PIWI interacting RNAs (piRNAs) provide defense against transposable element (TE) expansion in the germline of metazoans. piRNAs are processed from the transcripts encoded by specialized heterochromatic clusters enriched in damaged copies of transposons. How these regions are recognized as a source of piRNAs is still elusive. The aim of this study is to determine how transgenes that contain a fragment of the LINE-like I transposon lead to an acquired TE resistance in Drosophila. We show that such transgenes, being inserted in unique euchromatic regions which normally do not produce small RNAs, become de novo bidirectional piRNA clusters that silence I-element activity in the germline. Strikingly, small RNAs of both polarities are generated from the entire transgene and flanking genomic sequences — not only from the transposon fragment. Chromatin immunoprecipitation analysis shows that in ovaries the trimethylated histone 3 lysine 9 (H3K9me3) mark associates with transgenes producing piRNAs. We show that transgene-derived hsp70 piRNAs stimulate in trans cleavage of cognate endogenous transcripts with subsequent processing of the non-homologous parts of these transcripts into piRNAs. Overall design: The fractions of small RNAs (19-29 nt) from ovaries of wild type and 11 transgenic lines of Drosophila melanogaster were sequenced using Illumina HiSeq 2000.
De novo piRNA cluster formation in the Drosophila germ line triggered by transgenes containing a transcribed transposon fragment.
Specimen part, Subject
View SamplesWe used microarrays to compare the global programme of gene expression in HTLV-positive, ATL-derived and HTLV-positive in vitro-transformed cell lines with that of uninfected primary CD4 T cells.
Elevated cyclic AMP levels in T lymphocytes transformed by human T-cell lymphotropic virus type 1.
Specimen part
View SamplesMultiple signaling pathways, structural proteins and transcription factors are involved in regulation of endothelial barrier function. The Forkhead protein FOXF1 is a key transcriptional regulator of lung embryonic development, and we use a conditional knockout approach to examine the role of FOXF1 in adult lung homeostasis and lung injury and repair. Tamoxifen-regulated deletion of both Foxf1 alleles in endothelial cells of adult mice (Pdgfb-iCreER/Foxf1 caused lung inflammation and edema, leading to respiratory insuffency and uniform mortality. Deletion of a single foxf1 allele was sufficient to increase susceptibility of heterozygous mice to acute lung injury. FOXF1 abundance was decreased in pulmonary endothelial cells of human patients with acute lung injury. Gene expression analysis of pulmonary endothelial cells of FOXF1 deletion indicated reduced expression for genes critical for maintance and regulation of adherens junctions. FOXF1 knockdown in vitro and in vivo disrupted adherens junctions, increased lung endothelial permeability, and the abundance of mRNA and protein for sphingosine 1 phosphate receptor 1 (S1PR1), a key regulator of endothelial barrier function. Chromatin immunoprecipitation and luciferase reporter assay demonstrated that FOXF1 directly bound to and induced the tanscriptional activity of the S1pr1 promoter. Pharmacological administratiion of S1P to injured pdgfb-iCreER/Foxf1 mice restored endothelial barrier function, decreased lung edema and improved survival. Thus, FOXF1 promotes normal lung homeostasis and lung repair, at least in part, by enhancing endothelial barrier function through transcriptional activation of the S1P/S1PR1/ signaling pathway. Overall design: RNA was isolated and pooled from the lungs of multiple mice with either the Foxf1 floxed alleles alone or Pdgfb-iCreER Foxf1 floxed mice.
FOXF1 maintains endothelial barrier function and prevents edema after lung injury.
Specimen part, Subject
View SamplesMyotonic dystrophy type 1 (DM1) is a dominantly inherited disease that affects multiple organ systems. Cardiac dysfunction is the second leading cause of death in DM1. We quantified gene expression in heart tissue from a heart-specific DM1 mouse model (EpA960/MCM) which inducibly expresses human DMPK exon 15 containing 960 CUG expanded repeats and that reproduced Celf1 up regulation. To assess if, in addition to splicing and miRNA defects, CUGexp RNA also perturbed the steady state mRNA levels of genes, we carried out a microarray study on wildtype E14, adult, MCM controls and DM1 mouse hearts. As anticipated we noted a large number of genes to be developmentally regulated in wildtype hearts, however, within 72h of induction of CUGexp RNA there appeared to be a coordinate adult-to-embryonic shift in steady state levels of many genes.
The Mef2 transcription network is disrupted in myotonic dystrophy heart tissue, dramatically altering miRNA and mRNA expression.
Specimen part, Time
View SamplesHepatic fibrosis is the common end stage to a variety of chronic liver injuries and is characterized by an excessive deposition of extracellular matrix (ECM), which disrupts the liver architecture and impairs liver function. The fibrous lesions are produced by myofibroblasts, which differentiate from hepatic stellate cells (HSC). The myofibroblasts transcriptional networks remain poorly characterized. Previous studies have shown that the Forkhead box F1 (FOXF1) transcription factor is expressed in HSCs and stimulates their activation during acute liver injury; however, the role of FOXF1 in the progression of hepatic fibrosis is unknown. In the present study, we generated aSMACreER;Foxf1fl/fl mice to conditionally inactivate Foxf1 in myofibroblasts during carbon tetrachloride-mediated liver fibrosis. Foxf1 deletion increased collagen depositions and disrupted liver architecture. Timp2 expression was significantly increased in Foxf1-deficient mice while MMP9 activity was reduced. RNA sequencing of purified liver myofibroblasts demonstrated that FOXF1 inhibits expression of pro-fibrotic genes, Col1a2, Col5a2, and Mmp2 in fibrotic livers and binds to active repressors located in promotors and introns of these genes. Overexpression of FOXF1 inhibits Col1a2, Col5a2, and MMP2 in primary murine HSCs in vitro. Altogether, FOXF1 prevents aberrant ECM depositions during hepatic fibrosis by repressing pro-fibrotic gene transcription in myofibroblasts and HSCs. Overall design: RNAseq on isolated hepatic stromal cells from Foxf1 fl/fl and aSMACreER;Foxf1 fl/fl mice after 5 weeks of carbon tetrachloride-induced liver injury.
The Forkhead box F1 transcription factor inhibits collagen deposition and accumulation of myofibroblasts during liver fibrosis.
Specimen part, Cell line, Subject
View SamplesAlternative cleavage and polyadenylation (APA) results in mRNA isoforms containing different 3' untranslated regions (3'UTRs) and/or coding sequences. How core cleavage and polyadenylation (C/P) factors regulate APA is not well understood. Using siRNA knockdown coupled with deep sequencing, we found that several C/P factors can play significant roles in 3'UTR-APA. Whereas Pcf11 and Fip1 enhance usage of proximal poly(A) sites (pAs), CFI-25/68, PABPN1, and PABPC1 promote usage of distal pAs. Strong cis element biases were found for pAs regulated by CFI or Fip1, and the distance between pAs plays an important role in APA regulation. In addition, intronic pAs are substantially regulated by splicing factors, with U1 mostly influencing C/P events in 5' introns and U2 impacting those in efficiently spliced introns. Furthermore, PABPN1 regulates expression of transcripts with pAs near the transcription start site, a property possibly related to its role in RNA degradation. Finally, we found that groups of APA events regulated by C/P factors are also modulated in cell differentiation and development with distinct trends. Together, our results indicate that the abundance of different C/P factors and splicing factors plays diverse roles in APA, and is relevant to APA regulation in biological conditions. Overall design: knockdown experiments of 23 C/P factors, 3 splicing factors and U1D in mouse C2C12 myoblast cells
Systematic profiling of poly(A)+ transcripts modulated by core 3' end processing and splicing factors reveals regulatory rules of alternative cleavage and polyadenylation.
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View SamplesTranscription factor FoxM1 is expressed in proliferating cells, and its expression is critical for cell proliferation in embryos and tumors. FoxM1 regulates a multi-gene transcriptional network for cell cycle regulation.
Forkhead box M1 transcriptional factor is required for smooth muscle cells during embryonic development of blood vessels and esophagus.
Specimen part
View SamplesWe have identified the causal genes, which is MYB36, of ionome mutants.
The MYB36 transcription factor orchestrates Casparian strip formation.
Specimen part
View SamplesGene expression profiling for identification of genes regulated by DNA methylation
Genome-wide screening of genes regulated by DNA methylation in colon cancer development.
Specimen part, Cell line
View SamplesWhole genomic microarray analysis was performed in order to identify gene expression profile alterations focusing on the dysplastic adenoma-carcinoma transition. Our aims were to determinate characteristic transcript sets for developing diagnostic mRNA expression patterns for objective classification of benign and malignant colorectal diseases and to test the classificatory power of these markers on an independent sample set.
Myofibroblast-derived SFRP1 as potential inhibitor of colorectal carcinoma field effect.
Disease, Disease stage
View Samples