Remifentanil preconditioning confers cardioprotection via c-Jun NH2-terminal kinases and extracellular signal regulated kinases pathways in ex-vivo failing rat heart

Borneol promotes berberine-induced cardioprotection in a rat model of myocardial ischemia/reperfusion injury via inhibiting P-glycoprotein expression

Berberine is reported to protect the heart against ischemia/reperfusion (I/R) injury, although efficacy is limited by low bioavailability. This study aims to determine whether borneol, a classic guiding drug, can enhance the cardioprotection induced by berberine and to clarify the underlying mechanisms involving P-glycoprotein (P-gp) in the heart. Adult male Sprague Dawley rats were gavaged with berberine (200 mg/kg) with or without borneol (100 mg/kg) for 7 consecutive days. A rat model of myocardial I/R injury was established by 30 min left coronary artery occlusion followed with 120 min reperfusion. The arrhythmia score, cardiac enzyme content, and myocardial infarct size were determined following reperfusion. Heart tissues were collected for Western blot and immunofluorescence analyses to measure the protein expression levels of Bcl-2, Bax, and P-gp. The results showed that administration of berberine protected the heart against I/R injury, as demonstrated by lower arrhythmia scores, serum cTnI contents, myocardial infarct size, and cardiomyocytes apoptosis. Moreover, borneol substantially enhanced the cardioprotective effects of berberine. Western blot and immunofluorescence analyses showed that both berberine and I/R injury did not alter P-gp expression in heart. In contrast, borneol combined with berberine significantly reduced P-gp levels by 43.4% (P = 0.0240). Interestingly, treatment with borneol alone decreased P-gp levels, but did not protect against myocardial I/R injury. These findings suggest that borneol, as an adjuvant drug, improved the cardioprotective effects of berberine by inhibiting P-gp expression in heart. Borneol combined with berberine administration provides a new strategy to protect the heart against I/R injury.

Mitochondrial Kinase Signaling for Cardioprotection

Myocardial ischemia/reperfusion injury is reduced by cardioprotective adaptations such as local or remote ischemic conditioning. The cardioprotective stimuli activate signaling cascades, which converge on mitochondria and maintain the function of the organelles, which is critical for cell survival. The signaling cascades include not only extracellular molecules that activate sarcolemmal receptor-dependent or -independent protein kinases that signal at the plasma membrane or in the cytosol, but also involve kinases, which are located to or within mitochondria, phosphorylate mitochondrial target proteins, and thereby modify, e.g., respiration, the generation of reactive oxygen species, calcium handling, mitochondrial dynamics, mitophagy, or apoptosis. In the present review, we give a personal and opinionated overview of selected protein kinases, localized to/within myocardial mitochondria, and summarize the available data on their role in myocardial ischemia/reperfusion injury and protection from it. We highlight the regulation of mitochondrial function by these mitochondrial protein kinases.

Evaluating the association between opium abuse, blood lead levels, and the complexity of coronary artery disease

Opium abuse and exposure to heavy metals elevate the risk of coronary artery disease (CAD). Therefore, we aimed to determine the association between opium abuse and blood lead levels (BLLs) and the CAD complexity. We evaluated patients with acute coronary symptoms who underwent coronary angiography, and those with >50% stenosis in at least one of the coronary arteries were included. Furthermore, Synergy between PCI with Taxus and Cardiac Surgery I (SYNTAX I) score and BLLs were measured. Based on the opium abuse, 95 patients were subdivided into opium (45) and control (50) groups. Differences in demographics and CAD risk factors were insignificant between the two groups. The median BLLs were remarkably higher in the opium group than in controls (36 (35.7) and 20.5 μg/dL (11.45), respectively, p = 0.003). We also revealed no significant differences in SYNTAX score between the two groups (15.0 (9.0) and 17.5 (14.0), respectively, p = 0.28). Additionally, we found no significant correlation between BLLs and the SYNTAX scores (p = 0.277 and r = -0.113). Opium abuse was associated with high BLLs. Neither opium abuse nor high BLLs were correlated with the complexity of CAD. Further studies are warranted to establish better the relationship between opium abuse, BLLs, and CAD.

Targeting the opioid remifentanil: Protective effects and molecular mechanisms against organ ischemia-reperfusion injury

Opioids are widely used in clinical practice by activating opioid receptors (OPRs), but their clinical application is limited by a series of side effects. Researchers have been making tremendous efforts to promote the development and application of opioids. Fortunately, recent studies have identified the additional effects of opioids in addition to anesthesia and analgesia, particularly in terms of organ protection against ischemia-reperfusion (I/R) injury, with unique advantages. I/R injury in vital organs not only leads to cell dysfunction and structural damage but also induces acute and chronic organ failure, even death. Early prevention and appropriate therapeutic targets for I/R injury are crucial for organ protection. Opioids have shown cardioprotective effects for over 20 years, especially remifentanil, a derivative of fentanyl, which is a new ultra-short-acting opioid analgesic widely used in clinical anesthesia induction and maintenance. In this review, we provide current knowledge about the physiological effects related to OPR-mediated organ protection, focusing on the protective effect and mechanism of remifentanil on I/R injury in the heart and other vital organs. Herein, we also explored the potential application of remifentanil in clinical I/R injury. These findings provide a theoretical basis for the use of remifentanil to inhibit or alleviate organ I/R injury during the perioperative period and provide insights for opioid-induced human organ protection and drug development.

Plasma exosomes generated by ischaemic preconditioning are cardioprotective in a rat heart failure model

BACKGROUND

Exosomes released into the plasma after brief cardiac ischaemia mediate subsequent cardioprotection. Whether donor exosomes can provide cardioprotection to recipients with chronic heart failure, which confers the highest perioperative risk, is unknown. We examined whether ischaemic preconditioning (IPC)-induced plasma exosomes exerted cardioprotection after their transfer from normal donors to post-infarcted failing hearts.

METHODS

Plasma exosomes were obtained from adult rats after IPC or sham. An exosome inhibitor GW4869 was administrated before IPC in an in vivo model of ischaemia/reperfusion (I/R) injury in normal rats. The IPC exosomes or control exosomes from normal donor rats were perfused to the normal or post-infarcted failing rat hearts before ischaemia in Langendorff perfusion experiments. Infarct size, cardiac enzymes, cardiac function, and pro-survival kinases were quantified.

RESULTS

The IPC stimulus increased the release of exosomes, whereas GW4869 inhibited the rise of plasma exosomes. Pre-treatment with GW4869 reversed IPC-mediated cardioprotection against in vivo I/R injury. In the Langendorff perfusion experiments, IPC exosomes from normal donor rats reduced mean infarct size from 41.05 (1.87)% to 31.43 (1.81)% and decreased lactate dehydrogenase activity in the post-infarcted failing rat hearts. IPC exosomes but not control exosomes activated pro-survival kinases in the heart tissues.

CONCLUSIONS

Ischaemic preconditioning-induced exosomes from normal rats can restore cardioprotection in heart failure after myocardial infarction, which is associated with activation of pro-survival protein kinases. These results suggest a potential perioperative therapeutic role for ischaemic preconditioning-induced exosomes.

Remifentanil protects heart from myocardial ischaemia/reperfusion (I/R) injury via miR-206-3p/TLR4/NF-κB signalling axis

OBJECTIVES

Myocardial I/R injury is one of the most serious complications after reperfusion therapy in patients with myocardial infarction. Remifentanil has been found to protect the heart against I/R injury. However, its underlying mechanism remains uncertain in myocardial I/R injury.

METHODS

The myocardial I/R injury rat model was established by 30 min of ischaemia followed by 24 h of reperfusion. The animal model was evaluated by the levels of TC, ALT and AST and H&E staining. The binding of miR-206-3p and TLR4 was predicted and verified using TargetScan software, luciferase reporter and RNA pull-down assays. The functional role and mechanism of remifentanil were identified by ultrasonic echocardiography, oxidative stress markers, H&E, Masson and TUNEL staining and western blot.

KEY FINDINGS

The rat myocardial I/R injury model displayed a significantly high level of TC, ALT, AST, TLR4, p-IκBα and p-p65 and the presence of disorganized cells and inflammatory cell infiltration. The model also showed increased levels of LVEDD, LVESD, MDA, fibrosis and apoptosis and decreased levels of EF, FS, SOD and GSH, which were reversed with remifentanil treatment. Knockdown of miR-206-3p damaged cardiac function and aggravated oxidative stress. miR-206-3p could directly bind to TLR4. TLR4 overexpression destroyed cardiac function, exacerbated oxidative stress, increased levels of p-IκBα and p-p65 and aggravated pathology manifestation affected by remifentanil.

CONCLUSIONS

Our results elucidated that remifentanil alleviated myocardial I/R injury by miR-206-3p/TLR4/NF-κB signalling axis.

Pharmacological Conditioning of the Heart: An Update on Experimental Developments and Clinical Implications

The aim of pharmacological conditioning is to protect the heart against myocardial ischemia-reperfusion (I/R) injury and its consequences. There is extensive literature that reports a multitude of different cardioprotective signaling molecules and mechanisms in diverse experimental protocols. Several pharmacological agents have been evaluated in terms of myocardial I/R injury. While results from experimental studies are immensely encouraging, translation into the clinical setting remains unsatisfactory. This narrative review wants to focus on two aspects: (1) give a comprehensive update on new developments of pharmacological conditioning in the experimental setting concentrating on recent literature of the last two years and (2) briefly summarize clinical evidence of these cardioprotective substances in the perioperative setting highlighting their clinical implications. By directly opposing each pharmacological agent regarding its recent experimental knowledge and most important available clinical data, a clear overview is given demonstrating the remaining gap between basic research and clinical practice. Finally, future perspectives are given on how we might overcome the limited translatability in the field of pharmacological conditioning.

[Perioperative cardioprotection - From bench to bedside : Current experimental evidence and possible reasons for the limited translation into the clinical setting]

Hintergrund

Ziel der perioperativen Kardioprotektion ist es, die Auswirkungen eines Ischämie- und Reperfusionsschadens zu minimieren. Aus anästhesiologischer Sicht spielt dieser Aspekt insbesondere in der Herzchirurgie bei Patienten mit Einsatz der Herz-Lungen-Maschine, aber auch allgemein bei längerfristigen hypotensiven Phasen oder perioperativen ischämischen Ereignissen im nichtkardiochirurgischen Setting eine wichtige Rolle. Im Laufe der letzten Jahre konnten diverse pharmakologische sowie nichtpharmakologische Strategien der Kardioprotektion identifiziert werden. Die Ergebnisse von Studien an isoliertem Gewebe sowie von tierexperimentellen In-vivo-Studien sind vielversprechend. Eine Translation dieser kardioprotektiven Strategien in die klinische Praxis ist bislang jedoch nicht gelungen. Große klinische Studien konnten keine signifikante Verbesserung des Outcome der Patienten zeigen.

Ziel der Arbeit

Dieser Übersichtsartikel gibt einen Überblick über die aktuelle experimentelle Evidenz pharmakologischer und nichtpharmakologischer Kardioprotektion. Außerdem sollen mögliche Gründe für die limitierte Translation diskutiert werden. Schließlich werden Möglichkeiten aufgezeigt, wie der Schritt „from bench to bedside“ in Zukunft doch noch gelingen könnte.

Material und Methoden

Narrative Übersichtsarbeit.

Ergebnisse und Diskussion

Trotz der vielversprechenden präklinischen experimentellen Ansätze zum Thema Kardioprotektion besteht nach wie vor eine große Diskrepanz zu den Ergebnissen aus großen klinischen Studien in der perioperativen Phase. Mögliche Gründe für die limitierte Translation könnten insbesondere Komorbiditäten und Komedikationen, die Wahl des Anästhesieverfahrens, aber auch die Wahl des Studiendesigns sein. Eine sorgfältige Studienplanung mit Berücksichtigung der genannten Probleme sowie ein simultaner Einsatz mehrerer kardioprotektiver Strategien mit dem Ziel eines additiven bzw. synergistischen Effekts stellen mögliche Ansätze für die Zukunft dar.

Perioperative Cardioprotection: General Mechanisms and Pharmacological Approaches

Cardioprotection encompasses a variety of strategies protecting the heart against myocardial injury that occurs during and after inadequate blood supply to the heart during myocardial infarction. While restoring reperfusion is crucial for salvaging myocardium from further damage, paradoxically, it itself accounts for additional cell death-a phenomenon named ischemia/reperfusion injury. Therefore, therapeutic strategies are necessary to render the heart protected against myocardial infarction. Ischemic pre- and postconditioning, by short periods of sublethal cardiac ischemia and reperfusion, are still the strongest mechanisms to achieve cardioprotection. However, it is highly impractical and far too invasive for clinical use. Fortunately, it can be mimicked pharmacologically, for example, by volatile anesthetics, noble gases, opioids, propofol, dexmedetomidine, and phosphodiesterase inhibitors. These substances are all routinely used in the clinical setting and seem promising candidates for successful translation of cardioprotection from experimental protocols to clinical trials. This review presents the fundamental mechanisms of conditioning strategies and provides an overview of the most recent and relevant findings on different concepts achieving cardioprotection in the experimental setting, specifically emphasizing pharmacological approaches in the perioperative context.

Remifentanil up-regulates HIF1α expression to ameliorate hepatic ischaemia/reperfusion injury via the ZEB1/LIF axis

Ischaemia/reperfusion (I/R)-induced hepatic injury is regarded as a main reason of hepatic failure after transplantation or lobectomy. The current study aimed to investigate how the opioid analgesic remifentanil treatment affects I/R-induced hepatic injury and explore the possible mechanisms related to HIF1α. Initially, an I/R-induced hepatic injury animal model was established in C57BL/6 mice, and an in vitro hypoxia-reoxygenation model was constructed in NCTC-1469 cells, followed by remifentanil treatment and HIF1α silencing treatment. The levels of blood glucose, lipids, alanine transaminase (ALT) and aspartate transaminase (AST) in mouse serum were measured using automatic chemistry analyser, while the viability and apoptosis of cells were detected using CCK8 assay and flow cytometry. Our results revealed that mice with I/R-induced hepatic injury showed higher serum levels of blood glucose, lipids, ALT and AST and leukaemia inhibitory factor (LIF) expression, and lower HIF1α and ZEB1 expression (P < .05), which were reversed after remifentanil treatment (P < .05). Besides, HIF1α silencing increased the serum levels of blood glucose, lipids, ALT and AST (P < .05). Furthermore, hypoxia-induced NCTC-1469 cells exhibited decreased HIF1α and ZEB1 expression, reduced cell viability, as well as increased LIF expression and cell apoptosis (P < .05), which were reversed by remifentanil treatment (P < .05). Moreover, HIF1α silencing down-regulated ZEB1 expression, decreased cell viability, and increased cell apoptosis (P < .05). ZEB1 was identified to bind to the promoter region of LIF and inhibit its expression. In summary, remifentanil protects against hepatic I/R injury through HIF1α and downstream effectors.

Remifentanil preconditioning protects against hypoxia-induced senescence and necroptosis in human cardiac myocytes in vitro

Remifentanil and other opioids are suggested to be protective against ischemia-reperfusion injury in animal models and coronary artery bypass surgery patients, however the molecular basis of such protection is far from being understood. In the present study, we have used a model of human cardiomyocytes treated with the hypoxia-mimetic agent cobalt chloride to investigate remifentanil preconditioning-based adaptive responses and underlying mechanisms. Hypoxic conditions promoted oxidative and nitrosative stress, p21-mediated cellular senescence and the activation of necroptotic pathway that was accompanied by a 2.2-, 9.6- and 8.2-fold increase in phosphorylation status of mixed lineage kinase domain-like pseudokinase (MLKL) and release of pro-inflammatory cytokine IL-8 and cardiac troponin I, a marker of myocardial damage, respectively. Remifentanil preconditioning was able to lower hypoxia-mediated protein carbonylation and limit MLKL-based signaling and pro-inflammatory response to almost normoxic control levels, and decrease hypoxia-induced pro-senescent activity of about 21% compared to control hypoxic conditions. In summary, we have shown for the first time that remifentanil can protect human cardiomyocytes against hypoxia-induced cellular senescence and necroptosis that may have importance with respect to the use of remifentanil to diminish myocardial ischemia and reperfusion injury in patients undergoing cardiac surgery.

Dimethyl fumarate attenuates lipopolysaccharide-induced mitochondrial injury by activating Nrf2 pathway in cardiomyocytes

AIMS

To determine whether dimethyl fumarate (DMF) can protect against lipopolysaccharide (LPS) -induced myocardial injury.

MAIN METHODS

H9c2 cells pretreated with or without DMF were stimulated with LPS. Cell viability and apoptosis were evaluated. Nrf2 and HO-1 expression were detected using Western blotting. Mitochondrial morphology, mitochondrial superoxide production were observed using confocal microscope. Mitochondrial respiration function was measured using Seahorse bioanalyzer.

KEY FINDINGS

(1) The cell viability decreased, LDH release and apoptosis increased in LPS- challenged H9c2 cells. DMF pretreatment brought a higher cell viability, and a lower LDH leakage and apoptosis than those of LPS group (P < 0.01). (2) DMF pretreatment resulted in an increased Nrf2 and HO-1 expression, and enhanced nuclear Nrf2 level in LPS-challenged cells (P < 0.01). (3) Nrf2-siRNA could inhibit DMF-induced enhancement of HO-1 expression and cell viability, and partly abolish DMF-induced reduction of LDH leakage and apoptosis. (4) ERK1/2 inhibitor PD98059 could not only prevent the DMF-induced enhancement of nuclear Nrf2 and HO-1, but also inhibit DMF-induced increase in cell viability. (5) Compared with LPS-challenged cells, DMF pretreatment caused a lower production of mitochondrial superoxide and a higher mitochondrial membrane potential, which could be abolished by Nrf2-siRNA. (6) DMF could attenuate LPS-induced mitochondrial fragmentation and improve mitochondrial respiration function by enhancement of the oxygen consumption rate of basal respiration and ATP production in LPS-challenged cells (P < 0.01).

SIGNIFICANCE

DMF protects cardiomyocytes against LPS-induced damage. ERK1/2-dependent activation of Nrf2/HO-1 pathway is responsible for DMF-induced cardioprotection via reduction of oxidative stress, improvement of mitochondrial morphology and energy metabolism.