1
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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.
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Affiliation(s)
- Lars Norlén
- Department of Cellular and Molecular Biology (CMB), Karolinska Institutet, Biomedicum, SE-171 77 Stockholm, Sweden.
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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: 5] [Impact Index Per Article: 5.0] [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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Wennberg C, Lundborg M, Lindahl E, Norlén L. Understanding Drug Skin Permeation Enhancers Using Molecular Dynamics Simulations. J Chem Inf Model 2023; 63:4900-4911. [PMID: 37462219 PMCID: PMC10428223 DOI: 10.1021/acs.jcim.3c00625] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2023] [Indexed: 08/15/2023]
Abstract
Our skin constitutes an effective permeability barrier that protects the body from exogenous substances but concomitantly severely limits the number of pharmaceutical drugs that can be delivered transdermally. In topical formulation design, chemical permeation enhancers (PEs) are used to increase drug skin permeability. In vitro skin permeability experiments can measure net effects of PEs on transdermal drug transport, but they cannot explain the molecular mechanisms of interactions between drugs, permeation enhancers, and skin structure, which limits the possibility to rationally design better new drug formulations. Here we investigate the effect of the PEs water, lauric acid, geraniol, stearic acid, thymol, ethanol, oleic acid, and eucalyptol on the transdermal transport of metronidazole, caffeine, and naproxen. We use atomistic molecular dynamics (MD) simulations in combination with developed molecular models to calculate the free energy difference between 11 PE-containing formulations and the skin's barrier structure. We then utilize the results to calculate the final concentration of PEs in skin. We obtain an RMSE of 0.58 log units for calculated partition coefficients from water into the barrier structure. We then use the modified PE-containing barrier structure to calculate the PEs' permeability enhancement ratios (ERs) on transdermal metronidazole, caffeine, and naproxen transport and compare with the results obtained from in vitro experiments. We show that MD simulations are able to reproduce rankings based on ERs. However, strict quantitative correlation with experimental data needs further refinement, which is complicated by significant deviations between different measurements. Finally, we propose a model for how to use calculations of the potential of mean force of drugs across the skin's barrier structure in a topical formulation design.
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Affiliation(s)
| | - Magnus Lundborg
- Science
for Life Laboratory, ERCO Pharma AB, 171 65 Solna, Sweden
| | - Erik Lindahl
- Department
of Biophysics and Biochemistry, Stockholm
University, 106 91 Stockholm, Sweden
- Department
of Applied Physics, Swedish e-Science Research Center, KTH Royal Institute of Technology, 106 91 Stockholm, Sweden
| | - Lars Norlén
- Department
of Cell and Molecular Biology (CMB), Karolinska
Institutet, 171 77 Solna, Sweden
- Dermatology
Clinic. Karolinska University Hospital, 171 77 Solna, Sweden
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4
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Wang J, Nitsche JM, Kasting GB, Wittum G, Nägel A. Transdermal and lateral effective diffusivities for drug transport in stratum corneum from a microscopic anisotropic diffusion model. Eur J Pharm Biopharm 2023:S0939-6411(23)00032-2. [PMID: 36764498 DOI: 10.1016/j.ejpb.2023.01.025] [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: 12/22/2021] [Revised: 10/10/2022] [Accepted: 01/27/2023] [Indexed: 02/11/2023]
Abstract
This paper presents a computational model of molecular diffusion through the interfollicular stratum corneum. Specifically, it extends an earlier two-dimensional microscopic model for the permeability in two ways: (1) a microporous leakage pathway through the intercellular lipid lamellae allows slow permeation of highly hydrophilic permeants through the tissue; and (2) the model yields explicit predictions of both lateral (D‾‖sc) and transdermal (D‾⊥sc) effective (average, homogenized) diffusivities of solutes within the tissue. We present here the mathematical framework for the analysis and a comparison of the predictions with experimental data on desorption of both hydrophilic and lipophilic solutes from human stratum corneum in vitro. Diffusion in the lipid lamellae is found to make the effective diffusivity highly anisotropic, with the predicted ratio D‾‖sc/D‾⊥sc ranging from 34-39 for fully hydrated skin and 150 to more than 1000 for partially hydrated skin. The diffusivities and their ratio are in accord with both experimental data and the results of mathematical analyses performed by others.
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Affiliation(s)
- Junxi Wang
- Goethe Center for Scientific Computing, Kettenhofweg 139, Goethe University, 60325 Frankfurt a.M., Germany
| | - Johannes M Nitsche
- Department of Chemical and Biological Engineering, University at Buffalo, The State University of New York, Buffalo, NY 14260-4200, USA
| | - Gerald B Kasting
- James L. Winkle College of Pharmacy, University of Cincinnati Academic Health Center, Cincinnati, OH 45267-0514, USA
| | - Gabriel Wittum
- Goethe Center for Scientific Computing, Kettenhofweg 139, Goethe University, 60325 Frankfurt a.M., Germany; King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi-Arabia
| | - Arne Nägel
- Goethe Center for Scientific Computing, Kettenhofweg 139, Goethe University, 60325 Frankfurt a.M., Germany.
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5
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Roy S, Ho JCS, Teo DLC, Gupta S, Nallani M. Biomimetic Stratum Corneum Liposome Models: Lamellar Organization and Permeability Studies. MEMBRANES 2023; 13:135. [PMID: 36837639 PMCID: PMC9962386 DOI: 10.3390/membranes13020135] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Revised: 01/18/2023] [Accepted: 01/18/2023] [Indexed: 06/18/2023]
Abstract
The stratum corneum (SC), the outer layer of the skin, plays a crucial role as a barrier protecting the underlying cells from external stress. The SC comprises three key components: ceramide (CER), free fatty acid (FFA), and cholesterol, along with small fractions of cholesterol sulfate and cholesterol ester. In order to gain a deeper understanding about the interdependence of the two major components, CER and FFA, on the organizational, structural, and functional properties of the SC layer, a library of SC lipid liposome (SCLL) models was developed by mixing CER (phytosphingosine or sphingosine), FFA (oleic acid, palmitic acid, or stearic acid), cholesterol, and cholesterol sulfate. Self-assembly of the SC lipids into lamellar phases was first confirmed by small-angle X-ray scattering. Short periodicity and long periodicity phases were identified for SCLLs containing phytosphingosines and sphingosine CERs, respectively. Furthermore, unsaturation in the CER acyl and FFA chains reduced the lipid conformational ordering and packing density of the liposomal bilayer, which were measured by differential scanning calorimetry and Fourier transform infrared spectroscopy. The introduction of unsaturation in the CER and/or FFA chains also impacted the lamellar integrity and permeability. This extensive library of SCLL models exhibiting physiologically relevant lamellar phases with defined structural and functional properties may potentially be used as a model system for screening pharmaceuticals or cosmetic agents.
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Affiliation(s)
- Susmita Roy
- Center for Biomimetic Sensor Science, School of Materials Science and Engineering, Nanyang Technological University, Singapore 637553, Singapore
| | - James C. S. Ho
- Center for Biomimetic Sensor Science, School of Materials Science and Engineering, Nanyang Technological University, Singapore 637553, Singapore
| | - Douglas L. C. Teo
- Center for Biomimetic Sensor Science, School of Materials Science and Engineering, Nanyang Technological University, Singapore 637553, Singapore
| | - Shikhar Gupta
- Procter & Gamble International Operations SA SG Branch, Singapore 138547, Singapore
| | - Madhavan Nallani
- Center for Biomimetic Sensor Science, School of Materials Science and Engineering, Nanyang Technological University, Singapore 637553, Singapore
- ACM Biolabs Pte Ltd., Singapore 638075, Singapore
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6
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Lundborg M, Wennberg C, Lidmar J, Hess B, Lindahl E, Norlén L. Skin permeability prediction with MD simulation sampling spatial and alchemical reaction coordinates. Biophys J 2022; 121:3837-3849. [PMID: 36104960 PMCID: PMC9674988 DOI: 10.1016/j.bpj.2022.09.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Revised: 06/22/2022] [Accepted: 09/08/2022] [Indexed: 11/02/2022] Open
Abstract
A molecular-level understanding of skin permeation may rationalize and streamline product development, and improve quality and control, of transdermal and topical drug delivery systems. It may also facilitate toxicity and safety assessment of cosmetics and skin care products. Here, we present new molecular dynamics simulation approaches that make it possible to efficiently sample the free energy and local diffusion coefficient across the skin's barrier structure to predict skin permeability and the effects of chemical penetration enhancers. In particular, we introduce a new approach to use two-dimensional reaction coordinates in the accelerated weight histogram method, where we combine sampling along spatial coordinates with an alchemical perturbation virtual coordinate. We present predicted properties for 20 permeants, and demonstrate how our approach improves correlation with ex vivo/in vitro skin permeation data. For the compounds included in this study, the obtained log KPexp-calc mean square difference was 0.9 cm2 h-2.
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Affiliation(s)
| | | | - Jack Lidmar
- Department of Physics, KTH Royal Institute of Technology, Stockholm, Sweden
| | - Berk Hess
- Department of Applied Physics, Science for Life Laboratory, KTH Royal Institute of Technology, Solna, Sweden
| | - Erik Lindahl
- Department of Biophysics and Biochemistry, Science for Life Laboratory, Stockholm University, Solna, Sweden; Department of Physics, Swedish e-Science Research Center, KTH Royal Institute of Technology, Stockholm, Sweden
| | - Lars Norlén
- Department of Cell and Molecular Biology (CMB), Karolinska Institutet, Stockholm, Sweden; Dermatology Clinic, Karolinska University Hospital, Stockholm, Sweden.
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7
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Miller C, Crampin E, Osborne JM. Multiscale modelling of desquamation in the interfollicular epidermis. PLoS Comput Biol 2022; 18:e1010368. [PMID: 36037236 PMCID: PMC9462764 DOI: 10.1371/journal.pcbi.1010368] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Revised: 09/09/2022] [Accepted: 07/08/2022] [Indexed: 11/19/2022] Open
Abstract
Maintenance of epidermal thickness is critical to the barrier function of the skin. Decreased tissue thickness, specifically in the stratum corneum (the outermost layer of the tissue), causes discomfort and inflammation, and is related to several severe diseases of the tissue. In order to maintain both stratum corneum thickness and overall tissue thickness it is necessary for the system to balance cell proliferation and cell loss. Cell proliferation in the epidermis occurs in the basal layer and causes constant upwards movement in the tissue. Cell loss occurs when dead cells at the top of the tissue are lost to the environment through a process called desquamation. Desquamation is thought to occur through a gradual reduction in adhesion between cells, due to the cleaving of adhesion proteins by enzymes, in the stratum corneum.
In this paper we will investigate combining a (mass action) subcellular model of desquamation with a three dimensional (cell centre based) multicellular model of the interfollicular epidermis to better understand maintenance of epidermal thickness. Specifically, our aim is to determine if a hypothesised biological model for the degradation of cell-cell adhesion, from the literature, is sufficient to maintain a steady state tissue thickness. These investigations show the model is able to provide a consistent rate of cell loss in the multicellular model. This loss balances proliferation, and hence maintains a homeostatic tissue thickness. Moreover, we find that multiple proliferative cell populations in the basal layer can be represented by a single proliferative cell population, simplifying investigations with this model.
The model is used to investigate a disorder (Netherton Syndrome) which disrupts desquamation. The model shows how biochemical changes can cause disruptions to the tissue, resulting in a reduced tissue thickness and consequently diminishing the protective role of the tissue. A hypothetical treatment result is also investigated: we compare the cases of a partially effective homogeneous treatment (where all cells partially recover) and a totally effective heterogeneous treatment (in which a proportion of the cells totally recover) with the aim to determine the difference in the response of the tissue to these different scenarios. Results show an increased benefit to corneum thickness from the heterogeneous treatment over the homogeneous treatment.
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Affiliation(s)
- Claire Miller
- School of Mathematics and Statistics, The University of Melbourne, Parkville, Australia
- Systems Biology Laboratory, School of Mathematics and Statistics, and Department of Biomedical Engineering, The University of Melbourne, Parkville, Australia
- Computational Science Lab, Informatics Institute, University of Amsterdam, Amsterdam, Netherlands
| | - Edmund Crampin
- Systems Biology Laboratory, School of Mathematics and Statistics, and Department of Biomedical Engineering, The University of Melbourne, Parkville, Australia
- School of Medicine, Faculty of Medicine, Dentistry and Health Sciences, The University of Melbourne, Parkville, Australia
- ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, Melbourne School of Engineering, The University of Melbourne, Parkville, Australia
| | - James M. Osborne
- School of Mathematics and Statistics, The University of Melbourne, Parkville, Australia
- * E-mail:
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8
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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: 78] [Impact Index Per Article: 26.0] [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.
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9
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Narangifard A, Wennberg CL, den Hollander L, Iwai I, Han H, Lundborg M, Masich S, Lindahl E, Daneholt B, Norlén L. Molecular Reorganization during the Formation of the Human Skin Barrier Studied In Situ. J Invest Dermatol 2021; 141:1243-1253.e6. [DOI: 10.1016/j.jid.2020.07.040] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Revised: 07/01/2020] [Accepted: 07/13/2020] [Indexed: 12/25/2022]
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10
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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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11
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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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12
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Bartle EI, Rao TC, Beggs RR, Dean WF, Urner TM, Kowalczyk AP, Mattheyses AL. Protein exchange is reduced in calcium-independent epithelial junctions. J Cell Biol 2020; 219:151763. [PMID: 32399559 PMCID: PMC7265307 DOI: 10.1083/jcb.201906153] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2019] [Revised: 01/29/2020] [Accepted: 03/11/2020] [Indexed: 12/29/2022] Open
Abstract
Desmosomes are cell–cell junctions that provide mechanical integrity to epithelial and cardiac tissues. Desmosomes have two distinct adhesive states, calcium-dependent and hyperadhesive, which balance tissue plasticity and strength. A highly ordered array of cadherins in the adhesive interface is hypothesized to drive hyperadhesion, but how desmosome structure confers adhesive state is still elusive. We employed fluorescence polarization microscopy to show that cadherin order is not required for hyperadhesion induced by pharmacologic and genetic approaches. FRAP experiments in cells treated with the PKCα inhibitor Gö6976 revealed that cadherins, plakoglobin, and desmoplakin have significantly reduced exchange in and out of hyperadhesive desmosomes. To test whether this was a result of enhanced keratin association, we used the desmoplakin mutant S2849G, which conferred reduced protein exchange. We propose that inside-out regulation of protein exchange modulates adhesive function, whereby proteins are “locked in” to hyperadhesive desmosomes while protein exchange confers plasticity on calcium-dependent desmosomes, thereby providing rapid control of adhesion.
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Affiliation(s)
- Emily I Bartle
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL
| | - Tejeshwar C Rao
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL
| | - Reena R Beggs
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL
| | - William F Dean
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL
| | - Tara M Urner
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL
| | - Andrew P Kowalczyk
- Departments of Cell Biology and Dermatology, Emory University, Atlanta, GA
| | - Alexa L Mattheyses
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL
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13
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Antunes E, Cavaco-Paulo A. Stratum corneum lipid matrix with unusual packing: A molecular dynamics study. Colloids Surf B Biointerfaces 2020; 190:110928. [DOI: 10.1016/j.colsurfb.2020.110928] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2019] [Revised: 01/22/2020] [Accepted: 03/01/2020] [Indexed: 01/08/2023]
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14
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Yagi N, Aoyama K, Ohta N. Microbeam X-ray diffraction study of lipid structure in stratum corneum of human skin. PLoS One 2020; 15:e0233131. [PMID: 32392265 PMCID: PMC7213682 DOI: 10.1371/journal.pone.0233131] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2019] [Accepted: 04/28/2020] [Indexed: 11/18/2022] Open
Abstract
Human skin, not previously frozen, was studied by small-angle X-ray diffraction. The samples were folded so that a 6μm X-ray beam passed through the top layer of skin, stratum corneum. Diffraction patterns recorded with this method consisted of peaks at about q = 0.5, 1.0 and 1.4 nm-1 in the direction perpendicular to the skin surface more clearly than in previous studies. These peaks are interpreted to arise from lipids between corneocytes. A simple unit of a linear electron density profile with three minima was used to account for the observed intensity profiles. Combinations of calculated diffraction from models with one, two and three units accounted for the major part of the observed diffraction pattern, showing the diversity in the structure of the intercellular lipids.
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Affiliation(s)
- Naoto Yagi
- Japan Synchrotron Radiation Research Institute, SPring-8, Sayo, Hyogo, Japan
- * E-mail:
| | - Koki Aoyama
- Japan Synchrotron Radiation Research Institute, SPring-8, Sayo, Hyogo, Japan
| | - Noboru Ohta
- Japan Synchrotron Radiation Research Institute, SPring-8, Sayo, Hyogo, Japan
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15
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MacDermaid CM, Hall KW, DeVane RH, Klein ML, Fiorin G. Coexistence of Lipid Phases Stabilizes Interstitial Water in the Outer Layer of Mammalian Skin. Biophys J 2020; 118:1588-1601. [PMID: 32101711 DOI: 10.1016/j.bpj.2020.01.044] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2019] [Revised: 01/20/2020] [Accepted: 01/27/2020] [Indexed: 12/22/2022] Open
Abstract
The lipid matrix in the outer layer of mammalian skin, the stratum corneum, has been previously investigated by multiple biophysical techniques aimed at identifying hydrophilic and lipophilic pathways of permeation. Although consensus is developing over the microscopic structure of the lipid matrix, no molecular-resolution model describes the permeability of all chemical species simultaneously. Using molecular dynamics simulations of a model mixture of skin lipids, the self-assembly of the lipid matrix lamellae has been studied. At higher humidity, the resulting lamellar phase is maintained by partitioning excess water into isolated droplets of controlled size and spatial distribution. The droplets may fuse together to form intralamellar water channels, thereby providing a pathway for the permeation of hydrophilic species. These results reconcile competing data on the outer skin's structure and broaden the scope of molecular-based methods to improve the safety of topical products and to advance transdermal drug delivery.
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Affiliation(s)
- Christopher M MacDermaid
- Institute for Computational Molecular Science and Temple Materials Institute, Philadelphia, Pennsylvania
| | - Kyle Wm Hall
- Institute for Computational Molecular Science and Temple Materials Institute, Philadelphia, Pennsylvania
| | | | - Michael L Klein
- Institute for Computational Molecular Science and Temple Materials Institute, Philadelphia, Pennsylvania
| | - Giacomo Fiorin
- Institute for Computational Molecular Science and Temple Materials Institute, Philadelphia, Pennsylvania.
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16
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Zhou S, Hokugo A, McClendon M, Zhang Z, Bakshi R, Wang L, Segovia LA, Rezzadeh K, Stupp SI, Jarrahy R. Bioactive peptide amphiphile nanofiber gels enhance burn wound healing. Burns 2019; 45:1112-1121. [DOI: 10.1016/j.burns.2018.06.008] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2017] [Revised: 06/08/2018] [Accepted: 06/16/2018] [Indexed: 12/18/2022]
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17
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Nitsche LC, Kasting GB, Nitsche JM. Microscopic Models of Drug/Chemical Diffusion Through the Skin Barrier: Effects of Diffusional Anisotropy of the Intercellular Lipid. J Pharm Sci 2019; 108:1692-1712. [DOI: 10.1016/j.xphs.2018.11.014] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2018] [Revised: 11/07/2018] [Accepted: 11/08/2018] [Indexed: 10/27/2022]
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18
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Yamamoto K, Klossek A, Fuchs K, Watts B, Raabe J, Flesch R, Rancan F, Pischon H, Radbruch M, Gruber AD, Mundhenk L, Vogt A, Blume-Peytavi U, Schrade P, Bachmann S, Gurny R, Rühl E. Soft X-ray microscopy for probing of topical tacrolimus delivery via micelles. Eur J Pharm Biopharm 2019; 139:68-75. [PMID: 30849430 DOI: 10.1016/j.ejpb.2019.03.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2018] [Revised: 01/04/2019] [Accepted: 03/04/2019] [Indexed: 12/27/2022]
Abstract
The penetration of topically applied tacrolimus formulated in micelles into murine skin is reported, measured by X-ray microscopy. Tacrolimus and micelles are probed for the first time by this high spatial resolution technique by element-selective excitation in the C 1s- and O 1s-regimes. This method allows selective detection of the distribution and penetration depth of drugs and carrier molecules into biologic tissues. It is observed that small, but distinct quantities of the drug and micelles, acting as a drug carrier, penetrate the stratum corneum. A comparison is made with the paraffin-based commercial tacrolimus ointment Protopic®, where local drug concentrations show to be low. A slight increase in local drug concentration in the stratum corneum is observed, if tacrolimus is formulated in micelles, as compared to Protopic®. This underscores the importance of the drug formulations for effective drug delivery. Time-resolved penetration shows presence of drug in the stratum corneum 100 min after formulation application, with penetration to deeper skin layers at 1000 min. High resolution micrographs give indications for a penetration pathway along the lipid membranes between corneocytes, but also suggest that the compound may penetrate corneocytes.
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Affiliation(s)
- K Yamamoto
- Physikalische Chemie, Freie Universität Berlin, Arnimallee 22, 14195 Berlin, Germany
| | - A Klossek
- Physikalische Chemie, Freie Universität Berlin, Arnimallee 22, 14195 Berlin, Germany
| | - K Fuchs
- Apidel SA, c/o The Business Harbour, 29 Quai du Mont Blanc, 1201 Geneva, Switzerland
| | - B Watts
- Swiss Light Source, Paul Scherrer Institut, Forschungsstraße 111, 5232 Villigen PSI, Switzerland
| | - J Raabe
- Swiss Light Source, Paul Scherrer Institut, Forschungsstraße 111, 5232 Villigen PSI, Switzerland
| | - R Flesch
- Physikalische Chemie, Freie Universität Berlin, Arnimallee 22, 14195 Berlin, Germany
| | - F Rancan
- Clinical Research Center for Hair and Skin Science, Department of Dermatology and Allergy, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, 10117 Berlin, Germany
| | - H Pischon
- Institute of Veterinary Pathology, Freie Universität Berlin, Robert-von-Ostertag-Str. 15, 14163 Berlin, Germany
| | - M Radbruch
- Institute of Veterinary Pathology, Freie Universität Berlin, Robert-von-Ostertag-Str. 15, 14163 Berlin, Germany
| | - A D Gruber
- Institute of Veterinary Pathology, Freie Universität Berlin, Robert-von-Ostertag-Str. 15, 14163 Berlin, Germany
| | - L Mundhenk
- Institute of Veterinary Pathology, Freie Universität Berlin, Robert-von-Ostertag-Str. 15, 14163 Berlin, Germany
| | - A Vogt
- Clinical Research Center for Hair and Skin Science, Department of Dermatology and Allergy, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, 10117 Berlin, Germany
| | - U Blume-Peytavi
- Clinical Research Center for Hair and Skin Science, Department of Dermatology and Allergy, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, 10117 Berlin, Germany
| | - P Schrade
- Abteilung für Elektronenmikroskopie at CVK, 13353 Berlin, Germany
| | - S Bachmann
- Abteilung für Elektronenmikroskopie at CVK, 13353 Berlin, Germany
| | - R Gurny
- Apidel SA, c/o The Business Harbour, 29 Quai du Mont Blanc, 1201 Geneva, Switzerland
| | - E Rühl
- Physikalische Chemie, Freie Universität Berlin, Arnimallee 22, 14195 Berlin, Germany
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19
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Chiba T, Nakahara T, Kohda F, Ichiki T, Manabe M, Furue M. Measurement of trihydroxy-linoleic acids in stratum corneum by tape-stripping: Possible biomarker of barrier function in atopic dermatitis. PLoS One 2019; 14:e0210013. [PMID: 30608955 PMCID: PMC6319710 DOI: 10.1371/journal.pone.0210013] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2018] [Accepted: 12/14/2018] [Indexed: 12/19/2022] Open
Abstract
Epidermal ceramides are indispensable lipids that maintain the functions of the stratum corneum. Esterified omega-hydroxyacyl-sphingosine (EOS) ceramide with a linoleate moiety is one of the most important ceramide species for forming cornified lipid envelopes. This linoleate moiety is eventually metabolized to trihydroxy-linoleic acid (triol, 9,10,13-trihydroxy-11E-octadecenoic acid). Thus, we assumed that a decrease of triols might reflect skin barrier dysfunction. Against this background, the purposes of this study were to measure the triols by a simple tape-stripping method and to determine the correlation between the amount of triols and transepidermal water loss (TEWL) as an indicator of barrier dysfunction in atopic dermatitis patients. Twenty Japanese subjects with normal skin and 20 atopic dermatitis patients were enrolled in this study. TEWL was measured and triols of the stratum corneum were analyzed by tape-stripping. The results showed for the first time that triols in the stratum corneum could be simply measured using the tape-stripping method. The triol levels in atopic dermatitis patients were much higher than those in healthy subjects. Moreover, the triol levels correlated with TEWL of non-lesional forearm skin in patients with atopic dermatitis. The results suggest that the assaying of triol levels via non-invasive tape-stripping could be beneficial for monitoring barrier function in atopic dermatitis.
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Affiliation(s)
- Takahito Chiba
- Department of Dermatology and Plastic Surgery, Akita University Graduate School of Medicine, Akita, Japan
- * E-mail:
| | - Takeshi Nakahara
- Department of Dermatology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Futoshi Kohda
- Department of Dermatology, Aso Iizuka Hospital, Fukuoka, Japan
| | - Toshio Ichiki
- Department of Dermatology, Aso Iizuka Hospital, Fukuoka, Japan
| | - Motomu Manabe
- Department of Dermatology and Plastic Surgery, Akita University Graduate School of Medicine, Akita, Japan
| | - Masutaka Furue
- Department of Dermatology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
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20
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Uchino T, Kato S, Hatta I, Miyazaki Y, Suzuki T, Sasaki K, Kagawa Y. Study on the drug permeation mechanism from flurbiprofen-loaded glyceryl monooleyl ether-based lyotropic liquid crystalline nanoparticles across the skin: Synchrotron X-ray diffraction and confocal laser scanning microscopy study. Int J Pharm 2019; 555:259-269. [DOI: 10.1016/j.ijpharm.2018.11.031] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2018] [Revised: 11/12/2018] [Accepted: 11/13/2018] [Indexed: 01/09/2023]
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21
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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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22
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Human skin barrier formation takes place via a cubic to lamellar lipid phase transition as analyzed by cryo-electron microscopy and EM-simulation. Exp Cell Res 2018; 366:139-151. [DOI: 10.1016/j.yexcr.2018.03.010] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2018] [Accepted: 03/06/2018] [Indexed: 01/14/2023]
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23
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Kováčik A, Vogel A, Adler J, Pullmannová P, Vávrová K, Huster D. Probing the role of ceramide hydroxylation in skin barrier lipid models by 2H solid-state NMR spectroscopy and X-ray powder diffraction. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2018; 1860:1162-1170. [PMID: 29408487 DOI: 10.1016/j.bbamem.2018.02.003] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2017] [Revised: 01/30/2018] [Accepted: 02/01/2018] [Indexed: 10/18/2022]
Abstract
In this work, we studied model stratum corneum lipid mixtures composed of the hydroxylated skin ceramides N-lignoceroyl 6-hydroxysphingosine (Cer[NH]) and α-hydroxylignoceroyl phytosphingosine (Cer[AP]). Two model skin lipid mixtures of the composition Cer[NH] or Cer[AP], N-lignoceroyl sphingosine (Cer[NS]), lignoceric acid (C24:0) and cholesterol in a 0.5:0.5:1:1 molar ratio were compared. Model membranes were investigated by differential scanning calorimetry and 2H solid-state NMR spectroscopy at temperatures from 25 °C to 80 °C. Each component of the model mixture was specifically deuterated for selective detection by 2H NMR. Thus, the exact phase composition of the mixture at varying temperatures could be quantified. Moreover, using X-ray powder diffraction we investigated the lamellar phase formation. From the solid-state NMR and DSC studies, we found that both hydroxylated Cer[NH] and Cer[AP] exhibit a similar phase behavior. At physiological skin temperature of 32 °C, the lipids form a crystalline (orthorhombic) phase. With increasing temperature, most of the lipids become fluid and form a liquid-crystalline phase, which converts to the isotropic phase at higher temperatures (65-80 °C). Interestingly, lignoceric acid in the Cer[NH]-containing mixture has a tendency to form two types of fluid phases at 65 °C. This tendency was also observed in Cer[AP]-containing membranes at 80 °C. While Cer[AP]-containing lipid models formed a short periodicity phase featuring a repeat spacing of d = 5.4 nm, in the Cer[NH]-based model skin lipid membranes, the formation of unusual long periodicity phase with a repeat spacing of d = 10.7 nm was observed.
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Affiliation(s)
- Andrej Kováčik
- Institute for Medical Physics and Biophysics, Leipzig University, Härtelstrasse 16-18, 04107 Leipzig, Germany; Skin Barrier Research Group, Faculty of Pharmacy in Hradec Králové, Charles University, Akademika Heyrovského 1203, 50005 Hradec Králové, Czech Republic
| | - Alexander Vogel
- Institute for Medical Physics and Biophysics, Leipzig University, Härtelstrasse 16-18, 04107 Leipzig, Germany
| | - Juliane Adler
- Institute for Medical Physics and Biophysics, Leipzig University, Härtelstrasse 16-18, 04107 Leipzig, Germany
| | - Petra Pullmannová
- Skin Barrier Research Group, Faculty of Pharmacy in Hradec Králové, Charles University, Akademika Heyrovského 1203, 50005 Hradec Králové, Czech Republic
| | - Kateřina Vávrová
- Skin Barrier Research Group, Faculty of Pharmacy in Hradec Králové, Charles University, Akademika Heyrovského 1203, 50005 Hradec Králové, Czech Republic.
| | - Daniel Huster
- Institute for Medical Physics and Biophysics, Leipzig University, Härtelstrasse 16-18, 04107 Leipzig, Germany.
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24
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Olsztyńska-Janus S, Pietruszka A, Kiełbowicz Z, Czarnecki MA. ATR-IR study of skin components: Lipids, proteins and water. Part I: Temperature effect. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2018; 188:37-49. [PMID: 28689077 DOI: 10.1016/j.saa.2017.07.001] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2017] [Revised: 06/30/2017] [Accepted: 07/01/2017] [Indexed: 06/07/2023]
Abstract
In this work we report the studies of the effect of temperature on skin components, such as lipids, proteins and water. Modifications of lipids structure induced by increasing temperature (from 20 to 90°C) have been studied using ATR-IR (Attenuated Total Reflectance Infrared) spectroscopy, which is a powerful tool for characterization of the molecular structure and properties of tissues, such as skin. Due to the small depth of penetration (0.6-5.6μm), ATR-IR spectroscopy probes only the outermost layer of the skin, i.e. the stratum corneum (SC). The assignment of main spectral features of skin components allows for the determination of phase transitions from the temperature dependencies of band intensities [e.g. νas(CH2) and νs(CH2)]. The phase transitions were determined by using two methods: the first one was based on the first derivative of the Boltzmann function and the second one employed tangent lines of sigmoidal, aforementioned dependencies. The phase transitions in lipids were correlated with modifications of the structure of water and proteins.
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Affiliation(s)
- S Olsztyńska-Janus
- Department of Biomedical Engineering, Wrocław University of Science and Technology, pl. Grunwaldzki 13, 50-370 Wrocław, Poland.
| | - A Pietruszka
- Department of Biomedical Engineering, Wrocław University of Science and Technology, pl. Grunwaldzki 13, 50-370 Wrocław, Poland
| | - Z Kiełbowicz
- Department of Surgery the Faculty of Veterinary Medicine, Wrocław University of Environmental and Life Sciences, pl. Grunwaldzki 51, 50-366 Wrocław, Poland
| | - M A Czarnecki
- Faculty of Chemistry, University of Wrocław, F. Joliot-Curie 14, 50-383 Wrocław, Poland
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25
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Bartle EI, Urner TM, Raju SS, Mattheyses AL. Desmoglein 3 Order and Dynamics in Desmosomes Determined by Fluorescence Polarization Microscopy. Biophys J 2018; 113:2519-2529. [PMID: 29212005 DOI: 10.1016/j.bpj.2017.09.028] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2017] [Revised: 09/18/2017] [Accepted: 09/21/2017] [Indexed: 11/24/2022] Open
Abstract
Desmosomes are macromolecular cell-cell junctions that provide adhesive strength in epithelial tissue. Desmosome function is inseparably linked to structure, and it is hypothesized that the arrangement, or order, of desmosomal cadherins in the intercellular space is critical for adhesive strength. However, due to desmosome size, molecular complexity, and dynamics, the role that order plays in adhesion is challenging to study. Herein, we present an excitation resolved fluorescence polarization microscopy approach to measure the spatiotemporal dynamics of order and disorder of the desmosomal cadherin desmoglein 3 (Dsg3) in living cells. Simulations were used to establish order factor as a robust metric for quantifying the spatiotemporal dynamics of order and disorder. Order factor measurements in keratinocytes showed the Dsg3 extracellular domain is ordered at the individual desmosome, single cell, and cell population levels compared to a series of disordered controls. Desmosomal adhesion is Ca2+ dependent, and reduction of extracellular Ca2+ leads to a loss of adhesion measured by dispase fragmentation assay (λ = 15.1 min). Live cell imaging revealed Dsg3 order decreased more rapidly (λ = 5.5 min), indicating that cadherin order is not required for adhesion. Our results suggest that rapid disordering of cadherins can communicate a change in extracellular Ca2+ concentration to the cell, leading to a downstream loss of adhesion. Fluorescence polarization is an effective bridge between protein structure and complex dynamics and the approach presented here is broadly applicable to studying order in macromolecular structures.
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Affiliation(s)
- Emily I Bartle
- Department of Cell Biology, Emory University, Atlanta, Georgia
| | - Tara M Urner
- Department of Cell Biology, Emory University, Atlanta, Georgia
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26
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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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27
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Kodiweera C, Romonchuk WJ, Yang Y, Bunge AL. Characterization of Water and a Model Lipophilic Compound in Human Stratum Corneum by NMR Spectroscopy and Equilibrium Sorption. J Pharm Sci 2016; 105:3376-3386. [PMID: 27671234 DOI: 10.1016/j.xphs.2016.08.010] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2016] [Revised: 07/14/2016] [Accepted: 08/12/2016] [Indexed: 11/27/2022]
Abstract
The stratum corneum (SC) is the outermost skin layer in humans and other mammals and the primary barrier to water loss and environmental exposure to chemicals and microorganisms. It consists of flattened, keratin-filled corneocytes surrounded by well-organized lipid layers. Human SC at varying degrees of hydration with and without addition of a model lipophilic compound, 2-(trifluoromethyl) benzonitrile (TFMB), was studied using proton (1H) and fluorine (19F) nuclear magnetic resonance techniques. Proton spectral analyses revealed that water mainly occupies the corneocytes in agreement with prior studies. Observations from 19F spectral and spin-lattice relaxation time (T1) analyses showed that TFMB is primarily present in the lipids with small amounts in water, which is located within the corneocytes. This is consistent with TFMB sorption, which was measured in SC with and without lipid extraction. The presence of TFMB within the corneocytes supports the hypothesis that transcellular diffusion of a lipophilic compound like TFMB may contribute to SC permeation.
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Affiliation(s)
- Chandana Kodiweera
- Chemical and Biological Engineering Department, Colorado School of Mines, Golden, Colorado 80401; Department of Psychological and Brain Sciences and Dartmouth Brain Imaging Center, Dartmouth College, Hanover, New Hampshire 03755
| | - Wayne J Romonchuk
- Chemical and Biological Engineering Department, Colorado School of Mines, Golden, Colorado 80401
| | - Yuan Yang
- Department of Chemistry, Colorado School of Mines, Golden, Colorado 80401
| | - Annette L Bunge
- Chemical and Biological Engineering Department, Colorado School of Mines, Golden, Colorado 80401.
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28
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Kitaoka M, Wakabayashi R, Kamiya N, Goto M. Solid-in-oil nanodispersions for transdermal drug delivery systems. Biotechnol J 2016; 11:1375-1385. [PMID: 27529824 PMCID: PMC5132072 DOI: 10.1002/biot.201600081] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2016] [Revised: 07/10/2016] [Accepted: 07/11/2016] [Indexed: 12/15/2022]
Abstract
Transdermal administration of drugs has advantages over conventional oral administration or administration using injection equipment. The route of administration reduces the opportunity for drug evacuation before systemic circulation, and enables long-lasting drug administration at a modest body concentration. In addition, the skin is an attractive route for vaccination, because there are many immune cells in the skin. Recently, solid-in-oil nanodisperison (S/O) technique has demonstrated to deliver cosmetic and pharmaceutical bioactives efficiently through the skin. S/O nanodispersions are nanosized drug carriers designed to overcome the skin barrier. This review discusses the rationale for preparation of efficient and stable S/O nanodispersions, as well as application examples in cosmetic and pharmaceutical materials including vaccines. Drug administration using a patch is user-friendly, and may improve patient compliance. The technique is a potent transcutaneous immunization method without needles.
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Affiliation(s)
- Momoko Kitaoka
- Graduate School of Engineering, Kyushu University, Fukuoka, Japan
| | - Rie Wakabayashi
- Graduate School of Engineering, Kyushu University, Fukuoka, Japan.,Center for Transdermal Drug Delivery, Kyushu University, Fukuoka, Japan
| | - Noriho Kamiya
- Graduate School of Engineering, Kyushu University, Fukuoka, Japan.,Center for Transdermal Drug Delivery, Kyushu University, Fukuoka, Japan.,Center for Future Chemistry, Kyushu University, Fukuoka, Japan
| | - Masahiro Goto
- Graduate School of Engineering, Kyushu University, Fukuoka, Japan.,Center for Transdermal Drug Delivery, Kyushu University, Fukuoka, Japan.,Center for Future Chemistry, Kyushu University, Fukuoka, Japan
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Das C, Olmsted PD. The physics of stratum corneum lipid membranes. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2016; 374:rsta.2015.0126. [PMID: 27298438 PMCID: PMC4920276 DOI: 10.1098/rsta.2015.0126] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 04/15/2016] [Indexed: 05/22/2023]
Abstract
The stratum corneum (SC), the outermost layer of skin, comprises rigid corneocytes (keratin-filled dead cells) in a specialized lipid matrix. The continuous lipid matrix provides the main barrier against uncontrolled water loss and invasion of external pathogens. Unlike all other biological lipid membranes (such as intracellular organelles and plasma membranes), molecules in the SC lipid matrix show small hydrophilic groups and large variability in the length of the alkyl tails and in the numbers and positions of groups that are capable of forming hydrogen bonds. Molecular simulations provide a route for systematically probing the effects of each of these differences separately. In this article, we present the results from atomistic molecular dynamics of selected lipid bilayers and multi-layers to probe the effect of these polydispersities. We address the nature of the tail packing in the gel-like phase, the hydrogen bond network among head groups, the bending moduli expected for leaflets comprising SC lipids and the conformation of very long ceramide lipids in multi-bilayer lipid assemblies.This article is part of the themed issue 'Soft interfacial materials: from fundamentals to formulation'.
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Affiliation(s)
- Chinmay Das
- School of Mathematics, University of Leeds, Leeds LS2 9JT, UK
| | - Peter D Olmsted
- Department of Physics and Institute for Soft Matter Synthesis and Metrology, Georgetown University, Washington, DC 20057, USA
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Chiba T, Thomas CP, Calcutt MW, Boeglin WE, O'Donnell VB, Brash AR. The Precise Structures and Stereochemistry of Trihydroxy-linoleates Esterified in Human and Porcine Epidermis and Their Significance in Skin Barrier Function: IMPLICATION OF AN EPOXIDE HYDROLASE IN THE TRANSFORMATIONS OF LINOLEATE. J Biol Chem 2016; 291:14540-54. [PMID: 27151221 PMCID: PMC4938176 DOI: 10.1074/jbc.m115.711267] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2015] [Indexed: 12/02/2022] Open
Abstract
Creation of an intact skin water barrier, a prerequisite for life on dry land,
requires the lipoxygenase-catalyzed oxidation of the essential fatty acid linoleate,
which is esterified to the ω-hydroxyl of an epidermis-specific ceramide.
Oxidation of the linoleate moiety by lipoxygenases is proposed to facilitate
enzymatic cleavage of the ester bond, releasing free ω-hydroxyceramide for
covalent binding to protein, thus forming the corneocyte lipid envelope, a key
component of the epidermal barrier. Herein, we report the transformations of
esterified linoleate proceed beyond the initial steps of oxidation and epoxyalcohol
synthesis catalyzed by the consecutive actions of 12R-LOX and
epidermal LOX3. The major end product in human and porcine epidermis is a trihydroxy
derivative, formed with a specificity that implicates participation of an epoxide
hydrolase in converting epoxyalcohol to triol. Of the 16 possible triols arising from
hydrolysis of 9,10-epoxy-13-hydroxy-octadecenoates, using LC-MS and chiral analyses,
we identify and quantify specifically
9R,10S,13R-trihydroxy-11E-octadecenoate
as the single major triol esterified in porcine epidermis and the same isomer with
lesser amounts of its 10R diastereomer in human epidermis. The
9R,10S,13R-triol is formed by
SN2 hydrolysis of the
9R,10R-epoxy-13R-hydroxy-octadecenoate
product of the LOX enzymes, a reaction specificity characteristic of epoxide
hydrolase. The high polarity of triol over the primary linoleate products enhances
the concept that the oxidations disrupt corneocyte membrane lipids, promoting release
of free ω-hydroxyceramide for covalent binding to protein and sealing of the
waterproof barrier.
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Affiliation(s)
| | - Christopher P Thomas
- the Systems Immunity Research Institute, School of Medicine, Cardiff University, Cardiff CF14 4XN, Wales, United Kingdom
| | - M Wade Calcutt
- Biochemistry and the Vanderbilt Institute of Chemical Biology, Vanderbilt University School of Medicine, Nashville, Tennessee 37232 and
| | | | - Valerie B O'Donnell
- the Systems Immunity Research Institute, School of Medicine, Cardiff University, Cardiff CF14 4XN, Wales, United Kingdom
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31
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Corneodesmosomal water content in frozen-hydrated porcine skin. J Invest Dermatol 2015; 135:1689-1691. [PMID: 25741993 DOI: 10.1038/jid.2015.31] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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32
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Norlén L. Update of technologies for examining the stratum corneum at the molecular level. Br J Dermatol 2014; 171 Suppl 3:13-8. [DOI: 10.1111/bjd.13280] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/09/2014] [Indexed: 11/28/2022]
Affiliation(s)
- L. Norlén
- Department of Cell and Molecular Biology; Karolinska Institutet, and Dermatology Clinic; Karolinska University Hospital; Stockholm Sweden
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33
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Doucet J, Potter A, Baltenneck C, Domanov YA. Micron-scale assessment of molecular lipid organization in human stratum corneum using microprobe X-ray diffraction. J Lipid Res 2014; 55:2380-8. [PMID: 25180243 DOI: 10.1194/jlr.m053389] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Lipid and protein components of the stratum corneum (SC) are organized in complex supramolecular arrangements. Exploring spatial relations between various possible substructures is important for understanding the barrier function of this uppermost layer of epidermis. Here, we report the first study where micro-focus X-ray scattering was used for assessing fine structural variations of the human skin barrier with micrometer resolution. We found that the scattering profiles were unchanged when scanning in the direction parallel to the SC surface. Furthermore, small-angle scattering profiles did not change as a function of depth in the SC, confirming that the lipid lamellar spacings remained the same throughout the SC. However, the wide-angle scattering data showed that the orthorhombic phase was more abundant in the middle layers of the SC, whereas the hexagonal phase dominated in the surface layers both at the external and the lowest part of the SC; i.e., the lipids were most tightly packed in the middle region of the SC. Taken together, our results demonstrate that microprobe X-ray diffraction provides abundant information about spatial variations of the SC lipid structure and thus may be a promising tool for assessing the effects of topical formulations on the barrier function of skin.
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Affiliation(s)
- Jean Doucet
- Laboratoire de Physique des Solides, Université Paris-Sud, Orsay, France Phi-Axis, Antony, France
| | - Anne Potter
- Skin Biophysics Laboratory, L'Oréal Research & Innovation, Aulnay-sous-Bois, France
| | - Carine Baltenneck
- Skin Biophysics Laboratory, L'Oréal Research & Innovation, Aulnay-sous-Bois, France
| | - Yegor A Domanov
- Skin Biophysics Laboratory, L'Oréal Research & Innovation, Aulnay-sous-Bois, France
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Comparative SAXS and DSC study on stratum corneum structural organization in an epidermal cell culture model (ROC): impact of cultivation time. Eur J Pharm Sci 2013; 50:577-85. [PMID: 23770376 DOI: 10.1016/j.ejps.2013.06.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2013] [Revised: 06/01/2013] [Accepted: 06/02/2013] [Indexed: 11/20/2022]
Abstract
Cell cultured skin equivalents present an alternative for dermatological in vitro evaluations of drugs and excipients as they provide the advantage of availability, lower variability and higher assay robustness compared to native skin. For penetration/permeation studies, an adequate stratum corneum barrier similar to that of human stratum corneum is, however, a prerequisite. In this study, the stratum corneum lipid organization in an epidermal cell culture model based on rat epidermal keratinocytes (REK organotypic culture, ROC) was investigated by small-angle X-ray scattering (SAXS) in dependence on ROC cultivation time and in comparison to native human and rat stratum cornea. In addition, the thermal phase behavior was studied by differential scanning calorimetry (DSC) and barrier properties were checked by measurements of the permeability of tritiated water. The development of the barrier of ROC SC obtained at different cultivation times (7, 14 and 21 days at the air-liquid interface) was connected with an increase in structural order of the SC lipids in SAXS measurements: Already cultivation for 14 days at the air-liquid interface resulted overall in a competent SC permeability barrier and SC lipid organization. Cultivation for 21 days resulted in further minor changes in the structural organization of ROC SC. The SAXS patterns of ROC SC had overall large similarities with that of human SC and point to the presence of a long periodicity phase with a repeat distance of about 122Å, e.g. slightly smaller than that determined for human SC in the present study (127Å). Moreover, SAXS results also indicate the presence of covalently bound ceramides, which are crucial for a proper SC barrier, although the corresponding thermal transitions were not clearly detectable by DSC. Due to the competent SC barrier properties and high structural and organizational similarity to that of native human SC, ROC presents a promising alternative for in vitro studies, particularly as it can be obtained under overall rather straightforward cell culture conditions and thus low assay costs.
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35
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A microscopic multiphase diffusion model of viable epidermis permeability. Biophys J 2013; 104:2307-20. [PMID: 23708370 DOI: 10.1016/j.bpj.2013.03.056] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2012] [Revised: 03/25/2013] [Accepted: 03/26/2013] [Indexed: 11/21/2022] Open
Abstract
A microscopic model of passive transverse mass transport of small solutes in the viable epidermal layer of human skin is formulated on the basis of a hexagonal array of cells (i.e., keratinocytes) bounded by 4-nm-thick, anisotropic lipid bilayers and separated by 1-μm layers of extracellular fluid. Gap junctions and tight junctions with adjustable permeabilities are included to modulate the transport of solutes with low membrane permeabilities. Two keratinocyte aspect ratios are considered to represent basal and spinous cells (longer) and granular cells (more flattened). The diffusion problem is solved in a unit cell using a coordinate system conforming to the hexagonal cross section, and an efficient two-dimensional treatment is applied to describe transport in both the cell membranes and intercellular spaces, given their thinness. Results are presented in terms of an effective diffusion coefficient, D¯(epi), and partition coefficient, K¯(epi/w), for a homogenized representation of the microtransport problem. Representative calculations are carried out for three small solutes-water, L-glucose, and hydrocortisone-covering a wide range of membrane permeability. The effective transport parameters and their microscopic interpretation can be employed within the context of existing three-layer models of skin transport to provide more realistic estimates of the epidermal concentrations of topically applied solutes.
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36
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Das C, Noro MG, Olmsted PD. Lamellar and inverse micellar structures of skin lipids: effect of templating. PHYSICAL REVIEW LETTERS 2013; 111:148101. [PMID: 24138273 DOI: 10.1103/physrevlett.111.148101] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2013] [Indexed: 06/02/2023]
Abstract
The outermost layer of skin comprises rigid nonviable cells (corneocytes) in a layered lipid matrix. Using atomistic simulations we find that the equilibrium phase of the skin lipids is inverse micellar. A model of the corneocyte is used to demonstrate that lamellar layering is induced by the patterned corneocyte wall. The inverse micellar phase is consistent with in vivo observations in regions where corneocyte walls are well separated (lacunar spaces) and in the inner layers of skin, and suggests a functional role in the lipid synthesis pathway in vivo.
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Affiliation(s)
- Chinmay Das
- School of Physics and Astronomy, University of Leeds, Leeds LS2 9JT, United Kingdom
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37
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Al-Jassar C, Bikker H, Overduin M, Chidgey M. Mechanistic basis of desmosome-targeted diseases. J Mol Biol 2013; 425:4006-22. [PMID: 23911551 PMCID: PMC3807649 DOI: 10.1016/j.jmb.2013.07.035] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2013] [Revised: 07/23/2013] [Accepted: 07/24/2013] [Indexed: 11/21/2022]
Abstract
Desmosomes are dynamic junctions between cells that maintain the structural integrity of skin and heart tissues by withstanding shear forces. Mutations in component genes cause life-threatening conditions including arrhythmogenic right ventricular cardiomyopathy, and desmosomal proteins are targeted by pathogenic autoantibodies in skin blistering diseases such as pemphigus. Here, we review a set of newly discovered pathogenic alterations and discuss the structural repercussions of debilitating mutations on desmosomal proteins. The architectures of native desmosomal assemblies have been visualized by cryo-electron microscopy and cryo-electron tomography, and the network of protein domain interactions is becoming apparent. Plakophilin and desmoplakin mutations have been discovered to alter binding interfaces, structures, and stabilities of folded domains that have been resolved by X-ray crystallography and NMR spectroscopy. The flexibility within desmoplakin has been revealed by small-angle X-ray scattering and fluorescence assays, explaining how mechanical stresses are accommodated. These studies have shown that the structural and functional consequences of desmosomal mutations can now begin to be understood at multiple levels of spatial and temporal resolution. This review discusses the recent structural insights and raises the possibility of using modeling for mechanism-based diagnosis of how deleterious mutations alter the integrity of solid tissues.
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Affiliation(s)
- Caezar Al-Jassar
- School of Cancer Sciences, University of Birmingham, Birmingham B15 2TT, UK
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38
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Beard JD, Guy RH, Gordeev SN. Mechanical Tomography of Human Corneocytes with a Nanoneedle. J Invest Dermatol 2013; 133:1565-71. [DOI: 10.1038/jid.2012.465] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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39
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Hong SK, Ma JY, Kim JC. In Vitro Skin Permeation Enhancement of KIOM-MA-128 by Monoolein Cubosomes. J DISPER SCI TECHNOL 2012. [DOI: 10.1080/01932691.2011.620863] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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40
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The human skin barrier is organized as stacked bilayers of fully extended ceramides with cholesterol molecules associated with the ceramide sphingoid moiety. J Invest Dermatol 2012; 132:2215-25. [PMID: 22534876 DOI: 10.1038/jid.2012.43] [Citation(s) in RCA: 157] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The skin barrier is fundamental to terrestrial life and its evolution; it upholds homeostasis and protects against the environment. Skin barrier capacity is controlled by lipids that fill the extracellular space of the skin's surface layer--the stratum corneum. Here we report on the determination of the molecular organization of the skin's lipid matrix in situ, in its near-native state, using a methodological approach combining very high magnification cryo-electron microscopy (EM) of vitreous skin section defocus series, molecular modeling, and EM simulation. The lipids are organized in an arrangement not previously described in a biological system-stacked bilayers of fully extended ceramides (CERs) with cholesterol molecules associated with the CER sphingoid moiety. This arrangement rationalizes the skin's low permeability toward water and toward hydrophilic and lipophilic substances, as well as the skin barrier's robustness toward hydration and dehydration, environmental temperature and pressure changes, stretching, compression, bending, and shearing.
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41
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Bouchet-Marquis C, Zuber B, Glynn AM, Eltsov M, Grabenbauer M, Goldie KN, Thomas D, Frangakis AS, Dubochet J, Chrétien D. Visualization of cell microtubules in their native state. Biol Cell 2012; 99:45-53. [PMID: 17049046 DOI: 10.1042/bc20060081] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
BACKGROUND INFORMATION Over the past decades, cryo-electron microscopy of vitrified specimens has yielded a detailed understanding of the tubulin and microtubule structures of samples reassembled in vitro from purified components. However, our knowledge of microtubule structure in vivo remains limited by the chemical treatments commonly used to observe cellular architecture using electron microscopy. RESULTS We used cryo-electron microscopy and cryo-electron tomography of vitreous sections to investigate the ultrastructure of microtubules in their cellular context. Vitreous sections were obtained from organotypic slices of rat hippocampus and from Chinese-hamster ovary cells in culture. Microtubules revealed their protofilament ultrastructure, polarity and, in the most favourable cases, molecular details comparable with those visualized in three-dimensional reconstructions of microtubules reassembled in vitro from purified tubulin. The resolution of the tomograms was estimated to be approx. 4 nm, which enabled the detection of luminal particles of approx. 6 nm in diameter inside microtubules. CONCLUSIONS The present study provides a first step towards a description of microtubules, in addition to other macromolecular assemblies, in an unperturbed cellular context at the molecular level. As the resolution appears to be similar to that obtainable with plunge-frozen samples, it should allow for the in vivo identification of larger macromolecular assemblies in vitreous sections of whole cells and tissues.
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Affiliation(s)
- Cédric Bouchet-Marquis
- Laboratory for Ultrastructural Analysis, Biophore, University of Lausanne, CH-1015 Lausanne, Switzerland
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42
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Tong YC, Yu TY, Chang SF, Liaw J. Nanopolymeric micelle effect on the transdermal permeability, the bioavailability and gene expression of plasmid. Mol Pharm 2011; 9:111-20. [PMID: 22142416 DOI: 10.1021/mp200342h] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
This study attempts to investigate the transdermal permeability, the bioavailability and gene expression of plasmid formulated with nonionic poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) (PEO-PPO-PEO) polymeric micelles (PM). Dynamic light scattering (DLS) and atomic force microscopy (AFM) were used to analyze the PM formulated pCMV-Lac Z (P/PM) containing the gene for β-galactosidase (β-Gal) driven by cytomegalovirus early promoter. Franz diffusion cell was used for in vitro transdermal permeability analysis. Real-time PCR was used to quantify the permeated plasmid in vitro and in vivo. β-Gal activity assay was performed to evaluate transgene expression in vivo. The size of P/PM was ~50 nm with round shape. PM significantly enhanced the in vitro transdermal permeability of plasmid in a direction- and temperature-dependent manner. Following transdermal application of P/PM, higher area under the curve (AUC(P/PM): 98.34 h·ng/mL) and longer half-life of plasmid were detected compared with that of plasmid alone (AUC(P): 10.12 h·ng/mL). Additionally, the β-Gal activity was significantly increased in skin, stomach, brain and spinal cord at both 48 and 72 h after P/PM application and in testis and spleen at 72 h postapplication. In conclusion, PM formulation enhanced the permeation of plasmid through skin into blood circulation, increasing its absorption and the transgene expression in various tissues.
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Affiliation(s)
- Yaw-Chong Tong
- College of Pharmacy, Taipei Medical University, Taipei, Taiwan
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Abstract
Classical cadherins mediate specific adhesion at intercellular adherens junctions. Interactions between cadherin ectodomains from apposed cells mediate cell-cell contact, whereas the intracellular region functionally links cadherins to the underlying cytoskeleton. Structural, biophysical, and biochemical studies have provided important insights into the mechanism and specificity of cell-cell adhesion by classical cadherins and their interplay with the cytoskeleton. Adhesive binding arises through exchange of beta strands between the first extracellular cadherin domains (EC1) of partner cadherins from adjacent cells. This "strand-swap" binding mode is common to classical and desmosomal cadherins, but sequence alignments suggest that other cadherins will bind differently. The intracellular region of classical cadherins binds to p120 and beta-catenin, and beta-catenin binds to the F-actin binding protein alpha-catenin. Rather than stably bridging beta-catenin to actin, it appears that alpha-catenin actively regulates the actin cytoskeleton at cadherin-based cell-cell contacts.
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Abstract
Desmosomes are intercellular junctions whose primary function is strong intercellular adhesion, known as hyperadhesion. In the present review, we discuss how their structure appears to support this function as well as how they are assembled and down-regulated. Desmosomal components also have signalling functions that are important in tissue development and remodelling. Their adhesive and signalling functions are both compromised in genetic and autoimmune diseases that affect the heart, skin and mucous membranes. We conclude that much work is required on structure–function relationships within desmosomes in vivo and on how they participate in signalling processes to enhance our knowledge of tissue homoeostasis and human disease.
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Abstract
The structure, function, and regulation of desmosomal adhesion in vivo are discussed. Most desmosomes in tissues exhibit calcium-independent adhesion, which is strongly adhesive or “hyperadhesive”. This is fundamental to tissue strength. Almost all studies in culture are done on weakly adhesive, calcium-dependent desmosomes, although hyperadhesion can be readily obtained in confluent cell culture. Calcium dependence is a default condition in vivo, found in wounds and embryonic development. Hyperadhesion appears to be associated with an ordered arrangement of the extracellular domains of the desmosomal cadherins, which gives rise to the intercellular midline identified in ultrastructural studies. This in turn probably depends on molecular order in the desmosomal plaque. Protein kinase C downregulates hyperadhesion and there is preliminary evidence that it may also be regulated by tyrosine kinases. Downregulation of desmosomes in vivo may occur by internalisation of whole desmosomes rather than disassembly. Hyperadhesion has implications for diseases such as pemphigus.
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46
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Puckett SD, Lee PP, Ciombor DM, Aaron RK, Webster TJ. Nanotextured titanium surfaces for enhancing skin growth on transcutaneous osseointegrated devices. Acta Biomater 2010; 6:2352-62. [PMID: 20005310 DOI: 10.1016/j.actbio.2009.12.016] [Citation(s) in RCA: 82] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2009] [Revised: 12/06/2009] [Accepted: 12/07/2009] [Indexed: 11/16/2022]
Abstract
A major problem with transcutaneous osseointegrated implants is infection, mainly due to improper closure of the implant-skin interface. Therefore, the design of transcutaneous osseointegrated devices that better promote skin growth around these exit sites needs to be examined and, if successful, would clearly limit infection. Due to the success already demonstrated for orthopedic implants, developing surfaces with biologically inspired nanometer features is a design criterion that needs to be investigated for transcutaneous devices. This study therefore examined the influence of nanotextured titanium (Ti) created through electron beam evaporation and anodization on keratinocyte (skin-forming cell) function. Electron beam evaporation created Ti surfaces with nanometer features while anodization created Ti surfaces with nanotubes. Conventional Ti surfaces were largely micron rough, with few nanometer surface features. Results revealed increased keratinocyte adhesion in addition to increased keratinocyte spreading and differences in keratinocyte filopodia extension on the nanotextured Ti surfaces prepared by either electron beam evaporation or anodization compared to their conventional, unmodified counterparts after 4h. Results further revealed increased keratinocyte proliferation and cell spreading over 3 and 5days only on the nanorough Ti surfaces prepared by electron beam evaporation compared to both the anodized nanotubular and unmodified Ti surfaces. Therefore, the results from this in vitro study provided the first evidence that nano-modification techniques should be further researched as a means to possibly improve skin growth, thereby improving transcutaneous osseointegrated orthopedic implant longevity.
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Affiliation(s)
- Sabrina D Puckett
- Division of Engineering, Brown University, Providence, RI 02912, USA
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47
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Lian G, Chen L, Pudney PDA, Mélot M, Han L. Modeling transdermal permeation. Part 2. Predicting the dermatopharmacokinetics of percutaneous solute. AIChE J 2010. [DOI: 10.1002/aic.12146] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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48
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Kessner D, Brezesinski G, Funari SS, Dobner B, Neubert RH. Impact of the long chain ω-acylceramides on the stratum corneum lipid nanostructure. Part 1: Thermotropic phase behaviour of CER[EOS] and CER[EOP] studied using X-ray powder diffraction and FT-Raman spectroscopy. Chem Phys Lipids 2010; 163:42-50. [DOI: 10.1016/j.chemphyslip.2009.10.007] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2009] [Revised: 10/12/2009] [Accepted: 10/26/2009] [Indexed: 11/26/2022]
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49
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Baroli B. Penetration of nanoparticles and nanomaterials in the skin: Fiction or reality? J Pharm Sci 2010; 99:21-50. [DOI: 10.1002/jps.21817] [Citation(s) in RCA: 241] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
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50
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Höög JL, Gluenz E, Vaughan S, Gull K. Ultrastructural investigation methods for Trypanosoma brucei. Methods Cell Biol 2010; 96:175-96. [PMID: 20869523 DOI: 10.1016/s0091-679x(10)96008-1] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Trypanosoma brucei is a unicellular parasite causing African sleeping sickness in cattle and humans. Due to the ease with which these cells can be cultured and genetically manipulated, it has emerged as a model organism for the kinetoplastids.In this chapter we describe the preparation of T. brucei for transmission electron microscopy. A thorough explanation of conventional sample preparation through chemical fixation of whole cells and detergent extracted cytoskeletons followed by dehydration and Epon embedding is given. We also introduce a novel high-pressure freezing protocol, which followed by rapid freeze substitution and HM20 embedding generates T. brucei samples displaying good cell morphology, which are suitable for immunocytochemistry.
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Affiliation(s)
- Johanna L Höög
- Sir William Dunn School of Pathology, University of Oxford, Oxford OX13RE, United Kingdom
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