title: Regulation of keratinocyte expression of stress proteins and antioxidants by the electrophilic nitrofatty acids 9- and 10-nitrooleic acid.
abstract: Nitric oxide and various by-products including nitrite contribute to tissue injury by forming novel intermediates via redox-mediated nitration reactions. Nitration of unsaturated fatty acids generates electrophilic nitrofatty acids such as 9-nitrooleic acid (9-NO) and 10-nitrooleic acid (10-NO), which are known to initiate intracellular signaling pathways. In these studies, we characterized nitrofatty acid-induced signaling and stress protein expression in mouse keratinocytes. Treatment of keratinocytes with 5-25μM 9-NO or 10-NO for 6h upregulated mRNA expression of heat shock proteins (hsp's) 27 and 70; primary antioxidants heme oxygenase-1 (HO-1) and catalase; secondary antioxidants glutathione S-transferase (GST) A1/2, GSTA3, and GSTA4; and Cox-2, a key enzyme in prostaglandin biosynthesis. The greatest responses were evident with HO-1, hsp27, and hsp70. In keratinocytes, 9-NO activated JNK and p38 MAP kinases. JNK inhibition suppressed 9-NO-induced HO-1, hsp27, and hsp70 mRNA and protein expression, whereas p38 MAP kinase inhibition suppressed HO-1. In contrast, inhibition of constitutive expression of Erk1/2 suppressed only hsp70, indicating that 9-NO modulates expression of stress proteins by distinct mechanisms. 9-NO and 10-NO also upregulated expression of caveolin-1, the major structural component of caveolae. Western blot analysis of caveolar membrane fractions isolated by sucrose density centrifugation revealed that HO-1, hsp27, and hsp70 were localized within caveolae after nitrofatty acid treatment of keratinocytes, suggesting a link between induction of stress response proteins and caveolin-1 expression. These data indicate that nitrofatty acids are effective signaling molecules in keratinocytes. Moreover, caveolae seem to be important in the localization of stress proteins in response to nitrofatty acids.
authors.affiliation: Pharmacology & Toxicology and Robert Wood Johnson Medical School, Rutgers University, Piscataway, NJ 08854, USA.
authors.forename: Ruijin
authors.initials: R
authors.lastname: Zheng
authors.affiliation: Environmental Health Science, New York Medical College, Valhalla, NY 10595, USA.
authors.forename: Diane E
authors.initials: DE
authors.lastname: Heck
authors.affiliation: Pharmacology & Toxicology and Robert Wood Johnson Medical School, Rutgers University, Piscataway, NJ 08854, USA.
authors.forename: Adrienne T
authors.initials: AT
authors.lastname: Black
authors.affiliation: Pharmacology & Toxicology and Robert Wood Johnson Medical School, Rutgers University, Piscataway, NJ 08854, USA.
authors.forename: Andrew
authors.initials: A
authors.lastname: Gow
authors.affiliation: Pharmacology & Toxicology and Robert Wood Johnson Medical School, Rutgers University, Piscataway, NJ 08854, USA.
authors.forename: Debra L
authors.initials: DL
authors.lastname: Laskin
authors.affiliation: Environmental & Occupational Medicine, Robert Wood Johnson Medical School, Rutgers University, Piscataway, NJ 08854, USA. Electronic address: jlaskin@eohsi.rutgers.edu.
authors.forename: Jeffrey D
authors.initials: JD
authors.lastname: Laskin
mesh_terms: D000818:Animals; D002374:Catalase / Q000235:genetics / Q000378:metabolism; D021941:Caveolae / Q000187:drug effects* / Q000378:metabolism; D002460:Cell Line; D051546:Cyclooxygenase 2 / Q000235:genetics / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D005786:Gene Expression Regulation / Q000187:drug effects*; D005982:Glutathione Transferase / Q000235:genetics / Q000378:metabolism; D055551:HSP27 Heat-Shock Proteins / Q000235:genetics / Q000378:metabolism; D018840:HSP70 Heat-Shock Proteins / Q000235:genetics / Q000378:metabolism; D051547:Heme Oxygenase-1 / Q000235:genetics / Q000378:metabolism; D007527:Isoenzymes / Q000235:genetics / Q000378:metabolism; D015603:Keratinocytes / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D048670:MAP Kinase Kinase 4 / Q000235:genetics / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D019950:Mitogen-Activated Protein Kinase 1 / Q000235:genetics / Q000378:metabolism; D048052:Mitogen-Activated Protein Kinase 3 / Q000235:genetics / Q000378:metabolism; D009829:Oleic Acids / Q000494:pharmacology*; D015398:Signal Transduction / Q000187:drug effects* / Q000235:genetics; D048051:p38 Mitogen-Activated Protein Kinases / Q000235:genetics / Q000378:metabolism
chemical_list: C521487:10-nitro-oleic acid; D055551:HSP27 Heat-Shock Proteins; D018840:HSP70 Heat-Shock Proteins; D007527:Isoenzymes; D009829:Oleic Acids; D002374:Catalase; D051547:Heme Oxygenase-1; C077623:Ptgs2 protein, mouse; D051546:Cyclooxygenase 2; D005982:Glutathione Transferase; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D048051:p38 Mitogen-Activated Protein Kinases; D048670:MAP Kinase Kinase 4
keywords: Free radicals; Heat shock proteins; Heme oxygenase-1; Nitric oxide; Nitrooleic acid; Skin