Transcription profiling of mouse erythroblasts during erythroid differentiation
ABSTRACT: The I/11 and R10 erythroid progenitor cell line was cultivated in serum free medium (StemPro34) supplemented with Epo (0,5U/ml), SCF (100ng/ml) and dexamethasone (10-6M). To identify genes specifically regulated by Epo/SCF-induced polysome recruitment, cells were factor deprived for 4h and subsequently treated for 2h with 5U/ml Epo and 200ng/ml SCF or left untreated. Subsequently we isolated both total and polysome bound mRNA from each condition, which was hybridised to oligonucleotide arrays (Affymetrix). Analysis of data with Rosetta Resolver allowed to identify and compare Epo/SCF induced gene expression in total and polysome bound RNA. To assess gene expression during erythroid differentiation, cells were induced to differentiate in presence of 5U/ml Epo and 0.5mg/ml Fe-loaded transferrin. Polysome bound mRNA was isolated from cells proliferating in presence of Epo, SCF and dexamethasone (renewal conditions), and from cells induced to differentiate for 48h or 60h.
Project description:Translational control is a key regulatory step in the expression of genes as proteins. In plant cells, translational efficiency of mRNAs differs on different mRNA species, and the efficiency dynamically changes in various conditions. To gain a global view of translational control throughout growth and development, we performed genome-wide analysis of polysome association of mRNA over growth and leaf development in Arabidopsis thaliana by applying the mRNAs in polysome to DNA microarray. This analysis revealed that the degree of polysome association of mRNA had different levels depending on mRNA species, and the polysome association changed greatly throughout growth and development for each. In the growth stage, transcripts showed varying changes in polysome association from strongly depressed to unchanged degree, with the majority of transcripts showing dissociation from ribosomes. On the other hand, during leaf development, the polysome association of transcripts showed a normal distribution from repressed to activated mRNAs when comparing between expanding and expanded leaves. In addition, functional category analysis of the microarray data suggested that translational control has a physiological significance in plant growth and development process, especially in category of signaling and protein synthesis. Besides this, we compared changes in polysome association of mRNAs between various conditions and characterized translational controls in each. This result suggested that mRNAs translation might be controlled by complicated mechanisms for response to each condition. Our results highlight the importance of dynamic changes in mRNA translation in plant development and growth. Experiment using two-flactionated mRNA in 4 developmental stages, Polysomal mRNA vs. total mRNA. Biological replicates: 2. Compared 2DAG and 21DAG, or Young leaves and Mature leaves.
Project description:Translational profiling of mouse cardiac tissue treated with 25mg/kg DMNQ in 10 ml/kg arachis oil over an acute time course (0.5-120 hours) compared to time matched control animals treated with 10ml/kg saline Two colour microarrays with time matched controls vs 25mg/kg DMNQ cardiac tissue. Before microarray analysis RNA separated on a sucrose density gradient into those mRNAs activitly undergoing translation (polysomes) and those not (monosomes) with control monosomes and treated monosomes on one set of arrays, and polysome control and polysome treated on another set of microarrays. The normalized Log2 of the monosomes was subtracted from the respective Log2 of the polysomes (on Series record). Time points studied were 0.5, 1, 2, 12, 24 and 120 hours following dosing, biological replicates n=3 independent animals at each time point, technical replicates (reverse labelling) n<1. One array printed onto two slides (A and B), one replicate per array.
Project description:Heat stress is one of the most prominent and deleterious environmental threads affecting plant growth and development. Upon high temperatures, plants launch specialized gene expression programs that promote stress protection and survival. These programs involve global and specific changes at the transcriptional and translational levels. However the coordination of these processes and their specific role in the establishment of the heat stress response is not fully elucidated. In this report, we have carried out a genome-wide analysis to simultaneously monitor the individual changes in the transcriptional and translational mRNA levels of Arabidopsis thaliana seedlings after the exposure to a heat shock stress. Our results demonstrated that, superimposed to transcription, translation exerts a wide but dual regulation of gene expression. For the majority of mRNAs, translation is severely repressed, causing a decreased of 50% of the association of the bulk of mRNAs to polysomes. However, some relevant mRNAs involved in different aspects of homeostasis maintenance follow a differential pattern of translation. Analysis of the sequence of the differentially translated mRNAs unravels that some features, like the 5´UTR G+C content and the cDNA length, may take part in the discrimination mechanisms for mRNA polysome loading. Among the differential translated genes stand out master regulators of the stress response, highlighting the main role of translation in the early establishment of physiological response of plants to elevated temperatures. In total 8 ATH1 Affymetrix GeneChips were hybridized with all combinations of two factors: total mRNA/polysome-bound-RNA; 22ºC/38ºC. Two biological replicates per sample type were performed.
Project description:Polysomal profiling results showed that global translation was enhanced in roots after 8 h and in shoots after 24 h of GSH treatment. By performing transcriptomic analyses of steady-state and polysome-bound mRNAs in GSH-treated plants, we reveal that GSH has more a greatersubstantial impact on translational change. GSH-induced gene expression in Arabidopsis roots and shoots was measured seperately at 8 and 24 hours after exposure to 100 μM GSH. Two independent experiments were performed at each time (8 or 24 hours).
Project description:The goal was to measure the expression and polysome association of genes with polysomes in human embryonic stem cells H9 human embryonic stem cells were kept in pluripotent conditions. Total RNA and polysome extracts were isolated.
Project description:Translational profiling of mouse cardiac tissue treated with 15mg/kg doxorubicin in 10 ml/kg saline over an acute time course (0.5-120 hours) compared to time matched control animals treated with 10ml/kg saline. Two colour microarrays with time matched controls vs 15mg/kg doxorubicin cardiac tissue. Before microarray analysis, RNA is separated on a sucrose density gradient into those mRNAs activity undergoing translation (polysomes) and those not (monosomes) with control monosomes and treated monosomes on one set of arrays, and polysome control and polysome treated on another set of microarrays. Thealized Log2 of the monosomes was subtracted from the respective Log2 of the polysomes (on Series record). Time points studied were 0.5, 1, 2, 12, 24 and 120 hours following dosing, biological replicates n=3 independent animals at each time point, technical replicates (reverse labelling) n<1. One array printed onto two slides (A and B), one replicate per array.
Project description:Identification of genes in DNA damage response and repair pathways differentially transcribed or translated under anoxia or hypoxia in GM05757 normal human fibroblast cells and DU145 human prostate cancer cells. Comparison of mRNA abundance and translation efficiency of genes in DNA damage response and repair pathways in selected anoxia/hypoxia-treated cells with those in normoxia-treated controls.
Project description:We investigated genome-wide changes in mRNA translation in Arabidopsis thaliana T87 suspension cell cultures which thought to be one of the host materials for bioreactor. Global translational repression was observed in cells of 8 day after inoculation that is thought to be stressful condition by the nutrient deficiency and hypoxia. This suggested the negative effect of the global translational repression on transgene expression. On the other hand, previous study using heat stress showed that some mRNAs were actively translated under such stressful condition, suggesting the existence of mRNA that were actively translated in cells of 8 day after inoculations. To identify mRNAs that escape global translational repression on 8 day and its cis-elements would be the 1st step to make the system for higher transgene expression by the escaping global translational repression. To this end, we subjected polysomal RNA and non-polysomal RNA from sucrose gradient fractionated cell lysates to the co-hybridization on Agilent Arabidopsis 4 Oligo Microarrays. The ratio of signal intensities (polysomal RNA: total RNA) was used as an indicator of the translation state for each transcript. Experiment using two-fractionated mRNA, Polysomal mRNA vs. total mRNA. Biological replicates: 1
Project description:Gene expression in the total RNA and heavy polysome fractions of Eif4g3 siRNA treated lymph node stromal cells (LNSCs) compared to control-sIRNA treated samples The objective of this study was to identify genes whose translation are reduced after silencing Eif4g3 (the gene which encodes the translation initiation factor eIF4GII). Genes with reduced translation are expected to have lower expression in RNA samples isolated from heavy polysomes but not in RNA samples isolated from whole cell lysates. LNSCs were grown in 10 cm plates, allowed to reach ≥ 80% confluency and then transfected with 400 pmol of control or Eif4g3 siRNA using Lipofectamine 2000. 7 plates were transfected with control or Eif4g3 siRNA. Total RNA was extracted from cells 48h after transfection. To isolate RNA from the heavy polysome fractions, cells were pooled, lysed and fractionated on a 10% to 60% continuous sucrose gradient. Fractions containing the heavy polysome fractions were pooled. RNA was extracted from these samples and used for microarrays on the Agilent Whole Mouse Genome Microarray Kit, 4×44K 2-color arrays.
Project description:Background and objectives: This report describes an unusual presentation of severe hypertension (HTN) in a subset of pediatric kidney recipients treated with a steroid avoidance pediatric renal transplantation protocol. The HTN was secondary to atypical, reno-vascular abnormalities (RVA) of the transplanted vasculature, temporally associated with erythropoietin (EPO) use. Design, setting, participants, and measurements: To investigate the clinical significance underlying this event, a retrospective clinical study of 100 pediatric renal transplants was undertaken (50 steroid-free and 50 matched steroid-based controls), with peripheral blood transcriptional analysis of four RVA patients and controls. Results: Regardless of a higher observed incidence of anemia (p < 0.001) and greater overall EPO usage in the first post-transplant year in steroid-free patients, the incidence of new-onset HTN at one yr was significantly less in the steroid-free cohort (p = 0.03). Nevertheless, early EPO (first week post-transplant) was significantly associated with the combinatory findings of new-onset HTN (p = 0.03) and RVA (p = 0.007). Molecular mechanisms of RVA injury were investigated further by peripheral blood cDNA microarray gene expression profiling. A panel of 42 transcripts differentiated patients with RVA and HTN from three sets of matched controls, with and without HTN and EPO use, with 100% concordance (p < 0.001). The biological processes governed by these significant genes suggest a role for EPO regulation of growth factor receptor ubiquitination as a putative mechanism for renal vascular injury. Conclusion: This study cautions against the use early post-transplant use of EPO in immunosuppression regimens with steroid minimization/avoidance, which may have an increased incidence of post-transplant anemia. Set of arrays organized by shared biological context, such as organism, tumors types, processes, etc. Disease State: patient with high blood pressure Keywords: Logical Set Using regression correlation