Algae extract-mediated stimulation and protection of proteasome activity within human keratinocytes exposed to UVA and UVB irradiation.
Sun exposure is the major environmental influence for epidermal cells; the harmful effect of UV radiation on skin is related to the generation of reactive oxygen species that alter cellular components including proteins. It is now well established that the proteasome is responsible for the degradation of most of oxidized proteins and that impairment of proteasome function is a hallmark of cellular aging. In a previous study, we investigated the effects of UV irradiation on proteasomes in human keratinocyte cultures and showed that all three peptidase activities were decreased 24 h after irradiation of the cells. Increased levels of oxidatively modified proteins were observed in irradiated cells and were found to act as endogenous inhibitors of the proteasome. We report here on the stimulating and protective effects of an algae extract, prepared from Phaeodactylum tricornutum, on proteasome peptidase activities of human keratinocytes exposed to UVA and UVB irradiation. In addition, preserving proteasome function resulted in lowering the extent of the irradiation-induced protein oxidative damage, opening up new strategies for protection of epidermal cells against the detrimental effects of UV irradiation.
Laboratoire de Biologie et Biochimie Cellulaire du Vieillissement, Université Paris 7-Denis Diderot, Paris, France.
Anne-Laure
AL
Bulteau
Marielle
M
Moreau
Alex
A
Saunois
Carine
C
Nizard
Bertrand
B
Friguet
D018929:Cell Culture Techniques; D002470:Cell Survival / Q000187:drug effects / Q000528:radiation effects; D056890:Eukaryota; D006801:Humans; D015603:Keratinocytes / Q000166:cytology / Q000187:drug effects / Q000201:enzymology*; D007700:Kinetics; D046988:Proteasome Endopeptidase Complex / Q000187:drug effects / Q000378:metabolism* / Q000528:radiation effects; D014020:Tissue Extracts / Q000494:pharmacology*; D014466:Ultraviolet Rays
D014020:Tissue Extracts; D046988:Proteasome Endopeptidase Complex