Double-stranded RNA (dsRNA) can enter different pathways in mammalian cells, including sequence-specific RNA interference, sequence-independent interferon response and editing by adenosine deaminases. To assess the potential of expressed dsRNA to induce interferon stimulated genes in somatic cells, we performed microarray analysis of HEK293 and HeLa cells transfected with a MosIR plasmid expressing an mRNA with a long inverted repeat structure in its 3UTR (MosIR) or with a parental MosIR plasmid (without inverted repeat) as a control.
dsRNA expression in the mouse elicits RNAi in oocytes and low adenosine deamination in somatic cells.
Specimen part
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The mammalian TRIM-NHL protein TRIM71/LIN-41 is a repressor of mRNA function.
Specimen part, Cell line
View SamplesWe identify mammalian TRIM71 as repressor of mRNAs that inhibits translation and affects mRNA stability.
The mammalian TRIM-NHL protein TRIM71/LIN-41 is a repressor of mRNA function.
Cell line
View SamplesWe identify mammalian TRIM71 as repressor of mRNAs that inhibits translation and affects mRNA stability. In this data set we compare the expression profile of mouse ES upon Trim71 KD versus that of the parental cells.
The mammalian TRIM-NHL protein TRIM71/LIN-41 is a repressor of mRNA function.
Specimen part
View SamplesHepatitis C virus (HCV) infection is a major cause of chronic liver disease worldwide. The current standard therapy for chronic hepatitis C (CHC) consists of a combination of pegylated IFN alpha (pegIFN-alpha) and ribavirin. It achieves a sustained viral clearance in only 5060% of patients. To learn more about molecular mechanisms underlying treatment failure, we investigated IFN-induced signaling in paired liver biopsies collected from CHC patients before and after administration of pegIFN-alpha. In patients with a rapid virological response to treatment, pegIFN-alpha induced a strong up-regulation of IFN-stimulated genes (ISGs). As shown previously, nonresponders had high expression levels of ISGs before therapy. Analysis of posttreatment biopsies of these patients revealed that pegIFN-alpha did not induce expression of ISGs above the pretreatment levels. In accordance with ISG expression data, phosphorylation, DNA binding, and nuclear localization of STAT1 indicated that the IFN signaling pathway in nonresponsive patients is preactivated and refractory to further stimulation. Some features characteristic of nonresponders were more accentuated in patients infected with HCV genotypes 1 and 4 compared with genotypes 2 and 3, providing a possible explanation for the poor response of the former group to therapy. Taken together with previous findings, our data support the concept that activation of the endogenous IFN system in CHC not only is ineffective in clearing the infection but also may impede the response to therapy, most likely by inducing a refractory state of the IFN signaling pathway.
Interferon signaling and treatment outcome in chronic hepatitis C.
No sample metadata fields
View SamplesWe have analyzed the transcript expression levels in Dicer heterozygous and Dicer knock-out embryonic stem (ES) cells in order to identify which transcripts are regulated by RNAi pathway in mouse ES cells.
MicroRNAs control de novo DNA methylation through regulation of transcriptional repressors in mouse embryonic stem cells.
No sample metadata fields
View SamplesWe have analyzed the transcript expression levels in Dicer knock-out embryonic stem (ES) cells 24 hours after transfection with either control siRNA agains Renilla luciferase or miRNA Mimics (Dharmacon) of mmu-miR-290 cluster members in order to identify primary targets of miR-290 cluster miRNAs.
MicroRNAs control de novo DNA methylation through regulation of transcriptional repressors in mouse embryonic stem cells.
No sample metadata fields
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Interferon-γ-stimulated genes, but not USP18, are expressed in livers of patients with acute hepatitis C.
Specimen part, Disease, Disease stage, Treatment, Subject, Time
View SamplesApproximately 50% of patients with chronic hepatitis C (CHC) have a sustained virologic response (SVR) to treatment with pegylated interferon (pegINF)- and ribavirin. Non-response to treatment is associated with constitutively increased expression of IFN-stimulated genes (ISGs) in the liver. Treatment of patients with acute hepatitis C (AHC) is more effective, with SVR rates >90%. We investigated mechanisms of the different responses of patients with CHC and AHC to pegIFN- therapy. We analyzed IFN signaling and ISG expression in liver samples from patients with acute hepatitis C (AHC), patients with chronic hepatitis (CHC), and individuals without hepatitis C (controls) using microarray, immunohistochemical, and protein analyses. Findings were compared with those from primary human hepatocytes stimulated with IFN- or IFN-, as reference sets. Expression levels of 100s of genes, primarily those regulated by IFN-, were altered in liver samples from patients with AHC compared with controls. Expression of IFN-stimulated genes was induced in liver samples from patients with AHC, whereas expression of IFN-stimulated genes was induced in samples from patients with CHC. In an expression analysis of negative regulators of IFN- signaling, we did not observe differences in expression of SOCS1 or SOCS3 between liver samples from patients with AHC and those with CHC. However, USP18 (another negative regulator of IFN- signaling), was upregulated in liver samples of patients with CHC that did not respond to therapy, but not in AHC. In conclusion, differences in expression of ISGs might account for the greater response of patients with AHC, compared to those with CHC, to treatment with pegINF- and ribavirin. Specifically, USP18 is upregulated in liver samples of patients with CHC that do not respond to therapy, but not in patients with AHC.
Interferon-γ-stimulated genes, but not USP18, are expressed in livers of patients with acute hepatitis C.
Specimen part, Treatment, Subject, Time
View SamplesApproximately 50% of patients with chronic hepatitis C (CHC) have a sustained virologic response (SVR) to treatment with pegylated interferon (pegINF)- and ribavirin. Non-response to treatment is associated with constitutively increased expression of IFN-stimulated genes (ISGs) in the liver. Treatment of patients with acute hepatitis C (AHC) is more effective, with SVR rates >90%. We investigated mechanisms of the different responses of patients with CHC and AHC to pegIFN- therapy. We analyzed IFN signaling and ISG expression in liver samples from patients with acute hepatitis C (AHC), patients with chronic hepatitis (CHC), and individuals without hepatitis C (controls) using microarray, immunohistochemical, and protein analyses. Findings were compared with those from primary human hepatocytes stimulated with IFN- or IFN-, as reference sets. Expression levels of 100s of genes, primarily those regulated by IFN-, were altered in liver samples from patients with AHC compared with controls. Expression of IFN-stimulated genes was induced in liver samples from patients with AHC, whereas expression of IFN-stimulated genes was induced in samples from patients with CHC. In an expression analysis of negative regulators of IFN- signaling, we did not observe differences in expression of SOCS1 or SOCS3 between liver samples from patients with AHC and those with CHC. However, USP18 (another negative regulator of IFN- signaling), was upregulated in liver samples of patients with CHC that did not respond to therapy, but not in AHC. In conclusion, differences in expression of ISGs might account for the greater response of patients with AHC, compared to those with CHC, to treatment with pegINF- and ribavirin. Specifically, USP18 is upregulated in liver samples of patients with CHC that do not respond to therapy, but not in patients with AHC.
Interferon-γ-stimulated genes, but not USP18, are expressed in livers of patients with acute hepatitis C.
Specimen part, Disease, Disease stage
View Samples