The nuclear receptor peroxisome proliferator-activated receptor alpha (PPAR) regulates responses to chemical or physical stress in part by altering expression of genes involved in proteome maintenance. Many of these genes are also transcriptionally regulated by heat shock (HS) through activation by HS factor-1 (HSF1). We hypothesized that there are interactions on a genetic level between PPAR and the HS response mediated by HSF1. Wild-type and PPAR-null mice were exposed to HS, the PPAR agonist WY-14,643 (WY), or both; gene and protein expression was examined in the livers of the mice 4 or 24 hrs after HS. Gene expression profiling identified a number of Hsp family members that were altered similarly in both mouse strains. However, most of the targets of HS did not overlap between strains. A subset of genes was shown by microarray and RT-PCR to be regulated by HS in a PPAR-dependent manner. HS also down-regulated a large set of mitochondrial genes specifically in PPAR-null mice that are known targets of PPARg co-activator 1 (PGC-1) family members. Pretreatment of PPAR-null mice with WY increased expression of PGC-1b and target genes and prevented the down-regulation of the mitochondrial genes by HS. A comparison of HS genes regulated in our dataset with those identified in wild-type and HSF1-null mouse embryonic fibroblasts indicated that although many HS genes are regulated independently of both PPAR and HSF1, a number require both factors for HS responsiveness. These findings demonstrate that the PPAR genotype has a dramatic effect on the transcriptional targets of HS and support an expanded role for PPAR in the regulation of proteome maintenance genes after exposure to diverse forms of environmental stress including HS.
Analysis of the heat shock response in mouse liver reveals transcriptional dependence on the nuclear receptor peroxisome proliferator-activated receptor alpha (PPARalpha).
Sex, Age, Specimen part
View SamplesThe bird cherry-oat aphid (Rhopalosiphum padi L.) (Homoptera: Aphididae) is an important pest on cereals causing plant growth reduction but no specific leaf symptoms. Breeding of barley (Hordeum vulgare L.) for R. padi resistance shows that there are several resistance genes involved, reducing aphid growth. In an attempt to identify candidate sequences for resistance-related genes, we performed a microarray analysis of gene expression after two days of aphid infestation in two susceptible barley lines and two genotypes with partial resistance. One of the four lines is a descendant of two of the other genotypes. The analysis revealed large differences in gene induction between the four lines, indicating substantial variation in response even between closely related genotypes. Genes induced in the aphid-infested tissue were mainly related to defence, primary metabolism and signalling. Only twenty-four genes were induced in all lines, none of them related to oxidative stress or secondary metabolism. Few genes were down-regulated and none of those was common to all four lines. There were differences in aphid-induced gene regulation between resistant and susceptible lines, and results from control plants without aphids also revealed differences in constitutive gene expression between the two types of lines. Candidate sequences for both induced and constitutive resistance factors have been identified, among them a proteinase inhibitor, a Ser/Thr kinase and several thionins.
Microarray analysis of the interaction between the aphid Rhopalosiphum padi and host plants reveals both differences and similarities between susceptible and partially resistant barley lines.
No sample metadata fields
View SamplesWe used microarrays to compare the gene expression profiles of different H1N1 isolates (seasonal and pandemic) in lung epithelial cells in vitro.
Early host responses of seasonal and pandemic influenza A viruses in primary well-differentiated human lung epithelial cells.
Specimen part
View SamplesCurrent methods to analyze gene expression measure steady-state levels of mRNA. In order to specifically analyze mRNA transcription, a technique has been developed that can be applied in-vivo. The technique is referred with the acronym NIAC-NTR (Non Invasive Application and Capture of Newly Transcribed RNA). This method makes use of the cellular pyrimidine salvage pathway and is based on affinity-chromatographic isolation of thiolated mRNA. When combined with data on mRNA steady-state levels, this method is able to assess the relative contributions of mRNA synthesis and degradation/stabilization. It overcomes limitations associated with currently available methods such as mechanistic intervention that disrupts cellular physiology, or the inability to apply the techniques in-vivo. The method has been applied to a model of serum response of cultured primary mouse embryonic fibroblasts.
Microarray analysis of newly synthesized RNA in cells and animals.
No sample metadata fields
View SamplesCurrent methods to analyze gene expression measure steady-state levels of mRNA. In order to specifically analyze mRNA transcription, a technique has been developed that can be applied in-vivo in intact cells and animals. The technique is referred with the acronym NIAC-NTR (Non Invasive Application and Capture of Newly Transcribed RNA). This method makes use of the cellular pyrimidine salvage pathway and is based on affinity-chromatographic isolation of thiolated mRNA. When combined with data on mRNA steady-state levels, this method is able to assess the relative contributions of mRNA synthesis and degradation/stabilization. It overcomes limitations associated with currently available methods such as mechanistic intervention that disrupts cellular physiology, or the inability to apply the techniques in-vivo. The method was applied to study renal ischemia reperfusion injury, demonstrating its applicability for whole organs in-vivo.
Microarray analysis of newly synthesized RNA in cells and animals.
Age
View SamplesThe C57BL/6.NOD-Aec1Aec2 mouse is a model for primary Sjgrens syndrome and was constructed by introducing two genetic intervals derived from the NOD mouse that confers Sjgrens syndrome (SjS)-like disease in SjS-non-susceptible C57BL/6 mice.
Transcriptional landscapes of emerging autoimmunity: transient aberrations in the targeted tissue's extracellular milieu precede immune responses in Sjögren's syndrome.
Sex, Age, Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
AP-1 Is a Key Regulator of Proinflammatory Cytokine TNFα-mediated Triple-negative Breast Cancer Progression.
Specimen part, Cell line, Treatment
View SamplesTriple-negative breast cancer (TNBC) represents a highly aggressive form of breast cancer with limited treatment options. Proinflammatory cytokines such as TNFalpha can facilitate tumor progression and metastasis. However, our knowledge of the molecular mechanisms underlying TNBC progression mediated by inflammation is still limited. Here, we define the AP-1 transcription factor c-Jun cistrome, which is comprised of 13800 binding sites responsive to TNFalpha-induced signaling in TNBC cells. In addition, we show that c-Jun regulates nearly a third of the TNFalpha-elicited transcriptome. Expression of the c-Jun-regulated pro-invasion gene program is strongly associated with clinical outcomes in TNBCs. Mechanistically, we demonstrate that c-Jun drives TNFalpha-mediated TNBC tumorigenicity by transcriptional regulation of Ninj1. As exemplified by the c-Jun bound CXC chemokine genes clustered on chromosome 4, we demonstrate that NF-kB might be a pioneer factor and is required for the regulation of TNFalpha-inducible inflammatory genes, whereas c-Jun has little effect. Together, our results uncover AP-1 as an important determinant for inflammation-induced cancer progression, rather than inflammatory response.
AP-1 Is a Key Regulator of Proinflammatory Cytokine TNFα-mediated Triple-negative Breast Cancer Progression.
Specimen part, Cell line, Treatment
View SamplesTibial muscular dystrophy (TMD) is a late onset, autosomal dominant distal myopathy that results from mutations in the two last domains of titin. The cascade of molecular events leading from the causative Titin mutations to the preterm death of muscle cells in TMD is largely unknown. To identify these components, we used gene expression profiling of muscle biopsies from TMD patients and healthy controls.
Gene expression profiling in tibial muscular dystrophy reveals unfolded protein response and altered autophagy.
Sex, Specimen part, Disease, Disease stage, Subject
View SamplesFibroblast growth factor-23 (FGF23), a circulating protein produced in bone, causes renal inorganic phosphate (Pi) wasting by down-regulation of sodium phosphate co-transporter 2a (Npt2a). The mechanism behind this action is unknown. We have previously generated transgenic mice (TG) expressing human wild-type FGF23 under the control of the 1 (I) collagen promoter. In this study we performed a large scale gene expression study of kidneys from TG mice and wild-type littermates. Several genes that play a role in Pi regulation had decreased expression levels, such as Npt2a, but also Pdzk1 which is a scaffolding protein known to interact with NPT2a. Importantly, the Klotho gene, a suggested crucial co-factor for FGF23 receptor binding and activation, was the most affected decreased gene. However, other genes proposed to regulate Pi levels, such as secreted Frizzled Related Protein 4 (sFRP4), Na+/H+ exchanger regulatory factor 1 (NHERF1) and the FGF-receptors 1-4, revealed no changes. Interestingly, expression levels of inflammatory response genes were increased and histological analysis revealed tubular nephropathy in the TG mice kidneys. In conclusion, FGF23 TG mice have altered kidney gene expression levels of several genes thought to be part of Pi homeostasis and an increase in inflammatory response genes, data supported by histological analysis. These findings may lead to further understanding of how FGF23 mediates its actions on renal Pi regulation.
Gene expression analysis of kidneys from transgenic mice expressing fibroblast growth factor-23.
Age
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