title: Thiopental protects human T lymphocytes from apoptosis in vitro via the expression of heat shock protein 70.
abstract: Barbiturates, which are used for the treatment of intracranial hypertension after severe head injury, have been associated with anti-inflammatory side effects. Although all barbiturates inhibit T-cell function, only thiobarbiturates markedly reduce the activation of the transcription factor nuclear factor-kappaB (NF-kappaB). Various pharmacologic inhibitors of the NF-kappaB pathway are concomitant nonthermal inducers of the heat shock response (HSR), a cellular defense system that is associated with protection of cells and organs. We hypothesize that thiopental mediates cytoprotection by inducing the HSR. Human CD3(+) T lymphocytes were incubated with thiopental, pentobarbital, etomidate, ketamine, midazolam, or propofol. Human Jurkat T cells were transfected with small interfering RNA (siRNA) targeting heat 70-kDa shock protein (hsp 70) before thiopental incubation. Apoptosis was induced by staurosporine. DNA binding activity of HSF-1 was analyzed by electrophoretic mobility shift assay; mRNA expression of hsp27, -32, -70, and -90 was analyzed by Northern blot, and protein expression of hsp70 was analyzed by Western blot and flow cytometry after fluorescein isothiocyanate (FITC)-hsp70-antibody staining. Apoptosis was assessed by flow cytometry after annexin V-FITC or annexin V-phycoerythrin staining. Activity of caspase-3 was measured by fluorogenic caspase activity assay. Thiopental induced hsp27, -70, and -90 but not hsp32 mRNA expression as well as hsp70 protein expression. Thiopental dose-dependently activated the DNA binding activity of HSF-1, whereas other substances investigated had no effect. In addition, pretreatment with thiopental significantly attenuated staurosporine-induced apoptosis and caspase-like activity. Transfection with hsp70-siRNA before thiopental treatment reduced this attenuation. Thiopental specifically and differentially induces a heat shock response, and it mediates cytoprotection via the expression of hsp70 in human T lymphocytes.
authors.affiliation: Anaesthesiologische Universitaetsklinik, Hugstetterstrasse 55, D-79106 Freiburg, Germany.
authors.forename: Martin
authors.initials: M
authors.lastname: Roesslein
authors.forename: David
authors.initials: D
authors.lastname: Schibilsky
authors.forename: Laurent
authors.initials: L
authors.lastname: Muller
authors.forename: Ulrich
authors.initials: U
authors.lastname: Goebel
authors.forename: Christian
authors.initials: C
authors.lastname: Schwer
authors.forename: Matjaz
authors.initials: M
authors.lastname: Humar
authors.forename: Rene
authors.initials: R
authors.lastname: Schmidt
authors.forename: Klaus K
authors.initials: KK
authors.lastname: Geiger
authors.forename: Heike L
authors.initials: HL
authors.lastname: Pahl
authors.forename: Benedikt H J
authors.initials: BH
authors.lastname: Pannen
authors.forename: Torsten
authors.initials: T
authors.lastname: Loop
mesh_terms: D017209:Apoptosis / Q000187:drug effects*; D017252:CD3 Complex; D005786:Gene Expression Regulation / Q000187:drug effects; D018840:HSP70 Heat-Shock Proteins / Q000032:analysis / Q000235:genetics*; D018869:Heat-Shock Response / Q000187:drug effects; D006801:Humans; D020011:Protective Agents / Q000494:pharmacology; D012333:RNA, Messenger / Q000032:analysis; D013601:T-Lymphocytes / Q000166:cytology / Q000187:drug effects*; D013874:Thiopental / Q000494:pharmacology*
chemical_list: D017252:CD3 Complex; D018840:HSP70 Heat-Shock Proteins; D020011:Protective Agents; D012333:RNA, Messenger; D013874:Thiopental