Regional patterning and regulation of melanin pigmentation in insects

The present study was conducted on ten each uropygial glands of 6 to 8 months old healthy Kadaknath and White Leghorn breeds of poultry. The tissue samples were stained by H and E for normal histological structures, Verhoeff’s stain for collagen and elastic fibers, PAS (Periodic Acid Schiff’s) for glycogen and Alcian Blue PAS method for acid mucopolysaccharides. The uropygial gland in Kadaknath and White Leghorn was composed of two lobes. Each lobe had a single duct and these ducts were joined together by isthmus. The thickness of capsule was more in White Leghorn than Kadaknath breed. The lumen of tubules showed higher concentration of secretary product in Kadaknath breed. Numbers of tubules were higher in Kadaknath. No aggregation of lymphocytes was found in the preen gland of White Leghorn, whereas in Kadaknath, there was large number of lymphocytes aggregation alongwith lymphatic nodules. Melanin pigmentation was the characteristic feature of Kadaknath which was found towards the central cavity and in between ductules. The capsule of White Leghorn showed intense PAS activity, while moderate activity was found in Kadaknath breed of poultry. Intense ACPase reaction was noticed in capsule of uropygial gland of Kadaknath and White Leghorn breeds of poultry.

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Distribution of Melanin Pigmentation in 33 Organs of Thai Black-Bone Chickens (Gallus gallus domesticus)

Animals ◽

10.3390/ani10050777 ◽

2020 ◽

Vol 10 (5) ◽

pp. 777

Author(s):

Korakot Nganvongpanit ◽

Piyatida Kaewkumpai ◽

Varankpicha Kochagul ◽

Kidsadagon Pringproa ◽

Veerasak Punyapornwithaya ◽

...

Keyword(s):

Gallus Gallus ◽

Gallus Domesticus ◽

Melanin Pigment ◽

Gallus Gallus Domesticus ◽

Tissue Samples ◽

Melanin Pigmentation ◽

Chicken Breed ◽

Brachial Vein ◽

The Brain ◽

Pigment Accumulation

The black-bone chicken (Gallus gallus domesticus) is a breed of chicken that is commonly found in Thailand. This breed is known for having a number of black colored organs. Consumers have been notably attracted to the black-bone chicken breed for the characteristic darkness that is observed in many of its organs. However, the degree of darkness in all organs of the black-bone chicken is still in question. Importantly, there have not yet been any published reports on the distribution of melanin pigment in the organs of the black-bone chicken. This research study aims to examine the distribution of the melanin pigment in 33 organs of the Thai black-bone chicken. Ten black-bone chickens (five male, five female) were included in this study. Thirty-two organs including the brain, spinal cord, sciatic nerve, larynx, trachea, syrinx, lungs, heart, pericardium, aorta, brachial vein, kidney, cloaca, oviduct, testis, gastrocnemius muscle, femur, tongue, esophagus, crop, proventriculus, gizzard, duodenum, jejunum, ileum, cecum, pancreas, liver, gall bladder, omentum, abdominal fat, spleen, and skin were examined in this study. Histological sections taken from tissue samples of each of these organs were studied. The findings revealed that the presence of the melanin pigment was not significantly different (p > 0.005) between male and female specimens. Notably, the liver was the only organ in which the melanin pigment had not accumulated. Consequently, there was not a uniform pattern of melanin pigment accumulation throughout the organs of the chickens. The melanin pigment was present in all of the tissue layers of most organs, while the melanin pigment was found in only specific layers of some of the organs. In conclusion, the distribution of melanin pigmentation in the organs of each of the animals in this study was found to be different. However, in some tissue samples, such as those obtained from the liver, no accumulation of the melanin pigment was observed.

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Genome-wide association study in almost 195,000 individuals identifies 50 previously unidentified genetic loci for eye color

Science Advances ◽

10.1126/sciadv.abd1239 ◽

2021 ◽

Vol 7 (11) ◽

pp. eabd1239

Author(s):

Mark Simcoe ◽

Ana Valdes ◽

Fan Liu ◽

Nicholas A. Furlotte ◽

David M. Evans ◽

...

Keyword(s):

Association Study ◽

Genome Wide Association Study ◽

Color Variation ◽

Genome Wide Association ◽

Nucleotide Polymorphisms ◽

Melanin Pigmentation ◽

Eye Color ◽

Human Eye ◽

Genome Wide ◽

Genomic Regions

Human eye color is highly heritable, but its genetic architecture is not yet fully understood. We report the results of the largest genome-wide association study for eye color to date, involving up to 192,986 European participants from 10 populations. We identify 124 independent associations arising from 61 discrete genomic regions, including 50 previously unidentified. We find evidence for genes involved in melanin pigmentation, but we also find associations with genes involved in iris morphology and structure. Further analyses in 1636 Asian participants from two populations suggest that iris pigmentation variation in Asians is genetically similar to Europeans, albeit with smaller effect sizes. Our findings collectively explain 53.2% (95% confidence interval, 45.4 to 61.0%) of eye color variation using common single-nucleotide polymorphisms. Overall, our study outcomes demonstrate that the genetic complexity of human eye color considerably exceeds previous knowledge and expectations, highlighting eye color as a genetically highly complex human trait.

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Marliolide Derivative Induces Melanosome Degradation via Nrf2/p62-Mediated Autophagy

International Journal of Molecular Sciences ◽

10.3390/ijms22083995 ◽

2021 ◽

Vol 22 (8) ◽

pp. 3995

Author(s):

Cheong-Yong Yun ◽

Nahyun Choi ◽

Jae Un Lee ◽

Eun Jung Lee ◽

Ji Young Kim ◽

...

Keyword(s):

Related Factor ◽

Melanin Pigmentation ◽

Microtubule Associated Proteins ◽

Melanocyte Stimulating Hormone ◽

Associated Proteins ◽

Autophagy Pathway ◽

Nrf2 Activator ◽

Promising Therapeutic Agent

Nuclear factor erythroid 2-related factor 2 (Nrf2), which is linked to autophagy regulation and melanogenesis regulation, is activated by marliolide. In this study, we investigated the effect of a marliolide derivative on melanosome degradation through the autophagy pathway. The effect of the marliolide derivative on melanosome degradation was investigated in α-melanocyte stimulating hormone (α-MSH)-treated melanocytes, melanosome-incorporated keratinocyte, and ultraviolet (UV)B-exposed HRM-2 mice (melanin-possessing hairless mice). The marliolide derivative, 5-methyl-3-tetradecylidene-dihydro-furan-2-one (DMF02), decreased melanin pigmentation by melanosome degradation in α-MSH-treated melanocytes and melanosome-incorporated keratinocytes, evidenced by premelanosome protein (PMEL) expression, but did not affect melanogenesis-associated proteins. The UVB-induced hyperpigmentation in HRM-2 mice was also reduced by a topical application of DMF02. DMF02 activated Nrf2 and induced autophagy in vivo, evidenced by decreased PMEL in microtubule-associated proteins 1A/1B light chain 3B (LC3)-II-expressed areas. DMF02 also induced melanosome degradation via autophagy in vitro, and DMF02-induced melanosome degradation was recovered by chloroquine (CQ), which is a lysosomal inhibitor. In addition, Nrf2 silencing by siRNA attenuated the DMF02-induced melanosome degradation via the suppression of p62. DMF02 induced melanosome degradation in melanocytes and keratinocytes by regulating autophagy via Nrf2-p62 activation. Therefore, Nrf2 activator could be a promising therapeutic agent for reducing hyperpigmentation.

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Hormonal control of melanin pigmentation in scrotal skin of the rat

Experimental Cell Research ◽

10.1016/0014-4827(66)90408-3 ◽

1966 ◽

Vol 44 (1) ◽

pp. 13-22 ◽

Cited By ~ 9

Author(s):

T.M. Mills ◽

E. Spaziani

Keyword(s):

Hormonal Control ◽

Scrotal Skin ◽

Melanin Pigmentation

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The Anti-Ageing and Whitening Potential of a Cosmetic Serum Containing 3-O-ethyl-l-ascorbic Acid

Life ◽

10.3390/life11050406 ◽

2021 ◽

Vol 11 (5) ◽

pp. 406

Author(s):

Nicola Zerbinati ◽

Sabrina Sommatis ◽

Cristina Maccario ◽

Serena Di Francesco ◽

Maria Chiara Capillo ◽

...

Keyword(s):

Ascorbic Acid ◽

Dermal Fibroblasts ◽

Melanin Content ◽

Dna Protection ◽

Melanin Pigmentation ◽

Intrinsic Factors ◽

Reconstructed Human Epidermis ◽

Solar Ultraviolet ◽

Damage Marker ◽

Extrinsic And Intrinsic Factors

Skin ageing has many manifestations such as wrinkles, dryness, hyperpigmentation, and uneven skin tone. Extrinsic and intrinsic factors, especially solar ultraviolet light (UVB), contribute to skin ageing; its main features are brown spots, alterations in melanin pigmentation, and a decrease in collagen and hyaluronic acid linked to oxidative stress. Several studies showed that topical products containing ingredients with antioxidant activity can reduce oxidative damage; to provide a maximum anti-ageing effect to the skin, topical products can combine various ingredients. C-SHOT SERUM contains a combination of two molecules with a proven anti-ageing activity: a high percentage (30%) of a more stable vitamin C derivative, 3-O-ethyl-l-ascorbic acid, and lactic acid (1%). The product showed a high biocompatibility, assessed through an MTT assay on keratinocytes and on Reconstructed Human Epidermis (RHE, SkinEthic); the anti-ageing activity was demonstrated on human dermal fibroblasts and keratinocytes by a statistically significant increase in collagen production and a reduction of a UVB-induced DNA damage marker (γ-H2AX histone), indicating DNA protection. Moreover, a depigmenting activity, shown by a highly significant decrease in melanin content on treated Reconstructed Human Pigmented Epidermis (RHPE), was assessed. According to the data of our study, the tested product contrasts the effect of skin ageing and irregular pigmentation due to the physiological decline of the skin.

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ACTH AND MELANIN PIGMENTATION.

British Journal of Dermatology ◽

10.1111/j.1365-2133.1954.tb12567.x ◽

1954 ◽

Vol 66 (11) ◽

pp. 388-401 ◽

Cited By ~ 5

Author(s):

F. A. WHITLOCK ◽

M.D. Cantab ◽

M.R.C.P. Lond

Keyword(s):

Melanin Pigmentation

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Fractional carbon dioxide laser, platelet –rich plasma and narrow band ultraviolet B in the treatment of Vitiligo (A prospective randomized comparative trial)

QJM ◽

10.1093/qjmed/hcab093.025 ◽

2021 ◽

Vol 114 (Supplement_1) ◽

Author(s):

Mohamed Abdullah Eshafi ◽

Nehal Mohamed Zuelfakkar ◽

Ahmed Abd Elfattah Afify

Keyword(s):

Patient Satisfaction ◽

Co2 Laser ◽

Platelet Rich Plasma ◽

Ultraviolet B ◽

Treatment Modalities ◽

Computer Assisted ◽

Triple Combination ◽

Patient Satisfaction Score ◽

Triple Combination Therapy ◽

Melanin Pigmentation

Abstract Vitiligo is a disease that causes the loss of skin color in patches due to loss of melanin pigmentation of specific areas of the skin. Although several hypotheses have been proposed, the leading theory is still the auto-immune etiology linked to specific genetic mutations. Vitiligo can also be associated with several autoimmune diseases. There is no curative treatment for vitiligo but, several treatment modalities are considered. Topical therapies like steroids and Calcineurin inhibitors are of popular use in clinical settings also, steroids can be administered systemically in vitiligo patients. Physical therapies as fractionated CO2 (Fr: CO2) laser and Narrowband-UV (NBUV) phototherapy represent a gold standard in treatment in clinical practice. Moreover, intralesional therapies are emerging, one of which is autologous platelet-rich plasma injection. Aim of the study This study aimed to evaluate and compare the efficacy and safety of Fr: CO2 laser, PRP, combined Fr: CO2 laser and PRP, combined Fr: CO2 laser and NB-UVB, combined Fr: CO2 laser, PRP and NB-UVB in the treatment of vitiligo as well as reporting the side effects. Patients and methods This study included 20 vitiligo patients with at least 6 patches of stable vitiligo (120 patches), the patches were divided into six groups according to the treatment modality. Assessment of treatment response was done through patient satisfaction score and Vitiligo analysis by computer-assisted grid (VACAG). Results Regarding surface area reduction in included patients, fractional CO2 laser achieved the best results followed by triple combination therapy (CO2 with PRP and NB-UVB), the least response was with CO2 with PRP treatment. Patient satisfaction in the current study had a different outcome, PRP treated patients exhibited the highest satisfaction scores while triple combination treated group showed the least satisfaction scores.

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