Development of new pharmacological approaches in the treatment of hypertension and cardioprotection against the progression of congestive heart failure (CHF) are in the forefront of current cardiovascular research. Indeed, it has been shown that cardiac dysfunction exacerbate progression of kidney failure that commonly known as cardiorenal syndrome (CRS). Considering novel cardiovascular therapy, promising cardio- and renoprotective therapeutic approach might be the use of epoxyeicosatrienoic acids (EETs). The effectiveness of EET-based therapy depends on increase EETs bioavailability and limit EETs degradation by soluble epoxide hydrolase (sEH). As such, this project will analyse the effect increased tissue availability of endogenous EETs by sEH inhibitor or mimic actions of endogenous EETs by EET analog on hypertension, progression of CHF after myocardial infarction and the associated CRS. Further, we also propose to delineate the mechanism of EETs actions on organ protection in CHF and CRS in relation to their intricate relationship with hypoxia inducible factor-1? signalling.

Vývoj nových farmakologických přístupů v léčbě hypertenze a chronického srdečního selhání jsou v popředí zájmu současného kardiovaskulárního výzkumu. Rozvoj chronického srdečního selhání velmi často vede k poškození funkce ledvin a tento stav je označován jako tzv. chronická forma kardiorenálního syndromu. Jak naznačují současné studie, slibným terapeutickým přístupem při léčbě omenocnění srdce a ledvin mohou být epoxyeikosatrienové kyseliny (EETs). Účinnost protektivní terapie založené na EETs závisí buď na zvýšení biologické dostupnosti EETs nebo snížení jejich degradace enzymem solubilní epoxid hydrolázou (sEH). Hlavním cílem tohoto projektu bude zjistit, jak ovlivní terapie založená na podávání inhibitoru sEH resp. agonistického EET analogu rozvoj hypertenze a chronického srdečního selhání po infarku myokardu a související vznik kardiorenálního syndromu. Dále se budeme zabývat otázkou, jakou úlohu v kardio- a renoprotektivním léčbě založené na EETs hraje buněčná signalizace spojená s aktivací hypoxií indukovaného faktoru-1?.

• MeSH
• epoxid hydrolasy terapeutické užití   MeSH
• hypertenze komplikace   MeSH
• infarkt myokardu komplikace   MeSH
• kardiorenální syndrom etiologie   farmakoterapie   MeSH
• komorbidita MeSH
• krysa rodu rattus MeSH
• kyseliny arachidonové terapeutické užití   MeSH
• lidé MeSH
• modely nemocí na zvířatech MeSH
• srdeční selhání etiologie   farmakoterapie   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu rattus MeSH
• lidé MeSH
• zvířata MeSH

• Konspekt
• Patologie. Klinická medicína
• NLK Obory
• kardiologie
• nefrologie
• NLK Publikační typ
• závěrečné zprávy o řešení grantu AZV MZ ČR

Necroptosis has been recognized in heart failure (HF). In this study, we investigated detailed necroptotic signalling in infarcted and non-infarcted areas separately and its mechanistic link with main features of HF. Post-infarction HF in rats was induced by left coronary occlusion (60 minutes) followed by 42-day reperfusion. Heart function was assessed echocardiographically. Molecular signalling and proposed mechanisms (oxidative stress, collagen deposition and inflammation) were investigated in whole hearts and in subcellular fractions when appropriate. In post-infarction failing hearts, TNF and pSer229-RIP3 levels were comparably increased in both infarcted and non-infarcted areas. Its cytotoxic downstream molecule p-MLKL, indicating necroptosis execution, was detected in infarcted area. In non-infarcted area, despite increased pSer229-RIP3, p-MLKL was present in neither whole cells nor the cell membrane known to be associated with necroptosis execution. Likewise, increased membrane lipoperoxidation and NOX2 levels unlikely promoted pro-necroptotic environment in non-infarcted area. Collagen deposition and the inflammatory csp-1-IL-1β axis were active in both areas of failing hearts, while being more pronounced in infarcted tissue. Although apoptotic proteins were differently expressed in infarcted and non-infarcted tissue, apoptosis was found to play an insignificant role. p-MLKL-driven necroptosis and inflammation while inflammation only (without necroptotic cell death) seem to underlie fibrotic healing and progressive injury in infarcted and non-infarcted areas of failing hearts, respectively. Upregulation of pSer229-RIP3 in both HF areas suggests that this kinase, associated with both necroptosis and inflammation, is likely to play a dual role in HF progression.

• MeSH
• apoptóza fyziologie   MeSH
• buněčná smrt fyziologie   MeSH
• infarkt myokardu metabolismus   MeSH
• kardiomyocyty metabolismus   MeSH
• krysa rodu rattus MeSH
• nekroptóza fyziologie   MeSH
• nekróza metabolismus   MeSH
• oxidační stres fyziologie   MeSH
• potkani Sprague-Dawley MeSH
• serin-threoninkinasy interagující s receptory metabolismus   MeSH
• signální transdukce fyziologie   MeSH
• srdeční selhání metabolismus   MeSH
• upregulace fyziologie   MeSH
• zánět metabolismus   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Epoxyeicosatrienoic acids (EETs) and their synthetic analogs have cardiovascular protective effects. Here, we investigated the action of a novel EET analog EET-B on the progression of post-myocardial infarction (MI) heart failure in spontaneously hypertensive rats (SHR). Adult male SHR were divided into vehicle- and EET-B (10 mg/kg/day; p.o., 9 weeks)-treated groups. After 2 weeks of treatment, rats were subjected to 30-min left coronary artery occlusion or sham operation. Systolic blood pressure (SBP) and echocardiography (ECHO) measurements were performed at the beginning of study, 4 days before, and 7 weeks after MI. At the end of the study, tissue samples were collected for histological and biochemical analyses. We demonstrated that EET-B treatment did not affect blood pressure and cardiac parameters in SHR prior to MI. Fractional shortening (FS) was decreased to 18.4 ± 1.0% in vehicle-treated MI rats compared with corresponding sham (30.6 ± 1.0%) 7 weeks following MI induction. In infarcted SHR hearts, EET-B treatment improved FS (23.7 ± 0.7%), markedly increased heme oxygenase-1 (HO-1) immunopositivity in cardiomyocytes and reduced cardiac inflammation and fibrosis (by 13 and 19%, respectively). In conclusion, these findings suggest that EET analog EET-B has beneficial therapeutic actions to reduce cardiac remodeling in SHR subjected to MI.

• MeSH
• hemoxygenasa-1 genetika   metabolismus   MeSH
• infarkt myokardu farmakoterapie   genetika   metabolismus   patofyziologie   MeSH
• krevní tlak MeSH
• krysa rodu rattus MeSH
• kyseliny arachidonové aplikace a dávkování   chemie   MeSH
• lidé MeSH
• modely nemocí na zvířatech MeSH
• potkani inbrední SHR MeSH
• srdce patofyziologie   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu rattus MeSH
• lidé MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH

Epoxyeicosatrienoic acids (EETs) and their analogs have been identified as potent antihypertensive compounds with cardio- and renoprotective actions. Here, we examined the effect of EET-A, an orally active EET analog, and c-AUCB, an inhibitor of the EETs degrading enzyme soluble epoxide hydrolase, on the progression of post-myocardial infarction (MI) heart failure (HF) in normotensive Hannover Sprague-Dawley (HanSD) and in heterozygous Ren-2 transgenic rats (TGR) with angiotensin II-dependent hypertension. Adult male rats (12 weeks old) were subjected to 60-min left anterior descending (LAD) coronary artery occlusion or sham (non-MI) operation. Animals were treated with EET-A and c-AUCB (10 and 1 mg/kg/day, respectively) in drinking water, given alone or combined for 5 weeks starting 24 h after MI induction. Left ventricle (LV) function and geometry were assessed by echocardiography before MI and during the progression of HF. At the end of the study, LV function was determined by catheterization and tissue samples were collected. Ischemic mortality due to the incidence of sustained ventricular fibrillation was significantly higher in TGR than in HanSD rats (35.4 and 17.7%, respectively). MI-induced HF markedly increased LV end-diastolic pressure (Ped) and reduced fractional shortening (FS) and the peak rate of pressure development [+(dP/dt)max] in untreated HanSD compared to sham (non-MI) group [Ped: 30.5 ± 3.3 vs. 9.7 ± 1.3 mmHg; FS: 11.1 ± 1.0 vs. 40.8 ± 0.5%; +(dP/dt)max: 3890 ± 291 vs. 5947 ± 309 mmHg/s]. EET-A and c-AUCB, given alone, tended to improve LV function parameters in HanSD rats. Their combination amplified the cardioprotective effect of single therapy and reached significant differences compared to untreated HanSD controls [Ped: 19.4 ± 2.2 mmHg; FS: 14.9 ± 1.0%; +(dP/dt)max: 5278 ± 255 mmHg/s]. In TGR, MI resulted in the impairment of LV function like HanSD rats. All treatments reduced the increased level of albuminuria in TGR compared to untreated MI group, but neither single nor combined EET-based therapy improved LV function. Our results indicate that EET-based therapy attenuates the progression of post-MI HF in HanSD, but not in TGR, even though they exhibited renoprotective action in TGR hypertensive rats.

• Publikační typ
• časopisecké články MeSH

Long-lasting ischemia can result in cell loss; however, repeated episodes of brief ischemia increase the resistance of the heart against deleterious effects of subsequent prolonged ischemic insult and promote cell survival. Traditionally, it is believed that the supply of blood to the ischemic heart is associated with release of cytokines, activation of inflammatory response, and induction of necrotic cell death. In the past few years, this paradigm of passive necrosis as an uncontrolled cell death has been re-examined and the existence of a strictly regulated form of necrotic cell death, necroptosis, has been documented. This controlled cell death modality, resembling all morphological features of necrosis, has been investigated in different types of ischemia-associated heart injuries. The process of necroptosis has been found to be dependent on the activation of RIP1-RIP3-MLKL axis, which induces changes leading to the rupture of cell membrane. This pathway is activated by TNF-α, which has also been implicated in the cardioprotective signaling pathway of ischemic preconditioning. Thus, this review is intended to describe the TNF-α-mediated signaling leading to either cell survival or necroptotic cell death. In addition, some experimental data suggesting a link between heart dysfunction and the cellular loss due to necroptosis are discussed in various conditions of myocardial ischemia.

• MeSH
• apoptóza * účinky léků   MeSH
• ischemická choroba srdeční metabolismus   patologie   MeSH
• komplex proteinů jaderného póru metabolismus   MeSH
• lidé MeSH
• myokard metabolismus   patologie   MeSH
• nekróza MeSH
• proteinkinasy metabolismus   MeSH
• proteiny vázající RNA metabolismus   MeSH
• serin-threoninkinasy interagující s receptory metabolismus   MeSH
• signální transdukce MeSH
• TNF-alfa metabolismus   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH

Volume overload leads to development of eccentric cardiac hypertrophy and heart failure. In our previous report, we have shown myocyte hypertrophy with no fibrosis and decrease in gap junctional coupling via connexin43 in a rat model of aorto-caval fistula at 21 weeks. Here we set to analyze the electrophysiological and protein expression changes in the left ventricle and correlate them with phenotypic severity based upon ventricles to body weight ratio. ECG analysis showed increased amplitude and duration of the P wave, prolongation of PR and QRS interval, ST segment elevation and decreased T wave amplitude in the fistula group. Optical mapping showed a prolongation of action potential duration in the hypertrophied hearts. Minimal conduction velocity (CV) showed a bell-shaped curve, with a significant increase in the mild cases and there was a negative correlation of both minimal and maximal CV with heart to body weight ratio. Since the CV is influenced by gap junctional coupling as well as the autonomic nervous system, we measured the amounts of tyrosine hydroxylase (TH) and choline acetyl transferase (ChAT) as a proxy for sympathetic and parasympathetic innervation, respectively. At the protein level, we confirmed a significant decrease in total and phosphorylated connexin43 that was proportional to the level of hypertrophy, and similarly decreased levels of TH and ChAT. Even at a single time-point, severity of morphological phenotype correlates with progression of molecular and electrophysiological changes, with the most hypertrophied hearts showing the most severe changes that might be related to arrhythmogenesis.

• Publikační typ
• časopisecké články MeSH

Adaptation to continuous normobaric hypoxia (CNH) protects the heart against ischemia/reperfusion injury but much less is known about its potential therapeutic effects. The aim of this study was to find out whether post-infarction exposure to CNH can attenuate the progression of heart failure. Ten-week-old male rats underwent myocardial infarction (MI) or sham operation. MI was induced by 60-min coronary artery occlusion. Seven days post-MI, the rats were randomly assigned to two groups: i) sedentary controls kept at room air and ii) rats exposed to CNH (12 % O(2), 3 weeks). Echocardiographic examination of the left ventricle (LV) was performed 3 days before surgery and 7, 14 and 28 days post-MI. MI resulted in a gradual increase in LV end-diastolic diameter (LVD(d)) compared to sham-operated animals. Fractional shortening (FS) decreased from 42.8 % before MI to 15.1 % on day 28 post-MI. CNH significantly attenuated ventricular dilatation without affecting scar area and FS. Our data suggest that prolonged exposure to CNH has certain potential to attenuate the progression of unfavorable changes in ventricular geometry induced by MI in rats.

• MeSH
• hypoxie * MeSH
• infarkt myokardu komplikace   terapie   MeSH
• náhodné rozdělení MeSH
• potkani Wistar MeSH
• remodelace komor * MeSH
• reperfuzní poškození myokardu komplikace   terapie   MeSH
• srdeční selhání etiologie   prevence a kontrola   MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH