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Pheomelanin

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https://www.readbyqxmd.com/read/28132436/the-potent-pro-oxidant-activity-of-rhododendrol-eumelanin-induces-cysteine-depletion-in-b16-melanoma-cells
#1
Shosuke Ito, Masae Okura, Kazumasa Wakamatsu, Toshiharu Yamashita
RS-4-(4-Hydroxyphenyl)-2-butanol (rhododendrol, RD), a skin-whitening agent, is known to induce leukoderma in some people. To explore the mechanism underlying this effect, we previously showed that the oxidation of RD with mushroom or human tyrosinase produces cytotoxic quinone oxidation products. We then examined the metabolism of RD in B16F1 melanoma cells in vitro and detected RD-pheomelanin and RD-quinone bound to non-protein and protein thiols. In this study, we examined the changes in glutathione (GSH) and cysteine in B16 cells exposed to RD for up to 24 h...
January 2017: Pigment Cell & Melanoma Research
https://www.readbyqxmd.com/read/28024137/-secrets-of-the-red-headed
#2
REVIEW
Zygmunt Zdrojewicz, Małgorzata Kowalik, Adam Jagodziński
Only 1-2% of people is red-headed but in the Russian Udmurt Republic or United Kingdom they can be met more often. A specific variant of MC1R gene (R allele) is responsible for the red hair. The gene encodes a receptor for melanocortins. These substances stimulate melanocytes to product melanin- a dye of the skin which is transported to keratinocytes. It protects a cellular nucleus from ultraviolet radiation. Melanin has two types: eumelanin which is dark brown or even black and red/orange pheomelanin. The second one is mostly observed in red-headed which is caused by R allele...
December 22, 2016: Polski Merkuriusz Lekarski: Organ Polskiego Towarzystwa Lekarskiego
https://www.readbyqxmd.com/read/27988976/adaptive-downregulation-of-pheomelanin-related-slc7a11-gene-expression-by-environmentally-induced-oxidative-stress
#3
Ismael Galván, Ângela Inácio, Ana Angela Romero-Haro, Carlos Alonso-Alvarez
Pheomelanin is a sulphur-containing yellow-to-reddish pigment whose synthesis consumes the main intracellular antioxidant (glutathione; GSH) and its precursor cysteine. Cysteine used for pheomelanogenesis cannot be used for antioxidant protection. We tested whether the expression of Slc7a11, the gene regulating the transport of cysteine to melanocytes for pheomelanogenesis, is environmentally influenced when cysteine/GSH are most required for antioxidant protection. We found that zebra finches Taeniopygia guttata developing pheomelanin-pigmented feathers during a 12-day exposure to the pro-oxidant diquat dibromide downregulated the expression of Slc7a11 in feather melanocytes, but not the expression of other genes that affect pheomelanogenesis by mechanisms different from cysteine transport such as MC1R and Slc45a2...
December 18, 2016: Molecular Ecology
https://www.readbyqxmd.com/read/27904077/synthesis-characterization-and-evaluation-of-thiazolidine-derivatives-of-cysteine-for-suppressing-eumelanin-production
#4
Yusuke Amino, Yoshinobu Takino, Megumi Kaneko, Fumie Ookura, Mai Yamamoto, Tatsuki Kashiwagi, Keiji Iwasaki
In the pathway of melanin biosynthesis, cysteine (Cys) is utilized for the synthesis of pheomelanin. Accordingly, Cys is considered to suppress the formation of brown-black eumelanin. Although attempts have been made to utilize Cys and its derivatives as skin-whitening agents, their instability and odor hinders their application as a cosmetic agent. Herein, N-acetyl-2-methylthiazolidine-2,4-dicarboxylic acid ethyl ester (AcCP2Et) was proposed as a candidate for a stable and prolonged-release derivative of Cys to inhibit dopachrome formation after its degradation in melanocytes...
2016: Chemical & Pharmaceutical Bulletin
https://www.readbyqxmd.com/read/27892516/in-vivo-coherent-raman-imaging-of-the-melanomagenesis-associated-pigment-pheomelanin
#5
Hequn Wang, Sam Osseiran, Vivien Igras, Alexander J Nichols, Elisabeth M Roider, Joachim Pruessner, Hensin Tsao, David E Fisher, Conor L Evans
Melanoma is the most deadly form of skin cancer with a yearly global incidence over 232,000 patients. Individuals with fair skin and red hair exhibit the highest risk for developing melanoma, with evidence suggesting the red/blond pigment known as pheomelanin may elevate melanoma risk through both UV radiation-dependent and -independent mechanisms. Although the ability to identify, characterize, and monitor pheomelanin within skin is vital for improving our understanding of the underlying biology of these lesions, no tools exist for real-time, in vivo detection of the pigment...
November 28, 2016: Scientific Reports
https://www.readbyqxmd.com/read/27671997/not-another-type-of-potato-mc1r-and-the-russet-coloration-of-burmese-cats
#6
N A Gustafson, B Gandolfi, L A Lyons
The Burmese is a breed of domestic cat that originated in Southeast Asia and was further developed in the United States. Variants in melanocortin 1 receptor (MC1R) causes common coat colour phenotypes in a variety of mammalian species but only limited colour variation in the domestic cat. Known as the extension (E) locus, melanocortin 1 receptor (MC1R) interacts with the agouti locus to produce the eumelanin and pheomelanin pigments. Recently, a novel reddish coloration, which is termed russet, was identified in the Burmese cat breed...
September 27, 2016: Animal Genetics
https://www.readbyqxmd.com/read/27664794/mc1r-variants-affect-the-expression-of-melanocortin-and-melanogenic-genes-and-the-association-between-melanocortin-genes-and-coloration
#7
Luis M San-Jose, Anne-Lyse Ducrest, Valérie Ducret, Céline Simon, Hannes Richter, Kazumasa Wakamatsu, Alexandre Roulin
The melanocortin-1 receptor (MC1R) gene influences coloration by altering the expression of genes acting downstream in the melanin synthesis. MC1R belongs to the melanocortin system, a genetic network coding for the ligands that regulate MC1R and other melanocortin receptors controlling different physiological and behavioural traits. The impact of MC1R variants on these regulatory melanocortin genes was never considered, even though MC1R mutations could alter the influence of these genes on coloration (e.g...
September 24, 2016: Molecular Ecology
https://www.readbyqxmd.com/read/27563719/integration-of-next-generation-sequencing-and-epr-analysis-to-uncover-molecular-mechanism-underlying-shell-color-variation-in-scallops
#8
Xiujun Sun, Zhihong Liu, Liqing Zhou, Biao Wu, Yinghui Dong, Aiguo Yang
The Yesso scallop Patinopecten yessoensis displays polymorphism in shell colors, which is of great interest for the scallop industry. To identify genes involved in the shell coloration, in the present study, we investigate the transcriptome differences by Illumina digital gene expression (DGE) analysis in two extreme color phenotypes, Red and White. Illumina sequencing yields a total of 62,715,364 clean sequence reads, and more than 85% reads are mapped into our previously sequenced transcriptome. There are 25 significantly differentially expressed genes between Red and White scallops...
2016: PloS One
https://www.readbyqxmd.com/read/27505632/aerobic-photoreactivity-of-synthetic-eumelanins-and-pheomelanins-generation-of-singlet-oxygen-and-superoxide-anion
#9
Grzegorz Szewczyk, Andrzej Zadlo, Michal Sarna, Shosuke Ito, Kazumasa Wakamatsu, Tadeusz Sarna
In this work, we examined photoreactivity of synthetic eumelanins, formed by autooxidation of DOPA, or enzymatic oxidation of 5,6-dihydroxyindole-2-carboxylic acid and synthetic pheomelanins obtained by enzymatic oxidation of 5-S-cysteinyldopa or 1:1 mixture of DOPA and cysteine. Electron paramagnetic resonance oximetry and spin trapping were used to measure oxygen consumption and formation of superoxide anion induced by irradiation of melanin with blue light, and time-resolved near-infrared luminescence was employed to determine the photoformation of singlet oxygen between 300 and 600 nm...
November 2016: Pigment Cell & Melanoma Research
https://www.readbyqxmd.com/read/27504027/the-role-of-melanin-pathways-in-extremotolerance-and-virulence-of-fonsecaea-revealed-by-de-novo-assembly-transcriptomics-using-illumina-paired-end-sequencing
#10
X Q Li, B L Guo, W Y Cai, J M Zhang, H Q Huang, P Zhan, L Y Xi, V A Vicente, B Stielow, J F Sun, G S de Hoog
Melanisation has been considered to be an important virulence factor of Fonsecaea monophora. However, the biosynthetic mechanisms of melanisation remain unknown. We therefore used next generation sequencing technology to investigate the transcriptome and digital gene expression data, which are valuable resources to better understand the molecular and biological mechanisms regulating melanisation in F. monophora. We performed de novo transcriptome assembly and digital gene expression (DGE) profiling analyses of parent (CBS 122845) and albino (CBS 125194) strains using the Illumina RNA-seq system...
2016: Studies in Mycology
https://www.readbyqxmd.com/read/27426874/non-invasive-quantification-of-melanin-in-the-stratum-corneum-a-novel-indicator-of-skin-lesions-in-pigmentation-diseases
#11
H Matsunaka, Y Yamamoto, F Furukawa
BACKGROUND/PURPOSE: Skin melanin content is an important indicator for ascertaining the pathology of skin pigmentation diseases, but its analysis necessitates a biopsy or other means of collecting tissue, posing a considerable burden to the patient, and making it difficult to observe how a given skin site changes over time. Here, we aimed to establish a non-invasive method for quantifying the eumelanin and pheomelanin content of the stratum corneum. METHODS: Sun-exposed and non-exposed samples from 10 healthy Japanese subjects were compared...
July 18, 2016: Skin Research and Technology
https://www.readbyqxmd.com/read/27356601/from-tyrosine-to-melanin-signaling-pathways-and-factors-regulating-melanogenesis
#12
Zuzanna Rzepka, Ewa Buszman, Artur Beberok, Dorota Wrześniok
Melanins are natural pigments of skin, hair and eyes and can be classified into two main types: brown to black eumelanin and yellow to reddish-brown pheomelanin. Biosynthesis of melanins takes place in melanosomes, which are specialized cytoplasmic organelles of melanocytes - dendritic cells located in the basal layer of the epidermis, uveal tract of the eye, hair follicles, as well as in the inner ear, central nervous system and heart. Melanogenesis is a multistep process and begins with the conversion of amino acid L-tyrosine to DOPAquinone...
June 30, 2016: Postȩpy Higieny i Medycyny Doświadczalnej
https://www.readbyqxmd.com/read/27224206/pheomelanin-in-the-secondary-sexual-characters-of-male-parasitoid-wasps-hymenoptera-pteromalidae
#13
Alberto Jorge García, Carlo Polidori, José Luis Nieves-Aldrey
The occurrence and distribution of eumelanin and pheomelanin, the most prevalent biological pigments, has been rarely investigated in insects. Particularly yellowish to brownish body parts, which in many vertebrates are associated with pheomelanin, are visible in many insects but their chemical nature was rarely examined to a similar detail. Here, by using Dispersive Raman spectroscopy analysis, we found both eumelanin and pheomelanin in different body parts of male parasitoid wasps of three species of the genus Mesopolobus (Hymenoptera: Pteromalidae), which are known to have species-specific spots and coloured stripes on the legs and/or antennae which are displayed to females during courtship...
July 2016: Arthropod Structure & Development
https://www.readbyqxmd.com/read/27196900/-fifty-shades-of-black-and-red-or-how-carboxyl-groups-fine-tune-eumelanin-and-pheomelanin-properties
#14
REVIEW
Raffaella Micillo, Lucia Panzella, Kenzo Koike, Giuseppe Monfrecola, Alessandra Napolitano, Marco d'Ischia
Recent advances in the chemistry of melanins have begun to disclose a number of important structure-property-function relationships of crucial relevance to the biological role of human pigments, including skin (photo) protection and UV-susceptibility. Even slight variations in the monomer composition of black eumelanins and red pheomelanins have been shown to determine significant differences in light absorption, antioxidant, paramagnetic and redox behavior, particle morphology, surface properties, metal chelation and resistance to photo-oxidative wear-and-tear...
May 17, 2016: International Journal of Molecular Sciences
https://www.readbyqxmd.com/read/27173400/artificial-pheomelanin-nanoparticles-and-their-photo-sensitization-properties
#15
Jung Pyo, Kuk-Youn Ju, Jin-Kyu Lee
Pheomelanin-type nanoparticles (PMNPs) were synthesized through a simple oxidative polymerization of 3,4-dihydroxyphenylalanine (DOPA) in the presence of cysteine by KMnO4. The synthesized PMNPs had a diameter of approximately 100nm, exhibited high dispersion stability in neutral water and various culture media and possessed similar morphology to naturally occurring pheomelanins. The efficiency of photoinduced generation of hydroxyl radicals from PMNPs was determined and related in vitro cell experiments that were carried out, with data being compared to those from eumelanin-type nanoparticles (EMNPs) and natural sepia melanin nanoparticles...
July 2016: Journal of Photochemistry and Photobiology. B, Biology
https://www.readbyqxmd.com/read/27128906/the-glutathione-derivative-gsh-monoethyl-ester-may-effectively-whiten-skin-but-gsh-does-not
#16
Bo Young Chung, So Ra Choi, Ik Jun Moon, Chun Wook Park, Young-Hoon Kim, Sung Eun Chang
Glutathione in its reduced form (GSH) is an antioxidant and also is involved in pheomelanin formation. Thus, it has been long believed that GSH has a skin whitening effect. However, its actual or direct effect is unproven. We evaluated the anti-melanogenic effects of GSH and its derivatives in vitro. We examined change of melanogenesis and its related proteins by GSH itself and its derivatives, including GSH monoethyl ester (GSH-MEE), GSH diethyl ester (GSH-DEE) and GSH monoisopropyl ester (GSH-MIPE) in Melan-A cells, Mel-Ab cells, and B16F10 cells...
April 27, 2016: International Journal of Molecular Sciences
https://www.readbyqxmd.com/read/27070583/bird-integumentary-melanins-biosynthesis-forms-function-and-evolution
#17
REVIEW
Ismael Galván, Francisco Solano
Melanins are the ubiquitous pigments distributed in nature. They are one of the main pigments responsible for colors in living cells. Birds are among the most diverse animals regarding melanin-based coloration, especially in the plumage, although they also pigment bare parts of the integument. This review is devoted to the main characteristics of bird melanins, including updated views of the formation and nature of melanin granules, whose interest has been raised in the last years for inferring the color of extinct birds and non-avian theropod dinosaurs using resistant fossil feathers...
April 8, 2016: International Journal of Molecular Sciences
https://www.readbyqxmd.com/read/26984710/morpho-histology-of-head-kidney-of-female-catfish-heteropneustes-fossilis-seasonal-variations-in-melano-macrophage-centers-melanin-contents-and-effects-of-lipopolysaccharide-and-dexamethasone-on-melanins
#18
Ravi Kumar, K P Joy, S M Singh
In the catfish Heteropneustes fossilis, the anterior kidney is a hemopoietic tissue which surrounds the adrenal homologues, interrenal (IR) and chromaffin tissues corresponding to the adrenal cortical and adrenal medulla of higher mammals. The IR tissue is arranged in cell cords around the posterior cardinal vein (PCV) and its tributaries and secretes corticosteroids. The chromaffin tissue is scattered singly or in nests of one or more cells around the epithelial lining of the PCV or blood capillaries within the IR tissue...
October 2016: Fish Physiology and Biochemistry
https://www.readbyqxmd.com/read/26955790/quantifying-variation-in-human-scalp-hair-fiber-shape-and-pigmentation
#19
Tina Lasisi, Shosuke Ito, Kazumasa Wakamatsu, Colin N Shaw
OBJECTIVES: This study aims to evaluate the use of quantitative methods of measuring variation in scalp hair fiber shape and pigmentation and carry out exploratory data analysis on a limited sample of individuals from diverse populations in order to inform future avenues of research for the evolution of modern human hair variation. METHODS: Cross-sectional area and shape and average curvature of scalp hair fibers were quantified using ImageJ. Pigmentation was analyzed using chemical methods estimating total melanin content through spectrophotometric methods, and eumelanin and pheomelanin content through HLPC analysis of melanin-specific degradation products...
June 2016: American Journal of Physical Anthropology
https://www.readbyqxmd.com/read/26951162/uv-induced-melanin-chemiexcitation-a-new-mode-of-melanoma-pathogenesis
#20
Douglas E Brash
Mutations in sunlight-induced melanoma arise from cyclobutane pyrimidine dimers (CPDs), DNA photoproducts usually created picoseconds after an ultraviolet (UV) photon is absorbed at thymine or cytosine. Surprisingly, we found that, in melanocytes, CPDs were generated for hours after UVA or UVB exposure. These "dark CPDs" constituted the majority of CPDs in cultured human and murine melanocytes and in mouse skin, and they were most prominent in skin containing pheomelanin, the melanin responsible for blonde and red hair...
June 2016: Toxicologic Pathology
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