Differentiation Of Valve Interstitial Cells Research Articles

Morusin Alleviates Aortic Valve Calcification by Inhibiting Valve Interstitial Cell Senescence Through Ccnd1/Trim25/Nrf2 Axis.

The senescence of aortic valve interstitial cells (VICs) plays a critical role in the progression of calcific aortic valve disease (CAVD). However, the precise mechanisms underlying the senescence of VICs remain unclear, demanding the identification of a novel target to mitigate this process. Previous studies have highlighted the anti-aging potential of morusin. Thus, this study aimed to explore the therapeutic potential of morusin in CAVD. Cellular experiments reveal that morusin effectively suppresses cellular senescence and cause a shift toward osteogenic differentiation of VICs in vitro. Mechanistically, morusin activate the Nrf2-mediated antiaging signaling pathway by downregulating CCND1 expression and aiding Keap1 degradation through Trim 25. This activation lead to the upregulated expression of antioxidant genes, thus reducing reactive oxygen species production and thereby preventing VIC osteogenic differentiation. In vivo experiments in ApoE-/- mice on a high-fat Western diet demonstrate the positive effect of morusin in mitigating aortic valve calcification. These findings emphasize the antiaging properties of morusin and its potential as a therapeutic agent for CAVD.

Pro-osteogenic role of interleukin-22 in calcific aortic valve disease

Background and aimsAlthough calcific aortic valve disease (CAVD) is a common valvular disease among elderly populations and its incidence has markedly increased in recent decades, the pathogenesis of CAVD remains unclear. In this study, we explored the potential role of interleukin (IL)-22 and the underlying molecular mechanism in CAVD. Methods and ResultsOur results showed that IL-22 was upregulated in calcific aortic valves from CAVD patients, and its main sources were CD3+ T cells and CD68+ macrophages. Human aortic valve interstitial cells (VICs) expressed the IL-22–specific receptor IL-22R1, and IL-22R1 expression also was elevated in calcified valves. Treatment of cultured human VICs with recombinant human IL-22 resulted in markedly increased expression of osteogenic proteins Runt-related transcription factor 2 (RUNX2) and alkaline phosphatase (ALP), as well as increased matrix calcium deposition. Moreover, siRNA silencing of IL-22R1 blocked the pro-osteogenic effect of IL-22 in VICs. In IL-22–treated VICs, we also observed increased phosphorylation of JAK3 and STAT3 and nuclear translocation of STAT3. Pretreatment with a specific JAK3 inhibitor, WHIP-154, or siRNA knockout of STAT3 effectively mitigated the IL-22–induced osteoblastic trans-differentiation of human VICs. ConclusionsTogether, these data indicate that IL-22 promotes osteogenic differentiation of VICs by activating JAK3/STAT3 signaling. Based on our results demonstrating a pro-osteogenic role of IL-22 in human aortic valves, pharmacological inhibition of IL-22 signaling may represent a potential strategy for alleviating CAVD.

Valproic acid promotes osteogenic differentiation of valve interstitial cells

Valproic acid promotes osteogenic differentiation of valve interstitial cells

Activation of Piezo1 promotes osteogenic differentiation of aortic valve interstitial cell through YAP-dependent glutaminolysis.

Hemodynamic overload and dysregulation of cellular metabolism are involved in development of calcific aortic valve disease (CAVD). However, how mechanical stress relates to metabolic changes in CAVD remains unclear. Here, we show that Piezo1, a mechanosensitive ion channel, regulated glutaminase 1 (GLS1)-mediated glutaminolysis to promote osteogenic differentiation of valve interstitial cells (VICs). In vivo, two models of aortic valve stenosis were constructed by ascending aortic constriction (AAC) and direct wire injury (DWI). Inhibition of Piezo1 and GLS1 in these models respectively mitigated aortic valve lesion. In vitro, Piezo1 activation induced by Yoda1 and oscillatory stress triggered osteogenic responses in VICs, which were prevented by Piezo1 inhibition or knockdown. Mechanistically, Piezo1 activation promoted calcium-dependent Yes-associated protein (YAP) activation. YAP modulated GLS1-mediated glutaminolysis, which enhanced osteogenic differentiation through histone acetylation of runt-related transcription factor 2 (RUNX2) promoters. Together, our work provided a cross-talk between mechanotransduction and metabolism in the context of CAVD.

Abstract 100: Multi-omics And Single Nucleus Transcriptomics Reveal Aberrant Adaptive Immune Responses In Human Bicuspid Aortic Valves

Introduction: Bicuspid aortic valve (BAV) is the most common cause of adult congenital heart disease. Patients with BAVs comprise <2% of the population but represent ~50% of valve replacement surgeries and the pathogenic mechanisms underlying this disproportionate incidence of calcific aortic valve disease (CAVD) are unknown. We aimed to identify molecular contributors to accelerated disease in BAV-CAVD. Methods: Bulk multi-omics (miRNA-seq, RNA-seq, proteomics) was performed on 70 human aortic valves (11 non-diseased; fibrotic and calcific portions of 32 tricuspid aortic valves [TAVs] and 27 BAVs with CAVD). Single nuclei RNA-seq (snRNA-seq) was completed on 54,608 nuclei from 13 additional human valves (4 non-diseased; 5 TAVs and 4 BAVs with CAVD). Results: Calcific burden did not differ between diseased TAVs and BAVs (p=0.77), but BAV mineralization was significantly accelerated by 11.5±1.7 years vs. TAVs (p<0.001). Latent factor-based integration of covariate-corrected multi-omics analyses (q<0.05), CT-derived valve calcification, and 29 clinical parameters uncovered extensive involvement of adaptive immune responses where T cell/B cell inflammatory activation associated with autoimmune signals was enhanced in the early stages of BAV disease. Integrated multi-omics also revealed significantly elevated platelet activation potentially as a result of lifelong exposure to the high-shear BAV microenvironment, and implicated altered SLIT-ROBO signaling in BAV-CAVD progression. snRNA-seq identified 5 major cell types (27 states) in human aortic valves: valvular interstitial cells (65% of cells; 7 states), endothelial cells (10%; 4 states), macrophages (13%, 7 states), T cells (8%; 5 states), and B cells (3%; 4 states). CAVD drove differentiation of valve interstitial cells along distinct myofibrogenic ( ACTA2/CARMN/MYH11 -high) vs. osteogenic ( RUNX2/CDH11/POSTN -high) lineages, induction of endothelial-to-mesenchymal transition in valve endothelium and significant accumulation of specific macrophage and T-cell states (p<0.05) in BAV-CAVD. Conclusions: Aberrant adaptive immune responses are critical drivers of BAV-CAVD, and our findings delineate a novel strategy for discovery of morphology-specific therapeutics.

Purinergic Signaling in Pathologic Osteogenic Differentiation of Aortic Valve Interstitial Cells from Patients with Aortic Valve Calcification.

Purinergic signaling is associated with a vast spectrum of physiological processes, including cardiovascular system function and, in particular, its pathological calcifications, such as aortic valve stenosis. Aortic valve stenosis (AS) is a degenerative disease for which there is no cure other than surgical replacement of the affected valve. Purinergic signaling is known to be involved in the pathologic osteogenic differentiation of valve interstitial cells (VIC) into osteoblast-like cells, which underlies the pathogenesis of AS. ATP, its metabolites and related nucleotides also act as signaling molecules in normal osteogenic differentiation, which is observed in pro-osteoblasts and leads to bone tissue development. We show that stenotic and non-stenotic valve interstitial cells significantly differ from each other, especially under osteogenic stimuli. In osteogenic conditions, the expression of the ecto-nucleotidases ENTPD1 and ENPP1, as well as ADORA2b, is increased in AS VICs compared to normal VICs. In addition, AS VICs after osteogenic stimulation look more similar to osteoblasts than non-stenotic VICs in terms of purinergic signaling, which suggests the stronger osteogenic differentiation potential of AS VICs. Thus, purinergic signaling is impaired in stenotic aortic valves and might be used as a potential target in the search for an anti-calcification therapy.

Curcumin Involve the Myofibrosis Process of Rabbit Valve Interstitial Cells based on Expression Alpha- Smooth Muscle Actin: Experimental Posttest-only Control Group Design

Introduction: Following an acute rheumatic fever infection brought on by an inflammatory reaction to streptococcal bacteria, rheumatic heart valve disease results in valve degeneration. Elements of the immune system play an important role, in facilitating myofibroblast transdifferentiation and clearing damaged tissue of apoptotic cells. Myelofibrosis arising in valve components is the main cause of valve dysfunction. Valve myelofibrosis showed a significantly increased collagen, proteoglycan, and elastin content in myofibrotic valves compared to healthy valves. Objective: To establish curcumin’s capacity to prevent rabbit valve interstitial cells (VIC) from differentiating into myofibroblasts after being stimulated by TGF-1 by comparing the results to controls. Method: This study uses a posttest-only control group design for an in-vitro laboratory experiment. Heart VIC of a New Zealand rabbit were isolated (Oryctolagus cuniculus), and induced fibrosis by administration of TGF-β1 5 ng/mL. VIC pretreated with TGF-β1 were treated with low-dose curcumin (20 nanoM/L) and high-dose curcumin (50 nanoM/L). The immunocytochemical method based on SMA expression observed the inhibition of myofibroblastic differentiation. Statistical significance was analyzed by Kruskal-Wallis statistical test with a p-value < 0.05 as the limit of significance. Result: Administration of curcumin with low doses (20 nanoM/L) and high doses (50 nanoM/L), significantly decreased TGF-β1-induced myofibroblastic differentiation of VIC, which was characterized by decreased SMA expression in all low-dose curcumin treatment groups (20 nanoM/L) (1.40 ± 6.30) and high-dose curcumin (50 nanoM/L) (1.40 ± 8.30). Conclusion: Curcumin potentially prevent the development of SMA-expressing VIC into myofibroblasts.

Crosstalk between myofibroblasts and macrophages: A regulative factor of valvular fibrosis in calcific aortic valve disease

Inflammation and fibrosis are highly correlated with the progression of calcific aortic valve disease (CAVD). As one of the differentiated forms of valvular interstitial cells, myofibroblasts play a critical role in CAVD's development as do macrophages. Although numerous studies have been conducted on them separately, their communication and interaction remain unclear. We used porcine aortic valves to isolate valve interstitial cells (VICs). VICs were induced to differentiate into myofibroblasts by transforming growth factor-β1 (TGF-β1). After successful activation was determined, the myofibroblast-conditioned medium (CM) was collected and used to act on RAW264.7, a macrophage cell line. A migration and adhesion assay estimated the recruitment capability of myofibroblasts on macrophages. We used flow cytometry, quantitative polymerase chain reaction (qPCR), and Western blot analysis to investigate myofibroblasts' polarity promotion function in macrophages. Finally, we used macrophage-CM on VICs to explore the differentiation induction function of polarized macrophages. Myofibroblast marker alpha-smooth muscle actin and M2 macrophage marker CD163 were detected as upregulated in CAVD patients, and their expression has a certain correlation. The Smad3/HA/CD44 axis activated the differentiation of myofibroblasts by Western blot. The myofibroblast-CM can promote chemotaxis and adhesion of macrophages through protein kinase B/chemokine (C-C motif) ligand5 and Smad3/HA/CD44, respectively. Hyaluronic acid (HA) inside the myofibroblast-CM stimulates macrophages to polarize into M2 macrophages. In turn, M2 macrophage-CM has the promotive ability to activate myofibroblasts but fails to induce the osteoblast differentiation of VICs directly. The crosstalk between myofibroblasts and macrophages causes the excessive activation of myofibroblasts. This positive feedback loop may play a vital role in CAVD progression.

Disturbing effect of cepharanthine on valve interstitial cells calcification via regulating glycolytic metabolism pathways.

Osteogenic differentiation of valve interstitial cells (VICs) directly leads to aortic valve calcification, which is a common cardiovascular disease caused by inflammation and metabolic disorder. There is still no ideal drug for its treatment and prevention. The purpose of this study was to explore the effect and molecular mechanism of cepharanthine (CEP), a natural product, on inhibiting the osteogenic differentiation of VICs. First, CCK8 assay was used to evaluate cell viability of CEP on VICs. CEP concentration of 10μM was the effective dose with slight cytotoxicity, which was used for further study. The alizarin red staining analysis showed that CEP significantly inhibited calcium deposition caused by osteogenic medium related calcification induction. In order to explore the anti-calcification molecular mechanism of CEP, transcriptome and metabolome were synchronously used to discover the possible molecular mechanism and target of CEP. The results showed that CEP inhibited valve calcification by regulating the glycolytic pathway. The molecular docking of CEP and selected key factors in glycolysis showed significant binding energies for GLUT1 (-11.3kcal/mol), ENO1 (-10.6kcal/mol), PKM (-9.8kcal/mol), HK2 (-9.2kcal/mol), PFKM (-9.0kcal/mol), and PFKP (-8.9kcal/mol). The correlation analysis of RUNX2 expression and cellular lactate content showed R2 of 0.7 (p < 0.001). In conclusion, this study demonstrated that CEP inhibited osteoblastic differentiation of VICs by interfering with glycolytic metabolisms via downregulation of the production of lactate and glycolysis-associated metabolites.

Multi-omics of in vitro aortic valve calcification.

Heart valve calcification is an active cellular and molecular process that partly remains unknown. Osteogenic differentiation of valve interstitial cells (VIC) is a central mechanism in calcific aortic valve disease (CAVD). Studying mechanisms in CAVD progression is clearly needed. In this study, we compared molecular mechanisms of osteogenic differentiation of human VIC isolated from healthy donors or patients with CAVD by RNA-seq transcriptomics in early timepoint (48 h) and by shotgun proteomics at later timepoint (10th day). Bioinformatic analysis revealed genes and pathways involved in the regulation of VIC osteogenic differentiation. We found a high amount of stage-specific differentially expressed genes and good accordance between transcriptomic and proteomic data. Functional annotation of differentially expressed proteins revealed that osteogenic differentiation of VIC involved many signaling cascades such as: PI3K-Akt, MAPK, Ras, TNF signaling pathways. Wnt, FoxO, and HIF-1 signaling pathways were modulated only at the early timepoint and thus probably involved in the commitment of VIC to osteogenic differentiation. We also observed a significant shift of some metabolic pathways in the early stage of VIC osteogenic differentiation. Lentiviral overexpression of one of the most upregulated genes (ZBTB16, PLZF) increased calcification of VIC after osteogenic stimulation. Analysis with qPCR and shotgun proteomics suggested a proosteogenic role of ZBTB16 in the early stages of osteogenic differentiation.

Long noncoding TSI attenuates aortic valve calcification by suppressing TGF-β1-induced osteoblastic differentiation of valve interstitial cells

IntroductionCalcific aortic valve disease (CAVD) is an active and cellular-driven fibrocalcific process characterised by differentiation of valve interstitial cells (VICs) towards an osteogenic-like phenotype. A recently identified lncRNA, lncTSI, has been reported to inhibit fibrogenesis through transforming growth factor (TGF)-β/Smad3 pathway. Here, the present study aimed to investigate the role of lncTSI in CAVD. MethodsThe effect of TGF-β1 on lncTSI of VICs was measured. TGF-β1, RUNX2 and collagen I expression between calcified aortic valve tissue and normal samples by immunohistochemistry and western blotting. Human VICs were cultured and treated with TGF-β1. SiRNA and pcDNA3.1-lncTSI plasmid transfection were used to silence and overexpress lncTSI in VICs for 48 h, Smads phosphorylation, RUNX2 and collagen I expression were then verified by western blotting. In ApoE−/− mice fed with 0.25 % high-cholesterol diet, AAV2-lncTSI were injected intravenously to observe their effect on the formation of aortic valve calcification. ResultslncTSI was highly expressed in VICs treated with TGF-β1. lncTSI was transcriptionally regulated by Smad3 and reversely inhibited TGF-β1-induced Smad3 phosphorylation and downregulated profibrotic gene expression. Silencing lncTSI increased TGF-β1–induced Smad3 phosphorylation, and subsequently, upregulated RUNX2 and collagen I expressions in VICs. While overexpression of lncTSI reversed the production of RUNX2 and collagen I in VICs. In a mouse CAVD model of 24 week 0.25 % high-cholesterol diet feeding, overexpression of lncTSI significantly reduced calcium deposition, RUNX2, pSmad3, and collagen I expression in aortic valve leaflets, with less aortic valve stenosis. ConclusionsThe novel findings of present study suggested that lncTSI alleviated aortic valve calcification through negative regulation of the TGF-β/Smad3 pathway. The results may help elucidate new diagnostic and therapeutic targets to prevent CAVD progression.

LXR-beta signalling is a key mediator in the pathogenesis of aortic valve stenosis and its prevention by saringosterol

Abstract Background Cholesterol metabolism contributes as a risk factor for aortic valve stenosis (AS), but pharmacological approaches remained unsatisfying. The liver-X-receptor (LXR) is a key regulator in cholesterol metabolism, though its clinical use is limited due to unwanted side effects. The seaweed-derived oxysterol saringosterol is an agonist of the LXRβ, promising a more favourable tolerability. Purpose This study aimed to better understand the pathophysiology of aortic valve stenosis and to assess the potential of saringosterol as a targeted pharmacotherapy. Methods Tissue samples from aortic valves were collected from patients with AS or aortic valve regurgitation (AR). Transcriptomics were performed and gene ontology (GO) analysis was used to determine pathways and genes that are relevant to AS, and then validated using qPCR. In vivo, mice received a wire-induced aortic valve stenosis and were either fed a diet supplemented with saringosterol or control diet. Haemodynamic characteristics were assessed using echocardiography. Additionally, hepatic concentrations of saringosterol, expression of LXRβ regulated genes as well as aortic valve thickness and composition were assessed. In vitro, human aortic valve interstitial cells (VIC) were cultured in a procalcifing medium and stimulated with saringosterol to investigate the underlying molecular mechanisms. Results Transcriptomic analysis of AS samples revealed the regulation of several GO-terms related to cholesterol- or lipid metabolism. Many of the genes identified were regulated by LXRβ, suggesting its pathophysiological relevance in AS. We validated this assumption by performing qPCR from aortic valves for the most prominent downstream targets of LXRβ, ABCA1 and ABCG1, with both being differentially regulated. In vivo, treatment with saringosterol for six weeks resulted in a significant accumulation of saringosterol in liver tissue as well as induction of LXRβ-regulated genes. Furthermore, treatment with saringosterol strikingly reduced the development of AS after wire injury as assessed by echocardiographic and histological measurements. In vitro, the differentiation of VIC into osteoblastic and myofibroblastic phenotypes was abolished by saringosterol, which reduced the expression of the procalcifying mediators RUNX-2 and ACTA-2 in a dose-dependent manner. Conclusion We identified LXRβ-signalling as a key regulator in the pathophysiology of AS. Transcriptomic analyses revealed that cholesterol metabolism was altered in human AS, and many of the genes involved were linked to the LXRβ. In a murine model, we demonstrated that oral application of saringosterol induced LXRβ-activity and mitigated the development of AS. In vitro experiments demonstrated that saringosterol prevents adverse cell differentiation of VIC, which provides a mechanistic explanation. Funding Acknowledgement Type of funding sources: Public Institution(s). Main funding source(s): BONFOR Universität Bonn

Crenigacestat (LY3039478) inhibits osteogenic differentiation of human valve interstitial cells from patients with aortic valve calcification in vitro.

Calcific aortic valve disease (CAVD) is one of the dangerous forms of vascular calcification. CAVD leads to calcification of the aortic valve and disturbance of blood flow. Despite high mortality, there is no targeted therapy against CAVD or vascular calcification. Osteogenic differentiation of valve interstitial cells (VICs) is one of the key factors of CAVD progression and inhibition of this process seems a fruitful target for potential therapy. By our previous study we assumed that inhibitors of Notch pathway might be effective to suppress aortic valve leaflet calcification. We tested CB-103 and crenigacestat (LY3039478), two selective inhibitors of Notch-signaling, for suppression of osteogenic differentiation of VICs isolated from patients with CAVD in vitro. Effect of inhibitors were assessed by the measurement of extracellular matrix calcification and osteogenic gene expression. For effective inhibitor (crenigacestat) we also performed MTT and proteomics study for better understanding of its effect on VICs in vitro. CB-103 did not affect osteogenic differentiation. Crenigacestat completely inhibited osteogenic differentiation (both matrix mineralization and Runx2 expression) in the dosages that had no obvious cytotoxicity. Using proteomics analysis, we found several osteogenic differentiation-related proteins associated with the effect of crenigacestat on VICs differentiation. Taking into account that crenigacestat is FDA approved for clinical trials for anti-tumor therapy, we argue that this drug could be considered as a potential inhibitor of cardiovascular calcification.

Overexpressed Thrombospondin 2 Induced Osteogenic Differentiation of Valve Interstitial Cells via Inhibition of Akt/NF-κB Signaling Pathway to Promote Calcific Aortic Valve Disease Development.

Thrombospondin 2 (THBS2) is reported to participate in the development of calcific aortic valve disease (CAVD), while the effects are not elucidated completely. The study aimed to explore the role and mechanism of THBS2 in CAVD. Differentially expressed genes related to stenosis and sclerosis were screened through Limma package based on data from Gene Expression Omnibus (GEO), and the functional enrichment analysis was performed by the Database for Annotation, Visualization and Integrated Discovery (DAVID) database. The immunoreactivity of THBS2 in CAVD and normal samples was detected through immunohistochemistry. Valve interstitial cells (VICs) were transfected with short hairpin RNA against THBS2 (shTHBS2) and THBS2 overexpression plasmid and treated with LY294002 (Akt inhibitor) and induced osteogenic differentiation. The expression of THBS2 in CAVD and normal samples and the levels of THBS2, osteocalcin, Runx2, SPARC, COL1A2, COL1A1, SPP1, CTGF, MMP-2, MMP-13, Akt, p-Akt, p65, p-p65, and nuclear p65 in VICs were tested by qRT-PCR and Western blot. ALP activity was assessed using colorimetry. Calcic nodule formation was measured by Alizarin Red staining. THBS2 and PI3K-Akt pathway were differentially enriched in stenosis samples when compared with those in sclerosis samples. THBS2 expression was upregulated in CAVD and positively correlated with ALP activity, calcic nodule formation, osteogenic differentiation-related (osteocalcin, Runx2, SPARC, COL1A2, COL1A1, SPP1, and CTGF) and extracellular matrix– (ECM–) related (MMP-2 and MMP-13) factors in the process of osteogenic differentiation. ShTHBS2 suppressed ALP activity, calcic nodule formation, and osteogenic differentiation/ECM-related molecules while upregulating p-Akt/Akt, p-p65/p65, and nuclear p65 expressions in VICs during osteogenic differentiation. However, THBS2 overexpression had the opposite effect to shTHBS2, and LY294002 reversed the effect of shTHBS2. Collectively, overexpressed THBS2 induces the osteogenic differentiation of VICs via inhibiting Akt/NF-κB pathway to promote the development of CAVD.

Olmesartan inhibits transdifferentiation of rabbit’s valvular interstitial cells into myofibroblast based on α – smooth muscle actin expression

Recent studies revealed that differentiation of valvular interstitial cell (VIC) into myofibroblasts played an important role in valvular remodeling and fibrosis. Study was performed on in vitro cultured of VIC from New Zealand rabbit (Oryctolagus cuniculus). Isolated VIC was pretreated using 5 ng/mL of TGF-β1 and divided into groups of olmesartan (100 nanomol/L) as short 30 minutes exposure duration and as continuous 72 hours exposure duration. Inhibition of myofibroblast differentiation was quantified by the expression of α-SMA levels detected by immunofluorescence staining. Olmesartan administration either, as short 30 minutes exposure duration or as continuous 72 hours exposure duration, were significantly reduced TGF-β1-induced VIC differentiation into myofibroblast expressed by α-SMA levels compared to control (short 30 minutes exposure duration: 9.18 ±2.25, as continuous 72 hours exposure duration: 10.13 ±0.69, and control 22.29 ±2.78; p &lt; 0.001), but without significant difference between the two treatment groups (p 0.403). Olmesartan both on short and continuous exposure can inhibit the differentiation of valve interstitial cells into myofibroblasts based on the expression of αSMA, but without a significant difference in the inhibitory effect.

Berberine inhibits osteogenic differentiation of aortic valve interstitial cells induced by osteogenic induction medium

This research focused on the effect and mechanism of berberine on osteogenic differentiation of valve interstitial cells(VICs) induced by osteogenic induction medium, in order to provide new insights into the clinical treatment of calcified aortic valve disease. The expression of osteogenic and fibrotic makers in three cases of calcified valve tissues and one case of normal control was assayed by Western blot. After the porcine aortic VICs were isolated, the effects of different concentrations of berberine on their viability were examined by MTT assay for determining the optimal concentration range. VICs were cultured in osteogenic induction medium and treated with different concentrations of berberine. Western blot and q-PCR were conducted to detect the effects of berberine on the expression of osteogenic and fibrotic makers in VICs. The effects of berberine on osteogenic differentiation of VICs in the early and late stages were separately measured by ALP staining and alizarin red S staining. The effects of berberine on the phosphorylation of ERK1/2 at different time points were assayed by Western blot. And PD98059, an inhibitor of ERK1/2, was added for verification. The results suggested that related osteogenic and fibrotic makers were significantly up-regulated in calcified valve tissues as compared with those in the normal control. The up-regulated fibrosis and osteogenic makers of VICs under osteogenic conditions were reversed by berberine and the ALP activity and calcium deposition in VICs were also reduced obviously. The level of ERK1/2 phosphorylation was decreased. Similarly, the osteogenic and fibrotic makers of VICs induced by osteogenic induction medium were lowered by PD98059. This study has confirmed that berberine is able to inhibit the differentiation of VICs into myofibroblasts or osteoblast-like cells, which may be associated with the inhibition of ERK1/2 signaling pathway.

Atractylenolide-1 Targets FLT3 to Regulate PI3K/AKT/HIF1-α Pathway to Inhibit Osteogenic Differentiation of Human Valve Interstitial Cells.

Atractylenolide-1 (AT-1), a natural active ingredient extracted from Atractylodes macrocephala, was reported to have good anti-fibrotic and anti-inflammatory effects. Osteogenic changes induced by the inflammation of valve interstitial cells (VICs) play a role in the development of calcified aortic valve disease (CAVD). This study aimed to investigate the anti-osteogenic effects of AT-1 in human VICs. Human VICs were exposed to osteogenic induction medium (OM) containing AT-1 to analyze cell viability, as well as protein and osteogenic gene expression. Anti-calcification tests were also performed. mRNA transcriptome sequencing was performed to identify differential genes and pathways regulated by AT-1. Western blotting was used to verify the enrichment pathway, protein-protein interaction (PPI) analysis was conducted to identify drug targets. Finally, molecular docking and inhibitors are used to verify the drug targets. Treatment of VICs with 20 μM AT-1 resulted in no significant cytotoxicity. The addition of AT-1 to OM prevented the accumulation of calcified nodules, and decreases in the level of (Alkaline Phosphatase) ALP and RUNX2 gene and protein expression were observed. Atractylenolide-1 can target FLT3 protein and inhibit the phosphorylation of FLT3, thereby blocking PI3K/AKT pathway activation, reducing the production of Hypoxia inducible factor(HIF)1-α, and inhibiting the osteogenic differentiation of VICs. These results suggest AT-1 as a potential drug for treating calcified aortic valve disease.

Resveratrol exhibits inhibition effects on osteogenic differentiation of aortic valve interstitial cells by interfering with the AKT pathway

• The expression of osteogenic markers are increased in the aortic valve tissues of patients with calcific aortic valve disease. • Resveratrol inhibits the osteogenic medium-induced osteogenic differentiation of valve interstitial cells. • Resveratrol inhibits the osteogenic differentiation of valve interstitial cells via interfering with AKT signaling pathway activation. • RES may become a potential natural drug for the treatment of calcific aortic valve disease. Resveratrol is a natural active ingredient found in many plants and has a protective effect on cardiovascular diseases. However, it has not been reported that whether resveratrol can inhibit calcific aortic valve disease(CAVD). In this study, we want to explore the effect and mechanism of resveratrol on the osteogenic differentiation of valve interstitial cells（VICs）.We first found that the expression of osteogenic markers in calcified human aortic valve. Western blotting, ALP staining and Alizarin red S staining showed that under osteogenic medium (OM) treatment, resveratrol can inhibit VICs from expressing osteogenic markers, reduce ALP content and calcium Nodule formation. Mechanistically, resveratrol can inhibit the activation of the AKT/Smad1/5/8 pathway induced by OM. We selected the AKT pathway for verification and determined that resveratrol inhibited the osteogenic differentiation of VICs by inhibiting the AKT pathway. Collectively, resveratrol may become a potential natural drug for the treatment of CAVD.

Berberine inhibits osteogenic differentiation of aortic valve interstitial cells by interfering Smad1/5/8 and NF-κB pathways

AimsCalcified aortic valve disease (CAVD) is a cardiovascular disease with increasing morbidity and mortality. The pathogenetic cellular mechanism is the phenotypic transition of aortic valve interstitial cells (VICs). Here, we explored the effect of berberine (BBR) on the phenotypic transition of VICs and elucidated the underlying molecular mechanisms, providing a theoretical basis in finding novel clinical treatments for CAVD. Methods and resultsCalcific aortic valves and normal controls were collected for western blot and the results demonstrated that osteogenic and inflammatory markers were significantly up-regulated in calcific aortic valves. BBR inhibited inflammation and osteogenic differentiation of VICs under osteogenic conditions, as well as alkaline phosphatase activity and calcified nodule formation. Mechanistically, BBR could inhibit the activation of Smad1/5/8 and NF-κB pathways under OM conditions. LDN193189 and BAY11–7082, the inhibitor of Smad1/5/8 and NF-κB respectively, were added for further verification. Similarly, the osteogenic and fibrotic markers of VICs induced by osteogenic induction medium were decreased by LDN193189 and BAY11–7082. Western blot was used to examine upstream receptors of Smad1/5/8, the results showed that BBR inhibited the activation of Smad1/5/8 by downregulating ALK2 and ALK3. ConclusionBBR decreased the inflammatory factors and suppressed the osteogenic differentiation of VICs, which might be associated with the inhibition of Smad1/5/8 and NF-κB signaling pathways.

Blocking the NLRP3 inflammasome reduces osteogenic calcification and M1 macrophage polarization in a mouse model of calcified aortic valve stenosis

Background and aimsActivated innate immune cells infiltrating the valve and their secreted cytokines drive the differentiation of valve interstitial cells into myofibroblastic and osteoblastic phenotypes in calcified aortic valve stenosis (CAVS). In this study, we investigated how NLRP3 inhibition with CY-09 reduces aortic valve stenosis and calcification. MethodsApoE−/− mice were fed a high-fat diet for 24 weeks with or without intraperitoneal injection of 2.5 mg/kg/day NLRP3 inhibitor CY-09 for 42 consecutive days, while the control group mice were fed a normal diet. The valve function was monitored by echocardiography; calcified nodules were assessed by Von Kossa staining; and calcification-related molecules, inflammatory factors, and white leucocyte influx into the valve were assessed by immunohistochemistry, TUNEL assay, and PCR. ResultsMice treated with CY-09 exhibited improved aortic valve function and reduced valve calcification deposition. CY-09 intervention significantly downregulated the elevated expression of the NLRP3 inflammasome pathway molecules NLRP3, caspase-1, and IL-1β and the osteogenic calcification markers RUNX2, SPARC, and BMP2 in stenotic valves, while the number of apoptotic cells and dystrophic calcification markers CDH11 and α- SMA did not change significantly. Inhibition of NLRP3 activity also reduced the ratio of M1/M2 macrophages, prevented the shift of macrophages towards the M1 phenotype, and downregulated the levels of the proinflammatory factors IL-6 and TNF-α. ConclusionsThis study provides a proof-of-concept that pharmacological inhibition of the NLRP3 inflammasome is a feasible strategy for alleviating aortic valve calcification and stenosis.