The contribution of altered posttranscriptional gene silencing (PTGS) to the development of insulin resistance and type 2 diabetes mellitus so far remains elusive. We have described that expression of microRNAs (miR)-143 and -145 is dysregulated in genetic and dietary mouse models of obesity. Induced transgenic overexpression of miR-143, but not miR-145, causes insulin resistance and impaired insulin-stimulated AKT activation. We used microarrays to analyze the underlying molecular mechanisms of miR-143-mediated development of insulin resistance.
Obesity-induced overexpression of miRNA-143 inhibits insulin-stimulated AKT activation and impairs glucose metabolism.
Specimen part, TreatmentView Samples
Huge efforts are made to engineer safe and efficient genome editing tools. An alternative might be the harnessing of ADAR-mediated RNA editing. We now present the engineering of chemically optimized antisense oligonucleotides that recruit endogenous human ADARs to edit endogenous transcripts in a simple and programmable way, an approach we refer to as RESTORE. Notably, RESTORE was markedly precise, and there was no evidence for perturbation of the natural editing homeostasis. We applied RESTORE to a panel of standard human cell lines, but also to several human primary cells including hepatocytes. In contrast to other RNA and DNA editing strategies, this approach requires only the administration of an oligonucleotide, circumvents the ectopic expression of proteins, and thus represents an attractive platform for drug development. In this respect we have shown the repair of the PiZZ mutation causing a1-antitrypsin deficiency and the editing of phosphotyrosine 701 in STAT1. Overall design: Identification of off-target editing events and Interferon-a influence in HeLa cell line transfected with an ASO for RNA editing by RNA-Seq, 2 samples (ASO +/- IFN) , 2 control sample (+/-IFN), 2 biologically independent experiments for each sample, 8 samples in total
Precise RNA editing by recruiting endogenous ADARs with antisense oligonucleotides.
Cell line, Treatment, SubjectView Samples
The aim of the study was to generate transcriptome of wild-type and G9a mutant adult flies (females) 24h post-infection with Drosophila C Virus (DCV). Overall design: We generated 8 different data sets. For wild-type controls and G9a mutants, we performed both mock and DCV infection, and collected both whole flies and fat bodies. All flies were 3-5 days old females.
The epigenetic regulator G9a mediates tolerance to RNA virus infection in Drosophila.
Specimen part, Subject, TimeView Samples
We have developed a computational approach that uses self-organizing maps for integrative genomic analysis. We utilize this approach to identify the single-cell chromatin and transcriptomic profiles during mouse pre-B cell differentiation. Overall design: We use the C1 Fluidigm system to profile gene expression and chromatin accessibility in single-cells during pre-B cell differentiation.
Building gene regulatory networks from scATAC-seq and scRNA-seq using Linked Self Organizing Maps.
Specimen part, SubjectView Samples
We infected Drosophila S2 cells (invitrogen) with Drosophila C virus (DCV) (Multiplicity of Infection = 10), and harvested samples for further analysis at 8 and 24 hours post-infection.
The heat shock response restricts virus infection in Drosophila.
Cell line, TimeView Samples
To determine the temporal variation of mRNA levels, we collected and sequenced poly-adenylated RNA from all cell extracts, cytoplasmic and nuclear fractions of a conditional Dicer mutant [DTCM23/49 XY (Nesterova et al. 2008)] mouse Embryonic Stem Cells before induction of Dicer excision (day 0) and at days 4, 8, 10 and 12 following Dicer loss of function. coverage. Overall design: RNA from whole cell extracts was collected at days 0, 4, 8, 10 and 12 following loss of Dicer function and from the cytoplasmic and nuclear fractions of cell at day 0 and 12. Three biological replicates were obtained for all samples. Poly-adenylated directional 100 base paired-end sequencing libraries were prepared for all extracts and sequenced by BGI solutions (Hong Kong).
Extensive microRNA-mediated crosstalk between lncRNAs and mRNAs in mouse embryonic stem cells.
No sample metadata fieldsView Samples
Maternal smoking has a severe negative effect on all stages of pregnancy that in consequence impairs fetal growth and development. Tobacco smoke-related defects are well established at the clinical level; however, little is known about molecular mechanisms underlying these pathological conditions. We thus employed a genomic approach to determine transcriptome alterations induced by maternal smoking in pregnancy. We assayed gene expression profiles in peripheral blood (M) leukocytes and placentas (PL) of pregnant smokers and those without significant exposure, and in cord blood (D) leukocytes of their babies. Comparative analyses defined significant deregulation of 193 genes in M cells, 329 genes in placentas, and 49 genes in D cells of smokers. These genes were mainly involved in xenobiotic metabolism, oxidative stress, inflammation, immunity, hematopoiesis, trophoblast differentiation, and vascularization. Functional annotation of the deregulated genes outlined processes and pathways affected by tobacco smoke. In smoker newborns, we identified several deregulated pathways associated with autoimmune diseases. The study demonstrates a limited ability of placenta to modulate toxic effects of maternal tobacco use at the gene expression level.
Transcriptome alterations in maternal and fetal cells induced by tobacco smoke.
Age, Specimen part, SubjectView Samples
Passive smoke intake by pregnant women may have detrimental effects such as spontaneous abortion, lower birth weight, stillbirth, and reduced infant lung function. To extend our knowledge on molecular effects of tobacco smoke exposure in pregnancy, we analyzed transcriptome alterations in passive smokers (PS) and compared them to those in active smokers (AS). Using Illumina Expression Beadchip with 24,526 transcript probes, gene expression patterns were assayed in placentas from PS (N=25) exposed to environmental tobacco smoke (ETS) throughout pregnancy and non-exposed (NS) counterparts (N=35), and in cord blood cells from their newborns. The ETS exposure was evaluated by questionnaire disclosure and cotinine measurement in maternal and cord bloods. A total of 196 genes were significantly deregulated in placentas of PS compared to NS. These genes were primary associated with extracellular matrix, apoptosis, blood clotting, response to stress, embryonic morphogenesis, and lipid metabolism. Cord blood of newborns of PS displayed differential expression of 116 genes encoding mainly neuronal factors, regulators of immunologic response, and protooncogenes. Gene ontology analyses highlighted some important biological processes that might be associated with placental insufficiency and fetal growth restriction in PS, such as fatty acid catabolism, coagulation, regulation of growth, and response to steroid hormone stimulus. The study demonstrates that even low dose exposure to ETS during pregnancy leads to the significant deregulation of transcriptional regulation in placental and fetal cells. The data suggest the effect of ETS on the fetus is primary indirect, mediated via deregulation of placental functions. Comparison of PS and AS indicated that ETS exposure and active smoking in pregnancy partly employ the same molecular mechanisms.
Deregulation of gene expression induced by environmental tobacco smoke exposure in pregnancy.
Purpose: Investigating the role of Drosophila G9a in oxidative stress responses. Methods: Flies were collected after eclosion and allowed to recover from CO2 exposure for 5 days prior to paraquat exposure. Paraquat (Methyl viologen dichloride hydrate 98 %; Sigma 856177) was mixed into the flyfood at 40 °C to a final concentration of 50 mM. For OS induction, 5-9 day old flies were transferred to paraquat containing food and incubated at 25 °C and 70 % humidity. At each time point, flies were flash frozen in liquid nitrogen followed by vortexing and filtering through a series of sieves to isolate heads from other body parts. 200 fly heads per sample were used for RNA extraction using QIAGEN lipid mini tissue kit. The TruSeq RNA Sample Preparation Kit v2 (Illumina) was used to prepare adapter ligated PCR fragments for sequencing. PCR was used to selectively enrich the fragments containing the adapters. The PCR fragments were validated using Agilent 2200 TapeStation. Single indexed samples were multiplexed and sequenced on an Illumina HiSeq 2000 sequencing system (Illumina) in single-end mode with a read length of 35 bp. Quality of sequenced reads was assessed with FastQC. The RNAseq experiments were conducted on two biological duplicates for each condition. Sequenced reads were aligned with Burrows-Wheeler algorithm (BWA) (Li & Durbin, 2010) to the Drosophila reference genome (BDGP.5, http://www.fruitfly.org/) and per gene read counts were generated with HTSeq count (Anders et al, 2015). 25–30 million reads with high quality alignment were obtained for each sample and used for differential expression analysis. DESeq (Anders & Huber, 2010) was used to obtain library size-normalized read counts and to calculate differential expression of genes in 4 pairwise comparisons: 0 h versus 6 h and 0 h versus 12 h after OS in both G9a mutants and controls (fold change =1.5, adjusted p-value= 0.05, Benjamini-Hochberg). Results: We found 2731 genes to be differential expressed in at least one of the four pairwise comparisons. The largest group of differentially expressed (DE) genes are highly augmented upon OS induction in the G9a mutant (41.7 % of all DE genes). The second largest group of DE genes (23.9 % of all DE genes) were more downregulated in G9a mutant in response to OS. Genes that are over-activated in G9a mutants are predominantly involved in OS response and OS mediated damage, whereas genes that are downregulated in G9a mutants are involved in energy metabolism. Conclusions: Our data suggest that G9a provides an epigenetic mechanism that safeguards an appropriate transcriptional response to OS and preserves immediately available energy, thereby acting as a critical regulatory hub between the transcriptional and physiological responses to oxidative stress. Overall design: fly-head mRNA libraries of 5-9 days old male G9aDD1 mutant and control during 0, 6 and 12 hours of paraquat oxidative stress exposure were sequenced in duplicate on Hi-seq 2000.
The histone methyltransferase G9a regulates tolerance to oxidative stress-induced energy consumption.
Specimen part, Treatment, SubjectView Samples
The RNase III enzyme dicer is essential for the processing of microRNAs (miRNAs) and small interfering RNAs (siRNAs) from double-stranded RNA precursors. miRNAs and siRNAs regulate chromatin structure, gene transcription, mRNA stability and translation in a wide range of organisms. To provide a model system to explore the role of dicer-generated RNAs in the differentiation of mammalian cells in vivo, we have generated a conditional dicer allele. Deletion of dicer at an early stage of T cell development compromised the survival of lineage cells, while the numbers of -expressing thymocytes were not affected. In developing thymocytes, dicer was not required for the maintenance of transcriptional silencing at pericentromeric satellite sequences (constitutive heterochromatin), the maintenance of cytosine DNA methylation and X chromosome inactivation in female cells (facultative heterochromatin) and the stable shutdown of a developmentally regulated gene (developmentally regulated gene silencing). Most remarkably, given that one-third of mammalian mRNAs are putative miRNA targets, dicer appears to be dispensable for CD4/8 lineage commitment, a process where epigenetic regulation of lineage choice has been well documented. Thus, although dicer appears critical for the development of the early embryo, it may have limited impact on the implementation of lineage-specific gene expression programs.
microRNAs regulate cell-to-cell variability of endogenous target gene expression in developing mouse thymocytes.
Specimen partView Samples