Project description:Anti-TNF-alpha therapy has made a significant impact on the treatment of psoriasis. Despite being designed to neutralize TNF-alpha activity, the mechanism of action of these agents in the resolution of psoriasis remains unclear. The aim of this study was to better understand the mechanism of action of etanercept by examining very early changes in the lesional skin of psoriasis patients. 20 chronic plaque psoriasis patients were enrolled and received 50mg etanercept twice weekly. Skin biopsies were obtained before treatment and on days 1, 3, 7 and 14 post-treatment. Skin mRNA expression was analysed by microarray.
Project description:Anti-TNF-alpha therapy has made a significant impact on the treatment of psoriasis. Despite being designed to neutralize TNF-alpha activity, the mechanism of action of these agents in the resolution of psoriasis remains unclear. The aim of this study was to better understand the mechanism of action of etanercept by examining very early changes in the lesional skin of psoriasis patients. 20 chronic plaque psoriasis patients were enrolled and received 50mg etanercept twice weekly. Skin biopsies were obtained before treatment and on days 1, 3, 7 and 14 post-treatment. Skin mRNA expression was analysed by microarray. Twenty individuals with chronic plaque psoriasis were enrolled (age range 18-75 years). Entry criteria included age greater than 18 years and stable plaque-type psoriasis involving at least 10% body surface area. Exclusion criteria included use of systemic psoriasis therapy within 4 weeks, topical therapy within 2 weeks, or severe co-morbid diseases. For 12 weeks, subjects received etanercept (Enbrel) 50mg twice a week subcutaneously. At baseline, 6 mm punch biopsies were obtained under local anaesthesia (lidocaine) from uninvolved skin and a target plaque. Subsequent biopsies were taken on days 1, 3, 7 and 14 of therapy from the same target plaque.
Project description: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 emigre-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. Experiment Overall Design: In this study 15 patients with moderate-to-severe psoriasis were given 50mg of etanercept (Amgen) biweekly for 12 weeks. And analyzed using gene array on mRNA extracted from tissue collected at each biopsy time point (non-lesional Time: 0; lesional Time: 0, weeks 1, 2, 4, and 12). Patients were stratified as 'responders' or 'non-responders' based on whether or not they achieved histologic disease resolution by week 12 of etanercept treatment (decreased epidermal thickening, normalization of proliferation marker Ki67, and loss of differentiation marker K16).
Project description: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 émigré-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. Keywords: time-course experiment
Project description:Blood (mRNA and miRNA) and skin mRNA transcriptomes were investigated across three time-points in a pilot investigation of ten severe psoriasis patients, treated with the tumor necrosis factor (TNF) inhibitor, etanercept. We used illumina RNA-sequencing to analyse the small-RNA transcriptome in blood
Project description:Blood (mRNA and miRNA) and skin mRNA transcriptomes were investigated across three time-points in a pilot investigation of ten severe psoriasis patients, treated with the tumor necrosis factor (TNF) inhibitor, etanercept. We used illumina RNA-sequencing to analyse the small-RNA transcriptome in blood
Project description:Blood (mRNA and miRNA) and skin mRNA transcriptomes were investigated across three time-points in a pilot investigation of ten severe psoriasis patients, treated with the tumor necrosis factor (TNF) inhibitor, etanercept. We used illumina RNA-sequencing to analyse the mRNA transcriptome in blood
Project description:Our group recently described a population of antigen presenting cells that appear to be critical in psoriasis pathogenesis, termed inflammatory myeloid dendritic cells (CD11c+ BDCA1-). Triggering receptor expressed on myeloid cells type-1 (TREM-1) signaling was a major canonical pathway in the published transcriptome of these cells. TREM-1 is a member of the immunoglobulin superfamily, active through the DAP12 signaling pathway, with an unknown ligand. Activation through TREM-1 induces inflammatory cytokines including IL-8, MCP/CCL2 and TNF. We now show that TREM-1 was expressed in the skin of healthy and psoriatic patients, and there was increased soluble TREM-1 in the circulation of psoriasis patients. In psoriasis lesions, TREM-1 was co-localized with dendritic cells as well as CD31+ endothelial cells. TREM-1 expression was reduced with successful NB-UVB, etanercept and anti-IL-17 treatments. An in vitro model of PGN-activated monocytes as inflammatory myeloid DCs was developed to study TREM-1 blockade, and treatment with a TREM-1 blocking chimera decreased allogeneic Th17 activation, as well as IL-17 production. Furthermore, TREM-1 blockade of ex vivo psoriatic dendritic cells in an alloMLR also showed a decrease in IL-17. Together, these data suggest that the TREM-1 signaling pathway offers a novel therapeutic target to prevent the effects of inflammatory myeloid DCs in psoriasis. Monocytes were isolated by plastic adherence, treated with TLR agonists overnight, washed twice and harvested in RTL-buffer. RNA was extracted and processed for microarray. 3 groups and 3 replicates with a paired structure across replicates
Project description:A gene expression profiling sub-study was conducted in which skin biopsy samples (n=192) were collected for RNA extraction and hybridization to microarrays from patients with moderate-to-severe psoriasis who participated in ACCEPT, an IRB-approved Phase 3, multicenter, randomized trial. This analysis identified gene expressions significantly modulated in psoriasis lesions (LS) following ustekinumab or etanercept treatment at week 12 compared to baseline. Molecular expression of mRNA was found to be different in ustekinumab PASI75 responders vs. nonresponders. Differential modulation of selected mRNAs was also observed between ustekinumab and etanercept PASI75 responders.