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Melanin degradation

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https://read.qxmd.com/read/30759416/combined-microscopy-and-spectroscopy-techniques-to-characterize-a-fossilized-feather-with-minimal-damage-to-the-specimen
#1
Andrea Porto Carreiro Campos, Rodrigo Tomazetto de Carvalho, Lorian Cobra Straker, Leonardo Tavares Salgado, Alexander Kellner, Marcos Farina
The study of fossil feathers has been revitalized in the last few decades and has contributed significantly to paleontological studies of dinosaurs and birds. Specific morphological and physicochemical characteristics of the microscale structures of feathers and the protein keratin are key targets when preserved during the fossilization process. Keratin is a fibrous protein that composes some hard tissues such as hair, nails and feathers. It is part of the so called intermediate filaments inside keratinocyte cells and is rich in sulfur containing amino acid cysteine...
January 31, 2019: Micron: the International Research and Review Journal for Microscopy
https://read.qxmd.com/read/30738166/effective-melanin-degradation-by-a-synergistic-laccase-peroxidase-enzyme-complex-for-skin-whitening-and-other-practical-applications
#2
Sang Kyu Shin, Jeong Eun Hyeon, Young-Chul Joo, Da Woon Jeong, Seung Kyou You, Sung Ok Han
Melanin is major cause of dark skin, which is regarded as social status in eastern Asia. As a result, researchers in cosmetic industries are developing skin whitening agents. Melanin can be decolorized by many oxidative enzymes. Laccase (CueO) from Escherichia coli and dye-decolorizing peroxidase (DyP) from Bacillus subtilis were merged with the dockerin domain of endoglucanase B from Clostridium cellulovorans. Scaffoldin has great potential to exert structural benefits that enable complementary enzyme effects...
February 6, 2019: International Journal of Biological Macromolecules
https://read.qxmd.com/read/30737353/the-bhlh-transcription-factor-devr-significantly-affects-polysaccharide-metabolism-in-aspergillus-oryzae
#3
Miao Zhuang, Zhi-Min Zhang, Long Jin, Bao-Teng Wang, Yasuji Koyama, Feng-Jie Jin
basic-region helix-loop-helix (bHLH) proteins are a superfamily of transcription factors that are often involved in the control of growth and differentiation. Recently, it has been reported that the bHLH transcription factor DevR is involved in both asexual and sexual development in A. nidulans and regulates the conidial melanin production in A. fumigatus In this study, we identified and characterized an A. oryzae gene, which showed high similarity with devR of A. nidulans and A. fumigatus In the AodevR -disrupted strain, growth was delayed and the number of conidia was decreased on CD minimal agar plates, but the conidiation could be partially recovered by adding 0...
February 8, 2019: Applied and Environmental Microbiology
https://read.qxmd.com/read/30711746/the-distribution-of-melanocytes-and-the-degradation-of-melanosomes-in-fetal-hair-follicles
#4
Li Xiao, Ru-Zhi Zhang, Wen-Yuan Zhu
There have been many studies about the formation, storage, transport and degradation of melanosomes in epidermal melanocytes but studies of melanocytes and melanosomes in fetal hair follicles (HFs) have been limited and ambiguous. The goal of this study was to investigate the distribution of melanocytes and the degradation of melanosomes in fetal HFs. After obtaining approval and informed consent for the study, a scalp specimen from a 5 month gestational age fetus was obtained and was divided into two parts...
January 25, 2019: Micron: the International Research and Review Journal for Microscopy
https://read.qxmd.com/read/30701971/influence-of-nucleophilic-amino-acids-on-enzymatic-browning-systems
#5
Nils Mertens, Franziska Mai, Marcus A Glomb
In the present study the enzymatic oxidation of gallic acid and catechin catalyzed by nashi pear polyphenol oxidase (PPO) in the presence of the amino acids lysine, arginine, or cysteine was investigated for polyphenol-amino acid adducts. HPLC analyses revealed the formation of two novel dihydrobenzothiazine carboxylic acid derivatives (8-(3',4'-dihydro-2 H-chromene-3',5',7'-triol)-3,4-dihydro-5-hydroxy-2 H-benzothiazine-3-carboxylic acid and 7-(3',4'-dihydro-2 H-chromene-3',5',7'-triol)-3,4-dihydro-5-hydroxy-2 H-benzothiazine-3-carboxylic acid) from 2'-cysteinyl catechin and 5'-cysteinyl catechin in cysteine incubations, respectively...
January 31, 2019: Journal of Agricultural and Food Chemistry
https://read.qxmd.com/read/30688436/photothermally-enhanced-detoxification-of-chemical-warfare-agent-simulants-using-bioinspired-core-shell-dopamine-melanin-metal-organic-frameworks-and-their-fabrics
#6
Aonan Yao, Xiuling Jiao, Dairong Chen, Cheng Li
Self-detoxifying materials capable of both capture and destruction of chemical warfare agents (CWAs) are highly desirable for efficient personal protection and safe handling of contaminated materials. Developing new strategies to improve CWA removal efficiency of these materials is highly relevant to CWA purification technology. Herein, we present novel photothermally enhanced catalytic detoxification of CWA simulants and its application in self-detoxifying gas filters. The material design features a well-defined core-shell nanostructure (CSN) consisting of an inner photothermal material and an outer microporous catalyst...
February 7, 2019: ACS Applied Materials & Interfaces
https://read.qxmd.com/read/30668323/a-chemical-compound-from-fruit-extract-of-juglans-mandshurica-inhibits-melanogenesis-through-p-erk-associated-mitf-degradation
#7
Ji Young Kim, Eun Jung Lee, Yuri Ahn, SeonJu Park, Seung Hyun Kim, Sang Ho Oh
BACKGROUND: Trials for regulation of abnormal hyperpigmentation from the use of natural products have been going on for years. Leaf and root extracts from Juglans mandshurica are reported to function as antioxidants and to suppress allergic dermatitis. However, studies evaluating its fruit extract and the chemical compounds from the fruit extract are lacking in dermatology fields, including melanogenesis. PURPOSE: The aim of this study is to understand the effect of the fruit extract from J...
December 10, 2018: Phytomedicine: International Journal of Phytotherapy and Phytopharmacology
https://read.qxmd.com/read/30605671/rescue-of-transgenic-alzheimer-s-pathophysiology-by-polymeric-cellular-prion-protein-antagonists
#8
Erik C Gunther, Levi M Smith, Mikhail A Kostylev, Timothy O Cox, Adam C Kaufman, Suho Lee, Ewa Folta-Stogniew, George D Maynard, Ji Won Um, Massimiliano Stagi, Jacqueline K Heiss, Austin Stoner, Geoff P Noble, Hideyuki Takahashi, Laura T Haas, John S Schneekloth, Janie Merkel, Christopher Teran, Zaha K Naderi, Surachai Supattapone, Stephen M Strittmatter
Cellular prion protein (PrPC ) binds the scrapie conformation of PrP (PrPSc ) and oligomeric β-amyloid peptide (Aβo) to mediate transmissible spongiform encephalopathy (TSE) and Alzheimer's disease (AD), respectively. We conducted cellular and biochemical screens for compounds blocking PrPC interaction with Aβo. A polymeric degradant of an antibiotic targets Aβo binding sites on PrPC with low nanomolar affinity and prevents Aβo-induced pathophysiology. We then identified a range of negatively charged polymers with specific PrPC affinity in the low to sub-nanomolar range, from both biological (melanin) and synthetic (poly [4-styrenesulfonic acid-co-maleic acid], PSCMA) origin...
January 2, 2019: Cell Reports
https://read.qxmd.com/read/30548435/visible-light-accelerates-the-ultraviolet-a-induced-degradation-of-eumelanin-and-pheomelanin
#9
Shosuke Ito, Ludger Kolbe, Gudrun Weets, Kazumasa Wakamatsu
Exposure to excess ultraviolet (UV) A radiation induces the degradation/modification of both eumelanin and pheomelanin that may be deleterious to pigmented tissues. Although the spectral distribution of solar energy comprises nearly half of visible light (VL), few studies have been conducted to examine the role of VL in the photodegradation of both types of melanin, either VL alone or in combination with UVA. In this study, we examined the effects of physiological doses of VL (150 to 300 J cm-2 ) alone or in combination with a physiological dose of UVA (20 J cm-2 ) in normal human epidermal melanocytes...
November 22, 2018: Pigment Cell & Melanoma Research
https://read.qxmd.com/read/30539256/glycerol-inhibition-of-melanin-biosynthesis-in-the-environmental-aeromonas-salmonicida-34mel-t
#10
María Elisa Pavan, Esmeralda Solar Venero, Diego E Egoburo, Esteban E Pavan, Nancy I López, M Julia Pettinari
The environmental strain Aeromonas salmonicida subsp. pectinolytica 34melT produces abundant melanin through the homogentisate pathway in several culture media, but unexpectedly not when grown in a medium containing glycerol. Using this observation as a starting point, this study investigated the underlying causes of the inhibition of melanin synthesis by glycerol, to shed light on factors that affect melanin production in this microorganism. The effect of different carbon sources on melanin formation was related to the degree of oxidation of their C atoms, as the more reduced substrates delayed melanization more than the more oxidized ones, although only glycerol completely abolished melanin production...
December 11, 2018: Applied Microbiology and Biotechnology
https://read.qxmd.com/read/30445206/dnp73-induced-degradation-of-tyrosinase-links-depigmentation-with-emt-driven-melanoma-progression
#11
Katharina Fürst, Marc Steder, Stella Logotheti, Alessandro Angerilli, Alf Spitschak, Stephan Marquardt, Toni Schumacher, David Engelmann, Ottmar Herchenröder, Ralph A W Rupp, Brigitte M Pützer
Melanoma is an aggressive cancer with poor prognosis, requiring personalized management of advanced stages and establishment of molecular markers. Melanomas derive from melanocytes, which specifically express tyrosinase, the rate-limiting enzyme of melanin-synthesis. We demonstrate that melanomas with high levels of DNp73, a cancer-specific variant of the p53 family member p73 and driver of melanoma progression show, in contrast to their less-aggressive low-DNp73 counterparts, hypopigmentation in vivo. Mechanistically, reduced melanin-synthesis is mediated by a DNp73-activated IGF1R/PI3K/AKT axis leading to tyrosinase ER-arrest and proteasomal degradation...
November 13, 2018: Cancer Letters
https://read.qxmd.com/read/30406827/bifunctional-in-vivo-role-of-laccase-exploited-in-multiple-biotechnological-applications
#12
REVIEW
Abha Sharma, Kavish Kumar Jain, Arti Jain, Mazahir Kidwai, R C Kuhad
Laccases are multicopper enzymes present in plants, fungi, bacteria, and insects, which catalyze oxidation reactions together with four electron reduction of oxygen to water. Plant, bacterial, and insect laccases have a polymerizing role in nature, implicated in biosynthesis of lignin, melanin formation, and cuticle hardening, respectively. On the other hand, fungal laccases carry out both polymerizing (melanin synthesis and fruit body formation) as well as depolymerizing roles (lignin degradation). This bifunctionality of fungal laccases can be attributed to the presence of multiple isoforms within the same as well as different genus and species...
November 8, 2018: Applied Microbiology and Biotechnology
https://read.qxmd.com/read/30322121/zerumbone-a-tropical-ginger-sesquiterpene-of-zingiber-officinale-roscoe-attenuates-%C3%AE-msh-induced-melanogenesis-in-b16f10-cells
#13
Taek-In Oh, Hye-Jeong Jung, Yoon-Mi Lee, Sujin Lee, Geon-Hee Kim, Sang-Yeon Kan, Hyeji Kang, Taerim Oh, Hyun Myung Ko, Keun-Chang Kwak, Ji-Hong Lim
Zerumbone (ZER), an active constituent of the Zingiberaceae family, has been shown to exhibit several biological activities, such as anti-inflammatory, anti-allergic, anti-microbial, and anti-cancer; however, it has not been studied for anti-melanogenic properties. In the present study, we demonstrate that ZER and Zingiber officinale (ZO) extract significantly attenuate melanin accumulation in α-melanocyte-stimulating hormone (α-MSH)-stimulated mouse melanogenic B16F10 cells. Further, to elucidate the molecular mechanism by which ZER suppresses melanin accumulation, we analyzed the expression of melanogenesis-associated transcription factor, microphthalmia-associated transcription factor (MITF), and its target genes, such as tyrosinase , tyrosinase-related protein 1 ( TYRP1 ), and tyrosinase-related protein 2 ( TYRP2 ), in B16F10 cells that are stimulated by α-MSH...
October 13, 2018: International Journal of Molecular Sciences
https://read.qxmd.com/read/30261278/development-of-a-triplex-mtdna-qpcr-assay-to-assess-quantification-degradation-inhibition-and-amplification-target-copy-numbers
#14
Mark F Kavlick
A hybrid absolute/relative qPCR assay which provides information regarding the condition of mitochondrial DNA (mtDNA) in a DNA sample is described. MtDNA concentration (copy number/μL) is determined via absolute quantification using a standard curve of a synthetic duplex DNA previously described (Kavlick et al., 2011). The state of mtDNA degradation is determined via the relative quantification of a mtDNA target found within the 16 s rRNA gene which is 3× longer than that of the short target in the former duplex assay, using the delta, delta Ct (ΔΔCt) method...
September 25, 2018: Mitochondrion
https://read.qxmd.com/read/30258113/perineuronal-nets-in-the-lateral-hypothalamus-area-regulate-cue-induced-reinstatement-of-cocaine-seeking-behavior
#15
Jordan M Blacktop, Barbara A Sorg
We previously reported that a small, circumscribed region of the lateral hypothalamus, the anterior dorsal region (LHAad), stains heavily for PNNs and dense extracellular matrix (PNNs/ECM) with Wisteria floribunda agglutinin (WFA), and critically contributes to the acquisition of cocaine-induced conditioned place preference and cocaine self-administration. Here we tested the role of LHAad PNNs/ECM in cue-induced reinstatement in cocaine self-administering (SA) rats and identified how it is embedded in the circuitry of motivated behavior and drug reward...
September 11, 2018: Neuropsychopharmacology: Official Publication of the American College of Neuropsychopharmacology
https://read.qxmd.com/read/30229956/the-physical-and-chemical-disruption-of-human-hair-after-bleaching-studies-by-transmission-electron-microscopy-and-redox-proteomics
#16
A J Grosvenor, S Deb-Choudhury, P G Middlewood, A Thomas, E Lee, J A Vernon, J L Woods, C Taylor, F I Bell, S Clerens
OBJECTIVE: To understand the structural and chemical effects of cosmetic peroxide bleaching on human hair. METHODS: Human hair was progressively bleached using alkaline peroxide-persulphate treatment. Proteins lost through leaching were examined using amino acid analysis and mass spectrometric sequencing. Fibre damage was assessed using transmission electron microscopy, amino acid analysis and redox proteomics. RESULTS: Protein loss through leaching increased with bleaching severity...
December 2018: International Journal of Cosmetic Science
https://read.qxmd.com/read/30224716/attenuation-of-melanogenesis-by-nymphaea-nouchali-burm-f-flower-extract-through-the-regulation-of-camp-creb-mapks-mitf-and-proteasomal-degradation-of-tyrosinase
#17
Md Badrul Alam, Arif Ahmed, Md Abdul Motin, Sunghwan Kim, Sang-Han Lee
Medicinal plants have been used to treat diseases from time immemorial. We aimed to examine the efficacy of the ethyl acetate fraction of Nymphaea nouchali flower extract (NNFE) against melanogenesis process, and the underlying mechanisms in vitro and in vivo. Paper spray ionisation mass spectroscopy and (+) mode electrospray ionisation revealed the presence of seven flavonoids, two spermidine alkaloids, 3,4,8,9,10-pentahydroxy-dibenzo[b,d]pyran-6-one, and shoyuflavone C in NNFE. NNFE (100 µg/mL) significantly inhibited the monophenolase and diphenolase activities of mushroom tyrosinase at 94...
September 17, 2018: Scientific Reports
https://read.qxmd.com/read/30208522/silencing-of-pmel-attenuates-melanization-via-activating-lysosomes-and-degradation-of-tyrosinase-by-lysosomes
#18
Lijun Sun, Lei Hu, Ping Zhang, Huijin Li, Jingying Sun, Haifang Wang, Xin Xie, Jun Hu
The functionally specialized melanosome is a membrane-enclosed lysosome-related organelle, which coexists with lysosomes in melanocytes. Pre-melanosomal protein (PMEL) initiates pre-melanosome morphogenesis and is the only cell-specific pigment protein required for the formation of fibrils on which melanin is deposited in melanosomes. But the effects of PMEL on melanin synthesis and lysosome activity remain unclear. In the study, PMEL was silenced in human epidermal melanocytes by siRNA transfection. Compared to the non-treated group, melanin content in the transfected cells was greatly reduced...
September 18, 2018: Biochemical and Biophysical Research Communications
https://read.qxmd.com/read/29956303/an-explanation-for-the-mysterious-distribution-of-melanin-in-human-skin-a-rare-example-of-asymmetric-melanin-organelle-distribution-during-mitosis-of-basal-layer-progenitor-keratinocytes
#19
N Joly-Tonetti, J I D Wibawa, M Bell, D J Tobin
BACKGROUND: Melanin is synthesized by melanocytes in the basal layer of the epidermis. When transferred to surrounding keratinocytes melanin is the key ultraviolet radiation-protective biopolymer responsible for skin pigmentation. Most melanin is observable in the proliferative basal layer of the epidermis and only sparsely distributed in the stratifying/differentiating epidermis. The latter has been explained as 'melanin degradation' in suprabasal layers. OBJECTIVES: To re-evaluate the currently accepted basis for melanin distribution in human epidermis and to discover whether this pattern is altered after a regenerative stimulus...
November 2018: British Journal of Dermatology
https://read.qxmd.com/read/29890139/anti-melanogenic-activity-of-schaftoside-in-rhizoma-arisaematis-by-increasing-autophagy-in-b16f1-cells
#20
Pan Soo Kim, Ji Hyun Shin, Doo Sin Jo, Dong Woon Shin, Dong-Hwa Choi, Woo Jung Kim, Kyuhee Park, Jin Kyu Kim, Chul Gue Joo, Jong Suk Lee, Yongmun Choi, Yong Won Shin, Joong Jin Shin, Hong Bae Jeon, Jin-Ho Seo, Dong-Hyung Cho
Skin pigmentation involves multiple processes, including melanin synthesis, transport, and melanosome release. Melanin content determines skin color and protects against UV radiation-induced damage. Autophagy is a cooperative process between autophagosomes and lysosomes that degrades cellular components and organelles. In the present study, B16F1 cells were treated with Rhizoma Arisaematis extract (RA) and assessed for pigmentation and autophagy regulation. RA treatment suppressed the α-MSH-stimulated increase of melanogenesis and down-regulated the expression of tyrosinase and TRP1 proteins in B16F1 cells...
September 3, 2018: Biochemical and Biophysical Research Communications
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