Expression data from HEK293T cells infected with Shigella or treated with Rapamycin
ABSTRACT: Shigella is an intracellular bacterial pathogen known to activate numerous innate immunity and inflammatory signaling pathways. Many of these pathways are also involved in mTOR signaling. We used HEK293T cell cultures and sought to understand how Shigella infection and rapamycin treatment affect the transcriptome and in particular whether there were commonly affected pathways in the two experimental conditions. 8 samples were used - 2 control that were uninfected/untreated -- 1 sample lost due to RNA degradation, 3 infected with Shigella for 4 hours, and 3 treated with Rapamycin (50 ug/mL) for 4 hours. All samples were from independent experiments. We used the program AltAnalyze to perform pairwise comparisons between Uninfected with Infected, and Uninfected with Rapamycin using default parameters.
Project description:Objective - The TRIB1 locus has been linked to hepatic triglyceride metabolism in mice and to plasma triglycerides and coronary artery disease (CAD) in humans. The lipid associated SNPs identified by genome-wide association studies (GWAS) are located ~ 30 kb downstream from TRIB1 suggesting complex regulatory effects on genes or pathways relevant to hepatic triglyceride metabolism. The goal of this study was to investigate the functional relationship between common SNPs at the TRIB1 locus and plasma lipid traits. Methods & Results - Characterization of the risk locus reveals that it encompasses a gene, TRIB1 associated locus (TRIBAL) comprised of a well conserved promoter region and an alternatively spliced transcript. Bioinformatic analysis and re-sequencing identified a single nucleotide polymorphism (SNP), rs2001844, within the promoter region that associates with increased plasma triglycerides, reduced HDL-C and CAD risk. Furthermore, we show that rs2001844 is an expression trait locus (eQTL) for TRIB1 expression in blood and alters TRIBAL promoter activity in a reporter assay model. The TRIBAL transcript has features typical of long noncoding RNAs (lncRNA), including poor sequence conservation. Modulation of TRIBAL expression had limited impact on either TRIB1 or lipid regulatory genes mRNA levels in human hepatocyte models. In contrast, TRIB1 knockdown markedly increased TRIBAL expression in HepG2 cells and primary human hepatocytes. Conclusions - These studies demonstrate an interplay between a novel locus,TRIBAL, and TRIB1. TRIBAL is located in the GWAS identified risk locus, responds to altered expression of TRIB1, harbors a risk SNP that is an eQTL for TRIB1 expression and associates with plasma triglyceride concentrations. HepG2 hepatoma cells were stably infected with TRIBAL1 or no insert carrying lentiviruses
Project description:Adult mammalian cardiomyocytes (CM) are differentiated post-mitotic cells that lack significant proliferative potential through their inability to reactivate the cell cycle postnatally. In the week after birth, the mammalian heart goes through distinct stages of cell cycle progression and differentiation that govern the development of the mature adult CM phenotype. By establishing the fundamental framework of the molecular signals governing these early events after birth, a potential treatment strategy that restores the heart’s ability to proliferate, and in theory, undergo ‘repair’ after injury could be developed. At 0 days (d), 1d, 3d, 5d, 7d, 10d, and 15d after birth, hearts from C57BL/6J wild-type mice were excised and processed for total RNA isolation. Samples were analyzed by genome-wide messenger RNA (mRNA) microarray profiling. All experiments were performed on age- and sex-matched mice, with equal ratio of male to female mice.
Project description:Genome-wide transcriptome analyses of transgenic mice, that express Cre recombinase flanked by mutated estrogen receptors (MerCreMer; mcm), and carry loxP-flanked sequences of p53 and Mdm2 was performed in the presence and absence of Tamoxifen.<br>The molecular mechanisms underlying heart failure remain poorly understood. As such, identifying the factors which effectively maintain cardiac tissue homeostasis is of great scientific and clinical importances. The tumor suppressor Trp53 (p53) inhibits cell growth after acute stress by regulating gene transcription. The mammalian genome contains hundreds of p53 binding sites. However, whether p53 participates in the regulation of cardiac tissue homeostasis under normal conditions is not known. To examine the physiologic consequences of p53 and Mdm2 ablation in adult cardiomyocytes in vivo, cardiac morphology and function were assessed in conditional mutant mice.
Project description:Measles virus infects serum activated airway epithelial cells and many adenocarcinoma cell lines. A microarray analysis was performed on virus permissive versus non-permissive cells. Membrane protein genes that were upregulated in permissive cells were tested as receptor/entry factors. Membrane protein genes that were upregulated in smooth airway epithelial cells (SAEC) following growth in 10% fetal calf serum that made the cell line permissive to measles virus were identified. Membrane protein genes that were upregulated in adenocarcinoma cells that were permissive to wild type measles virus infection were identified. [SAEC]: Airway cells (SAEC) grown in serum free media (SAGM) were purchaced from Lonza. Half the cells were cultured in SAGM, the other half were transferred into Dulbecco's 10% fetal calf serum for 24 hrs. RNA was harvested from the cells by the Qiagen RNAeasy [Adenocarcinoma cells]: MCF7, MDA-MB-468, T47D, NCI-H358, NCI-H125, MGH24 cells were permissive and A549 and MDA-MB-231 cells were non-permissive.
Project description:In many mammals, halogenated aromatic hydrocarbon (HAH) exposure causes wasting syndrome, defined as lethal weight loss as a result of severe and persistent hypophagia. The most potent HAH in causing wasting is 2,3,7,8-tetrachlorodibenzo-ρ-dioxin (TCDD), which exerts its toxic effects through the aryl hydrocarbon receptor (AHR) – a transcription factor. Because TCDD toxicity is thought to predominantly arise from dysregulation of AHR-transcribed genes, we hypothesized that wasting syndrome is due to TCDD-induced dysregulation of genes involved in regulation of food-intake. We therefore focused on the hypothalamus, as it is the regulatory center of food-intake and energy balance in the central nervous system. We profiled mRNA abundance in hypothalamic tissue from two rat strains with widely differing sensitivities to wasting syndrome: TCDD-sensitive Long-Evans rats and TCDD-resistant Han/Wistar rats, 23 hours after exposure to TCDD (100 μg/kg) or corn oil vehicle. We found that TCDD exposure caused minimal transcriptional dysregulation effects in the hypothalamus, with only 6 genes changed in Long-Evans rats and 15 genes in Han/Wistar rats. Two of the most dysregulated genes were Cyp1a1 and Nqo1, which are induced by TCDD across a wide range of tissues and are considered sensitive markers of TCDD exposure. The minimal response of the hypothalamic transcriptome to a lethal dose of TCDD at an early time-point suggests that the hypothalamus is not the predominant site of initial events leading to hypophagia and associated wasting. TCDD may affect feeding behaviour via events upstream or downstream of the hypothalamus, and further work is required to evaluate this at the level of individual hypothalamic nuclei and subregions. Two strains, each with drug-treated vs vehicle-control
Project description:2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) is an environmental contaminant that produces myriad toxicities across various experimental models. In rodents alone, there is huge divergence in the toxicological response across species, between strains within a species and even between sexes within a strain. This difference in sensitivities between sexes has been characterized in multiple rodent models, however with contrasting results: the severity of toxicity is greater in female rats than in males while male mice and guinea pigs are more sensitive to the effects of TCDD than females. While the presence of estrogens or androgens has a known impact on response, the specific transcriptional events that cause this difference remain unclear. We sought to characterize the transcriptional environment of male and female C57BL/6 mice treated with 500 μg/kg TCDD and followed across a time-course. This dose was chosen as it is greater than the LD50 for male mice yet produces minimal effects in females. Additionally, evaluation along a time-course allows for the detection of specific changes that occur throughout the development of phenotypic toxicities. The transcriptional profile across the time-course was highly divergent between the sexes. Female TCDD-treated mice demonstrated a large number of altered transcripts as early as 6 hours following treatment, suggesting a large primary response, possibly indicative of the activation of numerous defense mechanisms. Conversely, male animals showed the greatest TCDD-mediated response 144 hours following exposure, potentially implicating significant secondary responses for the increased appearance of TCDD toxicities. Nr1i3 is statistically significantly altered at all time-points in the sensitive male animals. This mRNA encodes a transcription factor (constitutive androstane receptor; CAR) involved in the regulation of xenobiotic metabolism, as well as lipid metabolism, cell cycle and apoptosis. In particular, increased levels of CAR may result in induction of the anti-apoptotic gene Gadd45b and carboxylesterase Ces1d, both of which we identify as transcriptionally altered and may be responsible for phenotypic hepatic abnormalities, such as steatohepatitis and tumor formation. Further evaluation across studies of mice and rats into the role of Nr1i3 and associated genes are crucial to enhance our understanding of various TCDD-induced toxicities. Adult male and female C57BL/6 mice were treated by gavage with either 500 ug/kg TCDD in corn oil or corn oil vehicle alone. Animals were euthanized at either 6, 24, 72 or 144 hours after treatment and tissues were harvested. RNA was isolated from hepatic tissue and the transcriptome for each animal assayed on an individual microarray. Please note that 7 samples (out of total 65 samples) were identified as outliers and therefore the data were processed without the outliers as well. The normalized data without outliers were provided in the 'normalized_data_without_outliers.txt' file.
Project description:2,3,7,8–tetrachlorodibenzo-p-dixion (TCDD) is a dioxin congener that causes a wide range of toxic effects in rodent species. Previous studies discovered that males and females of the same species display different sensitivities to TCDD exposure. Although it is now clear that most TCDD-induced toxic outcomes are mediated by the Aryl Hydrocarbon Receptor (AHR), a transcription factor, the mechanism of sex-specific responses to TCDD remains largely unknown. To understand the differential sensitivity in male and female animals, we profiled the hepatic transcriptomic responses to single doses of TCDD (125, 250, 500, or 1000 µg/kg) in male and female C57BL6 mice. Several key findings were revealed by our study: 1) transcriptomic profiles varied largely between sexes at all doses; 2) the mRNA abundance profiles of female mice were less altered from basal level; 3) the alteration of ‘AHR-core’ genes were consistent regardless of sex; 4) a list of sex-specific TCDD-responsive genes were identified, including Fmo3 and Nr1i3 upregulated in male mice and Sult3a1 downregulated in female mice; 5) functional analysis of these candidate genes showed various biological pathway enrichments in a sex-dependent manner. Our study shows that the sex-dependent sensitivities to TCDD exposure are associated with a set of sex-specific TCDD-responsive genes that are indirectly regulated by AHR activity. The exact roles of these genes in response to TCDD exposure are not clear and require further investigation. Adult male and female C57BL/6 mice were treated by gavage with one single-dose TCDD (125, 250, 500, or 1000 μg/kg) in corn oil or corn oil vehicle alone. Animals were euthanized at 96 hours after treatment and tissues were harvested. RNA was isolated from hepatic tissue and the transcriptome for each animal assayed on an individual microarray.
Project description:The aryl hydrocarbon receptor (AHR) mediates most of the toxic effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). However, TCDD toxicity phenotypes vary widely between species, strains and even between sexes within a strain. While the exact reasons for this variation remain unclear, it is thought to be related to differences in the structure of the AHR. Previous studies comparing the downstream effects of TCDD exposure between animals with different AHR isoforms have been confounded by the genetic differences between these model systems. To address this issue conclusively, we evaluated three transgenic mouse lines, each of which express a different rat AHR isoform (rWT, DEL, and INS) from two strains of rat with highly divergent TCDD-susceptibilities, within identical genetic backgrounds. Here we profile hepatic transcriptomic responses following exposure to TCDD, and use these to identify transcripts associated with toxicity. We have confirmed that the variation in toxicity is inherent to the AHR isoform. Additionally, we note the enhanced activity of the modified transactivation domain of the DEL isoform, relative to the INS isoform, and provide further evidence that the INS isoform is responsible for the high resistance to TCDD observed in H/W rats. We also uncover several candidate genes that were consistently differentially expressed in TCDD-sensitive mice and rats. Adult male transgenic mice were treated by gavage with 0, 125, 250, 500, or 1000 µg/kg TCDD dissolved in corn oil vehicle. Mice were euthanized 4 days following treatment and liver tissue was harvested for analysis. RNA was isolated and the transcriptome for each animal assayed on separate microarrays.
Project description:Rodents exposed to the environmental contaminant, TCDD, suffer from a number of acute and chronic toxicities, including lethality and a wasting syndrome. Hypothesizing that the wasting syndrome may be caused by changes in adipose tissue -- either in its hormonal regulation or in homeostatic effects -- we profiled the transcriptional response of rat white adipose to TCDD. We employed two separate rat strains: the Long-Evans strain is sensitive to TCDD toxicities while the Han/Wistar strain is over four orders of magnitude more resistant. One day after TCDD exposure few genes were altered in either strain, but after four days a modest number of transcriptional alterations were observed. Strikingly, TCDD had far fewer effects than did a feed-restriction protocol intended to mimic the wasting syndrome itself. Notably several classic TCDD-responsive genes were modulated at all time-points, including Cyp1a1, Cyp1b1, and Nqo1. We therefore concluded that rat adipose tissue is unlikely to be the primary driver of the wasting syndrome, and that another tissue is likely involved. Two strains, each with drug-treated vs. vehicle-control