Specific binding of Clostridium perfringens enterotoxin fragment to Claudin-b and modulation of zebrafish epidermal barrier.

PubMed

Zhang, Jingjing; Ni, Chen; Yang, Zhenguo; Piontek, Anna; Chen, Huapu; Wang, Sijie; Fan, Yiming; Qin, Zhihai; Piontek, Joerg

2015-08-01

Claudins (Cldn) are the major components of tight junctions (TJs) sealing the paracellular cleft in tissue barriers of various organs. Zebrafish Cldnb, the homolog of mammalian Cldn4, is expressed at epithelial cell-cell contacts and is important for regulating epidermal permeability. The bacterial toxin Clostridium perfringens enterotoxin (CPE) has been shown to bind to a subset of mammalian Cldns. In this study, we used the Cldn-binding C-terminal domain of CPE (194-319 amino acids, cCPE 194-319 ) to investigate its functional role in modulating zebrafish larval epidermal barriers. In vitro analyses show that cCPE 194-319 removed Cldn4 from epithelial cells and disrupted the monolayer tightness, which could be rescued by the removal of cCPE 194-319. Incubation of zebrafish larvae with cCPE 194-319 removed Cldnb specifically from the epidermal cell membrane. Dye diffusion analysis with 4-kDa fluorescent dextran indicated that the permeability of the epidermal barrier increased due to cCPE 194-319 incubation. Electron microscopic investigation revealed reversible loss of TJ integrity by Cldnb removal. Collectively, these results suggest that cCPE 194-319 could be used as a Cldnb modulator to transiently open the epidermal barrier in zebrafish. In addition, zebrafish might be used as an in vivo system to investigate the capability of cCPE to enhance drug delivery across tissue barriers. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Skin Barrier Development Depends on CGI-58 Protein Expression during Late-Stage Keratinocyte Differentiation

PubMed Central

Grond, Susanne; Radner, Franz P.W.; Eichmann, Thomas O.; Kolb, Dagmar; Grabner, Gernot F.; Wolinski, Heimo; Gruber, Robert; Hofer, Peter; Heier, Christoph; Schauer, Silvia; Rülicke, Thomas; Hoefler, Gerald; Schmuth, Matthias; Elias, Peter M.; Lass, Achim; Zechner, Rudolf; Haemmerle, Guenter

2017-01-01

Adipose triglyceride lipase (ATGL) and its coactivator comparative gene identification-58 (CGI-58) are limiting in cellular triglyceride catabolism. Although ATGL deficiency is compatible with normal skin development, mice globally lacking CGI-58 die postnatally and exhibit a severe epidermal permeability barrier defect, which may originate from epidermal and/or peripheral changes in lipid and energy metabolism. Here, we show that epidermis-specific disruption of CGI-58 is sufficient to provoke a defect in the formation of a functional corneocyte lipid envelope linked to impaired ω-O-acylceramide synthesis. As a result, epidermis-specific CGI-58-deficient mice show severe skin dysfunction, arguing for a tissue autonomous cause of disease development. Defective skin permeability barrier formation in global CGI-58-deficient mice could be reversed via transgenic restoration of CGI-58 expression in differentiated but not basal keratinocytes suggesting that CGI-58 is essential for lipid metabolism in suprabasal epidermal layers. The compatibility of ATGL deficiency with normal epidermal function indicated that CGI-58 may stimulate an epidermal triglyceride lipase beyond ATGL required for the adequate provision of fatty acids as a substrate for ω-O-acylceramide synthesis. Pharmacological inhibition of ATGL enzyme activity similarly reduced triglyceride-hydrolytic activities in wild-type and CGI-58 overexpressing epidermis implicating that CGI-58 participates in ω-O-acylceramide biogenesis independent of its role as a coactivator of epidermal triglyceride catabolism. PMID:27725204

Vibrational spectroscopy and microscopic imaging: novel approaches for comparing barrier physical properties in native and human skin equivalents.

PubMed

Yu, Guo; Zhang, Guojin; Flach, Carol R; Mendelsohn, Richard

2013-06-01

Vibrational spectroscopy and imaging have been used to compare barrier properties in human skin, porcine skin, and two human skin equivalents, Epiderm 200X with an enhanced barrier and Epiderm 200 with a normal barrier. Three structural characterizations were performed. First, chain packing and conformational order were compared in isolated human stratum corneum (SC), isolated porcine SC, and in the Epiderm 200X surface layers. The infrared (IR) spectrum of isolated human SC revealed a large proportion of orthorhombically packed lipid chains at physiological temperatures along with a thermotropic phase transition to a state with hexagonally packed chains. In contrast, the lipid phase at physiological temperatures in both porcine SC and in Epiderm 200X, although dominated by conformationally ordered chains, lacked significant levels of orthorhombic subcell packing. Second, confocal Raman imaging of cholesterol bands showed extensive formation of cholesterol-enriched pockets within the human skin equivalents (HSEs). Finally, IR imaging tracked lipid barrier dimensions as well as the spatial disposition of ordered lipids in human SC and Epiderm 200X. These approaches provide a useful set of experiments for exploring structural differences between excised human skin and HSEs, which in turn may provide a rationale for the functional differences observed among these preparations.

Cellular responses to disruption of the permeability barrier in a three-dimensional organotypic epidermal model

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ajani, Gati; Sato, Nobuyuki; Mack, Judith A.

2007-08-15

Repeated injury to the stratum corneum of mammalian skin (caused by friction, soaps, or organic solvents) elicits hyperkeratosis and epidermal thickening. Functionally, these changes serve to restore the cutaneous barrier and protect the organism. To better understand the molecular and cellular basis of this response, we have engineered an in vitro model of acetone-induced injury using organotypic epidermal cultures. Rat epidermal keratinocytes (REKs), grown on a collagen raft in the absence of any feeder fibroblasts, developed all the hallmarks of a true epidermis including a well-formed cornified layer. To induce barrier injury, REK cultures were treated with intermittent 30-s exposuresmore » to acetone then were fixed and paraffin-sectioned. After two exposures, increased proliferation (Ki67 and BrdU staining) was observed in basal and suprabasal layers. After three exposures, proliferation became confined to localized buds in the basal layer and increased terminal differentiation was observed (compact hyperkeratosis of the stratum corneum, elevated levels of K10 and filaggrin, and heightened transglutaminase activity). Thus, barrier disruption causes epidermal hyperplasia and/or enhances differentiation, depending upon the extent and duration of injury. Given that no fibroblasts are present in the model, the ability to mount a hyperplastic response to barrier injury is an inherent property of keratinocytes.« less

Integrin-Linked Kinase Is Indispensable for Keratinocyte Differentiation and Epidermal Barrier Function.

PubMed

Sayedyahossein, Samar; Rudkouskaya, Alena; Leclerc, Valerie; Dagnino, Lina

2016-02-01

A functional permeability barrier is essential to prevent the passage of water and electrolytes, macromolecules, and pathogens through the epidermis. This is accomplished in terminally differentiated keratinocytes through formation of a cornified envelope and the assembly of tight intercellular junctions. Integrin-linked kinase (ILK) is a scaffold protein essential for hair follicle morphogenesis and epidermal attachment to the basement membrane. However, the biological functions of ILK in differentiated keratinocytes remain poorly understood. Furthermore, whether ILK is implicated in keratinocyte differentiation and intercellular junction formation has remained an unresolved issue. Here we describe a pivotal role for ILK in keratinocyte differentiation responses to increased extracellular Ca(2+), regulation of adherens and tight junction assembly, and the formation of an outside-in permeability barrier toward macromolecules. In the absence of ILK, the calcium sensing receptor, E-cadherin, and ZO-1 fail to translocate to the cell membrane, through mechanisms that involve abnormalities in microtubules and in RhoA activation. In situ, ILK-deficient epidermis exhibits reduced tight junction formation and increased outside-in permeability to a dextran tracer, indicating reduced barrier properties toward macromolecules. Therefore, ILK is an essential component of keratinocyte differentiation programs that contribute to epidermal integrity and the establishment of its barrier properties. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

Local Burn Injury Promotes Defects in the Epidermal Lipid and Antimicrobial Peptide Barriers in Human Autograft Skin and Burn Margin: Implications for Burn Wound Healing and Graft Survival

PubMed Central

Plichta, Jennifer K.; Holmes, Casey J.; Gamelli, Richard L.; Radek, Katherine A.

2016-01-01

Burn injury increases the risk of morbidity and mortality by promoting severe hemodynamic shock and risk for local or systemic infection. Graft failure due to poor wound healing or infection remains a significant problem for burn subjects. The mechanisms by which local burn injury compromises the epithelial antimicrobial barrier function in the burn margin, containing the elements necessary for healing of the burn site, and in distal unburned skin, which serves as potential donor tissue, are largely unknown. The objective of this study was to establish defects in epidermal barrier function in human donor skin and burn margin, in order to identify potential mechanisms that may lead to graft failure and/or impaired burn wound healing. In the present study, we established that epidermal lipids and respective lipid synthesis enzymes were significantly reduced in both donor skin and burn margin. We further identified diverse changes in the gene expression and protein production of several candidate skin antimicrobial peptides (AMPs) in both donor skin and burn margin. These results also parallel changes in cutaneous AMP activity against common burn wound pathogens, aberrant production of epidermal proteases known to regulate barrier permeability and AMP activity, and greater production of pro-inflammatory cytokines known to be induced by AMPs. These findings suggest that impaired epidermal lipid and AMP regulation could contribute to graft failure and infectious complications in subjects with burn or other traumatic injury. PMID:27183442

Peeling off the genetics of atopic dermatitis-like congenital disorders.

PubMed

Samuelov, Liat; Sprecher, Eli

2014-10-01

The epidermis forms during the course of a complex differentiation process known as cornification, which culminates with the formation of the epidermal barrier. The epidermal barrier serves as a vital line of defense against the environment and mainly consists of 3 elements: intracellular keratin filaments, intercellular lipids, and the cornified cell envelope. Adequate epidermal barrier function is also critically dependent on normal shedding of terminally differentiated keratinocytes, a process termed desquamation, which requires the dissolution of cell-cell junctions in the upper granular layers. Although much has been learned about epidermal differentiation through the deciphering of the molecular basis of various cornification disorders, less is currently known about the mechanisms regulating epidermal desquamation and disorders resulting from disruption of this process. Netherton syndrome, peeling skin syndrome type B, and skin dermatitis--multiple severe allergies--metabolic wasting syndrome are 3 autosomal recessive conditions resulting from aberrant regulation of epidermal desquamation. The deciphering of their pathogenesis has not only broadened our understanding of this process but has also shed new light on clinical and mechanistic links between allergic reactions and abnormal desquamation, substantiating the notion that allergic manifestations might, under some circumstances, be the sole consequence of a primary epidermal defect. Copyright © 2014 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.

Clinical characteristics and epidermal barrier function of papulopustular rosacea: A comparison study with acne vulgaris.

PubMed

Zhou, Maosong; Xie, Hongfu; Cheng, Lin; Li, Ji

2016-01-01

To evaluate the clinical characteristics and epidermal barrier function of papulopustular rosacea by comparing with acne vulgaris. Four hundred and sixty-three papulopustular rosacea patients and four hundred and twelve acne vulgaris patients were selected for the study in Xiangya Hospital of Central South University from March 2015 to May 2016. They were analyzed for major facial lesions, self-conscious symptoms and epidermal barrier function. Erythema, burning, dryness and itching presented in papulopustular rosacea patients were significantly higher than that in acne vulgaris patients ( P <0.001). The clinical scores of erythema, burning, dryness and itching in papulopustular rosacea patients were significantly higher than those in acne vulgaris patients ( P <0.001). The water content of the stratum cornuem and skin surface lipid level were both significantly lower in papulopustular rosacea patients than that of the acne vulgaris patients ( P <0.001) and healthy subjects ( P <0.001); Water content of the stratum cornuem and skin surface lipid level were higher in acne vulgaris patients in comparison with that of healthy subjects ( P >0.05, P <0.001; respectively). Transepidermal water loss was significantly higher in papulopustular rosacea patients than that of acne vulgaris patients and healthy subjects ( P <0.001); transepidermal water loss was lower in skin of acne vulgaris patients than that of healthy subjects ( P <0.001). Erythema, burning, dryness and itching are the characteristics of papulopustular rosacea, which makes it different from acne vulgaris. The epidermal barrier function was damaged in papulopustular rosacea patients while not impaired in that of acne vulgaris patients.

Improvement of hydration and epidermal barrier function in human skin by a novel compound isosorbide dicaprylate.

PubMed

Chaudhuri, R K; Bojanowski, K

2017-10-01

The study involved the synthesis of a novel derivative of caprylic acid - isosorbide dicaprylate (IDC) - and the evaluation of its potential in improving water homoeostasis and epidermal barrier function in human skin. The effect of IDC on gene expression was assayed in skin organotypic cultures by DNA microarrays. The results were then confirmed for a few key genes by quantitative PCR, immuno- and cytochemistry. Final validation of skin hydration properties was obtained by four separate clinical studies. Level of hydration was measured by corneometer either by using 2% IDC lotion alone vs placebo or in combination with 2% glycerol lotion vs 2% glycerol only. A direct comparison in skin hydration between 2% IDC and 2% glycerol lotions was also carried out. The epidermal barrier function improvement was assessed by determining changes in transepidermal water loss (TEWL) on the arms before and after treatment with 2% IDC lotion versus placebo. IDC was found to upregulate the expression of AQP3, CD44 and proteins involved in keratinocyte differentiation as well as the formation and function of stratum corneum. A direct comparison between 2% IDC versus 2% glycerol lotions revealed a three-fold advantage of IDC in providing skin hydration. Severely dry skin treated with 2% IDC in combination with 2% glycerol showed 133% improvement, whereas 35% improvement was observed with moderately dry human skin. Topical isosorbide dicaprylate favourably modulates genes involved in the maintenance of skin structure and function, resulting in superior clinical outcomes. By improving skin hydration and epidermal permeability barrier, it offers therapeutic applications in skin ageing. © 2017 Society of Cosmetic Scientists and the Société Française de Cosmétologie.

Epidermal Transglutaminase (TGase 3) Is Required for Proper Hair Development, but Not the Formation of the Epidermal Barrier

PubMed Central

John, Susan; Thiebach, Lars; Frie, Christian; Mokkapati, Sharada; Bechtel, Manuela; Nischt, Roswitha; Rosser-Davies, Sally; Paulsson, Mats; Smyth, Neil

2012-01-01

Transglutaminases (TGase), a family of cross-linking enzymes present in most cell types, are important in events as diverse as cell-signaling and matrix stabilization. Transglutaminase 1 is crucial in developing the epidermal barrier, however the skin also contains other family members, in particular TGase 3. This isoform is highly expressed in the cornified layer, where it is believed to stabilize the epidermis and its reduction is implicated in psoriasis. To understand the importance of TGase 3 in vivo we have generated and analyzed mice lacking this protein. Surprisingly, these animals display no obvious defect in skin development, no overt changes in barrier function or ability to heal wounds. In contrast, hair lacking TGase 3 is thinner, has major alterations in the cuticle cells and hair protein cross-linking is markedly decreased. Apparently, while TGase 3 is of unique functional importance in hair, in the epidermis loss of TGase 3 can be compensated for by other family members. PMID:22496784

Altered epidermal lipid processing and calcium distribution in the KID syndrome mouse model Cx26S17F.

PubMed

Bosen, Felicitas; Celli, Anna; Crumrine, Debra; vom Dorp, Katharina; Ebel, Philipp; Jastrow, Holger; Dörmann, Peter; Winterhager, Elke; Mauro, Theodora; Willecke, Klaus

2015-07-08

The keratitis-ichthyosis-deafness (KID) syndrome is caused by mutations in the gap junctional channel protein connexin 26 (Cx26), among them the mutation Cx26S17F. Heterozygous Cx26S17F mice resemble the human KID syndrome, i.e. exhibiting epidermal hyperplasia and hearing impairments. Newborn Cx26S17F mice show a defective epidermal water barrier as well as altered epidermal lipid secretion and location. Linoleoyl ω-esterified ceramides are strongly decreased on the skin surface of Cx26S17F mice. Moreover, the epidermal calcium gradient is altered in the mutant mice. These alterations may be caused by an abnormal Cx26S17F channel function that leads to a defective epidermal water barrier, which in turn may trigger the hyperproliferation seen in the KID syndrome. Copyright © 2015 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.

Serine Proteolytic Pathway Activation Reveals an Expanded Ensemble of Wound Response Genes in Drosophila

PubMed Central

Patterson, Rachel A.; Juarez, Michelle T.; Hermann, Anita; Sasik, Roman; Hardiman, Gary; McGinnis, William

2013-01-01

After injury to the animal epidermis, a variety of genes are transcriptionally activated in nearby cells to regenerate the missing cells and facilitate barrier repair. The range and types of diffusible wound signals that are produced by damaged epidermis and function to activate repair genes during epidermal regeneration remains a subject of very active study in many animals. In Drosophila embryos, we have discovered that serine protease function is locally activated around wound sites, and is also required for localized activation of epidermal repair genes. The serine protease trypsin is sufficient to induce a striking global epidermal wound response without inflicting cell death or compromising the integrity of the epithelial barrier. We developed a trypsin wounding treatment as an amplification tool to more fully understand the changes in the Drosophila transcriptome that occur after epidermal injury. By comparing our array results with similar results on mammalian skin wounding we can see which evolutionarily conserved pathways are activated after epidermal wounding in very diverse animals. Our innovative serine protease-mediated wounding protocol allowed us to identify 8 additional genes that are activated in epidermal cells in the immediate vicinity of puncture wounds, and the functions of many of these genes suggest novel genetic pathways that may control epidermal wound repair. Additionally, our data augments the evidence that clean puncture wounding can mount a powerful innate immune transcriptional response, with different innate immune genes being activated in an interesting variety of ways. These include puncture-induced activation only in epidermal cells in the immediate vicinity of wounds, or in all epidermal cells, or specifically in the fat body, or in multiple tissues. PMID:23637905

The Functions of Grainy Head-Like Proteins in Animals and Fungi and the Evolution of Apical Extracellular Barriers

PubMed Central

Paré, Adam; Kim, Myungjin; Juarez, Michelle T.; Brody, Stuart; McGinnis, William

2012-01-01

The Grainy head (GRH) family of transcription factors are crucial for the development and repair of epidermal barriers in all animals in which they have been studied. This is a high-level functional conservation, as the known structural and enzymatic genes regulated by GRH proteins differ between species depending on the type of epidermal barrier being formed. Interestingly, members of the CP2 superfamily of transcription factors, which encompasses the GRH and LSF families in animals, are also found in fungi – organisms that lack epidermal tissues. To shed light on CP2 protein function in fungi, we characterized a Neurospora crassa mutant lacking the CP2 member we refer to as grainy head-like (grhl). We show that Neurospora GRHL has a DNA-binding specificity similar to that of animal GRH proteins and dissimilar to that of animal LSF proteins. Neurospora grhl mutants are defective in conidial-spore dispersal due to an inability to remodel the cell wall, and we show that grhl mutants and the long-known conidial separation-2 (csp-2) mutants are allelic. We then characterized the transcriptomes of both Neurospora grhl mutants and Drosophila grh mutant embryos to look for similarities in the affected genes. Neurospora grhl appears to play a role in the development and remodeling of the cell wall, as well as in the activation of genes involved in defense and virulence. Drosophila GRH is required to activate the expression of many genes involved in cuticular/epidermal-barrier formation. We also present evidence that GRH plays a role in adult antimicrobial defense. These results, along with previous studies of animal GRH proteins, suggest the fascinating possibility that the apical extracellular barriers of some animals and fungi might share an evolutionary connection, and that the formation of physical barriers in the last common ancestor was under the control of a transcriptional code that included GRH-like proteins. PMID:22590528

Sun-Induced Changes in Stratum Corneum Function Are Gender and Dose Dependent in a Chinese Population

PubMed Central

Liu, Z.; Fluhr, J.W.; Song, S.P.; Sun, Z.; Wang, H.; Shi, Y.J.; Elias, P.M.; Man, M.-Q.

2010-01-01

Previous studies have demonstrated that UVB radiation changes the epidermal permeability barrier and stratum corneum (SC) hydration. It is well known that sun exposure causes erythema, sunburn and melanoma. However, whether daily sun exposure alters SC integrity and epidermal permeability barrier function is largely unknown, especially in Chinese subjects. In the present study, we assess the SC integrity, SC hydration and epidermal permeability barrier function following various doses of sun exposure. A total of 258 subjects (124 males and 134 females) aged 18–50 years were enrolled. A multifunctional skin physiology monitor (Courage & Khazaka MPA5) was used to measure SC hydration and transepidermal water loss (TEWL) on the forearms. In males, basal TEWL was higher with higher doses of sun exposure than with lower doses and control, whereas in females, basal TEWL was higher with lower doses of sun exposure than with higher doses and control. In the group with higher doses of sun exposure, TEWL in females was significantly lower than that in males. The barrier recovery was faster in females than in males in both control and lower-dose groups. In both males and females, barrier recovery was delayed with higher doses of sun exposure. In males, sun exposure did not alter SC hydration, while in females SC hydration was lower with lower doses of sun exposure as compared with control and higher doses of sun exposure. These results demonstrated that sun-induced changes in SC function and SC hydration vary with gender and the extent of sun exposure. PMID:20571289

Effect of seasonal and geographical differences on skin and effect of treatment with an osmoprotectant: Sorbitol.

PubMed

Muizzuddin, Neelam; Ingrassia, Michael; Marenus, Kenneth D; Maes, Daniel H; Mammone, Thomas

2013-01-01

Human skin maintains an optimal permeability barrier function in a terrestrial environment that varies considerably in humidity. Cells cultured under hyperosmotic stress accumulate osmolytes including sorbitol. Epidermal keratinocytes experience similar high osmolality under dry environmental conditions because of increased transepidermal water loss (TEWL) and concomitant drying of the skin. This study was designed to determine if epidermal keratinocytes, in vitro, could be protected from high osmotic stress, with the exogenous addition of sorbitol. In addition, we evaluated the effect of a formulation containing topical sorbitol on skin barrier and moisturization of subjects living in arid and humid regions in summer as well as in winter. Results from in vitro experiments showed that 50 mM sorbitol protected epidermal keratinocytes from osmotic toxicity induced by sodium chloride. Clinical studies indicated that skin chronically exposed to hot, dry environment appeared to exhibit stronger skin barrier and a lower baseline TEWL. In addition, skin barrier was stronger in summer than in winter. Sorbitol exhibited significant improvement in both barrier repair and moisturization, especially in individuals subjected to arid environmental conditions.

Oral intake of beet extract provides protection against skin barrier impairment in hairless mice.

PubMed

Kawano, Ken-Ichi; Umemura, Kazuo

2013-05-01

The epidermis acts as a functional barrier against the external environment. Disturbances in the function of this barrier cause water loss and increase the chances of penetration by various irritable stimuli, leading to skin diseases such as dry skin, atopic dermatitis, and psoriasis. Ceramides are a critical natural element of the protective epidermal barrier. The aim of this study was to evaluate whether the oral intake of beet (Beta vulgaris) extract, a natural product rich in glucosylceramide (GlcCer), may prevent disturbance in skin barrier function. When HR-1 hairless mice were fed a special diet (HR-AD), transepidermal water loss (TEWL) from the dorsal skin increased, with a compensatory increase in water intake after 5 weeks. Mice fed with HR-AD had dry skin with erythema and showed increased scratching behaviour. Histological examinations revealed a remarkable increase in the thickness of the skin at 8 weeks. Supplemental addition of beet extract, which contained GlcCer at a final concentration of 0.1%, significantly prevented an increase TEWL, water intake, cumulative scratching time, and epidermal thickness at 8 weeks. These results indicate that oral intake of beet extract shows potential for preventing skin diseases associated with impaired skin barrier function. Copyright © 2012 John Wiley & Sons, Ltd.

Effects of in Utero Exposure of C57BL/6J Mice to 2,3,7,8-Tetrachlorodibenzo-p-dioxin on Epidermal Permeability Barrier Development and Function

PubMed Central

Muenyi, Clarisse S.; Carrion, Sandra Leon; Jones, Lynn A.; Kennedy, Lawrence H.; Slominski, Andrzej T.

2014-01-01

Background: Development of the epidermal permeability barrier (EPB) is essential for neonatal life. Defects in this barrier are found in many skin diseases such as atopic dermatitis. Objective: We investigated the effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) on the development and function of the EPB. Methods: Timed-pregnant C57BL/6J mice were gavaged with corn oil or TCDD (10 μg/kg body weight) on gestation day 12. Embryos were harvested on embryonic day (E) 15, E16, E17, and postnatal day (PND) 1. Results: A skin permeability assay showed that TCDD accelerated the development of the EPB, beginning at E15. This was accompanied by a significant decrease in transepidermal water loss (TEWL), enhanced stratification, and formation of the stratum corneum (SC). The levels of several ceramides were significantly increased at E15 and E16. PND1 histology revealed TCDD-induced acanthosis and epidermal hyperkeratosis. This was accompanied by disrupted epidermal tight junction (TJ) function, with increased dye leakage at the terminal claudin-1–staining TJs of the stratum granulosum. Because the animals did not have enhanced rates of TEWL, a commonly observed phenotype in animals with TJ defects, we performed tape-stripping. Removal of most of the SC resulted in a significant increase in TEWL in TCDD-exposed PND1 pups compared with their control group. Conclusions: These findings demonstrate that in utero exposure to TCDD accelerates the formation of an abnormal EPB with leaky TJs, warranting further study of environmental exposures, epithelial TJ integrity, and atopic disease. Citation: Muenyi CS, Leon Carrion S, Jones LA, Kennedy LH, Slominski AT, Sutter CH, Sutter TR. 2014. Effects of in utero exposure of C57BL/6J mice to 2,3,7,8-tetrachlorodibenzo-p-dioxin on epidermal permeability barrier development and function. Environ Health Perspect 122:1052–1058; http://dx.doi.org/10.1289/ehp.1308045 PMID:24904982

The tyrosine kinase Stitcher activates Grainy head and epidermal wound healing in Drosophila.

PubMed

Wang, Shenqiu; Tsarouhas, Vasilios; Xylourgidis, Nikos; Sabri, Nafiseh; Tiklová, Katarína; Nautiyal, Naumi; Gallio, Marco; Samakovlis, Christos

2009-07-01

Epidermal injury initiates a cascade of inflammation, epithelial remodelling and integument repair at wound sites. The regeneration of the extracellular barrier and damaged tissue repair rely on the precise orchestration of epithelial responses triggered by the injury. Grainy head (Grh) transcription factors induce gene expression to crosslink the extracellular barrier in wounded flies and mice. However, the activation mechanisms and functions of Grh factors in re-epithelialization remain unknown. Here we identify stitcher (stit), a new Grh target in Drosophila melanogaster. stit encodes a Ret-family receptor tyrosine kinase required for efficient epidermal wound healing. Live imaging analysis reveals that Stit promotes actin cable assembly during wound re-epithelialization. Stit activation also induces extracellular signal-regulated kinase (ERK) phosphorylation along with the Grh-dependent expression of stit and barrier repair genes at the wound sites. The transcriptional stimulation of stit on injury triggers a positive feedback loop increasing the magnitude of epithelial responses. Thus, Stit activation upon wounding coordinates cytoskeletal rearrangements and the level of Grh-mediated transcriptional wound responses.

Increased skin barrier disruption by sodium lauryl sulfate in mice expressing a constitutively active STAT6 in T cells.

PubMed

DaSilva, Sonia C; Sahu, Ravi P; Konger, Raymond L; Perkins, Susan M; Kaplan, Mark H; Travers, Jeffrey B

2012-01-01

Atopic dermatitis (AD) is a pruritic, chronic inflammatory skin disease that affects 10-20% of children and 1-3% of adults worldwide. Recent studies have indicated that the ability of Th2 cytokines, such as interleukin-4 (IL-4) to regulate skin barrier function may be a predisposing factor for AD development. The present studies examined the ability of increased Th2 activity to affect cutaneous barrier function in vivo and epidermal thickening. Mice that express a constitutively active Signal Transducer and Activator of Transcription 6 (STAT6VT) have increased Th2 cells and a predisposition to allergic inflammation were used in these studies, they demonstrate that topical treatment with the irritant sodium lauryl sulfate (SLS) caused increased transepidermal water loss and epidermal thickening in STAT6VT mice over similarly treated wild-type mice. The proliferation marker Ki-67 was increased in the epidermis of STAT6VT compared to the wild-type mice. However, these differences do not appear to be linked to the addition of an irritant as control-treated STAT6VT skin also exhibited elevated Ki-67 levels, suggesting that the increased epidermal thickness in SLS-treated STAT6VT mice is primarily driven by epidermal cell hypertrophy rather than an increase in cellular proliferation. Our results suggest that an environment with increased Th2 cytokines results in abnormal responses to topical irritants.

Increased skin barrier disruption by sodium lauryl sulfate in mice expressing a constitutively active STAT6 in T cells

PubMed Central

DaSilva, Sonia C.; Sahu, Ravi P.; Konger, Raymond L.; Perkins, Susan M.; Kaplan, Mark H.; Travers, Jeffrey B.

2011-01-01

Atopic dermatitis (AD) is a pruritic, chronic inflammatory skin disease that affects 10–20% of children and 1–3% of adults worldwide. Recent studies have indicated that the ability of Th2 cytokines such as interleukin-4 (IL-4) to regulate skin barrier function may be a predisposing factor for AD development. The present studies examined the ability of increased Th2 activity to affect cutaneous barrier function in vivo and epidermal thickening. Mice that express a constitutively active Signal Transducer and Activator of Transcription 6 (STAT6VT) have increased Th2 cells and a predisposition to allergic inflammation were used in these studies; they demonstrate that topical treatment with the irritant sodium lauryl sulfate (SLS) caused increased transepidermal water loss and epidermal thickening in STAT6VT mice over similarly treated wild-type mice. The proliferation marker Ki-67 was increased in the epidermis of STAT6VT compared to wild-type mice. However, these differences do not appear to be linked to the addition of an irritant as control-treated STAT6VT skin also exhibited elevated Ki-67 levels, suggesting that the increased epidermal thickness in SLS-treated STAT6VT mice is primarily driven by epidermal cell hypertrophy rather than an increase in cellular proliferation. Our results suggest that an environment with increased Th2 cytokines results in abnormal responses to topical irritants. PMID:21959772

Mast cells are dispensable in a genetic mouse model of chronic dermatitis.

PubMed

Sulcova, Jitka; Meyer, Michael; Guiducci, Eva; Feyerabend, Thorsten B; Rodewald, Hans-Reimer; Werner, Sabine

2015-06-01

Chronic inflammatory skin diseases, such as atopic dermatitis, affect a large percentage of the population, but the role of different immune cells in the pathogenesis of these disorders is largely unknown. Recently, we found that mice lacking fibroblast growth factor receptor 1 (Fgfr1) and Fgfr2 (K5-R1/R2 mice) in the epidermis have a severe impairment in the epidermal barrier, which leads to the development of a chronic inflammatory skin disease that shares many features with human atopic dermatitis. Using Fgfr1-/Fgfr2-deficient mice, we analyzed the consequences of the loss of mast cells. Mast cells accumulated and degranulated in the skin of young Fgfr1-/Fgfr2-deficient mice, most likely as a consequence of increased expression of the mast cell chemokine Ccl2. The increase in mast cells occurred before the development of histological abnormalities, indicating a functional role of these cells in the inflammatory skin phenotype. To test this hypothesis, we mated the Fgfr1-/Fgfr2-deficient mice with mast cell-deficient CreMaster mice. Surprisingly, loss of mast cells did not or only mildly affect keratinocyte proliferation, epidermal thickness, epidermal barrier function, accumulation and activation of different immune cells, or expression of different proinflammatory cytokines in the skin. These results reveal that mast cells are dispensable for the development of chronic inflammation in response to a defect in the epidermal barrier. Copyright © 2015 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.

SNPing at the Epidermal Barrier.

PubMed

Kelsell, David P; Byrne, Carolyn

2011-08-01

Filaggrin variants are well-established risk factors for atopic eczema (AE). Recent studies suggest additional epidermal differentiation complex (EDC) gene associations with AE. In this issue, Marenholz and colleagues confirm this prediction and show that a small proline-rich protein 3 (SPRR3) variant confers susceptibility to AE. This finding suggests that further genetic and functional characterization of SPRR3 should be performed in patients with AE.

Selective Ablation of Ctip2/Bcl11b in Epidermal Keratinocytes Triggers Atopic Dermatitis-Like Skin Inflammatory Responses in Adult Mice

PubMed Central

Guha, Gunjan; Li, Shan; Kyrylkova, Kateryna; Kioussi, Chrissa; Leid, Mark; Ganguli-Indra, Gitali; Indra, Arup K.

2012-01-01

Background Ctip2 is crucial for epidermal homeostasis and protective barrier formation in developing mouse embryos. Selective ablation of Ctip2 in epidermis leads to increased transepidermal water loss (TEWL), impaired epidermal proliferation, terminal differentiation, as well as altered lipid composition during development. However, little is known about the role of Ctip2 in skin homeostasis in adult mice. Methodology/Principal Findings To study the role of Ctip2 in adult skin homeostasis, we utilized Ctip2ep−/− mouse model in which Ctip2 is selectively deleted in epidermal keratinocytes. Measurement of TEWL, followed by histological, immunohistochemical, and RT-qPCR analyses revealed an important role of Ctip2 in barrier maintenance and in regulating adult skin homeostasis. We demonstrated that keratinocytic ablation of Ctip2 leads to atopic dermatitis (AD)-like skin inflammation, characterized by alopecia, pruritus and scaling, as well as extensive infiltration of immune cells including T lymphocytes, mast cells, and eosinophils. We observed increased expression of T-helper 2 (Th2)-type cytokines and chemokines in the mutant skin, as well as systemic immune responses that share similarity with human AD patients. Furthermore, we discovered that thymic stromal lymphopoietin (TSLP) expression was significantly upregulated in the mutant epidermis as early as postnatal day 1 and ChIP assay revealed that TSLP is likely a direct transcriptional target of Ctip2 in epidermal keratinocytes. Conclusions/Significance Our data demonstrated a cell-autonomous role of Ctip2 in barrier maintenance and epidermal homeostasis in adult mice skin. We discovered a crucial non-cell autonomous role of keratinocytic Ctip2 in suppressing skin inflammatory responses by regulating the expression of Th2-type cytokines. It is likely that the epidermal hyperproliferation in the Ctip2-lacking epidermis may be secondary to the compensatory response of the adult epidermis that is defective in barrier functions. Our results establish an initiating role of epidermal TSLP in AD pathogenesis via a novel repressive regulatory mechanism enforced by Ctip2. PMID:23284675

Burn Injury Alters Epidermal Cholinergic Mediators and Increases HMGB1 and Caspase 3 in Autologous Donor Skin and Burn Margin

PubMed Central

Holmes, Casey J.; Plichta, Jennifer K.; Gamelli, Richard L.; Radek, Katherine A.

2016-01-01

Burn wound healing complications, such as graft failure or infection, are a major source of morbidity and mortality in burn patients. The mechanisms by which local burn injury alters epidermal barrier function in autologous donor skin and surrounding burn margin are largely undefined. We hypothesized that defects in the epidermal cholinergic system may impair epidermal barrier function and innate immune responses. The objective was to identify alterations in the epidermal cholinergic pathway, and their downstream targets, associated with inflammation and cell death. We established that protein levels, but not gene expression, of the α7 nicotinic acetylcholine receptor (CHRNA7) were significantly reduced in both donor and burn margin skin. Furthermore, the gene and protein levels of an endogenous allosteric modulator of CHRNA7, secreted mammalian Ly-6/urokinase-type plasminogen activator receptor-related protein-1 (SLURP1) and acetylcholine were significantly elevated in donor and burn margin skin. As downstream proteins of inflammatory and cell death targets of nAChR activation, we found significant elevations in epidermal High Mobility Group Box Protein 1 (HMGB1) and caspase 3 in donor and burn margin skin. Lastly, we employed a novel in vitro keratinocyte burn model to establish that burn injury influences the gene expression of these cholinergic mediators and their downstream targets. These results indicate that defects in cholinergic mediators and inflammatory/apoptotic molecules in donor and burn margin skin may directly contribute to graft failure or infection in burn patients. PMID:27648692

Regulation of 3-hydroxy-3-methylglutaryl-coenzyme A reductase activity in murine epidermis. Modulation of enzyme content and activation state by barrier requirements.

PubMed Central

Proksch, E; Elias, P M; Feingold, K R

1990-01-01

Epidermal cholesterol biosynthesis is regulated by barrier function. We quantitated the amount and activation state (phosphorylation-dephosphorylation) of the rate-limiting enzyme, 3-hydroxy-3-methylglutaryl coenzyme A (HMG CoA) reductase, in epidermis before and after barrier disruption. In murine epidermis we found high enzyme activity (1.75 +/- 0.02 nmol/min per mg protein). After acute barrier disruption, enzyme activity began to increase after 1.5 h, reaching a maximum increase by 2.5 h, and returned to normal by 15 h. Chronic barrier disruption increased total enzyme activity by 83%. In normal epidermis, measurement of HMG CoA reductase activity in microsomes isolated in NaF- vs. NaCl-containing buffers demonstrated that 46 +/- 2% of the enzyme was in the active form. After acute or chronic barrier disruption, a marked increase in the percentage of HMG CoA reductase in the active form was observed. Acute disruption increased enzyme activation state as early as 15 min, reaching a maximum after 2.5 h, with an increase still present at 15 h, indicating that changes in activation state had a close temporal relationship with barrier function. Increases in total HMG CoA reductase activity occurred only after profound barrier disruption, whereas changes in activation state occur with lesser degrees of barrier disruption. Artificial correction of barrier function prevented the increase in total HMG CoA reductase activity, and partially prevented the increase in enzyme activation. These results show that barrier requirements regulate epidermal cholesterol synthesis by modulating both the HMG CoA reductase amount and activation state. Images PMID:2312730

The influence of body mass index on skin susceptibility to sodium lauryl sulphate.

PubMed

Löffler, H; Aramaki, J U N; Effendy, Isaak

2002-02-01

The influence of nutrition on the physiological functions of man is well studied. Numerous diseases can be exacerbated by obesity. However, it has not yet been determined whether body weight and body mass index (BMI), as an indicator of a high body fat store, can influence skin sensitivity. This study investigates the correlation between body mass index and the epidermal functions, evaluated by bioengineering methods, before and after an irritant patch test with sodium lauryl sulphate (SLS). Epidermal functions were evaluated using an evaporimeter, chromameter and laser-Doppler-flowmeter. Patch testing was conducted for 48 h with two different concentrations of SLS (0.25% and 0.5%) on the forearms of healthy volunteers. Measurements were performed 24h after patch removal. Obese individuals showed significantly increased transepidermal water loss (TEWL), skin blood flow and skin colour (red) as compared to a control group. However, the degree of skin sensitivity to SLS was not correlated with BMI. Basal biophysical parameters of the skin are primarily correlated with the BMI. This may be caused by obesity-induced physiological changes, e.g. increased sweat gland activity, high blood pressure and physiological temperature-regulating system. The epidermal barrier function, as evaluated after SLS patch testing is, however, not correlated with a high BMI, indicating a normal skin barrier.

Standards for the Protection of Skin Barrier Function.

PubMed

Giménez-Arnau, Ana

2016-01-01

The skin is a vital organ, and through our skin we are in close contact with the entire environment. If we lose our skin we lose our life. The barrier function of the skin is mainly driven by the sophisticated epidermis in close relationship with the dermis. The epidermal epithelium is a mechanically, chemically, biologically and immunologically active barrier submitted to continuous turnover. The barrier function of the skin needs to be protected and restored. Its own physiology allows its recovery, but many times this is not sufficient. This chapter is focused on the standards to restore, treat and prevent barrier function disruption. These standards were developed from a scientific, academic and clinical point of view. There is a lack of standardized administrative recommendations. Still, there is a walk to do that will help to reduce the social and economic burden of diseases characterized by an abnormal skin barrier function. © 2016 S. Karger AG, Basel.

Epidermal ADAM17 maintains the skin barrier by regulating EGFR ligand–dependent terminal keratinocyte differentiation

PubMed Central

Cobzaru, Cristina; Triantafyllopoulou, Antigoni; Löffek, Stefanie; Horiuchi, Keisuke; Threadgill, David W.; Kurz, Thomas; van Rooijen, Nico; Bruckner-Tuderman, Leena

2012-01-01

ADAM17 (a disintegrin and metalloproteinase 17) is ubiquitously expressed and cleaves membrane proteins, such as epidermal growth factor receptor (EGFR) ligands, l-selectin, and TNF, from the cell surface, thus regulating responses to tissue injury and inflammation. However, little is currently known about its role in skin homeostasis. We show that mice lacking ADAM17 in keratinocytes (A17ΔKC) have a normal epidermal barrier and skin architecture at birth but develop pronounced defects in epidermal barrier integrity soon after birth and develop chronic dermatitis as adults. The dysregulated expression of epidermal differentiation proteins becomes evident 2 d after birth, followed by reduced transglutaminase (TGM) activity, transepidermal water loss, up-regulation of the proinflammatory cytokine IL-36α, and inflammatory immune cell infiltration. Activation of the EGFR was strongly reduced in A17ΔKC skin, and topical treatment of A17ΔKC mice with recombinant TGF-α significantly improved TGM activity and decreased skin inflammation. Finally, we show that mice lacking the EGFR in keratinocytes (EgfrΔKC) closely resembled A17ΔKC mice. Collectively, these results identify a previously unappreciated critical role of the ADAM17–EGFR signaling axis in maintaining the homeostasis of the postnatal epidermal barrier and suggest that this pathway could represent a good target for treatment of epidermal barrier defects. PMID:22565824

Epidermal Overexpression of Xenobiotic Receptor PXR Impairs the Epidermal Barrier and Triggers Th2 Immune Response.

PubMed

Elentner, Andreas; Schmuth, Matthias; Yannoutsos, Nikolaos; Eichmann, Thomas O; Gruber, Robert; Radner, Franz P W; Hermann, Martin; Del Frari, Barbara; Dubrac, Sandrine

2018-01-01

The skin is in daily contact with environmental pollutants, but the long-term effects of such exposure remain underinvestigated. Many of these toxins bind and activate the pregnane X receptor (PXR), a ligand-activated transcription factor that regulates genes central to xenobiotic metabolism. The objective of this work was to investigate the effect of constitutive activation of PXR in the basal layer of the skin to mimic repeated skin exposure to noxious molecules. We designed a transgenic mouse model that overexpresses the human PXR gene linked to the herpes simplex VP16 domain under the control of the keratin 14 promoter. We show that transgenic mice display increased transepidermal water loss and elevated skin pH, abnormal stratum corneum lipids, focal epidermal hyperplasia, activated keratinocytes expressing more thymic stromal lymphopoietin, a T helper type 2/T helper type 17 skin immune response, and increased serum IgE. Furthermore, the cutaneous barrier dysfunction precedes development of the T helper type 2/T helper type 17 inflammation in transgenic mice, thereby mirroring the time course of atopic dermatitis development in humans. Moreover, further experiments suggest increased PXR signaling in the skin of patients with atopic dermatitis when compared with healthy skin. Thus, PXR activation by environmental pollutants may compromise epidermal barrier function and favor an immune response resembling atopic dermatitis. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Staphylococcus aureus keratinocyte invasion is mediated by integrin-linked kinase and Rac1.

PubMed

Sayedyahossein, Samar; Xu, Stacey X; Rudkouskaya, Alena; McGavin, Martin J; McCormick, John K; Dagnino, Lina

2015-02-01

Staphylococcus aureus is a major component of the skin microbiota and causes a large number of serious infections. S. aureus first interacts with epidermal keratinocytes to breach the epidermal barrier through mechanisms not fully understood. By use of primary keratinocytes from mice with epidermis-restricted Ilk gene inactivation and control integrin-linked kinase (ILK)-expressing littermates, we investigated the role of ILK in epidermal S. aureus invasion. Heat-killed, but not live, bacteria were internalized to Rab5- and Rab7-positive phagosomes, and incubation with keratinocyte growth factor increased their uptake 2.5-fold. ILK-deficient mouse keratinocytes internalized bacteria 2- to 4-fold less efficiently than normal cells. The reduced invasion by live S. aureus of ILK-deficient cells was restored in the presence of exogenous, constitutively active Rac1. Thus, Rac1 functions downstream from ILK during invasion. Further, invasion by S. aureus of Rac1-deficient cells was 2.5-fold lower than in normal cells. Paradoxically, staphylococcal cutaneous penetration of mouse skin explants with ILK-deficient epidermis was 35-fold higher than that of normal skin, indicating defects in epidermal barrier function in the absence of ILK. Thus, we identified an ILK-Rac1 pathway essential for bacterial invasion of keratinocytes, and established ILK as a key contributor to prevent invasive staphylococcal cutaneous infection. © FASEB.

[The stratum corneum].

PubMed

Haftek, M

2002-01-01

Epidermal differentiation is a continuous process, constituting and renewing a protective layer at the skin surface: the stratum corneum, composed of cornified keratinocytes that is a barrier to water diffusion. Massive loss of physiologic liquids is one of the severest consequences of extensive burns. The stratum corneum also protects the subjacent tissues from xenobiotic aggression, ultraviolet radiation (70 p. cent of UVB absorption) and from mechanic aggression. The integrity of the stratum corneum depends on three elements: 1) the physico-chemical quality of the cornified cells, 2) the persistence of mechanical junctions uniting these cells and 3) the organization and composition of the lipid "mortar" in the intercellular spaces. Since all these components are issued from the keratinocyte differentiation process, any perturbation may, in time, induce modifications in the "barrier" function of the epidermis. The barrier quality varies, depending on its localization (soles of the feet, palms of the hands and transitional epidermis of the lips), during skin healing (priority to keratinocyte proliferation to the detriment of maturation) under the influence of treatment (retinoids, vitamin D derivatives), in the course of aging and diseases: ichtyosis and other keratinization genodermatoses, benign (including psoriasis) and malignant hyperproliferative diseases. Furthermore, the relative impermeability of the stratum corneum is an important factor limiting the penetration and diffusion of allergens, but also local drugs delivered with local and systemic trans-epidermal treatments. Further knowledge is required on the function of the epidermal barrier and the mechanism regulating cohesion/desquamation of the stratum corneum to understand certain hereditary diseases, improve efficacy of topical therapeutic products and optimize cosmetic formulations.

Acute irritant threshold correlates with barrier function, skin hydration and contact hypersensitivity in atopic dermatitis and rosacea.

PubMed

Darlenski, Razvigor; Kazandjieva, Jana; Tsankov, Nikolai; Fluhr, Joachim W

2013-11-01

The aim of the study was to disclose interactions between epidermal barrier, skin irritation and sensitization in healthy and diseased skin. Transepidermal water loss (TEWL) and stratum corneum hydration (SCH) were assessed in adult patients with atopic dermatitis (AD), rosacea and healthy controls. A 4-h patch test with seven concentrations of sodium lauryl sulphate was performed to determine the irritant threshold (IT). Contact sensitization pattern was revealed by patch testing with European baseline series. Subjects with a lower IT had higher TEWL values and lower SCH. Subjects with positive allergic reactions had significantly lower IT. In AD, epidermal barrier deterioration was detected on both volar forearm and nasolabial fold, while in rosacea, impeded skin physiology parameters were observed on the facial skin only, suggesting that barrier impediment is restricted to the face in rosacea, in contrast with AD where the abnormal skin physiology is generalized. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

The unique and cooperative roles of the Grainy head-like transcription factors in epidermal development reflect unexpected target gene specificity.

PubMed

Boglev, Yeliz; Wilanowski, Tomasz; Caddy, Jacinta; Parekh, Vishwas; Auden, Alana; Darido, Charbel; Hislop, Nikki R; Cangkrama, Michael; Ting, Stephen B; Jane, Stephen M

2011-01-15

The Grainy head-like 3 (Grhl3) gene encodes a transcription factor that plays essential roles in epidermal morphogenesis during embryonic development, with deficient mice exhibiting failed skin barrier formation, defective wound repair, and loss of eyelid fusion. Despite sharing significant sequence homology, overlapping expression patterns, and an identical core consensus DNA binding site, the other members of the Grhl family (Grhl1 and -2) fail to compensate for the loss of Grhl3 in these processes. Here, we have employed diverse genetic models, coupled with biochemical studies, to define the inter-relationships of the Grhl factors in epidermal development. We show that Grhl1 and Grhl3 have evolved complete functional independence, as evidenced by a lack of genetic interactions in embryos carrying combinations of targeted alleles of these genes. In contrast, compound heterozygous Grhl2/Grhl3 embryos displayed failed wound repair, and loss of a single Grhl2 allele in Grhl3-null embryos results in fully penetrant eyes open at birth. Expression of Grhl2 from the Grhl3 locus in homozygous knock-in mice corrects the wound repair defect, but these embryos still display a complete failure of skin barrier formation. This functional dissociation is due to unexpected differences in target gene specificity, as both GRHL2 and GRHL3 bind to and regulate expression of the wound repair gene Rho GEF 19, but regulation of the barrier forming gene, Transglutaminase 1 (TGase1), is unique to GRHL3. Our findings define the mechanisms underpinning the unique and cooperative roles of the Grhl genes in epidermal development. Copyright © 2010 Elsevier Inc. All rights reserved.

Therapeutic approach to mite-induced intractable dermatitis using novel immunomodulator FTY720 ointment (fingolimod) in NC/Nga mice.

PubMed

Tsuji, Takumi; Okuno, Satoshi; Kuroda, Ayano; Hamazaki, Junya; Chikami, Takuma; Sakurai, Sakura; Yoshida, Yuya; Banno, Rie; Fujita, Tetsuro; Kohno, Takeyuki

2016-04-01

The increasing incidence and prevalence of atopic dermatitis (AD) demands new therapeutic approaches for treating the disease. We investigated the therapeutic efficacy of immunomodulator FTY720 ointment (fingolimod) for mite-induced intractable AD using an NC/Nga mouse model. Female NC/Nga mice that developed severe AD were divided into four groups: (1) FTY720 (0.001% FTY720 ointment), (2) tacrolimus (tacrolimus hydrate ointment) (3) betamethasone (betamethasone ointment), and (4) ointment base (hydrophilic petrolatum), all of which received treatment six times per week. Therapeutic efficacy after two weeks was evaluated in terms of AD severity, histochemical observations (epidermal hypertrophy, mast cell accumulation, and CD3(+) T cell infiltration), transepidermal water loss (TEWL), and epidermal barrier function (filaggrin expression). Betamethasone treatment showed little effect, confirming that the AD was intractable. In the FTY720 group, AD improved significantly compared with the ointment base group, as did epidermal hypertrophy, mast cell accumulation, and CD3(+) T cell infiltration. In contrast, AD in the tacrolimus and betamethasone groups did not improve significantly, nor did epidermal hypertrophy or mast cell accumulation. Furthermore, in the FTY720 group, TEWL decreased significantly compared with the ointment base group, and filaggrin expression significantly increased compared with the betamethasone and ointment base groups. FTY720 ointment is a promising candidate for treatment of intractable AD. These findings also provide the first evidence that FTY720 ointment ameliorates epidermal barrier function. Copyright © 2015 Japanese Society of Allergology. Production and hosting by Elsevier B.V. All rights reserved.

Learning from eponyms: George F. Odland and Odland bodies

PubMed Central

Joshi, Rajiv

2014-01-01

Odland bodies (lamellar) bodies are small sub-cellular structures of size 200-300 nm that are present in the upper spinous and granular cell layers of the epidermis. These act as processing and repository areas for lipids that contribute to the epidermal permeability barrier. They also contain proteases, cathepsin D, kallikrein and other proteins including corneo-desmosins. Recent information also credits them with a role in the local innate immune response as they contain beta 2 defensins, which are anti-microbial peptides with potent activity against Gram-negative bacteria and candida. Odland bodies are important for maintaining homeostasis of the epidermis and are involved in epidermal permeability barrier function, desquamation of keratinocytes, formation of the cornified envelope and in local anti-microbial immunity. This article reviews the structure and functions of these bodies with a brief biography of George F. Odland who first described these bodies in 1960 and whose name is eponymically associated with them. PMID:25165659

The barrier function of organotypic non-melanoma skin cancer models.

PubMed

Zoschke, Christian; Ulrich, Martina; Sochorová, Michaela; Wolff, Christopher; Vávrová, Kateřina; Ma, Nan; Ulrich, Claas; Brandner, Johanna M; Schäfer-Korting, Monika

2016-07-10

Non-melanoma skin cancer (NMSC) is the most frequent human cancer with continuously rising incidences worldwide. Herein, we investigated the molecular basis for the impaired skin barrier function of organotypic NMSC models. We unraveled disturbed epidermal differentiation by reflectance confocal microscopy and histopathological evaluation. While the presence of claudin-4 and occludin were distinctly reduced, zonula occludens protein-1 was more wide-spread, and claudin-1 was heterogeneously distributed within the NMSC models compared with normal reconstructed human skin. Moreover, the cancer altered stratum corneum lipid packing and profile with decreased cholesterol content, increased phospholipid amount, and altered ceramide subclasses. These alterations contributed to increased surface pH and to 1.5 to 2.6-fold enhanced caffeine permeability of the NMSC models. Three topical applications of ingenol mebutate gel (0.015%) caused abundant epidermal cell necrosis, decreased Ki-67 indices, and increased lactate dehydrogenase activity. Taken together, our study provides new biological insights into the microenvironment of organotypic NMSC models, improves the understanding of the disease model by revealing causes for impaired skin barrier function in NMSC models at the molecular level, and fosters human cell-based approaches in preclinical drug evaluation. Copyright © 2016 Elsevier B.V. All rights reserved.

The Membrane-anchored Serine Protease Prostasin (CAP1/PRSS8) Supports Epidermal Development and Postnatal Homeostasis Independent of Its Enzymatic Activity*

PubMed Central

Peters, Diane E.; Szabo, Roman; Friis, Stine; Shylo, Natalia A.; Uzzun Sales, Katiuchia; Holmbeck, Kenn; Bugge, Thomas H.

2014-01-01

The membrane-anchored serine protease prostasin (CAP1/PRSS8) is part of a cell surface proteolytic cascade that is essential for epithelial barrier formation and homeostasis. Here, we report the surprising finding that prostasin executes these functions independent of its own enzymatic activity. Prostasin null (Prss8−/−) mice lack barrier formation and display fatal postnatal dehydration. In sharp contrast, mice homozygous for a point mutation in the Prss8 gene, which causes the substitution of the active site serine within the catalytic histidine-aspartate-serine triad with alanine and renders prostasin catalytically inactive (Prss8Cat−/Cat− mice), develop barrier function and are healthy when followed for up to 20 weeks. This striking difference could not be explained by genetic modifiers or by maternal effects, as these divergent phenotypes were displayed by Prss8−/− and Prss8Cat−/Cat− mice born within the same litter. Furthermore, Prss8Cat−/Cat− mice were able to regenerate epidermal covering following cutaneous wounding. This study provides the first demonstration that essential in vivo functions of prostasin are executed by a non-enzymatic activity of this unique membrane-anchored serine protease. PMID:24706745

Cellular, ultrastructural and molecular analyses of epidermal cell development in the planarian Schmidtea mediterranea.

PubMed

Cheng, Li-Chun; Tu, Kimberly C; Seidel, Chris W; Robb, Sofia M C; Guo, Fengli; Sánchez Alvarado, Alejandro

2018-01-15

The epidermis is essential for animal survival, providing both a protective barrier and cellular sensor to external environments. The generally conserved embryonic origin of the epidermis, but the broad morphological and functional diversity of this organ across animals is puzzling. We define the transcriptional regulators underlying epidermal lineage differentiation in the planarian Schmidtea mediterranea, an invertebrate organism that, unlike fruitflies and nematodes, continuously replaces its epidermal cells. We find that Smed-p53, Sox and Pax transcription factors are essential regulators of epidermal homeostasis, and act cooperatively to regulate genes associated with early epidermal precursor cell differentiation, including a tandemly arrayed novel gene family (prog) of secreted proteins. Additionally, we report on the discovery of distinct and previously undescribed secreted organelles whose production is dependent on the transcriptional activity of soxP-3, and which we term Hyman vesicles. Copyright © 2017 Elsevier Inc. All rights reserved.

Grhl3 and Lmo4 play coordinate roles in epidermal migration.

PubMed

Hislop, Nikki R; Caddy, Jacinta; Ting, Stephen B; Auden, Alana; Vasudevan, Sumitha; King, Sarah L; Lindeman, Geoffrey J; Visvader, Jane E; Cunningham, John M; Jane, Stephen M

2008-09-01

In addition to its role in formation of the epidermal barrier, the mammalian transcription factor Grainy head-like 3 (Grhl3) is also essential for neural tube closure and wound repair, processes that are dependent in part on epidermal migration. Here, we demonstrate that the LIM-only domain protein, LMO4 serves as a functional partner of GRHL3 in its established roles, and define a new cooperative role for these factors in another developmental epidermal migration event, eyelid fusion. GRHL3 and LMO4 interact biochemically and genetically, with mutant mice exhibiting fully penetrant exencephaly, thoraco-lumbo-sacral spina bifida, defective skin barrier formation, and a co-incident eyes-open-at-birth (EOB) phenotype, which is not observed in the original individual null lines. The two genes are co-expressed in the surface ectoderm of the migrating eyelid root, and electron microscopy of Grhl3/Lmo4-null eyes reveals a failure in epithelial extension and a lack of peridermal clump formation at the eyelid margins. Accumulation of actin fibers is also absent in the circumference of these eyelids, and ERK1/2 phosphorylation is lost in the epidermis and eyelids of Grhl3(-/-)/Lmo4(-/-) embryos. Keratinocytes from mutant mice fail to "heal" in in vitro scratch assays, consistent with a general epidermal migratory defect that is dependent on ERK activation and actin cable formation.

Effects of topical application of aqueous solutions of hexoses on epidermal permeability barrier recovery rate after barrier disruption.

PubMed

Denda, Mitsuhiro

2011-11-01

Previous studies have suggested that hexose molecules influence the stability of phospholipid bilayers. Therefore, the effects of topical application of all 12 stereoisomers of dextro-hexose on the epidermal barrier recovery rate after barrier disruption were evaluated. Immediately after tape stripping, 0.1 m aqueous solution of each hexose was applied on hairless mouse skin. Among the eight dextro-aldohexoses, topical application of altose, idose, mannose and talose accelerated the barrier recovery, while allose, galactose, glucose and gulose had no effect. Among the four dextro-ketohexoses, psicose, fructose, sorbose and tagatose all accelerated the barrier recovery. As the effects of hexoses on the barrier recovery rate appeared within 1 h, the mechanism is unlikely to be genomic. Instead, these hexoses may influence phase transition of the lipid bilayers of lamellar bodies and cell membrane, a crucial step in epidermal permeability barrier homeostasis. © 2011 John Wiley & Sons A/S.

Mast Cells Regulate Epidermal Barrier Function and the Development of Allergic Skin Inflammation.

PubMed

Sehra, Sarita; Serezani, Ana P M; Ocaña, Jesus A; Travers, Jeffrey B; Kaplan, Mark H

2016-07-01

Atopic dermatitis is a chronic inflammatory skin disease characterized by infiltration of eosinophils, T helper cells, and mast cells. The role of mast cells in atopic dermatitis is not completely understood. To define the effects of mast cells on skin biology, we observed that mast cells regulate the homeostatic expression of epidermal differentiation complex and other skin genes. Decreased epidermal differentiation complex gene expression in mice that genetically lack mast cells (Kit(W-sh/W-sh) mice) is associated with increased uptake of protein antigens painted on the skin by dendritic cells (DCs) compared with similarly treated wild-type mice, suggesting a protective role for mast cells in exposure to nominal environmental allergens. To test this further, we crossed Kit(W-sh/W-sh) mice with signal transducer and activator of transcription 6 (i.e., Stat6) VT transgenic mice that develop spontaneous atopic dermatitis-like disease that is dependent on T helper cell 2 cytokines and is associated with high serum concentrations of IgE. We observed that Stat6VT × Kit(W-sh/W-sh) mice developed more frequent and more severe allergic skin inflammation than Stat6VT transgenic mice that had mast cells. Together, these studies suggest that mast cells regulate epidermal barrier function and have a potential protective role in the development of atopic dermatitis-like disease. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Role of Ca++ Influx via Epidermal TRP Ion Channels

DTIC Science & Technology

2014-10-01

determine the epidermis’ response to activation of TRP channels. 2 Keywords Amputation stump, irritant dermatitis , epidermis, skin barrier function, TRP...the personnel who is in contact with subjects. All these requirements were addressed satisfactorily. Impact We view the pilot finding that

Comparison of the Efficacy of Atopalm(®) Multi-Lamellar Emulsion Cream and Physiogel(®) Intensive Cream in Improving Epidermal Permeability Barrier in Sensitive Skin.

PubMed

Jeong, Sekyoo; Lee, Sin Hee; Park, Byeong Deog; Wu, Yan; Man, George; Man, Mao-Qiang

2016-03-01

The management of sensitive skin, which affects over 60% of the general population, has been a long-standing challenge for both patients and clinicians. Because defective epidermal permeability barrier is one of the clinical features of sensitive skin, barrier-enhancing products could be an optimal regimen for sensitive skin. In the present study, we evaluated the efficacy and safety of two barrier-enhancing products, i.e., Atopalm (®) Multi-Lamellar Emulsion (MLE) Cream and Physiogel (®) Intensive Cream for sensitive skin. 60 patients with sensitive skin, aged 22-40 years old, were randomly assigned to one group treated with Atopalm MLE Cream, and another group treated with Physiogel Intensive Cream twice daily for 4 weeks. Lactic acid stinging test scores (LASTS), stratum hydration (SC) and transepidermal water loss (TEWL) were assessed before, 2 and 4 weeks after the treatment. Atopalm MLE Cream significantly lowered TEWL after 2 and 4 weeks of treatment (p < 0.01). In contrast, Physiogel Intensive Cream significantly increased TEWL after 2 weeks of treatment (p < 0.05) while TEWL significantly decreased after 4-week treatments. Moreover, both Atopalm MLE Cream and Physiogel Intensive Cream significantly increased SC hydration, and improved LASTS after 4 weeks of treatment. Both barrier-enhancing products are effective and safe for improving epidermal functions, including permeability barrier, SC hydration and LASTS, in sensitive skin. These products could be a valuable alternative for management of sensitive skin. Veterans Affairs Medical Center, San Francisco, California, USA, and NeoPharm Co., Ltd., Daejeon, Korea.

Differential partitioning of triterpenes and triterpene esters in apple peel

USDA-ARS?s Scientific Manuscript database

Apple peel functions as a protective barrier against biotic and abiotic stresses, and preserving the integrity and appearance of peel critical for market acceptance. Peel epidermal cells and epicuticular wax are a rich source of secondary metabolites, including triterpenes. Several studies have ou...

Heavy Cigarette Smokers in a Chinese Population Display a Compromised Permeability Barrier

PubMed Central

Xin, Shujun; Ye, Li; Lv, Chengzhi; Elias, Peter M.

2016-01-01

Cigarette smoking is associated with various cutaneous disorders with defective permeability. Yet, whether cigarette smoking influences epidermal permeability barrier function is largely unknown. Here, we measured skin biophysical properties, including permeability barrier homeostasis, stratum corneum (SC) integrity, SC hydration, skin surface pH, and skin melanin/erythema index, in cigarette smokers. A total of 99 male volunteers were enrolled in this study. Smokers were categorized as light-to-moderate (<20 cigarettes/day) or heavy smokers (≥20 cigarettes/day). An MPA5 was used to measure SC hydration and skin melanin/erythema index on the dorsal hand, forehead, and cheek. Basal transepidermal water loss (TEWL) and barrier recovery rates were assessed on the forearm. A Skin-pH-Meter pH900 was used to measure skin surface pH. Our results showed that heavy cigarette smokers exhibited delayed barrier recovery after acute abrogation (1.02% ± 13.06 versus 16.48% ± 6.07), and barrier recovery rates correlated negatively with the number of daily cigarettes consumption (p = 0.0087). Changes in biophysical parameters in cigarette smokers varied with body sites. In conclusion, heavy cigarette smokers display compromised permeability barrier homeostasis, which could contribute, in part, to the increased prevalence of certain cutaneous disorders characterized by defective permeability. Thus, improving epidermal permeability barrier should be considered for heavy cigarette smokers. PMID:27437403

Fatty Aldehyde and Fatty Alcohol Metabolism: Review and Importance for Epidermal Structure and Function

PubMed Central

Rizzo, William B.

2014-01-01

Normal fatty aldehyde and alcohol metabolism is essential for epidermal differentiation and function. Long-chain aldehydes are produced by catabolism of several lipids including fatty alcohols, sphingolipids, ether glycerolipids, isoprenoid alcohols and certain aliphatic lipids that undergo α- or ω-oxidation. The fatty aldehyde generated by these pathways is chiefly metabolized to fatty acid by fatty aldehyde dehydrogenase (FALDH, alternately known as ALDH3A2), which also functions to oxidize fatty alcohols as a component of the fatty alcohol:NAD oxidoreductase (FAO) enzyme complex. Genetic deficiency of FALDH/FAO in patients with Sjögren-Larsson syndrome (SLS) results in accumulation of fatty aldehydes, fatty alcohols and related lipids (ether glycerolipids, wax esters) in cultured keratinocytes. These biochemical changes are associated with abnormalities in formation of lamellar bodies in the stratum granulosum and impaired delivery of their precursor membranes to the stratum corneum (SC). The defective extracellular SC membranes are responsible for a leaky epidermal water barrier and ichthyosis. Although lamellar bodies appear to be the pathogenic target for abnormal fatty aldehyde/alcohol metabolism in SLS, the precise biochemical mechanisms are yet to be elucidated. Nevertheless, studies in SLS highlight the critical importance of FALDH and normal fatty aldehyde/alcohol metabolism for epidermal function. PMID:24036493

[Impact of wet work on epidermal barrier (tewl and stratum corneum hydration) and skin viscoelasticity in nurses].

PubMed

Kieć-Świcrczyńska, Marta; Chomiczewska-Skóra, Dorota; Świerczyńska-Machura, Dominika; Kręcisz, Beata

2014-01-01

Nurses are prone to develop hand eczema due to occupational exposure to irritants, including wet work. The aim of the study was to evaluate the impact of wet work on selected skin properties, reflecting epidermal barrier function--transepidermal water loss (TEWL) and stratum corneum hydration--and additionally skin viscoelasticity, in nurses. Study subjects included 90 nurses employed in hospital wards. Measurements were carried out within the dorsal aspect of the dominant hand, using a Cutometer MPA 580 equipped with Tewameter TM 300 and Corneometer CM 825 (Courage & Khazaka, Germany) probes. Examina- tions took place on hospital premises. Similar measurements were performed in the control group of females non-exposed to irritants. In the examined group of nurses, mean TEWL was 15.5 g/h/m2 and was higher than in the control group (12.99 g/h/m2). After rejecting the extreme results, the difference between the groups proved to be statistically significant (p < 0.05). The mean value of stratum corneum hydration was lower in the examined group (37.915) compared with the control group (40.05), but the difference was not sta tistically significant. Also results of viscoelasticity assessment showed no significant differences between studied groups. The results of the assessment of skin biophysical properties show that wet work exerts a moderately adverse impact on skin condition. A higher TEWL value and a lower stratum corneum hydration in workers exposed to irritants reflect an adverse impact of these factors on the epidermal barrier function.

The Role of Moisturizers in Addressing Various Kinds of Dermatitis: A Review

PubMed Central

Indrastuti, Niken; Danarti, Retno; Saefudin, Tatan

2017-01-01

Moisturizer is a major component of basic daily skin care, particularly in presence of epidermal barrier alteration and reduced epidermal water content. It is an important part of a dermatologist’s strategy to maintain skin health as well as treating various dermatoses which co-exist with skin dryness and are linked to impaired skin barrier function, such as in atopic disorders as well as other types of dermatitis. Mastering the knowledge regarding mechanism of action, application, dosage, adverse effects as well as specific clinical usage of moisturizers is a must for a dermatologist in order to support their use, particularly for evidence-based, therapeutic purposes. This review discusses the use of moisturizer both for skin health maintenance as well as a definitive or adjuvant therapy for many kinds of dermatitis. PMID:29229630

Metabolic approaches to enhance transdermal drug delivery. 1. Effect of lipid synthesis inhibitors.

PubMed

Tsai, J C; Guy, R H; Thornfeldt, C R; Gao, W N; Feingold, K R; Elias, P M

1996-06-01

The intercellular domains of the stratum corneum, which contain a mixture of cholesterol, free fatty acids, and ceramides, mediate both the epidermal permeability barrier and the transdermal delivery of both lipophilic and hydrophilic molecules. Prior studies have shown that each of the three key lipid classes is required for normal barrier function. For example, selective inhibition of either cholesterol, fatty acid, or ceramide synthesis in the epidermis delays barrier recovery rates after barrier perturbation of hairless mouse skin in vivo. In this study, we investigated the potential of certain inhibitors of lipid synthesis to enhance the transdermal delivery of lidocaine or caffeine as a result of their capacity to perturb barrier homeostasis. After acetone disruption of the barrier, the extent of lidocaine delivery and the degree of altered barrier function paralleled each other. Moreover, the further alteration in barrier function produced by either the fatty acid synthesis inhibitor 5-(tetradecyloxy)-2-furancarboxylic acid (TOFA), the cholesterol synthesis inhibitor fluvastatin (FLU), or cholesterol sulfate (CS) resulted in a further increase in lidocaine absorption. Furthermore, coapplications of TOFA and CS together caused an additive increase in lidocaine uptake. Finally, a comparable increase in drug delivery occurred when the barrier was disrupted initially with DMSO instead of acetone; coapplications of TOFA and FLU together again delayed barrier recovery and increased drug delivery by about 8-fold vs delivery from a standard enhancing vehicle. Whereas these metabolic inhibitors also variably increased the octanol/water partitioning of the drugs studied (perhaps via complexion or pH alterations), physicochemical effects of the inhibitors alone did not alter drug uptake in intact skin; i.e., passive mechanisms alone cannot account for the net increase in drug delivery. Our results show that modulations of epidermal lipid biosynthesis, following application of conventional, chemical penetration enhancers, cause a further boost in drug delivery, attributable to the ability of these agents to alter both permeability barrier homeostasis and thermodynamics. This biochemical/metabolic approach provides a novel means to enhance transdermal drug delivery in conjunction with the concurrent or prior use of chemical enhancers.

Reevaluation of the non-lesional dry skin in atopic dermatitis by acute barrier disruption: an abnormal permeability barrier homeostasis with defective processing to generate ceramide.

PubMed

Sugiura, Ayumi; Nomura, Tsuyoshi; Mizuno, Atsuko; Imokawa, Genji

2014-07-01

Atopic dermatitis is characterized by disruption of the cutaneous barrier due to reduced ceramide levels even in non-lesional dry skin. Following further acute barrier disruption by repeated tape strippings, we re-characterized the non-lesional dry skin of subjects with atopic dermatitis, which shows significantly reduced levels of barrier function and ceramide but not of beta-glucocerebrosidase activity. For the first time, we report an abnormal trans-epidermal water loss homeostasis in which delayed recovery kinetics of trans-epidermal water loss occurred on the first day during the 4 days after acute barrier disruption compared with healthy control skin. Interestingly, whereas the higher ceramide level in the stratum corneum of healthy control skin was further significantly up-regulated at 4 days post-tape stripping, the lower ceramide level in the stratum corneum of subjects with atopic dermatitis was not significantly changed. In a parallel study, whereas beta-glucocerebrosidase activity at 4 days post-tape stripping was significantly up-regulated in healthy control skin compared with before tape stripping, the level of that activity remained substantially unchanged in atopic dermatitis. These findings indicate that subjects with atopic dermatitis have a defect in sphingolipid-metabolic processing that generates ceramide in the interface between the stratum corneum and the epidermis. The results also support the notion that the continued disruption of barrier function in atopic dermatitis non-lesional skin is associated with the impaired homeostasis of a ceramide-generating process, which underscores an atopy-specific inflammation-triggered ceramide deficiency that is distinct from other types of dermatitis.

Effect of Standardized Boesenbergia pandurata Extract and Its Active Compound Panduratin A on Skin Hydration and Barrier Function in Human Epidermal Keratinocytes.

PubMed

Woo, Seon Wook; Rhim, Dong-Bin; Kim, Changhee; Hwang, Jae-Kwan

2015-03-01

The skin plays a key role in protecting the body from the environment and from water loss. Cornified envelope (CE) and natural moisturizing factor (NMF) are considered as the primary regulators of skin hydration and barrier function. The CE prevents loss of water from the body and is formed by cross-linking of several proteins. Among these proteins, filaggrin is an important protein because NMF is produced by the degradation of filaggrin. Proteases, including matriptase and prostasin, stimulate the generation of filaggrin from profilaggrin and caspase-14 plays a role in the degradation of filaggrin. This study elucidated the effects of an ethanol extract of Boesenbergia pandurata (Roxb.) Schltr., known as fingerroot, and its active compound panduratin A on CE formation and filaggrin processing in HaCaT, human epidermal keratinocytes. B. pandurata extract (BPE) and panduratin A significantly stimulated not only CE formation but also the expression of CE proteins, such as loricrin, involucrin, and transglutaminase, which were associated with PPARα expression. The mRNA and protein levels of filaggrin and filaggrin-related enzymes, such as matriptase, prostasin, and caspase-14 were also up-regulated by BPE and panduratin A treatment. These results suggest that BPE and panduratin A are potential nutraceuticals which can enhance skin hydration and barrier function based on their CE formation and filaggrin processing.

Using FLIM in the study of permeability barrier function of aged and young skin

NASA Astrophysics Data System (ADS)

Xu, P.; Choi, E. H.; Man, M. Q.; Crumrine, D.; Mauro, T.; Elias, P.

2006-02-01

Aged skin commonly is afflicted by inflammatory skin diseases or xerosis/eczema that can be triggered or exacerbated by impaired epidermal permeability barrier homeostasis. It has been previously described a permeability barrier defect in humans of advanced age (> 75 years), which in a murine analog >18 mos, could be attributed to reduced lipid synthesis synthesis. However, the functional abnormality in moderately aged mice is due not to decreased lipid synthesis, but rather to a specific defect in stratum corneum (SC) acidification causing impaired lipid processing processing. Endogenous Na +/H + antiporter (NHE1) level was found declined in moderately aged mouse epidermis. This acidification defect leads to perturbed permeability barrier homeostasis through more than one pathways, we addressed suboptimal activation of the essential, lipid-processing enzyme, β-glucocerebrosidase (BGC) is linked to elevated SC pH. Finally, the importance of the epidermis acidity is shown by the normalization of barrier function after exogenous acidification of moderately aged skin.

Lipid functions in skin: Differential effects of n-3 polyunsaturated fatty acids on cutaneous ceramides, in a human skin organ culture model.

PubMed

Kendall, Alexandra C; Kiezel-Tsugunova, Magdalena; Brownbridge, Luke C; Harwood, John L; Nicolaou, Anna

2017-09-01

Ceramides are important for skin health, with a multitude of species found in both dermis and epidermis. The epidermis contains linoleic acid-Ester-linked Omega-hydroxylated ceramides of 6-Hydroxy-sphingosine, Sphingosine and Phytosphingosine bases (CER[EOH], CER[EOS] and CER[EOP], respectively), that are crucial for the formation of the epidermal barrier, conferring protection from environmental factors and preventing trans-epidermal water loss. Furthermore, a large number of ceramides, derivatives of the same sphingoid bases and various fatty acids, are produced by dermal and epidermal cells and perform signalling roles in cell functions ranging from differentiation to apoptosis. Supplementation with the n-3 polyunsaturated fatty acids (PUFA) eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) have shown promise as therapeutic agents in a number of inflammatory skin conditions, altering the lipid profile of the skin and production of bioactive lipids such as the eicosanoids, docosanoids and endocannabinoids. In this study we wished to investigate whether EPA and DHA could also affect the ceramide profile in epidermis and dermis, and, in this way, contribute to formation of a robust lipid barrier and ceramide-mediated regulation of skin functions. Ex vivo skin explants were cultured for 6days, and supplemented with EPA or DHA (50μM). Liquid chromatography coupled to tandem mass spectrometry with electrospray ionisation was used to assess the prevalence of 321 individual ceramide species, and a number of sphingoid bases, phosphorylated sphingoid bases, and phosphorylated ceramides, within the dermis and epidermis. EPA augmented dermal production of members of the ceramide families containing Non-hydroxy fatty acids and Sphingosine or Dihydrosphingosine bases (CER[NS] and CER[NDS], respectively), while epidermal CER[EOH], CER[EOS] and CER[EOP] ceramides were not affected. DHA did not significantly affect ceramide production. Ceramide-1-phosphate levels in the epidermis, but not the dermis, increased in response to EPA, but not DHA. This ex vivo study shows that dietary supplementation with EPA has the potential to alter the ceramide profile of the skin, and this may contribute to its anti-inflammatory profile. This has implications for formation of the epidermal lipid barrier, and signalling pathways within the skin mediated by ceramides and other sphingolipid species. This article is part of a Special Issue entitled: Membrane Lipid Therapy: Drugs Targeting Biomembranes edited by Pablo V. Escribá. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

Counterregulation between thymic stromal lymphopoietin- and IL-23-driven immune axes shapes skin inflammation in mice with epidermal barrier defects.

PubMed

Li, Jiagui; Leyva-Castillo, Juan Manuel; Hener, Pierre; Eisenmann, Aurelie; Zaafouri, Sarra; Jonca, Nathalie; Serre, Guy; Birling, Marie-Christine; Li, Mei

2016-07-01

Epidermal barrier dysfunction has been recognized as a critical factor in the initiation and exacerbation of skin inflammation, particularly in patients with atopic dermatitis (AD) and AD-like congenital disorders, including peeling skin syndrome type B. However, inflammatory responses developed in barrier-defective skin, as well as the underlying mechanisms, remained incompletely understood. We aimed to decipher inflammatory axes and the cytokine network in mouse skin on breakdown of epidermal stratum corneum barrier. We generated Cdsn(iep-/-) mice with corneodesmosin ablation in keratinocytes selectively in an inducible manner. We characterized inflammatory responses and cytokine expression by using histology, immunohistochemistry, ELISA, and quantitative PCR. We combined mouse genetic tools, antibody-mediated neutralization, signal-blocking reagents, and topical antibiotic treatment to explore the inflammatory axes. We show that on breakdown of the epidermal stratum corneum barrier, type 2 and type 17 inflammatory responses are developed simultaneously, driven by thymic stromal lymphopoietin (TSLP) and IL-23, respectively. Importantly, we reveal a counterregulation between these 2 inflammatory axes. Furthermore, we show that protease-activated receptor 2 signaling is involved in mediating the TSLP/type 2 axis, whereas skin bacteria are engaged in induction of the IL-23/type 17 axis. Moreover, we find that IL-1β is induced in skin of Cdsn(iep-/-) mice and that blockade of IL-1 signaling suppresses both TSLP and IL-23 expression and ameliorates skin inflammation. The inflammatory phenotype in barrier-defective skin is shaped by counterregulation between the TSLP/type 2 and IL-23/type 17 axes. Targeting IL-1 signaling could be a promising therapeutic option for controlling skin inflammation in patients with peeling skin syndrome type B and other diseases related to epidermal barrier dysfunction, including AD. Copyright © 2016 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.

Skin Barrier Disruption - A Requirement for Allergen Sensitization?

PubMed Central

De Benedetto, Anna; Kubo, Akiharu; Beck, Lisa A.

2011-01-01

For at least half a century, noninvasive techniques have been available to quantify skin barrier function, and these have shown that a number of human skin conditions and disorders are associated with defects in skin permeability. In the last decade, several genes responsible for skin barrier defects observed in both monogenetic and complex, polygenic disorders have been elucidated and functionally characterized. This has led to an explosion of work in the last six years that has identified pathways connecting epidermal barrier disruption and antigen uptake as well as the quality and/or magnitude of the antigen-specific adaptive immune response. This review will introduce the notion that diseases arise from the dynamic crosstalk that occurs between the skin barrier and immune system using atopic dermatitis or eczema as the disease prototype. Nevertheless, the concepts put forth are highly relevant to a number of antigen-driven disorders for which skin barrier is at least transiently compromised such as psoriasis, allergic contact dermatitis and blistering disorders. PMID:22217737

Stratum Corneum Lipids: Their Role for the Skin Barrier Function in Healthy Subjects and Atopic Dermatitis Patients.

PubMed

van Smeden, Jeroen; Bouwstra, Joke A

2016-01-01

Human skin acts as a primary barrier between the body and its environment. Crucial for this skin barrier function is the lipid matrix in the outermost layer of the skin, the stratum corneum (SC). Two of its functions are (1) to prevent excessive water loss through the epidermis and (2) to avoid that compounds from the environment permeate into the viable epidermal and dermal layers and thereby provoke an immune response. The composition of the SC lipid matrix is dominated by three lipid classes: cholesterol, free fatty acids and ceramides. These lipids adopt a highly ordered, 3-dimensional structure of stacked densely packed lipid layers (lipid lamellae): the lateral and lamellar lipid organization. The way in which these lipids are ordered depends on the composition of the lipids. One very common skin disease in which the SC lipid barrier is affected is atopic dermatitis (AD). This review addresses the SC lipid composition and organization in healthy skin, and elaborates on how these parameters are changed in lesional and nonlesional skin of AD patients. Concerning the lipid composition, the changes in the three main lipid classes and the importance of the carbon chain lengths of the lipids are discussed. In addition, this review addresses how these changes in lipid composition induce changes in lipid organization and subsequently correlate with an impaired skin barrier function in both lesional and nonlesional skin of these patients. Furthermore, the effect of filaggrin and mutations in the filaggrin gene on the SC lipid composition is critically discussed. Also, the breakdown products of filaggrin, the natural moisturizing factor molecules and its relation to SC-pH is described. Finally, the paper discusses some major changes in epidermal lipid biosynthesis in patients with AD and other related skin diseases, and how inflammation has a deteriorating effect on the SC lipids and SC biosynthesis. The review ends with perspectives on future studies in relation to other skin diseases. © 2016 S. Karger AG, Basel.

Effect of ingested concentrate and components of sake on epidermal permeability barrier disruption by UVB irradiation.

PubMed

Hirotsune, Masato; Haratake, Akinori; Komiya, Aya; Sugita, Jun; Tachihara, Toru; Komai, Tsuyoshi; Hizume, Kazuhisa; Ozeki, Kenji; Ikemoto, Takeshi

2005-02-23

Daily topical applications of the concentrate of sake (CS) have been shown to reduce epidermal barrier disruption in murine skin caused by ultraviolet B (UVB) radiation, while one of the components of sake, ethyl alpha-D-glucoside (alpha-EG), also reduces barrier disruption. We confirmed the effect of oral ingestion of various doses of CS on epidermal barrier disruption caused by UVB irradiation in hairless mice. Then, to identify the effective components, we quantitatively analyzed alpha-EG, organic acids, and glycerol, the main components of CS, and examined the effect of various concentration of each on barrier disruption. alpha-EG and organic acids showed comparable results to CS itself, and transepidermal water loss levels in murine skin were significantly decreased as compared with the control. Furthermore, an investigation of the dose dependency of these agents was performed and the results showed the significant effectiveness of alpha-EG. In addition, red wine concentrate (WC) and beer concentrate (BC) were examined in order to confirm the unique effects of CS. Similar effects were not found with WC and BC.

Substance P restores normal skin architecture and reduces epidermal infiltration of sensory nerve fiber in TNCB-induced atopic dermatitis-like lesions in NC/Nga mice.

PubMed

Choi, Hyeongwon; Kim, Dong-Jin; Nam, Seungwoo; Lim, Sunki; Hwang, Jae-Sung; Park, Ki Sook; Hong, Hyun Sook; Won, Younsun; Shin, Min Kyung; Chung, Eunkyung; Son, Youngsook

2018-03-01

Atopic dermatitis (AD) is a chronic inflammatory skin disorder characterized by intense pruritus and eczematous lesion. Substance P (SP) is an 11-amino-acid endogenous neuropeptide that belongs to the tachykinin family and several reports recently have supported the anti-inflammatory and tissue repairing roles of SP. In this study, we investigated whether SP can improve AD symptoms, especially the impaired skin barrier function, in 2, 4, 6-trinitrochlorobenzene (TNCB)-induced chronic dermatitis of NC/Nga mice or not. AD-like dermatitis was induced in NC/Nga mice by repeated sensitization with TNCB for 5 weeks. The experimental group designations and topical treatments were as follows: vehicle group (AD-VE); SP group (AD-SP); and SP with NK1R antagonist CP99994 (AD-SP-A) group. Histological analysis was performed to evaluate epidermal differentiation, dermal integrity, and epidermal nerve innervation in AD-like lesions. The skin barrier functions and pruritus of NC/Nga mice were evaluated by measuring transepidermal water loss (TEWL) and scratching behavior, respectively. Topical SP treatment resulted in significant down-regulation of Ki67 and the abnormal-type keratins (K) K6, K16, and K17, restoration of filaggrin and claudin-1, marked reduction of TEWL, and restoration of basement membrane and dermal collagen deposition, even under continuous sensitization of low dose TNCB. In addition, SP significantly reduced innervation of itch-evoking nerve fibers, gelatinase activity and nerve growth factor (NGF) expression in the epidermis but upregulated semaphorin-3A (Sema3A) expression in the epidermis, along with reduced scratching behavior in TNCB-treated NC/Nga mice. All of these effects were completely reversed by co-treatment with the NK1R antagonist CP99994. In cultured human keratinocytes, SP treatment reduced expression of TGF-α, but upregulated TGF-β and Sema3A. Topically administered SP can restore normal skin barrier function, reduce epidermal infiltration of itch-evoking nerve fibers in the AD-like skin lesions, and alleviate scratching behavior. Thus, SP may be proposed as a potential medication for chronic dermatitis and AD. Copyright © 2017 Japanese Society for Investigative Dermatology. Published by Elsevier B.V. All rights reserved.

Effect of Fluid Intake on Hydration Status and Skin Barrier Characteristics in Geriatric Patients: An Explorative Study.

PubMed

Akdeniz, Merve; Boeing, Heiner; Müller-Werdan, Ursula; Aykac, Volkan; Steffen, Annika; Schell, Mareike; Blume-Peytavi, Ulrike; Kottner, Jan

2018-01-01

Inadequate fluid intake is assumed to be a trigger of water-loss dehydration, which is a major health risk in aged and geriatric populations. Thus, there is a need to search for easy to use diagnostic tests to identify dehydration. Our overall aim was to investigate whether skin barrier parameters could be used for predicting fluid intake and/or hydration status in geriatric patients. An explorative observational comparative study was conducted in a geriatric hospital including patients aged 65 years and older. We measured 3-day fluid intake, skin barrier parameters, Overall Dry Skin Score, serum osmolality, cognitive and functional health, and medications. Forty patients were included (mean age 78.45 years and 65% women) with a mean fluid intake of 1,747 mL/day. 20% of the patients were dehydrated and 22.5% had an impending dehydration according to serum osmolality. Multivariate analysis suggested that skin surface pH and epidermal hydration at the face were associated with fluid intake. Serum osmolality was associated with epidermal hydration at the leg and skin surface pH at the face. Fluid intake was not correlated with serum osmolality. Diuretics were associated with high serum osmolality. Approximately half of the patients were diagnosed as being dehydrated according to osmolality, which is the current reference standard. However, there was no association with fluid intake, questioning the clinical relevance of this measure. Results indicate that single skin barrier parameters are poor markers for fluid intake or osmolality. Epidermal hydration might play a role but most probably in combination with other tests. © 2018 S. Karger AG, Basel.

Tight Junction Defects in Atopic Dermatitis

PubMed Central

De Benedetto, Anna; Rafaels, Nicholas M.; McGirt, Laura Y.; Ivanov, Andrei I.; Georas, Steve N.; Cheadle, Chris; Berger, Alan E.; Zhang, Kunzhong; Vidyasagar, Sadasivan; Yoshida, Takeshi; Boguniewicz, Mark; Hata, Tissa; Schneider, Lynda C.; Hanifin, Jon M.; Gallo, Richard L.; Novak, Natalija; Weidinger, Stephan; Beaty, Terri H.; Leung, Donald Y.; Barnes, Kathleen C.; Beck, Lisa A.

2010-01-01

Background Atopic dermatitis (AD) is characterized by dry skin and a hyperreactive immune response to allergens, two cardinal features that are caused in part by epidermal barrier defects. Tight junctions (TJ) reside immediately below the stratum corneum and regulate the selective permeability of the paracellular pathway. Objective We evaluated the expression/function of the TJ protein, claudin-1 in epithelium from AD and nonatopic (NA) subjects and screened two American populations for SNPs in CLDN1. Methods Expression profiles of nonlesional epithelium from extrinsic AD, NA and psoriasis subjects were generated using Illumina’s BeadChips. Dysregulated intercellular proteins were validated by tissue staining and qPCR. Bioelectric properties of epithelium were measured in Ussing chambers. Functional relevance of claudin-1 was assessed using a knockdown approach in primary human keratinocytes (PHK). Twenty seven haplotype-tagging SNPs in CLDN1 were screened in two independent AD populations. Results We observed strikingly reduced expression of the TJ proteins claudin-1 and -23 only in AD, which were validated at the mRNA and protein levels. Claudin-1 expression inversely correlated with Th2 biomarkers. We observed a remarkable impairment of the bioelectric barrier function in AD epidermis. In vitro, we confirmed that silencing claudin-1 expression in human keratinocytes diminishes TJ function while enhancing keratinocyte proliferation. Finally, CLDN1 haplotype-tagging single nucleotide polymorphisms revealed associations with AD in two North American populations. Conclusion Taken together, these data suggest that an impaired epidermal TJ is a novel feature of skin barrier dysfunction and immune dysregulation observed in AD, and that CLDN1 may be a new susceptibility gene in this disease. PMID:21163515

Hyperactivation of JAK1 tyrosine kinase induces stepwise, progressive pruritic dermatitis

PubMed Central

Yasuda, Takuwa; Fukada, Toshiyuki; Nishida, Keigo; Nakayama, Manabu; Matsuda, Masashi; Miura, Ikuo; Fukuda, Shinji; Kabashima, Kenji; Nakaoka, Shinji; Bin, Bum-Ho; Kubo, Masato; Hasegawa, Takanori; Ohara, Osamu; Koseki, Haruhiko; Wakana, Shigeharu

2016-01-01

Skin homeostasis is maintained by the continuous proliferation and differentiation of epidermal cells. The skin forms a strong but flexible barrier against microorganisms as well as physical and chemical insults; however, the physiological mechanisms that maintain this barrier are not fully understood. Here, we have described a mutant mouse that spontaneously develops pruritic dermatitis as the result of an initial defect in skin homeostasis that is followed by induction of a Th2-biased immune response. These mice harbor a mutation that results in a single aa substitution in the JAK1 tyrosine kinase that results in hyperactivation, thereby leading to skin serine protease overexpression and disruption of skin barrier function. Accordingly, treatment with an ointment to maintain normal skin barrier function protected mutant mice from dermatitis onset. Pharmacological inhibition of JAK1 also delayed disease onset. Together, these findings indicate that JAK1-mediated signaling cascades in skin regulate the expression of proteases associated with the maintenance of skin barrier function and demonstrate that perturbation of these pathways can lead to the development of spontaneous pruritic dermatitis. PMID:27111231

Hyperactivation of JAK1 tyrosine kinase induces stepwise, progressive pruritic dermatitis.

PubMed

Yasuda, Takuwa; Fukada, Toshiyuki; Nishida, Keigo; Nakayama, Manabu; Matsuda, Masashi; Miura, Ikuo; Dainichi, Teruki; Fukuda, Shinji; Kabashima, Kenji; Nakaoka, Shinji; Bin, Bum-Ho; Kubo, Masato; Ohno, Hiroshi; Hasegawa, Takanori; Ohara, Osamu; Koseki, Haruhiko; Wakana, Shigeharu; Yoshida, Hisahiro

2016-06-01

Skin homeostasis is maintained by the continuous proliferation and differentiation of epidermal cells. The skin forms a strong but flexible barrier against microorganisms as well as physical and chemical insults; however, the physiological mechanisms that maintain this barrier are not fully understood. Here, we have described a mutant mouse that spontaneously develops pruritic dermatitis as the result of an initial defect in skin homeostasis that is followed by induction of a Th2-biased immune response. These mice harbor a mutation that results in a single aa substitution in the JAK1 tyrosine kinase that results in hyperactivation, thereby leading to skin serine protease overexpression and disruption of skin barrier function. Accordingly, treatment with an ointment to maintain normal skin barrier function protected mutant mice from dermatitis onset. Pharmacological inhibition of JAK1 also delayed disease onset. Together, these findings indicate that JAK1-mediated signaling cascades in skin regulate the expression of proteases associated with the maintenance of skin barrier function and demonstrate that perturbation of these pathways can lead to the development of spontaneous pruritic dermatitis.

Epidermal barrier defects link atopic dermatitis with altered skin cancer susceptibility.

PubMed

Cipolat, Sara; Hoste, Esther; Natsuga, Ken; Quist, Sven R; Watt, Fiona M

2014-05-05

Atopic dermatitis can result from loss of structural proteins in the outermost epidermal layers, leading to a defective epidermal barrier. To test whether this influences tumour formation, we chemically induced tumours in EPI-/- mice, which lack three barrier proteins-Envoplakin, Periplakin, and Involucrin. EPI-/- mice were highly resistant to developing benign tumours when treated with 7,12-dimethylbenz(a)anthracene (DMBA) and 12-O-tetradecanoylphorbol-13-acetate (TPA). The DMBA response was normal, but EPI-/- skin exhibited an exaggerated atopic response to TPA, characterised by abnormal epidermal differentiation, a complex immune infiltrate and elevated serum thymic stromal lymphopoietin (TSLP). The exacerbated TPA response could be normalised by blocking TSLP or the immunoreceptor NKG2D but not CD4+ T cells. We conclude that atopy is protective against skin cancer in our experimental model and that the mechanism involves keratinocytes communicating with cells of the immune system via signalling elements that normally protect against environmental assaults.DOI: http://dx.doi.org/10.7554/eLife.01888.001. Copyright © 2014, Cipolat et al.

Multiple transcription factor codes activate epidermal wound–response genes in Drosophila

PubMed Central

Pearson, Joseph C.; Juarez, Michelle T.; Kim, Myungjin; Drivenes, Øyvind; McGinnis, William

2009-01-01

Wounds in Drosophila and mouse embryos induce similar genetic pathways to repair epidermal barriers. However, the transcription factors that transduce wound signals to repair epidermal barriers are largely unknown. We characterize the transcriptional regulatory enhancers of 4 genes—Ddc, ple, msn, and kkv—that are rapidly activated in epidermal cells surrounding wounds in late Drosophila embryos and early larvae. These epidermal wound enhancers all contain evolutionarily conserved sequences matching binding sites for JUN/FOS and GRH transcription factors, but vary widely in trans- and cis-requirements for these inputs and their binding sites. We propose that the combination of GRH and FOS is part of an ancient wound–response pathway still used in vertebrates and invertebrates, but that other mechanisms have evolved that result in similar transcriptional output. A common, but largely untested assumption of bioinformatic analyses of gene regulatory networks is that transcription units activated in the same spatial and temporal patterns will require the same cis-regulatory codes. Our results indicate that this is an overly simplistic view. PMID:19168633

Development of 3D imaging technique of reconstructed human epidermis with immortalized human epidermal cell line.

PubMed

Inoue, Yu; Hasegawa, Seiji; Miyachi, Katsuma; Yamada, Takaaki; Nakata, Satoru; Ipponjima, Sari; Hibi, Terumasa; Nemoto, Tomomi; Tanaka, Masahiko; Suzuki, Ryo; Hirashima, Naohide

2018-05-01

The epidermis, the outermost layer of the skin, retains moisture and functions as a physical barrier against the external environment. Epidermal cells are continuously replaced by turnover, and thus to understand in detail the dynamic cellular events in the epidermis, techniques to observe live tissues in 3D are required. Here, we established a live 3D imaging technique for epidermis models. We first obtained immortalized human epidermal cell lines which have a normal differentiation capacity and fluorescence-labelled cytoplasm or nuclei. The reconstituted 3D epidermis was prepared with these lines. Using this culture system, we were able to observe the structure of the reconstituted epidermis live in 3D, which was similar to an in vivo epidermis, and evaluate the effect of a skin irritant. This technique may be useful for dermatological science and drug development. © 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

The angiopoietin1-Akt pathway regulates barrier function of the cultured spinal cord microvascular endothelial cells through Eps8.

PubMed

Liu, Xinchun; Zhou, Xiaoshu; Yuan, Wei

2014-10-15

In mammalian central nervous system (CNS), the integrity of the blood-spinal cord barrier (BSCB), formed by tight junctions (TJs) between adjacent microvascular endothelial cells near the basement membrane of capillaries and the accessory structures, is important for relatively independent activities of the cellular constituents inside the spinal cord. The barrier function of the BSCB are tightly regulated and coordinated by a variety of physiological or pathological factors, similar with but not quite the same as its counterpart, the blood-brain barrier (BBB). Herein, angiopoietin 1 (Ang1), an identified ligand of the endothelium-specific tyrosine kinase receptor Tie-2, was verified to regulate barrier functions, including permeability, junction protein interactions and F-actin organization, in cultured spinal cord microvascular endothelial cells (SCMEC) of rat through the activity of Akt. Besides, these roles of Ang1 in the BSCB in vitro were found to be accompanied with an increasing expression of epidermal growth factor receptor pathway substrate 8 (Eps8), an F-actin bundling protein. Furthermore, the silencing of Eps8 by lentiviral shRNA resulted in an antagonistic effect vs. Ang1 on the endothelial barrier function of SCMEC. In summary, the Ang1-Akt pathway serves as a regulator in the barrier function modulation of SCMEC via the actin-binding protein Eps8. Copyright © 2014 Elsevier Inc. All rights reserved.

Gene Targeting of Envoplakin, a Cytoskeletal Linker Protein and Precursor of the Epidermal Cornified Envelope

PubMed Central

Määttä, Arto; DiColandrea, Teresa; Groot, Karen; Watt, Fiona M.

2001-01-01

Envoplakin, a member of the plakin family of cytoskeletal linker proteins, is localized in desmosomes of stratified epithelial cells and is a component of the epidermal cornified envelope. Gene targeting in mouse embryonic stem cells was used to generate a null allele of envoplakin. No envoplakin transcripts from the targeted allele could be detected in the skin of newborn mice. Mice homozygous for the targeted allele were born in the normal Mendelian ratio and were fertile. They did not develop any discernible pathological phenotype up to the age of 1 year. The ultrastructural appearance of cornified envelopes from adult epidermis was indistinguishable between wild-type and knockout mice, and there was no evidence that the absence of envoplakin affected the subcellular distribution of periplakin or desmoplakin, two other plakins found in desmosomes. The proportion of immature cornified envelopes in the epidermis of newborn mice was greater in envoplakin-null animals than in heterozygous littermates or wild-type mice, and the envelopes had a larger surface area. This correlated with a slight delay in barrier acquisition during embryonic development. We conclude that although envoplakin is part of the scaffolding on which the cornified envelope is assembled, it is not essential for envelope formation or epidermal barrier function. PMID:11564887

Src kinases and ERK activate distinct responses to Stitcher receptor tyrosine kinase signaling during wound healing in Drosophila.

PubMed

Tsarouhas, Vasilios; Yao, Liqun; Samakovlis, Christos

2014-04-15

Metazoans have evolved efficient mechanisms for epidermal repair and survival following injury. Several cellular responses and key signaling molecules that are involved in wound healing have been identified in Drosophila, but the coordination of cytoskeletal rearrangements and the activation of gene expression during barrier repair are poorly understood. The Ret-like receptor tyrosine kinase (RTK) Stitcher (Stit, also known as Cad96Ca) regulates both re-epithelialization and transcriptional activation by Grainy head (Grh) to induce restoration of the extracellular barrier. Here, we describe the immediate downstream effectors of Stit signaling in vivo. Drk (Downstream of receptor kinase) and Src family tyrosine kinases bind to the same docking site in the Stit intracellular domain. Drk is required for the full activation of transcriptional responses but is dispensable for re-epithelialization. By contrast, Src family kinases (SFKs) control both the assembly of a contractile actin ring at the wound periphery and Grh-dependent activation of barrier-repair genes. Our analysis identifies distinct pathways mediating injury responses and reveals an RTK-dependent activation mode for Src kinases and their central functions during epidermal wound healing in vivo.

A lactobacillus rhamnosus GG-derived soluble protein, p40, stimulates ligand release from intestinal epithelial cells to transactivate epidermal growth factor receptor

USDA-ARS?s Scientific Manuscript database

Protein p40, a Lactobacillus rhamnosus GG (LGG)-derived soluble protein, ameliorates intestinal injury and colitis, reduces apoptosis and preserves barrier function by activation of EGF receptor (EGFR) in intestinal epithelial cells. The aim of this study was to determine the mechanisms by which p40...

Fisetin Regulates Nrf2 Expression and the Inflammation-Related Signaling Pathway to Prevent UVB-Induced Skin Damage in Hairless Mice.

PubMed

Wu, Po-Yuan; Lyu, Jia-Ling; Liu, Yi-Jung; Chien, Ting-Yi; Hsu, Hao-Cheng; Wen, Kuo-Ching; Chiang, Hsiu-Mei

2017-10-10

Chronic ultraviolet (UV) exposure may cause skin damage, disrupt skin barrier function, and promote wrinkle formation. UV induces oxidative stress and inflammation, which results in extracellular matrix degradation in the dermis and epidermal hyperplasia. Our previous study demonstrated that fisetin exerts photoprotective activity by inhibiting mitogen-activated protein kinase/activator protein-1/matrix metalloproteinases (MMPs) activation. In this study, fisetin was applied topically to investigate its antiphotodamage effects in hairless mice. The erythema index (a* values) and transepidermal water loss were evaluated to assess skin damage, and immunohistochemical staining was conducted to elucidate the photoprotective mechanism of fisetin. The results revealed that the topical application of fisetin reduced UVB-induced increase in the a* value and wrinkle formation. In addition, fisetin inhibited epidermal hyperplasia and increased the collagen content in the dermis. Fisetin exerted photoprotective activity by inhibiting the expression of MMP-1, MMP-2, and cyclooxygenase-2 and increasing the expression of nuclear factor erythroid 2-related factor. Furthermore, fisetin increased the expression of filaggrin to prevent UVB-induced barrier function disruption. Altogether, the present results provide evidence of the effects and mechanisms of fisetin's antiphotodamage and antiphotoinflammation activities.

Fisetin Regulates Nrf2 Expression and the Inflammation-Related Signaling Pathway to Prevent UVB-Induced Skin Damage in Hairless Mice

PubMed Central

Wu, Po-Yuan; Lyu, Jia-Ling; Chien, Ting-Yi; Hsu, Hao-Cheng; Wen, Kuo-Ching

2017-01-01

Chronic ultraviolet (UV) exposure may cause skin damage, disrupt skin barrier function, and promote wrinkle formation. UV induces oxidative stress and inflammation, which results in extracellular matrix degradation in the dermis and epidermal hyperplasia. Our previous study demonstrated that fisetin exerts photoprotective activity by inhibiting mitogen-activated protein kinase/activator protein-1/matrix metalloproteinases (MMPs) activation. In this study, fisetin was applied topically to investigate its antiphotodamage effects in hairless mice. The erythema index (a* values) and transepidermal water loss were evaluated to assess skin damage, and immunohistochemical staining was conducted to elucidate the photoprotective mechanism of fisetin. The results revealed that the topical application of fisetin reduced UVB-induced increase in the a* value and wrinkle formation. In addition, fisetin inhibited epidermal hyperplasia and increased the collagen content in the dermis. Fisetin exerted photoprotective activity by inhibiting the expression of MMP-1, MMP-2, and cyclooxygenase-2 and increasing the expression of nuclear factor erythroid 2-related factor. Furthermore, fisetin increased the expression of filaggrin to prevent UVB-induced barrier function disruption. Altogether, the present results provide evidence of the effects and mechanisms of fisetin’s antiphotodamage and antiphotoinflammation activities. PMID:28994699

iRHOM2-dependent regulation of ADAM17 in cutaneous disease and epidermal barrier function

PubMed Central

Brooke, Matthew A.; Etheridge, Sarah L.; Kaplan, Nihal; Simpson, Charlotte; O'Toole, Edel A.; Ishida-Yamamoto, Akemi; Marches, Olivier; Getsios, Spiro; Kelsell, David P.

2014-01-01

iRHOM2 is a highly conserved, catalytically inactive member of the Rhomboid family, which has recently been shown to regulate the maturation of the multi-substrate ectodomain sheddase enzyme ADAM17 (TACE) in macrophages. Dominant iRHOM2 mutations are the cause of the inherited cutaneous and oesophageal cancer-susceptibility syndrome tylosis with oesophageal cancer (TOC), suggesting a role for this protein in epithelial cells. Here, using tissues derived from TOC patients, we demonstrate that TOC-associated mutations in iRHOM2 cause an increase in the maturation and activity of ADAM17 in epidermal keratinocytes, resulting in significantly upregulated shedding of ADAM17 substrates, including EGF-family growth factors and pro-inflammatory cytokines. This activity is accompanied by increased EGFR activity, increased desmosome processing and the presence of immature epidermal desmosomes, upregulated epidermal transglutaminase activity and heightened resistance to Staphylococcal infection in TOC keratinocytes. Many of these features are consistent with the presence of a constitutive wound-healing-like phenotype in TOC epidermis, which may shed light on a novel pathway in skin repair, regeneration and inflammation. PMID:24643277

In vitro and in vivo assessment of the effect of Laurus novocanariensis oil and essential oil in human skin.

PubMed

Viciolle, E; Castilho, P; Rosado, C

2012-12-01

Laurus novocanariensis is an endemic plant from the Madeira Island forest that derives a fatty oil, with a strong spicy odour, from its berries that has been used for centuries in traditional medicine to treat skin ailments. This work aimed to investigate the effect of the application of both the oil and its essential oil on normal skin, to assess their safety and potential benefits. Diffusion studies with Franz cells using human epidermal membranes were conducted. The steady-state fluxes of two model molecules through untreated skin were compared with those obtained after a 2-h pre-treatment with either the oil or the essential oil. Additionally, eleven volunteers participated in the in vivo study that was conducted on the forearm and involved daily application of the oil for 5 days. Measurements were performed every day in the treated site with bioengineering methods that measure erythema, irritation and loss of barrier function. Slightly higher steady-state fluxes were observed for both the lipophilic and the hydrophilic molecule when the epidermal membranes were pre-treated. Nevertheless, such differences had no statistical significance, which seems to confirm that neither the oil nor the essential oil impaired the epidermal barrier. Results collected with the Chromameter, the Laser Doppler Flowmeter and the visual scoring are in agreement with those established in the in vitro study. They indicate that the repeated application of the oil did not cause erythema, because the results observed in the first day of the study were maintained throughout the week. Application of the oil did not affect the skin barrier function, because the transepidermal water loss remained constant throughout the study. The stratum corneum hydration was slightly reduced on days 4 and 5. This work shows that both the oil and the essential oil were well tolerated by the skin and did not cause significant barrier impairment or irritation. © 2012 Society of Cosmetic Scientists and the Société Française de Cosmétologie.

Pleiotropic Phenotypes of the sticky peel Mutant Provide New Insight into the Role of CUTIN DEFICIENT2 in Epidermal Cell Function in Tomato1[W][OA

PubMed Central

Nadakuduti, Satya Swathi; Pollard, Mike; Kosma, Dylan K.; Allen, Charles; Ohlrogge, John B.; Barry, Cornelius S.

2012-01-01

Plant epidermal cells have evolved specialist functions associated with adaptation to stress. These include the synthesis and deposition of specialized metabolites such as waxes and cutin together with flavonoids and anthocyanins, which have important roles in providing a barrier to water loss and protection against UV radiation, respectively. Characterization of the sticky peel (pe) mutant of tomato (Solanum lycopersicum) revealed several phenotypes indicative of a defect in epidermal cell function, including reduced anthocyanin accumulation, a lower density of glandular trichomes, and an associated reduction in trichome-derived terpenes. In addition, pe mutant fruit are glossy and peels have increased elasticity due to a severe reduction in cutin biosynthesis and altered wax deposition. Leaves of the pe mutant are also cutin deficient and the epicuticular waxes contain a lower proportion of long-chain alkanes. Direct measurements of transpiration, together with chlorophyll-leaching assays, indicate increased cuticular permeability of pe leaves. Genetic mapping revealed that the pe locus represents a new allele of CUTIN DEFICIENT2 (CD2), a member of the class IV homeodomain-leucine zipper gene family, previously only associated with cutin deficiency in tomato fruit. CD2 is preferentially expressed in epidermal cells of tomato stems and is a homolog of Arabidopsis (Arabidopsis thaliana) ANTHOCYANINLESS2 (ANL2). Analysis of cuticle composition in leaves of anl2 revealed that cutin accumulates to approximately 60% of the levels observed in wild-type Arabidopsis. Together, these data provide new insight into the role of CD2 and ANL2 in regulating diverse metabolic pathways and in particular, those associated with epidermal cells. PMID:22623518

Pleiotropic phenotypes of the sticky peel mutant provide new insight into the role of CUTIN DEFICIENT2 in epidermal cell function in tomato.

PubMed

Nadakuduti, Satya Swathi; Pollard, Mike; Kosma, Dylan K; Allen, Charles; Ohlrogge, John B; Barry, Cornelius S

2012-07-01

Plant epidermal cells have evolved specialist functions associated with adaptation to stress. These include the synthesis and deposition of specialized metabolites such as waxes and cutin together with flavonoids and anthocyanins, which have important roles in providing a barrier to water loss and protection against UV radiation, respectively. Characterization of the sticky peel (pe) mutant of tomato (Solanum lycopersicum) revealed several phenotypes indicative of a defect in epidermal cell function, including reduced anthocyanin accumulation, a lower density of glandular trichomes, and an associated reduction in trichome-derived terpenes. In addition, pe mutant fruit are glossy and peels have increased elasticity due to a severe reduction in cutin biosynthesis and altered wax deposition. Leaves of the pe mutant are also cutin deficient and the epicuticular waxes contain a lower proportion of long-chain alkanes. Direct measurements of transpiration, together with chlorophyll-leaching assays, indicate increased cuticular permeability of pe leaves. Genetic mapping revealed that the pe locus represents a new allele of CUTIN DEFICIENT2 (CD2), a member of the class IV homeodomain-leucine zipper gene family, previously only associated with cutin deficiency in tomato fruit. CD2 is preferentially expressed in epidermal cells of tomato stems and is a homolog of Arabidopsis (Arabidopsis thaliana) ANTHOCYANINLESS2 (ANL2). Analysis of cuticle composition in leaves of anl2 revealed that cutin accumulates to approximately 60% of the levels observed in wild-type Arabidopsis. Together, these data provide new insight into the role of CD2 and ANL2 in regulating diverse metabolic pathways and in particular, those associated with epidermal cells.

Recovery Effects of Oral Administration of Glucosylceramide and Beet Extract on Skin Barrier Destruction by UVB in Hairless Mice.

PubMed

Tokudome, Yoshihiro; Masutani, Noriomi; Uchino, Shohei; Fukai, Hisano

2017-10-27

Purified glucosylceramide from beet extract (beet GlcCer) and beet extract containing an equal amount of GlcCer were administered orally to ultra violet B (UVB)-irradiated mice, and differences in the protective effects against skin barrier dysfunction caused by UVB irradiation were compared. In the beet GlcCer group, epidermal thickening and the decrease in stratum corneum (SC) ceramide content caused by UVB irradiation were reduced. In the group that was orally administered beet extract containing glucosylceramide, effects similar to those in the beet GlcCer group were observed. Oral administration of beet GlcCer had no obvious effects against an increase in TEWL or decrease in SC water content after UVB irradiation, but there was improvement in the beet extract group. Oral administration of beet GlcCer is effective in improving skin barrier function in UVB-irradiated mice. Beet extract contains constituents other than GlcCer that are also effective in improving skin barrier function.

Fabrication of Waterproof, Breathable Composite Liquid Dressing and Its Application in Diabetic Skin Ulcer Repair.

PubMed

Xia, Dong-Lin; Chen, Yan-Pei; Wang, Yu-Fei; Li, Xiao-Dong; Bao, Ning; He, Hong; Gu, Hai-Ying

2016-11-01

Diabetic patients are at increased risk of severe skin infections. Covering the wound as early as possible can prevent infection and shorten the course of treatment. In this study, the authors fabricated a waterproof and breathable composite liquid dressing (CLD) that formed a barrier to bacteria and shortened healing time of diabetic rat skin ulcers. The CLD was prepared in a formulation that, on evaporation of the liquid carrier, acts as a waterproof, breathable coating on injured skin. The coating was analyzed for water resistance, moisture vapor transmission rate (MVTR), bacterial barrier properties, sustained-release function, and biosafety. A chemically induced rat model of diabetic foot ulcers was used to examine the wound healing effect of CLD and CLD that contained Dermlin (Yensen Biotech Co, Jiangyin, Jiangsu, China). The wound healing rate, histologic changes, and epidermal growth factor expression were also evaluated. The CLD functioned as an effective barrier against infection, was waterproof, had a suitable MVTR, and had effective biosafety. The synergistic effects of CLD and Dermlin had a rapid wound closure rate. Histologic analysis and measurement of epidermal growth factor expression through an in vivo test revealed that the possible mechanism of the CLD effects included the reduction of inflammation and promotion of cell proliferation. Early treatment with the CLD can prevent infection. In combination with Dermlin, the CLD may promote better wound closure in diabetic skin ulcers. The authors' study suggests a novel strategy for ulcer healing.

Transport barriers made of cutin, suberin and associated waxes.

PubMed

Schreiber, Lukas

2010-10-01

Cutinized leaf epidermal cells and suberized root cell walls form important lipophilic interfaces between the plant and its environment, significantly contributing to the regulation of water uptake and the transport of solutes in and out of the plant. A wealth of new molecular information on the genes and enzymes contributing to cutin, suberin and wax biosynthesis have become available within the past few years, which is examined in the context of the functional properties of these barriers in terms of transport and permeability. Recent progress made in measuring transport properties of cutinized and suberized barriers in plants is reviewed, and promising approaches obtained with Arabidopsis and potato that might link the molecular information with transport properties are suggested. Copyright © 2010 Elsevier Ltd. All rights reserved.

Epidermal hyperproliferation in mice lacking fatty acid transport protein 4 (FATP4) involves ectopic EGF receptor and STAT3 signaling

PubMed Central

Lin, Meei-Hua; Chang, Kuo-Wei; Lin, Shu-Chun; Miner, Jeffrey H.

2010-01-01

Fatty acid transport protein (FATP) 4 is one of a family of six FATPs that facilitate long- and very long-chain fatty acid uptake. Mice lacking FATP4 are born with tight, thick skin and a defective epidermal barrier; they die neonatally due to dehydration and restricted movements. Both the skin phenotype and the lethality are rescued by transgene-driven expression of FATP4 solely in suprabasal keratinocytes. Here we show that Fatp4 mutants exhibit epidermal hyperplasia resulting from an increased number of proliferating suprabasal cells. In addition, barrier formation initiates precociously but never progresses to completion. To investigate possible mechanisms whereby Fatp4 influences skin development, we identified misregulated genes in Fatp4 mutants. Remarkably, three members of the epidermal growth factor (EGF) family (Ereg, Areg, and Epgn) showed increased expression that was associated with elevated epidermal activation of the EGF receptor (EGFR) and STAT3, a downstream effector of EGFR signaling. Both Tyrphostin AG1478, an EGFR tyrosine kinase inhibitor, and curcumin, an inhibitor of both STAT3 and EGFR, attenuated STAT3 activation/nuclear translocation, reduced skin thickening, and partially suppressed the barrier abnormalities. These data identify FATP4 activity as negatively influencing EGFR activation and the resulting STAT3 signaling during normal skin development. These findings have important implications for understanding the pathogenesis of ichthyosis prematurity syndrome, a disease recently shown to be caused by FATP4 mutations. PMID:20513444

Defects of filaggrin-like proteins in both lesional and nonlesional atopic skin.

PubMed

Pellerin, Laurence; Henry, Julie; Hsu, Chiung-Yueh; Balica, Stéfana; Jean-Decoster, Catherine; Méchin, Marie-Claire; Hansmann, Britta; Rodriguez, Elke; Weindinger, Stefan; Schmitt, Anne-Marie; Serre, Guy; Paul, Carle; Simon, Michel

2013-04-01

Atopic dermatitis (AD) is a chronic inflammatory skin disease characterized by a disturbed epidermal barrier. In a subset of patients, this is explained by nonsense mutations in the gene encoding filaggrin (FLG). We sought to evaluate the respective role of FLG mutations and proinflammatory cytokines and to assess the expression of FLG, hornerin (HRNR), and FLG2, 2 FLG-like proteins, which are involved in epidermal barrier functions, in normal skin and both lesional and nonlesional skin of patients with AD. An FLG-genotyped cohort of 73 adults with AD and 73 aged-matched control subjects was analyzed by using immunohistochemistry and immunoblotting. Normal primary human keratinocytes were differentiated in either the absence or presence of IL-4, IL-13, and IL-25. Compared with control subjects, FLG, HRNR, and FLG2 were detected at significantly lower levels in the skin of patients with AD, irrespective of their FLG genotype. The reduction was greater in lesional compared with nonlesional skin. In addition, the proFLG/FLG ratio was found to be higher in the skin of wild-type patients than in control subjects. Cytokine treatment of keratinocytes induced a dramatic reduction in FLG, FLG2, and HRNR expression both at the mRNA and protein levels. The stratum corneum of lesional but also clinically unaffected skin of adults with AD is abnormal, with reduced expression of FLG and FLG-like proteins. In addition to nonsense mutations, proinflammatory cytokines and some defects in the proFLG processing can contribute to the FLG downregulation. Our study suggests that skin inflammation reduces the expression of FLG-like proteins, contributing to the AD-related epidermal barrier dysfunction. Copyright © 2013 American Academy of Allergy, Asthma & Immunology. Published by Mosby, Inc. All rights reserved.

iRHOM2-dependent regulation of ADAM17 in cutaneous disease and epidermal barrier function.

PubMed

Brooke, Matthew A; Etheridge, Sarah L; Kaplan, Nihal; Simpson, Charlotte; O'Toole, Edel A; Ishida-Yamamoto, Akemi; Marches, Olivier; Getsios, Spiro; Kelsell, David P

2014-08-01

iRHOM2 is a highly conserved, catalytically inactive member of the Rhomboid family, which has recently been shown to regulate the maturation of the multi-substrate ectodomain sheddase enzyme ADAM17 (TACE) in macrophages. Dominant iRHOM2 mutations are the cause of the inherited cutaneous and oesophageal cancer-susceptibility syndrome tylosis with oesophageal cancer (TOC), suggesting a role for this protein in epithelial cells. Here, using tissues derived from TOC patients, we demonstrate that TOC-associated mutations in iRHOM2 cause an increase in the maturation and activity of ADAM17 in epidermal keratinocytes, resulting in significantly upregulated shedding of ADAM17 substrates, including EGF-family growth factors and pro-inflammatory cytokines. This activity is accompanied by increased EGFR activity, increased desmosome processing and the presence of immature epidermal desmosomes, upregulated epidermal transglutaminase activity and heightened resistance to Staphylococcal infection in TOC keratinocytes. Many of these features are consistent with the presence of a constitutive wound-healing-like phenotype in TOC epidermis, which may shed light on a novel pathway in skin repair, regeneration and inflammation. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Mutations in ABCA12 Underlie the Severe Congenital Skin Disease Harlequin Ichthyosis

PubMed Central

Kelsell, David P.; Norgett, Elizabeth E.; Unsworth, Harriet; Teh, Muy-Teck; Cullup, Thomas; Mein, Charles A.; Dopping-Hepenstal, Patricia J.; Dale, Beverly A.; Tadini, Gianluca; Fleckman, Philip; Stephens, Karen G.; Sybert, Virginia P.; Mallory, Susan B.; North, Bernard V.; Witt, David R.; Sprecher, Eli; E. M. Taylor, Aileen; Ilchyshyn, Andrew; Kennedy, Cameron T.; Goodyear, Helen; Moss, Celia; Paige, David; Harper, John I.; Young, Bryan D.; Leigh, Irene M.; Eady, Robin A. J.; O’Toole, Edel A.

2005-01-01

Harlequin ichthyosis (HI) is the most severe and frequently lethal form of recessive congenital ichthyosis. Although defects in lipid transport, protein phosphatase activity, and differentiation have been described, the genetic basis underlying the clinical and cellular phenotypes of HI has yet to be determined. By use of single-nucleotide–polymorphism chip technology and homozygosity mapping, a common region of homozygosity was observed in five patients with HI in the chromosomal region 2q35. Sequencing of the ABCA12 gene, which maps within the minimal region defined by homozygosity mapping, revealed disease-associated mutations, including large intragenic deletions and frameshift deletions in 11 of the 12 screened individuals with HI. Since HI epidermis displays abnormal lamellar granule formation, ABCA12 may play a critical role in the formation of lamellar granules and the discharge of lipids into the intercellular spaces, which would explain the epidermal barrier defect seen in this disorder. This finding paves the way for early prenatal diagnosis. In addition, functional studies of ABCA12 will lead to a better understanding of epidermal differentiation and barrier formation. PMID:15756637

Surfactants have multi-fold effects on skin barrier function.

PubMed

Lemery, Emmanuelle; Briançon, Stéphanie; Chevalier, Yves; Oddos, Thierry; Gohier, Annie; Boyron, Olivier; Bolzinger, Marie-Alexandrine

2015-01-01

The stratum corneum (SC) is responsible for the barrier properties of the skin and the role of intercorneocyte skin lipids, particularly their structural organization, in controlling SC permeability is acknowledged. Upon contacting the skin, surfactants interact with the SC components leading to barrier damage. To improve knowledge of the effect of several classes of surfactant on skin barrier function at three different levels. The influence of treatments of human skin explants with six non-ionic and four ionic surfactant solutions on the physicochemical properties of skin was investigated. Skin surface wettability and polarity were assessed through contact angle measurements. Infrared spectroscopy allowed monitoring the SC lipid organization. The lipid extraction potency of surfactants was evaluated thanks to HPLC-ELSD assays. One anionic and one cationic surfactant increased the skin polarity by removing the sebaceous and epidermal lipids and by disturbing the organization of the lipid matrix. Another cationic surfactant displayed a detergency effect without disturbing the skin barrier. Several non-ionic surfactants disturbed the lipid matrix organization and modified the skin wettability without any extraction of the skin lipids. Finally two non-ionic surfactants did not show any effect on the investigated parameters or on the skin barrier. The polarity, the organization of the lipid matrix and the lipid composition of the skin allowed describing finely how surfactants can interact with the skin and disturb the skin barrier function.

Protease and Protease-Activated Receptor-2 Signaling in the Pathogenesis of Atopic Dermatitis

PubMed Central

Lee, Sang Eun; Jeong, Se Kyoo

2010-01-01

Proteases in the skin are essential to epidermal permeability barrier homeostasis. In addition to their direct proteolytic effects, certain proteases signal to cells by activating protease-activated receptors (PARs), the G-protein-coupled receptors. The expression of functional PAR-2 on human skin and its role in inflammation, pruritus, and skin barrier homeostasis have been demonstrated. Atopic dermatitis (AD) is a multifactorial inflammatory skin disease characterized by genetic barrier defects and allergic inflammation, which is sustained by gene-environmental interactions. Recent studies have revealed aberrant expression and activation of serine proteases and PAR-2 in the lesional skin of AD patients. The imbalance between proteases and protease inhibitors associated with genetic defects in the protease/protease inhibitor encoding genes, increase in skin surface pH, and exposure to proteolytically active allergens contribute to this aberrant protease/PAR-2 signaling in AD. The increased protease activity in AD leads to abnormal desquamation, degradation of lipid-processing enzymes and antimicrobial peptides, and activation of primary cytokines, thereby leading to permeability barrier dysfunction, inflammation, and defects in the antimicrobial barrier. Moreover, up-regulated proteases stimulate PAR-2 in lesional skin of AD and lead to the production of cytokines and chemokines involved in inflammation and immune responses, itching sensation, and sustained epidermal barrier perturbation with easier allergen penetration. In addition, PAR-2 is an important sensor for exogenous danger molecules, such as exogenous proteases from various allergens, and plays an important role in AD pathogenesis. Together, these findings suggest that protease activity or PAR-2 may be a future target for therapeutic intervention for the treatment of AD. PMID:20879045

Potential Applications of Phyto-Derived Ceramides in Improving Epidermal Barrier Function.

PubMed

Tessema, Efrem N; Gebre-Mariam, Tsige; Neubert, Reinhard H H; Wohlrab, Johannes

2017-01-01

The outer most layer of the skin, the stratum corneum, consists of corneocytes which are coated by a cornified envelope and embedded in a lipid matrix of ordered lamellar structure. It is responsible for the skin barrier function. Ceramides (CERs) are the backbone of the intercellular lipid membranes. Skin diseases such as atopic dermatitis and psoriasis and aged skin are characterized by dysfunctional skin barrier and dryness which are associated with reduced levels of CERs. Previously, the effectiveness of supplementation of synthetic and animal-based CERs in replenishing the depleted natural skin CERs and restoring the skin barrier function have been investigated. Recently, however, the barrier function improving effect of plant-derived CERs has attracted much attention. Phyto-derived CERs (phytoCERs) are preferable due to their assumed higher safety as they are mostly isolated from dietary sources. The beneficial effects of phytoCER-based oral dietary supplements for skin hydration and skin barrier reinforcement have been indicated in several studies involving animal models as well as human subjects. Ingestible dietary supplements containing phytoCERs are also widely available on the market. Nonetheless, little effort has been made to investigate the potential cosmetic applications of topically administered phytoCERs. Therefore, summarizing the foregoing investigations and identifying the gap in the scientific data on plant-derived CERs intended for skin-health benefits are of paramount importance. In this review, an attempt is made to synthesize the information available in the literature regarding the effects of phytoCER-based oral dietary supplements on skin hydration and barrier function with the underlying mechanisms. © 2017 S. Karger AG, Basel.

Matriptase initiates epidermal prokallikrein activation and disease onset in a mouse model of Netherton syndrome

PubMed Central

Sales, Katiuchia Uzzun; Masedunskas, Andrius; Bey, Alexandra L.; Rasmussen, Amber; Weigert, Roberto; List, Karin; Szabo, Roman; Overbeek, Paul A.; Bugge, Thomas H.

2010-01-01

Deficiency in the serine protease inhibitor LEKTI is the etiological origin of Netherton syndrome. The principal morbidities of the disease are stratum corneum detachment and chronic inflammation. We show that the membrane protease, matriptase, initiates Netherton syndrome in a LEKTI-deficient mouse model by premature activation of a pro-kallikrein-related cascade. Auto-activation of pro-inflammatory and stratum corneum detachment-associated pro-kallikrein-related peptidases was either low or undetectable, but they were efficiently activated by matriptase. Ablation of matriptase from LEKTI-deficient mice dampened inflammation, eliminated aberrant protease activity, prevented stratum corneum detachment, and improved epidermal barrier function. The study uncovers a pathogenic matriptase-pro-kallikrein pathway that could be operative in several human skin and inflammatory diseases. PMID:20657595

A Mixture of Extracts of Kochia scoparia and Rosa multiflora with PPAR α/γ Dual Agonistic Effects Prevents Photoaging in Hairless Mice

PubMed Central

Jeon, Hyerin; Kim, Dong Hye; Nho, Youn-Hwa; Park, Ji-Eun; Kim, Su-Nam; Choi, Eung Ho

2016-01-01

Activation of peroxisome proliferator-activated receptors (PPAR) α/γ is known to inhibit the increases in matrix metalloproteinase (MMP) and reactive oxygen species (ROS) induced by ultraviolet light (UV). Extracts of natural herbs, such as Kochia scoparia and Rosa multiflora, have a PPAR α/γ dual agonistic effect. Therefore, we investigated whether and how they have an antiaging effect on photoaging skin. Eighteen-week-old hairless mice were irradiated with UVA 14 J/cm2 and UVB 40 mJ/cm2 three times a week for 8 weeks. A mixture of extracts of Kochia scoparia and Rosa multiflora (KR) was topically applied on the dorsal skin of photoaging mice twice a day for 8 weeks. Tesaglitazar, a known PPAR α/γ agonist, and vehicle (propylene glycol:ethanol = 7:3, v/v) were applied as positive and negative controls, respectively. Dermal effects (including dermal thickness, collagen density, dermal expression of procollagen 1 and collagenase 13) and epidermal effects (including skin barrier function, epidermal proliferation, epidermal differentiation, and epidermal cytokines) were measured and compared. In photoaging murine skin, KR resulted in a significant recovery of dermal thickness as well as dermal fibroblasts, although it did not change dermal collagen density. KR increased the expression of dermal transforming growth factor (TGF)-β. The dermal effects of KR were explained by an increase in procollagen 1 expression, induced by TGF-β, and a decrease in MMP-13 expression. KR did not affect basal transepidermal water loss (TEWL) or stratum corneum (SC) integrity, but did decrease SC hydration. It also did not affect epidermal proliferation or epidermal differentiation. KR decreased the expression of epidermal interleukin (IL)-1α. Collectively, KR showed possible utility as a therapeutic agent for photoaging skin, with few epidermal side effects such as epidermal hyperplasia or poor differentiation. PMID:27854351

A Mixture of Extracts of Kochia scoparia and Rosa multiflora with PPAR α/γ Dual Agonistic Effects Prevents Photoaging in Hairless Mice.

PubMed

Jeon, Hyerin; Kim, Dong Hye; Nho, Youn-Hwa; Park, Ji-Eun; Kim, Su-Nam; Choi, Eung Ho

2016-11-16

Activation of peroxisome proliferator-activated receptors (PPAR) α/γ is known to inhibit the increases in matrix metalloproteinase (MMP) and reactive oxygen species (ROS) induced by ultraviolet light (UV). Extracts of natural herbs, such as Kochia scoparia and Rosa multiflora , have a PPAR α/γ dual agonistic effect. Therefore, we investigated whether and how they have an antiaging effect on photoaging skin. Eighteen-week-old hairless mice were irradiated with UVA 14 J/cm² and UVB 40 mJ/cm² three times a week for 8 weeks. A mixture of extracts of Kochia scoparia and Rosa multiflora (KR) was topically applied on the dorsal skin of photoaging mice twice a day for 8 weeks. Tesaglitazar, a known PPAR α/γ agonist, and vehicle (propylene glycol:ethanol = 7:3, v / v ) were applied as positive and negative controls, respectively. Dermal effects (including dermal thickness, collagen density, dermal expression of procollagen 1 and collagenase 13) and epidermal effects (including skin barrier function, epidermal proliferation, epidermal differentiation, and epidermal cytokines) were measured and compared. In photoaging murine skin, KR resulted in a significant recovery of dermal thickness as well as dermal fibroblasts, although it did not change dermal collagen density. KR increased the expression of dermal transforming growth factor (TGF)-β. The dermal effects of KR were explained by an increase in procollagen 1 expression, induced by TGF-β, and a decrease in MMP-13 expression. KR did not affect basal transepidermal water loss (TEWL) or stratum corneum (SC) integrity, but did decrease SC hydration. It also did not affect epidermal proliferation or epidermal differentiation. KR decreased the expression of epidermal interleukin (IL)-1α. Collectively, KR showed possible utility as a therapeutic agent for photoaging skin, with few epidermal side effects such as epidermal hyperplasia or poor differentiation.

Longitudinal evaluation of the skin microbiome and association with microenvironment and treatment in canine atopic dermatitis

PubMed Central

Bradley, Charles W.; Morris, Daniel O.; Rankin, Shelley C.; Cain, Christine L.; Misic, Ana M.; Houser, Timothy; Mauldin, Elizabeth A.; Grice, Elizabeth A.

2016-01-01

Host-microbe interactions may play a fundamental role in the pathogenesis of atopic dermatitis (AD), a chronic relapsing inflammatory skin disorder characterized by universal colonization with Staphylococcus. To examine the relationship between epidermal barrier function and the cutaneous microbiota in AD, this study employed a spontaneous model of canine AD (cAD). In a cohort of 14 dogs with cAD, the skin microbiota was longitudinally evaluated with parallel assessment of skin barrier function at disease flare, during antimicrobial therapy and posttherapy. Sequencing of the bacterial 16S ribosomal RNA gene revealed decreased bacterial diversity and increased proportions of Staphylococcus (S. pseudintermedius in particular) and Corynebacterium in comparison to a cohort of healthy control dogs (n=16). Treatment restored bacterial diversity with decreased Staphylococcus proportions, concurrent with decreased cAD severity. Skin barrier function, as measured by corneometry, pH, and transepidermal water loss (TEWL) also normalized with treatment. Bacterial diversity correlated with TEWL and pH, but not corneometry. These findings provide insights into the relationship between the cutaneous microbiome and skin barrier function in AD, the impact of antimicrobial therapy on the skin microbiome, and highlight the utility of cAD as a spontaneous non-rodent model of AD. PMID:26854488

Epidermal cell turnover across tight junctions based on Kelvin's tetrakaidecahedron cell shape

PubMed Central

Yokouchi, Mariko; Atsugi, Toru; van Logtestijn, Mark; Tanaka, Reiko J; Kajimura, Mayumi; Suematsu, Makoto; Furuse, Mikio; Amagai, Masayuki; Kubo, Akiharu

2016-01-01

In multicellular organisms, cells adopt various shapes, from flattened sheets of endothelium to dendritic neurons, that allow the cells to function effectively. Here, we elucidated the unique shape of cells in the cornified stratified epithelia of the mammalian epidermis that allows them to achieve homeostasis of the tight junction (TJ) barrier. Using intimate in vivo 3D imaging, we found that the basic shape of TJ-bearing cells is a flattened Kelvin's tetrakaidecahedron (f-TKD), an optimal shape for filling space. In vivo live imaging further elucidated the dynamic replacement of TJs on the edges of f-TKD cells that enables the TJ-bearing cells to translocate across the TJ barrier. We propose a spatiotemporal orchestration model of f-TKD cell turnover, where in the classic context of 'form follows function', cell shape provides a fundamental basis for the barrier homeostasis and physical strength of cornified stratified epithelia. DOI: http://dx.doi.org/10.7554/eLife.19593.001 PMID:27894419

Moisturizing and Antiinflammatory Properties of Cosmetic Formulations Containing Centella asiatica Extract

PubMed Central

Ratz-Łyko, A.; Arct, J.; Pytkowska, K.

2016-01-01

Centella asiatica extract is a rich source of natural bioactive substances, triterpenoid saponins, flavonoids, phenolic acids, triterpenic steroids, amino acids and sugars. Thus, many scavenging free radicals, exhibit antiinflammatory activity and affect on the stratum corneum hydration and epidermal barrier function. The aim of the present study was to evaluate the in vivo moisturizing and antiinflammatory properties of cosmetic formulations (oil-in-water emulsion cream and hydrogel) containing different concentrations of Centella asiatica extract. The study was conducted over four weeks on a group of 25 volunteers after twice a day application of cosmetic formulations with Centella asiatica extract (2.5 and 5%, w/w) on their forearms. The measurement of basic skin parameters (stratum corneum hydration and epidermal barrier function) was performed once a week. The in vivo antiinflammatory activity based on the methyl nicotinate model of microinflammation in human skin was evaluated after four weeks application of tested formulations. In vivo tests formulations containing 5% of Centella asiatica extract showed the best efficacy in improving skin moisture by increase of skin surface hydration state and decrease in transepidermal water loss as well as exhibited antiinflammatory properties based on the methyl nicotinate model of microinflammation in human skin. Comparative tests conducted by corneometer, tewameter and chromameter showed that cosmetic formulations containing Centella asiatica extract have the moisturizing and antiinflammatory properties. PMID:27168678

Inhibitory effect of Paeonia lactiflora Pallas extract (PE) on poly (I:C)-induced immune response of epidermal keratinocytes.

PubMed

Choi, Mi-Ra; Choi, Dae-Kyoung; Sohn, Kyung-Cheol; Lim, Seul Ki; Kim, Dong-Il; Lee, Young Ho; Im, Myung; Lee, Young; Seo, Young-Joon; Kim, Chang Deok; Lee, Jeung-Hoon

2015-01-01

Epidermal keratinocytes provide protective role against external stimuli by barrier formation. In addition, kertinocytes exerts their role as the defense cells via activation of innate immunity. Disturbance of keratinocyte functions is related with skin disorders. Psoriasis is a common skin disease related with inflammatory reaction in epidermal cells. We attempted to find therapeutics for psoriasis, and found that Paeonia lactiflora Pallas extract (PE) has an inhibitory potential on poly (I:C)-induced inflammation of keratinocytes. PE significantly inhibited poly (I:C)-induced expression of crucial psoriatic cytokines, such as IL-6, IL-8, CCL20 and TNF-α, via down-regulation of NF-κB signaling pathway in human keratinocytes. In addition, PE significantly inhibited poly (I:C)-induced inflammasome activation, in terms of IL-1β and caspase-1 secretion. Finally, PE markedly inhibited poly (I:C)-increased NLRP3, an important component of inflammasome. These results indicate that PE has an inhibitory effect on poly (I:C)-induced inflammatory reaction of keratinocytes, suggesting that PE can be developed for the treatment of psoriasis.

Epithelial cell kinase-B61: an autocrine loop modulating intestinal epithelial migration and barrier function.

PubMed

Rosenberg, I M; Göke, M; Kanai, M; Reinecker, H C; Podolsky, D K

1997-10-01

Epithelial cell kinase (Eck) is a member of a large family of receptor tyrosine kinases whose functions remain largely unknown. Expression and regulation of Eck and its cognate ligand B61 were analyzed in the human colonic adenocarcinoma cell line Caco-2. Immunocytochemical staining demonstrated coexpression of Eck and B61 in the same cells, suggestive of an autocrine loop. Eck levels were maximal in preconfluent cells. In contrast, B61 levels were barely detectable in preconfluent cells and increased progressively after the cells reached confluence. Caco-2 cells cultured in the presence of added B61 showed a significant reduction in the levels of dipeptidyl peptidase and sucrase-isomaltase mRNA, markers of Caco-2 cell differentiation. Cytokines interleukin-1beta (IL-1beta), basic fibroblast growth factor, IL-2, epidermal growth factor, and transforming growth factor-beta modulated steady-state levels of Eck and B61 mRNA and regulated Eck activation as assessed by tyrosine phosphorylation. Functionally, stimulation of Eck by B61 resulted in increased proliferation, enhanced barrier function, and enhanced restitution of injured epithelial monolayers. These results suggest that the Eck-B61 interaction, a target of regulatory peptides, plays a role in intestinal epithelial cell development, migration, and barrier function, contributing to homeostasis and preservation of continuity of the epithelial barrier.

Management of Patients with Atopic Dermatitis: The Role of Emollient Therapy

PubMed Central

Catherine Mack Correa, M.; Nebus, Judith

2012-01-01

Atopic dermatitis is a common inflammatory skin disorder that afflicts a growing number of young children. Genetic, immune, and environmental factors interact in a complex fashion to contribute to disease expression. The compromised stratum corneum found in atopic dermatitis leads to skin barrier dysfunction, which results in aggravation of symptoms by aeroallergens, microbes, and other insults. Infants—whose immune system and epidermal barrier are still developing—display a higher frequency of atopic dermatitis. Management of patients with atopic dermatitis includes maintaining optimal skin care, avoiding allergic triggers, and routinely using emollients to maintain a hydrated stratum corneum and to improve barrier function. Flares of atopic dermatitis are often managed with courses of topical corticosteroids or calcineurin inhibitors. This paper discusses the role of emollients in the management of atopic dermatitis, with particular emphasis on infants and young children. PMID:23008699

PNPLA1 Deficiency in Mice and Humans Leads to a Defect in the Synthesis of Omega-O-Acylceramides

PubMed Central

Grond, Susanne; Eichmann, Thomas O.; Dubrac, Sandrine; Kolb, Dagmar; Schmuth, Matthias; Fischer, Judith; Crumrine, Debra; Elias, Peter M.; Haemmerle, Guenter; Zechner, Rudolf; Lass, Achim; Radner, Franz P.W.

2017-01-01

Mutations in PNPLA1 have been identified as causative for autosomal recessive congenital ichthyosis in humans and dogs. So far, the underlying molecular mechanisms are unknown. In this study, we generated and characterized PNPLA1-deficient mice and found that PNPLA1 is crucial for epidermal sphingolipid synthesis. The absence of functional PNPLA1 in mice impaired the formation of omega-O-acylceramides and led to an accumulation of nonesterified omega-hydroxy-ceramides. As a consequence, PNPLA1-deficient mice lacked a functional corneocyte-bound lipid envelope leading to a severe skin barrier defect and premature death of newborn animals. Functional analyses of differentiated keratinocytes from a patient with mutated PNPLA1 demonstrated an identical defect in omega-O-acylceramide synthesis in human cells, indicating that PNPLA1 function is conserved among mammals and indispensable for normal skin physiology. Notably, topical application of epidermal lipids from wild-type onto Pnpla1-mutant mice promoted rebuilding of the corneocyte-bound lipid envelope, indicating that supplementation of ichthyotic skin with omega-O-acylceramides might be a therapeutic approach for the treatment of skin symptoms in individuals affected by omega-O-acylceramide deficiency. PMID:27751867

The Herbal Bitter Drug Gentiana lutea Modulates Lipid Synthesis in Human Keratinocytes In Vitro and In Vivo

PubMed Central

Haarhaus, Birgit; Seiwerth, Jasmin; Cawelius, Anja; Schwabe, Kay; Quirin, Karl-Werner; Schempp, Christoph M.

2017-01-01

Gentiana lutea is a herbal bitter drug that is used to enhance gastrointestinal motility and secretion. Recently we have shown that amarogentin, a characteristic bitter compound of Gentiana lutea extract (GE), binds to the bitter taste receptors TAS2R1 and TAS2R38 in human keratinocytes, and stimulates the synthesis of epidermal barrier proteins. Here, we wondered if GE also modulates lipid synthesis in human keratinocytes. To address this issue, human primary keratinocytes were incubated for 6 days with GE. Nile Red labeling revealed that GE significantly increased lipid synthesis in keratinocytes. Similarly, gas chromatography with flame ionization detector indicated that GE increases the amount of triglycerides in keratinocytes. GE induced the expression of epidermal ceramide synthase 3, but not sphingomyelinase. Lipid synthesis, as well as ceramide synthase 3 expression, could be specifically blocked by inhibitors of the p38 MAPK and PPARγ signaling pathway. To assess if GE also modulates lipid synthesis in vivo, we performed a proof of concept half side comparison on the volar forearms of 33 volunteers. In comparison to placebo, GE significantly increased the lipid content of the treated skin areas, as measured with a sebumeter. Thus, GE enhances lipid synthesis in human keratinocytes that is essential for building an intact epidermal barrier. Therefore, GE might be used to improve skin disorders with an impaired epidermal barrier, e.g., very dry skin and atopic eczema. PMID:28829355

The Herbal Bitter Drug Gentiana lutea Modulates Lipid Synthesis in Human Keratinocytes In Vitro and In Vivo.

PubMed

Wölfle, Ute; Haarhaus, Birgit; Seiwerth, Jasmin; Cawelius, Anja; Schwabe, Kay; Quirin, Karl-Werner; Schempp, Christoph M

2017-08-22

Gentiana lutea is a herbal bitter drug that is used to enhance gastrointestinal motility and secretion. Recently we have shown that amarogentin, a characteristic bitter compound of Gentiana lutea extract (GE), binds to the bitter taste receptors TAS2R1 and TAS2R38 in human keratinocytes, and stimulates the synthesis of epidermal barrier proteins. Here, we wondered if GE also modulates lipid synthesis in human keratinocytes. To address this issue, human primary keratinocytes were incubated for 6 days with GE. Nile Red labeling revealed that GE significantly increased lipid synthesis in keratinocytes. Similarly, gas chromatography with flame ionization detector indicated that GE increases the amount of triglycerides in keratinocytes. GE induced the expression of epidermal ceramide synthase 3, but not sphingomyelinase. Lipid synthesis, as well as ceramide synthase 3 expression, could be specifically blocked by inhibitors of the p38 MAPK and PPARγ signaling pathway. To assess if GE also modulates lipid synthesis in vivo, we performed a proof of concept half side comparison on the volar forearms of 33 volunteers. In comparison to placebo, GE significantly increased the lipid content of the treated skin areas, as measured with a sebumeter. Thus, GE enhances lipid synthesis in human keratinocytes that is essential for building an intact epidermal barrier. Therefore, GE might be used to improve skin disorders with an impaired epidermal barrier, e.g., very dry skin and atopic eczema.

Noninvasive penetration of 5 nm hyaluronic acid molecules across the epidermal barrier (in vitro) and its interaction with human skin cells.

PubMed

Nashchekina, Yu A; Raydan, M

2018-02-01

Hyaluronic acid represents one of the major components of the extracellular environment. The main challenge remains in the ability to deliver these molecules noninvasively across the skin barrier, which can be overcome by the reduction in size to an extent that allows these molecules to pass across the skin barrier. The aim of this study was to measure the penetration and bioavailability of low molecular weight hyaluronic acid to cross an epidermal barrier model. Determining the quantity of hyaluronic acid in the test solutions was carried with method of photocolorimetry analysis. Investigation of the interaction of cells with LMWHA was studied with a confocal microscope. The study showed that LMWHA is able to cross the epidermis. Most effective penetration level is during the first 6 hours reaching 75%, and then the concentration started to decline and reached the equilibrium state within the following 2 hours. Confocal laser microscopy demonstrated different distribution and behavior of these molecules among the keratinocytes and fibroblasts. Reducing the size of hyaluronic acid to 5 nm enhance their transport across the epidermal layer. The concentration of hyaluronic acid molecules was higher on the fibroblast surface in comparison to their extracellular environment. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Cervi cornus Colla (deer antler glue) induce epidermal differentiation in the reconstruction of skin equivalents.

PubMed

Choi, H-R; Nam, K-M; Kim, D-S; Huh, C-H; Na, J-I; Park, K-C

2013-06-01

In the reconstruction of skin equivalents (SEs), keratinocyte differentiation is important because epidermal differentiation is closely related with barrier function. The aim of this study was to investigate the effects of Cervi cornus Colla (CCC) on the stem cell activity and epidermal differentiation in the reconstruction of skin equivalent. Four different models were constructed according to different composition of dermal substitute. Results showed similar morphologic findings when hyaluronic acid (HA) and/or CCC was added. But, immunohistochemical staining showed that p63 was significantly increased by addition of HA and/or CCC. Increased staining of integrin α6 and β1 was variably observed when HA and/or CCC was added to make dermal substitute. These finding showed that addition of HA and/or CCC may affect the stem cell activity in the reconstruction of skin. Furthermore, filaggrin expression was much increased when CCC was added. It showed that epidermal differentiation was significantly improved by addition of CCC. In conclusion, simultaneous presence of HA and CCC contributed to the stem cell activity and epidermal differentiation in the reconstruction of SE. Legislation in the EU prohibits marketing cosmetics and personal care products that contain constituents that have been examined through animal experiments. To avoid these limitations, SEs can be used for testing the safety or the efficacy of cosmetic ingredients. Therefore, our results showed that combined use of HA and CCC can be helpful for the reconstruction of SE with good stem cell activity and epidermal differentiation. © 2013 Society of Cosmetic Scientists and the Société Française de Cosmétologie.

Early-onset pediatric atopic dermatitis is characterized by TH2/TH17/TH22-centered inflammation and lipid alterations.

PubMed

Brunner, Patrick M; Israel, Ariel; Zhang, Ning; Leonard, Alexandra; Wen, Huei-Chi; Huynh, Thy; Tran, Gary; Lyon, Sarah; Rodriguez, Giselle; Immaneni, Supriya; Wagner, Annette; Zheng, Xiuzhong; Estrada, Yeriel D; Xu, Hui; Krueger, James G; Paller, Amy S; Guttman-Yassky, Emma

2018-06-01

Although atopic dermatitis (AD) often starts in early childhood, detailed tissue profiling of early-onset AD in children is lacking, hindering therapeutic development for this patient population with a particularly high unmet need for better treatments. We sought to globally profile the skin of infants with AD compared with that of adults with AD and healthy control subjects. We performed microarray, RT-PCR, and fluorescence microscopy studies in infants and young children (<5 years old) with early-onset AD (<6 months disease duration) compared with age-matched control subjects and adults with longstanding AD. Transcriptomic analyses revealed profound differences between pediatric patients with early-onset versus adult patients with longstanding AD in not only lesional but also nonlesional tissues. Although both patient populations harbored T H 2-centered inflammation, pediatric AD also showed significant T H 17/T H 22 skewing but lacked the T H 1 upregulation that characterizes adult AD. Pediatric AD exhibited relatively normal expression of epidermal differentiation and cornification products, which is downregulated in adults with AD. Defects in the lipid barrier (eg, ELOVL fatty acid elongase 3 [ELOVL3] and diacylglycerol o-acyltransferase 2 [DGAT2]) and tight junction regulation (eg, claudins 8 and 23) were evident in both groups. However, some lipid-associated mediators (eg, fatty acyl-CoA reductase 2 and fatty acid 2-hydroxylase) showed preferential downregulation in pediatric AD, and lipid barrier genes (FA2H and DGAT2) showed inverse correlations with transepidermal water loss, a functional measure of the epidermal barrier. Skin samples from children and adult patients with AD share lipid metabolism and tight junction alterations, but epidermal differentiation complex defects are only present in adult AD, potentially resulting from chronic immune aberration that is not yet present in early-onset disease. Copyright © 2018 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.

Molecular interactions of plant oil components with stratum corneum lipids correlate with clinical measures of skin barrier function

PubMed Central

Mack Correa, Mary Catherine; Mao, Guangru; Saad, Peter; Flach, Carol R; Mendelsohn, Richard; Walters, Russel M

2014-01-01

Plant-derived oils consisting of triglycerides and small amounts of free fatty acids (FFAs) are commonly used in skincare regimens. FFAs are known to disrupt skin barrier function. The objective of this study was to mechanistically study the effects of FFAs, triglycerides and their mixtures on skin barrier function. The effects of oleic acid (OA), glyceryl trioleate (GT) and OA/GT mixtures on skin barrier were assessed in vivo through measurement of transepidermal water loss (TEWL) and fluorescein dye penetration before and after a single application. OA's effects on stratum corneum (SC) lipid order in vivo were measured with infrared spectroscopy through application of perdeuterated OA (OA-d34). Studies of the interaction of OA and GT with skin lipids included imaging the distribution of OA-d34 and GT ex vivo with IR microspectroscopy and thermodynamic analysis of mixtures in aqueous monolayers. The oil mixtures increased both TEWL and fluorescein penetration 24 h after a single application in an OA dose-dependent manner, with the highest increase from treatment with pure OA. OA-d34 penetrated into skin and disordered SC lipids. Furthermore, the ex vivo IR imaging studies showed that OA-d34 permeated to the dermal/epidermal junction while GT remained in the SC. The monolayer experiments showed preferential interspecies interactions between OA and SC lipids, while the mixing between GT and SC lipids was not thermodynamically preferred. The FFA component of plant oils may disrupt skin barrier function. The affinity between plant oil components and SC lipids likely determines the extent of their penetration and clinically measurable effects on skin barrier functions. PMID:24372651

Molecular Mechanisms of Cutaneous Inflammatory Disorder: Atopic Dermatitis

PubMed Central

Kim, Jung Eun; Kim, Jong Sic; Cho, Dae Ho; Park, Hyun Jeong

2016-01-01

Atopic dermatitis (AD) is a multifactorial inflammatory skin disease resulting from interactions between genetic susceptibility and environmental factors. The pathogenesis of AD is poorly understood, and the treatment of recalcitrant AD is still challenging. There is accumulating evidence for new gene polymorphisms related to the epidermal barrier function and innate and adaptive immunity in patients with AD. Newly-found T cells and dendritic cell subsets, cytokines, chemokines and signaling pathways have extended our understanding of the molecular pathomechanism underlying AD. Genetic changes caused by environmental factors have been shown to contribute to the pathogenesis of AD. We herein present a review of the genetics, epigenetics, barrier dysfunction and immunological abnormalities in AD with a focus on updated molecular biology. PMID:27483258

The expression and regulation of enzymes mediating the biosynthesis of triglycerides and phospholipids in keratinocytes/epidermis

PubMed Central

Feingold, Kenneth R

2011-01-01

Triglycerides and phospholipids play an important role in epidermal permability barrier formation and function. They are synthesized de novo in the epidermis via the glycerol-3-phosphate pathway, catalyzed sequentially by a group of enzymes that have multiple isoforms including glycerol-3-phosphate acyltransferase (GPAT), 1-acylglycerol-3-phosphate acyltransferase (AGPAT), Lipin and diacylglycerol acyltransferase (DGAT). Here we review the current knowledge of GPAT, AGPAT, Lipin and DGAT enzymes in keratinocytes/epidermis focusing on the expression levels of the various isoforms and their localization in mouse epidermis. Additionally, the factors regulating their gene expression, including calcium induced differentiation, PPAR and LXR activators, and the effect of acute permeability barrier disruption will be discussed. PMID:21695015

LIPID ABNORMALITIES AND LIPID-BASED REPAIR STRATEGIES IN ATOPIC DERMATITIS

PubMed Central

Elias, Peter M.

2013-01-01

Prior studies have revealed the key roles played by Th1/Th2 cell dysregulation, IgE production, mast cell hyperactivity, and dendritic cell signaling in the evolution of the chronic, pruritic, inflammatory dermatosis that characterizes atopic dermatitis (AD). We review here increasing evidence that the inflammation in AD results primarily from inherited abnormalities in epidermal structural and enzymatic proteins that impact permeability barrier function. We also will show that the barrier defect can be attributed to a paracellular abnormality due to a variety of abnormalities in lipid composition, transport and extracellular organization. Accordingly, we also review the therapeutic implications of this emerging pathogenic paradigm, including several current and potentially novel, lipid-based approaches to corrective therapy. PMID:24128970

Topical use of dexpanthenol in skin disorders.

PubMed

Ebner, Fritz; Heller, Andreas; Rippke, Frank; Tausch, Irene

2002-01-01

Pantothenic acid is essential to normal epithelial function. It is a component of coenzyme A, which serves as a cofactor for a variety of enzyme-catalyzed reactions that are important in the metabolism of carbohydrates, fatty acids, proteins, gluconeogenesis, sterols, steroid hormones, and porphyrins. The topical use of dexpanthenol, the stable alcoholic analog of pantothenic acid, is based on good skin penetration and high local concentrations of dexpanthenol when administered in an adequate vehicle, such as water-in-oil emulsions. Topical dexpanthenol acts like a moisturizer, improving stratum corneum hydration, reducing transepidermal water loss and maintaining skin softness and elasticity. Activation of fibroblast proliferation, which is of relevance in wound healing, has been observed both in vitro and in vivo with dexpanthenol. Accelerated re-epithelization in wound healing, monitored by means of the transepidermal water loss as an indicator of the intact epidermal barrier function, has also been seen. Dexpanthenol has been shown to have an anti-inflammatory effect on experimental ultraviolet-induced erythema. Beneficial effects of dexpanthenol have been observed in patients who have undergone skin transplantation or scar treatment, or therapy for burn injuries and different dermatoses. The stimulation of epithelization, granulation and mitigation of itching were the most prominent effects of formulations containing dexpanthenol. In double-blind placebo-controlled clinical trials, dexpanthenol was evaluated for its efficacy in improving wound healing. Epidermal wounds treated with dexpanthenol emulsion showed a reduction in erythema, and more elastic and solid tissue regeneration. Monitoring of transepidermal water loss showed a significant acceleration of epidermal regeneration as a result of dexpanthenol therapy, as compared with the vehicle. In an irritation model, pretreatment with dexpanthenol cream resulted in significantly less damage to the stratum corneum barrier, compared with no pretreatment. Adjuvant skin care with dexpanthenol considerably improved the symptoms of skin irritation, such as dryness of the skin, roughness, scaling, pruritus, erythema, erosion/fissures, over 3 to 4 weeks. Usually, the topical administration of dexpanthenol preparations is well tolerated, with minimal risk of skin irritancy or sensitization.

[Prevention and regeneration of barrier disturbances in occupational dermatology].

PubMed

Schürer, Nanna Y; Schwanitz, Hans J

2004-11-01

Over the past 10 years primary, secondary and tertiary prevention of occupational skin disorders has been shown to be successful, documented with appropriate statistical methods. Interventional strategies are the main features of secondary and tertiary prevention, now well-established in occupational dermatology. Primary prevention is best accomplished by health education measures, both in the form on individual counseling and seminars. This overview reviews the scientific background of hand eczema with respect to barrier damage and repair and then considers the options for individualized and focused prevention. Special anatomical features of the interdigital space and palms, as well as functional disorders, such as palmar hyperhidrosis, are discussed. The importance of barrier regeneration is considered in light of the role of an acid pH, the epidermal calcium gradient and aspects of percutaneous absorption. The effects of anti-oxidants are considered, and new bioengineering methods which rely on physiologic measuring techniques are reviewed.

Skin integrated with perfusable vascular channels on a chip.

PubMed

Mori, Nobuhito; Morimoto, Yuya; Takeuchi, Shoji

2017-02-01

This paper describes a method for fabricating perfusable vascular channels coated with endothelial cells within a cultured skin-equivalent by fixing it to a culture device connected to an external pump and tubes. A histological analysis showed that vascular channels were constructed in the skin-equivalent, which showed a conventional dermal/epidermal morphology, and the endothelial cells formed tight junctions on the vascular channel wall. The barrier function of the skin-equivalent was also confirmed. Cell distribution analysis indicated that the vascular channels supplied nutrition to the skin-equivalent. Moreover, the feasibility of a skin-equivalent containing vascular channels as a model for studying vascular absorption was demonstrated by measuring test molecule permeation from the epidermal layer into the vascular channels. The results suggested that this skin-equivalent can be used for skin-on-a-chip applications including drug development, cosmetics testing, and studying skin biology. Copyright © 2016 Elsevier Ltd. All rights reserved.

A novel DLX3-PKC integrated signaling network drives keratinocyte differentiation.

PubMed

Palazzo, Elisabetta; Kellett, Meghan D; Cataisson, Christophe; Bible, Paul W; Bhattacharya, Shreya; Sun, Hong-Wei; Gormley, Anna C; Yuspa, Stuart H; Morasso, Maria I

2017-04-01

Epidermal homeostasis relies on a well-defined transcriptional control of keratinocyte proliferation and differentiation, which is critical to prevent skin diseases such as atopic dermatitis, psoriasis or cancer. We have recently shown that the homeobox transcription factor DLX3 and the tumor suppressor p53 co-regulate cell cycle-related signaling and that this mechanism is functionally involved in cutaneous squamous cell carcinoma development. Here we show that DLX3 expression and its downstream signaling depend on protein kinase C α (PKCα) activity in skin. We found that following 12-O-tetradecanoyl-phorbol-13-acetate (TPA) topical treatment, DLX3 expression is significantly upregulated in the epidermis and keratinocytes from mice overexpressing PKCα by transgenic targeting (K5-PKCα), resulting in cell cycle block and terminal differentiation. Epidermis lacking DLX3 (DLX3cKO), which is linked to the development of a DLX3-dependent epidermal hyperplasia with hyperkeratosis and dermal leukocyte recruitment, displays enhanced PKCα activation, suggesting a feedback regulation of DLX3 and PKCα. Of particular significance, transcriptional activation of epidermal barrier, antimicrobial peptide and cytokine genes is significantly increased in DLX3cKO skin and further increased by TPA-dependent PKC activation. Furthermore, when inhibiting PKC activity, we show that epidermal thickness, keratinocyte proliferation and inflammatory cell infiltration are reduced and the PKC-DLX3-dependent gene expression signature is normalized. Independently of PKC, DLX3 expression specifically modulates regulatory networks such as Wnt signaling, phosphatase activity and cell adhesion. Chromatin immunoprecipitation sequencing analysis of primary suprabasal keratinocytes showed binding of DLX3 to the proximal promoter regions of genes associated with cell cycle regulation, and of structural proteins and transcription factors involved in epidermal differentiation. These results indicate that Dlx3 potentially regulates a set of crucial genes necessary during the epidermal differentiation process. Altogether, we demonstrate the existence of a robust DLX3-PKCα signaling pathway in keratinocytes that is crucial to epidermal differentiation control and cutaneous homeostasis.

A novel DLX3–PKC integrated signaling network drives keratinocyte differentiation

PubMed Central

Palazzo, Elisabetta; Kellett, Meghan D; Cataisson, Christophe; Bible, Paul W; Bhattacharya, Shreya; Sun, Hong-wei; Gormley, Anna C; Yuspa, Stuart H; Morasso, Maria I

2017-01-01

Epidermal homeostasis relies on a well-defined transcriptional control of keratinocyte proliferation and differentiation, which is critical to prevent skin diseases such as atopic dermatitis, psoriasis or cancer. We have recently shown that the homeobox transcription factor DLX3 and the tumor suppressor p53 co-regulate cell cycle-related signaling and that this mechanism is functionally involved in cutaneous squamous cell carcinoma development. Here we show that DLX3 expression and its downstream signaling depend on protein kinase C α (PKCα) activity in skin. We found that following 12-O-tetradecanoyl-phorbol-13-acetate (TPA) topical treatment, DLX3 expression is significantly upregulated in the epidermis and keratinocytes from mice overexpressing PKCα by transgenic targeting (K5-PKCα), resulting in cell cycle block and terminal differentiation. Epidermis lacking DLX3 (DLX3cKO), which is linked to the development of a DLX3-dependent epidermal hyperplasia with hyperkeratosis and dermal leukocyte recruitment, displays enhanced PKCα activation, suggesting a feedback regulation of DLX3 and PKCα. Of particular significance, transcriptional activation of epidermal barrier, antimicrobial peptide and cytokine genes is significantly increased in DLX3cKO skin and further increased by TPA-dependent PKC activation. Furthermore, when inhibiting PKC activity, we show that epidermal thickness, keratinocyte proliferation and inflammatory cell infiltration are reduced and the PKC-DLX3-dependent gene expression signature is normalized. Independently of PKC, DLX3 expression specifically modulates regulatory networks such as Wnt signaling, phosphatase activity and cell adhesion. Chromatin immunoprecipitation sequencing analysis of primary suprabasal keratinocytes showed binding of DLX3 to the proximal promoter regions of genes associated with cell cycle regulation, and of structural proteins and transcription factors involved in epidermal differentiation. These results indicate that Dlx3 potentially regulates a set of crucial genes necessary during the epidermal differentiation process. Altogether, we demonstrate the existence of a robust DLX3–PKCα signaling pathway in keratinocytes that is crucial to epidermal differentiation control and cutaneous homeostasis. PMID:28186503

Barrier Function of the Repaired Skin Is Disrupted Following Arrest of Dicer in Keratinocytes

PubMed Central

Ghatak, Subhadip; Chan, Yuk Cheung; Khanna, Savita; Banerjee, Jaideep; Weist, Jessica; Roy, Sashwati; Sen, Chandan K

2015-01-01

Tissue injury transiently silences miRNA-dependent posttranscriptional gene silencing in its effort to unleash adult tissue repair. Once the wound is closed, miRNA biogenesis is induced averting neoplasia. In this work, we report that Dicer plays an important role in reestablishing the barrier function of the skin post-wounding via a miRNA-dependent mechanism. MicroRNA expression profiling of skin and wound-edge tissue revealed global upregulation of miRNAs following wound closure at day 14 post-wounding with significant induction of Dicer expression. Barrier function of the skin, as measured by trans-epidermal water loss, was compromised in keratinocyte-specific conditional (K14/Lox-Cre) Dicer-ablated mice because of malformed cornified epithelium lacking loricrin expression. Studies on human keratinocytes recognized that loricrin expression was inversely related to the expression of the cyclin-dependent kinase inhibitor p21Waf1/Cip1. Compared to healthy epidermis, wound-edge keratinocytes from Dicer-ablated skin epidermis revealed elevated p21Waf1/Cip1 expression. Adenoviral and pharmacological suppression of p21Waf1/Cip1 in keratinocyte-specific conditional Dicer-ablated mice improved wound healing indicating a role of Dicer in the suppression of p21Waf1/Cip1. This work upholds p21Waf1/Cip1 as a druggable target to restore barrier function of skin suffering from loss of Dicer function as would be expected in diabetes and other forms of oxidant insult. PMID:25896246

Long-range comparison of human and mouse Sprr loci to identify conserved noncoding sequences involved in coordinate regulation

PubMed Central

Martin, Natalia; Patel, Satyakam; Segre, Julia A.

2004-01-01

Mammalian epidermis provides a permeability barrier between an organism and its environment. Under homeostatic conditions, epidermal cells produce structural proteins, which are cross-linked in an orderly fashion to form a cornified envelope (CE). However, under genetic or environmental stress, specific genes are induced to rapidly build a temporary barrier. Small proline-rich (SPRR) proteins are the primary constituents of the CE. Under stress the entire family of 14 Sprr genes is upregulated. The Sprr genes are clustered within the larger epidermal differentiation complex on mouse chromosome 3, human chromosome 1q21. The clustering of the Sprr genes and their upregulation under stress suggest that these genes may be coordinately regulated. To identify enhancer elements that regulate this stress response activation of the Sprr locus, we utilized bioinformatic tools and classical biochemical dissection. Long-range comparative sequence analysis identified conserved noncoding sequences (CNSs). Clusters of epidermal-specific DNaseI-hypersensitive sites (HSs) mapped to specific CNSs. Increased prevalence of these HSs in barrier-deficient epidermis provides in vivo evidence of the regulation of the Sprr locus by these conserved sequences. Individual components of these HSs were cloned, and one was shown to have strong enhancer activity specific to conditions when the Sprr genes are coordinately upregulated. PMID:15574822

Effects of Hydroxydecine(®) (10-hydroxy-2-decenoic acid) on skin barrier structure and function in vitro and clinical efficacy in the treatment of UV-induced xerosis.

PubMed

Duplan, Hélène; Questel, Emmanuel; Hernandez-Pigeon, Hélène; Galliano, Marie Florence; Caruana, Antony; Ceruti, Isabelle; Ambonati, Marco; Mejean, Carine; Damour, Odile; Castex-Rizzi, Nathalie; Bessou-Touya, Sandrine; Schmitt, Anne-Marie

2011-01-01

10-Hydroxy-2-decenoic acid, a natural fatty acid only found in royal jelly, may be of value in correcting skin barrier dysfunction. We evaluated the activity of Hydroxydecine(®), its synthetic counterpart, in vitro on the regulation of epidermal differentiation markers, ex vivo on the inflammatory response and restoration of skin barrier function, and in vivo on UV-induced xerosis in healthy human volunteers. In cultured normal human keratinocytes, Hydroxydecine(®) induced involucrin, transglutaminase-1 and filaggrin protein production. In topically Hydroxydecine(®)-treated skin equivalents, immunohistochemical analysis revealed an increase in involucrin, transglutaminase-1 and filaggrin staining. In a model of thymic stromal lymphopoietin (TSLP)-induced inflamed epidermis, a Hydroxydecine(®)-containing emulsion inhibited TSLP release. In a model of inflammation and barrier impairment involving human skin explants maintained alive, Hydroxydecine(®) balm restored stratum corneum cohesion and significantly increased filaggrin expression, as shown by immunohistochemistry. It also decreased pro-inflammatory cytokine secretion (IL-4, IL-5 and IL-13). In healthy volunteers with UV-induced xerosis, the hydration index increased by +28.8% (p<0.01) and +60.4% (p<0.001) after 7 and 21 days of treatment with Hydroxydecine(®) cream, respectively. Hydroxydecine(®) thus proved its efficacy in activating keratinocyte differentiation processes in vitro, restoring skin barrier function and reducing inflammation ex vivo, and hydrating dry skin in vivo.

The atypical mitogen-activated protein kinase ERK3 is essential for establishment of epithelial architecture.

PubMed

Takahashi, Chika; Miyatake, Koichi; Kusakabe, Morioh; Nishida, Eisuke

2018-06-01

Epithelia contribute to physical barriers that protect internal tissues from the external environment and also support organ structure. Accordingly, establishment and maintenance of epithelial architecture are essential for both embryonic development and adult physiology. Here, using gene knockout and knockdown techniques along with gene profiling, we show that extracellular signal-regulated kinase 3 (ERK3), a poorly characterized atypical mitogen-activated protein kinase (MAPK), regulates the epithelial architecture in vertebrates. We found that in Xenopus embryonic epidermal epithelia, ERK3 knockdown impairs adherens and tight-junction protein distribution, as well as tight-junction barrier function, resulting in epidermal breakdown. Moreover, in human epithelial breast cancer cells, inhibition of ERK3 expression induced thickened epithelia with aberrant adherens and tight junctions. Results from microarray analyses suggested that transcription factor AP-2α (TFAP2A), a transcriptional regulator important for epithelial gene expression, is involved in ERK3-dependent changes in gene expression. Of note, TFAP2A knockdown phenocopied ERK3 knockdown in both Xenopus embryos and human cells, and ERK3 was required for full activation of TFAP2A-dependent transcription. Our findings reveal that ERK3 regulates epithelial architecture, possibly together with TFAP2A. © 2018 by The American Society for Biochemistry and Molecular Biology, Inc.

Longitudinal Evaluation of the Skin Microbiome and Association with Microenvironment and Treatment in Canine Atopic Dermatitis.

PubMed

Bradley, Charles W; Morris, Daniel O; Rankin, Shelley C; Cain, Christine L; Misic, Ana M; Houser, Timothy; Mauldin, Elizabeth A; Grice, Elizabeth A

2016-06-01

Host-microbe interactions may play a fundamental role in the pathogenesis of atopic dermatitis, a chronic relapsing inflammatory skin disorder characterized by universal colonization with Staphylococcus species. To examine the relationship between epidermal barrier function and the cutaneous microbiota in atopic dermatitis, this study used a spontaneous model of canine atopic dermatitis. In a cohort of 14 dogs with canine atopic dermatitis, the skin microbiota were longitudinally evaluated with parallel assessment of skin barrier function at disease flare, during antimicrobial therapy, and post-therapy. Sequencing of the bacterial 16S ribosomal RNA gene showed decreased bacterial diversity and increased proportions of Staphylococcus (S. pseudintermedius in particular) and Corynebacterium species compared with a cohort of healthy control dogs (n = 16). Treatment restored bacterial diversity with decreased proportions of Staphylococcus species, concurrent with decreased canine atopic dermatitis severity. Skin barrier function, as measured by corneometry, pH, and transepidermal water loss also normalized with treatment. Bacterial diversity correlated with transepidermal water loss and pH level but not with corneometry results. These findings provide insights into the relationship between the cutaneous microbiome and skin barrier function in atopic dermatitis, show the impact of antimicrobial therapy on the skin microbiome, and highlight the utility of canine atopic dermatitis as a spontaneous nonrodent model of atopic dermatitis. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Proteins and Carbohydrates from Red Seaweeds: Evidence for Beneficial Effects on Gut Function and Microbiota

PubMed Central

Cian, Raúl E.; Drago, Silvina R.; Sánchez de Medina, Fermín; Martínez-Augustin, Olga

2015-01-01

Based on their composition, marine algae, and namely red seaweeds, are good potential functional foods. Intestinal mucosal barrier function refers to the capacity of the intestine to provide adequate containment of luminal microorganisms and molecules. Here, we will first outline the component of seaweeds and will summarize the effects of these on the regulation of mucosal barrier function. Special attention will be paid to unique components of red seaweeds: proteins and derived peptides (e.g., phycobiliproteins, glycoproteins that contain “cellulose binding domains”, phycolectins and the related mycosporine-like amino acids) together with polysaccharides (e.g., floridean starch and sulfated galactans, such as carrageenans, agarans and “dl-hybrid”) and minerals. These compounds have been shown to exert prebiotic effects, to regulate intestinal epithelial cell, macrophage and lymphocyte proliferation and differentiation and to modulate the immune response. Molecular mechanisms of action of peptides and polysaccharides are starting to be elucidated, and evidence indicating the involvement of epidermal growth factor receptor (EGFR), insulin-like growth factor receptor (IGFR), Toll-like receptors (TLR) and signal transduction pathways mediated by protein kinase B (PKB or AKT), nuclear factor-κB (NF-κB) and mitogen activated protein kinases (MAPK) will also be summarized. The need for further research is clear, but in vivo experiments point to an overall antiinflammatory effect of these algae, indicating that they can reinforce membrane barrier function. PMID:26308006

Proteins and Carbohydrates from Red Seaweeds: Evidence for Beneficial Effects on Gut Function and Microbiota.

PubMed

Cian, Raúl E; Drago, Silvina R; de Medina, Fermín Sánchez; Martínez-Augustin, Olga

2015-08-20

Based on their composition, marine algae, and namely red seaweeds, are good potential functional foods. Intestinal mucosal barrier function refers to the capacity of the intestine to provide adequate containment of luminal microorganisms and molecules. Here, we will first outline the component of seaweeds and will summarize the effects of these on the regulation of mucosal barrier function. Special attention will be paid to unique components of red seaweeds: proteins and derived peptides (e.g., phycobiliproteins, glycoproteins that contain "cellulose binding domains", phycolectins and the related mycosporine-like amino acids) together with polysaccharides (e.g., floridean starch and sulfated galactans, such as carrageenans, agarans and "dl-hybrid") and minerals. These compounds have been shown to exert prebiotic effects, to regulate intestinal epithelial cell, macrophage and lymphocyte proliferation and differentiation and to modulate the immune response. Molecular mechanisms of action of peptides and polysaccharides are starting to be elucidated, and evidence indicating the involvement of epidermal growth factor receptor (EGFR), insulin-like growth factor receptor (IGFR), Toll-like receptors (TLR) and signal transduction pathways mediated by protein kinase B (PKB or AKT), nuclear factor-κB (NF-κB) and mitogen activated protein kinases (MAPK) will also be summarized. The need for further research is clear, but in vivo experiments point to an overall antiinflammatory effect of these algae, indicating that they can reinforce membrane barrier function.

Dietary Milk Sphingomyelin Prevents Disruption of Skin Barrier Function in Hairless Mice after UV-B Irradiation.

PubMed

Oba, Chisato; Morifuji, Masashi; Ichikawa, Satomi; Ito, Kyoko; Kawahata, Keiko; Yamaji, Taketo; Asami, Yukio; Itou, Hiroyuki; Sugawara, Tatsuya

2015-01-01

Exposure to ultraviolet-B (UV-B) irradiation causes skin barrier defects. Based on earlier findings that milk phospholipids containing high amounts of sphingomyelin (SM) improved the water content of the stratum corneum (SC) in normal mice, here we investigated the effects of dietary milk SM on skin barrier defects induced by a single dose of UV-B irradiation in hairless mice. Nine week old hairless mice were orally administrated SM (146 mg/kg BW/day) for a total of ten days. After seven days of SM administration, the dorsal skin was exposed to a single dose of UV-B (20 mJ/cm2). Administration of SM significantly suppressed an increase in transepidermal water loss and a decrease in SC water content induced by UV-B irradiation. SM supplementation significantly maintained covalently-bound ω-hydroxy ceramide levels and down-regulated mRNA levels of acute inflammation-associated genes, including thymic stromal lymphopoietin, interleukin-1 beta, and interleukin-6. Furthermore, significantly higher levels of loricrin and transglutaminase-3 mRNA were observed in the SM group. Our study shows for the first time that dietary SM modulates epidermal structures, and can help prevent disruption of skin barrier function after UV-B irradiation.

Comparative effect of gromwell (Lithospermum erythrorhizon) extract and borage oil on reversing epidermal hyperproliferation in guinea pigs.

PubMed

Kim, Juyoung; Kim, Hyunae; Jeong, Do Hyeon; Kim, Sung Han; Park, Seong Kyu; Cho, Yunhi

2006-09-01

To compare the systemic efficacy of borage oil (Borago officinalis: BO) and gromwell (Lithospermum erythrorhizon), two plant species of the Boraginaceae family, epidermal hyperproliferation was induced in guinea pigs by a hydrogenated coconut oil diet for 8 weeks. Subsequently, guinea pigs were fed diets of BO (group HBO), organic extract (group HGO), or water extract (group HGW) of gromwell for 2 weeks. In groups HGO and HGW, proliferation scores and the level of ceramides, the major lipid maintaining epidermal barrier, were similar with those in normal control group BO fed BO diet for 10 weeks. Despite accumulation of 15-hydroxyeicosatrienoic acid (15-HETrE), the potent anti-proliferative metabolite of gamma-linolenic acid (GLA: major polyunsaturated fatty acid in BO), the reversal of epidermal hyperproliferation and the ceramide level of group HBO were less than those of groups HGO and HGW. Taken together, our data demonstrate that gromwell is more effective in reversing epidermal hyperproliferation with a marked increase in ceramides.

The Roles of Vitamin C in Skin Health.

PubMed

Pullar, Juliet M; Carr, Anitra C; Vissers, Margreet C M

2017-08-12

The primary function of the skin is to act as a barrier against insults from the environment, and its unique structure reflects this. The skin is composed of two layers: the epidermal outer layer is highly cellular and provides the barrier function, and the inner dermal layer ensures strength and elasticity and gives nutritional support to the epidermis. Normal skin contains high concentrations of vitamin C, which supports important and well-known functions, stimulating collagen synthesis and assisting in antioxidant protection against UV-induced photodamage. This knowledge is often used as a rationale for the addition of vitamin C to topical applications, but the efficacy of such treatment, as opposed to optimising dietary vitamin C intake, is poorly understood. This review discusses the potential roles for vitamin C in skin health and summarises the in vitro and in vivo research to date. We compare the efficacy of nutritional intake of vitamin C versus topical application, identify the areas where lack of evidence limits our understanding of the potential benefits of vitamin C on skin health, and suggest which skin properties are most likely to benefit from improved nutritional vitamin C intake.

Biochemistry of epidermal stem cells.

PubMed

Eckert, Richard L; Adhikary, Gautam; Balasubramanian, Sivaprakasam; Rorke, Ellen A; Vemuri, Mohan C; Boucher, Shayne E; Bickenbach, Jackie R; Kerr, Candace

2013-02-01

The epidermis is an important protective barrier that is essential for maintenance of life. Maintaining this barrier requires continuous cell proliferation and differentiation. Moreover, these processes must be balanced to produce a normal epidermis. The stem cells of the epidermis reside in specific locations in the basal epidermis, hair follicle and sebaceous glands and these cells are responsible for replenishment of this tissue. A great deal of effort has gone into identifying protein epitopes that mark stem cells, in identifying stem cell niche locations, and in understanding how stem cell populations are related. We discuss these studies as they apply to understanding normal epidermal homeostasis and skin cancer. An assortment of stem cell markers have been identified that permit assignment of stem cells to specific regions of the epidermis, and progress has been made in understanding the role of these cells in normal epidermal homeostasis and in conditions of tissue stress. A key finding is the multiple stem cell populations exist in epidermis that give rise to different structures, and that multiple stem cell types may contribute to repair in damaged epidermis. Understanding epidermal stem cell biology is likely to lead to important therapies for treating skin diseases and cancer, and will also contribute to our understanding of stem cells in other systems. This article is part of a Special Issue entitled Biochemistry of Stem Cells. Copyright © 2012 Elsevier B.V. All rights reserved.

Biochemistry of epidermal stem cells☆

PubMed Central

Eckert, Richard L.; Adhikary, Gautam; Balasubramanian, Sivaprakasam; Rorke, Ellen A.; Vemuri, Mohan C.; Boucher, Shayne E.; Bickenbach, Jackie R.; Kerr, Candace

2014-01-01

Background The epidermis is an important protective barrier that is essential for maintenance of life. Maintaining this barrier requires continuous cell proliferation and differentiation. Moreover, these processes must be balanced to produce a normal epidermis. The stem cells of the epidermis reside in specific locations in the basal epidermis, hair follicle and sebaceous glands and these cells are responsible for replenishment of this tissue. Scope of review A great deal of effort has gone into identifying protein epitopes that mark stem cells, in identifying stem cell niche locations, and in understanding how stem cell populations are related. We discuss these studies as they apply to understanding normal epidermal homeostasis and skin cancer. Major conclusions An assortment of stem cell markers have been identified that permit assignment of stem cells to specific regions of the epidermis, and progress has been made in understanding the role of these cells in normal epidermal homeostasis and in conditions of tissue stress. A key finding is the multiple stem cell populations exist in epidermis that give rise to different structures, and that multiple stem cell types may contribute to repair in damaged epidermis. General significance Understanding epidermal stem cell biology is likely to lead to important therapies for treating skin diseases and cancer, and will also contribute to our understanding of stem cells in other systems. This article is part of a Special Issue entitled Biochemistry of Stem Cells. PMID:22820019

Characterization of keratinocyte differentiation induced by ascorbic acid: protein kinase C involvement and vitamin C homeostasis.

PubMed

Savini, Isabella; Catani, Maria Valeria; Rossi, Antonello; Duranti, Guglielmo; Melino, Gerry; Avigliano, Luciana

2002-02-01

Epidermal keratinocytes undergo differentiation in response to several stimuli to form the cornified envelope, a structure that contributes to the barrier function of skin. Although differentiation has been extensively analyzed, the precise role of vitamin C during this process is still not defined. Ascorbic acid, besides acting as a radical scavenger, has been shown to promote mesenchymal differentiation. In this study, we found that keratinocytes grown in ascorbate-supplemented medium developed a differentiated phenotype, as demonstrated by enhanced expression of marker genes and increase in cornified envelope content. The pro-differentiating effects of ascorbate were mediated by the protein-kinase-C-dependent induction of activating protein 1 DNA binding activity; indeed, down-modulation of protein kinase C activity abolished differentiation triggered by ascorbic acid. Although vitamin C appeared to regulate the same signaling pathway modulated by calcium, a classical in vitro inducer of epidermal differentiation, nonetheless terminally differentiated keratinocytes exhibited different ascorbate homeostasis and cellular antioxidant status. Indeed, we found that, unlike calcium, differentiation promoted by ascorbate was accompanied by (i) an enhanced ascorbate transport, due to overexpression of specific transporters, (ii) a great efficiency of dehydroascorbate uptake, and (iii) an increase in glutathione content with respect to proliferating cells. Ascorbic acid may be useful to promote epidermal differentiation, avoiding depletion of hydrophilic antioxidant stores.

Effects of Asterias amurensis-derived Sphingoid Bases on the de novo Ceramide Synthesis in Cultured Normal Human Epidermal Keratinocytes.

PubMed

Mikami, Daisuke; Sakai, Shota; Sasaki, Shigefumi; Igarashi, Yasuyuki

2016-08-01

Asterias amurensis starfish provide several bioactive species in addition to being fishery waste. Glucosyl ceramides (GlcCers) were extracted from the viscera of these starfish and were isolated by silica gel column chromatography. Degraded GlcCers generated A. amurensis sphingoid bases (ASBs) that mainly consisted of the triene-type bases d18:3 and 9-methyl-d18:3. The effect of these bases on ceramide synthesis and content were analyzed using normal human epidermal keratinocytes (NHEKs). The bases significantly enhanced the de novo ceramide synthesis and gene expression in NHEKs for proteins, such as serine-palmitoyltransferase and ceramide synthase. Total ceramide, GlcCer, and sphingomyelin contents increased dramatically upon ASB treatment. In particular, GlcCer bearing very-long-chain fatty acids (≥C28) exhibited a significant content increase. These ASB-induced enhancements on de novo ceramide synthesis were only observed in undifferentiated NHEKs. This stimulation of the de novo sphingolipid synthesis may improve skin barrier functions.

Evaluation of a human bio-engineered skin equivalent for drug permeation studies.

PubMed

Asbill, C; Kim, N; El-Kattan, A; Creek, K; Wertz, P; Michniak, B

2000-09-01

To test the barrier function of a bio-engineered human skin (BHS) using three model drugs (caffeine, hydrocortisone, and tamoxifen) in vitro. To investigate the lipid composition and microscopic structure of the BHS. The human skin substitute was composed of both epidermal and dermal layers, the latter having a bovine collagen matrix. The permeability of the BHS to three model drugs was compared to that obtained in other percutaneous testing models (human cadaver skin, hairless mouse skin, and EpiDerm). Lipid analysis of the BHS was performed by high performance thin layered chromatography. Histological evaluation of the BHS was performed using routine H&E staining. The BHS mimicked human skin in terms of lipid composition, gross ultrastructure, and the formation of a stratum corneum. However, the permeability of the BHS to caffeine, hydrocortisone, and tamoxifen was 3-4 fold higher than that of human cadaver skin. In summary, the results indicate that the BHS may be an acceptable in vitro model for drug permeability testing.

Atopic eczema and the filaggrin story.

PubMed

Brown, Sara J; Irvine, Alan D

2008-06-01

The discovery that null mutations in the filaggrin gene (FLG) are associated with atopic eczema represents the single most significant breakthrough in understanding the genetic basis of this complex disorder. The association has been replicated in multiple independent studies during the past 2 years with the use of various methodologies, from populations in Europe, the United States, and Japan. Filaggrin plays a key role in epidermal barrier function, and its association with atopic eczema emphasizes the importance of barrier dysfunction in eczema pathogenesis. This review aims to summarize the current state of knowledge regarding the role of FLG mutations in ichthyosis vulgaris, atopic eczema, and other skin disorders, with an emphasis on potential clinical applications. Further research is needed to clarify the precise role of filaggrin in skin and systemic atopic disease, to pave the way for novel therapeutic interventions.

The targeted overexpression of a Claudin mutant in the epidermis of transgenic mice elicits striking epidermal and hair follicle abnormalities.

PubMed

Troy, Tammy-Claire; Turksen, Kursad

2007-06-01

Skin is one of the largest organs of the body, and is formed during development through a highly orchestrated process involving mesenchymal-epithelial interactions, cell commitment, and terminal differentiation. It protects against microorganism invasion and UV irradiation, inhibits water loss, regulates body temperature, and is an important part of the immune system. Using transgenic mouse technology, we have demonstrated that Claudin (Cldn)-containing tight junctions (TJs) are intricately involved in cell signaling during epidermal differentiation and that an epidermal suprabasal overexpression of Cldn6 results in a perturbed epidermal terminal differentiation program with distinct phenotypic abnormalities. To delineate the role of the Cldn cytoplasmic tail domain in epidermal differentiation, we engineered transgenic mice targeting the overexpression of a Cldn6 cytoplasmic tail-truncation mutant in the epidermis. Transgenic mice were characterized by a lethal barrier dysfunction in addition to the existence of hyperproliferative squamous invaginations/cysts replacing hair follicles. Immunohistochemical analysis revealed an epidermal cytoplasmic accumulation of Cldn6, Cldn11, Cldn12, and Cldn18, downregulation of Cldn1 and aberrant expression of various classical markers of epidermal differentiation; namely the basal keratins as well as K1, involucrin, loricrin, and filaggrin. Collectively these studies suggest an important role for Cldns in epidermal/hair follicle differentiation programs likely involving cross talk to signaling pathways (e.g., Notch) directing cell fate selection and differentiation.

Atopic dermatitis.

PubMed

Weidinger, Stephan; Novak, Natalija

2016-03-12

Atopic dermatitis (also known as atopic eczema) is a chronic inflammatory skin disease that is characterised by intense itching and recurrent eczematous lesions. Although it most often starts in infancy and affects two of ten children, it is also highly prevalent in adults. It is the leading non-fatal health burden attributable to skin diseases, inflicts a substantial psychosocial burden on patients and their relatives, and increases the risk of food allergy, asthma, allergic rhinitis, other immune-mediated inflammatory diseases, and mental health disorders. Originally regarded as a childhood disorder mediated by an imbalance towards a T-helper-2 response and exaggerated IgE responses to allergens, it is now recognised as a lifelong disposition with variable clinical manifestations and expressivity, in which defects of the epidermal barrier are central. Present prevention and treatment focus on restoration of epidermal barrier function, which is best achieved through the use of emollients. Topical corticosteroids are still the first-line therapy for acute flares, but they are also used proactively along with topical calcineurin inhibitors to maintain remission. Non-specific immunosuppressive drugs are used in severe refractory cases, but targeted disease-modifying drugs are being developed. We need to improve understanding of the heterogeneity of the disease and its subtypes, the role of atopy and autoimmunity, the mechanisms behind disease-associated itch, and the comparative effectiveness and safety of therapies. Copyright © 2016 Elsevier Ltd. All rights reserved.

Application of protease technology in dermatology: rationale for incorporation into skin care with initial observations on formulations designed for skin cleansing, maintenance of hydration, and restoration of the epidermal permeability barrier.

PubMed

Del Rosso, James Q

2013-06-01

This article reviews background on proteases and their functions, their physiological significance in skin, and the potential implications of incorporating specific proteases and protease blends into dermatological products, including skin care formulations. The history of protease blend formulations used in wound model studies and for other disorders is reviewed. In vitro data with use of a specific 3-protease blend with evaluation of the impact on various skin proteins and peptides is also discussed in this article.

Terminal epidermal differentiation is regulated by the interaction of Fra-2/AP-1 with Ezh2 and ERK1/2

PubMed Central

Wurm, Stefanie; Zhang, Jisheng; Guinea-Viniegra, Juan; García, Fernando; Muñoz, Javier; Bakiri, Latifa; Ezhkova, Elena

2015-01-01

Altered epidermal differentiation characterizes numerous skin diseases affecting >25% of the human population. Here we identified Fra-2/AP-1 as a key regulator of terminal epidermal differentiation. Epithelial-restricted, ectopic expression of Fra-2 induced expression of epidermal differentiation genes located within the epidermal differentiation complex (EDC). Moreover, in a papilloma-prone background, a reduced tumor burden was observed due to precocious keratinocyte differentiation by Fra-2 expression. Importantly, loss of Fra-2 in suprabasal keratinocytes is sufficient to cause skin barrier defects due to reduced expression of differentiation genes. Mechanistically, Fra-2 binds and transcriptionally regulates EDC gene promoters, which are co-occupied by the transcriptional repressor Ezh2. Fra-2 remains transcriptionally inactive in nondifferentiated keratinocytes, where it was found monomethylated and dimethylated on Lys104 and interacted with Ezh2. Upon keratinocyte differentiation, Fra-2 is C-terminally phosphorylated on Ser320 and Thr322 by ERK1/2, leading to transcriptional activation. Thus, the induction of epidermal differentiation by Fra-2 is controlled by a dual mechanism involving Ezh2-dependent methylation and activation by ERK1/2-dependent phosphorylation. PMID:25547114

Infrared and Raman spectroscopic features of plant cuticles: a review

PubMed Central

Heredia-Guerrero, José A.; Benítez, José J.; Domínguez, Eva; Bayer, Ilker S.; Cingolani, Roberto; Athanassiou, Athanassia; Heredia, Antonio

2014-01-01

The cuticle is one of the most important plant barriers. It is an external and continuous lipid membrane that covers the surface of epidermal cells and whose main function is to prevent the massive loss of water. The spectroscopic characterization of the plant cuticle and its components (cutin, cutan, waxes, polysaccharides and phenolics) by infrared and Raman spectroscopies has provided significant advances in the knowledge of the functional groups present in the cuticular matrix and on their structural role, interaction and macromolecular arrangement. Additionally, these spectroscopies have been used in the study of cuticle interaction with exogenous molecules, degradation, distribution of components within the cuticle matrix, changes during growth and development and characterization of fossil plants. PMID:25009549

Chimeric Human Skin Substitute Tissue: A Novel Treatment Option for the Delivery of Autologous Keratinocytes.

PubMed

Rasmussen, Cathy A; Allen-Hoffmann, B Lynn

2012-04-01

For patients suffering from catastrophic burns, few treatment options are available. Chimeric coculture of patient-derived autologous cells with a "carrier" cell source of allogeneic keratinocytes has been proposed as a means to address the complex clinical problem of severe skin loss. Currently, autologous keratinocytes are harvested, cultured, and expanded to form graftable epidermal sheets. However, epidermal sheets are thin, are extremely fragile, and do not possess barrier function, which only develops as skin stratifies and matures. Grafting is typically delayed for up to 4 weeks to propagate a sufficient quantity of the patient's cells for application to wound sites. Fully stratified chimeric bioengineered skin substitutes could not only provide immediate wound coverage and restore barrier function, but would simultaneously deliver autologous keratinocytes to wounds. The ideal allogeneic cell source for this application would be an abundant supply of clinically evaluated, nontumorigenic, pathogen-free, human keratinocytes. To evaluate this potential cell-based therapy, mixed populations of a green fluorescent protein-labeled neonatal human keratinocyte cell line (NIKS) and unlabeled primary keratinocytes were used to model the allogeneic and autologous components of chimeric monolayer and organotypic cultures. Relatively few autologous keratinocytes may be required to produce fully stratified chimeric skin substitute tissue substantially composed of autologous keratinocyte-derived regions. The need for few autologous cells interspersed within an allogeneic "carrier" cell population may decrease cell expansion time, reducing the time to patient application. This study provides proof of concept for utilizing NIKS keratinocytes as the allogeneic carrier for the generation of bioengineered chimeric skin substitute tissues capable of providing immediate wound coverage while simultaneously supplying autologous human cells for tissue regeneration.

The temporal and spatial expression of Claudins in epidermal development and the accelerated program of epidermal differentiation in K14-CaSR transgenic mice.

PubMed

Troy, Tammy-Claire; Li, Yuhua; O'Malley, Lauren; Turksen, Kursad

2007-02-01

The importance of the epidermal permeability barrier (EPB) in protecting the mammalian species against harmful UV irradiation, microorganism invasion and water loss is well recognized, as is the role of calcium (Ca(2+)) in keratinocyte differentiation, cell-cell contact and the EPB. In a previous study, we reported that the overexpression of the Ca(2+)-sensing receptor (CaSR) in the undifferentiated basal cells of the epidermis induced a modified epidermal differentiation program including an accelerated EPB formation in transgenic mice, suggesting a role for CaSR signaling in the differentiation of embryonic epidermal cells during development. We now describe the expression profile of claudins (Cldns) and keratin markers in the accelerated EPB formation of K14-CaSR transgenic mice during development as compared to the wild type from E12.5 to newborn stages. Our data show that the transgenic epidermis undergoes an advanced epidermal differentiation program as compared to the wild type as evidenced morphologically as well as by the expression of K14, K1, loricrin, Cldn6, Cldn18 and Cldn11. In addition, we report for the first time the sequential expression of Cldns in epidermal development and describe that the localization of some Cldns change within the epidermis as it matures. Furthermore, we demonstrate that Cldn6 is expressed very early in epidermal morphogenesis, followed by Cldn18, Cldn11 and Cldn1.

Wet Work and Barrier Function.

PubMed

Fartasch, Manigé

2016-01-01

Wet work defined as unprotected exposure to humid environments/water; high frequencies of hand washing procedures or prolonged glove occlusion is believed to cause irritant contact dermatitis in a variety of occupations. This review considers the recent studies on wet-work exposure and focuses on its influence on barrier function. There are different methods to study the effect of wet work on barrier function. On the one hand, occupational cohorts at risk can be monitored prospectively by skin bioengineering technology and clinical visual scoring systems; on the other hand, experimental test procedures with defined application of water, occlusion and detergents are performed in healthy volunteers. Both epidemiological studies and the results of experimental procedures are compared and discussed. A variety of epidemiological studies analyze occupational cohorts at risk. The measurement of transepidermal water loss, an indicator of the integrity of the epidermal barrier, and clinical inspection of the skin have shown that especially the frequencies of hand washing and water contact/contact to aqueous mixtures seem to be the main factors for the occurrence of barrier alterations. On the other hand, in a single cross-sectional study, prolonged glove wearing (e.g. occlusion for 6 h per shift in clean-room workers) without exposure to additional hazardous substances seemed not to affect the skin negatively. But regarding the effect of occlusion, there is experimental evidence that previously occluded skin challenged with sodium lauryl sulfate leads to an increased susceptibility to the irritant with an aggravation of the irritant reaction. These findings might have relevance for the real-life situation in so far as after occupational glove wearing, the skin is more susceptible to potential hazards to the skin even during leisure hours. © 2016 S. Karger AG, Basel.

Atopic dermatitis and vitamin D: facts and controversies*

PubMed Central

Mesquita, Kleyton de Carvalho; Igreja, Ana Carolina de Souza Machado; Costa, Izelda Maria Carvalho

2013-01-01

Patients with atopic dermatitis have genetically determined risk factors that affect the barrier function of the skin and immune responses that interact with environmental factors. Clinically, this results in an intensely pruriginous and inflamed skin that allows the penetration of irritants and allergens and predisposes patients to colonization and infection by microorganisms. Among the various etiological factors responsible for the increased prevalence of atopic diseases over the past few decades, the role of vitamin D has been emphasized. As the pathogenesis of AD involves a complex interplay of epidermal barrier dysfunction and dysregulated immune response, and vitamin D is involved in both processes, it is reasonable to expect that vitamin D's status could be associated with atopic dermatitis' risk or severity. Such association is suggested by epidemiological and experimental data. In this review, we will discuss the evidence for and against this controversial relationship, emphasizing the possible etiopathogenic mechanisms involved. PMID:24474104

Atopic dermatitis in the domestic dog.

PubMed

Pucheu-Haston, Cherie M

2016-01-01

Dogs may develop a syndrome of spontaneous, inflammatory, pruritic dermatitis that shares many features with human atopic dermatitis, including a young age of onset, characteristic lesion distribution, immunoglobulin E sensitization to common environmental allergen sources, and evidence of epidermal barrier dysfunction. There are also several important differences between canine and human atopic dermatitis. Although dogs may suffer from multiple-organ hypersensitivity syndromes, there is no evidence that this species experiences the progressive evolution from cutaneous to respiratory allergy characteristic of the human atopic march. Despite the presence of epidermal barrier derangement, there is no significant association between canine atopic dermatitis and mutations in filaggrin. Finally, treatment of canine disease relies much less heavily on topical therapy than does its human counterpart, while allergy testing and allergen-specific immunotherapy provide an often essential component of effective clinical management of affected dogs. Copyright © 2016 Elsevier Inc. All rights reserved.

The Roles of Vitamin C in Skin Health

PubMed Central

Pullar, Juliet M.; Carr, Anitra C.; Vissers, Margreet C. M.

2017-01-01

The primary function of the skin is to act as a barrier against insults from the environment, and its unique structure reflects this. The skin is composed of two layers: the epidermal outer layer is highly cellular and provides the barrier function, and the inner dermal layer ensures strength and elasticity and gives nutritional support to the epidermis. Normal skin contains high concentrations of vitamin C, which supports important and well-known functions, stimulating collagen synthesis and assisting in antioxidant protection against UV-induced photodamage. This knowledge is often used as a rationale for the addition of vitamin C to topical applications, but the efficacy of such treatment, as opposed to optimising dietary vitamin C intake, is poorly understood. This review discusses the potential roles for vitamin C in skin health and summarises the in vitro and in vivo research to date. We compare the efficacy of nutritional intake of vitamin C versus topical application, identify the areas where lack of evidence limits our understanding of the potential benefits of vitamin C on skin health, and suggest which skin properties are most likely to benefit from improved nutritional vitamin C intake. PMID:28805671

Environment and the skin

DOE Office of Scientific and Technical Information (OSTI.GOV)

Suskind, R.R.

The effects of the environment on skin are surveyed. Specific patterns of adverse skin response can be characterized by morphological, physiological, and biochemical features. Cutaneous defenses and adaptations of the skin are discussed. Dermal resiliency, epidermal and pigment components, neural components, immunobiological processes, and the epidermal barrier are examined. Percutaneous absorption is reviewed. Environmental factors that cause adverse skin reactions include water, salts of heavy metals, hydrocarbons, solvents, lipids, aromatics, esters, ultraviolet light, and various modalities of ionizing radiation. Pathologic patterns and reaction sites are discussed in terms of inflammatory, allergic, benign epidermal, eccrine sweat gland, and pilosebaceous reactions, pigmentarymore » disturbances, cancer, and blood vessel changes. Although critical epidemiologic data are limited, cutaneous illnesses constitute a significant segment of occupational disease. Recommendations for further research are summarized. 42 references.« less

Postnatal ecdysis establishes the permeability barrier in snake skin: new insights into barrier lipid structures.

PubMed

Tu, M C; Lillywhite, H B; Menon, J G; Menon, G K

2002-10-01

A competent barrier to transepidermal water loss (TEWL) is essential for terrestrial life. In various vertebrates, epidermal water barriers composed of lipids prevent excessive TEWL, which varies inversely with habitat aridity. Little is known, however, about the mechanisms and regulation of permeability relative to natal transition from the 'aqueous' environments of gestation to the 'aerial' environments of terrestrial neonates. We investigated newly hatched California king snakes Lampropeltis getula to test the hypothesis that the first ecdysis is important for establishing the barrier to TEWL. We found that skin resistance to TEWL increases twofold following the first postnatal ecdysis, corresponding with a roughly twofold increase in thickness and deposition of lamellar lipids in the mesos layer, the site of the skin permeability barrier in snakes. In addition, novel observations on lipid inclusions within the alpha layer of epidermis suggest that this layer has functional similarities with avian epidermis. It appears that emergence of the integument from embryonic fluids, and its subsequent pan-body replacement following contact with air, are essential for completion of barrier competence in the newborn. These conditions provide a potentially useful model for investigations on the mechanism of barrier formation. We also found that hatchling snakes are transiently endothermic, with skin temperatures elevated by approximately 0.6 degrees C above ambient air temperature during the period of barrier formation. Behaviourally, hatchlings showed a higher tendency to seek humid microenvironments before the first ecdysis than after. The degree of water movement across the integument might explain the switch from reclusive to dispersive behaviours associated with postnatal ecdysis in snakes.

Epicutaneous aeroallergen sensitization in atopic dermatitis infants - determining the role of epidermal barrier impairment.

PubMed

Boralevi, F; Hubiche, T; Léauté-Labrèze, C; Saubusse, E; Fayon, M; Roul, S; Maurice-Tison, S; Taïeb, A

2008-02-01

Sensitization to atopens is an early phenomenon that overlaps with the onset of atopic dermatitis (AD) in infancy. Early epidermal barrier impairment may facilitate the epicutaneous penetration of atopens. To correlate transepidermal water loss (TEWL) and aeroallergen sensitization in infants with AD. In this cross-sectional study we enrolled 59 AD children and 30 controls aged 3-12 months. Transepidermal water loss in uninvolved skin, specific immunoglobulin E, atopy patch test (APT) and skin prick tests were performed with respect to seven aeroallergens, i.e., Dermatophagoides pteronyssinus, D. farinae, cat, dog, birch pollen, ambrosia, and cockroach. Environmental conditions were assessed by a questionnaire, and the house dust mite (HDM) concentration was determined in dust samples. Eighty-nine percent of AD infants had a positive APT vs one out of eleven controls. AD infants had a significantly higher mean TEWL than controls (27.4 vs 11.1 g/m(2)/h, P < 0001). Children with two or more positive APT had higher TEWL than the others (31.1 vs 19.0 g/m(2)/h, P < 0.025). No correlation was found between indoor APT results and exposure to HDM, cats, and dogs at home. This study confirms the high prevalence of delayed sensitization to indoor and outdoor aeroallergens in AD infants, and shows that the higher the TEWL, the higher the prevalence of sensitization to aeroallergens. These data are in favor of a major role of a constitutive epidermal barrier impairment in determining early atopen sensitization in infants with AD.

Nuclear expression of IL-33 in epidermal keratinocytes promotes wound healing in mice.

PubMed

Oshio, Tomoyuki; Komine, Mayumi; Tsuda, Hidetoshi; Tominaga, Shin-Ichi; Saito, Hirohisa; Nakae, Susumu; Ohtsuki, Mamitaro

2017-02-01

Skin is the outermost tissue of the human body, and works as a mechanical, chemical, and biological barrier. The epidermis is the uppermost layer of the skin, and keratinocytes constitute the majority of epidermal cells. Wounds are disruptions of skin integrity, and cause tremendous disadvantages to humans; accordingly, rapid wound healing is very important. Interleukin (IL)-33 is expressed in barrier tissue cells, such as epithelial and endothelial cells. Upon injury, IL-33 is released to stimulate immune cells, functioning as an "alarmin." ST2 is a receptor for IL-33; its soluble form (s)ST2 acts as a decoy receptor and competes for IL-33 binding. We aimed to clarify the role of IL-33 in wound healing. Wild-type (WT), IL-33 knockout (IL33 KO) mice, and sST2 transgenic (Tg) mice were wounded with a 4-mm punch, and the wound healing process was compared. Immunohistochemical analyses were performed to detect macrophages, neutrophils, and mast cells. Total RNA was extracted from the skin samples and real-time PCR was performed. An in vitro scratch wound assay was performed. Wound healing was delayed in IL33 KO mice compared to WT mice, while wound healing in sST2 Tg mice was comparable to that of WT mice. A histological examination showed delayed elongation of the epidermal tongue in IL-33 KO mice. An immunohistochemical study revealed prolonged neutrophilic infiltration at a later stage in IL-33 KO mice. IL-6, IL-1β, and CXCL1 transcripts were more abundant in the wounds of IL-33 KO mice than WT mice. Intraperitoneal administration of an NFκB inhibitor to IL-33 KO mice normalized the delayed wound healing and the enhanced expression of IL-6 in IL-33 KO mice. Epidermal keratinocytes from IL-33 KO mice showed delayed wound closure compared to those from WT mice. Our results indicate that nuclear IL-33, but not IL-33 as a cytokine, has beneficial effects on wound healing in mice, probably by suppressing NFκB to inhibit excessive inflammation and by maintaining keratinocyte proliferation or migration for epithelialization. Copyright © 2016 Japanese Society for Investigative Dermatology. Published by Elsevier B.V. All rights reserved.

NOVEL MECHANISMS FOR THE VITAMIN D RECEPTOR (VDR) IN THE SKIN AND IN SKIN CANCER

PubMed Central

Bikle, Daniel D.; Oda, Yuko; Tu, Chia-Ling; Jiang, Yan

2014-01-01

The VDR acting with or without its principal ligand 1,25(OH)2D regulates two central processes in the skin, interfollicular epidermal (IFE) differentiation and hair follicle cycling (HFC). Calcium is an important co-regulator with 1,25(OH)2 D at least of epidermal differentiation. Knockout of the calcium sensing receptor (CaSR) in addition to VDR accelerates the development of skin cancer in mice on a low calcium diet. Coactivators such as Mediator 1 (aka DRIP205) and steroid receptor coactivator 3 (SRC3) regulate VDR function at different stages of the differentiation process, with Med1 essential for hair follicle differentiation and early stages of epidermal differentiation and proliferation and SRC3 essential for the latter stages of differentiation including formation of the permeability barrier and innate immunity. The corepressor of VDR, hairless (HR), is essential for hair follicle cycling, although its effect on epidermal differentiation in vivo is minimal. In its regulation of HFC and IFE VDR controls two pathways—wnt/β-catenin and sonic hedgehog (Shh). In the absence of VDR these pathways are overexpressed leading to tumor formation. Whereas VDR binding to β-catenin may block its activation of TCF/LEF1 sites, β-catenin binding to VDR may enhance its activation of VDREs. 1,25(OH)2D promotes but may not be required for these interactions. Suppression of Shh expression by VDR, on the other hand, requires 1,25(OH)2D. The major point of emphasis is that the role of VDR in the skin involves a number of novel mechanisms, both 1,25(OH)2D dependent and independent, that when disrupted interfere with IFE differentiation and HFC, predisposing to cancer formation. PMID:25445917

The epidermal Ca(2+) gradient: Measurement using the phasor representation of fluorescent lifetime imaging.

PubMed

Celli, A; Sanchez, S; Behne, M; Hazlett, T; Gratton, E; Mauro, T

2010-03-03

Ionic gradients are found across a variety of tissues and organs. In this report, we apply the phasor representation of fluorescence lifetime imaging data to the quantitative study of ionic concentrations in tissues, overcoming technical problems of tissue thickness, concentration artifacts of ion-sensitive dyes, and calibration across inhomogeneous tissue. We used epidermis as a model system, as Ca(2+) gradients in this organ have been shown previously to control essential biologic processes of differentiation and formation of the epidermal permeability barrier. The approach described here allowed much better localization of Ca(2+) stores than those used in previous studies, and revealed that the bulk of free Ca(2+) measured in the epidermis comes from intracellular Ca(2+) stores such as the Golgi and the endoplasmic reticulum, with extracellular Ca(2+) making a relatively small contribution to the epidermal Ca(2+) gradient. Due to the high spatial resolution of two-photon microscopy, we were able to measure a marked heterogeneity in average calcium concentrations from cell to cell in the basal keratinocytes. This finding, not reported in previous studies, calls into question the long-held hypothesis that keratinocytes increase intracellular Ca(2+), cease proliferation, and differentiate passively in response to changes in extracellular Ca(2+). The experimental results obtained using this approach illustrate the power of the experimental and analytical techniques outlined in this report. Our approach can be used in mechanistic studies to address the formation, maintenance, and function of the epidermal Ca(2+) gradient, and it should be broadly applicable to the study of other tissues with ionic gradients. 2010 Biophysical Society. Published by Elsevier Inc. All rights reserved.

Structure of the integument of southern right whales, Eubalaena australis.

PubMed

Reeb, Desray; Best, Peter Barrington; Kidson, Susan Hillary

2007-06-01

Skin (integument) anatomy reflects adaptations to particular environments. It is hypothesized that cetacean (whale) integument will show unique anatomical adaptations to an aquatic environment, particularly regarding differences in temperature, density, and pressure. In this study, the gross and histological structure of the southern right whale integument is described and compared with terrestrial mammals and previous descriptions of mysticete (baleen whale) and odontocete (toothed whale) species. Samples were taken of the integument of 98 free-swimming southern right whales, Eubalaena australis, and examined by both light and electron microscopy. Results show that three epidermal layers are present, with the stratum corneum being parakeratotic in nature. As in bowhead whales, southern right whales possess an acanthotic epidermis and a notably thick hypodermis, with epidermal rods and extensive papillomatosis. However, unlike bowhead whales, southern right whales possess an uninterrupted hypodermal layer. Surprisingly, the integument of balaenids (right and bowhead mysticetes) in general is more like that of odontocetes than that of the more closely related balaenopterids (rorqual mysticetes). Similarities to odontocetes were found specifically in the collagen fibers in a fat-free zone of the reticular dermal layer and the elastic fibers in the dermal and hypodermal layers. Callosities, a distinctive feature of this genus, have a slightly thicker stratum corneum and are usually associated with hairs that have innervated and vascularized follicles. These hairs may function as vibrissae, thus aiding in aquatic foraging by allowing rapid detection of changes in prey density. Although the thick insulatory integument makes right whales bulky and slow-moving, it is an adaptation for living in cold water. Epidermal thickness, presence of epidermal rods, and callosities may act as barriers against mechanical injury from bodily contact with conspecifics or hard surfaces in the environment (e.g., rocks, ice). 2007 Wiley-Liss, Inc.

Studies on the relationship between epidermal cell turnover kinetics and permeability of hairless mouse skin

DOE Office of Scientific and Technical Information (OSTI.GOV)

Han, S.R.

The primary aim of this study was to develop non-invasive, physical means to quantitatively assess the epidermal turnover kinetics and barrier properties of the skin and relate these to the cutaneous irritation which results from ultraviolet light irradiation and mold thermal burns. After systematically injecting radiolabeled glycine, the appearance of radioactivity at the skin's surface indicated the transit time of radiolabeled cells through the skin. By plotting the data as the cumulative specific activity against time and then fitting them with a third order polynomial equation, it is possible to estimate the turnover time of the stratum corneum. The skinmore » turnover was coordinated with non-invasive transepidermal water loss (TEWL) studies determined with an evaporimeter. In vitro diffusion studies of the permeability of hydrocortisone through UVB irradiated and thermally burned skin were also performed. The studies indicated that irritated skin offers a relatively low diffusional resistance to hydrocortisone. Depending on the severity of the trauma, the increases in hydrocortisone's permeability coefficient through irritated skin ranged from a low of about 2 times normal to a high of about 210 times normal. Trauma-induced changes in hydrocortisone permeability parallel changes in TEWL, proving that the barrier deficient state resulting from rapid epidermal turnover is a general phenomenon.« less

The organization of human epidermis: functional epidermal units and phi proportionality.

PubMed

Hoath, Steven B; Leahy, D G

2003-12-01

The concept that mammalian epidermis is structurally organized into functional epidermal units has been proposed on the basis of stratum corneum (SC) architecture, proliferation kinetics, melanocyte:keratinocyte ratios (1:36), and, more recently, Langerhans cell: epidermal cell ratios (1:53). This article examines the concept of functional epidermal units in human skin in which the maintenance of phi (1.618034) proportionality provides a central organizing principle. The following empirical measurements were used: 75,346 nucleated epidermal cells per mm2, 1394 Langerhans cells per mm2, 1999 melanocytes per mm2, 16 (SC) layers, 900-microm2 corneocyte surface area, 17,778 corneocytes per mm2, 14-d (SC) turnover time, and 93,124 per mm2 total epidermal cells. Given these empirical data: (1) the number of corneocytes is a mean proportional between the sum of the Langerhans cell + melanocyte populations and the number of epidermal cells, 3393/17,778-17,778/93,124; (2) the ratio of nucleated epidermal cells over corneocytes is phi proportional, 75,346/17,778 approximately phi3; (3) assuming similar 14-d turnover times for the (SC) and Malpighian epidermis, the number of corneocytes results from subtraction of a cellular fraction equal to approximately 2/phi2 x the number of living cells, 75,436 - (2/phi2 x 75,346) approximately 17,778; and (4) if total epidermal turnover time equals (SC) turnover time x the ratio of living/dead cells, then compartmental turnover times are unequal (14 d for (SC) to 45.3 d for nucleated epidermis approximately 1/2phi) and cellular replacement rates are 52.9 corneocytes/69.3 keratinocytes per mm2 per h approximately 2/phi2. These empirically derived equivalences provide logicomathematical support for the presence of functional epidermal units in human skin. Validation of a phi proportional unit architecture in human epidermis will be important for tissue engineering of skin and the design of instruments for skin measurement.

[Enhanced lymphocyte proliferation in the presence of epidermal cells of HIV-infected patients in vitro].

PubMed

Kappus, R P; Berger, S; Thomas, C A; Ottmann, O G; Ganser, A; Stille, W; Shah, P M

1992-07-01

Clinical observations show that the HIV infection is often associated with affections of the skin. In order to examine the involvement of the epidermal immune system in the HIV infection, we determined accessory cell function of epidermal cells from HIV-1-infected patients. For this we measured the proliferative response of enriched CD(4+)-T-lymphocytes from HIV-infected patients and noninfected controls to stimulation with anti-CD3 and IL-2 in the presence of epidermal cells; the enhancement of the response is dependent on the presence of functionally intact accessory cells. The capacity of epidermal cells to increase the anti-CD3-stimulated T-cell proliferative response was significantly enhanced in HIV patients (CDC III/IVA) as compared with noninfected donors. It is discussed, whether the increased activity of epidermal cells from HIV-infected patients may be responsible for several of the dermal lesions in the course of an HIV infection as due to an enhanced production and release of epidermal cell-derived cytokines.

Distribution of apple fruit epidermal non-polar metabolites

USDA-ARS?s Scientific Manuscript database

Apple peel epidermis provides a resilient protective barrier against external stimuli while, also, comprising much of what is considered as fruit appearance and related phenotypic components. This dynamic structure is subject to many changes throughout the production and supply chain that can impac...

Coal tar induces AHR-dependent skin barrier repair in atopic dermatitis

PubMed Central

van den Bogaard, Ellen H.; Bergboer, Judith G.M.; Vonk-Bergers, Mieke; van Vlijmen-Willems, Ivonne M.J.J.; Hato, Stanleyson V.; van der Valk, Pieter G.M.; Schröder, Jens Michael; Joosten, Irma; Zeeuwen, Patrick L.J.M.; Schalkwijk, Joost

2013-01-01

Topical application of coal tar is one of the oldest therapies for atopic dermatitis (AD), a T helper 2 (Th2) lymphocyte–mediated skin disease associated with loss-of-function mutations in the skin barrier gene, filaggrin (FLG). Despite its longstanding clinical use and efficacy, the molecular mechanism of coal tar therapy is unknown. Using organotypic skin models with primary keratinocytes from AD patients and controls, we found that coal tar activated the aryl hydrocarbon receptor (AHR), resulting in induction of epidermal differentiation. AHR knockdown by siRNA completely abrogated this effect. Coal tar restored filaggrin expression in FLG-haploinsufficient keratinocytes to wild-type levels, and counteracted Th2 cytokine–mediated downregulation of skin barrier proteins. In AD patients, coal tar completely restored expression of major skin barrier proteins, including filaggrin. Using organotypic skin models stimulated with Th2 cytokines IL-4 and IL-13, we found coal tar to diminish spongiosis, apoptosis, and CCL26 expression, all AD hallmarks. Coal tar interfered with Th2 cytokine signaling via dephosphorylation of STAT6, most likely due to AHR-regulated activation of the NRF2 antioxidative stress pathway. The therapeutic effect of AHR activation herein described opens a new avenue to reconsider AHR as a pharmacological target and could lead to the development of mechanism-based drugs for AD. PMID:23348739

Coal tar induces AHR-dependent skin barrier repair in atopic dermatitis.

PubMed

van den Bogaard, Ellen H; Bergboer, Judith G M; Vonk-Bergers, Mieke; van Vlijmen-Willems, Ivonne M J J; Hato, Stanleyson V; van der Valk, Pieter G M; Schröder, Jens Michael; Joosten, Irma; Zeeuwen, Patrick L J M; Schalkwijk, Joost

2013-02-01

Topical application of coal tar is one of the oldest therapies for atopic dermatitis (AD), a T helper 2 (Th2) lymphocyte-mediated skin disease associated with loss-of-function mutations in the skin barrier gene, filaggrin (FLG). Despite its longstanding clinical use and efficacy, the molecular mechanism of coal tar therapy is unknown. Using organotypic skin models with primary keratinocytes from AD patients and controls, we found that coal tar activated the aryl hydrocarbon receptor (AHR), resulting in induction of epidermal differentiation. AHR knockdown by siRNA completely abrogated this effect. Coal tar restored filaggrin expression in FLG-haploinsufficient keratinocytes to wild-type levels, and counteracted Th2 cytokine-mediated downregulation of skin barrier proteins. In AD patients, coal tar completely restored expression of major skin barrier proteins, including filaggrin. Using organotypic skin models stimulated with Th2 cytokines IL-4 and IL-13, we found coal tar to diminish spongiosis, apoptosis, and CCL26 expression, all AD hallmarks. Coal tar interfered with Th2 cytokine signaling via dephosphorylation of STAT6, most likely due to AHR-regulated activation of the NRF2 antioxidative stress pathway. The therapeutic effect of AHR activation herein described opens a new avenue to reconsider AHR as a pharmacological target and could lead to the development of mechanism-based drugs for AD.

Simultaneous cell death and desquamation of the embryonic diffusion barrier during epidermal development.

PubMed

Saathoff, Manuela; Blum, Barbara; Quast, Thomas; Kirfel, Gregor; Herzog, Volker

2004-10-01

The periderm is an epithelial layer covering the emerging epidermis in early embryogenesis of vertebrates. In the chicken embryo, an additional cellular layer, the subperiderm, occurs at later embryonic stages underneath the periderm. The questions arose what is the function of both epithelial layers and, as they are transitory structures, by which mechanism are they removed. By immunocytochemistry, the tight junction (TJ) proteins occludin and claudin-1 were localized in the periderm and in the subperiderm, and sites of close contact between adjacent cells were detected by electron microscopy. Using horseradish peroxidase (HRP) as tracer, these contacts were identified as tight junctions involved in the formation of the embryonic diffusion barrier. This barrier was lost by desquamation at the end of the embryonic period, when the cornified envelope of the emerging epidermis was formed. By TUNEL and DNA ladder assays, we detected simultaneous cell death in the periderm and the subperiderm shortly before hatching. The absence of caspases-3, -6, and -7 activity, key enzymes of apoptosis, and the lack of typical morphological criteria of apoptosis such as cell fragmentation or membrane blebbing point to a special form of programmed cell death (PCD) leading to the desquamation of the embryonic diffusion barrier. Copyright 2004 Elsevier Inc.

GATA3 Expression Is Decreased in Psoriasis and during Epidermal Regeneration; Induction by Narrow-Band UVB and IL-4

PubMed Central

Kant, Marius; Baerveldt, Ewout M.; Florencia, Edwin; Mourits, Sabine; de Ridder, Dick; Laman, Jon D.; van der Fits, Leslie; Prens, Errol P.

2011-01-01

Psoriasis is characterized by hyperproliferation of keratinocytes and by infiltration of activated Th1 and Th17 cells in the (epi)dermis. By expression microarray, we previously found the GATA3 transcription factor significantly downregulated in lesional psoriatic skin. Since GATA3 serves as a key switch in both epidermal and T helper cell differentiation, we investigated its function in psoriasis. Because psoriatic skin inflammation shares many characteristics of epidermal regeneration during wound healing, we also studied GATA3 expression under such conditions. Psoriatic lesional skin showed decreased GATA3 mRNA and protein expression compared to non-lesional skin. GATA3 expression was also markedly decreased in inflamed skin of mice with a psoriasiform dermatitis induced with imiquimod. Tape-stripping of non-lesional skin of patients with psoriasis, a standardized psoriasis-triggering and skin regeneration-inducing technique, reduced the expression of GATA3. In wounded skin of mice, low GATA3 mRNA and protein expression was detected. Taken together, GATA3 expression is downregulated under regenerative and inflammatory hyperproliferative skin conditions. GATA3 expression could be re-induced by successful narrow-band UVB treatment of both human psoriasis and imiquimod-induced psoriasiform dermatitis in mice. The prototypic Th2 cytokine IL-4 was the only cytokine capable of inducing GATA3 in skin explants from healthy donors. Based on these findings we argue that GATA3 serves as a key regulator in psoriatic inflammation, keratinocyte hyperproliferation and skin barrier dysfunction. PMID:21611195

Epidermal Growth Factor Relieves Inflammatory Signals in Staphylococcus aureus-Treated Human Epidermal Keratinocytes and Atopic Dermatitis-Like Skin Lesions in Nc/Nga Mice

PubMed Central

Choi, Sun Young; Lee, You Jin; Kim, Ji Min; Kang, Hyun Ji

2018-01-01

Atopic dermatitis (AD) is a chronic inflammatory skin disease with a defective immunologic barrier, which is aggravated by Staphylococcus aureus (S. aureus). Epidermal growth factor (EGF) suppresses inflammation and EGF receptor inhibitors increased S. aureus colonization. Thus, we investigated the potential roles of EGF in AD, which is often aggravated by S. aureus. We determined how EGF affects the expression of inflammatory cytokines and antimicrobial peptides (AMPs) in human epidermal keratinocytes (HEKs) treated with heat-inactivated S. aureus (HKSA) in vitro and 2,4-dinitrochlorobenzene-induced AD-like skin lesions in Nc/Nga mice. HKSA increased IL-6 and NFκB expression; EGF treatment had the opposite effect. EGF increased human β defensin-2 expression in HEKs and murine β defensin-3 in mice. In mice, both EGF and pimecrolimus groups showed less erythema with significantly reduced inflammation and decreased expression of thymic stromal lymphopoietin. EGF relieved S. aureus-induced inflammation and AD-like skin lesions in Nc/Nga mice. Therefore, EGF could be a potential topical treatment for AD.

Epidermal Growth Factor Relieves Inflammatory Signals in Staphylococcus aureus-Treated Human Epidermal Keratinocytes and Atopic Dermatitis-Like Skin Lesions in Nc/Nga Mice.

PubMed

Choi, Sun Young; Lee, You Jin; Kim, Ji Min; Kang, Hyun Ji; Cho, Sang Hyun; Chang, Sung Eun

2018-01-01

Atopic dermatitis (AD) is a chronic inflammatory skin disease with a defective immunologic barrier, which is aggravated by Staphylococcus aureus (S. aureus) . Epidermal growth factor (EGF) suppresses inflammation and EGF receptor inhibitors increased S. aureus colonization. Thus, we investigated the potential roles of EGF in AD, which is often aggravated by S. aureus . We determined how EGF affects the expression of inflammatory cytokines and antimicrobial peptides (AMPs) in human epidermal keratinocytes (HEKs) treated with heat-inactivated S. aureus (HKSA) in vitro and 2,4-dinitrochlorobenzene-induced AD-like skin lesions in Nc/Nga mice. HKSA increased IL-6 and NF κ B expression; EGF treatment had the opposite effect. EGF increased human β defensin-2 expression in HEKs and murine β defensin-3 in mice. In mice, both EGF and pimecrolimus groups showed less erythema with significantly reduced inflammation and decreased expression of thymic stromal lymphopoietin. EGF relieved S. aureus -induced inflammation and AD-like skin lesions in Nc/Nga mice. Therefore, EGF could be a potential topical treatment for AD.

Transient elevation of cytoplasmic calcium ion concentration at a single cell level precedes morphological changes of epidermal keratinocytes during cornification.

PubMed

Murata, Teruasa; Honda, Tetsuya; Egawa, Gyohei; Yamamoto, Yasuo; Ichijo, Ryo; Toyoshima, Fumiko; Dainichi, Teruki; Kabashima, Kenji

2018-04-26

Epidermal keratinocytes achieve sequential differentiation from basal to granular layers, and undergo a specific programmed cell death, cornification, to form an indispensable barrier of the body. Although elevation of the cytoplasmic calcium ion concentration ([Ca 2+ ] i ) is one of the factors predicted to regulate cornification, the dynamics of [Ca 2+ ] i in epidermal keratinocytes is largely unknown. Here using intravital imaging, we captured the dynamics of [Ca 2+ ] i in mouse skin. [Ca 2+ ] i was elevated in basal cells on the second time scale in three spatiotemporally distinct patterns. The transient elevation of [Ca 2+ ] i also occurred at the most apical granular layer at a single cell level, and lasted for approximately 40 min. The transient elevation of [Ca 2+ ] i at the granular layer was followed by cornification, which was completed within 10 min. This study demonstrates the tightly regulated elevation of [Ca 2+ ] i preceding the cornification of epidermal keratinocytes, providing possible clues to the mechanisms of cornification.

Genes that mediate breast cancer metastasis to the brain.

PubMed

Bos, Paula D; Zhang, Xiang H-F; Nadal, Cristina; Shu, Weiping; Gomis, Roger R; Nguyen, Don X; Minn, Andy J; van de Vijver, Marc J; Gerald, William L; Foekens, John A; Massagué, Joan

2009-06-18

The molecular basis for breast cancer metastasis to the brain is largely unknown. Brain relapse typically occurs years after the removal of a breast tumour, suggesting that disseminated cancer cells must acquire specialized functions to take over this organ. Here we show that breast cancer metastasis to the brain involves mediators of extravasation through non-fenestrated capillaries, complemented by specific enhancers of blood-brain barrier crossing and brain colonization. We isolated cells that preferentially infiltrate the brain from patients with advanced disease. Gene expression analysis of these cells and of clinical samples, coupled with functional analysis, identified the cyclooxygenase COX2 (also known as PTGS2), the epidermal growth factor receptor (EGFR) ligand HBEGF, and the alpha2,6-sialyltransferase ST6GALNAC5 as mediators of cancer cell passage through the blood-brain barrier. EGFR ligands and COX2 were previously linked to breast cancer infiltration of the lungs, but not the bones or liver, suggesting a sharing of these mediators in cerebral and pulmonary metastases. In contrast, ST6GALNAC5 specifically mediates brain metastasis. Normally restricted to the brain, the expression of ST6GALNAC5 in breast cancer cells enhances their adhesion to brain endothelial cells and their passage through the blood-brain barrier. This co-option of a brain sialyltransferase highlights the role of cell-surface glycosylation in organ-specific metastatic interactions.

Cyclic Alopecia and Abnormal Epidermal Cornification in Zdhhc13-Deficient Mice Reveal the Importance of Palmitoylation in Hair and Skin Differentiation.

PubMed

Liu, Kai-Ming; Chen, Yi-Ju; Shen, Li-Fen; Haddad, Amir N S; Song, I-Wen; Chen, Li-Ying; Chen, Yu-Ju; Wu, Jer-Yuarn; Yen, Jeffrey J Y; Chen, Yuan-Tsong

2015-11-01

Many biochemical pathways involved in hair and skin development have not been investigated. Here, we reported on the lesions and investigated the mechanism underlying hair and skin abnormalities in Zdhhc13(skc4) mice with a deficiency in DHHC13, a palmitoyl-acyl transferase encoded by Zdhhc13. Homozygous affected mice showed ragged and dilapidated cuticle of the hair shaft (CUH, a hair anchoring structure), poor hair anchoring ability, and premature hair loss at early telogen phase of the hair cycle, resulting in cyclic alopecia. Furthermore, the homozygous affected mice exhibited hyperproliferation of the epidermis, disturbed cornification, fragile cornified envelope (CE, a skin barrier structure), and impaired skin barrier function. Biochemical investigations revealed that cornifelin, which contains five palmitoylation sites at cysteine residues (C58, C59, C60, C95, and C101), was a specific substrate of DHHC13 and that it was absent in the CUH and CE structures of the affected mice. Furthermore, cornifelin levels were markedly reduced when two palmitoylated cysteines were replaced with serine (C95S and C101S). Taken together, our results suggest that DHHC13 is important for hair anchoring and skin barrier function and that cornifelin deficiency contributes to cyclic alopecia and skin abnormalities in Zdhhc13(skc4) mice.

Effect of soaps and detergents on epidermal barrier function.

PubMed

Wolf, Ronni; Parish, Lawrence Charles

2012-01-01

The past decade has witnessed an explosion of new impartial information about the complex interaction of the skin with topically applied substances, including soaps and detergents. Despite of all these new data, our knowledge on the exact pathomechanism and molecular events leading to detergent-induced barrier dysfunction remains incomplete and the answers continue to elude us. The longtime prevailing opinion which contends that the damaging effect of soaps and detergents is related to their property to extract and remove useful intercellular lipids has mostly been abandoned. Although this effect might be involved in the damaging effect, it is definitely not the sole mechanism, nor, indeed, is it even the main one. Skin proteins damage, the interaction with keratins and their denaturation, swelling of cell membranes and collagen fibers, cytotoxicity expressed with cellular lysis are other important mechanisms. One proposed mechanism is that an initial stratum corneum hyper-hydration results from a continuous disruption of the secondary and tertiary structures of keratin protein by surfactants, exposing new water-binding sites, thereby increasing the hydration of the membrane. Following evaporation of excess water, the denatured keratin possesses a decreased water-binding capacity and decreased ability to function as a barrier. Recent studies have also emphasized the effects of detergents on lipid synthesis, on lipid-metabolizing enzymes and on keratinocyte differentiation. Copyright © 2012 Elsevier Inc. All rights reserved.

IL-33 promotes an innate immune pathway of intestinal tissue protection dependent on amphiregulin-EGFR interactions.

PubMed

Monticelli, Laurel A; Osborne, Lisa C; Noti, Mario; Tran, Sara V; Zaiss, Dietmar M W; Artis, David

2015-08-25

The barrier surfaces of the skin, lung, and intestine are constantly exposed to environmental stimuli that can result in inflammation and tissue damage. Interleukin (IL)-33-dependent group 2 innate lymphoid cells (ILC2s) are enriched at barrier surfaces and have been implicated in promoting inflammation; however, the mechanisms underlying the tissue-protective roles of IL-33 or ILC2s at surfaces such as the intestine remain poorly defined. Here we demonstrate that, following activation with IL-33, expression of the growth factor amphiregulin (AREG) is a dominant functional signature of gut-associated ILC2s. In the context of a murine model of intestinal damage and inflammation, the frequency and number of AREG-expressing ILC2s increases following intestinal injury and genetic disruption of the endogenous AREG-epidermal growth factor receptor (EGFR) pathway exacerbated disease. Administration of exogenous AREG limited intestinal inflammation and decreased disease severity in both lymphocyte-sufficient and lymphocyte-deficient mice, revealing a previously unrecognized innate immune mechanism of intestinal tissue protection. Furthermore, treatment with IL-33 or transfer of ILC2s ameliorated intestinal disease severity in an AREG-dependent manner. Collectively, these data reveal a critical feedback loop in which cytokine cues from damaged epithelia activate innate immune cells to express growth factors essential for ILC-dependent restoration of epithelial barrier function and maintenance of tissue homeostasis.

Additive impairment of the barrier function and irritation by biogenic amines and sodium lauryl sulphate: a controlled in vivo tandem irritation study.

PubMed

Fluhr, J W; Kelterer, D; Fuchs, S; Kaatz, M; Grieshaber, R; Kleesz, P; Elsner, P

2005-01-01

Biogenic amines are potential irritants e.g. in fish-, meat-, milk- and egg-processing professions like cooks, butchers and bakers. The aim of this study was to test the irritative and barrier-disrupting properties of the biogenic amines ammonium hydroxide (AM), dimethylamine (DMA) and trimethylamine (TMA). A repeated sequential irritation of 30 min twice per day was performed over a total of 4 days (tandem repeated irritation test) on the back of 20 healthy volunteers of both sexes with AM, DMA, TMA and sodium lauryl sulphate (SLS). The epidermal barrier function was assessed with a Tewameter TM 210, stratum corneum surface pH was measured with a Skin-pH-Meter 900, inflammation was assessed with a Chromameter CR-300 on the a* axis for redness and a visual score was recorded. All tested biogenic amines (AM, DMA and TMA) induced a barrier disruption and a pH increase paralleled with a 1-day-delayed onset of inflammatory signs. These effects were further enhanced and accelerated by a sequential application of SLS together with the biogenic amines, and inflammation occurred earlier than with the single compounds. Acetic acid (AA) in contrast did only show mild barrier disruption and no significant inflammatory signs. Our system allowed a ranking of the different compounds in their irritative potential in the tandem irritation with SLS: SLS > NaOH > TMA > AA > AM > DMA. The results are suggestive that in the food-processing industry the simultaneous contact with biogenic amines and harmful detergents like SLS should be minimized. Copyright 2005 S. Karger AG, Basel.

Genetic and pharmacological analysis identifies a physiological role for the AHR in epidermal differentiation

PubMed Central

van den Bogaard, Ellen; Podolsky, Michael; Smits, Jos; Cui, Xiao; John, Christian; Gowda, Krishne; Desai, Dhimant; Amin, Shantu; Schalkwijk, Joost; Perdew, Gary H.

2015-01-01

Stimulation of the aryl hydrocarbon receptor (AHR) by xenobiotics is known to affect epidermal differentiation and skin barrier formation. The physiological role of endogenous AHR signaling in keratinocyte differentiation is not known. We used murine and human skin models to address the hypothesis that AHR activation is required for normal keratinocyte differentiation. Using transcriptome analysis of Ahr-/- and Ahr+/+ murine keratinocytes, we found significant enrichment of differentially expressed genes linked to epidermal differentiation. Primary Ahr-/- keratinocytes showed a significant reduction in terminal differentiation gene and protein expression, similar to Ahr+/+ keratinocytes treated with AHR antagonists GNF351 and CH223191, or the selective AHR modulator (SAhRM), SGA360. In vitro keratinocyte differentiation led to increased AHR levels and subsequent nuclear translocation, followed by induced CYP1A1 gene expression. Monolayer cultured primary human keratinocytes treated with AHR antagonists also showed an impaired terminal differentiation program. Inactivation of AHR activity during human skin equivalent development severely impaired epidermal stratification, terminal differentiation protein expression and stratum corneum formation. As disturbed epidermal differentiation is a main feature of many skin diseases, pharmacological agents targeting AHR signaling or future identification of endogenous keratinocyte-derived AHR ligands should be considered as potential new drugs in dermatology. PMID:25602157

Loss of corneodesmosin leads to severe skin barrier defect, pruritus, and atopy: unraveling the peeling skin disease.

PubMed

Oji, Vinzenz; Eckl, Katja-Martina; Aufenvenne, Karin; Nätebus, Marc; Tarinski, Tatjana; Ackermann, Katharina; Seller, Natalia; Metze, Dieter; Nürnberg, Gudrun; Fölster-Holst, Regina; Schäfer-Korting, Monika; Hausser, Ingrid; Traupe, Heiko; Hennies, Hans Christian

2010-08-13

Generalized peeling skin disease is an autosomal-recessive ichthyosiform erythroderma characterized by lifelong patchy peeling of the skin. After genome-wide linkage analysis, we have identified a homozygous nonsense mutation in CDSN in a large consanguineous family with generalized peeling skin, pruritus, and food allergies, which leads to a complete loss of corneodesmosin. In contrast to hypotrichosis simplex, which can be associated with specific dominant CDSN mutations, peeling skin disease is characterized by a complete loss of CDSN expression. The skin phenotype is consistent with a recent murine Cdsn knockout model. Using three-dimensional human skin models, we demonstrate that lack of corneodesmosin causes an epidermal barrier defect supposed to account for the predisposition to atopic diseases, and we confirm the role of corneodesmosin as a decisive epidermal adhesion molecule. Therefore, peeling skin disease will represent a new model disorder for atopic diseases, similarly to Netherton syndrome and ichthyosis vulgaris in the recent past.

Loss of Corneodesmosin Leads to Severe Skin Barrier Defect, Pruritus, and Atopy: Unraveling the Peeling Skin Disease

PubMed Central

Oji, Vinzenz; Eckl, Katja-Martina; Aufenvenne, Karin; Nätebus, Marc; Tarinski, Tatjana; Ackermann, Katharina; Seller, Natalia; Metze, Dieter; Nürnberg, Gudrun; Fölster-Holst, Regina; Schäfer-Korting, Monika; Hausser, Ingrid; Traupe, Heiko; Hennies, Hans Christian

2010-01-01

Generalized peeling skin disease is an autosomal-recessive ichthyosiform erythroderma characterized by lifelong patchy peeling of the skin. After genome-wide linkage analysis, we have identified a homozygous nonsense mutation in CDSN in a large consanguineous family with generalized peeling skin, pruritus, and food allergies, which leads to a complete loss of corneodesmosin. In contrast to hypotrichosis simplex, which can be associated with specific dominant CDSN mutations, peeling skin disease is characterized by a complete loss of CDSN expression. The skin phenotype is consistent with a recent murine Cdsn knockout model. Using three-dimensional human skin models, we demonstrate that lack of corneodesmosin causes an epidermal barrier defect supposed to account for the predisposition to atopic diseases, and we confirm the role of corneodesmosin as a decisive epidermal adhesion molecule. Therefore, peeling skin disease will represent a new model disorder for atopic diseases, similarly to Netherton syndrome and ichthyosis vulgaris in the recent past. PMID:20691404

An ex vivo human skin model for studying skin barrier repair.

PubMed

Danso, Mogbekeloluwa O; Berkers, Tineke; Mieremet, Arnout; Hausil, Farzia; Bouwstra, Joke A

2015-01-01

In the studies described in this study, we introduce a novel ex vivo human skin barrier repair model. To develop this, we removed the upper layer of the skin, the stratum corneum (SC) by a reproducible cyanoacrylate stripping technique. After stripping the explants, they were cultured in vitro to allow the regeneration of the SC. We selected two culture temperatures 32 °C and 37 °C and a period of either 4 or 8 days. After 8 days of culture, the explant generated SC at a similar thickness compared to native human SC. At 37 °C, the early and late epidermal differentiation programmes were executed comparably to native human skin with the exception of the barrier protein involucrin. At 32 °C, early differentiation was delayed, but the terminal differentiation proteins were expressed as in stripped explants cultured at 37 °C. Regarding the barrier properties, the SC lateral lipid organization was mainly hexagonal in the regenerated SC, whereas the lipids in native human SC adopt a more dense orthorhombic organization. In addition, the ceramide levels were higher in the cultured explants at 32 °C and 37 °C than in native human SC. In conclusion, we selected the stripped ex vivo skin model cultured at 37 °C as a candidate model to study skin barrier repair because epidermal and SC characteristics mimic more closely the native human skin than the ex vivo skin model cultured at 32 °C. Potentially, this model can be used for testing formulations for skin barrier repair. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Fibroblast Growth Factor-Peptide Improves Barrier Function and Proliferation in Human Keratinocytes After Radiation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang Kunzhong; Tian Yeping; Yin Liangjie

2011-09-01

Purpose: Epidermal keratinocytes, which can be severely damaged after ionizing radiation (IR), are rapid turnover cells that function as a barrier, protecting the host from pathogenic invasion and fluid loss. We tested fibroblast growth factor-peptide (FGF-P), a small peptide derived from the receptor-binding domain of FGF-2, as a potential mitigator of radiation effects via proliferation and the barrier function of keratinocytes. Methods and Materials: Keratinocytes isolated from neonatal foreskin were grown on transwells. After being exposed to 0, 5, or 10 Gy IR, the cells were treated with a vehicle or FGF-P. The permeability of IR cells was assessed bymore » using transepithelial electrical resistance (TEER) and a paracellular tracer flux of fluorescein isothiocyanate-conjugated bovine serum albumin (FITC-BSA) with Ussing chambers. The cell proliferation was measured with yellow tetrazolium salt (MTT) and tritiated thymidine ([{sup 3}H]-TdR) assays. The phosphorylation of extracellular signal-regulated kinases (ERK) was measured in an enzyme-linked immunosorbent (ELISA)-like assay, and the proteins related to tight junctions (TJ) and adherens junctions (AJ) were examined with Western blotting. We used a mouse model to assess the ability of FGF-P to promote the healing of skin {beta} burns created with a strontium applicator. Results: We found (1) FGF-P reduced the permeability of irradiated keratinocytes, as evidenced by increased TEER and decreased diffusion of FITC-BSA, both associated with the regulation of different proteins and levels of TJ and AJ; and (2) FGF-P enhanced the proliferation of irradiated keratinocytes, as evidenced by increased MTT activity and [{sup 3}H]-TdR incorporation, which was associated with activation of the ERK pathway; and (3) FGF-P promoted the healing of skin {beta} burns. Conclusions: FGF-P enhances the barrier function, including up-regulation of TJ proteins, increases proliferation of human keratinocytes, and accelerates the healing of skin {beta} burns. FGF-P is a promising mitigator that improves the proliferation and barrier function of keratinocytes after IR.« less

Role of macromolecules in the safety of use of body wash cosmetics.

PubMed

Bujak, Tomasz; Wasilewski, Tomasz; Nizioł-Łukaszewska, Zofia

2015-11-01

One of the most challenging problems related to the use of surfactants in body wash cosmetics is their potential to cause skin irritations. Surfactants can bind with proteins, remove lipids from the epidermal surface, contribute to the disorganization of liquid crystal structures in the intercellular lipids, and interact with living skin cells. These processes can lead to skin irritations and allergic reactions, and impair the epidermal barrier function. The present study is an attempt to assess the effect of polymers and hydrolysed proteins present in the formulations of model body wash cosmetics on product properties. Special attention was given to the safety of use of this product type. The study examined three macromolecules: polyvinylpyrrolidone (PVP), hydrolysed wheat protein (HWP) and polyvinylpyrrolidone/hydrolysed wheat protein crosspolymer (PVP/HWP). The addition of the substances under study was found to improve the foaming properties of body wash cosmetics, increase their stability during storage, and contribute significantly to an improvement in the safety of product use by reducing the irritant potential. The strongest ability to reduce the skin irritation potential was determined for the formula enriched with the PVP/HWP crosspolymer. Copyright © 2015 Elsevier B.V. All rights reserved.

Retroactive Maintains Cuticle Integrity by Promoting the Trafficking of Knickkopf into the Procuticle of Tribolium castaneum

PubMed Central

Chaudhari, Sujata S.; Arakane, Yasuyuki; Specht, Charles A.; Moussian, Bernard; Kramer, Karl J.; Muthukrishnan, Subbaratnam; Beeman, Richard W.

2013-01-01

Molting, or the replacement of the old exoskeleton with a new cuticle, is a complex developmental process that all insects must undergo to allow unhindered growth and development. Prior to each molt, the developing new cuticle must resist the actions of potent chitinolytic enzymes that degrade the overlying old cuticle. We recently disproved the classical dogma that a physical barrier prevents chitinases from accessing the new cuticle and showed that the chitin-binding protein Knickkopf (Knk) protects the new cuticle from degradation. Here we demonstrate that, in Tribolium castaneum, the protein Retroactive (TcRtv) is an essential mediator of this protective effect of Knk. TcRtv localizes within epidermal cells and specifically confers protection to the new cuticle against chitinases by facilitating the trafficking of TcKnk into the procuticle. Down-regulation of TcRtv resulted in entrapment of TcKnk within the epidermal cells and caused molting defects and lethality in all stages of insect growth, consistent with the loss of TcKnk function. Given the ubiquity of Rtv and Knk orthologs in arthropods, we propose that this mechanism of new cuticle protection is conserved throughout the phylum. PMID:23382702

Retroactive maintains cuticle integrity by promoting the trafficking of Knickkopf into the procuticle of Tribolium castaneum.

PubMed

Chaudhari, Sujata S; Arakane, Yasuyuki; Specht, Charles A; Moussian, Bernard; Kramer, Karl J; Muthukrishnan, Subbaratnam; Beeman, Richard W

2013-01-01

Molting, or the replacement of the old exoskeleton with a new cuticle, is a complex developmental process that all insects must undergo to allow unhindered growth and development. Prior to each molt, the developing new cuticle must resist the actions of potent chitinolytic enzymes that degrade the overlying old cuticle. We recently disproved the classical dogma that a physical barrier prevents chitinases from accessing the new cuticle and showed that the chitin-binding protein Knickkopf (Knk) protects the new cuticle from degradation. Here we demonstrate that, in Tribolium castaneum, the protein Retroactive (TcRtv) is an essential mediator of this protective effect of Knk. TcRtv localizes within epidermal cells and specifically confers protection to the new cuticle against chitinases by facilitating the trafficking of TcKnk into the procuticle. Down-regulation of TcRtv resulted in entrapment of TcKnk within the epidermal cells and caused molting defects and lethality in all stages of insect growth, consistent with the loss of TcKnk function. Given the ubiquity of Rtv and Knk orthologs in arthropods, we propose that this mechanism of new cuticle protection is conserved throughout the phylum.

Deletion of Late Cornified Envelope 3B and 3C genes is not associated with atopic dermatitis.

PubMed

Bergboer, Judith G M; Zeeuwen, Patrick L J M; Irvine, Alan D; Weidinger, Stephan; Giardina, Emiliano; Novelli, Giuseppe; Den Heijer, Martin; Rodriguez, Elke; Illig, Thomas; Riveira-Munoz, Eva; Campbell, Linda E; Tyson, Jess; Dannhauser, Emma N; O'Regan, Gráinne M; Galli, Elena; Klopp, Norman; Koppelman, Gerard H; Novak, Natalija; Estivill, Xavier; McLean, W H Irwin; Postma, Dirkje S; Armour, John A L; Schalkwijk, Joost

2010-08-01

Atopic dermatitis (AD) and psoriasis are common skin diseases characterized by cutaneous inflammation and disturbed epidermal differentiation. Genome-wide analyses have shown overlapping susceptibility loci, such as the epidermal differentiation complex on chromosome 1q21. Recently, a deletion on 1q21 (LCE3C_LCE3B-del), comprising LCE3B and LCE3C, two members of the late cornified envelope (LCE) gene cluster, was found to be associated with psoriasis. Although the mechanistic role of LCE proteins in psoriasis has not been identified, these proteins are putatively involved in skin barrier formation and repair. Considering the potential genetic overlap between the two diseases and the recent finding that mutations in the skin barrier protein filaggrin are associated with AD, we investigated a possible association between LCE3C_LCE3B-del and AD. Evaluation of four different cohorts of European ancestry, containing a total of 1075 AD patients and 1658 controls, did not provide evidence for such an association. Subgroup analysis did not reveal an association with concomitant asthma. Our data suggest that the potential roles of skin barrier defects in the pathogenesis of AD and psoriasis are based on distinct genetic causes.

Delphinidin, a dietary antioxidant, induces human epidermal keratinocyte differentiation but not apoptosis: studies in submerged and three-dimensional epidermal equivalent models.

PubMed

Chamcheu, Jean Christopher; Afaq, Farrukh; Syed, Deeba N; Siddiqui, Imtiaz A; Adhami, Vaqar M; Khan, Naghma; Singh, Sohinderjit; Boylan, Brendan T; Wood, Gary S; Mukhtar, Hasan

2013-05-01

Delphinidin (Del), [3,5,7,3'-,4'-,5'-hexahydroxyflavylium], an anthocyanidin and a potent antioxidant abundantly found in pigmented fruits and vegetables exhibits proapoptotic effects in many cancer cells. Here, we determined the effect of Del on growth, apoptosis and differentiation of normal human epidermal keratinocytes (NHEKs) in vitro in submerged cultures and examined its effects in a three-dimensional (3D) epidermal equivalent (EE) model that permits complete differentiation reminiscent of in vivo skin. Treatment of NHEKs with Del (10-40 μm; 24-48 h) significantly enhanced keratinocyte differentiation. In Del-treated cells, there was marked increase in human involucrin (hINV) promoter activity with simultaneous increase in the mRNA and protein expressions of involucrin and other epidermal differentiation markers including procaspase-14 and transglutaminase-1 (TGM1), but without any effect on TGM2. Del treatment of NHEKs was associated with minimal decrease in cell viability, which was not associated with apoptosis as evident by lack of modulation of caspases, apoptosis-related proteins including Bcl-2 family of proteins and poly(ADP-ribose) polymerase cleavage. To establish the in vivo relevance of our observations in submerged cultures, we then validated these effects in a 3D EE model, where Del was found to significantly enhance cornification and increase the protein expression of cornification markers including caspase-14 and keratin 1. For the first time, we show that Del induces epidermal differentiation using an experimental system that closely mimics in vivo human skin. These observations suggest that Del could be a useful agent for dermatoses associated with epidermal barrier defects including aberrant keratinization, hyperproliferation or inflammation observed in skin diseases like psoriasis and ichthyoses. © 2013 John Wiley & Sons A/S.

Highly abundant defense proteins in human sweat as revealed by targeted proteomics and label-free quantification mass spectrometry.

PubMed

Csősz, É; Emri, G; Kalló, G; Tsaprailis, G; Tőzsér, J

2015-10-01

The healthy human skin with its effective antimicrobial defense system forms an efficient barrier against invading pathogens. There is evidence suggesting that the composition of this chemical barrier varies between diseases, making the easily collected sweat an ideal candidate for biomarker discoveries. Our aim was to provide information about the normal composition of the sweat, and to study the chemical barrier found at the surface of skin. Sweat samples from healthy individuals were collected during sauna bathing, and the global protein panel was analysed by label-free mass spectrometry. SRM-based targeted proteomic methods were designed and stable isotope labelled reference peptides were used for method validation. Ninety-five sweat proteins were identified, 20 of them were novel proteins. It was shown that dermcidin is the most abundant sweat protein, and along with apolipoprotein D, clusterin, prolactin-inducible protein and serum albumin, they make up 91% of secreted sweat proteins. The roles of these highly abundant proteins were reviewed; all of which have protective functions, highlighting the importance of sweat glands in composing the first line of innate immune defense system, and maintaining the epidermal barrier integrity. Our findings with regard to the proteins forming the chemical barrier of the skin as determined by label-free quantification and targeted proteomics methods are in accordance with previous studies, and can be further used as a starting point for non-invasive sweat biomarker research. © 2015 European Academy of Dermatology and Venereology.

Cytoplasmic poly (A)-binding protein critically regulates epidermal maintenance and turnover in the planarian Schmidtea mediterranea.

PubMed

Bansal, Dhiru; Kulkarni, Jahnavi; Nadahalli, Kavana; Lakshmanan, Vairavan; Krishna, Srikar; Sasidharan, Vidyanand; Geo, Jini; Dilipkumar, Shilpa; Pasricha, Renu; Gulyani, Akash; Raghavan, Srikala; Palakodeti, Dasaradhi

2017-09-01

Identifying key cellular events that facilitate stem cell function and tissue organization is crucial for understanding the process of regeneration. Planarians are powerful model system to study regeneration and stem cell (neoblast) function. Here, using planaria, we show that the initial events of regeneration, such as epithelialization and epidermal organization are critically regulated by a novel cytoplasmic poly A-binding protein, SMED-PABPC2. Knockdown of smed-pabpc2 leads to defects in epidermal lineage specification, disorganization of epidermis and ECM, and deregulated wound healing, resulting in the selective failure of neoblast proliferation near the wound region. Polysome profiling suggests that epidermal lineage transcripts, including zfp-1 , are translationally regulated by SMED-PABPC2 . Together, our results uncover a novel role for SMED-PABPC2 in the maintenance of epidermal and ECM integrity, critical for wound healing and subsequent processes for regeneration. © 2017. Published by The Company of Biologists Ltd.

Cytoplasmic poly (A)-binding protein critically regulates epidermal maintenance and turnover in the planarian Schmidtea mediterranea

PubMed Central

Bansal, Dhiru; Kulkarni, Jahnavi; Nadahalli, Kavana; Lakshmanan, Vairavan; Krishna, Srikar; Sasidharan, Vidyanand; Dilipkumar, Shilpa; Gulyani, Akash; Raghavan, Srikala

2017-01-01

Identifying key cellular events that facilitate stem cell function and tissue organization is crucial for understanding the process of regeneration. Planarians are powerful model system to study regeneration and stem cell (neoblast) function. Here, using planaria, we show that the initial events of regeneration, such as epithelialization and epidermal organization are critically regulated by a novel cytoplasmic poly A-binding protein, SMED-PABPC2. Knockdown of smed-pabpc2 leads to defects in epidermal lineage specification, disorganization of epidermis and ECM, and deregulated wound healing, resulting in the selective failure of neoblast proliferation near the wound region. Polysome profiling suggests that epidermal lineage transcripts, including zfp-1, are translationally regulated by SMED-PABPC2. Together, our results uncover a novel role for SMED-PABPC2 in the maintenance of epidermal and ECM integrity, critical for wound healing and subsequent processes for regeneration. PMID:28807897

Novel mechanisms for the vitamin D receptor (VDR) in the skin and in skin cancer.

PubMed

Bikle, Daniel D; Oda, Yuko; Tu, Chia-Ling; Jiang, Yan

2015-04-01

The VDR acting with or without its principal ligand 1,25(OH)2D regulates two central processes in the skin, interfollicular epidermal (IFE) differentiation and hair follicle cycling (HFC). Calcium is an important co-regulator with 1,25(OH)2D at least of epidermal differentiation. Knockout of the calcium sensing receptor (CaSR) in addition to VDR accelerates the development of skin cancer in mice on a low calcium diet. Coactivators such as mediator 1 (aka DRIP205) and steroid receptor coactivator 3 (SRC3) regulate VDR function at different stages of the differentiation process, with Med 1 essential for hair follicle differentiation and early stages of epidermal differentiation and proliferation and SRC3 essential for the latter stages of differentiation including formation of the permeability barrier and innate immunity. The corepressor of VDR, hairless (HR), is essential for hair follicle cycling, although its effect on epidermal differentiation in vivo is minimal. In its regulation of HFC and IFE VDR controls two pathways-wnt/β-catenin and sonic hedgehog (SHH). In the absence of VDR these pathways are overexpressed leading to tumor formation. Whereas, VDR binding to β-catenin may block its activation of TCF/LEF1 sites, β-catenin binding to VDR may enhance its activation of VDREs. 1,25(OH)2D promotes but may not be required for these interactions. Suppression of SHH expression by VDR, on the other hand, requires 1,25(OH)2D. The major point of emphasis is that the role of VDR in the skin involves a number of novel mechanisms, both 1,25(OH)2D dependent and independent, that when disrupted interfere with IFE differentiation and HFC, predisposing to cancer formation. This article is part of a Special Issue entitled '17th Vitamin D Workshop'. Copyright © 2014 Elsevier Ltd. All rights reserved.

TGM5 mutations impact epidermal differentiation in acral peeling skin syndrome.

PubMed

Pigors, Manuela; Kiritsi, Dimitra; Cobzaru, Cristina; Schwieger-Briel, Agnes; Suárez, Jose; Faletra, Flavio; Aho, Heikki; Mäkelä, Leeni; Kern, Johannes S; Bruckner-Tuderman, Leena; Has, Cristina

2012-10-01

Acral peeling skin syndrome (APSS) is an autosomal recessive skin disorder characterized by acral blistering and peeling of the outermost layers of the epidermis. It is caused by mutations in the gene for transglutaminase 5, TGM5. Here, we report on clinical and molecular findings in 11 patients and extend the TGM5 mutation database by four, to our knowledge, previously unreported mutations: p.M1T, p.L41P, p.L214CfsX15, and p.S604IfsX9. The recurrent mutation p.G113C was found in 9 patients, but also in 3 of 100 control individuals in a heterozygous state, indicating that APSS might be more widespread than hitherto expected. Using quantitative real-time PCR, immunoblotting, and immunofluorescence analysis, we demonstrate that expression and distribution of several epidermal differentiation markers and corneodesmosin (CDSN) is altered in APSS keratinocytes and skin. Although the expression of transglutaminases 1 and 3 was not changed, we found an upregulation of keratin 1, keratin 10, involucrin, loricrin, and CDSN, probably as compensatory mechanisms for stabilization of the epidermal barrier. Our results give insights into the consequences of TGM5 mutations on terminal epidermal differentiation.

Epidermal ablation of Dlx3 is linked to IL-17–associated skin inflammation

PubMed Central

Hwang, Joonsung; Kita, Ryosuke; Kwon, Hyouk-Soo; Choi, Eung Ho; Lee, Seung Hun; Udey, Mark C.; Morasso, Maria I.

2011-01-01

In an effort to understand the role of Distal-less 3 (Dlx3) in cutaneous biology and pathophysiology, we generated and characterized a mouse model with epidermal ablation of Dlx3. K14cre;Dlx3Kin/f mice exhibited epidermal hyperproliferation and abnormal differentiation of keratinocytes. Results from subsequent analyses revealed cutaneous inflammation that featured accumulation of IL-17–producing CD4+ T, CD8+ T, and γδ T cells in the skin and lymph nodes of K14cre;Dlx3Kin/f mice. The gene expression signature of K14cre;Dlx3Kin/f skin shared features with lesional psoriatic skin, and Dlx3 expression was markedly and selectively decreased in psoriatic skin. Interestingly, cultured Dlx3 null keratinocytes triggered cytokine production that is potentially linked to inflammatory responses in K14cre;Dlx3Kin/f mice. Thus, Dlx3 ablation in epidermis is linked to altered epidermal differentiation, barrier development, and IL-17–associated skin inflammation. This model provides a platform that will allow the systematic exploration of the contributions of keratinocytes to cutaneous inflammation. PMID:21709238

[The extraneuronal cholinergic system of the skin. Basic facts and clinical relevance].

PubMed

Kurzen, H

2004-05-01

Acetylcholine (ACh) is a prototypical neurotransmitter that has recently been recognized to occur extraneuronally in a large variety of cells. ACh and its nicotinic and muscarinic receptors are produced in the epidermis and in the adnexal structures of the skin in a highly complicated pattern. They are also produced in melanocytes, fibroblasts, endothelial cells and immune cells. Through autocrine, paracrine and endocrine mechanisms, the cholinergic system is involved in the basic functions of the skin, such as keratinocyte differentiation, epidermal barrier formation, sweating, sebum production, blood circulation, angiogenesis and a variety of immune reactions. Hence diseases like acne vulgaris, vitiligo, psoriasis, pemphigus vulgaris and atopic dermatitis may be influenced. The exploration of the extraneuronal cholinergic system of the skin has only just begun.

Differentiated epidermal cells regain the ability to regenerate a skin equivalent by increasing the level of β-catenin in the cells.

PubMed

Zhao, Zhili; Zhang, Cuiping; Fu, Xiaobing; Yang, Rongya; Peng, Chen; Gu, Tingmin; Sui, Zhifu; Wang, Congmin; Liu, Chang

2012-01-01

Epidermal stem cells are of major importance for skin regeneration and tissue engineering, but differentiated epidermal cells lost their proliferative capacity and are no longer able to regenerate a skin equivalent. Here, we investigated the role of β-catenin in regulating regenerative functions of differentiated epidermal cells. Lithium chloride and a highly specific glycogen synthase kinase (GSK)-3β inhibitor were applied to induce the expression of β-catenin in differentiated epidermal cells. After a 6-day induction, the large flat-shaped cells with a small nuclear-cytoplasmic ratio had changed into small round-shaped cells with a large nuclear-cytoplasmic ratio. Phenotypic assays showed a remarkably higher expression of CK19, β(1)-integrin, Oct4 and Nanog in induced cells than in the control group (p < 0.01). In addition, the results of growth and functional investigations demonstrated that the induced epidermal cells exhibited a high colony-forming ability, a long-term proliferative potential and the ability to regenerate a skin equivalent, which were regarded as the most important features of epidermal stem cells. These results suggest that the activation of β-catenin favors the reversion or dedifferentiation of differentiated epidermal cells to an immature or a less differentiated state. This study may also offer a new approach to yield enough epidermal stem cells for skin regeneration and tissue engineering. Copyright © 2012 S. Karger AG, Basel.

Epidermal Hydration Is Improved by Enhanced Ceramide Metabolism in Aged C57BL/6J Mice After Dietary Supplementation of Royal Jelly.

PubMed

Jeon, Sanghun; Cho, Yunhi

2015-09-01

Epidermal hydration is maintained by the epidermal lipid barrier, of which ceramide (Cer) is the major constituent. We examined the dietary effect of royal jelly (RJ) on epidermal hydration in aged mice. Altered Cer metabolism was further determined by measuring epidermal levels of individual Cer, glucosylceramide (GC), and sphingomyelin (SM) species, and of Cer-metabolizing enzymes. Aged C57BL/6J mice were fed a control diet (group AGED) or diets with 1% RJ harvested from two different areas (groups AGED+RJ1:AGED + RJ2) for 16 weeks. Aged C57BL/6J mice with no dietary intervention (the control group: group C) represented the onset of aging. In group AGED, epidermal levels of hydration, Cer1/2/5/6/7, GC-A/B/C/D, SM1/2/3, and β-glucocerebrosidase (GCase) protein, an enzyme of GC hydrolysis for Cer generation, were lower than in group C; these levels, as well as those of Cer3/4 and acidic sphingomyelinase (aSMase) protein, an enzyme of SM hydrolysis for Cer generation, were higher in group AGED + RJ1 than in group AGED. Despite increases in GC-B, SM1/2/3, and serine palmitoyltransferase2 protein, an enzyme of de novo Cer synthesis, in group AGED + RJ2 to levels higher than in group AGED, epidermal levels of hydration, Cer1-7, GC-A/C/D, GCase, and aSMase proteins were similar in these two groups. Expression of GCase and aSMase mRNAs, and of Cer synthase3 and ceramidase proteins, enzymes of de novo Cer synthesis and degradation, did not differ among groups. Dietary RJ1 improved epidermal hydration by enhancing Cer metabolism with increased levels of all Cer, GC, and SM species, and of GCase and aSMase proteins.

“Panta rhei”

PubMed Central

Moch, Marcin; Kölsch, Anne; Windoffer, Reinhard

2011-01-01

The filamentous cytoskeletal systems fulfil seemingly incompatible functions by maintaining a stable scaffolding to ensure tissue integrity and simultaneously facilitating rapid adaptation to intracellular processes and environmental stimuli. This paradox is particularly obvious for the abundant keratin intermediate filaments in epithelial tissues. The epidermal keratin cytoskeleton, for example, supports the protective and selective barrier function of the skin while enabling rapid growth and remodelling in response to physical, chemical and microbial challenges. We propose that these dynamic properties are linked to the perpetual re-cycling of keratin intermediate filaments that we observe in cultured cells. This cycle of assembly and disassembly is independent of protein biosynthesis and consists of distinct, temporally and spatially defined steps. In this way, the keratin cytoskeleton remains in constant motion but stays intact and is also able to restructure rapidly in response to specific regulatory cues as is needed, e.g., during division, differentiation and wound healing. PMID:21866261

"Panta rhei": Perpetual cycling of the keratin cytoskeleton.

PubMed

Leube, Rudolf E; Moch, Marcin; Kölsch, Anne; Windoffer, Reinhard

2011-01-01

The filamentous cytoskeletal systems fulfil seemingly incompatible functions by maintaining a stable scaffolding to ensure tissue integrity and simultaneously facilitating rapid adaptation to intracellular processes and environmental stimuli. This paradox is particularly obvious for the abundant keratin intermediate filaments in epithelial tissues. The epidermal keratin cytoskeleton, for example, supports the protective and selective barrier function of the skin while enabling rapid growth and remodelling in response to physical, chemical and microbial challenges. We propose that these dynamic properties are linked to the perpetual re-cycling of keratin intermediate filaments that we observe in cultured cells. This cycle of assembly and disassembly is independent of protein biosynthesis and consists of distinct, temporally and spatially defined steps. In this way, the keratin cytoskeleton remains in constant motion but stays intact and is also able to restructure rapidly in response to specific regulatory cues as is needed, e.g., during division, differentiation and wound healing.

Death penalty for keratinocytes: apoptosis versus cornification.

PubMed

Lippens, S; Denecker, G; Ovaere, P; Vandenabeele, P; Declercq, W

2005-11-01

Homeostasis implies a balance between cell growth and cell death. This balance is essential for the development and maintenance of multicellular organisms. Homeostasis is controlled by several mechanisms including apoptosis, a process by which cells condemned to death are completely eliminated. However, in some cases, total destruction and removal of dead cells is not desirable, as when they fulfil a specific function such as formation of the skin barrier provided by corneocytes, also known as terminally differentiated keratinocytes. In this case, programmed cell death results in accumulation of functional cell corpses. Previously, this process has been associated with apoptotic cell death. In this overview, we discuss differences and similarities in the molecular regulation of epidermal programmed cell death and apoptosis. We conclude that despite earlier confusion, apoptosis and cornification occur through distinct molecular pathways, and that possibly antiapoptotic mechanisms are implicated in the terminal differentiation of keratinocytes.

Signalling in the epidermis: the E2F cell cycle regulatory pathway in epidermal morphogenesis, regeneration and transformation.

PubMed

Ivanova, Iordanka A; D'Souza, Sudhir J A; Dagnino, Lina

2005-01-01

The epidermis is the outermost layer in the skin, and it is the first line of defence against the environment. The epidermis also provides a barrier against loss of fluids and electrolytes, which is crucial for life. Essential in the maintenance of this tissue is its ability to continually self-renew and regenerate after injury. These two characteristics are critically dependent on the ability of the principal epidermal cell type, the keratinocyte, to proliferate and to respond to differentiation cues. Indeed, the epidermis is a multilayered tissue composed of keratinocyte stem cells and their differentiated progeny. Central for the control of cell proliferation is the E2F transcription factor regulatory network. This signaling network also includes cyclins, cdk, cdk inhibitors and the retinoblastoma (pRb) family of proteins. The biological importance of the E2F/pRb pathway is emphasized by the fact that a majority of human tumours exhibit alterations that disrupt the ability of pRb proteins to inhibit E2F, leading to permanent activation of the latter. Further, E2F is essential for normal epidermal regeneration after injury. Other member of the E2F signaling pathway are also involved in epidermal development and pathophysiology. Thus, whereas the pRb family of proteins is essential for epidermal morphogenesis, abnormal regulation of cyclins and E2F proteins results in tumorgenesis in this tissue. In this review, we discuss the role of each member of this important growth regulatory network in epidermal formation, homeostasis and carcinogenesis.

Signalling In The Epidermis: The E2f Cell Cycle Regulatory Pathway In Epidermal Morphogenesis, Regeneration And Transformation

PubMed Central

2005-01-01

The epidermis is the outermost layer in the skin, and it is the first line of defence against the environment. The epidermis also provides a barrier against loss of fluids and electrolytes, which is crucial for life. Essential in the maintenance of this tissue is its ability to continually self-renew and regenerate after injury. These two characteristics are critically dependent on the ability of the principal epidermal cell type, the keratinocyte, to proliferate and to respond to differentiation cues. Indeed, the epidermis is a multilayered tissue composed of keratinocyte stem cells and their differentiated progeny. Central for the control of cell proliferation is the E2F transcription factor regulatory network. This signaling network also includes cyclins, cdk, cdk inhibitors and the retinoblastoma (pRb) family of proteins. The biological importance of the E2F/pRb pathway is emphasized by the fact that a majority of human tumours exhibit alterations that disrupt the ability of pRb proteins to inhibit E2F, leading to permanent activation of the latter. Further, E2F is essential for normal epidermal regeneration after injury. Other member of the E2F signaling pathway are also involved in epidermal development and pathophysiology. Thus, whereas the pRb family of proteins is essential for epidermal morphogenesis, abnormal regulation of cyclins and E2F proteins results in tumorgenesis in this tissue. In this review, we discuss the role of each member of this important growth regulatory network in epidermal formation, homeostasis and carcinogenesis. PMID:15951853

Using scale and feather traits for module construction provides a functional approach to chicken epidermal development.

PubMed

Bao, Weier; Greenwold, Matthew J; Sawyer, Roger H

2017-11-01

Gene co-expression network analysis has been a research method widely used in systematically exploring gene function and interaction. Using the Weighted Gene Co-expression Network Analysis (WGCNA) approach to construct a gene co-expression network using data from a customized 44K microarray transcriptome of chicken epidermal embryogenesis, we have identified two distinct modules that are highly correlated with scale or feather development traits. Signaling pathways related to feather development were enriched in the traditional KEGG pathway analysis and functional terms relating specifically to embryonic epidermal development were also enriched in the Gene Ontology analysis. Significant enrichment annotations were discovered from customized enrichment tools such as Modular Single-Set Enrichment Test (MSET) and Medical Subject Headings (MeSH). Hub genes in both trait-correlated modules showed strong specific functional enrichment toward epidermal development. Also, regulatory elements, such as transcription factors and miRNAs, were targeted in the significant enrichment result. This work highlights the advantage of this methodology for functional prediction of genes not previously associated with scale- and feather trait-related modules.

A functional cutin matrix is required for plant protection against water loss

PubMed Central

Ma, Jian Feng; Li, Chao; Yamaji, Naoki; Nevo, Eviatar

2011-01-01

The plant cuticle, a cutin matrix embedded with and covered by wax, seals the aerial organ's surface to protect the plant against uncontrolled water loss. The cutin matrix is essential for the cuticle to function as a barrier to water loss. Recently, we identified from wild barley a drought supersensitive mutant, eibi1, which is caused by a defective cutin matrix as the result of the loss of function of HvABCG31, an ABCG full transporter. Here, we report that eibi1 epidermal cells contain lipid-like droplets, which are supposed to consist of cutin monomers that have not been transported out of the cells. The eibi1 cuticle is fragile due to a defective cutin matrix. The rice ortholog of the EIBI1 gene has a similar pattern of expression, young shoot but not flag leaf blade, as the barley gene. The model of the function of Eibi1 is discussed. The HvABCG31 full transporter functions in the export of cutin components and contributed to land plant colonization, hence also to terrestrial life evolution. PMID:22019635

A functional cutin matrix is required for plant protection against water loss.

PubMed

Chen, Guoxiong; Komatsuda, Takao; Ma, Jian Feng; Li, Chao; Yamaji, Naoki; Nevo, Eviatar

2011-09-01

The plant cuticle, a cutin matrix embedded with and covered by wax, seals the aerial organ's surface to protect the plant against uncontrolled water loss. The cutin matrix is essential for the cuticle to function as a barrier to water loss. Recently, we identified from wild barley a drought supersensitive mutant, eibi1, which is caused by a defective cutin matrix as the result of the loss of function of HvABCG31, an ABCG full transporter. Here, we report that eibi1 epidermal cells contain lipid-like droplets, which are supposed to consist of cutin monomers that have not been transported out of the cells. The eibi1 cuticle is fragile due to a defective cutin matrix. The rice ortholog of the EIBI1 gene has a similar pattern of expression, young shoot but not flag leaf blade, as the barley gene. The model of the function of Eibi1 is discussed. The HvABCG31 full transporter functions in the export of cutin components and contributed to land plant colonization, hence also to terrestrial life evolution.

Bioengineering a Human Plasma-Based Epidermal Substitute With Efficient Grafting Capacity and High Content in Clonogenic Cells

PubMed Central

Alexaline, Maia M.; Trouillas, Marina; Nivet, Muriel; Bourreau, Emilie; Leclerc, Thomas; Duhamel, Patrick; Martin, Michele T.; Doucet, Christelle; Fortunel, Nicolas O.

2015-01-01

Cultured epithelial autografts (CEAs) produced from a small, healthy skin biopsy represent a lifesaving surgical technique in cases of full-thickness skin burn covering >50% of total body surface area. CEAs also present numerous drawbacks, among them the use of animal proteins and cells, the high fragility of keratinocyte sheets, and the immaturity of the dermal-epidermal junction, leading to heavy cosmetic and functional sequelae. To overcome these weaknesses, we developed a human plasma-based epidermal substitute (hPBES) for epidermal coverage in cases of massive burn, as an alternative to traditional CEA, and set up critical quality controls for preclinical and clinical studies. In this study, phenotypical analyses in conjunction with functional assays (clonal analysis, long-term culture, or in vivo graft) showed that our new substitute fulfills the biological requirements for epidermal regeneration. hPBES keratinocytes showed high potential for cell proliferation and subsequent differentiation similar to healthy skin compared with a well-known reference material, as ascertained by a combination of quality controls. This work highlights the importance of integrating relevant multiparameter quality controls into the bioengineering of new skin substitutes before they reach clinical development. Significance This work involves the development of a new bioengineered epidermal substitute with pertinent functional quality controls. The novelty of this work is based on this quality approach. PMID:25848122

Bioengineering a human plasma-based epidermal substitute with efficient grafting capacity and high content in clonogenic cells.

PubMed

Alexaline, Maia M; Trouillas, Marina; Nivet, Muriel; Bourreau, Emilie; Leclerc, Thomas; Duhamel, Patrick; Martin, Michele T; Doucet, Christelle; Fortunel, Nicolas O; Lataillade, Jean-Jacques

2015-06-01

Cultured epithelial autografts (CEAs) produced from a small, healthy skin biopsy represent a lifesaving surgical technique in cases of full-thickness skin burn covering >50% of total body surface area. CEAs also present numerous drawbacks, among them the use of animal proteins and cells, the high fragility of keratinocyte sheets, and the immaturity of the dermal-epidermal junction, leading to heavy cosmetic and functional sequelae. To overcome these weaknesses, we developed a human plasma-based epidermal substitute (hPBES) for epidermal coverage in cases of massive burn, as an alternative to traditional CEA, and set up critical quality controls for preclinical and clinical studies. In this study, phenotypical analyses in conjunction with functional assays (clonal analysis, long-term culture, or in vivo graft) showed that our new substitute fulfills the biological requirements for epidermal regeneration. hPBES keratinocytes showed high potential for cell proliferation and subsequent differentiation similar to healthy skin compared with a well-known reference material, as ascertained by a combination of quality controls. This work highlights the importance of integrating relevant multiparameter quality controls into the bioengineering of new skin substitutes before they reach clinical development. This work involves the development of a new bioengineered epidermal substitute with pertinent functional quality controls. The novelty of this work is based on this quality approach. ©AlphaMed Press.

Newborn infant skin: physiology, development, and care.

PubMed

Visscher, Marty O; Adam, Ralf; Brink, Susanna; Odio, Mauricio

2015-01-01

Infant skin is critical to the newborn child's transition from the womb environment to the journey to self-sufficiency. This review provides an integrative perspective on the skin development in full term and premature infants. There is a particular focus on the role of vernix caseosa and on the implications of skin development for epidermal penetration of exogenous compounds. Healthy full-term newborn skin is well-developed and functional at birth, with a thick epidermis and well-formed stratum corneum (SC) layers. Transepidermal water loss is very low at birth, equal to, or lower than adults, indicating a highly effective skin barrier. Vernix facilitates SC development in full-term infants through a variety of mechanisms including physical protection from amniotic fluid and enzymes, antimicrobial effects, skin surface pH lowering, provision of lipids, and hydration. Premature infants, particularly those of very low birth weight, have a poor skin barrier with few cornified layers and deficient dermal proteins. They are at increased risk for skin damage, increased permeability to exogenous agents and infection. The SC barrier develops rapidly after birth but complete maturation requires weeks to months. The best methods for caring for infant skin, particularly in the diaper region, are described and related to these developmental changes. Copyright © 2015 Elsevier Inc. All rights reserved.

Sebaceous Gland, Hair Shaft, and Epidermal Barrier Abnormalities in Keratosis Pilaris with and without Filaggrin Deficiency

PubMed Central

Gruber, Robert; Sugarman, Jeffrey L.; Crumrine, Debra; Hupe, Melanie; Mauro, Theodora M.; Mauldin, Elizabeth A.; Thyssen, Jacob P.; Brandner, Johanna M.; Hennies, Hans-Christian; Schmuth, Matthias; Elias, Peter M.

2016-01-01

Although keratosis pilaris (KP) is common, its etiopathogenesis remains unknown. KP is associated clinically with ichthyosis vulgaris and atopic dermatitis and molecular genetically with filaggrin-null mutations. In 20 KP patients and 20 matched controls, we assessed the filaggrin and claudin 1 genotypes, the phenotypes by dermatoscopy, and the morphology by light and transmission electron microscopy. Thirty-five percent of KP patients displayed filaggrin mutations, demonstrating that filaggrin mutations only partially account for the KP phenotype. Major histologic and dermatoscopic findings of KP were hyperkeratosis, hypergranulosis, mild T helper cell type 1-dominant lymphocytic inflammation, plugging of follicular orifices, striking absence of sebaceous glands, and hair shaft abnormalities in KP lesions but not in unaffected skin sites. Changes in barrier function and abnormal paracellular permeability were found in both interfollicular and follicular stratum corneum of lesional KP, which correlated ultrastructurally with impaired extracellular lamellar bilayer maturation and organization. All these features were independent of filaggrin genotype. Moreover, ultrastructure of corneodesmosomes and tight junctions appeared normal, immunohistochemistry for claudin 1 showed no reduction in protein amounts, and molecular analysis of claudin 1 was unremarkable. Our findings suggest that absence of sebaceous glands is an early step in KP pathogenesis, resulting in downstream hair shaft and epithelial barrier abnormalities. PMID:25660180

Evaluation of a cyanoacrylate dressing to manage peristomal skin alterations under ostomy skin barrier wafers.

PubMed

Milne, Catherine T; Saucier, Darlene; Trevellini, Chenel; Smith, Juliet

2011-01-01

Peristomal skin alterations under ostomy barrier wafers are a commonly reported problem. While a number of interventions to manage this issue have been reported, the use of a topically applied cyanoacrylate has received little attention. This case series describes the use of a topical cyanoacrylate for the management of peristomal skin alterations in persons living with an ostomy. Using a convenience sample, the topical cyanoacrylate dressing was applied to 11 patients with peristomal skin disruption under ostomy wafers in acute care and outpatient settings. The causes of barrier function interruption were also addressed to enhance outcomes. Patients were assessed for wound discomfort using a Likert Scale, time to healing, and number of appliance changes. Patient satisfaction was also examined. Average reported discomfort levels were 9.5 out of 10 at the initial peristomal irritation assessment visit decreased to 3.5 at the first wafer change and were absent by the second wafer change. Wafers had increasing wear time between changes in both settings with acute care patients responding faster. Epidermal resurfacing occurred within 10.2 days in outpatients and within 7 days in acute care patients. Because of the skin sealant action of this dressing, immediate adherence of the wafer was reported at all pouch changes.

Increased Bacterial Load and Expression of Antimicrobial Peptides in Skin of Barrier-Deficient Mice with Reduced Cancer Susceptibility.

PubMed

Natsuga, Ken; Cipolat, Sara; Watt, Fiona M

2016-01-01

Mice lacking three epidermal barrier proteins-envoplakin, periplakin, and involucrin (EPI-/- mice)-have a defective cornified layer, reduced epidermal γδ T cells, and increased dermal CD4(+) T cells. They are also resistant to developing skin tumors. The tumor-protective mechanism involves signaling between Rae-1 expressing keratinocytes and the natural killer group 2D receptor on immune cells, which also plays a role in host defenses against infection. Given the emerging link between bacteria and cancer, we investigated whether EPI-/- mice have an altered skin microbiota. The bacterial phyla were similar in wild-type and EPI-/- skin. However, bacteria were threefold more abundant in EPI-/- skin and penetrated deeper into the epidermis. The major epithelial defense mechanism against bacteria is production of antimicrobial proteins (AMPs). EPI-/- skin exhibited enhanced expression of antimicrobial peptides. However, reducing the bacterial load by antibiotic treatment or breeding mice under specific pathogen-free conditions did not reduce AMP expression or alleviate the abnormalities in T-cell populations. We conclude that the atopic characteristics of EPI-/- skin are a consequence of the defective barrier rather than a response to the increased bacterial load. It is therefore unlikely that the increase in skin microbiota contributes directly to the observed cancer resistance. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

The skin microbiome: impact of modern environments on skin ecology, barrier integrity, and systemic immune programming.

PubMed

Prescott, Susan L; Larcombe, Danica-Lea; Logan, Alan C; West, Christina; Burks, Wesley; Caraballo, Luis; Levin, Michael; Etten, Eddie Van; Horwitz, Pierre; Kozyrskyj, Anita; Campbell, Dianne E

2017-01-01

Skin barrier structure and function is essential to human health. Hitherto unrecognized functions of epidermal keratinocytes show that the skin plays an important role in adapting whole-body physiology to changing environments, including the capacity to produce a wide variety of hormones, neurotransmitters and cytokine that can potentially influence whole-body states, and quite possibly, even emotions. Skin microbiota play an integral role in the maturation and homeostatic regulation of keratinocytes and host immune networks with systemic implications. As our primary interface with the external environment, the biodiversity of skin habitats is heavily influenced by the biodiversity of the ecosystems in which we reside. Thus, factors which alter the establishment and health of the skin microbiome have the potential to predispose to not only cutaneous disease, but also other inflammatory non-communicable diseases (NCDs). Indeed, disturbances of the stratum corneum have been noted in allergic diseases (eczema and food allergy), psoriasis, rosacea, acne vulgaris and with the skin aging process. The built environment, global biodiversity losses and declining nature relatedness are contributing to erosion of diversity at a micro-ecological level, including our own microbial habitats. This emphasises the importance of ecological perspectives in overcoming the factors that drive dysbiosis and the risk of inflammatory diseases across the life course.

The role of filaggrin mutations during pregnancy and postpartum: atopic dermatitis and genital skin diseases.

PubMed

Bager, P; Wohlfahrt, J; Boyd, H; Thyssen, J P; Melbye, M

2016-05-01

Mutations in the epidermal filaggrin gene (FLG) are associated with skin barrier dysfunction (dry skin, less acidic skin, and fissured skin), and atopic dermatitis (AD) with a severe and persistent course. Because pregnancy and delivery further impairs normal skin barrier functions (immune suppression, mechanical stress), we studied the possible role of FLG mutations on the risk of AD flares, genital infections, and postpartum problems related to perineal trauma. FLG-genotyping was performed in a population-based sample of 1837 women interviewed in the 12th and 30th weeks of pregnancy and 6 months postpartum as part of the Danish National Birth Cohort study 1996-2002. We found that FLG mutations also influence pregnancy-related skin disease; thus, women with FLG mutations had an increased risk of AD flares during pregnancy (OR 10.5, 95% CI 3.6-30.5) and of enduring postpartum physical problems linked to perineal trauma during delivery (OR 11.1, 95% CI 1.1-107.7). © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Evidence for mesenchymal-like sub-populations within squamous cell carcinomas possessing chemoresistance and phenotypic plasticity.

PubMed

Basu, D; Nguyen, T-T K; Montone, K T; Zhang, G; Wang, L-P; Diehl, J A; Rustgi, A K; Lee, J T; Weinstein, G S; Herlyn, M

2010-07-22

Variable drug responses among malignant cells within individual tumors may represent a barrier to their eradication using chemotherapy. Carcinoma cells expressing mesenchymal markers resist conventional and epidermal growth factor receptor (EGFR)-targeted chemotherapy. In this study, we evaluated whether mesenchymal-like sub-populations within human squamous cell carcinomas (SCCs) with predominantly epithelial features contribute to overall therapy resistance. We identified a mesenchymal-like subset expressing low E-cadherin (Ecad-lo) and high vimentin within the upper aerodigestive tract SCCs. This subset was both isolated from the cell lines and was identified in xenografts and primary clinical specimens. The Ecad-lo subset contained more low-turnover cells, correlating with resistance to the conventional chemotherapeutic paclitaxel in vitro. Epidermal growth factor induced less stimulation of the mitogen-activated protein kinase and phosphatidylinositol-3-kinase pathways in Ecad-lo cells, which was likely due to lower EGFR expression in this subset and correlated with in vivo resistance to the EGFR-targeted antibody, cetuximab. The Ecad-lo and high E-cadherin subsets were dynamic in phenotype, showing the capacity to repopulate each other from single-cell clones. Taken together, these results provide evidence for a low-turnover, mesenchymal-like sub-population in SCCs with diminished EGFR pathway function and intrinsic resistance to conventional and EGFR-targeted chemotherapies.

Epidermal growth factor targeting of bacteriophage to the choroid plexus for gene delivery to the central nervous system via cerebrospinal fluid.

PubMed

Gonzalez, Ana Maria; Leadbeater, Wendy; Podvin, Sonia; Borboa, Alexandra; Burg, Michael; Sawada, Ritsuko; Rayner, James; Sims, Karen; Terasaki, Tetsuya; Johanson, Conrad; Stopa, Edward; Eliceiri, Brian; Baird, Andrew

2010-11-04

Because the choroid plexus normally controls the production and composition of cerebrospinal fluid and, as such, its many functions of the central nervous system, we investigated whether ligand-mediated targeting could deliver genes to its secretory epithelium. We show here that when bacteriophages are targeted with epidermal growth factor, they acquire the ability to enter choroid epithelial cells grown in vitro as cell cultures, ex vivo as tissue explants or in vivo by intracerebroventricular injection. The binding and internalization of these particles activate EGF receptors on targeted cells, and the dose- and time-dependent internalization of particles is inhibited by the presence of excess ligand. When the phage genome is further reengineered to contain like green fluorescent protein or firefly luciferase under control of the cytomegalovirus promoter, gene expression is detectable in the choroid plexus and ependymal epithelium by immunohistochemistry or by noninvasive imaging, respectively. Taken together, these data support the hypothesis that reengineered ligand-mediated gene delivery should be considered a viable strategy to increase the specificity of gene delivery to the central nervous system and bypass the blood-brain barrier so as to exploit the biological effectiveness of the choroid plexus as a portal of entry into the brain. Copyright © 2010 Elsevier B.V. All rights reserved.

Langerhans cell precursors acquire RANK/CD265 in prenatal human skin

PubMed Central

Schöppl, Alice; Botta, Albert; Prior, Marion; Akgün, Johnnie; Schuster, Christopher; Elbe-Bürger, Adelheid

2015-01-01

The skin is the first barrier against foreign pathogens and the prenatal formation of a strong network of various innate and adaptive cells is required to protect the newborn from perinatal infections. While many studies about the immune system in healthy and diseased adult human skin exist, our knowledge about the cutaneous prenatal/developing immune system and especially about the phenotype and function of antigen-presenting cells such as epidermal Langerhans cells (LCs) in human skin is still scarce. It has been shown previously that LCs in healthy adult human skin express receptor activator of NF-κB (RANK), an important molecule prolonging their survival. In this study, we investigated at which developmental stage LCs acquire this important molecule. Immunofluorescence double-labeling of cryostat sections revealed that LC precursors in prenatal human skin either do not yet [10–11 weeks of estimated gestational age (EGA)] or only faintly (13–15 weeks EGA) express RANK. LCs express RANK at levels comparable to adult LCs by the end of the second trimester. Comparable with adult skin, dermal antigen-presenting cells at no gestational age express this marker. These findings indicate that epidermal leukocytes gradually acquire RANK during gestation – a phenomenon previously observed also for other markers on LCs in prenatal human skin. PMID:25722033

Identification and comparative analysis of the epidermal differentiation complex in snakes

PubMed Central

Brigit Holthaus, Karin; Mlitz, Veronika; Strasser, Bettina; Tschachler, Erwin; Alibardi, Lorenzo; Eckhart, Leopold

2017-01-01

The epidermis of snakes efficiently protects against dehydration and mechanical stress. However, only few proteins of the epidermal barrier to the environment have so far been identified in snakes. Here, we determined the organization of the Epidermal Differentiation Complex (EDC), a cluster of genes encoding protein constituents of cornified epidermal structures, in snakes and compared it to the EDCs of other squamates and non-squamate reptiles. The EDC of snakes displays shared synteny with that of the green anole lizard, including the presence of a cluster of corneous beta-protein (CBP)/beta-keratin genes. We found that a unique CBP comprising 4 putative beta-sheets and multiple cysteine-rich EDC proteins are conserved in all snakes and other squamates investigated. Comparative genomics of squamates suggests that the evolution of snakes was associated with a gene duplication generating two isoforms of the S100 fused-type protein, scaffoldin, the origin of distinct snake-specific EDC genes, and the loss of other genes that were present in the EDC of the last common ancestor of snakes and lizards. Taken together, our results provide new insights into the evolution of the skin in squamates and a basis for the characterization of the molecular composition of the epidermis in snakes. PMID:28345630

Factitious thyrotoxicosis induced by mesotherapy: a case report.

PubMed

Danilovic, Debora Lucia Seguro; Bloise, Walter; Knobel, Meyer; Marui, Suemi

2008-06-01

Mesotherapy consists of cutaneous injections of a mixture of compounds and has recently been used for cosmetic purposes to reduce local fat and cellulite. To date, several reports have described only local adverse events related to this therapy. We describe the first report of a female patient who developed thyrotoxicosis due to cosmetic mesotherapy with triiodothyroacetic acid in its formulation. Apart from mechanical rupture of the epidermal barrier, a disturbance of type III deiodinase activity or skin fibroblast paracrine function and vascular alterations related to simultaneously injected vasoactive compounds were observed. These findings could be related to thyroid hormone metabolite absorption and systemic consequences in the reported case. We describe factitious thyrotoxicosis induced by mesotherapy, to raise awareness of a systemic adverse effect resulting from this widespread cosmetic practice.

Influence of niacinamide containing formulations on the molecular and biophysical properties of the stratum corneum.

PubMed

Mohammed, D; Crowther, J M; Matts, P J; Hadgraft, J; Lane, M E

2013-01-30

Niacinamide-containing moisturisers are known be efficacious in alleviating dry skin conditions and improving stratum corneum (SC) barrier function. However, the mechanisms of action of niacinamide at the molecular level in the SC are still not well understood. Previously, we have reported the development of novel methods to probe SC barrier properties in vivo. The aim of the present study was to characterise changes in Trans Epidermal Water Loss (TEWL), corneocyte surface area and maturity, selected protease activities and SC thickness after repeated application of a simple vehicle containing niacinamide. A commercial formulation was also included as a reference. The left and right mid-volar forearms of 20 healthy volunteers were used as study sites, to which topical formulations were applied twice daily for 28 days. After successive tape-stripping, corneocyte maturity and surface area were assessed. In addition, activity of the desquamatory kallikrein (KLK) protease enzymes KLK5 and KLK7, and tryptase and plasmin (implicated in inflammatory process) were measured using a fluorogenic probe assay. The amount of protein removed and TEWL were also recorded. SC thickness before and after treatment was determined using Confocal Raman Spectroscopy (CRS). Overall (i) corneocyte maturity and surface area decreased with increasing number of tape strips, (ii) activity of both the desquamatory and inflammatory enzymes was highest in the outer layers of the SC and decreased with depth (iii) TEWL increased as more SC layers were removed. Furthermore, areas treated with formulations containing niacinamide were significantly different to pre-treatment baseline and untreated/vehicle-control treated sites, with larger and more mature corneocytes, decreased inflammatory activity, decreased TEWL and increased SC thickness. These data (a) confirm the utility of measures and metrics developed previously for the non-invasive assay of SC barrier function, (b) present an holistic picture of a SC compartment managing barrier function through dynamic optimisation of pathlength and quality of building materials used, and (c) shed new light on niacinamide as a topical formulation adjunct with unique SC barrier-augmentation properties. Copyright © 2012 Elsevier B.V. All rights reserved.

Epidermal keratinocytes initiate wound healing and pro-inflammatory immune responses following percutaneous schistosome infection

PubMed Central

Bourke, Claire D.; Prendergast, Catriona T.; Sanin, David E.; Oulton, Tate E.; Hall, Rebecca J.; Mountford, Adrian P.

2015-01-01

Keratinocytes constitute the majority of cells in the skin’s epidermis, the first line of defence against percutaneous pathogens. Schistosome larvae (cercariae) actively penetrate the epidermis to establish infection, however the response of keratinocytes to invading cercariae has not been investigated. Here we address the hypothesis that cercariae activate epidermal keratinocytes to promote the development of a pro-inflammatory immune response in the skin. C57BL/6 mice were exposed to Schistosoma mansoni cercariae via each pinna and non-haematopoietic cells isolated from epidermal tissue were characterised for the presence of different keratinocyte sub-sets at 6, 24 and 96 h p.i. We identified an expansion of epidermal keratinocyte precursors (CD45−, CD326−, CD34+) within 24 h of infection relative to naïve animals. Following infection, cells within the precursor population displayed a more differentiated phenotype (α6integrin−) than in uninfected skin. Parallel immunohistochemical analysis of pinnae cryosections showed that this expansion corresponded to an increase in the intensity of CD34 staining, specifically in the basal bulge region of hair follicles of infected mice, and a higher frequency of keratinocyte Ki67+ nuclei in both the hair follicle and interfollicular epidermis. Expression of pro-inflammatory cytokine and stress-associated keratin 6b genes was also transiently upregulated in the epidermal tissue of infected mice. In vitro exposure of keratinocyte precursors isolated from neonatal mouse skin to excretory/secretory antigens released by penetrating cercariae elicited IL-1α and IL-1β production, supporting a role for keratinocyte precursors in initiating cutaneous inflammatory immune responses. Together, these observations indicate that S.mansoni cercariae and their excretory/secretory products act directly upon epidermal keratinocytes, which respond by initiating barrier repair and pro-inflammatory mechanisms similar to those observed in epidermal wound healing. PMID:25575749

Dorso-ventral skin characterization of the farmed fish gilthead seabream (Sparus aurata)

PubMed Central

Cordero, Héctor; Ceballos-Francisco, Diana; Cuesta, Alberto

2017-01-01

The skin is the first barrier of defence in fish, protecting against any external stressor and preserving the integrity and homeostasis of the fish body. The aim of this study was to characterise gilthead seabream skin by isolating cells and studying the cell cycle by flow cytometry, to study the skin histology by scanning electron microscopy and the transcription level of some immune-relevant genes by RT-PCR. Furthermore, the results obtained from samples taken from the dorsal and the ventral part of the specimens are compared. No differences were observed in the cell cycle of cells isolated from the dorsal and ventral zones of the skin or in the gene expression of the genes studied in both epidermal zones. However, the epidermis thickness of the ventral skin was higher than that of the dorsal skin, as demonstrated by image analysis using light microscopy. Besides, scanning electron microscopy pointed to a greater cell size and area of microridges in the apical part of the dorsal epidermal cells compared with ventral skin epidermal cells. This study represents a step forward in our knowledge of the skin structure of an important farmed teleost, gilthead seabream, one of the most commonly farmed fish worldwide. Furthermore, for functional characterization, experimental wounds were carried out comparing the wound healing rate between the dorsal and ventral regions of skin over the time. The results showed higher ratio of wound healing in the ventral region, whose wounds were closed after 15 days, compared to dorsal region of skin. Taking into account all together, this study represents a step forward in our knowledge of the skin structure and skin regeneration of an important farmed teleost, gilthead seabream, one of the most commonly farmed fish worldwide. PMID:28666033

Nicotinic Acid Receptor Abnormalities in Human Skin Cancer: Implications for a Role in Epidermal Differentiation

PubMed Central

Bermudez, Yira; Benavente, Claudia A.; Meyer, Ralph G.; Coyle, W. Russell; Jacobson, Myron K.; Jacobson, Elaine L.

2011-01-01

Background Chronic UV skin exposure leads to epidermal differentiation defects in humans that can be largely restored by pharmacological doses of nicotinic acid. Nicotinic acid has been identified as a ligand for the human G-protein-coupled receptors GPR109A and GPR109B that signal through Gi-mediated inhibition of adenylyl cyclase. We have examined the expression, cellular distribution, and functionality of GPR109A/B in human skin and skin derived epidermal cells. Results Nicotinic acid increases epidermal differentiation in photodamaged human skin as judged by the terminal differentiation markers caspase 14 and filaggrin. Both GPR109A and GPR109B genes are transcribed in human skin and in epidermal keratinocytes, but expression in dermal fibroblasts is below limits of detection. Receptor transcripts are greatly over-expressed in squamous cell cancers. Receptor protein in normal skin is prominent from the basal through granular layers of the epidermis, with cellular localization more dispersive in the basal layer but predominantly localized at the plasma membrane in more differentiated epidermal layers. In normal human primary and immortalized keratinocytes, nicotinic acid receptors show plasma membrane localization and functional Gi-mediated signaling. In contrast, in a squamous cell carcinoma derived cell line, receptor protein shows a more diffuse cellular localization and the receptors are nearly non-functional. Conclusions The results of these studies justify future genetic and pharmacological intervention studies to define possible specific role(s) of nicotinic acid receptors in human skin homeostasis. PMID:21655214

IL-1β-Induced Protection of Keratinocytes against Staphylococcus aureus-Secreted Proteases Is Mediated by Human β-Defensin 2.

PubMed

Wang, Bingjie; McHugh, Brian J; Qureshi, Ayub; Campopiano, Dominic J; Clarke, David J; Fitzgerald, J Ross; Dorin, Julia R; Weller, Richard; Davidson, Donald J

2017-01-01

Atopic dermatitis (AD) is a common chronic inflammatory skin disease that results in significant morbidity. A hallmark of AD is disruption of the critical barrier function of upper epidermal layers, causatively linked to environmental stimuli, genetics, and infection, and a critical current target for the development of new therapeutic and prophylactic interventions. Staphylococcus aureus is an AD-associated pathogen producing virulence factors that induce skin barrier disruption in vivo and contribute to AD pathogenesis. We show, using immortalized and primary keratinocytes, that S. aureus protease SspA/V8 is the dominant secreted factor (in laboratory and AD clinical strains of S. aureus) inducing barrier integrity impairment and tight junction damage. V8-induced integrity damage was inhibited by an IL-1β-mediated mechanism, independent of effects on claudin-1. Induction of keratinocyte expression of the antimicrobial/host defense peptide human β-defensin 2 (hBD2) was found to be the mechanism underpinning this protective effect. Endogenous hBD2 expression was required and sufficient for protection against V8 protease-mediated integrity damage, and exogenous application of hBD2 was protective. This modulatory property of hBD2, unrelated to antibacterial effects, gives new significance to the defective induction of hBD2 in the barrier-defective skin lesions of AD and indicates therapeutic potential. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Morphological and functional studies on the epidermal cells of amphioxus ( Branchiostoma belcheri tsingtauense) at different developmental stages

NASA Astrophysics Data System (ADS)

Mao, Bing-Yu; Sun, Xiao-Yang; Zhang, Hong-Wei; Zhang, Shi-Cui; Wu, Xian-Han

1997-09-01

Epidermal cells of amphioxus at different developmental stages were investigated by electron microscopy and colloidal carbon tracing experiments. Amphioxus epidermal cells showed different ultrastructural characteristics at larval and adult stages. The epidermal cells at all larval stages studied (24 96 h) had numerous vesicles containing electron dense materials in their apical cytoplasm. In tracing experiments, carbon particles were found in apical vesicles and interoellular spaces. Under scanning electron microscope, many crater-like protrusions were observed on the surface of the cells. These results indicated that amphioxus larval epidermal cells may be capable of endocytosis. The epidermal cells of 3-month and adult amphioxus were obviously secretory ones characterized by well-developed peripheral filaments, a prominent Golgi apparatus and abundant apical secretory vesicles. This study also showed that adult amphioxus body surface mucus contained lectin that could agglutinate human red blood cells. The authors propose that the epidermal cells of amphioxus larva and adult may contribute to the immune defense of the amimal by different means.

Human corpus luteum: presence of epidermal growth factor receptors and binding characteristics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ayyagari, R.R.; Khan-Dawood, F.S.

Epidermal growth factor receptors are present in many reproductive tissues but have not been demonstrated in the human corpus luteum. To determine the presence of epidermal growth factor receptors and its binding characteristics, we carried out studies on the plasma cell membrane fraction of seven human corpora lutea (days 16 to 25) of the menstrual cycle. Specific epidermal growth factor receptors were present in human corpus luteum. Insulin, nerve growth factor, and human chorionic gonadotropin did not competitively displace epidermal growth factor binding. The optimal conditions for corpus luteum-epidermal growth factor receptor binding were found to be incubation for 2more » hours at 4 degrees C with 500 micrograms plasma membrane protein and 140 femtomol /sup 125/I-epidermal growth factor per incubate. The number (mean +/- SEM) of epidermal growth factor binding sites was 12.34 +/- 2.99 X 10(-19) mol/micrograms protein; the dissociation constant was 2.26 +/- 0.56 X 10(-9) mol/L; the association constant was 0.59 +/- 0.12 X 10(9) L/mol. In two regressing corpora lutea obtained on days 2 and 3 of the menstrual cycle, there was no detectable specific epidermal growth factor receptor binding activity. Similarly no epidermal growth factor receptor binding activity could be detected in ovarian stromal tissue. Our findings demonstrate that specific receptors for epidermal growth factor are present in the human corpus luteum. The physiologic significance of epidermal growth factor receptors in human corpus luteum is unknown, but epidermal growth factor may be involved in intragonadal regulation of luteal function.« less

The role of the SCRAMBLED receptor-like kinase in patterning the Arabidopsis root epidermis.

PubMed

Kwak, Su-Hwan; Schiefelbein, John

2007-02-01

Cell-type patterning in the Arabidopsis root epidermis is achieved by a network of transcription factors and influenced by a position-dependent mechanism. The SCRAMBLED receptor-like kinase is required for the normal pattern to arise, but its precise role is not understood. Here we describe genetic and molecular studies to define the spatial and temporal role of SCM in epidermal patterning and its relationship to the transcriptional network. Our results suggest that SCM helps unspecified epidermal cells interpret their position in relation to the underlying cortical cells and establish distinct cell identities. Furthermore, SCM loss-of-function and overexpression analyses suggest that SCM influences cell fate through its negative transcriptional regulation of the WEREWOLF MYB gene in epidermal cells at the H position. We also find that SCM function is specifically required for patterning the post-embryonic root epidermis and not for the analogous epidermal cell-type patterning during embryogenesis or hypocotyl development. In addition, we show that two closely related SCM-like genes in Arabidopsis (SRF1 and SRF3) are not required alone or together with SCM for proper epidermal patterning. These findings help define the developmental and mechanistic role of SCM and suggest a new model for its action in root epidermal cell patterning.

Planar cell polarity pathway in vertebrate epidermal development, homeostasis and repair

PubMed Central

Dworkin, Sebastian; Jane, Stephen M

2011-01-01

The planar cell polarity (PCP) pathway plays a critical role in diverse developmental processes that require coordinated cellular movement, including neural tube closure and renal tubulogenesis. Recent studies have demonstrated that this pathway also has emerging relevance to the epidermis, as PCP signaling underpins many aspects of skin biology and pathology, including epidermal development, hair orientation, stem cell division and cancer. Coordinated cellular movement required for epidermal repair in mammals is also regulated by PCP signaling, and in this context, a new PCP gene encoding the developmental transcription factor Grainyhead-like 3 (Grhl3) is critical. This review focuses on the role that PCP signaling plays in the skin across a variety of epidermal functions and highlights perturbations that induce epidermal pathologies. PMID:22041517

Genetic analysis of Ras genes in epidermal development and tumorigenesis

PubMed Central

Drosten, Matthias; Lechuga, Carmen G; Barbacid, Mariano

2013-01-01

Proliferation and differentiation of epidermal keratinocytes are tightly controlled to ensure proper development and homeostasis of the epidermis. The Ras family of small GTPases has emerged as a central node in the coordination of cell proliferation in the epidermis. Recent genetic evidence from mouse models has revealed that the intensity of Ras signaling modulates the proliferative capacity of epidermal keratinocytes. Interfering with Ras signaling either by combined elimination of the 3 Ras genes from the basal layer of the epidermis or by overexpression of dominant-negative Ras isoforms caused epidermal thinning due to hypoproliferation of keratinocytes. In contrast, overexpression of oncogenic Ras mutants in different epidermal cell layers led to hyperproliferative phenotypes including the development of papillomas and squamous cell carcinomas. Here, we discuss the value of loss- and gain-of-function studies in mouse models to assess the role of Ras signaling in the control of epidermal proliferation. PMID:24150175

Identification of Candidate Transcriptional Regulators of Epidermal Transfer Cell Development in Vicia faba Cotyledons

PubMed Central

Arun-Chinnappa, Kiruba S.; McCurdy, David W.

2016-01-01

Transfer cells (TCs) are anatomically-specialized cells formed at apoplasmic-symplasmic bottlenecks in nutrient transport pathways in plants. TCs form invaginated wall ingrowths which provide a scaffold to amplify plasma membrane surface area and thus increase the density of nutrient transporters required to achieve enhanced nutrient flow across these bottlenecks. Despite their importance to nutrient transport in plants, little is known of the transcriptional regulation of wall ingrowth formation. Here, we used RNA-Seq to identify transcription factors putatively involved in regulating epidermal TC development in cotyledons of Vicia faba. Comparing cotyledons cultured for 0, 3, 9, and 24 h to induce trans-differentiation of epidermal TCs identified 43 transcription factors that showed either epidermal-specific or epidermal–enhanced expression, and 10 that showed epidermal-specific down regulation. Members of the WRKY and ethylene-responsive families were prominent in the cohort of transcription factors showing epidermal-specific or epidermal–enhanced expression, consistent with the initiation of TC development often representing a response to stress. Members of the MYB family were also prominent in these categories, including orthologs of MYB genes involved in localized secondary wall deposition in Arabidopsis thaliana. Among the group of transcription factors showing down regulation were various homeobox genes and members of the MADs-box and zinc-finger families of poorly defined functions. Collectively, this study identified several transcription factors showing expression characteristics and orthologous functions that indicate likely participation in transcriptional regulation of epidermal TC development in V. faba cotyledons. PMID:27252730

Skin-derived TSLP triggers progression from epidermal-barrier defects to asthma.

PubMed

Demehri, Shadmehr; Morimoto, Mitsuru; Holtzman, Michael J; Kopan, Raphael

2009-05-19

Asthma is a common allergic lung disease frequently affecting individuals with a prior history of eczema/atopic dermatitis (AD); however, the mechanism underlying the progression from AD to asthma (the so-called "atopic march") is unclear. Here we show that, like humans with AD, mice with skin-barrier defects develop AD-like skin inflammation and are susceptible to allergic asthma. Furthermore, we show that thymic stromal lymphopoietin (TSLP), overexpressed by skin keratinocytes, is the systemic driver of this bronchial hyper-responsiveness. As an AD-like model, we used mice with keratinocyte-specific deletion of RBP-j that sustained high systemic levels of TSLP. Antigen-induced allergic challenge to the lung airways of RBP-j-deficient animals resulted in a severe asthmatic phenotype not seen in similarly treated wild-type littermates. Elimination of TSLP signaling in these animals blocked the atopic march, demonstrating that high serum TSLP levels were required to sensitize the lung to allergic inflammation. Furthermore, we analyzed outbred K14-TSLP(tg) mice that maintained high systemic levels of TSLP without developing any skin pathology. Importantly, epidermal-derived TSLP was sufficient to trigger the atopic march, sensitizing the lung airways to inhaled allergens in the absence of epicutaneous sensitization. Based on these findings, we propose that in addition to early treatment of the primary skin-barrier defects, selective inhibition of systemic TSLP may be the key to blocking the development of asthma in AD patients.

[Dermoepidermic junction: a selective, complex and vital barrier].

PubMed

Frede, Silvia C; Dionisio de Cabalier, María E; Zaya, Alejandro; Hliba, Ernesto

2004-01-01

Dermoepidermic junction (DEJ) is a highly complex region, containing a great variety of cellular elements, which despite of having different embriogenesis, interact with each other, generating different substances that keep the function and homeostasis of the greatest organ of the human body. DEJ is regarded as a highly specialized basal lamina, which acts as a highly selective pathway for the migration of cells and macromolecules, inducing cellular differentiation and micro enviromental metabolism modifications. DEJ may be divided into three zones regarding the basal lamina 1--the nearest to epidermic zone, having tonofilaments and hemidesmosomes, which keep anchored basal cells. This region is limited by the lamina densa 2--the intermediate zone, represented exclusively by lamina densa and finally the lamina 3,--the third region--extends from lamina densa to the upper dermis and extracelullar matrix. Despite there is much to learn about DEJ, the knowledge about each molecule and function of every compartment will enable us to know more about the pathogenesis of several dermatologic diseases, with a great prevalence in the clinical practice.

The use of a measure of acute irritation to predict the outcome of repeated usage of hand soap products.

PubMed

Williams, C; Wilkinson, M; McShane, P; Pennington, D; Fernandez, C; Pierce, S

2011-06-01

Healthcare-associated infection is an important worldwide problem that could be reduced by better hand hygiene practice. However, an increasing number of healthcare workers are experiencing irritant contact dermatitis of the hands as a result of repeated hand washing. This may lead to a reduced level of compliance with regard to hand hygiene. To assess whether a measure of acute irritation by hand soaps could predict the effects of repeated usage over a 2-week period. In a double-blind, randomized comparison study, the comparative irritation potential of four different hand soaps was assessed over a 24-h treatment period. The effect of repeated hand washing with the hand soap products over a 2-week period in healthy adult volunteers on skin barrier function was then determined by assessment of transepidermal water loss (TEWL), epidermal hydration and a visual assessment using the Hand Eczema Severity Index (HECSI) at days 0, 7 and 14. A total of 121 subjects from the 123 recruited completed phase 1 of the study. All four products were seen to be significantly different from each other in terms of the irritant reaction observed and all products resulted in a significantly higher irritation compared with the no-treatment control. Seventy-nine of the initial 121 subjects were then enrolled into the repeated usage study. A statistically significant worsening of the clinical condition of the skin as measured by HECSI was seen from baseline to day 14 in those subjects repeatedly washing their hands with two of the four soap products (products C and D) with P-values of 0·02 and 0·01, respectively. Subclinical assessment of the skin barrier function by measuring epidermal hydration was significantly increased from baseline to day 7 after repeated hand washing with products A, B and D but overall no significant change was seen in all four products tested by day 14. A statistically significant increase in TEWL at day 14 was seen for product A (P = 0·02) indicating a worsening of skin barrier function. This effect was also seen initially for product D at day 7 although this was then lost at day 14. Further regression analysis was then performed to see if the acute irritant test data for each product correlated with the skin barrier data from the repeated usage component of the study. This showed that the results of acute irritant testing of the individual products did not predict the results of chronic use of hand soaps. The results from phase 2 of our study confirm the work of previous studies that show that regular exposure to irritants in daily life leads to stratum corneum damage and impairment of the skin barrier. Although significant differences were seen between the products in phase 1 of the study, regression analysis showed that the results of patch testing of the individual products did not predict the results of chronic use of hand soaps. When designing a study to assess the effects of cumulative use of a product on the skin, the study should mirror the use conditions of the product as closely as possible. © 2011 The Authors. BJD © 2011 British Association of Dermatologists.

[Skin hydration and hydrating products].

PubMed

Duplan, H; Nocera, T

2018-05-01

One of the skin's principal functions is to protect the body against its environment by maintaining an effective epidermal barrier, not only against external factors, but also to prevent water loss from the body. Indeed, water homeostasis is vital for the normal physiological functioning of skin. Hydration levels affect not only visible microscopic parameters such as the suppleness and softness of skin, but also molecular parameters, enzyme activities and cellular signalling within the epidermis. The body is continually losing some of its water, but this phenomenon is limited and the optimal hydration gradient in skin is ensured via a set of sophisticated regulatory processes that rely on the functional and dynamic properties of the uppermost level of the skin consisting of the stratum corneum. The present article brings together data recently acquired in the fields of skin hydration and the characterisation of dehydrated or dry skin, whether through study of the regulatory processes involved or as a result of changes in the techniques used for in situ measurement, and thus in optimisation of management. Copyright © 2018. Published by Elsevier Masson SAS.

A comprehensive pathophysiology of dandruff and seborrheic dermatitis - towards a more precise definition of scalp health.

PubMed

Schwartz, James R; Messenger, Andrew G; Tosti, Antonella; Todd, Gail; Hordinsky, Maria; Hay, Roderick J; Wang, Xuemin; Zachariae, Claus; Kerr, Kathy M; Henry, James P; Rust, Rene C; Robinson, Michael K

2013-03-27

Despite an increasing knowledge of dandruff and seborrheic dermatitis (D/SD), the pathophysiological understanding is still incomplete but suggests a role of Malassezia yeasts in triggering inflammatory and hyper-proliferative epidermal responses. The objective of this report is to review published literature from in vivo studies of D/SD populations to provide a more complete description of overall scalp health. New biomolecular capabilities establish a depth of pathophysiological understanding not previously achievable with traditional means of investigation. Biomarkers representing inflammation, hyper-proliferation and barrier function are all perturbed by the D/SD condition and robustly respond to therapeutic resolution. These biomarkers can be sampled noninvasively, enabling their use in routine clinical evaluations as either surrogate endpoints or complementary ones to classical signs/symptoms to broaden the etiological learning.

Comorbidity in Atopic Dermatitis.

PubMed

Simpson, Eric L

2012-03-01

The negative impact of atopic dermatitis (AD) often extends beyond the skin. Children with AD experience increased rates of infectious, mental health, and allergic diseases compared to their non-atopic peers. The mechanisms underlying these associations remain elusive. New insights from genetic and epidermal research pinpoint the skin barrier as a primary initiator of AD. Epicutaneous sensitization represents an intriguing new model which links a disrupted skin barrier to the later development of IgE-mediated diseases in patients with AD. Recent epidemiological studies have identified new comorbidities linked to AD as well, including several mental health disorders and obesity. This manuscript reviews the recent literature regarding both classic and newly described AD comorbidities.

Increased Number of Langerhans Cells in the Epidermis of Diabetic Foot Ulcers Correlates with Healing Outcome

PubMed Central

Stojadinovic, Olivera; Yin, Natalie; Lehmann, Janin; Pastar, Irena; Kirsner, Robert S.; Tomic-Canic, Marjana

2015-01-01

Langerhans cells (LCs) are a specialized subset of epidermal dendritic cells. They represent one of the first cells of immunological barrier and play an important role during the inflammatory phase of acute wound healing. Despite considerable progress in our understanding of the immunopathology of diabetes mellitus and its associated co-morbidities such as diabetic foot ulcers (DFUs), considerable gaps in our knowledge exist. In this study, we utilized the human ex vivo wound model and confirmed the increased epidermal LCs at wound edges during early phases of wound healing. Next, we aimed to determine differences in quantity of LCs between normal human and diabetic foot skin and to learn if the presence of LCs correlates with the healing outcome in DFUs. We utilized immunofluorescence to detect CD207+ LCs in specimens from normal and diabetic foot skin and DFU wound edges. Specimens from DFUs were collected at the initial visit and 4 weeks at the time when the healing outcome was determined. DFUs that decreased in size by >50% were considered to be healing, while DFUs with a size reduction of <50% were considered non-healing. Quantitative assessment of LCs showed a higher number of LCs in healing when compared to non–healing DFU’s. Our findings provide evidence that LCs are present in higher number in diabetic feet than normal foot skin. Healing DFUs show a higher number of LCs compared to non-healing DFUs. These findings indicate that the epidermal immune barrier plays an important role in the DFU healing outcome and may offer new therapeutic avenues targeting LC in non-healing DFUs. PMID:24277309

Epidermal Notch signalling: differentiation, cancer and adhesion.

PubMed

Watt, Fiona M; Estrach, Soline; Ambler, Carrie A

2008-04-01

The Notch pathway plays an important role in regulating epidermal differentiation. Notch ligands, receptors and effectors are expressed in a complex and dynamic pattern in embryonic and adult skin. Genetic ablation or activation of the pathway reveals that Notch signalling promotes differentiation of the hair follicle, sebaceous gland and interfollicular epidermal lineages and that Notch acts as an epidermal tumour suppressor. Notch signalling interacts with a range of other pathways to fulfil these functions and acts via RBP-Jkappa dependent and independent mechanisms. The effects on differentiation can be cell autonomous and non-autonomous, and Notch contributes to stem cell clustering via modulation of cell adhesion.

Concise Review: Tissue-Engineered Skin and Nerve Regeneration in Burn Treatment

PubMed Central

Blais, Mathieu; Parenteau-Bareil, Rémi; Cadau, Sébastien

2013-01-01

Burns not only destroy the barrier function of the skin but also alter the perceptions of pain, temperature, and touch. Different strategies have been developed over the years to cover deep and extensive burns with the ultimate goal of regenerating the barrier function of the epidermis while recovering an acceptable aesthetic aspect. However, patients often complain about a loss of skin sensation and even cutaneous chronic pain. Cutaneous nerve regeneration can occur from the nerve endings of the wound bed, but it is often compromised by scar formation or anarchic wound healing. Restoration of pain, temperature, and touch perceptions should now be a major challenge to solve in order to improve patients' quality of life. In addition, the cutaneous nerve network has been recently highlighted to play an important role in epidermal homeostasis and may be essential at least in the early phase of wound healing through the induction of neurogenic inflammation. Although the nerve regeneration process was studied largely in the context of nerve transections, very few studies have been aimed at developing strategies to improve it in the context of cutaneous wound healing. In this concise review, we provide a description of the characteristics of and current treatments for extensive burns, including tissue-engineered skin approaches to improve cutaneous nerve regeneration, and describe prospective uses for autologous skin-derived adult stem cells to enhance recovery of the skin's sense of touch. PMID:23734060

Heparin-binding EGF-like growth factor and enteric neural stem cell transplantation in the prevention of experimental necrotizing enterocolitis in mice.

PubMed

Wei, Jia; Zhou, Yu; Besner, Gail E

2015-07-01

Necrotizing enterocolitis (NEC) is associated with loss of neurons and glial cells in the enteric nervous system (ENS). Our goal was to determine whether enteric neural stem cell (NSC) transplantation, in conjunction with heparin-binding epidermal growth factor-like growth factor (HB-EGF), could protect against experimental NEC. In vitro, HB-EGF on NSC proliferation and migration, and the effects of receptors utilized by HB-EGF to exert these effects, were determined. In vivo, mouse pups were exposed to experimental NEC and treated with NSC alone, HB-EGF alone, NSC+HB-EGF, or HB-EGF overexpressing NSC. NSC engraftment and differentiation into neurons in the ENS, intestinal injury, intestinal permeability, and intestinal motility were determined. HB-EGF promoted NSC proliferation via ErbB-1 receptors and enhanced NSC migration via ErbB-1, ErbB-4, and Nardilysin receptors. HB-EGF significantly enhanced the engraftment of transplanted NSC into the ENS during NEC. NSC transplantation significantly reduced NEC incidence and improved gut barrier function and intestinal motility, and these effects were augmented by simultaneous administration of HB-EGF or by transplantation of HB-EGF overexpressing NSC. HB-EGF promotes NSC proliferation and migration. HB-EGF and NSC reduce intestinal injury and improve gut barrier function and intestinal motility in experimental NEC. Combined HB-EGF and NSC transplantation may represent a potential future therapy to prevent NEC.

Pinus densiflora bark extract ameliorates 2,4-dinitrochlorobenzene-induced atopic dermatitis in NC/Nga mice by regulating Th1/Th2 balance and skin barrier function.

PubMed

Lee, Jun Woo; Wu, Qianwen; Jang, Young Pyo; Choung, Se Young

2018-06-01

Korean red pine (Pinus densiflora) bark has been traditionally used in Korea and other parts of East Asia to relieve inflammatory diseases. Although many studies using P. densiflora bark have been reported, its effect on atopic dermatitis (AD) has not been elucidated. Thus, we investigated whether the P. densiflora bark extract (PBE) has potential to attenuate AD symptoms and elucidated the molecular mechanism. Oral administration of PBE to mice with 2,4-dinitrochlorobenzene (DNCB)-induced AD lessened dermatitis scores and scratching behavior and significantly reduced measures of epidermal thickness, infiltration of mast cells and eosinophils, levels of immunoglobulin E (IgE), and IgG 1 /IgG 2a ratio in serum. PBE not only inhibited IL-4, IL-5, and IL-13 but also increased IFN-γ in splenic production. Furthermore, PBE significantly suppressed mRNA expression of thymic stromal lymphopoietin and further downregulated the mRNA expression of Th2 and Th17 cytokines such as IL-4, IL-13, IL-17, IL-31, and TNF-α. In addition, the protein expressions of filaggrin, involucrin, and loricrin in lesional skin were recovered by PBE. These results suggest that PBE attenuates DNCB-induced AD via regulating Th1/Th2 balance and skin barrier function. Copyright © 2018 John Wiley & Sons, Ltd.

Functions of Vγ4 T Cells and Dendritic Epidermal T Cells on Skin Wound Healing

PubMed Central

Li, Yashu; Wu, Jun; Luo, Gaoxing; He, Weifeng

2018-01-01

Wound healing is a complex and dynamic process that progresses through the distinct phases of hemostasis, inflammation, proliferation, and remodeling. Both inflammation and re-epithelialization, in which skin γδ T cells are heavily involved, are required for efficient skin wound healing. Dendritic epidermal T cells (DETCs), which reside in murine epidermis, are activated to secrete epidermal cell growth factors, such as IGF-1 and KGF-1/2, to promote re-epithelialization after skin injury. Epidermal IL-15 is not only required for DETC homeostasis in the intact epidermis but it also facilitates the activation and IGF-1 production of DETC after skin injury. Further, the epidermal expression of IL-15 and IGF-1 constitutes a feedback regulatory loop to promote wound repair. Dermis-resident Vγ4 T cells infiltrate into the epidermis at the wound edges through the CCR6-CCL20 pathway after skin injury and provide a major source of IL-17A, which enhances the production of IL-1β and IL-23 in the epidermis to form a positive feedback loop for the initiation and amplification of local inflammation at the early stages of wound healing. IL-1β and IL-23 suppress the production of IGF-1 by DETCs and, therefore, impede wound healing. A functional loop may exist among Vγ4 T cells, epidermal cells, and DETCs to regulate wound repair.

microRNA-184 Induces a Commitment Switch to Epidermal Differentiation.

PubMed

Nagosa, Sara; Leesch, Friederike; Putin, Daria; Bhattacharya, Swarnabh; Altshuler, Anna; Serror, Laura; Amitai-Lange, Aya; Nasser, Waseem; Aberdam, Edith; Rouleau, Matthieu; Tattikota, Sudhir G; Poy, Matthew N; Aberdam, Daniel; Shalom-Feuerstein, Ruby

2017-12-12

miR-184 is a highly evolutionary conserved microRNA (miRNA) from fly to human. The importance of miR-184 was underscored by the discovery that point mutations in miR-184 gene led to corneal/lens blinding disease. However, miR-184-related function in vivo remained unclear. Here, we report that the miR-184 knockout mouse model displayed increased p63 expression in line with epidermal hyperplasia, while forced expression of miR-184 by stem/progenitor cells enhanced the Notch pathway and induced epidermal hypoplasia. In line, miR-184 reduced clonogenicity and accelerated differentiation of human epidermal cells. We showed that by directly repressing cytokeratin 15 (K15) and FIH1, miR-184 induces Notch activation and epidermal differentiation. The disease-causing miR-184 C57U mutant failed to repress K15 and FIH1 and to induce Notch activation, suggesting a loss-of-function mechanism. Altogether, we propose that, by targeting K15 and FIH1, miR-184 regulates the transition from proliferation to early differentiation, while mis-expression or mutation in miR-184 results in impaired homeostasis. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Role of fibroblast-derived factors in the pathogenesis of melasma.

PubMed

Byun, J W; Park, I S; Choi, G S; Shin, J

2016-08-01

The hyperactive melanocytes present in melasma skin are confined to the epidermis, but epidermal ablation to treat melasma pigmentation may lead to disease recurrence and aggravation. Melanocyte function is regulated by interactions between melanocytes and neighbouring cells such as keratinocytes and fibroblasts. Because melasma skin usually shows dermal changes after exposure to sunlight, we hypothesized that sun-damaged fibroblasts might play a crucial role in the pathogenesis of melasma. In this study, the melanogenic role of primary cultured fibroblasts from human melasma skin was investigated. We explored whether primary cultured fibroblasts from melasma tissue have a melanogenic function on cultured human epidermal melanocytes and artificial skin. The cytokine profile derived from fibroblasts and their effect on the pigmented epidermal equivalents were investigated. Fibroblasts from the melasma lesion and perilesional skin increased melanogenesis in cultured human epidermal melanocytes and in artificial skin. Fibroblasts from the melasma lesion and perilesional skin secreted more nerve growth factor (NGF)-β than those in normal buttock skin, and also increased melanogenesis and the expression level of NGF-β in cultured human epidermal melanocytes and artificial skin. These results suggest that fibroblasts may play a role in melanogenesis and the pathogenesis of melasma. © 2016 British Association of Dermatologists.

Human eccrine sweat gland cells turn into melanin-uptaking keratinocytes in dermo-epidermal skin substitutes.

PubMed

Böttcher-Haberzeth, Sophie; Biedermann, Thomas; Pontiggia, Luca; Braziulis, Erik; Schiestl, Clemens; Hendriks, Bart; Eichhoff, Ossia M; Widmer, Daniel S; Meuli-Simmen, Claudia; Meuli, Martin; Reichmann, Ernst

2013-02-01

Recently, Biedermann et al. (2010) have demonstrated that human eccrine sweat gland cells can develop a multilayered epidermis. The question still remains whether these cells can fulfill exclusive and very specific functional properties of epidermal keratinocytes, such as the incorporation of melanin, a feature absent in sweat gland cells. We added human melanocytes to eccrine sweat gland cells to let them develop into an epidermal analog in vivo. The interaction between melanocytes and sweat gland-derived keratinocytes was investigated. The following results were gained: (1) macroscopically, a pigmentation of the substitutes was seen 2-3 weeks after transplantation; (2) we confirmed the development of a multilayered, stratified epidermis with melanocytes distributed evenly throughout the basal layer; (3) melanocytic dendrites projected to suprabasal layers; and (4) melanin was observed to be integrated into former eccrine sweat gland cells. These skin substitutes were similar or equal to skin substitutes cultured from human epidermal keratinocytes. The only differences observed were a delay in pigmentation and less melanin uptake. These data suggest that eccrine sweat gland cells can form a functional epidermal melanin unit, thereby providing striking evidence that they can assume one of the most characteristic keratinocyte properties.

Myosin II activity is required for functional leading-edge cells and closure of epidermal sheets in fish skin ex vivo.

PubMed

Morita, Toshiyuki; Tsuchiya, Akiko; Sugimoto, Masazumi

2011-09-01

Re-epithelialization in skin wound healing is a process in which epidermal sheets grow and close the wound. Although the actin-myosin system is thought to have a pivotal role in re-epithelialization, its role is not clear. In fish skin, re-epithelialization occurs around 500 μm/h and is 50 times faster than in mammalian skin. We had previously reported that leading-edge cells of the epidermal outgrowth have both polarized large lamellipodia and "purse string"-like actin filament cables in the scale-skin culture system of medaka fish, Oryzias latipes (Cell Tissue Res, 2007). The actin purse-string (APS) is a supracellular contractile machinery in which adherens junctions (AJs) link intracellular myosin II-including actin cables between neighboring cells. In this study, we developed a modified "face-to-face" scale-skin culture system as an ex vivo model to study epidermal wound healing, and examined the role of the actin-myosin system in the rapid re-epithelialization using a myosin II ATPase inhibitor, blebbistatin. A low level of blebbistatin suppressed the formation of APS and induced the dissociation of keratocytes from the leading edge without attenuating the growth of the epidermal sheet or the migration rate of solitary keratocytes. AJs in the superficial layer showed no obvious changes elicited by blebbistatin. However, two epidermal sheets without APSs did not make a closure with each other, which was confirmed by inhibiting the connecting AJs between the superficial layers. These results suggest that myosin II activity is required for functional leading-edge cells and for epidermal closure.

Langerhans cell precursors acquire RANK/CD265 in prenatal human skin.

PubMed

Schöppl, Alice; Botta, Albert; Prior, Marion; Akgün, Johnnie; Schuster, Christopher; Elbe-Bürger, Adelheid

2015-01-01

The skin is the first barrier against foreign pathogens and the prenatal formation of a strong network of various innate and adaptive cells is required to protect the newborn from perinatal infections. While many studies about the immune system in healthy and diseased adult human skin exist, our knowledge about the cutaneous prenatal/developing immune system and especially about the phenotype and function of antigen-presenting cells such as epidermal Langerhans cells (LCs) in human skin is still scarce. It has been shown previously that LCs in healthy adult human skin express receptor activator of NF-κB (RANK), an important molecule prolonging their survival. In this study, we investigated at which developmental stage LCs acquire this important molecule. Immunofluorescence double-labeling of cryostat sections revealed that LC precursors in prenatal human skin either do not yet [10-11 weeks of estimated gestational age (EGA)] or only faintly (13-15 weeks EGA) express RANK. LCs express RANK at levels comparable to adult LCs by the end of the second trimester. Comparable with adult skin, dermal antigen-presenting cells at no gestational age express this marker. These findings indicate that epidermal leukocytes gradually acquire RANK during gestation - a phenomenon previously observed also for other markers on LCs in prenatal human skin. Copyright © 2015 The Authors. Published by Elsevier GmbH.. All rights reserved.

Dimethyl sulfoxide could be a useful probe to evaluate unusual skin angioneurotic reaction and epidermal permeability.

PubMed

Chen, Shuang Y; Wang, Xue M; Liu, Yan Q; Gao, Yan R; Liu, Xiao P; Li, Shu Y; Dong, Ya Q

2014-03-01

Dimethyl sulfoxide (DMSO) has been suggested as a traditional chemical probe for assessing skin susceptibility and barrier function. The purpose of this study was to determine the role of DMSO test for the evaluation of unusual skin angioneurotic reaction and epidermal permeability. Thirty healthy volunteers were exposed to 98% DMSO on the flexor forearm skin for three exposure durations (5 min, 10 min and 15 min). Clinical visual score and biological physical parameters were obtained. The volunteers were divided into two groups according to the clinical visual scoring. The skin parameters were subsequently analyzed. There was a significant correlation between clinical visual score and biological physical parameters. The skin color parameters (a*, oxyhemoglobin, erythema and melanin index) and blood flow values were significant between two groups regardless of duration of DMSO exposure, and a significant difference between density values could also be detected if we regrouped the volunteers according to the sting-producing score. Our results also suggested there was no correlation between questionnaire score and clinical visual score or other parameters. Application of 98% DMSO for 10 min combined with a* (at 30 min) and blood flow (at 10 min) values could help us to identify persons with a hyper-angionerotic reaction to chemical stimulus. The penetrative activity of DMSO correlated with the thickness of the individual's skin.

Inhibitory effect of a novel combination of Salvia hispanica (chia) seed and Punica granatum (pomegranate) fruit extracts on melanin production.

PubMed

Diwakar, Ganesh; Rana, Jatinder; Saito, Lisa; Vredeveld, Doug; Zemaitis, Dorothy; Scholten, Jeffrey

2014-09-01

In recent years, dietary fatty acids have been extensively evaluated for nutritional as well as cosmetic benefits. Among the dietary fats, the omega-3 (ω3) and omega-6 (ω6) forms of polyunsaturated fatty acids (PUFAs) have been found to exhibit many biological functions in the skin such as prevention of transepidermal water loss, maintenance of the stratum corneum epidermal barrier, and disruption of melanogenesis in epidermal melanocytes. In this study, we examined the effect of chia seed extract, high in ω3 (linolenic acid) and ω6 (linoleic acid) PUFAs, for its capacity to affect melanogenesis. Chia seed extract was shown to inhibit melanin biosynthesis in Melan-a cells; however, linoleic and α-linolenic acids alone did not effectively reduce melanin content. Further investigation demonstrated that chia seed extract in combination with pomegranate fruit extract had a synergistic effect on the inhibition of melanin biosynthesis with no corresponding effect on tyrosinase activity. Investigation of the possible mechanism of action revealed that chia seed extract downregulated expression of melanogenesis-related genes (Tyr, Tyrp1, and Mc1r), alone and in combination with pomegranate fruit extract, suggesting that the inhibition of melanin biosynthesis by a novel combination of chia seed and pomegranate fruit extracts is possibly due to the downregulation of gene expression of key melanogenic enzymes. Copyright © 2014 Elsevier B.V. All rights reserved.

Seasonal changes in epidermal ceramides are linked to impaired barrier function in acne patients.

PubMed

Pappas, Apostolos; Kendall, Alexandra C; Brownbridge, Luke C; Batchvarova, Nikoleta; Nicolaou, Anna

2018-01-21

Acne skin demonstrates increased transepidermal water loss (TEWL) compared with healthy skin, which may be due, in part, to altered ceramide (CER) levels. We analysed ceramides in the stratum corneum of healthy and acne skin, and studied seasonal variation over the course of a year. Using ultraperformance liquid chromatography with electrospray ionisation and tandem mass spectrometry (UPLC/ESI-MS/MS), we identified 283 ceramides. Acne-affected skin demonstrated overall lower levels of ceramides, with notable reductions in CER[NH] and CER[AH] ceramides, as well as the acylceramides CER[EOS] and CER[EOH]; these differences were more apparent in the winter months. Lower ceramide levels reflected an increase in TEWL in acne, compared with healthy skin, which partly resolves in the summer. Individual ceramide species with 18-carbon 6-hydroxysphingosine (H) bases (including CER[N(24)H(18)], CER[N(26)H(18)], CER[A(24)H(18)], CER[A(26)H(18)]) were significantly reduced in acne skin, suggesting that CER[NH] and CER[AH] species may be particularly important in a healthy skin barrier. © 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Isolation and functional assessment of cutaneous stem cells.

PubMed

Doucet, Yanne S; Owens, David M

2015-01-01

The epidermis and associated appendages of the skin represent a multi-lineage tissue that is maintained by perpetual rounds of renewal. During homeostasis, turnover of epidermal lineages is achieved by input from regionalized keratinocytes stem or progenitor populations with little overlap from neighboring niches. Over the last decade, molecular markers selectively expressed by a number of these stem or progenitor pools have been identified, allowing for the isolation and functional assessment of stem cells and genetic lineage tracing analysis within intact skin. These advancements have led to many fundamental observations about epidermal stem cell function such as the identification of their progeny, their role in maintenance of skin homeostasis, or their contribution to wound healing. In this chapter, we provide a methodology to identify and isolate epidermal stem cells and to assess their functional role in their respective niche. Furthermore, recent evidence has shown that the microenvironment also plays a crucial role in stem cell function. Indeed, epidermal cells are under the influence of surrounding fibroblasts, adipocytes, and sensory neurons that provide extrinsic signals and mechanical cues to the niche and contribute to skin morphogenesis and homeostasis. A better understanding of these microenvironmental cues will help engineer in vitro experimental models with more relevance to in vivo skin biology. New approaches to address and study these environmental cues in vitro will also be addressed.

Review: Pathogenesis of canine atopic dermatitis: skin barrier and host-micro-organism interaction.

PubMed

Santoro, Domenico; Marsella, Rosanna; Pucheu-Haston, Cherie M; Eisenschenk, Melissa N C; Nuttall, Tim; Bizikova, Petra

2015-04-01

Canine atopic dermatitis (AD) is a common, genetically predisposed, inflammatory and pruritic skin disease. The pathogenesis of canine AD is incompletely understood. The aim of this review is to provide an in-depth update on the involvement of skin barrier and host-microbiome interaction in the pathogenesis of canine AD. Online citation databases and abstracts from international meetings were searched for publications related to skin barrier and host-microbiome interaction (e.g. bacteria, yeast, antimicrobial peptides). A total of 126 publications were identified. This review article focuses on epidermal barrier dysfunction and the interaction between cutaneous microbes (bacteria and yeasts) and the host (antimicrobial peptides). Epidemiological updates on the presence of pathogenic organisms and canine AD are also provided. Major advances have been made in the investigation of skin barrier dysfunction in canine AD, although many questions still remain. Skin barrier dysfunction and host-microbiome interactions are emerging as primary alterations in canine AD. Based on this review, it is clear that future studies focused on the development of drugs able to restore the skin barrier and increase the natural defences against pathogenic organisms are needed. © 2015 ESVD and ACVD.

Roles of CONSTITUTIVE PHOTOMORPHOGENIC 10 in Arabidopsis stomata development

PubMed Central

Delgado, Dolores; Ballesteros, Isabel; Mena, Montaña; Fenoll, Carmen

2012-01-01

Stomata are epidermal bi-celled structures that differentiate within special cell lineages initiated by a subset of protodermal cells. Recently, we showed that the Arabidopsis photomorphogenic repressor COP10 controls specific cell-lineage and cell-signaling developmental mechanisms in stomatal lineages. Loss-of-function cop10-1 mutant cotyledons and leaves produced (in the light and in the dark) abundant stomatal clusters, but nonlineage epidermal cells were not affected. Here we examine COP10 role in hypocotyls, cylindrical organs displaying a distinct epidermal organization with alternate files of protruding and non-protruding cells, with the latter producing a limited number of stomata. COP10 prevents stomatal clusters and restricts stomata production in hypocotyls; these roles are specific to lineage cells as in cotyledons, since COP10 loss of function does not elicit stomatal fate in nonlineage cells; COP10 also sustains the directional cell expansion of all hypocotyl epidermal cell types, and seems necessary for the differentiation between protruding and non-protruding cell files. PMID:22836493

Vγ4 T Cells Inhibit the Pro-healing Functions of Dendritic Epidermal T Cells to Delay Skin Wound Closure Through IL-17A

PubMed Central

Li, Yashu; Wang, Yangping; Zhou, Lina; Liu, Meixi; Liang, Guangping; Yan, Rongshuai; Jiang, Yufeng; Hao, Jianlei; Zhang, Xiaorong; Hu, Xiaohong; Huang, Yong; Wang, Rupeng; Yin, Zhinan; Wu, Jun; Luo, Gaoxing; He, Weifeng

2018-01-01

Dendritic epidermal T cells (DETCs) and dermal Vγ4 T cells engage in wound re-epithelialization and skin inflammation. However, it remains unknown whether a functional link between Vγ4 T cell pro-inflammation and DETC pro-healing exists to affect the outcome of skin wound closure. Here, we revealed that Vγ4 T cell-derived IL-17A inhibited IGF-1 production by DETCs to delay skin wound healing. Epidermal IL-1β and IL-23 were required for Vγ4 T cells to suppress IGF-1 production by DETCs after skin injury. Moreover, we clarified that IL-1β rather than IL-23 played a more important role in inhibiting IGF-1 production by DETCs in an NF-κB-dependent manner. Together, these findings suggested a mechanistic link between Vγ4 T cell-derived IL-17A, epidermal IL-1β/IL-23, DETC-derived IGF-1, and wound-healing responses in the skin. PMID:29483920

p63 Adjusts Sugar Taste of Epidermal Layers.

PubMed

Amelio, Ivano; Melino, Gerry; Candi, Eleonora

2017-06-01

p63 is a master regulator of epidermal biology, sustaining stemness and renewal capacity of the proliferating keratinocyte compartment. Hamanaka and Mutlu propose that p63 regulates the keratinocyte proliferation/differentiation switch by affecting the cellular glycolic rate through a direct transcriptional regulation of the metabolic enzyme PFKFB3. This finding sheds light on mechanisms underlining p63 function in the skin and suggests a role for energetic metabolism in epidermal biology. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Epidermal Micromorphology and Mesophyll Structure of Populus euphratica Heteromorphic Leaves at Different Development Stages

PubMed Central

Liu, Yubing; Li, Xinrong; Chen, Guoxiong; Li, Mengmeng; Liu, Meiling; Liu, Dan

2015-01-01

Leaf epidermal micromorphology and mesophyll structure during the development of Populus euphratica heteromorphic leaves, including linear, lanceolate, ovate, dentate ovate, dentate rhombic, dentate broad-ovate and dentate fan-shaped leaves, were studied by using electron and light microscopy. During development of heteromorphic leaves, epidermal appendages (wax crystals and trichomes) and special cells (mucilage cells and crystal idioblasts) increased in all leaf types while chloroplast ultrastructure and stomatal characters show maximum photosynthetic activity in dentate ovate and rhombic leaves. Also, functional analysis by subordinate function values shows that the maximum adaptability to adverse stress was exhibited in the broad type of mature leaves. The 12 heteromorphic leaf types are classified into three major groups by hierarchical cluster analysis: young, developing and mature leaves. Mature leaves can effectively obtain the highest stress resistance by combining the protection of xerophytic anatomy from drought stress, regulation of water uptake in micro-environment by mucilage and crystal idioblasts, and assistant defense of transpiration reduction through leaf epidermal appendages, which improves photosynthetic activity under arid desert conditions. Our data confirms that the main leaf function is differentiated during the developing process of heteromorphic leaves. PMID:26356300

Epidermal Micromorphology and Mesophyll Structure of Populus euphratica Heteromorphic Leaves at Different Development Stages.

PubMed

Liu, Yubing; Li, Xinrong; Chen, Guoxiong; Li, Mengmeng; Liu, Meiling; Liu, Dan

2015-01-01

Leaf epidermal micromorphology and mesophyll structure during the development of Populus euphratica heteromorphic leaves, including linear, lanceolate, ovate, dentate ovate, dentate rhombic, dentate broad-ovate and dentate fan-shaped leaves, were studied by using electron and light microscopy. During development of heteromorphic leaves, epidermal appendages (wax crystals and trichomes) and special cells (mucilage cells and crystal idioblasts) increased in all leaf types while chloroplast ultrastructure and stomatal characters show maximum photosynthetic activity in dentate ovate and rhombic leaves. Also, functional analysis by subordinate function values shows that the maximum adaptability to adverse stress was exhibited in the broad type of mature leaves. The 12 heteromorphic leaf types are classified into three major groups by hierarchical cluster analysis: young, developing and mature leaves. Mature leaves can effectively obtain the highest stress resistance by combining the protection of xerophytic anatomy from drought stress, regulation of water uptake in micro-environment by mucilage and crystal idioblasts, and assistant defense of transpiration reduction through leaf epidermal appendages, which improves photosynthetic activity under arid desert conditions. Our data confirms that the main leaf function is differentiated during the developing process of heteromorphic leaves.

Polymeric membranes modulate human keratinocyte differentiation in specific epidermal layers.

PubMed

Salerno, Simona; Morelli, Sabrina; Giordano, Francesca; Gordano, Amalia; Bartolo, Loredana De

2016-10-01

In vitro models of human bioengineered skin substitutes are an alternative to animal experimentation for testing the effects and toxicity of drugs, cosmetics and pollutants. For the first time specific and distinct human epidermal strata were engineered by using membranes and keratinocytes. To this purpose, biodegradable membranes of chitosan (CHT), polycaprolactone (PCL) and a polymeric blend of CHT-PCL were prepared by phase-inversion technique and characterized in order to evaluate their morphological, physico-chemical and mechanical properties. The capability of membranes to modulate keratinocyte differentiation inducing specific interactions in epidermal membrane systems was investigated. The overall results demonstrated that the membrane properties strongly influence the cell morpho-functional behaviour of human keratinocytes, modulating their terminal differentiation, with the creation of specific epidermal strata or a fully proliferative epidermal multilayer system. In particular, human keratinocytes adhered on CHT and CHT-PCL membranes, forming the structure of the epidermal top layers, such as the corneum and granulosum strata, characterized by withdrawal or reduction from the cell cycle and cell proliferation. On the PCL membrane, keratinocytes developed an epidermal basal lamina, with high proliferating cells that stratified and migrated over time to form a complete differentiating epidermal multilayer system. Copyright © 2016 Elsevier B.V. All rights reserved.

Hybrid Enhanced Epidermal SpaceSuit Design Approaches

NASA Astrophysics Data System (ADS)

Jessup, Joseph M.

A Space suit that does not rely on gas pressurization is a multi-faceted problem that requires major stability controls to be incorporated during design and construction. The concept of Hybrid Epidermal Enhancement space suit integrates evolved human anthropomorphic and physiological adaptations into its functionality, using commercially available bio-medical technologies to address shortcomings of conventional gas pressure suits, and the impracticalities of MCP suits. The prototype HEE Space Suit explored integumentary homeostasis, thermal control and mobility using advanced bio-medical materials technology and construction concepts. The goal was a space suit that functions as an enhanced, multi-functional bio-mimic of the human epidermal layer that works in attunement with the wearer rather than as a separate system. In addressing human physiological requirements for design and construction of the HEE suit, testing regimes were devised and integrated into the prototype which was then subject to a series of detailed tests using both anatomical reproduction methods and human subject.

Intravital multiphoton tomography as a novel tool for non-invasive in vivo analysis of human skin affected with atopic dermatitis

NASA Astrophysics Data System (ADS)

Huck, Volker; Gorzelanny, Christian; Thomas, Kai; Niemeyer, Verena; Luger, Thomas A.; König, Karsten; Schneider, Stefan W.

2010-02-01

Atopic Dermatitis (AD) is an inflammatory disease of human skin. Its pathogenesis is still unknown; however, dysfunctions of the epidermal barrier and the immune response are regarded as key factors for the development of AD. In our study we applied intravital multiphoton tomography (5D-IVT), equipped with a spectral-FLIM module for in-vivo and ex-vivo analysis of human skin affected with AD. In addition to the morphologic skin analysis, FLIM technology gain access to the metabolic status of the epidermal cells referring to the NADH specific fluorescence lifetime. We evaluated a characteristic 5D-IVT skin pattern of AD in comparison to histological sections and detected a correlation with the disease activity measured by SCORAD. FLIM analysis revealed a shift of the mean fluorescence lifetime (taum) of NADH, indicating an altered metabolic activity. Within an ex-vivo approach we have investigated cryo-sections of human skin with or without barrier defects. Spectral-FLIM allows the detection of autofluorescent signals that reflect the pathophysiological conditions of the defect skin barrier. In our study the taum value was shown to be different between healthy and affected skin. Application of the 5D-IVT allows non-invasive in-vivo imaging of human skin with a penetration depth of 150 μm. We could show that affected skin could be distinguished from healthy skin by morphological criteria, by FLIM and by spectral-FLIM. Further studies will evaluate the application of the 5D-IVT technology as a diagnostic tool and to monitor the therapeutic efficacy.

SABRE is required for stabilization of root hair patterning in Arabidopsis thaliana.

PubMed

Pietra, Stefano; Lang, Patricia; Grebe, Markus

2015-03-01

Patterned differentiation of distinct cell types is essential for the development of multicellular organisms. The root epidermis of Arabidopsis thaliana is composed of alternating files of root hair and non-hair cells and represents a model system for studying the control of cell-fate acquisition. Epidermal cell fate is regulated by a network of genes that translate positional information from the underlying cortical cell layer into a specific pattern of differentiated cells. While much is known about the genes of this network, new players continue to be discovered. Here we show that the SABRE (SAB) gene, known to mediate microtubule organization, anisotropic cell growth and planar polarity, has an effect on root epidermal hair cell patterning. Loss of SAB function results in ectopic root hair formation and destabilizes the expression of cell fate and differentiation markers in the root epidermis, including expression of the WEREWOLF (WER) and GLABRA2 (GL2) genes. Double mutant analysis reveal that wer and caprice (cpc) mutants, defective in core components of the epidermal patterning pathway, genetically interact with sab. This suggests that SAB may act on epidermal patterning upstream of WER and CPC. Hence, we provide evidence for a role of SAB in root epidermal patterning by affecting cell-fate stabilization. Our work opens the door for future studies addressing SAB-dependent functions of the cytoskeleton during root epidermal patterning. © 2014 The Authors. Physiologia Plantarum published by John Wiley & Sons Ltd on behalf of Scandinavian Plant Physiology Society.

Clinical Experience and Best Practices Using Epidermal Skin Grafts on Wounds.

PubMed

Kirsner, Robert S; Bernstein, Brent; Bhatia, Animesh; Lantis, John; Le, Lam; Lincoln, Katherine; Liu, Paul; Rodgers, Lee; Shaw, Mark; Young, David

2015-11-01

Over the years, autologous skin grafting has been used extensively to achieve wound closure, optimize a functional scar, and improve aesthetic outcomes for the patient. Although a vast majority of the literature is on the use of full-thickness and split-thickness skin grafts, epidermal skin grafts (ESGs) have emerged as a viable option in the reconstructive ladder when only the epidermal layer is needed. These grafts are distinct from other types of autologous skin grafts in that they can be harvested without anesthesia and leave minimal or no scarring at the donor site. In order to explore the use of ESGs in the continuum of primary wound closure, a multidisciplinary expert panel convened in October 2014, in Las Vegas, NV, to review the scientific basis and clinical uses of epidermal grafting. This publication provides an overview of epidermal grafting, recommendations for graft application, and potential roles for its use in wound care and closure.

ABNORMAL POLLEN VACUOLATION1 (APV1) is required for male fertility by contributing to anther cuticle and pollen exine formation in maize.

PubMed

Somaratne, Yamuna; Tian, Youhui; Zhang, Hua; Wang, Mingming; Huo, Yanqing; Cao, Fengge; Zhao, Li; Chen, Huabang

2017-04-01

Anther cuticle and pollen exine are the major protective barriers against various stresses. The proper functioning of genes expressed in the tapetum is vital for the development of pollen exine and anther cuticle. In this study, we report a tapetum-specific gene, Abnormal Pollen Vacuolation1 (APV1), in maize that affects anther cuticle and pollen exine formation. The apv1 mutant was completely male sterile. Its microspores were swollen, less vacuolated, with a flat and empty anther locule. In the mutant, the anther epidermal surface was smooth, shiny, and plate-shaped compared with the three-dimensional crowded ridges and randomly formed wax crystals on the epidermal surface of the wild-type. The wild-type mature pollen had elaborate exine patterning, whereas the apv1 pollen surface was smooth. Only a few unevenly distributed Ubisch bodies were formed on the apv1 mutant, leading to a more apparent inner surface. A significant reduction in the cutin monomers was observed in the mutant. APV1 encodes a member of the P450 subfamily, CYP703A2-Zm, which contains 530 amino acids. APV1 appeared to be widely expressed in the tapetum at the vacuolation stage, and its protein signal co-localized with the endoplasmic reticulum (ER) signal. RNA-Seq data revealed that most of the genes in the fatty acid metabolism pathway were differentially expressed in the apv1 mutant. Altogether, we suggest that APV1 functions in the fatty acid hydroxylation pathway which is involved in forming sporopollenin precursors and cutin monomers that are essential for the development of pollen exine and anther cuticle in maize. © 2017 The Authors The Plant Journal © 2017 John Wiley & Sons Ltd.

Identification of acyltransferases required for cutin biosynthesis and production of cutin with suberin-like monomers.

PubMed

Li, Yonghua; Beisson, Fred; Koo, Abraham J K; Molina, Isabel; Pollard, Mike; Ohlrogge, John

2007-11-13

Cutin and suberin are the two major lipid-based polymers of plants. Cutin is the structural polymer of the epidermal cuticle, the waterproof layer covering primary aerial organs and which is often the structure first encountered by phytopathogens. Suberin contributes to the control of diffusion of water and solutes across internal root tissues and in periderms. The enzymes responsible for assembly of the cutin polymer are largely unknown. We have identified two Arabidopsis acyltransferases essential for cutin biosynthesis, glycerol-3-phosphate acyltransferase (GPAT) 4 and GPAT8. Double knockouts gpat4/gpat8 were strongly reduced in cutin and were less resistant to desiccation and to infection by the fungus Alternaria brassicicola. They also showed striking defects in stomata structure including a lack of cuticular ledges between guard cells, highlighting the importance of cutin in stomatal biology. Overexpression of GPAT4 or GPAT8 in Arabidopsis increased the content of C16 and C18 cutin monomers in leaves and stems by 80%. In order to modify cutin composition, the acyltransferase GPAT5 and the cytochrome P450-dependent fatty acyl oxidase CYP86A1, two enzymes associated with suberin biosynthesis, were overexpressed. When both enzymes were overexpressed together the epidermal polyesters accumulated new C20 and C22 omega-hydroxyacids and alpha,omega-diacids typical of suberin, and the fine structure and water-barrier function of the cuticle were altered. These results identify GPATs as partners of fatty acyl oxidases in lipid polyester synthesis and indicate that their cooverexpression provides a strategy to probe the role of cutin composition and quantity in the function of plant cuticles.

Identification of acyltransferases required for cutin biosynthesis and production of cutin with suberin-like monomers

PubMed Central

Li, Yonghua; Beisson, Fred; Koo, Abraham J. K.; Molina, Isabel; Pollard, Mike; Ohlrogge, John

2007-01-01

Cutin and suberin are the two major lipid-based polymers of plants. Cutin is the structural polymer of the epidermal cuticle, the waterproof layer covering primary aerial organs and which is often the structure first encountered by phytopathogens. Suberin contributes to the control of diffusion of water and solutes across internal root tissues and in periderms. The enzymes responsible for assembly of the cutin polymer are largely unknown. We have identified two Arabidopsis acyltransferases essential for cutin biosynthesis, glycerol-3-phosphate acyltransferase (GPAT) 4 and GPAT8. Double knockouts gpat4/gpat8 were strongly reduced in cutin and were less resistant to desiccation and to infection by the fungus Alternaria brassicicola. They also showed striking defects in stomata structure including a lack of cuticular ledges between guard cells, highlighting the importance of cutin in stomatal biology. Overexpression of GPAT4 or GPAT8 in Arabidopsis increased the content of C16 and C18 cutin monomers in leaves and stems by 80%. In order to modify cutin composition, the acyltransferase GPAT5 and the cytochrome P450-dependent fatty acyl oxidase CYP86A1, two enzymes associated with suberin biosynthesis, were overexpressed. When both enzymes were overexpressed together the epidermal polyesters accumulated new C20 and C22 ω-hydroxyacids and α,ω-diacids typical of suberin, and the fine structure and water-barrier function of the cuticle were altered. These results identify GPATs as partners of fatty acyl oxidases in lipid polyester synthesis and indicate that their cooverexpression provides a strategy to probe the role of cutin composition and quantity in the function of plant cuticles. PMID:17991776

Actin cable dynamics and Rho/Rock orchestrate a polarized cytoskeletal architecture in the early steps of assembling a stratified epithelium.

PubMed

Vaezi, Alec; Bauer, Christoph; Vasioukhin, Valeri; Fuchs, Elaine

2002-09-01

To enable stratification and barrier function, the epidermis must permit self-renewal while maintaining adhesive connections. By generating K14-GFP-actin mice to monitor actin dynamics in cultured primary keratinocytes, we uncovered a role for the actin cytoskeleton in establishing cellular organization. During epidermal sheet formation, a polarized network of nascent intercellular junctions and radial actin cables assemble in the apical plane of the monolayer. These actin fibers anchor to a central actin-myosin network, creating a tension-based plane of cytoskeleton across the apical surface of the sheet. Movement of the sheet surface relative to its base expands the zone of intercellular overlap, catalyzing new sites for nascent intercellular junctions. This polarized cytoskeleton is dependent upon alpha-catenin, Rho, and Rock, and its regulation may be important for wound healing and/or stratification, where coordinated tissue movements are involved.

Severe Demodex infestation of a coal miner.

PubMed

Toğral, Arzu Karataş; Altındal, Mahmut; Koryürek, Özgül Muştu; Tutkun, Engin; Yılmaz, Ömer Hınç

2013-01-01

We report a case of Demodex infestation in a 35 year old coal miner presenting with a 5 year history of scally papulopustular eruption on his face. He had been working inunderground coal tunnels in a humid- hot- dusty environment and he had been used to bath twice a day with hot water and multiple cleaners. The patient was treated successfully with oral metronidazol, topical permethrin, topical steroids and avoidance of undergraund mining . We believe his occupational environment made him prone to infestation by changes in sebum composition and/or viscosity, his bath habituation facilitated infestation, damaging the epidermal barrier function and his previous treatments exaggerated his infestation. During evaluation of the patient, specific occupational factors and habituations will be related with higher succession rates of treatment. We need to conduct further studies in order to draw a definite conclusion about the effect of the occupational environment on Demodex infestation.

Human epidermis is a novel site of phospholipase B expression.

PubMed

Maury, Eric; Prévost, Marie Claude; Nauze, Michel; Redoulès, Daniel; Tarroux, Roger; Charvéron, Marie; Salles, Jean Pierre; Perret, Bertrand; Chap, Hugues; Gassama-Diagne, Ama

2002-07-12

Phospholipase B (PLB) is an enzyme that displays both phospholipase A(2) and lysophospholipase activities. Analysis of human epidermis homogenates indicated the presence of a 97 kDa PLB protein, as well as a phospholipase A(2) activity, both being enriched in the soluble fraction. Immunolabelling and in situ hybridization experiments showed that this enzyme is expressed in the different layers of epidermis with an accumulation at the dermo-epidermis junction. RT-PCR data indicated that PLB is specifically expressed in natural and reconstructed epidermis. By 3'-RACE-PCR and screening of human genome databases, we obtained a 3600 bp cDNA coding for human PLB highly homologous to already described intestinal brush border PLBs. These data led us to conclude that the soluble PLB corresponds to a proteolytic cleavage of the membrane anchored protein. Altogether, our results provide the first characterization of human PLB which should play an important role in epidermal barrier function.

Filaggrin loss-of-function mutations are associated with food allergy in childhood and adolescence.

PubMed

Venkataraman, Devasmitha; Soto-Ramírez, Nelís; Kurukulaaratchy, Ramesh J; Holloway, John W; Karmaus, Wilfried; Ewart, Susan L; Arshad, S Hasan; Erlewyn-Lajeunesse, Mich

2014-10-01

Filaggrin is an epidermal protein that has a role in skin barrier function. Filaggrin loss-of-function (FLG-LOF) mutations are a significant risk factor for eczema and atopy, but their association with food allergy (FA) is less clear. We explored the longitudinal relationship between 3 common FLG-LOF mutations and FA using the Isle of Wight birth cohort. FA diagnosis was based on recognized allergic reactions within 4 hours after exposure to known food allergens. Food allergen sensitization (FAS) was identified by using skin prick tests conducted between 1 and 18 years of age to a range of food allergens. Three FLG mutations were genotyped in 1150 (79%) of 1456 children. The temporal relationships between FA, FAS, and eczema in children with FLG mutations were explored by using path analysis with total, direct, and indirect effect models. There was a significant total effect of FLG-LOF mutations on the risk of FA in later childhood at the ages of 10 (odds ratio, 31.46; 95% CI, 2.86 to >100) and 18 (odds ratio, 4.25; 95% CI, 1.55-11.61) years. Path analysis showed that there was no direct effect of FLG-LOF mutations on FA at any age; however, an indirect effect was found on FA at all ages through eczema and FAS in the earlier years. FLG-LOF mutations are associated with FA in older children through eczema and FAS during early childhood. Our results highlight a biologically plausible pathway, which suggests that skin barrier function is important in the development and persistence of FA. Copyright © 2014 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.

Regenerative and reparative effects of human chorion-derived stem cell conditioned medium on photo-aged epidermal cells

PubMed Central

Li, Qiankun; Chen, Yan; Ma, Kui; Zhao, Along; Zhang, Cuiping; Fu, Xiaobing

2016-01-01

ABSTRACT Epidermal cells are an important regenerative source for skin wound healing. Aged epidermal cells have a low ability to renew themselves and repair skin injury. Ultraviolet (UV) radiation, particularly UVB, can cause photo-aging of the skin by suppressing the viability of human epidermal cells. A chorion-derived stem cell conditioned medium (CDSC-CNM) is thought to have regenerative properties. This study aimed to determine the regenerative effects of CDSC-CNM on UVB-induced photo-aged epidermal cells. Epidermal cells were passaged four times and irradiated with quantitative UVB, and non-irradiated cells served as a control group. Cells were then treated with different concentrations of CDSC-CNM. Compared to the non-irradiated group, the proliferation rates and migration rates of UVB-induced photo-aged epidermal cells significantly decreased (p < 0.05) with increasing intracellular radical oxygen species (ROS) generation and DNA damage. After treatment with CDSC-CNM, photo-aged epidermal cells significantly improved their viability, and their ROS generation and DNA damage decreased. The secretory factors in CDSC-CNM, including epidermal growth factor (EGF), transforming growth factor-β (TGF-β), interleukin (IL)-6, and IL-8 and the related signaling pathway protein levels, increased compared to the control medium (CM). The potential regenerative and reparative effects of CDSC-CNM indicate that it may be a candidate material for the treatment of prematurely aged skin. The functions of the secretory factors and the mechanisms of CDSC-CNM therapy deserve further attention. PMID:27097375

Epidermal growth factor receptor and variant III targeted immunotherapy

PubMed Central

Congdon, Kendra L.; Gedeon, Patrick C.; Suryadevara, Carter M.; Caruso, Hillary G.; Cooper, Laurence J.N.; Heimberger, Amy B.; Sampson, John H.

2014-01-01

Immunotherapeutic approaches to cancer have shown remarkable promise. A critical barrier to successfully executing such immune-mediated interventions is the selection of safe yet immunogenic targets. As patient deaths have occurred when tumor-associated antigens shared by normal tissue have been targeted by strong cellular immunotherapeutic platforms, route of delivery, target selection and the immune-mediated approach undertaken must work together to maximize efficacy with safety. Selected tumor-specific targets can spare potential toxicity to normal tissue; however, they are far less common than tumor-associated antigens and may not be present on all patients. In the context of immunotherapy for high-grade glioma, 2 of the most prominently studied antigens are the tumor-associated epidermal growth factor receptor and its tumor-specific genetic deletion variant III. In this review, we will summarize the immune-mediated strategies employed against these targets as well as the caveats particular to these approaches. PMID:25342601

The effects of heat on skin barrier function and in vivo dermal absorption.

PubMed

Oliveira, Gabriela; Leverett, Jesse C; Emamzadeh, Mandana; Lane, Majella E

2014-04-10

Enhanced delivery of ingredients across the stratum corneum (SC) is of great interest for improving the efficacy of topically applied formulations. Various methods for improving dermal penetration have been reported including galvanic devices and micro-needles. From a safety perspective it is important that such approaches do not compromise SC barrier function. This study investigates the influence of topically applied heat in vivo on the dermal uptake and penetration of a model active, allantoin from gel and lotion formulations. A custom designed device was used to deliver 42°C for 30s daily to human subjects after application of two formulations containing allantoin. The results were compared with sites treated with formulations containing no active and no heat, and a control site. In addition to penetration of allantoin, the integrity of the SC was monitored using trans-epidermal water loss (TEWL) measurements. The results showed that just 30s of 42°C topically applied heat was enough to cause significantly more penetration of allantoin from the lotion formulation compared with no application of heat. TEWL data indicated that the integrity of the skin was not compromised by the treatment. However, the application of heat did not promote enhanced penetration of the active from the gel formulation. Vehicle composition is therefore an important factor when considering thermal enhancement strategies for targeting actives to the skin. Copyright © 2014 Elsevier B.V. All rights reserved.

Wax and cutin mutants of Arabidopsis: Quantitative characterization of the cuticular transport barrier in relation to chemical composition.

PubMed

Sadler, Christina; Schroll, Bettina; Zeisler, Viktoria; Waßmann, Friedrich; Franke, Rochus; Schreiber, Lukas

2016-09-01

Using (14)C-labeled epoxiconazole as a tracer, cuticular permeability of Arabidopsis thaliana leaves was quantitatively measured in order to compare different wax and cutin mutants (wax2, cut1, cer5, att1, bdg, shn3 and shn1) to the corresponding wild types (Col-0 and Ws). Mutants were characterized by decreases or increases in wax and/or cutin amounts. Permeances [ms(-1)] of Arabidopsis cuticles either increased in the mutants compared to wild type or were not affected. Thus, genetic changes in wax and cutin biosynthesis in some of the investigated Arabidopsis mutants obviously impaired the coordinated cutin and wax deposition at the outer leaf epidermal cell wall. As a consequence, barrier properties of cuticles were significantly decreased. However, increasing cutin and wax amounts by genetic modifications, did not automatically lead to improved cuticular barrier properties. As an alternative approach to the radioactive transport assay, changes in chlorophyll fluorescence were monitored after foliar application of metribuzine, an herbicide inhibiting electron transport in chloroplasts. Since both, half-times of photosynthesis inhibition as well as times of complete inhibition, in fact correlated with (14)C-epoxiconazole permeances, different rates of decline of photosynthetic yield between mutants and wild type must be a function of foliar uptake of the herbicide across the cuticle. Thus, monitoring changes in chlorophyll fluorescence, instead of conducting radioactive transport assays, represents an easy-to-handle and fast alternative evaluating cuticular barrier properties of different genotypes. This article is part of a Special Issue entitled: Plant Lipid Biology edited by Kent D. Chapman and Ivo Feussner. Copyright © 2016 Elsevier B.V. All rights reserved.

Shining Light on Skin Pigmentation: The Darker and the Brighter Side of Effects of UV Radiation†

PubMed Central

Maddodi, Nityanand; Jayanthy, Ashika; Setaluri, Vijayasaradhi

2012-01-01

The term barrier function as applied to human skin often connotes the physical properties of this organ that provide protection from its surrounding environment. This term does not generally include skin pigmentation. However, skin pigmentation, which is the result of melanin produced in melanocytes residing the basal layer of the skin and exported to the keratinocytes in the upper layers, serves equally important protective function. Indeed, changes in skin pigmentation are often the most readily recognized indicators of exposure of skin to damaging agents, especially to natural and artificial radiation in the environment. Several recent studies have shed new light on a) the mechanisms of involved in selective effects of subcomponents of UV radiation on human skin pigmentation and b) the interactive influences between keratinocytes and melanocytes, acting as ‘epidermal melanin unit’, that manifest as changes in skin pigmentation in response to exposure to various forms of radiation. This article provides a concise review of our current understanding of the effects of the non-ionizing solar radiation, at cellular and molecular levels, on human skin pigmentation. PMID:22404235

Generation of signaling specificity in Arabidopsis by spatially restricted buffering of ligand-receptor interactions.

PubMed

Abrash, Emily B; Davies, Kelli A; Bergmann, Dominique C

2011-08-01

Core signaling pathways function in multiple programs during multicellular development. The mechanisms that compartmentalize pathway function or confer process specificity, however, remain largely unknown. In Arabidopsis thaliana, ERECTA (ER) family receptors have major roles in many growth and cell fate decisions. The ER family acts with receptor TOO MANY MOUTHS (TMM) and several ligands of the EPIDERMAL PATTERNING FACTOR LIKE (EPFL) family, which play distinct yet overlapping roles in patterning of epidermal stomata. Here, our examination of EPFL genes EPFL6/CHALLAH (CHAL), EPFL5/CHALLAH-LIKE1, and EPFL4/CHALLAH-LIKE2 (CLL2) reveals that this family may mediate additional ER-dependent processes. chal cll2 mutants display growth phenotypes characteristic of er mutants, and genetic interactions are consistent with CHAL family molecules acting as ER family ligands. We propose that different classes of EPFL genes regulate different aspects of ER family function and introduce a TMM-based discriminatory mechanism that permits simultaneous, yet compartmentalized and distinct, function of the ER family receptors in growth and epidermal patterning.

Protein profiling of epidermal bladder cells from the halophyte Mesembryanthemum crystallinum.

PubMed

Barkla, Bronwyn J; Vera-Estrella, Rosario; Pantoja, Omar

2012-09-01

Plant epidermal trichomes are as varied in morphology as they are in function. In the halophyte Mesembryanthemum crystallinum, specialized trichomes called epidermal bladder cells (EBC) line the surface of leaves and stems, and increase dramatically in size and volume upon plant salt-treatment. These cells have been proposed to have roles in plant defense and UV protection, but primarily in sodium sequestration and as water reservoirs. To gain further understanding into the roles of EBC, a cell-type-specific proteomics approach was taken in which precision single-cell sampling of cell sap from individual EBC was combined with shotgun peptide sequencing (LC-MS/MS). Identified proteins showed diverse biological functions and cellular locations, with a high representation of proteins involved in H(+)-transport, carbohydrate metabolism, and photosynthesis. The proteome of EBC provides insight into the roles of these cells in ion and water homeostasis and raises the possibility that they are photosynthetically active and functioning in Crassulacean acid metabolism. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Epidermal E-Cadherin Dependent β-Catenin Pathway Is Phytochemical Inducible and Accelerates Anagen Hair Cycling.

PubMed

Ahmed, Noha S; Ghatak, Subhadip; El Masry, Mohamed S; Gnyawali, Surya C; Roy, Sashwati; Amer, Mohamed; Everts, Helen; Sen, Chandan K; Khanna, Savita

2017-11-01

Unlike the epidermis, which regenerates continually, hair follicles anchored in the subcutis periodically regenerate by spontaneous repetitive cycles of growth (anagen), degeneration (catagen), and rest (telogen). The loss of hair follicles in response to injuries or pathologies such as alopecia endangers certain inherent functions of the skin. Thus, it is of interest to understand mechanisms underlying follicular regeneration in adults. In this work, a phytochemical rich in the natural vitamin E tocotrienol (TRF) served as a productive tool to unveil a novel epidermal pathway of hair follicular regeneration. Topical TRF application markedly induced epidermal hair follicle development akin to that during fetal skin development. This was observed in the skin of healthy as well as diabetic mice, which are known to be resistant to anagen hair cycling. TRF suppressed epidermal E-cadherin followed by 4-fold induction of β-catenin and its nuclear translocation. Nuclear β-catenin interacted with Tcf3. Such sequestration of Tcf3 from its otherwise known function to repress pluripotent factors induced the plasticity factors Oct4, Sox9, Klf4, c-Myc, and Nanog. Pharmacological inhibition of β-catenin arrested anagen hair cycling by TRF. This work reports epidermal E-cadherin/β-catenin as a novel pathway capable of inducing developmental folliculogenesis in the adult skin. Copyright © 2017 The American Society of Gene and Cell Therapy. Published by Elsevier Inc. All rights reserved.

Enterocyte-specific epidermal growth factor prevents barrier dysfunction and improves mortality in murine peritonitis.

PubMed

Clark, Jessica A; Gan, Heng; Samocha, Alexandr J; Fox, Amy C; Buchman, Timothy G; Coopersmith, Craig M

2009-09-01

Systemic administration of epidermal growth factor (EGF) decreases mortality in a murine model of septic peritonitis. Although EGF can have direct healing effects on the intestinal mucosa, it is unknown whether the benefits of systemic EGF in peritonitis are mediated through the intestine. Here, we demonstrate that enterocyte-specific overexpression of EGF is sufficient to prevent intestinal barrier dysfunction and improve survival in peritonitis. Transgenic FVB/N mice that overexpress EGF exclusively in enterocytes (IFABP-EGF) and wild-type (WT) mice were subjected to either sham laparotomy or cecal ligation and puncture (CLP). Intestinal permeability, expression of the tight junction proteins claudins-1, -2, -3, -4, -5, -7, and -8, occludin, and zonula occludens-1; villus length; intestinal epithelial proliferation; and epithelial apoptosis were evaluated. A separate cohort of mice was followed for survival. Peritonitis induced a threefold increase in intestinal permeability in WT mice. This was associated with increased claudin-2 expression and a change in subcellular localization. Permeability decreased to basal levels in IFABP-EGF septic mice, and claudin-2 expression and localization were similar to those of sham animals. Claudin-4 expression was decreased following CLP but was not different between WT septic mice and IFABP-EGF septic mice. Peritonitis-induced decreases in villus length and proliferation and increases in apoptosis seen in WT septic mice did not occur in IFABP-EGF septic mice. IFABP-EGF mice had improved 7-day mortality compared with WT septic mice (6% vs. 64%). Since enterocyte-specific overexpression of EGF is sufficient to prevent peritonitis-induced intestinal barrier dysfunction and confers a survival advantage, the protective effects of systemic EGF in septic peritonitis appear to be mediated in an intestine-specific fashion.

Effects of adenosine 5'-monophosphate on epidermal turnover.

PubMed

Furukawa, Fukumi; Kanehara, Shoko; Harano, Fumiki; Shinohara, Shigeo; Kamimura, Junko; Kawabata, Shigekatsu; Igarashi, Sachiyo; Kawamura, Mitsuaki; Yamamoto, Yuki; Miyachi, Yoshiki

2008-10-01

The structure and function of the epidermis is maintained by cell renewal based on epidermal turnover. Epidermal turnover is delayed by aging, and it is thought that the delay of the epidermal turnover is a cause of aging alternation of skin. The epidermal turnover is related to the energy metabolism of epidermal basal cells. Adenosine 5'-triphosphate (ATP) is needed for cell renewal: cell division, and adenosine 5'-monophosphate (AMP) increases the amount of intracellular ATP. These findings suggest that AMP accelerates the epidermal turnover delayed by aging. This study investigated whether AMP and adenosine 5'-monophosphate disodium salt (AMP2Na) accelerates the epidermal turnover. An effect of AMP2Na on cell proliferation was examined by our counting of keratinocytes. An effect of AMP2Na on cell cycle was examined by our counting of basal cells in DNA synthetic period of hairless rats. The effects of AMP2Na (or AMP) on the epidermal turnover were examined by our measuring stratum corneum transit time by use of guinea pigs, and by our measuring stratum corneum surface area by use of hairless rats and in a clinical pharmacological study. The AMP2Na showed two different profiles on the proliferation of primary cultured keratinocytes. At a low concentration it induced cell growth, whereas at a high concentration it inhibited cell growth. The number of basal cells in the DNA synthetic period of AMP2Na was significantly higher than that of the vehicle in hairless rats. The stratum corneum transit time of AMP2Na was significantly shorter than that of the vehicle in guinea pigs. The corneocyte surface area of emulsion containing AMP2Na was significantly smaller than that of the vehicle in volunteers. We conclude that AMP promotes the cell proliferation and the cell cycle progression of epidermal basal cells and accelerates epidermal turnover safely. In addition, AMP is useful for skin rejuvenation in dermatology and aesthetic dermatology.

Assessing the Impact of Mechanical Damage on Full-Thickness Porcine and Human Skin Using an In Vitro Approach

PubMed Central

Builles, Nicolas; Frouin, Éric; Scott, Dan; Ramos, Jeanne; Marti-Mestres, Gilberte

2015-01-01

For most xenobiotics, the rates of percutaneous absorption are limited by diffusion through the horny layer of skin. However, percutaneous absorption of chemicals may seriously increase when the skin is damaged. The aim of this work was to develop an in vitro representative model of mechanically damaged skins. The epidermal barrier was examined following exposure to a razor, a rotating brush, and a microneedle system in comparison to tape-stripping which acted as a reference. Excised full-thickness skins were mounted on a diffusion chamber in order to evaluate the effect of injuries and to mimic physiological conditions. The transepidermal water loss (TEWL) was greatly increased when the barrier function was compromised. Measurements were made for all the damaged biopsies and observed histologically by microscopy. On human and porcine skins, the tape-stripping application (0 to 40 times) showed a proportional increase in TEWL which highlights the destruction of the stratum corneum. Similar results were obtained for all cosmetic instruments. This is reflected in our study by the nonsignificant difference of the mean TEWL scores between 30 strips and mechanical damage. For a specific appreciation, damaged skins were then selected to qualitatively evaluate the absorption of a chlorogenic acid solution using fluorescence microscopy. PMID:26247021

Cetuximab in the treatment of metastatic mucoepidermoid carcinoma of the salivary glands: A case report and review of literature

PubMed Central

Grisanti, Salvatore; Amoroso, Vito; Buglione, Michela; Rosati, Anna; Gatta, Roberto; Pizzocaro, Claudio; Ferrari, Vittorio D; Marini, Giovanni

2008-01-01

Introduction Patients with metastatic mucoepidermoid carcinoma of salivary glands have a poor outcome. The epidermal growth factor receptor protein is overexpressed in approximately 70% of mucoepidermoid carcinoma patients and may represent a therapeutic target. However, whether treatment with anti-epidermal growth factor receptor agents is effective is unclear and clinical trials are difficult due to the rarity of the disease. Here we assessed the activity of cetuximab in mucoepidermoid carcinoma on a molecular basis. Case presentation We present the case of a 40-year old Caucasian man with a mucoepidermoid carcinoma of the major salivary glands who developed distant bone and visceral metastases despite platinum-based chemotherapy. Epidermal growth factor receptor was overexpressed and fluorescence in situ hybridization analysis demonstrated a chromosome 7 polysomy. The patient was treated with the monoclonal antibody cetuximab in combination with cisplatin. After 11 doses of cetuximab, the patient developed brain metastases but evidence of response was documented at all extracranial metastatic sites. Conclusion This case report indicates that cetuximab can be active in mucoepidermoid carcinoma and may restore sensitivity to cisplatin in platinum-treated patients. Cetuximab does not cross the blood brain barrier and may select a metastatic clone to home the central nervous system while responding at other sites. PMID:18826647

Genetic Ablation of CCAAT/Enhancer Binding Protein α in Epidermis Reveals Its Role in Suppression of Epithelial Tumorigenesis

PubMed Central

Loomis, Kari D.; Zhu, Songyun; Yoon, Kyungsil; Johnson, Peter F.; Smart, Robert C.

2013-01-01

CCAAT/enhancer binding protein y (C/EBPα) is a basic leucine zipper transcription factor that inhibits cell cycle progression and regulates differentiation in various cell types. C/EBPα is inactivated by mutation in acute myeloid leukemia (AML) and is considered a human tumor suppressor in AML. Although C/EBPα mutations have not been observed in malignancies other than AML, greatly diminished expression of C/EBPα occurs in numerous human epithelial cancers including lung, liver, endometrial, skin, and breast, suggesting a possible tumor suppressor function. However, direct evidence for C/EBPα as an epithelial tumor suppressor is lacking due to the absence of C/EBPα mutations in epithelial tumors and the lethal effect of C/EBPα deletion in mouse model systems. To examine the function of C/EBPα in epithelial tumor development, an epidermal-specific C/EBPα knockout mouse was generated. The epidermal-specific C/EBPα knockout mice survived and displayed no detectable abnormalities in epidermal keratinocyte proliferation, differentiation, or apoptosis, showing that C/EBPα is dispensable for normal epidermal homeostasis. In spite of this, the epidermal-specific C/EBPα knockout mice were highly susceptible to skin tumor development involving oncogenic Ras. These mice displayed decreased tumor latency and striking increases in tumor incidence, multiplicity, growth rate, and the rate of malignant progression. Mice hemizygous for C/EBPα displayed an intermediate-enhanced tumor phenotype. Our results suggest that decreased expression of C/EBPα contributes to deregulation of tumor cell proliferation. C/EBPα had been proposed to block cell cycle progression through inhibition of E2F activity. We observed that C/EBPα blocked Ras-induced and epidermal growth factor-induced E2F activity in keratinocytes and also blocked Ras-induced cell transformation and cell cycle progression. Our study shows that C/EBPα is dispensable for epidermal homeostasis and provides genetic evidence that C/EBPα is a suppressor of epithelial tumorigenesis. PMID:17638888

IFI27, a novel epidermal growth factor-stabilized protein, is functionally involved in proliferation and cell cycling of human epidermal keratinocytes.

PubMed

Hsieh, W-L; Huang, Y-H; Wang, T-M; Ming, Y-C; Tsai, C-N; Pang, J-H S

2015-04-01

IFI27 is highly expressed in psoriatic lesions but its function has not been known. The present study aimed to explore its role in proliferation of epidermal keratinocytes. IFI27 knockdown and over-expression in keratinocytes were used to compare their proliferation, by MTT assay, apoptosis (by annexin V binding) and cell cycle progression by flow cytometry. Formation of cyclin A/CDK1 complex was examined by a co-immunoprecipitaion method. Anti-proliferation effects of IFI27 were also examined in vivo by topical application of IFI27 siRNA on imiquimod-induced psoriatic lesions, in a mouse model. Epidermal growth factor was demonstrated to increase IFI27 expression by prolonging half-life of IFI27 protein. The IFI27 knockdown in keratinocytes reduced the proliferation rate, but had no effect on apoptosis nor on apoptosis-related genes. Interestingly, IFI27 knockdown resulted in S-phase arrest that was found to be associated with increased Tyr15 phosphorylation of CDK1, reduced CDC25B and reduced formation of cyclin A/CDK1 complex. In addition, IFI27 knockdown was also shown to activate p53 by Ser15 phosphorylation and increase p21 expression. Topical application of IFI27 siRNA on imiquimod-induced psoriatic lesion in a mouse model reduced epidermal thickness, formation of rete ridges and PCNA expression. Our study demonstrates for the first time, that cell function of IFI27 is involved in proliferation of skin keratinocytes both in vitro and in vivo. It suggests that IFI27 might be a suitable target for development of a novel anti-psoriasis therapy. © 2015 John Wiley & Sons Ltd.

Dermocosmetics for dry skin: a new role for botanical extracts.

PubMed

Casetti, F; Wölfle, U; Gehring, W; Schempp, C M

2011-01-01

Dry skin is associated with a disturbed skin barrier and reduced formation of epidermal proteins and lipids. During recent years, skin-barrier-reinforcing properties of some botanical compounds have been described. Searching the PubMed database revealed 9 botanical extracts that specifically improve skin barrier and/or promote keratinocyte differentiation in vivo after topical application. The topical application of Aloe vera (leaf gel), Betula alba (birch bark extract), Helianthus annuus (sunflower oleodistillate), Hypericum perforatum (St. John's wort extract), Lithospermum erythrorhizon (root extract), Piptadenia colubrina (angico-branco extract) and Simarouba amara (bitter wood extract) increased skin hydration, reduced the transepidermal water loss, or promoted keratinocyte differentiation in humans in vivo. The topical application of Rubia cordifolia root extract and rose oil obtained from Rosa spp. flowers stimulated keratinocyte differentiation in mouse models. The underlying mechanisms of these effects are discussed. It is concluded that some botanical compounds display skin-barrier-reinforcing properties that may be used in dermocosmetics for dry skin. However, more investigations on the mode of action and more vehicle-controlled studies are required. Copyright © 2011 S. Karger AG, Basel.

Extracellular Matrix as a Regulator of Epidermal Stem Cell Fate.

PubMed

Chermnykh, Elina; Kalabusheva, Ekaterina; Vorotelyak, Ekaterina

2018-03-27

Epidermal stem cells reside within the specific anatomic location, called niche, which is a microenvironment that interacts with stem cells to regulate their fate. Regulation of many important processes, including maintenance of stem cell quiescence, self-renewal, and homeostasis, as well as the regulation of division and differentiation, are common functions of the stem cell niche. As it was shown in multiple studies, extracellular matrix (ECM) contributes a lot to stem cell niches in various tissues, including that of skin. In epidermis, ECM is represented, primarily, by a highly specialized ECM structure, basement membrane (BM), which separates the epidermal and dermal compartments. Epidermal stem cells contact with BM, but when they lose the contact and migrate to the overlying layers, they undergo terminal differentiation. When considering all of these factors, ECM is of fundamental importance in regulating epidermal stem cells maintenance, proper mobilization, and differentiation. Here, we summarize the remarkable progress that has recently been made in the research of ECM role in regulating epidermal stem cell fate, paying special attention to the hair follicle stem cell niche. We show that the destruction of ECM components impairs epidermal stem cell morphogenesis and homeostasis. A deep understanding of ECM molecular structure as well as the development of in vitro system for stem cell maintaining by ECM proteins may bring us to developing new approaches for regenerative medicine.

Adding a Piece to the Leaf Epidermal Cell Shape Puzzle.

PubMed

von Wangenheim, Daniel; Wells, Darren M; Bennett, Malcolm J

2017-11-06

The jigsaw puzzle-shaped pavement cells in the leaf epidermis collectively function as a load-bearing tissue that controls organ growth. In this issue of Developmental Cell, Majda et al. (2017) shed light on how the jigsaw shape can arise from localized variations in wall stiffness between adjacent epidermal cells. Copyright © 2017 Elsevier Inc. All rights reserved.

Real-time visualization of macromolecule uptake by epidermal Langerhans cells in living animals.

PubMed

Frugé, Rachel E; Krout, Colleen; Lu, Ran; Matsushima, Hironori; Takashima, Akira

2012-03-01

As a skin-resident member of the dendritic cell family, Langerhans cells (LCs) are generally regarded to function as professional antigen-presenting cells. Here we report a simple method to visualize the endocytotic activity of LCs in living animals. BALB/c mice received subcutaneous injection of FITC-conjugated dextran (DX) probes into the ear skin and were then examined under confocal microscopy. Large numbers of FITC(+) epidermal cells became detectable 12-24 hours after injection as background fluorescence signals began to disappear. Most (>90%) of the FITC(+) epidermal cells expressed Langerin, and >95% of Langerin(+) epidermal cells exhibited significant FITC signals. To assess intracellular localization, Alexa Fluor 546-conjugated DX probes were locally injected into IAβ-enhanced green fluorescent protein (EGFP) knock-in mice and Langerin-EGFP-diphtheria toxin receptor mice--three dimensional rotation images showed close association of most of the internalized DX probes with major histocompatibility complex (MHC) class II molecules, but not with Langerin molecules. These observations support the current view that LCs constantly sample surrounding materials, including harmful and innocuous antigens, at the environmental interface. Our data also validate the potential utility of the newly developed imaging approach to monitor LC function in wild-type animals.

Increased retinoic acid levels through ablation of Cyp26b1 determine the processes of embryonic skin barrier formation and peridermal development

PubMed Central

Okano, Junko; Lichti, Ulrike; Mamiya, Satoru; Aronova, Maria; Zhang, Guofeng; Yuspa, Stuart H.; Hamada, Hiroshi; Sakai, Yasuo; Morasso, Maria I.

2012-01-01

The process by which the periderm transitions to stratified epidermis with the establishment of the skin barrier is unknown. Understanding the cellular and molecular processes involved is crucial for the treatment of human pathologies, where abnormal skin development and barrier dysfunction are associated with hypothermia and perinatal dehydration. For the first time, we demonstrate that retinoic acid (RA) levels are important for periderm desquamation, embryonic skin differentiation and barrier formation. Although excess exogenous RA has been known to have teratogenic effects, little is known about the consequences of elevated endogenous retinoids in skin during embryogenesis. Absence of cytochrome P450, family 26, subfamily b, polypeptide 1 (Cyp26b1), a retinoic-acid-degrading enzyme, results in aberrant epidermal differentiation and filaggrin expression, defective cornified envelopes and skin barrier formation, in conjunction with peridermal retention. We show that these alterations are RA dependent because administration of exogenous RA in vivo and to organotypic skin cultures phenocopy Cyp26b1−/− skin abnormalities. Furthermore, utilizing the Flaky tail (Ft/Ft) mice, a mouse model for human ichthyosis, characterized by mutations in the filaggrin gene, we establish that proper differentiation and barrier formation is a prerequisite for periderm sloughing. These results are important in understanding pathologies associated with abnormal embryonic skin development and barrier dysfunction. PMID:22366455

Gloss, colour and grip: multifunctional epidermal cell shapes in bee- and bird-pollinated flowers.

PubMed

Papiorek, Sarah; Junker, Robert R; Lunau, Klaus

2014-01-01

Flowers bear the function of filters supporting the attraction of pollinators as well as the deterrence of floral antagonists. The effect of epidermal cell shape on the visual display and tactile properties of flowers has been evaluated only recently. In this study we quantitatively measured epidermal cell shape, gloss and spectral reflectance of flowers pollinated by either bees or birds testing three hypotheses: The first two hypotheses imply that bee-pollinated flowers might benefit from rough surfaces on visually-active parts produced by conical epidermal cells, as they may enhance the colour signal of flowers as well as the grip on flowers for bees. In contrast, bird-pollinated flowers might benefit from flat surfaces produced by flat epidermal cells, by avoiding frequent visitation from non-pollinating bees due to a reduced colour signal, as birds do not rely on specific colour parameters while foraging. Moreover, flat petal surfaces in bird-pollinated flowers may hamper grip for bees that do not touch anthers and stigmas while consuming nectar and thus, are considered as nectar thieves. Beside this, the third hypothesis implies that those flower parts which are vulnerable to nectar robbing of bee- as well as bird-pollinated flowers benefit from flat epidermal cells, hampering grip for nectar robbing bees. Our comparative data show in fact that conical epidermal cells are restricted to visually-active parts of bee-pollinated flowers, whereas robbing-sensitive parts of bee-pollinated as well as the entire floral surface of bird-pollinated flowers possess on average flat epidermal cells. However, direct correlations between epidermal cell shape and colour parameters have not been found. Our results together with published experimental studies show that epidermal cell shape as a largely neglected flower trait might act as an important feature in pollinator attraction and avoidance of antagonists, and thus may contribute to the partitioning of flower-visitors.

Basic Fibroblast Growth Factor Influences Epidermal Homeostasis of Living Skin Equivalents through Affecting Fibroblast Phenotypes and Functions.

PubMed

Yang, Lujun; Zhang, Dangui; Wu, Hongjuan; Xie, Sitian; Zhang, Mingjun; Zhang, Bingna; Tang, Shijie

2018-05-30

To elucidate the possible mechanisms of how basic fibroblast growth factor (bFGF) influences epidermal homeostasis in a living skin equivalent (LSE) model. Several wound healing-related growth factors were analyzed at protein and mRNA levels for dermal fibroblasts of induced alpha-smooth muscle actin (α-SMA)-positive or α-SMA-negative phenotypes. During culturing an LSE model by seeding normal human keratinocytes on a fibroblast-populated type I collagen gel, bFGF or neutralizing antibody for keratinocyte growth factor (KGF) was added to investigate its effects on fibroblast phenotypes and, subsequently, epidermal homeostasis by histology and immunohistochemistry. The α-SMA-positive phenotype of fibroblasts induced by transforming growth factor beta-1 (TGF-β1) markedly suppressed the expression of KGF and hepatocyte growth factor (HGF), and slightly upregulated vascular endothelial growth factor (VEGF) and TGF-β1 at mRNA and protein levels, compared with α-SMA-negative fibroblasts treated with bFGF. α-SMA expression of fibroblasts at the epidermal-mesenchymal junction of the LSEs was suppressed by the addition of bFGF, and a better-differentiated epidermis was presented. The abrogation of KGF from fibroblasts by the addition of the KGF neutralizing antibody disenabled the LSE culturing system to develop an epidermis. bFGF, through affecting the phenotypes and functions of fibroblasts, especially KGF expression, influenced epidermal homeostasis in an LSE model. © 2018 S. Karger AG, Basel.

[Atopic dermatitis physiopathology].

PubMed

Waton, J

2017-12-01

Our understanding of the physiopathology of atopic dermatitis has much improved over the recent years. Epidermal barrier alterations are integrated into 2 theories called inside out and outside in. They are related to complex immune abnormalities. Understanding their mechanism makes it possible to foresee new therapeutics. Moreover, environmental biodiversity, the diversity of cutaneous microbiota and genetic predispositions in atopic dermatitis lead to a new, more comprehensive theory, « the biodiversity theory », integrating epigenetics. © 2017 Elsevier Masson SAS. Tous droits réservés.

Improving diaper design to address incontinence associated dermatitis

PubMed Central

2010-01-01

Background Incontinence associated dermatitis (IAD) is an inflammatory skin disease mainly triggered by prolonged skin contact with urine, feces but also liberal detergent use when cleansing the skin. To minimize the epidermal barrier challenge we optimized the design of adult incontinence briefs. In the fluid absorption area we interposed a special type of acidic, curled-type of cellulose between the top sheet in contact with the skin and the absorption core beneath containing the polyacrylate superabsorber. The intention was to minimize disturbance of the already weak acid mantle of aged skin. We also employed air-permeable side panels to minimize skin occlusion and swelling of the stratum corneum. Methods The surface pH of diapers was measured after repeated wetting with a urine substitute fluid at the level of the top sheet. Occlusive effects and hydration of the stratum corneum were measured after a 4 hour application of different side panel materials by corneometry on human volunteers. Finally, we evaluated skin symptoms in 12 patients with preexisting IAD for 21 days following the institutional switch to the optimized diaper design. Local skin care protocols remained in place unchanged. Results The improved design created a surface pH of 4.6 which was stable even after repeated wetting throughout a 5 hour period. The "standard design" briefs had values of 7.1, which is alkaline compared to the acidic surface of normal skin. Side panels made from non-woven material with an air-permeability of more than 1200 l/m2/s avoided excessive hydration of the stratum corneum when compared to the commonly employed air-impermeable plastic films. Resolution of pre-existing IAD skin lesions was noted in 8 out of 12 patients after the switch to the optimized brief design. Conclusions An improved design of adult-type briefs can create an acidic pH on the surface and breathable side panels avoid over-hydration of the stratum corneum and occlusion. This may support the epidermal barrier function and may help to reduce the occurrence of IAD. PMID:21092161

ZNF750 is a p63 Target Gene that Induces KLF4 to Drive Terminal Epidermal Differentiation

PubMed Central

Sen, George L.; Boxer, Lisa D.; Webster, Dan E.; Bussat, Rose T.; Qu, Kun; Zarnegar, Brian J.; Johnston, Danielle; Siprashvili, Zurab; Khavari, Paul A.

2012-01-01

SUMMARY Disrupted epidermal differentiation characterizes numerous diseases that impact >25% of the population. In a search for dominant mediators of differentiation, we defined a requirement for ZNF750 in terminal epidermal differentiation. ZNF750 controlled genes mutated in numerous human skin diseases, including FLG, LOR, LCE3B, ALOXE3, and SPINK5. ZNF750 induced progenitor differentiation via an evolutionarily conserved C2H2 zinc finger motif. The epidermal master regulator, p63, bound the ZNF750 promoter and was necessary for its induction. ZNF750 restored differentiation to p63-deficient tissue, suggesting it acts downstream of p63. A search for functionally important ZNF750 targets via analysis of ZNF750-regulated genes identified KLF4, a transcription factor that activates late epidermal differentiation. ZNF750 binds to KLF4 at multiple sites flanking the transcriptional start site and controls its expression. ZNF750 thus directly links a tissue-specifying factor, p63, to an effector of terminal differentiation, KLF4, and represents a potential future target for disorders of this process. PMID:22364861

Epidermal skin grafting in vitiligo: a pilot study.

PubMed

Janowska, Agata; Dini, Valentina; Panduri, Salvatore; Macchia, Michela; Oranges, Teresa; Romanelli, Marco

2016-09-01

Vitiligo is a multifactorial acquired dermatosis characterised by achromic or hypochromic macules and by the absence of functioning melanocytes. Treatment depends on the extent of the affected areas and on disease activity. Surgical techniques have proven to be effective in stable cases but can be time-consuming and, in some cases, aesthetically unsatisfying or painful for the patients. The aim of the study was to assess the clinical safety and effectiveness of a new automatic epidermal skin harvesting device in patients with stable localised vitiligo over a minimum 12-month period. This new system (CELLUTOME™ Epidermal Harvesting System, KCI, an ACELITY Company, San Antonio, TX) is a commercially available epidermal skin harvesting system that can be used without local anaesthesia or other pre-treatments and has been shown to have low rates of donor site morbidity. Epidermal skin grafts can used in patients with acute and hard to heal chronic wounds, burns and stable vitiligo. The use of advanced therapies may improve the quality of life, have cost benefits and accelerate re-pigmentation of patients with vitiligo. In our preliminary study, this system was seen to be a safe and efficacious means of harvesting epidermal micrografts containing melanocytes for use in patients with stable vitiligo unresponsive to standard therapies. © 2016 Medicalhelplines.com Inc and John Wiley & Sons Ltd.

Daily intake of Jeju groundwater improves the skin condition of the model mouse for human atopic dermatitis.

PubMed

Tanaka, Akane; Jung, Kyungsook; Matsuda, Akira; Jang, Hyosun; Kajiwara, Naoki; Amagai, Yosuke; Oida, Kumiko; Ahn, Ginnae; Ohmori, Keitaro; Kang, Kyung-goo; Matsuda, Hiroshi

2013-03-01

Drinking water is an important nutrient for human health. The mineral ingredients included in drinking water may affect the physical condition of people. Various kinds of natural water are in circulation as bottled water in developed countries; however, its influence on clinical conditions of patients with certain diseases has not been fully evaluated. In this study, effects of the natural groundwater from Jeju Island on clinical symptoms and skin barrier function in atopic dermatitis (AD) were evaluated. NC/Tnd mice, a model for human AD, with moderate to severe dermatitis were used. Mice were given different natural groundwater or tap water for 8 weeks from 4 weeks of age. Clinical skin severity scores were recorded every week. Scratching analysis and measurement of transepidermal water loss were performed every other week. The pathological condition of the dorsal skin was evaluated histologically. Real-time polymerase chain reaction analysis was performed for cytokine expression in the affected skin. The epidermal hyperplasia and allergic inflammation were reduced in atopic mice supplied with Jeju groundwater when compared to those supplied with tap water or other kinds of natural groundwater. The increase in scratching behavior with the aggravation of clinical severity of dermatitis was favorably controlled. Moreover, transepidermal water loss that reflects skin barrier function was recovered. The early inflammation and hypersensitivity in the atopic skin was alleviated in mice supplied with Jeju groundwater, suggesting its profitable potential on the daily care of patients with skin troubles including AD. © 2013 Japanese Dermatological Association.

Directing Adipose-Derived Stem Cells into Keratinocyte-Like Cells: Impact of Medium Composition and Culture Condition.

PubMed

Petry, L; Kippenberger, S; Meissner, M; Kleemann, J; Kaufmann, R; Rieger, U M; Wellenbrock, S; Reichenbach, G; Zöller, N; Valesky, E

2018-04-28

Adipose-derived stem cells (ASC) are known to transdifferentiate into a wide range of different cell species in vitro including along the epidermal lineage. This property makes them a promising tool for regenerative medicine in order to restore the epidermal barrier. The present study is dedicated to identify in vitro conditions enabling transdifferentiation to a keratinocyte-like phenotype. Especially, the impact of different culture conditions (media compositions, 2D-, 3D-cultures) and extracellular matrix (ECM) molecules was evaluated. ASC derived from subcutaneous abdominal fat were characterized by stemness associated markers and subjected to different media. Epithelial differentiation in 2D cultures was monitored by pan-cytokeratin expression using flow cytometry and immunocytochemistry. In order to evaluate the impact of different ECM molecules on epidermal stratification, 3D cultures were produced, lifted to the air-liquid-interface (ALI) and examined by histological analysis and quantitative real-time RT-PCR. We identified a medium composition containing retinoic acid, hydrocortisone, ascorbic acid and BMP-4 enabling maximum pan-cytokeratin expression in 2D cultures. Moreover, adhesion to type IV collagen further promotes the pan-cytokeratin expression. When cultures were lifted to the ALI, significant stratification was observed, particularly in supports coated with type IV collagen or fibronectin. Moreover, epidermal differentiation markers (involucrin, cytokeratin 1 and 14) become induced. Conditions with hampered wound healing such as non-healing ulcers demand new treatment regimes. The here introduced optimized protocols for transdifferentiation of ASC into keratinocyte-like cells may help to establish more effective treatment procedures. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Antimicrobial peptides and pro-inflammatory cytokines are differentially regulated across epidermal layers following bacterial stimuli.

PubMed

Percoco, Giuseppe; Merle, Chloé; Jaouen, Thomas; Ramdani, Yasmina; Bénard, Magalie; Hillion, Mélanie; Mijouin, Lily; Lati, Elian; Feuilloley, Marc; Lefeuvre, Luc; Driouich, Azeddine; Follet-Gueye, Marie-Laure

2013-12-01

The skin is a natural barrier between the body and the environment and is colonised by a large number of microorganisms. Here, we report a complete analysis of the response of human skin explants to microbial stimuli. Using this ex vivo model, we analysed at both the gene and protein level the response of epidermal cells to Staphylococcus epidermidis (S. epidermidis) and Pseudomonas fluorescens (P. fluorescens), which are present in the cutaneous microbiota. We showed that both bacterial species affect the structure of skin explants without penetrating the living epidermis. We showed by real-time quantitative polymerase chain reaction (qPCR) that S. epidermidis and P. fluorescens increased the levels of transcripts that encode antimicrobial peptides (AMPs), including human β defensin (hBD)2 and hBD3, and the pro-inflammatory cytokines interleukin (IL)-1α and (IL)-1-β, as well as IL-6. In addition, we analysed the effects of bacterial stimuli on the expression profiles of genes related to innate immunity and the inflammatory response across the epidermal layers, using laser capture microdissection (LCM) coupled to qPCR. We showed that AMP transcripts were principally upregulated in suprabasal keratinocytes. Conversely, the expression of pro-inflammatory cytokines was upregulated in the lower epidermis. These findings were confirmed by protein localisation using specific antibodies coupled to optical or electron microscopy. This work underscores the potential value of further studies that use LCM on human skin explants model to study the roles and effects of the epidermal microbiota on human skin physiology. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Characterization of Fetal Keratinocytes, Showing Enhanced Stem Cell-Like Properties: A Potential Source of Cells for Skin Reconstruction

PubMed Central

Tan, Kenneth K.B.; Salgado, Giorgiana; Connolly, John E.; Chan, Jerry K.Y.; Lane, E. Birgitte

2014-01-01

Summary Epidermal stem cells have been in clinical application as a source of culture-generated grafts. Although applications for such cells are increasing due to aging populations and the greater incidence of diabetes, current keratinocyte grafting technology is limited by immunological barriers and the time needed for culture amplification. We studied the feasibility of using human fetal skin cells for allogeneic transplantation and showed that fetal keratinocytes have faster expansion times, longer telomeres, lower immunogenicity indicators, and greater clonogenicity with more stem cell indicators than adult keratinocytes. The fetal cells did not induce proliferation of T cells in coculture and were able to suppress the proliferation of stimulated T cells. Nevertheless, fetal keratinocytes could stratify normally in vitro. Experimental transplantation of fetal keratinocytes in vivo seeded on an engineered plasma scaffold yielded a well-stratified epidermal architecture and showed stable skin regeneration. These results support the possibility of using fetal skin cells for cell-based therapeutic grafting. PMID:25254345

Functional electrical stimulation-facilitated proliferation and regeneration of neural precursor cells in the brains of rats with cerebral infarction

PubMed Central

Xiang, Yun; Liu, Huihua; Yan, Tiebin; Zhuang, Zhiqiang; Jin, Dongmei; Peng, Yuan

2014-01-01

Previous studies have shown that proliferation of endogenous neural precursor cells cannot alone compensate for the damage to neurons and axons. From the perspective of neural plasticity, we observed the effects of functional electrical stimulation treatment on endogenous neural precursor cell proliferation and expression of basic fibroblast growth factor and epidermal growth factor in the rat brain on the infarct side. Functional electrical stimulation was performed in rat models of acute middle cerebral artery occlusion. Simultaneously, we set up a placebo stimulation group and a sham-operated group. Immunohistochemical staining showed that, at 7 and 14 days, compared with the placebo group, the numbers of nestin (a neural precursor cell marker)-positive cells in the subgranular zone and subventricular zone were increased in the functional electrical stimulation treatment group. Western blot assays and reverse-transcription PCR showed that total protein levels and gene expression of epidermal growth factor and basic fibroblast growth factor were also upregulated on the infarct side. Prehensile traction test results showed that, at 14 days, prehension function of rats in the functional electrical stimulation group was significantly better than in the placebo group. These results suggest that functional electrical stimulation can promote endogenous neural precursor cell proliferation in the brains of acute cerebral infarction rats, enhance expression of basic fibroblast growth factor and epidermal growth factor, and improve the motor function of rats. PMID:25206808

A Review of Indigo Naturalis as an Alternative Treatment for Nail Psoriasis.

PubMed

McDermott, Laura; Madan, Raman; Rupani, Reena; Siegel, Daniel

2016-03-01

Nail psoriasis is challenging to treat. The few currently available therapies are limited in efficacy, and often produce unfavorable side effects. A plant extract widely used in Traditional Chinese Medicine, indigo naturalis (Qing Dai), is presented in this review as an alternative topical treatment for skin and nail psoriasis. The purpose of this article is to present information on a viable alternative treatment with a favorable side effect profile for a difficult disease to treat. A PubMed search for the term "indigo naturalis" was performed, and literature from 2006 to the present relevant to indigo naturalis and treatment of psoriasis and nail psoriasis was reviewed. Indigo naturalis shares several therapeutic mechanisms with current psoriasis treatments, such as regulation of keratinocyte proliferation and differentiation, restoration of epidermal barrier function, and reduction of inflammatory processes. Clinically, it is well tolerated. Recent research of indigo naturalis suggests that it is a safe, inexpensive, and effective alternative topical treatment for skin and nail psoriasis.

Effects of Collagen Tripeptide Supplement on Photoaging and Epidermal Skin Barrier in UVB-exposed Hairless Mice.

PubMed

Pyun, Hee-Bong; Kim, Minji; Park, Jieun; Sakai, Yasuo; Numata, Noriaki; Shin, Jin-Yeong; Shin, Hyun-Jung; Kim, Do-Un; Hwang, Jae-Kwan

2012-12-01

Collagen tripeptide (CTP) is a functional food material with several biological effects such as improving dry skin and wound and bone fracture healing. This study focused on the anti-photoaging effects of CTP on a hairless mouse model. To evaluate the effects of CTP on UVB-induced skin wrinkle formation in vivo, the hairless mice were exposed to UVB radiation with oral administration of CTP for 14 weeks. Compared with the untreated UVB control group, mice treated with CTP showed significantly reduced wrinkle formation, skin thickening, and transepidermal water loss (TEWL). Skin hydration and hydroxyproline were increased in the CTP-treated group. Moreover, oral administration of CTP prevented UVB-induced MMP-3 and -13 activities as well as MMP-2 and -9 expressions. Oral administration of CTP increased skin elasticity and decreased abnormal elastic fiber formation. Erythema was also decreased in the CTP-treated group. Taken together, these results strongly suggest that CTP has potential as an anti-photoaging agent.

Effects of Collagen Tripeptide Supplement on Photoaging and Epidermal Skin Barrier in UVB-exposed Hairless Mice

PubMed Central

Pyun, Hee-Bong; Kim, Minji; Park, Jieun; Sakai, Yasuo; Numata, Noriaki; Shin, Jin-Yeong; Shin, Hyun-Jung; Kim, Do-Un; Hwang, Jae-Kwan

2012-01-01

Collagen tripeptide (CTP) is a functional food material with several biological effects such as improving dry skin and wound and bone fracture healing. This study focused on the anti-photoaging effects of CTP on a hairless mouse model. To evaluate the effects of CTP on UVB-induced skin wrinkle formation in vivo, the hairless mice were exposed to UVB radiation with oral administration of CTP for 14 weeks. Compared with the untreated UVB control group, mice treated with CTP showed significantly reduced wrinkle formation, skin thickening, and transepidermal water loss (TEWL). Skin hydration and hydroxyproline were increased in the CTP-treated group. Moreover, oral administration of CTP prevented UVB-induced MMP-3 and -13 activities as well as MMP-2 and -9 expressions. Oral administration of CTP increased skin elasticity and decreased abnormal elastic fiber formation. Erythema was also decreased in the CTP-treated group. Taken together, these results strongly suggest that CTP has potential as an anti-photoaging agent. PMID:24471092

In situ synthesis of silver-nanoparticles/bacterial cellulose composites for slow-released antimicrobial wound dressing.

PubMed

Wu, Jian; Zheng, Yudong; Song, Wenhui; Luan, Jiabin; Wen, Xiaoxiao; Wu, Zhigu; Chen, Xiaohua; Wang, Qi; Guo, Shaolin

2014-02-15

Bacterial cellulose has attracted increasing attention as a novel wound dressing material, but it has no antimicrobial activity, which is one of critical skin-barrier functions in wound healing. To overcome such deficiency, we developed a novel method to synthesize and impregnate silver nanoparticles on to bacterial cellulose nanofibres (AgNP-BC). Uniform spherical silver nano-particles (10-30 nm) were generated and self-assembled on the surface of BC nano-fibers, forming a stable and evenly distributed Ag nanoparticles coated BC nanofiber. Such hybrid nanostructure prevented Ag nanoparticles from dropping off BC network and thus minimized the toxicity of nanoparticles. Regardless the slow Ag(+) release, AgNP-BC still exhibited significant antibacterial activities with more than 99% reductions in Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa. Moreover, AgNP-BC allowed attachment and growth of epidermal cells with no cytotoxicity emerged. The results demonstrated that AgNP-BC could reduce inflammation and promote wound healing. Copyright © 2013 Elsevier Ltd. All rights reserved.

[Wet work].

PubMed

Kieć-Swierczyńska, Marta; Chomiczewska, Dorota; Krecisz, Beata

2010-01-01

Wet work is one of the most important risk factors of occupational skin diseases. Exposure of hands to the wet environment for more than 2 hours daily, wearing moisture-proof protective gloves for a corresponding period of time or necessity to wash hands frequently lead to the disruption of epidermal stratum corneum, damage to skin barrier function and induction of irritant contact dermatitis. It may also promote penetration of allergens into the skin and increase the risk of sensitization to occupational allergens. Exposure to wet work plays a significant role in occupations, such as hairdressers and barbers, nurses and other health care workers, cleaning staff, food handlers and metalworkers. It is more common among women because many occupations involving wet work are female-dominated. The incidence of wet-work-induced occupational skin diseases can be reduced by taking appropriate preventive measures. These include identification of high-risk groups, education of workers, organization of work enabling to minimize the exposure to wet work, use of personal protective equipment and skin care after work.

Time-Restricted Feeding Shifts the Skin Circadian Clock and Alters UVB-Induced DNA Damage.

PubMed

Wang, Hong; van Spyk, Elyse; Liu, Qiang; Geyfman, Mikhail; Salmans, Michael L; Kumar, Vivek; Ihler, Alexander; Li, Ning; Takahashi, Joseph S; Andersen, Bogi

2017-08-01

The epidermis is a highly regenerative barrier protecting organisms from environmental insults, including UV radiation, the main cause of skin cancer and skin aging. Here, we show that time-restricted feeding (RF) shifts the phase and alters the amplitude of the skin circadian clock and affects the expression of approximately 10% of the skin transcriptome. Furthermore, a large number of skin-expressed genes are acutely regulated by food intake. Although the circadian clock is required for daily rhythms in DNA synthesis in epidermal progenitor cells, RF-induced shifts in clock phase do not alter the phase of DNA synthesis. However, RF alters both diurnal sensitivity to UVB-induced DNA damage and expression of the key DNA repair gene, Xpa. Together, our findings indicate regulation of skin function by time of feeding and emphasize a link between circadian rhythm, food intake, and skin health. Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.

Epidermal-skin-test 1,000 (EST-1,000)--a new reconstructed epidermis for in vitro skin corrosivity testing.

PubMed

Hoffmann, J; Heisler, E; Karpinski, S; Losse, J; Thomas, D; Siefken, W; Ahr, H-J; Vohr, H-W; Fuchs, H W

2005-10-01

The determination of a possible corrosive or irritative potential of certain products and ingredients is necessary for their classification and labeling requirements. Reconstructed skin as a model system provides fundamental advantages to single cell culture testing and leads to promising results as shown by different validation studies (for review: Fentem, J.H., Botham, P.A., 2002. ECVAM's activities in validating alternative tests for skin corrosion and irritation. ATLA 30(Suppl. 2), 61-67). In this study we introduce our new reconstructed epidermis "Epidermal-Skin-Test" (EST-1,000). This fully grown epidermis consists of proliferating as well as differentiating keratinocytes. EST-1,000 shows a high comparability to normal human skin as shown by histological and immunohistochemical data. Characteristic markers (KI-67, CK 1/10/5/14, transglutaminase, collagen IV, involucrin, beta 1 integrin) can be identified easily. The main focus of this work was to characterize EST-1,000 especially with respect to its barrier function by testing several substances of known corrosive potential. Skin corrosion was detected by the cytotoxic effect of the substances on a reconstructed epidermis after short-term application to the stratum corneum. The effect was determined by standard MTT assay and accompanying histological analysis. Hence EST-1,000 shows a very high predictive potential and closes the gap between animal testing and the established full-thickness model Advanced-Skin-Test 2,000 (AST-2,000) (Noll, M., Merkle, M.-L., Kandsberger, M., Matthes, T., Fuchs, H., Graeve, T., 1999. Reconstructed human skin (AST-2,000) as a tool for pharmaco-toxicology. ATLA 27, 302).

Skin-on-a-chip model simulating inflammation, edema and drug-based treatment

PubMed Central

Wufuer, Maierdanjiang; Lee, GeonHui; Hur, Woojune; Jeon, Byoungjun; Kim, Byung Jun; Choi, Tae Hyun; Lee, SangHoon

2016-01-01

Recent advances in microfluidic cell cultures enable the construction of in vitro human skin models that can be used for drug toxicity testing, disease study. However, current in vitro skin model have limitations to emulate real human skin due to the simplicity of model. In this paper, we describe the development of ‘skin-on-a-chip’ to mimic the structures and functional responses of the human skin. The proposed model consists of 3 layers, on which epidermal, dermal and endothelial components originated from human, were cultured. The microfluidic device was designed for co-culture of human skin cells and each layer was separated by using porous membranes to allow interlayer communication. Skin inflammation and edema were induced by applying tumor necrosis factor alpha on dermal layer to demonstrate the functionality of the system. The expression levels of proinflammatory cytokines were analyzed to illustrate the feasibility. In addition, we evaluated the efficacy of therapeutic drug testing model using our skin chip. The function of skin barrier was evaluated by staining tight junctions and measuring a permeability of endothelium. Our results suggest that the skin-on-a-chip model can potentially be used for constructing in vitro skin disease models or for testing the toxicity of cosmetics or drugs. PMID:27869150

Reconstitution of full‐thickness skin by microcolumn grafting

PubMed Central

Wang, Ying; Vuong, Linh N.; Fisher, Jeremy M.; Farinelli, William A.; Anderson, R. Rox

2016-01-01

Abstract In addition to providing a physical barrier, skin also serves a diverse range of physiological functions through different specialized resident cell types/structures, including melanocytes (pigmentation and protection against ultraviolet radiation), Langerhans cells (adaptive immunity), fibroblasts (maintaining extracellular matrix, paracrine regulation of keratinocytes), sweat glands (thermoregulation) and hair follicles (hair growth, sensation and a stem cell reservoir). Restoration of these functional elements has been a long‐standing challenge in efforts to engineer skin tissue, while autologous skin grafting is limited by the scarcity of donor site skin and morbidity caused by skin harvesting. We demonstrate an alternative approach of harvesting and then implanting μm‐scale, full‐thickness columns of human skin tissue, which can be removed from a donor site with minimal morbidity and no scarring. Fresh human skin microcolumns were used to reconstitute skin in wounds on immunodeficient mice. The restored skin recapitulated many key features of normal human skin tissue, including epidermal architecture, diverse skin cell populations, adnexal structures and sweat production in response to cholinergic stimulation. These promising preclinical results suggest that harvesting and grafting of microcolumns may be useful for reconstituting fully functional skin in human wounds, without donor site morbidity. © 2016 The Authors Journal of Tissue Engineering and Regenerative Medicine Published by John Wiley & Sons Ltd. PMID:27296503

Protease-Activated Receptor-2 Is Associated with Terminal Differentiation of Epidermis and Eccrine Sweat Glands

PubMed Central

Shin, Yong-Sup; Kim, Hyung Won; Kim, Chang Deok; Kim, Hyun-Woo; Park, Jin Woon; Jung, Sunggyun; Lee, Jeung-Hoon; Ko, Young-Kwon

2015-01-01

Background Protease-activated receptor 2 (PAR-2) participates in various biological activities, including the regulation of epidermal barrier homeostasis, inflammation, pain perception, and melanosome transfer in the skin. Objective To evaluate the basic physiological role of PAR-2 in skin. Methods We investigated PAR-2 expression in human epidermis, skin tumors, and cultured epidermal cells using western blot and immunohistochemical analysis. Additionally, we examined the effect of the PAR-2 agonist, SLIGRL-NH2, on cultured keratinocytes. Results Strong PAR-2 immunoreactivity was observed in the granular layer of normal human skin and the acrosyringium of the eccrine sweat glands. In contrast, weak PAR-2 immunoreactivity was seen in the granular layer of callused skin and in the duct and gland cells of the eccrine sweat glands. Interestingly, PAR-2 immunoreactivity was very weak or absent in the tumor cells of squamous cell carcinoma (SCC) and syringoma. PAR-2 was detected in primary keratinocytes and SV-40T-transformed human epidermal keratinocytes (SV-HEKs), an immortalized keratinocyte cell line, but not in SCC12 cells. SV-HEKs that were fully differentiated following calcium treatment displayed higher PAR-2 expression than undifferentiated SV-HEKs. Treatment of cultured SV-HEKs with PAR-2 agonist increased loricrin and filaggrin expression, a terminal differentiation marker. Conclusion Our data suggest that PAR-2 is associated with terminal differentiation of epidermis and eccrine sweat glands. PMID:26273149

Protease-Activated Receptor-2 Is Associated with Terminal Differentiation of Epidermis and Eccrine Sweat Glands.

PubMed

Shin, Yong-Sup; Kim, Hyung Won; Kim, Chang Deok; Kim, Hyun-Woo; Park, Jin Woon; Jung, Sunggyun; Lee, Jeung-Hoon; Ko, Young-Kwon; Lee, Young Ho

2015-08-01

Protease-activated receptor 2 (PAR-2) participates in various biological activities, including the regulation of epidermal barrier homeostasis, inflammation, pain perception, and melanosome transfer in the skin. To evaluate the basic physiological role of PAR-2 in skin. We investigated PAR-2 expression in human epidermis, skin tumors, and cultured epidermal cells using western blot and immunohistochemical analysis. Additionally, we examined the effect of the PAR-2 agonist, SLIGRL-NH2, on cultured keratinocytes. Strong PAR-2 immunoreactivity was observed in the granular layer of normal human skin and the acrosyringium of the eccrine sweat glands. In contrast, weak PAR-2 immunoreactivity was seen in the granular layer of callused skin and in the duct and gland cells of the eccrine sweat glands. Interestingly, PAR-2 immunoreactivity was very weak or absent in the tumor cells of squamous cell carcinoma (SCC) and syringoma. PAR-2 was detected in primary keratinocytes and SV-40T-transformed human epidermal keratinocytes (SV-HEKs), an immortalized keratinocyte cell line, but not in SCC12 cells. SV-HEKs that were fully differentiated following calcium treatment displayed higher PAR-2 expression than undifferentiated SV-HEKs. Treatment of cultured SV-HEKs with PAR-2 agonist increased loricrin and filaggrin expression, a terminal differentiation marker. Our data suggest that PAR-2 is associated with terminal differentiation of epidermis and eccrine sweat glands.

Angiotensin-converting enzyme inhibitor (enalapril maleate) accelerates recovery of mouse skin from UVB-induced wrinkles

DOE Office of Scientific and Technical Information (OSTI.GOV)

Matsuura-Hachiya, Yuko; Arai, Koji Y.; Ozeki, Rieko

Highlights: •Angiotensin converting enzyme (ACE) increases in UVB-irradiated skin. •Administration of an ACE inhibitor improved UVB-induced skin wrinkle. •ACE inhibitor improved UVB-induced epidermal hypertrophy. •ACE inhibitor improved transepidermal water loss in the UVB-irradiated skin. -- Abstract: Angiotensin-converting enzyme (ACE) activity and angiotensin II signaling regulate cell proliferation, differentiation, and tissue remodeling, as well as blood pressure, while in skin, angiotensin II signaling is involved in wound healing, inflammation, and pathological scar formation. Therefore, we hypothesized that angiotensin II is also involved in photoaging of skin. In this study, we examined the effect of enalapril maleate, an ACE inhibitor, on recoverymore » of wrinkled skin of hairless mice exposed to long-term UVB irradiation. Immunohistochemical observation revealed that expression of ACE, angiotensin II, and angiotensin II type 1 (AT1) and type 2 (AT2) receptors in the skin was increased after UVB irradiation (3 times/week at increasing intensities for 8 weeks). Administration of enalapril maleate (5 times/week for 6 weeks, starting 1 week after 10-week irradiation) accelerated recovery from UVB-induced wrinkles, epidermal hyperplasia and epidermal barrier dysfunction, as compared with the vehicle control. Our results indicate that ACE and angiotensin II activity are involved in skin photoaging, and suggest that ACE inhibitor such as enalapril maleate may have potential for improvement of photoaged skin.« less

Duox, Flotillin-2, and Src42A Are Required to Activate or Delimit the Spread of the Transcriptional Response to Epidermal Wounds in Drosophila

PubMed Central

Juarez, Michelle T.; Patterson, Rachel A.; Sandoval-Guillen, Efren; McGinnis, William

2011-01-01

The epidermis is the largest organ of the body for most animals, and the first line of defense against invading pathogens. A breach in the epidermal cell layer triggers a variety of localized responses that in favorable circumstances result in the repair of the wound. Many cellular and genetic responses must be limited to epidermal cells that are close to wounds, but how this is regulated is still poorly understood. The order and hierarchy of epidermal wound signaling factors are also still obscure. The Drosophila embryonic epidermis provides an excellent system to study genes that regulate wound healing processes. We have developed a variety of fluorescent reporters that provide a visible readout of wound-dependent transcriptional activation near epidermal wound sites. A large screen for mutants that alter the activity of these wound reporters has identified seven new genes required to activate or delimit wound-induced transcriptional responses to a narrow zone of cells surrounding wound sites. Among the genes required to delimit the spread of wound responses are Drosophila Flotillin-2 and Src42A, both of which are transcriptionally activated around wound sites. Flotillin-2 and constitutively active Src42A are also sufficient, when overexpressed at high levels, to inhibit wound-induced transcription in epidermal cells. One gene required to activate epidermal wound reporters encodes Dual oxidase, an enzyme that produces hydrogen peroxide. We also find that four biochemical treatments (a serine protease, a Src kinase inhibitor, methyl-ß-cyclodextrin, and hydrogen peroxide) are sufficient to globally activate epidermal wound response genes in Drosophila embryos. We explore the epistatic relationships among the factors that induce or delimit the spread of epidermal wound signals. Our results define new genetic functions that interact to instruct only a limited number of cells around puncture wounds to mount a transcriptional response, mediating local repair and regeneration. PMID:22242003

Cellular interactions of a lipid-based nanocarrier model with human keratinocytes: Unravelling transport mechanisms.

PubMed

Silva, Elisabete; Barreiros, Luísa; Segundo, Marcela A; Costa Lima, Sofia A; Reis, Salette

2017-04-15

Knowledge of delivery system transport through epidermal cell monolayer is vital to improve skin permeation and bioavailability. Recently, nanostructured lipid carriers (NLCs) have gained great attention for transdermal delivery due to their biocompatibility, high drug payload, occlusive properties and skin hydration effect. However, the nanocarriers transport related mechanisms in epidermal epithelial cells are not yet understood. In this research, the internalization and transport pathways of the NLCs across the epidermal epithelial cell monolayer (HaCaT cells) were investigated. The 250nm sized witepsol/miglyol NLCs, prepared by hot homogenization had reduced cytotoxicity and no effect on the integrity of cell membrane in human HaCaT keratinocytes. The internalization was time-, concentration- and energy-dependent, and the uptake of NLCs was a vesicle-mediated process by macropinocytosis and clathrin-mediated pathways. 3% of NLCs were found at the apical membrane side of the HaCaT monolayer through exocytosis mechanism. Additionally, the endoplasmic reticulum, Golgi apparatus and microtubules played crucial roles in the transport of NLCs out of HaCaT cells. NLCs were transported intact across the human keratinocytes monolayer, without disturbing the tight junction's structure. From the transcytosis data only approximately 12% of the internalized NLCs were passed from the apical to the basolateral side. The transcytosis of NLCs throughout the HaCaT cell monolayer towards the basolateral membrane side requires the involvement of the endoplasmic reticulum, Golgi apparatus and microtubules. Our findings may contribute to a systematic understanding of NLCs transport across epidermal epithelial cell monolayers and their optimization for clinical transdermal application. Transdermal drug delivery is a challenging and growing area of clinical application. Lipid nanoparticles such as nanostructured lipid carriers (NLCs) have gained wide interest for transdermal drug delivery. However these nanocarriers' interactions with epidermal epithelial barrier are yet unknown. Unveiling the mechanisms involved in NLCs transport across the epidermal epithelial monolayers will contribute with valuable information to achieve enhanced skin permeability, superior bioavailability and consequently improved therapeutic effect. With our present work we could certainly provide researchers and clinicians guidance for the design of optimized transdermal delivery systems, based on the nanomaterials and biological interactions. Copyright © 2017 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Sodium lauryl sulphate alters the mRNA expression of lipid-metabolizing enzymes and PPAR signalling in normal human skin in vivo.

PubMed

Törmä, Hans; Berne, Berit

2009-12-01

Detergents irritate skin and affect skin barrier homeostasis. In this study, healthy skin was exposed to 1% sodium lauryl sulphate (SLS) in water for 24 h. Biopsies were taken 6 h to 8 days post exposure. Lipid patterns were stained in situ and real-time polymerase chain reaction (PCR) was used to examine mRNA expression of enzymes synthesizing barrier lipids, peroxisome proliferator-activated receptors (PPAR) and lipoxygenases. The lipid pattern was disorganized from 6 h to 3 days after SLS exposure. Concomitant changes in mRNA expression included: (i) reduction, followed by induction, of ceramide-generating beta-glucocerebrosidase, (ii) increase on day 1 of two other enzymes for ceramide biosynthesis and (iii) persistent reduction of acetyl-CoA carboxylase-B, a key enzyme in fatty acid synthesis. Surprisingly, the rate-limiting enzyme in cholesterol synthesis, HMG-CoA reductase, was unaltered. Among putative regulators of barrier lipids synthesis, PPARalpha and PPARgamma exhibited reduced mRNA expression, while PPARbeta/delta and LXRbeta were unaltered. Epidermal lipoxygenase-3, which may generate PPARalpha agonists, exhibited reduced expression. In conclusion, SLS induces reorganization of lipids in the stratum corneum, which play a role in detergents' destruction of the barrier. The changes in mRNA expression of enzymes involved in synthesizing barrier lipids are probably important for the restoration of the barrier.

H{sup +}/peptide transporter (PEPT2) is expressed in human epidermal keratinocytes and is involved in skin oligopeptide transport

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kudo, Michiko; Katayoshi, Takeshi; Kobayashi-Nakamura, Kumiko

Peptide transporter 2 (PEPT2) is a member of the proton-coupled oligopeptide transporter family, which mediates the cellular uptake of oligopeptides and peptide-like drugs. Although PEPT2 is expressed in many tissues, its expression in epidermal keratinocytes remains unclear. We investigated PEPT2 expression profile and functional activity in keratinocytes. We confirmed PEPT2 mRNA expression in three keratinocyte lines (normal human epidermal keratinocytes (NHEKs), immortalized keratinocytes, and malignant keratinocytes) by reverse transcription-polymerase chain reaction (RT-PCR) and quantitative real-time RT-PCR. In contrast to PEPT1, PEPT2 expression in the three keratinocytes was similar or higher than that in HepG2 cells, used as PEPT2-positive cells. Immunolocalizationmore » analysis using human skin showed epidermal PEPT2 localization. We studied keratinocyte transport function by measuring the oligopeptide content using liquid chromatography/tandem mass spectrometry. Glycylsarcosine uptake in NHEKs was pH-dependent, suggesting that keratinocytes could absorb small peptides in the presence of an inward H{sup +} gradient. We also performed a skin-permeability test of several oligopeptides using skin substitute, suggesting that di- and tripeptides pass actively through the epidermis. In conclusion, PEPT2 is expressed in keratinocytes and involved in skin oligopeptide uptake. -- Highlights: •PEPT2 is expressed in keratinocytes, which are more common than other skin cells. •Immunolocalization analysis using human skin revealed epidermal PEPT2 localization. •Keratinocytes could absorb small peptides in the presence of an inward H{sup +} gradient. •Di- and tripeptide pass actively through the epidermis.« less

Shining light on skin pigmentation: the darker and the brighter side of effects of UV radiation.

PubMed

Maddodi, Nityanand; Jayanthy, Ashika; Setaluri, Vijayasaradhi

2012-01-01

The term barrier function as applied to human skin often connotes the physical properties of this organ that provides protection from its surrounding environment. This term does not generally include skin pigmentation. However, skin pigmentation, which is the result of melanin produced in melanocytes residing in the basal layer of the skin and exported to the keratinocytes in the upper layers, serves equally important protective function. Indeed, changes in skin pigmentation are often the most readily recognized indicators of exposure of skin to damaging agents, especially to natural and artificial radiation in the environment. Several recent studies have shed new light on (1) the mechanisms involved in selective effects of subcomponents of UV radiation on human skin pigmentation and (2) the interactive influences between keratinocytes and melanocytes, acting as "epidermal melanin unit," that manifest as changes in skin pigmentation in response to exposure to various forms of radiation. This article provides a concise review of our current understanding of the effects of the nonionizing solar radiation, at cellular and molecular levels, on human skin pigmentation. © 2012 Wiley Periodicals, Inc. Photochemistry and Photobiology © 2012 The American Society of Photobiology.

Seeking better topical delivery technologies of moisturizing agents for enhanced skin moisturization.

PubMed

Kim, Hyeongmin; Kim, Jeong Tae; Barua, Sonia; Yoo, Seung-Yup; Hong, Seong-Chul; Lee, Kyung Bin; Lee, Jaehwi

2018-01-01

An adequate hydration level is essential to maintain epidermal barrier functions and normal physiological activities of skin tissues. Diverse moisturizing agents and pharmaceutical formulations for dermal deliveries have thus extensively been investigated. This review comprehensively discusses scientific outcomes of moisturizing agents and pharmaceutical vehicles for skin moisturization, thereby providing insight into designing innovative pharmaceutical formulations for effective skin moisturization. Areas covered: We discussed the functions of various moisturizing agents ranging from conventional creams to novel moisturizers which has recently been explored. In addition, novel pharmaceutical formulations for efficient dermal delivery of the moisturizers, in particular, nanocarriers, were discussed along with their uses in commercial products. Expert opinion: Although various moisturizing agents have demonstrated their promising effects, exploitation of pharmaceutical formulations for their dermal delivery have been limited to few commonly used moisturizing agents. Thus, combinatorial investigation of novel moisturizers and pharmaceutical vehicles should be further conducted. As a new concept for improving skin moisturization, skin regeneration technologies using therapeutic cells have recently shown great promise for skin moisturization, but major challenges remain, such as efficient delivery and prolonged survival of such cells. Thus, novel approaches for improving skin moisturization require continuous efforts of pharmaceutical scientists to address the remaining problems.

Integrin Beta 1 Suppresses Multilayering of a Simple Epithelium

PubMed Central

Chen, Jichao; Krasnow, Mark A.

2012-01-01

Epithelia are classified as either simple, a single cell layer thick, or stratified (multilayered). Stratified epithelia arise from simple epithelia during development, and transcription factor p63 functions as a key positive regulator of epidermal stratification. Here we show that deletion of integrin beta 1 (Itgb1) in the developing mouse airway epithelium abrogates airway branching and converts this monolayer epithelium into a multilayer epithelium with more than 10 extra layers. Mutant lung epithelial cells change mitotic spindle orientation to seed outer layers, and cells in different layers become molecularly and functionally distinct, hallmarks of normal stratification. However, mutant lung epithelial cells do not activate p63 and do not switch to the stratified keratin profile of epidermal cells. These data, together with previous data implicating Itgb1 in regulation of epidermal stratification, suggest that the simple-versus-stratified developmental decision may involve not only stratification inducers like p63 but suppressors like Itgb1 that prevent simple epithelia from inappropriately activating key steps in the stratification program. PMID:23285215

Endophilin-1 regulates blood-brain barrier permeability via EGFR-JNK signaling pathway.

PubMed

Chen, Lin; Liu, Wenjing; Wang, Ping; Xue, Yixue; Su, Qingjie; Zeng, Chaosheng; Shang, Xiuli

2015-05-05

Endophilin-1 (Endo1), a multifunctional protein, is essential for synaptic vesicle endocytosis. However, the role and mechanism of endophilin-1 in blood-brain barrier (BBB) function are still unclear. This study was performed to determine whether endophilin-1 regulated BBB permeability via the EGFR-JNK signaling pathway. In the present study, we found that endophilin-1 over-expression in human cerebral microvascular endothelial cell (hCMEC/D3) increased BBB permeability and meanwhile reduced the expression levels of epidermal growth factor receptor (EGFR), phosphorylated c-Jun N-terminal kinase (p-JNK). While endophilin-1 knockdown led to the contrary results. After JNK inhibitor SP600125 was administered to the endophilin-1 silenced hCMEC/D3 cells, the transendothelial electrical resistance (TEER) value was decreased and the permeability coefficient values to 4kDa and 40kDa FITC-dextran were increased. Results observed by Transmission electron microscopy (TEM) showed that tight junctions (TJs) were opened. Moreover, immunofluorescence and Western blot assays revealed the discontinuous distribution of TJ-associated proteins ZO-1, occludin on cell-cell boundaries and a significant decrease in protein expressing levels. Therefore, these results indicated that endophilin-1 positively regulated BBB permeability via the EGFR-JNK signaling pathway in hCMEC/D3 cells, which would provide an experimental basis for further research on endophilin-1 mediated the opening of BBB. Copyright © 2015 Elsevier B.V. All rights reserved.

Molecular dynamics simulations of transitions for ECD epidermal growth factor receptors show key differences between human and drosophila forms of the receptors.

PubMed

Perilla, Juan R; Leahy, Daniel J; Woolf, Thomas B

2013-07-01

Recent X-ray structural work on the Drosophila epidermal growth factor receptor (EFGR) has suggested an asymmetric dimer that rationalizes binding affinity measurements that go back decades (Alvarado et al., Cell 2010;142:568-579; Dawson et al., Structure 2007;15:942-954; Lemmon et al., Embo J 1997;16:281-294; Mattoon et al., Proc Natl Acad Sci USA 2004;101:923-928; Mayawala et al., Febs Lett 2005;579:3043-3047; Ozcan et al., Proc Natl Acad Sci USA 2006;103:5735-5740). This type of asymmetric structure has not been seen for the human EGF receptor family and it may or may not be important for function in that realm. We hypothesize that conformational changes in the Drosophila system have been optimized for the transition, whereas the barrier for the same transition is much higher in the human forms. To address our hypothesis we perform dynamic importance sampling (DIMS) (Perilla et al., J Comput Chem 2010;32:196-209) for barrier crossing transitions in both Drosophila and human EFGRs. For each set of transitions, we work from the hypothesis, based on results from the AdK system, that salt-bridge pairs making and breaking connections are central to the conformational change. To evaluate the effectiveness of the salt-bridges as drivers for the conformational change, we use the effective transfer entropy based on stable state MD calculations (Kamberaj and Der Vaart, Biophys J 2009;97:1747-1755) to define a reduced subset of degrees of freedom that seem to be important for driving the transition (Perilla and Woolf, J Chem Phys 2012;136:164101). Our results suggest that salt-bridge making and breaking is not the dominant factor in driving the symmetric to asymmetric transition, but that instead it is a result of more concerted and correlated functional motions within a subset of the dimer structures. Furthermore, the analysis suggests that the set of residues involved in the transitions from the Drosophila relative to the human forms differs and that this difference in substate distributions relates to why the asymmetric form may be more common to Drosophila than to the human forms. We close with a discussion about the residues that may be changed in the human and the Drosophila forms to potentially shift the kinetics of the symmetric to asymmetric transition. Copyright © 2013 Wiley Periodicals, Inc.

Immunohistochemical expression of AQP-3 in vitiligo: a new potential guide for disease activity.

PubMed

Hodeib, Abeer; Hegab, Doaa; Rizk, Omnia; Mohammed, Shahdan

2017-08-01

Vitiligo is a depigmenting skin disorder, with disappearance of functioning epidermal melanocytes. Aquaporin-3 (AQP-3) is an aquaglyceroporin expressed in epidermal keratinocytes, where it shares in regulating their proliferation and differentiation, and so it might affect melanocytes indirectly. So far, little is known regarding its possible role in vitiligo. This work aimed to study the changes in immunohistochemical expression of AQP-3 protein in vitiligo to detect its possible role in disease pathogenesis. Skin biopsies were taken from lesional skin of 30 vitiligo patients in addition to 20 normal controls. Epidermal immunohistochemical expression of AQP-3 was assessed as: +3 = strong expression, +2 = moderate, +1= weak and 0= negative expression. AQP-3 was significantly less expressed in vitiligo epidermis than control (P<0.001) with an inverse correlation with Vitiligo Index of Disease Activity (r =-0.505, P=0.004). Reduced epidermal AQP-3 may have a role in impaired melanocyte survival in vitiligo, and might be a potential negative biological marker for vitiligo activity. Larger trials should further elucidate the effect of changes in epidermal AQP-3 expression in development of vitiligo, and that might pave the road for discovering new therapeutic modalities for the disease.

Epidermal growth factor- and hepatocyte growth factor-receptor activity in serum-free cultures of human hepatocytes.

PubMed

Runge, D M; Runge, D; Dorko, K; Pisarov, L A; Leckel, K; Kostrubsky, V E; Thomas, D; Strom, S C; Michalopoulos, G K

1999-02-01

Serum-free primary cultures of hepatocytes are a useful tool to study factors triggering hepatocyte proliferation and regeneration. We have developed a chemically defined serum-free system that allows human hepatocyte proliferation in the presence of epidermal growth factor and hepatocyte growth factor. DNA synthesis and accumulation were determined by [3H]thymidine incorporation and fluorometry, respectively. Western blot analyses and co-immunoprecipitations were used to investigate the association of proteins involved in epidermal growth factor and hepatocyte growth factor activation and signaling: epidermal growth factor receptor, hepatocyte growth factor receptor (MET), urokinase-type plasminogen activator and its receptor, and a member of the signal transducer and activator of transcription family, STAT-3. Primary human hepatocytes proliferated under serum-free conditions in a chemically defined medium for up to 12 days. Epidermal growth factor-receptor and MET were present and functional, decreasing over time. MET, urokinase-type plasminogen activator and urokinase-type plasminogen activator receptor co-precipitated to varying degrees during the culture period. STAT-3 co-precipitated with epidermal growth factor-receptor and MET to varying degrees. Proliferation of human hepatocytes can improve by modification of a chemically defined medium originally used for rat hepatocyte cultures. In these long-term cultures of human hepatocytes, hepatocyte growth factor and epidermal growth factor can stimulate growth and differentiation by interacting with their receptors and initiating downstream signaling. This involves complex formation of the receptors with other plasma membrane components for MET (urokinase-type plasminogen activator in context of its receptor) and activation of STAT-3 for both receptors.

Human epidermal langerhans cells express the immunoregulatory enzyme indoleamine 2,3-dioxygenase.

PubMed

von Bubnoff, Dagmar; Bausinger, Huguette; Matz, Heike; Koch, Susanne; Häcker, Georg; Takikawa, Osamu; Bieber, Thomas; Hanau, Daniel; de la Salle, Henri

2004-08-01

Langerhans cells (LC) are a special subset of dendritic cells integrating cutaneous immunity. The study of LC function is of major interest not only for efforts of vaccine design and immunotherapy but also for gaining an insight into the pathogenesis of immune-mediated cutaneous diseases and neoplasias. Recently, defined antigen-presenting cells were described that express indoleamine 2,3-dioxygenase (IDO) and inhibit T cell proliferation in vitro and in vivo. Here, we show that stimulation with interferon-gamma (IFN-gamma) induces the expression of functionally active IDO in highly purified human epidermal LC. The induction of IDO after stimulation of LC with IFN-gamma seems to follow a defined kinetic with rapid upregulation followed by a downregulation after about 24 h of culture. Accordingly, proliferation of T cells induced by anti-CD3 antibodies was modulated by supernatants of IFN-gamma-activated human epidermal LC. Importantly, downregulation of T cell proliferation by supernatants of 24 h IFN-gamma-activated LC was prevented by inhibition of IDO. These results indicate that LC not only have the capacity to stimulate but also to inhibit T cells, and suggest that LC possess an immunoregulatory function in promoting T cell tolerance by production of IDO.

Drug Delivery Through the Skin: Molecular Simulations of Barrier Lipids to Design more Effective Noninvasive Dermal and Transdermal Delivery Systems for Small Molecules Biologics and Cosmetics

DOE Office of Scientific and Technical Information (OSTI.GOV)

J Torin Huzil; S Sivaloganathan; M Kohandel

The delivery of drugs through the skin provides a convenient route of administration that is often preferable to injection because it is noninvasive and can typically be self-administered. These two factors alone result in a significant reduction of medical complications and improvement in patient compliance. Unfortunately, a significant obstacle to dermal and transdermal drug delivery alike is the resilient barrier that the epidermal layers of the skin, primarily the stratum corneum, presents for the diffusion of exogenous chemical agents. Further advancement of transdermal drug delivery requires the development of novel delivery systems that are suitable for modern, macromolecular protein andmore » nucleotide therapeutic agents. Significant effort has already been devoted to obtain a functional understanding of the physical barrier properties imparted by the epidermis, specifically the membrane structures of the stratum corneum. However, structural observations of membrane systems are often hindered by low resolutions, making it difficult to resolve the molecular mechanisms related to interactions between lipids found within the stratum corneum. Several models describing the molecular diffusion of drug molecules through the stratum corneum have now been postulated, where chemical permeation enhancers are thought to disrupt the underlying lipid structure, resulting in enhanced permeability. Recent investigations using biphasic vesicles also suggested a possibility for novel mechanisms involving the formation of complex polymorphic lipid phases. In this review, we discuss the advantages and limitations of permeation-enhancing strategies and how computational simulations, at the atomic scale, coupled with physical observations can provide insight into the mechanisms of diffusion through the stratum corneum.« less

DFD-01 Reduces Transepidermal Water Loss and Improves Skin Hydration and Flexibility.

PubMed

Jackson, J Mark; Grove, Gary L; Allenby, Kent; Houser, Tim

2017-12-01

In plaque psoriasis, the benefit of topical steroids is well established. The vehicle formulation of topical steroids may also provide benefit in addition to the effects of the steroid itself. DFD-01 (betamethasone dipropionate spray, 0.05%) is a formulation composed of a topical steroid in an emollient-like vehicle that enhances penetration to the target site of inflammation in the skin. The aim of this study was to assess the effect of DFD-01 and its vehicle on skin hydration and barrier function in compromised skin and to evaluate its effect on flexibility in healthy skin. Eighteen healthy white volunteers were enrolled in each of two studies. In Study 1, dry shaving of volar forearms created a compromised skin barrier, through which transepidermal water loss (TEWL) was measured using an evaporimeter. Capacitance, a measure of epidermal hydration, was also measured at baseline and at 1, 2 and 4 h after application of DFD-01 or its vehicle formulation. In Study 2, intact skin flexibility was tested with a cutometer before and at 1, 2 and 4 h after application of DFD-01 or vehicle. In Study 1, both DFD-01 and its vehicle were effective at reducing TEWL through the compromised stratum corneum. Capacitance measurements confirmed this finding; razor-chafed skin treated with either DFD-01 or vehicle exhibited levels of skin hydration similar to unshaved control skin. Study 2 found softening and greater flexibility of normal skin treated with either DFD-01 or vehicle compared with nontreated control skin samples. These tests suggest that the DFD-01 formulation and its vehicle are each effective at retaining moisture within a damaged skin barrier and for softening and increasing the flexibility of intact skin. Dr. Reddy's Laboratories.

Hair Follicle and Sebaceous Gland De Novo Regeneration With Cultured Epidermal Stem Cells and Skin-Derived Precursors.

PubMed

Wang, Xiaoxiao; Wang, Xusheng; Liu, Jianjun; Cai, Ting; Guo, Ling; Wang, Shujuan; Wang, Jinmei; Cao, Yanpei; Ge, Jianfeng; Jiang, Yuyang; Tredget, Edward E; Cao, Mengjun; Wu, Yaojiong

2016-12-01

: Stem cell-based organ regeneration is purported to enable the replacement of impaired organs in the foreseeable future. Here, we demonstrated that a combination of cultured epidermal stem cells (Epi-SCs) derived from the epidermis and skin-derived precursors (SKPs) was capable of reconstituting functional hair follicles and sebaceous glands (SG). When Epi-SCs and SKPs were mixed in a hydrogel and implanted into an excisional wound in nude mice, the Epi-SCs formed de novo epidermis along with hair follicles, and SKPs contributed to dermal papilla in the neogenic hair follicles. Notably, a combination of culture-expanded Epi-SCs and SKPs derived from the adult human scalp were sufficient to generate hair follicles and hair. Bone morphogenetic protein 4, but not Wnts, sustained the expression of alkaline phosphatase in SKPs in vitro and the hair follicle-inductive property in vivo when SKPs were engrafted with neonatal epidermal cells into excisional wounds. In addition, Epi-SCs were capable of differentiating into sebocytes and formed de novo SGs, which excreted lipids as do normal SGs. Thus our results indicate that cultured Epi-SCs and SKPs are sufficient to generate de novo hair follicles and SGs, implying great potential to develop novel bioengineered skin substitutes with appendage genesis capacity. In postpartum humans, skin appendages lost in injury are not regenerated, despite the considerable achievement made in skin bioengineering. In this study, transplantation of a combination of culture-expanded epidermal stem cells and skin-derived progenitors from mice and adult humans led to de novo regeneration of functional hair follicles and sebaceous glands. The data provide transferable knowledge for the development of novel bioengineered skin substitutes with epidermal appendage regeneration capacity. ©AlphaMed Press.

Hair Follicle and Sebaceous Gland De Novo Regeneration With Cultured Epidermal Stem Cells and Skin-Derived Precursors

PubMed Central

Wang, Xiaoxiao; Wang, Xusheng; Liu, Jianjun; Cai, Ting; Guo, Ling; Wang, Shujuan; Wang, Jinmei; Cao, Yanpei; Ge, Jianfeng; Jiang, Yuyang; Tredget, Edward E.; Cao, Mengjun

2016-01-01

Stem cell-based organ regeneration is purported to enable the replacement of impaired organs in the foreseeable future. Here, we demonstrated that a combination of cultured epidermal stem cells (Epi-SCs) derived from the epidermis and skin-derived precursors (SKPs) was capable of reconstituting functional hair follicles and sebaceous glands (SG). When Epi-SCs and SKPs were mixed in a hydrogel and implanted into an excisional wound in nude mice, the Epi-SCs formed de novo epidermis along with hair follicles, and SKPs contributed to dermal papilla in the neogenic hair follicles. Notably, a combination of culture-expanded Epi-SCs and SKPs derived from the adult human scalp were sufficient to generate hair follicles and hair. Bone morphogenetic protein 4, but not Wnts, sustained the expression of alkaline phosphatase in SKPs in vitro and the hair follicle-inductive property in vivo when SKPs were engrafted with neonatal epidermal cells into excisional wounds. In addition, Epi-SCs were capable of differentiating into sebocytes and formed de novo SGs, which excreted lipids as do normal SGs. Thus our results indicate that cultured Epi-SCs and SKPs are sufficient to generate de novo hair follicles and SGs, implying great potential to develop novel bioengineered skin substitutes with appendage genesis capacity. Significance In postpartum humans, skin appendages lost in injury are not regenerated, despite the considerable achievement made in skin bioengineering. In this study, transplantation of a combination of culture-expanded epidermal stem cells and skin-derived progenitors from mice and adult humans led to de novo regeneration of functional hair follicles and sebaceous glands. The data provide transferable knowledge for the development of novel bioengineered skin substitutes with epidermal appendage regeneration capacity. PMID:27458264

The Genomic Actions and Functional Implications of Nuclear PRLr in Human Breast Carcinoma

DTIC Science & Technology

2011-03-01

Johnston CL, Cox HC, Gomm JJ, Coombes RC 1995 Fibroblast growth factor receptors ( FGFRs ) localize in different cellular compartments. A splice variant...has been observed (11). The Jak2/Stat5a pathway is widely shared with other transmembrane receptors such as epidermal growth factor receptor (EGFR...2005 Novel prognostic value of nuclear epidermal growth factor receptor in breast cancer. Cancer Res 65:338-348 13. Lin SY, Makino K, Xia W, Matin A

Mismatch between cuticle deposition and area expansion in fruit skins allows potentially catastrophic buildup of elastic strain.

PubMed

Lai, Xiaoting; Khanal, Bishnu Prasad; Knoche, Moritz

2016-11-01

The continuous deposition of cutin and wax during leaf and fruit growth is crucial to alleviate elastic strain of the cuticle, minimize the risk of failure and maintain its barrier functions. The cuticular membrane (CM) is a lipoidal biopolymer that covers primary surfaces of terrestrial plants. CMs have barrier functions in water and solute transfer and pathogen invasion. These require intact CMs throughout growth. This is a challenge particularly for fruit, because they increase in area from initiation through to maturity. Our paper investigates the effects of cutin and wax deposition on strain buildup in the CM. We use developing fruits and leaves of apple (Malus × domestica) and sweet cherry (Prunus avium) as models. The hypothesis was that the continuous deposition of the CM prevents the buildup of excessive elastic strain in fruit and leaves. Strains were quantified from decreases in surface area of CMs after isolation from epidermal discs, after wax extraction and from increases in surface area during development. Cuticle mass per unit area increased throughout development in apple fruit, and leaves of apple and sweet cherry. In sweet cherry fruit, however, CM mass increased only initially, but thereafter decreased as the surface expanded rapidly. The release of strain on CM isolation was low in apple fruit and leaves and sweet cherry leaves, but high in sweet cherry fruit. Conversely, strains fixed by the deposition of wax and cutin were high in apple fruit and leaves and sweet cherry leaves, but low in sweet cherry fruit. Our results indicate that in expanding organs, deposition of cutin and wax in the CM allows conversion of elastic to plastic strain. Hence, any lack of such deposition allows buildup of high, potentially catastrophic, elastic strain.

The DP-1 transcription factor is required for keratinocyte growth and epidermal stratification.

PubMed

Chang, Wing Y; Bryce, Dawn M; D'Souza, Sudhir J A; Dagnino, Lina

2004-12-03

The epidermis is a stratified epithelium constantly replenished through the ability of keratinocytes in its basal layer to proliferate and self-renew. The epidermis arises from a single-cell layer ectoderm during embryogenesis. Large proliferative capacity is central to ectodermal cell and basal keratinocyte function. DP-1, a heterodimeric partner of E2F transcription factors, is highly expressed in the ectoderm and all epidermal layers during embryogenesis. To investigate the role of DP-1 in epidermal morphogenesis, we inhibited DP-1 activity through exogenous expression of a dominant-negative mutant (dnDP-1). Expression of the dnDP-1 mutant interferes with binding of E2F/DP-1 heterodimers to DNA and inhibits DNA replication, as well as cyclin A mRNA and protein expression. Chromatin immunoprecipitation analysis demonstrated that the cyclin A promoter is predominantly bound in proliferating keratinocytes by complexes containing E2F-3 and E2F-4. Thus, the mechanisms of decreased expression of cyclin A in the presence of dnDP-1 seem to involve inactivation of DP-1 complexes containing E2F-3 and E2F-4. To assess the consequences on epidermal morphogenesis of inhibiting DP-1 activity, we expressed dnDP-1 in rat epithelial keratinocytes in organotypic culture and observed that DP-1 inhibition negatively affected stratification of these cells. Likewise, expression of dnDP-1 in embryonic ectoderm explants produced extensive disorganization of subsequently formed epidermal basal and suprabasal layers, interfering with normal epidermal formation. We conclude that DP-1 activity is required for normal epidermal morphogenesis and ectoderm-to-epidermis transition.

Blunted epidermal L-tryptophan metabolism in vitiligo affects immune response and ROS scavenging by Fenton chemistry, part 1: Epidermal H2O2/ONOO(-)-mediated stress abrogates tryptophan hydroxylase and dopa decarboxylase activities, leading to low serotonin and melatonin levels.

PubMed

Schallreuter, Karin U; Salem, Mohamed A E L; Gibbons, Nick C J; Martinez, Aurora; Slominski, Radomir; Lüdemann, Jürgen; Rokos, Hartmut

2012-06-01

Vitiligo is characterized by a progressive loss of inherited skin color. The cause of the disease is still unknown. To date, there is accumulating in vivo and in vitro evidence for massive oxidative stress via hydrogen peroxide (H(2)O(2)) and peroxynitrite (ONOO(-)) in the skin of affected individuals. Autoimmune etiology is the favored theory. Since depletion of the essential amino acid L-tryptophan (Trp) affects immune response mechanisms, we here looked at epidermal Trp metabolism via tryptophan hydroxylase (TPH) with its downstream cascade, including serotonin and melatonin. Our in situ immunofluorescence and Western blot data reveal significantly lower TPH1 expression in patients with vitiligo. Expression is also low in melanocytes and keratinocytes under in vitro conditions. Although in vivo Fourier transform-Raman spectroscopy proves the presence of 5-hydroxytryptophan, epidermal TPH activity is completely absent. Regulation of TPH via microphthalmia-associated transcription factor and L-type calcium channels is severely affected. Moreover, dopa decarboxylase (DDC) expression is significantly lower, in association with decreased serotonin and melatonin levels. Computer simulation supports H(2)O(2)/ONOO(-)-mediated oxidation/nitration of TPH1 and DDC, affecting, in turn, enzyme functionality. Taken together, our data point to depletion of epidermal Trp by Fenton chemistry and exclude melatonin as a relevant contributor to epidermal redox balance and immune response in vitiligo.

The flavonoid hesperidin exerts anti-photoaging effect by downregulating matrix metalloproteinase (MMP)-9 expression via mitogen activated protein kinase (MAPK)-dependent signaling pathways.

PubMed

Lee, Hee Jeong; Im, A-Rang; Kim, Su-Man; Kang, Hyung-Sik; Lee, Jae Dong; Chae, Sungwook

2018-01-30

Hesperidin is a flavonoid with antioxidant, anti-inflammatory, and immune modulatory activities. Photoaging is a consequence of chronic exposure to the sun and ultraviolet (UV) radiation. This study was designed to evaluate the efficacy of hesperidin against photoaging of dorsal skin in hairless mice. Hairless male mice (6-week-old) were divided into three groups (n = 7): control, UVB-treated vehicle, and UVB-treated hesperidin groups. UVB-irradiated mice from hesperidin group were orally administered 0.1 mL of water containing 100 mg/kg body weight per day hesperidin. The mean length and depth of wrinkles in the UVB-treated hesperidin group significantly improved after the oral administration of hesperidin, which significantly inhibited the increase in epidermal thickness and epidermal hypertrophy (P < 0.05). UVB irradiation of mice induced epidermal barrier dysfunction including an increase in the transepidermal water loss (TEWL); however, hesperidin decreased the TEWL. UVB irradiation increased the expression of MMP-9 and pro-inflammatory cytokines whereas UVB-treated hesperidin group showed reduced expression. These results indicate that hesperidin showed anti-photoaging activity in the UVB-irradiated hairless mice. In conclusion, hesperidin inhibited the UVB-induced increase in skin thickness, wrinkle formation, and collagen fiber loss in male hairless mice. These results suggest that hesperidin shows potent anti-photoaging activity by regulating MMP-9 expression through the suppression of MAPK-dependent signaling pathways.

Occludin Is Involved in Adhesion, Apoptosis, Differentiation and Ca2+-Homeostasis of Human Keratinocytes: Implications for Tumorigenesis

PubMed Central

Ohnemus, Ulrich; Kirschner, Nina; Vidal-y-Sy, Sabine; von den Driesch, Peter; Börnchen, Christian; Eberle, Jürgen; Mildner, Michael; Vettorazzi, Eik; Rosenthal, Rita; Moll, Ingrid; Brandner, Johanna M.

2013-01-01

Tight junction (TJ) proteins are involved in a number of cellular functions, including paracellular barrier formation, cell polarization, differentiation, and proliferation. Altered expression of TJ proteins was reported in various epithelial tumors. Here, we used tissue samples of human cutaneous squamous cell carcinoma (SCC), its precursor tumors, as well as sun-exposed and non-sun-exposed skin as a model system to investigate TJ protein alteration at various stages of tumorigenesis. We identified that a broader localization of zonula occludens protein (ZO)-1 and claudin-4 (Cldn-4) as well as downregulation of Cldn-1 in deeper epidermal layers is a frequent event in all the tumor entities as well as in sun-exposed skin, suggesting that these changes result from chronic UV irradiation. In contrast, SCC could be distinguished from the precursor tumors and sun-exposed skin by a frequent complete loss of occludin (Ocln). To elucidate the impact of down-regulation of Ocln, we performed Ocln siRNA experiments in human keratinocytes and uncovered that Ocln downregulation results in decreased epithelial cell-cell adhesion and reduced susceptibility to apoptosis induction by UVB or TNF-related apoptosis-inducing ligand (TRAIL), cellular characteristics for tumorigenesis. Furthermore, an influence on epidermal differentiation was observed, while there was no change of E-cadherin and vimentin, markers for epithelial-mesenchymal transition. Ocln knock-down altered Ca2+-homeostasis which may contribute to alterations of cell-cell adhesion and differentiation. As downregulation of Ocln is also seen in SCC derived from other tissues, as well as in other carcinomas, we suggest this as a common principle in tumor pathogenesis, which may be used as a target for therapeutic intervention. PMID:23390516

Beneficial Effects of the Genus Aloe on Wound Healing, Cell Proliferation, and Differentiation of Epidermal Keratinocytes

PubMed Central

Uda, Junki; Kubo, Hirokazu; Nakajima, Yuka; Goto, Arisa; Akaki, Junji; Yoshida, Ikuyo; Matsuoka, Nobuya; Hayakawa, Takao

2016-01-01

Aloe has been used as a folk medicine because it has several important therapeutic properties. These include wound and burn healing, and Aloe is now used in a variety of commercially available topical medications for wound healing and skin care. However, its effects on epidermal keratinocytes remain largely unclear. Our data indicated that both Aloe vera gel (AVG) and Cape aloe extract (CAE) significantly improved wound healing in human primary epidermal keratinocytes (HPEKs) and a human skin equivalent model. In addition, flow cytometry analysis revealed that cell surface expressions of β1-, α6-, β4-integrin, and E-cadherin increased in HPEKs treated with AVG and CAE. These increases may contribute to cell migration and wound healing. Treatment with Aloe also resulted in significant changes in cell-cycle progression and in increases in cell number. Aloe increased gene expression of differentiation markers in HPEKs, suggesting roles for AVG and CAE in the improvement of keratinocyte function. Furthermore, human skin epidermal equivalents developed from HPEKs with medium containing Aloe were thicker than control equivalents, indicating the effectiveness of Aloe on enhancing epidermal development. Based on these results, both AVG and CAE have benefits in wound healing and in treatment of rough skin. PMID:27736988

Suppression of Proinflammatory Cytokines in Functionalized Fullerene-Exposed Dermal Keratinocytes

DOE PAGES

Gao, Jun; Wang, Hsing-Lin; Iyer, Rashi

2010-01-01

Initial experiments using differentially functionalized fullerenes, CD-, hexa-, and tris-, suggested a properties dependent effect on cytotoxic and proliferative responses in human skin keratinocytes. In the present study we investigated the cytokine secretion profile of dermal epithelial cells exposed to functionalized fullerenes. Keratinocyte-derived cytokines affect homing and trafficking of normal and malignant epidermal immune as well as nonimmune cells in vivo. These cytokines are critical for regulating activation, proliferation, and differentiation of epidermal cells. Our results indicate that tris- (size range <100 nm) significantly reduces inflammatory cytokine release in a dose- and time-dependent manner. In contrast CD- demonstrated a relatively pro-inflammatorymore » cytokine response, while hexa- did not significantly perturb cytokine responses. Physical and chemical characterizations of these engineered nanomaterials suggest that the disparate biological responses observed may potentially be a function of the aggregation properties of these fullerenes.« less

Effects of ozone in normal human epidermal keratinocytes.

PubMed

McCarthy, James T; Pelle, Edward; Dong, Kelly; Brahmbhatt, Krupa; Yarosh, Dan; Pernodet, Nadine

2013-05-01

Ozone is a tropospheric pollutant that can form at ground level as a result of an interaction between sunlight and hydrocarbon engine emissions. As ozone is an extremely oxidative reaction product, epidermal cells are in the outer layer of defense against ozone. We exposed normal human epidermal keratinocytes (NHEK) to concentrations of ozone that have been measured in cities and assayed for its effects. Hydrogen peroxide and IL-1α levels both increased while ATP levels decreased. We found a decrease in the NAD-dependent histone deacetylase, sirtuin 3. Lastly, we found that ozone increased DNA damage as evaluated by Comet assay. Taken together, our results show increased damage to NHEK that will ultimately impair normal cellular function as a result of an environmentally relevant ozone exposure. © 2013 John Wiley & Sons A/S.

Cdc42 regulates junctional actin but not cell polarization in the Caenorhabditis elegans epidermis

PubMed Central

Zilberman, Yuliya; Abrams, Joshua; Anderson, Dorian C.

2017-01-01

During morphogenesis, adherens junctions (AJs) remodel to allow changes in cell shape and position while preserving adhesion. Here, we examine the function of Rho guanosine triphosphatase CDC-42 in AJ formation and regulation during Caenorhabditis elegans embryo elongation, a process driven by asymmetric epidermal cell shape changes. cdc-42 mutant embryos arrest during elongation with epidermal ruptures. Unexpectedly, we find using time-lapse fluorescence imaging that cdc-42 is not required for epidermal cell polarization or junction assembly, but rather is needed for proper junctional actin regulation during elongation. We show that the RhoGAP PAC-1/ARHGAP21 inhibits CDC-42 activity at AJs, and loss of PAC-1 or the interacting linker protein PICC-1/CCDC85A-C blocks elongation in embryos with compromised AJ function. pac-1 embryos exhibit dynamic accumulations of junctional F-actin and an increase in AJ protein levels. Our findings identify a previously unrecognized molecular mechanism for inhibiting junctional CDC-42 to control actin organization and AJ protein levels during epithelial morphogenesis. PMID:28903999

De novo epidermal regeneration using human eccrine sweat gland cells: higher competence of secretory over absorptive cells.

PubMed

Pontiggia, Luca; Biedermann, Thomas; Böttcher-Haberzeth, Sophie; Oliveira, Carol; Braziulis, Erik; Klar, Agnieszka S; Meuli-Simmen, Claudia; Meuli, Martin; Reichmann, Ernst

2014-06-01

In our previous work, we showed that human sweat gland-derived epithelial cells represent an alternative source of keratinocytes to grow a near normal autologous epidermis. The role of subtypes of sweat gland cells in epidermal regeneration and maintenance remained unclear. In this study, we compare the regenerative potential of both secretory and absorptive sweat gland cell subpopulations. We demonstrate the superiority of secretory over absorptive cells in forming a new epidermis on two levels: first, the proliferative and colony-forming efficiencies in vitro are significantly higher for secretory cells (SCs), and second, SCs show a higher frequency of successful epidermis formation as well as an increase in the thickness of the formed epidermis in the in vitro and in vivo functional analyses using a 3D dermo-epidermal skin model. However, the ability of forming functional skin substitutes is not limited to SCs, which supports the hypothesis that multiple subtypes of sweat gland epithelial cells hold regenerative properties, while the existence and exact localization of a keratinocyte stem cell population in the human eccrine sweat gland remain elusive.

Metalloprobes: Synthesis, Characterization, and Potency of a Novel Gallium(III) Complex in Human Epidermal Carcinoma Cells

PubMed Central

Harpstrite, Scott E.; Prior, Julie; Rath, Nigam P.; Sharma, Vijay

2009-01-01

Multidrug resistance (MDR) mediated by overexpression of the MDR1 gene product, P-glycoprotein (Pgp), represents one of the best characterized barriers to chemotherapeutic treatment in cancer and may be a pivotal factor in progression of Alzheimer’s disease (AD). Thus, agents capable of probing Pgp-mediated transport could be beneficial in biomedical imaging. Herein, we synthesized and structurally characterized a gallium(III) complex of the naphthol-Schiff base ligand (5). The crystal structure revealed octahedral geometry for the metallodrug. Cytotoxicity profiles of 5 were evaluated in KB-3-1 (Pgp−) and KB-8-5 (Pgp+) human epidermal carcinoma cell lines. Compared with an LC50 (the half-maximal cytotoxic concentration) value of 1.93 μM in drug-sensitive (Pgp−) cells, the gallium(III) complex 5 demonstrated an LC50 value > 100 μM in drug-resistant (Pgp+) cells, thus indicating that 5 was recognized by the Pgp as its substrate, thereby extruded from the cells and sequestered away from their cytotoxic targets. Radiolabeled analogues of 5 could be beneficial in noninvasive imaging of Pgp-mediated transport in vivo. PMID:17617464

Epidermal growth factor receptor and variant III targeted immunotherapy.

PubMed

Congdon, Kendra L; Gedeon, Patrick C; Suryadevara, Carter M; Caruso, Hillary G; Cooper, Laurence J N; Heimberger, Amy B; Sampson, John H

2014-10-01

Immunotherapeutic approaches to cancer have shown remarkable promise. A critical barrier to successfully executing such immune-mediated interventions is the selection of safe yet immunogenic targets. As patient deaths have occurred when tumor-associated antigens shared by normal tissue have been targeted by strong cellular immunotherapeutic platforms, route of delivery, target selection and the immune-mediated approach undertaken must work together to maximize efficacy with safety. Selected tumor-specific targets can spare potential toxicity to normal tissue; however, they are far less common than tumor-associated antigens and may not be present on all patients. In the context of immunotherapy for high-grade glioma, 2 of the most prominently studied antigens are the tumor-associated epidermal growth factor receptor and its tumor-specific genetic deletion variant III. In this review, we will summarize the immune-mediated strategies employed against these targets as well as the caveats particular to these approaches. © The Author(s) 2014. Published by Oxford University Press on behalf of the Society for Neuro-Oncology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

γδ T cells in homeostasis and host defence of epithelial barrier tissues.

PubMed

Nielsen, Morten M; Witherden, Deborah A; Havran, Wendy L

2017-12-01

Epithelial surfaces line the body and provide a crucial interface between the body and the external environment. Tissue-resident epithelial γδ T cells represent a major T cell population in the epithelial tissues and are ideally positioned to carry out barrier surveillance and aid in tissue homeostasis and repair. In this Review, we focus on the intraepithelial γδ T cell compartment of the two largest epithelial tissues in the body - namely, the epidermis and the intestine - and provide a comprehensive overview of the crucial contributions of intraepithelial γδ T cells to tissue integrity and repair, host homeostasis and protection in the context of the symbiotic relationship with the microbiome and during pathogen clearance. Finally, we describe epithelium-specific butyrophilin-like molecules and briefly review their emerging role in selectively shaping and regulating epidermal and intestinal γδ T cell repertoires.

Mitochondrial gene expression changes in cultured human skin cells following simulated sunlight irradiation.

PubMed

Kelly, J; Murphy, J E

2018-02-01

Exposure of skin to simulated sunlight irradiation (SSI) has being extensively researched and shown to be the main cause for changes in the skin including changes in cellular function and generation of reactive oxygen species (ROS). This oxidative stress can subsequently exert downstream effects and the subcellular compartments most affected by this oxidative stress are mitochondria. The importance of functional mitochondrial morphology is apparent as morphological defects are related to many human diseases including diabetes mellitus, liver disease, neurodegenerative diseases, aging and cancer. The main objective of this study was to evaluate solar radiation-induced changes in mitochondrial gene expression in human skin cells using a Q-Sun solar simulator to deliver a close match to the intensity of summer sunlight. Spontaneously immortalised human skin epidermal keratinocytes (HaCaT) and Human Dermal Fibroblasts (HDFn) were divided into two groups. Group A were irradiated once and Group B twice 7days apart; following irradiation, mitochondrial gene expression was evaluated 1, 4 and 7days post primary exposure for group A and 1, 4, 7 and 14days post-secondary exposure for group B. Both the epidermal and dermal cells displayed significant reduced expression of the genes analysed for mitochondrial morphology and function; however, epidermal cells displayed this reduction post SSI earlier then dermal cells at multiple time points. The data presented here reinforces the fact that epidermal cells, while displaying a heightened sensitivity to sunlight, are less prone to changes in gene expression, while dermal cells, which appear to be more resilient are possibly more prone to genomic instability and mitochondrial damage. Copyright © 2017 Elsevier B.V. All rights reserved.

Integrin beta 1 inhibition alleviates the chronic hyperproliferative dermatitis phenotype of SHARPIN-deficient mice.

PubMed

Peuhu, Emilia; Salomaa, Siiri I; De Franceschi, Nicola; Potter, Christopher S; Sundberg, John P; Pouwels, Jeroen

2017-01-01

SHARPIN (Shank-Associated RH Domain-Interacting Protein) is a component of the linear ubiquitin chain assembly complex (LUBAC), which enhances TNF-induced NF-κB activity. SHARPIN-deficient (Sharpincpdm/cpdm) mice display multi-organ inflammation and chronic proliferative dermatitis (cpdm) due to TNF-induced keratinocyte apoptosis. In cells, SHARPIN also inhibits integrins independently of LUBAC, but it has remained enigmatic whether elevated integrin activity levels in the dermis of Sharpincpdm/cpdm mice is due to increased integrin activity or is secondary to inflammation. In addition, the functional contribution of increased integrin activation to the Sharpincpdm/cpdm phenotype has not been investigated. Here, we find increased integrin activity in keratinocytes from Tnfr1-/- Sharpincpdm/cpdm double knockout mice, which do not display chronic inflammation or proliferative dermatitis, thus suggesting that SHARPIN indeed acts as an integrin inhibitor in vivo. In addition, we present evidence for a functional contribution of integrin activity to the Sharpincpdm/cpdm skin phenotype. Treatment with an integrin beta 1 function blocking antibody reduced epidermal hyperproliferation and epidermal thickness in Sharpincpdm/cpdm mice. Our data indicate that, while TNF-induced cell death triggers the chronic inflammation and proliferative dermatitis, absence of SHARPIN-dependent integrin inhibition exacerbates the epidermal hyperproliferation in Sharpincpdm/cpdm mice.

Reconstitution of full-thickness skin by microcolumn grafting.

PubMed

Tam, Joshua; Wang, Ying; Vuong, Linh N; Fisher, Jeremy M; Farinelli, William A; Anderson, R Rox

2017-10-01

In addition to providing a physical barrier, skin also serves a diverse range of physiological functions through different specialized resident cell types/structures, including melanocytes (pigmentation and protection against ultraviolet radiation), Langerhans cells (adaptive immunity), fibroblasts (maintaining extracellular matrix, paracrine regulation of keratinocytes), sweat glands (thermoregulation) and hair follicles (hair growth, sensation and a stem cell reservoir). Restoration of these functional elements has been a long-standing challenge in efforts to engineer skin tissue, while autologous skin grafting is limited by the scarcity of donor site skin and morbidity caused by skin harvesting. We demonstrate an alternative approach of harvesting and then implanting μm-scale, full-thickness columns of human skin tissue, which can be removed from a donor site with minimal morbidity and no scarring. Fresh human skin microcolumns were used to reconstitute skin in wounds on immunodeficient mice. The restored skin recapitulated many key features of normal human skin tissue, including epidermal architecture, diverse skin cell populations, adnexal structures and sweat production in response to cholinergic stimulation. These promising preclinical results suggest that harvesting and grafting of microcolumns may be useful for reconstituting fully functional skin in human wounds, without donor site morbidity. © 2016 The Authors Journal of Tissue Engineering and Regenerative Medicine Published by John Wiley & Sons Ltd. © 2016 The Authors Journal of Tissue Engineering and Regenerative Medicine Published by John Wiley & Sons Ltd.

Stimulation of hair follicle stem cell proliferation through an IL-1 dependent activation of γδT-cells

PubMed Central

Dutta, Abhik; Pincha, Neha; Rana, Isha; Ghosh, Subhasri; Witherden, Deborah; Kandyba, Eve; MacLeod, Amanda; Kobielak, Krzysztof; Havran, Wendy L

2017-01-01

The cutaneous wound-healing program is a product of a complex interplay among diverse cell types within the skin. One fundamental process that is mediated by these reciprocal interactions is the mobilization of local stem cell pools to promote tissue regeneration and repair. Using the ablation of epidermal caspase-8 as a model of wound healing in Mus musculus, we analyzed the signaling components responsible for epithelial stem cell proliferation. We found that IL-1α and IL-7 secreted from keratinocytes work in tandem to expand the activated population of resident epidermal γδT-cells. A downstream effect of activated γδT-cells is the preferential proliferation of hair follicle stem cells. By contrast, IL-1α-dependent stimulation of dermal fibroblasts optimally stimulates epidermal stem cell proliferation. These findings provide new mechanistic insights into the regulation and function of epidermal cell–immune cell interactions and into how components that are classically associated with inflammation can differentially influence distinct stem cell niches within a tissue. PMID:29199946

Virus-Induced Gene Silencing of the Eggplant Chalcone Synthase Gene during Fruit Ripening Modifies Epidermal Cells and Gravitropism.

PubMed

Wang, Cuicui; Fu, Daqi

2018-03-21

Eggplant ( Solanum melongena L.) fruits accumulate flavonoids in their cuticle and epidermal cells during ripening. Although many mutants available in model plant species, such as Arabidopsis thaliana and Medicago truncatula, are enabling the intricacies of flavonoid-related physiology to be deduced, the mechanisms whereby flavonoids influence eggplant fruit physiology are unknown. Virus-induced gene silencing (VIGS) is a reliable tool for the study of flavonoid function in fruit, and in this study, we successfully applied this technique to downregulate S. melongena chalcone synthase gene ( SmCHS) expression during eggplant fruit ripening. In addition to the expected change in fruit color attributable to a lack of anthocyanins, several other modifications, including differences in epidermal cell size and shape, were observed in the different sectors. We also found that silencing of CHS gene expression was associated with a negative gravitropic response in eggplant fruits. These observations indicate that epidermal cell expansion during ripening is dependent upon CHS expression and that there may be a relationship between CHS expression and gravitropism during eggplant fruit ripening.

UVB radiation generates sunburn pain and affects skin by activating epidermal TRPV4 ion channels and triggering endothelin-1 signaling

PubMed Central

Moore, Carlene; Cevikbas, Ferda; Pasolli, H. Amalia; Chen, Yong; Kong, Wei; Kempkes, Cordula; Parekh, Puja; Lee, Suk Hee; Kontchou, Nelly-Ange; Yeh, Iwei; Jokerst, Nan Marie; Fuchs, Elaine; Steinhoff, Martin; Liedtke, Wolfgang B.

2013-01-01

At our body surface, the epidermis absorbs UV radiation. UV overexposure leads to sunburn with tissue injury and pain. To understand how, we focus on TRPV4, a nonselective cation channel highly expressed in epithelial skin cells and known to function in sensory transduction, a property shared with other transient receptor potential channels. We show that following UVB exposure mice with induced Trpv4 deletions, specifically in keratinocytes, are less sensitive to noxious thermal and mechanical stimuli than control animals. Exploring the mechanism, we find that epidermal TRPV4 orchestrates UVB-evoked skin tissue damage and increased expression of the proalgesic/algogenic mediator endothelin-1. In culture, UVB causes a direct, TRPV4-dependent Ca2+ response in keratinocytes. In mice, topical treatment with a TRPV4-selective inhibitor decreases UVB-evoked pain behavior, epidermal tissue damage, and endothelin-1 expression. In humans, sunburn enhances epidermal expression of TRPV4 and endothelin-1, underscoring the potential of keratinocyte-derived TRPV4 as a therapeutic target for UVB-induced sunburn, in particular pain. PMID:23929777

UVB radiation generates sunburn pain and affects skin by activating epidermal TRPV4 ion channels and triggering endothelin-1 signaling.

PubMed

Moore, Carlene; Cevikbas, Ferda; Pasolli, H Amalia; Chen, Yong; Kong, Wei; Kempkes, Cordula; Parekh, Puja; Lee, Suk Hee; Kontchou, Nelly-Ange; Yeh, Iwei; Ye, Iwei; Jokerst, Nan Marie; Fuchs, Elaine; Steinhoff, Martin; Liedtke, Wolfgang B

2013-08-20

At our body surface, the epidermis absorbs UV radiation. UV overexposure leads to sunburn with tissue injury and pain. To understand how, we focus on TRPV4, a nonselective cation channel highly expressed in epithelial skin cells and known to function in sensory transduction, a property shared with other transient receptor potential channels. We show that following UVB exposure mice with induced Trpv4 deletions, specifically in keratinocytes, are less sensitive to noxious thermal and mechanical stimuli than control animals. Exploring the mechanism, we find that epidermal TRPV4 orchestrates UVB-evoked skin tissue damage and increased expression of the proalgesic/algogenic mediator endothelin-1. In culture, UVB causes a direct, TRPV4-dependent Ca(2+) response in keratinocytes. In mice, topical treatment with a TRPV4-selective inhibitor decreases UVB-evoked pain behavior, epidermal tissue damage, and endothelin-1 expression. In humans, sunburn enhances epidermal expression of TRPV4 and endothelin-1, underscoring the potential of keratinocyte-derived TRPV4 as a therapeutic target for UVB-induced sunburn, in particular pain.

Integrin-linked kinase and ELMO2 modulate recycling endosomes in keratinocytes.

PubMed

Ho, Ernest; Ivanova, Iordanka A; Dagnino, Lina

2016-12-01

The formation of tight cell-cell junctions is essential in the epidermis for its barrier properties. In this tissue, keratinocytes follow a differentiation program tightly associated with their movement from the innermost basal to the outer suprabasal layers, and with changes in their cell-cell adhesion profile. Intercellular adhesion in keratinocytes is mediated through cell-cell contacts, including E-cadherin-based adherens junctions. Although the mechanisms that mediate E-cadherin delivery to the plasma membrane have been widely studied in simple epithelia, this process is less well understood in the stratified epidermis. In this study, we have investigated the role of Engulfment and Cell Motility 2 (ELMO2) and integrin-linked kinase (ILK) in the positioning of E-cadherin-containing recycling endosomes during establishment of cell-cell contacts in differentiating keratinocytes. We now show that induction of keratinocyte differentiation by Ca 2+ is accompanied by localization of ELMO2 and ILK to Rab4- and Rab11a-containing recycling endosomes. The positioning of long-loop Rab11a-positive endosomes at areas adjacent to cell-cell contacts is disrupted in ELMO2- or ILK-deficient keratinocytes, and is associated with impaired localization of E-cadherin to cell borders. Our studies show a previously unrecognized role for ELMO2 and ILK in modulation of endosomal positioning, which may play key roles in epidermal sheet maintenance and permeability barrier function. Copyright © 2016 Elsevier B.V. All rights reserved.

Increased levels of inflammatory cytokines in the female reproductive tract are associated with altered expression of proteases, mucosal barrier proteins, and an influx of HIV-susceptible target cells.

PubMed

Arnold, Kelly B; Burgener, Adam; Birse, Kenzie; Romas, Laura; Dunphy, Laura J; Shahabi, Kamnoosh; Abou, Max; Westmacott, Garrett R; McCorrister, Stuart; Kwatampora, Jessie; Nyanga, Billy; Kimani, Joshua; Masson, Lindi; Liebenberg, Lenine J; Abdool Karim, Salim S; Passmore, Jo-Ann S; Lauffenburger, Douglas A; Kaul, Rupert; McKinnon, Lyle R

2016-01-01

Elevated inflammatory cytokines (EMCs) at mucosal surfaces have been associated with HIV susceptibility, but the underlying mechanisms remain unclear. We characterized the soluble mucosal proteome associated with elevated cytokine expression in the female reproductive tract. A scoring system was devised based on the elevation (upper quartile) of at least three of seven inflammatory cytokines in cervicovaginal lavage. Using this score, HIV-uninfected Kenyan women were classified as either having EMC (n=28) or not (n=68). Of 455 proteins quantified in proteomic analyses, 53 were associated with EMC (5% false discovery rate threshold). EMCs were associated with proteases, cell motility, and actin cytoskeletal pathways, whereas protease inhibitor, epidermal cell differentiation, and cornified envelope pathways were decreased. Multivariate analysis identified an optimal signature of 16 proteins that distinguished the EMC group with 88% accuracy. Three proteins in this signature were neutrophil-associated proteases that correlated with many cytokines, especially GM-CSF (granulocyte-macrophage colony-stimulating factor), IL-1β (interleukin-1β), MIP-3α (macrophage inflammatory protein-3α), IL-17, and IL-8. Gene set enrichment analyses implicated activated immune cells; we verified experimentally that EMC women had an increased frequency of endocervical CD4(+) T cells. These data reveal strong linkages between mucosal cytokines, barrier function, proteases, and immune cell movement, and propose these as potential mechanisms that increase risk of HIV acquisition.

Zebrafish grainyhead-like1 is a common marker of different non-keratinocyte epidermal cell lineages, which segregate from each other in a Foxi3-dependent manner

PubMed Central

JÄNICKE, MARTINA; RENISCH, BJÖRN; HAMMERSCHMIDT, MATTHIAS

2012-01-01

Grainyhead/CP2 transcription factor family members are widely conserved among the animal kingdom and have been implicated in different developmental processes. Thus far, nothing has been known about their roles in zebrafish. Here we identify seven zebrafish grainyhead-like (grhl) / cp2 genes, with focus on grhl1, which is expressed in the periderm and in epidermal ionocyte progenitors, but downregulated when ionocytes differentiate. In addition, expression was detected in other “non-keratinocyte” cell types of the epidermis, such as pvalb8-expressing cells, which according to our lineage tracing experiments are derived from the same pool of progenitor cells like keratinocytes and ionocytes. Antisense morpholino oligonucleotide-based loss-of-function analysis revealed that grhl1 is dispensable for the development and function of all investigated epidermal cell types, but required as a negative regulator of its own transcription during ionocyte differentiation. Knockdown of the transcription factor Foxi3a, which is expressed in a subset of the grhl1 population, caused a loss of ionocytes and a corresponding increase in the number of pvalb8-expressing cells, while leaving the number of grhl1-positive cells unaltered. We propose that grhl1 is a novel common marker of all or most “non-keratinocyte” epidermal progenitors, and that the sub-functionalisation of these cells is regulated by differential positive and negative effects of Foxi3 factors. PMID:19757382

An evaluation of the choice of feeder cell growth arrest for the production of cultured epidermis.

PubMed

Chugh, Rishi Man; Chaturvedi, Madhusudan; Yerneni, Lakshmana Kumar

2015-12-01

Growth arrested 3T3 cells have been used as feeder cells in human epidermal keratinocyte cultures to produce cultured epidermal autografts for the treatment of burns. The feeder cells were ideally growth-arrested by gamma-irradiation. Alternatively, growth arrest by mitomycin C treatment is a cost effective option. We compared the functional efficacy of these two approaches in keratinocyte cultures by colony forming efficiency, the net growth area of colonies, BrdU labeling and histological features of cultured epidermal sheets. The growth area estimation involved a semi-automated digital technique using the Adobe Photoshop and comprised of isolation and enumeration of red pixels in Rhodamine B-stained keratinocyte colonies. A further refinement of the technique led to the identification of critical steps to increasing the degree of accuracy and enabling its application as an extension of colony formation assay. The results on feeder cell functionality revealed that the gamma irradiated feeders influenced significantly higher colony forming efficiency and larger growth area than the mitomycin C treated feeders. The BrdU labeling study indicated significant stimulation of the overall keratinocyte proliferation by the gamma irradiated feeders. The cultured epidermal sheets produced by gamma feeders were relatively thicker than those produced by mitomycin C feeders. We discussed the clinical utility of mitomycin C feeders from the viewpoint of cost-effective burn care in developing countries. Copyright © 2015 Elsevier Ltd and ISBI. All rights reserved.

BAG-1 enhances cell-cell adhesion, reduces proliferation and induces chaperone-independent suppression of hepatocyte growth factor-induced epidermal keratinocyte migration

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hinitt, C.A.M.; Wood, J.; Lee, S.S.

2010-08-01

Cell motility is important in maintaining tissue homeostasis, facilitating epithelial wound repair and in tumour formation and progression. The aim of this study was to determine whether BAG-1 isoforms regulate epidermal cell migration in in vitro models of wound healing. In the human epidermal cell line HaCaT, endogenous BAG-1 is primarily nuclear and increases with confluence. Both transient and stable p36-Bag-1 overexpression resulted in increased cellular cohesion. Stable transfection of either of the three human BAG-1 isoforms p36-Bag-1 (BAG-1S), p46-Bag-1 (BAG-1M) and p50-Bag-1 (BAG-1L) inhibited growth and wound closure in serum-containing medium. However, in response to hepatocyte growth factor (HGF)more » in serum-free medium, BAG-1S/M reduced communal motility and colony scattering, but BAG-1L did not. In the presence of HGF, p36-Bag-1 transfectants retained proliferative response to HGF with no change in ERK1/2 activation. However, the cells retained E-cadherin localisation at cell-cell junctions and exhibited pronounced cortical actin. Point mutations in the BAG domain showed that BAG-1 inhibition of motility is independent of its function as a chaperone regulator. These findings are the first to suggest that BAG-1 plays a role in regulating cell-cell adhesion and suggest an important function in epidermal cohesion.« less

Assessment of the human epidermal model LabCyte EPI-MODEL for In vitro skin corrosion testing according to the OECD test guideline 431.

PubMed

Katoh, Masakazu; Hamajima, Fumiyasu; Ogasawara, Takahiro; Hata, Ken-Ichiro

2010-06-01

A new OECD test guideline 431 (TG431) for in vitro skin corrosion tests using human reconstructed skin models was adopted by OECD in 2004. TG431 defines the criteria for the general function and performance of applicable skin models. In order to confirm that the new reconstructed human epidermal model, LabCyte EPI-MODEL is applicable for the skin corrosion test according to TG431, the predictability and repeatability of the model for the skin corrosion test was evaluated. The test was performed according to the test protocol described in TG431. Based on the knowledge that LabCyte EPI-MODEL is an epidermal model as well as EpiDerm, we decided to adopt the the Epiderm prediction model of skin corrosion for the LabCyte EPI-MODEL, using twenty test chemicals (10 corrosive chemicals and 10 non-corrosive chemicals) in the 1(st) stage. The prediction model results showed that the distinction of non-corrosion to corrosion corresponded perfectly. Therefore, it was judged that the prediction model of EpiDerm could be applied to the LabCyte EPI-MODEL. In the 2(nd) stage, the repeatability of this test protocol with the LabCyte EPI-MODEL was examined using twelve chemicals (6 corrosive chemicals and 6 non-corrosive chemicals) that are described in TG431, and these results recognized a high repeatability and accurate predictability. It was concluded that LabCyte EPI-MODEL is applicable for the skin corrosive test protocol according to TG431.

Assessing the value of silicone and hydrocolloid products in stoma care.

PubMed

Berry, Jeanette; Black, Pat; Smith, Rory; Stuchfield, Barbara

Intact skin among many other functions provides a protective barrier between the body and its environment, which is critical in regulating transepidermal water loss (Wilkinson and Moor, 1982). The frequent application and removal of adhesives can damage skin by stripping away the outer epidermal layers. Older people, very young children and those with an underlying skin disorder may be particularly at risk (Gibelli et al, 1999; Lyons and Smith, 2003). Hydrocolloid adhesives, which hold moisture in the adhesive mass, are more skin friendly than the acrylic adhesives they now replace and have now become the material of choice for ostomy flanges and flange extenders (Smith et al, 2007). To understand stoma care nurses' awareness of the value of technologically advanced silicone and hydrocolloid products, the authors undertook a nationwide postal survey. The survey, commissioned by four companies in the United Kingdom, who make silicone and hydrocolloid products that can be used in stoma care, were keen to evaluate the awareness of these products to confirm their importance to the patient and why they should be appropriately categorized for reimbursement by the Department of Health.

Oral intake of Lactobacillus helveticus-fermented milk whey decreased transepidermal water loss and prevented the onset of sodium dodecylsulfate-induced dermatitis in mice.

PubMed

Baba, Hidehiko; Masuyama, Akihiro; Yoshimura, Chiaki; Aoyama, Yoshiko; Takano, Toshiaki; Ohki, Kohji

2010-01-01

We investigated the effects of oral intake of Lactobacillus helveticus-fermented milk whey on the intact and sodium dodecylsulfate (SDS)-exposed skin of Hos:HR-1 hairless mice. The mice were allowed to drink 10% L. helveticus-fermented milk whey in distilled water ad libitum for 5 weeks. SDS solution was topically applied to the dorsal skin at 4 weeks, leading to the development of dermatitis. The skin moisture content, transepidermal water loss, and sizes of the dermatitis areas were periodically measured. Compared with oral intake of water alone, oral intake of water containing L. helveticus-fermented milk whey for 4 weeks significantly lowered transepidermal water loss from intact skin, significantly reduced in size the areas of early SDS-induced dermatitis, and ameliorated both the SDS-induced decrease in moisture content and the increase in transepidermal water loss. These results suggest that oral intake of L. helveticus-fermented milk whey might be effective in promoting the epidermal barrier function and in preventing the onset of dermatitis.

Daily baseline skin care in the prevention, treatment, and supportive care of skin toxicity in oncology patients: recommendations from a multinational expert panel

PubMed Central

Bensadoun, René-Jean; Humbert, Phillipe; Krutman, Jean; Luger, Thomas; Triller, Raoul; Rougier, André; Seite, Sophie; Dreno, Brigitte

2013-01-01

Skin reactions due to radiotherapy and chemotherapy are a significant problem for an important number of cancer patients. While effective for treating cancer, they disturb cutaneous barrier function, causing a reaction soon after initiation of treatment that impacts patient quality of life. Managing these symptoms with cosmetics and nonpharmaceutical skin care products for camouflage or personal hygiene may be important for increasing patient self-esteem. However, inappropriate product choice or use could worsen side effects. Although recommendations exist for the pharmaceutical treatment of skin reactions, there are no recommendations for the choice or use of dermatologic skin care products for oncology patients. The present guidelines were developed by a board of European experts in dermatology and oncology to provide cancer care professionals with guidance for the appropriate use of non-pharmaceutical, dermocosmetic skin care management of cutaneous toxicities associated with radiotherapy and systemic chemotherapy, including epidermal growth factor inhibitors and monoclonal antibodies. The experts hope that these recommendations will improve the management of cutaneous side effects and hence quality of life for oncology patients. PMID:24353440

Neisseria gonorrhoeae breaches the apical junction of polarized epithelial cells for transmigration by activating EGFR

PubMed Central

Edwards, Vonetta L.; Wang, Liang-Chun; Dawson, Valerie; Stein, Daniel C.; Song, Wenxia

2017-01-01

Summary Neisseria gonorrhoeae initiates infection at the apical surface of columnar endocervical epithelial cells in the female reproductive tract. These cells provide a physical barrier against pathogens by forming continuous apical junctional complexes between neighbouring cells. This study examines the interaction of gonococci (GC) with polarized epithelial cells. We show that viable GC preferentially localize at the apical side of the cell–cell junction in polarized endometrial and colonic epithelial cells, HEC-1-B and T84. In GC-infected cells, continuous apical junctional complexes are disrupted, and the junction-associated protein β-catenin is redistributed from the apical junction to the cytoplasm and to GC adherent sites; however, overall cellular levels remain unchanged. This redistribution of junctional proteins is associated with a decrease in the ‘fence’ function of the apical junction but not its ‘gate’ function. Disruption of the apical junction by removing calcium increases GC transmigration across the epithelial monolayer. GC inoculation induces the phosphorylation of both epidermal growth factor receptor (EGFR) and β-catenin, while inhibition of EGFR kinase activity significantly reduces both GC-induced β-catenin redistribution and GC transmigration. Therefore, the gonococcus is capable of weakening the apical junction and polarity of epithelial cells by activating EGFR, which facilitates GC transmigration across the epithelium. PMID:23279089

Posttraumatic stress disorder (PTSD) and the dermatology patient.

PubMed

Gupta, Madhulika A; Jarosz, Patricia; Gupta, Aditya K

Dermatologic symptoms can be associated with posttraumatic stress disorder (PTSD) in several situations: (1) as features of some core PTSD symptoms, such as intrusion symptoms manifesting as cutaneous sensory flashbacks, as autonomic arousal manifesting as night sweats and idiopathic urticaria, and as dissociation manifesting as numbness and dermatitis artefacta; (2) the cutaneous psychosomatic effects of emotional and physical neglect and sexual abuse (eg, infantile eczema, cutaneous self-injury, and body-focused repetitive behaviors such as trichotillomania and skin picking disorder) and eating disorders, which can have dermatologic effects; (3) the direct effect of physical or sexual abuse or catastrophic life events (eg, earthquakes) on the skin; and (4) as a result of significant alterations in hypothalamic-pituitary-adrenal and sympatho-adrenal medullary axes, which can affect neuroendocrine and immune functions, and can lead to exacerbations of stress-reactive inflammatory dermatoses such as psoriasis, chronic urticaria, and atopic dermatitis. Elevated levels of inflammatory biomarkers and impaired epidermal barrier function have been reported in situations involving sustained psychologic stress and sleep deprivation. Some PTSD patients show hypothalamic-pituitary-adrenal axis hyporesponsiveness and higher circulating T lymphocytes, which can exacerbate immune-mediated dermatologic disorders. PTSD should be considered an underlying factor in the chronic, recurrent, or treatment-resistant stress-reactive dermatoses and in patients with self-induced dermatoses. Copyright © 2017 Elsevier Inc. All rights reserved.

Spatial and temporal expression of the Grainyhead-like transcription factor family during murine development.

PubMed

Auden, Alana; Caddy, Jacinta; Wilanowski, Tomasz; Ting, Stephen B; Cunningham, John M; Jane, Stephen M

2006-10-01

The Drosophila transcription factor Grainyhead (grh) is expressed in ectoderm-derived tissues where it regulates several key developmental events including cuticle formation, tracheal elongation and dorsal closure. Our laboratory has recently identified three novel mammalian homologues of the grh gene, Grainyhead-like 1, -2 and -3 (Grhl1-3) that rewrite the phylogeny of this family. Using gene targeting in mice, we have shown that Grhl3 is essential for neural tube closure, skin barrier formation and wound healing. Despite their extensive sequence homology, Grhl1 and Grhl2 are unable to compensate for loss of Grhl3 in these developmental processes. To explore this lack of redundancy, and to gain further insights into the functions of this gene family in mammalian development we have performed an extensive in situ hybridisation analysis. We demonstrate that, although all three Grhl genes are highly expressed in the developing epidermis, they display subtle differences in the timing and level of expression. Surprisingly, we also demonstrate differential expression patterns in non-ectoderm-derived tissues, including the heart, the lung, and the metanephric kidney. These findings expand our understanding of the unique role of Grhl3 in neurulation and epidermal morphogenesis, and provide a focus for further functional analysis of the Grhl genes during mouse embryogenesis.

Temperature-induced unfolding of epidermal growth factor (EGF): insight from molecular dynamics simulation

PubMed Central

Yan, Chunli; Pattani, Varun; Tunnell, James W.; Ren, Pengyu

2010-01-01

Thermal disruption of protein structure and function is a potentially powerful therapeutic vehicle. With the emerging nanoparticle-targeting and femtosecond laser technology, it is possible to deliver heating locally to specific molecules. It is therefore important to understand how fast a protein can unfold or lose its function at high temperatures, such as near the water boiling point. In this study, the thermal damage of EGF was investigated by combining the replica exchange (136 replicas) and conventional molecular dynamics simulations. The REMD simulation was employed to rigorously explore the free energy landscape of EGF unfolding. Interestingly, besides the native and unfolded states, we also observed a distinct molten globule (MG) state that retained substantial amount of native contacts. Based on the understanding that which the unfolding of EGF is a three-state process, we have examined the unfolding kinetics of EGF (N→ MG→h multiple 20-ns conventional MD simulations. The Arrhenius prefactors and activation energy barriers determined from the simulation are within the range of previously studied proteins. In contrast to the thermal damage of cells and tissues which take place on the time scale of seconds to hours at relatively low temperatures, the denaturation of proteins occur in nanoseconds when the temperature of heat bath approaches the boiling point. PMID:20466569

Epidermal PPARγ influences subcutaneous tumor growth and acts through TNF-α to regulate contact hypersensitivity and the acute photoresponse

PubMed Central

Konger, Raymond L.; Derr-Yellin, Ethel; Travers, Jeffrey B.; Ocana, Jesus A.; Sahu, Ravi P.

2017-01-01

It is known that ultraviolet B (UVB) induces PPARγ ligand formation while loss of murine epidermal PPARγ (Pparg-/-epi) promotes UVB-induced apoptosis, inflammation, and carcinogenesis. PPARγ is known to suppress tumor necrosis factor-α (TNF-α) production. TNF-α is also known to promote UVB-induced inflammation, apoptosis, and immunosuppression. We show that Pparg-/-epi mice exhibit increased baseline TNF-α expression. Neutralizing Abs to TNF-α block the increased photo-inflammation and photo-toxicity that is observed in Pparg-/-epi mouse skin. Interestingly, the increase in UVB-induced apoptosis in Pparg-/-epi mice is not accompanied by a change in cyclobutane pyrimidine dimer clearance or in mutation burden. This suggests that loss of epidermal PPARγ does not result in a significant alteration in DNA repair capacity. However, loss of epidermal PPARγ results in marked immunosuppression using a contact hypersensitivity (CHS) model. This impaired CHS response was significantly alleviated using neutralizing TNF-α antibodies or loss of germline Tnf. In addition, the PPARγ agonist rosiglitazone reversed UVB-induced systemic immunosuppression (UV-IS) as well as UV-induced growth of B16F10 melanoma tumor cells in syngeneic mice. Finally, increased B16F10 tumor growth was observed when injected subcutaneously into Pparg-/-epi mice. Thus, we provide novel evidence that epidermal PPARγ is important for cutaneous immune function and the acute photoresponse. PMID:29228682

RNA-seq Analysis of Host and Viral Gene Expression Highlights Interaction between Varicella Zoster Virus and Keratinocyte Differentiation

PubMed Central

Singh, Manuraj; Kanda, Ravinder K.; Yee, Michael B.; Kellam, Paul; Hollinshead, Michael; Kinchington, Paul R.; O'Toole, Edel A.; Breuer, Judith

2014-01-01

Varicella zoster virus (VZV) is the etiological agent of chickenpox and shingles, diseases characterized by epidermal skin blistering. Using a calcium-induced keratinocyte differentiation model we investigated the interaction between epidermal differentiation and VZV infection. RNA-seq analysis showed that VZV infection has a profound effect on differentiating keratinocytes, altering the normal process of epidermal gene expression to generate a signature that resembles patterns of gene expression seen in both heritable and acquired skin-blistering disorders. Further investigation by real-time PCR, protein analysis and electron microscopy revealed that VZV specifically reduced expression of specific suprabasal cytokeratins and desmosomal proteins, leading to disruption of epidermal structure and function. These changes were accompanied by an upregulation of kallikreins and serine proteases. Taken together VZV infection promotes blistering and desquamation of the epidermis, both of which are necessary to the viral spread and pathogenesis. At the same time, analysis of the viral transcriptome provided evidence that VZV gene expression was significantly increased following calcium treatment of keratinocytes. Using reporter viruses and immunohistochemistry we confirmed that VZV gene and protein expression in skin is linked with cellular differentiation. These studies highlight the intimate host-pathogen interaction following VZV infection of skin and provide insight into the mechanisms by which VZV remodels the epidermal environment to promote its own replication and spread. PMID:24497829

Gromwell (Lithospermum erythrorhizon) supplementation enhances epidermal levels of ceramides, glucosylceramides, β-glucocerebrosidase, and acidic sphingomyelinase in NC/Nga mice.

PubMed

Kim, Jungmin; Cho, Yunhi

2013-10-01

We have previously reported that dietary gromwell (Lithospermum erythrorhizon; LE) prevents the development of atopic dermatitis (AD) with increased epidermal levels of total ceramide (Cer), the major lipid maintaining epidermal barrier. In this study, we investigated whether the increased level of total Cer induced by dietary LE would be related to the altered metabolism of glucosylceramide (GlcCer) and sphingomyelin (SM), two major precursor lipids in Cer generation. NC/Nga mice, an animal model of AD, were fed a control diet (group CA: atopic control) or a diet with 70% ethanol LE extracts (1% in diet; group LE) for 10 weeks. Individual species of Cer, GlcCer, and SM were analyzed by high-performance thin layer chromatography. In the epidermis of group CA, total Cer (including Cer2 and Cer5-7) and total GlcCer (including GlcCer-B/C/D) were significantly reduced; these levels in group LE were increased to levels similar to the normal control group of BALB/c mice (group C). In addition, protein expressions and activities of β-glucocerebrosidase (β-GlcCer'ase) and acidic sphingomyelinase (aSMase), enzymes for GlcCer or SM hydrolysis, respectively, were increased in group LE. However, alterations of Cer1, Cer3/4, GlcCer-A, and all SM species (including SM1-3) were not significant among groups C, CA, and LE. Dietary gromwell increases GlcCer-B/C/D, and further enhances the generation of Cer2 and Cer5-7 with high protein expressions and activities of β-GlcCer'ase and aSMase.

Nucleolin inhibitor GroA triggers reduction in epidermal growth factor receptor activation: Pharmacological implication for glial scarring after spinal cord injury.

PubMed

Goldshmit, Yona; Schokoroy Trangle, Sari; Afergan, Fabian; Iram, Tal; Pinkas-Kramarski, Ronit

2016-09-01

Glial scarring, formed by reactive astrocytes, is one of the major impediments for regeneration after spinal cord injury (SCI). Reactive astrocytes become hypertrophic, proliferate and secrete chondroitin sulphate proteoglycans into the extracellular matrix (ECM). Many studies have demonstrated that epidermal growth factor receptors (EGFR) can mediate astrocyte reactivity after neurotrauma. Previously we showed that there is crosstalk between nucleolin and EGFR that leads to increased EGFR activation followed by increased cell proliferation. Treatment with the nucleolin inhibitor GroA (AS1411) prevented these effects in vitro and in vivo. In this study, we hypothesized that similar interactions may mediate astrogliosis after SCI. Our results demonstrate that nucleolin and EGFR interaction may play a pivotal role in mediating astrocyte proliferation and reactivity after SCI. Moreover, we demonstrate that treatment with GroA reduces EGFR activation, astrocyte proliferation and chondroitin sulphate proteoglycans secretion, therefore promoting axonal regeneration and sprouting into the lesion site. Our results identify, for the first time, a role for the interaction between nucleolin and EGFR in astrocytes after SCI, indicating that nucleolin inhibitor GroA may be used as a novel treatment after neurotrauma. A major barrier for axonal regeneration after spinal cord injury is glial scar created by reactive and proliferating astrocytes. EGFR mediate astrocyte reactivity. We showed that inhibition of nucleolin by GroA, reduces EGFR activation, which results in attenuation of astrocyte reactivity and proliferation in vivo and in vitro. EGFR, epidermal growth factor receptor. © 2016 International Society for Neurochemistry.

Heparinoid suppresses Der p-induced IL-1β production by inhibiting ERK and p38 MAPK pathways in keratinocytes.

PubMed

Utsunomiya, Ryo; Dai, Xiuju; Murakami, Masamoto; Okazaki, Hidenori; Tsuda, Teruko; Mori, Hideki; Shiraishi, Ken; Tohyama, Mikiko; Sayama, Koji

2018-05-13

Epidermal keratinocytes initiate skin inflammation by activating immune cells. The skin barrier is disrupted in atopic dermatitis (AD) and epidermal keratinocytes can be exposed to environmental stimuli, such as house dust mite (HDM) allergens. We showed previously that HDM allergens activate the NLRP3 inflammasome of keratinocytes, thereby releasing pro-inflammatory cytokines. Heparinoid is an effective moisturizer for atopic dry skin. However, a recent report showed that heparinoid treatment can improve inflammation of lichen planus. Therefore, we hypothesized that it acts on epidermal keratinocytes not only as a moisturizer, but also as a suppressant of the triggers of skin inflammation. We found that HDM allergen-induced interleukin (IL)-1β release from keratinocytes was inhibited significantly by heparinoid pretreatment without affecting cell viability. However, heparinoid did not affect caspase-1 release, suggesting that heparinoid did not affect HDM allergen-induced inflammasome activation. Heparinoid treatment not only decreased intracellular levels of pro-IL-1β, but also suppressed IL-1β messenger RNA (mRNA) expression in keratinocytes. Among the intracellular signaling pathways, the activation of extracellular signal-regulated kinase and p38 pathways, which are required for IL-1β expression in keratinocytes, was inhibited by heparinoid treatment. The inhibitory effect of heparinoid on IL-1β mRNA expression was also confirmed with living skin equivalents. Our results demonstrated that heparinoid suppresses the initiation of keratinocyte-mediated skin inflammation. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Epidermal 'alarm substance' cells of fishes maintained by non-alarm functions: possible defence against pathogens, parasites and UVB radiation.

PubMed

Chivers, Douglas P; Wisenden, Brian D; Hindman, Carrie J; Michalak, Tracy A; Kusch, Robin C; Kaminskyj, Susan G W; Jack, Kristin L; Ferrari, Maud C O; Pollock, Robyn J; Halbgewachs, Colin F; Pollock, Michael S; Alemadi, Shireen; James, Clayton T; Savaloja, Rachel K; Goater, Cameron P; Corwin, Amber; Mirza, Reehan S; Kiesecker, Joseph M; Brown, Grant E; Adrian, James C; Krone, Patrick H; Blaustein, Andrew R; Mathis, Alicia

2007-10-22

Many fishes possess specialized epidermal cells that are ruptured by the teeth of predators, thus reliably indicating the presence of an actively foraging predator. Understanding the evolution of these cells has intrigued evolutionary ecologists because the release of these alarm chemicals is not voluntary. Here, we show that predation pressure does not influence alarm cell production in fishes. Alarm cell production is stimulated by exposure to skin-penetrating pathogens (water moulds: Saprolegnia ferax and Saprolegnia parasitica), skin-penetrating parasites (larval trematodes: Teleorchis sp. and Uvulifer sp.) and correlated with exposure to UV radiation. Suppression of the immune system with environmentally relevant levels of Cd inhibits alarm cell production of fishes challenged with Saprolegnia. These data are the first evidence that alarm substance cells have an immune function against ubiquitous environmental challenges to epidermal integrity. Our results indicate that these specialized cells arose and are maintained by natural selection owing to selfish benefits unrelated to predator-prey interactions. Cell contents released when these cells are damaged in predator attacks have secondarily acquired an ecological role as alarm cues because selection favours receivers to detect and respond adaptively to public information about predation.

Tissue-Specific Profiling Reveals Transcriptome Alterations in Arabidopsis Mutants Lacking Morphological Phenotypes[C][W

PubMed Central

Simon, Marissa; Bruex, Angela; Kainkaryam, Raghunandan M.; Zheng, Xiaohua; Huang, Ling; Woolf, Peter J.; Schiefelbein, John

2013-01-01

Traditional genetic analysis relies on mutants with observable phenotypes. Mutants lacking visible abnormalities may nevertheless exhibit molecular differences useful for defining gene function. To examine this, we analyzed tissue-specific transcript profiles from Arabidopsis thaliana transcription factor gene mutants with known roles in root epidermis development, but lacking a single-gene mutant phenotype due to genetic redundancy. We discovered substantial transcriptional changes in each mutant, preferentially affecting root epidermal genes in a manner consistent with the known double mutant effects. Furthermore, comparing transcript profiles of single and double mutants, we observed remarkable variation in the sensitivity of target genes to the loss of one or both paralogous genes, including preferential effects on specific branches of the epidermal gene network, likely reflecting the pathways of paralog subfunctionalization during evolution. In addition, we analyzed the root epidermal transcriptome of the transparent testa glabra2 mutant to clarify its role in the network. These findings provide insight into the molecular basis of genetic redundancy and duplicate gene diversification at the level of a specific gene regulatory network, and they demonstrate the usefulness of tissue-specific transcript profiling to define gene function in mutants lacking informative visible changes in phenotype. PMID:24014549

A data mining paradigm for identifying key factors in biological processes using gene expression data.

PubMed

Li, Jin; Zheng, Le; Uchiyama, Akihiko; Bin, Lianghua; Mauro, Theodora M; Elias, Peter M; Pawelczyk, Tadeusz; Sakowicz-Burkiewicz, Monika; Trzeciak, Magdalena; Leung, Donald Y M; Morasso, Maria I; Yu, Peng

2018-06-13

A large volume of biological data is being generated for studying mechanisms of various biological processes. These precious data enable large-scale computational analyses to gain biological insights. However, it remains a challenge to mine the data efficiently for knowledge discovery. The heterogeneity of these data makes it difficult to consistently integrate them, slowing down the process of biological discovery. We introduce a data processing paradigm to identify key factors in biological processes via systematic collection of gene expression datasets, primary analysis of data, and evaluation of consistent signals. To demonstrate its effectiveness, our paradigm was applied to epidermal development and identified many genes that play a potential role in this process. Besides the known epidermal development genes, a substantial proportion of the identified genes are still not supported by gain- or loss-of-function studies, yielding many novel genes for future studies. Among them, we selected a top gene for loss-of-function experimental validation and confirmed its function in epidermal differentiation, proving the ability of this paradigm to identify new factors in biological processes. In addition, this paradigm revealed many key genes in cold-induced thermogenesis using data from cold-challenged tissues, demonstrating its generalizability. This paradigm can lead to fruitful results for studying molecular mechanisms in an era of explosive accumulation of publicly available biological data.

Overexpression of Transcription Factor Sp2 Inhibits Epidermal Differentiation and Increases Susceptibility to Wound and Carcinogen-Induced Tumorigenesis

PubMed Central

Kim, Tae-Hyung; Chiera, Shannon L.; Linder, Keith E.; Trempus, Carol S.; Smart, Robert C.; Horowitz, Jonathan M.

2010-01-01

Sp proteins are evolutionarily-conserved transcription factors required for the expression of a wide variety of genes that are critical for development and cell-cycle progression. De-regulated expression of certain Sp proteins is associated with the formation of a variety of human tumors, however direct evidence that any given Sp protein is oncogenic has been lacking. Here we report that Sp2 protein abundance in mice increases in concert with the progression of carcinogen-induced murine squamous cell carcinomas. Transgenic mice specifically overexpressing murine Sp2 in epidermal basal keratinocytes were highly susceptible to wound- and carcinogen-induced papillomagenesis. Transgenic animals that were homozygous rather than hemizygous for the Sp2 transgene exhibited a striking arrest in the epidermal differentiation program, perishing within two weeks of birth. Our results directly support the likelihood that Sp2 overexpression occurring in various human cancers has significant functional impact. PMID:20959487

Thrombomodulin exerts cytoprotective effect on low-dose UVB-irradiated HaCaT cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Iwata, Masahiro; Laboratory of Vascular Medicine, Department of Cardiovascular and Respiratory Disorders Advanced Therapeutics, Kagoshima University Graduate School of Medical and Dental Sciences, 8-35-1 Sakuragaoka, Kagoshima 890-8520; Kawahara, Ko-ichi

Thrombomodulin (TM) is an endothelial cell surface anticoagulant glycoprotein that performs antimetastatic, angiogenic, adhesive, and anti-inflammatory functions in various tissues. It is also expressed in epidermal keratinocytes. We found that a physiological dose (10 mJ/cm{sup 2}) of mid-wavelength ultraviolet irradiation (UVB) significantly induced TM expression via the p38mitogen-activated protein kinase (MAPK)/cyclic AMP response element (CRE) signaling pathway in the epidermal keratinocyte cell line HaCaT; this shows that TM regulates the survival of HaCaT cells. SB203580, a p38MAPK inhibitor, significantly decreased TM expression and the viability of cells exposed to UVB. Furthermore, overexpression of TM markedly increased cell viability, and itmore » was abrogated by TM small interfering RNA (siRNA), suggesting that TM may play an important role in exerting cytoprotective effect on epidermal keratinocytes against low-dose UVB.« less

Clinical Nonlinear Laser Imaging of Human Skin: A Review

PubMed Central

Pavone, Francesco Saverio

2014-01-01

Nonlinear optical microscopy has the potential of being used in vivo as a noninvasive imaging modality for both epidermal and dermal imaging. This paper reviews the capabilities of nonlinear microscopy as a noninvasive high-resolution tool for clinical skin inspection. In particular, we show that two-photon fluorescence microscopy can be used as a diagnostic tool for characterizing epidermal layers by means of a morphological examination. Additional functional information on the metabolic state of cells can be provided by measuring the fluorescence decay of NADH. This approach allows differentiating epidermal layers having different structural and cytological features and has the potential of diagnosing pathologies in a very early stage. Regarding therapy follow-up, we demonstrate that nonlinear microscopy could be successfully used for monitoring the effect of a treatment. In particular, combined two-photon fluorescence and second-harmonic generation microscopy were used in vivo for monitoring collagen remodeling after microablative fractional laser resurfacing and for quantitatively monitoring psoriasis on the basis of the morphology of epidermal cells and dermal papillae. We believe that the described microscopic modalities could find in the near future a stable place in a clinical dermatological setting for quantitative diagnostic purposes and as a monitoring method for various treatments. PMID:25250337

Body wiping behaviors associated with cutaneous lipids in hylid tree frogs of Florida.

PubMed

Barbeau, Tamatha R; Lillywhite, Harvey B

2005-06-01

Body wiping behavior, integumentary secretions and rates of evaporative water loss (EWL) were examined in six species of Florida tree frogs (Anura: Hylidae). Additionally, morphology of the integument and dermal glands were compared among these and one other Florida tree frog (Hyla andersonii), an arid-adapted tree frog (Phyllomedusa hypochondrialis), and a highly aquatic frog (Rana utricularia). An extra-epidermal layer of lipid and mucus, presumably secreted from dermal granular glands, was detected on the skin of all Florida hylid frogs examined. Distinct body wiping behaviors were observed in the hylid frogs, but these were less complex than those described previously in phyllomedusine frogs, which occupy arid habitats, secrete lipids onto their skin, and are regarded as relatively 'waterproof'. Florida hylids occupy seasonally arid habitats and appear to have reduced rates of EWL. The suite of traits we observed in these frogs have been previously documented in a rhacophorid tree frog from seasonally arid regions of India and likely represent an evolutionary convergent response to periodic dehydration stress. The presence of lipids that are spread by simple wiping behaviors to form an extra-epidermal water barrier may represent an early stage of the more advanced adaptations described in more waterproof arboreal frogs.

Targeted Therapies for Brain Metastases from Breast Cancer.

PubMed

Venur, Vyshak Alva; Leone, José Pablo

2016-09-13

The discovery of various driver pathways and targeted small molecule agents/antibodies have revolutionized the management of metastatic breast cancer. Currently, the major targets of clinical utility in breast cancer include the human epidermal growth factor receptor 2 (HER2) and epidermal growth factor receptor (EGFR), vascular endothelial growth factor (VEGF) receptor, mechanistic target of rapamycin (mTOR) pathway, and the cyclin-dependent kinase 4/6 (CDK-4/6) pathway. Brain metastasis, however, remains a thorn in the flesh, leading to morbidity, neuro-cognitive decline, and interruptions in the management of systemic disease. Approximately 20%-30% of patients with metastatic breast cancer develop brain metastases. Surgery, whole brain radiation therapy, and stereotactic radiosurgery are the traditional treatment options for patients with brain metastases. The therapeutic paradigm is changing due to better understanding of the blood brain barrier and the advent of tyrosine kinase inhibitors and monoclonal antibodies. Several of these agents are in clinical practice and several others are in early stage clinical trials. In this article, we will review the common targetable pathways in the management of breast cancer patients with brain metastases, and the current state of the clinical development of drugs against these pathways.

Angiotensin-converting enzyme inhibitor (enalapril maleate) accelerates recovery of mouse skin from UVB-induced wrinkles.

PubMed

Matsuura-Hachiya, Yuko; Arai, Koji Y; Ozeki, Rieko; Kikuta, Ayako; Nishiyama, Toshio

2013-12-06

Angiotensin-converting enzyme (ACE) activity and angiotensin II signaling regulate cell proliferation, differentiation, and tissue remodeling, as well as blood pressure, while in skin, angiotensin II signaling is involved in wound healing, inflammation, and pathological scar formation. Therefore, we hypothesized that angiotensin II is also involved in photoaging of skin. In this study, we examined the effect of enalapril maleate, an ACE inhibitor, on recovery of wrinkled skin of hairless mice exposed to long-term UVB irradiation. Immunohistochemical observation revealed that expression of ACE, angiotensin II, and angiotensin II type 1 (AT1) and type 2 (AT2) receptors in the skin was increased after UVB irradiation (3 times/week at increasing intensities for 8 weeks). Administration of enalapril maleate (5 times/week for 6 weeks, starting 1 week after 10-week irradiation) accelerated recovery from UVB-induced wrinkles, epidermal hyperplasia and epidermal barrier dysfunction, as compared with the vehicle control. Our results indicate that ACE and angiotensin II activity are involved in skin photoaging, and suggest that ACE inhibitor such as enalapril maleate may have potential for improvement of photoaged skin. Copyright © 2013 Elsevier Inc. All rights reserved.

Control of E-cadherin apical localisation and morphogenesis by a SOAP-1/AP-1/clathrin pathway in C. elegans epidermal cells.

PubMed

Gillard, Ghislain; Shafaq-Zadah, Massiullah; Nicolle, Ophélie; Damaj, Raghida; Pécréaux, Jacques; Michaux, Grégoire

2015-05-01

E-cadherin (E-cad) is the main component of epithelial junctions in multicellular organisms, where it is essential for cell-cell adhesion. The localisation of E-cad is often strongly polarised in the apico-basal axis. However, the mechanisms required for its polarised distribution are still largely unknown. We performed a systematic RNAi screen in vivo to identify genes required for the strict E-cad apical localisation in C. elegans epithelial epidermal cells. We found that the loss of clathrin, its adaptor AP-1 and the AP-1 interactor SOAP-1 induced a basolateral localisation of E-cad without affecting the apico-basal diffusion barrier. We further found that SOAP-1 controls AP-1 localisation, and that AP-1 is required for clathrin recruitment. Finally, we also show that AP-1 controls E-cad apical delivery and actin organisation during embryonic elongation, the final morphogenetic step of embryogenesis. We therefore propose that a molecular pathway, containing SOAP-1, AP-1 and clathrin, controls the apical delivery of E-cad and morphogenesis. © 2015. Published by The Company of Biologists Ltd.

Race Does Not Predict Melanocyte Heterogeneous Responses to Dermal Fibroblast-Derived Mediators

PubMed Central

Sirimahachaiyakul, Pornthep; Sood, Ravi F.; Muffley, Lara A.; Seaton, Max; Lin, Cheng-Ta; Qiao, Liang; Armaly, Jeffrey S.; Hocking, Anne M.; Gibran, Nicole S.

2015-01-01

Introduction Abnormal pigmentation following cutaneous injury causes significant patient distress and represents a barrier to recovery. Wound depth and patient characteristics influence scar pigmentation. However, we know little about the pathophysiology leading to hyperpigmentation in healed shallow wounds and hypopigmentation in deep dermal wound scars. We sought to determine whether dermal fibroblast signaling influences melanocyte responses. Methods and Materials Epidermal melanocytes from three Caucasians and three African-Americans were genotyped for single nucleotide polymorphisms (SNPs) across the entire genome. Melanocyte genetic profiles were determined using principal component analysis. We assessed melanocyte phenotype and gene expression in response to dermal fibroblast-conditioned medium and determined potential mesenchymal mediators by proteome profiling the fibroblast-conditioned medium. Results Six melanocyte samples demonstrated significant variability in phenotype and gene expression at baseline and in response to fibroblast-conditioned medium. Genetic profiling for SNPs in receptors for 13 identified soluble fibroblast-secreted mediators demonstrated considerable heterogeneity, potentially explaining the variable melanocyte responses to fibroblast-conditioned medium. Discussion Our data suggest that melanocytes respond to dermal fibroblast-derived mediators independent of keratinocytes and raise the possibility that mesenchymal-epidermal interactions influence skin pigmentation during cutaneous scarring. PMID:26418010

ΔNp63 is an ectodermal gatekeeper of epidermal morphogenesis

PubMed Central

Shalom-Feuerstein, R; Lena, A M; Zhou, H; De La Forest Divonne, S; Van Bokhoven, H; Candi, E; Melino, G; Aberdam, D

2011-01-01

p63, a member of p53 family, has a significant role in the development and maintenance of stratified epithelia. However, a persistent dispute remained over the last decade concerning the interpretation of the severe failure of p63-null embryos to develop stratified epithelia. In this study, by investigating both p63-deficient strains, we demonstrated that p63-deficient epithelia failed to develop beyond ectodermal stage as they remained a monolayer of non-proliferating cells expressing K8/K18. Importantly, in the absence of p63, corneal-epithelial commitment (which occurs at embryonic day 12.5 of mouse embryogenesis) was hampered 3 weeks before corneal stem cell renewal (that begins at P14). Taken together, these data illustrate the significant role of p63 in epithelial embryogenesis, before and independently of other functions of p63 in adult stem cells regulation. Transcriptome analysis of laser captured-embryonic tissues confirmed the latter hypothesis, demonstrating that a battery of epidermal genes that were activated in wild-type epidermis remained silent in p63-null tissues. Furthermore, we defined a subset of novel bona fide p63-induced genes orchestrating first epidermal stratification and a subset of p63-repressed mesodermal-specific genes. These data highlight the earliest recognized action of ΔNp63 in the induction epidermal morphogenesis at E11.5. In the absence of p63, a mesodermal program is activated while epidermal morphogenesis does not initiate. PMID:21127502

Quantitative description of human skin water dynamics by a disposition-decomposition analysis (DDA) of trans-epidermal water loss and epidermal capacitance.

PubMed

Rodrigues, Luis Monteiro; Pinto, Pedro Contreiras; Pereira, Luis Marcelo

2003-02-01

In vivo water assessment would greatly benefit from a dynamical approach since the evaluation of common related variables such as trans-epidermal water loss or "capacitance" measurements is always limited to instantaneous data. Mathematical modelling is still an attractive alternative already attempted with bi-exponential empirical models. A classical two-compartment interpretation of such models raises a number of questions about the underlying fundamentals, which can hardly be experimentally confirmed. However, in a system analysis sense, skin water dynamics may be approached as an ensemble of many factors, impossible to discretize, but conceptually grouped in terms of feasible properties of the system. The present paper explores the applicability of this strategy to the in vivo water dynamics assessment. From the plastic occlusion stress test (POST) skin water balance is assessed by modelling trans-epidermal water loss (TEWL) and "capacitance" data obtained at skin's surface. With system analysis (disposition-decomposition analysis) the distribution function, H(t), modelled as a sum of exponential terms, covers only the distribution characteristics of water molecules traversing the skin. This may correspond macroscopically to the experimental data accessed by "corneometry". Separately, the hyperbolic elimination function Q(TEWL) helps to characterise the dynamic aspects of water influx through the skin. In the observable range there seems to be a linear relationship between the net amount of water lost at the surface by evaporation, and the capability of the system to replenish that loss. This may be a specific characteristic of the system related to what may be described as the skin's "intrinsic hydration capacity" (IHC) a new functional parameter only identified by this strategy. These new quantitative tools are expected to find different applicabilities (from the in vivo skin characterisation to efficacy testing) contributing to disclose the dynamical nature of the skin water balance process. Copyright Blackwell Munksgaard 2003

Passive and iontophoretic transport through the skin polar pathway.

PubMed

Li, S K; Peck, K D

2013-01-01

The purpose of the present article is to briefly recount the contributions of Prof. William I. Higuchi to the area of skin transport. These contributions include developing fundamental knowledge of the barrier properties of the stratum corneum, mechanisms of skin transport, concentration gradient across skin in topical drug applications that target the viable epidermal layer, and permeation enhancement by chemical and electrical means. The complex and changeable nature of the skin barrier makes it difficult to assess and characterize the critical parameters that influence skin permeation. The systematic and mechanistic approaches taken by Dr. Higuchi in studying these parameters provided fundamental knowledge in this area and had a measured and lasting influence upon this field of study. This article specifically reviews the validation and characterization of the polar permeation pathway, the mechanistic model of skin transport, the influence of the dermis on the target skin concentration concept, and iontophoretic transport across the polar pathway of skin including the effects of electroosmosis and electropermeabilization. © 2013 S. Karger AG, Basel.

Deciphering the Complexities of Atopic Dermatitis: Shifting Paradigms in Treatment Approaches

PubMed Central

Leung, Donald Y. M.; Guttman-Yassky, Emma

2014-01-01

Atopic dermatitis (AD) is the most common chronic inflammatory skin disease. It often precedes the development of food allergy and asthma. Recent insights into AD reveal abnormalities in terminal differentiation of the epidermal epithelium leading to a defective stratum corneum, which allows enhanced allergen penetration and systemic IgE sensitization. Atopic skin is also predisposed to colonization or infection by pathogenic microbes, most notably Staphylococcus aureus and herpes simplex virus (HSV). Causes of this abnormal skin barrier are complex and driven by a combination of genetic, environmental and immunologic factors. These factors likely account for the heterogeneity of AD onset, severity and natural history of this skin disease. Recent studies suggest prevention of AD can be achieved by early interventions protecting the skin barrier. Onset of lesional AD requires effective control of local and systemic immune activation for optimal management. Early intervention may improve long term outcomes for AD and reduce the systemic allergen sensitization leading to associated allergic diseases in the gastrointestinal and respiratory tract. PMID:25282559

γδ T cells in homeostasis and host defence of epithelial barrier tissues

PubMed Central

Nielsen, Morten M.; Witherden, Deborah A.; Havran, Wendy L.

2018-01-01

Epithelial surfaces line the body and provide a critical interface between the body and the external environment which is essential to maintaining the symbiotic relationship between the host and the microbiome. Tissue-resident epithelial γδ T cells represent a major T cell population in epithelia and are ideally positioned to perform barrier surveillance and aid in tissue homeostasis and repair. In this review we focus on the intraepithelial γδ compartment in the two largest epithelial tissues in the body, namely the epidermis and intestine, and provide a comprehensive overview of the crucial contributions of intraepithelial γδ cells at these sites to tissue integrity and repair, host homeostasis and host protection in the context of the symbiotic relationship with the microbiome and during pathogen clearance. Finally, we address epithelia-specific butyrophilin-like molecules and touch upon their emerging role in selectively shaping and regulating epidermal and intestinal γδ T cell repertoires. PMID:28920588

Focused ultrasound delivery of Raman nanoparticles across the blood-brain barrier: Potential for targeting experimental brain tumors

PubMed Central

Diaz, Roberto Jose; McVeigh, Patrick Z.; O’Reilly, Meaghan A.; Burrell, Kelly; Bebenek, Matthew; Smith, Christian; Etame, Arnold; Zadeh, Gelareh; Hynynen, Kullervo; Wilson, Brian C.; Rutka, James T.

2014-01-01

Spectral mapping of nanoparticles with surface enhanced Raman scattering (SERS) capability in the near-infrared range is an emerging molecular imaging technique. We used magnetic resonance image-guided transcranial focused ultrasound (TcMRgFUS) to reversibly disrupt the blood-brain barrier (BBB) adjacent to brain tumor margins in rats. Glioma cells were found to internalize SERS capable nanoparticles of 50 nm or 120 nm physical diameter. Surface coating with anti-epidermal growth factor receptor antibody or non-specific human immunoglobulin G, resulted in enhanced cell uptake of nanoparticles in-vitro compared to nanoparticles with methyl terminated 12-unit polyethylene glycol surface. BBB disruption permitted the delivery of SERS capable spherical 50 or 120 nm gold nanoparticles to the tumor margins. Thus, nanoparticles with SERS imaging capability can be delivered across the BBB non-invasively using TcMRgFUS and have the potential to be used as optical tracking agents at the invasive front of malignant brain tumors. PMID:24374363

Sphingosine 1-Phosphate Activation of EGFR As a Novel Target for Meningitic Escherichia coli Penetration of the Blood-Brain Barrier

PubMed Central

Wang, Xiangru; Maruvada, Ravi; Morris, Andrew J.; Liu, Jun O.; Baek, Dong Jae; Kim, Kwang Sik

2016-01-01

Central nervous system (CNS) infection continues to be an important cause of mortality and morbidity, necessitating new approaches for investigating its pathogenesis, prevention and therapy. Escherichia coli is the most common Gram-negative bacillary organism causing meningitis, which develops following penetration of the blood–brain barrier (BBB). By chemical library screening, we identified epidermal growth factor receptor (EGFR) as a contributor to E. coli invasion of the BBB in vitro. Here, we obtained the direct evidence that CNS-infecting E. coli exploited sphingosine 1-phosphate (S1P) for EGFR activation in penetration of the BBB in vitro and in vivo. We found that S1P was upstream of EGFR and participated in EGFR activation through S1P receptor as well as through S1P-mediated up-regulation of EGFR-related ligand HB-EGF, and blockade of S1P function through targeting sphingosine kinase and S1P receptor inhibited EGFR activation, and also E. coli invasion of the BBB. We further found that both S1P and EGFR activations occurred in response to the same E. coli proteins (OmpA, FimH, NlpI), and that S1P and EGFR promoted E. coli invasion of the BBB by activating the downstream c-Src. These findings indicate that S1P and EGFR represent the novel host targets for meningitic E. coli penetration of the BBB, and counteracting such targets provide a novel approach for controlling E. coli meningitis in the era of increasing resistance to conventional antibiotics. PMID:27711202

Sieving characteristics of cytokine- and peroxide-induced epithelial barrier leak: Inhibition by berberine

PubMed Central

DiGuilio, Katherine M; Mercogliano, Christina M; Born, Jillian; Ferraro, Brendan; To, Julie; Mixson, Brittany; Smith, Allison; Valenzano, Mary Carmen; Mullin, James M

2016-01-01

AIM: To study whether the inflammatory bowel disease (IBD) colon which exhibits varying severity and cytokine levels across its mucosa create varying types of transepithelial leak. METHODS: We examined the effects of tumor necrosis factor-α (TNF-α), interferon-γ (IFN-γ), interleukin-1-β (IL1β) and hydrogen peroxide (H2O2) - singly and in combinations - on barrier function of CACO-2 cell layers. Our focus was on the type (not simply the magnitude) of transepithelial leak generated by these agents as measured by transepithelial electrical resistance (TER) and transepithelial flux of 14C-D-mannitol, 3H-Lactulose and 14C-Polyethylene glycol as radiolabeled probe molecules. The isoquinoline alkaloid, berberine, was then examined for its ability to reduce specific types of transepithelial leak. RESULTS: Exposure to TNF-α alone (200 ng/mL; 48 h) induced a 50% decrease in TER, i.e., increased leak of Na+ and Cl- - with only a marginal but statistically significant increase in transepithelial leak of 14C-mannitol (Jm). Exposure to TNF-α + IFN-γ (200 ng/mL; 48 h) + IL1β (50 ng/mL; 48 h) did not increase the TER change (from TNF-α alone), but there was now a 100% increase in Jm. There however was no increase in transepithelial leak of two larger probe molecules, 3H-lactulose and 14C-polyethylene glycol (PEG). However, exposure to TNF-α + IFN-γ + IL1β followed by a 5 h exposure to 2 mmol/L H2O2 resulted in a 500% increase in 14C-PEG leak as well as leak to the luminal mitogen, epidermal growth factor. CONCLUSION: This model of graded transepithelial leak is useful in evaluating therapeutic agents reducing IBD morbidity by reducing barrier leak to various luminal substances. PMID:27190695

New experimental models of skin homeostasis and diseases.

PubMed

Larcher, F; Espada, J; Díaz-Ley, B; Jaén, P; Juarranz, A; Quintanilla, M

2015-01-01

Homeostasis, whose regulation at the molecular level is still poorly understood, is intimately related to the functions of epidermal stem cells. Five research groups have been brought together to work on new in vitro and in vivo skin models through the SkinModel-CM program, under the auspices of the Spanish Autonomous Community of Madrid. This project aims to analyze the functions of DNA methyltransferase 1, endoglin, and podoplanin in epidermal stem cell activity, homeostasis, and skin cancer. These new models include 3-dimensional organotypic cultures, immunodeficient skin-humanized mice, and genetically modified mice. Another aim of the program is to use skin-humanized mice to model dermatoses such as Gorlin syndrome and xeroderma pigmentosum in order to optimize new protocols for photodynamic therapy. Copyright © 2013 Elsevier España, S.L.U. and AEDV. All rights reserved.

Whole organ, venation and epidermal cell morphological variations are correlated in the leaves of Arabidopsis mutants.

PubMed

Pérez-Pérez, José Manuel; Rubio-Díaz, Silvia; Dhondt, Stijn; Hernández-Romero, Diana; Sánchez-Soriano, Joaquín; Beemster, Gerrit T S; Ponce, María Rosa; Micol, José Luis

2011-12-01

Despite the large number of genes known to affect leaf shape or size, we still have a relatively poor understanding of how leaf morphology is established. For example, little is known about how cell division and cell expansion are controlled and coordinated within a growing leaf to eventually develop into a laminar organ of a definite size. To obtain a global perspective of the cellular basis of variations in leaf morphology at the organ, tissue and cell levels, we studied a collection of 111 non-allelic mutants with abnormally shaped and/or sized leaves, which broadly represent the mutational variations in Arabidopsis thaliana leaf morphology not associated with lethality. We used image-processing techniques on these mutants to quantify morphological parameters running the gamut from the palisade mesophyll and epidermal cells to the venation, whole leaf and rosette levels. We found positive correlations between epidermal cell size and leaf area, which is consistent with long-standing Avery's hypothesis that the epidermis drives leaf growth. In addition, venation parameters were positively correlated with leaf area, suggesting that leaf growth and vein patterning share some genetic controls. Positional cloning of the genes affected by the studied mutations will eventually establish functional links between genotypes, molecular functions, cellular parameters and leaf phenotypes. © 2011 Blackwell Publishing Ltd.

Sensory transduction and the mammalian epidermis.

PubMed

Hoath, S B; Donnelly, M M; Boissy, R E

1990-01-01

This paper constitutes, in its main intent, an introduction to the mammalian epidermis as a surface for biosensor applications. In particular, the structure and function of the epidermis of the newborn rat are examined as a model for studies of the human state. Data are presented illustrating an anisotropic organization of the dorsal surface of the neonatal rodent with regard to line of tension and thermal gradients. The dependence of the mechanical properties of the epidermis upon calcium is examined by means of an in-vitro assay of epidermal retraction. The potential role of keratin tonofilaments as piezoelectric and pyroelectric elements in the epidermis is introduced and the spatial alignment of these macromolecular arrays is demonstrated to be a function of physiological tensions. These findings are discussed in the context of noninvasive epidermal sensors utilized to understand mechanisms of sensory development and physiological regulation. Optoelectronic (infrared) imaging of the dorsal temperature field and the alteration in this field by treatment with epidermal growth factor are presented as examples of this methodologic approach. It is concluded that a detailed examination of the material and physical properties of mammalian epidermis is a reasonable goal of biosensor development and research. Hypothetically, such studies may reveal important molecular and cellular mechanisms by which sensory data are transmitted or transduced at the organism-environmental interface.

Gromwell (Lithospermum erythrorhizon) Supplementation Enhances Epidermal Levels of Ceramides, Glucosylceramides, β-Glucocerebrosidase, and Acidic Sphingomyelinase in NC/Nga Mice

PubMed Central

Kim, Jungmin; Cho, Yunhi

2013-01-01

Abstract We have previously reported that dietary gromwell (Lithospermum erythrorhizon; LE) prevents the development of atopic dermatitis (AD) with increased epidermal levels of total ceramide (Cer), the major lipid maintaining epidermal barrier. In this study, we investigated whether the increased level of total Cer induced by dietary LE would be related to the altered metabolism of glucosylceramide (GlcCer) and sphingomyelin (SM), two major precursor lipids in Cer generation. NC/Nga mice, an animal model of AD, were fed a control diet (group CA: atopic control) or a diet with 70% ethanol LE extracts (1% in diet; group LE) for 10 weeks. Individual species of Cer, GlcCer, and SM were analyzed by high-performance thin layer chromatography. In the epidermis of group CA, total Cer (including Cer2 and Cer5–7) and total GlcCer (including GlcCer-B/C/D) were significantly reduced; these levels in group LE were increased to levels similar to the normal control group of BALB/c mice (group C). In addition, protein expressions and activities of β-glucocerebrosidase (β-GlcCer'ase) and acidic sphingomyelinase (aSMase), enzymes for GlcCer or SM hydrolysis, respectively, were increased in group LE. However, alterations of Cer1, Cer3/4, GlcCer-A, and all SM species (including SM1–3) were not significant among groups C, CA, and LE. Dietary gromwell increases GlcCer-B/C/D, and further enhances the generation of Cer2 and Cer5–7 with high protein expressions and activities of β-GlcCer'ase and aSMase. PMID:24074295

Dioxygenase Activity of Epidermal Lipoxygenase-3 Unveiled

PubMed Central

Zheng, Yuxiang; Brash, Alan R.

2010-01-01

Epidermal lipoxygenase-3 (eLOX3) exhibits hydroperoxide isomerase activity implicated in epidermal barrier formation, but its potential dioxygenase activity has remained elusive. We identified herein a synthetic fatty acid, 9E,11Z,14Z-20:3ω6, that was oxygenated by eLOX3 specifically to the 9S-hydroperoxide. Reaction showed a pronounced lag phase, which suggested that eLOX3 is deficient in its activation step. Indeed, we found that high concentrations of hydroperoxide activator (e.g. 65 μm) overcame a prolonged lag phase (>1 h) and unveiled a dioxygenase activity with arachidonic acid; the main products were the 5-, 9-, and 7-hydroperoxyeicosatetraenoic acids (HPETEs). These were R/S mixtures (ranging from ∼50:50 to 73:27), and as the bis-allylic 7-HPETE can be formed only inside the enzyme active site, the results indicate there is oxygen availability along either face of the reacting fatty acid radical. That the active site oxygen supply is limited is implied from the need for continuous re-activation, as carbon radical leakage leaves the enzyme in the unactivated ferrous state. An Ala-to-Gly mutation, known to affect the positioning of O2 in the active site of other lipoxygenase enzymes, led to more readily activated reaction and a significant increase in the 9R- over the 5-HPETE. Activation and cycling of the ferric enzyme are thus promoted using the 9E,11Z,14Z-20:3ω6 substrate, by continuous hydroperoxide activation, or by the Ala-to-Gly mutation. We suggest that eLOX3 represents one end of a spectrum among lipoxygenases where activation is inefficient, favoring hydroperoxide isomerase cycling, with the opposite end represented by readily activated enzymes in which dioxygenase activity is prominent. PMID:20921226

Role of Epidermal Growth Factor Receptor (EGFR) Inhibitors and Radiation in the Management of Brain Metastases from EGFR Mutant Lung Cancers.

PubMed

Khandekar, Melin J; Piotrowska, Zofia; Willers, Henning; Sequist, Lecia V

2018-04-27

The growth of genotype-directed targeted therapies, such as inhibitors of the epidermal growth factor receptor (EGFR), has revolutionized treatment for some patients with oncogene-addicted lung cancer. However, as systemic control for these patients has improved, brain metastases remain an important source of morbidity and mortality. Traditional treatment for brain metastases has been radiotherapy, either whole-brain radiation or stereotactic radiosurgery. The growing availability of drugs that can cross the blood-brain barrier and have activity in the central nervous system (CNS) has led to many studies investigating whether targeted therapy can be used in combination with or in lieu of radiation. In this review, we summarize the key literature about the incidence and nature of EGFR-mutant brain metastases (EGFR BMs), the data about the activity of EGFR inhibitors in the CNS, and whether they can be used as front-line therapy for brain metastases. Although initial use of tyrosine kinase inhibitors for EGFR BMs can often be an effective treatment strategy, multidisciplinary evaluation is critical, and prospective studies are needed to clarify which patients may benefit from early radiotherapy. Management of brain metastases in epidermal growth factor receptor (EGFR) mutant lung cancer is a common clinical problem. The question of whether to start initial therapy with an EGFR inhibitor or radiotherapy (either whole-brain radiotherapy or stereotactic radiosurgery) is controversial. The development of novel EGFR inhibitors with enhanced central nervous system (CNS) penetration is an important advance in the treatment of CNS disease. Multidisciplinary evaluation and evaluation of extracranial disease status are critical to choosing the best treatment option for each patient. © AlphaMed Press 2018.

Eccrine Sweat Contains IL-1α, IL-1β and IL-31 and Activates Epidermal Keratinocytes as a Danger Signal

PubMed Central

Dai, Xiuju; Okazaki, Hidenori; Hanakawa, Yasushi; Murakami, Masamoto; Tohyama, Mikiko; Shirakata, Yuji; Sayama, Koji

2013-01-01

Eccrine sweat is secreted onto the skin's surface and is not harmful to normal skin, but can exacerbate eczematous lesions in atopic dermatitis. Although eccrine sweat contains a number of minerals, proteins, and proteolytic enzymes, how it causes skin inflammation is not clear. We hypothesized that it stimulates keratinocytes directly, as a danger signal. Eccrine sweat was collected from the arms of healthy volunteers after exercise, and levels of proinflammatory cytokines in the sweat were quantified by ELISA. We detected the presence of IL-1α, IL-1β, and high levels of IL-31 in sweat samples. To investigate whether sweat activates keratinocytes, normal human keratinocytes were stimulated with concentrated sweat. Western blot analysis demonstrated the activation of NF-κB, ERK, and JNK signaling in sweat-stimulated keratinocytes. Real-time PCR using total RNA and ELISA analysis of supernatants showed the upregulation of IL-8 and IL-1β by sweat. Furthermore, pretreatment with IL-1R antagonist blocked sweat-stimulated cytokine production and signal activation, indicating that bioactive IL-1 is a major factor in the activation of keratinocytes by sweat. Moreover, IL-31 seems to be another sweat stimulator that activates keratinocytes to produce inflammatory cytokine, CCL2. Sweat is secreted onto the skin's surface and does not come into contact with keratinocytes in normal skin. However, in skin with a defective cutaneous barrier, such as atopic dermatitis-affected skin, sweat cytokines can directly act on epidermal keratinocytes, resulting in their activation. In conclusion, eccrine sweat contains proinflammatory cytokines, IL-1 and IL-31, and activates epidermal keratinocytes as a danger signal. PMID:23874436

Characterization of glycosylphosphatidylinositol-anchored lipid transfer protein 2 (LTPG2) and overlapping function between LTPG/LTPG1 and LTPG2 in cuticular wax export or accumulation in Arabidopsis thaliana.

PubMed

Kim, Hyojin; Lee, Saet Buyl; Kim, Hae Jin; Min, Myung Ki; Hwang, Inhwan; Suh, Mi Chung

2012-08-01

Cuticular waxes are synthesized by the extensive export of intracellular lipids from epidermal cells. However, it is still not known how hydrophobic cuticular lipids are exported to the plant surface through the hydrophilic cell wall. The LTPG2 gene was isolated based on Arabidopsis microarray analysis; this gene is predominantly expressed in stem epidermal peels as compared with in stems. The expression of LTPG2 transcripts was observed in various organs, including stem epidermis and silique walls. The composition of the cuticular wax was significantly altered in the stems and siliques of the ltpg2 mutant and ltpg1 ltpg2 double mutant. In particular, the reduced level of the C29 alkane, which is the major component of cuticular waxes in ltpg1 ltpg2 stems and siliques, was similar to the sum of reduced values of either parent. The total cuticular wax load was reduced by approximately 13% and 20% in both ltpg2 and ltpg1 ltpg2 siliques, respectively, and by approximately 14% in ltpg1 ltpg2 stems when compared with the wild-type. Similarly, severe alterations in the cuticular layer structure of epidermal cells of ltpg2 and ltpg1 ltpg2 stems and silique walls were observed. In tobacco epidermal cells, intracellular trafficking of the fluorescent LTPG/LTPG1 and LTPG2 to the plasma membrane was prevented by a dominant-negative mutant form of ADP-ribosylation factor 1, ARF1(T31N). Taken together, these results indicate that LTPG2 is functionally overlapped with LTPG/LTPG1 during cuticular wax export or accumulation and LTPG/LTPG1 and LTPG2 are targeted to the plasma membrane via the vesicular trafficking system.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jin, Sun Hee; Choi, Dalwoong; Chun, Young-Jin

Keratinocytes are the major cellular components of human epidermis and play a key role in the modulating cutaneous inflammation and toxic responses. In human chronic skin diseases, the common skin inflammatory phenotypes like skin barrier disruption and epidermal hyperplasia are manifested in epidermal keratinocytes by interactions with T helper (Th) cells. To find a common gene expression signature of human keratinocytes in chronic skin diseases, we performed a whole genome microarray analysis on normal human epidermal keratinocytes (NHKs) treated with IFNγ, IL-4, IL-17A or IL-22, major cytokines from Th1, Th2, Th17 or Th22 cells, respectively. The microarray results showed thatmore » the four genes, IL-24, PDZK1IP1, H19 and filaggrin, had common expression profiles in NHKs exposed to Th cell cytokines. In addition, the acute phase pro-inflammatory cytokines, IL-1β, IL-6 and TNFα, also change the gene transcriptional profile of IL-24, PDZK1IP1, H19, and filaggrin in NHKs as those of Th cytokines. Therefore, the signature gene set, consisting of IL-24, PDZK1IP1, H19, and filaggrin, provides essential insights for understanding the process of cutaneous inflammation and toxic responses. We demonstrate that environmental toxic stressors, such as chemical irritants and ultraviolet irradiation stimulate the production of IL-24 in NHKs. IL-24 stimulates the JAK1-STAT3 and MAPK pathways in NHKs, and promotes the secretion of pro-inflammatory mediators IL-8, PGE2, and MMP-1. These results suggest that keratinocyte-derived IL-24 participates in the positive feedback regulation of epidermal inflammation in response to both endogenous and environmental toxic stressors. - Highlights: • Cutaneous inflammatory gene signature consists of PDZK1IP1, IL-24, H19 and filaggrin. • Pro-inflammatory cytokines increase IL-24 production in human keratinocytes. • Environmental toxic stressors increase IL-24 production in human keratinocytes. • IL-24 stimulates human keratinocytes to produce pro-inflammatory mediators. • IL-24 activates STAT3 and MAPK signaling pathways in human keratinocytes.« less

Effects of Human Mesenchymal Stem Cells Coculture on Calcium-Induced Differentiation of Normal Human Keratinocytes.

PubMed

Sah, Shyam Kishor; Kim, Hae Young; Lee, Ji Hae; Lee, Seong-Wook; Kim, Hyung-Sik; Kim, Yeon-Soo; Kang, Kyung-Sun; Kim, Tae-Yoon

2017-06-01

The influence of mesenchymal stem cells (MSCs) on keratinocytes in altered microenvironments is poorly understood. Here, we cocultured umbilical cord blood-derived MSCs with normal human epidermal keratinocytes to evaluate their paracrine effect in the presence of high extracellular calcium (Ca 2+ ) concentration. High Ca 2+ environment to keratinocytes can disrupt normal skin barrier function due to abnormal/premature differentiation of keratinocytes. Surprisingly, we found that MSCs suppress both proliferation and differentiation of keratinocytes under a high Ca 2+ environment in transforming growth factors β1 (TGFβ1)-dependent manner. Furthermore, we determined that MSCs can regulate the mitogen-activated protein kinases, phosphatidylinositol 3-kinase/protein kinase B, and protein kinase C pathways in Ca 2+ -induced differentiated keratinocytes. Knockdown of TGFβ1 from MSCs results in decreased suppression of differentiation with significantly increased proliferation of keratinocytes compared with control MSCs. MSCs-derived TGFβ1 further induced growth inhibition of keratinocyte in high extracellular Ca 2+ environment as analyzed by a decrease in DNA synthesis, accumulation of phosphorylated retinoblastoma protein, cdc2, and increased mRNA level of p21, and independent of TGFβ1/SMAD pathway. Taken together, we found that MSCs-derived TGFβ1 is a critical regulator of keratinocyte function, and involves multiple proximal signaling cascades. Stem Cells 2017;35:1592-1602. © 2017 AlphaMed Press.

The Effect of Bone Marrow-Derived Mesenchymal Stem Cells and Their Conditioned Media Topically Delivered in Fibrin Glue on Chronic Wound Healing in Rats

PubMed Central

Mehanna, Radwa A.; Nabil, Iman; Attia, Noha; Bary, Amany A.; Razek, Khalid A.; Ahmed, Tamer A. E.; Elsayed, Fatma

2015-01-01

Bone marrow-derived mesenchymal stem cells (BM-MSCs) represent a modern approach for management of chronic skin injuries. In this work, we describe BM-MSCs application versus their conditioned media (CM) when delivered topically admixed with fibrin glue to enhance the healing of chronic excisional wounds in rats. Fifty-two adult male rats were classified into four groups after induction of large-sized full-thickness skin wound: control group (CG), fibrin only group (FG), fibrin + MSCs group (FG + SCs), and fibrin + CM group (FG + CM). Healing wounds were evaluated functionally and microscopically. Eight days after injury, number of CD68+ macrophages infiltrating granulation tissue was considerably higher in the latter two groups. Although—later—none of the groups depicted a substantially different healing rate, the quality of regenerated skin was significantly boosted by the application of either BM-MSCs or their CM both (1) structurally as demonstrated by the obviously increased mean area percent of collagen fibers in Masson's trichrome-stained skin biopsies and (2) functionally as supported by the interestingly improved epidermal barrier as well as dermal tensile strength. Thus, we conclude that topically applied BM-MSCs and their CM—via fibrin vehicle—could effectively improve the quality of healed skin in chronic excisional wounds in rats, albeit without true acceleration of wound closure. PMID:26236740

Various members of the Toll-like receptor family contribute to the innate immune response of human epidermal keratinocytes

PubMed Central

Köllisch, Gabriele; Kalali, Behnam Naderi; Voelcker, Verena; Wallich, Reinhard; Behrendt, Heidrun; Ring, Johannes; Bauer, Stefan; Jakob, Thilo; Mempel, Martin; Ollert, Markus

2005-01-01

Toll-like receptors (TLRs) are important pattern recognition molecules that activate the nuclear factor (NF)-κB pathway leading to the production of antimicrobial immune mediators. As keratinocytes represent the first barrier against exogenous pathogens in human skin, we investigated their complete functional TLR1–10 expression profile. First, reverse transcription–polymerase chain reaction (PCR) analysis revealed a very similar pattern of TLR mRNA expression when comparing freshly isolated human epidermis and cultured primary human keratinocytes. Thus, further experiments were carried out with primary keratinocytes in comparison with the spontaneously immortalized human keratinocyte cell line HaCaT. The quantitative expression of TLR1–10 mRNA in real-time PCR of primary human keratinocytes and HaCaT cells was analysed. Both cell types constitutively expressed TLR2, TLR3, TLR5, and to a lesser extent TLR10. TLR4 was only found in HaCaT cells, TLR1 to a higher degree in primary keratinocytes. In line with this, LPS induced mRNA expression of CD14 and TLR4 only in HaCaT cells. After stimulation with various TLR ligands, the NF-κB-activated chemokine interleukin-8 (IL-8) was measured. In primary keratinocytes and HaCaT cells the TLR3 ligand poly (I:C) was the most potent stimulator of IL-8 secretion. The TLR ligands peptidoglycan, Pam3Cys and flagellin which bind to TLR2, TLR1/TLR2 heterodimer, and TLR5, respectively, also induced IL-8 secretion, whereas no IL-8 was induced by LPS, R-848, loxoribine and cytosine guanine dinucleotide-containing oligodeoxynucleotide. A corresponding pattern was found in the RelA NF-κB translocation assay after ligand stimulation of primary keratinocytes. These studies provide substantial evidence for a functional TLR expression and signalling profile of normal human keratinocytes contributing to the antimicrobial defence barrier of human skin. PMID:15804290

Environmental NO2 and CO Exposure: Ignored Factors Associated with Uremic Pruritus in Patients Undergoing Hemodialysis

NASA Astrophysics Data System (ADS)

Huang, Wen-Hung; Lin, Jui-Hsiang; Weng, Cheng-Hao; Hsu, Ching-Wei; Yen, Tzung-Hai

2016-08-01

Uremic pruritus (UP), also known as chronic kidney disease-associated pruritus, is a common and disabling symptom in patients undergoing maintenance hemodialysis (MHD). The pathogenesis of UP is multifactorial and poorly understood. Outdoor air pollution has well-known effects on the health of patients with allergic diseases through an inflammatory process. Air pollution-induced inflammation could occur in the skin and aggravate skin symptoms such as pruritus or impair epidermal barrier function. To assess the role of air pollutants, and other clinical variables on uremic pruritus (UP) in HD patients, we recruited 866 patients on maintenance HD. We analyzed the following variables for association with UP: average previous 12-month and 24-month background concentrations for nitrogen dioxide (NO2) and carbon monoxide (CO), and suspended particulate matter of <2.5 μm (PM2.5). In a multivariate logistic regression, hemodialysis duration, serum ferritin levels, low-density lipoprotein levels, and environmental NO2/CO levels were positively associated with UP, and serum albumin levels were negatively associated with UP. This cross-sectional study showed that air pollutants such as NO2 and CO might be associated with UP in patients with MHD.

Photoacoustic study of the penetration kinetics of nimesulid into human skin

NASA Astrophysics Data System (ADS)

Barja, P. R.; Veloso, D. J. D. V.

2010-03-01

The photoacoustic (PA) effect is observed when modulated (or pulsed) light is absorbed by a sample inside a closed chamber and converted in heat, generating acoustic waves; PA measurements have been employed to evaluate transdermal penetration of topically applied drugs. Phonophoresis is the utilization of ultrasonic (US) energy to enhance absorption of drugs across the epidermal barrier, and its usefulness has been shown by PA measurements. The aim of the present work was to determine the characteristic absorption times of the anti-inflammatory Nimesulid (gel) in human skin, with and without help of therapeutic phonophoresis. After local cleaning, measurements were performed in the forearm of each volunteer before Nimesulid application and for different times after application through massage with the US equipment head; the protocol was repeated for the opposite forearm, but without US emission. Curves of the PA signal level as a function of time were adjusted by a Boltzmann equation, leading to the determination of the characteristic absorption time (about 12 minutes). No significant gain was observed in Nimesulid absorption with the utilization of US radiation, indicating that topic application of Nimesulid does not require the use of phonophoresis, due to the natural fast penetration of the Nimesulid gel.

Claudins 1, 2, 3, 4, 5 and 7 in solar keratosis and squamocellular carcinoma of the skin

PubMed Central

Hintsala, Hanna-Riikka; Siponen, Maria; Haapasaari, Kirsi-Maria; Karihtala, Peeter; Soini, Ylermi

2013-01-01

Claudins are tight junction proteins regulating the paracellular permeability of cell layers. We investigated the expression of claudins 1, 2, 3, 4, 5 and 7 in a sample set consisting of a total of 93 cases representing normal skin, actinic keratoses and squamous cell carcinomas of the skin. There were several changes found in claudin expression. Claudin 1 appeared to be progressively decreased in solar keratosis and skin squamous cell carcinomas compared to normal skin while expression of claudin 2 was increased. With claudins 3 and 5 occasional immunoreactivity was found in squamous cell carcinomas. Claudins 4 and 7 were variably expressed in skin neoplasia compared to normal skin. According to the results expression of claudins 1 and 2 change in parallel with the severity of the epidermal preneoplastic and neoplastic lesions thus probably influencing the disturbed epithelial polarity characteristic of these lesions. Claudin 1 under- and claudin 2 overexpression also lead to a leakier epithelial barrier function of the skin with a resulting damage to skin epithelial resistance. Other claudins investigated in this study did not show progressive changes even though occasional overexpression of them was found in skin squamous cell carcinoma. PMID:24294371

A first vascularized skin equivalent as an alternative to animal experimentation.

PubMed

Groeber, Florian; Engelhardt, Lisa; Lange, Julia; Kurdyn, Szymon; Schmid, Freia F; Rücker, Christoph; Mielke, Stephan; Walles, Heike; Hansmann, Jan

2016-01-01

Tissue-engineered skin equivalents mimic key aspects of the human skin, and can thus be employed as wound coverage for large skin defects or as in vitro test systems as an alternative to animal models. However, current skin equivalents lack a functional vasculature limiting clinical and research applications. This study demonstrates the generation of a vascularized skin equivalent with a perfused vascular network by combining a biological vascularized scaffold (BioVaSc) based on a decellularized segment of a porcine jejunum and a tailored bioreactor system. Briefly, the BioVaSc was seeded with human fibroblasts, keratinocytes, and human microvascular endothelial cells. After 14 days at the air-liquid interface, hematoxylin & eosin and immunohistological staining revealed a specific histological architecture representative of the human dermis and epidermis including a papillary-like architecture at the dermal-epidermal-junction. The formation of the skin barrier was measured non-destructively using impedance spectroscopy. Additionally, endothelial cells lined the walls of the formed vessels that could be perfused with a physiological volume flow. Due to the presence of a complex in-vivo-like vasculature, the here shown skin equivalent has the potential for skin grafting and represents a sophisticated in vitro model for dermatological research.

Oxidative Stress in Aging Human Skin

PubMed Central

Rinnerthaler, Mark; Bischof, Johannes; Streubel, Maria Karolin; Trost, Andrea; Richter, Klaus

2015-01-01

Oxidative stress in skin plays a major role in the aging process. This is true for intrinsic aging and even more for extrinsic aging. Although the results are quite different in dermis and epidermis, extrinsic aging is driven to a large extent by oxidative stress caused by UV irradiation. In this review the overall effects of oxidative stress are discussed as well as the sources of ROS including the mitochondrial ETC, peroxisomal and ER localized proteins, the Fenton reaction, and such enzymes as cyclooxygenases, lipoxygenases, xanthine oxidases, and NADPH oxidases. Furthermore, the defense mechanisms against oxidative stress ranging from enzymes like superoxide dismutases, catalases, peroxiredoxins, and GSH peroxidases to organic compounds such as L-ascorbate, α-tocopherol, beta-carotene, uric acid, CoQ10, and glutathione are described in more detail. In addition the oxidative stress induced modifications caused to proteins, lipids and DNA are discussed. Finally age-related changes of the skin are also a topic of this review. They include a disruption of the epidermal calcium gradient in old skin with an accompanying change in the composition of the cornified envelope. This modified cornified envelope also leads to an altered anti-oxidative capacity and a reduced barrier function of the epidermis. PMID:25906193

BP180 dysfunction triggers spontaneous skin inflammation in mice.

PubMed

Zhang, Yang; Hwang, Bin-Jin; Liu, Zhen; Li, Ning; Lough, Kendall; Williams, Scott E; Chen, Jinbo; Burette, Susan W; Diaz, Luis A; Su, Maureen A; Xiao, Shengxiang; Liu, Zhi

2018-06-04

BP180, also known as collagen XVII, is a hemidesmosomal component and plays a key role in maintaining skin dermal/epidermal adhesion. Dysfunction of BP180, either through genetic mutations in junctional epidermolysis bullosa (JEB) or autoantibody insult in bullous pemphigoid (BP), leads to subepidermal blistering accompanied by skin inflammation. However, whether BP180 is involved in skin inflammation remains unknown. To address this question, we generated a BP180-dysfunctional mouse strain and found that mice lacking functional BP180 (termed Δ NC16A ) developed spontaneous skin inflammatory disease, characterized by severe itch, defective skin barrier, infiltrating immune cells, elevated serum IgE levels, and increased expression of thymic stromal lymphopoietin (TSLP). Severe itch is independent of adaptive immunity and histamine, but dependent on increased expression of TSLP by keratinocytes. In addition, a high TSLP expression is detected in BP patients. Our data provide direct evidence showing that BP180 regulates skin inflammation independently of adaptive immunity, and BP180 dysfunction leads to a TSLP-mediated itch. The newly developed mouse strain could be a model for elucidation of disease mechanisms and development of novel therapeutic strategies for skin inflammation and BP180-related skin conditions.

The mysterious human epidermal cell cycle, or an oncogene-induced differentiation checkpoint

PubMed Central

Gandarillas, Alberto

2012-01-01

Fifteen years ago, we reported that proto-oncogene MYC promoted differentiation of human epidermal stem cells, a finding that was surprising to the MYC and the skin research communities. MYC was one of the first human oncogenes identified, and it had been strongly associated with proliferation. However, it was later shown that MYC could induce apoptosis under low survival conditions. Currently, the notion that MYC promotes epidermal differentiation is widely accepted, but the cell cycle mechanisms that elicit this function remain unresolved. We have recently reported that keratinocytes respond to cell cycle deregulation and DNA damage by triggering terminal differentiation. This mechanism might constitute a homeostatic protection face to cell cycle insults. Here, I discuss recent and not-so-recent evidence suggesting the existence of a largely unexplored oncogene-induced differentiation response (OID) analogous to oncogene-induced apoptosis (OIA) or senescence (OIS). In addition, I propose a model for the role of the cell cycle in skin homeostasis maintenance and for the dual role of MYC in differentiation. PMID:23114621

Conformational stability of the epidermal growth factor (EGF) receptor as influenced by glycosylation, dimerization and EGF hormone binding.

PubMed

Taylor, Eric S; Pol-Fachin, Laercio; Lins, Roberto D; Lower, Steven K

2017-04-01

The epidermal growth factor receptor (EGFR) is an important transmembrane glycoprotein kinase involved the initiation or perpetuation of signal transduction cascades within cells. These processes occur after EGFR binds to a ligand [epidermal growth factor (EGF)], thus inducing its dimerization and tyrosine autophosphorylation. Previous publications have highlighted the importance of glycosylation and dimerization for promoting proper function of the receptor and conformation in membranes; however, the effects of these associations on the protein conformational stability have not yet been described. Molecular dynamics simulations were performed to characterize the conformational preferences of the monomeric and dimeric forms of the EGFR extracellular domain upon binding to EGF in the presence and absence of N-glycan moieties. Structural stability analyses revealed that EGF provides the most conformational stability to EGFR, followed by glycosylation and dimerization, respectively. The findings also support that EGF-EGFR binding takes place through a large-scale induced-fitting mechanism. Proteins 2017; 85:561-570. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Generation of Genetically Modified Organotypic Skin Cultures Using Devitalized Human Dermis.

PubMed

Li, Jingting; Sen, George L

2015-12-14

Organotypic cultures allow the reconstitution of a 3D environment critical for cell-cell contact and cell-matrix interactions which mimics the function and physiology of their in vivo tissue counterparts. This is exemplified by organotypic skin cultures which faithfully recapitulates the epidermal differentiation and stratification program. Primary human epidermal keratinocytes are genetically manipulable through retroviruses where genes can be easily overexpressed or knocked down. These genetically modified keratinocytes can then be used to regenerate human epidermis in organotypic skin cultures providing a powerful model to study genetic pathways impacting epidermal growth, differentiation, and disease progression. The protocols presented here describe methods to prepare devitalized human dermis as well as to genetically manipulate primary human keratinocytes in order to generate organotypic skin cultures. Regenerated human skin can be used in downstream applications such as gene expression profiling, immunostaining, and chromatin immunoprecipitations followed by high throughput sequencing. Thus, generation of these genetically modified organotypic skin cultures will allow the determination of genes that are critical for maintaining skin homeostasis.

CER4 Encodes an Alcohol-Forming Fatty Acyl-Coenzyme A Reductase Involved in Cuticular Wax Production in Arabidopsis1[W

PubMed Central

Rowland, Owen; Zheng, Huanquan; Hepworth, Shelley R.; Lam, Patricia; Jetter, Reinhard; Kunst, Ljerka

2006-01-01

A waxy cuticle that serves as a protective barrier against uncontrolled water loss and environmental damage coats the aerial surfaces of land plants. It is composed of a cutin polymer matrix and waxes. Cuticular waxes are complex mixtures of very-long-chain fatty acids and their derivatives. We report here the molecular cloning and characterization of CER4, a wax biosynthetic gene from Arabidopsis (Arabidopsis thaliana). Arabidopsis cer4 mutants exhibit major decreases in stem primary alcohols and wax esters, and slightly elevated levels of aldehydes, alkanes, secondary alcohols, and ketones. This phenotype suggested that CER4 encoded an alcohol-forming fatty acyl-coenzyme A reductase (FAR). We identified eight FAR-like genes in Arabidopsis that are highly related to an alcohol-forming FAR expressed in seeds of jojoba (Simmondsia chinensis). Molecular characterization of CER4 alleles and genomic complementation revealed that one of these eight genes, At4g33790, encoded the FAR required for cuticular wax production. Expression of CER4 cDNA in yeast (Saccharomyces cerevisiae) resulted in the accumulation of C24:0 and C26:0 primary alcohols. Fully functional green fluorescent protein-tagged CER4 protein was localized to the endoplasmic reticulum in yeast cells by confocal microscopy. Analysis of gene expression by reverse transcription-PCR indicated that CER4 was expressed in leaves, stems, flowers, siliques, and roots. Expression of a β-glucuronidase reporter gene driven by the CER4 promoter in transgenic plants was detected in epidermal cells of leaves and stems, consistent with a dedicated role for CER4 in cuticular wax biosynthesis. CER4 was also expressed in all cell types in the elongation zone of young roots. These data indicate that CER4 is an alcohol-forming FAR that has specificity for very-long-chain fatty acids and is responsible for the synthesis of primary alcohols in the epidermal cells of aerial tissues and in roots. PMID:16980563

Calcitonin gene-related peptide cooperates with substance P to inhibit melanogenesis and induces apoptosis of B16F10 cells.

PubMed

Zhou, Jia; Feng, Jun-Yi; Wang, Qian; Shang, Jing

2015-07-01

Skin is the largest organ in human body and works as biologically active barrier to provide critical preservation of body homeostasis. The skin is highly innervated by a plenitude of nerve fiber subpopulations, each carrying one or more neuronal mediators. Melanocyte itself also intimately contact with nerve fibers to form 'synaptic-like structure' and its functions may be directly regulated by the mediators contained in terminals of intra-epidermal nerve fibers. Clinical and biochemical studies have suggested that calcitonin gene-related peptide (CGRP) is involved in vitiligo skin. The present study was designed to investigate the effect of CGRP on epidermal melanocytes. After treatment with CGRP ranging from 0 to 500 ng/mL for 48 h, tyrosinase activity and melanogenesis were with little changes compared to treatment with medium only in B16F10 cells. Treatment with 500 ng/mL of CGRP cooperates with substance P (SP) (0.1-10 nM) to decrease tyrosinase activity and decrease melanin biosynthesis in B16F10 cells in a concentration-dependent manner. Furthermore, CGRP (8-37) antagonizes the synergistic effect of CGRP. The effect of CGRP on the cell apoptosis was examined. Treatments with 0-500 ng/mL of CGRP for 24 h, the expression levels of cleaved caspase-3, total caspase-3, cleaved caspase-9 and total caspase-9 were increased in a concentration-dependent manner. And 500 ng/mL of CGRP induced B16F10 cell apoptosis showed by TUNEL assay. In addition, Bax expression was up-regulated and Bcl-2 down-regulated in response to CGRP treatment. Hence, the Bax/Bcl-2 ratio was significantly increased. These in vitro observations indicate the pro-apoptotic impact of CGRP on B16F10 cell. Copyright © 2015 Elsevier Ltd. All rights reserved.

[Current Topics on Vitamin D. The vitamin D functions in keratinocytes and its therapeutic applications].

PubMed

Sawatsubashi, Shun

2015-03-01

1,25 (OH) 2D and calcium have been shown to promote epidermal keratinocyte differentiation and prevent proliferation. These prodifferentiation and antiproliferative effects of 1,25 (OH) 2D have led to its clinical use in the treatment of psoriasis. However, the mechanism of vitamin D action on keratinocytes remains largely unknown. While the actions of calcium and the vitamin D receptor signaling pathways on epidermal keratinocyte differentiation are redundant, their effects on the hair follicle are not. In this review, we discuss how the vitamin D and its receptor contribute to skin and hair follicle homeostasis.

Actin dynamics regulate immediate PAR-2-dependent responses to acute epidermal permeability barrier abrogation.

PubMed

Roelandt, Truus; Heughebaert, Carol; Verween, Gunther; Giddelo, Christina; Verbeken, Gilbert; Pirnay, Jean-Paul; Devos, Daniel; Crumrine, Debra; Roseeuw, Diane; Elias, Peter M; Hachem, Jean-Pierre

2011-02-01

Lamellar body (LB) secretion and terminal differentiation of stratum granulosum (SG) cells are signaled by both protease activated receptor-2 (PAR-2) and caveolin-1 (cav-1). To address the early dynamics of LB secretion, we examined cytoskeletal remodeling of keratinocytes in 3 mouse models following acute barrier abrogation: hairless mice, PAR-2 knockout (-/-) and cav-1 -/-. Under basal conditions, globular (G)-actin accumulates in SG cells cytosol, while filamentous (F)-actin is restricted to peri-membrane domains. Barrier abrogation induces the apical movement of F-actin and the retreat of the SG-G-actin front, paralleled by upstream cytoskeletal kinases activation. This phenomenon was both enhanced by PAR-2 agonist, and inhibited by cytochalasin-D and in PAR-2 knockout mice. We found that plasma membrane conformational changes causing LB secretion are controlled by PAR-2-dependent cytoskeletal rearrangements. We next addressed the interaction dynamics between cytoskeleton and plasma membrane following PAR-2-induced actin stress fiber formation in both cav-1 -/- and wildtype cells. Actin stress fiber formation is increased in cav-1 -/- cells prior to and following PAR-2 agonist peptide-treatment, while absence of cav-1 inhibits E-cadherin-mediated cell-to-cell adhesion. PAR-2 drives cytoskeletal/plasma membrane dynamics that regulate early LB secretion following barrier abrogation, stress fiber formation and keratinocyte adhesion. Copyright © 2010 Japanese Society for Investigative Dermatology. Published by Elsevier Ireland Ltd. All rights reserved.

Effect of skin barrier disruption on immune responses to topically applied cross-reacting material, CRM(197), of diphtheria toxin.

PubMed

Godefroy, S; Peyre, M; Garcia, N; Muller, S; Sesardic, D; Partidos, C D

2005-08-01

The high accessibility of the skin and the presence of immunocompetent cells in the epidermis makes this surface an attractive route for needle-free administration of vaccines. However, the lining of the skin by the stratum corneum is a major obstacle to vaccine delivery. In this study we examined the effect of skin barrier disruption on the immune responses to the cross-reacting material CRM(197), a nontoxic mutant of diphtheria toxin (DTx) that is considered as a vaccine candidate. Application of CRM(197), together with cholera toxin (CT), onto the tape-stripped skin of mice elicited antibody responses that had anti-DTx neutralizing activity. Vaccine delivery onto mildly ablated skin or intact skin did not elicit any detectable anti-CRM(197) antibodies. Mice immunized with CRM(197) alone onto the tape-stripped skin mounted a vigorous antigen-specific proliferative response. In contrast, the induction of cellular immunity after CRM(197) deposition onto mildly ablated or intact skin was adjuvant dependent. Furthermore, epidermal cells were activated and underwent apoptosis that was more pronounced when the stratum corneum was removed by tape stripping. Overall, these findings highlight the potential for transcutaneous delivery of CRM(197) and establish a correlation between the degree of barrier disruption and levels of antigen-specific immune responses. Moreover, these results provide the first evidence that the development of a transcutaneous immunization strategy for diphtheria, based on simple and practical methods to disrupt the skin barrier, is feasible.

Redox-dependent regulation of epidermal growth factor receptor signaling.

PubMed

Heppner, David E; van der Vliet, Albert

2016-08-01

Tyrosine phosphorylation-dependent cell signaling represents a unique feature of multicellular organisms, and is important in regulation of cell differentiation and specialized cell functions. Multicellular organisms also contain a diverse family of NADPH oxidases (NOXs) that have been closely linked with tyrosine kinase-based cell signaling and regulate tyrosine phosphorylation via reversible oxidation of cysteine residues that are highly conserved within many proteins involved in this signaling pathway. An example of redox-regulated tyrosine kinase signaling involves the epidermal growth factor receptor (EGFR), a widely studied receptor system with diverse functions in normal cell biology as well as pathologies associated with oxidative stress such as cancer. The purpose of this Graphical Redox Review is to highlight recently emerged concepts with respect to NOX-dependent regulation of this important signaling pathway. Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.

Silver-loaded seaweed-based cellulosic fiber improves epidermal skin physiology in atopic dermatitis: safety assessment, mode of action and controlled, randomized single-blinded exploratory in vivo study.

PubMed

Fluhr, Joachim W; Breternitz, Maria; Kowatzki, Doreen; Bauer, Andrea; Bossert, Joerg; Elsner, Peter; Hipler, Uta-Christina

2010-08-01

The epidermal part of the skin is the major interface between the internal body and the external environment. The skin has a specific physiology and is to different degrees adapted for protection against multiple exogenous stress factors. Clothing is the material with the longest and most intensive contact to human skin. It plays a critical role especially in inflammatory dermatoses or skin conditions with an increased susceptibility of bacterial and fungal infections like atopic dermatitis. Previously, we have shown a dose-dependent antibacterial and antifungal activity of silver-loaded seaweed-based cellulosic fibres. We studied the mode of action of silver-loaded seaweed-based cellulosic fiber and performed a broad safety assessment. The principal aim was to analyse the effects of wearing the textile on epidermal skin physiology in 37 patients with atopic dermatitis in a controlled, randomized single-blinded in vivo study. Furthermore, the sensitization potential was tested in a patch test in 111 panellists. We could demonstrate in vitro a dose-dependent scavenging of induced reactive oxygen species by silver-loaded seaweed-based cellulosic fibers. Safety assessment of these fibres showed no detectable release of silver ions. Furthermore, ex vivo assessment after 24 h application both in healthy volunteers and patients with atopic dermatitis by sequential tape stripping and subsequently raster electron microscopy and energy dispersive microanalysis analysis revealed no detectable amounts of silver in any of stratum corneum layers. Serum analysis of silver showed no detectable levels. The in vivo patch testing of 111 volunteers revealed no sensitization against different SeaCell Active (SeaCell GmbH, Rudolstadt, Germany) containing fabrics. The in vivo study on 37 patients with known atopic dermatitis and mild-to-moderate eczema on their arms were randomly assigned to either silver-loaded seaweed fibre T-shirts or to cotton T-shirts for 8 weeks. A significant reduction in Staphylococcus aureus colonization was detectable for the silver T-shirts compared with cotton T-shirts without any changes in non-pathogenic surface bacteria colonization. Furthermore, a more pronounced improvement in barrier function (transepidermal water loss) was observed in mildly involved eczema areas during the first 4 weeks of the study. Stratum corneum hydration and surface pH improved in both treatment groups over time. The tested silver-loaded seaweed fibre can be regarded as safe and seams to be suited for application in bio-active textiles in atopic dermatitis based on its positive in vivo activity.

Establishment and characterization of a new human functional cell line from a choriocarcinoma.

PubMed

Okabe, T; Sasaki, N; Matsuzaki, M; Imai, Y; Kaneko, Y; Matsuzaki, F; Takaku, F; Tsushima, T

1983-10-01

A new human functional tumor cell line, designated as T3M-3, has been established from a xenotransplanted choriocarcinoma grown in nude mice. One of the biggest problems of the in vitro culture of these tumor cells using the xenotransplanted tumors had been the dense contamination of fibroblasts of host nude mouse origin. In the present study, these fibroblasts were completely removed by incubating the cells with antiserum raised against nude mouse spleen cells. The cell line established from the remaining tumor cells has been successfully propagated in vitro for as long as 4 years. These cells show the morphology of epithelioid cells containing a prominent nucleus with one or two large nucleoli. The cells grow in a monolayered sheet with the population-doubling time of 19 hr. The cells show perfect tumor takes when they are reinoculated into nude mice. Chromosomal analysis revealed that the cell is a human aneuploid one with a hypotriploid mode. These cultured cells maintained well the function of secreting large amounts of human chorionic gonadotropin, progesterone, and estrogen. The secretion of human chorionic gonadotropin and progesterone by these cells is enhanced by stimulation with tumor promoters, such as 12-O-tetradecanoylphorbol-13-acetate and teleocidin B, or with epidermal growth factor in a dose-and time-dependent manner. Interestingly, however, the tumor promoters did not exert a marked effect on the cellular binding of epidermal growth factor, indicating that the receptors for these reagents in T3M-3 cells are not shared by epidermal growth factor.

RSL Class I Genes Controlled the Development of Epidermal Structures in the Common Ancestor of Land Plants.

PubMed

Proust, Hélène; Honkanen, Suvi; Jones, Victor A S; Morieri, Giulia; Prescott, Helen; Kelly, Steve; Ishizaki, Kimitsune; Kohchi, Takayuki; Dolan, Liam

2016-01-11

The colonization of the land by plants, sometime before 470 million years ago, was accompanied by the evolution tissue systems [1-3]. Specialized structures with diverse functions-from nutrient acquisition to reproduction-derived from single cells in the outermost layer (epidermis) were important sources of morphological innovation at this time [2, 4, 5]. In extant plants, these structures may be unicellular extensions, such as root hairs or rhizoids [6-9], or multicellular structures, such as asexual propagules or secretory hairs (papillae) [10-12]. Here, we show that a ROOTHAIR DEFECTIVE SIX-LIKE (RSL) class I basic helix-loop-helix transcription factor positively regulates the development of the unicellular and multicellular structures that develop from individual cells that expand out of the epidermal plane of the liverwort Marchantia polymorpha; mutants that lack MpRSL1 function do not develop rhizoids, slime papillae, mucilage papillae, or gemmae. Furthermore, we discovered that RSL class I genes are also required for the development of multicellular axillary hairs on the gametophyte of the moss Physcomitrella patens. Because class I RSL proteins also control the development of rhizoids in mosses and root hairs in angiosperms [13, 14], these data demonstrate that the function of RSL class I genes was to control the development of structures derived from single epidermal cells in the common ancestor of the land plants. Class I RSL genes therefore controlled the generation of adaptive morphological diversity as plants colonized the land from the water. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

Hyaluronan Does Not Regulate Human Epidermal Keratinocyte Proliferation and Differentiation*

PubMed Central

Malaisse, Jérémy; Pendaries, Valérie; Hontoir, Fanny; De Glas, Valérie; Van Vlaender, Daniel; Simon, Michel; Lambert de Rouvroit, Catherine; Poumay, Yves; Flamion, Bruno

2016-01-01

Hyaluronan (HA) is synthesized by three HA synthases (HAS1, HAS2, and HAS3) and secreted in the extracellular matrix. In human skin, large amounts of HA are found in the dermis. HA is also synthesized by keratinocytes in the epidermis, although its epidermal functions are not clearly identified yet. To investigate HA functions, we studied the effects of HA depletion on human keratinocyte physiology within in vitro reconstructed human epidermis. Inhibition of HA synthesis with 4-methylumbelliferone (4MU) did not modify the expression profile of the epidermal differentiation markers involucrin, keratin 10, and filaggrin during tissue reconstruction. In contrast, when keratinocytes were incubated with 4MU, cell proliferation was decreased. In an attempt to rescue the proliferation function, HA samples of various mean molecular masses were added to keratinocyte cultures treated with 4MU. These samples were unable to rescue the initial proliferation rate. Furthermore, treatments with HA-specific hyaluronidase, although removing almost all HA from keratinocyte cultures, did not alter the differentiation or proliferation processes. The differences between 4MU and hyaluronidase effects did not result from differences in intracellular HA, sulfated glycosaminoglycan concentration, apoptosis, or levels of HA receptors, all of which remained unchanged. Similarly, knockdown of UDP-glucose 6-dehydrogenase (UGDH) using lentiviral shRNA effectively decreased HA production but did not affect proliferation rate. Overall, these data suggest that HA levels in the human epidermis are not directly correlated with keratinocyte proliferation and differentiation and that incubation of cells with 4MU cannot equate with HA removal. PMID:26627828

Efficacy of Epidermal Skin Grafts Over Complex, Chronic Wounds in Patients With Multiple Comorbidities.

PubMed

Fearmonti, Regina M

2016-07-01

Epidermal skin grafting presents an alternative to traditional autografts since only epidermal skin is harvested from the donor site. Split-thickness skin grafts are associated with difficulties at the donor site, including excessive pain, delayed healing, fluid loss, and unsatisfactory cosmetic results - all exacerbated in patients with comorbidities. A new automated epidermal harvesting tool (CelluTome Epidermal Harvesting System, KCI, an Acelity company, San Antonio, TX) involves concurrent application of heat and suction to normal skin to produce epidermal grafts. This article outlines the author's experience using this automated epidermal harvesting tool to harvest epidermal grafts and apply them on 23 chronic lower extremity wounds of patients with multiple comorbidities. Vacuum and heat were applied until epidermal microdomes were formed (30-45 minutes); an epidermal microdome array was collected onto a transfer dressing and applied over the wound. The automated harvesting tool yielded viable epithelium with every use. In addition to the epidermal skin graft, 16 of 23 wounds (70%) received adjunctive wound treatment, including negative pressure wound therapy, hyperbaric oxygen therapy, and/or regenerative tissue matrix. The average reepithelialization rate was 88.1% during a mean follow-up period of 76.4 days; no use of an anesthetic/operating room was required for the procedure. All donor sites were completely healed within 2 weeks without complications or scarring. Epidermal skin grafting provided a simplified, office-based grafting option with no donor site morbidity, and assisted in closure or size reduction of chronic wounds in this series.

A randomized trial comparing ReCell system of epidermal cells delivery versus classic skin grafts for the treatment of deep partial thickness burns.

PubMed

Gravante, G; Di Fede, M C; Araco, A; Grimaldi, M; De Angelis, B; Arpino, A; Cervelli, V; Montone, A

2007-12-01

Our purpose was to directly compare results obtained with the ReCell system and the classic skin grafting for epidermal replacement in deep partial thickness burns. We recruited all patients with deep partial thickness burns admitted at the Burn Centre of S. Eugenio Hospital in Rome over 2 years. Enrollment was conducted with a controlled strategy--sampling chart--that allowed homogeneous groups (ReCell and skin grafting) for age, gender, type of burns and total burn surface area (TBSA). We evaluated as primary endpoints of the study the (i) time for complete epithelization (both treated area and biopsy site) and (ii) aesthetic and functional quality of the epithelization (color, joint contractures). Secondary endpoints were the assessment of infections, inflammations or any adverse effects of the ReCell procedure, particular medications assumed, postoperative pain. Eighty-two patients were analyzed in two homogeneous groups. All of them received adequate epidermal replacement, but skin grafting was faster than ReCell (p<0.05). On the contrary, ReCell biopsy areas and postoperative pain were smaller than classic grafting (p<0.05). The aesthetic and functional outcomes were similar between procedures. ReCell is a feasible, simple and safe technique. It gives similar results to skin grafting but, harvesting minor areas, can open possible future applications in the management of large-burns patients.

A Barley ROP GTPase ACTIVATING PROTEIN Associates with Microtubules and Regulates Entry of the Barley Powdery Mildew Fungus into Leaf Epidermal Cells[C][W

PubMed Central

Hoefle, Caroline; Huesmann, Christina; Schultheiss, Holger; Börnke, Frederik; Hensel, Götz; Kumlehn, Jochen; Hückelhoven, Ralph

2011-01-01

Little is known about the function of host factors involved in disease susceptibility. The barley (Hordeum vulgare) ROP (RHO of plants) G-protein RACB is required for full susceptibility of the leaf epidermis to invasion by the biotrophic fungus Blumeria graminis f. sp hordei. Stable transgenic knockdown of RACB reduced the ability of barley to accommodate haustoria of B. graminis in intact epidermal leaf cells and to form hairs on the root epidermis, suggesting that RACB is a common element of root hair outgrowth and ingrowth of haustoria in leaf epidermal cells. We further identified a barley MICROTUBULE-ASSOCIATED ROP-GTPASE ACTIVATING PROTEIN (MAGAP1) interacting with RACB in yeast and in planta. Fluorescent MAGAP1 decorated cortical microtubules and was recruited by activated RACB to the cell periphery. Under fungal attack, MAGAP1-labeled microtubules built a polarized network at sites of successful defense. By contrast, microtubules loosened where the fungus succeeded in penetration. Genetic evidence suggests a function of MAGAP1 in limiting susceptibility to penetration by B. graminis. Additionally, MAGAP1 influenced the polar organization of cortical microtubules. These results add to our understanding of how intact plant cells accommodate fungal infection structures and suggest that RACB and MAGAP1 might be antagonistic players in cytoskeleton organization for fungal entry. PMID:21685259

Repeated short climatic change affects the epidermal differentiation program and leads to matrix remodeling in a human organotypic skin model.

PubMed

Boutrand, Laetitia-Barbollat; Thépot, Amélie; Muther, Charlotte; Boher, Aurélie; Robic, Julie; Guéré, Christelle; Vié, Katell; Damour, Odile; Lamartine, Jérôme

2017-01-01

Human skin is subject to frequent changes in ambient temperature and humidity and needs to cope with these environmental modifications. To decipher the molecular response of human skin to repeated climatic change, a versatile model of skin equivalent subject to "hot-wet" (40°C, 80% relative humidity [RH]) or "cold-dry" (10°C, 40% RH) climatic stress repeated daily was used. To obtain an exhaustive view of the molecular mechanisms elicited by climatic change, large-scale gene expression DNA microarray analysis was performed and modulated function was determined by bioinformatic annotation. This analysis revealed several functions, including epidermal differentiation and extracellular matrix, impacted by repeated variations in climatic conditions. Some of these molecular changes were confirmed by histological examination and protein expression. Both treatments (hot-wet and cold-dry) reduced the expression of genes encoding collagens, laminin, and proteoglycans, suggesting a profound remodeling of the extracellular matrix. Strong induction of the entire family of late cornified envelope genes after cold-dry exposure, confirmed at protein level, was also observed. These changes correlated with an increase in epidermal differentiation markers such as corneodesmosin and a thickening of the stratum corneum, indicating possible implementation of defense mechanisms against dehydration. This study for the first time reveals the complex pattern of molecular response allowing adaption of human skin to repeated change in its climatic environment.

miR-203 modulates epithelial differentiation of human embryonic stem cells towards epidermal stratification.

PubMed

Nissan, Xavier; Denis, Jérôme Alexandre; Saidani, Manoubia; Lemaitre, Gilles; Peschanski, Marc; Baldeschi, Christine

2011-08-15

The molecular mechanisms controlling the differentiation of human basal keratinocyte stem cells towards the epidermis are well characterized, whereas the earliest process leading to the specification of embryonic stem cells into keratinocytes is still not well understood. MicroRNAs are regulators of many cellular events, but evidence for microRNA acting on the differentiation of human embryonic stem cells into a specific lineage has been elusive. By using our recent protocol for obtaining functional keratinocytes from hESC, we attempted to analyze the role of microRNAs in the early stages of epidermal differentiation. Thus, we identified a set of 5 microRNAs, namely miR-200a, miR-200b, miR-203, miR-205 and miR-429, that are specifically overexpressed during the early stages of the differentiation process. Interestingly, our functional analyses revealed an instrumental role of miR-203, which had been previously shown to play a key role during the formation of the pluristratified epidermis by basal keratinocyte stem cells, in the early keratinocyte commitment. These results highlight the determinant and unique role of miR-203 during the entire process of epidermal development by extending its spectrum of action from the early commitment of embryonic stem cells to ultimate differentiation of the organ. Copyright © 2011 Elsevier Inc. All rights reserved.

Developmental patterning of sub-epidermal cells in the outer integument of Arabidopsis seeds

PubMed Central

Fiume, Elisa; Coen, Olivier; Xu, Wenjia; Lepiniec, Loïc

2017-01-01

The seed, the reproductive unit of angiosperms, is generally protected by the seed coat. The seed coat is made of one or two integuments, each comprising two epidermal cells layers and, in some cases, extra sub-epidermal cell layers. The thickness of the seed-coat affects several aspects of seed biology such as dormancy, germination and mortality. In Arabidopsis, the inner integument displays one or two sub-epidermal cell layers that originate from periclinal cell divisions of the innermost epidermal cell layer. By contrast, the outer integument was considered to be two-cell layered. Here, we show that sub-epidermal chalazal cells grow in between the epidermal outer integument cell layers to create an incomplete three-cell layered outer integument. We found that the MADS box transcription factor TRANSPARENT TESTA 16 represses growth of the chalaza and formation of sub-epidermal outer integument cells. Finally, we demonstrate that sub-epidermal cells of the outer and inner integument respond differently to the repressive mechanism mediated by FERTILIZATION INDEPENDENT SEED Polycomb group proteins and to fertilization signals. Our data suggest that integument cell origin rather than sub-epidermal cell position underlies different responses to fertilization. PMID:29141031

micro RNA 172 (miR172) signals epidermal infection and is expressed in cells primed for bacterial invasion in Lotus japonicus roots and nodules.

PubMed

Holt, Dennis B; Gupta, Vikas; Meyer, Dörte; Abel, Nikolaj B; Andersen, Stig U; Stougaard, Jens; Markmann, Katharina

2015-10-01

Legumes interact with rhizobial bacteria to form nitrogen-fixing root nodules. Host signalling following mutual recognition ensures a specific response, but is only partially understood. Focusing on the stage of epidermal infection with Mesorhizobium loti, we analysed endogenous small RNAs (sRNAs) of the model legume Lotus japonicus to investigate their involvement in host response regulation. We used Illumina sequencing to annotate the L. japonicus sRNA-ome and isolate infection-responsive sRNAs, followed by candidate-based functional characterization. Sequences from four libraries revealed 219 novel L. japonicus micro RNAs (miRNAs) from 114 newly assigned families, and 76 infection-responsive sRNAs. Unlike infection-associated coding genes such as NODULE INCEPTION (NIN), a micro RNA 172 (miR172) isoform showed strong accumulation in dependency of both Nodulation (Nod) factor and compatible rhizobia. The genetics of miR172 induction support the existence of distinct epidermal and cortical signalling events. MIR172a promoter activity followed a previously unseen pattern preceding infection thread progression in epidermal and cortical cells. Nodule-associated miR172a expression was infection-independent, representing the second of two genetically separable activity waves. The combined data provide a valuable resource for further study, and identify miR172 as an sRNA marking successful epidermal infection. We show that miR172 acts upstream of several APETALA2-type (AP2) transcription factors, and suggest that it has a role in fine-tuning AP2 levels during bacterial symbiosis. © 2015 The Authors. New Phytologist © 2015 New Phytologist Trust.

Hollow silicon microneedle array based trans-epidermal antiemetic patch for efficient management of chemotherapy induced nausea and vomiting

NASA Astrophysics Data System (ADS)

Kharbikar, Bhushan N.; Kumar S., Harish; Kr., Sindhu; Srivastava, Rohit

2015-12-01

Chemotherapy Induced Nausea and Vomiting (CINV) is a serious health concern in the treatment of cancer patients. Conventional routes for administering anti-emetics (i.e. oral and parenteral) have several drawbacks such as painful injections, poor patient compliance, dependence on skilled personnel, non-affordability to majority of population (parenteral), lack of programmability and suboptimal bioavailability (oral). Hence, we have developed a trans-epidermal antiemetic drug delivery patch using out-of-plane hollow silicon microneedle array. Microneedles are pointed micron-scale structures that pierce the epidermal layer of skin to reach dermal blood vessels and can directly release the drug in their vicinity. They are painless by virtue of avoiding significant contact with dermal sensory nerve endings. This alternate approach gives same pharmacodynamic effects as par- enteral route at a sparse drug-dose requirement, hence negligible side-effects and improved patient compliance. Microneedle design attributes were derived by systematic study of human skin anatomy, natural micron-size structures like wasp-sting and cactus-spine and multi-physics simulations. We used deep reactive ion etching with Bosch process and optimized recipe of gases to fabricate high-aspect-ratio hollow silicon microneedle array. Finally, microneedle array and polydimethylsiloxane drug reservoir were assembled to make finished anti-emetic patch. We assessed microneedles mechanical stability, physico-chemical properties and performed in-vitro, ex- vivo and in-vivo studies. These studies established functional efficacy of the device in trans-epidermal delivery of anti-emetics, its programmability, ease of use and biosafety. Thus, out-of-plane hollow silicon microneedle array trans-epidermal antiemetic patch is a promising strategy for painless and effective management of CINV at low cost in mainstream healthcare.

The receptor tyrosine kinase ERBB4 is expressed in skin keratinocytes and influences epidermal proliferation.

PubMed

Hoesl, Christine; Röhrl, Jennifer M; Schneider, Marlon R; Dahlhoff, Maik

2018-04-01

The epidermal growth factor receptor (EGFR) and associated receptors ERBB2 and ERBB3 are important for skin development and homeostasis. To date, ERBB4 could not be unambiguously identified in the epidermis. The aim of this study was to analyze the ERBB-receptor family with a special focus on ERBB4 in vitro in human keratinocytes and in vivo in human and murine epidermis. We compared the transcript levels of all ERBB-receptors and the seven EGFR-ligands in HaCaT and A431 cells. ERBB-receptor activity was analyzed after epidermal growth factor (EGF) stimulation by Western blot analysis. The location of the receptors was investigated by immunofluorescence in human keratinocytes and skin. Finally, we investigated the function of ERBB4 in the epidermis of skin-specific ERBB4-knockout mice. After EGF stimulation, all ligands were upregulated except for epigen. Expression levels of EGFR were unchanged, but all other ERBB-receptors were down-regulated after EGF stimulation, although all ERBB-receptors were phosphorylated. We detected ERBB4 at mRNA and protein levels in both human epidermal cell lines and in the basal layer of human and murine epidermis. Skin-specific ERBB4-knockout mice revealed a significantly reduced epidermal thickness with a decreased proliferation rate. ERBB4 is expressed in the basal layer of human epidermis and cultured keratinocytes as well as in murine epidermis. Moreover, ERBB4 is phosphorylated in HaCaT cells due to EGF stimulation, and its deletion in murine epidermis affects skin thickness by decreasing proliferation. ERBB4 is expressed in human keratinocytes and plays a role in murine skin homeostasis. Copyright © 2018 Elsevier B.V. All rights reserved.

Live imaging of collagen deposition during skin development and repair in a collagen I - GFP fusion transgenic zebrafish line.

PubMed

Morris, Josephine L; Cross, Stephen J; Lu, Yinhui; Kadler, Karl E; Lu, Yongbo; Dallas, Sarah L; Martin, Paul

2018-06-06

Fibrillar collagen is a major component of many tissues but has been difficult to image in vivo using transgenic approaches because of problems associated with establishing cells and organisms that generate GFP-fusion collagens that can polymerise into functional fibrils. Here we have developed and characterised GFP and mCherry collagen-I fusion zebrafish lines with basal epidermal-specific expression. We use these lines to reveal the dynamic nature of collagen-I fibril deposition beneath the developing embryonic epidermis, as well as the repair of this collagen meshwork following wounding. Transmission electron microscope studies show that these transgenic lines faithfully reproduce the collagen ultrastructure present in wild type larval skin. During skin development we show that collagen I is deposited by basal epidermal cells initially in fine filaments that are largely randomly orientated but are subsequently aligned into a cross-hatch, orthogonal sub-epithelial network by embryonic day 4. Following skin wounding, we see that sub-epidermal collagen is re-established in the denuded domain, initially as randomly orientated wisps that subsequently become bonded to the undamaged collagen and aligned in a way that recapitulates developmental deposition of sub-epidermal collagen. Crossing our GFP-collagen line against one with tdTomato marking basal epidermal cell membranes reveals how much more rapidly wound re-epithelialisation occurs compared to the re-deposition of collagen beneath the healed epidermis. By use of other tissue specific drivers it will be possible to establish zebrafish lines to enable live imaging of collagen deposition and its remodelling in various other organs in health and disease. Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.

Stomatal lock-open, a consequence of epidermal cell death, follows transient suppression of stomatal opening in barley attacked by Blumeria graminis.

PubMed

Prats, Elena; Gay, Alan P; Mur, Luis A J; Thomas, Barry J; Carver, Timothy L W

2006-01-01

Blumeria graminis f.sp. hordei (Bgh) attack disrupted stomatal behaviour, and hence leaf water conductance (g(l)), in barley genotypes Pallas and Risø-S (susceptible), P01 (with Mla1 conditioning a hypersensitive response; HR), and P22 and Risø-R (with mlo5 conditioning papilla-based penetration resistance). Inoculation caused some stomatal closure well before the fungus attempted infection. Coinciding with epidermal cell penetration, stomatal opening in light was also impeded, although stomata of susceptible and mlo5 lines remained largely able to close in darkness. Following infection, in susceptible lines stomata closed in darkness but opening in light was persistently impeded. In Risø-R, stomata recovered nearly complete function by approximately 30 h after inoculation, i.e. after penetration resistance was accomplished. In P01, stomata became locked open and unable to close in darkness shortly after epidermal cells died due to HR. In the P22 background, mlo5 penetration resistance was often followed by consequential death of attacked cells, and here too stomata became locked open, but not until approximately 24 h after pathogen attack had ceased. The influence of epidermal cell death was localized, and only affected stomata within one or two cells distance. These stomata were unable to close not only in darkness but also after application of abscisic acid and in wilted leaves suffering drought. Thus, resistance to Bgh based on HR or associated with cell death may have previously unsuspected negative consequences for the physiological health of apparently 'disease-free' plants. The results are discussed in relation to the control of stomatal aperture in barley by epidermal cells.

Genetics Home Reference: Stevens-Johnson syndrome/toxic epidermal necrolysis

MedlinePlus

... Conditions Stevens-Johnson syndrome/toxic epidermal necrolysis Stevens-Johnson syndrome/toxic epidermal necrolysis Printable PDF Open All ... to view the expand/collapse boxes. Description Stevens-Johnson syndrome/toxic epidermal necrolysis (SJS/TEN) is a ...

Nogo Receptor Homolog NgR2 Expressed in Sensory DRG Neurons Controls Epidermal Innervation by Interaction with Versican

PubMed Central

Bäumer, Bastian E.; Kurz, Antje; Borrie, Sarah C.; Sickinger, Stephan; Dours-Zimmermann, María T.; Zimmermann, Dieter R.

2014-01-01

Primary sensory afferents of the dorsal root ganglion (DRG) that innervate the skin detect a wide range of stimuli, such as touch, temperature, pain, and itch. Different functional classes of nociceptors project their axons to distinct target zones within the developing skin, but the molecular mechanisms that regulate target innervation are less clear. Here we report that the Nogo66 receptor homolog NgR2 is essential for proper cutaneous innervation. NgR2−/− mice display increased density of nonpeptidergic nociceptors in the footpad and exhibit enhanced sensitivity to mechanical force and innocuous cold temperatures. These sensory deficits are not associated with any abnormality in morphology or density of DRG neurons. However, deletion of NgR2 renders nociceptive nonpeptidergic sensory neurons insensitive to the outgrowth repulsive activity of skin-derived Versican. Biochemical evidence shows that NgR2 specifically interacts with the G3 domain of Versican. The data suggest that Versican/NgR2 signaling at the dermo-epidermal junction acts in vivo as a local suppressor of axonal plasticity to control proper density of epidermal sensory fiber innervation. Our findings not only reveal the existence of a novel and unsuspected mechanism regulating epidermal target innervation, but also provide the first evidence for a physiological role of NgR2 in the peripheral nervous system. PMID:24478347

Nogo receptor homolog NgR2 expressed in sensory DRG neurons controls epidermal innervation by interaction with Versican.

PubMed

Bäumer, Bastian E; Kurz, Antje; Borrie, Sarah C; Sickinger, Stephan; Dours-Zimmermann, María T; Zimmermann, Dieter R; Bandtlow, Christine E

2014-01-29

Primary sensory afferents of the dorsal root ganglion (DRG) that innervate the skin detect a wide range of stimuli, such as touch, temperature, pain, and itch. Different functional classes of nociceptors project their axons to distinct target zones within the developing skin, but the molecular mechanisms that regulate target innervation are less clear. Here we report that the Nogo66 receptor homolog NgR2 is essential for proper cutaneous innervation. NgR2(-/-) mice display increased density of nonpeptidergic nociceptors in the footpad and exhibit enhanced sensitivity to mechanical force and innocuous cold temperatures. These sensory deficits are not associated with any abnormality in morphology or density of DRG neurons. However, deletion of NgR2 renders nociceptive nonpeptidergic sensory neurons insensitive to the outgrowth repulsive activity of skin-derived Versican. Biochemical evidence shows that NgR2 specifically interacts with the G3 domain of Versican. The data suggest that Versican/NgR2 signaling at the dermo-epidermal junction acts in vivo as a local suppressor of axonal plasticity to control proper density of epidermal sensory fiber innervation. Our findings not only reveal the existence of a novel and unsuspected mechanism regulating epidermal target innervation, but also provide the first evidence for a physiological role of NgR2 in the peripheral nervous system.

Glycerophospholipid Profiles of Bats with White-Nose Syndrome.

PubMed

Pannkuk, Evan L; McGuire, Liam P; Warnecke, Lisa; Turner, James M; Willis, Craig K R; Risch, Thomas S

2015-01-01

Pseudogymnoascus destructans is an ascomycetous fungus responsible for the disease dubbed white-nose syndrome (WNS) and massive mortalities of cave-dwelling bats. The fungus infects bat epidermal tissue, causing damage to integumentary cells and pilosebaceous units. Differences in epidermal lipid composition caused by P. destructans infection could have drastic consequences for a variety of physiological functions, including innate immune efficiency and water retention. While bat surface lipid and stratum corneum lipid composition have been described, the differences in epidermal lipid content between healthy tissue and P. destructans-infected tissue have not been documented. In this study, we analyzed the effect of wing damage from P. destructans infection on the epidermal polar lipid composition (glycerophospholipids [GPs] and sphingomyelin) of little brown bats (Myotis lucifugus). We hypothesized that infection would lead to lower levels of total lipid or higher oxidized lipid product proportions. Polar lipids from three damaged and three healthy wing samples were profiled by electrospray ionization tandem mass spectrometry. We found lower total broad lipid levels in damaged tissue, specifically ether-linked phospholipids, lysophospholipids, phosphatidylcholine, and phosphatidylethanolamine. Thirteen individual GP species from four broad GP classes were present in higher amounts in healthy tissue. Six unsaturated GP species were absent in damaged tissue. Our results confirm that P. destructans infection leads to altered lipid profiles. Clinical signs of WNS may include lower lipid levels and lower proportions of unsaturated lipids due to cellular and glandular damage.

Involvement of auxin and a homeodomain-leucine zipper I gene in rhizoid development of the moss Physcomitrella patens.

PubMed

Sakakibara, Keiko; Nishiyama, Tomoaki; Sumikawa, Naomi; Kofuji, Rumiko; Murata, Takashi; Hasebe, Mitsuyasu

2003-10-01

Differentiation of epidermal cells is important for plants because they are in direct contact with the environment. Rhizoids are multicellular filaments that develop from the epidermis in a wide range of plants, including pteridophytes, bryophytes, and green algae; they have similar functions to root hairs in vascular plants in that they support the plant body and are involved in water and nutrient absorption. In this study, we examined mechanisms underlying rhizoid development in the moss, Physcomitrella patens, which is the only land plant in which high-frequency gene targeting is possible. We found that rhizoid development can be split into two processes: determination and differentiation. Two types of rhizoids with distinct developmental patterns (basal and mid-stem rhizoids) were recognized. The development of basal rhizoids from epidermal cells was induced by exogenous auxin, while that of mid-stem rhizoids required an unknown factor in addition to exogenous auxin. Once an epidermal cell had acquired a rhizoid initial cell fate, expression of the homeodomain-leucine zipper I gene Pphb7 was induced. Analysis of Pphb7 disruptant lines showed that Pphb7 affects the induction of pigmentation and the increase in the number and size of chloroplasts, but not the position or number of rhizoids. This is the first report on the involvement of a homeodomain-leucine zipper I gene in epidermal cell differentiation.

Protective role of 6-formylindolo[3,2-b]carbazole (FICZ), an endogenous ligand for arylhydrocarbon receptor, in chronic mite-induced dermatitis.

PubMed

Kiyomatsu-Oda, Mari; Uchi, Hiroshi; Morino-Koga, Saori; Furue, Masutaka

2018-06-01

Chronic eczema such as atopic dermatitis imposes significant socio-econo-psychologic burdens on the affected individuals. In addition to conventional topical treatments, phototherapy is recommended for patients with extensive lesions. Although immunosuppression is believed to explain its primary effectiveness, the underlying mechanisms of phototherapy remain unsolved. Ultraviolet irradiation generates various tryptophan photoproducts including 6-formylindolo[3,2-b]-carbazole (FICZ). FICZ is known to be a potent endogenous agonist for aryl hydrocarbon receptor (AHR); however, the biological role of FICZ in chronic eczema is unknown. To investigate the effect of FICZ on chronic eczema such as atopic dermatitis. We stimulated HaCaT cells and normal human epidermal keratinocytes (NHEKs) with or without FICZ and then performed quantitative reverse transcriptase polymerase chain reaction, immunofluorescence, and siRNA treatment. We used the atopic dermatitis-like NC/Nga murine model and treated the mice for 2 weeks with either Vaseline ® as a control, FICZ ointment, or betamethasone 17-valerate ointment. The dermatitis score, transepidermal water loss, histology, and expression of skin barrier genes and proteins were evaluated. FICZ significantly upregulated the gene expression of filaggrin in both HaCaT cells and NHEKs in an AHR-dependent manner, but did not affect the gene expression of other barrier-related proteins. In addition, FICZ improved the atopic dermatitis-like skin inflammation, clinical scores, and transepidermal water loss in NC/Nga mice compared with those of control mice. On histology, FICZ significantly reduced the epidermal and dermal thickness as well as the number of mast cells. Topical FICZ also significantly reduced the gene expression of Il22. These findings highlight the beneficial role of FICZ-AHR and provide a new strategic basis for developing new drugs for chronic eczema. Copyright © 2018 Japanese Society for Investigative Dermatology. Published by Elsevier B.V. All rights reserved.

Distinct molecular signatures of mild extrinsic and intrinsic atopic dermatitis.

PubMed

Martel, Britta C; Litman, Thomas; Hald, Andreas; Norsgaard, Hanne; Lovato, Paola; Dyring-Andersen, Beatrice; Skov, Lone; Thestrup-Pedersen, Kristian; Skov, Søren; Skak, Kresten; Poulsen, Lars K

2016-06-01

Atopic dermatitis (AD) is a common inflammatory skin disease with underlying defects in epidermal function and immune responses. In this study, we used microarray analysis to investigate differences in gene expression in lesional skin from patients with mild extrinsic or intrinsic AD compared to skin from healthy controls and from lesional psoriasis skin. The primary aim was to identify differentially expressed genes involved in skin barrier formation and inflammation, and to compare our results with those reported for patients with moderate and severe AD. In contrast to severe AD, expression of the majority of genes associated with skin barrier formation was unchanged or upregulated in patients with mild AD compared to normal healthy skin. Among these, no significant differences in the expression of filaggrin (FLG) and loricrin at both mRNA and protein level were found in lesional skin from patients with mild AD, despite the presence of heterozygous FLG mutations in the majority of patients with mild extrinsic AD. Several inflammation-associated genes such as S100A9, MMP12, CXCL10 and CCL18 were highly expressed in lesional skin from patients with mild psoriasis and were also increased in patients with mild extrinsic and intrinsic AD similar to previous reports for severe AD. Interestingly, expression of genes involved in inflammatory responses in intrinsic AD resembled that of psoriasis more than that of extrinsic AD. Overall, differences in expression of inflammation-associated genes found among patients with mild intrinsic and extrinsic AD correlated with previous findings for patients with severe intrinsic and extrinsic AD. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Imiquimod-induced psoriasis-like inflammation in differentiated Human keratinocytes: Its evaluation using curcumin.

PubMed

Varma, Sandeep R; Sivaprakasam, Thiyagarajan O; Mishra, Abheepsa; Prabhu, Sunil; M, Rafiq; P, Rangesh

2017-10-15

Psoriasis is considered to be a systemic disease of immune dysfunction. It is still unclear what triggers the inflammatory cascade associated with psoriasis but recent evidences suggest the vital role of IL-23/IL-17A cytokine axis in etiology of psoriasis. Several studies have been conducted in psoriatic-like animal models but ethical issues and complexity surrounding it halts the screening of new anti-psoriatic drug candidates. Hence, in this study, we developed a new in-vitro model for psoriasis using imiquimod (IMQ) induced differentiated HaCaT cells which could be used for screening of new anti-psoriatic drug candidates. The differentiated HaCaT cells were treated with IMQ (100μM) to induce psoriatic like inflammation and its effect was investigated using a natural anti-psoriatic compound, curcumin. The proliferation of psoriatic-like cells was inhibited by curcumin at 25 and 50µM concentrations. The psoriatic-like cells decreased in number with increase in apoptotic and dead cells upon curcumin treatment. Curcumin inhibited the proliferation of IMQ-induced differentiated HaCaT cells (Psoriatic-like cells) by down-regulation of pro-inflammatory cytokines, interleukin-17, tumor necrosis factor-α, interferon-γ, and interleukin-6. Apart from this, curcumin significantly enhanced the skin-barrier function by up-regulation of involucrin (iNV) and filaggrin (FLG), the regulators of epidermal skin barrier. The IMQ-induced differentiated HaCaT in vitro model recapitulated some aspects of the psoriasis pathogenesis similar to murine model. Henceforth, we conclude that this model may be used for rapid screening of anti-psoriatic drug candidates and warrant further mechanistic studies. Copyright © 2017 Elsevier B.V. All rights reserved.

Epidermal Viral Immunity Induced by CD8α+ Dendritic Cells But Not by Langerhans Cells

NASA Astrophysics Data System (ADS)

Allan, Rhys S.; Smith, Chris M.; Belz, Gabrielle T.; van Lint, Allison L.; Wakim, Linda M.; Heath, William R.; Carbone, Francis R.

2003-09-01

The classical paradigm for dendritic cell function derives from the study of Langerhans cells, which predominate within skin epidermis. After an encounter with foreign agents, Langerhans cells are thought to migrate to draining lymph nodes, where they initiate T cell priming. Contrary to this, we show here that infection of murine epidermis by herpes simplex virus did not result in the priming of virus-specific cytotoxic T lymphocytes by Langerhans cells. Rather, the priming response required a distinct CD8α+ dendritic cell subset. Thus, the traditional view of Langerhans cells in epidermal immunity needs to be revisited to accommodate a requirement for other dendritic cells in this response.

Influence of DMPS on the water retention capacity of electroporated stratum corneum: ATR-FTIR study.

PubMed

Sckolnick, Maria; Hui, Sek-Wen; Sen, Arindam

2008-02-28

Anionic lipids like phosphatidylserine are known to significantly enhance electroporation mediated transepidermal transport of polar solutes of molecular weights up to 10kDa. The underlying mechanism of the effect of anionic lipids on transdermal transport is not fully understood. The main barrier to transdermal transport lies within the intercellular lipid matrix (ILM) of the stratum corneum (SC) and our previous studies indicate that dimyristoyl phosphatidylserine (DMPS) can perturb the packing of this lipid matrix. Here we report on our investigation on water retention in the SC following electroporation in the presence and the absence of DMPS. The water content in the outer most layers of the SC of full thickness porcine skin was determined using ATR-FTIR-spectroscopy. The results show that in the presence of DMPS, the SC remains in a state of enhanced hydration for longer periods after electroporation. This increase in water retention in the SC by DMPS is likely to play an important role in trans-epidermal transport, since improved hydration of the skin barrier can be expected to increase the partitioning of polar solutes and possibly the permeability.

The Arabidopsis translatome cell-specific mRNA atlas: Mining suberin and cutin lipid monomer biosynthesis genes as an example for data application.

PubMed

Mustroph, Angelika; Bailey-Serres, Julia

2010-03-01

Plants consist of distinct cell types distinguished by position, morphological features and metabolic activities. We recently developed a method to extract cell-type specific mRNA populations by immunopurification of ribosome-associated mRNAs. Microarray profiles of 21 cell-specific mRNA populations from seedling roots and shoots comprise the Arabidopsis Translatome dataset. This gene expression atlas provides a new tool for the study of cell-specific processes. Here we provide an example of how genes involved in a pathway limited to one or few cell-types can be further characterized and new candidate genes can be predicted. Cells of the root endodermis produce suberin as an inner barrier between the cortex and stele, whereas the shoot epidermal cells form cutin as a barrier to the external environment. Both polymers consist of fatty acid derivates, and share biosynthetic origins. We use the Arabidopsis Translatome dataset to demonstrate the significant cell-specific expression patterns of genes involved in those biosynthetic processes and suggest new candidate genes in the biosynthesis of suberin and cutin.

Micromixer Based Preparation of Functionalized Liposomes and Targeting Drug Delivery.

PubMed

Jia, Xiangqian; Wang, Weizhi; Han, Qiuju; Wang, Zihua; Jia, Yunhong; Hu, Zhiyuan

2016-04-14

We present here a specific targeting nanocarrier system by functionalization of liposomes with one new type of breast cancer targeting peptide (H6, YLFFVFER) by a micromixer with high efficiency. Antitumor drugs could be successfully delivered into human epidermal growth factor receptor 2 (HER2) positive breast cancer cells with high efficiency in both in vivo and ex vivo models.

Cell-free synthesis of functional human epidermal growth factor receptor: Investigation of ligand-independent dimerization in Sf21 microsomal membranes using non-canonical amino acids

PubMed Central

Quast, Robert B.; Ballion, Biljana; Stech, Marlitt; Sonnabend, Andrei; Varga, Balázs R.; Wüstenhagen, Doreen A.; Kele, Péter; Schiller, Stefan M.; Kubick, Stefan

2016-01-01

Cell-free protein synthesis systems represent versatile tools for the synthesis and modification of human membrane proteins. In particular, eukaryotic cell-free systems provide a promising platform for their structural and functional characterization. Here, we present the cell-free synthesis of functional human epidermal growth factor receptor and its vIII deletion mutant in a microsome-containing system derived from cultured Sf21 cells. We provide evidence for embedment of cell-free synthesized receptors into microsomal membranes and asparagine-linked glycosylation. Using the cricket paralysis virus internal ribosome entry site and a repetitive synthesis approach enrichment of receptors inside the microsomal fractions was facilitated thereby providing analytical amounts of functional protein. Receptor tyrosine kinase activation was demonstrated by monitoring receptor phosphorylation. Furthermore, an orthogonal cell-free translation system that provides the site-directed incorporation of p-azido-L-phenylalanine is characterized and applied to investigate receptor dimerization in the absence of a ligand by photo-affinity cross-linking. Finally, incorporated azides are used to generate stable covalently linked receptor dimers by strain-promoted cycloaddition using a novel linker system. PMID:27670253

Transient gene expression in epidermal cells of plant leaves by biolistic DNA delivery.

PubMed

Ueki, Shoko; Magori, Shimpei; Lacroix, Benoît; Citovsky, Vitaly

2013-01-01

Transient gene expression is a useful approach for studying the functions of gene products. In the case of plants, Agrobacterium infiltration is a method of choice for transient introduction of genes for many species. However, this technique does not work efficiently in some species, such as Arabidopsis thaliana. Moreover, the infection of Agrobacterium is known to induce dynamic changes in gene expression patterns in the host plants, possibly affecting the function and localization of the proteins to be tested. These problems can be circumvented by biolistic delivery of the genes of interest. Here, we present an optimized protocol for biolistic delivery of plasmid DNA into epidermal cells of plant leaves, which can be easily performed using the Bio-Rad Helios gene gun system. This protocol allows efficient and reproducible transient expression of diverse genes in Arabidopsis, Nicotiana benthamiana and N. tabacum, and is suitable for studies of the biological function and subcellular localization of the gene products directly in planta. The protocol also can be easily adapted to other species by optimizing the delivery gas pressure.

Adult epidermal Notch activity induces dermal accumulation of T cells and neural crest derivatives through upregulation of jagged 1.

PubMed

Ambler, Carrie A; Watt, Fiona M

2010-11-01

Notch signalling regulates epidermal differentiation and tumour formation via non-cell autonomous mechanisms that are incompletely understood. This study shows that epidermal Notch activation via a 4-hydroxy-tamoxifen-inducible transgene caused epidermal thickening, focal detachment from the underlying dermis and hair clumping. In addition, there was dermal accumulation of T lymphocytes and stromal cells, some of which localised to the blisters at the epidermal-dermal boundary. The T cell infiltrate was responsible for hair clumping but not for other Notch phenotypes. Notch-induced stromal cells were heterogeneous, expressing markers of neural crest, melanocytes, smooth muscle and peripheral nerve. Although Slug1 expression was expanded in the epidermis, the stromal cells did not arise through epithelial-mesenchymal transition. Epidermal Notch activation resulted in upregulation of jagged 1 in both epidermis and dermis. When Notch was activated in the absence of epidermal jagged 1, jagged 1 was not upregulated in the dermis, and epidermal thickening, blister formation, accumulation of T cells and stromal cells were inhibited. Gene expression profiling revealed that epidermal Notch activation resulted in upregulation of several growth factors and cytokines, including TNFα, the expression of which was dependent on epidermal jagged 1. We conclude that jagged 1 is a key mediator of non-cell autonomous Notch signalling in skin.

TORNADO1 regulates root epidermal patterning through the WEREWOLF pathway in Arabidopsis thaliana.

PubMed

Kwak, Su-Hwan; Song, Sang-Kee; Lee, Myeong Min; Schiefelbein, John

2015-01-01

Cell fate in the root epidermis of Arabidopsis thaliana is determined in a position-dependent manner. SCRAMBLED (SCM), an atypical leucine-rich repeat receptor-like kinase, mediates this positional regulation via its effect on WEREWOLF (WER) expression, and subsequently, its downstream transcription factor, GLABRA2 (GL2), which are required for nonhair cell development. Previously, TORNADO1 (TRN1), a plant-specific protein with a leucine-rich repeat ribonuclease inhibitor-like domain, was shown to be required for proper epidermal patterning in Arabidopsis roots. In this work, we analyzed the possible involvement of TRN1 in the known root epidermal gene network. We discovered that the trn1 mutant caused the ectopic expression of WER and the randomized expression of GL2 and EGL3. This suggests that TRN1 regulates the position-dependent cell fate determination by affecting WER expression in Arabidopsis root epidermis. Additionally, the distinct phenotypes of the aerial parts of the trn1-t and scm-2 mutant suggest that TRN1 and SCM might have different functions in the development of aerial parts.

TORNADO1 regulates root epidermal patterning through the WEREWOLF pathway in Arabidopsis thaliana

PubMed Central

Kwak, Su-Hwan; Song, Sang-Kee; Lee, Myeong Min; Schiefelbein, John

2015-01-01

Cell fate in the root epidermis of Arabidopsis thaliana is determined in a position-dependent manner. SCRAMBLED (SCM), an atypical leucine-rich repeat receptor-like kinase, mediates this positional regulation via its effect on WEREWOLF (WER) expression, and subsequently, its downstream transcription factor, GLABRA2 (GL2), which are required for nonhair cell development. Previously, TORNADO1 (TRN1), a plant-specific protein with a leucine-rich repeat ribonuclease inhibitor-like domain, was shown to be required for proper epidermal patterning in Arabidopsis roots. In this work, we analyzed the possible involvement of TRN1 in the known root epidermal gene network. We discovered that the trn1 mutant caused the ectopic expression of WER and the randomized expression of GL2 and EGL3. This suggests that TRN1 regulates the position-dependent cell fate determination by affecting WER expression in Arabidopsis root epidermis. Additionally, the distinct phenotypes of the aerial parts of the trn1-t and scm-2 mutant suggest that TRN1 and SCM might have different functions in the development of aerial parts. PMID:26451798

Tumor-Preferential Induction of Immune Responses and Epidermal Cell Death in Actinic Keratoses by Ingenol Mebutate

PubMed Central

Zibert, John R.; Schön, Margarete; Hald, Andreas; Hansen, Maria H.; Litman, Thomas; Schön, Michael P.

2016-01-01

The rapid and strong clinical efficacy of the first-in-class, ingenol mebutate, against actinic keratosis (AK) has resulted in its recent approval. We conducted the first comprehensive analysis of the cellular and molecular mode of action of topical ingenol mebutate 0.05% gel in both AK and uninvolved skin of 26 patients in a phase I, single-center, open-label, within-patient comparison. As early as 1 day after application, ingenol mebutate induced profound epidermal cell death, along with a strong infiltrate of CD4+ and CD8+ T-cells, neutrophils, and macrophages. Endothelial ICAM-1 activation became evident after 2 days. The reaction pattern was significantly more pronounced in AK compared with uninvolved skin, suggesting a tumor-preferential mode of action. Extensive molecular analyses and transcriptomic profiling of mRNAs and microRNAs demonstrated alterations in gene clusters functionally associated with epidermal development, inflammation, innate immunity, and response to wounding. Ingenol mebutate reveals a unique mode of action linking directly to anti-tumoral effects. Trial Registration: ClinicalTrials.gov NCT01387711 PMID:27612149

The homeoprotein DLX3 and tumor suppressor p53 co-regulate cell cycle progression and squamous tumor growth.

PubMed

Palazzo, E; Kellett, M; Cataisson, C; Gormley, A; Bible, P W; Pietroni, V; Radoja, N; Hwang, J; Blumenberg, M; Yuspa, S H; Morasso, M I

2016-06-16

Epidermal homeostasis depends on the coordinated control of keratinocyte cell cycle. Differentiation and the alteration of this balance can result in neoplastic development. Here we report on a novel DLX3-dependent network that constrains epidermal hyperplasia and squamous tumorigenesis. By integrating genetic and transcriptomic approaches, we demonstrate that DLX3 operates through a p53-regulated network. DLX3 and p53 physically interact on the p21 promoter to enhance p21 expression. Elevating DLX3 in keratinocytes produces a G1-S blockade associated with p53 signature transcriptional profiles. In contrast, DLX3 loss promotes a mitogenic phenotype associated with constitutive activation of ERK. DLX3 expression is lost in human skin cancers and is extinguished during progression of experimentally induced mouse squamous cell carcinoma (SCC). Reinstatement of DLX3 function is sufficient to attenuate the migration of SCC cells, leading to decreased wound closure. Our data establish the DLX3-p53 interplay as a major regulatory axis in epidermal differentiation and suggest that DLX3 is a modulator of skin carcinogenesis.

The homeoprotein DLX3 and tumor suppressor p53 co-regulate cell cycle progression and squamous tumor growth

PubMed Central

Palazzo, Elisabetta; Kellett, Meghan; Cataisson, Christophe; Gormley, Anna; Bible, Paul W.; Pietroni, Valentina; Radoja, Nadezda; Hwang, Joonsung; Blumenberg, Miroslav; Yuspa, Stuart H.; Morasso, Maria

2015-01-01

Epidermal homeostasis depends on the coordinated control of keratinocyte cell cycle. Differentiation and the alteration of this balance can result in neoplastic development. Here we report on a novel DLX3-dependent network that constrains epidermal hyperplasia and squamous tumorigenesis. By integrating genetic and transcriptomic approaches, we demonstrate that DLX3 operates through a p53-regulated network. DLX3 and p53 physically interact on the p21 promoter to enhance p21 expression. Elevating DLX3 in keratinocytes produces a G1-S blockade associated with p53 signature transcriptional profiles. In contrast, DLX3 loss promotes a mitogenic phenotype associated with constitutive activation of ERK. DLX3 expression is lost in human skin cancers and is extinquished during progression of experimentally induced mouse squamous cell carcinoma (SCC). Reinstatement of DLX3 function is sufficient to attenuate the migration of SCC cells, leading to decreased wound closure. Our data establish the DLX3-p53 interplay as a major regulatory axis in epidermal differentiation and suggest that DLX3 is a modulator of skin carcinogenesis. PMID:26522723

Fractalkine receptor is expressed in mature ovarian teratomas and required for epidermal lineage differentiation

PubMed Central

2013-01-01

Background The goal of this study was to determine a predominant cell type expressing fractalkine receptor (CX3CR1) in mature ovarian teratomas and to establish functional significance of its expression in cell differentiation. Methods Specimens of ovarian teratoma and human fetal tissues were analyzed by immunohistochemistry for CX3CR1expression. Ovarian teratocarcinoma cell line PA-1 was used as a model for cell differentiation. Results We found that the majority of the specimens contained CX3CR1-positive cells of epidermal lineage. Skin keratinocytes in fetal tissues were also CX3CR1- positive. PA-1 cells with downregulated CX3CR1 failed to express a skin keratinocyte marker cytokeratin 14 when cultured on Matrigel in the presence of a morphogen, bone morphogenic protein 4 (BMP-4), as compared to those expressing scrambled shRNA. Conclusions Here we demonstrate that CX3CR1 is expressed in both normally (fetal skin) and abnormally (ovarian teratoma) differentiated keratinocytes and is required for cell differentiation into epidermal lineage. PMID:23958497

Combined inhibition of EMMPRIN and epidermal growth factor receptor prevents the growth and migration of head and neck squamous cell carcinoma cells.

PubMed

Suzuki, Shinsuke; Ishikawa, Kazuo

2014-03-01

It has been reported that the epidermal growth factor receptor (EGFR) expression is associated with the extracellular matrix metalloproteinase inducer (EMMPRIN) in some solid tumors; however, the relationship of EMMPRIN with EGFR in head and neck cancers is not fully understood. To determine the relationship between EMMPRIN and EGFR in head and neck squamous cell carcinoma (HNSCC), HNSCC cells were stimulated with epidermal growth factor (EGF), a ligand of EGFR. EMMPRIN expression in HNSCC cells was upregulated by EGF. In addition, EGF stimulation induced HNSCC cell invasion and MMP-9 expression. This increase in invasion and MMP-9 expression was abrogated by downmodulation of EMMPRIN. Furthermore, to determine the effects of combined EMMPRIN and EGFR targeting in HNSCC, HNSCC cells were treated with an EMMPRIN function-blocking antibody and the EGFR inhibitor AG1478. This combined treatment resulted in greater inhibition of HNSCC cell proliferation and migration compared with the individual agents alone. These results suggest that EMMPRIN mediates EGFR-induced tumorigenicity and that combined targeting of EMMPRIN and EGFR may be an efficacious treatment approach.

Protein profiling of single epidermal cell types from Arabidopsis thaliana using surface-enhanced laser desorption and ionization technology.

PubMed

Ebert, Berit; Melle, Christian; Lieckfeldt, Elke; Zöller, Daniela; von Eggeling, Ferdinand; Fisahn, Joachim

2008-08-25

Here, we describe a novel approach for investigating differential protein expression within three epidermal cell types. In particular, 3000 single pavement, basal, and trichome cells from leaves of Arabidopsis thaliana were harvested by glass micro-capillaries. Subsequently, these single cell samples were joined to form pools of 100 individual cells and analyzed using the ProteinChip technology; SELDI: surface-enhanced laser desorption and ionization. As a result, numerous protein signals that were differentially expressed in the three epidermal cell types could be detected. One of these proteins was characterized by tryptical digestion and subsequent identification via tandem quadrupole-time of flight (Q-TOF) mass spectrometry. Down regulation of this sequenced small subunit precursor of ribulose-1,5 bisphosphate carboxylase(C) oxygenase(O) (RuBisCo) in trichome and basal cells indicates the sink status of these cell types that are located on the surface of A. thaliana source leaves. Based on the obtained protein profiles, we suggest a close functional relationship between basal and trichome cells at the protein level.

Ontogeny and function of murine epidermal Langerhans cells.

PubMed

Kaplan, Daniel H

2017-09-19

Langerhans cells (LCs) are epidermis-resident antigen-presenting cells that share a common ontogeny with macrophages but function as dendritic cells (DCs). Their development, recruitment and retention in the epidermis is orchestrated by interactions with keratinocytes through multiple mechanisms. LC and dermal DC subsets often show functional redundancy, but LCs are required for specific types of adaptive immune responses when antigen is concentrated in the epidermis. This Review will focus on those developmental and functional properties that are unique to LCs.

Ischemia-reperfusion impairs blood-brain barrier function and alters tight junction protein expression in the ovine fetus

PubMed Central

Chen, Xiaodi; Threlkeld, Steven W.; Cummings, Erin E.; Juan, Ilona; Makeyev, Oleksandr; Besio, Walter G.; Gaitanis, John; Banks, William A.; Sadowska, Grazyna B.; Stonestreet, Barbara S.

2012-01-01

The blood-brain barrier is a restrictive interface between the brain parenchyma and the intravascular compartment. Tight junctions contribute to the integrity of the blood-brain barrier. Hypoxic-ischemic damage to the blood-brain barrier could be an important component of fetal brain injury. We hypothesized that increases in blood-brain barrier permeability after ischemia depend upon the duration of reperfusion and that decreases in tight junction proteins are associated with the ischemia-related impairment in blood-brain barrier function in the fetus. Blood-brain barrier function was quantified with the blood-to-brain transfer constant (Ki) and tight junction proteins by Western immunoblot in fetal sheep at 127 days-of-gestation without ischemia, and 4-, 24-, or 48-h after ischemia. The largest increase in Ki (P<0.05) was 4-h after ischemia. Occludin and claudin-5 expressions decreased at 4-h, but returned toward control levels 24- and 48-h after ischemia. Zonula occludens-1 and -2 decreased after ischemia. Inverse correlations between Ki and tight junction proteins suggest that the decreases in tight junction proteins contribute to impaired blood-brain barrier function after ischemia. We conclude that impaired blood-brain barrier function is an important component of hypoxic-ischemic brain injury in the fetus, and that increases in quantitatively measured barrier permeability (Ki) change as a function of the duration of reperfusion after ischemia. The largest increase in permeability occurs 4-h after ischemia and blood-brain barrier function improves early after injury because the blood-brain barrier is less permeable 24- and 48- than 4-h after ischemia. Changes in the tight junction molecular composition are associated with increases in blood-brain barrier permeability after ischemia. PMID:22986172

DOE Office of Scientific and Technical Information (OSTI.GOV)

Balasubramanian, Sivaprakasam; Eckert, Richard L., E-mail: reckert@umaryland.edu

We have proposed that it is important to examine the impact of chemopreventive agents on the function of normal human epidermal keratinocytes since these cells comprise the barrier that protects the body from a range of environmental insults. In this context, it is widely appreciated that cancer may be retarded by consumption or topical application of naturally occurring food-derived chemopreventive agents. Our studies show that (-)-epigallocatechin-3-gallate (EGCG), a green tea-derived polyphenol, acts to enhance the differentiation of normal human keratinocytes as evidenced by its ability to increase involucrin (hINV), transglutaminase type 1 (TG1) and caspase-14 gene expression. EGCG also stimulatesmore » keratinocyte morphological differentiation. These actions of EGCG are mediated via activation of a nPKC, Ras, MEKK1, MEK3, p38{delta}-ERK1/2 signaling cascade which leads to increased activator protein 1 (AP1) and CAATT enhancer binding protein (C/EBP) transcription factor expression, increased binding of these factors to DNA, and increased gene transcription. In contrast, apigenin, a dietary flavonoid derived from plants and vegetables, and curcumin, an agent derived from turmeric, inhibit differentiation by suppressing MAPK signal transduction and reducing API transcription factor level. Curcumin also acts to enhance apoptosis, although EGCG and apigenin do not stimulate apoptosis. In addition, all of these agents inhibit keratinocyte proliferation. These findings indicate that each of these diet-derived chemopreventive agents has a profound impact on normal human keratinocyte function and that they operate via distinct and sometimes opposing mechanisms. However, all are expected to act as chemopreventive agents.« less

Posttraumatic epidermal inclusion cyst of the deep infratemporal fossa.

PubMed

Acarturk, T O; Stofman, G M

2001-01-01

The authors report a case of an epidermal inclusion cyst found in the deep infratemporal fossa 12 years after the patient sustained blunt trauma to that region. Posttraumatic epidermal inclusion cysts are rare and occur mainly in the fingers, palms, and soles. Introduction of the epidermal elements into the dermis during the trauma is thought to be the cause. This case is rare in presentation, with few reports in the English literature that describe an epidermal inclusion cyst in the deep infratemporal fossa. Review of the English literature disclosed no other cases of epidermal inclusion cyst after blunt trauma involving the deep infratemporal region.

Carbon Dioxide Metabolism in Leaf Epidermal Tissue 1

PubMed Central

Willmer, C. M.; Pallas, J. E.; Black, C. C.

1973-01-01

A number of plant species were surveyed to obtain pure leaf epidermal tissue in quantity. Commelina communis L. and Tulipa gesnariana L. (tulip) were chosen for further work. Chlorophyll a/b ratios of epidermal tissues were 2.41 and 2.45 for C. communis and tulip, respectively. Phosphoenolpyruvate carboxylase, ribulose-1,5-diphosphate carboxylase, malic enzyme, and NAD+ and NADP+ malate dehydrogenases were assayed with epidermal tissue and leaf tissue minus epidermal tissue. In both species, there was less ribulose 1,5-diphosphate than phosphoenolpyruvate carboxylase activity in epidermal tissue whether expressed on a protein or chlorophyll basis whereas the reverse was true for leaf tissue minus epidermal tissue. In both species, malic enzyme activities were higher in epidermal tissue than in the remaining leaf tissue when expressed on a protein or chlorophyll basis. In both species, NAD+ and NADP+ malate dehydrogenase activities were higher in the epidermal tissue when expressed on a chlorophyll basis; however, on a protein basis, the converse was true. Microautoradiography of C. communis epidermis and histochemical tests for keto acids suggested that CO2 fixation occurred predominantly in the guard cells. The significance and possible location of the enzymes are discussed in relation to guard cell metabolism. Images PMID:16658581

Adult epidermal Notch activity induces dermal accumulation of T cells and neural crest derivatives through upregulation of jagged 1

PubMed Central

Ambler, Carrie A.; Watt, Fiona M.

2010-01-01

Notch signalling regulates epidermal differentiation and tumour formation via non-cell autonomous mechanisms that are incompletely understood. This study shows that epidermal Notch activation via a 4-hydroxy-tamoxifen-inducible transgene caused epidermal thickening, focal detachment from the underlying dermis and hair clumping. In addition, there was dermal accumulation of T lymphocytes and stromal cells, some of which localised to the blisters at the epidermal-dermal boundary. The T cell infiltrate was responsible for hair clumping but not for other Notch phenotypes. Notch-induced stromal cells were heterogeneous, expressing markers of neural crest, melanocytes, smooth muscle and peripheral nerve. Although Slug1 expression was expanded in the epidermis, the stromal cells did not arise through epithelial-mesenchymal transition. Epidermal Notch activation resulted in upregulation of jagged 1 in both epidermis and dermis. When Notch was activated in the absence of epidermal jagged 1, jagged 1 was not upregulated in the dermis, and epidermal thickening, blister formation, accumulation of T cells and stromal cells were inhibited. Gene expression profiling revealed that epidermal Notch activation resulted in upregulation of several growth factors and cytokines, including TNFα, the expression of which was dependent on epidermal jagged 1. We conclude that jagged 1 is a key mediator of non-cell autonomous Notch signalling in skin. PMID:20940224

Arctigenin induced gallbladder cancer senescence through modulating epidermal growth factor receptor pathway.

PubMed

Zhang, Mingdi; Cai, Shizhong; Zuo, Bin; Gong, Wei; Tang, Zhaohui; Zhou, Di; Weng, Mingzhe; Qin, Yiyu; Wang, Shouhua; Liu, Jun; Ma, Fei; Quan, Zhiwei

2017-05-01

Gallbladder cancer has poor prognosis and limited therapeutic options. Arctigenin, a representative dibenzylbutyrolactone lignan, occurs in a variety of plants. However, the molecular mechanisms involved in the antitumor effect of arctigenin on gallbladder cancer have not been fully elucidated. The expression levels of epidermal growth factor receptor were examined in 100 matched pairs of gallbladder cancer tissues. A positive correlation between high epidermal growth factor receptor expression levels and poor prognosis was observed in gallbladder cancer tissues. Pharmacological inhibition or inhibition via RNA interference of epidermal growth factor receptor induced cellular senescence in gallbladder cancer cells. The antitumor effect of arctigenin on gallbladder cancer cells was primarily achieved by inducing cellular senescence. In gallbladder cancer cells treated with arctigenin, the expression level of epidermal growth factor receptor significantly decreased. The analysis of the activity of the kinases downstream of epidermal growth factor receptor revealed that the RAF-MEK-ERK signaling pathway was significantly inhibited. Furthermore, the cellular senescence induced by arctigenin could be reverted by pcDNA-epidermal growth factor receptor. Arctigenin also potently inhibited the growth of tumor xenografts, which was accompanied by the downregulation of epidermal growth factor receptor and induction of senescence. This study demonstrates arctigenin could induce cellular senescence in gallbladder cancer through the modulation of epidermal growth factor receptor pathway. These data identify epidermal growth factor receptor as a key regulator in arctigenin-induced gallbladder cancer senescence.

Measurement of transepidermal water loss in localized scleroderma.

PubMed

Ďurčanská, Veronika; Jedličková, Hana; Vašků, Vladimír

2016-05-01

Localized scleroderma (LS) is a disease characterized by fibrotic changes in the dermis. Connective tissue growth factor and transforming growth factor β2 are the main mediators of fibrogenesis; this, along with excessive connective tissue production, affects epidermal keratinocytes, and thereby contributes to the changed quality of skin barrier. The objective of this article was to study the objective measurement of the skin barrier quality in LS with transepidermal water loss (TEWL) meter. The measurements of TEWL were performed on LS plaques in all three stages of various body locations. Control measurements were made on the contralateral side of healthy skin. The difference between TEWL in LS area and the contralateral side of the healthy skin was evaluated. A higher average TEWL 7.86 g/m(2) /h (SD 5.29) was observed on LS plaques compared with the control measurements on healthy skin 6.39 g/m(2) /h (SD 2.77). TEWL average values decreased from the inflammatory stage, through the sclerotic and to the atrophic stage. The mean difference 1.301 g/m(2) /h (SD 5.16) was found between TEWL on LS plaques and on the contralateral healthy skin in 82 measurements, i.e., a higher TEWL was observed in LS. The difference was statistically significant with p = 0.0250. Although fibrogenesis in scleroderma is localized in dermis, the skin barrier changes can be detected. © 2016 Wiley Periodicals, Inc.

Micromixer Based Preparation of Functionalized Liposomes and Targeting Drug Delivery

PubMed Central

2016-01-01

We present here a specific targeting nanocarrier system by functionalization of liposomes with one new type of breast cancer targeting peptide (H6, YLFFVFER) by a micromixer with high efficiency. Antitumor drugs could be successfully delivered into human epidermal growth factor receptor 2 (HER2) positive breast cancer cells with high efficiency in both in vivo and ex vivo models. PMID:27096054

Transcript Profiling Identifies Gene Cohorts Controlled by Each Signal Regulating Trans-Differentiation of Epidermal Cells of Vicia faba Cotyledons to a Transfer Cell Phenotype

PubMed Central

Zhang, Hui-Ming; Wheeler, Simon L.; Xia, Xue; Colyvas, Kim; Offler, Christina E.; Patrick, John W.

2017-01-01

Transfer cells (TCs) support high rates of membrane transport of nutrients conferred by a plasma membrane area amplified by lining a wall labyrinth comprised of an uniform wall layer (UWL) upon which intricate wall ingrowth (WI) papillae are deposited. A signal cascade of auxin, ethylene, extracellular hydrogen peroxide (H2O2) and cytosolic Ca2+ regulates wall labyrinth assembly. To identify gene cohorts regulated by each signal, a RNA- sequencing study was undertaken using Vicia faba cotyledons. When cotyledons are placed in culture, their adaxial epidermal cells spontaneously undergo trans-differentiation to epidermal TCs (ETCs). Expressed genes encoding proteins central to wall labyrinth formation (signaling, intracellular organization, cell wall) and TC function of nutrient transport were assembled. Transcriptional profiles identified 9,742 annotated ETC-specific differentially expressed genes (DEGs; Log2fold change > 1; FDR p ≤ 0.05) of which 1,371 belonged to signaling (50%), intracellular organization (27%), cell wall (15%) and nutrient transporters (9%) functional categories. Expression levels of 941 ETC-specific DEGs were found to be sensitive to the known signals regulating ETC trans-differentiation. Significantly, signals acting alone, or in various combinations, impacted similar numbers of ETC-specific DEGs across the four functional gene categories. Amongst the signals acting alone, H2O2 exerted most influence affecting expression levels of 56% of the ETC-specific DEGs followed by Ca2+ (21%), auxin (18%) and ethylene (5%). The dominance by H2O2 was evident across all functional categories, but became more attenuated once trans-differentiation transitioned into WI papillae formation. Amongst the eleven signal combinations, H2O2/Ca2+ elicited the greatest impact across all functional categories accounting for 20% of the ETC-specific DEG cohort. The relative influence of the other signals acting alone, or in various combinations, varied across the four functional categories and two phases of wall labyrinth construction. These transcriptome data provide a powerful information platform from which to examine signal transduction pathways and how these regulate expression of genes encoding proteins engaged in intracellular organization, cell wall construction and nutrient transport. PMID:29234338

Transcript Profiling Identifies Gene Cohorts Controlled by Each Signal Regulating Trans-Differentiation of Epidermal Cells of Vicia faba Cotyledons to a Transfer Cell Phenotype.

PubMed

Zhang, Hui-Ming; Wheeler, Simon L; Xia, Xue; Colyvas, Kim; Offler, Christina E; Patrick, John W

2017-01-01

Transfer cells (TCs) support high rates of membrane transport of nutrients conferred by a plasma membrane area amplified by lining a wall labyrinth comprised of an uniform wall layer (UWL) upon which intricate wall ingrowth (WI) papillae are deposited. A signal cascade of auxin, ethylene, extracellular hydrogen peroxide (H 2 O 2 ) and cytosolic Ca 2+ regulates wall labyrinth assembly. To identify gene cohorts regulated by each signal, a RNA- sequencing study was undertaken using Vicia faba cotyledons. When cotyledons are placed in culture, their adaxial epidermal cells spontaneously undergo trans -differentiation to epidermal TCs (ETCs). Expressed genes encoding proteins central to wall labyrinth formation (signaling, intracellular organization, cell wall) and TC function of nutrient transport were assembled. Transcriptional profiles identified 9,742 annotated ETC-specific differentially expressed genes (DEGs; Log 2 fold change > 1; FDR p ≤ 0.05) of which 1,371 belonged to signaling (50%), intracellular organization (27%), cell wall (15%) and nutrient transporters (9%) functional categories. Expression levels of 941 ETC-specific DEGs were found to be sensitive to the known signals regulating ETC trans -differentiation. Significantly, signals acting alone, or in various combinations, impacted similar numbers of ETC-specific DEGs across the four functional gene categories. Amongst the signals acting alone, H 2 O 2 exerted most influence affecting expression levels of 56% of the ETC-specific DEGs followed by Ca 2+ (21%), auxin (18%) and ethylene (5%). The dominance by H 2 O 2 was evident across all functional categories, but became more attenuated once trans -differentiation transitioned into WI papillae formation. Amongst the eleven signal combinations, H 2 O 2 /Ca 2+ elicited the greatest impact across all functional categories accounting for 20% of the ETC-specific DEG cohort. The relative influence of the other signals acting alone, or in various combinations, varied across the four functional categories and two phases of wall labyrinth construction. These transcriptome data provide a powerful information platform from which to examine signal transduction pathways and how these regulate expression of genes encoding proteins engaged in intracellular organization, cell wall construction and nutrient transport.

Potential barrier classification by short-time measurement

NASA Astrophysics Data System (ADS)

Granot, Er'El; Marchewka, Avi

2006-03-01

We investigate the short-time dynamics of a delta-function potential barrier on an initially confined wave packet. There are mainly two conclusions: (A) At short times the probability density of the first particles that passed through the barrier is unaffected by it. (B) When the barrier is absorptive (i.e., its potential is imaginary) it affects the transmitted wave function at shorter times than a real potential barrier. Therefore, it is possible to distinguish between an imaginary and a real potential barrier by measuring its effect at short times only on the transmitting wave function.

SRC-mediated EGF Receptor Activation Regulates Ozone-induced Interleukin 8 Expression in Human Bronchial Epithelial Cells

EPA Science Inventory

BACKGROUND: Human exposure to ozone (03) results in pulmonary function decrements and airway inflammation. The mechanisms underlying these adverse effects remain unclear. Epidermal growth factor receptor (EGFR) plays an important role in the pathogenesis of lung inflammation. ...

Analysis of corkscrew signaling in the Drosophila epidermal growth factor receptor pathway during myogenesis.

PubMed

Johnson Hamlet, M R; Perkins, L A

2001-11-01

The Drosophila nonreceptor protein tyrosine phosphatase, Corkscrew (Csw), functions positively in multiple receptor tyrosine kinase (RTK) pathways, including signaling by the epidermal growth factor receptor (EGFR). Detailed phenotypic analyses of csw mutations have revealed that Csw activity is required in many of the same developmental processes that require EGFR function. However, it is still unclear where in the signaling hierarchy Csw functions relative to other proteins whose activities are also required downstream of the receptor. To address this issue, genetic interaction experiments were performed to place csw gene activity relative to the EGFR, spitz (spi), rhomboid (rho), daughter of sevenless (DOS), kinase-suppressor of ras (ksr), ras1, D-raf, pointed (pnt), and moleskin. We followed the EGFR-dependent formation of VA2 muscle precursor cells as a sensitive assay for these genetic interaction studies. First, we established that Csw has a positive function during mesoderm development. Second, we found that tissue-specific expression of a gain-of-function csw construct rescues loss-of-function mutations in other positive signaling genes upstream of rolled (rl)/MAPK in the EGFR pathway. Third, we were able to infer levels of EGFR signaling in various mutant backgrounds during myogenesis. This work extends previous studies of Csw during Torso and Sevenless RTK signaling to include an in-depth analysis of the role of Csw in the EGFR signaling pathway.

Analysis of corkscrew signaling in the Drosophila epidermal growth factor receptor pathway during myogenesis.

PubMed Central

Johnson Hamlet, M R; Perkins, L A

2001-01-01

The Drosophila nonreceptor protein tyrosine phosphatase, Corkscrew (Csw), functions positively in multiple receptor tyrosine kinase (RTK) pathways, including signaling by the epidermal growth factor receptor (EGFR). Detailed phenotypic analyses of csw mutations have revealed that Csw activity is required in many of the same developmental processes that require EGFR function. However, it is still unclear where in the signaling hierarchy Csw functions relative to other proteins whose activities are also required downstream of the receptor. To address this issue, genetic interaction experiments were performed to place csw gene activity relative to the EGFR, spitz (spi), rhomboid (rho), daughter of sevenless (DOS), kinase-suppressor of ras (ksr), ras1, D-raf, pointed (pnt), and moleskin. We followed the EGFR-dependent formation of VA2 muscle precursor cells as a sensitive assay for these genetic interaction studies. First, we established that Csw has a positive function during mesoderm development. Second, we found that tissue-specific expression of a gain-of-function csw construct rescues loss-of-function mutations in other positive signaling genes upstream of rolled (rl)/MAPK in the EGFR pathway. Third, we were able to infer levels of EGFR signaling in various mutant backgrounds during myogenesis. This work extends previous studies of Csw during Torso and Sevenless RTK signaling to include an in-depth analysis of the role of Csw in the EGFR signaling pathway. PMID:11729154

[Progress in epidermal stem cells].

PubMed

Wang, Li-Juan; Wang, You-Liang; Yang, Xiao

2010-03-01

Mammalian skin epidermis contains different epidermal stem cell pools which contribute to the homeostasis and repair of skin epithelium. Epidermal stem cells possess two essential features common to all stem cells: self-renewal and differentiation. Disturbing the balance between self-renewal and differentiation of epidermal stem cell often causes tumors or other skin diseases. Epidermal stem cell niches provide a special microenvironment that maintains a balance of stem cell quiescence and activity. This review primarily concentrates on the following points of the epidermal stem cells: the existing evidences, the self-renewal and differentiation, the division pattern, the signal pathways regulating self-renewal and differentiation, and the microenvironment (niche) and macroenvironment maintaining the homeostasis of stem cells.

Aquaporins in Clinical Medicine

PubMed Central

Verkman, A.S.

2012-01-01

The aquaporins are a family of membrane water channels, some of which also transport glycerol. They are involved in a wide range of physiological functions (including water/salt homeostasis, exocrine fluid secretion, and epidermal hydration) and human diseases (including glaucoma, cancer, epilepsy, and obesity). At the cellular level, aquaporin-mediated osmotic water transport across cell plasma membranes facilitates transepithelial fluid transport, cell migration, and neuroexcitation; aquaporin-mediated glycerol transport regulates cell proliferation, adipocyte metabolism, and epidermal water retention. Genetic diseases caused by loss-of-function mutations in aquaporins include nephrogenic diabetes insipidus and congenital cataracts. The neuroinflammatory demyelinating disease neuromyelitis optica is marked by pathogenic autoantibodies against astrocyte water channel aquaporin-4. There remain broad opportunities for the development of aquaporin-based diagnostics and therapeutics. Disease-relevant aquaporin polymorphisms are beginning to be explored. There is great promise in the development of small-molecule aquaporin modulators for therapy of some types of refractory edema, brain swelling, neuroinflammation, glaucoma, epilepsy, cancer, pain, and obesity. PMID:22248325

Penetration of UV-A, UV-B, blue, and red light into leaf tissues of pecan measured by a fiber optic microprobe system

NASA Astrophysics Data System (ADS)

Qi, Yadong; Bai, Shuju; Vogelmann, Thomas C.; Heisler, Gordon M.

2003-11-01

The depth of light penetration from the adaxial surfaces of the mature leaves of pecan (Carya illinoensis) was measured using a fiber optic microprobe system at four wavelengths: UV-B (310nm), UV-A (360 nm), blue light (430nm), and red light (680nm). The average thickness of the leaf adaxial epidermal layer was 15um and the total leaf thickness was 219um. The patterns of the light attenuation by the leaf tissues exhibited strong wavelength dependence. The leaf adaxial epidermal layer was chiefly responsible for absorbing the UV-A UV-B radiation. About 98% of 310 nm light was steeply attenuated within the first 5 um of the adaxial epidermis; thus, very little UV-B radiation was transmitted to the mesophyll tissues where contain photosynthetically sensitive sites. The adaxial epidermis also attenuated 96% of the UV-A radiation. In contrast, the blue and red light penetrated much deeper and was gradually attenutated by the leaves. The mesophyll tissues attenuated 17% of the blue light and 42% of the red light, which were available for photosynthesis use. Since the epidermal layer absorbed nearly all UV-B light, it acted as an effective filter screening out the harmful radiation and protecting photosynthetically sensitive tissues from the UV-B damage. Therefore, the epidermal function of the UV-B screening effectiveness can be regarded as one of the UV-B protection mechanisms in pecan.

Identification of heparin-binding EGF-like growth factor as a target in intercellular regulation of epidermal basal cell growth by suprabasal retinoic acid receptors.

PubMed Central

Xiao, J H; Feng, X; Di, W; Peng, Z H; Li, L A; Chambon, P; Voorhees, J J

1999-01-01

The role of retinoic acid receptors (RARs) in intercellular regulation of cell growth was assessed by targeting a dominant-negative RARalpha mutant (dnRARalpha) to differentiated suprabasal cells of mouse epidermis. dnRARalpha lacks transcriptional activation but not DNA-binding and receptor dimerization functions. Analysis of transgenic mice revealed that dnRARalpha dose-dependently impaired induction of basal cell proliferation and epidermal hyperplasia by all-trans RA (tRA). dnRARalpha formed heterodimers with endogenous retinoid X receptor-alpha (RXRalpha) over RA response elements in competition with remaining endogenous RARgamma-RXRalpha heterodimers, and dose-dependently impaired retinoid-dependent gene transcription. To identify genes regulated by retinoid receptors and involved in cell growth control, we analyzed the retinoid effects on expression of the epidermal growth factor (EGF) receptor, EGF, transforming growth factor-alpha, heparin-binding EGF-like growth factor (HB-EGF) and amphiregulin genes. In normal epidermis, tRA rapidly and selectively induced expression of HB-EGF but not the others. This induction occurred exclusively in suprabasal cells. In transgenic epidermis, dnRARalpha dose-dependently inhibited tRA induction of suprabasal HB-EGF and subsequent basal cell hyperproliferation. Together, our observations suggest that retinoid receptor heterodimers located in differentiated suprabasal cells mediate retinoid induction of HB-EGF, which in turn stimulates basal cell growth via intercellular signaling. These events may underlie retinoid action in epidermal regeneration during wound healing. PMID:10075925

The WEREWOLF MYB protein directly regulates CAPRICE transcription during cell fate specification in the Arabidopsis root epidermis.

PubMed

Ryu, Kook Hui; Kang, Yeon Hee; Park, Young-hwan; Hwang, Ildoo; Schiefelbein, John; Lee, Myeong Min

2005-11-01

The Arabidopsis root epidermis is composed of two types of cells, hair cells and non-hair cells, and their fate is determined in a position-dependent manner. WEREWOLF (WER), a R2R3 MYB protein, has been shown genetically to function as a master regulator to control both of the epidermal cell fates. To directly test the proposed role of WER in this system, we examined its subcellular localization and defined its transcriptional activation properties. We show that a WER-GFP fusion protein is functional and accumulates in the nucleus of the N-position cells in the Arabidopsis root epidermis, as expected for a transcriptional regulator. We also find that a modified WER protein with a strong activation domain (WER-VP16) promotes the formation of both epidermal cell types, supporting the view that WER specifies both cell fates. In addition, we used the glucocorticoid receptor (GR) inducible system to show that CPC transcription is regulated directly by WER. Using EMSA, we found two WER-binding sites (WBSs; WBSI and WBSII) in the CPC promoter. WER-WBSI binding was confirmed in vivo using the yeast one-hybrid assay. Binding between the WER protein and both WBSs (WBSI and WBSII), and the importance of the two WBSs in CPC promoter activity were confirmed in Arabidopsis. These results provide experimental support for the proposed role of WER as an activator of gene transcription during the specification of both epidermal cell fates.

DNMT1 maintains progenitor function in self-renewing somatic tissue.

PubMed

Sen, George L; Reuter, Jason A; Webster, Daniel E; Zhu, Lilly; Khavari, Paul A

2010-01-28

Progenitor cells maintain self-renewing tissues throughout life by sustaining their capacity for proliferation while suppressing cell cycle exit and terminal differentiation. DNA methylation provides a potential epigenetic mechanism for the cellular memory needed to preserve the somatic progenitor state through repeated cell divisions. DNA methyltransferase 1 (DNMT1) maintains DNA methylation patterns after cellular replication. Although dispensable for embryonic stem cell maintenance, the role for DNMT1 in maintaining the progenitor state in constantly replenished somatic tissues, such as mammalian epidermis, is unclear. Here we show that DNMT1 is essential for epidermal progenitor cell function. DNMT1 protein was found enriched in undifferentiated cells, where it was required to retain proliferative stamina and suppress differentiation. In tissue, DNMT1 depletion led to exit from the progenitor cell compartment, premature differentiation and eventual tissue loss. Genome-wide analysis showed that a significant portion of epidermal differentiation gene promoters were methylated in self-renewing conditions but were subsequently demethylated during differentiation. Furthermore, UHRF1 (refs 9, 10), a component of the DNA methylation machinery that targets DNMT1 to hemi-methylated DNA, is also necessary to suppress premature differentiation and sustain proliferation. In contrast, Gadd45A and B, which promote active DNA demethylation, are required for full epidermal differentiation gene induction. These data demonstrate that proteins involved in the dynamic regulation of DNA methylation patterns are required for progenitor maintenance and self-renewal in mammalian somatic tissue.

Esterase Activity and Intracellular Localization in Reconstructed Human Epidermal Cultured Skin Models.

PubMed

Tokudome, Yoshihiro; Katayanagi, Mishina; Hashimoto, Fumie

2015-06-01

Reconstructed human epidermal culture skin models have been developed for cosmetic and pharmaceutical research. This study evaluated the total and carboxyl esterase activities (i.e., Km and Vmax , respectively) and localization in two reconstructed human epidermal culture skin models (LabCyte EPI-MODEL [Japan Tissue Engineering] and EpiDerm [MatTek/Kurabo]). The usefulness of the reconstruction cultured epidermis was also verified by comparison with human and rat epidermis. Homogenized epidermal samples were fractioned by centrifugation. p-nitrophenyl acetate and 4-methylumbelliferyl acetate were used as substrates of total esterase and carboxyl esterase, respectively. Total and carboxyl esterase activities were present in the reconstructed human epidermal culture skin models and were localized in the cytosol. Moreover, the activities and localization were the same as those in human and rat epidermis. LabCyte EPI-MODEL and EpiDerm are potentially useful for esterase activity prediction in human epidermis.

Esterase Activity and Intracellular Localization in Reconstructed Human Epidermal Cultured Skin Models

PubMed Central

Katayanagi, Mishina; Hashimoto, Fumie

2015-01-01

Background Reconstructed human epidermal culture skin models have been developed for cosmetic and pharmaceutical research. Objective This study evaluated the total and carboxyl esterase activities (i.e., Km and Vmax, respectively) and localization in two reconstructed human epidermal culture skin models (LabCyte EPI-MODEL [Japan Tissue Engineering] and EpiDerm [MatTek/Kurabo]). The usefulness of the reconstruction cultured epidermis was also verified by comparison with human and rat epidermis. Methods Homogenized epidermal samples were fractioned by centrifugation. p-nitrophenyl acetate and 4-methylumbelliferyl acetate were used as substrates of total esterase and carboxyl esterase, respectively. Results Total and carboxyl esterase activities were present in the reconstructed human epidermal culture skin models and were localized in the cytosol. Moreover, the activities and localization were the same as those in human and rat epidermis. Conclusion LabCyte EPI-MODEL and EpiDerm are potentially useful for esterase activity prediction in human epidermis. PMID:26082583

Skin problems and EGFR-tyrosine kinase inhibitor

PubMed Central

Kozuki, Toshiyuki

2016-01-01

Epidermal growth factor receptor inhibition is a good target for the treatment of lung, colon, pancreatic and head and neck cancers. Epidermal growth factor receptor-tyrosine kinase inhibitor was first approved for the treatment of advanced lung cancer in 2002. Epidermal growth factor receptor-tyrosine kinase inhibitor plays an essential role in the treatment of cancer, especially for patients harbouring epidermal growth factor receptor activating mutation. Hence, skin toxicity is the most concerning issue for the epidermal growth factor receptor-tyrosine kinase inhibitor treatment. Skin toxicity is bothersome and sometimes affects the quality of life and treatment compliance. Thus, it is important for physicians to understand the background and how to manage epidermal growth factor receptor-tyrosine kinase inhibitor-associated skin toxicity. Here, the author reviewed the mechanism and upfront preventive and reactive treatments for epidermal growth factor receptor inhibitor-associated skin toxicities. PMID:26826719

Epidermal culture and grafting. A brief review.

PubMed

Muehleman, C; Wise, R D

1993-08-01

In summary, technological advances in culturing epidermis for the purpose of grafting allow this approach in the treatment of cutaneous wounds. Certainly, full- and split-thickness autografts offer immediate availability and permanent wound coverage, but they also involve a large, painful donor site. Cultured epidermal autografts can provide permanent wound coverage, but the delay required for cultivation of confluent sheets of keratinocytes makes them somewhat less desirable. Both allografts and cultured allografts, on the other hand, are available for immediate use, but the possibility of infectious disease transmission may be a concern. In any case, all types of skin grafts function as biological dressings that promote the proliferation of the host's epidermis and, thus, facilitate the ability of the patient's skin to repair itself.

Epidermal stem cells: location, potential and contribution to cancer.

PubMed

Ambler, C A; Määttä, A

2009-01-01

Epidermal stem cells have been classically characterized as slow-cycling, long-lived cells that reside in discrete niches in the skin. Gene expression studies of niche-resident cells have revealed a number of stem cell markers and regulators, including the Wnt/beta-catenin, Notch, p63, c-Myc and Hedgehog pathways. A new study challenges the traditional developmental paradigm of slow-cycling stem cells and rapid-cycling transit amplifying cells in some epidermal regions, and there is mounting evidence to suggest that multi-lineage epidermal progenitors can be isolated from highly proliferative, non-niche regions. Whether there is a unique microenvironment surrounding these progenitors remains to be determined. Interestingly, cancer stem cells derived from epidermal tumours exist independent of the classic skin stem cell niche, yet also have stem cell properties, including multi-lineage differentiation. This review summarizes recent studies identifying the location and regulators of mouse and human epidermal stem cells and highlights the strategies used to identify cancer stem cells, including expression of normal epidermal stem cell markers, expression of cancer stem cell markers identified in other epidermal tumours and characterization of side-population tumour cells.

Increased matriptase zymogen activation in inflammatory skin disorders

PubMed Central

Chen, Cheng-Jueng; Wu, Bai-Yao; Tsao, Pai-In; Chen, Chi-Yung; Wu, Mei-Hsuan; Chan, Yee Lam E.; Lee, Herng-Sheng; Johnson, Michael D.; Eckert, Richard L.; Chen, Ya-Wen; Chou, Fengpai; Lin, Chen-Yong

2011-01-01

Matriptase, a type 2 transmembrane serine protease, and its inhibitor hepatocyte growth factor activator inhibitor (HAI)-1 are required for normal epidermal barrier function, and matriptase activity is tightly regulated during this process. We therefore hypothesized that this protease system might be deregulated in skin disease. To test this, we examined the level and activation state of matriptase in examples of 23 human skin disorders. We first examined matriptase and HAI-1 protein distribution in normal epidermis. Matriptase was detected at high levels at cell-cell junctions in the basal layer and spinous layers but was present at minimal levels in the granular layer. HAI-1 was distributed in a similar pattern, except that high-level expression was retained in the granular layer. This pattern of expression was retained in most skin disorders. We next examined the distribution of activated matriptase. Although activated matriptase is not detected in normal epidermis, a dramatic increase is seen in keratinocytes at the site of inflammation in 16 different skin diseases. To gain further evidence that activation is associated with inflammatory stimuli, we challenged HaCaT cells with acidic pH or H2O2 and observed matriptase activation. These findings suggest that inflammation-associated reactive oxygen species and tissue acidity may enhance matriptase activation in some skin diseases. PMID:21123732

Sun-induced changes of stratum corneum hydration vary with age and gender in a normal Chinese population.

PubMed

Liu, Zhili; Song, Shunpeng; Luo, Wenhai; Elias, Peter M; Man, Mao-Qiang

2012-02-01

Previous studies have demonstrated that sun-induced alteration of epidermal permeability barrier function varies with gender and age. In the present study, we assess the stratum corneum (SC) hydration in sun-exposed males and females. A total of 168 subjects (84 males and 84 females) aged 19-75 years were enrolled. A multifunctional skin physiology monitor was used to measure SC hydration. In comparison with non-sun exposure, sun exposure does not cause a significant change in SC hydration in either young males or young females, whereas in aged females, a significant reduction of SC hydration is seen on the forehead and the dorsal hand of sun-exposed subjects. SC hydration on the canthus of both aged males and aged females is significantly lower than that of young subjects. Additionally, SC hydration on the dorsal hand of aged females is also significantly lower as compared with young females. Sun-induced reduction of SC hydration is more evident on the dorsal hand of aged females than that of males (P<0.001). Moreover, the SC rehydration capacity is significantly lower in sun-exposed aged females than in age-matched males. These results demonstrated that sun-induced changes of the SC hydration property vary with age and gender. © 2011 John Wiley & Sons A/S.

Graphene-induced apoptosis in lung epithelial cells through EGFR

NASA Astrophysics Data System (ADS)

Tsai, Shih-Ming; Bangalore, Preeti; Chen, Eric Y.; Lu, David; Chiu, Meng-Hsuen; Suh, Andrew; Gehring, Matthew; Cangco, John P.; Garcia, Santiago G.; Chin, Wei-Chun

2017-07-01

Expanding interest in nanotechnology applied to electronic and biomedical fields has led to fast-growing development of various nanomaterials. Graphene is a single-atom thick, two-dimensional sheet of hexagonally arranged carbon atoms with unique physical and chemical properties. Recently, graphene has been used in many studies on electronics, photonics, composite materials, energy generation and storage, sensors, and biomedicine. However, the current health risk assessment for graphene has been relatively limited and inconclusive. This study evaluated the toxicity effects of graphene on the airway epithelial cell line BEAS-2B, which represents the first barrier of the human body to interact with airborne graphene particles. Our result showed that graphene can induce the cellular Ca2+ by phospholipase C (PLC) associated pathway by activating epidermal growth factor receptor (EGFR). Subsequently, inositol 1,4,5-triphosphate (IP3) receptors activate the release of Ca2+ from the endoplasmic reticulum (ER) Ca2+ stores. Those Ca2+ signals further trigger the calcium-regulated apoptosis in the cell. Furthermore, the stimulation can cause EGFR upregulation, which have been demonstrated to associate with diseases such as lung cancer, chronic obstructive pulmonary disease (COPD), and cardiovascular diseases. This study highlights the additional health risk considering that it can function as a contributing factor for other respiratory diseases.

Glyphosate-induced stiffening of HaCaT keratinocytes, a Peak Force Tapping study on living cells.

PubMed

Heu, Celine; Berquand, Alexandre; Elie-Caille, Celine; Nicod, Laurence

2012-04-01

The skin is the first physiological barrier, with a complex constitution, that provides defensive functions against multiple physical and chemical aggressions. Glyphosate is an extensively used herbicide that has been shown to increase the risk of cancer. Moreover there is increasing evidence suggesting that the mechanical phenotype plays an important role in malignant transformation. Atomic force microscopy (AFM) has emerged within the last decade as a powerful tool for providing a nanometer-scale resolution imaging of biological samples. Peak Force Tapping (PFT) is a newly released AFM-based investigation technique allowing extraction of chemical and mechanical properties from a wide range of samples at a relatively high speed and a high resolution. The present work uses the PFT technology to investigate HaCaT keratinocytes, a human epidermal cell line, and offers an original approach to study chemically-induced changes in the cellular mechanical properties under near-physiological conditions. These experiments indicate glyphosate induces cell membrane stiffening, and the appearance of cytoskeleton structures at a subcellular level, for low cytotoxic concentrations whereas cells exposed to IC50 (inhibitory concentration 50%) treatment exhibit control-like mechanical behavior despite obvious membrane damages. Quercetin, a well-known antioxidant, reverses the glyphosate-induced mechanical phenotype. Copyright © 2012 Elsevier Inc. All rights reserved.

Expressions of TRPVs in the cholesteatoma epithelium.

PubMed

Do, Ba Hung; Koizumi, Hiroki; Ohbuchi, Toyoaki; Kawaguchi, Rintaro; Suzuki, Hideaki

2017-10-01

We have recently proposed a hypothesis that acid leakage through the cholesteatoma epithelium mediates bone resorption in middle ear cholesteatoma. In the present study, we investigated the expressions of transient receptor potential vanilloid (TRPV) channels, which have been shown to play roles in the regulation of epidermal barrier function, in the cholesteatoma epithelium in comparison with the normal skin. Cholesteatoma epithelium and postauricular skin were collected from 17 patients with primary acquired middle ear cholesteatoma who underwent tympanomastoidectomy. Expressions of TRPV1, TRPV3, TRPV4, and TRPV6 were explored by fluorescence immunohistochemistry and quantitative reverse transcription-polymerase chain reaction (qRT-PCR). TRPV1, TRPV3, TRPV4, and TRPV6 mRNAs were all detected by qRT-PCR both in the skin and cholesteatoma tissue. Immunohistochemical staining showed that TRPV1 and TRPV3 were positive in the viable cell layers of the epidermis of the skin, and only TRPV3 was positive in those of the cholesteatoma epithelium. The immunoreactivity for TRPV3 was significantly weaker in cholesteatoma than in the skin. The lower expression of TRPV3 in cholesteatoma may be one of the mechanisms underlying the increased permeability of this tissue. On the other hand, TRPV1, TRPV4, and TRPV6 are unlikely to be involved in the regulation of epithelial permeability in cholesteatoma.

An Automated and Minimally Invasive Tool for Generating Autologous Viable Epidermal Micrografts

PubMed Central

Osborne, Sandra N.; Schmidt, Marisa A.; Harper, John R.

2016-01-01

ABSTRACT OBJECTIVE: A new epidermal harvesting tool (CelluTome; Kinetic Concepts, Inc, San Antonio, Texas) created epidermal micrografts with minimal donor site damage, increased expansion ratios, and did not require the use of an operating room. The tool, which applies both heat and suction concurrently to normal skin, was used to produce epidermal micrografts that were assessed for uniform viability, donor-site healing, and discomfort during and after the epidermal harvesting procedure. DESIGN: This study was a prospective, noncomparative institutional review board–approved healthy human study to assess epidermal graft viability, donor-site morbidity, and patient experience. SETTING: These studies were conducted at the multispecialty research facility, Clinical Trials of Texas, Inc, San Antonio. PATIENTS: The participants were 15 healthy human volunteers. RESULTS: The average viability of epidermal micrografts was 99.5%. Skin assessment determined that 76% to 100% of the area of all donor sites was the same in appearance as the surrounding skin within 14 days after epidermal harvest. A mean pain of 1.3 (on a scale of 1 to 5) was reported throughout the harvesting process. CONCLUSIONS: Use of this automated, minimally invasive harvesting system provided a simple, low-cost method of producing uniformly viable autologous epidermal micrografts with minimal patient discomfort and superficial donor-site wound healing within 2 weeks. PMID:26765157

An Automated and Minimally Invasive Tool for Generating Autologous Viable Epidermal Micrografts.

PubMed

Osborne, Sandra N; Schmidt, Marisa A; Harper, John R

2016-02-01

A new epidermal harvesting tool (CelluTome; Kinetic Concepts, Inc, San Antonio, Texas) created epidermal micrografts with minimal donor site damage, increased expansion ratios, and did not require the use of an operating room. The tool, which applies both heat and suction concurrently to normal skin, was used to produce epidermal micrografts that were assessed for uniform viability, donor-site healing, and discomfort during and after the epidermal harvesting procedure. This study was a prospective, noncomparative institutional review board-approved healthy human study to assess epidermal graft viability, donor-site morbidity, and patient experience. These studies were conducted at the multispecialty research facility, Clinical Trials of Texas, Inc, San Antonio. The participants were 15 healthy human volunteers. The average viability of epidermal micrografts was 99.5%. Skin assessment determined that 76% to 100% of the area of all donor sites was the same in appearance as the surrounding skin within 14 days after epidermal harvest. A mean pain of 1.3 (on a scale of 1 to 5) was reported throughout the harvesting process. Use of this automated, minimally invasive harvesting system provided a simple, low-cost method of producing uniformly viable autologous epidermal micrografts with minimal patient discomfort and superficial donor-site wound healing within 2 weeks.

Seasonal changes in gastric mucosal factors associated with peptic ulcer bleeding.

PubMed

Yuan, Xiao-Gang; Xie, Chuan; Chen, Jiang; Xie, Yong; Zhang, Kun-He; Lu, Nong-Hua

2015-01-01

A close association has been established between climate and peptic ulcer bleeding (PUB). The incidence of PUB in cold climates is significantly higher than that in hot climates. In this study, gastric mucosal damage and its barrier function (through associated barrier factors) in extreme climate conditions were examined to investigate the pathogenesis of PUB in extreme cold climates. Gastric juice and biopsy specimens were collected from 176 patients with peptic ulcer. Conventional hematoxylin and eosin staining was used to exclude malignant ulcers. Helicobacter pylori infections were detected by modified Giemsa staining. pH values of the gastric juice samples were obtained on-site by precise pH dipstick readings. The protein expression levels of heat shock protein (HSP) 70, occludin, nitric oxide synthase (NOS), epidermal growth factor (EGF) and EGF receptor (EGFR) in the gastric mucosa were detected by immunohistochemistry. No significant differences were identified between the high and low bleeding risk groups in the rates of H. pylori infection and the pH values of the gastric juices in the extreme hot or cold climates. Furthermore, no statistically significant differences were identified in the protein expression levels of occludin, NOS, EGF and EGFR between the high and low bleeding risk groups. In the extreme cold climate, the expression of HSP70 and the mucus thickness of the gastric antrum in the high bleeding risk group were significantly lower than those in the low bleeding risk group. The protein expression levels of occludin, HSP70, NOS and EGFR in the extreme cold climate were significantly lower than those in the extreme hot climate, whereas the gastric acid secretion was significantly higher in the extreme cold climate than that in the extreme hot climate. In conclusion, low expression of HSP70 in the gastric mucosa and reduced gastric mucus thickness may play key roles in the mechanism of PUB in extreme cold climates. The significant decrease in barrier factors and increase in damage in extreme cold climates may be associated with the seasonal pattern of peptic ulcers.

Seasonal changes in gastric mucosal factors associated with peptic ulcer bleeding

PubMed Central

YUAN, XIAO-GANG; XIE, CHUAN; CHEN, JIANG; XIE, YONG; ZHANG, KUN-HE; LU, NONG-HUA

2015-01-01

A close association has been established between climate and peptic ulcer bleeding (PUB). The incidence of PUB in cold climates is significantly higher than that in hot climates. In this study, gastric mucosal damage and its barrier function (through associated barrier factors) in extreme climate conditions were examined to investigate the pathogenesis of PUB in extreme cold climates. Gastric juice and biopsy specimens were collected from 176 patients with peptic ulcer. Conventional hematoxylin and eosin staining was used to exclude malignant ulcers. Helicobacter pylori infections were detected by modified Giemsa staining. pH values of the gastric juice samples were obtained on-site by precise pH dipstick readings. The protein expression levels of heat shock protein (HSP) 70, occludin, nitric oxide synthase (NOS), epidermal growth factor (EGF) and EGF receptor (EGFR) in the gastric mucosa were detected by immunohistochemistry. No significant differences were identified between the high and low bleeding risk groups in the rates of H. pylori infection and the pH values of the gastric juices in the extreme hot or cold climates. Furthermore, no statistically significant differences were identified in the protein expression levels of occludin, NOS, EGF and EGFR between the high and low bleeding risk groups. In the extreme cold climate, the expression of HSP70 and the mucus thickness of the gastric antrum in the high bleeding risk group were significantly lower than those in the low bleeding risk group. The protein expression levels of occludin, HSP70, NOS and EGFR in the extreme cold climate were significantly lower than those in the extreme hot climate, whereas the gastric acid secretion was significantly higher in the extreme cold climate than that in the extreme hot climate. In conclusion, low expression of HSP70 in the gastric mucosa and reduced gastric mucus thickness may play key roles in the mechanism of PUB in extreme cold climates. The significant decrease in barrier factors and increase in damage in extreme cold climates may be associated with the seasonal pattern of peptic ulcers. PMID:25452787

Delayed Cutaneous Wound Healing and Aberrant Expression of Hair Follicle Stem Cell Markers in Mice Selectively Lacking Ctip2 in Epidermis

PubMed Central

Bajaj, Gaurav; Guha, Gunjan; Wang, Zhixing; Jang, Hyo-Sang; Leid, Mark; Indra, Arup Kumar; Ganguli-Indra, Gitali

2012-01-01

Background COUP-TF interacting protein 2 [(Ctip2), also known as Bcl11b] is an important regulator of skin homeostasis, and is overexpressed in head and neck cancer. Ctip2ep−/− mice, selectively ablated for Ctip2 in epidermal keratinocytes, exhibited impaired terminal differentiation and delayed epidermal permeability barrier (EPB) establishment during development, similar to what was observed in Ctip2 null (Ctip2−/−) mice. Considering that as an important role of Ctip2, and the fact that molecular networks which underlie cancer progression partially overlap with those responsible for tissue remodeling, we sought to determine the role of Ctip2 during cutaneous wound healing. Methodology/Principal Findings Full thickness excisional wound healing experiments were performed on Ctip2L2/L2 and Ctip2ep−/− animals per time point and used for harvesting samples for histology, immunohistochemistry (IHC) and immunoblotting. Results demonstrated inherent defects in proliferation and migration of Ctip2 lacking keratinocytes during re-epithelialization. Mutant mice exhibited reduced epidermal proliferation, delayed keratinocyte activation, altered cell-cell adhesion and impaired ECM development. Post wounding, Ctip2ep−/− mice wounds displayed lack of E-Cadherin suppression in the migratory tongue, insufficient expression of alpha smooth muscle actin (alpha SMA) in the dermis, and robust induction of K8. Importantly, dysregulated expression of several hair follicle (HF) stem cell markers such as K15, NFATc1, CD133, CD34 and Lrig1 was observed in mutant skin during wound repair. Conclusions/Significance Results confirm a cell autonomous role of keratinocytic Ctip2 to modulate cell migration, proliferation and/or differentiation, and to maintain HF stem cells during cutaneous wounding. Furthermore, Ctip2 in a non-cell autonomous manner regulated granulation tissue formation and tissue contraction during wound closure. PMID:22383956

Three-dimensional biomimetic vascular model reveals a RhoA, Rac1, and N-cadherin balance in mural cell-endothelial cell-regulated barrier function.

PubMed

Alimperti, Stella; Mirabella, Teodelinda; Bajaj, Varnica; Polacheck, William; Pirone, Dana M; Duffield, Jeremy; Eyckmans, Jeroen; Assoian, Richard K; Chen, Christopher S

2017-08-15

The integrity of the endothelial barrier between circulating blood and tissue is important for blood vessel function and, ultimately, for organ homeostasis. Here, we developed a vessel-on-a-chip with perfused endothelialized channels lined with human bone marrow stromal cells, which adopt a mural cell-like phenotype that recapitulates barrier function of the vasculature. In this model, barrier function is compromised upon exposure to inflammatory factors such as LPS, thrombin, and TNFα, as has been observed in vivo. Interestingly, we observed a rapid physical withdrawal of mural cells from the endothelium that was accompanied by an inhibition of endogenous Rac1 activity and increase in RhoA activity in the mural cells themselves upon inflammation. Using a system to chemically induce activity in exogenously expressed Rac1 or RhoA within minutes of stimulation, we demonstrated RhoA activation induced loss of mural cell coverage on the endothelium and reduced endothelial barrier function, and this effect was abrogated when Rac1 was simultaneously activated. We further showed that N -cadherin expression in mural cells plays a key role in barrier function, as CRISPR-mediated knockout of N -cadherin in the mural cells led to loss of barrier function, and overexpression of N -cadherin in CHO cells promoted barrier function. In summary, this bicellular model demonstrates the continuous and rapid modulation of adhesive interactions between endothelial and mural cells and its impact on vascular barrier function and highlights an in vitro platform to study the biology of perivascular-endothelial interactions.

Oral supplementation of Lithospermum erythrorhizon prevents the development of atopic dermatitis with reducing ceramide degradation in the epidermis of NC/Nga mice.

PubMed

Kim, JungMin; Kim, YoungRan; Seo, DaeBang; Kim, SungHan; Lee, SangJun; Cho, Yunhi

2009-09-01

Lithospermum erythrorhizon Sieb. et Zucc. (LE) is widely used in the treatment of abnormal skin conditions, but its systemic efficacy, especially in atopic dermatitis (AD), is not clear. To examine the systemic efficacy of LE on the clinical manifestation of AD-like skin lesions, NC/Nga mice, a murine model of AD, were fed a control diet (group CA: atopic control) or a diet with a 70% ethanol extract from 5% LE (group LE) for 10 weeks. In group LE, the clinical manifestation of AD-like skin lesions was prevented as the level of serum IgE, epidermal hyperproliferation, and the number and duration of scratching episodes, which were greater in group CA, were significantly reduced to a similar level of the normal control group of BALB/c mice (group C). In addition, the level of ceramides, the major lipid maintaining the epidermal barrier, in the epidermis of group LE was increased, and was inversely associated with a decreased protein level of ceramidase, an enzyme of ceramide degradation. However, the mRNA and the protein levels of serine palmitoyl transferase (enzyme for de novo ceramide synthesis) in groups C, CA and LE did not differ. It was demonstrated that oral supplementation with LE extract prevented the development of atopic dermatitis with reducing ceramide degradation coupled with a low expression of ceramidase protein.

Epidermal cyst mimicking incision line metastasis.

PubMed

Gündoğdu, Ramazan; Ayhan, Erhan; Çolak, Tahsin

2017-01-01

Epidermal cysts are cystic tumors lined with keratinized squamous layer and filled with keratin debris. Epidermal cysts may develop by implantation of surface epidermal layer into the dermis or subcutaneous tissue after trauma or surgical procedures. Cervix cancer spreads either directly or via the vascular and lymphatic systems. Distant skin metastasis of endometrium or cervix cancer is very rare. In this case report, a patient who had a history of cervix cancer operation 11 years ago and presented with a mass that mimicked incision line metastasis and was histopathologically diagnosed with epidermal cyst is presented.

Epidermal cyst mimicking incision line metastasis

PubMed Central

Gündoğdu, Ramazan; Ayhan, Erhan; Çolak, Tahsin

2017-01-01

Epidermal cysts are cystic tumors lined with keratinized squamous layer and filled with keratin debris. Epidermal cysts may develop by implantation of surface epidermal layer into the dermis or subcutaneous tissue after trauma or surgical procedures. Cervix cancer spreads either directly or via the vascular and lymphatic systems. Distant skin metastasis of endometrium or cervix cancer is very rare. In this case report, a patient who had a history of cervix cancer operation 11 years ago and presented with a mass that mimicked incision line metastasis and was histopathologically diagnosed with epidermal cyst is presented. PMID:28740968

Two Cases of Giant Epidermal Cyst Occurring in the Neck

PubMed Central

Kang, Sang-Gue; Kim, Chul-Han; Cho, Hong-Ki; Park, Mi-Youn; Lee, Yoon-Jin

2011-01-01

Epidermal cysts are the most common cysts of the skin. Aconventional epidermal cyst rarely reaches a size of more than 5 cm in diameter. We report on two cases of giant epidermal cyst occurring in the neck. One patient had a cyst measuring 12×9×9 cm and the other patient had a non-pulsatile, dome-shaped lesion in the neck, which measured 6×5×3 cm. The lesions were totally excised. Histopathologically, both were confirmed as giant epidermal cysts. PMID:22028561

Ischemia-reperfusion impairs blood-brain barrier function and alters tight junction protein expression in the ovine fetus.

PubMed

Chen, X; Threlkeld, S W; Cummings, E E; Juan, I; Makeyev, O; Besio, W G; Gaitanis, J; Banks, W A; Sadowska, G B; Stonestreet, B S

2012-12-13

The blood-brain barrier is a restrictive interface between the brain parenchyma and the intravascular compartment. Tight junctions contribute to the integrity of the blood-brain barrier. Hypoxic-ischemic damage to the blood-brain barrier could be an important component of fetal brain injury. We hypothesized that increases in blood-brain barrier permeability after ischemia depend upon the duration of reperfusion and that decreases in tight junction proteins are associated with the ischemia-related impairment in blood-brain barrier function in the fetus. Blood-brain barrier function was quantified with the blood-to-brain transfer constant (K(i)) and tight junction proteins by Western immunoblot in fetal sheep at 127 days of gestation without ischemia, and 4, 24, or 48 h after ischemia. The largest increase in K(i) (P<0.05) was 4 h after ischemia. Occludin and claudin-5 expressions decreased at 4 h, but returned toward control levels 24 and 48 h after ischemia. Zonula occludens-1 and -2 decreased after ischemia. Inverse correlations between K(i) and tight junction proteins suggest that the decreases in tight junction proteins contribute to impaired blood-brain barrier function after ischemia. We conclude that impaired blood-brain barrier function is an important component of hypoxic-ischemic brain injury in the fetus, and that increases in quantitatively measured barrier permeability (K(i)) change as a function of the duration of reperfusion after ischemia. The largest increase in permeability occurs 4 h after ischemia and blood-brain barrier function improves early after injury because the blood-brain barrier is less permeable 24 and 48 than 4 h after ischemia. Changes in the tight junction molecular composition are associated with increases in blood-brain barrier permeability after ischemia. Copyright © 2012 IBRO. Published by Elsevier Ltd. All rights reserved.

A Numerical Comparison of Barrier and Modified Barrier Methods for Large-Scale Bound-Constrained Optimization

NASA Technical Reports Server (NTRS)

Nash, Stephen G.; Polyak, R.; Sofer, Ariela

1994-01-01

When a classical barrier method is applied to the solution of a nonlinear programming problem with inequality constraints, the Hessian matrix of the barrier function becomes increasingly ill-conditioned as the solution is approached. As a result, it may be desirable to consider alternative numerical algorithms. We compare the performance of two methods motivated by barrier functions. The first is a stabilized form of the classical barrier method, where a numerically stable approximation to the Newton direction is used when the barrier parameter is small. The second is a modified barrier method where a barrier function is applied to a shifted form of the problem, and the resulting barrier terms are scaled by estimates of the optimal Lagrange multipliers. The condition number of the Hessian matrix of the resulting modified barrier function remains bounded as the solution to the constrained optimization problem is approached. Both of these techniques can be used in the context of a truncated-Newton method, and hence can be applied to large problems, as well as on parallel computers. In this paper, both techniques are applied to problems with bound constraints and we compare their practical behavior.

Neuroimmune Axes of the Blood–Brain Barriers and Blood–Brain Interfaces: Bases for Physiological Regulation, Disease States, and Pharmacological Interventions

PubMed Central

Erickson, Michelle A.

2018-01-01

Central nervous system (CNS) barriers predominantly mediate the immune-privileged status of the brain, and are also important regulators of neuroimmune communication. It is increasingly appreciated that communication between the brain and immune system contributes to physiologic processes, adaptive responses, and disease states. In this review, we discuss the highly specialized features of brain barriers that regulate neuroimmune communication in health and disease. In section I, we discuss the concept of immune privilege, provide working definitions of brain barriers, and outline the historical work that contributed to the understanding of CNS barrier functions. In section II, we discuss the unique anatomic, cellular, and molecular characteristics of the vascular blood–brain barrier (BBB), blood–cerebrospinal fluid barrier, and tanycytic barriers that confer their functions as neuroimmune interfaces. In section III, we consider BBB-mediated neuroimmune functions and interactions categorized as five neuroimmune axes: disruption, responses to immune stimuli, uptake and transport of immunoactive substances, immune cell trafficking, and secretions of immunoactive substances. In section IV, we discuss neuroimmune functions of CNS barriers in physiologic and disease states, as well as pharmacological interventions for CNS diseases. Throughout this review, we highlight many recent advances that have contributed to the modern understanding of CNS barriers and their interface functions. PMID:29496890

[Recent studies on corneal epithelial barrier function].

PubMed

Liu, F F; Li, W; Liu, Z G; Chen, W S

2016-08-01

Corneal epithelium, the outermost layer of eyeball, is the main route for foreign materials to enter the eye. Under physiological conditions, the corneal epithelial superficial cells form a functionally selective permeability barrier. Integral corneal epithelial barrier function not only ensures the enrolling of nutrients which is required for regular metabolism, but also prevents foreign bodies, or disease-causing microorganism invasion. Recently, a large number of clinical and experimental studies have shown that abnormal corneal epithelial barrier function is the pathological basis for many ocular diseases. In addition, some study found that corneal epithelial barrier constitutes a variety of proteins involved in cell proliferation, differentiation, apoptosis, and a series of physiological and pathological processes. This paper reviewed recent studies specifically on the corneal epithelial barrier, highlights of its structure, function and influence factors. (Chin J Ophthalmol, 2016, 52: 631-635).

Targeting Nuclear EGFR: Strategies for Improving Cetuximab Therapy in Lung Cancer

DTIC Science & Technology

2014-09-01

Triple - negative breast cancer Mol Cancer Ther. 2014 May;13(5):1356-68. PMID: 24634415, PMCID: PMC4013210 6. Brand, TM, Iida, M...Receptor Is a Functional Molecular Target in Triple - Negative Breast Cancer . Molecular cancer therapeutics (2014). 11 26. Iida, M., Brand, T.M...2014). Brand, T.M., et al. Nuclear epidermal growth factor receptor is a functional molecular target in triple - negative breast cancer .

Evaluation of dermal-epidermal skin equivalents ('composite-skin') of human keratinocytes in a collagen-glycosaminoglycan matrix(Integra artificial skin).

PubMed

Kremer, M; Lang, E; Berger, A C

2000-09-01

Integra artificial skin (Integra LifeSciences Corp., Plainsboro, NJ, USA) is a dermal template consisting of bovine collagen, chondroitin-6-sulphate and a silastic membrane manufactured as Integra. This product has gained widespread use in the clinical treatment of third degree burn wounds and full thickness skin defects of different aetiologies. The product was designed to significantly reduce the time needed to achieve final wound closure in the treatment of major burn wounds, to optimise the sparse autologous donor skin resources and to improve the durable mechanical quality of the skin substitute. The clinical procedure requires two stages. The first step creates a self neodermis, the second creates a self epidermis on the neodermis. However, it is desirable to cover major burn wounds early in a single step by a skin substitute consisting of a dermal equivalent seeded in vitro with autologous keratinocytes ('composite-skin') out of which a full thickness skin develops in vivo.The goal of this experimental study was to develop a method to integrate human keratinocytes in homogeneous distribution and depth into Integra Artificial Skin. The seeded cell-matrix composites were grafted onto athymic mice in order to evaluate their potential to reconstitute a human epidermis in vivo. We were able to demonstrate that the inoculated human keratinocytes reproducibly displayed a homogeneous pattern of distribution, adherence, proliferation and confluence. The cell-matrix composites grafted in this model exhibited good wound adherence, complete healing, minor wound contraction and had the potential to reconstitute an elastic, functional and durable human skin. Histologically we were able to show that the inoculated human keratinocytes in vivo colonised the matrix in a histomorphologically characteristic epidermal pattern (keratomorula, keratinocyte bubbling) and developed a persisting, stratified, keratinising epidermis which immunohistologically proved to be of human origin. These experimental results demonstrate the establishment of an effective cell cultivation process which may be suitable for scale-up production of the epidermal component as large-scale composite-skin grafts. When seeded into Integratrade mark and grafted onto the nude mouse a replacement skin with normal functioning dermal-epidermal components was developed. These results encourage the design of a clinical trial to assess the function of this composite graft in man.

Functional conservation of Gsdma cluster genes specifically duplicated in the mouse genome.

PubMed

Tanaka, Shigekazu; Mizushina, Youichi; Kato, Yoriko; Tamura, Masaru; Shiroishi, Toshihiko

2013-10-03

Mouse Gasdermin A3 (Gsdma3) is the causative gene for dominant skin mutations exhibiting alopecia. Mouse has two other Gsdma3-related genes, Gsdma and Gsdma2, whereas human and rat have only one related gene. To date, no skin mutation has been reported for human GSDMA and rat Gsdma as well as mouse Gsdma and Gsdma2. Therefore, it is possible that only Gsdma3 has gain-of-function type mutations to cause dominant skin phenotype. To elucidate functional divergence among the Gsdma-related genes in mice, and to infer the function of the human and rat orthologs, we examined in vivo function of mouse Gsdma by generating Gsdma knockout mice and transgenic mice that overexpress wild-type Gsdma or Gsdma harboring a point mutation (Alanine339Threonine). The Gsdma knockout mice shows no visible phenotype, indicating that Gsdma is not essential for differentiation of epidermal cells and maintenance of the hair cycle, and that Gsdma is expressed specifically both in the inner root sheath of hair follicles and in suprabasal cell layers, whereas Gsdma3 is expressed only in suprabasal layers. By contrast, both types of the transgenic mice exhibited epidermal hyperplasia resembling the Gsdma3 mutations, although the phenotype depended on the genetic background. These results indicate that the mouse Gsdma and Gsdma3 genes share common function to regulate epithelial maintenance and/or homeostasis, and suggest that the function of human GSDMA and rat Gsdma, which are orthologs of mouse Gsdma, is conserved as well.

Studies of the structure-activity relationships of peptides and proteins involved in growth and development based on their three-dimensional structures.

PubMed

Nagata, Koji

2010-01-01

Peptides and proteins with similar amino acid sequences can have different biological functions. Knowledge of their three-dimensional molecular structures is critically important in identifying their functional determinants. In this review, I describe the results of our and other groups' structure-based functional characterization of insect insulin-like peptides, a crustacean hyperglycemic hormone-family peptide, a mammalian epidermal growth factor-family protein, and an intracellular signaling domain that recognizes proline-rich sequence.

Key Role of CRF in the Skin Stress Response System

PubMed Central

Zmijewski, Michal A.; Zbytek, Blazej; Tobin, Desmond J.; Theoharides, Theoharis C.; Rivier, Jean

2013-01-01

The discovery of corticotropin-releasing factor (CRF) or CRH defining the upper regulatory arm of the hypothalamic-pituitary-adrenal (HPA) axis, along with the identification of the corresponding receptors (CRFRs 1 and 2), represents a milestone in our understanding of central mechanisms regulating body and local homeostasis. We focused on the CRF-led signaling systems in the skin and offer a model for regulation of peripheral homeostasis based on the interaction of CRF and the structurally related urocortins with corresponding receptors and the resulting direct or indirect phenotypic effects that include regulation of epidermal barrier function, skin immune, pigmentary, adnexal, and dermal functions necessary to maintain local and systemic homeostasis. The regulatory modes of action include the classical CRF-led cutaneous equivalent of the central HPA axis, the expression and function of CRF and related peptides, and the stimulation of pro-opiomelanocortin peptides or cytokines. The key regulatory role is assigned to the CRFR-1α receptor, with other isoforms having modulatory effects. CRF can be released from sensory nerves and immune cells in response to emotional and environmental stressors. The expression sequence of peptides includes urocortin/CRF→pro-opiomelanocortin→ACTH, MSH, and β-endorphin. Expression of these peptides and of CRFR-1α is environmentally regulated, and their dysfunction can lead to skin and systemic diseases. Environmentally stressed skin can activate both the central and local HPA axis through either sensory nerves or humoral factors to turn on homeostatic responses counteracting cutaneous and systemic environmental damage. CRF and CRFR-1 may constitute novel targets through the use of specific agonists or antagonists, especially for therapy of skin diseases that worsen with stress, such as atopic dermatitis and psoriasis. PMID:23939821