TY - CHAP
T1 - Correlation between melanogenic and catalase activity in in vitro human melanocytes
T2 - A synergic strategy against oxidative stress
AU - Maresca, Vittoria
AU - Flori, Enrica
AU - Briganti, Stefania
AU - Mastrofrancesco, Arianna
AU - Fabbri, Claudia
AU - Mileo, Anna M.
AU - Paggi, Marco G.
AU - Picardo, Mauro
PY - 2008/4
Y1 - 2008/4
N2 - UV-induced DNA damage can lead to melanoma, the most dangerous form of skin cancer. Understanding the mechanisms employed by melanocytes to protect against UV is therefore a key issue. In melanocytes, catalase is the main enzyme responsible for degrading hydrogen peroxide and we have previously shown that that low basal levels of catalase activity are associated with the light phototype in in vitro and ex vivo models. Here we investigate the possible correlation between its activity and melanogenesis in primary cultures of human melanocytes. We show that while the total melanin concentration is directly correlated to the level of pigmentation, the more the degree of pigmentation increased, the lower the proportion of pheomelanin present. Moreover, in human melanocytes in vitro, catalase-specific mRNA, protein and enzymatic activity were all directly correlated with total cellular melanin content. We also observed that immediately after a peroxidative treatment, the increase in reactive oxygen species was inversely associated with pigmentation level. Darkly pigmented melanocytes therefore possess two protective strategies represented by melanins and catalase activity that are likely to act synergistically to counteract the deleterious effects of UV radiation. By contrast, lightly pigmented melanocytes possess lower levels of melanogenic and catalase activity and are therefore more susceptible to accumulate damage after UV exposition.
AB - UV-induced DNA damage can lead to melanoma, the most dangerous form of skin cancer. Understanding the mechanisms employed by melanocytes to protect against UV is therefore a key issue. In melanocytes, catalase is the main enzyme responsible for degrading hydrogen peroxide and we have previously shown that that low basal levels of catalase activity are associated with the light phototype in in vitro and ex vivo models. Here we investigate the possible correlation between its activity and melanogenesis in primary cultures of human melanocytes. We show that while the total melanin concentration is directly correlated to the level of pigmentation, the more the degree of pigmentation increased, the lower the proportion of pheomelanin present. Moreover, in human melanocytes in vitro, catalase-specific mRNA, protein and enzymatic activity were all directly correlated with total cellular melanin content. We also observed that immediately after a peroxidative treatment, the increase in reactive oxygen species was inversely associated with pigmentation level. Darkly pigmented melanocytes therefore possess two protective strategies represented by melanins and catalase activity that are likely to act synergistically to counteract the deleterious effects of UV radiation. By contrast, lightly pigmented melanocytes possess lower levels of melanogenic and catalase activity and are therefore more susceptible to accumulate damage after UV exposition.
KW - Catalase
KW - Hydrogen peroxide
KW - Melanin
KW - Melanogenesis
KW - Oxidative stress
UR - http://www.scopus.com/inward/record.url?scp=42249112484&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=42249112484&partnerID=8YFLogxK
U2 - 10.1111/j.1755-148X.2007.00432.x
DO - 10.1111/j.1755-148X.2007.00432.x
M3 - Chapter
C2 - 18426413
AN - SCOPUS:42249112484
VL - 21
SP - 200
EP - 205
BT - Pigment Cell and Melanoma Research
ER -