Nrf2 up-regulates the induction of acidic sphingomyelinase by electrophiles.

Abstract

Acidic sphingomyelinase (ASMase) catalyses the generation of ceramide from sphingomyelin. Ceramide is a lipid mediator and is implicated in mediating and regulating various cellular processes including cell proliferation, differentiation, stress response and inflammation. We have previously reported that electrophiles including diethyl maleate (DEM), heavy metals and cigarette smoke extracts induced ASMase expression in human bladder carcinoma ECV-304 cells, but the mechanism of ASMase mRNA induction by electrophiles remains unknown. In this study, we clarified the involvement of NF-E2-related factor 2 (Nrf2) in the induction of ASMase mRNA by DEM. Promoter analysis using a series of deletion mutants of the human ASMase gene showed that ARE-like element1 located in a region between -200 and -160 bp upstream of the transcription start point is mainly a DEM-responsive element. Moreover, an electrophoretic mobility shift assay using ARE-like element1 revealed that Nrf2 is a candidate transcription factor that binds to ARE-like element1 in response to DEM. Finally, alteration of Nrf2 expression by overexpression and knockdown could regulate the induction of ASMase mRNA by DEM. This is the first evidence that supports the possibility that sphingolipid metabolism is affected via the induction of ASMase by the Nrf2 pathway.

• Authors: Takeshi Kumagai, Yosuke Kozakai, Tomohiro Ishino, Yuichi Yajima, Yasuhito Nakagawa, Hirotaka Imai
• Journal: Journal of biochemistry (J Biochem) Vol. 158 Issue 2 Pg. 127-37 (Aug 2015) ISSN: 1756-2651 [Electronic] England
• PMID: 25762726 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: © The Authors 2015. Published by Oxford University Press on behalf of the Japanese Biochemical Society. All rights reserved.

Chemical References

• Maleates
• NF-E2-Related Factor 2
• RNA, Messenger
• Sphingomyelin Phosphodiesterase
• diethyl maleate

Topics

• Base Sequence
• Cell Line, Tumor
• Gene Expression Regulation, Neoplastic (drug effects)
• Humans
• Maleates (pharmacology)
• Molecular Sequence Data
• NF-E2-Related Factor 2 (metabolism)
• Protein Binding (drug effects, genetics)
• RNA, Messenger (genetics, metabolism)
• Response Elements (genetics)
• Sphingomyelin Phosphodiesterase (genetics, metabolism)
• Up-Regulation (drug effects, genetics)