title: Modulation of keratinocyte expression of antioxidants by 4-hydroxynonenal, a lipid peroxidation end product.
abstract: 4-Hydroxynonenal (4-HNE) is a lipid peroxidation end product generated in response to oxidative stress in the skin. Keratinocytes contain an array of antioxidant enzymes which protect against oxidative stress. In these studies, we characterized 4-HNE-induced changes in antioxidant expression in mouse keratinocytes. Treatment of primary mouse keratinocytes and PAM 212 keratinocytes with 4-HNE increased mRNA expression for heme oxygenase-1 (HO-1), catalase, NADPH:quinone oxidoreductase (NQO1) and glutathione S-transferase (GST) A1-2, GSTA3 and GSTA4. In both cell types, HO-1 was the most sensitive, increasing 86-98 fold within 6h. Further characterization of the effects of 4-HNE on HO-1 demonstrated concentration- and time-dependent increases in mRNA and protein expression which were maximum after 6h with 30 μM. 4-HNE stimulated keratinocyte Erk1/2, JNK and p38 MAP kinases, as well as PI3 kinase. Inhibition of these enzymes suppressed 4-HNE-induced HO-1 mRNA and protein expression. 4-HNE also activated Nrf2 by inducing its translocation to the nucleus. 4-HNE was markedly less effective in inducing HO-1 mRNA and protein in keratinocytes from Nrf2-/- mice, when compared to wild type mice, indicating that Nrf2 also regulates 4-HNE-induced signaling. Western blot analysis of caveolar membrane fractions isolated by sucrose density centrifugation demonstrated that 4-HNE-induced HO-1 is localized in keratinocyte caveolae. Treatment of the cells with methyl-β-cyclodextrin, which disrupts caveolar structure, suppressed 4-HNE-induced HO-1. These findings indicate that 4-HNE modulates expression of antioxidant enzymes in keratinocytes, and that this can occur by different mechanisms. Changes in expression of keratinocyte antioxidants may be important in protecting the skin from oxidative stress.
authors.affiliation: Pharmacology and Toxicology and Pharmaceutics, Ernest Mario School of Pharmacy, Rutgers University, Piscataway, NJ, USA.
authors.forename: Ruijin
authors.initials: R
authors.lastname: Zheng
authors.affiliation: Environmental Health Science, New York Medical College, Valhalla, NY, USA.
authors.forename: Diane E
authors.initials: DE
authors.lastname: Heck
authors.affiliation: Pharmacology and Toxicology and Pharmaceutics, Ernest Mario School of Pharmacy, Rutgers University, Piscataway, NJ, USA.
authors.forename: Vladimir
authors.initials: V
authors.lastname: Mishin
authors.affiliation: Pharmacology and Toxicology and Pharmaceutics, Ernest Mario School of Pharmacy, Rutgers University, Piscataway, NJ, USA.
authors.forename: Adrienne T
authors.initials: AT
authors.lastname: Black
authors.affiliation: Environmental Health Science, New York Medical College, Valhalla, NY, USA.
authors.forename: Michael P
authors.initials: MP
authors.lastname: Shakarjian
authors.affiliation: Pharmacology and Toxicology and Pharmaceutics, Ernest Mario School of Pharmacy, Rutgers University, Piscataway, NJ, USA.
authors.forename: Ah-Ng Tony
authors.initials: AN
authors.lastname: Kong
authors.affiliation: Pharmacology and Toxicology and Pharmaceutics, Ernest Mario School of Pharmacy, Rutgers University, Piscataway, NJ, USA.
authors.forename: Debra L
authors.initials: DL
authors.lastname: Laskin
authors.affiliation: Environmental and Occupational Medicine, Rutgers University-Robert Wood Johnson Medical School, Piscataway, NJ, USA. Electronic address: jlaskin@eohsi.rutgers.edu.
authors.forename: Jeffrey D
authors.initials: JD
authors.lastname: Laskin
mesh_terms: D000447:Aldehydes / Q000494:pharmacology*; D000818:Animals; D000975:Antioxidants / Q000378:metabolism*; D021941:Caveolae / Q000187:drug effects / Q000378:metabolism; D002460:Cell Line; D005982:Glutathione Transferase / Q000235:genetics / Q000378:metabolism; D051547:Heme Oxygenase-1 / Q000235:genetics / Q000378:metabolism; D015603:Keratinocytes / Q000187:drug effects* / Q000378:metabolism; D015227:Lipid Peroxidation / Q000187:drug effects*; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D048052:Mitogen-Activated Protein Kinase 3 / Q000235:genetics / Q000378:metabolism; D016660:NAD(P)H Dehydrogenase (Quinone) / Q000235:genetics / Q000378:metabolism; D051267:NF-E2-Related Factor 2 / Q000235:genetics / Q000378:metabolism; D018384:Oxidative Stress / Q000187:drug effects; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction; D047392:beta-Cyclodextrins / Q000494:pharmacology; D048051:p38 Mitogen-Activated Protein Kinases / Q000235:genetics / Q000378:metabolism
chemical_list: D000447:Aldehydes; D000975:Antioxidants; D008565:Membrane Proteins; D051267:NF-E2-Related Factor 2; C495636:Nfe2l2 protein, mouse; D012333:RNA, Messenger; D047392:beta-Cyclodextrins; C108732:methyl-beta-cyclodextrin; D051547:Heme Oxygenase-1; C496542:Hmox1 protein, mouse; D016660:NAD(P)H Dehydrogenase (Quinone); C491732:Nqo1 protein, mouse; D005982:Glutathione Transferase; D048052:Mitogen-Activated Protein Kinase 3; D048051:p38 Mitogen-Activated Protein Kinases; C027576:4-hydroxy-2-nonenal
keywords: Antioxidants; Caveolae; Heme oxygenase-1; Nrf2; Skin; Stress proteins