Dynamically-Loaded 3-D Model to Study the ECM Organization of Aortic Smooth Muscle Cells in Aneurysmal Patients With Bicuspid Aortic Valve

Author(s):  
Wei He ◽  
Julie Phillippi ◽  
Christopher E. Miller ◽  
David A. Vorp ◽  
Thomas G. Gleason

Rupture of aortic aneurysms and dissections are the fifteenth leading cause of a death in the United States [1]. Over 40% of patients undergoing elective surgery for ascending aortic replacement due to thoracic aortic aneurysm (TAA) have a congenital defect in the aortic valve know as bicuspid aortic valve (BAV) [2]. BAV patients have uniformly larger diameter aortic roots and ascending aortas compared to age- and sex-matched controls [3] and abnormal elasticity even in the absence of valvular stenosis or aneurysm [4] and this greatly increases the risk of aortic dissection and sudden death [5]. The cause of TAA is uncertain, but recent studies suggest that oxidative stress may play a role in the pathogenesis of TAAs by degrading the extracellular matrix (ECM). We identified that BAV smooth muscle cells (SMCs) lack sufficient resistance to reactive oxygen species to maintain ECM homeostasis [6, 7].

2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Anna Malashicheva ◽  
Daria Kostina ◽  
Aleksandra Kostina ◽  
Olga Irtyuga ◽  
Irina Voronkina ◽  
...  

Thoracic aortic aneurysm develops as a result of complex series of events that alter the cellular structure and the composition of the extracellular matrix of the aortic wall. The purpose of the present work was to study the cellular functions of endothelial and smooth muscle cells from the patients with aneurysms of the thoracic aorta. We studied endothelial and smooth muscle cells from aneurysms in patients with bicuspid aortic valve and with tricuspid aortic valve. The expression of key markers of endothelial (CD31, vWF, and VE-cadherin) and smooth muscle (SMA, SM22α, calponin, and vimentin) cells as well extracellular matrix and MMP activity was studied as well as and apoptosis and cell proliferation. Expression of functional markers of endothelial and smooth muscle cells was reduced in patient cells. Cellular proliferation, migration, and synthesis of extracellular matrix proteins are attenuated in the cells of the patients. We show for the first time that aortic endothelial cell phenotype is changed in the thoracic aortic aneurysms compared to normal aortic wall. In conclusion both endothelial and smooth muscle cells from aneurysms of the ascending aorta have downregulated specific cellular markers and altered functional properties, such as growth rate, apoptosis induction, and extracellular matrix synthesis.


EBioMedicine ◽  
2019 ◽  
Vol 43 ◽  
pp. 54-66 ◽  
Author(s):  
Brittany Balint ◽  
Hao Yin ◽  
Zengxuan Nong ◽  
John-Michael Arpino ◽  
Caroline O'Neil ◽  
...  

2019 ◽  
Vol 20 (19) ◽  
pp. 4782 ◽  
Author(s):  
Christian Stern ◽  
Bernhard Scharinger ◽  
Adrian Tuerkcan ◽  
Clemens Nebert ◽  
Teresa Mimler ◽  
...  

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.


2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
S.K Ghadge ◽  
M Messner ◽  
H Seiringer ◽  
T Zeller ◽  
D Boernigen ◽  
...  

Abstract Background Stromal cell-derived factor-1 (SDF-1 or CXCL12) and its receptors CXCR4/CXCR7 have prominent role in cardiovascular development and myocardial repair following ischemic injury. Nevertheless, detailed mechanisms of the cell specific role of SDF-1 are poorly understood. Since SDF-1-EGFP lineage tracking revealed high expression of SDF-1 in smooth muscle cells, we aimed to investigate the cell specific role by generating a smooth muscle cell specific SDF-1 (SM-SDF-1−/−) knockout mouse model. Methods SDF-1 expression was analyzed utilizing SDF-1-EGFP reporter mice. Conditional SM-SDF-1 KO mice were generated using Tagln-Cre; SDF-1fl/fl mice. Hearts were analysed with histology and high-resolution episcopic microscopy. Cardiac function was assessed utilizing echocardiography. RNAseq, qRT-PCR, flow cytometry and western blotting were performed. Cardiac fibrosis, apoptotic index, cell proliferation, aortic valve calcification were analyzed. SM-SDF-1−/− mice were treated with the CXCR7 agonist TC14012 (10mg/kg/I.P). Results SDF-1-EGFP lineage tracking and immunofluorescence revealed high expression of SDF-1 particularly in smooth muscle cells and less frequently in perivascular and endothelial cells. Conditional SM-SDF-1−/− mice showed a high pre- and perinatal mortality (50%). Immunohistochemistry of SM-SDF-1−/− mice revealed severe cardiac hypertrophy, associated with increased cardiac fibrosis, apoptotic cell death, thinned and dilated arteries and significantly decreased M2 like CD11b+/CD206+ cells. Echocardiography confirmed concentric hypertrophy, with decreased stroke volume. As a possible reason for cardiac hypertrophy, SDF-1 mutants exhibited aortic stenosis due to aortic valve thickening associated with downregulation of the SDF-1 co-receptor CXCR7. We further noticed increased plasma levels of SDF-1 in aortic stenosis patients suggesting a cardioprotective role. Transcriptome analyses from KO hearts showed an abnormal extracellular matrix (ECM) remodelling with a specific upregulation of the important valve related proteoglycans Versican, Glycan. Western blot analysis revealed activation of AKT and ERK, whereas CXCR7 expression was significantly downregulated in KO mice. To rescue the phenotype we treated KO mice with the CXCR7 agonist (TC14012) which partially attenuated aortic valve remodelling through activation of the ERK signalling pathway. Conclusion Our data suggest that SDF-1 is critically involved in maintaining the homeostasis of the aortic valve by regulating CXCR7 signalling. Pharmacological activation of CXCR7 might be a promising therapeutic target to limit the progression of aortic valve stenosis. Ghadge_SM-SDF-1−/− Funding Acknowledgement Type of funding source: Public grant(s) – National budget only. Main funding source(s): Austrian Science Fund, Austrian research promotion agency


2014 ◽  
Vol 34 (suppl_1) ◽  
Author(s):  
Anna Zampetaki ◽  
Xiaoke Yin ◽  
Ursula Mayr ◽  
Renata Gomes ◽  
Sarah Langley ◽  
...  

Rationale: Extracellular matrix (ECM) remodeling is a key function of vascular smooth muscle cells (SMCs). MicroRNAs (miRNAs), in particular the miR-29 family and miR-195, have been implicated in the control of ECM secretion. Objective: To perform a proteomics comparison of miRNA effects on ECM production by vascular SMCs. Methods and Results: Murine SMCs were transfected with miRNA mimics and antimiRs of miR-29b and miR-195, and their conditioned medium was analyzed by mass spectrometry. Both miRNAs targeted a cadre of ECM proteins, including proteoglycans, collagens, proteases, elastin and proteins associated with elastic microfibrils, albeit miR-29 showed a stronger effect. The proteomics findings were subsequently validated at the transcription level using quantitative polymerase chain reaction. Similar to miR-29, in vivo inhibition of miR-195 by intraperitoneal injection of cholesterol bound antagomiRs led to significant alterations of elastin expression in murine aortas. Since elastin degradation is a key event in aortic aneurysm formation, we investigated miR-195 expression in patients. In human aortic aneurysmal tissue, miR-195 expression was reduced compared to non-aneurysmal tissue. In plasma, a comparison between male patients with abdominal aortic aneurysms and controls matched for diabetes and hypertension returned a panel of five highly correlated miRNAs: miR-195, miR-125b, miR-148a, miR-20a and miR-340 showed significant inverse associations with the presence of abdominal aortic aneurysms and aortic diameter, with miR-195 dominating in terms of association strength. Conclusions: Using proteomic analysis, we compared the effect of miR-29 and miR-195 on ECM secretion by vascular SMCs and identified novel miRNA targets. Findings in patients support an important role for miR-195 in vascular remodeling as evidenced by reduced miR-195 expression in human aneurysmal tissue and an inverse correlation between plasma miR-195 levels and aortic diameter.


2014 ◽  
Vol 38 ◽  
pp. 238-252
Author(s):  
Ceyda AÇILAN AYHAN ◽  
Betül BAYKAL ◽  
Müge SERHATLI ◽  
Ömer KAÇAR ◽  
Zelal ADIGÜZEL ◽  
...  

2018 ◽  
Vol 25 (1_suppl) ◽  
pp. 42-50 ◽  
Author(s):  
Anna Chiarini ◽  
Francesco Onorati ◽  
Maddalena Marconi ◽  
Alessandra Pasquali ◽  
Cristina Patuzzo ◽  
...  

Background Sporadic non-syndromic thoracic aortic aneurysms (SNSTAAs) are less well understood than familial non-syndromic or syndromic ones. The study aimed at defining the peculiar morphologic and molecular changes occurring in the media layer of SNSTAAs. Design This study was based on a single centre design. Methods Media layer samples taken from seven carefully selected SNSTAAs and seven reference patients (controls) were investigated via quantitative polymerase chain reaction, proteomics-bioinformatics, immunoblotting, quantitative histology, and immunohistochemistry/immunofluorescence. Results In SNSTAAs media, aortic smooth muscle cells numbers were halved due to an apoptotic process coupled with a negligible cell proliferation. Cystathionine γ-lyase was diffusely up-regulated. Surviving aortic smooth muscle cells exhibited diverging phenotypes: in inner- and outer-media contractile cells prevailed, having higher contents of smooth-muscle-α-actin holoprotein (45-kDa) and of caspase-3-cleaved smooth-muscle-α-actin 25-kDa fragments; in mid-media, aortic smooth muscle cells exhibited a synthetic/secretor phenotype, down-regulating vimentin, but up-regulating glial fibrillary acidic protein, trans-Golgi network 46 protein, Jagged1 (172-kDa) holoprotein, and Jagged1’s receptor Notch1. Extracellular soluble Jagged1 (42-kDa) fragments accumulated. Conclusions In SNSTAAs, there is a relentless aortic smooth muscle cells attrition caused by the up-regulated cystathionine γ-lyase. In mid-media, synthetic/secretor aortic smooth muscle cells intensify Jagged1/NOTCH1 signalling in the attempt to counterbalance the weakened aortic wall, due to aortic smooth muscle cells net loss and mechanical stress. Synthetic/secretor aortic smooth muscle cells are apoptosis-prone, and the accruing thrombin-cleaved Jagged1 fragments counteract the otherwise useful effects of Jagged1/NOTCH1 signalling, thus hampering tissue homeostasis/remodelling, and aortic smooth muscle cells adhesion, differentiation, and migration.


2012 ◽  
Vol 2012 ◽  
pp. 1-16 ◽  
Author(s):  
Katie L. Losenno ◽  
Robert L. Goodman ◽  
Michael W. A. Chu

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.


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