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PURPOSE: To compare the efficacy and safety of autologous cultured melanocytes transplantation (CMT) and non-cultured epidermal cell suspension transplantation (NCES) in the treatment of piebaldism. PATIENTS AND METHODS: A retrospective study was conducted on 30 anatomically based lesions from nine piebaldism patients who underwent either CMT (n = 7) or NCES (n = 23) between 2018 and 2020. The extent of repigmentation and colour matching was evaluated in all recipient sites using a digital imaging analysis system. In addition, adverse effects have also been assessed by follow-up results. RESULTS: More than 75% repigmentation was achieved in 100% (7/7) and 60.9% (14/23) of the 30 lesions with the CMT and NCES, respectively. There were significant differences between the two methods in terms of repigmentation. The majority of patients had colour mismatches, and there was no discernible difference between the two surgical techniques. Adverse reactions rarely occurred. CONCLUSION: The present study suggested that autologous CMT may provide better repigmentation in piebaldism patients than NCES with no significant side effects.
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Piebaldismo , Vitiligo , Humanos , Estudos Retrospectivos , Piebaldismo/cirurgia , Resultado do Tratamento , Vitiligo/patologia , Melanócitos/patologiaRESUMO
BACKGROUND: Vitiligo is an acquired skin disorder with great social impact. It can be successfully treated using cultured autologous melanocytes transplantation. OBJECTIVE: To evaluate the effect of different modalities of narrow-band ultraviolet B (NB-UVB) therapy on the outcome of cultured autologous melanocyte transplantation in treating vitiligo. METHODS: Patients undergoing cultured autologous melanocyte transplantation were randomly assigned to four different study groups. Group 1 underwent 20 sessions of NB-UVB treatment before transplantation; Group 2 underwent 30 sessions of NB-UVB treatment after transplantation; Group 3 underwent 20 sessions of NB-UVB treatment before transplantation and 30 sessions after transplantation; Group 4 underwent only transplantation. RESULTS: Four hundred thirty-seven patients were enrolled. Group 3 responded best, more than 90% repigmentation was achieved in 81.3% of patients, and 94.8% patients experienced 50% or greater repigmentation. Statistical analysis showed that there was a highly significant difference between the four groups (χ(2) = 35.56, p < .001). Homogeneous skin color was obtained on the repigmentation areas, and no scarring or other serious side effects were observed. CONCLUSIONS: Cultured autologous melanocyte transplantation is an effective treatment for stable vitiligo. Combination of NB-UVB therapy with melanocyte transplantation can accelerate repigmentation of transplanted vitiliginous areas, especially if NB-UVB is given before and after transplantation.
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Melanócitos/transplante , Terapia Ultravioleta/métodos , Vitiligo/terapia , Adolescente , Adulto , Criança , Pré-Escolar , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Transplante Autólogo , Adulto JovemRESUMO
Autologous cultured pure melanocyte transplantation (CMT) can be utilized to treat stable vitiligo cases, but clinical data are insufficient to improve its efficacy. To evaluate the influence of various factors on the therapeutic effect of CMT, this single-center retrospective study enrolled stable vitiligo patients who underwent CMT between 2009 and 2020. Univariate and multivariable analysis were used to determine the factors affecting the outcome of repigmentation. The study included 491 patients with long-term follow-up data (6-120 months). It was found that 69.7% of patients achieved an excellent re-color effect and 18.4% achieved a good re-color effect. There were statistically significant differences in pigmentation between patients with stable disease course, vitiligo type, and lesion site. Overall, a significant positive correlation between the target area treatment ratio of varied lesions and the percentage of repigmentation was found. CMT is effective and well tolerated in the treatment of stable vitiligo. Various factors, especially the target area treatment ratio of varied lesions, should be carefully assessed before using CMT. As the target area treatment ratio of varied lesions could further improve the post-operative repigmentation other than type of vitiligo. This clinic trial was approved by Hangzhou Third People's Hospital (number 2023KA015, national clinical record number MR-33-23-034502).
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Melanócitos , Pigmentação da Pele , Transplante Autólogo , Vitiligo , Humanos , Vitiligo/terapia , Estudos Retrospectivos , Feminino , Masculino , Adulto , Melanócitos/transplante , Adulto Jovem , Adolescente , Pessoa de Meia-Idade , Resultado do Tratamento , Criança , Seguimentos , Células Cultivadas , Pré-EscolarRESUMO
OBJECTIVE: To determine the impact on tyrosinase expression and export from endoplasmic reticulum by inhibition of 26S proteasome. METHODS: Western blot was used to detect 26S proteasome from 8 vitiligo patients and 4 healthy controls. Melanocytes were incubated with proteasome inhibitor (lactacystin) and further detected as follows: cell survival by MTT assay, proteasome activity with fluorescence, ultrastructure observation with electron microscope, co-localization of tyrosinase and calreticulin (endoplasmic reticulum marker) by confocal laser scanning microscopy and 26S proteasome and tyrosinase with Western blot. RESULTS: The 26S proteasome expression level from lesions of vitiligo (1.05 ± 0.40) was significantly lower than the donor sites (1.82 ± 0.88) and the healthy controls (1.88 ± 0.16) (P < 0.05). But no significant difference existed between the latter two groups (P > 0.05). Compared to the untreated group, a 12-h incubation of 10 µmol/L lactacystin showed inhibitory effects on melanocytes (0.999 ± 0.110 vs 1.372 ± 0.127, P < 0.05) and significantly decreased proteasome activity (0.234 ± 0.019 vs 1, P < 0.01). Expansion rate of endoplasmic reticulum in the lactacystin group (1.91 ± 0.17) was significantly higher than that of the untreated cells (1.17 ± 0.11) (P < 0.05). More tyrosinase co-localized with calreticulin in endoplasmic reticulum in lactacystin-treated cells was observed than that of the untreated group. Compared with the untreated group, significantly decreased levels of tyrosinase (146 ± 10 vs 269 ± 8, P < 0.01) and tyrosinase activity (0.159 ± 0.017 vs 0.221 ± 0.019, P < 0.01) were shown in the lactacystin group (P < 0.05). CONCLUSIONS: Significantly decrease of 26S proteasome is found in lesions of vitiligo patients. Inhibition of 26S proteasome may lead to expansion of endoplasmic reticulum of melanocytes, impact export of tyrosinase from melanocyte endoplasmic reticulum and expression of tyrosinase.
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Acetilcisteína/análogos & derivados , Retículo Endoplasmático/metabolismo , Melanócitos/efeitos dos fármacos , Melanócitos/metabolismo , Monofenol Mono-Oxigenase/metabolismo , Complexo de Endopeptidases do Proteassoma/metabolismo , Acetilcisteína/farmacologia , Adulto , Estudos de Casos e Controles , Células Cultivadas , Inibidores de Cisteína Proteinase/farmacologia , Feminino , Humanos , Masculino , Melanócitos/citologia , Vitiligo/metabolismo , Vitiligo/patologia , Adulto JovemRESUMO
Following the publication of the above article, an interested reader drew to the authors' attention that the Transwell cell migration assay data shown in Fig. 4A appeared to be partly overlapping with data presented for experiments performed under different experimental conditions in Figs. 4D and E. The authors independently examined the figure and realized that inadvertent errors had been made during the assembly of Fig. 4; furthermore, owing to the time that has elapsed since this paper was published, the authors no longer had access to the original data. Accordingly, to further verify the conclusions reported in the study, the authors repeated these experiments, and the results obtained were found to be consistent with the original findings. The new version of Fig. 4 is shown below. The authors are grateful to the Editor of International Journal of Molecular Medicine for allowing them the opportunity to publish this Corrigendum, and apologize to the readership for any inconvenience caused. [the original article was published in International Journal of Molecular Medicine 26: 57-65, 2010; DOI: 10.3892/ijmm_00000435].
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BACKGROUND: Autologous non-cultured melanocyte-keratinocyte transplantation (MKTP) can be used to treat stable vitiligo cases, but there were insufficient clinical data to evaluate its safety and efficacy. OBJECTIVE: To assess the influence of various factors on the therapeutic outcome of MKTP. METHOD: The single-center retrospective study included stable vitiligo patients who underwent MKTP between June 2009 and June 2018. Univariate and/or multivariable analysis were used to determine the factors affecting the outcome of repigmentation. RESULT: The study comprised 2283 patients who had long-term follow-up data (12-108months). Excellent repigmentation was achieved in 400/606 (66%),788/1341 (58.8%),437/684 (63.9%),18/24 (75%) patients with segmental vitiligo, pre-MKTP phototherapy, younger than 24 years, the lesion on the perineum and scrotum, respectively. However, the patients with a positive family history, Koebner phenomenon responded worse(χ2=29.417, P<0.001; χ2=107.397, P<0.001; respectively). Overall, a significant positive correlation between duration of stability and percentage of repigmentation was found (χ2=42.053, P<0. 001). CONCLUSION: MKTP is efficient and well tolerated for stable vitiligo treatment. Various factors such as duration of disease stability, vitiligo type, family history, site of lesion should be carefully assessed before using MKTP, as it would further improve the post-operative repigmentation.
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Queratinócitos/transplante , Melanócitos/transplante , Vitiligo/cirurgia , Adolescente , Adulto , Criança , Pré-Escolar , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Transplante Autólogo , Adulto JovemRESUMO
OBJECTIVE: To investigate the roles of InnVit (FBX011) gene in melanocytes by detecting the expression of InnVit gene in vitiligo and analyzing the impact of InnVit gene on morphology of endoplasmic reticulum (ER) and the tyrosinase export from ER. METHODS: The lesion tissues and the donor tissues were collected from 10 vitiligo patients to examine the InnVit gene expression by immunohistochemistry. Synthesized specific siRNA and constructed plasmid P3XF-P120 were separately transfected into cells for the silence and over-expression of InnVit gene with lipofectamine(TM) 2000. The untreated cells were used as control. Morphology of ER of cells from the above three groups was observed under electron microscope. Co-localization of tyrosinase and calreticulin was identified by confocal laser scanning microscopy. InnVit, tyrosinase and calreticulin were examined by Western blot. RESULTS: In vitiligo patients, the expression of InnVit gene in the lesions was markedly lower than that in the donor tissues. The normal morphology of ER was found in the untreated and the plasmid groups whereas inflated ER was shown in siRNA group. And the relative inflation rate in siRNA group (1.97 +/- 0.48) was higher than that in the untreated group (1.28 +/- 0.09) and plasmid group (1.24 +/- 0.13) (both P = 0.001). In the untreated and the plasmid groups, tyrosinase was expressed beyond the scope marked by ER marker protein calreticulin partly, but co-localized with calreticulin in ER in the siRNA group. Western blot showed that, contrast to the untreated group (0.320 +/- 0.020), a lower expression level of InnVit in the siRNA group (0.030 +/- 0.004, P = 0.001) and a higher expression of InnVit in the plasmid group were shown (0.710 +/- 0.040, P = 0.001). No significant difference about the expression level of calreticulin was observed among the three groups (P > 0.05). As compared with the untreated group (0.350 +/- 0.030), a higher tyrosinase level in the siRNA group (1.040 +/- 0.060, P = 0.001) and in the plasmid group (0.720 +/- 0.030, P = 0.001) was found. And the former was higher than the latter (P = 0.001). CONCLUSION: A lower expression of InnVit is observed in the lesion tissues than in the donor tissues from vitiligo patients. The InnVit gene can have an impact on the morphology of ER and tyrosinase export from ER. And it may further affect the function of melanocytes.
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Retículo Endoplasmático/metabolismo , Proteínas F-Box/metabolismo , Monofenol Mono-Oxigenase/metabolismo , Proteína-Arginina N-Metiltransferases/metabolismo , Vitiligo/genética , Adulto , Células Cultivadas , Retículo Endoplasmático/genética , Retículo Endoplasmático/patologia , Feminino , Humanos , Masculino , Melanócitos/citologia , Melanócitos/metabolismo , RNA Interferente Pequeno/genética , Pele/patologia , Vitiligo/metabolismo , Adulto JovemRESUMO
Vitiligo is an acquired pigmentary disorder and its pathogenesis remains unclear. Oxidative stress is considered to be the initial pathogenic event in the melanocyte destruction. NF-E2-related factor2 (Nrf2) is a transcription factor regulating the expression of detoxifying and antioxidant genes. To investigate the association of the Nrf2 gene promoter polymorphisms with vitiligo in Chinese Han population, the genotypes of -686A/G, -684G/A and -650C/A and the genotyping of variable number of tandem repeat were detected. The data were analysed by the chi-square test and the risk was evaluated by calculating OR and 95% CI. There was statistically significant difference in genotypic and allelic frequencies of -650C/A between the two groups (P < 0.05). A(-650) allele was significantly associated with the risk for vitiligo (OR = 1.724, chi(2) = 18.096). Polymorphism of the Nrf2 gene promoter at -650C/A was associated with the development of vitiligo and A(-650) allele may be one of the risk factors.
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Fator 2 Relacionado a NF-E2/genética , Polimorfismo Genético , Vitiligo/genética , Adolescente , Adulto , Fatores Etários , Povo Asiático , Feminino , Frequência do Gene , Predisposição Genética para Doença , Genótipo , Humanos , Masculino , Pessoa de Meia-Idade , Razão de Chances , Polimorfismo de Nucleotídeo Único , Fatores de Risco , Fatores Sexuais , Sequências de Repetição em Tandem/genética , Vitiligo/patologia , Adulto JovemRESUMO
BACKGROUND: Vitiligo is a common acquired depigmentation skin disease characterized by loss or dysfunction of melanocytes within the skin lesion, but its pathologenesis is far from lucid. The gene expression profiling of segmental vitiligo (SV) and generalized vitiligo (GV) need further investigation. OBJECTIVE: To better understanding the common and distinct factors, especially in the view of gene expression profile, which were involved in the diseases development and maintenance of segmental vitiligo (SV) and generalized vitiligo (GV). METHODS: Peripheral bloods were collected from SV, GV and healthy individual (HI), followed by leukocytes separation and total RNA extraction. The high-throughput whole genome expression microarrays were used to assay the gene expression profiles between HI, SV and GV. Bioinformatics tools were employed to annotated the biological function of differently expressed genes. Quantitative PCR assay was used to validate the gene expression of array. RESULTS: Compared to HI, 239 over-expressed genes and 175 down-expressed genes detected in SV, 688 over-expressed genes and 560 down-expressed genes were found in GV, following the criteria of log2 (fold change)≥0.585 and P value<0.05. In these differently expressed genes, 60 over-expressed genes and 60 down-expressed genes had similar tendency in SV and GV. Compared to SV, 223 genes were up regulated and 129 genes were down regulated in GV. In the SV with HI as control, the differently expressed genes were mainly involved in the adaptive immune response, cytokine-cytokine receptor interaction, chemokine signaling, focal adhesion and sphingolipid metabolism. The differently expressed genes between GV and HI were mainly involved in the innate immune, autophagy, apoptosis, melanocyte biology, ubiquitin mediated proteolysis and tyrosine metabolism, which was different from SV. While the differently expressed genes between SV and GV were mainly involved in the metabolism pathway of purine, pyrimidine, glycolysis and sphingolipid. CONCLUSIONS: Above results suggested that they not only shared part bio-process and signal pathway, but more important, they utilized different biological mechanism in their pathogenesis and maintenance. Our results provide a comprehensive view on the gene expression profiling change between SV and GV especially in the side of leukocytes, and may facilitate the future study on their molecular mechanism and theraputic targets.
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Regulação da Expressão Gênica , Transcriptoma , Vitiligo/genética , Adolescente , Adulto , Apoptose , Autofagia , Estudos de Casos e Controles , Análise por Conglomerados , Biologia Computacional , Citocinas/metabolismo , Feminino , Perfilação da Expressão Gênica , Predisposição Genética para Doença , Glicólise , Humanos , Sistema Imunitário , Masculino , Melanócitos/citologia , Oxirredução , Purinas/química , Pirimidinas/química , Espécies Reativas de Oxigênio/metabolismo , Esfingolipídeos/química , Adulto JovemRESUMO
Swollen endoplasmic reticulum (ER) is commonly observed in the melanocytes of vitiligo patients; however, the cause and proteins involved in this remain to be elucidated. Oxidative stress has been reported to be involved in the pathogenesis of vitiligo and previous studies have demonstrated that hydrogen peroxide (H2O2) induced melanocyte apoptosis, whereas quercetin exhibited cytoprotective activities against the effects of H2O2. The aim of the present study was to further investigate the role of H2O2 in the ER of melanocytes as well as its role in the export of tyrosinase from ER; in addition, the present study aimed to determine the mechanism by which quercetin protects against the effects of H2O2. The results demonstrated that melanocyte cells treated with H2O2 presented with swollen ER; however, a normal ER configuration was observed in untreated cells as well as quercetin/H2O2treated cells. Furthermore, H2O2 inhibited tyrosinase export from the ER and decreased expression levels of tyrosinase; however, quercetin was found to attenuate the effects induced by H2O2. In conclusion, the results of the present study confirmed the hypothesis that H2O2 induced ER dilation and hindered functional tyrosinase export from the ER of melanocytes. It was also found that quercetin significantly weakened these effects mediated by H2O2, therefore it may have the potential for use in the treatment of vitiligo.
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Retículo Endoplasmático/efeitos dos fármacos , Retículo Endoplasmático/metabolismo , Peróxido de Hidrogênio/farmacologia , Melanócitos/efeitos dos fármacos , Melanócitos/metabolismo , Monofenol Mono-Oxigenase/metabolismo , Quercetina/farmacologia , Calbindina 2/metabolismo , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Retículo Endoplasmático/ultraestrutura , Humanos , Estresse Oxidativo/efeitos dos fármacos , Ligação Proteica , Transporte Proteico , Espécies Reativas de Oxigênio/metabolismoRESUMO
OBJECTIVES: To compare the efficacy of blister roof grafting (BG), cultured melanocytes transplantation (CMT) and non-cultured epidermal cell suspension transplantation (NCES) in the treatment of stable vitiligo. METHODS: In each person of 83 vitiligo patients one vitiligo macule was selected and divided in three areas for separate treatment with BG, CMT and NCES in the same session. The results were evaluated 12-month post-surgery for the extent of repigmentation and color match. RESULTS: A satisfactory result (>50% repigmentation) was achieved in 92%, 82% and 81% of the 83 patients with the BG, CMT and NCES methods, respectively. Significant differences between the BG and CMT groups (p = 0.038), and between BG and NCES groups (p = 0.017) were observed, but not between the CMT and NCES groups (p = 0.986). The extent of repigmentation on the head neck and trunk was superior to that of the extremities by all the three methods. A difference in the time of onset of repigmentation was observed, with repigmentation first appearing after 10 days, 20-30 days and >30 days in the BG, CMT and NCES groups, respectively. CONCLUSIONS: All the three methods are safe and effective to treat vitiligo. Future studies with larger groups are warranted to confirm our results.
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Vesícula , Células Epiteliais/transplante , Melanócitos/transplante , Vitiligo/cirurgia , Adolescente , Adulto , Extremidades , Feminino , Humanos , Masculino , Pescoço , Tronco , Transplante Autólogo , Resultado do Tratamento , Adulto JovemRESUMO
Vitiligo is an acquired cutaneous depigmentation disorder which has a deleterious effect on the psychosexual function of many individuals; the genitalia are the common site for depigmentation. Here, the authors report two cases of focal vitiligo affecting the scrotum of the genital organs which were successfully treated by autologous cultured melanocyte transplantation. Autologous cultured melanocyte transplantation on the scrotum is shown to be a relative effective method of treatment for vitiligo.
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BACKGROUND: Interferon-γ (IFN-γ) plays an important role in the proceedings of vitiligo through recruiting lymphocytes to the lesional skin. However, the potential effects of IFN-γ on skin melanocytes and the subsequent contribution to the vitiligo pathogenesis are still unclear. OBJECTIVE: To investigate the effects of IFN-γ on viability and cellular functions of melanocytes. METHODS: Primary human melanocytes were treated with IFN-γ. Cell viability, apoptosis, cell cycle melanin content and intracellular reactive oxygen species (ROS) level were measured. mRNA expression was examined by real-time PCR. The release of interleukin 6 (IL-6) and heat shock protein 70 (HSP-70) was monitored by ELISA. ß-galactosidase staining was utilized to evaluate melanocyte senescence. RESULTS: Persistent IFN-γ treatment induced viability loss, apoptosis, cell cycle arrest and senescence in melanocytes. Melanocyte senescence was characterized as the changes in pigmentation and morphology, as well as the increase of ß-galactosidase activity. Increase of p21Cip1/Waf1 protein was evident in melanocytes after IFN-γ treatment. IFN-γ induction of senescence was attenuated by siRNAs against p21, Janus kinase 2 (JAK2) or signal transducer and activator of transcription 1 (STAT1), but not by JAK1 siRNA nor by p53 inhibitor pifithrin-α. IFN-γ treatment increased the accumulation of intracellular ROS in melanocytes, while ROS scavenger N-acetyl cysteine (NAC) effectively inhibited IFN-γ induced p21 expression and melanocyte senescence. IL-6 and HSP-70 release was significantly induced by IFN-γ treatment, which was largely inhibited by NAC. The increase of IL-6 and HSP-70 release could also be observed in senescent melanocytes. CONCLUSION: IFN-γ can induce senescence in melanocytes and consequently enhance their immuno-competency, leading to a vitiligo-prone milieu.
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Envelhecimento/metabolismo , Envelhecimento/fisiologia , Senescência Celular/fisiologia , Interferon gama/metabolismo , Melanócitos/metabolismo , Melanócitos/fisiologia , Acetilcisteína/farmacologia , Envelhecimento/efeitos dos fármacos , Apoptose/efeitos dos fármacos , Apoptose/fisiologia , Ciclo Celular/efeitos dos fármacos , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Células Cultivadas , Senescência Celular/efeitos dos fármacos , Inibidor p16 de Quinase Dependente de Ciclina/metabolismo , Inibidor de Quinase Dependente de Ciclina p21/metabolismo , Humanos , Interleucina-6/metabolismo , Proteínas de Ligação ao Ferro/metabolismo , Janus Quinase 1/metabolismo , Janus Quinase 2/metabolismo , Melanócitos/efeitos dos fármacos , Fosforilação/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Fator de Transcrição STAT1/metabolismo , Transdução de Sinais/efeitos dos fármacos , Proteína Supressora de Tumor p53/metabolismo , beta-Galactosidase/metabolismoRESUMO
Microphthalmia-associated transcription factor (MITF) is a master regulator in melanocyte proliferation, development, survival and melanoma formation. In melanocyte dysfunction disease, it is observed that the expressions of MITF, tyrosinase (TYR), tyrosinase related protein 1 (TYRP1) and tyrosinase related protein 2 (TYRP2)/dopachrome tautomerase (DCT) are changed, the consequence of which remains unclear. In this study, we focused on the change of microRNA (miRNA) profiles and Tyrosinase Related Proteins (TRPs) in MITF knocked down melanocytes. For the first time, we assayed the MITF-KD miRNA profiles using a miRNA microarray and found that hsa-miR-1225-3p, hsa-miR-634, hsa-miR-197, hsa-miR-766, hsa-miR-574-5p and hsa-miR-328 were upregulated, and hsa-miR-720 and hsa-miR-1308 were downregulated in MITF knocked down melanocytes. These miRNAs were validated by miRNA real time qPCR. These miRNA potential targets, especially the TRPs, were analyzed according to the miRNA database (Sanger Center). By TargetScan prediction, the hsa-miR-634 and hsa-miR-328 have poorly conserved sites on TYR and hsa-miR-197 have poorly conserved sites on TYR1. Through qPCR and western blotting we found that the expression of TYR and TYRP1 were dramatically decreased and the expression of TYRP2 was increased in MITF knocked down melanocytes (MITF-KD). These results suggested that the miRNAs may be involved in MITF regulation of TYR, TYRP1 and TYRP2, which provides a new clue for understanding the role of miRNAs in melanocyte dysfunctional disease.
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Melanócitos/metabolismo , MicroRNAs/genética , Fator de Transcrição Associado à Microftalmia/deficiência , Fator de Transcrição Associado à Microftalmia/genética , Western Blotting , Células Cultivadas , Humanos , Oxirredutases Intramoleculares/genética , Oxirredutases Intramoleculares/metabolismo , Monofenol Mono-Oxigenase/genética , Monofenol Mono-Oxigenase/metabolismo , Oxirredutases/genética , Oxirredutases/metabolismo , Reação em Cadeia da Polimerase , Interferência de RNA/fisiologiaRESUMO
Niacin and its related derivatives have been shown to have effects on cellular activities. However, the molecular mechanism of its reduced immunosuppressive effects and photoprotective effects remains unclear. In this study, we investigated the molecular mechanism of the photoprotective effect of niacin in ultraviolet (UV)-irradiated human skin keratinocytes (HaCaT cells). We found that niacin effectively suppressed the UV-induced cell death and cell apoptosis of HaCaT cells. Existing data have shown that AKT activation is involved in the cell survival process. Yet, the potential mechanism of niacin in protection against UV-induced skin damage has thus far not fully been eluvidated. We observed that niacin pretreatment enhances UV induced activation of AKT (Ser473 phosphorylation) as well as that of the downstream signal mTOR (S6 and 4E-BP1 phosphorylation). The PI3K/AKT inhibitor, LY294002, and the mTOR inhibitor, rapamycin, largely neutralized the protective effects of niacin, suggesting that AKT and downstream signaling mTOR/S6 activation are necessary for the niacin-induced protective effects against UV-induced cell death and cell apoptosis. Collectively, our data suggest that niacin may be utilized to prevent UV-induced skin damage and provide a novel mechanism of its photoprotective effects against the UV radiation of sunlight by modulating both AKT and downstream mTOR signaling pathways.
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Apoptose/efeitos dos fármacos , Apoptose/efeitos da radiação , Queratinócitos/efeitos dos fármacos , Queratinócitos/efeitos da radiação , Niacina/farmacologia , Raios Ultravioleta/efeitos adversos , Western Blotting , Sobrevivência Celular , Células Cultivadas , Humanos , Queratinócitos/citologia , Microscopia Confocal , Fosforilação , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transdução de Sinais/efeitos dos fármacos , Pele/citologia , Pele/efeitos dos fármacos , Pele/efeitos da radiação , Serina-Treonina Quinases TOR/metabolismoRESUMO
Human vitiligo is an acquired depigmenting skin disorder characterized by milk-white skin macules resulting from a chronic and progressive loss of melanocytes. It has been suggested that autoimmune mechanisms are involved in this disorder. We undertook this project to obtain an MCHR1-C linear peptide containing four main MCHR1 B-cell epitopes in an attempt to detect the IgG antibody against MCHR1 in vitiligo. The target gene encoding the MCHR1-C peptide was cloned into a pGEX-4T-2 expression vector, expressed in Escherichia coli BL21, and purified using a GST column. The molecular weight was analyzed by SDS-PAGE and western blotting. The IgG antibody response to MCHR1 was detected by ELISA with MCHR1-C as a coated antigen, and the absorption experiment was used to assess the binding ability of the Ab detected by MCHR1-C with a membrane protein in human epidermal melanocytes. The purified peptide MCHR1-C with a molecular weight of 33 kDa was obtained, and could bind to the MCHR1 antibody in human sera. Of the vitiligo patient sera examined, 24 of 145 (16.55%) tested positive for the MCHR1 antibody, and the frequency in the vitiligo patient group was significantly greater compared to the normal control. However, no significant difference between gender, disease duration, clinical subtype or family history between the two groups was observed. In addition, the Ab detected by MCHR1-C in sera was specifically absorbed by the membrane protein obtained from human epidermal melanocytes. Collectively, our data suggest that the MCHR1-C peptide can be used to detect the MCHR1 antibody in vitiligo patients as a coated antigen instead of MCHR1 protein. We conclude that the level of MCHR1 antibody in active vitiligo patients is significantly higher than that in healthy individuals, while gender, disease duration, clinical subtype and family history have no association with the level of MCHR1 antibody in vitiligo patients.
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Anticorpos/sangue , Receptores de Somatostatina/imunologia , Proteínas Recombinantes de Fusão/biossíntese , Vitiligo/imunologia , Adolescente , Adulto , Estudos de Casos e Controles , Criança , Clonagem Molecular , Epitopos , Feminino , Humanos , Masculino , Melanócitos/metabolismo , Pessoa de Meia-Idade , Receptores de Somatostatina/metabolismo , Proteínas Recombinantes de Fusão/isolamento & purificação , Vitiligo/sangue , Adulto JovemRESUMO
Our previous study has shown that VIT1 gene in Chinese vitiligo patients is de facto the FBXO11 gene, and the silencing of that gene has an impact on the ultrastructure of melanocytes. In this study, we further identified the role of the FBXO11 gene in melanocytes and the relationship between dilated endoplasmic reticulum (ER) and tyrosinase by inhibition and overexpression of FBXO11 gene. Cell proliferation, apoptosis, cycle and migration of melanocytes were examined when the FBXO11 gene was silenced or overexpressed. The results showed that FBXO11 gene promoted cell proliferation and suppressed cell apoptosis, and yet had little effect on cell migration. Obvious swelling of ER was found in the cells transfected with siRNA of FBXO11 gene. Interestingly, protein level of tyrosinase was extraordinarily high following inhibition of FBXO11 gene. Further examination revealed that tyrosinase and calreticulin were co-localized in ER of transfected cells following siRNA of FBXO11 gene, suggesting that tyrosinase could not be exported from ER effectively. Collectively, our results support the notion that FBXO11 plays an important role in regulating proliferation and apoptosis of melanocytes, and functional export of tyrosinase from ER in vitiligo melanocytes.
Assuntos
Apoptose/fisiologia , Retículo Endoplasmático/metabolismo , Proteínas F-Box/fisiologia , Melanócitos/metabolismo , Monofenol Mono-Oxigenase/metabolismo , Proteína-Arginina N-Metiltransferases/fisiologia , Western Blotting , Calreticulina/metabolismo , Ciclo Celular , Proliferação de Células , Células Cultivadas , Retículo Endoplasmático/ultraestrutura , Exocitose , Proteínas F-Box/genética , Proteínas F-Box/metabolismo , Citometria de Fluxo , Humanos , Recém-Nascido , Masculino , Metaloproteinase 2 da Matriz/metabolismo , Metaloproteinase 9 da Matriz/metabolismo , Melanócitos/citologia , Melanócitos/ultraestrutura , Microscopia Eletrônica de Transmissão , Proteína-Arginina N-Metiltransferases/genética , Proteína-Arginina N-Metiltransferases/metabolismo , Interferência de RNA , Reação em Cadeia da Polimerase Via Transcriptase Reversa , TransfecçãoRESUMO
We conducted a genome-wide association study of generalized vitiligo in the Chinese Han population by genotyping 1,117 cases and 1,429 controls. The 34 most promising SNPs were carried forward for replication in samples from individuals of the Chinese Han (5,910 cases and 9,916 controls) and Chinese Uygur (713 cases and 824 controls) populations. We identified two independent association signals within the major histocompatibility complex (MHC) region (rs11966200, Pcombined=1.48x10(-48), OR=1.90; rs9468925, Pcombined=2.21x10(-33), OR=0.74). Further analyses suggested that the strong association at rs11966200 might reflect the reported association of the HLA-A*3001, HLA-B*1302, HLA-C*0602 and HLA-DRB1*0701 alleles and that the association at rs9468925 might represent a previously unknown HLA susceptibility allele. We also identified one previously undescribed risk locus at 6q27 (rs2236313, Pcombined=9.72x10(-17), OR=1.20), which contains three genes: RNASET2, FGFR1OP and CCR6. Our study provides new insights into the genetic basis of vitiligo.