An increased ratio of interleukin-1 receptor antagonist to interleukin-1alpha in inflammatory skin diseases

Natural moisturising factor constituents in South African nursing students

BACKGROUND

The majority of South African healthcare workers are Black Africans with dark-pigmented skin. Studies on how the markers of skin barrier function and natural moisturising factor (NMF) compare between dark and light-pigmented skin are limited. Quantifying NMF in a nursing student population during their practical training at university may provide valuable insight into their potential susceptibility to skin conditions associated with low NMF.

OBJECTIVES

The objectives of this study were to quantify and compare NMF content of Black African, Mixed Race and White nursing students from their dominant dorsal hand.

METHODS

Forty-nine White, 32 Black African and 5 Mixed Race nursing students participated in this study. Tape strip samples were collected from the participants' dominant dorsal hand and NMF content was measured, including histidine (HIS), pyrrolidone carboxylic acid (PCA), trans-urocanic acid (t-UCA) and cis-urocanic acid (c-UCA), as well as cytokines interleukin-1 alpha (IL-1α) and interleukin-1 receptor antagonist (IL-1RA).

RESULTS

No statistically significant differences in PCA, t-UCA, c-UCA, IL-1α or IL-1RA were found between Black African and White nursing students. HIS was significantly (p = 0.001) higher in White nursing students when compared to Black African students. The ratio of tot-UCA/HIS was significantly higher in Black Africans (p = 0.0002) when compared to White nursing students.

CONCLUSION

No significant differences were established in NMF content between White and Black African nursing students, other than HIS which was significantly higher in White students than in Black African students. Different HIS levels between the racial groups suggest variation in histidase activity which may be related to skin pH and pigmentation. This finding may suggest that nursing students at the beginning of their careers may have similar susceptibility to skin diseases related to NMF.

Inflammatory biomarkers in sebum for identifying skin damage in patients with a Stage I pressure ulcer in the pelvic region: A single centre observational, longitudinal cohort study with elderly patients

Pressure Ulcers (PU) are a major burden for affected patients and healthcare providers. Current detection methods involve visual assessments of the skin by healthcare professionals. This has been shown to be subjective and unreliable, with challenges associated with identifying erythema in darker colour skin. Although there exists a number of promising non-invasive biophysical techniques such as ultrasound, capacitance measurements, and thermography, the present study focuses on directly measuring the changes in the inflammatory status of the skin and underlying tissues. Therefore, in this study, we aim to analyse inflammatory cytokines collected through non-invasive sampling techniques to detect early signs of skin damage. Thirty hospitalised patients presenting with Stage I PU were recruited to evaluate the inflammatory response of skin at the site of damage and an adjacent healthy control site. Sebutapes were collected over three sessions to investigate the temporal changes in the inflammatory response. The panel of cytokines investigated included high-abundance cytokines, namely, IL-1α and IL-1RA, and low abundance cytokines; IL-6, IL-8, TNF-α, INF-γ, IL-33, IL-1β and G-CSF. Spatial and temporal differences between sites were assessed and thresholds were used to determine the sensitivity and specificity of each biomarker. The results suggest significant (P < .05) spatial changes in the inflammatory response, with upregulation of IL-1α, IL-8, and G-CSF as well as down-regulation of IL-1RA over the Stage I PU compared with the adjacent control site. There were no significant temporal differences between the three sessions. Selected cytokines, namely, IL-1α, IL-1RA, IL-8, G-CSF, and the ratio IL-1α/IL-1RA offered clear delineation in the classification of healthy and Stage-I PU skin sites, with receiver operating characteristic curves demonstrating high sensitivity and specificity. There were limited influences of intrinsic and extrinsic factors on the biomarker response. Inflammatory markers provided a high level of discrimination between the sites presenting with Stage I PU and an adjacent healthy skin site, in a cohort of elderly inpatients. Indeed, the ratio of IL-1α to IL-1RA provided the highest sensitivity and specificity, indicative that inflammatory homeostasis is affected at the PU site. There was a marginal influence of intrinsic and extrinsic factors, demonstrating the localised effects of the inflammation. Further studies are required to investigate the potential of inflammatory cytokines incorporated within Point of Care technologies, to support routine clinical use.

Oleic acid-induced interleukin-36γ: A possible link between facial skin redness and sebum

BACKGROUND

Redness of the facial skin is an important cosmetic concern. Although qualitative and quantitative modifications of sebum on the skin surface are major pathogenic factors of chronic inflammatory skin conditions, the relationship between skin redness, sebum, and mild inflammation on the cheeks of healthy subjects remains elusive.

AIMS

We aimed to explore the correlation between cheek redness and sebum and inflammatory cytokines in the stratum corneum (SC) of healthy subjects. We also examined the effects of representative sebum lipids on the gene expression of inflammatory cytokines in cultured keratinocytes.

PATIENTS/METHODS

This study included 198 healthy participants. Skin sebum was analyzed using flow injection analysis, and skin redness was assessed using a spectrophotometer. Inflammatory cytokines in tape-stripped SC were measured using enzyme-linked immunosorbent assay.

RESULTS

Cheek redness parameters positively correlated with the amount of skin sebum and the proportion of monounsaturated free fatty acids (C16:1 and C18:1) in the sebum. They also positively correlated with the interleukin (IL)-36γ/IL-37 ratio in the SC. Among the representative sebum lipids examined, oleic acid (C18:1, cis-9) dose- and time-dependently regulated the mRNA expression of IL-36γ and IL-37 in cultured keratinocytes, and this effect was attenuated by the N-methyl-D-aspartate (NMDA)-type glutamate receptor antagonist, MK801.

CONCLUSIONS

Skin surface sebum may be related to cheek redness in healthy subjects, and oleic acid-induced IL-36γ through NMDA-type glutamate receptors may be a link between them. Our study provides a possible skincare strategy for mitigating unfavorable increase in skin redness by targeting the facial skin sebum, particularly oleic acid.

The Effects of Combined Exposure to Simulated Microgravity, Ionizing Radiation, and Cortisol on the In Vitro Wound Healing Process

Human spaceflight is associated with several health-related issues as a result of long-term exposure to microgravity, ionizing radiation, and higher levels of psychological stress. Frequent reported skin problems in space include rashes, itches, and a delayed wound healing. Access to space is restricted by financial and logistical issues; as a consequence, experimental sample sizes are often small, which limits the generalization of the results. Earth-based simulation models can be used to investigate cellular responses as a result of exposure to certain spaceflight stressors. Here, we describe the development of an in vitro model of the simulated spaceflight environment, which we used to investigate the combined effect of simulated microgravity using the random positioning machine (RPM), ionizing radiation, and stress hormones on the wound-healing capacity of human dermal fibroblasts. Fibroblasts were exposed to cortisol, after which they were irradiated with different radiation qualities (including X-rays, protons, carbon ions, and iron ions) followed by exposure to simulated microgravity using a random positioning machine (RPM). Data related to the inflammatory, proliferation, and remodeling phase of wound healing has been collected. Results show that spaceflight stressors can interfere with the wound healing process at any phase. Moreover, several interactions between the different spaceflight stressors were found. This highlights the complexity that needs to be taken into account when studying the effect of spaceflight stressors on certain biological processes and for the aim of countermeasures development.

Assessment of soluble skin surface protein levels for monitoring psoriasis vulgaris in adult psoriasis patients using non-invasive transdermal analysis patch: A pilot study

To improve the care of patients with chronic inflammatory skin conditions, such as psoriasis, there is a need for diagnostic methods that can facilitate personalized medicine. This exploratory pilot study aimed to determine whether non-invasive measurements of inflammation-related proteins from psoriatic skin can be sampled using the FibroTx Transdermal Analysis Patch (TAP) to assess disease severity and monitor pharmacodynamic changes. Ten healthy volunteers and 44 psoriasis vulgaris patients were enrolled in the exploratory pilot study. Skin surface protein measurements for healthy and lesional skin were performed using TAP. Patients' scores of psoriasis activity and severity (PASI) were documented, and differences in the thickness of skin layers were determined using sonography. The study assessed the skin surface protein levels of psoriasis patients undergoing whole-body treatment with narrow-band UVB to evaluate whether the levels of the skin surface proteins IL-1α, IL-1RA CXCL-1/2, and hBD-1 were associated with the disease activity and severity measurements. Using TAP technology, it was observed that there were clear differences in levels of IL-1α, IL-1RA, CXCL-1/2, and hBD-1 between psoriasis lesional and non-lesional skin. In addition, a positive correlation between CXCL-1/2 and desquamation, and between CXCL-1/2 and SLEB thickness was observed. During UVB treatment, the TAP measurements revealed a clear reduction of IL-1RA, CXCL 1/2, and hBD-1 on lesional skin. Further, skin surface measurements of IL-1RA and CXCL-1/2 displayed a different profile than those achieved by visual scoring of local inflammation, thus indicating that measuring the 'molecular root' of inflammation appears to have value as an objective, non-invasive biomarker measurement for scoring disease severity.

Bioactive substances in the stratum corneum of the epidermis found as indicators of skin damage due to sun exposure

Background/Purpose

Although an inflammatory response upon acute injury caused by ultraviolet radiation (UV) can be observed immediately, the influence of long‐term, repetitive low‐dose UV exposure on the skin cannot be precisely perceived, making early detection of chronic damage difficult. This study investigated bioactive substances in the stratum corneum as a potential early and sensitive indicator of the influence of sun exposure on the skin using receiver operating characteristic (ROC) analysis.

Methods

Receiver operating characteristic analysis was performed to assess the responsiveness of cytokines [interleukin (IL)‐1α, IL‐1 receptor antagonist (IL‐1ra), IL‐10, tumor necrosis factor (TNF)‐α], BCL2‐associated protein X (Bax), Toll‐like receptor (TLR)3, and TLR4 in the stratum corneum of healthy people exposed (dorsum of the hand) and unexposed (inner arm) to UV. Sunscreen was applied to patients with photodermatosis for 4 weeks to evaluate changes in IL‐1ra/IL‐1α, TNF‐α, Bax, and TLR3 levels after sunscreen application, as these molecules exhibited high responsiveness to sun exposure according to ROC analysis. In addition, IL‐1ra, IL‐1α, and IL‐10 levels were quantified by enzyme‐linked immunosorbent assay, and TNF‐α, Bax, TLR3, and TLR4 levels were semi‐quantitatively assessed by immunocytochemistry.

Results

Receiver operating characteristic analysis identified IL‐1ra/IL‐1α, TNF‐α, Bax, and TLR3 in the stratum corneum as highly responsive to sun exposure. Moreover, in participants, including patients with photodermatosis, IL‐1ra/IL‐1α, TNF‐α, and Bax levels decreased significantly after sunscreen application.

Conclusion

The results revealed that IL‐1ra/IL‐1α, TNF‐α, and Bax in the stratum corneum represent sensitive indicators of the influence of sun exposure on the skin.

Stratum corneum levels of calprotectin proteins S100A8/A9 correlate with disease activity in psoriasis patients

Psoriasis is an intractable inflammatory skin disorder characterized by scaly erythema and plaques. The Psoriasis Area and Severity Index (PASI) is widely used to score disease severity, but evaluation is subjective, and an objective biomarker would be useful. The stratum corneum (SC), which can be non-invasively harvested, may reflect psoriasis-associated changes in epidermal keratinocytes, such as the upregulation of the calprotectin proteins S100A8 and S100A9. The aim of this study was to examine the availability of S100A8/A9 protein levels in SC as a biomarker of psoriasis disease activity. Fifty-three patients with psoriasis, 30 with psoriasis vulgaris (PsV), and 23 with psoriatic arthritis (PsA) participated. SC cells from lesional and non-lesional skin were collected by tape-stripping. S100A8/A9 levels in serum and in SC were quantified by enzyme-linked immunosorbent assay and compared with PASI score before and after treatment initiation or switching. Atopic dermatitis (AD) patients and disease-free individuals were used as controls. Expression of S100A8/A9 in SC of lesional skin of psoriasis patients was significantly higher than in non-lesional skin or AD skin. There was no significant difference of SC S100A8/A9 levels between PsV and PsA patients. The S100A8/A9 levels in SC of psoriasis patients were significantly positively correlated with the PASI score. When patients' skin lesions cleared (PASI clear) in response to treatment, expression of S100A8/A9 in SC was no longer detectable. S100A8/A9 protein levels in SC may be available as an objective, non-invasive biomarker of psoriasis activity to complement PASI scoring.

Clinical and Instrumental Exploration of Sensitive Skin in a Pediatric Population

Studies on sensitive skin pathophysiology in infants are challenging because most assessment methods require self-reporting of signs. In this study, we aimed to identify and characterize sensitive skin in children for the first time. A newly developed parent-reported questionnaire was used to recruit children with sensitive skin. This questionnaire was also tested on an adult group. Hydration, transepidermal water loss (TEWL), and inflammatory markers (cytokines, and polyunsaturated fatty acids (PUFAs)) were quantified. A total of 77 children and 20 adults (33 and 10 with sensitive skin, respectively) were recruited. The groups with sensitive skin had more clinical signs of skin dryness. Skin hydration was lower in children in the sensitive compared with the nonsensitive skin group. TEWL levels were similar between sensitive and nonsensitive subjects in both infant and adult groups. Sensitive skin exhibited higher levels of cytokines and proinflammatory PUFAs as well as lower levels of anti-inflammatory PUFAs. Sensitive skin syndrome was associated with normal skin barrier function but lower hydration in infants and children. The higher levels of proinflammatory markers suggest that sensitive skin is associated with low-level inflammation. It is hypothesized, for the first time, that PUFAs are involved in sensitive skin syndrome in infants.

IL-1 Family Antagonists in Mouse and Human Skin Inflammation

Interleukin (IL)-1 family cytokines initiate inflammatory responses, and shape innate and adaptive immunity. They play important roles in host defense, but excessive immune activation can also lead to the development of chronic inflammatory diseases. Dysregulated IL-1 family signaling is observed in a variety of skin disorders. In particular, IL-1 family cytokines have been linked to the pathogenesis of psoriasis and atopic dermatitis. The biological activity of pro-inflammatory IL-1 family agonists is controlled by the natural receptor antagonists IL-1Ra and IL-36Ra, as well as by the regulatory cytokines IL-37 and IL-38. These four anti-inflammatory IL-1 family members are constitutively and highly expressed at steady state in the epidermis, where keratinocytes are a major producing cell type. In this review, we provide an overview of the current knowledge concerning their regulatory roles in skin biology and inflammation and their therapeutic potential in human inflammatory skin diseases. We further highlight some common misunderstandings and less well-known observations, which persist in the field despite recent extensive interest for these cytokines.

Effects of petrolatum, a petrolatum depositing body wash and a regular body wash on biomarkers and biophysical properties of the stratum corneum

BACKGROUND

An important trend in the personal care industry involves the development of body wash products that not only clean the skin without damage but deposit conditioning ingredients to improve skin barrier function.

OBJECTIVE

The objective of this study was to develop skin biomarker measures to quantify the treatment effects of body wash products.

METHODS

We employed analysis of structural proteins (keratin 1,10,11 and involucrin), a natural moisturizing factor (pyrrolidone carboxylic acid) and an inflammatory mediator (IL-1ra/IL-1α) from adhesive discs with dry skin grading, TEWL and capacitance measurements to compare the effects of direct application of petrolatum, a high petrolatum depositing body wash, and a regular body wash on dry leg skin in a standard leg-wash treatment protocol.

RESULTS

High depositing body wash and petrolatum had positive effects on stratum corneum barrier function as judged by biomarker analysis, biophysical measurements and skin grading compared to the regular body wash product.

CONCLUSIONS

The results clearly indicate that a combination of biomarker and biophysical property measurements is effective for determining the skin benefits of moisturizing body wash products.

Tape strips in dermatology research

Tape strips have been used widely in dermatology research as a minimally invasive method to sample the epidermis, avoiding the need for skin biopsies. Most research has focused on epidermal pathology, such as atopic eczema, but there is increasing research into the use of tape strips in other dermatoses, such as skin cancer, and the microbiome. This review summarizes the technique of tape stripping, and discusses which dermatoses have been studied by tape stripping and alternative minimally invasive sampling methods. We review the number of tape strips needed from each patient and the components of the epidermis that can be obtained by tape stripping. With a focus on protein and RNA extraction, we address the techniques used to process tape strips. There is no optimal protocol to extract protein, as this depends on the abundance of the protein studied, its level of expression in the epidermis and its solubility. Many variables can alter the amount of protein obtained from tape strips, which must be standardized to ensure consistency between samples. No study has compared different RNA extraction techniques, but our own experience is that RNA yield is optimized by using 20 tape strips and the use of a cell scraper.

Skin tape sampling technique identifies proinflammatory cytokines in atopic dermatitis skin

BACKGROUND

Monitoring the effects of biologic therapies in skin diseases will benefit from alternative noninvasive skin sampling techniques to evaluate immune pathways in diseased tissue early and longitudinally.

OBJECTIVE

To establish a minimally invasive profiling of skin cytokines for diagnosis, therapeutic response monitoring, and clinical research in atopic dermatitis (AD) and other skin diseases, particularly in pediatric cohorts.

METHODS

We developed a novel method for cytokine profiling in the epidermis using skin tape strips (STSs) in a setting designed to maximize the efficiency of protein extraction from STSs. This method was applied to analyze STS protein extracts from the lesional skin of children having AD (n = 41) and normal, healthy controls (n = 22). A total of 20 cytokines were probed with the ultrasensitive Mesoscale multiplex cytokine assay.

RESULTS

A significant increase in interleukin (IL)-1b (P < .01), IL-18 (P < .001), and IL-8 (P < .001) with a decrease in IL-1a (P < .001) in the stratum corneum of AD lesional skin was found. Concurrently, an increase in markers associated with type 2 inflammatory response was readily detectable in AD lesional skin, including C-C motif chemokine ligand (CCL) 22, CCL 17, and thymic stromal lymphopoietin (TSLP). The levels of IL-1b, IL-18, and TSLP exhibited positive correlations with the AD severity index (Scoring AD index) and skin transepidermal water loss (TEWL), whereas an inverse correlation between IL-1a and Scoring AD index and IL-1a and TEWL was found. The levels of CCL17, CCL22, TSLP, IL-22, and IL-17a correlated with skin TEWL measurements.

CONCLUSION

Using minimally invasive STS analysis, we identified cytokine profiles easily sampled in AD lesional skin. The expression of these markers correlated with disease severity and reflected changes in TEWL in lesional skin. These markers suggest new response assessment targets for AD skin.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT03168113.

Establishing a measurement array to assess tissue tolerance during loading representative of prosthetic use

BACKGROUND

In the early stages of rehabilitation after primary amputation, residual limb soft tissues have not been mechanically conditioned to support load and are vulnerable to damage from prosthetic use. There is limited quantitative knowledge of skin and soft tissue response to prosthetic loading.

METHODS

An in-vivo protocol was developed to establish suitable measures to assess tissue tolerance during loading representative of early prosthesis use. Ten participants without amputation one participant with trans-tibial amputation were recruited, and pressure applied to their calf in increments from 20 to 60 mmHg. Measurements were recorded at relevant skin sites including interface pressures, transcutaneous oxygen (T_CPO₂) and carbon dioxide (T_CPCO₂) tensions and inflammatory biomarkers.

FINDINGS

At the maximum cuff pressure, mean interface pressures were between 66 and 74 mmHg, associated with decreased T_CPO₂ values. On the release of pressure, the ischaemic response was reversed. Significant upregulation (p < 0.05) in inflammatory biomarker IL-1α and its antagonist IL-1RA were observed at all sites immediately following loading.

INTERPRETATION

The protocol was successful in applying representative prosthetic loads to lower limb tissues and monitoring the physiological response, both in terms of tissue ischemia and skin inflammation. Results indicated that the measurement approaches were sensitive to changes in interface conditions, offering a promising approach to monitor tissue status for people with amputation.

[Function of Sacran as an Artificial Skin Barrier and the Development of Skincare Products]

Sacran, a large molecular-weight polysaccharide isolated from algae, is composed of 11 types of saccharides, including sulfate and carboxylic acid groups. Because of its unique structure, sacran can form a gel-like sheet in the presence of polyols such as 1,3-butanediol. In addition, those sacran gel-like sheets prevent the evaporation of water and the penetration of chemicals. The results of our previous study suggested that sacran can work as an artificial barrier against external stimuli such as air pollutants which increase the stress on humans. Topically applied sacran was localized at the surface of reconstructed human epidermal equivalents. Those results suggested that sacran inhibits excessive water evaporation from the skin and protects against environmental stimuli by forming an artificial barrier at the skin surface. Then, in a clinical study, we examined the activity of sacran in improving skin problems caused by an impaired epidermal barrier. First, we conducted a use test on a serum formulated with sacran on human volunteers who had impaired skin barrier function. The results showed that sacran provided excellent benefits to improve the maturation of corneocytes. These results suggest that sacran could play an important role in providing optimal skin conditions for keratinocytes to progress through their differentiation.

Fetal skin as a pro-inflammatory organ: Evidence from a primate model of chorioamnionitis

BACKGROUND

Intrauterine infection is a primary cause of preterm birth and fetal injury. The pro-inflammatory role of the fetal skin in the setting of intrauterine infection remains poorly characterized. Whether or not inflammation of the fetal skin occurs in primates remains unstudied. Accordingly, we hypothesized that: i) the fetal primate skin would mount a pro-inflammatory response to preterm birth associated pro-inflammatory agents (lipopolysaccharides from Escherichia coli, live Ureaplasma parvum, interleukin-1β) and; ii) that inhibiting interleukin-1 signaling would decrease the skin inflammatory response.

METHODS

Rhesus macaques with singleton pregnancies received intraamniotic injections of either sterile saline (control) or one of three pro-inflammatory agonists: E. coli lipopolysaccharides, interluekin-1β or live U. parvum under ultrasound guidance. A fourth group of animals received both E. coli lipopolysaccharide and interleukin-1 signaling inhibitor interleukin-1 receptor antagonist (Anakinra) prior to delivery. Animals were surgically delivered at approximately 130 days' gestational age.

RESULTS

Intraamniotic lipopolysaccharide caused an inflammatory skin response characterized by increases in interluekin-1β,-6 and -8 mRNA at 16 hours. There was a modest inflammatory response to U. parvum, but interleukin-1β alone caused no inflammatory response in the fetal skin. Intraamniotic Anakinra treatment of lipopolysaccharide-exposed animals significantly reduced skin inflammation.

CONCLUSIONS

Intraamniotic lipopolysaccharide and U. parvum were associated with modest increases in the expression of inflammatory mediators in primate fetal skin. Although administration of Interleukin-1β alone did not elicit an inflammatory response, lipopolysaccharide-driven skin inflammation was decreased following intraamniotic Anakinra therapy. These findings provide support for the role of the fetal skin in the development of the fetal inflammatory response.

Conditional knock out of N-WASP in keratinocytes causes skin barrier defects and atopic dermatitis-like inflammation

Neural-Wiskott Aldrich Syndrome Protein (N-WASP) is expressed ubiquitously and regulates actin cytoskeleton remodeling. In order to characterize the role of N-WASP in epidermal homeostasis and cutaneous biology, we generated conditional N-WASP knockout mouse using CK14-cre (cytokeratin 14) to ablate expression of N-WASP in keratinocytes. N-WASP^K14KO (N-WASP^fl/fl; CK14-Cre) mice were born following Mendelian genetics suggesting that N-WASP expression in keratinocytes is not essential during embryogenesis. N-WASP^K14KO mice exhibited stunted growth, alopecia, dry and wrinkled skin. The dry skin in N-WASP^K14KO mice is probably due to increased transepidermal water loss (TEWL) caused by barrier function defects as revealed by dye penetration assay. N-WASP^K14KO mice developed spontaneous inflammation in the neck and face 10 weeks after birth. Histological staining revealed thickening of the epidermis, abnormal cornified layer and extensive infiltration of immune cells (mast cells, eosinophils and T-lymphocytes) in N-WASP^K14KO mice skin compared to control mice. N-WASP^K14KO mice had higher serum levels of IL-1α, TNF-α, IL-6 and IL-17 compared to control mice. Thus our results suggest that conditional N-WASP knockout in keratinocytes leads to compromised skin barrier, higher infiltration of immune cells and hyperproliferation of keratinocytes due to increased production of cytokines highlighting the importance of N-WASP in maintaining the skin homeostasis.

Topical treatment with sacran, a sulfated polysaccharide from Aphanothece sacrum, improves corneocyte-derived parameters

Sacran, a polysaccharide isolated from Aphanothece sacrum (Suizenji-nori) alga, has unique characteristics in terms of its physiological properties and effects on the skin, and has recently become a focus of attention as a novel biomaterial. In a previous study, we reported the unique physical characteristics of sacran, which forms a gel-like film containing water in the presence of polyols. This film resists penetration by water and chemicals. We expected this unique physical characteristic to act as an artificial barrier upon the application of sacran to the skin. In the present study, we tested the efficacy of sacran application in healthy individuals who reported previous symptoms of dry or inflamed skin, to evaluate the potential benefits of sacran for skin care in patients with mild atopic dermatitis. Compared with placebo, sacran-containing serum did not significantly alter either the water content of the skin surface or transepidermal water loss. However, subjects using the serum showed improvements in corneocyte parameters including size, percentage of thick abrasion, ratio of SH to SS groups, ratio of interleukin (IL)-1 receptor antagonist to IL-1α, and carbonylated protein level. These results indicate that the sulfated polysaccharide sacran is an effective agent for improving or maintaining the skin conditions.

Role of interleukin 1 in atopic dermatitis

Interleukin-1 (IL-1) is a potent inflammatory cytokine that plays a central role in the innate immune response. IL-1 mediates the acute phase of inflammation by inducing local and systemic responses, such as pain sensitivity, fever, vasodilation, and hypotension. It also promotes the expression of adhesion molecules on endothelial cells, which allows the infiltration of inflammatory and immunocompetent cells into the tissues. The release of IL-1 from the epidermis after activation is a primary event that promotes inflammatory skin conditions through the induction of various cytokines, proinflammatory mediators, and adhesion molecules.

Efficacy of a new tonic containing urea, lactate, polidocanol, and glycyrrhiza inflata root extract in the treatment of a dry, itchy, and subclinically inflamed scalp

BACKGROUND/AIMS

Dry, itchy and inflamed scalp conditions are common and often associated with diseases such as atopic dermatitis or psoriasis. To improve these symptoms, we investigated the efficacy of a new tonic containing the active ingredients urea, lactate, polidocanol, and Glycyrrhiza inflata root extract, containing licochalcone A.

STUDY DESIGN/METHODS

30 subjects with dry and itchy scalp conditions underwent a randomized half-head study for 4 weeks, applying the leave-on tonic three times a week on one side of the scalp. Tonic effects on skin hydration, itching, lipids, microinflammation, and substantivity of tonic compounds were determined using corneometry, middle-infrared spectroscopy, direct analysis in real-time mass spectrometry, and enzyme-linked immunosorbent assay. Volunteers performed a self-assessment; changes in scalp condition were documented by in vivo microscopy.

RESULTS

After tonic treatment, scalp moisture was significantly increased, whereas scalp itching and tautness were significantly reduced. Results also demonstrated a high substantivity of urea and lactate on the scalp, an increase in triglyceride, and a decrease in free fatty acid levels. The amount of total lipids was unchanged. Analyses of scalp wash-ups verified a significant reduction in important pro-inflammatory markers.

CONCLUSION

Due to the actives urea, lactate, polidocanol, and the anti-inflammatory licochalcone A, the new scalp tonic exhibited excellent performance in alleviating scalp dryness, itching, microinflammation, and in normalizing disturbances of scalp lipids.

The infant skin barrier: can we preserve, protect, and enhance the barrier?

Infant skin is different from adult in structure, function, and composition. Despite these differences, the skin barrier is competent at birth in healthy, full-term neonates. The primary focus of this paper is on the developing skin barrier in healthy, full-term neonates and infants. Additionally, a brief discussion of the properties of the skin barrier in premature neonates and infants with abnormal skin conditions (i.e., atopic dermatitis and eczema) is included. As infant skin continues to mature through the first years of life, it is important that skin care products (e.g., cleansers and emollients) are formulated appropriately. Ideally, products that are used on infants should not interfere with skin surface pH or perturb the skin barrier. For cleansers, this can be achieved by choosing the right type of surfactant, by blending surfactants, or by blending hydrophobically-modified polymers (HMPs) with surfactants to increase product mildness. Similarly, choosing the right type of oil for emollients is important. Unlike some vegetable oils, mineral oil is more stable and is not subject to oxidation and hydrolysis. Although emollients can improve the skin barrier, more studies are needed to determine the potential long-term benefits of using emollients on healthy, full-term neonates and infants.

Filaggrin loss-of-function mutations are associated with enhanced expression of IL-1 cytokines in the stratum corneum of patients with atopic dermatitis and in a murine model of filaggrin deficiency

Background

Filaggrin (FLG) mutations result in reduced stratum corneum (SC) natural moisturizing factor (NMF) components and consequent increased SC pH. Because higher pH activates SC protease activity, we hypothesized an enhanced release of proinflammatory IL-1 cytokines from corneocytes in patients with atopic dermatitis (AD) with FLG mutations (AD_FLG) compared with that seen in patients with AD without these mutations (AD_NON-FLG).

Objectives

We sought to investigate SC IL-1 cytokine profiles in the uninvolved skin of controls and patients with AD_FLG versus patients with AD_NON-FLG. We also sought to examine the same profiles in a murine model of filaggrin deficiency (Flg^ft/Flg^ft [Flg^delAPfal] mice).

Methods

One hundred thirty-seven patients were studied. NMF levels were ascertained using confocal Raman spectroscopy; transepidermal water loss and skin surface pH were measured. IL-1α, IL-1β, IL-18, IL-1 receptor antagonist (IL-1RA), and IL-8 levels were determined in SC tape strips from 93 patients. All subjects were screened for 9 FLG mutations. Flg^ft/Flg^ft (Flg^delAPfal) mice, separated from maFlg^ft/maFlg^ft (flaky tail) mice, were used for the preparation and culture of primary murine keratinocytes and as a source of murine skin. RT-PCR was performed using primers specific for murine IL-1α, IL-1β, and IL-1RA.

Results

SC IL-1 levels were increased in patients with AD_FLG; these levels were inversely correlated with NMF levels. NMF values were also inversely correlated with skin surface pH. Skin and keratinocytes from Flg^ft/Flg^ft mice had upregulated expression of IL-1β and IL-1RA mRNA.

Conclusions

AD_FLG is associated with an increased SC IL-1 cytokine profile; this profile is also seen in a murine homologue of filaggrin deficiency. These findings might have importance in understanding the influence of FLG mutations on the inflammasome in the pathogenesis of AD and help individualize therapeutic approaches.

Interleukins, from 1 to 37, and interferon-γ: receptors, functions, and roles in diseases

Advancing our understanding of mechanisms of immune regulation in allergy, asthma, autoimmune diseases, tumor development, organ transplantation, and chronic infections could lead to effective and targeted therapies. Subsets of immune and inflammatory cells interact via ILs and IFNs; reciprocal regulation and counter balance among T(h) and regulatory T cells, as well as subsets of B cells, offer opportunities for immune interventions. Here, we review current knowledge about ILs 1 to 37 and IFN-γ. Our understanding of the effects of ILs has greatly increased since the discoveries of monocyte IL (called IL-1) and lymphocyte IL (called IL-2); more than 40 cytokines are now designated as ILs. Studies of transgenic or knockout mice with altered expression of these cytokines or their receptors and analyses of mutations and polymorphisms in human genes that encode these products have provided important information about IL and IFN functions. We discuss their signaling pathways, cellular sources, targets, roles in immune regulation and cellular networks, roles in allergy and asthma, and roles in defense against infections.

Stratum corneum TARC level is a new indicator of lesional skin inflammation in atopic dermatitis

BACKGROUND

Management of atopic dermatitis (AD) requires judging the symptoms of local skin lesions and prescribing a suitable treatment. However, no method has been established in which objective measures can be used to evaluate the severity of local symptoms. We established a method for measuring thymus and activation-regulated chemokine (TARC) levels in the stratum corneum (scTARC), and examined whether the scTARC can be used as an indicator of the severity of local skin lesions in patients with AD.

METHODS

Stratum corneum was obtained from patients with AD by tape-stripping, and scTARC was evaluated using a TARC-specific antibody followed by image analysis. The scTARC was examined to determine correlation with the severity of local skin lesions (the severity of erythema, edema/papule, oozing/crusts, excoriations, lichenification, and xerosis) as well as with the severity scoring of atopic dermatitis (SCORAD) index, serum TARC level, serum IgE level, serum lactate dehydrogenase (LDH) level, interleukin (IL)-4-producing T cell ratio (Th2 cell ratio), and blood eosinophil count.

RESULTS

The scTARC was correlated with the severity of local skin lesions, especially with the erythema, edema/papule, and oozing/crusts score. The scTARC in the most severe lesions was also correlated with the SCORAD index, serum TARC level, serum IgE level, and blood eosinophil count. The scTARC was not, however, correlated with the serum LDH level and Th2 cell ratio.

CONCLUSION

An immunofluorescent technique combined with tape-stripping was used to measure scTARC. The scTARC can be used as an indicator of the severity of local acute inflammation in patients with AD.

Influence of tumour necrosis factor-α polymorphism-308 and atopy on irritant contact dermatitis in healthcare workers

BACKGROUND

Chronic irritant hand dermatitis is an issue for healthcare workers and may negatively impact infection control.

OBJECTIVES

We examined the effects of a G to A transition at position -308 on the tumour necrosis factor-α (TNF-α) gene on chronically damaged skin of healthcare workers during exposure and recovery from repetitive hand hygiene, after intensive treatment, and on the irritant response in normal skin.

PATIENTS/MATERIALS/METHODS

In 68 healthcare workers with irritant hand dermatitis, we genotyped TNF-α-308 and measured the epidermal response via quantitative digital imaging, erythema, dryness, and barrier integrity.

RESULTS

Excess hand erythema decreased with hand hygiene exposure and increased during time off for AA/GA genotypes, but had opposite effects for GG. AA/GA had smaller reductions in dryness with lotion treatment and larger reductions in excess erythema than GG. The atopic diathesis and heightened neurosensory irritation resulting from water and lactic acid significantly influenced the responses. Repeated exposure to water and sodium lauryl sulfate (0.05, 0.1%) produced higher erythema in normal skin for AA/GA than for GG.

CONCLUSIONS

This study provides evidence that the TNF-α polymorphism at -308 and an atopic history impact the severity of irritation and recovery from exposure and response to treatment for common hand skin products in both chronic irritant hand dermatitis and normal skin.

Stratum corneum cytokines, structural proteins, and transepidermal water loss: effect of hand hygiene

BACKGROUND/AIMS

There are few reports on the cytokine response to high frequency hand hygiene among health care workers (HCWs) in an occupational setting. We have observed significant skin barrier compromise consistent with chronic irritant contact dermatitis in HCWs. We hypothesized that repetitive hand hygiene would activate the epidermal inflammatory cascade and lead to changes in structural proteins and cytokines.

METHODS

Keratin 6, keratin 1, 10, 11, involucrin, IL1alpha, TNFalpha, IL8, IL1RA, and IL10 were analyzed from the SC using bead-based arrays. Knuckle and dorsum samples were evaluated for HCWs (n=23) before and after repetitive hand hygiene and compared with those of age-matched non-wet workers (n=23) without hand skin irritation. Erythema, dryness, and barrier integrity were measured.

RESULTS

Transepidermal water loss (TEWL) was higher for HCWs but unchanged with exposure. IL1alpha and TNFalpha were highest in control volar forearm. IL1alpha, TNFalpha, and IL8 were significantly lower in HCWs than controls despite higher erythema, dryness, and TEWL. Decreases in keratin 1, 10, 11, increases in keratin 6, and reduction in IL1alpha, TNFalpha, and IL8 were seen after hand hygiene.

CONCLUSION

This preliminary study showed significantly lower SC biomarker levels in HCW compared with controls and regional differences between the hand and forearm. Exposure to repetitive hand hygiene results in substantial chronic skin irritation without time for barrier recovery between work periods. The impact on SC structural proteins and cytokines has many commonalities with chronic inflammation, although mechanistic questions remain.

Biomarkers of epidermal innate immunity in premature and full-term infants

Epidermal innate immunity is a complex process involving a balance of pro- and anti-inflammatory cytokines, structural proteins, and specific antigen presenting cells occurring against a background of neuroendocrine modulators such as cortisol. In this study, a multiplex array system was used to simultaneously determine multiple molecular factors critical for development of epidermal innate immune function from the skin surface of premature and term infants, healthy adults, and vernix caseosa. Samples were analyzed for Keratin 1,10,11, Keratin 6, involucrin, albumin, fibronectin and cortisol, and cytokines IL-1, TNFalpha, IL-6, IL-8, MCP1, IP10, IFNgamma, and IL-1 receptor antagonist. Keratin 1,10,11 was decreased and involucrin was increased in infants versus adults. All infants had elevated IL1alpha and reduced TNFalpha versus adults. IL-6, IL-8, and MCP1 were significantly increased in premature versus term infants and adults. Skin surface cortisol and albumin were significantly elevated in premature infants. The biomarker profile in premature infants was unique with differences in structural proteins, albumin, and cytokines IL-6, IL-1beta, IL-8, and MCP1. The higher infant IL1alpha may be associated with skin barrier maturation. The significant elevations in skin surface cortisol for preterm infants may reflect a neuroendocrine response to the stress of premature birth.

Transcutaneous immunization using common chemicals

Transcutaneous immunization, topical application of vaccines on skin, provides several advantages over needle based immunization. However, simple topical application of vaccines does not generate sufficient immune response due to limited transport of vaccines across the stratum corneum of skin. Here we report that chemicals used in common skin products can enhance the immunogenicity of topically applied antigens. Six hundred formulations of commonly used chemicals were screened systematically for their potency (delivery of antigen) in vitro. A selected subset of these formulations was subsequently tested for their adjuvanticity (activation of immune response) in vitro. Lead formulations were tested in vivo for their ability to generate antibody titers against topically applied ovalbumin, a model antigen. Lead formulations were significantly more effective in generating anti-ovalbumin IgG titers. Our results demonstrate that chemical formulations can be successfully used to deliver antigens and that such formulations can be rationally designed by combinatorial screening of individual chemical components.

Location-related differences in structure and function of the stratum corneum with special emphasis on those of the facial skin

Between the two different kinds of the skin covering the body, the glabrous skin is found only on the palmo-plantar surface because of its rather simple function to protect the underlying living tissue with its remarkably thick stratum corneum (SC) from strong external force and friction. Thus, its barrier function is extremely poor. In contrast, the hair-bearing skin covers almost all over the body surface regardless of the presence of long hair or vellus hair. In regard to its SC, many dermatologists and skin scientists think that it is too thin to show any site-specific differences, because the SC is just present as an efficient barrier membrane to protect our body from desiccation as well as against the invasion by external injurious agents. However, there are remarkable regional differences not only in the living skin tissue but also even in such thin SC reflecting the function of each anatomical location. These differences in the SC have been mostly disclosed with the advent of non-invasive biophysical instruments, particularly the one that enables us to measure transepidermal water loss (TEWL), the parameter of the SC barrier function, and the one that evaluates the hydration state of the skin surface, the parameter of the water-holding capacity of the SC that brings about softness and smoothness to the skin surface. These in vivo instrumental measurements of the SC have disclosed the presence of remarkable differences in the functional properties of the SC particularly between the face and other portions of the body. The SC of the facial skin is thinner, being composed of smaller layers of corneocytes than that of the trunk and limbs. It shows unique functional characteristics to provide hydrated skin surface but relatively poor barrier function, which is similar to that observed in retinoid-treated skin or to that of fresh scar or keloidal scars. Moreover, there even exist unexpected, site-dependent differences in the SC of the facial skin such as the forehead, eyelid, cheek, nose and perioral regions, although each location occupies only a small area. Between these locations, the cheek shows the lowest TEWL in contrast to the perioral region that reveals the highest one. Moreover, these features are not static but change with age particularly between children and adults and maybe also between genders. Among various facial locations, the eyelid skin is distinct from others because its SC is associated with poor skin surface lipids and a thin SC cell layer composed of large corneocytes that brings about high surface hydration state but poor barrier function, whereas the vermillion borders of the lips that are covered by an exposed part of the oral mucosa exhibit remarkably poor barrier function and low hydration state. Future studies aiming at the establishment of the functional mapping in each facial region and in other body regions will shed light on more delicate site-dependent differences, which will provide us important information in planning the strategy to start so called tailor-made skin care for each location of the body.

Cellular and molecular mechanisms in atopic dermatitis

Atopic dermatitis (AD) is a pruritic inflammatory skin disease associated with a personal or family history of allergy. The prevalence of AD is on the rise and estimated at approximately 17% in the USA. The fundamental lesion in AD is a defective skin barrier that results in dry itchy skin, and is aggravated by mechanical injury inflicted by scratching. This allows entry of antigens via the skin and creates a milieu that shapes the immune response to these antigens. This review discusses recent advances in our understanding of the abnormal skin barrier in AD, namely abnormalities in epidermal structural proteins, such as filaggrin, mutated in approximately 15% of patients with AD, epidermal lipids, and epidermal proteases and protease inhibitors. The review also dissects, based on information from mouse models of AD, the contributions of the innate and adaptive immune system to the pathogenesis of AD, including the effect of mechanical skin injury on the polarization of skin dendritic cells, mediated by keratinocyte-derived cytokines such as thymic stromal lymphopoietin (TSLP), IL-6, and IL-1, that results in a Th2-dominated immune response with a Th17 component in acute AD skin lesions and the progressive conversion to a Th1-dominated response in chronic AD skin lesions. Finally, we discuss the mechanisms of susceptibility of AD skin lesions to microbial infections and the role of microbial products in exacerbating skin inflammation in AD. Based on this information, we discuss current and future therapy of this common disease.

The immune system and atopic dermatitis

Atopic dermatitis (AD) is a chronic inflammatory skin disease with a complex pathogenesis. It is clinically well-defined and represents one manifestation of the atopic state, along with asthma, food allergy and/or allergic rhinitis. Within the last several decades, there has been much evidence to support the contribution of immune mechanisms in the pathogenesis of AD. It has also been documented that the prevalence of all atopic disease, including AD, has been increasing, although the environmental factors that may be contributing to this increase are not clearly defined. A better understanding of the underlying immunopathogenesis of AD should aid in better clinical management and development of new treatment options.

Overexpression of IL-1alpha in skin differentially modulates the immune response to scarification with vaccinia virus

Transepidermal inoculation of vaccinia virus (VV), or scarification, has been used effectively for the induction of specific and long-lasting immunity to smallpox and is superior to other routes of immunization. Scarification of individuals with atopic skin disease or immune deficiency, however, can lead to persistent viral replication and result in significant morbidity and mortality. These effects of scarification presumably reflect the unique immunological properties of skin and the immune cells resident in, or recruited to, the site of inoculation. To explore these phenomena, we utilized transgenic mice engineered to overexpress IL-1alpha, a critical mediator of cutaneous inflammation, in the epidermis. Following scarification with VV, both transgenic and wild-type mice develop local pox. At high doses of VV, IL-1alpha transgenic mice recruited immune cells to the inoculation site more rapidly and demonstrated enhanced T-cell and humoral immune responses. At limiting doses, however, IL-1alpha transgenic mice could effectively control virus replication without formation of pox lesions or activation of a memory response. This study suggests that IL-1 might be useful as an adjuvant to enhance antiviral immunity and promote safer vaccination strategies; however, understanding the balance of IL-1 effects on innate and adaptive immune functions will be critical to achieve optimal results.

Cytokines at different stratum corneum levels in normal and sodium lauryl sulphate-irritated skin

BACKGROUND/PURPOSE

Cytokines play an important role in inflammatory and repair processes occurring in the skin. The objectives of this study were to determine the amounts of cytokines and protein isolated by tape stripping in the different layers of the stratum corneum (SC), and to compare normal skin with skin exposed in vivo to the irritant sodium lauryl sulphate (SLS).

METHODS

In eight volunteers, we determined the amount of total and soluble protein and also interleukin-1alpha (IL-1alpha) in pooled tape strips obtained from the upper, intermediate and lower parts of the SC. Three different types of tape were compared (Diamond , D-squame or Sentega tape). In a separate study, 20 volunteers were repeatedly exposed to 0.1% SLS over a 3-week period. The amounts of IL-1alpha, IL-1RA and IL-8 in strips obtained from the three different SC levels of SLS-exposed skin were compared with an unexposed site.

RESULTS

For normal skin, the amounts of soluble protein and IL-1alpha were similar for the three tapes. Diamond tape showed the highest yield of total protein. The total protein yield per strip decreased to lower SC levels, whereas soluble protein and IL-1alpha normalized by soluble protein did not change across the SC. After SLS induced skin irritation, IL-1alpha decreased and IL-1RA and IL-8 increased at increasing depth into the SC.

CONCLUSIONS

Tape stripping is a suitable method to determine SC cytokine concentrations in human skin. With this technique, it is possible to study changes in cytokine concentrations at different SC layers after skin irritation.

Aberrant expression of histo-blood group A type 3 antigens in vascular endothelial cells in inflammatory sites

Histo-blood group ABH antigens are widely distributed in human tissues. The epitopes of ABH antigens are carried by at least four different peripheral core isotypes of internal carbohydrate backbones (type 1-4). Each type of ABH antigen is expressed tissue specifically, and aberrant expression of ABH antigens is often observed during oncogenesis. We immunohistochemically examined the expression of A type 3 antigens in wounded and diseased skin tissues (A and AB blood groups). In uninjured skin, the expression of A type 3 antigens was restricted to the eccrine sweat gland. In addition to the sweat glands, A type 3 antigens were found in vascular endothelial cells of the wound sites. The extent of A type 3 antigens expression related to postinfliction intervals. A significantly higher expression rate of A type 3 antigens in endothelial cells was also observed in diseased skin, suggesting that inflammation might induce A type 3 antigen expression in endothelial cells. Double-color immunofluorescence staining of the specimens showed that von Willebrand factor (vWF) was a core-protein of A type 3 determinants aberrantly expressed in endothelial cells in inflamed tissues, suggesting that aberrant expression of A type 3 antigens is involved in stabilization of vWF in inflammation.

A simple and non-invasive visualization for assessment of carbonylated protein in the stratum corneum

BACKGROUND/PURPOSE

Stratum corneum (SC) is the interface of body and environment and is continuously exposed to oxidative stress, resulting in oxidative modification of proteins. Consequent carbonylated proteins (CPs) have so far been labeled with 2,4-dinitrophenyl (DNP) hydrazine and subsequently detected with anti-DNP antibody. We developed a simpler, non-invasive method to assess CP level in the SC and applied it to following research.

METHODS

SC was collected by adhesive tape stripping and its carbonyl groups were labeled with fluorescein-5-thiosemicarbazide (FTZ). The staining image was observed by fluorescence microscopy and the average fluorescence intensity of the SC extracted from the image was calculated as stratum corneum carbonylated protein (SCCP) level.

RESULTS

By reaction with FTZ, carbonyl groups in the SC could be detected easily. Relatively strong fluorescence was observed in exfoliating scales. Lipid removal from the SC in vitro or in vivo did not show any change in fluorescence intensity, suggesting that carbonyl groups were mainly derived from proteins, not from lipids. SCCP level was higher in the upper layer than the lower layer, and higher in the cheek (sun-exposed) than the inside of upper arm (unexposed), positively correlated with age especially in male cheek, positively correlated with transepidermal water loss, negatively correlated with water content, and showed a subtle correlation with sebum level. On the other hand, SC collected by cyanoacrylate resin and labeled with FTZ revealed strong fluorescence around the pores in the cheek and on the grooves in the upper arm, suggesting the role of sebum in the generation of SCCP.

CONCLUSION

SCCP was assessed in a simple and non-invasive method, and suggested to be a novel indicator that reflects some aspect of skin condition.

Stratum corneum cytokines and skin irritation response to sodium lauryl sulfate

Little is known about cytokines involved in chronic irritant contact dermatitis. Individual cytokine profiles might explain at least part of the differences in the individual response to irritation. Our objective was to investigate the relation between baseline stratum corneum (SC) cytokine levels and the skin response to a single and a repeated irritation test. This study also aimed to determine changes in SC cytokine levels after repeated irritation. Transepidermal water loss (TEWL) and erythema were measured in 20 volunteers after single 24-hr exposure to 1% sodium lauryl sulfate (SLS), and during and after repeated exposure to 0.1% SLS over a 3-week period. SC cytokine levels were measured from an unexposed skin site and from the repeatedly exposed site. Interleukin (IL)-1alpha decreased by 30% after repeated exposure, while IL-1RA increased 10-fold and IL-8 increased fourfold. Baseline IL-1RA and IL-8 values were predictors of TEWL and erythema after single exposure (r = 0.55-0.61). 6 subjects showed barrier recovery during repeated exposure. Baseline IL-1RA and IL-8 levels are likely to be indicators of higher skin irritability after single exposure to SLS. Barrier repair in some of the subjects might explain the lack of agreement between the TEWL response after single and repeated irritation.