Background: Atherosclerosis is a chronic disease characterized by the increased infiltration and retention of LDL particles in arterial walls. There are several mechanisms underlying atherogenesis, with the pro-atherogenic modifications of LDL playing a significant role. One such modification of native LDL is desialylation, which is characterized by the removal of terminal sialic acid from ApoB-100 glycans that induces critical changes in the overall functionality of the LDL particle. Aims: The aim of this study was to model the desialylation of native LDL in mice, resembling a phenomenon previously observed in atherosclerotic patients. Objective: LDL desialylation was induced in C57BL/6J mice via the injection of exogenous neuraminidase. The degree of LDL desialylation and its duration were assessed. The impact of LDL desialylation on blood lipid levels was evaluated. Furthermore, the morphological alterations in the aorta during LDL desialylation in the bloodstream were examined. Method: The control group of C57BL/6J mice received saline injections, while the experimental group underwent a single injection of IgG-conjugated Vibrio cholerae neuraminidase. The LDL sialic acid levels were assessed 1-7 days post-injection using the Warren method and normalized to total protein content measured via the Lowry method. A similar protocol was followed for the subchronic administration of the IgG-neuraminidase conjugate over a 6-week period. The blood lipid profiles were analyzed using commercial kits. The atherosclerotic plaque burden in the mouse aorta was quantified using Oil Red O and hematoxylin-eosin staining. Result: A single administration of 20 mU IgG-neuraminidase conjugate resulted in decreased LDL sialic acid levels for 5 days, gradually recovering by days 6-7. Subchronic administration maintained reduced LDL sialic acid levels for up to 2 months. Notably, sustained LDL desialylation was associated with elevated LDL cholesterol levels. Conclusion: A sustained desialylation of LDL in C57BL/6J mice was achieved through subchronic administration of IgG-conjugated neuraminidase. This study provides an approach for sustained LDL desialylation in mice. Further studies using apolipoprotein E knockout mice and LDL desialylation will reveal the role of this process in the occurrence and development of atherosclerosis.

BACKGROUND:Atherosclerosis is a complex cardiovascular disease often associated with mitochondrial dysfunction, which can lead to various cellular and metabolic abnormalities. Within the mitochondrial genome, specific mutations have been implicated in contributing to mitochondrial dysfunction. Atherosclerosis-associated m.15059G>A mutation has been of particular interest due to its potential role in altering mitochondrial function and cellular health. OBJECTIVE:This study aims to investigate the role of the atherosclerosis-associated m.15059G>A mutation in the development of mitochondrial dysfunction in monocytelike cells. METHODS:Monocyte-like cytoplasmic hybrid cell line TC-HSMAM1, which contains the m.15059G>A mutation in mtDNA, was used. The MitoCas9 vector was utilized to eliminate mtDNA copies carrying the m.15059G>A mutation from TC-HSMAM1 cybrids. Mitochondrial membrane potential, generation of reactive oxygen species, and lipid peroxidation levels were assessed using flow cytometry. Cellular reduced glutathione levels were assessed using the confocal microscopy. The oxygen consumption rate was measured using polarographic oxygen respirometry. RESULTS:The elimination of the m.15059G>A mutation resulted in a significant increase in mitochondrial membrane potential and improved mitochondrial efficiency while also causing a decrease in the generation of reactive oxygen species, lipid peroxidation, as well as cellular bioenergetic parameters, such as proton leak and non-mitochondrial oxygen consumption. At the same time, no changes were found in the intracellular antioxidant system after the mitochondrial genome editing. CONCLUSION:The presence of the m.15059G>A mutation contributes to mitochondrial dysfunction by reducing mitochondrial membrane potential, increasing the generation of reactive oxygen species and lipid peroxidation, and altering mitochondrial bioenergetics. Elimination of the mtDNA containing atherogenic mutation leads to an improvement in mitochondrial function.

BACKGROUND:Mitochondria are the main sites of cellular aerobic energy production through conjugation of respiration and oxidative phosphorylation. We have recently discovered mutations (genome variants) of mitochondrial DNA (mtDNA) associated with atherosclerosis. We have then investigated the possible mechanisms underlying such association and the role of mitochondrial mutations in atherogenesis. Mitochondrial dysfunction is a known component of the pathogenesis of chronic human diseases, including atherosclerosis. OBJECTIVE:The aim of the study was to explore whether there is a relationship between cellular oxygen consumption and atherosclerosis-associated mitochondrial mutations. The study of mitochondrial respiration abnormalities can help to understand the role of mtDNA mutations in pathology. METHODS:By using the polarographic method with Clark electrode, we tested the possibility of respiration impairment in permeabilized cells carrying the tested mtDNA variants using the cybrid (cytoplasmic hybrid) lines. Mitochondria introduced in the cybrid lines were obtained from atherosclerotic patients that differed in the profile of mtDNA mutations, which made it possible to compare the degree of mtDNA mutation load with the rate of oxygen consumption by cybrid cells. RESULTS:It was found that three of the studied mutations were individually associated with impaired respiration. Besides, some combinations of two specific mutations have a high probability of being associated with altered oxygen consumption. As a result, eight mutations were identified, individually or paired combinations of which were associated with high or low rates of cellular respiration, significantly different from control cells. CONCLUSION:The observed effect may be involved in the pathogenesis of atherosclerosis. The study of mtDNA mutations associated with atherosclerosis can help reveal pharmacological targets for the development of novel therapies.

Atherosclerotic cardiovascular disease (ASCVD) is an advanced chronic inflammatory disease and the leading cause of death worldwide. The pathological development of ASCVD begins with atherosclerosis, characterised by a pathological remodelling of the arterial wall, lipid accumulation and build-up of atheromatous plaque. As the disease advances, it narrows the vascular lumen and limits the blood, leading to ischaemic necrosis in coronary arteries. Exosomes are nano-sized lipid vesicles of different origins that can carry many bioactive molecules from their parental cells, thus playing an important role in intercellular communication. The roles of exosomes in atherosclerosis have recently been intensively studied, advancing our understanding of the underlying molecular mechanisms. In this review, we briefly introduce exosome biology and then focus on the roles of exosomes of different cellular origins in atherosclerosis development and progression, functional significance of their cargoes and physiological impact on recipient cells. Studies have demonstrated that exosomes originating from endothelial cells, vascular smooth muscle cells, macrophages, dendritic cells, platelets, stem cells, adipose tissue and other sources play an important role in the atherosclerosis development and progression by affecting cholesterol transport, inflammatory, apoptotic and other aspects of the recipient cells' metabolism. MicroRNAs are considered the most significant type of bioactive molecules transported by exosomes and involved in ASCVD development. Finally, we review the current achievements and limitations associated with the use of exosomes for the diagnosis and treatment of ASCVD.

This review discusses the possibility of inheritance of some diseases through mutations in mitochondrial DNA. These are examples of many mitochondrial diseases that can be caused by mutations in mitochondrial DNA. Symptoms and severity can vary widely depending on the specific mutation and affected tissues. An association between certain mutations in the mitochondrial genome and cancer was reported. In other studies of 2-4 generations in each family, we found that mitochondrial mutations associated with atherosclerosis are inherited. This may at least partially explain the inheritance of predisposition to atherosclerotic disease by maternal line. Furthermore, to prove the important role of mitochondrial mutations in the development of atherosclerotic manifestations at the cellular level, we developed a technique for editing the mitochondrial genome. A recent article described how one of the pro-atherogenic mutations, namely m.15059G>A, was eliminated from such monocyte-derived cells using the technique we developed. Elimination of this mutation resulted in the restoration to normal levels of initially defective mitophagy and impaired inflammatory response. These data strongly suggest that mitochondrial mutations are closely associated with the development of atherosclerotic lesions. Considering that they are inherited, it can be assumed that, at least partly, the genetic predisposition to atherosclerotic diseases is transmitted from mother to offspring. Thus, despite the small size of mitochondrial DNA, its mutations may play a role in the pathogenesis of diseases. Further study of their role will make it possible to consider mitochondrial mutations as promising diagnostic markers and disorders caused by mutations as pharmacological targets.

Аims: This research aimed to study the features of gene regulation of the inflammatory response in cells carrying mitochondrial mutations associated with atherosclerosis. BACKGROUND:Inflammation plays an important, if not decisive, role in the occurrence of atherosclerotic lesions and then accompanies it throughout its further development. Thus, atherogenesis is a chronic inflammatory process. Chronification of inflammation is a consequence of disruption of the normal inflammatory response at the cell level of the vascular wall. OBJECTIVES:In this study, we used cytoplasmic hybrids or cybrids carrying atherosclerosis- associated mitochondrial mutations to study gene regulation of inflammatory response. The main goal of the study was to identify the key genes responsible for the impaired inflammatory response revealed for some cybrids. METHODS:Inflammatory stimulation of cybrids was induced with bacterial lipopolysaccharide, and assessed through secretion of pro-inflammatory cytokines CCL2, IL8, IL6, IL1b. A transcriptome analysis was performed to identify the key genes (master regulators) in the normal (tolerant) and intolerant response of cybrid cells. RESULTS:Normal inflammatory response after re-stimulation elicited a much smaller secretion of pro-inflammatory cytokines. In an intolerant response, the level of secretion upon re-stimulation was the same or even higher than after the first stimulation. Normal and intolerant responses differed significantly both in terms of the number of signaling pathways involved and qualitatively, since the signaling pathways for normal and intolerant responses are completely different. Master regulators controlling normal and intolerant inflammatory response were identified. For a normal response to the first inflammatory stimulation, no common master up-regulators and 3 master down-regulators were identified. The reverse situation was observed with the intolerant inflammatory response: 6 master up-regulators, and no master down regulators were identified. After the second inflammatory stimulation, no master regulator common to all studied cytokines was found. Thus, key genes involved in the development of intolerant inflammatory response have been identified. In addition, other key genes were identified that were initially associated with an intolerant inflammatory response and thus determine disorders of the inflammatory reaction leading to chronification of inflammation. CONCLUSION:We identified disturbances in gene associated with the development of intolerant immune response that may be relevant to atherosclerosis. Key genes responsible for the chronification of inflammation were discovered.

Atherosclerosis poses a significant challenge to the general population, with its prevalence particularly prominent among older individuals. Age, however, is not the sole determinant of risk, as gender also plays a crucial role. Sex-related disparities exist not only in the incidence of atherosclerosis but also in its progression and development. The intricate interplay of hormones in the female reproductive system contributes to its proper functioning. Perturbations in this hormonal system can give rise to disorders and conditions that influence the susceptibility to various diseases, including cardiovascular disorders. Such conditions encompass both natural occurrences like menopause as well as pathological conditions such as polycystic ovarian syndrome. This comprehensive review delves into the examination of hormonal imbalances in females as risk factors and compiles pertinent information regarding the role of key hormones, particularly estrogen and its derivatives, in the context of atherosclerosis. The review article not only highlights the impact of hormonal imbalances on the risk of developing atherosclerosis but also provides comprehensive insights into the specific mechanisms underlying estrogen's role in the disease process. Additionally, it explores the influence of other major hormones, expanding the understanding of their contributions to atherosclerosis. To select the initial literature sources, we searched the PubMed database with the following keywords and their combinations: "Female hormones", "atherosclerosis", "sex as a risk factor", and "estrogen". Using this search, we chose several papers, from the analysis of which we started this review. Moving through these papers, we developed the structure of the review.

BACKGROUND AND AIMS:The role of mitophagy in atherosclerosis has been extensively studied during the last few years. It was shown that mitophagy is involved in the regulation of macrophages, which are important players as immune cells in atherosclerosis development. In this study, we investigated the relationship between mitophagy and response to inflammatory stimulation of macrophage-like cells. Six cybrid cell lines with normal mitophagy, that is, increasing in response to stimulation, and 7 lines with defective mitophagy not responding to stimulation were obtained. The objective of the study was to compare the nature of the inflammatory response in normal and defective mitophagy in order to elucidate the role of mitophagy defects in inflammation. METHODS:We used cytoplasmic hybrids (cybrids) as cellular models, created using mitochondrial DNA from different atherosclerosis patients. Mitophagy was stimulated by carbonyl cyanide m-chlorophenyl hydrazone (CCCP) and assessed as the degree of colocalization of mitochondria with lysosomes using confocal microscopy. Western blotting methods were used for the determination of proteins involved in the exact mechanism of mitophagy. Experiments with stimulation of mitophagy show a high correlation between these two approaches (microscopy and blotting). The pro-inflammatory response of cybrids was stimulated with bacterial lipopolysaccharide (LPS). The extent of the inflammatory response was assessed by the secretion of cytokines CCL2, IL8, IL6, IL1β, and TNF measured by ELISA. RESULTS:Basal level of secretion of cytokines CCL2, IL8 and TNF was 1.5-2 times higher in cultures of cybrids with defective mitophagy compared to cells with normal mitophagy. This suggests a persistently elevated inflammatory response in cells with defective mitophagy, even in the absence of an inflammatory stimulus. Such cells in the tissue will constantly recruit other immune cells, which is characteristic of macrophages derived from monocytes circulating in the blood of patients with atherosclerosis. We observed significant differences in the degree and type of response to inflammatory activation in cybrids with defective mitophagy. These differences were not so much quantitative as they were dramatically qualitative. Compared with cells with normal mitophagy, in cells with defective mitophagy, the relative (to basal) secretion of IL8, IL6 and IL1b increased after the second LPS activation. This indicates a possible lack of tolerance to inflammatory activation in cells with defective mitophagy, since typically, re-activation reveals a smaller pro-inflammatory cytokine response, allowing the inflammatory process to resolve. In cells with normal mitophagy, exactly this normal (tolerant) inflammatory reaction was observed. CONCLUSION:Data on the involvement of mitophagy, including defective mitophagy, in disturbances of the inflammatory response in sepsis, viral infections, autoimmune diseases and other pathologies have previously been reported. In this work, we studied the role of defective mitophagy in non-infectious chronic inflammatory diseases using the example of atherosclerosis. We showed a dramatic disruption of the inflammatory response associated with defective mitophagy. Compared with cybrids with normal mitophagy, in cybrids with defective mitophagy, the secretion of all studied cytokines changed significantly both quantitatively and qualitatively. In particular, the secretion of 3 of 5 cytokines demonstrated an intolerant inflammatory response manifested by increased secretion after repeated inflammatory stimulation. Such an intolerant reaction likely indicates a significant disruption of the pro-inflammatory response of macrophages, which can contribute to the chronification of inflammation. Elucidating the mechanisms of chronification of inflammation is extremely important for the search for fundamentally new pharmacological targets and the development of drugs for the prevention and treatment of chronic inflammatory diseases, including atherosclerosis and diseases characteristic of inflammation. Such diseases account for up to 80% of morbidity and mortality.

Mediterranean diet is frequently associated with longevity and a lower incidence of adverse cardiovascular events because of the biological activities and health effects of olives - its key component. Olive oil, olive leaf extract, fruits and different by-products contain many bioactive components that exert anti-oxidant, anti-inflammatory and anti-apoptotic activities. In this review, we focus on the recent studies exploring molecular mechanisms underlying the cardioprotective properties of different olive oils, olive leave extracts, and specific micro-constituents (such as oleuropein, tyrosol, hydroxytyrosol and others) in vitro on rodent models and in clinical trials on human subjects. Particularly, hydroxytyrosol and oleuropein were identified as the major bioactive compounds responsible for the antioxidant, anti-inflammatory, anti-platelet aggregation and anti-atherogenic activities of olive oil. In total, the discussed results demonstrated a positive association between the consumption of olive oil and improvement in outcomes in atherosclerosis, diabetes, myocardial infarction, heart failure, hypertension and obesity.

Background: The relationship between the cellular pro-inflammatory response and intracellular lipid accumulation in atherosclerosis is not sufficiently studied. Transcriptomic analysis is one way to establish such a relationship. Previously, we identified 10 potential key genes (IL-15, CXCL8, PERK, IL-7, IL-7R, DUSP1, TIGIT, F2RL1, TSPYL2, and ANXA1) involved in cholesterol accumulation in macrophages. It should be noted that all these genes do not directly participate in cholesterol metabolism, but encode molecules related to inflammation. Methods: In this study, we conducted a knock-down of the 10 identified key genes using siRNA to determine their possible role in cholesterol accumulation in macrophages. To assess cholesterol accumulation, human monocyte-derived macrophages (MDM) were incubated with atherogenic LDL from patients with atherosclerosis. Cholesterol content was assessed by the enzymatic method. Differentially expressed genes were identified with DESeq2 analysis. Master genes were determined by the functional analysis. Results: We found that only 5 out of 10 genes (IL-15, PERK, IL-7, IL-7R, ANXA1) can affect intracellular lipid accumulation. Knock-down of the IL-15, PERK, and ANXA1 genes prevented lipid accumulation, while knock-down of the IL-7 and IL-7R genes led to increased intracellular lipid accumulation during incubation of MDM with atherogenic LDL. Seventeen overexpressed genes and 189 underexpressed genes were obtained in the DGE analysis, which allowed us to discover 20 upregulated and 86 downregulated metabolic pathways, a number of which are associated with chronic inflammation and insulin signaling. We also elucidated 13 master regulators of cholesterol accumulation that are immune response-associated genes. Conclusion: Thus, it was discovered that 5 inflammation-related master regulators may be involved in lipid accumulation in macrophages. Therefore, the pro-inflammatory response of macrophages may trigger foam cell formation rather than the other way around, where intracellular lipid accumulation causes an inflammatory response, as previously assumed.

Dyslipidemia is one of the key features in the pathogenesis of atherosclerosis, however, many points in the progression of this pathological phenomenon remain unclear. In this review, we will consider the significance of various lipoproteins in the progression of atherosclerosis, the general pattern of dyslipidemia development and its role in the pathogenesis of atherosclerosis, as well as new approaches to the treatment of dyslipidemia, which will potentially reduce the disadvantages of existing therapies and increase drug efficacy.

Objective:The aim of this study was to evaluate the effect of the m.15059G>A mitochondrial nonsense mutation on cellular functions related to atherosclerosis, such as lipidosis, pro-inflammatory response, and mitophagy. Heteroplasmic mutations have been proposed as a potential cause of mitochondrial dysfunction, potentially disrupting the innate immune response and contributing to the chronic inflammation associated with atherosclerosis.Methods:The human monocytic cell line THP-1 and cytoplasmic hybrid cell line TC-HSMAM1 were used. An original approach based on the CRISPR/Cas9 system was developed and used to eliminate mitochondrial DNA (mtDNA) copies carrying the m.15059G>A mutation in the MT-CYB gene. The expression levels of genes encoding enzymes related to cholesterol metabolism were analyzed using quantitative polymerase chain reaction. Pro-inflammatory cytokine secretion was assessed using enzyme-linked immunosorbent assays. Mitophagy in cells was detected using confocal microscopy.Results:In contrast to intact TC-HSMAM1 cybrids, Cas9-TC-HSMAM1 cells exhibited a decrease in fatty acid synthase (FASN) gene expression following incubation with atherogenic low-density lipoprotein. TC-HSMAM1 cybrids were found to have defective mitophagy and an inability to downregulate the production of pro-inflammatory cytokines (to establish immune tolerance) upon repeated lipopolysaccharide stimulation. Removal of mtDNA harboring the m.15059G>A mutation resulted in the re-establishment of immune tolerance and the activation of mitophagy in the cells under investigation.Conclusion:The m.15059G>A mutation was found to be associated with defective mitophagy, immune tolerance, and impaired metabolism of intracellular lipids due to upregulation of FASN in monocytes and macrophages.

Atherosclerosis is a widespread and serious problem. Every year it causes a huge number of deaths and morbidity. Many aspects of this disease remain not fully understood, which indicates the need to search for the most representative model of atherosclerosis in animal and cell culture models. Animal models resembling the pathophysiology in humans are needed to study the immunometabolic mechanisms and molecular processes mediating the development of the disorder. It's important to point out that no animal model replicates all the attributes of the human disease. Various animal atherosclerosis models have been tested, each of them having its advantages and disadvantages. The use of animal models adheres to ethical guidelines and regulations. Mice are traditionally considered one of the most convenient model objects, including for the study of atherosclerosis. Murine models are relatively cheap, fast-growing, and can be easily manipulated. Nevertheless, there exist numerous limitations when employing murine models. One example of a limitation is that, unlike humans, mice primarily transfer cholesterol in High-Density Lipoprotein (HDL) particles rather than Low-Density Lipoprotein (LDL). There is still no ideal model, even though plenty of them are used for various studies. Within this review, we have compiled pertinent background details concerning the prevailing mouse models employed in atherosclerosis research. We aim to emphasize the benefits and drawbacks associated with their utilization.