Project description:Neuron-restrictive silencer factor (NRSF) and its isoforms are differentially regulated in rodent models of self-sustaining status epilepticus (SSSE). NRSF isoforms regulate genes associated with SSSE, including the proconvulsant tachykinins, brain-derived neurotrophic factor and multiple ion channels. NRSF isoforms may direct distinct gene expression patterns during SSSE and the ratio of each isoform may be a causative factor in traumatic damage to the CNS. Here we analysed global gene expression changes by microarray in human SK-N-AS neuroblastoma cells following the over expression of NRSF and a truncated isoform, HZ4. We used bioinformatics software to analyse the microarray dataset and correlated these data with epilepsy candidate gene pathways. Findings were validated by RT-PCR. We demonstrated that NRSF and HZ4 direct overlapping as well as distinct gene expression patterns and that they differentially modulated gene expression patterns associated with epilepsy. Finally we revealed that NRSF gene expression may be modulated by the anticonvulsant, phenytoin. This study provides fundamental information on networks of genes that may be altered during SSSE, following altered NRSF expression, which may be important in future therapeutic research and clinical analysis of genetic variation predisposing to epilepsy. Human SK-N-AS cells were treated with expression constructs over-expressing either the full length human transcription factor, NRSF, (via the RE-EX1 construct) or a truncated variant (via the HZ4 construct). Cells were treated for either 0hrs (base line controls), 24hrs or 48hrs, before being immediately processed for RNA extraction. An affymetrix microarray was employed to investigate gene expression patterns, comparing each time point (24hrs or 48hrs) againsts its baseline ()hrs) control. This experiment was performed in triplicate samples per batch, and over three batches.
Project description:Neuron-restrictive silencer factor (NRSF) and its isoforms are differentially regulated in rodent models of self-sustaining status epilepticus (SSSE). NRSF isoforms regulate genes associated with SSSE, including the proconvulsant tachykinins, brain-derived neurotrophic factor and multiple ion channels. NRSF isoforms may direct distinct gene expression patterns during SSSE and the ratio of each isoform may be a causative factor in traumatic damage to the CNS. Here we analysed global gene expression changes by microarray in human SK-N-AS neuroblastoma cells following the over expression of NRSF and a truncated isoform, HZ4. We used bioinformatics software to analyse the microarray dataset and correlated these data with epilepsy candidate gene pathways. Findings were validated by RT-PCR. We demonstrated that NRSF and HZ4 direct overlapping as well as distinct gene expression patterns and that they differentially modulated gene expression patterns associated with epilepsy. Finally we revealed that NRSF gene expression may be modulated by the anticonvulsant, phenytoin. This study provides fundamental information on networks of genes that may be altered during SSSE, following altered NRSF expression, which may be important in future therapeutic research and clinical analysis of genetic variation predisposing to epilepsy.
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: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.
Project description:Neuroblastoma is a solid pediatric tumor with heterogeneous clinical behaviors. Chemotherapy is widely used to treat neuroblastoma. However, dose-dependent responses and chemoresistance mechanisms of neuroblastoma cells to anticancer drugs remain challenges in various conditions. Here, we investigated the dose-dependent effects of topotecan on human neuroblastoma cells (SK-N-SH, SH-SY5Y, and SK-N-BE) under various nutrient supply conditions. Serum-starved human neuroblastoma cells showed reduced toxicity, and their survival rate increased upon treatment with a high concentration (1 μM) of topotecan. Quantitative profiling of global and phosphoproteome identified 12,959 proteins and 48,812 phosphosites, respectively, from SK-N-SH cells. Network analysis revealed that topotecan up-regulated DNA repair and cholesterol-mediated topotecan efflux, resulting in topotecan resistance. Results of DNA damage assay, cell cycle, and quantitative analyses of membrane cholesterol supported the validity of these resistance factors and their applicability to all neuroblastoma cells investigated in this study. Our results provide a model for high dose-dependent chemoresistance in neuroblastoma cells that could enable a patient-dependent chemotherapy screening strategy.
Project description:Aim: to detect genes that are differentially transcribed in neuronal cells(SK-N-SH) over-expressing either of the two MECP2 isoforms, MECP2_e1 or MECP2_e2. Methods: the human neuroblastoma cell line SK-N-SH was stably infected by lentiviral vectors over-expressing MECP2_e1, MECP2_e2, or eGFP, and were then differentiated into neurons. RNA extracted, and used for gene expression microarray analysis
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. One-condition experment, gene expression of 3A6
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.