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Benzoni P, Gazzerro E, Fiorillo C, Baratto S, Bartolucci C, Severi S, Milanesi R, Lippi M, Langione M, Murano C, Meoni C, Popolizio V, Cospito A, Baruscotti M, Bucchi A, Barbuti A. Caveolin-3 and Caveolin-1 Interaction Decreases Channel Dysfunction Due to Caveolin-3 Mutations. Int J Mol Sci 2024; 25:980. [PMID: 38256054 PMCID: PMC10816214 DOI: 10.3390/ijms25020980] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2023] [Revised: 12/15/2023] [Accepted: 01/03/2024] [Indexed: 01/24/2024] Open
Abstract
Caveolae constitute membrane microdomains where receptors and ion channels functionally interact. Caveolin-3 (cav-3) is the key structural component of muscular caveolae. Mutations in CAV3 lead to caveolinopathies, which result in both muscular dystrophies and cardiac diseases. In cardiomyocytes, cav-1 participates with cav-3 to form caveolae; skeletal myotubes and adult skeletal fibers do not express cav-1. In the heart, the absence of cardiac alterations in the majority of cases may depend on a conserved organization of caveolae thanks to the expression of cav-1. We decided to focus on three specific cav-3 mutations (Δ62-64YTT; T78K and W101C) found in heterozygosis in patients suffering from skeletal muscle disorders. We overexpressed both the WT and mutated cav-3 together with ion channels interacting with and modulated by cav-3. Patch-clamp analysis conducted in caveolin-free cells (MEF-KO), revealed that the T78K mutant is dominant negative, causing its intracellular retention together with cav-3 WT, and inducing a significant reduction in current densities of all three ion channels tested. The other cav-3 mutations did not cause significant alterations. Mathematical modelling of the effects of cav-3 T78K would impair repolarization to levels incompatible with life. For this reason, we decided to compare the effects of this mutation in other cell lines that endogenously express cav-1 (MEF-STO and CHO cells) and to modulate cav-1 expression with an shRNA approach. In these systems, the membrane localization of cav-3 T78K was rescued in the presence of cav-1, and the current densities of hHCN4, hKv1.5 and hKir2.1 were also rescued. These results constitute the first evidence of a compensatory role of cav-1 in the heart, justifying the reduced susceptibility of this organ to caveolinopathies.
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Affiliation(s)
- Patrizia Benzoni
- The Cell Physiology MiLab, Department of Biosciences, Università degli Studi di Milano, 20133 Milan, Italy
| | - Elisabetta Gazzerro
- Unit of Muscle Research, Experimental and Clinical Research Center, Cooperation between the Max-Delbrück-Center for Molecular Medicine in the Helmholtz Association and Charité-University Berlin, 13125 Berlin, Germany
| | - Chiara Fiorillo
- Child Neuropsychiatry Unit, IRCCS Istituto Giannina Gaslini, DINOGMI-University of Genova, 16147 Genova, Italy
| | - Serena Baratto
- Center of Translational and Experimental Myology, IRCCS Istituto Giannina Gaslini, 16147 Genova, Italy
| | - Chiara Bartolucci
- Department of Electrical, Electronic and Information Engineering “Guglielmo Marconi”, University of Bologna, 47521 Cesena, Italy
| | - Stefano Severi
- Department of Electrical, Electronic and Information Engineering “Guglielmo Marconi”, University of Bologna, 47521 Cesena, Italy
| | - Raffaella Milanesi
- The Cell Physiology MiLab, Department of Biosciences, Università degli Studi di Milano, 20133 Milan, Italy
| | - Melania Lippi
- The Cell Physiology MiLab, Department of Biosciences, Università degli Studi di Milano, 20133 Milan, Italy
| | - Marianna Langione
- The Cell Physiology MiLab, Department of Biosciences, Università degli Studi di Milano, 20133 Milan, Italy
| | - Carmen Murano
- The Cell Physiology MiLab, Department of Biosciences, Università degli Studi di Milano, 20133 Milan, Italy
| | - Clarissa Meoni
- The Cell Physiology MiLab, Department of Biosciences, Università degli Studi di Milano, 20133 Milan, Italy
| | - Vera Popolizio
- The Cell Physiology MiLab, Department of Biosciences, Università degli Studi di Milano, 20133 Milan, Italy
| | - Alessandro Cospito
- The Cell Physiology MiLab, Department of Biosciences, Università degli Studi di Milano, 20133 Milan, Italy
| | - Mirko Baruscotti
- The Cell Physiology MiLab, Department of Biosciences, Università degli Studi di Milano, 20133 Milan, Italy
| | - Annalisa Bucchi
- The Cell Physiology MiLab, Department of Biosciences, Università degli Studi di Milano, 20133 Milan, Italy
| | - Andrea Barbuti
- The Cell Physiology MiLab, Department of Biosciences, Università degli Studi di Milano, 20133 Milan, Italy
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Benzoni P, Da Dalt L, Elia N, Popolizio V, Cospito A, Giannetti F, Dell’Era P, Olesen MS, Bucchi A, Baruscotti M, Norata GD, Barbuti A. PITX2 gain-of-function mutation associated with atrial fibrillation alters mitochondrial activity in human iPSC atrial-like cardiomyocytes. Front Physiol 2023; 14:1250951. [PMID: 38028792 PMCID: PMC10679737 DOI: 10.3389/fphys.2023.1250951] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Accepted: 10/20/2023] [Indexed: 12/01/2023] Open
Abstract
Atrial fibrillation (AF) is the most common cardiac arrhythmia worldwide; however, the underlying causes of AF initiation are still poorly understood, particularly because currently available models do not allow in distinguishing the initial causes from maladaptive remodeling that induces and perpetuates AF. Lately, the genetic background has been proven to be important in the AF onset. iPSC-derived cardiomyocytes, being patient- and mutation-specific, may help solve this diatribe by showing the initial cell-autonomous changes underlying the development of the disease. Transcription factor paired-like homeodomain 2 (PITX2) has been identified as a key regulator of atrial development/differentiation, and the PITX2 genomic locus has the highest association with paroxysmal AF. PITX2 influences mitochondrial activity, and alterations in either its expression or function have been widely associated with AF. In this work, we investigate the activity of mitochondria in iPSC-derived atrial cardiomyocytes (aCMs) obtained from a young patient (24 years old) with paroxysmal AF, carrying a gain-of-function mutation in PITX2 (rs138163892) and from its isogenic control (CTRL) in which the heterozygous point mutation has been reverted to WT. PITX2 aCMs show a higher mitochondrial content, increased mitochondrial activity, and superoxide production under basal conditions when compared to CTRL aCMs. However, increasing mitochondrial workload by FCCP or β-adrenergic stimulation allows us to unmask mitochondrial defects in PITX2 aCMs, which are incapable of responding efficiently to the higher energy demand, determining ATP deficiency.
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Affiliation(s)
- Patrizia Benzoni
- The Cell Physiology MiLab, Department Biosciences, Università degli Studi di Milano, Milano, Italy
| | - Lorenzo Da Dalt
- Department of Pharmacological and Biomolecular Sciences, Università degli Studi di Milano, Milano, Italy
| | - Noemi Elia
- The Cell Physiology MiLab, Department Biosciences, Università degli Studi di Milano, Milano, Italy
- Cell Factory, Fondazione IRCCS Ca’Granda Ospedale Maggiore Policlinico, Milano, Italy
| | - Vera Popolizio
- The Cell Physiology MiLab, Department Biosciences, Università degli Studi di Milano, Milano, Italy
| | - Alessandro Cospito
- The Cell Physiology MiLab, Department Biosciences, Università degli Studi di Milano, Milano, Italy
| | - Federica Giannetti
- The Cell Physiology MiLab, Department Biosciences, Università degli Studi di Milano, Milano, Italy
- Center for Cardiac Arrhythmias of Genetic Origin and Laboratory of Cardiovascular Genetics, Istituto Auxologico Italiano IRCCS, Milano, Italy
| | - Patrizia Dell’Era
- Department of Molecular and Translational Medicine, Università degli Studi di Brescia, Brescia, Italy
| | - Morten S. Olesen
- The Heart Centre, Rigshospitalet, Laboratory for Molecular Cardiology, Department of Cardiology, University Hospital of Copenhagen, Copenhagen, Denmark
| | - Annalisa Bucchi
- The Cell Physiology MiLab, Department Biosciences, Università degli Studi di Milano, Milano, Italy
| | - Mirko Baruscotti
- The Cell Physiology MiLab, Department Biosciences, Università degli Studi di Milano, Milano, Italy
| | - Giuseppe Danilo Norata
- Department of Pharmacological and Biomolecular Sciences, Università degli Studi di Milano, Milano, Italy
| | - Andrea Barbuti
- The Cell Physiology MiLab, Department Biosciences, Università degli Studi di Milano, Milano, Italy
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Landi S, Giannetti F, Benzoni P, Campostrini G, Rossi G, Piantoni C, Bertoli G, Bonfanti C, Carnevali L, Bucchi A, Baruscotti M, Careccia G, Messina G, Barbuti A. Lack of the transcription factor Nfix causes tachycardia in mice sinus node and rats neonatal cardiomyocytes. Acta Physiol (Oxf) 2023; 239:e13981. [PMID: 37186371 DOI: 10.1111/apha.13981] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2023] [Revised: 04/20/2023] [Accepted: 04/23/2023] [Indexed: 05/17/2023]
Abstract
AIMS Nfix is a transcription factor belonging to the Nuclear Factor I (NFI) family comprising four members (Nfia, b, c, x). Nfix plays important roles in the development and function of several organs. In muscle development, Nfix controls the switch from embryonic to fetal myogenesis by promoting fast twitching fibres. In the adult muscle, following injury, lack of Nfix impairs regeneration, inducing higher content of slow-twitching fibres. Nfix is expressed also in the heart, but its function has been never investigated before. We studied Nfix role in this organ. METHODS Using Nfix-null and wild type (WT) mice we analyzed: (1) the expression pattern of Nfix during development by qPCR and (2) the functional alterations caused by its absence, by in vivo telemetry and in vitro patch clamp analysis. RESULTS AND CONCLUSIONS Nfix expression start in the heart from E12.5. Adult hearts of Nfix-null mice show a hearts morphology and sarcomeric proteins expression similar to WT. However, Nfix-null animals show tachycardia that derives form an intrinsic higher beating rate of the sinus node (SAN). Molecular and functional analysis revealed that sinoatrial cells of Nfix-null mice express a significantly larger L-type calcium current (Cacna1d + Cacna1c). Interestingly, downregulation of Nfix by sh-RNA in primary cultures of neonatal rat ventricular cardiomyocytes induced a similar increase in their spontaneous beating rate and in ICaL current. In conclusion, our data provide the first demonstration of a role of Nfix that, increasing the L-type calcium current, modulates heart rate.
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Affiliation(s)
- Sara Landi
- The Cell Physiology MiLab, Department of Biosciences, Università degli Studi di Milano, Milan, Italy
| | - Federica Giannetti
- The Cell Physiology MiLab, Department of Biosciences, Università degli Studi di Milano, Milan, Italy
| | - Patrizia Benzoni
- The Cell Physiology MiLab, Department of Biosciences, Università degli Studi di Milano, Milan, Italy
| | - Giulia Campostrini
- The Cell Physiology MiLab, Department of Biosciences, Università degli Studi di Milano, Milan, Italy
| | - Giuliana Rossi
- Department of Biosciences, Università degli Studi di Milano, Milan, Italy
| | - Chiara Piantoni
- The Cell Physiology MiLab, Department of Biosciences, Università degli Studi di Milano, Milan, Italy
| | - Giorgia Bertoli
- The Cell Physiology MiLab, Department of Biosciences, Università degli Studi di Milano, Milan, Italy
| | - Chiara Bonfanti
- Department of Biosciences, Università degli Studi di Milano, Milan, Italy
| | - Luca Carnevali
- The Cell Physiology MiLab, Department of Biosciences, Università degli Studi di Milano, Milan, Italy
| | - Annalisa Bucchi
- The Cell Physiology MiLab, Department of Biosciences, Università degli Studi di Milano, Milan, Italy
| | - Mirko Baruscotti
- The Cell Physiology MiLab, Department of Biosciences, Università degli Studi di Milano, Milan, Italy
| | - Giorgia Careccia
- Department of Biosciences, Università degli Studi di Milano, Milan, Italy
| | - Graziella Messina
- Department of Biosciences, Università degli Studi di Milano, Milan, Italy
| | - Andrea Barbuti
- The Cell Physiology MiLab, Department of Biosciences, Università degli Studi di Milano, Milan, Italy
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Marchionni G, Levi S, Pontara A, Santambrogio P, Prat VD, Bucchi A, Maria Ferreri AJ, Zambetti M, Foppoli M, Gianni L, Ciceri F, Margonato A, Fragasso G. 780 POTENTIAL RELATIONSHIP BETWEEN MITOCHONDRIAL FERRITIN EXPRESSION AND CARDIOTOXICITY IN PATIENTS UNDERGOING ANTHRACYLINE CHEMOTHERAPY. Eur Heart J Suppl 2022. [DOI: 10.1093/eurheartjsupp/suac121.124] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Abstract
Background
Anthracyclines effectiveness is burdened by numerous side effects, among which cardiotoxicity (CTX) is the one carrying the highest impact on survival. Prevention of CTX is known to be far more effective than its treatment. Nonetheless, present patients stratification does not predict different post-treatment outcomes. The inter-individual variability in the response to treatment likely resides at the molecular level. In this context, mitochondrial ferritin (FtMt) has been studied in preclinical models of doxorubicin-induced cardiotoxicity. Both in cell lines and animal models, overexpression of this protein has been found to be protective against the cytotoxic oxidative damage deriving from anthracycline use.
Aim of the study
The primary aim of the study was to evaluate – for the first time in humans and in mouse myocardial cells lines – the expression of FtMt and its relationship with the potential development of cardiotoxicity in patients undergoing chemotherapy with anthracyclines.
Methods
Twenty-nine patients referred to our Oncology Outpatient Clinic to start treatment with anthracyclines – for either lymphoma or breast cancer – were enrolled before treatment initiation. All patients were above 18 years of age and free from any cardiovascular pathology at baseline. Troponin T (TnT), Brain Natriuretic Peptide (NT-proBNP), FtMt and creatinine were evaluated at baseline, before any chemotherapy cycle, at the end of the protocol, at 6 and 12 months from the first cycle. TnT and NT-proBNP were quantified through ECLIA and the expression of FtMt through qRT-PCR performed on peripheral white blood cells. Left ventricular function was evaluated through standard echocardiography at baseline, at the end of chemotherapy, at 6 and 12 months. Furthermore, variations in FtMt expression in response to doxorubicin treatment were studied on mouse primary cardiomyocytes.
Results
Direct evaluation of FtMt expression in mouse myocardial cells showed higher levels of FtMt in cardiomyocytes exposed to doxorubicin (p=0.0239). In the clinical model FtMt expression was found to be decreased after treatment initiation, with a trend that in the descriptive analysis appeared to be opposite to the one registered for TnT. For any unit of FtMt at baseline, single TnT values after treatment and at one year were found to be decreased of 1,89 ng/L and of 1,57 ng/L, respectively. TnT was the only cardiac parameter showing significant variation following anthracycline administration, with an average increase of 10 ng/L (p<0,0001) and 15,8 ng/L (p=0,0071) in breast cancer and lymphoma patients respectively and remained elevated at follow-up only in the lymphoma group with a difference of 11,35ng/L at 1 year (p=0,0017). No occurrence of CTX – defined according to international guidelines - was found in the population under study.
Conclusions
Our results confirm that exposure to anthracyclines influences FtMt expression. The study performed on mouse primary cardiomyocytes demonstrate for the first time the ability of cardiac myocytes to increase FtMt expression in response to doxorubicin. In the clinical model any additional unit of FtMt at baseline was associated with a reduction in TnT values at the end of the treatment and at 1 year, potentially indicating a protective role of this protein in this context. The lack of frank cardiotoxicity in this group impeded the evaluation of the prognostic meaning of this event. In the future drugs able to upregulate the expression of this protein should be investigated as potential strategy to prevent anthracycline-induced cardiotoxicity.
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Affiliation(s)
| | - Sonia Levi
- Unità Di Ricerca Proteomica Del Metabolismo Del Ferro - Università Vita-Salute San Raffaele
| | - Andrea Pontara
- Dipartimento Di Medicina Interna - Ospedale San Raffaele
| | - Paolo Santambrogio
- Unità Di Ricerca Proteomica Del Metabolismo Del Ferro - Università Vita-Salute San Raffaele
| | | | - Annalisa Bucchi
- Centro Interuniversitario Di Medicina Molecolare E Biofisica Applicata - Università Degli Studi Di Milano
| | | | - Milva Zambetti
- Dipartimento Di Oncologia Clinica - Ospedale San Raffaele
| | - Marco Foppoli
- Unità Di Medicina Onco-Ematologica - Ospedale San Raffaele
| | - Luca Gianni
- Dipartimento Di Oncologia Clinica - Ospedale San Raffaele
| | - Fabio Ciceri
- Unità Tumori Linfoidi - Ospedale San Raffaele Milano
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Piantoni C, Paina M, Molla D, Liu S, Bertoli G, Jiang H, Wang Y, Wang Y, Wang Y, DiFrancesco D, Barbuti A, Bucchi A, Baruscotti M. Chinese natural compound decreases pacemaking of rabbit cardiac sinoatrial cells by targeting second messenger regulation of f-channels. eLife 2022; 11:75119. [PMID: 35315774 PMCID: PMC8940175 DOI: 10.7554/elife.75119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Accepted: 03/03/2022] [Indexed: 11/13/2022] Open
Abstract
Tongmai Yangxin (TMYX) is a complex compound of the Traditional Chinese Medicine (TCM) used to treat several cardiac rhythm disorders; however, no information regarding its mechanism of action is available. In this study we provide a detailed characterization of the effects of TMYX on the electrical activity of pacemaker cells and unravel its mechanism of action. Single-cell electrophysiology revealed that TMYX elicits a reversible and dose-dependent (2/6 mg/ml) slowing of spontaneous action potentials rate (−20.8/–50.2%) by a selective reduction of the diastolic phase (−50.1/–76.0%). This action is mediated by a negative shift of the If activation curve (−6.7/–11.9 mV) and is caused by a reduction of the cyclic adenosine monophosphate (cAMP)-induced stimulation of pacemaker channels. We provide evidence that TMYX acts by directly antagonizing the cAMP-induced allosteric modulation of the pacemaker channels. Noticeably, this mechanism functionally resembles the pharmacological actions of muscarinic stimulation or β-blockers, but it does not require generalized changes in cytoplasmic cAMP levels thus ensuring a selective action on rate. In agreement with a competitive inhibition mechanism, TMYX exerts its maximal antagonistic action at submaximal cAMP concentrations and then progressively becomes less effective thus ensuring a full contribution of If to pacemaker rate during high metabolic demand and sympathetic stimulation.
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Affiliation(s)
- Chiara Piantoni
- Department of Biosciences, The Cell Physiology Lab and "Centro Interuniversitario di Medicina Molecolare e Biofisica Applicata", Università degli Studi di Milano, Milano, Italy
| | - Manuel Paina
- Department of Biosciences, The Cell Physiology Lab and "Centro Interuniversitario di Medicina Molecolare e Biofisica Applicata", Università degli Studi di Milano, Milano, Italy
| | - David Molla
- Department of Biosciences, The Cell Physiology Lab and "Centro Interuniversitario di Medicina Molecolare e Biofisica Applicata", Università degli Studi di Milano, Milano, Italy
| | - Sheng Liu
- Department of Physiology and Pathophysiology, School of Basic Medical Science, Tianjin Medical University, Tianjin, China
| | - Giorgia Bertoli
- Department of Biosciences, The Cell Physiology Lab and "Centro Interuniversitario di Medicina Molecolare e Biofisica Applicata", Università degli Studi di Milano, Milano, Italy
| | - Hongmei Jiang
- Department of Physiology and Pathophysiology, School of Basic Medical Science, Tianjin Medical University, Tianjin, China
| | - Yanyan Wang
- School of Integrative Medicine, Tianjin University of Traditional Chinese Medicine, Tianjin, China
| | - Yi Wang
- College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China
| | - Yi Wang
- Institute of Traditional Chinese Medicine Tianjin University of Traditional Chinese Medicine, Tianjin, China
| | - Dario DiFrancesco
- Department of Biosciences, The Cell Physiology Lab and "Centro Interuniversitario di Medicina Molecolare e Biofisica Applicata", Università degli Studi di Milano, Milano, Italy
| | - Andrea Barbuti
- Department of Biosciences, The Cell Physiology Lab and "Centro Interuniversitario di Medicina Molecolare e Biofisica Applicata", Università degli Studi di Milano, Milano, Italy
| | - Annalisa Bucchi
- Department of Biosciences, The Cell Physiology Lab and "Centro Interuniversitario di Medicina Molecolare e Biofisica Applicata", Università degli Studi di Milano, Milano, Italy
| | - Mirko Baruscotti
- Department of Biosciences, The Cell Physiology Lab and "Centro Interuniversitario di Medicina Molecolare e Biofisica Applicata", Università degli Studi di Milano, Milano, Italy
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Benzoni P, Bertoli G, Giannetti F, Piantoni C, Milanesi R, Pecchiari M, Barbuti A, Baruscotti M, Bucchi A. The funny current: Even funnier than 40 years ago. Uncanonical expression and roles of HCN/f channels all over the body. Prog Biophys Mol Biol 2021; 166:189-204. [PMID: 34400215 DOI: 10.1016/j.pbiomolbio.2021.08.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Revised: 06/25/2021] [Accepted: 08/09/2021] [Indexed: 12/25/2022]
Abstract
Discovered some 40 years ago, the If current has since been known as the "pacemaker" current due to its role in the initiation and modulation of the heartbeat and of neuronal excitability. But this is not all, the funny current keeps entertaining the researchers; indeed, several data discovering novel and uncanonical roles of f/HCN channel are quickly accumulating. In the present review, we provide an overview of the expression and cellular functions of HCN/f channels in a variety of systems/organs, and particularly in sour taste transduction, hormones secretion, activation of astrocytes and microglia, inhibition of osteoclastogenesis, renal ammonium excretion, and peristalsis in the gastrointestinal and urine systems. We also analyzed the role of HCN channels in sustaining cellular respiration in mitochondria and their participation to mitophagy under specific conditions. The relevance of HCN currents in undifferentiated cells, and specifically in the control of stem cell cycle and in bioelectrical signals driving left/right asymmetry during zygote development, is also considered. Finally, we present novel data concerning the expression of HCN mRNA in human leukocytes. We can thus conclude that the emerging evidence presented in this review clearly points to an increasing interest and importance of the "funny" current that goes beyond its role in cardiac sinoatrial and neuronal excitability regulation.
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Affiliation(s)
- Patrizia Benzoni
- The Cell Physiology MiLab, Department of Biosciences, Università degli Studi di Milano, Via G. Celoria 26, 20133, Milan, Italy
| | - Giorgia Bertoli
- The Cell Physiology MiLab, Department of Biosciences, Università degli Studi di Milano, Via G. Celoria 26, 20133, Milan, Italy
| | - Federica Giannetti
- The Cell Physiology MiLab, Department of Biosciences, Università degli Studi di Milano, Via G. Celoria 26, 20133, Milan, Italy
| | - Chiara Piantoni
- The Cell Physiology MiLab, Department of Biosciences, Università degli Studi di Milano, Via G. Celoria 26, 20133, Milan, Italy; Present Address: Institute of Neurophysiology, Hannover Medical School, Carl-Neuberg-Str.1, 30625, Hannover, Germany
| | - Raffaella Milanesi
- The Cell Physiology MiLab, Department of Biosciences, Università degli Studi di Milano, Via G. Celoria 26, 20133, Milan, Italy; Present Address: Dipartimento di Medicina Veterinaria, Università degli Studi di Milano, Via Dell'Università 6, 26900, Lodi, Italy
| | - Matteo Pecchiari
- Department of Pathophysiology and Transplantation, Università degli Studi di Milano, Via L. Mangiagalli 32, 20133, Milan, Italy
| | - Andrea Barbuti
- The Cell Physiology MiLab, Department of Biosciences, Università degli Studi di Milano, Via G. Celoria 26, 20133, Milan, Italy
| | - Mirko Baruscotti
- The Cell Physiology MiLab, Department of Biosciences, Università degli Studi di Milano, Via G. Celoria 26, 20133, Milan, Italy
| | - Annalisa Bucchi
- The Cell Physiology MiLab, Department of Biosciences, Università degli Studi di Milano, Via G. Celoria 26, 20133, Milan, Italy.
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Benzoni P, Giannetti F, Cospito A, Rossini A, Bucchi A, Baruscotti M, Barbuti A. When multiple caveolins make the difference: Cav1 partly compensates Cav3 alterations and rescues ion channels expression. Europace 2021. [DOI: 10.1093/europace/euab116.535] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Abstract
Funding Acknowledgements
Type of funding sources: Foundation. Main funding source(s): Fondazione Cariplo
Caveolae are small-membrane invagination that contribute both to buffering excessive contraction-dependent membrane strain and to initiation of membrane repair. Moreover, they constitute micro-domains where receptors and ion channels are clustered, favouring their functional interaction. Caveolin-3 (Cav3) is the key structural component of muscular caveolae. Mutations in Cav3 gene are associated with alterations of the skeletal muscle architecture leading to some rare forms of hereditary skeletal myopathies and/or cardiomyopathies called caveolinopathies. Notably, skeletal muscle dysfunctions usually precede cardiac dysfunctions, even though the mutated Cav3 is expressed in both cell types.
An important difference between skeletal fibers and cardiomyocytes is that in the latter, caveolin-1 (Cav1) participates with Cav3 to form caveolae; skeletal myotubes instead do not express Cav1.The delay or lack of onset of cardiac alterations in caveolinopathies may depend on a preserved micro-domains organization in the heart compared to skeletal muscle, due to Cav1 expression. We decided to focus on a specific mutation T78K found in heterozygous in a patient with Ripple muscle disease and hyperCKemia. We have characterized human cardiomyocytes (CM) differentiated from induced pluripotent stem cells (iPSC) derived from this patient and one healthy control. In particular, we have investigated which caveolin isoforms are expressed at day 30 of differentiation, finding both Cav1 and Cav3, with a significant decrease of Cav3 isoform in T78K-CM. Their different expressions significantly increase T78K membrane resistance (3.27 ± 0.6 GΩ versus 1.64 ± 0.4 GΩ in the CTRL-CM), and consequently membrane excitability. The T78K_CM showed an increase spontaneous beating rate compared to CTRL (1,75± 0,08 Hz and 0,89 ± 0,4 Hz, respectively).
Previous laboratory analysis conducted in caveolin-free MEF cells, co-transfected with WT and T78K Cav3 mutation, revealed that the T78K mutant is dominant, inducing the retention of WT Cav3 in the perinuclear areas and causes significant reduction in current density of three ion channels (HCN4, Kv1.5 and Kir2.1) known to interact with caveolins. The dominant decreased in cav3 expression is in line with previous data in skeletal muscle biopsy, however, electrophysiological data would be likely incompatible with life. For this reason, we decided to compare the impact of this mutation in CHO cells that exhibit high levels of Cav1, and in cav-1 expressing MEF line. In these systems, the membrane localization of Cav3 T78K is rescued both in heterozygous and homozygous conditions. In line with caveolin membrane expression, HCN4, Kv1.5 and Kir2.1 density is also rescued to normal levels. These results constitute the first evidence of a possible role of Cav1 in compensating membrane disorganization and disfunction due to Cav3 mutations in the heart, making this organ less susceptible to caveolinopathies.
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Affiliation(s)
- P Benzoni
- University of Milan, Bioscience, Milan, Italy
| | - F Giannetti
- University of Milan, Bioscience, Milan, Italy
| | - A Cospito
- University of Milan, Bioscience, Milan, Italy
| | - A Rossini
- European Institute EURAC , Bolzano, Italy
| | - A Bucchi
- University of Milan, Bioscience, Milan, Italy
| | | | - A Barbuti
- University of Milan, Bioscience, Milan, Italy
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8
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Piantoni C, Carnevali L, Molla D, Barbuti A, DiFrancesco D, Bucchi A, Baruscotti M. Age-Related Changes in Cardiac Autonomic Modulation and Heart Rate Variability in Mice. Front Neurosci 2021; 15:617698. [PMID: 34084126 PMCID: PMC8168539 DOI: 10.3389/fnins.2021.617698] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Accepted: 04/20/2021] [Indexed: 01/08/2023] Open
Abstract
Objective The aim of this study was to assess age-related changes in cardiac autonomic modulation and heart rate variability (HRV) and their association with spontaneous and pharmacologically induced vulnerability to cardiac arrhythmias, to verify the translational relevance of mouse models for further in-depth evaluation of the link between autonomic changes and increased arrhythmic risk with advancing age. Methods Heart rate (HR) and time- and frequency-domain indexes of HRV were calculated from Electrocardiogram (ECG) recordings in two groups of conscious mice of different ages (4 and 19 months old) (i) during daily undisturbed conditions, (ii) following peripheral β-adrenergic (atenolol), muscarinic (methylscopolamine), and β-adrenergic + muscarinic blockades, and (iii) following β-adrenergic (isoprenaline) stimulation. Vulnerability to arrhythmias was evaluated during daily undisturbed conditions and following β-adrenergic stimulation. Results HRV analysis and HR responses to autonomic blockades revealed that 19-month-old mice had a lower vagal modulation of cardiac function compared with 4-month-old mice. This age-related autonomic effect was not reflected in changes in HR, since intrinsic HR was lower in 19-month-old compared with 4-month-old mice. Both time- and frequency-domain HRV indexes were reduced following muscarinic, but not β-adrenergic blockade in younger mice, and to a lesser extent in older mice, suggesting that HRV is largely modulated by vagal tone in mice. Finally, 19-month-old mice showed a larger vulnerability to both spontaneous and isoprenaline-induced arrhythmias. Conclusion The present study combines HRV analysis and selective pharmacological autonomic blockades to document an age-related impairment in cardiac vagal modulation in mice which is consistent with the human condition. Given their short life span, mice could be further exploited as an aged model for studying the trajectory of vagal decline with advancing age using HRV measures, and the mechanisms underlying its association with proarrhythmic remodeling of the senescent heart.
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Affiliation(s)
- Chiara Piantoni
- Department of Biosciences, The PaceLab and "Centro Interuniversitario di Medicina Molecolare e Biofisica Applicata", Università degli Studi di Milano, Milan, Italy.,Institute of Neurophysiology, Hannover Medical School, Hanover, Germany
| | - Luca Carnevali
- Stress Physiology Lab, Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parma, Italy
| | - David Molla
- Department of Biosciences, The PaceLab and "Centro Interuniversitario di Medicina Molecolare e Biofisica Applicata", Università degli Studi di Milano, Milan, Italy
| | - Andrea Barbuti
- Department of Biosciences, The PaceLab and "Centro Interuniversitario di Medicina Molecolare e Biofisica Applicata", Università degli Studi di Milano, Milan, Italy
| | - Dario DiFrancesco
- Department of Biosciences, The PaceLab and "Centro Interuniversitario di Medicina Molecolare e Biofisica Applicata", Università degli Studi di Milano, Milan, Italy.,IBF-CNR, University of Milano Unit, Milan, Italy
| | - Annalisa Bucchi
- Department of Biosciences, The PaceLab and "Centro Interuniversitario di Medicina Molecolare e Biofisica Applicata", Università degli Studi di Milano, Milan, Italy
| | - Mirko Baruscotti
- Department of Biosciences, The PaceLab and "Centro Interuniversitario di Medicina Molecolare e Biofisica Applicata", Università degli Studi di Milano, Milan, Italy
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9
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Giannetti F, Benzoni P, Campostrini G, Milanesi R, Bucchi A, Baruscotti M, Dell'Era P, Rossini A, Barbuti A. A detailed characterization of the hyperpolarization-activated "funny" current (I f) in human-induced pluripotent stem cell (iPSC)-derived cardiomyocytes with pacemaker activity. Pflugers Arch 2021; 473:1009-1021. [PMID: 33934225 PMCID: PMC8245366 DOI: 10.1007/s00424-021-02571-w] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2020] [Revised: 04/01/2021] [Accepted: 04/19/2021] [Indexed: 01/09/2023]
Abstract
Properties of the funny current (If) have been studied in several animal and cellular models, but so far little is known concerning its properties in human pacemaker cells. This work provides a detailed characterization of If in human-induced pluripotent stem cell (iPSC)–derived pacemaker cardiomyocytes (pCMs), at different time points. Patch-clamp analysis showed that If density did not change during differentiation; however, after day 30, it activates at more negative potential and with slower time constants. These changes are accompanied by a slowing in beating rate. If displayed the voltage-dependent block by caesium and reversed (Erev) at − 22 mV, compatibly with the 3:1 K+/Na+ permeability ratio. Lowering [Na+]o (30 mM) shifted the Erev to − 39 mV without affecting conductance. Increasing [K+]o (30 mM) shifted the Erev to − 15 mV with a fourfold increase in conductance. pCMs express mainly HCN4 and HCN1 together with the accessory subunits CAV3, KCR1, MiRP1, and SAP97 that contribute to the context-dependence of If. Autonomic agonists modulated the diastolic depolarization, and thus rate, of pCMs. The adrenergic agonist isoproterenol induced rate acceleration and a positive shift of If voltage-dependence (EC50 73.4 nM). The muscarinic agonists had opposite effects (Carbachol EC50, 11,6 nM). Carbachol effect was however small but it could be increased by pre-stimulation with isoproterenol, indicating low cAMP levels in pCMs. In conclusion, we demonstrated that pCMs display an If with the physiological properties expected by pacemaker cells and may thus represent a suitable model for studying human If-related sinus arrhythmias.
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Affiliation(s)
- Federica Giannetti
- The Cell Physiology MiLab, Department of Biosciences, Università degli Studi di Milano, Via Celoria 26, 20133, Milano, Italy
| | - Patrizia Benzoni
- The Cell Physiology MiLab, Department of Biosciences, Università degli Studi di Milano, Via Celoria 26, 20133, Milano, Italy
| | - Giulia Campostrini
- The Cell Physiology MiLab, Department of Biosciences, Università degli Studi di Milano, Via Celoria 26, 20133, Milano, Italy
- Department of Anatomy and Embryology, Leiden University Medical Center, Einthovenweg 20, 2333ZC, Leiden, The Netherlands
| | - Raffaella Milanesi
- The Cell Physiology MiLab, Department of Biosciences, Università degli Studi di Milano, Via Celoria 26, 20133, Milano, Italy
- Dipartimento di Medicina Veterinaria, Università degli Studi di Milano, Via dell'Università 6, 26900, Lodi, Italy
| | - Annalisa Bucchi
- The Cell Physiology MiLab, Department of Biosciences, Università degli Studi di Milano, Via Celoria 26, 20133, Milano, Italy
| | - Mirko Baruscotti
- The Cell Physiology MiLab, Department of Biosciences, Università degli Studi di Milano, Via Celoria 26, 20133, Milano, Italy
| | - Patrizia Dell'Era
- Cellular Fate Reprogramming Unit, Department of Molecular and Translational Medicine, University of Brescia, viale Europa 11, 25123, Brescia, Italy
| | - Alessandra Rossini
- Institute for Biomedicine, Eurac Research, Affiliated Institute of the University of Lübeck, Viale Druso 1, 39100, Bolzano, Italy
| | - Andrea Barbuti
- The Cell Physiology MiLab, Department of Biosciences, Università degli Studi di Milano, Via Celoria 26, 20133, Milano, Italy.
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10
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D'Souza A, Wang Y, Anderson C, Bucchi A, Baruscotti M, Olieslagers S, Mesirca P, Johnsen AB, Mastitskaya S, Ni H, Zhang Y, Black N, Cox C, Wegner S, Bano-Otalora B, Petit C, Gill E, Logantha SJRJ, Dobrzynski H, Ashton N, Hart G, Zhang R, Zhang H, Cartwright EJ, Wisloff U, Mangoni ME, da Costa Martins PA, Piggins HD, DiFrancesco D, Boyett MR. A circadian clock in the sinus node mediates day-night rhythms in Hcn4 and heart rate. Heart Rhythm 2020; 18:801-810. [PMID: 33278629 PMCID: PMC8073545 DOI: 10.1016/j.hrthm.2020.11.026] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Revised: 11/09/2020] [Accepted: 11/21/2020] [Indexed: 11/26/2022]
Abstract
Background Heart rate follows a diurnal variation, and slow heart rhythms occur primarily at night. Objective The lower heart rate during sleep is assumed to be neural in origin, but here we tested whether a day-night difference in intrinsic pacemaking is involved. Methods In vivo and in vitro electrocardiographic recordings, vagotomy, transgenics, quantitative polymerase chain reaction, Western blotting, immunohistochemistry, patch clamp, reporter bioluminescence recordings, and chromatin immunoprecipitation were used. Results The day-night difference in the average heart rate of mice was independent of fluctuations in average locomotor activity and persisted under pharmacological, surgical, and transgenic interruption of autonomic input to the heart. Spontaneous beating rate of isolated (ie, denervated) sinus node (SN) preparations exhibited a day-night rhythm concomitant with rhythmic messenger RNA expression of ion channels including hyperpolarization-activated cyclic nucleotide-gated potassium channel 4 (HCN4). In vitro studies demonstrated 24-hour rhythms in the human HCN4 promoter and the corresponding funny current. The day-night heart rate difference in mice was abolished by HCN block, both in vivo and in the isolated SN. Rhythmic expression of canonical circadian clock transcription factors, for example, Brain and muscle ARNT-Like 1 (BMAL1) and Cryptochrome (CRY) was identified in the SN and disruption of the local clock (by cardiomyocyte-specific knockout of Bmal1) abolished the day-night difference in Hcn4 and intrinsic heart rate. Chromatin immunoprecipitation revealed specific BMAL1 binding sites on Hcn4, linking the local clock with intrinsic rate control. Conclusion The circadian variation in heart rate involves SN local clock–dependent Hcn4 rhythmicity. Data reveal a novel regulator of heart rate and mechanistic insight into bradycardia during sleep.
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Affiliation(s)
- Alicia D'Souza
- Division of Cardiovascular Sciences, University of Manchester, Manchester, United Kingdom.
| | - Yanwen Wang
- Division of Cardiovascular Sciences, University of Manchester, Manchester, United Kingdom
| | - Cali Anderson
- Division of Cardiovascular Sciences, University of Manchester, Manchester, United Kingdom
| | - Annalisa Bucchi
- Department of Biosciences, University of Milan, Milan, Italy
| | | | - Servé Olieslagers
- Department of Cardiology, Maastricht University, Maastricht, The Netherlands
| | - Pietro Mesirca
- Institut de Génomique Fonctionnelle, Université de Montpellie, CNRS, Montpellier, France
| | - Anne Berit Johnsen
- Department of Circulation and Medical Imaging, Norwegian University of Science and Technology, Trondheim, Norway
| | - Svetlana Mastitskaya
- Neuroscience, Physiology and Pharmacology, University College London, London, United Kingdom
| | - Haibo Ni
- Division of Cardiovascular Sciences, University of Manchester, Manchester, United Kingdom
| | - Yu Zhang
- Division of Cardiovascular Sciences, University of Manchester, Manchester, United Kingdom
| | - Nicholas Black
- Division of Cardiovascular Sciences, University of Manchester, Manchester, United Kingdom
| | - Charlotte Cox
- Division of Cardiovascular Sciences, University of Manchester, Manchester, United Kingdom
| | - Sven Wegner
- Division of Cardiovascular Sciences, University of Manchester, Manchester, United Kingdom
| | - Beatriz Bano-Otalora
- Division of Cardiovascular Sciences, University of Manchester, Manchester, United Kingdom
| | - Cheryl Petit
- Division of Cardiovascular Sciences, University of Manchester, Manchester, United Kingdom
| | - Eleanor Gill
- Division of Cardiovascular Sciences, University of Manchester, Manchester, United Kingdom
| | - Sunil Jit R J Logantha
- Division of Cardiovascular Sciences, University of Manchester, Manchester, United Kingdom; Liverpool Centre for Cardiovascular Sciences, University of Liverpool, Liverpool, UK
| | - Halina Dobrzynski
- Division of Cardiovascular Sciences, University of Manchester, Manchester, United Kingdom
| | - Nick Ashton
- Division of Cardiovascular Sciences, University of Manchester, Manchester, United Kingdom
| | - George Hart
- Division of Cardiovascular Sciences, University of Manchester, Manchester, United Kingdom
| | - Rai Zhang
- School of Civil, Aerospace and Mechanical Engineering, University of Bristol, Bristol, United Kingdom
| | - Henggui Zhang
- Division of Cardiovascular Sciences, University of Manchester, Manchester, United Kingdom
| | - Elizabeth J Cartwright
- Division of Cardiovascular Sciences, University of Manchester, Manchester, United Kingdom
| | - Ulrik Wisloff
- Department of Circulation and Medical Imaging, Norwegian University of Science and Technology, Trondheim, Norway
| | - Matteo E Mangoni
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | | | - Hugh D Piggins
- School of Physiology, Pharmacology & Neuroscience, University of Bristol, Bristol, United Kingdom
| | - Dario DiFrancesco
- Department of Biosciences, University of Milan, Milan, Italy; IBF-CNR, Milan, Italy
| | - Mark R Boyett
- Division of Cardiovascular Sciences, University of Manchester, Manchester, United Kingdom; Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
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11
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Frosio A, Molla D, Bertoli G, Bazzini C, Milanesi R, Gennaro F, Barbuti A, Bucchi A, Moretti L, Marchese P, DiFrancesco D, Baruscotti M. Abstract 808: Functional Characterization of a Novel Scn5a Mutation Associated With the Brugada Syndrome. Circ Res 2019. [DOI: 10.1161/res.125.suppl_1.808] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Background:
Brugada syndrome (BrS) is a cardiac disorder characterized by conduction abnormalities that can lead to sudden death; syncope and cardiac arrest are clinical manifestations which are often associated with an enhancement of the vagal activity. Mutations in the SCN5A gene (Na
v
1.5 channel) are the most common cause of the inherited forms of BrS.
Objective:
To characterize the functional behavior of mutant Na
v
1.5 channels expressing a novel heterozygous mutation (S805L) recently identified in an Italian family affected by the BrS.
Methods:
HEK cells were used as experimental model to express both the wild-type (WT) and the mutated S805L channels (alone, Homo or in combination, Hetero) and the accessory β-subunit (SCN1B). Patch-clamp and western blot experiments were carried out to assess the dysfunctional role of the mutation.
Results:
When compared to the WT current, the S508L mutation significantly (P&It0.05) decreases the peak current density by about 65% for the Homo condition (WT: -120.2±10.2, n=28); Homo: -40.3±4.2, n=16) and by 35% for the Hetero condition (Hetero: -78.2±8.3, n=27). Densitometric analysis carried out on western blot data further support the conclusion that S805L channels are less abundant in the plasma membrane. We also observed that the S805L mutation positively shifts the V½ values of the voltage dependence of the inactivation of both Homo and Hetero currents (V½: WT -85.5±0.2 mV, n=55; Homo -80.9±0.3 mV, n=22; Hetero -81.9±0.2 mV, n=25; P&It0.05); a positive shift of the V½ of the activation was also observed but only in the Homo condition (V½: WT -33.0±0.4 mV, n=28; Homo -30.0±0.5, n=16, P&It0.05). The kinetics of recovery from inactivation and the amplitude of the late sodium current were also evaluated but they were unaffected by the mutation.
Conclusion:
When expressed in the Hetero condition, the S805L mutation causes a reduction in the channel expression, however, the positive shift of the inactivation curve suggests an increase in Na channel availability. We thus believe that the precise quantitative balance between these two phenomena and their relation with vagal activity may underlie the clinical manifestation of the disease.
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Affiliation(s)
| | - David Molla
- Università degli Studi di MIlano, Milano, Italy
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12
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Baruscotti M, Bucchi A, Milanesi R, Paina M, Barbuti A, Gnecchi-Ruscone T, Bianco E, Vitali-Serdoz L, Cappato R, DiFrancesco D. A gain-of-function mutation in the cardiac pacemaker HCN4 channel increasing cAMP sensitivity is associated with familial Inappropriate Sinus Tachycardia. Eur Heart J 2019; 38:280-288. [PMID: 28182231 DOI: 10.1093/eurheartj/ehv582] [Citation(s) in RCA: 62] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/09/2015] [Revised: 10/01/2015] [Accepted: 10/07/2015] [Indexed: 01/09/2023] Open
Affiliation(s)
- Mirko Baruscotti
- Department of Biosciences, The PaceLab and 'Centro Interuniversitario di Medicina Molecolare e Biofisica Applicata', Università degli Studi di Milano, via Celoria 26, 20133 Milano, Italy
| | - Annalisa Bucchi
- Department of Biosciences, The PaceLab and 'Centro Interuniversitario di Medicina Molecolare e Biofisica Applicata', Università degli Studi di Milano, via Celoria 26, 20133 Milano, Italy
| | - Raffaella Milanesi
- Department of Biosciences, The PaceLab and 'Centro Interuniversitario di Medicina Molecolare e Biofisica Applicata', Università degli Studi di Milano, via Celoria 26, 20133 Milano, Italy
| | - Manuel Paina
- Department of Biosciences, The PaceLab and 'Centro Interuniversitario di Medicina Molecolare e Biofisica Applicata', Università degli Studi di Milano, via Celoria 26, 20133 Milano, Italy
| | - Andrea Barbuti
- Department of Biosciences, The PaceLab and 'Centro Interuniversitario di Medicina Molecolare e Biofisica Applicata', Università degli Studi di Milano, via Celoria 26, 20133 Milano, Italy
| | | | - Elisabetta Bianco
- Cardiovascular Department, 'Ospedali Riuniti di Trieste', University Hospital, Trieste, Italy
| | | | | | - Dario DiFrancesco
- Department of Biosciences, The PaceLab and 'Centro Interuniversitario di Medicina Molecolare e Biofisica Applicata', Università degli Studi di Milano, via Celoria 26, 20133 Milano, Italy
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13
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Saponaro A, Cantini F, Porro A, Bucchi A, DiFrancesco D, Maione V, Laskowski M, Mesirca P, Mangoni M, Thiel G, Banci L, Santoro B, Moroni A. Developing Synthetic Peptides to Regulate Native HCN Channels. Biophys J 2019. [DOI: 10.1016/j.bpj.2018.11.1638] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
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14
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Campostrini G, DiFrancesco JC, Castellotti B, Milanesi R, Gnecchi-Ruscone T, Bonzanni M, Bucchi A, Baruscotti M, Ferrarese C, Franceschetti S, Canafoglia L, Ragona F, Freri E, Labate A, Gambardella A, Costa C, Gellera C, Granata T, Barbuti A, DiFrancesco D. A Loss-of-Function HCN4 Mutation Associated With Familial Benign Myoclonic Epilepsy in Infancy Causes Increased Neuronal Excitability. Front Mol Neurosci 2018; 11:269. [PMID: 30127718 PMCID: PMC6089338 DOI: 10.3389/fnmol.2018.00269] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2018] [Accepted: 07/16/2018] [Indexed: 01/03/2023] Open
Abstract
HCN channels are highly expressed and functionally relevant in neurons and increasing evidence demonstrates their involvement in the etiology of human epilepsies. Among HCN isoforms, HCN4 is important in cardiac tissue, where it underlies pacemaker activity. Despite being expressed also in deep structures of the brain, mutations of this channel functionally shown to be associated with epilepsy have not been reported yet. Using Next Generation Sequencing for the screening of patients with idiopathic epilepsy, we identified the p.Arg550Cys (c.1648C>T) heterozygous mutation on HCN4 in two brothers affected by benign myoclonic epilepsy of infancy. Functional characterization in heterologous expression system and in neurons showed that the mutation determines a loss of function of HCN4 contribution to activity and an increase of neuronal discharge, potentially predisposing to epilepsy. Expressed in cardiomyocytes, mutant channels activate at slightly more negative voltages than wild-type (WT), in accordance with borderline bradycardia. While HCN4 variants have been frequently associated with cardiac arrhythmias, these data represent the first experimental evidence that functional alteration of HCN4 can also be involved in human epilepsy through a loss-of-function effect and associated increased neuronal excitability. Since HCN4 appears to be highly expressed in deep brain structures only early during development, our data provide a potential explanation for a link between dysfunctional HCN4 and infantile epilepsy. These findings suggest that it may be useful to include HCN4 screening to extend the knowledge of the genetic causes of infantile epilepsies, potentially paving the way for the identification of innovative therapeutic strategies.
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Affiliation(s)
- Giulia Campostrini
- Molecular Physiology and Neurobiology, The PaceLab, Department of Biosciences, Università degli Studi di Milano, Milan, Italy
| | - Jacopo C DiFrancesco
- Clinical Neurophysiology and Epilepsy Center, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy.,Laboratory of Neurobiology, Department of Neurology, Milan Center for Neuroscience, San Gerardo Hospital, University of Milano-Bicocca, Monza, Italy
| | - Barbara Castellotti
- Unit of Genetics of Neurodegenerative and Metabolic Diseases, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Raffaella Milanesi
- Molecular Physiology and Neurobiology, The PaceLab, Department of Biosciences, Università degli Studi di Milano, Milan, Italy
| | | | - Mattia Bonzanni
- Molecular Physiology and Neurobiology, The PaceLab, Department of Biosciences, Università degli Studi di Milano, Milan, Italy
| | - Annalisa Bucchi
- Molecular Physiology and Neurobiology, The PaceLab, Department of Biosciences, Università degli Studi di Milano, Milan, Italy
| | - Mirko Baruscotti
- Molecular Physiology and Neurobiology, The PaceLab, Department of Biosciences, Università degli Studi di Milano, Milan, Italy
| | - Carlo Ferrarese
- Laboratory of Neurobiology, Department of Neurology, Milan Center for Neuroscience, San Gerardo Hospital, University of Milano-Bicocca, Monza, Italy
| | - Silvana Franceschetti
- Clinical Neurophysiology and Epilepsy Center, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Laura Canafoglia
- Clinical Neurophysiology and Epilepsy Center, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Francesca Ragona
- Department of Pediatric Neuroscience, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Elena Freri
- Department of Pediatric Neuroscience, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Angelo Labate
- Institute of Neurology, Università degli Studi Magna Græcia di Catanzaro, Catanzaro, Italy
| | - Antonio Gambardella
- Institute of Neurology, Università degli Studi Magna Græcia di Catanzaro, Catanzaro, Italy
| | - Cinzia Costa
- Neurology Unit, Ospedale S. Maria della Misericordia, Department of Medicine, University of Perugia, Perugia, Italy
| | - Cinzia Gellera
- Unit of Genetics of Neurodegenerative and Metabolic Diseases, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Tiziana Granata
- Department of Pediatric Neuroscience, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Andrea Barbuti
- Molecular Physiology and Neurobiology, The PaceLab, Department of Biosciences, Università degli Studi di Milano, Milan, Italy
| | - Dario DiFrancesco
- Molecular Physiology and Neurobiology, The PaceLab, Department of Biosciences, Università degli Studi di Milano, Milan, Italy
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15
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Bonzanni M, DiFrancesco JC, Milanesi R, Campostrini G, Castellotti B, Bucchi A, Baruscotti M, Ferrarese C, Franceschetti S, Canafoglia L, Ragona F, Freri E, Labate A, Gambardella A, Costa C, Rivolta I, Gellera C, Granata T, Barbuti A, DiFrancesco D. A novel de novo HCN1 loss-of-function mutation in genetic generalized epilepsy causing increased neuronal excitability. Neurobiol Dis 2018; 118:55-63. [PMID: 29936235 DOI: 10.1016/j.nbd.2018.06.012] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2018] [Revised: 06/11/2018] [Accepted: 06/15/2018] [Indexed: 11/26/2022] Open
Abstract
The causes of genetic epilepsies are unknown in the majority of patients. HCN ion channels have a widespread expression in neurons and increasing evidence demonstrates their functional involvement in human epilepsies. Among the four known isoforms, HCN1 is the most expressed in the neocortex and hippocampus and de novo HCN1 point mutations have been recently associated with early infantile epileptic encephalopathy. So far, HCN1 mutations have not been reported in patients with idiopathic epilepsy. Using a Next Generation Sequencing approach, we identified the de novo heterozygous p.Leu157Val (c.469C > G) novel mutation in HCN1 in an adult male patient affected by genetic generalized epilepsy (GGE), with normal cognitive development. Electrophysiological analysis in heterologous expression model (CHO cells) and in neurons revealed that L157V is a loss-of-function, dominant negative mutation causing reduced HCN1 contribution to net inward current and responsible for an increased neuronal firing rate and excitability, potentially predisposing to epilepsy. These data represent the first evidence that autosomal dominant missense mutations of HCN1 can also be involved in GGE, without the characteristics of epileptic encephalopathy reported previously. It will be important to include HCN1 screening in patients with GGE, in order to extend the knowledge of the genetic causes of idiopathic epilepsies, thus paving the way for the identification of innovative therapeutic strategies.
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Affiliation(s)
- Mattia Bonzanni
- Dept. of Biosciences, The PaceLab, University of Milano, Milano, Italy
| | - Jacopo C DiFrancesco
- Clinical Neurophysiology and Epilepsy Center, "C. Besta" Neurological Institute, Milano, Italy; Dept. of Neurology, San Gerardo Hospital, Laboratory of Neurobiology, Milan Center for Neuroscience, University of Milano-Bicocca, Monza, Italy.
| | | | | | - Barbara Castellotti
- Unit of Genetics of Neurodegenerative and Metabolic Diseases, "C. Besta" Neurological Institute, Milano, Italy
| | - Annalisa Bucchi
- Dept. of Biosciences, The PaceLab, University of Milano, Milano, Italy
| | - Mirko Baruscotti
- Dept. of Biosciences, The PaceLab, University of Milano, Milano, Italy
| | - Carlo Ferrarese
- Dept. of Neurology, San Gerardo Hospital, Laboratory of Neurobiology, Milan Center for Neuroscience, University of Milano-Bicocca, Monza, Italy
| | - Silvana Franceschetti
- Clinical Neurophysiology and Epilepsy Center, "C. Besta" Neurological Institute, Milano, Italy
| | - Laura Canafoglia
- Clinical Neurophysiology and Epilepsy Center, "C. Besta" Neurological Institute, Milano, Italy
| | - Francesca Ragona
- Dept. of Pediatric Neuroscience, "C. Besta" Neurological Institute, Milano, Italy
| | - Elena Freri
- Dept. of Pediatric Neuroscience, "C. Besta" Neurological Institute, Milano, Italy
| | - Angelo Labate
- Institute of Neurology, University "Magna Graecia", Catanzaro, Italy
| | | | - Cinzia Costa
- Neurology Unit, Department of Medicine, University of Perugia, Ospedale S. Maria della Misericordia, Perugia, Italy
| | - Ilaria Rivolta
- School of Medicine and Surgery, Milan Center for Neuroscience and Nanomedicine Center, University of Milano-Bicocca, Monza, Italy
| | - Cinzia Gellera
- Unit of Genetics of Neurodegenerative and Metabolic Diseases, "C. Besta" Neurological Institute, Milano, Italy
| | - Tiziana Granata
- Dept. of Pediatric Neuroscience, "C. Besta" Neurological Institute, Milano, Italy
| | - Andrea Barbuti
- Dept. of Biosciences, The PaceLab, University of Milano, Milano, Italy.
| | - Dario DiFrancesco
- Dept. of Biosciences, The PaceLab, University of Milano, Milano, Italy
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16
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Saponaro A, Cantini F, Porro A, Bucchi A, DiFrancesco D, Maione V, Donadoni C, Introini B, Mesirca P, Mangoni ME, Thiel G, Banci L, Santoro B, Moroni A. A synthetic peptide that prevents cAMP regulation in mammalian hyperpolarization-activated cyclic nucleotide-gated (HCN) channels. eLife 2018; 7:35753. [PMID: 29923826 PMCID: PMC6023613 DOI: 10.7554/elife.35753] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2018] [Accepted: 06/14/2018] [Indexed: 12/13/2022] Open
Abstract
Binding of TRIP8b to the cyclic nucleotide binding domain (CNBD) of mammalian hyperpolarization-activated cyclic nucleotide-gated (HCN) channels prevents their regulation by cAMP. Since TRIP8b is expressed exclusively in the brain, we envisage that it can be used for orthogonal control of HCN channels beyond the central nervous system. To this end, we have identified by rational design a 40-aa long peptide (TRIP8bnano) that recapitulates affinity and gating effects of TRIP8b in HCN isoforms (hHCN1, mHCN2, rbHCN4) and in the cardiac current If in rabbit and mouse sinoatrial node cardiomyocytes. Guided by an NMR-derived structural model that identifies the key molecular interactions between TRIP8bnano and the HCN CNBD, we further designed a cell-penetrating peptide (TAT-TRIP8bnano) which successfully prevented β-adrenergic activation of mouse If leaving the stimulation of the L-type calcium current (ICaL) unaffected. TRIP8bnano represents a novel approach to selectively control HCN activation, which yields the promise of a more targeted pharmacology compared to pore blockers.
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Affiliation(s)
- Andrea Saponaro
- Department of Biosciences, University of Milan, Milan, Italy
| | - Francesca Cantini
- Department of Chemistry, University of Florence, Florence, Italy.,Magnetic Resonance Center, University of Florence, Florence, Italy
| | | | - Annalisa Bucchi
- Department of Biosciences, University of Milan, Milan, Italy
| | | | - Vincenzo Maione
- Interuniversity Consortium for Magnetic Resonance of Metalloproteins, Sesto Fiorentino, Italy
| | - Chiara Donadoni
- Department of Biosciences, University of Milan, Milan, Italy
| | - Bianca Introini
- Department of Biosciences, University of Milan, Milan, Italy
| | - Pietro Mesirca
- Institut de Génomique Fonctionnelle, CNRS, INSERM F-34094, Université de Montpellier, Montpellier, France.,Laboratory of Excellence Ion Channels Science and Therapeutics, Valbonne, France
| | - Matteo E Mangoni
- Institut de Génomique Fonctionnelle, CNRS, INSERM F-34094, Université de Montpellier, Montpellier, France.,Laboratory of Excellence Ion Channels Science and Therapeutics, Valbonne, France
| | - Gerhard Thiel
- Department of Biology, TU-Darmstadt, Darmstadt, Germany
| | - Lucia Banci
- Department of Chemistry, University of Florence, Florence, Italy.,Magnetic Resonance Center, University of Florence, Florence, Italy.,Interuniversity Consortium for Magnetic Resonance of Metalloproteins, Sesto Fiorentino, Italy.,Institute of Neurosciences, Consiglio Nazionale delle Ricerche, Florence, Italy
| | - Bina Santoro
- Department of Neuroscience, Columbia University, New York, United States
| | - Anna Moroni
- Department of Biosciences, University of Milan, Milan, Italy.,Institute of Biophysics, Consiglio Nazionale delle Ricerche, Milan, Italy
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17
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Campostrini G, Bonzanni M, Lissoni A, Bazzini C, Milanesi R, Vezzoli E, Francolini M, Baruscotti M, Bucchi A, Rivolta I, Fantini M, Severi S, Cappato R, Crotti L, J Schwartz P, DiFrancesco D, Barbuti A. The expression of the rare caveolin-3 variant T78M alters cardiac ion channels function and membrane excitability. Cardiovasc Res 2018; 113:1256-1265. [PMID: 28898996 PMCID: PMC5852518 DOI: 10.1093/cvr/cvx122] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/07/2016] [Accepted: 06/19/2017] [Indexed: 01/03/2023] Open
Abstract
Aims Caveolinopathies are a family of genetic disorders arising from alterations of the caveolin-3 (cav-3) gene. The T78M cav-3 variant has been associated with both skeletal and cardiac muscle pathologies but its functional contribution, especially to cardiac diseases, is still controversial. Here, we evaluated the effect of the T78M cav-3 variant on cardiac ion channel function and membrane excitability. Methods and results We transfected either the wild type (WT) or T78M cav-3 in caveolin-1 knock-out mouse embryonic fibroblasts and found by immunofluorescence and electron microscopy that both are expressed at the plasma membrane and form caveolae. Two ion channels known to interact and co-immunoprecipitate with the cav-3, hKv1.5 and hHCN4, interact also with T78M cav-3 and reside in lipid rafts. Electrophysiological analysis showed that the T78M cav-3 causes hKv1.5 channels to activate and inactivate at more hyperpolarized potentials and the hHCN4 channels to activate at more depolarized potentials, in a dominant way. In spontaneously beating neonatal cardiomyocytes, the expression of the T78M cav-3 significantly increased action potential peak-to-peak variability without altering neither the mean rate nor the maximum diastolic potential. We also found that in a small cohort of patients with supraventricular arrhythmias, the T78M cav-3 variant is more frequent than in the general population. Finally, in silico analysis of both sinoatrial and atrial cell models confirmed that the T78M-dependent changes are compatible with a pro-arrhythmic effect. Conclusion This study demonstrates that the T78M cav-3 induces complex modifications in ion channel function that ultimately alter membrane excitability. The presence of the T78M cav-3 can thus generate a susceptible substrate that, in concert with other structural alterations and/or genetic mutations, may become arrhythmogenic.
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Affiliation(s)
- Giulia Campostrini
- Department of Biosciences, The PaceLab, Università degli Studi di Milano, Milano, Italy
| | - Mattia Bonzanni
- Department of Biosciences, The PaceLab, Università degli Studi di Milano, Milano, Italy
| | - Alessio Lissoni
- Department of Biosciences, The PaceLab, Università degli Studi di Milano, Milano, Italy
| | - Claudia Bazzini
- Department of Biosciences, The PaceLab, Università degli Studi di Milano, Milano, Italy
| | - Raffaella Milanesi
- Department of Biosciences, The PaceLab, Università degli Studi di Milano, Milano, Italy
| | - Elena Vezzoli
- Department of Medical Biotechnology and Translational Medicine, Università degli Studi di Milano, Milano, Italy.,Department of Pharmacological and Biomolecular Sciences, Università degli Studi di Milano, Milano, Italy
| | - Maura Francolini
- Department of Medical Biotechnology and Translational Medicine, Università degli Studi di Milano, Milano, Italy
| | - Mirko Baruscotti
- Department of Biosciences, The PaceLab, Università degli Studi di Milano, Milano, Italy.,Centro Interuniversitario di Medicina Molecolare e Biofisica Applicata (CIMMBA), Università degli Studi di Milano, Milano, Italy
| | - Annalisa Bucchi
- Department of Biosciences, The PaceLab, Università degli Studi di Milano, Milano, Italy
| | - Ilaria Rivolta
- Department of Health Science, Università di Milano Bicocca, Monza, Italy
| | - Matteo Fantini
- Cellular and Molecular Engineering Laboratory 'S. Cavalcanti', Department of Electrical, Electronic and Information Engineering 'Guglielmo Marconi', University of Bologna, Bologna, Italy
| | - Stefano Severi
- Cellular and Molecular Engineering Laboratory 'S. Cavalcanti', Department of Electrical, Electronic and Information Engineering 'Guglielmo Marconi', University of Bologna, Bologna, Italy
| | - Riccardo Cappato
- Arrhythmia & Electrophysiology Unit II, Humanitas Gavazzeni Clinics, Bergamo, Italy.,Arrhythmia & Electrophysiology Research Center, IRCCS Humanitas Research Hospital, Rozzano (Milan), Italy
| | - Lia Crotti
- Center for Cardiac Arrhythmias of Genetic Origin, IRCCS Istituto Auxologico Italiano, Milano, Italy.,Department of Molecular Medicine, University of Pavia, Pavia, Italy.,Department of Cardiovascular, Neural and Metabolic Sciences, San Luca Hospital IRCCS Istituto Auxologico Italiano, Milan, Italy
| | - Peter J Schwartz
- Center for Cardiac Arrhythmias of Genetic Origin, IRCCS Istituto Auxologico Italiano, Milano, Italy
| | - Dario DiFrancesco
- Department of Biosciences, The PaceLab, Università degli Studi di Milano, Milano, Italy.,Centro Interuniversitario di Medicina Molecolare e Biofisica Applicata (CIMMBA), Università degli Studi di Milano, Milano, Italy
| | - Andrea Barbuti
- Department of Biosciences, The PaceLab, Università degli Studi di Milano, Milano, Italy.,Centro Interuniversitario di Medicina Molecolare e Biofisica Applicata (CIMMBA), Università degli Studi di Milano, Milano, Italy
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18
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Yavari A, Bellahcene M, Bucchi A, Sirenko S, Pinter K, Herring N, Jung JJ, Tarasov KV, Sharpe EJ, Wolfien M, Czibik G, Steeples V, Ghaffari S, Nguyen C, Stockenhuber A, Clair JRS, Rimmbach C, Okamoto Y, Yang D, Wang M, Ziman BD, Moen JM, Riordon DR, Ramirez C, Paina M, Lee J, Zhang J, Ahmet I, Matt MG, Tarasova YS, Baban D, Sahgal N, Lockstone H, Puliyadi R, de Bono J, Siggs OM, Gomes J, Muskett H, Maguire ML, Beglov Y, Kelly M, Dos Santos PPN, Bright NJ, Woods A, Gehmlich K, Isackson H, Douglas G, Ferguson DJP, Schneider JE, Tinker A, Wolkenhauer O, Channon KM, Cornall RJ, Sternick EB, Paterson DJ, Redwood CS, Carling D, Proenza C, David R, Baruscotti M, DiFrancesco D, Lakatta EG, Watkins H, Ashrafian H. Mammalian γ2 AMPK regulates intrinsic heart rate. Nat Commun 2017; 8:1258. [PMID: 29097735 PMCID: PMC5668267 DOI: 10.1038/s41467-017-01342-5] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2017] [Accepted: 09/08/2017] [Indexed: 11/22/2022] Open
Abstract
AMPK is a conserved serine/threonine kinase whose activity maintains cellular energy homeostasis. Eukaryotic AMPK exists as αβγ complexes, whose regulatory γ subunit confers energy sensor function by binding adenine nucleotides. Humans bearing activating mutations in the γ2 subunit exhibit a phenotype including unexplained slowing of heart rate (bradycardia). Here, we show that γ2 AMPK activation downregulates fundamental sinoatrial cell pacemaker mechanisms to lower heart rate, including sarcolemmal hyperpolarization-activated current (I f) and ryanodine receptor-derived diastolic local subsarcolemmal Ca2+ release. In contrast, loss of γ2 AMPK induces a reciprocal phenotype of increased heart rate, and prevents the adaptive intrinsic bradycardia of endurance training. Our results reveal that in mammals, for which heart rate is a key determinant of cardiac energy demand, AMPK functions in an organ-specific manner to maintain cardiac energy homeostasis and determines cardiac physiological adaptation to exercise by modulating intrinsic sinoatrial cell behavior.
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Affiliation(s)
- Arash Yavari
- Experimental Therapeutics, Radcliffe Department of Medicine, University of Oxford, Oxford, OX3 9DU, UK.
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, OX3 9DU, UK.
- The Wellcome Trust Centre for Human Genetics, Oxford, OX3 7BN, UK.
| | - Mohamed Bellahcene
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, OX3 9DU, UK
- The Wellcome Trust Centre for Human Genetics, Oxford, OX3 7BN, UK
| | - Annalisa Bucchi
- Department of Biosciences, Università degli Studi di Milano, Milan, 20133, Italy
- Centro Interuniversitario di Medicina Molecolare e Biofisica Applicata, University of Milano, Milan, 20133, Italy
| | - Syevda Sirenko
- Laboratory of Cardiovascular Science, Intramural Research Program, National Institute on Aging, NIH, Baltimore, MD, 21224, USA
| | - Katalin Pinter
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, OX3 9DU, UK
- The Wellcome Trust Centre for Human Genetics, Oxford, OX3 7BN, UK
| | - Neil Herring
- Burdon Sanderson Cardiac Science Centre, Department of Physiology, Anatomy & Genetics, University of Oxford, Oxford, OX1 3PT, UK
| | - Julia J Jung
- Department of Cardiac Surgery, Rostock University Medical Centre, 18057, Rostock, Germany
- Department Life, Light and Matter, Interdisciplinary Faculty, Rostock University, 18059, Rostock, Germany
| | - Kirill V Tarasov
- Laboratory of Cardiovascular Science, Intramural Research Program, National Institute on Aging, NIH, Baltimore, MD, 21224, USA
| | - Emily J Sharpe
- Department of Physiology and Biophysics, University of Colorado School of Medicine, Aurora, CO, 80045, USA
| | - Markus Wolfien
- Department of Systems Biology and Bioinformatics, University of Rostock, Rostock, 18051, Germany
| | - Gabor Czibik
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, OX3 9DU, UK
- The Wellcome Trust Centre for Human Genetics, Oxford, OX3 7BN, UK
| | - Violetta Steeples
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, OX3 9DU, UK
- The Wellcome Trust Centre for Human Genetics, Oxford, OX3 7BN, UK
| | - Sahar Ghaffari
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, OX3 9DU, UK
- The Wellcome Trust Centre for Human Genetics, Oxford, OX3 7BN, UK
| | - Chinh Nguyen
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, OX3 9DU, UK
- The Wellcome Trust Centre for Human Genetics, Oxford, OX3 7BN, UK
| | - Alexander Stockenhuber
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, OX3 9DU, UK
- The Wellcome Trust Centre for Human Genetics, Oxford, OX3 7BN, UK
| | - Joshua R St Clair
- Department of Physiology and Biophysics, University of Colorado School of Medicine, Aurora, CO, 80045, USA
| | - Christian Rimmbach
- Department of Cardiac Surgery, Rostock University Medical Centre, 18057, Rostock, Germany
- Department Life, Light and Matter, Interdisciplinary Faculty, Rostock University, 18059, Rostock, Germany
| | - Yosuke Okamoto
- Laboratory of Cardiovascular Science, Intramural Research Program, National Institute on Aging, NIH, Baltimore, MD, 21224, USA
| | - Dongmei Yang
- Laboratory of Cardiovascular Science, Intramural Research Program, National Institute on Aging, NIH, Baltimore, MD, 21224, USA
| | - Mingyi Wang
- Laboratory of Cardiovascular Science, Intramural Research Program, National Institute on Aging, NIH, Baltimore, MD, 21224, USA
| | - Bruce D Ziman
- Laboratory of Cardiovascular Science, Intramural Research Program, National Institute on Aging, NIH, Baltimore, MD, 21224, USA
| | - Jack M Moen
- Laboratory of Cardiovascular Science, Intramural Research Program, National Institute on Aging, NIH, Baltimore, MD, 21224, USA
| | - Daniel R Riordon
- Laboratory of Cardiovascular Science, Intramural Research Program, National Institute on Aging, NIH, Baltimore, MD, 21224, USA
| | - Christopher Ramirez
- Laboratory of Cardiovascular Science, Intramural Research Program, National Institute on Aging, NIH, Baltimore, MD, 21224, USA
| | - Manuel Paina
- Department of Biosciences, Università degli Studi di Milano, Milan, 20133, Italy
- Centro Interuniversitario di Medicina Molecolare e Biofisica Applicata, University of Milano, Milan, 20133, Italy
| | - Joonho Lee
- Laboratory of Cardiovascular Science, Intramural Research Program, National Institute on Aging, NIH, Baltimore, MD, 21224, USA
| | - Jing Zhang
- Laboratory of Cardiovascular Science, Intramural Research Program, National Institute on Aging, NIH, Baltimore, MD, 21224, USA
| | - Ismayil Ahmet
- Laboratory of Cardiovascular Science, Intramural Research Program, National Institute on Aging, NIH, Baltimore, MD, 21224, USA
| | - Michael G Matt
- Laboratory of Cardiovascular Science, Intramural Research Program, National Institute on Aging, NIH, Baltimore, MD, 21224, USA
| | - Yelena S Tarasova
- Laboratory of Cardiovascular Science, Intramural Research Program, National Institute on Aging, NIH, Baltimore, MD, 21224, USA
| | - Dilair Baban
- The Wellcome Trust Centre for Human Genetics, Oxford, OX3 7BN, UK
| | - Natasha Sahgal
- The Wellcome Trust Centre for Human Genetics, Oxford, OX3 7BN, UK
| | - Helen Lockstone
- The Wellcome Trust Centre for Human Genetics, Oxford, OX3 7BN, UK
| | - Rathi Puliyadi
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, OX3 9DU, UK
- The Wellcome Trust Centre for Human Genetics, Oxford, OX3 7BN, UK
| | - Joseph de Bono
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, OX3 9DU, UK
- The Wellcome Trust Centre for Human Genetics, Oxford, OX3 7BN, UK
| | - Owen M Siggs
- The Wellcome Trust Centre for Human Genetics, Oxford, OX3 7BN, UK
- MRC Human Immunology Unit, Weatherall Institute for Molecular Medicine, Nuffield Department of Medicine, University of Oxford, Oxford, OX3 9DS, UK
| | - John Gomes
- Department of Medicine, BHF Laboratories, The Rayne Institute, University College London, London, WC1E 6JJ, UK
| | - Hannah Muskett
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, OX3 9DU, UK
- The Wellcome Trust Centre for Human Genetics, Oxford, OX3 7BN, UK
| | - Mahon L Maguire
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, OX3 9DU, UK
- The Wellcome Trust Centre for Human Genetics, Oxford, OX3 7BN, UK
| | - Youlia Beglov
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, OX3 9DU, UK
- The Wellcome Trust Centre for Human Genetics, Oxford, OX3 7BN, UK
| | - Matthew Kelly
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, OX3 9DU, UK
- The Wellcome Trust Centre for Human Genetics, Oxford, OX3 7BN, UK
| | - Pedro P N Dos Santos
- Instituto de Pós-Graduação, Faculdade de Ciências Médicas de Minas Gerais, Belo Horizonte, 30.130-110, Brazil
| | - Nicola J Bright
- Cellular Stress Group, MRC London Institute of Medical Sciences, Imperial College London, London, W12 0NN, UK
| | - Angela Woods
- Cellular Stress Group, MRC London Institute of Medical Sciences, Imperial College London, London, W12 0NN, UK
| | - Katja Gehmlich
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, OX3 9DU, UK
- The Wellcome Trust Centre for Human Genetics, Oxford, OX3 7BN, UK
| | - Henrik Isackson
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, OX3 9DU, UK
| | - Gillian Douglas
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, OX3 9DU, UK
- The Wellcome Trust Centre for Human Genetics, Oxford, OX3 7BN, UK
| | - David J P Ferguson
- Nuffield Department of Clinical Laboratory Science, University of Oxford, Oxford, OX3 9DU, UK
| | - Jürgen E Schneider
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, OX3 9DU, UK
- The Wellcome Trust Centre for Human Genetics, Oxford, OX3 7BN, UK
| | - Andrew Tinker
- Department of Medicine, BHF Laboratories, The Rayne Institute, University College London, London, WC1E 6JJ, UK
- The Heart Centre, William Harvey Research Institute, Barts and the London School of Medicine and Dentistry, London, EC1M 6BQ, UK
| | - Olaf Wolkenhauer
- Department of Systems Biology and Bioinformatics, University of Rostock, Rostock, 18051, Germany
- Stellenbosch Institute of Advanced Study (STIAS), Wallenberg Research Centre at Stellenbosch University, Stellenbosch, 7602, South Africa
| | - Keith M Channon
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, OX3 9DU, UK
- The Wellcome Trust Centre for Human Genetics, Oxford, OX3 7BN, UK
| | - Richard J Cornall
- The Wellcome Trust Centre for Human Genetics, Oxford, OX3 7BN, UK
- MRC Human Immunology Unit, Weatherall Institute for Molecular Medicine, Nuffield Department of Medicine, University of Oxford, Oxford, OX3 9DS, UK
| | - Eduardo B Sternick
- Instituto de Pós-Graduação, Faculdade de Ciências Médicas de Minas Gerais, Belo Horizonte, 30.130-110, Brazil
| | - David J Paterson
- Burdon Sanderson Cardiac Science Centre, Department of Physiology, Anatomy & Genetics, University of Oxford, Oxford, OX1 3PT, UK
| | - Charles S Redwood
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, OX3 9DU, UK
| | - David Carling
- Cellular Stress Group, MRC London Institute of Medical Sciences, Imperial College London, London, W12 0NN, UK
| | - Catherine Proenza
- Department of Physiology and Biophysics, University of Colorado School of Medicine, Aurora, CO, 80045, USA
| | - Robert David
- Department of Cardiac Surgery, Rostock University Medical Centre, 18057, Rostock, Germany
- Department Life, Light and Matter, Interdisciplinary Faculty, Rostock University, 18059, Rostock, Germany
| | - Mirko Baruscotti
- Department of Biosciences, Università degli Studi di Milano, Milan, 20133, Italy
- Centro Interuniversitario di Medicina Molecolare e Biofisica Applicata, University of Milano, Milan, 20133, Italy
| | - Dario DiFrancesco
- Department of Biosciences, Università degli Studi di Milano, Milan, 20133, Italy
- Centro Interuniversitario di Medicina Molecolare e Biofisica Applicata, University of Milano, Milan, 20133, Italy
| | - Edward G Lakatta
- Laboratory of Cardiovascular Science, Intramural Research Program, National Institute on Aging, NIH, Baltimore, MD, 21224, USA
| | - Hugh Watkins
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, OX3 9DU, UK
- The Wellcome Trust Centre for Human Genetics, Oxford, OX3 7BN, UK
| | - Houman Ashrafian
- Experimental Therapeutics, Radcliffe Department of Medicine, University of Oxford, Oxford, OX3 9DU, UK.
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, OX3 9DU, UK.
- The Wellcome Trust Centre for Human Genetics, Oxford, OX3 7BN, UK.
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19
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Atkinson A, Bucchi A, Piantoni C, Difrancesco D, Baruscotti M, Boyett MR, Dobrzynski H. P1582Molecular basis of cardiac pacemaker ageing in mouse. Europace 2017. [DOI: 10.1093/ehjci/eux158.208] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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20
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Paina M, Piantoni C, Carnevali L, Frosio A, Bucchi A, Barbuti A, Sheng L, Yanyan W, Wang Y, DiFrancesco D, Baruscotti M. A Traditional Chinese Medicine Drug (TMYX) Controls Heart Rate by Modulation of the Pacemaker (F) Channels. Biophys J 2017. [DOI: 10.1016/j.bpj.2016.11.2565] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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21
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Costantino S, Bonzanni M, Legchenko E, Paneni F, Mitchell K, Berrino L, Schwarzwald C, Volpe M, Luscher TF, Cosentino F, Napoli A, Landi S, Bucchi A, Vernillo G, Baruscotti M, La Torre A, Difrancesco D, Barbuti A, Kueffner R, Hansmann G. Epigenetics in Cardiac Health and Disease225miR-218 and mi-R34a drive persistent myocardial oxidative stress by targeting chromatin remodelers DNMT3b and SIRT1: new mechanistic insights in diabetic cardiomyopathy226Effects of miRNAs modulated by endurance training on cardiomyocyte excitability227Differential transcriptome and microRNA expression signatures in the healthy heart (RV vs. LV) and the failing, pressure-overloaded right ventricle (SuHx model). Cardiovasc Res 2016. [DOI: 10.1093/cvr/cvw128] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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22
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Gowran A, Kulikova T, Lewis FC, Foldes G, Fuentes L, Viiri LE, Spinelli V, Costa A, Perbellini F, Sid-Otmane C, Bax NAM, Pekkanen-Mattila M, Schiano C, Chaloupka A, Forini F, Sarkozy M, De Jager SCA, Vajen T, Glezeva N, Lee HW, Golovkin A, Kucera T, Musikhina NA, Korzhenkov NP, Santuchi MDEC, Munteanu D, Garcia RG, Ang R, Usui S, Kamilova U, Jumeau C, Aberg M, Kostina DA, Brandt MM, Muntean D, Lindner D, Sadaba R, Bacova B, Nikolov A, Sedmera D, Ryabov V, Neto FP, Lynch M, Portero V, Kui P, Howarth FC, Gualdoni A, Prorok J, Diolaiuti L, Vostarek F, Wagner M, Abela MA, Nebert C, Xiang W, Kloza M, Maslenko A, Grechanyk M, Bhattachariya A, Morawietz H, Babaeva AR, Martinez Sanchez SM, Krychtiuk KA, Starodubova J, Fiorelli S, Rinne P, Ozkaramanli Gur D, Hofbauer T, Starodubova J, Stellos K, Pinon P, Tsoref O, Thaler B, Fraga-Silva RA, Fuijkschot WW, Shaaban MNS, Matthaeus C, Deluyker D, Scardigli M, Zahradnikova A, Dominguez A, Kondrat'eva D, Sosorburam T, Murarikova M, Duerr GD, Griecsova L, Portnichenko VI, Smolina N, Duicu OANAM, Elder JM, Zaglia T, Lorenzon A, Ruperez C, Woudstra L, Suffee N, De Lucia C, Tsoref O, Russell-Hallinan A, Menendez-Montes I, Kapelko VI, Emmens RW, Hetman O, Van Der Laarse WJ, Goncharov S, Adao R, Huisamen B, Sirenko O, Kamilova U, Nassiri I, Tserendavaa SUMIYA, Yushko K, Baldan Martin M, Falcone C, Vigorelli V, Nigro P, Pompilio G, Stepanova O, Valikhov M, Samko A, Masenko V, Tereschenko S, Teoh T, Domenjo-Vila E, Theologou T, Field M, Awad W, Yasin M, Nadal-Ginard B, Ellison-Hughes GM, Hellen N, Vittay O, Harding SE, Gomez-Cid L, Fernandez-Santos ME, Suarez-Sancho S, Plasencia V, Climent A, Sanz-Ruiz R, Hedhammar M, Atienza F, Fernandez-Aviles F, Kiamehr M, Oittinen M, Viiri KM, Kaikkonen M, Aalto-Setala K, Diolaiuti L, Laurino A, Sartiani L, Vona A, Zanardelli M, Cerbai E, Failli P, Hortigon-Vinagre MP, Van Der Heyden M, Burton FL, Smith GL, Watson S, Scigliano M, Tkach S, Alayoubi S, Harding SE, Terracciano CM, Ly HQ, Mauretti A, Van Marion MH, Van Turnhout MC, Van Der Schaft DWJ, Sahlgren CM, Goumans MJ, Bouten CVC, Vuorenpaa H, Penttinen K, Sarkanen R, Ylikomi T, Heinonen T, Aalto-Setala K, Grimaldi V, Aprile M, Esposito R, Maiello C, Soricelli A, Colantuoni V, Costa V, Ciccodicola A, Napoli C, Rowe GC, Johnson K, Arany ZP, Del Monte F, D'aurizio R, Kusmic C, Nicolini G, Baumgart M, Groth M, Ucciferri N, Iervasi G, Pitto L, Pipicz M, Gaspar R, Siska A, Foldesi I, Kiss K, Bencsik P, Thum T, Batkai S, Csont T, Haan JJ, Bosch L, Brans MAD, Van De Weg SM, Deddens JC, Lee SJ, Sluijter JPG, Pasterkamp G, Werner I, Projahn D, Staudt M, Curaj A, Soenmez TT, Simsekyilmaz S, Hackeng TM, Von Hundelshausen P, Koenen RR, Weber C, Liehn EA, Santos-Martinez M, Medina C, Watson C, Mcdonald K, Gilmer J, Ledwidge M, Song SH, Lee MY, Park MH, Choi JC, Ahn JH, Park JS, Oh JH, Choi JH, Lee HC, Cha KS, Hong TJ, Kudryavtsev I, Serebryakova M, Malashicheva A, Shishkova A, Zhiduleva E, Moiseeva O, Durisova M, Blaha M, Melenovsky V, Pirk J, Kautzner J, Petelina TI, Gapon LI, Gorbatenko EA, Potolinskaya YV, Arkhipova EV, Solodenkova KS, Osadchuk MA, Dutra MF, Oliveira FCB, Silva MM, Passos-Silva DG, Goncalves R, Santos RAS, Da Silva RF, Gavrilescu CM, Paraschiv CM, Manea P, Strat LC, Gomez JMG, Merino D, Hurle MA, Nistal JF, Aires A, Cortajarena AL, Villar AV, Abramowitz J, Birnbaumer L, Gourine AV, Tinker A, Takamura M, Takashima S, Inoue O, Misu H, Takamura T, Kaneko S, Alieva TOHIRA, Mougenot N, Dufilho M, Hatem S, Siegbahn A, Kostina AS, Uspensky VE, Moiseeva OM, Kostareva AA, Malashicheva AB, Van Dijk CGM, Chrifi I, Verhaar MC, Duncker DJ, Cheng C, Sturza A, Petrus A, Duicu O, Kiss L, Danila M, Baczko I, Jost N, Gotzhein F, Schon J, Schwarzl M, Hinrichs S, Blankenberg S, Volker U, Hammer E, Westermann D, Martinez-Martinez E, Arrieta V, Fernandez-Celis A, Jimenez-Alfaro L, Melero A, Alvarez-Asiain V, Cachofeiro V, Lopez-Andres N, Tribulova N, Wallukat G, Knezl V, Radosinska J, Barancik M, Tsinlikov I, Tsinlikova I, Nicoloff G, Blazhev A, Pesevski Z, Kvasilova A, Stopkova T, Eckhardt A, Buffinton CM, Nanka O, Kercheva M, Suslova T, Gusakova A, Ryabova T, Markov V, Karpov R, Seemann H, Alcantara TC, Santuchi MDEC, Fonseca SG, Da Silva RF, Barallobre-Barreiro J, Oklu R, Fava M, Baig F, Yin X, Albadawi H, Jahangiri M, Stoughton J, Mayr M, Podliesna SP, Veerman CCV, Verkerk AOV, Klerk MK, Lodder EML, Mengarelli IM, Bezzina CRB, Remme CAR, Takacs H, Polyak A, Morvay N, Lepran I, Tiszlavicz L, Nagy N, Ordog B, Farkas A, Forster T, Varro A, Farkas AS, Jayaprakash P, Parekh K, Ferdous Z, Oz M, Dobrzynski H, Adrian TE, Landi S, Bonzanni M, D'souza A, Boyett M, Bucchi A, Baruscotti M, Difrancesco D, Barbuti A, Kui P, Takacs H, Oravecz K, Hezso T, Polyak A, Levijoki J, Pollesello P, Koskelainen T, Otsomaa L, Farkas AS, Papp JGY, Varro A, Toth A, Acsai K, Dini L, Mazzoni L, Sartiani L, Cerbai E, Mugelli A, Svatunkova J, Sedmera D, Deffge C, Baer C, Weinert S, Braun-Dullaeus RC, Herold J, Cassar AC, Zahra GZ, Pllaha EP, Dingli PD, Montefort SM, Xuereb RGX, Aschacher T, Messner B, Eichmair E, Mohl W, Reglin B, Rong W, Nitzsche B, Maibier M, Guimaraes P, Ruggeri A, Secomb TW, Pries AR, Baranowska-Kuczko M, Karpinska O, Kusaczuk M, Malinowska B, Kozlowska H, Demikhova N, Vynnychenko L, Prykhodko O, Grechanyk N, Kuryata A, Cottrill KA, Du L, Bjorck HM, Maleki S, Franco-Cereceda A, Chan SY, Eriksson P, Giebe S, Cockcroft N, Hewitt K, Brux M, Brunssen C, Tarasov AA, Davidov SI, Reznikova EA, Tapia Abellan A, Angosto Bazarra D, Pelegrin Vivancos P, Montoro Garcia S, Kastl SP, Pongratz T, Goliasch G, Gaspar L, Maurer G, Huber K, Dostal E, Pfaffenberger S, Oravec S, Wojta J, Speidl WS, Osipova I, Sopotova I, Eligini S, Cosentino N, Marenzi G, Tremoli E, Rami M, Ring L, Steffens S, Gur O, Gurkan S, Mangold A, Scherz T, Panzenboeck A, Staier N, Heidari H, Mueller J, Lang IM, Osipova I, Sopotova I, Gatsiou A, Stamatelopoulos K, Perisic L, John D, Lunella FF, Eriksson P, Hedin U, Zeiher A, Dimmeler S, Nunez L, Moure R, Marron-Linares G, Flores X, Aldama G, Salgado J, Calvino R, Tomas M, Bou G, Vazquez N, Hermida-Prieto M, Vazquez-Rodriguez JM, Amit U, Landa N, Kain D, Tyomkin D, David A, Leor J, Hohensinner PJ, Baumgartner J, Krychtiuk KA, Maurer G, Huber K, Baik N, Miles LA, Wojta J, Seeman H, Montecucco F, Da Silva AR, Costa-Fraga FP, Anguenot L, Mach FP, Santos RAS, Stergiopulos N, Da Silva RF, Kupreishvili K, Vonk ABA, Smulders YM, Van Hinsbergh VWM, Stooker W, Niessen HWM, Krijnen PAJ, Ashmawy MM, Salama MA, Elamrosy MZ, Juettner R, Rathjen FG, Bito V, Crocini C, Ferrantini C, Gabbrielli T, Silvestri L, Coppini R, Tesi C, Cerbai E, Poggesi C, Pavone FS, Sacconi L, Mackova K, Zahradnik I, Zahradnikova A, Diaz I, Sanchez De Rojas De Pedro E, Hmadcha K, Calderon Sanchez E, Benitah JP, Gomez AM, Smani T, Ordonez A, Afanasiev SA, Egorova MV, Popov SV, Wu Qing P, Cheng X, Carnicka S, Pancza D, Jasova M, Kancirova I, Ferko M, Ravingerova T, Wu S, Schneider M, Marggraf V, Verfuerth L, Frede S, Boehm O, Dewald O, Baumgarten G, Kim SC, Farkasova V, Gablovsky I, Bernatova I, Ravingerova T, Nosar V, Portnychenko A, Drevytska T, Mankovska I, Gogvadze V, Sejersen T, Kostareva A, Sturza A, Wolf A, Privistirescu A, Danila M, Muntean D, O ' Gara P, Sanchez-Alonso JL, Harding SE, Lyon AR, Prando V, Pianca N, Lo Verso F, Milan G, Pesce P, Sandri M, Mongillo M, Beffagna G, Poloni G, Dazzo E, Sabatelli P, Doliana R, Polishchuk R, Carnevale D, Lembo G, Bonaldo P, Braghetta P, Rampazzo A, Cairo M, Giralt M, Villarroya F, Planavila A, Biesbroek PS, Emmens RWE, Juffermans LJM, Van Der Wall AC, Van Rossum AC, Niessen JWM, Krijnen PAJ, Moor Morris T, Dilanian G, Farahmand P, Puceat M, Hatem S, Gambino G, Petraglia L, Elia A, Komici K, Femminella GD, D'amico ML, Pagano G, Cannavo A, Liccardo D, Koch WJ, Nolano M, Leosco D, Ferrara N, Rengo G, Amit U, Landa N, Kain D, Leor J, Neary R, Shiels L, Watson C, Baugh J, Palacios B, Escobar B, Alonso AV, Guzman G, Ruiz-Cabello J, Jimenez-Borreguero LJ, Martin-Puig S, Lakomkin VL, Lukoshkova EV, Abramov AA, Gramovich VV, Vyborov ON, Ermishkin VV, Undrovinas NA, Shirinsky VP, Smilde BJ, Woudstra L, Fong Hing G, Wouters D, Zeerleder S, Murk JL, Van Ham SM, Heymans S, Juffermans LJM, Van Rossum AC, Niessen JWM, Krijnen PAJ, Krakhmalova O, Van Groen D, Bogaards SJP, Schalij I, Portnichenko GV, Tumanovska LV, Goshovska YV, Lapikova-Bryhinska TU, Nagibin VS, Dosenko VE, Mendes-Ferreira P, Maia-Rocha C, Santos-Ribeiro D, Potus F, Breuils-Bonnet S, Provencher S, Bonnet S, Rademaker M, Leite-Moreira AF, Bras-Silva C, Lopes J, Kuryata O, Lusynets T, Alikulov I, Nourddine M, Azzouzi L, Habbal R, Tserendavaa SUMIYA, Enkhtaivan ODKHUU, Enkhtaivan ODKHUU, Shagdar ZORIGO, Shagdar ZORIGO, Malchinkhuu MUNKHZ, Malchinkhuu MUNLHZ, Koval S, Starchenko T, Mourino-Alvarez L, Gonzalez-Calero L, Sastre-Oliva T, Lopez JA, Vazquez J, Alvarez-Llamas G, Ruilope LUISM, De La Cuesta F, Barderas MG, Bozzini S, D'angelo A, Pelissero G. Poster session 3Cell growth, differentiation and stem cells - Heart511The role of the endocannabinoid system in modelling muscular dystrophy cardiac disease with induced pluripotent stem cells.512An emerging role of T lymphocytes in cardiac regenerative processes in heart failure due to dilated cardiomyopathy513Canonical wnt signaling reverses the ‘aged/senescent’ human endogenous cardiac stem cell phenotype514Hippo signalling modulates survival of human induced pluripotent stem cell-derived cardiomyocytes515Biocompatibility of mesenchymal stem cells with a spider silk matrix and its potential use as scaffold for cardiac tissue regeneration516A snapshot of genome-wide transcription in human induced pluripotent stem cell-derived hepatocyte-like cells (iPSC-HLCs)517Can NOS/sGC/cGK1 pathway trigger the differentiation and maturation of mouse embryonic stem cells (ESCs)?518Introduction of external Ik1 to human-induced pluripotent stem cell-derived cardiomyocytes via Ik1-expressing HEK293519Cell therapy of the heart studied using adult myocardial slices in vitro520Enhancement of the paracrine potential of human adipose derived stem cells when cultured as spheroid bodies521Mechanosensitivity of cardiomyocyte progenitor cells: the strain response in 2D and 3D environments522The effect of the vascular-like network on the maturation of the human induced pluripotent stem cell derived cardiomyocytes.Transcriptional control and RNA species - Heart525Gene expression regulation in heart failure: from pathobiology to bioinformatics526Human transcriptome in idiopathic dilated cardiomyopathy - a novel high throughput screening527A high-throghput approach unveils putative miRNA-mediated mitochondria-targeted cardioprotective circuits activated by T3 in the post ischemia reperfusion setting528The effect of uraemia on the expression of miR-212/132 and the calcineurin pathway in the rat heartCytokines and cellular inflammation - Heart531Lack of growth differentiation factor 15 aggravates adverse cardiac remodeling upon pressure-overload in mice532Blocking heteromerization of platelet chemokines ccl5 and cxcl4 reduces inflammation and preserves heart function after myocardial infarction533Is there an association between low-dose aspirin use and clinical outcome in HFPEF? Implications of modulating monocyte function and inflammatory mediator release534N-terminal truncated intracellular matrix metalloproteinase-2 expression in diabetic heart.535Expression of CD39 and CD73 on peripheral T-cell subsets in calcific aortic stenosis536Mast cells in the atrial myocardium of patients with atrial fibrillation: a comparison with patients in sinus rhythm539Characteristics of the inflammatory response in patients with coronary artery disease and arterial hypertension540Pro-inflammatory cytokines as cardiovascular events predictors in rheumatoid arthritis and asymptomatic atherosclerosis541Characterization of FVB/N murinic bone marrow-derived macrophage polarization into M1 and M2 phenotypes542The biological expression and thoracic anterior pain syndromeSignal transduction - Heart545The association of heat shock protein 90 and TGFbeta receptor I is involved in collagen production during cardiac remodelling in aortic-banded mice546Loss of the inhibitory GalphaO protein in the rostral ventrolateral medulla of the brainstem leads to abnormalities in cardiovascular reflexes and altered ventricular excitablitiy547Selenoprotein P regulates pressure overload-induced cardiac remodeling548Study of adenylyl cyclase activity in erythrocyte membranes in patients with chronic heart failure549Direct thrombin inhibitors inhibit atrial myocardium hypertrophy in a rat model of heart failure and atrial remodeling550Tissue factor / FVIIa transactivates the IGF-1R by a Src-dependent phosphorylation of caveolin-1551Notch signaling is differently altered in endothelial and smooth muscle cells of ascending aortic aneurysm patients552Frizzled 5 expression is essential for endothelial proliferation and migration553Modulation of vascular function and ROS production by novel synthetic benzopyran analogues in diabetes mellitusExtracellular matrix and fibrosis - Heart556Cardiac fibroblasts as inflammatory supporter cells trigger cardiac inflammation in heart failure557A role for galectin-3 in calcific aortic valve stenosis558Omega-3 polyunsaturated fatty acids- can they decrease risk for ventricular fibrillation?559Serum levels of elastin derived peptides and circulating elastin-antielastin immune complexes in sera of patients with coronary artery disease560Endocardial fibroelastosis is secondary to hemodynamic alterations in the chick model of hypoplastic left heart syndrome561Dynamics of serum levels of matrix metalloproteinases in primary anterior STEMI patients564Deletion of the alpha-7 nicotinic acetylcholine receptor changes the vascular remodeling induced by transverse aortic constriction in mice.565Extracellular matrix remodelling in response to venous hypertension: proteomics of human varicose veinsIon channels, ion exchangers and cellular electrophysiology - Heart568Microtubule-associated protein RP/EB family member 1 modulates sodium channel trafficking and cardiac conduction569Investigation of electrophysiological abnormalities in a rabbit athlete's heart model570Upregulation of expression of multiple genes in the atrioventricular node of streptozotocin-induced diabetic rat571miR-1 as a regulator of sinoatrial rhythm in endurance training adaptation572Selective sodium-calcium exchanger inhibition reduces myocardial dysfunction associated with hypokalaemia and ventricular fibrillation573Effect of racemic and levo-methadone on action potential of human ventricular cardiomyocytes574Acute temperature effects on the chick embryonic heart functionVasculogenesis, angiogenesis and arteriogenesis577Clinical improvement and enhanced collateral vessel growth after monocyte transplantation in mice578The role of HIF-1 alpha, VEGF and obstructive sleep apnoea in the development of coronary collateral circulation579Initiating cardiac repair with a trans-coronary sinus catheter intervention in an ischemia/reperfusion porcine animal model580Early adaptation of pre-existing collaterals after acute arteriolar and venular microocclusion: an in vivo study in chick chorioallantoic membraneEndothelium583EDH-type responses to the activator of potassium KCa2.3 and KCa3.1 channels SKA-31 in the small mesenteric artery from spontaneously hypertensive rats584The peculiarities of endothelial dysfunction in patients with chronic renocardial syndrome585Endothelial dysfunction, atherosclerosis of the carotid arteries and level of leptin in patient with coronary heart disease in combination with hepatic steatosis depend from body mass index.586Role of non-coding RNAs in thoracic aortic aneurysm associated with bicuspid aortic valve587Cigarette smoke extract abrogates atheroprotective effects of high laminar flow on endothelial function588The prognostic value of anti-connective tissue antibodies in coronary heart disease and asymptomatic atherosclerosis589Novel potential properties of bioactive peptides from spanish dry-cured ham on the endothelium.Lipids592Intermediate density lipoprotein is associated with monocyte subset distribution in patients with stable atherosclerosis593The characteristics of dyslipidemia in rheumatoid arthritisAtherosclerosis596Macrophages differentiated in vitro are heterogeneous: morphological and functional profile in patients with coronary artery disease597Palmitoylethanolamide promotes anti-inflammatory phenotype of macrophages and attenuates plaque formation in ApoE-/- mice598Amiodarone versus esmolol in the perioperative period: an in vitro study of coronary artery bypass grafts599BMPRII signaling of fibrocytes, a mesenchymal progenitor cell population, is increased in STEMI and dyslipidemia600The characteristics of atherogenesis and systemic inflammation in rheumatoid arthritis601Role of adenosine-to-inosine RNA editing in human atherosclerosis602Presence of bacterial DNA in thrombus aspirates of patients with myocardial infarction603Novel E-selectin binding polymers reduce atherosclerotic lesions in ApoE(-/-) mice604Differential expression of the plasminogen receptor Plg-RKT in monocyte and macrophage subsets - possible functional consequences in atherogenesis605Apelin-13 treatment enhances the stability of atherosclerotic plaques606Mast cells are increased in the media of coronary lesions in patients with myocardial infarction and favor atherosclerotic plaque instability607Association of neutrophil to lymphocyte ratio with presence of isolated coronary artery ectasiaCalcium fluxes and excitation-contraction coupling610The coxsackie- and adenovirus receptor (CAR) regulates calcium homeostasis in the developing heart611HMW-AGEs application acutely reduces ICaL in adult cardiomyocytes612Measuring electrical conductibility of cardiac T-tubular systems613Postnatal development of cardiac excitation-contraction coupling in rats614Role of altered Ca2+ homeostasis during adverse cardiac remodeling after ischemia/reperfusion615Experimental study of sarcoplasmic reticulum dysfunction and energetic metabolism in failing myocardium associated with diabetes mellitusHibernation, stunning and preconditioning618Volatile anesthetic preconditioning attenuates ischemic-reperfusion injury in type II diabetic patients undergoing on-pump heart surgery619The effect of early and delayed phase of remote ischemic preconditioning on ischemia-reperfusion injury in the isolated hearts of healthy and diabetic rats620Post-conditioning with 1668-thioate leads to attenuation of the inflammatory response and remodeling with less fibrosis and better left ventricular function in a murine model of myocardial infarction621Maturation-related changes in response to ischemia-reperfusion injury and in effects of classical ischemic preconditioning and remote preconditioningMitochondria and energetics624Phase changes in myocardial mitochondrial respiration caused by hypoxic preconditioning or periodic hypoxic training625Desmin mutations depress mitochondrial metabolism626Methylene blue modulates mitochondrial function and monoamine oxidases-related ROS production in diabetic rat hearts627Doxorubicin modulates the real-time oxygen consumption rate of freshly isolated adult rat and human ventricular cardiomyocytesCardiomyopathies and fibrosis630Effects of genetic or pharmacologic inhibition of the ubiquitin/proteasome system on myocardial proteostasis and cardiac function631Suppression of Wnt signalling in a desmoglein-2 transgenic mouse model for arrhythmogenic cardiomyopathy632Cold-induced cardiac hypertrophy is reversed after thermo-neutral deacclimatization633CD45 is a sensitive marker to diagnose lymphocytic myocarditis in endomyocardial biopsies of living patients and in autopsies634Atrial epicardial adipose tissue derives from epicardial progenitors635Caloric restriction ameliorates cardiac function, sympathetic cardiac innervation and beta-adrenergic receptor signaling in an experimental model of post-ischemic heart failure636High fat diet improves cardiac remodelling and function after extensive myocardial infarction in mice637Epigenetic therapy reduces cardiac hypertrophy in murine models of heart failure638Imbalance of the VHL/HIF signaling in WT1+ Epicardial Progenitors results in coronary vascular defects, fibrosis and cardiac hypertrophy639Diastolic dysfunction is the first stage of the developing heart failure640Colchicine aggravates coxsackievirus B3 infection in miceArterial and pulmonary hypertension642Osteopontin as a marker of pulmonary hypertension in patients with coronary heart disease combined with chronic obstructive pulmonary disease643Myocardial dynamic stiffness is increased in experimental pulmonary hypertension partly due to incomplete relaxation644Hypotensive effect of quercetin is possibly mediated by down-regulation of immunotroteasome subunits in aorta of spontaneously hypertensive rats645Urocortin-2 improves right ventricular function and attenuates experimental pulmonary arterial hypertension646A preclinical evaluation of the anti-hypertensive properties of an aqueous extract of Agathosma (Buchu)Biomarkers648The adiponectin level in hypertensive females with rheumatoid arthritis and its relationship with subclinical atherosclerosis649Markers for identification of renal dysfunction in the patients with chronic heart failure650cardio-hepatic syndromes in chronic heart failure: North Africa profile651To study other biomarkers that assess during myocardial infarction652Interconnections of apelin levels with parameters of lipid metabolism in hypertension patients653Plasma proteomics in hypertension: prediction and follow-up of albuminuria during chronic renin-angiotensin system suppression654Soluble RAGE levels in plasma of patients with cerebrovascular events. Cardiovasc Res 2016. [DOI: 10.1093/cvr/cvw150] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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Andre E, Yaniz-Galende E, Hamilton C, Dusting GJ, Hellen N, Poulet CE, Diez Cunado M, Smits AM, Lowe V, Eckardt D, Du Pre B, Sanz Ruiz R, Moerkamp AT, Tribulova N, Smani T, Liskova YV, Greco S, Guzzolino E, Franco D, Lozano-Velasco E, Knorr M, Pavoine C, Bukowska A, Van Linthout S, Miteva K, Sulzgruber P, Latet SC, Portnychenko A, Cannavo A, Kamilova U, Sagach VF, Santin Y, Octavia Y, Haller PM, Octavia Y, Rubies C, Dei Zotti F, Wong KHK, Gonzalez Miqueo A, Kruithof BPT, Kadur Nagaraju C, Shaposhnikova Y, Songia P, Lindner D, Wilson C, Benzoni P, Fabbri A, Campostrini G, Jorge E, Casini S, Mengarelli I, Nikolov A, Bublikov DS, Kheloufi M, Rubies C, Walker RE, Van Dijk RA, Posthuma JJ, Dumitriu IE, Karshovska E, Sakic A, Alexandru N, Martin-Lorenzo M, Molica F, Taylor RF, Mcarthur L, Crocini C, Matsuyama TA, Mazzoni L, Lin WK, Owen TJ, Scigliano M, Sheehan A, Bezerra Gurgel AR, Bromage DI, Kiss A, Ikeda G, Pickard JMJ, Wirth G, Casos K, Khudiakov A, Nistal JF, Ferrantini C, Park SJ, Di Maggio S, Gentile F, Dini L, Buyandelger B, Larrasa-Alonso J, Schirmer I, Chin SH, Cimiotti D, Martini H, Hohensinner PJ, Garabito M, Zeni F, Licholai S, De Bortoli M, Sivitskaya L, Viczenczova C, Rainer PP, Smith LE, Suna G, Gambardella J, Cozma A, De Gonzalo Calvo D, Scoditti E, Clark BJ, Mansfield C, Eckardt D, Gomez L, Llucia-Valldeperas A, De Pauw A, Porporato P, Bouzin C, Draoui N, Sonveaux P, Balligand JL, Mougenot N, Formicola L, Nadaud S, Dierick F, Hajjar RJ, Marazzi G, Sassoon D, Hulot JS, Zamora VR, Burton FL, Macquaide N, Smith GL, Hernandez D, Sivakumaran P, Millard R, Wong RCB, Pebay A, Shepherd RK, Lim SY, Owen T, Jabbour RJ, Kloc M, Kodagoda T, Denning C, Harding SE, Ramos S, Terracciano C, Gorelik J, Wei K, Bushway P, Ruiz-Lozano P, Mercola M, Moerkamp AT, Vegh AMD, Dronkers E, Lodder K, Van Herwaarden T, Goumans MJ, Pellet-Many C, Zachary I, Noack K, Bosio A, Feyen DAM, Demkes EJ, Dierickx PJ, Doevendans PA, Vos MA, Van Veen AAB, Van Laake LW, Fernandez Santos ME, Suarez Sancho S, Fuentes Arroyo L, Plasencia Martin V, Velasco Sevillano P, Casado Plasencia A, Climent AM, Guillem M, Atienza Fernandez F, Fernandez-Aviles F, Dingenouts CKE, Lodder K, Kruithof BPT, Van Herwaarden T, Vegh AMD, Goumans MJ, Smits AM, Knezl V, Szeiffova Bacova B, Egan Benova T, Viczenczova C, Goncalvesova E, Slezak J, Calderon-Sanchez E, Diaz I, Ordonez A, Salikova SP, Zaccagnini G, Voellenkle C, Sadeghi I, Maimone B, Castelvecchio S, Gaetano C, Menicanti L, Martelli F, Hatcher C, D'aurizio R, Groth M, Baugmart M, Mercatanti A, Russo F, Mariani L, Magliaro C, Pitto L, Lozano-Velasco E, Jodar-Garcia A, Galiano-Torres J, Lopez-Navarrete I, Aranega A, Wagensteen R, Quesada A, Aranega A, Franco D, Finger S, Karbach S, Kossmann S, Muenzel T, Wenzel P, Keck M, Mougenot N, Favier S, Fuand A, Atassi F, Barbier C, Lompre AM, Hulot JS, Nikonova Y, Pluteanu F, Kockskaemper J, Chilukoti RK, Wolke C, Lendeckel U, Gardemann A, Goette A, Miteva K, Pappritz K, Mueller I, El-Shafeey M, Ringe J, Tschoepe C, Pappritz K, El-Shafeey M, Ringe J, Tschoepe C, Van Linthout S, Koller L, Richter B, Blum S, Koprak M, Huelsmann M, Pacher R, Goliasch G, Wojta J, Niessner A, Van Herck PL, Claeys MJ, Haine SE, Lenders GD, Miljoen HP, Segers VF, Vandendriescche TR, Hoymans VY, Vrints CJ, Lapikova-Bryhinska T, Gurianova V, Portnichenko H, Vasylenko M, Zapara Y, Portnichenko V, Liccardo D, Lymperopoulos A, Santangelo M, Leosco D, Koch WJ, Ferrara N, Rengo G, Alieva T, Rasulova Z, Masharipova D, Dorofeyeva NA, Drachuk KO, Sicard P, Yucel Y, Dutaur M, Vindis C, Parini A, Mialet-Perez J, Van Deel ED, De Boer M, De Waard MC, Duncker DJ, Nagel F, Inci M, Santer D, Hallstroem S, Podesser BK, Kararigas G, De Boer M, Kietadisorn R, Swinnen M, Duimel H, Verheyen F, Chrifi I, Brandt MM, Cheng C, Janssens S, Moens AL, Duncker DJ, Batlle M, Dantas AP, Sanz M, Sitges M, Mont L, Guasch E, Lobysheva I, Beauloye C, Balligand JL, Vanhoutte PM, Tang EHC, Beaumont J, Lopez B, Ravassa S, Hermida N, Valencia F, Gomez-Doblas JJ, San Jose G, De Teresa E, Diez J, Van De Merbel AF, Kruithof-De Julio M, Goumans MJ, Claus P, Dries E, Angelo Singh A, Vermeulen K, Roderick HL, Sipido KR, Driesen RB, Ilchenko I, Bobronnikova L, Myasoedova V, Alamanni F, Tremoli E, Poggio P, Becher PM, Gotzhein F, Klingel K, Blankenberg S, Westermann D, Zi M, Cartwright E, Campostrini G, Bonzanni M, Milanesi R, Bucchi A, Baruscotti M, Difrancesco D, Barbuti A, Fantini M, Wilders R, Severi S, Benzoni P, Dell' Era P, Serzanti M, Olesen MS, Muneretto C, Bisleri G, Difrancesco D, Baruscotti M, Bucchi A, Barbuti A, Amoros-Figueras G, Raga S, Campos B, Alonso-Martin C, Rodriguez-Font E, Vinolas X, Cinca J, Guerra JM, Mengarelli I, Schumacher CA, Veldkamp MW, Verkerk AO, Remme CA, Veerman C, Guan K, Stauske M, Tan H, Barc J, Wilde A, Verkerk A, Bezzina C, Tsinlikov I, Tsinlikova I, Nicoloff G, Blazhev A, Garev A, Andrienko AV, Lychev VG, Vorobova EN, Anchugina DA, Vion AC, Hammoutene A, Poisson J, Dupont N, Souyri M, Tedgui A, Codogno P, Boulanger CM, Rautou PE, Dantas AP, Batlle M, Guasch E, Torres M, Montserrat JM, Almendros I, Mont L, Austin CA, Holt CM, Rijs K, Wezel A, Hamming JF, Kolodgie FD, Virmani R, Schaapherder AF, Lindeman JHN, Posma JJN, Van Oerle R, Spronk HMH, Ten Cate H, Dinkla S, Kaski JC, Schober A, Chaabane C, Ambartsumian N, Grigorian M, Bochaton-Piallat ML, Dragan E, Andrei E, Niculescu L, Georgescu A, Gonzalez-Calero L, Maroto AS, Martinez PJ, Heredero A, Aldamiz-Echevarria G, Vivanco F, Alvarez-Llamas G, Meens MJ, Pelli G, Foglia B, Scemes E, Kwak BR, Caldwell JL, Eisner DA, Dibb KM, Trafford AW, Chilton L, Smith GL, Nicklin SA, Coppini R, Ferrantini C, Yan P, Loew LM, Poggesi C, Cerbai E, Pavone FS, Sacconi L, Tanaka H, Ishibashi-Ueda H, Takamatsu T, Coppini R, Ferrantini C, Gentile F, Pioner JM, Santini L, Sartiani L, Bargelli V, Poggesi C, Mugelli A, Cerbai E, Maciejewska M, Bolton EL, Wang Y, O'brien F, Ruas M, Lei M, Sitsapesan R, Galione A, Terrar DA, Smith JG, Garcia D, Barriales-Villa R, Monserrat L, Harding SE, Denning C, Marston SB, Watson S, Tkach S, Faggian G, Terracciano CM, Perbellini F, Eiros Zamora J, Papadaki M, Messer A, Marston S, Gould I, Johnston A, Dunne M, Smith G, Kemi OJ, Pillai M, Davidson SM, Yellon DM, Tratsiakovich Y, Jang J, Gonon AT, Pernow J, Matoba T, Koga J, Egashira K, Burke N, Davidson SM, Yellon DM, Korpisalo P, Hakkarainen H, Laidinen S, Yla-Herttuala S, Ferrer-Curriu G, Perez M, Permanyer E, Blasco-Lucas A, Gracia JM, Castro MA, Barquinero J, Galinanes M, Kostina D, Kostareva A, Malashicheva A, Merino D, Ruiz L, Gomez J, Juarez C, Gil A, Garcia R, Hurle MA, Coppini R, Pioner JM, Gentile F, Mazzoni L, Rossi A, Tesi C, Belardinelli L, Olivotto I, Cerbai E, Mugelli A, Poggesi C, Eun-Ji EJ, Lim BK, Choi DJ, Milano G, Bertolotti M, De Marchis F, Zollo F, Sommariva E, Capogrossi MC, Pompilio G, Bianchi ME, Raucci A, Pioner JM, Coppini R, Scellini B, Tardiff J, Tesi C, Poggesi C, Ferrantini C, Mazzoni L, Sartiani L, Coppini R, Diolaiuti L, Ferrari P, Cerbai E, Mugelli A, Mansfield C, Luther P, Knoell R, Villalba M, Sanchez-Cabo F, Lopez-Olaneta MM, Ortiz-Sanchez P, Garcia-Pavia P, Lara-Pezzi E, Klauke B, Gerdes D, Schulz U, Gummert J, Milting H, Wake E, Kocsis-Fodor G, Brack KE, Ng GA, Kostareva A, Smolina N, Majchrzak M, Moehner D, Wies A, Milting H, Stehle R, Pfitzer G, Muegge A, Jaquet K, Maggiorani D, Lefevre L, Dutaur M, Mialet-Perez J, Parini A, Cussac D, Douin-Echinard V, Ebenbauer B, Kaun C, Prager M, Wojta J, Rega-Kaun G, Costa G, Onetti Y, Jimenez-Altayo F, Vila E, Dantas AP, Milano G, Bertolotti M, Scopece A, Piacentini L, Bianchi ME, Capogrossi MC, Pompilio G, Colombo G, Raucci A, Blaz M, Kapelak B, Sanak M, Bauce B, Calore C, Lorenzon A, Calore M, Poloni G, Mazzotti E, Rigato I, Daliento L, Basso C, Thiene G, Melacini P, Corrado D, Rampazzo A, Danilenko NG, Vaikhanskaya TG, Davydenko OG, Szeiffova Bacova B, Kura B, Egan Benova T, Yin CH, Kukreja R, Slezak J, Tribulova N, Lee DI, Sorge M, Glabe C, Paolocci N, Guarnieri C, Tomaselli GF, Kass DA, Van Eyk JE, Agnetti G, Cordwell SJ, White MY, Wojakowski W, Lynch M, Barallobre-Barreiro J, Yin X, Mayr U, White S, Jahingiri M, Hill J, Mayr M, Sorriento D, Ciccarelli M, Fiordelisi A, Campiglia P, Trimarco B, Iaccarino G, Sitar Taut AV, Schiau S, Orasan O, Halloumi W, Negrean V, Zdrenghea D, Pop D, Van Der Meer RW, Rijzewijk LJ, Smit JWA, Revuelta-Lopez E, Nasarre L, Escola-Gil JC, Lamb HJ, Llorente-Cortes V, Pellegrino M, Massaro M, Carluccio MA, Calabriso N, Wabitsch M, Storelli C, De Caterina R, Church SJ, Callagy S, Begley P, Kureishy N, Mcharg S, Bishop PN, Unwin RD, Cooper GJS, Mawad D, Perbellini F, Tonkin J, Bello SO, Simonotto JD, Lyon AR, Stevens MM, Terracciano CM, Harding SE, Kernbach M, Czichowski V, Bosio A, Fuentes L, Hernandez-Redondo I, Guillem MS, Fernandez ME, Sanz R, Atienza F, Climent AM, Fernandez-Aviles F, Soler-Botija C, Prat-Vidal C, Galvez-Monton C, Roura S, Perea-Gil I, Bragos R, Bayes-Genis A. Poster session 1Cell growth, differentiation and stem cells - Heart72Understanding the metabolism of cardiac progenitor cells: a first step towards controlling their proliferation and differentiation?73Expression of pw1/peg3 identifies a new cardiac adult stem cell population involved in post-myocardial infarction remodeling74Long-term stimulation of iPS-derived cardiomyocytes using optogenetic techniques to promote phenotypic changes in E-C coupling75Benefits of electrical stimulation on differentiation and maturation of cardiomyocytes from human induced pluripotent stem cells76Constitutive beta-adrenoceptor-mediated cAMP production controls spontaneous automaticity of human induced pluripotent stem cell-derived cardiomyocytes77Formation and stability of T-tubules in cardiomyocytes78Identification of miRNAs promoting human cardiomyocyte proliferation by regulating Hippo pathway79A direct comparison of foetal to adult epicardial cell activation reveals distinct differences relevant for the post-injury response80Role of neuropilins in zebrafish heart regeneration81Highly efficient immunomagnetic purification of cardiomyocytes derived from human pluripotent stem cells82Cardiac progenitor cells posses a molecular circadian clock and display large 24-hour oscillations in proliferation and stress tolerance83Influence of sirolimus and everolimus on bone marrow-derived mesenchymal stem cell biology84Endoglin is important for epicardial behaviour following cardiac injuryCell death and apoptosis - Heart87Ultrastructural alterations reflecting Ca2+ handling and cell-to-cell coupling disorders precede occurrence of severe arrhythmias in intact animal heart88Urocortin-1 promotes cardioprotection through ERK1/2 and EPAC pathways: role in apoptosis and necrosis89Expression p38 MAPK and Cas-3 in myocardium LV of rats with experimental heart failure at melatonin and enalapril introductionTranscriptional control and RNA species - Heart92Accumulation of beta-amyloid 1-40 in HF patients: the role of lncRNA BACE1-AS93Role of miR-182 in zebrafish and mouse models of Holt-Oram syndrome94Mir-27 distinctly regulates muscle-enriched transcription factors and growth factors in cardiac and skeletal muscle cells95AF risk factors impair PITX2 expression leading to Wnt-microRNA-ion channel remodelingCytokines and cellular inflammation - Heart98Post-infarct survival depends on the interplay of monocytes, neutrophils and interferon gamma in a mouse model of myocardial Infarction99Inflammatory cd11b/c cells play a protective role in compensated cardiac hypertrophy by promoting an orai3-related pro-survival signal100Anti-inflammatory effects of endothelin receptor blockade in the atrial tissue of spontaneously hypertensive rats101Mesenchymal stromal cells reduce NLRP3 inflammasome activity in Coxsackievirus B3-induced myocarditis102Mesenchymal stromal cells modulate monocytes trafficking in Coxsackievirus B3-induced myocarditis103The impact of regulatory T lymphocytes on long-term mortality in patients with chronic heart failure104Temporal dynamics of dendritic cells after ST-elevation myocardial infarction relate with improvement of myocardial functionGrowth factors and neurohormones - Heart107Preconditioning of hypertrophied heart: miR-1 and IGF-1 crosstalk108Modulation of catecholamine secretion from human adrenal chromaffin cells by manipulation of G protein-coupled receptor kinase-2 activity109Evaluation of cyclic adenosin-3,5- monophosphate and neurohormones in patients with chronic heart failureNitric oxide and reactive oxygen species - Heart112Hydrogen sulfide donor inhibits oxidative and nitrosative stress, cardiohemodynamics disturbances and restores cNOS coupling in old rats113Role and mechanisms of action of aldehydes produced by monoamine oxidase A in cardiomyocyte death and heart failure114Exercise training has contrasting effects in myocardial infarction and pressure-overload due to different endothelial nitric oxide synthase regulation115S-Nitroso Human Serum Albumin dose-dependently leads to vasodilation and alters reactive hyperaemia in coronary arteries of an isolated mouse heart model116Modulating endothelial nitric oxide synthase with folic acid attenuates doxorubicin-induced cardiomyopathy119Effects of long-term very high intensity exercise on aortic structure and function in an animal model120Electron paramagnetic resonance spectroscopy quantification of nitrosylated hemoglobin (HbNO) as an index of vascular nitric oxide bioavailability in vivo121Deletion of repressor activator protein 1 impairs acetylcholine-induced relaxation due to production of reactive oxygen speciesExtracellular matrix and fibrosis - Heart124MicroRNA-19b is associated with myocardial collagen cross-linking in patients with severe aortic stenosis. Potential usefulness as a circulating biomarker125A new ex vivo model to study cardiac fibrosis126Heterogeneity of fibrosis and fibroblast differentiation in the left ventricle after myocardial infarction127Effect of carbohydrate metabolism degree compensation to the level of galectin-3 changes in hypertensive patients with chronic heart failure and type 2 diabetes mellitus128Statin paradox in association with calcification of bicuspid aortic valve interstitial cells129Cardiac function remains impaired despite reversible cardiac fibrosis after healed experimental viral myocarditisIon channels, ion exchangers and cellular electrophysiology - Heart132Identifying a novel role for PMCA1 (Atp2b1) in heart rhythm instability133Mutations of the caveolin-3 gene as a predisposing factor for cardiac arrhythmias134The human sinoatrial node action potential: time for a computational model135iPSC-derived cardiomyocytes as a model to dissect ion current alterations of genetic atrial fibrillation136Postextrasystolic potentiation in healthy and diseased hearts: effects of the site of origin and coupling interval of the preceding extrasystole137Absence of Nav1.8-based (late) sodium current in rabbit cardiomyocytes and human iPSC-CMs138hiPSC-derived cardiomyocytes from Brugada Syndrome patients without identified mutations do not exhibit cellular electrophysiological abnormalitiesMicrocirculation141Atherogenic indices, collagen type IV turnover and the development of microvascular complications- study in diabetics with arterial hypertension142Changes in the microvasculature and blood viscosity in women with rheumatoid arthritis, hypercholesterolemia and hypertensionAtherosclerosis145Shear stress regulates endothelial autophagy: consequences on endothelial senescence and atherogenesis146Obstructive sleep apnea causes aortic remodeling in a chronic murine model147Aortic perivascular adipose tissue displays an aged phenotype in early and late atherosclerosis in ApoE-/- mice148A systematic evaluation of the cellular innate immune response during the process of human atherosclerosis149Inhibition of Coagulation factor Xa increases plaque stability and attenuates the onset and progression of atherosclerotic plaque in apolipoprotein e-deficient mice150Regulatory CD4+ T cells from patients with atherosclerosis display pro-inflammatory skewing and enhanced suppression function151Hypoxia-inducible factor (HIF)-1alpha regulates macrophage energy metabolism by mediating miRNAs152Extracellular S100A4 is a key player of smooth muscle cell phenotypic transition: implications in atherosclerosis153Microparticles of healthy origins improve atherosclerosis-associated endothelial progenitor cell dysfunction via microRNA transfer154Arterial remodeling and metabolism impairment in early atherosclerosis155Role of pannexin1 in atherosclerotic plaque formationCalcium fluxes and excitation-contraction coupling158Amphiphysin II induces tubule formation in cardiac cells159Interleukin 1 beta regulation of connexin 43 in cardiac fibroblasts and the effects of adult cardiac myocyte:fibroblast co-culture on myocyte contraction160T-tubular electrical defects contribute to blunted beta-adrenergic response in heart failure161Beat-to-beat variability of intracellular Ca2+ dynamics of Purkinje cells in the infarct border zone of the mouse heart revealed by rapid-scanning confocal microscopy162The efficacy of late sodium current blockers in hypertrophic cardiomyopathy is dependent on genotype: a study on transgenic mouse models with different mutations163Synthesis of cADPR and NAADP by intracellular CD38 in heart: role in inotropic and arrhythmogenic effects of beta-adrenoceptor signalingContractile apparatus166Towards an engineered heart tissue model of HCM using hiPSC expressing the ACTC E99K mutation167Diastolic mechanical load delays structural and functional deterioration of ultrathin adult heart slices in culture168Structural investigation of the cardiac troponin complex by molecular dynamics169Exercise training restores myocardial and oxidative skeletal muscle function from myocardial infarction heart failure ratsOxygen sensing, ischaemia and reperfusion172A novel antibody specific to full-length stromal derived factor-1 alpha reveals that remote conditioning induces its cleavage by endothelial dipeptidyl peptidase 4173Attenuation of myocardial and vascular arginase activity by vagal nerve stimulation via a mechanism involving alpha-7 nicotinic receptor during cardiac ischemia and reperfusion174Novel nanoparticle-mediated medicine for myocardial ischemia-reperfusion injury simultaneously targeting mitochondrial injury and myocardial inflammation175Acetylcholine plays a key role in myocardial ischaemic preconditioning via recruitment of intrinsic cardiac ganglia176The role of nitric oxide and VEGFR-2 signaling in post ischemic revascularization and muscle recovery in aged hypercholesterolemic mice177Efficacy of ischemic preconditioning to protect the human myocardium: the role of clinical conditions and treatmentsCardiomyopathies and fibrosis180Plakophilin-2 haploinsufficiency leads to impaired canonical Wnt signaling in ARVC patient181Improved technique for customized, easier, safer and more reliable transverse aortic arch banding and debanding in mice as a model of pressure overload hypertrophy182Late sodium current inhibitors for the treatment of inducible obstruction and diastolic dysfunction in hypertrophic cardiomyopathy: a study on human myocardium183Angiotensin II receptor antagonist fimasartan has protective role of left ventricular fibrosis and remodeling in the rat ischemic heart184Role of High-Mobility Group Box 1 (HMGB1) redox state on cardiac fibroblasts activities and heart function after myocardial infarction185Atrial remodeling in hypertrophic cardiomyopathy: insights from mouse models carrying different mutations in cTnT186Electrophysiological abnormalities in ventricular cardiomyocytes from a Maine Coon cat with hypertrophic cardiomyopathy: effects of ranolazine187ZBTB17 is a novel cardiomyopathy candidate gene and regulates autophagy in the heart188Inhibition of SRSF4 in cardiomyocytes induces left ventricular hypertrophy189Molecular characterization of a novel cardiomyopathy related desmin frame shift mutation190Autonomic characterisation of electro-mechanical remodeling in an in-vitro leporine model of heart failure191Modulation of Ca2+-regulatory function by three novel mutations in TNNI3 associated with severe infant restrictive cardiomyopathyAging194The aging impact on cardiac mesenchymal like stromal cells (S+P+)195Reversal of premature aging markers after bariatric surgery196Sex-associated differences in vascular remodeling during aging: role of renin-angiotensin system197Role of the receptor for advanced glycation end-products (RAGE) in age dependent left ventricle dysfunctionsGenetics and epigenetics200hsa-miR-21-5p as a key factor in aortic remodeling during aneurysm formation201Co-inheritance of mutations associated with arrhythmogenic and hypertrophic cardiomyopathy in two Italian families202Lamin a/c hot spot codon 190: form various amino acid substitutions to clinical effects203Treatment with aspirin and atorvastatin attenuate cardiac injury induced by rat chest irradiation: Implication of myocardial miR-1, miR-21, connexin-43 and PKCGenomics, proteomics, metabolomics, lipidomics and glycomics206Differential phosphorylation of desmin at serines 27 and 31 drives the accumulation of preamyloid oligomers in heart failure207Potential role of kinase Akt2 in the reduced recovery of type 2 diabetic hearts subjected to ischemia / reperfusion injury208A proteomics comparison of extracellular matrix remodelling in porcine coronary arteries upon stent implantationMetabolism, diabetes mellitus and obesity211Targeting grk2 as therapeutic strategy for cancer associated to diabetes212Effects of salbutamol on large arterial stiffness in patients with metabolic syndrome213Circulating microRNA-1 and microRNA-133a: potential biomarkers of myocardial steatosis in type 2 diabetes mellitus214Anti-inflammatory nutrigenomic effects of hydroxytyrosol in human adipocytes - protective mechanisms of mediterranean diets in obesity-related inflammation215Alterations in the metal content of different cardiac regions within a rat model of diabetic cardiomyopathyTissue engineering218A novel conductive patch for application in cardiac tissue engineering219Establishment of a simplified and improved workflow from neonatal heart dissociation to cardiomyocyte purification and characterization220Effects of flexible substrate on cardiomyocytes cell culture221Mechanical stretching on cardiac adipose progenitors upregulates sarcomere-related genes. Cardiovasc Res 2016. [DOI: 10.1093/cvr/cvw135] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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Sag CM, Ward A, Crocini C, Watkins A, Hayer S, Wang Y, Rex N, Wagner S, De Franceschi L, Vinchi F, Cimino J, Petrillo S, Silengo L, Altruda F, Maier LS, Hirsch E, Ghigo A, Tolosano E, Angelini GD, George SJ, Zakkar M, Ferrantini C, Coppini R, Scardigli M, Yan P, Loew LM, Smith G, Cerbai E, Poggesi C, Pavone FS, Sacconi L, Church S, Begley P, Eisner D, Trafford A, Cooper G, Inci M, Niederreiter B, Shvets T, Redlich K, Kiss A, Podesser B, D'Souza A, Johnsen AB, Olieslagers S, Bucchi A, Martins PDC, DiFrancesco D, Dobrzynski H, Piggins HD, Boyett MR. Late Breaking Science502Hemopexin counteracts systolic dysfunction induced by heme overload503Inhibition of NF-kappa B suppressed inflammation induced by acute shear stress in endothelial cells: Implications for vein graft failure504Optical treatment of cardiac arrhythmias505Tachypacing-induced heart failure: a metabolomic investigation506Characterization of early left ventricle dysfunction in a relevant experimental model for human rheumatoid arthritis507Circadian rhythm in heart rate is due to an intrinsic circadian clock in the sinus node. Cardiovasc Res 2016. [DOI: 10.1093/cvr/cvw142] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Benedetti L, Ghilardi A, Rottoli E, De Maglie M, Prosperi L, Perego C, Baruscotti M, Bucchi A, Del Giacco L, Francolini M. INaP selective inhibition reverts precocious inter- and motorneurons hyperexcitability in the Sod1-G93R zebrafish ALS model. Sci Rep 2016; 6:24515. [PMID: 27079797 PMCID: PMC4832213 DOI: 10.1038/srep24515] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2015] [Accepted: 03/29/2016] [Indexed: 12/11/2022] Open
Abstract
The pathogenic role of SOD1 mutations in amyotrophic lateral sclerosis (ALS) was investigated using a zebrafish disease model stably expressing the ALS-linked G93R mutation. In addition to the main pathological features of ALS shown by adult fish, we found remarkably precocious alterations in the development of motor nerve circuitry and embryo behavior, and suggest that these alterations are prompted by interneuron and motor neuron hyperexcitability triggered by anomalies in the persistent pacemaker sodium current INaP. The riluzole-induced modulation of INaP reduced spinal neuron excitability, reverted the behavioral phenotypes and improved the deficits in motor nerve circuitry development, thus shedding new light on the use of riluzole in the management of ALS. Our findings provide a valid phenotype-based tool for unbiased in vivo drug screening that can be used to develop new therapies.
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Affiliation(s)
- Lorena Benedetti
- Department of Medical Biotechnology and Translational Medicine, University of Milan, Neuroscience Institute, National Research Council (CNR), Via Vanvitelli 32, 20139 Milano, Italy
| | - Anna Ghilardi
- Department of BioSciences, University of Milan, Via Celoria 26, 20133 Milano, Italy
| | - Elsa Rottoli
- Department of Medical Biotechnology and Translational Medicine, University of Milan, Neuroscience Institute, National Research Council (CNR), Via Vanvitelli 32, 20139 Milano, Italy
| | - Marcella De Maglie
- Department of Veterinary Science and Public Health, University of Milan, Via Celoria 10, 20133 Milano, Italy
| | - Laura Prosperi
- Department of BioSciences, University of Milan, Via Celoria 26, 20133 Milano, Italy
| | - Carla Perego
- Department of Pharmacological and Biomolecular Sciences, University of Milan, Via Trentacoste 2, 20133 Milano, Italy
| | - Mirko Baruscotti
- Department of BioSciences, University of Milan, Via Celoria 26, 20133 Milano, Italy
| | - Annalisa Bucchi
- Department of BioSciences, University of Milan, Via Celoria 26, 20133 Milano, Italy
| | - Luca Del Giacco
- Department of BioSciences, University of Milan, Via Celoria 26, 20133 Milano, Italy
| | - Maura Francolini
- Department of Medical Biotechnology and Translational Medicine, University of Milan, Neuroscience Institute, National Research Council (CNR), Via Vanvitelli 32, 20139 Milano, Italy
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Baruscotti M, Bianco E, Bucchi A, DiFrancesco D. Current understanding of the pathophysiological mechanisms responsible for inappropriate sinus tachycardia: role of the If "funny" current. J Interv Card Electrophysiol 2016; 46:19-28. [PMID: 26781742 DOI: 10.1007/s10840-015-0097-y] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/10/2015] [Accepted: 12/28/2015] [Indexed: 01/01/2023]
Abstract
BACKGROUND Together with the afferent branches of the autonomic nervous system, the sinoatrial node (SAN) forms a functional unit whose function is to fire rhythmic action potentials at a rate optimal for coping with the metabolic needs of the body. Dysfunctional behavior of this complex unit may thus result in SAN rhythm disorders. Among these disorders, there is the inappropriate sinus tachycardia (IST) which occurs when an unjustified fast SAN rate is present. METHODS We here present a critical review of the role of pacemaker f/HCN channels in cardiac rhythm generation and modulation and their involvement in IST. RESULTS Recent evidence demonstrates that a familial form of IST is associated with a gain-of-function mutation in the HCN4 pacemaker channel (R524Q) which confers an increased sensitivity to the second messenger cAMP, a key mediator in sympathetic modulation. CONCLUSIONS This finding is consistent with the general view that hypersympathetic tone is one of the causes of IST and introduces the novel concept of defective funny channel-dependent tachyarrhythmias.
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Affiliation(s)
- Mirko Baruscotti
- Department of Biosciences, Centro Interuniversitario di Medicina Molecolare e Biofisica Applicata, University of Milano, via Celoria 26, 20133, Milano, Italy.
| | - Elisabetta Bianco
- Cardiovascular Department, "Ospedali Riuniti di Trieste", University Hospital, Trieste, Italy
| | - Annalisa Bucchi
- Department of Biosciences, Centro Interuniversitario di Medicina Molecolare e Biofisica Applicata, University of Milano, via Celoria 26, 20133, Milano, Italy
| | - Dario DiFrancesco
- Department of Biosciences, Centro Interuniversitario di Medicina Molecolare e Biofisica Applicata, University of Milano, via Celoria 26, 20133, Milano, Italy.
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Ravagli E, Bucchi A, Bartolucci C, Paina M, Baruscotti M, DiFrancesco D, Severi S. Cell-specific Dynamic Clamp analysis of the role of funny If current in cardiac pacemaking. Prog Biophys Mol Biol 2015; 120:50-66. [PMID: 26718599 DOI: 10.1016/j.pbiomolbio.2015.12.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2015] [Revised: 11/18/2015] [Accepted: 12/16/2015] [Indexed: 01/01/2023]
Abstract
We used the Dynamic Clamp technique for i) comparative validation of conflicting computational models of the hyperpolarization-activated funny current, If, and ii) quantification of the role of If in mediating autonomic modulation of heart rate. Experimental protocols based on the injection of a real-time recalculated synthetic If current in sinoatrial rabbit cells were developed. Preliminary results of experiments mimicking the autonomic modulation of If demonstrated the need for a customization procedure to compensate for cellular heterogeneity. For this reason, we used a cell-specific approach, scaling the maximal conductance of the injected current based on the cell's spontaneous firing rate. The pacemaking rate, which was significantly reduced after application of Ivabradine, was restored by the injection of synthetic current based on the Severi-DiFrancesco formulation, while the injection of synthetic current based on the Maltsev-Lakatta formulation did not produce any significant variation. A positive virtual shift of the If activation curve, mimicking the Isoprenaline effects, led to a significant increase in pacemaking rate (+17.3 ± 6.7%, p < 0.01), although of lower magnitude than that induced by real Isoprenaline (+45.0 ± 26.1%). Similarly, a negative virtual shift of the activation curve significantly lowered the pacemaking rate (-11.8 ± 1.9%, p < 0.001), as did the application of real Acetylcholine (-20.5 ± 5.1%). The Dynamic Clamp approach, applied to the If study in cardiomyocytes for the first time and rate-adapted to manage intercellular variability, indicated that: i) the quantitative description of the If current in the Severi-DiFrancesco model accurately reproduces the effects of the real current on rabbit sinoatrial cell pacemaking rate and ii) a significant portion (50-60%) of the physiological autonomic rate modulation is due to the shift of the If activation curve.
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Affiliation(s)
- E Ravagli
- Computational Physiopathology Unit, Laboratory of Cellular and Molecular Engineering, D.E.I., University of Bologna, Via Venezia 52, 47521 Cesena, Italy
| | - A Bucchi
- The PaceLab, Department of Biosciences, University of Milan, Via Celoria 26, 20133 Milano, Italy
| | - C Bartolucci
- Computational Physiopathology Unit, Laboratory of Cellular and Molecular Engineering, D.E.I., University of Bologna, Via Venezia 52, 47521 Cesena, Italy
| | - M Paina
- The PaceLab, Department of Biosciences, University of Milan, Via Celoria 26, 20133 Milano, Italy
| | - M Baruscotti
- The PaceLab, Department of Biosciences, University of Milan, Via Celoria 26, 20133 Milano, Italy
| | - D DiFrancesco
- The PaceLab, Department of Biosciences, University of Milan, Via Celoria 26, 20133 Milano, Italy
| | - S Severi
- Computational Physiopathology Unit, Laboratory of Cellular and Molecular Engineering, D.E.I., University of Bologna, Via Venezia 52, 47521 Cesena, Italy.
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D'Souza A, Bucchi A, Johnsen AB, Logantha SJRJ, Monfredi O, Yanni J, Prehar S, Hart G, Cartwright E, Wisloff U, Dobryznski H, DiFrancesco D, Morris GM, Boyett MR. Exercise training reduces resting heart rate via downregulation of the funny channel HCN4. Nat Commun 2014; 5:3775. [PMID: 24825544 PMCID: PMC4024745 DOI: 10.1038/ncomms4775] [Citation(s) in RCA: 160] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2014] [Accepted: 04/01/2014] [Indexed: 12/14/2022] Open
Abstract
Endurance athletes exhibit sinus bradycardia, that is a slow resting heart rate, associated with a higher incidence of sinus node (pacemaker) disease and electronic pacemaker implantation. Here we show that training-induced bradycardia is not a consequence of changes in the activity of the autonomic nervous system but is caused by intrinsic electrophysiological changes in the sinus node. We demonstrate that training-induced bradycardia persists after blockade of the autonomous nervous system in vivo in mice and in vitro in the denervated sinus node. We also show that a widespread remodelling of pacemaker ion channels, notably a downregulation of HCN4 and the corresponding ionic current, If. Block of If abolishes the difference in heart rate between trained and sedentary animals in vivo and in vitro. We further observe training-induced downregulation of Tbx3 and upregulation of NRSF and miR-1 (transcriptional regulators) that explains the downregulation of HCN4. Our findings provide a molecular explanation for the potentially pathological heart rate adaptation to exercise training. Endurance athletes are known to have a low resting heart rate. Here, D'Souza et al. propose that training-induced bradycardia is the result of electrophysiological changes in the sinus node, challenging the classical view that training-induced bradycardia is caused by increased activity of the autonomic nervous system.
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Affiliation(s)
- Alicia D'Souza
- 1] Institute of Cardiovascular Sciences, University of Manchester, Manchester M13 9NT, UK [2]
| | - Annalisa Bucchi
- 1] Department of Biosciences, University of Milano, Milano 20133, Italy [2]
| | - Anne Berit Johnsen
- 1] Department of Circulation and Medical Imaging, Norwegian University of Science and Technology, Trondheim 7491, Norway [2]
| | - Sunil Jit R J Logantha
- 1] Institute of Cardiovascular Sciences, University of Manchester, Manchester M13 9NT, UK [2]
| | - Oliver Monfredi
- Institute of Cardiovascular Sciences, University of Manchester, Manchester M13 9NT, UK
| | - Joseph Yanni
- Institute of Cardiovascular Sciences, University of Manchester, Manchester M13 9NT, UK
| | - Sukhpal Prehar
- Institute of Cardiovascular Sciences, University of Manchester, Manchester M13 9NT, UK
| | - George Hart
- Institute of Cardiovascular Sciences, University of Manchester, Manchester M13 9NT, UK
| | - Elizabeth Cartwright
- Institute of Cardiovascular Sciences, University of Manchester, Manchester M13 9NT, UK
| | - Ulrik Wisloff
- Department of Circulation and Medical Imaging, Norwegian University of Science and Technology, Trondheim 7491, Norway
| | - Halina Dobryznski
- Institute of Cardiovascular Sciences, University of Manchester, Manchester M13 9NT, UK
| | - Dario DiFrancesco
- Department of Biosciences, University of Milano, Milano 20133, Italy
| | - Gwilym M Morris
- Institute of Cardiovascular Sciences, University of Manchester, Manchester M13 9NT, UK
| | - Mark R Boyett
- Institute of Cardiovascular Sciences, University of Manchester, Manchester M13 9NT, UK
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Scavone A, Capilupo D, Mazzocchi N, Crespi A, Zoia S, Campostrini G, Bucchi A, Milanesi R, Baruscotti M, Benedetti S, Antonini S, Messina G, DiFrancesco D, Barbuti A. Embryonic stem cell-derived CD166+ precursors develop into fully functional sinoatrial-like cells. Circ Res 2013; 113:389-98. [PMID: 23753573 DOI: 10.1161/circresaha.113.301283] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
RATIONALE A cell-based biological pacemaker is based on the differentiation of stem cells and the selection of a population displaying the molecular and functional properties of native sinoatrial node (SAN) cardiomyocytes. So far, such selection has been hampered by the lack of proper markers. CD166 is specifically but transiently expressed in the mouse heart tube and sinus venosus, the prospective SAN. OBJECTIVE We have explored the possibility of using CD166 expression for isolating SAN progenitors from differentiating embryonic stem cells. METHODS AND RESULTS We found that in embryonic day 10.5 mouse hearts, CD166 and HCN4, markers of the pacemaker tissue, are coexpressed. Sorting embryonic stem cells for CD166 expression at differentiation day 8 selects a population of pacemaker precursors. CD166+ cells express high levels of genes involved in SAN development (Tbx18, Tbx3, Isl-1, Shox2) and function (Cx30.2, HCN4, HCN1, CaV1.3) and low levels of ventricular genes (Cx43, Kv4.2, HCN2, Nkx2.5). In culture, CD166+ cells form an autorhythmic syncytium composed of cells morphologically similar to and with the electrophysiological properties of murine SAN myocytes. Isoproterenol increases (+57%) and acetylcholine decreases (-23%) the beating rate of CD166-selected cells, which express the β-adrenergic and muscarinic receptors. In cocultures, CD166-selected cells are able to pace neonatal ventricular myocytes at a rate faster than their own. Furthermore, CD166+ cells have lost pluripotency genes and do not form teratomas in vivo. CONCLUSIONS We demonstrated for the first time the isolation of a nonteratogenic population of cardiac precursors able to mature and form a fully functional SAN-like tissue.
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Affiliation(s)
- Angela Scavone
- Department of Biosciences, Università degli Studi di Milano, Milano, Italy
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Bucchi A, Baruscotti M, Nardini M, Barbuti A, Micheloni S, Bolognesi M, DiFrancesco D. Identification of the molecular site of ivabradine binding to HCN4 channels. PLoS One 2013; 8:e53132. [PMID: 23308150 PMCID: PMC3537762 DOI: 10.1371/journal.pone.0053132] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2012] [Accepted: 11/23/2012] [Indexed: 12/26/2022] Open
Abstract
Ivabradine is a specific heart rate-reducing agent approved as a treatment of chronic stable angina. Its mode of action involves a selective and specific block of HCN channels, the molecular components of sinoatrial "funny" (f)-channels. Different studies suggest that the binding site of ivabradine is located in the inner vestibule of HCN channels, but the molecular details of ivabradine binding are unknown. We thus sought to investigate by mutagenesis and in silico analysis which residues of the HCN4 channel, the HCN isoform expressed in the sinoatrial node, are involved in the binding of ivabradine. Using homology modeling, we verified the presence of an inner cavity below the channel pore and identified residues lining the cavity; these residues were replaced with alanine (or valine) either alone or in combination, and WT and mutant channels were expressed in HEK293 cells. Comparison of the block efficiency of mutant vs WT channels, measured by patch-clamp, revealed that residues Y506, F509 and I510 are involved in ivabradine binding. For each mutant channel, docking simulations correctly explain the reduced block efficiency in terms of proportionally reduced affinity for ivabradine binding. In summary our study shows that ivabradine occupies a cavity below the channel pore, and identifies specific residues facing this cavity that interact and stabilize the ivabradine molecule. This study provides an interpretation of known properties of f/HCN4 channel block by ivabradine such as the “open channel block”, the current-dependence of block and the property of "trapping" of drug molecules in the closed configuration.
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Affiliation(s)
- Annalisa Bucchi
- The PaceLab, Department of Life Sciences, Università degli Studi di Milano, Milano, Italy
- Centro Interuniversitario di Medicina Molecolare e Biofisica Applicata, Università degli Studi di Milano, Milano, Italy
| | - Mirko Baruscotti
- The PaceLab, Department of Life Sciences, Università degli Studi di Milano, Milano, Italy
- Centro Interuniversitario di Medicina Molecolare e Biofisica Applicata, Università degli Studi di Milano, Milano, Italy
| | - Marco Nardini
- Laboratory of Protein Biochemistry, Department of Life Sciences, Università degli Studi di Milano, Milano, Italy
| | - Andrea Barbuti
- The PaceLab, Department of Life Sciences, Università degli Studi di Milano, Milano, Italy
- Centro Interuniversitario di Medicina Molecolare e Biofisica Applicata, Università degli Studi di Milano, Milano, Italy
| | - Stefano Micheloni
- The PaceLab, Department of Life Sciences, Università degli Studi di Milano, Milano, Italy
| | - Martino Bolognesi
- Laboratory of Protein Biochemistry, Department of Life Sciences, Università degli Studi di Milano, Milano, Italy
| | - Dario DiFrancesco
- The PaceLab, Department of Life Sciences, Università degli Studi di Milano, Milano, Italy
- Centro Interuniversitario di Medicina Molecolare e Biofisica Applicata, Università degli Studi di Milano, Milano, Italy
- * E-mail:
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31
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Bucchi A, Barbuti A, Difrancesco D, Baruscotti M. Funny Current and Cardiac Rhythm: Insights from HCN Knockout and Transgenic Mouse Models. Front Physiol 2012; 3:240. [PMID: 22783204 PMCID: PMC3387723 DOI: 10.3389/fphys.2012.00240] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2012] [Accepted: 06/12/2012] [Indexed: 01/01/2023] Open
Abstract
In the adult animal the sinoatrial node (SAN) rhythmically generates a depolarizing wave that propagates to the rest of the heart. However, the SAN is more than a simple clock; it is a clock that adjusts its pace according to the metabolic requirements of the organism. The Hyperpolarization-activated Cyclic Nucleotide-gated channels (HCN1–4) are the structural component of the funny (If) channels; in the SAN the If current is the main driving electrical force of the diastolic depolarization and the HCN4 is the most abundant isoform. The generation of HCN KO and transgenic mouse models has advanced the understanding of the role of these channels in cardiac excitability. The HCN4 KO models that were first developed allowed either global or cardiac-specific constitutive ablation of HCN4 channels, and resulted in embryonic lethality. A further progress was made with the development of three separate inducible HCN4 KO models; in one model KO was induced globally in the entire organism, in a second, ablation occurred only in HCN4-expressing cells, and finally in a third model KO was confined to cardiac cells. Unexpectedly, the three models yielded different results; similarities and differences among these models will be presented and discussed. The functional effects of HCN2 and HCN3 knockout models and transgenic HCN4 mouse models will also be discussed. In conclusion, HCN KO/transgenic models have allowed to evaluate the functional role of the If currents in intact animals as well as in single SAN cells isolated from the same animals. This opportunity is therefore unique since it allows (1) to verify the contribution of specific HCN isoforms to cardiac activity in intact animals, and (2) to compare these results to those obtained in single cell experiments. These combined studies were not possible prior to the development of KO models. Finally, these models represent critical tools to improve our understanding of the molecular basis of some inheritable arrhythmic human pathologies.
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Affiliation(s)
- Annalisa Bucchi
- Department of Biosciences, University of Milano Milano, Italy
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Abstract
In mammals cardiac rate is determined by the duration of the diastolic depolarization of sinoatrial node (SAN) cells which is mainly determined by the pacemaker I(f) current. f-channels are encoded by four members of the hyperpolarization-activated cyclic nucleotide-gated gene (HCN1-4) family. HCN4 is the most abundant isoform in the SAN, and its relevance to pacemaking has been further supported by the discovery of four loss-of-function mutations in patients with mild or severe forms of cardiac rate disturbances. Due to its selective contribution to pacemaking, the I(f) current is also the pharmacological target of a selective heart rate-reducing agent (ivabradine) currently used in the clinical practice. Albeit to a minor extent, the I(f) current is also present in other spontaneously active myocytes of the cardiac conduction system (atrioventricular node and Purkinje fibres). In working atrial and ventricular myocytes f-channels are expressed at a very low level and do not play any physiological role; however in certain pathological conditions over-expression of HCN proteins may represent an arrhythmogenic mechanism. In this review some of the most recent findings on f/HCN channels contribution to pacemaking are described.
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Affiliation(s)
- Mirko Baruscotti
- Department of Biomolecular Sciences and Biotechnology, Laboratory of Molecular Physiology and Neurobiology, Università degli Studi di Milano, Centro Interuniversitario di Medicina Molecolare e Biofisica Applicata (CIMMBA), via Celoria 26, 20133 Milano, Italy.
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33
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Zhao X, Bucchi A, Oren RV, Kryukova Y, Dun W, Clancy CE, Robinson RB. In vitro characterization of HCN channel kinetics and frequency dependence in myocytes predicts biological pacemaker functionality. J Physiol 2009; 587:1513-25. [PMID: 19171659 DOI: 10.1113/jphysiol.2008.163444] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
The pacemaker current, mediated by hyperpolarization-activated cyclic nucleotide-gated (HCN) channels, contributes to the initiation and regulation of cardiac rhythm. Previous experiments creating HCN-based biological pacemakers in vivo found that an engineered HCN2/HCN1 chimeric channel (HCN212) resulted in significantly faster rates than HCN2, interrupted by 1-5 s pauses. To elucidate the mechanisms underlying the differences in HCN212 and HCN2 in vivo functionality as biological pacemakers, we studied newborn rat ventricular myocytes over-expressing either HCN2 or HCN212 channels. The HCN2- and HCN212-over-expressing myocytes manifest similar voltage dependence, current density and sensitivity to saturating cAMP concentrations, but HCN212 has faster activation/deactivation kinetics. Compared with HCN2, myocytes expressing HCN212 exhibit a faster spontaneous rate and greater incidence of irregular rhythms (i.e. periods of rapid spontaneous rate followed by pauses). To explore these rhythm differences further, we imposed consecutive pacing and found that activation kinetics of the two channels are slower at faster pacing frequencies. As a result, time-dependent HCN current flowing during diastole decreases for both constructs during a train of stimuli at a rapid frequency, with the effect more pronounced for HCN2. In addition, the slower deactivation kinetics of HCN2 contributes to more pronounced instantaneous current at a slower frequency. As a result of the frequency dependence of both instantaneous and time-dependent current, HCN2 exhibits more robust negative feedback than HCN212, contributing to the maintenance of a stable pacing rhythm. These results illustrate the benefit of screening HCN constructs in spontaneously active myocyte cultures and may provide the basis for future optimization of HCN-based biological pacemakers.
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Affiliation(s)
- Xin Zhao
- Department of Pharmacology, College of Physicians and Surgeons, Columbia University, New York, NY, USA
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34
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Protas L, Dun W, Jia Z, Lu J, Bucchi A, Kumari S, Chen M, Cohen IS, Rosen MR, Entcheva E, Robinson RB. Expression of skeletal but not cardiac Na+ channel isoform preserves normal conduction in a depolarized cardiac syncytium. Cardiovasc Res 2008; 81:528-35. [PMID: 18977767 DOI: 10.1093/cvr/cvn290] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
AIMS Reentrant arrhythmias often develop in the setting of myocardial infarction and ensuing slow propagation. Increased Na(+) channel expression could prevent or disrupt reentrant circuits by speeding conduction if channel availability is not limited by membrane depolarization within the diseased myocardium. We therefore asked if, in the setting of membrane depolarization, action potential (AP) upstroke and normal conduction can be better preserved by the expression of a Na(+) channel isoform with altered biophysical properties compared to the native cardiac Na(+) channel isoform, namely having a positively shifted, voltage-dependent inactivation. METHODS AND RESULTS The skeletal Na(+) channel isoform (SkM1) and the cardiac Na(+) channel isoform (Nav1.5) were expressed in newborn rat ventricular myocyte cultures with a point mutation introduced in Nav1.5 to increase tetrodotoxin (TTX) sensitivity so native and expressed currents could be distinguished. External K(+) was increased from 5.4 to 10 mmol/L to induce membrane depolarization. APs, Na(+) currents, and conduction velocity (CV) were measured. In control cultures, elevated K(+) significantly reduced AP upstroke ( approximately 75%) and CV ( approximately 25%). Expression of Nav1.5 did not protect AP upstroke from K(+) depolarization. In contrast, in SkM1 expressing cultures, high K(+) reduced AP upstroke <50% and conduction was not significantly reduced. In a simulated anatomical reentry setting (using a void), the angular velocity (AV) of induced reentry was faster and the excitable gap shorter in SkM1 cultures compared to control for both normal and high K(+). CONCLUSION Expression of SkM1 but not Nav1.5 preserves AP upstroke and CV in a K(+)-depolarized syncytium. The higher AV and shorter excitable gap observed during reentry excitation around a void in SkM1 cultures would be expected to facilitate reentry self-termination. SkM1 Na(+) channel expression represents a novel gene therapy for the treatment of reentrant arrhythmias.
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Affiliation(s)
- Lev Protas
- Department of Pharmacology, College of Physicians and Surgeons, Columbia University, 630 West 168 Street, Room PH7West-318, New York, NY 10032, USA
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Plotnikov AN, Bucchi A, Shlapakova I, Danilo P, Brink PR, Robinson RB, Cohen IS, Rosen MR. HCN212-channel biological pacemakers manifesting ventricular tachyarrhythmias are responsive to treatment with I(f) blockade. Heart Rhythm 2007; 5:282-8. [PMID: 18242555 DOI: 10.1016/j.hrthm.2007.09.028] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/21/2007] [Accepted: 09/28/2007] [Indexed: 11/28/2022]
Abstract
BACKGROUND A potential concern about biological pacemakers is their possible malfunction, which might create ventricular tachycardias (VTs). OBJECTIVE The purpose of this study was to test our hypothesis that should VTs complicate implantation of HCN-channel-based biological pacemakers, they would be suppressed by inhibitors of the pacemaker current, I(f). METHODS We created a chimeric channel (HCN212) containing the N- and C-termini of mouse HCN2 and the transmembrane region of mouse HCN1 and implanted it in HEK293 cells. Forty-eight hours later, in whole-cell patch clamp recordings, mean steady state block induced by 3 microM ivabradine (IVB) showed HCN1 = HCN212 > HCN2 currents. The HCN212 adenoviral construct was then implanted into the canine left bundle branch in 11 dogs. Complete AV block was created via radiofrequency ablation, and a ventricular demand electronic pacemaker was implanted (VVI 45 bpm). Electrocardiogram, 24-hour Holter monitoring, and pacemaker log record check were performed for 11 days. RESULTS All dogs developed rapid VT (>120 bpm, maximum rate = 285 +/- 37 bpm) at 0.9 +/- 0.3 days after implantation that persisted through 5 +/- 1 days. IVB, 1 mg/kg over 5 minutes, was administered during rapid VT, and three dogs received a second dose 24 hours later. While VT terminated with IBV in all instances within 3.4 +/- 0.6 minutes, no effect of IVB on sinus rate was noted. CONCLUSION We conclude that (1) I(f)-associated tachyarrhythmias-if they occur with HCN-based biological pacemakers-can be controlled with I(f)-inhibiting drugs such as IVB; (2) in vitro, IVB appears to have a greater steady state inhibiting effect on HCN1 and HCN212 isoforms than on HCN4; and (3) VT originating from the HCN212 injection site is suppressed more readily than sinus rhythm. This suggests a selectivity of IVB at the concentration attained for ectopic over HCN4-based pacemaker function. This might confer a therapeutic benefit.
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Affiliation(s)
- Alexei N Plotnikov
- Center for Molecular Therapeutics, Columbia University, New York, New York 10032, USA
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36
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Bucchi A, Baruscotti M, Robinson RB, DiFrancesco D. Modulation of rate by autonomic agonists in SAN cells involves changes in diastolic depolarization and the pacemaker current. J Mol Cell Cardiol 2007; 43:39-48. [PMID: 17543331 DOI: 10.1016/j.yjmcc.2007.04.017] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/31/2007] [Revised: 03/25/2007] [Accepted: 04/23/2007] [Indexed: 11/29/2022]
Abstract
Two distinct intracellular mechanisms have been proposed to affect the firing rate of cardiac pacemaker cells: one involves modulation of the I(f) current by the second messenger cAMP, and one relies upon disruption or alteration of SR Ca2+ transients during activity. Although both mechanisms are necessary for proper automaticity and autonomic rate control, the specific contribution of each to pacemaking is still debated. We investigated if the two processes can be separated based on potentially different effects on action potential characteristics during rate modulation. To identify specific I(f)-mediated effects, we used the selective I(f) blocker ivabradine and found that ivabradine (3 microM) slows rate (-16.2%) by selectively reducing (-31.9%) the steepness of early diastolic depolarization (EDD). On the other hand ryanodine (3 microM), used to evaluate the effects of abolishment of SR Ca2+ transients, slowed rate (-31.3%) by depolarizing the take-off potential (TOP, 18.1%) without affecting EDD. We therefore used these two parameters to identify I(f)-based or SR Ca2+ transients-based processes and analyzed the effects on action potential's characteristics of Rp-cAMPs (50 microM), a membrane permeable cAMP analogue directly activating f-channels; we found that Rp-cAMPs accelerates rate by increasing EDD (+42.3%) without modifying TOP. Finally, rate modulation was achieved by muscarinic (ACh 0.01 microM) or beta-adrenergic (Iso 1 microM) stimulation; in both cases, rate changes were associated with modifications of EDD (ACh, -29.3% and Iso, +47.6%) and not of TOP. We conclude that rate-related changes in the EDD induced by autonomic agonists are mediated by I(f) and not by processes involving SR Ca2+ transients.
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Affiliation(s)
- Annalisa Bucchi
- University of Milano, Department of Biomolecular Sciences and Biotechnology, Laboratory of Molecular Physiology and Neurobiology, via Celoria 26, 20133 Milano, Italy
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Pian P, Bucchi A, Decostanzo A, Robinson RB, Siegelbaum SA. Modulation of cyclic nucleotide-regulated HCN channels by PIP(2) and receptors coupled to phospholipase C. Pflugers Arch 2007; 455:125-45. [PMID: 17605039 DOI: 10.1007/s00424-007-0295-2] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2007] [Accepted: 05/16/2007] [Indexed: 10/24/2022]
Abstract
Recent results indicate that phosphoinositides, including phosphatidylinositol 4,5-bisphosphate (PI(4,5)P(2)), directly enhance the opening of hyperpolarization-activated, cyclic nucleotide-regulated (HCN) channels by shifting their activation gating to more positive voltages. This contrasts with the action of phosphoinositides to inhibit the opening of the related cyclic nucleotide-gated (CNG) channels involved in sensory signaling. We both review previous studies and present new experiments that investigate whether HCN channels may be regulated by dynamic changes in PI(4,5)P(2) levels caused by the receptor-mediated activation of phospholipase C (PLC). We coexpressed HCN1 or HCN2 channels in Xenopus oocytes with the PLC-coupled bradykinin BK(2) receptor, the muscarinic M1 receptor, or the TrkA receptor. Activation of all three receptors produced a positive shift in HCN channel voltage gating, the opposite of the effect expected for PI(4,5)P(2) depletion. This action was not caused by alterations in cAMP as the effect was preserved in HCN mutant channels that fail to bind cAMP. The receptor effects were mediated by PLC activity, but did not depend on signaling through the downstream products of PI(4,5)P(2) hydrolysis: IP(3) or diacylglycerol (DAG). Importantly, the modulatory effects on gating were blocked by inhibitors of phosphatidylinositol (PI) kinases, suggesting a role for increased PI(4,5)P(2) synthesis. Finally, we found that bradykinin exerted a similar PI kinase-dependent effect on the gating of native HCN channels in cardiac sinoatrial node cells, suggesting that this pathway may represent a novel, physiologically relevant mechanism for enhancing HCN channel function.
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Affiliation(s)
- Phillip Pian
- Center for Neurobiology and Behavior, Columbia University Medical Center, New York, NY, 10032, USA
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38
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Baruscotti M, Bucchi A, Robinson RB, DiFrancesco D. Autonomic rate modulation in san cells involves changes in diastolic depolarization and the i(f) current. J Mol Cell Cardiol 2007. [DOI: 10.1016/j.yjmcc.2007.03.040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Bucchi A, Barbuti A, Baruscotti M, DiFrancesco D. Heart rate reduction via selective 'funny' channel blockers. Curr Opin Pharmacol 2007; 7:208-13. [PMID: 17267284 DOI: 10.1016/j.coph.2006.09.005] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2006] [Accepted: 09/07/2006] [Indexed: 11/23/2022]
Abstract
The 'funny' current, first described in cardiac pacemaker cells almost 30 years ago, is a key player in the generation of pacemaker activity and the autonomic modulation of heart rate. Because of these specific functions, a search for molecules able to interfere selectively with the 'funny' current was undertaken soon after its discovery, with the aim of developing tools for the pharmacological control of heart rate. This search has succeeded in generating a new class of drugs, the heart rate-reducing agents, which act through specific blockade of f-channels; one of these drugs, ivabradine, is presently marketed against stable angina. Because of their many functions in heart and other tissues, pharmacological utilization of "funny" channel properties is an exciting new frontier open to further developments.
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Affiliation(s)
- Annalisa Bucchi
- Laboratory of Molecular Physiology and Neurobiology, Department of Biomolecular Sciences and Biotechnology, University of Milan, via Celoria 26, Milano, Italy
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40
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Pian P, Bucchi A, Robinson RB, Siegelbaum SA. Regulation of gating and rundown of HCN hyperpolarization-activated channels by exogenous and endogenous PIP2. ACTA ACUST UNITED AC 2006; 128:593-604. [PMID: 17074978 PMCID: PMC2151583 DOI: 10.1085/jgp.200609648] [Citation(s) in RCA: 132] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The voltage dependence of activation of the HCN hyperpolarization-activated cation channels is shifted in inside-out patches by −40 to −60 mV relative to activation in intact cells, a phenomenon referred to as rundown. Less than 20 mV of this hyperpolarizing shift can be due to the influence of the canonical modulator of HCN channels, cAMP. Here we study the role of phosphatidylinositol 4,5-bisphosphate (PI(4,5)P2) in HCN channel rundown, as hydrolysis of PI(4,5)P2 by lipid phosphatases is thought to underlie rundown of several other channels. We find that bath application of exogenous PI(4,5)P2 reverses the effect of rundown, producing a large depolarizing shift in HCN2 activation. A synthetic short chain analogue of PI(4,5)P2, dioctanoyl phosphatidylinositol 4,5-bisphosphate, shifts the HCN2 activation curve to more positive potentials in a dose-dependent manner. Other dioctanoyl phosphatidylinositides with one or more phosphates on the lipid headgroup also shift activation, although phosphatidylinositol (PI) is ineffective. Several lines of evidence suggest that HCN2 is also regulated by endogenous PI(4,5)P2: (a) blockade of phosphatases slows the hyperpolarizing shift upon patch excision; (b) application of an antibody that binds and depletes membrane PIP2 causes a further hyperpolarizing shift in activation; (c) the shift in activation upon patch excision can be partially reversed by MgATP; and (d) the effect of MgATP is blocked by wortmannin, an inhibitor of PI kinases. Finally, recordings from rabbit sinoatrial cells demonstrate that diC8 PI(4,5)P2 delays the rundown of native HCN currents. Thus, both native and recombinant HCN channels are regulated by PI(4,5)P2.
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Affiliation(s)
- Phillip Pian
- Center for Neurobiology and Behavior, Columbia University Medical Center, New York, NY 10032, USA
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Bucchi A, Plotnikov AN, Shlapakova I, Danilo P, Kryukova Y, Qu J, Lu Z, Liu H, Pan Z, Potapova I, KenKnight B, Girouard S, Cohen IS, Brink PR, Robinson RB, Rosen MR. Wild-Type and Mutant HCN Channels in a Tandem Biological-Electronic Cardiac Pacemaker. Circulation 2006; 114:992-9. [PMID: 16923750 DOI: 10.1161/circulationaha.106.617613] [Citation(s) in RCA: 106] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Background—
Biological pacemakers (BPM) implanted in canine left bundle branch function competitively with electronic pacemakers (EPM). We hypothesized that BPM engineered with the use of mE324A mutant murine HCN2 (mHCN2) genes would improve function over mHCN2 and that BPM/EPM tandems confer advantage over either approach alone.
Methods and Results—
In cultured neonatal rat myocytes, activation midpoint was −46.9 mV in mE324A versus −66.1 mV in mHCN2 (
P
<0.05). mE324A manifested a positive shift of voltage dependence of gating kinetics of activation and deactivation compared with mHCN2 (
P
<0.05) in myocytes as well as
Xenopus
oocytes. In intact dogs in complete atrioventricular block, saline (control), mHCN2, or mE324A virus was injected into left bundle branch, and EPM were implanted (VVI 45 bpm). Twenty-four–hour ECGs were monitored for 14 days. With EPM discontinued, there was no difference in duration of overdrive suppression among groups. However, basal heart rates in controls were less than those in mHCN2, which did not differ from those in E324A (45 versus 57 versus 53 bpm;
P
<0.05). When spontaneous rate fell below 45 bpm, EPM intervened at that rate, triggering 83% of beats in control, contrasting (
P
<0.05) with 26% (mHCN2) and 36% (mE324A). On day 14, epinephrine (1 μg/kg per minute IV) induced a 50% heart rate increase in all mE324A, one third of mHCN2, and one fifth of control (
P
<0.05 mE324A versus control or mHCN2).
Conclusions—
mE324A induces faster, more positive pacemaker current activation than mHCN2 and stable, catecholamine-sensitive rhythms in situ that compete with EPM comparably but more catecholamine responsively than mHCN2. BPM/EPM tandems function reliably, reduce the number of EPM beats, and confer sympathetic responsiveness to the tandem.
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Affiliation(s)
- Annalisa Bucchi
- Departments of Pharmacology, Center for Molecular Therapeutics, Columbia University, New York, NY 10032, USA
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Rosen MR, Bucchi A, Robinson RB. I f modulation: perspectives in clinical medicine. Eur Heart J Suppl 2006. [DOI: 10.1093/eurheartj/sul018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
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Plotnikov AN, Shlapakova IN, Kryukova Y, Bucchi A, Danilo P, Kenknight BH, Girouard SD, Brink PR, Cohen IS, Robinson RB, Rosen MR. AB40-1. Heart Rhythm 2006. [DOI: 10.1016/j.hrthm.2006.02.254] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Abstract
Ivabradine is a 'heart rate-reducing' agent able to slow heart rate, without complicating side-effects. Its action results from a selective and specific block of pacemaker f-channels of the cardiac sinoatrial node (SAN). Investigation has shown that block by ivabradine requires open f-channels, is use dependent, and is affected by the direction of current flow. The constitutive elements of native pacemaker channels are the hyperpolarization-activated cyclic nucleotide-gated (HCN) channels, of which four isoforms (HCN1-4) are known; in rabbit SAN tissue HCN4 is expressed strongly, and HCN1 weakly. In this study we have investigated the blocking action of ivabradine on mouse (m) HCN1 and human (h) HCN4 channels heterologously expressed in HEK 293 cells. Ivabradine blocked both channels in a dose-dependent way with half-block concentrations of 0.94 microm for mHCN1 and 2.0 microm for hHCN4. Properties of block changed substantially for the two channels. Block of hHCN4 required open channels, was strengthened by depolarization and was relieved by hyperpolarization. Block of mHCN1 did not occur, nor was it relieved, when channels were in the open state during hyperpolarization; block required channels to be either closed, or in a transitional state between open and closed configurations. The dependence of block upon current flow was limited for hHCN4, and not significant for mHCN1 channels. In summary our results indicate that ivabradine is an 'open-channel' blocker of hHCN4, and a 'closed-channel' blocker of mHCN1 channels. The mode of action of ivabradine on the two channels is discussed by implementing a simplified version of a previously developed model of f-channel kinetics.
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Affiliation(s)
- A Bucchi
- Laboratory of Molecular Physiology and Neurobiology, Department of Biomolecular Sciences and Biotechnology, University of Milano, Italy
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Baruscotti M, Bucchi A, Difrancesco D. Physiology and pharmacology of the cardiac pacemaker (“funny”) current. Pharmacol Ther 2005; 107:59-79. [PMID: 15963351 DOI: 10.1016/j.pharmthera.2005.01.005] [Citation(s) in RCA: 245] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2005] [Accepted: 01/26/2005] [Indexed: 12/19/2022]
Abstract
First described over a quarter of a century ago, the cardiac pacemaker "funny" (I(f)) current has been extensively characterized since, and its role in cardiac pacemaking has been thoroughly demonstrated. A similar current, termed I(h), was later described in different types of neurons, where it has a variety of functions and contributes to the control of cell excitability and plasticity. I(f) is an inward current activated by both voltage hyperpolarization and intracellular cAMP. In the heart, as well as generating spontaneous activity, f-channels mediate autonomic-dependent modulation of heart rate: beta-adrenergic stimulation accelerates, and vagal stimulation slows, cardiac rate by increasing and decreasing, respectively, the intracellular cAMP concentration and, consequently, the f-channel degree of activation. Four isoforms of hyperpolarization-activated, cyclic nucleotide-gated (HCN) channels have been cloned more recently and shown to be the molecular correlates of native f-channels in the heart and h-channels in the brain. Individual HCN isoforms have kinetic and modulatory properties which differ quantitatively. A comparison of their biophysical properties with those of native pacemaker channels provides insight into the molecular basis of the pacemaker current properties and, together with immunolabelling and other detection techniques, gives information on the pattern of HCN isoform distribution in different tissues. Because of their relevance to cardiac pacemaker activity, f-channels are a natural target of drugs aimed at the pharmacological control of heart rate. Several agents developed for their ability to selectively reduce heart rate act by a specific inhibition of f-channel function; these substances have a potential for the treatment of diseases such as angina and heart failure. In the near future, devices based on the delivery of f-channels in situ, or of a cellular source of f-channels (biological pacemakers), will likely be developed for use in therapies for diseases of heart rhythm with the aim of replacing electronic pacemakers.
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Affiliation(s)
- Mirko Baruscotti
- Laboratory of Molecular Physiology and Neurobiology, Department of Biomolecular Sciences and Biotechnology, University of Milano, via Celoria 26, 20133 Milan, Italy
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46
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Bucchi A, Baruscotti M, Robinson RB, DiFrancesco D. I(f)-dependent modulation of pacemaker rate mediated by cAMP in the presence of ryanodine in rabbit sino-atrial node cells. J Mol Cell Cardiol 2003; 35:905-13. [PMID: 12878477 DOI: 10.1016/s0022-2828(03)00150-0] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
I(f) contributes to generation and autonomic control of spontaneous activity of cardiac pacemaker cells through a cAMP-dependent, Ca(2+)-independent mechanism of rate regulation. However, disruption of Ca(2+) release from sarcoplasmic reticulum (SR) by ryanodine (Ry) has been recently shown to slow spontaneous rate and inhibit beta-adrenergic receptor (betaAR)-induced rate acceleration, leading to the suggestion that the target of betaAR modulation of pacemaking is the intracellular Ca(2+)-regulatory process. We have investigated whether the Ry-induced decrease of betaAR rate modulation alternatively involves disruption of the betaAR-adenylate-cyclase-cAMP-I(f) mechanism. Prolonged exposure to Ry (3 microM, >2 min) slowed spontaneous rate of pacemaker cells by 29.8% via a depolarizing shift of take-off potential (TOP) without significantly changing early diastolic depolarization rate. Ry depressed rate acceleration caused by isoproterenol (Iso) (1 microM, 23.6% in control vs. 8.0%), but did not modify that caused by two membrane-permeable cAMP analogs, CPT-cAMP (300 microM, 17.7% vs. 17.3%) and Rp-cAMPs (50 microM, 18.0% vs. 20.6%). Consistent with the rate effect, exposure to Ry decreased the shift induced by Iso, but not that induced by either cAMP analog on the I(f)-activation curve. We conclude that disruption of Ry receptor function and SR Ca(2+) release depresses betaAR-induced modulation of heart rate, but does not impair cAMP-dependent rate acceleration mediated by I(f). However, abolishment of normal Ca(2+) homeostasis may result in the failure of betaAR agonists to sufficiently elevate cAMP near f-channels. The molecular basis for Ca(2+)-dependent interference in beta-adrenergic signaling remains to be determined.
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Affiliation(s)
- Annalisa Bucchi
- Department of General Physiology and Biochemistry, Laboratory of Molecular Physiology and Neurobiology, University of Milan, via Celoria 26, Milano 20133, Italy
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Qu J, Altomare C, Bucchi A, DiFrancesco D, Robinson RB. Functional comparison of HCN isoforms expressed in ventricular and HEK 293 cells. Pflugers Arch 2002; 444:597-601. [PMID: 12194012 DOI: 10.1007/s00424-002-0860-7] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2002] [Accepted: 04/09/2002] [Indexed: 10/27/2022]
Abstract
Pacemaker current (I(f)) encoded by the HCN gene family contributes importantly to cardiac rhythm. That contribution depends on the biophysical characteristics of I(f), such as voltage dependence, which vary markedly with cardiac region, development and disease. Heterologous expression studies of individual HCN isoforms have failed to account for the diverse functionality of the native current. To investigate the influence of cellular environment on the gating of HCN channels, we compared the functional characteristics of HCN2 and HCN4, the two major ventricular isoforms, when over-expressed in a normal context (neonatal myocytes) and in a heterologous context (HEK 293 cells). Independent of cell type, HCN4 activates substantially slower than HCN2 and with a half-maximum activation voltage approximately equal 10 mV less negative. However, both isoforms activate more positively in myocytes than in HEK 293 cells. The latter result suggests a context dependence (i.e. cell-type specificity) to HCN voltage dependence that exerts a comparable influence on these two isoforms. This is distinct from the inherent difference in the biophysical properties of HCN2 and HCN4.
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Affiliation(s)
- Jihong Qu
- Department of Pharmacology and Center for Molecular Therapeutics, Columbia University, 630W 168th St., New York, NY 10032, USA
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48
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Bucchi A, Baruscotti M, DiFrancesco D. Current-dependent block of rabbit sino-atrial node I(f) channels by ivabradine. J Gen Physiol 2002; 120:1-13. [PMID: 12084770 PMCID: PMC2238187 DOI: 10.1085/jgp.20028593] [Citation(s) in RCA: 189] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2002] [Revised: 04/29/2002] [Accepted: 05/06/2002] [Indexed: 11/30/2022] Open
Abstract
"Funny" (f-) channels have a key role in generation of spontaneous activity of pacemaker cells and mediate autonomic control of cardiac rate; f-channels and the related neuronal h-channels are composed of hyperpolarization-activated, cyclic nucleotide-gated (HCN) channel subunits. We have investigated the block of f-channels of rabbit cardiac sino-atrial node cells by ivabradine, a novel heart rate-reducing agent. Ivabradine is an open-channel blocker; however, block is exerted preferentially when channels deactivate on depolarization, and is relieved by long hyperpolarizing steps. These features give rise to use-dependent behavior. In this, the action of ivabradine on f-channels is similar to that reported of other rate-reducing agents such as UL-FS49 and ZD7288. However, other features of ivabradine-induced block are peculiar and do not comply with the hypothesis that the voltage-dependence of block is entirely attributable to either the sensitivity of ivabradine-charged molecules to the electrical field in the channel pore, or to differential affinity to different channel states, as has been proposed for UL-FS49 (DiFrancesco, D. 1994. Pflugers Arch. 427:64-70) and ZD7288 (Shin, S.K., B.S. Rotheberg, and G. Yellen. 2001. J. Gen. Physiol. 117:91-101), respectively. Experiments where current flows through channels is modified without changing membrane voltage reveal that the ivabradine block depends on the current driving force, rather than voltage alone, a feature typical of block induced in inwardly rectifying K(+) channels by intracellular cations. Bound drug molecules do not detach from the binding site in the absence of inward current through channels, even if channels are open and the drug is therefore not "trapped" by closed gates. Our data suggest that permeation through f-channel pores occurs according to a multiion, single-file mechanism, and that block/unblock by ivabradine is coupled to ionic flow. The use-dependence resulting from specific features of I(f) block by ivabradine amplifies its rate-reducing ability at high spontaneous rates and may be useful to clinical applications.
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Affiliation(s)
- Annalisa Bucchi
- Department of General Physiology and Biochemistry, Laboratory of Molecular Physiology and Neurobiology, and INFM-Unità Milano Università, 20133 Milano, Italy
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49
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Viscomi C, Altomare C, Bucchi A, Camatini E, Baruscotti M, Moroni A, DiFrancesco D. C terminus-mediated control of voltage and cAMP gating of hyperpolarization-activated cyclic nucleotide-gated channels. J Biol Chem 2001; 276:29930-4. [PMID: 11397812 DOI: 10.1074/jbc.m103971200] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The hyperpolarization-activated cyclic nucleotide-gated (HCN) family of "pacemaker" channels includes 4 isoforms, the kinetics and cAMP-induced modulation of which differ quantitatively. Because HCN isoforms are highly homologous in the central region, but diverge more substantially in the N and C termini, we asked whether these latter regions could contribute to the determination of channel properties. To this aim, we analyzed activation/deactivation kinetics and the response to cAMP of heterologously expressed isoforms mHCN1 and rbHCN4 and verified that mHCN1 has much faster kinetics and lower cAMP sensitivity than rbHCN4. We then constructed rbHCN4 chimeras by replacing either the N or the C terminus, or both, with the analogous domains from mHCN1. We found that: 1) replacement of the N terminus (chimera N1-4) did not substantially modify either the kinetics or cAMP dependence of wild-type channels; 2) replacement of the C terminus, on the contrary, resulted in a chimeric channel (4-C1), the kinetics of which were strongly accelerated compared with rbHCN4, and that was fully insensitive to cAMP; 3) replacement of both N and C termini led to the same results as replacement of the C terminus alone. These results indicate that the C terminus of rbHCN4 contributes to the regulation of voltage- and cAMP-dependent channel gating, possibly through interaction with other intracellular regions not belonging to the N terminus.
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Affiliation(s)
- C Viscomi
- Dipartimento di Fisiologia e Biochimica Generali, Laboratorio Fisiologia Molecolare e Neurobiologia, and INFM, Unità Milano Università, via Celoria 26, 20133 Milano, Italy
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50
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Abstract
Hyperpolarization-activated (pacemaker) channels are dually gated by negative voltage and intracellular cAMP. Kinetics of native cardiac f-channels are not compatible with HH gating, and require closed/open multistate models. We verified that members of the HCN channel family (mHCN1, hHCN2, hHCN4) also have properties not complying with HH gating, such as sigmoidal activation and deactivation, activation deviating from fixed power of an exponential, removal of activation "delay" by preconditioning hyperpolarization. Previous work on native channels has indicated that the shifting action of cAMP on the open probability (Po) curve can be accounted for by an allosteric model, whereby cAMP binds more favorably to open than closed channels. We therefore asked whether not only cAMP-dependent, but also voltage-dependent gating of hyperpolarization-activated channels could be explained by an allosteric model. We hypothesized that HCN channels are tetramers and that each subunit comprises a voltage sensor moving between "reluctant" and "willing" states, whereas voltage sensors are independently gated by voltage, channel closed/open transitions occur allosterically. These hypotheses led to a multistate scheme comprising five open and five closed channel states. We estimated model rate constants by fitting first activation delay curves and single exponential time constant curves, and then individual activation/deactivation traces. By simply using different sets of rate constants, the model accounts for qualitative and quantitative aspects of voltage gating of all three HCN isoforms investigated, and allows an interpretation of the different kinetic properties of different isoforms. For example, faster kinetics of HCN1 relative to HCN2/HCN4 are attributable to higher HCN1 voltage sensors' rates and looser voltage-independent interactions between subunits in closed/open transitions. It also accounts for experimental evidence that reduction of sensors' positive charge leads to negative voltage shifts of Po curve, with little change of curve slope. HCN voltage gating thus involves two processes: voltage sensor gating and allosteric opening/closing.
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Affiliation(s)
- C Altomare
- Dipartimento di Fisiologia e Biochimica Generali, via Celoria 26, and INFM-Unità Milano Università, via Celoria 16, 20133 Milano, Italy
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