title: Attenuation of UVB-induced sunburn reaction and oxidative DNA damage with no alterations in UVB-induced skin carcinogenesis in Nrf2 gene-deficient mice.
abstract: UV radiation is an important environmental factor in the pathogenesis of skin aging and cancer. Many harmful effects of UV radiation are associated with generation of reactive oxygen species. Cellular antioxidants prevent the occurrence and reduce the severity of UV-induced photoaging and diseases of the skin. The transcription factor Nrf2 (NF-E2-related factor 2) and its negative regulator protein, Keap1 (Kelch-like-ECH-associated protein 1), are central regulators of cellular antioxidant responses. We used nrf2-null mice to investigate the roles of the Nrf2-Keap1 system in protection of skin from harmful effects of UVB irradiation. A single irradiation with UVB induced stronger and longer lasting sunburn reaction in nrf2-null mice. Histological changes, including epidermal necrosis, dermal edema, inflammatory cell infiltration, sunburn cell formation, TUNEL-positive apoptotic cell formation, and accumulation of oxidative DNA products such as 8-hydroxy-2'-deoxyguanosine after UVB irradiation, were more prominent in nrf2-null mice. These findings indicate that the Nrf2-Keap1 pathway plays an important role in protection of the skin against acute UVB reactions, including cutaneous cell apoptosis and oxidative damage. However, there were no significant differences in skin carcinogenesis between nrf2-null and wild-type mice exposed to chronic UVB irradiation, suggesting that there is a complex and subtle balance between factors promoting and preventing photocarcinogenesis. Journal of Investigative Dermatology (2008) 128, 1773-1779; doi:10.1038/sj.jid.5701245; published online 17 January 2008.
authors.affiliation: Department of Dermatology, Institute of Clinical Medicine, University of Tsukuba, Tsukuba, Ibaraki, Japan. kyasuhir@md.tsukuba.ac.jp
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Kawachi
authors.forename: Xuezhu
authors.initials: X
authors.lastname: Xu
authors.forename: Shiroma
authors.initials: S
authors.lastname: Taguchi
authors.forename: Hideko
authors.initials: H
authors.lastname: Sakurai
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Nakamura
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Ishii
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Fujisawa
authors.forename: Junichi
authors.initials: J
authors.lastname: Furuta
authors.forename: Takenori
authors.initials: T
authors.lastname: Takahashi
authors.forename: Ken
authors.initials: K
authors.lastname: Itoh
authors.forename: Masayuki
authors.initials: M
authors.lastname: Yamamoto
authors.forename: Fumikazu
authors.initials: F
authors.lastname: Yamazaki
authors.forename: Fujio
authors.initials: F
authors.lastname: Otsuka
mesh_terms: D000080242:8-Hydroxy-2'-Deoxyguanosine; D000818:Animals; D004249:DNA Damage; D003849:Deoxyguanosine / Q000031:analogs & derivatives / Q000032:analysis; D005260:Female; D020287:In Situ Nick-End Labeling; D047908:Intracellular Signaling Peptides and Proteins / Q000502:physiology; D000072019:Kelch-Like ECH-Associated Protein 1; D051379:Mice; D008807:Mice, Inbred BALB C; D051267:NF-E2-Related Factor 2 / Q000235:genetics / Q000502:physiology*; D009381:Neoplasms, Radiation-Induced / Q000209:etiology*; D010084:Oxidation-Reduction; D012878:Skin Neoplasms / Q000209:etiology*; D013471:Sunburn / Q000517:prevention & control*; D014466:Ultraviolet Rays / Q000009:adverse effects*
chemical_list: D047908:Intracellular Signaling Peptides and Proteins; C431364:KEAP1 protein, human; D000072019:Kelch-Like ECH-Associated Protein 1; D051267:NF-E2-Related Factor 2; C495636:Nfe2l2 protein, mouse; D000080242:8-Hydroxy-2'-Deoxyguanosine; D003849:Deoxyguanosine