The heat shock response (HSR) is a mechanism to cope with proteotoxic stress by inducing the expression of molecular chaperones and other heat shock response genes. The HSR is evolutionarily well conserved and has been widely studied in bacteria, cell lines and lower eukaryotic model organisms. However, mechanistic insights into the HSR in higher eukaryotes, in particular in mammals, are limited. We have developed an in vivo heat shock protocol to analyze the HSR in mice and dissected heat shock factor 1 (HSF1)-dependent and -independent pathways. Whilst the induction of proteostasis-related genes was dependent on HSF1, the regulation of circadian function related genes, indicating that the circadian clock oscillators have been reset, was independent of its presence. Furthermore, we demonstrate that the in vivo HSR is impaired in mouse models of Huntington's disease but we were unable to corroborate the general repression of transcription after a heat shock found in lower eukaryotes. Overall design: RNA-Seq was performed on mRNA isolated from quadriceps femoris muscle of 24 mice. These mice were of wild type, R6/2, and Hsf1-/- genotypes. Two mice of each genotype were tested in four conditions: (1) heat shock, (2) control heat shock, (3) HSP90 inhibition (NVP-HSP990), and (4) HSP90 inhibition vehicle.
HSF1-dependent and -independent regulation of the mammalian in vivo heat shock response and its impairment in Huntington's disease mouse models.
Age, Specimen part, Treatment, Subject
View SamplesHuntington's disease (HD) is an inherited neurodegenerative disorder of which skeletal muscle atrophy is a common feature, and multiple lines of evidence support a muscle-based pathophysiology in HD mouse models. Inhibition of myostatin signaling increases muscle mass, and therapeutic approaches based on this are in clinical development. We have used a soluble ActRIIB decoy receptor (ACVR2B/Fc) to test the effects of myostatin/activin A inhibition in the R6/2 mouse model of HD. Transcriptional profiling of muscle in treated and untreated wild-type and R6/2 mice was performed to analyze the effect of the ActRIIB decoy on genes and pathways involved in maintaining normal muscle physiology as well as those dysregulated due to the mutant HTT gene mutation. Overall design: RNAseq was performed on tibialis muscle from wild-type, wildtype + decoy, R6/2 and R6/2 + decoy; N = 10 per group. RNAseq was done on an Illumina Hi-seq 2000. Paired-end sequencing was obtained, 4-plexed across lanes for a minimum of 38 million 50mer paired reads per sample
Myostatin inhibition prevents skeletal muscle pathophysiology in Huntington's disease mice.
Sex, Age, Specimen part, Cell line, Treatment, Subject
View SamplesAlthough type III interferons (IFN), also known as IFN-? or IL28/IL-29, restrict infection by several viruses, their mechanism of inhibitory action has remained uncertain. We used recombinant IFN-? and mice lacking the IFN-? receptor (IFNLR1) to evaluate the effect of IFN-? on infection with West Nile virus (WNV), an encephalitic flavivirus. Cell culture studies in keratinocytes and dendritic cells showed no direct antiviral effect of exogenous IFN-? even though ISGs were induced. Correspondingly, we observed no differences in WNV burden between wild-type and Ifnlr1-/- mice in the draining lymph node, spleen, and blood. However, we detected earlier dissemination and increased WNV infection in the brain and spinal cord of Ifnlr1-/- mice, yet this was not associated with a direct antiviral effect on infection of neurons. Instead, an increase in blood-brain barrier (BBB) permeability was observed in Ifnlr1-/- mice. Accordingly, treatment of mice with pegylated IFN-?2 resulted in decreased BBB permeability, reduced WNV infection in the brain without impacting viremia, and improved survival against lethal virus challenge. An in vitro model of the BBB showed that IFN-? signaling in brain microvascular endothelial cells increased transendothelial electrical resistance, decreased virus movement across the barrier, and modulated tight junction protein localization in a protein synthesis- and STAT1-independent manner. Our data establish a novel indirect antiviral function of IFN-? in which non-canonical signaling through IFNLR1 tightens the BBB and restricts viral neuroinvasion and pathogenesis. This finding suggests new clinical applications for IFN-? in treating viral or autoimmune diseases. Overall design: Transcriptome profiling of bone-marrow derived Dendritic cells(BMDCs), treated with either Serum Free Media(Mock), interferon beta(IFNb), or interferon lambda(IFNL) for 6 hours.
Interferon-λ restricts West Nile virus neuroinvasion by tightening the blood-brain barrier.
No sample metadata fields
View SamplesTo better understand the role of QscR in P. aeruginosa gene regulation and to better understand the relationship between QscR, LasR and RhlR control of gene expression we used transcription profiling to identify a QscR-dependent regulon. Our analysis revealed that QscR activates some genes and represses others. Some of the repressed genes are not regulated by the LasR-I or RhlR-I systems while others are. The LasI-generated 3-oxododecanoyl-homoserine lactone serves as a signal molecule for QscR. Thus QscR appears to be an integral component of the P. aeruginosa quorum sensing circuitry. QscR uses the LasI-generated acyl-homoserine lactone signal and controls a specific regulon that overlaps with the already overlapping LasR and RhlR-dependent regulons.
A distinct QscR regulon in the Pseudomonas aeruginosa quorum-sensing circuit.
No sample metadata fields
View SamplesRosiglitazone (Rosi), a member of the thiazolidinedione class of drugs used to treat type 2 diabetes, activates the adipocyte-specific transcription factor peroxisome proliferator-activated receptor gamma (PPARg). This activation causes bone loss in animals and humans, at least in part due to suppression of osteoblast differentiation from marrow mesenchymal stem cells (MSC). In order to identify mechanisms by which PPARg2 suppresses osteoblastogenesis and promotes adipogenesis in MSC, we have analyzed the PPARg2 transcriptome in response to Rosi. A total of 4,252 transcriptional changes resulted when Rosi (1 uM) was applied to the U-33 marrow stromal cell line, stably transfected with PPARg2 (U-33/g2), as compared to non-induced U-33/g2 cells. Differences between U-33/g2 and U-33 cells stably transfected with empty vector (U-33/c) comprised 7,928 transcriptional changes, independent of Rosi. Cell type-, time- and treatment-specific gene clustering uncovered distinct patterns of PPARg2 transcriptional control of MSC lineage commitment. The earliest changes accompanying Rosi activation of PPARg2 included adjustments in morphogenesis, Wnt signaling, and immune responses, as well as sustained induction of lipid metabolism. Expression signatures influenced by longer exposure to Rosi provided evidence for distinct mechanisms governing the repression of osteogenesis and stimulation of adipogenesis. Our results suggest interactions that could lead to the identification of a master regulatory scheme controlling osteoblast differentiation.
PPARgamma2 nuclear receptor controls multiple regulatory pathways of osteoblast differentiation from marrow mesenchymal stem cells.
Compound, Time
View SamplesHistone deacetylase 3 (HDAC3) is an epigenome-modifying enzyme that is required for normal mouse development and tissue-specific functions. In vitro, HDAC3 protein itself has minimal enzyme activity, but gains its histone deacetylation function from stable association with the conserved deacetylase activation domain (DAD) contained in nuclear receptor corepressors NCOR1 and SMRT. Here we show that HDAC3 enzyme activity is undetectable in mice bearing point mutations in the DAD of both NCOR1 and SMRT (NS-DADm), despite normal levels of HDAC3 protein. Local histone acetylation is increased, and genomic HDAC3 recruitment is reduced though not abrogated. Remarkably, the NS-DADm mice are born and live to adulthood, whereas genetic deletion of HDAC3 is embryonic lethal. These findings demonstrate that nuclear receptor corepressors are required for HDAC3 enzyme activity in vivo, and suggest that a deacetylase-independent function of HDAC3 may be required for life.
Nuclear receptor co-repressors are required for the histone-deacetylase activity of HDAC3 in vivo.
Specimen part, Time
View SamplesWe report the hepatic gene expression changes in NCOR and SMRT DADm-mutated mice.
Nuclear receptor co-repressors are required for the histone-deacetylase activity of HDAC3 in vivo.
Specimen part, Time
View SamplesTHO2 and HPR1 proteins were co-depleted from Drosophila S2 cells and their role in mRNA export analysed by comparing total RNA and cytoplasmic RNA
The superhelical TPR-repeat domain of O-linked GlcNAc transferase exhibits structural similarities to importin alpha.
Cell line
View SamplesThis SuperSeries is composed of the SubSeries listed below.
HNF6 and Rev-erbα integrate hepatic lipid metabolism by overlapping and distinct transcriptional mechanisms.
Sex, Age, Specimen part
View SamplesAppropriate nutrition during early development is essential for optimal bone mass accretion; however, linkage between early nutrition, childhood bone mass and prevention of bone loss later in life has not been extensively studied. In this report, we have demonstrated several fundamental issues in the field. 1) A significant prevention of ovariectomy (OVX) -induced bone loss from adult rats can occur with only 14 days consumption of a blueberry-containing diet immediately prior to puberty. 2) The molecular mechanisms underlying these effects involve increased myosin production and preserved a shuttle for transcription factors such as Runx2 from cytoplasm to nucleolus which stimulates osteoblast differentiation and reduces mesenchymal stromal cell senescence. 3) The effects of blueberry diet on preserving fidelity of osteoblast differentiation also overcome reduced osteoblast differentiation and activity due to OVX-induced degradation of collagen matrix.
Feeding blueberry diets in early life prevent senescence of osteoblasts and bone loss in ovariectomized adult female rats.
Sex, Specimen part
View Samples