Expressional changes in the intracellular melanogenesis pathways and their possible role in the pathogenesis of vitiligo.
BACKGROUND
Main pathway in human melanocytes through which signal from the melanocortin system reaches the melanogenesis enzymes is cAMP/PKA pathway and it is modulated by Wnt and MAPK pathways. In our previous study we established significant increase of melanocortin receptor expression in unaffected skin of vitiligo patients compared to healthy subjects.


OBJECTIVE
The aim of this study was to assess the gene expression profile of the intracellular signalling pathways linking melanocortin system with enzymes involved in melanogenesis.


METHODS
Using QRT-PCR method, mRNA expression levels of eight genes related to signal transduction from the melanocortin system to melanogenesis enzymes was measured in lesional and non-lesional skin of vitiligo patients and in the skin of healthy control subjects. Following genes were analyzed in the study: MITF, CREB1, p38, USF1, PIK3CB (PI3K), RPS6KB1, LEF1 and BCL2.


RESULTS
The mRNA levels of MITF, LEF1, p38, PIK3CB and RPS6KB1 were decreased in lesional skin of vitiligo patients compared to skin of healthy control subjects. We also found increased expression of USF1 and BCL2 in non-lesional skin of vitiligo patients compared to skin of healthy control subjects. mRNA levels of MITF and BCL2 were decreased in lesional skin of vitiligo patients compared to non-lesional skin of vitiligo patients.


CONCLUSIONS
Present study indicates increased expression of the genes of the intracellular melanogenesis pathway in the non-lesional skin of vitiligo patients. This finding suggests activation of melanogenesis pathway in the non-lesional skin of vitiligo.
Department of Dermatology and Venerology, Centre of Molecular and Clinical Medicine, University of Tartu, Tartu, Estonia.
Külli
K
Kingo
Eerik
E
Aunin
Maire
M
Karelson
Ranno
R
Rätsep
Helgi
H
Silm
Eero
E
Vasar
Sulev
S
Kõks
D000328:Adult; D000368:Aged; D005260:Female; D020869:Gene Expression Profiling; D006801:Humans; D008297:Male; D053486:Melanocortins / Q000235:genetics / Q000378:metabolism*; D008544:Melanocytes / Q000378:metabolism*; D008875:Middle Aged; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D044101:Receptors, Melanocortin / Q000235:genetics / Q000378:metabolism*; D012867:Skin / Q000378:metabolism*; D014820:Vitiligo / Q000235:genetics / Q000378:metabolism*
D053486:Melanocortins; D012333:RNA, Messenger; D044101:Receptors, Melanocortin