title: New insights in photoaging, UVA induced damage and skin types.
abstract: UVA radiation is the most prevalent component of solar UV radiation; it deeply penetrates into the skin and induces profound alterations of the dermal connective tissue. In recent years, the detrimental effects of UVA radiation were more precisely demonstrated at cellular and molecular levels, using adequate methods to identify biological targets of UVA radiation and the resulting cascade impairment of cell functions and tissue degradation. In particular gene expression studies recently revealed that UVA radiation induces modulation of several genes confirming the high sensitivity of dermal fibroblasts to UVA radiation. The major visible damaging effects of UVA radiation only appear after years of exposure: it has been clearly evidenced that they are responsible for more or less early signs of photoageing and photocarcinogenesis. UVA radiation appears to play a key role in pigmented changes occurring with age, the major sign of skin photoaging in Asians. Skin susceptibility to photoaging alterations also depends on constitutive pigmentation. The skin sensitivity to UV light has been demonstrated to be linked to skin color type.
authors.affiliation: L'Oreal Research and Innovation, Asnières, France.
authors.forename: Claire
authors.initials: C
authors.lastname: Battie
authors.forename: Setsuko
authors.initials: S
authors.lastname: Jitsukawa
authors.forename: Françoise
authors.initials: F
authors.lastname: Bernerd
authors.forename: Sandra
authors.initials: S
authors.lastname: Del Bino
authors.forename: Claire
authors.initials: C
authors.lastname: Marionnet
authors.forename: Michèle
authors.initials: M
authors.lastname: Verschoore
mesh_terms: D044466:Asian People; D004307:Dose-Response Relationship, Radiation; D006801:Humans; D007564:Japan; D020781:Matrix Metalloproteinase 1 / Q000096:biosynthesis / Q000528:radiation effects; D008954:Models, Biological; D012867:Skin / Q000378:metabolism / Q000473:pathology / Q000528:radiation effects; D015595:Skin Aging / Q000187:drug effects / Q000473:pathology / Q000528:radiation effects*; D012880:Skin Pigmentation / Q000528:radiation effects; D013473:Sunscreening Agents / Q000494:pharmacology; D014466:Ultraviolet Rays / Q000009:adverse effects*
chemical_list: D013473:Sunscreening Agents; C522360:MMP1 protein, human; D020781:Matrix Metalloproteinase 1
keywords: UVA; photoageing; photoprotection; skin sensitivity to UV