Increasing evidence supports a role for altered gene expression in mediating the lasting effects of cocaine on the brain, and recent work has demonstrated the involvement of chromatin modifications in these alterations. However, all such studies to date have been restricted by their reliance on microarray technologies which have intrinsic limitations. Here, we used advanced sequencing methods, RNA-seq and ChIP-seq, to obtain an unprecedented view of cocaine-induced changes in gene expression and associated adaptations in numerous modes of chromatin regulation in the nucleus accumbens, a key brain reward region. We identify unique combinations of chromatin changes, or signatures, that accompany cocaine’s regulation of gene expression, including the dramatic involvement of pre-mRNA alternative splicing in cocaine action. Together, this delineation of the cocaine-induced epigenome in the nucleus accumbens reveals several novel modes of drug regulation, thereby providing new insight into the biological basis of cocaine addiction. More broadly, the combinatorial chromatin and transcriptional approaches that we describe serve as an important resource for the field, as they can be applied to other systems to reveal novel transcriptional and epigenetic mechanisms of neuronal regulation. Overall design: Total RNA was isolated from mouse nucleus accumbens 24 hr after 7 day daily cocaine or saline control ip injection for mRNA sequencing by following illumina RNA seq kit protocol. Another batch of acute cocaine RNA-seq was performed using the same parameters except the treatment group was given 6 days of saline injection followed by 1 day of cocaine injection. The acute cocaine batch serves as control experiments.
Chronic cocaine-regulated epigenomic changes in mouse nucleus accumbens.
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View SamplesWe examine the role of Klf6 in oligodendrocyte progenitor cells and determine that Klf6 acts as a gp130-sensitive transactivator of the nuclear import factor importin-a5 (Impa5), a key controller of nuclear trafficking in oligodendrocytes. Overall design: Examination of expression profiles of 2 different cell stages exposed to siRNA vs. control
The Transcriptional Activator Krüppel-like Factor-6 Is Required for CNS Myelination.
Specimen part, Cell line, Subject
View SamplesHere we show that Tet1 is down-regulated in mouse nucleus accumbens (NAc), a key brain reward structure, by repeated cocaine administration which enhances behavioral responses to cocaine. Through genome-wide 5hmC profiling, we identified 5hmC changes selectively clustered in both enhancer and coding regions of genes with several annotated neural functions. By coupling with mRNA sequencing, we found cocaine-induced alterations in 5hmC correlate positively with alternative splicing. We also demonstrated that 5hmC alteration at certain genes lasts up to a month after cocaine exposure. Overall design: RNA Nac samples were collected at various time points after 7 daily cocaoine ip administration for 5hmC and transcriptome analysis
Role of Tet1 and 5-hydroxymethylcytosine in cocaine action.
No sample metadata fields
View SamplesWe apply the cellular reprogramming experimental paradigm to two disorders caused by symmetrical copy number variations (CNV) of 7q11.23 and displaying a striking combination of shared as well as symmetrically opposite phenotypes: Williams Beuren syndrome (WBS) and 7q microduplication syndrome (7dupASD). Through a uniquely large and informative cohort of transgene-free patient-derived induced pluripotent stem cells (iPSC), along with their differentiated derivatives, we find that 7q11.23 CNV disrupt transcriptional circuits in disease-relevant pathways already at the pluripotent state. These alterations are then selectively amplified upon differentiation into disease-relevant lineages, thereby establishing the value of large iPSC cohorts in the elucidation of disease-relevant developmental pathways. In addition, we functionally define the quota of transcriptional dysregulation specifically caused by dosage imbalances in GTF2I (also known as TFII-I), a transcription factor in 7q11.23 thought to play a critical role in the two conditions, which we found associated to key repressive chromatin modifiers. Finally, we created an open-access web-based platform (accessible at http://bio.ieo.eu/wbs/ ) to make accessible our multi-layered datasets and integrate contributions by the entire community working on the molecular dissection of the 7q11.23 syndromes. Overall design: We reprogrammed skin fibroblasts from patients harbouring a 7q11.23 hemi-deletion (WBS, 4 patients; +1 atypical deletion, AtWBS) or microduplication (7dupASD; 2 patients), as well as from one unaffected relative and two unrelated controls, using integration-free mRNA-reprogramming, leading to the establishment of a total of 27 characterized iPSC clones. We profiled these by RNAseq (either polyA or ribo-zero). To isolate the contribution of GTF2I to the transcriptional dysregulation, we created stable lines expressing a short hairpin against GTF2I from a representative subset of these iPSC clones, and profiled by RNAseq 7 such lines along with their respective scramble controls. Finally, we also profiled by RNAseq mesenchymal stem cells (MSC) derived from a representative subset of the lines.
RNAontheBENCH: computational and empirical resources for benchmarking RNAseq quantification and differential expression methods.
No sample metadata fields
View SamplesRett syndrome is caused by mutations in the gene encoding methyl-CpG binding protein 2 (MECP2), an epigenetic regulator of mRNA transcription. Here we report a test of the hypothesis of shared pathophysiology of Rett syndrome and fragile X, another monogenic cause of autism and intellectual disability. In fragile X, the loss of the mRNA translational repressor FMRP leads to exaggerated protein synthesis downstream of metabotropic glutamate receptor 5 (mGluR5). We found that mGluR5- and protein synthesis-dependent synaptic plasticity is similarly altered in area CA1 of Mecp2 KO mice. CA1 pyramidal cell-type-specific, genome-wide profiling of ribosome-bound mRNAs was performed in wild-type and Mecp2 KO hippocampal CA1 neurons to reveal the MeCP2-regulated 'translatome'. We found significant overlap between ribosome-bound transcripts overexpressed in the Mecp2 KO and FMRP mRNA targets. These tended to encode long genes that are functionally related to either cytoskeleton organization or the development of neuronal connectivity. In the Fmr1 KO mouse, chronic treatment with mGluR5 negative allosteric modulators (NAMs) has been shown to ameliorate many mutant phenotypes by correcting excessive protein synthesis. In the Mecp2 KO mice we found that mGluR5 NAM treatment significantly reduces the level of overexpressed ribosome-associated transcripts, particularly those that are also FMRP targets. Some Rett phenotypes were also ameliorated by treatment, most notably hippocampal cell size and life span. Together, these results suggest a potential mechanistic link between MeCP2-mediated transcription regulation and mGluR5/FMRP-mediated protein translation regulation through co-regulation of a subset of genes relevant to synaptic functions. Overall design: TRAP-seq analysis of the effect of negative modulator of mGluR5 on the CA1 neurons (marked by Cck-EGFP-L10a) of a mouse model of Rett syndrome
Negative Allosteric Modulation of mGluR5 Partially Corrects Pathophysiology in a Mouse Model of Rett Syndrome.
Specimen part, Cell line, Treatment, Subject
View SamplesThe 14-week experiment included three groups: 1) the Acute Cpn group, with one C. pneumoniae inoculation at the age of 9 wks; 2) the Chronic Cpn group, with three C. pneumoniae inoculations at the age of 9, 11, and 13 wks; and 3) the control group, with three SPG inoculations at the age of 9, 11, and 13 wks. The mice were sacrificed at the age of 14 wks. The 24-week experiment included four groups: 1) the recurrent A. actinomycetemcomitans infection group, with ten A. actinomycetemcomitans inoculations once a week from the age of 14 to 23 wks; 2) the chronic C. pneumoniae infection group, with three C. pneumoniae inoculations at the age of 9, 11, and 13 wks; 3) the combined chronic C. pneumoniae and recurrent A. actinomycetemcomitans infection group, with three C. pneumoniae inoculations at the age of 9, 11, and 13 wks, and ten A. actinomycetemcomitans inoculations once a week from the age of 14 to 23 wks; and 4) the control group, with three SPG inoculations at the age of 9, 11, and 13 wks, and ten 0.9% NaCl inoculations once a week from the age of 14 to 23 wks. The mice were sacrificed at the age of 24 wks.Epididymal and inguinal AT gene expression was analyzed using an Illumina Mouse WG-6 v2.0 platform.
The effect of proatherogenic pathogens on adipose tissue transcriptome and fatty acid distribution in apolipoprotein E-deficient mice.
Sex, Age, Specimen part
View SamplesPheochromocytomas (PCC) are mostly benign tumors, amenable to complete surgical resection. However, 1017% of cases can become malignant, and once metastasized, there is no curative treatment for this disease. Given the need to identify effective therapeutic approaches for PCC, we evaluated the antitumor potential of the dual PI3K/mTOR inhibitor BEZ235 against these tumors. We employed an in vivo model of endogenous PCCs (MENX mutant rats), which closely recapitulate the human tumors. Mutant rats with PCCs were treated with 2 doses of BEZ235 (20 and 30 mg/kg), or with placebo, for 2 weeks. Treatment with BEZ235 induced cytostatic and cytotoxic effects on rat PCCs, which could be appreciated by both staining the tumors ex vivo with appropriate markers, and non-invasively by functional imaging (diffusion weighted-DW-MRI) in vivo.
Targeting PI3K/mTOR signaling exerts potent antitumor activity in pheochromocytoma in vivo.
Sex, Age, Specimen part, Treatment
View SamplesEfforts to unravel the mechanisms underlying taste sensation (gustation) have largely focused on rodents. The first comprehensive database of gene expression in primate (Macaca fascicularis) taste buds is presented. This database provides a foundation for further studies in diverse aspects of taste biology. A taste bud gene expression database was generated using laser capture microdissection (LCM) of tissue freeze medium OTC embedded macaque tongue tissue blocks. We collected fungiform (FG) taste buds at the front of the tongue, circumvallate (CV) taste buds at the back of the tongue, as well as non-gustatory lingual epithelium (LE). Gene expression was also analyzed in the top and bottom portions of CV taste buds collected using LCM. Samples were collected from 10 animals - 7 female, 3 male.
Genome-wide analysis of gene expression in primate taste buds reveals links to diverse processes.
Sex, Age, Specimen part
View SamplesMalignant gliomas constitute one of the most significant areas of unmet medical need, due to the invariable failure of surgical eradication and their marked molecular heterogeneity. Accumulating evidence has revealed a critical contribution by the Polycomb axis of epigenetic repression. However, a coherent understanding of the regulatory networks affected by Polycomb during gliomagenesis is still lacking. Here we integrate transcriptomic and epigenomic analyses to define Polycomb-dependent networks that promote gliomagenesis, validating them both in two independent mouse models and in a large cohort of human samples. We found that Polycomb dysregulation in gliomagenesis affects transcriptional networks associated to invasiveness and de-differentiation. The dissection of these networks uncovers Zfp423 as a crtitical Polycomb-dependent transcription factor whose silencing negatively impacts survival. The anti-gliomagenic activity of Zfp423 requires interaction with the SMAD proteins within the BMP signaling pathway, pointing to a novel synergic circuit through which Polycomb inhibits BMP signaling. Overall design: Transcriptomic analysis of two different stages of gliomagenesis
Polycomb dysregulation in gliomagenesis targets a Zfp423-dependent differentiation network.
Specimen part, Cell line, Subject
View SamplesAnalysis of epigenetic changes of pericytes after ischemia-reperfusion renal injury. The hypothesis tested in the present study was that epigenetic change develope in pericytes after acute kidney injury. This phenotype change would cause pericyte to be more proliferative and profibrotic. Results provide important information of the epigenetic change of pericytes, such as specific mechano-responsive genes, up-regulated specific proliferative and profibrotic functions.
Methylation in pericytes after acute injury promotes chronic kidney disease.
Specimen part
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