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Basal keratinocytes of human epidermis strongly express the cell surface glycoprotein β1-integrin, and putatively harbour epidermal stem cells. Selective sorting and culturing of keratinocyte stem cells forms the basis for studies on the role of these cells as targets for therapeutic intervention and gene therapy. Here we have studied variables which affect cell surface labelling for β1-integrin, flow sorting and subsequent culturing of β1-integrin-positive and β1-integrin-negative keratinocytes. Keratinocytes were derived from small human skin punch biopsies (3 or 4 mm in diameter), and we tested a number of variables such as choice of proteolytic enzyme for cell isolation, cell concentration, fixation, storage of fixed cell suspensions and labelling conditions. In contrast to thermolysin treatment for cell isolation, trypsin treatment left most cell surface β1-integrin molecules intact. Ethanol and paraformaldehyde fixation interfered with β1-integrin detection, and unfixed cells gave the best results. Optimisation of all the individual steps resulted in a labelling protocol for reproducible staining and sorting of the cells. Sorted cells were seeded in 96-well plates (300 cells/well) and colonies were obtained in more than 50% of the wells with β1-integrin-positive keratinocytes. In plates with β1-integrin-negative cells, only 10% of the wells contained keratinocyte colonies. Flow sorted keratinocytes obtained by trypsin formed numerous colonies in cell culture experiments. In cell suspensions obtained with thermolysin, only sparse colonies were formed. We conclude that our methodology permits the use of small human tissue samples for cell labelling and sorting, while preserving the clonogenic potential. [Copyright &y& Elsevier]

In the present study we compared the effect of a ceramide 3-containing emollient (Locobase® Repair) with a control emollient (vaselinum album/cremor lanette ana) and untreated damaged skin using clinical, bioengineering and immunohistochemical methods in two different models of experimentally induced skin barrier dysfunction. In model A (n = 13) skin barrier dysfunction was inflicted at three investigation sites by tape stripping. In model B (n = 13) the volunteers were patch tested at three investigation sites with sodium dodecyl sulphate (0.2%) for 4 h a day for 4 consecutive days. The investigation sites were treated once a day with the above-mentioned agents. Irritant reaction was assessed daily by erythema scoring and measurements of transepidermal water loss (TEWL). After 5D, punch biopsies were taken from all sites. Immunohistochemical assessment was carried out with respect to epidermal proliferation, epidermal differentiation and Langerhans cells. Tape stripping resulted in an erythematous reaction and an increase of TEWL associated with up-regulation of cycling cells, involucrin and expression of cytokeratin 16. At day 4, ceramide 3-containing emollient significantly decreased (p < 0.03) the erythema score, TEWL and cycling cells in comparison with the untreated site. Repetitive exposure to SDS induced a variable degree of erythema, gradual increase of TEWL, an increase of cycling cells, and up-regulation of involucrin, E-FABP and SKALP. The treatment with the control emollient significantly prevented erythema, increase of TEWL and cycling cells at day 4 compared to the untreated site. In summary, the present study demonstrated that both tested emollients improve skin barrier in different conditions compared to the untreated skin. There is some indication that formulations containing skin-related lipids might be of benefit in barrier disruption following tape stripping. Different models and clinical trials are needed to establish the... [ABSTRACT FROM AUTHOR]

Recently we have reported the purification and biochemical characterization of a new, inducible elastase inhibitor [skin-derived antileukoproteinase (SKALP)], which could be extracted in high amounts from psoriatic skin but not from normal human skin. Here we demonstrate the immunohistochemical localization of SKALP in psoriatic epidermis. SKALP was found exclusively in the upper layers of the suprabasal compartment and stratum corneum of lesional psoriatic epidermis. Basal keratinocytes were always negative. No immunoreactive SKALP was found in normal epidermis and non-lesional psoriatic epidermis, in accordance with findings in functional assays. Western blots of skin extracts from psoriatic and normal skin confirmed the immunohistochemical findings and revealed two major bands with apparent molecular weights of 10.5 and 11.5 kDa. We would hypothesize that SKALP could act as a modulator of epidermal inflammation by interfering with polymorphonuclear leukocyte trafficking, and that it could protect structural proteins against elastase-mediated damage. [ABSTRACT FROM AUTHOR]

The article focuses on the significance of microbiome in psoriasis. Topics discussed include the expansion of microbiome field, the relationship between diseases, the DNA sequencing technologies, microbial gene sequencing, genetic risk factors of psoriasis, and the effect of gut microbiome on human physiology.

Abstract: Large-scale in vivo evaluation of biomaterials is time-consuming and limited by ethical considerations. The availability of a library of biomaterials would allow a fast and rational in vitro selection of those biomaterials to be evaluated in vivo. For this reason, we developed an array of 48 different, molecularly-defined films based on native fibrillar collagen. The films differed in the type and amount of extracellular matrix components (type I/IV collagens, fibrous/solubilised elastin, glycosaminoglycans, heparin, chondroitin sulfate or dermatan sulfate), method of preparation (homogenisation) and method and extent of crosslinking (carbodiimide (EDC/NHS) or glutaraldehyde). The array was evaluated by studying morphology, proliferation and differentiation of primary human keratinocytes/fibroblasts. Major differences were observed. Only a small selection of films (especially those containing elastin fibres) specifically stimulated the proliferation of keratinocytes, but not fibroblasts. Such films may be the biomaterials of choice for in vivo evaluation for skin tissue engineering and regenerative medicine. [Copyright &y& Elsevier]

in order to define the antigenic properties necessary for sustained allergic arthritis, we prepared a range of differently charged bovine serum albumin (BSA) species with increasing isoelectric points (4.5, 4.5-7.4, 7-8, 85-9 and >9). The highly cationic BSA >9 appeared to be in a polymeric form. We investigated three properties of these proteins: (i) antigen retention, (ii) T-cell reactivity, and (iii) arthritis induction. Injection of the respective radiolabelled antigens in the knee-joints of immunized mice showed that antigen retention increased with cationicity of the proteins, with the best retention found for ESA with pI>9. However, sustained joint inflammation was only found with BSA859, and not with a level RSA of lower or even higher pI T-cell reactivity in vivo as measured by delayed-type hypersensitivity (skin testing) was similar for the tested antigens, with the exception of polymeric BSA (>9). The latter appeared to be a poor antigen. In vitro, T-cell reactivity ([³H]- thymidine incorporation) against the cationized BSA species was slightly higher as compared to native BSA. The combination of excellent antigen retention and adequate T-cell reactivity appears to be optimal for the induction of chronic arthritis. [ABSTRACT FROM AUTHOR]

Background The effectiveness of biologics for psoriasis shows heterogeneity among patients. With pharmacogenetic markers, it might be possible to predict treatment response. Objectives We aimed to test the association between genetic markers and the response to biologics in psoriasis (etanercept, adalimumab, ustekinumab) in a prospective cohort. Methods We investigated the copy number variation in the LCE3B and LCE3C genes, and eight single-nucleotide polymorphisms ( SNPs) in HLA-C*06, CD84, IL12B, IL23R, TRAF3 IP2, ERAP1, IFIH1 and TNFAIP3. The decrease in Psoriasis Area and Severity Index ( PASI) was calculated as ∆ PASI (absolute PASI decrease compared with baseline) and PASI 75 (proportion of patients with ≥ 75% improvement vs. baseline). Associations between genetic variants and treatment outcome were assessed using multivariable linear regression analysis (∆ PASI corrected for baseline PASI, primary analysis) and Pearson's χ2-test or Fisher's exact test ( PASI 75, secondary analysis). Results We included 348 treatment episodes in 234 patients. Patients heterozygous ( GA) for the SNP in CD84 (rs6427528) had a better ∆ PASI response to etanercept after 3 months ( P = 0·025) than the homozygous reference group ( GG). In addition, patients heterozygous ( CT) for the IL12B variant showed a better response (∆ PASI) to ustekinumab ( P = 0·017) than the reference group ( CC). Patients homozygous ( GG) for the SNP in TNFAIP3 showed a worse response (∆ PASI) to ustekinumab ( P = 0·031) than the reference group ( TT). The associations with ustekinumab resulting from the primary analysis were not confirmed in the secondary ( PASI 75) analysis. Conclusions We demonstrated a strong association between etanercept use in psoriasis and variations in CD84, a gene that was previously found to be a predictor of response to etanercept in rheumatoid arthritis. [ABSTRACT FROM AUTHOR]

The tenascin-X ( TNX) deficient type Ehlers-Danlos syndrome ( EDS) is similar to the classical type of EDS. Because of the limited awareness among geneticists and the challenge of the molecular analysis of the TNXB gene, the TNX-deficient type EDS is probably to be under diagnosed. We therefore performed an observational, cross-sectional study. History and physical examination were performed. Results of serum TNX measurements were collected and mutation analysis was performed by a combination of next-generation sequencing ( NGS), Sanger sequencing and multiplex ligation-dependent probe amplification ( MLPA). Included were 17 patients of 11 families with autosomal recessive inheritance and childhood onset. All patients had hyperextensible skin without atrophic scarring. Hypermobility of the joints was observed in 16 of 17 patients. Deformities of the hands and feet were observed frequently. TNX serum level was tested and absent in 11 patients (seven families). Genetic testing was performed in all families; 12 different mutations were detected, most of which are suspected to lead to non-sense mRNA mediated decay. In short, patients with the TNX-deficient type EDS typically have generalized joint hypermobility, skin hyperextensibility and easy bruising. In contrast to the classical type, the inheritance pattern is autosomal recessive and atrophic scarring is absent. Molecular analysis of TNXB in a diagnostic setting is challenging. [ABSTRACT FROM AUTHOR]

A letter to the editor on a research study on Autoinflammatory Disorders (AID) characterized by an unprovoked innate immune response, resulting in recurrent or ongoing systemic inflammation and fever, is presented.

Background Deletion of the late cornified envelope ( LCE) proteins LCE3B and LCE3C is a strong and widely replicated psoriasis risk factor. It is amenable to biological analysis because it precludes the expression of two epidermis-specific proteins, rather than being a single-nucleotide polymorphism of uncertain significance. The biology of the 18-member LCE family of highly homologous proteins has remained largely unexplored so far. Objectives To analyse LCE3 expression at the protein level in human epithelia, as a starting point for functional analyses of these proteins in health and disease. Methods We generated the first pan- LCE3 monoclonal antibody and provide a detailed analysis of its specificity towards individual LCE members. LCE2 and LCE3 expression in human tissues and in reconstructed human skin models was studied using immunohistochemical analyses and quantitative polymerase chain reaction. Results Our study reveals that LCE2 and LCE3 proteins are differentially expressed in human epidermis, and colocalize only in the upper stratum granulosum layer. Using an in vitro reconstructed human skin model that mimics epidermal morphogenesis, we found that LCE3 proteins are expressed at an early time point during epidermal differentiation in the suprabasal layers, while LCE2 proteins are found only in the uppermost granular layer and stratum corneum. Conclusions Based on the localization of LCE2 and LCE3 in human epidermis we conclude that members of the LCE protein family are likely to have distinct functions in epidermal biology. This finding may contribute to understanding why LCE3B/C deletion increases psoriasis risk. [ABSTRACT FROM AUTHOR]

Background Schnitzler's syndrome (SchS) is an autoinflammatory disease characterized by a chronic urticarial rash, a monoclonal component and signs of systemic inflammation. Interleukin ( IL)-1β is pivotal in the pathophysiology. Objectives Here we investigated the cellular source of proinflammatory mediators in the skin of patients with SchS. Methods Skin biopsies of lesional and nonlesional skin from eight patients with SchS and healthy controls, and patients with cryopyrin-associated periodic syndrome ( CAPS), delayed-pressure urticaria ( DPU) and cold-contact urticaria ( CCU) were studied. We studied in vivo IL-1β, IL-17 and antimicrobial protein ( AMP) expression in resident skin cells and infiltrating cells. In addition we investigated the in vitro effect of IL-1β, IL-17 and polyinosinic-polycytidylic acid (poly: IC) stimulation on cultured epidermal keratinocytes. Results Remarkably, we found IL-1β-positive dermal mast cells in both lesional and nonlesional skin of patients with SchS, but not in healthy control skin and CCU, and fewer in CAPS. IL-17-positive neutrophils were observed only in lesional SchS and DPU skin. In lesional SchS epidermis, mRNA and protein expression levels of AMPs were strongly increased compared with nonlesional skin and that of healthy controls. When exposed to IL-1β, poly: IC or IL-17, patient and control primary human keratinocytes produced AMPs in similar amounts. Conclusions Dermal mast cells of patients with SchS produce IL-1β. This presumably leads to activation of keratinocytes and neutrophil influx, and further amplification of inflammation by IL-17 (from neutrophils and mast cells) and epidermal AMP production leading to chronic histamine-independent neutrophilic urticarial dermatosis. [ABSTRACT FROM AUTHOR]

Background Psychosocial stress can be a risk factor for the maintenance and exacerbation of chronic inflammatory diseases, such as psoriasis and rheumatoid arthritis ( RA). Objectives To gain insight into the specificity of the psychophysiological stress response during chronic inflammation, we assessed autonomic and neuroendocrine responses to stress in different chronic inflammatory diseases. Methods Thirty patients with psoriasis (nine women, mean age 58·5 years ± 12·4), 34 patients with RA (16 women, mean age 60·8 years ± 9·2) and 25 healthy controls (16 women, mean age 55·6 years ± 8·7) underwent a standardized psychosocial stress task ( Trier Social Stress Test). Salivary levels of α-amylase and cortisol and self-reported tension levels were measured before and after the stress test. Results The cortisol response to stress was heightened in patients with psoriasis compared with patients with RA and healthy controls, whereas there were no differences in the autonomic and self-reported measures. Conclusions The altered neuroendocrine stress response in patients with psoriasis suggests that stressful events might have different physiological consequences for specific patient groups with chronic inflammatory conditions, possibly adversely affecting disease status. [ABSTRACT FROM AUTHOR]

Background The use of recently introduced biologics targeting specific immune mechanisms has identified crucial steps in the pathogenesis of psoriasis. Studying the dynamics of changes of these target mechanisms in sequential skin biopsies during treatment with biologics may reveal potential biomarkers. Correlation between clinical parameters and the expression of specific genes during treatments may identify markers indicative of treatment response. Objectives This observational open-label study aimed to provide an overview of important cell biological changes in lesional skin during treatment with adalimumab, and their relationship to clinical improvement. Methods Ten patients with moderate-to-severe plaque psoriasis were included and treated with adalimumab for 16 weeks. At baseline, and after 10 days and 16 weeks of treatment clinical scores were assessed and biopsies were taken to examine gene expression at the mRNA and protein level. Results The expression of marker genes for innate immunity, and epidermal differentiation and proliferation was rapidly restored to normal levels, whereas genes of the adaptive immune system showed a delayed decrease. The static and dynamic course of CD1a+ Langerhans cells and Ki67+ nuclei showed a significant strong correlation to the Psoriasis Area and Severity Index score. No correlation between interleukin-17 expression and clinical scores was found. Conclusions The innate immune system is affected during adalimumab treatment well before the changes in the adaptive immune system become apparent. We may speculate that the addition of a treatment with an early effect on adaptive immunity to adalimumab may result in superior effectiveness compared with monotherapies. [ABSTRACT FROM AUTHOR]

Diseases of the skin are amenable to RNAi-based therapies and targeting key components in the pathophysiology of psoriasis using RNAi may represent a successful new therapeutic strategy. We aimed to develop a straightforward and highly reproducible in vitro psoriasis model useful to study the effects of gene knockdown by RNAi and to identify new targets for topical RNAi therapeutics. We evaluated the use of keratinocytes derived from psoriatic plaques and normal human keratinocytes (NHKs). To induce a psoriatic phenotype in NHKs, combinations of pro-inflammatory cytokines (IL-1α, IL-17A, IL-6 and TNF-α) were tested. The model based on NHK met our needs of a reliable and predictive preclinical model, and this model was further selected for gene expression analyses, comprising a panel of 55 psoriasis-associated genes and five micro-RNAs (miRNAs). Gene silencing studies were conducted by using small interfering RNAs (siRNAs) and miRNA inhibitors directed against potential target genes such as CAMP and DEFB4 and miRNAs such as miR-203. We describe a robust and highly reproducible in vitro psoriasis model that recapitulates expression of a large panel of genes and miRNAs relevant to the pathogenesis of psoriasis. Furthermore, we show that our model is a powerful first step model system for testing and screening RNAi-based therapeutics. [ABSTRACT FROM AUTHOR]

Background Recent studies have emphasized the importance of heritable and acquired skin barrier abnormalities in common inflammatory diseases such as psoriasis and atopic dermatitis (AD). To date, no comprehensive studies on the effect of experimental barrier disruption on cornified envelope protein expression have been performed. Objectives To analyse the effect of experimental skin barrier disruption on the expression of cornified envelope structural proteins and keratinocyte differentiation-regulating proteins. Methods We examined mRNA (day 1, 3 and 7) and protein (day 1, 2, 4 and 9) expression levels of structural proteins and regulatory molecules after sodium dodecyl sulphate (SDS) application on normal skin, and tape stripping of uninvolved epidermis of patients with psoriasis and AD and healthy controls. Results Upon tape stripping, several structural molecules were significantly downregulated (at the mRNA level as well as the protein level), including LCE5A, LCE2B, FLG, FLG2 and LOR, whereas others were upregulated: IVL, SPRR1, SPRR2, HRNR and most notably LCE3A. The epidermal crosslinking enzymes TGM1, TGM3 and TGM5 were all upregulated, whereas proteases involved in the desquamation process (CTSV, KLK5 and KLK7) were downregulated or unaffected. Most results were similar in SDS-instigated irritant contact dermatitis. There was no significant difference in response between normal epidermis and nonlesional skin of patients with psoriasis and AD. Conclusions Skin barrier disruption induces a temporary barrier repair response composed of increased expression of several cornification-related proteins, and decreased expression of some structural and desquamation-related proteins. [ABSTRACT FROM AUTHOR]

Introduction: Tenascin-X (TNX) is an extracellular matrix (ECM) glycoprotein, the absence of which in humans leads to a recessive form of Ehlers-Danlos syndrome (EDS), a group of inherited connective tissue disorders characterized by joint hypermobility, skin hyperextensibility, and tissue fragility. A mouse model of TNX-deficient type EDS has been used to characterize the dermatological, orthopedic, and obstetrical features. The growing insight in the clinical overlap between myopathies and inherited connective tissue disorders asks for a study of the muscular characteristics of inherited connective tissue diseases. Therefore, this study aims to define the muscular phenotype of TNX knockout (KO) mice. Materials and methods: We performed a comprehensive study on the muscular phenotype of these TNX KO mice, consisting of standardized clinical assessment, muscle histology, and gene expression profiling of muscle tissue. Furthermore, peripheral nerve composition was studied by histology and electron microscopy. Results: The main findings are the presence of mild muscle weakness, mild myopathic features on histology, and functional upregulation of genes encoding proteins involved in ECM degradation and synthesis. Additionally, sciatic nerve samples showed mildly reduced collagen fibril density of endoneurium. Discussion: The muscular phenotype of TNX KO mice consists of mild muscle weakness with histological signs of myopathy and of increased turnover of the ECM in muscle. Furthermore, mildly reduced diameter of myelinated fibers and reduction of collagen fibril density of endoneurium may correspond with polyneuropathy in TNX-deficient EDS patients. This comprehensive assessment can serve as a starting point for further investigations on neuromuscular function in TNX KO mice. [ABSTRACT FROM AUTHOR]

Tenascin-X is a large extracellular matrix glycoprotein that is widely distributed within connective tissues and is associated with an autosomal recessive type of Ehlers-Danlos syndrome (EDS). Tenascin-X represents the first EDS susceptibility gene that does not code for a fibrillar collagen or collagen-processing enzyme. We describe a paediatric case of tenascin-X deficiency and review the literature. [ABSTRACT FROM AUTHOR]

Psychological stressors might contribute to the severity of chronic inflammatory diseases such as psoriasis by dysregulating hypothalamic-pituitary-adrenal (HPA) axis activity. To evaluate the role of cortisol, a key component of the HPA axis, in reaction to psychological stress in patients with psoriasis. Serum cortisol, clinical indicators of disease severity (Psoriasis Area and Severity Index) and self-report measures of daily stressors were measured monthly for 6 months in 62 patients with psoriasis. In addition to the previous findings in this sample showing that peak levels of daily stressors predicted an increase in disease severity a month later, the peak levels of daily stressors were also significantly associated with a lower cortisol level. Moreover, patients who persistently experienced higher levels of daily stressors had lower mean cortisol levels than patients who experienced lower levels of daily stressors. Results suggest that daily stressors influence disease outcome in patients with psoriasis by affecting cortisol levels at moments of high stress. Furthermore, patients with persistently high levels of stressors seem to have a specific psychophysiological profile of lowered cortisol levels and may be particularly vulnerable to the influence of stressors on their psoriasis. [ABSTRACT FROM AUTHOR]

Background Microarray studies on the epidermal transcriptome in psoriasis and atopic dermatitis (AD) have revealed genes with disease-specific expression in keratinocytes of lesional epidermis. These genes are possible candidates for disease-specific pathogenetic changes, but could also provide a tool for molecular diagnostics of inflammatory skin conditions in general. Objectives To analyse if gene expression signatures as found in purified epidermal cells from AD are also present in other eczematous conditions such as allergic and irritant contact dermatitis. Methods We used real-time quantitative polymerase chain reaction, immunohistochemistry and bioinformatics to investigate gene expression in different forms of eczema. Normal epidermis and psoriatic epidermis were analysed for comparison. Results Carbonic anhydrase II was highly induced in epidermis from all forms of eczema but not in psoriasis. Remarkably, the presumed neuron-specific Nel-like protein 2 showed a strong induction only in AD epidermis. Interleukin-1F9, elafin, β-defensin-2 and vanin-3 were strongly induced in psoriasis, but not in any type of eczema. High levels of the chemokines CCL17 and CXCL10 were predominantly found in epidermis of allergic contact dermatitis. The chemokine CXCL8 was highly expressed in psoriasis, AD and allergic contact dermatitis, but not in irritant contact dermatitis. Cluster analysis or multinomial logistic regression indicated that expression levels of a set of seven genes are a strong predictor of the type of inflammatory response. Conclusions These observations contribute to molecular diagnostic criteria for inflammatory skin conditions. [ABSTRACT FROM AUTHOR]

Background The antiprotease activity of cystatin M/E regulates skin barrier formation, as it inhibits the activity of cathepsin V, cathepsin L and legumain, thereby controlling the processing of transglutaminase 3. Misregulation of this pathway by unrestrained protease activity, as seen in cystatin M/E-deficient mice, leads to abnormal stratum corneum and hair follicle formation, and severe disturbance of skin barrier function. Objectives Our major aim was to make a quantitative analysis of the expression of all players of this pathway in the epidermis of patients with inflammatory skin diseases. A second aim was to determine if reconstructed human skin could be used as an in vitro model system to investigate this pathway. Methods Autopsy material from normal human tissues, biopsies from normal skin of healthy volunteers, and lesional skin from patients with atopic dermatitis and psoriasis were used to study the expression of the above-mentioned molecules at the mRNA level by quantitative real-time polymerase chain reaction. Localization of the protein was performed by immunofluorescence microscopy, and expression was quantitated by image analysis. Results In skin, cystatin M/E is expressed at relatively higher levels than its target proteases, when compared with other tissues, which emphasizes its prominent role in cutaneous biology. We found decreased expression of cystatin M/E and cathepsin V in lesional atopic dermatitis and psoriasis epidermis at the mRNA level as well as the protein level. Cathepsin L and transglutaminase 3 were increased at the transcriptional level; however, this was not reflected by higher protein levels. Interestingly, the expression of all these molecules in reconstructed skin was qualitatively and quantitatively similar to the in vivo situation. Conclusions Disturbance of the cystatin M/E – cathepsin pathway could contribute to the dysregulated skin barrier function observed in inflammatory dermatoses. Human reconstructed skin appears to be a valuable model to study this novel biochemical pathway in vitro. [ABSTRACT FROM AUTHOR]

Background There is increasing evidence that stressors contribute to the severity of chronic inflammatory diseases such as psoriasis. However, much less is known about possible individual differences between patients in their stress reactivity, particularly the role of cognitive and behavioural factors, such as the role of worrying or scratching behaviour, in reaction to itch. Objectives To investigate the direct and moderating role of individual stress reactivity factors, particularly of cognitive and behavioural patterns of worrying and scratching, on the relationship between daily stressors and changes in disease severity [Psoriasis Area and Severity Index (PASI)] and itch in patients with psoriasis. Methods Patients were followed for 6 months through monthly clinical and self-reported measures of daily stressors, itch, disease severity and individual reactivity factors. Data from 62 patients were suitable for analysis. Results Cognitive and behavioural patterns of worrying and scratching were both independently related to an increase 4 weeks later in disease severity (PASI) and itch, at moments when patients experienced a high level of daily stressors. At these moments, stressors also interacted with vulnerability factors, showing that patients with more daily stress and high worrying and scratching had particularly worsened disease severity and itch. Conclusions Patients with high levels of worrying and scratching are most vulnerable to the impact of stressors on their psoriasis, particularly at highly stressful periods. [ABSTRACT FROM AUTHOR]

There is evidence to suggest that genetic factors play an important role in the development of basal cell carcinomas (BCCs), and that skin neoplasms might be a sign for a genetic predisposition to cancer. We investigated whether the incidence of visceral and skin malignancies among first-degree relatives of BCC-patients was increased. Postal questionnaires were sent to 249 BCC-patients, who were divided into two groups (young = BCC under the age of 51 years and older = BCC over the age of 50 years), and asked them about cancer in their first-degree relatives. The reported numbers of cancer among the relatives were compared with the expected numbers based on sex and age-specific population-based incidence rates. The accuracy of the reported diagnoses was verified. A total of 157 BCC-patients reported 277 malignancies in 1,272 relatives. The incidence of the following cancers was higher than expected in relatives from young BCC-patients: bone and soft tissue (O/E = 3.91; 95% CI: 1.43–8.66), skin (O/E = 2.13; 95% CI: 1.30–3.29) and digestive tract (O/E = 1.59; 95% CI: 1.10–2.23). In relatives of older BCC-patients, only the incidence of digestive tract cancer was higher than expected (O/E = 1.44; 95% CI: 1.08–1.89). Diagnoses that were verified turned out to be accurate in 87% of the cases. This study suggests that the risk of certain cancers, particularly that of the digestive tract, in first-degree relatives of BCC-patients is increased. These findings may indicate a genetic predisposition to both skin and visceral malignancies in this patient group. [ABSTRACT FROM AUTHOR]

Abstract: This review presents an overview of myopathies and inherited connective tissue disorders that are caused by defects in or deficiencies of molecules within the extracellular matrix (ECM). We will cover the myopathies caused by defects in transmembrane protein complexes (dystroglycan, sarcoglycan, and integrins), laminin, and collagens (collagens VI, XIII, and XV). Clinical characteristics of several of these myopathies imply skin and joint features. We subsequently describe the inherited connective tissue disorders that are characterized by mild to moderate muscle involvement in addition to the dermal, vascular, or articular symptoms. These disorders are caused by defects of matrix-embedded ECM molecules that are also present within muscle (collagens I, III, V, IX, lysylhydroxylase, tenascin, fibrillin, fibulin, elastin, and perlecan). By focussing on the structure and function of these ECM molecules, we aim to point out the clinical and molecular overlap between the groups of disorders. We argue that clinicians and researchers dealing with myopathies and inherited connective tissue disorders should be aware of this overlap. Only a multi-disciplinary approach will allow full recognition of the wide variety of symptoms present in the spectrum of ECM defects, which has important implications for scientific research, diagnosis, and for the treatment of these disorders. [Copyright &y& Elsevier]

We analysed the diversity of tenascin-X (TNX) species in serum and studied parameters that could affect determination of TNX levels in serum. Using western blot analysis we identified at least seven distinct TNX species, ranging from 75 kDa to the presumably full-length 450 kDa form. Purification of serum TNX followed by sequence analysis positively identified two major TNX species of 75 and 140 kDa. We found that serum TNX binds to tropoelastin but not to fibrillar collagens. We conclude that serum TNX is composed of distinct molecular species that retain functional activity. [ABSTRACT FROM AUTHOR]

Deficiency of the extracellular matrix protein tenascin-X (TNX) causes a recessive form of Ehlers‐Danlos syndrome (EDS) characterized by hyperextensible skin and hypermobile joints. It is not known whether the observed alterations of dermal collagen fibrils and elastic fibers in these patients are caused by disturbed assembly and deposition or by altered stability and turnover. We used biophysical measurements and immunofluorescence to study connective tissue properties in TNX knockout and wild-type mice. We found that TNX knockout mice, even at a young age, have greatly disturbed biomechanical properties of the skin. No joint abnormalities were noted at any age. The spatio-temporal expression of TNX during normal mouse skin development, during embryonic days 13–19 (E13–E19), was distinct from tropoelastin and the dermal fibrillar collagens type I, III, and V. Our data show that TNX is not involved in the earliest phase (E10–E14) of the deposition of collagen fibrils and elastic fibers during fetal development. From E15 to E19, TNX starts partially to colocalize with the dermal collagens and elastin, and in adult mice, TNX is present in the entire dermis. In adult TNX knockout mice, we observed an apparent increase of elastin. We conclude that TNX knockout mice only partially recapitulate the phenotype of TNX-deficient EDS patients, and that TNX could potentially be involved in maturation and/or maintenance of the dermal collagen and elastin network. [ABSTRACT FROM AUTHOR]

Zweers MC, Dean WB, van Kuppevelt TH, Bristow J, Schalkwijk J. Elastic fiber abnormalities in hypermobility-type Ehlers–Danlos syndrome patients with tenascin-X mutations.Ehlers–Danlos syndrome (EDS) is a heterogeneous group of connective tissue disorders with characteristic skin and joint involvement. The concept that EDS is a disease of fibrillar collagen was challenged by the identification of a clinically distinct, recessive type of EDS caused by deficiency of the extracellular matrix protein tenascin-X (TNX). Interestingly, haploinsufficiency of TNX is associated with the dominantly inherited hypermobility type of EDS. In this study, we examined whether missense mutations in theTNXgene can account for some of the cases of hypermobility type EDS. Furthermore, we studied whether missense mutations or heterozygosity for truncating mutations in theTNXgene lead to alterations in the dermal connective tissue. Sequence analysis revealed three missense mutations in TNX in hypermobility type EDS patients, which were not present in 192 control alleles. Morphometric analysis of skin biopsies of these patients showed altered elastic fibers in one of them, suggesting that this missense mutation is disease causing. Light microscopic and ultrastructural changes of the elastic fibers were observed in TNX-haploinsufficient hypermobility type EDS patients, which were not found in hypermobility type EDS patients in whom TNX mutations were excluded. Our results indicate that the observed alterations in elastic fibers are specific for hypermobility type EDS patients with mutations of TNX. [ABSTRACT FROM AUTHOR]

Oral reconstructions for cleft palate repair are often complicated by a shortage of mucosal tissue. This shortage causes scar tissue formation leading to impaired growth of the dento-maxillary complex. The overall aim of our research is to develop a substitute, which limits the iatrogenic effects of cleft palate surgery. This study describes the culture and characterization of mucosal substitutes containing keratinocytes. Epidermal and oral keratinocytes from a beagle dog were cultured on several skin-derived and collagen-based substrates. Oral keratinocytes cultured on the skin-derived substrates closely resembled normal oral epithelium of the dog. A multi-layered epithelium was formed showing parakeratosis, expression of cytokeratin 16 and the formation of a basement membrane. Epidermal keratinocytes cultured on the skin-derived substrates formed an epithelium which was similar to dog epidermis. In contrast, keratinocytes cultured on the collagen-based substrates invaded the substrate without the formation of a multi-layered epithelium.In conclusion, this study shows that oral canine keratinocytes cultured on skin-derived substrates exhibit a tissue organization that resembles normal oral mucosa. This type of mucosal substitute will therefore be used in further studies for implantation on the palate of beagle dogs. These studies might eventually lead to an improvement of cleft palate surgery in humans. [Copyright &y& Elsevier]

Background Cystatins are natural and specific inhibitors of endogenous mammalian lysosomal cysteine proteinases and exogenous microbial cysteine proteinases. Cystatins were shown to provide regulatory and protective functions against uncontrolled proteolysis in several disease processes. Recently we reported that cystatin M/E, which is a novel member of the cystatin gene family, has an unusually restricted expression pattern that is limited to skin. Although cystatin M/E possesses two distinct biochemical properties (it is a proteinase inhibitor and a substrate for transglutaminase) its physiological function is unknown. Disturbance of the balance between proteinases and their inhibitors can lead to irreversible damage as in chronic inflammatory reactions and tumour invasion. Objectives To examine the expression pattern of cystatin M/E in inflammatory conditions and neoplastic skin disorders in order to obtain possible clues on its function. Furthermore, we wished to determine whether cystatin M/E expression could discriminate between various types of neoplasia. Methods Biopsy material of normal skin, atopic dermatitis and psoriatic lesional skin, healing excisional wounds in healthy volunteers, and several types of epidermal neoplasia (keratoacanthoma, actinic keratosis, basal cell carcinoma and squamous cell carcinoma) were used in this study. For comparison we studied the expression of cystatin M/E in squamous neoplasias from noncutaneous origin. Affinity-purified polyclonal antibodies against cystatin M/E were used for immunohistochemical detection. Results Cystatin M/E is constitutively expressed in the stratum granulosum of normal skin, sebaceous glands, eccrine sweat glands and the infundibular epithelium of hair follicles. Expression in atopic dermatitis and psoriasis was found to extend to several layers of the stratum spinosum. In wound healing, cystatin M/E was not found in the edge of migrating keratinocytes, but it was strongly expressed in the... [ABSTRACT FROM AUTHOR]

Expression of human leukocyte elastase inhibitor, elafin, otherwise known as skin-derived antileukoproteinase inhibitor (SKALP), was investigated in normal and abnormal oral tissues using a specific anti-SKALP rabbit antiserum. Weak staining was observed in keratinizing epithelia of normal oral mucosa but not in non-keratinizing mucosa. Increased expression was also observed in the suprabasal layers of dysplastic oral epithelia and in well-differentiated squamous cell carcinoma, but not in basal cell carcinoma. A uniform strong expression was observed in all supra-basal layers of odontogenic keratocyst epithelia, except in regions where inflammatory infiltrate was adjacent to keratocyst epithelia. In contrast, elafin expression in a small number of dentigerous cysts and ameloblastomas was more patchy. The increased levels of elafin in keratocyst epithelia and dysplastic tissue may be a cellular homoeostatic response to generate a protective barrier preventing proteolytic degradation of underlying elastic tissue. [ABSTRACT FROM AUTHOR]

Introduction. Recent genome-wide association studies have identified strong genetic risk factors for psoriasis, but data on their association with age of onset are lacking. Objective. The goal of this study was to compare the association between known risk alleles and psoriasis in well-defined cohorts of juvenile and adult onset psoriasis. Methods. Based on previous studies we selected seven genes and loci associated with psoriasis. Psoriasis patients with juvenile (< 18 years) and adult onset psoriasis (>= 18 years) and controls were genotyped. Genotype frequencies were compared between controls (n=450) and all cases (n=217), and between controls and cases stratified for confirmed age of onset (juvenile onset n=85, adult onset n=80). Results. Juvenile onset psoriasis showed a significant association with single nucleotide polymorphisms (SNPs) in the ERAP1 (P=0,042) and in the IL23R locus (P=0,042), LCE3C_LCE3B deletion (P=0,003) and HLA-C*06 (P=1,72E-19) when compared with the control group. A significant association of these four genes was also demonstrated when all psoriasis cases were compared with controls. In adult onset psoriasis a significant association was found for HLA-C*06 (P=5,11E-06) and for LCE3C_LCE3B deletion (P=0,042). No associations were found for the IFIH1, IL12B and TRAF3IP2 loci. Conclusions. Notwithstanding the small cohort sizes, we could demonstrate an association with established and recently discovered genetic risk factors in juvenile onset psoriasis including genes involved in epidermal barrier function and adaptive immunity. Our data suggest that heritable factors may play a more important role in juvenile onset psoriasis than in adult onset psoriasis. [ABSTRACT FROM AUTHOR]

A letter to the editor is presented in response to the article "Recurrent Neuropathy Associated With Ehlers–Danlos Syndrome," that was published in the previous issues of the "Journal of Neurology."

Background Recent genome-wide association studies have identified several genetic risk factors for psoriasis, but data on their association with age at onset are lacking. Objectives To compare the association between known risk alleles and psoriasis in well-defined cohorts with paediatric- and adult-onset psoriasis. Methods Based on previous studies we selected seven genes and loci associated with psoriasis. Patients with paediatric-onset (< 18 years) and adult-onset psoriasis (≥ 18 years) and controls were genotyped. Genotype frequencies were compared between controls ( n = 450) and all cases ( n = 217), and between controls and cases stratified for confirmed age at onset (paediatric onset n = 80, adult onset n = 85). Results Paediatric-onset psoriasis showed a significant association with single nucleotide polymorphisms in the ERAP1 ( P = 0·042) and IL23R loci ( P = 0·042), LCE3C_LCE3B-del ( P = 0·003) and HLA-C*06 ( P = 1·72 × 10−19) when compared with the control group. A significant association of these four genes was also demonstrated when all psoriasis cases were compared with controls. In adult-onset psoriasis a significant association was found for HLA-C*06 ( P = 5·11 × 10−6) and for LCE3C_LCE3B-del ( P = 0·042). No associations were found for the IFIH1, IL12B and TRAF3IP2 loci. Conclusions Notwithstanding the small cohort sizes, we demonstrated an association with established and recently discovered genetic risk factors in paediatric-onset psoriasis including genes involved in epidermal barrier function and adaptive immunity. Our data suggest that heritable factors may play a more important role in paediatric-onset psoriasis than in adult-onset psoriasis. [ABSTRACT FROM AUTHOR]