Ceramide induces a loss in cytosolic peroxide levels in mononuclear cells


Ceramide (a sphingolipid) and reactive oxygen species are each partly responsible for intracellular signal transduction in response to a variety of agents. It has been reported that ceramide and reactive oxygen species are intimately linked and show reciprocal regulation [Liu, Andreieu-Abadie, Levade, Zhang, Obeid and Hannun (1998) J. Biol. Chem. 273, 11313-11320]. Utilizing synthetic, short-chain ceramide to mimic the cellular responses to fluctuations in natural endogenous ceramide formation or using stimulation of CD95 to induce ceramide formation, we found that the principal redox-altering property of ceramide is to lower the [peroxide]cyt (cytosolic peroxide concentration). Apoptosis of Jurkat T-cells, primary resting and phytohaemagglutinin-activated human peripheral blood T-lymphocytes was preceded by a loss in [peroxide]cyt, as measured by the peroxide-sensitive probe 2′,7′-dichlorofluorescein diacetate (also reflected in a lower rate of superoxide dismutase-inhibitable cytochrome c reduction), and this was not associated with a loss of membrane integrity. Where growth arrest of U937 monocytes was observed without a loss of membrane integrity, the decrease in [peroxide]cyt was of a lower magnitude when compared with that preceding the onset of apoptosis in T-cells. Furthermore, decreasing the cytosolic peroxide level in U937 monocytes before the application of synthetic ceramide by pretreatment with either of the antioxidants N-acetyl cysteine or glutathione conferred apoptosis. However, N-acetyl cysteine or glutathione did not affect the kinetics or magnitude of ceramide-induced apoptosis of Jurkat T-cells. Therefore the primary redox effect of cellular ceramide accumulation is to lower the [peroxide]cyt of both primary and immortalized cells, the magnitude of which dictates the cellular response.

Publication DOI: https://doi.org/10.1042/BJ20030693
Divisions: College of Health & Life Sciences
College of Health & Life Sciences > Chronic and Communicable Conditions
Additional Information: The final version of record is available at http://www.biochemj.org/bj/375/bj3750567.htm
Uncontrolled Keywords: apoptosis,ceramide,cytosolic peroxide,growth arrest,reactive oxygen species,redox compartmentalization,Biochemistry
Publication ISSN: 1470-8728
Last Modified: 28 Jun 2024 08:27
Date Deposited: 19 Aug 2019 08:49
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Related URLs: http://www.scop ... tnerID=8YFLogxK (Scopus URL)
http://www.bioc ... 5/bj3750567.htm (Publisher URL)
PURE Output Type: Article
Published Date: 2003-07-23
Authors: Phillips, Darren C.
Griffiths, Helen R. (ORCID Profile 0000-0002-2666-2147)



Version: Accepted Version

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