Mast cells as effectors in atherosclerosis

Therapeutic Avenues to Modulate B-Cell Function in Patients With Cardiovascular Disease

The adaptive immune system plays an important role in the development and progression of atherosclerotic cardiovascular disease. B cells can have both proatherogenic and atheroprotective roles, making treatments aimed at modulating B cells important therapeutic targets. The innate-like B-cell response is generally considered atheroprotective, while the adaptive response is associated with mixed consequences for atherosclerosis. Additionally, interactions of B cells with components of the adaptive and innate immune system, including T cells and complement, also represent key points for therapeutic regulation. In this review, we discuss therapeutic approaches based on B-cell depletion, modulation of B-cell survival, manipulation of both the antibody-dependent and antibody-independent B-cell response, and emerging immunization techniques.

The Impact of Weight Cycling on Health and Obesity

Obesity is a systemic and chronic inflammation, which seriously endangers people's health. People tend to diet to control weight, and the short-term effect of dieting in losing weight is significant, but the prognosis is limited. With weight loss and recovery occurring frequently, people focus on weight cycling. The effect of weight cycling on a certain tissue of the body also has different conclusions. Therefore, this article systematically reviews the effects of body weight cycling on the body and finds that multiple weight cycling (1) increased fat deposition in central areas, lean mass decreased in weight loss period, and fat mass increased in weight recovery period, which harms body composition and skeletal muscle mass; (2) enhanced the inflammatory response of adipose tissue, macrophages infiltrated into adipose tissue, and increased the production of pro-inflammatory mediators in adipocytes; (3) blood glucose concentration mutation and hyperinsulinemia caused the increase or decrease in pancreatic β-cell population, which makes β-cell fatigue and leads to β-cell failure; (4) resulted in additional burden on the cardiovascular system because of cardiovascular rick escalation. Physical activity combined with calorie restriction can effectively reduce metabolic disease and chronic inflammation, alleviating the adverse effects of weight cycling on the body.

Thrombomodulin as a potential diagnostic marker of acute myocardial infarction and correlation with immune infiltration: Comprehensive analysis based on multiple machine learning

BACKGROUND

Acute myocardial infarction (AMI) is a global health problem with high mortality. Early diagnosis can prevent the development of AMI and provide valuable information for subsequent treatment. Angiogenesis has been shown to be a critical factor in the development of infarction and targeting this process may be a potential protective strategy for preventing myocardial injury and improving the prognosis of AMI patients. This study aimed to screen and verify diagnostic markers related to angiogenesis in AMI and to investigate the molecular mechanisms of action associated with AMI in terms of immune cell infiltration.

METHODS

The GSE66360 and the GSE60993 datasets were both downloaded from the GEO database and were used as the training cohort and the external validation cohort, respectively. Angiogenesis-related genes (ARGs) were downloaded from the MSigDB database. The hub ARGs were identified via LASSO, RF, and SVM-RFE algorithms. ROC curves were used to assess the accuracy of the hub ARGs. The potential mechanisms of the hub ARGs were analyzed by GSEA. The ssGSEA algorithm was used to determine differences in immune cell infiltration and immune function. The CIBERSORT algorithm was used for immune cell infiltration analysis. In addition, we constructed a ceRNA network map of differentially expressed ARGs.

RESULTS

We identified the thrombomodulin (THBD) gene from ARGs as a potential diagnostic marker for AMI based on the LASSO, SVM-RFE, and RF algorithms. THBD was differentially expressed and had a potential diagnostic value (area under the curve [AUC] = 0.931 and 0.765 in the training and testing datasets, respectively). GSEA showed that the MAPK signaling pathway was more enriched in the high-expression group of THBD (P < 0.05). Immune cell infiltration analysis demonstrated that THBD was mainly positively correlated with monocytes (R = 0.48, P = 0.00055) and neutrophils (R = 0.36, P = 0.013). Finally, in the ceRNA regulatory network, THBD was closely associated with 9 miRNAs and 42 lncRNAs involved in AMI.

CONCLUSION

THBD can be used as a potential diagnostic marker for AMI. This study provides new insights for future AMI diagnosis and molecular mechanism research. Moreover, immune cell infiltration plays an essential role in the occurrence and development of AMI.

The Relationship Between Allergic Rhinitis, Asthma, and Cardiovascular Disease in the National Health Interview Surveys (NHIS), 1999-2018

BACKGROUND

Atopic disease has been associated with immune dysregulation and chronic inflammation, but current practice guideline recommendations do not include the evaluation of inflammatory outcomes among patients with asthma and allergic rhinitis (AR).

OBJECTIVE

This study investigates the relationship between asthma, AR, and cardiovascular disease (CVD) using data from the U.S. National Health Interview Survey (NHIS) between 1999 and 2018.

METHODS

We used data from adults in the NHIS (n = 603,140, representing a population of 225,483,286). Exposures were physician-diagnosed asthma (lifetime/past-year) and AR (past-year). Outcomes were physician-diagnosed heart disease: coronary heart disease (CHD), angina, heart attack, and nonspecific "heart-condition" (all lifetime). We used survey-weighted descriptive analysis and logistic regression adjusting for demographic and socioeconomic factors.

RESULTS

A total of 11.44% reported at least 1 heart condition, with CHD the most prevalent (4.27%) across 20 years of pooled data. Asthma and AR were associated with higher CVD in all bivariate analyses. Specifically, lifetime asthma was associated with increased odds of CHD, (odds ratio [OR] 1.36; 95% confidence interval [95% CI] 1.29-1.42), with stronger effects observed for a past-year asthma attack (OR 1.66; 95% CI 1.55-1.80). The strongest effect of all was observed in those with a past-year asthma attack having increased odds of angina (OR 2.42; 95% CI 2.24-2.63). Allergic rhinitis was independently associated with increased odds of CHD (OR 1.25; 95% CI 1.18-1.28).

CONCLUSIONS

Asthma and AR are risk factors for all types of CVD in this nationally representative study covering a 2-decade period in the United States. Clinicians should consider screening patients with severe and/or uncontrolled asthma and AR early for CVD, particularly angina and CHD. Future studies are warranted to explore the immunological milieu in these patients and identify therapeutic targets.

Systemic Inflammation in Asthma: What Are the Risks and Impacts Outside the Airway?

Airway inflammation in asthma has been well recognized for several decades, with general agreement on its role in asthma pathogenesis, symptoms, propensity toward exacerbation, and decline in lung function. This has led to universal recommendation in asthma management guidelines to incorporate the use of inhaled corticosteroid as an anti-inflammatory therapy for all patients with persistent asthma symptoms. However, there has been limited attention paid to the presence and potential impact of systemic inflammation in asthma. Accumulating evidence from epidemiological observations and cohort studies points to a host of downstream organ dysfunction in asthma especially among patients with longstanding or more severe disease, frequent exacerbations, and underlying risk factors for organ dysfunction. Most studies to date have focused on cognitive impairment, depression/anxiety, metabolic syndrome, and cardiovascular abnormalities. In this review, we summarize some of the evidence demonstrating these abnormalities and highlight the proposed mechanisms and potential benefits of treatment in limiting these extrapulmonary abnormalities in patients with asthma. The goal of this commentary is to raise awareness of the importance of recognizing potential extrapulmonary conditions associated with systemic inflammation of asthma. This area of treatment of patients with asthma is a large unmet need.

Palmitic acid in type 2 diabetes mellitus promotes atherosclerotic plaque vulnerability via macrophage Dll4 signaling

Patients with Type 2 Diabetes Mellitus are increasingly susceptible to atherosclerotic plaque vulnerability, leading to severe cardiovascular events. In this study, we demonstrate that elevated serum levels of palmitic acid, a type of saturated fatty acid, are significantly linked to this enhanced vulnerability in patients with Type 2 Diabetes Mellitus. Through a combination of human cohort studies and animal models, our research identifies a key mechanistic pathway: palmitic acid induces macrophage Delta-like ligand 4 signaling, which in turn triggers senescence in vascular smooth muscle cells. This process is critical for plaque instability due to reduced collagen synthesis and deposition. Importantly, our findings reveal that macrophage-specific knockout of Delta-like ligand 4 in atherosclerotic mice leads to reduced plaque burden and improved stability, highlighting the potential of targeting this pathway. These insights offer a promising direction for developing therapeutic strategies to mitigate cardiovascular risks in patients with Type 2 Diabetes Mellitus.

Relationship between stress and coronary artery disease: A comprehensive review

Coronary artery disease (CAD) poses a substantial public health challenge. This review examines the intricate relationship between psychological stress and CAD, drawing from recent research spanning the last 5 to 10 years. The literature review is organized around critical themes. It includes an analysis of genetic loci in CAD susceptibility and underscores the role of green environments in reducing cardiovascular risk. A quantitative analysis presents numerical findings for clarity, while pathophysiological mechanisms are elucidated through informative figures and diagrams. The review engages with controversies and disparities in the literature, offering a balanced perspective. A tabular comparative analysis outlines the strengths and limitations of existing approaches, emphasizing conflicting findings, and environmental factors. The review concludes by distilling key takeaways for healthcare professionals and researchers. Practical implications are explored, and lessons learned from the research process are reflected upon. The conclusion also suggests avenues for further study in understanding stress's impact on CAD.

Targeting inflammation in atherosclerosis: overview, strategy and directions

Atherosclerosis is a chronic condition characterised by the build-up of plaque in the inner lining of the blood vessels and it is the main underlying cause of cardiovascular disease. The development of atherosclerosis is associated with the accumulation of cholesterol and inflammation. Although effective therapies exist to lower low-density lipoprotein cholesterol (LDL-C) levels, some patients still experience cardiovascular events due to persistent inflammation, known as residual inflammatory risk (RIR). Researchers have conducted laboratory and animal studies to investigate the measurement and targeting of the inflammatory cascade associated with atherosclerosis, which have yielded promising results. In addition to guideline-directed lifestyle modifications and optimal medical therapy focusing on reducing LDL-C levels, pharmacological interventions targeting inflammation may provide further assistance in preventing future cardiac events. This review aims to explain the mechanisms of inflammation in atherosclerosis, identifies potential biomarkers, discusses available therapeutic options and their strengths and limitations, highlights future advancements, and summarises notable clinical studies. Finally, an evaluation and management algorithm for addressing RIR is presented.

Single cell RNA-sequencing suggests a novel lipid associated mast cell population following weight cycling

Our recent study showed weight cycled mice have increased adipose mast cells compared to obese mice by single cell RNA-sequencing. Here, we aimed to confirm and elucidate these changes. Further analysis of our dataset showed that our initial mast cell cluster could subcluster into two unique populations: one with very high expression of classical mast cell markers and another with elevated lipid handling and antigen presentation genes. This new mast cell cluster accounted for most of the mast cells in the weight cycled group although it was not possible to detect the different populations by new studies with flow cytometry or Toluidine blue staining in mice, possibly due to a downregulation in classical mast cell genes. Interestingly, a pilot study in humans did suggest the existence of two mast cell populations in subcutaneous adipose tissue from obese women that appear similar to the murine populations detected by sequencing; one of which was significantly correlated with weight variance. Together, these data suggest that weight cycling may induce a unique population of mast cells similar to lipid associated macrophages. Future studies will focus on isolation of these cells to better determine their lineage, differentiation, and functional roles.

Role of inflammation and immune response in atherosclerosis: Mechanisms, modulations, and therapeutic targets

Cardiovascular diseases (CVDs) have emerged as the leading cause of mortality globally, with atherosclerosis being a prominent focus of investigation among medical researchers worldwide. Atherosclerosis is characterized as a disease of the large and medium-sized arteries that is multifocal, accumulative, and immunoinflammatory in nature, resulting from the deposition of lipids. Accumulating evidence suggests that inflammatory responses and immunoregulation play a vital role in the occurrence and development of atherosclerosis. While existing treatments for atherosclerosis can assist in symptom management and slowing disease progression, a complete cure remains elusive. Consequently, there is significant interest in research and development of potential new drugs for this condition. Therefore, this review aims to consolidate the current understanding of the pathogenesis of atherosclerosis with an emphasis on inflammation, immune response and infection. Besides, it examines the effects and mechanisms of immunological modulations in atherosclerosis, and the potential therapeutic targets and drugs for intervening in the inflammatory responses and immunoregulation associated with atherosclerosis. Additionally, novel drug options for treating atherosclerosis are explored within the context of this review.

Chronic Spontaneous Urticaria in Belgium: Deciphering the Clinical Profile and Treatment of Patients Visiting an Urban City Immunology Department

BACKGROUND

Chronic urticaria (CSU) is a chronic inflammatory mast cell-driven disorder of which reliable clinical data in Belgium are lacking. This study focusses on clinical characteristics of CSU patients presenting at an urban Immunology-Allergology department.

METHODS

Outpatients with CSU were included from 2018 to 2021. Clinical characteristics, Dermatology Life Quality Index (DLQI) and Urticaria activity score (UAS7) were collected by thorough anamnesis and questionnaires. Furthermore, patients underwent provocational testing, an autologous serum skin test (ASST) and a blood analysis.

RESULTS

The study included 49 CSU patients and 20 non-CSU subjects. CSU was distributed differently with age and sex, showing higher numbers in female patients below the age of 46 years. 67% of CSU patients had accompanying angioedema of which 9% were reported genital. CSU patients scored a mean 8/30 on their DLQI questionnaire. There was no significant difference in immunoglobulin E (IgE), C-reactive protein, and tryptase levels between CSU patients and controls. Oral glucocorticosteroids were prescribed in 23% of CSU patients during their disease course though only half of these patients had a severity grade 4 CSU. In 82% of the included CSU patients, Urticaria Control Test (UCT) scores were below 12. When we hypothetically considered low IgE levels and high IgG anti-thyroid peroxidase levels as differentiation marker for autoimmune (ai)CSU and non-aiCSU, we found that 4% of all included CSU patients could be considered aiCSU.

CONCLUSION

Generally, the inner-city population displayed the same clinical characteristics, as previous cohorts from Northern Europe. The relatively high rate of CSU patients receiving oral glucocorticosteroid treatment for their disease though not always classified as severe, underlines the need to train doctors of various specialties in the treatment algorithms of CSU. Furthermore, by looking at potential autoimmune characteristics, our findings open perspectives on the identification of new routinely used clinical parameters for the detection of aiCSU, a relatively small immunological subtype of CSU.

Exploring the genetic association of allergic diseases with cardiovascular diseases: a bidirectional Mendelian randomization study

Background

In observational and experimental studies, allergic diseases (AD) have been reported to be associated with some types of cardiovascular diseases (CVD), as both share common pathophysiological processes involving inflammation and metabolic disorders. However, the direction of the causal association between them remains unclear. This Mendelian randomization (MR) study aims to examine the bidirectional causality between AD and CVD.

Methods

We utilized publicly available genome-wide association study (GWAS) summary statistics data from European participants in the UK Biobank and the IEU Open GWAS database. Genetic variants associated with AD, asthma, and CVD were identified and used as instrumental variables to investigate the genetically causal association between them. MR analyses were performed using various analytical methods, including inverse variance weighted-fixed effects (IVW-FE), inverse variance weighted-multiplicative random effects (IVW-RE), MR-Egger, weighted median, weighted mode, and maximum likelihood. Sensitivity tests were conducted to assess the validity of the causality.

Results

The MR analysis with the IVW method revealed a genetically predicted association between AD and essential hypertension [odds ratio (OR)=0.9987, 95% confidence interval (CI): 0.9976-0.9998, P=0.024], as well as between asthma and atrial fibrillation (OR=1.001, 95% CI: 1.0004-1.0017, P=6.43E-05). In the reverse MR analyses, heart failure was associated with allergic diseases (OR=0.0045, 95% CI: 1.1890E-04 - 0.1695, P=0.004), while atherosclerosis (OR=8.7371E-08, 95% CI: 1.8794E-14 - 4.0617E-01, P=0.038) and aortic aneurysm and dissection (OR=1.7367E-07, 95% CI: 3.8390E-14 - 7.8567E-01, P=0.046) might be protective factors of asthma. However, after a Bonferroni correction, only the association between asthma and atrial fibrillation remained robust.

Conclusion

The MR study revealed that asthma is a predominant risk of atrial fibrillation in European individuals, consistent with most experimental and observational studies. Whether AD affects other CVD and the causality between them needs further investigation.

Evolving concepts in the pathophysiology of atherosclerosis: from endothelial dysfunction to thrombus formation through multiple shades of inflammation

Atherosclerosis is the anatomo-pathological substrate of most cardio, cerebro and vascular diseases such as acute and chronic coronary syndromes, stroke and peripheral artery diseases. The pathophysiology of atherosclerotic plaque and its complications are under continuous investigation. In the last 2 decades our understanding on the formation, progression and complication of the atherosclerotic lesion has greatly improved and the role of immunity and inflammation is now well documented and accepted. The conventional risk factors modulate endothelial function determining the switch to a proatherosclerotic phenotype. From this point, lipid accumulation with an imbalance from cholesterol influx and efflux, foam cells formation, T-cell activation, cytokines release and matrix-degrading enzymes production occur. Lesions with high inflammatory rate become vulnerable and prone to rupture. Once complicated, the intraplaque thrombogenic material, such as the tissue factor, is exposed to the flowing blood, thus inducing coagulation cascade activation, platelets aggregation and finally intravascular thrombus formation that leads to clinical manifestations of this disease. Nonconventional risk factors, such as gut microbiome, are emerging novel markers of atherosclerosis. Several data indicate that gut microbiota may play a causative role in formation, progression and complication of atherosclerotic lesions. The gut dysbiosis-related inflammation and gut microbiota-derived metabolites have been proposed as the main working hypothesis in contributing to disease formation and progression. The current evidence suggest that the conventional and nonconventional risk factors may modulate the degree of inflammation of the atherosclerotic lesion, thus influencing its final fate. Based on this hypothesis, targeting inflammation seems to be a promising approach to further improve our management of atherosclerotic-related diseases.

Insights into the toxicological effects of nanomaterials on atherosclerosis: mechanisms involved and influence factors

Atherosclerosis is one of the most common types of cardiovascular disease and is driven by lipid accumulation and chronic inflammation in the arteries, which leads to stenosis and thrombosis. Researchers have been working to design multifunctional nanomedicines with the ability to target, diagnose, and treat atherosclerosis, but recent studies have also identified that nanomaterials can cause atherosclerosis. Therefore, this review aims to outline the molecular mechanisms and physicochemical properties of nanomaterials that promote atherosclerosis. By analyzing the toxicological effects of nanomaterials on cells involved in the pathogenesis of atherosclerosis such as vascular endothelial cells, vascular smooth muscle cells and immune cells, we aim to provide new perspectives for the prevention and treatment of atherosclerosis, and raise awareness of nanotoxicology to advance the clinical translation and sustainable development of nanomaterials.

Atherosclerosis and Inflammation: Insights from the Theory of General Pathological Processes

Recent advances have greatly improved our understanding of the molecular mechanisms behind atherosclerosis pathogenesis. However, there is still a need to systematize this data from a general pathology perspective, particularly with regard to atherogenesis patterns in the context of both canonical and non-classical inflammation types. In this review, we analyze various typical phenomena and outcomes of cellular pro-inflammatory stress in atherosclerosis, as well as the role of endothelial dysfunction in local and systemic manifestations of low-grade inflammation. We also present the features of immune mechanisms in the development of productive inflammation in stable and unstable plaques, along with their similarities and differences compared to canonical inflammation. There are numerous factors that act as inducers of the inflammatory process in atherosclerosis, including vascular endothelium aging, metabolic dysfunctions, autoimmune, and in some cases, infectious damage factors. Life-critical complications of atherosclerosis, such as cardiogenic shock and severe strokes, are associated with the development of acute systemic hyperinflammation. Additionally, critical atherosclerotic ischemia of the lower extremities induces paracoagulation and the development of chronic systemic inflammation. Conversely, sepsis, other critical conditions, and severe systemic chronic diseases contribute to atherogenesis. In summary, atherosclerosis can be characterized as an independent form of inflammation, sharing similarities but also having fundamental differences from low-grade inflammation and various variants of canonical inflammation (classic vasculitis).

Bruton's Tyrosine Kinase inhibition by Acalabrutinib does not affect early or advanced atherosclerotic plaque size and morphology in Ldlr-/- mice

Atherosclerosis is characterized by the accumulation of lipids and immune cells, including mast cells and B cells, in the arterial wall. Mast cells contribute to atherosclerotic plaque growth and destabilization upon active degranulation. The FcεRI-IgE pathway is the most prominent mast cell activation route. Bruton's Tyrosine Kinase (BTK) is involved in FcεRI-signaling and may be a potential therapeutic target to limit mast cell activation in atherosclerosis. Additionally, BTK is crucial in B cell development and B-cell receptor signaling. In this project, we aimed to assess the effects of BTK inhibition on mast cell activation and B cell development in atherosclerosis. In human carotid artery plaques, we showed that BTK is primarily expressed on mast cells, B cells and myeloid cells. In vitro, BTK inhibitor Acalabrutinib dose-dependently inhibited IgE mediated activation of mouse bone marrow derived mast cells. In vivo, male Ldlr^-/- mice were fed a high-fat diet for eight weeks, during which mice were treated with Acalabrutinib or control solvent. In Acalabrutinib treated mice, B cell maturation was reduced compared to control mice, showing a shift from follicular II towards follicular I B cells. Mast cell numbers and activation status were not affected. Acalabrutinib treatment did not affect atherosclerotic plaque size or morphology. In advanced atherosclerosis, where mice were first fed a high-fat diet for eight weeks before receiving treatment, similar effects were observed. Conclusively, BTK inhibition by Acalabrutinib alone did neither affect either mast cell activation nor early- and advanced atherosclerosis, despite the effects on follicular B cell maturation.

Chymase Inhibition Resolves and Prevents Deep Vein Thrombosis Without Increasing Bleeding Time in the Mouse Model

Background Deep vein thrombosis (DVT) is the primary cause of pulmonary embolism and the third most life-threatening cardiovascular disease in North America. Post-DVT anticoagulants, such as warfarin, heparin, and direct oral anticoagulants, reduce the incidence of subsequent venous thrombi. However, all currently used anticoagulants affect bleeding time at various degrees, and there is therefore a need for improved therapeutic regimens in DVT. It has recently been shown that mast cells play a crucial role in a DVT murine model. The underlying mechanism involved in the prothrombotic properties of mast cells, however, has yet to be identified. Methods and Results C57BL/6 mice and mouse mast cell protease-4 (mMCP-4) genetically depleted mice (mMCP-4 knockout) were used in 2 mouse models of DVT, partial ligation (stenosis) and ferric chloride-endothelial injury model of the inferior vena cava. Thrombus formation and impact of genetically repressed or pharmacologically (specific inhibitor TY-51469) inhibited mMCP-4 were evaluated by morphometric measurements of thrombi immunochemistry (mouse and human DVT), color Doppler ultrasound, bleeding times, and enzymatic activity assays ex vivo. Recombinant chymases, mMCP-4 (mouse) and CMA-1 (human), were used to characterize the interaction with murine and human plasmin, respectively, by mass spectrometry and enzymatic activity assays. Inhibiting mast cell-generated mMCP-4, genetically or pharmacologically, resolves and prevents venous thrombus formation in both DVT models. Inferior vena cava blood flow obstruction was observed in the stenosis model after 6 hours of ligation, in control- but not in TY-51469-treated mice. In addition, chymase inhibition had no impact on bleeding times of healthy or DVT mice. Furthermore, endogenous chymase limits plasmin activity in thrombi ex vivo. Recombinant mouse or human chymase degrades/inactivates purified plasmin in vitro. Finally, mast cell-containing immunoreactive chymase was identified in human DVT. Conclusions This study identified a major role for mMCP-4, a granule-localized protease of chymase type, in DVT formation. These findings support a novel pharmacological strategy to resolve or prevent DVT without affecting the coagulation cascade through the inhibition of chymase activity.

Exploring the Role of Serotonin as an Immune Modulatory Component in Cardiovascular Diseases

Serotonin, also known as 5-hydroxytryptamine (5-HT) is a well-known neurotransmitter in the central nervous system (CNS), but also plays a significant role in peripheral tissues. There is a growing body of evidence suggesting that serotonin influences immune cell responses and contributes to the development of pathological injury in cardiovascular diseases, such as atherosclerosis, as well as other diseases which occur as a result of immune hyperactivity. In particular, high levels of serotonin are able to activate a multitude of 5-HT receptors found on the surface of immune cells, thereby influencing the process of atherosclerotic plaque formation in arteries. In this review, we will discuss the differences between serotonin production in the CNS and the periphery, and will give a brief outline of the function of serotonin in the periphery. In this context, we will particularly focus on the effects of serotonin on immune cells related to atherosclerosis and identify caveats that are important for future research.

Probabilistic integration of transcriptome-wide association studies and colocalization analysis identifies key molecular pathways of complex traits

Integrative genetic association methods have shown great promise in post-GWAS (genome-wide association study) analyses, in which one of the most challenging tasks is identifying putative causal genes and uncovering molecular mechanisms of complex traits. Recent studies suggest that prevailing computational approaches, including transcriptome-wide association studies (TWASs) and colocalization analysis, are individually imperfect, but their joint usage can yield robust and powerful inference results. This paper presents INTACT, a computational framework to integrate probabilistic evidence from these distinct types of analyses and implicate putative causal genes. This procedure is flexible and can work with a wide range of existing integrative analysis approaches. It has the unique ability to quantify the uncertainty of implicated genes, enabling rigorous control of false-positive discoveries. Taking advantage of this highly desirable feature, we further propose an efficient algorithm, INTACT-GSE, for gene set enrichment analysis based on the integrated probabilistic evidence. We examine the proposed computational methods and illustrate their improved performance over the existing approaches through simulation studies. We apply the proposed methods to analyze the multi-tissue eQTL data from the GTEx project and eight large-scale complex- and molecular-trait GWAS datasets from multiple consortia and the UK Biobank. Overall, we find that the proposed methods markedly improve the existing putative gene implication methods and are particularly advantageous in evaluating and identifying key gene sets and biological pathways underlying complex traits.

The sex-dependent response to psychosocial stress and ischaemic heart disease

Stress is an important risk factor for modern chronic diseases, with distinct influences in males and females. The sex specificity of the mammalian stress response contributes to the sex-dependent development and impacts of coronary artery disease (CAD). Compared to men, women appear to have greater susceptibility to chronic forms of psychosocial stress, extending beyond an increased incidence of mood disorders to include a 2- to 4-fold higher risk of stress-dependent myocardial infarction in women, and up to 10-fold higher risk of Takotsubo syndrome-a stress-dependent coronary-myocardial disorder most prevalent in post-menopausal women. Sex differences arise at all levels of the stress response: from initial perception of stress to behavioural, cognitive, and affective responses and longer-term disease outcomes. These fundamental differences involve interactions between chromosomal and gonadal determinants, (mal)adaptive epigenetic modulation across the lifespan (particularly in early life), and the extrinsic influences of socio-cultural, economic, and environmental factors. Pre-clinical investigations of biological mechanisms support distinct early life programming and a heightened corticolimbic-noradrenaline-neuroinflammatory reactivity in females vs. males, among implicated determinants of the chronic stress response. Unravelling the intrinsic molecular, cellular and systems biological basis of these differences, and their interactions with external lifestyle/socio-cultural determinants, can guide preventative and therapeutic strategies to better target coronary heart disease in a tailored sex-specific manner.

Atherosclerosis: The Involvement of Immunity, Cytokines and Cells in Pathogenesis, and Potential Novel Therapeutics

As a leading contributor to coronary artery disease (CAD) and stroke, atherosclerosis has become one of the major cardiovascular diseases (CVD) negatively impacting patients worldwide. The endothelial injury is considered to be the initial step of the development of atherosclerosis, resulting in immune cell migration and activation as well as inflammatory factor secretion, which further leads to acute and chronic inflammation. In addition, the inflammation and lipid accumulation at the lesions stimulate specific responses from different types of cells, contributing to the pathological progression of atherosclerosis. As a result, recent studies have focused on using molecular biological approaches such as gene editing and nanotechnology to mediate cellular response during atherosclerotic development for therapeutic purposes. In this review, we systematically discuss inflammatory pathogenesis during the development of atherosclerosis from a cellular level with a focus on the blood cells, including all types of immune cells, together with crucial cells within the blood vessel, such as smooth muscle cells and endothelial cells. In addition, the latest progression of molecular-cellular based therapy for atherosclerosis is also discussed. We hope this review article could be beneficial for the clinical management of atherosclerosis.

Therapeutic potential of paeoniflorin in atherosclerosis: A cellular action and mechanism-based perspective

Epidemiological studies have shown that the incidence, prevalence and mortality of atherosclerotic cardiovascular disease (ASCVD) are increasing globally. Atherosclerosis is characterized as a chronic inflammatory disease which involves inflammation and immune dysfunction. P. lactiflora Pall. is a plant origin traditional medicine that has been widely used for the treatment of various diseases for more than a millennium in China, Japan and Korean. Paeoniflorin is a bioactive monomer extracted from P. lactiflora Pall. with anti-atherosclerosis effects. In this article, we comprehensively reviewed the potential therapeutic effects and molecular mechanism whereby paeoniflorin protects against atherosclerosis from the unique angle of inflammation and immune-related pathway dysfunction in vascular endothelial cells, smooth muscle cells, monocytes, macrophages, platelets and mast cells. Paeoniflorin, with multiple protective effects in atherosclerosis, has the potential to be used as a promising therapeutic agent for the treatment of atherosclerosis and its complications. We conclude with a detailed discussion of the challenges and future perspective of paeoniflorin in translational cardiovascular medicine.

The impact of type 2 immunity and allergic diseases in atherosclerosis

Allergic diseases are allergen-induced immunological disorders characterized by the development of type 2 immunity and IgE responses. The prevalence of allergic diseases has been on the rise alike cardiovascular disease (CVD), which affects arteries of different organs such as the heart, the kidney and the brain. The underlying cause of CVD is often atherosclerosis, a disease distinguished by endothelial dysfunction, fibrofatty material accumulation in the intima of the artery wall, smooth muscle cell proliferation, and Th1 inflammation. The opposed T-cell identity of allergy and atherosclerosis implies an atheroprotective role for Th2 cells by counteracting Th1 responses. Yet, the clinical association between allergic disease and CVD argues against it. Within, we review different phases of allergic pathology, basic immunological mechanisms of atherosclerosis and the clinical association between allergic diseases (particularly asthma, atopic dermatitis, allergic rhinitis and food allergy) and CVD. Then, we discuss putative atherogenic mechanisms of type 2 immunity and allergic inflammation including acute allergic reactions (IgE, IgG1, mast cells, macrophages and allergic mediators such as vasoactive components, growth factors and those derived from the complement, contact and coagulation systems) and late phase inflammation (Th2 cells, eosinophils, type 2 innate-like lymphoid cells, alarmins, IL-4, IL-5, IL-9, IL-13 and IL-17).

Plaque rupture and neovascularisation detected with optical coherence tomography in a case of Kounis syndrome

Kounis syndrome is an allergic acute coronary syndrome (ACS) characterised by coronary artery spasm, plaque erosion/rupture or stent thrombosis caused by mast cell and other interacting cell activation. Although intracoronary imaging modalities can detect those ACS mechanisms, Kounis syndrome due to plaque rupture has rarely been reported using intracoronary imaging. We present the case of a woman in her 70s who developed Kounis syndrome as a result of plaque rupture detected with optical coherence tomography (OCT). She had non-ST-segment elevation ACS as a result of anaphylaxis to cefazolin. Coronary angiography revealed severe stenosis in the left anterior descending artery; angiographically undetectable plaque rupture was detected using OCT. OCT also revealed intraplaque neovascularisation, suggesting that the culprit plaque had been vulnerable. OCT can aid in understanding the underlying mechanisms of Kounis syndrome.

A review on therapeutical potential of paeonol in atherosclerosis

The morbidity and mortality of atherosclerotic cardiovascular disease (ASCVD) is increasing year by year. Cortex Moutan is a traditional Chinese medicinal herb that has been widely used for thousands of years to treat a wide variety of diseases in Eastern countries due to its heat-clearing and detoxifying effects. Paeonol is a bioactive monomer extracted from Cortex Moutan, which has anti-atherosclerotic effects. In this article, we reviewed the pharmacological effects of paeonol against experimental atherosclerosis, as well as its protective effects on vascular endothelial cells, smooth muscle cells, macrophages, platelets, and other important cell types. The pleiotropic effects of paeonol in atherosclerosis suggest that it can be a promising therapeutic agent for atherosclerosis and its complications. Large-scale randomized clinical trials are warranted to elucidate whether paeonol are effective in patients with ASCVD.

Nuclear receptor NOR-1 (Neuron-derived Orphan Receptor-1) in pathological vascular remodelling and vascular remodelling

Vascular cells and their interaction with inflammatory cells and the immune system play a key role in pathological vascular remodeling. A large number of genes and proteins regulated in a coordinated manner by a small number of transcription factors are involved in this process. In recent years, research on a small subfamily of transcription factors, the NR4A subfamily, has had a major impact on our understanding of vascular biology. The NR4A1 (Nur77), NR4A2 (Nurr1) and NR4A3 (NOR-1) receptors are products of early response genes whose expression is induced by multiple pathophysiological and physical stimuli. Their wide distribution in different tissues and cells places them in the control of numerous processes such as cell differentiation, proliferation, survival and apoptosis, as well as inflammation and the metabolism of lipids and carbohydrates. This review analyzes the role of these receptors, particularly NOR-1, in pathological vascular remodeling associated with atherosclerosis, abdominal aortic aneurysm and pulmonary arterial hypertension.

Lymphocytic myocarditis presenting as acute myocardial infarction: a case report and review of the literature

We report a case that presented as acute myocardial infarction (AMI) caused by lymphocytic myocarditis (LM), and explore the relationship between AMI and LM. We also performed a literature search to identify publications that previously reported LM-associated myocardial infarction. Coronary angiography of our patient revealed normal coronary arteries. However, a perfusion-metabolism mismatch in the apex and mid-inferior walls supported the diagnosis of AMI, and right ventricular septal endomyocardial biopsy showed LM. Extensive viral serological tests were negative for an infectious etiology. Immunosuppressive therapy may be beneficial in patients with high-risk myocarditis who are pathologically confirmed to be virus-negative.

Analysis of Immune and Inflammation Characteristics of Atherosclerosis from Different Sample Sources

Background

Atherosclerosis is the predominant cause of cardiovascular diseases. Existing studies suggest that the development of atherosclerosis is closely related to inflammation and immunity, but whether there are differences and similarities between atherosclerosis occurring at different sites is still unknown. We elucidated the pathological characteristics of peripheral vascular diseases by using bioinformatic analyses on immune cells and inflammation-related gene expression in atherosclerotic arteries and plaques.

Methods

Eight data sets regarding atherosclerosis were downloaded from the Gene Expression Omnibus database. Human immune genes were obtained from the IMMPORT website. The samples were scored and divided into high- and low-immune groups. Then the samples were analysed using weighted gene co-expression network analysis, while the modules were analysed using functional enrichment. The protein–protein interaction network was constructed using the STRING and Cytoscape databases. The hub immune genes were screened, and the correlation between hub immune genes and immune cells was analysed.

Results

Immune cells and their functions were significantly different during atherosclerosis development. The infiltration proportion of immune cells was approximately similar in samples from different sources of patients with carotid atherosclerosis. However, the sensitivity of lower extremity atherosclerosis samples to immune cells is lower than that of carotid atherosclerosis samples.The samples from the plaque and artery were mainly infiltrated by macrophages, T cells and mast cells. After immune cells were assessed, resting NK cells, activated mast cells and M0 macrophages were found to be key immune cells in atherosclerosis and plaque formation. In addition, CCL4, TLR2, IL1B and PTPRC were considered to be immune marker genes in atherosclerosis development. Conclusion. Bioinformatic data analysis confirms the essential role of immune cells in cardiovascular diseases, and also indicates some differences of immune and inflammation characteristics of atherosclerosis between carotid and lower extremity arteries.

Atherosclerosis and multi-organ-associated pathologies

Atherosclerosis is a chronic inflammatory disease of the vascular system that is characterized by the deposition of modified lipoproteins, accumulation of immune cells, and formation of fibrous tissue within the vessel wall. The disease occurs in vessels throughout the body and affects the functions of almost all organs including the lymphoid system, bone marrow, heart, brain, pancreas, adipose tissue, liver, kidneys, and gastrointestinal tract. Atherosclerosis and associated factors influence these tissues via the modulation of local vascular functions, induction of cholesterol-associated pathologies, and regulation of local immune responses. In this review, we discuss how atherosclerosis interferers with functions of different organs via several common pathways and how the disturbance of immunity in atherosclerosis can result in disease-provoking dysfunctions in multiple tissues. Our growing appreciation of the implication of atherosclerosis and associated microenvironmental conditions in the multi-organ pathology promises to influence our understanding of CVD-associated disease pathologies and to provide new therapeutic opportunities.

Ocular surface mast cells promote inflammatory lymphangiogenesis

Mast cells, sentinel immune cells, are most abundantly expressed in vascularized tissues that interface the external environment, such as the skin and ocular surface. Our previous reports have shown mast cells reside closely with vascular endothelial cells and mediate the pathogenic angiogenic response. However, the contribution of mast cells and their underlying mechanisms on lymphangiogenesis have not been fully deciphered. Using a murine model of inflammatory corneal angiogenesis, we observed adjacent migration of activated mast cells with new lymph vessel growth. Our in vitro co-culture assays demonstrate that mast cells express high levels of of VEGF-D and directly promote lymphatic endothelial cell tube formation and proliferation. Moreover, our loss-of-function approaches, using mast cell knockout mice and cromolyn-mediated mast cell inhibition, showed mast cell deficiency suppresses the induction of inflammatory lymphangiogenesis and VEGF-D expression at the ocular surface following corneal tissue insult. Our findings suggest blockade of mast cells as a potential therapeutic strategy to inhibit pathological lymphangiogenesis.

Innate and adaptive immunity: the understudied driving force of heart valve disease

Calcific aortic valve disease (CAVD), and its clinical manifestation that is calcific aortic valve stenosis, is the leading cause for valve disease within the developed world, with no current pharmacological treatment available to delay or halt its progression. Characterized by progressive fibrotic remodelling and subsequent pathogenic mineralization of the valve leaflets, valve disease affects 2.5% of the western population, thus highlighting the need for urgent intervention. Whilst the pathobiology of valve disease is complex, involving genetic factors, lipid infiltration, and oxidative damage, the immune system is now being accepted to play a crucial role in pathogenesis and disease continuation. No longer considered a passive degenerative disease, CAVD is understood to be an active inflammatory process, involving a multitude of pro-inflammatory mechanisms, with both the adaptive and the innate immune system underpinning these complex mechanisms. Within the valve, 15% of cells evolve from haemopoietic origin, and this number greatly expands following inflammation, as macrophages, T lymphocytes, B lymphocytes, and innate immune cells infiltrate the valve, promoting further inflammation. Whether chronic immune infiltration or pathogenic clonal expansion of immune cells within the valve or a combination of the two is responsible for disease progression, it is clear that greater understanding of the immune systems role in valve disease is required to inform future treatment strategies for control of CAVD development.

Androgen-dependent tissue factor pathway inhibitor regulating protein: a review of its peripheral actions and association with cardiometabolic diseases

The first genome-wide association study on coronary artery disease (CAD) in the Han Chinese population identified C6orf105 as a susceptibility gene. The C6orf105 gene was later found to encode for a protein that regulates tissue factor pathway inhibitor (TFPI) expression in endothelial cells in an androgen-dependent manner, and the novel protein was thus termed androgen-dependent TFPI-regulating protein (ADTRP). Since the identification of ADTRP, there have been several studies associating genetic variants on the ADTRP gene with CAD risk, as well as research providing mechanistic insights on this novel protein and its functional role. ADTRP is a membrane protein, whose expression is upregulated by androgen, GATA-binding protein 2, oxidized low-density lipoprotein, peroxisome proliferator-activated receptors, and low-density lipoprotein receptors. ADTRP regulates multiple downstream targets involved in coagulation, inflammation, endothelial function, and vascular integrity. In addition, ADTRP functions as a fatty acid esters of hydroxy fatty acid (FAHFA)-specific hydrolase that is involved in energy metabolism. Current evidence suggests that ADTRP may play a role in the pathogenesis of atherosclerosis, CAD, obesity, and metabolic disorders. This review summarizes the current literature on ADTRP, with a focus on the peripheral actions of ADTRP, including expression, genetic variations, signaling pathways, and function. The evidence linking ADTRP and cardiometabolic diseases will also be discussed.

NR4A3: A Key Nuclear Receptor in Vascular Biology, Cardiovascular Remodeling, and Beyond

The mechanisms committed in the activation and response of vascular and inflammatory immune cells play a major role in tissue remodeling in cardiovascular diseases (CVDs) such as atherosclerosis, pulmonary arterial hypertension, and abdominal aortic aneurysm. Cardiovascular remodeling entails interrelated cellular processes (proliferation, survival/apoptosis, inflammation, extracellular matrix (ECM) synthesis/degradation, redox homeostasis, etc.) coordinately regulated by a reduced number of transcription factors. Nuclear receptors of the subfamily 4 group A (NR4A) have recently emerged as key master genes in multiple cellular processes and vital functions of different organs, and have been involved in a variety of high-incidence human pathologies including atherosclerosis and other CVDs. This paper reviews the major findings involving NR4A3 (Neuron-derived Orphan Receptor 1, NOR-1) in the cardiovascular remodeling operating in these diseases.

Single-Cell Transcriptomic Atlas of Different Human Cardiac Arteries Identifies Cell Types Associated With Vascular Physiology

[Figure: see text].

Basophil Blood Cell Count Is Associated With Enhanced Factor II Plasma Coagulant Activity and Increased Risk of Mortality in Patients With Stable Coronary Artery Disease: Not Only Neutrophils as Prognostic Marker in Ischemic Heart Disease

Background White blood cell count, which is inexpensive and widely available in clinical practice, has been proposed to provide prognostic information in coronary artery disease (CAD). Elevated levels of white blood cell subtypes may play different roles in atherothrombosis and predict cardiovascular outcomes. Methods and Results The association between white blood cell counts and mortality was evaluated in 823 subjects with angiographically demonstrated and clinically stable CAD in an observational-longitudinal study. The correlation among white blood cell counts and factor II plasma coagulant activity was analyzed in 750 subjects (554 CAD and 196 CAD-free) not taking anticoagulant drugs. Subjects with overt leukocytosis or leukopenia were excluded. In the longitudinal study after a median follow-up of 61 months, 160 (19.4%) subjects died, 107 (13.0%) of whom from cardiovascular causes. High levels of neutrophils, monocytes, eosinophils, and basophils were associated with an increased mortality rate. In multiadjusted Cox regression models, only neutrophils and basophils remained predictors of total and cardiovascular mortality. The associations remained significant after adjustment for traditional cardiovascular risk factors and by including D-dimer and the chemokine CXCL12 in the regression models. Neutrophils and basophils were also significant predictors of factor II plasma coagulant activity variability after adjustment for blood cell counts, age, sex, inflammatory markers, CAD diagnosis, and prothrombin G20210A polymorphism. Factor II plasma coagulant activity was similarly increased in subjects with high neutrophil and basophil counts and in carriers of the prothrombin 20210A allele. Conclusions Both high neutrophil and basophil blood counts may predict mortality in patients with clinically stable CAD and are associated with enhanced factor II plasma coagulant activity, thereby suggesting underlying prothrombotic mechanisms.

Novel Strategies to Target Mast Cells in Disease

Mast cells (MCs) are versatile effector cells of the immune system, characterized by a large content of secretory granules containing a variety of inflammatory mediators. They are implicated in the host protection toward various external insults, but are mostly well known for their detrimental impact on a variety of pathological conditions, including allergic disorders such as asthma and a range of additional disease settings. Based on this, there is currently a large demand for therapeutic regimens that can dampen the detrimental impact of MCs in these respective pathological conditions. This can be accomplished by several strategies, including targeting of individual mediators released by MCs, blockade of receptors for MC-released compounds, inhibition of MC activation, limiting mast cell growth or by inducing mast cell apoptosis. Here, we review the currently available and emerging regimens to interfere with harmful mast cell activities in asthma and other pathological settings and discuss the advantages and limitations of such strategies.

Role of the α7 Nicotinic Acetylcholine Receptor in the Pathophysiology of Atherosclerosis

Atherosclerosis constitutes a major risk factor for cardiovascular diseases, the leading cause of morbidity and mortality worldwide. This slowly progressing, chronic inflammatory disorder of large- and medium-sized arteries involves complex recruitment of immune cells, lipid accumulation, and vascular structural remodeling. The α7 nicotinic acetylcholine receptor (α7nAChR) is expressed in several cell types involved in the genesis and progression of atherosclerosis, including macrophages, dendritic cells, T and B cells, vascular endothelial and smooth muscle cells (VSMCs). Recently, the α7nAChR has been described as an essential regulator of inflammation as this receptor mediates the inhibition of cytokine synthesis through the cholinergic anti-inflammatory pathway, a mechanism involved in the attenuation of atherosclerotic disease. Aside from the neuronal cholinergic control of inflammation, the non-neuronal cholinergic system similarly regulates the immune function. Acetylcholine released from T cells acts in an autocrine/paracrine fashion at the α7nAChR of various immune cells to modulate immune function. This mechanism additionally has potential implications in reducing atherosclerotic plaque formation. In contrast, the activation of α7nAChR is linked to the induction of angiogenesis and VSMC proliferation, which may contribute to the progression of atherosclerosis. Therefore, both atheroprotective and pro-atherogenic roles are attributed to the stimulation of α7nAChRs, and their role in the genesis and progression of atheromatous plaque is still under debate. This minireview highlights the current knowledge on the involvement of the α7nAChR in the pathophysiology of atherosclerosis.

Nanomedicine Approaches for Advanced Diagnosis and Treatment of Atherosclerosis and Related Ischemic Diseases

Cardiovascular diseases (CVDs) remain one of the major causes of mortality worldwide. In response to this and other worldwide health epidemics, nanomedicine has emerged as a rapidly evolving discipline that involves the development of innovative nanomaterials and nanotechnologies and their applications in therapy and diagnosis. Nanomedicine presents unique advantages over conventional medicines due to the superior properties intrinsic to nanoscopic therapies. Once used mainly for cancer therapies, recently, tremendous progress has been made in nanomedicine that has led to an overall improvement in the treatment and diagnosis of CVDs. This review elucidates the pathophysiology and potential targets of atherosclerosis and associated ischemic diseases. It may be fruitful to pursue future work in the nanomedicine-mediated treatment of CVDs based on these targets. A comprehensive overview is then provided featuring the latest preclinical and clinical outcomes in cardiovascular imaging, biomarker detection, tissue engineering, and nanoscale delivery, with specific emphasis on nanoparticles, nanostructured scaffolds, and nanosensors. Finally, the challenges and opportunities regarding the future development and clinical translation of nanomedicine in related fields are discussed. Overall, this review aims to provide a deep and thorough understanding of the design, application, and future development of nanomedicine for atherosclerosis and related ischemic diseases.

Combined Extract of Vitis vinifera L. and Centella asiatica Synergistically Attenuates Oxidative Damage Induced by Hydrogen Peroxide in Human Umbilical Vein Endothelial Cells

Endothelial cell injury caused by oxidative stress is a critical factor in the initial stage of vascular diseases. Thus, identification of more effective antioxidants is a promising strategy to protect against endothelial cell injury. Recently, synergistic effects between phytochemicals have received renewed attention for their role in the treatment of various diseases. Vitis vinifera L. and Centella asiatica are well-known medicinal plants with various biological effects. However, the combination of the two has not previously been studied. Here, we investigated the effects of V. vinifera L. leaf and C. asiatica extract combination (VCEC), a standardized herbal blend comprising V. vinifera L. leaf extract (VE) and C. asiatica extract (CE), for its antioxidant activity and for the protection of endothelial cells against hydrogen peroxide (H₂O₂)-mediated oxidative damage in human umbilical vein endothelial cells (HUVECs). VCEC showed higher antioxidant activity than VE or CE in oxygen radical antioxidant capacity assays. In HUVECs, VCEC significantly suppressed increases in the production of intracellular reactive oxygen species, decreased levels of nitric oxide and vascular endothelial-cadherin, and increased endothelial hyperpermeability triggered by H₂O₂. Treatment with VE or CE alone ameliorated HUVEC injury in a pattern similar to VCEC, although their effects were significantly weaker than VCEC. Overall, VCEC exhibited a substantial synergistic effect on protecting endothelial cells against oxidative damage through its antioxidant activity. Therefore, VCEC could be developed as a potential agent for reducing the risk of vascular diseases related to oxidative stress.

An Updated Review of Pro- and Anti-Inflammatory Properties of Plasma Lysophosphatidylcholines in the Vascular System

Lysophosphatidylcholines are a group of bioactive lipids heavily investigated in the context of inflammation and atherosclerosis development. While present in plasma during physiological conditions, their concentration can drastically increase in certain inflammatory states. Lysophosphatidylcholines are widely regarded as potent pro-inflammatory and deleterious mediators, but an increasing number of more recent studies show multiple beneficial properties under various pathological conditions. Many of the discrepancies in the published studies are due to the investigation of different species or mixtures of lysophatidylcholines and the use of supra-physiological concentrations in the absence of serum or other carrier proteins. Furthermore, interpretation of the results is complicated by the rapid metabolism of lysophosphatidylcholine (LPC) in cells and tissues to pro-inflammatory lysophosphatidic acid. Interestingly, most of the recent studies, in contrast to older studies, found lower LPC plasma levels associated with unfavorable disease outcomes. Being the most abundant lysophospholipid in plasma, it is of utmost importance to understand its physiological functions and shed light on the discordant literature connected to its research. LPCs should be recognized as important homeostatic mediators involved in all stages of vascular inflammation. In this review, we want to point out potential pro- and anti-inflammatory activities of lysophospholipids in the vascular system and highlight recent discoveries about the effect of lysophosphatidylcholines on immune cells at the endothelial vascular interface. We will also look at their potential clinical application as biomarkers.

Acute Myocardial Infarction in Systemic Mastocytosis: Case Report With Literature Review on the Role of Inflammatory Process in Acute Coronary Syndrome

Background

Systemic Mastocytosis (SM) is a disorder of excessive mast cell infiltration in multiple organ tissues. Atherosclerosis is a major risk factor for developing acute coronary syndrome. In addition to lipid accumulation in the arterial wall, inflammation plays an important role in the pathogenesis of plaque rupture and activating the thrombosis cascade. The Mast cells contribution to plaque destabilization has been well established in multiple animal and human studies. In a recent study, SM has been proven to be associated with a higher incidence of acute coronary syndrome even with lower plasma lipids levels. The study showed that 20% of patients with SM had cardiovascular events compared to only 6% in the control group with adjustment to all cardiac risk factors.

Case

We presented a patient with no risk factors for heart disease other than old age and history of SM who developed acute myocardial infarction.

Conclusion

SM can be life-threatening and can result in ACS, anaphylactic reaction, syncope, or cardiac arrest. Clinicians should have a high index of suspicion of acute coronary syndrome (ACS) occurrence in the setting of inflammatory conditions, such as SM and KS, and vice versa, where SM should be considered or ruled out in patients who suffer from anaphylaxis and cardiac arrest or myocardial infarction.

Local Mast Cell Activation Promotes Neovascularization

Mast cells have been associated with arteriogenesis and collateral formation. In advanced human atherosclerotic plaques, mast cells have been shown to colocalize with plaque neovessels, and mast cells have also been associated with tumor vascularization. Based on these associations, we hypothesize that mast cells promote angiogenesis during ischemia. In human ischemic muscle tissue from patients with end-stage peripheral artery disease, we observed activated mast cells, predominantly located around capillaries. Also, in mouse ischemic muscles, mast cells were detected during the revascularization process and interestingly, mast cell activation status was enhanced up to 10 days after ischemia induction. To determine whether mast cells contribute to both arteriogenesis and angiogenesis, mast cells were locally activated immediately upon hind limb ischemia in C57Bl/6 mice. At day 9, we observed a 3-fold increase in activated mast cell numbers in the inguinal lymph nodes. This was accompanied by an increase in the amount of Ly6C^high inflammatory monocytes. Interestingly, local mast cell activation increased blood flow through the hind limb (46% at day 9) compared to that in non-activated control mice. Histological analysis of the muscle tissue revealed that mast cell activation did not affect the number of collaterals, but increased the collateral diameter, as well as the number of CD31⁺ capillaries. Together, these data illustrate that locally activated mast cell contribute to arteriogenesis and angiogenesis.

Histamine-mediated autocrine signaling in mesenteric perilymphatic mast cells

Lymphatic vessels play a critical role in mounting a proper immune response by trafficking peripheral immune cells to draining lymph nodes. Mast cells (MCs) are well known for their roles in type I hypersensitivity reactions, but little is known about their secretory regulation in the lymphatic niche. MCs, as innate sensor and effector cells, reside close to mesenteric lymphatic vessels (MLVs), and their activation and ability to release histamine influences the lymphatic microenvironment in a histamine-NF-κB-dependent manner. Using an established experimental protocol involving surgical isolation of rat mesenteric tissue segments, including MLVs and surrounding perilymphatic tissues, we tested the hypothesis that perilymphatic mesenteric MCs possess histamine receptors (HRs) that bind and respond to the histamine released from these same MCs. Under various experimental conditions, including inflammatory stimulation by LPS, we measured histamine in mesenteric perilymphatic tissues, evaluated expression of histidine decarboxylase in MCs along with the degree of MC degranulation, assessed the functional status of HRs in MCs, and evaluated the ability of histamine itself to induce MC activation. Finally, we evaluated the importance of MCs and HR1 and -2 for MLV-directed trafficking of CD11b/c-positive cells during acute tissue inflammation. Our data indicate the existence of a functionally potent MC-histamine autocrine regulatory loop, the elements of which are crucially important for acute inflammation-induced trafficking of the CD11b/c-positive cells toward MLVs. This MC-histamine loop serves as a first-line cellular servo control system, playing a key role in the innate and adaptive immune response as well as NF-κB-mediated maintenance of body homeostasis.

The role of Helicobacter pylori in cardiovascular toxicity mechanisms

Despite the long history of the concept where infection plays a significant role in cardiovascular diseases (atherosclerosis in particular), today it is relevant and represented a significant interest.

This article discusses H. pylori role in mechanisms of cardiovascular homeostasis disturbance. H. pylori involvement in atherogenic damage of arteries, and/or plaque destabilization is no doubt. This vidence is detailed in this review article.