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Sykora M, Kratky V, Cervenka L, Kopkan L, Tribulova N, Szeiffova Bacova B. The treatment with trandolapril and losartan attenuates pressure and volume overload alternations of cardiac connexin-43 and extracellular matrix in Ren-2 transgenic rats. Sci Rep 2023; 13:20923. [PMID: 38017033 PMCID: PMC10684879 DOI: 10.1038/s41598-023-48259-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Accepted: 11/24/2023] [Indexed: 11/30/2023] Open
Abstract
Heart failure (HF) is life-threatening disease due to electro-mechanical dysfunction associated with hemodynamic overload, while alterations of extracellular matrix (ECM) along with perturbed connexin-43 (Cx43) might be key factors involved. We aimed to explore a dual impact of pressure, and volume overload due to aorto-caval fistula (ACF) on Cx43 and ECM as well as effect of renin-angiotensin blockade. Hypertensive Ren-2 transgenic rats (TGR) and normotensive Hannover Sprague-Dawley rats (HSD) that underwent ACF were treated for 15-weeks with trandolapril or losartan. Blood serum and heart tissue samples of the right (RV) and left ventricles (LV) were used for analyses. ACF-HF increased RV, LV and lung mass in HSD and to lesser extent in TGR, while treatment attenuated it and normalized serum ANP, BNP-45 and TBARS. Cx43 protein and its ser368 variant along with PKCε were lower in TGR vs HSD and suppressed in both rat strains due to ACF but prevented more by trandolapril. Pro-hypertrophic PKCδ, collagen I and hydroxyproline were elevated in TGR and increased due to ACF in both rat strains. While SMAD2/3 and MMP2 levels were lower in TGR vs HSD and reduced due to ACF in both strains. Findings point out the strain-related differences in response to volume overload. Disorders of Cx43 and ECM signalling may contribute not only to HF but also to the formation of arrhythmogenic substrate. There is benefit of treatment with trandolapril and losartan indicating their pleiotropic anti-arrhythmic potential. It may provide novel input to therapy.
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Affiliation(s)
- Matus Sykora
- Centre of Experimental Medicine, Institute for Heart Research, Slovak Academy of Sciences, 841 04, Bratislava, Slovakia
| | - Vojtech Kratky
- Center for Experimental Medicine, Institute for Clinical and Experimental Medicine, 140 21, Prague, Czech Republic
- Department of Nephrology, First Faculty of Medicine, Charles University and General University Hospital in Prague, 128 08, Prague, Czech Republic
| | - Ludek Cervenka
- Center for Experimental Medicine, Institute for Clinical and Experimental Medicine, 140 21, Prague, Czech Republic
- Department of Internal Medicine I, Cardiology, University Hospital Olomouc and Palacky University, Olomouc, Czech Republic
| | - Libor Kopkan
- Center for Experimental Medicine, Institute for Clinical and Experimental Medicine, 140 21, Prague, Czech Republic
| | - Narcis Tribulova
- Centre of Experimental Medicine, Institute for Heart Research, Slovak Academy of Sciences, 841 04, Bratislava, Slovakia
| | - Barbara Szeiffova Bacova
- Centre of Experimental Medicine, Institute for Heart Research, Slovak Academy of Sciences, 841 04, Bratislava, Slovakia.
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Szeiffova Bacova B, Andelova K, Sykora M, T EB, Kurahara LH, Slezak J, Tribulova N. Distinct Cardiac Connexin-43 Expression in Hypertrophied and Atrophied Myocardium May Impact the Vulnerability of the Heart to Malignant Arrhythmias. A Pilot Study. Physiol Res 2023; 72:S37-S45. [PMID: 37294117 DOI: 10.33549/physiolres.935025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/23/2023] Open
Abstract
Our and other studies suggest that myocardial hypertrophy in response to hypertension and hyperthyroidism increases propensity of the heart to malignant arrhythmias, while these are rare in conditions of hypothyroidism or type-1 diabetes mellitus associated with myocardial atrophy. One of the crucial factors impacting the susceptibility of the heart to life-threatening arrhythmias is gap junction channel protein connexin-43 (Cx43), which ensure cell-to-cell coupling for electrical signal propagation. Therefore, we aimed to explore Cx43 protein abundance and its topology in hypertrophic and hypotrophic cardiac phenotype. Analysis were performed in left ventricular tissue of adult male spontaneously hypertensive rat (SHR), Wistar Kyoto rats treated for 8-weeks with L-thyroxine, methimazol or strepotozotocin to induce hyperthyroid, hypothyroid and type-1 diabetic status as well as non-treated animals. Results showed that comparing to healthy rats there was a decrease of total myocardial Cx43 and its variant phosphorylated at serine368 in SHR and hyperthyroid rats. Besides, enhanced localization of Cx43 was demonstrated on lateral sides of hypertrophied cardiomyocytes. In contrast, total Cx43 protein and its serine368 variant were increased in atrophied left ventricle of hypothyroid and type-1 diabetic rats. It was associated with less pronounced alterations in Cx43 topology. In parallel, the abundance of PKCepsilon, which phosphorylates Cx43 at serine368 that stabilize Cx43 function and distribution was reduced in hypertrophied heart while enhanced in atrophied once. Findings suggest that differences in the abundance of cardiac Cx43, its variant phosphorylated at serine368 and Cx43 topology may explain, in part, distinct propensity of hypertrophied and atrophied heart to malignant arrhythmias.
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Affiliation(s)
- B Szeiffova Bacova
- Centre of Experimental Medicine, Slovak Academy of Sciences, Bratislava, Slovak Republic.
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Sykora M, Andelova K, Szeiffova Bacova B, Egan Benova T, Martiskova A, Knezl V, Tribulova N. Hypertension Induces Pro-arrhythmic Cardiac Connexome Disorders: Protective Effects of Treatment. Biomolecules 2023; 13:biom13020330. [PMID: 36830700 PMCID: PMC9953310 DOI: 10.3390/biom13020330] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2022] [Revised: 01/16/2023] [Accepted: 01/21/2023] [Indexed: 02/11/2023] Open
Abstract
Prolonged population aging and unhealthy lifestyles contribute to the progressive prevalence of arterial hypertension. This is accompanied by low-grade inflammation and over time results in heart dysfunction and failure. Hypertension-induced myocardial structural and ion channel remodeling facilitates the development of both atrial and ventricular fibrillation, and these increase the risk of stroke and sudden death. Herein, we elucidate hypertension-induced impairment of "connexome" cardiomyocyte junctions. This complex ensures cell-to-cell adhesion and coupling for electrical and molecular signal propagation. Connexome dysfunction can be a key factor in promoting the occurrence of both cardiac arrhythmias and heart failure. However, the available literature indicates that arterial hypertension treatment can hamper myocardial structural remodeling, hypertrophy and/or fibrosis, and preserve connexome function. This suggests the pleiotropic effects of antihypertensive agents, including anti-inflammatory. Therefore, further research is required to identify specific molecular targets and pathways that will protect connexomes, and it is also necessary to develop new approaches to maintain heart function in patients suffering from primary or pulmonary arterial hypertension.
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Cardiac Cx43 Signaling Is Enhanced and TGF-β1/SMAD2/3 Suppressed in Response to Cold Acclimation and Modulated by Thyroid Status in Hairless SHRM. Biomedicines 2022; 10:biomedicines10071707. [PMID: 35885012 PMCID: PMC9313296 DOI: 10.3390/biomedicines10071707] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2022] [Revised: 07/06/2022] [Accepted: 07/07/2022] [Indexed: 12/04/2022] Open
Abstract
The hearts of spontaneously hypertensive rats (SHR) are prone to malignant arrhythmias, mainly due to disorders of electrical coupling protein Cx43 and the extracellular matrix. Cold acclimation may induce cardio-protection, but the underlying mechanisms remain to be elucidated. We aimed to explore whether the adaptation of 9-month-old hairless SHRM to cold impacts the fundamental cardiac pro-arrhythmia factors, as well as the response to the thyroid status. There were no significant differences in the registered biometric, redox and blood lipids parameters between hairless (SHRM) and wild type SHR. Prominent findings revealed that myocardial Cx43 and its variant phosphorylated at serine 368 were increased, while an abnormal cardiomyocyte Cx43 distribution was attenuated in hairless SHRM vs. wild type SHR males and females. Moreover, the level of β-catenin, ensuring mechanoelectrical coupling, was increased as well, while extracellular matrix collagen-1 and hydroxyproline were lower and the TGF-β1 and SMAD2/3 pathway was suppressed in hairless SHRM males compared to the wild type strain. Of interest, the extracellular matrix remodeling was less pronounced in females of both hypertensive strains. There were no apparent differences in response to the hypothyroid or hyperthyroid status between SHR strains concerning the examined markers. Our findings imply that hairless SHRM benefit from cold acclimation due to the attenuation of the hypertension-induced adverse downregulation of Cx43 and upregulation of extracellular matrix proteins.
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Marazzato J, Blasi F, Golino M, Verdecchia P, Angeli F, De Ponti R. Hypertension and Arrhythmias: A Clinical Overview of the Pathophysiology-Driven Management of Cardiac Arrhythmias in Hypertensive Patients. J Cardiovasc Dev Dis 2022; 9:jcdd9040110. [PMID: 35448086 PMCID: PMC9025699 DOI: 10.3390/jcdd9040110] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Revised: 03/26/2022] [Accepted: 04/02/2022] [Indexed: 02/06/2023] Open
Abstract
Because of demographic aging, the prevalence of arterial hypertension (HTN) and cardiac arrhythmias, namely atrial fibrillation (AF), is progressively increasing. Not only are these clinical entities strongly connected, but, acting with a synergistic effect, their association may cause a worse clinical outcome in patients already at risk of ischemic and/or haemorrhagic stroke and, consequently, disability and death. Despite the well-known association between HTN and AF, several pathogenetic mechanisms underlying the higher risk of AF in hypertensive patients are still incompletely known. Although several trials reported the overall clinical benefit of renin–angiotensin–aldosterone inhibitors in reducing incident AF in HTN, the role of this class of drugs is greatly reduced when AF diagnosis is already established, thus hinting at the urgent need for primary prevention measures to reduce AF occurrence in these patients. Through a thorough review of the available literature in the field, we investigated the basic mechanisms through which HTN is believed to promote AF, summarising the evidence supporting a pathophysiology-driven approach to prevent this arrhythmia in hypertensive patients, including those suffering from primary aldosteronism, a non-negligible and under-recognised cause of secondary HTN. Finally, in the hazy scenario of AF screening in hypertensive patients, we reviewed which patients should be screened, by which modality, and who should be offered oral anticoagulation for stroke prevention.
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Affiliation(s)
- Jacopo Marazzato
- Department of Medicine and Surgery, University of Insubria, 21100 Varese, Italy; (J.M.); (F.B.); (M.G.); (F.A.)
| | - Federico Blasi
- Department of Medicine and Surgery, University of Insubria, 21100 Varese, Italy; (J.M.); (F.B.); (M.G.); (F.A.)
| | - Michele Golino
- Department of Medicine and Surgery, University of Insubria, 21100 Varese, Italy; (J.M.); (F.B.); (M.G.); (F.A.)
| | - Paolo Verdecchia
- Fondazione Umbra Cuore e Ipertensione-ONLUS, 06100 Perugia, Italy;
- Division of Cardiology, Hospital S. Maria della Misericordia, 06100 Perugia, Italy
| | - Fabio Angeli
- Department of Medicine and Surgery, University of Insubria, 21100 Varese, Italy; (J.M.); (F.B.); (M.G.); (F.A.)
- Department of Medicine and Cardiopulmonary Rehabilitation, Maugeri Care and Research Institute, IRCCS Tradate, 21049 Tradate, Italy
| | - Roberto De Ponti
- Department of Medicine and Surgery, University of Insubria, 21100 Varese, Italy; (J.M.); (F.B.); (M.G.); (F.A.)
- Correspondence: ; Tel.: +39-0332278934
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Andelova K, Bacova BS, Sykora M, Hlivak P, Barancik M, Tribulova N. Mechanisms Underlying Antiarrhythmic Properties of Cardioprotective Agents Impacting Inflammation and Oxidative Stress. Int J Mol Sci 2022; 23:1416. [PMID: 35163340 PMCID: PMC8835881 DOI: 10.3390/ijms23031416] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Revised: 01/21/2022] [Accepted: 01/25/2022] [Indexed: 01/27/2023] Open
Abstract
The prevention of cardiac life-threatening ventricular fibrillation and stroke-provoking atrial fibrillation remains a serious global clinical issue, with ongoing need for novel approaches. Numerous experimental and clinical studies suggest that oxidative stress and inflammation are deleterious to cardiovascular health, and can increase heart susceptibility to arrhythmias. It is quite interesting, however, that various cardio-protective compounds with antiarrhythmic properties are potent anti-oxidative and anti-inflammatory agents. These most likely target the pro-arrhythmia primary mechanisms. This review and literature-based analysis presents a realistic view of antiarrhythmic efficacy and the molecular mechanisms of current pharmaceuticals in clinical use. These include the sodium-glucose cotransporter-2 inhibitors used in diabetes treatment, statins in dyslipidemia and naturally protective omega-3 fatty acids. This approach supports the hypothesis that prevention or attenuation of oxidative and inflammatory stress can abolish pro-arrhythmic factors and the development of an arrhythmia substrate. This could prove a powerful tool of reducing cardiac arrhythmia burden.
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Affiliation(s)
- Katarina Andelova
- Centre of Experimental Medicine, Slovak Academy of Sciences, Institute for Heart Research, Dúbravská Cesta 9, 84104 Bratislava, Slovakia; (K.A.); (M.S.); (M.B.)
| | - Barbara Szeiffova Bacova
- Centre of Experimental Medicine, Slovak Academy of Sciences, Institute for Heart Research, Dúbravská Cesta 9, 84104 Bratislava, Slovakia; (K.A.); (M.S.); (M.B.)
| | - Matus Sykora
- Centre of Experimental Medicine, Slovak Academy of Sciences, Institute for Heart Research, Dúbravská Cesta 9, 84104 Bratislava, Slovakia; (K.A.); (M.S.); (M.B.)
| | - Peter Hlivak
- Department of Arrhythmias and Pacing, National Institute of Cardiovascular Diseases, Pod Krásnou Hôrkou 1, 83348 Bratislava, Slovakia;
| | - Miroslav Barancik
- Centre of Experimental Medicine, Slovak Academy of Sciences, Institute for Heart Research, Dúbravská Cesta 9, 84104 Bratislava, Slovakia; (K.A.); (M.S.); (M.B.)
| | - Narcis Tribulova
- Centre of Experimental Medicine, Slovak Academy of Sciences, Institute for Heart Research, Dúbravská Cesta 9, 84104 Bratislava, Slovakia; (K.A.); (M.S.); (M.B.)
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Omacor Protects Normotensive and Hypertensive Rats Exposed to Continuous Light from Increased Risk to Malignant Cardiac Arrhythmias. Mar Drugs 2021; 19:md19120659. [PMID: 34940658 PMCID: PMC8709333 DOI: 10.3390/md19120659] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Revised: 11/22/2021] [Accepted: 11/23/2021] [Indexed: 12/13/2022] Open
Abstract
Light pollution disturbs circadian rhythm, and this can also be deleterious to the heart by increased susceptibility to arrhythmias. Herein, we investigated if rats exposed to continuous light had altered myocardial gene transcripts and/or protein expression which affects arrhythmogenesis. We then assessed if Omacor® supplementation benefitted affected rats. Male and female spontaneously hypertensive (SHR) and normotensive Wistar rats (WR) were housed under standard 12 h/12 h light/dark cycles or exposed to 6-weeks continuous 300 lux light for 24 h. Half the rats were then treated with 200 mg/100 g b.w. Omacor®. Continuous light resulted in higher male rat vulnerability to malignant ventricular fibrillation (VF). This was linked with myocardial connexin-43 (Cx43) down-regulation and deteriorated intercellular electrical coupling, due in part to increased pro-inflammatory NF-κB and iNOS transcripts and decreased sarcoplasmic reticulum Ca2+ATPase transcripts. Omacor® treatment increased the electrical threshold to induce the VF linked with amelioration of myocardial Cx43 mRNA and Cx43 protein levels and the suppression of NF-κB and iNOS. This indicates that rat exposure to continuous light results in deleterious cardiac alterations jeopardizing intercellular Cx43 channel-mediated electrical communication, thereby increasing the risk of malignant arrhythmias. The adverse effects were attenuated by treatment with Omacor®, thus supporting its potential benefit and the relevance of monitoring omega-3 index in human populations at risk.
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Zekios KC, Mouchtouri ET, Lekkas P, Nikas DN, Kolettis TM. Sympathetic Activation and Arrhythmogenesis after Myocardial Infarction: Where Do We Stand? J Cardiovasc Dev Dis 2021; 8:jcdd8050057. [PMID: 34063477 PMCID: PMC8156099 DOI: 10.3390/jcdd8050057] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Revised: 04/30/2021] [Accepted: 05/12/2021] [Indexed: 12/11/2022] Open
Abstract
Myocardial infarction often leads to progressive structural and electrophysiologic remodeling of the left ventricle. Despite the widespread use of β-adrenergic blockade and implantable defibrillators, morbidity and mortality from chronic-phase ventricular tachyarrhythmias remains high, calling for further investigation on the underlying pathophysiology. Histological and functional studies have demonstrated extensive alterations of sympathetic nerve endings at the peri-infarct area and flow-innervation mismatches that create a highly arrhythmogenic milieu. Such accumulated evidence, along with the previously well-documented autonomic dysfunction as an important contributing factor, has stirred intense research interest for pharmacologic and non-pharmacologic neuromodulation in post-infarction heart failure. In this regard, aldosterone inhibitors, sacubitril/valsartan and sodium-glucose cotransporter type 2 inhibitors have shown antiarrhythmic effects. Non-pharmacologic modalities, currently tested in pre-clinical and clinical trials, include transcutaneous vagal stimulation, stellate ganglion modulation and renal sympathetic denervation. In this review, we provide insights on the pathophysiology of ventricular arrhythmogenesis post-myocardial infarction, focusing on sympathetic activation.
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Affiliation(s)
- Konstantinos C. Zekios
- 1st Department of Cardiology, University Hospital of Ioannina, 1 St. Niarxou Avenue, 45500 Ioannina, Greece; (K.C.Z.); (D.N.N.)
- Department of Cardiology, University of Ioannina, 1 St. Niarxou Avenue, 45500 Ioannina, Greece;
| | - Eleni-Taxiarchia Mouchtouri
- Department of Cardiology, University of Ioannina, 1 St. Niarxou Avenue, 45500 Ioannina, Greece;
- Cardiovascular Research Institute, 1 St. Niarxou Avenue, 45500 Ioannina, Greece;
| | - Panagiotis Lekkas
- Cardiovascular Research Institute, 1 St. Niarxou Avenue, 45500 Ioannina, Greece;
| | - Dimitrios N. Nikas
- 1st Department of Cardiology, University Hospital of Ioannina, 1 St. Niarxou Avenue, 45500 Ioannina, Greece; (K.C.Z.); (D.N.N.)
| | - Theofilos M. Kolettis
- 1st Department of Cardiology, University Hospital of Ioannina, 1 St. Niarxou Avenue, 45500 Ioannina, Greece; (K.C.Z.); (D.N.N.)
- Department of Cardiology, University of Ioannina, 1 St. Niarxou Avenue, 45500 Ioannina, Greece;
- Cardiovascular Research Institute, 1 St. Niarxou Avenue, 45500 Ioannina, Greece;
- Correspondence:
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Ning B, Zhang F, Song X, Hao Q, Li Y, Li R, Dang Y. Cardiac contractility modulation attenuates structural and electrical remodeling in a chronic heart failure rabbit model. J Int Med Res 2021; 48:300060520962910. [PMID: 33044118 PMCID: PMC7556184 DOI: 10.1177/0300060520962910] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Background Cardiac contractility modulation (CCM) is non-excitatory electrical stimulation for improving cardiac function. This study aimed to evaluate the effects of CCM on structural and electrical remodeling in a rabbit model of chronic heart failure (CHF). Methods Thirty rabbits were randomly divided into the sham, CHF, and CCM groups. The CHF model was induced 12 weeks after trans-aortic constriction by pressure unloading and CCM was delivered to the myocardium for 4 weeks. Corrected QT intervals, the ventricular effective refractory period, and inducibility of ventricular tachycardia were measured by an electrophysiological examination. Connective tissue growth factor, galectin-3, Kv4.3, KCNQ1, KCNH2, and connexin 43 protein levels were measured by western blotting. Results The CHF group had a significantly prolonged corrected QT interval and ventricular effective refractory period, and increased inducibility of ventricular tachycardia. Prominent myocardial fibrosis and increased hydroxyproline content were observed in the CHF group, but these were suppressed in the CCM group. Kv4.3, KCNQ1, KCNH2, and connexin 43 protein levels were significantly lower in the CHF group, but treatment with CCM partially restored their levels. Conclusions CCM attenuates myocardial structural and electrical remodeling during CHF. These findings provide evidence for clinical use of CCM in treating CHF.
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Affiliation(s)
- Bin Ning
- Department of Cardiology, The People's Hospital of Fuyang, Fuyang, Anhui Province, People's Republic of China
| | - Feifei Zhang
- Department of Cardiology, Hebei General Hospital, Shijiazhuang, Hebei Province, People's Republic of China
| | - Xuelian Song
- Department of Cardiology, Hebei General Hospital, Shijiazhuang, Hebei Province, People's Republic of China
| | - Qingqing Hao
- Department of Cardiology, Hebei General Hospital, Shijiazhuang, Hebei Province, People's Republic of China
| | - Yingxiao Li
- Department of Cardiology, Hebei General Hospital, Shijiazhuang, Hebei Province, People's Republic of China
| | - Rong Li
- Department of Cardiology, Hebei General Hospital, Shijiazhuang, Hebei Province, People's Republic of China
| | - Yi Dang
- Department of Cardiology, Hebei General Hospital, Shijiazhuang, Hebei Province, People's Republic of China
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Andelova K, Egan Benova T, Szeiffova Bacova B, Sykora M, Prado NJ, Diez ER, Hlivak P, Tribulova N. Cardiac Connexin-43 Hemichannels and Pannexin1 Channels: Provocative Antiarrhythmic Targets. Int J Mol Sci 2020; 22:ijms22010260. [PMID: 33383853 PMCID: PMC7795512 DOI: 10.3390/ijms22010260] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Revised: 12/23/2020] [Accepted: 12/24/2020] [Indexed: 12/12/2022] Open
Abstract
Cardiac connexin-43 (Cx43) creates gap junction channels (GJCs) at intercellular contacts and hemi-channels (HCs) at the peri-junctional plasma membrane and sarcolemmal caveolae/rafts compartments. GJCs are fundamental for the direct cardiac cell-to-cell transmission of electrical and molecular signals which ensures synchronous myocardial contraction. The HCs and structurally similar pannexin1 (Panx1) channels are active in stressful conditions. These channels are essential for paracrine and autocrine communication through the release of ions and signaling molecules to the extracellular environment, or for uptake from it. The HCs and Panx1 channel-opening profoundly affects intracellular ionic homeostasis and redox status and facilitates via purinergic signaling pro-inflammatory and pro-fibrotic processes. These conditions promote cardiac arrhythmogenesis due to the impairment of the GJCs and selective ion channel function. Crosstalk between GJCs and HCs/Panx1 channels could be crucial in the development of arrhythmogenic substrates, including fibrosis. Despite the knowledge gap in the regulation of these channels, current evidence indicates that HCs and Panx1 channel activation can enhance the risk of cardiac arrhythmias. It is extremely challenging to target HCs and Panx1 channels by inhibitory agents to hamper development of cardiac rhythm disorders. Progress in this field may contribute to novel therapeutic approaches for patients prone to develop atrial or ventricular fibrillation.
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Affiliation(s)
- Katarina Andelova
- Centre of Experimental Medicine, Slovak Academy of Sciences, Institute for Heart Research, 84104 Bratislava, Slovakia; (K.A.); (T.E.B.); (B.S.B.); (M.S.)
| | - Tamara Egan Benova
- Centre of Experimental Medicine, Slovak Academy of Sciences, Institute for Heart Research, 84104 Bratislava, Slovakia; (K.A.); (T.E.B.); (B.S.B.); (M.S.)
| | - Barbara Szeiffova Bacova
- Centre of Experimental Medicine, Slovak Academy of Sciences, Institute for Heart Research, 84104 Bratislava, Slovakia; (K.A.); (T.E.B.); (B.S.B.); (M.S.)
| | - Matus Sykora
- Centre of Experimental Medicine, Slovak Academy of Sciences, Institute for Heart Research, 84104 Bratislava, Slovakia; (K.A.); (T.E.B.); (B.S.B.); (M.S.)
| | - Natalia Jorgelina Prado
- Instituto de Medicina y Biología Experimental de Cuyo, Consejo Nacional de Investigaciones Científicas y Técnicas, M5500 Mendoza, Argentina; (N.J.P.); (E.R.D.)
| | - Emiliano Raul Diez
- Instituto de Medicina y Biología Experimental de Cuyo, Consejo Nacional de Investigaciones Científicas y Técnicas, M5500 Mendoza, Argentina; (N.J.P.); (E.R.D.)
| | - Peter Hlivak
- Department of Arrhythmias and Pacing, National Institute of Cardiovascular Diseases, Pod Krásnou Hôrkou 1, 83348 Bratislava, Slovakia;
| | - Narcis Tribulova
- Centre of Experimental Medicine, Slovak Academy of Sciences, Institute for Heart Research, 84104 Bratislava, Slovakia; (K.A.); (T.E.B.); (B.S.B.); (M.S.)
- Correspondence: ; Tel.: +421-2-32295-423
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Moscato S, Cabiati M, Bianchi F, Panetta D, Burchielli S, Massimetti G, Del Ry S, Mattii L. Heart and liver connexin expression related to the first stage of aging: A study on naturally aged animals. Acta Histochem 2020; 122:151651. [PMID: 33171391 DOI: 10.1016/j.acthis.2020.151651] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2020] [Revised: 10/09/2020] [Accepted: 10/27/2020] [Indexed: 12/26/2022]
Abstract
Connexins are membrane-spanning proteins that form membrane channels and hemichannels. They are involved in the cellular communication and in the maintenance of tissue homeostasis. Recent studies in humans and animals have demonstrated that the expression and distribution of Cx43, the most studied connexin, can change during aging. However, the research on the involvement of the other connexins in cardiac and hepatic aging is, at present, still very poor. Hence, the aim of this study is to evaluate the expression of Cx43 and Cx26 in the heart as well as Cx26 and Cx32 in the liver of a rat model that aged naturally, rather than prematurely because of genetic mutations or age-related diseases. The results obtained in the present study have demonstrated that these connexins decrease in rat cardiomyocytes and in rat hepatocytes as they age. This change was revealed only at protein level, as connexin-mRNAs remained unchanged during aging. Moreover, the aged rats showed an increase in body fat, whose subcutaneous layer tended to be higher. Finally, how these changes could represent signs of physiological adaptation in successful aging was discussed.
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Affiliation(s)
- Stefania Moscato
- Unit of Histology and Medical Embriology, Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy; University of Pisa, Interdepartmental Research Center Nutraceuticals and Food for Health, Pisa, Italy; Italian Institute of Technology, Smart Bio-Interfaces, Pontedera (Pisa), Italy
| | - Manuela Cabiati
- Laboratory of Biochemistry and Molecular Biology, Institute of Clinical Physiology, CNR, Pisa, Italy
| | - Francesco Bianchi
- Unit of Histology and Medical Embriology, Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - Daniele Panetta
- Laboratory of Biochemistry and Molecular Biology, Institute of Clinical Physiology, CNR, Pisa, Italy
| | | | - Gabriele Massimetti
- Psychiatric Clinic, Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - Silvia Del Ry
- Laboratory of Biochemistry and Molecular Biology, Institute of Clinical Physiology, CNR, Pisa, Italy; Institute of Life Sciences, ScuolaSuperioreSant'Anna, Pisa, Italy
| | - Letizia Mattii
- Unit of Histology and Medical Embriology, Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy; University of Pisa, Interdepartmental Research Center Nutraceuticals and Food for Health, Pisa, Italy.
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Zhang Y, Hou MC, Li JJ, Qi Y, Zhang Y, She G, Ren YJ, Wu W, Pang ZD, Xie W, Deng XL, Du XJ. Cardiac β-adrenergic receptor activation mediates distinct and cell type-dependent changes in the expression and distribution of connexin 43. J Cell Mol Med 2020; 24:8505-8517. [PMID: 32578931 PMCID: PMC7412418 DOI: 10.1111/jcmm.15469] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2020] [Revised: 04/27/2020] [Accepted: 05/12/2020] [Indexed: 12/14/2022] Open
Abstract
Activation of the sympatho-β-adrenergic receptors (β-ARs) system is a hallmark of heart failure, leading to fibrosis and arrhythmias. Connexin 43 (Cx43) is the most abundant gap junctional protein in the myocardium. Current knowledge is limited regarding Cx43 remodelling in diverse cell types in the diseased myocardium and the underlying mechanism. We studied cell type-dependent changes in Cx43 remodelling due to β-AR overactivation and molecular mechanisms involved. Mouse models of isoproterenol stimulation or transgenic cardiomyocyte overexpression of β2 -AR were used, which exhibited cardiac fibrosis and up-regulated total Cx43 abundance. In both models, whereas Cx43 expression in cardiomyocytes was reduced and more laterally distributed, fibroblasts exhibited elevated Cx43 expression and enhanced gap junction communication. Mechanistically, activation of β2 -AR in fibroblasts in vitro elevated Cx43 expression, which was abolished by the β2 -antagonist ICI-118551 or protein kinase A inhibitor H-89, but simulated by the adenylyl cyclase activator forskolin. Our in vitro and in vivo data showed that β-AR activation-induced production of IL-18 sequentially stimulated Cx43 expression in fibroblasts in a paracrine fashion. In summary, our findings demonstrate a pivotal role of β-AR in mediating distinct and cell type-dependent changes in the expression and distribution of Cx43, leading to pathological gap junction remodelling in the myocardium.
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Affiliation(s)
- Yi Zhang
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an, China
| | - Meng-Chen Hou
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an, China.,Department of Pathology, Xi'an Guangren Hospital, Xi'an Jiaotong University Health Science Center, Xi'an, China
| | - Jing-Jing Li
- The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Sciences and Technology, Xi'an Jiaotong University, Xi'an, China
| | - Ying Qi
- The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Sciences and Technology, Xi'an Jiaotong University, Xi'an, China
| | - Yu Zhang
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an, China
| | - Gang She
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an, China
| | - Yu-Jie Ren
- Department of Pathology, Xi'an Guangren Hospital, Xi'an Jiaotong University Health Science Center, Xi'an, China
| | - Wei Wu
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an, China
| | - Zheng-Da Pang
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an, China
| | - Wenjun Xie
- The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Sciences and Technology, Xi'an Jiaotong University, Xi'an, China
| | - Xiu-Ling Deng
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an, China.,Key Laboratory of Environment and Genes Related to Diseases, Ministry of Education, Xi'an Jiaotong University Health Science Center, Shaanxi, China
| | - Xiao-Jun Du
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an, China.,Experimental Cardiology Laboratory, Baker Heart and Diabetes Institute, Melbourne, Australia
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13
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Szeiffova Bacova B, Viczenczova C, Andelova K, Sykora M, Chaudagar K, Barancik M, Adamcova M, Knezl V, Egan Benova T, Weismann P, Slezak J, Tribulova N. Antiarrhythmic Effects of Melatonin and Omega-3 Are Linked with Protection of Myocardial Cx43 Topology and Suppression of Fibrosis in Catecholamine Stressed Normotensive and Hypertensive Rats. Antioxidants (Basel) 2020; 9:antiox9060546. [PMID: 32580481 PMCID: PMC7346184 DOI: 10.3390/antiox9060546] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2020] [Revised: 06/16/2020] [Accepted: 06/19/2020] [Indexed: 02/07/2023] Open
Abstract
Cardiac β-adrenergic overstimulation results in oxidative stress, hypertrophy, ischemia, lesion, and fibrosis rendering the heart vulnerable to malignant arrhythmias. We aimed to explore the anti-arrhythmic efficacy of the anti-oxidative and anti-inflammatory compounds, melatonin, and omega-3, and their mechanisms of actions in normotensive and hypertensive rats exposed to isoproterenol (ISO) induced β-adrenergic overdrive. Eight-month-old, male SHR, and Wistar rats were injected during 7 days with ISO (cumulative dose, 118 mg/kg). ISO rats were either untreated or concomitantly treated with melatonin (10 mg/kg/day) or omega-3 (Omacor, 1.68 g/kg/day) until 60 days of ISO withdrawal and compared to non-ISO controls. Findings showed that both melatonin and omega-3 increased threshold current to induce ventricular fibrillation (VF) in ISO rats regardless of the strain. Prolonged treatment with these compounds resulted in significant suppression of ISO-induced extracellular matrix alterations, as indicated by reduced areas of diffuse fibrosis and decline of hydroxyproline, collagen-1, SMAD2/3, and TGF-β1 protein levels. Importantly, the highly pro-arrhythmic ISO-induced disordered cardiomyocyte distribution of electrical coupling protein, connexin-43 (Cx43), and its remodeling (lateralization) were significantly attenuated by melatonin and omega-3 in Wistar as well as SHR hearts. In parallel, both compounds prevented the post-ISO-related increase in Cx43 variant phosphorylated at serine 368 along with PKCε, which are known to modulate Cx43 remodeling. Melatonin and omega-3 increased SOD1 or SOD2 protein levels in ISO-exposed rats of both strains. Altogether, the results indicate that anti-arrhythmic effects of melatonin and omega-3 might be attributed to the protection of myocardial Cx43 topology and suppression of fibrosis in the setting of oxidative stress induced by catecholamine overdrive in normotensive and hypertensive rats.
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Affiliation(s)
- Barbara Szeiffova Bacova
- Centre of Experimental Medicine, SAS, 84104 Bratislava, Slovakia; (B.S.B.); (C.V.); (K.A.); (M.S.); (M.B.); (V.K.); (T.E.B.); (J.S.)
| | - Csilla Viczenczova
- Centre of Experimental Medicine, SAS, 84104 Bratislava, Slovakia; (B.S.B.); (C.V.); (K.A.); (M.S.); (M.B.); (V.K.); (T.E.B.); (J.S.)
- Research Center for Molecular Medicine of the Austrian Academy of Sciences, A-1090 Vienna, Austria
| | - Katarina Andelova
- Centre of Experimental Medicine, SAS, 84104 Bratislava, Slovakia; (B.S.B.); (C.V.); (K.A.); (M.S.); (M.B.); (V.K.); (T.E.B.); (J.S.)
| | - Matus Sykora
- Centre of Experimental Medicine, SAS, 84104 Bratislava, Slovakia; (B.S.B.); (C.V.); (K.A.); (M.S.); (M.B.); (V.K.); (T.E.B.); (J.S.)
| | | | - Miroslav Barancik
- Centre of Experimental Medicine, SAS, 84104 Bratislava, Slovakia; (B.S.B.); (C.V.); (K.A.); (M.S.); (M.B.); (V.K.); (T.E.B.); (J.S.)
| | - Michaela Adamcova
- Department of Physiology, Faculty of Medicine, Charles University, 50003 Hradec Kralove, Czech Republic;
| | - Vladimir Knezl
- Centre of Experimental Medicine, SAS, 84104 Bratislava, Slovakia; (B.S.B.); (C.V.); (K.A.); (M.S.); (M.B.); (V.K.); (T.E.B.); (J.S.)
| | - Tamara Egan Benova
- Centre of Experimental Medicine, SAS, 84104 Bratislava, Slovakia; (B.S.B.); (C.V.); (K.A.); (M.S.); (M.B.); (V.K.); (T.E.B.); (J.S.)
| | - Peter Weismann
- Faculty of Medicine, Comenius University, 81499 Bratislava, Slovakia;
| | - Jan Slezak
- Centre of Experimental Medicine, SAS, 84104 Bratislava, Slovakia; (B.S.B.); (C.V.); (K.A.); (M.S.); (M.B.); (V.K.); (T.E.B.); (J.S.)
| | - Narcisa Tribulova
- Centre of Experimental Medicine, SAS, 84104 Bratislava, Slovakia; (B.S.B.); (C.V.); (K.A.); (M.S.); (M.B.); (V.K.); (T.E.B.); (J.S.)
- Correspondence: ; Tel.: +00421-2-32295423
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14
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Tribulova N, Kurahara LH, Hlivak P, Hirano K, Szeiffova Bacova B. Pro-Arrhythmic Signaling of Thyroid Hormones and Its Relevance in Subclinical Hyperthyroidism. Int J Mol Sci 2020; 21:E2844. [PMID: 32325836 PMCID: PMC7215427 DOI: 10.3390/ijms21082844] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2020] [Revised: 04/06/2020] [Accepted: 04/17/2020] [Indexed: 12/18/2022] Open
Abstract
A perennial task is to prevent the occurrence and/or recurrence of most frequent or life-threatening cardiac arrhythmias such as atrial fibrillation (AF) and ventricular fibrillation (VF). VF may be lethal in cases without an implantable cardioverter defibrillator or with failure of this device. Incidences of AF, even the asymptomatic ones, jeopardize the patient's life due to its complication, notably the high risk of embolic stroke. Therefore, there has been a growing interest in subclinical AF screening and searching for novel electrophysiological and molecular markers. Considering the worldwide increase in cases of thyroid dysfunction and diseases, including thyroid carcinoma, we aimed to explore the implication of thyroid hormones in pro-arrhythmic signaling in the pathophysiological setting. The present review provides updated information about the impact of altered thyroid status on both the occurrence and recurrence of cardiac arrhythmias, predominantly AF. Moreover, it emphasizes the importance of both thyroid status monitoring and AF screening in the general population, as well as in patients with thyroid dysfunction and malignancies. Real-world data on early AF identification in relation to thyroid function are scarce. Even though symptomatic AF is rare in patients with thyroid malignancies, who are under thyroid suppressive therapy, clinicians should be aware of potential interaction with asymptomatic AF. It may prevent adverse consequences and improve the quality of life. This issue may be challenging for an updated registry of AF in clinical practice. Thyroid hormones should be considered a biomarker for cardiac arrhythmias screening and their tailored management because of their multifaceted cellular actions.
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Affiliation(s)
- Narcis Tribulova
- Centre of Experimental Medicine, Slovak Academy of Sciences, Institute for Heart Research, 84104 Bratislava, Slovakia
| | - Lin Hai Kurahara
- Department of Cardiovascular Physiology, Faculty of Medicine, Kagawa University, Kagawa 76 0793, Japan; (L.H.K.); (K.H.)
| | - Peter Hlivak
- Department of Arrhythmias and Pacing, National Institute of Cardiovascular Diseases, Pod Krásnou Hôrkou 1, 83348 Bratislava, Slovakia;
| | - Katsuya Hirano
- Department of Cardiovascular Physiology, Faculty of Medicine, Kagawa University, Kagawa 76 0793, Japan; (L.H.K.); (K.H.)
| | - Barbara Szeiffova Bacova
- Centre of Experimental Medicine, Slovak Academy of Sciences, Institute for Heart Research, 84104 Bratislava, Slovakia
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15
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Suppression of β1-Adrenoceptor Autoantibodies is Involved in the Antiarrhythmic Effects of Omega-3 Fatty Acids in Male and Female Hypertensive Rats. Int J Mol Sci 2020; 21:ijms21020526. [PMID: 31947691 PMCID: PMC7013542 DOI: 10.3390/ijms21020526] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Revised: 01/09/2020] [Accepted: 01/10/2020] [Indexed: 12/13/2022] Open
Abstract
The arrhythmogenic potential of β1-adrenoceptor autoantibodies (β1-AA), as well as antiarrhythmic properties of omega-3 in heart diseases, have been reported while underlying mechanisms are poorly understood. We aimed to test our hypothesis that omega-3 (eicosapentaenoic acid-EPA, docosahexaenoic acid-DHA) may inhibit matrix metalloproteinase (MMP-2) activity to prevent cleavage of β1-AR and formation of β1-AA resulting in attenuation of pro-arrhythmic connexin-43 (Cx43) and protein kinase C (PKC) signaling in the diseased heart. We have demonstrated that the appearance and increase of β1-AA in blood serum of male and female 12-month-old spontaneously hypertensive rats (SHR) was associated with an increase of inducible ventricular fibrillation (VF) comparing to normotensive controls. In contrast, supplementation of hypertensive rats with omega-3 for two months suppressed β1-AA levels and reduced incidence of VF. Suppression of β1-AA was accompanied by a decrease of elevated myocardial MMP-2 activity, preservation of cardiac cell membrane integrity and Cx43 topology. Moreover, omega-3 abrogated decline in expression of total Cx43 as well as its phosphorylated forms at serine 368 along with PKC-ε, while decreased pro-fibrotic PKC-δ levels in hypertensive rat heart regardless the sex. The implication of MMP-2 in the action of omega-3 was also demonstrated in cultured cardiomyocytes in which desensitization of β1-AR due to permanent activation of β1-AR with isoproterenol was prevented by MMP-2 inhibitor or EPA. Collectively, these data support the notion that omega-3 via suppression of β1-AA mechanistically controlled by MMP-2 may attenuate abnormal of Cx43 and PKC-ε signaling; thus, abolish arrhythmia substrate and protect rats with an advanced stage of hypertension from malignant arrhythmias.
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16
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Examining Cardiomyocyte Dysfunction Using Acute Chemical Induction of an Ageing Phenotype. Int J Mol Sci 2019; 21:ijms21010197. [PMID: 31892165 PMCID: PMC6982016 DOI: 10.3390/ijms21010197] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Revised: 12/21/2019] [Accepted: 12/23/2019] [Indexed: 11/18/2022] Open
Abstract
Much effort is focussed on understanding the structural and functional changes in the heart that underlie age-dependent deterioration of cardiac performance. Longitudinal studies, using aged animals, have pinpointed changes occurring to the contractile myocytes within the heart. However, whilst longitudinal studies are important, other experimental approaches are being advanced that can recapitulate the phenotypic changes seen during ageing. This study investigated the induction of an ageing cardiomyocyte phenotypic change by incubation of cells with hydroxyurea for several days ex vivo. Hydroxyurea incubation has been demonstrated to phenocopy age- and senescence-induced changes in neurons, but its utility for ageing studies with cardiac cells has not been examined. Incubation of neonatal rat ventricular myocytes with hydroxyurea for up to 7 days replicated specific aspects of cardiac ageing including reduced systolic calcium responses, increased alternans and a lesser ability of the cells to follow electrical pacing. Additional functional and structural changes were observed within the myocytes that pointed to ageing-like remodelling, including lipofuscin granule accumulation, reduced mitochondrial membrane potential, increased production of reactive oxygen species, and altered ultrastructure, such as mitochondria with disrupted cristae and disorganised myofibres. These data highlight the utility of alternative approaches for exploring cellular ageing whilst avoiding the costs and co-morbid factors that can affect longitudinal studies.
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17
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Bacharova L. Missing Link between Molecular Aspects of Ventricular Arrhythmias and QRS Complex Morphology in Left Ventricular Hypertrophy. Int J Mol Sci 2019; 21:E48. [PMID: 31861705 PMCID: PMC6982310 DOI: 10.3390/ijms21010048] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Revised: 12/17/2019] [Accepted: 12/17/2019] [Indexed: 12/27/2022] Open
Abstract
The aim of this opinion paper is to point out the knowledge gap between evidence on the molecular level and clinical diagnostic possibilities in left ventricular hypertrophy (LVH) regarding the prediction of ventricular arrhythmias and monitoring the effect of therapy. LVH is defined as an increase in left ventricular size and is associated with increased occurrence of ventricular arrhythmia. Hypertrophic rebuilding of myocardium comprises interrelated processes on molecular, subcellular, cellular, tissue, and organ levels affecting electrogenesis, creating a substrate for triggering and maintaining arrhythmias. The knowledge of these processes serves as a basis for developing targeted therapy to prevent and treat arrhythmias. In the clinical practice, the method for recording electrical phenomena of the heart is electrocardiography. The recognized clinical electrocardiogram (ECG) predictors of ventricular arrhythmias are related to alterations in electrical impulse propagation, such as QRS complex duration, QT interval, early repolarization, late potentials, and fragmented QRS, and they are not specific for LVH. However, the simulation studies have shown that the QRS complex patterns documented in patients with LVH are also conditioned remarkably by the alterations in impulse propagation. These QRS complex patterns in LVH could be potentially recognized for predicting ventricular arrhythmia and for monitoring the effect of therapy.
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Affiliation(s)
- Ljuba Bacharova
- International Laser Center, 841 04 Bratislava, Slovakia
- Institute of Pathophysiology, Medical School, Comenius University, 841 04 Bratislava, Slovakia
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18
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Cardiac Cx43 and ECM Responses to Altered Thyroid Status Are Blunted in Spontaneously Hypertensive versus Normotensive Rats. Int J Mol Sci 2019; 20:ijms20153758. [PMID: 31374823 PMCID: PMC6696036 DOI: 10.3390/ijms20153758] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2019] [Revised: 07/16/2019] [Accepted: 07/27/2019] [Indexed: 12/18/2022] Open
Abstract
Heart function and its susceptibility to arrhythmias are modulated by thyroid hormones (THs) but the responsiveness of hypertensive individuals to thyroid dysfunction is elusive. We aimed to explore the effect of altered thyroid status on crucial factors affecting synchronized heart function, i.e., connexin-43 (Cx43) and extracellular matrix proteins (ECM), in spontaneously hypertensive rats (SHRs) compared to normotensive Wistar Kyoto rats (WKRs). Basal levels of circulating THs were similar in both strains. Hyperthyroid state (HT) was induced by injection of T3 (0.15 mg/kg b.w. for eight weeks) and hypothyroid state (HY) by the administration of methimazol (0.05% for eight weeks). The possible benefit of omega-3 polyunsaturated fatty acids (Omacor, 200 mg/kg for eight weeks) intake was examined as well. Reduced levels of Cx43 in SHRs were unaffected by alterations in THs, unlike WKRs, in which levels of Cx43 and its phosphorylated form at serine368 were decreased in the HT state and increased in the HY state. This specific Cx43 phosphorylation, attributed to enhanced protein kinase C-epsilon signaling, was also increased in HY SHRs. Altered thyroid status did not show significant differences in markers of ECM or collagen deposition in SHRs. WKRs exhibited a decrease in levels of profibrotic transforming growth factor β1 and SMAD2/3 in HT and an increase in HY, along with enhanced interstitial collagen. Short-term intake of omega-3 polyunsaturated fatty acids did not affect any targeted proteins significantly. Key findings suggest that myocardial Cx43 and ECM responses to altered thyroid status are blunted in SHRs compared to WKRs. However, enhanced phosphorylation of Cx43 at serine368 in hypothyroid SHRs might be associated with preservation of intercellular coupling and alleviation of the propensity of the heart to malignant arrhythmias.
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19
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LeBaron TW, Kura B, Kalocayova B, Tribulova N, Slezak J. A New Approach for the Prevention and Treatment of Cardiovascular Disorders. Molecular Hydrogen Significantly Reduces the Effects of Oxidative Stress. Molecules 2019; 24:E2076. [PMID: 31159153 PMCID: PMC6600250 DOI: 10.3390/molecules24112076] [Citation(s) in RCA: 74] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2019] [Revised: 05/20/2019] [Accepted: 05/24/2019] [Indexed: 12/12/2022] Open
Abstract
Cardiovascular diseases are the most common causes of morbidity and mortality worldwide. Redox dysregulation and a dyshomeostasis of inflammation arise from, and result in, cellular aberrations and pathological conditions, which lead to cardiovascular diseases. Despite years of intensive research, there is still no safe and effective method for their prevention and treatment. Recently, molecular hydrogen has been investigated in preclinical and clinical studies on various diseases associated with oxidative and inflammatory stress such as radiation-induced heart disease, ischemia-reperfusion injury, myocardial and brain infarction, storage of the heart, heart transplantation, etc. Hydrogen is primarily administered via inhalation, drinking hydrogen-rich water, or injection of hydrogen-rich saline. It favorably modulates signal transduction and gene expression resulting in suppression of proinflammatory cytokines, excess ROS production, and in the activation of the Nrf2 antioxidant transcription factor. Although H2 appears to be an important biological molecule with anti-oxidant, anti-inflammatory, and anti-apoptotic effects, the exact mechanisms of action remain elusive. There is no reported clinical toxicity; however, some data suggests that H2 has a mild hormetic-like effect, which likely mediate some of its benefits. The mechanistic data, coupled with the pre-clinical and clinical studies, suggest that H2 may be useful for ROS/inflammation-induced cardiotoxicity and other conditions.
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Affiliation(s)
- Tyler W LeBaron
- Centre of Experimental Medicine, Institute for Heart Research, Slovak Academy of Sciences, Bratislava 841 04, Slovak Republic.
- Molecular Hydrogen Institute, Enoch City, UT, 847 21, USA.
| | - Branislav Kura
- Centre of Experimental Medicine, Institute for Heart Research, Slovak Academy of Sciences, Bratislava 841 04, Slovak Republic.
| | - Barbora Kalocayova
- Centre of Experimental Medicine, Institute for Heart Research, Slovak Academy of Sciences, Bratislava 841 04, Slovak Republic.
| | - Narcis Tribulova
- Centre of Experimental Medicine, Institute for Heart Research, Slovak Academy of Sciences, Bratislava 841 04, Slovak Republic.
| | - Jan Slezak
- Centre of Experimental Medicine, Institute for Heart Research, Slovak Academy of Sciences, Bratislava 841 04, Slovak Republic.
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20
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Sykora M, Kamocsaiova L, Egan Benova T, Frimmel K, Ujhazy E, Mach M, Barancik M, Tribulova N, Szeiffova Bacova B. Alterations in myocardial connexin-43 and matrix metalloproteinase-2 signaling in response to pregnancy and oxygen deprivation of Wistar rats: a pilot study 1. Can J Physiol Pharmacol 2019; 97:829-836. [PMID: 30908945 DOI: 10.1139/cjpp-2018-0740] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Two important aspects of cardiac adaptive response to pregnancy have been studied in normal as well as hypoxic conditions: (1) intercellular signaling mediated by myocardial connexin-43 (Cx43) that is crucial to synchronize heart function; (2) extracellular signaling mediated by matrix metalloproteinase-2 (MMP-2) that is an early marker of extracellular matrix remodeling. Myocardial Cx43 distribution and functional capillary density were determined as well. Hypoxia was induced by exposure of rats to 10.5% O2 and 89.5% N2 in a hermetically sealed chamber. Findings showed that pregnancy resulted in a significant increase of Cx43 protein expression, its functional phosphorylated forms, and enhanced capillary density while did not affect either expression of total MMP-2 or its activity. Maternal hypoxia for 12 or 16 h did not affect elevated Cx43 but enhanced its distribution on lateral sides of the cardiomyocytes. In contrast, hypoxia of nonpregnant rats resulted in upregulation of Cx43, its lateral distribution, and enhanced capillary density. Hypoxia did not affect myocardial MMP-2 either in pregnant or nonpregnant rats. Cardiac adaptive response to pregnancy is accompanied by enhanced Cx43 without changes in MMP-2 signaling. Pregnant rat heart is tolerant to short-term hypoxemia, while nonpregnant rat heart reacts by upregulation of Cx43 and increased capillary density.
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Affiliation(s)
- Matus Sykora
- CEM SAS, Institute for Heart Research, Bratislava, Slovakia
| | - Lucia Kamocsaiova
- Faculty of Natural Sciences of Comenius University, Bratislava, Slovakia
| | | | - Karel Frimmel
- CEM SAS, Institute for Heart Research, Bratislava, Slovakia
| | - Eduard Ujhazy
- CEM SAS, Institute of Experimental Pharmacology and Toxicology, Bratislava, Slovakia
| | - Mojmir Mach
- CEM SAS, Institute of Experimental Pharmacology and Toxicology, Bratislava, Slovakia
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21
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Egan Benova T, Viczenczova C, Szeiffova Bacova B, Knezl V, Dosenko V, Rauchova H, Zeman M, Reiter RJ, Tribulova N. Obesity-associated alterations in cardiac connexin-43 and PKC signaling are attenuated by melatonin and omega-3 fatty acids in female rats. Mol Cell Biochem 2018; 454:191-202. [PMID: 30446908 DOI: 10.1007/s11010-018-3463-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2018] [Accepted: 10/17/2018] [Indexed: 12/14/2022]
Abstract
We aimed to explore whether specific high-sucrose intake in older female rats affects myocardial electrical coupling protein, connexin-43 (Cx43), protein kinase C (PKC) signaling, miR-1 and miR-30a expression, and susceptibility of the heart to malignant arrhythmias. Possible benefit of the supplementation with melatonin (40 µg/ml/day) and omega-3 polyunsaturated fatty acids (Omacor, 25 g/kg of rat chow) was examined as well. Results have shown that 8 weeks lasting intake of 30% sucrose solution increased serum cholesterol, triglycerides, body weight, heart weight, and retroperitoneal adipose tissues. It was accompanied by downregulation of cardiac Cx43 and PKCε signaling along with an upregulation of myocardial PKCδ and miR-30a rendering the heart prone to ventricular arrhythmias. There was a clear benefit of melatonin or omega-3 PUFA supplementation due to their antiarrhythmic effects associated with the attenuation of myocardial Cx43, PKC, and miR-30a abnormalities as well as adiposity. The potential impact of these findings may be considerable, and suggests that high-sucrose intake impairs myocardial signaling mediated by Cx43 and PKC contributing to increased susceptibility of the older obese female rat hearts to malignant arrhythmias.
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Affiliation(s)
- Tamara Egan Benova
- Center of Experimental Medicine, Institute for Heart Research, Slovak Academy of Sciences, Dúbravská cesta 9, 841 04, Bartislava, Slovakia
| | - Csilla Viczenczova
- Center of Experimental Medicine, Institute for Heart Research, Slovak Academy of Sciences, Dúbravská cesta 9, 841 04, Bartislava, Slovakia
| | - Barbara Szeiffova Bacova
- Center of Experimental Medicine, Institute for Heart Research, Slovak Academy of Sciences, Dúbravská cesta 9, 841 04, Bartislava, Slovakia
| | - Vladimir Knezl
- Center of Experimental Medicine, Institute of Experimental Pharmacology and Toxicology, Slovak Academy of Sciences, Bratislava, Slovakia
| | - Victor Dosenko
- State Key Laboratory of Molecular and Cellular Biology, Bogomoletz Institute of Physiology, Kyiv, Ukraine
| | - Hana Rauchova
- Institute of Physiology of the Czech Academy of Sciences, Prague, Czech Republic
| | - Michal Zeman
- Department of Animal Physiology and Ethology, Faculty of Natural Sciences, Comenius University, Bratislava, Slovakia
| | - Russel J Reiter
- Department of Cellular and Structural Biology, UT Health Science Center, San Antonio, 78229, TX, USA
| | - Narcis Tribulova
- Center of Experimental Medicine, Institute for Heart Research, Slovak Academy of Sciences, Dúbravská cesta 9, 841 04, Bartislava, Slovakia.
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22
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Overexpression of Cx43 in cells of the myocardial scar: Correction of post-infarct arrhythmias through heterotypic cell-cell coupling. Sci Rep 2018; 8:7145. [PMID: 29739982 PMCID: PMC5940892 DOI: 10.1038/s41598-018-25147-8] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2017] [Accepted: 04/06/2018] [Indexed: 12/16/2022] Open
Abstract
Ventricular tachycardia (VT) is the most common and potentially lethal complication following myocardial infarction (MI). Biological correction of the conduction inhomogeneity that underlies re-entry could be a major advance in infarction therapy. As minimal increases in conduction of infarcted tissue markedly influence VT susceptibility, we reasoned that enhanced propagation of the electrical signal between non-excitable cells within a resolving infarct might comprise a simple means to decrease post-infarction arrhythmia risk. We therefore tested lentivirus-mediated delivery of the gap-junction protein Connexin 43 (Cx43) into acute myocardial lesions. Cx43 was expressed in (myo)fibroblasts and CD45+ cells within the scar and provided prominent and long lasting arrhythmia protection in vivo. Optical mapping of Cx43 injected hearts revealed enhanced conduction velocity within the scar, indicating Cx43-mediated electrical coupling between myocytes and (myo)fibroblasts. Thus, Cx43 gene therapy, by direct in vivo transduction of non-cardiomyocytes, comprises a simple and clinically applicable biological therapy that markedly reduces post-infarction VT.
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Irradiation-Induced Cardiac Connexin-43 and miR-21 Responses Are Hampered by Treatment with Atorvastatin and Aspirin. Int J Mol Sci 2018; 19:ijms19041128. [PMID: 29642568 PMCID: PMC5979305 DOI: 10.3390/ijms19041128] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2018] [Revised: 03/31/2018] [Accepted: 04/05/2018] [Indexed: 11/29/2022] Open
Abstract
Radiation of the chest during cancer therapy is deleterious to the heart, mostly due to oxidative stress and inflammation related injury. A single sub-lethal dose of irradiation has been shown to result in compensatory up-regulation of the myocardial connexin-43 (Cx43), activation of the protein kinase C (PKC) signaling along with the decline of microRNA (miR)-1 and an increase of miR-21 levels in the left ventricle (LV). We investigated whether drugs with antioxidant, anti-inflammatory or vasodilating properties, such as aspirin, atorvastatin, and sildenafil, may affect myocardial response in the LV and right ventricle (RV) following chest irradiation. Adult, male Wistar rats were subjected to a single sub-lethal dose of chest radiation at 25 Gy and treated with aspirin (3 mg/day), atorvastatin (0.25 mg/day), and sildenafil (0.3 mg/day) for six weeks. Cx43, PKCε and PKCδ proteins expression and levels of miR-1 as well as miR-21 were determined in the LV and RV. Results showed that the suppression of miR-1 was associated with an increase of total and phosphorylated forms of Cx43 as well as PKCε expression in the LV while having no effect in the RV post-irradiation as compared to the non-irradiated rats. Treatment with aspirin and atorvastatin prevented an increase in the expression of Cx43 and PKCε without change in the miR-1 levels. Furthermore, treatment with aspirin, atorvastatin, and sildenafil completely prevented an increase of miR-21 in the LV while having partial effect in the RV post irradiation. The increase in pro-apoptotic PKCδ was not affected by any of the used treatment. In conclusion, irradiation and drug-induced changes were less pronounced in the RV as compared to the LV. Treatment with aspirin and atorvastatin interfered with irradiation-induced compensatory changes in myocardial Cx43 protein and miR-21 by preventing their elevation, possibly via amelioration of oxidative stress and inflammation.
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Kohutova J, Elsnicova B, Holzerova K, Neckar J, Sebesta O, Jezkova J, Vecka M, Vebr P, Hornikova D, Szeiffova Bacova B, Egan Benova T, Hlavackova M, Tribulova N, Kolar F, Novakova O, Zurmanova JM. Anti-arrhythmic Cardiac Phenotype Elicited by Chronic Intermittent Hypoxia Is Associated With Alterations in Connexin-43 Expression, Phosphorylation, and Distribution. Front Endocrinol (Lausanne) 2018; 9:789. [PMID: 30740090 PMCID: PMC6357219 DOI: 10.3389/fendo.2018.00789] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/24/2018] [Accepted: 12/14/2018] [Indexed: 12/31/2022] Open
Abstract
Remodeling of the cellular distribution of gap junctions formed mainly by connexin-43 (Cx43) can be related to the increased incidence of cardiac arrhythmias. It has been shown that adaptation to chronic intermittent hypobaric hypoxia (IHH) attenuates the incidence and severity of ischemic and reperfusion ventricular arrhythmias and increases the proportion of anti-arrhythmic n-3 polyunsaturated fatty acids (n-3 PUFA) in heart phospholipids. Wistar rats were exposed to simulated IHH (7,000 m, 8-h/day, 35 exposures) and compared with normoxic controls (N). Cx43 expression, phosphorylation, localization and n-3 PUFA proportion were analyzed in left ventricular myocardium. Compared to N, IHH led to higher expression of total Cx43, its variant phosphorylated at Ser368 [p-Cx43(Ser368)], which maintains "end to end" communication, as well as p-Cx43(Ser364/365), which facilitates conductivity. By contrast, expression of non-phosphorylated Cx43 and p-Cx43(Ser278/289), attenuating intercellular communication, was lower in IHH than in N. IHH also resulted in increased expression of protein kinase A and protein kinase G while casein kinase 1 did not change compared to N. In IHH group, which exhibited reduced incidence of ischemic ventricular arrhythmias, Cx43 and p-Cx43(Ser368) were more abundant at "end to end" gap junctions than in N group and this difference was preserved after acute regional ischemia (10 min). We further confirmed higher n-3 PUFA proportion in heart phospholipids after adaptation to IHH, which was even further increased by ischemia. Our results suggest that adaptation to IHH alters expression, phosphorylation and distribution of Cx43 as well as cardioprotective n-3PUFA proportion suggesting that the anti-arrhythmic phenotype elicited by IHH can be at least partly related to the stabilization of the "end to end" conductivity between cardiomyocytes during brief ischemia.
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Affiliation(s)
- Jana Kohutova
- Department of Physiology, Faculty of Science, Charles University, Prague, Czechia
| | - Barbara Elsnicova
- Department of Physiology, Faculty of Science, Charles University, Prague, Czechia
| | - Kristyna Holzerova
- Developmental Cardiology, Institute of Physiology of the Czech Academy of Sciences, Prague, Czechia
| | - Jan Neckar
- Developmental Cardiology, Institute of Physiology of the Czech Academy of Sciences, Prague, Czechia
| | - Ondrej Sebesta
- Laboratory of Confocal and Fluorescence Microscopy, Faculty of Science, Charles University, Prague, Czechia
| | - Jana Jezkova
- Department of Physiology, Faculty of Science, Charles University, Prague, Czechia
| | - Marek Vecka
- 4th Department of Internal Medicine, 1st Faculty of Medicine, Charles University, Prague, Czechia
| | - Pavel Vebr
- Department of Physiology, Faculty of Science, Charles University, Prague, Czechia
| | - Daniela Hornikova
- Department of Physiology, Faculty of Science, Charles University, Prague, Czechia
| | - Barbara Szeiffova Bacova
- Center of Experimental Medicine of the Slovak Academy of Sciences, Institute for Heart Research, Bratislava, Slovakia
| | - Tamara Egan Benova
- Center of Experimental Medicine of the Slovak Academy of Sciences, Institute for Heart Research, Bratislava, Slovakia
| | - Marketa Hlavackova
- Developmental Cardiology, Institute of Physiology of the Czech Academy of Sciences, Prague, Czechia
| | - Narcis Tribulova
- Center of Experimental Medicine of the Slovak Academy of Sciences, Institute for Heart Research, Bratislava, Slovakia
| | - Frantisek Kolar
- Developmental Cardiology, Institute of Physiology of the Czech Academy of Sciences, Prague, Czechia
| | - Olga Novakova
- Department of Physiology, Faculty of Science, Charles University, Prague, Czechia
- Developmental Cardiology, Institute of Physiology of the Czech Academy of Sciences, Prague, Czechia
| | - Jitka M. Zurmanova
- Department of Physiology, Faculty of Science, Charles University, Prague, Czechia
- *Correspondence: Jitka M. Zurmanova
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Katengua-Thamahane E, Szeiffova Bacova B, Bernatova I, Sykora M, Knezl V, Van Rooyen J, Tribulova N. Effects of Red Palm Oil on Myocardial Antioxidant Enzymes, Nitric Oxide Synthase and Heart Function in Spontaneously Hypertensive Rats. Int J Mol Sci 2017; 18:ijms18112476. [PMID: 29160855 PMCID: PMC5713442 DOI: 10.3390/ijms18112476] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2017] [Revised: 11/10/2017] [Accepted: 11/14/2017] [Indexed: 02/07/2023] Open
Abstract
The purpose of this study was to investigate the effect of antioxidants rich red palm oil (RPO) supplementation on cardiac oxidative stress known as crucial factor deteriorating heart function in hypertension. 3-month-old, male spontaneously hypertensive rats (SHR) and normotensive Wistar Kyoto rats (WKY) were fed standard rat chow without or with RPO (0.2 mL/day/5 weeks). General characteristic of rats were registered. Left ventricular tissue (LV) was used to determine expression of superoxide dismutases (SOD1, SOD2) and glutathione peroxidases (Gpx) as well as activity of nitric oxide synthase (NOS). Functional parameters of the heart were examined during basal conditions and at the early-phase of post-ischemic reperfusion using Langendorff-perfused system. RPO intake significantly reduced elevated blood pressure and total NOS activity as well as increased lowered expression of mitochondrial SOD2 in SHR hearts during basal condition. Moreover, RPO supplementation resulted in suppression of elevated heart rate, increase of reduced coronary flow and enhancement of systolic and diastolic heart function at the early-phase of post-ischemic reperfusion. It is concluded that SHR benefit from RPO intake due to decrease of blood pressure, amelioration of oxidative stress and protection of heart function that was deteriorated by post-ischemic reperfusion.
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Affiliation(s)
- Emma Katengua-Thamahane
- Botho University, Francistown Campus, Plot 6434 Tati River plots, Francistown P/Bag F451, Botswana.
| | - Barbara Szeiffova Bacova
- Institute for Heart Research, Slovak Academy of Sciences, Dúbravská cesta 9, P.O. Box 104, 840 05 Bratislava, Slovakia.
| | - Iveta Bernatova
- Institute of Normal and Pathological Physiology, Slovak Academy of Sciences, Sienkiewiczova 1, 813 71 Bratislava, Slovakia.
| | - Matus Sykora
- Institute for Heart Research, Slovak Academy of Sciences, Dúbravská cesta 9, P.O. Box 104, 840 05 Bratislava, Slovakia.
| | - Vladimir Knezl
- Institute of Experimental Pharmacology and Toxicology, Slovak Academy of Sciences, Dúbravská Cesta 9, 841 04 Bratislava, Slovakia.
| | - Jacques Van Rooyen
- Binutra, Unit E 11 Prime Business Park Mocke Rd., Diep River, Cape Town 7806, South Africa.
| | - Narcis Tribulova
- Institute for Heart Research, Slovak Academy of Sciences, Dúbravská cesta 9, P.O. Box 104, 840 05 Bratislava, Slovakia.
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Omega-3 Index and Anti-Arrhythmic Potential of Omega-3 PUFAs. Nutrients 2017; 9:nu9111191. [PMID: 29084142 PMCID: PMC5707663 DOI: 10.3390/nu9111191] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2017] [Revised: 10/18/2017] [Accepted: 10/23/2017] [Indexed: 01/22/2023] Open
Abstract
Omega-3 polyunsaturated fatty acids (PUFAs), namely eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are permanent subjects of interest in relation to the protection of cardiovascular health and the prevention of the incidence of both ventricular and atrial arrhythmias. The purpose of this updated review is to focus on the novel cellular and molecular effects of omega-3 PUFAs, in the context of the mechanisms and factors involved in the development of cardiac arrhythmias; to provide results of the most recent studies on the omega-3 PUFA anti-arrhythmic efficacy and to discuss the lack of the benefit in relation to omega-3 PUFA status. The evidence is in the favor of omega-3 PUFA acute and long-term treatment, perhaps with mitochondria-targeted antioxidants. However, for a more objective evaluation of the anti-arrhythmic potential of omega-3 PUFAs in clinical trials, it is necessary to monitor the basal pre-interventional omega-3 status of individuals, i.e., red blood cell content, omega-3 index and free plasma levels. In the view of evidence-based medicine, it seems to be crucial to aim to establish new approaches in the prevention of cardiac arrhythmias and associated morbidity and mortality that comes with these conditions.
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Viczenczova C, Kura B, Chaudagar KK, Szeiffova Bacova B, Egan Benova T, Barancik M, Knezl V, Ravingerova T, Tribulova N, Slezak J. Myocardial connexin-43 is upregulated in response to acute cardiac injury in rats. Can J Physiol Pharmacol 2017; 95:911-919. [PMID: 28459162 DOI: 10.1139/cjpp-2016-0680] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We aimed to explore whether myocardial intercellular channel protein connexin-43 (Cx43) along with PKCε and MMP-2 might be implicated in responses to acute cardiac injury induced by 2 distinct sublethal interventions in Wistar rats. Animals underwent either single chest irradiation at dose of 25 Gy or subcutaneous injection of isoproterenol (ISO, 120 mg/kg) and were compared with untreated controls. Forty-two days post-interventions, the hearts were excised and left ventricles were used for analysis. The findings showed an increase of total as well as phosphorylated forms of myocardial Cx43 regardless of the type of interventions. Enhanced phosphorylation of Cx43 coincided with increased PKCε expression in both models. Elevation of Cx43 was associated with its enhanced distribution on lateral surfaces of the cardiomyocytes in response to both interventions, while focal areas of fibrosis without Cx43 were found in post-ISO but not post-irradiated rat hearts. In parallel, MMP-2 activity was decreased in the former while increased in the latter. Cardiac function was maintained and the susceptibility of the hearts to ischemia or malignant arrhythmias was not deteriorated 42 days after interventions when compared with controls. Altogether, the findings indicate that myocardial Cx43 is most likely implicated in potentially salutary responses to acute heart injury.
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Affiliation(s)
- Csilla Viczenczova
- a Institute for Heart Research, Slovak Academy of Sciences, Bratislava, Slovak Republic
| | - Branislav Kura
- a Institute for Heart Research, Slovak Academy of Sciences, Bratislava, Slovak Republic
| | | | | | - Tamara Egan Benova
- a Institute for Heart Research, Slovak Academy of Sciences, Bratislava, Slovak Republic
| | - Miroslav Barancik
- a Institute for Heart Research, Slovak Academy of Sciences, Bratislava, Slovak Republic
| | - Vladimir Knezl
- c Institute of Experimental Pharmacology and Toxicology, Slovak Academy of Sciences, Bratislava, Slovak Republic
| | - Tana Ravingerova
- a Institute for Heart Research, Slovak Academy of Sciences, Bratislava, Slovak Republic
| | - Narcis Tribulova
- a Institute for Heart Research, Slovak Academy of Sciences, Bratislava, Slovak Republic
| | - Jan Slezak
- a Institute for Heart Research, Slovak Academy of Sciences, Bratislava, Slovak Republic
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Egan Benova T, Szeiffova Bacova B, Viczenczova C, Diez E, Barancik M, Tribulova N. Protection of cardiac cell-to-cell coupling attenuate myocardial remodeling and proarrhythmia induced by hypertension. Physiol Res 2017; 65 Suppl 1:S29-42. [PMID: 27643938 DOI: 10.33549/physiolres.933391] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Gap junction connexin channels are important determinants of myocardial conduction and synchronization that is crucial for coordinated heart function. One of the main risk factors for cardiovascular events that results in heart attack, congestive heart failure, stroke as well as sudden arrhythmic death is hypertension. Mislocalization and/or dysfunction of specific connexin-43 channels due to hypertension-induced myocardial remodeling have been implicated in the occurrence of life-threatening arrhythmias and heart failure in both, humans as well as experimental animals. Recent studies suggest that down-regulation of myocardial connexin-43, its abnormal distribution and/or phosphorylation might be implicated in this process. On the other hand, treatment of hypertensive animals with cardioprotective drugs (e.g. statins) or supplementation with non-pharmacological compounds, such as melatonin, omega-3 fatty acids and red palm oil protects from lethal arrhythmias. The antiarrhythmic effects are attributed to the attenuation of myocardial connexin-43 abnormalities associated with preservation of myocardial architecture and improvement of cardiac conduction. Findings uncover novel mechanisms of cardioprotective (antihypertensive and antiarrhythmic) effects of compounds that are used in clinical settings. Well-designed trials are needed to explore the antiarrhythmic potential of these compounds in patients suffering from hypertension.
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Affiliation(s)
- T Egan Benova
- Institute for Heart Research, Slovak Academy of Sciences, Bratislava, Slovakia.
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29
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Nagibin V, Egan Benova T, Viczenczova C, Szeiffova Bacova B, Dovinova I, Barancik M, Tribulova N. Ageing related down-regulation of myocardial connexin-43 and up-regulation of MMP-2 may predict propensity to atrial fibrillation in experimental animals. Physiol Res 2017; 65 Suppl 1:S91-S100. [PMID: 27643943 DOI: 10.33549/physiolres.933389] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Mechanisms underlying atrial fibrillation (AF), the most common cardiac arrhythmia, particularly in aged population, are not fully elucidated. We have previously shown an increased propensity of old guinea pigs (GPs) heart to inducible AF when comparing to young animals. This study aimed to verify our hypothesis that susceptibility of aged heart to AF may be attributed to abnormalities in myocardial connexin-43 (Cx43) and extracellular matrix that affect cardiac electrical properties. Experiments were conducted on male and female 4-week-old and 24-week-old GPs. Atrial tissue was processed for analysis of Cx43 topology using immunohistochemistry, expression of Cx43 protein using immunobloting, and expression of mRNA of Cx43 and extracellular matrix metalloproteinase-2 (MMP-2) using real time PCR. Immunohistochemistry revealed uniform Cx43 distribution predominantly on lateral sides of the cardiomyocytes of young male and female GP atria. In contrast, non-uniform distribution, mislocalization and reduced immunolabeling of Cx43 were detected in atria of old GPs. In parallel, the atrial tissue levels of Cx43 mRNA were significantly decreased, while mRNA expression of MMP-2 was significantly increased in old versus young GPs. The changes were more pronounced in old GPs males comparing to females. Findings indicate that age-related down-regulation of atrial Cx43 and up-regulation of MMP-2 as well as disordered Cx43 distribution can facilitate development of AF in old guinea pig hearts.
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Affiliation(s)
- V Nagibin
- Institute for Heart Research, Slovak Academy of Sciences, Bratislava, Slovakia.
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Szeiffová Bačová B, Egan Beňová T, Viczenczová C, Soukup T, Rauchová H, Pavelka S, Knezl V, Barančík M, Tribulová N. Cardiac connexin-43 and PKC signaling in rats with altered thyroid status without and with omega-3 fatty acids intake. Physiol Res 2017; 65 Suppl 1:S77-90. [PMID: 27643942 DOI: 10.33549/physiolres.933413] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Thyroid hormones are powerful modulators of heart function and susceptibility to arrhythmias via both genomic and non-genomic actions. We aimed to explore expression of electrical coupling protein connexin-43 (Cx43) in the heart of rats with altered thyroid status and impact of omega-3 polyunsaturated fatty acids (omega-3) supplementation. Adult male Lewis rats were divided into following six groups: euthyroid controls, hyperthyroid (treated with T(3)) and hypothyroid (treated with methimazol) with or without six-weeks lasting supplementation with omega-3 (20 mg/100 g/day). Left and right ventricles, septum and atria were used for immunoblotting of Cx43 and protein kinase C (PKC). Total expression of Cx43 and its phosphorylated forms were significantly increased in all heart regions of hypothyroid rats compared to euthyroid controls. In contrast, the total levels of Cx43 and its functional phosphorylated forms were decreased in atria and left ventricle of hyperthyroid rats. In parallel, the expression of PKC epsilon that phosphorylates Cx43, at serine 368, was increased in hypothyroid but decreased in hyperthyroid rat hearts. Omega-3 intake did not significantly affect either Cx43 or PKC epsilon alterations. In conclusion, there is an inverse relationship between expression of cardiac Cx43 and the levels of circulating thyroid hormones. It appears that increased propensity of hyperthyroid while decreased of hypothyroid individuals to malignant arrhythmias may be in part attributed to the changes in myocardial Cx43.
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Affiliation(s)
- B Szeiffová Bačová
- Institute for Heart Research, Slovak Academy of Sciences, Bratislava, Slovak Republic.
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Petersen F, Rodrigo R, Richter M, Kostin S. The effects of polyunsaturated fatty acids and antioxidant vitamins on atrial oxidative stress, nitrotyrosine residues, and connexins following extracorporeal circulation in patients undergoing cardiac surgery. Mol Cell Biochem 2017; 433:27-40. [DOI: 10.1007/s11010-017-3013-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2017] [Accepted: 03/15/2017] [Indexed: 12/27/2022]
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32
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Bačová BS, Vinczenzová C, Žurmanová J, Kašparová D, Knezl V, Beňová TE, Pavelka S, Soukup T, Tribulová N. Altered thyroid status affects myocardial expression of connexin-43 and susceptibility of rat heart to malignant arrhythmias that can be partially normalized by red palm oil intake. Histochem Cell Biol 2016; 147:63-73. [DOI: 10.1007/s00418-016-1488-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/26/2016] [Indexed: 01/25/2023]
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Radosinska J, Kurahara LH, Hiraishi K, Viczenczova C, Egan Benova T, Szeiffova Bacova B, Dosenko V, Navarova J, Obsitnik B, Imanaga I, Soukup T, Tribulova N. Modulation of cardiac connexin-43 by omega-3 fatty acid ethyl-ester supplementation demonstrated in spontaneously diabetic rats. Physiol Res 2015; 64:795-806. [PMID: 26447526 DOI: 10.33549/physiolres.933075] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Previous data suggest that type 1 diabetes mellitus leads to the deterioration of myocardial intercellular communication mediated by connexin-43 (Cx43) channels. We therefore aimed to explore Cx43, PKC signaling and ultrastructure in non-treated and omega-3 fatty acid (omega-3) treated spontaneously diabetic Goto-Kakizaki (GK) rats considered as type 2 diabetes model. Four-week-old GK and non-diabetic Wistar-Clea rats were fed omega-3 (200 mg/kg/day) for 2 months and compared with untreated rats. Real-time PCR and immunoblotting were performed to determine Cx43, PKC-epsilon and PKC-delta expression. In situ Cx43 was examined by immunohistochemistry and subcellular alterations by electron microscopy. Omega-3 intake reduced blood glucose, triglycerides, and cholesterol in diabetic rats and this was associated with improved integrity of cardiomyocytes and capillaries in the heart. Myocardial Cx43 mRNA and protein levels were higher in diabetic versus non-diabetic rats and were further enhanced by omega-3. The ratio of phosphorylated (functional) to non-phosphorylated Cx43 was lower in diabetic compared to non-diabetic rats but was increased by omega-3, in part due to up-regulation of PKC-epsilon. In addition, pro-apoptotic PKC-delta expression was decreased. In conclusion, spontaneously diabetic rats at an early stage of disease benefit from omega-3 intake due to its hypoglycemic effect, upregulation of myocardial Cx43, and preservation of cardiovascular ultrastructure. These findings indicates that supplementation of omega-3 may be beneficial also in the management of diabetes in humans.
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Affiliation(s)
- J Radosinska
- Institute of Physiology, Faculty of Medicine, Comenius University, Bratislava, Slovakia, Institute for Heart Research, Slovak Academy of Sciences, Bratislava, Slovakia.
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