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Hülpüsch C, Rohayem R, Reiger M, Traidl-Hoffmann C. Exploring the skin microbiome in atopic dermatitis pathogenesis and disease modification. J Allergy Clin Immunol 2024; 154:31-41. [PMID: 38761999 DOI: 10.1016/j.jaci.2024.04.029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Revised: 03/04/2024] [Accepted: 04/24/2024] [Indexed: 05/20/2024]
Abstract
Inflammatory skin diseases such as atopic eczema (atopic dermatitis [AD]) affect children and adults globally. In AD, the skin barrier is impaired on multiple levels. Underlying factors include genetic, chemical, immunologic, and microbial components. Increased skin pH in AD is part of the altered microbial microenvironment that promotes overgrowth of the skin microbiome with Staphylococcus aureus. The secretion of virulence factors, such as toxins and proteases, by S aureus further aggravates the skin barrier deficiency and additionally disrupts the balance of an already skewed immune response. Skin commensal bacteria, however, can inhibit the growth and pathogenicity of S aureus through quorum sensing. Therefore, restoring a healthy skin microbiome could contribute to remission induction in AD. This review discusses direct and indirect approaches to targeting the skin microbiome through modulation of the skin pH; UV treatment; and use of prebiotics, probiotics, and postbiotics. Furthermore, exploratory techniques such as skin microbiome transplantation, ozone therapy, and phage therapy are discussed. Finally, we summarize the latest findings on disease and microbiome modification through targeted immunomodulatory systemic treatments and biologics. We believe that targeting the skin microbiome should be considered a crucial component of successful AD treatment in the future.
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Affiliation(s)
- Claudia Hülpüsch
- Environmental Medicine, Faculty of Medicine, University of Augsburg, Augsburg, Germany; Institute of Environmental Medicine, Helmholtz Center Munich-German Research Center for Environmental Health, Augsburg, Germany; Christine-Kühne Center for Allergy Research and Education, Davos, Switzerland
| | - Robin Rohayem
- Environmental Medicine, Faculty of Medicine, University of Augsburg, Augsburg, Germany; Christine-Kühne Center for Allergy Research and Education, Davos, Switzerland; Dermatology, Faculty of Medicine, University of Augsburg, Augsburg, Germany
| | - Matthias Reiger
- Environmental Medicine, Faculty of Medicine, University of Augsburg, Augsburg, Germany; Institute of Environmental Medicine, Helmholtz Center Munich-German Research Center for Environmental Health, Augsburg, Germany
| | - Claudia Traidl-Hoffmann
- Environmental Medicine, Faculty of Medicine, University of Augsburg, Augsburg, Germany; Chair of Environmental Medicine, Technical University of Munich, Munich, Germany; Institute of Environmental Medicine, Helmholtz Center Munich-German Research Center for Environmental Health, Augsburg, Germany; Christine-Kühne Center for Allergy Research and Education, Davos, Switzerland; ZIEL-Institute for Food & Health, Technical University of Munich, Freising, Germany.
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2
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Fluhr JW, Moore DJ, Lane ME, Lachmann N, Rawlings AV. Epidermal barrier function in dry, flaky and sensitive skin: A narrative review. J Eur Acad Dermatol Venereol 2024; 38:812-820. [PMID: 38140732 DOI: 10.1111/jdv.19745] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2023] [Accepted: 11/17/2023] [Indexed: 12/24/2023]
Abstract
The stratum corneum (SC)-the outermost layer of the epidermis-is the principal permeability and protective barrier of the skin. Different components of the SC, including corneocytes, natural moisturizing factor, a variety of enzymes and their inhibitors, antimicrobial peptides and lipids, work interactively to maintain barrier function. The main barrier properties of the SC are the limitation of water loss and the prevention of infection and contact with potentially harmful exogenous factors. Although the SC functions consistently as a protective barrier throughout the body, variations in functions and morphology occur across body sites with age and skin type. Healthy SC function also depends on the interplay between the chemosensory barrier, the skin's microbiome and the innate immune system. Dysregulation of SC barrier function can lead to the development of skin disorders, such as dry, flaky or sensitive skin, but the complete underlying pathophysiology of these are not fully understood. This review provides insight into the current literature and emerging themes related to epidermal barrier changes that occur in the context of dry, flaky and sensitive skin. Additional studies are needed to further elucidate the underlying aetiology of dry, flaky and sensitive skin and to provide tailored treatment.
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Affiliation(s)
- Joachim W Fluhr
- Institute of Allergology IFA Charité Universitätsmedizin, Berlin, Germany
- Fraunhofer Institute for Translational Medicine and Pharmacology ITMP, Allergology and Immunology, Berlin, Germany
| | | | - Majella E Lane
- Department of Pharmaceutics, UCL School of Pharmacy, London, UK
| | | | - Anthony V Rawlings
- Department of Pharmaceutics, UCL School of Pharmacy, London, UK
- AVR Consulting Ltd., Northwich, UK
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3
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Stefanovic N, Irvine AD. Filaggrin and beyond: New insights into the skin barrier in atopic dermatitis and allergic diseases, from genetics to therapeutic perspectives. Ann Allergy Asthma Immunol 2024; 132:187-195. [PMID: 37758055 DOI: 10.1016/j.anai.2023.09.009] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2023] [Revised: 08/22/2023] [Accepted: 09/19/2023] [Indexed: 10/03/2023]
Abstract
Atopic dermatitis (AD) is the most common inflammatory skin disease worldwide, affecting 20% of children and 5% of adults. One critical component in the pathophysiology of AD is the epidermal skin barrier, with its outermost layer, the stratum corneum (SC), conferring biochemical properties that enable resilience against environmental threats and maintain homeostasis. The skin barrier may be conceptualized as a key facilitator of complex interactions between genetics, host immunity, the cutaneous microbiome, and environmental exposures. The key genetic risk factor for AD development and persistence is a loss-of-function mutation in FLG, with recent advances in genomics focusing on rare variant discovery, establishment of pathogenic mechanisms, and exploration of the role of other epidermal differentiation complex gene variants in AD. Aberrant type 2 inflammatory responses down-regulate the transcription of key epidermal barrier genes, alter the composition of SC lipids, and induce further injury through a neurocutaneous feedback loop and the itch-scratch cycle. The dysbiotic epidermis exhibits reduced bacterial diversity and enhanced colonization with Staphylococcus and Malassezia species, which contribute to both direct barrier injury through the action of bacterial toxins and perpetuation of the inflammatory cascades. Enhanced understanding of each of the pathogenic mechanisms underpinning barrier disruption has led to the development of novel topical and systemic molecules, including interleukin (IL)-4Ra, IL-13, PDE4, and Janus-associated kinase inhibitors, whose clinical effectiveness exceeds conventional treatment modalities. In this narrative review, we aim to summarize the current understanding of the above-mentioned pathophysiological and therapeutic mechanisms, with a focus on the genetic, cellular, and molecular mechanisms underpinning AD development.
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Affiliation(s)
| | - Alan D Irvine
- Clinical Medicine, Trinity College Dublin, Dublin, Ireland.
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4
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Woo YR, Kim HS. Interaction between the microbiota and the skin barrier in aging skin: a comprehensive review. Front Physiol 2024; 15:1322205. [PMID: 38312314 PMCID: PMC10834687 DOI: 10.3389/fphys.2024.1322205] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2023] [Accepted: 01/03/2024] [Indexed: 02/06/2024] Open
Abstract
The interplay between the microbes and the skin barrier holds pivotal significance in skin health and aging. The skin and gut, both of which are critical immune and neuroendocrine system, harbor microbes that are kept in balance. Microbial shifts are seen with aging and may accelerate age-related skin changes. This comprehensive review investigates the intricate connection between microbe dynamics, skin barrier, and the aging process. The gut microbe plays essential roles in the human body, safeguarding the host, modulating metabolism, and shaping immunity. Aging can perturb the gut microbiome which in turn accentuates inflammaging by further promoting senescent cell accumulation and compromising the host's immune response. Skin microbiota diligently upholds the epidermal barrier, adeptly fending off pathogens. The aging skin encompasses alterations in the stratum corneum structure and lipid content, which negatively impact the skin's barrier function with decreased moisture retention and increased vulnerability to infection. Efficacious restoration of the skin barrier and dysbiosis with strategic integration of acidic cleansers, emollients with optimal lipid composition, antioxidants, and judicious photoprotection may be a proactive approach to aging. Furthermore, modulation of the gut-skin axis through probiotics, prebiotics, and postbiotics emerges as a promising avenue to enhance skin health as studies have substantiated their efficacy in enhancing hydration, reducing wrinkles, and fortifying barrier integrity. In summary, the intricate interplay between microbes and skin barrier function is intrinsically woven into the tapestry of aging. Sound understanding of these interactions, coupled with strategic interventions aimed at recalibrating the microbiota and barrier equilibrium, holds the potential to ameliorate skin aging. Further in-depth studies are necessary to better understand skin-aging and develop targeted strategies for successful aging.
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Affiliation(s)
- Yu Ri Woo
- Department of Dermatology, Incheon St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
| | - Hei Sung Kim
- Department of Dermatology, Incheon St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
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5
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Évora AS, Abiakam N, Zhang Z, Johnson SA, Adams MJ, Bader DL, Worsley PR. Characterisation of superficial corneocyte properties over category I pressure ulcers: Insights into topographical and maturation changes. J Dermatol Sci 2023; 112:63-70. [PMID: 37953180 DOI: 10.1016/j.jdermsci.2023.08.008] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Revised: 08/19/2023] [Accepted: 08/31/2023] [Indexed: 11/14/2023]
Abstract
BACKGROUND Pressure ulcers (PUs) are chronic wounds that are detrimental to the quality of life of patients. Despite advances in monitoring skin changes, the structure and function of skin cells over the site of pressure ulcers are not fully understood. OBJECTIVE The present study aims to evaluate local changes in the properties of superficial corneocytes in category 1 PU sites sampled from a cohort of hospitalised patients. METHODS Cells were collected from a PU-compromised site and an adjacent control area and their topographical, maturation and mechanical properties were analysed. RESULTS Corneocytes at the PU-compromised site were characterised by higher levels of immature cornified envelopes (p < 0.001) and greater amounts of desmoglein-1 (corneodesmosomal protein) (p < 0.001) compared to the adjacent control area. The cells at the control site presented the typical ridges-and-valleys topographical features of sacrum corneocytes. By contrast, the PU cells presented circular nano-objects at the cell surface, and, for some patients, the cell topography was deformed. CEs at the PU site were also smaller than at the control site. Although differences were not observed in the mechanical properties of the cells, those of the elderly patients were much softer compared with young subjects. CONCLUSION This is the first study investigating the changes in corneocyte properties in category I pressure ulcers. Superficial cells at the PU sites showed altered topographical and maturation characteristics. Further studies are required to elucidate if these changes are a consequence of early loss of skin integrity or a result of mechanical and microclimate insults to the skin surface.
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Affiliation(s)
- Ana S Évora
- School of Chemical Engineering, University of Birmingham, Birmingham, UK.
| | - Nkemjika Abiakam
- School of Health Sciences, University of Southampton, Southampton, UK
| | - Zhibing Zhang
- School of Chemical Engineering, University of Birmingham, Birmingham, UK
| | - Simon A Johnson
- School of Chemical Engineering, University of Birmingham, Birmingham, UK
| | - Michael J Adams
- School of Chemical Engineering, University of Birmingham, Birmingham, UK
| | - Dan L Bader
- School of Health Sciences, University of Southampton, Southampton, UK
| | - Peter R Worsley
- School of Health Sciences, University of Southampton, Southampton, UK
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6
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de Boer FL, van der Molen HF, Kezic S. Epidermal biomarkers of the skin barrier in atopic and contact dermatitis. Contact Dermatitis 2023; 89:221-229. [PMID: 37571977 DOI: 10.1111/cod.14391] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2023] [Revised: 07/21/2023] [Accepted: 07/25/2023] [Indexed: 08/13/2023]
Abstract
Dysfunction of the skin barrier plays a critical role in the initiation and progression of inflammatory skin diseases, such as atopic dermatitis and contact dermatitis. Epidermal biomarkers can aid in evaluating the functionality of the skin barrier and understanding the mechanisms that underlay its impairment. This narrative review provides an overview of recent studies on epidermal biomarkers associated with the function and integrity of the skin barrier, and their application in research on atopic dermatitis and contact dermatitis. The reviewed studies encompass a wide spectrum of molecular, morphological and biophysical biomarkers, mainly obtained from stratum corneum tape strips and biopsies. Lipids, natural moisturizing factors, and structural proteins are the most frequently reported molecular biomarkers. Additionally, corneocyte surface topography and elasticity show potential as biomarkers for assessing the physical barrier of the skin. In contact dermatitis studies, biomarkers are commonly employed to evaluate skin irritation and differentiate between irritant and allergic contact dermatitis. In atopic dermatitis, biomarkers are primarily utilized to identify differences between atopic and healthy skin, for predictive purposes, and monitoring response to therapies. While this overview identifies potential biomarkers for the skin barrier, their validation as epidermal biomarkers for atopic dermatitis and contact dermatitis has yet to be established.
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Affiliation(s)
- F L de Boer
- Public and Occupational Health Department, Amsterdam UMC, University of Amsterdam, Amsterdam Public Health Research, Amsterdam, The Netherlands
| | - H F van der Molen
- Public and Occupational Health Department, Amsterdam UMC, University of Amsterdam, Amsterdam Public Health Research, Amsterdam, The Netherlands
| | - S Kezic
- Public and Occupational Health Department, Amsterdam UMC, University of Amsterdam, Amsterdam Public Health Research, Amsterdam, The Netherlands
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7
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Li R, Rodrigues M, Li L, Winget J, Wang Y, Wang C, Smith E, Wei K. Association Between Skin Acid Mantle, Natural Moisturizing Factors, and Antibacterial Activity Against S. aureus in the Stratum Corneum. Clin Cosmet Investig Dermatol 2023; 16:1595-1606. [PMID: 37378303 PMCID: PMC10292209 DOI: 10.2147/ccid.s409534] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2023] [Accepted: 06/16/2023] [Indexed: 06/29/2023]
Abstract
Purpose The skin has evolved a system to prevent pathogenic microorganism colonization and infection. This study examined the role of natural moisturizing factors (NMFs) and skin pH on Staphylococcus aureus (S. aureus) growth and colonization on the human stratum corneum (SC). Study Population and Methods A survey study with 82 female participants was performed. Participants maintained their daily hygiene routine, except for refraining from using leave-on products on their forearms on the day of the test. Skin sampling was performed using adhesive tapes. An ex vivo method was developed to study the viability and growth of S. aureus on human SC sampled from normal skin. NMFs, including pyrrolidone carboxylic acid (PCA), urocanic acid (UCA), histidine, and proline in SC samples, were measured by liquid chromatography with tandem mass spectrometry. The impact of PCA and UCA on S. aureus growth and metabolic activity was measured by optical density and isothermal microcalorimetry, respectively. Results Heterogeneity of S. aureus viability on human SC samples was observed. Skin pH showed a significant negative association (p<0.05) with SC antibacterial activity in the ex vivo assay. One unit of skin pH decrease corresponded to 68.1% of S. aureus cell death. The levels of PCA and histidine were significantly negatively associated (p<0.05) with skin pH. The addition of 5 mM and 10 mM PCA significantly inhibited S. aureus growth by approximately 25% at 20 hours and reduced its metabolic activity in vitro. Conclusion The results indicate that PCA, one of the NMFs in human skin, plays an important role in regulating the human skin acid mantle in vivo and contributes to antibacterial activity against S. aureus.
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Affiliation(s)
- Rui Li
- Beauty Revealed, Procter & Gamble International Operations SA SG Branch, Singapore, Singapore
| | - MyriamRubecca Rodrigues
- Beauty Revealed, Procter & Gamble International Operations SA SG Branch, Singapore, Singapore
| | - Lijuan Li
- Corporate Functions Analytical, Procter & Gamble Mason Business Center, Cincinnati, OH, USA
| | - Jason Winget
- Corporate Functions Analytical, Procter & Gamble Mason Business Center, Cincinnati, OH, USA
| | - Yu Wang
- Beauty Revealed, Procter & Gamble International Operations SA SG Branch, Singapore, Singapore
| | - Caroline Wang
- Beauty Revealed, Procter & Gamble International Operations SA SG Branch, Singapore, Singapore
| | - Ed Smith
- Personal Care, Procter & Gamble Mason Business Center, Cincinnati, OH, USA
| | - Karl Wei
- Personal Care, Procter & Gamble Mason Business Center, Cincinnati, OH, USA
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Beck LA, Bieber T, Weidinger S, Tauber M, Saeki H, Irvine AD, Eichenfield LF, Werfel T, Arlert P, Jiang L, Røpke M, Paller AS. Tralokinumab treatment improves the skin microbiota by increasing the microbial diversity in adults with moderate-to-severe atopic dermatitis: Analysis of microbial diversity in ECZTRA 1, a randomized controlled trial. J Am Acad Dermatol 2023; 88:816-823. [PMID: 36473633 DOI: 10.1016/j.jaad.2022.11.047] [Citation(s) in RCA: 18] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Revised: 11/08/2022] [Accepted: 11/20/2022] [Indexed: 12/12/2022]
Abstract
BACKGROUND Atopic dermatitis (AD) is characterized by microbial dysbiosis, immune dysregulation, and an impaired skin barrier. Microbial dysbiosis in AD involves a reduction in diversity primarily driven by an increased abundance of Staphylococcus aureus. Tralokinumab, an approved treatment for adults with moderate-to-severe AD, improves the skin barrier and immune abnormalities by specifically targeting the interleukin 13 cytokine, but its impact on the skin microbiome is unknown. OBJECTIVE To investigate how tralokinumab affects the skin microbiome by examining the lesional skin of adults with moderate-to-severe AD from the phase 3 ECZTRA 1 trial (NCT03131648). METHODS Microbiome profiling, S aureus abundance, and biomarker data were assessed in a subset of ECZTRA 1 participants (S aureus abundance at baseline and week 16; microbiome profiling at baseline, and week 8/16; and serum sampling before dose and week 4/8/16/28/52). RESULTS Tralokinumab treatment led to increased microbial diversity, reduced S aureus abundance, and increased abundance of the commensal coagulase-negative Staphylococci. LIMITATIONS Limitations include a lack of S aureus abundance data at week 8, sampling site variation between participants, and possible influence from concomitant systemic antiinfectives. CONCLUSION Our findings indicate specific targeting of the interleukin 13 cytokine with tralokinumab can directly and/or indirectly improve microbial dysbiosis seen in AD skin.
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Affiliation(s)
- Lisa A Beck
- Department of Dermatology, Medicine and Pathology, University of Rochester Medical Center, Rochester, New York.
| | - Thomas Bieber
- Department of Dermatology and Allergy, University Hospital, Bonn, Germany; Christine Kühne-Center for Allergy Research and Education, Davos, Switzerland
| | - Stephan Weidinger
- Department of Dermatology and Allergy, University Hospital Schleswig-Holstein, Campus Kiel, Kiel, Germany
| | - Marie Tauber
- Dermatology and Allergology Department, Toulouse University Hospital and Inserm UMR1291 - CNRS UMR5051, Toulouse, France
| | - Hidehisa Saeki
- Department of Dermatology, Nippon Medical School, Tokyo, Japan
| | - Alan D Irvine
- Clinical Medicine, Trinity College Dublin, Ireland; Department of Dermatology, Children's Health Ireland, Dublin, Ireland
| | - Lawrence F Eichenfield
- Departments of Dermatology and Pediatrics, University of California San Diego School of Medicine, La Jolla, California
| | - Thomas Werfel
- Department of Dermatology and Allergy, Hannover Medical School, Hannover, Germany; Cluster of Excellence RESIST (EXC 2155), Hannover Medical School, Hannover, Germany
| | | | - Li Jiang
- LEO Pharma A/S, Ballerup, Denmark
| | | | - Amy S Paller
- Department of Dermatology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois
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9
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The dynamic balance of the skin microbiome across the lifespan. Biochem Soc Trans 2023; 51:71-86. [PMID: 36606709 PMCID: PMC9988004 DOI: 10.1042/bst20220216] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Revised: 12/02/2022] [Accepted: 12/05/2022] [Indexed: 01/07/2023]
Abstract
For decades research has centered on identifying the ideal balanced skin microbiome that prevents disease and on developing therapeutics to foster this balance. However, this single idealized balance may not exist. The skin microbiome changes across the lifespan. This is reflected in the dynamic shifts of the skin microbiome's diverse, inter-connected community of microorganisms with age. While there are core skin microbial taxa, the precise community composition for any individual person is determined by local skin physiology, genetics, microbe-host interactions, and microbe-microbe interactions. As a key interface with the environment, the skin surface and its appendages are also constantly exchanging microbes with close personal contacts and the environment. Hormone fluctuations and immune system maturation also drive age-dependent changes in skin physiology that support different microbial community structures over time. Here, we review recent insights into the factors that shape the skin microbiome throughout life. Collectively, the works summarized within this review highlight how, depending on where we are in lifespan, our skin supports robust microbial communities, while still maintaining microbial features unique to us. This review will also highlight how disruptions to this dynamic microbial balance can influence risk for dermatological diseases as well as impact lifelong health.
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10
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Maciag JJ, Chantraine C, Mills KB, Yadav R, Yarawsky AE, Chaton CT, Vinod D, Fitzkee NC, Mathelié-Guinlet M, Dufrêne YF, Fey PD, Horswill AR, Herr AB. Mechanistic basis of staphylococcal interspecies competition for skin colonization. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.01.26.525635. [PMID: 36747832 PMCID: PMC9900903 DOI: 10.1101/2023.01.26.525635] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Staphylococci, whether beneficial commensals or pathogens, often colonize human skin, potentially leading to competition for the same niche. In this multidisciplinary study we investigate the structure, binding specificity, and mechanism of adhesion of the Aap lectin domain required for Staphylococcus epidermidis skin colonization and compare its characteristics to the lectin domain from the orthologous Staphylococcus aureus adhesin SasG. The Aap structure reveals a legume lectin-like fold with atypical architecture, showing specificity for N-acetyllactosamine and sialyllactosamine. Bacterial adhesion assays using human corneocytes confirmed the biological relevance of these Aap-glycan interactions. Single-cell force spectroscopy experiments measured individual binding events between Aap and corneocytes, revealing an extraordinarily tight adhesion force of nearly 900 nN and a high density of receptors at the corneocyte surface. The SasG lectin domain shares similar structural features, glycan specificity, and corneocyte adhesion behavior. We observe cross-inhibition of Aap-and SasG-mediated staphylococcal adhesion to corneocytes. Together, these data provide insights into staphylococcal interspecies competition for skin colonization and suggest potential avenues for inhibition of S. aureus colonization.
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Affiliation(s)
- Joseph J. Maciag
- Division of Immunobiology, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH
| | - Constance Chantraine
- Louvain Institute of Biomolecular Science and Technology, UCLouvain, Louvain-la-Neuve, Belgium
| | - Krista B. Mills
- Department of Immunology and Microbiology, University of Colorado School of Medicine, Aurora, CO
| | - Rahul Yadav
- Department of Chemistry, Mississippi State University, Mississippi State, MS
| | - Alexander E. Yarawsky
- Division of Immunobiology, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH
| | - Catherine T. Chaton
- Division of Immunobiology, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH
| | - Divya Vinod
- Division of Immunobiology, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH
- Medical Sciences Undergraduate Program, University of Cincinnati, Cincinnati, OH
| | - Nicholas C. Fitzkee
- Department of Chemistry, Mississippi State University, Mississippi State, MS
| | - Marion Mathelié-Guinlet
- Institut de Chimie et Biologie des Membranes et des Nano-Objets, CNRS UMR 5248, University of Bordeaux, Pessac, France
| | - Yves F. Dufrêne
- Louvain Institute of Biomolecular Science and Technology, UCLouvain, Louvain-la-Neuve, Belgium
| | - Paul D. Fey
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, NE
| | - Alexander R. Horswill
- Department of Immunology and Microbiology, University of Colorado School of Medicine, Aurora, CO
| | - Andrew B. Herr
- Division of Immunobiology, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH
- Division of Infectious Diseases, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH
- Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH
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11
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Paiva T, Viljoen A, da Costa TM, Geoghegan JA, Dufrêne YF. Interaction of the Staphylococcus aureus Surface Protein FnBPB with Corneodesmosin Involves Two Distinct, Extremely Strong Bonds. ACS NANOSCIENCE AU 2022; 3:58-66. [PMID: 36820093 PMCID: PMC9936583 DOI: 10.1021/acsnanoscienceau.2c00036] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Revised: 09/30/2022] [Accepted: 09/30/2022] [Indexed: 02/17/2023]
Abstract
Attachment of Staphylococcus aureus to human skin corneocyte cells plays a critical role in exacerbating the severity of atopic dermatitis (AD). Pathogen-skin adhesion is mediated by bacterial cell-surface proteins called adhesins, including fibronectin-binding protein B (FnBPB). FnBPB binds to corneodesmosin (CDSN), a glycoprotein exposed on AD patient corneocytes. Using single-molecule experiments, we demonstrate that CDSN binding by FnBPB relies on a sophisticated two-site mechanism. Both sites form extremely strong bonds with binding forces of ∼1 and ∼2.5 nN albeit with faster dissociation rates than those reported for homologues of the adhesin. This previously unidentified two-binding site interaction in FnBPB illustrates its remarkable variety of adhesive functions and is of biological significance as the high strength and short bond lifetime will favor efficient skin colonization by the pathogen.
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Affiliation(s)
- Telmo
O. Paiva
- Louvain
Institute of Biomolecular Science and Technology, UCLouvain, Croix du Sud, 4-5, L7.07.07, B-1348 Louvain-la-Neuve, Belgium
| | - Albertus Viljoen
- Louvain
Institute of Biomolecular Science and Technology, UCLouvain, Croix du Sud, 4-5, L7.07.07, B-1348 Louvain-la-Neuve, Belgium
| | - Thaina M. da Costa
- Department
of Microbiology, Moyne Institute of Preventive Medicine, School of
Genetics and Microbiology, Trinity College
Dublin, Dublin 2, Ireland
| | - Joan A. Geoghegan
- Department
of Microbiology, Moyne Institute of Preventive Medicine, School of
Genetics and Microbiology, Trinity College
Dublin, Dublin 2, Ireland,Institute
of Microbiology and Infection, University
of Birmingham, Edgbaston, Birmingham B15 2TT, U.K.,
| | - Yves F. Dufrêne
- Louvain
Institute of Biomolecular Science and Technology, UCLouvain, Croix du Sud, 4-5, L7.07.07, B-1348 Louvain-la-Neuve, Belgium,
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12
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Skin Barrier Abnormalities in Atopic Dermatitis. CURRENT TREATMENT OPTIONS IN ALLERGY 2022. [DOI: 10.1007/s40521-022-00310-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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13
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Berry KA, Verhoef MTA, Leonard AC, Cox G. Staphylococcus aureus adhesion to the host. Ann N Y Acad Sci 2022; 1515:75-96. [PMID: 35705378 DOI: 10.1111/nyas.14807] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Staphylococcus aureus is a pathobiont capable of colonizing and infecting most tissues within the human body, resulting in a multitude of different clinical outcomes. Adhesion of S. aureus to the host is crucial for both host colonization and the establishment of infections. Underlying the pathogen's success is a complex and diverse arsenal of adhesins. In this review, we discuss the different classes of adhesins, including a consideration of the various adhesion sites throughout the body and the clinical outcomes of each infection type. The development of therapeutics targeting the S. aureus host-pathogen interaction is a relatively understudied area. Due to the increasing global threat of antimicrobial resistance, it is crucial that innovative and alternative approaches are considered. Neutralizing virulence factors, through the development of antivirulence agents, could reduce bacterial pathogenicity and the ever-increasing burden of S. aureus infections. This review provides insight into potentially efficacious adhesion-associated targets for the development of novel decolonizing and antivirulence strategies.
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Affiliation(s)
- Kirsten A Berry
- Department of Molecular and Cellular Biology, College of Biological Sciences, University of Guelph, Guelph, Ontario, Canada
| | - Mackenzie T A Verhoef
- Department of Molecular and Cellular Biology, College of Biological Sciences, University of Guelph, Guelph, Ontario, Canada
| | - Allison C Leonard
- Department of Molecular and Cellular Biology, College of Biological Sciences, University of Guelph, Guelph, Ontario, Canada
| | - Georgina Cox
- Department of Molecular and Cellular Biology, College of Biological Sciences, University of Guelph, Guelph, Ontario, Canada
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14
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Fölster-Holst R. Die Rolle des Hautmikrobioms bei atopischer Dermatitis - Zusammenhänge und Konsequenzen. J Dtsch Dermatol Ges 2022; 20:571-578. [PMID: 35578413 DOI: 10.1111/ddg.14709_g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Accepted: 11/29/2021] [Indexed: 11/29/2022]
Affiliation(s)
- Regina Fölster-Holst
- Dermatologie, Venerologie und Allergologie, Universitätsklinikum Schleswig-Holstein, Kiel
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15
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Moosbrugger-Martinz V, Leprince C, Méchin MC, Simon M, Blunder S, Gruber R, Dubrac S. Revisiting the Roles of Filaggrin in Atopic Dermatitis. Int J Mol Sci 2022; 23:5318. [PMID: 35628125 PMCID: PMC9140947 DOI: 10.3390/ijms23105318] [Citation(s) in RCA: 36] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2022] [Revised: 05/03/2022] [Accepted: 05/06/2022] [Indexed: 12/31/2022] Open
Abstract
The discovery in 2006 that loss-of-function mutations in the filaggrin gene (FLG) cause ichthyosis vulgaris and can predispose to atopic dermatitis (AD) galvanized the dermatology research community and shed new light on a skin protein that was first identified in 1981. However, although outstanding work has uncovered several key functions of filaggrin in epidermal homeostasis, a comprehensive understanding of how filaggrin deficiency contributes to AD is still incomplete, including details of the upstream factors that lead to the reduced amounts of filaggrin, regardless of genotype. In this review, we re-evaluate data focusing on the roles of filaggrin in the epidermis, as well as in AD. Filaggrin is important for alignment of keratin intermediate filaments, control of keratinocyte shape, and maintenance of epidermal texture via production of water-retaining molecules. Moreover, filaggrin deficiency leads to cellular abnormalities in keratinocytes and induces subtle epidermal barrier impairment that is sufficient enough to facilitate the ingress of certain exogenous molecules into the epidermis. However, although FLG null mutations regulate skin moisture in non-lesional AD skin, filaggrin deficiency per se does not lead to the neutralization of skin surface pH or to excessive transepidermal water loss in atopic skin. Separating facts from chaff regarding the functions of filaggrin in the epidermis is necessary for the design efficacious therapies to treat dry and atopic skin.
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Affiliation(s)
- Verena Moosbrugger-Martinz
- Department of Dermatology, Venereology and Allergology, Medical University of Innsbruck, Anichstraße 35, 6020 Innsbruck, Austria; (V.M.-M.); (S.B.); (R.G.)
| | - Corinne Leprince
- Toulouse Institute for Infectious and Inflammatory Diseases (Infinity), Toulouse University, CNRS UMR5051, Inserm UMR1291, UPS, 31059 Toulouse, France; (C.L.); (M.-C.M.); (M.S.)
| | - Marie-Claire Méchin
- Toulouse Institute for Infectious and Inflammatory Diseases (Infinity), Toulouse University, CNRS UMR5051, Inserm UMR1291, UPS, 31059 Toulouse, France; (C.L.); (M.-C.M.); (M.S.)
| | - Michel Simon
- Toulouse Institute for Infectious and Inflammatory Diseases (Infinity), Toulouse University, CNRS UMR5051, Inserm UMR1291, UPS, 31059 Toulouse, France; (C.L.); (M.-C.M.); (M.S.)
| | - Stefan Blunder
- Department of Dermatology, Venereology and Allergology, Medical University of Innsbruck, Anichstraße 35, 6020 Innsbruck, Austria; (V.M.-M.); (S.B.); (R.G.)
| | - Robert Gruber
- Department of Dermatology, Venereology and Allergology, Medical University of Innsbruck, Anichstraße 35, 6020 Innsbruck, Austria; (V.M.-M.); (S.B.); (R.G.)
| | - Sandrine Dubrac
- Department of Dermatology, Venereology and Allergology, Medical University of Innsbruck, Anichstraße 35, 6020 Innsbruck, Austria; (V.M.-M.); (S.B.); (R.G.)
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16
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Mechanisms and Implications of Bacterial Invasion across the Human Skin Barrier. Microbiol Spectr 2022; 10:e0274421. [PMID: 35532353 PMCID: PMC9241919 DOI: 10.1128/spectrum.02744-21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Atopic dermatitis (AD) is associated with a deficiency of skin lipids, increased populations of Staphylococcus aureus in the microbiome, and structural defects in the stratum corneum (SC), the outermost layer of human skin. However, the pathogenesis of AD is ambiguous, as it is unclear whether observed changes are the result of AD or contribute to the pathogenesis of the disease. Previous studies have shown that S. aureus is capable of permeating across isolated human SC tissue when lipids are depleted to levels consistent with AD conditions. In this study, we expand upon this discovery to determine the mechanisms and implications of bacterial penetration into the SC barrier. Specifically, we establish if bacteria are permeating intercellularly or employing a combination of both inter- and intracellular travel. The mechanical implications of bacterial invasion, lipid depletion, and media immersion are also evaluated using a newly developed, physiologically relevant, temperature-controlled drip chamber. Results reveal for the first time that S. aureus can be internalized by corneocytes, indicating transcellular movement through the tissue during permeation, consistent with previous theoretical models. S. aureus also degrades the mechanical integrity of human SC, particularly when the tissue is partially depleted of lipids. These observed mechanical changes are likely the cause of broken or ruptured tissue seen as exudative lesions in AD flares. This work further highlights the necessity of lipids in skin microbial barrier function. IMPORTANCE Millions of people suffer from the chronic inflammatory skin disease atopic dermatitis (AD), whose symptoms are associated with a deficiency of skin lipids that exhibit antimicrobial functions and increased populations of the opportunistic pathogen Staphylococcus aureus. However, the pathogenesis of AD is ambiguous, and it remains unclear if these observed changes are merely the result of AD or contribute to the pathogenesis of the disease. In this article, we demonstrate the necessity of skin lipids in preventing S. aureus from penetrating the outermost barrier of human skin, thereby causing a degradation in tissue integrity. This bacterial permeation into the viable epidermis could act as an inflammatory trigger of the disease. When coupled with delipidated AD tissue conditions, bacterial permeation can also explain increased tissue fragility, potentially causing lesion formation in AD patients that results in further enhancing bacterial permeability across the stratum corneum and the development of chronic conditions.
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17
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Fibronectin binding protein B binds to loricrin and promotes corneocyte adhesion by Staphylococcus aureus. Nat Commun 2022; 13:2517. [PMID: 35523796 PMCID: PMC9076634 DOI: 10.1038/s41467-022-30271-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Accepted: 04/19/2022] [Indexed: 12/23/2022] Open
Abstract
Colonisation of humans by Staphylococcus aureus is a major risk factor for infection, yet the bacterial and host factors involved are not fully understood. The first step during skin colonisation is adhesion of the bacteria to corneocytes in the stratum corneum where the cornified envelope protein loricrin is the main ligand for S. aureus. Here we report a novel loricrin-binding protein of S. aureus, the cell wall-anchored fibronectin binding protein B (FnBPB). Single-molecule force spectroscopy revealed both weak and ultra-strong (2 nN) binding of FnBPB to loricrin and that mechanical stress enhanced the strength of these bonds. Treatment with a peptide derived from fibrinogen decreased the frequency of strong interactions, suggesting that both ligands bind to overlapping sites within FnBPB. Finally, we show that FnBPB promotes adhesion to human corneocytes by binding strongly to loricrin, highlighting the relevance of this interaction to skin colonisation. The first step during skin colonization by is its adhesion to corneocytes. Da Costa et al. show that the cell wall-anchored fibronectin binding protein B (FnBPB) of S. aureus binds to loricrin. Applying single cell force spectroscopy, they demonstrate that this interaction promotes adhesion of S. aureus to human corneocytes.
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18
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Beck LA, Cork MJ, Amagai M, De Benedetto A, Kabashima K, Hamilton JD, Rossi AB. Type 2 Inflammation Contributes to Skin Barrier Dysfunction in Atopic Dermatitis. JID INNOVATIONS 2022; 2:100131. [PMID: 36059592 PMCID: PMC9428921 DOI: 10.1016/j.xjidi.2022.100131] [Citation(s) in RCA: 74] [Impact Index Per Article: 37.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Revised: 01/04/2022] [Accepted: 01/06/2022] [Indexed: 01/02/2023] Open
Abstract
Skin barrier dysfunction, a defining feature of atopic dermatitis (AD), arises from multiple interacting systems. In AD, skin inflammation is caused by host-environment interactions involving keratinocytes as well as tissue-resident immune cells such as type 2 innate lymphoid cells, basophils, mast cells, and T helper type 2 cells, which produce type 2 cytokines, including IL-4, IL-5, IL-13, and IL-31. Type 2 inflammation broadly impacts the expression of genes relevant for barrier function, such as intracellular structural proteins, extracellular lipids, and junctional proteins, and enhances Staphylococcus aureus skin colonization. Systemic anti‒type 2 inflammation therapies may improve dysfunctional skin barrier in AD.
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Key Words
- AD, atopic dermatitis
- AMP, antimicrobial peptide
- CLDN, claudin
- FFA, free fatty acid
- ILC2, type 2 innate lymphoid cell
- Jaki, Jak inhibitor
- K, keratin
- KC, keratinocyte
- MMP, matrix metalloproteinase
- NMF, natural moisturizing factor
- PAR, protease-activated receptor
- PDE-4, phosphodiesterase-4
- SC, stratum corneum
- SG, stratum granulosum
- TCI, topical calcineurin inhibitor
- TCS, topical corticosteroid
- TEWL, transepidermal water loss
- TJ, tight junction
- TLR, toll-like receptor
- TNF-α, tumor necrosis factor alpha
- TYK, tyrosine kinase
- Th, T helper
- ZO, zona occludens
- hBD, human β-defensin
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Affiliation(s)
- Lisa A. Beck
- Department of Dermatology, University of Rochester Medical Center, Rochester, New York, USA,Correspondence: Lisa A. Beck, Department of Dermatology, University of Rochester Medical Center, 601 Elmwood Ave, Box 697, Rochester, New York 14642, USA.
| | - Michael J. Cork
- Sheffield Dermatology Research, Department of Infection, Immunity and Cardiovascular Disease (IICD), The University of Sheffield, The Medical School, Sheffield, United Kingdom
| | - Masayuki Amagai
- Department of Dermatology, Keio University School of Medicine, Tokyo, Japan,Laboratory for Skin Homeostasis, RIKEN Center for Integrative Medical Sciences, Yokohama, Japan
| | - Anna De Benedetto
- Department of Dermatology, University of Rochester Medical Center, Rochester, New York, USA
| | - Kenji Kabashima
- Department of Dermatology, Kyoto University Graduate School of Medicine, Kyoto University, Kyoto, Japan
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19
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Fölster-Holst R. The role of the skin microbiome in atopic dermatitis - correlations and consequences. J Dtsch Dermatol Ges 2022; 20:571-577. [PMID: 35384293 DOI: 10.1111/ddg.14709] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Accepted: 11/29/2021] [Indexed: 12/26/2022]
Abstract
The physical barrier function of the skin is significantly supported by the (epi-)dermal immune system and the skin's own microbiome. Atopic dermatitis is characterized by an imbalance of all these three factors. The skin microbiome establishes itself immediately after birth and plays an important role in the development and maintenance of immune homeostasis. The clinical picture of atopic dermatitis shows, among other things, changes in the skin microbiome. Particularly during an acute phase, a strongly reduced bacterial diversity as well as the dominance of a single pathogen, Staphylococcus aureus, is observed. Staphylococcus aureus exacerbates the inflammatory process; furthermore, the bacteria produce proteases and toxins that further weaken the already severely compromised barrier function of the skin of patients with atopic dermatitis. However, knowledge of dermal dysbiosis also yields new treatment options for the therapy of the disease. In particular, the application of active bacteria represents a direct influence on the skin microbiome. Results of initial clinical studies on various approaches demonstrate promising results; this article provides an overview of work in this area.
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Affiliation(s)
- Regina Fölster-Holst
- Department of Dermatology, Venereology and Allergology, University Hospital Schleswig-Holstein, Kiel, Germany
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20
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Skin Microbiota in Atopic Dermatitis. Int J Mol Sci 2022; 23:ijms23073503. [PMID: 35408862 PMCID: PMC8998607 DOI: 10.3390/ijms23073503] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Revised: 03/18/2022] [Accepted: 03/22/2022] [Indexed: 12/26/2022] Open
Abstract
The skin microbiota represents an ecosystem composed of numerous microbial species interacting with each other, as well as with host epithelial and immune cells. The microbiota provides health benefits to the host by supporting essential functions of the skin and inhibiting colonization with pathogens. However, the disturbance of the microbial balance can result in dysbiosis and promote skin diseases, such as atopic dermatitis (AD). This review provides a current overview of the skin microbiota involvement in AD and its complex interplay with host immune response mechanisms, as well as novel therapeutic strategies for treating AD focused on restoring skin microbial homeostasis.
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21
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Kitagawa Y, Hayakawa K, Oikawa D, Ikeda K, Ikeda M, Harada D, Furuse M. Repeated restraint stress modifies fatty acid and amino acid metabolism in the mouse skin. J Vet Med Sci 2022; 84:511-519. [PMID: 35173101 PMCID: PMC9096037 DOI: 10.1292/jvms.21-0602] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
In modern society, stress caused by relationships and emotions is one of the greatest
social problems. Similar to humans, domestic and captive animals live under various
stresses. Several stresses have been associated with skin disorders, such as atopic
dermatitis, but there is a lack of reliable and objective indicators for the
characterization of this association. This study aimed to define the changes in fatty acid
composition and amino acid concentration in the skin following repeated restraint stress
in ICR mice. Mice subjected to 30 min of daily restraint stress for 8 days showed changes
in the composition of saturated fatty acids, such as an increase in palmitic acid content,
which are the substrates of Δ-9 desaturase. Conversely, unsaturated fatty acids decreased
with stress treatment, which appeared to be a result of these fatty acids being the
substrate of Δ-6 desaturase. Changes in fatty acid composition after stress treatment may
be one of the factors that cause skin inflammation. The water-retention capacity may have
been lowered by stress treatment because histidine and leucine, which are natural
moisturizing factors, were significantly decreased. The collagen content in the skin
gradually decreased after repeated stress treatment. Our results indicate that repeated
restraint stress may impact skin health through changes in both the fatty acid composition
and amino acid concentration in mice.
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Affiliation(s)
- Yume Kitagawa
- Laboratory of Regulation in Metabolism and Behavior, Faculty of Agriculture, Kyushu University
| | - Kaho Hayakawa
- Laboratory of Regulation in Metabolism and Behavior, Faculty of Agriculture, Kyushu University
| | | | - Kazuki Ikeda
- Laboratory of Regulation in Metabolism and Behavior, Faculty of Agriculture, Kyushu University
| | - Maki Ikeda
- Laboratory of Regulation in Metabolism and Behavior, Faculty of Agriculture, Kyushu University
| | - Daiki Harada
- Laboratory of Regulation in Metabolism and Behavior, Faculty of Agriculture, Kyushu University
| | - Mitsuhiro Furuse
- Laboratory of Regulation in Metabolism and Behavior, Faculty of Agriculture, Kyushu University
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22
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Abstract
The skin microbiome is a key component of pathogenesis in atopic dermatitis (AD). The skin of AD patients is characterized by microbial dysbiosis, with a reduction of microbial diversity and overrepresentation of pathogenic Staphylococcus aureus (S. aureus). Recent exciting studies have elucidated an importance of establishing an appropriate immune response to microbes in early life and uncovered the new mechanisms of microbial community dynamics in modulating our skin microbiome. Several microbes are associated with AD pathogenesis, with proposed pathogenic effects from S. aureus and Malassezia. The complex relationships between microbes within the skin microbiome consortia includes various species, such as Staphylococcal, Roseomonas and Cutibacterium strains, that can inhibit S. aureus and are potential probiotics for AD skin. Numerous microbes are now also reported to modulate host response via communication with keratinocytes, specialized immune cells and adipocytes to improve skin health and barrier function. This increased understanding of skin microbiota bioactives has led to new biotherapeutic approaches that target the skin surface microenvironment for AD treatment.
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23
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Yoshida T, Beck LA, De Benedetto A. Skin barrier defects in atopic dermatitis: From old idea to new opportunity. Allergol Int 2022; 71:3-13. [PMID: 34916117 PMCID: PMC8934597 DOI: 10.1016/j.alit.2021.11.006] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2021] [Accepted: 11/22/2021] [Indexed: 01/31/2023] Open
Abstract
Atopic dermatitis (AD) is the most common chronic skin inflammatory disease, with a profound impact on patients’ quality of life. AD varies considerably in clinical course, age of onset and degree to which it is accompanied by allergic and non-allergic comorbidities. Skin barrier impairment in both lesional and nonlesional skin is now recognized as a critical and often early feature of AD. This may be explained by a number of abnormalities identified within both the stratum corneum and stratum granulosum layers of the epidermis. The goal of this review is to provide an overview of key barrier defects in AD, starting with a historical perspective. We will also highlight some of the commonly used methods to characterize and quantify skin barrier function. There is ample opportunity for further investigative work which we call out throughout this review. These include: quantifying the relative impact of individual epidermal abnormalities and putting this in a more holistic view with physiological measures of barrier function, as well as determining whether these barrier-specific endotypes predict clinical phenotypes (e.g. age of onset, natural history, comorbidities, response to therapies, etc). Mechanistic studies with new (and in development) AD therapies that specifically target immune pathways, Staphylococcus aureus abundance and/or skin barrier will help us understand the dynamic crosstalk between these compartments and their relative importance in AD.
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24
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Baquero F, Saralegui C, Marcos-Mencía D, Ballestero L, Vañó-Galván S, Moreno-Arrones ÓM, Del Campo R. Epidermis as a Platform for Bacterial Transmission. Front Immunol 2021; 12:774018. [PMID: 34925344 PMCID: PMC8671829 DOI: 10.3389/fimmu.2021.774018] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Accepted: 11/03/2021] [Indexed: 11/13/2022] Open
Abstract
The epidermis constitutes a continuous external layer covering the body, offering protection against bacteria, the most abundant living organisms that come into contact with this barrier. The epidermis is heavily colonized by commensal bacterial organisms that help protect against pathogenic bacteria. The highly regulated and dynamic interaction between the epidermis and commensals involves the host’s production of nutritional factors promoting bacterial growth together to chemical and immunological bacterial inhibitors. Signal trafficking ensures the system’s homeostasis; conditions that favor colonization by pathogens frequently foster commensal growth, thereby increasing the bacterial population size and inducing the skin’s antibacterial response, eliminating the pathogens and re-establishing the normal density of commensals. The microecological conditions of the epidermis favors Gram-positive organisms and are unsuitable for long-term Gram-negative colonization. However, the epidermis acts as the most important host-to-host transmission platform for bacteria, including those that colonize human mucous membranes. Bacteria are frequently shared by relatives, partners, and coworkers. The epidermal bacterial transmission platform of healthcare workers and visitors can contaminate hospitalized patients, eventually contributing to cross-infections. Epidermal transmission occurs mostly via the hands and particularly through fingers. The three-dimensional physical structure of the epidermis, particularly the fingertips, which have frictional ridges, multiplies the possibilities for bacterial adhesion and release. Research into the biology of bacterial transmission via the hands is still in its infancy; however, tribology, the science of interacting surfaces in relative motion, including friction, wear and lubrication, will certainly be an important part of it. Experiments on finger-to-finger transmission of microorganisms have shown significant interindividual differences in the ability to transmit microorganisms, presumably due to genetics, age, sex, and the gland density, which determines the physical, chemical, adhesive, nutritional, and immunological status of the epidermal surface. These studies are needed to optimize interventions and strategies for preventing the hand transmission of microorganisms.
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Affiliation(s)
- Fernando Baquero
- Servicio de Microbiología, Hospital Universitario Ramón y Cajal and Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), Madrid, Spain.,Network Center for Research in Epidemiology and Public Health (CIBERESP), Madrid, Spain
| | - Claudia Saralegui
- Servicio de Microbiología, Hospital Universitario Ramón y Cajal and Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), Madrid, Spain
| | - Daniel Marcos-Mencía
- Servicio de Microbiología, Hospital Universitario Ramón y Cajal and Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), Madrid, Spain
| | - Luna Ballestero
- Servicio de Microbiología, Hospital Universitario Ramón y Cajal and Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), Madrid, Spain
| | - Sergio Vañó-Galván
- Servicio de Dermatología, Hospital Universitario Ramón y Cajal, and Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), Universidad de Alcalá, Madrid, Spain
| | - Óscar M Moreno-Arrones
- Servicio de Dermatología, Hospital Universitario Ramón y Cajal, and Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), Universidad de Alcalá, Madrid, Spain
| | - Rosa Del Campo
- Servicio de Microbiología, Hospital Universitario Ramón y Cajal and Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), Madrid, Spain.,Department of Health Sciences, Universidad Alfonso X El Sabio, Madrid, Spain.,Centro de Investigación en Red en Enfermedades Infecciosas (CIBER-EEII), Madrid, Spain
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25
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Howard B, Bascom CC, Hu P, Binder RL, Fadayel G, Huggins TG, Jarrold BB, Osborne R, Rocchetta HL, Swift D, Tiesman JP, Song Y, Wang Y, Wehmeyer K, Kimball AB, Isfort RJ. Aging Associated Changes in the Adult Human Skin Microbiome and the Host Factors That Affect Skin Microbiome Composition. J Invest Dermatol 2021; 142:1934-1946.e21. [PMID: 34890626 DOI: 10.1016/j.jid.2021.11.029] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Revised: 11/01/2021] [Accepted: 11/16/2021] [Indexed: 01/16/2023]
Abstract
Understanding changes in the skin microbiome and their relationship to host skin factors during aging remains largely unknown. To better understand this phenomenon, we collected samples for metagenomic and host skin factor analyses from forearm, buttock, and facial skin from 158 Caucasian females at 20-24, 30-34, 40-44, 50-54, 60-64, and 70-74 years of age. Metagenomics analysis was performed using 16S rRNA gene sequencing, while host sebocyte gland area, skin lipids, natural moisturizing factors (NMFs) and anti-microbial peptides (AMPs) measurements were also performed. These analyses demonstrated that skin bacterial diversity increased at all the skin sites with increasing age. Of the bacterial genera with average relative abundance of >1%, only Lactobacillus and Cutibacterium demonstrated a significant change (decrease) in abundance at all sampled skin sites with increasing age. Additional bacterial genera demonstrated significant age and site-specific changes in abundance. Analysis of sebocyte area, NMFs, lipids and AMPs demonstrated an age-related decrease in sebocyte area and increases in NMFs/AMPs/skin lipids, all which correlated with changes in specific bacterial genera. In conclusion, the human skin microbiome undergoes age-associated alterations that may reflect underlying age-related changes in cutaneous biology.
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Affiliation(s)
- Brian Howard
- The Procter & Gamble Company, Cincinnati, OH USA
| | | | - Ping Hu
- The Procter & Gamble Company, Cincinnati, OH USA
| | | | - Gina Fadayel
- The Procter & Gamble Company, Cincinnati, OH USA
| | | | | | | | | | - Dionne Swift
- The Procter & Gamble Company, Cincinnati, OH USA
| | | | - Yuli Song
- The Procter & Gamble Company, Cincinnati, OH USA
| | - Yu Wang
- The Procter & Gamble Company, Cincinnati, OH USA
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26
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Darlenski R, Kozyrskyj AL, Fluhr JW, Caraballo L. Association between barrier impairment and skin microbiota in atopic dermatitis from a global perspective: Unmet needs and open questions. J Allergy Clin Immunol 2021; 148:1387-1393. [PMID: 34688495 DOI: 10.1016/j.jaci.2021.10.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Revised: 10/06/2021] [Accepted: 10/08/2021] [Indexed: 12/17/2022]
Abstract
Atopic diathesis encompassing atopic dermatitis (AD), allergic rhinoconjunctivitis, food allergy, eosinophilic esophagitis, and asthma is a widely prevalent condition with a broad heterogeneity in clinical course, age of onset, and lifespan persistence. A primary event in AD is the commonly inherited epidermal barrier dysfunction. Together with the host-microbiome interactions, barrier defect and allergen exposure modulate both innate and adaptive immunity, thus triggering and maintaining the inflammatory response. Microbiome diversity, together with the host's contact with nonpathogenic microbes in childhood, is a prerequisite for functional maturation of the immune system, which is in part mediated by microbiome-induced epigenetic changes. Yet, whether microbiome alterations are the result or the reason for barrier impairment and inflammatory response of the host is unclear. Exposure to locally prevalent microbial species could contribute to further modification of the disease course. The objective of this review is to reveal the link between changes in the skin microbiota, barrier dysfunction, and inflammation in AD. Addressing unmet needs includes determining the genetic background of AD susceptibility; the epigenetic modifications induced by the microbiota and other environmental factors; the role of globally diverse provoking factors; and the implementation of personalized, phenotype-specific therapies such as a epidermal barrier restoration in infancy and microbiota modulation via systemic or topical interventions, all of which open gaps for future research.
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Affiliation(s)
- Razvigor Darlenski
- Department of Dermatovenerology, ACC Tokuda Hospital, Sofia, Bulgaria; Department of Dermatovenerology, Trakia University, Stara Zagora, Bulgaria.
| | - Anita L Kozyrskyj
- Department of Pediatrics, Faculty of Medicine and Dentistry, Edmonton Clinic Health Academy, Edmonton, Alberta, Canada
| | - Joachim W Fluhr
- Department of Dermatology, Venereology and Allergology, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Luis Caraballo
- Institute for Immunological Research, University of Cartagena, Cartagena, Colombia
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Blicharz L, Rudnicka L, Czuwara J, Waśkiel-Burnat A, Goldust M, Olszewska M, Samochocki Z. The Influence of Microbiome Dysbiosis and Bacterial Biofilms on Epidermal Barrier Function in Atopic Dermatitis-An Update. Int J Mol Sci 2021; 22:ijms22168403. [PMID: 34445108 PMCID: PMC8395079 DOI: 10.3390/ijms22168403] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Revised: 07/31/2021] [Accepted: 08/02/2021] [Indexed: 12/13/2022] Open
Abstract
Atopic dermatitis (AD) is a common inflammatory dermatosis affecting up to 30% of children and 10% of adults worldwide. AD is primarily driven by an epidermal barrier defect which triggers immune dysregulation within the skin. According to recent research such phenomena are closely related to the microbial dysbiosis of the skin. There is growing evidence that cutaneous microbiota and bacterial biofilms negatively affect skin barrier function, contributing to the onset and exacerbation of AD. This review summarizes the latest data on the mechanisms leading to microbiome dysbiosis and biofilm formation in AD, and the influence of these phenomena on skin barrier function.
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Affiliation(s)
- Leszek Blicharz
- Department of Dermatology, Medical University of Warsaw, 02-008 Warsaw, Poland; (L.R.); (J.C.); (A.W.-B.); (M.O.); (Z.S.)
- Correspondence:
| | - Lidia Rudnicka
- Department of Dermatology, Medical University of Warsaw, 02-008 Warsaw, Poland; (L.R.); (J.C.); (A.W.-B.); (M.O.); (Z.S.)
| | - Joanna Czuwara
- Department of Dermatology, Medical University of Warsaw, 02-008 Warsaw, Poland; (L.R.); (J.C.); (A.W.-B.); (M.O.); (Z.S.)
| | - Anna Waśkiel-Burnat
- Department of Dermatology, Medical University of Warsaw, 02-008 Warsaw, Poland; (L.R.); (J.C.); (A.W.-B.); (M.O.); (Z.S.)
| | - Mohamad Goldust
- Department of Dermatology, University Medical Center of the Johannes Gutenberg University, 55131 Mainz, Germany;
| | - Małgorzata Olszewska
- Department of Dermatology, Medical University of Warsaw, 02-008 Warsaw, Poland; (L.R.); (J.C.); (A.W.-B.); (M.O.); (Z.S.)
| | - Zbigniew Samochocki
- Department of Dermatology, Medical University of Warsaw, 02-008 Warsaw, Poland; (L.R.); (J.C.); (A.W.-B.); (M.O.); (Z.S.)
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Glycan-Dependent Corneocyte Adherence of Staphylococcus epidermidis Mediated by the Lectin Subdomain of Aap. mBio 2021; 12:e0290820. [PMID: 34253065 PMCID: PMC8406310 DOI: 10.1128/mbio.02908-20] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Staphylococcus epidermidis and other coagulase-negative staphylococci (CoNS) that colonize skin are known to promote skin immunity and inhibit colonization of pathogens that cause skin and soft tissue infections, including Staphylococcus aureus. However, S. epidermidis adherence to corneocytes, the cells that constitute the uppermost layer of the skin epidermis, remains poorly understood. Our study documents that S. epidermidis corneocyte adherence is dependent upon the accumulation-associated protein (Aap). Aap is composed of two distinct A and B domains. The A domain is comprised of a repeat region and a conserved L-type lectin domain, whereas the fibrillar B domain, which is comprised of G5 and E repeats, is linked to the cell wall in a sortase-dependent manner. Our studies revealed that adherence to corneocytes is dependent upon the lectin subdomain within the A domain. However, significant adherence was only observed when the lectin domain was expressed with both the A repeat and the B domain, suggesting further interactions between these three domains. Our data also suggest that the A repeat domain is important for stability or expression of Aap. Deglycosylation treatment suggested that glycans expressed in the host stratum corneum serve as potential binding partners for Aap-mediated corneocyte adherence. Last, bioinformatic analyses of the predominant commensal species of CoNS identified open reading frames (ORFs) homologous to aap, thus suggesting that Aap orthologues containing lectin-like domains may provide the basis for staphylococcal colonization of skin. Corroborating these observations, adherence to corneocytes in an S. aureus mgrA mutant was dependent upon SasG, the Aap orthologue in S. aureus. IMPORTANCE Staphylococcus aureus is the most significant cause of skin and soft tissue infections yet it rarely colonizes the skin of healthy individuals. This is believed to be due, in part, to inhibition of colonization via toxic substances produced by normal skin flora, including by S. epidermidis. Furthermore, we surmise that S. aureus colonization inhibition may also be due to competition for binding sites on host corneocytes. To understand these potential interactions between S. aureus and S. epidermidis and, potentially, other coagulase-negative staphylococci, we must first understand how staphylococci adhere to corneocytes. This work documents that S. epidermidis adherence to corneocytes is dependent upon the fibrillar cell wall-associated protein Aap. Our work further documents that Aap binds to glycans exposed on the corneocyte surface, which are commonly exploited by bacteria to facilitate adherence to host cells. Furthermore, we find that Aap orthologues may be responsible for corneocyte adherence in other staphylococci, including in S. aureus.
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van den Bogaard EH, Esser C, Perdew GH. The aryl hydrocarbon receptor at the forefront of host-microbe interactions in the skin: A perspective on current knowledge gaps and directions for future research and therapeutic applications. Exp Dermatol 2021; 30:1477-1483. [PMID: 34105853 PMCID: PMC8518783 DOI: 10.1111/exd.14409] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Revised: 05/11/2021] [Accepted: 05/22/2021] [Indexed: 02/06/2023]
Abstract
The skin is home to a community of skin microbiota including bacteria, viruses and fungi, which are widely accepted to be of importance for skin homeostasis but also associated with skin diseases. Detailed knowledge on the skin microbiota composition and its changes in a number of skin diseases is available. Yet, specific interactions between microbes and the host skin cells or how they communicate with each other are less well understood. To identify, understand and eventually therapeutically exploit causal relationships of microbial dysbiosis with disease, studies are required that address the receptors and mediators involved in host‐microbe interactions. In this perspective article, we provide an outlook on one of such receptors, namely the aryl hydrocarbon receptor (AHR). The AHR is well known for being a ligand‐activated transcription factor regulating the proliferation, differentiation and function of many cell types present in the skin. Its targeting by anti‐inflammatory therapeutics such as coal tar and Tapinarof is effective in atopic dermatitis and psoriasis. AHR signalling is activated upon binding of wide variety of small chemicals or ligands, including microbiota‐derived metabolites. New evidence has emerged pointing towards a key role for epidermal AHR signalling through skin microbiota‐derived metabolites. In response, AHR‐driven expression of antimicrobial peptides and stratum corneum formation may alter the skin microbiota composition. This a self‐perpetuating feedback loop calls for novel therapeutic intervention strategies for which we herein discuss the requirements in future mechanistic studies.
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Affiliation(s)
- Ellen H van den Bogaard
- Department of Dermatology, Radboud University Medical Center, Radboud Institute for Molecular Life Sciences, Nijmegen, The Netherlands
| | - Charlotte Esser
- IUF-Leibniz Research Institute for Environmental Medicine, Düsseldorf, Germany
| | - Gary H Perdew
- Department of Veterinary and Biomedical Sciences, Center for Molecular Toxicology and Carcinogenesis, The Pennsylvania State University, University Park, PA, USA
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Antibacterial Optimization of Highly Deformed Titanium Alloys for Spinal Implants. Molecules 2021; 26:molecules26113145. [PMID: 34074062 PMCID: PMC8197332 DOI: 10.3390/molecules26113145] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2021] [Revised: 05/19/2021] [Accepted: 05/20/2021] [Indexed: 12/31/2022] Open
Abstract
The goal of the work was to develop materials dedicated to spine surgery that minimized the potential for infection originating from the transfer of bacteria during long surgeries. The bacteria form biofilms, causing implant loosening, pain and finally, a risk of paralysis for patients. Our strategy focused both on improvement of antibacterial properties against bacteria adhesion and on wear and corrosion resistance of tools for spine surgery. Further, a ~35% decrease in implant and tool dimensions was expected by introducing ultrahigh-strength titanium alloys for less-invasive surgeries. The tested materials, in the form of thin, multi-layered coatings, showed nanocrystalline microstructures. Performed direct-cytotoxicity studies (including lactate dehydrogenase activity measurement) showed that there was a low probability of adverse effects on surrounding SAOS-2 (Homo sapiens bone osteosarcoma) cells. The microbiological studies (e.g., ISO 22196 contact tests) showed that implanting Ag nanoparticles into Ti/TixN coatings inhibited the growth of E. coli and S. aureus cells and reduced their adhesion to the material surface. These findings suggest that Ag-nanoparticles present in implant coatings may potentially minimize infection risk and lower inherent stress.
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Stefanovic N, Irvine AD, Flohr C. The Role of the Environment and Exposome in Atopic Dermatitis. CURRENT TREATMENT OPTIONS IN ALLERGY 2021; 8:222-241. [PMID: 34055570 PMCID: PMC8139547 DOI: 10.1007/s40521-021-00289-9] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/16/2021] [Indexed: 12/23/2022]
Abstract
PURPOSE OF REVIEW Atopic dermatitis (AD) is a chronic inflammatory skin disorder affecting up to 20% of children and up to 5% of adults worldwide, contributing to significant disease-related morbidity in this patient cohort. Its aetiopathogenesis is underpinned by multiple factors, including genetic susceptibility, skin barrier defects, a skewed cutaneous immune response and microbiome perturbation in both the skin and the gut. In this review, we aim to examine the biological effects of key environmental exposures (the sum of which is termed the "exposome") at the population, community and individual levels in order to describe their effect on AD pathogenesis. RECENT FINDINGS It is now understood that as well as considering the type of environmental exposure with regard to its effect on AD pathogenesis, the dosage and timing of the exposure are both critical domains that may lead to either exacerbation or amelioration of disease. In this review, we consider the effects of population-wide exposures such as climate change, migration and urbanization; community-specific exposures such as air pollution, water hardness and allergic sensitisation; and individual factors such as diet, microbiome alteration, psychosocial stress and the impact of topical and systemic therapy. SUMMARY This review summarises the interaction of the above environmental factors with the other domains of AD pathogenesis, namely, the inherent genetic defects, the skin barrier, the immune system and the cutaneous and gut microbiota. We specifically emphasise the timing and dosage of exposures and its effect on the cellular and molecular pathways implicated in AD.
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Affiliation(s)
| | - Alan D. Irvine
- Department of Paediatric Dermatology, Children’s Health Ireland at Crumlin, Dublin, Ireland
- National Children’s Research Centre, Crumlin and Clinical Medicine, Trinity College Dublin, Dublin, Ireland
| | - Carsten Flohr
- Unit for Population-Based Dermatology Research, St John’s Institute of Dermatology, Guy’s & St Thomas’ NHS Foundation Trust and King’s College London, London, UK
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32
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Évora AS, Adams MJ, Johnson SA, Zhang Z. Corneocytes: Relationship between Structural and Biomechanical Properties. Skin Pharmacol Physiol 2021; 34:146-161. [PMID: 33780956 DOI: 10.1159/000513054] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Accepted: 11/13/2020] [Indexed: 11/19/2022]
Abstract
BACKGROUND Skin is the interface between an organism and the external environment, and hence the stratum corneum (SC) is the first to withstand mechanical insults that, in certain conditions, may lead to integrity loss and the development of pressure ulcers. The SC comprises corneocytes, which are vital elements to its barrier function. These cells are differentiated dead keratinocytes, without organelles, composed of a cornified envelope and a keratin-filled interior, and connected by corneodesmosomes (CDs). SUMMARY The current review focusses on the relationship between the morphological, structural, and topographical features of corneocytes and their mechanical properties, to understand how they assist the SC in maintaining skin integrity and in responding to mechanical insults. Key Messages: Corneocytes create distinct regions in the SC: the inner SC is characterized by immature cells with a fragile cornified envelope and a uniform distribution of CDs; the upper SC has resilient cornified envelopes and a honeycomb distribution of CDs, with a greater surface area and a smaller thickness than cells from the inner layer. The literature indicates that this upward maturation process is one of the most important steps in the mechanical resistance and barrier function of the SC. The morphology of these cells is dependent on the body site: the surface area in non-exposed skin is about 1,000-1,200 μm2, while for exposed skin, for example, the cheek and forehead, is about 700-800 μm2. Corneocytes are stiff cells compared to other cellular types, for example, the Young's modulus of muscle and fibroblast cells is typically a few kPa, while that of corneocytes is reported to be about hundreds of MPa. Moreover, these skin cells have 2 distinct mechanical regions: the cornified envelope (100-250 MPa) and the keratin matrix (250-500 MPa).
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Affiliation(s)
- Ana S Évora
- School of Chemical Engineering, University of Birmingham, Birmingham, United Kingdom
| | - Michael J Adams
- School of Chemical Engineering, University of Birmingham, Birmingham, United Kingdom
| | - Simon A Johnson
- School of Chemical Engineering, University of Birmingham, Birmingham, United Kingdom
| | - Zhibing Zhang
- School of Chemical Engineering, University of Birmingham, Birmingham, United Kingdom
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Hu C, Duijts L, van Meel ER, Looman KIM, Kiefte-de Jong JC, Pardo LM, Hijnen D, Pasmans SGMA, de Jongste JC, Moll HA, Nijsten T. Association between nasal and nasopharyngeal bacterial colonization in early life and eczema phenotypes. Clin Exp Allergy 2021; 51:716-725. [PMID: 33759242 PMCID: PMC8252109 DOI: 10.1111/cea.13869] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2020] [Revised: 02/26/2021] [Accepted: 03/01/2021] [Indexed: 11/28/2022]
Abstract
Background An association has been reported between early life Staphylococcus aureus nasal carriage and higher risk of childhood eczema, but it is unclear whether this relationship is causal and associations with other bacterial species are unclear. Objective To examine the associations of early life nasal and nasopharyngeal bacterial carriage with eczema phenotypes, and the direction of any associations identified. Methods Among 996 subjects of a population‐based prospective cohort study, nasal swabs for Staphylococcus aureus, and nasopharyngeal swabs for Streptococcus pneumoniae, Moraxella catarrhalis and Haemophilus influenzae were collected and cultured from age 6 weeks to 6 years. Never, early, mid‐, late transient and persistent eczema phenotypes were identified from parental‐reported physician‐diagnosed eczema from age 6 months until 10 years. Multinomial regression models and cross‐lagged models were applied. Results Staphylococcus aureus nasal carriage at 6 months was associated with an increased risk of early transient and persistent eczema (OR (95% CI): 2.69 (1.34, 5.39) and 4.17 (1.12, 15.51)). The associations between Staphylococcus aureus nasal carriage and eczema were mostly cross‐sectional, and not longitudinal. No associations of Staphylococcus pneumoniae, Moraxella catarrhalis and Haemophilus influenza nasopharyngeal bacterial carriage with eczema and eczema phenotypes were observed (OR range (95% CI): 0.71 (0.35, 1.44) to 1.77 (0.84, 3.73)). Conclusions Early life Staphylococcus aureus nasal carriage, but not Staphylococcus pneumoniae, Moraxella catarrhalis and Haemophilus influenza nasopharyngeal carriage, was associated with early transient and persistent eczema. Staphylococcus aureus nasal carriage and eczema were mostly cross‐sectionally associated, and not longitudinally, making a causal relationship in either direction unlikely.
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Affiliation(s)
- Chen Hu
- The Generation R Study Group, University Medical Center Rotterdam, Erasmus MC, Rotterdam, The Netherlands.,Department of Dermatology, University Medical Center Rotterdam, Erasmus MC, Rotterdam, The Netherlands
| | - Liesbeth Duijts
- Division of Respiratory Medicine and Allergology, Department of Pediatrics, University Medical Center Rotterdam, Erasmus MC, Rotterdam, The Netherlands.,Division of Neonatology, Department of Pediatrics, University Medical Center Rotterdam, Erasmus MC, Rotterdam, The Netherlands
| | - Evelien R van Meel
- The Generation R Study Group, University Medical Center Rotterdam, Erasmus MC, Rotterdam, The Netherlands.,Division of Respiratory Medicine and Allergology, Department of Pediatrics, University Medical Center Rotterdam, Erasmus MC, Rotterdam, The Netherlands
| | - Kirsten I M Looman
- The Generation R Study Group, University Medical Center Rotterdam, Erasmus MC, Rotterdam, The Netherlands.,Department of Pediatrics, University Medical Center Rotterdam, Erasmus MC, Rotterdam, The Netherlands
| | - Jessica C Kiefte-de Jong
- Department of Epidemiology, University Medical Center Rotterdam, Erasmus MC, Rotterdam, The Netherlands.,Department of Public Health and Primary Care, Leiden University Medical Center, Leiden, The Netherlands
| | - Luba M Pardo
- Department of Dermatology, University Medical Center Rotterdam, Erasmus MC, Rotterdam, The Netherlands
| | - DirkJan Hijnen
- Department of Dermatology, University Medical Center Rotterdam, Erasmus MC, Rotterdam, The Netherlands
| | - Suzanne G M A Pasmans
- Department of Dermatology, University Medical Center Rotterdam, Erasmus MC, Rotterdam, The Netherlands
| | - Johan C de Jongste
- Division of Respiratory Medicine and Allergology, Department of Pediatrics, University Medical Center Rotterdam, Erasmus MC, Rotterdam, The Netherlands
| | - Henriette A Moll
- Department of Pediatrics, University Medical Center Rotterdam, Erasmus MC, Rotterdam, The Netherlands
| | - Tamar Nijsten
- Department of Dermatology, University Medical Center Rotterdam, Erasmus MC, Rotterdam, The Netherlands
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An SQ, Lopes BS, Connolly JPR, Sharp C, Nguyen TKL, Kirkpatrick CL. Going virtual: a report from the sixth Young Microbiologists Symposium on 'Microbe Signalling, Organisation and Pathogenesis'. MICROBIOLOGY (READING, ENGLAND) 2021; 167. [PMID: 33529149 DOI: 10.1099/mic.0.001024] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The sixth Young Microbiologists Symposium on 'Microbe Signalling, Organisation and Pathogenesis' was scheduled to be held at the University of Southampton, UK, in late August 2020. However, due to the health and safety guidelines and travel restrictions as a response to the COVID-19 pandemic, the symposium was transitioned to a virtual format, a change embraced enthusiastically as the meeting attracted over 200 microbiologists from 40 countries. The event allowed junior scientists to present their work to a broad audience and was supported by the European Molecular Biology Organization, the Federation of European Microbiological Societies, the Society of Applied Microbiology, the Biochemical Society, the Microbiology Society and the National Biofilms Innovation Centre. Sessions covered recent advances in all areas of microbiology including: Secretion and transport across membranes, Gene regulation and signalling, Host-microbe interactions, and Microbial communities and biofilm formation. This report focuses on several of the highlights and exciting developments communicated during the talks and poster presentations.
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Affiliation(s)
- Shi-Qi An
- School of Biological Sciences, National Biofilms Innovation Centre, University of Southampton, Southampton, UK
| | | | | | - Connor Sharp
- Department of Biochemistry, University of Oxford, Oxford, UK
- Department of Zoology, University of Oxford, Oxford, UK
| | | | - Clare Louise Kirkpatrick
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Odense, Denmark
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Abstract
Skin barrier dysfunction caused by endogenous or exogenous factors can lead to various disorders such as xerosis cutis, ichthyoses, and atopic dermatitis. Filaggrin is a pivotal structural protein of the stratum corneum (SC) and provides natural moisturizing factors that play a role in skin barrier functions. Filaggrin aggregates keratin filaments, resulting in the formation of a keratin network, which binds cornified envelopes and collapse keratinocytes to flattened corneocytes. This complex network contributes to the physical strength of the skin. Filaggrin is degraded by caspase-14, calpain 1, and bleomycin hydrolases into amino acids and amino acid metabolites such as trans-urocanic acid and pyrrolidone carboxylic acid, which are pivotal natural moisturizing factors in the SC. Accordingly, filaggrin is important for the pathophysiology of skin barrier disorders, and its deficiency or dysfunction leads to a variety of skin disorders. Here, the roles and biology of filaggrin, related skin diseases, and a therapeutic strategy targeting filaggrin are reviewed. In addition, several drug candidates of different mode of actions targeting filaggrin, along with their clinical efficacy, are discussed.
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Towell AM, Feuillie C, Vitry P, Da Costa TM, Mathelié-Guinlet M, Kezic S, Fleury OM, McAleer MA, Dufrêne YF, Irvine AD, Geoghegan JA. Staphylococcus aureus binds to the N-terminal region of corneodesmosin to adhere to the stratum corneum in atopic dermatitis. Proc Natl Acad Sci U S A 2021; 118:e2014444118. [PMID: 33361150 PMCID: PMC7817190 DOI: 10.1073/pnas.2014444118] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Staphylococcus aureus colonizes the skin of the majority of patients with atopic dermatitis (AD), and its presence increases disease severity. Adhesion of S. aureus to corneocytes in the stratum corneum is a key initial event in colonization, but the bacterial and host factors contributing to this process have not been defined. Here, we show that S. aureus interacts with the host protein corneodesmosin. Corneodesmosin is aberrantly displayed on the tips of villus-like projections that occur on the surface of AD corneocytes as a result of low levels of skin humectants known as natural moisturizing factor (NMF). An S. aureus mutant deficient in fibronectin binding protein B (FnBPB) and clumping factor B (ClfB) did not bind to corneodesmosin in vitro. Using surface plasmon resonance, we found that FnBPB and ClfB proteins bound with similar affinities. The S. aureus binding site was localized to the N-terminal glycine-serine-rich region of corneodesmosin. Atomic force microscopy showed that the N-terminal region was present on corneocytes containing low levels of NMF and that blocking it with an antibody inhibited binding of individual S. aureus cells to corneocytes. Finally, we found that S. aureus mutants deficient in FnBPB or ClfB have a reduced ability to adhere to low-NMF corneocytes from patients. In summary, we show that FnBPB and ClfB interact with the accessible N-terminal region of corneodesmosin on AD corneocytes, allowing S. aureus to take advantage of the aberrant display of corneodesmosin that accompanies low NMF in AD. This interaction facilitates the characteristic strong binding of S. aureus to AD corneocytes.
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Affiliation(s)
- Aisling M Towell
- Department of Microbiology, Moyne Institute of Preventive Medicine, School of Genetics and Microbiology, Trinity College Dublin, Dublin 2, Ireland
| | - Cécile Feuillie
- Louvain Institute of Biomolecular Science and Technology, Université Catholique de Louvain, B-1348 Louvain-la-Neuve, Belgium
| | - Pauline Vitry
- Louvain Institute of Biomolecular Science and Technology, Université Catholique de Louvain, B-1348 Louvain-la-Neuve, Belgium
| | - Thaina M Da Costa
- Department of Microbiology, Moyne Institute of Preventive Medicine, School of Genetics and Microbiology, Trinity College Dublin, Dublin 2, Ireland
| | - Marion Mathelié-Guinlet
- Louvain Institute of Biomolecular Science and Technology, Université Catholique de Louvain, B-1348 Louvain-la-Neuve, Belgium
| | - Sanja Kezic
- Coronel Institute of Occupational Health, Amsterdam Public Health Research Institute, University Medical Center, University of Amsterdam, 1105 AZ Amsterdam, The Netherlands
| | - Orla M Fleury
- Department of Microbiology, Moyne Institute of Preventive Medicine, School of Genetics and Microbiology, Trinity College Dublin, Dublin 2, Ireland
| | - Maeve A McAleer
- Clinical Medicine, Trinity College Dublin, Dublin 2, Ireland
| | - Yves F Dufrêne
- Louvain Institute of Biomolecular Science and Technology, Université Catholique de Louvain, B-1348 Louvain-la-Neuve, Belgium
- Walloon Excellence in Life Sciences and Biotechnology, B-1300 Wavre, Belgium
| | - Alan D Irvine
- Clinical Medicine, Trinity College Dublin, Dublin 2, Ireland
| | - Joan A Geoghegan
- Department of Microbiology, Moyne Institute of Preventive Medicine, School of Genetics and Microbiology, Trinity College Dublin, Dublin 2, Ireland;
- Institute of Microbiology and Infection, College of Medical and Dental Sciences, University of Birmingham, B15 2TT Birmingham, United Kingdom
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Beaussart A, Feuillie C, El-Kirat-Chatel S. The microbial adhesive arsenal deciphered by atomic force microscopy. NANOSCALE 2020; 12:23885-23896. [PMID: 33289756 DOI: 10.1039/d0nr07492f] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Microbes employ a variety of strategies to adhere to abiotic and biotic surfaces, as well as host cells. In addition to their surface physicochemical properties (e.g. charge, hydrophobic balance), microbes produce appendages (e.g. pili, fimbriae, flagella) and express adhesion proteins embedded in the cell wall or cell membrane, with adhesive domains targeting specific ligands or chemical properties. Atomic force microscopy (AFM) is perfectly suited to deciphering the adhesive properties of microbial cells. Notably, AFM imaging has revealed the cell wall topographical organization of live cells at unprecedented resolution, and AFM has a dual capability to probe adhesion at the single-cell and single-molecule levels. AFM is thus a powerful tool for unravelling the molecular mechanisms of microbial adhesion at scales ranging from individual molecular interactions to the behaviours of entire cells. In this review, we cover some of the major breakthroughs facilitated by AFM in deciphering the microbial adhesive arsenal, including the exciting development of anti-adhesive strategies.
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Blicharz L, Michalak M, Szymanek-Majchrzak K, Młynarczyk G, Skowroński K, Rudnicka L, Samochocki Z. The Propensity to Form Biofilm in vitro by Staphylococcus aureus Strains Isolated from the Anterior Nares of Patients with Atopic Dermatitis: Clinical Associations. Dermatology 2020; 237:528-534. [PMID: 33113538 DOI: 10.1159/000511182] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2020] [Accepted: 08/26/2020] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Atopic dermatitis is a chronic inflammatory dermatosis with complex pathogenesis. The skin microbiome in atopic dermatitis is dominated by Staphylococcus aureus which shows the ability to produce biofilm. OBJECTIVES The aim of this work was to assess the influence of S. aureus biofilm on the course of atopic dermatitis. METHODS Disease severity was evaluated based on the SCORAD index in 56 adult patients with atopic dermatitis. Microtiter plate assay of the propensity to form biofilm was performed on S. aureus strains isolated from the anterior nares, lesional skin, and nonlesional skin. Microbiological results were correlated to the clinical parameters and total IgE concentration. RESULTS Biofilm-producing strains of S. aureus were identified in 76.3% (29/38) and 79.1% (34/43) of samples from the anterior nares and lesional skin, respectively (p > 0.05), and in 48.5% (16/33) of samples from nonlesional skin (p < 0.03). Patients colonized by biofilm-producing strains of S. aureus within the anterior nares showed statistically higher mean values of total and objective SCORAD and its components (extent, dryness), and of the largest extent of skin lesions during the flares in the last year when compared to patients colonized by non-biofilm-producing strains. Carriage of biofilm-producing S. aureus on lesional skin was associated with higher mean values of the extent of skin lesions during stable periods of the disease. CONCLUSIONS The results of this study may suggest a relationship between the production of biofilm by S. aureus strains colonizing the anterior nares and the course of atopic dermatitis. Biofilm seems crucial for dispersal and persistent colonization of large areas of the skin by this pathogen. Destruction of S. aureus biofilm could positively affect the course of atopic dermatitis.
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Affiliation(s)
- Leszek Blicharz
- Department of Dermatology, Medical University of Warsaw, Warsaw, Poland
| | - Maryla Michalak
- Department of Medical Microbiology, Medical University of Warsaw, Warsaw, Poland
| | | | - Grażyna Młynarczyk
- Department of Medical Microbiology, Medical University of Warsaw, Warsaw, Poland
| | | | - Lidia Rudnicka
- Department of Dermatology, Medical University of Warsaw, Warsaw, Poland,
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Schulz A, Jiang L, de Vor L, Ehrström M, Wermeling F, Eidsmo L, Melican K. Neutrophil Recruitment to Noninvasive MRSA at the Stratum Corneum of Human Skin Mediates Transient Colonization. Cell Rep 2020; 29:1074-1081.e5. [PMID: 31665625 DOI: 10.1016/j.celrep.2019.09.055] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2019] [Revised: 08/16/2019] [Accepted: 09/18/2019] [Indexed: 11/16/2022] Open
Abstract
Staphylococcus aureus is a leading cause of skin and soft issue infection, but paradoxically, it also transiently, and often harmlessly, colonizes human skin. An obstacle to understanding this contradiction has been a shortage of in vivo models reproducing the unique structure and immunology of human skin. In this work, we developed a humanized model to study how healthy adult human skin responds to colonizing methicillin-resistant S. aureus (MRSA). We demonstrate the importance of the outer stratum corneum as the major site of bacterial colonization and how noninvasive MRSA adhesion to corneocytes induces a local inflammatory response in underlying skin layers. This signaling recruits neutrophils to the skin, where they control bacterial numbers, mediating transiency in colonization. This work highlights the spatiotemporal aspects of human skin colonization and demonstrates a subclinical inflammatory response to noninvasive MRSA that allows human skin to regulate the bacterial population at its outer surface.
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Affiliation(s)
- Anette Schulz
- Swedish Medical Nanoscience Center, Department of Neuroscience, Karolinska Institute, Stockholm 171 77, Sweden
| | - Long Jiang
- Division of Rheumatology, Department of Medicine Solna, Karolinska Institutet and Karolinska University Hospital, Stockholm 171 77, Sweden
| | - Lisanne de Vor
- Swedish Medical Nanoscience Center, Department of Neuroscience, Karolinska Institute, Stockholm 171 77, Sweden
| | - Marcus Ehrström
- Department of Reconstructive Plastic Surgery, Karolinska University Hospital Solna, Stockholm 171 77, Sweden
| | - Fredrik Wermeling
- Division of Rheumatology, Department of Medicine Solna, Karolinska Institutet and Karolinska University Hospital, Stockholm 171 77, Sweden
| | - Liv Eidsmo
- Division of Rheumatology, Department of Medicine Solna, Karolinska Institutet and Karolinska University Hospital, Stockholm 171 77, Sweden
| | - Keira Melican
- Swedish Medical Nanoscience Center, Department of Neuroscience, Karolinska Institute, Stockholm 171 77, Sweden.
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Ederveen THA, Smits JPH, Boekhorst J, Schalkwijk J, van den Bogaard EH, Zeeuwen PLJM. Skin microbiota in health and disease: From sequencing to biology. J Dermatol 2020; 47:1110-1118. [PMID: 32804417 PMCID: PMC7589227 DOI: 10.1111/1346-8138.15536] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2020] [Accepted: 07/06/2020] [Indexed: 01/24/2023]
Abstract
Microbiota live in a closely regulated interaction with their environment, and vice versa. The presence and absence of microbial entities is greatly influenced by features of the niche in which they thrive. Characteristic of this phenomenon is that different human skin sites harbor niche‐specific communities of microbes. Microbial diversity is considerable, and the current challenge lies in determining which microbes and (corresponding) functionality are of importance to a given ecological niche. Furthermore, as there is increasing evidence of microbial involvement in health and disease, the need arises to fundamentally understand microbiome processes for application in health care, nutrition and personal care products (e.g. diet, cosmetics, probiotics). This review provides a current overview of state‐of‐the‐art sequencing‐based techniques and corresponding data analysis methodology for profiling of complex microbial communities. Furthermore, we also summarize the existing knowledge regarding cutaneous microbiota and their human host for a wide range of skin diseases.
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Affiliation(s)
- Thomas H A Ederveen
- Center for Molecular and Biomolecular Informatics (CMBI), Radboud Institute for Molecular Life Sciences (RIMLS), Radboud University Medical Center (Radboudumc), Nijmegen, The Netherlands.,Department of Dermatology, RIMLS, Radboudumc, Nijmegen, The Netherlands
| | - Jos P H Smits
- Department of Dermatology, RIMLS, Radboudumc, Nijmegen, The Netherlands
| | - Jos Boekhorst
- Center for Molecular and Biomolecular Informatics (CMBI), Radboud Institute for Molecular Life Sciences (RIMLS), Radboud University Medical Center (Radboudumc), Nijmegen, The Netherlands.,NIZO, Ede, The Netherlands
| | - Joost Schalkwijk
- Department of Dermatology, RIMLS, Radboudumc, Nijmegen, The Netherlands
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Dufrêne YF, Viljoen A. Binding Strength of Gram-Positive Bacterial Adhesins. Front Microbiol 2020; 11:1457. [PMID: 32670256 PMCID: PMC7330015 DOI: 10.3389/fmicb.2020.01457] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Accepted: 06/04/2020] [Indexed: 11/13/2022] Open
Abstract
Bacterial pathogens are equipped with specialized surface-exposed proteins that bind strongly to ligands on host tissues and biomaterials. These adhesins play critical roles during infection, especially during the early step of adhesion where the cells are exposed to physical stress. Recent single-molecule experiments have shown that staphylococci interact with their ligands through a wide diversity of mechanosensitive molecular mechanisms. Adhesin-ligand interactions are activated by tensile force and can be ten times stronger than classical non-covalent biological bonds. Overall these studies demonstrate that Gram-positive adhesins feature unusual stress-dependent molecular interactions, which play essential roles during bacterial colonization and dissemination. With an increasing prevalence of multidrug resistant infections caused by Staphylococcus aureus and Staphylococcus epidermidis, chemotherapeutic targeting of adhesins offers an innovative alternative to antibiotics.
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Affiliation(s)
- Yves F Dufrêne
- Louvain Institute of Biomolecular Science and Technology, Catholic University of Louvain, Louvain-la-Neuve, Belgium
| | - Albertus Viljoen
- Louvain Institute of Biomolecular Science and Technology, Catholic University of Louvain, Louvain-la-Neuve, Belgium
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42
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Rawlings A. Microbes: Fighting for space on a fragile interface. Int J Cosmet Sci 2020; 42:310-312. [DOI: 10.1111/ics.12616] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2020] [Accepted: 03/17/2020] [Indexed: 11/27/2022]
Affiliation(s)
- A.V. Rawlings
- Director AVR Consulting Limited 26 Shavington Way Northwich Cheshire CW98FHUnited Kingdom
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Abstract
Microbial adhesion and biofilm formation are usually studied using molecular and cellular biology assays, optical and electron microscopy, or laminar flow chamber experiments. Today, atomic force microscopy (AFM) represents a valuable addition to these approaches, enabling the measurement of forces involved in microbial adhesion at the single-molecule level. In this minireview, we discuss recent discoveries made applying state-of-the-art AFM techniques to microbial specimens in order to understand the strength and dynamics of adhesive interactions. These studies shed new light on the molecular mechanisms of adhesion and demonstrate an intimate relationship between force and function in microbial adhesins.
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Ponnuvel S, Sankar S, Ponnuraj K. Analyzing the adhesion mechanism of FnBPA, a surface adhesin from Staphylococcus aureus on its interaction with nanoparticle. Microb Pathog 2020; 146:104239. [PMID: 32376360 DOI: 10.1016/j.micpath.2020.104239] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2019] [Revised: 04/24/2020] [Accepted: 04/27/2020] [Indexed: 12/17/2022]
Abstract
Staphylococcus aureus expresses many Microbial Surface Recognizing Adhesive Matrix Molecules (MSCRAMM's) to recognize host extracellular matrix (ECM) molecules to initiate colonization. The MSCRAMM, fibronectin binding protein A (FnBPA), is an important adhesin for S. aureus infection. FnBPA also binds with fibrinogen (Fg) by using a unique ligand binding mechanism called dock, lock and latch. Nanoparticles, especially nanosilver particles have been widely used in a variety of biomedical applications which includes disease diagnosis and treatment, drug delivery and implanted medical device coating. In a biological system, when protein molecules encounter nanoparticle, they can be absorbed onto its surface which results in the formation of protein corona. In the present study, we have analysed the fibrinogen binding ability of rFnBPA(189-512) in the presence of silver nanoparticles by employing techniques like gel shift assay, Western blot, size exclusion chromatography, enzyme-linked immunosorbent assay, bio-layer interferometry and circular dichroism spectroscopy. The results indicate that rFnBPA(189-512) is unable to bind to Fg in the presence of a nanoparticle. This could be due to the inaccessibility of the Fg binding site and conformational change in rFnBPA(189-512). With nanoparticles, rFnBPA(189-512) undergoes significant structural changes as the β-sheet content has drastically reduced to 10% from the initial 60% at higher concentration of the nanoparticle. Pathogenic bacteria interact with its surrounding environment through their surface molecules which includes MSCRAMMs. Therefore MSCRAMMs play an important role when bacteria encounter nanoparticles. The results of the present study suggest that the orientation of the protein during the absorption on the surface of a nanoparticle as well as the concentration of the nanoparticle, will dictate the function of the absorbed protein and in this case the Fg binding property of rFnBPA(189-512).
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Affiliation(s)
- Shobana Ponnuvel
- Centre of Advanced Study in Crystallography and Biophysics, University of Madras, Guindy Campus, Chennai, 600 025, India
| | - Sreejanani Sankar
- Centre of Advanced Study in Crystallography and Biophysics, University of Madras, Guindy Campus, Chennai, 600 025, India
| | - Karthe Ponnuraj
- Centre of Advanced Study in Crystallography and Biophysics, University of Madras, Guindy Campus, Chennai, 600 025, India.
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Abstract
: The role of Staphylococcus aureus (SA) in the pathogenesis and management in atopic dermatitis is rapidly evolving. The modern understanding of SA in atopic dermatitis now includes an expanded array of virulence factors, the interplay of clonal and temporal shifts in SA populations, and host factors such as filaggrin and natural moisturizing factor. New, emerging therapies that focus on long-term, targeted elimination of SA colonization are currently under investigation (Br J Dermatol 2017;17(1)63-71). Herein, we discuss and review the latest staphylococcal and microbiome-modifying therapies including topical antibiotics, topical natural oil fatty acids, anti-SA vaccines, microbial transplantation, vitamin D supplementation, dupilumab and proposed future investigative directions.
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Stefanovic N, Flohr C, Irvine AD. The exposome in atopic dermatitis. Allergy 2020; 75:63-74. [PMID: 31194890 PMCID: PMC7003958 DOI: 10.1111/all.13946] [Citation(s) in RCA: 93] [Impact Index Per Article: 23.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2019] [Revised: 05/27/2019] [Accepted: 06/05/2019] [Indexed: 12/14/2022]
Abstract
Atopic dermatitis (AD) is a complex inflammatory disorder with multiple interactions between genetic, immune and external factors. The sum of external factors that an individual is exposed to throughout their lifetime is termed the exposome. The exposome spans multiple domains from population to molecular levels and, in combination with genetic factors, holds the key to understanding the phenotypic diversity seen in AD patients. Exposomal domains are categorized into nonspecific (human and natural factors affecting populations), specific (eg humidity, ultraviolet radiation, diet, pollution, allergens, water hardness) and internal (cutaneous and gut microbiota and host cell interaction) exposures. The skin, as the organ that most directly interacts with and adapts to the external environment, is a prime target for exploration of exposomal influences on disease. Given the well-recognized physical environmental influences on AD, this condition could be much better understood through insightful exposomal research. In this narrative review, we examine each domain in turn, highlighting current understanding of the mechanisms by which exposomal influences modulate AD pathogenesis at distinct points in time. We highlight current approaches to exposome modification in AD and other allergic disease and propose future directions for exposome characterization and modification using novel research techniques.
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Affiliation(s)
| | - Carsten Flohr
- Unit for Population‐Based Dermatology Research, St John's Institute of DermatologyGuy's & St Thomas’ NHS Foundation Trust and King's College LondonLondonUK
| | - Alan D. Irvine
- Department of Paediatric DermatologyOur Lady’s Children’s Hospital CrumlinDublinIreland
- National Children’s Research Centre, Crumlin and Clinical MedicineTrinity College DublinDublinIreland
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Mathelié-Guinlet M, Viela F, Viljoen A, Dehullu J, Dufrêne YF. Single-molecule atomic force microscopy studies of microbial pathogens. CURRENT OPINION IN BIOMEDICAL ENGINEERING 2019. [DOI: 10.1016/j.cobme.2019.08.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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Abstract
The microbiome is defined as the sum of microbes, their genomes, and interactions in a given ecological niche. Atopic dermatitis is a multifactorial chronic inflammatory skin disease leading to dryness and itchiness of the skin. It is often associated with comorbidities such as allergic rhinoconjunctivitis and asthma. Today, culture-free techniques have been established to define microbes and their genomes that may be both detrimental and beneficial for their host. There are signs that microbes, both on skin and in the gut, may influence the course of atopic dermatitis. Antiseptic treatment has been used for decades, however now, with the help of traditional culture-based methods and modern metagenomics, we are beginning to understand that targeted treatment of dysbiosis may possibly become part of an integrated therapy plan in the future.
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Drislane C, Irvine AD. The role of filaggrin in atopic dermatitis and allergic disease. Ann Allergy Asthma Immunol 2019; 124:36-43. [PMID: 31622670 DOI: 10.1016/j.anai.2019.10.008] [Citation(s) in RCA: 151] [Impact Index Per Article: 30.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2019] [Revised: 10/07/2019] [Accepted: 10/07/2019] [Indexed: 12/14/2022]
Abstract
OBJECTIVE To provide an overview of filaggrin biology and the role of filaggrin variants in atopic dermatitis (AD) and allergic disease. DATA SOURCES We performed a PubMed literature review consisting mainly of studies relating to filaggrin in the last 5 years. STUDY SELECTIONS We selected articles that were found in PubMed using the search terms filaggrin, atopic dermatitis, skin barrier, and atopy. RESULTS Filaggrin plays an important role in the development of AD and allergic disease. Novel methods in measuring filaggrin expression and identifying filaggrin mutations aid in stratifying this patient cohort. We review new insights into understanding the role of filaggrin in AD and allergic disease. CONCLUSION Filaggrin remains a very important player in the pathogenesis of atopic dermatitis and allergic disease. This review looks at recent studies that aid our understanding of this crucial epidermal protein.
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Affiliation(s)
| | - Alan D Irvine
- Department of Paediatric Dermatology, Our Lady's Children's Hospital Crumlin, Dublin, National Children's Research Centre, Crumlin and Clinical Medicine, Trinity College Dublin, Ireland.
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The MSCRAMM Family of Cell-Wall-Anchored Surface Proteins of Gram-Positive Cocci. Trends Microbiol 2019; 27:927-941. [PMID: 31375310 DOI: 10.1016/j.tim.2019.06.007] [Citation(s) in RCA: 71] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2019] [Revised: 06/10/2019] [Accepted: 06/19/2019] [Indexed: 01/21/2023]
Abstract
The microbial surface components recognizing adhesive matrix molecules (MSCRAMMs) are a family of proteins that are defined by the presence of two adjacent IgG-like folded subdomains. These promote binding to ligands by mechanisms that involve major conformational changes exemplified by the binding to fibrinogen by the 'dock-lock-latch' mechanism or to collagen by the 'collagen hug'. Clumping factors A and B are two such MSCRAMMs that have several important roles in the pathogenesis of Staphylococcus aureus infections. MSCRAMM architecture, ligand binding, and roles in infection and colonization are examined with a focus on recent developments with clumping factors.
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