Article

Protection of human reconstructed epidermis from UV by catalase overexpression

INSERM E 0217, University Victor Segalen Bordeaux 2, 146 rue Léo Saignat, 33076 Bordeaux cedex, France.
Cancer Gene Therapy (Impact Factor: 2.55). 03/2007; 14(2):174-86. DOI: 10.1038/sj.cgt.7701000
Source: PubMed

ABSTRACT Reactive oxygen species (ROS) generated by ultraviolet (UV) irradiation are counterbalanced by endogenous antioxidant systems. To test the hypothesis of a novel photoprotective approach, we irradiated epidermis reconstructed with normal human keratinocytes overexpressing sustainably lentivirus-mediated catalase (CAT), copper/zinc superoxide dismutase (CuZnSOD) or manganese superoxide dismutase (MnSOD) enzymes. We found that following UVB irradiation there was a marked decrease in sunburn cell formation, caspase-3 activation and p53 accumulation in human reconstructed epidermis overexpressing CAT. Moreover, UVA-induced hypertrophy and DNA oxidation (8-oxodeoxyguanosine) were decreased by CAT overexpression. These effects were not achieved by overexpression of CuZnSOD or MnSOD. In conclusion, vector-mediated CAT overexpression could be a promising photoprotective tool against deleterious effects of UV irradiation such skin cancer especially in monogenic/polygenic photosensitive disorders characterized by ROS accumulation.

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    • "Therefore, it may be thought that the antioxidant cell status could be critical in regulating cell behavior [20]. The cellular antioxidant defense mechanisms in the skin are both enzymatic and non-enzymatic [21–23]. Several enzymatic systems detoxifying ROS in the skin include catalase, glutathione peroxidase/reductase and superoxide dismutase. "
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    ABSTRACT: UVA affects epidermal cell physiology in a complex manner, but the harmful effects have been studied mainly in terms of DNA damage, mutagenesis and carcinogenesis. We investigated UVA effects on membrane integrity and antioxidant defense of dysplastic keratinocytes after one and two hours of irradiation, both immediately after exposure, and 24 h post-irradiation. To determine the UVA oxidative stress on cell membrane, lipid peroxidation was correlated with changes in fatty acid levels. Membrane permeability and integrity were assessed by propidium iodide staining and lactate dehydrogenase release. The effects on keratinocyte antioxidant protection were investigated in terms of catalase activity and expression. Lipid peroxidation increased in an exposure time-dependent manner. UVA exposure decreased the level of polyunsaturated fatty acids, which gradually returned to its initial value. Lactate dehydrogenase release showed a dramatic loss in membrane integrity after 2 h minimum of exposure. The cell ability to restore membrane permeability was noted at 24 h post-irradiation (for one hour exposure). Catalase activity decreased in an exposure time-dependent manner. UVA-irradiated dysplastic keratinocytes developed mechanisms leading to cell protection and survival, following a non-lethal exposure. The surviving cells gained an increased resistance to apoptosis, suggesting that their pre-malignant status harbors an abnormal ability to control their fate.
    International Journal of Molecular Sciences 12/2012; 13(12):16718-16736. DOI:10.3390/ijms131216718 · 2.86 Impact Factor
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    • "Although this enzyme plays a role in defending the organism against stress, it may not be essential to epidermal defense and development, as mice lacking catalase developed normally and responded to oxidant injury similar to wildtype animals (Ho et al. 2004). Nevertheless, its expression in the granular layer fits with a protective function against outside ultraviolet radiation, as reported with human keratinocytes in culture and in bioengineered skin (Rezvani et al. 2006, 2007), and also in bioengineered skin made with keratinocytes from patients with xeroderma pigmentosum (Rezvani et al. 2008). It is paradoxical that our EpSPs, which have very low levels and low activity of SOD and catalase, are more resistant to UV radiation than their progeny. "
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    ABSTRACT: Reactive oxygen species (ROS) and antioxidants are essential to maintain a redox balance within tissues and cells. Intracellular ROS regulate key cellular functions such as proliferation, differentiation and apoptosis through cellular signaling, and response to injury. The redox environment is particularly important for stem/progenitor cells, as their self-renewal and differentiation has been shown to be redox sensitive. However, not much is known about ROS and antioxidant protein function in freshly isolated keratinocytes, notably the different keratinocyte subpopulations. Immunostaining of neonatal cutaneous sections revealed that antioxidant enzymes [catalase, SOD2, gluthatione peroxidase-1 (GPx)] and ROS are localized predominantly to the epidermis. We isolated keratinocyte subpopulations and found lower levels of SOD2, catalase and GPx, as well as decreased SOD and catalase activity in an epidermal side population with stem cell-like characteristics (EpSPs) compared to more differentiated (Non-SP) keratinocytes. EpSPs also exhibited less mitochondrial area, fewer peroxisomes and produced lower levels of ROS than Non-SPs. Finally, EpSPs were more resistant to UV radiation than their progeny. Together, our data indicate ROS and antioxidant levels are decreased in stem-like EpSPs.
    Histochemie 02/2011; 135(3):293-304. DOI:10.1007/s00418-011-0786-2 · 2.93 Impact Factor
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    • "This includes non-enzymatic (e.g., a-tocopherol and vitamin C) as well as enzymatic antioxidants [e.g., SOD, catalase, glutathione peroxidase (GPx)]. An increase in antioxidant defense system whether non-enzymatic (Maalouf et al., 2002; Morley et al., 2003) or enzymatic (Rezvani et al., 2007, 2008) prevents the deleterious effects of UV-induced ROS on normal skin, such as photocarcinogenesis and photoaging. Melanin, particularly eumelanin, synthesized by melanocytes, is a scavenger of ROS (Bustamante et al., 1993). "
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    ABSTRACT: Exposure of cultured human melanocytes to ultraviolet radiation (UV) results in DNA damage. In melanoma, UV-signature mutations resulting from unrepaired photoproducts are rare, suggesting the possible involvement of oxidative DNA damage in melanocyte malignant transformation. Here we present data demonstrating immediate dose-dependent generation of hydrogen peroxide in UV-irradiated melanocytes, which correlated directly with a decrease in catalase activity. Pretreatment of melanocytes with alpha-melanocortin (alpha-MSH) reduced the UV-induced generation of 7,8-dihydro-8-oxyguanine (8-oxodG), a major form of oxidative DNA damage. Pretreatment with alpha-MSH also increased the protein levels of catalase and ferritin. The effect of alpha-MSH on 8-oxodG induction was mediated by activation of the melanocortin 1 receptor (MC1R), as it was absent in melanocytes expressing loss-of-function MC1R, and blocked by concomitant treatment with an analog of agouti signaling protein (ASIP), ASIP-YY. This study provides unequivocal evidence for induction of oxidative DNA damage by UV in human melanocytes and reduction of this damage by alpha-MSH. Our data unravel some mechanisms by which alpha-MSH protects melanocytes from oxidative DNA damage, which partially explain the strong association of loss-of-function MC1R with melanoma.
    Pigment Cell & Melanoma Research 08/2009; 22(6):809-18. DOI:10.1111/j.1755-148X.2009.00615.x · 5.64 Impact Factor
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