Comparison of responses of melanocyte lineages from p75(+) and p75(-) human scalp-derived neural crest stem cells under phototherapy.

Phototherapy is an effective therapeutic option in the treatment of vitiligo; however, responses varied among the different types. The underlying mechanism has scarcely been investigated. To investigate and compare the effects of phototherapy on the mutation of melanocyte lineage differentiated from human scalp-derived neural crest stem cells (HS-NCSCs) with p75 neurotrophin receptor expression positive and p75 neurotrophin receptor expression negative group in vitro, the HS-NCSCs were isolated from fetal scalp tissue, which is identified by immunofluorescent staining. The p75(+) and p75(-) cells from HS-NCSCs were isolated by magnetic cell sorting, respectively. The embryonic neural crest stem cell biomarkers were detected by RT-PCR. Narrow-band UVB (NB-UVB) was used to irradiate the cells. Cell proliferation was evaluated by cell count. Tyrosinase, Tyrp1, and Tyrp2 gene expression were measured by quantitative RT-PCR. Tyrosinase and GRCR protein levels were investigated by Western blot analysis. The electrophoretic strip showed that Sox2, Oct4, Sox10, and Nestin of p75(+) HS-NCSCs were brighter than the p75(-) HS-NCSCs. After the same dose radiation with NB-UVB, the cell proliferation of p75(+) group showed less inhibitory rate compared with the p75(-) HS-NCSCs. The tyrosinase mRNA and protein expression of differentiated melanocytes increased significantly in the group of p75(+) HS-NCSCs compared with the p75(-) group. The melanocytic mutation of p75(+) HS-NCSCs increased significantly compared with the p75(-) HS-NCSCs under NB-UVB, which indicated there were more melanocyte precursors in the differentiated cells from p75(+) HS-NCSCs. This may provide new insights for the different repigmentation efficacy of segmental and non-segmental vitiligo.