Project description:Atria and ventricles exhibit distinct molecular profiles that produce structural and functional differences between the two cardiac compartments. However, factors that determine these differences remain largely undefined. Cardiomyocyte-specific COUP- TFII ablation produces ventricularized atria that exhibit ventricle-like action potentials, increased cardiomyocyte size, and development of extensive T-tubules. We used microarrays to examine the molecular profile of cardiomyocyte-specific COUP-TFII knockout adult atria in comparison with that of normal atria. We extracted RNA from mutant right atria, control right atria and control ventricles from 2 months old adult mice, followed by gene expression profiling using Affymetrix microarrays.
Project description:Atria and ventricles exhibit distinct molecular profiles that produce structural and functional differences between the two cardiac compartments. However, factors that determine these differences remain largely undefined. Cardiomyocyte-specific COUP- TFII ablation produces ventricularized atria that exhibit ventricle-like action potentials, increased cardiomyocyte size, and development of extensive T-tubules. We used microarrays to examine the molecular profile of cardiomyocyte-specific COUP-TFII knockout adult atria in comparison with that of normal atria.
Project description:Pharmacological and gene ablation studies have demonstrated a crucial role of the caridac natriuretic peptides (NP) hormones ANF and BNP in the maintenance of cardiovascular homeostasis. Considerable effort has been focused on the elucidation of the mechanistic underlying increased atrial ANF and BNP expression and secretion. These investigations are important because under chronic congestive heart failure, the secretion of NPs although increased and beneficial, is relatively insufficient as demonstrated by the fact that patients benefit form the unloading of the heart induced by therapeutic administration of either ANF or BNP. To identify genes involved in the transcriptional response of the endocrine heart under normal and stimulated states, we conducted differential gene expression studies of the rat atria and ventricles under normal or chronic volume overload, induced by aorto-caval shunt. The left atrial appendages and left ventricular free walls were obtained from 28 day sham and shunt operated male Sprague Dawley rats. Total RNA was obtained from three pools (of two tissues) of left atria and left ventricles under sham and shunt conditions. Three biological replicates for each muscle type and condition were generated.
Project description:Objectives: The primary objective of this high-resolution proteomic study was to investigate patients with severe aortic valve stenosis (AVS) to detect novel biomarkers for diagnostic and/or therapeutic purposes. Background: Among patients with severe AVS, some are likely to rapidly progress with a higher mortality and benefit from prompt surgical or interventional care. To select these patients, novel disease-related biomarkers are needed. Methods: We used induced pluripotent stem cell derived cardiomyocytes as a relative quantification standard to profile the proteomes of formalin-fixed paraffin-embedded (FFPE) atria and left ventricles from 30 patients with AVS. Results: In total, 3370 proteins were quantified using high-resolution mass spectrometry. Statistical analysis revealed significant upregulation of 64 proteins in the atria and 27 proteins in the ventricles including several known chamber specific marker-proteins. Atrial upregulation of proteins that belong to the interstitial compartment or contribute to endocrine function was observed. To uncover disease related proteins, we compared our data to similar published datasets from healthy and diseased hearts. We performed gene set enrichment analyses to pinpoint global proteomic characteristics of a decompensated state of AVS with hypertrophy, like the downregulation of ventricular mitochondrial proteins and the development of ventricular fibrosis. Finally, we propose a set of high abundant proteins like LGALS3BP, TUBA4A, TINAGL1 and LAMA2 as well as SRL, FHL1 and ATP2A2 playing a crucial role in AVS-related heart disease. Conclusions: We established a reproducible workflow for high-resolution quantitative proteomics of FFPE myocardial samples and provide interesting candidate proteins with biomarker potential for AVS.
Project description:Background: Lamins A/C (encoded by the LMNA gene) can lead to dilated cardiomyopathy (DCM). Objectives: This study sought to undertake proteomic analysis of myocardial tissue to explore the postgenomic phenotype of end-stage lamin heart disease. Methods: Consecutive patients with end-stage lamin heart disease (LMNA-group, n=7) and ischaemic DCM (ICM-group, n=7) undergoing heart transplantation were enrolled. Samples were obtained from left atrium(LA), left ventricle(LV), right atrium(RA), right ventricle(RV) and interventricular septum(IVS). Liquid chromatography combined with mass-spectrometry was used for protein quantification. We compared protein concentrations in cardiac samples between LMNA and ICM groups. Proteins were considered differentially abundant if the quantitative difference was 1.5-fold and corrected p-value <0.05 at a false discovery rate of 0.01. Gene ontology(GO) enrichment analysis explored the related biological processes. Results: 4,247 proteins were identified in LMNA and ICM samples, of which 633 were differentially abundant in LA, 39 in LV, 181 in RA, 52 in RV, and 85 in IVS. Abundance of lamin A/C was reduced but lamin B (LMNB) increased in LMNA LA/RA tissue compared to ICM, but not in LV/RV. Transthyretin was more abundant in the LV/RV of LMNA compared to ICM while sarcomeric proteins such as titin and cardiac myosin heavy chain were generally reduced in RA/LA of LMNA. Protein expression profiling and GO enrichment analysis revealed sarcopenia, extracellular matrix(ECM) remodeling, deficient myocardial energetics, redox imbalances, and abnormal calcium handling in LMNA samples. Conclusion: Lamin heart disease is a biventricular and biatrial disease, characterized by sarcopenia, aberrant metabolism, and ECM remodeling. LMNB and transthyretin were unexpectedly abundant in the atria and ventricles respectively of patients with end-stage lamin heart disease potentially hinting to the possibility of compensatory responses.
Project description:Purpose: The goal of this study was to characterize the atrial and ventricular transcriptomic changes in a cardiac mouse model of myotonic dystrophy. The mouse model utilizes a bitransgenic system for doxycycline (dox) inducible and cardiomyocyte specific expression of pathogenic RNA containing 960 CUG repeats. Bitransgenic animals (called CUG960 mice) homozygous for the TREDT960I transgene (containing 960 interrupted CTG repeats) and hemizygous for reverse transactivator (rtTA) transgene containing a cardiomyocyte-specific alpha myosin heavy chain promoter are given dox food for expression of CUG repeat RNA. Mice hemizygous for rtTA transgene (MHCrtTA) given dox food were used as controls. Methods:We performed RNA-seq for high-resolution analysis of transcriptomic alterations in atria and ventricles of CUG960 experimental and MHCrtTA control mice given dox chow since postnatal day 1 (PN1) for a period of 10 weeks. Results: We identified pathogenic CUG repeat RNA induced gene expression and alternative splicing changes in ion transport genes that are associated with inherited cardiac conduction diseases, including a subset of genes involved in calcium handling. Conclusions: We identified potential tissue-specific mechanisms contributing to the cardiac disease relevant phenotypes in an animal model of DM1.
Project description:GSE2240 contains two different experimental subsets: 1) Comparison of atrial and ventricular gene expression (atrial tissue of patients with sinus rhythm vs. human left ventricular non-failing myocardium) The purpose of our investigation was to identify the transcriptional basis for ultrastructural and functional specialization of human atria and ventricles. Using exploratory microarray analysis (Affymetrix U133A+B), we detected 11,740 transcripts expressed in human heart, representing the most comprehensive report of the human myocardial transcriptome to date. Variation in gene expression between atria and ventricles accounted for the largest differences in this data set, as 3.300 and 2.974 transcripts showed higher expression in atria and ventricles, respectively. Functional classification based on Gene Ontology identified chamber-specific patterns of gene expression and provided molecular insights into the regional specialization of cardiomyocytes, correlating important functional pathways to transcriptional activity: Ventricular myocytes preferentially express genes satisfying contractile and energetic requirements, while atrial myocytes exhibit specific transcriptional activities related to neurohumoral function. In addition, several pro-fibrotic and apoptotic pathways were concentrated in atrial myocardium, substantiating the higher susceptibility of atria to programmed cell death and extracellular matrix remodelling observed in human and experimental animal models of heart failure. Differences in transcriptional profiles of atrial and ventricular myocardium thus provide molecular insights into myocardial cell diversity and distinct region-specific adaptations to physiological and pathophysiological conditions (Barth AS et al., Eur J Physiol, 2005). 2) Comparison of atrial gene expression in patients with permanent atrial fibrillation and sinus rhythm. Atrial fibrillation is associated with increased expression of ventricular myosin isoforms in atrial myocardium, regarded as part of a dedifferentiation process. Whether re-expression of ventricular isoforms in atrial fibrillation is restricted to transcripts encoding for contractile proteins is unknown. Therefore, this study compares atrial mRNA expression in patients with permanent atrial fibrillation to atrial mRNA expression of patients with sinus rhythm as well as to ventricular gene expression using Affymetrix U133 arrays. In atrial myocardium, we identified 1.434 genes deregulated in atrial fibrillation, the majority of which, including key elements of calcium-dependent signaling pathways, displayed down-regulation. Functional classification based on Gene Ontology provided the specific gene sets of the interdependent processes of structural, contractile and electrophysiological remodeling. In addition, we demonstrate for the first time a prominent up-regulation of transcripts involved in metabolic activities, suggesting an adaptive response to an increased metabolic demand in fibrillating atrial myocardium. Ventricular-predominant genes were five times more likely to be up-regulated in atrial fibrillation (174 genes up-regulated, 35 genes down-regulated), while atrial-specific transcripts were predominantly down-regulated (56 genes up-regulated, 564 genes down-regulated). Overall, in atrial myocardium, functional classes of genes characteristic of ventricular myocardium were found to be up-regulated (e.g. metabolic processes) while functional classes predominantly expressed in atrial myocardium were down-regulated in atrial fibrillation (e.g. signal transduction and cell communication). Therefore, dedifferentiation with adoption of a ventricular-like signature is a general feature of the fibrillating atrium, uncovering the transcriptional response pattern in pmAF (Barth AS et al., Circ Res, 2005). Keywords = human myocardium Keywords = atrial fibrillation Keywords = sinus rhythm Keywords = left ventricular gene expression Keywords: other
Project description:Note this data set has identical data files: Files GSM40994.txt and GSM40995.txt. GSE2240 contains two different experimental subsets:; 1) Comparison of atrial and ventricular gene expression (atrial tissue of patients with sinus rhythm vs. human left ventricular non-failing myocardium); The purpose of our investigation was to identify the transcriptional basis for ultrastructural and functional specialization of human atria and ventricles. Using exploratory microarray analysis (Affymetrix U133A+B), we detected 11,740 transcripts expressed in human heart, representing the most comprehensive report of the human myocardial transcriptome to date. Variation in gene expression between atria and ventricles accounted for the largest differences in this data set, as 3.300 and 2.974 transcripts showed higher expression in atria and ventricles, respectively. Functional classification based on Gene Ontology identified chamber-specific patterns of gene expression and provided molecular insights into the regional specialization of cardiomyocytes, correlating important functional pathways to transcriptional activity: Ventricular myocytes preferentially express genes satisfying contractile and energetic requirements, while atrial myocytes exhibit specific transcriptional activities related to neurohumoral function. In addition, several pro-fibrotic and apoptotic pathways were concentrated in atrial myocardium, substantiating the higher susceptibility of atria to programmed cell death and extracellular matrix remodelling observed in human and experimental animal models of heart failure. Differences in transcriptional profiles of atrial and ventricular myocardium thus provide molecular insights into myocardial cell diversity and distinct region-specific adaptations to physiological and pathophysiological conditions (Barth AS et al., Eur J Physiol, 2005). 2) Comparison of atrial gene expression in patients with permanent atrial fibrillation and sinus rhythm. Atrial fibrillation is associated with increased expression of ventricular myosin isoforms in atrial myocardium, regarded as part of a dedifferentiation process. Whether re-expression of ventricular isoforms in atrial fibrillation is restricted to transcripts encoding for contractile proteins is unknown. Therefore, this study compares atrial mRNA expression in patients with permanent atrial fibrillation to atrial mRNA expression of patients with sinus rhythm as well as to ventricular gene expression using Affymetrix U133 arrays. In atrial myocardium, we identified 1.434 genes deregulated in atrial fibrillation, the majority of which, including key elements of calcium-dependent signaling pathways, displayed down-regulation. Functional classification based on Gene Ontology provided the specific gene sets of the interdependent processes of structural, contractile and electrophysiological remodeling. In addition, we demonstrate for the first time a prominent up-regulation of transcripts involved in metabolic activities, suggesting an adaptive response to an increased metabolic demand in fibrillating atrial myocardium. Ventricular-predominant genes were five times more likely to be up-regulated in atrial fibrillation (174 genes up-regulated, 35 genes down-regulated), while atrial-specific transcripts were predominantly down-regulated (56 genes up-regulated, 564 genes down-regulated). Overall, in atrial myocardium, functional classes of genes characteristic of ventricular myocardium were found to be up-regulated (e.g. metabolic processes) while functional classes predominantly expressed in atrial myocardium were down-regulated in atrial fibrillation (e.g. signal transduction and cell communication). Therefore, dedifferentiation with adoption of a ventricular-like signature is a general feature of the fibrillating atrium, uncovering the transcriptional response pattern in pmAF (Barth AS et al., Circ Res, 2005).
Project description:Pharmacological and gene ablation studies have demonstrated a crucial role of the caridac natriuretic peptides (NP) hormones ANF and BNP in the maintenance of cardiovascular homeostasis. Considerable effort has been focused on the elucidation of the mechanistic underlying increased atrial ANF and BNP expression and secretion. These investigations are important because under chronic congestive heart failure, the secretion of NPs although increased and beneficial, is relatively insufficient as demonstrated by the fact that patients benefit form the unloading of the heart induced by therapeutic administration of either ANF or BNP. To identify genes involved in the transcriptional response of the endocrine heart under normal and stimulated states, we conducted differential gene expression studies of the rat atria and ventricles under normal or chronic volume overload, induced by aorto-caval shunt.
Project description:We study the role of glycosylation in ion channel function. Specfically, we are focusing on how ion channel glycosylation modulates, controls, and impacts cardiac, skeletal muscle, and neuronal electrical activity. We wish to determine differences in gene expression through development and between the atria and ventricles of the mouse heart. Our data indicate differential sialylation directly affects voltage-gated sodium channel function through the developing heart in a chamber-specific manner. We wish to expand our findings to include other ion channels involved in the cardiac action potential, and to eventually create a map of the cardiac conduction system that details the role of differential glycosylation in cardiac excitability. Determining differential expression of the genes that regulate ion channel glycosylation is vital to these goals. We analyzed four sets of pooled RNA to be run in triplicate: one each from neonatal and adult mouse atria and ventricles.