Where the Action Is-Leukocyte Recruitment in Atherosclerosis

Evaluations of metabolic and innate immunity profiles in subjects with familial hypercholesterolemia with or without subclinical atherosclerosis

BACKGROUND

Familial hypercholesterolemia (FH) is a genetic condition characterized by high low-density lipoprotein cholesterol (LDL-C). The presence of risk modifiers could promote the atherosclerotic injury beyond LDL-C. Our aim was to evaluate metabolic and innate immunity profiles in FH subjects with or without subclinical atherosclerosis.

METHODS

In this cross-sectional observational study, we evaluated 211 genetically confirmed FH subjects on LDL-C target and without cardiovascular diseases. Biochemical analyses, LDL-C burden (LCB) calculation and vascular profile evaluation were obtained from all subjects. Study population was divided into two groups according to subclinical atherosclerosis: the subclinical atherosclerosis (SA) group and non-subclinical atherosclerosis (NSA) group.

RESULTS

SA group had higher LDL-C at diagnosis (288.35 ± 24.52 vs 267.92 ± 23.86, p < 0.05) and LCB (13,465.84 ± 3617.46 vs 10,872.63 ± 3594.7, p < 0.001) than NSA group. SA group had higher white blood cell count (WBCC, 6.9 ± 1.66 vs 6.1 ± 1.16), neutrophil count (NC, 4.2 ± 1.3 vs 3.6 ± 1.11), monocyte count (MC, 0.8 ± 0.2 vs 0.4 ± 0.1), triglyceride to high-density lipoprotein ratio (TG/HDL, 1.73 ± 0.72 vs 1.45 ± 0.69), triglyceride-glucose index (TyG, 8.29 ± 0.35 vs 8.01 ± 0.33) than NSA group (p value for all < 0.01). Multivariate logistic regression analysis showed that LCB (p < 0.01), WBCC (p < 0.01), NC (p < 0.05), MC (p < 0.05) were associated with subclinical atherosclerosis. Simple linear regression analyses showed that LCB was associated with WBCC, NC, MC (p value for all < 0.01).

CONCLUSION

An increased LCB and an impaired innate immunity profile were found in FH subjects with subclinical atherosclerosis and they were independently associated with atherosclerotic injury. LCB could modulate the innate immunity profile.

Early-life exposure to PCBs and PFAS exerts negative effects on the developing central nervous system

Persistent organic pollutants (POPs) are ubiquitous in the environment and display the capacity to bioaccumulate in living organisms, constituting a hazard to both wildlife and humans. Although restrictions have been applied to prohibit the production of several POPs since the 1960s, high levels of these compounds can still be detected in many environmental and biological matrices, due to their chemical properties and significantly long half-lives. Some POPs can be passed from mother to the fetus and can gain entry to the central nervous system (CNS), by crossing the blood-brain barrier (BBB), resulting in significant deleterious effects, including neurocognitive and psychiatric abnormalities, which may lead to long-term socio-economic burdens. A growing body of evidence obtained from clinical and experimental studies has increasingly indicated that these POPs may influence neurodevelopment through several cellular and molecular mechanisms. However, studies assessing their mechanisms of action are still incipient, requiring further research. Polychlorinated biphenyls (PCBs) and per- and polyfluoroalkyl substances (PFAS) are two of the main classes of POPs associated with disturbances in different human systems, mainly the nervous and endocrine systems. This narrative review discusses the main PCB and PFAS effects on the CNS, focusing on neuroinflammation and oxidative stress and their consequences for neural development and BBB integrity. Moreover, we propose which mechanisms could be involved in POP-induced neurodevelopmental defects. In this sense, we highlight potential cellular and molecular pathways by which these POPs can affect neurodevelopment and could be further explored to propose preventive therapies and formulate public health policies.

Real-Time Imaging Assessment of Stress-Induced Vascular Inflammation Using Heartbeat-Synchronized Motion Compensation

BACKGROUND

Chronic mental stress accelerates atherosclerosis through complicated neuroimmune pathways, needing for advanced imaging techniques to delineate underlying cellular mechanisms. While histopathology, ex vivo imaging, and snapshots of in vivo images offer promising evidence, they lack the ability to capture real-time visualization of blood cell dynamics within pulsatile arteries in longitudinal studies.

METHODS

An electrically tunable lens was implemented in intravital optical microscopy, synchronizing the focal plane with heartbeats to follow artery movements. ApoE-/- mice underwent 2 weeks of restraint stress before baseline imaging followed by 2 weeks of stress exposure in the longitudinal imaging, while nonstressed mice remained undisturbed. The progression of vascular inflammation was assessed in the carotid arteries through intravital imaging and histological analyses.

RESULTS

A 4-fold reduction of motion artifact, assessed by interframe SD, and an effective temporal resolution of 25.2 Hz were achieved in beating murine carotid arteries. Longitudinal intravital imaging showed chronic stress led to a 6.09-fold (P=0.017) increase in myeloid cell infiltration compared with nonstressed mice. After 3 weeks, we observed that chronic stress intensified vascular inflammation, increasing adhered myeloid cells by 2.45-fold (P=0.031), while no significant changes were noted in nonstressed mice. Microcirculation imaging revealed increased circulating, rolling, and adhered cells in stressed mice's venules. Histological analysis of the carotid arteries confirmed the in vivo findings that stress augmented plaque area, myeloid cell and macrophage accumulation, and necrotic core volume while reducing fibrous cap thickness indicating accelerated plaque formation. We visualized the 3-dimensional structure of the carotid artery and 4-dimensional dynamics of the venules in the cremaster muscle.

CONCLUSIONS

Dynamic focusing motion compensation intravital microscopy enabled subcellular resolution in vivo imaging of blood cell dynamics in beating arteries under chronic restraint stress in real time. This novel technique emphasizes the importance of advanced in vivo imaging for understanding cardiovascular disease.

Evaluation of Inflammatory Markers in Predicting Coronary Complexity: Insights from the SYNTAX II Score in NSTEMI Patients

Objectives: Non-ST-elevation myocardial infarction (NSTEMI) is characterized by the absence of pathological ST segment elevation but an increase in biological markers. The SYNTAX II score (SS-II) is calculated to evaluate the complexity of coronary artery disease and to guide treatment decisions between percutaneous coronary intervention (PCI) and coronary artery bypass grafting (CABG). The aim of this study is to evaluate the relationship of socio-demographic data and biochemical markers with SS-II in NSTEMI patients. Materials and Methods: Six hundred patients who were admitted to the private Aktif International Hospital cardiology clinic between January 2020 and January 2024 and were diagnosed with NSTEMI were included in the study. Severity, extent, and clinical evaluation of atherosclerosis were determined using risk factors, laboratory tests, and coronary angiography. Patients were divided into two groups according to their SS-II score: low (≤ 22) and high SS-II (> 32). Socio-demographic data, neutrophil-to-lymphocyte ratio (NLR), monocyte-to-lymphocyte ratio (MLR), and monocyte-to-HDL-C ratio (MHR) were compared between the two groups. Results: Group 1 (SS-II ≤ 22) included 380 patients, and group 2 (SS-II > 32) included 220 patients. There was a statistically significant difference in HDL, creatine value, white blood cell, troponin I, hs-TnT, and monocyte values in group 2 compared with group 1 (p = 0.001, p = 0.018, p = 0.031, and p = 0.001, respectively). NLR, MLR, MHR, and SS values were statistically significantly higher in group 2 compared with group 1 (p = 0.015, p = 0.002, p = 0.001, and p = 0.001, respectively). The risk factors were found to be significantly associated with high-risk NSTEMI (SS-II > 32) in a logistic regression analysis and included peripheral artery disease (PAD) (OR: 3.028, p = 0.040), troponin I (OR: 3.575, p = 0.015), hs-TnT (OR: 4.221, p = 0.010), NLR (OR: 1.528, p = 0.024). MLR (OR: 5.248, p = 0.012), and MHR (OR: 7.122, p = 0.010). ROC analysis revealed that NLR (AUC: 0.691, p = 0.016), MLR (AUC: 0.731, p = 0.004), and MHR (AUC: 0.824, p = 0.003) had higher predictive power than other parameters in patients with high-risk NSTEMI (SS-II > 32). Conclusions: We found that NLR, MLR, and MHR levels are associated with the severity of coronary artery disease. We think that adding these easily and quickly measurable parameters to routine laboratory results may support the clinician in evaluating the complexity of coronary artery disease and guiding treatment decisions in NSTEMI patients.

Blockade of mTORC1 via Rapamycin Suppresses 27-Hydroxycholestrol-Induced Inflammatory Responses

Atherosclerosis is characterized by the deposition and accumulation of extracellular cholesterol and inflammatory cells in the arterial blood vessel walls, and 27-hydroxycholesterol (27OHChol) is the most abundant cholesterol metabolite. 27OHChol is an oxysterol that induces immune responses, including immune cell activation and chemokine secretion, although the underlying mechanisms are not fully understood. In this study, we investigated the roles of the mechanistic target of rapamycin (mTOR) in 27HChol-induced inflammation using rapamycin. Treating monocytic cells with rapamycin effectively reduced the expression of CCL2 and CD14, which was involved with the increased immune response by 27OHChol. Rapamycin also suppressed the phosphorylation of S6 and 4EBP1, which are downstream of mTORC1. Additionally, it also alleviates the increase in differentiation markers into macrophage. These results suggest that 27OHChol induces inflammation by activating the mTORC1 signaling pathway, and rapamycin may be useful for the treatment of atherosclerosis-related inflammation involving 27OHchol.

Neuroimmune crosstalk : How mental stress fuels vascular inflammation

Cardiovascular diseases are the leading cause of death worldwide. Pathophysiologically, metabolic and inflammatory processes contribute substantially to the development and progression of cardiovascular diseases. Over the past decade, the role of disease-propagating inflammatory processes has been strengthened and reframed, leading to trials testing anti-inflammatory drugs for the treatment of atherosclerosis and its complications. Despite these achievements, further research in both pre-clinical and clinical studies is warranted to explore new targets, to better identify responders, and to refine therapy strategies to combat inflammation in human disease. Environmental disturbances, so-called lifestyle-associated cardiovascular risk factors, greatly alter the immune system in general and leukocytes in particular, thus affecting the progression of atherosclerosis. Epidemiological studies have shown that exposure to mental stress can be closely linked to the occurrence of cardiovascular disease. Here, we describe how acute and chronic mental stress alter the immune system via neuroimmune interactions, thereby modifying vascular inflammation. In addition, we identify gaps that still need to be addressed in the future.

Deletion of Talin1 in Myeloid Cells Facilitates Atherosclerosis in Mice

BACKGROUND

Integrin-regulated monocyte recruitment and cellular responses of monocyte-derived macrophages are critical for the pathogenesis of atherosclerosis. In the canonical model, talin1 controls ligand binding to integrins, a prerequisite for integrins to mediate leukocyte recruitment and induce immune responses. However, the role of talin1 in the development of atherosclerosis has not been studied. Our study investigated how talin1 in myeloid cells regulates the progression of atherosclerosis.

METHODS

On an Apoe-/- background, myeloid talin1-deficient mice and the control mice were fed with a high-fat diet for 8 or 12 weeks to induce atherosclerosis. The atherosclerosis development in the aorta and monocyte recruitment into atherosclerotic lesions were analyzed.

RESULTS

Myeloid talin1 deletion facilitated the formation of atherosclerotic lesions and macrophage deposition in lesions. Talin1 deletion abolished integrin β2-mediated adhesion of monocytes but did not impair integrin α4β1-dependent cell adhesion in a flow adhesion assay. Strikingly, talin1 deletion did not prevent Mn2+- or chemokine-induced activation of integrin α4β1 to the high-affinity state for ligands. In an in vivo competitive homing assay, monocyte infiltration into inflamed tissues was prohibited by antibodies to integrin α4β1 but was not affected by talin1 deletion or antibodies to integrin β2. Furthermore, quantitative polymerase chain reaction and ELISA (enzyme-linked immunosorbent assay) analysis showed that macrophages produced cytokines to promote inflammation and the proliferation of smooth muscle cells. Ligand binding to integrin β3 inhibited cytokine generation in macrophages, although talin1 deletion abolished the negative effects of integrin β3.

CONCLUSIONS

Integrin α4β1 controls monocyte recruitment during atherosclerosis. Talin1 is dispensable for integrin α4β1 activation to the high-affinity state and integrin α4β1-mediated monocyte recruitment. Yet, talin1 is required for integrin β3 to inhibit the production of inflammatory cytokines in macrophages. Thus, intact monocyte recruitment and elevated inflammatory responses cause enhanced atherosclerosis in talin1-deficient mice. Our study provides novel insights into the roles of myeloid talin1 and integrins in the progression of atherosclerosis.

Anti-atherogenic mechanism of ethanol extract of Christia vespertilionis (L.f.) Bakh. F. Leaves in vitro

BACKGROUND

Vascular inflammation is the key event in early atherogenesis. Pro-inflammatory endothelial cells induce monocyte recruitment into the sub-endothelial layer of the artery. This requires endothelial expression of adhesion molecules namely intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1), alongside chemokines production. Christia vespertilionis (L.f.) Bakh.f. (CV) possesses anti-inflammatory property. However, its potential anti-atherogenic effect in the context of vascular inflammation has yet to be explored.

PURPOSE

To evaluate the anti-atherogenic mechanism of 80% ethanol extract of CV leaves on tumor necrosis factor-α (TNF-α)-activated human umbilical vein endothelial cells (HUVECs).

METHODS

Qualitative analysis of the CV extract was carried out by using liquid chromatography with tandem mass spectrometry (LC-MS/MS). The cell viability of HUVECs treated with CV extract was determined by MTT assay. The effect of CV extract on monocyte adhesion was determined by monocyte-endothelial adhesion assay. Protein expressions of ICAM-1, VCAM-1 and nuclear factor-kappa B (NF-κB) signaling pathway were determined by western blot while production of monocyte chemoattractant protein-1 (MCP-1) was determined by ELISA.

RESULTS

LC-MS/MS analysis showed that CV extract composed of five main compounds, including schaftoside, orientin, isovitexin, 6-caffeoyl-D-glucose, and 3,3'-di-O-methyl ellagic acid. Treatment of CV extract at a concentration range from 5 to 60 µg/mL for 24 h maintained HUVECs viability above 90 %, therefore concentrations of 20, 40 and 60 μg/mL were selected for the subsequent experiments. All concentrations of CV extract showed a significant inhibitory effect on monocyte adhesion to TNF-α-activated HUVECs (p < 0.05). In addition, the protein expressions of ICAM-1 and VCAM-1 were significantly attenuated by CV in a concentration dependent manner (p < 0.001). At all tested concentrations, CV extract also exhibited significant inhibition on the production of MCP-1 (p < 0.05). Moreover, CV extract significantly inhibited TNF-α-induced phosphorylation of inhibitor of nuclear factor-κB kinase alpha/beta (IKKα/β), inhibitor kappa B-alpha (IκBα), NF-κB and nuclear translocation of NF-κB (p < 0.05).

CONCLUSION

CV extract inhibited monocyte adhesion to endothelial cells by suppressing protein expressions of cell adhesion molecules and production of chemokines through downregulation of NF-κB signaling pathway. Thus, CV has the potential to be developed as an anti-atherogenic agent for early treatment of atherosclerosis.

Engineering blood and lymphatic microvascular networks

The human vasculature plays a crucial role in the blood supply of nearly all organs as well as the drainage of the interstitial fluid. Consequently, if these physiological systems go awry, pathological changes might occur. Hence, the regeneration of existing vessels, as well as approaches to engineer artificial blood and lymphatic structures represent current challenges within the field of vascular research. In this review, we provide an overview of both the vascular blood circulation and the long-time neglected but equally important lymphatic system, with regard to their organotypic vasculature. We summarize the current knowledge within the field of vascular tissue engineering focusing on the design of co-culture systems, thereby mainly discussing suitable cell types, scaffold design and disease models. This review will mainly focus on addressing those subjects concerning atherosclerosis. Moreover, current technological approaches such as vascular organ-on-a-chip models and microfluidic devices will be discussed.

Advances in the treatment of atherosclerosis with ligand-modified nanocarriers

Atherosclerosis, a chronic disease associated with metabolism, poses a significant risk to human well-being. Currently, existing treatments for atherosclerosis lack sufficient efficiency, while the utilization of surface-modified nanoparticles holds the potential to deliver highly effective therapeutic outcomes. These nanoparticles can target and bind to specific receptors that are abnormally over-expressed in atherosclerotic conditions. This paper reviews recent research (2018-present) advances in various ligand-modified nanoparticle systems targeting atherosclerosis by specifically targeting signature molecules in the hope of precise treatment at the molecular level and concludes with a discussion of the challenges and prospects in this field. The intention of this review is to inspire novel concepts for the design and advancement of targeted nanomedicines tailored specifically for the treatment of atherosclerosis.

Effect of GLP-1RA Treatment on Adhesion Molecules and Monocyte Chemoattractant Protein-1 in Diabetic Patients with Atherosclerosis

Cardiovascular disease (CVD) remains a prominent cause of global mortality, primarily driven by atherosclerosis. Diabetes mellitus, as a modifiable risk factor, significantly contributes to atherogenesis. Monocyte recruitment to the intima is a critical step in atherosclerotic plaque formation, involving chemokines and adhesion molecules such as selectins, ICAM-1, and MCP-1. Glucagon-like peptide 1 receptor agonists (GLP-1RAs) are a promising group of drugs for reducing cardiovascular risk in diabetic patients, prompting investigation into their mechanisms of action. This interventional study enrolled 50 diabetes patients with atherosclerotic plaque, administering GLP-1RA for 180 days. Serum concentrations of MCP-1, ICAM-1, and L-selectin were measured before and after treatment. Anthropometric and biochemical parameters were also assessed. GLP-1RA treatment resulted in significant improvements in anthropometric parameters, glycemic control, blood pressure, and biochemical markers of liver steatosis. Biomarker laboratory analysis revealed higher baseline levels of MCP-1, ICAM-1, and L-selectin in diabetic patients with atherosclerotic plaque compared to healthy controls. Following treatment, MCP-1 and L-selectin levels decreased significantly (p < 0.001), while ICAM-1 levels increased (p < 0.001). GLP-1RA treatment in diabetic patients with atherosclerotic plaque leads to favorable changes in serum molecule levels associated with monocyte recruitment to the endothelium. The observed reduction in MCP-1 and L-selectin suggests a potential mechanism underlying GLP-1RA-mediated cardiovascular risk reduction. Further research is warranted to elucidate the precise mechanisms and clinical implications of these findings in diabetic patients with atherosclerosis.

Online application for the diagnosis of atherosclerosis by six genes

BACKGROUND

Atherosclerosis (AS) is a primary contributor to cardiovascular disease, leading to significant global mortality rates. Developing effective diagnostic indicators and models for AS holds the potential to substantially reduce the fatalities and disabilities associated with cardiovascular disease. Blood sample analysis has emerged as a promising avenue for facilitating diagnosis and assessing disease prognosis. Nonetheless, it lacks an accurate model or tool for AS diagnosis. Hence, the principal objective of this study is to develop a convenient, simple, and accurate model for the early detection of AS.

METHODS

We downloaded the expression data of blood samples from GEO databases. By dividing the mean values of housekeeping genes (meanHGs) and applying the comBat function, we aimed to reduce the batch effect. After separating the datasets into training, evaluation, and testing sets, we applied differential expression analyses (DEA) between AS and control samples from the training dataset. Then, a gradient-boosting model was used to evaluate the importance of genes and identify the hub genes. Using different machine learning algorithms, we constructed a prediction model with the highest accuracy in the testing dataset. Finally, we make the machine learning models publicly accessible by shiny app construction.

RESULTS

Seven datasets (GSE9874, GSE12288, GSE20129, GSE23746, GSE27034, GSE90074, and GSE202625), including 403 samples with AS and 325 healthy subjects, were obtained by comprehensive searching and filtering by specific requirements. The batch effect was successfully removed by dividing the meanHGs and applying the comBat function. 331 genes were found to be related to atherosclerosis by the DEA analysis between AS and health samples. The top 6 genes with the highest importance values from the gradient boosting model were identified. Out of the seven machine learning algorithms tested, the random forest model exhibited the most impressive performance in the testing datasets, achieving an accuracy exceeding 0.8. While the batch effect reduction analysis in our study could have contributed to the increased accuracy values, our comparison results further highlight the superiority of our model over the genes provided in published studies. This underscores the effectiveness of our approach in delivering superior predictive performance. The machine-learning models were then uploaded to the Shiny app's server, making it easy for users to distinguish AS samples from normal samples.

CONCLUSIONS

A prognostic Shiny application, built upon six potential atherosclerosis-associated genes, has been developed, offering an accurate diagnosis of atherosclerosis.

Development of stem cell therapy for atherosclerosis

Cardiovascular disease (CVD) has a high incidence and low cure rate worldwide, and atherosclerosis (AS) is the main factor inducing cardiovascular disease, of which lipid deposition in the vessel wall is the main marker of AS. Currently, although statins can be used to lower lipids and low-density lipoprotein (LDL) in AS, the cure rate for AS remains low. Therefore, there is an urgent need to develop new therapeutic approaches, and stem cells are now widely studied, while stem cells are a class of cell types that always maintain the ability to differentiate and can differentiate to form other cells and tissues, and stem cell transplantation techniques have shown efficacy in the treatment of other diseases. With the establishment of cellular therapies and continued research in stem cell technology, stem cells are also being used to address the problem of AS. In this paper, we focus on recent research advances in stem cell therapy for AS and briefly summarize the relevant factors that induce the formation of AS. We mainly discuss the efficacy and application prospects of mesenchymal stem cells (MSCs) for the treatment of AS, in addition to the partial role and potential of exosomes in the treatment of AS. Further, provide new ideas for the clinical application of stem cells.

Comprehensive proteomics of monocytes indicates oxidative imbalance functionally related to inflammatory response in chronic kidney disease-related atherosclerosis

Atherosclerosis-induced cardiovascular events are the leading cause of mortality in chronic kidney disease (CKD) patients. Monocytes are involved in the formation of atherosclerotic plaques and mediate in the overproduction of ROS, promoting inflammation and oxidative stress. However, the relationship between monocytes, inflammation, and oxidative status in CKD-associated atherosclerosis has not been thoroughly investigated. Monocytes and plasma derived from two groups of CKD patients with varying degrees of atherosclerosis and two groups of patients with cardiovascular disease (CVD) and non-CKD atherosclerosis were analyzed. This study was designed to perform a comprehensive proteomic analysis of monocytes in combination with functional bioinformatics. In addition, a targeted investigation of oxidative stress- and inflammatory-related factors to explore CKD-associated atherosclerosis was applied. Dysregulation of proteins involved in lipid oxidation, cell survival, ROS synthesis and metabolism, and inflammatory responses has been revealed. The characteristic disturbances in the monocyte proteome changed with the progression of CKD. A closer examination of oxidative stress's triggers, mediators, and effects on protein and lipid levels showed alterations in the oxidative imbalance between CKD and CVD. CKD monocytes demonstrated a significant increase of oxidized glutathione without changing the level of its reduced form. Evaluation of enzymatic antioxidants, sources of ROS, and modifications caused by ROS also revealed significant alterations between the study groups. In CKD, inflammation and oxidative imbalance correlated and drove each other. However, in CVD, oxidative stress-related factors were associated with each other but not to inflammatory proteins. Moreover, lipid abnormalities were more specific to classical CVD and unrelated to CKD. Such a comprehensive characterization of monocytes and oxidative stress in CKD and CVD patients has never been presented so far. Obtained results support the involvement of distinct mechanisms underlying the acceleration of atherosclerotic and non-atherosclerotic CKD.

LncRNA PSMB8-AS1 Instigates Vascular Inflammation to Aggravate Atherosclerosis

BACKGROUND

Increasing evidence suggests that long noncoding RNAs play significant roles in vascular biology and disease development. One such long noncoding RNA, PSMB8-AS1, has been implicated in the development of tumors. Nevertheless, the precise role of PSMB8-AS1 in cardiovascular diseases, particularly atherosclerosis, has not been thoroughly elucidated. Thus, the primary aim of this investigation is to assess the influence of PSMB8-AS1 on vascular inflammation and the initiation of atherosclerosis.

METHODS

We generated PSMB8-AS1 knockin and Apoe (Apolipoprotein E) knockout mice (Apoe-/-PSMB8-AS1KI) and global Apoe and proteasome subunit-β type-9 (Psmb9) double knockout mice (Apoe-/-Psmb9-/-). To explore the roles of PSMB8-AS1 and Psmb9 in atherosclerosis, we fed the mice with a Western diet for 12 weeks.

RESULTS

Long noncoding RNA PSMB8-AS1 is significantly elevated in human atherosclerotic plaques. Strikingly, Apoe-/-PSMB8-AS1KI mice exhibited increased atherosclerosis development, plaque vulnerability, and vascular inflammation compared with Apoe-/- mice. Moreover, the levels of VCAM1 (vascular adhesion molecule 1) and ICAM1 (intracellular adhesion molecule 1) were significantly upregulated in atherosclerotic lesions and serum of Apoe-/-PSMB8-AS1KI mice. Consistently, in vitro gain- and loss-of-function studies demonstrated that PSMB8-AS1 induced monocyte/macrophage adhesion to endothelial cells and increased VCAM1 and ICAM1 levels in a PSMB9-dependent manner. Mechanistic studies revealed that PSMB8-AS1 induced PSMB9 transcription by recruiting the transcription factor NONO (non-POU domain-containing octamer-binding protein) and binding to the PSMB9 promoter. PSMB9 (proteasome subunit-β type-9) elevated VCAM1 and ICAM1 expression via the upregulation of ZEB1 (zinc finger E-box-binding homeobox 1). Psmb9 deficiency decreased atherosclerotic lesion size, plaque vulnerability, and vascular inflammation in Apoe-/- mice in vivo. Importantly, endothelial overexpression of PSMB8-AS1-increased atherosclerosis and vascular inflammation were attenuated by Psmb9 knockout.

CONCLUSIONS

PSMB8-AS1 promotes vascular inflammation and atherosclerosis via the NONO/PSMB9/ZEB1 axis. Our findings support the development of new long noncoding RNA-based strategies to counteract atherosclerotic cardiovascular disease.

Targeting endothelial vascular cell adhesion molecule-1 in atherosclerosis: drug discovery and development of vascular cell adhesion molecule-1-directed novel therapeutics

Vascular cell adhesion molecule-1 (VCAM-1) has been well established as a critical contributor to atherosclerosis and consequently as an attractive therapeutic target for anti-atherosclerotic drug candidates. Many publications have demonstrated that disrupting the VCAM-1 function blocks monocyte infiltration into the sub-endothelial space, which effectively prevents macrophage maturation and foam cell transformation necessary for atherosclerotic lesion formation. Currently, most VCAM-1-inhibiting drug candidates in pre-clinical and clinical testing do not directly target VCAM-1 itself but rather down-regulate its expression by inhibiting upstream cytokines and transcriptional regulators. However, the pleiotropic nature of these regulators within innate immunity means that optimizing dosage to a level that suppresses pathological activity while preserving normal physiological function is extremely challenging and oftentimes infeasible. In recent years, highly specific pharmacological strategies that selectively inhibit VCAM-1 function have emerged, particularly peptide- and antibody-based novel therapeutics. Studies in such VCAM-1-directed therapies so far remain scarce and are limited by the constraints of current experimental atherosclerosis models in accurately representing the complex pathophysiology of the disease. This has prompted the need for a comprehensive review that recounts the evolution of VCAM-1-directed pharmaceuticals and addresses the current challenges in novel anti-atherosclerotic drug development.

Prognostic Value of Multiple Complete Blood Count-Derived Indices in Intermediate Coronary Lesions

Complete blood count (CBC)-derived indices have been proposed as reliable inflammatory biomarkers to predict outcomes in the context of coronary artery disease. These indices have yet to be thoroughly validated in patients with intermediate coronary stenosis. Our study included 1527 patients only with intermediate coronary stenosis. The examined variables were neutrophil-lymphocyte ratio (NLR), derived NLR, monocyte-lymphocyte ratio (MLR), platelet-lymphocyte ratio (PLR), systemic immune inflammation index (SII), system inflammation response index (SIRI), and aggregate index of systemic inflammation (AISI). The primary endpoint was the composite of major adverse cardiovascular events (MACEs), including all-cause death, non-fatal myocardial infarction, and unplanned revascularization. Over a follow-up of 6.11 (5.73-6.55) years, MACEs occurred in 189 patients. Receiver operator characteristic curve analysis showed that SIRI outperformed other indices with the most significant area under the curve. In the multivariable analysis, SIRI (hazard ratio [HR] 1.588, 95% confidence interval [CI] 1.138-2.212) and AISI (HR 1.673, 95% CI 1.217-2.300) were the most important prognostic factors among all the indices. The discrimination ability of each index was strengthened in patients with less burden of modifiable cardiovascular risk factors. SIRI also exhibited the best incremental value beyond the traditional cardiovascular risk model.

The Role of Selenium in Atherosclerosis Development, Progression, Prevention and Treatment

Selenium is an essential trace element that is essential for various metabolic processes, protection from oxidative stress and proper functioning of the cardiovascular system. Se deficiency has long been associated with multiple cardiovascular diseases, including endemic Keshan's disease, common heart failure, coronary heart disease, myocardial infarction and atherosclerosis. Through selenoenzymes and selenoproteins, Se is involved in numerous crucial processes, such as redox homeostasis regulation, oxidative stress, calcium flux and thyroid hormone metabolism; an unbalanced Se supply may disrupt these processes. In this review, we focus on the importance of Se in cardiovascular health and provide updated information on the role of Se in specific processes involved in the development and pathogenesis of atherosclerosis (oxidative stress, inflammation, endothelial dysfunction, vascular calcification and vascular cell apoptosis). We also discuss recent randomised trials investigating Se supplementation as a potential therapeutic and preventive agent for atherosclerosis treatment.

The role of protein glycosylation in the occurrence and outcome of acute ischemic stroke

Acute ischemic stroke (AIS) is a serious and life-threatening disease worldwide. Despite thrombolysis or endovascular thrombectomy, a sizeable fraction of patients with AIS have adverse clinical outcomes. In addition, existing secondary prevention strategies with antiplatelet and anticoagulant drugs therapy are not able to adequately decrease the risk of ischemic stroke recurrence. Thus, exploring novel mechanisms for doing so represents an urgent need for the prevention and treatment of AIS. Recent studies have discovered that protein glycosylation plays a critical role in the occurrence and outcome of AIS. As a common co- and post-translational modification, protein glycosylation participates in a wide variety of physiological and pathological processes by regulating the activity and function of proteins or enzymes. Protein glycosylation is involved in two causes of cerebral emboli in ischemic stroke: atherosclerosis and atrial fibrillation. Following ischemic stroke, the level of brain protein glycosylation becomes dynamically regulated, which significantly affects stroke outcome through influencing inflammatory response, excitotoxicity, neuronal apoptosis, and blood-brain barrier disruption. Drugs targeting glycosylation in the occurrence and progression of stroke may represent a novel therapeutic idea. In this review, we focus on possible perspectives about how glycosylation affects the occurrence and outcome of AIS. We then propose the potential of glycosylation as a therapeutic drug target and prognostic marker for AIS patients in the future.

Neutrophil-to-Lymphocyte Ratio Is an Independent Risk Factor for Coronary Artery Disease in Central Obesity

Several inflammatory biomarkers were found to be associated with an increased risk of cardiovascular disease. Neutrophil-to-lymphocyte ratio (NLR) is a marker of subclinical inflammation that increases with the stress response. Visceral adiposity index (VAI) calculated as a combination of anthropometric and metabolic parameters reflects both the extent and function of visceral adipose tissue. Given the association of subclinical inflammation with both obesity and cardiovascular diseases, it is plausible that the inflammation-CVD association is modulated by the amount and function of adipose tissue. Thus, our aim was to examine the association between NLR and coronary artery calcium score (CACS), an intermediate marker of coronary artery disease in asymptomatic patients across VAI tertiles. Methods: Data from 280 asymptomatic participants of a cardiovascular screening program were analysed. In addition to the collection of lifestyle and medical history, a non-contrast cardiac CT scan and laboratory tests were performed on all participants. Multivariate logistic regression was conducted with CACS > 100 as the outcome and with conventional cardiovascular risk factors and NLR, VAI, and NLR by VAI tertile as predictors. Results: We found an interaction between VAI tertiles and NLR; NLR values were similar in the lower VAI tertiles, while they were higher in the CACS > 100 in the 3rd VAI tertile (CACS ≤ 100: 1.94 ± 0.58 vs. CACS > 100: 2.48 ± 1.1, p = 0.008). According to multivariable logistic regression, the interaction between NLR and VAI tertiles remained: NLR was associated with CACS > 100 in the 3rd VAI tertile (OR = 1.67, 95% CI 1.06-2.62, p = 0.03) but not in the lower tertiles even after adjustment for age, sex, smoking, history of hypertension, hyperlipidaemia, and diabetes mellitus, as well as high-sensitivity C-reactive protein. Our findings draw attention to the independent association between subclinical, chronic, systemic inflammation and subclinical coronary disease in obesity.

Stress induced proinflammatory adaptations: Plausible mechanisms for the link between stress and cardiovascular disease

Initiating from Hans Selye’s conceptualization of stress physiology, to our present understanding of allostatic load as the cumulative burden of chronic psychological stress and life events, investigators have sought to identify the physiological mechanisms that link stress to health and disease. Of particular interest has been the link between psychological stress and cardiovascular disease (CVD), the number one cause of death in the United States. In this regard, attention has been directed toward alterations in the immune system in response to stress that lead to increased levels of systemic inflammation as a potential pathway by which stress contributes to the development of CVD. More specifically, psychological stress is an independent risk factor for CVD, and as such, mechanisms that explain the connection of stress hormones to systemic inflammation have been examined to gain a greater understanding of the etiology of CVD. Research on proinflammatory cellular mechanisms that are activated in response to psychological stress demonstrates that the ensuing low-grade inflammation mediates pathways that contribute to the development of CVD. Interestingly, physical activity, along with its direct benefits to cardiovascular health, has been shown to buffer against the harmful consequences of psychological stress by “toughening” the SAM system, HPA axis, and immune system as “cross-stressor adaptations” that maintain allostasis and prevent allostatic load. Thus, physical activity training reduces psychological stress induced proinflammation and attenuates the activation of mechanisms associated with the development of cardiovascular disease. Finally, COVID-19 associated psychological stress and its associated health risks has provided another model for examining the stress-health relationship.

Cross-linking porcine peritoneum by oxidized konjac glucomannan: a novel method to improve the properties of cardiovascular substitute material

The use of natural polysaccharide crosslinkers for decellularized matrices is an effective approach to prepare cardiovascular substitute materials. In this research, NaIO4 was applied to oxidize konjac glucomannan to prepare the polysaccharide crosslinker oxidized konjac glucomannan (OKGM). The as-prepared crosslinker was then used to stabilize collagen-rich decellularized porcine peritoneum (DPP) to construct a cardiovascular substitute material (OKGM-fixed DPP). The results demonstrated that compared with GA-fixed DPP and GNP-fixed DPP, 3.75% OKGM [1:1.5 (KGM: NaIO4)]-fixed DPP demonstrated suitable mechanical properties, as well as good hemocompatibility, excellent anti-calcification capability, and anti-enzymolysis in vitro. Furthermore, 3.75% OKGM [1:1.5 (KGM: NaIO4)]-fixed DPP was suitable for vascular endothelial cell adhesion and rapid proliferation, and a single layer of endothelial cells was formed on the fifth day of culture. The in vivo experimental results also showed excellent histocompatibility. The current results demonstrted that OKGM was a novel polysaccharide cross-linking reagent for crosslinking natural tissues featured with rich collagen content, and 3.75% OKGM [1:1.5 (KGM: NaIO4)]-fixed DPP was a potential cardiovascular substitute material.

Graphical Abstract

The Impact of Exercise on Immunity, Metabolism, and Atherosclerosis

Physical exercise represents an effective preventive and therapeutic strategy beneficially modifying the course of multiple diseases. The protective mechanisms of exercise are manifold; primarily, they are elicited by alterations in metabolic and inflammatory pathways. Exercise intensity and duration strongly influence the provoked response. This narrative review aims to provide comprehensive up-to-date insights into the beneficial effects of physical exercise by illustrating the impact of moderate and vigorous exercise on innate and adaptive immunity. Specifically, we describe qualitative and quantitative changes in different leukocyte subsets while distinguishing between acute and chronic exercise effects. Further, we elaborate on how exercise modifies the progression of atherosclerosis, the leading cause of death worldwide, representing a prime example of a disease triggered by metabolic and inflammatory pathways. Here, we describe how exercise counteracts causal contributors and thereby improves outcomes. In addition, we identify gaps that still need to be addressed in the future.

CD14+-Monocytes Exposed to Apolipoprotein CIII Express Tissue Factor

Apolipoprotein CIII (ApoCIII) represents a key regulator of plasma lipid metabolism and a recognized risk factor for atherosclerosis and cardiovascular diseases. Beyond the regulation of lipoprotein trafficking, ApoCIII is also involved in endothelial dysfunction and monocyte recruitment related to atherothrombosis. With tissue factor (TF) being the primary initiator of the blood coagulation cascade, we hypothesized that ApoCIII-treated monocytes could express it. Hence, human CD14⁺-monocytes and autologous neutrophils were incubated with ApoCIII and sera from human subjects containing previously measured ApoCIII amounts. By RT-qPCR and ELISA, CD14⁺-monocytes, but not neutrophils, were found to show increased mRNA expression and production of TNFα, IL-1β and IL-6 as well as TF mRNA once exposed to ultra-purified ApoCIII. By flow cytometry, CD14⁺-monocytes were found to rapidly express TF on their cell surface membrane when incubated with either ApoCIII or sera with known concentrations of ApoCIII. Finally, preincubation with specific ApoCIII-neutralizing antibodies significantly reduced the ability of most sera with known concentrations of ApoCIII to upregulate TF protein, other than partially inhibiting cytokine release, in CD14⁺-monocytes. In sum, herein we demonstrate that ApoCIII activates CD14⁺-monocytes to express TF. The data identify a potential mechanism which links circulating apolipoproteins with inflammation and atherothrombosis-related processes underlying cardiovascular risk.

Quo Vadis? Immunodynamics of Myeloid Cells after Myocardial Infarction

Myocardial infarction (MI), a major contributor to worldwide morbidity and mortality, is caused by a lack of blood flow to the heart. Affected heart tissue becomes ischemic due to deficiency of blood perfusion and oxygen delivery. In case sufficient blood flow cannot be timely restored, cardiac injury with necrosis occurs. The ischemic/necrotic area induces a systemic inflammatory response and hundreds of thousands of leukocytes are recruited from the blood to the injured heart. The blood pool of leukocytes is rapidly depleted and urgent re-supply of these cells is needed. Myeloid cells are generated in the bone marrow (BM) and spleen, released into the blood, travel to sites of need, extravasate and accumulate inside tissues to accomplish various functions. In this review we focus on the "leukocyte supply chain" and will separately evaluate different myeloid cell compartments (BM, spleen, blood, heart) in steady state and after MI. Moreover, we highlight the local and systemic kinetics of extracellular factors, chemokines and danger signals involved in the regulation of production/generation, release, transportation, uptake, and activation of myeloid cells during the inflammatory phase of MI.

Circulating Ageing Neutrophils as a Marker of Asymptomatic Polyvascular Atherosclerosis in Statin-Naïve Patients without Established Cardiovascular Disease

Background: Current data on the possible involvement of aging neutrophils in atherogenesis are limited. This study aimed to research the diagnostic value of aging neutrophils in their relation to subclinical atherosclerosis in statin-naïve patients without established atherosclerotic cardiovascular diseases (ASCVD). Methods: The study was carried out on 151 statin-naïve patients aged 40–64 years old without ASCVD. All patients underwent duplex scanning of the carotid arteries, lower limb arteries and abdominal aorta. Phenotyping and differentiation of neutrophil subpopulations were performed through flow cytometry (Navios 6/2, Beckman Coulter, USA). Results: The number of CD62L^loCXCR4^hi-neutrophils is known to be significantly higher in patients with subclinical atherosclerosis compared with patients without atherosclerosis (p = 0.006). An increase in the number of CD62L^loCXCR4^hi-neutrophils above cut-off values makes it possible to predict atherosclerosis in at least one vascular bed with sensitivity of 35.4–50.5% and specificity of 80.0–92.1%, in two vascular beds with sensitivity of 44.7–84.4% and specificity of 80.8–33.3%. Conclusion: In statin-naïve patients 40–64 years old without established ASCVD with subclinical atherosclerosis, there is an increase in circulating CD62L^loCXCR4^hi-neutrophils. It was also concluded that the increase in the number of circulating CD62L^loCXCR4^hi-neutrophils demonstrated moderate diagnostic efficiency (AUC 0.617–0.656) in relation to the detection of subclinical atherosclerosis, including polyvascular atherosclerosis.

Orphan GPR26 Counteracts Early Phases of Hyperglycemia-Mediated Monocyte Activation and Is Suppressed in Diabetic Patients

Diabetes is the ninth leading cause of death, with an estimated 1.5 million deaths worldwide. Type 2 diabetes (T2D) results from the body’s ineffective use of insulin and is largely the result of excess body weight and physical inactivity. T2D increases the risk of cardiovascular diseases, retinopathy, and kidney failure by two-to three-fold. Hyperglycemia, as a hallmark of diabetes, acts as a potent stimulator of inflammatory condition by activating endothelial cells and by dysregulating monocyte activation. G-protein couple receptors (GPCRs) can both exacerbate and promote inflammatory resolution. Genome-wide association studies (GWAS) indicate that GPCRs are differentially regulated in inflammatory and vessel cells from diabetic patients. However, most of these GPCRs are orphan receptors, for which the mechanism of action in diabetes is unknown. Our data indicated that orphan GPCR26 is downregulated in the PBMC isolated from T2D patients. In contrast, GPR26 was initially upregulated in human monocytes and PBMC treated with high glucose (HG) levels and then decreased upon chronic and prolonged HG exposure. GPR26 levels were decreased in T2D patients treated with insulin compared to non-insulin treated patients. Moreover, GPR26 inversely correlated with the BMI and the HbA1c of diabetic compared to non-diabetic patients. Knockdown of GPR26 enhanced monocyte ROS production, MAPK signaling, pro-inflammatory activation, monocyte adhesion to ECs, and enhanced the activity of Caspase 3, a pro-apoptotic molecule. The same mechanisms were activated by HG and exacerbated when GPR26 was knocked down. Hence, our data indicated that GPR26 is initially activated to protect monocytes from HG and is inhibited under chronic hyperglycemic conditions.

Colchicine Impacts Leukocyte Trafficking in Atherosclerosis and Reduces Vascular Inflammation

Background

Inflammation strongly contributes to atherosclerosis initiation and progression. Consequently, recent clinical trials pharmacologically targeted vascular inflammation to decrease the incidence of atherosclerosis-related complications. Colchicine, a microtubule inhibitor with anti-inflammatory properties, reduced cardiovascular events in patients with recent acute coronary syndrome and chronic coronary disease. However, the biological basis of these observations remains elusive. We sought to explore the mechanism by which colchicine beneficially alters the course of atherosclerosis.

Methods and Results

In mice with early atherosclerosis (Apoe-/- mice on a high cholesterol diet for 8 weeks), we found that colchicine treatment (0.25 mg/kg bodyweight once daily over four weeks) reduced numbers of neutrophils, inflammatory monocytes and macrophages inside atherosclerotic aortas using flow cytometry and immunohistochemistry. Consequently, colchicine treatment resulted in a less inflammatory plaque composition and reduced plaque size. We next investigated how colchicine prevented plaque leukocyte expansion and found that colchicine treatment mitigated recruitment of blood neutrophils and inflammatory monocytes to plaques as revealed by adoptive transfer experiments. Causally, we found that colchicine reduced levels of both leukocyte adhesion molecules and receptors for leukocyte chemoattractants on blood neutrophils and monocytes. Further experiments showed that colchicine treatment reduced vascular inflammation also in post-myocardial infarction accelerated atherosclerosis through similar mechanisms as documented in early atherosclerosis. When we examined whether colchicine also decreased numbers of macrophages inside atherosclerotic plaques by impacting monocyte/macrophage transitioning or in-situ proliferation of macrophages, we report that colchicine treatment did not influence macrophage precursor differentiation or macrophage proliferation using cell culture experiments with bone marrow derived macrophages.

Conclusions

Our data reveal that colchicine prevents expansion of plaque inflammatory leukocytes through lowering recruitment of blood myeloid cells to plaques. These data provide novel mechanistic clues on the beneficial effects of colchicine in the treatment of atherosclerosis and may inform future anti-inflammatory interventions in patients at risk.

Capmatinib suppresses LPS-induced interaction between HUVECs and THP-1 monocytes through suppression of inflammatory responses

BACKGROUND

Capmatinib (CAP) is a drug that has been used to treat non-small cell lung cancer (NSCLC) in adults. Presently, its novel effects on skeletal muscle insulin signaling, inflammation, and lipogenesis in adipocytes have been uncovered with a perspective of drug repositioning. However, the impact of CAP on LPS-mediated adhesion between human umbilical vein endothelial cells (HUVECs) and THP-1 monocytes has yet to be investigated.

METHODS

HUVECs and THP-1 monocytes were treated with LPS and CAP. The protein expression levels were determined using Western blotting. Target protein knockdown was conducted using small interfering (si) RNA transfection. Adhesion between HUVECs and THP-1 cells was assayed using green fluorescent dye.

RESULTS

This study found that CAP treatment ameliorated cell adhesion between THP-1 monocytes and HUVECs and the expression of adhesive molecules, such as intracellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), and E-selectin. Moreover, phosphorylation of inflammatory markers, such as NFκB and IκB as well as TNFα and monocyte chemoattractant protein-1 (MCP-1) released from HUVECs and THP-1 monocytes, was prevented by CAP treatment. Treatment with CAP augmented PPARα and IL-10 expression. siRNA-associated suppression of PPARδ and IL-10 attenuated the effects of CAP on cell adhesion between HUVECs and THP-1 cells and inflammatory responses. Further, PPARα siRNA mitigated CAP-mediated induction of IL-10 expression.

CONCLUSION

These findings imply that CAP improves inflamed endothelial-monocyte adhesion via a PPAR/IL-10-dependent pathway. The current study provides in vitro evidence for a therapeutic approach for treating atherosclerosis.

Elevated platelet-leukocyte complexes are associated with, but dispensable for myocardial ischemia-reperfusion injury

AIMS

P-selectin is an activatable adhesion molecule on platelets promoting platelet aggregation, and platelet-leukocyte complex (PLC) formation. Increased numbers of PLC are circulating in the blood of patients shortly after acute myocardial infarction and predict adverse outcomes. These correlations led to speculations about whether PLC may represent novel therapeutic targets. We therefore set out to elucidate the pathomechanistic relevance of PLC in myocardial ischemia and reperfusion injury.

METHODS AND RESULTS

By generating P-selectin deficient bone marrow chimeric mice, the post-myocardial infarction surge in PLC numbers in blood was prevented. Yet, intravital microscopy, flow cytometry and immunohistochemical staining, echocardiography, and gene expression profiling showed unequivocally that leukocyte adhesion to the vessel wall, leukocyte infiltration, and myocardial damage post-infarction were not altered in response to the lack in PLC.

CONCLUSION

We conclude that myocardial infarction associated sterile inflammation triggers PLC formation, reminiscent of conserved immunothrombotic responses, but without PLC influencing myocardial ischemia and reperfusion injury in return. Our experimental data do not support a therapeutic concept of selectively targeting PLC formation in myocardial infarction.