/Hx; n = 5) followed by hypoxia (10% O2; 3-weeks) and normoxia (2-weeks). Controls received saline (Control; n = 5). Serial echocardiography was performed to assess cardiopulmonary hemodynamics. Terminal RV-catheterization was performed to assess PH. Targeted metabolomics was performed on RV tissue using UPLC-MS. RV multi-omics analysis was performed integrating metabolomic and transcriptomic datasets using Joint Pathway Analysis (JPA). Results MCT and Su/Hx rats developed severe PH, RV-hypertrophy and decompensated RVF. Targeted metabolomics of RV of MCT and Su/Hx rats detected 126 and 125 metabolites, respectively. There were 28 and 24 metabolites significantly altered in RV of MCT and Su/Hx rats, respectively, including 11 common metabolites. Common significantly upregulated metabolites included aspartate and GSH, whereas downregulated metabolites included phosphate, α-ketoglutarate, inositol, glutamine, 5-Oxoproline, hexose phosphate, creatine, pantothenic acid and acetylcarnitine. JPA highlighted common genes and metabolites from key pathways such as glycolysis, fatty acid metabolism, oxidative phosphorylation, TCA cycle, etc. Conclusions Comparative analysis of metabolic reprogramming of RV from MCT and Su/Hx rats reveals common and distinct metabolic signatures which may serve as RV-specific novel therapeutic targets for PH-RVF.
Collapse
Affiliation(s)
- Somanshu Banerjee
- Division of Molecular Medicine, Department of Anesthesiology and Perioperative Medicine, Los Angeles, CA, United States
| | - Jason Hong
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, David Geffen School of Medicine, University of California Los Angeles (UCLA), Los Angeles, CA, United States
| | - Soban Umar
- Division of Molecular Medicine, Department of Anesthesiology and Perioperative Medicine, Los Angeles, CA, United States
| |
Collapse
|
7
|
Xia L, Wang X, Yao W, Wang M, Zhu J. Lipopolysaccharide increases exosomes secretion from endothelial progenitor cells by toll-like receptor 4 dependent mechanism. Biol Cell 2022; 114:127-137. [PMID: 35235701 DOI: 10.1111/boc.202100086] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Revised: 01/18/2022] [Accepted: 02/17/2022] [Indexed: 11/27/2022]
Abstract
Endothelial progenitor cells (EPCs) can exert angiogenic effects by a paracrine mechanism, where exosomes work as an important mediator. Recent studies reported functional expression of toll-like receptor (TLR) 4 on human EPCs and dose-dependent effects of lipopolysaccharide (LPS) on EPC angiogenic properties. To study on the effects of TLR4/LPS signaling on EPC-derived exosomes (Exo) and involved mechanisms, we investigated the effect of LPS on exosomes secretion from human EPC and tested Exo functions by senescence-associated β-galactosidase activity assay and reactive oxygen species (ROS) related H2 DCF-DA assay. To clarify the mechanism, we examined the changes in intracellular calcium levels and multivesicular bodies (MVBs) development in EPC. We employed the inhibitors of the plasma membrane Ca 2+ -ATPase (PMCA), endoplasmic reticulum Ca 2+ -ATPase (ERCA), PLC-IP3 pathway and store-operated calcium entry to assess the effects of LPS on calcium signalings which critical for exosome secretion. LPS induced the release of Exo in a TLR4-dependent manner in vitro, which effect can be partly abrogated by the membrane-permeable IP 3 R antagonist, 2-aminoethyl diphenylborinate (2-APB), but not PLC inhibitor, U-73122. The LPS can significantly delay the fallback of [Ca 2+ ]i after isolating the cellular PMCA activity, and disturb PMCA 1/4 expression. The distribution of elevated intracellular calcium seemed coincident with the development of MVBs. Furthermore, the LPS-induced Exo maintained valid anti-oxidation/senescence properties. The PMCA and ER Ca 2+ release mechanism may contribute to the pro-exosomal effects of LPS on EPC, which is valuable for potential pro-regenerative application in future. This article is protected by copyright. All rights reserved.
Collapse
Affiliation(s)
- Liang Xia
- Department of Clinical Medicine, School of Medicine, Zhejiang University City College, Hangzhou, Zhejiang, China
| | - Xiaotian Wang
- Department of Clinical Medicine, School of Medicine, Zhejiang University City College, Hangzhou, Zhejiang, China
| | - Weidong Yao
- Department of Clinical Medicine, School of Medicine, Zhejiang University City College, Hangzhou, Zhejiang, China
| | - Meihui Wang
- Biomedical Research (Therapy) Center, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China
| | - Junhui Zhu
- Department of Cardiology, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China
| |
Collapse
|
8
|
Aguayo-Ortiz R, Creech J, Jiménez-Vázquez EN, Guerrero-Serna G, Wang N, da Rocha AM, Herron TJ, Espinoza-Fonseca LM. A multiscale approach for bridging the gap between potency, efficacy, and safety of small molecules directed at membrane proteins. Sci Rep 2021; 11:16580. [PMID: 34400719 PMCID: PMC8368179 DOI: 10.1038/s41598-021-96217-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Accepted: 08/06/2021] [Indexed: 01/17/2023] Open
Abstract
Membrane proteins constitute a substantial fraction of the human proteome, thus representing a vast source of therapeutic drug targets. Indeed, newly devised technologies now allow targeting "undruggable" regions of membrane proteins to modulate protein function in the cell. Despite the advances in technology, the rapid translation of basic science discoveries into potential drug candidates targeting transmembrane protein domains remains challenging. We address this issue by harmonizing single molecule-based and ensemble-based atomistic simulations of ligand-membrane interactions with patient-derived induced pluripotent stem cell (iPSC)-based experiments to gain insights into drug delivery, cellular efficacy, and safety of molecules directed at membrane proteins. In this study, we interrogated the pharmacological activation of the cardiac Ca2+ pump (Sarcoplasmic reticulum Ca2+-ATPase, SERCA2a) in human iPSC-derived cardiac cells as a proof-of-concept model. The combined computational-experimental approach serves as a platform to explain the differences in the cell-based activity of candidates with similar functional profiles, thus streamlining the identification of drug-like candidates that directly target SERCA2a activation in human cardiac cells. Systematic cell-based studies further showed that a direct SERCA2a activator does not induce cardiotoxic pro-arrhythmogenic events in human cardiac cells, demonstrating that pharmacological stimulation of SERCA2a activity is a safe therapeutic approach targeting the heart. Overall, this novel multiscale platform encompasses organ-specific drug potency, efficacy, and safety, and opens new avenues to accelerate the bench-to-patient research aimed at designing effective therapies directed at membrane protein domains.
Collapse
Affiliation(s)
- Rodrigo Aguayo-Ortiz
- Division of Cardiovascular Medicine, Department of Internal Medicine, Center for Arrhythmia Research, University of Michigan, Ann Arbor, MI, 48109, USA
- Departamento de Farmacia, Facultad de Química, Universidad Nacional Autónoma de México, 04510, Mexico, Mexico
| | - Jeffery Creech
- Division of Cardiovascular Medicine, Department of Internal Medicine, Center for Arrhythmia Research, University of Michigan, Ann Arbor, MI, 48109, USA
- Frankel Cardiovascular Regeneration Core Laboratory, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Eric N Jiménez-Vázquez
- Division of Cardiovascular Medicine, Department of Internal Medicine, Center for Arrhythmia Research, University of Michigan, Ann Arbor, MI, 48109, USA
- Department of Pharmacology, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Guadalupe Guerrero-Serna
- Division of Cardiovascular Medicine, Department of Internal Medicine, Center for Arrhythmia Research, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Nulang Wang
- Division of Cardiovascular Medicine, Department of Internal Medicine, Center for Arrhythmia Research, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Andre Monteiro da Rocha
- Division of Cardiovascular Medicine, Department of Internal Medicine, Center for Arrhythmia Research, University of Michigan, Ann Arbor, MI, 48109, USA
- Frankel Cardiovascular Regeneration Core Laboratory, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Todd J Herron
- Division of Cardiovascular Medicine, Department of Internal Medicine, Center for Arrhythmia Research, University of Michigan, Ann Arbor, MI, 48109, USA
- Frankel Cardiovascular Regeneration Core Laboratory, University of Michigan, Ann Arbor, MI, 48109, USA
- CARTOX, Inc., 56655 Grand River Ave., PO Box 304, New Hudson, MI, 48165, USA
| | - L Michel Espinoza-Fonseca
- Division of Cardiovascular Medicine, Department of Internal Medicine, Center for Arrhythmia Research, University of Michigan, Ann Arbor, MI, 48109, USA.
| |
Collapse
|
9
|
Liu L, Liu X, Liu M, Xie D, Yan H. Proline hydroxylase domain-containing enzymes regulate calcium levels in cardiomyocytes by TRPA1 ion channel. Exp Cell Res 2021; 407:112777. [PMID: 34389294 DOI: 10.1016/j.yexcr.2021.112777] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Revised: 07/01/2021] [Accepted: 08/07/2021] [Indexed: 11/15/2022]
Abstract
The proline hydroxylase domain-containing enzymes (PHDs) acts as cellular oxygen sensors, inducing a series of responses to hypoxia, especially during the regulation of metabolism and energy homeostasis. The increase of Ca2+ in cardiomyocytes, induced by the opening of PHD signaling pathway, is the key initiation signal necessary for the PHD-mediated regulation of the energy metabolism pathway, but the underlying molecular mechanism remains incompletely understood. This study used PHD inhibitors (PHIs) and PHD2-specific RNA interference (PHD2shRNA) to inhibit PHD signals in cardiomyocytes to explore whether transient receptor potential ankyrin 1 (TRPA1) is involved in the regulation of calcium ion influx in the PHD activation pathway associated with to AMP-activated protein kinase (AMPK). The Fluo-3AM probe was used to measure changes in free intracellular calcium ion concentrations, and western blot analysis was used to detect the levels of phosphorylated (P)-AMPK, TRPA1, and P-Ca2+/calmodulin-dependent protein kinase Ⅱ (CaMKⅡ) levels. The PHI-mediated inhibition of PHD resulted in an increase in free Ca2+ fluorescence in cardiomyocytes, which activated AMPK, TRPA1, and CaMKⅡ. The TRPA1 inhibitor HC030031, the CaMKII inhibitor KN93, and a ryanodine inhibitor (Ryanodine) were all able to inhibit the PHI-induced increase in intracellular Ca2+ and AMPK activation. Both PHIs and PHD2shRNA were able to effectively activate CaMKII and TRPA1. However, an inositol 1,4,5-triphosphate receptor (IP3R) inhibitor and the protein kinase A (PKA) inhibitor H89 did not significantly inhibit the PHI-induced increase in intracellular Ca2+ and AMPK activation. These results indicated that PHD might activate the CaMKⅡ pathway through the TRPA1 ion channel, inducing the release of calcium from the sarcoplasmic reticulum through ryanodine receptor 2 (RyR2), activating AMPK to initiate the protective effects of hypoxia in cardiomyocytes.
Collapse
Affiliation(s)
- Lan Liu
- Department of Plastic and Burn Surgery, Affiliated Hospital of Southwest Medical University, National Key Clinical Construction Specialty, Wound Repair and Regeneration Laboratory, Luzhou, Sichuan Province, 646000, China
| | - Xingke Liu
- Department of Plastic and Burn Surgery, Affiliated Hospital of Southwest Medical University, National Key Clinical Construction Specialty, Wound Repair and Regeneration Laboratory, Luzhou, Sichuan Province, 646000, China
| | - Mengchang Liu
- Department of Plastic and Burn Surgery, Affiliated Hospital of Southwest Medical University, National Key Clinical Construction Specialty, Wound Repair and Regeneration Laboratory, Luzhou, Sichuan Province, 646000, China
| | - Defu Xie
- Department of Plastic and Burn Surgery, Affiliated Hospital of Southwest Medical University, National Key Clinical Construction Specialty, Wound Repair and Regeneration Laboratory, Luzhou, Sichuan Province, 646000, China
| | - Hong Yan
- Department of Plastic and Burn Surgery, Affiliated Hospital of Southwest Medical University, National Key Clinical Construction Specialty, Wound Repair and Regeneration Laboratory, Luzhou, Sichuan Province, 646000, China.
| |
Collapse
|
10
|
Gao T, Yang P, Fu D, Liu M, Deng X, Shao M, Liao J, Jiang H, Li X. The protective effect of allicin on myocardial ischemia-reperfusion by inhibition of Ca 2+ overload-induced cardiomyocyte apoptosis via the PI3K/GRK2/PLC-γ/IP3R signaling pathway. Aging (Albany NY) 2021; 13:19643-19656. [PMID: 34343971 PMCID: PMC8386544 DOI: 10.18632/aging.203375] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2021] [Accepted: 07/21/2021] [Indexed: 01/17/2023]
Abstract
Purpose: To investigate the protective effect and mechanism of allicin on myocardial ischemia-reperfusion (MI/R) injury. Methods: We investigated the mechanisms by which allicin attenuated the MI/R injury by focusing on phosphoinositide 3-kinase, G protein coupled receptor kinases 2, phospholipase Cγ and cardiomyocyte apoptosis. Sixty male mice were randomly assigned into three groups: repeated MI/R (model), sham-operated (control), and MI/R+ allicin group (allicin). Ultrasound examination was used to examine the cardiac function. Masson staining was used to evaluate the myocardial infarct area. TUNEL assay was performed to examine the anti-apoptotic effect of allicin. Differentially expressed genes (DEGs) and pathways were analyzed by mRNA microarray analysis. Immunofluorescence staining and western blot were carried out to detect the effect of allicin on the PI3K. A pan-PLC activator, m-3M3FBS, was applied to investigate whether allicin induced cardiomyocyte apoptosis was via the GRK2/PLC/IP3R signaling pathway. Results: Masson staining and the TUNEL assay revealed that allicin reduced infarct size and played an anti-apoptotic role in M/IR. Ultrasound examination revealed that allicin improved cardiac function after M/IR injury. Gene ontology analysis indicated that the calcium signaling pathway and PI3KCA(PI3K) were selected. Immunofluorescence staining and western blot exposed that PI3K was activated by allicin during MI/R injury. Fura-2AM staining revealed that the PI3K -mediated GRK2/PLC-γ/IP3R pathway may be involved in the protective effect of allicin on MI/R injury. Conclusions: Allicin has a protective effect on MI/R injury. This effect might be associated with the inhibition of Ca2+ overload-induced apoptosis and the inhibition of the PI3K -mediated GRK2/PLC-γ/IP3R signaling pathway.
Collapse
Affiliation(s)
- Tong Gao
- Graduate School of Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing 100730, China.,Department of Integrative Medicine Cardiology, China-Japan Friendship Hospital, Beijing 100029, China
| | - Peng Yang
- Department of Integrative Medicine Cardiology, China-Japan Friendship Hospital, Beijing 100029, China
| | - Dongliang Fu
- Department of Integrative Medicine Cardiology, China-Japan Friendship Hospital, Beijing 100029, China
| | - Mengru Liu
- Graduate School of Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing 100730, China.,Department of Integrative Medicine Cardiology, China-Japan Friendship Hospital, Beijing 100029, China
| | - Xinyi Deng
- Department of Integrative Medicine Cardiology, China-Japan Friendship Hospital, Beijing 100029, China.,Peking University China-Japan Friendship School of Clinical Medicine, Beijing 100029, China
| | - Mingjing Shao
- Department of Integrative Medicine Cardiology, China-Japan Friendship Hospital, Beijing 100029, China
| | - Jiangquan Liao
- Department of Integrative Medicine Cardiology, China-Japan Friendship Hospital, Beijing 100029, China
| | - Hong Jiang
- Department of Integrative Medicine Cardiology, China-Japan Friendship Hospital, Beijing 100029, China
| | - Xianlun Li
- Graduate School of Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing 100730, China.,Department of Integrative Medicine Cardiology, China-Japan Friendship Hospital, Beijing 100029, China.,Peking University China-Japan Friendship School of Clinical Medicine, Beijing 100029, China
| |
Collapse
|
11
|
Zhang Y, Xue Z, Hu S, Bai H, Wang J, Wang N. Chrysin Inhibits Pseudo-allergic Reaction by Suppressing Mitochondrial STAT3 Activation via MAS-Related GPR Family Member X2. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2021; 69:6569-6577. [PMID: 34100606 DOI: 10.1021/acs.jafc.1c02565] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Chrysin, one of the most pharmacologically active natural flavonoids, has been extracted from various plants. Mast cells are an important part of innate immunity-mediating anaphylaxis. Pseudo-allergic reactions are currently believed to be associated with the MAS-related GPR family member X2 (MrgX2). In this study, the anti-pseudo allergy effect of chrysin and its underlying mechanisms were studied in vitro and in vivo. Chrysin inhibited passive cutaneous anaphylaxis and systemic pseudo-allergy in vivo. LAD2 cell degranulation, calcium ion (Ca2+) influx, and adenosine 5'-triphosphate (ATP) content were significantly suppressed in a dose-dependent manner. Chrysin suppressed pseudo-allergic reactions through the PLC/IP3/Ca2+ and ERK/STAT3 serine 727 pathways downstream of MrgX2. Therefore, mitochondrial ATP, but not glycolysis, is vital for pseudo-allergic reactions mediated by MrgX2. This study provides new insights for the treatment of pseudo-allergy.
Collapse
Affiliation(s)
- Yongjing Zhang
- School of Pharmacy, Xi'an Jiaotong University, Xi'an 710049, China
| | - Zhuoyin Xue
- School of Pharmacy, Xi'an Jiaotong University, Xi'an 710049, China
| | - Shiling Hu
- School of Pharmacy, Xi'an Jiaotong University, Xi'an 710049, China
| | - Haoyun Bai
- School of Pharmacy, Xi'an Jiaotong University, Xi'an 710049, China
| | - Jue Wang
- School of Pharmacy, Xi'an Jiaotong University, Xi'an 710049, China
| | - Nan Wang
- School of Pharmacy, Xi'an Jiaotong University, Xi'an 710049, China
- Pazhou Lab, Guangzhou 510330, China
| |
Collapse
|
12
|
On the Mechanism of Cardioprotective Effect of Fabomotizole in Alcoholic Cardiomyopathy. Bull Exp Biol Med 2021; 171:41-44. [PMID: 34050832 DOI: 10.1007/s10517-021-05168-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Indexed: 10/21/2022]
Abstract
The molecular mechanisms underlying the cardioprotective effect of fabomotizole were studied using the translational rat model of alcoholic cardiomyopathy developed by us. It was shown that intraperitoneal administration of fabomotizole (15 mg/kg) for 28 days to animals with alcoholic cardiomyopathy contributes to normalization of the expression of mRNA of genes of regulatory proteins СаМ (p=0.00001), Ерас1 (p=0.021), and Ерас2 (p=0.018) and receptors RyR2 (p=0.0031) and IP3R2 (p=0.006) in the myocardium of the myocardium of the left ventricle that is enhanced in control animals (p<0.05). These changes were accompanied by echocardiographically documented decrease in the degree of left ventricle remodeling and improvement of its inotropic function.
Collapse
|
13
|
Kozhevnikova LM, Barchukov VV, Semenova NP, Vititnova MB, Kryzhanovskii SA. Studies of Molecular Mechanisms Underlying Cardioprotective Action of the ALM-802 Compound. Bull Exp Biol Med 2021; 170:312-315. [PMID: 33452980 DOI: 10.1007/s10517-021-05058-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Indexed: 10/22/2022]
Abstract
The mechanisms underlying cardioprotective activity of compound ALM-802 were studied in experiments on rats with chronic post-infarction heart failure. Real-time PCR showed that compound ALM-802 (daily intraperitoneal injections in a dose of 2 mg/kg for 28 days starting from day 91 after myocardial infarction modeling) restored the expression of genes encoding β1- (p=0.00001) and β2-adrenoreceptors (p=0.01) and type 2 ryanodine receptors (p=0.008) in the myocardium that was reduced in control animals. These effects can serve as the basis for the ability of the compound to reduce the intensity of remodeling and increase the inotropic function of the left heart ventricle shown earlier in this model.
Collapse
Affiliation(s)
- L M Kozhevnikova
- V. V. Zakusov Research Institute of Pharmacology, Moscow, Russia.,Research Institute of General Pathology and Pathophysiology, Moscow, Russia
| | - V V Barchukov
- V. V. Zakusov Research Institute of Pharmacology, Moscow, Russia
| | - N P Semenova
- Research Institute of General Pathology and Pathophysiology, Moscow, Russia
| | - M B Vititnova
- V. V. Zakusov Research Institute of Pharmacology, Moscow, Russia.
| | | |
Collapse
|
14
|
Parys JB, Bultynck G, Vervliet T. IP 3 Receptor Biology and Endoplasmic Reticulum Calcium Dynamics in Cancer. PROGRESS IN MOLECULAR AND SUBCELLULAR BIOLOGY 2021; 59:215-237. [PMID: 34050869 DOI: 10.1007/978-3-030-67696-4_11] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Intracellular Ca2+ signaling regulates a plethora of cellular functions. A central role in these processes is reserved for the inositol 1,4,5-trisphosphate receptor (IP3R), a ubiquitously expressed Ca2+-release channel, mainly located in the endoplasmic reticulum (ER). Three IP3R isoforms (IP3R1, IP3R2 and IP3R3) exist, encoded respectively by ITPR1, ITPR2 and ITPR3. The proteins encoded by these genes are each about 2700 amino acids long and assemble into large tetrameric channels, which form the target of many regulatory proteins, including several tumor suppressors and oncogenes. Due to the important role of the IP3Rs in cell function, their dysregulation is linked to multiple pathologies. In this review, we highlight the complex role of the IP3R in cancer, as it participates in most of the so-called "hallmarks of cancer". In particular, the IP3R directly controls cell death and cell survival decisions via regulation of autophagy and apoptosis. Moreover, the IP3R impacts cellular proliferation, migration and invasion. Typical examples of the role of the IP3Rs in these various processes are discussed. The relative levels of the IP3R isoforms expressed and their subcellular localization, e.g. at the ER-mitochondrial interface, is hereby important. Finally, evidence is provided about how the knowledge of the regulation of the IP3R by tumor suppressors and oncogenes can be exploited to develop novel therapeutic approaches to fight cancer.
Collapse
Affiliation(s)
- Jan B Parys
- Laboratory for Molecular and Cellular Signaling, Department of Cellular and Molecular Medicine & Leuven Cancer Institute, KU Leuven, Leuven, Belgium.
| | - Geert Bultynck
- Laboratory for Molecular and Cellular Signaling, Department of Cellular and Molecular Medicine & Leuven Cancer Institute, KU Leuven, Leuven, Belgium
| | - Tim Vervliet
- Laboratory for Molecular and Cellular Signaling, Department of Cellular and Molecular Medicine & Leuven Cancer Institute, KU Leuven, Leuven, Belgium
| |
Collapse
|
15
|
Liu X, Pan Z. Store-Operated Calcium Entry in the Cardiovascular System. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2021; 1349:303-333. [DOI: 10.1007/978-981-16-4254-8_14] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
|
16
|
Noble M, Lin QT, Sirko C, Houpt JA, Novello MJ, Stathopulos PB. Structural Mechanisms of Store-Operated and Mitochondrial Calcium Regulation: Initiation Points for Drug Discovery. Int J Mol Sci 2020; 21:E3642. [PMID: 32455637 PMCID: PMC7279490 DOI: 10.3390/ijms21103642] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2020] [Revised: 05/11/2020] [Accepted: 05/17/2020] [Indexed: 12/18/2022] Open
Abstract
Calcium (Ca2+) is a universal signaling ion that is essential for the life and death processes of all eukaryotes. In humans, numerous cell stimulation pathways lead to the mobilization of sarco/endoplasmic reticulum (S/ER) stored Ca2+, resulting in the propagation of Ca2+ signals through the activation of processes, such as store-operated Ca2+ entry (SOCE). SOCE provides a sustained Ca2+ entry into the cytosol; moreover, the uptake of SOCE-mediated Ca2+ by mitochondria can shape cytosolic Ca2+ signals, function as a feedback signal for the SOCE molecular machinery, and drive numerous mitochondrial processes, including adenosine triphosphate (ATP) production and distinct cell death pathways. In recent years, tremendous progress has been made in identifying the proteins mediating these signaling pathways and elucidating molecular structures, invaluable for understanding the underlying mechanisms of function. Nevertheless, there remains a disconnect between using this accumulating protein structural knowledge and the design of new research tools and therapies. In this review, we provide an overview of the Ca2+ signaling pathways that are involved in mediating S/ER stored Ca2+ release, SOCE, and mitochondrial Ca2+ uptake, as well as pinpoint multiple levels of crosstalk between these pathways. Further, we highlight the significant protein structures elucidated in recent years controlling these Ca2+ signaling pathways. Finally, we describe a simple strategy that aimed at applying the protein structural data to initiating drug design.
Collapse
Affiliation(s)
- Megan Noble
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, The University of Western Ontario, London, ON N6A5C1, Canada; (M.N.); (Q.-T.L.); (C.S.); (M.J.N.)
| | - Qi-Tong Lin
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, The University of Western Ontario, London, ON N6A5C1, Canada; (M.N.); (Q.-T.L.); (C.S.); (M.J.N.)
| | - Christian Sirko
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, The University of Western Ontario, London, ON N6A5C1, Canada; (M.N.); (Q.-T.L.); (C.S.); (M.J.N.)
| | - Jacob A. Houpt
- Department of Medicine, Schulich School of Medicine and Dentistry, The University of Western Ontario, London, ON N6A5C1, Canada;
| | - Matthew J. Novello
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, The University of Western Ontario, London, ON N6A5C1, Canada; (M.N.); (Q.-T.L.); (C.S.); (M.J.N.)
| | - Peter B. Stathopulos
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, The University of Western Ontario, London, ON N6A5C1, Canada; (M.N.); (Q.-T.L.); (C.S.); (M.J.N.)
| |
Collapse
|
17
|
Cardiomyocyte calcium handling in health and disease: Insights from in vitro and in silico studies. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2020; 157:54-75. [PMID: 32188566 DOI: 10.1016/j.pbiomolbio.2020.02.008] [Citation(s) in RCA: 63] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2019] [Revised: 12/31/2019] [Accepted: 02/29/2020] [Indexed: 02/07/2023]
Abstract
Calcium (Ca2+) plays a central role in cardiomyocyte excitation-contraction coupling. To ensure an optimal electrical impulse propagation and cardiac contraction, Ca2+ levels are regulated by a variety of Ca2+-handling proteins. In turn, Ca2+ modulates numerous electrophysiological processes. Accordingly, Ca2+-handling abnormalities can promote cardiac arrhythmias via various mechanisms, including the promotion of afterdepolarizations, ion-channel modulation and structural remodeling. In the last 30 years, significant improvements have been made in the computational modeling of cardiomyocyte Ca2+ handling under physiological and pathological conditions. However, numerous questions involving the Ca2+-dependent regulation of different macromolecular complexes, cross-talk between Ca2+-dependent regulatory pathways operating over a wide range of time scales, and bidirectional interactions between electrophysiology and mechanics remain to be addressed by in vitro and in silico studies. A better understanding of disease-specific Ca2+-dependent proarrhythmic mechanisms may facilitate the development of improved therapeutic strategies. In this review, we describe the fundamental mechanisms of cardiomyocyte Ca2+ handling in health and disease, and provide an overview of currently available computational models for cardiomyocyte Ca2+ handling. Finally, we discuss important uncertainties and open questions about cardiomyocyte Ca2+ handling and highlight how synergy between in vitro and in silico studies may help to answer several of these issues.
Collapse
|
18
|
Neshati Z, Schalij MJ, de Vries AAF. The proarrhythmic features of pathological cardiac hypertrophy in neonatal rat ventricular cardiomyocyte cultures. J Appl Physiol (1985) 2020; 128:545-553. [PMID: 31999526 DOI: 10.1152/japplphysiol.00420.2019] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Different factors may trigger arrhythmias in diseased hearts, including fibrosis, cardiomyocyte hypertrophy, hypoxia, and inflammation. This makes it difficult to establish the relative contribution of each of them to the occurrence of arrhythmias. Accordingly, in this study, we used an in vitro model of pathological cardiac hypertrophy (PCH) to investigate its proarrhythmic features and the underlying mechanisms independent of fibrosis or other PCH-related processes. Neonatal rat ventricular cardiomyocyte (nr-vCMC) monolayers were treated with phorbol 12-myristate 13-acetate (PMA) to create an in vitro model of PCH. The electrophysiological properties of PMA-treated and control monolayers were analyzed by optical mapping at day 9 of culture. PMA treatment led to a significant increase in cell size and total protein content. It also caused a reduction in sarcoplasmic/endoplasmic reticulum Ca2+ ATPase 2 level (32%) and an increase in natriuretic peptide A (42%) and α1-skeletal muscle actin (34%) levels, indicating that the hypertrophic response induced by PMA was, indeed, pathological in nature. PMA-treated monolayers showed increases in action potential duration (APD) and APD dispersion, and a decrease in conduction velocity (CV; APD30 of 306 ± 39 vs. 148 ± 18 ms, APD30 dispersion of 85 ± 19 vs. 22 ± 7 and CV of 10 ± 4 vs. 21 ± 2 cm/s in controls). Upon local 1-Hz stimulation, 53.6% of the PMA-treated cultures showed focal tachyarrhythmias based on triggered activity (n = 82), while the control group showed 4.3% tachyarrhythmias (n = 70). PMA-treated nr-vCMC cultures may, thus, represent a well-controllable in vitro model for testing new therapeutic interventions targeting specific aspects of hypertrophy-associated arrhythmias.NEW & NOTEWORTHY Phorbol 12-myristate 13-acetate (PMA) treatment of neonatal rat ventricular cardiomyocytes (nr-vCMCs) led to induction of many significant features of pathological cardiac hypertrophy (PCH), including action potential duration prolongation and dispersion, which provided enough time and depolarizing force for formation of early afterdepolarization (EAD)-induced focal tachyarrhythmias. PMA-treated nr-vCMCs represent a well-controllable in vitro model, which mostly resembles to moderate left ventricular hypertrophy (LVH) rather than severe LVH, in which generation of a reentry is the putative mechanism of its arrhythmias.
Collapse
Affiliation(s)
- Zeinab Neshati
- Zeinab Neshati, Department of Biology, Faculty of Science, Ferdowsi University of Mashhad, Mashhad, Iran.,Laboratory of Experimental Cardiology, Department of Cardiology, Heart Lung Center Leiden, Leiden University Medical Center, Leiden, The Netherlands
| | - Martin J Schalij
- Laboratory of Experimental Cardiology, Department of Cardiology, Heart Lung Center Leiden, Leiden University Medical Center, Leiden, The Netherlands
| | - Antoine A F de Vries
- Laboratory of Experimental Cardiology, Department of Cardiology, Heart Lung Center Leiden, Leiden University Medical Center, Leiden, The Netherlands
| |
Collapse
|
19
|
Abstract
The aim of this chapter is to discuss evidence concerning the many roles of calcium ions, Ca2+, in cell signaling pathways that control heart function. Before considering details of these signaling pathways, the control of contraction in ventricular muscle by Ca2+ transients accompanying cardiac action potentials is first summarized, together with a discussion of how myocytes from the atrial and pacemaker regions of the heart diverge from this basic scheme. Cell signaling pathways regulate the size and timing of the Ca2+ transients in the different heart regions to influence function. The simplest Ca2+ signaling elements involve enzymes that are regulated by cytosolic Ca2+. Particularly important examples to be discussed are those that are stimulated by Ca2+, including Ca2+-calmodulin-dependent kinase (CaMKII), Ca2+ stimulated adenylyl cyclases, Ca2+ stimulated phosphatase and NO synthases. Another major aspect of Ca2+ signaling in the heart concerns actions of the Ca2+ mobilizing agents, inositol trisphosphate (IP3), cADP-ribose (cADPR) and nicotinic acid adenine dinucleotide phosphate, (NAADP). Evidence concerning roles of these Ca2+ mobilizing agents in different regions of the heart is discussed in detail. The focus of the review will be on short term regulation of Ca2+ transients and contractile function, although it is recognized that Ca2+ regulation of gene expression has important long term functional consequences which will also be briefly discussed.
Collapse
|
20
|
Singh N, Adlakha N. A mathematical model for interdependent calcium and inositol 1,4,5-trisphosphate in cardiac myocyte. ACTA ACUST UNITED AC 2019. [DOI: 10.1007/s13721-019-0198-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
|
21
|
Hohendanner F, Heinzel FR, Blaschke F, Pieske BM, Haverkamp W, Boldt HL, Parwani AS. Pathophysiological and therapeutic implications in patients with atrial fibrillation and heart failure. Heart Fail Rev 2019; 23:27-36. [PMID: 29038991 DOI: 10.1007/s10741-017-9657-9] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Heart failure and atrial fibrillation are common and responsible for significant mortality of patients. Both share the same risk factors like hypertension, ischemic heart disease, diabetes, obesity, arteriosclerosis, and age. A variety of microscopic and macroscopic changes favor the genesis of atrial fibrillation in patients with preexisting heart failure, altered subcellular Ca2+ homeostasis leading to increased cellular automaticity as well as concomitant fibrosis that are induced by pressure/volume overload and altered neurohumoral states. Atrial fibrillation itself promotes clinical deterioration of patients with preexisting heart failure as atrial contraction significantly contributes to ventricular filling. In addition, atrial fibrillation induced tachycardia can even further compromise ventricular function by inducing tachycardiomyopathy. Even though evidence has been provided that atrial functions significantly and independently of confounding ventricular pathologies, correlate with mortality of heart failure patients, rate and rhythm controls have been shown to be of equal effectiveness in improving mortality. Yet, it also has been shown that cohorts of patients with heart failure benefit from a rhythm control concept regarding symptom control and hospitalization. To date, amiodarone is the most feasible approach to restore sinus rhythm, yet its use is limited by its extensive side-effect profile. In addition, other therapies like catheter-based pulmonary vein isolation are of increasing importance. A wide range of heart failure-specific therapies are available with mixed impact on new onset or perpetuation of atrial fibrillation. This review highlights pathophysiological concepts and possible therapeutic approaches to treat patients with heart failure at risk for or with atrial fibrillation.
Collapse
Affiliation(s)
- Felix Hohendanner
- Department of Cardiology, Charité University Medicine, Campus Virchow-Klinikum, Augustenburger Platz 1, 13353, Berlin, Germany. .,Partner Site Berlin, German Center for Cardiovascular Research (DZHK), Berlin, Germany.
| | - F R Heinzel
- Department of Cardiology, Charité University Medicine, Campus Virchow-Klinikum, Augustenburger Platz 1, 13353, Berlin, Germany.,Partner Site Berlin, German Center for Cardiovascular Research (DZHK), Berlin, Germany
| | - F Blaschke
- Department of Cardiology, Charité University Medicine, Campus Virchow-Klinikum, Augustenburger Platz 1, 13353, Berlin, Germany.,Partner Site Berlin, German Center for Cardiovascular Research (DZHK), Berlin, Germany
| | - B M Pieske
- Department of Cardiology, Charité University Medicine, Campus Virchow-Klinikum, Augustenburger Platz 1, 13353, Berlin, Germany.,Partner Site Berlin, German Center for Cardiovascular Research (DZHK), Berlin, Germany.,Department of Internal Medicine and Cardiology, German Heart Center, 13353, Berlin, Germany
| | - W Haverkamp
- Department of Cardiology, Charité University Medicine, Campus Virchow-Klinikum, Augustenburger Platz 1, 13353, Berlin, Germany.,Partner Site Berlin, German Center for Cardiovascular Research (DZHK), Berlin, Germany
| | - H L Boldt
- Department of Cardiology, Charité University Medicine, Campus Virchow-Klinikum, Augustenburger Platz 1, 13353, Berlin, Germany.,Partner Site Berlin, German Center for Cardiovascular Research (DZHK), Berlin, Germany
| | - A S Parwani
- Department of Cardiology, Charité University Medicine, Campus Virchow-Klinikum, Augustenburger Platz 1, 13353, Berlin, Germany.,Partner Site Berlin, German Center for Cardiovascular Research (DZHK), Berlin, Germany
| |
Collapse
|
22
|
Singh N, Adlakha N. Three dimensional coupled reaction–diffusion modeling of calcium and inositol 1,4,5-trisphosphate dynamics in cardiomyocytes. RSC Adv 2019; 9:42459-42469. [PMID: 35542883 PMCID: PMC9076935 DOI: 10.1039/c9ra06929a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2019] [Accepted: 11/28/2019] [Indexed: 11/30/2022] Open
Abstract
Nanoparticles have shown great promise in improving cancer treatment efficacy by changing the intracellular calcium level through activation of intracellular mechanisms. One of the mechanisms of the killing of the cancerous cell by a nanoparticle is through elevation of the intracellular calcium level. Evidence accumulated over the past decade indicates a pivotal role for the IP3 receptor mediated Ca2+ release in the regulation of the cytosolic and the nuclear Ca2+ signals. There have been various studies done suggesting the role of IP3 receptors (IP3R) and IP3 production and degradation in cardiomyocytes. In the present work, we have proposed a three-dimensional unsteady-state mathematical model to describe the mechanism of cardiomyocytes which focuses on evaluation of various parameters that affect these coupled dynamics and elevate the cytosolic calcium concentration which can be helpful to search for novel therapies to cure these malignancies by targeting the complex calcium signaling process in cardiomyocytes. Our study suggests that there are other factors involved in this signaling which can increase the calcium level, which can help in finding treatment for cancer. The cytosolic calcium level may be controlled by IP3 signaling, leak, source influx of calcium (σ) and maximum production of IP3 (VP). We believe that the proposed model suggests new insight into finding treatment for cancer in cardiomyocytes through elevation of the cytosolic Ca2+ concentration by various parameters like leak, σ, VP and especially by other complex cell signaling dynamics, namely IP3 dynamics. We propose a three-dimensional unsteady-state mathematical model to describe the mechanism of cardiomyocytes.![]()
Collapse
Affiliation(s)
- Nisha Singh
- Applied Mathematics and Humanities Department
- SVNIT
- Surat
- India
| | - Neeru Adlakha
- Applied Mathematics and Humanities Department
- SVNIT
- Surat
- India
| |
Collapse
|
23
|
Mhatre KN, Wakula P, Klein O, Bisping E, Völkl J, Pieske B, Heinzel FR. Crosstalk between FGF23- and angiotensin II-mediated Ca 2+ signaling in pathological cardiac hypertrophy. Cell Mol Life Sci 2018; 75:4403-4416. [PMID: 30062428 PMCID: PMC11105615 DOI: 10.1007/s00018-018-2885-x] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2018] [Revised: 07/16/2018] [Accepted: 07/19/2018] [Indexed: 02/07/2023]
Abstract
Heart failure (HF) manifestation and progression are driven by systemic activation of neuroendocrine signaling cascades, such as the renin-angiotensin aldosterone system (RAAS). Fibroblast growth factor 23 (FGF23), an endocrine hormone, is linked to HF and cardiovascular mortality. It is also a mediator of left-ventricular hypertrophy (LVH). In vivo, high circulating levels of FGF23 are associated with an altered systemic RAAS response. FGF23 is proposed to trigger pathological signaling mediated by Ca2+-regulated transcriptional pathways. In the present study, we investigated Ca2+-dependent signaling of FGF23 in ventricular cardiomyocytes and its association with angiotensin II (ATII). In neonatal rat ventricular myocytes (NRVMs), both ATII and FGF23 induced hypertrophy as observed by an increase in cell area and hypertrophic gene expression. Furthermore, FGF23 activates nuclear Ca2+-regulated CaMKII-HDAC4 pathway, similar to ATII. In addition to a global increase in cytoplasmic Ca2+, FGF23, like ATII, induced inositol 1, 4, 5-triphosphate (IP3)-induced Ca2+ release from the nucleoplasmic Ca2+ store, associated with cellular hypertrophy. Interestingly, ATII receptor antagonist, losartan, significantly attenuated FGF23-induced changes in Ca2+ homeostasis and cellular hypertrophy suggesting an involvement of ATII receptor-mediated signaling. In addition, application of FGF23 increased intracellular expression of ATII peptide and its secretion in NRVMs, confirming the participation of ATII. In conclusion, FGF23 and ATII share a common mechanism of IP3-nuclear Ca2+-dependent cardiomyocyte hypertrophy. FGF23-mediated cellular hypertrophy is associated with increased production and secretion of ATII by cardiomyocytes. These findings indicate a pathophysiological role of the cellular angiotensin system in FGF23-induced hypertrophy in ventricular cardiomyocytes.
Collapse
Affiliation(s)
- Ketaki N Mhatre
- Department of Internal Medicine and Cardiology, Charité University Medicine, Campus Virchow-Klinikum, 13353, Berlin, Germany
- Department of Cardiology, Medical University Graz, Auenbruggerplatz 15, 8036, Graz, Austria
| | - Paulina Wakula
- Department of Internal Medicine and Cardiology, Charité University Medicine, Campus Virchow-Klinikum, 13353, Berlin, Germany
| | - Oliver Klein
- Department of Internal Medicine and Cardiology, Charité University Medicine, Campus Virchow-Klinikum, 13353, Berlin, Germany
| | - Egbert Bisping
- Department of Cardiology, Medical University Graz, Auenbruggerplatz 15, 8036, Graz, Austria
| | - Jakob Völkl
- Department of Internal Medicine and Cardiology, Charité University Medicine, Campus Virchow-Klinikum, 13353, Berlin, Germany
| | - Burkert Pieske
- Department of Internal Medicine and Cardiology, Charité University Medicine, Campus Virchow-Klinikum, 13353, Berlin, Germany
- German Center for Cardiovascular Research (DZHK), Berlin, Germany
- Department of Internal Medicine and Cardiology, German Heart Center, 13353, Berlin, Germany
| | - Frank R Heinzel
- Department of Internal Medicine and Cardiology, Charité University Medicine, Campus Virchow-Klinikum, 13353, Berlin, Germany.
- German Center for Cardiovascular Research (DZHK), Berlin, Germany.
| |
Collapse
|
24
|
Blanch i Salvador J, Egger M. Obstruction of ventricular Ca 2+ -dependent arrhythmogenicity by inositol 1,4,5-trisphosphate-triggered sarcoplasmic reticulum Ca 2+ release. J Physiol 2018; 596:4323-4340. [PMID: 30004117 PMCID: PMC6138286 DOI: 10.1113/jp276319] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2018] [Accepted: 07/06/2018] [Indexed: 11/08/2022] Open
Abstract
KEY POINTS Augmented inositol 1,4,5-trisphosphate (IP3 ) receptor (IP3 R2) expression has been linked to a variety of cardiac pathologies. Although cardiac IP3 R2 function has been in the focus of research for some time, a detailed understanding of its potential role in ventricular myocyte excitation-contraction coupling under pathophysiological conditions remains elusive. The present study focuses on mechanisms of IP3 R2-mediated sarcoplasmic reticulum (SR)-Ca2+ release in ventricular excitation-contraction coupling under IP3 R2-overexpressing conditions by studying intracellular Ca2+ events. We report that, upon IP3 R2 overexpression in ventricular myocytes, IP3 -induced Ca2+ release (IP3 ICR) modulates the SR-Ca2+ content via "eventless" SR-Ca2+ release, affecting the global SR-Ca2+ leak. Thus, IP3 R2 activation could act as a SR-Ca2+ gateway mechanism to escape ominous SR-Ca2+ overload. Our approach unmasks a so far unrecognized mechanism by which "eventless" IP3 ICR plays a protective role against ventricular Ca2+ -dependent arrhythmogenicity. ABSTRACT Augmented inositol 1,4,5-trisphosphate (IP3 ) receptor (IP3 R2) function has been linked to a variety of cardiac pathologies including cardiac arrhythmias. The functional role of IP3 -induced Ca2+ release (IP3 ICR) within ventricular excitation-contraction coupling (ECC) remains elusive. As part of pathophysiological cellular remodelling, IP3 R2s are overexpressed and have been repeatedly linked to enhanced Ca2+ -dependent arrhythmogenicity. In this study we test the hypothesis that an opposite scenario might be plausible in which IP3 ICR is part of an ECC protecting mechanism, resulting in a Ca2+ -dependent anti-arrhythmogenic response on the cellular scale. IP3 R2 activation was triggered via endothelin-1 or IP3 -salt application in single ventricular myocytes from a cardiac-specific IP3 R type 2 overexpressing mouse model. Upon IP3 R2 overexpression, IP3 R activation reduced Ca2+ -wave occurrence (46 vs. 21.72%; P < 0.001) while its block increased SR-Ca2+ content (∼29.4% 2-aminoethoxydiphenyl borate, ∼16.4% xestospongin C; P < 0.001), suggesting an active role of IP3 ICR in SR-Ca2+ content regulation and anti-arrhythmogenic function. Pharmacological separation of ryanodine receptor RyR2 and IP3 R2 functions and two-dimensional Ca2+ event analysis failed to identify local IP3 ICR events (Ca2+ puffs). SR-Ca2+ leak measurements revealed that under pathophysiological conditions, "eventless" SR-Ca2+ efflux via enhanced IP3 ICR maintains the SR-Ca2+ content below Ca2+ spark threshold, preventing aberrant SR-Ca2+ release and resulting in a protective mechanism against SR-Ca2+ overload and arrhythmias. Our results support a so far unrecognized modulatory mechanism in ventricular myocytes working in an anti-arrhythmogenic fashion.
Collapse
Affiliation(s)
| | - Marcel Egger
- Department of PhysiologyUniversity of BernBuehlplatz 5CH‐3012BernSwitzerland
| |
Collapse
|
25
|
Morotti S, Grandi E. Quantitative systems models illuminate arrhythmia mechanisms in heart failure: Role of the Na + -Ca 2+ -Ca 2+ /calmodulin-dependent protein kinase II-reactive oxygen species feedback. WILEY INTERDISCIPLINARY REVIEWS-SYSTEMS BIOLOGY AND MEDICINE 2018; 11:e1434. [PMID: 30015404 DOI: 10.1002/wsbm.1434] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2018] [Revised: 05/29/2018] [Accepted: 06/16/2018] [Indexed: 12/22/2022]
Abstract
Quantitative systems modeling aims to integrate knowledge in different research areas with models describing biological mechanisms and dynamics to gain a better understanding of complex clinical syndromes. Heart failure (HF) is a chronic complex cardiac disease that results from structural or functional disorders impairing the ability of the ventricle to fill with or eject blood. Highly interactive and dynamic changes in mechanical, structural, neurohumoral, metabolic, and electrophysiological properties collectively predispose the failing heart to cardiac arrhythmias, which are responsible for about a half of HF deaths. Multiscale cardiac modeling and simulation integrate structural and functional data from HF experimental models and patients to improve our mechanistic understanding of this complex arrhythmia syndrome. In particular, they allow investigating how disease-induced remodeling alters the coupling of electrophysiology, Ca2+ and Na+ handling, contraction, and energetics that lead to rhythm derangements. The Ca2+ /calmodulin-dependent protein kinase II, which expression and activity are enhanced in HF, emerges as a critical hub that modulates the feedbacks between these various subsystems and promotes arrhythmogenesis. This article is categorized under: Physiology > Mammalian Physiology in Health and Disease Models of Systems Properties and Processes > Mechanistic Models Models of Systems Properties and Processes > Cellular Models Models of Systems Properties and Processes > Organ, Tissue, and Physiological Models.
Collapse
Affiliation(s)
- Stefano Morotti
- Department of Pharmacology, University of California Davis, Davis, California
| | - Eleonora Grandi
- Department of Pharmacology, University of California Davis, Davis, California
| |
Collapse
|
26
|
Cellular mechanisms of metabolic syndrome-related atrial decompensation in a rat model of HFpEF. J Mol Cell Cardiol 2017; 115:10-19. [PMID: 29289652 DOI: 10.1016/j.yjmcc.2017.12.012] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/11/2017] [Revised: 11/30/2017] [Accepted: 12/27/2017] [Indexed: 11/23/2022]
Abstract
Heart failure (HF) with preserved ejection fraction (HFpEF) is present in about 50% of HF patients. Atrial remodeling is common in HFpEF and associated with increased mortality. We postulate that atrial remodeling is associated with atrial dysfunction in vivo related to alterations in cardiomyocyte Calcium (Ca) signaling and remodeling. We examined atrial function in vivo and Ca transients (CaT) (Fluo4-AM, field stim) in atrial cardiomyocytes of ZSF-1 rats without (Ln; lean hypertensive) and with metabolic syndrome (Ob; obese, hypertensive, diabetic) and HFpEF. RESULTS At 21weeks Ln showed an increased left ventricular (LV) mass and left ventricular end-diastolic pressure (LVEDP), but unchanged left atrial (LA) size and preserved atrial ejection fraction vs. wild-type (WT). CaT amplitude in atrial cardiomyocytes was increased in Ln (2.9±0.2 vs. 2.3±0.2F/F0 in WT; n=22 cells/group; p<0.05). Studying subcellular Ca release in more detail, we found that local central cytosolic CaT amplitude was increased, while subsarcolemmal CaT amplitudes remained unchanged. Moreover, Sarcoplasmic reticulum (SR) Ca content (caffeine) was preserved while Ca spark frequency and tetracaine-dependent SR Ca leak were significantly increased in Ln. Ob mice developed a HFpEF phenotype in vivo, LA area was significantly increased and atrial in vivo function was impaired, despite increased atrial CaT amplitudes in vitro (2.8±0.2; p<0.05 vs. WT). Ob cells showed alterations of the tubular network possibly contributing to the observed phenotype. CaT kinetics as well as SR Ca in Ob were not significantly different from WT, but SR Ca leak remained increased. Angiotensin II (Ang II) reduced in vitro cytosolic CaT amplitudes and let to active nuclear Ca release in Ob but not in Ln or WT. SUMMARY In hypertensive ZSF-1 rats, a possibly compensatory increase of cytosolic CaT amplitude and increased SR Ca leak precede atrial remodeling and HFpEF. Atrial remodeling in ZSF-1 HFpEF is associated with an altered tubular network in-vitro and atrial contractile dysfunction in vivo, indicating insufficient compensation. Atrial cardiomyocyte dysfunction in vitro is induced by the addition of angiotensin II.
Collapse
|
27
|
Dewenter M, von der Lieth A, Katus HA, Backs J. Calcium Signaling and Transcriptional Regulation in Cardiomyocytes. Circ Res 2017; 121:1000-1020. [DOI: 10.1161/circresaha.117.310355] [Citation(s) in RCA: 110] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Calcium (Ca
2+
) is a universal regulator of various cellular functions. In cardiomyocytes, Ca
2+
is the central element of excitation–contraction coupling, but also impacts diverse signaling cascades and influences the regulation of gene expression, referred to as excitation–transcription coupling. Disturbances in cellular Ca
2+
-handling and alterations in Ca
2+
-dependent gene expression patterns are pivotal characteristics of failing cardiomyocytes, with several excitation–transcription coupling pathways shown to be critically involved in structural and functional remodeling processes. Thus, targeting Ca
2+
-dependent transcriptional pathways might offer broad therapeutic potential. In this article, we (1) review cytosolic and nuclear Ca
2+
dynamics in cardiomyocytes with respect to their impact on Ca
2+
-dependent signaling, (2) give an overview on Ca
2+
-dependent transcriptional pathways in cardiomyocytes, and (3) discuss implications of excitation–transcription coupling in the diseased heart.
Collapse
Affiliation(s)
- Matthias Dewenter
- From the Department of Molecular Cardiology and Epigenetics (M.D., A.v.d.L., J.B.) and Department of Cardiology (H.A.K.), Heidelberg University, Germany; and DZHK (German Centre for Cardiovascular Research), Partner Site Heidelberg/Mannheim, Germany (M.D., A.v.d.L., H.A.K., J.B.)
| | - Albert von der Lieth
- From the Department of Molecular Cardiology and Epigenetics (M.D., A.v.d.L., J.B.) and Department of Cardiology (H.A.K.), Heidelberg University, Germany; and DZHK (German Centre for Cardiovascular Research), Partner Site Heidelberg/Mannheim, Germany (M.D., A.v.d.L., H.A.K., J.B.)
| | - Hugo A. Katus
- From the Department of Molecular Cardiology and Epigenetics (M.D., A.v.d.L., J.B.) and Department of Cardiology (H.A.K.), Heidelberg University, Germany; and DZHK (German Centre for Cardiovascular Research), Partner Site Heidelberg/Mannheim, Germany (M.D., A.v.d.L., H.A.K., J.B.)
| | - Johannes Backs
- From the Department of Molecular Cardiology and Epigenetics (M.D., A.v.d.L., J.B.) and Department of Cardiology (H.A.K.), Heidelberg University, Germany; and DZHK (German Centre for Cardiovascular Research), Partner Site Heidelberg/Mannheim, Germany (M.D., A.v.d.L., H.A.K., J.B.)
| |
Collapse
|
28
|
Sartiani L, Bucciantini M, Spinelli V, Leri M, Natalello A, Nosi D, Maria Doglia S, Relini A, Penco A, Giorgetti S, Gerace E, Mannaioni G, Bellotti V, Rigacci S, Cerbai E, Stefani M. Biochemical and Electrophysiological Modification of Amyloid Transthyretin on Cardiomyocytes. Biophys J 2017; 111:2024-2038. [PMID: 27806283 DOI: 10.1016/j.bpj.2016.09.010] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2016] [Revised: 07/26/2016] [Accepted: 09/06/2016] [Indexed: 12/26/2022] Open
Abstract
Transthyretin (TTR) amyloidoses are familial or sporadic degenerative conditions that often feature heavy cardiac involvement. Presently, no effective pharmacological therapy for TTR amyloidoses is available, mostly due to a substantial lack of knowledge about both the molecular mechanisms of TTR aggregation in tissue and the ensuing functional and viability modifications that occur in aggregate-exposed cells. TTR amyloidoses are of particular interest regarding the relation between functional and viability impairment in aggregate-exposed excitable cells such as peripheral neurons and cardiomyocytes. In particular, the latter cells provide an opportunity to investigate in parallel the electrophysiological and biochemical modifications that take place when the cells are exposed for various lengths of time to variously aggregated wild-type TTR, a condition that characterizes senile systemic amyloidosis. In this study, we investigated biochemical and electrophysiological modifications in cardiomyocytes exposed to amyloid oligomers or fibrils of wild-type TTR or to its T4-stabilized form, which resists tetramer disassembly, misfolding, and aggregation. Amyloid TTR cytotoxicity results in mitochondrial potential modification, oxidative stress, deregulation of cytoplasmic Ca2+ levels, and Ca2+ cycling. The altered intracellular Ca2+ cycling causes a prolongation of the action potential, as determined by whole-cell recordings of action potentials on isolated mouse ventricular myocytes, which may contribute to the development of cellular arrhythmias and conduction alterations often seen in patients with TTR amyloidosis. Our data add information about the biochemical, functional, and viability alterations that occur in cardiomyocytes exposed to aggregated TTR, and provide clues as to the molecular and physiological basis of heart dysfunction in sporadic senile systemic amyloidosis and familial amyloid cardiomyopathy forms of TTR amyloidoses.
Collapse
Affiliation(s)
- Laura Sartiani
- Department of Neuroscience, Psychology, Drug Research and Child Health, University of Florence, Florence, Italy; Center of Molecular Medicine, University of Florence, Florence, Italy
| | - Monica Bucciantini
- Department of Biomedical, Experimental and Clinical Sciences "Mario Serio,", University of Florence, Florence, Italy; Research Centre on the Molecular Basis of Neurodegeneration, University of Florence, Florence, Italy.
| | - Valentina Spinelli
- Department of Neuroscience, Psychology, Drug Research and Child Health, University of Florence, Florence, Italy; Center of Molecular Medicine, University of Florence, Florence, Italy
| | - Manuela Leri
- Department of Biomedical, Experimental and Clinical Sciences "Mario Serio,", University of Florence, Florence, Italy
| | - Antonino Natalello
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Milan, Italy
| | - Daniele Nosi
- Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy
| | - Silvia Maria Doglia
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Milan, Italy
| | | | - Amanda Penco
- Department of Physics, University of Genoa, Genoa, Italy
| | - Sofia Giorgetti
- Department of Molecular Medicine, Institute of Biochemistry, University of Pavia, Pavia, Italy
| | - Elisabetta Gerace
- Department of Health Science, University of Florence, Florence, Italy
| | - Guido Mannaioni
- Department of Neuroscience, Psychology, Drug Research and Child Health, University of Florence, Florence, Italy
| | - Vittorio Bellotti
- Department of Molecular Medicine, Institute of Biochemistry, University of Pavia, Pavia, Italy; Wolfson Drug Discovery Unit, Centre for Amyloidosis and Acute Phase Proteins, Division of Medicine, University College London, London, United Kingdom
| | - Stefania Rigacci
- Department of Biomedical, Experimental and Clinical Sciences "Mario Serio,", University of Florence, Florence, Italy
| | - Elisabetta Cerbai
- Department of Neuroscience, Psychology, Drug Research and Child Health, University of Florence, Florence, Italy; Center of Molecular Medicine, University of Florence, Florence, Italy; Research Centre on the Molecular Basis of Neurodegeneration, University of Florence, Florence, Italy
| | - Massimo Stefani
- Department of Biomedical, Experimental and Clinical Sciences "Mario Serio,", University of Florence, Florence, Italy; Research Centre on the Molecular Basis of Neurodegeneration, University of Florence, Florence, Italy
| |
Collapse
|
29
|
Multiple H + sensors mediate the extracellular acidification-induced [Ca 2+] i elevation in cultured rat ventricular cardiomyocytes. Sci Rep 2017; 7:44951. [PMID: 28332558 PMCID: PMC5362981 DOI: 10.1038/srep44951] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2016] [Accepted: 02/16/2017] [Indexed: 02/04/2023] Open
Abstract
Acidosis has been known to cause “Ca2+ transients”, however, the mechanism is still uncertain. Here, we demonstrated that multiple H+ sensors, such as ASICs, TRPV1 and proton-sensing G protein coupled receptors (GPCRs) are involved in extracellular acidification-induced intracellular calcium ([Ca2+]i) elevation. By using calcium imaging measures, we observed that both ASIC and TRPV1 channels inhibitors suppressed the [Ca2+]i elevation induced by extracellular acidosis in cultured rat cardiac myocytes. Then, both channels mRNA and proteins were identified by RT-PCR, western blotting and immunofluorescence. ASIC-like and TRPV1-like currents were induced by extracellular acidification, suggesting that functional ASIC and TRPV1 channels jointly mediated extracellular calcium entry. Furthermore, either pre-exhaustion of sarcoplasmic reticulum (SR) Ca2+ with thapsigargin or IP3 receptor blocker 2-APB or PLC inhibitor U73122 significantly attenuated the elevation of [Ca2+]i, indicating that the intracellular Ca2+ stores and the PLC-IP3 signaling also contributed to the acidosis-induced elevation of [Ca2+]i. By using genetic and pharmacological approaches, we identified that ovarian cancer G protein-coupled receptor 1 (OGR1) might be another main component in acidosis-induced release of [Ca2+]i. These results suggest that multiple H+-sensitive receptors are involved in “Ca2+ transients” induced by acidosis in the heart.
Collapse
|
30
|
Tissue Specificity: Store-Operated Ca 2+ Entry in Cardiac Myocytes. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 993:363-387. [PMID: 28900924 DOI: 10.1007/978-3-319-57732-6_19] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Calcium (Ca2+) is a key regulator of cardiomyocyte contraction. The Ca2+ channels, pumps, and exchangers responsible for the cyclical cytosolic Ca2+ signals that underlie contraction are well known. In addition to those Ca2+ signaling components responsible for contraction, it has been proposed that cardiomyocytes express channels that promote the influx of Ca2+ from the extracellular milieu to the cytosol in response to depletion of intracellular Ca2+ stores. With non-excitable cells, this store-operated Ca2+ entry (SOCE) is usually easily demonstrated and is essential for prolonging cellular Ca2+ signaling and for refilling depleted Ca2+ stores. The role of SOCE in cardiomyocytes, however, is rather more elusive. While there is published evidence for increased Ca2+ influx into cardiomyocytes following Ca2+ store depletion, it has not been universally observed. Moreover, SOCE appears to be prominent in embryonic cardiomyocytes but declines with postnatal development. In contrast, there is overwhelming evidence that the molecular components of SOCE (e.g., STIM, Orai, and TRPC proteins) are expressed in cardiomyocytes from embryo to adult. Moreover, these proteins have been shown to contribute to disease conditions such as pathological hypertrophy, and reducing their expression can attenuate hypertrophic growth. It is plausible that SOCE might underlie Ca2+ influx into cardiomyocytes and may have important signaling functions perhaps by activating local Ca2+-sensitive processes. However, the STIM, Orai, and TRPC proteins appear to cooperate with multiple protein partners in signaling complexes. It is therefore possible that some of their signaling activities are not mediated by Ca2+ influx signals, but by protein-protein interactions.
Collapse
|
31
|
Martins TV, Evans MJ, Wysham DB, Morris RJ. Nuclear pores enable sustained perinuclear calcium oscillations. BMC SYSTEMS BIOLOGY 2016; 10:55. [PMID: 27449670 PMCID: PMC4957432 DOI: 10.1186/s12918-016-0289-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/23/2015] [Accepted: 06/14/2016] [Indexed: 11/16/2022]
Abstract
Background Calcium signalling relies on the flux of calcium ions across membranes yet how signals in different compartments are related remains unclear. In particular, similar calcium signals on both sides of the nuclear envelope have been reported and attributed to passive diffusion through nuclear pores. However, observed differing cytosolic and nucleosolic calcium signatures suggest that the signalling machinery in these compartments can act independently. Results We adapt the fire-diffuse-fire model to investigate the generation of perinuclear calcium oscillations. We demonstrate that autonomous spatio-temporal calcium patterns are still possible in the presence of nuclear and cytosolic coupling via nuclear pores. The presence or absence of this autonomy is dependent upon the strength of the coupling and the maximum firing rate of an individual calcium channel. In all cases, coupling through the nuclear pores enables robust signalling with respect to changes in the diffusion constant. Conclusions We show that contradictory interpretations of experimental data with respect to the autonomy of nuclear calcium oscillations can be reconciled within one model, with different observations being a consequence of varying nuclear pore permeabilities for calcium and refractory conditions of channels. Furthermore, our results provide an explanation for why calcium oscillations on both sides of the nuclear envelope may be beneficial for sustained perinuclear signaling. Electronic supplementary material The online version of this article (doi:10.1186/s12918-016-0289-9) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Teresa Vaz Martins
- Computational & Systems Biology and Crop Genetics, John Innes Centre, Norwich Research Park, Norwich, UK.
| | - Matthew J Evans
- Computational & Systems Biology and Crop Genetics, John Innes Centre, Norwich Research Park, Norwich, UK
| | - Derin B Wysham
- Mathematics Department, Wenatchee Valley College, Wenatchee, USA
| | - Richard J Morris
- Computational & Systems Biology and Crop Genetics, John Innes Centre, Norwich Research Park, Norwich, UK
| |
Collapse
|
32
|
Abstract
Calcium (Ca) is a universal second messenger involved in the regulation of various cellular processes, including electrical signaling, contraction, secretion, memory, gene transcription, and cell death. In heart, Ca governs cardiomyocyte contraction, is central in electrophysiological properties, and controls major signaling pathway implicated in gene transcription. How cardiomyocytes decode Ca signal to regulate gene expression without interfering with, or being controlled by, "contractile" Ca that floods the entire cytosol during each heartbeat is still elusive. In this review, we summarize recent findings on nuclear Ca regulation and its downstream signaling in cardiomyocytes. We will address difficulties in reliable quantification of nuclear Ca fluxes and discuss its role in the development and progression of cardiac hypertrophy and heart failure. We also point out key open questions to stimulate future work.
Collapse
|
33
|
Hohendanner F, Maxwell JT, Blatter LA. Cytosolic and nuclear calcium signaling in atrial myocytes: IP3-mediated calcium release and the role of mitochondria. Channels (Austin) 2016; 9:129-38. [PMID: 25891132 DOI: 10.1080/19336950.2015.1040966] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
In rabbit atrial myocytes Ca signaling has unique features due to the lack of transverse (t) tubules, the spatial arrangement of mitochondria and the contribution of inositol-1,4,5-trisphosphate (IP3) receptor-induced Ca release (IICR). During excitation-contraction coupling action potential-induced elevation of cytosolic [Ca] originates in the cell periphery from Ca released from the junctional sarcoplasmic reticulum (j-SR) and then propagates by Ca-induced Ca release from non-junctional (nj-) SR toward the cell center. The subsarcolemmal region between j-SR and the first array of nj-SR Ca release sites is devoid of mitochondria which results in a rapid propagation of activation through this domain, whereas the subsequent propagation through the nj-SR network occurs at a velocity typical for a propagating Ca wave. Inhibition of mitochondrial Ca uptake with the Ca uniporter blocker Ru360 accelerates propagation and increases the amplitude of Ca transients (CaTs) originating from nj-SR. Elevation of cytosolic IP3 levels by rapid photolysis of caged IP3 has profound effects on the magnitude of subcellular CaTs with increased Ca release from nj-SR and enhanced CaTs in the nuclear compartment. IP3 uncaging restricted to the nucleus elicites 'mini'-Ca waves that remain confined to this compartment. Elementary IICR events (Ca puffs) preferentially originate in the nucleus in close physical association with membrane structures of the nuclear envelope and the nucleoplasmic reticulum. The data suggest that in atrial myocytes the nucleus is an autonomous Ca signaling domain where Ca dynamics are primarily governed by IICR.
Collapse
Key Words
- 2-APB, 2-aminoethoxydiphenyl borate
- AP, action potential
- CICR, Ca-induced Ca release
- CRU, Ca release units
- CT, central
- CaT, Ca transient
- ECC, excitation-contraction coupling
- IICR
- IICR, IP3R-induced Ca release
- IP3
- IP3R, Inositol-1,4,5-trisphosphate receptor
- LCC, L-type Ca channels
- MCU, mitochondrial Ca uniporter
- NE, nuclear envelope
- NFAT, nuclear factor of activated T cells
- NPR, nucleoplasmic reticulum
- RyR, ryanodine receptor
- SR, sarcoplasmic reticulum
- SS, subsarcolemmal
- TF50, time to half-maximal amplitude
- TZ, transition zone.
- [Ca]i, cytosolic Ca concentration
- [Ca]mito, mitochondrial Ca concentration
- atria
- excitation-contraction coupling
- j-SR, junctional SR
- mitochondria
- nj-SR, non-junctional SR
- nuclear calcium
- t-tubule, transverse tubule
Collapse
Affiliation(s)
- Felix Hohendanner
- a Department of Molecular Biophysics and Physiology ; Rush University Medical Center ; Chicago , IL USA
| | | | | |
Collapse
|
34
|
Hulikova A, Swietach P. Nuclear proton dynamics and interactions with calcium signaling. J Mol Cell Cardiol 2015; 96:26-37. [PMID: 26183898 PMCID: PMC4915819 DOI: 10.1016/j.yjmcc.2015.07.003] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/24/2015] [Revised: 06/02/2015] [Accepted: 07/07/2015] [Indexed: 01/14/2023]
Abstract
Biochemical signals acting on the nucleus can regulate gene expression. Despite the inherent affinity of nucleic acids and nuclear proteins (e.g. transcription factors) for protons, little is known about the mechanisms that regulate nuclear pH (pHnuc), and how these could be exploited to control gene expression. Here, we show that pHnuc dynamics can be imaged using the DNA-binding dye Hoechst 33342. Nuclear pores allow the passage of medium-sized molecules (calcein), but protons must first bind to mobile buffers in order to gain access to the nucleoplasm. Fixed buffering residing in the nucleus of permeabilized cells was estimated to be very weak on the basis of the large amplitude of pHnuc transients evoked by photolytic H+-uncaging or exposure to weak acids/bases. Consequently, the majority of nuclear pH buffering is sourced from the cytoplasm in the form of mobile buffers. Effective proton diffusion was faster in nucleoplasm than in cytoplasm, in agreement with the higher mobile-to-fixed buffering ratio in the nucleus. Cardiac myocyte pHnuc changed in response to maneuvers that alter nuclear Ca2 + signals. Blocking Ca2 + release from inositol-1,4,5-trisphosphate receptors stably alkalinized the nucleus. This Ca2 +-pH interaction may arise from competitive binding to common chemical moieties. Competitive binding to mobile buffers may couple the efflux of Ca2 +via nuclear pores with a counterflux of protons. This would generate a stable pH gradient between cytoplasm and nucleus that is sensitive to the state of nuclear Ca2 + signaling. The unusual behavior of protons in the nucleus provides new mechanisms for regulating cardiac nuclear biology. Facilitated diffusion aboard mobile buffers is the only means by which protons enter the nucleus. The relative scarcity of fixed buffers residing in the nucleus accelerates proton diffusivity. Nuclear Ca2 + signals can regulate nuclear pH and generate stable gradients relative to cytoplasm.
Collapse
Affiliation(s)
- Alzbeta Hulikova
- Burdon Sanderson Cardiac Science Centre, Department of Physiology, Anatomy and Genetics, Parks Road, Oxford OX1 3PT, United Kingdom
| | - Pawel Swietach
- Burdon Sanderson Cardiac Science Centre, Department of Physiology, Anatomy and Genetics, Parks Road, Oxford OX1 3PT, United Kingdom.
| |
Collapse
|
35
|
Camoretti-Mercado B, Pauer SH, Yong HM, Smith DC, Deshpande DA, An SS, Liggett SB. Pleiotropic Effects of Bitter Taste Receptors on [Ca2+]i Mobilization, Hyperpolarization, and Relaxation of Human Airway Smooth Muscle Cells. PLoS One 2015; 10:e0131582. [PMID: 26121686 PMCID: PMC4485472 DOI: 10.1371/journal.pone.0131582] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2015] [Accepted: 06/03/2015] [Indexed: 01/25/2023] Open
Abstract
Asthma is characterized by airway inflammation and airflow obstruction from human airway smooth muscle (HASM) constriction due to increased local bronchoconstrictive substances. We have recently found bitter taste receptors (TAS2Rs) on HASM, which increase [Ca2+]i and relax the muscle. We report here that some, but not all, TAS2R agonists decrease [Ca2+]i and relax HASM contracted by G-protein coupled receptors (GPCRs) that stimulate [Ca2+]i. This suggests both a second pathway by which TAS2Rs relax, and, a heterogeneity of the response phenotype. We utilized eight TAS2R agonists and five procontractile GPCR agonists in cultured HASM cells. We find that heterogeneity in the inhibitory response hinges on which procontractile GPCR is activated. For example, chloroquine inhibits [Ca2+]i increases from histamine, but failed to inhibit [Ca2+]i increases from endothelin-1. Conversely, aristolochic acid inhibited [Ca2+]i increases from endothelin-1 but not histamine. Other dichotomous responses were found when [Ca2+]i was stimulated by bradykinin, angiotensin, and acetylcholine. There was no association between [Ca2+]i inhibition and TAS2R subtype, nor whether [Ca2+]i was increased by Gq- or Gi-coupled GPCRs. Selected studies revealed a correlation between [Ca2+]i inhibition and HASM cell-membrane hyperpolarization. To demonstrate physiologic correlates, ferromagnetic beads were attached to HASM cells and cell stiffness measured by magnetic twisting cytometry. Consistent with the [Ca2+]i inhibition results, chloroquine abolished the cell stiffening response (contraction) evoked by histamine but not by endothelin-1, while aristolochic acid inhibited cell stiffening from endothelin-1, but not from histamine. In studies using intact human bronchi, these same differential responses were found. Those TAS2R agonists that decreased [Ca2+]i, promoted hyperpolarization, and decreased HASM stiffness, caused relaxation of human airways. Thus TAS2Rs relax HASM in two ways: a low-efficiency de novo [Ca2+]i stimulation, and, a high-efficiency inhibition of GPCR-stimulated [Ca2+]i. Furthermore, there is an interaction between TAS2Rs and some GPCRs that facilitates this [Ca2+]i inhibition limb.
Collapse
Affiliation(s)
- Blanca Camoretti-Mercado
- Department of Medicine and the Center for Personalized Medicine and Genomics, University of South Florida Morsani College of Medicine, Tampa, FL, United States of America
| | - Susan H. Pauer
- Department of Medicine and the Center for Personalized Medicine and Genomics, University of South Florida Morsani College of Medicine, Tampa, FL, United States of America
| | - Hwan Mee Yong
- Department of Environmental Health Sciences, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, United States of America
| | - Dan’elle C. Smith
- Department of Medicine and the Center for Personalized Medicine and Genomics, University of South Florida Morsani College of Medicine, Tampa, FL, United States of America
| | - Deepak A. Deshpande
- Department of Medicine and Center for Translational Medicine, Thomas Jefferson University, Philadelphia, PA, United States of America
| | - Steven S. An
- Department of Environmental Health Sciences, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, United States of America
| | - Stephen B. Liggett
- Department of Medicine and the Center for Personalized Medicine and Genomics, University of South Florida Morsani College of Medicine, Tampa, FL, United States of America
- Department of Molecular Pharmacology and Physiology, University of South Florida Morsani College of Medicine, Tampa, FL, United States of America
- * E-mail:
| |
Collapse
|
36
|
Stimers JR, Song L, Rusch NJ, Rhee SW. Overexpression of the Large-Conductance, Ca2+-Activated K+ (BK) Channel Shortens Action Potential Duration in HL-1 Cardiomyocytes. PLoS One 2015; 10:e0130588. [PMID: 26091273 PMCID: PMC4474436 DOI: 10.1371/journal.pone.0130588] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2014] [Accepted: 05/22/2015] [Indexed: 12/29/2022] Open
Abstract
Long QT syndrome is characterized by a prolongation of the interval between the Q wave and the T wave on the electrocardiogram. This abnormality reflects a prolongation of the ventricular action potential caused by a number of genetic mutations or a variety of drugs. Since effective treatments are unavailable, we explored the possibility of using cardiac expression of the large-conductance, Ca2+-activated K+ (BK) channel to shorten action potential duration (APD). We hypothesized that expression of the pore-forming α subunit of human BK channels (hBKα) in HL-1 cells would shorten action potential duration in this mouse atrial cell line. Expression of hBKα had minimal effects on expression levels of other ion channels with the exception of a small but significant reduction in Kv11.1. Patch-clamped hBKα expressing HL-1 cells exhibited an outward voltage- and Ca2+-sensitive K+ current, which was inhibited by the BK channel blocker iberiotoxin (100 nM). This BK current phenotype was not detected in untransfected HL-1 cells or in HL-1 null cells sham-transfected with an empty vector. Importantly, APD in hBKα-expressing HL-1 cells averaged 14.3 ± 2.8 ms (n = 10), which represented a 53% reduction in APD compared to HL-1 null cells lacking BKα expression. APD in the latter cells averaged 31.0 ± 5.1 ms (n = 13). The shortened APD in hBKα-expressing cells was restored to normal duration by 100 nM iberiotoxin, suggesting that a repolarizing K+ current attributed to BK channels accounted for action potential shortening. These findings provide initial proof-of-concept that the introduction of hBKα channels into a cardiac cell line can shorten APD, and raise the possibility that gene-based interventions to increase hBKα channels in cardiac cells may hold promise as a therapeutic strategy for long QT syndrome.
Collapse
Affiliation(s)
- Joseph R. Stimers
- Department of Pharmacology & Toxicology, University of Arkansas for Medical Sciences, Little Rock, Arkansas, United States of America
- * E-mail:
| | - Li Song
- Department of Pharmacology & Toxicology, University of Arkansas for Medical Sciences, Little Rock, Arkansas, United States of America
| | - Nancy J. Rusch
- Department of Pharmacology & Toxicology, University of Arkansas for Medical Sciences, Little Rock, Arkansas, United States of America
| | - Sung W. Rhee
- Department of Pharmacology & Toxicology, University of Arkansas for Medical Sciences, Little Rock, Arkansas, United States of America
| |
Collapse
|
37
|
Louch WE, Koivumäki JT, Tavi P. Calcium signalling in developing cardiomyocytes: implications for model systems and disease. J Physiol 2015; 593:1047-63. [PMID: 25641733 PMCID: PMC4358669 DOI: 10.1113/jphysiol.2014.274712] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2014] [Accepted: 12/28/2014] [Indexed: 12/15/2022] Open
Abstract
Adult cardiomyocytes exhibit complex Ca(2+) homeostasis, enabling tight control of contraction and relaxation. This intricate regulatory system develops gradually, with progressive maturation of specialized structures and increasing capacity of Ca(2+) sources and sinks. In this review, we outline current understanding of these developmental processes, and draw parallels to pathophysiological conditions where cardiomyocytes exhibit a striking regression to an immature state of Ca(2+) homeostasis. We further highlight the importance of understanding developmental physiology when employing immature cardiomyocyte models such as cultured neonatal cells and stem cells.
Collapse
Affiliation(s)
- William E Louch
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo0424, Oslo, Norway
- K. G. Jebsen Cardiac Research Center and Center for Heart Failure Research, University of Oslo0316, Oslo, Norway
| | - Jussi T Koivumäki
- Simula Research Laboratory, Center for Cardiological Innovation and Center for Biomedical ComputingOslo, Norway
| | - Pasi Tavi
- Department of Biotechnology and Molecular Medicine, A.I. Virtanen Institute for Molecular Sciences, University of Eastern FinlandKuopio, Finland
| |
Collapse
|
38
|
Hammer KP, Hohendanner F, Blatter LA, Pieske BM, Heinzel FR. Variations in local calcium signaling in adjacent cardiac myocytes of the intact mouse heart detected with two-dimensional confocal microscopy. Front Physiol 2015; 5:517. [PMID: 25628569 PMCID: PMC4290493 DOI: 10.3389/fphys.2014.00517] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2014] [Accepted: 12/18/2014] [Indexed: 11/13/2022] Open
Abstract
Dyssynchronous local Ca release within individual cardiac myocytes has been linked to cellular contractile dysfunction. Differences in Ca kinetics in adjacent cells may also provide a substrate for inefficient contraction and arrhythmias. In a new approach we quantify variation in local Ca transients between adjacent myocytes in the whole heart. Langendorff-perfused mouse hearts were loaded with Fluo-8 AM to detect Ca and Di-4-ANEPPS to visualize cell membranes. A spinning disc confocal microscope with a fast camera allowed us to record Ca signals within an area of 465 μm by 315 μm with an acquisition speed of 55 fps. Images from multiple transients recorded at steady state were registered to their time point in the cardiac cycle to restore averaged local Ca transients with a higher temporal resolution. Local Ca transients within and between adjacent myocytes were compared with regard to amplitude, time to peak and decay at steady state stimulation (250 ms cycle length). Image registration from multiple sequential Ca transients allowed reconstruction of high temporal resolution (2.4 ± 1.3 ms) local CaT in 2D image sets (N = 4 hearts, n = 8 regions). During steady state stimulation, spatial Ca gradients were homogeneous within cells in both directions and independent of distance between measured points. Variation in CaT amplitudes was similar across the short and the long side of neighboring cells. Variations in TAU and TTP were similar in both directions. Isoproterenol enhanced the CaT but not the overall pattern of spatial heterogeneities. Here we detected and analyzed local Ca signals in intact mouse hearts with high temporal and spatial resolution, taking into account 2D arrangement of the cells. We observed significant differences in the variation of CaT amplitude along the long and short axis of cardiac myocytes. Variations of Ca signals between neighboring cells may contribute to the substrate of cardiac remodeling.
Collapse
Affiliation(s)
- Karin P Hammer
- Department of Cardiology, Medical University of Graz Graz, Austria ; Department of Internal Medicine II, University Hospital Regensburg Regensburg, Germany
| | - Felix Hohendanner
- Molecular Biophysics and Physiology, Rush Medical College, Rush University Chicago, IL, USA
| | - Lothar A Blatter
- Molecular Biophysics and Physiology, Rush Medical College, Rush University Chicago, IL, USA
| | - Burkert M Pieske
- Department of Cardiology, Medical University of Graz Graz, Austria ; Department of Cardiology, Charité-Universitaetsmedizin Berlin Berlin, Germany
| | - Frank R Heinzel
- Department of Cardiology, Medical University of Graz Graz, Austria ; Department of Cardiology, Charité-Universitaetsmedizin Berlin Berlin, Germany
| |
Collapse
|
39
|
Grandi E, Edwards AG, Herren AW, Bers DM. CaMKII comes of age in cardiac health and disease. Front Pharmacol 2014; 5:154. [PMID: 25071573 PMCID: PMC4080132 DOI: 10.3389/fphar.2014.00154] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2014] [Accepted: 06/12/2014] [Indexed: 11/13/2022] Open
Affiliation(s)
- Eleonora Grandi
- Department of Pharmacology, University of California, Davis Davis, CA, USA
| | - Andrew G Edwards
- Institute for Experimental Medicine, Oslo University Hospital Ullevål Oslo, Norway ; Simula Research Laboratory Lysaker, Norway
| | - Anthony W Herren
- Department of Pharmacology, University of California, Davis Davis, CA, USA
| | - Donald M Bers
- Department of Pharmacology, University of California, Davis Davis, CA, USA
| |
Collapse
|