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.

Efficacy and Safety of Targeted High-Intensity Medium-Band (304-312 nm) Ultraviolet B Light in Pediatric Vitiligo.

BACKGROUND/OBJECTIVES: Phototherapy is a commonly used treatment for vitiligo that has demonstrated safety and efficacy. High-intensity targeted ultraviolet B (UVB) light (304-312 nm) delivered using a phototherapy device is a useful therapeutic option because it can induce repigmentation in a short time without global exposure to radiation, but information regarding this device in children is limited. METHODS: We performed a retrospective analysis of 95 patches of vitiligo in 27 children treated using a targeted phototherapy device. Phototherapy was administered twice a week. RESULTS: After the first 10 treatment sessions, 82 (86.3%) patches demonstrated some repigmentation and 36.8% achieved 50% or more repigmentation. After a mean of 20.4 treatment sessions, 86 patches (90%) demonstrated some repigmentation and 53.7% achieved 50% or more repigmentation. Responses varied depending on the anatomic location of the lesions. Better responses were usually observed on the face and trunk, whereas the extremities typically showed little response. Repigmentation was better in patients with active vitiligo than in those with stable vitiligo, with responses better with a disease duration of 1 year or less than in those with a duration of more than 1 year. There was no statistically significant difference in repigmentation between those with segmental and generalized vitiligo. The only short-term local side effect was mild erythema that required a decrease in dosage in six patients. CONCLUSION: Targeted high-intensity medium-band UVB phototherapy alone can produce clinical improvement in pediatric vitiligo and is well tolerated.

Comparison of high-intensity ultraviolet and NB-UVB on the maturation of melanocytes derived from hair follicle neural crest stem cells.

Both high-intensity ultraviolet and narrowband ultraviolet B (NB-UVB) are important therapeutic options for vitiligo management, but high-intensity ultraviolet is more effective than NB-UVB. However, the underlying mechanisms have not been well investigated. Herein, we compare the effects of high-intensity ultraviolet and NB-UVB on the pigmentation of melanocytes derived from hair follicle-derived neural crest stem cells (HF-NCSCs) in vitro and study the underlying mechanisms. The HF-NCSCs were isolated from mouse whisker follicles. After radiation with high-intensity ultraviolet and NB-UVB, respectively, the cell viability by the CCK-8 assay showed gradual inhibitory effects in a dose-dependent manner, which has no apparent difference between the two modalities. The mRNA for melanogenesis factors such as tyrosinase and tyrp1 of the differentiated melanocytes increased significantly with high-intensity ultraviolet compared to the same dose of NB-UVB exposure. Furthermore, the expression of Mc1r was significantly increased by high-intensity ultraviolet in contrast to NB-UVB at the dosage of 0.5 J. By and large, these data suggest that high-intensity ultraviolet exhibited greater efficiency on the maturation of the melanocyte lineage differentiated from HF-NCSCs compared to NB-UVB with the same dose, which was probably due to the stronger stimulatory action of Mc1r. This may provide new insights into the different efficacies of high-intensity ultraviolet and NB-UVB in the treatment of vitiligo repigmentation.

New insights into the characteristic skin microorganisms in different grades of acne and different acne sites.

Background: The increasing maturity of sequencing technology provides a convenient approach to studying the role of skin microorganisms in acne pathogenesis. However, there are still too few studies about the skin microbiota of Asian acne patients, especially a lack of detailed analysis of the characteristics of the skin microbiota in the different acne sites. Methods: In this study, a total of 34 college students were recruited and divided into the health, mild acne, and severe acne groups. The bacterial and fungal flora of samples were separately detected by 16S and 18S rRNA gene sequencing. The biomarkers of different acne grades and different acne sites [forehead, cheek, chin, torso (including chest and back)] were excavated. Results and Discussion: Our results indicated that there was no significant difference in species diversity between groups. The genera like Propionibacterium, Staphylococcus, Corynebacterium, and Malassezia, which have a relatively high abundance in the skin microbiota and were reported as the most acne-associated microbes, were no obvious differences between groups. On the contrary, the abundance of less reported Gram-negative bacteria (Pseudomonas, Ralstonia, and Pseudidiomarina) and Candida has a significant alteration. Compared with the health group and the mild group, in the severe group, the abundance of Pseudomonas and Ralstonia sharply reduced while that of Pseudidiomarina and Candida remarkably raised. Moreover, different acne sites have different numbers and types of biomarkers. Among the four acne sites, the cheek has the greatest number of biomarkers including Pseudomonas, Ralstonia, Pseudidiomarina, Malassezia, Saccharomyces, and Candida, while no biomarker was observed for the forehead. The network analysis indicated that there might be a competitive relationship between Pseudomonas and Propionibacterium. This study would provide a new insight and theoretical basis for precise and personalized acne microbial therapy.

NB-UVB Induces Melanocytic Differentiation of Human Hair Follicle Neural Crest Stem Cells.

BACKGROUND: Phototherapy is an important method to treat vitiligo. However, it is unclear how phototherapy affects melanocyte precursors and skin neural crest stem cells. OBJECTIVE: To investigate the underlying mechanisms of narrow-band ultraviolet B (NB-UVB) induced melanocyte lineage differentiated from human scalp-derived neural crest stem cells (HS-NCSCs). METHODS: HS-NCSCs were expanded from scalp hair follicles. The c-Kit-/CD57- HS-NCSCs were isolated by cell sorting. Different doses of NB-UVB were used to irradiate these HS-NCSCs. Cell ultrastructure was examined by transmission electron microscope. Melanocyte marker expression was analyzed by Quantitative RT-PCR and Western blot. Cell proliferation and migration were also evaluated. RESULTS: The c-Kit-/CD57- HS-NCSCs expressed embryonic NCSC biomarkers. NB-UVB at a dose of 100 mJ of NB-UVB had little effect on the cell proliferation of differentiated melanocytes from c-Kit-/CD57- HS-NCSCs, while 700 mJ inhibited cell proliferation significantly. The dendritic processes of differentiated melanocytes increased after radiation. The tyrosinase and Melanocortin 1 receptor (Mc1R) expression of differentiated melanocytes increased after NB-UVB exposure. The effect of NB-UVB on tyrosinase expression was modulated by signaling inhibitors H89 and PD98059 as well as Mc1R level in the cells. The migration ability of differentiated melanocytes was enhanced under 100 mJ exposure. CONCLUSION: These data demonstrate that NB-UVB facilitates melanocytic differentiation of the HS-NCSCs and enhances migration of these cells. Mc1R and cAMP pathway play a critical role in NB-UVB induced melanocytic differentiation.

CircMYC Regulates Glycolysis and Cell Proliferation in Melanoma.

Circular RNAs (cicRNAs) have been identified to play pivotal roles in several cancer types. However, functions of circRNA in malignant melanoma are poor defined. Our current study demonstrated that human circMYC was obviously upregulated in human melanoma tissue. Furthermore, circMYC promoted the proliferation of human melanoma cells and Mel-CV cells. The expression of circMYC can repress Mel-CV cell glycolysis and LDHA activities in the in vitro glycolysis and lactate production evaluations. circMYC directly bound to miR-1236 as a molecular sponge that targeting miR-1236 in Mel-CV cells via bioinformatics analysis, pull-down assay, and luciferase reporter assays. Our present study revealed that 3' UTR of LDHA acted as a target of miR-1236 using Mel-CV cells. Based on our findings, c-MYC-SRSF1 axis may regulate the production of circMYC. Overall, these results elucidate potential effects of circMYC in melanoma development and provide a promising biomarker for melanoma diagnosis.

The effects of NB-UVB on the hair follicle-derived neural crest stem cells differentiating into melanocyte lineage in vitro.

BACKGROUND: Narrow-band UVB (NB-UVB) is an effective therapeutic option in the treatment of vitiligo. Despite the apparent clinical efficacy, the underlying mechanism of how topical NB-UVB induces repigmentation in vitiligo has not been clearly elucidated. OBJECTIVES: To investigate the effects of NB-UVB on the maturation of melanocyte lineage differentiated from hair follicle-derived neural crest stem cells (HF-NCSCs) in vitro. METHODS: HF-NCSCs were isolated from mouse whisker follicles. The isolated cells were multipotent and expressed embryonic NCSC biomarkers. The effects of NB-UVB on development and differentiation of HF-NCSCs were evaluated. We assessed cell viability, melanogenesis and migration of melanocytes derived from HF-NCSCs after NB-UVB radiation. Tyrosinase, Tyrp1, Dct, Kit, Mc1R, Fzd4, NT3R, Ednra, EP1, TGFßR, Sox10, Mitf, Lef1 and Pax3 gene expression was measured by quantitative RT-PCR, while Tyrosinase, Sox10 and Mitf protein expression were measured by Western blot analysis. Cell migration was measured by Boyden chamber transwell assay. RESULTS: NB-UVB increased the expression of tyrosinase during melanocytic differentiation from mouse HF-NCSCs, however, NB-UVB inhibited proliferation of melanocytes derived from HF-NCSCs. Mechanistically, increased melanocyte maturation after NB-UVB treatment was resulted from increased expression of several key melanogenic factors, including Sox10, Kit and Mc1R, which play a critical role to promote tyrosinase expression. Furthermore, the migration of the HF-NCSCs-derived melanocytes was downregulated as NB-UVB doses increased. However, the migration of HF-NCSCs was upregulated under 0.4J NB-UVB radiation. CONCLUSIONS: Those data provide in vitro evidence demonstrating some direct effects of NB-UVB on pigmentation of melanocyte lineage differentiated from HF-NCSCs, and may provide a possible mechanism for the effect of NB-UVB in vitiligo.