Permanent URL to this publication: http://dx.doi.org/10.5167/uzh-19828
Keel, M; Mica, L; Stover, J; Stocker, R; Trentz, O; Härter, L (2005). Thiopental-induced apoptosis in lymphocytes is independent of CD95 activation. Anesthesiology, 103(3):576-584.
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BACKGROUND: Barbiturate coma is used in patients with traumatic brain injury whenever increases in intracranial pressure remain unresponsive to less aggressive therapeutic regimens. However, barbiturate-mediated neuroprotection correlates with lymphopenia, which increases the risk of infection. The mechanisms by which barbiturates lead to lymphopenia remain to be determined. METHODS: Freshly isolated human lymphocytes and Jurkat cells were incubated with the barbiturate thiopental for 24 and 48 h. Apoptosis was measured by fluorescein isothiocyanate-Annexin and propidium iodide staining, rhodamine 123 staining, and the terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling method. Caspase-3 activity was detected by Western blot and substrate cleavage assay. RESULTS: Thiopental dose-dependently (5-500 microg/ml) increased apoptosis in Jurkat cells from basal levels (4.4 +/- 1.9%) to 29.7 +/- 2.8% after 24 h and 39.7 +/- 3.2% after 48 h, whereas in lymphocytes, thiopental-induced necrosis was observed. Parallel to apoptosis, thiopental dose-dependently increased caspase-3-like activity in Jurkat cells. However, the pan-caspase inhibitor z-VAD-fmk (20 microm) only marginally reduced thiopental-induced (250 microg/ml) apoptosis in Jurkat cells (20.2 +/- 2.5 to 17.2 +/- 2.5%) and necrosis in lymphocytes (39.2 +/- 7.5 to 30.7 +/- 14%). In contrast, anti-CD95-induced apoptosis in Jurkat cells (27.0 +/- 2.0%) was completely blocked by z-VAD-fmk (8.1 +/- 1.8%). Neither expression of CD95 on Jurkat cells nor pretreatment with a neutralizing anti-CD95 antibody influenced thiopental-induced apoptosis, indicating that thiopental induces apoptosis independently of the CD95 system. The nuclear factor kappaB inhibitor gliotoxin accelerated both thiopental- and CD95-mediated apoptosis, indicating a mutual control mechanism of thiopental- and CD95-induced apoptosis. CONCLUSIONS: Thiopental directly induces cell death in lymphocytes and Jurkat cells by a CD95-independent mechanism.
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|Item Type:||Journal Article, refereed, original work|
|Communities & Collections:||04 Faculty of Medicine > University Hospital Zurich > Division of Surgical Intensive Care Medicine|
|DDC:||610 Medicine & health|
|Deposited On:||16 Sep 2009 12:17|
|Last Modified:||27 Nov 2013 17:11|
|Publisher:||Lippincott Wiliams & Wilkins|
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