MicroRNA studies in in vitro and in vivo activated rat hepatic stellate cells: Emphasis on miR-146a
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ABSTRACT:
ORGANISM(S): Rattus norvegicus
SUBMITTER: jinmiao chen
PROVIDER: E-GEOD-19463 | biostudies-arrayexpress |
REPOSITORIES: biostudies-arrayexpress
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Project description:pHSCs were isolated from Wistar rats and cultivated in cell culture flasks. The miRNA was isolated at day 0 and 10 and hybridized onto the Ncode Multi-species miRNA microarray V2 from Invitrogen 3 samples from different rats were analyzed on miRNA microarray performing dye swap
2010-05-18 | E-GEOD-19462 | biostudies-arrayexpress
Project description:Hypoxia is one of the major driving forces mediating tumor angiogenesis, aggressiveness, as well as resistance to chemo- and radiotherapy. It has also been suggested to play important roles in stem cell maintenance for both normal and cancer tissues. However, the mechanisms by which hypoxia-driven epigenetic changes modulate tumorigenesis remain poorly understood. As the histone H3 lysine 9 (H3K9) demethylase Jmjd1a and methyltransferase G9a are upregulated downstream targets of hypoxia, we focused on these two catalytically opposing epigenetic modifiers to address this question. Through the use of homozygous Jmjd1a and G9a knockout mouse embryonic stem (ES) cells, we found that Jmjd1a was not required for stem cell self-renewal and that anti-angiogenesis related genes were epigenetically dysregulated in both Jmjd1a- and G9a deficient ES cells under hypoxic conditions, accompanied by corresponding changes in H3K9 dimethylation and H3K4 trimethylation levels in the proximal promoter regions of these target genes. Most importantly, these genetic alterations led to opposing tumor phenotypes: loss of Jmjd1a results in increased tumor growth, whereas loss of G9a produces smaller tumors. These findings provide new insights on the importance of hypoxia signalling in regulating the epigenetic status and expression of angiogenesis genes that promote tumor progression. 63 microarray samples consisting of 7 mouse ES cell lines of which 2 are wild type (control), 2 Jmjd1a knockout, 2 G9a knockout and 1 G9a knockout that was reconstituted for G9a (G9a control). Each cell line and condition was seeded at 3 different densities (2X10^5, 4X10^5 and 6X10^5) in 6 cm dishes to control for the effects of cell confluency on gene expression. 18 hours after plating, the cells were subjected to normoxia (21% O2) for 24 hours (control), normoxia 20 hours followed by hypoxia (1% O2) for 4 hours (acute hypoxia) and 24 hours hypoxia (chronic treatment). Total RNA was harvested from all samples for microarrays after the 24 hour treatments.
2014-07-30 | E-GEOD-35061 | biostudies-arrayexpress
Project description:HSC-2 (hepatic stellate cells line from rat) were stably transfected with rno-miR-146a. Three different clones were selected (S1, S4, S5). We used Affymetrix rat genome RAT230 2.0 chip to monitor global transcriptome changes. Two passages of each sample were used. Control - HSC-2 and GFPscr.
2009-12-07 | E-GEOD-19354 | biostudies-arrayexpress
Project description:MicroRNA expression was assayed from bronchial epithelial cells collected via bronchoscopy from healthy current and never smoker volunteers in order to determine the effect of cigarette smoke exposure on airway epithelial microRNA expression Keywords: Global microRNA expression profiling Bronchial epithelial cells were collected from current and never smokers via bronchoscopy. Low molecular weight RNA ( < 200 nucleotides) was isolated and hybridized to Invitrogen NCode microRNA microarrays to determine which microRNAs detected in bronchial epithelial cells were differentially expressed in the airways of smokers.
2009-01-28 | E-GEOD-14634 | biostudies-arrayexpress
Project description:Background: Chronic obstructive pulmonary disease (COPD) is a heterogeneous disease characterized by varying degrees of emphysematous lung destruction and small airway disease, each with distinct effects on clinical outcomes. There is little known about how microRNAs contribute specifically to the emphysema phenotype. We examined how microRNA expression is altered with regional emphysema severity within the lung and how these microRNAs regulate disease-associated gene-expression networks. Results: We profiled microRNAs in different regions in the lung with varying degrees of emphysema from 6 smokers with COPD and 2 controls (8 regions x 8 lungs = 64 samples). 63 microRNAs (p<0.05) were altered with regional emphysema severity as quantified by mean linear intercept (Lm). MicroRNA and gene expression data were then integrated in the same samples. A subset of microRNAs, including miR-638, miR-30c, and miR-181d, correlated with many of their predicted gene targets, suggesting a role in regulating the gene networks that underlie emphysematous lung destruction. Modulating miR-638 expression in primary human lung fibroblasts recapitulated the alterations in its targeted gene-expression network associated with emphysema progression. Pathway analysis revealed that genes involved in oxidative stress and accelerated aging were affected by miR-638 knock-down in fibroblasts. Many miR-638 gene targets in these pathways were amongst those negatively correlated with miR-638 expression in emphysematous lung tissue. Conclusions: Our findings demonstrate that microRNAs are altered with regional emphysema severity and modulate disease-associated gene expression networks. Furthermore, miR-638 may regulate gene expression associated with the oxidative stress response and aging in emphysematous lung tissue and fibroblasts. Paired samples were obtained from 8 regions at regular intervals between the apex and base of each explanted lung from six patients with severe COPD and two donors. The degree of emphysematous destruction was quantified in one sample from each region by mean linear intercept (Lm), while microRNA expression was profiled in the adjacent sample from the same region using the NCode Version 3 microRNA microarrays (Invitrogen, Carlsbad, CA). After quality control 60 samples were used for the analysis.
2013-12-31 | E-GEOD-49881 | biostudies-arrayexpress
Project description:Embryonic stem (ES) cells continuously decide whether to maintain pluripotency or differentiate. While exogenous LIF and BMP4 perpetuate a pluripotent state, less is known about factors initiating differentiation. We show that heparan sulfate (HS) proteoglycans are critical co-receptors for signals inducing ES cell differentiation. Genetic targeting of NDST1 and 2, two enzymes required for N-sulfation of proteoglycans, blocked differentiation. This phenotype was rescued by HS presented in trans or by soluble heparin. NaClO3-, which reduces sulfation of proteoglycans, potently blocked differentiation of wild type cells. Mechanistically, N-sulfation was identified to be critical for functional autocrine FGF4 signalling. Micro array analysis identified the pluripotency maintaining transcription factors Nanog, KLF2/4/8, Tbx3 and Tcf3 to be negatively regulated, whereas markers of differentiation such as Gbx2, Dnmt3b, FGF5 and Brachyury were induced by sulfation-dependent-FGFR signalling. We show that several of these genes are heterogeneously expressed in ES cells and targeting of heparan sulfation or FGFR-signalling facilitated a homogenous Nanog/KLF4/Tbx3 positive ES cell state. This finding suggests that the recently discovered heterogeneous state of ES cells is regulated by HS-dependent FGFR signalling. Similarly, culturing blastocysts with NaClO3- eliminated GATA6 positive primitive endoderm progenitors generating a homogenous Nanog positive inner cell mass. Functionally, reduction of sulfation robustly improved de novo ES cell derivation efficiency. We conclude that N-sulfated HS is required for FGF4 signalling to maintain ES cells primed for differentiation in a heterogeneous state. Inhibiting this pathway facilitates a more naïve ground state. Four groups with three biological replicates and a technical duplicate in each
2010-04-09 | E-GEOD-15974 | biostudies-arrayexpress
Project description:HAMLET triggers a p38- and ER stress-dependent death response in carcinoma cells. Transcriptome and proteome analysis detected an increase in p38 expression and phosphorylation exclusively in carcinoma cells and p38 inhibitors delayed the death response to HAMLET in carcinoma and lymphoma cells. ER stress gene expression was also increased in tumor cells and HAMLET triggered rapid XBP1 mRNA splicing, eIF2a phosphorylation, and ATF6 cleavage as well as Hsc70 and CHOP activation, suggesting that ER stress caused by HAMLET may trigger p38 phosphorylation and death. The p38 inhibitor reduced the transcription of both p38 and ER stress gene transcription. Healthy differentiated cells, in contrast, showed no alteration in p38 signaling but a rapid innate immune response was detected and the cells survived HAMLET challenge. 2 cell lines, time course, HAMLET treatment
2010-08-24 | E-GEOD-23772 | biostudies-arrayexpress
Project description:Nodal and Activin are morphogens of the TGFbeta superfamily of signaling molecules that direct differential cell fate decisions in a dose- and distance-dependent manner. During early embryonic development the Nodal/Activin pathway is responsible for the specification of mesoderm, endoderm, node and mesendoderm. In contradiction to this drive towards cellular differentiation, the pathway also plays important roles in the maintenance of self-renewal and pluripotency in embryonic and epiblast stem cells. The molecular basis behind stem cell interpretation of Nodal/Activin signaling gradients and the undertaking of disparate cell fate decisions remains poorly understood. Here, we show that any perturbation of endogenous signaling levels in mouse ES cells leads to their exit from self renewal towards divergent differentiation programs. Increasing Nodal signals above basal levels by direct stimulation with Activin promotes differentiation towards the mesendodermal lineages while repression of signaling with the specific Nodal/Activin receptor inhibitor SB431542 induces trophectodermal differentiation. To address how quantitative Nodal/Activin signals are translated qualitatively into distinct cell fates decisions, we performed chromatin immunoprecipitation of phospho-Smad2 the primary downstream transcriptional factor of the Nodal/Activin pathway followed by massively parallel sequencing and show that phospho-Smad2 binds to and regulates distinct subsets of target genes in a dose-dependent manner. Crucially, Nodal/Activin signaling directly controls the Oct4 master regulator of pluripotency by graded phospho-Smad2 binding in the promoter region. Hence stem cells interpret and carry out differential Nodal/Activin signaling instructions via a corresponding gradient of Smad2 phosphorylation that selectively titrates self-renewal against alternative differentiation programs by direct regulation of distinct target gene subsets and Oct4 expression. Four biological replicates consisting of 4 different passages of E14TG2a ES cells at P20, P21, P23 and P24
2011-06-30 | E-GEOD-23239 | biostudies-arrayexpress
Project description:The Aryl hydrocarbon Receptor (AhR) is a signal regulated transcription factor, which is canonically activated by the direct binding of xenobiotics. In addition, switching cells from adherent to suspension culture also activates the AhR, representing a non-xenobiotic, physiological activation of AhR signaling. Here, we show that the AhR is recruited to target gene enhancers in both ligand (YH439) treated and suspension cells, suggesting a common mechanism of target gene induction between these two routes of AhR activation. However, gene expression profiles critically differ between xenobiotic and suspension activated AhR signaling. Por, and Cldnd1 were regulated predominately by ligand treatments, while in contrast, ApoER2 and Ganc were regulated predominately by the suspension condition. Classic xenobiotic metabolizing AhR targets such as Cyp1a1, Cyp1b1, and Nqo1 were regulated by both ligand and suspension conditions. Temporal expression patterns of AhR target genes were also found to vary, with examples of transient activation, transient repression, or sustained alterations in expression. Furthermore, sequence analysis coupled with ChIP assays and reporter gene analysis identified a functional XRE (xenobiotic response element) within the mouse Tiparp gene that features a concatemer of 4 XRE cores (GCGTG) residing in the first intron ~1.2kb downstream of the Tiparp transcription start site. Our data suggest that this XRE concatemer site concurrently regulates the expression of both Tiparp gene and its cis anti-sense non-coding RNA following ligand or suspension induced AhR activation. This work lends novel insights into how AhR signaling drives different transcriptional programs via the ligand versus suspension modes of activation. Reference: Murray IA et al. (2005) Evidence that ligand binding is a key determinant of Ah receptor-mediated transcriptional activity. Arch Biochem Biophys 442(1):59-71. Reference: Monk SA et al. (2001) Transient expression of CYP1A1 in rat epithelial cells cultured in suspension. Arch Biochem Biophys 393(1):154-162. Reference: Chua SW et atl. (2006) A novel normalization method for effective removal of systematic variation in microarray data. Nucleic acids research 34(5):e38. 18 microarray samples consisting of AhR null and reconstituted hepatocytes subjected to 10M-NM-<M YH439, 0.1% DMSO carrier control or grown in suspension culture for 8 hours in 3 biologial replicates.
2012-08-09 | E-GEOD-37144 | biostudies-arrayexpress
Project description:ABL1 kinase inhibitors such as imatinib mesylate (IM) are effective in managing chronic myelogenous leukemia (CML) but incapable of eliminating leukemia stem cells (LSCs), suggesting that kinaseM-bM-^HM-^Rindependent pathways support LSC survival. Given that the bone marrow hypoxic microenvironment supports hematopoietic stem cells, we investigated if hypoxia similarly contributes to LSC persistence. Importantly, we found that while BCRM-bM-^HM-^RABL1 kinase remained effectively inhibited by IM under hypoxia, apoptosis became partially suppressed. Furthermore, hypoxia enhanced the clonogenicity of CML cells, as well as their efficiency in repopulating immunodeficient mice, both in the presence and absence of IM. HIF1M-bM-^HM-^RM-NM-1, which is the master regulator of the hypoxia transcriptional response is expressed in the bone marrow specimens of CML individuals. In vitro, HIF1M-bM-^HM-^RM-NM-1 is stabilized during hypoxia and its expression and transcriptional activity can be partially attenuated by concurrent IM treatment. Expression analysis demonstrates at the whole transcriptome level that hypoxia and IM regulate distinct subsets of genes. Functionally, knockdown of HIF1M-bM-^HM-^RM-NM-1 abolished the enhanced clonogenicity during hypoxia. Taken together, our results suggest that in the hypoxic microenvironment, HIF1M-bM-^HM-^RM-NM-1 signaling supports LSC persistence independently of BCRM-bM-^HM-^RABL1 kinase activity. Thus targeting HIF1M-bM-^HM-^RM-NM-1 and its pathway components may be therapeutically important for the complete eradication of LSCs. 24 samples consisting CD34+ bone marrow aspirates of 3 chronic phase patients that were subjected to 24h or 96h of DMSO/Normoxia (21% oxygen, 5% carbon dioxide) control, 2 M-BM-5M Imatinib, hypoxia (0.5% oxygen, 5% carbon dioxide) or combined Imatinib/hypoxia treatments in triplicate cultures.
2014-06-03 | E-GEOD-48294 | biostudies-arrayexpress