Scalp psoriasis shows a variable clinical spectrum and in many cases poses a great therapeutic challenge. However, it remains unknown whether the immune response of scalp psoriasis differs from understood pathomechanisms of psoriasis on other skin areas. We sought to determine the cellular and mollecular phenotype of scalp psoriasis by performing a comparative analysis of scalp vs skin using lesional and nonlesional samples from 20 Caucasian subjects with untreated moderate to severe psoriasis and significant scalp involvement, and 10 control subjects without psoriasis. Our results suggest that even in the scalp psoriasis is a disease of the inter-follicular skin. The immune mechanisms that mediate scalp psoriasis were found to be similar to those involved in skin psoriasis. However, the magnitude of dysregulation, number of differentially expressed genes, and enrichment of the psoriatic genomic fingerprinting were more prominent in skin lesions. Furthermore, the scalp transcriptome showed increased modulation of several gene-sets, particularly those induced by interferon-gamma, compared with skin psoriasis which was mainly associated with activation of TNF/L-17/IL-22-induced keratinocyte response genes. We also detected differences in expression of gene-sets involving negative regulation, epigenetic regulation, epidermal differentiation, and dendritic cell or Th1/Th17/Th22-related T-cell processes.
Molecular and Cellular Profiling of Scalp Psoriasis Reveals Differences and Similarities Compared to Skin Psoriasis.
Specimen part, Disease, Disease stageView Samples
The success of TNF inhibitors for treatment of psoriasis and other inflammatory diseases was previously attributed to blockade of innate immunity. In a clinical trial using etanercept TNF blocking agent to treat psoriasis vulgaris, we used affymetrix gene arrays to analyze broad gene profiles in lesional skin at multiple timepoints during drug treatment (baseline, and weeks 1, 2, 4 and 12) compared to non-lesional skin. This analysis created a temporal model of TNF-dependent gene regulation that informs molecular mechanisms of TNF-mediated inflammation. We identified four gene clusters that were differentially down-modulated during etanercept treatment: the cluster down-regulated most rapidly contained mostly dendritic cell activation genes. Culturing human keratinocytes with TNF, IFNg and IL-17 generated a list of keratinocyte genes regulated by each cytokine. The IL-17 pathway genes were strongly down-modulated early, whereas IFNg pathway genes were not down-modulated until final disease resolution at week 12. Finally, we show that TNF blockade rapidly inhibits IL-12/IL-23 p40 subunit expression, and that p40 neutralization inhibits psoriatic dermal migr-mediated Th17 polarization. We hypothesize that etanercept inhibits myeloid dendritic cell production of IL-23, a Th17 survival cytokine, resulting in rapid downregulation of IL-17 pathway genes. This data links effects of TNF blockade on the innate immune system with the adaptive immune system.
Effective treatment of psoriasis with etanercept is linked to suppression of IL-17 signaling, not immediate response TNF genes.
Subject, TimeView Samples
Atopic dermatitis (AD) is a common inflammatory skin disease with a T(H)2 and T22 immune polarity. Despite recent data showing a genetic predisposition to epidermal barrier defects in some patients, a fundamental debate still exists regarding the role of barrier abnormalities versus immune responses in initiating the disease. An extensive study of nonlesional AD (ANL) skin is necessary to explore whether there is an intrinsic predisposition to barrier abnormalities, background immune activation, or both in patients with AD. We sought to characterize ANL skin by determining whether epidermal differentiation and immune abnormalities that characterize lesional AD (AL) skin are also reflected in ANL skin. We performed genomic and histologic profiling of both ANL and AL skin lesions (n = 12 each) compared with normal human skin (n = 10). We found that ANL skin is clearly distinct from normal skin with respect to terminal differentiation and some immune abnormalities and that it has a cutaneous expansion of T cells. We also showed that ANL skin has a variable immune phenotype, which is largely determined by disease extent and severity. Whereas broad terminal differentiation abnormalities were largely similar between involved and uninvolved AD skin, perhaps accounting for the background skin phenotype, increased expression of immune-related genes was among the most obvious differences between AL and ANL skin, potentially reflecting the clinical disease phenotype. Our study implies that systemic immune activation might play a role in alteration of the normal epidermal phenotype, as suggested by the high correlation in expression of immune genes in ANL skin with the disease severity index.
Nonlesional atopic dermatitis skin is characterized by broad terminal differentiation defects and variable immune abnormalities.
Specimen part, SubjectView Samples
In this study we used genomic profiling to characterize differences in expression of genes related to epidermal growth/differentiation and inflammatory circuits in skin lesions of psoriasis and atopic dermatitis (AD), comparing expression values to normal skin. Skin biopsies were collected from 9 patients with chronic atopic dermatitis, 15 psoriasis patients, and 9 healthy volunteers.
Broad defects in epidermal cornification in atopic dermatitis identified through genomic analysis.
Specimen part, SubjectView Samples
House dust mite/HDM atopy patch test/APT elicits positive reactions in the majority of atopic dermatitis/AD and healthy individuals. Experimental systems for new-onset/chronic AD are needed to support rapid therapeutic development, particularly since animal models representing AD pathology in humans are lacking. HDM APT historically simulated AD, but its suitability to model the emerging AD skin phenotype as Th2/Th22 polarized with Th1 and Th17 components is unknown. To assess whether HDM APT tissues reproduce acute or chronic AD, positive HDM APT (n=14) were compared with nonlesional, acute (<72hrs; n=10), and chronic phase AD biopsies (n=8), allergic contact reactions (to nickel [n=10] and fragrance [n=3]) using arrays.
Dust mite induces multiple polar T cell axes in human skin.
Specimen part, SubjectView Samples
Background: IL-17 is the defining cytokine of the Th17, Tc17, and T cell populations that plays a critical role in mediating inflammation and autoimmunity. Psoriasis vulgaris is an inflammatory skin disease mediated by Th1 and Th17 cytokines with relevant contributions of IFN-, TNF-, and IL-17. Despite the pivotal role IL-17 plays in psoriasis, and in contrast to the other key mediators involved in the psoriasis cytokine cascade that are capable of inducing broad effects on keratinocytes, IL-17 was demonstrated to regulate the expression of a limited number of genes in monolayer keratinocytes cultured in vitro.
IL-17 induces an expanded range of downstream genes in reconstituted human epidermis model.
Specimen part, TreatmentView Samples
Mycosis Fungoides (MF) is typically characterized by a mature CD4+ memory T-cell phenotype, and regarded as a helper T-cell (Th)2-skewed disease. Here, using skin samples from MF (n=21), healthy volunteers (n=17), atopic dermatitis (n=17), and psoriasis (n=9), we performed RT-PCR to show highest interleukin (IL)-32 mRNA expression in MF compared to benign inflammatory diseases, and its increasing expression with disease progression. By immunohistochemistry and immunofluorescence, we confirmed IL-32 protein expression by numerous CD3+CD4+ T-cells and some epidermotropic T-cells in MF lesions. IL-32 is expressed by MyLa cells (MF cell line) and promoted their proliferation and viability in a dose-dependent fashion. IL-32-treated MyLa and HH cells (CTCL cell line) showed upregulation of cell proliferation and survival genes. Of major 'polar' T-cell cytokines, only IFN- mRNA increases with MF progression and positively correlates with IL-32 mRNA expression levels. Th2 cytokines do not show consistent increases with MF progression nor positive correlation with IL-32 mRNA expression levels. Furthermore, by flow cytometry, IL-32 production by circulating activated T-cells in healthy individulas was found in IFN-+ and IFN-- cells but not in IL-4+ or IL-13+ cells. In conclusion, we identified IL-32+ cells as likely tumor cells in MF, and clearly showed that IL-32 mRNA expression levels increase with MF progression. We found that IL-32 mRNA expression levels in MF are significantly higher than those in other skin diseases, and that some IL-32+ T-cells are independent from defined Th subsets. Thus IL-32 may play a unique role in MF progression as an autocrine cytokine.
IL32 is progressively expressed in mycosis fungoides independent of helper T-cell 2 and helper T-cell 9 polarization.
Specimen part, Cell lineView Samples
Atopic dermatitis (AD) is the most common inflammatory skin disease, with high unmet need for new therapies that are safe for chronic use. Emerging data suggest that TH2-cytokines play important roles in a variety of allergic and atopic conditions, including asthma and AD. In early phase clinical trials, dupilumab (a fully human monoclonal antibody against IL-4R that potently blocks IL-4 and IL-13 signaling) rapidly and markedly improved clinical measures in adults with either asthma (with elevated eosinophil counts) or moderate-to-severe AD. The pathomechanisms that may be impacted by IL-4/13 blockade in these disease settings have not yet been characterized in detail.
Dupilumab improves the molecular signature in skin of patients with moderate-to-severe atopic dermatitis.
Specimen part, Treatment, Subject, TimeView Samples
Atopic dermatitis (AD) is a common disease, with an increasing prevalence. The primary pathogenesis of the disease is still elusive, resulting in lack of specific treatments. The prevailing view is that AD is a biphasic, T-cell polarized disease, with Th2 predominating acute AD, and a switch to Th1 characterizing chronic disease. Identification of factors that participate in onset of lesions and maintenance of chronic lesions is critical for development of targeted therapeutics. We performed global genomic, molecular and cellular profiling of paired non-lesional, acute, and chronic skin biopsies from ten AD patients. Onset of acute lesions is associated with a striking increase in a subset of terminal differentiation proteins, specifically the IL-22-modulated S100A7-9. Correspondingly, acute disease is associated with significant increases in gene expression levels of the major Th22- (IL-22) and Th2- (IL-4, IL-31) cytokines and Th17-regulated genes (CCL20, PI3/Elafin), without significant changes in IL-17. A lesser induction of Th1- (IFN, MX-1, CXCL9-11) associated genes was detected in acute disease. Chronic skin lesions are characterized by significantly intensified activation of Th22, Th2 and Th1. Our data establish increased expression of S100A7-9 and other epidermal genes at onset of acute AD, with parallel activation of Th2 and Th22 cytokines. Our findings suggest an absence of switch mechanism in chronic disease and instead indicate that progression to chronic lesions is associated with intensified activation of immune axes that initiate onset of acute lesions, particularly Th22 and Th2. This alters the prevailing view of pathogenesis, with important therapeutic implications.
Progressive activation of T(H)2/T(H)22 cytokines and selective epidermal proteins characterizes acute and chronic atopic dermatitis.
Age, SubjectView Samples
Purpose: provide evidence that RNA-seq can add information to transcriptome profiling already discovered by other technologies for atopic dermatitis Methods: mRNA profiles of 20 atopic dermatitis were analyzed to compare lesional and non-lesional skin, then transcriptomes found by reads were compared to Microarray and RT-PCR Results:RNA-seq provided complementary genes to AD transcriptome IL-36 and TREM-1 Conclusions: Our study represents the first analysis of lesional AD tissue by RNA-seq and comparison to microarray and RT-PCR Overall design: paired biopsies from lesional and non-lesional tissue of 20 patients sequenced by RNA-seq
RNA sequencing atopic dermatitis transcriptome profiling provides insights into novel disease mechanisms with potential therapeutic implications.
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