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: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:The goal of this study was to determine developmental differences in gene expression between left and right ventricle, and to assess the differential effect of altered hemodynamic loading on left and right ventricle. Chick ventricles from different developmental stages were isolated for assessment of normal developmental profiles. Conotruncal banding or partial ligation of the left atrial appendage was performed in ovo at embryonic day 4 and ventricles were isolated at embryonic day 5 (banding) or 8 (ligation) for assessment of altered loading effects.
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: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: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:Two wild-type mouse strains (Swiss Agouti and MF1) were investigated regarding the mRNA expression patterns of their left and right atria at 12 months of age.