So far, the annotation of translation initiation sites (TISs) has been based mostly upon bioinformatics rather than experimental evidence. We adapted ribosomal footprinting to puromycin-treated cells to generate a transcriptome-wide map of TISs in a human monocytic cell line. A neural network was trained on the ribosomal footprints at previously annotated AUG translation initiation codons (TICs), and used for the ab initio prediction of TISs in 5062 transcripts with sufficient sequence coverage. Functional interpretation suggested 2994 novel upstream open reading frames (uORFs) in the 5´ UTR (924 AUG, 2070 near-cognate codons), 1406 uORFs overlapping with the coding sequence (116 AUG, 1290 near-cognate) and 546 N-terminal protein extensions (6 AUG, 540 near-cognate). The TIS detection method was validated on the basis of previously published alternative TISs and uORFs. On average, TICs in newly annotated TISs were significantly more conserved among primates than control codons, both for AUGs (p<10-10) and near-cognate codons (p=3.8×10-3). The derived transcriptome-wide map of novel candidate TISs will help to explain how human proteome diversity is influenced by alternative translation initiation and regulation. Overall design: Examination of translational initiation in human cell lines using ribosomal footprinting
Genome-wide search for novel human uORFs and N-terminal protein extensions using ribosomal footprinting.
Cell line, Treatment, Subject
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Obesity accelerates epigenetic aging of human liver.
Sex, Age, Disease, Subject
View SamplesN=134 human liver samples from morbidly obese patients and healthy controls were analysed by array-based mRNA expression profiling. Liver messenger RNA expression datasets from the German patients were generated on the HuGene 1.1 ST gene array The purpose of the study was to correlate these gene expression data with body mass index and with an epigenetic measure of age acceleration based on DNA methylation data.
Obesity accelerates epigenetic aging of human liver.
Sex, Age, Disease, Subject
View SamplesNon-alcoholic fatty liver disease (NAFLD) is the most common chronic liver disorder in industrialized countries. Liver samples from morbidly obese patients (N=45) with all stages of NAFLD and controls (N=18) were analysed by array-based DNA methylation and mRNA expression profiling. NAFLD-specific expression and methylation differences were seen for nine genes coding for key enzymes in intermediate metabolism (including PC, ACLY, PLCG1) and insulin/insulin-like signalling (including IGF1, IGFBP2, PRKCE) and replicated by bisulfite pyrosequening (independent N=39). Transcription factor binding sites at NAFLD-specific CpG sites were >1000-fold enriched for ZNF274, PGC1A and SREBP2. Intra-individual comparison of liver biopsies before and after bariatric surgery showed NAFLD-associated methylation changes to be partially reversible. Post-bariatric and NAFLD-specific methylation signatures were clearly distinct both in gene-ontology and transcription factor binding site analyses, with >400-fold enrichment of NRF1, HSF1 and ESRRA sites. Our findings provide one of the first examples of treatment-induced epigenetic organ remodelling in humans.
DNA methylation analysis in nonalcoholic fatty liver disease suggests distinct disease-specific and remodeling signatures after bariatric surgery.
Sex, Age, Specimen part
View SamplesAnalysis of estrogen receptor (ER)-positive MCF7 cell total RNA expression and polysome-assiciated RNA expression following treatment with estradiol (E2) and vehicle (etoh).
Estrogen coordinates translation and transcription, revealing a role for NRSF in human breast cancer cells.
Cell line
View SamplesHypothesis: Overexpression of the GLUT1 facilitative glucose transporter, in A7r5 vascular smooth muscle cells, is sufficient and/or necessary to induce alterations in gene expression which influence apoptosis, growth, and proliferation.
GLUT1-induced cFLIP expression promotes proliferation and prevents apoptosis in vascular smooth muscle cells.
Cell line
View SamplesDiabetic Neuropathy (DN) is a common complication of diabetes. Currently, there is no drug treatment to prevent or slow the development of DN. Rosiglitazone (Rosi) is a potent insulin sensitizer and may also slow the development of DN by a mechanism independent of its effect on hyperglycemia. A two by two design was used to test the effect of Rosi treatment on the development of DN. Streptozotocin-induced diabetic DBA/2J mice were treated with Rosi. DN and oxidative stress were quantified, and gene expression was profiled using the Affymetrix Mouse Genome 430 2.0 microarray platform. An informatics approach identified key regulatory elements activated by Rosi. Diabetic DBA/2J mice developed severe hyperglycemia, DN and elevated oxidative stress. Rosi treatment did not affect hyperglycemia but did reduce oxidative stress and prevented development of thermal hypoalgesia. Two novel transcription factor binding modules were identified that may control genes correlated to changes in DN following Rosi treatment: SP1F_ZBPF and EGRF_EGRF. Rosi treatment reduced oxidative stress and DN independent of its insulin sensitizing effects. Gene expression profiling identified two novel targets activated by Rosi treatment. These targets may be useful in designing drugs with the same efficacy as Rosi in treating DN but with fewer undesirable effects.
Rosiglitazone treatment reduces diabetic neuropathy in streptozotocin-treated DBA/2J mice.
Specimen part, Treatment
View SamplesLoss-of-function studies are fundamental for dissecting gene function. Yet, methods to rapidly and effectively perturb genes in mammalian cells are scarce. We present a novel system, deliverable with only two lentiviral vectors, which enables simultaneous control over two different proteins in the same cell. By harnessing the plant auxin and jasmonate hormone-induced degradation pathways, combined with RNA interference, this system allows constitutive depletion of two endogenous proteins and their replacement with two exogenous proteins whose degradation is rapidly and reversibly induced by external ligands, representing a dual analog molecular tuner. Focusing on NANOG, CHK1 and NOTCH1 in embryonic stem cells and p53 in cancer cells we have validated the efficiency, rapidity, reversibility, titratability and multiplicity of the engineered tuners, and demonstrated their potential to facilitate previously-unfeasible experimental approaches and to generate novel biological insights. Overall design: For mRNA-Seq preparation, coronatine/DMSO treated cells were collected.
A dual molecular analogue tuner for dissecting protein function in mammalian cells.
No sample metadata fields
View SamplesPurpose: The ability to rationally manipulate the transcriptional states of cells would be of great use in medicine and bioengineering. We have developed a novel algorithm, NetSurgeon, which utilizes genome-wide gene regulatory networks to identify interventions that force a cell toward a desired expression state. Results: We used NetSurgeon to select transcription factor deletions aimed at improving ethanol production in S. cerevisiae cultures that are catabolizing xylose. We reasoned that interventions that move the transcriptional states of cells utilizing xylose toward the fermentative state typical of cells that are producing ethanol rapidly (while utilizing glucose) might improve xylose fermentation. Some of the interventions selected by NetSurgeon successfully promoted a fermentative transcriptional state in the absence of glucose, resulting in strains with a 2.7-fold increase in xylose import rates, a 4-fold improvement in xylose integration into central carbon metabolism, or a 1.3-fold increase in ethanol production rate. Conclusions: We conclude by presenting an integrated model of transcriptional regulation and metabolic flux that will enable future metabolic engineering efforts aimed at improving xylose fermentation to prioritize functional regulators of central carbon metabolism. Overall design: Mutant and wildtype S. cerevisiae cells were put into 48 hour aerobic batch fermentations of synthetic complete medium supplmented with 2% glucose and 5% xylose and culture samples were taken at 4 hours and 24 hours for transcriptional profiling performed by RNA-Seq analysis. In addition, wildtype S. cerevisiae cells were grown in various single carbon sources for 12 hours and culture samples were taken for transcriptional profiling performed by RNA-Seq analysis.
Model-based transcriptome engineering promotes a fermentative transcriptional state in yeast.
Subject
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Retained heterodisomy is associated with high gene expression in hyperhaploid inflammatory leiomyosarcoma.
Sex, Specimen part, Disease, Disease stage
View Samples