title: Narrow-band ultraviolet-B stimulates proliferation and migration of cultured melanocytes.
abstract: Narrow-band ultraviolet-B (UVB) radiation is an effective treatment for vitiligo vulgaris. However, the mechanisms of narrow-band UVB in inducing repigmentation of vitiligo lesions are not thoroughly clarified. The purpose of our study was to investigate the effects of narrow-band UVB irradiation on melanocyte proliferation and migration in vitro. Our results showed that the cell counts as well as [3H]thymidine uptake of melanocytes were significantly enhanced by narrow-band UVB-irradiated keratinocyte supernatants. In these supernatants, a significant increase in basic fibroblast growth factor (bFGF) and in endothelin-1 (ET-1) release was observed. bFGF is a natural mitogen for melanocytes, whereas ET-1 can stimulate DNA synthesis in melanocytes. This stimulatory effect of melanocyte proliferation by supernatants derived from narrow-band UVB-irradiated keratinocytes was significantly reduced by a selective endothelin-B (ET-B) receptor antagonist (BQ788), suggesting an essential role of ET-1 on melanocyte proliferation. Our results of time-lapse microphotography revealed a stimulatory effect of narrow-band UVB irradiation on melanocyte migration. Focal adhesion kinase (FAK) plays a pivotal role in cell migration. Phosphorylated FAK (p125(FAK)) expression on melanocyte was enhanced by narrow-band UVB irradiation. In this study, narrow-band UVB irradiation stimulated a significant increase in matrix metalloproteinase-2 (MMP-2) activity in melanocyte supernatants. Narrow-band UVB-irradiation-induced migration of melanocytes was significantly annihilated by the addition of p125(FAK) inhibitor (herbimycin-A) or MMP-2 inhibitor (GM6001). These results suggest that p125(FAK) and MMP-2 activity play important roles in narrow-band UVB-induced migration of melanocytes. Our results provide a theoretical basis for the effectiveness of narrow-band UVB irradiation in treating vitiligo.
authors.affiliation: School of Technology for Medical Sciences, College of Health Sciences, Kaohsiung Medical University, Kaohsiung, Taiwan.
authors.forename: Ching-Shuang
authors.initials: CS
authors.lastname: Wu
authors.forename: Chia-Li
authors.initials: CL
authors.lastname: Yu
authors.forename: Chieh-Shan
authors.initials: CS
authors.lastname: Wu
authors.forename: Cheng-Che E
authors.initials: CC
authors.lastname: Lan
authors.forename: Hsin-Su
authors.initials: HS
authors.lastname: Yu
mesh_terms: D002465:Cell Movement / Q000528:radiation effects; D049109:Cell Proliferation / Q000528:radiation effects; D002470:Cell Survival; D002478:Cells, Cultured; D004247:DNA / Q000378:metabolism; D004151:Dipeptides / Q000494:pharmacology; D019332:Endothelin-1 / Q000378:metabolism; D004797:Enzyme-Linked Immunosorbent Assay; D016222:Fibroblast Growth Factor 2 / Q000378:metabolism; D051417:Focal Adhesion Kinase 1; D051416:Focal Adhesion Protein-Tyrosine Kinases; D006801:Humans; D015603:Keratinocytes / Q000166:cytology / Q000378:metabolism; D020778:Matrix Metalloproteinase 2 / Q000096:biosynthesis / Q000378:metabolism; D020780:Matrix Metalloproteinase 9 / Q000096:biosynthesis; D008544:Melanocytes / Q000166:cytology* / Q000378:metabolism / Q000528:radiation effects*; D008856:Microscopy, Fluorescence; D009842:Oligopeptides / Q000494:pharmacology; D010766:Phosphorylation; D010880:Piperidines / Q000494:pharmacology; D011505:Protein-Tyrosine Kinases / Q000378:metabolism; D013997:Time Factors; D014466:Ultraviolet Rays
chemical_list: D004151:Dipeptides; D019332:Endothelin-1; C078131:N-(2(R)-2-(hydroxamidocarbonylmethyl)-4-methylpentanoyl)-L-tryptophan methylamide; D009842:Oligopeptides; D010880:Piperidines; D016222:Fibroblast Growth Factor 2; C086539:BQ 788; D004247:DNA; D011505:Protein-Tyrosine Kinases; D051417:Focal Adhesion Kinase 1; D051416:Focal Adhesion Protein-Tyrosine Kinases; C496050:PTK2 protein, human; D020778:Matrix Metalloproteinase 2; D020780:Matrix Metalloproteinase 9