Cre recombinase-mediated conditional knockout of floxed Dicer1 alleles causes depletion of small RNAs including microRNAs, which function to repress target mRNA expression by inhibiting translation and/or stimulating mRNA degradation.
MicroRNA-183 family expression in hair cell development and requirement of microRNAs for hair cell maintenance and survival.
Specimen part
View SamplesmRNA and microRNA expression was examined in global cellular fractions and in RNA-induced silencing complex (RISC)-immunoprecipitated cell fractions in cultured primary human astrocytes (ScienCell) and in cultured human U-87 MG astrocytoma cells (ATCC). ABSTRACT: Background: GW/P bodies are cytoplasmic ribonucleoprotein-rich foci that are involved in microRNA (miRNA)-mediated messenger RNA (mRNA) silencing and degradation. These mRNA regulatory functions within GW/P bodies are mediated by GW182 and its binding partner hAgo2 when bound to miRNA within the RNA-induced silencing complex (RISC). Although miRNAs and mRNAs are known to be localized to RISC in a variety of cells, to date no published study has examined the profile of specific miRNA and mRNA targeted to the RISC. Methodology/Principle Findings: In this study, RISC mRNA and miRNA components were profiled by microarray analysis of human U-87 astrocytoma cells and primary human astrocytes with total RNA extracted from the RISC as well as the global cellular fractions. The novel findings of this study were fourfold: (1) miRNAs are highly enriched in primary astrocyte RISC compared to U-87 astrocytoma RISC, (2) astrocytoma cells and primary astrocytes each contain unique RISC miRNA profiles as compared to their respective cellular miRNA profiles, (3) miR-195, 10b, 29b, 19b, 34a and 455-3p were upregulated and miR-181b was downregulated in U-87 astrocytoma RISC as compared to primary astrocyte RISC, and (4) RISC contain mostly downregulated mRNAs in primary astrocytes and U-87 astrocytoma cells. Conclusions/Significance: We show that in U-87 astrocytoma cells, miR-34a and miR-195 were upregulated in RISC suggesting an oncogenic role for these miRNAs. Three miR34a-targeted mRNAs and two miR-195-targeted mRNAs were downregulated. One miR-195-targeted mRNA was upregulated. Biological pathway analysis of RISC mRNA components suggests that the RISC plays a pivotal role in cancer, inflammatory disease, immunological disease, the cell cycle, cellular movement and numerous cell signaling pathways. This study points to the importance of the RISC and ultimately GW/P body composition and function and in miRNA and mRNA deregulation in astrocytoma cells and possibly for other brain tumors.
The microRNA and messengerRNA profile of the RNA-induced silencing complex in human primary astrocyte and astrocytoma cells.
Cell line
View SamplesThe Mrp8 and Mrp14 proteins (calprotectin) accumulate within tissues during aging and may contribute to chronic inflammation. To address this possibility, we evaluated calprotectin-deficient Mrp14-KO and wild-type (WT) mice at 5 and 24 months of age. However, there was no evidence that age-related inflammation is blunted in KO mice. Inflammation makers were in fact elevated in livers from old KO mice, and microarray analysis revealed more consistent elevation of genes specifically expressed by B-cells and T-cells. Adipose-specific genes, however, were less consistently elevated in aged KO mice, suggesting an anti-steatosis effect of Mrp8/14 deficiency. Consistent with this, genes decreased by the anti-steatosis agent SRT1720 were decreased in old KO compared to old WT mice. Expression of lipid metabolism genes was altered in KO mice at 5 months of age, along with genes associated with development, biosynthesis and immunity. These early-age effects of Mrp8/14 deficiency, in the absence of any external stressor, were unexpected. Taken together, our findings demonstrate a pro-steatosis rather than pro-inflammatory role of calprotectin within the aging liver. This appears to reflect a developmental-metabolic phenotype of Mrp14-KO mice that is manifest at a young age in the absence of pro-inflammatory stimuli.
Deficiency of myeloid-related proteins 8 and 14 (Mrp8/Mrp14) does not block inflammaging but prevents steatosis.
Specimen part
View SamplesUnderstanding the mechanisms of host macrophage responses to Mycobacterium tuberculosis (M.tb.) is essential for uncovering potential avenues of intervention to boost host resistance to infection. Macrophage transcriptome profiling revealed M.tb. infection strongly induced expression of several enzymes controlling tryptophan (Trp) catabolism. This included indole 2,3-dioxygenase 1 (IDO1) and tryptophan 2,3-dioxygenase (TDO2), which catalyze the rate-limiting step in the kynurenine pathway, producing ligands for the aryl hydrocarbon receptor (AHR). The AHR and heterodimeric partners AHR nuclear translocator (ARNT) and RELB are robustly expressed, and AHR and RELB levels further increased during infection. Infection enhanced AHR/ARNT and AHR/RELB DNA binding, and stimulated expression of AHR target genes, including that encoding the inflammatory cytokine IL1beta. AHR target gene expression was further enhanced by exogenous kynurenine, and exogenous Trp, kynurenine or synthetic agonist indirubin reduced mycobacterial viability. Comparative expression profiling revealed that AHR ablation diminished expression of numerous genes implicated in innate immune responses, including several cytokines. Notably, AHR depletion reduced expression of IL23A and IL12B transcripts, which encode subunits of interleukin 23 (IL23), a macrophage cytokine that stimulates production of IL22 by innate lymphoid cells. The AHR directly induced IL23A transcription in human and mouse macrophages through near-upstream enhancer regions. Taken together, these findings show that AHR signaling is strongly engaged in Mtb-infected macrophages, and has widespread effects on innate immune responses. Moreover, they reveal a cascade of AHR-driven innate immune signaling, as IL1B (IL-1) and IL23 stimulate T cell subsets producing IL22, another direct target of AHR transactivation.
Engagement of the Aryl Hydrocarbon Receptor in Mycobacterium tuberculosis-Infected Macrophages Has Pleiotropic Effects on Innate Immune Signaling.
Cell line
View SamplesTo reveal distinct transcriptomes associated with spermatogonial stem cell renewal vs. initiation of differentiation, single-cell transcriptomes from Adult Human spermatogonia were subdivided into subpopulations based on the levels of ID4 mRNA (determined in this experiment). This correlates with distinct fates of corresponding mouse spermatogonia when assayed by transplantation, with ID4-EGFPbright cells highly enriched for SSCs, and ID4-EGFPdim cells enriched for progenitors. We used the Fluidigm C1 instrument to capture individual spermatogonia for SMART-Seq2 single-cell RNA-seq. Overall design: Nine replicate preparations of Adult Human spermatogonia were used for this study. Data are from a total of 635 cells. Cells were binned into quartiles according to ID4 mRNA levels (Q1 = ID4-high, Q4=ID4-low, Q2 and Q3 have intermediate ID4 mRNA levels) to facilitate comparisons.
The Mammalian Spermatogenesis Single-Cell Transcriptome, from Spermatogonial Stem Cells to Spermatids.
Specimen part, Subject
View SamplesTo reveal distinct transcriptomes associated with spermatogonial stem cell renewal vs. initiation of differentiation, single-cell transcriptomes from Adult ID4-EGFP+ spermatogonia were subdivided into subpopulations that displayed distinct fates when assayed by transplantation, with ID4-EGFPbright cells highly enriched for SSCs, and ID4-EGFPdim cells enriched for progenitors. We used the Fluidigm C1 instrument to capture individual spermatogonia for SMART-Seq2 single-cell RNA-seq. Overall design: Four replicate preparations of Adult mouse ID4-EGFP+ spermatogonia were used for this study. Data are from a total of 300 cells. Cells were binned into quartiles according to EGFP epifluorescence intensity (Q1 = EGFP-bright, Q4=EGFP-dim, Q2 and Q3 have intermediate EGFP fluorescence) to facilitate comparisons.
The Mammalian Spermatogenesis Single-Cell Transcriptome, from Spermatogonial Stem Cells to Spermatids.
Specimen part, Subject
View SamplesTo reveal distinct transcriptomes associated with spermatogonial stem cell renewal vs. initiation of differentiation, single-cell transcriptomes from P6 ID4-EGFP+ spermatogonia were subdivided into subpopulations that displayed distinct fates when assayed by transplantation, with ID4-EGFPbright cells highly enriched for SSCs, and ID4-EGFPdim cells enriched for progenitors. We used the Fluidigm C1 instrument to capture individual spermatogonia for SMART-Seq2 single-cell RNA-seq. Overall design: Five replicate preparations of mouse P6 ID4-EGFP+ spermatogonia were used for this study. Data are from a total of 278 cells. Cells were binned into quartiles according to EGFP epifluorescence intensity (Q1 = EGFP-bright, Q4=EGFP-dim, Q2 and Q3 have intermediate EGFP fluorescence) to facilitate comparisons.
The Mammalian Spermatogenesis Single-Cell Transcriptome, from Spermatogonial Stem Cells to Spermatids.
Specimen part, Subject
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Gene Regulatory Network Inference of Immunoresponsive Gene 1 (IRG1) Identifies Interferon Regulatory Factor 1 (IRF1) as Its Transcriptional Regulator in Mammalian Macrophages.
Specimen part
View SamplesImmunoresponsive gene 1 (IRG1) is one of the highest induced genes in macrophages under pro-inflammatory conditions and its function has been recently described: it codes for immune-responsive gene 1 protein/cis-aconitic acid decarboxylase (IRG1/CAD), an enzyme catalyzing the production of itaconic acid from cis-aconitic acid, a tricarboxylic acid (TCA) cycle intermediate. Itaconic acid possesses specific antimicrobial properties inhibiting isocitrate lyase, the first enzyme of the glyoxylate shunt, an anaplerotic pathway that bypasses the TCA cycle and enables bacteria to survive on limited carbon conditions. To elucidate the mechanisms underlying itaconic acid production through IRG1 induction in macrophages, we examined the transcriptional regulation of IRG1. Using a combination of literature information, transcription factor prediction models and genome-wide expression arrays, we inferred the regulatory network of IRG1 in mouse and human macrophages.
Gene Regulatory Network Inference of Immunoresponsive Gene 1 (IRG1) Identifies Interferon Regulatory Factor 1 (IRF1) as Its Transcriptional Regulator in Mammalian Macrophages.
Specimen part
View SamplesImmunoresponsive gene 1 (IRG1) is one of the highest induced genes in macrophages under pro-inflammatory conditions and its function has been recently described: it codes for immune-responsive gene 1 protein/cis-aconitic acid decarboxylase (IRG1/CAD), an enzyme catalyzing the production of itaconic acid from cis-aconitic acid, a tricarboxylic acid (TCA) cycle intermediate. Itaconic acid possesses specific antimicrobial properties inhibiting isocitrate lyase, the first enzyme of the glyoxylate shunt, an anaplerotic pathway that bypasses the TCA cycle and enables bacteria to survive on limited carbon conditions. To elucidate the mechanisms underlying itaconic acid production through IRG1 induction in macrophages, we examined the transcriptional regulation of IRG1. Using a combination of literature information, transcription factor prediction models and genome-wide expression arrays, we inferred the regulatory network of IRG1 in mouse and human macrophages.
Gene Regulatory Network Inference of Immunoresponsive Gene 1 (IRG1) Identifies Interferon Regulatory Factor 1 (IRF1) as Its Transcriptional Regulator in Mammalian Macrophages.
Specimen part
View Samples