Type I interferon-stimulated genes (ISGs) have critical roles in inhibiting virus replication and dissemination. Despite advances in understanding the molecular basis of ISG restriction, the antiviral mechanisms of many remain unclear. The 20 kDa ISG, ISG20, is a nuclear 3''-5''exonuclease with preference for single stranded RNA (ssRNA) and has been implicated in the IFN-mediated restriction of several RNA viruses. Although the exonuclease activity of ISG20 has been shown to degrade viral RNA in vitro, evidence has yet to be presented that virus inhibition in cells requires this activity. Here, we utilized a combination of an inducible, ectopic expression system and newly generated Isg20-/- mice to investigate mechanisms and consequences of ISG20-mediated restriction. Ectopically expressed ISG20 localized primarily to Cajal bodies in the nucleus and restricted replication of chikungunya and Venezuelan equine encephalitis viruses. Although restriction by ISG20 was associated with inhibition of translation of infecting genomic RNA, degradation of viral RNAs was not observed. Instead, translation inhibition of viral RNA was associated with ISG20-induced upregulation of over 100 other genes, many of which encode known antiviral effectors. ISG20 modulated the production of IFIT1, an ISG that suppresses translation of alphavirus RNAs. Consistent with this observation, the pathogenicity of IFIT1-sensitive alphaviruses was increased in Isg20-/- mice compared to wild-type viruses, but not in ISG20 ectopic-expressing cells. Our findings establish an indirect role for ISG20 in the early restriction of RNA virus replication by regulating expressionof other ISGs that inhibit translation and possibly other activities in the replication cycle. Overall design: Two clones each of tet-inducible MEFs overexpressing eGFP (control), Isg20, and Isg20(D94G) were induced by tetracycline removal for 72 hours. rRNA was depleted with RiboMinus Eukaryote kit (Life Technologies) and prepared for Illumina directional 100bp paired-end HiSeq2000 reads.
The Interferon-Induced Exonuclease ISG20 Exerts Antiviral Activity through Upregulation of Type I Interferon Response Proteins.
Specimen part, Cell line, Subject
View SamplesOne of the major players controlling RNA decay is the cytoplasmic 5'-to-3' exoribonuclease, which is conserved among eukaryotic organisms. In Arabidopsis, the 5'-to-3' exoribonuclease XRN4 is involved in disease resistance, the response to ethylene, RNAi, and miRNA-mediated RNA decay. Curiously, XRN4 appears to display selectivity among its substrates because certain 3' cleavage products formed by miRNA-mediated decay, such as from ARF10 mRNA, accumulate in the xrn4 mutant, whereas others, such as from AGO1, do not. To examine the nature of this selectivity, transcripts that differentially accumulate in xrn4 were identified by combining PARE and Affymetrix arrays. Certain functional categories, such as stamen-associated proteins and hydrolases, were over-represented among transcripts decreased in xrn4, whereas transcripts encoding nuclear-encoded chloroplast-targeted proteins and nucleic acid-binding proteins were over-represented in transcripts increased in xrn4. To ascertain if RNA sequence influences the apparent XRN4 selectivity, a series of chimeric constructs was generated in which the miRNA-complementary sites and different portions of the surrounding sequences from AGO1 and ARF10 were interchanged. Analysis of the resulting transgenic plants revealed that the presence of a 150 nucleotide sequence downstream from the ARF10 miRNA-complementary site conferred strong accumulation of the 3' cleavage products in xrn4. In addition, sequence analysis of differentially accumulating transcripts led to the identification of 27 hexamer motifs that were over-represented in transcripts or miRNA-cleavage products accumulating in xrn4. Taken together, the data indicate that specific mRNA sequences, like those in ARF10, and mRNAs from select functional categories are attractive targets for XRN4-mediated decay.
Evidence that XRN4, an Arabidopsis homolog of exoribonuclease XRN1, preferentially impacts transcripts with certain sequences or in particular functional categories.
Specimen part
View SamplesIn this study, we hypothesize that acetyl CoA carboxylase (ACC) is an important intermediate in Cystic fibrosis (CF) inflammatory signaling cascade. Here, we demonstrate that ACC inhibition mimics the cellular effects of ibuprofen promoting both redistribution of intracellular cholesterol and increased rates of microtubule reformation, while decreasing RhoA expression in CF epithelial cell models. Inhibiting ACC polymerization with citrate increases RhoA expression and decreases microtubule reformation rates in wild-type epithelial cells, suggesting pro-inflammatory signaling. Together, these findings demonstrate a novel mechanism of high-dose ibuprofen efficacy and point to a potential new therapeutic target for anti-inflammatory drugs in CF. Overall design: Compare broader impact of ACC inhibition on TOFA-treated (5-(Tetradecyloxy-2-furoic acid) CF HNE cells
Acetyl-CoA carboxylase inhibition regulates microtubule dynamics and intracellular transport in cystic fibrosis epithelial cells.
Sex, Age, Specimen part, Disease, Subject
View SamplesWe used RNA sequencing to identify differentially expressed genes during esophageal epithelial differentiation and in the presence of interleukin 13 using an air-liquid interface culture system. Overall design: RNA sequencing was performed on a human esophageal epithelial cell line (EPC2-hTERT) grown submerged (day 8) or at the air-liquid interface (ALI) (day 14, untreated or treated with interleukin 13 [100 ng/mL])
Eosinophilic esophagitis-linked calpain 14 is an IL-13-induced protease that mediates esophageal epithelial barrier impairment.
No sample metadata fields
View SamplesHow plants determine the final size of growing cells is an important, yet unanswered question. Root hairs provide an excellent model system to study this question since their final cell size is remarkably constant under given environmental conditions. In this study we demonstrate that a trihelix transcription factor GT-2-LIKE1 (GTL1) and its homolog DF1 repress root hair growth in Arabidopsis. Our transcriptional data, combined with genome-wide chromatin binding data, show that GTL1 and DF1 directly bind the RSL4 promoter and regulate its expression to repress root hair growth. Our data further show that GTL1 and RSL4 regulate each other as well as a set of common downstream genes, many of which have previously been implicated in root hair growth. This study therefore uncovers a core regulatory module that fine-tunes the extent of root hair growth by orchestrated actions of opposing transcription factors.
GTL1 and DF1 regulate root hair growth through transcriptional repression of <i>ROOT HAIR DEFECTIVE 6-LIKE 4</i> in <i>Arabidopsis</i>.
No sample metadata fields
View SamplesWounding is a primary trigger of organ regeneration but how wound stress reactivates cell proliferation and promotes cellular reprogramming remains elusive. In this study we combined the transcriptome analysis with quantitative hormonal analysis to investigate how wounding induces callus formation in Arabidopsis thaliana. Our time-course RNA-seq analysis revealed that wounding induces dynamic transcriptional changes that can be categorized into five clusters with distinct temporal patterns. Gene ontology analyses uncovered that wounding modifies the expression of hormone biosynthesis and response genes, and quantitative analysis of endogenous plant hormones revealed accumulation of cytokinin prior to callus formation. Mutants defective in cytokinin synthesis and signalling display reduced efficiency in callus formation, indicating that de novo synthesis of cytokinin has major contribution in wound-induced callus formation. We further demonstrate that type-A ARABIDOPSIS RESPONSE REGULATOR (ARR)-mediated cytokinin signalling regulates the expression of CYCLIN D3;1 (CYCD3;1) and mutations in CYCD3;1 and its homologs CYCD3;2-3 cause defects in callus formation. Our transcriptome data, in addition, showed that wounding activates multiple developmental regulators, and we found novel roles of ETHYLENE RESPONSE FACTOR 115 (ERF115) and PLETHORA3 (PLT3), PLT5, PLT7 in wound-induced callus formation. Together, this study provides novel mechanistic insights into how wounding reactivates cell proliferation during callus formation. Overall design: Examination of transcriptome at 0, 1, 3, 6, 12,24 h after wounding.
Wounding Triggers Callus Formation via Dynamic Hormonal and Transcriptional Changes.
Specimen part, Subject, Time
View SamplesDouble Hit Lymphoma (DHL) were treated with the BRD4 inhibitor 100 nM CPI203 for 6h
The BET bromodomain inhibitor CPI203 overcomes resistance to ABT-199 (venetoclax) by downregulation of BFL-1/A1 in in vitro and in vivo models of MYC+/BCL2+ double hit lymphoma.
Specimen part, Cell line, Subject
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