Ceramide Activates the Stress-activated Protein Kinases

doi:10.1074/jbc.270.39.22689

Ceramide Activates the Stress-activated Protein Kinases (*)

From the Departments of Medicine and Biochemistry and Biophysics, Center for Gastrointestinal Biology and Disease, University of North Carolina, Chapel Hill, North Carolina 27599-7038 and the
Departments of Medicine and Cell Biology, Duke University, Durham, North Carolina 27710

^¶ To whom correspondence should be addressed:
C.B. 7080, Dept. of Medicine, University of North Carolina, Chapel Hill, NC 27599-7038.
Tel.: 919-966-7885; Fax: 919-966-7468; dab{at}med.unc.edu

↵^§ Present address: C.B. 7365, Dept. of Pharmacology and Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC 27599-7365. jwesty{at}email.unc.edu

Abstract

Tumor necrosis factor α (TNFα) activates the stress-activated protein kinases (SAPKs, also known as Jun nuclear kinases or JNKs) resulting in the stimulation of AP-1-dependent gene transcription and induces the translocation of NFκB to the nucleus resulting in the stimulation of NFκB-dependent gene transcription. A potential second messenger for these signaling pathways is ceramide, which is generated when TNFα activates sphingomyelinases. We show that treatment of HL-60 human promyelocytic cells with exogenous sphingomyelinase leads to rapid stimulation of JNK/SAPK activity, an effect not mimicked by treatment with phospholipase A, C, or D. Further, JNK/SAPK activity is stimulated 2.7- and 2.8-fold, respectively, in cells exposed to C-ceramide (5 μM) or TNFα (10 ng/ml). The prolonged stimulation of this kinase activity by C-ceramide is similar to that previously reported for TNFα. In contrast, the related mitogen-activated protein kinases ERK1 and ERK2 are weakly stimulated following TNFα treatment (1.5-fold) and are inhibited by C-ceramide treatment. TNFα also potently stimulates NF-κB DNA binding activity and transcriptional activity, but these effects are not mimicked by addition of C-ceramide or sphingomyelinase to intact cells. Furthermore, TNFα, sphingomyelinase, and C-ceramide induce c-jun, a gene that is stimulated by the ATF-2 and c-Jun transcription factors. These data suggest that ceramide may act as a second messenger for a subset of TNFα's biochemical and biological effects.

Footnotes

↵* This work was supported by Grant DK34987 from the University of North Carolina Center for Gastrointestinal Biology and Disease (to J. K. W.) and by National Institutes of Health Grants CA 50528 and GM 41084 (to D. A. B.) and GM 43825 (to Y. A. H.). The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore by hereby marked “advertisement” in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.
↵¹ The abbreviations used are:

TNFα

tumor necrosis factor α

JNK

Jun nuclear kinase

SAPK

stress-activated protein kinase

MAP

mitogen-activated protein

PP2A

protein phosphatase 2A

D-e-C

(2S,3R)-D-erythro-N-acetylsphingosine

GST

glutathione S-transferase

MEK

MAP kinase kinase.
- Received June 28, 1995.
- Revision received August 2, 1995.