Sevoflurane preconditioning activates HGF/Met-mediated autophagy to attenuate hepatic ischemia-reperfusion injury in mice

Sevoflurane (SEV) preconditioning plays a protective effect against liver ischemia reperfusion (IR) injury, while the role of autophagy in SEV-mediated hepatoprotection and the precise mechanism is unclear. In the current study, mice were pretreated with SEV or autophagy inhibitor before liver IR injury. In vitro, primary rat hepatocytes were pretreated with SEV and then exposed to hypoxia/reoxygenation (H/R). Liver function was measured by biochemical and histopathological examinations, and markers associated with inflammation, oxidation, apoptosis and autophagy were subsequently measured. We found that SEV preconditioning dramatically reduced hepatic damage, alleviated cell inflammatory response, oxidative stress and apoptosis in mice suffering hepatic IR injury, whereas these protective effects were abolished by the autophagy inhibitor 3-MA. In addition, pretreatment with SEV markedly activated HGF/Met signaling pathway regulation. Besides, pretreatment with an hepatocyte growth factor (HGF) inhibitor or knocking down HGF expression significantly downregulated phosphorylated met (p-met) and autophagy levels, and abolished the protective effects of SEV against hepatic IR or hepatocyte H/R injury. Conversely, HGF overexpression efficiently increased the p-met and autophagy levels and strengthened the protective effects of SEV. These results indicated that sevoflurane preconditioning ameliorates hepatic IR injury by activating HGF/Met-mediated autophagy.

Sevoflurane preconditioning attenuates hypoxia/reoxygenation injury of H9c2 cardiomyocytes by activation of the HIF-1/PDK-1 pathway

Background

Sevoflurane preconditioning (SPC) can provide myocardial protective effects similar to ischemic preconditioning (IPC). However, the underlying molecular mechanism of SPC remains unclear. Studies confirm that hypoxia-inducible factor-1 (HIF-1) can transform cells from aerobic oxidation to anaerobic glycolysis by activating the switch protein pyruvate dehydrogenase kinase-1 (PDK-1), thus providing energy for the normal life activities of cells under hypoxic conditions. The purpose of this study was to investigate whether the cardioprotective effects of SPC are associated with activation of the HIF-1a/PDK-1 signal pathway.

Methods

The H9c2 cardiomyocytes hypoxia/reoxygenation model was established and treated with 2.4% sevoflurane at the end of equilibration. Lactate dehydrogenase (LDH) level, cell viability, cell apoptosis, mitochondrial membrane potential, key enzymes of glycolysis, ATP concentration of glycolysis were assessed after the intervention. Apoptosis related protein(Bcl-2, Bax), HIF-1a protein, and PDK-1 protein were assessed by western blot.

Results

Compared with the H/R group, SPC significantly increased the expression of HIF-1a, PDK-1, and Bcl-2 and reduced the protein expression of Bax, which markedly decreased the apoptosis ratio and Lactate dehydrogenase (LDH) level, increasing the cell viability, content of key enzymes of glycolysis, ATP concentration of glycolysis and stabilizing the mitochondrial membrane potential. However, the cardioprotective effects of SPC were disappeared by treatment with a HIF-1a selective inhibitor.

Conclusion

This study demonstrates that the cardioprotective effects of SPC are associated with the activation of the HIF-1a/PDK-1 signaling pathway. The mechanism may be related to increasing the content of key enzymes and ATP of glycolysis in the early stage of hypoxia.

Sevoflurane preconditioning in on-pump coronary artery bypass grafting: a meta-analysis of randomized controlled trials

PURPOSE

Sevoflurane preconditioning (SevoPreC) has been proved to prevent organ ischemia/reperfusion (I/R) injury in various animal models and preclinical studies. Clinical trials on cardioprotection by SevoPreC for adult patients undergoing coronary artery bypass graft (CABG) revealed mixed results. The aim of this meta-analysis was to evaluate the cardiac effect of SevoPreC in on-pump CABG.

METHODS

Randomized controlled trials (RCT) comparing the cardiac effect of SevoPreC (compared with control) in adult patients undergoing CABG were searched from PubMed, Embase, and the Cochrane Library (up to November 2015). The primary endpoints were postoperative troponin levels. Additional endpoints were CK-MB levels, mechanic ventilation (MV) duration, intensive care unit (ICU) stay, and hospital length of stay (LOS).

RESULTS

Six trials with eight comparisons enrolling a total of 384 study patients reporting postoperative troponin levels were identified. Compared with controls, SevoPreC decreased postoperative myocardial troponin levels [standardized mean difference (SMD) = -0.38; 95 % CI, -0.74 to -0.03; P = 0.04; I ² = 63.9 %]. However, no significant differences were observed in postoperative CK-MB levels [weighted mean difference (WMD) = -1.71; P = 0.37; I ² = 37.7 %], MV duration (WMD = -0.53; P = 0.47; I ² = 0.0 %), ICU stay (WMD = -0.91; P = 0.39; I ² = 0.9 %), and hospital LOS (WMD = 0.08; P = 0.86; I ² = 8.0 %).

CONCLUSION

Available evidence from the present systematic review and meta-analysis suggests that sevoflurane preconditioning may reduce troponin levels in on-pump CABG. Future high-quality, large-scale clinical trials should focus on the early and long-term clinical effect of SevoPreC in on-pump CABG.

Sevoflurane preconditioning improving cerebral focal ischemia-reperfusion damage in a rat model via PI3K/Akt signaling pathway

In this study, we aimed to assess the neuroprotective effect of sevoflurane preconditioning in a cerebral focal ischemia-reperfusion rat model. Sixty Sprague Dawley rats were divided into six groups: sham operated group, cerebral focal ischemia-reperfusion (CIR) group, CIR+sevoflurane preconditioning (SP) (2%) group, CIR+sevoflurane preconditioning (2.5%) group, CIR+sevoflurane preconditioning (3%) group, and CIR+sevoflurane preconditioning (3.5%) group. All subjects were euthanized 2days post-surgery and their hippocampus tissues were removed. Tissue malondialdehyde (MDA), superoxide dismutase (SOD), glutathione (GSH) and glutathione peroxidase (GSH-Px) levels were measured and hippocampus tissue samples were examined histopathologically. Results showed that significant difference in antioxidant, immunity indexes, and apoptosis-related protein expression was detected in hippocampus tissue between sham-operated control and CIR groups. Sevoflurane preconditioning significantly dose-dependently reduced MDA, IL-1β, IL-6, IL-10 and TNF-α levels and enhanced antioxidant enzyme activities in hippocampus tissue of CIR+SP groups compared to CIR group. In addition, sevoflurane preconditioning significantly dose-dependently upregulated PI3K, p-Akt and Bcl-2 levels and downregulated caspase-3 and Bax levels in hippocampus tissue of CIR+SP groups compared to CIR group. It can be concluded that sevoflurane preconditioning demonstrates a strong and ameliorative effect on cerebral I/R damage in rats. The neuroprotective mechanisms of sevoflurane preconditioning are associated with its properties of anti-apoptosis and anti-oxidation as well as regulation of PI3K and p-Akt signal activation.