1
|
Nicolaou A, Kendall AC. Bioactive lipids in the skin barrier mediate its functionality in health and disease. Pharmacol Ther 2024; 260:108681. [PMID: 38897295 DOI: 10.1016/j.pharmthera.2024.108681] [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: 02/05/2024] [Revised: 05/11/2024] [Accepted: 06/13/2024] [Indexed: 06/21/2024]
Abstract
Our skin protects us from external threats including ultraviolet radiation, pathogens and chemicals, and prevents excessive trans-epidermal water loss. These varied activities are reliant on a vast array of lipids, many of which are unique to skin, and that support physical, microbiological and immunological barriers. The cutaneous physical barrier is dependent on a specific lipid matrix that surrounds terminally-differentiated keratinocytes in the stratum corneum. Sebum- and keratinocyte-derived lipids cover the skin's surface and support and regulate the skin microbiota. Meanwhile, lipids signal between resident and infiltrating cutaneous immune cells, driving inflammation and its resolution in response to pathogens and other threats. Lipids of particular importance include ceramides, which are crucial for stratum corneum lipid matrix formation and therefore physical barrier functionality, fatty acids, which contribute to the acidic pH of the skin surface and regulate the microbiota, as well as the stratum corneum lipid matrix, and bioactive metabolites of these fatty acids, involved in cell signalling, inflammation, and numerous other cutaneous processes. These diverse and complex lipids maintain homeostasis in healthy skin, and are implicated in many cutaneous diseases, as well as unrelated systemic conditions with skin manifestations, and processes such as ageing. Lipids also contribute to the gut-skin axis, signalling between the two barrier sites. Therefore, skin lipids provide a valuable resource for exploration of healthy cutaneous processes, local and systemic disease development and progression, and accessible biomarker discovery for systemic disease, as well as an opportunity to fully understand the relationship between the host and the skin microbiota. Investigation of skin lipids could provide diagnostic and prognostic biomarkers, and help identify new targets for interventions. Development and improvement of existing in vitro and in silico approaches to explore the cutaneous lipidome, as well as advances in skin lipidomics technologies, will facilitate ongoing progress in skin lipid research.
Collapse
Affiliation(s)
- Anna Nicolaou
- Laboratory for Lipidomics and Lipid Biology, Division of Pharmacy and Optometry, School of Health Sciences, Faculty of Biology Medicine and Health, The University of Manchester, Manchester Academic Health Science Centre, Manchester M13 9NT, UK; Lydia Becker Institute of Immunology and Inflammation; Faculty of Biology, Medicine and Health, The University of Manchester, Manchester Academic Health Science Centre, Manchester M13 9NT, UK.
| | - Alexandra C Kendall
- Laboratory for Lipidomics and Lipid Biology, Division of Pharmacy and Optometry, School of Health Sciences, Faculty of Biology Medicine and Health, The University of Manchester, Manchester Academic Health Science Centre, Manchester M13 9NT, UK
| |
Collapse
|
2
|
Shamaprasad P, Nădăban A, Iacovella CR, Gooris GS, Bunge AL, Bouwstra JA, McCabe C. The phase behavior of skin-barrier lipids: A combined approach of experiments and simulations. Biophys J 2024:S0006-3495(24)00477-6. [PMID: 39030908 DOI: 10.1016/j.bpj.2024.07.018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2024] [Revised: 04/28/2024] [Accepted: 07/15/2024] [Indexed: 07/22/2024] Open
Abstract
Skin barrier function is localized in its outermost layer, the stratum corneum (SC), which is comprised of corneocyte cells embedded in an extracellular lipid matrix containing ceramides (CERs), cholesterol (CHOL), and free fatty acids (FFAs). The unique structure and composition of this lipid matrix are important for skin barrier function. In this study, experiments and molecular dynamics simulation were combined to investigate the structural properties and phase behavior of mixtures containing nonhydroxy sphingosine CER (CER NS), CHOL, and FFA. X-ray scattering for mixtures with varying CHOL levels revealed the presence of the 5.4 nm short periodicity phase in the presence of CHOL. Bilayers in coarse-grained multilayer simulations of the same compositions contained domains with thicknesses of approximately 5.3 and 5.8 nm that are associated with elevated levels, respectively, of CER sphingosine chains with CHOL, and CER acyl chains with FFA chains. The prevalence of the thicker domain increased with decreasing CHOL content. This might correspond to a phase with ∼5.8 nm spacing observed by x-rays (other details unknown) in mixtures with lower CHOL content. Scissoring and stretching frequencies from Fourier transform infrared spectroscopy (FTIR) also indicate interaction between FFA and CER acyl chains and little interaction between CER acyl and CER sphingosine chains, which requires CER molecules to adopt a predominantly extended conformation. In the simulated systems, neighbor preferences of extended CER chains align more closely with the FTIR observations than those of CERs with hairpin ceramide chains. Both FTIR and atomistic simulations of reverse mapped multilayer membranes detect a hexagonal to fluid phase transition between 65 and 80°C. These results demonstrate the utility of a collaborative experimental and simulation effort in gaining a more comprehensive understanding of SC lipid membranes.
Collapse
Affiliation(s)
- Parashara Shamaprasad
- Department of Chemical and Biomolecular Engineering, Vanderbilt University, Nashville, Tennessee
| | - Andreea Nădăban
- Division of BioTherapeutics, Leiden Academic Centre for Drug Research, Leiden University, Leiden, the Netherlands
| | - Christopher R Iacovella
- Department of Chemical and Biomolecular Engineering, Vanderbilt University, Nashville, Tennessee
| | - Gerrit S Gooris
- Division of BioTherapeutics, Leiden Academic Centre for Drug Research, Leiden University, Leiden, the Netherlands
| | - Annette L Bunge
- Department of Chemical and Biological Engineering, Colorado School of Mines, Golden, Colorado
| | - Joke A Bouwstra
- Division of BioTherapeutics, Leiden Academic Centre for Drug Research, Leiden University, Leiden, the Netherlands
| | - Clare McCabe
- Department of Chemical and Biomolecular Engineering, Vanderbilt University, Nashville, Tennessee; School of Engineering and Physical Science, Heriot-Watt University, Edinburgh, United Kingdom.
| |
Collapse
|
3
|
Nădăban A, Gooris GS, Beddoes CM, Dalgliesh RM, Malfois M, Demé B, Bouwstra JA. The molecular arrangement of ceramides in the unit cell of the long periodicity phase of stratum corneum models shows a high adaptability to different ceramide head group structures. BIOCHIMICA ET BIOPHYSICA ACTA. BIOMEMBRANES 2024; 1866:184324. [PMID: 38688405 DOI: 10.1016/j.bbamem.2024.184324] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2023] [Revised: 03/06/2024] [Accepted: 04/11/2024] [Indexed: 05/02/2024]
Abstract
The stratum corneum (SC) lipid matrix, composed primarily of ceramides (CERs), cholesterol and free fatty acids (FFA), has an important role for the skin barrier function. The presence of the long periodicity phase (LPP), a unique lamellar phase, is characteristic for the SC. Insight into the lipid molecular arrangement within the LPP unit cell is imperative for understanding the relationship between the lipid subclasses and the skin barrier function. In this study, the impact of the CER head group structure on the lipid arrangement and barrier functionality was investigated using lipid models forming the LPP. The results demonstrate that the positions of CER N-(tetracosanoyl)-sphingosine (CER NS) and CER N-(tetracosanoyl)-phytosphingosine (CER NP), two essentials CER subclasses, are not influenced by the addition of another CER subclass (N-(tetracosanoyl)-dihydrosphingosine (CER NdS), N-(2R-hydroxy-tetracosanoyl)-sphingosine (CER AS) or D-(2R-hydroxy-tetracosanoyl)-phytosphingosine (CER AP)). However, differences are observed in the lipid organization and the hydrogen bonding network of the three different models. A similar localization of CER NP and CER NS is also observed in a more complex lipid model, with the CER subclass composition mimicking that of human SC. These studies show the adaptability and insensitivity of the LPP unit cell structure to changes in the lipid head group structures of the CER subclasses.
Collapse
Affiliation(s)
- Andreea Nădăban
- Division of BioTherapeutics, Leiden Academic Centre for Drug Research, Leiden University, Einsteinweg 55, Leiden 2333CC, the Netherlands
| | - Gerrit S Gooris
- Division of BioTherapeutics, Leiden Academic Centre for Drug Research, Leiden University, Einsteinweg 55, Leiden 2333CC, the Netherlands
| | - Charlotte M Beddoes
- Division of BioTherapeutics, Leiden Academic Centre for Drug Research, Leiden University, Einsteinweg 55, Leiden 2333CC, the Netherlands
| | - Robert M Dalgliesh
- ISIS Neutron and Muon Source, Science and Technology Facilities Council, Rutherford Appleton Laboratory, Harwell Oxford, Didcot OX11 0QX, United Kingdom
| | - Marc Malfois
- ALBA Synchrotron, Carrer de la Llum 2-6, Cerdanyola del Vallès 08290, Barcelona, Spain
| | - Bruno Demé
- Institut Laue-Langevin, 38000 Grenoble, France
| | - Joke A Bouwstra
- Division of BioTherapeutics, Leiden Academic Centre for Drug Research, Leiden University, Einsteinweg 55, Leiden 2333CC, the Netherlands.
| |
Collapse
|
4
|
Dwivedi A, Mazumder A, Pullmannová P, Paraskevopoulou A, Opálka L, Kováčik A, Macháček M, Jančálková P, Svačinová P, Peterlik H, Maixner J, Vávrová K. Lipid Monolayer on Cell Surface Protein Templates Functional Extracellular Lipid Assembly. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2024; 20:e2307793. [PMID: 38243890 DOI: 10.1002/smll.202307793] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Revised: 12/18/2023] [Indexed: 01/22/2024]
Abstract
When the ancestors of men moved from aquatic habitats to the drylands, their evolutionary strategy to restrict water loss is to seal the skin surface with lipids. It is unknown how these rigid ceramide-dominated lipids with densely packed chains squeeze through narrow extracellular spaces and how they assemble into their complex multilamellar architecture. Here it is shown that the human corneocyte lipid envelope, a monolayer of ultralong covalently bound lipids on the cell surface protein, templates the functional barrier assembly by partly fluidizing and rearranging the free extracellular lipids in its vicinity during the sculpting of a functional skin lipid barrier. The lipid envelope also maintains the fluidity of the extracellular lipids during mechanical stress. This local lipid fluidization does not compromise the permeability barrier. The results provide new testable hypotheses about epidermal homeostasis and the pathophysiology underlying diseases with impaired lipid binding to corneocytes, such as congenital ichthyosis. In a broader sense, this lipoprotein-mediated fluidization of rigid (sphingo)lipid patches may also be relevant to lipid rafts and cellular signaling events and inspire new functional materials.
Collapse
Affiliation(s)
- Anupma Dwivedi
- Skin Barrier Research Group, Faculty of Pharmacy, Charles University, Heyrovského 1203, Hradec Králové, 50005, Czech Republic
| | - Anisha Mazumder
- Skin Barrier Research Group, Faculty of Pharmacy, Charles University, Heyrovského 1203, Hradec Králové, 50005, Czech Republic
| | - Petra Pullmannová
- Skin Barrier Research Group, Faculty of Pharmacy, Charles University, Heyrovského 1203, Hradec Králové, 50005, Czech Republic
| | - Anna Paraskevopoulou
- Skin Barrier Research Group, Faculty of Pharmacy, Charles University, Heyrovského 1203, Hradec Králové, 50005, Czech Republic
- Department of Pharmaceutical Technology, Faculty of Pharmacy, Charles University, Heyrovského 1203, Hradec Králové, 50005, Czech Republic
| | - Lukáš Opálka
- Skin Barrier Research Group, Faculty of Pharmacy, Charles University, Heyrovského 1203, Hradec Králové, 50005, Czech Republic
| | - Andrej Kováčik
- Skin Barrier Research Group, Faculty of Pharmacy, Charles University, Heyrovského 1203, Hradec Králové, 50005, Czech Republic
- Department of Pharmaceutical Technology, Faculty of Pharmacy, Charles University, Heyrovského 1203, Hradec Králové, 50005, Czech Republic
| | - Miloslav Macháček
- Department of Biochemical Sciences, Faculty of Pharmacy, Charles University, Heyrovského 1203, Hradec Králové, 50005, Czech Republic
| | - Pavla Jančálková
- Skin Barrier Research Group, Faculty of Pharmacy, Charles University, Heyrovského 1203, Hradec Králové, 50005, Czech Republic
| | - Petra Svačinová
- Department of Pharmaceutical Technology, Faculty of Pharmacy, Charles University, Heyrovského 1203, Hradec Králové, 50005, Czech Republic
| | - Herwig Peterlik
- Faculty of Physics, University of Vienna, Boltzmanngasse 5, Vienna, 1090, Austria
| | - Jaroslav Maixner
- Faculty of Chemical Technology, University of Chemistry and Technology Prague, Technická 5, Prague, 16628, Czech Republic
| | - Kateřina Vávrová
- Skin Barrier Research Group, Faculty of Pharmacy, Charles University, Heyrovského 1203, Hradec Králové, 50005, Czech Republic
| |
Collapse
|
5
|
Fukuda K, Ito Y, Furuichi Y, Matsui T, Horikawa H, Miyano T, Okada T, van Logtestijn M, Tanaka RJ, Miyawaki A, Amagai M. Three stepwise pH progressions in stratum corneum for homeostatic maintenance of the skin. Nat Commun 2024; 15:4062. [PMID: 38750035 PMCID: PMC11096370 DOI: 10.1038/s41467-024-48226-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2023] [Accepted: 04/24/2024] [Indexed: 05/18/2024] Open
Abstract
The stratum corneum is the outermost skin layer with a vital role in skin barrier function. It is comprised of dead keratinocytes (corneocytes) and is known to maintain its thickness by shedding cells, although, the precise mechanisms that safeguard stratum corneum maturation and homeostasis remain unclear. Previous ex vivo studies have suggested a neutral-to-acidic pH gradient in the stratum corneum. Here, we use intravital pH imaging at single-corneocyte resolution to demonstrate that corneocytes actually undergo differentiation to develop three distinct zones in the stratum corneum, each with a distinct pH value. We identified a moderately acidic lower, an acidic middle, and a pH-neutral upper layer in the stratum corneum, with tight junctions playing a key role in their development. The upper pH neutral zone can adjust its pH according to the external environment and has a neutral pH under steady-state conditions owing to the influence of skin microbiota. The middle acidic pH zone provides a defensive barrier against pathogens. With mathematical modeling, we demonstrate the controlled protease activation of kallikrein-related peptidases on the stratum corneum surface that results in proper corneocyte shedding in desquamation. This work adds crucial information to our understanding of how stratum corneum homeostasis is maintained.
Collapse
Affiliation(s)
- Keitaro Fukuda
- Laboratory for Skin Homeostasis, RIKEN Center for Integrative Medical Sciences, Kanagawa, Japan
- Department of Dermatology, Keio University School of Medicine, Tokyo, Japan
| | - Yoshihiro Ito
- Department of Dermatology, Keio University School of Medicine, Tokyo, Japan
| | - Yuki Furuichi
- Laboratory for Skin Homeostasis, RIKEN Center for Integrative Medical Sciences, Kanagawa, Japan
- Department of Dermatology, Keio University School of Medicine, Tokyo, Japan
| | - Takeshi Matsui
- Laboratory for Skin Homeostasis, RIKEN Center for Integrative Medical Sciences, Kanagawa, Japan
- Department of Dermatology, Keio University School of Medicine, Tokyo, Japan
- Laboratory for Evolutionary Cell Biology of the Skin, School of Bioscience and Biotechnology, Tokyo University of Technology, Tokyo, Japan
| | - Hiroto Horikawa
- Laboratory for Skin Homeostasis, RIKEN Center for Integrative Medical Sciences, Kanagawa, Japan
- Department of Dermatology, Keio University School of Medicine, Tokyo, Japan
| | - Takuya Miyano
- Department of Bioengineering, Imperial College London, London, UK
| | - Takaharu Okada
- Laboratory for Tissue Dynamics, RIKEN Center for Integrative Medical Sciences, Kanagawa, Japan
- Graduate School of Medical Life Science, Yokohama City University, Kanagawa, Japan
| | | | - Reiko J Tanaka
- Department of Bioengineering, Imperial College London, London, UK
| | - Atsushi Miyawaki
- Laboratory for Cell Function Dynamics, RIKEN Center for Brain Science, Saitama, Japan
| | - Masayuki Amagai
- Laboratory for Skin Homeostasis, RIKEN Center for Integrative Medical Sciences, Kanagawa, Japan.
- Department of Dermatology, Keio University School of Medicine, Tokyo, Japan.
| |
Collapse
|
6
|
Jančálková P, Kopečná M, Kurka M, Kováčik A, Opálka L, Sagrafena I, Vávrová K. Skin Barrier Fine Tuning through Low-Temperature Lipid Chain Transition. J Invest Dermatol 2023; 143:2427-2435.e3. [PMID: 37394058 DOI: 10.1016/j.jid.2023.06.193] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2023] [Revised: 05/31/2023] [Accepted: 06/16/2023] [Indexed: 07/04/2023]
Abstract
The lipids in the mammalian stratum corneum (SC) adopt an unusually rigid arrangement to form a vital barrier preventing water loss and harmful environmental impacts. Just above the physiological temperature, a subset of barrier lipids undergoes a phase transition from a very tight orthorhombic to a looser hexagonal arrangement and vice versa. The purpose of this lipid transition in skin physiology is unknown. Permeability experiments on isolated human SC indicated that the transition affects the activation energy for a model compound that prefers lateral movement along lipid layers but not for water or a large polymer that would cross the SC through the pore pathway. The orthorhombic phase content of SC lipids, as determined by infrared spectroscopy, was also modulated by (de)hydration. Spontaneous rearrangement of human SC lipid monolayers into 10 nm higher multilamellar islets at 32-37 °C but not at room temperature was revealed by atomic force microscopy. Our findings add to our knowledge of fundamental skin physiology suggesting a fine temperature- and hydration-controlled switch from fluid lipids (required for lipid barrier assembly) to rigid and tightly packed lipids in the mature SC (necessary for the water and permeability barriers).
Collapse
Affiliation(s)
- Pavla Jančálková
- Skin Barrier Research Group, Faculty of Pharmacy in Hradec Králové, Charles University, Hradec Králové, Czech Republic
| | - Monika Kopečná
- Skin Barrier Research Group, Faculty of Pharmacy in Hradec Králové, Charles University, Hradec Králové, Czech Republic
| | - Michal Kurka
- Center of Materials and Nanotechnologies (CEMNAT), Faculty of Chemical Technology, University of Pardubice, Pardubice, Czech Republic
| | - Andrej Kováčik
- Skin Barrier Research Group, Faculty of Pharmacy in Hradec Králové, Charles University, Hradec Králové, Czech Republic
| | - Lukáš Opálka
- Skin Barrier Research Group, Faculty of Pharmacy in Hradec Králové, Charles University, Hradec Králové, Czech Republic
| | - Irene Sagrafena
- Skin Barrier Research Group, Faculty of Pharmacy in Hradec Králové, Charles University, Hradec Králové, Czech Republic
| | - Kateřina Vávrová
- Skin Barrier Research Group, Faculty of Pharmacy in Hradec Králové, Charles University, Hradec Králové, Czech Republic.
| |
Collapse
|
7
|
Norlén L. Molecular Organization of the Skin Barrier. Acta Derm Venereol 2023; 103:adv13356. [PMID: 37987626 PMCID: PMC10680981 DOI: 10.2340/actadv.v103.13356] [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: 05/22/2023] [Accepted: 10/19/2023] [Indexed: 11/22/2023] Open
Abstract
Cryo-electron microscopy of vitreous sections allows for investigation directly in situ of the molecular architecture of skin. Recently, this technique has contributed to the elucidation of the molecular organization of the skin's permeability barrier and its stepwise formation process. The aim of this review is to provide an overview of the procedure for cryo-electron microscopy of vitreous sections, its analysis using atomic detail molecular dynamics modelling and electron microscopy simulation, and its application in the investigation of the barrier structure and formation process of the skin.
Collapse
Affiliation(s)
- Lars Norlén
- Department of Cellular and Molecular Biology (CMB), Karolinska Institutet, Biomedicum, SE-171 77 Stockholm, Sweden.
| |
Collapse
|
8
|
Bouwstra JA, Nădăban A, Bras W, McCabe C, Bunge A, Gooris GS. The skin barrier: An extraordinary interface with an exceptional lipid organization. Prog Lipid Res 2023; 92:101252. [PMID: 37666282 PMCID: PMC10841493 DOI: 10.1016/j.plipres.2023.101252] [Citation(s) in RCA: 17] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2023] [Revised: 08/29/2023] [Accepted: 08/30/2023] [Indexed: 09/06/2023]
Abstract
The barrier function of the skin is primarily located in the stratum corneum (SC), the outermost layer of the skin. The SC is composed of dead cells with highly organized lipid lamellae in the intercellular space. As the lipid matrix forms the only continuous pathway, the lipids play an important role in the permeation of compounds through the SC. The main lipid classes are ceramides (CERs), cholesterol (CHOL) and free fatty acids (FFAs). Analysis of the SC lipid matrix is of crucial importance in understanding the skin barrier function, not only in healthy skin, but also in inflammatory skin diseases with an impaired skin barrier. In this review we provide i) a historical overview of the steps undertaken to obtain information on the lipid composition and organization in SC of healthy skin and inflammatory skin diseases, ii) information on the role CERs, CHOL and FFAs play in the lipid phase behavior of very complex lipid model systems and how this knowledge can be used to understand the deviation in lipid phase behavior in inflammatory skin diseases, iii) knowledge on the role of both, CER subclasses and chain length distribution, on lipid organization and lipid membrane permeability in complex and simple model systems with synthetic CERs, CHOL and FFAs, iv) similarity in lipid phase behavior in SC of different species and complex model systems, and vi) future directions in modulating lipid composition that is expected to improve the skin barrier in inflammatory skin diseases.
Collapse
Affiliation(s)
- Joke A Bouwstra
- Division of Biotherapeutics, Leiden Academic Centre for Drug Research, Leiden University, Leiden, The Netherlands.
| | - Andreea Nădăban
- Division of Biotherapeutics, Leiden Academic Centre for Drug Research, Leiden University, Leiden, The Netherlands
| | - Wim Bras
- Chemical Sciences Division, Oak Ridge National Laboratory, One Bethel Valley Road, Oak Ridge, TN 37831, United States of America
| | - Clare McCabe
- School of Engineering & Physical Science, Heriot-Watt University, Edinburgh, Scotland, UK
| | - Annette Bunge
- Department of Chemical and Biological Engineering, Colorado School of Mines, Golden, CO 80401, United States of America
| | - Gerrit S Gooris
- Division of Biotherapeutics, Leiden Academic Centre for Drug Research, Leiden University, Leiden, The Netherlands
| |
Collapse
|
9
|
de Szalay S, Wertz PW. Protective Barriers Provided by the Epidermis. Int J Mol Sci 2023; 24:ijms24043145. [PMID: 36834554 PMCID: PMC9961209 DOI: 10.3390/ijms24043145] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2022] [Revised: 01/30/2023] [Accepted: 02/02/2023] [Indexed: 02/09/2023] Open
Abstract
The skin is the largest organ of the body and consists of an epidermis, dermis and subcutaneous adipose tissue. The skin surface area is often stated to be about 1.8 to 2 m2 and represents our interface with the environment; however, when one considers that microorganisms live in the hair follicles and can enter sweat ducts, the area that interacts with this aspect of the environment becomes about 25-30 m2. Although all layers of the skin, including the adipose tissue, participate in antimicrobial defense, this review will focus mainly on the role of the antimicrobial factors in the epidermis and at the skin surface. The outermost layer of the epidermis, the stratum corneum, is physically tough and chemically inert which protects against numerous environmental stresses. It provides a permeability barrier which is attributable to lipids in the intercellular spaces between the corneocytes. In addition to the permeability barrier, there is an innate antimicrobial barrier at the skin surface which involves antimicrobial lipids, peptides and proteins. The skin surface has a low surface pH and is poor in certain nutrients, which limits the range of microorganisms that can survive there. Melanin and trans-urocanic acid provide protection from UV radiation, and Langerhans cells in the epidermis are poised to monitor the local environment and to trigger an immune response as needed. Each of these protective barriers will be discussed.
Collapse
Affiliation(s)
- Sarah de Szalay
- Sarah de Szalay Consulting, LLC, Wesy Milford, NJ 07480, USA
| | - Philip W. Wertz
- Dows Institute for Dental Research, College of Dentistry, University of Iowa, Iowa City, IA 52240, USA
- Correspondence:
| |
Collapse
|
10
|
Pullmannová P, Čuříková-Kindlová BA, Ondrejčeková V, Kováčik A, Dvořáková K, Dulanská L, Georgii R, Majcher A, Maixner J, Kučerka N, Zbytovská J, Vávrová K. Polymorphism, Nanostructures, and Barrier Properties of Ceramide-Based Lipid Films. ACS OMEGA 2023; 8:422-435. [PMID: 36643519 PMCID: PMC9835644 DOI: 10.1021/acsomega.2c04924] [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] [Received: 08/03/2022] [Accepted: 12/02/2022] [Indexed: 06/17/2023]
Abstract
Ceramides belong to sphingolipids, an important group of cellular and extracellular lipids. Their physiological functions range from cell signaling to participation in the formation of barriers against water evaporation. In the skin, they are essential for the permeability barrier, together with free fatty acids and cholesterol. We examined the periodical structure and permeability of lipid films composed of ceramides (Cer; namely, N-lignoceroyl 6-hydroxysphingosine, CerNH24, and N-lignoceroyl sphingosine, CerNS24), lignoceric acid (LIG; 24:0), and cholesterol (Chol). X-ray diffraction experiments showed that the CerNH24-based samples form either a short lamellar phase (SLP, d ∼ 5.4 nm) or a medium lamellar phase (MLP, d = 10.63-10.78 nm) depending on the annealing conditions. The proposed molecular arrangement of the MLP based on extended Cer molecules also agreed with the relative neutron scattering length density profiles obtained from the neutron diffraction data. The presence of MLP increased the lipid film permeability to the lipophilic model permeant (indomethacin) relative to the CerNS24-based control samples and the samples that had the same lipid composition but formed an SLP. Thus, the arrangement of lipids in various nanostructures is responsive to external conditions during sample preparation. This polymorphic behavior directly affects the barrier properties, which could also be (patho)physiologically relevant.
Collapse
Affiliation(s)
- Petra Pullmannová
- Skin
Barrier Research Group, Charles University, Faculty of Pharmacy in Hradec Králové, Heyrovského 1203, 500 05Hradec Králové, Czech Republic
| | - Barbora A. Čuříková-Kindlová
- Faculty
of Chemical Technology, University of Chemistry
and Technology Prague, Technická 5, 166 28Prague, Czech Republic
| | - Veronika Ondrejčeková
- Skin
Barrier Research Group, Charles University, Faculty of Pharmacy in Hradec Králové, Heyrovského 1203, 500 05Hradec Králové, Czech Republic
| | - Andrej Kováčik
- Skin
Barrier Research Group, Charles University, Faculty of Pharmacy in Hradec Králové, Heyrovského 1203, 500 05Hradec Králové, Czech Republic
| | - Kristýna Dvořáková
- Faculty
of Chemical Technology, University of Chemistry
and Technology Prague, Technická 5, 166 28Prague, Czech Republic
| | - Lucia Dulanská
- Skin
Barrier Research Group, Charles University, Faculty of Pharmacy in Hradec Králové, Heyrovského 1203, 500 05Hradec Králové, Czech Republic
| | - Robert Georgii
- Heinz
Maier-Leibnitz Zentrum (MLZ), Technische
Universität München, Lichtenbergstr. 1, 85748Garching, Germany
| | - Adam Majcher
- Skin
Barrier Research Group, Charles University, Faculty of Pharmacy in Hradec Králové, Heyrovského 1203, 500 05Hradec Králové, Czech Republic
| | - Jaroslav Maixner
- Faculty
of Chemical Technology, University of Chemistry
and Technology Prague, Technická 5, 166 28Prague, Czech Republic
| | - Norbert Kučerka
- Faculty
of Pharmacy, Comenius University Bratislava, Odbojárov 10, 832 32Bratislava, Slovakia
- Frank
Laboratory of Neutron Physics, Joint Institute
for Nuclear Research, Joliot-Curie 6, 141980Dubna, Russia
| | - Jarmila Zbytovská
- Skin
Barrier Research Group, Charles University, Faculty of Pharmacy in Hradec Králové, Heyrovského 1203, 500 05Hradec Králové, Czech Republic
- Faculty
of Chemical Technology, University of Chemistry
and Technology Prague, Technická 5, 166 28Prague, Czech Republic
| | - Kateřina Vávrová
- Skin
Barrier Research Group, Charles University, Faculty of Pharmacy in Hradec Králové, Heyrovského 1203, 500 05Hradec Králové, Czech Republic
| |
Collapse
|
11
|
Ri JS, Choe CS, Choe SH, Jong KH, Hong SN, Schleusener J, Lademann J, Darvin ME. Lycopene, but not zeaxanthin, serves as a skeleton for the formation of an orthorhombic organization of intercellular lipids within the lamellae in the stratum corneum: Molecular dynamics simulations of the hydrated ceramide NS bilayer model. BIOCHIMICA ET BIOPHYSICA ACTA. BIOMEMBRANES 2023; 1865:184081. [PMID: 36342013 DOI: 10.1016/j.bbamem.2022.184081] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Revised: 10/24/2022] [Accepted: 10/25/2022] [Indexed: 11/06/2022]
Abstract
Carotenoids play an important role in the protection of biomembranes against oxidative damage. Their function depends on the surroundings and the organization of the lipid membrane they are embedded in. Carotenoids are located parallel or perpendicular to the surface of the lipid bilayer. The influence of carotenoids on the organization of the lipid bilayer in the stratum corneum has not been thoroughly considered. Here, the orientation of the exemplary cutaneous carotenoids lycopene and zeaxanthin in a hydrated ceramide NS24 bilayer model and the influence of carotenoids on the lateral organization of the lipid bilayer model were studied by means of molecular dynamics simulations for 32 °C and 37 °C. The results confirm that lycopene is located parallel and zeaxanthin perpendicular to the surface of the lipid bilayer. The lycopene-loaded lipid bilayer appeared to have a strong orthorhombic organization, while zeaxanthin-loaded and pure lipid bilayers were organized in a disordered hexagonal-like and liquid-like state, respectively. The effect is stronger at 32 °C compared to 37 °C based on p-values. Therefore, it was assumed that carotenoids without hydroxyl polar groups in their structure facilitate the formation of the orthorhombic organization of lipids, which provides the skin barrier function. It was shown that the distance between carotenoid atoms matched the distance between atoms in the lipids, indicating that parallel located carotenoids without hydroxyl groups serve as a skeleton for lipid membranes inside the lamellae. The obtained results provide reasonable prediction of the overall qualitative properties of lipid model systems and show the importance of parallel-oriented carotenoids in the development and maintenance of the skin barrier function.
Collapse
Affiliation(s)
- Jin-Song Ri
- Faculty of Materials Science, Kim Il Sung University, Pyongyang, Democratic People's Republic of Korea
| | - Chun-Sik Choe
- Faculty of Materials Science, Kim Il Sung University, Pyongyang, Democratic People's Republic of Korea
| | - Se-Hyok Choe
- Faculty of Materials Science, Kim Il Sung University, Pyongyang, Democratic People's Republic of Korea
| | - Kwang-Hyok Jong
- Faculty of Physics, Kim Il Sung University, Pyongyang, Democratic People's Republic of Korea
| | - Song-Nam Hong
- Faculty of Materials Science, Kim Il Sung University, Pyongyang, Democratic People's Republic of Korea
| | - Johannes Schleusener
- Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Department of Dermatology, Venerology and Allergology, Center of Experimental and Applied Cutaneous Physiology, Charitéplatz 1, 10117 Berlin, Germany.
| | - Juergen Lademann
- Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Department of Dermatology, Venerology and Allergology, Center of Experimental and Applied Cutaneous Physiology, Charitéplatz 1, 10117 Berlin, Germany
| | - Maxim E Darvin
- Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Department of Dermatology, Venerology and Allergology, Center of Experimental and Applied Cutaneous Physiology, Charitéplatz 1, 10117 Berlin, Germany
| |
Collapse
|
12
|
Prado-Mantilla A, Lechler T. Polarity in skin development and cancer. Curr Top Dev Biol 2023; 154:317-336. [PMID: 37100522 DOI: 10.1016/bs.ctdb.2023.02.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/12/2023]
Abstract
The epidermis is a stratified squamous epithelium that forms the outermost layer of the skin. Its primary function is to act as a barrier, keeping pathogens and toxins out and moisture in. This physiological role has necessitated major differences in the organization and polarity of the tissue as compared to simple epithelia. We discuss four aspects of polarity in the epidermis - the distinctive polarities of basal progenitor cells as well as differentiated granular cells, the polarity of adhesions and the cytoskeleton across the tissue as keratinocytes differentiate, and the planar cell polarity of the tissue. These distinctive polarities are essential for the morphogenesis and the function of the epidermis and have also been implicated in regulating tumor formation.
Collapse
|
13
|
Cholesterol Sulfate Fluidizes the Sterol Fraction of the Stratum Corneum Lipid Phase and Increases its Permeability. J Lipid Res 2022; 63:100177. [PMID: 35143845 PMCID: PMC8953687 DOI: 10.1016/j.jlr.2022.100177] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Revised: 02/02/2022] [Accepted: 02/03/2022] [Indexed: 12/02/2022] Open
Abstract
Desulfation of cholesterol sulfate (CholS) to cholesterol (Chol) is an important event in epidermal homeostasis and necessary for stratum corneum (SC) barrier function. The CholS/Chol ratio decreases during SC maturation but remains high in pathological conditions, such as X-linked ichthyosis, characterized by dry and scaly skin. The aim of this study was to characterize the influence of the CholS/Chol molar ratio on the structure, dynamics, and permeability of SC lipid model mixtures. We synthesized deuterated CholS and investigated lipid models with specifically deuterated components using 2H solid-state NMR spectroscopy at temperatures from 25°C to 80°C. Although the rigid acyl chains in ceramides and fatty acids remained essentially rigid upon variation of the CholS/Chol ratio, both sterols were increasingly fluidized in lipid models containing higher CholS concentrations. We also show the X-ray repeat distance of the lipid lamellar phase (105 Å) and the orthorhombic chain packing of the ceramide’s acyl chains and long free fatty acids did not change upon the variation of the CholS content. However, the Chol phase separation visible in models with high Chol concentration disappeared at the 50:50 CholS/Chol ratio. This increased fluidity resulted in higher permeabilities to model markers of these SC models. These results reveal that a high CholS/Chol ratio fluidizes the sterol fraction and increases the permeability of the SC lipid phase while maintaining the lamellar lipid arrangement with an asymmetric sterol distribution.
Collapse
|
14
|
Sagrafena I, Paraskevopoulos G, Pullmannová P, Opálka L, Nováčková A, Lourantou O, Vávrová K. Assembly of Human Stratum Corneum Lipids In Vitro: Fluidity Matters. J Invest Dermatol 2021; 142:2036-2039.e3. [PMID: 34942198 DOI: 10.1016/j.jid.2021.12.008] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Revised: 11/23/2021] [Accepted: 12/06/2021] [Indexed: 11/25/2022]
Affiliation(s)
- Irene Sagrafena
- Skin Barrier Research Group, Charles University, Faculty of Pharmacy, Akademika Heyrovského 1203, 500 05 Hradec Králové, Czech Republic
| | - Georgios Paraskevopoulos
- Skin Barrier Research Group, Charles University, Faculty of Pharmacy, Akademika Heyrovského 1203, 500 05 Hradec Králové, Czech Republic
| | - Petra Pullmannová
- Skin Barrier Research Group, Charles University, Faculty of Pharmacy, Akademika Heyrovského 1203, 500 05 Hradec Králové, Czech Republic
| | - Lukáš Opálka
- Skin Barrier Research Group, Charles University, Faculty of Pharmacy, Akademika Heyrovského 1203, 500 05 Hradec Králové, Czech Republic
| | - Anna Nováčková
- Skin Barrier Research Group, Charles University, Faculty of Pharmacy, Akademika Heyrovského 1203, 500 05 Hradec Králové, Czech Republic
| | - Ourania Lourantou
- Skin Barrier Research Group, Charles University, Faculty of Pharmacy, Akademika Heyrovského 1203, 500 05 Hradec Králové, Czech Republic
| | - Kateřina Vávrová
- Skin Barrier Research Group, Charles University, Faculty of Pharmacy, Akademika Heyrovského 1203, 500 05 Hradec Králové, Czech Republic.
| |
Collapse
|
15
|
Cracking the Skin Barrier: Liquid-Liquid Phase Separation Shines under the Skin. JID INNOVATIONS 2021; 1:100036. [PMID: 34909733 PMCID: PMC8659386 DOI: 10.1016/j.xjidi.2021.100036] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2021] [Revised: 06/07/2021] [Accepted: 06/18/2021] [Indexed: 12/25/2022] Open
Abstract
Central to forming and sustaining the skin’s barrier, epidermal keratinocytes (KCs) fluxing to the skin surface undergo a rapid and enigmatic transformation into flat, enucleated squames. At the crux of this transformation are intracellular keratohyalin granules (KGs) that suddenly disappear as terminally differentiating KCs transition to the cornified skin surface. Defects in KGs have long been linked to skin barrier disorders. Through the biophysical lens of liquid-liquid phase separation (LLPS), these enigmatic KGs recently emerged as liquid-like membraneless organelles whose assembly and subsequent pH-triggered disassembly drive squame formation. To stimulate future efforts toward cracking the complex process of skin barrier formation, in this review, we integrate the key concepts and foundational work spanning the fields of LLPS and epidermal biology. We review the current progress in the skin and discuss implications in the broader context of membraneless organelles across stratifying epithelia. The discovery of environmentally sensitive LLPS dynamics in the skin points to new avenues for dissecting the skin barrier and for addressing skin barrier disorders. We argue that skin and its appendages offer outstanding models to uncover LLPS-driven mechanisms in tissue biology.
Collapse
Key Words
- 3D, three-dimensional
- AD, atopic dermatitis
- CE, cornified envelope
- EDC, epidermal differentiation complex
- ER, endoplasmic reticulum
- IDP, intrinsically-disordered protein
- KC, keratinocyte
- KG, keratohyalin granule
- LCST, lower critical solution temperature
- LLPS, liquid-liquid phase separation
- PTM, post-translational modification
- TG, trichohyalin granule
- UCST, upper critical solution temperature
Collapse
|
16
|
Asada N, Morita R, Kamiji R, Kuwajima M, Komorisono M, Yamamura T, Ono N, Kanaya S, Yoshikawa S. Evaluation of intercellular lipid lamellae in the stratum corneum by polarized microscopy. Skin Res Technol 2021; 28:391-401. [PMID: 34751451 PMCID: PMC9907717 DOI: 10.1111/srt.13109] [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: 08/02/2021] [Accepted: 09/25/2021] [Indexed: 11/29/2022]
Abstract
BACKGROUND Intercellular lipids contain a lamellar structure that glows in polarized images. It could be expected that the intercellular lipid content be estimated from the luminance values calculated from polarized images of stratum corneum strips. Therefore, we attempted to develop a method for simple and rapid evaluation of the intercellular lipid content through a procedure. Herein, we demonstrated a relationship between the luminance value and the amount of ceramides, one of the main components of intercellular lipids. MATERIALS AND METHODS The stratum corneum was collected from the forearm using slides with a pure rubber-based adhesive, which did not produce unnecessary luminescence under polarizing conditions. Images were analyzed using luminance indices. The positive secondary ion peak images were obtained using the time of flight-secondary ion mass spectrometry; the polarized and brightfield images were obtained using a polarized microscope. The ceramide and protein amount was measured by high-performance liquid chromatography and bicinchoninic acid protein assay after microscope imaging. Images and quantitative values were used to construct evaluation models based on a convolutional neural network (CNN). RESULTS There was a correlation between the highlighted areas of the polarized image to overlap with the area where ceramide-derived peak was detected. Evaluation of the CNN-based model of the polarized images predicted the amount of ceramides per unit of stratum corneum. CONCLUSION The method proposed in the study enabled a large number of specimens to provide a simple, rapid, and efficient evaluation of the intercellular lipid content.
Collapse
Affiliation(s)
- Naoki Asada
- KOBAYASHI Pharmaceutical, Co. Ltd., Ibaraki, Japan.,Department of Science and Technology, NARA Institute of Science and Technology, Ikoma, Japan
| | - Ryo Morita
- KOBAYASHI Pharmaceutical, Co. Ltd., Ibaraki, Japan
| | - Rikae Kamiji
- KOBAYASHI Pharmaceutical, Co. Ltd., Ibaraki, Japan
| | | | | | | | - Naoaki Ono
- Department of Science and Technology, NARA Institute of Science and Technology, Ikoma, Japan.,Data Science Center, NARA Institute of Science and Technology, Ikoma, Japan
| | - Shigehiko Kanaya
- Department of Science and Technology, NARA Institute of Science and Technology, Ikoma, Japan
| | | |
Collapse
|
17
|
Roberts MS, Cheruvu HS, Mangion SE, Alinaghi A, Benson HA, Mohammed Y, Holmes A, van der Hoek J, Pastore M, Grice JE. Topical drug delivery: History, percutaneous absorption, and product development. Adv Drug Deliv Rev 2021; 177:113929. [PMID: 34403750 DOI: 10.1016/j.addr.2021.113929] [Citation(s) in RCA: 88] [Impact Index Per Article: 29.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Revised: 08/05/2021] [Accepted: 08/11/2021] [Indexed: 02/07/2023]
Abstract
Topical products, widely used to manage skin conditions, have evolved from simple potions to sophisticated delivery systems. Their development has been facilitated by advances in percutaneous absorption and product design based on an increasingly mechanistic understanding of drug-product-skin interactions, associated experiments, and a quality-by-design framework. Topical drug delivery involves drug transport from a product on the skin to a local target site and then clearance by diffusion, metabolism, and the dermal circulation to the rest of the body and deeper tissues. Insights have been provided by Quantitative Structure Permeability Relationships (QSPR), molecular dynamics simulations, and dermal Physiologically Based PharmacoKinetics (PBPK). Currently, generic product equivalents of reference-listed products dominate the topical delivery market. There is an increasing regulatory interest in understanding topical product delivery behavior under 'in use' conditions and predicting in vivo response for population variations in skin barrier function and response using in silico and in vitro findings.
Collapse
|
18
|
The Skin's Barrier: A Cryo-EM Based Overview of its Architecture and Stepwise Formation. J Invest Dermatol 2021; 142:285-292. [PMID: 34474746 DOI: 10.1016/j.jid.2021.06.037] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Revised: 06/28/2021] [Accepted: 06/30/2021] [Indexed: 01/22/2023]
Abstract
A major role of the skin is to serve as a barrier toward the environment. The skin's permeability barrier consists of a lipid structure positioned in the stratum corneum. Recent progress in high-resolution cryo-electron microscopy (cryo-EM) has allowed for elucidation of the architecture of the skin's barrier and its stepwise formation process representing the final stage of epidermal differentiation. In this review, we present an overview of the skin's barrier structure and its formation process, as evidenced by cryo-EM.
Collapse
|
19
|
Ohnari H, Sekiya M, Naru E, Ogura T, Sakata O, Obata Y. Amino Acids and Their N-Acetylated Derivatives Maintain the Skin's Barrier Function. Chem Pharm Bull (Tokyo) 2021; 69:652-660. [PMID: 34193714 DOI: 10.1248/cpb.c21-00152] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The hydrocarbon-chain packing structure of intercellular lipids in the stratum corneum (SC) is critical to the skin's barrier function. We previously found that formation of V-shaped ceramide reduces the barrier function of skin. There are few agents, apart from ceramides and fatty acids that can improve the orthorhombic packing (Orth) ratio of the intercellular lipid packing structure. In this study, we investigated agents that directly increase the Orth ratio. We selected an intercellular lipid model consisting of ceramide, cholesterol, and palmitic acid and performed differential scanning calorimetry. We focused on natural moisturizing factor components in the SC, and therefore investigated amino acids and their derivatives. The results of our intercellular lipid model-based study indicate that N-acetyl-L-hydroxyproline (AHYP), remarkably, maintains the lamellar structure. We verified the effect of AHYP on the lamellar structure and hydrocarbon chain packing structure of intercellular lipids using time-resolved X-ray diffraction measurements of human SC. We also determined the direct physicochemical effects of AHYP on the Orth ratio of the hydrocarbon-chain packing structure. Hence, the results of our human SC study suggest that AHYP preserves skin barrier function by maintaining the hydrocarbon-chain packing structure of intercellular lipids via electrostatic repulsion. These findings will facilitate the development of skincare formulation that can maintain the skin's barrier function.
Collapse
Affiliation(s)
| | | | - Eiji Naru
- Research and Development Division, KOSÉ Corporation
| | - Taku Ogura
- Research Institute for Science & Technology, Tokyo University of Science
| | - Osamu Sakata
- Research and Development Division, KOSÉ Corporation
| | - Yasuko Obata
- Department of Pharmaceutical Sciences, Hoshi University
| |
Collapse
|