Project description:LncRNAs are key regulatory molecules involved in a variety of biological process and human diseases. However, the pathological effects of lncRNAs on primary varicose great saphenous veins (GSVs) remain unclear. In this study, we aimed at identifying aberrantly expressed lncRNAs involved in the prevalence of GSV varicosities and exploring their potential regulating effects. 6 paired tissues of the varicose great saphenous vein patient were used to compare the expression differences between varicose veins (VVs) and adjacent normal segments of saphenous veins (NVs) in the study. The lncRNA and mRNA expression profile of 6 paired vein tissues were studied using the microarry.
Project description:LncRNAs are key regulatory molecules involved in a variety of biological process and human diseases. However, the pathological effects of lncRNAs on primary varicose great saphenous veins (GSVs) remain unclear. In this study, we aimed at identifying aberrantly expressed lncRNAs involved in the prevalence of GSV varicosities and exploring their potential regulating effects.
Project description:To understand the consequences of venous hypertension, normal and varicose veins were evaluated using proteomics approaches targeting the extracellular matrix.
Project description:To identify genes involved in the formation of a pathological phenotype of varicose veins, we attempted to analyze the methylome of their constituent cells and compare it to the methylome of normal veins from the same patient. We identified a number of genes of extracellular matrix remodeling and cell-cell communication whose methylation status was significantly changed in disease condition.
Project description:To identify genes whose products are involved in the formation of a pathological phenotype of varicose veins, we attempted to analyze the transcriptome of their constituent cells and compare it to the transcriptome of normal veins from the same patient. We identified a number of genes of extracellular matrix remodeling and cell-cell communication significantly changing gene expression status in disease condition.
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: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:BACKGROUND: As evidenced by epidemiological and etiological studies, the development of varicose veins is driven by risk-factors which support the development of venous hypertension and thus chronically augment circumferential stress of the venous wall (e.g. dysfunctional venous valves, pregnancy or obesity). We have previously verified the relevance of this biomechanical stimulus for the activation of venous endothelial as well as smooth muscle cells and the subsequent detrimental structural remodeling of the vein wall in experimental mouse models. METHODS: Here, transcriptome analyses revealed an increase in the expression of cyclooxygenase 2 (COX-2) in human venous endothelial cells upon exposure to biomechanical stress. Subsequently, we investigated the impact of diclofenac – a cyclooxygenase inhibitor – on responses of isolated mouse veins to augmented wall stress in vitro and on varicose-like venous remodeling in vivo. RESULTS: Diclofenac treatment decreased COX-2 protein abundance in mouse veins but had no significant impact on the expression of corresponding transcripts. Short-term exposure to elevated pressure levels stimulated the activity of matrix-metalloproteinase-2 (MMP-2) and mitogen activated protein kinases ERK1/2. Diclofenac decreased the level of activated MMP-2 and ERK1/2 in pressure-exposed mouse veins. Varikose-like remodeling of veins in the mouse auricle was significantly inhibited by transdermal application of diclofenac-containing phospholipid-micelles. This effect was associated with decreased COX-2 and MMP-2 abundance as well as cell proliferation. CONCLUSION: The cyclooxygenase inhibitor diclofenac interferes with short term activation of MAP-kinases and matrix-metalloproteinases in cells of the wall stress-exposed venous wall while attenuating venous remodeling in vivo. Thus, nonsteroidal anti-inflammatory drugs may be suitable to interfere with processes promoting the progression of varicose vein development and biomechanical activation of venous cells.