Abnormal metabolism in melanocytes participates in the activation of dendritic cell in halo nevus.

A comprehensive analysis of spatial transcriptomics was carried out to better understand the progress of halo nevus. We found that halo nevus was characterized by overactive immune responses, triggered by chemokines and dendritic cells (DCs), T cells, and macrophages. Consequently, we observed abnormal cell death, such as apoptosis and disulfidptosis in halo nevus, some were closely related to immunity. Interestingly, we identified aberrant metabolites such as uridine diphosphate glucose (UDP-G) within the halo nevus. UDP-G, accompanied by the infiltration of DCs and T cells, exhibited correlations with certain forms of cell death. Subsequent experiments confirmed that UDP-G was increased in vitiligo serum and could activate DCs. We also confirmed that oxidative response is an inducer of UDP-G. In summary, the immune response in halo nevus, including DC activation, was accompanied by abnormal cell death and metabolites. Especially, melanocyte-derived UDP-G may play a crucial role in DC activation.

Macrophage migration inhibitory factor mediates skin aging via CD74: Insights from single-cell and bulk RNA sequencing data.

Cell-cell communication is crucial for regulating signaling and cellular function. However, the precise cellular and molecular changes remain poorly understood in skin aging. Based on single-cell and bulk RNA data, we explored the role of cell-cell ligand-receptor interaction in skin aging. We found that the macrophage migration inhibitory factor (MIF)/CD74 ligand-receptor complex was significantly upregulatedin aged skin, showing the predominant paracrine effect of keratinocytes on fibroblasts. Enrichment analysis and in vitro experiment revealed a close association of the activation of the MIF/CD74 with inflammatory pathways and immune response. Mechanistically, MIF/CD74 could significantly inhibit PPARγ protein, which thus significantly increased the degree of fibroblast senescence, and significantly up-regulated the expression of senescence-associated secretory phenotype (SASP) factors and FOS gene. Therefore, our study reveals that MIF/CD74 inhibits the activation of the PPAR signaling pathway, subsequently inducing the production of SASP factors and the upregulation of FOS expression, ultimately accelerating fibroblast senescence.

UVB promotes melanogenesis by regulating METTL3.

Ultraviolet (UV) radiation is the primary exogenous inducer of skin pigmentation, although the mechanism has not been fully elucidated. N6-methyladenosine (m6 A) modification is one of the key epigenetic form of gene regulation that affects multiple biological processes. The aim of this study was to explore the role and underlying mechanisms of m6 A modification in UVB-induced melanogenesis. Low-dose UVB increased global m6 A modification in melanocytes (MCs) and MNT1 melanoma cell line. The GEPIA database predicted that methyltransferase METTL3 is positively correlated with the melanogenic transcription factor MITF in the sun-exposed skin tissues. After METTL3 respectively overexpressed and knocked down in the MNT1, the melanin content and melanogenesis-related genes were significantly upregulated after overexpression of METTL3, especially with UVB irradiation, and downregulated after METTL3 knockdown. METTL3 levels were also higher in melanocytic nevi with high melanin content. METTL3 overexpression and knockdown also altered the protein level of YAP1. SRAMP analysis predicted four high-potential m6 A modification sites on YAP1 mRNA, of which three were confirmed by methylated RNA immunoprecipitation. Inhibition of YAP1 expression can partially reverse melanogenesis induced by overexpression of METTL3. In conclusion, UVB irradiation promotes global m6 A modification in MCs and upregulates METTL3, which increases the expression level of YAP1 through m6 A modification, thereby activating the co-transcription factor TEAD1 and promoting melanogenesis.

Characteristics and pathogenesis of Koebner phenomenon.

The Koebner phenomenon, also known as isomorphic reaction, refers to the development of secondary lesions with the same clinical manifestations and histopathological characteristics as the primary lesions in normal skin after trauma or other stimuli. The triggering factors of Koebner phenomenon include physical trauma, chemical stimulation, mechanical stress, iatrogenic stimulation and pathogenic infection. Vitiligo, psoriasis and lichen planus are considered true Koebner phenomenon. Recent studies have shown that immunological disorders, oxidative stress, defective melanocyte adhesion and growth factor deficiency are the main pathological mechanisms of vitiligo Koebner phenomenon. In psoriasis, triggers may drive skin inflammation to induce a psoriatic phenotype through multiple signalling pathways and thereby cause Koebner phenomenon in susceptible individuals. Significantly, keratinocytes mediate the occurrence of Koebner phenomenon in psoriasis through mechano-induced signalling pathways after sensing mechanical signals and explains the high frequency of psoriasis lesions on the extensor side of the elbow and knee joints. On the contrary, TRPA1-driven mechano-transduction, autoimmunity and actinic damage are the underlying mechanisms of Koebner phenomenon in lichen planus. In this review, we have summarized the current understanding of the characteristics and pathogenesis of Koebner phenomenon.

Melatonin reduces melanogenesis by inhibiting the paracrine effects of keratinocytes.

Keratinocytes regulate melanogenesis in a paracrine manner. Previous studies have shown that melatonin can directly inhibit melanin production in the melanocytes. However, it is unclear whether melatonin can also indirectly regulate melanogenesis through the keratinocytes. In this study, we explored the role of melatonin in regulating keratinocyte-mediated melanogenesis using reconstructed human epidermis (RHE). Melatonin showed an inhibitory effect on melanin synthesis in this model. Furthermore, the conditioned media from melatonin-treated HaCaT cells downregulated melanogenesis-related genes, including MITF, TYR, TYRP1, DCT and RAB27A in the pigment MNT1 cells, and decreased levels of phosphorylated ERK, JNK and p38. RNA sequencing further showed that mitochondrial functions and oxidative stress pathway in the MNT1 cells were inhibited by the conditioned medium from melatonin-treated HaCaT cells. Furthermore, melatonin reduced the secretion of ET-1 and PTGS2 from HaCaT cells by inhibiting the JAK2/STAT3 signalling pathway. In conclusion, melatonin downregulates the paracrine factors ET-1 and PTGS2 in the keratinocytes by inhibiting the JAK2/STAT3 pathway, which reduces melanin production in pigment cells. Thus, melatonin has a potential therapeutic effect on skin pigmentation disorders.

Disease Awareness and Treatment Preferences in Vitiligo: A Cross-sectional Study in China.

In China, there is a lack of data regarding the awareness and treatment preferences among patients with vitiligo and their families. To address this gap, a cross-sectional questionnaire-based study was conducted to investigate disease awareness and treatment preferences in Chinese patients with vitiligo. The study also evaluated willingness to pay, using 2 standardized items, and assessed quality of life, using the Dermatology Life Quality Index (DLQI) score. Data from 307 patients with vitiligo (59.3% women, mean age 28.98 years, range 2-73 years) were analysed. Of these patients, 44.7% had insufficient knowledge of vitiligo, particularly those from rural areas or with low levels of education. Mean DLQI total score was 4.86 (5.24 for women and 4.30 for men). Among the most accepted treatments were topical drugs, phototherapy, and systemic therapy. Patients were relatively conservative about the duration and cost of treatment, with only 27.7% willing to pay more than 10,000 Chinese yuan renminbi (CNY) for complete disease remission. High level of education, high income, skin lesions in specific areas, and skin transplantation therapy predicted higher willingness to pay. Insufficient knowledge was associated with a higher burden of disease. In order to reduce the disease burden and improve treatment adherence it is crucial to enhance disease awareness and take into account patient preferences.

Selaginellin Inhibits Melanogenesis via the MAPK Signaling Pathway.

Hyperpigmented skin diseases such as melasma, freckles, and melanosis usually mar the appearance of patients. Traditional herbal medicines are highly accepted in inhibiting skin pigmentation, with advantages of high efficiency, low cost, and low side effects. Selaginellin (SEL), one of the active compounds of selaginella, has been proved to be exhibit antineoplastic, antioxidant, antisenescence, and antiapoptosis activities. In this study, we found that SEL can inhibit melanogenesis in vitro and in vivo. A mechanism study found that SEL inhibits melanogenesis through inhibiting the mitogen-activated protein kinase (MAPK) signaling pathway, then down-regulating the expression of microphthalmia-associated transcription factor (MITF) and downstream genes tyrosinase (TYR) and tyrosinase-related protein 2 (TYRP2). UVB-activated paracrine function of fibroblasts and keratinocytes promotes melanogenesis of melanocytes. Interestingly, SEL antagonizes UVB-activated paracrine function of fibroblasts and keratinocytes. These findings indicate that SEL can be a potential whitening compound to inhibit melanogenesis.

SIRT1 Regulates N6 -Methyladenosine RNA Modification in Hepatocarcinogenesis by Inducing RANBP2-Dependent FTO SUMOylation.

BACKGROUND AND AIMS: Hepatocellular carcinoma (HCC) is associated with high malignancy rates. Recently, a known deacetylase silent information regulator 1 (SIRT1) was discovered in HCC, and its presence is positively correlated with malignancy and metastasis. N6 -methyladenosine (m6 A) is the most prominent modification, but the exact mechanisms on how SIRT1 regulates m6 A modification to induce hepatocarcinogenesis remain unclear. APPROACH AND RESULTS: Here we demonstrate that SIRT1 exerts an oncogenic role by down-regulating fat mass and obesity-associated protein (FTO), which is an m6 A demethylase. A crucial component of small ubiquitin-related modifiers (SUMOs) E3 ligase, RANBP2, is activated by SIRT1, and it is indispensable for FTO SUMOylation at Lysine (K)-216 site that promotes FTO degradation. Moreover, Guanine nucleotide-binding protein G (o) subunit alpha (GNAO1) is identified as m6 A downstream targets of FTO and tumor suppressor in HCC, and depletion of FTO by SIRT1 improves m6 A+ GNAO1 and down-regulates its mRNA expression. CONCLUSIONS: We demonstrate an important mechanism whereby SIRT1 destabilizes FTO, steering the m6 A+ of downstream molecules and subsequent mRNA expression in HCC tumorigenesis. Our findings uncover a target of SIRT1 for therapeutic agents to treat HCC.

Cistanche deserticola polysaccharide induces melanogenesis in melanocytes and reduces oxidative stress via activating NRF2/HO-1 pathway.

As a main part of pigmentation disorders, skin depigmentation diseases such as vitiligo and achromic naevus are very common and get more attention now. The pathogenesis of depigmentation includes melanocyte dysfunction and loss, which are possibly caused by heredity, autoimmunity and oxidative stress. Among them, oxidative stress plays a key role; however, few clinical treatments can deal with oxidative stress. As reported, Cistanche deserticola polysaccharide (CDP) is an effective antioxidant; based on that, we evaluated its role in melanocyte and further revealed the mechanisms. In this study, we found that CDP could promote melanogenesis in human epidermal melanocytes (HEMs) and mouse melanoma B16F10 cells, it also induced pigmentation in zebrafish. Furthermore, CDP could activate mitogen-activated protein kinase (MAPK) signal pathway, then up-regulated the expression of microphthalmia-associated transcription factor (MITF) and downstream genes TYR, TRP1, TRP2 and RAB27A. Otherwise, we found that CDP could attenuate H2 O2 -induced cytotoxicity and apoptosis in melanocytes. Further evidence revealed that CDP could enhance NRF2/HO-1 antioxidant pathway and scavenge intracellular ROS. In summary, CDP can promote melanogenesis and prevent melanocytes from oxidative stress injury, suggesting that CDP helps maintain the normal status of melanocytes. Thus, CDP may be a novel drug for the treatment of depigmentation diseases.

Ozone therapy promotes the differentiation of basal keratinocytes via increasing Tp63-mediated transcription of KRT10 to improve psoriasis.

Psoriasis is a chronic immune-mediated inflammatory dermatosis. Recently, ozone therapy has been applicated to psoriasis treatment; however, the mechanism by which ozone therapy improves psoriasis remains unclear. The excessive proliferation and the differentiation of basal keratinocytes have been considered critical issues during pathological psoriasis process, in which keratin 6 (KRT6) and KRT10 might be involved. In the present study, KRT6, IL-17 and IL-22 protein within psoriasis lesions was decreased, while KRT10 and Tp63 protein in psoriasis lesions was increased by ozone treatment in both patient and IMQ mice psoriatic tissues. In the meantime, ozone treatment down-regulated KRT6 mRNA and protein expression while up-regulated KRT10 mRNA and protein expression within IL-22 treated primary KCs; the cell viability of KCs was suppressed by ozone treatment. Moreover, Tp63 bound to KRT10 promoter region to activate its transcription in basal keratinocytes; the promotive effects of ozone on Tp63 and KRT10 were significantly reversed by Tp63 silence. Both TP63 and KRT10 mRNA expression were significantly increased by ozone treatment in psoriasis lesions; there was a positive correlation between Tp63 and KRT10 expression within tissue samples, suggesting that ozone induces the expression of Tp63 to enhance the expression of KRT10 and the differentiation of keratinocytes, therefore improving the psoriasis. In conclusion, the application of ozonated oil could be an efficient and safe treatment for psoriasis; ozone promotes the differentiation of keratinocytes via increasing Tp63-mediated transcription of KRT10, therefore improving psoriasis.

Ubiquitin ligase CHAF1B induces cisplatin resistance in lung adenocarcinoma by promoting NCOR2 degradation.

BACKGROUND: Lung cancer is the most common malignant tumor in the world. The Whole-proteome microarray showed that ubiquitin ligase chromatin assembly factor 1 subunit B (CHAF1B) expression in A549/DDP cells is higher than in A549 cells. Our study explored the molecular mechanism of CHAF1B affecting cisplatin resistance in lung adenocarcinoma (LUAD). METHODS: Proteome microarray quantify the differentially expressed proteins between LUAD cell line A549 and its cisplatin-resistant strain A549/DDP. Quantitative real-time quantitative polymerase chain reaction (qRT-PCR) and Western blot (WB) confirmed the CHAF1B expression. Public databases analyzed the prognosis of LUAD patients with varied LUAD expression followed by the substrates prediction of CHAF1B. Public databases showed that nuclear receptor corepressor 2 (NCOR2) may be substrates of CHAF1B. WB detected that CHAF1B expression affected the expression of NCOR2. Cell and animal experiments and clinical data detected function and integrating mechanism of CHAF1B compounds. RESULTS: Proteome chips results indicated that CHAF1B, PPP1R13L, and CDC20 was higher than A549 in A549/DDP. Public databases showed that high expression of CHAF1B, PPP1R13L, and CDC20 was negatively correlated with prognosis in LUAD patients. PCR and WB results indicated higher CHAF1B expression in A549/DDP cells than that in A549 cells. NCOR2 and PPP5C were confirmed to be substrates of CHAF1B. CHAF1B knockdown significantly increased the sensitivity of cisplatin in A549/DDP cells and the upregulated NCOR2 expression. CHAF1B and NCOR2 are interacting proteins and the position of interaction between CHAF1B and NCOR2 was mainly in the nucleus. CHAF1B promotes ubiquitination degradation of NCOR2. Cells and animal experiments showed that under the action of cisplatin, after knockdown of CHAF1B and NCOR2 in A549/DDP group compared with CHAF1B knockdown alone, the cell proliferation and migratory ability increased and apoptotic rate decreased, and the growth rate and size of transplanted tumor increased significantly. Immunohistochemistry suggested that Ki-67 increased, while apoptosis-related indicators caspase-3 decreased significantly. Clinical data showed that patients with high expression of CHAF1B are more susceptible to cisplatin resistance. CONCLUSION: Ubiquitin ligase CAHF1B can induce cisplatin resistance in LUAD by promoting the ubiquitination degradation of NCOR2.

Ganoderma lucidum polysaccharide reduces melanogenesis by inhibiting the paracrine effects of keratinocytes and fibroblasts via IL-6/STAT3/FGF2 pathway.

Our previous study found that Ganoderma lucidum polysaccharide (GLP), bioactive ingredients from Ganoderma lucidum, protected fibroblasts from photoaging. However, whether GLP can affect melanogenesis in melanocytes through regulating paracrine mediators that secreted by keratinocytes and fibroblasts is unclear. We aimed to investigate the efficacy and mechanisms of action of GLP in melanogenesis by regulating paracrine effects of keratinocytes and fibroblasts. The effect of GLP on cell viability affected by GLP was measured by the 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay. After an immortal keratinocyte line (HaCaT) and primary fibroblasts (FB) were treated with GLP, the supernatants of HaCaT and FB cells were collected and cocultured with an immortalized melanocyte line (PIG1). The expression levels of melanogenesis-associated genes in PIG1 cells were measured by quantitative real-time polymerase chain reaction (qRT-PCR) and western blot analysis. Furthermore, FRS-2, ERK, JNK, and p38 phosphorylation levels were measured. Then, major melanogenic paracrine mediators in HaCaT and FB cells treated with GLP were evaluated by qRT-PCR and enzyme-linked immunosorbent assay (ELISA). In addition, the expression of IL-6 and STAT3 was examined in HaCaT and FB cells. GLP was not cytotoxic to HaCaT and FB cells. The supernatants of GLP-treated HaCaT and FB cells downregulated the expression levels of MITF, TYR, TYRP1, TYRP2, RAB27A, and FSCN1 genes and inhibited the phosphorylation of FRS-2, ERK, JNK, and p38 in PIG1 cells. GLP also decreased FGF2 secretion in HaCaT and FB cells. Moreover, GLP reduced IL-6 expression and STAT3 phosphorylation in HaCaT and FB cells. GLP reduced melanogenesis in melanocytes by inhibiting the paracrine effects of keratinocytes and fibroblasts via IL-6/STAT3/FGF2 pathway.

Ganoderma lucidum polysaccharide inhibits UVB-induced melanogenesis by antagonizing cAMP/PKA and ROS/MAPK signaling pathways.

Ultraviolet (UV)-induced pigmentation is very common in clinical practice, but the current treatments are rarely effective, accompanied by some side effects. Ganoderma lucidum polysaccharide (GLP) is a natural antioxidant with no toxic side effects, which can antagonize UVB-induced fibroblast photo aging. The study aims to explore the role of GLP in inhibiting UVB-induced melanogenesis and its possible mechanism. The expression of melanogenesis genes such as microphthalmia-associated transcription factor (MITF), tyrosine (TYR), tyrosinase related protein 1 (TYRP1), tyrosinase related protein 2 (TYRP2), ras-related protein Rab-27A (Rab27A), and Myosin shows an upward trend after exposure of B16F10 and PIG1 cells to UVB irradiation, but GLP can downregulate the expression of genes related to UVB-induced melanogenesis. GLP can inhibit UVB-activated protein kinase A (PKA) and mitogen-activated protein kinase (MAPK) signaling pathways. Besides, GLP protects mitochondria from UVB damage and inhibits reactive oxygen species (ROS) production. Also, UVB-induced cyclic adenosine monophosphate (cAMP) can be inhibited. It has been found in the experiments of UVB-induced skin pigmentation in zebrafish that GLP is capable of inhibiting UVB-induced skin pigmentation. Meanwhile, it can greatly relieve erythema reaction in guinea pig skin caused by high-dosage UVB irradiation. In conclusion, this study shows that GLP can inhibit UVB-induced melanogenesis by antagonizing cAMP/PKA and ROS/MAPK signaling pathways and is a potential natural safe whitening sunscreen additive.

Downregulation of TUG1 promotes melanogenesis and UVB-induced melanogenesis.

Studies have revealed that taurine upregulated gene 1 (TUG1), an important member of the long non-coding RNA family, is involved in the regulation of cell growth, tumorigenesis and invasion, insulin secretion and so on. However, its role in melanogenesis has not been explored. This study attempts to explore the effects of TUG1 on melanogenesis and its regulatory mechanisms. We evaluated the expression changes in melanogenesis-related genes and detected phosphorylation levels of ERK, JNK and P38 in TUG1 downregulated melanocytes. After exposure of melanocytes to UVB irradiation, the expression of TUG1 and melanogenesis-related genes was detected. We found that the expression of tyrosinase (TYR), tyrosine-related protein 1 (TYRP1) and tyrosine-related protein 2 (TYRP2) was upregulated and that the phosphorylation level of ERK was downregulated by downregulating TUG1. Inhibition of TUG1 could further upregulate the expression of UVB-induced melanogenesis-related genes. In conclusion, TUG1 negatively regulates melanocyte melanogenesis via the ERK pathway and plays a negative role in UVB-induced melanogenesis.

Functions and regulatory mechanisms of metastasis-associated lung adenocarcinoma transcript 1.

Metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) is a long noncoding RNA whose transcript is around 8 kb in length. As an important stress response molecule, MALAT1 can be expressed differently under stress conditions, such as hypoxia, high glucose, hydrogen peroxide, ultraviolet irradiation, infection, and chemical stimulation. MALAT1 is involved in regulating multiple cell behaviors, such as proliferation, apoptosis, differentiation, migration, epithelial-mesenchymal transition, autophagy, and morphological maintenance. Extensive evidence show that MALAT1 plays critical roles in the physiopathological process of embryo implantation, angiogenesis, tissue inflammation, tumor progression, liver fibrosis, cardiovascular remodeling, and diabetes progression by regulating gene transcription, forming RNA-protein complexes with proteins as a structural component, regulating protein activity, assisting protein localization, mediating epigenetic changes, or by acting as a competing endogenous RNA. Furthermore, MALAT1 can affect the sensitivity of chemotherapy and radiotherapy; therefore, it could be used as a potential drug target for chemotherapy and radiotherapy sensitization. The levels of MALAT1 are reported to be overexpressed in most tumor tissues or sera, and the expression levels of MALAT1 often affect the tumor size, stage, lymph node metastasis, and distant invasion. Therefore, MALAT1 can be used as a biomarker for early diagnosis, severity assessment, or prognostic assessment. This review outlines the current understanding of the biological role and function of MALAT1. In the meantime, we have summarized the mechanisms involved in the reulation of MALAT1 expression and the mechanisms by which MALAT1 regulates the physiological and pathological processes.

RIPK4 promotes bladder urothelial carcinoma cell aggressiveness by upregulating VEGF-A through the NF-κB pathway.

BACKGROUND: Constitutively activated nuclear factor kappa B (NF-κB) signalling plays vital roles in bladder urothelial carcinoma (BC) progression. We investigate the effect of receptor-interacting protein kinase 4 (RIPK4) on NF-κB activation and BC progression. METHODS: The expression of RIPK4 was examined in 25 cryopreserved paired bladder samples and 112 paraffin BC specimens. In vivo and in vitro assays were performed to validate effect of RIPK4 on NF-κB pathway-mediated BC progression. RESULTS: High expression of RIPK4 was observed in BC tissues and was an independent predictor for poor overall survival. Up or downregulating the expression of RIPK4 enhanced or inhibited, respectively, the migration and invasion of BC cells in vitro and in vivo. Mechanistically, RIPK4 promoted K63-linked polyubiquitination of tumour necrosis factor receptor-associated factor 2 (TRAF2), receptor-interacting protein (RIP) and NF-κB essential modulator (NEMO). RIPK4 also promoted nuclear localisation of NF-κB-p65, and maintained activation of NF-κB substantially, leading to upregulation of VEGF-A, ultimately promoting BC cell aggressiveness. CONCLUSIONS: Our data highlighted the molecular aetiology and clinical significance of RIPK4 in BC: upregulation of RIPK4 contributes to NF-κB activation, and upregulates VEGF-A, and BC progression. Targeting RIPK4 might represent a new therapeutic strategy to improve survival for patients with BC.

Molecular Engineering of α-Substituted Acrylate Ester Template for Efficient Fluorescence Probe of Hydrogen Polysulfides.

In this article, hydrogen polysulfide (H2Sn)-mediated Michael addition/cyclization cascade reactions toward acrylate ester analogues were exploited and utilized to construct novel and robust H2Sn-specific fluorescence probe for the first time. Through rational molecular engineering of the α-substituted acrylate ester template, the optimal candidate probe FP-CF3 containing trifluoromethyl-substituted acrylate ester group as recognition unit and 3-benzothiazol-7-hydroxycoumarin dye BHC as signal reporter can highly selectively detect H2Sn over other reactive sulfur species, especially biothiols including cysteine (Cys) and homocysteine (Hcy)/glutathione (GSH), with a rapid and significant turn-on fluorescence response (less than 60 s for response time and over 44-fold for signal-to-background ratio). The fast response and high selectivity of FP-CF3 for H2Sn could be attributed to a kinetically and spatially favored pentacyclic addition produced by the dual nucleophilic reaction of H2Sn with the CF3-substituted acrylate group. The big off-on fluorescence response is due to the pentacyclic intermediate results in the release of the highly fluorescent BHC. Moreover, it has been successfully applied in imaging of endogenous H2Sn fluctuation in living cells.

UVB-inhibited H19 activates melanogenesis by paracrine effects.

The long noncoding RNA H19 was reported to associate with melanogenesis. However, it remains unknown whether H19 expression will be changed by UVB irradiation and whether H19 will regulate melanocytes melanogenesis by paracrine effects. Here, we analysed the expression changes of H19 irradiated by UVB in keratinocytes and explored the mechanism of melanogenesis stimulated by H19 through paracrine effects. First, after keratinocytes were exposed to UVB irradiation, expression of H19 and pro-opiomelanocortin (POMC) was measured by qRT-PCR. Also, α-melanocyte-stimulating hormone (α-MSH) contents in cells supernatant were measured by ELISA. Then, H19 siRNAs were designed and transfected into keratinocytes by liposome. The expression changes of H19, POMC and α-MSH were detected. Besides, expression of p53 was detected by Western blot. After that, supernatant of keratinocytes with H19 siRNAs or negative control siRNA was cocultured with immortalized melanocyte line PIG1. Expression levels of MiTF, TYR, Rab27A, TYRP2, FSCN1 and MYO5A in PIG1 cells were detected by Western blot and qRT-PCR. We found that H19 expression of keratinocytes cells decreased after UVB irradiation. However, the levels of POMC, α-MSH and p53 were upregulated in UVB-irradiated cells. Compared with the negative control, H19 siRNAs could significantly increase the expression of POMC, α-MSH and p53. After supernatant of keratinocytes transfected with H19 siRNAs was cocultured with PIG1 cells, the levels of MiTF, TYR and Rab27A were upregulated in PIG1 cells. In conclusion, UVB-inhibited H19 may promote α-MSH secretion by p53 in keratinocytes and then regulate melanocytes melanogenesis through paracrine effects.

Facial nevus depigmentosus getting remarkable repigmentation by treatment with a 308-nm excimer laser: A case report.

Nevus depigmentosus (ND) is a rare, congenital, nonprogressive depigmented lesion with irregular outline. To date, the few therapeutic approaches that have been developed to treat ND have yielded unsatisfactory results. We reported on a 6-month-old girl who presented with a ND on the right side of her face for 5 months. Treatment with a 308-nm excimer laser was started once a week at 300 mJ/cm2 and then was increased by 50-100 mJ/cm2 in each subsequent session until post-treatment erythema occurred. After 10 treatments, repigmentation in the lesion was evident and remained stable 1 month later at follow up. This case supports that the 308-nm excimer laser may be a good choice for the treatment of ND.