Rett syndrome (RTT) is a severe neurodevelopmental disorder that is caused by mutations in the gene methyl-CpG-binding-protein-2 (MECP2). However, the molecular mechanism by which these mutations mediate the RTT neuropathology remains enigmatic. In this study, we stimulated MeCP2-null cortical neurons (in vitro) and brains (in vivo) of a RTT mouse model to explore the effect of the loss of MeCP2 function on the activity-dependent transcriptomes of the cortex and hippocampus, respectively, using RNA-seq. These analyses revealed that the loss of MeCP2 results in aberrant global pattern of gene expression, characterized predominantly by higher levels of expression of activity-dependent genes, and anomalous alternative splicing events, specifically in response to neuronal activity. Overall design: For in vitro experiments, RNA-seq was performed on MeCP2-null (MT) and wild-type (WT) neuron-enriched cortical cultures that were either treated (T) with KCl for 3hr or not treated (N), after 10 days in culture. For in vivo experiments, RNA-seq was performed on hippocampi of MeCP2-null (MT) and wild-type (WT) mice that were either treated with kainic acid for 40 or 68 minutes, or not treated.
Activity-dependent aberrations in gene expression and alternative splicing in a mouse model of Rett syndrome.
Specimen part, Treatment, Subject, Time
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Topology of the human and mouse m6A RNA methylomes revealed by m6A-seq.
Specimen part, Cell line, Treatment
View SamplesInactivation of the yeast IME4 gene, the yeast homologue of METTL3, was shown to result in the loss of m6A in mRNA of mutant cells grown in sporulation medium. We attempted to characterize the effects of ime4 deletion on gene expression under vegetative and meiosis-inducing conditions. The results show that in vegetatively-growing ime4-/- cells there is an increased expression of the RME1 gene (repressor of meiosis) which prevents precocious entry into the meiotic program. Mutant yeast cells showed reduced expression levels of genes involved in ribosome biogenesis and gene expression processes. Surprisingly, despite the fact that a diploid strain was analyzed, there was also a striking change in the expression level of haploid-specific genes, suggesting that RNA methylation may be used to enforce the sexual identity of diploid cells, required for the implementation of the gametogenesis program. Consistently, when cells were induced to undergo meiosis, ime4-/- diploids failed to undergo the meiotic divisions. Among the genes showing reduced expression in the mutant were IME1 and IME2, the two known inducers of meiosis. Thus, the yeast IME4 gene plays an important role in the regulation of the developmental switch from vegetative cells into gametogenesis.
Topology of the human and mouse m6A RNA methylomes revealed by m6A-seq.
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View SamplesWe developed a novel approach, m6A-seq, for high-resolution mapping of the transcriptome-wide m6A landscape, based on antibody-mediated capture followed by massively parallel sequencing. Overall design: Identification of m6A modified sequences in HepG2 cells. HepG2 cells were incubated with either IFNg (200ng/ml) or HGF/SF (10 ng/ml) over night. Stress effects were tested in HepG2 cells by either 30 minutes incubation at 43ºC (heat shock) or UV irradiation of 0.04 J/cm2 followed by 4 hours of recovery in normal growing conditions prior to harvesting using Trypsin.
Topology of the human and mouse m6A RNA methylomes revealed by m6A-seq.
Cell line, Treatment, Subject
View SamplesTo gain insight into possible processes that require m6A for their function, METTL3 was knocked down (KD) in HepG2 cells by siRNA transfections Overall design: Differential expression analysis of METTL3 KD versus mock-transfected HepG2 cells, in 2 biological replicates
Topology of the human and mouse m6A RNA methylomes revealed by m6A-seq.
Cell line, Subject
View SamplesAdenosine to Inosine (A-to-I) RNA editing is a site-specific modification of RNA transcripts, catalyzed by members of the ADAR (Adenosine Deaminase Acting on RNA) protein family. RNA editing occurs in human RNA in thousands of different sites. Some of the sites are located in protein-coding regions but the majority is found in non-coding regions, such as 3UTRs, 5UTRs and introns - mainly in Alu elements. While editing is found in all tissues, the highest levels of editing are found in the brain. It was shown that editing levels within protein-coding regions are increased during embryogenesis and after birth and that RNA editing is crucial for organism viability as well as for normal development. In this study we characterized the A-to-I RNA editing phenomenon during neuronal and spontaneous differentiation of human embryonic stem cells (hESCs). We identified high editing levels of Alu repetitive elements in hESCs and demonstrated a global decrease in editing levels of non-coding Alu sites when hESCs are differentiating, particularly into the neural lineage. Using RNA interference, we showed that the elevated editing levels of Alu elements in undifferentiated hESCs are highly dependent on ADAR1. DNA microarray analysis showed that ADAR1 knockdown has a global effect on gene expression in hESCs and leads to a significant increase in RNA expression levels of genes involved in differentiation and development processes, including neurogenesis. Taken together, our data suggest that A-to-I editing of Alu sequences plays a role in the regulation of hESC early differentiation decisions.
Alu sequences in undifferentiated human embryonic stem cells display high levels of A-to-I RNA editing.
Specimen part
View SamplesRationale. Lung inflammation in premature infants contributes to development of bronchopulmonary dysplasia (BPD), a chronic lung disease with long-term sequelae. Pilot studies administering budesonide suspended in surfactant have found reduced BPD without apparent adverse effects as occur with systemic dexamethasone therapy. Objectives. To determine effects of budesonide on differential genes expression in human fetal lung Overall design: Methods. We prepared RNA from 3 samples of human fetal lung at 23 weeks gestation before (preculture, PC) and after 4 days culture as explants with (Bud) or without (Way) budesonide (30 nM) and performed RNAseq on the 9 samples.
Antiinflammatory Effects of Budesonide in Human Fetal Lung.
Specimen part, Subject
View SamplesThe gain of Protocadherin LKC (PCDH24) expression in colon carcinoma cell line HCT116 has been shown to induce contact inhibition, thereby completely abolishing tumor formation in vivo. To clarify the molecular mechanism, we performed DNA microarray analysis and compared gene-expression pattern between control and PCDH24-expressing HCT116 cells. Approximately 2000 genes were apparently changed their expression. Further proteomics analysis using 2-DE/MS confirmed the dramatic changes and provided additional information. We were aware that these changes are quite similar to the changes observed in epithelial-mesenchymal transition (EMT), most drastic changes in development and cancer metastasis. We thus further analyzed these changes using specific antibodies, and found distinct difference between these two phenomena. Among the differences, nuclear translocation of catenin beta 1 (CTNNB1) was inhibited by PCDH24-expression, subsequently some of the downstream nodes were suppressed. Although contact inhibition and cancer metastasis are completely opposite aspect of the cells, we expect that the identified differences will be key nodes to understand the relationship. We also expect that the nodes will be a target to modulate tumors arising stem cell transplantation (SCT), as well as a therapeutic target for cancer metastasis.
PCDH24-induced contact inhibition involves downregulation of beta-catenin signaling.
No sample metadata fields
View SamplesTobacco use and alcohol consumption are two major contributing factors for head and neck squamous cell carcinoma (HNSCC) carcinogenesis. We combined the 4-nitroquinoline-1-oxide (4-NQO) oral carcinogenesis mouse model and the Meadows-Cook alcohol mouse models and performed next generation genome-wide RNA-sequencing of tongues. We determined changes in transcript levels in four groups: 4-NQO followed by ethanol treatment (4-NQO/EtOH), 4-NQO followed by normal drinking water (4-NQO/Untr.), vehicle control followed by ethanol treatment (V.C./EtOH), and vehicle control followed by normal drinking water (V.C./Untr.). We found that the 494 gene transcripts were significantly changed (at least a 2-fold change where p<0.05) in the V.C./EtOH group compared to the V.C./Untr. group. The 4-NQO/Untr. group had 1,808 transcripts significantly changed compared to the V.C./Untr group, while the 4-NQO/EtOH group had 3,606 significantly changed transcripts as compared to the V.C/Untr. group. This study is the first to show that 4-NQO followed by ethanol cause the largest number of changes in transcript levels in the tongue. Overall design: High-throughput Illumina HiSeq2000 Deep Sequencing results were compared to the mm9 mouse reference genome. Enrichment levels were determined using the Cufflinks software using the unit of fragments per kilobase per million reads (FPKM) model. n=3 for each treatment group.
Identification of Ethanol and 4-Nitroquinoline-1-Oxide Induced Epigenetic and Oxidative Stress Markers During Oral Cavity Carcinogenesis.
No sample metadata fields
View SamplesHigh fat diets are known to be a risk factor for prostate cancer. In this study, we investigated the effect of high fat diet on mouse prostate gene expression. C57BL/6J mice were fed either a control or high fat diet for 12 weeks. Microarray analyses were performed on mouse ventral prostate (VP) and dorsolateral prostate (DLP), followed by canonical pathway analysis and regulatory network identification. mRNA changes were confirmed by real time PCR. Approximately 2,125, and 1,194 genes responded significantly to the high fat diet in VP, DLP, respectively. Pathways and networks related to oxidative stress, glutathione metabolism, NRF-mediated oxidative stress response and NF-kappaB were all differentially regulated by high fat diet. GPx3 mRNA levels were decreased by approximately 2-fold by high fat diet in all 3 prostate lobes. In human non-transformed prostate cells (PrSC, PrEC and BPH-1), cholesterol loading decreased GPx3 expression, and increased H2O2 levels of culture medium. Troglitazone increased GPx3 expression in 3 normal prostate cells, and decreased H2O2 levels. In addition, troglitazone attenuated cholesterol-induced H2O2 increase. Tissue from prostate cancer biopsies had decreased GPx3 mRNA and its level was inversely related to the Gleason score.
High fat diet reduces the expression of glutathione peroxidase 3 in mouse prostate.
No sample metadata fields
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