TNF-a is increased in the synovial fluid of patients with rheumatoid arthritis and osteoarthritis. TNF-a activates MEK/ERK in chondrocytes; however the overall functional relevance of MEK/ERK to TNF-a-regulated gene expression in chondrocytes is unknown. Chondrocytes were treated with TNF-a with or without the MEK1/2 inhibitor U0126 for 24 h. Microarray analysis was used to identify genes regulated by TNF-a in a MEK1/2-dependent fashion.
Egr-1 inhibits the expression of extracellular matrix genes in chondrocytes by TNFalpha-induced MEK/ERK signalling.
No sample metadata fields
View SamplesInterleukin-6 (IL-6) is a proinflammatory cytokine that exerts a wide range of cellular, physiological and pathophysiological responses. Pyrrolidine dithiocarbamate (PDTC) antagonizes the cellular responsiveness to IL-6 through impairment in STAT3 activation and downstream signaling. Here, a transcriptional profiling was conducted as a basis for understanding the biological properties of PDTC in human HepG2 hepatocarcinoma cells. A global comparison of mRNA identified a highly significant difference of dysregulated gene expression transduced by PDTC versus IL-6 in HepG2 cells. Through an unbiased pathway analysis method, we have uncovered the mammalian target of rapamycin (mTOR) pathway together with rapid and dynamic alterations in REDD1 (regulated in development and DNA damage response 1) expression as one of the underlying molecular mechanisms responsible for IL-6 resistance to PDTC. Quantitative PCR and Western blot analyses validated the microarray data by showing the reciprocal pattern of REDD1 expression and subsequent mTOR inhibition after stimulation with PDTC relative to IL-6.
Impact of pyrrolidine dithiocarbamate and interleukin-6 on mammalian target of rapamycin complex 1 regulation and global protein translation.
Cell line
View SamplesAsthma pathogenesis and susceptibility involves a complex interplay between genetic and environmental factors.
Functional classes of bronchial mucosa genes that are differentially expressed in asthma.
Sex, Specimen part
View SamplesCaloric restriction (CR) without malnutrition is one of the most consistent strategies for increasing mean and maximal lifespan and delaying the onset of age-associated diseases. Stress resistance is a common trait of many long-lived mutants and life-extending interventions, including CR. Indeed, better protection against heat shock and other genotoxic insults have helped explain the pro-survival properties of CR. In this study, both in vitro and in vivo responses to heat shock were investigated using two different models of CR. Murine B16F10 melanoma cells treated with serum from CR-fed rats showed lower proliferation, increased tolerance to heat shock and enhanced HSP-70 expression, compared to serum from ad libitum-fed animals. Similar effects were observed in B16F10 cells implanted subcutaneously in male C57BL/6 mice subjected to CR. Microarray analysis identified a number of genes and pathways whose expression profile were similar in both models. These results suggest that the use of an in vitro model could be a good alternative to study the mechanisms by which CR exerts its anti-tumorigenic effects.
Caloric restriction induces heat shock response and inhibits B16F10 cell tumorigenesis both in vitro and in vivo.
Cell line, Treatment
View SamplesWe analyzed small RNAs from three mammalian species, and found that in all these species piRNA-directed targeting is accompanied by the generation of short sequences that have a very precisely defined length and a specific spatial relationship with the guide piRNAs. Overall design: small RNA-seq of testes lysate (beta-eliminated)
Conserved generation of short products at piRNA loci.
No sample metadata fields
View SamplesWe previously demonstrated that Th1Th17 cells are highly permissive to HIV-1, whereas Th1 cells are relatively resistant. Here, we investigated molecular mechanisms underlying these differences. Superior HIV replication in Th1Th17 vs. Th1 cells was regulated by entry and post-entry mechanisms.
Transcriptional profiling reveals molecular signatures associated with HIV permissiveness in Th1Th17 cells and identifies peroxisome proliferator-activated receptor gamma as an intrinsic negative regulator of viral replication.
Specimen part, Subject
View SamplesSmall RNAs, such as miRNAs and siRNAs, are involved in gene regulation in a variety of systems, including mouse oocytes. Dicer is a ribonuclease III enzyme essential for miRNA and siRNA biosynthesis. In an effort to uncover the function of small RNAs during oocyte growth, we specifically deleted Dicer in growing oocytes and analyzed the global pattern of gene expression in these Dicer-deficient oocytes.
MicroRNA activity is suppressed in mouse oocytes.
Sex, Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Mapping gene regulatory circuitry of Pax6 during neurogenesis.
Specimen part
View SamplesPax6 is a highly conserved transcription factor among vertebrates and is important in various aspects of the central nervous system (CNS) development. However, the gene regulatory circuitry of Pax6 underlying these functions remains elusive. We find that, following expression in neural progenitor cells, Pax6 targets many promoters embedded in an active chromatin environment. Intriguingly, many of these sites are also bound by another progenitor factor, Sox2, which cooperates with Pax6 in gene regulation. A combinatorial analysis of Pax6 binding dataset with transcriptome changes in Pax6-deficient neural progenitors reveals a dual role for Pax6, in which it activates the neuronal (ectodermal) genes while concurrently represses the mesodermal and endodermal genes thereby ensuring the unidirectionality of lineage commitment towards glutamatergic neuronal differentiation. Furthermore, Pax6 is critical for inducing activity of transcription factors that elicit neurogenesis and repress others that promote non-neuronal lineages. In addition to many established downstream effectors, Pax6 directly binds and activates a number of genes that are specifically expressed in neural progenitors but have not been previously implicated in neurogenesis. The in utero knockdown of one such gene, Ift74, during brain development impairs polarity and migration of new-born neurons. These findings demonstrate new aspects of the gene regulatory circuitry of Pax6, revealing how it functions to control neuronal development at multiple levels to ensure unidirectionality and proper execution of the neurogenic program.
Mapping gene regulatory circuitry of Pax6 during neurogenesis.
Specimen part
View SamplesNAD(P)H:quinone Oxidoreductase (NQO1) is essential for cell defense against reactive oxidative species, cancer, and metabolic stress. Recently, NQO1 was found in ribonucleoprotein (RNP) complexes, but NQO1-interacting mRNAs and the functional impact of such interactions are not known. Here, we used ribonucleoprotein immunoprecipitation (RIP) and microarray analysis to identify comprehensively the subset of NQO1 target mRNAs in human hepatoma HepG2 cells. One of its main targets, SERPINA1 mRNA, encodes the serine protease inhibitor -1-antitrypsin, A1AT, which is associated with disorders including obesity-related metabolic inflammation, chronic obstructive pulmonary disease (COPD), liver cirrhosis and hepatocellular carcinoma. Biotin pulldown analysis indicated that NQO1 can bind the 3 untranslated region (UTR) and the coding region (CR) of SERPINA1 mRNA. NQO1 did not affect SERPINA1 mRNA levels; instead, it enhanced the translation of SERPINA1 mRNA, as NQO1 silencing decreased the size of polysomes forming on SERPINA1 mRNA and lowered the abundance of A1AT. Luciferase reporter analysis further indicated that NQO1 regulates SERPINA1 mRNA translation through the SERPINA1 3UTR. Accordingly, NQO1-KO mice had reduced hepatic and serum levels of A1AT and increased activity of neutrophil elastase, one of the main targets of A1AT. We propose that this novel mechanism of action of NQO1 as RNA-binding protein may help to explain its pleiotropic biological effects.
Novel RNA-binding activity of NQO1 promotes SERPINA1 mRNA translation.
Specimen part, Cell line, Treatment
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