Transcription can be quite disruptive for chromatin so cells have evolved mechanisms to preserve chromatin integrity during transcription, hence preventing the emergence of cryptic transcript from spurious promoter sequences. How these transcripts are regulated and processed by cells remains poorly characterized. Notably, very little is known about the termination of cryptic transcription. Here we used RNA-Seq to identify and characterize cryptic transcripts in Spt6 mutant cells (spt6-1004) in Saccharomyces cerevisiae. We found polyadenylated cryptic transcripts running both sense and anti-sense relative to genes in this mutant. Cryptic promoters were enriched for TATA boxes, suggesting that the underlying DNA sequence defines the location of cryptic promoters. While intragenic sense cryptic transcripts terminate at the terminator of the genes that host them, we found that anti-sense cryptic transcripts preferentially terminate at the 3’-end of upstream genes. These findings led us to demonstrate that most terminators in yeast are bidirectional, leading to termination and polyadenylation of transcripts coming from either direction. We propose that S. cerevisiae has evolved this mechanism in order to prevent spurious transcription from invading neighbouring genes, a feature particularly critical for organisms with small compact genomes. Overall design: Cells from spt16-1004 and its respective WT strain were grown to an OD600 of 0.5 at 30°C and shifted to 37°C for 80 min before RNA extraction. Total RNA was extracted using the hot phenol method. Prior to library preparation, total RNA was either depleted for ribosomal RNA using the Ribo-zero Gold yeast kit (Epicentre-Illumina) or enriched for polyadenylated RNA using the NEBnext Poly(A) kit (New England Biolabs). Strand specific RNA-seq libraries were prepared using the KAPA stranded RNA-Seq library preparation kit prior to paired-end sequencing on an Illumina Hi-Seq2000. Reads were mapped to the sacCer3 assembly of the S. cerevisiae genome using Tophat2 (23). Intron length range was set at 50 to 1000 bp and a reference annotation file was provided to guide the assembly.
Bidirectional terminators in Saccharomyces cerevisiae prevent cryptic transcription from invading neighboring genes.
Cell line, Subject
View SamplesThis SuperSeries is composed of the SubSeries listed below.
ChIP-on-chip analysis identifies IL-22 as direct target gene of ectopically expressed FOXP3 transcription factor in human T cells.
Cell line
View SamplesThe transcription factor (TF) Forkhead Box P3 (FOXP3) is constitutively expressed in high levels in natural occurring CD4+CD25+ regulatory T cells (nTreg) and is not only the most accepted marker for that cell population, but is considered lineage determinative. Chromatin immunoprecipitation (ChIP) of transcription factors in combination with genomic tiling microarray analysis (ChIP-on-Chip) has been shown to be an appropriate tool to identify FOXP3 transcription factor binding sites (TFBS) on a genome-wide scale. In combination with microarray expression analysis the ChIP-on-Chip technique allows to identify direct FOXP3 target genes. This dataset shows expression data of resting and mitogen stimulated (PMA / ionomycin) retrovirally transduced Jurkat T cells either expressing FOXP3(2) (J-FOXP3) or an empty vector control (J-GFP).
ChIP-on-chip analysis identifies IL-22 as direct target gene of ectopically expressed FOXP3 transcription factor in human T cells.
Cell line
View SamplesBackground: Influenza A virus (IAV) infections periodically cause substantial morbidity and mortality in the human population. In the lung, the primary targets for IAV replication are type II alveolar epithelial cells (AECII), which are increasingly recognized for their immunological potential. However, our knowledge of the role of AECII in anti-IAV immunity is incomplete and their in vivo response to infection has not been evaluated. To increase our understanding of their role in host-response to IAV-infection, we analyzed transcriptional regulation in primary AECII isolated from infected mice. Results: Microarray analyses of AECII isolated on the first three days following IAV-infection revealed extensive transcriptional regulation. A multitude of differentially expressed transcripts was identified and in comparison to whole-lung tissue revealed a strong contribution of AECII to respiratory anti-IAV responses. Type I interferon played a major role in the detected gene expression profile and functional pathway analyses showed AECII to be highly active in pathogen recognition, cell recruitment and antigen-presentation. Analysis of Toll-like receptor 7 (TLR7) deficient mice indicated AECII to rely on the hosts expression of this innate IAV-sensor to elicit their full response. Importantly, the AECII transcriptional profiles correlated to cell recruitment and type I interferon levels detected in the lungs of infected animals. Conclusions: Ex vivo analysis of primary murine AECII proved as a powerful tool to increase our understanding of AECII biology in infection. Our analysis revealed an exceptionally strong contribution of AECII to local host defenses by integrating signals provided by surrounding cells and direct pathogen recognition.
Alveolar Type II Epithelial Cells Contribute to the Anti-Influenza A Virus Response in the Lung by Integrating Pathogen- and Microenvironment-Derived Signals.
Treatment
View SamplesNoncommunicable chronic respiratory diseases (CRDs) such as chronic obstructive pulmonary disease (COPD) and asthma affect hundreds of millions of people and are associated with increasing morbidity and mortality. CRDs are multifactorial disorders and despite different etiologies they commonly manifest in pulmonary structural (airway remodeling, emphysema) and/or functional changes. In this study we used mice intrinsically developing autoimmune-mediated lung inflammation associated with lung pathology and immune imprinting partly comparable to hallmarks of CRD. The so called SPC-HAxTCR-HA transgenic mice (BALB/c genetic background), express a neo-self antigen (influenza A virus hemagglutinin, HA) on lung alveolar epithelial type II cells in the presence of HA-specific CD4+ T cells leading to the establishment of chronic lung inflammation. In order to characterize the inflammatory lung milieu of SPC-HAxTCR-HA mice in comparison to SPC-HA control mice (lacking HA-specific CD4+ T cells), we performed whole lung tissue transcriptional analyses (n = 3 / group). 378 transcripts were found to be differentially expressed in SPC-HAxTCR-HA lungs. 326 of those were up-regulated and 52 were down-regulated compared to SPC-HA control mice.
Chronic lung inflammation primes humoral immunity and augments antipneumococcal resistance.
Sex, Age, Specimen part
View SamplesChronic obstructive pulmonary disease (COPD) is a heterogenous respiratory disease mainly caused by smoking. Respiratory infections constitute a major risk factor for acute worsening of COPD symptoms or COPD exacerbation. Mitochondrial functionality, which is crucial for the execution of physiologic functions of metabolically active cells, is impaired in airway epithelial cells (AECs) of COPD patients as well as smokers. However, the potential contribution of mitochondrial dysfunction in AECs to progression of COPD, infection-triggered exacerbations in AECs and a potential mechanistic link between mitochondrial and epithelial barrier dysfunction is unknown to date. In this study, we used an in vitro COPD exacerbation model based on AECs exposed to cigarette smoke extract (CSE) followed by infection with Streptococcus pneumoniae (Sp). The levels of oxidative stress, as an indicator of mitochondrial stress were quantified upon CSE and Sp. The expression of proteins associated with mitophagy, mitochondrial content and biogenesis as well as mitochondrial fission and fusion was quantified upon CSE and Sp. Transcriptional AEC profiling was performed to identify the potential changes in innate immune pathways and correlate them with mitochondrial function. We found that CSE exposure substantially altered mitochondrial function in AECs by suppressing mitochondrial complex protein levels, reducing mitochondrial membrane potential and increasing mitochondrial stress and mitophagy. Moreover, CSE-induced mitochondrial dysfunction correlated with reduced enrichment of genes involved in apical junctions and innate immune responses to Sp, particularly type I interferon responses. Together, our results demonstrated that CSE-induced mitochondrial dysfunction may contribute to impaired innate immune responses to Sp and may thus trigger COPD exacerbation.
Cigarette Smoke Extract Disturbs Mitochondria-Regulated Airway Epithelial Cell Responses to Pneumococci.
Specimen part, Cell line, Treatment
View SamplesGoals and objectives of this study: to identify genes preferentially induced in human CD4+CD25hi Treg cells following T-cell activation with potential role for stabililization & maintenance of the regulatory program.
GARP: a key receptor controlling FOXP3 in human regulatory T cells.
Specimen part
View SamplesGoals and objectives of this study: to identify genes of the Treg signature induced by consitutive expression of GARP or FOXP3 in antigen-specific Th cells with potential role for stabililization & maintenance of the regulatory program.
GARP: a key receptor controlling FOXP3 in human regulatory T cells.
Specimen part
View SamplesIntact living conduit vessels (umbilical veins) were exposed to normal or high intraluminal pressure, or low or high shear stress in combination with a physiological level of the other force. We used a unique vascular ex vivo perfusion system. After six hours of perfusion endothelial cells were isolated from the stimulated vessels and RNA was extracted. RNA from 16 experiments from each stimulation were pooled and analyzed in duplicate DNA microarrays.
Differential global gene expression response patterns of human endothelium exposed to shear stress and intraluminal pressure.
No sample metadata fields
View SamplesGlomerular podocytes are highly differentiated cells that are key components of the kidney filtration units. The podocyte cytoskeleton builds the basis for the dynamic podocyte cytoarchitecture and plays a central role for proper podocyte function. Recent studies implicate that immunosuppressive agents including the mTOR-inhibitor everolimus have a protective role directly on the stability of the podocyte cytoskeleton. To elucidate mechanisms underlying mTOR-inhibitor mediated cytoskeletal rearrangements, we carried out microarray gene expression studies to identify target genes and corresponding pathways in response to everolimus. We analyzed the effect of everolimus in a puromycin aminonucleoside experimental in vitro model of podocyte injury. Upon treatment with puromycin aminonucleoside, microarray analysis revealed gene clusters involving cytoskeletal-associated pathways, adhesion, migration and extracellular matrix composition to be affected. Everolimus is capable of protecting podocytes from injury, both on the transcriptome and protein level. Rescued genes included TUBB2B and DCDC2, both involved in microtubule structure formation in neuronal cells but not identified in podocytes so far. Confirming gene expression data, Western-blot analysis in cultured podocytes showed an increase of TUBB2B and DCDC2 protein after everolimus treatment, and immunohistochemistry in healthy control kidneys confirmed a podocyte-specific expression. Microtubule-inhibitor experiments led to a maldistribution of TUBB2B and DCDC2 as well as an aberrant reorganization of the actin cytoskeleton. Tubb2bbrdp/brdp mice showed a delay in glomerular podocyte and capillary development. Taken together, our study suggests that off-target, non-immune mediated effects of the mTOR-inhibitor everolimus on the podocyte cytoskeleton might involve regulation of microtubules, revealing a potential novel role of TUBB2B and DCDC2 in glomerular podocyte development
Everolimus Stabilizes Podocyte Microtubules via Enhancing TUBB2B and DCDC2 Expression.
Specimen part, Treatment
View Samples