Ameliorative effect of sevoflurane on endoplasmic reticulum stress mediates cardioprotection against ischemia-reperfusion injury 1

Efficacy of Sevoflurane and Propofol Anesthesia on Perioperative Adverse Cardiovascular Events and Hemodynamics in Elderly Patients With Diabetes

PURPOSE

This study was undertaken to compare the effects of sevoflurane and propofol anesthesia on perioperative hemodynamics and perioperative adverse cardiovascular events (PACE) in elderly patients with diabetes undergoing general anesthesia for noncardiac surgery.

METHODS

According to the random number table (n = 40), 80 patients with diabetes undergoing noncardiac general anesthesia were divided into a control group and an observation group. In the control group, the patients were given propofol 4 to 6 mg/(kg·h), continuously pumped to maintain anesthesia. In the observation group, the patients were given maintained concentration of sevoflurane for 1 to 1.5 minimum alveolar concentration (MAC) for continuous inhalation, while remifentanil with volume fraction of 0.05 to 1 µg/(kg·min) was given for continuous pumping in both groups. The heart rate (HR) and mean arterial pressure (MAP) of the patients were recorded, and the serum creatine kinase-MB (CK-MB) and cardiac troponin I (cTnI) contents before anesthesia (T0), immediately after surgery (T3), and 24 hours later (T4) as well as the blood glucose levels at T0 and T3 were compared between the two groups. The occurrence of PACE in the two groups was compared during the perioperative period.

FINDINGS

The HR and MAP 5 minutes after intubation (T1), 1 hour after skin incision (T2), and at T3 in the two groups were significantly lower than those of T0 (P < 0.05), whereas the MAP and HR of T1, T2, and T3 in the observation group were significantly higher than those of the control group (P < 0.05). The T3 blood glucose levels were significantly higher in the two groups than that in T0 (P < 0.05), and the T3 blood glucose levels in the observation group were significantly lower than that in the control group (P < 0.05). CK-MB and cTnI in the two groups were significantly higher at T3 and T4 than T0 (P < 0.05), whereas CK-MB and cTnI in the observation group were significantly lower than in the control group at T3 and T4 (P < 0.05). The incidence of hypotension and PACE was significantly lower in the observation group than in the control group (P < 0.05).

IMPLICATIONS

Compared with propofol IV general anesthesia, sevoflurane inhalation anesthesia can improve perioperative hemodynamics stability and reduce the incidence of PACE in elderly patients with diabetes undergoing noncardiac surgery.

The Protective Effect of Sevoflurane Conditionings Against Myocardial Ischemia/Reperfusion Injury: A Systematic Review and Meta-Analysis of Preclinical Trials in in-vivo Models

Objective

Myocardial ischemia/reperfusion injury (IRI) is a common and serious complication in clinical practice. Sevoflurane conditionings have been identified to provide a protection against myocardial IRI in animal experiments, but their true clinical benefits remain controversial. Here, we aimed to analyze the preclinical evidences obtained in animal models of myocardial IRI and explore the possible reasons for controversial clinical benefits.

Methods

Our primary outcome was the difference in mean infarct size between the sevoflurane and control groups in animal models of myocardial IRI. After searching the databases of PubMed, Embase, Web of Science, and the Cochrane Library, a systematic review retrieved 37 eligible studies, from which 28 studies controlled comparisons of sevoflurane preconditioning (SPreC) and 40 studies controlled comparisons of sevoflurane postconditioning (SPostC) that were made in a pooled random-effects meta-analysis. In total, this analysis included data from 313 control animals and 536 animals subject to sevoflurane conditionings.

Results

Pooled estimates for primary outcome demonstrated that sevoflurane could significantly reduce the infarct size after myocardial IRI whether preconditioning [weighted mean difference (WMD): −18.56, 95% CI: −23.27 to −13.85, P < 0.01; I² = 94.1%, P < 0.01] or postconditioning (WMD: −18.35, 95% CI: −20.88 to −15.83, P < 0.01; I² = 90.5%, P < 0.01) was performed. Interestingly, there was significant heterogeneity in effect size that could not be explained by any of the prespecified variables by meta-regression and stratified analysis. However, sensitivity analysis still identified the cardioprotective benefits of sevoflurane conditionings with robust results.

Conclusion

Sevoflurane conditionings can significantly reduce infarct size in in-vivo models of myocardial IRI. Given the fact that there is a lack of consistency in the quality and design of included studies, more well-performed in-vivo studies with the detailed characterization of sevoflurane protocols, especially studies in larger animals regarding cardioprotection effects of sevoflurane, are still required.

Sevoflurane Induces Ferroptosis of Glioma Cells Through Activating the ATF4-CHAC1 Pathway

Objective

To clarify the function and mechanisms of sevoflurane (Sev) on ferroptosis in glioma cells.

Methods

Different concentrations of Sev were used to treat glioma cells U87 and U251. Ferroptosis inducer Erastin was used to incubate glioma cells combined with Sev and ATF4 siRNA transfection treatment. CCK-8 assay and colorimetric assay were performed to analyze cell viability and Fe+ concentration, respectively. The releases of reactive oxygen species (ROS) were determined by flow cytometry analysis. Transcriptional sequencing was used to screen the differential genes affected by Sev in U251 cells. The mRNA and protein expression of ferroptosis-associated genes was detected by qRT-PCR and Western blotting.

Results

Sev could suppress cell viability, increase ROS levels and Fe+ concentration, downregulate the protein expression levels of GPX4, and upregulate transferrin, ferritin, and Beclin-1 in a dose-dependent manner in U87 and U251 cells. The expression of ferroptosis and mitophagy-related gene activating transcription factor 4 (ATF4) was identified to be enhanced by Sev analyzed by transcriptional sequencing. ChaC glutathione-specific gamma-glutamylcyclotransferase 1 (CHAC1), which is involved in ferroptosis, is a downstream gene of ATF4. Inhibition of ATF4 could interrupt the expression of CHAC1 induced by Sev in U87 and U251 cells. Ferroptosis inducer Erastin treatment obviously inhibited the cell viability, elevated the Fe2+ concentration, and promoted ROS generation in U87 and U251 cells. The protein level of ATF4 and CHAC1 was increased in Erastin-treated U87 and U251 cells. Moreover, the interruption of Sev-induced ferroptosis and CHAC1 activating induced by ATF4 suppression could be reversed by Erastin.

Conclusions

In summary, this study suggested that Sev exposure-induced ferroptosis by the ATF4-CHAC1 pathway in glioma cells.

Upregulated microRNA-210-3p improves sevoflurane-induced protective effect on ventricular remodeling in rats with myocardial infarction by inhibiting ADCY9

Myocardial infarction (MI) is a significant cause of death and disability, and sevoflurane (sevo) can protect myocardium in clinic. We aim to assess the effects of miR-210-3p on MI rats undergoing sevo treatment with the involvement of adenylyl cyclase type 9 (ADCY9). Rat MI models were constructed by ligation of the left anterior descending, and the modeled rats were respectively treated with sevo, miR-210-3p agomir, antagomir, or overexpressed ADCY9. Then, miR-210-3p and ADCY9 expression, cardiac function, myocardial injury and fibrosis, and cardiomyocyte apoptosis in rats were evaluated. Target relation between miR-210-3p and ADCY9 was detected. miR-210-3p was downregulated while ADCY9 was upregulated in MI rats. Sevo was able to promote cardiac function and attenuate myocardial injury and fibrosis, as well as cardiomyocyte apoptosis in MI rats. These effects of sevo were strengthened by miR-210-3p elevation but abolished by miR-210-3p inhibition in MI rats. The role of elevated miR-210-3p in MI rats was reversed by overexpression of ADCY9. Upregulated miR-210-3p improves sevo-induced protective effect on ventricular remodeling in rats with MI through inhibiting ADCY9.

MicroRNA-203-mediated inhibition of doublecortin underpins cardioprotection conferred by sevoflurane in rats after myocardial ischaemia-reperfusion injury

Myocardial ischaemia‐reperfusion (I/R) injury is a serious illness with high morbidity and mortality. Mounting evidence indicates the utility of sevoflurane (SEV) in the treatment of myocardial I/R injury. This study aimed to explore the molecular mechanisms underlying the protective action of SEV against myocardial I/R injury. A rat model of myocardial I/R injury was established, and I/R rats were treated with different concentrations of SEV. MicroRNA‐203 (miR‐203) and doublecortin (DCX) expression levels were determined using reverse transcription‐quantitative polymerase chain reaction. Putative target relationship between miR‐203 and DCX was explored using dual‐luciferase reporter gene assay and RNA‐binding protein immunoprecipitation assay. Ischaemia‐reperfusion rats were treated with SEV, miR‐203 antagomir or sh‐DCX, followed by determination of oxidative stress‐ and inflammation‐related factor levels using nitrite and enzyme‐linked immunosorbent assays, and that of apoptosis‐related factors using Western blot analysis. The apoptotic rate of myocardial tissues was determined using TdT‐mediated dUTP‐biotin nick end labeling (TUNEL) staining, and the infract area was evaluated using triphenyltetrazolium chloride staining. The results showed miR‐203 was poorly expressed and DCX was highly expressed in myocardial tissues of I/R rats. Sevoflurane was found to elevate miR‐203, and miR‐203, in turn, could target and reduce DCX expression. Sevoflurane, miR‐203 overexpression or DCX silencing resulted in declined oxidative stress, inflammation, apoptosis and infarct area, ultimately alleviating myocardial I/R injury. Collectively, these findings showed that SEV‐activated miR‐203 exhibited suppressive effects on myocardial I/R injury in rats and highlighted the SEV/miR‐203/DCX axis as a promising therapeutic target for myocardial I/R injury management.

Up-regulation of PERK/Nrf2/HO-1 axis protects myocardial tissues of mice from damage triggered by ischemia-reperfusion through ameliorating endoplasmic reticulum stress

Background

Ischemia-reperfusion (I/R) injury, which leads to additionally cardiac tissue damage, is a severe adverse effect of reperfusion therapeutics used for the treatment of acute myocardial infarction. Agents capable of alleviating I/R-induced myocardial injury are urgently needed. In this study, we investigated whether up-regulation of PERK/Nrf2/HO-1 axis provided protective roles for murine myocardium suffering I/R intervention.

Methods

The in vivo I/R model was formed by ligation of the left anterior descending (LAD) coronary artery of C57BL/6J mice. All animals were assigned into the following groups at random: sham, I/R, rAAV9-PERK + I/R, rAAV9-Nrf2 + I/R, rAAV9-HO-1 + I/R, siRNA-HO-1 + rAAV9-PERK + I/R. The ligation of LAD was released after 30 min of ischemia, which was followed by reperfusion of LAD for 4 h. Then the cardiac tissues and blood serum were collected. TUNEL staining, ELISA assay, TTC staining, Western blotting and real-time PCR were used to determine I/R injury-related indicators.

Results

Our results showed that I/R administration triggered cardiomyocytes apoptosis and LDH and CK-MB release, yet overexpression of PERK decreased cellular apoptosis index in the cardiac tissue and reduced levels of LDH and CK-MB in the serum. We further found that the protective actions of PERK against I/R-evoked cardiac damage might be attributed to up-regulation of Nrf2/HO-1 signaling transduction, given that overexpression of Nrf2 and HO-1 ameliorated cardiac cell apoptosis and reduced the size of infarction and ischemia in the myocardial tissue, yet gene silencing of HO-1 invalidated the beneficial roles of PERK overexpression in improving I/R-induced cardiac injury. Then, we investigated whether PERK-activated Nrf2/HO-1 cascade affected endoplasmic reticulum stress (ERS), considering the crucial roles of ERS-associated apoptosis in the development of I/R damage. Our findings indicated that up-regulation of PERK-mediated Nrf2/HO-1 pathway induced the expression reduction of GRP78, CRT, CHOP and caspase-12 both at the transcriptional and translational level.

Conclusions

We, for the first time, discovered that up-regulation of PERK/Nrf2/HO-1 axis improved I/R-induced myocardial injury via reducing ERS-related signal molecules and downstream pro-apoptotic factors.