Loss of soluble guanylyl cyclase in platelets contributes to atherosclerotic plaque formation and vascular inflammation

Aim: The role of platelets in atherosclerosis remains incompletely understood. Variants in genes encoding the soluble guanylyl cyclase (sGC) in platelets are associated with coronary artery disease (CAD) risk. Here we sought to investigate the contribution of platelet sGC to atherosclerosis and the therapeutic potential of targeting sGC in atherosclerosis. Methods and Results: We genetically deleted sGC in platelets of atherosclerosis-prone Ldlr-/- mice. By intravital fluorescence microscopy such Pf4-Cre+Gucy1b1flox/floxLdlr-/- mice displayed enhanced leukocyte adhesion to atherosclerotic plaques in comparison with their litter mates. Moreover, histological and flow cytometry analyses revealed more numerous inflammatory leukocytes and larger plaque sizes in aortic tissue of Ldlr-/- mice lacking sGC in platelets. In vitro, supernatant from activated platelets lacking sGC promoted leukocyte adhesion to endothelial cells (EC) via enhanced EC activation. Using cytokine profiling, we identified reduced angiopoietin-1 release by Pf4-Cre+Gucy1b1flox/flox and human GUCY1A1 risk allele carrier platelets to be responsible for enhanced activation of EC and subsequent leukocyte adhesion. Pharmacological sGC stimulation increased platelet angiopoietin-1 release in vitro and reduced recruitment of adoptively transferred leukocytes in Ldlr-/- mice fed a Western diet. Pharmacological sGC stimulation further reduced atherosclerotic plaque formation and vascular inflammation. Conclusion: Loss of sGC in platelets contributes to atherosclerotic plaque formation via reduced release of the soluble factor angiopoietin-1 and, subsequently, enhanced leukocyte recruitment. Pharmacological sGC stimulation might represent a novel therapeutic strategy to prevent and treat CAD.

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Abstract 471: Influence of Platelet-specific Soluble Guanylyl Cyclase Deficiency on Atherosclerotic Plaque Formation

Arteriosclerosis Thrombosis and Vascular Biology ◽

10.1161/atvb.38.suppl_1.471 ◽

2018 ◽

Vol 38 (Suppl_1) ◽

Author(s):

Marlène Stroth ◽

Noomen Bettaga ◽

Jana Wobst ◽

Julia Werner ◽

Anna-Sophia Zimmermann ◽

...

Keyword(s):

Atherosclerotic Plaque ◽

Guanylyl Cyclase ◽

Soluble Guanylyl Cyclase ◽

Plaque Formation ◽

Atherosclerotic Plaque Formation

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ADAMTS13 reduces vascular inflammation and the development of early atherosclerosis in mice

Blood ◽

10.1182/blood-2011-09-376202 ◽

2012 ◽

Vol 119 (10) ◽

pp. 2385-2391 ◽

Cited By ~ 65

Author(s):

Chintan Gandhi ◽

Mohammad Moshahid Khan ◽

Steven R. Lentz ◽

Anil K. Chauhan

Keyword(s):

Atherosclerotic Plaque ◽

Leukocyte Adhesion ◽

Vascular Inflammation ◽

Fold Increase ◽

Plaque Formation ◽

Aortic Sinus ◽

Atherosclerotic Lesions ◽

Atherosclerotic Plaque Formation ◽

Von Willebrand ◽

Early Atherosclerosis

Abstract ADAMTS13, a metalloprotease, plays a pivotal role in preventing spontaneous microvascular thrombosis by cleaving hyperactive ultra large von Willebrand factor multimers into smaller, less active multimers. Reduced ADAMTS13 activity in plasma has been described in many diseases associated with systemic inflammation. It remains uncertain, however, whether ADAMTS13 contributes to disease pathogenesis or rather simply serves as an inflammation-associated marker. We hypothesized that, by decreasing vascular inflammation, ADAMTS13 reduces the development of early atherosclerotic plaques. Using intravital fluorescence microscopy, we observed excessive leukocyte adhesion and accelerated atherosclerotic plaque formation at the carotid sinus of Adamts13−/−/ApoE−/− mice compared with ApoE−/− mice fed a high-fat Western diet. At 4 months of age, there was a significant increase in atherosclerosis in the aorta and aortic sinus of Adamts13−/−/ApoE−/− mice compared with ApoE−/− mice. Interestingly, we detected a 2-fold increase in macrophage recruitment to the atherosclerotic plaque of the Adamts13−/−/ApoE−/− mice compared with ApoE−/− mice, suggesting that the atherosclerotic lesions in these mice were not only larger but also more inflammatory. These findings reveal a new functional role for the antithrombotic enzyme ADAMTS13 in reducing excessive vascular inflammation and plaque formation during early atherosclerosis.

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Abstract 444: Semaphorin3A Reduces Atherosclerotic Plaque Formation in ApoE Knock Out Mice Through Regulation of M2 Type Macrophage Migration

Arteriosclerosis Thrombosis and Vascular Biology ◽

10.1161/atvb.36.suppl_1.444 ◽

2016 ◽

Vol 36 (suppl_1) ◽

Author(s):

Talin Ebrahimian ◽

Maryam Heidari ◽

David Simon ◽

Hojatollah Vali ◽

Craig A Mandato ◽

...

Keyword(s):

Atherosclerotic Plaque ◽

Inflammatory Diseases ◽

Plaque Formation ◽

Atherosclerotic Plaques ◽

M2 Macrophages ◽

Aortic Sinus ◽

Knock Out ◽

Atherosclerotic Plaque Formation ◽

Beta 1 Integrin

Objective: Recent data point to an important immunomodulatory role for neural guidance molecules, including semaphorin 3a (Sema-3A), in inflammatory diseases. Sema-3A is a secreted member of the Sema family and is produced by several immune cells including macrophages. We found that Sema-3A receptors are expressed in macrophages and in atherosclerotic plaques. Approach and results: To investigate the role of Sema-3A in atherosclerosis, ApoE-/- mice were administered with a Sema-3A overexpressing or a control plasmid and were fed a high fat diet for 9 weeks. Sema-3A receptors were expressed in macrophages and atherosclerotic plaques. Our results show that Sema-3A overexpressing mice had significantly smaller atherosclerotic plaques than control mice in the aortic sinus (0.3±0.02 vs. 0.4±0.03 mm 2 ), the brachiocephalic artery (0.04±0.01 vs. 0.1±0.01 mm 2 ) and the aorta (9.5±1.4 vs 15.3±2.9%), assessed by oil red O staining. No differences were observed in plaque stability, measured by collagen and smooth muscle cell alpha-actin staining. However, there was significantly less (2-fold) macrophage content in the plaques of Sema-3A compared to control mice, associated with decreased circulating monocytes determined by flow cytometry as cd11b positive and Gr-1 negative cells (4.97±0.74 vs. 7.2±0.62%). To better define the involved mechanisms, we investigated macrophage function In vitro and found that recombinant Sema-3A increased by 4 fold migration of M2 but not M1 macrophages. In addition, active beta-1 integrin expression was significantly enhanced (2-fold) by Sema-3A in human M2 macrophages. Importantly, Sema-3A induced a significant increase (by 50%) of focal adhesion kinase phosphorylation. Conclusions: Our data show that Sema-3A prevents atherosclerotic plaque formation in ApoE -/- mice. This may be due in part to enhanced motility and function of M2 macrophages through regulation of beta-1 integrin.

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Melanocortin overexpression limits diet-induced inflammation and atherosclerosis in LDLR−/− mice

Journal of Endocrinology ◽

10.1530/joe-17-0636 ◽

2018 ◽

Vol 236 (3) ◽

pp. 111-123 ◽

Cited By ~ 4

Author(s):

Salla Nuutinen ◽

Liisa Ailanen ◽

Eriika Savontaus ◽

Petteri Rinne

Keyword(s):

Atherosclerotic Plaque ◽

Vascular Inflammation ◽

Low Density Lipoprotein ◽

Density Lipoprotein ◽

Plaque Formation ◽

Western Diet ◽

Low Density ◽

Long Term Effects ◽

Melanocortin System ◽

Atherosclerotic Plaque Formation

Atherosclerosis is a chronic inflammatory disease of the arteries. The disease is initiated by endothelial dysfunction that allows the transport of leukocytes and low-density lipoprotein into the vessel wall forming atherosclerotic plaques. The melanocortin system is an endogenous peptide system that regulates, for example, energy homeostasis and cardiovascular function. Melanocortin treatment with endogenous or synthetic melanocortin peptides reduces body weight, protects the endothelium and alleviates vascular inflammation, but the long-term effects of melanocortin system activation on atheroprogression remain largely unknown. In this study, we evaluated the effects of transgenic melanocortin overexpression in a mouse model of atherosclerosis. Low-density lipoprotein receptor-deficient mice overexpressing alpha- and gamma3-MSH (MSH-OE) and their wild-type littermates were fed either a regular chow or Western-style diet for 16 weeks. During this time, their metabolic parameters were monitored. The aortae were collected for functional analysis, and the plaques in the aortic root and arch were characterised by histological and immunohistochemical stainings. The aortic expression of inflammatory mediators was determined by quantitative PCR. We found that transgenic MSH-OE improved glucose tolerance and limited atherosclerotic plaque formation particularly in Western diet-fed mice. In terms of aortic vasoreactivity, MSH-OE blunted alpha1-adrenoceptor-mediated vasoconstriction and enhanced relaxation response to acetylcholine, indicating improved endothelial function. In addition, MSH-OE markedly attenuated Western diet-induced upregulation of proinflammatory cytokines (Ccl2, Ccl5 and Il6) that contribute to the pathogenesis of atherosclerosis. These results show that the activation of the melanocortin system improves glucose homeostasis and limits diet-induced vascular inflammation and atherosclerotic plaque formation.

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