Atherosclerosis 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 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 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 SamplesMicroarray gene expression profiling of aorta genes of APOE-deficient mice receiving atherosclerosis treatment with the ACE inhibitor captopril.
Angiotensin-converting enzyme inhibition down-regulates the pro-atherogenic chemokine receptor 9 (CCR9)-chemokine ligand 25 (CCL25) axis.
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.
No associated publication
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.
No associated publication
Age, Specimen part, Disease, Treatment
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 SamplesExtracellular senile plaques of amyloid beta (Abeta) are a pathological hallmark in brain of patients with Alzheimer`s Disease (AD). Abeta is generated by the amyloidogenic processing of the amyloid precursor protein (APP). Concomitant to Abeta load, AD brain is characterized by an increase in protein level and activity of the angiotensin-converting enzyme (ACE). ACE inhibitors are a widely used class of drugs with established benefits for patients with cardiovascular disease. However, the role of ACE and ACE inhibition in the development of Abeta plaques and the process of AD-related neurodegeneration is not clear since ACE was reported to degrade Abeta. To investigate the effect of ACE inhibition on AD-related pathomechanisms, we used Tg2576 mice with neuron-specific expression of APPSwe as AD model. From 12 months of age, substantial Abeta plaque load accumulates in the hippocampus of Tg2576 mice as a brain region, which is highly vulnerable to AD-related neurodegeneration. The effect of central ACE inhibition was studied by treatment of 12 month-old Tg2576 mice for six months with the brain penetrating ACE inhibitor captopril. At an age of 18 months, hippocampal gene expression profiling was performed of captopril-treated Tg2576 mice relative to untreated 18 month-old Tg2576 controls with high Abeta plaque load. As an additional control, we used 12 month-old Tg2576 mice with low Abeta plaque load. Whole genome microarray gene expression profiling revealed gene expression changes induced by the brain-penetrating ACE inhibitor captopril, which could reflect the neuro-regenerative potential of central ACE inhibition.
ACE inhibition with captopril retards the development of signs of neurodegeneration in an animal model of Alzheimer's disease.
Sex, Age, Specimen part
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