1
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Passeron T, King B, Seneschal J, Steinhoff M, Jabbari A, Ohyama M, Tobin DJ, Randhawa S, Winkler A, Telliez JB, Martin D, Lejeune A. Inhibition of T-cell activity in alopecia areata: recent developments and new directions. Front Immunol 2023; 14:1243556. [PMID: 38022501 PMCID: PMC10657858 DOI: 10.3389/fimmu.2023.1243556] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Accepted: 10/05/2023] [Indexed: 12/01/2023] Open
Abstract
Alopecia areata (AA) is an autoimmune disease that has a complex underlying immunopathogenesis characterized by nonscarring hair loss ranging from small bald patches to complete loss of scalp, face, and/or body hair. Although the etiopathogenesis of AA has not yet been fully characterized, immune privilege collapse at the hair follicle (HF) followed by T-cell receptor recognition of exposed HF autoantigens by autoreactive cytotoxic CD8+ T cells is now understood to play a central role. Few treatment options are available, with the Janus kinase (JAK) 1/2 inhibitor baricitinib (2022) and the selective JAK3/tyrosine kinase expressed in hepatocellular carcinoma (TEC) inhibitor ritlecitinib (2023) being the only US Food and Drug Administration-approved systemic medications thus far for severe AA. Several other treatments are used off-label with limited efficacy and/or suboptimal safety and tolerability. With an increased understanding of the T-cell-mediated autoimmune and inflammatory pathogenesis of AA, additional therapeutic pathways beyond JAK inhibition are currently under investigation for the development of AA therapies. This narrative review presents a detailed overview about the role of T cells and T-cell-signaling pathways in the pathogenesis of AA, with a focus on those pathways targeted by drugs in clinical development for the treatment of AA. A detailed summary of new drugs targeting these pathways with expert commentary on future directions for AA drug development and the importance of targeting multiple T-cell-signaling pathways is also provided in this review.
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Affiliation(s)
- Thierry Passeron
- University Côte d’Azur, Centre Hospitalier Universitaire Nice, Department of Dermatology, Nice, France
- University Côte d’Azur, INSERM, U1065, C3M, Nice, France
| | - Brett King
- Department of Dermatology, Yale University School of Medicine, New Haven, CT, United States
| | - Julien Seneschal
- Department of Dermatology and Paediatric Dermatology, National Reference Centre for Rare Skin Diseases, Saint-André Hospital, University of Bordeaux, Bordeaux, France
- Bordeaux University, Centre national de la recherche scientifique (CNRS), ImmunoConcept, UMR5164, Bordeaux, France
| | - Martin Steinhoff
- Department of Dermatology and Venereology, Hamad Medical Corporation, Doha, Qatar
- Translational Research Institute, Academic Health System, Hamad Medical Corporation, Doha, Qatar
- Dermatology Institute, Academic Health System, Hamad Medical Corporation, Doha, Qatar
- Department of Dermatology and Venereology, Weill Cornell Medicine-Qatar, Doha, Qatar
- College of Medicine, Qatar University, Doha, Qatar
- Department of Dermatology, Weill Cornell Medicine, New York, NY, United States
- College of Health and Life Sciences, Hamad Bin Khalifa University-Qatar, Doha, Qatar
| | - Ali Jabbari
- Department of Dermatology, University of Iowa, Iowa City, IA, United States
- Iowa City VA Medical Center, Iowa City, IA, United States
| | - Manabu Ohyama
- Department of Dermatology, Kyorin University Faculty of Medicine, Tokyo, Japan
| | - Desmond J. Tobin
- Charles Institute of Dermatology, UCD School of Medicine, University College Dublin, Dublin, Ireland
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2
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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: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [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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3
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Johnston DGW, Hambly R, Kearney N, Tobin DJ, Kirby B. Cell-free DNA is elevated in the serum of patients with hidradenitis suppurativa. J Dermatol 2023; 50:271-273. [PMID: 36514882 PMCID: PMC10108301 DOI: 10.1111/1346-8138.16676] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Revised: 11/15/2022] [Accepted: 11/26/2022] [Indexed: 12/15/2022]
Affiliation(s)
- Daniel G W Johnston
- Discipline of Anatomy, School of Medicine, Trinity Biomedical Sciences Institute, Trinity College Dublin, Dublin, Ireland.,UCD Charles Institute of Dermatology, University College Dublin, Dublin, Ireland
| | - Roisin Hambly
- Charles Centre for Dermatology, St Vincent's University Hospital, Dublin, Ireland
| | - Niamh Kearney
- Charles Centre for Dermatology, St Vincent's University Hospital, Dublin, Ireland
| | - Desmond J Tobin
- UCD Charles Institute of Dermatology, University College Dublin, Dublin, Ireland.,UCD Conway Institute, University College Dublin, Dublin, Ireland
| | - Brian Kirby
- UCD Charles Institute of Dermatology, University College Dublin, Dublin, Ireland.,Charles Centre for Dermatology, St Vincent's University Hospital, Dublin, Ireland
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4
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Uzunbajakava NE, Tobin DJ, Botchkareva NV, Dierickx C, Bjerring P, Town G. Highlighting nuances of blue light phototherapy: Mechanisms and safety considerations. J Biophotonics 2023; 16:e202200257. [PMID: 36151769 DOI: 10.1002/jbio.202200257] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/12/2022] [Revised: 09/17/2022] [Accepted: 09/21/2022] [Indexed: 06/16/2023]
Abstract
The efficacy of blue light therapy in dermatology relies on numerous clinical studies. The safety remains a topic of controversy, where potentially deleterious effects were derived from in vitro rather than in vivo experiments. The objectives of this work were (1) to highlight the nuances behind "colors" of blue light, light propagation in tissue and the plurality of modes of action; and (2) to rigorously analyze studies on humans reporting both clinical and histological data from skin biopsies with focus on DNA damage, proliferation, apoptosis, oxidative stress, impact on collagen, elastin, immune cells, and pigmentation. We conclude that blue light therapy is safe for human skin. It induces intriguing skin pigmentation, in part mediated by photoreceptor Opsin-3, which might have a photoprotective effect against ultraviolet irradiation. Future research needs to unravel photochemical reactions and the most effective and safe parameters of blue light in dermatology.
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Affiliation(s)
| | - Desmond J Tobin
- Charles Institute of Dermatology, University College Dublin, Dublin, Ireland
| | - Natalia V Botchkareva
- Department of Dermatology, Boston University School of Medicine, Boston, Massachusetts, USA
| | - Christine Dierickx
- Skinperium Laser and Cosmetic Dermatology Clinic, Skinperium, Luxembourg City, Luxembourg
| | - Peter Bjerring
- Dermatology Department, Aalborg University Hospital, Aalborg, Denmark
| | - Godfrey Town
- Dermatology Department, Aalborg University Hospital, Aalborg, Denmark
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5
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Jadeja SD, Tobin DJ. Autoantigen Discovery in the Hair Loss Disorder, Alopecia Areata: Implication of Post-Translational Modifications. Front Immunol 2022; 13:890027. [PMID: 35720384 PMCID: PMC9205194 DOI: 10.3389/fimmu.2022.890027] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2022] [Accepted: 04/21/2022] [Indexed: 12/24/2022] Open
Abstract
Alopecia areata (AA) is a chronic, multifactorial, polygenic, and heterogeneous disorder affecting growing hair follicles in susceptible individuals, which results in a non-scarring and reversible hair loss with a highly unpredictable course. Despite very considerable research effort, the nature of the precipitating factor(s) responsible for initiating AA in any given hair follicle remains unclear, due largely to significant gaps in our knowledge of the precise sequence of the etiopathogenic events in this dermatosis. However, disease-related changes in the immune-competence of the lower growing hair follicle, together with an active immune response (humoral and cellular) to hair follicle-associated antigens, are key associated phenomena. Confirmation of the hair follicle antigen(s) implicated in AA disease onset has remained stubbornly elusive. While it may be considered somewhat philosophical by some, it is also unclear whether immune-mediated hair loss in AA results from a) an ectopic (i.e., in an abnormal location) immune response to native (unmodified) self-antigens expressed by the healthy hair follicle, b) a normal immune response against modified self-antigens (or neoantigens), or c) a normal immune response against self-antigens (modified/non-modified) that were not previously visible to the immune system (because they were conformationally-hidden or sequestered) but become exposed and presentable in an MHC-I/-II molecule-restricted manner. While some candidate hair follicle antigen target(s) in AA are beginning to emerge, with a potential role for trichohyalin, it is not yet clear whether this represents the initial and immunodominant antigenic focus in AA or is simply one of an expanding repertoire of exposed hair follicle tissue damage-associated antigens that are secondary to the disease. Confirmation of autoantigen identity is essential for our understanding of AA etiopathogenesis, and consequently for developing a more informed therapeutic strategy. Major strides have been made in autoantigen discovery in other autoimmune conditions. In particular, some of these conditions may provide insights into how post-translational modifications (e.g., citrullination, deamidation, etc.) of hair follicle-restricted proteins may increase their antigenicity and so help drive the anti-hair follicle immune attack in AA.
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Affiliation(s)
- Shahnawaz D. Jadeja
- The Charles Institute of Dermatology, School of Medicine, University College Dublin, Dublin, Ireland
| | - Desmond J. Tobin
- The Charles Institute of Dermatology, School of Medicine, University College Dublin, Dublin, Ireland
- The Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Dublin, Ireland
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6
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Casalou C, Moreiras H, Mayatra JM, Fabre A, Tobin DJ. Loss of 'Epidermal Melanin Unit' Integrity in Human Skin During Melanoma-Genesis. Front Oncol 2022; 12:878336. [PMID: 35574390 PMCID: PMC9097079 DOI: 10.3389/fonc.2022.878336] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2022] [Accepted: 03/09/2022] [Indexed: 12/13/2022] Open
Abstract
Cutaneous melanoma can be a most challenging neoplasm of high lethality, in part due to its extreme heterogeneity and characteristic aggressive and invasive nature. Indeed, its moniker 'the great masquerader' reflects that not all melanomas are created equal in terms of their originating cellular contexts, but also that melanoma cells in the malignant tumor can adopt a wide range of different cell states and variable organotropism. In this review, we focus on the early phases of melanomagenesis by discussing how the originating pigment cell of the melanocyte lineage can be influenced to embark on a wide range of tumor fates with distinctive microanatomical pathways. In particular, we assess how cells of the melanocyte lineage can differ by maturation status (stem cell; melanoblast; transiently amplifying cell; differentiated; post-mitotic; terminally-differentiated) as well as by micro-environmental niche (in the stratum basale of the epidermis; within skin appendages like hair follicle, eccrine gland, etc). We discuss how the above variable contexts may influence the susceptibility of the epidermal-melanin unit (EMU) to become unstable, which may presage cutaneous melanoma development. We also assess how unique features of follicular-melanin unit(s) (FMUs) can, by contrast, protect melanocytes from melanomagenesis. Lastly, we postulate how variable melanocyte fates in vitiligo, albinism, psoriasis, and alopecia areata may provide new insights into immune-/non immune-mediated outcomes for melanocytes in cutaneous melanin units.
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Affiliation(s)
- Cristina Casalou
- The Charles Institute of Dermatology, School of Medicine, University College Dublin, Dublin, Ireland
| | - Hugo Moreiras
- The Charles Institute of Dermatology, School of Medicine, University College Dublin, Dublin, Ireland
| | - Jay M Mayatra
- The Charles Institute of Dermatology, School of Medicine, University College Dublin, Dublin, Ireland
| | - Aurelie Fabre
- Department of Histopathology, St Vincent's University Hospital, Dublin, Ireland.,UCD School of Medicine, University College Dublin, Dublin, Ireland.,The Conway Institute of Biomedical and Biomolecular Science, University College Dublin, Dublin, Ireland
| | - Desmond J Tobin
- The Charles Institute of Dermatology, School of Medicine, University College Dublin, Dublin, Ireland.,The Conway Institute of Biomedical and Biomolecular Science, University College Dublin, Dublin, Ireland
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7
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Casalou C, Tobin DJ. Modulating mucins makes melanin. Br J Dermatol 2021; 186:388-389. [PMID: 34817869 DOI: 10.1111/bjd.20877] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2021] [Accepted: 10/22/2021] [Indexed: 11/30/2022]
Affiliation(s)
- C Casalou
- The Charles Institute of Dermatology, School of Medicine, University College Dublin, D04 V1W8, Dublin, Ireland
| | - D J Tobin
- The Charles Institute of Dermatology, School of Medicine, University College Dublin, D04 V1W8, Dublin, Ireland.,The Conway Institute of Biomolecular and Biomedical Research, University College Dublin, D04 V1W8, Dublin, Ireland
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8
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Shu W, Heimark H, Bertollo N, Tobin DJ, O'Cearbhaill ED, Annaidh AN. Insights into the mechanics of solid conical microneedle array insertion into skin using the finite element method. Acta Biomater 2021; 135:403-413. [PMID: 34492370 DOI: 10.1016/j.actbio.2021.08.045] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Revised: 08/24/2021] [Accepted: 08/26/2021] [Indexed: 11/16/2022]
Abstract
In order to develop optimum microneedle designs, researchers must first develop robust, repeatable and adaptable test methods which are representative of in vivo conditions. However, there is a lack of experimental tools which can accurately comparatively interrogate functional microneedle penetration of tissue. In this study, we seek to develop a state of the art finite element model of microneedle insertion into and penetration of human skin. The developed model employs a 3D hyperelastic, anisotropic pre-stressed multi-layered material which more accurately reflects in vivo skin conditions, while the microneedle is modeled as an array, which can capture the influence of adjacent microneedles on the overall response. Using the developed finite element model, we highlight the importance of accurate computational modeling which can decipher the mechanics of microneedle insertion, including the influence of its position within an array and how it correlates well with experimental observations. In particular, we have concluded that, for our model microneedle array, increasing skin pretension from 0 to 10% strain reduces the penetration force by 13%, ultimate local deformation about the microneedle by 22% and the ultimate penetration efficiency by 15%. We have also concluded that the presence of a base plate limits the penetration efficiency by up to 24%, while the penetration efficiency across a 5 × 1 microneedle array may vary by 27%. This model elucidates, for the first time, the combined effects of skin tension and needle geometry on accurately predicting microneedle penetration efficiency. STATEMENT OF SIGNIFICANCE: Microneedles arrays (MNAs) are medical devices with microscale protrusions, typically designed to penetrate the outermost layer of the skin, that upon optimisation, could lead to disruptive minimally-invasive disease management. However, the mechanics of MNA insertion are complex, due in part to a 'bed of nails' effect, and difficult to elucidate experimentally. Therefore, comparisons between designs, functional assessment of production batches and ultimately the likelihood of clinical translation are challenging to predict. Here, we have develop the most sophisticated in silico model of MNA insertion into pre-tensioned human skin to predict the extent of MNA penetration and therefore the likelihood of successful therapeutic delivery. Researchers can customise this model to predict the penetration efficiency of any MNA design.
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Affiliation(s)
- Wenting Shu
- UCD Centre for Biomedical Engineering, University College Dublin, Belfield Dublin 4, Ireland; School of Mechanical & Materials Engineering, University College Dublin, Belfield Dublin 4, Ireland
| | - Helen Heimark
- UCD Centre for Biomedical Engineering, University College Dublin, Belfield Dublin 4, Ireland; School of Mechanical & Materials Engineering, University College Dublin, Belfield Dublin 4, Ireland
| | - Nicky Bertollo
- UCD Centre for Biomedical Engineering, University College Dublin, Belfield Dublin 4, Ireland; School of Mechanical & Materials Engineering, University College Dublin, Belfield Dublin 4, Ireland
| | - Desmond J Tobin
- UCD Charles Institute of Dermatology, School of Medicine, University College Dublin, Belfield Dublin 4, Ireland
| | - Eoin D O'Cearbhaill
- UCD Centre for Biomedical Engineering, University College Dublin, Belfield Dublin 4, Ireland; School of Mechanical & Materials Engineering, University College Dublin, Belfield Dublin 4, Ireland; UCD Charles Institute of Dermatology, School of Medicine, University College Dublin, Belfield Dublin 4, Ireland; The Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Dublin, Ireland.
| | - Aisling Ní Annaidh
- UCD Centre for Biomedical Engineering, University College Dublin, Belfield Dublin 4, Ireland; School of Mechanical & Materials Engineering, University College Dublin, Belfield Dublin 4, Ireland; UCD Charles Institute of Dermatology, School of Medicine, University College Dublin, Belfield Dublin 4, Ireland.
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9
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Wall D, Alhusayen R, Arents B, Apfelbacher C, Balogh EA, Bokhari L, Bloem M, Bosma AL, Burton T, Castelo-Soccio L, Fagan N, Feldman SR, Fletcher G, Flohr C, Freeman E, French LE, Griffiths CEM, Hruza GJ, Ingram JR, Kappelman MD, Lara-Corrales I, Lim HW, Meah N, McMahon DE, Mahil SK, McNicoll I, Musters A, Naik HB, Sinclair R, Smith CH, Spuls P, Tobin DJ, York K, Irvine AD. Learning from disease registries during a pandemic: Moving toward an international federation of patient registries. Clin Dermatol 2021; 39:467-478. [PMID: 34518006 PMCID: PMC8432911 DOI: 10.1016/j.clindermatol.2021.01.018] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
High-quality dermatology patient registries often require considerable time to develop and produce meaningful data. Development time is influenced by registry complexity and regulatory hurdles that vary significantly nationally and institutionally. The rapid emergence of the coronavirus disease 2019 (COVID-19) global pandemic has challenged health services in an unprecedented manner. Mobilization of the dermatology community in response has included rapid development and deployment of multiple, partially harmonized, international patient registries, reinventing established patient registry timelines. Partnership with patient organizations has demonstrated the critical nature of inclusive patient involvement. This global effort has demonstrated the value, capacity, and necessity for the dermatology community to adopt a more cohesive approach to patient registry development and data sharing that can lead to myriad benefits. These include improved utilization of limited resources, increased data interoperability, improved ability to rapidly collect meaningful data, and shortened response times to generate real-world evidence. We call on the global dermatology community to support the development of an international federation of patient registries to consolidate and operationalize the lessons learned during this pandemic. This will provide an enduring means of applying this knowledge to the maintenance and development of sustainable, coherent, and impactful patient registries of benefit now and in the future.
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Affiliation(s)
- Dmitri Wall
- Hair Restoration Blackrock, Dublin, Ireland; National and International Skin Registry Solutions (NISR), Charles Institute of Dermatology, University College Dublin, Dublin, Ireland; School of Medicine, University College Dublin, Dublin, Ireland.
| | - Raed Alhusayen
- Division of Dermatology and Sunnybrook Research Institute, University of Toronto, Ontario, Canada
| | - Bernd Arents
- Dutch Association for People with Atopic Dermatitis, Nijkerk, the Netherlands
| | - Christian Apfelbacher
- Institute of Social Medicine and Health Systems Research, Medical Faculty, Otto von Guericke University Magdeburg, Magdeburg, Germany; Family Medicine and Primary Care, Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore
| | - Esther A Balogh
- Center for Dermatology Research, Department of Dermatology, Wake Forest School of Medicine, Winston Salem, North Carolina, USA
| | | | - Manja Bloem
- Department of Dermatology, Academic Medical Center, University of Amsterdam, Amsterdam Public Health, Infection and Immunity, Amsterdam, The Netherlands
| | - Angela L Bosma
- Department of Dermatology, Academic Medical Center, University of Amsterdam, Amsterdam Public Health, Infection and Immunity, Amsterdam, The Netherlands
| | | | - Leslie Castelo-Soccio
- Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA; University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, USA
| | - Nicole Fagan
- University of Dublin, Trinity College, Dublin, Ireland
| | - Steven R Feldman
- Center for Dermatology Research, Department of Dermatology, Wake Forest School of Medicine, Winston Salem, North Carolina, USA
| | - Godfrey Fletcher
- National and International Skin Registry Solutions (NISR), Charles Institute of Dermatology, University College Dublin, Dublin, Ireland
| | - Carsten Flohr
- Unit for Population-Based Dermatology Research, St John's Institute of Dermatology, Guy's and St Thomas' NHS Foundation Trust and King's College London, London, UK
| | - Esther Freeman
- Massachusetts General Hospital Department of Dermatology, Harvard Medical School, Boston, Massachusetts, USA
| | - Lars E French
- Department of Dermatology, University Hospital, Munich University of Ludwig Maximilian, Munich, Germany
| | - Christopher E M Griffiths
- Dermatology Centre, The University of Manchester and NIHR Manchester Biomedical Research Centre, Manchester, UK
| | - George J Hruza
- St. Louis University Department of Dermatology, St. Louis, Missouri, USA
| | - John R Ingram
- Department of Dermatology, Division of Infection & Immunity, Cardiff University, Cardiff, UK
| | - Michael D Kappelman
- Department of Pediatrics, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Irene Lara-Corrales
- Section of Dermatology, Hospital for Sick Children, Toronto, Ontario, Canada
| | - Henry W Lim
- Department of Dermatology, Henry Ford Health System, Detroit, Michigan, USA
| | - Nekma Meah
- Sinclair Dermatology, Melbourne, Australia
| | - Devon E McMahon
- Massachusetts General Hospital Department of Dermatology, Harvard Medical School, Boston, Massachusetts, USA
| | - Satveer K Mahil
- St John's Institute of Dermatology, Guy's and St Thomas' NHS Foundation Trust and King's College London, London, UK
| | - Ian McNicoll
- Centre for Health Informatics and Multiprofessional Education (CHIME), University College London, London, UK
| | - Annelie Musters
- Department of Dermatology, Academic Medical Center, University of Amsterdam, Amsterdam Public Health, Infection and Immunity, Amsterdam, The Netherlands
| | - Haley B Naik
- Department of Dermatology, University of California, San Francisco, San Francisco, California, USA
| | | | - Catherine H Smith
- St John's Institute of Dermatology, Guy's and St Thomas' NHS Foundation Trust and King's College London, London, UK
| | - Phyllis Spuls
- Department of Dermatology, Academic Medical Center, University of Amsterdam, Amsterdam Public Health, Infection and Immunity, Amsterdam, The Netherlands
| | - Desmond J Tobin
- The Charles Institute of Dermatology, School of Medicine, University College Dublin, Belfield, Dublin, Ireland
| | - Katherine York
- Netcare Greenacres Hospital, Port Elizabeth, South Africa
| | - Alan D Irvine
- National and International Skin Registry Solutions (NISR), Charles Institute of Dermatology, University College Dublin, Dublin, Ireland; Clinical Medicine, Trinity College, Dublin, Ireland
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10
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Wall D, Meah N, York K, Bhoyrul B, Bokhari L, Abraham LS, Adams R, Bergfeld W, Betz RC, Blume-Peytavi U, Callender V, Campbell C, Chambers J, Chen G, Chitreddy V, Cotsarelis G, Craiglow B, Dhurat R, Dlova N, Donovan J, Duque-Estrada B, Eisman S, Ellison A, Farrant P, Barberá JF, Gadzhigoroeva A, Grimalt R, Harries M, Hordinsky M, Irvine AD, Jolliffe V, Jones L, King B, Lee WS, Lortkipanidze N, McMichael A, Messenger A, Mirmirani P, Olsen E, Orlow SJ, Ovcharenko Y, Piraccini BM, Pirmez R, Rakowska A, Reygagne P, Riley M, Rudnicka L, Saceda Corralo D, Shapiro J, Sharma P, Silyuk T, Kaiumov S, Tobin DJ, Tosti A, Vañó-Galván S, Vogt A, Wade M, Yip L, Zlotogorski A, Zhou C, Sinclair R. A Global eDelphi Exercise to Identify Core Domains and Domain Items for the Development of a Global Registry of Alopecia Areata Disease Severity and Treatment Safety (GRASS). JAMA Dermatol 2021; 157:1-11. [PMID: 33656556 DOI: 10.1001/jamadermatol.2020.5839] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Importance A recent expert consensus exercise emphasized the importance of developing a global network of patient registries for alopecia areata to redress the paucity of comparable, real-world data regarding the effectiveness and safety of existing and emerging therapies for alopecia areata. Objective To generate core domains and domain items for a global network of alopecia areata patient registries. Evidence Review Sixty-six participants, representing physicians, patient organizations, scientists, the pharmaceutical industry, and pharmacoeconomic experts, participated in a 3-round eDelphi process, culminating in a face-to-face meeting at the World Congress of Dermatology, Milan, Italy, June 14, 2019. Findings Ninety-two core data items, across 25 domains, achieved consensus agreement. Twenty further noncore items were retained to facilitate data harmonization in centers that wish to record them. Broad representation across multiple stakeholder groups was sought; however, the opinion of physicians was overrepresented. Conclusions and Relevance This study identifies the domains and domain items required to develop a global network of alopecia areata registries. These domains will facilitate a standardized approach that will enable the recording of a comprehensive, comparable data set required to oversee the introduction of new therapies and harness real-world evidence from existing therapies at a time when the alopecia areata treatment paradigm is being radically and positively disrupted. Reuse of similar, existing frameworks in atopic dermatitis, produced by the Treatment of Atopic Eczema (TREAT) Registry Taskforce, increases the potential to reuse existing resources, creates opportunities for comparison of data across dermatology subspecialty disease areas, and supports the concept of data harmonization.
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Affiliation(s)
- Dmitri Wall
- Hair Restoration Blackrock, Dublin, Ireland.,National and International Skin Registry Solutions (NISR), Charles Institute of Dermatology, University College Dublin, Dublin, Ireland.,Sinclair Dermatology, Melbourne, Australia
| | - Nekma Meah
- Sinclair Dermatology, Melbourne, Australia
| | - Katherine York
- Netcare Greenacres Hospital, Port Elizabeth, South Africa
| | | | | | | | - Roisín Adams
- National Centre for Pharmacoeconomics, St James Hospital, Dublin, Ireland
| | | | - Regina C Betz
- Institute of Human Genetics, University of Bonn, School of Medicine and University Hospital Bonn, Bonn, Germany
| | - Ulrike Blume-Peytavi
- Department of Dermatology, Venerology and Allergology, Clinical Research Center for Hair and Skin Science, Charité-Universitaetsmedizin Berlin, Berlin, Germany
| | | | - Chel Campbell
- Australia Alopecia Areata Foundation Inc, Frankston, Australia
| | | | - Gang Chen
- Centre for Health Economics, Monash University, Melbourne, Australia
| | | | - George Cotsarelis
- Department of Dermatology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia
| | - Brittany Craiglow
- Dermatology Physicians of Connecticut, Fairfield.,Department of Dermatology, Yale University, New Haven, Connecticut
| | - Rachita Dhurat
- Department of Dermatology, LTM Medical College and Hospital Sion, Mumbai, India
| | - Ncoza Dlova
- Department of Dermatology, Nelson R Mandela School of Medicine, Durban, South Africa.,School of Clinical Medicine, University of KwaZulu Natal, Durban, South Africa
| | - Jeff Donovan
- Department of Dermatology, University of British Columbia, Vancouver, British Columbia, Canada.,Donovan Hair Clinic, Whistler, British Columbia, Canada
| | | | | | - Abby Ellison
- National Alopecia Areata Foundation, San Rafael, California
| | - Paul Farrant
- Brighton and Sussex University Hospitals NHS (National Health Service) Trust, Brighton, United Kingdom
| | - Juan Ferrando Barberá
- Instituto Clínic de Medicina y Dermatología, Hospital Clínic de Barcelona, University of Barcelona, Barcelona, Spain
| | - Aida Gadzhigoroeva
- Scientific and Practical Center Dermatolovenereology and Cosmetology of the Moscow City Health Department, Moscow, Russian Federation
| | - Ramon Grimalt
- Facultat de Medicina i Ciències de la Salut, Universitat Internacional de Catalunya, Barcelona, Spain
| | - Matthew Harries
- Centre for Dermatology Research, University of Manchester, Manchester Academic Health Science Centre and National Institute for Health Research Manchester Biomedical Research Centre, Manchester, United Kingdom.,The Dermatology Centre, Salford Royal NHS Foundation Trust, Salford, Manchester, United Kingdom
| | - Maria Hordinsky
- Department of Dermatology, University of Minnesota, Minneapolis
| | - Alan D Irvine
- Clinical Medicine, Trinity College Dublin, Dublin, Ireland
| | - Victoria Jolliffe
- Centre for Cell Biology and Cutaneous Research, Blizard Institute, London, United Kingdom
| | | | - Brett King
- Yale School of Medicine, New Haven, Connecticut
| | - Won-Soo Lee
- Department of Dermatology, Yonsei Wonju University, Wonju, Korea
| | - Nino Lortkipanidze
- Department of Dermatology and Venereology, David Tvildiani Medical University, Tbilisi, Republic of Georgia
| | - Amy McMichael
- Department of Dermatology, Wake Forest University School of Medicine, Winston-Salem, North Carolina
| | - Andrew Messenger
- Department of Infection, Immunity and Cardiovascular Disease, University of Sheffield, Sheffield, United Kingdom
| | - Paradi Mirmirani
- Department of Dermatology, Kaiser Permanente Vallejo, Vallejo, California
| | - Elise Olsen
- Duke Dermatology Clinic, Durham, North Carolina
| | - Seth J Orlow
- The Ronald O. Perelman Department of Dermatology, New York University School of Medicine, New York, New York.,Department of Pediatrics, New York University Medical Center, New York, New York
| | - Yuliya Ovcharenko
- Department of General and Clinical Immunology and Allergology, V. N. Karazin Kharkiv National University, Kharkiv, Ukraine
| | - Bianca Maria Piraccini
- Department of Experimental, Diagnostic and Specialty Medicine, Alma Mater Studiorum University of Bologna, Bologna, Italy
| | - Rodrigo Pirmez
- Instituto de Dermatologia Professor Rubem David Azulay, Santa Casa da Misericórdia do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Adriana Rakowska
- Department of Dermatology, Medical University of Warsaw, Warsaw, Poland
| | - Pascal Reygagne
- Centre de Santé Sabouraud, Hopital Saint Louis, Vellefaux, Paris, France
| | - Melissa Riley
- Canadian Alopecia Areata Foundation, King City, Ontario, Canada
| | - Lidia Rudnicka
- Department of Dermatology, Medical University of Warsaw, Warsaw, Poland
| | - David Saceda Corralo
- Dermatology Department, Hospital Universitario Ramón y Cajal, Instituto Ramón y Cajal de Investigación Sanitaria, Universidad de Alcalá, Madrid, Spain
| | - Jerry Shapiro
- Disorders of the Hair and Scalp, The Ronald O. Perelman Department of Dermatology, New York University School of Medicine, New York, New York
| | | | - Tatiana Silyuk
- Hair Treatment and Transplantation Center, Saint Petersburg, Russian Federation
| | | | - Desmond J Tobin
- The Charles Institute of Dermatology, School of Medicine, University College Dublin, Belfield, Dublin, Ireland
| | - Antonella Tosti
- Dr Phillip Frost Department of Dermatology and Cutaneous Surgery, University of Miami, Miller School of Medicine, Miami, Florida
| | - Sergio Vañó-Galván
- Dermatology Department, Hospital Universitario Ramón y Cajal, Instituto Ramón y Cajal de Investigación Sanitaria, Universidad de Alcalá, Madrid, Spain.,Trichology Unit, #TricoHRC Research Group, Madrid, Spain
| | - Annika Vogt
- Department of Dermatology, Venerology and Allergology, Clinical Research Center for Hair and Skin Science, Charité-Universitaetsmedizin Berlin, Berlin, Germany
| | - Martin Wade
- The London Skin and Hair Clinic, London, United Kingdom
| | - Leona Yip
- Skin Partners Specialist Dermatologists, Brisbane, Australia
| | - Abraham Zlotogorski
- Department of Dermatology, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - Cheng Zhou
- Department of Dermatology, Peking University People's Hospital, Beijing, China
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11
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Johnston DGW, Kirby B, Tobin DJ. Hidradenitis suppurativa: A folliculotropic disease of innate immune barrier dysfunction? Exp Dermatol 2021; 30:1554-1568. [PMID: 34418166 DOI: 10.1111/exd.14451] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2021] [Revised: 08/18/2021] [Accepted: 08/20/2021] [Indexed: 12/11/2022]
Abstract
The innate immune system of human skin consists of a multi-layered barrier consisting of cells and soluble effector molecules charged with maintaining homeostasis and responding to insults and infections. It has become increasingly clear that these barrier layers become compromised in skin diseases, especially in disorders of an (auto)inflammatory nature. In the case of hidradenitis suppurativa, great strides have been made in recent years in characterizing the underlying breakdown in homeostatic innate immunity, including an increasing understanding of the central role of the hair follicle in this process. This breakdown appears to occur at multiple levels: the pilosebaceous unit, associated epithelium, the cutaneous microbiome, alteration of immune cell function and local molecular events such as complement activation. This review seeks to summarize, contextualize and analyse critically our current understanding of how these innate immune barriers become dysregulated in the early stage(s) of hidradenitis suppurativa, and to speculate on where potential hidradenitis suppurativa research could be most fruitful.
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Affiliation(s)
- Daniel G W Johnston
- The Charles Institute of Dermatology, School of Medicine, University College Dublin, Dublin 4, Ireland
| | - Brian Kirby
- The Charles Institute of Dermatology, School of Medicine, University College Dublin, Dublin 4, Ireland.,Charles Department of Dermatology, St Vincent's University Hospital, Dublin, Ireland
| | - Desmond J Tobin
- The Charles Institute of Dermatology, School of Medicine, University College Dublin, Dublin 4, Ireland.,The Conway Institute, University College Dublin, Dublin 4, Ireland
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12
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Rosenberg AM, Rausser S, Ren J, Mosharov EV, Sturm G, Ogden RT, Patel P, Kumar Soni R, Lacefield C, Tobin DJ, Paus R, Picard M. Quantitative mapping of human hair greying and reversal in relation to life stress. eLife 2021; 10:67437. [PMID: 34155974 PMCID: PMC8219384 DOI: 10.7554/elife.67437] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Accepted: 05/12/2021] [Indexed: 12/12/2022] Open
Abstract
Background: Hair greying is a hallmark of aging generally believed to be irreversible and linked to psychological stress. Methods: Here, we develop an approach to profile hair pigmentation patterns (HPPs) along individual human hair shafts, producing quantifiable physical timescales of rapid greying transitions. Results: Using this method, we show white/grey hairs that naturally regain pigmentation across sex, ethnicities, ages, and body regions, thereby quantitatively defining the reversibility of greying in humans. Molecularly, grey hairs upregulate proteins related to energy metabolism, mitochondria, and antioxidant defenses. Combining HPP profiling and proteomics on single hairs, we also report hair greying and reversal that can occur in parallel with psychological stressors. To generalize these observations, we develop a computational simulation, which suggests a threshold-based mechanism for the temporary reversibility of greying. Conclusions: Overall, this new method to quantitatively map recent life history in HPPs provides an opportunity to longitudinally examine the influence of recent life exposures on human biology. Funding: This work was supported by the Wharton Fund and NIH grants GM119793, MH119336, and AG066828 (MP). Hair greying is a visible sign of aging that affects everyone. The loss of hair color is due to the loss of melanin, a pigment found in the skin, eyes and hair. Research in mice suggests stress may accelerate hair greying, but there is no definitive research on this in humans. This is because there are no research tools to precisely map stress and hair color over time. But, just like tree rings hold information about past decades, and rocks hold information about past centuries, hairs hold information about past months and years. Hair growth is an active process that happens under the skin inside hair follicles. It demands lots of energy, supplied by structures inside cells called mitochondria. While hairs are growing, cells receive chemical and electrical signals from inside the body, including stress hormones. It is possible that these exposures change proteins and other molecules laid down in the growing hair shaft. As the hair grows out of the scalp, it hardens, preserving these molecules into a stable form. This preservation is visible as patterns of pigmentation. Examining single-hairs and matching the patterns to life events could allow researchers to look back in time through a person’s biological history. Rosenberg et al. report a new way to digitize and measure small changes in color along single human hairs. This method revealed that some white hairs naturally regain their color, something that had not been reported in a cohort of healthy individuals before. Aligning the hair pigmentation patterns with recent reports of stress in the hair donors’ lives showed striking associations. When one donor reported an increase in stress, a hair lost its pigment. When the donor reported a reduction in stress, the same hair regained its pigment. Rosenberg et al. mapped hundreds of proteins inside the hairs to show that white hairs contained more proteins linked to mitochondria and energy use. This suggests that metabolism and mitochondria may play a role in hair greying. To explore these observations in more detail Rosenberg et al. developed a mathematical model that simulates the greying of a whole head of hair over a lifetime, an experiment impossible to do with living people. The model suggested that there might be a threshold for temporary greying; if hairs are about to go grey anyway, a stressful event might trigger that change earlier. And when the stressful event ends, if a hair is just above the threshold, then it could revert back to dark. The new method for measuring small changes in hair coloring opens up the possibility of using hair pigmentation patterns like tree rings. This could track the influence of past life events on human biology. In the future, monitoring hair pigmentation patterns could provide a way to trace the effectiveness of treatments aimed at reducing stress or slowing the aging process. Understanding how ‘old’ white hairs regain their ‘young’ pigmented state could also reveal new information about the malleability of human aging more generally.
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Affiliation(s)
- Ayelet M Rosenberg
- Department of Psychiatry, Division of Behavioral Medicine, Columbia University Irving Medical Center, New York, United States
| | - Shannon Rausser
- Department of Psychiatry, Division of Behavioral Medicine, Columbia University Irving Medical Center, New York, United States
| | - Junting Ren
- Department of Biostatistics, Mailman School of Public Health, Columbia University Irving Medical Center, New York, United States
| | - Eugene V Mosharov
- Department of Psychiatry, Division of Molecular Therapeutics, Columbia University Irving Medical Center, New York, United States.,New York State Psychiatric Institute, New York, United States
| | - Gabriel Sturm
- Department of Psychiatry, Division of Behavioral Medicine, Columbia University Irving Medical Center, New York, United States
| | - R Todd Ogden
- Department of Biostatistics, Mailman School of Public Health, Columbia University Irving Medical Center, New York, United States
| | - Purvi Patel
- Proteomics and Macromolecular Crystallography Shared Resource, Columbia University Irving Medical Center, New York, United States
| | - Rajesh Kumar Soni
- Proteomics and Macromolecular Crystallography Shared Resource, Columbia University Irving Medical Center, New York, United States
| | - Clay Lacefield
- New York State Psychiatric Institute, New York, United States
| | - Desmond J Tobin
- UCD Charles Institute of Dermatology & UCD Conway Institute, School of Medicine, University College Dublin, Dublin, Ireland
| | - Ralf Paus
- Dr. Phillip Frost Department of Dermatology & Cutaneous Surgery, University of Miami Miller School of Medicine, Miami, United States.,Centre for Dermatology Research, University of Manchester, Manchester, United Kingdom.,Monasterium Laboratory, Münster, Germany
| | - Martin Picard
- Department of Psychiatry, Division of Behavioral Medicine, Columbia University Irving Medical Center, New York, United States.,New York State Psychiatric Institute, New York, United States.,Department of Neurology, H. Houston Merritt Center, Columbia Translational Neuroscience Initiative, Columbia University Irving Medical Center, New York, United States
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13
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Moreiras H, O'Connor C, Bell M, Tobin DJ. Visible light and human skin pigmentation: The importance of skin phototype. Exp Dermatol 2021; 30:1324-1331. [PMID: 34081365 DOI: 10.1111/exd.14400] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2021] [Revised: 04/27/2021] [Accepted: 05/13/2021] [Indexed: 12/22/2022]
Abstract
Melanin is synthesised within melanocytes and transferred to keratinocytes in human skin, thereby regulating skin colour and protecting skin cells against UVR-induced damage. We commonly divide human skin into six phototypes (SPT)-I to -VI (Fitzpatrick scale) according to the skin's tanning response to UVR. In this pilot study, we investigated the impact of UVR (maximum 311nm), blue (peak 450nm) and green visible light (peak 530nm) on melanin production and type in healthy human skin histocultures (SPT-I, -II and -III). UVR, blue and green light stimulated a surface tanning response in SPT-II and -III, but not SPT-I. Using the Warthin-Starry stain for sensitive melanin detection, all three light treatments induced melanogenesis in SPT-II and -III skin. Surprisingly, blue and green light (but not UVR) stimulated melanin synthesis in SPT-I skin. Moreover, melanin synthesis induced by blue and green visible light in SPT-I, SPT-II, and SPT-III skin was not associated with a detectable increase in DNA damage or cell apoptosis. By contrast, both responses were detected after UVR. These data suggest that blue and green visible light can stimulate melanin production in fair-skinned individuals without, at least some of, the harmful consequences of UVR-induced pigmentation. We are currently examining the molecular basis of UVR-independent melanogenesis in fair skin.
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Affiliation(s)
- Hugo Moreiras
- The Charles Institute of Dermatology, School of Medicine, University College Dublin, Dublin, Ireland
| | | | - Mike Bell
- Walgreens Boots Alliance, Nottingham, UK
| | - Desmond J Tobin
- The Charles Institute of Dermatology, School of Medicine, University College Dublin, Dublin, Ireland.,The Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Dublin, Ireland
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14
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Chen Y, André M, Adhikari K, Blin M, Bonfante B, Mendoza-Revilla J, Fuentes-Guajardo M, Palmal S, Chacón-Duque JC, Hurtado M, Villegas V, Granja V, Jaramillo C, Arias W, Lozano RB, Everardo-Martínez P, Gómez-Valdés J, Villamil-Ramírez H, de Cerqueira CCS, Hünemeier T, Ramallo V, Gonzalez-José R, Schüler-Faccini L, Bortolini MC, Acuña-Alonzo V, Canizales-Quinteros S, Gallo C, Poletti G, Bedoya G, Rothhammer F, Balding D, Tobin DJ, Wang S, Faux P, Ruiz-Linares A. A genome-wide association study identifies novel gene associations with facial skin wrinkling and mole count in Latin Americans. Br J Dermatol 2021; 185:988-998. [PMID: 33959940 DOI: 10.1111/bjd.20436] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/04/2021] [Indexed: 12/01/2022]
Abstract
BACKGROUND Genome-wide association studies (GWASs) have identified genes influencing skin ageing and mole count in Europeans, but little is known about the relevance of these (or other genes) in non-Europeans. OBJECTIVES To conduct a GWAS for facial skin ageing and mole count in adults < 40 years old, of mixed European, Native American and African ancestry, recruited in Latin America. METHODS Skin ageing and mole count scores were obtained from facial photographs of over 6000 individuals. After quality control checks, three wrinkling traits and mole count were retained for genetic analyses. DNA samples were genotyped with Illumina's HumanOmniExpress chip. Association testing was performed on around 8 703 729 single-nucleotide polymorphisms (SNPs) across the autosomal genome. RESULTS Genome-wide significant association was observed at four genome regions: two were associated with wrinkling (in 1p13·3 and 21q21·2), one with mole count (in 1q32·3) and one with both wrinkling and mole count (in 5p13·2). Associated SNPs in 5p13·2 and in 1p13·3 are intronic within SLC45A2 and VAV3, respectively, while SNPs in 1q32·3 are near the SLC30A1 gene, and those in 21q21·2 occur in a gene desert. Analyses of SNPs in IRF4 and MC1R are consistent with a role of these genes in skin ageing. CONCLUSIONS We replicate the association of wrinkling with variants in SLC45A2, IRF4 and MC1R reported in Europeans. We identify VAV3 and SLC30A1 as two novel candidate genes impacting on wrinkling and mole count, respectively. We provide the first evidence that SLC45A2 influences mole count, in addition to variants in this gene affecting melanoma risk in Europeans.
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Affiliation(s)
- Y Chen
- Ministry of Education Key Laboratory of Contemporary Anthropology and Collaborative Innovation Center of Genetics and Development, School of Life Sciences and Human Phenome Institute, Fudan University, Yangpu District, Shanghai, China
| | - M André
- UMR 7268 ADES, CNRS, Aix-Marseille Université, EFS, Faculté de Médecine Timone, Marseille, 13005, France.,Estonian Biocentre, Institute of Genomics, University of Tartu, Tartu, 51010, Estonia
| | - K Adhikari
- School of Mathematics and Statistics, Faculty of Science, Technology, Engineering and Mathematics, The Open University, Milton Keynes, MK7 6AA, UK.,Department of Genetics, Evolution and Environment, and UCL Genetics Institute, University College London, London, WC1E 6BT, UK
| | - M Blin
- UMR 7268 ADES, CNRS, Aix-Marseille Université, EFS, Faculté de Médecine Timone, Marseille, 13005, France
| | - B Bonfante
- UMR 7268 ADES, CNRS, Aix-Marseille Université, EFS, Faculté de Médecine Timone, Marseille, 13005, France
| | - J Mendoza-Revilla
- Laboratorios de Investigación y Desarrollo, Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia, Lima 31, Perú.,Unit of Human Evolutionary Genetics, Institut Pasteur, Paris, 75015, France
| | - M Fuentes-Guajardo
- Departamento de Tecnología Médica, Facultad de Ciencias de la Salud, Universidad de Tarapacá, Arica, 1000000, Chile
| | - S Palmal
- UMR 7268 ADES, CNRS, Aix-Marseille Université, EFS, Faculté de Médecine Timone, Marseille, 13005, France
| | - J C Chacón-Duque
- Division of Vertebrates and Anthropology, Department of Earth Sciences, Natural History Museum, London, SW7 5BD, UK
| | - M Hurtado
- Laboratorios de Investigación y Desarrollo, Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia, Lima 31, Perú
| | - V Villegas
- Laboratorios de Investigación y Desarrollo, Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia, Lima 31, Perú
| | - V Granja
- Laboratorios de Investigación y Desarrollo, Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia, Lima 31, Perú
| | - C Jaramillo
- GENMOL (Genética Molecular), Universidad de Antioquia, Medellín, 5001000, Colombia
| | - W Arias
- GENMOL (Genética Molecular), Universidad de Antioquia, Medellín, 5001000, Colombia
| | - R B Lozano
- National Institute of Anthropology and History, Mexico City, MC, 6600, Mexico.,Department of Archaeogenetics, Max Planck Institute for the Science of Human History (MPI-SHH), Jena, 07745, Germany
| | - P Everardo-Martínez
- National Institute of Anthropology and History, Mexico City, MC, 6600, Mexico
| | - J Gómez-Valdés
- National Institute of Anthropology and History, Mexico City, MC, 6600, Mexico
| | - H Villamil-Ramírez
- Unidad de Genomica de Poblaciones Aplicada a la Salud, Facultad de Química, UNAM-Instituto Nacional de Medicina Genómica, Mexico City, MC, 4510, Mexico
| | | | - T Hünemeier
- Departamento de Genética e Biologia Evolutiva, Instituto de Biociências, Universidade de São Paulo, São Paulo, SP, 05508-090, Brazil
| | - V Ramallo
- Departamento de Genética, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, 90040-060, Brazil.,Instituto Patagónico de Ciencias Sociales y Humanas, Centro Nacional Patagónico, CONICET, Puerto Madryn, U9129ACD, Argentina
| | - R Gonzalez-José
- Instituto Patagónico de Ciencias Sociales y Humanas, Centro Nacional Patagónico, CONICET, Puerto Madryn, U9129ACD, Argentina
| | - L Schüler-Faccini
- Departamento de Genética, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, 90040-060, Brazil
| | - M-C Bortolini
- Departamento de Genética, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, 90040-060, Brazil
| | - V Acuña-Alonzo
- National Institute of Anthropology and History, Mexico City, MC, 6600, Mexico
| | - S Canizales-Quinteros
- Unidad de Genomica de Poblaciones Aplicada a la Salud, Facultad de Química, UNAM-Instituto Nacional de Medicina Genómica, Mexico City, MC, 4510, Mexico
| | - C Gallo
- Laboratorios de Investigación y Desarrollo, Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia, Lima 31, Perú
| | - G Poletti
- Laboratorios de Investigación y Desarrollo, Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia, Lima 31, Perú
| | - G Bedoya
- GENMOL (Genética Molecular), Universidad de Antioquia, Medellín, 5001000, Colombia
| | - F Rothhammer
- Instituto de Alta Investigación, Universidad de Tarapacá, Arica, 1000000, Chile
| | - D Balding
- Melbourne Integrative Genomics, Schools of BioSciences and Mathematics & Statistics, University of Melbourne, Melbourne, VIC, 3010, Australia
| | - D J Tobin
- The Charles Institute of Dermatology, University College Dublin, Dublin, Ireland
| | - S Wang
- Chinese Academy of Sciences Key Laboratory of Computational Biology, Shanghai Institutes for Biological Sciences, University of the Chinese Academy of Sciences, Shanghai, 200031, China
| | - P Faux
- UMR 7268 ADES, CNRS, Aix-Marseille Université, EFS, Faculté de Médecine Timone, Marseille, 13005, France
| | - A Ruiz-Linares
- Ministry of Education Key Laboratory of Contemporary Anthropology and Collaborative Innovation Center of Genetics and Development, School of Life Sciences and Human Phenome Institute, Fudan University, Yangpu District, Shanghai, China.,UMR 7268 ADES, CNRS, Aix-Marseille Université, EFS, Faculté de Médecine Timone, Marseille, 13005, France.,Department of Genetics, Evolution and Environment, and UCL Genetics Institute, University College London, London, WC1E 6BT, UK
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15
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Tobin DJ. How to design robust assays for human skin pigmentation: A "Tortoise and Hare challenge". Exp Dermatol 2021; 30:624-627. [PMID: 33899266 DOI: 10.1111/exd.14350] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Desmond J Tobin
- The Charles Institute of Dermatology, School of Medicine, University College Dublin, Dublin, Ireland.,The Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Dublin, Ireland
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16
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Castellano-Pellicena I, Morrison CG, Bell M, O’Connor C, Tobin DJ. Melanin Distribution in Human Skin: Influence of Cytoskeletal, Polarity, and Centrosome-Related Machinery of Stratum basale Keratinocytes. Int J Mol Sci 2021; 22:ijms22063143. [PMID: 33808676 PMCID: PMC8003549 DOI: 10.3390/ijms22063143] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2021] [Revised: 03/13/2021] [Accepted: 03/14/2021] [Indexed: 12/12/2022] Open
Abstract
Melanin granules cluster within supra-nuclear caps in basal keratinocytes (KCs) of the human epidermis, where they protect KC genomic DNA against ultraviolet radiation (UVR) damage. While much is known about melanogenesis in melanocytes (MCs) and a moderate amount about melanin transfer from MC to KC, we know little about the fate of melanin once inside KCs. We recently reported that melanin fate in progenitor KCs is regulated by rare asymmetric organelle movement during mitosis. Here, we explore the role of actin, microtubules, and centrosome-associated machinery in distributing melanin within KCs. Short-term cultures of human skin explants were treated with cytochalasin-B and nocodazole to target actin filaments and microtubules, respectively. Treatment effects on melanin distribution were assessed by the Warthin-Starry stain, on centrosome-associated proteins by immunofluorescence microscopy, and on co-localisation with melanin granules by brightfield microscopy. Cytochalasin-B treatment disassembled supra-nuclear melanin caps, while nocodazole treatment moved melanin from the apical to basal KC domain. Centrosome and centriolar satellite-associated proteins showed a high degree of co-localisation with melanin. Thus, once melanin granules are transferred to KCs, their preferred apical distribution appears to be facilitated by coordinated movement of centrosomes and centriolar satellites. This mechanism may control melanin's strategic position within UVR-exposed KCs.
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Affiliation(s)
- Irene Castellano-Pellicena
- The Charles Institute of Dermatology, School of Medicine, University College Dublin, D04 V1W8 Dublin, Ireland;
| | - Ciaran G. Morrison
- Centre for Chromosome Biology, School of Natural Sciences, National University of Ireland Galway, H91 W2TY Galway, Ireland;
| | - Mike Bell
- Walgreens Boots Alliance, Nottingham NG90 1BS, UK; (M.B.); (C.O.)
| | - Clare O’Connor
- Walgreens Boots Alliance, Nottingham NG90 1BS, UK; (M.B.); (C.O.)
| | - Desmond J. Tobin
- The Charles Institute of Dermatology, School of Medicine, University College Dublin, D04 V1W8 Dublin, Ireland;
- The Conway Institute of Biomolecular and Biomedical Research, University College Dublin, D04 V1W8 Dublin, Ireland
- Correspondence: ; Tel.: +353-(0)-1-716-6262
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17
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Tobin DJ. Unpicking the Gordian knot of identifying metastasis development-relevant proteins in cutaneous squamous cell carcinoma. Br J Dermatol 2020; 184:593. [PMID: 33325538 DOI: 10.1111/bjd.19697] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Accepted: 11/09/2020] [Indexed: 12/01/2022]
Affiliation(s)
- D J Tobin
- Charles Institute of Dermatology, and Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Ireland
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18
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Fagan N, Meah N, York K, Bokhari L, Fletcher G, Chen G, Tobin DJ, Messenger A, Irvine AD, Sinclair R, Wall D. Shedding light on therapeutics in alopecia and their relevance to COVID-19. Clin Dermatol 2020; 39:76-83. [PMID: 33972056 PMCID: PMC7738938 DOI: 10.1016/j.clindermatol.2020.12.015] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
As of July 9, 2020, there were more than 12 million confirmed cases of coronavirus disease 2019 (COVID-19) across the globe, with more than 550,000 deaths. Many European countries, including Belgium, the United Kingdom, Italy, and Spain, have had the highest numbers of fatalities per capita. This indicates the potential for the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus to overwhelm even the most advanced health care systems despite extreme societal interventions. Since its emergence, SARS-CoV-2 has disseminated across the globe, affecting the structure of global societies, infrastructure, and economies. Patients with alopecia are a diverse group who, for various indications, are prescribed a number of antimicrobials and antiandrogen treatments in addition to immunomodulatory therapies such as hydroxychloroquine, oral corticosteroids, and a range of broad immunosuppressants. These drugs are being scrutinized for their capacity to potentially affect SARS-CoV-2 outcomes. We examine these treatments and highlight the critical role that patient registries will play in generating real-world evidence to assess their impact on COVID-19 outcomes.
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Affiliation(s)
- Nicole Fagan
- School of Medicine, Trinity College Dublin, Dublin, Ireland.
| | - Nekma Meah
- Sinclair Dermatology, Melbourne, Australia
| | - Katherine York
- Department of Dermatology, Netcare Greenacres Hospital, Port Elizabeth, South Africa
| | | | - Godfrey Fletcher
- National and International Skin Registry Solutions (NISR), Charles Institute of Dermatology, University College Dublin, Dublin, Ireland
| | - Gang Chen
- Centre for Health Economics, Monash University, Melbourne, Australia
| | - Desmond J Tobin
- The Charles Institute of Dermatology, University College Dublin, Dublin, Ireland
| | - Andrew Messenger
- Department of Dermatology, Royal Hallamshire Hospital, Sheffield, United Kingdom
| | - Alan D Irvine
- Department of Dermatology, Clinical Medicine, Trinity College Dublin, Dublin, Ireland
| | | | - Dmitri Wall
- National and International Skin Registry Solutions (NISR), Charles Institute of Dermatology, University College Dublin, Dublin, Ireland; Hair Restoration Blackrock, Dublin, Ireland
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19
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Sikkink SK, Mine S, Freis O, Danoux L, Tobin DJ. Stress-sensing in the human greying hair follicle: Ataxia Telangiectasia Mutated (ATM) depletion in hair bulb melanocytes in canities-prone scalp. Sci Rep 2020; 10:18711. [PMID: 33128003 PMCID: PMC7603349 DOI: 10.1038/s41598-020-75334-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2020] [Accepted: 10/12/2020] [Indexed: 02/06/2023] Open
Abstract
Canities (or hair greying) is an age-linked loss of the natural pigment called melanin from hair. While the specific cause(s) underlying the loss of melanogenically-active melanocytes from the anagen hair bulbs of affected human scalp remains unclear, oxidative stress sensing appears to be a key factor involved. In this study, we examined the follicular melanin unit in variably pigmented follicles from the aging human scalp of healthy individuals (22-70 years). Over 20 markers were selected within the following categories: melanocyte-specific, apoptosis, cell cycle, DNA repair/damage, senescence and oxidative stress. As expected, a reduction in melanocyte-specific markers in proportion to the extent of canities was observed. A major finding of our study was the intense and highly specific nuclear expression of Ataxia Telangiectasia Mutated (ATM) protein within melanocytes in anagen hair follicle bulbs. ATM is a serine/threonine protein kinase that is recruited and activated by DNA double-strand breaks and functions as an important sensor of reactive oxygen species (ROS) in human cells. The incidence and expression level of ATM correlated with pigmentary status in canities-affected hair follicles. Moreover, increased staining of the redox-associated markers 8-OHdG, GADD45 and GP-1 were also detected within isolated bulbar melanocytes, although this change was not clearly associated with donor age or canities extent. Surprisingly, we were unable to detect any specific change in the expression of other markers of oxidative stress, senescence or DNA damage/repair in the canities-affected melanocytes compared to surrounding bulbar keratinocytes. By contrast, several markers showed distinct expression of markers for oxidative stress and apoptosis/differentiation in the inner root sheath (IRS) as well as other parts of the hair follicle. Using our in vitro model of primary human scalp hair follicle melanocytes, we showed that ATM expression increased after incubation with the pro-oxidant hydrogen peroxide (H2O2). In addition, this ATM increase was prevented by pre-incubation of cells with antioxidants. The relationship between ATM and redox stress sensing was further evidenced as we observed that the inhibition of ATM expression by chemical inhibition promoted the loss of melanocyte viability induced by oxidative stress. Taken together these new findings illustrate the key role of ATM in the protection of human hair follicle melanocytes from oxidative stress/damage within the human scalp hair bulb. In conclusion, these results highlight the remarkable complexity and role of redox sensing in the status of human hair follicle growth, differentiation and pigmentation.
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Affiliation(s)
- Stephen K Sikkink
- Centre for Skin Sciences, School of Life Sciences, University of Bradford, Richmond Rd., Bradford, BD7 1DP, West Yorkshire, UK.
| | - Solene Mine
- BASF Beauty Care Solutions France S.A.S., Pulnoy, France
| | - Olga Freis
- BASF Beauty Care Solutions France S.A.S., Pulnoy, France
| | - Louis Danoux
- BASF Beauty Care Solutions France S.A.S., Pulnoy, France
| | - Desmond J Tobin
- Centre for Skin Sciences, School of Life Sciences, University of Bradford, Richmond Rd., Bradford, BD7 1DP, West Yorkshire, UK. .,The Charles Institute of Dermatology, School of Medicine, University College Dublin, Dublin 4, Ireland.
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20
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O'Sullivan JDB, Nicu C, Picard M, Chéret J, Bedogni B, Tobin DJ, Paus R. The biology of human hair greying. Biol Rev Camb Philos Soc 2020; 96:107-128. [PMID: 32965076 DOI: 10.1111/brv.12648] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Revised: 08/17/2020] [Accepted: 08/20/2020] [Indexed: 12/12/2022]
Abstract
Hair greying (canities) is one of the earliest, most visible ageing-associated phenomena, whose modulation by genetic, psychoemotional, oxidative, senescence-associated, metabolic and nutritional factors has long attracted skin biologists, dermatologists, and industry. Greying is of profound psychological and commercial relevance in increasingly ageing populations. In addition, the onset and perpetuation of defective melanin production in the human anagen hair follicle pigmentary unit (HFPU) provides a superb model for interrogating the molecular mechanisms of ageing in a complex human mini-organ, and greying-associated defects in bulge melanocyte stem cells (MSCs) represent an intriguing system of neural crest-derived stem cell senescence. Here, we emphasize that human greying invariably begins with the gradual decline in melanogenesis, including reduced tyrosinase activity, defective melanosome transfer and apoptosis of HFPU melanocytes, and is thus a primary event of the anagen hair bulb, not the bulge. Eventually, the bulge MSC pool becomes depleted as well, at which stage greying becomes largely irreversible. There is still no universally accepted model of human hair greying, and the extent of genetic contributions to greying remains unclear. However, oxidative damage likely is a crucial driver of greying via its disruption of HFPU melanocyte survival, MSC maintenance, and of the enzymatic apparatus of melanogenesis itself. While neuroendocrine factors [e.g. alpha melanocyte-stimulating hormone (α-MSH), adrenocorticotropic hormone (ACTH), ß-endorphin, corticotropin-releasing hormone (CRH), thyrotropin-releasing hormone (TRH)], and micropthalmia-associated transcription factor (MITF) are well-known regulators of human hair follicle melanocytes and melanogenesis, how exactly these and other factors [e.g. thyroid hormones, hepatocyte growth factor (HGF), P-cadherin, peripheral clock activity] modulate greying requires more detailed study. Other important open questions include how HFPU melanocytes age intrinsically, how psychoemotional stress impacts this process, and how current insights into the gerontobiology of the human HFPU can best be translated into retardation or reversal of greying.
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Affiliation(s)
- James D B O'Sullivan
- Dr. Philip Frost Department for Dermatology and Cutaneous Surgery, University of Miami, Miami, Florida, 33136, U.S.A
| | - Carina Nicu
- Dr. Philip Frost Department for Dermatology and Cutaneous Surgery, University of Miami, Miami, Florida, 33136, U.S.A
| | - Martin Picard
- Departments of Psychiatry and Neurology, Columbia University Irving Medical Center, 622 W 168th Street, PH1540N, New York, 10032, U.S.A
| | - Jérémy Chéret
- Dr. Philip Frost Department for Dermatology and Cutaneous Surgery, University of Miami, Miami, Florida, 33136, U.S.A
| | - Barbara Bedogni
- Dr. Philip Frost Department for Dermatology and Cutaneous Surgery, University of Miami, Miami, Florida, 33136, U.S.A
| | - Desmond J Tobin
- Charles Institute of Dermatology, University College Dublin, Dublin 4, Ireland
| | - Ralf Paus
- Dr. Philip Frost Department for Dermatology and Cutaneous Surgery, University of Miami, Miami, Florida, 33136, U.S.A.,Monasterium Laboratory, Skin & Hair Research Solutions GmbH, Münster, D-48149, Germany.,Centre for Dermatology Research, NIHR Manchester Biomedical Research Centre, University of Manchester, Manchester, M13 9PT, U.K
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21
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Murat K, Grüning B, Poterlowicz PW, Westgate G, Tobin DJ, Poterlowicz K. Ewastools: Infinium Human Methylation BeadChip pipeline for population epigenetics integrated into Galaxy. Gigascience 2020; 9:5836679. [PMID: 32401319 PMCID: PMC7219210 DOI: 10.1093/gigascience/giaa049] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2019] [Revised: 02/24/2020] [Accepted: 04/21/2020] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Infinium Human Methylation BeadChip is an array platform for complex evaluation of DNA methylation at an individual CpG locus in the human genome based on Illumina's bead technology and is one of the most common techniques used in epigenome-wide association studies. Finding associations between epigenetic variation and phenotype is a significant challenge in biomedical research. The newest version, HumanMethylationEPIC, quantifies the DNA methylation level of 850,000 CpG sites, while the previous versions, HumanMethylation450 and HumanMethylation27, measured >450,000 and 27,000 loci, respectively. Although a number of bioinformatics tools have been developed to analyse this assay, they require some programming skills and experience in order to be usable. RESULTS We have developed a pipeline for the Galaxy platform for those without experience aimed at DNA methylation analysis using the Infinium Human Methylation BeadChip. Our tool is integrated into Galaxy (http://galaxyproject.org), a web-based platform. This allows users to analyse data from the Infinium Human Methylation BeadChip in the easiest possible way. CONCLUSIONS The pipeline provides a group of integrated analytical methods wrapped into an easy-to-use interface. Our tool is available from the Galaxy ToolShed, GitHub repository, and also as a Docker image. The aim of this project is to make Infinium Human Methylation BeadChip analysis more flexible and accessible to everyone.
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Affiliation(s)
- Katarzyna Murat
- Center for Skin Sciences, University of Bradford, Richmond Road, Bradford BD7 1DP, UK
| | - Björn Grüning
- Freiburg Galaxy Team, University of Freiburg, Fahnenbergplatz, 79085 Freiburg im Breisgau, Germany
| | | | - Gillian Westgate
- Center for Skin Sciences, University of Bradford, Richmond Road, Bradford BD7 1DP, UK
| | - Desmond J Tobin
- The Charles Institute for Dermatology, Belfield, School of Medicine, University College Dublin, Ireland
| | - Krzysztof Poterlowicz
- Center for Skin Sciences, University of Bradford, Richmond Road, Bradford BD7 1DP, UK
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22
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Slominski AT, Kim TK, Kleszczyński K, Semak I, Janjetovic Z, Sweatman T, Skobowiat C, Steketee JD, Lin Z, Postlethwaite A, Li W, Reiter RJ, Tobin DJ. Characterization of serotonin and N-acetylserotonin systems in the human epidermis and skin cells. J Pineal Res 2020; 68:e12626. [PMID: 31770455 PMCID: PMC7007327 DOI: 10.1111/jpi.12626] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/29/2019] [Revised: 11/15/2019] [Accepted: 11/16/2019] [Indexed: 12/14/2022]
Abstract
Tryptophan hydroxylase (TPH) activity was detected in cultured epidermal melanocytes and dermal fibroblasts with respective Km of 5.08 and 2.83 mM and Vmax of 80.5 and 108.0 µmol/min. Low but detectable TPH activity was also seen in cultured epidermal keratinocytes. Serotonin and/or its metabolite and precursor to melatonin, N-acetylserotonin (NAS), were identified by LC/MS in human epidermis and serum. Endogenous epidermal levels were 113.18 ± 13.34 and 43.41 ± 12.45 ng/mg protein for serotonin (n = 8/8) and NAS (n = 10/13), respectively. Their production was independent of race, gender, and age. NAS was also detected in human serum (n = 13/13) at a concentration 2.44 ± 0.45 ng/mL, while corresponding serotonin levels were 295.33 ± 17.17 ng/mL (n = 13/13). While there were no differences in serum serotonin levels, serum NAS levels were slightly higher in females. Immunocytochemistry studies showed localization of serotonin to epidermal and follicular keratinocytes, eccrine glands, mast cells, and dermal fibrocytes. Endogenous production of serotonin in cultured melanocytes, keratinocytes, and dermal fibroblasts was modulated by UVB. In conclusion, serotonin and NAS are produced endogenously in the epidermal, dermal, and adnexal compartments of human skin and in cultured skin cells. NAS is also detectable in human serum. Both serotonin and NAS inhibited melanogenesis in human melanotic melanoma at concentrations of 10-4 -10-3 M. They also inhibited growth of melanocytes. Melanoma cells were resistant to NAS inhibition, while serotonin inhibited cell growth only at 10-3 M. In summary, we characterized a serotonin-NAS system in human skin that is a part of local neuroendocrine system regulating skin homeostasis.
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Affiliation(s)
- Andrzej T. Slominski
- Department of Dermatology, University of Alabama at Birmingham, and Birmingham, AL, USA
- Department of Dermatology,VA Medical Center; Birmingham, AL, USA
| | - Tae-Kang Kim
- Department of Dermatology, University of Alabama at Birmingham, and Birmingham, AL, USA
| | - Konrad Kleszczyński
- Department of Dermatology, University of Münster, Von-Esmarch-Str. 58, 48149 Münster, Germany
| | - Igor Semak
- Department of Biochemistry, Belarusian State University, Minsk, Belarus
| | - Zorica Janjetovic
- Department of Dermatology, University of Alabama at Birmingham, and Birmingham, AL, USA
| | | | - Cezary Skobowiat
- Department of Pharmacodynamics and Molecular Pharmacology, Faculty of Pharmacy, Collegium Medicum, Nicolaus Copernicus University, Bydgoszcz, Poland
| | | | - Zongtao Lin
- Departments of Pharmaceutical Sciences, Memphis, TN 38163, USA
| | - Arnold Postlethwaite
- Departments of Medicine, Division of Rheumatology, University of Tennessee Health Science Center, Memphis, TN 38163, USA
- Departments of VA Medical Center, Memphis, TN 38163, USA
| | - Wei Li
- Departments of Pharmaceutical Sciences, Memphis, TN 38163, USA
| | - Russel J. Reiter
- Department of Cellular and Structural Biology, UT Health Science Center, San Antonio, TX, USA
| | - Desmond J. Tobin
- The Charles Institute of Dermatology, University College Dublin, Dublin, Ireland
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23
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Adhikari K, Mendoza-Revilla J, Sohail A, Fuentes-Guajardo M, Lampert J, Chacón-Duque JC, Hurtado M, Villegas V, Granja V, Acuña-Alonzo V, Jaramillo C, Arias W, Lozano RB, Everardo P, Gómez-Valdés J, Villamil-Ramírez H, Silva de Cerqueira CC, Hunemeier T, Ramallo V, Schuler-Faccini L, Salzano FM, Gonzalez-José R, Bortolini MC, Canizales-Quinteros S, Gallo C, Poletti G, Bedoya G, Rothhammer F, Tobin DJ, Fumagalli M, Balding D, Ruiz-Linares A. A GWAS in Latin Americans highlights the convergent evolution of lighter skin pigmentation in Eurasia. Nat Commun 2019; 10:358. [PMID: 30664655 PMCID: PMC6341102 DOI: 10.1038/s41467-018-08147-0] [Citation(s) in RCA: 94] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2017] [Accepted: 12/20/2018] [Indexed: 12/17/2022] Open
Abstract
We report a genome-wide association scan in >6,000 Latin Americans for pigmentation of skin and eyes. We found eighteen signals of association at twelve genomic regions. These include one novel locus for skin pigmentation (in 10q26) and three novel loci for eye pigmentation (in 1q32, 20q13 and 22q12). We demonstrate the presence of multiple independent signals of association in the 11q14 and 15q13 regions (comprising the GRM5/TYR and HERC2/OCA2 genes, respectively) and several epistatic interactions among independently associated alleles. Strongest association with skin pigmentation at 19p13 was observed for an Y182H missense variant (common only in East Asians and Native Americans) in MFSD12, a gene recently associated with skin pigmentation in Africans. We show that the frequency of the derived allele at Y182H is significantly correlated with lower solar radiation intensity in East Asia and infer that MFSD12 was under selection in East Asians, probably after their split from Europeans. Pigmentation variation in humans is influenced by complex genetic architecture in different populations. Here, the authors perform a genome-wide association analysis involving > 6,000 Latin Americans for pigmentation of skin and eyes, and identify known and novel genetic associations.
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Affiliation(s)
- Kaustubh Adhikari
- Department of Genetics, Evolution and Environment, and UCL Genetics Institute, University College London, London, WC1E 6BT, UK
| | - Javier Mendoza-Revilla
- Department of Genetics, Evolution and Environment, and UCL Genetics Institute, University College London, London, WC1E 6BT, UK.,Laboratorios de Investigación y Desarrollo, Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia, Lima, 31, Peru
| | - Anood Sohail
- Department of Genetics, Cambridge University, Cambridge, CB2 3EH, UK
| | - Macarena Fuentes-Guajardo
- Department of Genetics, Evolution and Environment, and UCL Genetics Institute, University College London, London, WC1E 6BT, UK.,Departamento de Tecnología Médica, Facultad de Ciencias de la Salud, Universidad de Tarapacá, Arica, 1000000, Chile
| | - Jodie Lampert
- Department of Genetics and Genome Biology, University of Leicester, Leicester, LE1 7RH, UK
| | - Juan Camilo Chacón-Duque
- Department of Genetics, Evolution and Environment, and UCL Genetics Institute, University College London, London, WC1E 6BT, UK
| | - Malena Hurtado
- Laboratorios de Investigación y Desarrollo, Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia, Lima, 31, Peru
| | - Valeria Villegas
- Laboratorios de Investigación y Desarrollo, Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia, Lima, 31, Peru
| | - Vanessa Granja
- Laboratorios de Investigación y Desarrollo, Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia, Lima, 31, Peru
| | - Victor Acuña-Alonzo
- Department of Genetics, Evolution and Environment, and UCL Genetics Institute, University College London, London, WC1E 6BT, UK.,National Institute of Anthropology and History, Mexico City, 4510, Mexico
| | - Claudia Jaramillo
- GENMOL (Genética Molecular), Universidad de Antioquia, Medellín, 5001000, Colombia
| | - William Arias
- GENMOL (Genética Molecular), Universidad de Antioquia, Medellín, 5001000, Colombia
| | - Rodrigo Barquera Lozano
- National Institute of Anthropology and History, Mexico City, 4510, Mexico.,Department of Archaeogenetics, Max Planck Institute for the Science of Human History, Jena, 07745, Germany
| | - Paola Everardo
- National Institute of Anthropology and History, Mexico City, 4510, Mexico
| | - Jorge Gómez-Valdés
- National Institute of Anthropology and History, Mexico City, 4510, Mexico
| | - Hugo Villamil-Ramírez
- Unidad de Genomica de Poblaciones Aplicada a la Salud, Facultad de Química, UNAM-Instituto Nacional de Medicina Genómica, Mexico City, 4510, Mexico
| | - Caio C Silva de Cerqueira
- Departamento de Genética, Universidade Federal do Rio Grande do Sul, Porto Alegre, 91501-970, Brazil
| | - Tábita Hunemeier
- Departamento de Genética, Universidade Federal do Rio Grande do Sul, Porto Alegre, 91501-970, Brazil
| | - Virginia Ramallo
- Departamento de Genética, Universidade Federal do Rio Grande do Sul, Porto Alegre, 91501-970, Brazil.,Instituto Patagonico de Ciencias Sociales y Humanas, Centro Nacional Patagonico, CONICET, Puerto Madryn, U9129ACD, Argentina
| | - Lavinia Schuler-Faccini
- Departamento de Genética, Universidade Federal do Rio Grande do Sul, Porto Alegre, 91501-970, Brazil
| | - Francisco M Salzano
- Departamento de Genética, Universidade Federal do Rio Grande do Sul, Porto Alegre, 91501-970, Brazil
| | - Rolando Gonzalez-José
- Instituto Patagonico de Ciencias Sociales y Humanas, Centro Nacional Patagonico, CONICET, Puerto Madryn, U9129ACD, Argentina
| | - Maria-Cátira Bortolini
- Departamento de Genética, Universidade Federal do Rio Grande do Sul, Porto Alegre, 91501-970, Brazil
| | - Samuel Canizales-Quinteros
- Unidad de Genomica de Poblaciones Aplicada a la Salud, Facultad de Química, UNAM-Instituto Nacional de Medicina Genómica, Mexico City, 4510, Mexico
| | - Carla Gallo
- Laboratorios de Investigación y Desarrollo, Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia, Lima, 31, Peru
| | - Giovanni Poletti
- Laboratorios de Investigación y Desarrollo, Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia, Lima, 31, Peru
| | - Gabriel Bedoya
- GENMOL (Genética Molecular), Universidad de Antioquia, Medellín, 5001000, Colombia
| | - Francisco Rothhammer
- Instituto de Alta Investigación, Universidad de Tarapaca, Arica, 1000000, Chile.,Programa de Genetica Humana, ICBM, Facultad de Medicina, Universidad de Chile, Santiago, 8320000, Chile
| | - Desmond J Tobin
- Centre for Skin Sciences, Faculty of Life Sciences, University of Bradford, Bradford, BD7 1DP, West Yorkshire, UK.,The Charles Institute of Dermatology, University College Dublin, Dublin, D4, Ireland
| | - Matteo Fumagalli
- Department of Life Sciences, Silwood Park campus, Imperial College London, Ascot, SL5 7PY, UK
| | - David Balding
- Department of Genetics, Evolution and Environment, and UCL Genetics Institute, University College London, London, WC1E 6BT, UK.,Melbourne Integrative Genomics, Schools of BioSciences and Mathematics & Statistics, University of Melbourne, Melbourne, VIC, 3010, Australia
| | - Andrés Ruiz-Linares
- Ministry of Education Key Laboratory of Contemporary Anthropology and Collaborative Innovation Center of Genetics and Development, School of Life Sciences and Human Phenome Institute, Fudan University, Shanghai, 200438, China. .,Aix-Marseille Université, CNRS, EFS, ADES, Marseille, 13005, France.
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24
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Tobin DJ. Early evidence for opposing effects of full versus fragmented adiponectin on melanogenesis in human epidermal melanocytes. Br J Dermatol 2018; 179:561-562. [PMID: 30222881 DOI: 10.1111/bjd.16909] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Affiliation(s)
- D J Tobin
- The Charles Institute for Dermatology, School of Medicine, University College Dublin, Ireland
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25
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Joly-Tonetti N, Wibawa JID, Bell M, Tobin DJ. An explanation for the mysterious distribution of melanin in human skin: a rare example of asymmetric (melanin) organelle distribution during mitosis of basal layer progenitor keratinocytes. Br J Dermatol 2018; 179:1115-1126. [PMID: 29956303 DOI: 10.1111/bjd.16926] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/28/2018] [Indexed: 12/30/2022]
Abstract
BACKGROUND Melanin is synthesized by melanocytes in the basal layer of the epidermis. When transferred to surrounding keratinocytes melanin is the key ultraviolet radiation-protective biopolymer responsible for skin pigmentation. Most melanin is observable in the proliferative basal layer of the epidermis and only sparsely distributed in the stratifying/differentiating epidermis. The latter has been explained as 'melanin degradation' in suprabasal layers. OBJECTIVES To re-evaluate the currently accepted basis for melanin distribution in human epidermis and to discover whether this pattern is altered after a regenerative stimulus. METHODS Normal epidermis of adult human skin, at rest and after tape-stripping, was analysed by a range of (immuno)histochemical and high-resolution microscopy techniques. In vitro models of melanin granule uptake by human keratinocytes were attempted. RESULTS We propose a different fate for melanin in the human epidermis. Our evidence indicates that the bulk of melanin is inherited only by the nondifferentiating daughter cell postmitosis in progenitor keratinocytes via asymmetric organelle inheritance. Moreover, this preferred pattern of melanin distribution can switch to a symmetric or equal daughter cell inheritance mode under conditions of stress, including regeneration. CONCLUSIONS In this preliminary report, we provide a plausible and histologically supported explanation for how human skin pigmentation is efficiently organized in the epidermis. Steady-state epidermis pigmentation may involve much less redox-sensitive melanogenesis than previously thought, and at least some premade melanin may be available for reuse. The epidermal melanin unit may be an excellent example with which to study organelle distribution via asymmetric or symmetric inheritance in response to microenvironment and tissue demands.
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Affiliation(s)
- N Joly-Tonetti
- Centre for Skin Sciences, Faculty of Life Sciences, University of Bradford, Bradford, U.K
| | | | - M Bell
- Walgreens Boots Alliance, Nottingham, U.K
| | - D J Tobin
- Centre for Skin Sciences, Faculty of Life Sciences, University of Bradford, Bradford, U.K
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26
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Mignon C, Uzunbajakava NE, Castellano-Pellicena I, Botchkareva NV, Tobin DJ. Differential response of human dermal fibroblast subpopulations to visible and near-infrared light: Potential of photobiomodulation for addressing cutaneous conditions. Lasers Surg Med 2018; 50:859-882. [PMID: 29665018 DOI: 10.1002/lsm.22823] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/14/2018] [Indexed: 12/12/2022]
Abstract
BACKGROUND OBJECTIVES The past decade has witnessed a rapid expansion of photobiomodulation (PBM), demonstrating encouraging results for the treatment of cutaneous disorders. Confidence in this approach, however, is impaired not only by a lack of understanding of the light-triggered molecular cascades but also by the significant inconsistency in published experimental outcomes, design of the studies and applied optical parameters. This study aimed at characterizing the response of human dermal fibroblast subpopulations to visible and near-infrared (NIR) light in an attempt to identify the optical treatment parameters with high potential to address deficits in aging skin and non-healing chronic wounds. MATERIALS AND METHODS Primary human reticular and papillary dermal fibroblasts (DF) were isolated from the surplus of post-surgery human facial skin. An in-house developed LED-based device was used to irradiate cell cultures using six discrete wavelengths (450, 490, 550, 590, 650, and 850 nm). Light dose-response at a standard oxygen concentration (20%) at all six wavelengths was evaluated in terms of cell metabolic activity. This was followed by an analysis of the transcriptome and procollagen I production at a protein level, where cells were cultured in conditions closer to in vivo at 2% environmental oxygen and 2% serum. Furthermore, the production of reactive oxygen species (ROS) was accessed using real-time fluorescence confocal microscopy imaging. Here, production of ROS in the presence or absence of antioxidants, as well as the cellular localization of ROS, was evaluated. RESULTS In terms of metabolic activity, consecutive irradiation with short-wavelength light (⇐530 nm) exerted an inhibitory effect on DF, while longer wavelengths (>=590 nm) had essentially a neutral effect. Cell behavior following treatment with 450 nm was biphasic with two distinct states: inhibitory at low- to mid- dose levels (<=30 J/cm2 ), and cytotoxic at higher dose levels (>30 J/cm2 ). Cell response to blue light was accompanied by a dose-dependent release of ROS that was localized in the perinuclear area close to mitochondria, which was attenuated by an antioxidant. Overall, reticular DFs exhibited a greater sensitivity to light treatment at the level of gene expression than did papillary DFs, with more genes significantly up- or down- regulated. At the intra-cellular signaling pathway level, the up- or down- regulation of vital pathways was observed only for reticular DF, after treatment with 30 J/cm2 of blue light. At the cellular level, short visible wavelengths exerted a greater inhibitory effect on reticular DF. Several genes involved in the TGF-β signaling pathway were also affected. In addition, procollagen I production was inhibited. By contrast, 850 nm near-infrared (NIR) light (20 J/cm2 ) exerted a stimulatory metabolic effect in these cells, with no detectable intracellular ROS formation. Here too, reticular DF were more responsive than papillary DF. This stimulatory effect was only observed under in vivo-like low oxygen conditions, corresponding to normal dermal tissue oxygen levels (approximately 2%). CONCLUSION This study highlights a differential impact of light on human skin cells with upregulation of metabolic activity with NIR light, and inhibition of pro-collagen production and proliferation in response to blue light. These findings open-up new avenues for developing therapies for different cutaneous conditions (e.g., treatment of keloids and fibrosis) or differential therapy at distinct stages of wound healing. Lasers Surg. Med. 50:859-882, 2018. © 2018 Wiley Periodicals, Inc.
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Affiliation(s)
- Charles Mignon
- Centre for Skin Sciences, University of Bradford, BD71DP, Bradford, United-Kingdom.,Philips Research, High Tech Campus, Eindhoven, Netherlands
| | | | - Irene Castellano-Pellicena
- Centre for Skin Sciences, University of Bradford, BD71DP, Bradford, United-Kingdom.,Philips Research, High Tech Campus, Eindhoven, Netherlands
| | | | - Desmond J Tobin
- Centre for Skin Sciences, University of Bradford, BD71DP, Bradford, United-Kingdom
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27
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Fajuyigbe D, Lwin SM, Diffey BL, Baker R, Tobin DJ, Sarkany RPE, Young AR. Melanin distribution in human epidermis affords localized protection against DNA photodamage and concurs with skin cancer incidence difference in extreme phototypes. FASEB J 2018; 32:3700-3706. [PMID: 29394104 DOI: 10.1096/fj.201701472r] [Citation(s) in RCA: 59] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Epidermal DNA damage, especially to the basal layer, is an established cause of keratinocyte cancers (KCs). Large differences in KC incidence (20- to 60-fold) between white and black populations are largely attributable to epidermal melanin photoprotection in the latter. The cyclobutane pyrimidine dimer (CPD) is the most mutagenic DNA photolesion; however, most studies suggest that melanin photoprotection against CPD is modest and cannot explain the considerable skin color-based differences in KC incidence. Along with melanin quantity, solar-simulated radiation-induced CPD assessed immediately postexposure in the overall epidermis and within 3 epidermal zones was compared in black West Africans and fair Europeans. Melanin in black skin protected against CPD by 8.0-fold in the overall epidermis and by 59.0-, 16.5-, and 5.0-fold in the basal, middle, and upper epidermis, respectively. Protection was related to the distribution of melanin, which was most concentrated in the basal layer of black skin. These results may explain, at least in part, the considerable skin color differences in KC incidence. These data suggest that a DNA protection factor of at least 60 is necessary in sunscreens to reduce white skin KC incidence to a level that is comparable with that of black skin.-Fajuyigbe, D., Lwin, S. M., Diffey, B. L., Baker, R., Tobin, D. J., Sarkany, R. P. E., Young, A. R. Melanin distribution in human epidermis affords localized protection against DNA photodamage and concurs with skin cancer incidence difference in extreme phototypes.
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Affiliation(s)
- Damilola Fajuyigbe
- St. John's Institute of Dermatology, King's College London, London, United Kingdom
| | - Su M Lwin
- St. John's Institute of Dermatology, King's College London, London, United Kingdom
| | - Brian L Diffey
- Dermatological Sciences, Institute of Cellular Medicine, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Richard Baker
- Centre for Skin Sciences, Faculty of Life Sciences, University of Bradford, Bradford, United Kingdom
| | - Desmond J Tobin
- Centre for Skin Sciences, Faculty of Life Sciences, University of Bradford, Bradford, United Kingdom
| | - Robert P E Sarkany
- St. John's Institute of Dermatology, King's College London, London, United Kingdom
| | - Antony R Young
- St. John's Institute of Dermatology, King's College London, London, United Kingdom
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28
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Miranda BH, Charlesworth MR, Tobin DJ, Sharpe DT, Randall VA. Androgens trigger different growth responses in genetically identical human hair follicles in organ culture that reflect their epigenetic diversity in life. FASEB J 2018; 32:795-806. [PMID: 29046359 PMCID: PMC5928870 DOI: 10.1096/fj.201700260rr] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Male sex hormones-androgens-regulate male physique development. Without androgen signaling, genetic males appear female. During puberty, increasing androgens harness the hair follicle's unique regenerative ability to replace many tiny vellus hairs with larger, darker terminal hairs ( e.g., beard). Follicle response is epigenetically varied: some remain unaffected ( e.g., eyelashes) or are inhibited, causing balding. How sex steroid hormones alter such developmental processes is unclear, despite high incidences of hormone-driven cancer, hirsutism, and alopecia. Unfortunately, existing development models are not androgen sensitive. Here, we use hair follicles to establish an androgen-responsive human organ culture model. We show that women's intermediate facial follicles respond to men's higher androgen levels by synthesizing more hair over several days, unlike donor-matched, androgen-insensitive, terminal follicles. We demonstrate that androgen receptors-androgen-activated gene transcription regulators-are required and are present in vivo within these follicles. This is the first human organ that involves multiple cell types that responds appropriately to hormones in prolonged culture, in a way which mirrors its natural behavior. Thus, intermediate hair follicles offer a hormone-switchable human model with exceptional, unique availability of genetically identical, but epigenetically hormone-insensitive, terminal follicles. This should enable advances in understanding sex steroid hormone signaling, gene regulation, and developmental and regenerative systems and facilitate better therapies for hormone-dependent disorders.-Miranda, B. H., Charlesworth, M. R., Tobin, D. J., Sharpe, D. T., Randall, V. A. Androgens trigger different growth responses in genetically identical human hair follicles in organ culture that reflect their epigenetic diversity in life.
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Affiliation(s)
- Benjamin H Miranda
- Centre for Skin Sciences, University of Bradford, Bradford, United Kingdom.,Plastic Surgery and Burns Research Unit, University of Bradford, Bradford, United Kingdom
| | | | - Desmond J Tobin
- Centre for Skin Sciences, University of Bradford, Bradford, United Kingdom
| | - David T Sharpe
- Centre for Skin Sciences, University of Bradford, Bradford, United Kingdom.,Plastic Surgery and Burns Research Unit, University of Bradford, Bradford, United Kingdom
| | - Valerie A Randall
- Centre for Skin Sciences, University of Bradford, Bradford, United Kingdom
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29
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Weiland D, Brachvogel B, Hornig-Do HT, Neuhaus JF, Holzer T, Tobin DJ, Niessen CM, Wiesner RJ, Baris OR. Imbalance of Mitochondrial Respiratory Chain Complexes in the Epidermis Induces Severe Skin Inflammation. J Invest Dermatol 2018; 138:132-140. [DOI: 10.1016/j.jid.2017.08.019] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2017] [Revised: 08/16/2017] [Accepted: 08/16/2017] [Indexed: 11/24/2022]
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30
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Singh SK, Baker R, Sikkink SK, Nizard C, Schnebert S, Kurfurst R, Tobin DJ. E-cadherin mediates ultraviolet radiation- and calcium-induced melanin transfer in human skin cells. Exp Dermatol 2017. [PMID: 28636748 DOI: 10.1111/exd.13395] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Skin pigmentation is directed by epidermal melanin units, characterized by long-lived and dendritic epidermal melanocytes (MC) that interact with viable keratinocytes (KC) to contribute melanin to the epidermis. Previously, we reported that MC:KC contact is required for melanosome transfer that can be enhanced by filopodi, and by UVR/UVA irradiation, which can upregulate melanosome transfer via Myosin X-mediated control of MC filopodia. Both MC and KC express Ca2+ -dependent E-cadherins. These homophilic adhesion contacts induce transient increases in intra-KC Ca2+ , while ultraviolet radiation (UVR) raises intra-MC Ca2+ via calcium-selective ORAI1 ion channels; both are associated with regulating melanogenesis. However, how Ca2+ triggers melanin transfer remains unclear. Here we evaluated the role of E-cadherin in UVR-mediated melanin transfer in human skin cells. MC and KC in human epidermis variably express filopodia-associated E-cadherin, Cdc42, VASP and β-catenin, all of which were upregulated by UVR in human MC in vitro. Knockdown of E-cadherin revealed that this cadherin is essential for UVR-induced MC filopodia formation and melanin transfer. Moreover, Ca2+ induced a dose-dependent increase in filopodia formation and melanin transfer, as well as increased β-catenin, Cdc42, Myosin X and E-cadherin expression in these skin cells. Together, these data suggest that filopodial proteins and E-cadherin, which are upregulated by intracellular (UVR-stimulated) and extracellular Ca2+ availability, are required for filopodia formation and melanin transfer. This may open new avenues to explore how Ca2+ signalling influences human pigmentation.
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Affiliation(s)
- Suman K Singh
- Centre for Skin Sciences, Faculty of Life Sciences, University of Bradford, Bradford, UK
| | - Richard Baker
- Centre for Skin Sciences, Faculty of Life Sciences, University of Bradford, Bradford, UK
| | - Stephen K Sikkink
- Centre for Skin Sciences, Faculty of Life Sciences, University of Bradford, Bradford, UK
| | | | | | | | - Desmond J Tobin
- Centre for Skin Sciences, Faculty of Life Sciences, University of Bradford, Bradford, UK
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31
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Sonthalia S, Priya A, Tobin DJ. Demographic Characteristics and Association of Serum Vitamin B12, Ferritin and Thyroid Function with Premature Canities in Indian Patients from an Urban Skin Clinic of North India: A Retrospective Analysis of 71 Cases. Indian J Dermatol 2017; 62:304-308. [PMID: 28584374 PMCID: PMC5448266 DOI: 10.4103/ijd.ijd_221_17] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Background: The incidence of self-reported premature hair graying (PHG) seems to be on the rise. PHG has a profound impact on the patient's quality of life. It remains an incompletely understood etiology with limited and modest treatment options. Aim: The evaluation of the demographic and clinical profile of patients with premature canities, and exploration of the association of this entity with certain systemic disorders suspected to be related to its etiology. Methods: Seventy-one cases of premature canities (onset noticed by patients before 25 years of age) presenting to an urban skin clinic in Gurugram, India, between September 2012 and September 2015 with this complaint were retrospectively analyzed. The patient records were retrieved that provided details of the onset, duration and pattern of involvement, history, and examination findings (scalp, cutis, and general physical). Since all these patients had been screened for anemia, thyroid disorder, fasting blood glucose, and Vitamin B12 levels at the time of presentation, these parameters were also available for analysis. Results: The mean age at onset of graying was 10.2 ± 3.6 years (range: 5–19 years), with an almost equal gender distribution. The earliest age of onset recorded was 5 years. A positive family history of PHG (at least one of the biological parents or siblings) was obtained in 64 (90.1%) of the cases. The temporal regions of the scalp (35.2%) were most commonly involved followed by the frontal region (18.3%). Hypovitaminosis B12 and hypothyroidism showed significant association with the disorder, whereas anemia, serum ferritin, and fasting blood glucose did not. Conclusion: The age of onset of hair graying can be as low as 5 years. Temporal and frontal areas are the most commonly involved sites. A strong family history, Vitamin B12 deficiency, and hypothyroidism are strongly associated with PHG. Larger case–control studies are mandated for discerning the correlation of these and other risk factors with PHG.
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Affiliation(s)
| | - Adity Priya
- Department of Community Medicine, Hind Institute of Medical Sciences, Lucknow, Uttar Pradesh, India
| | - Desmond J Tobin
- Centre for Skin Sciences, Faculty of Life Sciences, University of Bradford, Bradford, West Yorkshire BD7 1DP, UK
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32
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Mignon C, Uzunbajakava NE, Raafs B, Botchkareva NV, Tobin DJ. Photobiomodulation of human dermal fibroblasts in vitro: decisive role of cell culture conditions and treatment protocols on experimental outcome. Sci Rep 2017; 7:2797. [PMID: 28584230 PMCID: PMC5459822 DOI: 10.1038/s41598-017-02802-0] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2016] [Accepted: 04/19/2017] [Indexed: 11/28/2022] Open
Abstract
Photobiomodulation-based (LLLT) therapies show tantalizing promise for treatment of skin diseases. Confidence in this approach is blighted however by lamentable inconsistency in published experimental designs, and so complicates interpretation. Here we interrogate the appropriateness of a range of previously-reported treatment parameters, including light wavelength, irradiance and radiant exposure, as well as cell culture conditions (e.g., serum concentration, cell confluency, medium refreshment, direct/indirect treatment, oxygen concentration, etc.), in primary cultures of normal human dermal fibroblasts exposed to visible and near infra-red (NIR) light. Apart from irradiance, all study parameters impacted significantly on fibroblast metabolic activity. Moreover, when cells were grown at atmospheric O2 levels (i.e. 20%) short wavelength light inhibited cell metabolism, while negligible effects were seen with long visible and NIR wavelength. By contrast, NIR stimulated cells when exposed to dermal tissue oxygen levels (approx. 2%). The impact of culture conditions was further seen when inhibitory effects of short wavelength light were reduced with increasing serum concentration and cell confluency. We conclude that a significant source of problematic interpretations in photobiomodulation reports derives from poor optimization of study design. Further development of this field using in vitro/ex vivo models should embrace significant standardization of study design, ideally within a design-of-experiment setting.
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Affiliation(s)
- C Mignon
- Philips Research, High Tech Campus 11, 5656 AE, Eindhoven, The Netherlands
- Centre for Skin Sciences, Faculty of Life Sciences, University of Bradford, Richmond Road, BD7 1DP, Bradford, West Yorkshire, UK
| | - N E Uzunbajakava
- Philips Research, High Tech Campus 11, 5656 AE, Eindhoven, The Netherlands.
| | - B Raafs
- Philips Research, High Tech Campus 11, 5656 AE, Eindhoven, The Netherlands
| | - N V Botchkareva
- Centre for Skin Sciences, Faculty of Life Sciences, University of Bradford, Richmond Road, BD7 1DP, Bradford, West Yorkshire, UK
| | - D J Tobin
- Centre for Skin Sciences, Faculty of Life Sciences, University of Bradford, Richmond Road, BD7 1DP, Bradford, West Yorkshire, UK
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33
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Mignon C, Botchkareva NV, Uzunbajakava NE, Tobin DJ. Photobiomodulation devices for hair regrowth and wound healing: a therapy full of promise but a literature full of confusion. Exp Dermatol 2016; 25:745-9. [PMID: 27095546 DOI: 10.1111/exd.13035] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/15/2016] [Indexed: 01/09/2023]
Abstract
Photobiomodulation is reported to positively influence hair regrowth, wound healing, skin rejuvenation and psoriasis. Despite rapid translation of this science to commercial therapeutic solutions, significant gaps in our understanding of the underlying processes remain. The aim of this review was to seek greater clarity and rationality specifically for the selection of optical parameters for studies on hair regrowth and wound healing. Our investigation of 90 reports published between 1985 and 2015 revealed major inconsistencies in optical parameters selected for clinical applications. Moreover, poorly understood photoreceptors expressed in skin such as cytochrome c oxidase, cryptochromes, opsins etc. may trigger different molecular mechanisms. All this could explain the plethora of reported physiological effects of light. To derive parameters for optimal clinical efficacy of photobiomodulation, we recommend a more rational approach to underpin clinical studies, with research on molecular targets and pathways using well-defined biological model systems to enable translation of optical parameters from in vitro to in vivo. Furthermore, special attention needs to be paid when conducting studies for hair regrowth, aiming for double-blind, placebo-controlled randomized clinical trials as the gold standard for quantifying hair growth.
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Affiliation(s)
- Charles Mignon
- Centre for Skin Sciences, Faculty of Life Sciences, University of Bradford, Bradford, UK.,Philips Research, Eindhoven, the Netherlands
| | - Natalia V Botchkareva
- Centre for Skin Sciences, Faculty of Life Sciences, University of Bradford, Bradford, UK
| | | | - Desmond J Tobin
- Centre for Skin Sciences, Faculty of Life Sciences, University of Bradford, Bradford, UK
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34
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Adhikari K, Fontanil T, Cal S, Mendoza-Revilla J, Fuentes-Guajardo M, Chacón-Duque JC, Al-Saadi F, Johansson JA, Quinto-Sanchez M, Acuña-Alonzo V, Jaramillo C, Arias W, Barquera Lozano R, Macín Pérez G, Gómez-Valdés J, Villamil-Ramírez H, Hunemeier T, Ramallo V, Silva de Cerqueira CC, Hurtado M, Villegas V, Granja V, Gallo C, Poletti G, Schuler-Faccini L, Salzano FM, Bortolini MC, Canizales-Quinteros S, Rothhammer F, Bedoya G, Gonzalez-José R, Headon D, López-Otín C, Tobin DJ, Balding D, Ruiz-Linares A. A genome-wide association scan in admixed Latin Americans identifies loci influencing facial and scalp hair features. Nat Commun 2016; 7:10815. [PMID: 26926045 PMCID: PMC4773514 DOI: 10.1038/ncomms10815] [Citation(s) in RCA: 118] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2015] [Accepted: 01/25/2016] [Indexed: 12/20/2022] Open
Abstract
We report a genome-wide association scan in over 6,000 Latin Americans for features of scalp hair (shape, colour, greying, balding) and facial hair (beard thickness, monobrow, eyebrow thickness). We found 18 signals of association reaching genome-wide significance (P values 5 × 10(-8) to 3 × 10(-119)), including 10 novel associations. These include novel loci for scalp hair shape and balding, and the first reported loci for hair greying, monobrow, eyebrow and beard thickness. A newly identified locus influencing hair shape includes a Q30R substitution in the Protease Serine S1 family member 53 (PRSS53). We demonstrate that this enzyme is highly expressed in the hair follicle, especially the inner root sheath, and that the Q30R substitution affects enzyme processing and secretion. The genome regions associated with hair features are enriched for signals of selection, consistent with proposals regarding the evolution of human hair.
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Affiliation(s)
- Kaustubh Adhikari
- Department of Genetics, Evolution and Environment, and UCL Genetics Institute, University College London, London WC1E 6BT, UK
| | - Tania Fontanil
- Departamento de Bioquímica y Biología Molecular, IUOPA, Universidad de Oviedo, Oviedo 33006, Spain
| | - Santiago Cal
- Departamento de Bioquímica y Biología Molecular, IUOPA, Universidad de Oviedo, Oviedo 33006, Spain
| | - Javier Mendoza-Revilla
- Department of Genetics, Evolution and Environment, and UCL Genetics Institute, University College London, London WC1E 6BT, UK
- Laboratorios de Investigación y Desarrollo, Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia, Lima, 31, Perú
| | - Macarena Fuentes-Guajardo
- Department of Genetics, Evolution and Environment, and UCL Genetics Institute, University College London, London WC1E 6BT, UK
- Departamento de Tecnología Médica, Facultad de Ciencias de la Salud, Universidad de Tarapacá, Arica 1000009, Chile
| | - Juan-Camilo Chacón-Duque
- Department of Genetics, Evolution and Environment, and UCL Genetics Institute, University College London, London WC1E 6BT, UK
| | - Farah Al-Saadi
- Department of Genetics, Evolution and Environment, and UCL Genetics Institute, University College London, London WC1E 6BT, UK
| | - Jeanette A. Johansson
- Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Midlothian EH25 9RG, UK
| | | | - Victor Acuña-Alonzo
- Department of Genetics, Evolution and Environment, and UCL Genetics Institute, University College London, London WC1E 6BT, UK
- National Institute of Anthropology and History, México 4510, México
| | - Claudia Jaramillo
- GENMOL (Genética Molecular), Universidad de Antioquia, Medellín 5001000, Colombia
| | - William Arias
- GENMOL (Genética Molecular), Universidad de Antioquia, Medellín 5001000, Colombia
| | - Rodrigo Barquera Lozano
- National Institute of Anthropology and History, México 4510, México
- Unidad de Genómica de Poblaciones Aplicada a la Salud, Facultad de Química, UNAM-Instituto Nacional de Medicina Genómica, México 4510, México
| | - Gastón Macín Pérez
- National Institute of Anthropology and History, México 4510, México
- Unidad de Genómica de Poblaciones Aplicada a la Salud, Facultad de Química, UNAM-Instituto Nacional de Medicina Genómica, México 4510, México
| | | | - Hugo Villamil-Ramírez
- Unidad de Genómica de Poblaciones Aplicada a la Salud, Facultad de Química, UNAM-Instituto Nacional de Medicina Genómica, México 4510, México
| | - Tábita Hunemeier
- Departamento de Genética, Universidade Federal do Rio Grande do Sul, Porto Alegre 91501-970, Brasil
| | - Virginia Ramallo
- Centro Nacional Patagónico, CONICET, Puerto Madryn U9129ACD, Argentina
- Departamento de Genética, Universidade Federal do Rio Grande do Sul, Porto Alegre 91501-970, Brasil
| | - Caio C. Silva de Cerqueira
- Centro Nacional Patagónico, CONICET, Puerto Madryn U9129ACD, Argentina
- Departamento de Genética, Universidade Federal do Rio Grande do Sul, Porto Alegre 91501-970, Brasil
| | - Malena Hurtado
- Laboratorios de Investigación y Desarrollo, Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia, Lima, 31, Perú
| | - Valeria Villegas
- Laboratorios de Investigación y Desarrollo, Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia, Lima, 31, Perú
| | - Vanessa Granja
- Laboratorios de Investigación y Desarrollo, Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia, Lima, 31, Perú
| | - Carla Gallo
- Laboratorios de Investigación y Desarrollo, Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia, Lima, 31, Perú
| | - Giovanni Poletti
- Laboratorios de Investigación y Desarrollo, Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia, Lima, 31, Perú
| | - Lavinia Schuler-Faccini
- Departamento de Genética, Universidade Federal do Rio Grande do Sul, Porto Alegre 91501-970, Brasil
| | - Francisco M. Salzano
- Departamento de Genética, Universidade Federal do Rio Grande do Sul, Porto Alegre 91501-970, Brasil
| | - Maria-Cátira Bortolini
- Departamento de Genética, Universidade Federal do Rio Grande do Sul, Porto Alegre 91501-970, Brasil
| | - Samuel Canizales-Quinteros
- Unidad de Genómica de Poblaciones Aplicada a la Salud, Facultad de Química, UNAM-Instituto Nacional de Medicina Genómica, México 4510, México
| | | | - Gabriel Bedoya
- GENMOL (Genética Molecular), Universidad de Antioquia, Medellín 5001000, Colombia
| | | | - Denis Headon
- Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Midlothian EH25 9RG, UK
| | - Carlos López-Otín
- Departamento de Bioquímica y Biología Molecular, IUOPA, Universidad de Oviedo, Oviedo 33006, Spain
| | - Desmond J. Tobin
- Centre for Skin Sciences, Faculty of Life Sciences, University of Bradford, Bradford BD7 1DP, Victoria, UK
| | - David Balding
- Department of Genetics, Evolution and Environment, and UCL Genetics Institute, University College London, London WC1E 6BT, UK
- Schools of BioSciences and Mathematics and Statistics, University of Melbourne, Melbourne 3010, Australia
| | - Andrés Ruiz-Linares
- Department of Genetics, Evolution and Environment, and UCL Genetics Institute, University College London, London WC1E 6BT, UK
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Alase AA, El-Sherbiny YM, Vital EM, Tobin DJ, Turner NA, Wittmann M. IFNλ Stimulates MxA Production in Human Dermal Fibroblasts via a MAPK-Dependent STAT1-Independent Mechanism. J Invest Dermatol 2015; 135:2935-2943. [PMID: 26288353 DOI: 10.1038/jid.2015.317] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2015] [Revised: 06/17/2015] [Accepted: 07/11/2015] [Indexed: 02/07/2023]
Abstract
IFNλ is important for epidermal defense against viruses. It is produced by, and acts on, keratinocytes, whereas fibroblasts were previously considered to be unresponsive to this type III IFN. Herein we report findings revealing cell type-specific differences in IFNλ signaling and function in skin resident cells. In dermal fibroblasts, IFNλ induced the expression of myxovirus protein A (MxA), a potent antiviral factor, but not other IFN signature genes as it does in primary keratinocytes. In contrast to its effect on keratinocytes, IFNλ did not phosphorylate signal transducer and activator of transcription 1 in fibroblasts, but instead activated mitogen activated protein kinases (MAPK). Accordingly, inhibition of MAPK activation (p38 and p42/44) blocked the expression of MxA protein in fibroblasts but not in keratinocytes. Functionally, IFNλ inhibited proliferation in keratinocytes but not in fibroblasts. Moreover, IFNλ upregulated the expression of Tumor growth factor beta 1 (TGFβ1)-induced collagens in fibroblasts. Taken together, our findings identify primary human dermal fibroblasts as responder cells to IFNλ. Our study shows cutaneous cell type-specific IFN signaling and suggests that IFNλ, although important for epidermal antiviral competence, may also have a regulatory role in the dermal compartment balancing type I IFN-induced inhibition of tissue repair processes.
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Affiliation(s)
- Adewonuola A Alase
- Centre for Skin Sciences, Faculty of Life Sciences, University of Bradford, Bradford, UK.
| | - Yasser M El-Sherbiny
- Leeds Institute of Rheumatic and Musculoskeletal Medicine (LIRMM), Faculty of Medicine and Health, University of Leeds, Leeds, UK; Clinical Pathology Department, Faculty of Medicine, Mansoura University, Mansoura, Egypt
| | - Edward M Vital
- Leeds Institute of Rheumatic and Musculoskeletal Medicine (LIRMM), Faculty of Medicine and Health, University of Leeds, Leeds, UK
| | - Desmond J Tobin
- Centre for Skin Sciences, Faculty of Life Sciences, University of Bradford, Bradford, UK
| | - Neil A Turner
- Division of Cardiovascular and Diabetes Research, Leeds Institute for Cardiovascular and Diabetes Research (LICAMM), Faculty of Medicine and Health, University of Leeds, Leeds, UK
| | - Miriam Wittmann
- Centre for Skin Sciences, Faculty of Life Sciences, University of Bradford, Bradford, UK; Leeds Institute of Rheumatic and Musculoskeletal Medicine (LIRMM), Faculty of Medicine and Health, University of Leeds, Leeds, UK; Department of Dermatology, Bradford Teaching Hospitals NHS Foundation Trust, St Luke's Hospital, Bradford, UK; Leeds Musculoskeletal Biomedical Research Unit, National Institute of Health Research (NIHR), Chapel Allerton Hospital, Leeds, UK
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36
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Grant CA, Twigg PC, Baker R, Tobin DJ. Tattoo ink nanoparticles in skin tissue and fibroblasts. Beilstein J Nanotechnol 2015; 6:1183-1191. [PMID: 26171294 PMCID: PMC4464189 DOI: 10.3762/bjnano.6.120] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/21/2014] [Accepted: 04/22/2015] [Indexed: 06/04/2023]
Abstract
Tattooing has long been practised in various societies all around the world and is becoming increasingly common and widespread in the West. Tattoo ink suspensions unquestionably contain pigments composed of nanoparticles, i.e., particles of sub-100 nm dimensions. It is widely acknowledged that nanoparticles have higher levels of chemical activity than their larger particle equivalents. However, assessment of the toxicity of tattoo inks has been the subject of little research and ink manufacturers are not obliged to disclose the exact composition of their products. This study examines tattoo ink particles in two fundamental skin components at the nanometre level. We use atomic force microscopy and light microscopy to examine cryosections of tattooed skin, exploring the collagen fibril networks in the dermis that contain ink nanoparticles. Further, we culture fibroblasts in diluted tattoo ink to explore both the immediate impact of ink pigment on cell viability and also to observe the interaction between particles and the cells.
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Affiliation(s)
- Colin A Grant
- Advanced Materials Engineering, Faculty of Engineering and Informatics, University of Bradford, Bradford, BD7 1DP, United Kingdom
| | - Peter C Twigg
- Advanced Materials Engineering, Faculty of Engineering and Informatics, University of Bradford, Bradford, BD7 1DP, United Kingdom
| | - Richard Baker
- Centre for Skin Sciences, Faculty of Life Sciences, University of Bradford, Bradford, BD7 1DP, United Kingdom
| | - Desmond J Tobin
- Centre for Skin Sciences, Faculty of Life Sciences, University of Bradford, Bradford, BD7 1DP, United Kingdom
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37
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Grant CA, Twigg PC, Tobin DJ. Nano-scale observations of tattoo pigments in skin by atomic force microscopy. Curr Probl Dermatol 2015; 48:97-102. [PMID: 25833630 DOI: 10.1159/000369187] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/16/2023]
Abstract
In this study, we have shown how particles in carbon black tattoo ink accumulate in the human skin dermis using fine-resolution atomic force microscopy, with which a single ink particle in the collagenous network can be imaged. This information further demonstrates that tattoo inks are nano-particles. Further, we have deposited a commercially available tattoo ink on a glass slide and calculated a range of volumes for single ink particles.
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Affiliation(s)
- Colin A Grant
- Department of Medical Engineering, Faculty of Engineering and Informatics, University of Bradford, Bradford, UK
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38
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Hardman JA, Tobin DJ, Haslam IS, Farjo N, Farjo B, Al-Nuaimi Y, Grimaldi B, Paus R. The peripheral clock regulates human pigmentation. J Invest Dermatol 2015; 135:1053-1064. [PMID: 25310406 DOI: 10.1038/jid.2014.442] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2014] [Revised: 09/15/2014] [Accepted: 09/24/2014] [Indexed: 12/20/2022]
Abstract
Although the regulation of pigmentation is well characterized, it remains unclear whether cell-autonomous controls regulate the cyclic on-off switching of pigmentation in the hair follicle (HF). As human HFs and epidermal melanocytes express clock genes and proteins, and given that core clock genes (PER1, BMAL1) modulate human HF cycling, we investigated whether peripheral clock activity influences human HF pigmentation. We found that silencing BMAL1 or PER1 in human HFs increased HF melanin content. Furthermore, tyrosinase expression and activity, as well as TYRP1 and TYRP2 mRNA levels, gp100 protein expression, melanocyte dendricity, and the number gp100+ HF melanocytes, were all significantly increased in BMAL1 and/or PER1-silenced HFs. BMAL1 or PER1 silencing also increased epidermal melanin content, gp100 protein expression, and tyrosinase activity in human skin. These effects reflect direct modulation of melanocytes, as BMAL1 and/or PER1 silencing in isolated melanocytes increased tyrosinase activity and TYRP1/2 expression. Mechanistically, BMAL1 knockdown reduces PER1 transcription, and PER1 silencing induces phosphorylation of the master regulator of melanogenesis, microphthalmia-associated transcription factor, thus stimulating human melanogenesis and melanocyte activity in situ and in vitro. Therefore, the molecular clock operates as a cell-autonomous modulator of human pigmentation and may be targeted for future therapeutic strategies.
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Affiliation(s)
- Jonathan A Hardman
- The Centre for Dermatology Research, Institute of Inflammation and Repair, University of Manchester, Manchester, UK; Doctoral Training Centre in Integrative Systems Biology, Manchester Institute of Biotechnology, University of Manchester, Manchester, UK
| | - Desmond J Tobin
- Centre for Skin Sciences, School of Life Sciences, University of Bradford, Bradford, UK
| | - Iain S Haslam
- The Centre for Dermatology Research, Institute of Inflammation and Repair, University of Manchester, Manchester, UK
| | | | | | - Yusur Al-Nuaimi
- The Centre for Dermatology Research, Institute of Inflammation and Repair, University of Manchester, Manchester, UK
| | - Benedetto Grimaldi
- Department of Drug Discovery and Development, Instituto Italiano di Tecnologia (IIT), Genoa, Italy
| | - Ralf Paus
- The Centre for Dermatology Research, Institute of Inflammation and Repair, University of Manchester, Manchester, UK; Department of Dermatology, University of Muenster, Muenster, Germany.
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Abstract
Humans are social animals that communicate disproportionately via potent genetic signals imbued in the skin and hair, including racial, ethnic, health, gender, and age status. For the vast majority of us, age-related hair pigment loss becomes the inescapable signal of our disappearing youth. The hair follicle (HF) pigmentary unit is a wonderful tissue for studying mechanisms generally regulating aging, often before this becomes evident elsewhere in the body. Given that follicular melanocytes (unlike those in the epidermis) are regulated by the hair growth cycle, this cycle is likely to impact the process of aging in the HF pigmentary unit. The formal identification of melanocyte stem cells in the mouse skin has spurred a flurry of reports on the potential involvement of melanocyte stem cell depletion in hair graying (i.e., canities). Caution is recommended, however, against simple extrapolation of murine data to humans. Regardless, hair graying in both species is likely to involve an age-related imbalance in the tissue's oxidative stress handling that will impact not only melanogenesis but also melanocyte stem cell and melanocyte homeostasis and survival. There is some emerging evidence that the HF pigmentary unit may have regenerative potential, even after it has begun to produce white hair fibers. It may therefore be feasible to develop strategies to modulate some aging-associated changes to maintain melanin production for longer.
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Affiliation(s)
- Desmond J Tobin
- Centre for Skin Sciences, Faculty of Life Sciences, University of Bradford, Bradford, West Yorkshire, UK
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40
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Zhang CF, Gruber F, Ni C, Mildner M, Koenig U, Karner S, Barresi C, Rossiter H, Narzt MS, Nagelreiter IM, Larue L, Tobin DJ, Eckhart L, Tschachler E. Suppression of autophagy dysregulates the antioxidant response and causes premature senescence of melanocytes. J Invest Dermatol 2014; 135:1348-1357. [PMID: 25290687 DOI: 10.1038/jid.2014.439] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2014] [Revised: 09/22/2014] [Accepted: 09/24/2014] [Indexed: 01/03/2023]
Abstract
Autophagy is the central cellular mechanism for delivering organelles and cytoplasm to lysosomes for degradation and recycling of their molecular components. To determine the contribution of autophagy to melanocyte (MC) biology, we inactivated the essential autophagy gene Atg7 specifically in MCs using the Cre-loxP system. This gene deletion efficiently suppressed a key step in autophagy, lipidation of microtubule-associated protein 1 light chain 3 beta (LC3), in MCs and induced slight hypopigmentation of the epidermis in mice. The melanin content of hair was decreased by 10-15% in mice with autophagy-deficient MC as compared with control animals. When cultured in vitro, MCs from mutant and control mice produced equal amounts of melanin per cell. However, Atg7-deficient MCs entered into premature growth arrest and accumulated reactive oxygen species (ROS) damage, ubiquitinated proteins, and the multi-functional adapter protein SQSTM1/p62. Moreover, nuclear factor erythroid 2-related factor 2 (Nrf2)-dependent expression of NAD(P)H dehydrogenase, quinone 1, and glutathione S-transferase Mu 1 was increased, indicating a contribution of autophagy to redox homeostasis in MCs. In summary, the results of our study suggest that Atg7-dependent autophagy is dispensable for melanogenesis but necessary for achieving the full proliferative capacity of MCs.
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Affiliation(s)
- Cheng-Feng Zhang
- Research Division of Biology and Pathobiology of the Skin, Department of Dermatology, Medical University of Vienna, Vienna, Austria; Department of Dermatology, Huashan Hospital, Fu Dan University, Shanghai, China
| | - Florian Gruber
- Research Division of Biology and Pathobiology of the Skin, Department of Dermatology, Medical University of Vienna, Vienna, Austria; Christian Doppler Laboratory for Biotechnology of Skin Aging, Department of Dermatology, Medical University of Vienna, Vienna, Austria.
| | - Chunya Ni
- Research Division of Biology and Pathobiology of the Skin, Department of Dermatology, Medical University of Vienna, Vienna, Austria; Department of Dermatology, Huashan Hospital, Fu Dan University, Shanghai, China
| | - Michael Mildner
- Research Division of Biology and Pathobiology of the Skin, Department of Dermatology, Medical University of Vienna, Vienna, Austria
| | - Ulrich Koenig
- Research Division of Biology and Pathobiology of the Skin, Department of Dermatology, Medical University of Vienna, Vienna, Austria
| | - Susanne Karner
- Research Division of Biology and Pathobiology of the Skin, Department of Dermatology, Medical University of Vienna, Vienna, Austria
| | - Caterina Barresi
- Research Division of Biology and Pathobiology of the Skin, Department of Dermatology, Medical University of Vienna, Vienna, Austria
| | - Heidemarie Rossiter
- Research Division of Biology and Pathobiology of the Skin, Department of Dermatology, Medical University of Vienna, Vienna, Austria
| | - Marie-Sophie Narzt
- Research Division of Biology and Pathobiology of the Skin, Department of Dermatology, Medical University of Vienna, Vienna, Austria; Christian Doppler Laboratory for Biotechnology of Skin Aging, Department of Dermatology, Medical University of Vienna, Vienna, Austria
| | - Ionela M Nagelreiter
- Research Division of Biology and Pathobiology of the Skin, Department of Dermatology, Medical University of Vienna, Vienna, Austria; Christian Doppler Laboratory for Biotechnology of Skin Aging, Department of Dermatology, Medical University of Vienna, Vienna, Austria
| | - Lionel Larue
- Institut Curie, Centre de Recherche, Developmental Genetics of Melanocytes, Orsay, France; CNRS UMR3347, Orsay, France; INSERM U1021, Orsay, France
| | - Desmond J Tobin
- Centre for Skin Sciences, School of Life Sciences, University of Bradford, Bradford, UK
| | - Leopold Eckhart
- Research Division of Biology and Pathobiology of the Skin, Department of Dermatology, Medical University of Vienna, Vienna, Austria
| | - Erwin Tschachler
- Research Division of Biology and Pathobiology of the Skin, Department of Dermatology, Medical University of Vienna, Vienna, Austria.
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41
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Affiliation(s)
- Desmond J. Tobin
- Centre for Skin Sciences; School of Life Sciences; University of Bradford; Bradford West Yorkshire Great Britain
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42
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Pedersen JS, Valen E, Velazquez AMV, Parker BJ, Rasmussen M, Lindgreen S, Lilje B, Tobin DJ, Kelly TK, Vang S, Andersson R, Jones PA, Hoover CA, Tikhonov A, Prokhortchouk E, Rubin EM, Sandelin A, Gilbert MTP, Krogh A, Willerslev E, Orlando L. Genome-wide nucleosome map and cytosine methylation levels of an ancient human genome. Genome Res 2013; 24:454-66. [PMID: 24299735 PMCID: PMC3941110 DOI: 10.1101/gr.163592.113] [Citation(s) in RCA: 109] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Epigenetic information is available from contemporary organisms, but is difficult to track back in evolutionary time. Here, we show that genome-wide epigenetic information can be gathered directly from next-generation sequence reads of DNA isolated from ancient remains. Using the genome sequence data generated from hair shafts of a 4000-yr-old Paleo-Eskimo belonging to the Saqqaq culture, we generate the first ancient nucleosome map coupled with a genome-wide survey of cytosine methylation levels. The validity of both nucleosome map and methylation levels were confirmed by the recovery of the expected signals at promoter regions, exon/intron boundaries, and CTCF sites. The top-scoring nucleosome calls revealed distinct DNA positioning biases, attesting to nucleotide-level accuracy. The ancient methylation levels exhibited high conservation over time, clustering closely with modern hair tissues. Using ancient methylation information, we estimated the age at death of the Saqqaq individual and illustrate how epigenetic information can be used to infer ancient gene expression. Similar epigenetic signatures were found in other fossil material, such as 110,000- to 130,000-yr-old bones, supporting the contention that ancient epigenomic information can be reconstructed from a deep past. Our findings lay the foundation for extracting epigenomic information from ancient samples, allowing shifts in epialleles to be tracked through evolutionary time, as well as providing an original window into modern epigenomics.
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Affiliation(s)
- Jakob Skou Pedersen
- Department of Molecular Medicine (MOMA), Aarhus University Hospital, Skejby, DK-8200 Aarhus N, Denmark
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43
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Slominski AT, Zmijewski MA, Zbytek B, Tobin DJ, Theoharides TC, Rivier J. Key role of CRF in the skin stress response system. Endocr Rev 2013; 34:827-84. [PMID: 23939821 PMCID: PMC3857130 DOI: 10.1210/er.2012-1092] [Citation(s) in RCA: 273] [Impact Index Per Article: 24.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/30/2012] [Accepted: 08/02/2013] [Indexed: 02/08/2023]
Abstract
The discovery of corticotropin-releasing factor (CRF) or CRH defining the upper regulatory arm of the hypothalamic-pituitary-adrenal (HPA) axis, along with the identification of the corresponding receptors (CRFRs 1 and 2), represents a milestone in our understanding of central mechanisms regulating body and local homeostasis. We focused on the CRF-led signaling systems in the skin and offer a model for regulation of peripheral homeostasis based on the interaction of CRF and the structurally related urocortins with corresponding receptors and the resulting direct or indirect phenotypic effects that include regulation of epidermal barrier function, skin immune, pigmentary, adnexal, and dermal functions necessary to maintain local and systemic homeostasis. The regulatory modes of action include the classical CRF-led cutaneous equivalent of the central HPA axis, the expression and function of CRF and related peptides, and the stimulation of pro-opiomelanocortin peptides or cytokines. The key regulatory role is assigned to the CRFR-1α receptor, with other isoforms having modulatory effects. CRF can be released from sensory nerves and immune cells in response to emotional and environmental stressors. The expression sequence of peptides includes urocortin/CRF→pro-opiomelanocortin→ACTH, MSH, and β-endorphin. Expression of these peptides and of CRFR-1α is environmentally regulated, and their dysfunction can lead to skin and systemic diseases. Environmentally stressed skin can activate both the central and local HPA axis through either sensory nerves or humoral factors to turn on homeostatic responses counteracting cutaneous and systemic environmental damage. CRF and CRFR-1 may constitute novel targets through the use of specific agonists or antagonists, especially for therapy of skin diseases that worsen with stress, such as atopic dermatitis and psoriasis.
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Affiliation(s)
- Andrzej T Slominski
- MD, PhD, Department of Pathology and Laboratory Medicine, University of Tennessee Health Science Center; 930 Madison Avenue, Suite 500, Memphis, Tennessee 38163.
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44
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Singh SK, Baker R, Wibawa JID, Bell M, Tobin DJ. The effects of Sophora angustifolia and other natural plant extracts on melanogenesis and melanin transfer in human skin cells. Exp Dermatol 2013; 22:67-9. [PMID: 23278898 DOI: 10.1111/exd.12061] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/29/2012] [Indexed: 12/23/2022]
Abstract
Skin pigmentation is a multistep process of melanin synthesis by melanocytes, its transfer to recipient keratinocytes and its degradation. As dyspigmentation is a prominent marker of skin ageing, novel effective agents that modulate pigmentation safely are being sought for both clinical and cosmetic use. Here, a number of plant extracts were examined for their effect on melanogenesis (by melanin assay and Western blotting) and melanin transfer (by confocal immunomicroscopy of gp100-positive melanin granules in cocultures and by SEM analysis of filopodia), in human melanocytes and in cocultures with phototype-matched normal adult epidermal keratinocytes. Mulberry, Kiwi and Sophora extracts were assessed against isobutylmethylxanthine, hydroquinone, vitamin C and niacinamide. Compared with unstimulated control, all extracts significantly reduced melanogenesis in human melanoma cells and normal adult epidermal melanocytes. These extracts also reduced melanin transfer and reduced filopodia expression on melanocytes, similar to hydroquinone and niacinamide, indicating their effectiveness as multimode pigmentation actives.
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45
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Affiliation(s)
- Gillian E Westgate
- Centre for Skin Sciences; School of Life Sciences; University of Bradford; Richmond Road Bradford West Yorkshire BD7 1DP UK
- Westgate Consultancy Ltd; Court Lane Stevington Bedfordshire MK43 7QT UK
| | - Natalia V Botchkareva
- Centre for Skin Sciences; School of Life Sciences; University of Bradford; Richmond Road Bradford West Yorkshire BD7 1DP UK
| | - Desmond J Tobin
- Centre for Skin Sciences; School of Life Sciences; University of Bradford; Richmond Road Bradford West Yorkshire BD7 1DP UK
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46
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Liu W, Peng Y, Tobin DJ. A new 12-gene diagnostic biomarker signature of melanoma revealed by integrated microarray analysis. PeerJ 2013; 1:e49. [PMID: 23638386 PMCID: PMC3628745 DOI: 10.7717/peerj.49] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2012] [Accepted: 02/20/2013] [Indexed: 12/16/2022] Open
Abstract
Genome-wide microarray technology has facilitated the systematic discovery of diagnostic biomarkers of cancers and other pathologies. However, meta-analyses of published arrays often uncover significant inconsistencies that hinder advances in clinical practice. Here we present an integrated microarray analysis framework, based on a genome-wide relative significance (GWRS) and genome-wide global significance (GWGS) model. When applied to five microarray datasets on melanoma published between 2000 and 2011, this method revealed a new signature of 200 genes. When these were linked to so-called ‘melanoma driver’ genes involved in MAPK, Ca2+, and WNT signaling pathways we were able to produce a new 12-gene diagnostic biomarker signature for melanoma (i.e., EGFR, FGFR2, FGFR3, IL8, PTPRF, TNC, CXCL13, COL11A1, CHP2, SHC4, PPP2R2C, and WNT4). We have begun to experimentally validate a subset of these genes involved in MAPK signaling at the protein level, including CXCL13, COL11A1, PTPRF and SHC4 and found these to be over-expressed in metastatic and primary melanoma cells in vitro and in situ compared to melanocytes cultured from healthy skin epidermis and normal healthy human skin. While SHC4 has been reported previously to be associated to melanoma, this is the first time CXCL13, COL11A1, and PTPRF have been associated with melanoma on experimental validation. Our computational evaluation indicates that this 12-gene biomarker signature achieves excellent diagnostic power in distinguishing metastatic melanoma from normal skin and benign nevus. Further experimental validation of the role of these 12 genes in a new signaling network may provide new insights into the underlying biological mechanisms driving the progression of melanoma.
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Affiliation(s)
- Wanting Liu
- Department of Computing, University of Bradford , Great Britain ; Centre of Skin Sciences, University of Bradford , Great Britain
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47
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Abstract
Bone morphogenetic proteins (BMPs) are a large family of multi-functional secreted signalling molecules. Previously BMP2/4 were shown to inhibit skin pigmentation by downregulating tyrosinase expression and activity in epidermal melanocytes. However, a possible role for other BMP family members and their antagonists in melanogenesis has not yet been explored. In this study we show that BMP4 and BMP6, from two different BMP subclasses, and their antagonists noggin and sclerostin were variably expressed in melanocytes and keratinocytes in human skin. We further examined their involvement in melanogenesis and melanin transfer using fully matched primary cultures of adult human melanocytes and keratinocytes. BMP6 markedly stimulated melanogenesis by upregulating tyrosinase expression and activity, and also stimulated the formation of filopodia and Myosin-X expression in melanocytes, which was associated with increased melanosome transfer from melanocytes to keratinocytes. BMP4, by contrast, inhibited melanin synthesis and transfer to below baseline levels. These findings were confirmed using siRNA knockdown of BMP receptors BMPR1A/1B or of Myosin-X, as well as by incubating cells with the antagonists noggin and sclerostin. While BMP6 was found to use the p38MAPK pathway to regulate melanogenesis in human melanocytes independently of the Smad pathway, p38MAPK, PI3-K and Smad pathways were all involved in BMP6-mediated melanin transfer. This suggests that pigment formation may be regulated independently of pigment transfer. These data reveal a complex involvement of regulation of different members of the BMP family, their antagonists and inhibitory Smads, in melanocytes behaviour.
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Affiliation(s)
- Suman K Singh
- Centre for Skin Sciences, School of Life Sciences, University of Bradford, Bradford, West Yorkshire, BD7 1DP, UK
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48
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Baris OR, Klose A, Kloepper JE, Weiland D, Neuhaus JFG, Schauen M, Wille A, Müller A, Merkwirth C, Langer T, Larsson NG, Krieg T, Tobin DJ, Paus R, Wiesner RJ. The mitochondrial electron transport chain is dispensable for proliferation and differentiation of epidermal progenitor cells. Stem Cells 2012; 29:1459-68. [PMID: 21780252 DOI: 10.1002/stem.695] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Tissue stem cells and germ line or embryonic stem cells were shown to have reduced oxidative metabolism, which was proposed to be an adaptive mechanism to reduce damage accumulation caused by reactive oxygen species. However, an alternate explanation is that stem cells are less dependent on specialized cytoplasmic functions compared with differentiated cells, therefore, having a high nuclear-to-cytoplasmic volume ratio and consequently a low mitochondrial content. To determine whether stem cells rely or not on mitochondrial respiration, we selectively ablated the electron transport chain in the basal layer of the epidermis, which includes the epidermal progenitor/stem cells (EPSCs). This was achieved using a loxP-flanked mitochondrial transcription factor A (Tfam) allele in conjunction with a keratin 14 Cre transgene. The epidermis of these animals (Tfam(EKO)) showed a profound depletion of mitochondrial DNA and complete absence of respiratory chain complexes. However, despite a short lifespan due to malnutrition, epidermal development and skin barrier function were not impaired. Differentiation of epidermal layers was normal and no proliferation defect or major increase of apoptosis could be observed. In contrast, mice with an epidermal ablation of prohibitin-2, a scaffold protein in the inner mitochondrial membrane, displayed a dramatic phenotype observable already in utero, with severely impaired skin architecture and barrier function, ultimately causing death from dehydration shortly after birth. In conclusion, we here provide unequivocal evidence that EPSCs, and probably tissue stem cells in general, are independent of the mitochondrial respiratory chain, but still require a functional dynamic mitochondrial compartment.
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Affiliation(s)
- Olivier R Baris
- Center for Physiology and Pathophysiology, Institute for Vegetative Physiology,University of Cologne, Cologne, Germany
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49
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Sharma V, Singh SK, Anderson D, Tobin DJ, Dhawan A. Zinc oxide nanoparticle induced genotoxicity in primary human epidermal keratinocytes. J Nanosci Nanotechnol 2011; 11:3782-8. [PMID: 21780369 DOI: 10.1166/jnn.2011.4250] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
Zinc oxide (ZnO) nanoparticles are widely used in cosmetics and sunscreens. Human epidermal keratinocytes may serve as the first portal of entry for these nanoparticles either directly through topically applied cosmetics or indirectly through any breaches in the skin integrity. Therefore, the objective of the present study was to assess the biological interactions of ZnO nanoparticles in primary human epidermal keratinocytes (HEK) as they are the most abundant cell type in the human epidermis. Cellular uptake of nanoparticles was investigated by scanning electron microscopy using back scattered electrons imaging as well as transmission electron microscopy. The electron microscopy revealed the internalization of ZnO nanoparticles in primary HEK after 6 h exposure at 14 microg/ml concentration. ZnO nanoparticles exhibited a time (6-24 h) as well as concentration (8-20 microg/ml) dependent inhibition of mitochondrial activity as evident by the MTT assay. A significant (p < 0.05) induction in DNA damage was observed in cells exposed to ZnO nanoparticles for 6 h at 8 and 14 microg/ml concentrations compared to control as evident in the Comet assay. This is the first study providing information on biological interactions of ZnO nanoparticles with primary human epidermal keratinocytes. Our findings demonstrate that ZnO nanoparticles are internalized by the human epidermal keratinocytes and elicit a cytotoxic and genotoxic response. Therefore, caution should be taken while using consumer products containing nanoparticles as any perturbation in the skin barrier could expose the underlying cells to nanoparticles.
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Affiliation(s)
- Vyom Sharma
- Nanomaterial Toxicology Group, Indian Institute of Toxicology Research, Council of Scientific and Industrial Research (CSIR), Mahatma Gandhi Marg, P.O. Box 80, Lucknow 226001, Uttar Pradesh, India
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Bengtsson CF, Olsen ME, Brandt LØ, Bertelsen MF, Willerslev E, Tobin DJ, Wilson AS, Gilbert MTP. DNA from keratinous tissue. Part I: hair and nail. Ann Anat 2011; 194:17-25. [PMID: 21530205 DOI: 10.1016/j.aanat.2011.03.013] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2010] [Revised: 03/05/2011] [Accepted: 03/22/2011] [Indexed: 11/26/2022]
Abstract
Keratinous tissues such as nail, hair, horn, scales and feather have been used as a source of DNA for over 20 years. Particular benefits of such tissues include the ease with which they can be sampled, the relative stability of DNA in such tissues once sampled, and, in the context of ancient genetic analyses, the fact that sampling generally causes minimal visual damage to valuable specimens. Even when freshly sampled, however, the DNA quantity and quality in the fully keratinized parts of such tissues is extremely poor in comparison to other tissues such as blood and muscle - although little systematic research has been undertaken to characterize how such degradation may relate to sample source. In this review paper we present the current understanding of the quality and limitations of DNA in two key keratinous tissues, nail and hair. The findings indicate that although some fragments of nuclear and mitochondrial DNA appear to be present in almost all hair and nail samples, the quality of DNA, both in quantity and length of amplifiable DNA fragments, vary considerably not just by species, but by individual, and even within individual between hair types.
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Affiliation(s)
- Camilla Friis Bengtsson
- Centre for GeoGenetics, Natural History Museum of Denmark, University of Copenhagen, Denmark
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