We used Arabidopsis full-genome microarrays to characterize plant transcript accumulations at different stages of infection with the biotrophic oomycete downy mildew pathogen, Hyaloperonospora arabidopsidis : initiation (< 1 dpi) and maintenance of infection (> 4 dpi).
An Arabidopsis (malectin-like) leucine-rich repeat receptor-like kinase contributes to downy mildew disease.
Specimen part
View SamplesWe used Arabidopsis full-genome microarrays to characterize plant transcript accumulations in map65-3 and ugt76b1 mutants, 3 days after water treatment and inoculation with the biotrophic oomycete downy mildew pathogen, Hyaloperonospora arabidopsidis (Hpa)
The Arabidopsis microtubule-associated protein MAP65-3 supports infection by filamentous biotrophic pathogens by down-regulating salicylic acid-dependent defenses.
Specimen part, Time
View SamplesWe used Arabidopsis full-genome microarrays to characterize plant transcript accumulations in wild-type plants and pskr1-5 mutants, 3 days after water treatment and inoculation with the biotrophic oomycete downy mildew pathogen, Hyaloperonospora arabidopsidis.
Evolutionarily distant pathogens require the Arabidopsis phytosulfokine signalling pathway to establish disease.
Specimen part
View SamplesThe ubiquitously expressed G-protein-coupled receptor kinase 2 (GRK2, ADRBK1) is an indispensable kinase involved in growth, differentiation and development. Exaggerated GRK2 activity plays a major pathophysiological role in the development of cardiovascular diseases such as heart failure and hypertension. GRK2 exerts its functions by kinase-dependent and kinase-independent effects. To assess the differential impact of GRK2 on cellular signalling we established HEK cell clones with over-expression of comparable protein levels of GRK2 or the kinase-deficient GRK2-K220R mutant, respectively. HEK cells were either cultured in vitro or expanded in vivo, in immunodeficient NOD.Scid mice to discriminate between in vitro and in vivo effects of GRK2. Whole genome microarray gene expression profiling was performed of cultured HEK cells and of NOD.Scid mouse-expanded HEK clones. As an additional control, cells were re-cultured in vitro after expansion in NOD.Scid mice.
Inhibition of G-protein-coupled receptor kinase 2 (GRK2) triggers the growth-promoting mitogen-activated protein kinase (MAPK) pathway.
Specimen part
View SamplesPhytophthora cinnamomi is a devastating soil-borne oomycete with a very broad host range however there remains a major gap in the understanding of plant resistance responses to the pathogen, furthermore, necrotrophic plant-pathogen interactions, particularly those of root pathogens, remain poorly understood. Zea mays exhibits non-host resistance to the pathogen and has been well characterised as a model species. Using the maize Affymetrix GeneChip array we conducted genome-wide gene expression profiling to elucidate the defence genes and pathways which are induced in the root tissue of a resistant plant species to the pathogen.
Transcriptional profiling of Zea mays roots reveals roles for jasmonic acid and terpenoids in resistance against Phytophthora cinnamomi.
Specimen part, Time
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 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 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 fatty acid synthase (FASN) is the major fat synthesizing enzyme. FASN is an indispensable enzyme because mice with genetic deletion of Fasn are not viable. Apart from its physiological function, previous studies indicated that FASN could also exert a pathophysiological role, in the heart, because patients with heart failure showed up-reguation of FASN. To investigate the in vivo function of FASN up-regulation in the heart, we generated mice with myocardium-specific expression of FASN under control of the alpha-MHC promoter. Two different founder lines were generated with high and low FASN over-expression. Microarray gene expression profiling of heart tissue was performed of heart tissue from transgenic mice with high and low FASN expression
Inhibition of G-protein-coupled Receptor Kinase 2 Prevents the Dysfunctional Cardiac Substrate Metabolism in Fatty Acid Synthase Transgenic Mice.
Sex, Specimen part
View SamplesGamma-herpesviruses encode a cytoplasmic mRNA-targeting endonuclease, termed SOX, that cleaves the majority of mRNAs within a cell. Cleaved fragments are subsequently degraded by the cellular mRNA degradation machinery. Here, we reveal that mammalian cells respond to this widespread cytoplasmic mRNA decay by altering levels of RNA polymerase II (RNAPII) transcription in the nucleus. Measurements of both RNAPII recruitment to promoters and nascent mRNA synthesis revealed that the majority of affected genes are transcriptionally repressed in SOX-expressing cells. The transcriptional feedback does not occur in response to the initial endonuclease-induced cleavage, but instead to degradation of the cleaved fragments by cellular exonucleases. In particular, Xrn1 catalytic activity is required for transcriptional repression. Notably, viral mRNA transcription escapes decay-induced repression, and this escape requires Xrn1. Collectively, these results indicate that mRNA decay rates impact transcription in mammalian cells, and that gamma-herpesviruses have incorporated this feedback mechanism into their own gene expression strategy. Overall design: NIH 3T3 cells were mock, WT, or ?HS infected with MHV68 in duplicate and 4sU-labeled RNA isolated. 4sU-labeled RNA was submitted for sequencing and reads aligned to the mouse genome or MHV68 viral genome. Differential cellular gene expression was determined between mock and WT infected, mock and ?HS infected, as well as differential viral gene expression between WT and ?HS.
Viral Nucleases Induce an mRNA Degradation-Transcription Feedback Loop in Mammalian Cells.
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