title: Autophagy activation prevents sevoflurane-induced neurotoxicity in H4 human neuroglioma cells.
abstract: OBJECTIVE
  The inhaled anesthetic sevoflurane may induce cognitive impairment in both animals and humans. Previous study has shown that sevoflurane triggers ER stress and may lead to apoptosis in rat hippocampal neurons. In this study, we examined whether sevoflurane caused autophagy and its contributions to sevoflurane induced neuronal cell injury.
  
  
  METHODS
  H4 human neuroglioma cells were exposed to 4.1% sevoflurane for 6 h. Cell viability and apoptosis ratio were assessed using a CCK8 kit and flow cytometry, respectively. Autophagosomes in the cells were detected using GFP-LC3 plasmid transfection or transmission electronic microscopy. The expression of LC3B, p62/SQSTM, C/EBP homologous protein (CHOP) and glucose-related protein 78 (GRP78) was assessed with Western blotting.
  
  
  RESULTS
  Sevoflurane treatment induced apoptosis and markedly increased the LC3-II level and GFP-LC3 puncta number, decreased p62 expression in H4 cells. Activation of autophagy by rapamycin (1 μmol/L) significantly reduced sevoflurane-induced apoptosis and increased cell viability, whereas inhibition of autophagy with 3-MA (5 mmol/L) caused the opposite effects. Furthermore, sevoflurane treatment markedly increased the expression of CHOP and GRP78, two hallmark proteins of ER stress. Inhibition of ER stress by 4-phenylbutyrate (500 μmol/L) abrogated sevoflurane-induced autophagy and apoptosis, and improved the viability. Moreover, sevoflurane-stimulated expression of CHOP and GRP78 was inhibited by rapamycin, but further enhanced by 3-MA.
  
  
  CONCLUSIONS
  Sevoflurane treatment induces ER stress and activates autophagy, which antagonizes sevoflurane-induced apoptosis in H4 human neuroglioma cells. The results suggest that autophagy may be a potential therapeutic target in preventing sevoflurane-induced neurotoxicity.
authors.affiliation: Department of Anesthesiology, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou 310020, China.
authors.forename: You-Fa
authors.initials: YF
authors.lastname: Zhou
authors.affiliation: Department of Anesthesiology, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou 310020, China.|Department of Anesthesiology, the Second Hospital of Jiaxing, Jiaxing 314000, China.
authors.forename: Qing-Xia
authors.initials: QX
authors.lastname: Wang
authors.affiliation: Department of Anesthesiology, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou 310020, China.
authors.forename: Hai-Yan
authors.initials: HY
authors.lastname: Zhou
authors.affiliation: Department of Anesthesiology, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou 310020, China.
authors.forename: Gang
authors.initials: G
authors.lastname: Chen
mesh_terms: D018685:Anesthetics, Inhalation / Q000633:toxicity*; D017209:Apoptosis / Q000187:drug effects; D001343:Autophagy / Q000187:drug effects*; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D000091342:Endoplasmic Reticulum Chaperone BiP; D059865:Endoplasmic Reticulum Stress / Q000187:drug effects; D006801:Humans; D008738:Methyl Ethers / Q000633:toxicity*; D000077149:Sevoflurane; D020123:Sirolimus / Q000494:pharmacology
chemical_list: D018685:Anesthetics, Inhalation; D000091342:Endoplasmic Reticulum Chaperone BiP; C000717247:HSPA5 protein, human; D008738:Methyl Ethers; D000077149:Sevoflurane; D020123:Sirolimus