title: Peroxynitrite production, DNA breakage, and poly(ADP-ribose) polymerase activation in a mouse model of oxazolone-induced contact hypersensitivity.
abstract: Peroxynitrite-induced poly(ADP-ribose) polymerase activation has been implicated in the pathogenesis of various inflammatory conditions. Here we have investigated whether peroxynitrite and poly(ADP-ribose) polymerase may play a role in the pathophysiology of the elicitation phase of contact hypersensitivity. We have detected nitrotyrosine, DNA breakage, and poly(ADP-ribose) polymerase activation in the epidermis of mice in an oxazolone-induced contact hypersensitivity model. As tyrosine nitration is mostly mediated by peroxynitrite, a nitric-oxide-derived cytotoxic oxidant capable of causing DNA breakage, we have applied peroxynitrite directly on mouse skin and showed poly(ADP-ribose) polymerase activation in keratinocytes and in some scattered dermal cells. We have also investigated the cellular effects of peroxynitrite in HaCaT cells, a human keratinocyte cell line. We found that peroxynitrite inhibited cell proliferation and at higher concentrations also caused cytotoxicity. Peroxynitrite activates poly(ADP-ribose) polymerase in HaCaT cells and poly(ADP-ribose) polymerase activation contributes to peroxynitrite-induced cytotoxicity, as indicated by the cytoprotective effect of the poly(ADP-ribose) polymerase inhibitor 3-aminobenzamide. The cytoprotective effect of 3-aminobenzamide cannot be attributed to inhibition of apoptosis, as apoptotic parameters (caspase activation and DNA fragmentation) were not reduced in the presence of 3-aminobenzamide in peroxynitrite-treated cells. Moreover, poly(ADP-ribose) polymerase inhibition by 3-aminobenzamide dose-dependently reduced interferon-induced intercellular adhesion molecule 1 expression as well as interleukin-1beta-induced interleukin-8 expression. Our results indicate that peroxynitrite and poly(ADP-ribose) polymerase regulate keratinocyte function and death in contact hypersensitivity.
authors.affiliation: Inotek Corporation, Beverly, Massachusetts, USA.
authors.forename: E
authors.initials: E
authors.lastname: Szabó
authors.forename: L
authors.initials: L
authors.lastname: Virág
authors.forename: E
authors.initials: E
authors.lastname: Bakondi
authors.forename: L
authors.initials: L
authors.lastname: Gyüre
authors.forename: G
authors.initials: G
authors.lastname: Haskó
authors.forename: P
authors.initials: P
authors.lastname: Bai
authors.forename: J
authors.initials: J
authors.lastname: Hunyadi
authors.forename: P
authors.initials: P
authors.lastname: Gergely
authors.forename: C
authors.initials: C
authors.lastname: Szabó
mesh_terms: D000276:Adjuvants, Immunologic; D000818:Animals; D017209:Apoptosis / Q000187:drug effects / Q000502:physiology; D020169:Caspases / Q000378:metabolism; D002455:Cell Division / Q000187:drug effects / Q000502:physiology; D002460:Cell Line; D004249:DNA Damage / Q000502:physiology*; D053938:DNA Fragmentation / Q000502:physiology; D003877:Dermatitis, Contact / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D005260:Female; D020287:In Situ Nick-End Labeling; D018799:Intercellular Adhesion Molecule-1 / Q000096:biosynthesis; D016209:Interleukin-8 / Q000276:immunology; D015603:Keratinocytes / Q000276:immunology / Q000378:metabolism / Q000473:pathology; D051379:Mice; D008815:Mice, Inbred Strains; D009336:Necrosis; D009566:Nitrates / Q000378:metabolism*; D010081:Oxazolone; D011065:Poly(ADP-ribose) Polymerases / Q000378:metabolism*; D012867:Skin / Q000276:immunology / Q000378:metabolism / Q000473:pathology; D014443:Tyrosine / Q000378:metabolism
chemical_list: D000276:Adjuvants, Immunologic; D016209:Interleukin-8; D009566:Nitrates; D018799:Intercellular Adhesion Molecule-1; D010081:Oxazolone; C039642:peroxynitric acid; D014443:Tyrosine; D011065:Poly(ADP-ribose) Polymerases; D020169:Caspases