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UV-A irradiation induces a decrease in the mitochondrial respiratory activity of human NCTC 2544 keratinocytes.

M Djavaheri-Mergny·C Marsac·C Mazière·R Santus·L Michel·L Dubertret·J C Mazière
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Abstract

UV-A irradiation caused a dose-dependent decrease in cellular oxygen consumption (56%) and ATP content (65%) in human NCTC 2544 keratinocytes, one hour after treatment. This effect was partially reversed by maintaining the irradiated cells in normal culture conditions for 24 h. Using malate/glutamate or succinate as substrates for mitochondrial electron transport, the oxygen uptake of digitonin-permeabilised cells was greatly inhibited following UV-A exposure. These results strongly suggest that UV-A irradiation affects the state 3 respiration of the mitochondria. However, under identical conditions, UV-A exposure did not reduce the mitochondrial transmembrane potential. The antioxidant, vitamin E inhibited UV-A-induced lipid peroxidation, but did not significantly prevent the UV-A-mediated changes in cellular respiration nor the decrease in ATP content, suggesting that these effects were not the result of UV-A dependent lipid peroxidation. UV-A irradiation also led to an increase in MnSOD gene expression 24 hours after treatment, indicating that the mitochondrial protection system was enhanced in response to UV-A treatment. These findings provide evidence that impairment of mitochondrial respiratory activity is one of the early results of UV-A irradiation for light doses much lower than the minimal erythemal dose.

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Adenosine TriphosphateAntioxidantsCell LineCell RespirationHumansIntracellular FluidIntracellular MembranesKeratinocytesMembrane PotentialsMitochondriaSuperoxide DismutaseUltraviolet RaysJournal ArticleResearch Support, Non-U.S. Gov't

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M Djavaheri-Mergny, C Marsac, C Mazière, R Santus, L Michel, L Dubertret, J C Mazière. 2001. UV-A irradiation induces a decrease in the mitochondrial respiratory activity of human NCTC 2544 keratinocytes.. https://doi.org/10.1080/10715760100300481

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