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Zhi J, Li F, Jiang X, Bai R. Thyroid receptor β: A promising target for developing novel anti-androgenetic alopecia drugs. Drug Discov Today 2024; 29:104013. [PMID: 38705510 DOI: 10.1016/j.drudis.2024.104013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2024] [Revised: 04/22/2024] [Accepted: 04/29/2024] [Indexed: 05/07/2024]
Abstract
Androgenetic alopecia (AGA) significantly impacts the self-confidence and mental well-being of people. Recent research has revealed that thyroid receptor β (TRβ) agonists can activate hair follicles and effectively stimulate hair growth. This review aims to comprehensively elucidate the specific mechanism of action of TRβ in treating AGA from various perspectives, highlighting its potential as a drug target for combating AGA. Moreover, this review provides a thorough summary of the research advances in TRβ agonist candidates with anti-AGA efficacy and outlines the structure-activity relationships (SARs) of TRβ agonists. We hope that this review will provide practical information for the development of effective anti-alopecia drugs.
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Affiliation(s)
- Jia Zhi
- School of Pharmacy, Hangzhou Normal University, Hangzhou, 311121, P.R. China; Key Laboratory of Elemene Class Anti-tumor Chinese Medicines, Engineering Laboratory of Development and Application of Traditional Chinese Medicines, Collaborative Innovation Center of Traditional Chinese Medicines of Zhejiang Province, Hangzhou Normal University, Hangzhou 311121, PR China
| | - Feifan Li
- School of Pharmacy, Hangzhou Normal University, Hangzhou, 311121, P.R. China; Key Laboratory of Elemene Class Anti-tumor Chinese Medicines, Engineering Laboratory of Development and Application of Traditional Chinese Medicines, Collaborative Innovation Center of Traditional Chinese Medicines of Zhejiang Province, Hangzhou Normal University, Hangzhou 311121, PR China
| | - Xiaoying Jiang
- School of Pharmacy, Hangzhou Normal University, Hangzhou, 311121, P.R. China; Key Laboratory of Elemene Class Anti-tumor Chinese Medicines, Engineering Laboratory of Development and Application of Traditional Chinese Medicines, Collaborative Innovation Center of Traditional Chinese Medicines of Zhejiang Province, Hangzhou Normal University, Hangzhou 311121, PR China.
| | - Renren Bai
- School of Pharmacy, Hangzhou Normal University, Hangzhou, 311121, P.R. China; Key Laboratory of Elemene Class Anti-tumor Chinese Medicines, Engineering Laboratory of Development and Application of Traditional Chinese Medicines, Collaborative Innovation Center of Traditional Chinese Medicines of Zhejiang Province, Hangzhou Normal University, Hangzhou 311121, PR China.
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2
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Paus R, Sevilla A, Grichnik JM. Human Hair Graying Revisited: Principles, Misconceptions, and Key Research Frontiers. J Invest Dermatol 2024; 144:474-491. [PMID: 38099887 DOI: 10.1016/j.jid.2023.09.276] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Revised: 08/09/2023] [Accepted: 09/12/2023] [Indexed: 02/25/2024]
Abstract
Hair graying holds psychosocial importance and serves as an excellent model for studying human pigmentation and aging in an accessible miniorgan. Current evidence suggests that graying results from an interindividually varying mixture of cumulative oxidative and DNA damage, excessive mTORC1 activity, melanocyte senescence, and inadequate production of pigmentation-promoting factors in the hair matrix. Various regulators modulate this process, including genetic factors (DNA repair defects and IRF4 sequence variation, peripheral clock genes, P-cadherin signaling, neuromediators, HGF, KIT ligand secretion, and autophagic flux. This leads to reduced MITF- and tyrosinase-controlled melanogenesis, defective melanosome transfer to precortical matrix keratinocytes, and eventual depletion of hair follicle (HF) pigmentary unit (HFPU) melanocytes and their local progenitors. Graying becomes irreversible only when bulge melanocyte stem cells are also depleted, occurring later in this process. Distinct pigmentary microenvironments are created as the HF cycles: early anagen is the most conducive phase for melanocytic reintegration and activation, and only during anagen can the phenotype of hair graying and repigmentation manifest, whereas the HFPU disassembles during catagen. The temporary reversibility of graying is highlighted by several drugs and hormones that induce repigmentation, indicating potential target pathways. We advise caution in directly applying mouse model concepts, define major open questions, and discuss future human antigraying strategies.
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Affiliation(s)
- Ralf Paus
- Dr. Phillip Frost Department of Dermatology & Cutaneous Surgery, University of Miami Miller School of Medicine, Miami, Florida, USA; CUTANEON - Skin & Hair Innovations, Hamburg, Germany; Monasterium Laboratory, Münster, Germany.
| | - Alec Sevilla
- Dr. Phillip Frost Department of Dermatology & Cutaneous Surgery, University of Miami Miller School of Medicine, Miami, Florida, USA; Department of Internal Medicine, Lakeland Regional Health, Lakeland, Florida, USA
| | - James M Grichnik
- Department of Dermatology & Cutaneous Surgery, University of South Florida, Tampa, Florida, USA
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3
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Adav SS, Ng KW. Recent omics advances in hair aging biology and hair biomarkers analysis. Ageing Res Rev 2023; 91:102041. [PMID: 37634889 DOI: 10.1016/j.arr.2023.102041] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Revised: 06/27/2023] [Accepted: 08/23/2023] [Indexed: 08/29/2023]
Abstract
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.
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Affiliation(s)
- Sunil S Adav
- School of Materials Science and Engineering, Nanyang Technological University, Singapore 639798, Singapore
| | - Kee Woei Ng
- School of Materials Science and Engineering, Nanyang Technological University, Singapore 639798, Singapore; Nanyang Environment and Water Research Institute, Nanyang Technological University, 1 Cleantech Loop, CleanTech One, 637141, Singapore.
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4
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Casalou C, Mayatra JM, Tobin DJ. Beyond the Epidermal-Melanin-Unit: The Human Scalp Anagen Hair Bulb Is Home to Multiple Melanocyte Subpopulations of Variable Melanogenic Capacity. Int J Mol Sci 2023; 24:12809. [PMID: 37628992 PMCID: PMC10454394 DOI: 10.3390/ijms241612809] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Revised: 07/26/2023] [Accepted: 08/07/2023] [Indexed: 08/27/2023] Open
Abstract
The visual appearance of humans is derived significantly from our skin and hair color. While melanin from epidermal melanocytes protects our skin from the damaging effects of ultraviolet radiation, the biological value of pigmentation in the hair follicle, particularly on the scalp, is less clear. In this study, we explore the heterogeneity of pigment cells in the human scalp anagen hair follicle bulb, a site conventionally viewed to be focused solely on pigment production for transfer to the hair shaft. Using c-KIT/CD117 microbeads, we isolated bulbar c-KIT-positive and c-KIT-negative melanocytes. While both subpopulations expressed MITF, only the c-KIT-positive fraction expressed SOX10. We further localized bulbar melanocyte subpopulations (expressing c-KIT, SOX10, MITF, and DCT) that exhibited distinct/variable expression of downstream differentiation-associated melanosome markers (e.g., gp100 and Melan-A). The localization of a second 'immature' SOX10 negative melanocyte population, which was c-KIT/MITF double-positive, was identified outside of the melanogenic zone in the most peripheral/proximal matrix. This study describes an approach to purifying human scalp anagen hair bulb melanocytes, allowing us to identify unexpected levels of melanocyte heterogeneity. The function of the more immature melanocytes in this part of the hair follicle remains to be elucidated. Could they be in-transit migratory cells ultimately destined to synthesize melanin, or could they contribute to the hair follicle in non-melanogenic ways?
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Affiliation(s)
- Cristina Casalou
- Charles Institute of Dermatology, School of Medicine, University College Dublin, D04 V1W8 Dublin, Ireland
| | - Jay M. Mayatra
- Charles Institute of Dermatology, School of Medicine, University College Dublin, D04 V1W8 Dublin, Ireland
| | - Desmond J. Tobin
- Charles Institute of Dermatology, School of Medicine, University College Dublin, D04 V1W8 Dublin, Ireland
- Conway Institute of Biomedical and Biomolecular Science, University College Dublin, D04 V1W8 Dublin, Ireland
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5
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Mao MQ, Jing J, Miao YJ, Lv ZF. Epithelial-Mesenchymal Interaction in Hair Regeneration and Skin Wound Healing. Front Med (Lausanne) 2022; 9:863786. [PMID: 35492363 PMCID: PMC9048199 DOI: 10.3389/fmed.2022.863786] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Accepted: 03/16/2022] [Indexed: 11/30/2022] Open
Abstract
Interactions between epithelial and mesenchymal cells influence hair follicles (HFs) during embryonic development and skin regeneration following injury. Exchanging soluble molecules, altering key pathways, and extracellular matrix signal transduction are all part of the interplay between epithelial and mesenchymal cells. In brief, the mesenchyme contains dermal papilla cells, while the hair matrix cells and outer root sheath represent the epithelial cells. This study summarizes typical epithelial–mesenchymal signaling molecules and extracellular components under the control of follicular stem cells, aiming to broaden our current understanding of epithelial–mesenchymal interaction mechanisms in HF regeneration and skin wound healing.
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6
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Dilshat R, Vu HN, Steingrímsson E. Epigenetic regulation during melanocyte development and homeostasis. Exp Dermatol 2021; 30:1033-1050. [PMID: 34003523 DOI: 10.1111/exd.14391] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2020] [Revised: 04/09/2021] [Accepted: 05/09/2021] [Indexed: 12/26/2022]
Abstract
Melanocytes originate in the neural crest as precursor cells which then migrate and proliferate to reach their destination where they differentiate into pigment-producing cells. Melanocytes not only determine the colour of hair, skin and eyes but also protect against the harmful effects of UV irradiation. The establishment of the melanocyte lineage is regulated by a defined set of transcription factors and signalling pathways that direct the specific gene expression programmes underpinning melanoblast specification, survival, migration, proliferation and differentiation. In addition, epigenetic modifiers and replacement histones play key roles in regulating gene expression and its timing during the different steps of this process. Here, we discuss the evidence for the role of epigenetic regulators in melanocyte development and function and how they interact with transcription factors and signalling pathways to establish and maintain this important cell lineage.
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Affiliation(s)
- Ramile Dilshat
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, BioMedical Center, University of Iceland, Reykjavik, Iceland
| | - Hong Nhung Vu
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, BioMedical Center, University of Iceland, Reykjavik, Iceland
| | - Eiríkur Steingrímsson
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, BioMedical Center, University of Iceland, Reykjavik, Iceland
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7
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Liu W, Li K, Wang G, Yang L, Qu Q, Fan Z, Sun Y, Huang J, Miao Y, Hu Z. Impairment of autophagy may be associated with follicular miniaturization in androgenetic alopecia by inducing premature catagen. J Dermatol 2020; 48:289-300. [PMID: 33258150 DOI: 10.1111/1346-8138.15672] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2019] [Accepted: 10/04/2020] [Indexed: 12/16/2022]
Abstract
Androgenetic alopecia is the most common form of hair loss disorder. The features of this process are shortening of the anagen phase in hair cycling and progressive miniaturization of the hair follicle. However, the mechanisms in androgenetic alopecia are still unclear, and the treatment methods are also limited. Therefore, further study on the pathogenesis and new therapies for androgenetic alopecia are urgently needed. In this study, we found that endogenous autophagy was severely impaired, accompanied by increased apoptosis in early catagen-like miniaturized hair follicles from the balding scalps of androgenetic alopecia patients. Moreover, inhibition of autophagy using 3-methyladenine could induce apoptosis, premature hair follicle regression and slow down the hair growth in organ-cultured hair follicles. Taken together, these results suggest that impairment of autophagy could be a potential mechanism in androgenetic alopecia.
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Affiliation(s)
- Weiwen Liu
- Department of Plastic and Aesthetic Surgery, Nanfang Hospital of Southern Medical University, Guangzhou, China.,Laboratory for Tissue Microenvironment, RIKEN Center for Biosystems Dynamics Research (BDR), Kobe, Japan
| | - Kaitao Li
- Department of Plastic and Aesthetic Surgery, Nanfang Hospital of Southern Medical University, Guangzhou, China
| | - Gaofeng Wang
- Department of Plastic and Aesthetic Surgery, Nanfang Hospital of Southern Medical University, Guangzhou, China.,Department of Dermatology, Johns Hopkins School of Medicine, Baltimore, Maryland, USA
| | - Lunan Yang
- Department of Plastic and Aesthetic Surgery, Nanfang Hospital of Southern Medical University, Guangzhou, China
| | - Qian Qu
- Department of Plastic and Aesthetic Surgery, Nanfang Hospital of Southern Medical University, Guangzhou, China
| | - Zhexiang Fan
- Department of Plastic and Aesthetic Surgery, Nanfang Hospital of Southern Medical University, Guangzhou, China
| | - Yang Sun
- Department of Plastic and Aesthetic Surgery, Nanfang Hospital of Southern Medical University, Guangzhou, China
| | - Junfei Huang
- Department of Plastic and Aesthetic Surgery, Nanfang Hospital of Southern Medical University, Guangzhou, China
| | - Yong Miao
- Department of Plastic and Aesthetic Surgery, Nanfang Hospital of Southern Medical University, Guangzhou, China
| | - Zhiqi Hu
- Department of Plastic and Aesthetic Surgery, Nanfang Hospital of Southern Medical University, Guangzhou, China
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8
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Daniels G, Akram S, Westgate GE, Tamburic S. Can plant-derived phytochemicals provide symptom relief for hair loss? A critical review. Int J Cosmet Sci 2019; 41:332-345. [DOI: 10.1111/ics.12554] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2019] [Revised: 05/23/2019] [Accepted: 06/22/2019] [Indexed: 12/16/2022]
Affiliation(s)
- G. Daniels
- Cosmetic Science Research Group; University of the Arts, London; 20 John Princes Street London U.K
| | - S. Akram
- Cosmetic Science Research Group; University of the Arts, London; 20 John Princes Street London U.K
| | - G. E. Westgate
- Gill Westgate Consultancy Ltd; Stevington Bedfordshire U.K
| | - S. Tamburic
- Cosmetic Science Research Group; University of the Arts, London; 20 John Princes Street London U.K
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9
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Qiu W, Chuong CM, Lei M. Regulation of melanocyte stem cells in the pigmentation of skin and its appendages: Biological patterning and therapeutic potentials. Exp Dermatol 2019; 28:395-405. [PMID: 30537004 DOI: 10.1111/exd.13856] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2018] [Revised: 11/27/2018] [Accepted: 12/05/2018] [Indexed: 12/13/2022]
Abstract
Skin evolves essential appendages and indispensable types of cells that synergistically insulate the body from environmental insults. Residing in the specific regions in the skin such as epidermis, dermis and hair follicle, melanocytes perform an array of vital functions including defending the ultraviolet radiation and diversifying animal appearance. As one of the adult stem cells, melanocyte stem cells in the hair follicle bulge niche can proliferate, differentiate and keep quiescence to control and coordinate tissue homeostasis, repair and regeneration. In synchrony with hair follicle stem cells, melanocyte stem cells in the hair follicles undergo cyclic activation, degeneration and resting phases, to pigment the hairs and to preserve the stem cells. Disorder of melanocytes results in severe skin problems such as canities, vitiligo and even melanoma. Here, we compare and summarize recent discoveries about melanocyte in the skin, particularly in the hair follicle. A better understanding of the physiological and pathological regulation of melanocyte and melanocyte stem cell behaviours will help to guide the clinical applications in regenerative medicine.
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Affiliation(s)
- Weiming Qiu
- Department of Dermatology, Wuhan General Hospital of Chinese People's Liberation Army, Wuhan, China
| | - Cheng-Ming Chuong
- Department of Pathology, University of Southern California, Los Angeles, California.,Integrative Stem Cell Center, China Medical University Hospital, China Medical University, Taichung, Taiwan
| | - Mingxing Lei
- Integrative Stem Cell Center, China Medical University Hospital, China Medical University, Taichung, Taiwan.,Institute of New Drug Development, College of Biopharmaceutical and Food Sciences, China Medical University, Taichung, Taiwan
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10
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Paracrine Secreted Frizzled-Related Protein 4 Inhibits Melanocytes Differentiation in Hair Follicle. Stem Cells Int 2017; 2017:2857478. [PMID: 28337220 PMCID: PMC5350338 DOI: 10.1155/2017/2857478] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2016] [Revised: 01/04/2017] [Accepted: 01/24/2017] [Indexed: 02/04/2023] Open
Abstract
Wnt signaling plays crucial role in regulating melanocyte stem cells/melanocyte differentiation in the hair follicle. However, how the Wnt signaling is balanced to be overactivated to control follicular melanocytes behavior remains unknown. Here, by using immunofluorescence staining, we showed that secreted frizzled-related protein 4 (sFRP4) is preferentially expressed in the skin epidermal cells rather than in melanocytes. By overexpression of sFRP4 in skin cells in vivo and in vitro, we found that sFRP4 attenuates activation of Wnt signaling, resulting in decrease of melanocytes differentiation in the regenerating hair follicle. Our findings unveiled a new regulator that involves modulating melanocytes differentiation through a paracrine mechanism in hair follicle, supplying a hope for potential therapeutic application to treat skin pigmentation disorders.
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11
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12-O-tetradecanoylphorbol-13-acetate activates hair follicle melanocytes for hair pigmentation via Wnt/β-catenin signaling. Cell Tissue Res 2016; 366:329-340. [DOI: 10.1007/s00441-016-2450-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2015] [Accepted: 05/27/2016] [Indexed: 10/21/2022]
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12
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Yoon JS, Choi M, Shin CY, Paik SH, Kim KH, Kwon O. Development of a Model for Chemotherapy-Induced Alopecia: Profiling of Histological Changes in Human Hair Follicles after Chemotherapy. J Invest Dermatol 2016; 136:584-92. [PMID: 26774950 DOI: 10.1038/jid.2015.358] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2014] [Revised: 08/26/2015] [Accepted: 08/31/2015] [Indexed: 11/10/2022]
Abstract
Optimized research models are required to further understand the pathogenesis and prophylaxis of chemotherapy-induced alopecia. Our aim was to develop a mouse model for chemotherapy-induced alopecia by follicular unit transplantation of human hair follicles onto immunodeficient mice. Twenty-two weeks after transplantation, a single dose of cyclophosphamide (Cph) was administered to mice in the Cph100 (100 mg/kg) and Cph150 (150 mg/kg) groups. On day 6, hair follicles showed dystrophic changes, with swollen dermal papilla and ectopic melanin clumping in the hair bulb. In addition, upregulated expression of apoptotic regulators [P53, Fas/Fas-ligand, tumor necrosis factor-related apoptosis-inducing ligand/tumor necrosis factor-related apoptosis-inducing ligand receptor (TRAIL/TRAIL receptor), and Bax], increased apoptotic matrix keratinocytes, downregulated Ki67 expression, and decreased melanogenic protein in the hair bulb were noted in both groups. After 12 treatment days, hair follicles in Cph100 mice appeared to diminish dystrophic changes. In contrast, hair follicles of Cph150 mice prematurely entered a dystrophic catagen phase after 9 treatment days, and immunofluorescence staining for Ki67 and melanogenic protein expressions was barely visible. Two hair follicle damage response pathways were observed in this model, namely dystrophic anagen (Cph100) and catagen (Cph150) pathways. Our model might be useful for further understanding the impact of chemotherapy on human hair follicles.
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Affiliation(s)
- Ji-Seon Yoon
- Laboratory of Cutaneous Aging and Hair Research, Biomedical Research Institute, Seoul National University Hospital, Seoul, Korea; Institute of Human-Environment Interface Biology, Seoul National University College of Medicine, Seoul, Korea
| | - Mira Choi
- Laboratory of Cutaneous Aging and Hair Research, Biomedical Research Institute, Seoul National University Hospital, Seoul, Korea; Institute of Human-Environment Interface Biology, Seoul National University College of Medicine, Seoul, Korea; Department of Dermatology, Seoul National University College of Medicine, Seoul, Korea
| | - Chang Yup Shin
- Laboratory of Cutaneous Aging and Hair Research, Biomedical Research Institute, Seoul National University Hospital, Seoul, Korea; Institute of Human-Environment Interface Biology, Seoul National University College of Medicine, Seoul, Korea
| | - Seung Hwan Paik
- Laboratory of Cutaneous Aging and Hair Research, Biomedical Research Institute, Seoul National University Hospital, Seoul, Korea; Institute of Human-Environment Interface Biology, Seoul National University College of Medicine, Seoul, Korea; Department of Dermatology, Seoul National University College of Medicine, Seoul, Korea
| | - Kyu Han Kim
- Laboratory of Cutaneous Aging and Hair Research, Biomedical Research Institute, Seoul National University Hospital, Seoul, Korea; Institute of Human-Environment Interface Biology, Seoul National University College of Medicine, Seoul, Korea; Department of Dermatology, Seoul National University College of Medicine, Seoul, Korea
| | - Ohsang Kwon
- Laboratory of Cutaneous Aging and Hair Research, Biomedical Research Institute, Seoul National University Hospital, Seoul, Korea; Institute of Human-Environment Interface Biology, Seoul National University College of Medicine, Seoul, Korea; Department of Dermatology, Seoul National University College of Medicine, Seoul, Korea.
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13
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Vesela B, Matalova E. Detection of Bim and Puma in mouse hair follicles using immunofluorescence and TUNEL assay double staining. Biotech Histochem 2015; 90:587-93. [DOI: 10.3109/10520295.2015.1062916] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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14
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Veselá B, Matalová E. Expression of apoptosis-related genes in the mouse skin during the first postnatal catagen stage, focused on localization of Bnip3L and caspase-12. Connect Tissue Res 2015; 56:326-35. [PMID: 25943459 DOI: 10.3109/03008207.2015.1040546] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Hair follicles undergo repetitive stages of cell proliferation and programmed cell death. The catagen stage of physiological apoptosis is connected with dynamic changes in morphology and alterations in gene expression. However, hair follicle apoptosis must be in balance with events in surrounding tissues, such as keratinocyte cornification, to maintain complex skin homeostasis. Several pro- and anti-apoptotic molecules in the skin have been reported but mainly in pathological states. In this investigation, apoptosis-related gene expression was examined during the first catagen stage of mouse hair follicle development by PCR arrays under physiological conditions. Postnatal stages P15 and P17, representing early and late catagen stages, were evaluated relatively to stage P6, representing the hair follicle growing phase, to demonstrate dynamics of gene activation during the catagen. Several statistically significant alterations were observed at P15 and particularly at P17. Bnip3L and caspase-12 identified by the PCR arrays at both catagen stages were additionally localized using immunofluorescence and were reported in physiological hair development for the first time.
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Affiliation(s)
- Barbora Veselá
- Institute of Animal Physiology and Genetics AS CR , Brno , Czech Republic
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15
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SCF/c-kit signaling is required in 12-O-tetradecanoylphorbol-13-acetate-induced migration and differentiation of hair follicle melanocytes for epidermal pigmentation. Cell Tissue Res 2015; 360:333-46. [DOI: 10.1007/s00441-014-2101-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2014] [Accepted: 12/18/2014] [Indexed: 11/27/2022]
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16
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Huang JM, Hornyak TJ. Polycomb group proteins--epigenetic repressors with emerging roles in melanocytes and melanoma. Pigment Cell Melanoma Res 2015; 28:330-9. [PMID: 25475071 DOI: 10.1111/pcmr.12341] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2014] [Accepted: 11/28/2014] [Indexed: 12/21/2022]
Abstract
Melanocytes undergo rapid and significant changes in their gene expression programs at regular intervals during development and the hair follicle cycle. In melanoma, the gene expression pattern found in normal melanocytes is disrupted. These gene expression patterns are regulated in part by post-translational histone modifications catalyzed by Polycomb group (PcG) proteins, which play a major role in many developmental processes and are often altered in cancer. In this review, we discuss the role of the PcG proteins in stem cell and cancer biology, in general, as well as in melanocyte development and melanomagenesis. Highlights include the discussion of newly identified treatments that target the activity of PcG proteins as well as new developments in the understanding of the role that these proteins play in melanocyte biology.
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Affiliation(s)
- Jennifer M Huang
- Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, MD, USA
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17
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Abstract
INTRODUCTION Melanocytes produce pigment granules that color both skin and hair. In the hair follicles melanocytes are derived from stem cells (MelSCs) that are present in hair bulges or sub-bulge regions and function as melanocyte reservoirs. Quiescence, maintenance, activation and proliferation of MelSCs are controlled by specific activities in the microenvironment that can influence the differentiation and regeneration of melanocytes. Therefore, understanding MelSCs and their niche may lead to use of MelSCs in new treatments for various pigmentation disorders. AREAS COVERED We describe here pathophysiological mechanisms by which melanocyte defects lead to skin pigmentation disorders such as vitiligo and hair graying. The development, migration and proliferation of melanocytes and factors involved in the survival, maintenance and regeneration of MelSCs are reviewed with regard to the biological roles and potential therapeutic applications in skin pigmentation diseases. EXPERT OPINION MelSC biology and niche factors have been studied mainly in murine experimental models. Human MelSC markers or methods to isolate them are much less well understood. Identification, isolation and culturing of human MelSCs would represent a major step toward new biological therapeutic options for patients with recalcitrant pigmentary disorders or hair graying. By modulating the niche factors for MelSCs, it may one day be possible to control skin pigmentary disorders and prevent or reverse hair graying.
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Affiliation(s)
- Ju Hee Lee
- Massachusetts General Hospital, Harvard Medical School, Department of Dermatology and Cutaneous Biology Research Center , Boston, MA 02129 , USA +1 617 643 5428 ; +1 617 643 6588 ;
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18
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Uslu S, Oktem G, Uysal A, Soner BC, Arbak S, Ince U. Stem cell and extracellular matrix-related molecules increase following melatonin treatment in the skin of postmenopausal rats. Cell Biol Int 2014; 38:924-32. [PMID: 24740758 DOI: 10.1002/cbin.10286] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2013] [Accepted: 03/13/2014] [Indexed: 12/11/2022]
Abstract
The menopause has a negative effect in the skin. Melatonin affects skin functions and structures through actions mediated by cell-surface and putative-nuclear receptors expressed in skin cell. We have therefore determined the effects of melatonin treatment on stem cell in the epidermis and extracellular matrix related molecules in the dermis the skin of postmenopausal rats. A total of 45 female rats were divided into 5 groups: control group, group A [ovariectomy (OVX)], group B (OVX +10 mg/kg/day melatonin), group C (OVX +30 mg/kg/day melatonin), group S (sham operated + 10 mg/kg/day melatonin). Ventral skin samples were excised at 12th week after ovariectomy. Hematoxylin-eosin, periodic acid- methylamine silver, elastic van Gieson staining techniques were used to measure histomorphometrically the thickness of elastic fibers and basement membrane, depths of the epidermis, dermis, and subcutaneous fat layer. Immunohistochemical staining methods were used for fibroblast growth factor β (FGF β), collagen type I, fibronectin, β-catenin, c-kit, c-Myc evaluation. Epidermal thickness, subcutaneous fat layer, and elastic fibers were significantly decreased in group C, and there was a significant increase after melatonin treatment. Although there was no difference in dermal thickness of group C, melatonin also significantly increased the dermal thickness. High FGF β, type I collagen, fibronectin, β-catenin, c-Myc immunoreactivity developed following melatonin in all groups. Thus melatonin treatment of postmenopausal rats was mostly due to the decrease of stem cell and extracellular matrix-related molecules in the skin.
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Affiliation(s)
- Serap Uslu
- Histology and Embryology, Acıbadem University, Vocational School of Health Services, Istanbul, Turkey
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19
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Yamada T, Hasegawa S, Inoue Y, Date Y, Yamamoto N, Mizutani H, Nakata S, Matsunaga K, Akamatsu H. Wnt/β-Catenin and Kit Signaling Sequentially Regulate Melanocyte Stem Cell Differentiation in UVB-Induced Epidermal Pigmentation. J Invest Dermatol 2013; 133:2753-2762. [DOI: 10.1038/jid.2013.235] [Citation(s) in RCA: 94] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2012] [Revised: 04/25/2013] [Accepted: 04/27/2013] [Indexed: 11/09/2022]
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20
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Seiberg M. Age-induced hair greying - the multiple effects of oxidative stress. Int J Cosmet Sci 2013; 35:532-8. [PMID: 24033376 DOI: 10.1111/ics.12090] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2013] [Accepted: 08/20/2013] [Indexed: 01/14/2023]
Abstract
An obvious sign of ageing is hair greying, or the loss of pigment production and deposition within the hair shafts. Numerous mechanisms, acting at different levels and follicular locations, contribute to hair greying, ranging from melanocyte stem cells defects to follicular melanocyte death. One key issue that is in common to these processes is oxidative damage. At the hair follicle stem cells niche, oxidative stress, accelerated by B-cell lymphoma 2 gene (BCL-2) depletion, leads to selective apoptosis and diminution of melanocyte stem cells, reducing the repopulation of newly formed anagen follicles. Melanotic bulbar melanocytes express high levels of BCL-2 to enable survival from melanogenesis- and ultraviolet A (UVA)-induced reactive oxygen species (ROS) attacks. With ageing, the bulbar melanocyte expression of anti-oxidant proteins such as BCL-2, and possibly TRP-2, is reduced, and the dedicated enzymatic anti-oxidant defence system throughout the follicle weakens, resulting in enhanced oxidative stress. A marked reduction in catalase expression and activity results in millimolar accumulation of hydrogen peroxide, contributing to bulbar melanocyte malfunction and death. Interestingly, amelanotic melanocytes at the outer root sheath (ORS) are somewhat less affected by these processes and survive for longer time even within the white, ageing hair follicles. Better understanding of the overtime susceptibility of melanocytes to oxidative stress at the different follicular locations might yield clues to possible therapies for the prevention and reversal of hair greying.
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Affiliation(s)
- M Seiberg
- Seiberg Consulting, LLC, Princeton, NJ, USA
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21
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Harris ML, Buac K, Shakhova O, Hakami RM, Wegner M, Sommer L, Pavan WJ. A dual role for SOX10 in the maintenance of the postnatal melanocyte lineage and the differentiation of melanocyte stem cell progenitors. PLoS Genet 2013; 9:e1003644. [PMID: 23935512 PMCID: PMC3723529 DOI: 10.1371/journal.pgen.1003644] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2013] [Accepted: 06/01/2013] [Indexed: 11/18/2022] Open
Abstract
During embryogenesis, the transcription factor, Sox10, drives the survival and differentiation of the melanocyte lineage. However, the role that Sox10 plays in postnatal melanocytes is not established. We show in vivo that melanocyte stem cells (McSCs) and more differentiated melanocytes express SOX10 but that McSCs remain undifferentiated. Sox10 knockout (Sox10(fl); Tg(Tyr::CreER)) results in loss of both McSCs and differentiated melanocytes, while overexpression of Sox10 (Tg(DctSox10)) causes premature differentiation and loss of McSCs, leading to hair graying. This suggests that levels of SOX10 are key to normal McSC function and Sox10 must be downregulated for McSC establishment and maintenance. We examined whether the mechanism of Tg(DctSox10) hair graying is through increased expression of Mitf, a target of SOX10, by asking if haploinsufficiency for Mitf (Mitf(vga9) ) can rescue hair graying in Tg(DctSox10) animals. Surprisingly, Mitf(vga9) does not mitigate but exacerbates Tg(DctSox10) hair graying suggesting that MITF participates in the negative regulation of Sox10 in McSCs. These observations demonstrate that while SOX10 is necessary to maintain the postnatal melanocyte lineage it is simultaneously prevented from driving differentiation in the McSCs. This data illustrates how tissue-specific stem cells can arise from lineage-specified precursors through the regulation of the very transcription factors important in defining that lineage.
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Affiliation(s)
- Melissa L. Harris
- Genetic Disease Research Branch, National Human Genome Institute, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Kristina Buac
- Department of Genetics, University of Georgia, Athens, Georgia, United States of America
| | - Olga Shakhova
- Cell and Developmental Biology, Institute of Anatomy, University of Zurich, Zurich, Switzerland
| | - Ramin M. Hakami
- School of Systems Biology, National Center for Biodefense and Infectious Diseases, George Mason University, Manassas, Virginia, United States of America
| | - Michael Wegner
- Institut für Biochemie, Emil-Fischer-Zentrum, Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Lukas Sommer
- Cell and Developmental Biology, Institute of Anatomy, University of Zurich, Zurich, Switzerland
| | - William J. Pavan
- Genetic Disease Research Branch, National Human Genome Institute, National Institutes of Health, Bethesda, Maryland, United States of America
- * E-mail:
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22
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Li A, Ma Y, Jin M, Mason S, Mort RL, Blyth K, Larue L, Sansom OJ, Machesky LM. Activated mutant NRas(Q61K) drives aberrant melanocyte signaling, survival, and invasiveness via a Rac1-dependent mechanism. J Invest Dermatol 2012; 132:2610-21. [PMID: 22718121 PMCID: PMC3472562 DOI: 10.1038/jid.2012.186] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2012] [Revised: 04/20/2012] [Accepted: 04/20/2012] [Indexed: 12/30/2022]
Abstract
Around a fifth of melanomas exhibit an activating mutation in the oncogene NRas that confers constitutive signaling to proliferation and promotes tumor initiation. NRas signals downstream of the major melanocyte tyrosine kinase receptor c-kit and activated NRas results in increased signaling via the extracellular signal-regulated kinase (ERK)/MAPK/ERK kinase/mitogen-activated protein kinase (MAPK) pathways to enhance proliferation. The Ras oncogene also activates signaling via the related Rho GTPase Rac1, which can mediate growth, survival, and motility signaling. We tested the effects of activated NRas(Q61K) on the proliferation, motility, and invasiveness of melanoblasts and melanocytes in the developing mouse and ex vivo explant culture as well as in a melanoma transplant model. We find an important role for Rac1 downstream of NRas(Q61K) in mediating dermal melanocyte survival in vivo in mouse, but surprisingly NRas(Q61K) does not appear to affect melanoblast motility or proliferation during mouse embryogenesis. We also show that genetic deletion or pharmacological inhibition of Rac1 in NRas(Q61K) induced melanoma suppresses tumor growth, lymph node spread, and tumor cell invasiveness, suggesting a potential value for Rac1 as a therapeutic target for activated NRas-driven tumor growth and invasiveness.
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Affiliation(s)
- Ang Li
- The Beatson Institute for Cancer Research, Garscube Estate, Glasgow, UK
| | - Yafeng Ma
- The Beatson Institute for Cancer Research, Garscube Estate, Glasgow, UK
| | - Meng Jin
- The Beatson Institute for Cancer Research, Garscube Estate, Glasgow, UK
| | - Susan Mason
- The Beatson Institute for Cancer Research, Garscube Estate, Glasgow, UK
| | - Richard L Mort
- MRC Human Genetics Unit, Western General Hospital, Edinburgh, UK
| | - Karen Blyth
- The Beatson Institute for Cancer Research, Garscube Estate, Glasgow, UK
| | - Lionel Larue
- Institut Curie, CNRS UMR3347 INSERM U1021, Institut Curie, Bat 110, Centre Universitaire, Orsay, France
| | - Owen J Sansom
- The Beatson Institute for Cancer Research, Garscube Estate, Glasgow, UK
| | - Laura M Machesky
- The Beatson Institute for Cancer Research, Garscube Estate, Glasgow, UK
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23
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Home sweet home: skin stem cell niches. Cell Mol Life Sci 2012; 69:2573-82. [PMID: 22410738 DOI: 10.1007/s00018-012-0943-3] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2011] [Revised: 02/08/2012] [Accepted: 02/13/2012] [Indexed: 12/11/2022]
Abstract
The epidermis and its appendages, such as the hair follicle (HF), continually regenerate throughout postnatal mammalian life due to the activity of resident epithelial stem cells (SCs). The follicular SC niche, or the bulge, is composed of a heterogeneous population of self-renewing multipotent cells. Multiple intrinsic molecular mechanisms promote the transition of follicular SCs from quiescence to activation. In addition, numerous extrinsic cell types influence the activity and characteristics of bulge cells. Ultimately, the balance between these intrinsic and extrinsic mechanisms influences the function of bulge cells during homeostasis and tissue regeneration and likely contributes to skin tumorigenesis. Here, we review both the intrinsic and extrinsic factors that contribute to the skin SC niche.
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24
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Rabbani P, Takeo M, Chou W, Myung P, Bosenberg M, Chin L, Taketo MM, Ito M. Coordinated activation of Wnt in epithelial and melanocyte stem cells initiates pigmented hair regeneration. Cell 2011; 145:941-955. [PMID: 21663796 DOI: 10.1016/j.cell.2011.05.004] [Citation(s) in RCA: 233] [Impact Index Per Article: 17.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2010] [Revised: 03/21/2011] [Accepted: 05/02/2011] [Indexed: 12/17/2022]
Abstract
Melanocyte stem cells (McSCs) intimately interact with epithelial stem cells (EpSCs) in the hair follicle bulge and secondary hair germ (sHG). Together, they undergo activation and differentiation to regenerate pigmented hair. However, the mechanisms behind this coordinated stem cell behavior have not been elucidated. Here, we identified Wnt signaling as a key pathway that couples the behavior of the two stem cells. EpSCs and McSCs coordinately activate Wnt signaling at the onset of hair follicle regeneration within the sHG. Using genetic mouse models that specifically target either EpSCs or McSCs, we show that Wnt activation in McSCs drives their differentiation into pigment-producing melanocytes, while EpSC Wnt signaling not only dictates hair follicle formation but also regulates McSC proliferation during hair regeneration. Our data define a role for Wnt signaling in the regulation of McSCs and also illustrate a mechanism for regeneration of complex organs through collaboration between heterotypic stem cell populations.
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Affiliation(s)
- Piul Rabbani
- Department of Dermatology, New York University School of Medicine, New York, NY 10016, USA.,Department of Cell Biology, New York University School of Medicine, New York, NY 10016, USA
| | - Makoto Takeo
- Department of Dermatology, New York University School of Medicine, New York, NY 10016, USA.,Department of Cell Biology, New York University School of Medicine, New York, NY 10016, USA
| | - WeiChin Chou
- Department of Dermatology, New York University School of Medicine, New York, NY 10016, USA.,Department of Cell Biology, New York University School of Medicine, New York, NY 10016, USA
| | - Peggy Myung
- Department of Dermatology, University Hospitals Case Western Reserve, Cleveland, OH 11100, USA
| | - Marcus Bosenberg
- Department of Dermatology, Yale University School of Medicine, New Haven, CT, USA
| | - Lynda Chin
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA 02115, USA
| | - M Mark Taketo
- Department of Pharmacology, Graduate School of Medicine, Kyoto University, Kyoto, 606-8501, Japan
| | - Mayumi Ito
- Department of Dermatology, New York University School of Medicine, New York, NY 10016, USA.,Department of Cell Biology, New York University School of Medicine, New York, NY 10016, USA
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25
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Harris ML, Baxter LL, Loftus SK, Pavan WJ. Sox proteins in melanocyte development and melanoma. Pigment Cell Melanoma Res 2010; 23:496-513. [PMID: 20444197 DOI: 10.1111/j.1755-148x.2010.00711.x] [Citation(s) in RCA: 121] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Over 10 years have passed since the first Sox gene was implicated in melanocyte development. Since then, we have discovered that SOX5, SOX9, SOX10 and SOX18 all participate as transcription factors that affect key melanocytic genes in both regulatory and modulatory fashions. Both SOX9 and SOX10 play major roles in the establishment and normal function of the melanocyte; SOX10 has been shown to heavily influence melanocyte development and SOX9 has been implicated in melanogenesis in the adult. Despite these advances, the precise cellular and molecular details of how these SOX proteins are regulated and interact during all stages of the melanocyte life cycle remain unknown. Improper regulation of SOX9 or SOX10 is also associated with cancerous transformation, and thus understanding the normal function of SOX proteins in the melanocyte will be key to revealing how these proteins contribute to melanoma.
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Affiliation(s)
- Melissa L Harris
- Genetic Disease Research Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA
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26
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Sriwiriyanont P, Hachiya A, Pickens WL, Moriwaki S, Ohuchi A, Kitahara T, Takema Y, Kitzmiller WJ, Visscher MO, Bello A, Tsuboi R, Kobinger GP. Lentiviral Vector-Mediated Gene Transfer to Human Hair Follicles. J Invest Dermatol 2009; 129:2296-9. [DOI: 10.1038/jid.2009.33] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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27
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Inoue-Narita T, Hamada K, Sasaki T, Hatakeyama S, Fujita S, Kawahara K, Sasaki M, Kishimoto H, Eguchi S, Kojima I, Beermann F, Kimura T, Osawa M, Itami S, Mak TW, Nakano T, Manabe M, Suzuki A. Pten deficiency in melanocytes results in resistance to hair graying and susceptibility to carcinogen-induced melanomagenesis. Cancer Res 2008; 68:5760-8. [PMID: 18632629 DOI: 10.1158/0008-5472.can-08-0889] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Phosphate and tensin homologue deleted on chromosome 10 (PTEN) is a tumor suppressor gene inactivated in numerous sporadic cancers, including melanomas. To analyze Pten functions in melanocytes, we used the Cre-loxP system to delete Pten specifically in murine pigment-producing cells and generated DctCrePten(flox/flox) mice. Half of DctCrePten(flox/flox) mice died shortly after birth with enlargements of the cerebral cortex and hippocampus. Melanocytes were increased in the dermis of perinatal DctCrePten(flox/flox) mice. When the mutants were subjected to repeated depilations, melanocyte stem cells in the bulge of the hair follicle resisted exhaustion and the mice were protected against hair graying. Although spontaneous melanomas did not form in DctCrePten(flox/flox) mice, large nevi and melanomas developed after carcinogen exposure. DctCrePten(flox/flox) melanocytes were increased in size and exhibited heightened activation of Akt and extracellular signal-regulated kinases, increased expression of Bcl-2, and decreased expression of p27(Kip1). Our results show that Pten is important for the maintenance of melanocyte stem cells and the suppression of melanomagenesis.
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Affiliation(s)
- Tae Inoue-Narita
- Department of Dermatology, Akita University School of Medicine, Akita, Japan
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28
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Atoyan RY, Sharov AA, Eller MS, Sargsyan A, Botchkarev VA, Gilchrest BA. Oligonucleotide treatment increases eumelanogenesis, hair pigmentation and melanocortin-1 receptor expression in the hair follicle. Exp Dermatol 2007; 16:671-7. [PMID: 17620094 DOI: 10.1111/j.1600-0625.2007.00582.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
It was previously reported that telomere homologue oligonucleotides (T-oligos) can induce a variety of cellular responses in skin including increased melanogenesis. To assess the effects of T-oligos on hair pigmentation, we administered thymidine dinucleotide (pTT), one-third of the TTAGGG telomere repeat sequence, intradermally at distinct time points of the depilation-induced hair cycle in C3H/HeJ mice. Penetration of T-oligos into the hair follicle (HF) was monitored by using FITC-labelled pTT and confocal microscopy. pTT treatment on days 1-5 after depilation, during early anagen, did not significantly alter the number and proliferation of melanocytes (Trp-2-positive cells), compared with vehicle-treated controls. However, pTT treatment on days 5-12 after depilation, during mid- to late anagen, resulted in the formation of darker hairs, that showed a significantly increased eumelanin/total melanin ratio in their sub-apical agouti band region, compared with vehicle-treated controls (P < 0.05). By RT-PCR and western blot, full thickness skin of pTT-treated mice showed increases in Trp-1, Trp-2 and tyrosinase mRNA and protein levels, compared with control mice. Western blot analyses of two receptors that positively regulate eumelanogenesis, melanocortin type 1 receptor (MC-1R) and kit, showed increased expression of MC-1R protein in pTT-treated versus control skin, while the levels of c-kit receptor remained unchanged. These data demonstrate that pTT treatment increases eumelanogenesis in HFs, associated with increased tyrosinase, TRP-1 and MC-1R expression. These data also raise the possibility of using T-oligos to modulate hair pigmentation.
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Affiliation(s)
- Ruzanna Y Atoyan
- Department of Dermatology, Boston University School of Medicine, Boston, MA 02118, USA
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29
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Abstract
Cell for cell, probably no human cancer is as aggressive as melanoma. It is among a handful of cancers whose dimensions are reported in millimeters. Tumor thickness approaching 4 mm presents a high risk of metastasis, and a diagnosis of metastatic melanoma carries with it an abysmal median survival of 6-9 mo. What features of this malignancy account for such aggressive behavior? Is it the migratory history of its cell of origin or the programmed adaptation of its differentiated progeny to environmental stress, particularly ultraviolet radiation? While the answers to these questions are far from complete, major strides have been made in our understanding of the cellular, molecular, and genetic underpinnings of melanoma. More importantly, these discoveries carry profound implications for the development of therapies focused directly at the molecular engines driving melanoma, suggesting that we may have reached the brink of an unprecedented opportunity to translate basic science into clinical advances. In this review, we attempt to summarize our current understanding of the genetics and biology of this disease, drawing from expanding genomic information and lessons from development and genetically engineered mouse models. In addition, we look forward toward how these new insights will impact on therapeutic options for metastatic melanoma in the near future.
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Affiliation(s)
- Lynda Chin
- Melanoma Program, Dana-Farber Cancer Institute, Boston, Massachusetts 02115, USA.
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30
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Abstract
Apoptosis plays an important role in many physiological processes, ranging from morphogenetic events to adult tissue homeostasis, and defects in its regulation contribute to many disorders. Here we review molecular mechanisms of apoptosis in the hair follicle (HF), whose cyclical growth pattern is repeatedly interrupted by apoptosis-driven involution (catagen). We review the common mechanisms underlying apoptosis in the HF during catagen, as well as differences in the regulation of apoptosis between distinct HF cell populations. An overview is provided on the expression and function of molecules involved in the control of various phases of the apoptotic process during catagen.
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