Recent studies have highlighted the role of adrenal corticosteroid signaling in cardiac physiology and pathophysiology. It is known that glucocorticoids and aldosterone are able to bind glucocorticoid receptor (GR) and mineralocorticoid receptor (MR), and these ligand-receptor interactions are redundant. Therefore, it has been impossible to delineate how these nuclear receptors couple with corticosteroid ligands and differentially regulate gene expression for operation of their distinct functions in the heart.
Ligand-based gene expression profiling reveals novel roles of glucocorticoid receptor in cardiac metabolism.
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View SamplesGlobal DNA hypomethylation and DNA hypermethylation of promoter regionsincluding tumor suppressor genesare frequently detected in human cancers. Although many studies have suggested a contribution to carcinogenesis, it is still unclear whether the aberrant DNA hypomethylation observed in tumors is a consequence or a cause of cancer. We found that overexpression of Stella (also known as PGC7, Dppa3), a maternal factor required for the maintenance of DNA methylation in early embryos, induced global DNA hypomethylation and transformation in NIH3T3 cells. This hypomethylation was due to the binding of Stella to Np95 (also known as Uhrf1, ICBP90) and the subsequent impairment of Dnmt1 localization. In addition, enforced expression of Stella enhanced the metastatic ability of B16 melanoma cells through the induction of metastasis-related genes by inducing DNA hypomethylation of their promoter regions. Such DNA hypomethylation itself causes cellular transformation and metastatic ability. These data provide new insight into the function of global DNA hypomethylation in carcinogenesis.
Global DNA hypomethylation coupled to cellular transformation and metastatic ability.
Cell line
View SamplesWnt/-catenin is involved in every aspect of embryonic development and in the pathogenesis of many human diseases, and is also implicated in organ fibrosis. However, the role of -catenin-mediated signaling on liver fibrosis remains unclear. To explore this issue, the effects of PRI-724, a selective inhibitor of the cAMP-response element-binding protein-binding protein (CBP)/-catenin interaction, on liver fibrosis were examined using carbon tetrachloride (CCl4)- or bile duct ligation (BDL)-induced mouse liver fibrosis models. Following repetitive CCl4 administrations, the nuclear translocation of -catenin was observed only in the non-parenchymal cells in the liver. PRI-724 treatment reduced the fibrosis induced by CCl4 or BDL, accompanied by the suppression of S100A4 expression, a CBP/-catenin transcript. C-82, an active form of PRI-724, inhibited the activation of isolated primary mouse quiescent hepatic stellate cells (HSCs) and promoted cell death in culture-activated HSCs. During the fibrosis resolution period, an increase in F4/80+ CD11b+ and Ly6Clow CD11b+ macrophages was induced by CCl4 and was sustained for two weeks thereafter, even after having stopped CCl4 treatment. PRI-724 accelerated the resolution of CCl4-induced liver fibrosis, and this was accompanied by increased matrix metalloproteinase (MMP)-9, MMP-2, and MMP-8 expression in intrahepatic leukocytes. These results suggest that the inhibition of CBP/-catenin suppresses liver fibrosis through the inhibition of HSCs activation, the induction of activated HSC death, and the production of MMPs from macrophages. Thus, targeting the CBP/-catenin interaction may become a new therapeutic strategy in treating liver fibrosis.
No associated publication
Treatment
View SamplesDe novo lipogenesis is activated in most cancers. Several lipogenic enzymes are implicated in oncogenesis and represent potential cancer therapeutic targets. RNA interference-mediated depletion of ATP citrate lyase (ACLY), the enzyme that catalyzes the first step of de novo lipogenesis, leads to growth suppression in a subset of human cancer cells. Here we demonstrate the molecular basis and potential biomarkers for ACLY-targeting therapy. First, suppression of cancer cell growth by ACLY depletion involves down-regulation of fatty acid elongase ELOVL6 at the transcriptional level. Lipid profiling revealed that ACLY depletion alters fatty acid composition in triglyceride; increased palmitate and decreased longer fatty acids, in accordance with ELOVL6 down-regulation. Second, ACLY depletion increases reactive oxygen species (ROS), whereas addition of antioxidant reduces ROS and attenuates the growth suppression. Third, ACLY depletion or ROS stimulation induce phosphorylation of AMP-activated protein kinase (AMPK), a sensor of energy and lipid metabolism. Analysis of various cancer cell lines revealed that the levels of AMPK phosphorylation (p-AMPK) correlate with the basal ROS levels, and that cancer cells with low basal p-AMPK (i.e., low basal ROS) levels are highly susceptible to ACLY depletion-mediated growth suppression. Finally, in clinical colon cancer tissues, p-AMPK levels are significantly decreased in aggressive tumors and correlate with the levels of 8-hydroxydeoxyguanosine, a hallmark of ROS stimulation. Together, these data suggest that ACLY inhibition suppresses cancer growth via palmitate-mediated lipotoxicity, and p-AMPK could be a predictive biomarker for its therapeutic outcome.
No associated publication
Specimen part, Cell line
View SamplesNeural stem cells (NSCs) are considered to be the cell-of-origin of brain tumor stem cells. To identify the genetic pathways responsible for the transformation of normal NSCs to brain-tumor-initiating cells, we used Sleeping Beauty (SB) transposons, to mutagenize NSCs. Mobilized SB transposons induced the immortalization of NSCs. Immortalized NSCs induced tumors upon subcutaneous transplantation in immunocompromized mice. To further classify the immortalized cells and mouse tumors, we performed Gene Set Enrichment Analysis (GSEA) using DNA microarray data.
Transposon mutagenesis identifies genes that transform neural stem cells into glioma-initiating cells.
Specimen part
View SamplesGeneChip Mouse Gene 2.0 ST Array was used to comprehensively investigate the changes of gene expression of small intestinal myofibroblasts of mice after stimulation with homogenates of intestinal eosinophils in vitro.
Eosinophil depletion suppresses radiation-induced small intestinal fibrosis.
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View SamplesTo understand the role of prostaglandin (PG) receptor EP2 (Ptger2) signaling in ovulation and fertilization, we investigated time-dependent expression profiles in wild-type (WT) and Ptger2-/- cumuli before and after ovulation by using microarrays.
Expression profiling of cumulus cells reveals functional changes during ovulation and central roles of prostaglandin EP2 receptor in cAMP signaling.
Sex, Specimen part
View SamplesRationale Electroconvulsive seizure (ECS) therapy is a nonchemical treatment for depression. Since ECS up-regulates expression of c-Fos in the paraventricular nucleus of hypothalamus (PVN), the function of which is frequently influenced in depression, we hypothesized that ECS modulates functions of the PVN and contributes to its antidepressant effects. Objectives To identify gene expression changes in the mouse PVN by ECS treatment Material and methods First, we established a method to amplify nucleotides from small quantities of RNA. Mice received one shock of ECS and their brains were collected at 2 or 6 h after shock. The PVN was microdissected from dehydrated brain sections, its total RNA was extracted and microarray analysis was applied. Results At 2 h after ECS, 2.6% (589 genes) of the probes showed more than 2-fold decrease, and 0.9% (205 genes) showed more than 2-fold increase. To confirm the expression changes, genes showing differential expression with a wide range in the microarray were analyzed by qPCR. Among the genes with more than 2-fold change by ECS, down-regulated 94 genes and up-regulated 24 genes have been reported the association with anxiety, bipolar disorder or mood disorder by the Ingenuity knowledge database. The groups of down-regulated genes, which are suggested to modulate the function of the PVN or associate to psychiatric disorders, include neuropeptides (Cck), kinases (Prkcb, Prkcc, Camk2a), transcription factors (Bcl6, Tbr1), transporters (Aqp4) and others (Fmr1). Conclusion The present results indicate that ECS treatment can modulate the functions of PVN via a series of gene expression changes, and may contribute to its antidepressant effects at least in part.
Electroconvulsive seizure-induced changes in gene expression in the mouse hypothalamic paraventricular nucleus.
Specimen part, Treatment, Time
View SamplesThe ventromedial nucleus of the hypothalamus (VMH) is thought to a satiety center and a potential target for anti-obesity therapy. Electroconvulsive seizure (ECS) therapy is highly effective in psychiatric diseases including depression, but also implicated beneficial effects on other neurological diseases. Although it has been reported that the neurons in the VMH are strongly activated by ECS stimulation, the effect of ECS in this hypothalamic subnucleus remains unknown. To address this issue, we investigated molecular changes in the VMH in response to ECS by utilizing a method of laser-capture microdissection coupled with microarray analysis, and examined behavioral effects of ECS via VMH activation. ECS significantly induced gene expression not only immediate-early genes such as Fos, Fosb and Jun, but also Bdnf, Adcyap1, and Hrh1 in the VMH after a single or repeated stimulus.
No associated publication
Specimen part, Treatment
View SamplesTranscriptome analysis of LPS-stimulated bone marrow-derived dendritic cells with NR4A3 gene silencing
The Orphan Nuclear Receptor NR4A3 Is Involved in the Function of Dendritic Cells.
Specimen part
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