Epidermal barrier and oxidative stress parameters improve during in 311 nm narrow band UVB phototherapy of plaque type psoriasis

The impact of photodynamic therapy on skin homeostasis in patients with actinic keratosis: A prospective observational study

BACKGROUND

Photodynamic therapy (PDT) is an effective treatment for actinic keratosis (AKs), but there is little information on how PDT affects skin barrier function. The objectives of this study are: To compare skin barrier function between skin with AKs and healthy skin and to evaluate the impact of PDT on skin homeostasis in patients with AKs.

METHODS

A prospective observational study was conducted in patients with AKs to evaluate epidermal barrier function and skin homeostasis before and 1 ek after receiving PDT.

RESULTS

A total of 21 subjects were included in the study, male/female ratio was 17:4, mean age was 75.86 years. The number of AKS observed before starting treatment was reduced with respect to those diagnosed 1 month after starting PDT (14.83 vs. 1.91, p < 0.0001). Application of PDT for treating AKs modifies epidermal barrier function. Immediately after the first session temperature, transepidermal water loss (TEWL), stratum corneum hydration (SCH) and total antioxidant capacity (TAC) increased while pH decreased on lesional skin. After 1-month follow-up, the only remained change was the increased in SCH. Higher increases in temperature were observed when using occlusive PDT compared to mixed modality. 5-ALA and M-ALA seem to have a similar impact on skin barrier.

CONCLUSIONS

PDT can improve skin barrier function in patients with AKs. Skin homeostasis parameters can be used to assess efficacy and optimize dosing.

Altered structure indicating reduced barrier function of lesional compared to non-lesional psoriatic skin-A non-invasive in vivo study of the human stratum corneum with confocal Raman micro-spectroscopy

Psoriasis, one of the most common skin diseases affecting roughly 2%-3% of the world population, is associated with a reduced skin barrier function (SBF) that might play an important role in its pathophysiology. The SBF is provided primarily by the stratum corneum (SC) of the skin. Previous studies have revealed a higher trans-epidermal water loss, lower hydration, abnormal concentration and composition of intercellular lipids, as well as alterations in secondary keratin structure in the psoriatic SC. We compared on molecular level lesional psoriatic skin (LPS) with non-lesional psoriatic skin (nLPS) from 19 patients non-invasively in vivo, using confocal Raman micro-spectroscopy. By analysing the corresponding Raman spectra, we determined SBF-defining parameters of the SC depth-dependently. Our results revealed a lower total lipid concentration, a shift of lamellar lipid organisation towards more gauche-conformers and an increase of the less dense hexagonal lateral packing of the intercellular lipids in LPS. Furthermore, we observed lower natural moisturising factor concentration, lower total water as well as a strong tendency towards less strongly bound and more weakly bound water molecules in LPS. Finally, we detected a less stable secondary keratin structure with increased β-sheets, in contrast to the tertiary structure, showing a higher degree of folded keratin in LPS. These findings clearly suggest structural differences indicating a reduced SBF in LPS, and are discussed in juxtaposition to preceding outcomes for psoriatic and healthy skin. Understanding the alterations of the psoriatic SC provides insights into the exact pathophysiology of psoriasis and paves the way for optimal future treatments.

A double-edged sword: ROS related therapies in the treatment of psoriasis

In the onset and progression of psoriasis, redox imbalance is a vital factor. It's widely accepted that too much reactive oxygen species (ROS) always make psoriasis worse. Recent research, however, has shown that the accumulation of ROS is not entirely detrimental, as it helps reduce psoriasis lesions by inhibiting epidermal proliferation and keratinocyte death. As a result, ROS appears to have two opposing effects on the treatment of psoriasis. In this review, the current ROS-related therapies for psoriasis, including basic and clinical research, are presented. Additionally, the design and therapeutic benefits of various drug delivery systems and therapeutic approaches are examined, and a potential balance between anti-oxidative stress and ROS accumulation is also trying to be investigated.

The Gut Microbiome in Psoriasis and Crohn’s Disease: Is Its Perturbation a Common Denominator for Their Pathogenesis?

Psoriasis and inflammatory bowel disease (IBD), including ulcerative colitis (UC) and Crohn’s disease (CD), are interlinked. In fact, the prevalence of IBD is higher in patients with psoriasis, with a risk of ulcerative colitis of 1.6-times higher than in the general population. Analogously, patients with psoriasis have a greater risk of developing IBD. Furthermore, they share some clinical features and pathogenic mechanisms. Both are chronic inflammatory diseases with a relapsing-remitting condition that persists for the patient’s whole life and exhibit increased permeability of the mucosal barrier of skin and gut, allowing an increased interaction of pathogens with inflammatory receptors of the immune cells. A key element in the pathogenesis of these diseases is represented by the microbiota; in particular, the gut microbiota is an important driver of CD pathogenesis, while in psoriasis changes in gut and skin microbiota have been described without a defined pathogenic function. Furthermore, genetic predispositions or environmental factors contribute to disease manifestation, with a central role attributed to the immune responses and, in particular, to a dysregulated role played by T helper 17 cells both in psoriasis and IBD. The purpose of this review was to summarize present information about the links between psoriasis, inflammatory bowel disease, in particular Crohn’s disease, and changes in gut and/or skin microbiome.

The Involvement of Oxidative Stress in Psoriasis: A Systematic Review

Psoriasis is a chronic, immune-mediated inflammatory dermatosis characterized by the appearance of erythematous plaques, covered by white scales, occasionally pruritogenic, and distributed mainly on the extensor areas. Oxidative stress is defined as an imbalance or a transient or chronic increase in the levels of free oxygen/nitrogen radicals, either as a result of the exaggerated elevation in their production or the decrease in their ability to be eliminated by antioxidant systems. Although the pathogenesis of psoriasis remains far from elucidated, there are studies that delineate an involvement of oxidative stress in this skin disorder. Thus, a systematic search was computed in PubMed/Medline, Web of Science and SCOPUS and, in total, 1293 potentially eligible articles exploring this research question were detected. Following the removal of duplicates and the exclusion of irrelevant manuscripts based on the screening of their titles and abstracts (n = 995), 298 original articles were selected for full-text review. Finally, after we applied the exclusion and inclusion criteria, 79 original articles were included in this systematic review. Overall, the data analyzed in this systematic review point out that oxidative stress markers are elevated in psoriasis and share an association with the duration and severity of the disease. The concentrations of these biomarkers are impacted on by anti-psoriasis therapy. In addition, the crosstalk between psoriasis and oxidative stress is influenced by several polymorphisms that arise in genes encoding markers or enzymes related to the redox balance. Although the involvement of oxidative stress in psoriasis remains undisputable, future research is needed to explore the utility of assessing circulating serum, plasma, urinary and/or skin biomarkers of oxidative stress and of studying polymorphisms in genes regulating the redox balance, as well as how can these findings be translated into the management of psoriasis, as well in understanding its pathogenesis and evolution.

Assessment of hand hygiene strategies on skin barrier function during COVID-19 pandemic: a randomized clinical trial

INTRODUCTION

COVID-19 has increased the frequency of hand washing. There is scarce evidence regarding the impact of different hand hygiene procedures on skin barrier function in clinical practice.

OBJECTIVE

To compare the impact on skin barrier function of different hand hygiene measures in health care workers in daily practice.

METHODS

A randomized controlled clinical trial was conducted. Participants were randomized to sanitize their hands with water and soap, alcohol-based hand sanitizers (ABHS) or disinfectant wipes during their 8-hour work-shift. Epidermal barrier functional parameters, like transepidermal water loss (TEWL), and the microbial load were assessed before and immediately after the workday. Tolerance and acceptability of each product were recorded after work.

RESULTS

Sixty-two participants were included and 20, 21 and 21 were randomized respectively to use water and soap, ABHS and disinfectant wipes. After the 8-hour shift, TEWL increase was higher with disinfectant wipes than with soaps or ABHS (+5.45vs + 3.87vs-1.46 g·h^-1 ·m^-2 respectively, P = .023). Bacteria and fungi colony-forming unit (CFU) count reduction was lower for water and soap group than for ABHS and disinfectant wipes. Disinfectant wipes were considered more difficult to use (P = .013) compared to water and soap and ABHS.

CONCLUSION

Daily hand hygiene with ABHS showed the lowest rates of skin barrier disruption and the highest reduction of CFU. This article is protected by copyright. All rights reserved.

Erythema Increase Predicts Psoriasis Improvement after Phototherapy

Psoriasis is a major global health problem. There is a need to develop techniques to help physicians select the most appropriate cost-effective therapy for each patient. The main objectives of this study are (1) to evaluate changes in epidermal barrier function and skin homeostasis after phototherapy and (2) to explore potentially predictive values in epidermal barrier function and skin homeostasis to assess clinical improvement after fifteen sessions of phototherapy. A total of 76 subjects, 38 patients with plaque-type psoriasis and 38 gender- and age-matched healthy volunteers, were included in the study. Erythema, transepidermal water loss (TEWL), temperature, stratum corneum hydration (SCH), pH, sebum, and antioxidant capacity were measured before and after the first and fifteenth phototherapy session. Erythema (401.09 vs. 291.12 vs. 284.52 AU, p < 0.001) and TEWL (18.23 vs. 11.44 vs. 11.41 g·m^-2·h^-1, p < 0.001) were significantly higher at psoriatic plaques than in uninvolved psoriatic skin and healthy volunteers, respectively, while SCH was lower (9.71 vs. 44.64 vs. 40.00 AU, p < 0.001). After fifteen phototherapy sessions, TEWL (-5.19 g·m^-2·h^-1, p = 0.016) decreased while SCH (+7.01 AU, p = 0.013) and erythema (+30.82 AU, p = 0.083) increased at psoriatic plaques. An erythema increase exceeding 53.23 AU after the first phototherapy session, with a sensitivity of 71.4% and specificity of 84.2%, indicates that a patient may improve Psoriasis Area and Severity Index (PASI) by ≥3 points after fifteen phototherapy sessions. In conclusion, phototherapy improves epidermal barrier function in psoriatic patients and the erythema increase after one phototherapy session could help doctors select psoriasis patients who are more likely to respond to phototherapy.

Therapies with Antioxidant Potential in Psoriasis, Vitiligo, and Lichen Planus

Oxidative stress plays an important pathogenetic role in many chronic inflammatory diseases, including those of dermatological interest. In particular, regarding psoriasis, vitiligo, and lichen planus, excess reactive oxygen species and a decline in endogenous antioxidant systems are observed. In this regard, treatments with antioxidant properties could be appropriate therapeutic options. To date, clinical trials in dermatology on these treatments are limited. We reviewed the available studies on the efficacy of antioxidant therapies in psoriasis, vitiligo, and lichen planus. The role of herbal derivatives, vitamins, and trace elements was analyzed. The antioxidant properties of conventional therapies were also evaluated. Data from the literature suggest that antioxidants might be useful, but available studies on this topic are limited, heterogeneous, not completely standardized, and on small populations. Furthermore, in most cases, antioxidants alone are unable to induce significant clinical changes, except perhaps in mild forms, and must be used in conjunction with standard drug treatments to achieve measurable results. Further studies need to be conducted, considering larger populations and using internationally validated scales, in order to compare the results and clinical efficacy.

Combination of retinoids and narrow-band ultraviolet B inhibits matrix metalloproteinase 13 expression in HaCaT keratinocytes and a mouse model of psoriasis

Matrix metalloproteinase13 (MMP13) can be released by keratinocytes and fibroblasts and involved in the pathogenesis of skin disorders. Retinoic acid derivative drugs include tazarotene and acitretin. Tazarotene/acitretin and narrow-band ultraviolet B (NB-UVB) irradiation are common treatment options for psoriasis. However, their impact on MMP13 expression in the context of psoriasis has yet to be determined. The expression of MMP13 was analyzed in patients with psoriasis. The effects of tazarotene/acitretin and NB-UVB on MMP13 expression were also investigated in a mouse model of psoriasis. Human HaCaT keratinocytes were exposed to acitretin or NB-UVB and then assayed for cell proliferation and MMP13 expression levels. We showed that patients with psoriasis had increased levels of MMP13 protein in skin lesions and serum samples. Exposure to acitretin and NB-UVB irradiation alone or in combination led to reduction of cell proliferation and MMP13 expression in HaCaT cells. Consistently, tazarotene treatment or NB-UVB irradiation attenuated imiquimod-induced psoriasis-like dermatitis and decreased MMP13 expression in a mouse model. Based on these from HaCaT keratinocytes cells and animal experiments, we suggest that tazarotene/acitretin and NB-UVB irradiation can inhibit the expression of MMP13 in HaCaT keratinocytes and psoriasis mouse models. Blockade of MMP13 activity may have therapeutic potential in improving symptoms of psoriasis.

Integrated metabolomic analysis and cytokine profiling define clusters of immuno-metabolic correlation in new-onset psoriasis

The association between the metabolic profile and inflammatory cytokines in psoriasis is poorly understood. We analyzed the metabolic and cytokine/chemokine profiles in serum and skin from patients with new-onset psoriasis and healthy subjects (n = 7/group) by HR-MAS NMR and Bio-Plex immunoassay. Immuno-metabolic correlation matrix was analyzed in skin and serum to identify a potential immune-metabolic signature. Metabolomics analysis showed a significant increase in ascorbate and a decrease in scyllo-inositol, and a trend towards an increase in eight other metabolites in psoriatic skin. In serum, there was a significant increase of dimethylglycine and isoleucine. In parallel, psoriatic skin exhibited an increase of early inflammatory cytokines (IL-6, IL-8, TNF-α, IL-1β) and correlation analysis highlighted some major clusters of immune-metabolic correlations. A cluster comprising scyllo-inositol and lysine showed correlations with T-cell cytokines; a cluster comprising serine and taurine showed a negative correlation with early inflammatory cytokines (IL-6, G-CSF, CCL3). A strong positive correlation was enlightened between glutathione and inflammatory cytokines/angiogenesis promoters of psoriasis. The integration of metabolic and immune data indicated a molecular signature constituted by IL-6, IL1-ra, DMG, CCL4, Ile, Gly and IL-8, which could discriminate patients and healthy subjects and could represent a candidate tool in the diagnosis of new-onset psoriasis.

Investigation of water bonding status of normal and psoriatic skin in vivo using diffuse reflectance spectroscopy

Psoriasis affects more than 125 million people worldwide, and the diagnosis and treatment efficacy evaluation of the disease mainly rely on clinical assessments that could be subjective. Our previous study showed that the skin erythema level could be quantified using diffuse reflectance spectroscopy (DRS), and the hemoglobin concentration of most psoriatic lesion was higher than that of its adjacent uninvolved skin. While the compromised epidermal barrier function has been taken as the major cause of clinical manifestation of skin dryness and inflammation of psoriasis, very few methods can be used to effectively evaluate this function. In this study, we investigate the near infrared spectroscopic features of psoriatic (n = 21) and normal (n = 21) skin that could link to the epidermal barrier function. From the DRS measurements, it was found that the water bonding status and light scattering properties of psoriasis are significantly different from those of uninvolved or normal skin. The connection between these parameters to the epidermal barrier function and morphology will be discussed. Our results suggest that objective evaluation of epidermal barrier function of psoriasis could be achieved using a simple DRS system.

Alterations of the Skin and Gut Microbiome in Psoriasis and Psoriatic Arthritis

Numerous scientific studies in recent years have shown significant skin and gut dysbiosis among patients with psoriasis. A significant decrease in microbiome alpha-diversity (abundance of different bacterial taxa measured in one sample) as well as beta-diversity (microbial diversity in different samples) was noted in psoriasis skin. It has been proven that the representation of Cutibacterium, Burkholderia spp., and Lactobacilli is decreased and Corynebacterium kroppenstedii, Corynebacterium simulans, Neisseria spp., and Finegoldia spp. increased in the psoriasis skin in comparison to healthy skin. Alterations in the gut microbiome in psoriasis are similar to those observed in patients with inflammatory bowel disease. In those two diseases, the F. prausnitzii, Bifidobacterium spp., Lactobacillus spp., Parabacteroides and Coprobacillus were underrepresented, while the abundance of Salmonella sp., Campylobacter sp., Helicobacter sp., Escherichia coli, Alcaligenes sp., and Mycobacterium sp. was increased. Several research studies provided evidence for the significant influence of psoriasis treatments on the skin and gut microbiome and a positive influence of orally administered probiotics on the course of this dermatosis. Further research is needed to determine the influence of the microbiome on the development of inflammatory skin diseases. The changes in microbiome under psoriasis treatment can serve as a potential biomarker of positive response to the administered therapy.

The microbiome of the human skin and its variability in psoriasis and atopic dermatitis

The human organism is inhabited by very diverse microorganisms, which constitute the so-called human microbiome and are necessary for the proper functioning of the macroorganism. The correct microbiome ensures homeostasis of the body. A disturbance in its homeostasis leads to dysbiosis. Such deviations may also be related to the development of inflammatory skin diseases, including atopic dermatitis and psoriasis. This review aims to analyse the most current published data on the microbiome of the human skin and examine its role in cutaneous skin diseases, such as atopic dermatitis and psoriasis. This review was compiled by collaborating dermatologists specializing in atopic dermatitis and psoriasis. A comprehensive review of current literature was done using PubMed and limited to relevant case reports and original papers on the skin microbiome in atopic dermatitis and/or psoriasis. It has not been yet established whether changes in the microbiome are the cause or consequence of disease (atopic dermatitis/psoriasis). However, it was found that in the cases where pathological microflora predominated, an intensification of lesion severity is observed, while with clinical improvement, commensal microflora is restored. Modification of the composition of the microflora may lead to changes in the activation of the immune system and eventually to the development of inflammatory diseases. Adverse effects on the microbiome may include antibiotics, poor diet, stress and adverse environmental conditions. However, more research is needed to identify exact details and mechanisms.

Ablation of CRBN induces loss of type I collagen and SCH in mouse skin by fibroblast senescence via the p38 MAPK pathway

Cereblon (CRBN) is a substrate receptor of the cullin-RING E3 ubiquitin ligase (CRL) complex that mediates the ubiquitination of several substrates. In this study, CRBN knockout (KO) mice exhibited decreased levels of stratum corneum hydration (SCH) and collagen I expression with an elevated protein level of matrix metalloprotease 1 (MMP1). The absence of cereblon in the skin of CRBN KO mice mimics the damage caused by narrowband ultraviolet B (NB-UVB). The primary CRBN deficient mouse embryonic fibroblasts (MEFs) undergo G2/M-arrested premature senescence via protein signaling of p38 MAPK and its dependent p53/p21pathway. The absence of CRBN induced the markers of cellular senescence, such as the senescence-associated heterochromatin foci (SAHF), SA-β-Gal staining, and p21 upregulation while the ectopic expression of CRBN reversed the phenotypes of SA-β-Gal staining and p21 upregulation. Reversion of the decreased protein level of collagen I was demonstrated after the reintroduction of the CRBN gene back into CRBN KO MEFs, validating the promising role of CRBN as a potential regulator for the function of the skin barrier and its cellular homeostasis.

Epidermal carotenoid levels in vivo of patients with plaque psoriasis: Effects of narrow-band UVB phototherapy

BACKGROUND

Psoriasis is a systemic inflammatory disease characterized by hindered antioxidant defense and increased formation of free radicals. There are limited data on the skin carotenoids in psoriatic skin as well as their modulation during narrow-band UVB (NB-UVB) phototherapy of the disease.

AIM

The aim of this prospective study is to reveal the skin carotenoids levels during NB-UVB phototherapy of psoriasis in humans.

MATERIAL AND METHODS

Twenty Caucasian subjects with mild-to-moderate plaque psoriasis (15m; 5f) were enrolled in the study, and nine gender- and age-matched healthy volunteers were recruited for controls of oxidative stress measurements. All psoriasis patients underwent 10 sessions of NB-UVB phototherapy. Measurements were taken at baseline and after 10 sessions of NB-UVB phototherapy. The assessment of carotenoid levels in the skin in vivo was performed by a non-invasive, reflectance spectroscopy-based device. Psoriasis severity was assessed by psoriasis area and severity index (PASI). The dermatology life quality index (DLQI) was evaluated in psoriatic patients.

RESULTS

Baseline carotenoid levels were significantly lower in psoriasis patients in comparison to healthy controls. NB-UVB phototherapy insignificantly diminished carotenoid levels in the skin of psoriasis patients, while clinical improvement both in PASI score and DLQI was observed.

CONCLUSION

We showed the levels of skin carotenoids in psoriatic patients are lower than in healthy subjects. NB-UVB did not change significantly skin carotenoid levels. Further studies should elucidate the potential effect of antioxidants supplementation during NB-UVB of psoriasis.

Epidermal barrier changes in patients with psoriasis: The role of phototherapy

BACKGROUND

Some skin diseases may modify epidermal barrier function. Psoriasis is a chronic multi-systemic inflammatory disease that affects the epidermal barrier. Phototherapy is an option for treating psoriasis, but little is known about how epidermal barrier function is modified by phototherapy in psoriatic patients.

OBJECTIVES

(a) To compare skin homeostasis between involved and uninvolved skin in psoriatic patients with healthy controls (b) To evaluate changes in the epidermal barrier function in psoriatic patients treated with phototherapy.

METHODS

Sixty patients with plaque-type psoriasis and sixty gender and age-matched healthy controls were enrolled. Temperature, transepidermal water loss (TEWL), stratum corneum hydration (SCH), pH, elasticity, erythema and melanin index were measured using non-invasive tools in the healthy control and involved and uninvolved psoriatic skin before and after phototherapy.

RESULTS

Healthy controls had lower TEWL and erythema index and higher SCH than psoriatic patients, both at uninvolved psoriatic skin and psoriasis plaques. TEWL was higher at psoriasis plaques than at uninvolved skin (19.20 vs 11.57 g/h/m² ; P < .001). Following phototherapy, a decreasing trend was observed for TEWL, of 1.03 (SD 0.75) and 0.97 (SD 0.81) g/h/m² for uninvolved and involved skin respectively. SCH was significantly lower at psoriatic plaques than at uninvolved skin (7.32 vs 36.62Arbitrary Units [AU]; P < .001). SCH increased by 1.15AU (SD 0.26) on psoriatic plaques after the phototherapy session (P < .001).

CONCLUSION

Psoriatic plaques showed epidermal barrier dysfunction compared to uninvolved skin and healthy controls. Phototherapy may improve epidermal barrier function in psoriatic patients. SCH increased after a phototherapy session on the psoriatic plaques.

A Spectrum of Skin Disease: How Staphylococcus aureus Colonization, Barrier Dysfunction, and Cytokines Shape the Skin

Cytokines are key mediators of skin homeostasis and disease through their effects on keratinocytes, skin barrier integrity, immune activation, and microbial ecology. Sirobhushanam et al. (2020) suggest that the IFN signature in lupus erythematosus (LE) alters expression of epithelial barrier and adhesin genes, which, in turn, promotes Staphylococcus aureus colonization. This work highlights the need to better understand both barrier function and S. aureus colonization in LE, two new potential therapeutic targets for the treatment of LE.

Altered Epidermal Permeability Barrier Function in the Uninvolved Skin Supports a Role of Epidermal Dysfunction in the Pathogenesis of Occupational Hand Eczema

Although a compromised epidermal permeability barrier can contribute to the development of contact dermatitis, whether subjects with hand eczema display abnormalities in baseline epidermal permeability barrier function in their uninvolved skin remains unknown. The aim of the present study was to assess epidermal permeability barrier function in subjects with and without hand eczema in clothing manufacturers. Upon approval by the institutional review board, volunteers were recruited from clothing manufacturers in Guangzhou City, China. An 11-item questionnaire was used to collect general data from the volunteers. The diagnoses of self-proclaimed hand eczema were further confirmed by a dermatologist. Epidermal biophysical properties, including transepidermal water loss (TEWL) rates, stratum corneum hydration and skin surface pH were measured on the flexural surface of the left forearm in all volunteers. Epidermal biophysical properties were compared among cohorts of subjects with active hand eczema, a prior history of hand eczema and without any history of hand eczema. A total of 650 questionnaires were collected from 462 females and 188 males, with a mean age of 36.7 ± 0.46 years (range 16-69 years; 95% CI 35.8-37.59). Thirty-five subjects (5.4%) currently had hand eczema, while 28 subjects (4.3%) reported a prior history of hand eczema that was inactive currently. The prevalence of hand eczema did not differ significantly between genders. Neither a prior personal nor a family history of allergies was associated with the prevalence of hand eczema, but certain occupations and frequent contact with disinfectants were independently associated with the prevalence of hand eczema. In the overall cohort, males displayed higher TEWL rates and stratum corneum hydration levels than did females. Both skin surface pH and TEWL rates differed significantly among normal controls and subjects with active hand eczema or a prior history of hand eczema (p < 0.05). In conclusion, the uninvolved skin site of subjects with hand eczema exhibits abnormalities in epidermal perme-ability barrier, supporting a pathogenic role of epidermal dysfunction in hand eczema. Whether subjects with hand eczema in other occupations also display altered epidermal function on uninvolved skin remains to be explored.

Convallatoxin induces HaCaT cell necroptosis and ameliorates skin lesions in psoriasis-like mouse models

Psoriasis is considered an immune-mediated inflammatory skin disorder that affects the quality of life of nearly four percent of the world population. Considering the side effects of existing therapeutic drugs and the urgent need for new drug development, we screened more than 250 traditional Chinese medicine compounds to identify drugs that significantly reduced the viability of human HaCaT keratinocytes, a psoriasis-related model cell line. Convallatoxin (CNT) was found to be a highly effective inhibitor of HaCaT cell viability. Subsequent mechanistic studies revealed that CNT induced HaCaT cell death by necroptosis rather than by apoptosis. CNT destroyed the membrane integrity of HaCaT cells, as detected by nuclear propidium iodide (PI) staining and lactate dehydrogenase (LDH) release. Additionally, the intercellular levels of adenosine triphosphate (ATP) were lower in HaCaT cells treated with CNT than in control HaCaT cells, and typical necroptosis-associated characteristics were observed by electron microscopy in cells treated with CNT. Furthermore, compared with control HaCaT cells, CNT-treated HaCaT cells produced more reactive oxygen species (ROS), but this effect was inhibited by the antioxidants N-acetyl-cysteine (NAC), diphenyleneiodonium chloride (DPI), and apocynin and the necroptosis inhibitor Nec-1. In addition, antioxidant treatment attenuated necroptotic cell death, suggesting that CNT-induced HaCaT necroptosis is mediated by oxidative stress. More importantly, CNT ameliorated skin lesions and inflammation in imiquimod (IMQ)- and 12-O-tetradecanoyl-phorbol-13-acetate (TPA)-induced psoriasis-like mouse models. In conclusion, our results demonstrate that CNT is cytotoxic against HaCaT cells in vitro and exerts antipsoriatic activities in two mouse models of psoriasis in vivo, making CNT a potential promising candidate drug for future research.

Non-invasive Approaches for the Diagnosis of Autoimmune/Autoinflammatory Skin Diseases-A Focus on Psoriasis and Lupus erythematosus

The traditional diagnostic gold standard for inflammatory skin lesions of unclear etiology is dermato-histopathology. As this approach requires an invasive skin biopsy, biopsy processing and analysis by specialized histologists, it is a resource intensive approach requiring trained healthcare professionals. In many health care settings access to this diagnostic approach can be difficult and outside emergency cases will usually take several weeks. This scenario leads to delayed or inappropriate treatment given to patients. With dramatically increased sensitivity of a range of analysis systems including mass spectrometry, high sensitivity, multiplex ELISA based systems and PCR approaches we are now able to "measure" samples with unprecedented sensitivity and accuracy. Other important developments include the long-term monitoring of parameters using microneedle approaches and the improvement in imaging systems such as optical coherence tomography. In this review we will focus on recent achievements regarding measurements from non-invasive sampling, in particular from plucked hair and skin tape-strips which seem well suited for the diagnosis of lupus erythematosus and psoriatic inflammation, respectively. While these approaches will not replace clinical observation-they can contribute to improved subgroup diagnosis, stratified therapeutic approaches and have great potential for providing molecular and mechanistic insight in to inflammatory skin diseases.

Erianin Inhibits Proliferation and Induces Apoptosis of HaCaT Cells via ROS-Mediated JNK/c-Jun and AKT/mTOR Signaling Pathways

Psoriasis is a recurrent skin disease described as keratinocyte hyperproliferation and aberrant differentiation. Erianin, a bibenzyl compound extracted from Dendrobium chrysotoxum, has displayed antitumor and anti-angiogenesis effects. However, the effects of erianin on a human keratinocyte cell line (HaCaT) are not fully understood. In the present study, we explored the effect of erianin on proliferation and apoptosis in HaCaT cells. Our results indicated that treatment with erianin ranging from 12.5 nM to 50 nM inhibited proliferation and induced apoptosis of HaCaT cells. In addition, erianin-induced apoptosis was accompanied by elevated reactive oxygen species (ROS). The ROS scavenger N-acetyl-cysteine (NAC) attenuated this elevation. Moreover, treatment with erianin induced activation of the c-Jun N-terminal kinase (JNK)/c-Jun signaling pathway and suppressed the protein kinase B (AKT)/mammalian target of rapamycin (mTOR) signaling pathway, while pretreatment with NAC also reversed these effects. Collectively, these data demonstrated that erianin inhibited proliferation and induced apoptosis of HaCaT cells through ROS-mediated JNK/c-Jun and AKT/mTOR signaling pathways. Erianin could be recognized as a potential anti-psoriasis drug.

Transient receptor potential ankyrin 1 (TRPA1) positively regulates imiquimod-induced, psoriasiform dermal inflammation in mice

Transient receptor potential ankyrin 1 (TRPA1), a membrane protein ion channel, is known to mediate itch and pain in skin. The function of TRPA1, however, in psoriasiform dermatitis (PsD) is uncertain. Herein, we found that expression of TRPA1 is highly up-regulated in human psoriatic lesional skin. To study the role of TRPA1 in PsD, we assessed Psoriasis Severity Index (PSI) scores, transepidermal water loss (TEWL), skin thickness and pathology, and examined dermal inflammatory infiltrates, Th17-related genes and itch-related genes in c57BL/6 as wild-type (WT) and TRPA1 gene knockout (KO) mice following daily application of topical IMQ cream for 5 days. Compared with WT mice, clinical scores, skin thickness change and TEWL scores were similar on day 3, but were significantly decreased on day 5 in IMQ-treated TRPA1 KO mice (vs WT mice), suggesting reduced inflammation and skin barrier defects. Additionally, the relative area of epidermal Munro's microabscesses and mRNA levels of neutrophil inducible chemokines (S100A8, S100A9 and CXCL1) were decreased in the treated skin of TRPA1 KO mice, suggesting that neutrophil recruitment was impaired in the KO mice. Furthermore, mast cells, CD31⁺ blood vascular cells, CD45⁺ leukocytes and CD3⁺ T cells were all reduced in the treated skin of TRPA1 KO mice. Lastly, mRNA expression levels of IL-1β, IL-6, IL-23, IL-17A, IL-17F and IL-22 were decreased in TRPA1 KO mice. In summary, these results suggest a key role for TRPA1 in psoriasiform inflammation and raising its potential as a target for therapeutic intervention.

Early immunologic changes during the onset of atopic dermatitis

OBJECTIVE

Atopic dermatitis (AD), which is commonly called eczema, is the most common chronic inflammatory skin disease. The pipeline of new targeted treatments is currently expanding, a development that is largely based on our increasing understanding of disease mechanisms. Mechanistic insights have long been based on long-standing adult AD. Recently, studies also investigated early pediatric AD at disease onset, and revealed several differences in barrier and immune properties when compared with long-standing adult AD. This review focuses on immunological changes very early in life that predispose to the development of AD, and summarizes characteristics of the molecular AD phenotype in this age group.

DATA SOURCES

Review of published literature.

STUDY SELECTIONS

Studies investigating human AD at disease onset in newborns, toddlers, and young children, in comparison with adults with long-standing disease.

RESULTS

Already in cord blood, increased Th2 and decreased Th1 levels were found to increase the risk of AD development. Both pediatric and adult AD share Th2/Th22 activation and defects in lipid barrier deposition and tight junction formation, but Th1 activation and epidermal differentiation complex defects are largely absent in pediatric AD.

CONCLUSION

Immune changes predisposing to AD development are present very early in life. During the first months of disease, AD shows various differences in immune and barrier properties from long-standing adult AD, which might necessitate tailored treatment approaches depending on the age of the patient.

TRPV1 mediates inflammation and hyperplasia in imiquimod (IMQ)-induced psoriasiform dermatitis (PsD) in mice

BACKGROUND

Transient Receptor Potential Vanilloid 1 (TRPV1) is known to mediate itch and neurogenic inflammation, but the role of TRPV1 in psoriasiform dermal inflammation is poorly understood.

OBJECTIVE

To investigate the function of TRPV1 in imiquimod (IMQ)-induced psoriasiform dermatitis (PsD) in mice.

METHODS

Following daily treatment of topical IMQ cream for consecutive 5 days in C57BL/6 wide-type (WT) and TRPV1 gene knockout (KO) mice, we assessed the psoriasis severity index (PSI) scores, transepidermal water loss (TEWL), dermal inflammatory infiltrates, as well as gene expression levels for psoriasis related genes in mouse skin lesions.

RESULTS

Compared with WT mice, the clinical and TEWL scores, the extent of skin hyperplasia, the area of Munro microabscesses (MM) and angiogenesis of psoriasis were all significantly decreased in TRPV1 KO mice triggered with IMQ, suggesting a reduction in skin inflammation and barrier defects. In addition, the infiltration of CD45⁺ leukocytes, mast cells as well as CD3⁺ T cells was all reduced in the IMQ-treated skin of TRPV1 KO mice. Quantitative Real-time PCR (RT-qPCR) revealed that expression levels of IL-1β, IL-6, IL-23, S100A8 were decreased while IL-10 was increased in TRPV1 KO mice.

CONCLUSIONS

In summary, key markers of psoriatic inflammation and epidermal hyperplasia are reduced in TRPV1 KO mice, indicating the involvement of TRPV1 in the psoriasiform inflammation and suggesting its potential as a therapeutic target.

Psoriasis and Microbiota: A Systematic Review

Background: Recent advances have highlighted the crucial role of microbiota in the pathophysiology of chronic inflammatory diseases as well as its impact on the efficacy of therapeutic agents. Psoriasis is a chronic, multifactorial inflammatory skin disorder, which has a microbiota distinct from healthy, unaffected skin. Aim: Through an extensive review of the literature, we aim to discuss the skin and gut microbiota and redefine their role in the pathogenesis of psoriasis. Conclusions: Unfortunately, the direct link between the skin microbiota and the pathogenesis of psoriasis remains to be clearly established. Apart from improving the course of psoriasis, selective modulation of the microbiota may increase the efficacy of medical treatments as well as attenuate their side effects.