scholarly journals TLR4 Stimulation Promotes Human AVIC Fibrogenic Activity through Upregulation of Neurotrophin 3 Production

2020 ◽  
Vol 21 (4) ◽  
pp. 1276
Author(s):  
Qingzhou Yao ◽  
Erlinda The ◽  
Lihua Ao ◽  
Yufeng Zhai ◽  
Maren K. Osterholt ◽  
...  
Keyword(s):  
Aortic Valve ◽  
Critical Role ◽  
Chronic Inflammatory Disease ◽  
Collagen Deposition ◽  
Calcific Aortic Valve Disease ◽  
Aortic Valves ◽  
Neurotrophin 3 ◽  
Collagen Iii ◽  
Inflammatory Stimuli ◽  
Stimulation Of

Background: Calcific aortic valve disease (CAVD) is a chronic inflammatory disease that manifests as progressive valvular fibrosis and calcification. An inflammatory milieu in valvular tissue promotes fibrosis and calcification. Aortic valve interstitial cell (AVIC) proliferation and the over-production of the extracellular matrix (ECM) proteins contribute to valvular thickening. However, the mechanism underlying elevated AVIC fibrogenic activity remains unclear. Recently, we observed that AVICs from diseased aortic valves express higher levels of neurotrophin 3 (NT3) and that NT3 exerts pro-osteogenic and pro-fibrogenic effects on human AVICs. Hypothesis: Pro-inflammatory stimuli upregulate NT3 production in AVICs to promote fibrogenic activity in human aortic valves. Methods and Results: AVICs were isolated from normal human aortic valves and were treated with lipopolysaccharide (LPS, 0.20 µg/mL). LPS induced TLR4-dependent NT3 production. This effect of LPS was abolished by inhibition of the Akt and extracellular signal-regulated protein kinases 1 and 2 (ERK1/2) pathways. The stimulation of TLR4 in human AVICs with LPS resulted in a greater proliferation rate and an upregulated production of matrix metallopeptidases-9 (MMP-9) and collagen III, as well as augmented collagen deposition. Recombinant NT3 promoted AVIC proliferation in a tropomyosin receptor kinase (Trk)-dependent fashion. The neutralization of NT3 or the inhibition of Trk suppressed LPS-induced AVIC fibrogenic activity. Conclusions: The stimulation of TLR4 in human AVICs upregulates NT3 expression and promotes cell proliferation and collagen deposition. The NT3-Trk cascade plays a critical role in the TLR4-mediated elevation of fibrogenic activity in human AVICs. Upregulated NT3 production by endogenous TLR4 activators may contribute to aortic valve fibrosis associated with CAVD progression.

scholarly journals Neurotrophin 3 upregulates proliferation and collagen production in human aortic valve interstitial cells: a potential role in aortic valve sclerosis

2017 ◽  
Vol 312 (6) ◽  
pp. C697-C706 ◽  
Author(s):  
Qingzhou Yao ◽  
Rui Song ◽  
Lihua Ao ◽  
Joseph C. Cleveland ◽  
David A. Fullerton ◽  
...  
Keyword(s):  
Aortic Valve ◽  
Cyclin D1 ◽  
Cellular Proliferation ◽  
D1 Protein ◽  
Collagen Deposition ◽  
Aortic Valves ◽  
Aortic Valve Sclerosis ◽  
Collagen Production ◽  
Neurotrophin 3 ◽  
Human Aortic Valve

Calcific aortic valve disease (CAVD) is a leading cardiovascular disorder in the elderly. Diseased aortic valves are characterized by sclerosis (fibrosis) and nodular calcification. Sclerosis, an early pathological change, is caused by aortic valve interstitial cell (AVIC) proliferation and overproduction of extracellular matrix (ECM) proteins. However, the mechanism of aortic valve sclerosis remains unclear. Recently, we observed that diseased human aortic valves overexpress growth factor neurotrophin 3 (NT3). In the present study, we tested the hypothesis that NT3 is a profibrogenic factor to human AVICs. AVICs isolated from normal human aortic valves were cultured in M199 growth medium and treated with recombinant human NT3 (0.10 µg/ml). An exposure to NT3 induced AVIC proliferation, upregulated the production of collagen and matrix metalloproteinase (MMP), and augmented collagen deposition. These changes were abolished by inhibition of the Trk receptors. NT3 induced Akt phosphorylation and increased cyclin D1 protein levels in a Trk receptor-dependent fashion. Inhibition of Akt abrogated the effect of NT3 on cyclin D1 production. Furthermore, inhibition of either Akt or cyclin D1 suppressed NT3-induced cellular proliferation and MMP-9 and collagen production, as well as collagen deposition. Thus, NT3 upregulates cellular proliferation, ECM protein production, and collagen deposition in human AVICs. It exerts these effects through the Trk-Akt-cyclin D1 cascade. NT3 is a profibrogenic mediator in human aortic valve, and overproduction of NT3 by aortic valve tissue may contribute to the mechanism of valvular sclerosis.

scholarly journals Interleukin-37 suppresses the osteogenic responses of human aortic valve interstitial cells in vitro and alleviates valve lesions in mice

2017 ◽  
Vol 114 (7) ◽  
pp. 1631-1636 ◽  
Author(s):  
Qingchun Zeng ◽  
Rui Song ◽  
David A. Fullerton ◽  
Lihua Ao ◽  
Yufeng Zhai ◽  
...  
Keyword(s):  
Aortic Valve ◽  
High Fat Diet ◽  
Aortic Valve Disease ◽  
Valve Disease ◽  
High Fat ◽  
Calcific Aortic Valve Disease ◽  
Aortic Valves ◽  
Valve Interstitial Cells ◽  
Valve Lesions ◽  
Osteogenic Factors

Calcific aortic valve disease is a chronic inflammatory process, and aortic valve interstitial cells (AVICs) from diseased aortic valves express greater levels of osteogenic factors in response to proinflammatory stimulation. Here, we report that lower cellular levels of IL-37 in AVICs of diseased human aortic valves likely account for augmented expression of bone morphogenetic protein-2 (BMP-2) and alkaline phosphatase (ALP) following stimulation of Toll-like receptor (TLR) 2 or 4. Treatment of diseased AVICs with recombinant human IL-37 suppresses the levels of BMP-2 and ALP as well as calcium deposit formation. In mice, aortic valve thickening is observed when exposed to a TLR4 agonist or a high fat diet for a prolonged period; however, mice expressing human IL-37 exhibit significantly lower BMP-2 levels and less aortic valve thickening when subjected to the same regimens. A high fat diet in mice results in oxidized low-density lipoprotein (oxLDL) deposition in aortic valve leaflets. Moreover, the osteogenic responses in human AVICs induced by oxLDL are suppressed by recombinant IL-37. Mechanistically, reduced osteogenic responses to oxLDL in human AVICs are associated with the ability of IL-37 to inhibit NF-κB and ERK1/2. These findings suggest that augmented expression of osteogenic factors in AVICs of diseased aortic valves from humans is at least partly due to a relative IL-37 deficiency. Because recombinant IL-37 suppresses the osteogenic responses in human AVICs and alleviates aortic valve lesions in mice exposed to high fat diet or a proinflammatory stimulus, IL-37 has therapeutic potential for progressive calcific aortic valve disease.

scholarly journals COX-2 Is Downregulated in Human Stenotic Aortic Valves and Its Inhibition Promotes Dystrophic Calcification

2020 ◽  
Vol 21 (23) ◽  
pp. 8917
Author(s):  
Francesco Vieceli Dalla Sega ◽  
Francesca Fortini ◽  
Paolo Cimaglia ◽  
Luisa Marracino ◽  
Elisabetta Tonet ◽  
...  
Keyword(s):  
Aortic Valve ◽  
Clinical Analysis ◽  
Dystrophic Calcification ◽  
Calcific Aortic Valve Disease ◽  
Aortic Valves ◽  
Inflammatory Drugs ◽  
Cox 2 ◽  
Anti Inflammatory ◽  
Induced Apoptosis ◽  
Human Aortic Valve

Calcific aortic valve disease (CAVD) is the result of maladaptive fibrocalcific processes leading to a progressive thickening and stiffening of aortic valve (AV) leaflets. CAVD is the most common cause of aortic stenosis (AS). At present, there is no effective pharmacotherapy in reducing CAVD progression; when CAVD becomes symptomatic it can only be treated with valve replacement. Inflammation has a key role in AV pathological remodeling; hence, anti-inflammatory therapy has been proposed as a strategy to prevent CAVD. Cyclooxygenase 2 (COX-2) is a key mediator of the inflammation and it is the target of widely used anti-inflammatory drugs. COX-2-inhibitor celecoxib was initially shown to reduce AV calcification in a murine model. However, in contrast to these findings, a recent retrospective clinical analysis found an association between AS and celecoxib use. In the present study, we investigated whether variations in COX-2 expression levels in human AVs may be linked to CAVD. We extracted total RNA from surgically explanted AVs from patients without CAVD or with CAVD. We found that COX-2 mRNA was higher in non-calcific AVs compared to calcific AVs (0.013 ± 0.002 vs. 0.006 ± 0.0004; p < 0.0001). Moreover, we isolated human aortic valve interstitial cells (AVICs) from AVs and found that COX-2 expression is decreased in AVICs from calcific valves compared to AVICs from non-calcific AVs. Furthermore, we observed that COX-2 inhibition with celecoxib induces AVICs trans-differentiation towards a myofibroblast phenotype, and increases the levels of TGF-β-induced apoptosis, both processes able to promote the formation of calcific nodules. We conclude that reduced COX-2 expression is a characteristic of human AVICs prone to calcification and that COX-2 inhibition may promote aortic valve calcification. Our findings support the notion that celecoxib may facilitate CAVD progression.

scholarly journals Interstitial cells in calcified aortic valves have reduced differentiation potential and stem cell-like properties

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Maria Bogdanova ◽  
Arsenii Zabirnyk ◽  
Anna Malashicheva ◽  
Katarina Zihlavnikova Enayati ◽  
Tommy Aleksander Karlsen ◽  
...  
Keyword(s):  
Stem Cell ◽  
Aortic Valve ◽  
Collagen Gel ◽  
Interstitial Cells ◽  
Osteogenic Medium ◽  
Calcific Aortic Valve Disease ◽  
Aortic Valves ◽  
Alizarin Red ◽  
Differentiation Potential ◽  
Lower Expression

Abstract Valve interstitial cells (VICs) are crucial in the development of calcific aortic valve disease. The purpose of the present investigation was to compare the phenotype, differentiation potential and stem cell-like properties of cells from calcified and healthy aortic valves. VICs were isolated from human healthy and calcified aortic valves. Calcification was induced with osteogenic medium. Unlike VICs from healthy valves, VICs from calcified valves cultured without osteogenic medium stained positively for calcium deposits with Alizarin Red confirming their calcific phenotype. Stimulation of VICs from calcified valves with osteogenic medium increased calcification (p = 0.02), but not significantly different from healthy VICs. When stimulated with myofibroblastic medium, VICs from calcified valves had lower expression of myofibroblastic markers, measured by flow cytometry and RT-qPCR, compared to healthy VICs. Contraction of collagen gel (a measure of myofibroblastic activity) was attenuated in cells from calcified valves (p = 0.04). Moreover, VICs from calcified valves, unlike cells from healthy valves had lower potential to differentiate into adipogenic pathway and lower expression of stem cell-associated markers CD106 (p = 0.04) and aldehyde dehydrogenase (p = 0.04). In conclusion, VICs from calcified aortic have reduced multipotency compared to cells from healthy valves, which should be considered when investigating possible medical treatments of aortic valve calcification.

scholarly journals Mechanistic Roles of Matrilin-2 and Klotho in Modulating the Inflammatory Activity of Human Aortic Valve Cells

Cells ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 385
Author(s):  
Erlinda The ◽  
Qingzhou Yao ◽  
Peijian Zhang ◽  
Yufeng Zhai ◽  
Lihua Ao ◽  
...  
Keyword(s):  
Aortic Valve ◽  
Inflammatory Responses ◽  
Chronic Inflammatory Disease ◽  
Inflammatory Activity ◽  
Protein Kinase R ◽  
Calcific Aortic Valve Disease ◽  
Inflammatory Mediator Production ◽  
Human Aortic Valve ◽  
Molecular Patterns ◽  
Damage Associated Molecular Patterns

Background: Calcific aortic valve disease (CAVD) is a chronic inflammatory disease. Soluble extracellular matrix (ECM) proteins can act as damage-associated molecular patterns and may induce valvular inflammation. Matrilin-2 is an ECM protein and has been found to elevate the pro-osteogenic activity in human aortic valve interstitial cells (AVICs). Klotho, an anti-aging protein, appears to have anti-inflammatory properties. The effect of matrilin-2 and Klotho on AVIC inflammatory responses remains unclear. Methods and Results: Isolated human AVICs were exposed to matrilin-2. Soluble matrilin-2 induced the production of ICAM-1, MCP-1, and IL-6. It also induced protein kinase R (PKR) activation via Toll-like receptor (TLR) 2 and 4. Pretreatment with PKR inhibitors inhibited NF-κB activation and inflammatory mediator production induced by matrilin-2. Further, recombinant Klotho suppressed PKR and NF-κB activation and markedly reduced the production of inflammatory mediators in human AVICs exposed to matrilin-2. Conclusions: This study revealed that soluble matrilin-2 upregulates AVIC inflammatory activity via activation of the TLR-PKR-NF-κB pathway and that Klotho is potent to suppress AVIC inflammatory responses to a soluble ECM protein through inhibiting PKR. These novel findings indicate that soluble matrilin-2 may accelerate the progression of CAVD by inducing valvular inflammation and that Klotho has the potential to suppress valvular inflammation.

scholarly journals Nitric oxide prevents aortic valve calcification by S-nitrosylation of USP9X to activate NOTCH signaling

2021 ◽  
Vol 7 (6) ◽  
pp. eabe3706
Author(s):  
Uddalak Majumdar ◽  
Sathiyanarayanan Manivannan ◽  
Madhumita Basu ◽  
Yukie Ueyama ◽  
Mark C. Blaser ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Aortic Valve ◽  
Notch Pathway ◽  
Rna Seq ◽  
Calcific Aortic Valve Disease ◽  
Aortic Valves ◽  
Proteomic Approach ◽  
Ubiquitin Proteasome ◽  
Proteasome Pathway ◽  
Genetic Deletion

Calcific aortic valve disease (CAVD) is an increasingly prevalent condition, and endothelial dysfunction is implicated in its etiology. We previously identified nitric oxide (NO) as a calcification inhibitor by its activation of NOTCH1, which is genetically linked to human CAVD. Here, we show NO rescues calcification by an S-nitrosylation–mediated mechanism in porcine aortic valve interstitial cells and single-cell RNA-seq demonstrated NO regulates the NOTCH pathway. An unbiased proteomic approach to identify S-nitrosylated proteins in valve cells found enrichment of the ubiquitin-proteasome pathway and implicated S-nitrosylation of USP9X (ubiquitin specific peptidase 9, X-linked) in NOTCH regulation during calcification. Furthermore, S-nitrosylated USP9X was shown to deubiquitinate and stabilize MIB1 for NOTCH1 activation. Consistent with this, genetic deletion of Usp9x in mice demonstrated CAVD and human calcified aortic valves displayed reduced S-nitrosylation of USP9X. These results demonstrate a previously unidentified mechanism by which S-nitrosylation–dependent regulation of a ubiquitin-associated pathway prevents CAVD.

scholarly journals Decreased Glucagon-Like Peptide-1 Is Associated With Calcific Aortic Valve Disease: GLP-1 Suppresses the Calcification of Aortic Valve Interstitial Cells

2021 ◽  
Vol 8 ◽  
Author(s):  
Fan Xiao ◽  
Qing Zha ◽  
Qianru Zhang ◽  
Qihong Wu ◽  
Zhongli Chen ◽  
...  
Keyword(s):  
Aortic Valve ◽  
Aortic Valve Disease ◽  
Interstitial Cells ◽  
Valve Disease ◽  
Dependent Manner ◽  
Calcific Aortic Valve Disease ◽  
Aortic Valves ◽  
Valve Interstitial Cells ◽  
Glucagon Like Peptide ◽  
Glucagon Like Peptide 1

Objectives: This study explores the concentration and role of glucagon-like peptide-1 (GLP-1) in calcific aortic valve disease (CAVD).Background: Calcific aortic valve disease is a chronic disease presenting with aortic valve degeneration and mineralization. We hypothesized that the level of GLP-1 is associated with CAVD and that it participates in the calcification of aortic valve interstitial cells (AVICs).Methods: We compared the concentration of GLP-1 between 11 calcific and 12 normal aortic valve tissues by immunohistochemical (IHC) analysis. ELISA was used to measure GLP-1 in serum of the Control (n = 197) and CAVD groups (n = 200). The effect of GLP-1 on the calcification of AVICs and the regulation of calcific gene expression were also characterized.Results: The GLP-1 concentration in the calcific aortic valves was 39% less than that in the control non-calcified aortic valves. Its concentration in serum was 19.3% lower in CAVD patients. Multivariable regression analysis demonstrated that GLP-1 level was independently associated with CAVD risk. In vitro, GLP-1 antagonized AVIC calcification in a dose- and time-dependent manner and it down-regulated RUNX2, MSX2, BMP2, and BMP4 expression but up-regulated SOX9 expression.Conclusions: A reduction in GLP-1 was associated with CAVD, and GLP-1 participated in the mineralization of AVICs by regulating specific calcific genes. GLP-1 warrants consideration as a novel treatment target for CAVD.

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.

Cadherin-11 Regulates Calcific Nodule Formation by Aortic Valve Interstitial Cells

2013 ◽  
Author(s):  
Joseph Chen ◽  
Joshua D. Hutcheson ◽  
M. K. Sewell-Loftin ◽  
Larisa M. Ryzhova ◽  
Charles I. Fisher ◽  
...  
Keyword(s):  
Aortic Valve ◽  
Transforming Growth Factor ◽  
Critical Role ◽  
Transforming Growth Factor Β1 ◽  
Interstitial Cells ◽  
In Vitro Models ◽  
Nodule Formation ◽  
Calcific Aortic Valve Disease ◽  
Valve Interstitial Cells

Calcific aortic valve disease (CAVD) is characterized by the stiffening and calcification of the aortic valve leaflets which result in impaired valve function and increased load on the myocardium. In vitro models of CAVD involve the formation the calcific nodules via aortic valve interstitial cells (AVICs). Transforming growth factor β1 (TGF-β1) induced myofibroblast differentiation of AVICs, which is evidenced by increased αSMA expression, has been shown to be a key mediator of dystrophic calcific nodule formation. Benton et al. demonstrated the critical role of αSMA in nodule formation in that when αSMA was suppressed, calcific nodules did not form [1]. Confoundingly, preventing phosphorylation of Erk1/2 with a MEK1/2 inhibitor leads to increased αSMA expression yet prevents calcific nodule formation [2], suggesting the requirement of another essential component of nodule formation that has yet to be revealed.

Calcification and extracellular matrix dysregulation in human postmortem and surgical aortic valves

Heart ◽  
2019 ◽  
Vol 105 (21) ◽  
pp. 1616-1621 ◽  
Author(s):  
M Victoria Gomez-Stallons ◽  
Justin T Tretter ◽  
Keira Hassel ◽  
Osniel Gonzalez-Ramos ◽  
Dorothy Amofa ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Aortic Valve ◽  
In Vivo Imaging ◽  
Progressive Disease ◽  
Calcific Aortic Valve Disease ◽  
Aortic Valves ◽  
Valve Dysfunction ◽  
Intrinsic Form ◽  
Severe Calcification

ObjectivesCalcific aortic valve disease (CAVD) is a progressive disease ranging from aortic valve (AoV) sclerosis to AoV stenosis (AS), characterised by severe calcification with impaired leaflet function. Due to the lack of early symptoms, the pathological progression towards valve dysfunction is poorly understood. The early patterns of AoV calcification and altered extracellular matrix (ECM) organisation were analysed in individuals postmortem without clinical AS compared with clinical AS.MethodsHistological patterns of calcification and ECM organisation in postmortem AoV leaflets without clinical AS obtained from a tissue repository and surgical specimens obtained from individuals with clinical AS were compared with in vivo imaging prior to transcatheter AoV implantation.ResultsAoV calcification was detected in all samples from individuals >50 years old, with severity increasing with age, independent of known CAVD risk factors. Two distinct types of calcification were identified: ‘Intrinsic’, primarily found at the leaflet hinge of postmortem leaflets, accompanied by abnormal collagen and proteoglycan deposition; and ‘Nodular’, extending from the middle to the tip regions in more severely affected postmortem leaflets and surgical specimens, associated with increased elastin fragmentation and loss of elastin integrity. Even in the absence of increased thickening, abnormalities in ECM composition were observed in postmortem leaflets without clinical AS and worsen in clinical AS.ConclusionsTwo distinct phenotypes of AoV calcification are apparent. While the ‘nodular’ form is recognised on in vivo imaging and is present with CAVD and valve dysfunction, it is unclear if the ‘intrinsic’ form is pathological or detected on in vivo imaging.

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