Deep learning enables genetic analysis of the human thoracic aorta
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ABSTRACT: 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:We report dynamic temporal and spatial smooth muscle cell phenotype modulation using aortic single cell RNA sequencing in a murine model of Marfan syndrome (Fbn1C1041G/+) and littermate controls. Aortic root/ascending aortic tissue samples from both genotypes were studied at 4 and 24 weeks of age. The non-aneurysmal descending thoracic aorta was also studied at 24 weeks. Finally human aortic tissue from a Marfan syndrome patient undergoing aneurysm repair surgery was studied.
Project description:The purpose of this study was to determine whether lysyl oxidase inhibition using β-aminopropionitrile (BAPN) induced region-specific aortopathies in mice. The effects of BAPN were first characterized with regard to dose, strain, age, and sex. Subsequently, BAPN was administered to young male C57BL/6J mice. BAPN-induced aortic rupture predominantly occured or originated in the descending thoracic aorta. For mice surviving 12 weeks of BAPN administration, profound dilatation was consistently observed in the ascending region, while relatively sporadic in the descending thoracic region. Pathological features were distinct between the ascending and descending thoracic regions. Aortic pathology in the ascending region was characterized by luminal dilatation and elastic fiber disruption throughout the media. The descending thoracic region frequently had dissection with false lumen formation, macrophage infiltration, collagen deposition, and remodeling of the media and adventitia. Cells surrounding the false lumen were predominantly positive for α-smooth muscle actin. To investigate the molecular basis of the regional heterogeneity, ascending and descending thoracic aortas were harvested after one week of BAPN administration prior to the appearance of overt pathology. BAPN compromised contractile properties in both regions equivalently, while RNA sequencing demonstrated that BAPN altered transcriptomes related to extracellular matrix and cell division differentially between the two regions. In conclusion, BAPN-induced pathologies show distinct, heterogeneous features within and between ascending and descending aortic regions in young mice.
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: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. Experiment Overall Design: Aneurysmal tissue of ascending aorta was collected from 13 patients with bicuspid aortic valve (BAV) and 12 patients with tricuspid aortic valve (TAV). Patients were selected on the basis of aortic diameter, age and other disease conditions. Patients with giant cell aortitis, cardiovascular abnormalities, inherited connective tissue disorders such as Marfan and Ehlers-Danlos syndrome were excluded from the study. RNA was extracted using Invitrogen RNA extraction kit and shown to be of adequate quality before application to Affymetrix microarray U133A gene chips probing for over 16,000 genes per chip. Two different methods of data analysis were performed: a linear model and GeneSpring.
Project description:JAK2V617F mutation is associated with an increased risk for athero-thrombotic cardiovascular disease, but its role in aortic disease development and complications remains unknown. In a cohort of patients with myeloproliferative neoplasm, JAK2V617F mutation was identified as an independent risk factor for dilation of both the ascending and descending thoracic aorta. Using single-cell RNA-seq, complementary genetically-modified mouse models, as well as pharmacological approaches, we found that JAK2V617F mutation was associated with a pathogenic pro-inflammatory phenotype of perivascular tissue-resident macrophages, which promoted deleterious aortic wall remodeling at early stages, and dissecting aneurysm through the recruitment of circulating monocytes at later stages. Finally, genetic manipulation of tissue-resident macrophages, or treatment with a Jak2 inhibitor, ruxolitinib, mitigated aortic wall inflammation and reduced aortic dilation and rupture. Overall, JAK2V617F mutation drives vascular resident macrophages toward a pathogenic phenotype and promotes dissecting aortic aneurysm.
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:Descending thoracic aortic aneurysms and dissections can go undetected until severe and catastrophic, and few clinical indices exist to screen for aneurysms or predict their risk of dissection or rupture. This study generated a plasma proteomic dataset from 150 patients with descending thoracic aortic disease and 52 controls to identify proteomic signatures capable of differentiating descending thoracic aortic disease from non-disease controls, as well as between cases with aneurysm versus descending ‘type B’ dissection. Of the 1,468 peptides and 195 proteins quantified across all samples, 853 peptides and 99 proteins were quantitatively different between disease and control patients (BH adjusted p-value < 0.01 from t-tests). Supervised machine learning (ML) methods were used to classify disease from control and aneurysm from descending dissection cases. The highest precision-recall area under the curve (PR AUC) was achieved on the held-out test set using significantly different proteins between disease and control patients (PR AUC 0.99), followed by input of significant peptides (PR AUC 0.96). Despite no statistically significant proteins between aneurysm and dissection cases, use of all proteins was able to modestly classify between the two disease states (PR AUC 0.77). To overcome correlation in the proteins and enable biological pathway analysis, a disease versus control classifier was optimized using only seven unique protein clusters, which achieved comparable performance to models trained on all/significant proteins (accuracy 0.88, F1-score 0.78, PR AUC 0.90). Model interpretation with permutation importance revealed that proteins in the most important clusters for differentiating disease and control function in coagulation, protein-lipid complex remodeling, and acute inflammatory response.
Project description:Fibulin-4 plays an essential role in elastic fiber formation, though it's exact function is unclear. Mice lacking the fibulin-4 gene develop cutis laxa with thoracic aortic aneurysms and have narrowed descending aortic diamaters, dying shortly after birth. Another model that disrupt elastic fiber formation, elastin gene knockeds, are also perinatally lethal and have narrowed descending aortas but do not develop thoracic aneurysms. We hypothesized that there may be altered gene expression to explain the altered anatomy based on aortic tissue location we observed, which may provide therapeutic target(s) Ascending and descending aortas of p0 mouse pups were dissected, pooled in groups of eight, and homogenized to isolate RNA and we used microarrays on the pooled samples to identify genes that had expression significantly changed.
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:In the present study, we evaluated miRNA expression profiles of 32 patient aortic aneurysm tissue and plasma samples using Illumina next-generation sequencing platform. A total of 20 miRNA were differentially expressed in tissues, 17 miRNAs - in plasma samples. Differentially expressed miRNAs determined in the present study could be applied for thoracic ascending aneurysm diagnosis.