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Medicinal Research Reviews Mar 2021Vitiligo is an autoimmune depigment disease results from extensive melanocytes destruction. The destruction of melanocyte is thought to be of multifactorial causation.... (Review)
Review
Vitiligo is an autoimmune depigment disease results from extensive melanocytes destruction. The destruction of melanocyte is thought to be of multifactorial causation. Genome-wide associated studies have identified single-nucleotide polymorphisms in a panel of susceptible loci as risk factors in melanocyte death. But vitiligo onset can't be solely attributed to a susceptive genetic background. Oxidative stress triggered by elevated levels of reactive oxygen species accounts for melanocytic molecular and organelle dysfunction, a minority of melanocyte demise, and melanocyte-specific antigens exposure. Of note, the self-responsive immune function directly contributes to the bulk of melanocyte deaths in vitiligo. The aberrantly heightened innate immunity, type-1-skewed T helper, and incompetent regulatory T cells tip the balance toward autoreaction and CD8 cytotoxic T lymphocytes finally execute the killing of melanocytes, possibly alarmed by resident memory T cells. In addition to the well-established apoptosis and necrosis, we discuss several death modalities like oxeiptosis, ferroptosis, and necroptosis that are probably employed in melanocyte destruction. This review focuses on the various mechanisms of melanocytic death in vitiligo pathogenesis to demonstrate a panorama of that. We hope to provide new insights into vitiligo pathogenesis and treatment strategies by the review.
Topics: Apoptosis; CD8-Positive T-Lymphocytes; Humans; Melanocytes; Oxidative Stress; Vitiligo
PubMed: 33200838
DOI: 10.1002/med.21754 -
Anais Brasileiros de Dermatologia 2022Vitiligo is a complex disease whose pathogenesis results from the interaction of genetic components, metabolic factors linked to cellular oxidative stress, melanocyte... (Review)
Review
Vitiligo is a complex disease whose pathogenesis results from the interaction of genetic components, metabolic factors linked to cellular oxidative stress, melanocyte adhesion to the epithelium, and immunity (innate and adaptive), which culminate in aggression against melanocytes. In vitiligo, melanocytes are more sensitive to oxidative damage, leading to the increased expression of proinflammatory proteins such as HSP70. The lower expression of epithelial adhesion molecules, such as DDR1 and E-cadherin, facilitates damage to melanocytes and exposure of antigens that favor autoimmunity. Activation of the type 1-IFN pathway perpetuates the direct action of CD8+ cells against melanocytes, facilitated by regulatory T-cell dysfunction. The identification of several genes involved in these processes sets the stage for disease development and maintenance. However, the relationship of vitiligo with environmental factors, psychological stress, comorbidities, and the elements that define individual susceptibility to the disease are a challenge to the integration of theories related to its pathogenesis.
Topics: Autoimmunity; Humans; Melanocytes; Oxidative Stress; Vitiligo
PubMed: 35643735
DOI: 10.1016/j.abd.2021.09.008 -
Development (Cambridge, England) Feb 2015Melanocyte development provides an excellent model for studying more complex developmental processes. Melanocytes have an apparently simple aetiology, differentiating... (Review)
Review
Melanocyte development provides an excellent model for studying more complex developmental processes. Melanocytes have an apparently simple aetiology, differentiating from the neural crest and migrating through the developing embryo to specific locations within the skin and hair follicles, and to other sites in the body. The study of pigmentation mutations in the mouse provided the initial key to identifying the genes and proteins involved in melanocyte development. In addition, work on chicken has provided important embryological and molecular insights, whereas studies in zebrafish have allowed live imaging as well as genetic and transgenic approaches. This cross-species approach is powerful and, as we review here, has resulted in a detailed understanding of melanocyte development and differentiation, melanocyte stem cells and the role of the melanocyte lineage in diseases such as melanoma.
Topics: Animals; Humans; Melanocytes; Melanoma; Microphthalmia-Associated Transcription Factor; Neural Crest; Stem Cells
PubMed: 25670789
DOI: 10.1242/dev.106567 -
Frontiers in Immunology 2021Vitiligo is a disease of the skin characterized by the appearance of white spots. Significant progress has been made in understanding vitiligo pathogenesis over the past... (Review)
Review
Vitiligo is a disease of the skin characterized by the appearance of white spots. Significant progress has been made in understanding vitiligo pathogenesis over the past 30 years, but only through perseverance, collaboration, and open-minded discussion. Early hypotheses considered roles for innervation, microvascular anomalies, oxidative stress, defects in melanocyte adhesion, autoimmunity, somatic mosaicism, and genetics. Because theories about pathogenesis drive experimental design, focus, and even therapeutic approach, it is important to consider their impact on our current understanding about vitiligo. Animal models allow researchers to perform mechanistic studies, and the development of improved patient sample collection methods provides a platform for translational studies in vitiligo that can also be applied to understand other autoimmune diseases that are more difficult to study in human samples. Here we discuss the history of vitiligo translational research, recent advances, and their implications for new treatment approaches.
Topics: Animals; Autoimmunity; Dermatologic Agents; Disease Models, Animal; Genetic Testing; Humans; Melanocytes; Oxidative Stress; Phenotype; Skin; Skin Pigmentation; Translational Research, Biomedical; Vitiligo
PubMed: 33737930
DOI: 10.3389/fimmu.2021.624517 -
International Journal of Molecular... Mar 2023Vitiligo is an acquired hypopigmentation of the skin due to a progressive selective loss of melanocytes; it has a prevalence of 1-2% and appears as rounded,... (Review)
Review
Vitiligo is an acquired hypopigmentation of the skin due to a progressive selective loss of melanocytes; it has a prevalence of 1-2% and appears as rounded, well-demarcated white macules. The etiopathology of the disease has not been well defined, but multiple factors contribute to melanocyte loss: metabolic abnormalities, oxidative stress, inflammation, and autoimmunity. Therefore, a convergence theory was proposed that combines all existing theories into a comprehensive one in which several mechanisms contribute to the reduction of melanocyte viability. In addition, increasingly in-depth knowledge about the disease's pathogenetic processes has enabled the development of increasingly targeted therapeutic strategies with high efficacy and fewer side effects. The aim of this paper is, by conducting a narrative review of the literature, to analyze the pathogenesis of vitiligo and the most recent treatments available for this condition.
Topics: Humans; Vitiligo; Hypopigmentation; Melanocytes; Skin; Oxidative Stress
PubMed: 36902341
DOI: 10.3390/ijms24054910 -
Theranostics 2023Senescent melanocytes accumulate in photoaged skin and are closely related to skin aging. A better understanding of the molecular characteristics of senescent...
Senescent melanocytes accumulate in photoaged skin and are closely related to skin aging. A better understanding of the molecular characteristics of senescent melanocytes may be the key to controlling skin aging. We have developed an model of senescence in melanocytes using UV irradiation and investigated the functional characteristics and molecular mechanisms underlying senescence in UV-irradiated melanocytes. We have highlighted that senescent melanocytes are characterized by melanosome transport dysfunction resulting in melanin accumulation. The defective melanosome transport was confirmed with the ultrastructural characterization of both UV-induced senescent melanocytes and melanocytes of hypopigmented aging skin. A single-cell transcriptomic analysis revealed that the glycolytic metabolism pathway appeared to be significantly upregulated in most senescent phenotypes. Furthermore, the inhibition of glycolysis by pharmacological compounds mitigates the pro-aging effects of melanocytes senescence, suggesting that alterations in cellular glucose metabolism act as a driving force for senescence in melanocytes. These results demonstrate that senescent melanocytes are characterized by glycolytic metabolism changes and a defective melanosome transport process, which may be related to impaired mitochondrial function, highlighting the importance of metabolic reprogramming in regulating melanocyte senescence.
Topics: Melanosomes; Melanocytes; Skin; Melanins; Glycolysis; Cellular Senescence
PubMed: 37554281
DOI: 10.7150/thno.84912 -
Ageing Research Reviews Aug 2023Hair graying is an early and obvious phenotypic and physiological trait with age in humans. Several recent advances in molecular biology and genetics have increased our... (Review)
Review
Hair graying is an early and obvious phenotypic and physiological trait with age in humans. Several recent advances in molecular biology and genetics have increased our understanding of the mechanisms of hair graying, which elucidate genes related to the synthesis, transport, and distribution of melanin in hair follicles, as well as genes regulating these processes above. Therefore, we review these advances and examine the trends in the genetic aspects of hair graying from enrichment theory, Genome-Wide association studies, whole exome sequencing, gene expression studies, and animal models for hair graying with age, aiming to overview the changes in hair graying at the genetic level and establish the foundation for future research. Meanwhile, by summarizing the genetics, it's of great value to explore the possible mechanism, treatment, or even prevention of hair graying with age.
Topics: Animals; Humans; Aging; Hair Color; Genome-Wide Association Study; Melanocytes; Hair
PubMed: 37276979
DOI: 10.1016/j.arr.2023.101977 -
Autophagy Feb 2019Ultraviolet radiation (UVR)-induced skin pigmentation, afforded by the dark organelles termed melanosomes, accounts for the first-line protection against environmental...
Ultraviolet radiation (UVR)-induced skin pigmentation, afforded by the dark organelles termed melanosomes, accounts for the first-line protection against environmental UVR that increases the risk of developing skin cancers including melanoma. We have recently discovered that UVRAG, originally identified as a BECN1-binding macroautophagy/autophagy protein, appears to have a specialized function in melanosome biogenesis beyond autophagy through its interaction with the biogenesis of lysosome-related organelles complex 1 (BLOC-1). This melanogenic function of UVRAG is controlled by the melanocyte-specific transcription factor MITF as a downstream effector of the α-melanocyte-stimulating hormone (α-MSH)-cAMP signaling in the suntan response, which is compromised in BRAF mutant melanoma. Thus we propose a new mode of UVRAG activity and regulation in melanocyte biology that may affect melanoma predisposition.
Topics: Beclin-1; Humans; Melanins; Melanocytes; Melanosomes; Skin Pigmentation; Tumor Suppressor Proteins; Ultraviolet Rays
PubMed: 30209981
DOI: 10.1080/15548627.2018.1522911 -
Dermatologic Clinics Apr 2017The pathogenesis of vitiligo involves interplay between intrinsic and extrinsic melanocyte defects, innate immune inflammation, and T-cell-mediated melanocyte... (Review)
Review
The pathogenesis of vitiligo involves interplay between intrinsic and extrinsic melanocyte defects, innate immune inflammation, and T-cell-mediated melanocyte destruction. The goal of treatment is to not only halt disease progression but also promote repigmentation through melanocyte regeneration, proliferation, and migration. Treatment strategies that address all aspects of disease pathogenesis and repigmentation are likely to have greatest efficacy, a strategy that may require combination therapies. Current treatments generally involve nontargeted suppression of autoimmunity, whereas emerging treatments are likely to use a more targeted approach based on in-depth understanding of disease pathogenesis, which may provide higher efficacy with a good safety profile.
Topics: Adaptive Immunity; Antioxidants; Autoimmunity; Humans; Immunity, Innate; Immunosuppressive Agents; Melanocytes; Oxidative Stress; Phototherapy; Regeneration; Self Tolerance; T-Lymphocytes, Cytotoxic; Vitiligo
PubMed: 28317534
DOI: 10.1016/j.det.2016.11.014 -
Frontiers in Immunology 2021Vitiligo is an acquired multifactorial disease that affects melanocytes and results in skin depigmentation. In this review, we examine the role of cells stress and... (Review)
Review
Vitiligo is an acquired multifactorial disease that affects melanocytes and results in skin depigmentation. In this review, we examine the role of cells stress and self-reactive T cells responses. Given the canonical and non-canonical functions of NKG2D, such as authenticating stressed target and enhance TCR signaling, we examine how melanocyte stress leads to the expression of ligands that are recognized by the activating receptor NKG2D, and how its signaling results in the turning of T cells against self (melanocyte suicide by proxy). We also discuss how this initiation phase is followed by T cell perpetuation, as NKG2D signaling results in self-sustained long-lasting T cells, with improved cytolytic properties.
Topics: Animals; Autoimmunity; CD8-Positive T-Lymphocytes; Cellular Microenvironment; Cytotoxicity, Immunologic; Humans; Melanocytes; NK Cell Lectin-Like Receptor Subfamily K; Oxidative Stress; Signal Transduction; Skin; Skin Pigmentation; Vitiligo
PubMed: 33717132
DOI: 10.3389/fimmu.2021.624131