Nonlesional Skin Of Patients Research Articles

Elevation of serum squamous cell carcinoma antigen 2 in patients with psoriasis: associations with disease severity and response to the treatment.

Squamous cell carcinoma antigen (SCCA) belongs to the ovalbumin-serpin family and is a known tumour marker. Expression of SCCA is upregulated in the serum and skin of patients with psoriasis. The aim of this study was to determine SCCA2 levels in association with disease severity and treatment efficacy in patients with psoriasis. Patients with psoriasis (n=123) and healthy controls (n=25) were enrolled in this prospective cross-sectional study. Enzyme-linked immunosorbent assay (ELISA) analysis was performed to determine serum SCCA2 levels. SCCA2 expression in skin was evaluated using immunohistochemical analysis. Serum SCCA2 levels were compared with Psoriasis Area Severity Index (PASI) scores. The effect of treatment on serum SCCA2 levels was assessed using serial examinations. Induction of SCCA2 by several psoriatic cytokines in human keratinocytes was evaluated. The serum levels of SCCA2 were significantly higher in patients with psoriasis than healthy controls and correlated well with disease severity. Increased SCCA2 staining was observed in lesional skin but not in nonlesional skin of patients with psoriasis. In addition, SCCA2 expression levels in skin correlated with serum concentrations of SCCA2. SCCA2 significantly decreased according to improvement of PASI scores. Interleukin (IL)-17 and IL-22 synergistically increased the production of SCCA2 at both mRNA and protein levels in human keratinocytes. Significant elevation of SCCA2 is associated with disease severity and reflects treatment efficacy. SCCA2 may be a useful biomarker in psoriasis, reflecting T-helper 17-type inflammation - the main determinant of the severity of psoriasis.

Stratum Corneum Lipids: Their Role for the Skin Barrier Function in Healthy Subjects and Atopic Dermatitis Patients.

Human skin acts as a primary barrier between the body and its environment. Crucial for this skin barrier function is the lipid matrix in the outermost layer of the skin, the stratum corneum (SC). Two of its functions are (1) to prevent excessive water loss through the epidermis and (2) to avoid that compounds from the environment permeate into the viable epidermal and dermal layers and thereby provoke an immune response. The composition of the SC lipid matrix is dominated by three lipid classes: cholesterol, free fatty acids and ceramides. These lipids adopt a highly ordered, 3-dimensional structure of stacked densely packed lipid layers (lipid lamellae): the lateral and lamellar lipid organization. The way in which these lipids are ordered depends on the composition of the lipids. One very common skin disease in which the SC lipid barrier is affected is atopic dermatitis (AD). This review addresses the SC lipid composition and organization in healthy skin, and elaborates on how these parameters are changed in lesional and nonlesional skin of AD patients. Concerning the lipid composition, the changes in the three main lipid classes and the importance of the carbon chain lengths of the lipids are discussed. In addition, this review addresses how these changes in lipid composition induce changes in lipid organization and subsequently correlate with an impaired skin barrier function in both lesional and nonlesional skin of these patients. Furthermore, the effect of filaggrin and mutations in the filaggrin gene on the SC lipid composition is critically discussed. Also, the breakdown products of filaggrin, the natural moisturizing factor molecules and its relation to SC-pH is described. Finally, the paper discusses some major changes in epidermal lipid biosynthesis in patients with AD and other related skin diseases, and how inflammation has a deteriorating effect on the SC lipids and SC biosynthesis. The review ends with perspectives on future studies in relation to other skin diseases.

Heat Shock Protein-70 Expression in Vitiligo and its Relation to the Disease Activity.

Background:Vitiligo is a progressive depigmenting disorder characterized by the loss of functional melanocytes from the epidermis. The etiopathogenesis of vitiligo is still unclear. Heat shock proteins (HSPs) are prime candidates to connect stress to the skin. HSPs were found to be implicated in autoimmune diseases such as rheumatoid arthritis and other skin disorders as psoriasis.Aim and Objectives:The aim of this study was to map the level of HSP-70 in vitiligo lesions to declare its role in the pathogenesis and activity of vitiligo.Materials and Methods:The study included thirty patients with vitiligo and 30 age- and sex-matched healthy controls. Vitiligo patients were divided as regards to the disease activity into highly active, moderately active, and inactive vitiligo groups. Skin biopsies were taken from the lesional and nonlesional skin of patients and from the normal skin of the controls. HSP-70 messenger RNA (mRNA) expression was estimated using quantitative real-time polymerase chain reaction.Results:Our analysis revealed a significantly higher expression of HSP-70 mRNA in lesional skin biopsies from vitiligo patients compared to nonlesional skin biopsies from vitiligo patients (P < 0.001) and compared to skin biopsies from healthy controls (P < 0.001). The level of HSP-70 was not found to be correlated with age, sex, or disease duration. The expression of HSP-70 was correlated with the disease activity and patients with active vitiligo showed higher mean HSP-70 level compared to those with inactive disease.Conclusions:HSP-70 plays a role in the pathogenesis of vitiligo and may enhance the immune response in active disease.

The role of cyclooxygenase-2 and prostaglandin E2 in the pathogenesis of cutaneous lichen planus

Lichen planus (LP) is an inflammatory disease of the skin and mucous membranes. Autoimmunity has been suggested as a possible cause of this disease. The cyclooxygenase enzymes (COX-1, COX-2) are the key enzymes in the conversion of arachidonic acid into prostaglandins. Prostaglandin E2 (PGE2), a key product of COX-2, has an immunomodulatory role. To map levels of COX-2 and PGE2 in cutaneous LP lesions and evaluate their role in the pathogenesis of the disease. In total, 31 patients with classic cutaneous LP and 30 age- and sex-matched healthy controls were enrolled. Skin biopsies were taken from the lesional and nonlesional skin of patients, and from the normal skin of controls. COX-2 mRNA expression was detected by real-time reverse transcription quantitative PCR, and PGE2 was detected by ELISA in skin biopsies from patients and controls. Our analysis revealed a significantly higher expression of COX-2 mRNA and PGE2 in the LP skin biopsies compared with the control biopsies (P < 0.001 and P < 0.001, respectively). Lesional biopsies showed significantly higher expression of COX-2 mRNA and PGE2 compared with nonlesional biopsies. The levels of COX-2 and PGE2 were not found to be correlated with age, sex or disease duration. COX-2 and its product PGE2 are strongly expressed in LP skin lesions, indicating that they have a role in the pathogenesis of LP through their immunomodulatory effects.

Interactome analysis of gene expression profile reveals potential novel key transcriptional regulators of skin pathology in vitiligo.

Selective destruction of epidermal melanocytes is central to vitiligo (VL), a common acquired, autoimmune depigmentory disorder of the skin. Like other autoimmune diseases, the pathogenesis of VL is obscure and both multifactorial and polygenic. The prevailing theory is that VL may be part of an autoimmune diathesis. To evaluate mechanisms underlying disease development and progression, we studied genome-wide gene expression from lesional and non-lesional skin of patients with non-segmental VL. Unbiased clustering and principal components analyses reveals a 'lesional pathology'-based signature. Pathway-based analyses of the differentially expressed genes underscore processes such as melanocyte development and cell cycle as central drivers of the disease state. Interactome analysis identifies several key transcriptional regulators potentially affecting disease pathogenesis both within and 'hidden' from the data set. Finally, two genes within six identified transcriptional 'hot spots' coincide with previous VL-associated genetic elements. The remaining genes in the 'hot spots' offer an additional set of potential disease-linked loci that may help to guide future studies aimed at identifying disease risk genes.

Assessment of gene expression levels of proopiomelanocortin (POMC) and melanocortin-1 receptor (MC1R) in vitiligo.

Proopiomelanocortin (POMC) and melanocortin 1 receptor (MC1R) are regulators of melanogenesis and pigmentation. Our objective was to estimate their levels, searching for a possible role of the melanocortin system in vitiligo. This study included 40 vitiligo patients and 40 controls. Skin biopsies were taken from lesional and non-lesional skin of patients and from the non-sun exposed skin of controls to detect the expression of POMC and MC1R using quantitative real-time polymerase chain reaction. Both factors were significantly lower in lesional than non-lesional skin and controls, while they were significantly higher in non-lesional skin than in controls. There was a statistically significant positive correlation between lesional levels of POMC and MC1R, as well as between non-lesional levels of POMC and MC1R in the patients. On the other hand, we found a statistically significant negative correlation between the lesional and non-lesional levels of POMC, as well as between the lesional and non-lesional levels of MC1R in the patients. As a conclusion, the melanocortin system could play a role in the pathogenesis of vitiligo or could be affected as the end result of the disease.

Mast-cell interleukin-1β, neutrophil interleukin-17 and epidermal antimicrobial proteins in the neutrophilic urticarial dermatosis in Schnitzler's syndrome.

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. Here we investigated the cellular source of proinflammatory mediators in the skin of patients with SchS. 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 invivoIL-1β, IL-17 and antimicrobial protein (AMP) expression in resident skin cells and infiltrating cells. In addition we investigated the invitro effect of IL-1β, IL-17 and polyinosinic-polycytidylic acid (poly:IC) stimulation on cultured epidermal keratinocytes. 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. 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.

RNA sequencing atopic dermatitis transcriptome profiling provides insights into novel disease mechanisms with potential therapeutic implications

Genomic profiling of lesional and nonlesional skin of patients with atopic dermatitis (AD) using microarrays has led to increased understanding of AD and identification of novel therapeutic targets. However, the limitations of microarrays might decrease detection of AD genes. These limitations might be lessened with next-generation RNA sequencing (RNA-seq). We sought to define the lesional AD transcriptome using RNA-seq and compare it using microarrays performed on the same cohort. RNA-seq and microarrays were performed to identify differentially expressed genes (criteria: fold change, ≥ 2.0; false discovery rate ≤ 0.05) in lesional versus nonlesional skin from 18 patients with moderate-to-severe AD, with real-time PCR (RT-PCR) and immunohistochemistry used for validation. Both platforms showed robust disease transcriptomes and correlated well with RT-PCR. The common AD transcriptome identified by using both techniques contained 217 genes, including inflammatory (S100A8/A9/A12, CXCL1, and 2'-5'-oligoadenylate synthetase-like [OASL]) and barrier (MKi67, keratin 16 [K16], and claudin 8 [CLDN8]) AD-related genes. Although fold change estimates determined by using RNA-seq showed somewhat better agreement with RT-PCR (intraclass correlation coefficient, 0.57 and 0.70 for microarrays and RNA-seq vs RT-PCR, respectively), bias was not eliminated. Among genes uniquely identified by using RNA-seq were triggering receptor expressed on myeloid cells 1 (TREM-1) signaling (eg, CCL2, CCL3, and single immunoglobulin domain IL1R1 related [SIGIRR]) and IL-36 isoform genes. TREM-1 is a surface receptor implicated in innate and adaptive immunity that amplifies infection-related inflammation. This is the first report of a lesional AD phenotype using RNA-seq and the first direct comparison between platforms in this disease. Both platforms robustly characterize the AD transcriptome. Through RNA-seq, we unraveled novel disease pathology, including increased expression of the novel TREM-1 pathway and the IL-36 cytokine in patients with AD.

Distinct behavior of human Langerhans cells and inflammatory dendritic epidermal cells at tight junctions in patients with atopic dermatitis

The stratum corneum and tight junctions (TJs) form physical barriers in the epidermis. Dendrites of activated Langerhans cells (LCs) extend beyond the TJs to capture external antigens in mice. LCs and inflammatory dendritic epidermal cells (IDECs) are observed in the skin of patients with atopic dermatitis (AD). We sought to investigate the characteristics of LCs and IDECs and the distribution of their antigen capture receptors in relation to TJs in normal and AD skin. We characterized the interactions of LCs and IDECs with TJs and the expression patterns of langerin and FcεRI by using whole-mount epidermal sheets from healthy subjects and patients with AD, ichthyosis vulgaris, and psoriasis vulgaris. As in mouse skin, activated LCs penetrate TJs in human skin. The number of LCs with TJ penetration increased approximately 5-fold in erythematous lesional skin of patients with AD but not in nonlesional skin of patients with AD or lesions of patients with ichthyosis vulgaris or psoriasis. Incontrast, IDECs localized in the lower part of the epidermis, and their dendrites extended horizontally without penetration through TJs. Although langerin accumulated on the tips of dendrites of activated LCs, FcεRI was expressed diffusely on the cell surfaces on LCs and IDECs in lesional skin from patients with AD. These findings highlight interesting differences between LCs and IDECs in epidermis of patients with AD, where LCs, but not IDECs, extend dendrites through the TJs, likely to capture antigens from outside the TJ barrier with a polarized distribution of langerin but not FcεRI. These behavioral differences between skin dendritic cells might reflect an important pathophysiology of AD.

Atopic dermatitis - all you can do from the outside

Atopic dermatitis (AD) affects both the epidermal barrier and the immune system and, as such, therapy needs to address both. Skin cleansing supported by emollients and moisturizers is the primary topical therapy when treating patients with AD. However, it should be remembered that the direct use of emollients on inflamed skin is poorly tolerated and that the flares need to be treated effectively, usually by topical corticosteroids (TCS) and/or topical calcineurin inhibitors (TCI). This contribution outlines a number of strategies for effectively managing AD, from reactive therapy using TCS and TCI to proactive therapy. Proactive therapy is an alternative, evidence-based, immunologically founded treatment approach, based on the fact that normal-looking, nonlesional skin of patients with AD is not normal. The advantage of the proactive approach is that the patients are in control of their disease and are actively involved in its management. The avoidance of external irritants is recommended wherever possible.

Skin miRNA profiling reveals differentially expressed miRNA signatures from non-segmental vitiligo patients

miRNAs are small conserved non-coding RNA molecules that post-transcriptionally regulate gene expression by targeting the 3’ UTR of specific mRNA for degradation or translational repression. miRNAs have been shown to be promising biomarkers for different diseases. At present, the expression and function of miRNAs in human skin is largely unknown. The aim of the present study was to detect the differentially expressed miRNAs in non-segmental vitiligo (NSV) patients and to explore the potential role of these miRNAs in vitiligo pathogenesis. We performed the whole miRNA profiling of lesional as well as non-lesional skin from four NSV patients and four healthy skin samples from controls using TaqMan® Low Density Array. Our results suggest that 38 miRNAs were differentially expressed in the skin of patients compared to controls. We identified 13 miRNAs which were significantly differentially expressed in lesional skin of patients compared to healthy control skin. Further, 29 miRNAs were found to be significantly differentially expressed between non-lesional skin of patients and healthy control skin. Interestingly, three miRNAs were specifically down-regulated in the lesional skin compared to non-lesional skin from patients with NSV. In conclusion, for the first time the present study suggests the crucial role of differentially expressed miRNAs in NSV patients from Gujarat.

Diverse T Cell Responses Lead To The Different Manifestations Of Cutaneous Graft-Versus-Host Disease

Graft-versus-host disease (GVHD) is a major complication of allogeneic hematopoietic stem cell transplantation (HCT). GVHD is classified into an acute (aGVHD) and a chronic form (cGVHD) based on NIH-defined, clinical criteria. In skin, aGVHD presents as a maculopapular rash, while cGVHD shows at the beginning the signs of lichenoid tissue inflammation (chronic inflammatory GVHD, ciGVHD) and, later, exhibits scleroderma-like features (chronic sclerotic GVHD, csGVHD). Mechanisms involved in the initiation and propagation of the different forms of GVHD are a main focus of HCT research, but remain controversially discussed. Acute GVHD has long been thought to mainly involve a type 1 T cell response, but more recent data have shown an involvement of Th2, Th17 and Treg cells. These T cell subsets, and particularly an altered regulatory T cell homeostasis, have also been reported to play a role in chronic GVHD, the pathogenesis of which is much less understood. Taken together, it is unclear which exact mechanisms are operative in the T cell immunopathogenesis of cutaneous GVHD. In this study, we searched for cellular and molecular patterns that would allow us to distinguish between the different forms of cutaneous GVHD and to draw conclusions about the pathomechanisms involved. To address this issue, we collected lesional skin biopsies from patients diagnosed with aGVHD (n=25), ciGVHD (n=17) and csGVHD (n=7). Clinical grading of acute and chronic GVHD was performed according to the modified Glucksberg criteria and the NIH consensus criteria, respectively. 14 HCT recipients underwent serial skin biopsies at different time points prior/after HCT (prior/after conditioning, day 20-30 post-HCT, day 100-120 post-HCT). Skin biopsies obtained were subjected to phenotypic and functional analyses. The cellular infiltrate was assessed by immunofluorescence stainings; interleukins and chemokines were measured by real-time RT-PCR. Cytokine secretion profiles of stimulated T cells from collagenase-digested GVHD skin biopsies were analyzed by intracellular flow cytometry. While CD4+ and CD8+ T cells dominated the inflammatory infiltrate in both acute and chronic GVHD skin lesions, the analysis of the quality of the T cell-mediated immune response revealed striking differences. In acute cutaneous GVHD, we found a “Th2 signature” as evidenced by highly increased transcripts of Th2 cytokines (IL-4, IL-5 and IL-13) and chemokines (CCL17, CCL20). Surprisingly, we also observed a strong up-regulation of IL-22, but not IL-17 mRNA, which was paralleled by an increase of IL-22-single-producing CD4+ T cells. IL-17/IL-22 double-positive T cells were almost absent. In sharp contrast to aGVHD, the immune response occurring in ciGVHD showed a mixed Th1/Th17 signature. This was evidenced by an up-regulation of Th1/Th17 cytokine (IFN-γ, IL-12/IL-23p40 and IL23p19) and chemokine transcripts (CCL5, CCR5, CXCL9, CXCL10). In accordance with this finding, increased numbers of IFN-ү- and IL-17-single-producing CD8+ T cells infiltrated ciGVHD skin lesions.Chronic sclerotic GVHD exhibited distinct features, including an abundance of mast cells and a down-regulation of T cell cytokines and chemokines relative to normal skin. In an attempt to identify a factor predicting the occurrence of acute cutaneous GVHD, we analyzed the cellular and molecular signatures in skin of HCT recipients before GVHD onset. In accordance with the finding of a Th2 response occurring in aGVHD, levels of TSLP, a keratinocyte-derived cytokine skewing the immune response towards a Th2 direction, were increased at day 20 after HCT in non-lesional skin of patients who would later develop aGVHD. In conclusion, the present study provides new insights into the diverse pathomechanisms operative in the acute and chronic form of cutaneous GVHD, respectively. Our findings allow to more accurately distinguish aGVHD from ciGVHD based on different cellular and molecular patterns. The analysis of TSLP expression in skin (before disease onset) could be helpful in identifying HCT recipients at risk for developing acute cutaneous GVHD. Disclosures: No relevant conflicts of interest to declare.

Epicutaneous application of house dust mite induces thymic stromal lymphopoietin in nonlesional skin of patients with atopic dermatitis

Epicutaneous application of house dust mite induces thymic stromal lymphopoietin in nonlesional skin of patients with atopic dermatitis

Mammalian target of rapamycin and its downstream signalling components are activated in psoriatic skin

Mammalian target of rapamycin (mTOR) signalling integrates signals leading to cellular growth, proliferation and differentiation. Disturbance of this tightly regulated interplay leads to malignancies, as reflected by altered mTOR signalling in epidermal tumours. As psoriatic keratinocytes also show features of perturbed cell growth and differentiation, the question arises as to whether mTOR signalling also plays a role in the pathogenesis of psoriasis. To investigate the activation status of mTOR signalling components in psoriasis. Biopsies from lesional and nonlesional skin of patients with psoriasis (n = 10), as well as samples from healthy donors (n = 3), were analysed by immunohistochemistry and Western blot, utilizing antibodies detecting phosphorylated mTOR, phospho-S6 kinase and phospho-S6 ribosomal protein. We found mTOR and its downstream signalling molecule, the ribosomal protein S6, to be activated in lesional psoriatic skin. While mTOR is activated throughout the whole epidermis, with particularly strong activation in the basal layer, S6 is active in suprabasal layers of differentiating keratinocytes. Altogether these results suggest a role for mTOR signalling in the epidermal changes leading to the psoriatic phenotype. mTOR inhibition might be a mode of action to explore in developing innovative antipsoriatic drugs.

CD8+ T Cells in the Lesional Skin of Atopic Dermatitis and Psoriasis Patients Are an Important Source of IFN-γ, IL-13, IL-17, and IL-22

Although CD4(+) T cells are known to contribute to the pathology of atopic dermatitis (AD) and psoriasis, the role of CD8(+) T cells in these diseases remains poorly characterized. The aim of this study was to characterize the cytokine production of T cells from AD and psoriasis skin. We found that CD4(+) T cells isolated from AD skin were largely Th2 (T helper type 2) biased, in agreement with prior reports. However, we also observed large numbers of CD8(+) T cells producing IL-13, IFN-γ, and IL-22. We observed increased numbers of CD8(+) T cells isolated from AD skin, and immunohistochemistry studies confirmed the presence of CD8(+) T cells in the dermis and epidermis of AD skin lesions. Surprisingly, T-cell cytokine production was similar in the lesional and nonlesional skin of patients with AD. T cells from psoriatic lesional skin predominantly produced IFN-γ, IL-17, and IL-22, in agreement with prior studies. However, in addition to Th17 cells, we observed high percentages of CD8(+) T cells that produced both IL-22 and IL-17 in psoriatic skin lesions. Our findings demonstrate that CD8(+) T cells are a significant and previously unappreciated source of inflammatory cytokine production in both AD and psoriasis.

Defects of filaggrin-like proteins in both lesional and nonlesional atopic skin

Atopic dermatitis (AD) is a chronic inflammatory skin disease characterized by a disturbed epidermal barrier. In a subset of patients, this is explained by nonsense mutations in the gene encoding filaggrin (FLG). We sought to evaluate the respective role of FLG mutations and proinflammatory cytokines and to assess the expression of FLG, hornerin (HRNR), and FLG2, 2 FLG-like proteins, which are involved in epidermal barrier functions, in normal skin and both lesional and nonlesional skin of patients with AD. An FLG-genotyped cohort of 73 adults with AD and 73 aged-matched control subjects was analyzed by using immunohistochemistry and immunoblotting. Normal primary human keratinocytes were differentiated in either the absence or presence of IL-4, IL-13, and IL-25. Compared with control subjects, FLG, HRNR, and FLG2 were detected at significantly lower levels in the skin of patients with AD, irrespective of their FLG genotype. The reduction was greater in lesional compared with nonlesional skin. In addition, the proFLG/FLG ratio was found to be higher in the skin of wild-type patients than in control subjects. Cytokine treatment of keratinocytes induced a dramatic reduction in FLG, FLG2, and HRNR expression both at the mRNA and protein levels. The stratum corneum of lesional but also clinically unaffected skin of adults with AD is abnormal, with reduced expression of FLG and FLG-like proteins. In addition to nonsense mutations, proinflammatory cytokines and some defects in the proFLG processing can contribute to the FLG downregulation. Our study suggests that skin inflammation reduces the expression of FLG-like proteins, contributing to the AD-related epidermal barrier dysfunction.

Gene Expression Analysis of the Corticotrophin-releasing Hormone-proopiomelanocortin System in Psoriasis Skin Biopsies

The corticotrophin-releasing hormone-proopiomelanocortin (CRH-POMC) system in the skin coordinates pigmentation and the immune response. The aim of this study was to evaluate the regulatory role of the neuroendocrine system in the pathogenesis of psoriasis. Using quantitative real-time-PCR, mRNA expression levels of 15 genes related to the CRH-POMC system were measured in punch biopsies from lesional and non-lesional skin of patients with psoriasis and from skin of healthy control subjects. Statistically significant up-regulation of POMC, CRH receptor type 1, melanin-concentrating hormone receptor (MCHR1) and melanocortin receptors 2, 3 and 4 mRNA expression in lesional and in non-lesional skin compared with healthy control samples were established. Tyrosinase (TYR), T(Y)RP-1 and ASIP genes were statistically significantly down-regulated in lesional and non-lesional skin of psoriasis samples compared with healthy subjects. The up-regulation of POMC, melanocortin receptors, CRH receptor type 1 and MCHR1 in the lesional and non-lesional skin of psoriasis patients supports the importance of the local CRH-POMC system in the pathogenesis of psoriasis.

Malassezia species isolated from lesional and nonlesional skin in patients with pityriasis versicolor

Objectives This study aimed to identify Malassezia species found in pityriasis versicolor (PV) patients as well as to establish whether there is any association between the various species of Malassezia isolated from lesional and from nonlesional skin of those patients. Background PV is a common, benign, superficial cutaneous fungal infection caused by Malassezia species usually characterized by hypopigmented or hyperpigmented macules and patches on the chest and back. These lesions are scaly and their color varies from red, pale, yellow brown to dark brown. Patients and methods A total of 100 patients with PV were included in the study. The samples were obtained by scraping the skin surface, both from lesional and from nonlesional skin, and then incubated on Dixon's agar. The yeast isolated were identified using conventional biochemical tests and Tween assimilation. Results Skin lesions were 100% KOH positive for Malassezia species and 10% KOH positive in healthy skin. Growth from skin lesion was obtained on Dixon's agar in 83 patients (83%). The most common species was Malassezia furfur as it was detected in 47 samples (47%), followed by Malassezia globosa (23%) and Malassezia sympodialis (13%). From healthy skin of patients, growth of Malassezia was obtained from 19 specimens, M. furfur was detected in 13%, and M. globosa was detected in only three patients (3%) and M. sympodialis in three patients (3%). Conclusion M. furfur in its mycelial phase was the predominant species involved in the etiology of PV and M. globosa was the second most common species. The most frequently isolated species from clinically healthy skin was M. furfur and was recovered from healthy skin only in yeast form. We found no difference in the distribution of Malassezia species between lesional and nonlesional skin. Furthermore, no species predominance was observed whether with hyperpigmented or hypopigmented lesions as M. fufur was the most common species in both lesions in PV patients.

Expression of CCL1 and CCL18 in atopic dermatitis and psoriasis

Recent studies have shown that chemoattractive proteins play an important role in the organization of the innate and adaptive immune responses. There are some reports that chemokine (C-C motif) ligand (CCL)1 and CCL18, members of a family of chemoattractive proteins, have increased expression in atopic dermatitis (AD). To evaluate the quantity and pattern of CCL1 and CCL18 expression in lesions and blood of patients with AD, and compare them with those of patients with psoriasis. Biopsy specimens were taken from atopic skin and normal-appearing skin of patients with AD and from the psoriatic skin only of patients with psoriasis. Quantitative real-time PCR analysis and immunohistochemistry of CCL1 and CCL18 expression were performed, and the quantities of expressed CCL1 and CCL18 in acute AD were compared with those of normal-appearing atopic skin and psoriatic skin. The serum level of CCL1 and CCL18 was assessed by ELISA. Expression of CCL1 mRNA and protein was significantly higher in the acute lesional skin of patients with AD than in their nonlesional skin or in the lesional skin of patients with psoriasis. Both CCL18 mRNA and protein were abundant in acute AD lesions and in psoriatic lesions, but were lower in the nonlesional skin of patients with AD. The serum levels of CCL1 and CCL18 were not different in patients with AD and patients with psoriasis. CCL1 is a chemokine that is associated with AD. Both CCL1 and CCL18 may play important roles in the initiation and progression of atopic skin inflammation.

Expression profile of cornified envelope structural proteins and keratinocyte differentiation-regulating proteins during skin barrier repair

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. To analyse the effect of experimental skin barrier disruption on the expression of cornified envelope structural proteins and keratinocyte differentiation-regulating proteins. 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. 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. 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.