Project description:Transcriptional profiling of Homo sapiens inflammatory skin diseases (whole skin biospies): Psoriasis (Pso), vs Atopic Dermatitis (AD) vs Lichen planus (Li), vs Contact Eczema (KE), vs Healthy control (KO) In recent years, different genes and proteins have been highlighted as potential biomarkers for psoriasis, one of the most common inflammatory skin diseases worldwide. However, most of these markers are not psoriasis-specific but also found in other inflammatory disorders. We performed an unsupervised cluster analysis of gene expression profiles in 150 psoriasis patients and other inflammatory skin diseases (atopic dermatitis, lichen planus, contact eczema, and healthy controls). We identified a cluster of IL-17/TNFα-associated genes specifically expressed in psoriasis, among which IL-36γ was the most outstanding marker. In subsequent immunohistological analyses IL-36γ was confirmed to be expressed in psoriasis lesions only. IL-36γ peripheral blood serum levels were found to be closely associated with disease activity, and they decreased after anti-TNFα-treatment. Furthermore, IL-36γ immunohistochemistry was found to be a helpful marker in the histological differential diagnosis between psoriasis and eczema in diagnostically challenging cases. These features highlight IL-36γ as a valuable biomarker in psoriasis patients, both for diagnostic purposes and measurement of disease activity during the clinical course. Furthermore, IL-36γ might also provide a future drug target, due to its potential amplifier role in TNFα- and IL-17 pathways in psoriatic skin inflammation. In recent years, different genes and proteins have been highlighted as potential biomarkers for psoriasis, one of the most common inflammatory skin diseases worldwide. However, most of these markers are not psoriasis-specific but also found in other inflammatory disorders. We performed an unsupervised cluster analysis of gene expression profiles in 150 psoriasis patients and other inflammatory skin diseases (atopic dermatitis, lichen planus, contact eczema, and healthy controls). We identified a cluster of IL-17/TNFα-associated genes specifically expressed in psoriasis, among which IL-36γ was the most outstanding marker. In subsequent immunohistological analyses IL-36γ was confirmed to be expressed in psoriasis lesions only. IL-36γ peripheral blood serum levels were found to be closely associated with disease activity, and they decreased after anti-TNFα-treatment. Furthermore, IL-36γ immunohistochemistry was found to be a helpful marker in the histological differential diagnosis between psoriasis and eczema in diagnostically challenging cases. These features highlight IL-36γ as a valuable biomarker in psoriasis patients, both for diagnostic purposes and measurement of disease activity during the clinical course. Furthermore, IL-36γ might also provide a future drug target, due to its potential amplifier role in TNFα- and IL-17 pathways in psoriatic skin inflammation.
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.
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:Proteomic profiles of 92 inflammatory proteins were measured in the blood of psoriasis patients both before and after treatment with tofacitanib or etanercept. These proteomic profiles were used to develop statistical classifiers for predicting PASI75 responses to tofacitinib and etancercept
Project description:Proteomic profiles of 91 cardiovascular disease proteins were measured in the blood of psoriasis patients both before and after treatment with tofacitanib or etanercept. These proteomic profiles were used to develop statistical classifiers for predicting PASI75 responses to tofacitinib and etancercept
Project description:Kynureninase is a member of a large family of catalytically diverse but structurally homologous pyridoxal 5'-phosphate (PLP) dependent enzymes known as the aspartate aminotransferase superfamily or alpha-family. The Homo sapiens and other eukaryotic constitutive kynureninases preferentially catalyze the hydrolytic cleavage of 3-hydroxy-l-kynurenine to produce 3-hydroxyanthranilate and l-alanine, while l-kynurenine is the substrate of many prokaryotic inducible kynureninases. The human enzyme was cloned with an N-terminal hexahistidine tag, expressed, and purified from a bacterial expression system using Ni metal ion affinity chromatography. Kinetic characterization of the recombinant enzyme reveals classic Michaelis-Menten behavior, with a Km of 28.3 +/- 1.9 microM and a specific activity of 1.75 micromol min-1 mg-1 for 3-hydroxy-dl-kynurenine. Crystals of recombinant kynureninase that diffracted to 2.0 A were obtained, and the atomic structure of the PLP-bound holoenzyme was determined by molecular replacement using the Pseudomonas fluorescens kynureninase structure (PDB entry 1qz9) as the phasing model. A structural superposition with the P. fluorescens kynureninase revealed that these two structures resemble the "open" and "closed" conformations of aspartate aminotransferase. The comparison illustrates the dynamic nature of these proteins' small domains and reveals a role for Arg-434 similar to its role in other AAT alpha-family members. Docking of 3-hydroxy-l-kynurenine into the human kynureninase active site suggests that Asn-333 and His-102 are involved in substrate binding and molecular discrimination between inducible and constitutive kynureninase substrates.
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:We have sequenced miRNA libraries from human embryonic, neural and foetal mesenchymal stem cells. We report that the majority of miRNA genes encode mature isomers that vary in size by one or more bases at the 3’ and/or 5’ end of the miRNA. Northern blotting for individual miRNAs showed that the proportions of isomiRs expressed by a single miRNA gene often differ between cell and tissue types. IsomiRs were readily co-immunoprecipitated with Argonaute proteins in vivo and were active in luciferase assays, indicating that they are functional. Bioinformatics analysis predicts substantial differences in targeting between miRNAs with minor 5’ differences and in support of this we report that a 5’ isomiR-9-1 gained the ability to inhibit the expression of DNMT3B and NCAM2 but lost the ability to inhibit CDH1 in vitro. This result was confirmed by the use of isomiR-specific sponges. Our analysis of the miRGator database indicates that a small percentage of human miRNA genes express isomiRs as the dominant transcript in certain cell types and analysis of miRBase shows that 5’ isomiRs have replaced canonical miRNAs many times during evolution. This strongly indicates that isomiRs are of functional importance and have contributed to the evolution of miRNA genes