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, IL1α, TNFα, 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. IL1α and TNFα were highest in control volar forearm. IL1α, TNFα, 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 IL1α, TNFα, 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.     

CCL7 contributes to the TNF‐alpha‐dependent inflammation of lesional psoriatic skin

Chemokines are small chemotactic proteins that have a crucial role in leukocyte recruitment into tissue. Targeting these mediators has been suggested as a potential therapeutic option in inflammatory skin diseases such as psoriasis. Using quantitative RT‐PCR, we found CCL7, a chemokine ligand known to interact with multiple C‐C chemokine receptors, to be markedly increased in lesional psoriasis as opposed to atopic dermatitis, lichen planus, non‐lesional psoriatic and normal control skin. Surprisingly, this increase in CCL7 mRNA expression exceeded that of all other chemokines investigated, and keratinocytes and dermal blood endothelial cells were identified as its likely cellular sources. In an imiquimod‐induced psoriasis‐like mouse model, CCL7 had a profound impact on myeloid cell inflammation as well as on the upregulation of key pro‐psoriatic cytokines such as CCL20, IL‐12p40 and IL‐17C, while its blockade led to an increase in the antipsoriatic cytokine IL‐4. In humans receiving the TNF‐α‐blocker infliximab, CCL7 was downregulated in lesional psoriatic skin already within 16 hours after a single intravenous infusion. These data suggest that CCL7 acts as a driver of TNF‐α‐dependent Th1/Th17‐mediated inflammation in lesional psoriatic skin.     

TNF‐α and IL‐10 gene polymorphisms show a weak association with pemphigus vulgaris in the Slovak population

Backround Pemphigus vulgaris is a rare chronic autoimmune disease of skin and mucous membranes, with several cytokines participating in its development. The role of their gene polymorphisms in susceptibility to the disease is, however, not fully understood. Objective The aim of our case‐control study was to investigate whether some of 22 single nucleotide polymorphisms (SNPs) in 13 cytokine genes (IL‐1α, IL‐1β, IL‐1RI, IL‐1Ra, IL‐4Rα, IL‐12, IFN‐γ, TGF‐β1, TNF‐α, IL‐2, IL‐4, IL‐6 and IL‐10) are associated with pemphigus vulgaris in the Slovak population. Methods DNA samples were obtained from 34 pemphigus vulgaris patients and 140 healthy controls of Slovak origin. Cytokine gene SNPs were determined using the polymerase chain reaction with sequence‐specific primers (PCR‐SSP) method. Results We found a weak association between pemphigus vulgaris and polymorphic variants in TNF‐α and IL‐10 genes only, with haplotypes TNF‐α–308G/–238G and IL‐10 –1082A/–819C/–592C being significantly overrepresented in pemphigus vulgaris patients (TNF‐α GG: 94.12% vs. 82.86%, P = 0.0216; IL‐10 ACC: 44.12% vs. 30.00%, P = 0.0309). Conclusions Our preliminary results suggest that certain TNF‐α and IL‐10 gene polymorphisms might contribute to genetic susceptibility to pemphigus vulgaris; however, their overall impact on disease development will be rather limited.     

Effects of anti‐TNF‐α agents on circulating endothelial‐derived and platelet‐derived microparticles in psoriasis

Psoriasis involves TNF‐α secretion leading to release of microparticles into the bloodstream. We investigated the effect of TNF blockers on microparticles levels before and after treatment in patients (twenty treated by anti‐TNF‐α agents and 6 by methotrexate) with severe psoriasis. Plasmatic microparticles were labelled using fluorescent monoclonal antibodies and were analysed using cytometry. Three months later, 70% of patients treated with anti‐TNF‐α agents achieved a reduction in PASI score of at least 75%. The clinical improvement in patients treated with anti‐TNF‐α agents was associated with a significant reduction of the mean number of platelet microparticles (2837/μl vs 1849/μl, P = 0.02) and of endothelial microparticles (64/μl vs 22/μl, P = 0.001). Microparticles are significantly decreased in psoriatic patients successfully treated by anti‐TNF‐α. Microparticles levels as circulating endothelial cells represent signs of endothelial dysfunction and are elevated in psoriasis. Then, TNF blockade may be effective to reduce cardiovascular risk through the reduction of circulating microparticles.     

IL6Rα function in myeloid cells modulates the inflammatory response during irritant contact dermatitis

Irritant contact dermatitis (ICD) is characterized by epidermal hyperplasia, infiltration of leucocytes into lesional skin and inflammatory cytokine release. The cellular infiltrate during ICD comprises primarily cells of the myeloid lineage. Our group has previously shown that the cytokine IL‐6 confers a protective effect to lesional skin during ICD. How IL‐6Rα function in myeloid cells is involved in the inflammatory response during ICD is, however, unknown. In the present study, utilizing a chemical model of ICD, it is shown that mice with a myeloid‐specific knockout of the IL‐6Rα (IL‐6Rα^Δmyeloid) display an exaggerated inflammatory response to benzalkonium chloride (BKC) and Jet propellant‐8 (JP8) fuel, two well‐characterized irritants relative to littermate control. Results from immunohistochemical and flow cytometric analyses revealed that IL‐6Rα^Δmyeloid mouse skin displayed increased epidermal hyperplasia and inflammatory monocyte influx into lesional skin but lower numbers of resident macrophages relative to littermate controls after irritant exposure. Multiplex immunoassay revealed significantly higher levels of pro‐inflammatory cytokines IL‐1α and TNF‐α, but reduced expression of chemokine proteins including CCL2‐5, CCL7, CCL11, CXCL1 and CXCL10 in IL‐6Rα^Δmyeloid mouse skin relative to littermate control following irritant exposure. These results highlight a previously unknown role of IL‐6Rα function in myeloid cells in modulating the inflammatory response and myeloid population dynamics during ICD.     

Increased alpha‐melanocyte‐stimulating hormone (α‐MSH) levels and melanocortin receptors expression associated with pigmentation in an NC/Nga mouse model of atopic dermatitis

Please cite this paper as: Increased alpha‐melanocyte‐stimulating hormone (α‐MSH) levels and melanocortin receptors expression associated with pigmentation in an NC/Nga mouse model of atopic dermatitis. Experimental Dermatology 2010; 19: 132–136. Abstract: Patients with a specific subtype of atopic dermatitis (AD) display particular patterns of pigmentation, such as ripple pattern pigmentation on the neck, pigmented macules on the lip and diffuse pigmentation. However, the mechanism underlying these patterns has not been determined. The purpose of our research is to investigate the factors influencing this type of pigmentation in AD. We observed that AD model mice (NC/Nga mice) displayed an increase in the number of 3, 4‐dihydroxyphenylalanine (Dopa)‐positive melanocytes in the epidermis and intestine (jejunum and colon) while in the inflammatory state. The plasma levels of alpha‐melanocyte‐stimulating hormone (α‐MSH) and adrenocoticotropin (ACTH) also increased in NC/Nga mice with dermatitis. Furthermore, the expression of melanocortin receptor 5 and melanocortin receptor 1 (MC1R) increased in the skin, and melanocortin receptor 3 (MC3R) expression increased in the intestine. However, the changes in the Dopa‐positive cells of conventional NC/Nga mice were not induced by treatment with either agouti (an MC1R antagonist) or agouti‐related protein (an MC3R antagonist). These results indicate that the pigmentation of AD is related to increased levels of α‐MSH, MC1R (in the skin) and MC3R (in the intestines).     

3‐O‐Laurylglyceryl ascorbate improves the development of sensitive skin through the reduction of oxidative stress

Skin sensitivity is a serious problem for many people, and it can be induced by various factors such as UV irradiation, physical and mental stresses, air pollution, dry air and so on. Skin dryness triggered by UV and dry air is one of the most important causes inducing the development of sensitive skin, and it has been reported that oxidative stress contributes to skin dryness. In this study, we investigated whether treatment with 3‐O‐laurylglyceryl ascorbate (VC‐3LG), which is an amphipathic ascorbic acid derivative, can suppress the development of sensitive skin. The results demonstrate that VC‐3LG restores the expression levels of interleukin‐1α, nerve growth factor and matrix metalloprotease‐9 in the dry skin models of reconstructed human epidermal equivalents (RHEEs) and in H₂O₂‐treated keratinocytes. In addition, VC‐3LG suppresses the dendrite elongation of nerve cells induced in RHEEs by dry skin conditions and by H₂O₂ treatment of keratinocytes. Therefore, we consider that treatment of the skin with VC‐3LG is an effective approach to improve the development of sensitive skin.     

Tropisetron via α7 nicotinic acetylcholine receptor suppresses tumor necrosis factor‐α‐mediated cell responses of human keratinocytes

Tropisetron is a serotonin receptor (5‐HT‐R)‐modulating agent and approved as an antiemetic for patients undergoing chemotherapy. In the gut, it acts via specific serotonin receptors, 5‐HT₃‐R, to elicit its beneficial effects against nausea. We investigated whether tropisetron can affect inflammatory cell responses of human primary epidermal keratinocytes (NHK) which are key cells in the regulation of skin homoeostasis. Tropisetron significantly and dose‐dependently suppressed tumor necrosis factor (TNF)‐α‐mediated mRNA expression and protein secretion of interleukin (IL)‐6 and IL‐8 in these cells. This effect of tropisetron was independent of p65/NF‐κB as shown by various NF‐κB signal transduction read‐outs. Importantly, the anti‐inflammatory tropisetron effect on NHK was neither mediated by 5‐HT₃‐R nor 5‐HT₄‐R since these receptors were absent in NHK. In contrast, NHK expressed α7 nicotinic acetylcholine receptors (α7nAchR) which previously were found to bind tropisetron. The α7nAchR antagonist α‐bungarotoxin neutralized, whereas AR‐R17779, a specific α7nAchR agonist, mimicked the suppressive effect of tropisetron on TNF‐α‐mediated IL‐6 and IL‐8 expression in NHK. Our findings suggest that tropisetron and probably other α7nAchR‐activating agents could be useful for the future therapy of inflammatory skin diseases.     

Cutaneous events during treatment of chronic inflammatory joint disorders with anti‐tumour necrosis factor alpha: a cross‐sectional study

Background Anti‐tumour necrosis factors (anti‐TNF) are more and more used, but the rate of skin adverse events is not known. Objective The aim was to assess the number of skin infections and other dermatoses in patients treated with anti‐TNFα. Patients and methods One hundred eighty‐seven patients suffering from rheumatoid arthritis or ankylosing spondylitis underwent a dermatological exam. Patients with anti‐TNF were compared with those without this treatment in a prospective transversal study. Results Among them, 59 patients were treated with anti‐TNFα and steroids were prescribed in 100 cases. There was no difference in the prevalence of skin infections or eczema or tumours. Skin drug reactions were observed in six patients. Infections by dermatophytes appear very frequent, approaching 70% in both groups. Conclusions This study shows that skin infections (or other skin diseases) are not more frequent in these patients. No differences were observed in infections (bacterial fungal, parasital or viral), tumours, psoriasis or the manifestations of atopic dermatitis. Nonetheless, a long‐term survey might be interesting, especially about skin tumours.     

CD4+ T cells producing interleukin (IL)‐17, IL‐22 and interferon‐γ are major effector T cells in nickel allergy

Background It has been suggested that interleukin (IL)‐17 and IL‐22 play important roles in the elicitation of human allergic contact dermatitis; however, the frequencies of T cell subtypes producing IL‐17 and IL‐22 in human allergic contact dermatitis are unknown. Objectives To determine the frequencies of CD4⁺, CD8⁺ and γδ T cells producing IL‐17, IL‐22 and interferon (IFN)‐γ in the blood and skin from nickel‐allergic patients. Patients/materials/methods Blood samples were collected from 14 patients and 17 controls, and analysed by flow cytometry. Biopsies were taken from 5 patients and 6 controls, and analysed by immunohistochemistry and flow cytometry of skin lymphocytes. Results We found an increased frequency of γδ T cells in the blood, but no differences in the distribution of cytokine‐producing CLA⁺ T cell subtypes in nickel‐allergic patients as compared with controls. In nickel‐allergic patients, there was massive cellular infiltration dominated by CD4⁺ T cells producing IL‐17, IL‐22 and IFN‐γ in nickel‐challenged skin but not in vehicle‐challenged skin. Conclusion CD4⁺ T cells producing IL‐17, IL‐22 and IFN‐γ are important effector cells in the eczematous reactions of nickel‐induced allergic contact dermatitis in humans.     

Effects of Coccoloba uvifera L. on UV‐stimulated melanocytes

Background: Exposure to ultraviolet (UV) radiation induces generation of reactive oxygen species, production of proinflammatory cytokines and melanocyte‐stimulating hormone (MSH) as well as increase in tyrosinase activity. The potential photoprotective effects of Coccoloba uvifera extract (CUE) were evaluated in UV‐stimulated melanocytes. Methods: Human epidermal melanocytes were used as an in vitro model to evaluate the effects of CUE on the production interleukin‐1α (IL‐1α), tumor necrosis factor α (TNF‐α), and α‐MSH under basal and UV‐stimulated conditions. Antioxidant and anti‐tyrosinase activities were also evaluated in membrane lipid peroxidation and mushroom tyrosinase assay, respectively. Results: Coccoloba uvifera L. showed antioxidant and anti‐tyrosinase activities and also inhibited the production of IL‐1α, TNF‐α and α‐MSH in melanocytes subjected to UV radiation (P<0.01). Moreover, CUE inhibited the activity of tyrosine kinase in cell culture under basal and UV radiation conditions (P<0.001), corroborating the findings of the mushroom tyrosinase assay. Conclusion: This study supports the photoprotective potential of CUE.     

Safety and tolerability of a body wash and moisturizer when applied to infants and toddlers with a history of atopic dermatitis: results from an open-label study

Abstract: Improving skin barrier function and moisturizing without irritation are important components of managing patients with atopic dermatitis. This study evaluated the safety and tolerability of a body wash and moisturizer regimen for infants and toddlers with atopic dermatitis. This was an open‐label study involving 56 children (3–36 months old) with a history of atopic dermatitis. The skin care regimen (Cetaphil Restoraderm Skin Restoring Body Wash and Cetaphil Restoraderm Skin Restoring Moisturizer; Galderma Laboratories, L.P.) was used at least once daily, but no more than twice daily, for 4 weeks. The primary variable of interest was the worst postbaseline scores for local tolerability (expressed as success or failure) using a 4‐point scale for each component (erythema, edema, scaling and dryness, rash, and signs of discomfort upon application). Assessments of moisture content of the stratum corneum and transepidermal water loss were also performed. Fifty‐three children completed the study. The percentage of subjects with no erythema increased from 33.9% to 50.0% by Week 4. The percentage of subjects with no scaling or dryness increased from 58.9% to 85.2% at Week 4. A statistically significant increase in corneometry from baseline (p < 0.001) and a statistically significant decrease in transepidermal water loss (p = .009) were observed. The body wash and moisturizer regimen was safe and well tolerated and improved hydration and skin barrier function in infants and toddlers as young as 3 months of age with a history of atopic dermatitis.     

Human skin melanocyte migration towards stromal cell‐derived factor‐1α demonstrated by optical real‐time cell mobility assay: modulation of their chemotactic ability by α‐melanocyte‐stimulating hormone

To identify potential regulators of normal human melanocyte behaviour, we have developed an in vitro human melanocyte migration assay, using the optically accessible, real‐time cell motility assay device TAXIScan. Coating of the glass surface with an extracellular matrix that served as scaffolding molecule was essential to demonstrate efficient melanocyte migration. Among several chemokines tested, stromal cell‐derived factor (SDF)‐1α/CXCL12 was the most effective driver of human normal skin melanocytes. Incubation of melanocytes with α‐melanocyte‐stimulating hormone (MSH) before the assay specifically enhanced CXCR4 expression and consequently chemotaxis towards SDF‐1α/CXCL12. These results suggest that α‐MSH acts on melanocytes to produce melanin as well as stimulates the cells to migrate to the site where they work through CXCR4 up‐regulation, which is a new dynamic mode of action of α‐MSH on melanocyte physiology.     

Tumour necrotizing factor-alpha promoter and GST-T1 genotype predict skin allergy to chromate in cement workers in Taiwan

BACKGROUND: Construction workers exposed to cement are known to suffer from occupational contact dermatitis because of chromate sensitization. It is not clear whether certain genotypes are associated with increased susceptibility of chromate sensitization in those workers regularly exposed to cement. OBJECTIVE: The objective of this study was to determine the genotypes predisposing workers to cement-induced contact dermatitis. METHODS: A total of 153 current cement workers who had regular contact with cement were telephone interviewed for skin problems in the past 12 months, work exposure, and personal protection. A dermatologist examined their skin and conducted patch test with common skin allergens. Blood samples were donated for genotypic determination by polymerase chain reaction-based assays for GST-T1, GST-M1 (null/non-null), tumour necrosis factor (TNF) alpha promoter-308G/A, and interleukin (IL) 4-590C/T. RESULT: High percentage of dermatitis was noted in the 153 workers examined, which was correlated with reported skin problems. By patch testing, construction workers had a high-prevalence rate (12%) of sensitivity to chromate. Sensitivity to chromate was significantly associated with TNF alpha promoter-308 heterozygous (GA) as compared with GG genotype (odds ratio 3.9, 95% confidence interval 1.1-13.2), as well as with GST-T1 null genotype (odds ratio 5.5, 95% confidence interval 1.4-36.2), but neither the GST-M1 nor the IL-4 genotypes. CONCLUSION: It is concluded that among workers frequently exposed to cement in Southern Taiwan, those with TNF alpha promoter-308 heterozygous (GA) genotype or GST-T1 null genotype had increased risk of chromate sensitization.     

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

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

Therapeutic potential of topically administered γ‐AlOOH on 2,4‐dinitrochlorobenzene‐induced atopic dermatitis‐like lesions in Balb/c mice

Boehmite (γ‐AlOOH) has a wide range of applications in a variety of industrial and biological fields. However, little is known about its potential roles in skin diseases. The current study investigated its effect on atopic dermatitis (AD). Following characterization, cytotoxicity, pro‐inflammatory response and oxidative stress associated with boehmite were assessed, using TNF‐α‐induced keratinocytes and mast cells. In addition, therapeutic effects of boehmite, topically administered to Balb/c mice induced by 2,4‐dinitrochlorobenzene (DNCB), were evaluated. Expression of cytokines (TLSP, IL‐25 and IL‐33) and the generation of ROS from keratinocytes induced by TNF‐α were significantly inhibited by boehmite without affecting cell viability. MAPKs (ERK, JNK and p38) required for cytokine expression were suppressed by boehmite treatment. Up‐regulation of cytokines (TSLP, IL‐4, IL‐5, IL‐13, RANTES) in human mast cells treated with phorbol 12‐myristate 13‐acetate and calcium ionophore was also suppressed by boehmite. Boehmite improved the AD severity score, epidermal hyperplasia and transepidermal water loss in DNCB‐induced AD‐like lesions. Moreover, Th2‐mediated cytokine expression, mast cell hyperplasia and destruction of the skin barrier were improved by boehmite treatment. Overall, we demonstrated that boehmite may potentially protect against AD.     

Study of pro‐ and anti‐inflammatory cytokine profile in the patients with parthenium dermatitis

Background: Parthenium dermatitis is a common airborne allergic contact dermatitis induced by exposures to the weed Parthenium hysterophorus. The disease manifests as itchy erythematous papules, papulovesicular and plaque lesions on exposed areas of the body. Objectives: The aim of this study was to show the alterations in pro/anti‐inflammatory cytokines in parthenium dermatitis. Methods: The study included 50 patients with parthenium dermatitis confirmed by patch testing using aqueous extracts of P. hysterophorus and 50 age‐matched healthy controls. The levels of pro‐inflammatory [tumour necrosis factor‐α (TNF‐α), interleukin (IL)‐6, IL‐8, and IL‐17] and anti‐inflammatory (IL‐4 and IL‐10) cytokines were estimated by commercially available high sensitivity enzyme‐linked immunosorbent assay (ELISA) kits. Results: All the dermatitis patients showed significantly (P < 0.001) elevated levels of TNF‐α, IL‐6, IL‐8, and IL‐17 levels as compared to healthy controls. In contrast, the anti‐inflammatory cytokine IL‐4 showed an insignificant decrease (P < 0.217) and a decrease in level of IL‐10 was statistically significant (0.001) compared with controls. Conclusions: The present study suggests the involvement of pro‐inflammatory cytokines in the pathogenesis of parthenium dermatitis. A decrease in levels of anti‐inflammatory cytokines was demonstrated, which could not downregulate pro‐inflammatory cytokines in parthenium dermatitis.