The LXR-regulated E3 ubiquitin ligase IDOL controls LDLR receptor stability independent of SREBP and PCSK9, but its relevance to plasma lipid levels is unknown. Here we demonstrate that the effects of the LXRIDOL axis are both tissue- and species-specific. In mice, LXR agonist induces Idol expression in peripheral tissues but not in liver, and does not change plasma LDL levels. Accordingly, Idol-deficient mice exhibit elevated LDLR protein levels in peripheral tissues but not in the liver and have minimal change in plasma LDL levels. By contrast, LXR activation in cynomolgus monkeys induces hepatic IDOL expression, reduces LDLR protein, and raises plasma LDL levels. Knockdown of IDOL in monkeys with an antisense oligonucleotide blunts the effect of LXR agonist on LDL levels. These results implicate IDOL as a modulator of plasma lipid levels in primates and support further investigation into IDOL inhibition as a strategy for LDL lowering in humans.
The LXR-Idol axis differentially regulates plasma LDL levels in primates and mice.
Specimen part, Treatment
View SamplesCraniosynostosis (CS) is the congenital premature fusion of one or more cranial sutures and represents the more prevalent craniofacial malformation in humans, with an overall incidence of 1 out of 2000-3000 live births. Non-syndromic craniosynostoses (NSC) are believed to be multifactorial disorders, with a strong genetic component, due to possible genegene or geneenvironment interactions that remain to be clearly identified. In this study we delved into the molecular signaling acting in calvarial tissue and cells from patients affected by nonsynodromic midline craniosynostosis, using a comparative analysis between fused and unfused sutures of each affected individuals. Using comparative microarray tissue gene expression profiling we have identified a subset of genes involved in the structure and function of the primary cilium, including the Bardet-Biedl syndrome 9 (BBS9) gene, which was recently associated to sagittal synostosis in a GWAS study. We therefore characterized BBS9 expression and cilium-related signaling in cells isolated from patients calvarial bone.
BBS9 gene in nonsyndromic craniosynostosis: Role of the primary cilium in the aberrant ossification of the suture osteogenic niche.
Sex, Specimen part, Disease
View SamplesPolycomb Repressive Complex 2 (PRC2) catalyzes histone H3 lysine 27 tri-methylation, an epigenetic modification associated with gene repression. H3K27me3 is enriched at the promoters of a large cohort of developmental genes in embryonic stem cells (ESCs). Loss of H3K27me3 leads to a failure of ESCs to properly differentiate, which presents a major roadblock for dissecting the precise roles of PRC2 activity during lineage commitment. While recent studies suggest that loss of H3K27me3 leads to changes in DNA methylation in ESCs, how these two pathways coordinate to regulate gene expression programs during lineage commitment is poorly understood. Here, we analyzed gene expression and DNA methylation levels in several PRC2 mutant ESC lines that maintain varying levels of H3K27me3. We found that maintenance of intermediate levels of H3K27me3 allowed for proper temporal activation of lineage genes during directed differentiation of ESCs to spinal motor neurons (SMNs). However, genes that function to specify other lineages failed to be repressed, suggesting that PRC2 activity is necessary for lineage fidelity. We also found that H3K27me3 is antagonistic to DNA methylation in cis. Furthermore, loss of H3K27me3 leads to a gain in promoter DNA methylation in developmental genes in ESCs and in lineage genes during differentiation. Thus, our data suggest a role for PRC2 in coordinating dynamic gene repression while protecting against inappropriate promoter DNA methylation during differentiation. Overall design: Embryonic Stem Cell (ESC) lines mutant for PRC2 core components Suz12 (Suz12GT and Suz12delta) and Eed (Eednull) were subjected to in vitro directed differentiation down the spinal motor neuron lineage. ESCs and day 5 differentiated cells from the three mutant lines and wild-type were used for RNA-seq.
Polycomb Repressive Complex 2 regulates lineage fidelity during embryonic stem cell differentiation.
No sample metadata fields
View SamplesHost cells harbor various intrinsic mechanisms to restrict viral infections as a first line of antiviral defense. Viruses have evolved various countermeasures against these antiviral mechanisms. Here we show that N-Myc Downstream-Reguated Gene 1 (NDRG1) limits productive HCV infection by inhibiting viral assembly. Interestingly, HCV infection down-regulates NDRG1 protein and mRNA expression. Loss of NDRG1 increases the size and number of lipid droplets, which are the sites of HCV assembly. HCV suppresses NDRG1 expression by up-regulating MYC, which directly inhibits the transcription of NDRG1.
N-Myc Downstream-Regulated Gene 1 Restricts Hepatitis C Virus Propagation by Regulating Lipid Droplet Biogenesis and Viral Assembly.
Cell line, Treatment
View SamplesIdentification of genes regulated by GATA-1 independent of the cofactor FOG-1.
Friend of GATA-1-independent transcriptional repression: a novel mode of GATA-1 function.
No sample metadata fields
View SamplesPURPOSE
Gene expression profiling reveals novel biomarkers in nonsmall cell lung cancer.
Specimen part, Disease
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Developmentally regulated higher-order chromatin interactions orchestrate B cell fate commitment.
Specimen part
View SamplesESCs and NPCs are two setm cell types which rely on expression of the transcription factor Sox2. We profilled gene expression in ESCs and NPCs to correlate genome-wide Sox2 ChIP-Seq data in these cells with expression of putative targets
SOX2 co-occupies distal enhancer elements with distinct POU factors in ESCs and NPCs to specify cell state.
No sample metadata fields
View SamplesSON is a large Ser/Arg (SR)-related protein localized in nuclear speckles. SON siRNA causes defects in mitotic progression and genome instability. We used microarrays to detail the pattern of gene expression after SON knockdown.
SON controls cell-cycle progression by coordinated regulation of RNA splicing.
Specimen part
View SamplesOrganization of the genome in 3D nuclear-space is known to play a crucial role in regulation of gene expression. However, the chromatin architecture that impinges on the B cell-fate choice of multi-potent progenitors remains unclear. By employing in situ Hi-C, we have identified distinct sets of genomic loci that undergo a developmental switch between permissive and repressive compartments during B-cell fate commitment. Intriguingly, we show that topologically associating domains (TADs) represent co-regulated subunits of chromatin and display considerable structural alterations as a result of changes in the cis-regulatory interaction landscape. The extensive rewiring of cis-regulatory interactions is closely associated with differential gene expression programs. Further, we demonstrate the regulatory role of Ebf1 and its downstream factor, Pax5, in chromatin reorganization and transcription regulation. Together, our studies reveal that alterations in promoter and cis-regulatory interactions underlie changes in higher-order chromatin architecture, which in turn determines cell-identity and cell-type specific gene expression patterns.
Developmentally regulated higher-order chromatin interactions orchestrate B cell fate commitment.
Specimen part
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