TY - JOUR
T1 - Diversity of pigmentation in cultured human melanocytes is due to differences in the type as well as quantity of melanin
AU - Wakamatsu, Kazumasa
AU - Kavanagh, Renny
AU - Kadekaro, Ana L.
AU - Terzieva, Silva
AU - Sturm, Richard A.
AU - Leachman, Sancy
AU - Abdel-Malek, Zalfa
AU - Ito, Shosuke
PY - 2006/4
Y1 - 2006/4
N2 - Cultured human melanocytes differ tremendously in visual pigmentation, and recapitulate the pigmentary phenotype of the donor's skin. This diversity arises from variation in type as well as quantity of melanin produced. Here, we measured contents of eumelanin (EM) and pheomelanin (PM) in 60 primary human melanocyte cultures (51 neonatal and nine adults), and correlated some of these values with the respective activity and protein levels of tyrosinase, and the melanocortin-1 receptor (MC1R) genotype. Melanocytes were classified into four phenotypes (L, L+, D, D+) as depicted by visual pigmentation using light microscopy, and by the pigmentary phenotype of the donor's skin. There were large differences in total melanin (TM) and EM, which increased progressively for L, L+, D and D+ melanocytes. TM content, the sum of EM and PM, showed a good correlation with TM measured spectrophotometrically, and with the activity and protein levels of tyrosinase. Log EM/PM ratio did not correlate with MC1R genotype. We conclude that: (i) EM consistently correlates with the visual phenotype; (ii) lighter melanocytes tend to be more pheomelanic in composition than darker melanocytes; (iii) in adult melanocyte cultures, EM correlates with the ethnic background of the donors (African-American > Indian > Caucasian); and (iv) MC1R loss-of-function mutations do not necessarily alter the phenotype of cultured melanocytes.
AB - Cultured human melanocytes differ tremendously in visual pigmentation, and recapitulate the pigmentary phenotype of the donor's skin. This diversity arises from variation in type as well as quantity of melanin produced. Here, we measured contents of eumelanin (EM) and pheomelanin (PM) in 60 primary human melanocyte cultures (51 neonatal and nine adults), and correlated some of these values with the respective activity and protein levels of tyrosinase, and the melanocortin-1 receptor (MC1R) genotype. Melanocytes were classified into four phenotypes (L, L+, D, D+) as depicted by visual pigmentation using light microscopy, and by the pigmentary phenotype of the donor's skin. There were large differences in total melanin (TM) and EM, which increased progressively for L, L+, D and D+ melanocytes. TM content, the sum of EM and PM, showed a good correlation with TM measured spectrophotometrically, and with the activity and protein levels of tyrosinase. Log EM/PM ratio did not correlate with MC1R genotype. We conclude that: (i) EM consistently correlates with the visual phenotype; (ii) lighter melanocytes tend to be more pheomelanic in composition than darker melanocytes; (iii) in adult melanocyte cultures, EM correlates with the ethnic background of the donors (African-American > Indian > Caucasian); and (iv) MC1R loss-of-function mutations do not necessarily alter the phenotype of cultured melanocytes.
KW - Eumelanin
KW - Melanocortin-1 receptor
KW - Melanocytes
KW - Pheomelanin
KW - Tyrosinase
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U2 - 10.1111/j.1600-0749.2006.00293.x
DO - 10.1111/j.1600-0749.2006.00293.x
M3 - Article
C2 - 16524431
AN - SCOPUS:33644847858
SN - 0893-5785
VL - 19
SP - 154
EP - 162
JO - Pigment Cell Research
JF - Pigment Cell Research
IS - 2
ER -