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International Journal of Molecular... Sep 2023The previous study successfully established an expression strain of ζ-carotene-like compounds (CLC) and demonstrated its remarkable antioxidant activity, which...
The previous study successfully established an expression strain of ζ-carotene-like compounds (CLC) and demonstrated its remarkable antioxidant activity, which exhibited resistance to photodamage caused by UVB radiation on the skin following gavage administration. The objective of this study was to investigate the impact and mechanism of CLC on UVB-induced skin damage through topical application. Cell viability, anti-apoptotic activity, ROS scavenging ability, the inhibition of melanin synthesis, the regulation of inflammatory factors and collagen deposition were assessed in cells and mice using qRT-PCR, WB, Elisa assays, immunohistochemistry staining and biochemical kits, etc. The experimental results demonstrated that CLC-mitigated apoptosis induced by UVB irradiation up-regulated the Keap1/Nrf2/ARE antioxidant pathway to attenuate levels of ROS and inflammatory factors (NF-κB, TNF-α, IL-6 and IL-β), and suppressed MAPK/AP-1 and CAMP/PKA/CREB signaling pathways to mitigate collagen degradation, skin aging and melanin formation. In conclusion, this study underscored the potential of CLC as a safe and efficacious source of antioxidants, positioning it as a promising ingredient in the formulation of cosmetics targeting anti-aging, skin brightening and sunburn repair.
PubMed: 37762273
DOI: 10.3390/ijms241813970 -
Pharmaceutics Aug 2023Malignant melanoma poses a significant global health burden. It is the most aggressive and lethal form of skin cancer, attributed to various risk factors such as UV... (Review)
Review
Malignant melanoma poses a significant global health burden. It is the most aggressive and lethal form of skin cancer, attributed to various risk factors such as UV radiation exposure, genetic modifications, chemical carcinogens, immunosuppression, and fair complexion. Photodynamic therapy is a promising minimally invasive treatment that uses light to activate a photosensitizer, resulting in the formation of reactive oxygen species, which ultimately promote cell death. When selecting photosensitizers for melanoma photodynamic therapy, the presence of melanin should be considered. Melanin absorbs visible radiation similar to most photosensitizers and has antioxidant properties, which undermines the reactive species generated in photodynamic therapy processes. These characteristics have led to further research for new photosensitizing platforms to ensure better treatment results. The development of photosensitizers has advanced with the use of nanotechnology, which plays a crucial role in enhancing solubility, optical absorption, and tumour targeting. This paper reviews the current approaches (that use the synergistic effect of different photosensitizers, nanocarriers, chemotherapeutic agents) in the photodynamic therapy of melanoma.
PubMed: 37631339
DOI: 10.3390/pharmaceutics15082124 -
International Journal of Molecular... Nov 2023is a major pathogen causing anthracnose in Chinese flowering cabbage (), posing a significant threat to the Chinese flowering cabbage industry. The conidia of...
is a major pathogen causing anthracnose in Chinese flowering cabbage (), posing a significant threat to the Chinese flowering cabbage industry. The conidia of germinate and form melanized infection structures called appressoria, which enable penetration of the host plant's epidermal cells. However, the molecular mechanism underlying melanin biosynthesis in remains poorly understood. In this study, we identified two enzymes related to DHN-melanin biosynthesis in : ChPks and ChThr1. Our results demonstrate that the expression levels of genes and were significantly up-regulated during hyphal and appressorial melanization processes. Furthermore, knockout of the gene resulted in a blocked DHN-melanin biosynthetic pathway in hyphae and appressoria, leading to increased sensitivity of the Δ mutant to cell-wall-interfering agents as well as decreased turgor pressure and pathogenicity. It should be noted that although the Δ mutant still exhibited melanin accumulation in colonies and appressoria, its sensitivity to cell-wall-interfering agents and turgor pressure decreased compared to wild-type strains; however, complete loss of pathogenicity was not observed. In conclusion, our results indicate that DHN-melanin plays an essential role in both pathogenicity and cell wall integrity in . Specifically, ChPks is crucial for DHN-melanin biosynthesis while deficiency of ChThr1 does not completely blocked melanin production.
Topics: Virulence; Melanins; Colletotrichum; Cell Wall
PubMed: 37958874
DOI: 10.3390/ijms242115890 -
World Journal of Microbiology &... Nov 2023Melanin is a brown-black pigment with significant roles in various biological processes. The tyrosinase enzyme catalyzes the conversion of tyrosine to melanin and has...
Tyrosinase enzyme purification and immobilization from Pseudomonas sp. EG22 using cellulose coated magnetic nanoparticles: characterization and application in melanin production.
Melanin is a brown-black pigment with significant roles in various biological processes. The tyrosinase enzyme catalyzes the conversion of tyrosine to melanin and has promising uses in the pharmaceutical and biotechnology sectors. This research aims to purify and immobilize the tyrosinase enzyme from Pseudomonas sp. EG22 using cellulose-coated magnetic nanoparticles. Various techniques were utilized to examine the synthesized nanoparticles, which exhibited a spherical shape with an average diameter of 12 nm and a negative surface potential of - 55.7 mV with a polydispersity index (PDI) of 0.260. Comparing the immobilized magnetic tyrosinase enzyme with the free enzyme, the study's findings showed that the immobilized tyrosinase enzyme had optimal activity at a pH of 6 and a temperature of 35 °C, and its activity increased as the concentration of tyrosine increased. The study investigated the antibacterial and anticancer bioactivity of the enzyme's melanin product and found that it exhibited potential antibacterial activity against a multi-drug resistant strain including S. aureus and E. coli. The produced melanin also demonstrated the potential to decrease cell survival and induce apoptosis in initiation cells.
Topics: Monophenol Monooxygenase; Melanins; Cellulose; Magnetite Nanoparticles; Pseudomonas; Escherichia coli; Staphylococcus aureus; Enzymes, Immobilized; Tyrosine; Anti-Bacterial Agents
PubMed: 37947912
DOI: 10.1007/s11274-023-03796-w -
Journal of Biomedical Optics Jan 2024The classification of melasma is critical for correct clinical diagnosis, treatment selection, and postoperative measures. However, preoperative quantitative...
SIGNIFICANCE
The classification of melasma is critical for correct clinical diagnosis, treatment selection, and postoperative measures. However, preoperative quantitative determination of melasma type remains challenging using conventional Wood's lamp and optical dermoscopy techniques.
AIM
Using photoacoustic microscopy (PAM) to simultaneously obtain the two diagnostic indicators of melanin and blood vessels for melasma classification and perform quantitative analysis to finally achieve accurate classification, rather than relying solely on physicians' experience.
APPROACH
First, the patients were classified by experienced dermatologists with Wood's lamp and optical dermoscopy. Next, the patients were examined using the PAM imaging system. Further, the horizontal section images ( plane) of epidermal melanin and dermal vascular involvement were extracted from the 3D photoacoustic imaging results, which are important basis for PAM to quantitatively classify melasma.
RESULTS
PAM can quantitatively reveal epidermal thickness and dermal vascular morphology in each case and obtain the quantitative diagnostic indicators of melanin and blood vessels. The mean vascular diameter in lesional skin () of epidermal M+V-type was much larger than that in non-lesional skin (), and the mean vascular density in lesional skin was more than three times that in non-lesional skin. Importantly, vascular diameter and density are important parameters for distinguishing M type from M+V type.
CONCLUSIONS
PAM can obtain the data of epidermal thickness, pigment depth, subcutaneous vascular diameter, and vascular density, and realize the dual standard quantitative melasma classification by combining the parameters of melanin and blood vessels. In addition, PAM can provide new diagnostic information for uncertain melasma types and further refine the typing.
Topics: Humans; Microscopy; Melanins; Pilot Projects; Epidermis; Melanosis
PubMed: 37927370
DOI: 10.1117/1.JBO.29.S1.S11504 -
Scientific Reports Feb 2024Melanin, the most abundant skin chromophore, is produced by melanocytes and is one of the key components responsible for mediating the skin's response to ultraviolet...
Melanin, the most abundant skin chromophore, is produced by melanocytes and is one of the key components responsible for mediating the skin's response to ultraviolet radiation (UVR). Because of its antioxidant, radical scavenging, and broadband UV absorbing properties, melanin reduces the penetration of UVR into the nuclei of keratinocytes. Despite its long-established photoprotective role, there is evidence that melanin may also induce oxidative DNA damage in keratinocytes after UV exposure and therefore be involved in the development of melanoma. The present work aimed at evaluating the dependence of UV-induced DNA damage on melanin content and distribution, using reconstructed human epidermis (RHE) models. Tanned and light RHE were irradiated with a 233 nm UV-C LED source at 60 mJ/cm and a UV lamp at 3 mJ/cm. Higher UV-mediated free radicals and DNA damage were detected in tanned RHE with significantly higher melanin content than in light RHE. The melanin distribution in the individual models can explain the lack of photoprotection. Fluorescence lifetime-based analysis and Fontana-Masson staining revealed a non-homogeneous distribution and absence of perinuclear melanin in the tanned RHE compared to the in vivo situation in humans. Extracellularly dispersed epidermal melanin interferes with photoprotection of the keratinocytes.
Topics: Humans; Ultraviolet Rays; Melanins; Epidermis; Skin; Melanocytes
PubMed: 38347037
DOI: 10.1038/s41598-024-53941-0 -
Clinical, Cosmetic and Investigational... 2024Vitiligo is an autoimmune disease characterized by loss of skin pigmentation and currently has no effective treatment. This study aimed to investigate the function of...
BACKGROUND
Vitiligo is an autoimmune disease characterized by loss of skin pigmentation and currently has no effective treatment. This study aimed to investigate the function of SIRT7, being an important desuccinylase mediating multiple disease progression, and its mechanism in vitiligo progression.
METHODS
Normal human melanocytes (NHM) PIG1 and vitiligo human melanocytes (VHM) PIG3V were utilized in this research. The role of sirtuin 7 (SIRT7) and Ezrin (EZR) on melanin synthesis was investigated by detecting tyrosinase activity, melanin content, α-MSH levels, and the protein levels of melanin-related markers. The function of EZR was identified via rescue experiments, while the underlying mechanism was investigated via bioinformatic analysis, co-immunoprecipitation (co-IP), immunoprecipitation (IP), and Western blot techniques.
RESULTS
Results showed that only SIRT7 was highly expressed in vitiligo human melanocytes, where knockingdown SIRT7 translated into increased melanin synthesis in melanocytes. Mechanistically, SIRT7 knockdown promoted the succinylation of EZR at the Lys (K)60 site. Moreover, overexpressing EZR induced higher melanin synthesis in melanocytes, while its knocking down exerted the opposite effect by inhibiting SIRT7 knockdown-induced melanin synthesis.
CONCLUSION
SIRT7 inhibited melanin synthesis in melanocytes by suppressing the succinylation of EZR. These findings are envisaged to provide a novel theoretical basis for vitiligo treatment.
PubMed: 38933605
DOI: 10.2147/CCID.S462280 -
MSystems Aug 2023Microbial necromass contributes significantly to both soil carbon (C) persistence and ecosystem nitrogen (N) availability, but quantitative estimates of C and N movement...
Microbial necromass contributes significantly to both soil carbon (C) persistence and ecosystem nitrogen (N) availability, but quantitative estimates of C and N movement from necromass into soils and decomposer communities are lacking. Additionally, while melanin is known to slow fungal necromass decomposition, how it influences microbial C and N acquisition as well as elemental release into soils remains unclear. Here, we tracked decomposition of isotopically labeled low and high melanin fungal necromass and measured C and N accumulation in surrounding soils and microbial communities over 77 d in a temperate forest in Minnesota, USA. Mass loss was significantly higher from low melanin necromass, corresponding with greater C and N soil inputs. A taxonomically and functionally diverse array of bacteria and fungi was enriched in C and/or N at all sampling points, with enrichment being consistently higher on low melanin necromass and earlier in decomposition. Similar patterns of preferential C and N enrichment of many bacterial and fungal genera early in decomposition suggest that both microbial groups co-contribute to the rapid assimilation of resource-rich soil organic matter inputs. While overall richness of taxa enriched in C was higher than in N for both bacteria and fungi, there was a significant positive relationship between C and N in co-enriched taxa. Collectively, our results demonstrate that melanization acts as a key ecological trait mediating not only fungal necromass decomposition rate but also necromass C and N release and that both elements are rapidly co-utilized by diverse bacterial and fungal decomposers in natural settings. IMPORTANCE Recent studies indicate that microbial dead cells, particularly those of fungi, play an important role in long-term carbon persistence in soils. Despite this growing recognition, how the resources within dead fungal cells (also known as fungal necromass) move into decomposer communities and soils are poorly quantified, particularly in studies based in natural environments. In this study, we found that the contribution of fungal necromass to soil carbon and nitrogen availability was slowed by the amount of melanin present in fungal cell walls. Further, despite the overall rapid acquisition of carbon and nitrogen from necromass by a diverse range of both bacteria and fungi, melanization also slowed microbial uptake of both elements. Collectively, our results indicate that melanization acts as a key ecological trait mediating not only fungal necromass decomposition rate, but also necromass carbon and nitrogen release into soil as well as microbial resource acquisition.
Topics: Soil; Carbon; Nitrogen; Melanins; Fungi; Bacteria; Microbiota
PubMed: 37338274
DOI: 10.1128/msystems.00390-23 -
The Journal of Dermatological Treatment Dec 2023Q-switched neodymium-yttrium aluminum-garnet (Q-switched Nd:YAG) laser has been reported as an effective treatment for nevus of Ota and acquired bilateral nevus of...
Q-switched neodymium-yttrium aluminum-garnet (Q-switched Nd:YAG) laser has been reported as an effective treatment for nevus of Ota and acquired bilateral nevus of Ota-like macules (ABNOM). Data on ectopic Mongolian spots have rarely been reported.The present study was performed to investigate the treatment efficacy of a high-fluence 1064 nm Q-switched Nd:YAG laser without tissue whitening in ectopic Mongolian spots.We included 61 patients with ectopic Mongolian spots, and 70 lesions were examined. Thirty-three lesions were treated with a high-fluence 1064 nm Q-switched Nd:YAG laser, and 38 lesions were observed without treatment. The results were assessed using a 5-quantile grading scale and melanin index using a Mexameter®.Mean follow-up duration was 14.1 ± 6.8 months for the treatment group and 17.8 ± 10.0 months for the observation group. Mean 5-quintile grading scale at final follow-up was statistically different ( < 0.001) between the two groups (treatment: 2.85 ± 1.00, observation: 0.49 ± 0.73). There was a significant difference ( < 0.001) in the Δ melanin index (initial melanin index - final melanin index) between the observation (7.1 ± 62.7) and treatment (156.7 ± 78.4) groups.High-fluence Q-switched Nd:YAG laser without tissue whitening showed good results and was well-tolerated in treating ectopic Mongolian spots.
Topics: Humans; Lasers, Solid-State; Mongolian Spot; Nevus of Ota; Melanins; Treatment Outcome; Skin Neoplasms
PubMed: 37781886
DOI: 10.1080/09546634.2023.2255057 -
ACS Applied Materials & Interfaces Oct 2023Photoacoustics (PA) is gaining increasing credit among biomolecular imaging methodologies by virtue of its poor invasiveness, deep penetration, high spatial resolution,...
Photoacoustics (PA) is gaining increasing credit among biomolecular imaging methodologies by virtue of its poor invasiveness, deep penetration, high spatial resolution, and excellent endogenous contrast, without the use of any ionizing radiation. Recently, we disclosed the excellent PA response of a self-structured biocompatible nanoprobe, consisting of ternary hybrid nanoparticles with a silver core and a melanin component embedded into a silica matrix. Although preliminary evidence suggested a crucial role of the Ag sonophore and the melanin-containing nanoenvironment, whether and in what manner the PA response is controlled and affected by the self-structured hybrid nanosystems remained unclear. Because of their potential as multifunctional platforms for biomedical applications, a detailed investigation of the metal-polymer-matrix interplay underlying the PA response was undertaken to understand the physical and chemical factors determining the enhanced response and to optimize the architecture, composition, and performance of the nanoparticles for efficient imaging applications. Herein, we provide the evidence for a strong synergistic interaction between eumelanin and Ag which suggests an important role in the in situ-generated metal-organic interface. In particular, we show that a strict ratio between melanin and silver precursors and an accurate choice of metal nanoparticle dimension and the kind of metal are essential for achieving strong enhancements of the PA response. Systematic variation of the metal/melanin component is thus shown to offer the means of tuning the stability and intensity of the photoacoustic response for various biomedical and theranostic applications.
Topics: Melanins; Silver; Silicon Dioxide; Nanoparticles; Metal Nanoparticles; Polymers; Photoacoustic Techniques
PubMed: 37774145
DOI: 10.1021/acsami.3c13523