Propofol but not sevoflurane prevents mitochondrial dysfunction and oxidative stress by limiting HIF-1α activation in hepatic ischemia/reperfusion injury

Sevoflurane protects against hepatic ischemia/reperfusion injury by modulating microRNA-200c regulation in mice

This present study was aimed to investigate the molecular mechanisms involved in sevoflurane protection of hepatic ischemia-reperfusion (I/R) injury. Firstly, we investigated the protective effects of sevoflurane against hepatic I/R injury. Biochemical analysis results showed that sevoflurane preconditioning significantly protected against hepatic I/R injury by reducing liver enzymes and improving antioxidant defense markers. We also found that sevoflurane attenuates I/R-induced hepatic cell death, by TUNEL staining, DNA fragmentation ELISA and PARP activity determination. Next, In order to find the molecular mechanism of sevoflurane preconditioning in hepatic I/R injury, we poured our attention to microRNAs regulation. We focused on miR-200c, one of microRNAs which screened from the gene expression omnibus (GEO). Furthermore, a hydrogen peroxide (H₂O₂)-induced oxidative stress apoptosis model was also established to mimic hepatic I/R injury, the effects of MiR-200c was investigated. We observed that MiR-200c inhibition decreased the H₂O₂-induced apoptosis of hepatic AML-12 cells. And also, ZEB1 is found as a target gene of miR-200c and is involved in H₂O₂-induced apoptosis. On the other hand, the in vivo model was established to examine whether sevoflurane protect against hepatic IR injury by downregulating MiR-200c. Together with the biochemical tests and apoptosis detection, results showed that over-expression of miR-200c significantly inhibited the protect effect of sevoflurane in Hepatic IR injury. Summarizing, sevoflurane preconditioning seems to ameliorate hepatic I/R injury in mice, mediated by mechanisms that include microRNA 200c down regulation. However, further more studies need to be carried out to verify this point.

[Effect of propofol on apoptosis of PC12 cells under hypoxic condition and the mechanism]

OBJECTIVE

To investigate the mechanism by which propofol exposure causes PC12 cell apoptosis under hypoxic conditions.

METHODS

PC12 cells were exposed to room air, 35% oxygen, or 5% oxygen (hypoxia) for 24 h in the presence of either 10 µmol/L lipid emulsion or 10 µmol/L propofol. After the treatments, the cell apoptosis was measured by flow ceytometry, and the level of reactive oxygen species (ROS) and the activity of superoxide dismutase (SOD) were evaluated.

RESULTS

In room air, PC12 cells treated with propofol showed increased apoptosis rate and ROS production as compared with the cells treated with the lipid emulsion; propofol treatment of the cells exposed to 35% oxygen showed obvious enhancement of the apoptosis rate, ROS production and SOD activity. Under the hypoxic condition, propofol treatment even further increased the apoptosis rate, ROS production and SOD activity. Lipid emulsion caused no such changes in cells exposed to room air, 35% oxygen or 5% oxygen.

CONCLUSION

Under hypoxic conditions, propofol can cause apoptosis in PC12 cells by inducing oxidative stress injury.