The transcriptomic profiling of psoriasis has led to an increased understanding of disease pathogenesis. Although microarray technologies have been instrumental in this regard, it is clear that these tools detect an incomplete set of DEGs. RNA-seq can be used to supplement these prior technologies. Here, the use of RNAseq methods substantially increased the number of psoriasis-related DEGs. Furthermore, DEGs that were uniquely identified by RNA-seq, but not in other published microarray studies, further supported the role of IL-17 and tumor necrosis factor-a synergy in psoriasis. Examination of one of these factors at the protein level confirmed that RNA-seq is a powerful tool that can be used to identify molecular factors present in psoriasis lesions, and may be useful in the identification of therapeutic targets that to our knowledge have not been reported previously. Further studies are in progress to determine the biological significance of DEGs uniquely discovered by RNA-seq. Overall design: To define the transcriptomic profile of psoriatic skin, three pairs of lesional and nonlesional skin biopsy specimens were taken from patients with untreated moderate-to-severe plaque psoriasis.
Transcriptional profiling of psoriasis using RNA-seq reveals previously unidentified differentially expressed genes.
Specimen part, Subject
View SamplesA gene expression profiling sub-study was conducted in which skin biopsy samples were collected from 85 patients with moderate-to-severe psoriasis who were participating in ACCEPT, an IRB-approved Phase 3, multicenter, randomized trial. This analysis identified 4,175 probe-sets as being significantly modulated in psoriasis lesions (LS) compared with matched biopsies of non-lesional (NL) skin.
Expanding the psoriasis disease profile: interrogation of the skin and serum of patients with moderate-to-severe psoriasis.
Specimen part, Disease, Disease stage, Subject
View SamplesThe sensation of hunger after a period of fasting and the sensation of satiety after eating is crucial to behavioral regulation of food intake, but the biological mechanisms regulating these sensations are incompletely understood. We studied the behavioral and physiological adaptation to fasting in the vinegar fly (Drosophila melanogaster). Here we show that flies demonstrated increased behavioral attraction to food odor when food-deprived with no corresponding increase in sensitivity in the peripheral olfactory system. Flies increased their food intake transiently in the post-fasted state, but returned to a stable baseline feeding level within 24 hr after return to food. This modulation in feeding was accompanied by a significant increase in the size of the crop organ of the digestive system, suggesting that fasted flies responded both by increasing their food intake and storing reserve food in their crop. The post-fasting feeding response was observed in both male and female flies of diverse genetic backgrounds. Expression profiling of head, body, and chemosensory tissues by microarray analysis revealed several hundred genes that are regulated by feeding state, including 247 genes in the fly head. We performed RNA interference-mediated knockdown of, takeout, one of the genes strongly downregulated by fasting in multiple tissues. When takeout was knocked down in all neurons the post-fasting feeding response was abolished. These observations suggest that a coordinated transcriptional response to internal physiological state may regulate both ingestive behaviors and chemosensory perception of food
Post-fasting olfactory, transcriptional, and feeding responses in Drosophila.
Specimen part, Treatment, Time
View SamplesAlefacept treatment is highly effective in a select group patients with moderate-to-severe psoriasis, and is an ideal candidate to develop systems to predict who will respond to therapy. A clinical trial of 22 patients with moderate to severe psoriasis treated with alefacept (7.5mg weekly i.v. x12 weeks) was conducted in 2002-2003, as a mechanism of action study. Patients were classified as responders or non-responders to alefacept based on histological criteria. Microarray data from PBMCs of 16 of these patients was analyzed to generate a treatment response classifier. We used a discriminant analysis method that performs sample classification from gene expression data, via nearest shrunken centroid method''. A disease response classifier using 23 genes was created to accurately predict response to alefacept (12.3% error rate in favour of responders). This preliminary study may provide a useful tool to predict response of psoriatic patients with alefacept.
Personalized medicine in psoriasis: developing a genomic classifier to predict histological response to Alefacept.
Sex, Age, Specimen part, Subject
View SamplesThere is a controversy surrounding the existence of palmoplantar pustulosis (PPP) and palmoplantar pustular psoriasis (PPPP) as separate clinical entities or as variants of the same clinical entity. We used gene expression microarray to compare gene expression in PPP and PPPP. PPP and PPPP could not be differentiated using gene expression microarray suggesting that they are not distinct clinical entities. Increased expression of GPRIN1, and ADAM23 in keratinocytes suggests that these proteins could be new therapeutic targets for PPP/PPPP.
Based on Molecular Profiling of Gene Expression, Palmoplantar Pustulosis and Palmoplantar Pustular Psoriasis Are Highly Related Diseases that Appear to Be Distinct from Psoriasis Vulgaris.
Specimen part, Disease, Subject
View SamplesScalp 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 stage
View SamplesPsoriasis is a complex inflammatory disease resulting from the activation of T helper (Th) 1 and Th17 cells. Recent evidence suggests that abnormal activation of Toll-like receptors (TLRs) 7, 8 and 9 contributes to the initiation and maintenance of psoriasis. We have evaluated the effects of TLR antagonists on the gene expression profile in an IL-23-induced skin inflammation model in mice. Psoriasis-like skin lesions were induced in C57BL/6 mice by intradermal injection of IL-23 in the dorsum. Two TLR antagonists were compared: IMO-3100, an antagonist of TLRs 7 and 9, and IMO-8400, an antagonist of TLRs 7, 8 and 9, both of which previously have been shown to reduce epidermal hyperplasia in this model. Skin gene expression profiles of IL-23-induced inflammation were compared with or without TLR antagonist treatment. IL-23 injection resulted in alteration of 5100 gene probes (fold change 2, FDR < 0.05) including IL-17 pathways that are up-regulated in psoriasis vulgaris. Targeting TLRs 7, 8 and 9 with IMO-8400 resulted in modulation of more than 2300 mRNAs while targeting TLRs 7 and 9 with IMO-3100 resulted in modulation of more than 1900 mRNAs. Both agents strongly decreased IL-17A expression (>12-fold reduction), normalized IL-17 induced genes such as beta-defensin and CXCL1, and normalized aberrant expression of keratin 16 (indicating epidermal hyperplasia). These results suggest that IL-23-driven inflammation in mouse skin may be dependent on signaling mediated by TLRs 7, 8, and 9 and that these receptors represent novel therapeutic targets in psoriasis vulgaris and other diseases with similar pathophysiology.
Suppression of molecular inflammatory pathways by Toll-like receptor 7, 8, and 9 antagonists in a model of IL-23-induced skin inflammation.
Treatment
View SamplesDiscoid lupus erythematosus (DLE) is the most common skin manifestation of lupus. Despite its high frequency in systemic lupus in addition to cases without extracutaneous manifestations, targeted treatments for DLE are lacking, likely because of a dearth of knowledge of the molecular landscape of DLE skin. Here, we profiled the transcriptome of DLE skin in order to identify signaling pathways and cellular signatures that may be targeted for treatment purposes. Further comparison of the DLE transcriptome with that of psoriasis, a useful reference given our extensive knowledge of molecular pathways in this disease, provided a framework to identify potential therapeutic targets. Although a growing body of data support a role for IL-17 and T helper type 17 (Th17) cells in systemic lupus, we show a relative enrichment of IFN--associated genes without that for IL-17-associated genes in DLE. Extraction of T cells from the skin of DLE patients identified a predominance of IFN--producing Th1 cells and an absence of IL-17-producing Th17 cells, complementing the results from whole-skin transcriptomic analyses. These data therefore support investigations into treatments for DLE that target Th1 cells or the IFN- signaling pathway.
Dominant Th1 and minimal Th17 skewing in discoid lupus revealed by transcriptomic comparison with psoriasis.
Specimen part, Subject
View SamplesThe 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, Time
View SamplesIn this study, we sought to establish the usefulness of LCM on cDNA microarray analysis. We reported that LCM samples improved the sensitivity of detection of differentially expressed genes over conventional bulk tissue analysis. We also provided the new information of chemokine and its receptor interaction within psoriatic lesional skin.
Combined use of laser capture microdissection and cDNA microarray analysis identifies locally expressed disease-related genes in focal regions of psoriasis vulgaris skin lesions.
Specimen part, Subject
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