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1.
J Tradit Chin Med ; 41(3): 355-359, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-34114391

RESUMO

OBJECTIVE: To investigate the efficacy of horse oil on lipopolysaccharide (LPS)-induced inflammation in human keratinocytes. METHODS: Western blot analysis was performed to measure the expression of cyclooxygenase-2 (COX-2) and IκBα. ELISA was used to analyze prostaglandin E2 (PGE2) levels. RESULTS: Horse oil decreased LPS-induced COX-2 and PGE2 levels in a dose-dependent manner. Nuclear factor-kappa B (NF-κB) plays a key role in the expression of inflammatory cytokines and mediators. Therefore, we investigated the influence of horse oil on the NF-κB signaling pathways. Horse oil inhibited translocation of NF-κB from the cytosol to the nucleus. Furthermore, LPS-induced degradation of IκBα was recovered by horse oil. The activation of p38 mitogen-activated protein kinase (MAPK) reportedly induces degradation of IκBα In agreement with this, LPS activated p38 MAPK and caused IκBα degradation. Conversely, horse oil inhibited LPS-induced p38 MAPK activation and IκBα degradation. In addition, a specific p38 MAPK inhibitor, SB203580, blocked IκBα degradation. CONCLUSION: Horse oil decreased COX-2 and PGE2 by inhibiting p38 MAPK activation, IκBα degradation, and the translocation of NF-κB.


Assuntos
Lipopolissacarídeos , NF-kappa B , Animais , Cavalos , Humanos , Inflamação/tratamento farmacológico , Inflamação/genética , Queratinócitos , NF-kappa B/genética , Óxido Nítrico , Proteínas Quinases p38 Ativadas por Mitógeno/genética
2.
Exp Dermatol ; 27(11): 1224-1229, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30091803

RESUMO

Leucine-rich repeat LGI family member 3 (LGI3), a member of the LGI family, is a secreted protein that is expressed not only in the brain and adipose tissues, but also in various skin cells. We previously reported that LGI3 was secreted after exposure to ultraviolet B and promoted the migration of HaCaT human keratinocytes. In the present study, we investigated whether LGI3 influences the differentiation of keratinocytes. The results show that the expression of involucrin, a keratinocyte differentiation marker, was reduced in tissue from LGI3-knockout mice. Those results indicate that LGI3 plays an important role in keratinocyte differentiation. Therefore, we treated HaCaT cells with LGI3 to examine its effect on keratinocyte differentiation. Protein levels of various differentiation markers were enhanced by treatment with LGI3. Furthermore, expression of differentiation markers was inhibited when keratinocytes were transfected with an siRNA for LGI3. LGI3 strongly activated Akt, whereas it had no apparent effect on extracellular signal-regulated kinase, p38 mitogen-activated protein kinase, or the c-Jun N-terminal kinase. A specific inhibitor of phosphoinositide 3-kinase, LY294002, reduced LGI3-induced expression of differentiation markers in HaCaT cells. Taken together, these results suggest that LGI3 promotes keratinocyte differentiation and could be used as a therapeutic agent to recover skin barrier function in epidermal barrier disruption.


Assuntos
Diferenciação Celular/efeitos dos fármacos , Queratinócitos/fisiologia , Proteínas do Tecido Nervoso/genética , Proteínas/farmacologia , Proteínas Proto-Oncogênicas c-akt/metabolismo , Animais , Diferenciação Celular/genética , Linhagem Celular , Cromonas/farmacologia , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Feminino , Expressão Gênica/efeitos dos fármacos , Humanos , Proteínas Quinases JNK Ativadas por Mitógeno/metabolismo , Sistema de Sinalização das MAP Quinases , Camundongos Knockout , Morfolinas/farmacologia , Precursores de Proteínas/genética , Precursores de Proteínas/metabolismo , Proteínas/genética , RNA Interferente Pequeno/farmacologia , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo
3.
J Tissue Viability ; 27(2): 117-121, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29428186

RESUMO

Since the use of animal experimentation is restricted with regard to cosmetic materials, alternative in vitro models such as skin equivalents (SEs) are needed. Laminin is one of the major non-collagenous glycoproteins. The pentapeptide YIGSR (Tyr-Ile-Gly-Ser-Arg) is a functional motif of laminin that binds to the laminin receptor. In the present study, we examined whether YIGSR could improve the reconstruction of SEs. YIGSR has no effects on monolayer cell proliferation of CCD25-Sk fibroblasts or HaCaT keratinocytes. Interestingly, YIGSR decreased TGF-ß1 levels, although it promoted type Ι collagen synthesis in CCD25-Sk cells. In HaCaT cells, YIGSR decreased the expression of involucrin and loricrin, which are differentiation markers. Furthermore, YIGSR increased levels of proliferating cell nuclear antigen (PCNA), p63, and integrin α6, and decreased involucrin in SE models. In addition, two models containing YIGSR (mixed with dermal equivalents or added into media) did not show any differences in expression levels of PCNA, p63, integrin α6, and involucrin. Therefore, YIGSR is a useful agent for reconstruction of SEs, independent of its method of application. These results indicate that YIGSR stimulates epidermal proliferation and basement membrane formation while inhibiting keratinocyte differentiation of SEs. Taken together, these results indicate that YIGSR promotes the reconstruction of SEs, potentially via decreased TGF-ß1 levels and consequent inhibition of epidermal differentiation.


Assuntos
Biomimética/normas , Laminina/biossíntese , Oligopeptídeos/biossíntese , Pele/patologia , Fibroblastos/patologia , Humanos , República da Coreia
4.
Biomed Pharmacother ; 92: 122-127, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28535415

RESUMO

Punicalagin is a phenolic compound with antioxidant properties. However, the effects of punicalagin on melanin synthesis have been poorly evaluated. Therefore, we investigated the effects of punicalagin on melanogenesis in Mel-Ab cells. Punicalagin significantly inhibited melanin synthesis in a dose-dependent manner. In accordance with the melanin content, punicalagin also dose-dependently decreased tyrosinase activity. Punicalagin did not directly inhibit tyrosinase in a cell-free system but did downregulate the expression of microphthalmia-associated transcription factor (MITF) and tyrosinase. Therefore, we examined the effects of punicalagin on melanogenesis-related signaling pathways. Punicalagin induced extracellular signal-regulated kinase (ERK) and Akt phosphorylation but had no effect on ß-catenin level. We measured melanin content and MITF expression in the presence of the ERK pathway inhibitor PD98059 and/or the Akt pathway inhibitor LY294002. Cotreatment with PD98059 and LY294002 almost completely restored punicalagin-induced hypopigmentation. These data indicate that punicalagin inhibits melanin synthesis through ERK and Akt phosphorylation, with subsequent downregulation of MITF and tyrosinase.


Assuntos
Antioxidantes/toxicidade , Taninos Hidrolisáveis/toxicidade , Hipopigmentação/tratamento farmacológico , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Melanócitos/efeitos dos fármacos , Inibidores de Proteínas Quinases/farmacologia , Proteínas Proto-Oncogênicas c-akt/antagonistas & inibidores , Animais , Linhagem Celular Transformada , Cromonas/farmacologia , Inibidores Enzimáticos/farmacologia , Flavonoides/farmacologia , Hipopigmentação/induzido quimicamente , Hipopigmentação/metabolismo , Hipopigmentação/patologia , Cinética , Melaninas/agonistas , Melaninas/antagonistas & inibidores , Melaninas/biossíntese , Melanócitos/metabolismo , Melanócitos/patologia , Camundongos , Fator de Transcrição Associado à Microftalmia/agonistas , Fator de Transcrição Associado à Microftalmia/antagonistas & inibidores , Fator de Transcrição Associado à Microftalmia/metabolismo , Microscopia de Contraste de Fase , Monofenol Mono-Oxigenase/antagonistas & inibidores , Monofenol Mono-Oxigenase/química , Monofenol Mono-Oxigenase/metabolismo , Morfolinas/farmacologia , Fosforilação/efeitos dos fármacos , Processamento de Proteína Pós-Traducional/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-akt/metabolismo
5.
Biomed Pharmacother ; 82: 15-9, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27470333

RESUMO

The aim of this study was to test the anti-cancer effects of geranylgeranylacetone (GGA), an isoprenoid compound, on human melanoma cells. Human melanoma cell lines G361, SK-MEL-2, and SK-MEL-5 were treated with GGA at various doses (1-100µM). Cell viability was measured by crystal violet assay. Western blot analysis was adopted to detect marker proteins of apoptosis. GGA significantly reduced the viability of G361, SK-MEL-2, and SK-MEL-5 human melanoma cells at concentrations above 10µM. Western blot analysis showed the phosphorylation of p38 MAPK and c-Jun N-terminal kinase (JNK) after GGA treatment, as well as activation of caspase-9, caspase-3, and poly(ADP-ribose) polymerase (PARP) cleavage. GGA also induced p53 and Bax expression, but did not affect expression of Bcl-2 and MITF. These findings suggest that GGA induces apoptosis through the intrinsic pathway. Accordingly, GGA should be considered for further development as a potential agent for melanoma.


Assuntos
Apoptose/efeitos dos fármacos , Diterpenos/farmacologia , Melanoma/patologia , Transdução de Sinais/efeitos dos fármacos , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Humanos , Proteínas Quinases JNK Ativadas por Mitógeno/metabolismo , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Melanoma/enzimologia , Proteína Supressora de Tumor p53/metabolismo , Proteína X Associada a bcl-2/metabolismo , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo
6.
Pharmazie ; 70(10): 646-9, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26601420

RESUMO

Here we examined the effects of a DNA methylation inhibitor, 5-azacytidine, on melanogenesis in Mel-Ab cells. We found that 5-azacytidine decreased the melanin content and tyrosinase activity in these cells in a dose-dependent manner; importantly, 5-azacytidine was not cytotoxic at the concentrations used in these experiments. On the other hand, 5-azacytidine did not affect tyrosinase activity in a cell-free system, indicating that 5-azacytidine is not a direct tyrosinase inhibitor. Instead, 5-azacytidine decreased the protein levels of microphthalmia-associated transcription factor (MITF) and tyrosinase. Thus, we investigated the effects of 5-azacytidine on signal transduction pathways related to melanogenesis. However, 5-azacytidine did not have any effect on either Akt or glycogen synthase kinase 3ß (GSK3ß) phosphorylation. The phosphorylation of cAMP response element-binding protein (CREB) is well known to regulate MITF expression, thereby also regulating tyrosinase expression. We found that 5-azacytidine decreased the phosphorylation of CREB. Therefore, we propose that 5-azacytidine may decrease melanin synthesis by downregulating MITF and tyrosinase via CREB inactivation.


Assuntos
Antimetabólitos Antineoplásicos/farmacologia , Azacitidina/farmacologia , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/metabolismo , Metilação de DNA/efeitos dos fármacos , Melaninas/biossíntese , Linhagem Celular , AMP Cíclico , Melanócitos/efeitos dos fármacos , Melanócitos/metabolismo , Monofenol Mono-Oxigenase/metabolismo , Fosforilação/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos
7.
Eur J Pharmacol ; 761: 19-27, 2015 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-25934572

RESUMO

Scutellaria baicalensis has been used topically to treat inflammatory skin diseases in traditional East Asian medicine. Because post-inflammatory hyperpigmentation of the skin is difficult to manage, we investigated the effects of baicalin, a major component of S. baicalensis, on melanin synthesis in Mel-Ab cells. Our data showed that baicalin significantly inhibited melanin production and tyrosinase activity in a dose-dependent fashion, but it did not directly influence tyrosinase activity. Moreover, baicalin treatment triggered decreases in both mRNA and protein levels of microphthalmia-associated transcription factor (MITF) and tyrosinase. Although AMP-activated protein kinase (AMPK) and extracellular signal-regulated kinase (ERK) activation were induced in baicalin-treated Mel-Ab cells, they were not responsible for baicalin-induced hypopigmentation. Because the Akt pathway is also known to be involved in regulation of melanogenic protein expression and melanin synthesis, we examined the effects of baicalin on the Akt pathway. Our results showed that baicalin treatment stimulated Akt activation. Treatment with LY294002, a specific Akt inhibitor, restored baicalin-induced melanogenesis inhibition and abolished MITF and tyrosinase downregulation by baicalin. Taken together, our data suggest that Akt activation by baicalin inhibits melanin production via downregulation of MITF and tyrosinase in Mel-Ab cells.


Assuntos
Flavonoides/farmacologia , Melaninas/biossíntese , Melanócitos/efeitos dos fármacos , Fator de Transcrição Associado à Microftalmia/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Animais , Linhagem Celular , Relação Dose-Resposta a Droga , Regulação para Baixo , Ativação Enzimática , Melanócitos/enzimologia , Camundongos , Monofenol Mono-Oxigenase/metabolismo , Fosfatidilinositol 3-Quinase/metabolismo , Inibidores de Proteínas Quinases/farmacologia , Proteínas Proto-Oncogênicas c-akt/antagonistas & inibidores , Transdução de Sinais/efeitos dos fármacos , Fatores de Tempo
8.
Pharmazie ; 70(1): 55-9, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25975099

RESUMO

Methyl gallate (MG) was isolated from the bark of Acer barbinerve, which has traditionally been used in Oriental medicine. In the present study, we examined the effects of MG on melanin synthesis in Mel-Ab melanocyte cells. MG decreased melanin pigmentation in a concentration-dependent manner, but did not directly inhibit tyrosinase activity. Further analysis showed that MG had no effect on extracellular signal-regulated kinase (ERK) activation, but induced phosphorylation of glycogen synthase kinase (GSK)3ß, which is known to increase ß-catenin accumulation. Accordingly, the ß-catenin level was increased by MG. However, a specific GSK3ß inhibitor did not rescue the MG-induced inhibition of melanogenesis. Additionally, MG decreased the protein expression of microphthalmia-associated transcription factor (MITF) and tyrosinase, which regulate melanin synthesis. Based on these results, we conclude that MG inhibits melanogenesis by decreasing the expression of MITF and tyrosinase.


Assuntos
Acer/química , Ácido Gálico/análogos & derivados , Melaninas/antagonistas & inibidores , Melaninas/biossíntese , Animais , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Ácido Gálico/farmacologia , Camundongos , Monofenol Mono-Oxigenase/metabolismo , Pigmentação/efeitos dos fármacos , Casca de Planta/química , Transdução de Sinais/efeitos dos fármacos
9.
Korean J Physiol Pharmacol ; 18(3): 249-54, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24976765

RESUMO

The purpose of this study is to characterize the effects of KHG26792 (3-(naphthalen-2-yl(propoxy) methyl)azetidine hydrochloride), a potential skin whitening agent, on melanin synthesis and identify the underlying mechanism of action. Our data showed that KHG26792 significantly reduced melanin synthesis in a dose-dependent manner. Additionally, KHG26792 downregulated microphthalmia-associated transcription factor (MITF) and tyrosinase, the rate-limiting enzyme in melanogenesis, although tyrosinase was not inhibited directly. KHG26792 activated extracellular signal-regulated kinase (ERK), whereas an ERK pathway inhibitor, PD98059, rescued KHG26792-induced hypopigmentation. These results suggest that KHG26792 decreases melanin production via ERK activation. Moreover, the hypopigmentary effects of KHG26792 were confirmed in a pigmented skin equivalent model using Cervi cornus Colla (deer antler glue), in which the color of the pigmented artificial skin became lighter after treatment with KHG26792. In summary, our findings suggest that KHG26792 is a novel skin whitening agent.

10.
Exp Dermatol ; 23(8): 600-2, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24903553

RESUMO

Recently, we demonstrated that leucine-rich glioma inactivated 3 (LGI3) is expressed in human skin. However, the effects of LGI3 on melanocytes remain unknown. The present study demonstrated that LGI3 can serve to stimulate melanogenesis without affecting cell viability. To determine the effects of LGI3 on melanin synthesis, normal human melanocytes and Mel-Ab cells were treated with recombinant LGI3 and melanin content was measured. Our results showed that LGI3 promoted melanin synthesis in both cell types. Moreover, upregulation of microphthalmia-associated transcription factor (MITF) and tyrosinase was observed at both the mRNA and protein levels via RT-PCR and Western blotting, respectively. Furthermore, immunohistochemical staining showed that the expression of LGI3 increased in the basal layer of melasma skin samples, whereas it decreased slightly in vitiligo samples. These results suggest that LGI3 may play a role as a melanogenic cytokine in human skin.


Assuntos
Citocinas/farmacologia , Melaninas/metabolismo , Proteínas/farmacologia , Pele/efeitos dos fármacos , Pele/metabolismo , Animais , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Citocinas/metabolismo , Humanos , Melanócitos/efeitos dos fármacos , Melanócitos/metabolismo , Melanócitos/patologia , Camundongos , Fator de Transcrição Associado à Microftalmia/metabolismo , Modelos Animais , Monofenol Mono-Oxigenase/metabolismo , Proteínas do Tecido Nervoso , Proteínas/metabolismo , Pele/patologia , Regulação para Cima/efeitos dos fármacos
11.
Acta Pharmacol Sin ; 35(4): 489-95, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24562306

RESUMO

AIM: To investigate the effects of docosahexaenoic acid (DHA) on melanin synthesis and related regulatory mechanisms. METHODS: B16F10 mouse melanoma cells were exposed to DHA for 3 d, and melanin content and tyrosinase activity were measured. Western blot analysis was used to analyze the protein levels in DHA-mediated signal transduction pathways. RESULTS: DHA (1-25 µmol/L) did not affect the viability of B16F10 cells, but decreased α-MSH-induced melanin synthesis in a concentration-dependent manner. DHA concentration-dependently reduced tyrosinase activity in the cells, but did not affect mushroom tyrosinase activity in a cell-free system. Furthermore, DHA treatment significantly reduced tyrosinase level without affecting microphthalmia-associated transcription factor (MITF) in the cells. DHA did not activate ERK and Akt in the cells. Pretreatment with the proteasome inhibitor MG132 (80 nmol/L) abolished DHA-induced tyrosinase reduction. CONCLUSION: DHA inhibits melanogenesis in B16F10 cells in vitro through increasing tyrosinase degradation. The results suggest that DHA may be a potential agent for treatment of hyperpigmentary disorders of skin.


Assuntos
Ácidos Docosa-Hexaenoicos/farmacologia , Melaninas/biossíntese , Melanoma Experimental/enzimologia , Monofenol Mono-Oxigenase/metabolismo , Neoplasias Cutâneas/enzimologia , Animais , Linhagem Celular Tumoral , Relação Dose-Resposta a Droga , Regulação para Baixo , Melanoma Experimental/patologia , Camundongos , Fator de Transcrição Associado à Microftalmia/metabolismo , Complexo de Endopeptidases do Proteassoma/metabolismo , Inibidores de Proteassoma/farmacologia , Proteólise , Transdução de Sinais/efeitos dos fármacos , Neoplasias Cutâneas/patologia , Pigmentação da Pele/efeitos dos fármacos , Fatores de Tempo , alfa-MSH/metabolismo
12.
Biol Pharm Bull ; 36(9): 1503-8, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23995664

RESUMO

Okadaic acid is a C38 fatty acid derivative that is known to specifically inhibit the activity of protein phosphatase 2A (PP2A). Previously, we reported that inhibition of PP2A by okadaic acid elicited extracellular signal-regulated kinase (ERK) activation, and that PP2A may be involved in melanogenesis. However, the effects of okadaic acid on melanogenesis have not been completely evaluated. In the present study, we investigated the molecular mechanisms involved in okadaic acid modulation of melanin synthesis in a spontaneously immortalized mouse melanocyte cell line, Mel-Ab. Treatment with okadaic acid inhibited melanin production in a dose-dependent manner. Moreover, okadaic acid led to a decrease in tyrosinase protein levels without altering mRNA expression. Therefore, we investigated whether the decreased level of tyrosinase by okadaic acid was related to proteasomal degradation of tyrosinase. We found that MG132, a proteasome inhibitor, almost completely abolished both the downregulation of tyrosinase levels and the inhibition of melanin synthesis by okadaic acid. Taken together, our data indicate that okadaic acid inhibits melanin synthesis via proteasomal degradation of tyrosinase.


Assuntos
Melaninas/antagonistas & inibidores , Monofenol Mono-Oxigenase/metabolismo , Ácido Okadáico/farmacologia , Complexo de Endopeptidases do Proteassoma/metabolismo , Animais , Linhagem Celular , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Quinase 3 da Glicogênio Sintase/metabolismo , Glicogênio Sintase Quinase 3 beta , Melaninas/metabolismo , Melanócitos , Camundongos , Monofenol Mono-Oxigenase/genética , RNA Mensageiro/metabolismo
13.
Life Sci ; 93(5-6): 226-32, 2013 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-23792203

RESUMO

AIMS: Geranylgeranylacetone (GGA) has shown cytoprotective activity through induction of a 70-kDa heat shock protein (HSP70). Although HSP70 is reported to regulate melanogenesis, the effects of GGA on melanin synthesis in melanocytes have not been previously studied. Therefore, this study investigated the effects of GGA on melanogenesis and the related signaling pathways. MAIN METHODS: Melanin content and tyrosinase activities were measured in Mel-Ab cells. GGA-induced signal transduction pathways were investigated by western blot analysis. KEY FINDINGS: Our results showed that GGA significantly decreased melanin content in a concentration-dependent manner. Similarly, GGA reduced tyrosinase activity dose-dependently, but it did not directly inhibit tyrosinase. Western blot analysis indicated that GGA downregulated microphthalmia-associated transcription factor (MITF) and tyrosinase protein expression, whereas it increased the phosphorylation of extracellular signal-regulated kinase (ERK) and mammalian target of rapamycin (mTOR). Furthermore, a specific ERK pathway inhibitor, PD98059, blocked GGA-induced melanin reduction and then prevented downregulation of MITF and tyrosinase by GGA. However, a specific mTOR inhibitor, rapamycin, only slightly restored inhibition of melanin production by GGA, indicating that mTOR signaling is not a key mechanism regulating the inhibition of melanin production. SIGNIFICANCE: These findings suggest that activation of ERK by GGA reduces melanin synthesis in Mel-Ab cells through downregulation of MITF and tyrosinase expression.


Assuntos
Antineoplásicos/farmacologia , Diterpenos/farmacologia , MAP Quinases Reguladas por Sinal Extracelular/fisiologia , Melaninas/antagonistas & inibidores , Melaninas/biossíntese , Melanócitos/efeitos dos fármacos , Melanócitos/enzimologia , Transdução de Sinais/efeitos dos fármacos , Animais , Linhagem Celular Transformada , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/fisiologia , Relação Dose-Resposta a Droga , Regulação para Baixo/efeitos dos fármacos , Regulação para Baixo/fisiologia , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Melanócitos/patologia , Camundongos , Transdução de Sinais/fisiologia
14.
Mol Cell Biochem ; 375(1-2): 81-7, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23203344

RESUMO

A few types of ceramide are reported to decrease melanin synthesis. In the present study, we examined the effects of an artificial ceramide analog, PC102, on melanogenesis using a spontaneously immortalized melanocyte cell line (Mel-Ab). PC102 is currently used as a moisturizing additive in a variety of cosmetics. Our data showed that PC102 inhibited melanin production and tyrosinase activity in a dose-dependent manner, but did not directly affect tyrosinase activity. Microphthalmia-associated transcription factor (MITF), tyrosinase, and ß-catenin protein levels decreased after 48 h of PC102 treatment. In contrast, PC102 did not decrease MITF, tyrosinase, and ß-catenin mRNA levels. Therefore, we investigated whether the decrease in MITF and tyrosinase by PC102 is due to proteasomal degradation. MG132, a proteasomal inhibitor, completely abolished tyrosinase downregulation due to PC102 and partially reduced the downregulation of MITF and ß-catenin due to PC102. Moreover, MG132 abrogated the inhibition of melanin synthesis by PC102. Taken together, our data suggest that PC102 may inhibit melanin synthesis through MITF and tyrosinase degradation.


Assuntos
Amidas/farmacologia , Melaninas/biossíntese , Fator de Transcrição Associado à Microftalmia/metabolismo , Monofenol Mono-Oxigenase/metabolismo , Propanolaminas/farmacologia , Complexo de Endopeptidases do Proteassoma/metabolismo , Animais , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Cosméticos/farmacologia , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Expressão Gênica/efeitos dos fármacos , Quinase 3 da Glicogênio Sintase/metabolismo , Glicogênio Sintase Quinase 3 beta , Leupeptinas/farmacologia , Camundongos , Monofenol Mono-Oxigenase/genética , Inibidores de Proteassoma/farmacologia , Proteólise , Transdução de Sinais , beta Catenina/genética , beta Catenina/metabolismo
15.
Arch Dermatol Res ; 305(1): 85-89, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23011660

RESUMO

The aim of this study was to investigate the effects of Cervi cornus Colla (CCC) in the reconstruction of skin equivalent (SE). H&E staining showed that SE containing hyaluronic acid (HA) or HA and CCC had a thicker epidermis than the control SE. Immunohistochemical staining showed that p63 was mainly present at the basal layer of the epidermis in the HA and CCC model. Involucrin was obviously expressed in the upper layer of the epidermis in the HA and CCC model. Moreover, we observed that integrins α6 and ß1 were strongly expressed along the basement membrane zone in the HA and CCC model, in which the dermis expressing type I collagen was more compact. In conclusion, our data indicate that CCC contributed to the formation of epidermis, basement membrane, and extracellular matrix in the reconstruction of SE and suggest that CCC may be a useful adjuvant in the reconstruction of SE.


Assuntos
Chifres de Veado/química , Cervos , Derme/efeitos dos fármacos , Engenharia Tecidual/métodos , Extratos de Tecidos/farmacologia , Animais , Membrana Basal/efeitos dos fármacos , Membrana Basal/metabolismo , Linhagem Celular , Técnicas de Cocultura , Colágeno Tipo I/metabolismo , Derme/citologia , Derme/metabolismo , Epiderme/efeitos dos fármacos , Epiderme/metabolismo , Humanos , Ácido Hialurônico/farmacologia , Imuno-Histoquímica , Integrina alfa6/metabolismo , Integrina beta1/metabolismo , Extratos de Tecidos/isolamento & purificação , Fatores de Transcrição/metabolismo , Proteínas Supressoras de Tumor/metabolismo
16.
Exp Dermatol ; 21(9): 716-8, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22741557

RESUMO

Leucine-rich glioma inactivated 3 (LGI3) is known to be expressed mainly in the brain. However, the expression and physiological roles of LGI3 in skin cells remain unknown. In this study, it was found for the first time that LGI3 is expressed mostly by normal human keratinocytes. Furthermore, ELISA analysis showed that HaCaT human keratinocytes increased LGI3 secretion after exposure to ultraviolet B (UVB) in a time- and dose-dependent manner. We next investigated the possible role of LGI3 in keratinocytes. LGI3 (50 ng/ml) increased survival of HaCaT cells by 20% after UVB irradiation (150 mJ/cm(2) ). It was also found that LGI3 stimulates the phosphorylation of Akt, which is involved in the cell survival-signalling cascade. Furthermore, LGI3 led to the phosphorylation of MDM2 and subsequent p53 degradation. Taken together, the data suggest that LGI3 may regulate p53 levels and that keratinocyte-derived LGI3 may act as a novel cytokine for skin homoeostasis.


Assuntos
Queratinócitos/metabolismo , Proteínas/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Proteínas Proto-Oncogênicas c-mdm2/metabolismo , Proteína Supressora de Tumor p53/metabolismo , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Relação Dose-Resposta à Radiação , Humanos , Queratinócitos/efeitos dos fármacos , Queratinócitos/efeitos da radiação , Proteínas do Tecido Nervoso , Fosforilação/efeitos dos fármacos , Proteínas/farmacologia , Proteínas/efeitos da radiação , Proteínas Proto-Oncogênicas c-akt/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-mdm2/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Fatores de Tempo , Proteína Supressora de Tumor p53/efeitos dos fármacos , Raios Ultravioleta
17.
Mol Cell Biochem ; 367(1-2): 43-9, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22544520

RESUMO

Activation of extracellular signal-related kinase (ERK) is involved in decreased melanogenesis by sphingosylphosphorylcholine (SPC). In the present study, we confirmed that SPC activated ERK and that a specific inhibitor of the ERK pathway (PD98059) recovered SPC-induced hypopigmentation. Moreover, we found that SPC significantly reduces protein phosphatase 2A (PP2A) activity in Mel-Ab cells, and that PP2A activator treatment abrogated SPC-induced hypopigmentation. We determined that α-melanocyte-stimulating hormone (α-MSH) increased the expression of dual-specificity phosphatase 6 (DUSP6), an ERK phosphatase, in a time-dependent manner. In contrast, SPC decreased the level of DUSP6 in Mel-Ab cells. Furthermore, inhibiting DUSP6 increased ERK activation and subsequently augmented the SPC-induced hypopigmenting effects. Taken together, our data suggest that SPC-induced phosphatase inhibition is also responsible for the hypopigmentary effects.


Assuntos
Fosfatase 6 de Especificidade Dupla/metabolismo , Hipopigmentação/enzimologia , Proteína Fosfatase 2/metabolismo , Animais , Linhagem Celular , Ativação Enzimática , Ativadores de Enzimas/farmacologia , MAP Quinases Reguladas por Sinal Extracelular/antagonistas & inibidores , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Flavonoides/farmacologia , Hipopigmentação/induzido quimicamente , Sistema de Sinalização das MAP Quinases , Melaninas/biossíntese , Camundongos , Fosforilação , Fosforilcolina/análogos & derivados , Processamento de Proteína Pós-Traducional , Esfingosina/análogos & derivados
18.
Biochim Biophys Acta ; 1821(6): 914-22, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22405860

RESUMO

Leucine-rich glioma inactivated 3 (LGI3) is a secreted protein and a member of LGI/epitempin family. We previously showed that LGI3 was highly expressed in brain and played regulatory roles in neuronal exocytosis and differentiation. Besides the nervous system, LGI3 was shown to be expressed in diverse tissues. In this study, we found that LGI3 and its receptor candidate ADAM23 were expressed in adipose tissues and 3T3-L1 cells. 3T3-L1 preadipocytes secreted a 60-kDa protein, a major secreted form of LGI3, which declined with adipocyte differentiation. LGI3 was also expressed in adipose tissue macrophages in the ob/ob mice and in macrophage cell line. The 60-kDa LGI3 protein was selectively increased in the ob/ob adipose tissues comparing with the lean mice. Pull-down experiments, coimmunoprecipitation and immunocytochemistry indicated that LGI3 associated with ADAM23 in adipose tissues and 3T3-L1 cells. Knockdown of LGI3 or ADAM23 by siRNA increased adipogenesis in 3T3-L1 cells. Treatment with LGI3 protein did not affect preadipocyte proliferation but attenuated adipogenesis and this effect was reversed by siRNA-mediated knockdown of ADAM23. Taken together, we propose that LGI3 may be a candidate adipokine that is perturbed in obesity and suppresses adipogenesis through its receptor, ADAM23.


Assuntos
Proteínas ADAM/metabolismo , Adipogenia/fisiologia , Tecido Adiposo/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Células 3T3-L1 , Proteínas ADAM/genética , Adipogenia/efeitos dos fármacos , Adipogenia/genética , Tecido Adiposo/citologia , Animais , Western Blotting , Linhagem Celular , Proliferação de Células/efeitos dos fármacos , Relação Dose-Resposta a Droga , Expressão Gênica , Imuno-Histoquímica , Macrófagos/citologia , Macrófagos/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Obesos , Proteínas do Tecido Nervoso/genética , Proteínas do Tecido Nervoso/farmacologia , Obesidade/genética , Obesidade/metabolismo , Obesidade/fisiopatologia , Ligação Proteica , Interferência de RNA , Reação em Cadeia da Polimerase Via Transcriptase Reversa
19.
J Biomed Sci ; 18: 55, 2011 Aug 13.
Artigo em Inglês | MEDLINE | ID: mdl-21838918

RESUMO

BACKGROUND: Sphingosylphosphorylcholine (SPC) acts as a potent lipid mediator and signaling molecule in various cell types. In the present study, we investigated the effects of SPC on melanogenesis and SPC-modulated signaling pathways related to melanin synthesis. METHODS: Melanin production was measured in Mel-Ab cells. A luciferase assay was used to detect transcriptional activity of the MITF promoter. Western blot analysis was performed to examine SPC-induced signaling pathways. RESULTS: SPC produced significant hypopigmentation effects in a dose-dependent manner. It was found that SPC induced not only activation of Akt but also stimulation of mTOR, a downstream mediator of the Akt signaling pathway. Moreover, SPC decreased the levels of LC3 II, which is known to be regulated by mTOR. Treatment with the mTOR inhibitor rapamycin eliminated decreases in melanin and LC3 II levels by SPC. Furthermore, we found that the Akt inhibitor LY294002 restored SPC-mediated downregulation of LC3 II and inhibited the activation of mTOR by SPC. CONCLUSIONS: Our data suggest that the mTOR signaling pathway is involved in SPC-modulated melanin synthesis.


Assuntos
Hipopigmentação/metabolismo , Melaninas/biossíntese , Fosforilcolina/análogos & derivados , Transdução de Sinais/fisiologia , Esfingosina/análogos & derivados , Serina-Treonina Quinases TOR/metabolismo , Análise de Variância , Animais , Western Blotting , Linhagem Celular , Cromonas/farmacologia , Relação Dose-Resposta a Droga , Hipopigmentação/induzido quimicamente , Luciferases , Camundongos , Microscopia de Contraste de Fase , Monofenol Mono-Oxigenase/metabolismo , Morfolinas/farmacologia , Fosforilcolina/farmacologia , Fosforilcolina/toxicidade , Proteínas Proto-Oncogênicas c-akt/antagonistas & inibidores , Proteínas Proto-Oncogênicas c-akt/metabolismo , Sirolimo/farmacologia , Esfingosina/farmacologia , Esfingosina/toxicidade , Transfecção
20.
Biochim Biophys Acta ; 1813(1): 80-90, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-20888374

RESUMO

Nonsteroidal anti-inflammatory drugs (NSAIDs) have been considered for use in the prevention and treatment of cancer malignancy. FR122047 (FR) is known to have an anti-inflammatory effect, but the anticancer activity of the chemical has not yet been identified. In the present study, we could find that treatment of breast cancer MCF-7 cells with FR led to apoptosis accompanying with apparent activation of caspases. Treatment of caspase-specific inhibitors revealed that FR-induced apoptosis was caspase-8-dependent and inhibition of caspase-9 activity resulted in unexpected, marked enhancement of cell death. Knockdown of caspase-9 expression by specific siRNA caused increased susceptibility to FR-induced cell death, consistent with the results obtained with treatment of caspase-9 inhibitor. Inhibition of caspase-9 blocked the autophagic process by modulating lysosomal pH and acid-dependent cathepsin activities and augmented cell death due to blockage of cytoprotective autophagy. MCF-7 cells treated with sulforaphane, an autophagy-inducing drug, also showed marked accumulation of LC3-II, and co-treatment with caspase-9 inhibitor brought about increased susceptibility to sulforaphane-induced cell death. Different from the cases with FR or sulforaphane, etoposide- or doxorubicin-induced cell death was suppressed with co-treatment of caspase-9 inhibitor, and the drugs failed to induce significant autophagy in MCF-7 cells. Taken together, our data originally suggest that inhibition of caspase-9 may block the autophagic flux and enhance cell death due to blockage of cytoprotective autophagy.


Assuntos
Autofagia , Neoplasias da Mama/patologia , Caspase 9/metabolismo , Transdução de Sinais , Antibióticos Antineoplásicos/farmacologia , Anticarcinógenos/farmacologia , Antineoplásicos Fitogênicos/farmacologia , Apoptose/efeitos dos fármacos , Western Blotting , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/metabolismo , Caspase 9/genética , Inibidores de Caspase , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Citoplasma/metabolismo , Doxorrubicina/farmacologia , Ativação Enzimática/efeitos dos fármacos , Etoposídeo/farmacologia , Feminino , Citometria de Fluxo , Humanos , Isotiocianatos , Mitocôndrias/metabolismo , RNA Mensageiro/genética , RNA Interferente Pequeno/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Sulfóxidos , Tiocianatos/farmacologia , Células Tumorais Cultivadas
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