Stabilization of atherosclerotic plaques: new mechanisms and clinical targets

Does Periodontitis Increase the Risk for Future Cardiovascular Events? Long-Term Follow-Up of the PAROKRANK Study

BACKGROUND AND AIM

The study 'Periodontitis and Its Relation to Coronary Artery Disease' (PAROKRANK) reported an association between periodontitis (PD) and the first myocardial infarction (MI). This follow-up study aims to test the hypothesis that those with PD-compared to periodontally healthy individuals-are at increased risk for cardiovascular (CV) events and death.

METHODS

A total of 1587 participants (age <75 years; females 19%) had a dental examination including panoramic radiographs between 2010 and 2014. PD was categorized as healthy (≥80% alveolar bone height), mild/moderate (79%-66%) or severe (<66%). A composite CV event (first of all-cause death, non-fatal MI or stroke and hospitalization following to heart failure) was investigated during a mean follow-up period of 9.9 years (range 0.2-12.5 years). Participants were divided into two groups: those with and without PD. The primary event rate, stratified by periodontal status at baseline, was calculated using the Kaplan-Meier method and Cox regression.

RESULTS

The number of events was 187 in the 985 periodontally healthy participants (19%) and 174 in the 602 participants with PD (29%; p < 0.0001). Those with PD had a higher likelihood for a future event (hazard ratio [HR] = 1.26; 95% CI: 1.01-1.57; p = 0.038), following adjustment for age, smoking and diabetes.

CONCLUSION

The PAROKRANK follow-up revealed that CV events were more common among participants with PD, which supports the assumption that there might be a direct relation between PD and CV disease.

Impact of hypertension and arterial wall expansion on transport properties and atherosclerosis progression

This study explored the impact of hypertension on atheroma plaque formation through a mechanobiological model. The model incorporates blood flow via the Navier-Stokes equation. Plasma flow through the endothelium is determined by Darcy's law and the Kedem-Katchalsky equations, which consider the three-pore model utilized for substance flow across the endothelium. The behaviour of these substances within the arterial wall is described by convection-diffusion-reaction equations, while the arterial wall itself is modelled as a hyperelastic material using Yeoh's model. To accurately evaluate hypertension's influence, adjustments were made to incorporate wall compression-induced wall compaction by radial compression. This compaction impacts three key variables of the transport phenomena: diffusion, porosity, and permeability. Based on the obtained findings, we can conclude that hypertension significantly augments plaque growth, leading to an over 400% increase in plaque thickness. This effect persists regardless of whether wall mechanics are considered. Tortuosity, arterial wall permeability, and porosity have minimal impact on atheroma plaque growth under normal arterial pressure. However, the atheroma plaque growth changes dramatically in hypertensive cases. In such scenarios, the collective influence of all factors-tortuosity, permeability, and porosity-results in nearly a 20% increase in plaque growth. This emphasizes the importance of considering wall compression due to hypertension in patient studies, where elevated blood pressure and high cholesterol levels commonly coexist.

Endosomal Toll-Like Receptors intermediate negative impacts of viral diseases, autoimmune diseases, and inflammatory immune responses on the cardiovascular system

INTRODUCTION

Cardiovascular disease (CVD) is the leading cause of morbidity globally, with chronic inflammation as a key modifiable risk factor. Toll-like receptors (TLRs), pivotal components of the innate immune system, including TLR-3, -7, -8, and -9 within endosomes, trigger intracellular cascades, leading to inflammatory cytokine production by various cell types, contributing to systemic inflammation and atherosclerosis. Recent research highlights the role of endosomal TLRs in recognizing self-derived nucleic acids during sterile inflammation, implicated in autoimmune conditions like myocarditis.

AREAS COVERED

This review explores the impact of endosomal TLRs on viral infections, autoimmunity, and inflammatory responses, shedding light on their intricate involvement in cardiovascular health and disease by examining literature on TLR-mediated mechanisms and their roles in CVD pathophysiology.

EXPERT OPINION

Removal of endosomal TLRs mitigates myocardial damage and immune reactions, applicable in myocardial injury. Targeting TLRs with agonists enhances innate immunity against fatal viruses, lowering viral loads and mortality. Prophylactic TLR agonist administration upregulates TLRs, protecting against fatal viruses and improving survival. TLRs play a complex role in CVDs like atherosclerosis and myocarditis, with therapeutic potential in modulating TLR reactions for cardiovascular health.

A novel mechanism of ferroptosis inhibition-enhanced atherosclerotic plaque stability: YAP1 suppresses vascular smooth muscle cell ferroptosis through GLS1

Atherosclerosis is a leading cause of cardiovascular diseases (CVDs), often resulting in major adverse cardiovascular events (MACEs), such as myocardial infarction and stroke due to the rupture or erosion of vulnerable plaques. Ferroptosis, an iron-dependent form of cell death, has been implicated in the development of atherosclerosis. Despite its involvement in CVDs, the specific role of ferroptosis in atherosclerotic plaque stability remains unclear. In this study, we confirmed the presence of ferroptosis in unstable atherosclerotic plaques and demonstrated that the ferroptosis inhibitor ferrostatin-1 (Fer-1) stabilizes atherosclerotic plaques in apolipoprotein E knockout (Apoe-/-) mice. Using bioinformatic analysis combining RNA sequencing (RNA-seq) with single-cell RNA sequencing (scRNA-seq), we identified Yes-associated protein 1 (YAP1) as a potential key regulator of ferroptosis in vascular smooth muscle cells (VSMCs) of unstable plaques. In vitro, we found that YAP1 protects against oxidized low-density lipoprotein (oxLDL)-induced ferroptosis in VSMCs. Mechanistically, YAP1 exerts its anti-ferroptosis effects by regulating the expression of glutaminase 1 (GLS1) to promote the synthesis of glutamate (Glu) and glutathione (GSH). These findings establish a novel mechanism where the inhibition of ferroptosis promotes the stabilization of atherosclerotic plaques through the YAP1/GLS1 axis, attenuating VSMC ferroptosis. Thus, targeting the YAP1/GLS1 axis to suppress VSMC ferroptosis may represent a novel strategy for preventing and treating unstable atherosclerotic plaques.

Lipids associated with atherosclerotic plaque instability revealed by mass spectrometry imaging of human carotid arteries

BACKGROUND AND AIMS

Lipids constitute one of the main components of atherosclerosis lesions and are the mediators of many mechanisms involved in plaque progression and stability. Here we tested the hypothesis that lipids known to be involved in plaque development exhibited associations with plaque vulnerability. We used spatial lipidomics to overcome plaque heterogeneity and to compare lipids from specific regions of symptomatic and asymptomatic human carotid atherosclerotic plaques.

METHODS

Carotid atherosclerotic plaques were collected from symptomatic and asymptomatic patients. Plaque lipids were analyzed with the spatial lipidomics technique matrix-assisted laser desorption/ionization mass spectrometry imaging, and histology and immunofluorescence were used to segment the plaques into histomolecularly distinct regions.

RESULTS

Macrophage-rich regions from symptomatic lesions were found to be enriched in phosphatidylcholines (synthesized to counteract excess free cholesterol), while the same region from asymptomatic plaques were enriched in polyunsaturated cholesteryl esters and triglycerides, characteristic of functional lipid droplets. Vascular smooth muscle cells (VSMCs) of the fibrous cap of asymptomatic plaques were enriched in lysophosphatidylcholines and cholesteryl esters, know to promote VSMC proliferation and migration, crucial for the buildup of the fibrous cap stabilizing the plaque.

CONCLUSIONS

The investigation of the region-specific lipid composition of symptomatic and asymptomatic human atherosclerotic plaques revealed specific lipid markers of plaque outcome, which could be linked to known biological characteristics of stable plaques.

β-Carotene accelerates the resolution of atherosclerosis in mice

β-Carotene oxygenase 1 (BCO1) catalyzes the cleavage of β-carotene to form vitamin A. Besides its role in vision, vitamin A regulates the expression of genes involved in lipid metabolism and immune cell differentiation. BCO1 activity is associated with the reduction of plasma cholesterol in humans and mice, while dietary β-carotene reduces hepatic lipid secretion and delays atherosclerosis progression in various experimental models. Here we show that β-carotene also accelerates atherosclerosis resolution in two independent murine models, independently of changes in body weight gain or plasma lipid profile. Experiments in Bco1-/- mice implicate vitamin A production in the effects of β-carotene on atherosclerosis resolution. To explore the direct implication of dietary β-carotene on regulatory T cells (Tregs) differentiation, we utilized anti-CD25 monoclonal antibody infusions. Our data show that β-carotene favors Treg expansion in the plaque, and that the partial inhibition of Tregs mitigates the effect of β-carotene on atherosclerosis resolution. Our data highlight the potential of β-carotene and BCO1 activity in the resolution of atherosclerotic cardiovascular disease.

β-carotene accelerates the resolution of atherosclerosis in mice

β-carotene oxygenase 1 (BCO1) catalyzes the cleavage of β-carotene to form vitamin A. Besides its role in vision, vitamin A regulates the expression of genes involved in lipid metabolism and immune cell differentiation. BCO1 activity is associated with the reduction of plasma cholesterol in humans and mice, while dietary β-carotene reduces hepatic lipid secretion and delays atherosclerosis progression in various experimental models. Here we show that β-carotene also accelerates atherosclerosis resolution in two independent murine models, independently of changes in body weight gain or plasma lipid profile. Experiments in Bco1-/- mice implicate vitamin A production in the effects of β-carotene on atherosclerosis resolution. To explore the direct implication of dietary β-carotene on regulatory T cells (Tregs) differentiation, we utilized anti-CD25 monoclonal antibody infusions. Our data show that β-carotene favors Treg expansion in the plaque, and that the partial inhibition of Tregs mitigates the effect of β-carotene on atherosclerosis resolution. Our data highlight the potential of β-carotene and BCO1 activity in the resolution of atherosclerotic cardiovascular disease.

Extracellular vesicles stimulate smooth muscle cell migration by presenting collagen VI

The extracellular matrix (ECM) supports blood vessel architecture and functionality and undergoes active remodelling during vascular repair and atherogenesis. Vascular smooth muscle cells (VSMCs) are essential for vessel repair and, via their secretome, are able to invade from the vessel media into the intima to mediate ECM remodelling. Accumulation of fibronectin (FN) is a hallmark of early vascular repair and atherosclerosis and here we show that FN stimulates VSMCs to secrete small extracellular vesicles (sEVs) by activating the β1 integrin/FAK/Src pathway as well as Arp2/3-dependent branching of the actin cytoskeleton. Spatially, sEV were secreted via filopodia-like cellular protrusions at the leading edge of migrating cells. We found that sEVs are trapped by the ECM in vitro and colocalise with FN in symptomatic atherosclerotic plaques in vivo. Functionally, ECM-trapped sEVs induced the formation of focal adhesions (FA) with enhanced pulling forces at the cellular periphery. Proteomic and GO pathway analysis revealed that VSMC-derived sEVs display a cell adhesion signature and are specifically enriched with collagen VI. In vitro assays identified collagen VI as playing the key role in cell adhesion and invasion. Taken together our data suggests that the accumulation of FN is a key early event in vessel repair acting to promote secretion of collage VI enriched sEVs by VSMCs. These sEVs stimulate migration and invasion by triggering peripheral focal adhesion formation and actomyosin contraction to exert sufficient traction forces to enable VSMC movement within the complex vascular ECM network.

Hypofucosylation of Unc5b regulated by Fut8 enhances macrophage emigration and prevents atherosclerosis

BACKGROUND

Atherosclerosis (AS) is the leading underlying cause of the majority of clinical cardiovascular events. Retention of foamy macrophages in plaques is the main factor initiating and promoting the atherosclerotic process. Our previous work showed that ox-LDL induced macrophage retention in plaques and that the guidance receptor Uncoordinated-5 homolog B (Unc5b) was involved in this process. However, little is known about the role of Unc5b in regulating macrophage accumulation within plaques.

RESULTS

In the present study, we found that Unc5b controls macrophage migration and thus promotes plaque progression in ApoE^-/- mice. The immunofluorescence colocalization assay results first suggested that fucosyltransferase 8 (Fut8) might participate in the exacerbation of atherosclerosis. Animals with Unc5b overexpression showed elevated levels of Fut8 and numbers of macrophages and an increased lesion size and intimal thickness. However, these effects were reversed in ApoE^-/- mice with Unc5b knockdown. Furthermore, Raw264.7 macrophages with siRNA-mediated silencing of Unc5b or overexpression of Unc5b were used to confirm the regulatory mechanisms of Unc5b and Fut8 in vitro. In response to ox-LDL exposure, Unc5b and Fut8 were both upregulated, and macrophages showed reduced pseudopod formation and migratory capacities. However, these capacities were restored by blocking Unc5b or Fut8. Furthermore, the IP assay indicated that Fut8 regulated the level of α-1,6 fucosylation of Unc5b, which mainly occurs in the endoplasmic reticulum (ER), and genetic deletion of the main fucosylation sites or Fut8 resulted in hypofucosylation of Unc5b. Moreover, the macrophage migration mediated by Unc5b depended on inactivation of the p-CDC42/p-PAK pathway. Conversely, macrophages with Unc5b overexpression displayed activation of the p-CDC42/p-PAK pathway and decreased migration both in vivo and in vitro.

CONCLUSION

These results demonstrated that hypofucosylation of Unc5b regulated by Fut8 is positively associated with the delay of the atherosclerotic process by promoting the migration of foamy macrophages. These findings identify a promising therapeutic target for atherosclerosis.

Smooth muscle cell fate decisions decipher a high-resolution heterogeneity within atherosclerosis molecular subtypes

BACKGROUND

Mounting evidence has revealed the dynamic variations in the cellular status and phenotype of the smooth muscle cell (SMC) are vital for shaping the atherosclerotic plaque microenvironment and ultimately mapping onto heterogeneous clinical outcomes in coronary artery disease. Currently, the underlying clinical significance of SMC evolutions remains unexplored in atherosclerosis.

METHODS

The dissociated cells from diseased segments within the right coronary artery of four cardiac transplant recipients and 1070 bulk samples with atherosclerosis from six bulk cohorts were retrieved. Following the SMC fate trajectory reconstruction, the MOVICS algorithm integrating the nearest template prediction was used to develop a stable and robust molecular classification. Subsequently, multi-dimensional potential biological implications, molecular features, and cell landscape heterogeneity among distinct clusters were decoded.

RESULTS

We proposed an SMC cell fate decision signature (SCFDS)-based atherosclerosis stratification system and identified three SCFDS subtypes (C1-C3) with distinguishing features: (i) C1 (DNA-damage repair type), elevated base excision repair (BER), DNA replication, as well as oxidative phosphorylation status. (ii) C2 (immune-activated type), stronger immune activation, hyper-inflammatory state, the complex as well as varied lesion microenvironment, advanced stage, the most severe degree of coronary stenosis severity. (iii) C3 (stromal-rich type), abundant fibrous content, stronger ECM metabolism, immune-suppressed microenvironment.

CONCLUSIONS

This study uncovered atherosclerosis complex cellular heterogeneity and a differentiated hierarchy of cell populations underlying SMC. The novel high-resolution stratification system could improve clinical outcomes and facilitate individualized management.

How vascular smooth muscle cell phenotype switching contributes to vascular disease

Vascular smooth muscle cells (VSMCs) are the most abundant cell in vessels. Earlier experiments have found that VSMCs possess high plasticity. Vascular injury stimulates VSMCs to switch into a dedifferentiated type, also known as synthetic VSMCs, with a high migration and proliferation capacity for repairing vascular injury. In recent years, largely owing to rapid technological advances in single-cell sequencing and cell-lineage tracing techniques, multiple VSMCs phenotypes have been uncovered in vascular aging, atherosclerosis (AS), aortic aneurysm (AA), etc. These VSMCs all down-regulate contractile proteins such as α-SMA and calponin1, and obtain specific markers and similar cellular functions of osteoblast, fibroblast, macrophage, and mesenchymal cells. This highly plastic phenotype transformation is regulated by a complex network consisting of circulating plasma substances, transcription factors, growth factors, inflammatory factors, non-coding RNAs, integrin family, and Notch pathway. This review focuses on phenotypic characteristics, molecular profile and the functional role of VSMCs phenotype landscape; the molecular mechanism regulating VSMCs phenotype switching; and the contribution of VSMCs phenotype switching to vascular aging, AS, and AA. Video Abstract.

Critical Role of Inflammation and Specialized Pro-Resolving Mediators in the Pathogenesis of Atherosclerosis

Recent research on how the body resolves this inflammation is gaining traction and has shed light on new avenues for future management of cardiovascular diseases. In this narrative review, we discuss the pathophysiological mechanisms of atherosclerosis, the recent development in the understanding of a new class of molecules called Specialized Pro-resolving Mediators (SPMs), and the impact of such findings in the realm of cardiovascular treatment options. We searched the MEDLINE database restricting ourselves to original research articles as much as possible on the complex pathophysiology of atherosclerosis and the role of SPMs. We expect to see further research in translating these findings to bedside clinical trials in treating conditions with a pathophysiological basis of inflammation, such as coronary artery disease, asthma, and periodontal disease.

Dynamic coronary CT Angiography-Estimated coronary flow in Non-Obstructive, Plaque-free coronary Arteries: Association with dyslipidemia and diabetes

Rationale and Objectives

In this study, we implemented dynamic coronary CT angiography (CCTA) in order to estimate the coronary flow rate in morphologically normal coronary arteries as well as to identify factors affecting the coronary flow rate.

Materials and Methods

We retrospectively enrolled 95 consecutively presenting patients without stenosis or plaque in their major coronary arteries on CCTA conducted with a 320-detector scanner (mean age, 57 years; 43 % men). Time-attenuation curves of the distal sites of the major coronary arteries and the aortic root were extracted from dynamic CCTA data. Coronary flow rate, an indicator of coronary blood flow, was calculated via a convolution-integration method integrating the two curves. Patients with dyslipidemia were divided according to the presence or absence of familial hypercholesterolemia (FH) as well as according to the receipt of statin therapy.

Results

We found that the coronary flow rate was statistically significantly lower in statin-naïve patients with dyslipidemia (n = 27, 0.56 ± 0.10) than in patients without dyslipidemia (n = 32, 0.64 ± 0.10, p = 0.0013). In FH (n = 26), the coronary flow rate was statistically significantly lower in statin-naïve patients (n = 7, 0.65 ± 0.08) than in those taking statins (n = 19, 0.72 ± 0.10, p = 0.0221). Coronary flow rate likewise exhibited a statistically significant negative correlation with hemoglobin A1c (Pearson r, −0.437; p = 0.0003), but no correlation with other coronary risk factors. The coronary flow rate was statistically significantly lower in patients with diabetes (n = 14, 0.55 ± 0.10) than in those without diabetes (n = 81, 0.61 ± 0.11, p = 0.0461).

Conclusion

We found a reduction in coronary flow rate in patients with statin-naive dyslipidemia and diabetes, even within morphologically normal coronary arteries.

Distinct role of mitochondrial function and protein kinase C in intimal and medial calcification in vitro

Introduction

Vascular calcification (VC) is a major risk factor for cardiovascular morbidity and mortality. Depending on the location of mineral deposition within the arterial wall, VC is classified as intimal and medial calcification. Using in vitro mineralization assays, we developed protocols triggering both types of calcification in vascular smooth muscle cells (SMCs) following diverging molecular pathways.

Materials and methods and results

Human coronary artery SMCs were cultured in osteogenic medium (OM) or high calcium phosphate medium (CaP) to induce a mineralized extracellular matrix. OM induces osteoblast-like differentiation of SMCs-a key process in intimal calcification during atherosclerotic plaque remodeling. CaP mimics hyperphosphatemia, associated with chronic kidney disease-a risk factor for medial calcification. Transcriptomic analysis revealed distinct gene expression profiles of OM and CaP-calcifying SMCs. OM and CaP-treated SMCs shared 107 differentially regulated genes related to SMC contraction and metabolism. Real-time extracellular efflux analysis demonstrated decreased mitochondrial respiration and glycolysis in CaP-treated SMCs compared to increased mitochondrial respiration without altered glycolysis in OM-treated SMCs. Subsequent kinome and in silico drug repurposing analysis (Connectivity Map) suggested a distinct role of protein kinase C (PKC). In vitro validation experiments demonstrated that the PKC activators prostratin and ingenol reduced calcification triggered by OM and promoted calcification triggered by CaP.

Conclusion

Our direct comparison results of two in vitro calcification models strengthen previous observations of distinct intracellular mechanisms that trigger OM and CaP-induced SMC calcification in vitro. We found a differential role of PKC in OM and CaP-calcified SMCs providing new potential cellular and molecular targets for pharmacological intervention in VC. Our data suggest that the field should limit the generalization of results found in in vitro studies using different calcification protocols.

Matrix Metalloproteinases: From Molecular Mechanisms to Physiology, Pathophysiology, and Pharmacology

The first matrix metalloproteinase (MMP) was discovered in 1962 from the tail of a tadpole by its ability to degrade collagen. As their name suggests, matrix metalloproteinases are proteases capable of remodeling the extracellular matrix. More recently, MMPs have been demonstrated to play numerous additional biologic roles in cell signaling, immune regulation, and transcriptional control, all of which are unrelated to the degradation of the extracellular matrix. In this review, we will present milestones and major discoveries of MMP research, including various clinical trials for the use of MMP inhibitors. We will discuss the reasons behind the failures of most MMP inhibitors for the treatment of cancer and inflammatory diseases. There are still misconceptions about the pathophysiological roles of MMPs and the best strategies to inhibit their detrimental functions. This review aims to discuss MMPs in preclinical models and human pathologies. We will discuss new biochemical tools to track their proteolytic activity in vivo and ex vivo, in addition to future pharmacological alternatives to inhibit their detrimental functions in diseases. SIGNIFICANCE STATEMENT: Matrix metalloproteinases (MMPs) have been implicated in most inflammatory, autoimmune, cancers, and pathogen-mediated diseases. Initially overlooked, MMP contributions can be both beneficial and detrimental in disease progression and resolution. Thousands of MMP substrates have been suggested, and a few hundred have been validated. After more than 60 years of MMP research, there remain intriguing enigmas to solve regarding their biological functions in diseases.

Recent advances in the development of active hybrid molecules in the treatment of cardiovascular diseases

Multifactorial nature of the underlying pathophysiology of chronic disorders hinders in the effective treatment and management of many complex diseases. The conventional targeted therapies have limited applications due to highly complicated disease etiology. Cardiovascular diseases (CVDs) are the group of disorders of the heart and blood vessels. Currently, there is limited knowledge on the underlying cellular and molecular mechanisms of many of the CVDs due to their complex pathophysiology and co-morbidities. Their management with conventional medications results in failure due to adverse drug reactions and clinical specificity of solo-targeting drug therapy. Therefore, it is critical to introduce an alternative strategy to treat multi-factorial diseases. In the past few years, discovery and use of multi-targeted drug therapy with hybrid molecules have shown promising results with minimal side effects, and thus considered a most effective approach. In this review article, prominent hybrid molecules combining with different active moieties are reported to synergistically and simultaneously block different pathways involved in CVDs. Here, we provide a critical evaluation and discussion on their pharmacology with mechanistic insights and the structure activity relationship. The timely information provided in this article reveals the recent trends of molecular hybridization to the scientific community interested in CVDs and help them in designing the next generation of multi-targeting drug therapeutics.

Assessment of Serum Parameters in Stable Coronary Artery Disease Patients in Correlation with Healthy and Chronic Periodontitis Patients

Background

Periodontitis is a chronic inflammatory disease and has been strongly associated with elevation of systemic markers such as C-reactive protein (CRP), fibrinogen (FIB), and lipid profile, which have also been significantly associated with coronary heart disease (CHD). Hence, there is a need to assess the possible association between chronic periodontitis and coronary artery disease.

Materials and Methods

A study included 100 subjects divided into four groups. Group I: stable coronary artery disease with chronic periodontitis, Group II: stable coronary artery disease without chronic periodontitis, Group III: chronic periodontitis without coronary artery disease, and Group IV: healthy controls. Gingival index, Russell's periodontal index, pocket depth, and clinical attachment level were recorded. Venous blood was collected from the patients, and serum fibrinogen, CRP, and lipid profile levels were estimated.

Results

The intragroup comparison of biochemical and periodontal parameters showed statistically significant results with P < 0.05. The intergroup comparison of serum FIB, total cholesterol, high density lipoprotein, low density lipoprotein, and clinical attachment level showed statistical significant results (P = 0.000, P = 0.000, P = 0.001, P = 0.025, and P = 0.000, respectively) between Groups I and III.

Conclusion

The results of the study indicate that there might a possible correlation between coronary artery disease and chronic periodontitis, but periodontitis-cardiovascular link is complex and difficult to define though there is sufficient evidence for their association. Leakage of pro-inflammatory cytokines from the ulcerated periodontium causes the production of acute-phase proteins by the liver. To prove the relationship, further studies should be considered making use of other markers of inflammation with prospective randomized controlled studies involving large population.

Assessment of Therapeutic Response to Statin Therapy in Patients With Intracranial or Extracranial Carotid Atherosclerosis by Vessel Wall MRI: A Systematic Review and Updated Meta-Analysis

Background and Aims: Statin therapy is an essential component of cardiovascular preventive care. In recent years, various vessel wall MRI (VW-MRI) techniques have been used to monitor atherosclerosis progression or regression in patients with extracranial or intracranial large-artery atherosclerosis. We aimed to perform a systematic review and meta-analysis on the effects of statin therapy on plaque evolution as assessed by VW-MRI.

Materials and Methods: Prospective studies investigating carotid and intracranial atherosclerotic plaques in patients on statin therapy monitored by serial VW-MRI were systematically identified in the literature. The plaque burden and lipid-rich necrotic core (LRNC) volume of carotid plaque and the imaging features of intracranial plaques were extracted and summarized. For studies investigating carotid artery wall volume and LRNC volume, combined estimates were derived by meta-analysis.

Results: The study identified 21 studies of carotid plaque and two studies of intracranial plaque. While 16 studies investigating carotid plaques that included 780 patients by High-resolution VW-MRI were included in the meta-analysis. There was no significant change in carotid wall volume from baseline to 12 months. A significant change in LRNC volume was observed at > 12 months compared with baseline (Effect = −10.69, 95% CI = −19.11, −2.28, P < 0.01), while no significant change in LRNC volume at 3–6 months or 7–12 months after statin therapy initiation in 6 studies. Increases in fibrous tissue and calcium and reduction in neovascularization density of the plaque were seen in 2/3 studies (including 48/59 patients), 1/3 studies (including 17/54 patients), and 2/2 studies (including 71 patients) after statin therapy, respectively. Two studies with 257 patients in intracranial atherosclerosis showed that statins could effectively decrease wall volume and plaque enhancement volume.

Conclusions: Collective data indicated that statins could potentially stabilize carotid plaques by significantly reducing LRNC with 1 year of therapy as shown on serial carotid VW-MRI. There was no significant decrease in wall volume, which nonetheless indicated that plaque composition changes might be more sensitive to response monitoring than wall volume. It is likely that more sensitive, clinically relevant, and preferably quantitative indicators of therapeutic effects on intracranial vessel plaque morphology will be developed in the future.

Exosomes and Atherogenesis

Myocardial infarction and ischemic stroke are the leading causes of mortality worldwide. Atherosclerosis is their common pathological foundation. It is known that atherosclerosis is characterized by endothelial activation/injury, accumulation of inflammatory immune cells and lipid-rich foam cells, followed by the development of atherosclerotic plaque. Either from arterial vessel wall or blood circulation, endothelial cells, smooth muscle cells, macrophages, T-lymphocytes, B-lymphocytes, foam cells, and platelets have been considered to contribute to the pathogenesis of atherosclerosis. Exosomes, as natural nano-carriers and intercellular messengers, play a significant role in modulation of cell-to-cell communication. Under physiological or pathological conditions, exosomes can deliver their cargos including donor cell-specific proteins, lipids, and nucleic acids to target cells, which in turn affect the function of the target cells. In this review, we will describe the pathophysiological significance of various exosomes derived from different cell types associated with atherosclerosis, and the potential applications of exosome in clinical diagnosis and treatment.

Nrf2 and Heme Oxygenase-1 Involvement in Atherosclerosis Related Oxidative Stress

Atherosclerosis remains the underlying process responsible for cardiovascular diseases and the high mortality rates associated. This chronic inflammatory disease progresses with the formation of occlusive atherosclerotic plaques over the inner walls of vascular vessels, with oxidative stress being an important element of this pathology. Oxidation of low-density lipoproteins (ox-LDL) induces endothelial dysfunction, foam cell activation, and inflammatory response, resulting in the formation of fatty streaks in the atherosclerotic wall. With this in mind, different approaches aim to reduce oxidative damage as a strategy to tackle the progression of atherosclerosis. Special attention has been paid in recent years to the transcription factor Nrf2 and its downstream-regulated protein heme oxygenase-1 (HO-1), both known to provide protection against atherosclerotic injury. In the current review, we summarize the involvement of oxidative stress in atherosclerosis, focusing on the role that these antioxidant molecules exert, as well as the potential therapeutic strategies applied to enhance their antioxidant and antiatherogenic properties.

Discerning the promising binding sites of S100/calgranulins and their therapeutic potential in atherosclerosis

INTRODUCTION

Atherosclerosis is a chronic inflammatory disease in which the members of S100 family proteins (calgranulins) bind with their receptors, particularly receptor for advanced glycation end products (RAGE) and toll-like receptor-4 (TLR-4) and play a key role in the pathogenesis and progression of disease. Thus, these proteins could be considered as potential biomarkers and therapeutic targets in the treatment of atherosclerotic inflammation.

AREAS COVERED

This review summarizes the pathology of S100A8, S100A9, and S100A12 in the development of atherosclerosis and reveals key structural features of these proteins which are potentially critical in their pathological effects. This article focuses on the translational significance of antagonizing these proteins by using small molecules in patent literature, clinical and preclinical studies and also discusses future approaches that could be employed to block these proteins in the treatment of atherosclerosis.

EXPERT OPINION

Based on the critical role of S100/calgranulins in the regulation of atherosclerosis, these proteins are potential targets to develop better therapeutic options in the treatment of inflammatory diseases. However, further research is still needed to clarify their exact molecular mechanism by analyzing their detailed structural features that can expedite future research to develop novel therapeutics against these proteins to treat atherosclerotic inflammation.

Theranostics of atherosclerosis by the indole molecule-templated self-assembly of probucol nanoparticles

Atherosclerosis (AS) is a major cause of cardiovascular diseases, but its effective theranostic measure remains challenging thus far. Macrophages contribute to AS progress in diverse ways such as producing cytokines and reactive oxygen species (ROS), foaming macrophages, and differentiating into pro-inflammatory macrophages. With the aim of constructing a facile and efficacious theranostic system for diagnosis and treatment of AS, a templated self-assembly approach was developed. This strategy involves using indole molecule (indocyanine green (ICG) or IR783) as a template to assemble with probucol (PB) to gain multifunctional nanoparticles (IPNPs or IRPNPs). IPNPs and IRPNPs both showed excellent physicochemical properties, which testified the generality of the indole molecular self-assembly strategy for PB delivery. Besides, the nanoparticles have superior pharmaceutical characteristics including preventing macrophages from differentiating, more efficiently internalizing in inflammatory macrophages, eliminating overproduced ROS, lowering the level of inflammation cytokines, and inhibiting foaming. More importantly, IPNPs displayed effective therapeutic effects in AS model mice when administered via intravenous (i.v.) route. In addition, IPNPs and IRPNPs accumulated more effectively than ICG and IR783 via i.v. injection in the lesion area, and the blood circulation time was extended beyond 24 h. More interestingly, we discovered that the fluorescence imaging ability of IR783 and IRPNPs was more excellent than ICG and IPNPs, respectively. Moreover, a long-term treatment with IPNPs or IRPNPs revealed an excellent safety profile in mice. Accordingly, this self-assembly strategy developed herein is a universal and promising way for the delivery of lipophilic drugs. This study also provides new insights into developing effective theranostic agents for AS.

Carotid Artery Atherosclerotic Profile as Risk Predictor for Restenosis After Coronary Stenting

BACKGROUND

The incidence of restenosis of the coronary artery after a bare-metal stent implant has been lower than in simple balloon angioplasty; however, it still shows relatively high rates.

OBJECTIVE

The aim of this study was to find new risk indicators for in-stent restenosis using carotid ultrasonography, that, in addition to the already existing indicators, would help in decision-making for stent selection.

METHODS

We carried out a cross-sectional prospective study including 121 consecutive patients with chronic coronary artery disease who had undergone percutaneous coronary intervention with repeat angiography in the previous 12 months. After all cases of in-stent restenosis were identified, patients underwent carotid ultrasonography to evaluate carotid intima-media thickness and atherosclerosis plaques. The data were analyzed by Cox multiple regression. The significance level was set a p<0.05.

RESULTS

Median age of patients was 60 years (1st quartile = 55, 3rd quartile = 68), and 64.5% of patients were male. Coronary angiography showed that 57 patients (47.1%) presented in-stent restenosis. Fifty-five patients (45.5%) had echolucent atherosclerotic plaques in carotid arteries and 54.5% had echogenic plaques or no plaques. Of patients with who had echolucent plaques, 90.9% presented coronary in-stent restenosis. Of those who had echogenic plaques or no plaques, 10.6% presented in-stent restenosis. The presence of echolucent plaques in carotid arteries increased the risk of coronary in-stent restenosis by 8.21 times (RR=8.21; 95%CI: 3.58-18.82; p<0.001).

CONCLUSIONS

The presence of echolucent atherosclerotic plaques in carotid artery constitutes a risk predictor of coronary instent restenosis and should be considered in the selection of the type of stent to be used in coronary angioplasty.

The expression profile of platelet-derived miRNA in coronary artery disease patients with clopidogrel resistance

Clopidogrel is widely used for antiplatelet therapy in patients with coronary artery disease (CAD), but clopidogrel resistance (CR) is relatively common in these patients. The goal of our study was to explore the platelet-derived miRNA expression profile of CR in CAD patients. In this study, 66 CAD patients treated with dual antiplatelet therapy (clopidogrel 75 mg once daily plus aspirin 100 mg once daily) were included. According to inhibition of platelet aggregation (IPA), we divided these patients into CR group (IPA <30%) and control group (IPA ≥30%). The concentrations of clopidogrel and clopidogrel active metabolites in plasma were obtained using UHPLC-Q-Orbitrap HRMS method. The platelet-derived miRNA expression profiles of these subjects were detected by high-throughput sequencing and qRT-PCR. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) were used for function prediction of differentially expressed miRNAs. Our results suggested no significant difference of clopidogrel and active metabolic derivative concentrations between CR group and control group. Correlation analysis showed no significant association between clopidogrel concentration and IPA; active metabolic derivative and IPA. In addition, 67 platelet-derived miRNAs were differentially expressed between three CR and three control patients. After adjusting, eight miRNAs might be related to CR in CAD. In our validation cohort (30 CR patients and 30 control group), miRNA-142-3p and miRNA-24-3p expression levels were significantly upregulated, and miRNA-411-3p expression was significantly downregulated in the CR group. In conclusion, the miRNA-142-3p, miRNA-24-3p, and miRNA-411-3p might be potential markers for CR in CAD patients.

Echolucency of carotid plaque is useful for selecting high-risk patients with chronic coronary artery disease who benefit from intensive lipid-lowering therapy

BACKGROUND

Ultrasound assessment of the carotid artery provides prognostic information on coronary events. This study examined whether ultrasound assessments of plaque echolucency of the carotid artery are useful for identifying patients with coronary artery disease (CAD) who are at high risk but could benefit from lipid-lowering therapy for secondary prevention.

METHODS

Ultrasound assessment of carotid plaque echolucency with integrated backscatter (IBS) analysis was performed in 393 chronic CAD patients with low-density lipoprotein cholesterol (LDL-C) levels <100 mg/dL on statin therapy. All patients were prospectively followed up for a maximum of 96 months or until the occurrence of one of the following coronary events: cardiac death, nonfatal myocardial infarction, or unstable angina pectoris requiring unplanned revascularization.

RESULTS

During the follow-up period, 45 coronary events occurred. Patients were stratified by IBS (≤-16.3 or >-16.3 dB, median value) and LDL-C level (<70 or 70-99 mg/dL). Multivariate Cox proportional hazards analysis showed that patients with lower IBS and LDL-C 70-99 mg/dL had significantly higher probabilities of coronary events compared with those with higher IBS and LDL-C <70 mg/dL, after adjustment for a baseline model of risk factors (hazard ratio 5.15; 95% confidence interval 1.21-22.0, p = 0.03). In contrast, patients with lower IBS and LDL-C <70 mg/dL had an improved prognosis comparable with those with higher IBS. Addition of LDL-C levels to the baseline model of risk factors improved net reclassification improvement (NRI) and integrated discrimination improvement (IDI) in patients with lower IBS (NRI, 0.44, p = 0.04; and IDI, 0.035, p < 0.01), but not in those with higher IBS.

CONCLUSIONS

Evaluation of echolucency of the carotid artery was useful for selecting CAD patients at high risk of secondary coronary events but who could benefit from lipid-lowering therapy.

Up-regulation of PCSK6 by lipid oxidation products: A possible role in atherosclerosis

Atherosclerosis is a degenerative disease characterized by lesions that develop in the wall of large- and medium-sized arteries due to the accumulation of low-density lipoproteins (LDLs) in the intima. A growing bulk of evidence suggests that cholesterol oxidation products, known as oxysterols, and the aldehyde 4-hydroxy-2-nonenal (HNE), the major pro-atherogenic components of oxidized LDLs, significantly contribute to atherosclerotic plaque progression and destabilization, with eventual plaque rupture. The involvement of certain members of the protein convertase subtilisin/kexin proteases (PCSKs) in atherosclerosis has been recently hypothesized. Among them, PCSK6 has been associated with plaque instability, mainly thanks to its ability to stimulate the activity of matrix metalloproteinases (MMPs) involved in extracellular matrix remodeling and to enhance inflammation. In U937 promonocytic cells and in human umbilical vein endothelial cells, an oxysterol mixture and HNE were able to up-regulate the level and activity of PCSK6, resulting in MMP-9 activation as demonstrated by PCSK6 silencing. Inflammation, enhanced by these lipid oxidation products, plays a key role in the up-regulation of PCSK6 activity as demonstrated by cell pretreatment with NS-398, with epigallocatechin gallate or with acetylsalicylic acid, all with anti-inflammatory effects. For the first time, we demonstrated that both oxysterols and HNE, which substantially accumulate in the atherosclerotic plaque, up-regulate the activity of PCSK6. Of note, we also suggest a potential association between PCSK6 activity and MMP-9 activation, pointing out that PCSK6 could contribute to atherosclerotic plaque development.

Short-Term Acyl-CoA:Cholesterol Acyltransferase Inhibition, Combined with Apoprotein A1 Overexpression, Promotes Atherosclerosis Inflammation Resolution in Mice

Acyl-CoA:cholesterol acyltransferase (ACAT) mediates cellular cholesterol esterification. In atherosclerotic plaque macrophages, ACAT promotes cholesteryl ester accumulation, resulting in foam cell formation and atherosclerosis progression. Its complete inactivation in mice, however, showed toxic effects because of an excess of free cholesterol (FC) in macrophages, which can cause endoplasmic reticulum stress, cholesterol crystal formation, and inflammasome activation. Our previous studies showed that long-term partial ACAT inhibition, achieved by dietary supplementation with Fujirebio F1394, delays atherosclerosis progression in apoprotein E-deficient (Apoe ^-/-) mice by reducing plaque foam cell formation without inflammatory or toxic effects. Here, we determined whether short-term partial inhibition of ACAT, in combination with an enhanced systemic FC acceptor capacity, has synergistic benefits. Thus, we crossbred Apoe ^-/- with human apoprotein A1-transgenic (APOA1 ^tg/tg) mice, which have elevated cholesterol-effluxing high-density lipoprotein particles, and subjected Apoe ^-/- and APOA1 ^tg/tg/Apoe ^-/- mice to an atherogenic diet to develop advanced plaques. Then mice were either euthanized (baseline) or fed purified standard diet with or without F1394 for 4 more weeks. Plaques of APOA1 ^tg/tg/Apoe ^-/- mice fed F1394 showed a 60% reduction of macrophages accompanied by multiple other benefits, such as reduced inflammation and favorable changes in extracellular composition, in comparison with Apoe ^-/- baseline mice. In addition, there was no accumulation of cholesterol crystals or signs of toxicity. Overall, these results show that short-term partial ACAT inhibition, coupled to increased cholesterol efflux capacity, favorably remodels atherosclerosis lesions, supporting the potential of these combined therapies in the treatment of advanced atherosclerosis. SIGNIFICANCE STATEMENT: Short-term pharmacological inhibition of acyl-CoA:cholesterol acyltransferase-mediated cholesterol esterification, in combination with increased free cholesterol efflux acceptors, has positive effects in mice by 1) reducing the inflammatory state of the plaque macrophages and 2) favoring compositional changes associated with plaque stabilization. These effects occur without toxicity, showing the potential of these combined therapies in the treatment of advanced atherosclerosis.

The role of interferon-γ in cardiovascular disease: an update

PURPOSE

Cardiovascular disease (CVD) is the leading cause of death, globally, and its prevalence is only expected to rise due to the increasing incidence of co-morbidities such as obesity and diabetes. Medical treatment of CVD is directed primarily at slowing or reversing the underlying atherosclerotic process by managing circulating lipids with an emphasis on control of low-density lipoprotein (LDL) cholesterol. However, over the past several decades, there has been increasing recognition that chronic inflammation and immune system activation are important contributors to atherosclerosis. This shift in focus has led to the elucidation of the complex interplay between cholesterol and cellular secretion of cytokines involved in CVD pathogenesis. Of the vast array of cytokine promoting atherosclerosis, interferon (IFN)-γ is highly implicated and, therefore, of great interest.

METHODS

Literature review was performed to further understand the effect of IFN-γ on the development of atherosclerotic CVD.

RESULTS

IFN-γ, the sole member of the type II IFN family, is produced by T cells and macrophages, and has been found to induce production of other cytokines and to have multiple effects on all stages of atherogenesis. IFN-γ activates a variety of signaling pathways, most commonly the Janus kinase (JAK)/signal transducer and activator of transcription (STAT) pathway, to induce oxidative stress, promote foam cell accumulation, stimulate smooth muscle cell proliferation and migration into the arterial intima, enhance platelet-derived growth factor expression, and destabilize plaque. These are just a few of the contributions of IFN-γ to the initiation and progression of atherosclerotic CVD.

CONCLUSION

Given the pivotal role of IFN-γ in the advancement of CVD, activation of its signaling pathways is being explored as a driver of atherosclerosis. Manipulation of this key cytokine may lead to novel therapeutic avenues for CVD prevention and treatment. A number of therapies are being explored with IFN-γ as the potential target.

Artificial Intelligence Uncovered Clinical Factors for Cardiovascular Events in Myocardial Infarction Patients with Glucose Intolerance

PURPOSE

Glucose intolerance (GI), defined as either prediabetes or diabetes, promotes cardiovascular events in patients with myocardial infarction (MI). Using the pooled clinical data from patients with MI and GI in the completed ABC and PPAR trials, we aimed to identify their clinical risk factors for cardiovascular events.

METHODS

Using the limitless-arity multiple testing procedure, an artificial intelligence (AI)-based data mining method, we analyzed 415,328 combinations of < 4 clinical parameters.

RESULTS

We identified 242 combinations that predicted the occurrence of hospitalization for (1) percutaneous coronary intervention for stable angina, (2) non-fatal MI, (3) worsening of heart failure (HF), and (4) all causes, and we analyzed combinations in 1476 patients. Among these parameters, the use of proton pump inhibitors (PPIs) or plasma glucose levels > 200 mg/dl after 2 h of a 75 g oral glucose tolerance test were linked to the coronary events of (1, 2). Plasma BNP levels > 200 pg/dl were linked to coronary and cardiac events of (1, 2, 3). Diuretics use, advanced age, and lack of anti-dyslipidemia drugs were linked to cardiovascular events of (1, 3). All of these factors were linked to (4). Importantly, each finding was verified by independently drawn Kaplan-Meier curves, indicating that the determined factors accurately affected cardiovascular events.

CONCLUSIONS

In most previous MI patients with GI, progression of GI, PPI use, or high plasma BNP levels were linked to the occurrence of coronary stenosis or recurrent MI. We emphasize that use of AI may comprehensively uncover the hidden risk factors for cardiovascular events.

Lack of PCSK6 Increases Flow-Mediated Outward Arterial Remodeling in Mice

Proprotein convertases (PCSKs) process matrix metalloproteases and cytokines, but their function in the vasculature is largely unknown. Previously, we demonstrated upregulation of PCSK6 in atherosclerotic plaques from symptomatic patients, localization to smooth muscle cells (SMCs) in the fibrous cap and positive correlations with inflammation, extracellular matrix remodeling and cytokines. Here, we hypothesize that PCSK6 could be involved in flow-mediated vascular remodeling and aim to evaluate its role in the physiology of this process using knockout mice. Pcsk6^−/− and wild type mice were randomized into control and increased blood flow groups and induced in the right common carotid artery (CCA) by ligation of the left CCA. The animals underwent repeated ultrasound biomicroscopy (UBM) examinations followed by euthanization with subsequent evaluation using wire myography, transmission electron microscopy or histology. The Pcsk6^−/− mice displayed a flow-mediated increase in lumen circumference over time, assessed with UBM. Wire myography revealed differences in the flow-mediated remodeling response detected as an increase in lumen circumference at optimal stretch with concomitant reduction in active tension. Furthermore, a flow-mediated reduction in expression of SMC contractile markers SMA, MYH11 and LMOD1 was seen in the Pcsk6^−/− media. Absence of PCSK6 increases outward remodeling and reduces medial contractility in response to increased blood flow.

Molecular signatures of atherosclerotic plaques: An up-dated panel of protein related markers

Atherosclerosis remains the leading cause of ischemic syndromes such as myocardial infarction or brain stroke, mainly promoted by plaque rupture and subsequent arterial blockade. Identification of vulnerable or high-risk plaques constitutes a major challenge, being necessary to identify patients at risk of occlusive events in order to provide them with appropriate therapies. Clinical imaging tools have allowed the identification of certain structural indicators of prone-rupture plaques, including a necrotic lipidic core, intimal and adventitial inflammation, extracellular matrix dysregulation, and smooth muscle cell depletion and micro-calcification. Additionally, alternative approaches focused on identifying molecular biomarkers of atherosclerosis have also been applied. Among them, proteomics has provided numerous protein markers currently investigated in clinical practice. In this regard, it is quite uncertain that a single molecule can describe plaque rupture, due to the complexity of the process itself. Therefore, it should be more accurate to consider a set of markers to define plaques at risk. Herein, we propose a selection of 76 proteins, from classical inflammatory to recently related markers, all of them identified in at least two proteomic studies analyzing unstable atherosclerotic plaques. Such panel could be used as a prognostic signature of plaque instability.

The identification and function of a Netrin-1 mutation in a pedigree with premature atherosclerosis

BACKGROUND AND AIMS

Neuroimmune guidance cues have been shown to play a role in atherosclerosis, but their exact role in human pathophysiology is largely unknown. In the current study, we investigated the role of a c.1769G > T variant in Netrin-1 in (premature) atherosclerosis.

METHODS

To determine the effect of the genetic variation, purified Netrin-1, either wild type (wtNetrin-1) or the patient observed variation (mutNetrin-1), was used for migration, adhesion, endothelial barrier function and bindings assays. Expression of adhesion molecules and transcription proteins was analyzed by RT-PCR, Western blot or ELISA. To further delineate how mutNetrin-1 mediates its effect on cell migration, lenti-viral knockdown of UNC5B or DCC was used.

RESULTS

Bindings assays revealed a decreased binding capacity of mutNetrin-1 to the receptors UNC5B, DCC and β3-integrin and an increased binding capacity to neogenin, heparin and heparan sulfate compared to wtNetrin-1. Exposure of endothelial cells to mutNetrin-1 resulted in enhanced monocyte adhesion and expression of IL-6, CCL2 and ICAM-1 compared to wtNetrin-1. In addition, mutNetrin-1 lacks the inhibitory effect on the NF-κB pathway that is observed for wtNetrin-1. Moreover, the presence of mutNetrin-1 diminished migration of macrophages and smooth muscle cells. Importantly, UNC5B or DCC specific knockdown showed that mutNetrin-1 is unable to act through DCC resulting in enhanced inhibition of migration.

CONCLUSIONS

Our data demonstrates that mutNetrin-1 fails to exert anti-inflammatory effects on endothelial cells and more strongly blocks macrophage migration compared to wtNetrin-1, suggesting that the carriers of this genetic molecular variant may well be at risk for premature atherosclerosis.

Plasma BNP Levels and Diuretics Use as Predictors of Cardiovascular Events in Patients with Myocardial Infarction and Impaired Glucose Tolerance

PURPOSE

Although impaired glucose tolerance (IGT) promotes cardiovascular events, our Alpha-glucosidase-inhibitor Blocks Cardiac Events in Patients with Myocardial Infarction and Impaired Glucose Tolerance (ABC) study showed that alpha-glucosidase inhibitors do not prevent cardiovascular events in patients with myocardial infarction (MI) and IGT. The aim of the present study was to identify potential clinical factors for cardiovascular events in patients with MI and IGT.

METHODS

Using the limitless-arity multiple testing procedure, an artificial intelligence (AI)-based data mining method, we analyzed 385,391 combinations of fewer than four clinical parameters.

RESULTS

We identified 380 combinations predicting the occurrence of (1) all-cause hospitalization, (2) hospitalization due to worsening of heart failure (HF), (3) hospitalization due to non-fatal MI, and (4) hospitalization due to percutaneous coronary intervention (PCI) and coronary artery bypass grafting (CABG) for stable angina among 385,391 combinations in 853 patients. Among these, either plasma BNP levels ≥ 200 pg/dl or diuretic use exclusively predicted (1) all-cause hospitalization, (2) hospitalization due to worsening of HF, and (3) hospitalization due to a non-fatal MI, with plasma BNP levels ≥ 200 pg/dl being the sole predictor of hospitalization due to PCI and CABG. Importantly, each finding was verified by independently drawn Kaplan-Meier curves, revealing the unexpected role of plasma BNP levels in the progression of coronary stenosis determined as the necessity of PCI and CABG for stable angina.

CONCLUSIONS

In patients with MI and IGT, high plasma BNP levels predicted the occurrence of coronary stenosis, recurrent MI, and worsening of HF, whereas diuretic use did not predict the progression of coronary stenosis but non-fatal MI and worsening of HF.

Intravenous Administration of Allogenic Cell-Derived Microvesicles of Healthy Origins Defend Against Atherosclerotic Cardiovascular Disease Development by a Direct Action on Endothelial Progenitor Cells

Atherosclerosis and cardiovascular disease development is the outcome of intermediate processes where endothelial dysfunction and vascular inflammation are main protagonists. Cell-derived microvesicles (MVs), endothelial progenitor cells (EPCs), and circulating microRNAs (miRNAs) are known as biomarkers and potential regulators for atherosclerotic vascular disease, but their role in the complexity of the inflammatory process and in the mechanism of vascular restoration is far from clear. We aimed to evaluate the biological activity and functional role of MVs, in particular of the EPCs-derived MVs (MVEs), of healthy origins in reducing atherosclerotic vascular disease development. The experiments were performed on hamsters divided into the following groups: simultaneously hypertensive–hyperlipidemic (HH group) by combining two feeding conditions for 4 months; HH with retro-orbital sinus injection containing 1 × 10⁵ MVs or MVEs from control hamsters, one dose per month for 4 months of HH diet, to prevent atherosclerosis (HH-MVs or HH-MVEs group); and controls (C group), age-matched normal healthy animals. We found that circulating MV and MVE transplantation of healthy origins significantly reduces atherosclerosis development via (1) the mitigation of dyslipidemia, hypertension, and circulating EPC/cytokine/chemokine levels and (2) the structural and functional remodeling of arterial and left ventricular walls. We also demonstrated that (1) circulating MVs contain miRNAs; this was demonstrated by validating MVs and MVEs as transporters of Ago2-miRNA, Stau1-miRNA, and Stau2-miRNA complexes and (2) MV and MVE administration significantly protect against atherosclerotic cardiovascular disease via transfer of miR-223, miR-21, miR-126, and miR-146a to circulating late EPCs. It should be mentioned that the favorable effects of MVEs were greater than those of MVs. Our findings suggest that allogenic MV and MVE administration of healthy origins could counteract HH diet-induced detrimental effects by biologically active miR-10a, miR-21, miR-126, and miR-146a transfer to circulating EPCs, mediating their vascular repair function in atherosclerosis processes.

Nanoparticle-Aided Characterization of Arterial Endothelial Architecture during Atherosclerosis Progression and Metabolic Therapy

Atherosclerosis is associated with a compromised endothelial barrier, facilitating the accumulation of immune cells and macromolecules in atherosclerotic lesions. In this study, we investigate endothelial barrier integrity and the enhanced permeability and retention (EPR) effect during atherosclerosis progression and therapy in Apoe-/- mice using hyaluronan nanoparticles (HA-NPs). Utilizing ultrastructural and en face plaque imaging, we uncover a significantly decreased junction continuity in the atherosclerotic plaque-covering endothelium compared to the normal vessel wall, indicative of disrupted endothelial barrier. Intriguingly, the plaque advancement had a positive effect on junction stabilization, which correlated with a 3-fold lower accumulation of in vivo administrated HA-NPs in advanced plaques compared to early counterparts. Furthermore, by using super-resolution and correlative light and electron microscopy, we trace nanoparticles in the plaque microenvironment. We find nanoparticle-enriched endothelial junctions, containing 75% of detected HA-NPs, and a high HA-NP accumulation in the endothelium-underlying extracellular matrix, which suggest an endothelial junctional traffic of HA-NPs to the plague. Finally, we probe the EPR effect by HA-NPs in the context of metabolic therapy with a glycolysis inhibitor, 3PO, proposed as a vascular normalizing strategy. The observed trend of attenuated HA-NP uptake in aortas of 3PO-treated mice coincides with the endothelial silencing activity of 3PO, demonstrated in vitro. Interestingly, the therapy also reduced the plaque inflammatory burden, while activating macrophage metabolism. Our findings shed light on natural limitations of nanoparticle accumulation in atherosclerotic plaques and provide mechanistic insight into nanoparticle trafficking across the atherosclerotic endothelium. Furthermore, our data contribute to the rising field of endothelial barrier modulation in atherosclerosis.

Undetected Dysglycemia Is an Important Risk Factor for Two Common Diseases, Myocardial Infarction and Periodontitis: A Report From the PAROKRANK Study

OBJECTIVE

Information on the relationship among dysglycemia (prediabetes or diabetes), myocardial infarction (MI), and periodontitis (PD) is limited. This study tests the hypothesis that undetected dysglycemia is associated with both conditions.

RESEARCH DESIGN AND METHODS

The PAROKRANK (Periodontitis and Its Relation to Coronary Artery Disease) study included 805 patients with a first MI and 805 matched control subjects. All participants without diabetes (91%) were examined with an oral glucose tolerance test. Abnormal glucose tolerance (AGT) (impaired glucose tolerance or diabetes) was categorized according to the World Health Organization. Periodontal status was categorized from dental X-rays as healthy (≥80% remaining alveolar bone height), moderate (79-66%), or severe (<66%) PD. Odds ratios (ORs) and 95% CIs were calculated by logistic regression and were adjusted for age, sex, smoking, education, marital status, and explored associated risks of dysglycemia to PD and MI, respectively.

RESULTS

AGT was more common in patients than in control subjects (32% vs. 19%; P < 0.001) and was associated with MI (OR 2.03; 95% CI 1.58-2.60). Undetected diabetes was associated with severe PD (2.50; 1.36-4.63) and more strongly in patients (2.35; 1.15-4.80) than in control subjects (1.80; 0.48-6.78), but not when categorized as AGT (total cohort: 1.07; 0.67-1.72). Severe PD was most frequent in subjects with undetected diabetes, and reversely undetected diabetes was most frequent in patients with severe PD.

CONCLUSIONS

In this large case-control study previously undetected dysglycemia was independently associated to both MI and severe PD. In principal, it doubled the risk of a first MI and of severe PD. This supports the hypothesis that dysglycemia drives two common diseases, MI and PD.

Atheroprotective roles of smooth muscle cell phenotypic modulation and the TCF21 disease gene as revealed by single-cell analysis

In response to various stimuli, vascular smooth muscle cells (SMCs) can de-differentiate, proliferate and migrate in a process known as phenotypic modulation. However, the phenotype of modulated SMCs in vivo during atherosclerosis and the influence of this process on coronary artery disease (CAD) risk have not been clearly established. Using single cell RNA sequencing, we comprehensively characterized the transcriptomic phenotype of modulated SMCs in vivo in atherosclerotic lesions of both mouse and human arteries and found that these cells transform into unique fibroblast-like cells, termed “fibromyocytes”, rather than into a classical macrophage phenotype. SMC-specific knockout of TCF21, a causal CAD gene, markedly inhibited SMC phenotypic modulation in mice, leading to the presence of fewer fibromyocytes within lesions as well as within the protective fibrous cap of the lesions. Moreover, TCF21 expression was strongly associated with SMC phenotypic modulation in diseased human coronary arteries, and higher levels of TCF21 expression were associated with decreased CAD risk human CAD-relevant tissues. These results establish a protective role for both TCF21 and SMC phenotypic modulation in this disease.

Recent progress in LyP-1-based strategies for targeted imaging and therapy

The identification of markers expressed by pathological cells or their microenvironment would help to distinguish such cells from the normal tissues. The strategies derived from this theory can be a promising modality for imaging and treating diseases. LyP-1, a tumor homing peptide, can selectively bind to its receptor p32 protein overexpressed in various tumor-associated cells and atherosclerotic plaque macrophages. During recent decades, multiple types of LyP-1-based imaging probes and drug delivery systems have been designed and developed for diagnostic and therapeutic applications. This review first introduces LyP-1 and its receptor p32, as well as its homing, internalization and proapoptotic properties. Next, we highlight recent studies focusing on the applications of LyP-1-based strategies in the diagnosis and treatment of tumors, metastatic lesions, and atherosclerotic plaques. Finally, several limitations in the clinical translation of LyP-1-based bioconjugates are summarized.

HCV Extrahepatic Manifestations

Hepatitis C virus (HCV) has been shown to affect many tissues other than liver. However, of the many extrahepatic manifestations (EMs) that have been associated with HCV, including cryoglobulinemia, lymphoma, insulin resistance, type 2 diabetes and neurological disorders, only a few have been shown to be directly related to HCV infection of extrahepatic tissues. HCV-triggered immune-mediated mechanisms account for most of the EMs. It is estimated that up to 74% of patients with chronic hepatitis C can develop at least one EM. All HCV patients with EMs should be considered for antiviral therapy, although not all will resolve with sustained virological response.

Inhibitory effect of recombinant human CXCL8(3-72)K11R/G31P on atherosclerotic plaques in a mouse model of atherosclerosis

Context: Atherosclerosis is a chronic inflammatory disease in which the plaques were built up inside of the artery. Interleukin-8 (IL-8, CXCL8) is an inflammatory factor, known to play an important role in the development of atherosclerosis. G31P is an antagonist of the IL-8 receptor, which plays roles in vascular smooth muscle cell (VSMC) proliferation and migration. Objective: This study is to investigate the therapeutic effect of G31P on atherosclerosis through a mouse model. Materials and methods: A mouse model of atherosclerosis was generated through feeding the ApoE^-/- mice with high fat diet for 12 weeks. G31P was injected subcutaneously into the mice. The levels of keratinocyte chemoattractant (KC), CXCR2, TNF-α, and IFN-γ were analyzed through ELISA. The expressions of MMP-2, MMP-9, PCNA, and Mef2a in aortic tissues were detected through RT-qPCR. In A7r5 cells, the levels of p-ERK, ROCK1, and ROCK2 were analyzed by western blot. Intracellular calcium levels were measured through Fluo-3 AM assay. Results and disccussion: G31P suppressed the abnormal lipid profile and decreased the levels of KC, MMP-2, MMP-9, PCNA, and Mef2a in a mouse model of atherosclerosis. In addition, G31P also inhibited the expressions of p-ERK, ROCK1, ROCK2, and decreased the calcium concentrations in A7r5 cells. Conclusions: These findings indicate the potential therapeutic effects of G31P in suppressing the development of atherosclerosis by antagonizing the IL-8 receptor. G31P inhibits the proliferation and migration of VSMCs through regulating the Rho-kinase, ERK, and calcium-dependent pathways.

Forkhead Box C2 Attenuates Lipopolysaccharide-Induced Cell Adhesion via Suppression of Intercellular Adhesion Molecule-1 Expression in Human Umbilical Vein Endothelial Cells

Atherosclerosis is a chronic vascular inflammatory disease that involves diverse cell types and circulating regulatory factors, including intercellular adhesion molecule (ICAM)-1, a proinflammatory cytokine. Lipopolysaccharides (LPS) increase ICAM-1 expression and promote cell adhesion, but the mechanism is not clear. We found that LPS induced time- and dose-regulated upregulation of ICAM-1 expression and downregulation of forkhead box protein C2 (Foxc2) expression in human umbilical vein endothelial cells (HUVECs). Overexpression of Foxc2 significantly inhibited both LPS-induced ICAM-1 expression in HUVECs and LPS-induced adhesion of THP-1 cells to HUVECs. Foxc2 siRNA dramatically increased both LPS-induced ICAM-1 expression and LPS-induced adhesion of THP-1 human monocytes cells to HUVECs. We conclude that Foxc2 inhibited LPS-induced adhesion of THP-1 cells to HUVECs by suppressing ICAM-1 expression in HUVECs.

Proteasome biology and therapeutics in cardiac diseases

The ubiquitin proteasome system (UPS) is the major pathway for intracellular protein degradation in most organs, including the heart. UPS controls many fundamental biological processes such as cell cycle, cell division, immune responses, antigen presentation, apoptosis, and cell signaling. The UPS not only degrades substrates but also regulates activity of gene transcription at the post-transcription level. Emerging evidence suggests that impairment of UPS function is sufficient to cause a number of cardiac diseases, including heart failure, cardiomyopathies, hypertrophy, atrophy, ischemia-reperfusion, and atherosclerosis. Alterations in the expression of UPS components, changes in proteasomal peptidase activities and increased ubiquitinated and oxidized proteins have also been detected in diabetic cardiomyopathy (DCM). However, the pathophysiological role of the UPS in DCM has not been examined. Recently, in vitro and in vivo studies have proven highly valuable in assessing effects of various stressors on the UPS and, in some cases, suggesting a causal link between defective protein clearance and disease phenotypes in different cardiac diseases, including DCM. Translation of these findings to human disease can be greatly strengthened by corroboration of discoveries from experimental model systems using human heart tissue from well-defined patient populations. This review will summarize the general role of the UPS in different cardiac diseases, with major focus on DCM, and on recent advances in therapeutic development.

SM22α (Smooth Muscle Protein 22-α) Promoter-Driven IGF1R (Insulin-Like Growth Factor 1 Receptor) Deficiency Promotes Atherosclerosis

Objective- IGF-1 (insulin-like growth factor 1) is a major autocrine/paracrine growth factor, which promotes cell proliferation, migration, and survival. We have shown previously that IGF-1 reduced atherosclerosis and promoted features of stable atherosclerotic plaque in Apoe-/- mice-an animal model of atherosclerosis. The aim of this study was to assess effects of smooth muscle cell (SMC) IGF-1 signaling on the atherosclerotic plaque. Approach and Results- We generated Apoe-/- mice with IGF1R (IGF-1 receptor) deficiency in SMC and fibroblasts (SM22α [smooth muscle protein 22 α]-CreKI/IGF1R-flox mice). IGF1R was decreased in the aorta and adventitia of SM22α-CreKI/IGF1R-flox mice and also in aortic SMC, embryonic, skin, and lung fibroblasts isolated from SM22α-CreKI/IGF1R-flox mice. IGF1R deficiency downregulated collagen mRNA-binding protein LARP6 (La ribonucleoprotein domain family, member 6) and vascular collagen, and mice exhibited growth retardation. The high-fat diet-fed SM22α-CreKI/IGF1R-flox mice had increased atherosclerotic burden and inflammatory responses. α-SMA (α-smooth muscle actin)-positive plaque cells had reduced proliferation and elevated apoptosis. SMC/fibroblast-targeted decline in IGF-1 signaling decreased atherosclerotic plaque SMC, markedly depleted collagen, reduced plaque fibrous cap, and increased plaque necrotic cores. Aortic SMC isolated from SM22α-CreKI/IGF1R-flox mice had decreased cell proliferation, migration, increased sensitivity to apoptosis, and these effects were associated with disruption of IGF-1-induced Akt signaling. Conclusions- IGF-1 signaling in SMC and in fibroblast is a critical determinant of normal vascular wall development and atheroprotection.

Cardiovascular Outcomes in Patients With Previous Myocardial Infarction and Mild Diabetes Mellitus Following Treatment With Pioglitazone: Reports of a Randomised Trial From The Japan Working Group for the Assessment Whether ioglitazone rotects DM Patients gainst e-Infarction (PPAR Study)

BACKGROUND

Secondary prevention in patients with myocardial infarction (MI) is critically important to prevent ischaemic heart failure and reduce social burden. Pioglitazone improves vascular dysfunction and prevents coronary atherosclerosis, mainly via anti-inflammatory and antiatherogenic effects by enhancing adiponectin production in addition to antihyperglycemic effects, thus suggesting that pioglitazone attenuates cardiovascular events in patients with mild (HbA1c levels < 6·5%) diabetes mellitus (DM). Therefore, we evaluated the effects of pioglitazone on cardiovascular events in patients with both previous MI and mild DM.

METHODS

In this multicentre, prospective, randomised, open, blinded-endpoint trial, we randomly assigned 630 patients with mild DM with a history of MI to undergo either DM therapy with (pioglitazone group) or without (control group) pioglitazone. DM was diagnosed using the 75-g oral glucose tolerance test, and mild DM was defined if HbA1c level was < 6·5%. The primary endpoint was the composite of cardiovascular death and hospitalisation caused by acute MI, unstable angina, coronary revascularisation (including percutaneous coronary intervention and cardiac bypass surgery), and stroke.

FINDINGS

HbA1C levels were 5·9 and 5·8% (p = 0·71) at baseline and 6·0 and 5·8% (p < 0·01) at 2 years for the control and pioglitazone groups, respectively.The primary endpoint was observed in 14·2% and 14·1% patients in the control and pioglitazone groups during two years (95% confidential interval (CI):0.662-1·526, p = 0·98), respectively; the incidence of MI and cerebral infarction was 0·3% and 2·2% (95%CI: 0·786-32·415, p = 0·09) and 1·0% and 0·3% (95%CI: 0·051-3·662, p = 0·44), respectively. Post-hoc analyses of the 7-year observation period showed that these trends were comparable (21·9% and 19·2% in the control and pioglitazone groups, 95%CI: 0.618-1·237, p = 0·45).

INTERPRETATION

Pioglitazone could not reduce the occurrence of cardiovascular events in patients with mild DM and previous MI.

Dynamic Macrophages: Understanding Mechanisms of Activation as Guide to Therapy for Atherosclerotic Vascular Disease

An emerging theory is that macrophages are heterogenous; an attribute that allows them to change behavior and execute specific functions in disease processes. This review aims to describe the current understanding on factors that govern their phenotypic changes, and provide insights for intervention beyond managing classical risk factors. Evidence suggests that metabolic reprogramming of macrophages triggers either a pro-inflammatory, anti-inflammatory or pro-resolving behavior. Dynamic changes in bioenergetics, metabolome or influence from bioactive lipids may promote resolution or aggravation of inflammation. Direct cell-to-cell interactions with other immune cells can also influence macrophage activation. Both paracrine signaling and intercellular molecular interactions either co-stimulate or co-inhibit activation of macrophages as well as their paired immune cell collaborator. More pathways of activation can even be uncovered by inspecting macrophages in the single cell level, since differential expression in key gene regulators can be screened in higher resolution compared to conventional averaged gene expression readouts. All these emerging macrophage activation mechanisms may be further explored and consolidated by using approaches in network biology. Integrating these insights can unravel novel and safer drug targets through better understanding of the pro-inflammatory activation circuitry.