Tape-stripped Samples Research Articles

The effect of degeneration of elastic fibres on loss of elasticity and wrinkle formation.

Skin elasticity, which is vital for a youthful appearance, depends on the elastic fibres in the dermis. However, these fibres deteriorate with ageing, resulting in wrinkles and sagging. Changes that occur in the elastic fibres in living human skin and the relationship between elastic fibres and the state of the skin surface remain unclear. Therefore, it is necessary to verify the relationship between elastic fibres and skin elasticity. In this study, we investigated the association of the elastic fibre structure with skin elasticity and stratum corneum protein content in living human skin. Thirty-five female volunteers aged 25-66 years were included in this study. Elastic fibres were observed using a multiphoton scanning laser biomicroscope. Skin elasticity was measured using a Cutometer, and stratum corneum proteins (Heat-shock protein 27 [HSP27] and galectin-7 [Gal-7]) in tape-stripped samples were analysed using an enzyme-linked immunosorbent assay. Elastic fibres exhibited increased curvature and thickness with increased age, with fragmentation observed in women aged >60 years. Elastin scores, which reflect thinness and curvature, were negatively correlated with age, whereas they were positively correlated with R7 elasticity (recovery ability). In individuals aged 20-30 years, higher levels of inflammatory markers (HSP27 and Gal-7) correlated with lower elastin scores; however, this trend was not observed in older participants. Elastic fibre deterioration worsened after 40 years of age, and this effect correlated with reduced skin recovery and increased wrinkles. In younger individuals, inflammatory markers affected elastic fibres. These findings can guide anti-ageing strategies that focus on elastic fibre preservation and inflammation control.

Non-invasive diagnosis of early cutaneous squamous cell carcinoma.

Early cutaneous squamous cell carcinoma (cSCC) can be challenging to diagnose using clinical criteria as it could present similar to actinic keratosis (AK) or Bowen's disease (BD), precursors of cSCC. Currently, histopathological assessment of an invasive biopsy is the gold standard for diagnosis. A non-invasive diagnostic approach would reduce patient and health system burden. Therefore, this study used non-invasive sampling by tape-stripping coupled with data-independent acquisition mass spectrometry (DIA-MS) proteomics to profile the proteome of histopathologically diagnosed AK, BD and cSCC, as well as matched normal samples. Proteomic data were analysed to identify proteins and biological functions that are significantly different between lesions. Additionally, a support vector machine (SVM) machine learning algorithm was used to assess the usefulness of proteomic data for the early diagnosis of cSCC. A total of 696 proteins were identified across the samples studied. A machine learning model constructed using the proteomic data classified premalignant (AK + BD) and malignant (cSCC) lesions at 77.5% accuracy. Differential abundance analysis identified 144 and 21 protein groups that were significantly changed in the cSCC, and BD samples compared to the normal skin, respectively (adj. p < 0.05). Changes in pivotal carcinogenic pathways such as LXR/RXR activation, production of reactive oxygen species, and Hippo signalling were observed that may explain the progression of cSCC from premalignant lesions. In summary, this study demonstrates that DIA-MS analysis of tape-stripped samples can identify non-invasive protein biomarkers with the potential to be developed into a complementary diagnostic tool for early cSCC.

A noninvasive method for whole-genome skin methylome profiling.

Ageing, disease and malignant transformation of the skin are associated with changes in DNA methylation. So far, mostly invasive methodologies such as biopsies have been applied in collecting DNA methylation signatures. Tape stripping offers a noninvasive option for skin diagnostics. It enables the easy but robust capture of biologic material in large numbers of participants without the need for specialized medical personnel. To design and validate a methodology for noninvasive skin sample collection using tape stripping for subsequent DNA -methylation analysis. A total of 175 participants were recruited and provided tape-stripping samples from a sun-exposed area; 92 provided matched tape-stripping samples from a sun-protected area, and an additional 5 provided matched skin-shave biopsies from the same area. Using -enzymatic conversion and whole-genome Illumina sequencing, we generated genome-wide DNA methylation profiles that were used to evaluate the feasibility of noninvasive data acquisition, to compare with established sampling approaches and to investigate biomarker identification for age and ultraviolet (UV) exposure. We found that tape-stripping samples showed strong concordance in their global DNA methylation landscapes to those of conventional invasive biopsies. Moreover, we showed sample reproducibility and consistent global methylation profiles in skin tape-stripping samples collected from different areas of the body. Using matched samples from sun-protected and sun-exposed areas of the body we were able to validate the capacity of our method to capture the effects of environmental changes and ageing in a cohort covering various ages, ethnicities and skin types. We found DNA methylation changes on the skin resulting from UV exposure and identified significant age-related hypermethylation of CpG islands, with a pronounced peak effect at 50-55 years of age, including methylation changes in well-described markers of ageing. These data demonstrate the feasibility of using tape stripping combined with whole-genome sequencing as a noninvasive approach to measuring DNA methylation changes in the skin. In addition, they outline a viable experimental framework for the use of skin tape stripping, particularly when it is performed in large cohorts of patients to identify biomarkers of skin ageing, UV damage and, possibly, to track treatment response to therapeutic interventions.

P40 Dupilumab treatment restores skin barrier function in lesional and nonlesional skin of patients with atopic dermatitis and improves patient-reported outcomes

Abstract The objective of this analysis is to report the effect of dupilumab treatment on skin barrier function and patient-reported outcomes (PROs) in adults and adolescents with moderate-to-severe atopic dermatitis (AD). BALISTAD (NCT04447417) was an open-label trial in which transepidermal water loss (TEWL) was assessed repeatedly before and after skin tape stripping (STS) samples were taken from lesional and nonlesional skin of 26 patients with AD treated with dupilumab, and from normal skin of 26 matched healthy volunteers aged 12–65 years over a period of 16 weeks. PROs assessed included Patient-Oriented Eczema Measure (POEM), Peak Pruritus Numerical Rating Scale (PP-NRS) and Dermatological Life Quality Index [DLQI; for patients &amp;gt; 17 years old; Children’s DLQI (CDLQI) for patients aged &amp;gt; 12 to &amp;lt; 17 years]. At baseline, the median TEWL after five STS was statistically significantly higher in the lesional and nonlesional skin of patients with AD compared with healthy skin (P &amp;lt; 0.001 and P &amp;lt; 0.01, respectively) and statistically significantly decreased following dupilumab initiation as early as week 2 (P &amp;lt; 0.001 and P &amp;lt; 0.05, respectively). After 16 weeks of dupilumab treatment, there was no statistically significant difference in adjusted mean TEWL in AD lesional and nonlesional skin compared with matched healthy skin (P = 0.225 and P = 0.163, respectively). Significant improvement from baseline [mean (SD) change from baseline] was seen as early as week 2 in mean POEM [−8.4 (5.1)], DLQI [−5.3 (4.7)], CDLQI [−6.2 (4.7)] and PP-NRS [−2.2 (1.8); P &amp;lt; 0.001 and P &amp;lt; 0.05)] for CDLQI. Improvement was sustained through to week 16 [mean (SD) change from baseline; P &amp;lt; 0.001] for POEM [−13.6 (8.5)], DLQI [−8.6 (7.4)] and PP-NRS [−4.2 (2.6)] and with a P-value of &amp;lt; 0.01 for CDLQI [−9.2 (5.0)]. Dupilumab treatment normalizes epidermal barrier function in lesional and nonlesional skin in patients with moderate-to-severe AD, as measured with TEWL, and improves PROs. Funding sources: research sponsored by Sanofi and Regeneron Pharmaceuticals Inc.

Oral vitamin D modulates the epidermal expression of the vitamin D receptor and cathelicidin in children with atopic dermatitis.

Although vitamin D (VD) is known to have multiple effects on the skin and immunity, its effects on atopic dermatitis (AD) severity remain unclear. We investigated whether oral cholecalciferol (VD3) supplementation changes stratum corneum expression of the vitamin D receptor (vdr), and the epidermal alarmins Cathelicidin Antimicrobial Peptide (camp/LL-37) and Thymic Stromal Lymphopoietin (tslp) in children with AD. We conducted an open-label supplementation study with weekly oral VD3 for six weeks in children with AD. Serum 25-hydroxyvitamin D (25OHD), lesional Staphylococcus aureus colonization, and AD severity evaluated by SCORAD index were evaluated before and after supplementation. Tape stripping (TS) was performed on non-lesional and lesional skin to measure mRNA expression of vdr, camp, and tslp through RT-qPCR and LL-37 peptide by ELISA. Twenty-two children with moderate-severe AD received weekly oral VD3 for six weeks. Total serum 25OHD increased from 45.1 ± 23 to 93.5 ± 24.3 nmoL/L (p < 0.0001), while SCORAD decreased from 41.4 ± 13.5 to 31.5 ± 15.8 (p < 0.0001). After treatment, epidermal gene expression of camp increased significantly in non-lesional (p = 0.014) and lesional (p = 0.0007) tape stripping samples, while vdr only increased in lesional skin samples (p < 0.0001). LL-37 peptide increased significantly only in lesional skin samples (p = 0.008). Gene expression of tslp did not change after oral VD3 treatment. In children with AD, oral VD3 supplementation was associated with improved VD status and AD severity, as well as increased VDR and Cathelicidin expression in lesional skin, which provide mechanistic clues on its effects.

Skin Microbiota Profiles from Tape Stripping and Skin Biopsy Samples of Patients with Psoriasis Treated with Narrowband Ultraviolet B.

PurposeAlthough the pathogenesis of psoriasis involves the dermis, most previous studies collected samples using the swab technique. A recent study examining the microbiomes obtained via both skin biopsies and swabs revealed a significant difference in normal skin. We hypothesized that the microbiome profile of patients with psoriasis from tape stripping and skin biopsy might be different. This study sought to contribute to microbiome research on psoriasis by investigating the changes in the microbiome during narrowband ultraviolet B (NBUVB) therapy by comparing the results from the different sampling techniques of tape stripping and skin biopsy.Patients and MethodsTwenty-three participants, including 14 patients with chronic plaque psoriasis and nine healthy controls, were recruited, and nine patients with psoriasis completed 20-sessions of NBUVB treatment. Skin microbiota from both techniques was analyzed using the 16S rRNA gene at baseline and after treatment.ResultsA clear difference was observed between the results from the two sampling techniques. Alpha diversity of the microbiota obtained from tape stripping was higher than that of the microbiota from skin biopsy, whereas beta diversity was clustered into two groups by sampling technique. The microbiome was altered during NBUVB treatment using both sampling techniques.ConclusionDifferent sampling techniques resulted in different microbiome profiles in patients with psoriasis. Tape stripping and swabs are feasible procedures and are mostly used in psoriasis and other skin microbiome studies; however, skin biopsy may also expand our understanding of psoriasis and other skin diseases that pathophysiology involves deeper to the dermis or subcutaneous tissue.

The human vermilion surface contains a rich amount of cholesterol sulfate than the skin

BackgroundThe vermilion of the human lip presents characteristic features and undergoes aging faster than the skin. Therefore, knowledge of the vermilion surface-specific functional molecules is important to understand lip aging and formulate lip care products. Previously, we analyzed the free fatty acids distributions and showed that docosahexaenoic acid highly accumulated in the vermilion's epithelium than in the skin. ObjectiveWe aimed to explore the functional molecules other than the free fatty acids on the vermilion's surface. MethodsHuman lip tissues from children and tape-stripped samples from smooth and rough lips of adults were measured by desorption electrospray ionization-mass spectrometry imaging (DESI-MSI). ResultsDESI-MSI of children's lip sections revealed a major distribution of five phospholipid species in the viable layer, but not in the superficial area, of both the vermilion and the skin than that in the underlying tissue. Interestingly, a remarkably higher distribution of cholesterol sulfate was observed in the vermilion's superficial area compared to that in the skin in all subjects under this study. Furthermore, DESI-MSI of tape-stripped lip samples showed an overall higher accumulation of cholesterol sulfate in the stratum corneum of the rough lips than that in the smooth lips. ConclusionOur study concluded that cholesterol sulfate has a characteristic distribution to the vermilion's surface and showed an association with the roughness of the lip.

Particulate matter causes skin barrier dysfunction.

The molecular mechanisms that underlie the detrimental effects of particulate matter (PM) on skin barrier function are poorly understood. In this study, the effects of PM2.5 on filaggrin (FLG) and skin barrier function were investigated in vitro and in vivo. The levels of FLG degradation products, including pyrrolidone carboxylic acid, urocanic acid (UCA), and cis/trans-UCA, were significantly decreased in skin tape stripping samples of study subjects when they moved from Denver, an area with low PM2.5, to Seoul, an area with high PM2.5 count. Experimentally, PM2.5 collected in Seoul inhibited FLG, loricrin, keratin-1, desmocollin-1, and corneodesmosin but did not modulate involucrin or claudin-1 in keratinocyte cultures. Moreover, FLG protein expression was inhibited in human skin equivalents and murine skin treated with PM2.5. We demonstrate that this process was mediated by PM2.5-induced TNF-α and was aryl hydrocarbon receptor dependent. PM2.5 exposure compromised skin barrier function, resulting in increased transepidermal water loss, and enhanced the penetration of FITC-dextran in organotypic and mouse skin. PM2.5-induced TNF-α caused FLG deficiency in the skin and subsequently induced skin barrier dysfunction. Compromised skin barrier due to PM2.5 exposure may contribute to the development and the exacerbation of allergic diseases such as atopic dermatitis.

Skin tape stripping identifies gene transcript signature associated with allergic contact dermatitis.

Allergic contact dermatitis (ACD) and irritant contact dermatitis (ICD) are common skin conditions with an overlapping clinical and histological appearance, but distinct underlying mechanisms. Patch testing is the gold standard for ACD diagnosis, yet the interpretation of its results may be confounded by weak and varying macroscopic reactions. To examine whether gene transcript profiling of RNA sampled from patch tested patient skin by tape stripping (TS) could differentiate ACD from ICD and the baseline skin state (control) METHODS: Nine patients (seven females, two males; mean age 38.6 years, range 24-72 years) with confirmed ACD through patch testing were recruited. Total RNA was isolated from TS samples and relative transcript abundance was determined by quantitative real-time polymeraise chain reaction using 39 gene-specific primers. TS captured gene transcripts derived from diverse skin cell types, including not only keratinocytes, but also epidermal and dermal antigen-presenting cells. Among the genes analysed in transcript profiling, genes encoding epidermal barrier components and inflammatory mediators exhibited changes in transcript abundance in ACD skin compared to ICD or control skin. Our findings reveal the potential of skin TS for non-invasive biopsy during patch testing and molecular marker-based ACD diagnosis.

Tape-Stripping Electrochemical Detection of Melanoma

A noninvasive electrochemical melanoma detection approach based on using adhesive tapes for collecting and fixing cells from a suspicious skin area and transferring the cells into a scanning electrochemical microscope (SECM) is presented. The adhesive layer collects the cells reproducibly and keeps them well adhered on the tape during experiments in an electrolyte solution. A melanoma biomarker, here the intracellular enzyme tyrosinase (TYR), was imaged on the tape-collected cells without further cell lysing using antibodies that were labeled with horseradish peroxidase (HRP). The HRP labels catalyzed the oxidation of a dissolved redox-active species, which was detected at a soft microelectrode, gently brushed in contact mode over the tape. The melanoma biomarker was first detected on tape-stripped samples with murine melanoma cells of different concentrations. Thereafter, increasing levels of TYR were recorded in cells that were collected from the skin of melanoma mouse models representing three different stages of tumor growth. Additionally, SECM results of tape-stripped different human melanoma cell lines were confirmed by previous studies based on traditionally fixed and permeabilized cells.

311 Niacinamide reduces in vivo inflammatory response due to skin barrier disruption

Introduction: Impaired skin barrier function has been suggested to underlie sensitive skin. Sensitive skin triggers such as surfactant irritation or mechanical abrasion result in barrier damage and skin inflammation. In subjects with darker skin types, inflammation will also often result in the formation of post-inflammatory hyperpigmentation (PIH). In-vivo efficacy of niacinamide against inflammation caused by barrier damage has not yet been demonstrated. Objective: The goal of the clinical study and ex vivo studies was to understand the role of niacinamide in reducing inflammation and skin tone changes induced by barrier disruption. Materials and Methods: In this single center, randomized, single blinded study a provocation method was executed to mimic sensitive skin response to washing. In this 8-week study, 20 Chinese females were asked to perform the provocation method with or without niacinamide product. Skin chromophores and structure were assessed using CM2600D and the reflectance confocal microscopy (RCM), respectively. Tape stripping samples were obtained for lipidomic analysis. Results: It was found that the barrier disruption followed by washing with a cleansing bar leads to structural skin changes and impacts various skin chromophores. Niacinamide significantly protected skin chromophore changes at multiple timepoints and maintained normal epidermal thickness. Lipidomics analysis confirmed increased expression of various inflammatory lipids which were significantly reduced by niacinamide. Conclusions: Barrier disruption leads to dynamic changes on phenotypical and biological endpoints. Niacinamide showed significant protective effects for various inflammatory end points as well as PIH development and recovery.

Galectin-7 in the stratum corneum: a biomarker of the skin barrier function.

Skin barrier disruption often occurs in diseased and damaged skin conditions such as atopic dermatitis (AD). We focused the galectin-7 protein (Gal-7) as a biomarker of skin condition and assessed whether the content of Gal-7 in stratum corneum (scGal-7) could be used as an indicator of skin barrier disruption and as an index of local skin symptoms in AD patients. Alteration of Gal-7 expression levels in keratinocyte and scGal-7 contents after barrier disruption by sodium dodecyl sulphate were evaluated in vitro and in vivo, respectively. Correlation between scGal-7 content and transepidermal water loss (TEWL) was examined in 126 healthy subjects. We performed single measurements of scGal-7 contents in 34 AD patients and serial measurements of 15 inpatients among them. SC samples were collected by the tape-stripping method, and scGal-7 content was determined using enzyme-linked immunosorbent assay. Gal-7 expression in keratinocytes increased after barrier disruption. The scGal-7 content reflected the disruption of the skin barrier. The scGal-7 contents and TEWL values correlated in healthy subjects. The scGal-7 level was higher in AD patients than in healthy subjects. The scGal-7 contents in the cheek and neck of AD patients significantly correlated with the total and local skin lesion severity scores. Serial measurements in the inpatients showed that the scGal-7 contents in the cheek and neck decreased in tandem with local severity scores in response to treatment. Measurement of scGal-7 content in tape-stripped samples was useful for the evaluation of the skin barrier function in dry skin conditions such as AD.

Evaluation of Gene Expression Using a Skin Tape Stripping Method

E S D A Y 848 Evaluation of Gene Expression Using a Skin Tape Stripping Method Byung Eui Kim, MD, PhD, Un Ha Lee, Peter Sang Kim, Donald Y. M. Leung, MD, PhD, FAAAAI; National Jewish Health, Denver, CO, Inje University, Paik Hospital, National Jewish Health. RATIONALE: Skin tape stripping is a non-invasive method used to evaluate epidermal protein expression. However, this technique has not been verified whether this skill is reliable to evaluate gene expression. METHODS: Skin tape stripping samples and skin punch biopsies were collected from 10 normal subjects and 10 patients with atopic dermatitis (AD). Total RNAwas isolated from the same donors for skin tape stripping samples and skin biopsies, and then real time RT-PCR was performed for filaggrin (FLG), thymic stromal lymphopoietin (TSLP) and loricrin (LOR). RESULTS: FLG gene expression was significantly decreased in lesional AD skin compared with skin from normal subjects in both tape stripping samples (P<0.05) and skin biopsies (P<0.05). LOR gene expression was also significantly decreased in lesional AD skin compared with skin from normal subjects in skin tape stripping samples (P<0.01) and skin biopsies (P<0.05). Additionally, LOR gene expression was significantly decreased (P<0.05) in nonlesional AD skin compared with normal subjects in tape stripping samples. TSLP gene expression from tape stripped samples was significantly increased in lesional AD skin compared with skin from normal subjects (P<0.05) and nonlesional AD (P<0.05). CONCLUSIONS: Using PCR data from both tape stripping samples and skin biopsies, we have found reduced filaggrin and loricrin, but increased TSLP, gene expression in AD. Skin tape stripping method may be used to examine gene expression in the skin since it is a non-invasive, and can be used for serial evaluation of the skin and protein expression. However, further study is required to validate this method.

Dominant Proportion of Staphylcoccus Aureus in the Skin of Atopic Dermatitis Patients through Metagenomic Analysis

E S D A Y 848 Evaluation of Gene Expression Using a Skin Tape Stripping Method Byung Eui Kim, MD, PhD, Un Ha Lee, Peter Sang Kim, Donald Y. M. Leung, MD, PhD, FAAAAI; National Jewish Health, Denver, CO, Inje University, Paik Hospital, National Jewish Health. RATIONALE: Skin tape stripping is a non-invasive method used to evaluate epidermal protein expression. However, this technique has not been verified whether this skill is reliable to evaluate gene expression. METHODS: Skin tape stripping samples and skin punch biopsies were collected from 10 normal subjects and 10 patients with atopic dermatitis (AD). Total RNAwas isolated from the same donors for skin tape stripping samples and skin biopsies, and then real time RT-PCR was performed for filaggrin (FLG), thymic stromal lymphopoietin (TSLP) and loricrin (LOR). RESULTS: FLG gene expression was significantly decreased in lesional AD skin compared with skin from normal subjects in both tape stripping samples (P<0.05) and skin biopsies (P<0.05). LOR gene expression was also significantly decreased in lesional AD skin compared with skin from normal subjects in skin tape stripping samples (P<0.01) and skin biopsies (P<0.05). Additionally, LOR gene expression was significantly decreased (P<0.05) in nonlesional AD skin compared with normal subjects in tape stripping samples. TSLP gene expression from tape stripped samples was significantly increased in lesional AD skin compared with skin from normal subjects (P<0.05) and nonlesional AD (P<0.05). CONCLUSIONS: Using PCR data from both tape stripping samples and skin biopsies, we have found reduced filaggrin and loricrin, but increased TSLP, gene expression in AD. Skin tape stripping method may be used to examine gene expression in the skin since it is a non-invasive, and can be used for serial evaluation of the skin and protein expression. However, further study is required to validate this method.

Short-Term Effect of Airborne Formaldehyde on Skin Barrier Function in Atopic Dermatitis

E S D A Y 848 Evaluation of Gene Expression Using a Skin Tape Stripping Method Byung Eui Kim, MD, PhD, Un Ha Lee, Peter Sang Kim, Donald Y. M. Leung, MD, PhD, FAAAAI; National Jewish Health, Denver, CO, Inje University, Paik Hospital, National Jewish Health. RATIONALE: Skin tape stripping is a non-invasive method used to evaluate epidermal protein expression. However, this technique has not been verified whether this skill is reliable to evaluate gene expression. METHODS: Skin tape stripping samples and skin punch biopsies were collected from 10 normal subjects and 10 patients with atopic dermatitis (AD). Total RNAwas isolated from the same donors for skin tape stripping samples and skin biopsies, and then real time RT-PCR was performed for filaggrin (FLG), thymic stromal lymphopoietin (TSLP) and loricrin (LOR). RESULTS: FLG gene expression was significantly decreased in lesional AD skin compared with skin from normal subjects in both tape stripping samples (P<0.05) and skin biopsies (P<0.05). LOR gene expression was also significantly decreased in lesional AD skin compared with skin from normal subjects in skin tape stripping samples (P<0.01) and skin biopsies (P<0.05). Additionally, LOR gene expression was significantly decreased (P<0.05) in nonlesional AD skin compared with normal subjects in tape stripping samples. TSLP gene expression from tape stripped samples was significantly increased in lesional AD skin compared with skin from normal subjects (P<0.05) and nonlesional AD (P<0.05). CONCLUSIONS: Using PCR data from both tape stripping samples and skin biopsies, we have found reduced filaggrin and loricrin, but increased TSLP, gene expression in AD. Skin tape stripping method may be used to examine gene expression in the skin since it is a non-invasive, and can be used for serial evaluation of the skin and protein expression. However, further study is required to validate this method.

Gene expression profiling in pachyonychia congenita skin

BackgroundPachyonychia congenita (PC) is a skin disorder resulting from mutations in keratin (K) proteins including K6a, K6b, K16, and K17. One of the major symptoms is painful plantar keratoderma. The pathogenic sequelae resulting from the keratin mutations remain unclear. ObjectiveTo better understand PC pathogenesis. MethodsRNA profiling was performed on biopsies taken from PC-involved and uninvolved plantar skin of seven genotyped PC patients (two K6a, one K6b, three K16, and one K17) as well as from control volunteers. Protein profiling was generated from tape-stripping samples. ResultsA comparison of PC-involved skin biopsies to adjacent uninvolved plantar skin identified 112 differentially-expressed mRNAs common to patient groups harboring K6 (i.e., both K6a and K6b) and K16 mutations. Among these mRNAs, 25 encode structural proteins including keratins, small proline-rich and late cornified envelope proteins, 20 are related to metabolism and 16 encode proteases, peptidases, and their inhibitors including kallikrein-related peptidases (KLKs), and serine protease inhibitors (SERPINs). mRNAs were also identified to be differentially expressed only in K6 (81) or K16 (141) patient samples. Furthermore, 13 mRNAs were identified that may be involved in pain including nociception and neuropathy. Protein profiling, comparing three K6a plantar tape-stripping samples to non-PC controls, showed changes in the PC corneocytes similar, but not identical, to the mRNA analysis. ConclusionMany differentially-expressed genes identified in PC-involved skin encode components critical for skin barrier homeostasis including keratinocyte proliferation, differentiation, cornification, and desquamation. The profiling data provide a foundation for unraveling the pathogenesis of PC and identifying targets for developing effective PC therapeutics.

Characterisation of skin barrier function using bioengineering and biophysical techniques.

To characterise skin barrier function in vivo at two distinct anatomic sites using minimally invasive bioengineering and biophysical tools. In healthy human volunteers, the quantities of stratum corneum (SC) per unit area of skin on the forearm and forehead were quantified by gravimetric and imaging techniques. Organisation of the SC intercellular lipids was evaluated as a function of position using attenuated total reflectance infrared spectroscopy (ATR-IR). The constituents of natural moisturising factor (NMF) were extracted from tape-stripped samples of the SC and by reverse iontophoresis; 21 components were identified and quantified by liquid chromatography with mass spectrometric detection. SC was quantified more accurately by imaging and was significantly thinner on the forehead than on the forearm. Intercellular lipids were more disordered near the skin surface at both sites; however, throughout forearm SC, the lipids were substantially better organised than those in the forehead. Compositionally, the NMF from forearm and forehead SC was similar, but the total amount extractable from the forehead was smaller. Taken together, the bioengineering and biophysical techniques employed demonstrate, in a complementary, objective and quantitative fashion, that SC barrier function on the forehead is less competent than that on the forearm.

A convenient and highly sensitive method for quantification of ceramide in tape-stripping samples by dot-blot analysis as a skin barrier assessment technique in murine macerated skin

A convenient and highly sensitive method for quantification of ceramide in tape-stripping samples by dot-blot analysis as a skin barrier assessment technique in murine macerated skin

New non‐invasive method for evaluation of the stratum corneum structure in diseases with abnormal keratinization by immunofluorescence microscopy of desmoglein 1 distribution in tape‐stripped samples

The corneodesmosomes in the stratum corneum are critical for the maintenance of stratum corneum integrity. To evaluate the normal and diseased keratinization states in the epidermis, we studied the distribution of desmoglein 1 (DSG1), a major component of corneodesmosomes, in samples of the stratum corneum obtained by tape stripping, a non-invasive method. Samples were collected from lesional skin of four patients with psoriasis and three with lichen planus, and from non-lesional skin of three volunteers. Upper stratum corneum cells were obtained by tape stripping and skin biopsies were obtained from adjacent sites. Tape-stripped samples were examined by immunofluorescence microscopy using anti-DSG1 monoclonal antibody, in combination with histopathology of skin biopsies. In normal human stratum corneum, which shows basket-woven orthokeratosis, DSG1-containing fluorescent dots were distributed on the lateral cell-cell contact areas of plasma membrane, but not on the dorsal/ventral plasma membrane, and formed a well-ordered hexagonal network structure. In psoriatic stratum corneum, fluorescent dots were distributed throughout the cell membrane at ventral aspects of corneocytes as well as at the lateral cell-cell contacts. In lichen planus, fluorescent dots were distributed homogeneously and/or heterogeneously on the ventral surface in some cells. Adjacent cells lacked DSG1 at the lateral cell-cell contacts, but were instead separated by distinctive black-gap lines. These results suggest that the intercellular adhesion by DSG1 may depend on the lateral plasma membrane in normal human stratum corneum, on the dorsal/ventral plasma membrane in lichen planus, and on both lateral and dorsal/ventral plasma membranes in psoriatic stratum corneum. Tape stripping and DSG1 immunofluorescence visualizes adhesion features of corneocytes and has considerable potential for evaluation of abnormal keratinization and the process of healing in response to treatment.

Laboratory Simulation Study on Quantifying Tape-Stripping Samples of Multifunctional Acrylates with Fourier Transform Infrared Spectroscopy

Laboratory Simulation Study on Quantifying Tape-Stripping Samples of Multifunctional Acrylates with Fourier Transform Infrared Spectroscopy