scholarly journals Ultrastructural Pathology of Atherosclerosis, Calcific Aortic Valve Disease, and Bioprosthetic Heart Valve Degeneration: Commonalities and Differences

2020 ◽  
Vol 21 (20) ◽  
pp. 7434 ◽  
Author(s):  
Alexander Kostyunin ◽  
Rinat Mukhamadiyarov ◽  
Tatiana Glushkova ◽  
Leo Bogdanov ◽  
Daria Shishkova ◽  
...  
Keyword(s):  
Aortic Valve ◽  
Heart Valve ◽  
Aortic Valve Disease ◽  
Circulatory System ◽  
Valve Disease ◽  
Calcium Deposition ◽  
Bioprosthetic Heart Valve ◽  
Calcific Aortic Valve Disease ◽  
Ultrastructural Pathology ◽  
Structural Valve Deterioration

Atherosclerosis, calcific aortic valve disease (CAVD), and bioprosthetic heart valve degeneration (alternatively termed structural valve deterioration, SVD) represent three diseases affecting distinct components of the circulatory system and their substitutes, yet sharing multiple risk factors and commonly leading to the extraskeletal calcification. Whereas the histopathology of the mentioned disorders is well-described, their ultrastructural pathology is largely obscure due to the lack of appropriate investigation techniques. Employing an original method for sample preparation and the electron microscopy visualisation of calcified cardiovascular tissues, here we revisited the ultrastructural features of lipid retention, macrophage infiltration, intraplaque/intraleaflet haemorrhage, and calcification which are common or unique for the indicated types of cardiovascular disease. Atherosclerotic plaques were notable for the massive accumulation of lipids in the extracellular matrix (ECM), abundant macrophage content, and pronounced neovascularisation associated with blood leakage and calcium deposition. In contrast, CAVD and SVD generally did not require vasculo- or angiogenesis to occur, instead relying on fatigue-induced ECM degradation and the concurrent migration of immune cells. Unlike native tissues, bioprosthetic heart valves contained numerous specialised macrophages and were not capable of the regeneration that underscores ECM integrity as a pivotal factor for SVD prevention. While atherosclerosis, CAVD, and SVD show similar pathogenesis patterns, these disorders demonstrate considerable ultrastructural differences.

Abstract P098: Inhibitory Role of Notch1 in Calcific Aortic Valve Disease Is Mediated by Sox9

2011 ◽  
Vol 109 (suppl_1) ◽  
Author(s):  
Chetan P Hans ◽  
Asha Acharya ◽  
Sara N Koenig ◽  
Haley A Nichols ◽  
Cristi L Galindo ◽  
...  
Keyword(s):  
Aortic Valve ◽  
Notch Signaling ◽  
Signaling Pathway ◽  
Aortic Valve Disease ◽  
Notch Signaling Pathway ◽  
Valve Disease ◽  
Calcium Deposition ◽  
Aortic Valve Calcification ◽  
Calcific Aortic Valve Disease ◽  
Valve Calcification

Introduction: Aortic valve calcification is the most common form of valvular heart disease; however the mechanism(s) underlying calcific aortic valve disease (CAVD) are unknown. NOTCH1 mutations are associated with aortic valve malformations and adult-onset calcification in families with inherited disease. The Notch signaling pathway is critical for multiple cell differentiation processes, but its role in the development of CAVD is not well understood. Objective: To investigate the molecular changes associated with the calcification of aortic valve that occurs with inhibition of Notch signaling. Methods and Results: The expression of Notch signaling pathway members was validated in the aortic valve cusps from adult mice, and examination of diseased human aortic valves revealed decreased expression of NOTCH1 in areas of calcium deposition. To identify downstream mediators of Notch1 signaling, we examined gene expression changes that occur with chemical inhibition of Notch signaling in rat aortic valve interstitial cells (AVICs). We found significant downregulation of many cartilage-specific genes that constitute the valve extracellular matrix (ECM). Analysis of these cartilage-specific genes demonstrated that several were transcriptional targets of Sox9, a master regulator of chondrogenesis, which has been previously shown to be essential for proper valve development and maintenance. Utilizing an in vitro porcine aortic valve calcification model system, inhibition of Notch activity resulted in accelerated calcification while stimulation of Notch signaling attenuated the calcific process. Finally, utilizing transfection studies, addition of Sox9 was able to prevent the calcification of porcine AVICs that occurs with Notch inhibition. Conclusions: Loss of Notch signaling contributes to aortic valve calcification by a Sox9-dependent mechanism. Further elucidation of the Notch1-Sox9 molecular pathway and its role in the maintenance of the ECM will lead to an improved mechanistic understanding of aortic valve calcification and development of novel therapeutic strategies for CAVD.

scholarly journals Calcific Aortic Valve Disease: Molecular Mechanisms And Therapeutic Approaches

2015 ◽  
Vol 10 (2) ◽  
pp. 108 ◽  
Author(s):  
Daniel Alejandro Lerman ◽  
Sai Prasad ◽  
Nasri Alotti ◽  
◽  
◽  
...  
Keyword(s):  
Aortic Valve ◽  
Aortic Valve Disease ◽  
Molecular Mechanisms ◽  
Cell Model ◽  
Human Monoclonal Antibody ◽  
Valve Disease ◽  
Vascular Lesions ◽  
Calcium Deposition ◽  
Calcific Aortic Valve Disease

Calcification occurs in atherosclerotic vascular lesions and in the aortic valve. Calcific aortic valve disease (CAVD) is a slow, progressive disorder that ranges from mild valve thickening without obstruction of blood flow, termed aortic sclerosis, to severe calcification with impaired leaflet motion, termed aortic stenosis. In the past, this process was thought to be ‘degenerative’ because of time-dependent wear and tear of the leaflets, with passive calcium deposition. The presence of osteoblasts in atherosclerotic vascular lesions and in CAVD implies that calcification is an active, regulated process akin to atherosclerosis, with lipoprotein deposition and chronic inflammation. If calcification is active, via pro-osteogenic pathways, one might expect that development and progression of calcification could be inhibited. The overlap in the clinical factors associated with calcific valve disease and atherosclerosis provides further support for a shared disease mechanism. In our recent research we used an in vitro porcine valve interstitial cell model to study spontaneous calcification and potential promoters and inhibitors. Using this model, we found that denosumab, a human monoclonal antibody targeting the receptor activator of nuclear factor-κB ligand may, at a working concentration of 50 μg/mL, inhibit induced calcium deposition to basal levels.

Abstract 15192: Leptin Effects on Osteoblast Differentiation of Human Valvular Interstitial Cells: New Insight Into Calcific Aortic Valve Disease

Circulation ◽  
2015 ◽  
Vol 132 (suppl_3) ◽  
Author(s):  
Mickael Rosa ◽  
Rodrigo Lorenzi ◽  
Madjid Tagzirt ◽  
Francis Juthier ◽  
Antoine Rauch ◽  
...  
Keyword(s):  
Aortic Valve ◽  
Aortic Valve Disease ◽  
Osteoblast Differentiation ◽  
Interstitial Cells ◽  
Valve Disease ◽  
Calcium Deposition ◽  
Valvular Interstitial Cells ◽  
Calcific Aortic Valve Disease ◽  
Aortic Valves ◽  
Alp Activity

Introduction: Calcific aortic valve disease (CAVD) affects 2% to 6% of the population over 65 years and results from dysregulated processes such as calcification, supported in part by the osteoblast differentiation of valvular interstitial cells (VIC), the most prevalent cell type in the human aortic valves. Leptin has recently been linked to aortic valve calcification in ApoE-/- mice. Hypothesis: Our hypothesis is that leptin could play a role in the calcifying processes implicated in CAVD via direct effects on human VIC. Methods: Patients who underwent aortic valve replacement for severe CAVD (n=43) or with coronary artery disease (CAD) but without CAVD (n=129) were included in this study. Presence of leptin was analyzed in human explanted calcified aortic valves and blood samples. Leptin receptors expression was analyzed in aortic valves and VIC isolated from aortic valves. Leptin effects on osteoblast differentiation of VIC in presence or not of Akt and ERK inhibitors were investigated by alizarin red staining, alkaline phosphatase (ALP) activity, and RT-qPCR analysis for osteopontin, ALP, bone morphogenetic protein BMP-2, and RUNX2. Results: Patients with CAVD have significant higher serum leptin concentration than CAD patients (p=0.002). The presence of leptin was observed by immunochemistry in human calcified aortic valves, with higher concentrations in calcified vs non-calcified zones (p=0.01). Both short and long leptin receptor isoforms were expressed in VIC. Chronic leptin stimulation of VIC enhanced ALP, BMP-2 and RUNX2 expression and decreased osteopontin expression. This treatment led to a higher, dose dependent, ALP activity and calcium deposition in VIC. Inhibiting Akt or ERK during leptin stimulation led to a reduced calcification by bringing the expression of calcification genes to the control levels. Conclusions: Together, these novel findings depict the potential role of leptin in the process of CAVD by triggering calcification processes in human VIC.

Abstract P332: Microfluidic Model Of Late-stage Calcific Aortic Valve Disease Develops Calcium Phosphate Mineralizations

2021 ◽  
Vol 129 (Suppl_1) ◽  
Author(s):  
Melissa Mendoza ◽  
Mei-Hsiu Chen ◽  
Bruce Murray ◽  
Peter Huang ◽  
Gretchen Mahler
Keyword(s):  
Shear Stress ◽  
Calcium Phosphate ◽  
Aortic Valve ◽  
Late Stage ◽  
Aortic Valve Disease ◽  
Collagen I ◽  
Valve Disease ◽  
Calcium Deposition ◽  
Nodule Formation ◽  
Calcific Aortic Valve Disease

Introduction: Calcific aortic valve disease (CAVD) is an active pathological process leading to severe valve calcification. Late-stage CAVD is characterized by increased leaflet stiffness, disorganized collagen bundles and the deposition of glycosaminoglycans, such as chondroitin sulfate (CS), in the fibrosa layer. However, many details of the cellular pathological cascade remain unknown. Animal models such as mice, rabbits, and pigs are used in understanding human CAVD, but mice do not have similar anatomy, rabbits cannot spontaneously develop atherosclerotic lesions, and pigs require long, expensive and complex studies. Here we utilize microfluidic devices of the aortic valve fibrosa to model late-stage CAVD. Hypothesis: We assessed the hypothesis that microfluidic calcification will increase with increased shear rates and CS content. Methods: Valve-on-a-chip devices contained a hydrogel of 1.5 mg/mL collagen I-only healthy controls or 1.5 mg/mL collagen I with 1 mg/mL or 20 mg/mL CS. Porcine aortic valve interstitial cells (PAVIC) were embedded within and endothelial cells (PAVEC) were seeded onto the matrix. Steady shear stress at 1 dyne/cm 2 and 20 dyne/cm 2 were applied using a peristaltic pump for 14 days. Alizarin Red S (ARS), an assay to assess calcium deposition, was used to quantify calcific nodule formation. Scanning electron microscopy with energy dispersive x-ray (SEM/EDX) was used to further analyze sample mineralization. Results: Co-cultures in the presence of increasing shear stress and CS exhibit increased calcific nodule formation compared to static controls, both qualitatively and quantitatively (n≥3). SEM revealed the microstructure of calcified nodules and EDX confirmed calcium phosphate mineralization with physiologically-relevant calcium to phosphorous ratios (Ca/P= 0.88 - 1.4). Conclusions: These results show that in vitro calcification is driven by shear stress in the presence of PAVEC and CS. As seen in ex vivo studies of human calcification, these microfluidic-derived nodules are similarly composed of a range of naturally-occurring calcium phosphates. Given that CAVD has no targeted therapy, the creation of a physiologically relevant model of the aortic valve can provide a test bed for novel therapeutic interventions.

scholarly journals Lack of periostin leads to suppression of Notch1 signaling and calcific aortic valve disease

2009 ◽  
Vol 39 (3) ◽  
pp. 160-168 ◽  
Author(s):  
Tatiana V. Tkatchenko ◽  
Ricardo A. Moreno-Rodriguez ◽  
Simon J. Conway ◽  
Jeffery D. Molkentin ◽  
Roger R. Markwald ◽  
...  
Keyword(s):  
Aortic Valve ◽  
Embryonic Development ◽  
Cell Fate ◽  
Aortic Valve Disease ◽  
Valve Disease ◽  
Osteogenic Potential ◽  
Calcium Deposition ◽  
Calcific Aortic Valve Disease ◽  
Notch1 Signaling ◽  
Developing Heart

The Postn gene encodes protein periostin. During embryonic development, it is highly expressed in the outflow tract (OFT) endocardial cushions of the developing heart, which give rise to several structures of the mature heart including the aortic valve. Periostin was previously implicated in osteoblast differentiation, cancer metastasis, and tooth and bone development, but its role in cardiac OFT development is unclear. To elucidate the role that periostin plays in the developing heart we analyzed cardiac OFT phenotype in mice after deletion of the Postn gene. We found that lack of periostin in the embryonic OFT leads to ectopic expression of the proosteogenic growth factor pleiotrophin ( Ptn) and overexpression of delta-like 1 homolog (Dlk1), a negative regulator of Notch1, in the distal (prevalvular) cushions of the OFT. This resulted in suppression of Notch1 signaling, strong induction of the central transcriptional regulator of osteoblast cell fate Runx2, upregulation of osteopontin and osteocalcin expression, and subsequent calcification of the aortic valve. Our data suggest that periostin represses a default osteogenic program in the OFT cushion mesenchyme and promotes differentiation along a fibrogenic lineage. Lack of periostin causes derepression of the osteogenic potential of OFT mesenchymal cells, calcium deposition, and calcific aortic valve disease. These results establish periostin as a key regulator of OFT endocardial cushion mesenchymal cell fate during embryonic development.

scholarly journals Evogliptin Suppresses Calcific Aortic Valve Disease by Attenuating Inflammation, Fibrosis, and Calcification

Cells ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 57
Author(s):  
Bongkun Choi ◽  
Eun-Young Kim ◽  
Ji-Eun Kim ◽  
Soyoon Oh ◽  
Si-On Park ◽  
...  
Keyword(s):  
Animal Models ◽  
Aortic Valve ◽  
Aortic Valve Disease ◽  
Rabbit Model ◽  
Cytokine Expression ◽  
Rate Of Change ◽  
Valve Disease ◽  
High Cholesterol Diet ◽  
Calcific Aortic Valve Disease ◽  
Valvular Calcification

Calcific aortic valve disease (CAVD) accompanies inflammatory cell infiltration, fibrosis, and ultimately calcification of the valve leaflets. We previously demonstrated that dipeptidyl peptidase-4 (DPP-4) is responsible for the progression of aortic valvular calcification in CAVD animal models. As evogliptin, one of the DPP-4 inhibitors displays high specific accumulation in cardiac tissue, we here evaluated its therapeutic potency for attenuating valvular calcification in CAVD animal models. Evogliptin administration markedly reduced calcific deposition accompanied by a reduction in proinflammatory cytokine expression in endothelial nitric oxide synthase-deficient mice in vivo, and significantly ameliorated the mineralization of the primary human valvular interstitial cells (VICs), with a reduction in the mRNA expression of bone-associated and fibrosis-related genes in vitro. In addition, evogliptin ameliorated the rate of change in the transaortic peak velocity and mean pressure gradients in our rabbit model as assessed by echocardiography. Importantly, evogliptin administration in a rabbit model was found to suppress the effects of a high-cholesterol diet and of vitamin D2-driven fibrosis in association with a reduction in macrophage infiltration and calcific deposition in aortic valves. These results have indicated that evogliptin prohibits inflammatory cytokine expression, fibrosis, and calcification in a CAVD animal model, suggesting its potential as a selective therapeutic agent for the inhibition of valvular calcification during CAVD progression.

scholarly journals Metabolomics in Severe Aortic Stenosis Reveals Intermediates of Nitric Oxide Synthesis as Most Distinctive Markers

2021 ◽  
Vol 22 (7) ◽  
pp. 3569
Author(s):  
Beau Olivier van van Driel ◽  
Maike Schuldt ◽  
Sila Algül ◽  
Evgeni Levin ◽  
Ahmet Güclü ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Cardiac Surgery ◽  
Aortic Valve ◽  
Aortic Stenosis ◽  
Western Blot ◽  
Aortic Valve Disease ◽  
Metabolic Profile ◽  
Valve Disease ◽  
Healthy Controls ◽  
Calcific Aortic Valve Disease

Background: Calcific aortic valve disease (CAVD) is a rapidly growing global health problem with an estimated 12.6 million cases globally in 2017 and a 112% increase of deaths since 1990 due to aging and population growth. CAVD may develop into aortic stenosis (AS) by progressive narrowing of the aortic valve. AS is underdiagnosed, and if treatment by aortic valve replacement (AVR) is delayed, this leads to poor recovery of cardiac function, absence of symptomatic improvement and marked increase of mortality. Considering the current limitations to define the stage of AS-induced cardiac remodeling, there is need for a novel method to aid in the diagnosis of AS and timing of intervention, which may be found in metabolomics profiling of patients. Methods: Serum samples of nine healthy controls and 10 AS patients before and after AVR were analyzed by untargeted mass spectrometry. Multivariate modeling was performed to determine a metabolic profile of 30 serum metabolites which distinguishes AS patients from controls. Human cardiac microvascular endothelial cells (CMECs) were incubated with serum of the AS patients and then stained for ICAM-1 with Western Blot to analyze the effect of AS patient serum on endothelial cell activation. Results: The top 30 metabolic profile strongly distinguishes AS patients from healthy controls and includes 17 metabolites related to nitric oxide metabolism and 12 metabolites related to inflammation, in line with the known pathomechanism for calcific aortic valve disease. Nine metabolites correlate strongly with left ventricular mass, of which three show reversal back to control values after AVR. Western blot analysis of CMECs incubated with AS patient sera shows a significant reduction (14%) in ICAM-1 in AS samples taken after AVR compared to AS patient sera before AVR. Conclusion: Our study defined a top 30 metabolic profile with biological and clinical relevance, which may be used as blood biomarker to identify AS patients in need of cardiac surgery. Future studies are warranted in patients with mild-to-moderate AS to determine if these metabolites reflect disease severity and can be used to identify AS patients in need of cardiac surgery.

scholarly journals Identification of key genes in calcific aortic valve disease via weighted gene co-expression network analysis

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Jin-Yu Sun ◽  
Yang Hua ◽  
Hui Shen ◽  
Qiang Qu ◽  
Jun-Yan Kan ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Network Analysis ◽  
Aortic Valve ◽  
Aortic Valve Disease ◽  
Expression Profiles ◽  
Enrichment Analysis ◽  
Valve Disease ◽  
Hub Genes ◽  
Calcific Aortic Valve Disease ◽  
Underlying Mechanisms

Abstract Background Calcific aortic valve disease (CAVD) is the most common subclass of valve heart disease in the elderly population and a primary cause of aortic valve stenosis. However, the underlying mechanisms remain unclear. Methods The gene expression profiles of GSE83453, GSE51472, and GSE12644 were analyzed by ‘limma’ and ‘weighted gene co-expression network analysis (WGCNA)’ package in R to identify differentially expressed genes (DEGs) and key modules associated with CAVD, respectively. Then, enrichment analysis was performed based on Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway, DisGeNET, and TRRUST database. Protein–protein interaction network was constructed using the overlapped genes of DEGs and key modules, and we identified the top 5 hub genes by mixed character calculation. Results We identified the blue and yellow modules as the key modules. Enrichment analysis showed that leukocyte migration, extracellular matrix, and extracellular matrix structural constituent were significantly enriched. SPP1, TNC, SCG2, FAM20A, and CD52 were identified as hub genes, and their expression levels in calcified or normal aortic valve samples were illustrated, respectively. Conclusions This study suggested that SPP1, TNC, SCG2, FAM20A, and CD52 might be hub genes associated with CAVD. Further studies are required to elucidate the underlying mechanisms and provide potential therapeutic targets.

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