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.
Project description:Psoriasis is a chronic, debilitating, immune-mediated inflammatory skin disease. As IFN-γ 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-γ-producing Th1 cells were proposed to be integral to the pathogenesis of psoriasis. Recently, IFN-γ 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-γ indeed induces the pathways leading to the development of psoriasis lesions, a single intradermal injection of IFN-γ 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-γ induced molecular and histological features characteristic of psoriasis lesions. IFN-γ 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-γ-treated skin. Thus, IFN-γ, 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.
Project description:Psoriasis is a systemic disease with cutaneous manifestations. MicroRNAs (miRNAs) are non-coding RNA molecules that are differentially expressed in psoriatic skin, however; only few miRNAs have been localized to specific cells or regions of psoriatic lesions. We used laser capture microdissection (LCM) and next-generation sequencing to study the specific miRNA expression profiles in the epidermis (Epi) and dermal inflammatory aggregates (RD/ICs) of psoriatic skin. We identified 24 deregulated miRNAs in the Epi and 37 deregulated miRNAs in the RD/ICs of lesional psoriatic skin compared with non-lesional psoriatic skin (FCH>2, FDR<0.05). Interestingly, 9 of the 37 miRNAs, including miR-193b and miR-223 that have recently been described as deregulated in circulating peripheral blood mononuclear cells (PBMCs) from patients with psoriasis. Using flow cytometry and qRT-PCR, miR-193b and miR-223 were found to be expressed in Th17 cells. In conclusion, we demonstrate that LCM combined with small RNA sequencing provides a robust strategy to explore the global miRNA expression in the epidermal and dermal compartments of psoriatic skin. Furthermore, our results indicate that the altered local miRNA changes seen in the RD/ICs is reflected in the circulating immune cells, altogether emphasizing that miRNAs may contribute to a systemic component in the pathogenesis of psoriasis. Examination of the global miRNA expression in epidermis (Epi) and dermis (RD/ICs) of paired (non-lesional vs. lesional) psoriatic skin using a combination of laser-capture microdissection and barcoded small RNA sequencing
Project description:To explore the psoriasis phenotype, we characterize gene expression in lesional and non-lesional skin from psoriasis patients. We extracted total RNA from 5mm punch biopsies taken from 14 psoriatic patients. From each patient, we obtained two biopsies, one from a lesion and the other from non-lesional skin in the same general body geography. A total of 28 samples were run on Affymetrix HU133 Plus 2.0 microarrays.
Project description:Background: Plaque psoriasis is a chronic autoimmune disorder characterized by the development of red scaly plaques. To date psoriasis lesional skin transcriptome has been extensively studied, whereas only few proteomic studies of psoriatic skin are available. Aim: The aim of this study was to compare protein expression patterns of lesional and normally looking skin of psoriasis patients with skin of the healthy volunteers, reveal differentially expressed proteins and identify changes in cell metabolism caused by the disease. Methods: Skin samples of normally looking and lesional skin donated by psoriasis patients (n = 5) and samples of healthy skin donated by volunteers (n = 5) were analyzed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). After protein identification and data processing, the set of differentially expressed proteins was subjected to protein ontology analysis to characterize changes in biological processes, cell components and molecular functions in the patients' skin compared to skin of the healthy volunteers. Results: The performed analysis identified 405 and 59 differentially expressed proteins in lesional and normally looking psoriatic skin compared to healthy control. We discovered decreased expression of KNG1, APOE, HRG, THBS1 and PLG in normally looking skin of the patients. Presumably, these changes were needed to protect the epidermis from spontaneous activation of kallikrein-kinin system and delay the following development of inflammatory response. In lesional skin, we identified several large groups of proteins with coordinated expression. Mainly, these proteins were involved in different aspects of protein and RNA metabolism, namely ATP synthesis and consumption; intracellular trafficking of membrane-bound vesicles, pre-RNA processing, translation, chaperoning and degradation in proteasomes/immunoproteasomes. Conclusion: Our findings explain the molecular basis of metabolic changes caused by disease in skin lesions, such as faster cell turnover and higher metabolic rate. They also indicate on downregulation of kallikrein-kinin system in normally looking skin of the patients that would be needed to delay exacerbation of the disease.
Project description:Background: In present study we performed whole transcriptome analysis in plaque psoriasis patients and compared lesional skin with non-lesional skin and with the skin from healthy controls. We sequenced total RNA from 12 lesional (LP), 12 non-lesional (NLP) and from 12 normal (C) skin biopsies. Results: Compared with previous gene expression profiling studies we had three groups under analysis - LP, NLP and C. Using NLP samples allows to see the transcriptome of visually normal skin from psoriasis patient. In LP skin S100A12, S100A7A, LCE3E, DEFB4A, IL19 were found up regulated. In addition to already well-described genes, we also found several other, not so widely recognized transcripts, related to psoriasis. Namely, KLK9, OAS2, OAS3, PLA2G, IL36G, IL36RN were found to be significantly and consistently related to the psoriatic lesions. Ingenuity pathway analysis was used to define functional networks significantly enriched in the studied samples. The genes up-regulated in the LP samples were related to the innate immunity, IL17 and IL10 networks. In NLP samples innate immunity and IL17 network were activated, but activation of IL10 network was not evident. The transcriptional changes characteristic in the NLP samples can be considered as a molecular signature of “dormant psoriasis”. Conclusions: Taken together, our study described the transcriptome profile characteristic for LP and NLP psoriatic skin. RNA profile of the NLP skin is in between the lesional and healthy skin, with its own specific pattern. We found that both LP and NLP have up-regulated IL17 network, whereas LP skin has up regulated IL10 related cytokines (IL19, IL20, IL24). Moreover, IL36G and IL36RN were identified as strong regulators of skin pathology in both LP and NLP skin samples, with stronger influence in LP samples. 36 samples, 24 from psoriasis and 12 from controls
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:Background and Aims: Chronic plaque psoriasis results from genetic and environmental factors that activate inflammatory pathways involving both innate and adaptive immunity. Although the histological features are well known, protein-level changes—especially with spatial resolution—are less understood. This study aimed to investigate layer-specific proteomic changes in psoriatic skin. Methods: Skin biopsies from psoriasis patients (N=8) and healthy controls (N=8) were separated into four layers (stratum corneum, inner epidermis, dermis, subcutis) using laser-capture microdissection. Proteins were extracted and analyzed by mass spectrometry. Results: We identified 7,236 proteins, with 1,649 differentially expressed in lesional vs. non-lesional inner epidermis. Upregulated proteins were linked to innate immunity, cholesterol synthesis and tissue structure. The stratum corneum in lesions showed more complex protein profiles than in controls. The dermis displayed increased proteins related to IL-17 signaling and neutrophil recruitment. No significant changes were found in the subcutis. Conclusion: This dataset highlights the inner epidermis as a key site of proteomic alterations in psoriasis, driven by proteins related to immune activity, tissue structure and cholesterol synthesis. The layer-specific approach offers detailed spatial insights into disease-associated protein changes.
Project description:To investigate the early host response triggered by three different strains of Trypanosoma cruzi at a local infection site, changes in host gene expression were monitored in a murine intradermal infection model using Affymetrix oligonucleotide arrays. Robust induction of IFN-stimulated genes (ISGs) was observed in excised skin 24 hours post-infection where the level of ISG induction was parasite strain-dependent with the least virulent strain triggering a muted IFN response. Infection of mice immunodepleted of IFNγ-producing cells or infection of IFNγ-deficient mice had minimal impact on the IFN response generated in T. cruzi infected mice. In contrast, infection of mice lacking the type I IFN receptor demonstrated that type I IFNs are largely responsible for the IFN response generated at the site of infection. These data highlight type I IFNs as important components of the innate immune response to T. cruzi the site of inoculation and their role in shaping the early transcriptional response to this pathogen. We used microarrays to detail the local host transcriptional response to intradermal T. cruzi infection in WT mice and mice depleted of NK cells, or deficient in IFN-gamma or type I IFN responses. Additionally we compared the local host-transcriptional response generated to infection with 3 different strains of Trypanosoma cruzi (Y, Brazil, and G). Experiment Overall Design: Mice were infected by intradermal injection of 10^6 T. cruzi trypomastigotes in 100uL of saline split between 2 adjacent sites on the shaved side flank. Control mice were injected with an equal volume of saline. 24 hours post-injection approximately 75mm^2 of skin immediately surrounding the injection site was excised and RNA was isolated from the tissue. Balb/c mice were used for most experiments and IFN-gamma KO mice were on the Balb/c background. WT 129 mice were also used as IFNAR-/- mice were on the 129 background. In total 33 arrays were performed. 7 WT (Balb/c) control, 3 Y strain infected, 3 Brazil strain infected, 3 G strain infected, 2 IFN-gamma KO control, 2 IFN-gamma KO infected, 1 NK cell depleted control, 1 NK cell depleted infected, 3 WT (129) control, 3 WT (129) infected, 3 IFNAR KO control, 3 IFNAR KO infected