1
|
D’Arino A, Caputo S, Eibenschutz L, Piemonte P, Buccini P, Frascione P, Bellei B. Skin Cancer Microenvironment: What We Can Learn from Skin Aging? Int J Mol Sci 2023; 24:14043. [PMID: 37762344 PMCID: PMC10531546 DOI: 10.3390/ijms241814043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2023] [Revised: 08/30/2023] [Accepted: 09/09/2023] [Indexed: 09/29/2023] Open
Abstract
Aging is a natural intrinsic process associated with the loss of fibrous tissue, a slower cell turnover, and a reduction in immune system competence. In the skin, the continuous exposition of environmental factors superimposes extrinsic damage, mainly due to ultraviolet radiation causing photoaging. Although not usually considered a pathogenic event, photoaging affects cutaneous biology, increasing the risk of skin carcinogenesis. At the cellular level, aging is typified by the rise of senescence cells a condition characterized by reduced or absent capacity to proliferate and aberrant hyper-secretory activity. Senescence has a double-edged sword in cancer biology given that senescence prevents the uncontrolled proliferation of damaged cells and favors their clearance by paracrine secretion. Nevertheless, the cumulative insults and the poor clearance of injured cells in the elderly increase cancer incidence. However, there are not conclusive data proving that aged skin represents a permissive milieu for tumor onset. On the other hand, tumor cells are capable of activating resident fibroblasts onto a pro-tumorigenic phenotype resembling those of senescent fibroblasts suggesting that aged fibroblasts might facilitate cancer progression. This review discusses changes that occur during aging that can prime neoplasm or increase the aggressiveness of melanoma and non-melanoma skin cancer.
Collapse
Affiliation(s)
- Andrea D’Arino
- Oncologic and Preventative Dermatology, San Gallicano Dermatological Institute, Istituto di Ricovero e Cura a Carattere Scientifico IRCCS, 00141 Rome, Italy
| | - Silvia Caputo
- Laboratory of Cutaneous Physiopathology and Integrated Center of Metabolomics Research, San Gallicano Dermatological Institute, Istituto di Ricovero e Cura a Carattere Scientifico IRCCS, 00141 Rome, Italy
| | - Laura Eibenschutz
- Oncologic and Preventative Dermatology, San Gallicano Dermatological Institute, Istituto di Ricovero e Cura a Carattere Scientifico IRCCS, 00141 Rome, Italy
| | - Paolo Piemonte
- Oncologic and Preventative Dermatology, San Gallicano Dermatological Institute, Istituto di Ricovero e Cura a Carattere Scientifico IRCCS, 00141 Rome, Italy
| | - Pierluigi Buccini
- Oncologic and Preventative Dermatology, San Gallicano Dermatological Institute, Istituto di Ricovero e Cura a Carattere Scientifico IRCCS, 00141 Rome, Italy
| | - Pasquale Frascione
- Oncologic and Preventative Dermatology, San Gallicano Dermatological Institute, Istituto di Ricovero e Cura a Carattere Scientifico IRCCS, 00141 Rome, Italy
| | - Barbara Bellei
- Laboratory of Cutaneous Physiopathology and Integrated Center of Metabolomics Research, San Gallicano Dermatological Institute, Istituto di Ricovero e Cura a Carattere Scientifico IRCCS, 00141 Rome, Italy
| |
Collapse
|
2
|
Chaiprasongsuk A, Panich U. Role of Phytochemicals in Skin Photoprotection via Regulation of Nrf2. Front Pharmacol 2022; 13:823881. [PMID: 35645796 PMCID: PMC9133606 DOI: 10.3389/fphar.2022.823881] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2021] [Accepted: 04/11/2022] [Indexed: 12/13/2022] Open
Abstract
Ethnopharmacological studies have become increasingly valuable in the development of botanical products and their bioactive phytochemicals as novel and effective preventive and therapeutic strategies for various diseases including skin photoaging and photodamage-related skin problems including abnormal pigmentation and inflammation. Exploring the roles of phytochemicals in mitigating ultraviolet radiation (UVR)-induced skin damage is thus of importance to offer insights into medicinal and ethnopharmacological potential for development of novel and effective photoprotective agents. UVR plays a role in the skin premature aging (or photoaging) or impaired skin integrity and function through triggering various biological responses of skin cells including apoptosis, oxidative stress, DNA damage and inflammation. In addition, melanin produced by epidermal melanocytes play a protective role against UVR-induced skin damage and therefore hyperpigmentation mediated by UV irradiation could reflect a sign of defensive response of the skin to stress. However, alteration in melanin synthesis may be implicated in skin damage, particularly in individuals with fair skin. Oxidative stress induced by UVR contributes to the process of skin aging and inflammation through the activation of related signaling pathways such as the mitogen-activated protein kinase (MAPK)/activator protein-1 (AP-1), the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt), the nuclear factor kappa B (NF-κB) and the signal transducer and activator of transcription (STAT) in epidermal keratinocytes and dermal fibroblasts. ROS formation induced by UVR also plays a role in regulation of melanogenesis in melanocytes via modulating MAPK, PI3K/Akt and the melanocortin 1 receptor (MC1R)-microphthalmia-associated transcription factor (MITF) signaling cascades. Additionally, nuclear factor erythroid 2-related factor 2 (Nrf2)-regulated antioxidant defenses can affect the major signaling pathways involved in regulation of photoaging, inflammation associated with skin barrier dysfunction and melanogenesis. This review thus highlights the roles of phytochemicals potentially acting as Nrf2 inducers in improving photoaging, inflammation and hyperpigmentation via regulation of cellular homeostasis involved in skin integrity and function. Taken together, understanding the role of phytochemicals targeting Nrf2 in photoprotection could provide an insight into potential development of natural products as a promising strategy to delay skin photoaging and improve skin conditions.
Collapse
Affiliation(s)
| | - Uraiwan Panich
- Department of Pharmacology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
- *Correspondence: Uraiwan Panich,
| |
Collapse
|
3
|
Pheomelanin Effect on UVB Radiation-Induced Oxidation/Nitration of l-Tyrosine. Int J Mol Sci 2021; 23:ijms23010267. [PMID: 35008693 PMCID: PMC8745751 DOI: 10.3390/ijms23010267] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2021] [Revised: 12/20/2021] [Accepted: 12/23/2021] [Indexed: 11/25/2022] Open
Abstract
Pheomelanin is a natural yellow-reddish sulfur-containing pigment derived from tyrosinase-catalyzed oxidation of tyrosine in presence of cysteine. Generally, the formation of melanin pigments is a protective response against the damaging effects of UV radiation in skin. However, pheomelanin, like other photosensitizing substances, can trigger, following exposure to UV radiation, photochemical reactions capable of modifying and damaging cellular components. The photoproperties of this natural pigment have been studied by analyzing pheomelanin effect on oxidation/nitration of tyrosine induced by UVB radiation at different pH values and in presence of iron ions. Photoproperties of pheomelanin can be modulated by various experimental conditions, ranging from the photoprotection to the triggering of potentially damaging photochemical reactions. The study of the photomodification of l-Tyrosine in the presence of the natural pigment pheomelanin has a special relevance, since this tyrosine oxidation/nitration pathway can potentially occur in vivo in tissues exposed to sunlight and play a role in the mechanisms of tissue damage induced by UV radiation.
Collapse
|
4
|
Shankar N, Guimarães AO, Napoli E, Giulivi C. Forensic determination of hair deposition time in crime scenes using electron paramagnetic resonance. J Forensic Sci 2020; 66:72-82. [PMID: 32986869 DOI: 10.1111/1556-4029.14570] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Revised: 08/06/2020] [Accepted: 08/18/2020] [Indexed: 11/28/2022]
Abstract
Several types of biological samples, including hair strands, are found at crime scenes. Apart from the identification of the value and the contributor of the probative evidence, it is important to prove that the time of shedding of hair belonging to a suspect or victim matches the crime window. To this end, to estimate the ex vivo aging of hair, we evaluated time-dependent changes in melanin-derived free radicals in blond, brown, and black hairs by using electron paramagnetic resonance spectroscopy (EPR). Hair strands aged under controlled conditions (humidity 40%, temperature 20-22°C, indirect light, with 12/12 hour of light/darkness cycles) showed a time-dependent decay of melanin-derived radicals. The half-life of eumelanin-derived radicals in hair under our experimental settings was estimated at 22 ± 2 days whereas that of pheomelanin was about 2 days suggesting better stabilization of unpaired electrons by eumelanin. Taken together, this study provides a reference for future forensic studies on determination of degradation of shed hair in a crime scene by following eumelanin radicals by utilizing the non-invasive, non-destructive, and highly specific EPR technique.
Collapse
Affiliation(s)
- Nikhita Shankar
- Department of Molecular Biosciences, School of Veterinary Medicine, University of California Davis, Davis, CA, USA
| | - André O Guimarães
- Department of Molecular Biosciences, School of Veterinary Medicine, University of California Davis, Davis, CA, USA.,Laboratório de Ciências Físicas, Universidade Estadual do Norte Fluminense, Campos dos Goytacazes, RJ, Brazil
| | - Eleonora Napoli
- Department of Molecular Biosciences, School of Veterinary Medicine, University of California Davis, Davis, CA, USA
| | - Cecilia Giulivi
- Department of Molecular Biosciences, School of Veterinary Medicine, University of California Davis, Davis, CA, USA.,MIND Institute, University of California Davis Medical Center, Sacramento, CA, USA
| |
Collapse
|
5
|
Werren EA, Garcia O, Bigham AW. Identifying adaptive alleles in the human genome: from selection mapping to functional validation. Hum Genet 2020; 140:241-276. [PMID: 32728809 DOI: 10.1007/s00439-020-02206-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2020] [Accepted: 07/07/2020] [Indexed: 12/19/2022]
Abstract
The suite of phenotypic diversity across geographically distributed human populations is the outcome of genetic drift, gene flow, and natural selection throughout human evolution. Human genetic variation underlying local biological adaptations to selective pressures is incompletely characterized. With the emergence of population genetics modeling of large-scale genomic data derived from diverse populations, scientists are able to map signatures of natural selection in the genome in a process known as selection mapping. Inferred selection signals further can be used to identify candidate functional alleles that underlie putative adaptive phenotypes. Phenotypic association, fine mapping, and functional experiments facilitate the identification of candidate adaptive alleles. Functional investigation of candidate adaptive variation using novel techniques in molecular biology is slowly beginning to unravel how selection signals translate to changes in biology that underlie the phenotypic spectrum of our species. In addition to informing evolutionary hypotheses of adaptation, the discovery and functional annotation of adaptive alleles also may be of clinical significance. While selection mapping efforts in non-European populations are growing, there remains a stark under-representation of diverse human populations in current public genomic databases, of both clinical and non-clinical cohorts. This lack of inclusion limits the study of human biological variation. Identifying and functionally validating candidate adaptive alleles in more global populations is necessary for understanding basic human biology and human disease.
Collapse
Affiliation(s)
- Elizabeth A Werren
- Department of Human Genetics, The University of Michigan, Ann Arbor, MI, USA
- Department of Anthropology, The University of Michigan, Ann Arbor, MI, USA
| | - Obed Garcia
- Department of Anthropology, The University of Michigan, Ann Arbor, MI, USA
| | - Abigail W Bigham
- Department of Anthropology, University of California Los Angeles, 341 Haines Hall, Los Angeles, CA, 90095, USA.
| |
Collapse
|
6
|
Cecchi T, Pezzella A, Di Mauro E, Cestola S, Ginsburg D, Luzi M, Rigucci A, Santato C. On the antioxidant activity of eumelanin biopigments: a quantitative comparison between free radical scavenging and redox properties. Nat Prod Res 2019; 34:2465-2473. [DOI: 10.1080/14786419.2018.1542391] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Affiliation(s)
| | - Alessandro Pezzella
- Dipartimento di Scienze Chimiche, Universita` di Napoli Federico II, Napoli, Italy
| | - Eduardo Di Mauro
- Department of Engineering Physics, Polytechnique Montreal, Montreal, Quebec, Canada
| | | | | | | | | | - Clara Santato
- Department of Engineering Physics, Polytechnique Montreal, Montreal, Quebec, Canada
| |
Collapse
|
7
|
Lawrence KP, Douki T, Sarkany RPE, Acker S, Herzog B, Young AR. The UV/Visible Radiation Boundary Region (385-405 nm) Damages Skin Cells and Induces "dark" Cyclobutane Pyrimidine Dimers in Human Skin in vivo. Sci Rep 2018; 8:12722. [PMID: 30143684 PMCID: PMC6109054 DOI: 10.1038/s41598-018-30738-6] [Citation(s) in RCA: 70] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2018] [Accepted: 08/03/2018] [Indexed: 12/14/2022] Open
Abstract
The adverse effects of terrestrial solar ultraviolet radiation (UVR) (~295–400 nm) on the skin are well documented, especially in the UVB region (~295–320 nm). The effects of very long-wave UVA (>380 nm) and visible radiation (≥400 nm) are much less known. Sunscreens have been beneficial in inhibiting a wide range of photodamage, however most formulations provide very little protection in the long wave UVA region (380–400 nm) and almost none from shortwave visible wavelengths (400–420 nm). We demonstrate photodamage in this region for a number of different endpoints including cell viability, DNA damage (delayed cyclobutane pyrimidine dimers), differential gene expression (for genes associated with inflammation, oxidative stress and photoageing) and induction of oxidizing species in vitro in HaCaT keratinocytes and in vivo in human volunteers. This work has implications for phototherapy and photoprotection.
Collapse
Affiliation(s)
- Karl P Lawrence
- St. John's Institute of Dermatology, King's College London, Guy's Hospital, London, SE1 9RT, UK.
| | - Thierry Douki
- University Grenoble Alpes, CEA, CNRS, INAC-SyMMES/CIBEST, 38000, Grenoble, France
| | - Robert P E Sarkany
- St. John's Institute of Dermatology, King's College London, Guy's Hospital, London, SE1 9RT, UK
| | | | - Bernd Herzog
- BASF Grenzach GmbH, Grenzach-Whylen, 79639, Germany
| | - Antony R Young
- St. John's Institute of Dermatology, King's College London, Guy's Hospital, London, SE1 9RT, UK.
| |
Collapse
|
8
|
Shanuja SK, Iswarya S, Gnanamani A. Marine fungal DHICA as a UVB protectant: Assessment under in vitro and in vivo conditions. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2018; 179:139-148. [PMID: 29367149 DOI: 10.1016/j.jphotobiol.2018.01.010] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/24/2017] [Revised: 01/10/2018] [Accepted: 01/12/2018] [Indexed: 12/24/2022]
Abstract
The present study explores UVB protective role of a melanin precursor namely DHICA (5,6- Dihydroxyindole-2-carboxylic acid) expressed by the marine imperfect fungus Aspergillus nidulans. In brief, A. nidulans grown in a modified growth medium for the period of 5 days at 25 °C under shaking conditions and the extracellular medium free from fungal biomass used for the extraction of DHICA. The extracted DHICA further exposed to partial purification and subjected to UVB protection studies using HaCaT cells and Balb/c mice independently. DHICA obtained in the present study found soluble in water. Experiments on HaCaT cell compatibility revealed nil cell death up to 500 μM concentration of DHICA. UVB protection studies under in vitro conditions emphasizes DHICA significantly protect HaCaT cells from UVB exposure by quenching the generated ROS, reducing cell apoptosis, maintain the cellular integrity and sequentially down regulating the LPO (Lipid peroxidation) and up-regulating the antioxidant enzyme (SOD (Superoxide Dismutase), Catalase, GPx (Glutathione peroxidase)) respectively. Further, experiments on cell cycle arrest analysis, gelatin zymography, and western blot analysis on COX-2 and TNF-alpha, IHC (Immunohistochemistry) on apoptotic markers (Bax, Bcl2) substantiate the protective role of DHICA. Furthermore, in vivo studies on BALB/c mice carried out and compared with the sunscreen cream with sun protective factor (SPF) of 20. Analysis of skin sections of experimental samples revealed that an appreciable reduction in the epidermal thickness of the skin samples of mice pre-exposed to DHICA followed by UVB exposure compared to UVB exposure alone. RT-PCR results on various inflammatory apoptotic markers also suggested that DHICA has UVB protective potential. The observations made in the present study explore the possible application of DHICA alone as a sun-protective agent for skin care.
Collapse
Affiliation(s)
- S K Shanuja
- Microbiology Division, CSIR-CLRI, Adyar, Chennai 20, India
| | - S Iswarya
- Microbiology Division, CSIR-CLRI, Adyar, Chennai 20, India
| | - A Gnanamani
- Microbiology Division, CSIR-CLRI, Adyar, Chennai 20, India.
| |
Collapse
|
9
|
Scognamiglio F, Travan A, Turco G, Borgogna M, Marsich E, Pasqua M, Paoletti S, Donati I. Adhesive coatings based on melanin-like nanoparticles for surgical membranes. Colloids Surf B Biointerfaces 2017; 155:553-559. [PMID: 28499217 DOI: 10.1016/j.colsurfb.2017.04.057] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2016] [Revised: 03/24/2017] [Accepted: 04/28/2017] [Indexed: 02/06/2023]
Abstract
Adhesive coatings for implantable biomaterials can be designed to prevent material displacement from the site of implant. In this paper, a strategy based on the use of melanin-like nanoparticles (MNPs) for the development of adhesive coatings for polysaccharidic membranes was devised. MNPs were synthesized in vitro and characterized in terms of dimensions and surface potential, as a function of pH and ionic strength. The in vitro biocompatibility of MNPs was investigated on fibroblast cells, while the antimicrobial properties of MNPs in suspension were evaluated on E. coli and S. aureus cultures. The manufacturing of the adhesive coatings was carried out by spreading MNPs over the surface of polysaccharidic membranes; the adhesive properties of the nano-engineered coating to the target tissue (intestinal serosa) were studied in simulated physiological conditions. Overall, this study opens for novel approaches in the design of naturally inspired nanostructured adhesive systems.
Collapse
Affiliation(s)
- Francesca Scognamiglio
- Department of Life Sciences, University of Trieste, Via Licio Giorgieri 5, I-34127, Trieste, Italy.
| | - Andrea Travan
- Department of Life Sciences, University of Trieste, Via Licio Giorgieri 5, I-34127, Trieste, Italy
| | - Gianluca Turco
- Department of Medical, Surgical and Health Sciences, University of Trieste, Piazza dell'Ospitale 1, I-34129 Trieste, Italy
| | - Massimiliano Borgogna
- Department of Life Sciences, University of Trieste, Via Licio Giorgieri 5, I-34127, Trieste, Italy
| | - Eleonora Marsich
- Department of Medical, Surgical and Health Sciences, University of Trieste, Piazza dell'Ospitale 1, I-34129 Trieste, Italy
| | - Mattia Pasqua
- Department of Life Sciences, University of Trieste, Via Licio Giorgieri 5, I-34127, Trieste, Italy
| | - Sergio Paoletti
- Department of Life Sciences, University of Trieste, Via Licio Giorgieri 5, I-34127, Trieste, Italy
| | - Ivan Donati
- Department of Life Sciences, University of Trieste, Via Licio Giorgieri 5, I-34127, Trieste, Italy
| |
Collapse
|
10
|
Sponge-Associated Bacteria Produce Non-cytotoxic Melanin Which Protects Animal Cells from Photo-Toxicity. Appl Biochem Biotechnol 2017; 183:396-411. [DOI: 10.1007/s12010-017-2453-0] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2016] [Accepted: 03/06/2017] [Indexed: 02/05/2023]
|
11
|
Matsunaka H, Yamamoto Y, Furukawa F. Non-invasive quantification of melanin in the stratum corneum: a novel indicator of skin lesions in pigmentation diseases. Skin Res Technol 2016; 23:104-111. [PMID: 27426874 DOI: 10.1111/srt.12309] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/21/2016] [Indexed: 11/26/2022]
Abstract
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. We harvested the outermost layer of the stratum corneum by tape-stripping, considering the outer side of the forearm as a sun-exposed area, and medial side of the upper arm as a non-exposed area. Four additional subjects were included in the analysis of change in melanin content over time at the same skin site. The anterior lower leg received a single exposure to two minimal erythema dose sunlight, and the stratum corneum was harvested from the same site over a period of 20 weeks; we subsequently quantified the levels of eumelanin and pheomelanin using high-performance liquid chromatography. RESULTS We were able to accurately quantify the eumelanin and pheomelanin contents of the stratum corneum, and to observe the evolution of the same skin site over time. Eumelanin levels were significantly higher in the sun-exposed area, with a peak in melanin observed after 11-15 weeks of sun exposure. CONCLUSION This non-invasive method can serve as a marker for pathology of skin pigmentation diseases such as malignant tumors.
Collapse
Affiliation(s)
- H Matsunaka
- Department of Dermatology, Wakayama Medical University, Wakayama, Japan
| | - Y Yamamoto
- Department of Dermatology, Wakayama Medical University, Wakayama, Japan
| | - F Furukawa
- Department of Dermatology, Wakayama Medical University, Wakayama, Japan
| |
Collapse
|
12
|
Heiduschka P, Blitgen-Heinecke P, Tura A, Kokkinou D, Julien S, Hofmeister S, Bartz-Schmidt KU, Schraermeyer U. Melanin Precursor 5,6-Dihydroxyindol: Protective Effects and Cytotoxicity on Retinal Cells in vitro and in vivo. Toxicol Pathol 2016; 35:1030-8. [DOI: 10.1080/01926230701831358] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
5,6-Dihydroxyindole (DHI) is a melanin pigment precursor with antioxidant properties. In the light of a report about cytotoxicity of DHI, the aim of this study was to assess possible toxic effects of DHI on cells related to the eye, such as human ARPE-19 cells and mouse retinal explants. Moreover, DHI was tested on its effects on retinal function in vivo using electroretinography. We found cytotoxicity of DHI against ARPE-19 cells at 100 μM, but not at 10 μM. 10 μM DHI exhibited a slight, though not significant protective activity against UV-A damage in ARPE-19 cells. We found cytoprotection in cultured mouse retinas by 50 μM DHI or its diacetylated derivative 5,6-diacetoxyindole (DAI), respectively. In ERG measurements in vivo, amplitudes were decreased only slightly by 100 μM DHI compared to saline, whereas a better preservation of amplitudes was visible at 10 μM DHI, in particular with respect to cones. In histological sections, more cones were found at 10 μM DHI than at 100 μM DHI. As a conclusion, DHI shows a slight protective effect at 10 μM both in vitro and in vivo. At 100 μM, it shows a strong cytotoxicity in vitro, which is strongly reduced in vivo.
Collapse
Affiliation(s)
- Peter Heiduschka
- Section for Experimental Vitreoretinal Surgery, University Eye Hospital Tübingen, Schleichstr. 12/1, D-72076 Tübingen, Germany
- Steinbeis Transfer Centre for Pathology and Toxicology of the Eye, Schleichstr. 12/1, D-72076 Tübingen, Germany
| | - Petra Blitgen-Heinecke
- Section for Experimental Vitreoretinal Surgery, University Eye Hospital Tübingen, Schleichstr. 12/1, D-72076 Tübingen, Germany
- Steinbeis Transfer Centre for Pathology and Toxicology of the Eye, Schleichstr. 12/1, D-72076 Tübingen, Germany
| | - Aysegül Tura
- University Eye Hospital Dept. I, Schleichstr. 12, D-72076 Tübingen, Germany
| | - Despina Kokkinou
- Section for Experimental Vitreoretinal Surgery, University Eye Hospital Tübingen, Schleichstr. 12/1, D-72076 Tübingen, Germany
| | - Sylvie Julien
- Section for Experimental Vitreoretinal Surgery, University Eye Hospital Tübingen, Schleichstr. 12/1, D-72076 Tübingen, Germany
| | - Sabine Hofmeister
- Section for Experimental Vitreoretinal Surgery, University Eye Hospital Tübingen, Schleichstr. 12/1, D-72076 Tübingen, Germany
| | | | - Ulrich Schraermeyer
- Section for Experimental Vitreoretinal Surgery, University Eye Hospital Tübingen, Schleichstr. 12/1, D-72076 Tübingen, Germany
- Steinbeis Transfer Centre for Pathology and Toxicology of the Eye, Schleichstr. 12/1, D-72076 Tübingen, Germany
| |
Collapse
|
13
|
Das P, Yuran S, Yan J, Lee PS, Reches M. Sticky tubes and magnetic hydrogels co-assembled by a short peptide and melanin-like nanoparticles. Chem Commun (Camb) 2015; 51:5432-5. [DOI: 10.1039/c4cc07671k] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The co-assembly of peptide monomers and polydopamine-based nanoparticles leads to the formation of either tubular structures decorated with adhesive particles or magnetic hydrogel.
Collapse
Affiliation(s)
- Priyadip Das
- Institute of Chemistry
- The Hebrew University of Jerusalem
- Jerusalem 91904
- Israel
- The Center for Nanoscience and Nanotechnology
| | - Sivan Yuran
- Institute of Chemistry
- The Hebrew University of Jerusalem
- Jerusalem 91904
- Israel
- The Center for Nanoscience and Nanotechnology
| | - Jian Yan
- School of Materials Science and Engineering
- Nanyang Technological University
- Singapore 639798
| | - Pooi See Lee
- School of Materials Science and Engineering
- Nanyang Technological University
- Singapore 639798
| | - Meital Reches
- Institute of Chemistry
- The Hebrew University of Jerusalem
- Jerusalem 91904
- Israel
- The Center for Nanoscience and Nanotechnology
| |
Collapse
|
14
|
Page S, Chandhoke V, Baranova A. Melanin and melanogenesis in adipose tissue: possible mechanisms for abating oxidative stress and inflammation? Obes Rev 2011; 12:e21-31. [PMID: 20576005 DOI: 10.1111/j.1467-789x.2010.00773.x] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Obesity has become a worldwide epidemic and can lead to multiple chronic diseases. Adipose tissue is increasingly thought to play an active role in obesity-related pathologies such as insulin resistance and non-alcoholic fatty liver disease. Obesity has been strongly associated with systemic inflammation and, to a lesser degree, with oxidative stress, although the causal relationships among these factors are unclear. A recent study demonstrating an expression of the components of the melanogenic pathway and the presence of melanin in visceral adipose has raised questions regarding the possible role of melanogenesis in adipose tissue. As this study also found larger amounts of melanin in the adipose tissue of obese patients relative to lean ones, we hypothesize that melanin, a pigment known for its antioxidant and anti-inflammatory properties, may scavenge reactive oxygen species and abate oxidative stress and inflammation in adipose tissue. This review considers the evidence to support such a hypothesis, and speculates on the role of melanin within adipocytes. Furthermore, we consider whether the α-melanocyte-stimulating hormone or its synthetic analogues could be used to stimulate melanin production in adipocytes, should the hypothesis be supported in future experiments.
Collapse
Affiliation(s)
- S Page
- Department of Molecular and Microbiology, College of Science, George Mason University, Fairfax Center for Liver Diseases, Inova Fairfax Hospital, Falls Church, VA, USA
| | | | | |
Collapse
|
15
|
Levin MD, Lu MM, Petrenko NB, Hawkins BJ, Gupta TH, Lang D, Buckley PT, Jochems J, Liu F, Spurney CF, Yuan LJ, Jacobson JT, Brown CB, Huang L, Beermann F, Margulies KB, Madesh M, Eberwine JH, Epstein JA, Patel VV. Melanocyte-like cells in the heart and pulmonary veins contribute to atrial arrhythmia triggers. J Clin Invest 2009; 119:3420-36. [PMID: 19855129 DOI: 10.1172/jci39109] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2009] [Accepted: 08/25/2009] [Indexed: 01/27/2023] Open
Abstract
Atrial fibrillation is the most common clinical cardiac arrhythmia. It is often initiated by ectopic beats arising from the pulmonary veins and atrium, but the source and mechanism of these beats remains unclear. The melanin synthesis enzyme dopachrome tautomerase (DCT) is involved in intracellular calcium and reactive species regulation in melanocytes. Given that dysregulation of intracellular calcium and reactive species has been described in patients with atrial fibrillation, we investigated the role of DCT in this process. Here, we characterize a unique DCT-expressing cell population within murine and human hearts that populated the pulmonary veins, atria, and atrioventricular canal. Expression profiling demonstrated that this population expressed adrenergic and muscarinic receptors and displayed transcriptional profiles distinct from dermal melanocytes. Adult mice lacking DCT displayed normal cardiac development but an increased susceptibility to atrial arrhythmias. Cultured primary cardiac melanocyte-like cells were excitable, and those lacking DCT displayed prolonged repolarization with early afterdepolarizations. Furthermore, mice with mutations in the tyrosine kinase receptor Kit lacked cardiac melanocyte-like cells and did not develop atrial arrhythmias in the absence of DCT. These data suggest that dysfunction of melanocyte-like cells in the atrium and pulmonary veins may contribute to atrial arrhythmias.
Collapse
Affiliation(s)
- Mark D Levin
- Penn Cardiovascular Institute and University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
16
|
Greco G, Wakamatsu K, Panzella L, Ito S, Napolitano A, d’Ischia M. Isomeric cysteinyldopas provide a (photo)degradable bulk component and a robust structural element in red human hair pheomelanin. Pigment Cell Melanoma Res 2009; 22:319-27. [DOI: 10.1111/j.1755-148x.2009.00561.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
|
17
|
Wolber R, Schlenz K, Wakamatsu K, Smuda C, Nakanishi Y, Hearing VJ, Ito S. Pigmentation effects of solar-simulated radiation as compared with UVA and UVB radiation. Pigment Cell Melanoma Res 2008; 21:487-91. [PMID: 18627527 DOI: 10.1111/j.1755-148x.2008.00470.x] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Different wavelengths of ultraviolet (UV) radiation elicit different responses in the skin. UVA induces immediate tanning and persistent pigment darkening through oxidation of pre-existing melanin or melanogenic precursors, while UVB induces delayed tanning which takes several days or longer to develop and requires activation of melanocytes. We compared the effects of a 2-week repetitive exposure of human skin to solar-simulated radiation (SSR), UVA or UVB at doses eliciting comparable levels of visible tanning and measured levels of melanins and melanin-related metabolites. Levels of eumelanin and pheomelanin were significantly higher in the order of SSR, UVB, UVA or unexposed control skin. Levels of free 5-S-cysteinyldopa (5SCD) were elevated about 4-fold in SSR- or UVB-exposed skin compared with UVA-exposed or control skin. Levels of protein-bound form of 5SCD tended to be higher in SSR- or UVB-exposed skin than in UVA-exposed or control skin. Total levels of 5-hydroxy-6-methoxyindole-2-carboxylic acid (5H6MI2C) and 6H5MI2C were higher in SSR- than in UVB-exposed or control skin. These results show that SSR is more effective in promoting delayed tanning than UVB radiation alone, suggesting a synergistic effect of UVA radiation. Furthermore, free 5SCD may serve as a good marker of the effect of SSR and UVB.
Collapse
Affiliation(s)
- Rainer Wolber
- Beiersdorf AG, R&D, Skin Research Center, Hamburg, Germany
| | | | | | | | | | | | | |
Collapse
|
18
|
Gidanian S, Mentelle M, Meyskens FL, Farmer PJ. Melanosomal damage in normal human melanocytes induced by UVB and metal uptake--a basis for the pro-oxidant state of melanoma. Photochem Photobiol 2008; 84:556-64. [PMID: 18331399 DOI: 10.1111/j.1751-1097.2008.00309.x] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Melanins are ubiquitous catecholic pigments, formed in organelles called melanosomes within melanocytes, the function of which is to protect skin against harmful effects of UV radiation. Melanosomes within melanoma cells are characteristically abnormal, with fragmented melanin and disrupted membranes. We hypothesize that the disruption of melanosomal melanin might be an early event in the etiology and progression of melanoma, leading to increased oxidative stress and mutation. In this report, we examine the effect of a combination of UV treatment and metal ion exposure on melanosomes within melanocytes, as well as their ability to act as pro-oxidants in ex situ experiments, and assay the effects of this treatment on viability and cell cycle progression. UVB exposure causes morphologic changes of the cells and bleaching of melanosomes in normal melanocytes, both significantly enhanced in Cu(II) and Cd(II)-treated cells, as observed by microscopy. The promoted bleaching by Cu(II) is due to its ability to redox cycle under oxidative conditions, generating reactive oxygen species; verified by the observed enhancement of hydroxyl radical generation when isolated melanosomes were treated with both Cu(II) ions and UVB, as assayed by DNA clipping. Single-dose UVB/Cu treatment does not greatly affect cell viability or cell cycle progression in heavily pigmented cells, but did so in an amelanotic early stage melanoma cell line.
Collapse
Affiliation(s)
- Shirley Gidanian
- Department of Medicine, Chao Family Comprehensive Cancer Center, University of California, Irvine, CA, USA
| | | | | | | |
Collapse
|
19
|
Cosa G, Scaiano JC. Reactivity of adrenaline toward alkoxyl radicals and carbonyl triplet states. Org Biomol Chem 2008; 6:4609-14. [DOI: 10.1039/b810765c] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
|
20
|
Samokhvalov A, Hong L, Liu Y, Garguilo J, Nemanich RJ, Edwards GS, Simon JD. Oxidation Potentials of Human Eumelanosomes and Pheomelanosomes¶. Photochem Photobiol 2007. [DOI: 10.1111/j.1751-1097.2005.tb01533.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
|
21
|
Liu Y, Hong L, Wakamatsu K, Ito S, Adhyaru B, Cheng CY, Bowers CR, Simon JD. Comparison of Structural and Chemical Properties of Black and Red Human Hair Melanosomes¶. Photochem Photobiol 2007. [DOI: 10.1111/j.1751-1097.2005.tb01532.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
22
|
Dees C, Harkins J, Petersen MG, Fisher WG, Wachter EA. Treatment of Murine Cutaneous Melanoma with Near Infrared Light¶. Photochem Photobiol 2007. [DOI: 10.1562/0031-8655(2002)0750296tomcmw2.0.co2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
|
23
|
Zhang X, Erb C, Flammer J, Nau WM. Absolute Rate Constants for the Quenching of Reactive Excited States by Melanin and Related 5,6-Dihydroxyindole Metabolites: Implications for Their Antioxidant Activity. Photochem Photobiol 2007. [DOI: 10.1562/0031-8655(2000)0710524arcftq2.0.co2] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
|
24
|
Miyamura Y, Coelho SG, Wolber R, Miller SA, Wakamatsu K, Zmudzka BZ, Ito S, Smuda C, Passeron T, Choi W, Batzer J, Yamaguchi Y, Beer JZ, Hearing VJ. Regulation of human skin pigmentation and responses to ultraviolet radiation. ACTA ACUST UNITED AC 2007; 20:2-13. [PMID: 17250543 DOI: 10.1111/j.1600-0749.2006.00358.x] [Citation(s) in RCA: 161] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Pigmentation of human skin is closely involved in protection against environmental stresses, in particular exposure to ultraviolet (UV) radiation. It is well known that darker skin is significantly more resistant to the damaging effects of UV, such as photocarcinogenesis and photoaging, than is lighter skin. Constitutive skin pigmentation depends on the amount of melanin and its distribution in that tissue. Melanin is significantly photoprotective and epidermal cells in darker skin incur less DNA damage than do those in lighter skin. This review summarizes current understanding of the regulation of constitutive human skin pigmentation and responses to UV radiation, with emphasis on physiological factors that influence those processes. Further research is needed to characterize the role of skin pigmentation to reduce photocarcinogenesis and to develop effective strategies to minimize such risks.
Collapse
Affiliation(s)
- Yoshinori Miyamura
- Laboratory of Cell Biology, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
25
|
Kiama SG, Maina JN, Bhattacharjee J, Mwangi DK, Macharia RG, Weyrauch KD. The morphology of the pecten oculi of the ostrich, Struthio camelus. Ann Anat 2006; 188:519-28. [PMID: 17140144 DOI: 10.1016/j.aanat.2006.06.004] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The pecten oculi is a structure peculiar to the avian eye. Three morphological types of pecten oculi are recognized: conical type, vaned type and pleated type. The pleated type has been well studied. However, there exists only scanty data on the morphology of the latter two types of pectens. The structure of the vaned type of pecten of the ostrich, Struthio camelus was investigated with light and electron microscope. The pecten of this species consists of a vertical primary lamella that arises from the optic disc and supports 16-19 laterally located secondary lamellae, which run from the base and confluence at the apex. Some of the secondary lamellae give rise to 2 or 3 tertiary lamellae. The lamellae provide a wide surface, which supports 2-3 Layers of blood capillaries. Pigmentation is highest at the distal ends of the secondary and tertiary Lamella where blood capillaries are concentrated and very scanty on the primary and the proximal ends of the secondary lamella where the presence of capillaries is much reduced. In contrast to the capillaries of the pleated pecten, the endothelium of the capillaries in the pecten of the ostrich exhibits very few microvilli. These observations suggest that the morphology of the pecten of the ostrich, a flightless ratite bird is unique to the pleated pecten and is designed to meet the balance between optimal vision and large surface area for blood supply and yet ensuring it is kept firmly erect within the vitreous.
Collapse
Affiliation(s)
- S G Kiama
- Department of Veterinary Anatomy and Physiology, University of Nairobi, P.O. Box 30197, Nairobi, Kenya.
| | | | | | | | | | | |
Collapse
|
26
|
An BJ, Kwak JH, Park JM, Lee JY, Park TS, Lee JT, Son JH, Jo C, Byun MW. Inhibition of Enzyme Activities and the Antiwrinkle Effect of Polyphenol Isolated from the Persimmon Leaf (Diospyros kaki folium) on Human Skin. Dermatol Surg 2006; 31:848-54; discussion 854. [PMID: 16029677 DOI: 10.1111/j.1524-4725.2005.31730] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
BACKGROUND Many studies have been conducted to find a natural material that has high biologic functions for human skin without any side effects. Persimmon leaf has a substantial amount of tannins in different forms; therefore, it was selected as a target material. OBJECTIVE The biosynthesis rate of the collagen was also investigated to clarify the beneficial functions for the human skin. METHODS Persimmon leaves were obtained, extracted with 80% ethanol, and isolated into PFs I, II, and III after column chromatography using a Sephadex LH-20 column followed by thin-layer chromatography. RESULTS The xanthine oxidase inhibition effect of both PFs II and III was over 40% at a 100 ppm concentration. PF II, containing higher flavonoids levels, had a significantly higher tyrosinase inhibition than that of PF III. Collagenase inhibition was 16.3 and 8.1% for PF III and PF II, respectively, at 100 ppm. On the other hand, elastase inhibition activity was significantly higher in PF II than PF III. Collagen biosynthesis rates of PF III were over 25% from a 1 to 10 ppm concentration. Consequently, PFs isolated from the persimmon leaf can be used as natural materials or additives for human skin owing to their beneficial biologic functions, including the antiwrinkle effect and the inhibition of skin problems, for food or cosmetic compositions.
Collapse
Affiliation(s)
- Bong-Jeun An
- Department of Cosmeceutical Sciene, Daegu Haany University, 712-715 Kyungsan, South Korea.
| | | | | | | | | | | | | | | | | |
Collapse
|
27
|
Haywood RM, Lee M, Linge C. Synthetic melanin is a model for soluble natural eumelanin in UVA-photosensitised superoxide production. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2006; 82:224-35. [PMID: 16446096 DOI: 10.1016/j.jphotobiol.2005.12.007] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2005] [Revised: 12/02/2005] [Accepted: 12/07/2005] [Indexed: 11/17/2022]
Abstract
Studies to UV-irradiate natural eumelanins in vitro have used insoluble pigment obtained by acid hydrolysis, which lacks melanoprotein. Eumelanin synthesised in the presence of a protein is not insoluble, and the insoluble form of melanin from acid hydrolysis may not have the same physicochemical properties as the natural pigment synthesised in vivo in the melanosome. Here we investigated radical production by three natural eumelanins exposed to solar levels of UVA; sepia melanin from Sepia officinalis, and eumelanins isolated from Oriental human and domestic cat hair. UVA irradiation of sepia melanin in solution at pH 4.5 in the presence of the spin trap 5,5-dimethyl-1-pyrroline N-oxide (DMPO) gave hydroperoxyl and hydroxyl radical-adducts, maximal at 0.6-2.5 mg/ml melanin concentrations. Hydroperoxyl radical production was relatively low in acetate buffer, but detected in aqueous suspensions of sepia melanin. Hair eumelanins were photoreactive with hydroperoxyl radical-adduct production at low concentrations (0.1-0.4 mg/ml melanin). Synthetic pigment after synthesis undergoes photo-oxidation (producing superoxide) at low concentrations (0.3 mg/ml) and its oxidation increases the photoreactivity at higher melanin concentrations. These findings may be physiologically relevant to the properties and function of eumelanin in vivo when it is at low concentration (found in a small proportion of Caucasian melanocytes), and suggest that synthetic melanin has the potential for the basis of a model for natural eumelanin.
Collapse
Affiliation(s)
- Rachel M Haywood
- RAFT Institute of Plastic Surgery, Mount Vernon Hospital, Northwood, Middlesex, HA6 2RN, UK.
| | | | | |
Collapse
|
28
|
Liu Y, Hong L, Wakamatsu K, Ito S, Adhyaru B, Cheng CY, Bowers CR, Simon JD. Comparison of structural and chemical properties of black and red human hair melanosomes. Photochem Photobiol 2005; 81:135-44. [PMID: 15504086 DOI: 10.1562/2004-08-03-ra-259.1] [Citation(s) in RCA: 134] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Melanosomes in black and red human hair are isolated and characterized by various chemical and physical techniques. Different yields of 4-amino-hydroxyphenolanaline by HI hydrolysis (a marker for pheomelanin) and pyrrole-2,3,5-tricarboxylic acid by KMnO(4)/H(+) oxidation (a marker for eumelanin) indicate that the melanosomes in black hair are eumelanosomes, whereas those in red hair are mainly pheomelanosomes. Atomic force microscopy reveals that eumelanosomes and pheomelanosomes have ellipsoidal and spherical shapes, respectively. Eumelanosomes maintain structural integrity upon extraction from the keratin matrix, whereas pheomelanosomes tend to fall apart. The black-hair eumelanosomes have an average of 14.6 +/- 0.5% amino acids content, which is attributed to the internal proteins entrapped in the melanosomes granules. The red-hair melanosomes contain more than 44% of amino acid content even after extensive proteolytic digestion. This high content of amino acids and the poorly reserved integrity of red-hair melanosomes suggest that some proteins are possibly covalently bonded with the melanin constituents in addition to those that are entrapped inside the melanin species. Soluene solubilization assay indicates the absorbance of melanin per gram of sample, adjusted for the amino acid content, is a factor of 2.9 greater for the black-hair melanosomes than the red-hair melanosomes. Metal analysis reveals significant amounts of diverse heavy metal ions bound to the two types of melanosomes. The amount of Cu(II) and Zn(II) are similar but Fe(III) content is four times higher in the red-hair melanosomes. (13)C solid-state nuclear magnetic resonance spectra and infrared spectra are presented and are shown to be powerful techniques for discerning differences in the amino acid contents, the 5,6-dihydroxyindole-2-carboxylic acid:5,6-dihydroxyindole ratio, and the degree of cross-linking in the pigment. Excellent agreement is observed between these spectral results and the chemical degradation data.
Collapse
Affiliation(s)
- Yan Liu
- Department of Chemistry, Duke University, Durham, NC 27708, USA
| | | | | | | | | | | | | | | |
Collapse
|
29
|
Kvam E, Dahle J. The pheomelanin precursor 5-S-cysteinyldopa protects melanocytes from membrane damage induced by ultraviolet A radiation. Cancer Lett 2005; 221:131-4. [PMID: 15808398 DOI: 10.1016/j.canlet.2004.08.025] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2004] [Revised: 08/13/2004] [Accepted: 08/16/2004] [Indexed: 10/26/2022]
Abstract
Pheomelanin and pheomelanin precursors have been implicated as risk factors for induction of melanoma by ultraviolet radiation. The pheomelanin precursor, 5-S-cysteinyldopa, has been shown to sensitise DNA to oxidative damage by ultraviolet radiation. We here show that 5-S-cysteinyldopa significantly protects melanocytes from membrane damage (permeability) induced by ultraviolet A radiation. Thus, 5-S-cysteinyldopa, may at the same time sensitise DNA and protect membranes from damage induced by ultraviolet radiation.
Collapse
Affiliation(s)
- Egil Kvam
- Department of Radiation Biology, The Norwegian Radium Hospital, Montebello, 0310 Oslo, Norway.
| | | |
Collapse
|
30
|
Samokhvalov A, Hong L, Liu Y, Garguilo J, Nemanich RJ, Edwards GS, Simon JD. Oxidation Potentials of Human Eumelanosomes and Pheomelanosomes¶. Photochem Photobiol 2005. [DOI: 10.1562/2004-07-23-rc-245.1] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
|
31
|
d’Ischia M, Napolitano A, Pezzella A, Land EJ, Ramsden CA, Riley PA. 5,6-Dihydroxyindoles and Indole-5,6-diones. ADVANCES IN HETEROCYCLIC CHEMISTRY 2005. [DOI: 10.1016/s0065-2725(05)89001-4] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
|
32
|
Rad HH, Yamashita T, Jin HY, Hirosaki K, Wakamatsu K, Ito S, Jimbow K. Tyrosinase-related proteins suppress tyrosinase-mediated cell death of melanocytes and melanoma cells. Exp Cell Res 2004; 298:317-28. [PMID: 15265682 DOI: 10.1016/j.yexcr.2004.04.045] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2003] [Revised: 03/22/2004] [Indexed: 11/21/2022]
Abstract
The synthesis of melanin intermediates through tyrosinase (TYR) involves the production of cytotoxic free radicals. By using recombinant adenoviruses that express TYR, tyrosinase-related protein 1 (TYRP1) or DOPAchrome tautomerase (DCT), we analyzed the biological function of these proteins with regard to melanin production and the growth of melanocytes, fibroblasts, melanoma cells and nonmelanoma cancer cells. High-level expression of TYR produced newly synthesized melanin and induced cell death in all of these cells. However, when TYRP1 or DCT was coexpressed with TYR in melanocytes and melanoma cells, TYR-mediated cell death was clearly decreased. This decrease was not observed in nonmelanocytic cells. Western blot analysis and measurement of enzyme activity revealed that the expression of TYRP1 or DCT had little effect on the amount or activity of cointroduced TYR in either the melanocytic or nonmelanocytic cells. In cells expressing both TYR and TYRP1 or TYR and DCT, the total amount of melanin and/or eumelanin increased substantially more than that in cells expressing TYR alone. On the other hand, the level of pheomelanin was similar in these three cell types. These findings suggest that TYRP1 and DCT play an important role in suppressing TYR-mediated cytotoxicity in melanocytic cells without decreasing TYR expression and/or activity. These biological activities of TYRP1 and DCT may work through the interaction with TYR in melanosomal compartment.
Collapse
Affiliation(s)
- Hesamaddin Hejazy Rad
- Department of Dermatology, School of Medicine, Sapporo Medical University, Chuo, Sapporo 060-8543, Japan
| | | | | | | | | | | | | |
Collapse
|
33
|
Yoneta A, Yamashita T, Jin HY, Kondo S, Jimbow K. Ectopic expression of tyrosinase increases melanin synthesis and cell death following UVB irradiation in fibroblasts from familial atypical multiple mole and melanoma (FAMMM) patients. Melanoma Res 2004; 14:387-94. [PMID: 15457095 DOI: 10.1097/00008390-200410000-00009] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Patients with familial atypical multiple mole and melanoma (FAMMM) [so-called familial dysplastic naevus syndrome (FDNS)] have a high risk for the development of malignant melanoma. The underlying gene defect has an autosomal dominant inheritance with variable expression and incomplete penetrance. Fibroblasts derived from FAMMM patients have high sensitivity to UVC and mutagens, e.g. 4-nitroquinoline-1-oxide. We were interested in identifying how the combination of inherent sensitivity to UV light and abnormal melanin synthesis interacts in the development of melanoma in FAMMM patients. Intermediates of melanin synthesis produce free radicals that are toxic to cells. Atypical moles (dysplastic naevi) are engaged in the biosynthesis of abnormal melanin pigments. This study examined whether there was any abnormal melanin pigmentation or cell damage after the ectopic expression of tyrosinase in fibroblasts from FAMMM patients when compared with fibroblasts from normal subjects. Fibroblasts from FAMMM patients (3012T and 3072T) were associated with a higher sensitivity than normal human fibroblasts to the toxicity of UVB. When cells were infected with tyrosinase-expressing adenovirus (Ad-HT) and irradiated with UVB, FAMMM fibroblasts showed higher tyrosinase activity, produced more melanin pigments and were degraded more significantly than normal human fibroblasts. Western blot analysis revealed that Ad-HT-infected 3072T produced a larger amount of tyrosinase protein than did Ad-HT-infected normal fibroblasts after UVB irradiation. Our findings suggest: (1) that FAMMM fibroblasts have an unknown machinery which enhances tyrosinase expression by UVB irradiation; and (2) that the resulting increase in melanin synthesis affects the cytotoxicity of UVB to FAMMM fibroblasts. All of these processes may be involved in the genomic instability and development of melanoma in FAMMM patients.
Collapse
Affiliation(s)
- Akihiro Yoneta
- Department of Dermatology, Sapporo Medical University School of Medicine, South 1, West 16, Chuo-ku, Sapporo 060-8543, Japan
| | | | | | | | | |
Collapse
|
34
|
Abstract
There is a large range of human skin color, yet we know very little about the underlying genetic architecture. Is the number of skin color genes close to five, 50, or 500?
Collapse
Affiliation(s)
- Gregory S Barsh
- Department of Genetics, Howard Hughes Medical Institute, Stanford University School of Medicine, Stanford, California, USA.
| |
Collapse
|
35
|
Ye T, Simon JD. Comparison of the Ultrafast Absorption Dynamics of Eumelanin and Pheomelanin. J Phys Chem B 2003. [DOI: 10.1021/jp0352837] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
36
|
Abstract
The dominant skin pigment melanin is believed to protect human skin against several harmful effects of ultraviolet radiation. It is not clear, however, how melanin located inside melanin-producing melanocytes modulates the effect of ultraviolet radiation on melanocytes themselves. We have determined membrane damage in pigmented and unpigmented albino mouse melanocytes after ultraviolet A radiation, which is suspected to induce melanoma. Unpigmented cells were much more susceptible to ultraviolet-A-induced membrane permeability than pigmented cells. Unpigmented cells were also more susceptible to ultraviolet-A-induced lipid peroxidation than strongly pigmented cells. Furthermore, unpigmented cells were much more susceptible to ultraviolet-A-induced depletion of glutathione than pigmented cells. Reduced glutathione is known to be a major antioxidant of unpigmented skin cells such as fibroblasts and keratinocytes. To examine whether or not glutathione is also a major antioxidant in melanocytes, melanocytes were depleted of glutathione by means of buthionine sulfoximine. We found that depletion of glutathione in pigmented melanocytes did not change lipid damage induced by ultraviolet A radiation. In unpigmented melanocytes, however, depletion of glutathione significantly increased lipid damage induced by ultraviolet A radiation. Thus, pigmented melanocytes apparently contain antioxidants more potent than glutathione, protecting them from ultraviolet-A-induced membrane damage.
Collapse
Affiliation(s)
- Egil Kvam
- Department of Biophysics, The Norwegian Radium Hospital, Montebello, 0310 Oslo, Norway.
| | | |
Collapse
|
37
|
Abstract
Melanins are a ubiquitous class of biological pigments, which play an important role in the photoprotection of skin. Recent advances in the chemistry of melanins have demonstrated their diversity. The various types of melanin show different physico-chemical properties, suggesting that their photobiological properties are not unique. In this review, the implications of melanin diversity for the natural photoprotection of skin are discussed.
Collapse
Affiliation(s)
- Jean-Paul Ortonne
- CHU Nice, Service de Dermatologie, Hôpital l'Archet 2, BP 3079, 06202 Nice cedex, France.
| |
Collapse
|
38
|
Dees C, Harkins J, Petersen MG, Fisher WG, Wachter EA. Treatment of murine cutaneous melanoma with near infrared light. Photochem Photobiol 2002; 75:296-301. [PMID: 11950096 DOI: 10.1562/0031-8655(2002)075<0296:tomcmw>2.0.co;2] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Treatment of cutaneous melanoma (M-3 and B16-F10 implanted in mice) with rapidly-scanned, tightly-focused near infrared light elicits selective destruction of tumor tissue. A single laser treatment yielded complete eradication in >90% of B16-F10 tumors with thicknesses of approximately 3 mm; amelanotic M-3 tumors proved less responsive (ca 25% clearance rate). In addition to local tumor destruction, laser treatment of B16-F10 tumors in immunocompetent mice stimulated enhanced cytokine levels (interleukin-2 and interleukin-10) within treated tumor tissues and rejection of tumor cells upon a subsequent challenge dose. Such an antitumor immune response may lead to improved outcomes at both the treatment site and at sites of distant metastasis.
Collapse
Affiliation(s)
- C Dees
- Photongen, Inc., Knoxville, TN 37931, USA
| | | | | | | | | |
Collapse
|
39
|
Cario-André M, Pain C, Gall Y, Ginestar J, Nikaido O, Taïeb A. Studies on epidermis reconstructed with and without melanocytes: melanocytes prevent sunburn cell formation but not appearance of DNA damaged cells in fair-skinned caucasians. J Invest Dermatol 2000; 115:193-9. [PMID: 10951235 DOI: 10.1046/j.1523-1747.2000.00007.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
To assess the photoprotective role of melanocytes in the epidermis, we studied the effects of ultraviolet B on an epidermis reconstructed with and without melanocytes. To address more specifically the role of melanin in fair-skinned individuals, experiments were done with cells obtained from human skin of low phototypes (II-III). To study the effect of constitutive melanin and possibly that of newly synthesized melanin precursors, a single dose of ultraviolet B (0.10 or 0.15 J per cm2, corresponding to a 4-5 minimal erythema dose in vivo) was administered to reconstructs and the effects were monitored over the first 24 h. When reconstructs with and without melanocytes were compared, no difference was found for DNA damage/repair assessed with antibodies to cyclobutane pyrimidine dimers and 6-4 photoproducts. More necrotic/apoptotic cells, however, were noted 24 h following ultraviolet B irradiation in reconstructs lacking melanocytes. Twenty-four hours following ultraviolet B irradiation the number of necrotic/apoptotic cells and the number of cyclobutane pyrimidine dimer positive cells was coarsely concentration-dependent. The number of cyclobutane pyrimidine dimer positive cells, however, was independent of the type of reconstruct used (with/without melanocytes). In conclusion, low phototype melanocytes seem to protect epidermal basal cells against ultraviolet B-induced apoptosis/necrosis and may preserve the overall integrity of the epidermis after ultraviolet B irradiation. On the contrary, such melanocytes do not seem to have a protective role against DNA damage and may not prevent cancer.
Collapse
Affiliation(s)
- M Cario-André
- Unité de Dermatologie, Université Victor Ségalen Bordeaux II, Bordeaux, France
| | | | | | | | | | | |
Collapse
|
40
|
Novellino L, Napolitano A, Prota G. Isolation and characterization of mammalian eumelanins from hair and irides. BIOCHIMICA ET BIOPHYSICA ACTA 2000; 1475:295-306. [PMID: 10913829 DOI: 10.1016/s0304-4165(00)00080-5] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
A new enzymatic procedure was developed for isolation of eumelanin from black human hair which might provide a substantially intact pigment for structural characterization. Sequential digestion with protease, proteinase K and papaine in the presence of dithiothreitol afforded a pigment with a 6% w/w protein content. HPLC analysis of pyrrole acids resulting from alkaline H(2)O(2) degradation, carboxyl content determination, and ferricyanide titration showed that the isolated pigment is made up of 5,6-dihydroxyindole (DHI)- and 5, 6-dihydroxyindole-2-carboxylic acid (DHICA)-derived units at a 6:1 ratio, exhibiting a significant degree of oxidative degradation. For comparison, a different eumelanin isolated from black bovine irides by a similar enzymatic procedure was analyzed. Matrix-assisted laser desorption ionization (MALDI) mass spectrometry of the final pigment provided evidence for homologous series of DHICA oligomers, while chemical analysis allowed an estimate of 2:1 DHICA/DHI-derived units in the polymer, with a substantial proportion of intact o-diphenolic functions. Iris melanin proved able to promote the Fenton oxidation of deoxyribose while hair melanin was ineffective. Overall, these results provide, for the first time, unambiguous evidence for marked structural differences of mammalian eumelanins which may be directly related to the diversity of the sites of biosynthesis and storage, as well as to functional role of these pigments.
Collapse
Affiliation(s)
- L Novellino
- Department of Organic and Biological Chemistry, University of Naples Federico II, Via Mezzocannone 16, I-80134 Naples, Italy
| | | | | |
Collapse
|
41
|
Zhang X, Erb C, Flammer J, Nau WM. Absolute rate constants for the quenching of reactive excited states by melanin and related 5,6-dihydroxyindole metabolites: implications for their antioxidant activity. Photochem Photobiol 2000; 71:524-33. [PMID: 10818782 DOI: 10.1562/0031-8655(2000)071<0524:arcftq>2.0.co;2] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The triplet-excited state of benzophenone and the singlet-excited state of 2,3-diazabicyclo[2.2.2]oct-2-ene (Fluorazophore-P) have been employed as kinetic probes to obtain information on the antioxidant activity of the skin and eye pigment melanin and its biogenetic precursors 5,6-dihydroxyindole (DHI) and 5,6-dihydroxyindole-2-carboxylic acid (DHICA). The excited states were generated by the laser-flash photolysis technique and their reaction kinetics was examined by time-resolved transient absorption or fluorescence spectroscopy, respectively. The reaction between triplet benzophenone and DHI produced with unit efficiency the corresponding 6O-centered semiquinone radical, which was characterized by its characteristic transient absorption. The quenching rate constants for DHI (3.1-8.4 x 10(9) M-1 s-1) and DHICA (3.3-5.5 x 10(9) M-1 s-1) were near the diffusion-controlled limit, indicating excellent antioxidant properties. Kinetic solvent effects were observed. The reactivity of synthetic melanin, assessed through the quenching rate constant of Fluorazophore-P and normalized to the number of monomer units, was more than one order of magnitude lower (2.7 x 10(8) M-1 s-1) than that of its precursors. The trend of the quenching rate constants, i.e. DHI > DHICA approximately alpha-tocopherol > melanin, along with the preferential solubility of DHICA in aqueous environments, serves to account for several experimental results from biochemical studies on the inhibition of lipid peroxidation by these natural antioxidants.
Collapse
Affiliation(s)
- X Zhang
- Departement Chemie, Universität Basel, Switzerland
| | | | | | | |
Collapse
|
42
|
Kvam E, Tyrrell RM. The role of melanin in the induction of oxidative DNA base damage by ultraviolet A irradiation of DNA or melanoma cells. J Invest Dermatol 1999; 113:209-13. [PMID: 10469305 DOI: 10.1046/j.1523-1747.1999.00653.x] [Citation(s) in RCA: 83] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Highly pigmented, dark skin is more resistant to the harmful effects of solar ultraviolet radiation than light-colored human skin. The extent to which tanning protects skin from harmful effects including induction of skin cancer is not known, however. We have investigated whether the skin pigment, melanin, sensitizes or protects isolated DNA or nuclear DNA in melanoma cells from the induction of the premutagenic oxidative DNA base damage, 8-hydroxy-deoxyguanosine, by ultraviolet A irradiation. Synthetic eumelanin sensitized isolated DNA to induction of the oxidative DNA base damage by ultraviolet A, but it also induced the oxidative DNA base damage in the dark. To study the role of natural melanin in mammalian melanoma cells in the induction of oxidative DNA base damage, melanin synthesis was modulated 5-7-fold in the human melanoma cells GLL19 and IGR1 (which contain both pheomelanin and eumelanin) as well as in the mouse melanoma cells B16 (which contain mainly eumelanin). Increased melanin synthesis clearly did not protect against ultraviolet A-induced oxidative DNA base damage in cells. On the contrary, the human melanoma cells with high melanin content accumulated two times more 8-hydroxy-deoxyguanosine after ultraviolet A irradiation than cells with low melanin content. Furthermore, preirradiation of the human melanoma cells, IGR1, with ultraviolet A 4 h before a second ultraviolet A exposure produced an altered amount of induced 8-hydroxy-deoxyguanosine dependent on the melanin content of the cells. We conclude that stimulation of melanin synthesis, but probably not melanin itself, increases the susceptibility of human melanoma cells to induction of premutagenic oxidative DNA base damage by ultraviolet A irradiation.
Collapse
Affiliation(s)
- E Kvam
- Department of Pharmacy and Pharmacology, University of Bath, U.K
| | | |
Collapse
|
43
|
Virador VM, Kobayashi N, Matsunaga J, Hearing VJ. A standardized protocol for assessing regulators of pigmentation. Anal Biochem 1999; 270:207-19. [PMID: 10334838 DOI: 10.1006/abio.1999.4090] [Citation(s) in RCA: 95] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Varied effects of chemical or biological compounds on mammalian pigmentation have been reported by many groups, but to date, no standardized method has established necessary and/or optimal parameters for testing such agents. A standardized method has been developed to screen compounds with potential effects on pigmentation. The protocol comprises basic parameters to analyze melanogenic effects and allows for further characterization of candidate compounds, providing important insights into their mechanism of action. In this protocol (termed STOPR, for standardized testing of pigmentation regulators), compounds are initially screened using purified tyrosinase and are then tested on melanocytes in culture. After treatment of melanocytes with potentially bioactive compounds, cell proliferation and viability, total melanin accumulated, and melanogenic potential are measured. This protocol is an important first step in characterizing chemical regulation of effects on melanogenesis. When bioactive candidate compounds are identified, testing may proceed for pharmacological or otherwise commercial applications in coculture and/or organ culture models followed by in vivo testing. As an application of this method, results for compounds known to stimulate and/or inhibit melanogenesis (including arbutin, hydroquinone, kojic acid, melanocyte-stimulating hormone, and thymidine dimers) as well as some commercial skin whiteners are reported.
Collapse
Affiliation(s)
- V M Virador
- Laboratory of Cell Biology, National Institutes of Health, Bethesda, Maryland 20892, USA
| | | | | | | |
Collapse
|
44
|
Wróbel D, Hanyż I, Planner A, Dudkowiak A, Sarna T. Energy deactivation pathways of porphyrins and dopa melanin in polyvinyl alcohol systems. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 1998. [DOI: 10.1016/s1011-1344(98)00217-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
|
45
|
Abstract
Identification and characterisation of the genes involved in melanin pigment formation, together with the study of how their action is influenced by exposure to UV radiation, is providing a molecular understanding of the process of skin photoprotection through tanning. The mechanisms underlying this change in epidermal melanin involve both a transcriptional response of the pigmentation genes and post-translational control of the melanin biosynthetic pathway. UV rays are known to interact with numerous molecules within cells, and among these the photochemical reactions involving lipids and DNA are implicated in modulating melanogenesis. The combination of DNA damage, the formation of diacylglycerol, and the action of the melanocyte stimulating hormone receptor are all likely to be involved in UV-induced tanning.
Collapse
Affiliation(s)
- R A Sturm
- Centre for Molecular and Cellular Biology, The University of Queensland, Brisbane, Australia.
| |
Collapse
|
46
|
Menter JM, Patta AM, Hollins TD, Moore CL, Willis I. Photoprotection of Mammalian Acid-Soluble Collagen by Cuttlefish Sepia Melanin In Vitro. Photochem Photobiol 1998. [DOI: 10.1111/j.1751-1097.1998.tb02510.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
|
47
|
Novellino L, d'Ischia M, Prota G. Nitric oxide-induced oxidation of 5,6-dihydroxyindole and 5,6-dihydroxyindole-2-carboxylic acid under aerobic conditions: non-enzymatic route to melanin pigments of potential relevance to skin (photo)protection. BIOCHIMICA ET BIOPHYSICA ACTA 1998; 1425:27-35. [PMID: 9813229 DOI: 10.1016/s0304-4165(98)00060-9] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Diffusible melanin-related metabolites have recently been suggested to subserve a variety of functions that are critical for protection of skin against inflammatory stimuli and oxidative tissue injury. We report here the results of in vitro studies showing that 5,6-dihydroxyindole (DHI) and its 2-carboxylic acid (DHICA) exhibit a marked reactivity toward potentially cytotoxic nitrogen oxides produced by autoxidation of nitric oxide (NO) under physiologically relevant conditions. Exposure of DHI or DHICA to NO in air-equilibrated 0.1 M phosphate buffer, pH 7.4, resulted in a fast, concentration-dependent consumption of the substrates and the concomitant deposition of dark melanin-like pigments. All NO-induced oxidations were completely inhibited in the absence of oxygen. Addition of 10 microM DHI and DHICA completely prevented the oxidation of 10 microM alpha-tocopherol in 0.1 M phosphate buffer, pH 7.4 in the presence of 300 microM NO. Overall, these results shed light on novel oxidative pathways of melanin-related metabolites of possible relevance to the mechanisms of skin hyperpigmentation under oxidative stress conditions.
Collapse
Affiliation(s)
- L Novellino
- Department of Organic and Biological Chemistry, University of Naples Federico II, Italy
| | | | | |
Collapse
|
48
|
Ota A, Park JS, Jimbow K. Functional regulation of tyrosinase and LAMP gene family of melanogenesis and cell death in immortal murine melanocytes after repeated exposure to ultraviolet B. Br J Dermatol 1998; 139:207-15. [PMID: 9767233 DOI: 10.1046/j.1365-2133.1998.02356.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
This study characterizes the induction of melanogenesis and the expression of tyrosinase, tyrosinase-related protein (TRP) and lysosome-associated membrane protein (LAMP) gene families in the cultured melanocyte lines of non-agouti mice with four major genetic loci, i.e. melan-a2 (black, wild type), melan-b (brown, TRP-1 mutation), melan-s (black, piebaldism mutation) and melan-c (white, tyrosinase mutation) in response to repeated exposure to ultraviolet (UV) B (5 mJ/cm2, 7 consecutive days). Electron microscopy showed that new melanogenesis was induced in melan-a2, melan-s and melan-b melanocytes. Melan-a2, melan-s and melan-b showed an almost twofold increase in tyrosinase activity and gene expression with increased synthesis of melanosomes, although melan-b showed a minimum increase in tyrosinase activity. There was a twofold upregulation of LAMP-1 mRNA but no alteration in LAMP-2 and LAMP-3 mRNA expression in melan-a2, while there was no alteration in LAMP-1 mRNA expression but increased expression of LAMP-2 and LAMP-3 mRNA in melan-s, LAMP-3 showing a higher increase. Melan-b cells showed the same gene expression of LAMP-1, LAMP-2 and LAMP-3 as that of non-UV exposed cells. All three lines, however, exhibited simultaneously cell death, melan-b reaching the highest rate of cell death (96.5%). In contrast, melan-c, which did not have any tyrosinase activity with failure of melanogenesis induction, expressed all the mRNAs of the tyrosinase and LAMP gene families, but was not associated with any significant melanocyte death. Our study indicated: (i) that melanogenesis induction and melanocyte death are two photobiological processes occurring simultaneously after repeated UVB exposure, (ii) that in response to an upregulation of tyrosinase mRNA and enzymic activity, there was a co-ordinated upregulation of the LAMP-1 gene in wild type melan-a2, while no upregulation was found in melan-s and melan-b mutants, and (iii) that UV-induced melanocyte death is related to the upregulation of the tyrosinase gene, induction of new melanogenesis and mutation of the TRP-1 gene in immortal murine melanocytes.
Collapse
Affiliation(s)
- A Ota
- Dermatology and Cutaneous Sciences, Faculty of Medicine, University of Alberta, Edmonton, Canada
| | | | | |
Collapse
|
49
|
Steenvoorden DP, van Henegouwen GM. The use of endogenous antioxidants to improve photoprotection. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY. B, BIOLOGY 1997; 41:1-10. [PMID: 9440308 DOI: 10.1016/s1011-1344(97)00081-x] [Citation(s) in RCA: 144] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The skin possesses an elaborate antioxidant defence system to deal with UV-induced oxidative stress. However, excessive exposure to UV can overwhelm the cutaneous antioxidant capacity, leading to oxidative damage and ultimately to skin cancer, immunosuppression and premature skin aging. Therefore, an interesting strategy for photoprotection is the support of the endogenous antioxidant system. This can be accomplished by induction or transdermal delivery of the various antioxidant enzymes, such as glutathione peroxidase, catalase, or superoxide dismutase. Supplementation of non-enzymatic antioxidants such as glutathione, alpha-tocopherol, ascorbate and beta-carotene was also found to be very effective in photoprotection. Although treatments with single components of the antioxidant system were successful against a wide variety of photodamage, the balance between the different antioxidants in the skin is very important. In some studies, it was found that too much of a single component could even have deleterious effects. The most promising results were obtained in studies combining several compounds, often resulting in synergism of the protective effects.
Collapse
Affiliation(s)
- D P Steenvoorden
- Department of Medicinal Photochemistry, Leiden/Amsterdam Centre for Drug Research, University of Leiden, The Netherlands.
| | | |
Collapse
|
50
|
Wróbel D, Planner A, Hanyz I, Wielgus A, Sarna T. Melanin-porphyrin interaction monitored by delayed luminescence and photoacoustics. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY. B, BIOLOGY 1997; 41:45-52. [PMID: 9440313 DOI: 10.1016/s1011-1344(97)00079-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Even though melanin is commonly viewed as a photoprotective agent, the molecular mechanism of the melanin-related photoprotective action remains unclear. We studied the interaction of a synthetic dopa melanin with positively and negatively charged porphyrins using an array of spectroscopic techniques. Thus absorption, fluorescence, time-resolved delayed luminescence in the microsecond time range, and photoacoustic spectra at different modulation frequencies of both porphyrins and their mixtures with dopa melanin were measured in buffered aqueous solution at room temperature. It has been confirmed that dopa melanin forms a complex with the cationic porphyrin in its ground state, which significantly modifies the optical properties of the dye molecule. Although no such complex can be detected for the anionic porphyrin, some interaction between melanin and the porphyrin molecule can be detected in its excited state. Both porphyrins show delayed luminescence with a decay time of 35-38 microseconds, which is substantially reduced by melanin. Our photoacoustic measurements indicate that upon photoexcitation, melanin efficiently liberates heat. Our data also suggest that the thermal properties of melanin can be modified by porphyrins, particularly by the cationic form of the dye. The ionic complexes of dopa melanin with the positively charged porphyrin exhibit properties typical for a supermolecular system that liberates heat as a whole.
Collapse
Affiliation(s)
- D Wróbel
- Molecular Physics Department, Institute of Physics, Poznań, University of Technology, Poland
| | | | | | | | | |
Collapse
|