Aortic Valve Fibrosis Research Articles

Novel Biomarkers in Evaluating Cardiac Function in Patients on Hemodialysis-A Pilot Prospective Observational Cohort Study.

Chronic kidney disease patients treated by hemodialysis present a high cardiovascular morbidity and mortality. There is an imperative need for novel biomarkers for identifying these patients and to offer possible therapeutically interventions. We performed a prospective observational cohort study on 77 patients in the period of October 2021-October 2023. We measured serum plasma levels of interleukin 1-beta, galectin 3, human suppression of tumorigenicity factor 2, bone morphogenetic protein 2 and fibroblastic growth factor 23 at the inclusion site. We evaluated the correlations of these biomarkers with cardiac function and structure evaluated by echocardiography. The mean age was 61.02 (±11.81) years, with 45 (56.2%) males and with a dialysis vintage of 4.95 (2.4-7.8) years. Median ejection fraction was 51 (43-54%), and more than two-thirds of the patients presented valvular calcifications. Overall mortality was 22%. Interleukin 1-beta was correlated positively with ejection fraction and global longitudinal strain and negatively with left atrium diameter and left ventricle telesystolic diameter. Galectin 3 values were negatively correlated with aortic valve fibrosis and mitral valve calcifications, and human suppression tumorigenicity factor 2 was negatively correlated with mitral valve calcifications. Some of these novel biomarkers could be used to better assess cardiovascular disease in patients on maintenance hemodialysis.

Molecular Interaction of Soluble Klotho with FGF23 in the Pathobiology of Aortic Valve Lesions Induced by Chronic Kidney Disease.

Chronic kidney disease (CKD) is linked to greater prevalence and rapid progression of calcific aortic valve disease (CAVD) characterized by valvular leaflet fibrosis and calcification. Fibroblast growth factor 23 (FGF23) level is elevated, and anti-aging protein Klotho is reduced in CKD patients. However, the roles of FGF23 and Klotho in the mechanism of aortic valve fibrosis and calcification remain unclear. We hypothesized that FGF23 mediates CKD-induced CAVD by enhancing aortic valve interstitial cell (AVIC) fibrosis and calcification, while soluble Klotho inhibits FGF23 effect. Methods and Results: In an old mouse model of CKD, kidney damages were accompanied by aortic valve thickening and calcification. FGF23 levels in plasma and aortic valve were increased, while Klotho levels were decreased. Recombinant FGF23 elevated the inflammatory, fibrogenic, and osteogenic activities in AVICs. Neutralizing antibody or shRNA targeting FGF23 suppressed the pathobiological activities in AVICs from valves affected by CAVD. FGF23 exerts its effects on AVICs via FGF receptor (FGFR)/Yes-associated protein (YAP) signaling, and inhibition of FGFR/YAP reduced FGF23's potency in AVICs. Recombinant Klotho downregulated the pathobiological activities in AVICs exposed to FGF23. Incubation of FGF23 with Klotho formed complexes and decreased FGF23's potency. Further, treatment of CKD mice with recombinant Klotho attenuated aortic valve lesions. Conclusion: This study demonstrates that CKD induces FGF23 accumulation, Klotho insufficiency and aortic valve lesions in old mice. FGF23 upregulates the inflammatory, fibrogenic and osteogenic activities in AVICs via the FGFR/YAP signaling pathway. Soluble Klotho suppresses FGF23 effect through molecular interaction and is capable of mitigating CKD-induced CAVD.

The gut microbe-derived metabolite trimethylamine-N-oxide induces aortic valve fibrosis via PERK/ATF-4 and IRE-1α/XBP-1s signaling in vitro and in vivo

Background and aimsThe gut microbe-derived metabolite trimethylamine-N-oxide (TMAO) has been implicated in the development of cardiovascular fibrosis. Endoplasmic reticulum (ER) stress occurs after the dysfunction of ER and its structure. The three signals PERK/ATF-4, IRE-1α/XBP-1s and ATF6 are activated upon ER stress. Recent reports have suggested that the activation of PERK/ATF-4 and IRE-1α/XBP-1s signaling contributes to cardiovascular fibrosis. However, whether TMAO mediates aortic valve fibrosis by activating PERK/ATF-4 and IRE-1α/XBP-1s signaling remains unclear. MethodsHuman aortic valve interstitial cells (AVICs) were isolated from aortic valve leaflets. PERK IRE-1α, ATF-4, XBP-1s and CHOP expression, and production of collagen Ⅰ and TGF-β1 were analyzed following treatment with TMAO. The role of PERK/ATF-4 and IRE-1α/XBP-1s signaling pathways in TMAO-induced fibrotic formation was determined using inhibitors and small interfering RNA. ResultsDiseased valves produced greater levels of ATF-4, XBP-1, collagen Ⅰ and TGF-β1. Interestingly, diseased cells exhibited augmented PERK/ATF-4 and IRE-1α/XBP-1s activation after TMAO stimulation. Inhibition and silencing of PERK/ATF-4 and IRE-1α/XBP-1s each resulted in enhanced suppression of TMAO-induced fibrogenic activity in diseased cells. Mice treated with dietary choline supplementation had substantially increased TMAO levels and aortic valve fibrosis, which were reduced by 3,3-dimethyl-1-butanol (DMB, an inhibitor of trimethylamine formation) treatment. Moreover, a high-choline and high-fat diet remodeled the gut microbiota in mice. ConclusionsTMAO promoted aortic valve fibrosis through activation of PERK/ATF-4 and IRE-1α/XBP-1s signaling pathways in vitro and in vivo. Modulation of diet, gut microbiota, TMAO, PERK/ATF-4 and IRE1-α/XBP-1s may be a promising approach to prevent aortic valve fibrosis.

Quantification of aortic valve fibrosis and calcification by computed tomography angiography: a prospective head-to-head comparison with histology

Abstract Background Calcific aortic stenosis (AS) is characterized by leaflet degeneration involving fibrocalcific alterations which limit leaflet mobility and eventually lead to obstruction of flow across the aortic valve. While cardiac computed tomography (CT) has been routinely used for quantification of aortic valve calcium in individuals in whom echocardiography is inconclusive, recent studies on quantification of aortic valve fibrosis are lacking histological validation. [1,2] Purpose We, thus, aimed to validate a non-invasive CTA-derived quantitative characterization of aortic valve tissue against histologic examination of excised aortic valve leaflets. Methods In this prospective study, patients underwent CTA within a month before surgical aortic valve replacement for aortic stenosis. Tomographic valve tissue components were identified by Gaussian mixture modeling applied to CTA, by automatically fitting Gaussian functions to the Hounsfield Unit (HU) histograms for blood pool, non-calcific, and calcific aortic valve tissue. Tissue composition, expressed as % [(tissue component volume / total tissue volume) × 100%], was automatically calculated. For histologic evaluation, explanted valve leaflets were stained with Movat's Pentachrome. For every leaflet, three non-consecutive 5-µm sections were obtained. Further, an automatic algorithm detecting pixel intensities was applied for color differentiation and quantification of tissue components (Figure 1). Separate measurements from all the sections of the single valve were finally averaged and compared with CTA-derived calculations. Results A total of nineteen patients (63% men, 67±8 years old) undergoing isolated surgical aortic valve replacement for severe aortic stenosis with preoperative CTA were evaluated. The mean proportion of non-calcific aortic valve tissue was 68±16% in CTA and 75±3% on Movat’s Pentachrome staining (p=0.004, paired samples comparison). There was a strong correlation between the two modalities (r=0.856, p<0.001; Figure 2A). Intermodal repeatability between CTA and histology for non-calcific tissue quantification was excellent with an interclass correlation coefficient of 0.855 (95% CI 0.663 – 0.942, p<0.001), coefficient of repeatability of 16.8% and bias of -6.7% (p=0.234, Figure 2B). Conclusions CTA-derived characterization of aortic valve tissue provides an accurate quantification of non-calcific tissue as compared with gold-standard histologic examinations of explanted stenotic valves.Figure 1Figure 2

Abstract 11668: Transcriptomic Analysis Reveals Sex Differences in Gene Expression Profiling of Stenotic Aortic Valves

Introduction: In aortic stenosis (AS), women present less aortic valve calcification and more aortic valve fibrosis than men for the same hemodynamic severity. However, the specific mediators that drive the fibro-calcific differences between men and women remain unclear. We aim to assess the transcriptome of stenotic aortic valves explanted during aortic valve replacement, according to patient’s sex. Methods: Transcriptomic profile was obtained from 240 explanted human aortic valves. Among these 240 patients (120 women and 120 men), 62 women were matched with 62 men for age (within 2 years), body mass index (within 2 kg/m 2 ), arterial pressure (within 10/5 mmHg), diabetes (exact), hypertension (exact) and AS severity (Table 1). Genes were classified in 6 key processes of AS development: oxidative stress, inflammation, lipid metabolism, fibrosis, apoptosis and calcification following a literature review. Results: One hundred and ninety (190) genes were differently regulated between men and women: 132 on autosomes and 58 on sexual chromosomes. Among these genes, 106 were over-expressed and 84 were under-expressed in women compared to men (Figure 1). Different genes involved in processes of inflammation, lipid metabolism and calcification were up-regulated both in women and men (women: NET1 , KIF1A, CES1, RCN2; men: FERMT3, APOD, CPAMD8, STC2 ). Genes involved in apoptosis ( SFRP4 ) and fibrosis processes ( TGFβ2 , FRAS1 ) were overexpressed in women. Conclusions: This study provides evidence that sex may influence aortic valve gene expression through different mechanisms in females and males, favoring pro-fibrotic and pro-apoptotic processes in women.

TRPM4 Participates in Irradiation-Induced Aortic Valve Remodeling in Mice.

Simple SummaryDespite its benefit in cancer treatment, thoracic irradiation can induce aortic valve stenosis with fibrosis and calcification. The TRPM4 cation channel is known to participate in cellular remodeling including the transition of cardiac fibroblasts to myofibroblasts, similar to that observed during aortic valve stenosis. This study evaluates if TRPM4 is involved in irradiation-induced aortic valve damage. The aortic valve of mice was targeted by irradiation. Cardiac echography 5 months after treatment revealed an increase in aortic jet velocity, indicating stenosis. This was not observed in non-treated animals. Histological analysis revealed an increase in valvular cusp surface associated with fibrosis which was not observed in non-treated animals. The experiments were reproduced on mice after Trpm4 gene disruption. In these animals, irradiation did not induce valvular remodeling. It indicates that TRPM4 influences irradiation-induced aortic valve damage and thus could be a target to prevent such side effects of irradiation.Thoracic radiotherapy can lead to cardiac remodeling including valvular stenosis due to fibrosis and calcification. The monovalent non-selective cation channel TRPM4 is known to be involved in calcium handling and to participate in fibroblast transition to myofibroblasts, a phenomenon observed during aortic valve stenosis. The goal of this study was to evaluate if TRPM4 is involved in irradiation-induced aortic valve damage. Four-month-old Trpm4+/+ and Trpm4−/− mice received 10 Gy irradiation at the aortic valve. Cardiac parameters were evaluated by echography until 5 months post-irradiation, then hearts were collected for morphological and histological assessments. At the onset of the protocol, Trpm4+/+ and Trpm4−/− mice exhibited similar maximal aortic valve jet velocity and mean pressure gradient. Five months after irradiation, Trpm4+/+ mice exhibited a significant increase in those parameters, compared to the untreated animals while no variation was detected in Trpm4−/− mice. Morphological analysis revealed that irradiated Trpm4+/+ mice exhibited a 53% significant increase in the aortic valve cusp surface while no significant variation was observed in Trpm4−/− animals. Collagen staining revealed aortic valve fibrosis in irradiated Trpm4+/+ mice but not in irradiated Trpm4−/− animals. It indicates that TRPM4 influences irradiation-induced valvular remodeling.

Sex-Specific Cell Types and Molecular Pathways Indicate Fibro-Calcific Aortic Valve Stenosis.

BackgroundAortic stenosis (AS) is the most common valve disorder characterized by fibro-calcific remodeling of leaflets. Recent evidence indicated that there is a sex-related difference in AS development and progression. Fibrotic remodeling is peculiar in women’s aortic valves, while men’s leaflets are more calcified. Our study aimed to assess aortic valve fibrosis (AVF) in a severe AS cohort using non-invasive diagnostic tools and determine whether sex-specific pathological pathways and cell types are associated with severe AS.Materials and MethodsWe have included 28 men and 28 women matched for age with severe AS who underwent echocardiography and cardiac contrast-enhanced computed tomography (CT) before intervention. The calcium and fibrosis volumes were assessed and quantified using the ImageJ thresholding method, indexed calcium and fibrosis volume were calculated by dividing the volume by the aortic annular area. For a deeper understanding of molecular mechanisms characterizing AS disorder, differentially expressed genes and functional inferences between women and men’s aortic valves were carried out on a publicly available microarray-based gene expression dataset (GSE102249). Cell types enrichment analysis in stenotic aortic valve tissues was used to reconstruct the sex-specific cellular composition of stenotic aortic valves.ResultsIn agreement with the literature, our CT quantifications showed that women had significantly lower aortic valve calcium content compared to men, while fibrotic tissue composition was significantly higher in women than men. The expression profiles of human stenotic aortic valves confirm sex-dependent processes. Pro-fibrotic processes were prevalent in women, while pro-inflammatory ones, linked to the immune response system, were enhanced in men. Cell-type enrichment analysis showed that mesenchymal cells were over-represented in AS valves of women, whereas signatures for monocytes, macrophages, T and B cells were enriched men ones.ConclusionsOur data provide the basis that the fibro-calcific process of the aortic valve is sex-specific, both at gene expression and cell type level. The quantification of aortic valve fibrosis by CT could make it possible to perform population-based studies and non-invasive assessment of novel therapies to reduce or halt sex-related calcific aortic valve stenosis (CAVS) progression, acting in an optimal window of opportunity early in the course of the disease.

The Gut Microbe-Derived Metabolite Trimethylamine-N-Oxide Induces Aortic Valve Fibrosis Via PERK/ATF-4 and IRE-1α/XBP-1s Signaling in Vitro and in Vivo

The Gut Microbe-Derived Metabolite Trimethylamine-N-Oxide Induces Aortic Valve Fibrosis Via PERK/ATF-4 and IRE-1α/XBP-1s Signaling in Vitro and in Vivo

Sex difference in aortic valve fibrosis assessed by contrast-enhanced computed tomography in severe aortic stenosis

Abstract Background Aortic stenosis (AS) is characterized by fibro-calcific remodeling of aortic valve leaflets. Progressive aortic valve calcification (AVC) occurs in both sexes and cardiac computed tomography (CT) is recognized as a high-quality technique for AVC evaluation. To date, sex-specific CT thresholds of AVC have been implemented in clinical practice since it is now recognized that women have less AVC burden than men. In addition, recent evidences indicate that women have more fibrotic remodeling of aortic valve leaflet compared to men. Purpose Aortic valve fibrosis (AVF) being a significant contributor to valve gradient, we sought to evaluate the difference in AVF burden between men and women with severe AS using contrast-enhanced CT. Methods We included 56 patients matched for age and sex with severe AS. All patients underwent Doppler echocardiography and cardiac CT before intervention. Contrast attenuation values (Hounsfield Units, HU) and contrast-to-noise ratio were measured at the level of the ascending aorta. Total AVF was assessed based on HU ranging between 30 and 350, adjusting the upper threshold by increments of 25 HU in either direction until blood pool was not highlighted. Indexed contrast-enhanced CT calcium volume (iAVC) and fibrosis volume (iAVF) were calculated dividing the volumes by the aortic annular area. Fibro-calcific ratio was calculate dividing iAVF by iAVC volumes. Results There was no difference between men and women in major cardiovascular risk factors, valve phenotype (bicuspid vs. tricuspid), nor pharmacological treatment. Men had higher body surface area than women (1.89±0.14 vs. 1.67±0.17 m2, respectively; p<0.001), while women had lower aortic valve area than men (AVA; 0.74±0.2 vs. 0.91±0.2 cm2, respectively; p=0.007) but similar indexed AVA (0.44±0.15 vs. 0.48±0.12 cm2/m2, respectively; p=0.262). Women had significantly lower iAVC compared to men (36 [36–72] vs. 72 [67–123] mm3/cm2, respectively; p=0.03). However, iAVF was significantly higher in women compared to men (83 [78–123] vs. 63 [58–83] mm3/cm2, respectively; p=0.006). Finally, the fibro-calcific ratio, which indicates the predominance of valve fibrosis if >1.0, was significantly higher in women compared to men (2.57 [2.14–7.02] vs. 0.78 [0.84–2.02], respectively; p=0.003). Conclusions Our study highlights for the first time a sex difference in the fibrotic content of severe AS evaluated by contrast-enhanced CT. These findings might be valuable to promote further studies on the role of sex-specific tissue composition in AS progression and outcomes. Funding Acknowledgement Type of funding sources: Foundation. Main funding source(s): Fondazione Gigi e Pupa Ferrari ONLUS

Morphological Characteristics of Aortic Stenosis in Familial Hypercholesterolemia and Non-Familial Hypercholesterolemia in the Elderly

Background: Patients with familial hypercholesterolemia are known to have an extremely high risk of coronary artery disease owing to high levels of low-density lipoprotein-cholesterol since birth. In addition, aortic stenosis among patients with familial hypercholesterolemia has also been reported besides coronary disease. The aim of this study was to characterize the histopathological differences in excised aortic valves for aortic stenosis between patients with familial hypercholesterolemia and non-familial hypercholesterolemia. Subjects and Methods: Six familial patients (3 homozygous, 3 heterozygous familial hypercholesterolemia patients), and 18 non-familial hypercholesterolemia patients underwent pathological and immunohistochemical examinations for aortic valves macroscopically and microscopically at aortic valve replacement surgery for stenosis. Results: Our study revealed that calcification of aortic valves among homozygous hypercholesterolemia showed a much milder degree than those of non-familial patients. Moreover, the age at surgery for stenosis in the case of homozygotes was significantly less than that of heterozygous hypercholesterolemia and nonfamilial hypercholesterolemia patients. In addition, CD68-positive macrophages infiltrated the aorta side (fibrosa) in all familial hypercholesterolemia patients. However, the macrophage accumulation in the aortic valves of non-familial hypercholesterolemia patients was recognized in the middle layer (spongiosa) near calcification and left ventricular side (ventricularis) of the aortic valves. Conclusion: Lipid is one of the important factors for aortic valve fibrosis and stenosis in hypercholesterolemia. This study suggested that the non-familial atherosclerotic aortic stenosis in the elderly is qualitatively different from aortic valves in familial hypercholesterolemia, primarily owing to calcification resulting from age and long-term degeneration and inflammatory responses.

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

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.

Fibrotic aortic valve disease after radiotherapy: an immunohistochemical study in breast cancer and lymphoma patients.

Radiation-associated aortic valve (AV) stenosis is frequently seen as a late sequela after thoracic radiotherapy (RT). Although the clinical relationship between thoracic radiotherapy and valvular dysfunction has been established, the process leading to accelerated aortic valve stenosis remains unclear. The aim of this study was to determine whether increased inflammatory cell infiltration, fibrosis, and calcification is present in aortic valves after radiotherapy at the time of aortic valve replacement. Stenotic aortic valve specimens from 43 patients were obtained after surgical aortic valve replacement. A total 28 patients had previously undergone radiotherapy for breast cancer or malignant lymphoma. A total 15 patients were included as control. The valve leaflets were assessed by (immuno)histochemistry for inflammatory cell composition (CD3, CD20, CD68, and CD163) and extracellular matrix changes (collagen and calcification). Aortic valve cell density after radiotherapy for lymphoma was markedly decreased when compared with other groups. Irradiated aortic valve show similar (low) degrees of late T and B lymphocyte infiltration as control valves, whereas macrophage marker CD68 was decreased after radiotherapy for breast cancer. Collagen content was increased following radiotherapy. Aortic valves of patients with lymphoma contained significantly less calcified tissue when compared with the other groups. High-dose radiation at a young age (patients with lymphoma) results in cell loss and premature fibrotic aortic valve stenosis as opposed to the degenerative calcific stenosis observed in patients with breast cancer. Our findings suggest a possible dose-dependent effect of radiotherapy on aortic valve fibrosis. The active presence of inflammatory cells may be limited to the acute phase after radiotherapy.

Effect of Losartan and ACE Inhibition on Progression of Aortic Valve Fibrosis in ApoE-/- Mice

Objective: Calcific aortic valve stenosis (CAVS) is characterized by early fibrotic remodeling of extracellular matrix and hypertension is associated with faster progression of CAVS. Treatment with...

Abstract 159: Neurotrophin 3 Plays a Critical Role in TLR4-mediated Fibrogenic Response in Human Aortic Valve Interstitial Cells

Aortic stenosis is a chronic inflammatory condition, and valvular fibrosis and calcification are significant pathological changes in the progression of aortic stenosis. Aortic valve interstitial cell (AVIC) proliferation and over-expression of extracellular matrix (ECM) proteins promote valvular fibrosis. Although pro-inflammatory stimuli are the culprits of aortic valve fibrosis, the mechanism by which they induce aortic valve fibrogenic change remains incompletely understood. Our recent findings suggest that AVICs from diseased aortic valves express higher levels of neurotrophin 3 (NT3) protein and that NT3 is capable of up-regulating AVIC proliferation and ECM protein expression. In this study, we tested the hypothesis that pro-inflammatory stimulation up-regulates NT3 production to enhance the pro-fibrogenic activity in human AVICs. Methods and Results: Human AVICs isolated from normal valves were treated with Toll-like receptor 4 (TLR4) agonist lipopolysaccharide (LPS, 0.20 μg/ml) for 3 to 28 days in the presence or absence of a neutralizing antibody against NT3. LPS elevated BrdU incorporation, collagen III expression and collagen deposition. Neutralization of NT3 markedly reduced these pro-fibrogenic changes. Interestingly, LPS up-regulated NT3 levels in human AVICs in a TLR4-dependent fashion, and inhibition of either Akt or ERK1/2 attenuated the effect of LPS on NT3 expression. Recombinant NT3 induced human AVIC proliferation, collagen III expression and collagen deposition through the Trk receptors. Inhibition of the Trk receptors abrogated the pro-fibrogenic effect of LPS on AVICs. Conclusions: Stimulation of TLR4 in human AVICs elevates the pro-fibrogenic activity through up-regulating the production of neural growth factor NT3. The Akt and ERK1/2 pathways are involved in TLR4-mediated NT3 up-regulation, and the Trk receptors mediate the pro-fibrogenic effect of TLR4 stimulation in human AVICs. These findings reveal a molecular mechanism underlying pro-inflammatory elevation of AVIC pro-fibrogenic activity and indicate the therapeutic potential of antagonizing NT3 for suppression of aortic valve fibrosis in an inflammatory setting.

Secreted Klotho Attenuates Inflammation-Associated Aortic Valve Fibrosis in Senescence-Accelerated Mice P1.

Senescence-accelerated mice P1 (SAMP1) is an aging model characterized by shortened lifespan and early signs of senescence. Klotho is an aging-suppressor gene. The purpose of this study is to investigate whether in vivo expression of secreted klotho (Skl) gene attenuates aortic valve fibrosis in SAMP1 mice. SAMP1 mice and age-matched (AKR/J) control mice were used. SAMP1 mice developed obvious fibrosis in aortic valves, namely fibrotic aortic valve disease. Serum level of Skl was decreased drastically in SAMP1 mice. Expression of MCP-1 (monocyte chemoattractant protein 1), ICAM-1 (intercellular adhesion molecule 1), F4/80, and CD68 was increased in aortic valves of SAMP1 mice, indicating inflammation. An increase in expression of α-smooth muscle actin (myofibroblast marker), transforming growth factorβ-1, and scleraxis (a transcription factor of collagen synthesis) was also found in aortic valves of SAMP1 mice, suggesting that accelerated aging is associated with myofibroblast transition and collagen gene activation. We constructed adeno-associated virus 2 carrying mouse Skl cDNA for in vivo expression of Skl. Skl gene delivery effectively increased serum Skl of SAMP1 mice to the control level. Skl gene delivery inhibited inflammation and myofibroblastic transition in aortic valves and attenuated fibrotic aortic valve disease in SAMP1 mice. It is concluded that senescence-related fibrotic aortic valve disease in SAMP1 mice is associated with a decrease in serum klotho leading to inflammation, including macrophage infiltration and transforming growth factorβ-1/scleraxis-driven myofibroblast differentiation in aortic valves. Restoration of serum Skl levels by adeno-associated virus 2 carrying mouse Skl cDNA effectively suppresses inflammation and myofibroblastic transition and attenuates aortic valve fibrosis. Skl may be a potential therapeutic target for fibrotic aortic valve disease.

Prognostic Significance of Left Ventricular Fibrosis in Patients With Congenital Bicuspid Aortic Valve

This study sought to evaluate the prognostic value of left ventricular (LV) fibrosis assessed by late gadolinium enhancement (LGE) of the myocardium during cardiac magnetic resonance (CMR) imaging in patients with bicuspid aortic valve (BAV), which is associated with early aortic valve fibrosis and calcification. To what degree the LV myocardial wall is affected by fibrosis and its prognostic value is currently unknown. This is a retrospective, single-center study evaluating all adult patients with BAV who had CMR and followed from March 2002 to March 2016. CMR and transthoracic echocardiogram images were reviewed. Clinical data were abstracted from the electronic medical record. A total of 29 patients were included in the study, of which 11 (38%) had CMR studies that demonstrated the presence of LGE. Patients with LGE had significantly higher aortic valve mean gradients by echocardiography when compared with LGE-negative patients (30.3 ± 7.2 mm Hg vs 14.7 ± 3.6 mm Hg, p = 0.049). They were also more likely to have LV hypertrophy. Patients with LGE were 10 times more likely to need aortic valve replacement within 1 year of the CMR study than did patients without LGE (55% vs 5.5%, p = 0.0028). In conclusion, evaluation of LGE by CMR as a marker of LV myocardial fibrosis can have additional prognostic value when evaluating patients with aortic stenosis secondary to BAV.

Osteopontin Does not Inhibited Aortic Valve Fibrosis and Calcification in Three-Dimensional Ovine Aortic Valve Model

Osteopontin Does not Inhibited Aortic Valve Fibrosis and Calcification in Three-Dimensional Ovine Aortic Valve Model

Antifibrotic Medication Trail to Prevent Aortic Valve Fibrosis in an Murine Model

Antifibrotic Medication Trail to Prevent Aortic Valve Fibrosis in an Murine Model

Deficiency in the anti-aging gene Klotho promotes aortic valve fibrosis through AMPKα-mediated activation of RUNX2.

SummaryFibrotic aortic valve disease (FAVD) is an important cause of aortic stenosis, yet currently there is no effective treatment for FAVD due to its unknown etiology. The purpose of this study was to investigate whether deficiency in the anti‐aging Klotho gene (KL) promotes high‐fat‐diet‐induced FAVD and to explore the underlying molecular mechanism. Heterozygous Klotho‐deficient (KL +/−) mice and WT littermates were fed with a high‐fat diet (HFD) or normal diet for 13 weeks, followed by treatment with the AMPKα activator (AICAR) for an additional 2 weeks. A HFD caused a greater increase in collagen levels in the aortic valves of KL +/− mice than of WT mice, indicating that Klotho deficiency promotes HFD‐induced aortic valve fibrosis (AVF). AMPKα activity (pAMPKα) was decreased, while protein expression of collagen I and RUNX2 was increased in the aortic valves of KL +/− mice fed with a HFD. Treatment with AICAR markedly attenuated HFD‐induced AVF in KL +/− mice. AICAR not only abolished the downregulation of pAMPKα but also eliminated the upregulation of collagen I and RUNX2 in the aortic valves of KL +/− mice fed with HFD. In cultured porcine aortic valve interstitial cells, Klotho‐deficient serum plus cholesterol increased RUNX2 and collagen I protein expression, which were attenuated by activation of AMPKα by AICAR. Interestingly, silencing of RUNX2 abolished the stimulatory effect of Klotho deficiency on cholesterol‐induced upregulation of matrix proteins, including collagen I and osteocalcin. In conclusion, Klotho gene deficiency promotes HFD‐induced fibrosis in aortic valves, likely through the AMPKα–RUNX2 pathway.

Dyslipidemia in patients with arterial hypertension and extrasystoles

The significant incidence of hypertensive disease among the Ukrainian population makes the search for new methods of management and treatment of patients suffering from this pathology a matter of high priority. Our research is focused on study of changes of some biochemical parameters in patients suffering from hypertensive disease as well as patients suffering from hypertensive disease and coexistent extrasystoles. Arterial hypertension leads to different structural and functional changes in the cardiovascular system. In many patients these changes may result in rhythm disorders. 120 patients have been examined (42 men and 78 women) between the ages of 27 to 81 (average 59.8) suffering from hypertensive disease of the II stage as defined by the Ukrainian Association of Cardiologists and from extrasystoles (more than 30 episodes per hour of research) of different topography and 30 persons (13 men and 17 women) suffering from hypertensive disease of the II stage between the ages 30 to 76 (average 56.4) without rhythm disturbance). The first clinical group was formed by 54 (45%) patients suffering from repeated supraventricular extrasystoles (SE) (average 62 ± 2 SE per hour of research). The second clinical group was formed by 42 (35%) patients suffering from repeated ventricular arhythmia (VA) (average 37 ± 2 VA per hour of research). The third group was formed by 24 (20%) patients suffering from both repeated SE and VA (average 48 ± 3 SE and 32 ± 3 VA per hour of research). We conducted 24 hours’ monitoring of blood pressure and electrocardiography using the “Dia Card”-system (“Solvaig”, Ukraine) for all patients. This revealed that ventricle extrasystoles and combined extrasystoles in patients with essential hypertension, II stage are associated with more unfavourable changes in 24 hours’ profile of blood pressure. The paper analyses the cardiac arhythmia structure of heart rate variability in patients with arterial hypertension (AH) and extrasystoles. The findings confirmed the presence of desynchronization in the activity of the neurohnmoral system. Thus, different mechanisms of arhythmogenesis were revealed in patients with arterial hypertension. In the results, frequent ventricular and combined extrasystoles were associated with an unfavourable blood pressure profile during 24-hours monitoring as well as higher end-diastolic left ventricular volume, diastolic dysfunction, aortic valve fibrosis, aorta remodeling, endothelial dysfunction and more prominent lipid disorders. Supraventricular extrasystoles were associated with hypertriglyceridemia, left ventricular diastolic dysfunction and left atrium enlargement.