title: Changes in matrix gene and protein expressions after single or repeated exposure to one minimal erythemal dose of solar-simulated radiation in human skin in vivo.
abstract: Damage to the skin extracellular matrix (ECM) is the hallmark of long-term exposure to solar UV radiation. The aim of our study was to investigate the changes induced in unexposed human skin in vivo after single or repeated (five times a week for 6 weeks) exposure to 1 minimal erythemal dose (MED) of UV solar-simulated radiation. Morphological and biochemical analyses were used to evaluate the structural ECM components and the balance between the degrading enzymes and their physiologic inhibitors. A three-fold increase in matrix metalloproteinase 2 messenger RNA (mRNA) (P < 0.02, unexposed versus exposed) was observed after both single and repeated exposures. Fibrillin 1 mRNA level was increased by chronic exposure (P < 0.02) and unaltered by a single MED. On the contrary, a single MED significantly enhanced mRNA levels of interleukin-1alpha (IL-1alpha), IL-1beta (P < 0.02) and plasminogen activator inhibitor-1 (P < 0.05). Immunohistochemistry demonstrated a significant decrease in Type-I procollagen localized just below the dermal-epidermal junction in both types of exposed sites. At the same location, the immunodetected tenascin was significantly enhanced, whereas a slight increase in Type-III procollagen deposits was also observed in chronically exposed areas. Although we were unable to observe any change in elastic fibers in chronically exposed buttock skin, a significant increase in lysozyme and alpha-1 antitrypsin deposits on these fibers was observed. These results demonstrate the existence of a differential regulation, after chronic exposure compared with an acute one, of some ECM components and inflammatory mediators.
authors.affiliation: L'Oréal Recherche, Clichy, France. sseite@rd.loreal.com
authors.forename: Sophie
authors.initials: S
authors.lastname: Seité
authors.forename: Alain
authors.initials: A
authors.lastname: Colige
authors.forename: Christophe
authors.initials: C
authors.lastname: Deroanne
authors.forename: Charles
authors.initials: C
authors.lastname: Lambert
authors.forename: Pascale
authors.initials: P
authors.lastname: Piquemal-Vivenot
authors.forename: Christiane
authors.initials: C
authors.lastname: Montastier
authors.forename: Anny
authors.initials: A
authors.lastname: Fourtanier
authors.forename: Charles
authors.initials: C
authors.lastname: Lapière
authors.forename: Betty
authors.initials: B
authors.lastname: Nusgens
mesh_terms: D000328:Adult; D002081:Buttocks; D004307:Dose-Response Relationship, Radiation; D004890:Erythema / Q000209:etiology* / Q000378:metabolism; D005109:Extracellular Matrix / Q000528:radiation effects; D016326:Extracellular Matrix Proteins / Q000235:genetics / Q000378:metabolism / Q000528:radiation effects*; D015870:Gene Expression / Q000528:radiation effects; D020869:Gene Expression Profiling; D006801:Humans; D007375:Interleukin-1 / Q000032:analysis / Q000378:metabolism; D020778:Matrix Metalloproteinase 2 / Q000032:analysis / Q000378:metabolism; D008856:Microscopy, Fluorescence; D009113:Muramidase / Q000032:analysis / Q000378:metabolism; D010446:Peptide Fragments / Q000032:analysis / Q000378:metabolism; D017395:Plasminogen Activator Inhibitor 1 / Q000032:analysis / Q000378:metabolism; D011347:Procollagen / Q000032:analysis / Q000378:metabolism; D012333:RNA, Messenger / Q000032:analysis; D012867:Skin / Q000378:metabolism / Q000528:radiation effects*; D013472:Sunlight; D014466:Ultraviolet Rays; D000515:alpha 1-Antitrypsin / Q000032:analysis / Q000378:metabolism
chemical_list: D016326:Extracellular Matrix Proteins; D007375:Interleukin-1; D010446:Peptide Fragments; D017395:Plasminogen Activator Inhibitor 1; D011347:Procollagen; D012333:RNA, Messenger; D000515:alpha 1-Antitrypsin; C041876:procollagen Type III-N-terminal peptide; D009113:Muramidase; D020778:Matrix Metalloproteinase 2