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1.
Nat Cell Biol ; 22(4): 372-379, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32231306

RESUMO

The availability of nucleotides has a direct impact on transcription. The inhibition of dihydroorotate dehydrogenase (DHODH) with leflunomide impacts nucleotide pools by reducing pyrimidine levels. Leflunomide abrogates the effective transcription elongation of genes required for neural crest development and melanoma growth in vivo1. To define the mechanism of action, we undertook an in vivo chemical suppressor screen for restoration of neural crest after leflunomide treatment. Surprisingly, we found that alterations in progesterone and progesterone receptor (Pgr) signalling strongly suppressed leflunomide-mediated neural crest effects in zebrafish. In addition, progesterone bypasses the transcriptional elongation block resulting from Paf complex deficiency, rescuing neural crest defects in ctr9 morphant and paf1(alnz24) mutant embryos. Using proteomics, we found that Pgr binds the RNA helicase protein Ddx21. ddx21-deficient zebrafish show resistance to leflunomide-induced stress. At a molecular level, nucleotide depletion reduced the chromatin occupancy of DDX21 in human A375 melanoma cells. Nucleotide supplementation reversed the gene expression signature and DDX21 occupancy changes prompted by leflunomide. Together, our results show that DDX21 acts as a sensor and mediator of transcription during nucleotide stress.


Assuntos
RNA Helicases DEAD-box/genética , Melanócitos/metabolismo , Crista Neural/metabolismo , Oxirredutases atuantes sobre Doadores de Grupo CH-CH/genética , Receptores de Progesterona/genética , Proteínas de Peixe-Zebra/genética , Animais , Linhagem Celular Tumoral , RNA Helicases DEAD-box/metabolismo , Embrião não Mamífero , Regulação da Expressão Gênica no Desenvolvimento , Humanos , Leflunomida/farmacologia , Melanócitos/efeitos dos fármacos , Melanócitos/patologia , Crista Neural/efeitos dos fármacos , Crista Neural/crescimento & desenvolvimento , Nucleotídeos , Oxirredutases atuantes sobre Doadores de Grupo CH-CH/metabolismo , Fosfoproteínas/genética , Fosfoproteínas/metabolismo , Progesterona/metabolismo , Ligação Proteica , Receptores de Progesterona/metabolismo , Transdução de Sinais , Estresse Fisiológico/genética , Elongação da Transcrição Genética , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Peixe-Zebra/embriologia , Peixe-Zebra/genética , Peixe-Zebra/metabolismo , Proteínas de Peixe-Zebra/metabolismo
2.
Toxicol Lett ; 319: 197-203, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-31785464

RESUMO

The chemical warfare agent sulfur mustard (SM) affects all cells in the epidermis including melanocytes which are responsible for melanin synthesis. After exposure to SM, pigment abnormalities like hypo- and hyperpigmentation can occur. The underlying molecular pathomechanisms of SM exposure on human melanogenesis have not been elucidated so far. In our study, we investigated the effect of SM on human melanocytes and melanogenesis. Normal human epidermal melanocytes (NHEM) were used as in vitro model and they were exposed to different concentrations of SM (4.5 µM-100 µM). Melanin production was analyzed by absorption measurements at 405 nm. In addition, quantitative real-time PCR (qPCR) and Western blot experiments were performed to determine the expression of essential melanogenesis-related proteins including tyrosinase (TYR), tyrosinase-related protein (TRP) 1 and 2 and microphthalmia transcription factor (MITF). Our findings demonstrated that exposure to low SM concentrations increased melanin synthesis accompanied with an increase in protein expression. In contrast, high SM concentrations led to decreased melanin content and a downregulation in expression of all investigated melanogenesis-associated proteins. We concluded that low SM concentrations may cause hyperpigmentation while high SM concentrations decreased melanin content which may explain hypopigmented skin areas in SM exposed patients.


Assuntos
Substâncias para a Guerra Química/toxicidade , Melaninas/biossíntese , Gás de Mostarda/toxicidade , Células Cultivadas , Relação Dose-Resposta a Droga , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Hiperpigmentação/induzido quimicamente , Hipopigmentação/induzido quimicamente , Oxirredutases Intramoleculares/efeitos dos fármacos , Melaninas/genética , Melanócitos/efeitos dos fármacos , Melanócitos/metabolismo , Fator de Transcrição Associado à Microftalmia/biossíntese , Fator de Transcrição Associado à Microftalmia/genética , Monofenol Mono-Oxigenase/biossíntese , Monofenol Mono-Oxigenase/genética , Tripsina/biossíntese , Tripsina/genética
3.
Fitoterapia ; 140: 104416, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31704261

RESUMO

Vitiligo is a common depigmentary disease characterized as diagnosis simplicity and cure difficulty in view of the ambiguity of etiology, thus novel and effective treatments are urgently needed. Paeoniflorin, the major active compound extracted from the root of Paeonia lactiflora Pall, a traditional Chinese medicine, has been validated pharmacological properties such as antioxidant stress, a theory participating in the occurrence of vitiligo, but the effect on melanogenesis is still unclear. In this study, melanosythesis effect of paeoniflorin and the potential mechanism were evaluated. We found that treatment with paeoniflorin at the concentration of 10 µg/ml significantly increased melanin content and intracellular tyrosinase activity of human melanocytes, in accordance with the elevation of protein levels of microphthalmia-associated transcription factor (MITF), tyrosinase-related protein 1 (TRP-1). In addition, we also investigated that paeoniflorin promoted phosphorylation of cAMP-response element binding (CREB) and extracellular signal-regulated kinase (ERK) without affecting p38 and c-Jun N-terminal kinase (JNK). These results demonstrated that paeoniflorin had a synergistic effect on normal human melanocytes via ERK/CREB pathway with up-regulation of MITF and TRP-1, enhancing melanin synthesis. Meanwhile, the milder pathological changes in vitiligo mice treat with paeoniflorin also confirmed its potential in treating vitiligo. To sum up, we suggest that paeoniflorin may be a potential medicine of vitiligo treatment in clinical.


Assuntos
Glucosídeos/farmacologia , Melanócitos/efeitos dos fármacos , Monoterpenos/farmacologia , Vitiligo/tratamento farmacológico , Animais , Células Cultivadas , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/metabolismo , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Feminino , Humanos , Glicoproteínas de Membrana/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Fator de Transcrição Associado à Microftalmia/metabolismo , Oxirredutases/metabolismo , Fosforilação , Distribuição Aleatória
4.
Oxid Med Cell Longev ; 2019: 2841814, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31871544

RESUMO

Oxidative stress is known to induce melanocyte death, but the underlying mechanisms are incompletely understood. To identify oxidative stress-induced global gene expression changes in melanocytes, we treated PIG1 melanocytes with H2O2 in a dose- and time-dependent manner and performed RNA-seq. This approach allowed us to capture the events occurring early as well as late phase after treatment with H2O2. Our bioinformatics analysis identified differentially expressed genes involved in various biological processes of melanocytes which are known to contribute to the vitiligo development, such as apoptosis, autophagy, cell cycle regulation, cell adhesion, immune and inflammatory responses, melanocyte pluripotency, and developmental signaling such as WNT and NOTCH pathways. We uncovered several novel genes that are not previously described to be involved in melanocytic response to stress nor in vitiligo pathogenesis. Quantitative PCR and western blot analysis of selected proteins, performed on PIG1 and primary human epidermal melanocytes, confirmed the RNA-seq data. Interestingly, we discovered an aberrant regulation of several transcription factors that are involved in diabetes, neurological, and psychiatric diseases, all of which are comorbid conditions in patients with vitiligo. Our results may lead to a better understanding of the molecular mechanisms underlying vitiligo pathogenesis and help developing new drug targets for effective treatment.


Assuntos
Melanócitos/metabolismo , Vitiligo/metabolismo , Vitiligo/patologia , Morte Celular/efeitos dos fármacos , Linhagem Celular , Biologia Computacional , Humanos , Peróxido de Hidrogênio/farmacologia , Melanócitos/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Estresse Oxidativo/fisiologia , Reação em Cadeia da Polimerase , Espécies Reativas de Oxigênio/metabolismo , Transdução de Sinais/efeitos dos fármacos
5.
Int J Mol Sci ; 20(18)2019 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-31509972

RESUMO

Skin aging is generally caused by a decline in the components of the extracellular matrix (e.g., collagen and elastin) and due to inflammatory phenomena. Many growth factors and peptides with cell-growth and collagen-synthesis activities have shown promise in their application in anti-aging materials. However, the effect of collagen production, without anti-inflammatory effect, and skin penetration may not be enough for their use in anti-aging agents. Previously, we reported a substance P (SP)-based hydrogel (SP gel) that had potential wound-healing activities via induction of skin cell regeneration and collagen synthesis. Here, we analyzed the anti-aging activities and skin absorption effects of SP gel to extend its characterization. Toxicity tests, performed on human dermal fibroblasts (HDFs) and on a reconstructed 3D human skin model, indicated SP gel to be safe for long-term use, without causing irritation, even at high concentrations. In-vitro analysis revealed that SP gel elicited stronger collagen production activities than SP alone, and promoted anti-inflammatory effects with increased skin absorption properties. Moreover, SP gel did not induce melanin synthesis in a keratinocyte-melanocyte co-culture system. Together, the results suggest that SP gel has potential cosmetic effects and applicability as a novel ingredient in anti-aging products.


Assuntos
Hidrogéis/farmacologia , Envelhecimento da Pele/efeitos dos fármacos , Pele/efeitos dos fármacos , Substância P/farmacologia , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Técnicas de Cocultura , Colágeno/metabolismo , Cosméticos/farmacocinética , Cosméticos/farmacologia , Matriz Extracelular/metabolismo , Fibroblastos/citologia , Fibroblastos/efeitos dos fármacos , Fibroblastos/metabolismo , Humanos , Queratinócitos/citologia , Queratinócitos/efeitos dos fármacos , Queratinócitos/metabolismo , Melanócitos/citologia , Melanócitos/efeitos dos fármacos , Melanócitos/metabolismo , Pele/citologia , Pele/metabolismo , Absorção Cutânea/efeitos dos fármacos
6.
Biol Pharm Bull ; 42(9): 1446-1449, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31474706

RESUMO

During the process of skin regeneration following a skin injury, de novo hair follicle regeneration is initiated after wounding; however, these regenerated hairs are mostly unpigmented. The activation of epidermal melanocyte stem cells and their differentiation into regenerating hair follicles have been shown to be necessary for the pigmented hair regeneration after wounding. To determine the role of flavonoids in the regeneration of pigmented hairs, we applied the candidate flavonoids to the regenerating hair follicles after wounding and identified the flavonoid species that maximally induced pigmented hair regeneration. Flavonoids with two OH groups in the B-ring, such as sterubin, luteolin, and hydroxygenkwanin, showed promising effects in regenerating black pigmented hairs, while those with one OH group in the B-ring showed no significant change. Thus, flavonoids with two OH groups in their B-ring could be studied further as potential wound healing agents with the ability to regenerate pigmented hair.


Assuntos
Flavonoides/farmacologia , Cor de Cabelo , Folículo Piloso/efeitos dos fármacos , Regeneração/efeitos dos fármacos , Pele/lesões , Cicatrização/efeitos dos fármacos , Animais , Células Epidérmicas/efeitos dos fármacos , Células Epidérmicas/fisiologia , Flavonoides/química , Folículo Piloso/fisiologia , Luteolina/química , Luteolina/farmacologia , Melanócitos/efeitos dos fármacos , Melanócitos/fisiologia , Camundongos Endogâmicos C57BL , Pele/efeitos dos fármacos , Relação Estrutura-Atividade
7.
Eur J Pharmacol ; 860: 172586, 2019 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-31377156

RESUMO

Resveratrol (3,5,4'-trihydroxy-trans-stilbene), has been reported to exert a variety of important pharmacological effects including anti-inflammatory, anticancer, and direct inhibition of tyrosinase. This study aimed to examine the expression of melanogenic molecules following down-regulation of cyclooxygenase (COX)-2 expression by resveratrol and the related signal transduction pathways in mouse B16F10 melanoma cells and zebrafish larvae. We report that resveratrol suppressed COX-2 in melanocytes and decreased the expressions of tyrosinase and microphthalmia-associated transcription factor (MITF). Furthermore, inhibition of COX-2 with NS398 enhanced resveratrol-reduced tyrosinase and MITF expression. Resveratrol also induced phosphorylation of extracellular signal-regulated 1/2 (ERK1/2) and phosphoinositide-3 (PI-3)-kinase/Akt. Inhibition of ERK1/2 or PI-3K/Akt by PD98059 and LY294002 restored the decreased tyrosinase activity and MITF expression via resveratrol-mediated down-regulation of COX-2. Additionally, resveratrol inhibited body pigmentation in zebrafish. These results indicated that resveratrol inhibited melanogenesis by down-regulating COX-2 via ERK1/2 and PI-3K/Akt pathways in B16F10 cells.


Assuntos
Ciclo-Oxigenase 2/metabolismo , Melaninas/biossíntese , Melanócitos/efeitos dos fármacos , Proteína Quinase 1 Ativada por Mitógeno/metabolismo , Proteína Quinase 3 Ativada por Mitógeno/metabolismo , Resveratrol/farmacologia , Transdução de Sinais/efeitos dos fármacos , Animais , Linhagem Celular Tumoral , Inibidores de Ciclo-Oxigenase 2/farmacologia , Melanócitos/citologia , Melanócitos/metabolismo , Camundongos , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo
8.
Molecules ; 24(16)2019 Aug 17.
Artigo em Inglês | MEDLINE | ID: mdl-31426477

RESUMO

Ginsenoside Ro (Ro), a major saponin derived and isolated from Panax ginseng C.A. Meyer, exerts multiple biological activities. However, the anti-tumour efficacy of Ro remains unclear because of its poor in vitro effects. In this study, we confirmed that Ro has no anti-tumour activity in vitro. We explored the anti-tumour activity of Ro in vivo in B16F10 tumour-bearing mice. The results revealed that Ro considerably suppressed tumour growth with no significant side effects on immune organs and body weight. Zingibroside R1, chikusetsusaponin IVa, and calenduloside E, three metabolites of Ro, were detected in the plasma of Ro-treated tumour-bearing mice and showed excellent anti-tumour effects as well as anti-angiogenic activity. The results suggest that the metabolites play important roles in the anti-tumour efficacy of Ro in vivo. Additionally, the haemolysis test demonstrated that Ro has good biocompatibility. Taken together, the findings of this study demonstrate that Ro markedly suppresses the tumour growth of B16F10-transplanted tumours in vivo, and its anti-tumour effects are based on the biological activity of its metabolites. The anti-tumour efficacy of these metabolites is due, at least in part, to its anti-angiogenic activity.


Assuntos
Inibidores da Angiogênese/farmacologia , Antineoplásicos Fitogênicos/farmacologia , Ginsenosídeos/farmacologia , Melanoma Experimental/tratamento farmacológico , Ácido Oleanólico/análogos & derivados , Saponinas/farmacologia , Neoplasias Cutâneas/tratamento farmacológico , Inibidores da Angiogênese/metabolismo , Inibidores da Angiogênese/farmacocinética , Animais , Antineoplásicos Fitogênicos/metabolismo , Antineoplásicos Fitogênicos/farmacocinética , Biotransformação , Ginsenosídeos/metabolismo , Ginsenosídeos/farmacocinética , Hemólise/efeitos dos fármacos , Melanócitos/efeitos dos fármacos , Melanócitos/patologia , Melanoma Experimental/patologia , Camundongos , Camundongos Endogâmicos C57BL , Transplante de Neoplasias , Ácido Oleanólico/metabolismo , Ácido Oleanólico/farmacocinética , Ácido Oleanólico/farmacologia , Panax/química , Extratos Vegetais/química , Saponinas/metabolismo , Saponinas/farmacocinética , Neoplasias Cutâneas/patologia
9.
J Microbiol Biotechnol ; 29(8): 1204-1211, 2019 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-31336432

RESUMO

Fungal exopolysaccharides are important natural products having diverse biological functions. In this study, exopolysaccharides from Fomitopsis castanea mycelia (FEPS) were prepared, and the highest mushroom tyrosinase inhibitory activity was found. FEPS were prepared from cultivation broth by ethanol precipitation method. The extraction yield and protein concentration of FEPS were 213.1 mg/l and 0.03%, respectively. FEPS inhibited mushroom tyrosinase with the half maximal inhibitory concentration (IC50) of 16.5 mg/ml and dose-dependently inhibited cellular tyrosinase activity (63.9% at 50 µg/ml, and 83.3% at 100 µg/ml) in the cell-free extract of SK-MEL-5 human melanoma cell and α-melanocytestimulating hormone (α-MSH)-stimulated melanin formation in intact SK-MEL-5 human melanoma cell. The IC50 of FEPS against NO production from RAW264.7 macrophage cells was 42.8 ± 0.64 µg/ml. By in vivo study using a zebrafish model, exposure of FEPS at 400 µg/ml to dechorionated zebrafish embryos for 18 h decreased the pigment density, compared to that without FEPS-treated control.


Assuntos
Coriolaceae/metabolismo , Polissacarídeos Fúngicos/antagonistas & inibidores , Polissacarídeos Fúngicos/metabolismo , Melanoma/tratamento farmacológico , Micélio/metabolismo , Agaricales/enzimologia , Animais , Linhagem Celular Tumoral/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Modelos Animais de Doenças , Polissacarídeos Fúngicos/isolamento & purificação , Humanos , Concentração Inibidora 50 , Melaninas/metabolismo , Melanócitos/efeitos dos fármacos , Melanoma Experimental , Camundongos , Monofenol Mono-Oxigenase/efeitos dos fármacos , Células RAW 264.7 , Peixe-Zebra , alfa-MSH/efeitos dos fármacos
10.
Colloids Surf B Biointerfaces ; 181: 270-277, 2019 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-31153022

RESUMO

It is very important to examine carefully the potential adverse effects of engineered nanoparticles (NPs) on human health and environments. In the present study, we have investigated the impact of interfacial serum proteins on the cell membrane disruption induced by silica NPs of primary diameter of 55-68 nm in four types of cells (erythrocytes, Jurkat, B16F10, and J774.1). The silica-induced membranolysis was repressed by addition of 1-2% serum into culture media, where the adhesion amount of the FBS-coated silica NPs onto a cell surface seemed comparable with that of the bare silica NPs. The nonspecific attraction between the bare silica and J774.1 cell membrane surfaces was masked by pretreatment of the silica surface with serum albumin, whereas the serum proteins-coated silica surface exhibited the attractive interactions with the cell membrane due to specific binding between some of adsorbed proteins thereon and the membrane receptors. The difference in silica-cell interaction between the nonspecific and specific attractions would explain the reason why interfacial serum proteins reduced the membranolysis without prevention of silica NPs adhering to cell surfaces.


Assuntos
Membrana Celular/efeitos dos fármacos , Nanopartículas/química , Soroalbumina Bovina/antagonistas & inibidores , Dióxido de Silício/farmacologia , Animais , Bovinos , Células Cultivadas , Eritrócitos/efeitos dos fármacos , Humanos , Células Jurkat , Linfócitos/efeitos dos fármacos , Macrófagos/efeitos dos fármacos , Melanócitos/efeitos dos fármacos , Tamanho da Partícula , Coelhos , Soroalbumina Bovina/química , Dióxido de Silício/química , Propriedades de Superfície
11.
Mater Sci Eng C Mater Biol Appl ; 102: 45-52, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31147016

RESUMO

Tyrosinase inhibitors could effectively limit the activity of tyrosinase in melanocytes to reduce the excessive synthesis and deposition of melanin. However, low skin permeability and lacking in targeting greatly restricted their application. Herein, ZnO quantum dots were synthesized by gel-sol method and grafted with BQ-788, which have been employed as transdermal and targeting carrier to delivery ellagic acid to melanocytes. Ellagic acid loaded ZnO quantum dots with the size distribution of around 9 nm could targetedly bind to melanocytes and enter the melanocytes by endocytosis within 1 h. The ellagic acid release behavior was controlled by the decreasing of pH via the rapid dissolution of ZnO. When the concentration of BQ-788/EA@ZnO was 12.5 µg/mL, the inhibition rate on tyrosinase activity and melanin deposition were up to 44.23 ±â€¯4.97% and 37.50 ±â€¯5.23%, respectively. In view of their good biocompatibility, they were of great potential in clinically external application for tyrosinase inhibition.


Assuntos
Ácido Elágico/química , Inibidores Enzimáticos/farmacologia , Melanócitos/enzimologia , Monofenol Mono-Oxigenase/antagonistas & inibidores , Oligopeptídeos/administração & dosagem , Oligopeptídeos/farmacologia , Piperidinas/administração & dosagem , Piperidinas/farmacologia , Pontos Quânticos/química , Óxido de Zinco/química , Administração Cutânea , Adulto , Materiais Biocompatíveis/farmacologia , Células Cultivadas , Preparações de Ação Retardada , Sistemas de Liberação de Medicamentos , Endocitose/efeitos dos fármacos , Humanos , Melaninas/metabolismo , Melanócitos/efeitos dos fármacos , Monofenol Mono-Oxigenase/metabolismo , Oligopeptídeos/síntese química , Oligopeptídeos/química , Piperidinas/síntese química , Piperidinas/química , Pontos Quânticos/ultraestrutura , Tirosina/metabolismo , Óxido de Zinco/síntese química
13.
Molecules ; 24(10)2019 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-31121831

RESUMO

Aminoacyl-tRNA synthetase complex-interacting multifunctional protein 1 (AIMP1)-derived peptide (AdP) has been developed as a cosmeceutical ingredient for skin anti-aging given its fibroblast-activating (FA) and melanocyte-inhibiting (MI) functions. However, a suitable strategy for the topical delivery of AdP was required due to its low-permeable properties. In this study, FA and MI domains of AdP (FA-AdP and MI-AdP, respectively) were determined by functional domain mapping, where the activities of several fragments of AdP on fibroblast and melanocyte were tested, and a hydrosol-based topical delivery system for these AdP fragments was prepared. The excipient composition of the hydrosol was optimized to maximize the viscosity and drying rate by using Box-Behnken design. The artificial skin deposition of FA-AdP-loaded hydrosol was evaluated using Keshary-Chien diffusion cells equipped with Strat-M membrane (STM). The quantification of the fluorescent dye-tagged FA-AdP in STM was carried out by near-infrared fluorescence imaging. The optimized hydrosol showed 127-fold higher peptide deposition in STM than free FA-AdP (p < 0.05). This work suggests that FA- and MI-AdP are active-domains for anti-wrinkle and whitening activities, respectively, and the hydrosol could be used as a promising cosmetic formulation for the delivery of AdPs to the skin.


Assuntos
Cosmecêuticos/farmacologia , Citocinas/química , Proteínas de Neoplasias/química , Peptídeos/farmacologia , Proteínas de Ligação a RNA/química , Envelhecimento da Pele/efeitos dos fármacos , Animais , Linhagem Celular , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Cosmecêuticos/química , Doxorrubicina , Humanos , Melanócitos/citologia , Melanócitos/efeitos dos fármacos , Melanócitos/metabolismo , Camundongos , Modelos Biológicos , Imagem Óptica , Peptídeos/química , Viscosidade
14.
Protein Pept Lett ; 26(12): 910-918, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31057097

RESUMO

BACKGROUND: Melanin plays a crucial role in camouflage, social communication and protection against harmful ultraviolet radiations. Melanin is synthesized by melanocytes through melanogenesis and several intrinsic and extrinsic factors are involved during the process. Any change occuring in the normal melanogenesis process can cause severe pigmentation problems of hypopigmentation or hyperpigmentation. OBJECTIVE: The present study is based on the evaluation of the effect of thymoquinone on melanogenesis and their possible mechanism of action using the B16F10 melanoma cell line for the production via blocking signaling pathways. METHODS: Phase contrast microscopy, cell viability, tyrosinase activity, melanin content and western blot analysis were used in the present study. RESULTS: In the present investigation, cultured melanocytes exhibit that the stimulation of melanin synthesis when treated with thymoquinone. Tyrosinase activity and melanin production in B16F10 melanoma cell line was increased in doze-dependent manner. In western blot, we investigated the involvement of the cAMP/PKA pathway in thymoquinone induced melanogenesis. It was observed protein kinase inhibitors PKA, PKC, PKB and MEK1 decreased the stimulatory effects of thymoquinone from 11.45- fold value to 8.312, 6.631, 4.51, and 7.211-fold value, respectively. However, the results also prove that thymoquinone may partially induce tyrosinase expression via PKA, PKB, PKC and MEK1 signaling pathways. CONCLUSION: The present finding proposed that thymoquinone is a protective challenger for melanogenesis and it might be useful for the treatment of hypopigmentary disorders.


Assuntos
Benzoquinonas/farmacologia , Melaninas/biossíntese , Melanócitos/efeitos dos fármacos , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Humanos , Melanócitos/citologia , Melanócitos/metabolismo , Melanoma Experimental , Monofenol Mono-Oxigenase/genética , Monofenol Mono-Oxigenase/metabolismo , Inibidores de Proteínas Quinases/farmacologia , Transdução de Sinais , Células Tumorais Cultivadas
15.
Int J Mol Sci ; 20(9)2019 Apr 27.
Artigo em Inglês | MEDLINE | ID: mdl-31035588

RESUMO

Melanogenesis is the sequential process of melanin production by melanocytes in order to protect the skin from harmful stimuli. Melanogenesis is disrupted by radiation exposure, which results in the differentiation of melanocytes into melanoma. Recently, some methods have been developed to maintain the instability of melanogenesis in melanoma by activating cellular autophagy. However, there is still a lack of knowledge about how autophagy is involved in the regulation of melanogenesis in melanoma cells. Here, we used rottlerin as an autophagy inducer to investigate the role of the cyclic adenosine monophosphate (cAMP)/cAMP response element binding (CREB) signaling pathway in melanogenesis. We found that rottlerin can inhibit melanin production by targeting cAMP, which is initially activated by alpha-melanocyte stimulating hormone (α-MSH). Our findings suggest that rottlerin has a pivotal role as an autophagy inducer in the regulation of melanogenesis by targeting the cAMP/CREB signaling pathway.


Assuntos
Acetofenonas/farmacologia , Autofagia/efeitos dos fármacos , Benzopiranos/farmacologia , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/metabolismo , AMP Cíclico/metabolismo , Melaninas/metabolismo , Acetofenonas/química , Animais , Benzopiranos/química , Linhagem Celular Tumoral , Melanócitos/efeitos dos fármacos , Melanócitos/metabolismo , Melanoma Experimental , Camundongos , Transdução de Sinais
16.
J Dermatol Sci ; 94(1): 213-219, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30956031

RESUMO

BACKGROUND: Fargesin is commonly used in the treatment of allergic rhinitis, inflammation, sinusitis and headache. OBJECTIVE: The aim of the study is to investigate a new function of fargesin against melanin production and its underlying molecular mechanism. METHODS: B16F10 mouse melanoma cells, Melan-a and human epidermal melanocytes were treated with different concentrations of fargesin for the indicated time. The extracellular and cellular melanin content was detected by spectrometry at 490 nm and 405 nm, respectively. RT-qPCR and Western blot analysis were used to exam the expression of melanogenic enzymes and the activities of PKA/CREB and p38 MAPK pathway components. Zebrafish was used as an in vivo model for studying the function of fargesin in regulating melanogenesis. RESULTS: Fargesin effectively inhibited melanin production at moderate dose in mouse B16F10 melanoma cells, normal melanocyte cell lines and zebrafish. The expression of microphthalmia-associated transcription factor (MITF), its downstream melanogenic enzymes and tyrosinase activity were also strongly reduced by fargesin. Moreover, the increase of melanin production induced by UVB and forskolin could be fully reversed by fargesin treatment. Fargesin also effectively inhibited the activation of PKA/CREB and p38 MAPK as well as their interactions, which in turn is responsible for the expression of MITF and melanogenic enzymes. CONCLUSIONS: These results show that fargesin can function as an anti-melanogenic agent, at least in part, by inhibiting PKA/CREB and p38/MAPK signaling pathways. Therefore, fargesin and its derivatives may potentially be used for preventing hyperpigmentation disorders in the future.


Assuntos
Benzodioxóis/farmacologia , Hiperpigmentação/tratamento farmacológico , Lignanas/farmacologia , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Melaninas/biossíntese , Melanócitos/efeitos dos fármacos , Animais , Benzodioxóis/uso terapêutico , Linhagem Celular Tumoral , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/metabolismo , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Avaliação Pré-Clínica de Medicamentos , Embrião não Mamífero , Humanos , Lignanas/uso terapêutico , Melanócitos/metabolismo , Camundongos , Modelos Animais , Peixe-Zebra
17.
J Dermatol Sci ; 94(1): 236-243, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30987854

RESUMO

BACKGROUND: Oxidative stress plays important roles in the pathogenesis of vitiligo. The removal of hydrogen peroxided (H2O2) has been established to be beneficial to vitiligo patients. Berberine (BBR), a natural isoquinoline alkaloid, has antioxidant activity, however, whether BBR can defend human melanocytes against oxidative injury remains to be elucidated. OBJECTIVE: In the present study, we investigated the potential protective effect of BBR against oxidative stress on an immortalized normal human melanocyte cell line PIG1. METHODS: Generally, PIG1 cells were pretreated with various concentrations of BBR for 1 h followed by exposure to 1.0 mM H2O2 for 24 h. Cell apoptosis, intracellular reactive oxygen species (ROS) levels were assessed through flow cytometry. Cell apoptosis, melanogenesis and the activation of Nrf2-ARE and Mitf signaling pathway were assayed. RESULTS: Our results showed that cell viability rose and intracellular ROS generation, cell apoptosis of melanocytes decreased significantly in response to H2O2 through pretreatment with BBR. Furthermore, We found that BBR can dramatically induce Nrf2 nuclear translocation, increase total Nrf2 levels and enhance ARE activity. Besides, Nrf2-siRNA transfection can abrogate the protection of BBR in melanocytes against oxidative injury. At last, we verified that BBR could facilitate melanogenesis function via modulation of Mitf and its target proteins. CONCLUSION: The results above suggest that BBR can protect melanocytes against oxidative stress via its anti-oxidative activity. Also, we found H2O2-induced activation of NFκB was inhibited by BBR. Therefore, it is worthy of investigation BBR as a potential drug for treatment of vitiligo.


Assuntos
Berberina/farmacologia , Melanócitos/efeitos dos fármacos , Vitiligo/tratamento farmacológico , Berberina/uso terapêutico , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Avaliação Pré-Clínica de Medicamentos , Humanos , Peróxido de Hidrogênio/toxicidade , Melaninas/biossíntese , Melanócitos/metabolismo , Fator de Transcrição Associado à Microftalmia/metabolismo , Fator 2 Relacionado a NF-E2/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Vitiligo/patologia
18.
Biomed Res Int ; 2019: 5971546, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31008108

RESUMO

It has long been believed that histamine is associated with cutaneous melanogenesis. Specifically, H2-receptor antagonists reportedly inhibit melanogenesis, but H1-receptor antagonists, which are some of the most commonly prescribed medicines in dermatology, have not been studied to determine whether and how they regulate melanogenesis. Therefore, we screened H1-receptor antagonists to determine whether they inhibit melanogenesis and found that loratadine was particularly effective, in this regard without compromising cellular viability. Loratadine downregulated microphthalmia-associated transcription factor (MITF) and tyrosinase in melanocytes. To determine the intracellular signaling pathways, Akt was consistently activated by loratadine. PI3K/Akt pathway inhibitor, LY294002, restored the reduced melanin content that was induced by loratadine. In addition, phospho-GSK-3ß also was found to be increased following loratadine treatment. Loratadine reduced the amount of PKC-ßII in the membrane fraction, thereby decreasing its activity. Taken together, our data indicate that loratadine regulates melanogenesis via Akt/MITF and PKC-ßII signaling, thereby leading to the inhibition of melanogenic proteins. The antimelanogenic effects of loratadine have potentially significant and useful roles in dermatologic practice, although further clinical studies will be required to test this.


Assuntos
Antagonistas dos Receptores Histamínicos H1/farmacologia , Loratadina/farmacologia , Melaninas/biossíntese , Receptores Histamínicos H1/genética , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Cromonas/farmacologia , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Melaninas/genética , Melanócitos/efeitos dos fármacos , Melanócitos/metabolismo , Fator de Transcrição Associado à Microftalmia/genética , Morfolinas/farmacologia , Fosfatidilinositol 3-Quinases/metabolismo , Proteína Quinase C beta/genética , Proteína Quinase C beta/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transdução de Sinais/efeitos dos fármacos
19.
Int J Mol Sci ; 20(4)2019 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-30813264

RESUMO

Melanin is produced in melanocytes and stored in melanosomes, after which it is transferred to keratinocytes and, thus, determines skin color. Despite its beneficial sun-protective effects, abnormal accumulation of melanin results in esthetic problems. A range of topical hypopigmenting agents have been evaluated for their use in the treatment of pigmentary disorders with varying degrees of success. Hydroquinone (HQ), which competes with tyrosine, is the main ingredient in topical pharmacological agents. However, frequent occurrence of adverse reactions is an important factor that limits its use. Thus, efforts to discover effective topical hypopigmenting agents with less adverse effects continue. Here, we describe the potential of resveratrol to function as an effective hypopigmenting agent based on its mechanism of action. Resveratrol is not only a direct tyrosinase inhibitor but an indirect inhibitor as well. Additionally, it can affect keratinocytes, which regulate the function of melanocytes. Resveratrol regulates the inflammatory process of keratinocytes and protects them from oxidative damage. In this way, it prevents keratinocyte-induced melanocyte stimulation. Furthermore, it has a rescuing effect on the stemness of interfollicular epidermal cells that can repair signs of photoaging in the melasma, a typical pigmentary skin disorder. Overall, resveratrol is a promising potent hypopigmenting agent.


Assuntos
Hipopigmentação/tratamento farmacológico , Resveratrol/administração & dosagem , Resveratrol/uso terapêutico , Administração Tópica , Animais , Humanos , Queratinócitos/efeitos dos fármacos , Queratinócitos/patologia , Melanócitos/efeitos dos fármacos , Melanócitos/patologia , Melanoma/tratamento farmacológico , Melanoma/patologia , Resveratrol/farmacologia
20.
J Vis Exp ; (145)2019 03 06.
Artigo em Inglês | MEDLINE | ID: mdl-30907884

RESUMO

This study presents laboratory methods for the quantification of hypopigmentation activity in vitro. Melanin, the major pigment in melanocytes, is synthesized in response to multiple cellular and environmental factors. Melanin protects skin cells from ultraviolet damage, but also has biophysical and biochemical functions. Excessive production or accumulation of melanin in melanocytes can cause dermatological problems, such as freckles, dark spots, melasma, and moles. Therefore, the control of melanogenesis with hypopigmentation agents is important in individuals with clinical or cosmetic needs. Melanin is primarily synthesized in the melanosomes of melanocytes in a complex biochemical process called melanogenesis, which is influenced by extrinsic and intrinsic factors, such as hormones, inflammation, age, and ultraviolet light exposure. We describe three methods to determine the hypopigmentation activity of chemicals or natural substances in melanocytes: measurement of the 1) cellular tyrosinase activity and 2) melanin content, and 3) staining and quantifying cellular melanin with image analysis. In melanogenesis, tyrosinase catalyzes the rate-limiting step that converts L-tyrosine into 3,4-dihydroxyphenylalanine (L-DOPA) and then into dopaquinone. Therefore, the inhibition of tyrosinase is a primary hypopigmentation mechanism. In cultured melanocytes, tyrosinase activity can be quantified by adding L-DOPA as a substrate and measuring dopaquinone production by spectrophotometry. Melanogenesis can also be measured by quantifying the melanin content. The melanin-containing cellular fraction is extracted with NaOH and melanin is quantified spectrophotometrically. Finally, the melanin content can be quantified by image analysis following Fontana-Masson staining of melanin. Although the results of these in vitro assays may not always be reproduced in human skin, these methods are widely used in melanogenesis research, especially as the initial step to identify potential hypopigmentation activity. These methods can also be used to assess melanocyte activity, growth, and differentiation. Consistent results with the three different methods ensure the validity of the effects.


Assuntos
Hipopigmentação/diagnóstico , Animais , Arbutina/farmacologia , Humanos , Melaninas/biossíntese , Melanócitos/efeitos dos fármacos , Melanócitos/metabolismo , Melanócitos/patologia , Tirosina/metabolismo
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