Project description:Atrial cardiomyocytes undergo complex cellular behaviours after 72 hours post fertilization to build muscle structures. We aimed to identify the genes involved during this process, and therefore we seqeunced the RNA from 48 and 72 hpf atrial cardiomyocytes to uncover changes in the transcirptome that might regulate or trigger atrial morphogenesis after 72 hpf.
Project description:Electrical and structural remodeling processes are contributors to the self-perpetuating nature of atrial fibrillation (AF). However, their correlation has not been clarified. In this study, human atrial tissues from the patients with rheumatic mitral valve disease in either sinus rhythm or persistent AF were analyzed using a combined transcriptomic and proteomic approach. An up-regulation in chloride intracellular channel (CLIC) 1, 4, 5 and a rise in type IV collagen were revealed. Combined with the results from immunohistochemistry and electron microscope analysis, the distribution of type IV collagen and effects of fibrosis on myocyte membrane indicated the possible interaction between CLIC and type IV collagen, confirmed by protein structure prediction and co-immunoprecipitation. These results indicate that CLICs play an important role in the development of atrial fibrillation and that CLICs and structural type IV collagen may interact on each other to promote the development of AF in rheumatic mitral valve disease.
Project description:Atrial fibrillation (AF) is currently the most prevalent arrhythmia worldwide.Recent clinical data implicate the additional contribution of non-coding RNAs in the pathogenesis of AFï¼which include microRNAs(miRNAs), endogenous small interfering RNAs, PIWIinteracting RNAs, and lncRNA. Notably, a growing number of lncRNAs have been implicated in disease etiology, although an association with AF has not been reported. In the present study, we conducted an integrated analysis of dysregulated lncRNA and mRNA expression profiles in myocardial sleevesof pulmonary veins between the patients who develop AF and the patients who were in normal sinus rhythm, which was performed using a second generation lncRNA microarrayï¼focusing specifically on the identification and characterization of lncRNAs and mRNA potentially involving in maintaining atrial fibrillation. We conducted an integrated analysis of myocardial sleeves of pulmonary veinsï¼PVsï¼from 12 patients (6 non-AF and 6AF) in our center, of which hypertension, diabetes, smoking and alcohol abuse were excluded, using a second generation lncRNA microarray
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:Atrial fibrillation (AF) is currently the most prevalent arrhythmia worldwide.Recent clinical data implicate the additional contribution of non-coding RNAs in the pathogenesis of AF,which include microRNAs(miRNAs), endogenous small interfering RNAs, PIWIinteracting RNAs, and lncRNA. Notably, a growing number of lncRNAs have been implicated in disease etiology, although an association with AF has not been reported. In the present study, we conducted an integrated analysis of dysregulated lncRNA and mRNA expression profiles in myocardial sleevesof pulmonary veins between the patients who develop AF and the patients who were in normal sinus rhythm, which was performed using a second generation lncRNA microarray,focusing specifically on the identification and characterization of lncRNAs and mRNA potentially involving in maintaining atrial fibrillation.
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:Catheter ablation is an effective treatment to prevent recurrence of Atrial fibrillation (AF) and can be used to maintain sinus rhythm and improve symptoms of AF, but to some extent it can cause a range of adverse effects associated with catheter ablation. Pulsed electric field is a newer treatment modality to replace catheter ablation for atrial fibrillation due to its fewer side effects. Different from radiofrequency ablation, which destroys diseased myocardial tissue by thermal energy, pulsed electric field ablation achieves the purpose of atrial fibrillation ablation by inducing damage to diseased myocardial cells through irreversible electroporation. However, some experimental parameters and mechanism of pulsed electric fields remain unclear.
Project description:This study will report the incidence of atrial fibrillation after elective colorectal cancer resection in the over 65 age group. This will be used to validate a risk model for the development of post-operative atrial fibrillation.
Eligible patients will undergo electrocardiogram based screening for atrial fibrillation, as well as brain natriuretic peptide tests prior to surgery. They will undergo 24 hour holter monitor prior to surgery, and at 30 and 90 days following surgery.
The primary outcome will be occurrence of atrial fibrillation within 90 days of surgery. Secondary outcomes include quality of life change, use of hospital services for atrial fibrillation, and complications of atrial fibrillation. This will be used to validate the pre-existing model for prediction of atrial fibrillation.
Project description:Background Atrial fibrosis plays a critical role in the development of atrial fibrillation (AF). Exosome is a promising cell-free therapeutic approach for the treatment of AF. The purpose of this study was to explore the mechanisms underlying exosomes derived from atrial myocytes regulated atrial remodeling and ask whether their manipulation allows for therapeutic modulation of fibrosis potential abnormalities during AF. Methods We isolated exosomes from atrial myocytes and patients serum, microRNA (miRNA) sequencing analyzed the exosomal miRNAs in atrial myocytes-exosomes and patients serum-exosomes. mRNA sequencing and bioinformatics analysis corroborate the key gene as direct targets of miR-210-3p. Results The miRNAs sequencing analysis identified that miR-210-3p expression significantly increased in exosomes of tachypacing atrial myocytes and serum of AF patients. In vitro, the analysis showed that miR-210-3p inhibitor reversed tachypacing-induced proliferation and collagen synthesis in atrial fibroblasts. Accordingly, KO miR-210-3p could reduce the incidence of AF and ameliorate atrial fibrosis induced by Ang Ⅱ. The mRNA sequencing analysis and Dual-Luciferase reporter assay proved that glycerol-3-phosphate dehydrogenase 1-like (GPD1L) is the potential target gene of miR-210-3p. The functional analysis suggests that GPD1L regulated atrial fibrosis via PI3K/AKT signaling pathway. Besides, silencing GPD1L in atrial fibroblasts induced cells proliferation and these effects could be reversed by PI3K inhibitor (LY294002). Conclusion We demonstrate that atrial myocytes-derived exosomal miR-210-3p promoted the proliferation and collagen synthesis via inhibiting GPD1L in atrial fibroblasts. Preventing pathological crosstalk between atrial myocytes and fibroblasts may be as a novel target to improve atrial fibrosis in AF.