Tristetraprolin is a vertebrate CCCH tandem zinc finger protein that can bind to and destabilize certain mRNAs containing AU-rich element binding sites. zfs1 is the single gene in the fission yeast, Schizosaccharomyces pombe, that encodes a protein containing the critical features of the tristetraprolin zinc finger domain. zfs1 has been linked to pheromone signal transduction control and to the coordination of mitosis, but no biological function has been ascribed to the zfs1 protein. Through a functional genomics approach we compared transcript levels in wild-type and zfs1-deficient S. pombe strains; those elevated in the zfs1-deficient strain were examined for the presence of potential tristetraprolin-like binding sites. One such potential target transcript was encoded by arz1, a gene encoding a protein of unknown function that contains armadillo repeats. arz1 mRNA decay was inhibited in the zfs1-deficient strain when it was expressed under the control of a thiamine-repressible promoter. Mutations within one AU-rich element present in the arz1 3-untranslated region protected this transcript from zfs1-promoted decay, whereas mutating another potential binding site had no effect. Binding assays confirmed a direct interaction between zfs1 and arz1 mRNA-based probes; this interaction was eliminated when key residues were mutated in either zfs1 zinc finger. zfs1 and its targets in S. pombe represent a useful model system for studies of zinc finger protein/AU-rich element interactions that result in mRNA decay.
Characterization of zfs1 as an mRNA-binding and -destabilizing protein in Schizosaccharomyces pombe.
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View SamplesThe paraveinal mesophyll (PVM) of soybean leaves is a layer of laterally expanded cells sandwiched between the palisade and spongy mesophyll chlorenchyma. The vacuoles of PVM cells contain an abundance of a putative vegetative storage protein, VSP (, ). VSP is is constitutively produced, but is up-regulated during sink limitation experiments involving flower, fruit, or vegetative bud removal. Soybean vegetative lipoxygenases (Vlx), consisting of 5 isozymes (Vlx, A-D), have been identified as potential storage proteins because they accumulate to high levels with experimental sink limitation and have been co-localized with VSP to the vacuoles of PVM cells. We re-investigated the sub-cellular locations of these enzymes with TEM immuno-cytochemistry. We employed laser micro-dissection to compared RNA expression of PVM cells with mesophyll chlorenchyma cells, and we performed a micro-array analysis of soybean leaf samples representing a time-course, sink-limitation, experiment. We found that none of the Vlx isozymes co-localize with putative storage proteins in PVM vacuoles, and that our sink limitation experiment (typical of those used in the past) induced a strong up-regulation of stress response genes, simultaneous with the up-regulation of the Vlx isozymes. Our findings do not support a storage function for soybean Vlx.
Experimental sink removal induces stress responses, including shifts in amino acid and phenylpropanoid metabolism, in soybean leaves.
Specimen part, Disease
View SamplesThe paraveinal mesophyll (PVM) of soybean leaves is a layer of laterally expanded cells sandwiched between the palisade and spongy mesophyll chlorenchyma. The vacuoles of PVM cells contain an abundance of a putative vegetative storage protein, VSP (, ). VSP is is constitutively produced, but is up-regulated during sink limitation experiments involving flower, fruit, or vegetative bud removal. Soybean vegetative lipoxygenases (Vlx), consisting of 5 isozymes (Vlx, A-D), have been identified as potential storage proteins because they accumulate to high levels with experimental sink limitation and have been co-localized with VSP to the vacuoles of PVM cells. We re-investigated the sub-cellular locations of these enzymes with TEM immuno-cytochemistry. We employed laser micro-dissection to compared RNA expression of PVM cells with mesophyll chlorenchyma cells; and we performed a micro-array analysis of soybean leaf samples representing a time-course, sink-limitation, experiment. We found that none of the Vlx isozymes co-localize with putative storage proteins in PVM vacuoles, and that our sink limitation experiment (typical of those used in the past) induced a strong up-regulation of stress response genes, simultaneous with the up-regulation of the Vlx isozymes. Our findings do not support a storage function for soybean Vlx.
Experimental sink removal induces stress responses, including shifts in amino acid and phenylpropanoid metabolism, in soybean leaves.
Specimen part
View SamplesSorafenib leads to a survival benefit in patients with advanced hepatocellular carcinoma but its use is hampered by the occurrence of drug resistance. To investigate the molecular mechanisms involved we developed five resistant human liver cell lines in which we studied morphology, gene expression and invasive potential. The cells changed their appearance, lost E-cadherin and KRT19 and showed high expression of vimentin, indicating epithelial-to-mesenchymal transition. Resistant cells showed reduced adherent growth, became more invasive and lost liver-specific gene expression. Furthermore, following withdrawal of sorafenib, the resistant cells showed rebound growth, a phenomenon also found in patients. This cell model was further used to investigate strategies for restoration of sensitivity to sorafenib.
Long-term exposure to sorafenib of liver cancer cells induces resistance with epithelial-to-mesenchymal transition, increased invasion and risk of rebound growth.
Cell line
View SamplesHeritable genetic variants modify cystic fibrosis (CF) clinical phenotypes, e.g., lung disease, age-of-onset of persistent Pseudomonas aeruginosa (P. aeruginosa), and meconium ileus (MI). Previous genome wide association studies (GWAS) have begun to inform the genetic architecture of CF phenotypes. Analyses of gene expression will complement GWAS, as demonstrated by analyses of gene expression in lymphoblastoid cell lines (LCLs) to identify disease-related pathophysiological processes for non-CF complex traits. In this study, global gene expression was measured in RNA from LCLs from 754 CF patients and analyzed for association with lung disease severity, age-of-onset of persistent P. aeruginosa pulmonary infection, and MI at birth. Each phenotype displayed distinct expression associations. Most pathways significantly associated with lung disease were related to membranes, vesicle traffic, and Golgi/endoplasmic reticulum (ER). Pathways containing HLA genes (Class I and II) were significantly associated with both lung and P. aeruginosa phenotypes, but they displayed qualitative differences between phenotypes. MI associated with pathways involving oxidative phosphorylation. The results support the concept that gene expression associated with heritable variation acts to modify phenotypes in CF.
Gene expression in transformed lymphocytes reveals variation in endomembrane and HLA pathways modifying cystic fibrosis pulmonary phenotypes.
Sex
View SamplesSplenic marginal zone lymphoma (SMZL) is a rare, indolent non-Hodgkin’s lymphoma that affects 0.13 per 100,000 persons annually. Overall survival of SMZL is estimated to reach 8 to 11 years in most cases, but up to 30% of SMZL cases develop aggressive presentations resulting in greatly diminished time of survival. SMZL presents with a very heterogeneous molecular profile, making diagnosis problematic and accurate prognosis even less likely. The study herein has utilized this data to assist in identifying a potential diagnostic gene expression signature with highly specific predictive utility for further evaluation among control and SMZL patient samples. Delineation of a unique SMZL signature that could provide diagnostic utility for a malignancy that has historically been difficult to identify. These results should be further investigated and validated in subsequent molecular investigations of SMZL so it may be potentially incorporated into standard oncology practice for improving the understanding and outlook for SMZL patients.
Identification of a Splenic Marginal Zone Lymphoma Signature: Preliminary Findings With Diagnostic Potential.
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View SamplesWe performed Fluidigm C1 single cell sequencing analysis of wild-type and microRNA deficient (Dgcr8 knockout) mouse embryonic stem cells mock treated or transfected with either miR-294 or let-7. Overall design: Wild-type and Dgcr8 knockout cells grown in naïve culture conditions were mock transfected or transfected with miRNA mimics for let-7b or miR-294, single cells were captured on Fluidigm C1 24 hours post-transfection and then prepared for sequencing on Illumina HiSeq1000 following manufacturer''s protocol.
The impact of microRNAs on transcriptional heterogeneity and gene co-expression across single embryonic stem cells.
Specimen part, Subject
View SamplesLDL or Ox-LDL 200ug/ml, which showed no loss of viability after a 48 hour exposure, induced a physiological and pathological transcriptional response, respectively. LDL induced a downregulation of genes associated with cholesterol biosynthesis while ox-LDL induced transcriptional alterations in genes related to inflammation, matrix expansion, lipid metabolism and processing, and apoptosis. Pentraxin-3 was secreted into the culture medium after RPE cells were stimulated with ox-LDL, and immunohistochemically evident in Bruchs membrane of human macular samples with age-related macular degeneration. ARPE-19 cells exposed to 200?g/ml ox-LDL had a 38% apoptosis rate compared to less than 1% when exposed to LDL or untreated controls (p<0.0001).
Oxidized low density lipoproteins induce a pathologic response by retinal pigmented epithelial cells.
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View SamplesNAP - neuroprotective peptide demonstrates increase in neuronal survival when injected into the hippocampus of rats in the model of epilepsy
The microtubule interacting drug candidate NAP protects against kainic acid toxicity in a rat model of epilepsy.
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View SamplesAn increasingly common method for predicting gene activity is genome-wide chromatin immunoprecipitation of ‘active’ chromatin modifications followed by massively parallel sequencing (ChIP-seq). Using a novel ChIP-seq quantification method (cRPKM), we tested the power of such ChIP-seq strategies to predict relative protein and RNA levels at the pre-pro-B and pro-B differentiation stages in early B cell lymphopoiesis. Using a multi-omics approach that compares promoter chromatin status (ChIP-seq; published in GSE:21978) with ongoing active transcription (GRO-seq; published in GSE:40173), steady state mRNA (RNA-seq), inferred mRNA stability, and relative proteome abundance measurements (iTRAQ), we demonstrate that active chromatin modifications at promoters are a good indicator of transcription and steady state mRNA levels. Moreover, we found that promoters with active chromatin modifications exclusively in one of these cell states frequently predicted differentially expressed proteins. However, we found that many genes whose promoters have non-differential but active chromatin modifications also displayed changes in expression of their cognate proteins. This large class of developmentally and differentially regulated proteins that was uncoupled from chromatin status used mostly post-transcriptional mechanisms. Interestingly, the most differentially expressed protein in our B-cell development system, 2410004B18Rik, was regulated by a post-transcriptional mechanism, which further analyses indicated was mediated by an identified miRNA. These data provide a striking example of how our integrated multi-omics data set can be useful in uncovering regulatory mechanisms. Overall design: Total RNA from mouse pre-pro-B and pro-B cells, depleted of rRNA and small RNAs, was sequenced using a strand specific, single end sequencing strategy.
Prediction of Gene Activity in Early B Cell Development Based on an Integrative Multi-Omics Analysis.
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