Project description:Background: Chronic atrial fibrillation (AF) is a complication associated with the dilated atria of patients with valvular heart disease and contributes to worsened pathology. Methods and Results: Using microarray technology, we examined microRNA (miR) expression profiles in right and left atrial appendage tissue from valvular heart disease (VHD) patients. Right atrial appendage from patients undergoing coronary artery bypass grafting (CABG) and left atrial (LA) appendage from healthy hearts not used for transplant were used as controls. VHD induced different changes in miR expression in LA compared with right atria (RA). Fifty-two (52) miRs were altered by VHD in LA, compared with 5 in RA tissue. There was no detectable effect of chronic AF on miR expression in LA tissue, but miR expression in RA was strongly influenced by AF, with 47 miRs showing differential expression. LA volume correlated with miR expression changes in both LA and RA, but the affected miRs were different for the two atrial groups. Conclusions: VHD and AF influence miR expression patterns in LA and RA, but these are affected differently by disease progression and by the development of AF. These findings provide new insights into the progression of VHD. RA tissue is not a useful surrogate for LA in studies of mitral valve disease. 34 arrays from either the left or right atrium from patients with Valvular Heart Disease (VHD), patients undergoing coronary artery bypass grafting (CABG), or healthy controls. Arrays in this series were generated on V2 and V3 Agilent microRNA arrays and analysed in combination.
Project description:Background: Chronic atrial fibrillation (AF) is a complication associated with the dilated atria of patients with valvular heart disease and contributes to worsened pathology. Methods and Results: Using microarray technology, we examined microRNA (miR) expression profiles in right and left atrial appendage tissue from valvular heart disease (VHD) patients. Right atrial appendage from patients undergoing coronary artery bypass grafting (CABG) and left atrial (LA) appendage from healthy hearts not used for transplant were used as controls. VHD induced different changes in miR expression in LA compared with right atria (RA). Fifty-two (52) miRs were altered by VHD in LA, compared with 5 in RA tissue. There was no detectable effect of chronic AF on miR expression in LA tissue, but miR expression in RA was strongly influenced by AF, with 47 miRs showing differential expression. LA volume correlated with miR expression changes in both LA and RA, but the affected miRs were different for the two atrial groups. Conclusions: VHD and AF influence miR expression patterns in LA and RA, but these are affected differently by disease progression and by the development of AF. These findings provide new insights into the progression of VHD. RA tissue is not a useful surrogate for LA in studies of mitral valve disease.
Project description:Background: Atrial fibrillation (AF) causes atrial remodeling, and the left atrium (LA) is the favored substrate for maintaining AF. However, it remains unclear if AF remodels both atria differently and contributes to LA arrhythmogenesis and thrombogenesis. Results: AF was associated with differential LA-to-RA gene expression related to specific ion channels and pathways as well as upregulation of thrombogenesis-related genes in the LA appendage. Targeting the molecular mechanisms underlying the LA-to-RA difference and AF-related remodeling in the LA appendage may help provide new therapeutic options in treating AF and preventing thromboembolism in AF. Paired left atrial and right atrial specimens were obtained from 13 patients with persistent AF receiving valvular surgery. The Paired specimens were sent for microarray comparison. Selected results were validated by quantitative real time-PCR (q-PCR) and Western blotting. Ultrastructural changes in the atria were evaluated by immunohistochemistry.
Project description:Next Generation RNA Sequencing was carried out on human paired left and right atrial appendages from patients with and without Atrial Fibrillation. EdgeR software was used to show a total of 247 genes were found to have significant differential expression between left and right atria.
Project description:We report the mRNA sequencing of right and left atria from an adult inducible, cardiomyocyte-specific Notch gain-of-function mouse model (iNICD). Using the tetracycline-on system, we activated Notch by feeding doxycycline chow for 3 weeks to mice that were at least 8 weeks old. We asked what transcriptional changes occur in right versus left atrial cardiomyocytes in response to the same stimulus (Notch signaling). mRNA sequencing on separated right and left atria revealed that there are more differentially dysregulated transcripts (1,011) than similarly regulated transcripts (447) in the right and left atria, which is a simiar paradigm as what occurs in human atrial cardiomyocytes of patients with atrial fibrillation.
Project description:We report the application of a pericentriolar material 1 (PCM-1) based cardiomyocyte-specific nuclear isolation protocol on human cardiac tissue to specifically ask what transcriptional changes occur in cardiomyocytes of humans with atrial fibrillation. We performed RNA-sequencing on the cardiomyocyte-specific nuclear RNA and found that there are more differentially dysregulated (1343) than similarly regulated transcripts (99) in the right versus left atria. This study is the first of its kind aimed at understanding the transcriptional changes that occur specifically in the left and right atrial cardiomyocytes of humans with atrial fibrillation.
Project description:Atrial fibrillation (AF) is the most common persistent arrhythmia that affect 1–2% of the general population. People with AF display an array of complications cardiogenic stroke and systemic embolism caused by hemodynamic instability and blood hypercoagulability in clinical practice. However, it’s still unclear whether and how ubiquitylated proteins react to AF in the left atrial appendage of patients with AF and valvular heart disease. This theory focuses on the changes of ubiquitylated proteins in atrial fibrillation associated with heart valve disease. We firstly widely analysis the proteins ubiquitination in patients with atrial fibrillation.
Project description:Atrial fibrillation (AF) is the most common heart arrhythmia disease. The greatest risk of atrial fibrillation is stroke, and stroke caused by valvular heart disease with atrial fibrillation (AF-VHD) is more serious. the development mechanism from VHD to AF-VHD is not yet clear. The research on expression profiles of lncRNA and mRNA is helpful to explore molecular mechanism in patients with valvular heart disease who develop atrial fibrillation.
Project description:The right and left atria have different susceptibilities towards developing arrhythmias, with left atrial arrhythmias more commonly observed. To study potential underlying causes of this difference between the two upper chambers of the heart, four human left-right atrial pairs were subjected to whole-genome expression analyses via next generation sequencing of small RNAs, including microRNAs (miRNAs), and polyA enriched mRNAs. Using a paired sample design, significant differences in gene expression were found between the left and right atria in both the poly-A and small RNA fractions. Hsa-miR-143 was the most highly expressed miRNA in the atria as quantified by RNA-seq. Gene expression differences established during development are retained into adulthood including that of PITX2 and BMP10. In addition ten novel non-coding RNAs were found to be differentially expressed between the left and right atrias .
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).