PURPOSE The anatomical basis for iris color has long been a controversial issue in ophthalmology. Recent studies demonstrated that in Caucasians, blue-eyed, gray-eyed, and hazel-eyed individuals have comparable numbers of iris melanocytes. The present investigation was carried out to compare melanocyte numbers in the irides of Asian, African American, and Caucasian brown-eyed individuals. MET...

main transcription factors, Sox10 and Mifta (microphthalmiaassociated transcription factor), are already known to be involved in this process [Dutton et al., 2001; Elworthy et al., 2003]. Fate specification of melanocytes depends upon Sox10, and on Wnt signalling, to mediate regulation of Mitfa transcription. In contrast, the precise mechanism resulting in stable melanocyte differentiation rema...

Kit/SCF signaling and Mitf-dependent transcription are both essential for melanocyte development and pigmentation. To identify Mitf-dependent Kit transcriptional targets in primary melanocytes, microarray studies were undertaken. Among identified targets was BCL2, whose germline deletion produces melanocyte loss and which exhibited phenotypic synergy with Mitf in mice. BCL2's regulation by Mitf...

The aim of this study was to evaluate the effect of fluvastatin on the alpha-melanocyte-stimulating hormone-mediated increase in tyrosinase activity in the melanoma B16F10 cell line and to establish whether Akt and extracellular signal-regulated kinase (Erk) inhibition is involved in tyrosinase synthesis after fluvastatin administration. Fluvastatin modulates alpha-melanocyte-stimulating hormon...

The melanocortin receptors MC1 and MC3 are G protein-coupled receptors that have substantial structural similarities and bind melanocyte peptides but with different affinity profiles. We constructed a series of chimeric MC1/MC3 receptors to identify the epitopes that determine their selectivities for natural melanocyte peptides and synthetic analogues. The chimeric constructs were made by a pol...

We investigated whether or not the topographic regulation of melanocyte differentiation is determined by mesenchymal-epithelial interactions via fibroblast-derived factors. The melanocyte density in palmoplantar human skin (i.e., skin on the palms and the soles) is five times lower than that found in nonpalmoplantar sites. Palmoplantar fibroblasts significantly suppressed the growth and pigment...

The regulation of transcription and translation by specific cell types is essential to generate the cellular diversity that typifies complex multicellular organisms. Tagging and purification of ribosomal proteins has been shown to be an innovative and effective means of characterizing the ribosome bound transcriptome of highly specific cell populations in vivo. To test the feasibility of using ...

Melanocytes, highly differentiated neural crest-derived cells, are located in the basal layer of the epidermis, where they play a role in protecting against UV damage in the skin. Previous studies suggest that both growth hormone (GH) and the insulin-like growth factor I (GH/IGF-I) system may be important for melanocyte growth and function. We have therefore characterized the role of the GH/IGF...

Although melanocyte stimulating hormone (MSH) peptides are known to stimulate pigmentation in man, previous reports suggest that human melanocytes are relatively unresponsive to these peptides in vitro. This may be related to the conditions under which the melanocytes were cultured. Thus, we have re-investigated the in vitro effects of MSH peptides using human melanocytes cultured in the absenc...

main transcription factors, Sox10 and Mifta (microphthalmiaassociated transcription factor), are already known to be involved in this process [Dutton et al., 2001; Elworthy et al., 2003]. Fate specification of melanocytes depends upon Sox10, and on Wnt signalling, to mediate regulation of Mitfa transcription. In contrast, the precise mechanism resulting in stable melanocyte differentiation rema...