Diabetes mellitus is known to produce various cell-damaging events and thereby underlie heart dysfunction and remodeling. However, very little is known about its inflammation-associated pathomechanisms due to necrosis-like cell death. For this purpose, we aimed to investigate signaling pathways of necroptosis and pyroptosis, known to produce plasma membrane rupture with the resultant promotion of inflammation. One-year old Zucker diabetic fatty (ZDF) rats did not exhibit significant heart dysfunction as revealed by echocardiographic measurement. On the other hand, there was a decrease in heart rate due to diabetes. Immunoblotting analysis showed that the left ventricles of ZDF rats overexpress neither the main necroptotic proteins including receptor-interacting protein kinase 3 (RIP3) and mixed lineage domain kinase-like pseudokinase (MLKL), nor the pyroptotic regulators including NLR family pyrin domain containing 3 protein (NLRP3), caspase-1, interleukin-1 beta (IL-1beta and the N-terminal gasdermin D (GSDMD-N). On the other hand, the increased activation of the RIP3 kinase due to phosphorylation was found in such hearts. In summary, we showed for the first time that the activation of cardiac RIP3 is upregulated due to disturbances in glucose metabolism which, however, did not proceed to necrosis-like cell death. These data can indicate that the activated RIP3 might also underlie other pleiotropic, non-necroptotic signaling pathways under basal conditions.
While necroptosis has been shown to contribute to the pathogenesis of post-infarction heart failure (HF), the role of autophagy remains unclear. Likewise, linkage between these two cell death modalities has not been sufficiently investigated. HF was induced by 60-min left coronary occlusion in adult Wistar rats and heart function was assessed 6 weeks later followed by immunoblotting analysis of necroptotic and autophagic proteins in both the left (LV) and right ventricle (RV). HF had no effect on RIP1 and RIP3 expression. PhosphoSer229-RIP3, acting as a pro-necroptotic signal, was increased in LV while deceased in RV of failing hearts. Total MLKL was elevated in RV only. Decrease in pSer555-ULK1, increase in pSer473-Akt and no significant elevation in beclin-1 and LC3-II/I ratio indicated rather a lowered rate of autophagy in LV. No beclin-1 upregulation and decreased LC3 processing also suggested the inhibition of both autophagosome formation and maturation in RV of failing hearts. In contrast, p89 PARP1 fragment, a marker of executed apoptosis, was increased in RV only. This is the first study showing a different signaling in ventricles of the late phase of post-infarction HF, highlighting necroptosis itself rather than its linkage with autophagy in LV, and apoptosis in RV.
- MeSH
- apoptóza * fyziologie MeSH
- autofagie fyziologie MeSH
- infarkt myokardu komplikace patologie MeSH
- nekroptóza fyziologie MeSH
- potkani Sprague-Dawley MeSH
- potkani Wistar MeSH
- protein-serin-threoninkinasy interagující s receptory metabolismus MeSH
- protein-serin-threoninkinasy metabolismus MeSH
- signální transdukce MeSH
- srdeční komory patologie MeSH
- srdeční selhání etiologie metabolismus patologie MeSH
- velikost orgánu MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
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
- protein-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
- Publikační typ
- abstrakt z konference MeSH
Currently, there are no satisfactory interventions to protect the heart against the detrimental effects of ischemia-reperfusion injury. Although ischemic preconditioning (PC) is the most powerful form of intrinsic cardioprotection, its application in humans is limited to planned interventions, due to its short duration and technical requirements. However, many organs/tissues are capable of producing "remote" PC (RPC) when subjected to brief bouts of ischemia-reperfusion. RPC was first described in the heart where brief ischemia in one territory led to protection in other area. Later on, RPC started to be used in patients with acute myocardial infarction, albeit with ambiguous results. It is hypothesized that the connection between the signal triggered in remote organ and protection induced in the heart can be mediated by humoral and neural pathways, as well as via systemic response to short sublethal ischemia. However, although RPC has a potentially important clinical role, our understanding of the mechanistic pathways linking the local stimulus to the remote organ remains incomplete. Nevertheless, RPC appears as a cost-effective and easily performed intervention. Elucidation of protective mechanisms activated in the remote organ may have therapeutic and diagnostic implications in the management of myocardial ischemia and lead to development of pharmacological RPC mimetics.
- MeSH
- časové faktory MeSH
- infarkt myokardu metabolismus patologie patofyziologie prevence a kontrola MeSH
- ischemické přivykání metody MeSH
- lidé MeSH
- modely nemocí na zvířatech MeSH
- myokard metabolismus patologie MeSH
- regionální krevní průtok MeSH
- reperfuzní poškození myokardu metabolismus patologie patofyziologie prevence a kontrola MeSH
- signální transdukce MeSH
- výsledek terapie MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- přehledy 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
- protein-serin-threoninkinasy interagující s receptory metabolismus MeSH
- proteinkinasy metabolismus MeSH
- proteiny vázající RNA metabolismus MeSH
- signální transdukce MeSH
- TNF-alfa metabolismus MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
Inhibition of receptor-interacting serine/threonine-protein kinase 1 (RIP1) by necrostatin-1 (Nec-1) alleviates cardiac injury due to prevention of necroptotic cell death. Its inactive analogue necrostatin-1i (Nec-1i), lacking RIP1 activity, serves as a suitable control. It is unknown if these agents influence the heart function in the absence of damaging stimuli. For this purpose, we measured intraarterial blood pressure (systolic - sBP and diastolic - dBP) and ECG parameters after a bolus administration of Nec-1 and Nec-1i in rats during 30 min. Nec-1, unlike Nec-1i, increased sBP and dBP, as well as heart rate reaching the peak at 20 min. The P wave duration tended to be decreased and the duration of the PR interval was shortened by Nec-1 indicating faster conduction of the impulses through atria to the ventricles. The drugs did not influence the QTc interval duration and no episode of ventricular arrhythmia was observed. In summary, Nec-1 temporarily modulates blood pressure and electrical function of the healthy heart. These effects of Nec-1 are likely due to its off-target action or RIP1 has an important role in the regulation of cardiovascular function independently of its action on the necroptotic pathway.
- MeSH
- elektrokardiografie MeSH
- imidazoly farmakologie MeSH
- indoly farmakologie MeSH
- krevní tlak účinky léků MeSH
- náhodné rozdělení MeSH
- potkani Wistar MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Publikační typ
- abstrakt z konference MeSH
Although pleiotropy, which is defined as multiple effects derived from a single gene, was recognized many years ago, and considerable progress has since been achieved in this field, it is not very clear how much this feature of a drug is clinically relevant. During the last decade, beneficial pleiotropic effects from hypolipidemic drugs (as in, effects that are different from the primary ones) have been associated with reduction of cardiovascular risk. As with statins, the agonists of peroxisome proliferator-activated receptors (PPARs), niacin and fibrates, have been suggested to exhibit pleiotropic activity that could significantly modify the outcome of a cardiovascular ailment. This review examines findings demonstrating the impacts of treatment with hypolipidemic drugs on cardiac response to ischemia in a setting of acute ischemia-reperfusion, in relation to PPAR activation. Specifically, it addresses the issue of susceptibility to ischemia, with particular regard to the preconditioning-like cardioprotection conferred by hypolipidemic drugs, as well as the potential molecular mechanisms behind this cardioprotection. Finally, the involvement of PPAR activation in the mechanisms of non-metabolic cardioprotective effects from hypolipidemic drugs, and their effects on normal and pathologically altered myocardium (in the hearts of hypertensive rats) is also discussed.
- MeSH
- hypertenze komplikace farmakoterapie metabolismus MeSH
- hypolipidemika aplikace a dávkování farmakologie terapeutické užití MeSH
- ischemické přivykání * MeSH
- kardiotonika aplikace a dávkování farmakologie terapeutické užití MeSH
- krysa rodu rattus MeSH
- metabolismus lipidů účinky léků MeSH
- modely nemocí na zvířatech MeSH
- receptory aktivované proliferátory peroxizomů metabolismus MeSH
- reperfuzní poškození myokardu etiologie metabolismus prevence a kontrola MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- přehledy MeSH
UNLABELLED: Genes encoding enzymes involved in fatty acids (FA) and glucose oxidation are transcriptionally regulated by peroxisome proliferator-activated receptors (PPAR), members of the nuclear receptor superfamily. Under conditions associated with O(2) deficiency, PPAR-alpha modulates substrate switch (between FA and glucose) aimed at the adequate energy production to maintain basic cardiac function. Both, positive and negative effects of PPAR-alpha activation on myocardial ischemia/reperfusion (I/R) injury have been reported. Moreover, the role of PPAR-mediated metabolic shifts in cardioprotective mechanisms of preconditioning (PC) is relatively less investigated. We explored the effects of PPAR-alpha upregulation mimicking a delayed "second window" of PC on I/R injury in the rat heart and potential downstream mechanisms involved. Pretreatment of rats with PPAR-alpha agonist WY-14643 (WY, 1 mg/kg, i.p.) 24 h prior to I/R reduced post-ischemic stunning, arrhythmias and the extent of lethal injury (infarct size) and apoptosis (caspase-3 expression) in isolated hearts exposed to 30-min global ischemia and 2-h reperfusion. Protection was associated with remarkably increased expression of PPAR-alpha target genes promoting FA utilization (medium-chain acyl-CoA dehydrogenase, pyruvate dehydrogenase kinase-4 and carnitine palmitoyltransferase I) and reduced expression of glucose transporter GLUT-4 responsible for glucose transport and metabolism. In addition, enhanced Akt phosphorylation and protein levels of eNOS, in conjunction with blunting of cardioprotection by NOS inhibitor L-NAME, were observed in the WY-treated hearts. CONCLUSIONS: upregulation of PPAR-alpha target metabolic genes involved in FA oxidation may underlie a delayed phase PC-like protection in the rat heart. Potential non-genomic effects of PPAR-alpha-mediated cardioprotection may involve activation of prosurvival PI3K/Akt pathway and its downstream targets such as eNOS and subsequently reduced apoptosis.
- MeSH
- krysa rodu rattus MeSH
- myokard metabolismus MeSH
- obnova funkce MeSH
- potkani Wistar MeSH
- PPAR alfa metabolismus MeSH
- pyrimidiny terapeutické užití MeSH
- reperfuzní poškození myokardu metabolismus prevence a kontrola MeSH
- upregulace účinky léků MeSH
- výsledek terapie MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
