Cardiovascular Lesions in Bovine Marfan Syndrome

1994 ◽  
Vol 31 (5) ◽  
pp. 501-509 ◽  
Author(s):  
K. A. Potter ◽  
T. E. Besser
Keyword(s):  
Pulmonary Artery ◽  
Cardiac Tamponade ◽  
Marfan Syndrome ◽  
Aortic Rupture ◽  
Elastic Fibers ◽  
Aortic Tissue ◽  
Aortic Dilatation ◽  
Cystic Medial Necrosis ◽  
Aortic Media ◽  
Elastic Laminae

Bovine Marfan syndrome is a genetic disease with many of the clinical and pathologic manifestations of human Marfan syndrome. Major manifestations include ectopia lentis and aortic dilatation, aneurysm, and rupture. Affected cattle have a defect in fibrillin metabolism similar to that in human patients. Ten cattle were followed and their disease progression and lesions documented. Ages ranged from a term fetus (No. 9) to a 4-year-old cow (No. 4); three animals were male (Nos. 1–3) and seven were female (Nos. 4–10). Of eight animals (80%) that died or were euthanatized (Nos. 1–3, 5–9), six (75%) had severe cardiovascular lesions identified at necropsy. Gross cardiovascular lesions of bovine Marfan syndrome included cardiac tamponade secondary to aortic rupture (animal Nos. 3, 6, 8), dissecting aneurysms of the aorta and pulmonary artery (animal No. 5), and intrauterine cardiac tamponade secondary to rupture of the pulmonary artery (animal No. 9). Microscopically, Verhoeff Van Gieson-stained sections of aorta contained severe fragmentation of the elastic laminae in the aortic media, but the cystic medial necrosis seen in human Marfan aortae was not identified, even in the chronic aortic dissection. Ultrastructurally, affected aortic tissue was characterized by thin, dark elastic fibers with abundant, tangled microfibrils on the periphery, Swirls of collagen fibers and bundles of hypertrophic smooth muscle cells replaced damaged elastic laminae. Gross and microscopic cardiovascular lesions in bovine Marfan syndrome are similar to those in human Marfan syndrome. Bovine Marfan syndrome is a valuable model for investigation of molecular pathogenesis and treatment of human Marfan syndrome.

Abstract 2677: Reduction In Tie-2+/flk-1+ Vascular Stem Cells In Thoracic Aortic Aneurysm With Dissections: A Novel Contributor To Acellular Lesion Development

Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
Yong-Jian Geng ◽  
Dongchun Guo ◽  
Dianna M Milewicz ◽  
L. Maximillian Buja ◽  
Jinjie Wang ◽  
...  
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Vascular Endothelial Cell ◽  
Aortic Aneurysms ◽  
Elastic Fibers ◽  
Aortic Tissue ◽  
Vascular Progenitor Cells ◽  
Aortic Media ◽  
Life Threatening ◽  
Vascular Stem Cells

Background. Ascending thoracic aortic aneurysms leading to type A dissections (TAAD) are a life-threatening disease triggered by a complex interactions between environmental and genetic factors. Pathologically, this disease is characterized by a progressive loss of vascular smooth muscle cells (SMCs) and extracellular elastic fibers in the aortic media. Apoptosis, a form of programmed cell death, has been shown to contribute to the loss of medial SMCs. However, little is known about the role of vascular progenitor or stem cells in the pathogenesis of aortic aneurysms. Methods and Results. In this study we examined expression of Tie-2 (receptor for angiopoietin) and Flk-1 (receptor for vascular endothelial cell growth factor), two receptors critical for regulation of vascular stem cell survival and growth in the aortic lesions of patients with TAAD. Immunohistochemistry with specific antibodies against Tie-2 and Flk-1 showed a marked reduction in the numbers of Tie+/Flk+ cells in TAAD when compared to control aortas. There was also a change in the distribution pattern of vascular progenitor cells positive for both Tie-2 and Flk-1 in TAAD patients’ aortic tissues. Compared to normal control aortas, the Tie-2 and Flk-1 immunostained cells were much lower in intensity and scattered. In the regions with paucity of Tie-2+/Flk-1+ cells, there was an increased number of apoptotic cells as determined by in situ DNA end-labeling (TUNEL). Many of the Tie-2 and Flk-1 positive cells in TAAD showed poor morphology with nuclear degeneration and cytoplasmic fragmentation and disarray. Conclusion . These results indicate a paucity of Tie-2+/Flk-1+ vascular stem cells in the aortic wall of patients with TAAD, implying that the stem cell capacity to regenerate SMCs is exhausted. Similar loss of stem cells is observed with Duchenne muscular dystrophy, where the regenerated capacity is significantly compromised. Stem cells loss may similarly impair the capacity of SMCs in aortic tissue in repair and regeneration, and ultimately lead to TAAD formation.

Abstract 480: Aortic Microcalcification Associates With Aortic Elastin Fragmentation in Marfan Syndrome

2017 ◽  
Vol 37 (suppl_1) ◽  
Author(s):  
Shaynah Wanga ◽  
Stijntje Hibender ◽  
Yanto Ridwan ◽  
Cindy van Roomen ◽  
Mariska Vos ◽  
...  
Keyword(s):  
Marfan Syndrome ◽  
Kinase Inhibitor ◽  
Aortic Rupture ◽  
Matrix Gla Protein ◽  
Aortic Diameter ◽  
Prophylactic Surgery ◽  
Aortic Tissue ◽  
Receptor Complex ◽  
Elastin Receptor ◽  
Elastin Degradation

Marfan syndrome (MFS) is a genetic connective tissue disorder, in which aortic rupture is the major cause of death. MFS patients with an aortic diameter below the advised limit for prophylactic surgery (<5cm) may unexpectedly experience an aortic dissection or rupture, despite yearly monitoring. Hence, there is a clear need for improved prognostic markers to predict such aortic events. We hypothesize that elastin fragments play a causal role in aortic calcification in MFS and that microcalcification serves as a novel marker for aortic disease severity. To address this hypothesis, we analyzed MFS patient and mouse aortas. MFS patient aortic tissue showed enhanced microcalcification in areas with extensive elastic lamina fragmentation in the media. A causal relationship between medial injury and microcalcification was revealed by studies in vascular smooth muscle cells (SMCs); elastin peptides were shown to increase the activity of the calcification marker alkaline phosphatase (ALP) and reduce the expression of the calcification inhibitor matrix gla protein (MGP) in human SMCs. In murine Fbn1 C1039G/+ MFS aortic SMCs, ALP mRNA and activity was upregulated when compared to wildtype SMCs. The elastin peptide-induced ALP activity was prevented by incubation with lactose as inhibitor of the elastin receptor complex, and a MEK1/2 kinase inhibitor, indicating downstream involvement of ERK1/2 phosphorylation. Histological analyses in MFS mice revealed macrocalcification in the aortic root, while the ascending aorta contained microcalcification, as identified with the near-infrared fluorescent bisphosphonate probe OsteoSense-800. Significantly, microcalcification correlated strongly with aortic diameter, aortic distensibility, elastin breaks and phosphorylated ERK1/2. In conclusion, microcalcification co-localizes with aortic elastin degradation in MFS aorta of man and mice, where elastin-derived peptides induce a calcification process in SMCs via the elastin receptor complex and ERK1/2 activation. We propose microcalcification as a novel imaging marker to monitor local elastin degradation and thus predict aortic events in MFS patients.

Glutathione system participation in thoracic aneurysms from patients with Marfan syndrome

VASA ◽  
2017 ◽  
Vol 46 (3) ◽  
pp. 177-186 ◽  
Author(s):  
Alejandra María Zúñiga-Muñoz ◽  
Israel Pérez-Torres ◽  
Verónica Guarner-Lans ◽  
Elías Núñez-Garrido ◽  
Rodrigo Velázquez Espejel ◽  
...  
Keyword(s):  
Aortic Aneurysm ◽  
Marfan Syndrome ◽  
Aortic Aneurysms ◽  
Aortic Dilatation ◽  
Glutathione S Transferase ◽  
Reduced And Oxidized Glutathione ◽  
Total Antioxidant ◽  
Elevated Activity ◽  
Acute Dissection ◽  
Thoracic Aneurysms

Abstract. Background: Aortic dilatation in Marfan syndrome (MFS) is progressive. It is associated with oxidative stress and endothelial dysfunction that contribute to the early acute dissection of the vessel and can result in rupture of the aorta and sudden death. We evaluated the participation of the glutathione (GSH) system, which could be involved in the mechanisms that promote the formation and progression of the aortic aneurysms in MFS patients. Patients and methods: Aortic aneurysm tissue was obtained during chest surgery from eight control subjects and 14 MFS patients. Spectrophotometrical determination of activity of glutathione peroxidase (GPx), glutathione-S-transferase (GST), glutathione reductase (GR), lipid peroxidation (LPO) index, carbonylation, total antioxidant capacity (TAC), and concentration of reduced and oxidized glutathione (GSH and GSSG respectively), was performed in the homogenate from aortic aneurysm tissue. Results: LPO index, carbonylation, TGF-β1, and GR activity were increased in MFS patients (p < 0.04), while TAC, GSH/GSSG ratio, GPx, and GST activity were significantly decreased (p < 0.04). Conclusions: The depletion of GSH, in spite of the elevated activity of GR, not only diminished the activity of GSH-depend GST and GPx, but increased LPO, carbonylation and decreased TAC. These changes could promote the structural and functional alterations in the thoracic aorta of MFS patients.

scholarly journals Serological level of transforming growth factor-β as a predictive biomarker of aortic enlargement in patients with Marfan syndrome

2017 ◽  
Vol 8 (1) ◽  
pp. 61-66
Author(s):  
Andrey S Rudoy ◽  
Alexey M Uryvaev
Keyword(s):  
Risk Factors ◽  
Growth Factor ◽  
Marfan Syndrome ◽  
Aortic Root ◽  
Transforming Growth Factor ◽  
Aortic Rupture ◽  
Imaging Techniques ◽  
Elevated Serum ◽  
Transforming Growth Factor Β ◽  
Absolute Size

Marfan syndrome - an inherited, autosomal dominant disease with an expected rate of 3-5/10 000 or fraction of 20-25% of new mutations, accompanied by violation of the connective tissue that occurs as a result of gene mutations FBN1, coding for the synthesis of fibrillin-1, performing the most important role in the modulation physiological bioavailability TGF-β (transforming growth factor-β). Prediction of aortic rupture is based on the identification of risk factors: family history, the absolute size of the aortic root, the rate of expansion of the aorta, which are based on the results of the history and techniques of imaging ultrasound, CT, MRI. At the same time there is a chance of developing aortic rupture under normal aortic root size and the absence of any risk factors, as well as after the prophylactic prosthetic aortic root. This makes it necessary to search for alternative prognostic markers, threatening bundle and rupture of the aorta. Article verified the predictive role of TGF-β as a serological biomarker for assessing the extension of the aortic root in patients with Marfan syndrome (n = 23, F : M / 7 : 16; 33 ± 9.3 years). The article describes the patterns between TGF-β and the size and the reconstruction of the aneurysm of the thoracic aorta. It was found that elevated levels of serum TGF-β1 (49.1 ng/ml Vs 29.15 ng/ml in the control, p < 0.05) in patients with MS diagnosed with an extension of the aortic root (Z > 1.96) can serve as a serological marker to poor prognosis, accompanied by an increase in the size of the aortic root. In patients with normal-sized aorta, and after aortic reconstruction serum TGFβ1 not elevated. Serum TGFβ may be a promising target for therapeutic, diagnostic and prognostic tactics which are not based on imaging techniques.

Regional and Layer Distribution of Residual Stresses in an Unloaded Aortic Medial Wall

2020 ◽  
Author(s):  
Atsutaka Tamura ◽  
Koki Matsumoto
Keyword(s):  
Residual Stresses ◽  
Structural Characteristics ◽  
Muscle Layer ◽  
Medial Wall ◽  
Wall Structure ◽  
Aortic Tissue ◽  
Fe Model ◽  
Ring Model ◽  
Unloaded State ◽  
Aortic Media

Abstract The mechanical and structural characteristics of aortic media have profound effects on the physiology and pathophysiology of an aorta. However, many aspects of the aortic tissue remain poorly understood, partly due to the intrinsic layered wall structure and regionally varying residual stresses. Our recent works have demonstrated that a mechanical interaction between the elastic lamina (EL) and smooth muscle layer in the aortic media can be computationally reproduced using a simplified finite element (FE) model. However, it is questionable whether the simplified FE model we created was representative of the structure of a real medial wall and its modeling technique would be applicable to develop a more sophisticated and structure-based aortic FE model. This study aimed to computationally represent EL buckling in the aortic medial ring at an unloaded state and successfully reproduced transmural variation in EL waviness across the aortic wall. We also aimed at confirming the inner and outer layers of the medial wall are subjected to compressive and tensile residual stresses, respectively, at the unloaded state, implying that the ring model will open spontaneously when it is radially cut. Moreover, the computed residual stresses were found to be within the reasonable range of the predicted values, 1–10 kPa, supporting the validity of our modeling approach. Although further study is required, the information obtained here will greatly help improve the understanding of basic aortic physiology and pathophysiology, while simultaneously providing a basis for more sophisticated computational modeling of the aorta.

Abstract 15530: Single-cell Analysis in Aortic Aneurysmal Tissue From Patients With Marfan Syndrome Reveals Increased Tgf-beta Production but Downregulation of Downstream Canonical Tgf-beta Signaling Pathways

Circulation ◽  
2020 ◽  
Vol 142 (Suppl_3) ◽  
Author(s):  
Ashley Dawson ◽  
Yanming Li ◽  
Pingping Ren ◽  
Hernan Vasquez ◽  
Chen Zhang ◽  
...  
Keyword(s):  
Aortic Aneurysm ◽  
Single Cell ◽  
Marfan Syndrome ◽  
Immune Cells ◽  
Single Cell Analysis ◽  
Aortic Aneurysms ◽  
Differentially Expressed ◽  
Aortic Tissue ◽  
Cardiac Transplant ◽  
Tgf Beta

Background: Marfan syndrome (MFS) is caused by mutations in the gene for fibrillin-1 ( FBN1 ); however, the mechanisms by which these mutations cause aortic aneurysms are poorly understood. Although it was hypothesized previously that dysregulation of the complex TGF-β signaling pathway leads to aortic aneurysm formation, FBN1 mutations appear to have a paradoxical effect on TGF-β signaling in MFS. In this study, we evaluated cell-specific TGF-β expression in non-immune cells in MFS aortic tissue. Methods: We performed single-cell RNA sequencing of ascending aortic aneurysm tissues from MFS patients (n=3) undergoing aneurysm repair and age-matched, non-aneurysmal control tissue from cardiac transplant donors and recipients (n=4). Non-immune cells were separated out from the data and analyzed using the Seurat package in R. Differentially expressed genes were identified using edgeR. Results: Conserved gene expression was used to identify populations of smooth muscle cells (SMCs; n=6), fibroblasts (n=3), and endothelial cells (ECs; n=3). We found that TGFB1 was significantly upregulated in quiescent fibroblasts (identified by increased expression of DCN , LUM , and complement factors) with log2FC of 1.30 and FDR 8.25x10 -8 , as well as in activated fibroblasts (identified by increased expression of genes involved in blood vessel repair and healing including ACTA2 , NOTCH3 , THBS2 , and PDGFRB ) with log2FC of 1.25 and FDR 6.15x10 -22 . Despite this increase in TGFB1 , expression of TGF-β receptor genes (predominately TGFBR2 ) as well as downstream SMAD genes was downregulated significantly in the SMC, fibroblast, and endothelial cell clusters. Finally, genes involved in the non-canonical TGF-β pathway, including ERK , JNK, and p38, were not differentially expressed in non-immune cells in MFS compared with control tissues. Conclusion: Increased expression of TGFB1 in non-immune cells in MFS was driven by two clusters of fibroblasts. Despite this, our data do not support associated upregulation of other genes in the canonical or non-canonical TGF-β pathways and in fact support downregulation of canonical TGF-β signaling in non-immune cells of aneurysmal tissues from MFS patients with advanced aortic disease.

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