Shear Stress and NOTCH1 Regulate Calcification Related Genes in Human Aortic Valve Endothelium (ChIP-Seq)
ABSTRACT: We are interested in the role of NOTCH1 and Shear Stress in Aortic Valve Endothelium. Overall design: Primary aortic valve endothelial cells were infected with NOTCH1 intracellular domain fused with a myc tag in order to perform ChIP-seq.
Project description:We are interested in the role of NOTCH1 and Shear Stress in Aortic Valve Endothelium. Primary human aortic valve endothelium was subjected to 4 conditions in vitro. 1) Control siRNA, No shear stress. 2) NOTCH1 siRNA, No shear stress. 3) Control siRNA, 15 dynes/cm2 shear stress. 4) NOTCH1 siRNA, 15 dynes/cm2 shear stress. Triplicates of each condition were pooled for library perp and sequencing
Project description:Porcine aortic and aortic valve endothelial cells were exposed to 20 dynes/cm2 steady laminar shear stress with static cultures serving as controls. Total RNA was hybridized to Agilent Human 1 cDNA arrays and processed using the Agilent Feature Extraction Software Keywords = aortic valve Keywords = endothelial Keywords = shear stress Keywords: other
Project description:Aortic valve calcification is the most common form of valvular heart disease, but the mechanisms of calcific aortic valve disease (CAVD) are unknown. NOTCH1 mutations are associated with aortic valve malformations and adult-onset calcification in families with inherited disease. The Notch signaling pathway is critical for multiple cell differentiation processes, but its role in the development of CAVD is not well understood. The aim of this study was to investigate the molecular changes that occur with inhibition of Notch signaling in the aortic valve. Notch signaling pathway members are expressed in adult aortic valve cusps, and examination of diseased human aortic valves revealed decreased expression of NOTCH1 in areas of calcium deposition. To identify downstream mediators of Notch1, we examined gene expression changes that occur with chemical inhibition of Notch signaling in rat aortic valve interstitial cells (AVICs). We found significant downregulation of Sox9 along with several cartilage-specific genes that were direct targets of the transcription factor, Sox9. Loss of expression Sox9 has been published to be associated with aortic valve calcification. Utilizing an in vitro porcine aortic valve calcification model system, inhibition of Notch activity resulted in accelerated calcification while stimulation of Notch signaling attenuated the calcific process. Finally, the addition of Sox9 was able to prevent the calcification of porcine AVICs that occurs with Notch inhibition. In conclusion, loss of Notch signaling contributes to aortic valve calcification via a Sox9-dependent mechanism. 3 samples of aortic valve interstitial cells treated with DAPT were compared with 3 samples of aortic valve interstitial cells treated with DMSO
Project description:Ascending aortic aneurysms (AscAA) are a life-threatening disease whose molecular basis is poorly understood. Mutations in NOTCH1 have been linked to bicuspid aortic valve (BAV), which is associated with AscAA. Here, we describe a novel role for Notch1 in AscAA. We found that Notch1 haploinsufficiency exacerbated the aneurysmal aortic root dilation seen in the Marfan syndrome mouse model and that heterozygous deletion of Notch1 in the second heart field (SHF) lineage recapitulated this exacerbated phenotype. Lineage tracing analysis showed that loss of Notch1 in the SHF reduces the number of SHF-derived smooth muscle cells in the aortic root, and RNA-seq analysis demonstrated distinct in vivo expression patterns between lineage-specific regions of the ascending aorta. Finally, Notch1+/- mice in a predominantly 129S6 background develop aortic root dilation, indicating that loss of Notch1 independently predisposes to AscAA. These findings are the first to demonstrate a SHF lineage-specific role for Notch1 in AscAA and suggest that genes linked to the development of BAV may also contribute to the associated aortopathy. Overall design: To determine why dilation was localized to the aortic root in Notch1.129S6+/- mice, RNA-sequencing was performed on proximal and distal ascending aortic tissue from Notch1.129S6+/- mice and wildtype littermates at 2 months of age. Transcriptome analysis was utilized to better understand why the dilation was localized to the aortic root. Hierarchical cluster analysis grouped these samples based on location first and then genotype, and showed that cells of the proximal and distal ascending aorta have distinct gene expression patterns in vivo.
Project description:Calcification of the aortic valve leads to increased leaflet stiffness resulting in development of calcific aortic valve disease (CAVD); however, the underlying molecular and cellular mechanisms of calcification are poorly understood. Here, we investigated gene expressions in relation to valvular calcification and promotion of CAVD progression. Overall design: 3 samples of aortic valve from patients with calcific aortic valve disease (CAVD) were compared with 3 samples of aortic valve from age-matched normal subjects
Project description:Bicuspid aortic valve is well known as a risk factor of dilation of ascending aorta. But the mechanisms of dialation are unknown. Morever, patients with bicuspid aortic valve tend to be aortic valve disease at younger age. After aortic valve surgery, if ascending aorta is dilated, the patient must be performed re-operation. For that reason, surgery for aortic root or ascending aorta is recommended to patient with bicuspid aortic valve with dilated ascending aorta. We thought that abnormality of cell cycle of the structure protein participated in ascending aorta dilation of patient with bicuspid aortic valve. We resected the wall of the ascending aota from patient undergoing aortic valve replacement for aortic valve stenosis during operation, and performed immunohistochemical staining for akt. Anti Akt antibodys were stained much on aortic media with bicuspoed aortic valve. Akt is a protein that is involved in mTOR / PI3K, and modulate the cell differenciation and proliferation. Further, the same samples were analyzed using a microarray method. On bicuspid aortic valve patients, the expression of TSC2 is reduced, and GβL is increased. TSC2 inhibit this pathway, and MLST8 activate this pathway. In the ascending aorta of BAV patients, PI3K / mTOR system is considered to be activated. When this pathway is activated, cell proliferation and cytodifferentiation are promoted abnormally, Overall design: The aortic valve replacement surgery, excised the ascending aorta wall of aortotomy site, was used as a sample. We divided into 2 groups(bicuspid aortic valve vs tricuspid aortic valve) and analysed.
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. Overall design: Human aortic valves from during different stages of develoment of calcified aortic valve disease (normal, sclerotic, calcified) was selected for RNA extraction and hybridization on Affymetrix microarrays. All the patients were male.
Project description:Valve interstial cells(VICs) are the major cellular compents in the aortic valve. Under pathological circumstances, normal VICs differentiate into myofibroblasts or osteoblast-like phentotypes, which play important roles in the pathogenesis of calcified aortic valve disease. We used micrroarrary analysis to compare the global programme of gene expression in normal and calcified human aortic valve intersitial cells (VICs), in order to find out some key factors that mediate the phenotype change of VICs. Overall design: Calcified aortic valve leaflets (n=5) were obtained intraoperatively from patients undergoing aortic valve replacement due to severe aortic stenosis at University of Colorado Hospital. Patients with a history of infective endocarditis, rheumatic heart disease, or a genetic syndrome were excluded. The normal aortic valve leaflets (n=5) were collected from the explanted hearts of patients with cardiomyopathy and undergoing heart trans¬plantation. Valve leaflets were digested by collagenase 1 to procure P0 VICs. Then P0 VICs were sub-cultured to get P1 VICs.A fraction of P1 VICs subject to RNA extraction and microarray analysis.
Project description:Aortic valve calcification is a significant and serious clinical problem for which there are no effective medical treatments. Individuals born with bicuspid aortic valves, 1-2% of the population, are at the highest risk of developing aortic valve calcification. Aortic valve calcification involves increased levels of calcification and inflammatory genes. Bicuspid aortic valve leaflets experience increased strain. The molecular mechanisms involved in the pathogenesis of calcification of BAVs are not well understood, especially the molecular response to mechanical stretch. HOTAIR is a long non-coding RNA (lncRNA) that has been implicated with cancer but has not been studied in cardiac disease. We have found that HOTAIR levels are decreased in BAVs and in human aortic interstitial cells (AVICs) exposed to cyclic stretch. Reducing HOTAIR levels via siRNA in AVICs results in increased expression of calcification genes.