Project description:Understanding the crosstalk between malignant B-cells and their milieu could provide clues on the molecular and clinical biology of Chronic Lymphocytic Leukemia (CLL). Aiming to generate novel therapeutic strategies, different groups have studied different CLL proliferative fractions. We previously, identified one of these proliferative subsets in the peripheral blood from progressive unmutated CLL patients. Since the presence of this small subset appears to be a hallmark of a proliferative disease in which B lymphocytes are being constitutively activated in the proliferative centers of these patients, we performed gene expression analysis comparing the global mRNA and microRNAs expression of this leukemic subpopulation. Our results suggest that the proliferative behaviour of this fraction appears to depend on microRNA-22 over-expression, which induces PTEN downregulation and PI3K/AKT pathway activation. Transfection experiments demonstrated that miR-22 overexpression in CLL B-cells switches on PI3K/AKT leading to FOXO1 inactivation, p27-Kip1 downregulation, and overexpression of Survivin and Ki-67 proteins. We also demonstrated that this pathway could be triggered by microenvironment signals like CD40L/IL4 and more importantly, that this regulatory loop is also present in lymph nodes from progressive UM patients. Altogether, these results underline the key role of PI3K/AKT pathway in the generation of the CLL proliferative pool and provide rationale for the usage of PI3K inhibitors. B cells from Chronic Lymphpcytic Leukaemia patients were isolated from blood. By sorting experiments we purify the QF from PF from progressive patients. We extract the total RNA from 8 samples and perform microRNA arrays.
Project description:Understanding the crosstalk between malignant B-cells and their milieu could provide clues on the molecular and clinical biology of Chronic Lymphocytic Leukemia (CLL). Aiming to generate novel therapeutic strategies, different groups have studied different CLL proliferative fractions. We previously, identified one of these proliferative subsets in the peripheral blood from progressive unmutated CLL patients. Since the presence of this small subset appears to be a hallmark of a proliferative disease in which B lymphocytes are being constitutively activated in the proliferative centers of these patients, we performed gene expression analysis comparing the global mRNA and microRNAs expression of this leukemic subpopulation. Our results suggest that the proliferative behaviour of this fraction appears to depend on microRNA-22 over-expression, which induces PTEN downregulation and PI3K/AKT pathway activation. Transfection experiments demonstrated that miR-22 overexpression in CLL B-cells switches on PI3K/AKT leading to FOXO1 inactivation, p27-Kip1 downregulation, and overexpression of Survivin and Ki-67 proteins. We also demonstrated that this pathway could be triggered by microenvironment signals like CD40L/IL4 and more importantly, that this regulatory loop is also present in lymph nodes from progressive UM patients. Altogether, these results underline the key role of PI3K/AKT pathway in the generation of the CLL proliferative pool and provide rationale for the usage of PI3K inhibitors. Two-subset of B cells, QF vs PF. 8 samples of 4 patients.
Project description:Numerous studies have shown that resistance to oxidative stress is crucial to stay healthy and to reduce the adverse effects of aging. Accordingly, nutritional interventions using antioxidant food-grade compounds or food products are currently an interesting option to help improve health and quality of life in the elderly. Live lactic acid bacteria (LAB) administered in food, such as probiotics, may be good antioxidant candidates. Nevertheless, information about LAB-induced oxidative stress protection is scarce. To identify and characterize new potential antioxidant probiotic strains, we have developed a new functional screening method using the nematode Caenorhabditis elegans as host. C. elegans were fed on different LAB strains (78 in total) and nematode viability was assessed after oxidative stress (3mM and 5mM H2O2). One strain, identified as Lactobacillus rhamnosus CNCM I-3690, protected worms by increasing their viability by 30% and, also, increased average worm lifespan by 20%. We performed a transcriptomic analysis of C. elegans fed with this strain and showed that increased lifespan is correlated with differential expression of the DAF-16/insulin-like pathway, which is highly conserved in humans. Gene expression in C. elegans wild-type strain (N2) was analyzed in worm populations fed with E. coli OP50 (control condition) or the corresponding LAB (Lactobacillus rhamnosus CNCM I-3690 or Lactobacillus rhamnosus CNCM I-4317) . Three days and ten days feeding period was analyzed.
Project description:Metabolic engineering of Saccharomyces cerevisiae for efficient monoterpenes production was mostly restricted by the limited tolerance to these chemicals. Understanding of the molecular mechanisms underlying the tolerance of S. cerevisiae to monoterpenes was essential for the de novo biosynthesis these chemicals in S. cerevisiae. In this study, commercial oligonucleotide microarray assays were performed to investigate the global response of S. cerevisiae to typical monoterpene D-limonene under transcriptional level. Yeast cell treated with sublethal dose of D-liomonene, gene change profiles were investigated at transcription level and the microarry data were also verified with quantitative real time PCR. D-limonene induced gene expression in Saccharomyces cerevisiae at early logarithmic phase was measured at 2 hours after exposure to doses of 0.02% (v/v) D-limonene. Three independent experiments were performed for each experiment (control or 2 hours).
Project description:Menin, the product of the MEN1 gene in humans (Men1 in mice), is responsible for the inherited tumor syndrome, multiple endocrine neoplasia type 1 (MEN1). menin interacts with the trithorax group (trxG) proteins (Drosophila) and the mixed-lineage leukemia (MLL) (humans) histone methyltransferase (HMTase) complex, and it alters histone tail modifications and the transcription of target genes. To explore a potential functional implication of menin in HCC, we stably transfected HepG2 or L-02 cells with either vectors or constructs expressing MEN1. A cDNA microarray analysis was performed on HepG2 or L-02 cells with either vectors or constructs expressing MEN1. To obtain a broader understanding of the molecular network of menin in HCC, the whole genome microarray expression profiling was performed on HepG2 or L-02 cells with either vectors or constructs expressing MEN1. Comparison of gene expression results from HepG2 or L-02 cells with either vectors or constructs expressing MEN1.
Project description:To assess for the potential contribution of dysregulated long non-coding RNA expression in autism pathogenesis, we profiled lncRNAs and mRNAs from post mortem brain tissue from autism patients and age/sex matched controls 4 brain tissue samples from autism patients (2 patients, 1 prefrontal cortex and cerebellum sample from each) were compared to 4 brain tissue samples from non-affected controls (2 patients, 1 prefrontal cortex and cerebellum sample from each)
Project description:This SuperSeries is composed of the following subset Series: GSE37678: cDNA Microarray 1: Compression Xylem vs. Opposite Xylem GSE37736: cDNA Microarray 2: Compression Xylem vs. Opposite Xylem Refer to individual Series
Project description:For around ten years, microarrays have been suggested for the diagnosis of ionizing radiation exposure. We assessed for the first time the relevance of gene expression profiling in a real accidental case. This study was performed on peripheral blood mononuclear cells of 41 potential victims. The different strategies of analysis highlighted a huge effect of the blood sample handling on the gene expression profiles. This effect was so high that it could mask specific modulations as a potential effect of ionizing radiation exposure. Thus, we assessed a new way of blood sampling adapted to gene expression analysis: PAXgene. With this method, more than 70% of the modulations of gene expression induced 3 hours after an ex vivo exposure to 0.5 Gy were preserved even in a 24-hour delayed analysis (as for transportation of blood sample from the accident location to the laboratory). We validated a new methodology in order to propose a new strategy of blood sampling and handling for gene profiling. This system could be used in case of accidental overexposure to study whether gene expression is a relevant biomarker of ionizing radiation exposure. Radiation induced gene expression in human blood was measured at 3 hours after exposure to doses of 0 and 0.5 grays. Following the incubation of 3 hours at 37°C, the RNA extractions were performed either immediately or 24h later (as for transportation of blood sample at room temperature). Two different blood preservation methods were compared: classical anticoagulant and PAXgene Blood RNA System. Venous blood samples of 6 donors were used (3 for anticoagulant study, 3 for Paxgene study). Each sample was hybridized twice.
Project description:We conducted microarray analysis to study comprehensive changes of gene expression profile under long-term low-temperature (LT) treatment and to identify other LT-responsive genes related with cold acclimation in seedling leaves and crown tissues (shoots containing apical meristems) of a synthetic hexaploid wheat line. The microarray analysis revealed marked up-regulation of a number of Cor/Lea genes and fructan biosynthesis-related genes under the long-term LT treatment. For validation of the microarray data, we selected four synthetic wheat lines, which contained the A and B genomes from a tetraploid wheat cultivar Langdon and the diverse D genomes originating from the different Ae. tauschii accessions, with distinct levels of freezing tolerance after cold acclimation. Quantitative RT-PCR analyses showed that the transcription accumulated levels of the Cor/Lea, CBF, and fructan biosynthesis-related genes were higher in more freezing-tolerant lines than those in the sensitive lines. The fructan biosynthesis pathway would be associated with cold acclimation to develop wheat freezing tolerance and related with diversity of the freezing tolerance level in addition to the CBF-mediated Cor/Lea expression pathway. Expression patterns were compared between a synthetic wheat line which treated 24M-bM-^DM-^C and 4M-bM-^DM-^C. Total RNA samples were respectively isolated from leaves and crown tissues of the synthetic line grown at normal temperature for 3 weeks and then at 4M-BM-0C for 12 and 6 weeks. Two independent experiments were conducted in each exprement.
Project description:The within-tree variation in wood properties constitutes an exceptional model to study the mechanisms that adjust the different biosynthetic pathways providing substrates with the massive and variable demands of different biosynthetic reactions of cell wall polymers. Although a few genes have been reported as differentially expressed in differentiating compression wood compared to normal or opposite wood, the expression of a larger set of genes is expected to change due the broad range of features that distinguish this reaction wood. By combining the construction of different cDNA libraries with microarray analyses, using samples from different Pinus pinaster provenances collected in different years and geographic locations, we have identified a total of 496 genes that change their expression during differentiation of compression wood (331 up-regulated and 165 down-regulated compared to opposite wood). Consistent with the well-known structural and chemical characteristics of compression wood, a large number of genes involved in the biosynthesis of cell wall components were shown to be up-regulated during compression wood differentiation, including genes involved in synthesis of cellulose, hemicellulose, lignin and lignans. In particular, further analysis of a set of these genes involved in providing S-adenosylmethionine, ammonium recycling, lignin and lignans biosynthesis showed parallel expression profiles to levels of lignin accumulation in cells undergoing xylogenesis in vivo and in vitro. The comparative transcriptomic analysis of compression and opposite wood formation in this work have revealed a broad spectrum of coordinated transcriptional modulation of biosynthetic reactions for different cell wall polymers associated to within-tree variations in softwood structure and composition. In particular, it suggest the occurrence of a mechanism that modulates at transcriptional level genes encoding enzymes involved in S-adenosylmethionine synthesis and ammonium assimilation with coniferyl alcohol demand for lignin and lignan synthesis, as a key metabolic requirement in cells undergoing lignification. Two-condition experiment including dye-swap experiments, Compression Differentiating Xylem vs. Opposite Differentiating Xylem. Biological replicates: 4 compression xylem, 4 opposite xylew, harvested from four different individual pine trees. Two replicates per array.