Project description:Aortic valve regurgitation (AR) imposes a severe volume overload to the left ventricle (LV) which results in dilation, eccentric hypertrophy and eventually loss of function. Little is known about the impact of AR on LV gene expression. We therefore conducted a gene expression profiling study in the LV of male Wistar rats with chronic (9 months) and severe AR. Five male Wistar rats had one or two aortic valve leaflets punctured with a catheter under echocardiographic guidance in order to induce severe regurgitation (>65% of blood regurgitating during diastole from the aorta to the left ventricle). Five additional rats were sham-operated. The animals were sacrificed 9 months after the procedure and their left ventricle collected for RNA extraction and microarray analysis.
Project description:Aortic valve regurgitation (AR) imposes a severe volume overload to the left ventricle (LV) which results in dilation, eccentric hypertrophy and eventually loss of function. Little is known about the impact of AR on LV gene expression. We therefore conducted a gene expression profiling study in the LV of male Wistar rats with chronic (9 months) and severe AR.
Project description:To characterize a expression patterns in the heart, we used rat. 12 Wistar male rats (8 - 11 weeks) were sacrificed. Left atrium (LA) adjacent to the pulmonary vein (PV), a mass of left ventricle (LV), and free-wall of the right ventricle (RV) was isolated. Each LV mass was dissected into three pieces as samples. Because the SAN isolation procedure takes approximately 20 minutes, SA was isolated separately. The SA region was delimited by the borders of the crista terminalis, the interatrial septum, the superior vena cava, and right atrium (RA). In addition to PV, LV, RV, SA, and RA samples, pulmonary arteries were added to the samples for the rat microarray.
Project description:Located at the junction of left ventricle and ascending aorta, aortic root is a central cardiovascular structure consisting of aortic valve and coronary ostium that are essential for systemic and coronary circulation, respectively. Malformations of aortic valve and coronary ostium are common birth defects and may occur together in human patients, leading to complex complications including aortic valve stenosis, myocardial ischemia, heart failure and sudden cardiac death. Despite of their physiological and clinical significances, the developmental and molecular mechanisms by which coordinate the formation of aortic valve and coronary ostium remain poorly understood. Here we report that SOX17 (SRY-box 17) is an essential transcription factor required for the maturation of aortic root, as well as the patterning of aortic valve and coronary ostium. We show in mouse that deletion of Sox17 in the aortic root endothelium results in defective aortic valve with underdeveloped non-coronary leaflet (NCL) or bicuspid aortic valve (BAV) without NCL. The valve defects are accompanied by misplaced left coronary ostium that reduces coronary blood flow, leading to myocardial hypoxia and death of embryos. Mechanistically, deletion of Sox17 decreases the expression of Pdgfb (Platelet derived growth factor, B polypeptide) in the aortic root endothelium and the PDGF growth signaling in the NCL mesenchyme and aortic root smooth muscle, both of which are derived from the second heart field (SHF) cardiomyocyte precursors. Furthermore, the deletion upregulates the expression of Ctgf (Connective tissue growth factor) and the extracellular matrix (ECM) genes, whereas downregulates the vascular smooth muscle genes, in the forming aortic root. Together, these findings support a developmental disease mechanism in which delayed growth and maturation of aortic root, due to lack of SOX17-PDGF/CTGF signaling, contributes to BAV and CAAs, two common congenital cardiovascular defects.
Project description:Hypoplastic left heart syndrome (HLHS) is characterized by underdevelopment of left sided structures including the ventricle, valves, and aorta1. Although the mechanisms of disease pathogenesis remain elusive due to a paucity of candidate genes and animal models, prevailing paradigm suggests that HLHS is a multigenic disease of co-occurring phenotypes2,3. Here, we report that zebrafish lacking two orthologs of the RNA binding protein RBFOX2, a gene previously linked to HLHS in humans4,5, display cardiovascular defects overlapping those in HLHS patients. In contrast to current models, we demonstrate that co-existing ventricular, valve, and aortic deficiencies in rbfox mutant zebrafish arise secondary to impaired myocardial function as all three phenotypes are rescued when Rbfox is expressed specifically in the myocardium. On a molecular and cellular level, we find diminished expression and alternative splicing of sarcomere and mitochondrial components in rbfox-deficient hearts that compromise sarcomere assembly and mitochondrial respiration, respectively. Injection of human RBFOX2 mRNA restores ventricular structure and function in rbfox mutant zebrafish, while HLHS-linked RBFOX2 variants fail to rescue. Taken together, our data suggest that mutations in RBFOX2 are causal for HLHS pathogenesis and provide a complimentary paradigm for HLHS emergence where co-existing ventricular, valve, and aortic deficiencies have a monogenic etiology caused by myocardial dysfunction.
Project description:We compared 15 severely diseased aortic valve sample to 16 control aortic valve samples using microRNA microarrays (Affymetrix GeneChip miRNA 2.0). The diseased samples were taken from areas of severe disease of aortic valves removed at aortic valve replacement for severe aortic stenosis. Control samples were obtained from macroscopically normal post-mortem aortic valves. In addition, we compared areas of mild or moderate disease on valves from participants with severe aortic stenosis to the same participant's severely diseased sample in seven participants.
Project description:Affymetrix GeneChip Exon-1.0ST was used to study the differential gene profiles in RV (right ventricle) samples from neonates with HLHS (hypoplastic left heart syndrome) versus RV and LV (left ventricle) samples obtained from age-matched controls. Although few significant changes were observed in the genetic profiles between control LV and control RV, many genes passed the false discovery rate in comparing HLHS-RV to RV and LV control groups, with greater differential profiles noted between HLHS-RV and control RV. Myocardial samples were isolated from the RV of 6 HLHS neonates, diagnosed based upon clinical features including hypoplasia/atresia of the ascending aorta, various degrees of underdevelopment of the aortic valve, mitral valve, and LV cavity, and retrograde flow in the aortic arch as determined by conventional 2-D echocardiography. The mean gestational age at birth of all subjects was 38 weeks (range 36-39) and the mean body weight at surgery of 2.7 kg (range 2.1-3.4 kg) (3 males, 3 females). All subjects were undergoing stage 1 Norwood reconstruction. Children with HLHS and other complex cardiac anomalies entailing non-HLHS single ventricle circulation were excluded from our study. For control samples, RV and LV myocardial tissue was obtained from 5 newborns aged between 1-28 days (mean 18 days; 3 males and 2 females) with normal cardiac anatomy and expired from non-cardiac diseases processes.
Project description:Calcific Aortic Valve Disease (CAVD) is a common heart valve condition, often characterized by severe narrowing of the aortic valve. It lacks pharmaceutical treatments and typically requires aortic valve replacement surgery, imposing a significant burden on healthcare resources.This study reports the expression profile of circRNAs in the aortic valve tissues of CAVD patients and a normal control group (non-CAVD). We collected aortic valve tissue samples from three CAVD patients who underwent aortic valve replacement surgery due to severe aortic valve stenosis, as well as aortic valve samples from non-CAVD patients who either received heart transplant surgery (recipient heart) or had their aortic valve removed due to aortic dissection. Overall, our research reveals the significant role of circRNAs in the progression of CAVD. CircRNAs, a class of circular non-coding RNA molecules, are actively studied for their functions and regulatory mechanisms within cells. These findings contribute to a deeper understanding of the molecular mechanisms underlying CAVD, particularly the potential involvement of circRNAs in this disease.
Project description:Calcific aortic valve disease is the most common form of valvular heart disease in the Western World. Milder degrees of aortic valve calcification is called aortic sclerosis and severe calcification with impaired leaflet motion is called aortic stenosis. We used microarrays to detail the global programme of gene expression underlying cdevelopment of calcified aortic valve disease in humans.
Project description:Myocardial left ventricular biopsies from male patients (n=6) with isolated aortic stenosis and pronounced left ventricular hypertrophy undergoing aortic valve replacement were harvested either from hearts with normal ejection fraction (EF,>50%) or with low EF (<30%). Biopsies were further obtained from non-hypertrophied hearts with normal EF (>60%) from coronary artery disease patients undergoing coronary artery bypass graft surgery (n=3). Total RNA isolated from biopsies was analyzed using Affymetrix HG-U133A and U133B GeneChip sets.