Development Of Aortic Valve Stenosis Research Articles

Molecular Linkage under the Bicuspid Aortic Valve with Dyslipidemia.

Dyslipidemia is correlated with diverse cardiovascular problems, such as obesity, hypertension, and atherosclerosis, which are summarized as metabolic syndrome. Bicuspid aortic valve (BAV), as one of the congenital heart defects, is shown to influence approximately 2.2% of the general population worldwide, inducing the severe pathological development of aortic valve stenosis (AVS) or aortic valve regurgitation (AVR), and also to aortic dilatation. Notably, emerging evidence showed that BAV was correlated with not only the aortic valve and wall diseases but also the dyslipidemic related cardiovascular disorders. Recent results also proposed that multiple potential molecular mechanisms inducing the progression of dyslipidemia played important roles in BAV and the progression of AVS. Several altered serum biomarkers under dyslipidemic condition, including higher low-density lipoprotein cholesterol (LDL-C), higher lipoprotein (a) [Lp(a)], lower high-density lipoprotein cholesterol (HDL-C), and different pro-inflammatory signaling pathways, have proposed to embrace a vital function in the development of BAV correlated cardiovascular diseases. In this review, different molecular mechanisms which embrace an important role in personalized prognosis in the subjects with BAV was summarized. The illustration of those mechanisms might facilitate an accurate follow-up for patients with BAV and give new pharmacological strategies to improve development of dyslipidemia and BAV.

Toll-like receptor-3 contributes to the development of aortic valve stenosis

Aortic valve stenosis (AS) development is driven by distinct molecular and cellular mechanisms which include inflammatory pathways. Toll-like-receptor-3 (TLR3) is a lysosomal pattern-recognition receptor that binds double-stranded RNA and promotes pro-inflammatory cellular responses. In recent years, TLR3 has emerged as a major regulator of vascular inflammation. The exact role of TLR3 in the development of AS has not been investigated. Isolated human valvular interstitial cells (VICs) were stimulated with the TLR3-agonist polyIC and the resulting pro-inflammatory and pro-osteogenic response measured. Severe AS was induced in wildtype- and TLR3−/− mice via mechanical injury of the aortic valve with a coronary springwire. TLR3 activation was achieved by polyIC injection every 24 h after wire injury, while TLR3 inhibition was realized using Compound 4a (C4a) every 48 h after surgery. Endothelial mesenchymal transition (EndoMT) of human valvular endothelial cells (VECs) was assessed after polyIC stimulation. Stimulation of human VICs with polyIC promoted a strong inflammatory and pro-osteogenic reaction. Similarly, injection of polyIC marginally increased AS development in mice after wire injury. AS induction was significantly decreased in TLR3−/− mice, confirming the role of endogenous TLR3 ligands in AS pathology. Pharmacological inhibition of TLR3 with C4a not only prevented the upregulation of inflammatory cytokines and osteogenic markers in VICs, and EndoMT in VECs, but also significantly abolished the development of AS in vivo. Endogenous TLR3 activation significantly contributes to AS development in mice. Pharmacological inhibition of TLR3 with C4a prevented AS formation. Therefore, targeting TLR3 may be a viable treatment option.

The contribution of amyloid deposition in the aortic valve to calcification and aortic stenosis.

Calcific aortic valve disease (CAVD) and stenosis have a complex pathogenesis, and no therapies are available that can halt or slow their progression. Several studies have shown the presence of apolipoprotein-related amyloid deposits in close proximity to calcified areas in diseased aortic valves. In this Perspective, we explore a possible relationship between amyloid deposits, calcification and the development of aortic valve stenosis. These amyloid deposits might contribute to the amplification of the inflammatory cycle in the aortic valve, including extracellular matrix remodelling and myofibroblast and osteoblast-like cell proliferation. Further investigation in this area is needed to characterize the amyloid deposits associated with CAVD, which could allow the use of antisense oligonucleotides and/or isotype gene therapies for the prevention and/or treatment of CAVD.

Angiopoietin-like 2 is essential to aortic valve development in mice

Aortic valve (AoV) abnormalities during embryogenesis are a major risk for the development of aortic valve stenosis (AVS) and cardiac events later in life. Here, we identify an unexpected role for Angiopoietin-like 2 (ANGPTL2), a pro-inflammatory protein secreted by senescent cells, in valvulogenesis. At late embryonic stage, mice knocked-down for Angptl2 (Angptl2-KD) exhibit a premature thickening of AoV leaflets associated with a dysregulation of the fine balance between cell apoptosis, senescence and proliferation during AoV remodeling and a decrease in the crucial Notch signalling. These structural and molecular abnormalities lead toward spontaneous AVS with elevated trans-aortic gradient in adult mice of both sexes. Consistently, ANGPTL2 expression is detected in human fetal semilunar valves and associated with pathways involved in cell cycle and senescence. Altogether, these findings suggest that Angptl2 is essential for valvulogenesis, and identify Angptl2-KD mice as an animal model to study spontaneous AVS, a disease with unmet medical need.

Abstract 14024: Role of Endothelial CXCR4 on the Development of Aortic Valve Stenosis

Background. CXCL12/CXCR4 signaling is essential in cardiac development and repair, however, its contribution to the Aortic valve stenosis (AVS) remains unclear. In this study, we tested the role of endothelial CXCR4 on the development of AVS. Methods. We generated CXCR4 endothelial cell-specific knockout mice (EC CXCR4 KO) by crossing CXCR4 fl/fl mouse with Tie2-Cre mouse to study the role of endothelial cell CXCR4 in AVS. CXCR4 fl/fl mice with no Tie2-Cre gene present were used as control. Echocardiography was used to assess the aortic valve and cardiac function. Heart samples containing the aortic valve were stained using Alizarin Red for detection of calcification. Masson’s Trichrome staining was used for the detection of fibrosis. Apex samples were stained with wheat germ agglutinin to visualize ventricular hypertrophy. Results. Compared with the control group, the deletion of CXCR4 in endothelial cells led to significantly increased aortic valve peak velocity and aortic valve peak pressure gradient, and decreased aortic valve area and ejection fraction. EC CXCR4 KO mice also developed cardiac hypertrophy evidenced by increased left ventricular mass, diastolic and systolic left ventricle posterior wall (LVPW), cardiac myocyte size, and heart weight (HW) to body weight (BW) ratio. Our data also confirmed increased microcalcifications, interstitial fibrosis, and thickened valvular leaflets of the EC CXCR4 KO mice. Conclusions. We found that the deletion of CXCR4 in endothelial cells leads to aortic valve stenosis and left ventricular hypertrophy. This indicates endothelial cell CXCR4 plays a protective role against AVS, and EC CXCR4 KO mice can be used as a novel model for AVS study.

Abstract 12021: Investigation of the Role of Long Non-Coding RNA H19 on Endothelial to Mesenchymal Transition in Aortic Valve Stenosis

Background: Endothelial to mesenchymal transition (EndMT) is a transdifferentiation process of cells that is associated with the development of aortic valve stenosis (AVS) in adulthood. It was shown that long non-coding RNAs are dysregulated in this process and might play a crucial role in EndMT-mediated AVS. Here we aim to elucidate the role of long non-coding RNA H19 (LncRNA H19) in the pathogenesis of EndMT-related AVS. Methods and Results: RNA sequencing of aortic valve tissue explanted from AVS-patients with coronary artery disease (CAD) revealed that H19 was significantly dysregulated. EndMT was induced in vitro in vascular and valvular endothelial cells (VECs) via TNFα and TGFß+IL1ß stimulation and expression of endothelial marker genes vWF and eNOS and mesenchymal marker genes αSMA , SM22 , Vimentin and SNAI2 was confirmed by RT-qPCR. Loss of function of H19 followed by EndMT induction demonstrated distinct changes in gene expression profile and protein levels which were detected by qRT-PCR, immunoblotting, and immunofluorescence. Further experiments indicate that loss of H19 may promote EndMT. Functional assays in vascular and valvular endothelial cells suggested that H19 is a critical regulator of angiogenic sprouting and migration. To unveil the specific molecular signature in angiogenesis a RT 2 profiler array was performed to identify the regulation of angiogenesis with 84 angiogenesis-related genes. Our assay revealed JAG1 as a potential dysregulated candidate with a 4.43-fold regulation. Further molecular mechanism will be investigated via identification of binding partners and downstream targets of H19 in EndMT by using primary cells and VECs. Conclusion: Our data suggests that H19 might play a role in EndMT in context of AVS. Further investigation by using a murine model of AVS should confirm the H19-mediated of EndMT in the development of AVS.

Abstract 12584: The Role of Toll-Like Receptor 3 in the Development of Aortic Valve Stenosis

Background: Our current concept of aortic valve stenosis (AS) development suggests that local chronic inflammation drives fibrosis and calcification of the valve cusps. This remodeling is driven by endothelial to mesenchymal transition (EndMT) of valvular endothelial cells (VECs) and by calcification of valvular interstitial cells (VICs). In a preliminary screening, we found Toll-like receptor 3 (TLR3) expression increased in human AS samples. Therefore, aim of this study was to investigate the role of TLR3 in the pathogenesis of AS. Methods/Results: We confirmed TLR3 expression in cultured human VICs and VECs. Upon specific TLR3 stimulation with PolyI:C, both VICs and VECs displayed a positive feedback with increased TLR3 expression. Concomitant treatment of PolyI:C-stimulated VICs and VECs with the TLR3/RNA complex inhibitor (C4a) significantly blunted this response. Importantly, the TLR3-mediated pro-inflammatory and calcifying response of VICs and EndMT by VECs was significantly reduced by TLR3-inhibtion with C4a.To examine the role or TLR3 in AS development, a wire injury induced AS mouse model was used. Valves were explanted and stained with hematoxylin/eosin, Sirius red, von Kossa, or anti CD68. PolyI:C treatment promoted AS, as demonstrated by increased valve cusp thickness and pronounced valvular inflammation. Interestingly, AS development was nearly absent in TLR3 deficient mice suggesting a critical role of endogenous TLR3 ligands in this model. Treatment of mice with C4a after wire-injury of the aortic valve significantly reduced both morphological and functional parameters of AS development. Conclusion: These findings not only support the role of endogenous TLR3 activation in the development of AS but suggest that specific TLR3 inhibition might be beneficial for the treatment or prevention of AS. Further studies are required to decipher the exact mechanisms how TLR3 contributes to AS.

Loss of ceramide synthase 5 reduces the development of aortic valve stenosis in mice with high fat diet

Abstract Background Ceramide synthase 5 (CerS5) is essential to maintain C:16 ceramide levels in mice. Ceramides contribute to inflammation and calcification, two hallmarks of aortic valve stenosis development. It is known, that loss of CerS5 function reduces diet-induced obesity. Purpose The aim of this study was to investigate the effect of ceramide synthase 5 and high-fat diet on the development of aortic valve stenosis with a mouse model. Methods Our experiment consists of four groups of mice: Wild type (WT) and CerS5 (−/−) mice, with normal and high fat diet. We induced the aortic valve stenosis development through a wire-injury. For this model, a coronary angiography wire is introduced into the left ventricle over the right carotid artery, followed by rotation on the aortic valve level to generate a defined injury. Development of aortic valve stenosis was determined by measuring the peak velocity 14, 28 and 42 days after the wire-injury. With histological analysis of the aortic valve, we measured macrophage infiltration with CD68 immunostaining and calcification using von Kossa staining. For statistical analysis ANOVA and Turkeys multiple comparisons were performed. Results Histological analysis of the aortic valve revealed, that in CerS5 (−/−) mice with high fat diet (HFD) immune cell infiltration is reduced, while there is no difference between CerS5 (−/−) mice and wild type, when fed with normal diet (A). Also calcification showed a trend towards a reduction in CerS5 mice with high fat diet, but was not statistically significant (B). Echocardiography could detect a reduced peak velocity of CerS5 mice with high fat diet, in comparison to the other groups, four and six weeks after wire injury (C). Conclusion Our experiments indicate that loss of CerS5 function reduces the development of aortic valve stenosis in mice with high fat diet, by decreasing immune cell infiltration and calcification. Interestingly, in the groups with normal chow, loss of CerS5 function had no effect. In addition, high-fat diet alone had no negative effect in our mouse model. Based on our results it can be assumed that upon high fat diet CerS5 mediates for pro-inflammatory effects in the aortic valve, which are absent on normal diet. Funding Acknowledgement Type of funding sources: Foundation. Main funding source(s): Ernst & Berta Grimmke Foundation (13/19)

Role of endothelial CXCR4 in the development of aortic valve stenosis

BackgroundCXCL12/CXCR4 signaling is essential in cardiac development and repair, however, its contribution to aortic valve stenosis (AVS) remains unclear. In this study, we tested the role of endothelial CXCR4 on the development of AVS.Materials and methodsWe generated CXCR4 endothelial cell-specific knockout mice (EC CXCR4 KO) by crossing CXCR4fl/fl mice with Tie2-Cre mice to study the role of endothelial cell CXCR4 in AVS. CXCR4fl/fl mice were used as controls. Echocardiography was used to assess the aortic valve and cardiac function. Heart samples containing the aortic valve were stained using Alizarin Red for detection of calcification. Masson’s trichrome staining was used for the detection of fibrosis. The apex of the heart samples was stained with wheat germ agglutinin (WGA) to visualize ventricular hypertrophy.ResultsCompared with the control group, the deletion of CXCR4 in endothelial cells led to significantly increased aortic valve peak velocity and aortic valve peak pressure gradient, with decreased aortic valve area and ejection fraction. EC CXCR4 KO mice also developed cardiac hypertrophy as evidenced by increased diastolic and systolic left ventricle posterior wall thickness (LVPW), cardiac myocyte size, and heart weight (HW) to body weight (BW) ratio. Our data also confirmed increased microcalcifications, interstitial fibrosis, and thickened valvular leaflets of the EC CXCR4 KO mice.ConclusionThe data collected throughout this study suggest the deletion of CXCR4 in endothelial cells is linked to the development of aortic valve stenosis and left ventricular hypertrophy. The statistically significant parameters measured indicate that endothelial cell CXCR4 plays an important role in aortic valve development and function. We have compiled compelling evidence that EC CXCR4 KO mice can be used as a novel model for AVS.

Development of aortic valve stenosis in myeloperoxidase antineutrophil cytoplasmic antibody-associated vasculitis with renal involvement.

IntroductionDegenerative aortic valve stenosis (AS) is a chronic progressive disease that resembles atherosclerosis development. Antineutrophil cytoplasmic antibody-associated vasculitis (AAV) is reportedly associated with accelerated atherosclerosis. This study aimed to examine the development of AS in patients with myeloperoxidase-AAV (MPO-AAV) with renal involvement at more than 1 year after the onset of vasculitis.MethodsWe performed a retrospective review of clinical records of MPO-AAV patients with renal involvement without AS at the onset of vasculitis who were treated in three hospitals and three dialysis clinics.ResultsThe study included 97 MPO-AAV patients with renal involvement and 230 control patients with chronic kidney disease (CKD). Among them, 64 patients had AS. The prevalence rates of AS were 28.9% and 15.7% in MPO-AAV and control patients, respectively (p = 0.006). The multivariable logistic regression analysis showed that MPO-AAV, dialysis dependence, and hypertension were independently associated factors for AS. In MPO-AAV patients, systolic blood pressure was positively significantly associated with AS, whereas glucocorticoid dose of induction therapy was negatively significantly associated. The use of cyclophosphamide tended to be negatively associated with AS. The survival rate was significantly lower for patients with AS than for those without AS.ConclusionsThe AS prevalence rate was significantly higher in MPO-AAV patients at more than 1 year after the onset of vasculitis than in control CKD patients. Therefore, regular monitoring of echocardiography during MPO-AAV treatment is suggested.

Toll-like-receptor-3 function is critical for aortic valve stenosis development in mice

Abstract Background Aortic valve stenosis (AS) is the most common valve diseases in the western world. After having been considered a passive degenerative process, which develops as an inevitable consequence of age-related valvular degeneration, basic research of the last two decades has led to a paradigm shift. It is now believed that AS pathophysiology is driven by distinct molecular and cellular mechanisms which include inflammatory pathways. In recent years, Toll-like-receptor-3 (TLR3) has emerged as a major regulator of vascular inflammation. TLR3 is a lysosomal pattern recognition receptor that recognizes single and double stranded RNA. Its activation leads to expression of pro-inflammatory cytokines via NFkb activation. The role of TLR3 in the development of AS has never been investigated. Methods Severe AS was induced in Wildtype-, ApoE- and TLR3/ApoE−/− mice. For this, a coronary springwire was used to induce an endothelial injury under echocardiographic guidance. Stenosis development was confirmed via ultrasound examinations. To inhibit TLR-3 activation, TLR3/RNA- Complex inhibitor C4a was injected every 48h after wire injury in WT mice. Valves were explanted and stained with hematoxylin/eosin (valve thickening) or anti-68 (macrophage infiltration). Valves from patients who received aortic valve replacement due to AS or aortic regurgitation (AR) were collected and mRNA levels of TLR3 and MyD88 were measured with use of quantitative-PCR. Results To evaluate weather TLR3 effects AS development in mice, we subjected TLR3/ApoE double- and ApoE knockout mice to our model of wire-induced AS. Surprisingly, TLR3 deficient mice failed to develop AS after wire injury. Peak velocity measurements showed no increase and histological analysis showed lower aortic valve area and macrophage infiltration compared to control mice. In order to pharmacological inhibit TLR3, WT mice were treated with C4a after wire injury. Compared to PBS control, C4a mice also did not develop AS upon wire injury. Trans-aortic valve peak velocity levels were significantly lower in C4a mice. Histological analysis underlined these results and showed thinner aortic valves and decreased macrophage infiltration in C4a mice comparted to control animals. To confirm our hypothesis, the expression of TLR3 and its downstream effector MyD88 were measured in human aortic valve specimens. qPCR analysis revealed decreased TLR3 and MyD88 expression in patients with AS compared to patients with AR. Conclusion In the presented study, we present first data that theTLR3 has a crucial role in the development of AS in mice. The exact downstream effects after TLR3 activation in AS need to be further investigated. Funding Acknowledgement Type of funding source: Public grant(s) – National budget only. Main funding source(s): Deutsche Forschungsgemeinschaft (DFG, German Research Foundation)

Dissolving cholesterol crystals reduces aortic valve stenosis development in mice

Abstract Background Aortic valve stenosis (AS) is the most common valve disease worldwide and is associated with a very high morbidity and mortality. Until today, aortic valve replacement is the only therapeutic option available. Analysis of explanted human aortic valves has shown that atherosclerosis-like lesions, that contain cholesterol crystals (CC), are present in stenotic aortic valve cusps. It has been demonstrated that CCs can activate the NLRP3 inflammasome and hereby trigger a complex, IL-1b driven, inflammatory response. 2-hydroxypropyl-β-cyclodextrin (CD) is a cyclic oligosaccharide that can increase the solubility of CCs, which results in a reduction of CC-load and therefore could inhibit the pro-inflammatory immune response. Methods Severe AS was induced in 10 weeks old C57BL/6-J (WT) and Apolipoprotein-E-deficient (ApoE) mice. Acoronary springwire was used to induce an endothelial injury under echocardiographic guidance. AS development was confirmed via ultrasound examinations. ApoE mice were fed a cholesterol-rich western diet and concomitantly received daily injections of 2g/kg/d CD via subcutaneous injection. CCs were visualized with laser reflection confocal microscopy. Serum cholesterol analysis were performed via mass GC-MS-SIM. Results In order to evaluate whether hyperlipidemia aggravates AS development, WT and ApoE mice were fed a cholesterol-rich diet and subjected to our model of wire-induced AS. Trans-aortic valve peak velocity levels of ApoE mice were significantly increased six weeks after injury compared to WT mice. Histological analysis of these mice showed large CC-deposits in the aortic valves of ApoE mice. Next, CC solubility was increased in a group of ApoE mice, control mice only received PBS injections. Interestingly, mice treated with CD displayed a significantly reduced peak blood velocity over the aortic valve compared to PBS mice. Left ventricular ejection fraction remained unchanged. Serum cholesterol analysis was performed to analyze the effect of CD on cholesterol metabolism. 27-hydroxycholesterol, an endogenous oxysterol of cholesterol metabolism, which reduces the potential for the conversion of free cholesterol into crystals was significantly increased in CD treated mice. The levels of cholesterol precursors were unchanged, indicating that CD doesn't influence de-novo synthesis of cholesterol. Intestinal absorption of cholesterol was also not affected by CD, as assessed by quantification of phytosterols in the serum of CD and PBS treated mice. Conclusion These results underline the importance of hyperlipidemia in the pathogenesis of AS. Particularly CCs seem to act as an important inflammatory trigger in the development of AS. Increasing the solubility of cholesterol through CD reduces AS development in mice and could, as it is already considered safe in human, act as a possible therapeutic option. Funding Acknowledgement Type of funding source: Public grant(s) – National budget only. Main funding source(s): DFG, German Research Foundation

Predictors of In-Hospital Mortality after Transcatheter Aortic Valve Implantation

The development of aortic valve stenosis is strongly associated with older adults. Patients who undergo transcatheter aortic valve implantation (TAVI) for severe aortic stenosis frequently have heart failure (HF). We investigated the predictors of mortality after TAVI according to the presence of HF, and specifically HF with preserved ejection fraction (HFpEF) versus HF with reduced ejection fraction (HFrEF). Patients were identified from the Nationwide Inpatient Sample registry from January 2011 to September 2015 using the ICD-9 codes. Patients with HF who underwent TAVI were classified according to whether they were diagnosed with HFrEF or HFpEF. The principal outcome of interest was in-hospital mortality. Multivariable analysis was used to adjust for potential baseline confounders. Among 11,609 patients undergoing TAVI, 6,368 (54.9%) had baseline HF, including 4,290 (67.4%) with HFpEF and 2,078 (32.6%) with HFrEF. In TAVI patients with HF, in-hospital mortality was also not significantly different in those with HFrEF compared with HFpEF (3.66% vs 3.17%, respectively; adjusted odds ratio 1.14, 95% confidence interval 0.84 to 1.53; p = 0.38). Polyvalvular heart disease was an additional independent predictor of in-hospital mortality in HFrEF, whereas age, liver disease, and the absence of depression and anemia were additional independent predictors of mortality in HFpEF. In conclusion, baseline HF in patients undergoing TAVI is prevalent and is more commonly due to HFpEF than HFrEF. Mortality is similar in those with HFrEF and HFpEF. Knowledge of the specific predictors of mortality after TAVI in HF patients may be useful for patient selection and prognostic guidance.

P5988Non-classical Ly6C-low monocytes contribute to aortic valve stenosis development in mice

Abstract Introduction Aortic valve stenosis (AS) is one of the most common valvular diseases in the western world. Once patients with AS develop symptoms mortality increases up to 50% over two years. For many years AS was believed to be a passive degenerative process. Recent findings suggest a more complex pathomechanism with a strict molecular and cellular regulation involving local inflammation and invasion of immune cells. Specifically, pro-inflammatory macrophages have been shown to play an important role in disease progression. On the other hand, monocyte counts in the peripheral blood of patients with severe AS are significantly decreased and there is an inverse correlation between valve orifice area and circulating monocyte count. In order to elucidate the exact function of pro-inflammatory classical (Ly6C-high) and non-classical (Ly6C-low) monocytes in disease initiation processes, we conducted a series of experiments in a model of murine AS. Methods In this study 10–12 weeks old male C57BL6/J or CX3CR1-deficient mice were investigated. For AS induction, a coronary springwire was introduced into the left ventricle, pushed and rotated over the aortic valve under echocardiographic guidance. In sham operated mice the wire was only inserted into the left carotid artery without manipulation of the aortic valve. Development of AS was confirmed via weekly ultrasound examinations. Immune cells in the aortic valve were quantified using flow cytometry and immunofluorescence microscopy. Results Ultrasound analysis after two weeks confirmed the development of AS in the injured wildtype mice. Transaortic peak velocity levels were significantly increased compared to sham operated mice. Flow cytometry of explanted aortic valves showed a strong cellular immunoreaction in the stenotic valves. The amount of anti-inflammatory Ly6C-low monocytes was significantly increased compared to sham-mice, whereas the number of pro-inflammatory Ly6C-high monocytes remained stable. Interestingly CD-4 positive T-cells were augmented in stenotic aortic valves. Immunofluorescence confirmed Ly6C-low monocytes infiltration in the valve, in close proximity to the endothelial cells on the ventricular and the aortic side. The expression of recruitment and adhesion markers CD11b and CX3CR1 were significantly increased on the surface of the Ly6C-low monocytes of AS mice. To investigate the role of Ly6C-low monocytes in AS development, CX3CR1 deficient mice, which are not able to recruit non-classical monocytes via CX3CR1, were subjected to aortic valve wire injury. After two weeks, peak velocity levels in CX3CR1−/− mice remained nearly unchanged and were significantly decreased compared to wildtype mice. Conclusion Our data suggest that non-classical Ly6Clow monocytes play a crucial role in AS development in mice. Therefore, they may be targets for future therapeutic interventions. Acknowledgement/Funding S.T.N. was funded by Else-Kröner-Fresenius-Foundation of the Medical Faculty of the University of Bonn

Dietary patterns, food groups, and incidence of aortic valve stenosis: A prospective cohort study

BackgroundThe role of diet in the development of aortic valve stenosis (AVS) is unknown. We therefore examined the associations of two dietary patterns, including a modified Dietary Approaches to Stop Hypertension (mDASH) diet and a modified Mediterranean (mMED) diet, and the food items included in these dietary patterns with incidence of aortic valve stenosis (AVS) in a population-based cohort study. MethodsThe study cohort comprised 74,401 Swedish adults (54% men) who were free of cardiovascular disease at the time of completion of a baseline questionnaire about habitual diet and other risk factors for chronic diseases. Participants were followed-up through linkage with nationwide registers on hospitalization and causes of death. ResultsDuring 1,132,617 person-years (mean 15.2 years) of follow-up, 1338 incident AVS cases (801 in men and 537 in women) were ascertained. We found no significant associations of the mDASH and mMED dietary patterns or the food groups and beverages included in these diets (i.e., fruit, vegetables, legumes and nuts, whole grains, fish, low-fat dairy foods, full-fat dairy foods, red and processed meat, and sweetened beverages) with risk of AVS. The hazard ratios (95% confidence interval) of AVS per one standard deviation increase in the mDASH and mMED diet scores were respectively 1.02 (0.96–1.07) and 1.00 (0.95–1.06). ConclusionThis study found no evidence that diet plays a role in the development of AVS.

P5128Role of CLEC4E expression in development of aortic valve stenosis

P5128Role of CLEC4E expression in development of aortic valve stenosis

Asunaprevir/daclatasvir and sofosbuvir/ledipasvir for recurrent hepatitis C following living donor liver transplantation.

This study aimed to clarify the efficacy and safety of interferon-free therapy using asunaprevir and daclatasvir, or sofosbuvir and ledipasvir for post living donor liver transplantation (LDLT) recipients with hepatitis C virus (HCV). A retrospective cohort study of LDLT recipients with HCV genotype 1b treated with asunaprevir (100mg twice daily) and daclatasvir (60mg once daily), or sofosbuvir (400mg/day) and ledipasvir (90mg/day) was carried out. Ten patients without mutations in the area of L31 and Y93 completed the treatment with asunaprevir and daclatasvir. Five of them had end-stage chronic kidney disease, including three hemodialysis patients. Of the 10 patients, nine completed the protocol of 24weeks; one stopped the treatment due to the development of aortic valve stenosis. All nine patients who completed the 24-week treatment protocol achieved end of treatment response. Nineteen patients received treatment with sofosbuvir and ledipasvir. Of the 19 patients, 18 completed the protocol of 12weeks; one stopped treatment due to severe interstitial pneumonia. All 18 patients who completed the 12-week treatment protocol achieved end of treatment response. All patients in both treatment groups who completed the regimen and reached 3months after the end of treatment achieved sustained virological response at 12weeks after treatment. Liver functions were significantly improved at the end of treatment, and no adverse events were observed. Interferon-free therapy using asunaprevir and daclatasvir, or sofosbuvir and ledipasvir, is highly effective for post-LDLT recipients with HCV genotype 1b.

RNA expression profile of calcified bicuspid, tricuspid, and normal human aortic valves by RNA sequencing.

The molecular mechanisms leading to premature development of aortic valve stenosis (AS) in individuals with a bicuspid aortic valve are unknown. The objective of this study was to identify genes differentially expressed between calcified bicuspid aortic valves (BAVc) and tricuspid valves with (TAVc) and without (TAVn) AS using RNA sequencing (RNA-Seq). We collected 10 human BAVc and nine TAVc from men who underwent primary aortic valve replacement. Eight TAVn were obtained from men who underwent heart transplantation. mRNA levels were measured by RNA-Seq and compared between valve groups. Two genes were upregulated, and none were downregulated in BAVc compared with TAVc, suggesting a similar gene expression response to AS in individuals with bicuspid and tricuspid valves. There were 462 genes upregulated and 282 downregulated in BAVc compared with TAVn. In TAVc compared with TAVn, 329 genes were up- and 170 were downregulated. A total of 273 upregulated and 147 downregulated genes were concordantly altered between BAVc vs. TAVn and TAVc vs. TAVn, which represent 56 and 84% of significant genes in the first and second comparisons, respectively. This indicates that extra genes and pathways were altered in BAVc. Shared pathways between calcified (BAVc and TAVc) and normal (TAVn) aortic valves were also more extensively altered in BAVc. The top pathway enriched for genes differentially expressed in calcified compared with normal valves was fibrosis, which support the remodeling process as a therapeutic target. These findings are relevant to understand the molecular basis of AS in patients with bicuspid and tricuspid valves.

Identification of Fibrotic Thickening as Early Marker of Aortic Valve Stenosis Using X-Ray Micro Computed Tomography and Optical Coherence Tomography

Objective: Calcific aortic valve stenosis is the most common heart valve disease in North America and Europe and represents the late stage of a perennial progressive disease. Since pharmacological therapies have not been effective so far, the only available treatment options are surgical or transcatheter valve replacement. Premature pathological changes are characterized by a mild thickening of the valve cusps without overt hemodynamic changes. As currently available visualization techniques in clinical practice fail to detect early events of fibrotic aortic valve thickening there is a mandatory demand in the generation of novel non-invasive diagnostic tools that allow visualization and quantification of early pathological changes during development of aortic valve stenosis.

Involvement of Immune Cell Network in Aortic Valve Stenosis: Communication between Valvular Interstitial Cells and Immune Cells.

Aortic valve stenosis is a heart disease prevalent in the elderly characterized by valvular calcification, fibrosis, and inflammation, but its exact pathogenesis remains unclear. Previously, aortic valve stenosis was thought to be caused by chronic passive and degenerative changes associated with aging. However, recent studies have demonstrated that atherosclerotic processes and inflammation can induce valvular calcification and bone deposition, leading to valvular stenosis. In particular, the most abundant cell type in cardiac valves, valvular interstitial cells, can differentiate into myofibroblasts and osteoblast-like cells, leading to valvular calcification and stenosis. Differentiation of valvular interstitial cells can be trigged by inflammatory stimuli from several immune cell types, including macrophages, dendritic cells, T cells, B cells, and mast cells. This review indicates that crosstalk between immune cells and valvular interstitial cells plays an important role in the development of aortic valve stenosis.