The goal of this experiment was to define gene expression patterns of two mouse retinal neuron subsets that express the Thy1-mitoCFP-P (MP) transgene.
Neurod6 expression defines new retinal amacrine cell subtypes and regulates their fate.
Specimen part
View SamplesAutism spectrum disorder (ASD) is a common, highly heritable neuro-developmental condition characterized by marked genetic heterogeneity. Thus, a fundamental question is whether autism represents an etiologically heterogeneous disorder in which the myriad genetic or environmental risk factors perturb common underlying molecular pathways in the brain. Here, we demonstrate consistent differences in transcriptome organization between autistic and normal brain by gene co-expression network analysis. Remarkably, regional patterns of gene expression that typically distinguish frontal and temporal cortex are significantly attenuated in the ASD brain, suggesting abnormalities in cortical patterning. We further identify discrete modules of co-expressed genes associated with autism: a neuronal module enriched for known autism susceptibility genes, including the neuronal specific splicing factor A2BP1/FOX1, and a module enriched for immune genes and glial markers. Using high-throughput RNA-sequencing we demonstrate dysregulated splicing of A2BP1-dependent alternative exons in ASD brain. Moreover, using a published autism GWAS dataset, we show that the neuronal module is enriched for genetically associated variants, providing independent support for the causal involvement of these genes in autism. In contrast, the immune-glial module showed no enrichment for autism GWAS signals, indicating a non-genetic etiology for this process. Collectively, our results provide strong evidence for convergent molecular abnormalities in ASD, and implicate transcriptional and splicing dysregulation as underlying mechanisms of neuronal dysfunction in this disorder.
Transcriptomic analysis of autistic brain reveals convergent molecular pathology.
Disease
View SamplesAutism spectrum disorder (ASD) is a common, highly heritable neurodevelopmental condition characterized by marked genetic heterogeneity. Thus, a fundamental question is whether autism represents an aetiologically heterogeneous disorder in which the myriad genetic or environmental risk factors perturb common underlying molecular pathways in the brain. Here, we demonstrate consistent differences in transcriptome organization between autistic and normal brain by gene co-expression network analysis. Remarkably, regional patterns of gene expression that typically distinguish frontal and temporal cortex are significantly attenuated in the ASD brain, suggesting abnormalities in cortical patterning. We further identify discrete modules of co-expressed genes associated with autism: a neuronal module enriched for known autism susceptibility genes, including the neuronal specific splicing factor A2BP1 (also known as FOX1), and a module enriched for immune genes and glial markers. Using high-throughput RNA sequencing we demonstrate dysregulated splicing of A2BP1-dependent alternative exons in the ASD brain. Moreover, using a published autism genome-wide association study (GWAS) data set, we show that the neuronal module is enriched for genetically associated variants, providing independent support for the causal involvement of these genes in autism. In contrast, the immune-glial module showed no enrichment for autism GWAS signals, indicating a non-genetic aetiology for this process. Collectively, our results provide strong evidence for convergent molecular abnormalities in ASD, and implicate transcriptional and splicing dysregulation as underlying mechanisms of neuronal dysfunction in this disorder. Overall design: To identify potential A2BP1-dependent differential splicing events in ASD brain, we performed high-throughput RNA sequencing (RNA-Seq) on three autism samples with significant downregulation of A2BP1 (average fold change by quantitative RT-PCR = 5.9) and three control samples with average A2BP1 levels. The list of potential A2BP1-depending differential splicing events in ASD is given in the Supplementary file linked at the foot of this record.
Transcriptomic analysis of autistic brain reveals convergent molecular pathology.
No sample metadata fields
View SamplesLong interspersed elements 1 (LINE-1 or L1) are retrotransposons that dominate the mouse genomic landscape, and are expressed in Embryonic Stem Cells (ESCs), germ cells, and during early development. Based on clear precedents in plants and fission yeast, we investigated in this study a role for RNAi and other RNA degradation pathways in the regulation of L1 expression and mobilization. We uncovered the existence of novel small (s)RNAs that map to active L1 elements. Some of these sRNAs have characteristics of cognate short-interfering RNA populations, while others display length heterogeneity that evokes a biogenesis through a RNA surveillance pathway, in a Dicer-independent manner. We additionally found that genetic ablation of Dicer and the sRNA effector protein AGO2 has complex and profound consequences on L1 transcription and mobilization in ESCs, indicating that endogenous RNA interference (RNAi) pathway indeed maintain genomic integrity against L1 proliferation. Finally, we investigated the implication of L1 retrotransposition during ESC differentiation and propose that the mobilization of L1 elements in Dicer mutant ESCs could partially explain the inability of these cells to differentiate. Overall design: 2 samples examined: WT E14 and Dicer mutant mouse ESCs
RNAi-dependent and independent control of LINE1 accumulation and mobility in mouse embryonic stem cells.
Specimen part, Subject
View SamplesDNA methylation is an epigenetic mark that silences transposable elements (TEs) and repeats. Whereas the establishment and maintenance of DNA methylation are relatively well understood, little is known on their dynamics and biological relevance in plant and animal innate immunity. Here, we show that some TEs are demethylated and transcriptionally reactivated during antibacterial defense in Arabidopsis. This effect is concomitant with the down-regulation of key transcriptional gene silencing factors as well as an active demethylation process. DNA demethylation restricts multiplication and vascular propagation of the bacterial pathogen Pseudomonas syringae in leaves and, accordingly, some immune-response genes, containing repeats in their promoters, are negatively regulated by DNA methylation. This study provides evidence that DNA demethylation is part of a plant-induced immune response, potentially acting to prime transcriptional activation of some defense genes linked to Tes/repeats. We have monitored the transcript changes in Arabidopsis plants treated with a flagellin-derived peptide. Overall design: DNA methylation is closely related to 24nt sRNAs. This is why we sequenced small RNA population in our study. 5-week-old Col-0 leaf samples (treated with either water or flg22 at 1 ?M concentration for 6 h) and deep sequenced by Fasteris (Geneva) on the Illumina HiSeq 2000 platform.
Dynamics and biological relevance of DNA demethylation in Arabidopsis antibacterial defense.
Age, Specimen part, Treatment, Subject
View SamplesHerpesviruses are known to encode micro (mi)RNAs and to use them to regulate the expression of both viral and cellular genes. The genome of Kaposis sarcoma herpesvirus (KSHV) encodes a cluster of twelve miRNAs, which are abundantly expressed during both latency and lytic infection. Relatively few cellular targets of KSHV miRNAs are known. Here, we used a microarray expression profiling approach to analyze the transcriptome of both B lymphocytes and endothelial cells stably expressing KSHV miRNAs and monitor the changes induced by the presence of these miRNAs. We generated a list of potential cellular targets by looking for miRNA seed-match-containing transcripts that were significantly down regulated upon KSHV miRNAs expression. Interestingly, the overlap of putative targets identified in B lymphocytes and endothelial cells was minimal, suggesting a tissue-specific target-regulation by viral miRNAs. Among the putative targets, we identified caspase 3, a critical factor for the control of apoptosis, which we validated using luciferase reporter assays and western blotting. In functional assays we obtained further evidence that KSHV miRNAs indeed protect cells from apoptosis.
Kaposi's sarcoma herpesvirus microRNAs target caspase 3 and regulate apoptosis.
Cell line
View SamplesWe used the microarrays to obtain the cancerous signatures of T-cell, B-cell, erythroid and megakaryoblastic leukemias in mice.
Gene profiling of the erythro- and megakaryoblastic leukaemias induced by the Graffi murine retrovirus.
No sample metadata fields
View SamplesCF's physiopathology is poorly explained by the mutation alone. The oxydative stress could be a major factor of this illness . Study its impact on transcriptome's CF cell line could be ameliorate our understanding of the evolution of cystic fibrosis.
Oxidative stress modulates the expression of genes involved in cell survival in ΔF508 cystic fibrosis airway epithelial cells.
Cell line, Treatment
View SamplesThe primary objective of the study was to investigate the uncoupling protein-1 (UCP1) associated features of human epicardial adipose tissue (eAT) using next generation deep sequencing. In addition, paired mediastinal adipose tissue (mAT) and subcutaneous adipose tissue (sAT) samples colleced from patients undergoing cardic surgeries at our center were included in the study. Overall design: Paired biopsies of eAT, mAT and sAT obtained from cardiac surgery patients (n=10), with specific criteria of high- and low- expression of UCP1 in eAT, were subjected to RNA sequencing. While the primary objective was to compare high- vs. low UCP1 expression in eAT, our study design further allowed us to investigate depot- and disease specific transcriptomic shifts in these patients. Specifically, 10 patients provided 30 samples (n = 10 each for eAT, mAT and sAT) that could be compared based on depot specificity (n = 10), obesity (n = 5 lean, n = 5 obese) and coronary artery disease (CAD) (n = 6 CAD, 4 = Non-CAD).
UCP1 expression-associated gene signatures of human epicardial adipose tissue.
Disease, Disease stage, Subject
View SamplesA greater understanding of the molecular pathways that underpin the unique human hematopoietic stem and progenitor cell (HSPC) self-renewal program will improve strategies to expand these critical cell types for regenerative therapies. The post-transcriptional mechanisms guiding HSPC fate during ex vivo expansion have not been closely investigated. Using shRNA-mediated knockdown, we show that the RNA-binding protein (RBP) Musashi-2 (MSI2) is required for human HSPC self-renewal. Conversely, when overexpressed, MSI2 induces multiple pro-self-renewal phenotypes, including significant ex vivo expansion of short- and long-term repopulating cells through direct attenuation of aryl hydrocarbon receptor (AHR) signaling. Using a global analysis of MSI2-RNA interactions, we determined that MSI2 post-transcriptionally downregulates canonical AHR pathway components in cord blood HSPCs. Our study provides new mechanistic insight into RBP-controlled RNA networks that underlie the self-renewal process and provides evidence that manipulating such networks can provide a novel means to enhance the regenerative potential of human HSPCs expanded ex vivo. Overall design: 4 samples were used for RNA-seq (4 biological duplicate) including 2 sets of control samples (irrelvant shRNA kncok-downs)
Musashi-2 attenuates AHR signalling to expand human haematopoietic stem cells.
No sample metadata fields
View Samples