The adipocyte-derived hormone leptin maintains energy balance by acting on hypothalamic leptin receptors (Leprs) that trigger the signal transducer and activator of transcription 3 (Stat3). Although disruption of Lepr-Stat3 signaling promotes obesity in mice, other features of Lepr function, such as fertility, seem normal, pointing to the involvement of additional regulators. Here we show that the cyclic AMP responsive elementbinding protein-1 (Creb1)-regulated transcription coactivator-1 (Crtc1) is required for energy balance and reproductionCrtc1-/- mice are hyperphagic, obese and infertile. Hypothalamic Crtc1 was phosphorylated and inactive in leptin-deficient ob/ob mice; leptin administration increased amounts of dephosphorylated nuclear Crtc1. Dephosphorylated Crtc1 stimulated expression of the Cartpt and Kiss1 genes, which encode hypothalamic neuropeptides that mediate leptins effects on satiety and fertility. Crtc1 overexpression in hypothalamic cells increased Cartpt and Kiss1 gene expression, whereas Crtc1 depletion decreased it. Indeed, leptin enhanced Crtc1 activity over the Cartpt and Kiss1 promoters in cells overexpressing Lepr and these effects were disrupted by expression of a dominant-negative Creb1 polypeptide. As leptin administration increased recruitment of hypothalamic Crtc1 to Cartpt and Kiss1 promoters, our results indicate that the Creb1-Crtc1 pathway mediates the central effects of hormones and nutrients on energy balance and fertility.
The Creb1 coactivator Crtc1 is required for energy balance and fertility.
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View SamplesThree cell types, intermediolateral column motoneurons, medial motoneurons, and lateral motoneurons were isolated from a single adult spinal cord using laser capture microscopy. Four hundred captures were collected for each cell type. For a given cell type, RNA was extracted from the 400 captures using an Arcturus picopure kit. RNA was split in half and two targets were produced using a double amplification protocol. Each target was hybridized to Affymetrix chips and signals were normalized with R-pack. Inverse logs are provided. Five animals were used in these experiments, and all three cell types were collected from each animal. Thus, for each cell type, there are five biological replicates, and for each biological replicate there are two technical replicates. In all thirty chips were analyzed. Techinical replicates are indicated as Set 1 and Set 2. Animal numbers are indicated by Pair1 through Pair 5.
Divergence between motoneurons: gene expression profiling provides a molecular characterization of functionally discrete somatic and autonomic motoneurons.
Specimen part
View SamplesMagnaporthe oryzae causes rice blast, the most devastating foliar fungal disease of cultivated rice. During disease development the fungus simultaneously maintains both biotrophic and necrotrophic growth corresponding to a hemi-biotrophic life style. The ability of M. oryzae to also colonize roots and subsequently develop blast symptoms on aerial tissue has been recognized. The fungal root infection strategy and the respective host responses are currently unknown. Global temporal expression analysis suggested a purely biotrophic infection process reflected by the rapid induction of defense response-associated genes at the early stage of root invasion and subsequent repression coinciding with the onset of intracellular fungal growth. The same group of down-regulated defense genes was increasingly induced upon leaf infection by M. oryzae where symptom development occurs shortly post tissue penetration. Our molecular analysis therefore demonstrates the existence of fundamentally different tissue-specific fungal infection strategies and provides the basis for enhancing our understanding of the pathogen life style.
Tissue-adapted invasion strategies of the rice blast fungus Magnaporthe oryzae.
Specimen part
View SamplesOne of our new major finding among the genes that contributes to MS susceptibility is ICSBP1. The so called disease modifying therapies like interferon-beta (IFN-), possibly acting on the peripheral T-cells, reduce the disease activity and the clinical progression, with a MRI-detectable effect in preventing lesion burden and cerebral atrophy development in RR-MS. It suggests a critical role of peripheral blood mononuclear cells (PBMCs) immune response and modulation in developing inflammation in the brain. We tested the hypothesis that the genetic effect of the susceptible allele ICSBP1 can impact the gene expression profile of molecules belonging to the interferon pathway. We therefore interrogated the PBMC for changes in gene expression profile. We correlate those changes with the minor allele frequency for ICSBP1, performing independent quantitative trait analysis for each treatment category. Expression Quantitative Trait Loci Association with a p value < 0.05 have been used in follow up analysis. The regression coefficient of the Quantitative trait association represents the degree of correlation between the gene expression for each interrogated target gene and the minor allele frequency of the SNP for our gene of interest. This coefficient has been used as input in the subsequent Gene Set Enrichment Analysis performed in a pre-ranked approach. The resulting GSEA-SNP method rests on the assumption that SNPs underlying a disease phenotype might affect genes constituting a signaling pathway or genes with a common regulation. Therefore, GSEA-SNP can facilitate the identification of pathways or of underlying biological mechanisms.
Meta-analysis of genome scans and replication identify CD6, IRF8 and TNFRSF1A as new multiple sclerosis susceptibility loci.
Specimen part
View SamplesDrosophila S2 cells were treated with Heat-shock protein 90 (Hsp90) inhibitor radicicol for 15min, 30min and 1h. Poly(A) RNA was isolated and sequenced. Overall design: Kinetics of transcriptional response to Hsp90 inhibition
Hsp90 globally targets paused RNA polymerase to regulate gene expression in response to environmental stimuli.
Specimen part, Cell line, Subject, Time
View SamplesG protein alpha q and 11 are mutated in 80% of uveal melanoma. We observed that treatment with the BRD4 inhibitor JQ1 resulted in different phenotypic responses in G-protein mutant uveal melanoma cell lines and wild type uveal melanoma cell lines.
BRD4-targeted therapy induces Myc-independent cytotoxicity in Gnaq/11-mutatant uveal melanoma cells.
Cell line, Treatment
View SamplesNeural precursor cells (NPCs) are multipotent cells that can generate neurons, astrocytes, and oligodendrocytes in the mammalian central nervous system. Although Zbtb20 was expressed in NPCs, its functions in neural development are not fully understood. We performed microarray analysis to examine changes in gene expression between control and Zbtb20-overexpressed NPCs.
Zbtb20 promotes astrocytogenesis during neocortical development.
Specimen part
View SamplesThe Photo-Activatable Ribonucleoside-enhanced CrossLinking and ImmunoPrecipitation (PAR-CLIP) method was recently developed for global identification of RNAs interacting with proteins. The strength of this versatile method results from induction of specific T to C transitions at sites of interaction. However, current analytical tools do not distinguish between non-experimentally and experimentally induced transitions. Furthermore, geometric properties at potential binding sites are not taken into account. To surmount these shortcomings, we developed a two-step algorithm consisting of a non-parametric two-component mixture model and a wavelet-based peak calling procedure. Our algorithm can reduce the number of false positives up to 24% thereby identifying high confidence interaction sites. We successfully employed this approach in conjunction with a modified PAR-CLIP protocol to study the functional role of nuclear MOV10, a putative RNA helicase interacting with Argonaute2 and Polycomb. Our method, available as the R package wavClusteR, is generally applicable to any substitution-based inference problem in genomics. Overall design: The data comprises one MOV10 PAR-CLIP data file and one nuclear RNA-seq file
Mixture models and wavelet transforms reveal high confidence RNA-protein interaction sites in MOV10 PAR-CLIP data.
Cell line, Subject
View SamplesElevated levels of androgen receptor (AR) in prostate cancer confer resistance to current antiandrogens and play a causal role in disease progression due to persistent target gene activation. Through pharmacologic and genetic approaches, we show that half of all direct AR target genes, including TMPRSS2, the primary driver of ETS fusion transcripts in 70 percent of human prostate cancers, require histone deacetylase (HDAC) activity for transcriptional activation by AR. Surprisingly, the HDAC3-NCoR complex, which typically functions to repress gene expression by nuclear receptors, is required for AR target gene activation. Prostate cancer cells treated with HDAC inhibitors have reduced AR protein levels, but we show that the mechanism of blockade of AR activity is through failure to assemble a coactivator/RNA polymerase II complex after AR binds to the enhancers of target genes. Failed complex assembly is associated with a phase shift in the cyclical wave of AR recruitment that typically occurs in response to ligand treatment. HDAC inhibitors retain the ability to block AR activity in hormone refractory prostate cancer models and therefore merit clinical investigation in this setting. HDAC-regulated AR target genes defined here can serve as biomarkers to ensure sufficient levels of HDAC inhibition.
Histone deacetylases are required for androgen receptor function in hormone-sensitive and castrate-resistant prostate cancer.
No sample metadata fields
View SamplesElevated levels of androgen receptor (AR) in prostate cancer confer resistance to current antiandrogens and play a causal role in disease progression due to persistent target gene activation. Through pharmacologic and genetic approaches, we show that half of all direct AR target genes, including TMPRSS2, the primary driver of ETS fusion transcripts in 70 percent of human prostate cancers, require histone deacetylase (HDAC) activity for transcriptional activation by AR. Surprisingly, the HDAC3-NCoR complex, which typically functions to repress gene expression by nuclear receptors, is required for AR target gene activation. Prostate cancer cells treated with HDAC inhibitors have reduced AR protein levels, but we show that the mechanism of blockade of AR activity is through failure to assemble a coactivator/RNA polymerase II complex after AR binds to the enhancers of target genes. Failed complex assembly is associated with a phase shift in the cyclical wave of AR recruitment that typically occurs in response to ligand treatment. HDAC inhibitors retain the ability to block AR activity in hormone refractory prostate cancer models and therefore merit clinical investigation in this setting. HDAC-regulated AR target genes defined here can serve as biomarkers to ensure sufficient levels of HDAC inhibition.
Histone deacetylases are required for androgen receptor function in hormone-sensitive and castrate-resistant prostate cancer.
No sample metadata fields
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