Project description:Aneurysms are characterized by structural deterioration of the vascular wall leading to progressive dilatation and, potentially, rupture of the aorta. While aortic aneurysms often remain clinically silent, the morbidity and mortality associated with aneurysm expansion and rupture are considerable. Over 13,000 deaths annually in the United States are attributable to aortic aneurysm rupture with less than 1 in 3 persons with aortic aneurysm rupture surviving to surgical intervention. Environmental and epidemiologic risk factors including smoking, male gender, hypertension, older age, dyslipidemia, atherosclerosis, and family history are highly associated with abdominal aortic aneurysms, while heritable genetic mutations are commonly associated with aneurysms of the thoracic aorta. Similar to other forms of cardiovascular disease, family history, genetic variation, and heritable mutations modify the risk of aortic aneurysm formation and provide mechanistic insight into the pathogenesis of human aortic aneurysms. This review will examine the relationship between heritable genetic and epigenetic influences on thoracic and abdominal aortic aneurysm formation and rupture.
Project description:Central processes in the pathogenesis of TAV- (tricuspid aortic valve) and BAV- (bicuspid aortic valve) associated ascending thoracic aortic aneurysm (ATAA) development are still unknown. To gain new insights, we have collected aortic tissue and isolated smooth muscle cells of aneurysmal tissue and subjected them to in situ and in vitro analyses. We analyzed aortic tissue from 78 patients (31 controls, 28 TAV-ATAAs, and 19 BAV-ATAAs) and established 30 primary smooth muscle cell cultures. Analyses included histochemistry, immuno-, auto-fluorescence-based image analyses, and cellular analyses including smooth muscle cell contraction studies. With regard to TAV associated aneurysms, we observed a strong impairment of the vascular wall, which appears on different levels-structure and dimension of the layers (reduced media thickness, increased intima thickness, atherosclerotic changes, degeneration of aortic media, decrease of collagen, and increase of elastic fiber free area) as well as on the cellular level (accumulation of fibroblasts/myofibroblasts, and increase in the number of smooth muscle cells with a reduced alpha smooth muscle actin (α-SM actin) content per cell). The pathological changes in the aortic wall of BAV patients were much less pronounced-apart from an increased expression of osteopontin (OPN) in the vascular wall which stem from smooth muscle cells, we observed a trend towards increased calcification of the aortic wall (increase significantly associated with age). These observations provide strong evidence for different pathological processes and different disease mechanisms to occur in BAV- and TAV-associated aneurysms.
Project description:The bicuspid aortic valve is the most common congenital cardiac anomaly in developed nations. The abnormal bicuspid morphology of the aortic valve results in valvular dysfunction and subsequent hemodynamic derangements. However, the clinical presentation of bicuspid aortic valve disease remains quite heterogeneous with patients presenting from infancy to late adulthood with variable degrees of valvular stenosis and insufficiency and associated abnormalities including aortic coarctation, hypoplastic left heart structures, and ascending aortic dilatation. Emerging evidence suggests that the heterogeneous presentation of bicuspid aortic valve phenotypes may be a more complex matter related to congenital, genetic, and/or connective tissue abnormalities. Optimal management of patients with BAV disease and associated ascending aortic aneurysms often requires a thoughtful approach, carefully assessing various risk factors of the aortic valve and the aorta and discerning individual indications for ongoing surveillance, medical management, and operative intervention. We review current concepts of anatomic classification, pathophysiology, natural history, and clinical management of bicuspid aortic valve disease with associated ascending aortic aneurysms.
Project description:Giant abdominal aortic aneurysms (AAAs) are defined as AAAs >10 to 13 cm in the maximum transverse diameter. We have described a case of a patient who had presented for open repair of an 18-cm AAA and a review of reported cases of giant AAAs >10 cm in the maximum transverse diameter. Forty cases were compiled. The average maximum AAA diameter was 14.5 ± 4.1 cm. The AAA was ruptured on presentation in 12 patients (30%). Of the 40 cases, 34 (85%) were repaired with open surgery. The reported mortality was 15%. Despite the case complexity, five endovascular repairs were attempted.
Project description:BackgroundAs aortic aneurysms (AAs) enlarge, they can become life-threatening if left undiagnosed or neglected. At present, there is a lack of radical treatments for preventing disease progression. Therefore, we aimed to identify effective drug targets that slow the progression of AAs.MethodsA Mendelian randomization (MR) analysis was conducted to identify therapeutic targets which are associated with AAs. Summary statistics for AAs were obtained from two datasets: the UK Biobank (2228 cases and 408,565 controls) and the FinnGen study (3658 cases and 244,907 controls). Cis-expression quantitative trait loci (cis-eQTL) for druggable genes were retrieved from the eQTLGen Consortium and used as genetic instrumental variables. Colocalization analysis was performed to determine the probability that single nucleotide polymorphisms (SNPs) associated with AAs and eQTL shared causal genetic variants.FindingsFour drug targets (BTN3A1, FASN, PLAU, and PSMA4) showed significant MR results in two independent datasets. Proteasome 20S subunit alpha 4 (PSMA4) and plasminogen activator, urokinase (PLAU) in particular, were found to have strong evidence for colocalization with AAs, and abdominal aortic aneurysm in particular. Additionally, except for the association between PSMA4 and intracranial aneurysms, no association between genetically proxied inhibition of PLAU and PSMA4 was detected in increasing the risk of other cardiometabolic risks and diseases.InterpretationThis study supports that drug-targeting PLAU and PSMA4 inhibition may reduce the risk of AAs.FundingThis work was supported by National Key R&D Program of China (NO. 2017YFC0909400), Nature Science Foundation of China (No. 91839302, 81790624), Project supported by Shanghai Municipal Science and Technology Major Project (Grant No. 2017SHZDZX01), and Tongji Hospital Clinical Research Flagship Program (no. 2019CR207).
Project description:BackgroundAortic disease (aortic aneurysm (AA), dissection (AD)) is a serious threat to patient lives. Little is currently known about the molecular mechanisms and immune infiltration patterns underlying the development and progression of thoracic and abdominal aortic aneurysms (TAA and AAA), warranting further research.MethodsWe downloaded AA (includes TAA and AAA) datasets from the GEO database. The potential biomarkers in TAA and AAA were identified using differential expression analysis and two machine-learning algorithms. The discrimination power of the potential biomarkers and their diagnostic accuracy was assessed in validation datasets using ROC curve analysis. Then, GSEA, KEGG, GO and DO analyses were conducted. Furthermore, two immuno-infiltration analysis algorithms were utilized to analyze the common immune infiltration patterns in TAA and AAA. Finally, a retrospective clinical study was performed on 78 patients with AD, and the serum from 6 patients was used for whole exome sequencing (WES).ResultsThe intersection of TAA and AAA datasets yielded 82 differentially expressed genes (DEGs). Subsequently, the biomarkers (CX3CR1 and HBB) were acquired by screening using two machine-learning algorithms and ROC curve analysis. The functional analysis of DEGs showed significant enrichment in inflammation and regulation of angiogenic pathways. Immune cell infiltration analysis revealed that adaptive and innate immune responses were closely linked to AA progression. However, neither CX3CR1 nor HBB was associated with B cell-mediated humoral immunity. CX3CR1 expression was correlated with macrophages and HBB with eosinophils. Finally, our retrospective clinical study revealed a hyperinflammatory environment in aortic disease. The WES study identified disease biomarkers and gene variants, some of which may be druggable.ConclusionThe genes CX3CR1 and HBB can be used as common biomarkers in TAA and AAA. Large numbers of innate and adaptive immune cells are infiltrated in AA and are closely linked to the development and progression of AA. Moreover, CX3CR1 and HBB are highly correlated with the infiltration of immune cells and may be potential targets of immunotherapeutic drugs. Gene mutation research is a promising direction for the treatment of aortic disease.
Project description:ObjectiveThe need for biological markers of aortic wall stress and risk of rupture or dissection of ascending aortic aneurysms is obvious. To date, wall stress cannot be related to a certain biological marker. We analyzed aortic tissue and serum for the presence of different MMP-2 isoforms to find a connection between serum and tissue MMP-2 and to evaluate the potential of different MMP-2 isoforms as markers of high wall stress.MethodsSerum and aortic tissue from n = 24 patients and serum from n = 19 healthy controls was analyzed by ELISA and gelatin zymography. 24 patients had ascending aortic aneurysms, 10 of them also had aortic root aneurysms. Three patients had normally functioning valves, 12 had regurgitation alone, eight had regurgitation and stenosis and one had only stenosis. Patients had bicuspid and tricuspid aortic valves (9/15). Serum samples were taken preoperatively, and the aortic wall specimen collected during surgical aortic repair.ResultsPro-MMP-2 was identified in all serum and tissue samples. Pro-MMP-2 was detected in all tissue and serum samples from patients with ascending aortic/aortic root aneurysms, irrespective of valve morphology or other clinical parameters and in serum from healthy controls. We also identified active MMP-2 in all tissue samples from patients with ascending aortic/aortic root aneurysms. None of the analyzed serum samples revealed signals relatable to active MMP-2. No correlation between aortic tissue total MMP-2 or tissue pro-MMP-2 or tissue active MMP-2 and serum MMP-2 was found and tissue MMP-2/pro-MMP-2/active MMP-2 did not correlate with aortic diameter. This evidence shows that pro-MMP-2 is the predominant MMP-2 species in serum of patients and healthy individuals and in aneurysmatic aortic tissue, irrespective of aortic valve configuration. Active MMP-2 species are either not released into systemic circulation or not detectable in serum. There is no reliable connection between aortic tissue-and serum MMP-2 isoforms, nor any indication that pro-MMP-2 functions as a common marker of high aortic wall stress.
Project description:Current clinical practice for the assessment of abdominal aortic aneurysms (AAA) is based on vessel diameter and does not account for the multifactorial, heterogeneous remodeling that results in the regional weakening of the aortic wall leading to aortic growth and rupture. This study was conducted to determine correlation between a novel non-invasive surrogate measure of regional aortic weakening and the results from invasive analyses performed on corresponding ex vivo aortic samples. Tissue samples were evaluated to classify local wall weakening and likelihood of further degeneration based on non-invasive indices. A combined, image-based fluid dynamic and in-vivo strain analysis approach was used to estimate the Regional Aortic Weakness (RAW) index and assess individual aortas of AAA patients prior to elective surgery. Nine patients were treated with complete aortic resection allowing the systematic collection of tissue samples that were used to determine regional aortic mechanics, microstructure and gene expression by means of mechanical testing, microscopy and transcriptomic analyses. The RAW index was significantly higher for samples exhibiting lower mechanical strength (p = 0.035) and samples classified with low elastin content (p = 0.020). Samples with higher RAW index had the greatest number of genes differentially expressed compared to any constitutive metric. High RAW samples showed a decrease in gene expression for elastin and a down-regulation of pathways responsible for cell movement, reorganization of cytoskeleton, and angiogenesis. Please note that the sample 'characteristisc: strain' represents the in-vivo strain corresponding to each section of aorta, which is measured from dynamic CT images of patient AAA using a proprietary software.
Project description:Thoracic Aortic Aneurysm (TAA) is characterized by the dilation and degradation of the aorta and is fatal if not diagnosed and treated appropriately. There are no specific clinical symptoms, so better knowledge of the physiopathology of TAAs and their underlying genetic mechanisms is needed to improve diagnosis and therapy. MiRNAs regulate gene expression post-transcriptionally and are known to be involved in cerebrovascular disease. The current study aimed to identify differentially expressed miRNAs in patients with TAAs and determine whether their predicted target genes could be associated with this condition. Nanostring assays identified miRNAs in plasma and tissue samples from four TAA patients. RT-PCR validated the expression levels of these miRNAs in a further 22 plasma samples. Three, hsa-miR140-5p, hsa-miR-191-5p and hsa-miR-214-3p showed significant expression level differences between plasma samples collected pre- and post-surgically from each patient. Analyses of the predicted target gene controlled by these miRNAs revealed nine genes whose expression was investigated in the same 22 plasma samples. The gene expression levels were inversely correlated with the expression of their respective miRNAs. From these, CCND2, CRKL, HEY1, MTMR4, NFIA and PPP1CB, showed fold-change differences >1.5 between the two plasma samples. An in-depth literature search and Cytoscape software three genes; MTMR4, NFIA and PPP1CB, showed a possible association with the TGF-β signalling pathway. It is suggested that the three miRNAs detected together with their target genes could play a role in the TGF-β signalling pathway and thus be involved in TAA pathogenesis.