A5010983774- melanin and skin pigmentation
- Biochemical Analysis and Sensing Techniques
- Skin Protection and Aging
- Olfactory and Sensory Function Studies
- Animal Behavior and Reproduction
- Phytochemicals and Antioxidant Activities
- Neurobiology and Insect Physiology Research
- Plant and animal studies
- Dyeing and Modifying Textile Fibers
- RNA regulation and disease
- Cutaneous Melanoma Detection and Management
- Immunotherapy and Immune Responses
- Melanoma and MAPK Pathways
- Parkinson's Disease Mechanisms and Treatments
- Plant Toxicity and Pharmacological Properties
- Antioxidant Activity and Oxidative Stress
- Natural product bioactivities and synthesis
- Identification and Quantification in Food
- Dye analysis and toxicity
- Mast cells and histamine
- Polyamine Metabolism and Applications
- Regulation of Appetite and Obesity
- Genomics, phytochemicals, and oxidative stress
- Bioactive Compounds and Antitumor Agents
- Cell Adhesion Molecules Research
Fujita Health University
2016-2025
Fujita Health University Hospital
2013-2025
Toshiba (Japan)
2024
Omuta hospital
2024
Nippon Medical School
2022
University of California, Merced
2018
RMIT University
2006-2015
Stelic Institute (Japan)
2013
Kagoshima University
2011
Osaka University
2005-2007
Okadaic acid is a polyether compound of C38 fatty acid, isolated from black sponge, Halichondria okadai. Previous studies showed that okadaic skin irritant and induces ornithine decarboxylase (OrnDCase; 3-hydroxyl-L-glutamate 1-carboxy-lyase, EC 4.1.1.17) in mouse 4 hr after its application to the skin. This induction was strongly inhibited by pretreatment with 13-cis-retinoic acid. A two-stage carcinogenesis experiment initiated single 100 micrograms 7,12-dimethylbenz[a]anthracene (DMBA)...
The dark side of melanin exposed Sun worshippers may have more to worry about than the DNA damage that occurs while they're relaxing on beach. It seems photoproducts responsible for cancer-causing mutations in skin cells continue be generated hours after sunlight exposure. Premi et al. find a key mediator this delayed is melanin, pigment thought protect against cancer (see Perspective by Taylor). They propose “chemiexcitation” model which reactive oxygen and nitrogen species induced...
Parkinson's disease (PD) is the most common movement disorder characterized by dopaminergic dysfunction and degeneration. The cause of PD cases unknown, although postmortem studies have implicated involvement oxidative stress. identification familial PD-associated genes offers opportunity to study mechanisms pathogenesis in model organisms. Here, we show that DJ-1A, a Drosophila homologue gene DJ-1, plays an essential role stress response neuronal maintenance. Inhibition DJ-1A function...
Eumelanin and pheomelanin in tissue samples can be specifically measured as the markers pyrrole-2,3,5-tricarboxylic acid (PTCA) 4-amino-3-hydroxyphenylalanine after acidic permanganate oxidation hydroiodic hydrolysis, respectively. Those degradation methods, although widely applied, are not easily performed most laboratories. To overcome this difficulty, we developed alkaline H(2)O(2) 1 M K(2)CO(3) that produces, addition to eumelanin marker PTCA, thiazole-2,4,5-tricarboxylic (TTCA)...
How natural selection affects mouse coat color Evolution, at its core, involves changes in the frequency of alleles subject to selection. But identifying target can be difficult. Barrett et al. investigated how allele frequencies affecting pigmentation change over time (see Perspective by Pelletier). Wild-caught mice ( Peromyscus maniculatus ) were exposed avian predators against naturally occurring dark or light backgrounds. Natural yielded shifts coloration owing genetic variants Agouti...
DNA damage induced by UV radiation is a critical event in skin photocarcinogenesis. However, the role of racial/ethnic origin determining individual sensitivity remains unclear. In this study, we examined relationships between melanin content and exposure situ normal human different groups, phototypes, sensitivities. The minimal erythema dose (MED) was established for each subject exposed to UVA/UVB radiation, biopsied before as well 7 min, 1 day, wk after exposure. There great variation...
Neuronal pigments of melanic type were identified in the putamen, cortex, cerebellum, and other major regions human brain. These consist granules 30 nm size, contained organelles together with lipid droplets, they accumulate aging, reaching concentrations as high 1.5–2.6 μg/mg tissue brain regions. pigments, which we term neuromelanins, contain melanic, lipid, peptide components. The component is aromatic structure, contains a stable free radical, synthesized from precursor molecule...
Reductive hydrolysis of pheomelanin with hydriodic acid (HI) gives two aminohydroxyphenylalanine isomers, 4‐amino‐3‐hydroxyphenylalanine (`specific AHP') and 3‐amino‐4‐hydroxyphenylalanine (3‐aminotyrosine, AT), which derive from the oxidative polymerization 5‐ S ‐cysteinyldopa, 2‐ respectively. Since we first introduced this analytical method, combined amount AHP AT (`total has been extensively used as a marker pheomelanin. However, one problem using total is that background levels...
Mammalian melanins exist in two chemically distinct forms: the brown to black eumelanins and yellow reddish‐brown pheomelanins. They can be quantified by HPLC analysis of pyrrole‐2,3,5‐tricarboxylic acid (PTCA) aminohydroxyphenylalanine (AHP). We recently developed a spectrophotometric method for assaying total amount eu‐ pheomelanins dissolving Soluene‐350 plus water. In this study, we examined whether absorbance at 500 nm (A ) solution reflects obtained methods, ratio absorbances between...
In mammals, >100 genes regulate pigmentation by means of a wide variety developmental, cellular, and enzymatic mechanisms. Nevertheless, that directly pheomelanin production have not been described. Here, we demonstrate the subtle gray ( sut ) mouse mutant arose mutation in Slc7a11 gene, encoding plasma membrane cystine/glutamate exchanger xCT [Kanai, Y. & Endou, H. (2001) Curr. Drug Metab. 2, 339-354]. A resulting low rate extracellular cystine transport into melanocytes reduces...
Cutaneous pigmentation is determined by the amounts of eumelanin and pheomelanin synthesized epidermal melanocytes known to protect against sun-induced DNA damage. The synthesis stimulated binding α-melanotropin (α-melanocyte-stimulating hormone)to functional melanocortin 1 receptor (MC1R) expressed on melanocytes. human MC1R gene highly polymorphic certain allelic variants are associated with red hair phenotype, melanoma non-melanoma skin cancer. importance in determining cancer risk led us...
Melanins are difficult to characterize because of their intractable chemical properties, the heterogeneity in structural features, and lack methods split melanin polymers into monomer units. To overcome this difficulty, we developed a rapid sensitive method for quantitatively analyzing eumelanin pheomelanin biological samples that is based on formation pyrrole‐2,3,5‐tricarboxylic acid and/or aminohydroxyphenylalanine followed by HPLC determination. The has been applied study melanogenesis....