Sevoflurane prevents liver inflammatory response induced by lung ischemia-reperfusion

Effects of anesthesia with sevoflurane on outcome parameters in murine experimental studies

PURPOSE

Multiple murine studies modelling the immuno-pathophysiological consequences of trauma, shock, burn or sepsis were performed during the last decades. Almost every animal model requires anesthesia for practical and ethical reasons. Furthermore, often, corresponding control groups involve untreated animals without or with a limited exposure to anesthetics. However, the influences of anesthetic drugs on immuno-pathophysiological reactions remain insufficiently investigated. Therefore, we aimed to closer characterize the anesthetic impact exemplified by sevoflurane on the organ performance in mice and thereby investigate the influence of anesthesia itself on major outcome parameters in animal studies.

METHODS

C57/BL6 mice were subjected either to 270 min of sevoflurane narcosis or directly euthanized. Plasma, BAL-fluids, lungs, kidneys, liver and intestine were collected and examined for immunological, functional and morphological changes.

RESULTS

Systemic levels of the cytokine keratinocyte chemoattractant (KC) were raised in the narcosis group, while concentrations of high mobility group box protein 1 (HMGB-1) as a major inflammatory marker were reduced. In the lungs, levels of HMGB-1 and interleukin 6 (IL-6) were reduced. In contrast, systemic concentrations of intestinal fatty acid binding-protein (i-FABP) as an intestinal damage marker were elevated. Furthermore, liver-type fatty acid binding-protein (L-FABP) levels were lower in the narcosis animals, and inflammatory markers were reduced in liver tissues. Anesthesia also ameliorated the inflammatory reaction in renal tissues, while plasma levels of urea and creatinine were elevated, reflecting either dehydration and/or impaired renal function.

CONCLUSION

As anesthesia with sevoflurane exhibited distinct effects in different organs, it is difficult to predict its specific impact on targets of interest in in vivo studies. Therefore, further studies are required to clarify the effects of different anesthetic drugs. Overall, the inclusion of a control group subjected to the same anesthesia protocol as the experimental groups of interest seems helpful to precisely define the inherent impact of the anesthetic when investigating immuno-pathophysiologic conditions in vivo.

Quo Vadis Anesthesiologist? The Value Proposition of Future Anesthesiologists Lies in Preserving or Restoring Presurgical Health after Surgical Insult

This Special Issue of the Journal of Clinical Medicine is devoted to anesthesia and perioperative care [...].

Sevoflurane protects the liver from ischemia-reperfusion injury by regulating Nrf2/HO-1 pathway

We aimed to investigate the role and mechanism of sevoflurane (SEV) preconditioning in liver ischemia-reperfusion (I/R) injury. In vivo, rats were randomly divided into Sham group, I/R rat model group, I/R + SEV group and SEV group. In vitro, hypoxia-reoxygenation (H/R) cell model were established. Hematoxylin-Eosin (H&E) and TUNEL assay were used to evaluate the degree of tissue damage and detect apoptosis in rats, respectively. HO-1, nuclear Nrf2 and cytosolic Nrf2 expressions were detected by immunohistochemical staining, Western blot analysis and quantitative real-time PCR (qRT-PCR), respectively. Contents of Lactate dehydrogenase (LDH), malondialdehyde (MDA), and reactive oxygen species (ROS) were determined by corresponding kits. Inflammatory factor levels, cell viability, apoptosis were detected by enzyme-linked immunosorbent assay (ELISA), MTT assay, and flow cytometry, respectively.In the I/R group, liver damage was severe, apoptosis-positive cells were increased, HO-1 and nuclear Nrf2 expressions were increased, and cytosolic Nrf2 expression was decreased. After SEV pretreatment, the degree of liver injury and apoptosis in rats were significantly reduced, HO-1 and nuclear Nrf2 expressions were increased significantly, and cytosolic Nrf2 expression was decreased. 4% SEV had the best mitigating effect on H/R-induced liver cell damage, as evidenced by reduced contents of LDH and MDA, decreased inflammatory factors, a lowered apoptosis rate, inhibited ROS production, effectively promoted Nrf2 nucleation, and activated Nrf/HO-1 pathway. ML385 pretreatment significantly inhibited the effect of SEV on hepatocytes.Sevoflurane protects the liver from ischemia-reperfusion injury by regulating the Nrf2/HO-1 pathway.

Sevoflurane Postconditioning Attenuates Hepatic Ischemia-Reperfusion Injury by Limiting HMGB1/TLR4/NF-κB Pathway via Modulating microRNA-142 in vivo and in vitro

Preconditioning of sevoflurane (Sevo) has been demonstrated to protect the liver from ischemia/reperfusion (I/R) injury. However, it is unknown whether it has hepatoprotective when given at the onset of reperfusion (postconditioning), a protocol with more clinical impact. The present study aimed to explore the hepatoprotective effects of Sevo postconditioning against hepatic IR injury in vivo and in vitro and the possible mechanisms. Using a mouse model of hepatic I/R, Sevo postconditioning significantly improved hepatic injury after reperfusion, as demonstrated by reduced AST, ALT, and LDH serum levels and reduced histologic damage in liver tissues. Furthermore, Sevo postconditioning could suppress the apoptosis, inhibit oxidative stress and inflammatory response in liver tissue of HIRI mice, as well as improve the survival rate of HIRI mice. Through analyzing GSE72314 from the gene expression omnibus (GEO) database, it was demonstrated that microRNA (miR)-142 is downregulated by HIRI, which was reversed by Sevo treatment. Further investigation showed that agomiR-142 injection could enhance the hepatoprotective effects of Sevo postconditioning on I/R injury, while antagomiR-142 reversed these effects in mice. Notably, high mobility group box 1 (HMGB1), an important inflammatory factor, was directly targeted by miR-142 in hepatic cells, and we further found that Sevo could inhibit the expression of HMGB1 through up-regulating miR-142 expression in HIRI mice model. In addition, we found that I/R injury induced the activation of TLR4/NF-κB inflammatory pathway was partially suppressed by Sevo postconditioning, and miR-142 mediated the regulatory role of Sevo postconditioning. In line with the in vivo results, Sevo treatment improved the cell viability, inhibited cell apoptosis, oxidative stress and inflammatory response in vitro HIRI model, while these effects were reversed by antagomiR-142 transfection. Collectively, our findings demonstrated that Sevo postconditioning counteracts the downregulation of miR-142 provoked by I/R, in turn decreased the expression of HMGB1, blocking TLR4/NF-κB pathway activation, thus improving hepatic I/R injury. Our data suggest that Sevo may be a valuable alternative anaesthetic agent in liver transplantation and major liver surgeries.

Impact of Anesthetic Agents on Endothelial Glycocalyx Injury during Total Knee Arthroplasty: Desflurane- vs. Propofol-Based Anesthesia-A Prospective Randomized Controlled Trial

Background

Ischemia-reperfusion injury and inflammation after tourniquet deflation in total knee arthroplasty are known to be associated with endothelial glycocalyx (EG) injury. This study is aimed at comparing EG injury between desflurane- and propofol-based anesthesia in patients undergoing total knee arthroplasty.

Materials and Methods

Patients were allocated to the desflurane group or propofol group. The opioid remifentanil was administered intraoperatively in both groups. Blood samples were obtained from the arterial line preoperatively, immediately before and 5 min after tourniquet deflation, and at 1, 6, and 24 h, postoperatively. Serum syndecan-1, cytokines (interleukin-1β, 6, 10, and tumour necrosis factor-α), and other laboratory values were investigated.

Results

Eighty patients were included in the final analysis. The change in syndecan-1 did not significantly differ between the desflurane and propofol groups (peak median level of syndecan-1; 754.5 pg/ml vs. 780.3 pg/ml, respectively, P = 0.512). Laboratory values (serum cytokines, creatinine phosphokinase, lactate dehydrogenase, and lactate levels) were also similar between the two groups. Pulmonary oxygenation was briefly improved after tourniquet deflation in the desflurane group but was similar between the two groups begging at 1 h, postoperatively.

Conclusions

The effect of desflurane was not superior to that of propofol in protecting the EG from ischemia-reperfusion injury during total knee arthroplasty. This trial is registered with Trial Registry Number NCT02756715 (http://clinicaltrials.gov).

Sedating Mechanically Ventilated COVID-19 Patients with Volatile Anesthetics: Insights on the Last-Minute Potential Weapons

Coronavirus Disease 2019 (COVID-19) has spread globally with the number of cases exceeding seventy million. Although trials on potential treatments of COVID-19 Acute Respiratory Distress Syndrome (ARDS) are promising, the introduction of an effective therapeutic intervention seems elusive. In this review, we explored the potential therapeutic role of volatile anesthetics during mechanical ventilation in the late stages of the disease. COVID-19 is thought to hit the human body via five major mechanisms: direct viral damage, immune overactivation, capillary thrombosis, loss of alveolar capillary membrane integrity, and decreased tissue oxygenation. The overproduction of pro-inflammatory cytokines will eventually lead to the accumulation of inflammatory cells in the lungs, which will lead to ARDS requiring mechanical ventilation. Respiratory failure resulting from ARDS is thought to be the most common cause of death in COVID-19. The literature suggests that these effects could be directly countered by using volatile anesthetics for sedation. These agents possess multiple properties that affect viral replication, immunity, and coagulation. They also have proven benefits at the molecular, cellular, and tissue levels. Based on the comprehensive understanding of the literature, short-term sedation with volatile anesthetics may be beneficial in severe stages of COVID-19 ARDS and trials to study their effects should be encouraged.

Sevoflurane attenuates cardiomyocyte apoptosis by mediating the miR-219a/AIM2/TLR4/MyD88 axis in myocardial ischemia/reperfusion injury in mice

Myocardial infarction (MI) is a vital cause of death and disability globally. The primary treatment for diminishing acute myocardial ischemic injury is myocardial reperfusion, which may induce cardiomyocyte death. Our aim is to unravel the mechanism of sevoflurane (Sev) in microRNA-219a (miR-219a)-mediated regulation of absent in melanoma 2 (AIM2) and TLR4/MyD88 pathway during myocardial ischemia/reperfusion (I/R). The area of MI and apoptosis of cardiomyocytes of the developed mouse model were evaluated by TTC staining and TUNEL, respectively. After the determination of miR-219a as our target using microarray analysis, miR-219a atagomiR was used to treat the mouse model. The luciferase assay verified whether miR-219a targeted AIM2, and the miR-219a and AIM2 expression in myocardial tissues was detected by RT-qPCR and Western blot. miR-219a was significantly increased in myocardial tissues from mice treated with Sev, and the area of MI and cardiomyocyte apoptosis were decreased as a consequence. The miR-219a inhibitor reversed the action of Sev. Moreover, overexpression of AIM2 or induction of the TLR4 pathway aggravated myocardial I/R injury alleviated by miR-219a. All in all, the treatment of Sev upregulated miR-219a expression, which blocked the TLR4 pathway by targeting AIM2 and attenuated cardiomyocyte apoptosis in myocardial I/R mouse model.

Sevoflurane Protects Hepatocytes From Ischemic Injury by Reducing Reactive Oxygen Species Signaling of Hepatic Stellate Cells: Translational Findings Based on a Clinical Trial

BACKGROUND

Randomized controlled trials (RCTs) data demonstrate that sevoflurane postconditioning improves clinical outcomes of liver resection with inflow occlusion, presumably due to hepatocyte protection from ischemic injury. However, mechanisms remain unclear. This study examines liver biopsy samples obtained in an RCT of sevoflurane postconditioning to test the hypothesis that sevoflurane attenuates hepatocyte apoptosis.

METHODS

Messenger ribonucleic acid (mRNA) of pro- and antiapoptotic regulators Bax and B-cell lymphoma 2 (Bcl2) was examined in hepatic biopsies obtained during the RCT. Hepatic stellate cells (HSCs) and hepatocytes were exposed to hypoxia/reoxygenation (H/R) in vitro to evaluate the effect of sevoflurane postconditioning on apoptosis. The role of HSC as a potential apoptosis trigger in hepatocytes through the production of reactive oxygen species induced by H/R was explored by transferring supernatants from H/R-exposed HSC to hepatocytes as target cells.

RESULTS

In patients of the RCT, the Bax/Bcl2 mRNA ratio in liver tissue was markedly decreased in the sevoflurane arm (25% ± 21% reduction; P = .001). In vitro, H/R increased reactive oxygen species production in HSC by 33% ± 16% (P = .025), while it was abolished in the presence of sevoflurane (P < .001). In hepatocytes, caspase was minimally activated by H/R. However, incubation of hepatocytes with supernatants of HSC, previously exposed to H/R, increased caspase activity by 28% ± 13% (P < .001). When exposed to supernatants from HSC undergoing sevoflurane postconditioning, caspase activation in hepatocytes was reduced by 20% ± 9% (P < .001), similarly to the sevoflurane effect on the BAX/Bcl2 mRNA ratio in the liver samples.

CONCLUSIONS

The study shows that sevoflurane postconditioning affects apoptosis of hepatocytes after ischemia-reperfusion injury in patients. It also demonstrates that HSC may be the effector cells of sevoflurane protection.

Comparison of Inflammatory Markers Between the Sevoflurane and Isoflurane Anesthesia in a Rat Model of Liver Ischemia/Reperfusion Injury

BACKGROUND

Sevoflurane and isoflurane had been reported to improve ischemia/reperfusion injury (I/R) through amelioration of the inflammatory response. We aimed to explore and compare the molecular mechanisms involved in sevoflurane and isoflurane anesthesia in liver ischemia-reperfusion of rat model.

METHODS

Forty male Wistar rats were randomly divided into 4 groups: sham group, I/R group, sevoflurane group, and isoflurane group. The liver I/R injury model was established to investigate the effect of sevoflurane and isoflurane anesthesia on liver ischemia/reperfusion. The inflammatory markers and complement C3, C5a, and C6 were detected by enzyme-linked immunosorbent assay. Oxidative stress was detected by measuring the levels of malondialdehyde (MDA), superoxide dismutase (SOD), and nitric oxide (NO).

RESULTS

Our results showed that sevoflurane anesthesia significantly decreased alanine transaminase, aspartate transaminase, and lactate dehydrogenase levels compared with isoflurane and controls. Sevoflurane inhibited I/R injury induced production of tumor necrosis factor α, interleukin 1, interleukin 6, and intercellular cell adhesion molecule-1 and promoted interleukin 10 production more significantly compared with isoflurane. Reduced MDA and NO and elevated SOD release suggested that oxidative stress was attenuated by sevoflurane and isoflurane anesthesia. Both sevoflurane and isoflurane anesthesia significantly decreased plasma C3 levels compared with the I/R injury group without differences.

CONCLUSION

Sevoflurane anesthesia produced a more significant inhibitive effect on inflammatory cytokines and oxidative stress in liver I/R injury model than isoflurane, suggesting that sevoflurane is more suitable in surgery.

MicroRNA-370 protects against myocardial ischemia/reperfusion injury in mice following sevoflurane anesthetic preconditioning through PLIN5-dependent PPAR signaling pathway

Myocardial ischemia/reperfusion injury (IRI) has long been identified to be a contributor to adverse cardiovascular outcomes following myocardial ischemia, cardiac surgery or circulatory arrest. This study aims to investigate the effects of microRNA (miR-370) targeting perilipin-5 (PLIN5) in mice following sevoflurane anesthetic preconditioning (SAP). A mouse model of left ventricular myocardial IRI was established, followed by the evaluation of myocardial infarction size and cardiac function to determine the effects of SAP. The underlying regulatory mechanisms of miR-370 were analyzed in concert with the treatment of miR-370 mimic, miR-370 inhibitor, or siRNA against PLIN5 in cardiomyocytes isolated from mice with IRI. Also, cardiomyocyte proliferation, cell cycle distribution and apoptosis were evaluated following treatment. Lastly, SAP-treated I/R mice were injected with miR-370 inhibitor to verify the mechanism of SAP. The use of SAP conferred cardioprotective effects on myocardial IRI. MiR-370 was downregulated in mice that exhibited IRI, but SAP elevated the miR-370 expression. Functionally, miR-370 negatively targeted PLIN5 and activated the peroxisome proliferator activated-receptor (PPAR) signaling pathway, leading to decreased PPARγ expression but increased PPARα expression. The results also showed that elevation of miR-370 or the silencing of PLIN5 promoted cardiomyocyte proliferation. miR-370 also inhibited cardiomyocyte apoptosis as reflected by decreased caspase-3 expression and increased Bcl-2 expression. Additionally, SAP also alleviated I/R injury by inhibiting PPARγ. This study demonstrates that SAP induces miR-370 and exerts cardioprotective effects on myocardial IRI, where upregulation of miR-370 alleviates myocardial IRI via inhibiting the PLIN5-dependent PPAR signaling pathway.

Immune Modulation by Volatile Anesthetics

Volatile general anesthetics continue to be an important part of clinical anesthesia worldwide. The impact of volatile anesthetics on the immune system has been investigated at both mechanistic and clinical levels, but previous studies have returned conflicting findings due to varied protocols, experimental environments, and subject species. While many of these studies have focused on the immunosuppressive effects of volatile anesthetics, compelling evidence also exists for immunoactivation. Depending on the clinical conditions, immunosuppression and activation due to volatile anesthetics can be either detrimental or beneficial. This review provides a balanced perspective on the anesthetic modulation of innate and adaptive immune responses as well as indirect effectors of immunity. Potential mechanisms of immunomodulation by volatile anesthetics are also discussed. A clearer understanding of these issues will pave the way for clinical guidelines that better account for the impact of volatile anesthetics on the immune system, with the ultimate goal of improving perioperative management.

Mitochondrial Dysfunction and Autophagy in Hepatic Ischemia/Reperfusion Injury

Ischemia/reperfusion (I/R) injury remains a major complication of liver resection, transplantation, and hemorrhagic shock. Although the mechanisms that contribute to hepatic I/R are complex and diverse involving the interaction of cell injury in hepatocytes, immune cells, and endothelium, mitochondrial dysfunction is a cardinal event culminating in hepatic reperfusion injury. Mitochondrial autophagy, so-called mitophagy, is a key cellular process that regulates mitochondrial homeostasis and eliminates damaged mitochondria in a timely manner. Growing evidence accumulates that I/R injury is attributed to defective mitophagy. This review aims to summarize the current understanding of autophagy and its role in hepatic I/R injury and highlight the various therapeutic approaches that have been studied to ameliorate injury.