Low density lipoprotein undergoes oxidative modification in vivo

Feeding lambs hazelnut skin and linseed decreases meat lipid oxidation during in vitro digestion

The present study aimed to evaluate the effect of the inclusion in lamb diet of hazelnut skin (H diet), extruded linseed (L diet), or a combination thereof (HL diet) on the oxidative stability of cooked and in vitro digested lamb meat compared to a basal diet (C diet). A significant decrease of 46.1 % and 40.9 % in lipid hydroperoxides was attended after in vitro digestion in lamb meat from the L and H diets with respect to C diet. Moreover, the HL diet was the most effective in decreasing the TBA-RS value after intestinal digestion (23.3 % decrease compared to C diet). Five different phenolic- and four tocopherol-derived metabolites were identified whose amount was greater in meat from supplemented diets. Furthermore, the inclusion of hazelnut skin in the lamb diet resulted in higher amount of endogenous antioxidants (carnosine and reduced glutathione) in raw meat.

Severity and Risk Factors Associated with Premature Coronary Artery Disease in Patients Under the Age of 50 in Saudi Population: A Retrospective Study

Background and Objectives: The average age of presentation of coronary artery disease (CAD) is one decade younger in the Saudi population relative to other patients worldwide. It is imperative to investigate the prevalence of premature coronary artery disease (PCAD) risk factors in Saudi Arabia's younger population in order to prevent the incidence of cardiovascular diseases in the future. Thus, the present study aimed to evaluate the severity and identify the risk factors associated with PCAD in patients under the age of 50 at King Saud University Medical City (KSUMC), Saudi Arabia. Methods: This observational retrospective study was conducted between June 2022 and June 2023 at King Saud University Medical City, Riyadh, Saudi Arabia. A total of 718 participants were included in the study. The patients, confirmed by electrocardiographic and/or angiographic findings of coronary artery disease, were divided into three age groups: group 1 (<40 years), group 2 (40-45 years), and group 3 (45-50 years). The severity of vessel occlusions was evaluated using the Gensini scoring system. Electrocardiographic findings, sociodemographic variables, and risk factors were also taken into consideration. Results: The mean age of patients in group 1 was 35.2 ± 4.5 years, in group 2 was 43.0 ± 1.3 years, and in group 3 was 48.4 ± 1.4 years. Patients in group 2 had a significantly higher BMI (31.3 ± 10.5) compared to patients in group 3 (29.4 ± 5.3; p = 0.015). Nearly 55% of patients under 40 years had 2 or 3 vessel occlusions according to the vessel score. The percentage of patients with inferior ST elevation was significantly higher in group 1 (<40 years, 11.2%) compared to groups 2 (40-45 years, 10.1%) and 3 (45-50 years, 6.0%; p = 0.001). Non-specific ST-T changes were more common in group 1 (31.4%) and group 2 (32.0%) compared to group 3 (28.4%). Although not statistically significant, left main artery occlusion tended to be higher in group 3 (8.6%) compared to groups 1 (4.6%) and 2 (4.5%; p = 0.229). Hyperlipidemia levels were significantly higher in patients with a Gensini score > 39 compared to those with a Gensini score < 39 (47.9% vs. 37.5%, respectively; p = 0.05). The prevalence of smoking was about 54% in group 1, followed by type 2 diabetes mellitus, dyslipidemia, and hypertension (37%, 36%, and 33%, respectively). Conclusions: This study suggested that PCAD Saudi patients below 40 years of age had a higher percentage of inferior ST elevation compared to older patients, while non-specific ST-T changes were significantly higher in older patients. Astonishingly, more than 50% of patients in all groups had two or three vessel occlusions. There was a high prevalence of modifiable risk factors, such as smoking, in younger patients, whereas hyperlipidemia was a risk factor for PCAD in all age groups. In addition, hyperlipidemia was highly correlated with severe vessel occlusion according to the Gensini score. Therefore, early preventive measures should be taken into consideration to reduce the future burden of cardiovascular complications in this population.

Overview of Clinical Relevance of Antibodies Against Oxidized Low-Density Lipoprotein (oLAb) Within Three Decades by ELISA Technology

One of the most prominent actions of oxidative stress is the attack of free radicals on poylyunsaturated fatty acids (PUFAs), initiating a chain reaction to modify these PUFAs and generate oxidized modifications on all biomolecules. In the last quarter of the 20th century, intensive research was carried out to identify antibodies against such modifications. In the mid-1990s, the first enzyme-linked immunosorbent assay (ELISA) was introduced to the market, significantly accelerating research activities and knowledge gain. During this pioneering period, the main focus was on cardiovascular diseases, cancer, diabetes, and other diseases associated with oxidative stress. Subsequently, a standard range of these antibodies against oxidized LDL (oLAb) was determined in the population. Furthermore, the impact of exhaustive physical activity and diet on oLAb titers, and the correlation between newborns and mothers after delivery, as well as nutritional intake in newborns, were evaluated. Subsequently, the harmful effects of smoking and many other areas regarding oLAb titer were published, resulting in novel approaches for prognostic and therapeutic options, in particular through studies with antioxidants, which were able to influence oLAb significantly. This review presents an overview of the research activities obtained with this ELISA over the past three decades.

The Efficacy of Vitamins in the Prevention and Treatment of Cardiovascular Disease

Vitamins are known to affect the regulation of several biochemical and metabolic pathways that influence cellular function. Adequate amounts of both hydrophilic and lipophilic vitamins are required for maintaining normal cardiac and vascular function, but their deficiencies can contribute to cardiovascular abnormalities. In this regard, a deficiency in the lipophilic vitamins, such as vitamins A, D, and E, as well as in the hydrophilic vitamins, such as vitamin C and B, has been associated with suboptimal cardiovascular function, whereas additional intakes have been suggested to reduce the risk of atherosclerosis, hypertension, ischemic heart disease, arrhythmias, and heart failure. Here, we have attempted to describe the association between low vitamin status and cardiovascular disease, and to offer a discussion on the efficacy of vitamins. While there are inconsistencies in the impact of a deficiency in vitamins on the development of cardiovascular disease and the benefits associated with supplementation, this review proposes that specific vitamins may contribute to the prevention of cardiovascular disease in individuals at risk rather than serve as an adjunct therapy.

Human In Vitro Oxidized Low-Density Lipoprotein (oxLDL) Increases Urinary Albumin Excretion in Rats

Hypercholesterolemia-associated oxidative stress increases the formation of oxidized low-density lipoprotein (oxLDL), which can affect endothelial cell function and potentially contribute to renal dysfunction, as reflected by changes in urinary protein excretion. This study aimed to investigate the impact of exogenous oxLDL on urinary excretion of albumin and nephrin. LDL was isolated from a patient with familial hypercholesterolemia (FH) undergoing lipoprotein apheresis (LA) and was oxidized in vitro with Cu (II) ions. Biochemical markers of LDL oxidation, such as TBARS, conjugated dienes, and free ε-amino groups, were measured. Wistar rats were treated with a single intraperitoneal injection of PBS, LDL, or oxLDL (4 mg of protein/kg b.w.). Urine was collected one day before and two days after the injection. We measured blood lipid profiles, urinary protein excretion (specifically albumin and nephrin), and markers of systemic oxidative stress (8-OHdG and 8-iso-PGF2α). The results showed that injection of oxLDL increased urinary albumin excretion by approximately 28% (310 ± 27 μg/24 h vs. 396 ± 26 μg/24 h, p = 0.0003) but had no effect on nephrin excretion. Neither PBS nor LDL had any effect on urinary albumin or nephrin excretion. Additionally, oxLDL did not affect systemic oxidative stress. In conclusion, hypercholesterolemia may adversely affect renal function through oxidatively modified LDL, which interferes with the renal handling of albumin and leads to the development of albuminuria.

The Intersection of Genetic Factors, Aberrant Nutrient Metabolism and Oxidative Stress in the Progression of Cardiometabolic Disease

Cardiometabolic disease (CMD), which encompasses metabolic-associated fatty liver disease (MAFLD), chronic kidney disease (CKD) and cardiovascular disease (CVD), has been increasing considerably in the past 50 years. CMD is a complex disease that can be influenced by genetics and environmental factors such as diet. With the increased reliance on processed foods containing saturated fats, fructose and cholesterol, a mechanistic understanding of how these molecules cause metabolic disease is required. A major pathway by which excessive nutrients contribute to CMD is through oxidative stress. In this review, we discuss how oxidative stress can drive CMD and the role of aberrant nutrient metabolism and genetic risk factors and how they potentially interact to promote progression of MAFLD, CVD and CKD. This review will focus on genetic mutations that are known to alter nutrient metabolism. We discuss the major genetic risk factors for MAFLD, which include Patatin-like phospholipase domain-containing protein 3 (PNPLA3), Membrane Bound O-Acyltransferase Domain Containing 7 (MBOAT7) and Transmembrane 6 Superfamily Member 2 (TM6SF2). In addition, mutations that prevent nutrient uptake cause hypercholesterolemia that contributes to CVD. We also discuss the mechanisms by which MAFLD, CKD and CVD are mutually associated with one another. In addition, some of the genetic risk factors which are associated with MAFLD and CVD are also associated with CKD, while some genetic risk factors seem to dissociate one disease from the other. Through a better understanding of the causative effect of genetic mutations in CMD and how aberrant nutrient metabolism intersects with our genetics, novel therapies and precision approaches can be developed for treating CMD.

Free Radical Lipid Peroxidation Induced by Reactive Halogen Species

The review is devoted to the mechanisms of free radical lipid peroxidation (LPO) initiated by reactive halogen species (RHS) produced in mammals, including humans, by heme peroxidase enzymes, primarily myeloperoxidase (MPO). It has been shown that RHS can participate in LPO both in the initiation and branching steps of the LPO chain reactions. The initiation step of RHS-induced LPO mainly involves formation of free radicals in the reactions of RHS with nitrite and/or with amino groups of phosphatidylethanolamine or Lys. The branching step of the oxidative chain is the reaction of RHS with lipid hydroperoxides, in which peroxyl and alkoxyl radicals are formed. The role of RHS-induced LPO in the development of human inflammatory diseases (cardiovascular and neurodegenerative diseases, cancer, diabetes, rheumatoid arthritis) is discussed in detail.

Atherosclerosis antigens as targets for immunotherapy

Atherosclerosis is a chronic inflammatory disease of the arteries that can lead to thrombosis, infarction and stroke, underlying the first cause of mortality worldwide. Adaptive immunity plays critical roles in atherosclerosis, and numerous studies have ascribed both atheroprotective and atherogenic functions to specific subsets of T and B cells. However, less is known on how antigen specificity determines the protective or adverse outcome of such adaptive responses. Understanding antigen triggers in atherosclerosis is crucial to delve deeper into mechanisms of disease initiation and progression and to implement specific immunotherapeutic approaches, including vaccination strategies. Here we review the role of adaptive immunity in atherosclerosis and the insights that single-cell technology has provided into the function of distinct immune cell subsets. We outline the most relevant atherosclerosis antigens and antibodies reported to date and examine their immunotherapeutic potential. Finally, we review the most promising vaccination-based clinical trials targeting the adaptive immune system.

Immunomodulation Therapies for Atherosclerosis: The Past, the Present, and the Future

Atherosclerotic cardiovascular disease is the most common cause of morbidity and death worldwide. Recent studies have demonstrated that this chronic inflammatory disease of the arterial wall can be controlled through the modulation of immune system activity. Many patients with cardiovascular disease remain at elevated risk of recurrent events despite receiving current, state-of-the-art preventive medical treatment. Much of this residual risk is attributed to inflammation. Therefore, finding new treatment strategies for this category of patients became of common interest. This review will discuss the experimental and clinical data supporting the possibility of developing immune-based therapies for lowering cardiovascular risk, explicitly focusing on vaccination strategies.

Targeting leukotriene biosynthesis to prevent atherosclerotic cardiovascular disease

Atherosclerotic cardiovascular disease (ASCVD) is the leading cause of death and disability worldwide. As such, new treatments are needed to prevent the onset and progression of atherosclerosis to improve outcomes in patients with coronary, cerebrovascular, and peripheral arterial disease. In this regard, inflammation is known to be a critical driver of atherosclerosis formation and progression, thus it is a viable target for vascular protection in patients at risk of developing ASCVD. Leukotrienes, key pro-inflammatory lipid mediators derived from arachidonic acid, are associated with atheroma inflammation and progression. Genetic mutations in key components of the leukotriene synthesis pathway, such as 5-lipoxygenase (5-LO) and 5-lipoxygenase-activating protein (FLAP), are associated with an increased risk of cardiovascular disease, and pharmacological inhibition of 5-LO and FLAP has been reported to prevent atheroma formation in pre-clinical and early clinical studies. In this article, we provide an overview of these studies and highlight the therapeutic potential of targeting leukotriene synthesis to prevent atheroma inflammation and progression and improve outcomes in patients at risk of ASCVD.

Cardiovascular/Stroke Risk Stratification in Diabetic Foot Infection Patients Using Deep Learning-Based Artificial Intelligence: An Investigative Study

A diabetic foot infection (DFI) is among the most serious, incurable, and costly to treat conditions. The presence of a DFI renders machine learning (ML) systems extremely nonlinear, posing difficulties in CVD/stroke risk stratification. In addition, there is a limited number of well-explained ML paradigms due to comorbidity, sample size limits, and weak scientific and clinical validation methodologies. Deep neural networks (DNN) are potent machines for learning that generalize nonlinear situations. The objective of this article is to propose a novel investigation of deep learning (DL) solutions for predicting CVD/stroke risk in DFI patients. The Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) search strategy was used for the selection of 207 studies. We hypothesize that a DFI is responsible for increased morbidity and mortality due to the worsening of atherosclerotic disease and affecting coronary artery disease (CAD). Since surrogate biomarkers for CAD, such as carotid artery disease, can be used for monitoring CVD, we can thus use a DL-based model, namely, Long Short-Term Memory (LSTM) and Recurrent Neural Networks (RNN) for CVD/stroke risk prediction in DFI patients, which combines covariates such as office and laboratory-based biomarkers, carotid ultrasound image phenotype (CUSIP) lesions, along with the DFI severity. We confirmed the viability of CVD/stroke risk stratification in the DFI patients. Strong designs were found in the research of the DL architectures for CVD/stroke risk stratification. Finally, we analyzed the AI bias and proposed strategies for the early diagnosis of CVD/stroke in DFI patients. Since DFI patients have an aggressive atherosclerotic disease, leading to prominent CVD/stroke risk, we, therefore, conclude that the DL paradigm is very effective for predicting the risk of CVD/stroke in DFI patients.

The OSE complotype and its clinical potential

Cellular death, aging, and tissue damage trigger inflammation that leads to enzymatic and non-enzymatic lipid peroxidation of polyunsaturated fatty acids present on cellular membranes and lipoproteins. This results in the generation of highly reactive degradation products, such as malondialdehyde (MDA) and 4-hydroxynonenal (4-HNE), that covalently modify free amino groups of proteins and lipids in their vicinity. These newly generated neoepitopes represent a unique set of damage-associated molecular patterns (DAMPs) associated with oxidative stress termed oxidation-specific epitopes (OSEs). OSEs are enriched on oxidized lipoproteins, microvesicles, and dying cells, and can trigger sterile inflammation. Therefore, prompt recognition and removal of OSEs is required to maintain the homeostatic balance. This is partially achieved by various humoral components of the innate immune system, such as natural IgM antibodies, pentraxins and complement components that not only bind OSEs but in some cases modulate their pro-inflammatory potential. Natural IgM antibodies are potent complement activators, and 30% of them recognize OSEs such as oxidized phosphocholine (OxPC-), 4-HNE-, and MDA-epitopes. Furthermore, OxPC-epitopes can bind the complement-activating pentraxin C-reactive protein, while MDA-epitopes are bound by C1q, C3a, complement factor H (CFH), and complement factor H-related proteins 1, 3, 5 (FHR-1, FHR-3, FHR-5). In addition, CFH and FHR-3 are recruited to 2-(ω-carboxyethyl)pyrrole (CEP), and full-length CFH also possesses the ability to attenuate 4-HNE-induced oxidative stress. Consequently, alterations in the innate humoral defense against OSEs predispose to the development of diseases associated with oxidative stress, as shown for the prototypical OSE, MDA-epitopes. In this mini-review, we focus on the mechanisms of the accumulation of OSEs, the pathophysiological consequences, and the interactions between different OSEs and complement components. Additionally, we will discuss the clinical potential of genetic variants in OSE-recognizing complement proteins – the OSE complotype - in the risk estimation of diseases associated with oxidative stress.

B-1b Cells Have Unique Functional Traits Compared to B-1a Cells at Homeostasis and in Aged Hyperlipidemic Mice With Atherosclerosis

Immunoglobulin M (IgM) to oxidation specific epitopes (OSE) are inversely associated with atherosclerosis in mice and humans. The B-1b subtype of B-1 cells secrete IgM to OSE, and unlike B-1a cells, are capable of long-lasting IgM memory. What attributes make B-1b cells different than B-1a cells is unknown. Our objectives were to determine how B-1b cells produce more IgM compared to B-1a cells at homeostatic condition and to see the differences in the B-1a and B-1b cell distribution and IgM CDR-H3 sequences in mice with advanced atherosclerosis. Here, in-vivo studies demonstrated greater migration to spleen, splenic production of IgM and plasma IgM levels in ApoE^-/-Rag1^-/- mice intraperitoneally injected with equal numbers of B-1b compared to B-1a cells. Bulk RNA seq analysis and flow cytometry of B-1a and B-1b cells identified CCR6 as a chemokine receptor more highly expressed on B-1b cells compared to B-1a. Knockout of CCR6 resulted in reduced B-1b cell migration to the spleen. Moreover, B-1b cell numbers were significantly higher in spleen of aged atherosclerotic ApoE^-/- mice compared to young ApoE^-/- mice. Single cell sequencing results of IgHM in B-1a and B-1b cells from peritoneal cavity and spleen of atherosclerotic aged ApoE^-/- mice revealed significantly more N additions at the V-D and D-J junctions, greater diversity in V region usage and CDR-H3 sequences in B-1b compared to B-1a cells. In summary, B-1b cells demonstrated enhanced CCR6-mediated splenic migration, IgM production, and IgM repertoire diversification compared to B-1a cells. These findings suggest that potential strategies to selectively augment B-1b cell numbers and splenic trafficking could lead to increased and more diverse IgM targeting OSE to limit atherosclerosis.

The Breast Cancer Protooncogenes HER2, BRCA1 and BRCA2 and Their Regulation by the iNOS/NOS2 Axis

The expression of inducible nitric oxide synthase (iNOS; NOS2) and derived NO in various cancers was reported to exert pro- and anti-tumorigenic effects depending on the levels of expression and the tumor types. In humans, the breast cancer level of iNOS was reported to be overexpressed, to exhibit pro-tumorigenic activities, and to be of prognostic significance. Likewise, the expression of the oncogenes HER2, BRCA1, and BRCA2 has been associated with malignancy. The interrelationship between the expression of these protooncogenes and oncogenes and the expression of iNOS is not clear. We have hypothesized that there exist cross-talk signaling pathways between the breast cancer protooncogenes, the iNOS axis, and iNOS-mediated NO mutations of these protooncogenes into oncogenes. We review the molecular regulation of the expression of the protooncogenes in breast cancer and their interrelationships with iNOS expression and activities. In addition, we discuss the roles of iNOS, HER2, BRCA1/2, and NO metabolism in the pathophysiology of cancer stem cells. Bioinformatic analyses have been performed and have found suggested molecular alterations responsible for breast cancer aggressiveness. These include the association of BRCA1/2 mutations and HER2 amplifications with the dysregulation of the NOS pathway. We propose that future studies should be undertaken to investigate the regulatory mechanisms underlying the expression of iNOS and various breast cancer oncogenes, with the aim of identifying new therapeutic targets for the treatment of breast cancers that are refractory to current treatments.

Thirty-Five-Year History of Desialylated Lipoproteins Discovered by Vladimir Tertov

Atherosclerosis is one of the leading causes of death in developed and developing countries. The atherogenicity phenomenon cannot be separated from the role of modified low-density lipoproteins (LDL) in atherosclerosis development. Among the multiple modifications of LDL, desialylation deserves to be discussed separately, since its atherogenic effects and contribution to atherogenicity are often underestimated or, simply, forgotten. Vladimir Tertov is linked to the origin of the research related to desialylated lipoproteins, including the association of modified LDL with atherogenicity, autoimmune nature of atherosclerosis, and discovery of sialidase activity in blood plasma. The review will briefly discuss all the above-mentioned information, with a description of the current situation in the research.

The why and how of adaptive immune responses in ischemic cardiovascular disease

Atherosclerotic cardiovascular disease is a major cause of disability and death worldwide. Most therapeutic approaches target traditional risk factors but ignore the fundamental role of the immune system. This is a huge unmet need. Recent evidence indicates that reducing inflammation may limit cardiovascular events. However, the concomitant increase in the risk of lifethreatening infections is a major drawback. In this context, targeting adaptive immunity could constitute a highly effective and safer approach. In this Review, we address the why and how of the immuno-cardiovascular unit, in health and in atherosclerotic disease. We review and discuss fundamental mechanisms that ensure immune tolerance to cardiovascular tissue, and examine how their disruption promotes disease progression. We identify promising strategies to manipulate the adaptive immune system for patient benefit, including novel biologics and RNA-based vaccination strategies. Finally, we advocate for establishing a molecular classification of atherosclerosis as an important milestone in our quest to radically change the understanding and treatment of atherosclerotic disease.

Circulating Autoantibodies Recognizing Immunodominant Epitopes From Human Apolipoprotein B Associate With Cardiometabolic Risk Factors, but Not With Atherosclerotic Disease

Rationale

Atherosclerosis is a chronic inflammatory disease of large arteries that involves an autoimmune response with autoreactive T cells and auto-antibodies recognizing Apolipoprotein B (ApoB), the core protein of low-density lipoprotein (LDL). Here, we aimed to establish a clinical association between circulating human ApoB auto-antibodies with atherosclerosis and its clinical risk factors using a novel assay to detect auto-antibodies against a pool of highly immunogenic ApoB-peptides.

Methods and Results

To detect polyclonal IgM- and IgG-antibodies recognizing ApoB, we developed a chemiluminescent sandwich ELISA with 30 ApoB peptides selected by an in silico assay for a high binding affinity to MHC-II, which cover more than 80% of known MHC-II variants in a Caucasian population. This pre-selection of immunogenic self-peptides accounted for the high variability of human MHC-II, which is fundamental to allow T cell dependent generation of IgG antibodies. We quantified levels of ApoB-autoantibodies in a clinical cohort of 307 patients that underwent coronary angiography. Plasma anti-ApoB IgG and IgM concentrations showed no differences across healthy individuals (n = 67), patients with coronary artery disease (n = 179), and patients with an acute coronary syndrome (n = 61). However, plasma levels of anti-ApoB IgG, which are considered pro-inflammatory, were significantly increased in patients with obesity (p = 0.044) and arterial hypertension (p < 0.0001). In addition, patients diagnosed with the metabolic syndrome showed significantly elevated Anti-ApoB IgG (p = 0.002). Even when normalized for total plasma IgG, anti-ApoB IgG remained highly upregulated in hypertensive patients (p < 0.0001). We observed no association with triglycerides, total cholesterol, VLDL, or LDL plasma levels. However, total and normalized anti-ApoB IgG levels negatively correlated with HDL. In contrast, total and normalized anti-ApoB IgM, that have been suggested as anti-inflammatory, were significantly lower in diabetic patients (p = 0.012) and in patients with the metabolic syndrome (p = 0.005).

Conclusion

Using a novel ELISA method to detect auto-antibodies against ApoB in humans, we show that anti-ApoB IgG associate with cardiovascular risk factors but not with the clinical appearance of atherosclerosis, suggesting that humoral immune responses against ApoB are shaped by cardiovascular risk factors but not disease status itself. This novel tool will be helpful to develop immune-based risk stratification for clinical atherosclerosis in the future.

Preparation of LDL , Oxidation , Methods of Detection, and Applications in Atherosclerosis Research

The concept of lipid peroxidation has been known for a long time. It is now well established that LDL plays a major role in atherosclerosis. Oxidized low-density lipoprotein (Ox-LDL) has been studied for over 35 years. Numerous pro- and anti-atherogenic properties have been attributed to Ox-LDL. Component composition of Ox-LDL is complex due to the influence of various factors, including the source, method of preparation, storage and use. Hence, it is very difficult to clearly define and characterize Ox-LDL. It contains unoxidized and oxidized fatty acid derivatives both in the ester and free forms, their decomposition products, cholesterol and its oxidized products, proteins with oxidized amino acids and cross-links, polypeptides with varying extents of covalent modification with lipid oxidation products and many others. The measurement of lipid oxidation has been a great boon, not only to the understanding of the process but also in providing numerous serendipitous discoveries and methodologies. In this chapter, we outline the methodologies for the preparation and testing of various lipoproteins for oxidation studies.

Effectiveness of Some Vitamins in the Prevention of Cardiovascular Disease: A Narrative Review

By virtue of their regulatory role in various metabolic and biosynthetic pathways for energy status and cellular integrity, both hydro-soluble and lipo-soluble vitamins are considered to be involved in maintaining cardiovascular function in health and disease. Deficiency of some vitamins such as vitamin A, B₆, folic acid, C, D, and E has been shown to be associated with cardiovascular abnormalities whereas supplementation with these vitamins has been claimed to reduce cardiovascular risk for hypertension, atherosclerosis, myocardial ischemia, arrhythmias, and heart failure. However, the data from several experimental and clinical studies for the pathogenesis of cardiovascular disease due to vitamin deficiency as well as therapy due to different vitamins are conflicting. In this article, we have attempted to review the existing literature on the role of different vitamins in cardiovascular disease with respect to their deficiency and supplementation in addition to examining some issues regarding their involvement in heart disease. Although both epidemiological and observational studies have shown some merit in the use of different antioxidant vitamins for the treatment of cardiovascular disorders, the results are not conclusive. Furthermore, in view of the complexities in the mechanisms of different cardiovascular disorders, no apparent involvement of any particular vitamin was seen in any specific cardiovascular disease. On the other hand, we have reviewed the evidence that deficiency of vitamin B₆ promoted KCl-induced Ca²⁺ entry and reduced ATP-induced Ca²⁺-entry in cardiomyocytes in addition to decreasing sarcolemmal (SL) ATP binding. The active metabolite of vitamin B₆, pyridoxal 5′-phosphate, attenuated arrhythmias due to myocardial infarction (MI) as well as cardiac dysfunction and defects in the sarcoplasmic reticulum (SR) Ca²⁺-transport in the ischemic-reperfused hearts. These observations indicate that both deficiency of some vitamins as well as pretreatments with different vitamins showing antioxidant activity affect cardiac function, metabolism and cation transport, and support the view that antioxidant vitamins or their metabolites may be involved in the prevention rather than the therapy of cardiovascular disease.

Metabolites with Antioxidant Activity from Marine Macroalgae

Reactive oxygen species (ROS) attack biological molecules, such as lipids, proteins, enzymes, DNA, and RNA, causing cellular and tissue damage. Hence, the disturbance of cellular antioxidant homeostasis can lead to oxidative stress and the onset of a plethora of diseases. Macroalgae, growing in stressful conditions under intense exposure to UV radiation, have developed protective mechanisms and have been recognized as an important source of secondary metabolites and macromolecules with antioxidant activity. In parallel, the fact that many algae can be cultivated in coastal areas ensures the provision of sufficient quantities of fine chemicals and biopolymers for commercial utilization, rendering them a viable source of antioxidants. This review focuses on the progress made concerning the discovery of antioxidant compounds derived from marine macroalgae, covering the literature up to December 2020. The present report presents the antioxidant potential and biogenetic origin of 301 macroalgal metabolites, categorized according to their chemical classes, highlighting the mechanisms of antioxidative action when known.

Promoting athero-protective immunity by vaccination with low density lipoprotein-derived antigens

Immune responses activated by LDL particles that have been trapped and oxidized in the arterial wall play an important role in atherosclerosis. Some of these immune responses are protective by facilitating the removal of pro-inflammatory and toxic lipid species formed as result of LDL oxidation. However, should these protective immune responses be insufficient, other more potent pro-inflammatory immune responses instead contributing to disease progression will gradually become dominant. The importance of the balance between protective and pathogenic immunity is particularly apparent when it comes to the adaptive immune system where pro-inflammatory T helper 1 (Th1) type T cells aggravate atherosclerosis, while regulatory T cells (Tregs) have an opposing role. As oxidized LDL is a key autoantigen in atherosclerosis, it has become an interesting possibility that immune-modulatory therapy that favors the activity of apolipoprotein B peptide-specific Tregs could be developed into a novel treatment strategy for prevention/stabilization of atherosclerosis and ischemic cardiovascular events. Indeed, several such oxidized LDL tolerance vaccines have shown promising results in animal models of atherosclerosis. This review will discuss the experimental background for development of atherosclerosis vaccines based on LDL-derived antigens as well as the challenges involved in translating these findings into clinical application.

A Novel Immunoassay for Malondialdehyde-Conjugated Low-Density Lipoprotein Measures Dynamic Changes in the Blood of Patients Undergoing Coronary Artery Bypass Graft Surgery

Oxidized low-density lipoproteins play an important role in tissue pathology. In this study, we report a sensitive novel enzyme-linked immunosorbent assay for the detection of malondialdehyde-modified low-density lipoprotein (MDA-LDL), a key component of oxidized LDL. The assay is capable of measuring a variable presence of MDA-LDL within human plasma and serum. We demonstrate the robust nature of the assay on samples stored for over 20 months, as well as high inter-operator reproducibility (r = 0.74, p < 0.0001). The assay was capable of detecting dynamic changes in patient blood samples after coronary artery bypass graft surgery, indicating synthesis or release of MDA-LDL with the oxidative stress of surgery, followed by homeostatic clearance. This robust, sensitive and specific assay for circulating MDA-LDL will serve as a valuable translational tool for the improved detection of oxidative forms of LDL in response to a range of physiological or pathological stimuli, with potential clinical applicability.

Accelerated atherosclerosis caused by serum amyloid A response in lungs of ApoE-/- mice

Airway exposure to eg particulate matter is associated with cardiovascular disease including atherosclerosis. Acute phase genes, especially Serum Amyloid A3 (Saa3), are highly expressed in the lung following pulmonary exposure to particles. We aimed to investigate whether the human acute phase protein SAA (a homolog to mouse SAA3) accelerated atherosclerotic plaque progression in Apolipoprotein E knockout (ApoE^-/- ) mice. Mice were intratracheally (i.t.) instilled with vehicle (phosphate buffered saline) or 2 µg human SAA once a week for 10 weeks. Plaque progression was assessed in the aorta using noninvasive ultrasound imaging of the aorta arch as well as by en face analysis. Additionally, lipid peroxidation, SAA3, and cholesterol were measured in plasma, inflammation was determined in lung, and mRNA levels of the acute phase genes Saa1 and Saa3 were measured in the liver and lung, respectively. Repeated i.t. instillation with SAA caused a significant progression in the atherosclerotic plaques in the aorta (1.5-fold). Concomitantly, SAA caused a statistically significant increase in neutrophils in bronchoalveolar lavage fluid (625-fold), in pulmonary Saa3 (196-fold), in systemic SAA3 (1.8-fold) and malondialdehyde levels (1.14-fold), indicating acute phase response (APR), inflammation and oxidative stress. Finally, pulmonary exposure to SAA significantly decreased the plasma levels of very low-density lipoproteins - low-density lipoproteins and total cholesterol, possibly due to lipids being sequestered in macrophages or foam cells in the arterial wall. Combined these results indicate the importance of the pulmonary APR and SAA3 for plaque progression.

Water-soluble palm fruit extract: composition, biological properties, and molecular mechanisms for health and non-health applications

The oil palm (Elaeis guineensis) fruit is a source of vegetable oil and various phytonutrients. Phytochemical compounds present in palm oil include tocotrienols, carotenoids, phytosterols, squalene, coenzyme Q₁₀, and phospholipids. Being a fruit, the oil palm is also a rich source of water-soluble phytonutrients, including phenolic compounds. Extraction of phytonutrients from the oil palm vegetation liquor of palm oil milling results in a phenolic acid-rich fraction termed Water-Soluble Palm Fruit Extract (WSPFE). Pre-clinical in vitro, ex vivo, and in vivo studies carried out using various biological models have shown that WSPFE has beneficial bioactive properties, while clinical studies in healthy volunteers showed that it is safe for human consumption and confers antioxidant and anti-inflammatory effects. The composition, biological properties, and relevant molecular mechanisms of WSPFE discovered thus far are discussed in the present review, with a view to offer future research perspectives on WSPFE for health and non-health applications.

Redox regulation of hemodynamics response to diadenosine tetraphosphate an agonist of P2 receptors and renal function in diet-induced hypercholesterolemic rats

Hypercholesterolemia and oxidative stress may lead to disturbances in the renal microvasculature in response to vasoactive agents, including P2 receptors (P2R) agonists. We investigated the renal microvascular response to diadenosine tetraphosphate (Ap₄A), an agonist of P2R, in diet‐induced hypercholesteremic rats over 28 days, supplemented in the last 10 days with tempol (2 mM) or DL‐buthionine‐(S,R)‐sulfoximine (BSO, 20 mM) in the drinking water. Using laser Doppler flowmetry, renal blood perfusion in the cortex and medulla (CBP, MBP) was measured during the infusion of Ap₄A. This induced a biphasic response in the CBP: a phase of rapid decrease was followed by one of rapid increase extended for 30 min in both the normocholesterolemic and hypercholesterolemic rats. The phase of decreased CBP was not affected by tempol or BSO in either group. Early and extended increases in CBP were prevented by tempol in the hypercholesterolemia rats, while, in the normocholesterolemic rats, only the extended increase in CBP was affected by tempol; BSO prevented extended increase in CBP in normocholesterolemic rats. MBP response is not affected by hypercholesterolemia. The hypercholesterolemic rats were characterized by increased urinary albumin and 8‐isoPGF_2α excretion. Moreover, BSO increased the urinary excretion of nephrin in the hypercholesterolemic rats but, similar to tempol, did not affect the excretion of albumin in their urine. The results suggest the important role of redox balance in the extracellular nucleotide regulation of the renal vasculature and glomerular injury in hypercholesterolemia.

Proatherogenic Sialidases and Desialylated Lipoproteins: 35 Years of Research and Current State from Bench to Bedside

This review summarizes the main achievements in basic and clinical research of atherosclerosis. Focusing on desialylation as the first and the most important reaction of proatherogenic pathological cascade, we speak of how desialylation increases the atherogenic properties of low density lipoproteins and decreases the anti-atherogenic properties of high density lipoproteins. The separate sections of this paper are devoted to immunogenicity of lipoproteins, the enzymes contributing to their desialylation and animal models of atherosclerosis. In addition, we evaluate the available experimental and diagnostic protocols that can be used to develop new therapeutic approaches for atherosclerosis.

Screening differentially expressed proteins of coronary heart disease with congenital cold syndrome based on tandem mass tag (TMT) technology

In our previous studies, we discovered the congenital cold syndrome (CCS), which is characterized by 'qi deficiency and qi stagnation, mixed cold and heat.' And there is a type of syndrome with special incidence characteristic. However, the diagnosis of CCS still lacks an objective basis. In this study, we performed Tandem Mass Tag (TMT) based on quantitative proteomics technology to screen the significantly differentially expressed proteins (DEPs) in serum of patients with coronary heart disease (CHD) patients with CCS, patients with heart and kidney yang deficiency, and healthy people. A total of 22 DEPs (nine upregulated and 13 downregulated) were identified between patients with CCS and healthy subjects. Next, we performed GO and KEGG pathway enrichment analysis, we found the primary functions of DEPs of CCS were binding, catalytic activity, and molecular function regulator. These DEPs were mainly involved in important biological processes, such as cellular process, response to stimulus, localization, metabolic process, and biological regulation. The KEGG analysis revealed that the DEPs showed significant changes in fructose and mannose metabolism, Pentose phosphate pathway, and Arrhythmogenic right ventricular cardiomyopathy. After parallel reaction monitoring (PRM) verification, four upregulated target proteins (ALDOA, PCYOX1, Crisp3 and IGLV4-69) and three downregulated proteins (ALDOC, ADAMTSL-2 and C3) were accurately identified. These proteins were mainly related to immune response and glucose metabolism. These DEPs could be the marker proteins of coronary heart disease with CCS. This findings help to reveal the pathogenesis of CHD with CCS and provide potential therapeutic targets.

Overview of OxLDL and Its Impact on Cardiovascular Health: Focus on Atherosclerosis

Cardiovascular pathologies maintain the leading position in mortality worldwide. Atherosclerosis is a chronic disease that can result in a variety of serious complications, such as myocardial infarction, stroke, and cardiovascular disease. Inflammation and lipid metabolism alterations play a crucial role in atherogenesis, but the details of relationships and causality of these fundamental processes remain not clear. The oxidation of LDL was considered the main atherogenic modification of LDL within the vascular wall for decades. However, recent investigations provided a growing body of evidence in support of the multiple LDL modification theory. It suggests that LDL particles undergo numerous modifications that change their size, density, and chemical properties within the blood flow and vascular wall. Oxidation is the last stage in this cascade resulting in the atherogenic properties. Moreover, recent investigations have discovered that oxLDL may have both anti-inflammatory and pro-inflammatory properties. Oxidized LDL can trigger inflammation through the activation of macrophages and other cells. After all, oxidized LDL is still a promising object for further investigations that have the potential to clarify the unknown parts of the atherogenic process. In this review, we discuss the role of oxLDL in atherosclerosis development on different levels.

Antioxidative attributes of rice bran extracts in ameliorative effects of atherosclerosis-associated risk factors

Oxidative stress, chronic inflammation, dyslipidemia, hyperglycemia, and shear stress (physical effect) are risk factors associated with the pathogenesis of atherosclerosis. Rice bran, a by-product of rice milling process, is known to house polyphenols and vitamins which exhibit potent antioxidant and anti-inflammatory properties. Through recent emerging knowledge of rice bran in health and wellness, the present study was aimed to assess the ameliorative effects of rice bran extracts (RBE) derived from Japanese colored rice varieties in modulating risk factors of atherosclerosis via in vitro and in vivo study models. Pre-treatment of lipopolysaccharide (LPS)-stimulated murine J774A.1 macrophage-like cells with RBE alleviated nitric oxide (NO) overproduction and downregulated gene expressions of pro-inflammatory modulators: tumor necrosis factor-α (TNF-α), interleukin (IL)-α (IL-1α), IL-1β, IL-6, and inducible nitric oxide synthase (iNOS). In addition, RBE also significantly attenuated LPS-stimulated protein expressions of iNOS, TNF-α, IL-1α, and IL-6 in J774A.1 macrophage-like cells as compared to non-treated LPS control group. In in vivo, 12 weeks of RBE dietary supplementations significantly reduced (p < 0.05) total cholesterol, triglycerides, and pro-atherogenic oxidized LDL/β2-glycoprotein I (oxLDL/β2GPI) complexes at plasma levels, in high fat diet (HFD) induced low density lipoprotein receptor knockout (Ldlr^−/-) mice. En face pathological assessments of murine aortas also revealed significant reductions by 38% (p < 0.05) in plaque sizes of RBE-supplemented HFD mice groups as compared to non RBE-supplemented HFD control mice group. Moreover, gene expressions of aortic (iNOS, TNF-α, IL-1β) and hepatic (TNF-α, IL-1α, IL-1β) pro-inflammatory modulators were also downregulated in RBE-supplemented mice groups. Present study has revealed the potent health attributes and application of RBE as a dietary supplement to attenuate risks of inadvertent oxidative damage and chronic inflammation underlying the pathogenesis of atherosclerosis. Intrinsically, present preliminary findings may provide global health prospects for future dietary implementation of RBE in management of atherosclerosis.

Effects of Myricitrin and Relevant Molecular Mechanisms

In humans, oxidative stress is thought to be involved in the development of Parkinson's disease, Alzheimer's disease, atherosclerosis, heart failure, myocardial infarction and depression. Myricitrin, a botanical flavone, is abundantly distributed in the root bark of Myrica cerifera, Myrica esculenta, Ampelopsis grossedentata, Nymphaea lotus, Chrysobalanus icaco, and other plants. Considering the abundance of its natural sources, myricitrin is relatively easy to extract and purify. Myricitrin reportedly possesses effective anti-oxidative, anti-inflammatory, and anti-nociceptive activities, and can protect a variety of cells from in vitro and in vivo injuries. Therefore, our current review summarizes the research progress of myricitrin in cardiovascular diseases, nerve injury and anti-inflammatory, and provides new ideas for the development of myricitrin.

Circulating Levels of CILP2 Are Elevated in Coronary Heart Disease and Associated with Atherosclerosis

Methods and Results

Circulating CILP2 levels (measured by ELISA) were compared to various insulin resistance- and atherosclerosis-related parameters in normal subjects and newly diagnosed CHD patients. THP-1 cells were cultured and treated with indicated stimulators. Western blots and RT-PCR were performed to examine protein and mRNA expressions. The results showed that there were significantly higher circulating CILP2 levels in CHD patients relative to healthy controls. Circulating CILP2 correlated positively with waist-hip ratio (WHR), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), HbA1c, homeostasis model assessment of insulin resistance (HOMA-IR), and Gensini scores. In an in vitro study, we found that CILP2 increased oxidatively modified LDL-stimulated lipid accumulation in THP-1 macrophages via the upregulation of CD36 expression. Inhibition of PPARγ signaling eliminated the CILP2 regulation of CD36 expression in THP-1 macrophages. CILP2 positively regulated CD36 transcription through PPARγ-mediated action on two peroxisome-proliferator-responsive elements (PPREs) binding sites of CD36 promoter, PPRE-G, and PPRE-J.

Conclusions

Our findings have uncovered a novel role for CILP2 in lipid uptake and foam cell formation. This role is mediated by CD36 through the activation of PPARγ pathway.

Mechanistic Insights into the Oxidized Low-Density Lipoprotein-Induced Atherosclerosis

Dyslipidaemia has a prominent role in the onset of notorious atherosclerosis, a disease of medium to large arteries. Atherosclerosis is the prime root of cardiovascular events contributing to the most considerable number of morbidity and mortality worldwide. Factors like cellular senescence, genetics, clonal haematopoiesis, sedentary lifestyle-induced obesity, or diabetes mellitus upsurge the tendency of atherosclerosis and are foremost pioneers to definitive transience. Accumulation of oxidized low-density lipoproteins (Ox-LDLs) in the tunica intima triggers the onset of this disease. In the later period of progression, the build-up plaques rupture ensuing thrombosis (completely blocking the blood flow), causing myocardial infarction, stroke, and heart attack, all of which are common atherosclerotic cardiovascular events today. The underlying mechanism is very well elucidated in literature but the therapeutic measures remains to be unleashed. Researchers tussle to demonstrate a clear understanding of treating mechanisms. A century of research suggests that lowering LDL, statin-mediated treatment, HDL, and lipid-profile management should be of prime interest to retard atherosclerosis-induced deaths. We shall brief the Ox-LDL-induced atherogenic mechanism and the treating measures in line to impede the development and progression of atherosclerosis.

Identification and visualization of oxidized lipids in atherosclerotic plaques by microscopic imaging mass spectrometry-based metabolomics

BACKGROUND AND AIMS

Dysregulated lipid metabolism has emerged as one of the major risk factors of atherosclerosis. Presently, there is a consensus that oxidized LDL (oxLDL) promotes development of atherosclerosis and downstream chronic inflammatory responses. Due to the dynamic metabolic disposition of lipoprotein, conventional approach to purify bioactive lipids for subsequent comprehensive analysis has proven to be inadequate for elucidation of the oxidized lipids species accountable for pathophysiology of atherosclerotic lesions. Herein, we aimed to utilize a novel mass microscopic imaging technology, coupled with mass spectrometry (MS) to characterize oxidized lipids in atherosclerotic lesions.

METHODS

We attempted to use MALDI-TOF-MS and iMScope to identify selected oxidized lipid targets and visualize their respective localizations in study models of atherosclerosis.

RESULTS

Based on the MS analysis, detection of 7-K under positive ionization through product ion peak at m/z 383 [M + H-H₂O] indicated the distinctive presence of targeted lipid within Cu²⁺-oxLDL and Cu²⁺-oxLDL loaded macrophage-like J774A.1 cells, along with other cholesterol oxidation products. Moreover, the application of two-dimensional iMScope has successfully visualized the localization of lipids in aortic atherosclerotic plaques of the Watanabe heritable hyperlipidemic (WHHL) rabbit. Distinctive lipid distribution profiles were observed in atherosclerotic lesions of different sizes, especially the localizations of lysoPCs in atherosclerotic plaques.

CONCLUSIONS

Taken together, we believe that both MALDI-TOF-MS and iMScope metabolomics technology may offer a novel proposition for future pathophysiological studies of lipid metabolism in atherosclerosis.

Urtica Pilulifera in Treating Pre-diabetic Rat Model to Control the Blood Glucose, Lipids and Oxidative Stress

Introduction:

Pre-diabetic precedes the development of full diabetes. Studying and identification changes in pre-diabetic conditions can give the possibility to decline the development of diabetes and treat conditions associated with diabetes such as cardiovascular diseases.

Aim:

The main objectives of the present study were to investigate the potential of using Urtica pilulifera in treating the pre-diabetic rat model and to investigate its anti-oxidant impact.

Methods:

The pre-diabetic model was induced in rats through daily giving high sucrose diet (35%) for 30 days. The extraction of U. pilulifera leaves was made as described by previous studies. Thirty male Wistar rats were randomly divided into three groups, control group (n=10), pre-diabetic group (n=10), and treated group with the extract of U. pilulifera (n=10). Control group rats received standard diet; pre-diabetic group rats received standard diet and high sucrose (35%) in drinking water, treated group rats received the same conditions as a pre-diabetic group, with intra-peritoneal injection of U. pilulifera injection on daily basis. After one month experiment, blood samples were taken from all rats and tested for glucose, triglycerides, cholesterol, GSH, TAC, and MDA.

Results:

Both glucose and triglycerides levels were significantly increased in pre-diabetic groups, and significantly reduced in the treated group by the extract of U.pilulifera. The cholesterol level was not significantly changed in all groups. The levels of GSH were significantly reduced in the pre-diabetic group compared with the control group. Treatment with the extract of U. pilulifera increased the levels of GSH significantly compared with the pre-diabetic group. The levels of TAC were not significantly changed between the control group and the pre-diabetic group, but significantly increased in the treated group compared with the pre-diabetic group. The levels of MDA significantly increased in the pre-diabetic group compared with the control group, and significantly reduced in the treated group compared with the control group.

Conclusion:

High sucrose pre-diabetic model is a good model to study diabetes at early stages, and the treatment using U. pilulifera has several benefits in reducing glucose and lipid profile lipids as well as combating oxidative stress.

Hypocholesterolemic Effect of Pravastatin is Associated with Increased Content of Antioxidant Vitamin-E in Cholesterol Fractions

Metabolic studies support the findings that antioxidants inhibit atherosclerosis. Treatment with vitamin E reduced both the susceptibility of low density lipoprotein cholesterol (LDL-C) to in vivo lipid peroxidation and atherosclerosis and smooth muscle proliferation. Thus the aim of present study was to examine metabolic consequences of reduced plasma LDL-C during hypolipidemic therapy and the distribution of antioxidant vitamin E. A group of 10 patients (4 men, 6 women, age 35 - 65y) with familial hypercholesterolaemia was treated using pravastatin (Lipostat® Bristol Myers Squibb, 40mg daily at 6.00 PM). Blood samples were examined before treatment, after 4 and 8 weeks of therapy. After ultracentrifugation, samples were analyzed for lipoprotein fractions and the content of vitamin E and cholesterol. Pravastatin reduced both total cholesterol (9.85±0.74 vs. 6.81±0.51 mmol/l; p<0.01), LDL-C (6.42±0.45 vs. 4.51±0.45 mmol/l; p<0.01), light LDL1-C (4.56±0.50 vs. 3.11±0.34 mmol/l; p<0.05) and dense LDL2-C (1.86±0.27 vs. 1.42±0.17 mmol/l; ns). Serum vitamin E was reduced during hypolipidemic therapy in the fraction of total, LDL1, LDL2 and VLDL-cholesterol. However, the ratio of serum vitamin E/total serum cholesterol (4.57±0.32 vs. 5.12±0.37 mmol/l/mmol/l; p<0.05) and ratio of LDL2-C vitamin E/LDL2-C (3.92±0.07 vs. 4.64±0.37 mmol/l/mmol/l; p=0.08) increased in comparison to pre-treatment values. We conclude that pravastatin therapy may possess anti-atherogenic properties which involve not only its hypocholesterolemic effect, but also its favorable effects on the distribution of LDL subclasses and the content of antioxidant vitamin E in atherogenic lipoproteins.

Oxidized Low-Density Lipoprotein Induces Macrophage Production of Prothrombotic Microparticles

Background Activated vascular cells produce submicron prothrombotic and proinflammatory microparticle vesicles. Atherosclerotic plaques contain high levels of microparticles. Plasma microparticle levels increase during acute coronary syndromes and the thrombotic consequences of plaque rupture likely involve macrophage-derived microparticles (MΦMPs). The activation pathways that promote MΦMP production remain poorly defined. This study tested the hypothesis that signals implicated in atherogenesis also stimulate MΦMP production. Methods and Results We stimulated human primary MΦs with proinflammatory cytokines and atherogenic lipids, and measured MΦMP production by flow cytometry. Oxidized low-density lipoprotein (oxLDL; 25 µg/mL) induced MΦMP production in a concentration-dependent manner (293% increase; P<0.001), and these oxLDL MΦMP stimulatory effects were mediated by CD36. OxLDL stimulation increased MΦMP tissue factor content by 78% (P<0.05), and oxLDL-induced MΦMP production correlated with activation of caspase 3/7 signaling pathways. Salvionolic acid B, a CD36 inhibitor and a CD36 inhibitor antibody reduced oxLDL-induced MΦMP by 67% and 60%, respectively. Caspase 3/7 inhibition reduced MΦMP release by 52% (P<0.01) and caspase 3/7 activation increased MΦMP production by 208% (P<0.01). Mevastatin pretreatment (10 µM) decreased oxLDL-induced caspase 3/7 activation and attenuated oxLDL-stimulated MΦMP production and tissue factor content by 60% (P<0.01) and 43% (P<0.05), respectively. Conclusions OxLDL induces the production of prothrombotic microparticles in macrophages. This process depends on caspases 3 and 7 and CD36 and is inhibited by mevastatin pretreatment. These findings link atherogenic signaling pathways, inflammation, and plaque thrombogenicity and identify a novel potential mechanism for antithrombotic effects of statins independent of LDL lowering.

Mitochondrial Contact Sites in Inflammation-Induced Cardiovascular Disease

The mitochondrion, the ATP-producing center, is both physically and functionally associated with almost all other organelles in the cell. Mitochondrial-associated membranes (MAMs) are involved in a variety of biological processes, such as lipid exchange, protein transport, mitochondrial fission, mitophagy, and inflammation. Several inflammation-related diseases in the cardiovascular system involve several intracellular events including mitochondrial dysfunction as well as disruption of MAMs. Therefore, an in-depth exploration of the function of MAMs will be of great significance for us to understand the initiation, progression, and clinical complications of cardiovascular disease (CVD). In this review, we summarize the recent advances in our knowledge of MAM regulation and function in CVD-related cells. We discuss the potential roles of MAMs in activating inflammation to influence the development of CVD.

Periodontal therapy and cardiovascular risk

Cardiovascular diseases are the worldwide leading cause of mortality. Cardiovascular diseases are noncommunicable conditions with a complex pathogenesis, and their clinical manifestations include major cardiovascular events such as myocardial infarction and stroke. Epidemiologic evidence suggests a consistent association between periodontitis and increased risk of cardiovascular diseases. Some evidence supports a beneficial effect of the treatment of periodontitis on both surrogate and hard cardiovascular outcomes. This narrative review has been conducted as an update of the most recent evidence on the effects of periodontitis treatment on cardiovascular outcomes since the last commissioned review of the European Federation of Periodontology-American Academy of Periodontology World Workshop in 2012. Newer evidence originating from published randomized controlled trials confirms a positive effect of periodontal treatment on surrogate measures of cardiovascular diseases, whereas there have been no randomized controlled trials investigating the effect of periodontal treatment on the incidence of cardiovascular disease events such as myocardial infarction and stroke. In conclusion, there is sufficient evidence from observational and experimental studies on surrogate cardiovascular measures to justify the design and conduct of appropriately powered randomized controlled trials investigating the effect of effective periodontal interventions on cardiovascular disease outcomes (ie, myocardial infarction and stroke) with adequate control of traditional cardiovascular risk factors.

Rapid and specific detection of oxidized LDL/β2GPI complexes via facile lateral flow immunoassay

β2-Glycoprotein I (β2GPI) forms indissociable complex with oxidized LDL (oxLDL) into proatherogenic oxLDL/β2GPI complex through a specific ligand known as 7-ketocholesteryl-9-carboxynonanoate (oxLig-1). Recent discoveries have demonstrated the atherogenicity of these complexes in patients of both systemic and non-systemic autoimmune diseases. Hence, serological level of oxLDL/β2GPI complexes may represent one crucial clinical parameter for disease prognosis of atherosclerosis-related diseases. Herein, we established a simple, specific and rapid gold nanoparticle (GNP) based lateral flow immunoassay (LFIA) to quantify oxLDL/β2GPI complexes from test samples. Specificities of hybridoma cell-derived monoclonal antibodies against antigen, optimal conditions for conjugation of antibody with GNP, and sensitivity of oxLDL/β2GPI LFIA in comparison to an ELISA-based detection method were assessed accordingly. The established oxLDL/β2GPI LFIA was capable of detecting oxLDL/β2GPI specifically without interference from autoantibodies and solitary components of oxLDL/β2GPI present in test samples. A significant correlation (R² > 0.8) was also obtained with the oxLDL/β2GPI LFIA when compared to the ELISA-based detection. On the whole, the oxLDL/β2GPI LFIA remains advantageous over the oxLDL/β2GPI ELISA. The unnecessary washing step, short developmental and analytical time support facile and rapid detection of oxLDL/β2GPI as opposed to the laborious ELISA system.

Vaccination Strategies and Immune Modulation of Atherosclerosis

Adaptive as well as innate immune responses contribute to the development of atherosclerosis. Studies performed in experimental animals have revealed that some of these immune responses are protective while others contribute to the progression of disease. These observations suggest that it may be possible to develop novel therapies for cardiovascular disease by selectively modulating such atheroprotective and proatherogenic immunity. Recent advances in cancer treatment using immune check inhibitors and CAR (chimeric antigen receptor) T-cell therapy serve as excellent examples of the possibilities of targeting the immune system to combat disease. LDL (low-density lipoprotein) that has accumulated in the artery wall is a key autoantigen in atherosclerosis, and activation of antigen-specific T helper 1–type T cells is thought to fuel plaque inflammation. Studies aiming to prove this concept by immunizing experimental animals with oxidized LDL particles unexpectedly resulted in activation of atheroprotective immunity involving regulatory T cells. This prompted several research groups to try to develop vaccines against atherosclerosis. In this review, we will discuss the experimental and clinical data supporting the possibility of developing immune-based therapies for lowering cardiovascular risk. We will also summarize ongoing clinical studies and discuss the challenges associated with developing an effective and safe atherosclerosis vaccine.

An Overview of Atherosclerosis: A Look to the Future*

This overview briefly summarizes the cellular pathobiology of experimental atherosclerosis and is then followed by a consideration of how 3 major risk factors interact with the hypothesized pathogenetic process. First, since hemodynamics and blood flow influence the localization of atherosclerotic plaques, possible mechanisms and directions of research are considered. Secondly, the recent hypothesis relating the oxidation of LDL to several of the early processes of atherogenesis is briefly discussed in view of the fact that hyperlipidemia is a major risk factor. The possibility that subsets of LDL and lipoproteins other than LDL might be involved is also discussed. Family history is the last of the 3 contributors to atherosclerosis reviewed and some prototypes of gene abnormalities are considered. Finally, the needs and prospects of future research are summarized.

Macrophages, Endothelial Cells, and Lipoprotein Oxidation in the Pathogenesis of Atherosclerosis*

One of the earliest phenomena in the atherogenic process in cholesterol-fed rabbits appears to be the trapping of low density lipoproteins (LDL) at lesion-prone sites in the aorta. The resulting increase in residence time may facilitate oxidation of the lipoproteins, which, in turn, may be a chemotactic signal for monocytes to enter the intima. Oxidized lipoproteins may also be the major source of the cholesterol that the cells accumulate during their transformation into macrophage-derived foam cells (MFC). Adherent monocytes appear to cluster over small groups of subendothelial foam cells, perhaps in response to the enhanced expression of specific adhesion molecules on the surface of endothelial cells and/or monocytes following activation by oxidized lipoproteins. Lipoproteins oxidized by MFC may also injure endothelial cells causing them to retract or rupture. The resulting exposure of the MFC facilitates the formation of mural thrombi. MFC contain oxidation-specific lipid-protein adducts and specifically express the mRNA for 15-lipoxygenase, an enzyme potentially involved in lipoprotein oxidation. MFC isolated from atherosclerotic lesions and containing up to 600 μg cholesterol/mg protein are still capable of binding and degrading modified lipoproteins and affecting the oxidation of LDL.

The Herbicide Glyphosate and Its Apparently Controversial Effect on Human Health: An Updated Clinical Perspective

BACKGROUND

Glyphosate (G) is the most common weed-killer in the world. Every year tons and tons of G are applied on crop fields. G was first introduced in the mid 1970s and since then its usage has gradually increased to reach a peak since 2005. Now G usage is approximately 100 -fold what it was in 1970. Its impact on human health was considered benign at the beginning. But over the years, evidence of a pervasive negative effect of this pesticide on humans has been mounting. Nonetheless, G usage is allowed by government health control agencies (both in the United States and Europe), that rely upon the evidence produced by the G producer. However, the IARC (International Agency for Research on Cancer) in 2015 has stated that G is probable carcinogenic (class 2A), the second highest class in terms of risk.

OBJECTIVE

In this review, we explore the effect of G on human health, focusing in particular on more recent knowledge.

RESULTS

We have attempted to untangle the controversy about the dangers of the product for human beings in view of a very recent development, when the so -called Monsanto Papers, consisting of Emails and memos from Monsanto came to light, revealing a coordinated strategy to manipulate the debate about the safety of glyphosate to the company's advantage.

CONCLUSION

The story of G is a recurrent one (see the tobacco story), that seriously jeopardizes the credibility of the scientific study in the modern era.

Modified sites and functional consequences of 4-oxo-2-nonenal adducts in HDL that are elevated in familial hypercholesterolemia

The lipid aldehyde 4-oxo-2-nonenal (ONE) is a highly reactive protein crosslinker derived from peroxidation of n-6 polyunsaturated fatty acids and generated together with 4-hydroxynonenal (HNE). Lipid peroxidation product-mediated crosslinking of proteins in high-density lipoprotein (HDL) causes HDL dysfunction and contributes to atherogenesis. Although HNE is relatively well-studied, the role of ONE in atherosclerosis and in modifying HDL is unknown. Here, we found that individuals with familial hypercholesterolemia (FH) had significantly higher ONE-ketoamide (lysine) adducts in HDL (54.6 ± 33.8 pmol/mg) than healthy controls (15.3 ± 5.6 pmol/mg). ONE crosslinked apolipoprotein A-I (apoA-I) on HDL at a concentration of > 3 mol ONE per 10 mol apoA-I (0.3 eq), which was 100-fold lower than HNE, but comparable to the potent protein crosslinker isolevuglandin. ONE-modified HDL partially inhibited HDL's ability to protect against lipopolysaccharide (LPS)-induced tumor necrosis factor α (TNFα) and interleukin-1β (IL-1β) gene expression in murine macrophages. At 3 eq, ONE dramatically decreased apoA-I exchange from HDL, from ∼46.5 to ∼18.4% (p < 0.001). Surprisingly, ONE modification of HDL or apoA-I did not alter macrophage cholesterol efflux capacity. LC-MS/MS analysis revealed that Lys-12, Lys-23, Lys-96, and Lys-226 in apoA-I are modified by ONE ketoamide adducts. Compared with other dicarbonyl scavengers, pentylpyridoxamine (PPM) most efficaciously blocked ONE-induced protein crosslinking in HDL and also prevented HDL dysfunction in an in vitro model of inflammation. Our findings show that ONE-HDL adducts cause HDL dysfunction and are elevated in individuals with FH who have severe hypercholesterolemia.

Epitope mapping and characterization of 4-hydroxy-2-nonenal modified-human serum albumin using two different polyclonal antibodies

Lipids are susceptible to damage by reactive oxygen species, and from lipid oxidation reactions many short chain lipid peroxidation products can be formed. 4-Hydroxy-2-nonenal (HNE) is one of the most abundant and cytotoxic lipid oxidation products and is known to form covalent adducts with nucleophilic amino acids of proteins. HNE-modified proteins have value as biomarkers and can be detected by antibody-based techniques, but most commercially available antibodies were raised against HNE-keyhole limpet hemocyanin. We used HNE-treated human serum albumin (HSA) to raise sheep antiserum and report for the first time the use of covalently modified peptide arrays to assess epitope binding of antibodies (Abs). Peptide arrays covering the sequence of HSA and treated post peptide synthesis with HNE were used to compare the different binding patterns of a commercial polyclonal antibody (pAb) raised against HNE-treated KLH and an in-house anti-HNE enriched pAb. The results were correlated with analysis of HNE-modified HSA by high-resolution tandem mass spectrometry. Both anti-HNE pAbs were found to bind strongly to eight common peptides on the HNE-treated HSA membranes, suggesting that HNE adducts per se induced an immune response in both cases even though different immunogens were used. Both antibodies bound with the highest affinity to the peptide ³⁶⁵DPHECYAKVFDEFKPLV³⁸¹, which contains K378 and was also shown to be modified by the mass spectrometry analysis. Overall, the commercial anti-HNE pAb showed better specificity, recognizing nine out of the eleven adducts found by MS/MS, while the in-house enriched pAb only recognizes six. Nevertheless, the in-house pAb recognized specific peptides that were not recognized by the commercial pAb, which suggests the presence of clones uniquely specific to HNE adducts on HSA.