Disparate Antioxidant Enzyme Activities in Cultured Human Cutaneous Fibroblasts, Keratinocytes, and Melanocytes

Pro‐oxidant role of superoxide dismutase in ultraviolet‐A‐induced lipid peroxidation in cultured normal human skin fibroblasts

“…1). Since basal levels of the antioxidative defenses in cells not treated with DDC depend on the fibroblasts origin [13,14], data were normalized to that from corresponding cells untreated with DDC and used as reference for each donor. The values for these reference systems were assigned to be 100%.…”

Biological Effects Induced by Ultraviolet Radiation in Human Fibroblasts

“…Other authors, however, have found more antioxidant molecules in fibroblasts than in keratinocytes. Yohn et al (1991), using cells from different donors, found increased GSH-Px, SOD and catalase in fibroblasts compared to keratinocytes, and in keratinocytes compared to melanocytes (Huang et al, 2008).…”

Melanocyte Pygmentation – Friend or Foe on the Route to Melanoma

“…Then, hydrogen peroxide is converted by catalase (Cat) and peroxidases into water (Steenvoorden & van Henegouwen, 1997). Thioredoxin reductase together with its electron acceptor thioredoxin, thioredoxin peroxidases, glutathione reductase/glutathione coupled to glutathione peroxidase -present in small amounts in melanocytes (Yohn et al, 1991) are involved in the removal of H 2 O 2 deriving from enzymatic dismutation of superoxide anion (O 2-) catalyzed by SOD (Nordberg & Arner, 2001;Schallreuter & Wood, 2001). The high SOD/Cat ratio, can lead to an increased intracellular production of hydrogen peroxide, thus is considered as a parameter of the cells susceptibility to external oxidative stress (Maresca et al, 2006).…”

“…Low levels of Cat activity were previously observed in different cutaneous experimental models (which contained lightly pigmented melanocytes) and they were always associated with a stress-prone status (Maresca et al, 2006;Bessou-Touya et al, 1998;Gramatico et al, 1998;Picardo et al, 1999, Kadekaro et al, 2003Kvam E & Dahle, 2004). In melanocytes, the role of Cat is critical because it is the first enzyme devoted to the neutralization of H 2 O 2 (Yohn et al, 1991) a byproduct of the melanogenic pathway (Nappi & Vass, 1996). Cat oxidative damage is detrimental, because when damaged it recovers slowly (Shindo et al, 1994;Shindo & Hashimoto, 1997).…”