Selective Activation of the c-Jun N-Terminal Protein Kinase Pathway during 4-Hydroxynonenal-Induced Apoptosis of PC12 Cells

• Published in: Molecular pharmacology Vol. 58; no. 3; pp. 535 - 541
• Main Authors: Soh, Y, Jeong, K S, Lee, I J, Bae, M A, Kim, Y C, Song, B J
• Format: Journal Article
• Language: English
• Published: United States American Society for Pharmacology and Experimental Therapeutics 01.09.2000
• Subjects: Aldehydes - pharmacology; Animals; Apoptosis - physiology; Cell Survival - drug effects; COS Cells; Cyclic AMP - analogs & derivatives; Cyclic AMP - pharmacology; Cysteine Proteinase Inhibitors - pharmacology; Dose-Response Relationship, Drug; Enzyme Activation; Enzyme Inhibitors - pharmacology; Imidazoles - pharmacology; JNK Mitogen-Activated Protein Kinases; MAP Kinase Kinase Kinase 5; MAP Kinase Kinase Kinases - metabolism; Mitogen-Activated Protein Kinase 8; Mitogen-Activated Protein Kinase Kinases - metabolism; Mitogen-Activated Protein Kinases - metabolism; PC12 Cells; Phosphorylation; Pyridines - pharmacology; Rats; Thionucleotides - pharmacology; Time Factors
• ISSN: 0026-895X; 1521-0111
• DOI: 10.1124/mol.58.3.535

The by-product of lipid peroxidation, 4-hydroxynonenal (HNE), was shown to cause apoptosis in PC12 cells. In this study, we investigated the molecular mechanism of HNE-induced apoptosis in these cells. Specifically, we determined the effect of HNE on the activities of mitogen-activated protein (MAP) kinases involved in early signal transduction. Within 15 to 30 min after HNE treatment, c-Jun N-terminal protein kinase (JNK) was maximally activated, before it returned to control level at 1 h post-treatment. In contrast, activities of extracellular signal-regulated kinase and p38 MAP kinase remained unchanged from their baseline levels. Stress-activated protein kinase kinase (SEK1), an upstream kinase of JNK, was also activated within 5 min after HNE treatment and remained activated for up to 60 min. Marked activation of the JNK pathway through SEK1 and apoptosis signal-regulating kinase 1 (ASK1), an upstream kinase of SEK1, was demonstrated by the transient transfection of cDNA for wild-type SEK1 or ASK1 together with JNK into COS-7 cells. Furthermore, significant reductions in JNK activation and HNE-induced cell death were observed when either of the dominant negative mutant of SEK1 or ASK1 was cotransfected with JNK. Pretreatment of PC12 cells with a survival-promoting agent, 8-(4-chlorophenylthio)-cAMP, prevented both the HNE-induced JNK activation and apoptosis. Nonaldehyde, a nontoxic aldehyde, neither caused apoptosis nor JNK activation. Pretreatment of PC12 cells with SB203580, a specific inhibitor of p38 MAP kinase, had no effect on HNE-induced apoptosis. All these data suggest that the selective JNK activation by HNE is critical for the apoptosis of PC12 cells and that the HNE-mediated apoptosis is likely to be mediated through the activation of the ASK1-SEK1-JNK pathway without activation of extracellular signal-regulated kinase or p38 MAP kinase.