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Erin M Wolf Horrell, Stuart G Jarrett, Katharine M Carter, John A D'Orazio
Loss-of-function melanocortin 1 receptor (MC1R) polymorphisms are common in UV-sensitive fair-skinned individuals and are associated with blunted cAMP second messenger signaling and higher lifetime risk of melanoma because of diminished ability of melanocytes to cope with UV damage. cAMP signaling positions melanocytes to resist UV injury by up-regulating synthesis of UV-blocking eumelanin pigment and by enhancing the repair of UV-induced DNA damage. cAMP enhances melanocyte nucleotide excision repair (NER), the genome maintenance pathway responsible for the removal of mutagenic UV photolesions, through cAMP-activated protein kinase (protein kinase A)-mediated phosphorylation of the ataxia telangiectasia mutated and Rad3 related (ATR) protein on the S435 residue...
January 17, 2017: Experimental Dermatology
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
Filipe Agapito, Benedito J Costa Cabral
The supramolecular structure of melanin pigments is characterized by a high concentration of radical species. Therefore, the energetics of the radical formation in melanin building blocks is key for understanding the structure and the electronic properties of the pigments at the molecular level. Nevertheless, the radical energetics of even the simplest melanin building blocks are largely unknown. In order to address this fundamental issue, the bond dissociation enthalpies (BDEs) for the melanin monomers 5,6-dihydroxy-1H-indole-2-carboxylic acid (DHICA), 1H-indole-5,6-diol (DHI), and 1H-indole-5,6-dione (IQ) were determined through high-accuracy ab initio quantum chemistry methods...
December 22, 2016: Journal of Physical Chemistry. A
Paola Manini, Piero Margari, Christian Pomelli, Paola Franchi, Gennaro Gentile, Alessandra Napolitano, Luca Valgimigli, Cinzia Chiappe, Vincent Ball, Marco d'Ischia
Despite the growing scientific and technological relevance of polydopamine (PDA), a eumelanin-like adhesive material widely used for surface functionalization and coating, knowledge of its structural and physicochemical properties, including in particular the origin of paramagnetic behavior, is still far from being complete. Herein, we disclose the unique ability of ionic liquids (ILs) to disassemble PDA, either as a suspension or as a thin film, up to the nanoscale, and to establish specific interactions with the free radical centers exposed by deaggregation of potential investigative value...
November 23, 2016: Journal of Physical Chemistry. B
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
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
Leonardo Bruno Assis Oliveira, Tertius L Fonseca, Benedito J Costa Cabral, Kaline Coutinho, Sylvio Canuto
Theoretical results for the electronic properties of eumelanin building blocks in the gas phase and water are presented. The building blocks presently investigated include the monomeric species DHI (5,6-dihydroxyindole) or hydroquinone (HQ), DHICA (5,6-dihydroxyindole-2-carboxylic acid), indolequinone (IQ), quinone methide (MQ), two covalently bonded dimers [HM ≡ HQ + MQ and IM ≡ IQ + MQ], and two tetramers [HMIM ≡ HQ + IM, IMIM ≡ IM + IM]. The electronic properties in water were determined by carrying out sequential Monte Carlo/time dependent density functional theory calculations...
August 28, 2016: Journal of Chemical Physics
Viki B Swope, Zalfa A Abdel-Malek
The membrane bound melanocortin 1 receptor (MC1R), and the endothelin B receptor (ENDBR) are two G-protein coupled receptors that play important roles in constitutive regulation of melanocytes and their response to ultraviolet radiation (UVR), the main etiological factor for melanoma. The human MC1R is a Gs protein-coupled receptor, which is activated by its agonists α-melanocyte stimulating hormone (α-melanocortin; α-MSH) and adrenocorticotropic hormone (ACTH). The ENDBR is a Gq coupled-receptor, which is activated by Endothelin (ET)-3 during embryonic development, and ET-1 postnatally...
2016: Frontiers in Genetics
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
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...
August 9, 2016: Pigment Cell & Melanoma Research
Sonal Tina Lal, Raja Paramjeet Singh Banipal, Deepak John Bhatti, Hanuman Prasad Yadav
INTRODUCTION: Skin cancer constitutes a small but significant proportion of patients with cancer. Although the presence of eumelanin in dark skin is protective against the development of skin cancer, it is increasingly being diagnosed in the Indian population. AIM: To study the profile of skin cancer patients presenting to a tertiary hospital in Malwa area of Punjab, India. MATERIALS AND METHODS: Retrospective study was done to analyse the profile of skin cancer patients who attended the institution over one year from 1(st) December 2013 to 30(th) November 2014...
June 2016: Journal of Clinical and Diagnostic Research: JCDR
Kira E Delmore, David P L Toews, Ryan R Germain, Gregory L Owens, Darren E Irwin
Details on the genetics of behavioral and quantitative phenotypes remain limited to a few organisms. Such information is central to understanding both adaptation and speciation, as many of these phenotypes reduce gene flow between taxa [1-3]. Hybrid zones provide an ideal arena for studying this topic, as they consist of recombinant genotypes that allow genetic mapping of traits distinguishing natural populations [4]. We examined the genetic basis of migratory orientation and plumage color, both of which may contribute to speciation, in a hybrid zone between two groups of Swainson's thrushes that differ in these traits...
August 22, 2016: Current Biology: CB
Kuk-Youn Ju, Jeeun Kang, Jin Ho Chang, Jin-Kyu Lee
The contradictory biological function of eumelanin (photoprotection vs photosensitization) has long been a topic of debate in a wide range of disciplines such as chemistry, physics and biology. For understanding full spectrum of eumelanin's photobiological aspect, revealing how eumelanin's complex structural organization dictates its photophysical properties is critical step. Here, we report a practical approach to controlling the hierarchically assembled structure of natural eumelanin, which leads to disassembly of its structure into subunits and oxidized subunits, respectively...
September 12, 2016: Biomacromolecules
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
S T Williams, S Ito, K Wakamatsu, T Goral, N P Edwards, R A Wogelius, T Henkel, L F C de Oliveira, L F Maia, S Strekopytov, T Jeffries, D I Speiser, J T Marsden
Colour and pattern are key traits with important roles in camouflage, warning and attraction. Ideally, in order to begin to understand the evolution and ecology of colour in nature, it is important to identify and, where possible, fully characterise pigments using biochemical methods. The phylum Mollusca includes some of the most beautiful exemplars of biological pigmentation, with the vivid colours of sea shells particularly prized by collectors and scientists alike. Biochemical studies of molluscan shell colour were fairly common in the last century, but few of these studies have been confirmed using modern methods and very few shell pigments have been fully characterised...
2016: PloS One
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...
2016: Postȩpy Higieny i Medycyny Doświadczalnej
Timo Wolf, Tetiana Gren, Eric Thieme, Daniel Wibberg, Till Zemke, Alfred Pühler, Jörn Kalinowski
The application of genome editing technologies, like CRISPR/Cas9 for industrially relevant microorganisms, is becoming increasingly important. Compared to other methods of genetic engineering the decisive factor is that CRISPR/Cas9 is relatively easy to apply and thus time and effort can be significantly reduced in organisms, which are otherwise genetically difficult to access. Because of its many advantages and opportunities, we adopted the CRISPR/Cas9 technology for Actinoplanes sp. SE50/110, the producer of the diabetes type II drug acarbose...
August 10, 2016: Journal of Biotechnology
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
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
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
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