title: Volatile anesthetics induce caspase-dependent, mitochondria-mediated apoptosis in human T lymphocytes in vitro.
abstract: BACKGROUND
  Volatile anesthetics modulate lymphocyte function during surgery, and this compromises postoperative immune competence. The current work was undertaken to examine whether volatile anesthetics induce apoptosis in human T lymphocytes and what apoptotic signaling pathway might be used.
  
  
  METHODS
  Effects of sevoflurane, isoflurane, and desflurane were studied in primary human CD3 T lymphocytes and Jurkat T cells in vitro. Apoptosis and mitochondrial membrane potential were assessed using flow cytometry after green fluorescent protein-annexin V and DiOC6-fluorochrome staining. Activity and proteolytic processing of caspase 3 was measured by cleaving of the fluorogenic effector caspase substrate Ac-DEVD-AMC and by anti-caspase-3 Western blotting. Release of mitochondrial cytochrome c was studied after cell fractionation using anti-cytochrome c Western blotting and enzyme-linked immunosorbent assays.
  
  
  RESULTS
  Sevoflurane and isoflurane induced apoptosis in human T lymphocytes in a dose-dependent manner. By contrast, desflurane did not exert any proapoptotic effects. The apoptotic signaling pathway used by sevoflurane involved disruption of the mitochondrial membrane potential and release of cytochrome c from mitochondria to the cytosol. In addition, the authors observed a proteolytic cleavage of the inactive p32 procaspase 3 to the active p17 fragment, increased caspase-3-like activity, and cleavage of the caspase-3 substrate poly-ADP-ribose-polymerase. Sevoflurane-induced apoptosis was blocked by the general caspase inhibitor Z-VAD.fmk. Death signaling was not mediated via the Fas/CD95 receptor pathway because neither anti-Fas/CD95 receptor antagonism nor FADD deficiency or caspase-8 deficiency were able to attenuate sevoflurane-mediated apoptosis.
  
  
  CONCLUSIONS
  Sevoflurane and isoflurane induce apoptosis in T lymphocytes via increased mitochondrial membrane permeability and caspase-3 activation, but independently of death receptor signaling.
authors.affiliation: Division of Experimental Anesthesiology, Institute of Molecular Medicine, University Hospital, Hugstetterstrasse 55, D-79106 Freiburg, Germany. torsten@ana1.ukl.uni-freiburg.de
authors.forename: Torsten
authors.initials: T
authors.lastname: Loop
authors.forename: David
authors.initials: D
authors.lastname: Dovi-Akue
authors.forename: Michael
authors.initials: M
authors.lastname: Frick
authors.forename: Martin
authors.initials: M
authors.lastname: Roesslein
authors.forename: Lotti
authors.initials: L
authors.lastname: Egger
authors.forename: Matjaz
authors.initials: M
authors.lastname: Humar
authors.forename: Alexander
authors.initials: A
authors.lastname: Hoetzel
authors.forename: Rene
authors.initials: R
authors.lastname: Schmidt
authors.forename: Christoph
authors.initials: C
authors.lastname: Borner
authors.forename: Heike L
authors.initials: HL
authors.lastname: Pahl
authors.forename: Klaus K
authors.initials: KK
authors.lastname: Geiger
authors.forename: Benedikt H J
authors.initials: BH
authors.lastname: Pannen
mesh_terms: D018685:Anesthetics, Inhalation / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects* / Q000502:physiology; D053148:Caspase 3; D020169:Caspases / Q000378:metabolism*; D002478:Cells, Cultured; D006801:Humans; D019169:Jurkat Cells; D008928:Mitochondria / Q000187:drug effects* / Q000201:enzymology; D013601:T-Lymphocytes / Q000187:drug effects* / Q000201:enzymology; D014835:Volatilization
chemical_list: D018685:Anesthetics, Inhalation; C505407:CASP3 protein, human; D053148:Caspase 3; D020169:Caspases