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Lyu Y, Guan Y, Deliu L, Humphrey E, Frontera JK, Yang YJ, Zamler D, Kim KH, Mohanty V, Jin K, Mohanty V, Liu V, Dou J, Veillon LJ, Kumar SV, Lorenzi PL, Chen Y, McAndrews KM, Grivennikov S, Song X, Zhang J, Xi Y, Wang J, Chen K, Nagarajan P, Ge Y. KLF5 governs sphingolipid metabolism and barrier function of the skin. Genes Dev 2022; 36:gad.349662.122. [PMID: 36008138 PMCID: PMC9480852 DOI: 10.1101/gad.349662.122] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Accepted: 08/15/2022] [Indexed: 01/03/2023]
Abstract
Stem cells are fundamental units of tissue remodeling whose functions are dictated by lineage-specific transcription factors. Home to epidermal stem cells and their upward-stratifying progenies, skin relies on its secretory functions to form the outermost protective barrier, of which a transcriptional orchestrator has been elusive. KLF5 is a Krüppel-like transcription factor broadly involved in development and regeneration whose lineage specificity, if any, remains unclear. Here we report KLF5 specifically marks the epidermis, and its deletion leads to skin barrier dysfunction in vivo. Lipid envelopes and secretory lamellar bodies are defective in KLF5-deficient skin, accompanied by preferential loss of complex sphingolipids. KLF5 binds to and transcriptionally regulates genes encoding rate-limiting sphingolipid metabolism enzymes. Remarkably, skin barrier defects elicited by KLF5 ablation can be rescued by dietary interventions. Finally, we found that KLF5 is widely suppressed in human diseases with disrupted epidermal secretion, and its regulation of sphingolipid metabolism is conserved in human skin. Altogether, we established KLF5 as a disease-relevant transcription factor governing sphingolipid metabolism and barrier function in the skin, likely representing a long-sought secretory lineage-defining factor across tissue types.
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Affiliation(s)
- Ying Lyu
- Department of Cancer Biology, University of Texas MD Anderson Cancer Center, Houston, Texas 77030, USA
| | - Yinglu Guan
- Department of Cancer Biology, University of Texas MD Anderson Cancer Center, Houston, Texas 77030, USA
| | - Lisa Deliu
- Department of Cancer Biology, University of Texas MD Anderson Cancer Center, Houston, Texas 77030, USA
| | - Ericka Humphrey
- Department of Cancer Biology, University of Texas MD Anderson Cancer Center, Houston, Texas 77030, USA
| | - Joanna K Frontera
- Department of Cancer Biology, University of Texas MD Anderson Cancer Center, Houston, Texas 77030, USA
| | - Youn Joo Yang
- Department of Cancer Biology, University of Texas MD Anderson Cancer Center, Houston, Texas 77030, USA
| | - Daniel Zamler
- Department of Cancer Biology, University of Texas MD Anderson Cancer Center, Houston, Texas 77030, USA
| | - Kun Hee Kim
- Department of Bioinformatics and Computational Biology, University of Texas MD Anderson Cancer Center, Houston, Texas 77030, USA
| | - Vakul Mohanty
- Department of Bioinformatics and Computational Biology, University of Texas MD Anderson Cancer Center, Houston, Texas 77030, USA
| | - Kevin Jin
- Department of Cancer Biology, University of Texas MD Anderson Cancer Center, Houston, Texas 77030, USA
- Rice University, Houston, Texas 77005, USA
| | - Vakul Mohanty
- Department of Cancer Biology, University of Texas MD Anderson Cancer Center, Houston, Texas 77030, USA
- Rice University, Houston, Texas 77005, USA
| | - Virginia Liu
- Department of Cancer Biology, University of Texas MD Anderson Cancer Center, Houston, Texas 77030, USA
- Rice University, Houston, Texas 77005, USA
| | - Jinzhuang Dou
- Department of Bioinformatics and Computational Biology, University of Texas MD Anderson Cancer Center, Houston, Texas 77030, USA
| | - Lucas J Veillon
- Department of Bioinformatics and Computational Biology, University of Texas MD Anderson Cancer Center, Houston, Texas 77030, USA
| | - Shwetha V Kumar
- Department of Bioinformatics and Computational Biology, University of Texas MD Anderson Cancer Center, Houston, Texas 77030, USA
| | - Philip L Lorenzi
- Department of Bioinformatics and Computational Biology, University of Texas MD Anderson Cancer Center, Houston, Texas 77030, USA
| | - Yang Chen
- Department of Cancer Biology, University of Texas MD Anderson Cancer Center, Houston, Texas 77030, USA
| | - Kathleen M McAndrews
- Department of Cancer Biology, University of Texas MD Anderson Cancer Center, Houston, Texas 77030, USA
| | - Sergei Grivennikov
- Department of Medicine, Comprehensive Cancer Institute, Cedars-Sinai Medical Center, Los Angeles, California 90048, USA
- Department of Biomedical Sciences, Comprehensive Cancer Institute, Cedars-Sinai Medical Center, Los Angeles, California 90048, USA
| | - Xingzhi Song
- Department of Genomic Medicine, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030, USA
| | - Jianhua Zhang
- Department of Genomic Medicine, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030, USA
| | - Yuanxin Xi
- Department of Bioinformatics and Computational Biology, University of Texas MD Anderson Cancer Center, Houston, Texas 77030, USA
| | - Jing Wang
- Department of Bioinformatics and Computational Biology, University of Texas MD Anderson Cancer Center, Houston, Texas 77030, USA
| | - Ken Chen
- Department of Bioinformatics and Computational Biology, University of Texas MD Anderson Cancer Center, Houston, Texas 77030, USA
| | - Priyadharsini Nagarajan
- Department of Pathology, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030, USA
| | - Yejing Ge
- Department of Cancer Biology, University of Texas MD Anderson Cancer Center, Houston, Texas 77030, USA
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Lu JY, Huang WT, Zhou K, Zhao X, Yang S, Xia L, Ding X. Microbial Lipopeptide Supramolecular Self-Assemblies as a Methuosis-Like Cell Death Inducer with In Vivo Antitumor Activity. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2022; 18:e2104034. [PMID: 34761865 DOI: 10.1002/smll.202104034] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2021] [Revised: 09/26/2021] [Indexed: 06/13/2023]
Abstract
Discovering new drugs and improving action mechanisms is a promising strategy to overcome chemotherapy ineffectiveness caused by cancer cell apoptosis resistance. Natural products (like cyclic lipopeptides, CLPs) are potential sources of nonapoptotic cell death inducers and can form diverse supramolecular structures, closely relating to their bioactivities. Herein, it is found for the first time that fatty chain is the key to maintain self-assembled form and antitumor activity of microbial-derived amphiphilic CLP bacillomycin Lb (B-Lb). Compared with B-Lb analogues assemblies without antitumor activity, B-Lb supramolecular self-assemblies (including nanomicelles, nanofibers, giant micrometer rods) can be generated in a multilevel and cross-scale manner and served as a methuosis-like cell death inducer triggered by cytoplasmic vacuolation through macropinocytosis in MDA-MB-231-Luc and MCF-7 cells and in vivo tumor-bearing mice. This study will promote constructing of customized CLP micro-/nanostructures with multipurposes and functions, and boost designing of new antitumor drugs as nonapoptotic cell death modulators based on structure-activity relationship.
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Affiliation(s)
- Jiao Yang Lu
- Hunan Provincial Key Laboratory of Microbial Molecular Biology, State Key Laboratory of Developmental Biology of Freshwater Fish, College of Life Science, Hunan Normal University, Changsha, 410081, P. R. China
- Academician Workstation, Changsha Medical University, Changsha, 410219, P. R. China
| | - Wei Tao Huang
- Hunan Provincial Key Laboratory of Microbial Molecular Biology, State Key Laboratory of Developmental Biology of Freshwater Fish, College of Life Science, Hunan Normal University, Changsha, 410081, P. R. China
| | - Kexuan Zhou
- Hunan Provincial Key Laboratory of Microbial Molecular Biology, State Key Laboratory of Developmental Biology of Freshwater Fish, College of Life Science, Hunan Normal University, Changsha, 410081, P. R. China
| | - Xiaoli Zhao
- Hunan Provincial Key Laboratory of Microbial Molecular Biology, State Key Laboratory of Developmental Biology of Freshwater Fish, College of Life Science, Hunan Normal University, Changsha, 410081, P. R. China
| | - Shuqing Yang
- Hunan Provincial Key Laboratory of Microbial Molecular Biology, State Key Laboratory of Developmental Biology of Freshwater Fish, College of Life Science, Hunan Normal University, Changsha, 410081, P. R. China
| | - Liqiu Xia
- Hunan Provincial Key Laboratory of Microbial Molecular Biology, State Key Laboratory of Developmental Biology of Freshwater Fish, College of Life Science, Hunan Normal University, Changsha, 410081, P. R. China
| | - Xuezhi Ding
- Hunan Provincial Key Laboratory of Microbial Molecular Biology, State Key Laboratory of Developmental Biology of Freshwater Fish, College of Life Science, Hunan Normal University, Changsha, 410081, P. R. China
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The Skin's Barrier: A Cryo-EM Based Overview of its Architecture and Stepwise Formation. J Invest Dermatol 2021; 142:285-292. [PMID: 34474746 DOI: 10.1016/j.jid.2021.06.037] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Revised: 06/28/2021] [Accepted: 06/30/2021] [Indexed: 01/22/2023]
Abstract
A major role of the skin is to serve as a barrier toward the environment. The skin's permeability barrier consists of a lipid structure positioned in the stratum corneum. Recent progress in high-resolution cryo-electron microscopy (cryo-EM) has allowed for elucidation of the architecture of the skin's barrier and its stepwise formation process representing the final stage of epidermal differentiation. In this review, we present an overview of the skin's barrier structure and its formation process, as evidenced by cryo-EM.
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Meyer JM, Crumrine D, Schneider H, Dick A, Schmuth M, Gruber R, Radner FPW, Grond S, Wakefield JS, Mauro TM, Elias PM. Unbound Corneocyte Lipid Envelopes in 12R-Lipoxygenase Deficiency Support a Specific Role in Lipid-Protein Cross-Linking. THE AMERICAN JOURNAL OF PATHOLOGY 2021; 191:921-929. [PMID: 33607042 DOI: 10.1016/j.ajpath.2021.02.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Revised: 01/26/2021] [Accepted: 02/02/2021] [Indexed: 12/15/2022]
Abstract
Loss-of-function mutations in arachidonate lipoxygenase 12B (ALOX12B) are an important cause of autosomal recessive congenital ichthyosis (ARCI). 12R-lipoxygenase (12R-LOX), the protein product of ALOX12B, has been proposed to covalently bind the corneocyte lipid envelope (CLE) to the proteinaceous corneocyte envelope, thereby providing a scaffold for the assembly of barrier-providing, mature lipid lamellae. To test this hypothesis, an in-depth ultrastructural examination of CLEs was performed in ALOX12B-/- human and Alox12b-/- mouse epidermis, extracting samples with pyridine to distinguish covalently attached CLEs from unbound (ie, noncovalently bound) CLEs. ALOX12B--/- stratum corneum contained abundant pyridine-extractable (ie, unbound) CLEs, compared with normal stratum corneum. These unbound CLEs were associated with defective post-secretory lipid processing, and were specific to 12R-LOX deficiency, because they were not observed with deficiency of the related ARCI-associated proteins, patatin-like phospholipase 1 (Pnpla1) or abhydrolase domain containing 5 (Abhd5). These results suggest that 12R-LOX contributes specifically to CLE-corneocyte envelope cross-linking, which appears to be a prerequisite for post-secretory lipid processing, and provide insights into the pathogenesis of 12R-LOX deficiency in this subtype of ARCI, as well as other conditions that display a defective CLE.
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Affiliation(s)
- Jason M Meyer
- San Francisco Veterans Affairs Medical Center, Dermatology Service and UC San Francisco Department of Dermatology, San Francisco, California.
| | - Debra Crumrine
- San Francisco Veterans Affairs Medical Center, Dermatology Service, San Francisco, California
| | - Holm Schneider
- Department of Pediatrics, University of Erlangen-Nürnberg, Nürnberg, Germany
| | - Angela Dick
- Department of Pediatrics, University of Erlangen-Nürnberg, Nürnberg, Germany
| | - Matthias Schmuth
- Department of Dermatology, Venereology and Allergology, Medical University of Innsbruck, Innsbruck, Austria
| | - Robert Gruber
- Department of Dermatology, Venereology and Allergology, Medical University of Innsbruck, Innsbruck, Austria
| | - Franz P W Radner
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Susanne Grond
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Joan S Wakefield
- San Francisco Veterans Affairs Medical Center, Dermatology Service and UC San Francisco Department of Dermatology, San Francisco, California
| | - Theodora M Mauro
- San Francisco Veterans Affairs Medical Center, Dermatology Service and UC San Francisco Department of Dermatology, San Francisco, California
| | - Peter M Elias
- San Francisco Veterans Affairs Medical Center, Dermatology Service and UC San Francisco Department of Dermatology, San Francisco, California
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Menon GK, Lee SE, Lee SH. An overview of epidermal lamellar bodies: Novel roles in biological adaptations and secondary barriers. J Dermatol Sci 2018; 92:10-17. [PMID: 30153959 DOI: 10.1016/j.jdermsci.2018.03.005] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2017] [Revised: 02/22/2018] [Accepted: 03/06/2018] [Indexed: 11/29/2022]
Abstract
The epidermal lamellar bodies (LBs) are specialized organelles that contain pro-barrier lipids imparting a fully lamellar internal structure, but also other cargoes such as enzymes (lipid metabolizing and proteolytic), enzyme inhibitors, and antimicrobial peptides. Thus, the LB secretory system, by virtue of delivering these cargoes to the stratum corneum (SC) interstices, is essential for forming the various skin barriers located in the SC. Ultrastructural studies have suggested that the morphologic features of LBs reflect the functional status of the SC. Several ichthyotic skin diseases as well as experimental animal models with defective epidermal lipogenesis show only partial lamellar contents or even empty appearing LB, reflecting an abnormal cargo composition. We suggest that LB polymorphism reflects a wide array of barrier adaptations to environmental challenges, rather than just a defective barrier function, based on observations on a) LB morphology in inherited skin disorders of lipid metabolism (Refsum disease, Chanarin-Dorfman syndrome) characterized by deficiency of lamellar lipids and accumulation of toxic metabolites; b) Psoriasis (with a high expression of Psoriasin antimicrobial peptide within lesions) and c) the Pitohui, a toxic bird where diet-derived toxin is eliminated via the LB secretory system that creates a chemical defense system. Morphological features of LBs from these models suggest a hitherto unrecognized function for the LBs in elimination of toxic substances from the body. We also provide preliminary evidence that indicate yet another function for the LBs- as a type of recycling endosomes allowing for uptake of certain topically applied materials by the epidermis.
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Affiliation(s)
| | - Sang Eun Lee
- Department of Dermatology and Cutaneous Biology Research Institute, Yonsei University College of Medicine, Seoul, South Korea.
| | - Seung-Hun Lee
- Department of Dermatology and Cutaneous Biology Research Institute, Yonsei University College of Medicine, Seoul, South Korea
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6
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Nucleophagy: A New Look at Past Observations. J Invest Dermatol 2016; 136:1316-1318. [PMID: 27155459 DOI: 10.1016/j.jid.2016.04.019] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2016] [Revised: 04/22/2016] [Accepted: 04/23/2016] [Indexed: 12/18/2022]
Abstract
Keratinization of the stratum corneum involves a highly choreographed sequence of events in which granular cells lose their nuclei and become desiccated corneocytes. Akinduro et al. detail the molecular machinery underlying removal of the nucleus (nucleophagy) during the final stages of keratinization. They provide evidence that nucleophagy is induced when the keratinocytes differentiate and that failure in the initiation of nucleophagy is associated with parakeratosis.
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7
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Larsen EH, Deaton LE, Onken H, O'Donnell M, Grosell M, Dantzler WH, Weihrauch D. Osmoregulation and Excretion. Compr Physiol 2014; 4:405-573. [DOI: 10.1002/cphy.c130004] [Citation(s) in RCA: 127] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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Kim H, Shin JU, Lee KH. Atopic dermatitis and skin barrier dysfunction. ALLERGY ASTHMA & RESPIRATORY DISEASE 2013. [DOI: 10.4168/aard.2013.1.1.20] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Affiliation(s)
- Hyunjung Kim
- Department of Dermatology, Atopy and Asthma Center, Medical Research Institute, Seoul Medical Center, Seoul, Korea
| | - Jung U Shin
- Department of Dermatology, Cutaneous Biology Research Institute, Yonsei University College of Medicine, Seoul, Korea
| | - Kwang Hoon Lee
- Department of Dermatology, Cutaneous Biology Research Institute, Yonsei University College of Medicine, Seoul, Korea
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Sapra B, Jain S, Tiwary AK. Transdermal delivery of carvedilol in rats: probing the percutaneous permeation enhancement mechanism of soybean extract-chitosan mixture. Drug Dev Ind Pharm 2009; 35:1230-41. [PMID: 19555244 DOI: 10.1080/03639040902882272] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
BACKGROUND This study was designed for investigating the effect of soybean (SS) extract and chitosan (CTN) in facilitating the permeation of carvedilol (CDL) across rat epidermis. METHOD Transdermal flux of carvedilol through heat-separated rat epidermis was investigated in vitro using vertical Keshary-Chien diffusion cells. Biophysical and microscopic manifestations of epidermis treated with SS-extract, CTN, and SS extract-CTN mixture were investigated by using DSC, TEWL, SEM, and TEM. Biochemical estimations of cholesterol, sphingosine, and triglycerides were carried out for treated excised as well as viable rat epidermis. The antihypertensive activity of the patches in comparison to that after oral administration of carvedilol was studied in deoxycorticosterone acetate-induced hypertensive rats. RESULTS The solubility of CDL was found to be maximum in the presence of 1% (w/v) SS extract. The K(IPM/PB) of CDL decreased with increase in concentration of SS extract. The in vitro permeation of CDL across rat epidermis increased and was maximum with combination of SS extract and chitosan (CTN). Biochemical and microscopic studies revealed the initiation of reversal of barrier integrity after 12 hours. Furthermore, the application of patches containing SS extract-CTN mixture resulted in sustained release of carvedilol, which was able to control the hypertension in deoxycorticosterone acetate (DOCA) induced hypertensive rats through 24 hours. CTN was found to potentiate the permeation enhancing activity of SS extract. CONCLUSION The developed transdermal patches of CDL containing SS extract-CTN mixture exhibited better performance as compared to oral administration in controlling hypertension in rats.
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Affiliation(s)
- Bharti Sapra
- Department of Pharmaceutical Sciences and Drug Research, Punjabi University, Patiala, Punjab, India
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Abstract
Atopic dermatitis (AD) is a multifactorial, heterogenous disease that arises as a result of the interaction between both environmental and genetic factors. Changes in at least three groups of genes encoding structural proteins, epidermal proteases, and protease inhibitors predispose to a defective epidermal barrier and increase the risk of developing AD. Loss-of-function mutations found within the FLG gene encoding the structural protein, filaggrin, represent the most significant genetic factor predisposing to AD identified to date. Enhanced protease activity and decreased synthesis of the lipid lamellae lead to exacerbated breakdown of the epidermal barrier. Environmental factors, including the use of soap and detergents, exacerbate epidermal barrier breakdown, attributed to the elevation of stratum corneum pH. A sustained increase in pH enhances the activity of degradatory proteases and decreases the activity of the lipid synthesis enzymes. The strong association between both genetic barrier defects and environmental insults to the barrier with AD suggests that epidermal barrier dysfunction is a primary event in the development of this disease. Our understanding of gene-environment interactions should lead to a better use of some topical products, avoidance of others, and the increased use and development of products that can repair the skin barrier.
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Cork MJ, Moustafa M, Danby S, Vasilopoulos Y, Tazi-Ahnini R, Ward SJ, Hadgraft J, Lane ME, Guy R, MacGowan A. Skin Barrier Dysfunction in Atopic Dermatitis. BASIC AND CLINICAL DERMATOLOGY 2009. [DOI: 10.3109/9781420070958.013] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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Sapra B, Jain S, Tiwary AK. Effect of Asparagus racemosus extract on transdermal delivery of carvedilol: a mechanistic study. AAPS PharmSciTech 2009; 10:199-210. [PMID: 19238554 DOI: 10.1208/s12249-009-9198-1] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2008] [Accepted: 01/31/2009] [Indexed: 11/30/2022] Open
Abstract
This study was designed for investigating the effect of Asparagus racemosus (AR) extract and chitosan (CTN) in facilitating the permeation of carvedilol (CDL) across rat epidermis. Transdermal flux of carvedilol through heat-separated rat epidermis was investigated in vitro using vertical Keshary-Chien diffusion cells. Biophysical and microscopic manifestations of epidermis treated with AR extract, CTN, and AR extract-CTN mixture were investigated by using differential scanning calorimetry, transepidermal water loss, scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Biochemical estimations of cholesterol, sphingosine, and triglycerides were carried out for treated excised as well as viable rat epidermis. The antihypertensive activity of the patches in comparison with that of oral carvedilol was studied in deoxycorticosterone acetate-induced hypertensive rats. The permeation of carvedilol across excised rat epidermis was significantly higher (p < 0.05) when AR extract, CTN, or AR extract-CTN mixture was used as donor vehicle as compared to propylene glycol/ethanol (7:3) mixture. Epidermis obtained after 12 h treatment of viable rat skin with AR extract-CTN mixture showed significantly higher (p < 0.05) permeability to CDL as compared to that after treatment with AR extract or CTN alone. Further, the application of patches containing AR extract-CTN mixture resulted in sustained release of CDL which was able to control the hypertension in deoxycorticosterone acetate-induced hypertensive rats through 36 h. Estimation of micro constituents in rat epidermis revealed maximum extraction of cholesterol, sphingosine, and triglycerides after treatment with AR extract-CTN mixture. This was manifested in altered lipid and protein-specific thermotropic transitions. Further, increase in intercellular space, disordered lipid structure, and corneocyte detachment as observed in SEM and TEM suggested great potential of AR extract for use as percutaneous permeation enhancer. The developed transdermal patches of CDL containing AR extract-CTN mixture exhibited better performance as compared to oral administration in controlling hypertension in rats.
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Sapra B, Jain S, Tiwary AK. Transdermal delivery of carvedilol containing glycyrrhizin and chitosan as permeation enhancers: biochemical, biophysical, microscopic and pharmacodynamic evaluation. Drug Deliv 2008; 15:443-54. [PMID: 18712622 DOI: 10.1080/10717540802327047] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
Abstract
The present study was aimed at unveiling the influence of glycyrrhizin and chitosan on rat epidermis and to correlate these effects with percutaneous permeation characteristics of carvedilol. The permeation of carvedilol across excised rat epidermis was significantly higher (p < 0.05) when glycyrrhizin, chitosan, or glycyrrhizin-chitosan mixture was used as a donor vehicle as compared to propylene glycol:ethanol (7:3) mixture. Epidermis obtained after 12 hr treatment of viable rat skin with a glycyrrhizin-chitosan mixture showed significantly higher (p < 0.05) permeability to carvedilol as compared to that after treatment with glycyrrhizin or chitosan alone. Further, the application of patches containing glycyrrhizin-chitosan mixture resulted in sustained release of carvedilol, which was able to control the hypertension in deoxycorticosterone acetate induced hypertensive rats through 28 hr. Estimation of microconstituents in rat epidermis revealed maximum extraction of cholesterol, sphingosine, and triglycerides after treatment with glycyrrhizin-chitosan mixture. This was manifested in altered lipid and protein-specific thermotropic transitions. Further, increase in intercellular space, disordered lipid structure and corneocyte detachment as observed in SEM and TEM suggests great potential of glycyrrhizin for use as a percutaneous permeation enhancer.
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Affiliation(s)
- Bharti Sapra
- Department of Pharmaceutical Sciences and Drug Research, Punjabi University, Patiala, India
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15
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Roberts JB. Use of Squamate Epidermis in Percutaneous Absorption Studies: A Review. ACTA ACUST UNITED AC 2008. [DOI: 10.3109/15569528609036305] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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16
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Bender J, Simonsson C, Smedh M, Engström S, Ericson MB. Lipid cubic phases in topical drug delivery: Visualization of skin distribution using two-photon microscopy. J Control Release 2008; 129:163-9. [DOI: 10.1016/j.jconrel.2008.04.020] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2007] [Revised: 04/17/2008] [Accepted: 04/24/2008] [Indexed: 10/22/2022]
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17
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Cork MJ, Danby S, Vasilopoulos Y, Moustafa M, MacGowan A, Varghese J, Duff GW, Tazi-Ahnini R, Ward SJ. Epidermal barrier dysfunctionin atopic dermatitis. SERIES IN DERMATOLOGICAL TREATMENT 2008. [DOI: 10.3109/9780203091449.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
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18
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Nicolazzo JA, Reed BL, Finnin BC. Buccal penetration enhancers--how do they really work? J Control Release 2005; 105:1-15. [PMID: 15894393 DOI: 10.1016/j.jconrel.2005.01.024] [Citation(s) in RCA: 130] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2004] [Accepted: 01/03/2005] [Indexed: 10/25/2022]
Abstract
Certain agents that increase drug delivery through the skin, including surfactants, bile salts, and fatty acids, have been shown to exert a similar effect on the buccal mucosa. These agents enhance skin permeability by interacting with and disrupting the ordered intercellular lipid lamellae within the keratinized stratum corneum, and it has been assumed that a similar mechanism of action occurs in the nonkeratinized buccal mucosa. However, the chemical and structural nature of the lipids present within the intercellular regions of the buccal mucosa is quite different to that found within the stratum corneum, and so extrapolation of results between these two tissues may be misleading. To assume that the mechanism of action of buccal penetration enhancers is based on the disruption of intercellular lipids may be erroneous, and may result in the inappropriate prediction that certain skin penetration enhancers will similarly enhance drug delivery through the buccal mucosa. The data available in the literature suggest that agents that enhance buccal penetration exert their effect by a mechanism other than by disruption of intercellular lipids. Rather, buccal penetration enhancement appears to result from agents being able to (a) increase the partitioning of drugs into the buccal epithelium, (b) extract (and not disrupt) intercellular lipids, (c) interact with epithelial protein domains, and/or (d) increase the retention of drugs at the buccal mucosal surface. The purpose of this review is to identify the major differences in the structural and chemical nature of the permeability barriers between the buccal mucosa and skin, to clarify the mechanisms of action of buccal penetration enhancers, and to identify the limitations of certain models that are used to assess the effect of buccal penetration enhancers.
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Affiliation(s)
- Joseph A Nicolazzo
- Department of Pharmaceutics, Monash University, 381 Royal Parade, Parkville, Victoria 3052, Australia
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Abstract
Surface epithelial cells, such as the epidermal keratinocyte, undergo a process of terminal cell differentiation that results in the construction of a multilayered epithelium. This epithelium functions to protect the organism from the environment. Transglutaminases, enzymes that catalyze the formation of isopeptide protein-protein cross-links, are key enzymes involved in the construction of this structure. This brief review will focus on the role of these enzymes in constructing the epidermal surface.
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Affiliation(s)
- Richard L Eckert
- Department of Physiology and Biophysics, Case School of Medicine, Cleveland, Ohio 44106, USA.
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Abstract
We propose that skin barrier morphogenesis may take place via a continuous and highly dynamic process of intersection-free membrane unfolding with a concomitant crystallization of the emerging multilamellar lipid structure representing the developing skin barrier. This implies that the trans-Golgi network and lamellar bodies of the uppermost stratum granulosum cells as well as the multilamellar lipid matrix of the intercellular space at the border zone between stratum granulosum and stratum corneum could be representations of one and the same continuous membrane structure. The profound difference between the earlier Landmann model and the membrane folding model presented here is that the Landmann model includes changes in membrane topology, whereas topology is kept constant during skin barrier formation according to the membrane folding model. The main advantages of the membrane folding model with respect to the Landmann model are the following: (i) smaller energy cost (involves no budding or fusion); (ii) conserves membrane continuity (preserves water compartmentalization and allows control hereof; membrane continuity essential for barrier function); (iii) allows meticulous control (the thermodynamics of the unfolding procedure are related to curvature energy); (iv) faster (milliseconds, as membrane unfolding basically represents a phase transition from cubic-like to lamellar morphology; involves no budding or fusion); (v) membrane folding between lamellar and cubic-like morphologies has been identified in numerous biologic systems; (vi) there is experimental evidence for an "extensive intracellular tubulo-reticular cisternal membrane system within the apical cytosol of the outermost stratum granulosum"; and (vii) may explain the reported plethora of forms, numbers, sizes and general appearances of "lamellar bodies" in transmission electron microscopy micrographs.
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Affiliation(s)
- L Norlén
- Department of Physics, University of Geneva, GAP-Biomedical, Geneva, Switzerland.
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Abstract
The purpose of this study was to investigate the effect of delipidization of the stratum corneum (SC) on the in vitro percutaneous absorption of hydrophilic solutes (i.e. water, urea, and inulin). Fourier transform infrared (FT-IR) spectroscopy was employed to study the extent of delipidization of porcine SC due to chloroform:methanol (2:1) (C:M (2:1)) treatments for various time periods. In vitro percutaneous absorption of [3H] water, [14C] urea, and [3H] inulin were studied through C:M (2:1) treated epidermis in Franz diffusion cells. There was a greater decrease in peak areas of the asymmetric and symmetric C-H stretching absorbances (i.e. increase in lipid extraction) with increasing exposure times of the SC with C:M (2:1). After 40-min treatment, asymmetric and symmetric C-H stretching peak area showed a decrease of 75.9 and 89.9%, respectively. The permeability coefficient of water, urea, and inulin increased with increasing lipid extraction. Enhancement in the permeability coefficient, through 40 min C:M (2:1) treated epidermis in comparison to the control, for water, urea, and inulin was 48.72, 215.65, and 3.90, respectively. Log (permeability coefficient) and log (mol. wt.) for test solutes and leuprolide acetate were found to be inversely related (R(2)=0.9974). In conclusion, this study implies that penetration enhancers that are safe and extract the SC lipids can be selected in order to enhance the percutaneous absorption of polar solutes through the skin.
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Affiliation(s)
- S K Rastogi
- Department of Pharmaceutical Sciences, College of Pharmacy, North Dakota State University, Fargo, ND 58105, USA
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van den Bergh BA, Vroom J, Gerritsen H, Junginger HE, Bouwstra JA. Interactions of elastic and rigid vesicles with human skin in vitro: electron microscopy and two-photon excitation microscopy. BIOCHIMICA ET BIOPHYSICA ACTA 1999; 1461:155-73. [PMID: 10556497 DOI: 10.1016/s0005-2736(99)00176-5] [Citation(s) in RCA: 106] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Interactions between vesicle formulations and human skin were studied, in vitro, in relation to their composition and elasticity. The skin ultrastructure was investigated using transmission electron microscopy (TEM), freeze-fracture electron microscopy (FFEM) and two-photon fluorescence microscopy (TPE). The main difference between the vesicle formulations was their elasticity. Elastic vesicle formulations contained bilayer forming surfactants/lipids and single-chain surfactant octaoxyethylenelaurate-ester (PEG-8-L), whereas rigid vesicles contained bilayer surfactants in combination with cholesterol. TEM results showed three types of interactions after non-occlusive application of elastic PEG-8-L containing vesicle formulations on human skin: (1) the presence of spherical lipid structures containing or surrounded by electron dense spots; (2) oligolamellar vesicles were observed between the corneocytes in the upper part of the stratum corneum; and (3) large areas containing lipids, surfactants and electron dense spots were observed deeper down into the stratum corneum. Furthermore, after treatment with vesicles containing PEG-8-L and a saturated C12-chain surfactant, small stacks of bilayers were found in intercellular spaces of the stratum corneum. Rigid vesicles affected only the most apical corneocytes to some extent. FFEM observations supported the TEM findings. Major morphological changes in the intercellular lipid bilayer structure were only observed after treatment with PEG-8-L containing elastic vesicles. TPE showed a distinct difference in penetration pathways after non-occlusive application of elastic or rigid vesicles. After treatment with elastic vesicles, thread-like channels were formed within the entire stratum corneum and the polygonal cell shape of corneocytes could not be distinguished. Fluorescent label incorporated in rigid vesicles was confined to the intercellular spaces of the upper 2-5 micrometer of the stratum corneum and the cell contours could still be distinguished.
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Affiliation(s)
- B A van den Bergh
- Department of Pharmaceutical Technology, Leiden Amsterdam Center for Drug Research, University of Leiden, 2300 RA, Leiden, Netherlands
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23
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Kempson SA, Campbell EH. A permeability barrier in the dorsal wall of the equine hoof capsule. Equine Vet J 1998:15-21. [PMID: 9932089 DOI: 10.1111/j.2042-3306.1998.tb05117.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The permeability barrier in the dorsal wall of the equine hoof capsule was studied by means of horseradish peroxidase (HRP) in 0.9 N saline solution as a water soluble tracer. Section were treated with 3'3'-diaminobenzidine tetrachloride (DAB) and before dissection the quality of the horn of feet from 10 horses was assessed and given a subjective grade as either good or poor. Blocks of tissue from each horse were left in either an oven at 60 degrees C or in water for 2 weeks before treatment in HRP, sectioning and DAB solution. Regions observed were i) outer surface, ii) outermost layers of the horn, iii) cut edge of the outer layer, iv) inner layer of horn, v) cut edge of the inner layer and vi) laminae. Horn deemed to be normal horn and of good 'quality' showed very slight penetration of HRP 3-5 cell layers deep in the outer layer. The cut edge of the outer layer of the wall of the 'normal' horn also showed minimal penetration of HRP through the intercellular spaces. The cut edge of the inner layers of the wall of normal, good quality horn showed penetration of the tracer up to 20 cell layers deep, with HRP in both the intercellular spaces and within the cells. In contrast, sections of horn from horses with brittle feet showed deep cracks in the outer surface into which the HRP had penetrated. Good quality horn showed no change in the position of the permeability barrier after soaking in water for 14 days, but the brittle horn showed an increase in permeability to HRP. In brittle horn, reaction product was seen deep within the section in the intercellular spaces of the intertubular horn only. Placing horn in an oven had no effect on the permeability barrier. The permeability barrier of the dorsal wall of the equine hoof capsule differs with the layer of the wall. Horn considered to be of poor quality had a weaker permeability barrier than horn of good quality.
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Affiliation(s)
- S A Kempson
- Department of Preclinical Veterinary Sciences, Royal (Dick) School of Veterinary Studies, University of Edinburgh, Summerhall, UK
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24
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Interactions between liposomes and human stratum corneum studied by freeze-substitution electron microscopy. Int J Pharm 1998. [DOI: 10.1016/s0378-5173(98)00039-8] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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25
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Wertz PW, van den Bergh B. The physical, chemical and functional properties of lipids in the skin and other biological barriers. Chem Phys Lipids 1998; 91:85-96. [PMID: 9569614 DOI: 10.1016/s0009-3084(97)00108-4] [Citation(s) in RCA: 169] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- P W Wertz
- Dows Institute, University of Iowa, Iowa City 52242, USA.
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26
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Abstract
Within the past 10 years, covalently bound lipids have been identified both in wool and hair and in epidermal stratum corneum. In hair, fatty acids, the most abundant of which is 18-methyleicosanoic acid, are attached via thioester linkages to protein at the outer surface of cuticle cells. This lipid layer, the fatty layer or F-layer, is thought to be of major significance in determining the surface properties of hair and wool. In epidermal stratum corneum, the covalently attached lipid has been identified as an omega-hydroxyceramide consisting of 30-through 34-carbon omega-hydroxyacids amide-linked to sphingosine bases. The hydroxyceramide molecules are attached to the outer surface of the cornified envelope through ester linkages, and provide a monolayer covering the outer surface of all corneocytes. This covalently bound lipid layer, or lipid envelope, interacts with free lipids and has a major influence on the organization of lipid lamellar structures in the intercellular space.
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Affiliation(s)
- P W Wertz
- Dows Institute, University of Iowa, Iowa City 52242, USA
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27
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Korting HC, Stolz W, Schmid MH, Maierhofer G. Interaction of liposomes with human epidermis reconstructed in vitro. Br J Dermatol 1995; 132:571-9. [PMID: 7748748 DOI: 10.1111/j.1365-2133.1995.tb08713.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Upon topical application of liposomes of the large unilamellar vesicle type to human epidermis reconstructed in vitro, there is a dose-dependent alteration of the morphology of both the stratum corneum and the living part of the epidermis. In particular, shrunken lipid droplets are found between corneocytes and keratinocytes. Sometimes, corneocytes show inclusions reminiscent of 'cholesterol crystals'. Corneocytes, moreover, show a decreased density. Both corneocytes of the various layers of the stratum corneum and keratinocytes belonging to the uppermost layer of the living epidermis show particularly osmophilic membranes, indicating lipid transfer. Intact liposomes or their remnants can sometimes be seen between corneocytes of the upper strata. The presence of liposomal lipid within the stratum corneum is supported by the presence of gold particles used as a marker. There is, however, no evidence for the uptake of intact liposomes by the living epidermis, or their passage through this compartment of the skin.
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Affiliation(s)
- H C Korting
- Department of Dermatology, Ludwig-Maximilians-University, München, Germany
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29
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Swartzendruber DC, Manganaro A, Madison KC, Kremer M, Wertz PW, Squier CA. Organization of the intercellular spaces of porcine epidermal and palatal stratum corneum: a quantitative study employing ruthenium tetroxide. Cell Tissue Res 1995; 279:271-6. [PMID: 7534652 DOI: 10.1007/bf00318483] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Previous studies have demonstrated that the intercellular spaces of the stratum corneum contain multilamellar lipid sheets with variable ultrastructure in addition to desmosomes or desmosomal remnants. The intercellular lamellae are thought to provide a permeability barrier whereas the desmosomes are responsible for cell-cell cohesion. In this study, transmission electron microscopy of RuO4-fixed tissue was used to compare the proportions of the intercellular spaces in epidermal and palatal stratum corneum occupied by desmosomes and by different patterns of lamellae. Desmosomes are more abundant in palatal than in epidermal stratum corneum (46.9 vs 15.0% length of intercellular space). In epidermis the most frequent lamellar arrangements involve 3 (23.5%) or 6 (24.2%) lucent bands with an alternating broad-narrow-broad pattern, whereas the most frequent lamellar arrangements in palatal tissue are 2 (17.2%) or 4 (10.5%) lucent bands of uniform width. Most of the nondesmosomal portion of the intercellular space in palatal stratum corneum was dilated and had elongated lamellae at the periphery and short disorganized lamellae and amorphous electron-dense material in the interior. It is concluded that the multilamellar lipid sheets are less extensive in palatal than in epidermal stratum corneum, which could explain the greater permeability of the palate.
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30
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Imakado S, Bickenbach JR, Bundman DS, Rothnagel JA, Attar PS, Wang XJ, Walczak VR, Wisniewski S, Pote J, Gordon JS. Targeting expression of a dominant-negative retinoic acid receptor mutant in the epidermis of transgenic mice results in loss of barrier function. Genes Dev 1995; 9:317-29. [PMID: 7867929 DOI: 10.1101/gad.9.3.317] [Citation(s) in RCA: 118] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
To study the effects of retinoic acid on the skin in vivo, we have subverted the activity of endogenous receptors by targeting expression of a dominant negative mutant of retinoic acid receptor alpha (RAR alpha) to the epidermis of transgenic mice. At birth, mice expressing the mutant RAR alpha transgene exhibited a marked phenotype of a red, shiny skin that was somewhat sticky to touch. Severely affected neonates died within 24 hr. Histological changes in the epidermis were subtle with the phenotypic stratum corneum appearing slightly thinner and more loosely packed than in controls. Electron microscopic studies revealed that lipid multilamellar structures were not present between cells in the stratum corneum of phenotypic mice. When assayed for transepidermal water loss, phenotypic skin lost water at a rate three times faster than controls, suggesting that neonatal lethality resulted from loss of epidermal barrier function. The absence of a functional lipid barrier in transgenic mice first became evident at E17 when lipids were extruded initially into the intercellular space. We have identified a potential pathway linking inhibition of retinoid signaling with disruption of the lipid barrier that involves peroxisome proliferator-activated receptors. This study documents the role of the retinoid signaling pathway in formation and maintenance of a functional epidermis and provides the first evidence that this is mediated in part by modulation of lipid metabolism.
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Affiliation(s)
- S Imakado
- Department of Cell Biology, Baylor College of Medicine, Houston, Texas 77030
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31
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35
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Abraham W, Downing DT. Lamellar structures formed by stratum corneum lipids in vitro: a deuterium nuclear magnetic resonance (NMR) study. Pharm Res 1992; 9:1415-21. [PMID: 1475227 DOI: 10.1023/a:1015802711440] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Hydrated lipid mixtures consisting of stratum corneum ceramides, cholesterol, specifically deuterated palmitic acid, and cholesteryl sulfate were investigated by solid-state 2H NMR spectroscopy at different temperatures. The mole ratio of cholesterol to ceramides was varied from 1 to 0. 2H NMR spectra from these mixtures showed powder patterns with quadrupolar splittings smaller than those obtained from control mixtures containing dipalmitoylphosphatidylcholine (DPPC) instead of the ceramides. This result is attributed to the rigid amide group of the ceramides, with a planar configuration, which could prevent close packing of the alpha-methylenes of the acyl chains. There was a gradual loss of symmetry in the powder pattern as the amount of cholesterol was decreased and the amount of ceramides (or DPPC) was increased concomitantly. The loss was more pronounced in the ceramide-containing samples. This phenomenon is interpreted as a decrease in the axial reorientation rate of the alpha-deuterated palmitic acid in the bilayers, presumably caused by the increased hydrogen bonding resulting from the high amount of hydroxyl-bearing ceramides. Spectra obtained at temperatures above 60 degrees C indicated the formation of a hexagonal phase (HII) by the ceramide-containing mixtures. Spectra of the omega-deuterated palmitic acid in the mixture containing 76 mol% ceramides and no cholesterol indicated phase separation into a more rigid phase and a more mobile phase in the temperature range of 25 to 60 degrees C. The bilayer configuration of lipids at 25 degrees C was confirmed by thin-section electron microscopy.
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Affiliation(s)
- W Abraham
- Marshall Dermatology Research Laboratories, Department of Dermatology, University of Iowa College of Medicine, Iowa City
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36
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Abstract
Abundant evidence points to an important role for epidermal lamellar body secretion in permeability-barrier maintenance. However, the response of the lamellar body secretory system to barrier disruption has not been examined. Hence, we examined the lamellar body secretory response at various points after acetone-induced barrier abrogation in hairless mice in air-exposed animals and those occluded with impermeable versus vapor-permeable membranes. Tape-stripped animals served as a control for chemical toxicity. Barrier perturbation with either acetone or tape stripping was followed by rapid secretion of lamellar body contents from the uppermost granular cell layer, leaving the cytosol largely devoid of lamellar bodies. The newly secreted lamellar body contents comprised pleated sheets (not "discs," as previously thought), which unfurled in the intercellular spaces at the granular-cornified cell interface. At this time (15-30 min), the basic unit structure of the lamellar bilayers in the mid-to-upper stratum corneum appeared disorganized and interspersed with large lacunae, reflecting solvent extraction. Nascent lamellar bodies began to reappear in the granular cell cytosol by 30 min and by 360 min the cells displayed a full complement of normal-appearing lamellar bodies. Between 60 and 360 min, the density of lamellar body sheets at the granular-cornified cell interface increased, whereas the membrane bilayers of the outer stratum corneum remained disorganized. New lamellar bilayer units first appeared in the lower stratum corneum between 60 and 180 min, as a result of the transformation of secreted lamellar body sheets and over time these lamellae appeared at more apical locations. Occlusion with a water vapor-impermeable but not a vapor-permeable membrane resulted in a) decreased quantities of lamellar bodies and lamellar body-derived intercellular products; b) formation of lamellar bodies with abnormal internal contents; c) inhibition of lamellar body secretion; and d) inhibition of transformation of lamellar body-derived sheets into lamellar bilayer units. These results demonstrate the central role of the lamellar body-secretory system in barrier repair and homeostasis.
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Affiliation(s)
- G K Menon
- Dermatology Service, Veterans Administration Medical Center, San Francisco, California 94121
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37
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Abstract
Stratum corneum has been isolated by tryptic digestion of porcine epidermis and palatal epithelium, and the lipid concentrations and compositions have been compared by thin-layer chromatography in conjunction with photodensitometry. Palatal stratum corneum contained 47 +/- 6 micrograms lipid/mg tissue or 115 +/- 16 micrograms lipid per cm2 of stratum corneum surface, whereas epidermal stratum corneum contained 105 +/- 17 micrograms lipid/mg tissue or 135 +/- 16 micrograms/cm2. The difference in total lipid content does not account for the tenfold higher permeability constant for the permeation of water through the former tissue compared to the latter; therefore, the difference in permeability must be based on differences in lipid composition. In this regard, palatal stratum corneum includes 12.1% phospholipids, although phospholipids were undetected in epidermal stratum corneum. Differences in the content and location of non-polar liquid-phase lipids may also be of significance for permeability. Other factors that may contribute to the greater permeability of the palatal horny layer relative to epidermal stratum corneum include generally lower proportions of cholesterol, fatty acids, and ceramides, a dramatically lower proportion of the linoleate-containing acylceramide, and a tenfold lower content of covalently bound lipids associated with the corneocyte envelope.
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Affiliation(s)
- P W Wertz
- Dows Institute, College of Dentistry, University of Iowa, Iowa City 52242
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38
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Brysk MM, Rajaraman S. Cohesion and desquamation of epidermal stratum corneum. PROGRESS IN HISTOCHEMISTRY AND CYTOCHEMISTRY 1992; 25:1-53. [PMID: 1470681 DOI: 10.1016/s0079-6336(11)80062-8] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
This article attempts to provide a comprehensive review on the roles of various classes of molecules in the cohesion and desquamation of the stratum corneum. In the first part of this monograph we review the field of epidermal differentiation in vivo and vitro, describing the expression and functions of a number of key structural molecules that characterize the process. In the second part we emphasize terminal differentiation and the biogenesis of the stratum corneum. The stratum corneum is a cell layer unique to fully differentiated squamous epithelia such as skin. While it is a dead stratum, it nevertheless is in a homeostatic process of continual shedding and renewal in synchrony with basal cell replication. It is also a degradative layer containing many proteinases and glycosidases in which a variety of intracellular and intercellular macromolecules are degraded. We highlight the molecules localized within the intercorneal matrix that are most likely to play a role in cohesion and desquamation, including: glycoproteins, lipids and enzymes. Because it is difficult to study the stratum corneum and desquamation in the native tissue, we discuss a number of model systems that have been used. The stratum corneum can be dispersed into single squames in different ways; these include mechanical dispersion as well as agents such as detergents and enzymes. The solubilized molecules and the structures remaining can then be studied as to their specific roles in desquamation. Using this approach it is possible to reconstitute multilayered structures that resemble a real stratum corneum. We have shown that glycoproteins play a key role in squame reaggregation and that this process can be modulated with amino sugars in a lectin-like fashion. Cohesion and desquamation can also be studied in tissue culture. Depending on the culture system, the extent of terminal differentiation and squame accumulation varies. Yet desquamation does not normally occur. It can be induced however by the inclusion of exogenous agents such as IFN-gamma which are found in the native epidermis but are absent in vitro. Modulation of desquamation by other exogenous agents is likely to yield further knowledge of how shedding occurs in vivo. Insight has also come from studies of scaling skin disorders. The glycoprotein and lipid profiles are altered in the stratum corneum in many diseases of aberrant terminal differentiation. A number of abnormalities in the levels of cytokines and growth factors have also been reported in the lesional tissue of such diseases.(ABSTRACT TRUNCATED AT 400 WORDS)
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Affiliation(s)
- M M Brysk
- Department of Dermatology, University of Texas Medical Branch, Galveston 77550
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Abstract
The delivery of drugs via the mucous membranes lining the oral cavity (i.e., sublingual and buccal), with consideration of both systemic delivery and local therapy, is reviewed in this paper. The structure and composition of the mucosae at different sites in the oral cavity, factors affecting mucosal permeability, penetration enhancement, selection of appropriate experimental systems for studying mucosal permeability, and formulation factors relevant to the design of systems for oral mucosal delivery are discussed. Sublingual delivery gives rapid absorption and good bioavailability for some small permeants, although this site is not well suited to sustained-delivery systems. The buccal mucosa, by comparison, is considerably less permeable, but is probably better suited to the development of sustained-delivery systems. For these reasons, the buccal mucosa may have potential for delivering some of the growing number of peptide drugs, particularly those of low molecular weight, high potency, and/or long biological half-life. Development of safe and effective penetration enhancers will further expand the utility of this route. Local delivery is a relatively poorly studied area; in general, it is governed by many of the same considerations that apply to systemic delivery.
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Affiliation(s)
- D Harris
- School of Pharmacy, University of Wisconsin-Madison 53706
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40
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41
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Abstract
Non-human mammalian pheromones are commonly used as perfumery ingredients. The actual purpose for using these compounds is as a fixative or carrier for the odor effects of the other ingredients as well as a contributor, in part, to the over-all scent of the perfume. Although such materials are used for their fixative and odor qualities rather than their pheromonal effects, perfumes are generally marketed as having the ability to enhance sexual attractiveness. While providing a scent may elicit a positive pleasant response, this should not be confused with a pheromone response. The attractive effect of perfumes is principally related to the effect of the pleasant scent. A more logical approach would be to use human pheromones which, for humans, are both more natural and more effective as true sensual attractants. It seems likely that implementation of this approach will constitute an important paradigm in the perfume industry as perfumery moves from the realm of art to that of science.
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42
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Abraham W, Downing DT. Deuterium NMR investigation of polymorphism in stratum corneum lipids. BIOCHIMICA ET BIOPHYSICA ACTA 1991; 1068:189-94. [PMID: 1911830 DOI: 10.1016/0005-2736(91)90209-q] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The intercellular lipid lamellae of stratum corneum constitute the major barrier to percutaneous penetration. Deuterium magnetic resonance and freeze-fracture electron microscopic investigation of hydrated lipid mixtures consisting of ceramides, cholesterol, palmitic acid and cholesteryl sulfate and approximating the stratum corneum intercellular lipid composition, revealed thermally induced polymorphism. The transition temperature of bilayer to hexagonal transition decreased as the ratio of cholesterol to ceramides in these mixtures was lowered. Lipid mixtures in which the stratum corneum ceramides were replaced by synthetic dipalmitoylphosphatidylcholine did not show any polymorphism throughout the temperature range used in the present study. The ability of the ceramide-containing samples to form hexagonal structures establishes a plausible mechanism for the assembly of the stratum corneum intercellular lamellae during the final stages of epidermal differentiation. Also, the bilayer to hexagonal phase transition of these nonpolar lipid mixtures could be used to enhance the penetration of drugs through skin.
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Affiliation(s)
- W Abraham
- Marshall Dermatology Research Laboratories, Department of Dermatology, University of Iowa College of Medicine, Iowa City
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43
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Tarugi P, Albertazzi L, Nicolini S, Ottaviani E, Calandra S. Synthesis and secretion of apolipoprotein A-I by chick skin. J Biol Chem 1991. [DOI: 10.1016/s0021-9258(20)89507-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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Feingold KR, Man MQ, Proksch E, Menon GK, Brown BE, Elias PM. The lovastatin-treated rodent: a new model of barrier disruption and epidermal hyperplasia. J Invest Dermatol 1991; 96:201-9. [PMID: 1991980 DOI: 10.1111/1523-1747.ep12461153] [Citation(s) in RCA: 99] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Recent studies have linked epidermal cholesterol synthesis with maintenance of the permeability barrier. To assess directly the importance of cholesterol synthesis, we applied lovastatin, a potent inhibitor of cholesterol synthesis, to hairless mouse skin. Transepidermal water loss (TEWL) began to increase after four to six daily applications. Co-application of cholesterol blocked the expected increase in TEWL, demonstrating the importance of cholesterol for development of the lesion. The histology of lovastatin-treated skin revealed epidermal hyperplasia, accompanied by accelerated DNA synthesis. Whereas cholesterol synthesis initially was reduced in lovastatin-treated epidermis, with further treatment cholesterol synthesis normalized, while fatty acid synthesis accelerated greatly. Although the total free sterol content of lovastatin-treated epidermis remained normal, the fatty acid content increased coincident with barrier disruption. Finally, morphologic abnormalities of both lamellar body structure and their deposited, intercellular contents occurred coincident with the emerging biochemical abnormalities. Thus, the abnormal barrier function in this model can be ascribed to an initial inhibition of epidermal sterol synthesis followed by an alteration in cholesterol and fatty acid synthesis, leading to an imbalance in stratum corneum lipid composition and abnormal membrane bilayer structure.
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Affiliation(s)
- K R Feingold
- Dermatology Service, Veterans Administration Medical Center, San Francisco, California 94121
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45
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Affiliation(s)
- J Brod
- Department of Biology, L'Oreal Research Laboratories, Aulnay-sous-Bois, France
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46
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Affiliation(s)
- D R Friend
- Controlled Release and Biomedical Polymers Department, SRI International, Menlo Park, California 94025
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47
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Elias PM, Menon GK. Structural and lipid biochemical correlates of the epidermal permeability barrier. ADVANCES IN LIPID RESEARCH 1991; 24:1-26. [PMID: 1763710 DOI: 10.1016/b978-0-12-024924-4.50005-5] [Citation(s) in RCA: 425] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
As reviewed in this article, the stratum corneum must now be accorded the respect due to a structurally heterogeneous tissue possessing a selected array of enzymatic activity. The sequestration of lipids to intercellular domains and their organization into a unique multilamellar system have broad implications for permeability barrier function, water retention, desquamation, and percutaneous drug delivery. Yet, the functions and organization of specific lipid species in this membrane system are still unknown. Certain novel insights have resulted from comparative studies in avians and marine mammals. Further elucidation of the molecular architecture and interactions of lipid and nonlipid components of the stratum corneum intercellular domains will be a prerequisite for a comprehensive understanding of stratum corneum function.
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Affiliation(s)
- P M Elias
- Dermatology Service, Veterans Administration Medical Center, San Francisco, California 94121
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Chang F, Wertz PW, Squier CA. Comparison of glycosidase activities in epidermis, palatal epithelium and buccal epithelium. COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY. B, COMPARATIVE BIOCHEMISTRY 1991; 100:137-9. [PMID: 1756616 DOI: 10.1016/0305-0491(91)90096-v] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
1. beta-Glucosidase, alpha-glucosidase, beta-galactosidase and alpha-mannosidase were measured in epidermis, palatal and buccal epithelium of the pig (Sus scrofa). 2. All three epithelia contained similar alpha-mannosidase activity (1.7-3.2 nmol mg tissue-1 hr-1 at pH 4), and none contained significant alpha-glucosidase. 3. Specific activity of beta-glucosidase was high (9-13 nmol mg tissue-1 hr-1 at pH 4) in epidermis and palate, but activity was low (less than 2 nmol mg tissue-1 hr-1) in buccal epithelium. 4. Only epidermis contained a high level of beta-galactosidase (5.8 nmol mg tissue-1 hr-1). 5. Differences in glycosidase profiles may underlie differences in permeability barrier properties in these epithelia.
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Affiliation(s)
- F Chang
- Dows Institute for Dental Research, University of Iowa, Iowa City 52242
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Squier CA, Cox P, Wertz PW. Lipid content and water permeability of skin and oral mucosa. J Invest Dermatol 1991; 96:123-6. [PMID: 1987287 DOI: 10.1111/1523-1747.ep12515931] [Citation(s) in RCA: 117] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
It has been claimed that total lipid content may be the critical factor determining the water permeability of skin. The present study examined this relationship in various oral epithelia and epidermis. Epithelia was heat separated from specimens of porcine skin, gingiva, buccal mucosa, palate, and floor of mouth. Lipids were solvent extracted and separated by thin layer chromatography with appropriate standards. The plates were sprayed with sulfuric acid and charred, and the concentration of lipids was determined by densitometry as mg lipid/gm tissue dry weight. Permeability constants were determined for each tissue by using tritiated water in perfusion chambers. When these values were compared over all regions, total lipid did not appear to be related to the permeability of these tissues. However, in the keratinized regions (epidermis, gingiva, and palate) a lower water permeability was related to a greater content of total lipid, nonpolar lipid, ceramide, and glucosylceramide. In non-keratinized tissues, a lower permeability corresponded to increased amounts of an unidentified glycosylceramide. The role of lipid in the permeability barrier of these tissues was further demonstrated by extracting specimens of skin and oral mucosa with chloroform/methanol and then determining Kp values; in both tissue regions, there was a significant increase in water permeability. Thus, although lipid is a component of the water permeability barrier in both skin and oral mucosa, different lipid components subserve this function in keratinized and non-keratinized tissues.
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Affiliation(s)
- C A Squier
- Dows Institute for Dental Research, University of Iowa College of Dentistry, Iowa City 52242
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Audus KL, Bartel RL, Hidalgo IJ, Borchardt RT. The use of cultured epithelial and endothelial cells for drug transport and metabolism studies. Pharm Res 1990; 7:435-51. [PMID: 2195492 DOI: 10.1023/a:1015800312910] [Citation(s) in RCA: 218] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
In an effort to develop novel strategies for delivery of drug candidates arising from rational drug design and recombinant DNA technology, pharmaceutical scientists have begun to employ the techniques of cell culture to study drug transport and metabolism at specific biological barriers. This review describes some of the general factors that should be considered in developing a cell culture model for transport studies and metabolism studies. In addition, we review in detail the recent progress that has been made in establishing, validating, and using cell cultures of epithelial barriers (e.g., cells that constitute the intestinal, rectal, buccal, sublingual, nasal, and ophthalmic mucosa as well as the epidermis of the skin) and the endothelial barriers (e.g., brain microvessel endothelial cells).
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Affiliation(s)
- K L Audus
- Department of Pharmaceutical Chemistry, University of Kansas, Lawrence 66045
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