Project description: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 TNFâµ/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. To define the transcriptomic profile of scalp skin, punch biopsies (6 mm diameter) were obtained from 20 Caucasian patients with untreated moderate to severe psoriasis with significative scalp involvement and 10 control subjects without psoriasis (N). Lesional (LS) samples were isolated from the infiltrated border of a plaque of psoriasis. Non lesional (NL) samples were taken from scalp areas with no visible psoriasis between the infiltrated plaques.
Project description: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.
Project description:It has long been recognized that anatomic location is an important feature for defining distinct subtypes of plaque psoriasis. However, little is known about the molecular differences between scalp, palmoplantar, and conventional plaque psoriasis. To investigate the molecular heterogeneity of these psoriasis subtypes, we performed RNA-seq and flow cytometry on skin samples from individuals with scalp, palmoplantar, and conventional plaque psoriasis, along with samples from healthy control patients. We performed differential expression analysis and network analysis using weighted gene coexpression network analysis (WGCNA). Our analysis revealed a core set of 763 differentially expressed genes common to all sub-types of psoriasis. In contrast, we identified 605, 632, and 262 genes uniquely differentially expressed in conventional, scalp, and palmoplantar psoriasis, respectively. WGCNA and pathway analysis revealed biological processes for the core genes as well as subtype-specific genes. Flow cytometry analysis revealed a shared increase in the percentage of CD4+ T regulatory cells in all psoriasis subtypes relative to controls, whereas distinct psoriasis subtypes displayed differences in IL-17A, IFN-gamma, and IL-22 production. This work reveals the molecular heterogeneity of plaque psoriasis and identifies subtype-specific signaling pathways that will aid in the development of therapy that is appropriate for each subtype of plaque psoriasis.
Project description:Psoriasis is a common chronic inflammatory skin disease. Treatments lead to substantial improvement of most psoriasis plaques. However, it can be challenging to reach disease resolution in certain hard to treat areas such as scalp, and lower extremity. Here we map histologic and spatial transcriptomic differences between psoriasis lesions across different anatomical locations, to understand if differences can be linked to plaque-site specific treatment resistance. Quantitative immunohistochemical analysis and transcriptomic digital spatial profiling were performed on skin punch biopsies obtained from unaffected areas on the trunk, lesional (LS) areas of the scalp, upper extremity and lower extremity of 12 patients with psoriasis. Histological analysis showed no significant differences in epidermal thickness among LS skin from different body locations. Immunohistochemical markers (CD3, CD4, CD8, CD103, CD207, IL-12RB1, IL-17A, IL-23R, RORγt, FOXP3, and MPO) did not differ significantly between LS sites. Whole transcriptome spatial RNA profiling identified several differentially expressed genes that revealed site-specific transcriptomic differences. Notably, IL-23 signaling was significantly enriched in the lower extremity epidermis, and IL-17 signaling was more pronounced in the epidermis of LS samples. These findings highlight minimal histological and immunohistochemical variation, yet significant transcriptomic and pathway differences between psoriasis body locations, suggesting potential targets for site-specific therapeutic strategies.
Project description:To understand the mechanism of disease progression in psoriasis, we defined Asian small plaque psoriasis (small psoriasis) and Asian intermediate plaque psoriasis (intermediate psoriasis) as psoriasis subtypes with limited disease progression, and compared their cellular and molecular signatures with the classic subtype of Western large plaque psoriasis (large psoriasis; GSE30999). Transcriptome analyses in pre-treatment skin biopsies from patients with Asian small and intermediate plaque psoriasis. 12 Asian small plaque psoriasis skin biopsy tissues (7 lesional and 5 non-lesional skin) and 15 Asian intermediate plaque psoriasis skin biopsy tissues (7 lesional and 8 non-lesional skin). GCRMA (using gcrma package from R/Bioconductor) and adjusted for batch effect. The expression data was combined with Western large psoriasis (GSE30999). Using a normalization based upon quantiles, the expression data was normalized based upon a specified normalization distribution of GSE30999 (see publication for GSE67853). The complete dataset representing: (1) 12 Asian small plaque psoriasis Samples, (2) 15 Asian intermediate plaque psoriasis Samples, and (3) 130 Western large plaque psoriasis Samples from GSE30999 (re-processed), is linked below as a supplementary file.
Project description:Background: Scalp psoriasis presents distinct clinical features and treatment resistance compared to lesions on other body sites, yet its immune landscape remains poorly characterized. Methods: We performed single-cell RNA sequencing (scRNA-seq) on CD45⁺ immune cells from scalp and body plaque lesions of psoriasis patients and healthy controls. A total of 41,438 immune cells were analyzed. Downstream analyses included clustering, gene set enrichment, pseudotime trajectory inference, and cell–cell interaction modeling. Multiplex immunofluorescence was used to validate spatial co-localization. Results: Scalp psoriasis lesions exhibited a higher abundance of IL17⁺ CD8⁺ tissue-resident memory T (Tc17) cells, which co-expressed IFNG and lipid transporter FATP2 (SLC27A2). Pseudotime analysis revealed a trajectory from IL7R⁺ Trm cells toward Tc17 cells, especially enriched in the scalp. Trem2⁺ macrophages in scalp lesions showed increased expression of inflammatory mediators and MHC-I molecules. CellChat revealed enhanced MHC-I–mediated interactions between Trem2⁺ macrophages and Tc17 cells in the scalp. These interactions were confirmed by immunofluorescence, demonstrating co-localization of FATP2⁺ Tc17 and Trem2⁺ macrophages around sebaceous units. Conclusions: This study defines a scalp-specific pathogenic axis involving Trem2⁺ macrophages and FATP2⁺ Tc17 cells, potentially explaining the localization and persistence of inflammation in scalp psoriasis. Targeting lipid metabolism or specific cell–cell interactions may provide new therapeutic avenues for treatment-resistant scalp psoriasis.
Project description:To investigate differences in the kinetics of allergic contact dermatitis reactions in psoriasis patients, molecular changes in clinically non-involved skin of psoriasis patients was investigated whole genome expression arrays of clinically non-involved skin of psoriasis (n=8), lichen planus (n=3), and healthy individuals (n=7) were performed
Project description:To investigate differences in the kinetics of allergic contact dermatitis reactions in psoriasis patients, molecular changes in clinically non-involved skin of psoriasis patients was investigated
Project description:Development of a suitable mouse model would facilitate the investigation of pathomechanisms underlying human psoriasis and would also assist in development of therapeutic treatments. However, while many psoriasis mouse models have been proposed, no single model recapitulates all features of the human disease, and standardized validation criteria for psoriasis mouse models have not been widely applied. In this study, whole-genome transcriptional profiling is used to compare gene expression patterns manifested by human psoriatic skin lesions with those that occur in five psoriasis mouse models (K5-Tie2, imiquimod, K14-AREG, K5-Stat3C and K5-TGFbeta1). While the cutaneous gene expression profiles associated with each mouse phenotype exhibited statistically significant similarity to the expression profile of psoriasis in humans, each model displayed distinctive sets of similarities and differences in comparison to human psoriasis. For all five models, correspondence to the human disease was strong with respect to genes involved in epidermal development and keratinization. Immune and inflammation-associated gene expression, in contrast, was more variable between models as compared to the human disease. These findings support the value of all five models as research tools, each with identifiable areas of convergence to and divergence from the human disease. Additionally, the approach used in this paper provides an objective and quantitative method for evaluation of proposed mouse models of psoriasis, which can be strategically applied in future studies to score strengths of mouse phenotypes relative to specific aspects of human psoriasis. Global transcriptional profiling was utilized to evaluate the similarity between human psoriasis and the psoriasis-like phenotypes that develop in five mouse models (K5-Tie2, IMQ, K14-AREG, K5-Stat3C, K5-TGFbeta1) Expression patterns associated with mouse phenotypes were evaluated by comparing lesional skin from transgenic or IMQ-treated mice (n = 2-3) with normal skin obtained from control mice (n = 2-3).
Project description:Psoriasis is a chronic, debilitating, immune-mediated inflammatory skin disease. As IFN-gamma is involved in many cellular processes, including activation of T cells and dendritic cells (DCs), antigen processing and presentation, cell adhesion and trafficking, and cytokine and chemokine production, IFN-gamma-producing Th1 cells were proposed to be integral to the pathogenesis of psoriasis. Recently, IFN-gamma was shown to enhance IL-23 and IL-1 production by DCs and subsequently induce Th17 cells, important contributors to the inflammatory cascade in psoriasis lesions. To determine if IFN-gamma indeed induces the pathways leading to the development of psoriasis lesions, a single intradermal injection of IFN-gamma was administered to an area of clinically normal, non-lesional skin of psoriasis patients and biopsies were collected 24 hours later. Although there were no visible changes in the skin, IFN-gamma induced molecular and histological features characteristic of psoriasis lesions. IFN-gamma increased a number of differentially expressed genes in the skin, including many chemokines concomitant with an influx of T cells and inflammatory DCs. Furthermore, inflammatory DC products TNF, iNOS, IL-23, and TRAIL were present in IFN-gamma-treated skin. Thus, IFN-gamma, which is significantly elevated in non-lesional skin compared to healthy skin, appears to be a key pathogenic cytokine that can induce the inflammatory cascade in psoriasis. RNA was isolated from whole skin punch biopsies of either healthy or non-lesional psoraisis patients at baseline or 24 hours after placebo or IFN-g injection.