Remifentanil protects liver against ischemia/reperfusion injury through activation of anti-apoptotic pathways

Remifentanil represses oxidative stress to relieve hepatic ischemia/reperfusion injury via regulating BACH1/PRDX1 axis

BACKGROUND

Hepatic ischemia-reperfusion injury (HIRI) is a major cause of liver dysfunction after clinical liver surgery, which seriously affects the prognosis of patients. Remifentanil (RE) has been verified to attenuate HIRI. However, its therapeutic mechanism is still unclear. This study aimed to explore the protective mechanism of RE against HIRI.

METHODS

A mouse HIRI model and an in vitro model of hypoxia/reoxygenation (H/R)-stimulated AML12 hepatocytes were established. Liver histopathological changes were evaluated by hematoxylin and eosin (HE) staining. Oxidative stress damage was assessed by malondialdehyde (MDA), superoxide dismutase (SOD), and reactive oxygen species (ROS) levels. Liver function was determined by serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), lactate dehydrogenase (LDH). and adenosine triphosphate (ATP) levels. Cell counting kit-8 (CCK-8) assessed cell viability. Apoptosis was measured by terminal-deoxynucleoitidyl transferase mediated nick end labeling (TUNEL) and flow cytometry. The levels of inflammatory factors were detected by enzyme-linked immunosorbent assay (ELISA) kits. The differentially expressed genes were evaluated by mRNA microarray analysis. Western blotting and real-time quantitative polymerase chain reaction (RT-qPCR) were conducted to detect molecule expression. The binding of BTB and CNC homology 1 (BACH1) to peroxiredoxin 1 (PRDX1) was validated by chromatin immunoprecipitation (ChIP) and dual luciferase reporter assay.

RESULTS

RE treatment improved liver function, and repressed oxidative stress damage and apoptosis in HIRI mice. Nine differentially expressed genes in the liver tissues of HIRI mice were selected by microarray analysis, among which BACH1 was down-regulated and PRDX1 was up-regulated after RE treatment. In addition, BACH1 directly bound to the promoter region of PRDX1 to inhibit its transcription and expression, which led to oxidative stress injury. BACH1 overexpression or PRDX1 silencing could counteract the beneficial effects of RE against HIRI.

CONCLUSION

RE suppressed oxidative stress injury and inflammation via inactivation of the BACH1/PRDX1 axis, thereby ameliorating HIRI. Our findings enrich the understanding of the protective mechanisms of RE against HIRI, and provide novel evidence for its clinical application.

Inhibitory role of remifentanil in hepatic ischemia-reperfusion injury through activation of Fmol/Parkin signaling pathway: A study based on network pharmacology analysis and high-throughput sequencing

BACKGROUND

This study was conducted to elucidate the critical molecular pathways underlying the protective effects of remifentanil against hepatic ischemia-reperfusion injury in rats. Our approach integrated network pharmacology analysis with high-throughput sequencing to achieve a comprehensive understanding of the mechanisms involved.

STUDY DESIGN/METHODS

The study utilized GSE24430 gene expression data from GEO to investigate remifentanil's impact on Hepatic Ischemia-Reperfusion Injury in rats. Weighted Correlation Network Analysis (WGCNA) was employed to pinpoint crucial genes and identify modules of co-expressed genes. Differential analysis with the "Limma" package revealed genes differentially expressed in IRI vs. control groups. PubChem and PharmMapper provided target genes affected by remifentanil. Protein-protein interaction networks were constructed via GeneCards and STRING. Functional analysis pinpointed core genes involved in remifentanil's IRI alleviation. IRI rat models were established, and hepatic injury indicators, liver structure via H&E staining, autophagosome counts via electron microscopy, and gene/protein expression via RT-qPCR and Western blot were assessed. High-throughput sequencing analyzed molecular pathways affected by varying remifentanil doses in IRI rats.

RESULTS

In the study, we discovered four primary co-expression modules associated with hepatic IRI, and the grey module exhibited the highest correlation with hepatic IRI.A total of sixty-eight genes that were differentially expressed were found to have a connection with hepatic IRI.Network pharmacology analysis found that remifentanil may alleviate hepatic IRI through Fmol.found that the Fmol/Parkin signaling pathway may alleviate hepatic IRI via Additionally, the database autophagy. The established hepatic IRI rat models further confirmed the above findings.

CONCLUSION

Our study established that remifentanil triggers the Fmol/Parkin signaling cascade, amplifying the expression levels of Fmol and Parkin. This process culminates in the activation of autophagy within hepatic cells, ultimately alleviating hepatic ischemia-reperfusion injury (IRI).

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.

The Impact of General Anesthesia on Redox Stability and Epigenetic Inflammation Pathways: Crosstalk on Perioperative Antioxidant Therapy

Worldwide, the prevalence of surgery under general anesthesia has significantly increased, both because of modern anesthetic and pain-control techniques and because of better diagnosis and the increased complexity of surgical techniques. Apart from developing new concepts in the surgical field, researchers and clinicians are now working on minimizing the impact of surgical trauma and offering minimal invasive procedures due to the recent discoveries in the field of cellular and molecular mechanisms that have revealed a systemic inflammatory and pro-oxidative impact not only in the perioperative period but also in the long term, contributing to more difficult recovery, increased morbidity and mortality, and a negative financial impact. Detailed molecular and cellular analysis has shown an overproduction of inflammatory and pro-oxidative species, responsible for augmenting the systemic inflammatory status and making postoperative recovery more difficult. Moreover, there are a series of changes in certain epigenetic structures, the most important being the microRNAs. This review describes the most important molecular and cellular mechanisms that impact the surgical patient undergoing general anesthesia, and it presents a series of antioxidant therapies that can reduce systemic inflammation.

Role of Mitochondrial Pathways in Cell Apoptosis during He-Patic Ischemia/Reperfusion Injury

Hepatic ischemia-reperfusion injury is a major cause of post-operative hepatic dysfunction and liver failure after transplantation. Mitochondrial pathways can be either beneficial or detrimental to hepatic cell apoptosis during hepatic ischemia/reperfusion injury, depending on multiple factors. Hepatic ischemia/reperfusion injury may be induced by opened mitochondrial permeability transition pore, released apoptosis-related proteins, up-regulated B-cell lymphoma-2 gene family proteins, unbalanced mitochondrial dynamics, and endoplasmic reticulum stress, which are integral parts of mitochondrial pathways. In this review, we discuss the role of mitochondrial pathways in apoptosis that account for the most deleterious effect of hepatic ischemia/reperfusion injury.

Remifentanil Promotes PDIA3 Expression by Activating p38MAPK to Inhibit Intestinal Ischemia/Reperfusion-Induced Oxidative and Endoplasmic Reticulum Stress

Background: Remifentanil protects against intestinal ischemia/reperfusion (I/R) injury; however, its exact mechanism remains to be elucidated. The objective of this study was to investigate the underlying molecular mechanism of remifentanil in intestinal I/R injury in mice.

Methods: We evaluated the intestine-protective effect of remifentanil in adult male mice with 45 min superior mesenteric artery occlusion followed by 4 h reperfusion by determining the following: intestinal Chiu’s scores, diamine oxidase, and intestinal fatty acid binding protein in serum; the apoptotic index, lipid peroxidation product malondialdehyde (MDA), and superoxide dismutase (SOD) activity in the intestinal mucosa; and the intestinal mRNA and protein expressions of Bip, CHOP, caspase-12, and cleaved caspase-3, reflecting endoplasmic reticulum (ER) stress. Furthermore, conditional knockout mice, in which the protein disulfide isomerase A3 (PDIA3) gene was deleted from the intestinal epithelium, and SB203580 (a selective p38MAPK inhibitor) were used to determine the role of PDIA3 and p38MAPK in I/R progression and intestinal protection by remifentanil.

Results: Our data showed that intestinal I/R induced obvious oxidative stress and endoplasmic reticulum stress–related cell apoptosis, as evidenced by an increase in the intestinal mucosal malondialdehyde, a decrease in the intestinal mucosal SOD, and an increase in the apoptotic index and the mRNA and protein expression of Bip, CHOP, caspase-12, and cleaved caspase-3. Remifentanil significantly improved these changes. Moreover, the deletion of intestinal epithelium PDIA3 blocked the protective effects of remifentanil. SB203580 also abolished the intestinal protection of remifentanil and downregulated the mRNA and protein expression of PDIA3.

Conclusion: Remifentanil appears to act via p38MAPK to protect the small intestine from intestinal I/R injury by its PDIA3-mediated antioxidant and anti-ER stress properties.

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.

Methods of Attenuating Ischemia-Reperfusion Injury in Liver Transplantation for Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is one of the most frequent indications for liver transplantation. However, the transplantation is ultimately associated with the occurrence of ischemia-reperfusion injury (IRI). It affects not only the function of the graft but also significantly worsens the oncological results. Various methods have been used so far to manage IRI. These include the non-invasive approach (pharmacotherapy) and more advanced options encompassing various types of liver conditioning and machine perfusion. Strategies aimed at shortening ischemic times and better organ allocation pathways are still under development as well. This article presents the mechanisms responsible for IRI, its impact on treatment outcomes, and strategies to mitigate it. An extensive review of the relevant literature using MEDLINE (PubMed) and Scopus databases until September 2020 was conducted. Only full-text articles written in English were included. The following search terms were used: “ischemia reperfusion injury”, “liver transplantation”, “hepatocellular carcinoma”, “preconditioning”, “machine perfusion”.

Sufentanil Protects the Liver from Ischemia/Reperfusion-Induced Inflammation and Apoptosis by Inhibiting ATF4-Induced TP53BP2 Expression

Liver ischemia-reperfusion (I/R) injury is a pathological process that often occurs during liver and trauma surgery. This study aimed to investigate the protective effect and potential mechanisms of sufentanil on hepatic I/R injury. I/R rat model and hypoxic/reoxygenation (H/R)-induced buffalo rat liver (BRL)-3A cell model were established. Following pretreatment with sufentanil, the enzymatic activities of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) in rat serum and the changes of hepatic histopathology were evaluated to track the extent of liver injury. The levels of inflammatory factors were determined with ELISA kits and RT-qPCR. The infiltration of macrophages was assessed after detecting monocyte chemoattractant protein 1 (MCP-1) and F4/80 expression. Additionally, apoptosis was measured by means of TUNEL staining, and gene expression related to apoptosis was examined using RT-qPCR and western blotting. Then, TP53BP2 was overexpressed in BRL-3A cells exposed to H/R condition to evaluate whether sufentanil defended the liver against injury by regulating TP53BP2 expression. Moreover, the potential binding site of ATF4 on the TP53BP2 promoter was analyzed using JASPAR databases and verified by chromosomal immunoprecipitation (ChIP) assay. Furthermore, TP53BP2 expression and endoplasmic reticulum stress (ERS)-related protein levels were determined after ATF4 was overexpressed in sufentanil-treated BRL-3A cells. Results revealed that sufentanil significantly improved hepatic I/R injury, decreased the levels of inflammatory factors, and alleviated hepatocyte apoptosis. Notably, upregulated TP53BP2 expression was observed in hepatic tissues, and TP53BP2 overexpression markedly reversed the protective effects of sufentanil on the inflammation and apoptosis in H/R-stimulated BRL-3A cells. Additionally, ATF4 was confirmed to combine with the TP53BP2 promoter. ATF4 upregulation attenuated the inhibitory effects of sufentanil on the expression of TP53BP2 and ERS-associated proteins. These findings demonstrated that sufentanil protects the liver from inflammation and apoptosis injury induced by I/R by inhibiting ATF4 expression and further suppressing TP53BP2 expression, suggesting a promising therapeutic candidate for the treatment of liver I/R injury.

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.

Preconditioning Effect of Remifentanil Versus Fentanyl in Prevalence of Early Graft Dysfunction in Patients After Liver Transplant: A Randomized Clinical Trial

OBJECTIVES

One of the most prevalent complications of orthotopic liver transplant is primary graft dysfunction. Recent studies have shown the preconditioning effect of remifentanil on animal livers but not human livers. Here, we compared the preconditioning effects of remifentanil and fentanyl in orthotopic liver transplant in human patients.

MATERIALS AND METHODS

In this double-blind clinical trial, 100 patients who underwent liver transplant from deceased donors were randomly allocated into 2 groups. Patients in the remifentanil group received remifentanil infusion, and those in the fentanyl group received fentanyl infusion during maintenance of anesthesia. Serum aminotransferase levels, prothrombin time (international normalized ratio), partial thrombin time, arterial blood gas levels, and renal function tests were evaluated over 7 days posttransplant. Intensive care unit stay and hospitalization were also recorded.

RESULTS

The median peak alanine aminotransferase level during 7 days after transplant was 2100 U/L (interquartile range, 1230-3220) in the remifentanil group and 3815 U/L (interquartile range, 2385-5675) in the fentanyl group (P = .048). Metabolic acidosis, renal state, prothrombin time (international normalized ratio), and partial thrombin time were similar in both groups (P > .05). Durations of stay in the intensive care unit and hospital were not significantly different between the 2 groups (P = .75 and P = .23, respectively). Overall, the clinical outcomes were similar in the remifentanil and fentanyl groups (P > .05).

CONCLUSIONS

We found that remifentanil and fentanyl were not different with regard to their preconditioning effects and graft protection in orthotopic liver transplant recipients.

Remifentanil Protects against Lipopolysaccharide-Induced Inflammation through PARP-1/NF-κB Signaling Pathway

Sepsis is a leading cause of death in patients with severe infection worldwide. Remifentanil is an ultra-short-acting, potent opioid analgesic. In the study, we aimed to investigate the role and underlying mechanism of remifentanil in lipopolysaccharide- (LPS-) induced inflammation in human aortic endothelial cells (HAECs). HAECs were pretreated with phosphate-buffered saline (PBS) or remifentanil (2.5 μM) for 30 min, then stimulated by LPS (10 μg/ml) for another 24 h. Poly(ADP-ribose) polymerase 1 (PARP-1) was inhibited by small interfering RNA (siRNA). Superoxide anion production and DNA damage were analyzed by dihydroethidium (DHE) staining and comet assay. The inducible nitric oxide synthase (iNOS), intercellular adhesion molecule 1 (ICAM-1), PARP-1, poly(ADP-ribose) (PAR), and nuclear factor-kappa B p65 (NF-κB p65) expressions were analyzed by RT-PCR or western blotting analysis. NF-κB p65 nuclear translocation was assessed by immunofluorescence. Compared with the control group, pretreatment with remifentanil significantly reduced superoxide anion production and DNA damage, with downregulation of iNOS, ICAM-1, and PARP-1 expressions as well as PAR expression. Moreover, pretreatment with PARP-1 siRNA or remifentanil inhibited LPS-induced NF-κB p65 expression and nuclear translocation. Remifentanil reduced LPS-induced inflammatory response through PARP-1/NF-κB signaling pathway. Remifentanil might be an optimal choice of analgesia in septic patients.

Indispensable role of β-arrestin2 in the protection of remifentanil preconditioning against hepatic ischemic reperfusion injury

Our previous study demonstrated that remifentanil, an opioid agonist, conferred profound liver protection during hepatic ischemia reperfusion injury (HIRI), in which Toll-like receptors (TLRs) played a crucial role in mediating the inflammatory responses. β-arrestin2, a well-known mu opioid receptor desensitizer, is also a negatively regulator of Toll-like receptor 4 (TLR4)-mediated inflammatory reactions in a mitogen-activated protein kinase (MAPK)-dependent manner. Using the rodent models of hepatic ischemia reperfusion injury both in wild type and TLR4 knockout (TLR4 KO) mice, we found that remifentanil preconditioning could inhibit the expression of TLR4 and reduce the inflammatory response induced by HIRI in wild type but not in TLR4 KO mice. For the in-vitro study, LPS was used to treat RAW264.7 macrophage cells to mimic the inflammatory response induced by HIRI. Remifentanil increased β-arrestin2 expression both in vivo and in vitro, while after silencing β-arrestin2 RNA, the effect of remifentanil in reducing cell death and apoptosis, as well as decreasing phosphorylation of ERK and JNK were abolished in RAW264.7 cells. These data suggested that remifentanil could ameliorate mice HIRI through upregulating β-arrestin2 expression, which may function as a key molecule in bridging opioid receptor and TLR4 pathway.

Normothermic Machine Perfusion Protects Against Liver Ischemia-Reperfusion Injury During Reduced-Size Liver Transplantation in Pigs

Background

Normothermic machine perfusion (NMP) preservation is superior to cold preservation during reduced-size liver transplantation (RSLT) in pigs. However, the mechanism of this protective effect has not been explained. We aimed to compare the effects of NMP preservation with that of cold preservation (CS) in protecting against ischemia-reperfusion injury (IRI) during RSLT in pigs.

Material/Methods

Twenty-four healthy Bama miniature pigs were randomized into 2 groups: 1) the NMP group in which donor livers harvested without warm ischemia time and cardiac activity were connected to the NMP system to reduce liver size under normothermic conditions, and 2) the CS group in which donor livers harvested without warm ischemia time and cardiac activity were perfused using the University of Wisconsin (UW) solution and then preserved in the 0–4°C UW solution to reduce liver size under cold conditions. Livers were then transplanted without veno-venous bypass. Amounts of bile secretion for the NMP groups were recorded hourly. The serological indices were measured. Expressions of cytochrome C, caspase 3, and NF-κB p65 in liver tissue were observed.

Results

The levels of bile secretions were gradually diminished from 16.50±2.66 mL/h before splitting to 6.35±1.24 mL/h after splitting. With the exception of TNF-α on postoperative day 2, overall, levels of TNF-α, IL-1, IL-6, and MDA were significantly lower in the NMP group versus CS group for all 5 days postoperatively. Finally, cytochrome C, caspase 3, and NF-κB p65 expressions were all significantly suppressed in the NMP group as compared with the CS group.

Conclusions

MP preservation is superior to cold preservation in protecting against liver IRI during RSLT in pigs.

Remifentanil upregulates hepatic IL-18 binding protein (IL-18BP) expression through transcriptional control

Interleukin (IL)-18 plays an important role in liver ischemia/reperfusion (I/R) injury. We have previously demonstrated that remifentanil protects against liver I/R injury by upregulating the hepatic expression of IL-18-binding protein (IL-18BP), a natural IL-18 inhibitor. The current study was performed to further clarify the effects of remifentanil on IL-18BP expression in the liver as well as investigate the underlying mechanisms. In Sprague-Dawley (SD) rats, we demonstrated that remifentanil significantly increased the expression of IL-18BP in normal rat liver tissue over a 24-h time period with maximal expression at 24 h after treatment. The upregulation of remifentanil on IL-18BP expression displayed similar trends in in vitro cellular studies, including mouse primary hepatocytes, normal human hepatocyte LO2, and mouse hepatoma cells Hep1-6. In LO2 cells, preexposure of the cells to remifentanil significantly inhibited IL-18-activated p65 NF-κB phosphorylation, and the inhibition was absent when the cells were transfected with IL-18BP siRNA, indicating the functional effects of IL-18BP induced by remifentanil. Pretreatment with actinomycin D abolished remifentanil-induced upregulation of IL-18BP mRNA, suggesting that the induction occurred at the transcriptional level. This was further supported by the luciferase reporter assay, which demonstrated that remifentanil treatment significantly increased transcription of the IL-18BP promoter. Both western blot analysis and ChIP assays showed that STAT1 and C/EBP β were activated by remifentanil. Furthermore, remifentanil failed to upregulate IL-18BP expression after silencing STAT1 or C/EBP β gene expression. These findings demonstrate that remifentanil could upregulate hepatic IL-18BP expression through transcriptional activation of the IL-18BP promoter, and STAT1 and C/EBP β are two key transcriptional factors involved in this process.

SIRT3 a Major Player in Attenuation of Hepatic Ischemia-Reperfusion Injury by Reducing ROS via Its Downstream Mediators: SOD2, CYP-D, and HIF-1α

Reactive oxygen species (ROS) production in hepatic ischemia-reperfusion injury (IRI) is a complex process where multiple cellular and molecular pathways are involved. Few of those molecular pathways are under the direct influence of SIRT3 and its downstream mediators. SIRT3 plays a major role in the mechanism of IRI, and its activation has been shown to attenuate the deleterious effect of ROS during IRI via SOD2-, CYP-D-, and HIF-1α-mediated pathways. The objective of this review is to analyze the current knowledge on SIRT3 and its downstream mediators: SOD2, CYP-D, and HIF-1α, and their role in IRI. For the references of this review article, we have searched the bibliographic databases of PubMed, Web of Science databases, MEDLINE, and EMBASE with the headings "SIRT3," "SOD2," "CYP-D," "HIF-1α," and "liver IRI." Priority was given to recent experimental articles that provide information on ROS modulation by these proteins. All the recent advancement demonstrates that activation of SIRT3 can suppress ROS production during IRI through various pathways and few of those are via SOD2, CYP-D, and HIF-1α. This effect can improve the quality of the remnant liver following resection as well as a transplanted liver. More research is warranted to disclose its role in IRI attenuation via this pathway.

Remifentanil Preconditioning Attenuates Hepatic Ischemia-Reperfusion Injury in Rats via Neuronal Activation in Dorsal Vagal Complex

Remifentanil, an ultra-short acting opiate, has been reported to protect against hepatic ischemia-reperfusion injury, which is a major cause of postoperative liver dysfunction. The objective of this study was to determine whether a central vagal pathway is involved in this protective procedure. Rat models of hepatic ischemia-reperfusion were used in the experimental procedures. The results revealed that intravenous pretreatment with remifentanil decreased serum aminotransferases and hepatic histologic damage; however, an intraperitoneal injection of μ-opioid receptor antagonist did not abolish the protection of remifentanil preconditioning. c-Fos immunofluorescence of the brain stem showed that dorsal motor nucleus of the vagus was activated after remifentanil preconditioning. Moreover, serum alanine aminotransferase, histopathologic damage, and apoptosis decreased in remifentanil preconditioning group compared to vagotomized animals with remifentanil preconditioning, and there was no statistical difference of TNF-α and IL-6 between NS/Va and RPC/Va groups. In addition, remifentanil microinjection into dorsal vagal complex decreased serum aminotransferases, inflammatory cytokines, and hepatic histologic injury and apoptosis, and these effects were also abolished by a peripheral hepatic vagotomy. In conclusion, remifentanil preconditioning conferred liver protection against ischemia-reperfusion injury, which was mediated by the central vagal pathway.

Addition of Berberine to Preservation Solution in an Animal Model of Ex Vivo Liver Transplant Preserves Mitochondrial Function and Bioenergetics from the Damage Induced by Ischemia/Reperfusion

Liver transplantation is a therapeutic regimen to treat patients with non-malignant end-stage liver diseases and malignant tumors of hepatic origin. The ischemia/reperfusion (I/R) injury in liver transplantation is associated with disruption of mitochondrial function in the hepatic parenchyma. Several studies have been conducted in animal models to identify pharmacological therapeutic strategies to minimize the injury induced by the cold/warm I/R in liver transplantation. Most of these studies were conducted in unrealistic conditions without the potential to be translated to clinical usage. Berberine (BBR) is a pharmacological compound with a potential protective effect of the mitochondrial function in the context of I/R. For the future clinical application of these pharmacological strategies, it is essential that a close resemblance exists between the methodology used in the animals models and real life. In this study, we have demonstrated that the addition of BBR to the preservation solution in an I/R setting preserves mitochondrial function and bioenergetics, protecting the liver from the deleterious effects caused by I/R. As such, BBR has the potential to be used as a pharmacological therapeutic strategy.

Pre-conditions for eliminating mitochondrial dysfunction and maintaining liver function after hepatic ischaemia reperfusion

The liver, the largest organ with multiple synthesis and secretion functions in mammals, consists of hepatocytes and Kupffer, stem, endothelial, stellate and other parenchymal cells. Because of early and extensive contact with the external environment, hepatic ischaemia reperfusion (IR) may result in mitochondrial dysfunction, autophagy and apoptosis of cells and tissues under various pathological conditions. Because the liver requires a high oxygen supply to maintain normal detoxification and synthesis functions, it is extremely susceptible to ischaemia and subsequent reperfusion with blood. Consequently, hepatic IR leads to acute or chronic liver failure and significantly increases the total rate of morbidity and mortality through multiple regulatory mechanisms. An increasing number of studies indicate that mitochondrial structure and function are impaired after hepatic IR, but that the health of liver tissues or liver grafts can be effectively rescued by attenuation of mitochondrial dysfunction. In this review, we mainly focus on the subsequent therapeutic interventions related to the conservation of mitochondrial function involved in mitigating hepatic IR injury and the potential mechanisms of protection. Because mitochondria are abundant in liver tissue, clarification of the regulatory mechanisms between mitochondrial dysfunction and hepatic IR should shed light on clinical therapies for alleviating hepatic IR‐induced injury.

Remifentanil induces autophagy and prevents hydrogen peroxide-induced apoptosis in Cos-7 cells

BACKGROUND

This study investigated the effect of remifentanil pretreatment on Cos-7 cells exposed to oxidative stress, and the influence of remifentanil on intracellular autophagy and apoptotic cell death.

METHODS

Cells were divided into 4 groups: (1) Control: non-pretreated cells were incubated in normoxia (5% CO₂, 21% O₂, and 74% N₂). (2) H₂O₂: non-pretreated cells were exposed to H₂O₂ for 24 h. (3) RPC+H₂O₂: cells pretreated with remifentanil were exposed to H₂O₂ for 24 h. (4) 3-MA+RPC+H₂O₂: cells pretreated with 3-Methyladenine (3-MA) and remifentanil were exposed to H₂O₂ for 24 h. We determined the cell viability of each group using an MTT assay. Hoechst staining and FACS analysis of Cos-7 cells were performed to observe the effect of remifentanil on apoptosis. Autophagy activation was determined by fluorescence microscopy, MDC staining, and AO staining. The expression of autophagy-related proteins was observed using western blotting.

RESULTS

Remifentanil pretreatment increased the viability of Cos-7 cells exposed to oxidative stress. Hoechst staining and FACS analysis revealed that oxidative stress-dependent apoptosis was suppressed by the pretreatment. Additionally, fluorescence microscopy showed that remifentanil pretreatment led to autophagy-induction in Cos-7 cells, and the expression of autophagy-related proteins was increased in the RPC+H₂O₂ group.

CONCLUSIONS

The study showed that remifentanil pretreatment stimulated autophagy and increased viability in an oxidative stress model of Cos-7 cells. Therefore, we suggest that apoptosis was activated upon oxidative stress, and remifentanil preconditioning increased the survival rate of the cells by activating autophagy.

Remifentanil protects uterus against ischemia-reperfusion injury in rats

PURPOSE

To investigate the effects of remifentanil as an antioxidant and analyze the histopathologic, biochemical changes in experimental ischemia-reperfusion (I/R) exposed rat uteri.

METHODS

Wistar albino rats were assigned to three groups (n = 7). 2h period of ischemia was followed by 1h of reperfusion in the I/R and the I/R-remifentanil groups. After ischemia, no drug was administered in the sham and I/R groups. In the I/R-remifentanil group, remifentanil infusion (2 μg/kg/min) was started in the ischemia period, and continued until the end of reperfusion. After the ischemic and reperfusion period, the ischemic uterine horns were removed surgically for biochemical and histopathologic examination. Tissue damage scores (endometrial epithelial glandular leukocytosis, degeneration, and endometrial stromal changes) were examined. Malondialdehyde levels and catalase, superoxide dismutase enzyme activities in tissue were measured.

RESULTS

We found significantly lower epithelial leukocytosis and cell degeneration in the I/R-remifentanil group (p<0.05). Remifentanil administration significantly decreased concentrations of malondialdehyde, and increased catalase and superoxide dismutase enzyme activities (p<0.05).

CONCLUSION

Remifentanil appears to protect the uterine tissue against ischemia-reperfusion and can be used safely in uterus transplantation.

Remifentanil Ameliorates Liver Ischemia-Reperfusion Injury Through Inhibition of Interleukin-18 Signaling

BACKGROUND

Hepatic injury induced by ischemia-reperfusion (I/R) after transplantation or lobectomy is a major clinical problem. The potential benefit of remifentanil in these hepatic surgeries remains unknown. The current study investigated whether remifentanil protects the liver against I/R injury in a rat model and whether the underlying mechanism involves the modulation of interleukin (IL)-18 signaling.

METHODS

Male Sprague-Dawley rats were subjected to 45 minutes of partial hepatic ischemia followed by 6 hours of reperfusion. Then, they received an intravenous saline or remifentanil (0.4, 2, or 10 μg/kg per minute) infusion from 30 minutes before ischemia until the end of ischemia with or without previous administration of naloxone, a nonselective opioid receptor antagonist. Serum aminotransferase, hepatic morphology, and hepatic neutrophil infiltration were analyzed. The expression of hepatic IL-18; IL-18-binding protein (BP); and key cytokines downstream of IL-18 signaling were measured.

RESULTS

Remifentanil significantly decreased serum aminotransferase levels and profoundly attenuated the liver histologic damages. Liver I/R injury increased the expression of both hepatic IL-18 and IL-18BP. Although remifentanil pretreatment significantly decreased I/R-induced IL-18 expression, it further upregulated IL-18BP levels in liver tissues. The I/R-induced increases of hepatic interferon-γ, tumor necrosis factor-α and IL-1β expression, and neutrophil infiltration were also significantly reduced by remifentanil. Naloxone inhibited the remifentanil-induced downregulation of IL-18, but not the elevation of IL-18BP, and significantly attenuated its protective effects on liver I/R injury.

CONCLUSIONS

Remifentanil protects the liver against I/R injury. Modulating the hepatic IL-18/IL-18BP balance and inhibiting IL-18 signaling mediate, at least in part, the hepatoprotective effects of remifentanil.

Remifentanil preconditioning protects the small intestine against ischemia/reperfusion injury via intestinal δ- and μ-opioid receptors

BACKGROUND

Intestinal ischemia/reperfusion (I/R) injury can cause a high rate of mortality in the perioperative period. Remifentanil has been reported to provide protection for organs against I/R injury. We hypothesized that remifentanil preconditioning would attenuate the small intestinal injury induced by intestinal I/R.

METHODS

We used both an in vivo rat model of intestinal I/R injury and a cell culture model using IEC-6 cells (the rat intestinal epithelial cell line) subjected to oxygen and glucose deprivation (OGD). Remifentanil was administered before ischemia or OGD, and 3 specific opioid receptors antagonists, naltrindole (a δ-OR selective antagonist), nor-binaltorphimine (nor-BNI, a κ-OR selective antagonist), and CTOP (a μ-OR selective antagonist), were administered before preconditioning to determine the role of opioid receptors in the intestinal protection mediated by remifentanil.

RESULTS

In the in vivo rat model, intestinal I/R induced obvious intestinal injury as evidenced by increases in the Chiu score, serum diamine oxidase activity, the apoptosis index, and the level of cleaved caspase-3 protein expression, whereas remifentanil preconditioning significantly improved these changes in vivo. In the in vitro cell culture exposed to OGD, cell viability (MTT, ie, (3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide) assay and flow cytometric analysis showed that remifentanil preconditioning enhanced IEC-6 cell viability and decreased apoptosis. In both in vitro and in vivo models, the aforementioned protective effects of remifentanil preconditioning were abolished completely by previous administration of the δ- or μ-opioid markedly attentuated but not the κ-opioid receptor antagonist.

CONCLUSION

Remifentanil preconditioning appears to act via δ- and μ-opioid receptors to protect the small intestine from intestinal I/R injury by attenuating apoptosis of the intestinal mucosal epithelial cells.

Intravenous hypnotic regimens in patients with liver disease; a review article

CONTEXT

The liver as an important organ in the body has many essential functions in physiological processes. One of the major activities of liver is drug metabolism. Hepatic dysfunction affecting hepatic physiological activities, especially drug metabolism can cause many problems during anesthesia and administration of different drugs to patients.

EVIDENCE ACQUISITION

Studies on hepatic disorders and hypnotic anesthetics prescribed in hepatic disorders were included in this review. For this purpose, reliable databases were used.

RESULTS

Anesthesia should be performed with caution in patients with hepatic dysfunction and drugs with long half-life should be avoided in these patients.

CONCLUSIONS

A review of the literature on the use of hypnotic drugs in patients with liver dysfunction showed that some hypnotic drugs used during anesthesia could be safely used in patients with impaired liver function. In these patients, certain drugs should be used with caution.

The effects of spinal, inhalation, and total intravenous anesthetic techniques on ischemia-reperfusion injury in arthroscopic knee surgery

PURPOSE

To compare the effects of different anesthesia techniques on tourniquet-related ischemia-reperfusion by measuring the levels of malondialdehyde (MDA), ischemia-modified albumin (IMA) and neuromuscular side effects.

METHODS

Sixty ASAI-II patients undergoing arthroscopic knee surgery were randomised to three groups. In Group S, intrathecal anesthesia was administered using levobupivacaine. Anesthesia was induced and maintained with sevoflurane in Group I and TIVA with propofol in Group T. Blood samples were obtained before the induction of anesthesia (t1), 30 min after tourniquet inflation (t2), immediately before (t3), and 5 min (t4), 15 min (t5), 30 min (t 6), 1 h (t7), 2 h (t8), and 6 h (t9) after tourniquet release.

RESULTS

MDA and IMA levels increased significantly compared with baseline values in Group S at t2-t 9 and t2-t7. MDA levels in Group T and Group I were significantly lower than those in Group S at t2-t8 and t2-t9. IMA levels in Group T were significantly lower than those in Group S at t2-t7. Postoperatively, a temporary 1/5 loss of strength in dorsiflexion of the ankle was observed in 3 patients in Group S and 1 in Group I.

CONCLUSIONS

TIVA with propofol can make a positive contribution in tourniquet-related ischemia-reperfusion.