title: Retinoic acid inhibits induction of c-Jun protein by ultraviolet radiation that occurs subsequent to activation of mitogen-activated protein kinase pathways in human skin in vivo.
abstract: Human skin is exposed daily to solar ultraviolet (UV) radiation. UV induces the matrix metalloproteinases collagenase, 92-kD gelatinase, and stromelysin, which degrade skin connective tissue and may contribute to premature skin aging (photoaging). Pretreatment of skin with all-trans retinoic acid (tRA) inhibits UV induction of matrix metalloproteinases. We investigated upstream signal transduction pathways and the mechanism of tRA inhibition of UV induction of matrix metalloproteinases in human skin in vivo. Exposure of human skin in vivo to low doses of UV activated EGF receptors, the GTP-binding regulatory protein p21Ras, and stimulated mitogen-activated protein (MAP) kinases, extracellular signal-regulated kinase (ERK), c-Jun amino-terminal kinase (JNK), and p38. Both JNK and p38 phosphorylated, and thereby activated transcription factors c-Jun and activating transcription factor 2 (ATF-2), which bound to the c-Jun promoter and upregulated c-Jun gene expression. Elevated c-Jun, in association with constitutively expressed c-Fos, formed increased levels of transcription factor activator protein (AP) 1, which is required for transcription of matrix metalloproteinases. Pretreatment of human skin with tRA inhibited UV induction of c-Jun protein and, consequently, AP-1. c-Jun protein inhibition occurred via a posttranscriptional mechanism, since tRA did not inhibit UV induction of c-Jun mRNA. These data demonstrate, for the first time, activation of MAP kinase pathways in humans in vivo, and reveal a novel posttranscriptional mechanism by which tRA antagonizes UV activation of AP-1 by inhibiting c-Jun protein induction. Inhibition of c-Jun induction likely contributes to the previously reported prevention by tRA of UV induction of AP-1-regulated matrix-degrading metalloproteinases in human skin.
authors.affiliation: Department of Dermatology, University of Michigan Medical School, Ann Arbor, Michigan 48109-0609, USA. dianemch@umich.edu
authors.forename: G J
authors.initials: GJ
authors.lastname: Fisher
authors.forename: H S
authors.initials: HS
authors.lastname: Talwar
authors.forename: J
authors.initials: J
authors.lastname: Lin
authors.forename: P
authors.initials: P
authors.lastname: Lin
authors.forename: F
authors.initials: F
authors.lastname: McPhillips
authors.forename: Z
authors.initials: Z
authors.lastname: Wang
authors.forename: X
authors.initials: X
authors.lastname: Li
authors.forename: Y
authors.initials: Y
authors.lastname: Wan
authors.forename: S
authors.initials: S
authors.lastname: Kang
authors.forename: J J
authors.initials: JJ
authors.lastname: Voorhees
mesh_terms: D051698:Activating Transcription Factor 2; D000970:Antineoplastic Agents / Q000494:pharmacology*; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000378:metabolism / Q000494:pharmacology / Q000528:radiation effects; D017362:Cyclic AMP Response Element-Binding Protein / Q000378:metabolism; D066246:ErbB Receptors / Q000378:metabolism / Q000528:radiation effects; D015870:Gene Expression; D006801:Humans; D048031:JNK Mitogen-Activated Protein Kinases; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism / Q000494:pharmacology / Q000528:radiation effects; D009419:Nerve Tissue Proteins / Q000378:metabolism / Q000494:pharmacology / Q000528:radiation effects; D011401:Promoter Regions, Genetic; D016755:Proto-Oncogene Proteins c-jun / Q000235:genetics* / Q000378:metabolism*; D016283:Proto-Oncogene Proteins p21(ras) / Q000378:metabolism / Q000494:pharmacology / Q000528:radiation effects; D015398:Signal Transduction / Q000235:genetics; D012867:Skin / Q000187:drug effects* / Q000378:metabolism / Q000528:radiation effects*; D018808:Transcription Factor AP-1 / Q000378:metabolism; D014157:Transcription Factors / Q000378:metabolism; D014158:Transcription, Genetic; D014212:Tretinoin / Q000494:pharmacology*; D014466:Ultraviolet Rays; D015854:Up-Regulation; D048051:p38 Mitogen-Activated Protein Kinases
chemical_list: C497105:ATF2 protein, human; D051698:Activating Transcription Factor 2; D000970:Antineoplastic Agents; D017362:Cyclic AMP Response Element-Binding Protein; D009419:Nerve Tissue Proteins; D016755:Proto-Oncogene Proteins c-jun; D018808:Transcription Factor AP-1; D014157:Transcription Factors; D014212:Tretinoin; D066246:ErbB Receptors; D017871:Calcium-Calmodulin-Dependent Protein Kinases; D048031:JNK Mitogen-Activated Protein Kinases; D020928:Mitogen-Activated Protein Kinases; D048051:p38 Mitogen-Activated Protein Kinases; C501009:HRAS protein, human; D016283:Proto-Oncogene Proteins p21(ras)