Atherosclerotic Plaque Development Research Articles

Effects of diet on atherosclerotic plaque development.

Effects of diet on atherosclerotic plaque development.

Subclinical atherosclerosis burden in carotid and femoral territories in HIV subjects: relationships with HIV and non-HIV related factors

BackgroundCardiovascular disease is a major cause of morbidity in an aging HIV population. However, risk estimation with the most frequent equations usually classifies HIV patients as having a low or moderate risk. Several studies have described a very high prevalence of subclinical atherosclerosis in a middle-aged, non-HIV population. There is insufficient body of knowledge to understand if this is the case in people living with HIV (PLWH). We aim to calculate the proportion of patients with subclinical atherosclerosis in a single site cohort of HIV-infected subjects.MethodsWe have analyzed chronically HIV infected adults (≥ 18 years) who were on active follow-up in an HIV unit specialized in the care of cardiovascular health. The most recent clinical visit and vascular ultrasonography were used to assess the objectives of our research. Our primary objective was to describe the proportion of participants with subclinical atherosclerosis (focal protrusion into the lumen > 0.5 mm or > 50% of the surrounding IMT or a diffuse thickness > 1.5 mm) in a single site cohort of PLWH. Carotid and iliofemoral territories were evaluated. As a secondary objective we have run a multivariate analysis to determine which HIV and non-HIV factors might be related with the presence of atherosclerotic plaques.FindingsWe included a total of 463 participants between November 2017 to October 2019. Subjects were predominantly male (84.2%) with a mean age of 48.8 years (SD 10.7). Hypercholesterolemia (36%) was the most prevalent comorbidity followed by Hypertension (18%) and Hypertriglyceridemia (16%). Mean duration of HIV infection is 12.3 years. Overall, participants had been receiving cART for a median of 9.5 years. Subclinical atherosclerosis was found in 197 subjects (42.5%; CI 95% [38.0–47.2]). The disease was found more frequently in the femoral arteries (37.8%) than in the carotid vascular bed (18.6%). Despite some HIV factors correlated with the presence of plaques in a univariate analysis (e.g., time with HIV-1 RNA > 50 copies/mL or time from HIV diagnosis), the only two explanatory factors that remained associated with the presence of atherosclerotic plaques in the multivariate analysis were smoking (OR 5.47, 95% CI 3.36 – 8.90) and age (OR 1.13, 95%CI 1.10 – 1.16).InterpretationWe have found a very high prevalence of subclinical atherosclerosis among our cohort of PLWH. Despite having analyzed several HIV factors, age and smoking have been found to be the only factors associated with the development of atherosclerotic plaques.

Non-Coding RNA Involved in the Pathogenesis of Atherosclerosis-A Narrative Review.

Atherosclerosis is a highly prevalent condition associated with lipid accumulation in the intima layer of arterial blood vessels. The development of atherosclerotic plaques is associated with the incidence of major cardiovascular events, such as acute coronary syndrome or ischemic stroke. Due to the significant prevalence of atherosclerosis and its subclinical progression, it is associated with severe and potentially lethal complications. The pathogenesis of atherosclerosis is complex and not entirely known. The identification of novel non-invasive diagnostic markers and treatment methods that could suppress the progression of this condition is highly required. Non-coding RNA (ncRNA) involves several subclasses of RNA molecules. microRNA (miRNA), long non-coding RNA (lncRNA), and circular RNA (circRNA) differently regulate gene expression. Importantly, these molecules are frequently dysregulated under pathological conditions, which is associated with enhanced or suppressed expression of their target genes. In this review, we aim to discuss the involvement of ncRNA in crucial mechanisms implicated in the pathogenesis of atherosclerosis. We summarize current evidence on the potential use of these molecules as diagnostic and therapeutic targets.

A cross-sectional study comparing the expression of DNA repair molecules in subjects with and without atherosclerotic plaques.

Atherosclerosis, serving as the primary pathological mechanism at the core of cardiovascular disease, is now widely acknowledged to be associated with DNA damage and repair, contributing to atherosclerotic plaque formation. Therefore, molecules involved in the DNA repair process may play an important role in the progression of atherosclerosis. Our research endeavors to explore the contributions of specific and interrelated molecules involved in DNA repair (APE1, BRCA1, ERCC2, miR-221-3p, miR-145-5p, and miR-155-5p) to the development of atherosclerotic plaque and their interactions with each other. Gene expression study was conducted using the real-time polymerase chain reaction (qRT-PCR) method on samples from carotid artery atherosclerotic plaques and nonatherosclerotic internal mammary arteries obtained from 50 patients diagnosed with coronary artery disease and carotid artery disease. Additionally, 50 healthy controls were included for the determination of 8-hydroxy-2'-deoxyguanosine (8-OHdG). Although no difference was observed in mRNA gene expressions, we noted a decrease in miR-155-5p gene expression (p = 0.003) and an increase in miR-221-3p gene expression (p = 0.015) in plaque samples, while miR-145-5p gene expression remained unchanged (p = 0.57). Regarding serum 8-OHdG levels, patients exhibited significantly higher levels (1111.82 ± 28.64) compared to controls (636.23 ± 24.23) (p < 0.0001). In our study demonstrating the role of miR-155-5p and miR-221-3p in atherosclerosis, we propose that these molecules are potential biomarkers and therapeutic targets for coronary artery diseases and carotid artery disease.

Polystyrene nanoplastics accelerate atherosclerosis: Unraveling the impact on smooth muscle cells through KIF15-mediated migration

Microplastics and nanoplastics (MNPs) originating from plastic pollution pose potential threats to cardiovascular health, with prior studies linking MNPs to atherosclerosis. Our earlier research elucidated how nanoplastics enhance macrophages' phagocytic activity, leading to the formation of foam cells and an elevated risk of atherosclerosis. However, the specific influence of MNPs on smooth muscle cells (SMCs) in the context of MNP-induced atherosclerosis remains poorly understood. In this study, ApoE knockout (ApoE-/-) male mice with a high-fat diet were orally exposed to environmentally realistic concentrations of 2.5–250 mg/kg polystyrene nanoplastics (PS-NPs, 50 nm) for consecutive 19 weeks. Cardiovascular toxicity was comprehensively assessed through histopathological, transcriptomic, and proteomic analyses, while mechanisms underlying this toxicity were explored through in vitro studies. Herein, hematoxylin and eosin staining revealed accelerated atherosclerotic plaque development in ApoE-/- mice exposed to PS-NPs. Multi-omics analysis identified kinesin family member 15 (KIF15) as a pivotal target molecule. Both in vitro and in vivo experiments affirmed the specific upregulation of KIF15 in mouse aortic SMCs exposed to PS-NPs. Furthermore, in vitro experiments demonstrated that PS-NPs can promote the migration ability of MOVAS cells. Knockdown of Kif15 revealed its role in reducing MOVAS cell migration, with subsequent exposure to PS-NPs reversing the increased migration ability. This suggests that PS-NPs promote SMC migration by upregulating KIF15, and the migration of SMCs is closely associated with atherosclerosis outcomes. This study significantly advances our understanding of MNP-induced cardiovascular toxicity, providing valuable insights for risk assessment of human MNP exposure.

Cardiovascular Risk Estimation and Stratification Among Individuals with Hypercholesterolemia.

This review aims to assess the variability in considering hypercholesterolemia for cardiovascular risk stratification in the general population. Recent literature on the integration of hypercholesterolemia into clinical risk scores and its interaction with other risk factors will be explored. The impact of hypercholesterolemia on risk estimation varies among different cardiovascular risk calculators. Elevated lipid levels during early life stages contribute to atherosclerotic plaque development, influencing disease severity despite later treatment initiation. The interplay between low-density lipoprotein cholesterol (LDLc), inflammatory markers and non-LDL lipid parameters enhances cardiovascular risk stratification. Studies have also examined the role of coronary artery calcium (CAC) score as a negative risk marker in populations with severe hypercholesterolemia. Furthermore, polygenic risk scores (PRS) may aid in diagnosing non-monogenic hypercholesterolemia, refining cardiovascular risk stratification and guiding lipid-lowering therapy strategies. Understanding the heterogeneity in risk estimation and the role of emerging biomarkers and imaging techniques is crucial for optimizing cardiovascular risk prediction and guiding personalized treatment strategies in individuals with hypercholesterolemia.

Biomarkers That Seem to Have the Greatest Impact on Promoting the Formation of Atherosclerotic Plaque in Current Scientific Research.

Atherosclerosis is a chronic inflammatory disease that causes degenerative and productive changes in the arteries. The resulting atherosclerotic plaques restrict the vessel lumen, causing blood flow disturbances. Plaques are formed mainly in large- and medium-sized arteries, usually at bends and forks where there is turbulence in blood flow. Depending on their location, they can lead to various disease states such as myocardial infarction, stroke, renal failure, peripheral vascular diseases, or sudden cardiac death. In this work, we reviewed the literature on the early detection of atherosclerosis markers in the application of photodynamic therapy to atherosclerosis-related diseases. Herein, we described the roles of C-reactive protein, insulin, osteopontin, osteoprotegerin, copeptin, the TGF-β cytokine family, and the amino acid homocysteine. Also, we discuss the role of microelements such as iron, copper, zinc, and Vitamin D in promoting the formation of atherosclerotic plaque. Dysregulation of the administered compounds is associated with an increased risk of atherosclerosis. Additionally, taking into account the pathophysiology of atherosclerotic plaque formation, we believe that maintaining homeostasis in the range of biomarkers mentioned in this article is crucial for slowing down the process of atherosclerotic plaque development and the stability of plaque that is already formed.

CCN4 (WISP-1) reduces apoptosis and atherosclerotic plaque burden in an ApoE mouse model

Background and aimsCCN4/WISP-1 regulates various cell behaviours that contribute to atherosclerosis progression, including cell adhesion, migration, proliferation and survival. We therefore hypothesised that CCN4 regulates the development and progression of atherosclerotic plaques. MethodsWe used a high fat fed ApoE−/− mouse model to study atherosclerotic plaque progression in the brachiocephalic artery and aortic root. In protocol 1, male ApoE−/− mice with established plaques were given a CCN4 helper-dependent adenovirus to see the effect of treatment with CCN4, while in protocol 2 male CCN4−/−ApoE−/− were compared to CCN4+/+ApoE−/− mice to assess the effect of CCN4 deletion on plaque progression. ResultsCCN4 overexpression resulted in reduced occlusion of the brachiocephalic artery with less apoptosis, fewer macrophages, and attenuated lipid core size. The amount of plaque found on the aortic root was also reduced. CCN4 deficiency resulted in increased apoptosis and occlusion of the brachiocephalic artery as well as increased plaque in the aortic root. Additionally, in vitro cells from CCN4−/−ApoE−/− mice had higher apoptotic levels. CCN4 deficiency did not significantly affect blood cholesterol levels or circulating myeloid cell populations. ConclusionsWe conclude that in an atherosclerosis model the most important action of CCN4 is the effect on cell apoptosis. CCN4 provides pro-survival signals and leads to reduced cell death, lower macrophage number, smaller lipid core size and reduced atherosclerotic plaque burden. As such, the pro-survival effect of CCN4 is worthy of further investigation, in a bid to find a therapeutic for atherosclerosis.

Treatment with APAC, a dual antiplatelet anticoagulant heparin proteoglycan mimetic, limits early collar-induced carotid atherosclerotic plaque development in Apoe−/− mice

Background and aimsMast cell-derived heparin proteoglycans (HEP-PG) can be mimicked by bioconjugates carrying antithrombotic and anti-inflammatory properties. The dual antiplatelet and anticoagulant (APAC) construct administered, either locally or intravenously (i.v.), targets activated endothelium, its adhesion molecules, and subendothelial matrix proteins, all relevant to atherogenesis. We hypothesized that APAC influences cellular interactions in atherosclerotic lesion development and studied APAC treatment during the initiation and progression of experimental atherosclerosis. MethodsMale western-type diet-fed Apoe−/− mice were equipped with perivascular carotid artery collars to induce local atherosclerosis. In this model, mRNA expression of adhesion molecules including ICAM-1, VCAM-1, P-Selectin, and Platelet Factor 4 (PF4) are upregulated upon lesion development. From day 1 (prevention) or from 2.5 weeks after lesion initiation (treatment), mice were administered 0.2 mg/kg APAC i.v. or control vehicle three times weekly for 2.5 weeks. At week 5 after collar placement, mice were sacrificed, and lesion morphology was microscopically assessed. ResultsAPAC treatment did not affect body weight or plasma total cholesterol levels during the experiments. In the prevention setting, APAC reduced carotid artery plaque size and volume by over 50 %, aligning with decreased plaque macrophage area and collagen content. During the treatment setting, APAC reduced macrophage accumulation and necrotic core content, and improved markers of plaque stability. ConclusionsAPAC effectively reduced early atherosclerotic lesion development and improved markers of plaque inflammation in advanced atherosclerosis. Thus, APAC may have potential to alleviate the progression of atherosclerosis.

Examining the Relationship: Porphyromonas gingivalis Presence in Subgingival and Atherosclerotic Plaques of Cadavers

Background: Atherosclerosis and periodontitis are chronic inflammatory diseases characterized by inflammation and tissue destruction. Porphyromonas gingivalis, a key pathogen in periodontal disease, is implicated in initiating inflammation and tissue damage. Objectives: Given the potential link between periodontitis and the development of atherosclerotic plaques, this study aimed to investigate the presence of P. gingivalis DNA in subgingival and atherosclerotic plaques obtained from cadavers at the Tehran Forensic Medicine Center. Methods: In this cross-sectional study, cadavers with a postmortem interval of 6 hours and atherosclerotic plaques in their coronary arteries, along with subgingival plaques exhibiting pocket depths exceeding 5 mm, were examined. Subgingival plaque samples were collected from the deepest sites, while atherosclerotic plaque samples were harvested. Real-time PCR was employed to detect the presence of P. gingivalis in all samples, and the McNemar test was used for data analysis. Results: A total of 25 cadavers were included in the analysis, and both subgingival and atherosclerotic plaque samples were assessed. P. gingivalis DNA was identified in 40% of subgingival plaque samples and 16% of atherosclerotic plaque samples. Moreover, all positive atherosclerotic plaque samples also tested positive for P. gingivalis in the subgingival plaque. McNemar's analysis revealed a statistically significant difference between the subgingival and atherosclerotic samples (P-value = 0.03). Additionally, a correlation coefficient of 0.53 was obtained. Conclusions: While the study has certain limitations, the findings indicate a significant association between the presence of P. gingivalis in subgingival and coronary atherosclerotic plaques. Further investigations are warranted to elucidate the precise role of this periopathogen in atherosclerotic plaque formation.

An Unsupervised Learning Tool for Plaque Tissue Characterization in Histopathological Images.

Stroke is the second leading cause of death and a major cause of disability around the world, and the development of atherosclerotic plaques in the carotid arteries is generally considered the leading cause of severe cerebrovascular events. In recent years, new reports have reinforced the role of an accurate histopathological analysis of carotid plaques to perform the stratification of affected patients and proceed to the correct prevention of complications. This work proposes applying an unsupervised learning approach to analyze complex whole-slide images (WSIs) of atherosclerotic carotid plaques to allow a simple and fast examination of their most relevant features. All the code developed for the present analysis is freely available. The proposed method offers qualitative and quantitative tools to assist pathologists in examining the complexity of whole-slide images of carotid atherosclerotic plaques more effectively. Nevertheless, future studies using supervised methods should provide evidence of the correspondence between the clusters estimated using the proposed textural-based approach and the regions manually annotated by expert pathologists.

Adiponectin and Adiponectin Receptors in Atherosclerosis.

Adiponectin is an abundantly secreted hormone that communicates information between the adipose tissue, and the immune and cardiovascular systems. In metabolically healthy individuals, adiponectin is usually found at high levels and helps improve insulin responsiveness of peripheral tissues, glucose tolerance, and fatty acid oxidation. Beyond its metabolic functions in insulin-sensitive tissues, adiponectin plays a prominent role in attenuating the development of atherosclerotic plaques, partially through regulating macrophage-mediated responses. In this context, adiponectin binds to its receptors, adiponectin receptor 1 (AdipoR1) and AdipoR2 on the cell surface of macrophages to activate a downstream signaling cascade and induce specific atheroprotective functions. Notably, macrophages modulate the stability of the plaque through their ability to switch between pro-inflammatory responders, and anti-inflammatory pro-resolving mediators. Traditionally, the extremes of the macrophage polarization spectrum span from M1 pro-inflammatory and M2 anti-inflammatory phenotypes. Previous evidence has demonstrated that the adiponectin-AdipoR pathway influences M1-M2 macrophage polarization; adiponectin promotes a shift towards an M2-like state, whereas AdipoR1- and AdipoR2-specific contributions are more nuanced. To explore these concepts in depth, we discuss in this review the impact of adiponectin and AdipoR1/R2 on 1) metabolic and immune responses, and 2) M1-M2 macrophage polarization, including their ability to attenuate atherosclerotic plaque inflammation, and their potential as therapeutic targets for clinical applications.

Neutrophil extracellular traps mediate the crosstalk between plaque microenvironment and unstable carotid plaque formation

The development of unstable carotid atherosclerotic plaques is associated with the induction of neutrophil extracellular traps (NETs) via the activation of diverse inflammatory mediators in the circulating bloodstream. However, the underlying mechanisms through which NETs influence the microenvironment of atherosclerotic plaques and contribute to the development of unstable carotid plaques remain largely elusive. The objective of this study was to elucidate the role of myeloid differentiation protein 1 (MD-1, LY86)-induced NETs underlying the crosstalk between unstable plaque formation and the plaque microenvironment. We employed bioinformatics analysis to identify key genes associated with carotid-unstable plaque, followed by comprehensive validation using various experimental approaches on tissue specimens and plasma samples classified based on pathological characteristics. Patients with carotid-unstable plaques exhibited elevated plasma concentrations of MD-1 (LY86), while patients with stable plaques demonstrated comparatively lower levels. Furthermore, soluble MD-1 was found to induce the formation of NETs through activation of Toll-like receptor signaling pathway. The proliferative and immature vascularization effects of NETs on endothelial cells, as well as their inhibitory impact on cell migration, are directly correlated with the concentration of NETs. Additionally, NETs were found to activate the NF-κB signaling pathway, thereby upregulating ICAM1, VCAM1, MMP14, VEGFA, and IL6 expression in both Human umbilical vein endothelial cells (HUVECs) and HAECs. Subsequently, a significant increase in intraplaque neovascularization by NETs results in poor carotid plaque stability, and NETs in turn stimulate macrophages to produce more MD-1, generating a harmful positive feedback loop. Our findings suggest that soluble MD-1 in the bloodstream triggers the production of NETs through activation of the Toll-like receptor signaling pathway and further indicate NETs mediate a crosstalk between the microenvironment of the carotid plaque and the neovascularization of the intraplaque region. Inhibiting NETs formation or MD-1 secretion may represent a promising strategy to effectively suppress the development of unstable carotid plaques.

TAT-beclin1 treatment accelerates the development of atherosclerotic lesions in ApoE-deficient mice.

The importance of autophagy in atherosclerosis has garnered significant attention regarding the potential applications of autophagy inducers. However, the impact of TAT-Beclin1, a peptide inducer of autophagy, on the development of atherosclerotic plaques remains unclear. Single-cell omics analysis indicates a notable reduction in GAPR1 levels within fibroblasts, stromal cells, and macrophages during atherosclerosis. Tat-beclin1 (T-B), an autophagy-inducing peptide derived from Beclin1, could selectively bind to GAPR1, relieving its inhibition on Beclin1 and thereby augmenting autophagosome formation. To investigate its impact on atherosclerosic plaque progression, we established the ApoE-/- mouse model of carotid atherosclerotic plaques. Surprisingly, intravenous administration of Tat-beclin1 dramatically accelerated the development of carotid artery plaques. Immunofluorescence analysis suggested that macrophage aggregation and autophagosome formation within atherosclerotic plaques were significantly increased upon T-B treatment. However, immunofluorescence and transmission electron microscopy (TEM) analysis revealed a reduction in autophagy flux through lysosomes. Invitro, the interaction between T-B and GAPR1 was confirmed in RAW264.7 cells, resulting in the increased accumulation of p62/SQSTM1 and LC3-II in the presence of ox-LDL. Additionally, T-B treatment elevated the protein levels of p62/SQSTM1, LC3-II, and cleaved caspase 1, along with the secretion of IL-1β in response to ox-LDL exposure. In summary, our study underscores that T-B treatment amplifies abnormal autophagy and inflammation, consequently exacerbating atherosclerotic plaque development in ApoE-/- mice.

Effect of Diets with the Addition of Edible Insects on the Development of Atherosclerotic Lesions in ApoE/LDLR-/- Mice.

Foods enriched with insects can potentially prevent several health disorders, including cardiovascular diseases, by reducing inflammation and improving antioxidant status. In this study, Tenebrio molitor and Gryllus assimilis were selected to determine the effect on the development of atherosclerosis in ApoE/LDLR-/- mice. Animals were fed AIN-93G-based diets (control) with 10% Tenebrio molitor (TM) and 10% Gryllus assimilis (GA) for 8 weeks. The nutritional value as well as antioxidant activity of selected insects were determined. The lipid profile, liver enzyme activity, and the fatty acid composition of liver and adipose tissue of model mice were evaluated. Quantitative analysis of atherosclerotic lesions in the entire aorta was performed using the en face method, and for aortic roots, the cross-section method was used. The antioxidant status of the GA cricket was significantly higher compared to the TM larvae. The results showed that the area of atherosclerosis (en face method) was not significantly different between groups. Dietary GA reduced plaque formation in the aortic root; additionally, significant differences were observed in sections at 200 and 300 µm compared to other groups. Furthermore, liver enzyme ALT activity was lower in insect-fed groups compared to the control group. The finding suggests that a diet containing edible insect GA potentially prevents atherosclerotic plaque development in the aortic root, due to its high antioxidant activity.

Myeloperoxidase as a Promising Therapeutic Target after Myocardial Infarction.

Coronary artery disease (CAD) and myocardial infarction (MI) remain leading causes of death and disability worldwide. CAD begins with the formation of atherosclerotic plaques within the intimal layer of the coronary arteries, a process driven by persistent arterial inflammation and oxidation. Myeloperoxidase (MPO), a mammalian haem peroxidase enzyme primarily expressed within neutrophils and monocytes, has been increasingly recognised as a key pro-inflammatory and oxidative enzyme promoting the development of vulnerable coronary atherosclerotic plaques that are prone to rupture, and can precipitate a MI. Mounting evidence also implicates a pathogenic role for MPO in the inflammatory process that follows a MI, which is characterised by the rapid infiltration of activated neutrophils into the damaged myocardium and the release of MPO. Excessive and persistent cardiac inflammation impairs normal cardiac healing post-MI, resulting in adverse cardiac outcomes and poorer long-term cardiac function, and eventually heart failure. This review summarises the evidence for MPO as a significant oxidative enzyme contributing to the inappropriate inflammatory responses driving the progression of CAD and poor cardiac healing after a MI. It also details the proposed mechanisms underlying MPO's pathogenic actions and explores MPO as a novel therapeutic target for the treatment of unstable CAD and cardiac damage post-MI.

Emerging clinical role of proprotein convertase subtilisin/kexin type 9 inhibition-Part one: Pleiotropic pro-atherosclerotic effects of PCSK9.

Proprotein convertase subtilisin/kexin type 9 (PCSK9) is primarily recognized for its role in lipid metabolism, but recent evidence suggests that it may have broader implications due to its diverse tissue expression. This review aims to explore the multifaceted functions of PCSK9, highlighting its pro-atherosclerotic effects, including its impact on circulating lipoprotein variables, non-low-density lipoprotein receptors, and various cell types involved in atherosclerotic plaque development. PCSK9 exhibits diverse roles beyond lipid metabolism, potentially contributing to atherosclerosis through multiple pathways. Understanding these mechanisms could offer new insights into therapeutic strategies targeting PCSK9 for cardiovascular disease management.

Associations between lipoprotein(a), oxidized phospholipids, and extracoronary vascular disease

The roles of lipoprotein(a) [Lp(a)] and related oxidized phospholipids (OxPLs) in the development and progression of coronary disease is known, but their influence on extracoronary vascular disease is not well-established. We sought to evaluate associations between Lp(a), OxPL apolipoprotein B (OxPL-apoB), and apolipoprotein(a) (OxPL-apo(a)) with angiographic extracoronary vascular disease and incident major adverse limb events (MALEs). Four hundred forty-six participants who underwent coronary and/or peripheral angiography were followed up for a median of 3.7 years. Lp(a) and OxPLs were measured before angiography. Elevated Lp(a) was defined as ≥150 nmol/L. Elevated OxPL-apoB and OxPL-apo(a) were defined as greater than or equal to the 75th percentile (OxPL-apoB ≥8.2 nmol/L and OxPL-apo(a) ≥35.8 nmol/L, respectively). Elevated Lp(a) had a stronger association with the presence of extracoronary vascular disease compared to OxPLs and was minimally improved with the addition of OxPLs in multivariable models. Compared to participants with normal Lp(a) and OxPL concentrations, participants with elevated Lp(a) levels were twice as likely to experience a MALE (odds ratio: 2.14, 95% confidence interval: 1.03, 4.44), and the strength of the association as well as the C statistic of 0.82 was largely unchanged with the addition of OxPL-apoB and OxPL-apo(a). Elevated Lp(a) and OxPLs are risk factors for progression and complications of extracoronary vascular disease. However, the addition of OxPLs to Lp(a) does not provide additional information about risk of extracoronary vascular disease. Therefore, Lp(a) alone captures the risk profile of Lp(a), OxPL-apoB, and OxPL-apo(a) in the development and progression of atherosclerotic plaque in peripheral arteries.

Mechanism of Bile Acid in Regulating Platelet Function and Thrombotic Diseases.

Platelets play a key role in physiological hemostasis and pathological thrombosis. Based on the limitations of current antiplatelet drugs, it's important to elucidate the mechanisms of regulating platelet activation. In addition to dissolving lipid nutrients, bile acids (BAs) can regulate platelet function. However, the specific mechanisms underlying BAs-mediated effects on platelet activation and thrombotic diseases remain unknown. Therefore, the effects of BAs on platelets and intracellular regulatory mechanisms are explored. It is showed that the inhibitory effect of secondary BAs is more significant than that of primary BAs; lithocholic acid (LCA) shows the highest inhibitory effect. In the process of platelet activation, BAs suppress platelet activation via the spleen tyrosine kinase (SYK), protein kinase B (Akt), and extracellular signal-regulated kinase1/2 (Erk1/2) pathways. Nck adaptor proteins (NCK1) deficiency significantly suppress the activity of platelets and arterial thrombosis. Phosphorylated proteomics reveal that LCA inhibited phosphorylation of syntaxin-11 at S80/81 in platelets. Additional LCA supplementation attenuated atherosclerotic plaque development and reduced the inflammation in mice. In conclusion, BAs play key roles in platelet activation via Syk, Akt, ERK1/2, and syntaxin-11 pathways, which are associated with NCK1. The anti-platelet effects of BAs provide a theoretical basis for the prevention and therapy of thrombotic diseases.

Smooth muscle cell-specific deletion of S100A4 modifies smooth muscle cell fate and inflammation in murine atherosclerotic lesions

Abstract Funding Acknowledgements Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Swiss National Science Foundation (SNSF) S100A4, a calcium-binding protein, is crucial in smooth muscle cell (SMC) phenotypic switch, yet its role in atherosclerotic plaque development and SMC plasticity remains unclear. Our previous experiments using an S100A4 neutralizing antibody approach in ApoE-/- atherosclerotic-prone mice showed reduced atherosclerotic burden but did not establish a direct link between the various S100A4-expressing cells and atherosclerosis. Herein, we show that aortic Oil RedO staining in ApoE-/-; S100A4-/- mice subjected to a 12-week high-cholesterol-diet (HCD) revealed reduced lesion areas compared to ApoE-/- mice (Figure 1, from 21.29% of the total aorta in ApoE-/-; S100A4+/+ mice to 13.27% in ApoE-/-; S100A4-/- mice), highlighting a pivotal role for S100A4 in atherosclerotic plaque development. We then used a lineage tracing ApoE-/- mouse model, in which we induced an SMC-specific deletion of S100A4 (SMC-S100A4Δ/Δ). After 12 weeks of HCD, SMC-S100A4Δ/Δ and control mice (SMC-S100A4wt/wt) were sacrificed, and aortas were processed for en face Oil Red O staining, immunohistochemistry, and single-cell RNA sequencing (scRNA-seq). SMC-specific deletion of S100A4 reduced the necrotic core area (from 29.75% of total plaque area in SMC-S100A4wt/wt to 18.23% in SMC-S100A4Δ/Δ mice) without affecting total atherosclerotic plaque size suggesting a more potent impact on plaque composition. ScRNA-seq analysis from SMC-S100A4Δ/Δ and SMC-S100A4wt/wt mice showed that the inflammatory macrophage-like SMC phenotype was highly suppressed in the plaque and associated with increased SMC repair phenotypes as well as a global reduction of myeloid inflammatory cells. SMCs also retained specific contractile SMC markers, namely Acta2 and Myh11 (fold change of 2.285 and 2.492, respectively) hinting towards a more stable fibrous cap. Immunofluorescence staining on aortic roots plaque (Figure 2) confirmed those results with an increase of SMCs (from 11.02% to 16.18%) as well as a-smooth muscle actin (a-SMA, Acta2)-positive SMCs (from 3.25% to 5.1%) in SMC-S100A4 Δ/Δ mice. Furthermore, the Gene Set Enrichment Analysis (GSEA) of scRNAseq data revealed that, in SMC-S100A4Δ/Δ mice, genes related to mitochondrial metabolism and oxidative respiration were highly downregulated in all SMC clusters. We investigated SMC mitochondrial fitness in vitro and showed that S100A4-/- SMCs have an increased basal oxygen consumption rate and an increased proton leak (fold change of 1.37 and 1.96 respectively) suggestive of differences in cellular metabolic adaptability. In conclusion, our research emphasizes the significant role of S100A4 in plaque development, demonstrating how SMC-derived S100A4 knockdown affects plaque evolution, reducing inflammation, and promoting stability likely through influencing SMC phenotypic switch through metabolic pathways.