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Indian Pediatrics Apr 2024
Topics: Animals; Humans; Pigmentation; Heteroptera
PubMed: 38419280
DOI: No ID Found -
Cutis Mar 2024
Topics: Humans; Skin Pigmentation
PubMed: 38648586
DOI: 10.12788/cutis.0972 -
Anais Brasileiros de Dermatologia 2024The vast majority of publications in dermatology refer to lightly pigmented skin, with few addressing the peculiarities of black skin. In addition there is no consensus... (Review)
Review
The vast majority of publications in dermatology refer to lightly pigmented skin, with few addressing the peculiarities of black skin. In addition there is no consensus on what it means to be black in different regions of the world. The lack of knowledge on the subject makes it difficult to recognize and manage dermatoses in this type of skin. This article aims to review the literature on intrinsic characteristics, as well as epidemiological and clinical aspects of the cutaneous manifestations of different dermatoses in black skin. It was found that there are sometimes striking differences, in the structural, biological, and functional aspects when comparing lightly pigmented and black skin. There are also physiological changes that need to be recognized to avoid unnecessary interventions. Some dermatoses have a higher incidence in black skin, such as acne, eczema, dyschromia and dermatophytosis. On the other hand, several dermatoses are more specific to black skin, such as pseudofolliculitis barbae, keloid, dermatosis papulosa nigra, ulcers caused by sickle-cell anemia, dactylolysis spontanea, confluent and reticulated papillomatosis of Gougerot and Carteaud, and some diseases of the hair and scalp (including fragile and brittle hair, traction alopecia, folliculitis keloidalis nuchae, folliculitis dissecans and central centrifugal cicatricial alopecia). A spectrum of peculiar aspects of specific dermatoses, including sarcoidosis, lichen planus (with emphasis on the pigmentosus variant), psoriasis, lupus erythematosus, vitiligo, syphilis, pityriasis versicolor, and neoplasms are highlighted. In the latter, characteristics of basal cell carcinoma, squamous cell carcinoma, and melanoma are compared, in addition to highlighting unusual aspects of primary cutaneous T-cell lymphoma, endemic Kaposi sarcoma, and dermatofibrosarcoma protuberans.
Topics: Humans; Skin Diseases; Skin Pigmentation; Skin; Black People
PubMed: 38310012
DOI: 10.1016/j.abd.2023.10.001 -
International Journal of Molecular... Jun 2024The skin-brain axis has been suggested to play a role in several pathophysiological conditions, including opioid addiction, Parkinson's disease and many others. Recent... (Review)
Review
The skin-brain axis has been suggested to play a role in several pathophysiological conditions, including opioid addiction, Parkinson's disease and many others. Recent evidence suggests that pathways regulating skin pigmentation may directly and indirectly regulate behaviour. Conversely, CNS-driven neural and hormonal responses have been demonstrated to regulate pigmentation, e.g., under stress. Additionally, due to the shared neuroectodermal origins of the melanocytes and neurons in the CNS, certain CNS diseases may be linked to pigmentation-related changes due to common regulators, e.g., MC1R variations. Furthermore, the HPA analogue of the skin connects skin pigmentation to the endocrine system, thereby allowing the skin to index possible hormonal abnormalities visibly. In this review, insight is provided into skin pigment production and neuromelanin synthesis in the brain and recent findings are summarised on how signalling pathways in the skin, with a particular focus on pigmentation, are interconnected with the central nervous system. Thus, this review may supply a better understanding of the mechanism of several skin-brain associations in health and disease.
Topics: Humans; Skin Pigmentation; Brain; Animals; Skin; Ultraviolet Rays; Melanins; Signal Transduction; Behavior
PubMed: 38892387
DOI: 10.3390/ijms25116199 -
International Journal of Dermatology Sep 2023
Topics: Humans; Friction; Nail Diseases; Nails; Pigmentation
PubMed: 36683209
DOI: 10.1111/ijd.16601 -
EMBO Reports Jul 2023Dysregulation of the activity of the mechanistic target of rapamycin complex 1 (mTORC1) is commonly linked to aging, cancer, and genetic disorders such as tuberous...
Dysregulation of the activity of the mechanistic target of rapamycin complex 1 (mTORC1) is commonly linked to aging, cancer, and genetic disorders such as tuberous sclerosis (TS), a rare neurodevelopmental multisystemic disease characterized by benign tumors, seizures, and intellectual disability. Although patches of white hair on the scalp (poliosis) are considered as early signs of TS, the underlying molecular mechanisms and potential involvement of mTORC1 in hair depigmentation remain unclear. Here, we have used healthy, organ-cultured human scalp hair follicles (HFs) to interrogate the role of mTORC1 in a prototypic human (mini-)organ. Gray/white HFs exhibit high mTORC1 activity, while mTORC1 inhibition by rapamycin stimulated HF growth and pigmentation, even in gray/white HFs that still contained some surviving melanocytes. Mechanistically, this occurred via increased intrafollicular production of the melanotropic hormone, α-MSH. In contrast, knockdown of intrafollicular TSC2, a negative regulator of mTORC1, significantly reduced HF pigmentation. Our findings introduce mTORC1 activity as an important negative regulator of human HF growth and pigmentation and suggest that pharmacological mTORC1 inhibition could become a novel strategy in the management of hair loss and depigmentation disorders.
Topics: Humans; Hair Follicle; Mechanistic Target of Rapamycin Complex 1; Pigmentation; Melanocytes; Hair Color
PubMed: 37212043
DOI: 10.15252/embr.202256574 -
The Pan African Medical Journal 2024
Topics: Humans; Clofazimine; Female; Skin Pigmentation; Male; Hyperpigmentation; Leprostatic Agents; Adult; Middle Aged
PubMed: 38737223
DOI: 10.11604/pamj.2024.47.86.42513 -
International Journal of Molecular... Jul 2023Melanocortins play crucial roles in regulating the stress response, inflammation, and skin pigmentation. In this review, we focus on the melanocortin 1 receptor (MC1R),... (Review)
Review
Melanocortins play crucial roles in regulating the stress response, inflammation, and skin pigmentation. In this review, we focus on the melanocortin 1 receptor (MC1R), a G protein-coupled receptor primarily known for regulating skin pigmentation and exhibiting anti-inflammatory effects. First, we provide an overview of the structure, signaling pathways, and related diseases of MC1R. Next, we discuss the potential therapeutic use of synthetic peptides and small molecule modulators of MC1R, highlighting the development of various drugs that enhance stability through amino acid sequence modifications and small molecule drugs to overcome limitations associated with peptide characteristics. Notably, MC1R-targeted drugs have applications beyond skin pigmentation-related diseases, which predominantly affect MC1R in melanocytes. These drugs can also be useful in treating inflammatory diseases with MC1R expression present in various cells. Our review underscores the potential of MC1R-targeted drugs to treat a wide range of diseases and encourages further research in this area.
Topics: Melanocytes; Peptides; Receptor, Melanocortin, Type 1; Signal Transduction; Skin Pigmentation; Humans
PubMed: 37569558
DOI: 10.3390/ijms241512152 -
Bio Systems Aug 2023We have reviewed and interpreted the thermodynamic principles for flower pigmentation. The basic thoughts are as follows: 1) any biological trait is associated with one...
We have reviewed and interpreted the thermodynamic principles for flower pigmentation. The basic thoughts are as follows: 1) any biological trait is associated with one thermodynamic system; 2) a thermodynamic system of biology cannot be physically isolated from complex thermal systems of biology but can be separately studied using thermodynamic methods; 3) a thermodynamic system of biology has all types of information, including volume, shape, and structure, unlike the traditional thermal system of gases; 4) a thermodynamic system of biology is associated with one type of biological structure that is not fully fixed but can change its conformation under different conditions; and 5) a thermodynamic system of biology shows a hierarchical structure. On the basis of these principles, several conclusions regarding flower pigmentation are obtained as follows: 1) processes of pigmentation formation can be divided into reversible and irreversible processes; 2) the reversible process is related to quantitative changes in pigments; 3) the irreversible process is related to the formation of stable pigmentation patterns that are physiologically inherited; 4) the spot pattern of color pigmentation represents an independent island of the physiological system; 5) many types of activators and inhibitors are involved in flower pigmentation production; 6) the patterns of flower pigmentation can be modulated; and 7) the evolution mechanism of organogenesis can be separated into several steps of independent thermodynamic processes. Our conclusion is that the thermodynamic system, rather than the dynamic system, is the essential and fundamental attribute of biological behaviors.
Topics: Pigmentation; Flowers; Phenotype; Thermodynamics
PubMed: 37277021
DOI: 10.1016/j.biosystems.2023.104938 -
Ageing Research Reviews Nov 2023Aging is a complex natural process that leads to a decline in physiological functions, which is visible in signs such as hair graying, thinning, and loss. Although hair... (Review)
Review
Aging is a complex natural process that leads to a decline in physiological functions, which is visible in signs such as hair graying, thinning, and loss. Although hair graying is characterized by a loss of pigment in the hair shaft, the underlying mechanism of age-associated hair graying is not fully understood. Hair graying and loss can have a significant impact on an individual's self-esteem and self-confidence, potentially leading to mental health problems such as depression and anxiety. Omics technologies, which have applications beyond clinical medicine, have led to the discovery of candidate hair biomarkers and may provide insight into the complex biology of hair aging and identify targets for effective therapies. This review provides an up-to-date overview of recent omics discoveries, including age-associated alterations of proteins and metabolites in the hair shaft and follicle, and highlights the significance of hair aging and graying biomarker discoveries. The decline in hair follicle stem cell activity with aging decreased the regeneration capacity of hair follicles. Cellular senescence, oxidative damage and altered extracellular matrix of hair follicle constituents characterized hair follicle and hair shaft aging and graying. The review attempts to correlate the impact of endogenous and exogenous factors on hair aging. We close by discussing the main challenges and limitations of the field, defining major open questions and offering an outlook for future research.
Topics: Humans; Hair Color; Aging; Hair; Biomarkers; Biology
PubMed: 37634889
DOI: 10.1016/j.arr.2023.102041