Transriptional profiling of white adipose tissue extracted from obese mice.
Loss of mitochondrial protease OMA1 alters processing of the GTPase OPA1 and causes obesity and defective thermogenesis in mice.
Age, Specimen part
View SamplesHeart failure (HF) is a major health and economic burden in developed countries. It has been proposed that the pathogenesis of HF may involve the action of mitochondria. Here we evaluate three different models of HF: tachycardiomyopathy, HF with preserved left ventricular (LV) ejection fraction, and LV myocardial ischemia and hypertrophy. Regardless of whether LVEF is preserved or reduced, our results indicate that the three models share common molecular features: an increase in mitochondrial ROS, followed by ultrastructural alterations in the mitochondrial cristae and loss of mitochondrial integrity that lead to cardiomyocyte death. We show that the ablation of the mitochondrial protease OMA1 averts cardiomyocyte death in all three experimental HF models, and thus, plays a direct role in cardiomyocyte protection. This finding identifies OMA1 as a potential target for preventing the progression of myocardial damage in HF associated to a variety of etiologies. Overall design: Transcriptome analysis of 12-week-old wild type mice versus OMA1 KO mice under control (non-treated) or treated with Isoproterenol chronically (implanted minipumps) for 7 days in heart tissue. The nuclear genetic background for both genotypes is C57BL/6JOlaHsd.
Ablation of the stress protease OMA1 protects against heart failure in mice.
Sex, Age, Specimen part, Treatment, Subject
View SamplesWe postulate here that the two singular characteristics of the mitochondrial oxidative phosphorylation system—the integration of three potentially antagonistic functions in the same structure and the double genetic origin of the components that assemble together in these molecular machines—make the evolution of an optimal system impossible. As a consequence the system is intrinsically mismatched and has to be continuously monitored, Adjusted and regulated in order to achieve the necessary and variable performance. Systematic transcriptomic, Metabolomic and biochemical evaluation of animals with identical nuclear DNA but different mtDNA haplotype strongly support the existence of intrinsic mismatch and reveals profound lifelong metabolic consequences on reactive oxygen species generation, Insulin signaling, Tendency towards obesity, And healthy ageing parameters, Including telomere atresia Overall design: Transcriptome analysis of conplastic mice versus WT mice in Liver and Heart tissues Conplastic strains were obtained after 10 generations of backcrossing to create a new line harboring the nuclear genome of one strain and the mtDNA of another (C57BL/6 and NZB were purchased from Harlan Laboratories).
Mitochondrial and nuclear DNA matching shapes metabolism and healthy ageing.
No sample metadata fields
View SamplesPurpose: Avian photoreceptors are a diverse class of neurons, comprised of four single cones, the two members of the double cone, and rods. Many distinctive features of photoreceptor subtypes, including spectral tuning, oil droplet size and pigmentation, synaptic targets and spatial patterning, have been well characterized, but the molecular mechanisms underlying these attributes have not been explored. Furthermore, the signaling events and transcriptional regulators driving the differentiation of these diverse photoreceptors are currently unknown. Methods: To identify genes specifically expressed in distinct chicken (Gallus gallus) photoreceptor subtypes, we developed fluorescent reporters that label photoreceptor subpopulations, isolated these subpopulations using fluorescence-activated cell sorting, subjected them to next-generation sequencing, and conducted differential expression analysis. Results: We identified hundreds of differentially expressed genes from photoreceptor subpopulations labeled with rhodopsin, red opsin, green opsin, and violet opsin reporters. These genes are involved in a variety of processes, including phototransduction, transcriptional regulation, cell adhesion, maintenance of intra- and extra-cellular structure, and metabolism. Of particular note are a variety of differentially expressed transcription factors, which may drive and maintain photoreceptor diversity, and cell adhesion molecules that may mediate spatial patterning of photoreceptors and act to establish retinal circuitry. Conclusions: These analyses provide a framework for future studies that will dissect the role of these various factors in the differentiation of avian photoreceptor subtypes. Overall design: mRNA expression profiling of 5 pairs of photoreceptor subtypes isolated from chicken retinal explants, 3 replicates per sample
Transcriptome profiling of developing photoreceptor subtypes reveals candidate genes involved in avian photoreceptor diversification.
Specimen part, Subject
View SamplesWe have identified loss of deiminated MA-Brent-1 (an RNA and export binding protein) in the retinal ganglion cells (RGCs) in multiple sclerosis and in glaucoma eyes compared to normal controls. Deimination refers to posttranslational modification of protein bound arginine (not free arginine) in citrulline. Our preliminary studies suggest binding of different repertoire of RNA by non-deiminated and deiminated MA-Brent-1. In vitro, in neurites of cultured RGCs and hippocampal neurons, the select mRNA translation is enhanced by addition of deiminated but not non-deiminated MA-Brent-1. These observations suggest that lack of deiminated MA-Brent-1 has consequences for protein synthesis, remodeling and plasticity of RGCs/neurons. Identification of RNA species bound by deiminated and non-deiminated MA-Brent-1 will enable us there further verification and determining the role that deimination plays in biological function of MA-Brent-1 in multiple sclerosis and glaucoma. To summarize identification of RNA species bound by deiminated and non deiminated MA-Brent-1 will enable us to gain further insight into role of deimination in the overall disease process.
The role of deimination in ATP5b mRNA transport in a transgenic mouse model of multiple sclerosis.
No sample metadata fields
View SamplesAlu SINEs are the most numerous frequently occurring transcription units in our genome and possess sequence competence for transcription by RNA Pol III. However, through poorly understood mechanisms, the Alu RNA levels are maintained at very low levels in normal somatic cells with obvious benefits of low rates of Alu retrotransposition and energy-economical deployment of RNA Pol III to the tRNA genes which share promoter structure and polymerase requirements with Alu SINEs. Using comparative ChIP sequencing, we unveil that a repeat binding protein, CGGBP1, binds to the transcriptional regulatory regions of Alu SINEs thereby impeding Alu transcription by inhibiting RNA Pol III recruitment. We show that this Alu-silencing depends on growth factor stimulation of cells and subsequent tyrosine phosphorylation of CGGBP1. Importantly, CGGBP1 ensures a sequence-specific discriminative inhibition of RNA Pol III activity at Alu promoters, while sparing the structurally similar tRNA promoters. Our data suggest that CGGBP1 contributes to growth-related transcription by preventing the hijacking of RNA Pol III by Alu SINEs.
Growth signals employ CGGBP1 to suppress transcription of Alu-SINEs.
No sample metadata fields
View SamplesMicroRNAs comprise 1-3% of all vertebrate genes, but their in vivo functions and mechanisms of action remain largely unknown. Zebrafish miR-430 is expressed at the onset of zygotic transcription and regulates morphogenesis during early development. Using a microarray approach and in vivo target validation, we find that miR-430 directly regulates several hundred target mRNAs. Targets are highly enriched for maternal mRNAs that accumulate in the absence of miR-430. We also show that miR-430 accelerates the deadenylation of target mRNAs. These results suggest that miR-430 facilitates the deadenylation and clearance of maternal mRNAs during early embryogenesis.
Zebrafish MiR-430 promotes deadenylation and clearance of maternal mRNAs.
No sample metadata fields
View SamplesPurpose: We aimed to investigate in depth the regulation of microRNA expression by hypoxia in the breast cancer cell line MCF-7, establish the relationship between microRNA expression and HIF binding sites, pri-miRNA transcription and microRNA processing gene expression. Methods: microRNA sequencing data and gene expression microarray data were generated from MCF-7 cells submitted to an hypoxia timecourse (16h, 32h and 48h at 1% Oxygen). Data was integrated to 500 published high-stringency HIF binding sites identified in MCF-7 cells. Results: We identified 41 microRNAs significantly up- and 28 down- regulated, of which 38 mature and 20 star forms are reported in conjunction with hypoxia for the first time. HIF-1a and HIF-2a binding sites within 50kb distance of microRNA loci were found by integration of HIF ChIP-seq data, showing overall association between binding sites and up-regulation. Gene expression profiling analysis showed no full coordination between pri-miRNA and microRNA expression, pointing towards additional levels of regulation. Several transcripts playing a role in microRNA processing were found regulated by hypoxia, of which two were HIF dependent. Conclusions: The data support the hypothesis that microRNA expression under hypoxia is regulated at transcriptional and post-transcriptional level. HIF is involved at both levels, regulating the transcription of certain microRNAs and also the expression of key elements of the microRNA processing pathway. Overall design: microRNA-seq profiles of MCF-7 exposed to hypoxia (1% Oxygen) for 16h (2 replicates), 32h (2 replicates) and 48h (2 replicates) and to normoxia (2 replicates) were generated using Illumina sequencing platform.
Integrated analysis of microRNA and mRNA expression and association with HIF binding reveals the complexity of microRNA expression regulation under hypoxia.
Cell line, Treatment, Subject, Time
View SamplesNPY signalling via osteoblastic Y1 receptors has been shown to control bone mass but also contributes significantly to the control of whole-body insulin secretion and glucose homeostasis in mice through the release of novel factor(s) which are different from the previously implicated osteocalcin.
Osteoglycin, a novel coordinator of bone and glucose homeostasis.
Sex, Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Genome-wide profiling of histone H3 lysine 27 and lysine 4 trimethylation in multiple myeloma reveals the importance of Polycomb gene targeting and highlights EZH2 as a potential therapeutic target.
Specimen part, Cell line
View Samples