Project description:To discover novel biomarkers for aortic aneurysm, serum samples of patients with thoracic aortic aneurysm were fractionated, tryptic digested, and subjected to proteome analysis.
Project description:To determine how gene expression is altered in aorta tissue in response to aortic aneurysm disease. Thoracic or abdominal aorta tissue was isolated from patients requiring surgery due to aortic aneurysm or other (control) reason.
Project description:Thoracic and abdominal aortic aneurysm poses a substantial mortality risk in adults, yet many of its underlying factors remain unidentified. Here, we identify mitochondrial nicotinamide adenine dinucleotide (NAD)⁺ deficiency as a causal factor for the development of aortic aneurysm. Multiomics analysis of 150 surgical aortic specimens indicated impaired NAD+ salvage and mitochondrial transport in human thoracic aortic aneurysm, with expression of the NAD+ transporter SLC25A51 inversely correlating with disease severity and postoperative progression. Genome-wide gene-based association analysis further linked low SLC25A51 expression to risk of aortic aneurysm and dissection. In mouse models, smooth muscle-specific knockout of Nampt, Nmnat1, Nmnat3, Slc25a51, Nadk2 and Aldh18a1, genes involved in NAD+ salvage and transport, induced aortic aneurysm, with Slc25a51 deletion producing the most severe effects. Using these models, we suggest a mechanism that may explain the disease pathogenesis: the production of type III procollagen during aortic medial matrix turnover imposes a high demand for proline, an essential amino acid component of collagen. Deficiency in the mitochondrial NAD⁺ pool, regulated by NAD⁺ salvage and transport, hinders proline biosynthesis in mitochondria, contributing to thoracic and abdominal aortic aneurysm.
Project description:In current models of ascending aortic disease, mural cells undergo phenotypic changes that promote extracellular matrix destruction and structural weakening. To explore the intersection of this biology with quantitative trait GWAS loci we analyzed the genetic features of thoracic aortic aneurysm tissue. Single nuclear RNA sequencing was performed on 13 samples from human donors, 6 with thoracic aortic aneurysm and 7 without aneurysm. Individual transcriptomes were then clustered based on transcriptional profiles. Clusters were used for between-disease differential gene expression analyses, subcluster analysis, and analyzed for intersection with genetic aortic trait data. In total, we sequenced 71,689 nuclei from human thoracic aortas without aneurysm, and with sporadic aneurysm. We identified 14 clusters, aligning with 11 cell types, predominantly VSMCs, consistent with existing histologic data, but contrary to the majority of human aortic single cell studies to-date. With unbiased methodology, we found 7 VSMC and 6 fibroblast subclusters. Differentially expressed genes (DEGs) analysis revealed a VSMC group accounting for the majority of differential gene expression. Fibroblast populations in aneurysm exhibit distinct behavior with almost complete disappearance of quiescent fibroblasts. DEGs were used to prioritize genes at aortic diameter and distensibility GWAS loci highlighting the genes JUN, LTBP4, and IL34 in fibroblasts, ENTPD1, PDLIM5, ACTN4, and GLRX in VSMCs, as well as LRP1 in macrophage populations. In conclusion, using nuclear RNA sequencing we describe the cellular diversity of healthy and aneurysmal human ascending aorta. Sporadic aortic aneurysm is characterized by differential gene expression within known cellular classes rather than by the appearance of novel cellular forms. Single nuclear RNA sequencing of aortic tissue can be used to prioritize genes at aortic trait loci.
Project description:Aneurysmatic and dissection cells show a specific alteration of gene expression, which allow a disease specific distinction. We used microarrays to analyse the cellular gene expression of controls, thoracic aortic aneurysm, and aortic dissection.
Project description:Comparison of whole genome expression profiles to characterize gene expression during development of thoracic aortic aneurysm in fibrillin-1 hypomorphic mice (Fbn1mgR/mgR).
Project description:Patients with bicuspid aortic valve (BAV) have increased risk of thoracic ascending aortic aneurysm (AscAA) and dissection compared to those with a normal tricuspid aortic valve (TAV). The present study was undertaken to evaluate whether differences in gene expression exist in aortas from BAV and TAV patients with AscAA. Keywords: disease state analysis
Project description:Bicuspid aortic valve (BAV) is the most common congenital heart anomaly and is prone to cause complications, such as valvular stenosis and thoracic aortic dilation. There is currently no reliable way to predict the progression rate to thoracic aortic aneurysm. Here, we aimed to characterize the proteomic landscape in the plasma of stenotic BAV patients and provide potential biomarkers to predict progressive aortic dilation. Plasma samples were obtained from 45 subjects (30 stenotic BAV patients and 15 healthy controls). All samples were properly prepared and analyzed using mass spectrometry (MS)-based label-free quantitative proteomics.
Project description:Enlargement or aneurysm of the aorta predisposes to dissection, an important cause of sudden death. We trained a deep learning model to evaluate the dimensions of the ascending and descending thoracic aorta in 4.6 million cardiac magnetic resonance images from the UK Biobank. We then conducted genome-wide association studies in 39,688 individuals, revealing 82 loci associated with ascending and 47 with descending thoracic aortic diameter, of which 14 loci overlapped. Transcriptome-wide analyses, rare-variant burden tests, and human aortic single nucleus RNA sequencing prioritized genes including SVIL, which was strongly associated with descending aortic diameter. A polygenic score for ascending aortic diameter was associated with thoracic aortic aneurysm in 385,621 UK Biobank participants (HR = 1.43 per SD; CI 1.32-1.54; P = 3.3·10-20). Our results illustrate the potential for rapidly defining quantitative traits with deep learning, an approach that can be broadly applied to biomedical images.
Project description:Aortic aneurysms is increasing as the human population ages. Pathological oxidative stress is implicated in development of aortic aneurysms. We pursued a chemogenetic approach to create an animal model of aortic aneurysm formation using a transgenic mouse line DAAO-TGTie2 that expresses yeast D-amino acid oxidase (DAAO) under control of the endothelial Tie2 promoter. In DAAO-TGTie2 mice, DAAO generates the reactive oxygen species hydrogen peroxide (H2O2) in endothelial cells only when provided with D-amino acids. When DAAO-TGTie2 mice are chronically fed D-alanine, the animals become hypertensive and develop abdominal but not thoracic aortic aneurysms. Generation of H2O2 in the endothelium leads to oxidative stress throughout the vascular wall. Proteomic analyses indicate that the oxidant-modulated protein kinase JNK1 is dephosphorylated by the phophoprotein phosphatase DUSP3 in abdominal but not thoracic aorta, causing activation of KLF4-dependent transcriptional pathways that trigger phenotypic switching and aneurysm formation. Pharmacological DUSP3 inhibition completely blocks aneurysm formation caused by chemogenetic oxidative stress. These studies establish that regional differences in oxidant-modulated signaling pathways lead to differential disease progression in discrete vascular beds, and identify DUSP3 as a potential pharmacological target for the treatment of aortic aneurysms.