Rapid and Specific Efflux of Reduced Glutathione during Apoptosis Induced by Anti-Fas/APO-1 Antibody

doi:10.1074/jbc.271.26.15420

Rapid and Specific Efflux of Reduced Glutathione during Apoptosis Induced by Anti-Fas/APO-1 Antibody*

From the Institute of Environmental Medicine, Division of Toxicology, Karolinska Institutet, Box 210, S-171 77 Stockholm, Sweden

^§To whom correspondence should be addressed. Tel.: 46-8-7287554; Fax: 46-8-329041; E-mail: andrew.slater{at}imm.ki.se.

↵^‡ Current address: Paul Bucher Co., Schützengraben 7, 4051 Basel, Switzerland.

Abstract

Although human JURKAT T lymphocytes induced to undergo apoptosis with anti-Fas/APO-1 antibody were observed to rapidly lose reduced glutathione (GSH), increased concentrations of oxidized products were not detectable. Unexpectedly, the reduced tripeptide was instead quantitatively recovered in the incubation medium of the cells. As GSH loss was blocked by bromosulfophthalein and dibromosulfophthalein, known inhibitors of hepatocyte GSH transport, a specific export rather than nonspecific leakiness through plasma membranes is proposed to be responsible. Apoptosis was delayed when GSH-diethylesters were used to elevate intracellular GSH, although the high capacity of the activated efflux system quickly negated the benefit of this treatment. Stimulation of GSH efflux provides a novel mechanism whereby Fas/APO-1 ligation can deplete GSH. We speculate that it enhances the oxidative tonus of a responding cell without requiring an increase in the production of reactive oxygen species.

Footnotes

↵* This work was supported by fellowships from the European Science Foundation (to D. D.) and the Swiss National Science Foundation (to J. S.) and a grant from the Swedish Medical Research Council. The costs of publication of this article were defrayed in part by the payment of page charges. The article must therefore be hereby marked “advertisement” in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.
↵¹ The abbreviations used are:

ICE

interleukin 1-β-converting enzyme

ROS

reactive oxygen species

BSP

bromosulfophthalein

diBSP

dibromosulfophthalein

MTT

3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide

HPLC

high performance liquid chromatography

dansyl

5-dimethylaminonaphthalene-1-sulfonyl

DTT

dithiothreitol.
- Received December 4, 1995.
- Revision received March 21, 1996.