Several bacterial human pathogens regulate the production of virulence factors by temperature, expressing them only at 37 C. Accordingly we show that the production of all P. aeruginosa virulence factors that are dependent on the QS transcriptional regulator RhlR, but only a fraction that are activated by LasR, are induced at 37 C compared to 30 C or 25 C. The RhlR-dependent induction at 37 C is a posttranscriptional effect due to an RNA thermometer of the ROSE family that thermoregulates the expression of rhlAB operon involved in rhamnolipids production, a virulence associated trait. This RNA structure also affects the expression of the downstream rhlR gene. A second thermometer is present upstream lasI and causes a reduced expression of this gene at lower temperatures without causing a significant decrease of the autoinducer 3-oxo-dodecanoyl homoserine lactone.
Regulation of Pseudomonas aeruginosa virulence factors by two novel RNA thermometers.
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Altering TET dioxygenase levels within physiological range affects DNA methylation dynamics of HEK293 cells.
Specimen part, Cell line, Treatment
View SamplesWe compared TET1 and TET3 overexpressing cells to uninduced cells with endogenous levels of the respective transcript to determine global gene expression changes.
Altering TET dioxygenase levels within physiological range affects DNA methylation dynamics of HEK293 cells.
Specimen part, Treatment
View SamplesWe compared TET triple knockdown cells to control cells treated with non-targeting siRNAs to determine global gene expression changes.
Altering TET dioxygenase levels within physiological range affects DNA methylation dynamics of HEK293 cells.
Cell line, Treatment
View SamplesThe immune system relies on the plasticity of its components to produce appropriate responses to frequent environmental challenges. Dendritic cells (DCs) are critical initiators of innate immunity and orchestrate the later and more specific adaptive immunity. The generation of diversity in transcriptional programs is central for effective immune responses. Alternative splicing is widely considered a key generator of transcriptional and proteomic complexity, but its role has been rarely addressed systematically in immune cells. Here we used splicing-sensitive arrays to assess genome-wide gene- and exon-level expression profiles in human DCs in response to a bacterial challenge. We find widespread alternative splicing events and splicing factor transcriptional signatures induced by an E. coli challenge to human DCs. Alternative splicing acts in concert with transcriptional modulation, but these two mechanisms of gene regulation affect primarily distinct functional gene groups. Alternative splicing is likely to have an important role in DC immunobiology because it affects genes known to be involved in DC development, endocytosis, antigen presentation and cell cycle arrest
Genome-wide analysis of alternative splicing during dendritic cell response to a bacterial challenge.
Specimen part, Treatment
View SamplesRationale: MicroRNAs play key roles in hypertrophic stress responses. miR-378(-3p) is a highly abundant, cardiomyocyte-enriched microRNA whose downregulation in pressure-overload has been suggested as detrimental to the heart. Previous studies have utilized systemic anti-miR or microRNA-encoding virus administration, and thus questions regarding the cardiomyocyte-autonomous roles of miR-378 remain. Objective: To examine whether persistent overexpression of miR-378 in cardiomyocytes alters the phenotype of the unstressed heart, whether its overexpression is beneficial or deleterious in the setting of pressure-overload, and to comprehensively identify its cardiomyocyte-specific effects on mRNA regulation. Methods and Results: Cardiac function was compared in young (10-12 week-old) mice overexpressing miR-378 in the heart under the control of the Myh6 promoter (alphaMHC-miR-378 mice), in older (40 week-old) mice and their age-matched wild-type controls. Older alphaMHC-miR-378 mice exhibited decreased fractional shortening and modest chamber dilation with an increase in cardiomyocyte length. When subjected to pressure-overload, cardiomyocyte length was increased in young alphaMHC-miR-378 mice, but fractional shortening declined precipitously over two weeks. Transcriptome profiling of wild-type and alphaMHC-miR-378 hearts in unstressed and pressure-overload conditions revealed dysregulation of several upstream metabolic and mitochondrial genes in alphaMHC-miR-378 hearts, compromising the reprogramming that occurs during early adaptation to pressure overload. Ago2 immunoprecipitation with mRNA sequencing revealed novel miR-378 cardiac mRNA targets including Akt1 and Epac2 and demonstrated the contextual nature of previously described miR-378 targeting events. Conclusions: Long-term upregulation of miR-378 levels in the heart is not innocuous and exacerbates contractile dysfunction in pressure-overload hypertrophy through numerous signaling mechanisms. Overall design: Cardiac polyadenylated RNA (mRNA) or RISC-seq (total RNA-seq of Ago2 immunoprecipitate) profiles were generated from nontransgenic and transgenic mouse hearts of FVB/N background, on Illumina HiSeq 2000 instruments. Male mice 8-12 weeks of age were used in these studies, and subjected to sham surgery or 2 weeks of pressure-overload via transverse aortic constriction (TAC). 3 nontransgenic sham, 3 transgenic sham, 7 nontransgenic TAC, 7 transgenic TAC, each with mRNA-seq and RISC-seq data.
Cardiac Disease Status Dictates Functional mRNA Targeting Profiles of Individual MicroRNAs.
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View SamplesmiR-133a-3p is a highly abundant cardiomyocyte-enriched microRNA whose expression is persistently decreased in response to pressure overload (or transverse aortic constriction, TAC) in mice. Overexpression of miR-133a in cardiomyocytes of mouse hearts in vivo (under the control of the Myh6 promoter) decreases pressure overload-induced apoptosis and fibrosis. In previous studies using microarray platforms, we detected numerous mRNAs whose transcript levels were altered by either or both of miR-133a overexpression and pressure overload. The data set presented here builds upon our previous study in these mice by examining mRNA-RISC associations (using Ago2-immunoprecipitated RNA) and global mRNA abundances via RNA-sequencing procedures, and tests the hypothesis that mRNAs targeted by overexpressed miR-133a are dissimilar between sham and TAC contexts. Overall design: Cardiac polyadenylated RNA (mRNA) profiles were generated from nontransgenic and transgenic mouse hearts of FVB/N background, on Illumina HiSeq 2000 instruments. Male mice 8-12 weeks of age were used in these studies, and subjected to sham surgery or 1 week of pressure-overload via transverse aortic constriction (TAC). 3 nontransgenic sham, 7 transgenic sham, 5 nontransgenic TAC, 4 transgenic TAC, each with mRNA-seq and RISC-seq (mRNA-seq of Ago2 immunoprecipitate) data.
Cardiac Disease Status Dictates Functional mRNA Targeting Profiles of Individual MicroRNAs.
No sample metadata fields
View SamplesAndrogenic steroids are increasingly used for hormone therapy of postmenopausal women and abused as life style drugs and for doping purposes, though knowledge about associated health risks in females is very limited. In order to understand more about short- and long-term androgen effects on a molecular level, we have analyzed hepatic gene expression in female C57BL/6 mice immediately after subcutaneous treatment with testosterone for 3 weeks and after 12 weeks hormone withdrawal using Affymetrix array technology and quantitative real-time RT-PCR. Among about 14,000 genes examined, 48 were up- and 65 genes were downregulated by testosterone after 3-weeks treatment and about 50% of these changes persisted even 12 weeks after testostrone withdrawal. In addition to obvious risks such as induction of hepatocellular carcinomas and virilization of liver metabolism, testosterone induced a series of changes, as e.g. dysregulation of hepatic gene expression due to incomplete conversion of female to male phenotype in particular downregulation of cytochrom P450 isoforms and sulfotransferases. As a long-term testosterone effect, transcripts emerged in the liver that are normally specific for the exocine pancreas including amylase 2, ribonuclease 1, and several trypsin-, chymotrypsin-, and elastase-like proteases. This transdifferentiation of hepatic to exocrine pancreatic tissue indicates that testosterone can initiate long-lasting differentiation programs, which once induced progress even after androgen withdrawal. This may have far-reaching consequences difficult to foresee implying long-term hazards of testosterone-treatment for female health that have not been taken into account yet.
Testosterone-induced upregulation of miRNAs in the female mouse liver.
Sex, Specimen part, Treatment
View SamplesWe used microarray data to look for gene differentially expressed in the aorta of WT and L-PGDS ko male mice.
Lipocalin-Like Prostaglandin D Synthase but Not Hemopoietic Prostaglandin D Synthase Deletion Causes Hypertension and Accelerates Thrombogenesis in Mice.
Sex, Specimen part
View SamplesThe ability for cut tissues to join together and form a chimeric organism is a remarkable property of many plants, however, grafting is poorly characterized at the molecular level. To better understand this process we monitored genome-wide temporal and spatial gene expression changes in grafted Arabidopsis thaliana hypocotyls. Tissues above and below the graft rapidly developed an asymmetry such that many genes were more highly expressed on one side than the other. This asymmetry correlated with sugar responsive genes and we observed an accumulation of starch above the graft that decreased along with asymmetry once the sugar-transporting vascular tissues reconnected. Despite the initial starvation response below the graft, many genes associated with vascular formation were rapidly activated in grafted tissues but not in cut and separated tissues indicating that a recognition mechanism activated that was independent of functional vascular connections. Auxin which is transported cell-to-cell, had a rapidly elevated response that was symmetric, suggesting that auxin was perceived by the root within hours of tissue attachment to activate the vascular regeneration process. A subset of genes were expressed only in grafted tissues, indicating that wound healing proceeded via different mechanisms depending on the presence or absence of adjoining tissues. Such a recognition process could have broader relevance for tissue regeneration, inter-tissue communication and tissue fusion events. Overall design: We analyzed the poly-adenylated transcriptomes of Arabidopsis thaliana hypocotyle tissue during grafting. Our dataset contains 82 strand-specific samples, whereas each condition is represented by two biological replicates.
Transcriptome dynamics at <i>Arabidopsis</i> graft junctions reveal an intertissue recognition mechanism that activates vascular regeneration.
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