title: Anesthetic propofol causes glycogen synthase kinase-3β-regulated lysosomal/mitochondrial apoptosis in macrophages.
abstract: BACKGROUND
  Overdose propofol treatment with a prolong time causes injury to multiple cell types; however, its molecular mechanisms remain unclear. Activation of glycogen synthase kinase (GSK)-3β is proapoptotic under death stimuli. The authors therefore hypothesize that propofol overdose induces macrophage apoptosis through GSK-3β.
  
  
  METHODS
  Phagocytic analysis by uptake of Staphylococcus aureus showed the effects of propofol overdose on murine macrophages RAW264.7 and BV2 and primary human neutrophils in vitro. The authors further investigated cell apoptosis in vitro and in vivo, lysosomal membrane permeabilization, and the loss of mitochondrial transmembrane potential (MTP) by propidium iodide, annexin V, acridine orange, and rhodamine 123 staining, respectively. Protein analysis identified activation of apoptotic signals, and pharmacologic inhibition and genetic knockdown using lentiviral-based short hairpin RNA were further used to clarify their roles.
  
  
  RESULTS
  A high dose of propofol caused phagocytic inhibition and apoptosis in vitro for 24 h (25 μg/ml, in triplicate) and in vivo for 6 h (10 mg/kg/h, n = 5 for each group). Propofol induced lysosomal membrane permeabilization and MTP loss while stabilizing MTP and inhibiting caspase protected cells from mitochondrial apoptosis. Lysosomal cathepsin B was required for propofol-induced lysosomal membrane permeabilization, MTP loss, and apoptosis. Propofol decreased antiapoptotic Bcl-2 family proteins and then caused proapoptotic Bcl-2-associated X protein (Bax) activation. Propofol-activated GSK-3β and inhibiting GSK-3β prevented Mcl-1 destabilization, MTP loss, and lysosomal/mitochondrial apoptosis. Forced expression of Mcl-1 prevented the apoptotic effects of propofol. Decreased Akt was important for GSK-3β activation caused by propofol.
  
  
  CONCLUSIONS
  These results suggest an essential role of GSK-3β in propofol-induced lysosomal/mitochondrial apoptosis.
authors.affiliation: Department of Anesthesiology, Chi Mei Medical Center, Tainan, Taiwan.
authors.forename: Chung-Hsi
authors.initials: CH
authors.lastname: Hsing
authors.forename: Yu-Hong
authors.initials: YH
authors.lastname: Chen
authors.forename: Chia-Ling
authors.initials: CL
authors.lastname: Chen
authors.forename: Wei-Ching
authors.initials: WC
authors.lastname: Huang
authors.forename: Ming-Chung
authors.initials: MC
authors.lastname: Lin
authors.forename: Po-Chun
authors.initials: PC
authors.lastname: Tseng
authors.forename: Chi-Yun
authors.initials: CY
authors.lastname: Wang
authors.forename: Cheng-Chieh
authors.initials: CC
authors.lastname: Tsai
authors.forename: Pui-Ching
authors.initials: PC
authors.lastname: Choi
authors.forename: Chiou-Feng
authors.initials: CF
authors.lastname: Lin
mesh_terms: D000777:Anesthetics / Q000494:pharmacology; D000818:Animals; D017209:Apoptosis / Q000187:drug effects* / Q000502:physiology*; D002460:Cell Line; D038362:Glycogen Synthase Kinase 3 / Q000502:physiology*; D000071679:Glycogen Synthase Kinase 3 beta; D056945:Hep G2 Cells; D006801:Humans; D008247:Lysosomes / Q000187:drug effects* / Q000378:metabolism; D008264:Macrophages / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008928:Mitochondria / Q000187:drug effects* / Q000201:enzymology / Q000502:physiology; D015742:Propofol / Q000494:pharmacology*
chemical_list: D000777:Anesthetics; C000605506:GSK3B protein, human; D000071679:Glycogen Synthase Kinase 3 beta; C000605507:Gsk3b protein, mouse; D038362:Glycogen Synthase Kinase 3; D015742:Propofol