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:Transcriptional profiling of human mesenchymal stem cells comparing normoxic MSCs cells with hypoxic MSCs cells. Hypoxia may inhibit senescence of MSCs during expansion. Goal was to determine the effects of hypoxia on global MSCs gene expression. Two-condition experiment, Normoxic MSCs vs. Hypoxic MSCs.
Project description:Background: Bone marrow-derived multipotent progenitor cell (MPC) transplantation leads to short term functional and bioenergetic improvement in a porcine model of postinfarction Left Ventricular (LV) remodeling despite a low engraftment rate. However, the long term outcome after MPC transplantation is unknown. Methods and Results: The objectives of this study were to determine the long term functional outcome after MPC transplantation in a porcine model of postinfarction LV remodeling and to elucidate its mechanisms. Myocardial infarction (MI) was created by ligating the first and second diagonal branches of the Left anterior descending artery after open thoracotomy. Intramyocardial injection of 50 million lacZ labeled MPC was performed in the periscar region (Cell, n=7) with 5 equal injections immediately after MI, while in control animals (CONT, n=7; only 6 were profiled by microarray) saline was injected. Outcome was assessed temporally for 4 months with MRI and P-31 MRS. Engraftment was studied on histology and gene chip (Affymetrix) array analysis was used to study differential expression of genes in the two groups at 4 months. MPC treatment resulted in improvement of ejection fraction as early as 10 days after MI (32.2±5.5 vs. 43.4±5.1 in CONT and Cell respectively, p <0.05). This improvement was seen each month and persisted up to 4 months (35.7±5.0 vs. 51.2±4.8 in CONT and Cell respectively, p<0.005). PCr/ATP ratio improved with MPC transplantation (1.88±0.11 vs. 2.13±0.13 in CONT and Cell respectively, p<0.05). Under increased workload with inotropic stimulation, the bioenergetic differences were even more pronounced. There was no significant difference in scar size (scar/LV area*100) at 10 days post infarction (9.7±2.3 vs. 8.3±1.5 in CONT and Cell respectively). However, at 4 months there was a significant decrease in scar size in the MPC treated animals (8.6±2.4 vs. 4.6±1.0 in CONT and Cell respectively, p <0.05). No significant engraftment of MPC was observed on histology at 4 months. Gene chip array analysis identified several genes which were differentially expressed in the two groups. MPC transplantation was associated with a downregulation of mitochondrial oxidative enzymes, increased levels of MEF2a (Myocyte Enhancer Factor 2a) and ZFP91 (Zinc finger protein 91). Conclusion: MPC transplantation results in long term improvement in ventricular function and myocardial energetics that is associated with a decreased scar size and differential expression of genes.
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:To assess RNA regulation in FALS for gene expression and alternative processing of RNA in the motor neuron precurssors (MPCs) Amyotrophic lateral sclerosis (ALS) is a late-onset motor neuron disorder. Although its neuropathology is well understood, the cellular and molecular mechanisms that lead to the initiation and progression of this disease are yet to be elucidated due to limitations in the currently available human genetic data. In this study, we generated induced pluripotent stem cells (iPSC) from two familial ALS (FALS) patients with a missense mutation in the fused-in sarcoma (FUS) gene carrying the heterozygous FUS H517D mutation, and the isogenic iPSCs with the homozygous FUS H517D mutation obtained by genome editing from the healthy control iPSCs. These cell-derived motor neurons mimicked several neurodegenerative phenotypes. A part of the mutant FUS protein was localized outside the nucleus and co-localized with stress granules under stress conditions. Moreover, FALS motor neurons showed more apoptotic activity than did control motor neurons. Exon array analysis using motor neuron precursor cells (MPCs) combined with CLIP-seq data sets revealed aberrant gene expression and/or splicing pattern in FALS-MPCs. These results suggest that iPSC-derived motor neurons are a useful tool for analyzing the pathogenesis of human motor neuron disorders.
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
Project description:Gene methylation profiling of immortalized human mesenchymal stem cells comparing HPV E6/E7-transfected MSCs cells with human telomerase reverse transcriptase (hTERT)- and HPV E6/E7-transfected MSCs. hTERT may increase gene methylation in MSCs. Goal was to determine the effects of different transfected genes on global gene methylation in MSCs. Two-condition experiment, KP MSCs vs. 3A6 MSCs.