Activation of the mouse heme oxygenase-1 gene by 15-deoxy-Delta(12,14)-prostaglandin J(2) is mediated by the stress response elements and transcription factor Nrf2.
The mechanism of heme oxygenase-1 (ho-1) gene activation by 15-deoxy-Delta(12,14)-prostaglandin J(2) (15d-PGJ(2)) was examined. 15d-PGJ(2) stimulated expression of HO-1 mRNA and protein and of a mouse ho-1 gene promoter/luciferase fusion construct (HO15luc) in a dose-dependent manner in mouse hepatoma (Hepa) cells. HO15luc expression was not effected by troglitazone, a peroxisome proliferator-activated receptor-gamma (PPAR-gamma) ligand, but induction by 15d-PGJ(2) was abrogated by the antioxidant N-acetylcysteine. The primary 15d-PGJ(2) responsive sequences were localized to a 5' distal enhancer (E1) and identified as the stress-response element, previously shown to mediate ho-1 activation by several agents, including heme and heavy metals. Treatment of Hepa cells with 15d-PGJ(2) stimulated stress-response element-binding activity as judged by electrophoretic mobility shift assays. Antibody "supershift" experiments identified NF-E2 related factor 2 (Nrf2), but not Fos, Jun, or activating transcription factor/cyclic AMP response element binding protein transcription factors, within the 15d-PGJ(2)-induced complexes. Similarly, a dominant-negative mutant of Nrf2, but not of c-Jun or c-Fos, abrogated 15d-PGJ(2)-stimulated E1 transcription activity. Finally, prior induction of HO-1 in RAW264.7 mouse macrophages by 15d-PGJ(2) attenuated cell death caused by diesel exhaust particle extracts. These results demonstrate that induction of mouse HO-1 expression by 15d-PGJ(2) is independent of PPAR-gamma but dependent on oxidative stress, is regulated by the oxidative stress-activated transcription factor Nrf2, and provides cytoprotective activity.
Gong
Pengfei
P
Department of Molecular Genetics, Alton Ochsner Medical Foundation, New Orleans, LA 70121, USA.
Stewart
Daniel
D
Hu
Bin
B
Li
Ning
N
Cook
Julia
J
Nel
Andre
A
Alam
Jawed
J
D000818:Animals; D002460:Cell Line; D004742:Enhancer Elements, Genetic / Q000187:drug effects; D004790:Enzyme Induction / Q000187:drug effects; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects*; D006419:Heme Oxygenase (Decyclizing) / Q000096:biosynthesis / Q000235:genetics* / Q000378:metabolism; D051547:Heme Oxygenase-1; D007155:Immunologic Factors / Q000494:pharmacology; D007700:Kinetics; D008114:Liver Neoplasms, Experimental; D008264:Macrophages; D008565:Membrane Proteins; D051379:Mice; D011401:Promoter Regions, Genetic; D015230:Prostaglandin D2 / Q000031:analogs & derivatives* / Q000494:pharmacology*; D011458:Prostaglandins E / Q000494:pharmacology; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis / Q000378:metabolism; D014158:Transcription, Genetic / Q000187:drug effects; D015533:Transcriptional Activation; D014407:Tumor Cells, Cultured
C097240:15-deoxy-delta(12,14)-prostaglandin J2; D007155:Immunologic Factors; D008565:Membrane Proteins; D011458:Prostaglandins E; D011993:Recombinant Fusion Proteins; D006419:Heme Oxygenase (Decyclizing); D051547:Heme Oxygenase-1; C496542:Hmox1 protein, mouse; D015230:Prostaglandin D2