Narcis Tribulova's research while affiliated with Slovak Academy of Sciences and other places
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Publications (247)
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...
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 an impact of volume overload due to aorto-caval fistula (ACF) on Cx43 and ECM as well as...
Objective
Heart failure is a clinical syndrome characterized by cardiac dysfunction due to structural abnormalities of the myocardium that results in the inability of the heart to eject sufficient volume of the blood to the circulation. HF is a major cause of morbidity and mortality in the world. The ECM is a highly dynamic structure controlling th...
Objective
Experimental and clinical studies suggest that myocardial hypertrophy in response to hypertension and hyperthyroidism increases propensity to cardiac arrhythmias. While these are rare in conditions resulting in myocardial atrophy, such as hypothyroidism or type-1 diabetes mellitus (T1DM). One of the crucial factors impacting the susceptib...
Objective
Available data suggest that meta-inflammation and oxidative stress as well as endogenous deficiency of omega-3 and melatonin may be involved in hypertension-induced myocardial abnormalities that increase propensity to cardiac arrhythmias. We aimed to explore whether supplementation with omega-3 and melatonin as well as cold acclimation ma...
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 hear...
Cardiac rhythm disorders, in particular life-threatening ventricular fibrillation and stroke-provoking fibrillation of the atria, are a permanent focus of both clinical and experimental cardiologists [...]
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...
Light pollution disrupts circadian rhythms that may promote obesity and hypertension, but their association with the susceptibility to malignant cardiac arrhythmias is not well known. We examined whether continuous light as well as a high sucrose diet affect rat heart gene transcripts, miRNAs, or protein expression and hence arrhythmogenesis. In pa...
Pathogenesis of heart failure (HF) and hypertension with a focus on extracellular matrix (ECM) and communication in the heart is still a current scientific topic that calls for new findings. We used as experimental model normotensive (HSD) and hypertensive (TGR) rats with aortocaval fistula (ACF) supplemented with an ACE inhibitor (ACEi)(15weeks, 6...
This review focuses on cardiac atrophy resulting from mechanical or metabolic unloading due to various conditions, describing some mechanisms and discussing possible strategies or interventions to prevent, attenuate or reverse myocardial atrophy. An improved awareness of these conditions and an increased focus on the identification of mechanisms an...
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 SHR...
Funding Acknowledgements
Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Scientific Grant Agency of the Ministry of Education, Science, Research and Sport of the Slovak Republic VEGA 2/0158/19, VEGA 2/0002/20; Slovak Research and Development Agency APVV-15-0119, APVV-18-0548
The extracellular matrix (ECM) is...
Funding Acknowledgements
Type of funding sources: None.
Light pollution disrupts circadian rhythms and increases the development of obesity, but their connection to cardiovascular disease, in particular to malignant arrhythmias, is not well known.
Herein, we investigated if female rats exposed to continuous light and high-sucrose diet had altered m...
Funding Acknowledgements
Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Scientific Grant Agency of the Ministry of Education, Science, Research and Sport of the Slovak Republic VEGA 2/0158/19, 2/0002/20 and Slovak Research and Development Agency APVV 18-0548,19-0317
Background
We have previously shown that...
Objective:
We have previously shown that down-regulation of myocardial gap junction channel protein, connexin-43 (Cx43), and up-regulation of extracellular matrix (ECM) proteins in hearts of spontaneously hypertensive rats (SHR) promote occurrence of lethal arrhythmia. Cold acclimation has a potential for reducing cardiovascular risk, especially i...
Objective:
New findings in the pathogenesis of heart failure (HF) with a focus on extracellular matrix (ECM) and communication in the heart are still relevant for more effective treatment. We focused on signaling pathways involved in cardiac structural remodeling in HF due to pressure and volume overload, as well as on investigating the efficacy o...
Objective:
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 Omacorâ supplementation ben...
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 susce...
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 affe...
Rationale and purpose
Prevention or attenuation of heart failure (HF) is persistent task in clinic as well as challenge for progress in research. Both, intercellular connexin-43 (Cx43) channels and extracellular matrix (ECM) exert high impact on heart function. Thus, we aimed to explore whether HF due to volume overload (VO) induces alterations in...
The extracellular matrix (ECM) is a highly dynamic structure that affects the proper functioning of various tissues. ECM is involved in cell signaling, participates in the origin and development of pathology and its positive influence can result in improved disease. The pathophysiology of ECM also affects intercellular communication, which results...
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 contracti...
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, jeopard...
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 protei...
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 the...
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...
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 extracel...
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 p...
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 mi...
Red palm oil (RPO) is a rich natural source of antioxidant vitamins, namely carotenes, tocopherols and tocotrienols. However, it contains approximately 50 % saturated fatty acids the regular consumption of which could negatively modify lipid profile. The aim of our study was to test whether 7 weeks of RPO supplementation (1 g/kg body weight/day) wo...
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...
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...
Irradiation of normal tissues leads to acute increase in reactive oxygen/nitrogen species that serve as intra and intercellular signaling to alter cell and tissue function. In the case of chest irradiation it can affect the heart, blood vessels and lungs, with consequent tissue remodelation and adverse side effects and symptoms. This complex proces...
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 two distinct sub-lethal interventions in Wistar rats. Animals underwent either single chest irradiation at dose of 25 Gy or subcutaneous injection of isoproterenol (ISO...
We aimed to explore the effects of melatonin and n-3 polyunsaturated fatty acids (PUFA) supplementation on plasma and aortic nitric oxide (NO) levels in isoproterenol (Iso) affected spontaneously hypertensive (SHR) and Wistar rats. Untreated control rats were compared with Iso injected (118 mg/kg, s.c.) rats, and Iso injected plus supplemented with...
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...
Excessive production of oxygen free radicals has been regarded as a causative common denominator of many pathological processes in the animal kingdom. Hydroxyl and nitrosyl radicals represent the major cause of the destruction of biomolecules either by a direct reaction or by triggering a chain reaction of free radicals. Scavenging of free radicals...
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 dysfun...
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 ma...
We aimed to determine the impact of Ca(2+)-related disorders induced in intact animal hearts on ultrastructure of the cardiomyocytes prior to occurrence of severe arrhythmias. Three types of acute experiments were performed that are known to be accompanied by disturbances in Ca(2+) handling. Langedorff-perfused rat or guinea pig hearts subjected to...
Gap-junction connexin (Cx) channels are important determinants of myocardial conduction and synchronization that is crucial for heart function. Hypertension-induced structural remodeling is associated with an increased risk of life-threatening arrhythmias and heart failure in both humans and experimental animals. Recent studies suggest that abnorma...
Intercellular connexin-43 (Cx43) channels are essential for electrical coupling and direct cardiac cell to cell communication to ensure heart function. Expression of Cx43 is altered due to stressful conditions and also affected by the alterations in extracellular matrix. We aimed to explore the effect of chest irradiation on myocardial expression o...
The natural polyphenolic compound quercetin is a flavonoid that exerts various biological effects including anti-oxidative and radical-scavenging activities. Moreover, quercetin has been shown to possess some preventive actions in treatment of cardiovascular diseases. The aim of the present study was to explore the effects of prolonged administrati...
Objectives: Cardioprotective compounds, atorvastatin, melatonin, eicosapentaenoic (EPA) and docosahexaenoic acid (DPA) show antiarrhythmic effects in clinical as well as in experimental studies, but their acute effects are less examined. The aim of the study was to further our understanding of the effects of monitored antiarrhythmic agents and thei...
This review deals with the understanding of the role of key factors of ageing, oxidative stress and inflammation, in relation to development of age-related cardiovascular disease, atrial fibrillation. Increased production of reactive oxygen species and systemic inflammation promote cardiac structural and electrophysiologic remodeling that is crucia...
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 ty...
Rationale: Hypokalemia is the most common electrolyte abnormality encountered in clinical practice and enhances the propensity for ventricular fibrillation (VF). Melatonin upregulates the gap junction channels protein, connexin43 (Cx43), rendering the heart more resistant to electricallyinduced VF. We hypothesized that melatonin may protect agai...
Objective: Sustained beta-adrenoceptor activation is deleterious to the heart due to induction of pathological remodeling and compromising cardiomyocytes viability that increase a risk for sudden cardiac death. Our and others studies suggest that melatonin and omega-3 fatty acids are cardioprotective but underlying mechanisms are not fully elucidat...
Melatonin prevents alterations in the gap junction channels formed by connexin-43 (Cx43) rendering the heart more resistant to electricallyinduced ventricular fibrillation (VF) but its properties in others arrhythmogenic scenarios like hypokalemia remain unknouwn. We hypothesized that melatonin may protect against low potassium induced VF in part b...
In addition to cytostatic treatment and surgery, the most common cancer treatment is gamma radiation. Despite sophisticated radiological techniques however, in addition to irradiation of the tumor, irradiation of the surrounding healthy tissue also takes place, which results in various side-effects, depending on the absorbed dose of radiation. Radi...
Defects in intercellular coupling in the heart play a key role in the initiation and persistence of malignant arrhythmias. Such disorders result from abnormal expression and distribution of connexins, the major constituents of cardiac gap junction channels. The alterations of myocardial connexin are well established as a consistent feature of both...
Cardioprotective compounds such as atorvastatin, melatonin, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) exhibit antiarrhythmic potential in clinical and/or experimental conditions but underlying mechanisms are poorly understood. We have previously shown that protection from ventricular fibrillation (VF) due to prolonged treatment wit...
Objectives: It is very well known from experimental as well as clinical studies that the pineal hormone, melatonin, which regulates circadian rhythms, exhibits cardioprotective effects.The goal of the study was to confirm our hypothesis and to explore the antiarrhythmic effects of the supplementation of melatonin in hypertensive and normotensive ra...
One of the most widely used methods of treating oncological patients is ionizing radiation therapy. Radiation beam causes damage to the cancer cells which can reduce cancerous mass and leads to recovery of the oncological patients. On the other hand irradiation of other nearby tissues like myocardium can cause some damage which can induce serious h...
Background and Purpose: Melatonin in addition to regulation of circadian rhythm exhibits antihypertensive, free radicals scavenging and antiarrhythmic effects as we have shown recently. While melatonin deficiency and lower omega-3 index observed in pts suffering from CHD and hypertension as well as in SHR can contribute to disease progression and p...
Objectives: Myocardial synchronization and proper heart function depends on the expression and subcellular distribution of intercellular connexin-43 (Cx43) channels that are essential for electrical coupling and direct cell-to-cell communication. Radiotherapy is applied to treat cancer but chest irradiation can induce heart disease. We hypothesized...
Background: Hypertension remains the most prevalent risk factor that increases propensity of the heart to the malignant arrhythmias due to myocardial remodeling. Data, including ours, suggest that hypertension is accompanied by melatonin and omega-3 FA deficiency but enhanced free radicals production. In turn, high BP was reduced in pts and/or anim...
Background and purpose: The cardiovascular system is modulated by thyroid hormones and their deficiency or excess in hypo- (HY) or hyperthyroid (TH) status may affect both cardiac function and arrhythmogenesis. We hypothesized that intercellular communication via connexin-43 (Cx43) channels might be implicated. The goal of this study was to explore...
Objective: Hypertension-induced myocardial remodelling is known to be associated with increased risk of malignant arrhythmias and alterations in electrical coupling protein, connexin-43 (Cx43), may be involved in the pathogenesis. We investigated whether omega-3 fatty acids intake affects abnormalities of Cx43 as well as protein kinase C (PKC) sign...
