title: Sulforaphane and phenylethyl isothiocyanate protect human skin against UVR-induced oxidative stress and apoptosis: role of Nrf2-dependent gene expression and antioxidant enzymes.
abstract: Chronic UVR-exposure may impair the stress response and antioxidant defense mechanisms of human skin. The transcription factor nuclear factor erythroid-2 related factor 2 (Nrf2) orchestrates the expression of genes coding for the stress response and antioxidant proteins. Here, we tested sulforaphane (SFN) and phenylethyl isothiocyanate (PEITC) for their ability to counteract UVR-induced oxidative stress and apoptosis in ex vivo human full-thickness skin combined with in vitro HaCaT keratinocytes. Investigation of Nrf2 transactivation and induction of genes coding for Nrf2-dependent phase II antioxidative enzymes (γ-glutamylcysteine-synthetase (γGCS), heme oxygenase 1 (HO-1) and NAD(P)H quinone oxidoreductase 1 (NQO1)) was performed in HaCaT keratinocytes. Comparative investigations in human ex vivo skin were conducted for analysis of gene expression of above mentioned phase II enzymes and catalase (CAT) as well as hematoxylin/eosin (H&E) and immunofluorescence (catalase, cleaved Casp-3). UVR exposure of human skin (300mJ/cm(2)) resulted in a significant time-dependent increase of the number of sunburn cells and caspase-3 activation as biomarkers of apoptosis for up to 48h (p<0.001) and induced a significant decrease of the antioxidant enzyme catalase (p<0.001). This was significantly counteracted by the pre-treatment of human skin with SFN and PEITC (5μM and 10μM). Mechanistic cell culture studies revealed SFN and PEITC to increase Nrf2 activity and Nrf2-dependent gene expression (γGCS, HO-1, NQO1); this was paralleled in human full skin mRNA. In conclusion, the induction of Nrf2-dependent antioxidant pathways seems to be a potential mechanism by which SFN and PEITC protect against UVR-induced oxidative stress and apoptosis in human skin.
authors.affiliation: Department of Dermatology, University of Lübeck, Ratzeburger Allee 160, 23538 Lübeck, Germany.
authors.forename: Konrad
authors.initials: K
authors.lastname: Kleszczyński
authors.forename: Insa M A
authors.initials: IM
authors.lastname: Ernst
authors.forename: Anika E
authors.initials: AE
authors.lastname: Wagner
authors.forename: Nathalie
authors.initials: N
authors.lastname: Kruse
authors.forename: Detlef
authors.initials: D
authors.lastname: Zillikens
authors.forename: Gerald
authors.initials: G
authors.lastname: Rimbach
authors.forename: Tobias W
authors.initials: TW
authors.lastname: Fischer
mesh_terms: D016588:Anticarcinogenic Agents / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects / Q000528:radiation effects; D053148:Caspase 3 / Q000378:metabolism; D002374:Catalase / Q000378:metabolism; D002460:Cell Line; D005786:Gene Expression Regulation / Q000187:drug effects / Q000528:radiation effects; D006801:Humans; D017879:Isothiocyanates / Q000494:pharmacology*; D051267:NF-E2-Related Factor 2 / Q000235:genetics / Q000378:metabolism*; D018384:Oxidative Stress / Q000187:drug effects / Q000528:radiation effects; D012867:Skin / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology / Q000528:radiation effects*; D013454:Sulfoxides; D014466:Ultraviolet Rays
chemical_list: D016588:Anticarcinogenic Agents; D017879:Isothiocyanates; D051267:NF-E2-Related Factor 2; C495635:NFE2L2 protein, human; D013454:Sulfoxides; C058305:phenethyl isothiocyanate; D002374:Catalase; D053148:Caspase 3; C016766:sulforaphane
keywords: Apoptosis; CAT; GSH; H&E; HO-1; NAD(P)H quinone oxidoreductase 1; NQO1; Nrf2; Oxidative stress; PEITC; Phenylethyl isothiocyanate; SFN; Skin; Sulforaphane; UVR; catalase; cl. casp-3; cleaved caspase-3; glutathione; hematoxylin and eosin; heme oxygenase 1; nuclear factor erythroid-2 related factor 2; phenylethyl isothiocyanate; sulforaphane; ultraviolet radiation; γ-glutamylcysteine-synthetase; γGCS