Physiological and Pathological Functions of Melanosomes

Borovanský, J; Riley, Patrick A.

doi:10.1002/9783527636150.ch12

Cited by 50 publications

(75 citation statements)

References 153 publications

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“…In contrast to the biosynthetic pathway of pigmentation and melanosome biogenesis, which has been extensively described (Borovanský and Riley, 2011;Hearing, 2011), the data available for melanin and melanosome biodegradation remain limited and ambiguous (Borovanský and Elleder, 2003). This unfavorable situation leaves many essential questions unanswered: (i) are eumelanin and pheomelanin in the skin, hair, and eyes photodegraded in structure (or photobleached in Figure 1.…”

Section: Significancementioning

confidence: 99%

UVA‐induced oxidative degradation of melanins: fission of indole moiety in eumelanin and conversion to benzothiazole moiety in pheomelanin

Wakamatsu

Nakanishi

Miyazaki

et al. 2012

Pigment Cell Melanoma Res

115

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Subscribe to PCMR and stay up-to-date with the only journal committed to publishing basic research in melanoma and pigment cell biology As a member of the IFPCS or the SMR you automatically get online access to PCMR. Sign up as a member today at www.ifpcs.org or at www.societymelanomaresarch.org SummaryEumelanin is photoprotective while pheomelanin is phototoxic to pigmented tissues. Ultraviolet A (UVA)-induced tanning seems to result from the photooxidation of pre-existing melanin and contributes no photoprotection. However, data available for melanin biodegradation remain limited. In this study, we first examined photodegradation of eumelanin and pheomelanin in human black hairs and found that the ratio of Free (formed by peroxidation in situ) to Total (after hydrogen peroxide oxidation) pyrrole-2,3,5-tricarboxylic acid (PTCA) increases with hair aging, indicating fission of the dihydroxyindole moiety. In red hair, the ratio of thiazole-2,4,5-tricarboxylic acid (TTCA) to 4-amino-3-hydroxyphenylalanine (4-AHP) increases with aging, indicating the conversion from benzothiazine to benzothiazole moiety. These photodegradation of melanins were confirmed by UVA (not UVB) irradiation of melanins from mice and human hairs and synthetic eumelanin and pheomelanin. These results show that both eumelanin and pheomelanin degrade by UVA and that Free ⁄ Total PTCA and TTCA ⁄ 4-AHP ratios serve as sensitive indicators of photodegradation.

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Section: Significancementioning

confidence: 99%

UVA‐induced oxidative degradation of melanins: fission of indole moiety in eumelanin and conversion to benzothiazole moiety in pheomelanin

Wakamatsu

Nakanishi

Miyazaki

et al. 2012

Pigment Cell Melanoma Res

115

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“…While hominins near the equator developed dark photoprotective melanin-rich pigmentation due to high ultraviolet (UV) radiation exposure, those settling in low-UVB (λ = 280-315 nm) environments developed depigmented skin with facultative pigmentation (tanning) to sustain the photosynthesis of vitamin D 3 . Melanin is thus a key factor in one of the most noticeable human polymorphisms: skin color.…”

Section: Introductionmentioning

confidence: 99%

“…[1] Humans lacking melanocytes (melanin-producing cells) in the ear and animals with albinism (a deficit or absence of melanin) display hearing conditions as in domestic cats with white fur and blue eyes, thus suggesting a biofunctional role of melanin beyond photoprotection. [2,3] In the melanin biopigments family, eumelanin is a brownblack type found in the human body, other mammals, reptiles, amphibians, and fishes as well as in invertebrates, such as cuttlefish and insects; Sepia melanin is a type of natural eumelanin extracted from the ink sac of cuttlefish. Pheomelanin is a yellowish-red melanin.…”

Section: Introductionmentioning

confidence: 99%

Natural melanin pigments and their interfaces with metal ions and oxides: emerging concepts and technologies

Mauro

Soliveri

et al. 2017

MRS Communications

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Melanin (from the Greek μέλας, mélas, black) is a biopigment ubiquitous in flora and fauna, featuring broadband optical absorption, hydration-dependent electrical response, ion-binding affinity as well as antioxidative and radical-scavenging properties. In the human body, photoprotection in the skin and ion flux regulation in the brain are some biofunctional roles played by melanin. Here we discuss the progress in melanin research that underpins emerging technologies in energy storage/conversion, ion separation/water treatment, sunscreens, and bioelectronics. The melanin research aims at developing approaches to explore natural materials, well beyond melanin, which might serve as a prototype benign material for sustainable technologies.

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“…The disorders and relationship are discussed in detail in several contemporary textbooks [1][2][3][4][5] . Our concern, which led us to put forward a hypothesis 6,7 , is that too much attention is given to the influence of sunlight, which in evolutionary terms became well used when man became hairless and more exposed.…”

Section: Disorders Of Pigmentationmentioning

confidence: 99%

Disorders of Pigmentation of the Skin - Hypotheses Underlying Interventions by Multiple Systems of Medicine:Is there a Role for Integrated Medicine?

Arianayagam

Ryan

2016

Current Science

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Biomedicine has not provided a complete explanation with fully effective therapies for disorders of pigmentation. Biomedicine emphasizes the role of melanocyte for protection from UV rays and as a determinant of skin colour. These important properties acquired a genetic basis much later than other functions, many relating to cell contact as in the keratinocyte -melanocyte unit, or as with the synapses of the neurological system. There are other roles, biochemical and mechanical, of melanocyte. Management that is inclusive of a maximally holistic approach justifies the use of diverse herbals, yoga and concern for cultural awareness provided by integrated medicine. Vitiligo provides a model which demonstrates that Ayurveda has a richer view of its presentations, possibly a stronger line on its pathogenesis, and a huge range of herbals, many now backed by studies from ethnobotanical laboratories, awaiting research into the many possible mechanisms by which they may act in the wide and complex field of melanocyte biochemistry.

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Physiological and Pathological Functions of Melanosomes

Cited by 50 publications

References 153 publications

UVA‐induced oxidative degradation of melanins: fission of indole moiety in eumelanin and conversion to benzothiazole moiety in pheomelanin

UVA‐induced oxidative degradation of melanins: fission of indole moiety in eumelanin and conversion to benzothiazole moiety in pheomelanin

Natural melanin pigments and their interfaces with metal ions and oxides: emerging concepts and technologies

Disorders of Pigmentation of the Skin - Hypotheses Underlying Interventions by Multiple Systems of Medicine:Is there a Role for Integrated Medicine?

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