Discoidin domain receptor-1 regulates calcific extracellular vesicle release in vascular smooth muscle cell fibrocalcific response via transforming growth factor-β signaling

\u3cp\u3eObjective - Collagen accumulation and calcification are major determinants of atherosclerotic plaque stability. Extracellular vesicle (EV)-derived microcalcifications in the collagen-poor fibrous cap may promote plaque rupture. In this study, we hypothesize that the collagen receptor discoidin domain receptor-1 (DDR-1) regulates collagen deposition and release of calcifying EVs by vascular smooth muscle cells (SMCs) through the transforming growth factor-β (TGF-β) pathway. Approach and Results - SMCs from the carotid arteries of DDR-1\u3csup\u3e-/-\u3c/sup\u3e mice and wild-type littermates (n=5-10 per group) were cultured in normal or calcifying media. At days 14 and 21, SMCs were harvested and EVs isolated for analysis. Compared with wild-type, DDR-1\u3csup\u3e-/-\u3c/sup\u3e SMCs exhibited a 4-fold increase in EV release (P-/- phenotype was characterized by increased mineralization (Alizarin Red S and Osteosense, P-/- SMCs in calcifying media (P-/- phenotype, corroborating a causal relationship between DDR-1 and TGF-β in EV-mediated vascular calcification. Conclusions - DDR-1 interacts with the TGF-β pathway to restrict calcifying EV-mediated mineralization and fibrosis by SMCs. We therefore establish a novel mechanism of cell-matrix homeostasis in atherosclerotic plaque formation.\u3c/p\u3

Discoidin domain receptor-1 regulates calcific extracellular vesicle release in vascular smooth muscle cell fibrocalcific response via transforming growth factor- signaling Citation for published version (APA): Discoidin Domain Receptor-1 Regulates Calcif

• A submitted manuscript is the version of the article upon submission and before peer-review. There can be important differences between the submitted version and the official published version of record. People interested in the research are advised to contact the author for the final version of the publication, or visit the DOI to the publisher's website. • The final author version and the galley proof are versions of the publication after peer review. • The final published version features the final layout of the paper including the volume, issue and page numbers. Link to publication General rights Copyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights. • Users may download and print one copy of any publication from the public portal for the purpose of private study or research. • You may not further distribute the material or use it for any profit-making activity or commercial gain • You may freely distribute the URL identifying the publication in the public portal. If the publication is distributed under the terms of Article 25fa of the Dutch Copyright Act, indicated by the "Taverne" license above, please follow below link for the End User Agreement: www.tue.nl/taverne Take down policy If you believe that this document breaches copyright please contact us at: [email protected] providing details and we will investigate your claim. Abstract Objective: Collagen accumulation and calcification are major determinants of atherosclerotic plaque stability. Extracellular vesicle (EV)-derived microcalcifications in the collagen-poor fibrous cap may promote plaque rupture. In this study, we hypothesize that the collagen receptor discoidin domain receptor-1 (DDR-1) regulates collagen deposition and release of calcifying EVs by vascular smooth muscle cells (vSMCs) through the TGF-β pathway. Approach and Results: VSMCs from the carotid arteries of DDR-1 -/-mice and wild type littermates (n=5-10 per group) were cultured in normal or calcifying media. At days 14 and 21, vSMCs were harvested and EVs isolated for analysis. Compared to wild type, DDR-1 -/-vSMCs exhibited a 4-fold increase in EV release (p<0.001) with concomitantly elevated alkaline phosphatase (ALP) activity (p<0.0001) as a hallmark of EV calcifying potential. The DDR-1 -/-phenotype was characterized by increased mineralization (Alizarin Red S and Osteosense, p<0.001 and p=0.002, respectively) and amorphous collagen deposition (p<0.001). We further identified a novel link between DDR-1 and the TGF-β pathway previously implicated in both fibrotic and calcific responses. An increase in TGF-β1 release by DDR-1 -/-vSMCs in calcifying media (p<0.001) stimulated p38 phosphorylation (p=0.02) and suppressed activation of Smad3. Inhibition of either TGF-β receptor-I or phospho-p38 reversed the fibrocalcific DDR-1 -/-phenotype, corroborating a causal relationship between DDR-1 and TGF-β in EV-mediated vascular calcification. Conclusion: DDR-1 interacts with the TGF-β pathway to restrict calcifying EV-mediated mineralization and fibrosis by vSMCs. We therefore establish a novel mechanism of cellmatrix homeostasis in atherosclerotic plaque formation

Mindfulness Predicts Lower Affective Volatility among African Americans During Smoking Cessation

Recent research suggests that mindfulness benefits emotion regulation and smoking cessation. However, the mechanisms by which mindfulness affects emotional and behavioral functioning are unclear. One potential mechanism, lower affective volatility, has not been empirically tested during smoking cessation. This study examined longitudinal associations among mindfulness and emotional responding over the course of smoking cessation treatment among predominantly low-socioeconomic status (SES) African American smokers, who are at high risk for relapse to smoking and tobacco-related health disparities. Participants (N = 399, 51% female, mean age = 42, 48% with annual income <$10,000) completed a baseline measure of trait mindfulness. Negative affect, positive affect, and depressive symptoms were assessed at five time points during smoking cessation treatment (up to 31 days postquit). Volatility indices were calculated to quantify within-person instability of emotional symptoms over time. Over and above demographic characteristics, nicotine dependence, and abstinence status, greater baseline trait mindfulness predicted lower volatility of negative affect and depressive symptoms surrounding the quit attempt and up to 1 month postquit, ps < 0.05. Although volatility did not mediate the association between greater mindfulness and smoking cessation, these results are the first to show that mindfulness is linked to lower affective volatility (or greater stability) of negative emotions during the course of smoking cessation. The present study suggests that mindfulness is linked to greater emotional stability and augments the study of mindfulness in diverse populations. Future studies should examine the effects of mindfulness-based interventions on volatility and whether lower volatility explains effects of mindfulness-based treatments on smoking cessation

Myocardial Infarction Alters Adaptation of the Tethered Mitral Valve

BACKGROUND: In patients with myocardial infarction (MI), leaflet tethering by displaced papillary muscles induces mitral regurgitation (MR), which doubles mortality. Mitral valves (MVs) are larger in such patients but fibrosis sets in counterproductively. The investigators previously reported that experimental tethering alone increases mitral valve area in association with endothelial-to-mesenchymal transition. OBJECTIVES: The aim of this study was to explore the clinically relevant situation of tethering and MI, testing the hypothesis that ischemic milieu modifies mitral valve adaptation. METHODS: Twenty-three adult sheep were examined. Under cardiopulmonary bypass, the papillary muscle tips in 6 sheep were retracted apically to replicate tethering, short of producing MR (tethered alone). Papillary muscle retraction was combined with apical MI created by coronary ligation in another 6 sheep (tethered plus MI), and left ventricular remodeling was limited by external constraint in 5 additional sheep (left ventricular constraint). Six sham-operated sheep were control subjects. Diastolic mitral valve surface area was quantified by 3-dimensional echocardiography at baseline and after 58 ± 5 days, followed by histopathology and flow cytometry of excised leaflets. RESULTS: Tethered plus MI leaflets were markedly thicker than tethered-alone valves and sham control subjects. Leaflet area also increased significantly. Endothelial-to-mesenchymal transition, detected as α-smooth muscle actin-positive endothelial cells, significantly exceeded that in tethered-alone and control valves. Transforming growth factor-β, matrix metalloproteinase expression, and cellular proliferation were markedly increased. Uniquely, tethering plus MI showed endothelial activation with vascular adhesion molecule expression, neovascularization, and cells positive for CD45, considered a hematopoietic cell marker. Tethered plus MI findings were comparable with external ventricular constraint. CONCLUSIONS: MI altered leaflet adaptation, including a profibrotic increase in valvular cell activation, CD45-positive cells, and matrix turnover. Understanding cellular and molecular mechanisms underlying leaflet adaptation and fibrosis could yield new therapeutic opportunities for reducing ischemic MR

Loss-of-function genomic variants highlight potential therapeutic targets for cardiovascular disease.

Pharmaceutical drugs targeting dyslipidemia and cardiovascular disease (CVD) may increase the risk of fatty liver disease and other metabolic disorders. To identify potential novel CVD drug targets without these adverse effects, we perform genome-wide analyses of participants in the HUNT Study in Norway (n = 69,479) to search for protein-altering variants with beneficial impact on quantitative blood traits related to cardiovascular disease, but without detrimental impact on liver function. We identify 76 (11 previously unreported) presumed causal protein-altering variants associated with one or more CVD- or liver-related blood traits. Nine of the variants are predicted to result in loss-of-function of the protein. This includes ZNF529:p.K405X, which is associated with decreased low-density-lipoprotein (LDL) cholesterol (P = 1.3 × 10-8) without being associated with liver enzymes or non-fasting blood glucose. Silencing of ZNF529 in human hepatoma cells results in upregulation of LDL receptor and increased LDL uptake in the cells. This suggests that inhibition of ZNF529 or its gene product should be prioritized as a novel candidate drug target for treating dyslipidemia and associated CVD