Recent advances in atopic dermatitis and psoriasis: genetic background, barrier function, and therapeutic targets

Skin colonization by Staphylococcus aureus in hemodialysis patients with pruritus and the effect of Staphylococcus aureus-secreted α-toxin on filaggrin expression

Staphylococcus aureus (S. aureus) commonly reside on human skin in residents in long-term care facilities, yet its colonization and impact on the skin of hemodialysis (HD) patients have yet to be studied. The aim of the present study was to investigate the colonization of S. aureus on the skin of pruritic and non-pruritic HD patients, and the influence of S. aureus and S. aureus-secreted α-toxin on skin barrier function-related protein expression. In this study, a higher relative S. aureus count in pruritic HD patients compared to non-pruritic HD patients and healthy subjects were revealed by real-time polymerase chain reaction. S. aureus and α-toxin decreased mRNA and protein expression levels of aryl hydrocarbon receptor (AHR), ovo-like transcriptional repressor 1 (OVOL1), and filaggrin (FLG) in keratinocytes. In addition, anti-alpha-hemolysin (anti-hla) was used as an α-toxin neutralizer, and it successfully abrogated S. aureus-induced AHR, OVOL1, and FLG mRNA and protein expression downregulation. Mechanistically, α-toxin could decrease FLG activity by preventing the recruitment of AHR to the FLG promoter region. In conclusion, pruritic HD patients had higher S. aureus colonization, with S. aureus-secreted α-toxin suppressing FLG expression through the AHR-FLG axis.

The Features of Shared Genes among Transcriptomes Probed in Atopic Dermatitis, Psoriasis, and Inflammatory Acne: S100A9 Selection as the Target Gene

BACKGROUND

Atopic dermatitis (AD), psoriasis (PS), and inflammatory acne (IA) are well-known as inflammatory skin diseases. Studies of the transcriptome with altered expression levels have reported a large number of dysregulated genes and gene clusters, particularly those involved in inflammatory skin diseases.

OBJECTIVE

To identify genes commonly shared in AD, PS, and IA that are potential therapeutic targets, we have identified consistently dysregulated genes and disease modules that overlap with AD, PS, and IA.

METHODS

Microarray data from AD, PS, and IA patients were downloaded from Gene Expression Omnibus (GEO), and identification of differentially expressed genes from microarrays of AD, PS, and IA was conducted. Subsequently, gene ontology and gene set enrichment analysis, detection of disease modules with known disease-associated genes, construction of the protein-protein interaction (PPI) network, and PPI sub-mapping analysis of shared genes were performed. Finally, the computational docking simulations between the selected target gene and inhibitors were conducted.

RESULTS

We identified 50 shared genes (36 up-regulated and 14 down-regulated) and disease modules for each disease. Among the shared genes, 20 common genes in PPI network were detected such as LCK, DLGAP5, SELL, CEP55, CDC20, RRM2, S100A7, S100A9, MCM10, AURKA, CCNB1, CHEK1, BTC, IL1F7, AGTR1, HABP4, SERPINB13, RPS6KA4, GZMB, and TRIP13. Finally, S100A9 was selected as the target gene for therapeutics. Docking simulations between S100A9 and known inhibitors indicated several key binding residues, and based on this result, we suggested several cannabinoids such as WIN-55212-2, JZL184, GP1a, Nabilone, Ajulemic acid, and JWH-122 could be potential candidates for a clinical study for AD, PS, and IA via inhibition of S100A9-related pathway.

CONCLUSION

Overall, our approach may become an effective strategy for discovering new disease candidate genes for inflammatory skin diseases with a reevaluation of clinical data.

NMR-based metabolomic analysis for the effects of moxibustion on imiquimod-induced psoriatic mice

ETHNOPHARMACOLOGICAL RELEVANCE

Moxibustion is a traditional medical intervention of traditional Chinese medicine. It refers to the direct or indirect application of ignited moxa wool made of mugwort leaves to acupuncture points or other specific parts of the body for either treating or preventing diseases. Moxibustion has been proven to be effective in treating skin lesions of psoriasis.

AIM OF THE STUDY

This study was performed to elucidate molecular mechanisms underlying the effects of moxibustion treatment on imiquimod-induced psoriatic mice.

MATERIALS AND METHODS

We established an imiquimod (IMQ)-induced psoriatic mice (Model) and assessed the effects of moxibustion (Moxi) treatment on skin lesions of psoriatic mice by the PASI scores and expressions of inflammation-related factors relative to normal control mice (NC). We then performed nuclear magnetic resonance (NMR)-based metabolomic analysis on the skin tissues of the NC, Model and Moxi-treated mice to address metabolic differences among the three groups.

RESULTS

Moxi mice showed reduced PASI scores and decreased expressions of the pro-inflammatory cytokines IL-8, IL-17A and IL-23 relative to Model mice. Compared with the Model group, the NC and Moxi groups shared 9 characteristic metabolites and 4 significantly altered metabolic pathways except for taurine and hypotaurine metabolism uniquely identified in the NC group. To a certain extent, moxibustion treatment improved metabolic disorders of skin lesions of psoriatic mice by decreasing glucose, valine, asparagine, aspartate and alanine-mediated cell proliferation and synthesis of scaffold proteins, alleviating histidine-mediated hyperproliferation of blood vessels, and promoting triacylglycerol decomposition.

CONCLUSIONS

This study reveals the molecular mechanisms underlying the effects of moxibustion treatment on the skin lesions of psoriasis, potentially improving the clinical efficacy of moxibustion.

Elevation of IgE in patients with psoriasis: Is it a paradoxical phenomenon?

Immunoglobulin E (IgE) elevation is a hallmark of allergic conditions such as atopic dermatitis (AD). The pathogenesis of AD is typically associated with high levels of IL-4 and IL-13 produced by activated T helper 2 (Th2) cells. Psoriasis, on the other hand, is an inflammatory skin disease mainly driven by Th17 cells and their related cytokines. Although the immunopathologic reactions and clinical manifestations are often easily distinguished in the two skin conditions, patients with psoriasis may sometimes exhibit AD-like manifestations, such as elevated IgE and persistent pruritic lesions. Given the fact that the effective T cells have great plasticity to re-differentiate in response to innate and environmental factors, this unusual skin condition could be a consequence of a cross-reaction between distinct arms of T-cell and humoral immunity. Here we review the literature concerning the roles of IgE in the development of AD and psoriasis, showing that elevated IgE seems to be an important indicator for this non-typical psoriasis.

Evidence for Lysosomal Dysfunction within the Epidermis in Psoriasis and Atopic Dermatitis

Atopic dermatitis and psoriasis are frequent chronic inflammatory skin diseases. Autophagy plays a substantial role in the homeostasis of an organism. Loss or impairment of autophagy is associated with multiple diseases. To investigate the possibility that autophagy plays a role in atopic dermatitis and psoriasis, we investigated the levels of key ATG proteins in human skin specimens as well as in primary human epidermal keratinocytes exposed to inflammatory stimuli in vitro. Although TNF-α facilitated the induction of autophagy in an initial phase, it reduced the levels and enzymatic activities of lysosomal cathepsins in later time periods, resulting in autophagy inhibition. Therefore, TNF-α appears to play a dual role in the regulation of autophagy. The relevance of these in vitro findings was supported by the observation that the protein levels of cathepsins D and L are decreased in both psoriasis and atopic dermatitis skin specimens. Taken together, this study suggests that TNF-α blocks autophagy in keratinocytes after long-term exposure, a mechanism that may contribute to the chronicity of inflammatory diseases of the skin and, perhaps, of other organs.

Microneedle-assisted genome editing: A transdermal strategy of targeting NLRP3 by CRISPR-Cas9 for synergistic therapy of inflammatory skin disorders

We report a dissolvable microneedle (MN) patch that can mediate transdermal codelivery of CRISPR-Cas9-based genome-editing agents and glucocorticoids for the effective treatment of inflammatory skin disorders (ISDs). The MN is loaded with polymer-encapsulated Cas9 ribonucleoprotein (RNP) targeting NLRP3 and dexamethasone (Dex)-containing polymeric nanoparticles. Upon insertion into the skin, the MN can be dissolved quickly to release two types of nanoformulations, which are subsequently internalized by keratinocytes and surrounding immune cells to exert their therapeutic effects in the inflammatory subcutaneous layers. Thus, the MN-enabled transdermal codelivery of Cas9 RNP nanocomplexes and Dex nanoparticles result in the disruption of subcutaneous intracellular NLRP3 inflammasomes, which is demonstrated to be critical to alleviate skin inflammations and contributes to glucocorticoid therapy in mouse models of ISDs, including psoriasis and atopic dermatitis. Our study offers innovative insights into the rational design of transdermal delivery systems and defines an effective therapeutic option for the treatment of ISDs.

Predictors of Systemic Exposure to Topical Crisaborole: A Nonlinear Regression Analysis

Crisaborole ointment, 2%, is a nonsteroidal phosphodiesterase 4 inhibitor for the treatment of mild to moderate atopic dermatitis. Results from 2 randomized, double-blind, vehicle-controlled phase 3 studies showed that twice-daily crisaborole in children and adults with mild to moderate atopic dermatitis was efficacious and well tolerated. Initial pharmacokinetics (PK) studies of crisaborole indicated absorption with measurable systemic levels of crisaborole. The current analysis was conducted to correlate steady-state systemic exposure parameters with ointment dose and identify covariates impacting PK parameters in healthy participants and patients with atopic dermatitis or psoriasis. A nonlinear regression analysis was conducted using ointment dose and noncompartmental PK parameters at steady state (area under the curve [AUC_ss ] and maximum concentration [C_max,ss ]). PK data were available from 244 participants across 6 clinical studies (AUC_ss , N = 239; C_max,ss , N = 241). Disease condition had the greatest impact on slope in both models, corresponding to 2.5-fold higher AUC_ss and C_max,ss values at a given ointment dose in patients with atopic dermatitis or psoriasis relative to healthy participants. Disease severity, race/ethnicity, and sex had marginal effects on AUC_ss and C_max,ss . Systemic exposures were similar across age groups ≥2 years of age when the same percentage of body surface area (%BSA) was treated. Predictive performance plots for AUC_ss and C_max,ss for different age groups demonstrated that the models adequately describe the observed data. Model predictions indicated that systemic exposure to crisaborole in pediatric patients (2-17 years) is unlikely to exceed systemic exposure in adults (≥18 years), even at the highest possible ointment dose corresponding to a %BSA of 90.

The Role of Th17-Related Cytokines in Atopic Dermatitis

T helper-17 (Th17) cells, which mainly produce IL-17, are associated with development of various autoimmune diseases such as rheumatoid arthritis, inflammatory bowel diseases, multiple sclerosis, and psoriasis. IL-17 and related cytokines are therapeutic targets of these diseases. In atopic dermatitis (AD), Th2 cytokines such as IL-4 and IL-13 are regarded to be the main player of the disease; however, Th17 cytokines are also expressed in AD skin lesions. Expression of IL-22 rather than IL-17 is predominant in AD skin, which is contrary to cytokine expression in psoriasis skin. Relatively low IL-17 expression in AD skin can induce relatively low antimicrobial peptide expression, which may be a reason why bacterial infection is frequently seen in AD patients. Failure of clinical trials for investigating the efficacy of anti-IL-12/23 p40 in AD has suggested that IL-17 expressed in skin lesions should not be the main player but a bystander responding to barrier dysfunction.

Restoration of calcium-induced differentiation potential and tight junction formation in HaCaT keratinocytes by functional attenuation of overexpressed high mobility group box-1 protein

HaCaT cells have been widely used as undifferentiated epidermal keratinocytes, since these non-tumorigenic cells can be readily maintained in conventional medium and partly retain epidermal differentiation potential upon stimulation with high concentration of calcium. In contrast to primary epidermal keratinocytes, however, these cells never form tight junction (TJ), a specific structure in highly differentiated keratinocytes, solely by the differentiation stimulation. Here, we show that HaCaT cells secrete a considerable amount of high mobility group box-1 protein (HMGB1), one of major inflammatory mediator, which appeared to be responsible, at least in part, for such aberrant differentiation response. So far, inhibition of c-Jun N-terminal kinase (JNK) in high calcium medium has been supposed to be the only way to induce TJ formations in HaCaT cells; however, SP600125, a potent inhibitor of JNK showed cytostatic effects and clearly attenuated epidermal differentiation and stratification. In contrast, dipotassium glycyrrhizate (GK2), a soluble analogue of HMGB1-blocker Glycyrrhizin, down-regulated interferon-β, a typical inflammatory cytokine induced by secreted HMGB1, and accelerated differentiation responses to the calcium treatment in these cells. In addition, GK2-treatmenrt resulted in the formation of double cell layers in cultured HaCaT cells, where the stratified upper cells transiently accumulated TJ proteins at the cell-cell contact sites. These results highlight the importance of attenuation of secreted HMGB1-signals in cultured HaCaT cells for studies of functional keratinocytes.

Human disorders associated with inflammation and the evolving role of natural products to overcome

Inflammation is a biological function which triggered after the mechanical tissue disruption or from the responses by the incidence of physical, chemical or biological negotiator in body. These responses are essential act provided by the immune system during infection and tissue injury to maintain normal tissue homeostasis. Inflammation is a quite complicated process at molecular level with the involvement of several proinflammatory expressions. Several health problems are associated with prolonged inflammation, which effects nearly all major to minor diseases. The molecular and epidemiological studies jagged that the inflammation is closely associated with several disorders with their specific targets. It would be great achievement for human health around the world to overcome on inflammation. Mostly used anti-inflammatory drugs are at high risk of side effects and also expensive. Hence, the plant-based formulations gained a wide acceptance by the public and medical experts to treat it. Due to extensive dispersal, chemical diversity and systematically established biological potentials of natural products have induced renewed awareness as a gifted source for medications. However, today's urgent need to search for cheaper, more potent and safe anti-inflammatory medications to overcome on current situation. The goal of this review to compile an update on inflammation, associated diseases, molecular targets, inflammatory mediators and role of natural products. The entire text concise the involvement of various cytokines in pathogenesis of various human disorders. This assignment discussed about 321 natural products with their promising anti-inflammatory potential discovered during January 2009 to December 2018 with 262 citations.

Neonatal gut colonization by Staphylococcus aureus strains with certain adhesins and superantigens is negatively associated with subsequent development of atopic eczema

BACKGROUND

Insufficient early immune stimulation may predispose to atopic disease. Staphylococcus aureus, a skin and gut colonizer, produces the B-cell mitogen protein A and T-cell-activating superantigens. Early gut colonization by S. aureus strains that possess the superantigens encoded by the enterotoxin gene (egc) cluster and elastin-binding protein is negatively associated with development of atopic eczema.

OBJECTIVES

To investigate (i) whether these findings could be replicated in a second birth cohort, FARMFLORA, and (ii) whether nasal colonization by S. aureus also relates to subsequent atopic eczema development.

METHODS

Faecal samples and nasal swabs from infants in the FARMFLORA birth cohort (n = 65) were cultured for S. aureus. Individual strains were distinguished by random amplified polymorphic DNA and assessed for adhesin and superantigen gene carriage by polymerase chain reaction. Atopic eczema at 18 months of age was related to nasal and gut S. aureus colonization patterns during the first 2 months of life (well before onset of eczema).

RESULTS

Staphylococcus aureus colonization per se was unrelated to subsequent eczema development. However, gut S. aureus strains from the infants who subsequently developed atopic eczema less frequently carried the ebp gene, encoding elastin-binding protein, and superantigen genes encoded by egc, compared with strains from children who remained healthy. Nasal colonization by S. aureus was less clearly related to subsequent eczema development.

CONCLUSIONS

The results precisely replicate our previous observations and may suggest that mucosal colonization by certain S. aureus strains provides immune stimulation that strengthens the epithelial barrier and counteracts the development of atopic eczema.

Is the Fractional Laser Still Effective in Assisting Cutaneous Macromolecule Delivery in Barrier-Deficient Skin? Psoriasis and Atopic Dermatitis as the Disease Models

PURPOSE

Most of the investigations into laser-assisted skin permeation have used the intact skin as the permeation barrier. Whether the laser is effective in improving cutaneous delivery via barrier-defective skin is still unclear.

METHODS

In this study, ablative (Er:YAG) and non-ablative (Er:glass) lasers were examined for the penetration of peptide and siRNA upon topical application on in vitro skin with a healthy or disrupted barrier.

RESULTS

An enhanced peptide flux (6.9 fold) was detected after tape stripping of the pig stratum corneum (SC). A further increase of flux to 11.7 fold was obtained after Er:YAG laser irradiation of the SC-stripped skin. However, the application of Er:glass modality did not further raise the flux via the SC-stripped skin. A similar trend was observed in the case of psoriasiform skin. Conversely, the flux was enhanced 3.7 and 2.6 fold after treatment with the Er:YAG and the Er:glass laser on the atopic dermatitis (AD)-like skin. The 3-D skin structure captured by confocal microscopy proved the distribution of peptide and siRNA through the microchannels and into the surrounding tissue.

CONCLUSIONS

The fractional laser was valid for ameliorating macromolecule permeation into barrier-disrupted skin although the enhancement level was lower than that of normal skin.

Association of CDKAL1 Polymorphisms with Early-Onset Atopic Dermatitis in Koreans

Background

Atopic dermatitis (AD) has increased in frequency to rates as high as 20% for children in developed countries. AD is one of the most common childhood diseases and has a complex etiology involving genetic and environmental factors. Thus, a broad understanding of genetic background is needed for early diagnosis of AD.

Objective

Identification of candidate functional genetic variants associated with early-onset AD in Koreans.

Methods

Whole-exome sequencing (WES) was performed in three families. Sanger sequencing was used to validate detected variants in 112 AD patients and 61 controls.

Results

Functional variants were filtered by WES, and then variants related to allergic immune diseases were selected through a literature search. Two candidate non-synonymous single-nucleotide polymorphisms of CDKAL1 (rs77152992) and ERBB2 (rs1058808) were identified, c.1226C>T, p.Pro409Leu, c.3463C>G, and p. Pro1170Ala respectively. A case-control study was performed to determine whether rs77152992 and rs1058808 are candidate risk factors for early-onset AD. rs77152992 was significantly associated with early-onset AD (odds ratio [OR], 0.42; 95% confidence interval [CI], 0.21~0.83; p=0.0133) in allele frequencies. The CC genotype of CDKAL1 had significantly increased risk of AD (OR, 2.16; 95% CI, 1.0~4.6; p=0.0475). rs1058808 had no correlation with AD. Total eosinophil count was significantly increased in AD patients with the CC genotype of CDKAL1 (rs77152992).

Conclusion

CDKAL1 (rs77152992) and ERBB2 (rs1058808) were deemed functionally interesting based on WES. Our case-control study suggests that the CC genotype of rs77152992 may be associated with increased eosinophil counts. It may enhance the risk of early-onset AD.

Blocking TGF-β type 1 receptor partially reversed skin tissue damage in experimentally induced atopic dermatitis in mice

Animals with impaired transforming growth factor (TGF)-β1 signaling developed spontaneous lethal autoimmune inflammationand autoimmune diseases. Moreover, evidence for modified TGF-β signaling in atopic dermatitis (AD) exists. Therefore, the goal of this study was to determine whether SB-431542, a potent and selective inhibitor of the TGF-β type 1 receptor (TGF-βR1), could attenuate such a severe reaction in mice. In addition, the molecular underpinnings the possible protective effects were also investigated. Repeated epicutaneous application of DNCB was performed on the ear and shaved dorsal skin of miceto induce AD-like symptoms and skin lesions. SB-431542 (1 mg/kg) was given by intra-peritoneal injection three times weekly for 3 weeks to assess the anti-pruritic effects. Serum levels of TGF-β1, TGF-βR1, latency-associated peptide (LAP), tumor necrosis factor (TNF)-α, interleukin (IL)-1β and IL-6 were assessed by ELISA. Moreover, the gene expression of TNF-α, IL-1β and IL-6 were determined. Apoptotic pathway was evaluated by measuring the activity of caspase-3 and by staining skin sections with anti-caspase-3 antibodies. We found that SB-431542 alleviated DNCB-induced AD-like symptoms as quantified by skin lesion,dermatitisscore, ear thickness and scratching behavior. In parallel, SB-431542 blocked DNCB-induced elevation in serum levels of TNF-α, TGF-β1, TGF-βR1, LAP, IL-1β, IL-6 and IgE. The collective results indicate that SB-431542 partially suppresses DNCB-induced AD in micevia reduction of TGF-β1 signaling pathway associated with inhibition of inflammation and apoptosis.

Risks for comorbidity in children with atopic disorders: an observational study in Dutch general practices

OBJECTIVE

This study aimed to investigate both atopic and non-atopic comorbid symptoms and diseases in children with physician-diagnosed atopic disorders (atopic eczema, asthma and allergic rhinitis).

METHODS

All children aged 0-18 years listed in a nationwide primary care database (the Netherlands Institute for Health Services Research-Primary Care Database) with routinely collected healthcare data in 2014 were selected. Children with atopic disorders were matched on age and gender with non-atopic controls within the same general practice. A total of 404 International Classification of Primary Care codes were examined. Logistic regression analyses were performed to examine the associations between the presence of atopic disorders and (non-)atopic symptoms and diseases by calculating ORs.

RESULTS

Having one of the atopic disorders significantly increased the risk of having other atopic-related symptoms, even if the child was not registered as having the related atopic disorder. Regarding non-atopic comorbidity, children with atopic eczema (n=15 530) were at significantly increased risk for (infectious) skin diseases (OR: 1.2-3.4). Airway symptoms or (infectious) diseases (OR: 2.1-10.3) were observed significantly more frequently in children with asthma (n=7887). Children with allergic rhinitis (n=6835) had a significantly distinctive risk of ear-nose-throat-related symptoms and diseases (OR: 1.5-3.9). Neither age nor gender explained these increased risks.

CONCLUSION

General practitioners are not always fully aware of relevant atopic and non-atopic comorbidity. In children known to have at least one atopic disorder, specific attention is required to avoid possible insufficient treatment and unnecessary loss of quality of life.

A molecular mechanism for IL-4 suppression of loricrin transcription in epidermal keratinocytes: implication for atopic dermatitis pathogenesis

Skin barrier defects play an important role in atopic dermatitis (AD) pathogenesis. Loricrin, an important barrier protein suppressed in human AD, is down-regulated by IL-4 in keratinocytes. However, the molecular mechanism is unknown. Since loricrin transcription requires p300/CBP, and Stat6 also recruits this common coactivator for its stimulated factors, we hypothesize that IL-4-activated Stat6 competes for the available endogenous p300/CBP, leading to loricrin transcription inhibition. First, we showed that loricrin is suppressed in the skin of IL-4 transgenic mice, an AD mouse model. In human keratinocytes, IL-4 down-regulation of loricrin is abrogated by a pan-Jak inhibitor, suggesting that the Jak-Stat pathway is involved. To further investigate the downstream molecular mechanism, we transfected HaCat cells with a loricrin promoter and then treated them with either IL-4 or vehicle. Not surprisingly, IL-4 greatly suppressed the promoter activity. Interestingly, this suppression was prevented when we knocked down Stat6, indicating that Stat6 participates in IL-4 regulation of loricrin. A Stat6-specific inhibitor confirmed the knockdown study. Finally, IL-4 suppression of loricrin was reversed with transfection of a CBP expression vector in a dose-dependent manner. Taken together, for the first time, we delineate a molecular mechanism for IL-4 down-regulation of loricin expression in human keratinocytes, which may play an important role in AD pathogenesis.

Adult Atopic Dermatitis with Comorbid Atopic Disease is Associated with Increased Risk of Infections: A Population-Based Cross-Sectional Study

Introduction

Atopic dermatitis (AD) is related to other atopic diseases asthma and allergic rhinitis. It is known that those with asthma or allergic rhinitis have impaired immune responses that may predispose them to infections. This study sought to determine whether adult AD is associated with systemic infections, and whether association is strengthened in those with AD plus another atopic disease.

Methods

This cross-sectional study obtained information from adults in the 2010 and the 2012 National Health Interview Survey (NHIS). The primary exposure was history of AD without or with an additional atopic disease, asthma or allergic rhinitis. Self-reported systemic infections were the primary outcomes. Survey logistic regression was performed and adjusted odds ratios (aOR) reported.

Results

AD in NHIS 2010 was associated with increased risk of sinusitis [aOR (95% CIs): 1.65 (1.42, 1.91), P < 0.001], head or chest cold [1.31 (1.12, 1.52), P < 0.001], and gastrointestinal illness [2.39 (1.97, 2.89), P < 0.001], and in NHIS 2012, pneumonia/influenza [1.73 (1.54, 1.95), P < 0.001], strep throat/tonsillitis [1.72 (1.54, 1.92), P < 0.001], sinusitis [1.77 (1.54, 2.02), P < 0.001], head or chest cold [1.49 (1.33, 1.67), P < 0.001], and infectious disease [2.66 (2.20, 3.21), P < 0.001]. An increase in atopic disease mirrored an increase in number of infectious outcomes and was statistically significant in the combined dataset (P < 0.001).

Conclusion

The associations between AD and AD plus another atopic disease with systemic infections suggest that an underlying immune defect may be contributing to microbial susceptibility. Further studies are warranted to understand the burden of infectious disease in this population.

Electronic supplementary material

The online version of this article (doi:10.1007/s13555-017-0172-7) contains supplementary material, which is available to authorized users.

Genetic and Environmental Influences on General Skin Traits: Healthy Twins and Families in Korea

Family study can provide estimates of overall genetic influences on a particular trait because family relationships provide accurate measures of average genetic sharing. However, evidence of genetic contributions to skin phenotypes is limited, which may preclude genetic studies to identify genetic variants or to understand underlying molecular biology of skin traits. This study aimed to estimate genetic and environmental contributions to selected dermatologic phenotypes, that is, to melanin index, sebum secretion, and skin humidity level in a Korean twin-family cohort. We investigated more than 2,000 individuals from 486 families, including 388 monozygotic twin pairs and 82 dizygotic twin pairs. Variance component method was used to estimate genetic influences in terms of heritability. Heritability of skin melanin index, sebum secretion, and skin humidity (arm and cheek) were estimated to be 0.44 [95% CI 0.38-0.49], 0.21 [95% CI 0.16-0.26], 0.13 [95% CI 0.07-0.18], and 0.11 [95% CI 0.06-0.16] respectively, after adjusting for confounding factors. Our findings suggest that genetics play a major role on skin melanin index, but only mild roles on sebum secretion and humidity. Sebum secretion and skin humidity are controlled predominantly by environmental factors notably on shared environments among family members. We expect that our findings add insight to determinants of common dermatologic traits, and serve as a reference for biologic studies.

Association of Macrophage Migration Inhibitory Factor Polymorphisms with Total Plasma IgE Levels in Patients with Atopic Dermatitis in Korea

The macrophage migration inhibitory factor (MIF) gene is located on human chromosome 22q11.2 and is linked to atopic phenotypes. Plasma MIF and log [total IgE] levels are significantly elevated in atopic dermatitis (AD) patients. The aim of this study was to evaluate the relationship between two MIF polymorphisms, −173 G to C and −794 CATT_5–8, and total plasma IgE levels in AD patients in Korea. We performed PCR-RFLP analysis in 178 AD patients and 80 control subjects to determine whether MIF SNPs are associated with susceptibility to AD. Plasma total IgE and MIF levels were determined, and then logistic regression analyses were performed to determine the associations between a SNP or haplotype and plasma total IgE or MIF levels. The −173 G/C polymorphism, located in the MIF promoter, was significantly associated with AD; the odds ratios (ORs) for the CC homozygotes and GC heterozygotes were 9.3 and 2.5, respectively. The MIF C/5-CATT and the MIF C/7-CATT haplotypes were significantly associated with AD; the ORs for the MIF C/5-CATT and MIF C/7-CATT haplotypes were 9.7 and 4.5, respectively. Log [total IgE] levels were highly associated with the MIF −794 7-CATT polymorphism. Notably, the MIF C/7-CATT haplotype was associated with a decrease in plasma log [total IgE] levels in a gene dose-dependent manner. Although log [MIF] levels were not associated with the MIF polymorphisms, the frequencies of the MIF C/5-CATT haplotype-containing genotypes decreased in order of MIF levels. Our results demonstrate that MIF promoter polymorphisms in the −173 C allele and the MIF C/5-CATT and C/7-CATT haplotypes were significantly associated with an increased risk for AD. In particular, the −794 7-CATT locus and the MIF C/7-CATT haplotype were significantly associated with decreased total IgE levels in the plasma, suggesting that these polymorphisms might be a marker for intrinsic AD rather than extrinsic AD that shows high total IgE levels and presence of allergen-specific IgE.

iTRAQ-based quantitative proteomics of stratum corneum of dandruff scalp reveals new insights into its aetiology and similarities with atopic dermatitis

The study aimed at detecting differentially expressed proteins in the stratum corneum of dandruff versus non-dandruff scalps to better understand dandruff aetiology. iTRAQ-based quantitative proteomic analysis revealed a total of 68 differentially expressed biomarkers. A detailed analysis of their known physiological functions provided new insights into the affected metabolic pathways of a dandruff scalp. Dandruff scalp showed (1) profound changes in the expression and maturation of structural and epidermal differentiation related proteins, that are responsible for the integrity of the skin, (2) altered relevant factors that regulate skin hydration, and (3) an imbalanced physiological protease-protease inhibitor ratio. Stratum corneum proteins with antimicrobial activity, mainly those derived from sweat and sebaceous glands were also found modified. Comparing our data with those reported for atopic dermatitis revealed that about 50 % of the differentially expressed proteins in the superficial layers of the stratum corneum from dandruff and atopic dermatitis are identical.

Activation of myeloid dendritic cells, effector cells and regulatory T cells in lichen planus

Background

Lichen planus (LP) is a chronic mucocutaneous inflammatory disease. Evaluating the balance between regulatory T cells and effector T cells could be useful for monitoring the proinflammatory profile of LP. Therefore, this study aimed to assess populations of dendritic cells (DCs) and regulatory and effector T cells in peripheral blood samples collected from patients with LP to evaluate the polyfunctionality of T cells upon toll-like receptor (TLR) activation.

Methods

Peripheral blood mononuclear cells collected from 18 patients with LP and 22 healthy control subjects were stimulated with agonists of TLR4, TLR7, TLR7/TLR8 or TLR9. Frequencies of circulating IFN-α⁺ plasmacytoid DCs (pDCs); TNF-α⁺ myeloid DCs (mDCs); regulatory T cells (Tregs); and IL-17-, IL-10-, IL-22-, TNF-, and IFN-γ-secreting T cells were assessed via flow cytometry.

Results

The frequencies of regulatory CD4⁺ and CD8⁺CD25⁺Foxp3⁺CD127^low/− T cells and TNF-α⁺ mDCs were induced following activation with TLR4, TLR7 and TLR8 agonists in the LP group. Moreover, increased baseline frequencies of CD4⁺IL-10⁺ T cells and CD8⁺IL-22⁺ or IFN-γ⁺T cells were found. In the LP group, TLR4 activation induced an increased frequency of CD4⁺IFN-γ⁺ T cells, while TLR7/8 and staphylococcal enterotoxin B (SEB) activation induced an increased frequency of CD8⁺ IL-22⁺ T cells. An increased frequency of polyfunctional CD4⁺ T cells that simultaneously secreted 3 of the evaluated cytokines (not including IL-10) was verified upon TLR7/8/9 activation, while polyfunctional CD8⁺ T cells were already detectable at baseline.

Conclusions

TLR-mediated activation of the innate immune response induced the production of proinflammatory mDCs, Tregs and polyfunctional T cells in patients with LP. Therefore, TLR activation has an adjuvant role in inducing both innate and adaptive immune responses.

Electronic supplementary material

The online version of this article (doi:10.1186/s12967-016-0938-1) contains supplementary material, which is available to authorized users.

Clinical categories of exaggerated skin reactions to mosquito bites and their pathophysiology

Mosquito bites are skin irritating reactions, which usually resolve spontaneously without intensive medical care. However, in certain situations, mosquito bites may form a more vicious reaction, sometimes accompanying fever and systemic symptoms. In such cases, the presence of rare hematological disorders, abnormalities in eosinophils and/or association with Epstein-Barr virus (EBV) may underlie. Importantly, hypersensitivity to mosquito bites (HMB), which is characterized by necrotic skin reactions to mosquito bites with various systemic symptoms, is often observed in association with EBV infection and natural killer (NK) cell lymphoproliferative disorder. Exaggerated skin reaction to mosquito bites is also seen in Wells' syndrome. While strong Th2-skewing immune dysregulation is apparent in the patients, they also show robust CD4(+) T cell proliferation in response to mosquito salivary gland extracts, indicating close association between Wells' syndrome and mosquito bites. Similar skin reaction to mosquito bites is also noticed in certain types of B cell neoplasm, although the role of B cells in this peculiar reaction to mosquito bites is yet to be elucidated. In this review, we will discuss the current knowledge of exaggerated reaction toward mosquito bites seen in conjunction with these unique hematological disorders, and examine the scientific studies and observations reported in previous literatures to organize our current understanding of the pathogenesis of this distinct disorder.

Monoclonal antibodies: the new magic bullets for allergy: IUPHAR Review 17

Allergic diseases and conditions are widespread and their incidence is on the increase. They are characterized by the activation of mast cells resident in tissues and the consequent infiltration and stimulation of several inflammatory cells, predominantly eosinophils. Cell-cell cross-talk and the release of mediators are responsible for the symptoms and for the modulation of the response. The gold standard of therapeutic intervention is still glucocorticosteroids, although they are not effective in all patients and may cause numerous side effects. Symptomatic medications are also widespread. As research has led to deeper insights into the mechanisms governing the diseases, new avenues have been opened resulting in recent years in the development of monoclonal antibodies (mAbs) such as anti-IgE mAbs (omalizumab) and others still undergoing clinical trials aimed to specifically target molecules involved in the migration and stimulation of inflammatory cells. In this review, we summarize new developments in the field of anti-allergic mAbs with special emphasis on the treatment of asthma, particularly severe forms of this condition, and atopic dermatitis, which are two unmet clinical needs.

What is the discrepancy between drug permeation into/across intact and diseased skins? Atopic dermatitis as a model

The discrepancy in drug absorption between healthy and diseased skins is an issue that needs to be elucidated. The present study attempted to explore the percutaneous absorption of drugs via lesional skin by using atopic dermatitis (AD) as a model. Tape-stripping and ovalbumin (OVA) sensitization induced AD-like skin. The lesions were evaluated by physiological parameters, histology, cytokines, and differentiation proteins. The permeants of tacrolimus, 8-methoxypsoralen, methotrexate, and dextran were used to examine in vitro and in vivo cutaneous permeation. Transepidermal water loss (TEWL) increased from 5.2 to 27.4 g/m(2)/h by OVA treatment. AD-like lesions were characterized by hyperplasia, skin redness, desquamation, and infiltration of inflammatory cells. Repeated OVA challenge produced a T-helper 2 (Th2) hypersensitivity accompanied by downregulation of filaggrin, involucrin, and integrin β. Tacrolimus, the most lipophilic permeant, revealed an increase of cutaneous deposition by 2.7-fold in AD-like skin compared to intact skin. The transdermal flux of methotrexate and dextran, the hydrophilic permeants, across AD-like skin increased about 18 times compared to the control skin. Surprisingly, AD-like skin showed less skin deposition of 8-methoxypsoralen than intact skin. This may be because the deficient lipids in the atopic-affected stratum corneum (SC) diminished drug partitioning into the superficial skin layer. The fluorescence and confocal microscopic images demonstrated a broad and deep passage of small-molecular and macromolecular dyes into AD-like skin. The results obtained from this report were advantageous for showing how the lesional skin influenced percutaneous absorption.

Genomic imprinting in psoriasis and atopic dermatitis: A review

Genomic imprinting is a genetic process where only one allele of a particular gene is expressed in a parent-of-origin dependent manner. Epigenetic changes in the DNA, such as methylation or acetylation of histones, are primarily thought to be responsible for silencing of the imprinted allele. Recently, global CpG methylation changes have been identified in psoriatic skin in comparison to normal skin, particularly near genes known to be upregulated in psoriasis such as KYNU, OAS2, and SERPINB3. Furthermore, imprinting has been associated with multi-chromosomal human disease, including diabetes and multiple sclerosis. This paper is the first to review the clinical and genetic evidence that exists in the literature for the association between imprinting and general skin disorders, including atopic dermatitis and psoriatic disease. Atopy was found to have evidence of imprinting on chromosomes 6, 11, 14, and 13. The β subunit of the IgE receptor on chromosome 11q12-13 may be imprinted. Psoriatic disease may be related to imprinting effects on chromosome 6 for psoriasis and 16 for psoriatic arthritis.

Medicinal plants with anti-inflammatory activities

Medicinal plants have been the main remedy to treat various ailments for a long time and nowadays, many drugs have been developed from traditional medicine. This paper reviews some medicinal plants and their main constituents which possess anti-inflammatory activities useful for curing joint inflammation, inflammatory skin disorders, cardiovascular inflammation and other inflammatory diseases. Here, we provide a brief overview of quick and easy reading on the role of medicinal plants and their main constituents in these inflammatory diseases. We hope that this overview will shed some light on the function of these natural anti-inflammatory compounds and attract the interest of investigators aiming at the design of novel therapeutic approaches for the treatment of various inflammatory conditions.