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Fernandes E, Lopes CM, Lúcio M. Lipid Biomimetic Models as Simple Yet Complex Tools to Predict Skin Permeation and Drug-Membrane Biophysical Interactions. Pharmaceutics 2024; 16:807. [PMID: 38931927 PMCID: PMC11207520 DOI: 10.3390/pharmaceutics16060807] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2024] [Revised: 06/07/2024] [Accepted: 06/10/2024] [Indexed: 06/28/2024] Open
Abstract
The barrier function of the skin is primarily determined by its outermost layer, the Stratum Corneum (SC). The SC consists of corneocytes embedded in a lipid matrix composed mainly of ceramides, cholesterol, and free fatty acids in equimolar proportions and is organised in a complex lamellar structure with different periodicities and lateral packings. This matrix provides a diffusion pathway across the SC for bioactive compounds that are administered to the skin. In this regard, and as the skin administration route has grown in popularity, there has been an increase in the use of lipid mixtures that closely resemble the SC lipid matrix, either for a deeper biophysical understanding or for pharmaceutical and cosmetic purposes. This review focuses on a systematic analysis of the main outcomes of using lipid mixtures as SC lipid matrix models for pharmaceutical and cosmetic purposes. Thus, a methodical evaluation of the main outcomes based on the SC structure is performed, as well as the main recent developments in finding suitable new in vitro tools for permeation testing based on lipid models.
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Affiliation(s)
- Eduarda Fernandes
- CF-UM-UP—Centro de Física das Universidades do Minho e Porto, Departamento de Física, Universidade do Minho, 4710-057 Braga, Portugal
| | - Carla M. Lopes
- FFP-I3ID—Instituto de Investigação, Inovação e Desenvolvimento, FP-BHS—Biomedical and Health Sciences Research Unit, Faculdade de Ciências da Saúde, Universidade Fernando Pessoa, 4200–150 Porto, Portugal;
- UCIBIO—Applied Molecular Biosciences Unit, MedTech–Laboratory of Pharmaceutical Technology, Faculty of Pharmacy, University of Porto, 4050-313 Porto, Portugal
- Associate Laboratory i4HB, Institute for Health and Bioeconomy, Faculty of Pharmacy, University of Porto, 4050-313 Porto, Portugal
| | - Marlene Lúcio
- CF-UM-UP—Centro de Física das Universidades do Minho e Porto, Departamento de Física, Universidade do Minho, 4710-057 Braga, Portugal
- CBMA—Centro de Biologia Molecular e Ambiental, Departamento de Biologia, Universidade do Minho, 4710-057 Braga, Portugal
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2
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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.
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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
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3
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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.
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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
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4
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Shamaprasad P, Frame CO, Moore TC, Yang A, Iacovella CR, Bouwstra JA, Bunge AL, McCabe C. Using molecular simulation to understand the skin barrier. Prog Lipid Res 2022; 88:101184. [PMID: 35988796 PMCID: PMC10116345 DOI: 10.1016/j.plipres.2022.101184] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2022] [Revised: 08/11/2022] [Accepted: 08/12/2022] [Indexed: 11/15/2022]
Abstract
Skin's effectiveness as a barrier to permeation of water and other chemicals rests almost entirely in the outermost layer of the epidermis, the stratum corneum (SC), which consists of layers of corneocytes surrounded by highly organized lipid lamellae. As the only continuous path through the SC, transdermal permeation necessarily involves diffusion through these lipid layers. The role of the SC as a protective barrier is supported by its exceptional lipid composition consisting of ceramides (CERs), cholesterol (CHOL), and free fatty acids (FFAs) and the complete absence of phospholipids, which are present in most biological membranes. Molecular simulation, which provides molecular level detail of lipid configurations that can be connected with barrier function, has become a popular tool for studying SC lipid systems. We review this ever-increasing body of literature with the goals of (1) enabling the experimental skin community to understand, interpret and use the information generated from the simulations, (2) providing simulation experts with a solid background in the chemistry of SC lipids including the composition, structure and organization, and barrier function, and (3) presenting a state of the art picture of the field of SC lipid simulations, highlighting the difficulties and best practices for studying these systems, to encourage the generation of robust reproducible studies in the future. This review describes molecular simulation methodology and then critically examines results derived from simulations using atomistic and then coarse-grained models.
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Affiliation(s)
- Parashara Shamaprasad
- Department of Chemical and Biomolecular Engineering, Vanderbilt University, Nashville, TN 37235-1604, United States of America; Multiscale Modeling and Simulation (MuMS) Center, Vanderbilt University, Nashville, TN 37235-1604, United States of America
| | - Chloe O Frame
- Department of Chemical and Biomolecular Engineering, Vanderbilt University, Nashville, TN 37235-1604, United States of America; Multiscale Modeling and Simulation (MuMS) Center, Vanderbilt University, Nashville, TN 37235-1604, United States of America
| | - Timothy C Moore
- Department of Chemical and Biomolecular Engineering, Vanderbilt University, Nashville, TN 37235-1604, United States of America; Multiscale Modeling and Simulation (MuMS) Center, Vanderbilt University, Nashville, TN 37235-1604, United States of America
| | - Alexander Yang
- Department of Chemical and Biomolecular Engineering, Vanderbilt University, Nashville, TN 37235-1604, United States of America; Multiscale Modeling and Simulation (MuMS) Center, Vanderbilt University, Nashville, TN 37235-1604, United States of America
| | - Christopher R Iacovella
- Department of Chemical and Biomolecular Engineering, Vanderbilt University, Nashville, TN 37235-1604, United States of America; Multiscale Modeling and Simulation (MuMS) Center, Vanderbilt University, Nashville, TN 37235-1604, United States of America
| | - Joke A Bouwstra
- Division of BioTherapeutics, LACDR, Leiden University, 2333 CC Leiden, the Netherlands
| | - Annette L Bunge
- Department of Chemical and Biological Engineering, Colorado School of Mines, Golden, CO 80401, United States of America
| | - Clare McCabe
- Department of Chemical and Biomolecular Engineering, Vanderbilt University, Nashville, TN 37235-1604, United States of America; Multiscale Modeling and Simulation (MuMS) Center, Vanderbilt University, Nashville, TN 37235-1604, United States of America; School of Engineering and Physical Science, Heriot-Watt University, Edinburgh, United Kingdom.
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5
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Shamaprasad P, Moore TC, Xia D, Iacovella CR, Bunge AL, McCabe C. Multiscale Simulation of Ternary Stratum Corneum Lipid Mixtures: Effects of Cholesterol Composition. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2022; 38:7496-7511. [PMID: 35671175 PMCID: PMC9309713 DOI: 10.1021/acs.langmuir.2c00471] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Molecular dynamics simulations of mixtures of the ceramide nonhydroxy-sphingosine (NS), cholesterol, and a free fatty acid are performed to gain molecular-level understanding of the structure of the lipids found in the stratum corneum layer of skin. A new coarse-grained force field for cholesterol was developed using the multistate iterative Boltzmann inversion (MS-IBI) method. The coarse-grained cholesterol force field is compatible with previously developed coarse-grained force fields for ceramide NS, free fatty acids, and water and validated against atomistic simulations of these lipids using the CHARMM force field. Self-assembly simulations of multilayer structures using these coarse-grained force fields are performed, revealing that a large fraction of the ceramides adopt extended conformations, which cannot occur in the single bilayer in water structures typically studied using molecular simulation. Cholesterol fluidizes the membrane by promoting packing defects, and an increase in cholesterol content is found to reduce the bilayer thickness due to an increase in interdigitation of the C24 lipid tails, consistent with experimental observations. Using a reverse-mapping procedure, a self-assembled coarse-grained multilayer system is used to construct an equivalent structure with atomistic resolution. Simulations of this atomistic structure are found to closely agree with experimentally derived neutron scattering length density profiles. Significant interlayer hydrogen bonding is observed in the inner layers of the atomistic multilayer structure that are not found in the outer layers in contact with water or in equivalent bilayer structures. This work highlights the importance of simulating multilayer structures, as compared to the more commonly studied bilayer systems, to enable more appropriate comparisons with multilayer experimental membranes. These results also provide validation of the efficacy of the MS-IBI derived coarse-grained force fields and the framework for multiscale simulation.
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Affiliation(s)
- Parashara Shamaprasad
- Department of Chemical and Biomolecular Engineering, Vanderbilt University, Nashville, TN, USA, 37235-1604
- Multiscale Modeling and Simulation (MuMS) Center, Vanderbilt University, Nashville, TN, USA, 37235-1604
| | - Timothy C. Moore
- Department of Chemical and Biomolecular Engineering, Vanderbilt University, Nashville, TN, USA, 37235-1604
- Multiscale Modeling and Simulation (MuMS) Center, Vanderbilt University, Nashville, TN, USA, 37235-1604
| | - Donna Xia
- Department of Chemical and Biomolecular Engineering, Vanderbilt University, Nashville, TN, USA, 37235-1604
- Multiscale Modeling and Simulation (MuMS) Center, Vanderbilt University, Nashville, TN, USA, 37235-1604
| | - Christopher R. Iacovella
- Department of Chemical and Biomolecular Engineering, Vanderbilt University, Nashville, TN, USA, 37235-1604
- Multiscale Modeling and Simulation (MuMS) Center, Vanderbilt University, Nashville, TN, USA, 37235-1604
| | - Annette L. Bunge
- Department of Chemical and Biological Engineering, Colorado School of Mines, Golden, CO, USA, 80401
| | - Clare McCabe
- Department of Chemical and Biomolecular Engineering, Vanderbilt University, Nashville, TN, USA, 37235-1604
- Multiscale Modeling and Simulation (MuMS) Center, Vanderbilt University, Nashville, TN, USA, 37235-1604
- Department of Chemistry, Vanderbilt University, Nashville, TN, USA, 37235-1604
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6
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Kováčik A, Pullmannová P, Opálka L, Šilarová M, Maixner J, Vávrová K. Effects of ( R)- and ( S)-α-Hydroxylation of Acyl Chains in Sphingosine, Dihydrosphingosine, and Phytosphingosine Ceramides on Phase Behavior and Permeability of Skin Lipid Models. Int J Mol Sci 2021; 22:ijms22147468. [PMID: 34299088 PMCID: PMC8303283 DOI: 10.3390/ijms22147468] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Revised: 07/08/2021] [Accepted: 07/09/2021] [Indexed: 11/16/2022] Open
Abstract
Ceramides (Cers) with α-hydroxylated acyl chains comprise about a third of all extractable skin Cers and are required for permeability barrier homeostasis. We have probed here the effects of Cer hydroxylation on their behavior in lipid models comprising the major SC lipids, Cer/free fatty acids (C 16-C 24)/cholesterol, and a minor component, cholesteryl sulfate. Namely, Cers with (R)-α-hydroxy lignoceroyl chains attached to sphingosine (Cer AS), dihydrosphingosine (Cer AdS), and phytosphingosine (Cer AP) were compared to their unnatural (S)-diastereomers and to Cers with non-hydroxylated lignoceroyl chains attached to sphingosine (Cer NS), dihydrosphingosine (Cer NdS), and phytosphingosine (Cer NP). By comparing several biophysical parameters (lamellar organization by X-ray diffraction, chain order, lateral packing, phase transitions, and lipid mixing by infrared spectroscopy using deuterated lipids) and the permeabilities of these models (water loss and two permeability markers), we conclude that there is no general or common consequence of Cer α-hydroxylation. Instead, we found a rich mix of effects, highly dependent on the sphingoid base chain, configuration at the α-carbon, and permeability marker used. We found that the model membranes with unnatural Cer (S)-AS have fewer orthorhombically packed lipid chains than those based on the (R)-diastereomer. In addition, physiological (R)-configuration decreases the permeability of membranes, with Cer (R)-AdS to theophylline, and increases the lipid chain order in model systems with natural Cer (R)-AP. Thus, each Cer subclass makes a distinct contribution to the structural organization and function of the skin lipid barrier.
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Affiliation(s)
- Andrej Kováčik
- Skin Barrier Research Group, Faculty of Pharmacy in Hradec Králové, Charles University, Akademika Heyrovského 1203, 500 05 Hradec Králové, Czech Republic; (P.P.); (L.O.); (M.Š.); (K.V.)
- Correspondence: ; Tel.: +420-495-067-340
| | - Petra Pullmannová
- Skin Barrier Research Group, Faculty of Pharmacy in Hradec Králové, Charles University, Akademika Heyrovského 1203, 500 05 Hradec Králové, Czech Republic; (P.P.); (L.O.); (M.Š.); (K.V.)
| | - Lukáš Opálka
- Skin Barrier Research Group, Faculty of Pharmacy in Hradec Králové, Charles University, Akademika Heyrovského 1203, 500 05 Hradec Králové, Czech Republic; (P.P.); (L.O.); (M.Š.); (K.V.)
| | - Michaela Šilarová
- Skin Barrier Research Group, Faculty of Pharmacy in Hradec Králové, Charles University, Akademika Heyrovského 1203, 500 05 Hradec Králové, Czech Republic; (P.P.); (L.O.); (M.Š.); (K.V.)
| | - Jaroslav Maixner
- Faculty of Chemical Technology, University of Chemistry and Technology in Prague, Technická 5, 166 28 Prague, Czech Republic;
| | - Kateřina Vávrová
- Skin Barrier Research Group, Faculty of Pharmacy in Hradec Králové, Charles University, Akademika Heyrovského 1203, 500 05 Hradec Králové, Czech Republic; (P.P.); (L.O.); (M.Š.); (K.V.)
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7
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Ohnari H, Naru E, Ogura T, Sakata O, Obata Y. Phase Separation in Lipid Lamellae Result from Ceramide Conformations and Lateral Packing Structure. Chem Pharm Bull (Tokyo) 2021; 69:72-80. [PMID: 33390523 DOI: 10.1248/cpb.c20-00588] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Intercellular lipids in the stratum corneum protect the living body from invasion by allergens and pathogens, and also suppresses water evaporation within the body. It is important to understand how differences in the microstructure of intercellular lipids arise. This microstructure is affected by lipid composition. Studies using intercellular lipid models have reported the formation of two phases with different short lamellar periodicities. However, the details of the packing structure characteristics of the two phases observed in these intercellular lipid models are unclear. Our previous report revealed that different short periodicity phases coexist in the N-(α-hydroxyoctadecanoyl)-dihydrosphingosine (CER[ADS]), cholesterol (CHOL), and palmitic acid (PA) complex model. In this study, the characteristics of the packing structure of two phases with different short lamellar periodicities, which were observed in the intercellular lipid model (CER[ADS]/CHOL/PA) that we used previously, were adjusted for models with different lipid compositions. The characteristics of the packed and lamellar structures have been determined by temperature-scanning small-angle X-ray scattering and wide-angle X-ray diffraction measurements simultaneously. These differences in lamellar structure were thought to be caused by differences in ceramides (CER) conformation between the hairpin and the V-shape type. The lamellar structure of the V-shaped CER conformation has a low orthorhombic ratio. The above results suggest that an increase in the ratio of CER with the V-shaped structure causes the lamellar structure to have low orthorhombic ratio, thereby contributing to a decrease in the bilayer's barrier function.
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Affiliation(s)
| | - Eiji Naru
- Research and Development Division, KOSE Corporation
| | - Taku Ogura
- Research Institute for Science & Technology, Tokyo University of Science
| | - Osamu Sakata
- Research and Development Division, KOSE Corporation
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8
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Schmitt T, Neubert RHH. State of the Art in Stratum Corneum Research. Part II: Hypothetical Stratum Corneum Lipid Matrix Models. Skin Pharmacol Physiol 2020; 33:213-230. [PMID: 32683377 DOI: 10.1159/000509019] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Accepted: 05/05/2020] [Indexed: 12/31/2022]
Abstract
This review is the second part of a series which presents the state of the art in stratum corneum (SC) lipid matrix (LM) research in depth. In this part, the various hypothetical models which were developed to describe the structure and function of the SC LM as the skin's barrier will be discussed. New as well as a cumulative assortment of older results which change the view on the different models are considered to conclude how well the different models are holding up today. As a final conclusion, a model, factoring in as much of the known data as possible, is concluded, unifying the varying different models into one which can be developed further, as new results are found in the future. So far, the model is described with a single crystalline or gel-like phase with a certain amount of nanocrystallites of concentrated ceramides (CERs) and free fatty acids and more fluid nanodomains caused by a fluidizing effect of the cholesterol. These domains are dynamically resolved and reformed and do not impair the barrier function. The chain conformation is not completely clear yet; however, an equilibrium of fully extended and hairpin-folded CERs with ratios depending on the properties of each individual CER species is proposed as most likely. An overlapping middle layer as described for the tri-layer model in part I of this series would be present for both conformations. The macroscopic broad-narrow-broad layering, observed in electron micrographs, is explained by an external templating by the lipid envelope, and an internal templating by short and long lipid chains each preferentially show a homophilic association, forming thicker and thinner bilayers, respectively. The degree of influence of the very long ω-hydroxy-CERs is discussed as well.
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Affiliation(s)
- Thomas Schmitt
- Department I, Institute of Anatomy and Cell Biology, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Reinhard H H Neubert
- Institute of Applied Dermatopharmacy at the Martin Luther University Halle-Wittenberg (IADP), Halle/Saale, Germany, .,Institute of Pharmacy, Martin Luther University Halle-Wittenberg, Halle/Saale, Germany,
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9
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Badhe Y, Gupta R, Rai B. Development and application of coarse-grained MARTINI model of skin lipid ceramide [AP]. J Mol Model 2020; 26:182. [PMID: 32583227 DOI: 10.1007/s00894-020-04435-z] [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: 08/02/2019] [Accepted: 06/02/2020] [Indexed: 01/10/2023]
Abstract
Stratum corneum (SC), the outermost layer of the skin, contains large variety of lipids, endowing them with the amphiphilic properties, needed to fulfil their key role in skin's barrier function. The individual role of lipid types in the barrier function is difficult to understand due to the immense heterogeneity and complexity of the lipid's organization within the SC. The lipid organization is being explored using both computational (molecular dynamics simulations) and experimental (neutron diffraction) techniques. Even though atomistic simulations provide unprecedented atomic level details, the major limitation is time and length scale that can be achieved with decent computational facility. Alternatively, coarse-grain (CG) models are currently being used to capture physics at bigger time and length scale without losing essential underlined structural information. In this study, a CG model of α-hydroxy phytosphingosines (CER[AP]) is developed based on philosophy of MARTINI force field. At first, the model is validated with various atomistic simulations and available experimental data. Later on, the model's compatibility with other major skin lipids, cholesterol, and free fatty acid (palmitic acid) is checked by simulating a mixture of lipid multilayer in presence and absence of water. The developed model of CER[AP] is able to predict key structural properties within the acceptable error limits. The phenomena of ceramide conformation transformation, cholesterol flip-flop, and specificity of lipid arrangement within the multilayered systems is observed during the simulation. This signifies the importance of model in capturing higher order structural transformations.
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Affiliation(s)
- Yogesh Badhe
- Physical Science Research Area, TCS Research, Tata Research Development and Design Centre, Tata Consultancy Services, 54B, Hadapsar Industrial Estate, Pune, 411013, India
| | - Rakesh Gupta
- Physical Science Research Area, TCS Research, Tata Research Development and Design Centre, Tata Consultancy Services, 54B, Hadapsar Industrial Estate, Pune, 411013, India.
| | - Beena Rai
- Physical Science Research Area, TCS Research, Tata Research Development and Design Centre, Tata Consultancy Services, 54B, Hadapsar Industrial Estate, Pune, 411013, India
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10
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State of the art in Stratum Corneum research: The biophysical properties of ceramides. Chem Phys Lipids 2018; 216:91-103. [PMID: 30291856 DOI: 10.1016/j.chemphyslip.2018.09.017] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2018] [Revised: 09/10/2018] [Accepted: 09/29/2018] [Indexed: 11/20/2022]
Abstract
This review is summarizing an important part of the state of the art in stratum corneum research. A complete overview on discoveries about the general biophysical and physicochemical properties of the known ceramide species' is provided. The ceramides are one of the three major components of the lipid matrix and mainly govern its properties and structure. They are shown to exhibit very little redundancy, despite the minor differences in their chemical structure. The results are discussed, compared to each other as well as the current base of knowledge. New interesting aspects and concepts are concluded or suggested. A novel interpretation of the 3-dimensional structure of the lipid matrix and its influence on the barrier function will be discussed. The most important conclusion is the presentation of a new and up to date theoretical model of the nanostructure of the short periodicity phase. The model suggests three perpendicular layers: The rigid head group region, the rigid chain region and, a liquid-like overlapping middle layer. The general principle of the skin barrier function is highlighted in regard to this structure and the ceramides biophysical and physicochemical properties. As a result of these considerations, the entropy vs. enthalpy principle is introduced, shedding light on the function as well as the effectiveness of the skin barrier. Additionally, general ideas to effectively overcome this barrier principle for dermal and transdermal delivery of actives or how to use it for specific targeting of the stratum corneum are proposed.
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Schmitt T, Gupta R, Lange S, Sonnenberger S, Dobner B, Hauß T, Rai B, Neubert RHH. Impact of the ceramide subspecies on the nanostructure of stratum corneum lipids using neutron scattering and molecular dynamics simulations. Part I: impact of CER[NS]. Chem Phys Lipids 2018; 214:58-68. [PMID: 29859142 DOI: 10.1016/j.chemphyslip.2018.05.006] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2018] [Revised: 05/18/2018] [Accepted: 05/28/2018] [Indexed: 11/19/2022]
Abstract
For this study mixtures based on the ceramides [NS] (NS = non-hydroxy-sphingosine) and [AP] (AP = α-hydroxy-phytosphingosine) in a 2:1 and 1:2 ratio, together with cholesterol and lignoceric acid, were investigated. These mixtures are modelling the uppermost skin layer, the stratum corneum. Neutron diffraction, utilizing specifically deuterated ceramide molecules, was used to obtain a maximum amount of experimental detail. Highly detailed molecular dynamics simulations were used to generate even more information from the experimental data. It was possible to observe a single lamellar phase for both systems. They had a lamellar repeat distance of 5.43 ± 0.05 nm for the [NS]/[AP] 2:1 and a slightly shorter one of 5.34 ± 0.05 nm for the 1:2 system. The structure and water content was uninfluenced by excess humidity. Both the experimental and simulation data indicated slightly tilted ceramides, with their C24 chains overlapping in the lamellar mid-plane. This arrangement is well comparable to systems investigated before. The structure of both systems, except for the differing repeat distance, looks similar at first. However, on a smaller scale there were various distinct differences, demonstrating only low redundancy between the different ceramide species, despite only minor chemical differences. The mainly ceramide [AP] determined 1:2 system has a slightly smaller repeat distance. This is a result of a tighter arrangement of the lipids chain along the bilayer normal and increased overlapping of the long chains in the lamellar middle. For the CER[NS] some novel features could be shown, despite it being the overall most investigated ceramide. These include the low adaptability to changed lateral interactions, leading to an increased chain opening. This effect could explain its low miscibility with other lipids. The investigated model systems allows it to directly compare results from the literature which have used ceramide [NS] to the most recent studies using the phytosphingosine ceramides such as ceramide [AP].
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Affiliation(s)
- Thomas Schmitt
- Institute of Applied Dermatopharmacy at the Martin Luther University Halle-Wittenberg (IADP), Weinbergweg 23, 06120 Halle/Saale, Germany
| | - Rakesh Gupta
- Physical Science Research Area, TCS Research, Tata Research Development and Design Centre, Tata Consultancy Services, 54B, Hadapsar Industrial Estate, Pune, 411013, India
| | - Stefan Lange
- Institute of Medical Physics and Biophysics, University of Leipzig, Härtelstraße 16-18, 04107 Leipzig, Germany
| | - Stefan Sonnenberger
- Institute of Pharmacy, Martin Luther University Halle-Wittenberg (MLU), Wolfgang-Langenbeck-Str. 4, 06120 Halle/Saale, Germany
| | - Bodo Dobner
- Institute of Pharmacy, Martin Luther University Halle-Wittenberg (MLU), Wolfgang-Langenbeck-Str. 4, 06120 Halle/Saale, Germany
| | - Thomas Hauß
- Helmholtz-Zentrum Berlin für Materialien und Energie (HZB), Hahn-Meitner-Platz 1, 14109, Berlin, Germany
| | - Beena Rai
- Physical Science Research Area, TCS Research, Tata Research Development and Design Centre, Tata Consultancy Services, 54B, Hadapsar Industrial Estate, Pune, 411013, India
| | - Reinhard H H Neubert
- Institute of Applied Dermatopharmacy at the Martin Luther University Halle-Wittenberg (IADP), Weinbergweg 23, 06120 Halle/Saale, Germany; Institute of Medical Physics and Biophysics, University of Leipzig, Härtelstraße 16-18, 04107 Leipzig, Germany.
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Schmitt T, Lange S, Dobner B, Sonnenberger S, Hauß T, Neubert RHH. Investigation of a CER[NP]- and [AP]-Based Stratum Corneum Modeling Membrane System: Using Specifically Deuterated CER Together with a Neutron Diffraction Approach. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2018; 34:1742-1749. [PMID: 28949139 DOI: 10.1021/acs.langmuir.7b01848] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Neutron diffraction was used as a tool to investigate the lamellar as well as molecular nanostructure of ceramide-[NP]/ceramide-[AP]/cholesterol/lignoceric acid model systems with a nativelike 2:1 ratio and a 1:2 ratio to study the influence of the ceramide-[AP]. By using mixtures together with cholesterol and free fatty acids as well as a humidity and temperature chamber while measuring, natural conditions were simulated as closely as possible. Despite its simplicity, the system simulated the native stratum corneum lipid matrix fairly closely, showing a similar lamellar thickness with a repeat distance of 5.45 ± 0.1 nm and a similar arrangement with overlapping long C24 chains. Furthermore, despite the very minor chemical difference between ceramide-[NP] and ceramide-[AP], which is only a single OH group, it was possible to demonstrate substantial differences between the structural influence of the two ceramides. Ceramide-[AP] could be concluded to be arranged in such a way that its C24 chain in both ratios is somehow shorter than that of ceramide-[NP], not overlapping as much with the opposite lamellar leaflet. Furthermore, in the unnatural 1:2 ratio, the higher ceramide-[AP] content causes an increased tilt of the ceramide acyl chains. This leads to even less overlapping within the lamellar midplane, whereas the repeat distance stays the same as for the ceramide-[NP]-rich system. In this nativelike 2:1 ratio, the chains are arranged mostly straight, and the long C24 chains show a broad overlapping region in the lamellar midplane.
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Affiliation(s)
- Thomas Schmitt
- Institute of Applied Dermatopharmacy, Martin Luther University Halle-Wittenberg (IADP) , Weinbergweg 23, 06120 Halle/Saale, Germany
| | - Stefan Lange
- Institute of Medical Physics and Biophysics, University of Leipzig , Härtelstraße 16-18, 04107 Leipzig, Germany
| | - Bodo Dobner
- Institute of Pharmacy, Martin Luther University Halle-Wittenberg (MLU) , Wolfgang-Langenbeck-Str. 4, 06120 Halle/Saale, Germany
| | - Stefan Sonnenberger
- Institute of Pharmacy, Martin Luther University Halle-Wittenberg (MLU) , Wolfgang-Langenbeck-Str. 4, 06120 Halle/Saale, Germany
| | - Thomas Hauß
- Helmholtz-Zentrum Berlin für Materialien und Energie (HZB) , Hahn-Meitner-Platz 1, 14109 Berlin, Germany
| | - Reinhard H H Neubert
- Institute of Applied Dermatopharmacy, Martin Luther University Halle-Wittenberg (IADP) , Weinbergweg 23, 06120 Halle/Saale, Germany
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Stahlberg S, Eichner A, Sonnenberger S, Kováčik A, Lange S, Schmitt T, Demé B, Hauß T, Dobner B, Neubert RHH, Huster D. Influence of a Novel Dimeric Ceramide Molecule on the Nanostructure and Thermotropic Phase Behavior of a Stratum Corneum Model Mixture. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2017; 33:9211-9221. [PMID: 28819979 DOI: 10.1021/acs.langmuir.7b01227] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The stratum corneum (SC) is the outermost layer of the skin and is composed of a multilayered assembly of mostly ceramids (Cer), free fatty acids, cholesterol (Chol), and cholesterol sulfate (Chol-S). Because of the tight packing of these lipids, the SC features unique barrier properties defending the skin from environmental influences. Under pathological conditions, where the skin barrier function is compromised, topical application of molecules that rigidify the SC may lead to a restored barrier function. To this end, molecules are required that incorporate into the SC and bring back the original rigidity of the skin barrier. Here, we investigated the influence of a novel dimeric ceramide (dim-Cer) molecule designed to feature a long, rigid hydrocarbon chain ideally suited to forming an orthorhombic lipid phase. The influence of this molecules on the thermotropic phase behavior of a SC mixture consisting of Cer[AP18] (55 wt %), cholesterol (Chol, 25 wt %), steric acid (SA, 15 wt %), and cholesterol sulfate (Chol-S, 5 wt %) was studied using a combination of neutron diffraction and 2H NMR spectroscopy. These methods provide detailed insights into the packing properties of the lipids in the SC model mixture. Dim-Cer remains in an all-trans state of the membrane-spanning lipid chain at all investigated temperatures, but the influence on the phase behavior of the other lipids in the mixture is marginal. Biophysical experiments are complemented by permeability measurements in model membranes and human skin. The latter, however, indicates that dim-Cer only partially provides the desired effect on membrane permeability, necessitating further optimization of its structure for medical applications.
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Affiliation(s)
- Sören Stahlberg
- Institute for Medical Physics and Biophysics, Leipzig University , Leipzig, Germany
| | - Adina Eichner
- Institute of Pharmacy and #Institute of Applied Dermatopharmacy, Martin Luther University Halle-Wittenberg , Halle (Saale), Germany
| | - Stefan Sonnenberger
- Institute for Medical Physics and Biophysics, Leipzig University , Leipzig, Germany
- Institute of Pharmacy and #Institute of Applied Dermatopharmacy, Martin Luther University Halle-Wittenberg , Halle (Saale), Germany
| | - Andrej Kováčik
- Institute for Medical Physics and Biophysics, Leipzig University , Leipzig, Germany
- Skin Barrier Research Group, Faculty of Pharmacy in Hradec Králové, Charles University , Akademika Heyrovského 1203, 50005 Hradec Králové, Czech Republic
| | - Stefan Lange
- Institute of Pharmacy and #Institute of Applied Dermatopharmacy, Martin Luther University Halle-Wittenberg , Halle (Saale), Germany
| | - Thomas Schmitt
- Institute of Pharmacy and #Institute of Applied Dermatopharmacy, Martin Luther University Halle-Wittenberg , Halle (Saale), Germany
- Institute of Soft Matter and Functional Materials, Helmholtz-Zentrum Berlin für Materialien und Energie , Berlin, Germany
| | - Bruno Demé
- Institute Laue-Langevin (ILL) , Grenoble, France
| | - Thomas Hauß
- Institute of Soft Matter and Functional Materials, Helmholtz-Zentrum Berlin für Materialien und Energie , Berlin, Germany
| | - Bodo Dobner
- Institute of Pharmacy and #Institute of Applied Dermatopharmacy, Martin Luther University Halle-Wittenberg , Halle (Saale), Germany
| | - Reinhard H H Neubert
- Institute of Pharmacy and #Institute of Applied Dermatopharmacy, Martin Luther University Halle-Wittenberg , Halle (Saale), Germany
| | - Daniel Huster
- Institute for Medical Physics and Biophysics, Leipzig University , Leipzig, Germany
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Permeability and microstructure of model stratum corneum lipid membranes containing ceramides with long (C16) and very long (C24) acyl chains. Biophys Chem 2017; 224:20-31. [DOI: 10.1016/j.bpc.2017.03.004] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2016] [Revised: 02/09/2017] [Accepted: 03/19/2017] [Indexed: 02/07/2023]
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Schroeter A, Stahlberg S, Školová B, Sonnenberger S, Eichner A, Huster D, Vávrová K, Hauß T, Dobner B, Neubert RHH, Vogel A. Phase separation in ceramide[NP] containing lipid model membranes: neutron diffraction and solid-state NMR. SOFT MATTER 2017; 13:2107-2119. [PMID: 28225091 DOI: 10.1039/c6sm02356h] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
The stratum corneum is the outermost layer of the skin and protects the organism against external influences as well as water loss. It consists of corneocytes embedded in a mixture of ceramides, fatty acids, and cholesterol in a molar ratio of roughly 1 : 1 : 1. The unique structural and compositional arrangement of these stratum corneum lipids is responsible for the skin barrier properties. Many studies investigated the organization of these barrier lipids and, in particular, the exact conformation of ceramides. However, so far no consensus has been reached. In this study, we investigate a model system comprised of N-(non-hydroxy-tetracosanoyl)-phytosphingosine/cholesterol/tetracosanoic acid (CER[NP]-C24/CHOL/TA) at a 1 : 1 : 1 molar ratio using neutron diffraction and 2H solid-state NMR spectroscopy at temperatures from 25 °C to 80 °C. Deuterated variants of all three lipid components of the model system were used to enable their separate investigation in the NMR spectra and quantification of the amount of molecules in each phase. Neutron scattering experiments show the coexistence of two lipid phases at low temperatures with repeat spacings of 54.2 Å and 43.0 Å at a physiological skin temperature of 32 °C. They appear to be indistinguishable in the 2H NMR spectra as both phases are crystalline and ceramide molecules do not rotate around their long axis on a microsecond timescale. The evolution of these phases upon heating is followed and with increasing temperature fluid and even isotropically mobile molecules are observed. A model of the organization of the lamellar phases is proposed in which the thicker phase consists of CER[NP]-C24 in a hairpin conformation mixed with CHOL and TA, while the phase with a repeat spacing of 43.0 Å contains CER[NP]-C24 in a V-shape conformation.
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Affiliation(s)
- Annett Schroeter
- Institute of Pharmacy, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany
| | - Sören Stahlberg
- Institute for Medical Physics and Biophysics, University of Leipzig, Härtelstraße 16-18, D-04107 Leipzig, Germany.
| | - Barbora Školová
- Institute for Medical Physics and Biophysics, University of Leipzig, Härtelstraße 16-18, D-04107 Leipzig, Germany. and Faculty of Pharmacy, Charles University, Akademika Heyrovského 1203, 50005 Hradec Králové, Czech Republic
| | - Stefan Sonnenberger
- Institute of Pharmacy, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany
| | - Adina Eichner
- Institute of Pharmacy, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany
| | - Daniel Huster
- Institute for Medical Physics and Biophysics, University of Leipzig, Härtelstraße 16-18, D-04107 Leipzig, Germany.
| | - Kateřina Vávrová
- Faculty of Pharmacy, Charles University, Akademika Heyrovského 1203, 50005 Hradec Králové, Czech Republic
| | - Thomas Hauß
- Institute of Soft Matter and Functional Materials, Helmholtz-Zentrum für Materialien und Energie, Berlin, Germany
| | - Bodo Dobner
- Institute of Pharmacy, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany
| | - Reinhard H H Neubert
- Institute of Pharmacy, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany and Institute of Applied Dermatopharmacy at the Martin Luther University Halle-Wittenberg, Halle (Saale), Germany
| | - Alexander Vogel
- Institute for Medical Physics and Biophysics, University of Leipzig, Härtelstraße 16-18, D-04107 Leipzig, Germany.
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Fatty acids penetration into human skin ex vivo: A TOF-SIMS analysis approach. Biointerphases 2017; 12:011003. [DOI: 10.1116/1.4977941] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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Stratum corneum lipid matrix: Location of acyl ceramide and cholesterol in the unit cell of the long periodicity phase. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2016; 1858:1926-34. [PMID: 27169629 DOI: 10.1016/j.bbamem.2016.05.006] [Citation(s) in RCA: 58] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2016] [Accepted: 05/05/2016] [Indexed: 01/04/2023]
Abstract
The extracellular lipid matrix in the skin's outermost layer, the stratum corneum, is crucial for the skin barrier. The matrix is composed of ceramides (CERs), cholesterol (CHOL) and free fatty acids (FFAs) and involves two lamellar phases: the short periodicity phase (SPP) and the long periodicity phase (LPP). To understand the skin barrier thoroughly, information about the molecular arrangement in the unit cell of these lamellar phases is paramount. Previously we examined the molecular arrangement in the unit cell of the SPP. Furthermore X-ray and neutron diffraction revealed a trilayer arrangement of lipids within the unit cell of the LPP [D. Groen et al., Biophysical Journal, 97, 2242-2249, 2009]. In the present study, we used neutron diffraction to obtain more details about the location of lipid (sub)classes in the unit cell of the LPP. The diffraction pattern revealed at least 8 diffraction orders of the LPP with a repeating unit of 129.6±0.5Å. To determine the location of lipid sub(classes) in the unit cell, samples were examined with either only protiated lipids or selectively deuterated lipids. The diffraction data obtained by means of D2O/H2O contrast variation together with a gradual replacement of one particular CER, the acyl CER, by its partly deuterated counterpart, were used to construct the scattering length density profiles. The acyl chain of the acyl CER subclass is located at a position of ~21.4±0.2Å from the unit cell centre of the LPP. The position and orientation of CHOL in the LPP unit cell were determined using tail and head-group deuterated forms of the sterol. CHOL is located with its head-group positioned ~26±0.2Å from the unit cell centre. This allows the formation of a hydrogen bond with the ester group of the acyl CER located in close proximity. Based on the positions of the deuterated moieties of the acyl CER, CHOL and the previously determined location of two other lipid subclasses [E.H. Mojumdar et al., Biophysical Journal, 108, 2670-2679, 2015], a molecular model is proposed for the unit cell of the LPP. In this model CHOL is located in the two outer layers of the LPP, while CER EOS is linking the two outer layers with the central lipid layers. Finally the two other lipid subclasses are predominantly located in the central layer of the LPP.
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Mojumdar EH, Gooris GS, Barlow DJ, Lawrence MJ, Deme B, Bouwstra JA. Skin lipids: localization of ceramide and fatty acid in the unit cell of the long periodicity phase. Biophys J 2016; 108:2670-9. [PMID: 26039168 DOI: 10.1016/j.bpj.2015.04.030] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2014] [Revised: 03/17/2015] [Accepted: 04/21/2015] [Indexed: 12/22/2022] Open
Abstract
The lipid matrix of the skin's stratum corneum plays a key role in the barrier function, which protects the body from desiccation. The lipids that make up this matrix consist of ceramides, cholesterol, and free fatty acids, and can form two coexisting crystalline lamellar phases: the long periodicity phase (LPP) and the short periodicity phase (SPP). To fully understand the skin barrier function, information on the molecular arrangement of the lipids in the unit cell of these lamellar phases is very desirable. To determine this arrangement in previous studies, we examined the molecular arrangement of the SPP. In this study, neutron diffraction studies were performed to obtain information on the molecular arrangement of the LPP. The diffraction pattern reveals nine diffraction orders attributed to the LPP with a repeating unit of 129.4 ± 0.5 Å. Using D2O/H2O contrast variation, the scattering length density profiles were calculated for protiated samples and samples that included either the perdeuterated acyl chain of the most abundant ceramide or the most abundant perdeuterated fatty acid. Both perdeuterated chains are predominantly located in the central part of the unit cell with substantial interdigitation of the acyl chains in the unit cell center. However, a fraction of the perdeuterated chains is also located near the border of the unit cell with their acyl chains directing toward the center. This arrangement of lipids in the LPP unit cell corresponds with the location of their lipid headgroups at the border and also inside of the unit cell at a well-defined position (±21 Å from the unit cell center), indicative of a three-layer lipid arrangement within the 129.4 ± 0.5 Å repeating unit.
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Affiliation(s)
- Enamul H Mojumdar
- Leiden Academic Centre for Drug Research, Department of Drug Delivery Technology, Gorlaeus Laboratories, University of Leiden, Leiden, the Netherlands
| | - Gert S Gooris
- Leiden Academic Centre for Drug Research, Department of Drug Delivery Technology, Gorlaeus Laboratories, University of Leiden, Leiden, the Netherlands
| | - David J Barlow
- Pharmaceutical Science Division, King's College London, London, United Kingdom
| | - M Jayne Lawrence
- Pharmaceutical Science Division, King's College London, London, United Kingdom
| | - Bruno Deme
- Institute Laue-Langevin, Grenoble, France
| | - Joke A Bouwstra
- Leiden Academic Centre for Drug Research, Department of Drug Delivery Technology, Gorlaeus Laboratories, University of Leiden, Leiden, the Netherlands.
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Grassi S, Prioni S, Cabitta L, Aureli M, Sonnino S, Prinetti A. The Role of 3-O-Sulfogalactosylceramide, Sulfatide, in the Lateral Organization of Myelin Membrane. Neurochem Res 2015; 41:130-43. [DOI: 10.1007/s11064-015-1747-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2015] [Revised: 10/22/2015] [Accepted: 10/24/2015] [Indexed: 12/12/2022]
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MacDermaid CM, DeVane RH, Klein ML, Fiorin G. Dehydration of multilamellar fatty acid membranes: towards a computational model of the stratum corneum. J Chem Phys 2015; 141:22D526. [PMID: 25494797 DOI: 10.1063/1.4902363] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The level of hydration controls the cohesion between apposed lamellae of saturated free fatty acids found in the lipid matrix of stratum corneum, the outermost layer of mammalian skin. This multilamellar lipid matrix is highly impermeable to water and ions, so that the local hydration shell of its fatty acids may not always be in equilibrium with the acidity and relative humidity, which significantly change over a course of days during skin growth. The homeostasis of the stratum corneum at each moment of its growth likely requires a balance between two factors, which affect in opposite ways the diffusion of hydrophilic species through the stratum corneum: (i) an increase in water order as the lipid lamellae come in closer contact, and (ii) a decrease in water order as the fraction of charged fatty acids is lowered by pH. Herein molecular dynamics simulations are employed to estimate the impact of both effects on water molecules confined between lamellae of fatty acids. Under conditions where membrane undulations are energetically favorable, the charged fatty acids are able to sequester cations around points of contact between lamellae that are fully dehydrated, while essentially maintaining a multilamellar structure for the entire system. This observation suggests that the undulations of the fatty acid lamellae control the diffusion of hydrophilic species through the water phase by altering the positional and rotational order of water molecules in the embedded/occluded "droplets."
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Affiliation(s)
- Christopher M MacDermaid
- Institute for Computational Molecular Science, SERC Building (035-07), Temple University, 1925 North 12th Street, Philadelphia, Pennsylvania 19122, USA
| | - Russell H DeVane
- Modeling and Simulation, Corporate Research and Development, The Procter and Gamble Company, West Chester, Ohio 45069, USA
| | - Michael L Klein
- Institute for Computational Molecular Science, SERC Building (035-07), Temple University, 1925 North 12th Street, Philadelphia, Pennsylvania 19122, USA
| | - Giacomo Fiorin
- Institute for Computational Molecular Science, SERC Building (035-07), Temple University, 1925 North 12th Street, Philadelphia, Pennsylvania 19122, USA
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Chiricozzi E, Ciampa MG, Brasile G, Compostella F, Prinetti A, Nakayama H, Ekyalongo RC, Iwabuchi K, Sonnino S, Mauri L. Direct interaction, instrumental for signaling processes, between LacCer and Lyn in the lipid rafts of neutrophil-like cells. J Lipid Res 2014; 56:129-41. [PMID: 25418321 DOI: 10.1194/jlr.m055319] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Lactosylceramide [LacCer; β-Gal-(1-4)-β-Glc-(1-1)-Cer] has been shown to contain very long fatty acids that specifically modulate neutrophil properties. The interactions between LacCer and proteins and their role in cell signaling processes were assessed by synthesizing two molecular species of azide-photoactivable tritium-labeled LacCer having acyl chains of different lengths. The lengths of the two acyl chains corresponded to those of a short/medium and very long fatty acid, comparable to the lengths of stearic and lignoceric acids, respectively. These derivatives, designated C18-[(3)H]LacCer-(N3) and C24-[(3)H]LacCer-(N3), were incorporated into the lipid rafts of plasma membranes of neutrophilic differentiated HL-60 (D-HL-60) cells. C24-[(3)H]LacCer-(N3), but not C18-[(3)H]LacCer-(N3), induced the phosphorylation of Lyn and promoted phagocytosis. Incorporation of C24-[(3)H]LacCer-(N3) into plasma membranes, followed by illumination, resulted in the formation of several tritium-labeled LacCer-protein complexes, including the LacCer-Lyn complex, into plasma membrane lipid rafts. Administration of C18-[(3)H]LacCer-(N3) to cells, however, did not result in the formation of the LacCer-Lyn complex. These results suggest that LacCer derivatives mimic the biological properties of natural LacCer species and can be utilized as tools to study LacCer-protein interactions, and confirm a specific direct interaction between LacCer species containing very long fatty acids, and Lyn protein, associated with the cytoplasmic layer via myristic/palmitic chains.
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Affiliation(s)
- Elena Chiricozzi
- Department of Medical Biotechnology and Translational Medicine, University of Milan, Milano, Italy
| | - Maria Grazia Ciampa
- Department of Medical Biotechnology and Translational Medicine, University of Milan, Milano, Italy
| | - Giuseppina Brasile
- Department of Medical Biotechnology and Translational Medicine, University of Milan, Milano, Italy
| | - Federica Compostella
- Department of Medical Biotechnology and Translational Medicine, University of Milan, Milano, Italy
| | - Alessandro Prinetti
- Department of Medical Biotechnology and Translational Medicine, University of Milan, Milano, Italy
| | - Hitoshi Nakayama
- Institute for Environmental Gender-Specific Medicine, Juntendo University Graduate School of Medicine, Chiba, Japan
| | - Roudy C Ekyalongo
- Institute for Environmental Gender-Specific Medicine, Juntendo University Graduate School of Medicine, Chiba, Japan
| | - Kazuhisa Iwabuchi
- Institute for Environmental Gender-Specific Medicine, Juntendo University Graduate School of Medicine, Chiba, Japan
| | - Sandro Sonnino
- Department of Medical Biotechnology and Translational Medicine, University of Milan, Milano, Italy
| | - Laura Mauri
- Department of Medical Biotechnology and Translational Medicine, University of Milan, Milano, Italy
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Mojumdar EH, Groen D, Gooris GS, Barlow DJ, Lawrence MJ, Deme B, Bouwstra JA. Localization of cholesterol and fatty acid in a model lipid membrane: a neutron diffraction approach. Biophys J 2014; 105:911-8. [PMID: 23972843 DOI: 10.1016/j.bpj.2013.07.003] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2013] [Revised: 06/17/2013] [Accepted: 07/01/2013] [Indexed: 12/18/2022] Open
Abstract
The intercellular lipid matrix of the skin's stratum corneum serves to protect the body against desiccation and simultaneously limits the passage of drugs and other xenobiotics into the body. The matrix is made up of ceramides, free fatty acids, and cholesterol, which are organized as two coexisting crystalline lamellar phases. In studies reported here, we sought to use the technique of neutron diffraction, together with the device of isotopic (H/D) substitution, to determine the molecular architecture of the lamellar phase having a repeat distance of 53.9 ± 0.3 Å. Using hydrogenous samples as well as samples incorporating perdeuterated (C24:0) fatty acids and selectively deuterated cholesterol, the diffraction data obtained were used to construct neutron scattering length density profiles. By this means, the locations within the unit cell were determined for the cholesterol and fatty acids. The cholesterol headgroup was found to lie slightly inward from the unit cell boundary and the tail of the molecule located 6.2 ± 0.2 Å from the unit cell center. The fatty acid headgroups were located at the unit cell boundary with their acyl chains straddling the unit cell center. Based on these results, a molecular model is proposed for the arrangement of the lipids within the unit cell.
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Affiliation(s)
- E H Mojumdar
- Department of Drug Delivery Technology, University of Leiden, Leiden, the Netherlands
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23
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Kiselev MA, Ermakova EV, Gruzinov AY, Zabelin AV. Formation of the long-periodicity phase in model membranes of the outermost layer of skin (Stratum corneum). CRYSTALLOGR REP+ 2014. [DOI: 10.1134/s106377451306014x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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24
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Ochalek M, Heissler S, Wohlrab J, Neubert R. Characterization of lipid model membranes designed for studying impact of ceramide species on drug diffusion and penetration. Eur J Pharm Biopharm 2012; 81:113-20. [DOI: 10.1016/j.ejpb.2012.02.002] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2011] [Revised: 12/16/2011] [Accepted: 02/06/2012] [Indexed: 11/28/2022]
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25
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Engelbrecht TN, Schroeter A, Hauß T, Neubert RH. Lipophilic penetration enhancers and their impact to the bilayer structure of stratum corneum lipid model membranes: Neutron diffraction studies based on the example Oleic Acid. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2011; 1808:2798-806. [DOI: 10.1016/j.bbamem.2011.08.012] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2011] [Revised: 07/29/2011] [Accepted: 08/09/2011] [Indexed: 10/17/2022]
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26
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Gangliosides and the multiscale modulation of membrane structure. Chem Phys Lipids 2011; 164:796-810. [DOI: 10.1016/j.chemphyslip.2011.09.005] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2011] [Revised: 09/12/2011] [Accepted: 09/13/2011] [Indexed: 02/07/2023]
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27
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Groen D, Gooris GS, Barlow DJ, Lawrence MJ, van Mechelen JB, Demé B, Bouwstra JA. Disposition of ceramide in model lipid membranes determined by neutron diffraction. Biophys J 2011; 100:1481-9. [PMID: 21402030 DOI: 10.1016/j.bpj.2011.02.001] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2010] [Revised: 02/01/2011] [Accepted: 02/01/2011] [Indexed: 10/18/2022] Open
Abstract
The lipid matrix present in the uppermost layer of the skin, the stratum corneum, plays a crucial role in the skin barrier function. The lipids are organized into two lamellar phases. To gain more insight into the molecular organization of one of these lamellar phases, we performed neutron diffraction studies. In the diffraction pattern, five diffraction orders were observed attributed to a lamellar phase with a repeat distance of 5.4 nm. Using contrast variation, the scattering length density profile could be calculated showing a typical bilayer arrangement. To obtain information on the arrangement of ceramides in the unit cell, a mixture that included a partly deuterated ceramide was also examined. The scattering length density profile of the 5.4-nm phase containing this deuterated ceramide demonstrated a symmetric arrangement of the ceramides with interdigitating acyl chains in the center of the unit cell.
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Affiliation(s)
- D Groen
- Leiden/Amsterdam Center for Drug Research, Department of Drug Delivery Technology, Gorlaeus Laboratories, University of Leiden, Leiden, The Netherlands
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28
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Sonnino S, Prinetti A. Lipids and membrane lateral organization. Front Physiol 2010; 1:153. [PMID: 21423393 PMCID: PMC3059948 DOI: 10.3389/fphys.2010.00153] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2010] [Accepted: 10/28/2010] [Indexed: 01/08/2023] Open
Abstract
Shortly after the elucidation of the very basic structure and properties of cellular membranes, it became evident that cellular membranes are highly organized structures with multiple and multi-dimensional levels of order. Very early observations suggested that the lipid components of biological membranes might be active players in the creation of these levels of order. In the late 1980s, several different and diverse experimental pieces of evidence coalesced together giving rise to the lipid raft hypothesis. Lipid rafts became enormously (and, in the opinion of these authors, sometimes acritically) popular, surprisingly not just within the lipidologist community (who is supposed to be naturally sensitive to the fascination of lipid rafts). Today, a PubMed search using the key word "lipid rafts" returned a list of 3767 papers, including 690 reviews (as a term of comparison, searching over the same time span for a very hot lipid-related key word, "ceramide" returned 6187 hits with 799 reviews), and a tremendous number of different cellular functions have been described as "lipid raft-dependent." However, a clear consensus definition of lipid raft has been proposed only in recent times, and the basic properties, the ruling forces, and even the existence of lipid rafts in living cells has been recently matter of intense debate. The scenario that is gradually emerging from the controversies elicited by the lipid raft hypothesis emphasizes multiple roles for membrane lipids in determining membrane order, that encompass their tendency to phase separation but are clearly not limited to this. In this review, we would like to re-focus the attention of the readers on the importance of lipids in organizing the fine structure of cellular membranes.
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Affiliation(s)
- Sandro Sonnino
- Department of Medical Chemistry, Biochemistry and Biotechnology, University of MilanoMilano, Italy
| | - Alessandro Prinetti
- Department of Medical Chemistry, Biochemistry and Biotechnology, University of MilanoMilano, Italy
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29
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Kiselev MA, Ermakova EV, Ryabova NY, Nayda OV, Zabelin AV, Pogorely DK, Korneev VN, Balagurov AM. Structural studies of the lipid membranes at the Siberia-2 synchrotron radiation source. CRYSTALLOGR REP+ 2010. [DOI: 10.1134/s106377451003017x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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30
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Ryabova NY, Kiselev MA, Balagurov AM. Transition processes in stratum corneum model lipid membranes with a mixture of free fatty acids. Biophysics (Nagoya-shi) 2010. [DOI: 10.1134/s000635090905008x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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31
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Investigation of stratum corneum lipid model membranes with free fatty acid composition by neutron diffraction. EUROPEAN BIOPHYSICS JOURNAL: EBJ 2009; 39:1167-76. [DOI: 10.1007/s00249-009-0569-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2009] [Revised: 11/20/2009] [Accepted: 11/24/2009] [Indexed: 10/20/2022]
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32
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Schröter A, Kessner D, Kiselev MA, Hauss T, Dante S, Neubert RHH. Basic nanostructure of stratum corneum lipid matrices based on ceramides [EOS] and [AP]: a neutron diffraction study. Biophys J 2009; 97:1104-14. [PMID: 19686658 DOI: 10.1016/j.bpj.2009.05.041] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2008] [Revised: 05/25/2009] [Accepted: 05/28/2009] [Indexed: 02/01/2023] Open
Abstract
The goal of this study was to investigate the nanostructure of SC lipid model membranes comprising the most relevant SC lipids such as the unique-structured omega-acylceramide [EOS] in a near natural ratio with neutron diffraction. In models proposed recently the presence of ceramide [EOS] and FFA are necessary for the formation of one of the two existent crystalline lamellar phases of the SC lipids, the long-periodicity phase as well as for the normal barrier function of the SC. The focus of this study was placed on the influence of the FFA BA on the membrane structure and its localization within the membrane based on the ceramides [EOS] and [AP]. The internal nanostructure of such membranes was obtained by Fourier synthesis from the experimental diffraction patterns. The resulting neutron scattering length density profiles showed that the exceptionally long ceramide [EOS] is arranged in a short-periodicity phase created by ceramide [AP] by spanning through the whole bilayer and extending even further into the adjacent bilayer. Specifically deuterated BA allowed us to determine the exact position of this FFA inside this SC lipid model membrane. Furthermore, hydration experiments showed that the presented SC mimic system shows an extremely small intermembrane hydration of approximately 1 A, consequently the headgroups of the neighboring leaflets are positioned close to each other.
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Affiliation(s)
- Annett Schröter
- Martin Luther Universität Halle-Wittenberg, Institute of Pharmacy, Halle (Saale), Germany.
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33
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Evidence of free fatty acid interdigitation in stratum corneum model membranes based on ceramide [AP] by deuterium labelling. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2009; 1788:2194-203. [DOI: 10.1016/j.bbamem.2009.07.024] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2008] [Revised: 07/24/2009] [Accepted: 07/28/2009] [Indexed: 11/30/2022]
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34
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Prinetti A, Loberto N, Chigorno V, Sonnino S. Glycosphingolipid behaviour in complex membranes. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2009; 1788:184-93. [DOI: 10.1016/j.bbamem.2008.09.001] [Citation(s) in RCA: 96] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2008] [Revised: 09/02/2008] [Accepted: 09/03/2008] [Indexed: 12/12/2022]
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35
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Role of very long fatty acid-containing glycosphingolipids in membrane organization and cell signaling: the model of lactosylceramide in neutrophils. Glycoconj J 2008; 26:615-21. [PMID: 19015977 DOI: 10.1007/s10719-008-9215-8] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2008] [Revised: 09/12/2008] [Accepted: 10/28/2008] [Indexed: 12/16/2022]
Abstract
Glycosphingolipids are highly enriched in specialized membrane microdomains ("lipid rafts", caveolar domains and glycosynapses), and they participate to the process of transduction of information across the membrane. Lactosylceramide (LacCer) is specifically coupled with the Src family kinase Lyn in plasma membrane microdomains of human neutrophils. Ligand binding to LacCer activates Lyn, resulting in neutrophil functions, such as superoxide generation and migration. The beta-Gal-(1-4)-beta-Glc disaccharide structure of LacCer is necessary, but it is not sufficient for LacCer-mediated Lyn activation. For this function, the presence of a LacCer molecular species with ceramide containing a very long fatty acid chain is also required. In this manuscript, we discuss the importance of interdigitation within the membrane, promoted by the presence of glycosphingolipid species with very long fatty acyl chains as determinants for membrane organization, instrumental to the signaling process.
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36
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Goñi FM, Alonso A. Effects of ceramide and other simple sphingolipids on membrane lateral structure. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2008; 1788:169-77. [PMID: 18848519 DOI: 10.1016/j.bbamem.2008.09.002] [Citation(s) in RCA: 167] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/30/2008] [Revised: 09/09/2008] [Accepted: 09/10/2008] [Indexed: 10/21/2022]
Abstract
The available data concerning the ability of ceramide and other simple sphingolipids to segregate laterally into rigid, gel-like domains in a fluid bilayer has been reviewed. Ceramides give rise to rigid ceramide-enriched domains when their N-acyl chain is longer than C12. The high melting temperature of hydrated ceramides, revealing a tight intermolecular interaction, is probably responsible for their lateral segregation. Ceramides compete with cholesterol for the formation of domains with lipids such as sphingomyelin or saturated phosphatidylcholines; under these conditions displacement of cholesterol by ceramide involves a transition from a liquid-ordered to a gel-like phase in the domains involved. When ceramide is generated in situ by a sphingomyelinase, instead of being premixed with the other lipids, gel-like domain formation occurs as well, although the topology of the domains may not be the same, the enzyme causing clustering of domains that is not detected with premixed ceramide. Ceramide-1-phosphate is not likely to form domains in fluid bilayers, and the same is true of sphingosine and of sphingosine-1-phosphate. However, sphingosine does rigidify pre-existing gel domains in mixed bilayers.
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Affiliation(s)
- Félix M Goñi
- Unidad de Biofísica (Centro Mixto CSIC-UPV/EHU), Departamento de Bioquímica, Universidad del País Vasco, Bilbao, Spain.
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37
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Kessner D, Kiselev M, Dante S, Hauss T, Lersch P, Wartewig S, Neubert RHH. Arrangement of ceramide [EOS] in a stratum corneum lipid model matrix: new aspects revealed by neutron diffraction studies. EUROPEAN BIOPHYSICS JOURNAL: EBJ 2008; 37:989-99. [PMID: 18427800 DOI: 10.1007/s00249-008-0328-6] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2007] [Revised: 03/31/2008] [Accepted: 04/02/2008] [Indexed: 11/30/2022]
Abstract
The lipid matrix in stratum corneum (SC) plays a key role in the barrier function of the mammalian skin. The major lipids are ceramides (CER), cholesterol (CHOL) and free fatty acids (FFA). Especially the unique-structured omega-acylceramide CER[EOS] is regarded to be essential for skin barrier properties by inducing the formation of a long-periodicity phase of 130 angstroms (LPP). In the present study, the arrangement of CER[EOS], either mixed with CER[AP] and CHOL or with CER[AP], CHOL and palmitic acid (PA), inside a SC lipid model membrane has been studied for the first time by neutron diffraction. For a mixed CER[EOS]/CER[AP]/CHOL membrane in a partly dehydrated state, the internal membrane nanostructure, i.e. the neutron scattering length density profile in the direction normal to the surface, was obtained by Fourier synthesis from the experimental diffraction patterns. The membrane repeat distance is equal to that of the formerly used SC lipid model system composed of CER[AP]/CHOL/PA/ChS. By comparing both the neutron scattering length density profiles, a possible arrangement of synthetic long-chain CER[EOS] molecules inside a SC lipid model matrix is suggested. The analysis of the internal membrane nanostructure implies that one CER[EOS] molecule penetrates from one membrane layer into an adjacent layer. A 130 angstroms periodicity phase could not be observed under experimental conditions, either in CER/CHOL mixtures or in CER/CHOL/FFA mixture. CER[EOS] can be arranged inside a phase with a repeat unit of 45.2 angstroms which is predominately formed by short-chain CER[AP] with distinct polarity.
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Affiliation(s)
- Doreen Kessner
- Institute of Pharmacy, Martin Luther University Halle/Wittenberg, Wolfgang-Langenbeck-Strabe 4, 06120, Halle Saale, Germany
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