Project description:Glioma cells are sensitized to the alkylator temozolomide after exposure to IFN-beta. In glioma-initiating cells (GIC), IFN-beta alone reduces clonogenicity. We investigated differentially expressed genes with or without IFN exposure in either longterm glioma cells or GIC. We used microarrays to investigate differential gene regulation in glioma cells after exposure to either ddH20 or IFN-beta 300 IU/ml at 6 h or 24 h. We used either the longterm cell line LNT-229 or the GIC cell lines GS-2 and GS-9 and exposed them to either IFN-beta 300 IU/ml or ddH20 for 6 h or 24 h.
Project description:Glioma cells are sensitized to the alkylator temozolomide after exposure to IFN-beta. In glioma-initiating cells (GIC), IFN-beta alone reduces clonogenicity. We investigated differentially expressed genes with or without IFN exposure in either longterm glioma cells or GIC. We used microarrays to investigate differential gene regulation in glioma cells after exposure to either ddH20 or IFN-beta 300 IU/ml at 6 h or 24 h.
Project description:Gene expression profiling of immortalized human mesenchymal stem cells with hTERT/E6/E7 transfected MSCs. hTERT may change gene expression in MSCs. Goal was to determine the gene expressions of immortalized MSCs.
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.
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 controlled release of mitochondrial content has emerged as a key step in mitochondrial signaling. Particularly the release of mitochondrial DNA (mtDNA) into the cytosol has been shown to activate interferon beta (IFN-β) gene expression to execute the innate immune response. In this report, we show that human adenovirus type 5 (HAdV-C5) induces the release of mtDNA in infected cells. The release of mtDNA is mediated by the viral internal minor capsid protein pVI, which localizes into mitochondria and undergoes mitochondria-specific proteolytic processing. The membrane lytic activity of the pVI and the presence of the mitochondrial membrane proteins Bak and Bax are needed for the mtDNA release. Surprisingly, the pVI-mediate mtDNA release did not increase but blocked IFN-β gene expression. This inhibition was due to the concurrent leakage of the mitochondrial chaperon protein HSP60, which by inhibiting phosphorylation of the interferon regulatory factor 3 (IRF3), blocked IFN-β gene expression. Collectively, our study suggests that the complex release of mtDNA and mitochondrial proteins modulate the IFN-β signaling cascade during pathogenic HAdV-C5 infection.