Document Type
Article
Journal Title
The Journal of biological chemistry
Publication Date
9-25-2009
Volume
284
Abstract
Free fatty acids (FFA) induce hepatocyte lipoapoptosis by a c-Jun N-terminal kinase (JNK)-dependent mechanism. However, the cellular processes by which JNK engages the core apoptotic machinery during lipotoxicity, especially activation of BH3-only proteins, remain incompletely understood. Thus, our aim was to determine whether JNK mediates induction of BH3-only proteins during hepatocyte lipoapoptosis. The saturated FFA palmitate, but not the monounsaturated FFA oleate, induces an increase in PUMA mRNA and protein levels. Palmitate induction of PUMA was JNK1-dependent in primary murine hepatocytes. Palmitate-mediated PUMA expression was inhibited by a dominant negative c-Jun, and direct binding of a phosphorylated c-Jun containing the activator protein 1 complex to the PUMA promoter was identified by electrophoretic mobility shift assay and a chromatin immunoprecipitation assay. Short hairpin RNA-targeted knockdown of PUMA attenuated Bax activation, caspase 3/7 activity, and cell death. Similarly, the genetic deficiency of Puma rendered murine hepatocytes resistant to lipoapoptosis. PUMA expression was also increased in liver biopsy specimens from patients with non-alcoholic steatohepatitis as compared with patients with simple steatosis or controls. Collectively, the data implicate JNK1-dependent PUMA expression as a mechanism contributing to hepatocyte lipoapoptosis.
MeSH Headings
Animals, Anthracenes, Apoptosis, Apoptosis Regulatory Proteins, Cell Line, Tumor, Dose-Response Relationship, Drug, Fatty Liver, Gene Expression, Hepatocytes, Humans, Immunoblotting, Mice, Mice, Inbred C57BL, Mice, Knockout, Microscopy, Fluorescence, Mitogen-Activated Protein Kinase 8, Palmitates, Phosphorylation, Proto-Oncogene Proteins, RNA Interference, Reverse Transcriptase Polymerase Chain Reaction, Tumor Suppressor Proteins, bcl-2-Associated X Protein
ISSN
1083-351X
DOI Link
Recommended Citation
Cazanave, Sophie C.; Mott, Justin L.; Elmi, Nafisa A.; Bronk, Steven F.; Werneburg, Nathan W.; Akazawa, Yuko; Kahraman, Alisan; Garrison, Sean P.; Zambetti, Gerard P.; Charlton, Michael R.; and Gores, Gregory J., "JNK1-dependent PUMA expression contributes to hepatocyte lipoapoptosis." (2009). Journal Articles: Biochemistry & Molecular Biology. 16.
https://digitalcommons.unmc.edu/com_bio_articles/16
Supplemental Data
Comments
This research was originally published in Journal of biological chemistry. Cazanave S, Mott JL, Elmi NA, Bronk SF, Werneburg NW, Akazawa Y, Kahraman A, Garrison SP, Zambetti GP, Charlton MR, Gores GJ. JNK1-dependent PUMA expression contributes to hepatocyte lipoapoptosis. Journal of biological chemistry. 2009. 284:26591-602. © the American Society for Biochemistry and Molecular Biology