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INTRODUCTION: Although it has been reported that the antidiabetic drug metformin has multiple extra-hypoglycemic activities, such as anti-oxidation, antiaging, and even antitumor, topical metformin also can induce hair regeneration, but the precise mechanism involved in that process is still unclear. OBJECTIVES: The aim of this study was to assess the effect of metformin on hair growth in a mouse hair-follicle reconstitution model generated by in vitro self-assembled three-dimensional aggregates of epidermal and dermal cells (DCs) (3D aggregates). METHODS: Epidermal cells and DCs were isolated and cultured from the mouse skin of 50 C57BL/6 mouse pups (1-day-old). For tracing the distribution of DCs during the self-assembly process of 3D aggregates, the DCs were labeled with Vybrant Dil Cell-Labeling Solution and mixed with epidermal cells at a 1:1 ratio. Formed 3D aggregates were treated with 10 mM metformin and then were grafted into recipient BALB/c nude mice. The biomarkers (hepatocyte growth factor [HGF], prominin-1 [CD133], alkaline phosphatase [ALP], ß-catenin, and SRY-box transcription factor 2 [SOX2]) associated with the hair-inductive activity of DCs were detected in the grafted skin tissues and in cultured 3D aggregates treated with metformin using immunofluorescent staining, quantitative real-time RT-PCR (qRT-PCR), and Western blotting. Furthermore, the expression levels of CD133 were also examined in DCs with different passage numbers using qRT-PCR and Western blotting. RESULTS: Metformin directly stimulates the activity of ALP of cultured 3D aggregates, upregulates both the protein and mRNA expression levels of molecular markers (HGF, CD133, ALP, ß-catenin, and SOX2), and improves the survival rate of reconstituted hair follicles. Moreover, we also found that metformin increases the expression of CD133 in DCs thus maintaining their trichogenic capacity that would normally be lost by serial subculture. CONCLUSIONS: These results suggest that metformin can promote hair follicle regeneration in vitro through upregulation of the hair-inductive capability of DCs, warranting further evaluation in the clinical treatment of male or female pattern hair loss.
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Metformina , beta Catenina , Animales , Células Cultivadas , Femenino , Cabello , Folículo Piloso , Masculino , Metformina/farmacología , Ratones , Ratones Endogámicos C57BL , Ratones Desnudos , beta Catenina/genéticaRESUMEN
Four highly oxygenated sesquiterpenoids, illimicranolides A (1) and B (2), and illicinolides E (3) and F (4), were obtained from the fruits of Illicium micranthum Dunn, as well as one known analog, illicinolide B (5). The chemical structures of 1-4 were determined comprehensively by 1D (1 H and 13 C) and 2D (HMBC, HSQC, 1 H-1 H COSY, and ROESY) NMR, and HR-ESI-MS data. Structurally, compound 1 was an unprecedented sesquiterpenoid with a 5/5/6/5-fused tetracyclic ring system and was the first seco-prezizaane sesquiterpenoid featuring a 11,8-γ-lactone ring. Compounds 3 and 4 were the fifth and sixth examples of illicinolide-type sesquiterpenoids. Moreover, compound 1 demonstrated neurotrophic activity of NGF-induced PC12 cells with differentiation rate of 10.34 % at a concentration of 10⠵M.
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Illicium , Sesquiterpenos , Animales , Frutas , Illicium/química , Lactonas/química , Estructura Molecular , Ratas , Sesquiterpenos/química , Sesquiterpenos/farmacologíaRESUMEN
Seven new labdane diterpenoids, hypopurolides A-G (1-7) were discovered from the aerial part of Hypoestes purpurea, along with one known analog, hypopurin D (8). The structures of 1-7 were characterized based on 1 H-, 13 C-, and 2D-NMR, and HR-ESI-MS spectra. The absolute configurations of 1-7 were defined by single-crystal X-ray diffraction and electronic circular dichroism (ECD) data. Compounds 1-8 were tested for their nitric oxide (NO) inhibitory and cytotoxic effects. Compound 6 displayed moderate inhibitory effect toward LPS-induced NO release in RAW 264.7 cells with an IC50 value of 41.50â µM.
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Acanthaceae , Diterpenos , Acanthaceae/química , Animales , Diterpenos/química , Diterpenos/farmacología , Ratones , Estructura Molecular , Óxido Nítrico , Células RAW 264.7RESUMEN
Two unprecedented tetranorlanostane triterpenoids, poricolides A (1) and B (2), and two new lanostane triterpenoids, 3ß-acetoxy-24-methyllanosta-8,16,24(31)-trien-21-oic acid (3) and 3ß-acetoxylanosta-7,9(11),16,23-tetraen-21-oic acid (4), were isolated from the epidermis of Poria cocos. The structures of 1-4 were determined via analysis of 1 H-, 13 C-, and 2D-NMR, and HR-ESI-MS data, and the absolute configurations of 1 and 3 were established by single-crystal X-ray diffraction analysis. Compounds 1 and 2 were the first report of tetranorlanostane triterpenoid having a δ-lactone ring at C(17). Compounds 3 and 4 were rare lanostane triterpenoids having a double bond between C(16) and C(17). Compounds 1-4 exhibited potent antiproliferative effects against A549, SMMC-7721, MCF-7, and SW480 cancer cell lines with IC50 values from 16.19±0.38 to 27.74±1.12â µM.
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Antineoplásicos/farmacología , Epidermis/química , Triterpenos/farmacología , Wolfiporia/química , Antineoplásicos/química , Antineoplásicos/aislamiento & purificación , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Cristalografía por Rayos X , Relación Dosis-Respuesta a Droga , Ensayos de Selección de Medicamentos Antitumorales , Humanos , Modelos Moleculares , Conformación Molecular , Estereoisomerismo , Triterpenos/química , Triterpenos/aislamiento & purificaciónRESUMEN
There is growing evidence that dermal papilla cells(DPCs)act as the organizing center to induce the cyclic hair regeneration.On one hand,DPCs secrete cytokines or growth factors to regulate the differentiation,proliferation,and migration of epithelial stem cells(EpSCs)and melanocyte stem cells(MeSCs)residing in the bulge region.On the other hand,DPCs manipulate the microenvironment(also termed as niche)for both EpSCs and MeSCs,such as the size of dermal papilla,the distance between dermal papilla and the bulge region,and the lymphatic drainage and sympathetic nerve innervation surrounding the bulge region,thereby orchestrating the cycling hair growth.Recent studies have demonstrated at least four subpopulations existing in dermal papillae,which induce the unilineage transit-amplifying epithelial cells to form the concentric multilayers of hair shafts and sheaths.In addition,emerging study has indicated that sustained psychological stress potentially leads to hyperactivation of the sympathetic nerves that innervate the bulge region.The large amount of norepinephrine released by the nerve endings forces MeSCs to rapidly and abnormally proliferate,resultantly causing the depletion of MeSC pool and the loss of hair pigment.Understanding the molecular regulation of hair growth and pigmentation by DPCs holds substantial promise for the future use of cultured DPCs in vitro to treat hair loss.
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Dermis , Folículo Piloso , Diferenciación Celular , Células Cultivadas , PigmentaciónRESUMEN
Temozolomide (TMZ) has received much attention, notably in the treatment of malignant glioma and malignant melanoma. The objective of this study was to compare the clinical efficacy and safety of TMZ alone and TMZ-based combination drug therapy in patients with melanoma. Using "temozolomide" as a keyword combined with "melanoma" and "randomized controlled trials" as Medical Subject Headings, the following electronic databases were searched: the Cochrane library, MEDLINE, EBSCO, EMBASE, Ovid, cNKI, and cBMDisc. The evaluating indicators were overall response rate (ORR), 1-year survival rate, and several of the most frequent adverse events. Five randomized controlled trials met our criteria and were included in the meta-analysis, with a total of 703 participants (309 patients received TMZ alone, and 394 patients received combined regimens). The meta-analysis showed that the ORR for TMZ-based drug therapy was higher than TMZ alone [relative risk (RR) = 1.44; 95% confidence interval (CI), 1.06-1.95], but the 1-year survival rate was not significantly different between the two groups (RR = 1.13; 95% CI, 0.92-1.40). These results suggested that the impact of these increased response rates was not translated into a survival benefit. Moreover, we found no difference in the incidence of adverse events analyzed. The currently available evidence showed that the TMZ-combination therapy may moderately improve the response rate, but there was no corresponding increased toxicity. Future large-scale, high-quality, placebo-controlled, double-blind trials are needed.
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Antineoplásicos Alquilantes/uso terapéutico , Dacarbazina/análogos & derivados , Melanoma/tratamiento farmacológico , Antineoplásicos Alquilantes/administración & dosificación , Antineoplásicos Alquilantes/efectos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/efectos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Dacarbazina/administración & dosificación , Dacarbazina/efectos adversos , Dacarbazina/uso terapéutico , Humanos , Ensayos Clínicos Controlados Aleatorios como Asunto , Temozolomida , Resultado del TratamientoRESUMEN
BACKGROUND: To investigate the in vitro multi-lineage differentiation of adipose-derived adult stem cells and their ability to differentiate into endothelial cells. METHODS: Adipose-derived adult stem cells were isolated for detection of the immune phenotype, cell doubling time, cycle, and induction of endothelial cell differentiation in vitro. The expression of endothelial cell-specific surface markers was measured immunocytochemically. RESULTS: Adipose-derived adult stem cells have multi-lineage differentiation potential and can differentiate into endothelial cells in vitro. CONCLUSIONS: Adipose-derived adult stem cells have the same differentiation ability with those derived from the bone marrow, as both can differentiate into endothelial cells. These findings have opened up the prospect of adipose-derived adult stem cells in angiogenesis therapy.
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Tejido Adiposo/citología , Células Madre Adultas/fisiología , Diferenciación Celular , Linaje de la Célula , Células Endoteliales/fisiología , Células Madre Mesenquimatosas/fisiología , Células Madre Multipotentes/fisiología , Neovascularización Fisiológica , Adulto , Células Madre Adultas/metabolismo , Biomarcadores/metabolismo , Células Cultivadas , Células Endoteliales/metabolismo , Femenino , Humanos , Células Madre Mesenquimatosas/metabolismo , Células Madre Multipotentes/metabolismo , Fenotipo , Factores de TiempoRESUMEN
BACKGROUND: Although reports suggest that tranexamic acid (TXA) has clinical benefits for melasma patients by oral, intralesional and topical treatment, the optimal route of TXA therapy and the underlying mechanism involved remain poorly defined. OBJECTIVE: To compare the skin lightening effect between oral TXA and topical TXA and to dissect the molecular mechanisms using ultraviolet B (UVB)-induced hyperpigmentation mouse model, ex vivo cultured human skin explant, and cultured melanocytes (MCs) and endothelial cells. METHODS: Melanin content and cluster of differentiation 31 (CD31)-positive cell numbers were measured in tail skins from UVB-irradiated mice treated by intragastral or topical TXA using immunofluorescent and Fontana-Masson staining. The conditioned medium (CM) was harvested from human umbilical vein endothelial cells treated with or without 3 mM TXA and was used to treat MCs for 48 hours. mRNA and protein levels of tyrosinase and microphthalmia-associated transcription factor were measured using quantitative real-time reverse transcription polymerase chain reaction and western blotting assays. HMB45- and CD31-positive cell numbers as well as melanin content were also examined in ex vivo cultured human skin explants. RESULTS: The hyperpigmented phenotype were significantly mitigated in UVB-irradiated tail skin plus intragastral TXA-treated mice compared with mice treated with UVB only or with UVB plus topical TXA. CD31-positive cell numbers correlated with the anti-melanogenic activity of TXA therapy. The data from cultured cells and skin tissues showed that suppression of endothelin-1 (ET-1) in vascular endothelial cells by TXA reduced melanogenesis and MC proliferation. CONCLUSION: Oral TXA outperforms topical TXA treatment in skin lightening, which contributes to suppression of ET-1 in dermal microvascular endothelial cells by TXA.
RESUMEN
Activation of the α-melanocyte-stimulating hormone (αMSH)/melanocortin-1 receptor (MC1R) signalling pathway exerts antagonistic actions on cutaneous inflammatory and fibrogenic responses in addition to promoting pigment production. Herein, the expression of MC1R by keloid-derived fibroblasts and keloid scar tissue was investigated using a range of techniques. MC1R mRNA expression levels in five different keloid fibroblast cell lines were significantly reduced to less than half compared with five normal fibroblast cell lines (P < 0.05). Immunohistological analysis of tissue samples indicated that MCR1 immunoreactivity in both epidermal and dermal compartments of five keloid tissue samples was dramatically decreased compared with normal skin (P < 0.05). Insufficient expression of MC1R on human dermal fibroblasts might abolish the αMSH-mediated suppression of collagen production and myofibroblast transformation elicited by the profibrotic cytokine-transforming growth factor-ß1. Restoration of reduced MC1R by dermal fibroblasts may lead to novel scar-reducing therapeutic approaches for treating this refractory fibrotic disease.
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Colágeno/biosíntesis , Fibroblastos/metabolismo , Queloide/metabolismo , Receptor de Melanocortina Tipo 1/metabolismo , Piel/metabolismo , Regulación de la Expresión Génica , Humanos , Melanocitos/citología , Transducción de Señal , Factor de Crecimiento Transformador beta1/metabolismo , Cicatrización de Heridas , alfa-MSH/metabolismoRESUMEN
Vitiligo is a chronic autoimmune disease characterized by the T helper 1 (Th1) cytokine-driven immune destruction of melanocytes (MCs). Although narrowband ultraviolet B (NBUVB) phototherapy has been proven to be an effective therapeutic option, the repigmentation response to that phototherapy varies greatly in different vitiligo patients. Here, we demonstrate that there is an increase of NBUVB-induced cellular senescence in vitiligo MCs exposed to Th1 cytokine interferon γ (IFNγ) and/or tumor necrosis factor α (TNFα) in lesional vitiligo skin from poor responders who had undergone NBUVB phototherapy. Supplementation with exogenous recombinant human stem cell factor (rhSCF) in the culture medium as well as the lentiviral vector-mediated overexpression of cKIT could prevent the MCs from the IFNγ/TNFα-accelerated cellular senescence. Mechanistic studies indicated that the reduced ratio of membrane-bound KIT (mKIT) to the soluble form of KIT (sKIT) is directly related to the cellular senescence of vitiligo MCs following exposure to IFNγ and TNFα. Furthermore, the matrix metalloprotease 9 (MMP9) inhibitor GM6001 attenuates the production of sKIT via the suppression of cKIT ectodomain shedding. Altogether, our study indicates that the presence of Th1 cytokines IFNγ and/or TNFα in the epidermal milieu might impair the repigmentation response of vitiligo patients to NBUVB phototherapy.
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Vitíligo , Humanos , Vitíligo/radioterapia , Vitíligo/tratamiento farmacológico , Factor de Necrosis Tumoral alfa , Citocinas , Interferón gamma , Fototerapia , Melanocitos/patología , Resultado del Tratamiento , AceleraciónRESUMEN
Repigmentation of the skin in patients with vitiligo represents an intricate process in which the depigmented epidermis is replenished by functional melanocytes (MCs) that migrate from undamaged hair follicles and/or surrounding areas. We characterized whether MCs release a secreted form of Pmel17 (sPmel17) protein after exposure to UVB, thereby weakening the cell-cell adhesions of keratinocytes (KCs), which provides MCs the opportunity to migrate to areas devoid of MCs. At first, we examined the interactions of sPmel17 and FHL2 (four-and-a-half LIM domain protein 2) in KCs treated with the conditioned media (CM) from MCs exposed to UVB. The results showed that both the protein and mRNA levels of FHL2 were significantly upregulated in KCs treated with sPmel17-enriched CM from UVB-exposed MCs. We also found that there are physical interactions between sPmel17 and FHL2 as analyzed by reciprocal coimmunoprecipitation assays and double immunofluorescence staining. The CM from UVB-exposed MCs signaled KCs to remodel the actin cytoskeleton and reduce E-cadherin expression. However, the CM from UVB-exposed and Pmel17-silenced or from UVB-unexposed MCs failed to do this. To further determine the in situ distributions of sPmel17, FHL2, and E-cadherin, we examined the expression profiles of those proteins in the skin from healthy subjects and from depigmented or repigmented vitiligo using immunofluorescence and immunohistochemical staining. The results showed that the expression of sPmel17 was positively correlated with FHL2 but not to E-cadherin. The colocalization of FHL2 and sPmel17 was also observed in UVB-exposed mouse tail skin. Together, the upregulation of FHL2 in KCs requires stimulation by sPmel17 secreted from MCs and activation of the sPmel17-FHL2-E-cadherin axis offers a potential therapeutic target to expedite the repigmentation process in patients with vitiligo.
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Queratinocitos/ultraestructura , Melanocitos/efectos de la radiación , Rayos Ultravioleta/efectos adversos , Animales , Femenino , Humanos , Masculino , Ratones , Ratones Transgénicos , TransfecciónRESUMEN
BACKGROUND: Few studies have addressed the impact of the psoriasis-related proinflammatory cytokines on the proliferation and melanogenesis of melanocytes (MCs) in lesional psoriatic skin. OBJECTIVE: We investigated the effects of TNFα, IL17A, and IL8 on the proliferation and melanin synthesis of MCs. METHODS: Skin specimens were biopsied from patients with psoriasis vulgaris at the active stage, or from the tail skin of Dct-LacZ mice with imiquimod (IMQ)-induced psoriasiform dermatitis. Cultured keratinocytes (KCs), MCs, and human skin explants were used in this study. The numbers of MCs were measured via ß-galactosidase staining, EdU incorporation and HMB45 immunohistochemical staining. The expression of human ß-defensin 3 (hBD3) in KCs was silenced by siRNA, the conditioned medium (CM) from siRNA-transfected KCs was used to treat MCs, then followed by αMSH stimulation. The melanogenesis-related genes were examined by using qRT-PCR and western blotting. RESULTS: The increased number of MCs and decreased melanin content were highly relevant to the enhanced expression of IL8 and BD3 both in human psoriatic skin and in IMQ-treated mouse tail skin. IL8 expression in KCs and CXCR2 expression in MCs was significantly increased by IL17A and TNFα, the αMSH-induced upregulations of microphthalmia-associated transcription factor (MITF) and tyrosinase in MCs were abrogated by the CM from hBD3-unsilenced KCs, but not from hBD3-silenced KCs. CONCLUSION: Our results suggest the roles of IL8-CXCR2 activation in promoting MC proliferation and of BD3 upregulation in reducing melanogenesis. These findings have been implicated in the underlying mechanism that active psoriasis prefers hypopigmentation despite chronic inflammation.
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Psoriasis , Factor de Necrosis Tumoral alfa , Humanos , Animales , Ratones , Factor de Necrosis Tumoral alfa/metabolismo , Melaninas/metabolismo , Citocinas/metabolismo , Interleucina-8/metabolismo , Melanocitos/metabolismo , Psoriasis/metabolismo , ARN Interferente Pequeño/metabolismo , Imiquimod/farmacología , Proliferación Celular , Factor de Transcripción Asociado a Microftalmía/metabolismoRESUMEN
Several variants of CTLA-4 have been reported to be associated with susceptibility systemic lupus erythematosus (SLE); however, findings have been inconsistent across different populations. Using a case-control study design, we have investigated the role of CTLA-4 polymorphism at positions -1661 and -1722 on SLE susceptibility in our Chinese SLE population in central China's Hubei province. Samples were collected from 148 SLE patients and 170 healthy controls. Polymerase chain reaction restriction fragments length polymorphism (PCR-RFLP) was used to analyze the genotypes of the two sites. Statistically significant difference was observed in genotypes for -1722, but not for -1661. The frequency of the T allele on the -1722 SNP was significantly increased in SLE patients: 57.8% versus 40.6% in controls (P < 0.001, OR = 2.002). While the detected C allele frequency in the controls was significantly elevated in comparison to that in the SLE patients (59.4% versus 42.2%). On the contrary, no association was found between SLE and CTLA-4 polymorphism at position -1661.
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Antígeno CTLA-4/genética , Lupus Eritematoso Sistémico/genética , Estudios de Casos y Controles , China/epidemiología , Femenino , Predisposición Genética a la Enfermedad , Humanos , Lupus Eritematoso Sistémico/epidemiología , Masculino , Oportunidad Relativa , Reacción en Cadena de la Polimerasa , Polimorfismo de Longitud del Fragmento de Restricción , Polimorfismo de Nucleótido Simple , Regiones Promotoras GenéticasRESUMEN
Keloid is a type of unusually raised scar. Botulinum toxin A (BTX-A) has a great application potential in keloids treatment. Here, we investigated the functional role of BTX-A in keloids. We separated keloid tissues and normal skin tissues from keloid patients and found that the expression of myofibroblast markers, α-SMA, Collagen I, and Collagen III was increased in the keloid tissues as compared with normal skin tissues. Keloid fibroblasts derived from keloid tissues were treated with TGF-ß1 to induce the differentiation of fibroblasts into myofibroblasts. The keloid myofibroblasts displayed a significant up-regulation of α-SMA. BTX-A enhanced the expression of adipocyte markers, PPARγ and C/EBPα, and increased the accumulation of lipid droplets, and reduced the expression of α-SMA, Collagen I, and Collagen III in the keloid myofibroblasts. Moreover, BTX-A enhanced the expression of BMP4 and p-smad1/5/8. Noggin (BMP4 antagonist) treatment reversed BTX-A-mediated increase of PPARγ and C/EBPα expression and lipid droplets, and down-regulation of α-SMA, Collagen I, and Collagen III in primary keloid myofibroblasts. In conclusion, BTX-A promoted the transdifferentiation of primary keloid myofibroblasts into adipocyte-like cells, which may attribute to activate BMP4/Smad signalling pathway. Thus, this study provides new insights into the mechanism of BTX-A in keloid.
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Toxinas Botulínicas Tipo A/farmacología , Queloide/tratamiento farmacológico , Miofibroblastos/efectos de los fármacos , Fármacos Neuromusculares/farmacología , Adipocitos/citología , Adipocitos/efectos de los fármacos , Proteína Morfogenética Ósea 4/metabolismo , Transdiferenciación Celular/efectos de los fármacos , Células Cultivadas , Colágeno Tipo I/metabolismo , Colágeno Tipo III/metabolismo , Fibroblastos/citología , Humanos , Queloide/patología , Miofibroblastos/citología , Transducción de Señal/efectos de los fármacos , Proteínas Smad/metabolismoRESUMEN
BACKGROUND: There is growing evidence that 5-fluorouracil (5-FU) combined with therapeutic trauma can effectively induce skin repigmentation in vitiligo patients who are unresponsive to conventional treatments. Previous studies have mainly focused on identifying the antimitotic activity of 5-FU for the treatment of skin cancer, but few studies have investigated its extra-genotoxic actions favoring melanocyte recruitment. METHODS: We utilized the full thickness excisional skin wound model in Dct-LacZ transgenic mice to dynamically assess the migration of melanocytes in the margins of wounds treated with or without 5-FU. The in-situ expression of CXCL12 was examined in the wound beds using immunofluorescence staining. Quantitative real-time polymerase chain reaction and Western blotting analyses were performed to detect the expression levels of CXCL12 mRNA and protein in primary mouse dermal fibroblasts treated with or without 5-FU. Transwell assays and fluorescein isothiocyanate (FITC)-phalloidin staining were used to observe cell migration and filamentous actin (F-actin) changes of melan-a murine melanocytes. RESULTS: Whole mount and cryosection X-gal staining showed that the cell numbers of LacZ-positive melanocytes were much higher in the margins of dorsal and tail skin wounds treated with 5-FU compared with the controls. Meanwhile, CXCL12 immunostaining was significantly increased in the dermal compartment of wounds treated with 5-FU (control vs. 5-FU, 22.47â±â8.85 vs. 44.69â±â5.97, Pâ<â0.05). Moreover, 5-FU significantly upregulated the expression levels of CXCL12 mRNA (control vs. 5-FU, 1.00â±â0.08 vs. 1.54â±â0.06, Pâ<â0.05) and protein (control vs. 5-FU, 1.00â±â0.06 vs. 2.93â±â0.10, Pâ<â0.05) in cultured fibroblasts. Inhibition of the CXCL12/CXCR4 axis suppressed melanocyte migration in vitro using a CXCL12 small interfering RNA (siRNA) or a CXCR4 antagonist (AMD3100). CONCLUSION: 5-FU possesses a pro-pigmentary activity through activation of the CXCL12/CXCR4 axis to drive the chemotactic migration of melanocytes.
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Quimiocina CXCL12 , Fluorouracilo , Animales , Movimiento Celular , Proliferación Celular , Quimiocina CXCL12/genética , Fibroblastos , Fluorouracilo/farmacología , Fluorouracilo/uso terapéutico , Humanos , Ratones , ARN Mensajero , Receptores CXCR4RESUMEN
Human skin is a highly efficient self-renewing barrier that is critical to withstanding environmental insults. Undifferentiated keratinocyte stem cells reside in the basal layer of the epidermis and in hair follicles that continuously give rise to progenies ensuring epidermal turnover and renewal. Ultraviolet (UV) radiation is a proven cause of skin keratinocyte cancers, which preferentially occur at sun-exposed areas of the skin. Fortunately, melanocytes produce melanin that is packaged in specific organelles (termed melanosomes) that are then delivered to nearby keratinocytes, endowing the recipient cells with photoprotection. It has long been thought that melanosome transfer takes place stochastically from melanocytes to keratinocytes via an as-yet-unrecognized manner. However, recent studies have indicated that melanosomes are distributed regionally in the basal layer of the skin, affording localized intensive photoprotection for progenitor keratinocytes and stem cells that reside in the microenvironment of the basal epidermis. In this review, we summarize current knowledge about molecular and cellular mechanisms that are responsible for the selective transfer and exclusive degradation of melanosomes in the epidermis, emphasizing implications for skin carcinogenesis.
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Epidermis/efectos de la radiación , Melanosomas/metabolismo , Células Madre/citología , Rayos Ultravioleta/efectos adversos , Carcinogénesis/efectos de la radiación , Células Cultivadas , Humanos , Queratinocitos/citología , Queratinocitos/metabolismo , Queratinocitos/efectos de la radiación , Envejecimiento de la Piel/efectos de la radiación , Células Madre/metabolismo , Células Madre/efectos de la radiaciónRESUMEN
Current treatment of vitiligo is still a great challenge, since most cases of vitiligo have variable re-pigmentation outcomes due to their unpredictable responses to existing therapeutic regimens. There is an urgent need to identify this re-pigmentation process and to develop novel therapies. This review illustrates the most current research and latest understanding of vitiligo skin re-pigmentation and related regulatory mechanisms. Literature was collected from PubMed until January 2020, using the search terms including "vitiligo," "re-pigmentation," "phototherapy," "narrow-band ultraviolet B, " "excimer," "fractional carbon dioxide laser," and "melanocyte stem cells." Literature was mainly derived from English articles. Article type was not limited. Emerging evidence suggests that patients with vitiligo present various re-pigmentation patterns following ultraviolet B phototherapy, which relies on different cell reservoirs from the perilesional margins and/or from uninvolved hair follicles to replenish functional melanocytes that are lost in vitiliginous skin. The following events are likely to be involved in this re-pigmentation process, including: 1) changes in the paracrine secretion and distribution of transforming growth factor-ß1 in the bulge area and in the epidermis; 2) the enhanced transfer of dermal pro-melanogenic growth factors to the epidermis; and 3) the induction of a C-X-C motif chemokine ligand (CXCL) 12-enriched micro-environment that efficiently recruits CXCR4- or CXCR7-positive melanocytes. Ongoing studies on the cellular and molecular events underlying vitiligo re-pigmentation will help design new therapeutic strategies to improve treatment outcomes.
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Vitíligo , Epidermis , Folículo Piloso , Humanos , Melanocitos , Pigmentación de la PielRESUMEN
Clinical studies have proven that ultraviolet B (UVB) based phototherapy can induce perifollicular and marginal repigmentation patterns in the skin of vitiligo patients. It is, however, difficult to conceive how melanocytes can easily exit from their tightly interconnected epidermal microenvironment to reenter a different location in the skin to establish a new network with neighboring keratinocytes. While it is known that matrix metalloprotease 9 (MMP9) is involved in the degradation of the extracellular matrix in physiological or pathological processes, little is known about whether MMP9 affects melanocyte migration in vitiligo repigmentation. To investigate the effects of the p53 transient receptor potential cation channel subfamily M member 1 (TRPM1)/microRNA (miR/miRNA)211MMP9 axis to regulate melanocyte migration following exposure to UVB, the expression profile of MMP9 in cultured human melanocytes transfected with or without the miR211mimic and p53GFP lentiviral vector, respectively were determined. Quantitative polymerase chain reaction and western blotting were used to examine p53, TRPM1 and MMP9 mRNA and protein levels in UVBexposed and unexposed cells. The capacity of melanocytes to migrate on collagen IV substrate was estimated using a Transwell migration assay. Interestingly, the upregulation of p53 and MMP9 at the mRNA and protein levels was evident in melanocytes treated with single or repeat exposures to UVB, whereas levels of TRPM1 and miR211 were significantly suppressed in UVBexposed melanocytes compared with the UVBunexposed control cells. These results indicate that the p53TRPM1/miR211MMP9 axis is significantly activated in melanocytes exposed to UVB. Notably, the ability of melanocyte migration was altered by the overexpression of p53 using a lentiviral vector and by the upregulation of miR211 using an miRNA mimic. That altered migration could be neutralized by cotreatment with GM6001 (a broadspectrum MMP inhibitor). Overall, these results show that the MMP9mediated migration of melanocytes is regulated by a novel mechanism driven by the p53TRPM1/miR211MMP9 axis. Activation of the p53TRPM1/miR211MMP9 axis potentially represents an attractive therapeutic target to improve repigmentation outcomes in vitiligo patients.
Asunto(s)
Metaloproteinasa 9 de la Matriz/metabolismo , Melanocitos/metabolismo , Melanocitos/efectos de la radiación , MicroARNs/metabolismo , Canales Catiónicos TRPM/metabolismo , Proteína p53 Supresora de Tumor/metabolismo , Rayos Ultravioleta , Adolescente , Adulto , Western Blotting , Movimiento Celular/efectos de la radiación , Células Cultivadas , Humanos , Adulto JovenRESUMEN
OBJECTIVE: To investigate whether the mutation in dopachrome tautomerase (Dct) affects melanosome maturation and anti-oxidative potential in cultured melanocytes (MCs). METHODS: Slaty and melan-a MCs were derived from the skins of neonatal Dct(Slt) and C57 BL/6J mice respectively. Their detailed melanosome structures were examined with a transmission electron microscopy (TEM) and their eumelanin granules characterized by Fontana-Masson staining. Furthermore, the tyrosinase activity and three melanogenic proteins, i. e., tyrosinase, tyrosinase-related protein 1 and Dct, were also measured with a spectrophotometry method or Western blot assay. The level of intracellular reactive oxygen species (ROS) was monitored by 2,7-dichlorofluorescin diacetate (DCF-DA) labeling. RESULTS: Mature stage IV melanosomes markedly decreased in slaty MCs under TEM. The brownish granules stained with Fontana-Masson silver method were far less in slaty MCs than in melan-a MCs. The cell pellet of slaty MCs was white in color, but the similarities between slaty and melan-a were found in tyrosinase activity and its protein expression. The relative intensity of DCF fluorescence was 8.9 +/- 0.7 for slaty melanocytes versus 8.9 +/- 2.5 for melan-a melanocytes prior to UVA irradiation, but an abrupt ROS production was merely observed in slaty MCs (18.0 +/- 0.3) other than in melan-a MCs (13.6 +/- 0.3) after UVA exposure. There was statistical difference between these two cell lines in ROS level upon UVA irradiation (P = 0.024). CONCLUSION: The mutation in Dct causes hypo-pigmented phenotype in cultured slaty MCs, inhibits melanosome maturation and decreases anti-oxidative capacity especially in the presence of UVA-induced oxidative stress.
Asunto(s)
Oxidorreductasas Intramoleculares/genética , Melanosomas/metabolismo , Mutación , Estrés Oxidativo , Animales , Células Cultivadas , Melaninas/biosíntesis , Melanocitos/citología , Melanosomas/ultraestructura , Ratones , Ratones Endogámicos C57BLRESUMEN
BACKGROUND: Limited cutaneous systemic sclerosis is one subtype of systemic sclerosis which is characterized by a prototypic multisystem fibrotic disorder. OBJECTIVE: This study aimed to further investigate the pathological mechanism of limited cutaneous systemic sclerosis (lcSSc). METHODS: The dataset GSE76807 generated from 10 lcSSc patients and five healthy controls was used. After the preprocessing of the original data, differentially expressed genes (DEGs) were identified and then performed functional analysis, protein-protein interaction (PPI) network and module analysis. Additionally, the transcription factors (TFs) and miRNAs which potentially regulating DEGs were identified and the co-regulatory network was constructed. Finally, DEGs targeted by current drugs were identified. Real-time quantitative PCR analyses of some DEGs in mice with lcSSc were performed. RESULTS: Total 203 up-regulated and 189 down-regulated DEGs were obtained. The up-regulated genes were enriched in protein interactions at the synapses neuronal system, NCAM1 interactions, and CREB phosphorylation through the activation of CaMKII, while, cilium assembly, and endothelial form of nitric oxide synthase (eNOS) activation were enriched by down-regulated genes. SCRT2 and RABEP1 regulated by miR-218 were hub nodes in the network. DRD4 and GRIN2D were the main drug targets. RABEP1 and SSB were found lowly expressed in mice model with lcSSc. CONCLUSION: Endothelial form of NOS activation would be suppressed, and the process of neuronal migration and outgrowth would be activated to participant in the pathological mechanism of lcSSc.