Melanocyte differentiation characterized by an increased melanogenesis, is stimulated by alpha-melanocyte-stimulating hormone through activation of the cAMP pathway. During this process, the expression of tyrosinase, the enzyme that controls melanin synthesis is upregulated. We previously showed that cAMP regulates transcription of the tyrosinase gene through a CATGTG motif that binds microphth...

BACKGROUND Acral lesions of vitiligo are usually resistant to conventional lines of treatment as well as surgical interventions. OBJECTIVE To clarify causes underlying resistance of acral lesions to pigmentation in vitiligo by studying some of the factors associated with mechanisms of repigmentation following photochemotherapy. METHODS The study included twenty patients with active vitiligo...

BACKGROUND Melanoma is the most aggressive and lethal form of skin cancer. Because of the increasing incidence and high lethality of melanoma, animal models for continuously observing melanoma formation and progression as well as for testing pharmacological agents are needed. METHODOLOGY AND PRINCIPAL FINDINGS Using the combinatorial Gal4-UAS system, we have developed a zebrafish transgenic l...

Mammalian pigmentation is driven by the intercellular transfer of pigment-containing melanosomes from the tips of melanocyte dendrites to surrounding keratinocytes. Tip accumulation of melanosomes requires myosin Va, because melanosomes concentrate in the center of melanocytes from myosin Va-null (dilute) mice. This distribution defect results in inefficient melanosome transfer and a dilution o...

The DOPA-reaction was used to identify tyrosinase in the nucleus and cytoplasm of the neural crest melanoblast of Taricha torosa, the California newt. In this urodele there is a nuclear DOPA-positive response during the normal embryonic development from the late blastula stage to the nucleus of the early melanocyte. During the gastrula stages, all nuclei of this newt are DOPA-positive. This pos...

Systematic work in the mouse and chicken has mapped out two neural crest-derived pathways of melanocyte precursor migration. With these in mind, this study reappraises the patterns of congenital pigmentary disorders in humans and identifies three recurrent patterns consistent across genetically different diseases. Only two of these are seen in diseases known to be melanocyte cell-autonomous. Th...

Alteration in the expression of growth factors is widely accepted as being one of several critical defects in the generation of the malignant cell. In the present study, 19 human metastatic melanoma cell lines were compared to 14 normal human foreskin melanocyte cell lines for the production of RNA transcripts specific for 11 different growth factors. Using the extremely sensitive technique of ...

Better understanding of tolerance and autoimmunity toward melanocyte-specific Ags is needed to develop effective treatment for vitiligo and malignant melanoma; yet, a systematic assessment of these mechanisms has been hampered by the difficulty in tracking autoreactive T cells. To address this issue, we have generated transgenic mice that express hen egg lysozyme as a melanocyte-specific neoant...