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Manickam Sugumaran, Hanine Barek
Animals synthesize melanin pigments for the coloration of their skin and use it for their protection from harmful solar radiation. Insects use melanins even more ingeniously than mammals and employ them for exoskeletal pigmentation, cuticular hardening, wound healing and innate immune responses. In this review, we discuss the biochemistry of melanogenesis process occurring in higher animals and insects. A special attention is given to number of aspects that are not previously brought to light: (1) the molecular mechanism of dopachrome conversion that leads to the production of two different dihydroxyindoles; (2) the role of catecholamine derivatives other than dopa in melanin production in animals; (3) the critical parts played by various biosynthetic enzymes associated with insect melanogenesis; and (4) the presence of a number of important gaps in both melanogenic and sclerotinogenic pathways...
October 20, 2016: International Journal of Molecular Sciences
Lijun Sun, Jingying Sun, Xueping Huo, Yaping Li, Yuan Li, Xin Xie, Jun Hu
Objective To explore the effect of Toll-like receptor 4 (TLR4) activation on melanogenesis in melanocytes. Methods The primary melanocytes were isolated, cultured and then stimulated by TLR4 agonist lipopolysaccharide (LPS). Firstly, the melanin content changes were detected in melanocytes, and then quantitative real-time PCR and Western blotting were employed to determine the expression levels of pre-melanosomal protein (Pmel17), tyrosinase (TYR) and microphthalmia-associated transcription factor (MITF). Finally, the melanosomes were observed by electron microscopy...
November 2016: Xi Bao Yu Fen Zi Mian Yi Xue za Zhi, Chinese Journal of Cellular and Molecular Immunology
Bruno Fernandes, Teresa Matamá, Diana Guimarães, Andreia Gomes, Artur Cavaco-Paulo
Melanin quantification is reportedly performed by absorption spectroscopy, commonly at 405 nm. Here, we propose the implementation of fluorescence spectroscopy for melanin assessment. In a typical in vitro assay to assess melanin production in response to an external stimulus, absorption spectroscopy clearly overvalues melanin content. This method is also incapable of distinguishing non-melanotic/amelanotic control cells from those that are actually capable of performing melanogenesis. Therefore, fluorescence spectroscopy is the best method for melanin quantification as it proved to be highly specific and accurate, detecting even small variations in the synthesis of melanin...
October 22, 2016: Pigment Cell & Melanoma Research
Rivka Inzelberg, Shira Flash, Eitan Friedman, Esther Azizi
The mechanisms underlying the high prevalence of cutaneous malignant melanoma (CMM) in Parkinson's disease (PD) are unclear, but plausibly involve common pathways. 129Ser-phosphorylated-α-synuclein, a pathological PD hallmark, is abundantly expressed in CMM, but not in normal skin. In inherited PD, PARK genes harbor germline mutations; the same genes are somatically mutated in CMM, or their encoded proteins involved in melanomagenesis. Conversely, genes associated with CMM, affect PD risk. PD/CMM targeted cells share the neural crest origin and melanogenesis capability...
October 19, 2016: Annals of Neurology
Yoshiaki Manse, Kiyofumi Ninomiya, Ryosuke Nishi, Iyori Kamei, Yushi Katsuyama, Takahito Imagawa, Saowanee Chaipech, Osamu Muraoka, Toshio Morikawa
An aqueous acetone extract from the fruit of Alpinia galanga (Zingiberaceae) demonstrated inhibitory effects on melanogenesis in theophylline-stimulated murine B16 melanoma 4A5 cells (IC50=7.3μg/mL). Through bioassay-guided separation of the extract, a new 7-O-9'-linked neolignan, named galanganol D diacetate (1), was isolated along with 16 known compounds including 14 phenylpropanoids (2-15). The structure of 1, including its absolute stereochemistry in the C-7 position, was elucidated by means of extensive NMR analysis and total synthesis...
October 6, 2016: Bioorganic & Medicinal Chemistry
Anna V Motorina, Nadezhda V Palkina, Anna V Komina, Tatiana G Ruksha, Ivan P Artyukhov, Vasily V Kozlov
The melanocortin 1 receptor is a Gs protein-coupled receptor implicated in melanogenesis regulation. The receptor gene is highly polymorphic, which accounts for the association of several of its single-nucleotide polymorphisms (SNPs) with an increased risk of melanoma. The present study aimed to evaluate the distribution of melanocortin 1 receptor gene variants R151C, R160W, and D294H within the Russian population of Eastern Siberia and its association with melanoma development. Melanoma patients (n=95) admitted to Krasnoyarsk Territorial Oncological Center and healthy controls (n=334) were enrolled in the study...
October 13, 2016: European Journal of Cancer Prevention
Pham Thi Be Tu, Binh Cao Quan Nguyen, Shinkichi Tawata, Cheong-Yong Yun, Eung Gook Kim, Hiroshi Maruta
We previously demonstrated that the oncogenic kinase PAK4, which both melanomas and normal melanocytes express at a very high level, is essential for their melanogenesis. In the present study, using the highly sensitive "Macaroni-Western" (IP-ATP-Glo) kinase assay, we investigated the melanogenic potential of another oncogenic kinase PAK1, which melanoma (B16F10) cells express only at a very minute level. After transfecting melanoma cells with PAK1-shRNA for silencing PAK1 gene, melanin content, tyrosinase activity, and kinase activity of PAK1 were compared between the wild-type and transfectants...
October 17, 2016: Drug Discoveries & Therapeutics
P Urban, M Rabajdová, B Veliká, I Špaková, B Bolerázska, M Mareková
BACKGROUND: Malignant melanoma is one of the most aggressive types of cancers. Melanoma is derived from pigment-producing cells, melanocytes, which are characterized by a specific survival mechanism. Microphthalmia-associated transcription factor (MITF-M) plays a role in the metabolism of melanoma and is involved in the regulation of the expression of multiple genes mediating processes such as melanogenesis, proliferation, differentiation, and melanocyte survival. The expression of this transcription factor in melanocytes is activated by several signaling pathways, and reduced expression or function of MITF-M can cause the dysregulation of anti-apoptotic mechanisms...
2016: Klinická Onkologie: Casopis Ceské a Slovenské Onkologické Spolecnosti
Chen Tianzhi, Zhao Bingling, Liu Yu, Zhao Yuanyuan, Wang Haidong, Fan Ruiwen, Wang Pengchao, Dong Changsheng
G-protein coupled receptor143 (GPR143) plays an important role in melanogenesis. In this study, we investigated the expression pattern and localization of GPR143 in skin of sheep with different coat colors and explored the correlation between GPR143 gene and coat color. The mRNA level and protein level of GPR143 in skin of sheep with different coat colors were detected by qRT-PCR and immunoblotting separately while the localization of GPR143 in sheep skin was detected by immunofluorescence assay following optical density analysis...
July 20, 2016: Yi Chuan, Hereditas
Mayuree Kanlayavattanakul, Nattaya Lourith, Puxvadee Chaikul
ETHNOPHARMACOLOGICAL RELEVANCE: While rice is one of the most important global staple food sources its extracts have found many uses as the bases of herbal remedies. Rice extracts contain high levels of phenolic compounds which are known to be bioactive, some of which show cutaneous benefits and activity towards skin disorders. This study highlights an assessment of the cellular activity and clinical efficacy of rice panicle extract, providing necessary information relevant to the development of new cosmetic products...
October 6, 2016: Journal of Ethnopharmacology
Ki Won Lee, Hyung Won Ryu, Sang-Seok Oh, Soojong Park, Hamadi Madhi, Jiyun Yoo, Ki-Hun Park, Kwang Dong Kim
Melanogenesis is a key pathway for the regulation of skin pigmentation and the development of skin-lightening/whitening drugs or cosmetics. In this study, we found that β-mangostin from seedcases of Garcinia mangostana inhibited α-melanocyte-stimulating hormone (α-MSH)-mediated melanogenesis in B16F10 melanoma cells and a three-dimensional human skin model. β-Mangostin significantly inhibited the protein level of tyrosinase induced by α-MSH in UPS (ubiquitin proteasome system)-independent and lysosome-dependent manner...
October 7, 2016: Experimental Dermatology
Chao Niu, Guang Xian Pang, Gen Li, Jun Dou, Li Fei Nie, Helimay Himit, Madina Kabas, Haji Akber Aisa
Furocoumarins, isolated from Psoralen corylifolia L., were found to be the most effective drug in the treatment of vitiligo nowadays. Twenty-five furocoumarin derivatives were thus designed and synthesized in order to improve the melanogenesis in B16 cells for the first time. Among them, twenty-three compounds were more potent than the positive control (8-MOP), the commonly used drug for vitiligo in clinic. Noticeably, compounds 6m (350.5%) and 6p (313.1%) based on the scaffold of 6k (2H-benzofuro[2,3-h]chromen-2-one) were nearly 3-fold stronger than 8-MOP (114...
September 23, 2016: Bioorganic & Medicinal Chemistry
Joo Hyun Nam, Dong-Ung Lee
BACKGROUND: Ultraviolet radiation exposure is the most important cause of extrinsic skin aging (photoaging), which causes skin wrinkling and hyperpigmentation. Although many factors are involved in the photoaging process, calcium release-activated calcium channel protein 1 (ORAI1) has been reported to be involved in UV-induced melanogenesis. OBJECTIVE: The aim of the present study was to find inhibitory effects of the extract of Foeniculum vulgare (fennel) fruits on ORAI1 ion channels and UV-induced melanogenesis in melanoma cells and to identify its active constituents...
September 28, 2016: Journal of Dermatological Science
Chenyao Wang, Lu Zhao, Qian Su, Xiaoyu Fan, Ying Wang, Shunqiang Gao, Huafei Wang, Huaiyong Chen, Chi Bun Chan, Zhixue Liu
Microphthalmia-associated transcription factor (MITF) plays a crucial role in the melanogenesis and proliferation of melanocytes that is dependent on its abundance and modification. Here, we report that epidermal growth factor (EGF) induces senescence and cyclin-dependent kinase inhibitor 1A (CDKN1A) expression that is related to MITF. We found that MITF could bind TP53 to regulate CDKN1A. Furthermore, the interaction between MITF and TP53 is dependent on AKT activity. We found that AKT phosphorylates MITF at S510...
October 1, 2016: International Journal of Biochemistry & Cell Biology
Kamal Uddin Zaidi, Sharique A Ali, Ayesha S Ali
In mammalian melanocytes, melanosome is a highly specialized organelle where melanin is synthesized. Melanin synthesis is controlled by tyrosinase, the vital enzyme in melanogenic pathway. The present investigation is based on an effect of purified mushroom tyrosinase of Agaricus bisporus on B16F10 melanocytes for the melanin production via blocking pigment cell machinery. Using B16F10 melanocytes showed that the stimulation of melanogenesis by purified tyrosinase is due to increased tyrosinase absorption. Cellular tyrosinase activity and melanin content in B16F10 melanocytes were increased by purified tyrosinase in a dose-dependent manner...
2016: Biotechnology Research International
Chang Taek Oh, Tae-Rin Kwon, Eun Ja Choi, Soon Re Kim, Joon Seok, Seog Kyun Mun, Kwang Ho Yoo, Yeon Shik Choi, Sun Young Choi, Beom Joon Kim
BACKGROUND: Skin hyperpigmentary disorders including postinflammatory hyperpigmentation, melasma, solar lentigines, and conditions like freckles are common. The light-emitting diodes (LEDs) are the latest category of nonthermal and noninvasive phototherapy to be considered in skin pigmentation disorder treatment. PURPOSE: The purpose of this study was to investigate the effects of 660-nm LED on inhibition of melanogenesis. We investigated whether a 660-nm LED affected melanin synthesis in in vitro and in vivo models, and we explored the mechanisms involved...
October 1, 2016: Photodermatology, Photoimmunology & Photomedicine
Haruyoshi Seino, Yukari Arai, Norio Nagao, Noriyasu Ozawa, Kazuhiko Hamada
Partially myristoylated chitosan pyrrolidone carboxylate (PMCP) is a cationic amphiphilic chitosan derivative. Glabridin (Glab) from licorice root extracts is a hydrophobic antimelanogenic agent. Here we assessed the effects of cationic Glab-containing polymeric micelles derived from PMCP (Glab/PMCP-PM) on the ability of Glab to penetrate the skin and inhibit melanogenesis using a human skin model. The amount of Glab absorbed 24 h after the application of Glab/PMCP-PM was approximately four times higher than that of conventional oil-in-water micelles (control) prepared using Tween 60...
2016: PloS One
Thanigaimalai Pillaiyar, Manoj Manickam, Sang-Hun Jung
Melanin, primarily responsible in humans for hair, eye and skin pigmentation, is produced by melanocytes through a process called melanogenesis. However, the abnormal accumulation of melanin causes dermatological problems such as café-au-lait macules ephelides (freckles), solar lentigo (age spots) and melasma, as well as cancer and vitiligo. Hence the regulation of melanogenesis is very important for treating hyperpigmentary disorders. Numerous antimelanogenic agents that target tyrosinase activity and/or stability, melanosome maturation, transfer and trafficking, or melanogenesis-related signaling pathways have been developed...
September 28, 2016: Drug Discovery Today
Tomohisa Hirobe, Tatako Shibata, Kiyoshi Sato
BACKGROUND: Oxidative stress caused by hydrogen peroxide (H2O2) elicits harmful effects on human melanocytes such as DNA damage and cell death. On the contrary, H2O2 is known to possess beneficial effects on melanocytes. However, mechanisms of the beneficial effects of H2O2 on melanocytes have not been fully understood, especially the indirect effects on melanocyte proliferation and differentiation from cells constituting surrounding tissue environment such as fibroblasts. OBJECTIVE: The aim of this study was to clarify whether H2O2-treated human fibroblasts affect the proliferation and differentiation of human melanocytes using serum-free co-culture system...
September 5, 2016: Journal of Dermatological Science
Tianzhi Chen, Haidong Wang, Yu Liu, Bingling Zhao, Yuanyuan Zhao, Ruiwen Fan, Pengchao Wang, Changsheng Dong
To investigate whether ocular albinism type 1 (OA1) is differentially expressed in the skin of mice with different coat colors and to determine its correlation with coat color establishment in mouse, the expression patterns and tissue distribution characterization of OA1 in the skin of mice with different coat colors were qualitatively and quantitatively analyzed by real-time quantitative PCR (qRT-PCR), immunofluorescence staining and Western blot. The qRT-PCR analysis revealed that OA1 mRNA was expressed in all mice skin samples tested, with the highest expression level in brown skin, a moderate expression level in black skin and the lowest expression level in gray skin...
2016: International Journal of Molecular Sciences
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