C/EBPb is an auto-repressed protein that becomes posttranslationally activated by Ras-MEK-ERK signalling. C/EBPb is required for oncogene-induced senescence (OIS) of primary fibroblasts, but also displays pro-oncogenic functions in many tumour cells. Here, we show that C/EBPb activation by H-RasV12 is suppressed in immortalized/transformed cells, but not in primary cells, by its 30 untranslated region (30UTR). 30UTR sequences inhibited Ras-induced cytostatic activity of C/EBPb, DNA binding, transactivation, phosphorylation, and homodimerization, without significantly affecting protein expression. The 30UTR suppressed induction of senescence-associated C/EBPb target genes, while promoting expression of genes linked to cancers and TGFb signalling. An AU-rich element (ARE) and its cognate RNA-binding protein, HuR, were required for 30UTR inhibition. These components also excluded the Cebpb mRNA from a perinuclear cytoplasmic region that contains activated ERK1/2, indicating that the site of C/EBPb translation controls de-repression by Ras signalling. Notably, 30UTR inhibition and Cebpb mRNA compartmentalization were absent in primary fibroblasts, allowing Ras-induced C/EBPb activation and OIS to proceed. Our findings reveal a novel mechanism whereby non-coding mRNA sequences selectively regulate C/EBPb activity and suppress its anti-oncogenic functions.
3'UTR elements inhibit Ras-induced C/EBPβ post-translational activation and senescence in tumour cells.
Cell line
View SamplesThe anti-diabetic drug and agonist of the peroxisome proliferator-activated receptor gamma (Pparg), rosiglitazone, was recently withdrawn in many countries because the drug use was associated with an increased risk of heart failure. To investigate underlying pathomechanisms, we chose 6-month-old apolipoprotein E (apoE)-deficient mice, which are prone to atherosclerosis and insulin resistance, and thereby mimic the risk profile of patients with cardiovascular disease. After 8 weeks of rosiglitazone treatment (30 mg/kg/day), echocardiography and histology analyses demonstrated that rosiglitazone had induced heart failure with cardiac dilation. Concomitantly, cardiac lipid overload and lipid-induced cardiomyocyte death developed. The microarray gene expression study of heart tissue from rosiglitazone-treated apoE-deficient mice relative to untreated apoE-deficient mice and non-transgenic B6 mice identified cardiac Pparg-dependent lipid metabolism genes in rosiglitazone-treated mice, which seem to trigger a major heart failure promoting pathway.
Inhibition of G-protein-coupled Receptor Kinase 2 Prevents the Dysfunctional Cardiac Substrate Metabolism in Fatty Acid Synthase Transgenic Mice.
Age, Specimen part, Treatment
View SamplesHypercholesterolemic APOE-deficient mice are a widely used experimental model of atherosclerosis and increased generation of reactive oxygen species (ROS) is a prominent feature of atherosclerosis development. To study the impact of ROS on atherogenesis, we treated APOE-deficient mice for 7 months with the antioxidant vitamin E (2000 IU/kg diet) and performed whole genome microarray gene expression profiling of aortic genes. Microarray gene expression profiling was performed of whole aortas isolated from vitamin E-treated APOE-deficient relative to untreated APOE-deficient mice with overt atherosclerosis, and nontransgenic B6 control mice. Microarray gene expression profiling revealed that vitamin E treatment prevented atherosclerosis-related gene expression changes of the aortic intima and media.
Microarray gene expression profiling reveals antioxidant-like effects of angiotensin II inhibition in atherosclerosis.
Specimen part, Disease, Treatment
View SamplesThe Raf kinase inhibitor protein (RKIP) is a dual inhibitor of the Raf kinase and the G-protein-coupled receptor kinase 2 (GRK2). GRK2 is an indispensable kinase, which exerts a major role in the pathogenesis of heart failure, and inhibition of GRK2 is cardioprotective in experimental models of heart failure. To investigate the cardiac function of RKIP as GRK2 inhibitor, we generated transgenic mice with myocardium-specific expression of RKIP under control of the alpha-MHC promoter. For comparison, mice with myocardium-specific expression of a GRK-specific peptide inhibitor (GRK-Inh) were also generated. Two different transgenic mouse models were established. Transgenic RKIP mice and transgenic GRK-Inh mice were born at Mendelian frequencey and grew to adulthood normally.
Inhibition of G-protein-coupled receptor kinase 2 (GRK2) triggers the growth-promoting mitogen-activated protein kinase (MAPK) pathway.
Sex, Age, Specimen part
View SamplesAtherosclerosis and pressure overload are major risk factors for the development of heart failure in patients. Cardiac hypertrophy often precedes the development of heart failure. However, underlying mechanisms are incompletely understood. To investigate pathomechanisms underlying the transition from cardiac hypertrophy to heart failure we used experimental models of atherosclerosis- and pressure overload-induced cardiac hypertrophy and failure, i.e. apolipoprotein E (apoE)-deficient mice, which develop heart failure at an age of 18 months, and non-transgenic C57BL/6J (B6) mice with heart failure triggered by 6 months of pressure overload induced by abdominal aortic constriction (AAC). The development of heart failure was monitored by echocardiography, invasive hemodynamics and histology. The microarray gene expression study of cardiac genes was performed with heart tissue from failing hearts relative to hypertrophic and healthy heart tissue, respectively. The microarray study revealed that the onset of heart failure was accompanied by a strong up-regulation of cardiac lipid metabolism genes involved in fat synthesis, storage and oxidation.
Up-regulation of the cardiac lipid metabolism at the onset of heart failure.
Age, Specimen part, Disease
View SamplesHeart failure is a leading cause of cardiovascular mortality with limited options for treatment. We used 18 month-old apolipoprotein E (apoE)- deficient mice as a model of atherosclerosis-induced heart failure to analyze whether the anti-ischemic drug ranolazine could retard the progression of heart failure. The study showed that 2 months of ranolazine treatment improved cardiac function of 18 month-old apoE-deficient mice with symptoms of heart failure as assessed by echocardiography. To identify changes in cardiac gene expression induced by treatment with ranolazine a microarray study was performed with heart tissue from failing hearts relative to ranolazine-treated and healthy control hearts. The microarray approach identified heart failure-specific genes that were normalized during treatment with the anti-ischemic drug ranolazine.
Up-regulation of the cardiac lipid metabolism at the onset of heart failure.
Age, Specimen part, Disease, Treatment
View SamplesHeart failure is a leading cause of cardiovascular mortality with limited options for treatment. We analyzed whether the anti-ischemic drug ranolazine could retard the progression of heart failure in an experimental model of heart failure induced by 6 months of chronic pressure overload. The study showed that 2 months of ranolazine treatment improved cardiac function of aortic constricted C57BL/6J (B6) mice with symptoms of heart failure as assessed by echocardiography. The microarray gene expression study of heart tissue from failing hearts relative to ranolazine-treated and healthy control hearts identified heart failure-specific genes that were normalized during treatment with the anti-ischemic drug ranolazine.
Up-regulation of the cardiac lipid metabolism at the onset of heart failure.
Age, Specimen part, Disease, Treatment
View SamplesDepletion of cardiac ATP content is a characteristic feature of heart failure in patients and experimental animal models. To analyze the impact of insufficient ATP supply on heart function we inhibited cellular respiration by disulfide poisoning with the mild thiol-blocking agent, cystamine. We chose 4 month-old apolipoprotein E (apoE)-deficient mice, which are highly vulnerable to increased oxygen and ATP demands. After 4 weeks of cystamine treatment (300 mg/kg in drinking water), echocardiography and histology analyses demonstrated that apoE-deficient mice had developed heart failure with cardiac dilation. The microarray gene expression study of heart tissue from cystamine-treated apoE-deficient mice relative to untreated mice confirmed the development of heart failure showing up-regulation heart failure-specific genes by mild thiol-blocking with cystamine.
Up-regulation of the cardiac lipid metabolism at the onset of heart failure.
Age, Specimen part, Disease, Treatment
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Network analysis of skin tumor progression identifies a rewired genetic architecture affecting inflammation and tumor susceptibility.
Sex
View SamplesGene expression in self-renewing epithelial tissues is controlled by cis- and trans-activating regulatory factors that mediate responses to exogenous agents capable of causing tissue damage, infection, inflammation, or tumorigenesis. We used network construction methods to analyze the genetic architecture of gene expression in normal mouse skin in a cross between tumor-susceptible Mus musculus and tumor-resistant Mus spretus. We demonstrate that gene expression motifs representing different constituent cell types within the skin such as hair follicle cells, haematopoietic cells, and melanocytes are under separate genetic control. Motifs associated with inflammation, epidermal barrier function and proliferation are differentially regulated in mice susceptible or resistant to tumor development. The intestinal stem cell marker Lgr5 is identified as a candidate master regulator of hair follicle gene expression, and the Vitamin D receptor (Vdr) links epidermal barrier function, inflammation, and tumor susceptibility.
Genetic architecture of mouse skin inflammation and tumour susceptibility.
No sample metadata fields
View Samples