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The Journal of Investigative Dermatology Feb 2020Skin depigmentation diseases, such as vitiligo, are pigmentation disorders that often destroy melanocytes. However, their pathological mechanisms remain unclear, and...
Skin depigmentation diseases, such as vitiligo, are pigmentation disorders that often destroy melanocytes. However, their pathological mechanisms remain unclear, and therefore, promising treatments or prevention has been lacking. Here, we demonstrate that a zebrafish insertional mutant showing a significant reduction of nicastrin transcript possesses melanosome maturation defect, Tyrosinase-dependent mitochondrial swelling, and melanophore cell death. The depigmentation phenotypes are proven to be a result of γ-secretase inactivation. Furthermore, live imaging demonstrates that macrophages are recruited to and can phagocytose melanophore debris. Thus, we characterize a potential zebrafish depigmentation disease model, a nicastrin mutant, which can be used for further treatment or drug development of diseases related to skin depigmentation and/or inflammation.
Topics: Amyloid Precursor Protein Secretases; Animals; Animals, Genetically Modified; Disease Models, Animal; Embryo, Nonmammalian; Humans; Hypopigmentation; Melanosomes; Membrane Glycoproteins; Microscopy, Electron, Transmission; Monophenol Monooxygenase; Mutation; Skin; Skin Pigmentation; Zebrafish; Zebrafish Proteins
PubMed: 31437444
DOI: 10.1016/j.jid.2019.07.702 -
Developmental Dynamics : An Official... Sep 2006Mouse coat color mutations have a long history in biomedical research. The viable and visible phenotype of most coat color mutations has made the pigment cell, the... (Review)
Review
Mouse coat color mutations have a long history in biomedical research. The viable and visible phenotype of most coat color mutations has made the pigment cell, the melanocyte, an ideal system for genetic, molecular, and cellular analysis. Molecular cloning and analysis of many of the different coat color mutations have revealed the roles of a diverse range of genes, and today we know more about the pathways and proteins that regulate the development and function of pigment cells than we know about most other cell types in mammalian organisms. Coat color mutations have also provided novel insights into stem cell biology and human diseases, including melanoma. In the future, it will be important to build on this history and knowledge by taking advantage of the extensive repertoire of recently developed genome-wide methodologies, available genomic information, and the powerful methods that have been developed for modifying the mouse genome to systematically dissect the development and function of this important cell type. The usefulness of coat color mutations has just begun to emerge.
Topics: Animals; Cell Differentiation; Genomics; Hair Color; Melanocytes; Melanosomes; Mice; Mutation; Pigments, Biological; Skin Pigmentation; Stem Cells
PubMed: 16691561
DOI: 10.1002/dvdy.20840 -
Journal of Dermatological Science Jun 2022Keratinocytes are recipients of melanosomes. Although the chemical basis of melanogenesis is well documented, the molecular mechanism of melanosome transfer must be...
BACKGROUND
Keratinocytes are recipients of melanosomes. Although the chemical basis of melanogenesis is well documented, the molecular mechanism of melanosome transfer must be elucidated. TRPA1 is a member of the transient receptor potential A subfamily. Previous studies have shown that inhibition of TRPA1 activity reduces melanin synthesis in human epidermal melanocytes; however, the mechanism remains unknown.
OBJECTIVE
This study aimed to investigate the roles and mechanism(s) of action of TRPA1 in keratinocytes.
METHODS
The correlation between TRPA1 expression levels and the ability of keratinocytes to phagocytize melanosomes was examined using melanin silver staining. TRPA1 depleted human epidermal keratinocytes and keratinocyte cell lines HaCaT were established using adenovirus-expressing shRNAs against TRPA1. The effects of TRPA1 on keratinocytes and HaCaT cells were determined using cell-based analyses, including light stimulation, calcium imaging, melanin phagocytosis, immunoblotting, and co-immunoprecipitation assays. The degree of epidermal pigmentation was determined in a guinea pig model.
RESULTS
TRPA1 mediated the phagocytic activity of keratinocytes. TRPA1 knockdown markedly suppressed melanosome transport to keratinocytes. Mechanistically, TRPA1 was required for PAR-2-induced melanosome phagocytosis in keratinocytes. Furthermore, TRPA1 activation indirectly stabilized microtubules by promoting the competitive binding of CYLD and acetylated α-tubulin. In addition, bortezomib (PS-341), a proteasome inhibitor, increased TRPA1 and CYLD expression and promoted phagocytic activity both in vitro and in vivo.
CONCLUSIONS
Our findings firstly suggest that TRPA1 promotes melanosome transport in keratinocytes and reveal that TRPA1 is a regulator of PAR-2 activation and microtubule stability via the PAR-2/CYLD axis.
Topics: Animals; Guinea Pigs; Keratinocytes; Melanins; Melanocytes; Melanosomes; Phagocytosis
PubMed: 35637111
DOI: 10.1016/j.jdermsci.2022.05.005 -
Aging Dec 2020α-MSH is known for melanogenesis stimulation, and ceRNA is a new method involved in physiological regulation. However, whether ceRNA participates in α-MSH-induced...
α-MSH is known for melanogenesis stimulation, and ceRNA is a new method involved in physiological regulation. However, whether ceRNA participates in α-MSH-induced melanogenesis remains unknown. We used ceRNA array to detect the expression profiles of lncRNAs, circRNAs, and mRNAs in melanocytes after α-MSH treatment. Moreover, the melanogenesis-related ceRNA regulatory networks were screened and validated. The expression profile analysis showed that 20 lncRNAs and 49 circRNAs changed five-fold after α-MSH treatment, while 933 mRNAs changed two-fold. Based on differentially expressed genes, GO and KEGG analysis were conducted and revealed that 14 genes were enriched in melanogenesis. Then, multiple lncRNA or circRNA-miRNA-mRNA ceRNA networks and lncRNA/circRNA-miRNA-mRNA quaternary ceRNA networks were identified. Thereinto, ENST00000606533, circ_0091223, and TYR expression were upregulated in α-MSH-treated melanocytes, while their complementary miR-1291 was decreased. Dual-luciferase reporter assay further verified that ENST00000606533 and circ_0091223 could bind to miR-1291. ENST00000606533 and circ_0091223 siRNAs decreased circ_0091223, ENST00000606533, and TYR expression, but increased miR-1291 expression. Conversely, miR-1291 mimics inhibited ENST00000606533, circ_0091223, and TYR expression. Moreover, miR-1291 inhibitor could reverse the inhibitory effect of the two siRNAs on TYR expression. Hence, the "ENST00000606533/circ_0091223-miR-1291-TYR" ceRNA network is involved in α-MSH-induced melanogenesis, and ceRNA networks may be potential therapeutic targets for skin pigmentation disorders.
Topics: Gene Regulatory Networks; Hormones; Humans; In Vitro Techniques; Melanins; Melanocytes; Melanosomes; MicroRNAs; Pigmentation; RNA, Circular; RNA, Long Noncoding; RNA, Messenger; alpha-MSH
PubMed: 33318297
DOI: 10.18632/aging.202320 -
Cells Mar 2021Zebrafish has emerged as a powerful model in studies dealing with pigment development and pathobiology of pigment diseases. Due to its conserved pigment pattern with...
Zebrafish has emerged as a powerful model in studies dealing with pigment development and pathobiology of pigment diseases. Due to its conserved pigment pattern with established genetic background, the zebrafish is used for screening of active compounds influencing melanophore, iridophore, and xanthophore development and differentiation. In our study, zebrafish embryos and larvae were used to investigate the influence of third-generation noncompetitive P-glycoprotein inhibitor, tariquidar (TQR), on pigmentation, including phenotype effects and changes in gene expression of chosen chromatophore differentiation markers. Five-day exposure to increasing TQR concentrations (1 µM, 10 µM, and 50 µM) resulted in a dose-dependent augmentation of the area covered with melanophores but a reduction in the area covered by iridophores. The observations were performed in three distinct regions-the eye, dorsal head, and tail. Moreover, TQR enhanced melanophore renewal after depigmentation caused by 0.2 mM 1-phenyl-2-thiourea (PTU) treatment. qPCR analysis performed in 56-h post-fertilization (hpf) embryos demonstrated differential expression patterns of genes related to pigment development and differentiation. The most substantial findings include those indicating that TQR had no significant influence on leukocyte tyrosine kinase, GTP cyclohydrolase 2, tyrosinase-related protein 1, and forkhead box D3, however, markedly upregulated tyrosinase, dopachrome tautomerase and melanocyte inducing transcription factor, and downregulated purine nucleoside phosphorylase 4a. The present study suggests that TQR is an agent with multidirectional properties toward pigment cell formation and distribution in the zebrafish larvae and therefore points to the involvement of P-glycoprotein in this process.
Topics: ATP Binding Cassette Transporter, Subfamily B, Member 1; Animals; Cell Differentiation; Gene Expression Profiling; Gene Expression Regulation; Gene Expression Regulation, Developmental; Larva; Melanins; Melanophores; Pigmentation; Quinolines; RNA, Messenger; Zebrafish; Zebrafish Proteins
PubMed: 33804686
DOI: 10.3390/cells10030690 -
Theranostics 2020Prohibitin (PHB, also known as PHB1 or BAP32), is a highly conserved 31kDa protein that expressed in many cellular compartments, such as mitochondria, nucleus, cytosol,...
Prohibitin (PHB, also known as PHB1 or BAP32), is a highly conserved 31kDa protein that expressed in many cellular compartments, such as mitochondria, nucleus, cytosol, and plasma membrane, and plays roles in regulating the transcription of genes, apoptosis, and mitochondrial biogenesis. There is a report that Prohibitin expression is required for the stimulation of pigmentation by melanogenin. However, no studies have been published on the function of PHB in melanocytes, especially in melanosome transport. : Immunofluorescence was performed to confirm the localization of PHB. RNA transfections, Co-immunoprecipitation, western blotting and proximity ligation assay were performed to find binding state between proteins and demonstrate functions of PHB on melanosome transport. : PHB is located in the melanosome and perinuclear aggregation of melanosome is induced when expression of PHB is reduced with no influence on melanin contents. PHB binds directly to Rab27a and Mlph but not Myosin-Va. Rab27a and Mlph bind to specific domains of PHB. Reduced expression of PHB led to the impaired binding affinity between Rab27a and Mlph. : PHB regulates melanosome transport by linking to Rab27a and Mlph in melanocytes. Targeting and regulating PHB not only manages pigmentation in melanocytes, but also controls hyperpigmentation in melanoma.
Topics: Adaptor Proteins, Signal Transducing; Animals; Biological Transport; Cells, Cultured; Melanins; Melanosomes; Mice; Mice, Inbred C57BL; Pigmentation; Prohibitins; Protein Binding; Repressor Proteins; rab27 GTP-Binding Proteins
PubMed: 32226526
DOI: 10.7150/thno.41383 -
International Journal of Molecular... Sep 2009Skin pigmentary abnormalities are seen as aesthetically unfavorable and have led to the development of cosmetic and therapeutic treatment modalities of varying efficacy.... (Review)
Review
Skin pigmentary abnormalities are seen as aesthetically unfavorable and have led to the development of cosmetic and therapeutic treatment modalities of varying efficacy. Hence, several putative depigmenting agents aimed at modulating skin pigmentation are currently being researched or sold in commercially available products. In this review we will discuss the regulation of processes that control skin complexion coloration. This includes direct inhibition of tyrosinase and related melanogenic enzymes, regulation of melanocyte homeostasis, alteration of constitutive and facultative pigmentation and down-regulation of melanosome transfer to the keratinocytes. These various processes, in the complex mechanism of skin pigmentation, can be regulated individually or concomitantly to alter complexion coloration and thus ameliorate skin complexion diseases.
Topics: Animals; Enzyme Inhibitors; Gene Expression Regulation, Enzymologic; Humans; Melanocytes; Melanosomes; Monophenol Monooxygenase; Protein Processing, Post-Translational; Signal Transduction; Skin Pigmentation
PubMed: 19865532
DOI: 10.3390/ijms10094066 -
Developmental Biology Jan 2008Neural crest-derived pigment cell development has been used extensively to study cell fate specification, migration, proliferation, survival and differentiation. Many of... (Comparative Study)
Comparative Study
Neural crest-derived pigment cell development has been used extensively to study cell fate specification, migration, proliferation, survival and differentiation. Many of the genes and regulatory mechanisms required for pigment cell development are conserved across vertebrates. The zebrafish mutant colgate (col)/histone deacetylase1 (hdac1) has reduced numbers, delayed differentiation and decreased migration of neural crest-derived melanophores and their precursors. In hdac1(col) mutants normal numbers of premigratory neural crest cells are induced. Later, while there is only a slight reduction in the number of neural crest cells in hdac1(col) mutants, there is a severe reduction in the number of mitfa-positive melanoblasts suggesting that hdac1 is required for melanoblast specification. Concomitantly, there is a significant increase in and prolonged expression of foxd3 in neural crest cells in hdac1(col) mutants. We found that partially reducing Foxd3 expression in hdac1(col) mutants rescues mitfa expression and the melanophore defects in hdac1(col) mutants. Furthermore, we demonstrate the ability of Foxd3 to physically interact at the mitfa promoter. Because mitfa is required for melanoblast specification and development, our results suggest that hdac1 is normally required to suppress neural crest foxd3 expression thus de-repressing mitfa resulting in melanogenesis by a subset of neural crest-derived cells.
Topics: Animals; Base Sequence; Binding Sites; Cell Movement; Electrophoretic Mobility Shift Assay; Embryo, Nonmammalian; Forkhead Transcription Factors; Gene Expression Regulation, Developmental; Histone Deacetylase 1; Histone Deacetylases; In Situ Hybridization; Melanophores; Microinjections; Microphthalmia-Associated Transcription Factor; Models, Biological; Molecular Sequence Data; Mutation; Neural Crest; Oligonucleotides, Antisense; Promoter Regions, Genetic; Protein Binding; Zebrafish; Zebrafish Proteins
PubMed: 18068699
DOI: 10.1016/j.ydbio.2007.10.045 -
Developmental Biology Apr 2020To investigate the spatiotemporal dynamics of skin pattern formation, we developed a simple method for artificially disarranging the placement of all three pigment cell...
To investigate the spatiotemporal dynamics of skin pattern formation, we developed a simple method for artificially disarranging the placement of all three pigment cell types in the body trunk of zebrafish (Danio rerio). We generated transgenic fish with melanophores that ectopically expressed a variant of channelrhodopsin-2 (ChR2). Blue light (BL) irradiation induced melanophore depolarization and random migration; the latter resulted in the disarrangement of the two other pigment cell types (xanthophores and iridophores). This BL disarrangement (BLD) method was effective in both young and adult fish, but it did not affect the initial placement of pigment cells in juvenile fish (approximately 5 weeks post-fertilization). Irradiation with BL was not harmful to cells, and the patterning process immediately resumed when BL was switched off. Using the BLD method, we demonstrated that interactions between pigment cells determined stripe width in the absence of any pre-set positional cues, while the initial horizontal alignment of iridophores determined their directionality. The BLD method can be adapted to any zebrafish skin-pattern mutant, providing a novel tool for analyzing pattern formation mechanisms under a variety of conditions and facilitating further study in this field.
Topics: Animals; Animals, Genetically Modified; Body Patterning; Channelrhodopsins; Embryonic Development; Melanophores; Optogenetics; Skin Pigmentation; Zebrafish
PubMed: 30578760
DOI: 10.1016/j.ydbio.2018.12.019 -
Developmental Dynamics : An Official... Oct 2021Amphibians possess three kinds of dermal chromatophore: melanophores, iridophores, and xanthophores. Knockout Xenopus tropicalis that lack the pigmentation of...
BACKGROUND
Amphibians possess three kinds of dermal chromatophore: melanophores, iridophores, and xanthophores. Knockout Xenopus tropicalis that lack the pigmentation of melanophores and iridophores have been reported. The identification of the causal genes for xanthophore pigmentation or differentiation could lead to the creation of a see-through frog without three chromatophores. The genes causing xanthophore differentiation mutants are slc2a11b and slc2a15b in Japanese medaka (Oryzias latipes).
RESULTS
To obtain a heritable line of X tropicalis mutants without yellow pigment, we generated slc2a7 and slc2a15a knockout animals because they have the greatest similarity to the O latipes slc2a11b and slc2a15b genes. The slc2a7 knockout frog had a bluish skin and there were no visible yellow pigments in stereo microscope and skin section observations. Furthermore, no pterinosomes, which are characteristic of xanthophores, were observed via transmission electron microscopy in the skin of knockout animals.
CONCLUSIONS
We report the successful generation of a heritable no-yellow-pigment X tropicalis mutant after knock out of the slc2a7 gene. This finding will enable the creation of a see-through frog with no chromatophores.
Topics: Animals; Animals, Genetically Modified; Chromatophores; Gene Expression Regulation, Developmental; Gene Knockout Techniques; Glucose Transport Proteins, Facilitative; Melanophores; Pigmentation; Xenopus
PubMed: 33760303
DOI: 10.1002/dvdy.334