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1.
Diagn Pathol ; 19(1): 92, 2024 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-38961434

RESUMO

AIMS: Vitiligo is a chronic dermatological condition characterized by the progressive loss of melanocytes, for which traditional therapy has shown limited efficacy. This study aimed to establish a vitiligo model with easy operability, high repeatability, and stable depigmentation to provide a foundation for studying the pathogenesis and developing novel therapies for vitiligo. METHODS: (1) Establishing vitiligo model: Firstly, deliver B16F10 cells to the back skin of C57BL/6 J via intradermal injection (day 0), and the CD4 depletion antibody was injected intraperitoneally on day 4 and 10. Secondly, the melanoma was surgically removed on day 12. Thirdly, CD8 antibody was administered intraperitoneally every fourth day till day 30. (2) Identification of vitiligo model: H&E staining, immunohistochemistry, and immunofluorescence were used to detect the melanocytes. The melanin was detected by transmission electron microscopy (TEM), Lillie ferrous sulfate staining and L-DOPA staining. RESULTS: (1) The back skin and hair began to appear white on day 30. Melanin loss reached peak on day 60; (2) Hematoxylin and eosin (H&E) staining, immunohistochemistry and immunofluorescence results showed melanocytes were reduced. L-DOPA staining, Lillie ferrous sulfate staining and TEM results showed that melanin decreased in the epidermis. CONCLUSION: We successfully establishment a vitiligo mouse model which can be more capable to simulate the pathogenesis of human vitiligo and provide an important basis for the study of pathogenesis and therapy of vitiligo.


Assuntos
Modelos Animais de Doenças , Melanócitos , Camundongos Endogâmicos C57BL , Vitiligo , Animais , Vitiligo/patologia , Vitiligo/metabolismo , Vitiligo/terapia , Melanócitos/patologia , Melanócitos/metabolismo , Camundongos , Melaninas/metabolismo
2.
Georgian Med News ; (349): 6-11, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38963193

RESUMO

A comparative study of the morphological and functional state of the microvasculature of the substantia nigra pars compacta of the brain (SNc) and bone marrow of rats was carried out using the rotenone model of Parkinson's disease (PD) and with subsequent administration of bacterial melanin (BM). The detection of microvasculature was carried out according to the histoangiological method of Chilingaryan. Animal behavior was studied using a cylinder test. An analysis of morphometric data showed that, in comparison with control animals, experimental animals with rotenone dysfunction showed an increase in capillary diameters and a general reduction in the capillary link in SNc. Behavioral tests have shown that the animals with rotenone intoxication exhibit a form of behavior inherent in PD (freezing, immobility, apathy). Under the influence of BM, the diameter of the capillaries in the SNc approaches the norm, and the capillary link is restored. Due to the protective effect of BM in rats with rotenone intoxication, the trophism of the brain tissue increases as a result of the approach of the lumen of the vessels to the norm and the opening of new branches in the capillary network, an increase in the density of capillaries, which ensures the safety of nerve cells. Animal behavior indicators are close to normal. A comprehensive analysis of cytogenetic data of rat bone marrow was also carried out. In animals with PD, compared to controls, there is a significant increase in the amount of polyploid cells (PC) and a decrease in the level of mitotic index (MI), which usually manifests itself in inflammatory processes and is accompanied by inhibition of bone marrow hematopoiesis. Under the influence of BM, a tendency towards normalization of MI was noted and a significant decrease in the percentage of PC was obtained, which possibly indicates its beneficial effect. The data obtained suggest that BM can be used as a therapeutic agent in the treatment of PD.


Assuntos
Comportamento Animal , Modelos Animais de Doenças , Melaninas , Rotenona , Animais , Melaninas/metabolismo , Ratos , Comportamento Animal/efeitos dos fármacos , Masculino , Medula Óssea/efeitos dos fármacos , Doença de Parkinson/patologia , Parte Compacta da Substância Negra/efeitos dos fármacos , Parte Compacta da Substância Negra/patologia , Parte Compacta da Substância Negra/metabolismo , Ratos Wistar , Capilares/efeitos dos fármacos , Capilares/patologia
3.
Int J Mol Sci ; 25(13)2024 Jul 04.
Artigo em Inglês | MEDLINE | ID: mdl-39000472

RESUMO

Melanin is produced by melanocytes to protect human skin from harmful ultraviolet radiation. During skin cell renewal, melanin and dead skin cells are disposed of. However, prolonged exposure to ultraviolet rays or aging can disturb this cycle, leading to skin hyperpigmentation due to melanin accumulation. Tyrosinase is a crucial enzyme involved in melanin biosynthesis. Although various compounds, including tyrosine inhibitors, that counteract melanin accumulation have been reported, some, such as hydroquinone, are toxic and can cause vitiligo. Meanwhile, the skin is the largest organ and the outermost layer of the immune system, containing a diverse range of bacteria that produce low-toxicity compounds. In the current study, we aim to identify metabolites produced by skin microbiota that inhibit tyrosinase. Specifically, mushroom tyrosinase served as the study model. Following commensal skin bacteria screening, Corynebacterium tuberculostearicum was found to inhibit tyrosinase activity. The active compound was cyclo(l-Pro-l-Tyr); commercially available cyclo(l-Pro-l-Tyr) also exhibited inhibitory activity. Docking simulations suggested that cyclo(l-Pro-l-Tyr) binds to the substrate-binding site of mushroom tyrosinase, obstructing the substrate pocket and preventing its activity. Hence, cyclo(l-Pro-l-Tyr) might have potential applications as a cosmetic agent and food additive.


Assuntos
Corynebacterium , Monofenol Mono-Oxigenase , Pele , Monofenol Mono-Oxigenase/antagonistas & inibidores , Monofenol Mono-Oxigenase/metabolismo , Humanos , Pele/microbiologia , Pele/efeitos dos fármacos , Pele/metabolismo , Simulação de Acoplamento Molecular , Agaricales/enzimologia , Inibidores Enzimáticos/farmacologia , Peptídeos Cíclicos/farmacologia , Peptídeos Cíclicos/química , Melaninas/metabolismo , Melaninas/biossíntese
4.
Arch Microbiol ; 206(8): 355, 2024 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-39017938

RESUMO

Cryptococcus neoformans is an opportunistic pathogenic fungus that produces melanin during infection, an important virulence factor in Cryptococcal infections that enhances the ability of the fungus to resist immune defense. This fungus can synthesize melanin from a variety of substrates, including L-DOPA (L-3,4-dihydroxyphenylalanine). Since melanin protects the fungus from various stress factors such as oxidative, nitrosative, extreme heat and cold stress; we investigated the effects of environmental conditions on melanin production and survival. In this study, we investigated the effects of different pH values (5.6, 7.0 and 8.5) and temperatures (30 °C and 37 °C) on melanization and cell survival using a microtiter plate-based melanin production assay and an oxidative stress assay, respectively. In addition, the efficacy of compounds known to inhibit laccase involved in melanin synthesis, i.e., tunicamycin, ß-mercaptoethanol, dithiothreitol, sodium azide and caspofungin on melanization was evaluated and their sensitivity to temperature and pH changes was measured. The results showed that melanin content correlated with pH and temperature changes and that pH 8.5 and 30 °C, were best for melanin production. Besides that, melanin production protects the fungal cells from oxidative stress induced by hydrogen peroxide. Thus, changes in pH and temperature drastically alter melanin production in C. neoformans and it correlates with the fungal survival. Due to the limited antifungal repertoire and the development of resistance in cryptococcal infections, the investigation of environmental conditions in the regulation of melanization and survival of C. neoformans could be useful for future research and clinical phasing.


Assuntos
Cryptococcus neoformans , Melaninas , Estresse Oxidativo , Temperatura , Cryptococcus neoformans/metabolismo , Cryptococcus neoformans/efeitos dos fármacos , Melaninas/metabolismo , Concentração de Íons de Hidrogênio , Peróxido de Hidrogênio/metabolismo , Lacase/metabolismo , Tunicamicina/farmacologia , Caspofungina/farmacologia , Azida Sódica/farmacologia , Mercaptoetanol/farmacologia , Ditiotreitol/farmacologia , Criptococose/microbiologia , Viabilidade Microbiana/efeitos dos fármacos , Lipopeptídeos/farmacologia , Lipopeptídeos/metabolismo
5.
Mikrochim Acta ; 191(7): 435, 2024 06 29.
Artigo em Inglês | MEDLINE | ID: mdl-38949689

RESUMO

A novel scaffold for in situ electrochemical detection of cell biomarkers was developed using electrospun nanofibers and commercial adhesive polymeric membranes. The electrochemical sensing of cell biomarkers requires the cultivation of the cells on/near the (bio)sensor surface in a manner to preserve an appropriate electroactive available surface and to avoid the surface passivation and sensor damage. This can be achieved by employing biocompatible nanofiber meshes that allow the cells to have a normal behavior and do not alter the electrochemical detection. For a better mechanical stability and ease of handling, nylon 6/6 nanofibers were collected on commercial polymeric membranes, at an optimal fiber density, obtaining a double-layered platform. To demonstrate the functionality of the fabricated scaffold, the screening of cellular stress has been achieved integrating melanoma B16-F10 cells and the (bio)sensor components on the transducer whereas the melanin exocytosis was successfully quantified using a commercial electrode. Either directly on the surface of the (bio)sensor or spatially detached from it, the integration of cell cultures in biosensing platforms based on electrospun nanofibers represents a powerful bioanalytical tool able to provide real-time information about the biomarker release, enzyme activity or inhibition, and monitoring of various cellular events.


Assuntos
Técnicas Biossensoriais , Técnicas Eletroquímicas , Nanofibras , Nanofibras/química , Animais , Camundongos , Técnicas Eletroquímicas/métodos , Técnicas Eletroquímicas/instrumentação , Técnicas Biossensoriais/métodos , Linhagem Celular Tumoral , Melaninas , Biomarcadores/análise , Alicerces Teciduais/química , Exocitose , Melanoma Experimental/patologia , Melanoma Experimental/diagnóstico
6.
Methods Mol Biol ; 2816: 253-263, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38977604

RESUMO

Lipids are compounds involved in many biologic functions including cell structure, metabolism, energy storage and are involved in signaling. A prominent lipid in these functions is cholesterol. Cholesterol also plays a part in the signaling of melanocytes, which contain melanosomes. The maturation of these melanosomes happens during melanocyte growth. The deficit of melanogenesis or melanosome maturation is associated with ocular albinism in the eye. Aberrations of melanosome maturation are also associated with pigment dispersion syndrome. Albinism and pigment dispersion manifestations are systemic. Both melanogenesis and melanocyte maturation are affected by cholesterol metabolism. Cholesterol signaling is a part of many pathways in the body, and evaluating these signals can have implications in systemic disease processes of melanogenesis and melanosome maturation, like ocular albinism and pigment dispersion. Cholesterol is carried by lipoprotein particles. Low-density lipoprotein (LDL) is usually the transport vehicle for cholesterol to reach tissues and organelles. The LDL uptake on cells often sends out a cascade of internal signaling within the cells. We describe here LDL signaling related to lipase activity changes using enzymatic methods with a kit. We describe analyses of cholesterol esters and free cholesterol with liquid chromatography and gas chromatography with or in tandem with mass spectrometry (GC-MS and LC-MS/MS). These analyses will provide insight into melanosome maturation and melanogenesis. The methods described here are applicable to all melanocytes within the body of a model mammalian organism.


Assuntos
Colesterol , Iris , Melanócitos , Transdução de Sinais , Melanócitos/metabolismo , Humanos , Colesterol/metabolismo , Iris/metabolismo , Lipoproteínas/metabolismo , Melanossomas/metabolismo , Lipoproteínas LDL/metabolismo , Espectrometria de Massas em Tandem/métodos , Cromatografia Gasosa-Espectrometria de Massas/métodos , Cromatografia Líquida/métodos , Lipase/metabolismo , Melaninas/metabolismo , Ésteres do Colesterol/metabolismo
7.
Nat Commun ; 15(1): 5817, 2024 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-38987270

RESUMO

Respiratory infections caused by the human fungal pathogen Aspergillus fumigatus are a major cause of mortality for immunocompromised patients. Exposure to these pathogens occurs through inhalation, although the role of the respiratory epithelium in disease pathogenesis has not been fully defined. Employing a primary human airway epithelial model, we demonstrate that fungal melanins potently block the post-translational secretion of the chemokines CXCL1 and CXCL8 independent of transcription or the requirement of melanin to be phagocytosed, leading to a significant reduction in neutrophil recruitment to the apical airway both in vitro and in vivo. Aspergillus-derived melanin, a major constituent of the fungal cell wall, dampened airway epithelial chemokine secretion in response to fungi, bacteria, and exogenous cytokines. Furthermore, melanin muted pathogen-mediated calcium fluxing and hindered actin filamentation. Taken together, our results reveal a critical role for melanin interaction with airway epithelium in shaping the host response to fungal and bacterial pathogens.


Assuntos
Aspergillus fumigatus , Cálcio , Quimiocina CXCL1 , Interleucina-8 , Melaninas , Melaninas/metabolismo , Humanos , Interleucina-8/metabolismo , Cálcio/metabolismo , Quimiocina CXCL1/metabolismo , Animais , Mucosa Respiratória/metabolismo , Mucosa Respiratória/microbiologia , Camundongos , Células Epiteliais/metabolismo , Células Epiteliais/microbiologia , Quimiocinas/metabolismo , Camundongos Endogâmicos C57BL
8.
Science ; 385(6705): 194-200, 2024 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-38991070

RESUMO

Millions of hibernating bats across North America have died from white-nose syndrome (WNS), an emerging disease caused by a psychrophilic (cold-loving) fungus, Pseudogymnoascus destructans, that invades their skin. Mechanisms of P. destructans invasion of bat epidermis remain obscure. Guided by our in vivo observations, we modeled hibernation with a newly generated little brown bat (Myotis lucifugus) keratinocyte cell line. We uncovered the stealth intracellular lifestyle of P. destructans, which inhibits apoptosis of keratinocytes and spreads through the cells by two epidermal growth factor receptor (EGFR)-dependent mechanisms: active penetration during torpor and induced endocytosis during arousal. Melanin of endocytosed P. destructans blocks endolysosomal maturation, facilitating P. destructans survival and germination after return to torpor. Blockade of EGFR aborts P. destructans entry into keratinocytes.


Assuntos
Nível de Alerta , Ascomicetos , Quirópteros , Receptores ErbB , Hibernação , Queratinócitos , Animais , Apoptose , Ascomicetos/fisiologia , Ascomicetos/patogenicidade , Linhagem Celular , Quirópteros/microbiologia , Quirópteros/fisiologia , Endocitose , Receptores ErbB/metabolismo , Queratinócitos/microbiologia , Melaninas/metabolismo
9.
PLoS One ; 19(7): e0306614, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38976656

RESUMO

Pigment patterns are incredibly diverse across vertebrates and are shaped by multiple selective pressures from predator avoidance to mate choice. A common pattern across fishes, but for which we know little about the underlying mechanisms, is repeated melanic vertical bars. To understand the genetic factors that modify the level or pattern of vertical barring, we generated a genetic cross of 322 F2 hybrids between two cichlid species with distinct barring patterns, Aulonocara koningsi and Metriaclima mbenjii. We identify 48 significant quantitative trait loci that underlie a series of seven phenotypes related to the relative pigmentation intensity, and four traits related to patterning of the vertical bars. We find that genomic regions that generate variation in the level of eumelanin produced are largely independent of those that control the spacing of vertical bars. Candidate genes within these intervals include novel genes and those newly-associated with vertical bars, which could affect melanophore survival, fate decisions, pigment biosynthesis, and pigment distribution. Together, this work provides insights into the regulation of pigment diversity, with direct implications for an animal's fitness and the speciation process.


Assuntos
Ciclídeos , Melaninas , Locos de Características Quantitativas , Animais , Ciclídeos/genética , Ciclídeos/metabolismo , Melaninas/metabolismo , Melaninas/genética , Pigmentação/genética , Fenótipo , Masculino , Feminino
10.
Sensors (Basel) ; 24(13)2024 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-39001098

RESUMO

The quartz tuning fork (QTF) is a promising instrument for biosensor applications due to its advanced properties such as high sensitivity to physical quantities, cost-effectiveness, frequency stability, and high-quality factor. Nevertheless, the fork's small size and difficulty in modifying the prongs' surfaces limit its wide use in experimental research. Our study presents the development of a QTF immunosensor composed of three active layers: biocompatible natural melanin nanoparticles (MNPs), glutaraldehyde (GLU), and anti-IgG layers, for the detection of immunoglobulin G (IgG). Frequency shifts of QTFs after MNP functionalization, GLU activation, and anti-IgG immobilization were measured with an Asensis QTF F-master device. Using QTF immunosensors that had been modified under optimum conditions, the performance of QTF immunosensors for IgG detection was evaluated. Accordingly, a finite element method (FEM)-based model was produced using the COMSOL Multiphysics software program (COMSOL License No. 2102058) to simulate the effect of deposited layers on the QTF resonance frequency. The experimental results, which demonstrated shifts in frequency with each layer during QTF surface functionalization, corroborated the simulation model predictions. A modelling error of 0.05% was observed for the MNP-functionalized QTF biosensor compared to experimental findings. This study validated a simulation model that demonstrates the advantages of a simulation-based approach to optimize QTF biosensors, thereby reducing the need for extensive laboratory work.


Assuntos
Técnicas Biossensoriais , Imunoglobulina G , Melaninas , Nanopartículas , Quartzo , Imunoglobulina G/química , Imunoglobulina G/imunologia , Técnicas Biossensoriais/métodos , Técnicas Biossensoriais/instrumentação , Nanopartículas/química , Melaninas/química , Quartzo/química , Imunoensaio/métodos , Imunoensaio/instrumentação , Simulação por Computador , Anticorpos Anti-Idiotípicos/imunologia , Anticorpos Anti-Idiotípicos/química , Humanos
11.
Exp Dermatol ; 33(7): e15138, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-39005203

RESUMO

Seborrheic keratosis (SK) is a common benign tumour, often associated with hyperpigmentation. To investigate the mechanism of melanin accumulation in SK, we have conducted comprehensive gene expression and histological analyses. We obtained five pairs of skin samples, including non-lesional and SK samples, from the backs of three male Japanese participants aged 40-59 years. To examine melanocytes and keratinocytes in SK, three pairs of skin samples were separated by laser capture microdissection into the basal layer and the other layer in the epidermis. We performed a comprehensive gene expression analysis to identify differentially expressed genes between non-lesional and SK skin, followed by gene ontology and pathway analysis. We found abnormal morphogenesis and cell proliferation in the basal layer, along with increased immune response and impaired cell differentiation and metabolism in the other layer of SK. We focused on cell proliferation and differentiation, as these are directly associated with melanin accumulation. Immunohistochemical analyses of Ki67, keratin 10, and keratin 14 demonstrated the decreases in the proliferation and early differentiation of the epidermis. Contrarily, no significant changes were observed in terminal differentiation markers, filaggrin and loricrin. Although the number of melanocytes was higher in SK than in non-lesional skin, melanogenic activity showed no difference. These results indicated that melanin accumulation in SK is caused by delayed melanin excretion due to reduced turnover around the basal and spinous layers of the epidermis and melanin production due to an increased number of melanocytes. Our findings provide new insights for therapeutic approaches in SK.


Assuntos
Diferenciação Celular , Proliferação de Células , Proteínas Filagrinas , Queratinócitos , Ceratose Seborreica , Melaninas , Melanócitos , Humanos , Melanócitos/metabolismo , Melanócitos/patologia , Ceratose Seborreica/metabolismo , Ceratose Seborreica/patologia , Masculino , Melaninas/metabolismo , Pessoa de Meia-Idade , Queratinócitos/metabolismo , Adulto , Epiderme/metabolismo , Epiderme/patologia , Proteínas de Membrana
12.
Int J Mol Sci ; 25(13)2024 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-39000342

RESUMO

Post-burn hypertrophic scars often exhibit abnormal pigmentation. Exosomes play important roles in maintaining normal physiological homeostasis and in the pathological development of diseases. This study investigated the effects of the exosomes derived from hypertrophic scar fibroblasts (HTSFs) on melanocytes, which are pigment-producing cells. Normal fibroblasts (NFs) and HTSFs were isolated and cultured from normal skin and hypertrophic scar (HTS) tissue. Both the NF- and HTSF-exosomes were isolated from a cell culture medium and purified using a column-based technique. The normal human epidermal melanocytes were treated with both exosomes at a concentration of 100 µg/mL at different times. The cell proliferation, melanin content in the medium, apoptotic factors, transcription factors, melanin synthesis enzymes, signaling, signal transduction pathways, and activators of transcription factors (STAT) 1, 3, 5, and 6 were investigated. Compared with the Dulbecco's phosphate-buffered saline (DPBS)-treated controls and NF-exosomes, the HTSF-exosomes decreased the melanocyte proliferation and melanin secretion. The molecular patterns of apoptosis, proliferation, melanin synthesis, Smad and non-Smad signaling, and STATs were altered by the treatment with the HTSF-exosomes. No significant differences were observed between the DPBS-treated control and NF-exosome-treated cells. HTSF-derived exosomes may play a role in the pathological epidermal hypopigmentation observed in patients with HTS.


Assuntos
Proliferação de Células , Cicatriz Hipertrófica , Exossomos , Fibroblastos , Melaninas , Melanócitos , Transdução de Sinais , Humanos , Exossomos/metabolismo , Melanócitos/metabolismo , Fibroblastos/metabolismo , Melaninas/biossíntese , Melaninas/metabolismo , Cicatriz Hipertrófica/metabolismo , Cicatriz Hipertrófica/patologia , Apoptose , Epiderme/metabolismo , Epiderme/patologia , Células Cultivadas , Melanogênese
13.
Sci Rep ; 14(1): 13979, 2024 06 17.
Artigo em Inglês | MEDLINE | ID: mdl-38886457

RESUMO

Hyperspectral imaging (HSI) is a new emerging modality useful for the noncontact assessment of free flap perfusion. This measurement technique relies on the optical properties within the tissue. Since the optical properties of hemoglobin (Hb) and melanin overlap, the results of the perfusion assessment and other tissue-specific parameters are likely to be distorted by the melanin, especially at higher melanin concentrations. Many spectroscopic devices have been shown to struggle with a melanin related bias, which results in a clinical need to improve non-invasive perfusion assessment, especially for a more pigmented population. This study investigated the influence of skin tones on tissue indices measurements using HSI. In addition, other factors that might affect HSI, such as age, body mass index (BMI), sex or smoking habits, were also considered. Therefore, a prospective feasibility study was conducted, including 101 volunteers from whom tissue indices measurements were performed on 16 different body sites. Skin tone classification was performed using the Fitzpatrick skin type classification questionnaire, and the individual typology angle (ITA) acquired from the RGB images was calculated simultaneously with the measurements. Tissue indices provided by the used HSI-device were correlated to the possible influencing factors. The results show that a dark skin tone and, therefore, higher levels of pigmentation influence the HSI-derived tissue indices. In addition, possible physiological factors influencing the HSI-measurements were found. In conclusion, the HSI-based tissue indices can be used for perfusion assessment for people with lighter skin tone levels but show limitations in people with darker skin tones. Furthermore, it could be used for a more individual perfusion assessment if different physiological influencing factors are respected.


Assuntos
Retalhos de Tecido Biológico , Imageamento Hiperespectral , Pigmentação da Pele , Humanos , Feminino , Masculino , Adulto , Pessoa de Meia-Idade , Imageamento Hiperespectral/métodos , Pele/irrigação sanguínea , Pele/diagnóstico por imagem , Melaninas/metabolismo , Idoso , Estudos Prospectivos , Adulto Jovem , Estudos de Viabilidade , Hemoglobinas/metabolismo , Hemoglobinas/análise
14.
Food Chem ; 455: 139814, 2024 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-38824735

RESUMO

Persimmon (Diospyros kaki) leaf is widely used as a tea substitute in East Asia, offering potential health benefits. Although studies have highlighted their effects on hyperpigmentation disorders, the active components remain unidentified. This study introduces a novel approach combining LC-MS/MS-based molecular networking with AlphaFold2-enabled virtual screening to expedite the identification of bioactive components in persimmon leaf. A total of 105 compounds were identified by MS/MS analysis. Further, virtual screening identified five flavonoids with potential anti-melanogenic properties. Bioassays confirmed myricetin, quercetin, and kaempferol inhibited melanogenesis in human melanocytes in a dose-dependent manner. Biolayer interferometry assays revealed strong binding affinity between these flavonols and hsTYR, with KD values of 23.26 ± 11.77 for myricetin, 12.43 ± 0.37 for quercetin, and 14.99 ± 3.80 µM for kaempferol. Molecular dynamics simulations provided insights into the binding interactions of these flavonols with hsTYR, particularly highlighting the essential role of the 3-OH group on the C-ring. This study elucidates the bioactive components responsible for the anti-melanogenic effects of persimmon leaf, supporting their use in product development.


Assuntos
Diospyros , Extratos Vegetais , Folhas de Planta , Espectrometria de Massas em Tandem , Diospyros/química , Folhas de Planta/química , Humanos , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Melanócitos/efeitos dos fármacos , Melanócitos/metabolismo , Melanócitos/química , Flavonoides/química , Flavonoides/farmacologia , Melaninas/química , Melaninas/metabolismo , Cromatografia Líquida , Espectrometria de Massa com Cromatografia Líquida
15.
Int J Nanomedicine ; 19: 5479-5492, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38863646

RESUMO

Background: In recent years, PD-L1 has been primarily utilized as an immune checkpoint marker in cancer immunotherapy. However, due to tumor heterogeneity, the response rate to such therapies often falls short of expectations. In addition to its role in immunotherapy, PD-L1 serves as a specific target on the surface of tumor cells for targeted diagnostic and therapeutic interventions. There is an absence of a fully developed PD-L1-targeted diagnostic and therapeutic probe for clinical use, which constrains the exploration and clinical exploitation of this target. Methods and Results: In this study, we engineered a PD-L1-targeted probe with multimodal imaging and dual therapeutic functionalities utilizing organic melanin nanoparticles. Functionalization with the WL12-SH peptide endowed the nanoprobe with specific targeting capabilities. Subsequent radiolabeling with 89Zr (half-life: 100.8 hours) and chelation of Mn2+ ions afforded the probe the capacity for simultaneous PET and MRI imaging modalities. Cellular uptake assays revealed pronounced specificity, with -positive cells exhibiting significantly higher uptake than -negative counterparts (p < 0.05). Dual-modal PET/MRI imaging delineated rapid and sustained accumulation at the neoplastic site, yielding tumor-to-non-tumor (T/NT) signal ratios at 24 hours post-injection of 16.67±3.45 for PET and 6.63±0.64 for MRI, respectively. We conjugated the therapeutic radionuclide 131I (half-life: 8.02 days) to the construct and combined low-dose radiotherapy and photothermal treatment (PTT), culminating in superior antitumor efficacy while preserving a high safety profile. The tumors in the cohort receiving the dual-modality therapy exhibited significantly reduced volume and weight compared to those in the control and monotherapy groups. Conclusion: We developed and applied a novel -targeted multimodal theranostic nanoprobe, characterized by its high specificity and superior imaging capabilities as demonstrated in PET/MRI modalities. Furthermore, this nanoprobe facilitates potent therapeutic efficacy at lower radionuclide doses when used in conjunction with PTT.


Assuntos
Antígeno B7-H1 , Imageamento por Ressonância Magnética , Imagem Multimodal , Nanopartículas , Tomografia por Emissão de Pósitrons , Nanomedicina Teranóstica , Nanomedicina Teranóstica/métodos , Animais , Antígeno B7-H1/metabolismo , Tomografia por Emissão de Pósitrons/métodos , Nanopartículas/química , Humanos , Imageamento por Ressonância Magnética/métodos , Imagem Multimodal/métodos , Linhagem Celular Tumoral , Camundongos , Melaninas/química , Zircônio/química , Radioisótopos/química , Feminino , Imunoterapia/métodos
16.
Molecules ; 29(11)2024 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-38893349

RESUMO

This study aimed to isolate and purify resveratrol and oxyresveratrol from the heartwoods of Maclura cochinchinensis, and to evaluate their inhibitory effects on melanogenesis in B16F10 murine melanoma cells. A methanol maceration process yielded a crude extract comprising 24.86% of the initial mass, which was subsequently analyzed through HPTLC, HPLC, and LC-MS/MS. These analyses revealed the presence of resveratrol and oxyresveratrol at concentrations of 4.32 mg/g and 33.6 mg/g in the extract, respectively. Initial purification employing food-grade silica gel column chromatography separated the extract into two fractions: FA, exhibiting potent inhibition of both tyrosinase activity and melanogenesis, and FM, showing no such inhibitory activity. Further purification processes led to the isolation of fractions Y11 and Gn12 with enhanced concentrations of resveratrol (94.9 and 110.21 mg/g, respectively) and fractions Gn15 and Gn16 with elevated levels of oxyresveratrol (321.93 and 274.59 mg/g, respectively), all of which significantly reduced melanin synthesis. These outcomes affirm the substantial presence of resveratrol and oxyresveratrol in the heartwood of M. cochinchinensis, indicating their promising role as natural agents for skin lightening.


Assuntos
Melaninas , Melanoma Experimental , Extratos Vegetais , Resveratrol , Estilbenos , Resveratrol/farmacologia , Resveratrol/química , Extratos Vegetais/farmacologia , Extratos Vegetais/química , Animais , Camundongos , Melaninas/biossíntese , Estilbenos/farmacologia , Estilbenos/química , Melanoma Experimental/metabolismo , Melanoma Experimental/patologia , Linhagem Celular Tumoral , Monofenol Mono-Oxigenase/antagonistas & inibidores , Monofenol Mono-Oxigenase/metabolismo , Cromatografia Líquida de Alta Pressão , Espectrometria de Massas em Tandem , Melanogênese
17.
Brain Behav ; 14(6): e3573, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38898625

RESUMO

INTRODUCTION: Anorexia nervosa (AN) is a debilitating and potentially chronic eating disorder, characterized by low hedonic drive toward food, which has been linked with perturbations in both reward processing and dopaminergic activity. Neuromelanin-sensitive magnetic resonance imaging (MRI) is an emerging method to index midbrain neuromelanin-a by-product of dopaminergic synthesis. The assessment of midbrain neuromelanin, and its association with AN psychopathology and reward-related processes, may provide critical insights into reward circuit function in AN. METHODS: This study will incorporate neuromelanin-sensitive MRI into an existing study of appetitive conditioning in those with AN. Specifically, those with acute and underweight AN (N = 30), those with weight-restored AN (N = 30), and age-matched healthy controls (N = 30) will undergo clinical assessment of current and previous psychopathology, in addition to structural neuromelanin-sensitive MRI, diffusion MRI, and functional MRI (fMRI) during appetitive conditioning. CONCLUSION: This study will be among the first to interrogate midbrain neuromelanin in AN-a disorder characterized by altered dopaminergic activity. Results will help establish whether abnormalities in the midbrain synthesis of dopamine are evident in those with AN and are associated with symptomatic behavior and reduced ability to experience pleasure and reward.


Assuntos
Anorexia Nervosa , Imageamento por Ressonância Magnética , Melaninas , Mesencéfalo , Recompensa , Humanos , Melaninas/metabolismo , Anorexia Nervosa/diagnóstico por imagem , Anorexia Nervosa/metabolismo , Anorexia Nervosa/fisiopatologia , Mesencéfalo/diagnóstico por imagem , Mesencéfalo/metabolismo , Imageamento por Ressonância Magnética/métodos , Feminino , Adulto , Adulto Jovem , Adolescente , Masculino , Publicação Pré-Registro
18.
Molecules ; 29(12)2024 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-38930941

RESUMO

BACKGROUND: Androgenetic alopecia (AGA) causes thinning hair, but poor hair quality in balding areas and damage from UV radiation have been overlooked. Plant extracts like Platycladus orientalis flavonoids (POFs) may improve hair quality in AGA. This study examines POFs' effectiveness in treating AGA-affected hair and repairing UV-induced damage. METHODS: Hair samples were analyzed using scanning electron microscopy (SEM) to examine surface characteristics, electron paramagnetic resonance (EPR) spectroscopy to measure free radicals in the hair, and spectrophotometry to assess changes in hair properties. RESULTS: POFs effectively removed hydroxyl radicals from keratinocytes and had antioxidant properties. They also reduced UV-induced damage to AGA hair by mitigating the production of melanin free radicals. Following POF treatment, the reduction in peroxidized lipid loss in AGA hair was notable at 59.72%, thereby effectively delaying the progression of hair color change. Moreover, protein loss decreased by 191.1 µ/g and tryptophan loss by 15.03%, ultimately enhancing hair's tensile strength. CONCLUSION: compared to healthy hair, hair damaged by AGA shows more pronounced signs of damage when exposed to UV radiation. POFs help protect balding hair by reducing oxidative damage and slowing down melanin degradation.


Assuntos
Alopecia , Antioxidantes , Flavonoides , Cabelo , Extratos Vegetais , Raios Ultravioleta , Alopecia/tratamento farmacológico , Raios Ultravioleta/efeitos adversos , Humanos , Antioxidantes/farmacologia , Antioxidantes/química , Cabelo/efeitos dos fármacos , Cabelo/efeitos da radiação , Cabelo/química , Flavonoides/farmacologia , Flavonoides/química , Flavonoides/análise , Extratos Vegetais/farmacologia , Extratos Vegetais/química , Melaninas/metabolismo , Queratinócitos/efeitos dos fármacos
19.
Molecules ; 29(12)2024 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-38930952

RESUMO

Based on the fact that substances with a ß-phenyl-α,ß-unsaturated carbonyl (PUSC) motif confer strong tyrosinase inhibitory activity, benzylidene-3-methyl-2-thioxothiazolidin-4-one (BMTTZD) analogs 1-8 were prepared as potential tyrosinase inhibitors. Four analogs (1-3 and 5) inhibited mushroom tyrosinase strongly. Especially, analog 3 showed an inhibitory effect that was 220 and 22 times more powerful than kojic acid in the presence of l-tyrosine and l-dopa, respectively. A kinetic study utilizing mushroom tyrosinase showed that analogs 1 and 3 competitively inhibited tyrosinase, whereas analogs 2 and 5 inhibited tyrosinase in a mixed manner. A docking simulation study indicated that analogs 2 and 5 could bind to both the tyrosinase active and allosteric sites with high binding affinities. In cell-based experiments using B16F10 cells, analogs 1, 3, and 5 effectively inhibited melanin production; their anti-melanogenic effects were attributed to their ability to inhibit intracellular tyrosinase activity. Moreover, analogs 1, 3, and 5 inhibited in situ B16F10 cellular tyrosinase activity. In three antioxidant experiments, analogs 2 and 3 exhibited strong antioxidant efficacy, similar to that of the positive controls. These results suggest that the BMTTZD analogs are promising tyrosinase inhibitors for the treatment of hyperpigmentation-related disorders.


Assuntos
Agaricales , Antioxidantes , Inibidores Enzimáticos , Melaninas , Simulação de Acoplamento Molecular , Monofenol Mono-Oxigenase , Monofenol Mono-Oxigenase/antagonistas & inibidores , Monofenol Mono-Oxigenase/metabolismo , Agaricales/enzimologia , Animais , Antioxidantes/farmacologia , Antioxidantes/química , Camundongos , Inibidores Enzimáticos/farmacologia , Inibidores Enzimáticos/química , Melaninas/antagonistas & inibidores , Melaninas/biossíntese , Tiazolidinas/química , Tiazolidinas/farmacologia , Linhagem Celular Tumoral , Cinética , Melanoma Experimental/tratamento farmacológico , Melanoma Experimental/patologia , Compostos de Benzilideno/farmacologia , Compostos de Benzilideno/química , Pironas
20.
ACS Appl Mater Interfaces ; 16(25): 31950-31965, 2024 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-38861025

RESUMO

Ulcerative colitis (UC) is a recurrent chronic mucosal inflammation disease whose most significant pathological characteristics are intestinal inflammation and damaged mucosal barrier induced by reactive oxygen/nitrogen species, abnormal immune microenvironment, and intestinal microecological imbalance. Oral probiotics are a living therapy for intestinal diseases, but their clinical application is hindered by poor bacterial biological activity and insufficient intestinal retention. Here, we developed a targeted oral formulation, functionalized probiotic Lf@MPB, with Lactobacillus fermentum (Lf) as the core and modified melanin nanoparticles (MNPs) on its surface through a click reaction of tricarboxyphenylboronic acid for synergistic therapy of UC. In vitro experiments showed that Lf@MPB not only possessed strong free radical scavenging ability, reduced cellular mitochondrial polarization, and inhibited apoptosis but also significantly enhanced the viability of Lf probiotics in simulated gastrointestinal fluid. Fluorescence imaging in vivo revealed the high accumulation of Lf@MPB at the site of intestinal inflammation in dextran sulfate sodium-induced UC mice. Moreover, in vivo results demonstrated that Lf@MPB effectively alleviated oxidative stress and inflammatory response and restored the intestinal barrier. In addition, 16S rRNA gene sequencing verified that Lf@MPB could increase the abundance and diversity of intestinal microbial communities and optimize microbial composition to inhibit the progression of UC. This work combines effective antioxidant and anti-inflammatory strategies with the oral administration of functionalized probiotics to provide a promising alternative for UC treatment.


Assuntos
Colite Ulcerativa , Melaninas , Nanopartículas , Probióticos , Animais , Humanos , Masculino , Camundongos , Colite Ulcerativa/terapia , Colite Ulcerativa/tratamento farmacológico , Colite Ulcerativa/patologia , Sulfato de Dextrana , Microbioma Gastrointestinal/efeitos dos fármacos , Limosilactobacillus fermentum , Melaninas/química , Camundongos Endogâmicos C57BL , Nanopartículas/química , Probióticos/química , Probióticos/farmacologia
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