Ectopic expression of defined transcription factors can force direct cell fate conversion from one lineage to another in the absence of cell division. Several transcription factor cocktails have enabled successful reprogramming of various somatic cell types into induced neurons (iNs) of distinct neurotransmitter phenotype. However, the nature of the intermediate states that drive the reprogramming trajectory towards distinct iN types is largely unknown. Here we show that successful direct reprogramming of adult human brain pericytes into functional iNs by Ascl1 and Sox2 (AS) encompasses transient activation of a neural stem cell-like gene expression program that precedes bifurcation into distinct neuronal lineages. Intriguingly, during this transient state key signaling components relevant for neural induction and neural stem cell maintenance are regulated and functionally contribute to iN reprogramming and maturation. Thus, AS-mediated reprogramming into a broad spectrum of iN types involves the unfolding of a developmental program via neural stem cell-like intermediates. Overall design: Single-cell transcriptomes from multiple time points and conditions during direct conversion of human pericytes into induced pericytes through the overexpression of defined factors. Please note that [1] the *ctrl samples represent mock-transfected cells (analyzed along side of the transfected cells) [2] The cell type (for each sample) is provided as 'pericytes or pericyte-derived induced neuronal cells' (as they are in a differentiation continuum from pericytes to neurons due to the treatment protocol) with the combination of 'genotype/variation' and 'time point' information.
Direct pericyte-to-neuron reprogramming via unfolding of a neural stem cell-like program.
Specimen part, Subject
View SamplesThe PAR-domain basic leucine zipper (PAR bZip) transcription factors DBP, TEF, and HLF accumulate in a highly circadian manner in several peripheral tissues, including liver and kidney. Mice devoid of all three of these proteins are born at expected Mendelian ratios, but are epilepsy-prone, age at an accelerated rate and die prematurely. In the hope of identifying PAR bZip target genes whose altered expression might contribute to the high morbidity and mortality of PAR bZip triple knockout mice, we compared the liver and kidney transcriptomes of these animals to those of wild-type or heterozygous mutant mice. These experiments revealed that PAR bZip proteins control the expression of many enzymes and regulators involved in detoxification and drug metabolism, such as cytochrome P450 enzymes, carboxylesterases, and constitutive androstane receptor (CAR). Indeed, PAR bZip triple knockout mice are hypersensitive to xenobiotic compounds, and the deficiency in detoxification may contribute to their early ageing.
The circadian PAR-domain basic leucine zipper transcription factors DBP, TEF, and HLF modulate basal and inducible xenobiotic detoxification.
Sex, Specimen part, Time
View SamplesEvolutionary conserved biological rhythms play a fundamental role in the physiology and behavior of all light-sensitive organisms. Generation of rhythmic expression of clock-controlled genes is orchestrated by a molecular circadian clock constitutes by interconnected negative feedback loops of transcription factors. In this study, we want to characterize gene which also present a rhythmic translation through the characterization of genes with a rhythmic polysomal/total RNA ratio.
The circadian clock coordinates ribosome biogenesis.
Sex, Age, Specimen part, Disease, Time
View SamplesDiurnal oscillations of gene expression are a hallmark of rhythmic physiology across most living organisms. Such oscillations are controlled by the interplay between the circadian clock and feeding rhythms. While rhythmic mRNA accumulation has been extensively studied, comparatively less is known about their transcription and translation. Here, we quantified simultaneously temporal transcription, accumulation, and translation of mouse liver mRNAs under physiological light-dark conditions and ad libitum or night-restricted feeding in wild-type and Bmal1 deficient animals. We found that rhythmic transcription predominantly drives rhythmic mRNA accumulation and translation for a majority of genes. Comparison of wild-type and Bmal1 KO mice shows that circadian clock and feeding rhythms have broad impact on rhythmic genes expression, Bmal1 deletion having surprisingly more impact at the post-transcriptional level. Translation efficiency is differentially regulated during the diurnal cycle for genes with 5'-TOP sequences and for genes involved in mitochondrial activity and harboring a TISU motif. The increased translation efficiency of 5'-TOP and TISU genes is mainly driven by feeding rhythms but Bmal1 deletion impacts also amplitude and phase of translation, including TISU genes. Together this study emphasizes the complex interconnections between circadian and feeding rhythms at several steps ultimately determining rhythmic gene expression and translation. Overall design: RNA-Seq from total RNA of mouse liver during the dirunal cycle. Time-series mRNA profiles of wild type (WT) and Bmal -/- mice under ad libitum and night restriced feeding regimen were generated by deep sequencing.
Diurnal Oscillations in Liver Mass and Cell Size Accompany Ribosome Assembly Cycles.
Cell line, Subject
View SamplesMammalian gene expression displays widespread circadian oscillations. Rhythmic transcription underlies the core clock mechanism, but it cannot explain numerous observations made at the level of protein rhythmicity. We have used ribosome profiling in mouse liver to measure the translation of mRNAs into protein around-the-clock and at high temporal and nucleotide resolution. Transcriptome-wide, we discovered extensive rhythms in ribosome occupancy, and identified a core set of ˜150 mRNAs subject to particularly robust daily changes in translation efficiency. Cycling proteins produced from non-oscillating transcripts revealed thus far unknown rhythmic regulation associated with specific pathways (notably in iron metabolism, through the rhythmic translation of transcripts containing iron responsive elements), and indicated feedback to the rhythmic transcriptome through novel rhythmic transcription factors. Moreover, estimates of relative levels of core clock protein biosynthesis that we deduced from the data explained known features of the circadian clock better than did mRNA expression alone. Finally, we identified uORF translation as a novel regulatory mechanism within the clock circuitry. Consistent with the occurrence of translated uORFs in several core clock transcripts, loss-of-function of Denr, a known regulator of re-initiation after uORF usage and of ribosome recycling, led to circadian period shortening in cells. In summary, our data offer a framework for understanding the dynamics of translational regulation, circadian gene expression, and metabolic control in a solid mammalian organ. Overall design: A total of 48 mice were entrained under 12hours light:dark conditions for 2 weeks and also collected under 12hours light:dark. Mice were sacrificed every two hours during the 24 hours daily cycle. Two replicates per time point, each replicate is a pool of 2 livers.
Diurnal Oscillations in Liver Mass and Cell Size Accompany Ribosome Assembly Cycles.
No sample metadata fields
View SamplesThe cochlea possesses a robust circadian clock machinery that regulates auditory function. How the cochlear clock is influenced by the circadian system remains unknown. Here we show that cochlear rhythms are system-driven and require local Bmal1 as well as central input from the suprachiasmatic nuclei (SCN). SCN ablations disrupted the circadian expression of the core clock genes in the cochlea. Since the circadian secretion of glucocorticoids (GCs) is controlled by the SCN and that GCs are known to modulate auditory function, we assessed their influence on circadian gene expression. Removal of circulating GCs by adrenalectomy (ADX) did not have a major impact on core clock gene expression in the cochlea. Rather it abolished the transcription of clock-controlled genes involved in inflammation. ADX abolished the known differential auditory sensitivity to day and night noise trauma and prevented the induction of GABA-ergic and glutamate receptors mRNA transcripts. However, these improvements were unrelated to changes at the synaptic level suggesting other cochlear functions may be involved. Due to this circadian regulation of noise sensitivity by GCs, we evaluated the actions of the synthetic glucocorticoid dexamethasone (DEX) at different times of the day. DEX was effective in protecting from acute noise trauma only when administered during daytime, when circulating glucocorticoids are low, indicating that chronopharmacological approaches are important for obtaining optimal treatment strategies for hearing loss. GCs appear as a major regulator of the differential sensitivity to day or night noise trauma, a mechanism likely involving the circadian control of inflammatory responses. Overall design: Cochlear samples from sham operated or adrenalectomized (ADX) CBA/Sca mice were collected every 4th hour during a 24h period and subjected to RNAseq (n=3 per time point, corresponding to a total of 36 samples).
Circadian Regulation of Cochlear Sensitivity to Noise by Circulating Glucocorticoids.
Age, Specimen part, Cell line, Subject
View SamplesFor Samples 1-8 and 11-18: The innate immune sensor retinoic acid-inducible gene-I (RIG-I) detects double-stranded RNA derived from RNA viruses, and recent studies have demonstrated that RIG-I also plays a role in the antiviral response to DNA viruses. To identify the physiological RNA species that are recognized by RIG-I during HSV-1 infection, we purified the RNAs that co-immunoprecipitated with FLAG-tagged RIG-I in transfected human embryonic kidney (HEK) 293T cells that had been infected with a recombinant HSV-1 (hereafter referred to as HSV-1 mut) containing a mutation (K220A) in the viral serine/threonine protein kinase US3 that abolishes its catalytic activity, as the viral kinase is known to antagonize type-I IFN responses. As controls, RNA species bound to FLAG-RIG-I in uninfected cells and RNA bound to FLAG-GFP from both HSV-1 mut-infected and uninfected cells were also purified. RIG-I-bound RNA and total RNA extracted from uninfected and HSV-1 mut-infected cells were analyzed by RNAseq, and the resulting sequences were mapped to both the HSV-1F-strain and human genome (hg38). This analysis revealed that several human transcripts were highly enriched in the RIG-I-bound fraction from infected cells; in contrast, the enrichment of viral sequences was low. The cellular transcripts that were most abundant in the RIG-I fraction were predominantly non-coding RNAs from different subclasses, as well as some coding RNAs. For Samples 9 and 10: HSV-1 infection is known to induces changes in the transcriptional profile of the infected cell. To analyze global changes in RNA transcript levels in infected cells, total RNA was extracted from HEK 293T cells that were infected with wild-type (WT) HSV-1. For comparison, total RNA was extracted from HEK 293T cells that remained uninfected. Next, RNAseq analysis was performed. The resulting sequences were mapped to the human genome, and gene inductions were calculated and normalized to uninfected samples to determine changes in gene expression upon infection. Overall design: Cells, which were not infected or infected with either wildtype HSV-1 or mutated HSV-1 were either subjected to a pulldown isolating RLR/GFP associated RNA (8 samples) or the corresponding total RNA (8 samples) was extracted from the infected cells and sequenced. Additionally, non-transfected cells were infected and total RNA extracted and sequenced (2 samples)
Viral unmasking of cellular 5S rRNA pseudogene transcripts induces RIG-I-mediated immunity.
Specimen part, Cell line, Subject
View SamplesThe aim of this study was to identify candidate genes responsible for grain number per panicle between a pair of rice varieties (Pusa 1266 and Pusa Basmati 1) by combining QTL analysis with expression analysis. Microarray analysis of RNA extracted from the panicle primordia showed 2741 differentially expressed genes. The differentially expressed genes were shortened to 18 on the basis of their occurance in the QTL region (responsible for grain number regulation) detected in RIL population derived from Pusa 1266 and Pusa Basmati 1.
Identification of candidate genes for grain number in rice (Oryza sativa L.).
No sample metadata fields
View SamplesWe profiled the gene expression of 11 anaplastic thyroid carcinomas (ATC), 49 papillary thyroid carcinomas (PTC) and 45 normal thyroids (N)
A general method to derive robust organ-specific gene expression-based differentiation indices: application to thyroid cancer diagnostic.
Specimen part
View SamplesWe showed that a large number of genes and exons were deregulated in colorectal adenomas in comparison with colorectal normal mucosa.
A gene expression and pre-mRNA splicing signature that marks the adenoma-adenocarcinoma progression in colorectal cancer.
Specimen part
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