Monocyte adhesion to the endothelium is an initial stage of atherosclerosis development

Cardiovascular disease and thrombosis: Intersections with the immune system, inflammation, and the coagulation system

The coagulation and immune system, both essential physiological systems in the human body, are intricately interconnected and play a critical role in determining the overall health of patients. These systems collaborate via various shared regulatory pathways, such as the Tissue Factor (TF) Pathway. Immunological cells that express TF and generate pro-inflammatory cytokines have the ability to affect coagulation. Conversely, coagulation factors and processes have a reciprocal effect on immunological responses by stimulating immune cells and regulating their functions. These interconnected pathways play a role in both preserving well-being and contributing to a range of pathological disorders. The close relationship between blood clotting and inflammation in the development of vascular disease has become a central focus of clinical study. This research specifically examines the crucial elements of this interaction within the contexts of cardiovascular disease and acute coronary syndrome. Tissue factor, the primary trigger of the extrinsic coagulation pathway, has a crucial function by inducing a proinflammatory reaction through the activation of coagulation factors. This, in turn, initiates coagulation and subsequent cellular signalling pathways. Protease-activated receptors establish the molecular connection between coagulation and inflammation by interacting with activated clotting factors II, X, and VII. Thrombosis, a condition characterised by the formation of blood clots, is the most dreaded consequence of cardiovascular disorders and a leading cause of death globally. Consequently, it poses a significant challenge to healthcare systems. Antithrombotic treatments efficiently target platelets and the coagulation cascade, but they come with the inherent danger of causing bleeding. Furthermore, antithrombotics are unable to fully eliminate thrombotic events, highlighting a treatment deficiency caused by a third mechanism that has not yet been sufficiently addressed, namely inflammation. Understanding these connections may aid in the development of novel approaches to mitigate the harmful mutual exacerbation of inflammation and coagulation. Gaining a comprehensive understanding of the intricate interaction among these systems is crucial for the management of diseases and the creation of efficacious remedies. Through the examination of these prevalent regulatory systems, we can discover novel therapeutic approaches that specifically target these complex illnesses. This paper provides a thorough examination of the reciprocal relationship between the coagulation and immune systems, emphasising its importance in maintaining health and understanding disease processes. This review examines the interplay between inflammation and thrombosis and its role in the development of thrombotic disorders.

Plastic particle impacts on the cardiovascular system and angiogenesis potential

The extensive application of plastics in different sectors such as packaging, building, textiles, consumer products, and several industries has increased in recent years. Emerging data have confirmed that plastic wastes and segregates are problematic issues in aquatic and terrestrial ecosystems. The decomposition of plastic particles (PPs) leads to the release of microplastics (MPs) and nanoplastics (NPs) into the surrounding environment and entry of these particles will be problematic in unicellular and multicellular creatures. It was suggested that PPs can easily cross all biological barriers and reach different organs, especially the cardiovascular system, with the potential to modulate several molecular pathways. It is postulated that the direct interaction of PPs with cellular and subcellular components induces genotoxicity and cytotoxicity within the cardiovascular system. Meanwhile, being inert carriers, PPs can intensify the toxicity of other contaminants inside the cardiovascular system. Here, in this review article, several underlying mechanisms related to PP toxicity in the cardiovascular system were discussed in detail.

Sesame oil downregulates the expression of ADAMTS-4 in high-fat diet-induced atherosclerosis

Atherosclerosis is a chronic inflammatory disease forming plaques in medium and large-sized arteries. ADAMTS-4 (a disintegrin and metalloproteinase with thrombospondin motifs-4) is an extracellular-matrix remodelling enzyme involved in the degradation of versican in the arterial wall. Recent reports indicated that increased expression of ADAMTS-4 is associated with plaque progression and vulnerability. Bioactive components of dietary oil, like sesame oil, are reported to have anti-inflammatory and antioxidant properties. Here, we studied the effect of sesame oil on regulating ADAMTS-4 in high-fat diet-induced atherosclerosis rat model. Our results indicated that sesame oil supplementation improved the anti-inflammatory and anti-oxidative status of the body. It also reduced atherosclerotic plaque formation in high-fat diet-fed rats. Our results showed that the sesame oil supplementation significantly down-regulated the expression of ADAMTS-4 in serum and aortic samples. The versican, the large proteoglycan substrate of ADAMTS-4 in the aorta, was downregulated to normal control level on sesame oil supplementation. This study, for the first time, reveals that sesame oil could down-regulate the expression of ADAMTS-4 in high-fat diet-induced atherosclerosis, imparting a new therapeutic potential for sesame oil in the management of atherosclerosis.

Long COVID Definition, Symptoms, Risk Factors, Epidemiology and Autoimmunity: A Narrative Review

The virus called SARS-CoV-2 emerged in 2019 and quickly spread worldwide, causing COVID-19. It has greatly impacted on everyday life, healthcare systems, and the global economy. In order to save as many lives as possible, precautions such as social distancing, quarantine, and testing policies were implemented, and effective vaccines were developed. A growing amount of data collected worldwide allowed the characterization of this new disease, which turned out to be more complex than other common respiratory tract infections. An increasing number of convalescents presented with a variety of nonspecific symptoms emerging after the acute infection. This possible new global health problem was identified and labelled as long COVID. Since then, a great effort has been made by clinicians and the scientific community to understand the underlying mechanisms and to develop preventive measures and effective treatment. The role of autoimmunity induced by SARS-CoV-2 infection in the development of long COVID is discussed in this review. We aim to deliver a description of several conditions with an autoimmune background observed in COVID-19 convalescents, including Guillain-Barré syndrome, antiphospholipid syndrome and related thrombosis, and Kawasaki disease highlighting a relationship between SARS-CoV-2 infection and the development of autoimmunity. However, further studies are required to determine its true clinical significance.

Actinidia arguta Extract Containing Myo-Inositol Suppresses TNF-α-Induced VCAM-1 Expression and Monocyte Adhesion to Endothelial Cells via Inhibition of the PTEN/Akt/GSK-3β and NF-κB Signaling Pathways

The primary inflammatory process in atherosclerosis, a major contributor to cardiovascular disease, begins with monocyte adhering to vascular endothelial cells. Actinidia arguta (kiwiberry) is an edible fruit that contains various bioactive components. While A. arguta extract (AAE) has been recognized for its anti-inflammatory characteristics, its specific inhibitory effect on early atherogenic events has not been clarified. We used tumor necrosis factor-α (TNF-α)-stimulated human umbilical vein endothelial cells (HUVECs) for an in vitro model. AAE effectively hindered the attachment of THP-1 monocytes and reduced the expression of vascular cell adhesion molecule-1 (VCAM-1) in HUVECs. Transcriptome analysis revealed that AAE treatment upregulated phosphatase and tensin homolog (PTEN), subsequently inhibiting phosphorylation of AKT and glycogen synthase kinase 3β (GSK3β) in HUVECs. AAE further hindered phosphorylation of AKT downstream of the nuclear factor kappa B (NF-κB) signaling pathway, leading to suppression of target gene expression. Oral administration of AAE suppressed TNF-α-stimulated VCAM-1 expression, monocyte-derived macrophage infiltration, and proinflammatory cytokine expression in C57BL/6 mouse aortas. Myo-inositol, identified as the major compound in AAE, played a key role in suppressing THP-1 monocyte adhesion in HUVECs. These findings suggest that AAE could serve as a nutraceutical for preventing atherosclerosis by inhibiting its initial pathogenesis.

Heparanase promotes the onset and progression of atherosclerosis in apolipoprotein E gene knockout mice

BACKGROUND AND AIMS

Atherosclerosis is the primary underlying cause of myocardial infarction and stroke, which are the major causes of death globally. Heparanase (Hpse) is a pro-inflammatory extracellular matrix degrading enzyme that has been implicated in atherogenesis. However, to date the precise roles of Hpse in atherosclerosis and its mechanisms of action are not well defined. This study aims to provide new insights into the contribution of Hpse in different stages of atherosclerosis in vivo.

METHODS

We generated Hpse gene-deficient mice on the atherosclerosis-prone apolipoprotein E gene knockout (ApoE-/-) background to investigate the impact of Hpse gene deficiency on the initiation and progression of atherosclerosis after 6 and 14 weeks high-fat diet feeding, respectively. Atherosclerotic lesion development, blood serum profiles, lesion composition and aortic immune cell populations were evaluated.

RESULTS

Hpse-deficient mice exhibited significantly reduced atherosclerotic lesion burden in the aortic sinus and aorta at both time-points, independent of changes in plasma cholesterol levels. A significant reduction in the necrotic core size and an increase in smooth muscle cell content were also observed in advanced atherosclerotic plaques of Hpse-deficient mice. Additionally, Hpse deficiency reduced circulating and aortic levels of VCAM-1 at the initiation and progression stages of disease and circulating MCP-1 levels in the initiation but not progression stage. Moreover, the aortic levels of total leukocytes and dendritic cells in Hpse-deficient ApoE-/- mice were significantly decreased compared to control ApoE-/-mice at both disease stages.

CONCLUSIONS

This study identifies Hpse as a key pro-inflammatory enzyme driving the initiation and progression of atherosclerosis and highlighting the potential of Hpse inhibitors as novel anti-inflammatory treatments for cardiovascular disease.

Haplo-insufficiency of Profilin1 in vascular endothelial cells is beneficial but not sufficient to confer protection against experimentally induced atherosclerosis

Actin cytoskeleton plays an important role in various aspects of atherosclerosis, a key driver of ischemic heart disease. Actin-binding protein Profilin1 (Pfn1) is overexpressed in atherosclerotic plaques in human disease, and Pfn1, when partially depleted globally in all cell types, confers atheroprotection in vivo . This study investigates the impact of endothelial cell (EC)-specific partial loss of Pfn1 expression in atherosclerosis development. We utilized mice engineered for conditional heterozygous knockout of the Pfn1 gene in ECs, with atherosclerosis induced by depletion of hepatic LDL receptor by gene delivery of PCSK9 combined with high-cholesterol diet. Our studies show that partial depletion of EC Pfn1 has certain beneficial effects marked by dampening of select pro-atherogenic cytokines (CXCL10 and IL7) with concomitant reduction in cytotoxic T cell abundance but is not sufficient to reduce hyperlipidemia and confer atheroprotection in vivo . In light of these findings, we conclude that atheroprotective phenotype conferred by global Pfn1 haplo-insufficiency requires contributions of additional cell types that are relevant for atherosclerosis progression.

Diethylaminoethyl-dextran and monocyte cell membrane coated 1,8-cineole delivery system for intracellular delivery and synergistic treatment of atherosclerosis

We have developed a biomimetic delivery system termed the Monocyte Cell Membrane-Coated 1,8-Cineole Biomimetic Delivery System (MM-CIN-BDS or BDS), which integrates diethylaminoethyl-dextran (DEAE) and monocyte cell membrane (MM). This innovative approach enhances the cellular uptake efficiency of 1,8-cineole (CIN) and facilitates targeted therapy for atherosclerosis. Our findings demonstrate the successful modification of the drug carrier with DEAE and MM, as validated by measurements of particle size, zeta potential, microscopic morphology, and western blotting analyses. Notably, cellular uptake experiments unveil a significant enhancement in cellular uptake efficiency due to DEAE modification. However, the introduction of monocyte cell membranes diminishes this effect in normal human umbilical vein endothelial cells (HUVECs), although this efficiency is notably restored in HUVECs activated with lipopolysaccharide (LPS). Through in vivo imaging investigations, we observe that the MM coating augments distribution in the spleen, brain, and atherosclerotic plaques, while concurrently diminishing distribution in the heart and kidneys. Animal studies corroborate these findings, illustrating that MM-CIN-BDS treatment curtails lipid parameters, dampens the expression of inflammatory factors and proteins, mitigates vascular tissue damage, and ultimately reduces the extent of atherosclerotic lesion areas. To encapsulate, DEAE emerges as an especially adept agent for modifying drug carriers with suboptimal cellular uptake efficiency in the realm of cardiovascular diseases. The potential therapeutic promise of MM-CIN-BDS for atherosclerosis treatment is evident from our research.

Protective effects of blueberries on vascular function: A narrative review of preclinical and clinical evidence

Blueberries are rich in nutrients and (poly)phenols, popular with consumers, and a major agricultural crop with year-round availability supporting their use in food-based strategies to promote human health. Accumulating evidence indicates blueberry consumption has protective effects on cardiovascular health including vascular dysfunction (i.e., endothelial dysfunction and arterial stiffening). This narrative review synthesizes evidence on blueberries and vascular function and provides insight into underlying mechanisms with a focus on oxidative stress, inflammation, and gut microbiota. Evidence from animal studies supports beneficial impacts on vascular function. Human studies indicate acute and chronic blueberry consumption can improve endothelial function in healthy and at-risk populations and may modulate arterial stiffness, but that evidence is less certain. Results from cell, animal, and human studies suggest blueberry consumption improves vascular function through improving nitric oxide bioavailability, oxidative stress, and inflammation. Limited data in animals suggest the gut microbiome mediates beneficial effects of blueberries on vascular function; however, there is a paucity of studies evaluating the gut microbiome in humans. Translational evidence indicates anthocyanin metabolites mediate effects of blueberries on endothelial function, though this does not exclude potential synergistic and/or additive effects of other blueberry components. Further research is needed to establish the clinical efficacy of blueberries to improve vascular function in diverse human populations in a manner that provides mechanistic information. Translation of clinical research to the community/public should consider feasibility, social determinants of health, culture, community needs, assets, and desires, barriers, and drivers to consumption, among other factors to establish real-world impacts of blueberry consumption.

The Crossroads of the Coagulation System and the Immune System: Interactions and Connections

The coagulation and immune systems, two vital systems in the human body, share intimate connections that fundamentally determine patient health. These systems work together through several common regulatory pathways, including the Tissue Factor (TF) Pathway. Immune cells expressing TF and producing pro-inflammatory cytokines can influence coagulation, while coagulation factors and processes reciprocally impact immune responses by activating immune cells and controlling their functions. These shared pathways contribute to maintaining health and are also involved in various pathological conditions. Dysregulated coagulation, triggered by infection, inflammation, or tissue damage, can result in conditions such as disseminated intravascular coagulation (DIC). Concurrently, immune dysregulation may lead to coagulation disorders and thrombotic complications. This review elucidates these intricate interactions, emphasizing their roles in the pathogenesis of autoimmune diseases and cancer. Understanding the complex interplay between these systems is critical for disease management and the development of effective treatments. By exploring these common regulatory mechanisms, we can uncover innovative therapeutic strategies targeting these intricate disorders. Thus, this paper presents a comprehensive overview of the mutual interaction between the coagulation and immune systems, highlighting its significance in health maintenance and disease pathology.

SVEP1 influences monocyte to macrophage differentiation via integrin α4β1/α9β1 and Rho/Rac signalling

BACKGROUND

The large extracellular matrix protein SVEP1 mediates cell adhesion via integrin α9β1. Recent studies have identified an association between a missense variant in SVEP1 and increased risk of coronary artery disease (CAD) in humans and in mice Svep1 deficiency alters the development of atherosclerotic plaques. However how SVEP1 functionally contributes to CAD pathogenesis is not fully understood. Monocyte recruitment and differentiation to macrophages is a key step in the development of atherosclerosis. Here, we investigated the requirement for SVEP1 in this process.

METHODS

SVEP1 expression was measured during monocyte-macrophage differentiation in primary monocytes and THP-1 human monocytic cells. SVEP1 knockout THP-1 cell lines and the dual integrin α4β1/α9β1 inhibitor, BOP, were utilised to investigate the effect of these proteins in THP-1 cell adhesion, migration and cell spreading assays. Subsequent activation of downstream integrin signalling intermediaries was quantified by western blotting.

RESULTS

SVEP1 gene expression increases in monocyte to macrophage differentiation in human primary monocytes and THP-1 cells. Using two SVEP1 knockout THP-1 cells we observed reduction in monocyte adhesion, migration, and cell spreading compared to control cells. Similar results were found with integrin α4β1/α9β1 inhibition. We demonstrate reduced activity of Rho and Rac1 in SVEP1 knockout THP-1 cells.

CONCLUSIONS

SVEP1 regulates monocyte recruitment and differentiation phenotypes through an integrin α4β1/α9β1 dependent mechanism.

GENERAL SIGNIFICANCE

These results describe a novel role for SVEP1 in monocyte behaviour relevant to CAD pathophysiology.

Effects of quercetin supplementation on endothelial dysfunction biomarkers and depression in post-myocardial infarction patients: A double-blind, placebo-controlled, randomized clinical trial

BACKGROUND

Endothelial dysfunction and depression are highly prevalent in patients who have experienced a myocardial infarction (MI). Epidemiological studies have pointed out that a diet rich in flavonoids, e.g., quercetin, can prevent the development of these biological phenomena. Therefore, we aimed to investigate the effects of quercetin supplementation on the levels of intercellular adhesion molecule 1 (ICAM-1) and vascular cell adhesion molecule 1 (VCAM-1) and on depression in post-MI subjects.

METHODS

Eighty-eight post-MI patients who had experienced their first MI (body mass index ≤35 kg/m², age 30-65 years) were recruited from the Rasool-e-Akram and Afshar Hospitals, Iran, and included in this randomized, placebo-controlled, double-blind parallel study. The participants were randomly assigned to receive a daily dose of 500 mg quercetin (n = 44) or placebo (n = 44) for 8 weeks. Serum concentrations of ICAM-1 and VCAM-1 were quantified by ELISA and depression levels were assessed using the Beck's Depression Inventory (BDI-II) questionnaire at baseline and at 8-week follow-up.

RESULTS

Seventy-six participants completed the study, but the intention-to-treat (ITT) analysis was conducted for all 88 participants who were randomized into the intervention groups. No significant changes in serum concentrations of ICAM-1 or VCAM-1 (P = 0.21 and P = 0.80, respectively) were observed after 8 weeks of quercetin supplementation versus placebo. In addition, depression levels did not differ significantly between the quercetin and placebo groups.

CONCLUSION

Our findings demonstrated that in post-MI patients, daily supplementation with quercetin (500 mg/day) for 8 weeks did not affect endothelial dysfunction biomarkers and depression levels. This trial was registered at IRCT.ir as IRCT20190428043405N1.

Cellular crosstalk in atherosclerotic plaque microenvironment

Atherosclerosis is an underlying pathology of many vascular diseases as a result of cellular, structural and molecular dysfunctions within the sub-endothelial space. This review deals with the events involved in the formation, growth and remodeling of plaque, including the cell recruitment, cell polarization, and cell fat droplets. It also describes cross talking between endothelial cells, macrophages, and vascular smooth muscle cells, as well as the cellular pathways involved in plaque development in the plaque microenvironment. Finally, it describes the plaque structural components and the role of factors involved in the rupture and erosion of plaques in the vessel. Video Abstract.

Beyond Pattern Recognition: TLR2 Promotes Chemotaxis, Cell Adhesion, and Migration in THP-1 Cells

The interaction between monocytes and endothelial cells in inflammation is central to chemoattraction, adhesion, and transendothelial migration. Key players, such as selectins and their ligands, integrins, and other adhesion molecules, and their functions in these processes are well studied. Toll-like receptor 2 (TLR2), expressed in monocytes, is critical for sensing invading pathogens and initiating a rapid and effective immune response. However, the extended role of TLR2 in monocyte adhesion and migration has only been partially elucidated. To address this question, we performed several functional cell-based assays using monocyte-like wild type (WT), TLR2 knock-out (KO), and TLR2 knock-in (KI) THP-1 cells. We found that TLR2 promotes the faster and stronger adhesion of monocytes to the endothelium and a more intense endothelial barrier disruption after endothelial activation. In addition, we performed quantitative mass spectrometry, STRING protein analysis, and RT-qPCR, which not only revealed the association of TLR2 with specific integrins but also uncovered novel proteins affected by TLR2. In conclusion, we show that unstimulated TLR2 influences cell adhesion, endothelial barrier disruption, migration, and actin polymerization.

Comparative study of the effects of cigarette smoke versus next-generation tobacco and nicotine product extracts on inflammatory biomarkers of human monocytes

Monocytes exhibiting a pro-inflammatory phenotype play a key role in adhesion and development of atherosclerotic plaques. As an alternative to smoking, next-generation tobacco and nicotine products (NGP) are now widely used. However, little is known about their pro-inflammatory effects on monocytes. We investigated cell viability, anti-oxidant and pro-inflammatory gene and protein expression in THP-1 monocytes after exposure to aqueous smoke extracts (AqE) of a heated tobacco product (HTP), an electronic cigarette (e-cig), a conventional cigarette (3R4F) and pure nicotine (nic). Treatment with 3R4F reduced cell viability in a dose-dependent manner, whereas exposure to alternative smoking products showed no difference to control. At the highest non-lethal dose of 3R4F (20%), the following notable mRNA expression changes were observed for 3R4F, HTP, and e-cig respectively, relative to control; HMOX1 (6-fold, < 2-fold, < 2-fold), NQO1 (3.5-fold, < 2-fold, < 2-fold), CCL2 (4-fold, 3.5-fold, 2.5-fold), IL1B (4-fold, 3-fold, < 2-fold), IL8 (5-fold, 2-fold, 2-fold), TNF (2-fold, 2-fold, < 2-fold) and ICAM1 was below the 2-fold threshold for all products. With respect to protein expression, IL1B (3-fold, < 2-fold, < 2-fold) and IL8 (3.5-fold, 2-fold, 2-fold) were elevated over the 2-fold threshold, whereas CCL2, TNF, and ICAM1 were below 2-fold expression for all products. At higher doses, greater inductions were observed with all extracts; however, NGP responses were typically lower than 3R4F. In conclusion, anti-oxidative and pro-inflammatory processes were activated by all products. NGPs overall showed lower responses relative to controls than THP-1 cells exposed to 3R4F AqE.

Placenta-derived extracellular vesicles from preeclamptic and healthy pregnancies impair ex vivo vascular endothelial function

Preeclampsia (PE) is a pregnancy syndrome characterized by new-onset hypertension and end-organ dysfunction. The pathophysiology of PE remains undetermined, but it is thought that maternal vascular dysfunction plays a central role, potentially due, in part, to the release of syncytiotrophoblast-derived extracellular vesicles (STBEVs) into the maternal circulation by a dysfunctional placenta. STBEVs from normal pregnancies (NP) impair vascular function, but the effect of PE STBEVs (known to differ in composition with elevated circulating levels) on vascular function are not known. We hypothesized that PE STBEVs have more detrimental effects on vascular function compared with NP STBEVs. STBEVs were collected by perfusion of placentas from women with NP or PE. Mesenteric arteries from pregnant rats were incubated overnight with NP or PE STBEVs, and vascular function was assessed by wire myography. NP and PE STBEVs impaired endothelial function, partially by reducing nitric oxide (NO) bioavailability. Incubation of human umbilical vein endothelial cells with NP and PE STBEVs increased nuclear factor κ-light-chain-enhancer of activated B cell (NF-κB) activation, reactive oxygen species, nitrotyrosine levels, and reduced NO levels. However, PE STBEVs increased NF-κB activation and nitrotyrosine levels to a lesser extent than NP STBEVs. Taken together, no greater impact of PE STBEVs compared with NP STBEVs on endothelial function was found. However, the impaired vascular function by PE STBEVs and increased levels of STBEVs in PE suggest PE STBEVs may contribute to maternal vascular dysfunction in PE. Our study further expands on the potential mechanisms that lead to adverse outcomes in PE and provides potential targets for future interventions.

Hydroxychloroquine reduces soluble Flt-1 secretion from human cytotrophoblast, but does not mitigate markers of endothelial dysfunction in vitro

Preeclampsia is a multi-system disease that can have severe, even fatal implications for the mother and fetus. Abnormal placentation can lead to ischaemic tissue injury and placental inflammation. In turn, the placenta releases anti-angiogenic factors into the maternal circulation. These systemically act to neutralise angiogenic factors causing endothelial dysfunction causing preeclampsia. Hydroxychloroquine is an immune modulating drug that is considered safe in pregnancy. There is epidemiological evidence suggesting it may reduce the risk of preeclampsia. Here, we examined the effects hydroxychloroquine on the production and secretion of sFlt-1, soluble endoglin (sENG), placental growth factor (PlGF) and vascular endothelial growth factor (VEGF) in primary human placenta, cytotrophoblasts and umbilical vein endothelial cells (endothelial cell model). Hydroxychloroquine treatment decreased mRNA expression of two sFlt-1 isoforms and its protein secretion. sENG was not reduced. Hydroxychloroquine treatment increased secretion of pro-angiogenic factor PIGF from endothelial cells. It did not significantly reduce the expression of the endothelial cell inflammation marker, ET-1, and inflammation induced expression of the adhesion molecule, VCAM. Hydroxychloroquine could not overcome leukocyte adhesion to endothelial cells. Hydroxychloroquine mitigates features of preeclampsia, but it does not reduce key markers of endothelial dysfunction.

EFFECTS OF PALM OIL DERIVED TOCOTRIENOL RICH FRACTION AND VITAMIN E ISOMERS ON BIOMARKERS OF EARLY ATHEROGENESIS IN STIMULATED HUMAN UMBILICAL VEIN ENDOTHELIAL CELLS

This study was conducted to investigate the effects of tocotrienol rich fraction (TRF), α-TOC, and pure TCT isomers (α-. γ- & δ-TCT) on inflammation, endothelial activation, nuclear factor kappa B (NFκB), endothelial nitric oxide synthase (eNOS) and monocyte binding activity (MBA) in vitro. Human umbilical vein endothelial cells (HUVECs) were incubated with various concentrations of α-TOC, pure TCT isomers and TRF (0.3-10 µM) together with lipopolysaccharides (LPS) for 16 h. Culture medium and cells were collected and measured for the protein and gene expression of IL-6, TNF-α, NFκB, ICAM-1, VCAM-1, e-selectin, and eNOS. Monocyte binding activity (MBA) was measured by Rose Bengal staining. Area under the curve (AUC) analysis revealed that TRF and pure TCT particularly γ- and δ- isomers, showed better inhibition of inflammation and endothelial activation, MBA and greater eNOS increment than α-TOC. These suggest that TRF and pure TCT isomers have potential as preventive anti-atherogenic agents by attenuating the release of early biomarkers of atherogenesis which is better than α-TOC in LPS-stimulated human endothelial cells.   

Lack of NPR1 Increases Vascular Endothelial Adhesion through Induction of Integrin Beta 4

Natriuretic peptide receptor 1 (NPR1) serves as a modulator of vascular endothelial homeostasis. Interactions between monocytes and endothelial cells may initiate endothelium dysfunction, which is known as an early hallmark of atherosclerosis. In this study, we performed RNA-sequencing analysis for the aorta of Npr1 knockout (Npr1^+/−) mice and found that differentially expressed genes were significantly related to cell adhesion. This result was supported by an increased expression of intercellular adhesion molecule 1 (ICAM-1) in the aortic endothelium of Npr1^+/− mice. Moreover, we observed that the knockdown of NPR1 increased ICAM-1 expression and promoted THP-1 monocyte adhesion to human umbilical vein endothelial cells (HUVECs). NPR1 overexpression decreased ICAM-1 expression and inhibited the adhesion of monocytes to HUVECs treated by TNF-α (a cell adhesion inducer). Further analysis showed that adhesion-related genes were enriched in the focal adhesion signaling pathway, in which integrin beta 4 (Itgb4) was determined as a key gene. Notably, ITGB4 expression increased in vascular endothelium of Npr1^+/− mice and in NPR1-knockdown HUVECs. The deficiency of ITGB4 decreased ICAM-1 expression and attenuated monocyte adhesion to NPR1-knockdown endothelial cells. Additionally, a reduced NPR1 and an increased ITGB4 expression level were found in an atherosclerosis mouse model. In conclusion, our findings demonstrate that NPR1 deficiency increases vascular endothelial cell adhesion by stimulating ITGB4 expression, which may contribute to the development of atherosclerosis.

Heparanase: A Novel Therapeutic Target for the Treatment of Atherosclerosis

Cardiovascular disease (CVD) is the leading cause of death and disability worldwide, and its management places a huge burden on healthcare systems through hospitalisation and treatment. Atherosclerosis is a chronic inflammatory disease of the arterial wall resulting in the formation of lipid-rich, fibrotic plaques under the subendothelium and is a key contributor to the development of CVD. As such, a detailed understanding of the mechanisms involved in the development of atherosclerosis is urgently required for more effective disease treatment and prevention strategies. Heparanase is the only mammalian enzyme known to cleave heparan sulfate of heparan sulfate proteoglycans, which is a key component of the extracellular matrix and basement membrane. By cleaving heparan sulfate, heparanase contributes to the regulation of numerous physiological and pathological processes such as wound healing, inflammation, tumour angiogenesis, and cell migration. Recent evidence suggests a multifactorial role for heparanase in atherosclerosis by promoting underlying inflammatory processes giving rise to plaque formation, as well as regulating lesion stability. This review provides an up-to-date overview of the role of heparanase in physiological and pathological processes with a focus on the emerging role of the enzyme in atherosclerosis.

Can Micro RNA-24 Affect the Cardiovascular Morbidity in Systemic Lupus Erythematosus by Targeting YKL-40?

Background

Systemic lupus erythematosus (SLE) is an autoimmune disease with inflammatory nature. One of the leading causes of death in SLE patients is cardiovascular (CVS) morbidity. MiRNA-24 is highly expressed in vascular endothelial cells (VECs). This dysregulated expression pattern is associated with dysfunction or even damage of VECs and leads to the occurrence of cardiovascular diseases. YKL- 40 is an inflammatory glycoprotein involved in the pathogenesis of endothelial dysfunction and thereby atherosclerosis. In this work, we aimed at illustrating the possible role of miR-24 and its target YKL-40 in the pathogenesis of the CVS morbidity associated with SLE.

Methods

This work was conducted on 40 SLE patients and 40 healthy controls. Quantitative real-time PCR (qPCR) was done to estimate the expression level of miRNA-24 in serum. In addition, we measured the serum level of YKL-40 using ELISA.

Results

miR-24-fold change was found to be down-regulated, whereas serum YKL- 40 was up-regulated among SLE patients with observed significant and negative correlation between the two parameters.

Conclusion

Our study provided an insight about the role of miR-24 and its target serum YKL-40 protein in the development of SLE-related inflammation and atherosclerosis.

Persicaria minor (Huds.) Opiz Prevents In Vitro Atherogenesis by Attenuating Tumor Necrosis Factor-α-Induced Monocyte Adhesion to Human Umbilical Vein Endothelial Cells

Persicaria minor (Huds.) Opiz is an herb with anti-inflammatory, antioxidant, and anti-atherosclerosis effects. Nevertheless, the mechanism underlying its anti-atherosclerosis effect is poorly comprehended. This in vitro study assessed the protective effects of standardized aqueous extract of P. minor leaves (PM) on tumor necrosis factor-α (TNF-α)-induced monocyte adhesion to human umbilical vein endothelial cells (HUVEC), which is one of the pivotal early steps in atherogenesis. The results showed that PM decreased the mRNA and protein expression of cellular adhesion molecules, vascular adhesion molecule-1 and intercellular adhesion molecule-1, resulting in reduced adhesion of monocytes to HUVEC. Additionally, PM inhibited nuclear factor kappaB (NF-κB) activation as indicated by reduced NF-κB p65 levels in TNF-α-induced HUVEC. Overall, PM could prevent in vitro atherogenesis by inhibiting NF-κB activation and adhesion of monocytes to HUVEC. The effects of PM are probably mediated by its bioactive compound, quercetin-3-O-glucuronide. The findings may provide a rationale for the in vivo anti-atherosclerosis effect of PM, and support its potential use in atherosclerosis.

Immune Function of Endothelial Cells: Evolutionary Aspects, Molecular Biology and Role in Atherogenesis

Atherosclerosis is one of the key problems of modern medicine, which is due to the high prevalence of atherosclerotic cardiovascular diseases and their significant share in the structure of morbidity and mortality in many countries. Atherogenesis is a complex chain of events that proceeds over many years in the vascular wall with the participation of various cells. Endothelial cells are key participants in vascular function. They demonstrate involvement in the regulation of vascular hemodynamics, metabolism, and innate immunity, which act as leading links in the pathogenesis of atherosclerosis. These endothelial functions have close connections and deep evolutionary roots, a better understanding of which will improve the prospects of early diagnosis and effective treatment.

Gynura procumbens (Lour.) Merr. extract attenuates monocyte adherence to endothelial cells through suppression of the NF-κB signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Gynura procumbens (Lour.) Merr. (GP) is a herbaceous plant that grows in Malaysia and other parts of Southeast Asia. The herb is consumed as a remedy for various inflammatory-associated diseases, such as cancer, rheumatism, hypertension, diabetes mellitus and hyperlipidemia. Scientific studies demonstrate that GP extract possesses cardioprotective and anti-inflammatory effects. Cardiovascular disease is mainly caused by atherosclerosis, and inflammation plays a major role in all phases of atherosclerosis. The early inflammatory events in atherogenesis are the activation of endothelial cells and the recruitment of monocytes.

AIM OF THE STUDY

This study aimed to evaluate the inhibitory effect of 80% ethanol extract of GP leaves (GPE) on the adherence of monocytes to the activated human endothelial cells and its underlying mechanism.

MATERIAL AND METHODS

Qualitative and quantitative analyses of the extract were carried out by using a validated HPLC and UHPLC-MS/MS methods. The MTT test was used to select the range of concentration of extract for this study. The effect of GPE on TNF-α-induced monocyte-endothelial interaction was determined by the in vitro adhesion assay. Expression of cell surface proteins (ICAM-1, VCAM-1) and phosphorylation of nuclear factor kappa B (NF-κB) were determined by western blot, while expression of a chemokine (MCP-1) was identified by an enzyme-linked immunosorbent assay.

RESULTS

HPLC and UHPLC-MS/MS analyses indicated that GPE contained chlorogenic acid, nicotiflorin and astragalin as the major compounds. GPE at 20, 40 and 60 μg/mL concentrations showed a significant reduction in monocyte adherence to endothelial cells and expression of ICAM-1 and MCP-1. However, only GPE at concentrations of 40 and 60 μg/mL was able to reduce VCAM-1 expression. Furthermore, GPE significantly inhibited IKKα/β, IκBα, NF-κB phosphorylation and NF-κB translocation.

CONCLUSION

In conclusion, GPE may inhibit monocyte adherence to the activated endothelial cells and expression of ICAM-1, VCAM-1 and MCP-1, which are important proteins for monocyte-endothelial interaction, by suppressing the NF-κB signaling pathway. The results of this study support the traditional use of GPE to counteract inflammation-associated diseases and suggest that GP can be a potential source for bioactive compounds for the development of anti-inflammatory agents to prevent atherosclerosis.

Effect of the Human Amniotic Membrane on the Umbilical Vein Endothelial Cells of Gestational Diabetic Mothers: New Insight on Inflammation and Angiogenesis

One of the most relevant diabetes complications is impaired wound healing, mainly characterized by reduced peripheral blood flow and diminished neovascularization together with increased inflammation and oxidative stress. Unfortunately, effective therapies are currently lacking. Recently, the amniotic membrane (AM) has shown promising results in wound management. Here, the potential role of AM on endothelial cells isolated from the umbilical cord vein of gestational diabetes-affected women (GD-HUVECs), has been investigated. Indeed, GD-HUVECs in vivo exposed to chronic hyperglycemia during pregnancy compared to control cells (C-HUVECs) have shown molecular modifications of cellular homeostasis ultimately impacting oxidative and nitro-oxidative stress, inflammatory phenotype, nitric oxide (NO) synthesis, and bioavailability, thus representing a useful model for studying the mechanisms potentially supporting the role of AM in chronic non-healing wounds. In this study, the anti-inflammatory properties of AM have been assessed using a monocyte–endothelium interaction assay in cells pre-stimulated with tumor necrosis factor-α (TNF-α) and through vascular adhesion molecule expression and membrane exposure, together with the AM impact on the nuclear factor kappa-light-chain-enhancer of activated B cell (NF-kB) pathway and NO bioavailability. Moreover, GD-HUVEC migration and tube formation ability were evaluated in the presence of AM. The results showed that AM significantly reduced TNF-α-stimulated monocyte–endothelium interaction and the membrane exposure of the endothelial vascular and intracellular adhesion molecules (VCAM-1 and ICAM-1, respectively) in both C- and GD-HUVECs. Strikingly, AM treatment significantly improved vessel formation in GD-HUVECs and cell migration in both C- and GD-HUVECs. These collective results suggest that AM positively affects various critical pathways in inflammation and angiogenesis, thus providing further validation for ongoing clinical trials in diabetic foot ulcers.

CircRNA-miRNA interactions in atherogenesis

Atherosclerosis is the major cause of coronary artery disease (CAD) which includes unstable angina, myocardial infarction, and heart failure. The onset of atherogenesis, a process of atherosclerotic lesion formation in the intima of arteries, is driven by lipid accumulation, a vicious cycle of reactive oxygen species (ROS)-induced oxidative stress and inflammatory reactions leading to endothelial cell (EC) dysfunction, vascular smooth muscle cell (VSMC) activation, and foam cell formation which further fuel plaque formation and destabilization. In recent years, there is a surge in the number of publications reporting the involvement of circular RNAs (circRNAs) in the pathogenesis of cardiovascular diseases, cancers, and metabolic syndromes. These studies have advanced our understanding on the biological functions of circRNAs. One of the most common mechanism of action of circRNAs reported is the sponging of microRNAs (miRNAs) by binding to the miRNAs response element (MRE), thereby indirectly increases the transcription of their target messenger RNAs (mRNAs). Individual networks of circRNA-miRNA-mRNA associated with atherogenesis have been extensively reported, however, there is a need to connect these findings for a complete overview. This review aims to provide an update on atherogenesis-related circRNAs and analyze the circRNA-miRNA-mRNA interactions in atherogenesis. The atherogenic mechanisms and clinical relevance of each atherogenesis-related circRNA were systematically discussed for better understanding of the knowledge gap in this area.

Association of Monocyte Count and Monocyte/Lymphocyte Ratio with the Risk of Cardiovascular Outcomes in Patients with CKD

Background

Emerging evidence suggests an association of higher monocyte count and monocyte/lymphocyte ratio (MLR) with the risk of cardiovascular disease (CVD) in individuals without chronic kidney disease (CKD); however, limited studies have examined if this association translates to the CKD population. This study examined whether monocyte count and MLR are associated with the risk of CVD, CVD death, and all-cause death in patients with nondialysis CKD who participated in the Chronic Renal Insufficiency Cohort observational study.

Methods

Baseline monocyte count and MLR were categorized into tertiles and also modeled continuously. Cox proportional hazards models were used to examine the association between monocyte count (primary predictor) and MLR (secondary predictor) at baseline and time to a composite of CVD events, including heart failure, myocardial infarction, ischemic stroke, and peripheral artery disease (primary outcome). Secondary outcomes were time to CVD death and all-cause death.

Results

The median follow-up time was 9 years for CVD events and 11.7 years for death. In the fully adjusted model, participants with a higher monocyte count and MLR had a greater risk of CVD events (hazard ratio [HR] per doubling of monocyte count=1.2 [95% CI, 1.1 to 1.31]; HR per doubling of MLR=1.26 [95% CI, 1.16 to 1.36]), CVD death (HR=1.18 [95% CI, 0.99 to 1.41]; HR=1.27 [95% CI, 1.1 to 1.48]), and all-cause death (HR=1.17 [95% CI, 1.06 to 1.3]; HR=1.18 [95% CI, 1.09 to 1.29]).

Conclusions

These results suggest that monocyte count and MLR may have the potential to be cost-effective, clinically available indicators of CVD risk in the CKD population.

Vascular Protective Effect and Its Possible Mechanism of Action on Selected Active Phytocompounds: A Review

Vascular endothelial dysfunction is characterized by an imbalance of vasodilation and vasoconstriction, deficiency of nitric oxide (NO) bioavailability and elevated reactive oxygen species (ROS), and proinflammatory factors. This dysfunction is a key to the early pathological development of major cardiovascular diseases including hypertension, atherosclerosis, and diabetes. Therefore, modulation of the vascular endothelium is considered an important therapeutic strategy to maintain the health of the cardiovascular system. Epidemiological studies have shown that regular consumption of medicinal plants, fruits, and vegetables promotes vascular health, lowering the risk of cardiovascular diseases. This is mainly attributed to the phytochemical compounds contained in these resources. Various databases, including Google Scholar, MEDLINE, PubMed, and the Directory of Open Access Journals, were searched to identify studies demonstrating the vascular protective effects of phytochemical compounds. The literature had revealed abundant data on phytochemical compounds protecting and improving the vascular system. Of the numerous compounds reported, curcumin, resveratrol, cyanidin-3-glucoside, berberine, epigallocatechin-3-gallate, and quercetin are discussed in this review to provide recent information on their vascular protective mechanisms in vivo and in vitro. Phytochemical compounds are promising therapeutic agents for vascular dysfunction due to their antioxidative mechanisms. However, future human studies will be necessary to confirm the clinical effects of these vascular protective mechanisms.

Thymoquinone (TQ) Inhibits Inflammation and Migration of THP-1 Macrophages: Mechanistic Insights into the Prevention of Atherosclerosis Using In-Vitro and In-Silico Analysis

Atherosclerosis is an inflammatory disease mediated by interferon (IFN-γ) in concert with cell adhesion molecules and chemokines. Thymoquinone (TQ), a flavonoid derived from Nigella sativa, is reported to have anti-inflammatory, antioxidant, and cardiovascular protective properties. We evaluated the effects of TQ on the key pathogenic stages of atherosclerosis, including cell viability, inflammatory gene expression, cell migration, and cholesterol efflux, on human THP-1 macrophages in-vitro. Moreover, in-silico analysis was performed to predict the molecular targets and signaling mechanisms. We demonstrated that TQ treatment had no effect on cell viability and decreased the expression of monocyte chemoattractant protein (MCP-1) and intercellular adhesion molecule (ICAM-1) in response to IFN-γ. In addition, we have also demonstrated that the THP-1 cell migration was inhibited by TQ in the absence or presence of MCP-1. Thymoquinone had no effect on cholesterol efflux from monocytes. In-silico analysis also identified several putative targets for TQ that are associated with inflammatory diseases and associated signaling pathways. Collectively, these results suggest that TQ has anti-inflammatory effects and may be a potential nutraceutical candidate for the prevention and treatment of atherosclerosis.

Synthetic Vascular Graft with Spatially Distinct Architecture for Rapid Biomimetic Cell Organisation in a Perfusion Bioreactor

Access to lab-grown fully functional blood vessels would provide an invaluable resource to vascular medicine. The complex architecture and cellular makeup of native vessels, however, makes this extremely challenging to reproduce in vitro. Bioreactor systems have helped advanced research in this area by replicating many of the physiological conditions necessary for full-scale tissue growth outside of the body. A key element underpinning these technologies are 3D vascular graft templates which serve as temporary scaffolds to direct cell growth into similar cellular architectures observed in native vessels. Grafts further engineered with appropriate physical cues to accommodate the multiple cell types that reside within native vessels may help improve the production efficiency and physiological accuracy of bioreactor-grown vessel substitutes. Here, we engineered two distinct scaffold architectures into an electrospun vascular graft aiming to encourage the spatial organisation of human vascular endothelial cells (hCAECs) in a continuous luminal monolayer, co-cultured with human fibroblasts (hFBs) populating the graft wall. Using an electrospun composite of polycaprolactone (PCL) and gelatin, we evaluated physical parameters including fibre thickness, fibre alignment, and porosity, that best mimicked the spatial composition and growth of hCAECs and hFBs in native vessels. Upon identifying the optimal scaffold architectures for each cell type, we constructed a custom-designed mandrel that combined these distinct architectures into a single vascular graft during a single electrospinning processing run. When connected to a perfusion bioreactor system, the dual architecture graft spatially oriented hCAECs and hFBs into the graft wall and lumen, respectively, directly from circulation. This biomimetic cell organisation was consistent with positive graft remodelling with significant collagen deposition in the graft wall. These findings demonstrate the influence of architectural cues to direct cell growth within vascular graft templates and the future potential of these approaches to more accurately and efficiency produce blood vessel substitutes in bioreactor systems.

miR-27a inhibits molecular adhesion between monocytes and human umbilical vein endothelial cells; systemic approach

OBJECTIVE

The endothelial cells overexpress the adhesion molecules in the leukocyte diapedesis pathway, developing vessel subendothelial molecular events. In this study, miR-194 and miR-27a were predicted and investigated on the expression of adhesion molecules in HUVEC cells. The SELE, SELP, and JAM-B adhesion molecules involved in the leukocyte tethering were predicted on the GO-enriched gene network. Following transfection of PEI-miRNA particles into HUVEC cells, the SELE, SELP, and JAM-B gene expression levels were evaluated by real-time qPCR. Furthermore, the monocyte-endothelial adhesion was performed using adhesion assay kit.

RESULTS

In agreement with the prediction results, the cellular data showed that miR-27a and miR-194 decrease significantly the SELP and JAM-B expression levels in HUVECs (P < 0.05). Moreover, both the miRNAs suppressed the monocyte adhesion to endothelial cells. Since the miR-27a inhibited significantly the monocyte-endothelial adhesion (P = 0.0001) through the suppression of SELP and JAM-B thus it might relate to the leukocyte diapedesis pathway.

Biomarkers of Endothelial Activation in Black South African HIV-Positive Subjects are Associated with Both High Viral Load and Low CD4 Counts

The prevalence of cardiovascular death in the HIV-infected population is higher than in uninfected individuals. Growing evidence suggests that HIV infection itself is directly linked to endothelial activation and dysfunction. Therefore, the aim of this study was to investigate whether endothelial activation is present in African subjects with HIV infection and identify its possible determinants. Eighty HIV-infected treatment-naive cases, categorized into two groups based on CD4 count (38 subjects with CD4 count ≤350 cells/mm³ and 42 subjects with CD4 count >350 cells/mm³), were compared with 60 HIV-uninfected controls. A small subgroup of the HIV-infected participants (n = 13) were followed up for 18 months following initiation of antiretroviral therapy (ART). Anthropometric data, fasting lipid and glucose levels, viral load, and CD4 counts were measured as were serum levels of intercellular adhesion molecule-1 (ICAM-1), endothelial leukocyte adhesion molecule-1, vascular cell adhesion molecule-1 (VCAM-1), monocyte chemoattractant protein-1, von Willebrand factor (vWF), tumor necrosis factor alpha (TNF-α), interleukin-6 (IL-6), and interleukin-8 (IL-8). The HIV-infected low CD4 group had higher levels of ICAM-1 (p < .05), VCAM-1 (p < .0005), TNF-α (p < .005), and vWF (p < .005), compared with the controls. In the HIV-infected cohort, VCAM-1 levels were negatively associated with CD4 counts (β = -0.474; p < .0005), whereas vWF levels were positively associated with viral load (β = 0.344; p < .01). Levels of ICAM-1 and VCAM-1 were reduced by ART (p < .05 vs. baseline for both), however, levels of IL-6, IL-8, and TNF-α increased (p < .005 vs. baseline for all). Endothelial activation and inflammation are evident in African ART-naive HIV-infected patients; the former is attenuated, and the latter is increased after 18 months of ART. In HIV-infected subjects, both immunological dysregulation and viral load are associated with biomarkers of endothelial activation.

Four weeks of spice consumption lowers plasma proinflammatory cytokines and alters the function of monocytes in adults at risk of cardiometabolic disease: secondary outcome analysis in a 3-period, randomized, crossover, controlled feeding trial

BACKGROUND

Numerous studies demonstrate acute anti-inflammatory properties of individual spices, but none have examined the effect of longer-term consumption of a spice blend incorporated in a meal.

OBJECTIVES

We investigated the effect of longer-term spice consumption on inflammatory cytokines and monocyte subsets [classical (CM), intermediate (IM), nonclassical (NCM)] in adults at risk of cardiometabolic disease.

METHODS

A 3-period, randomized, crossover, controlled feeding trial was conducted. Participants (n = 71 recruited; n = 63 completed) randomly consumed diets differing in terms of the quantity of spices: 0.547 g (low-dose spice diet; LSD), 3.285 g (medium-dose spice diet; MSD), or 6.571 g (high-dose spice diet; HSD) · d-1 · 2100 kcal-1, for 4 wk with a ≥2-wk washout between diets. At baseline and after each diet period, proinflammatory cytokines (IL-1β, IL-6, IL-8, monocyte chemoattractant protein-1, and TNF-α) in plasma and LPS-stimulated peripheral blood mononuclear cell culture supernatants, and the phenotype and function of monocyte subsets, were measured in fasted participants. Postprandial proinflammatory cytokines also were quantified at baseline by consumption of a low-spice-dose test meal, and after each diet period by consumption of a test meal containing a spice dose corresponding to daily spice consumption during the preceding 4-wk diet period.

RESULTS

Fasting plasma IL-6 was reduced (mean ± SEM: -118.26 ± 50.63 fg/mL; P < 0.05) after MSD compared with baseline. Postprandial plasma IL-1β, IL-8, and TNF-α were lower (mean ± SEM : -9.47 ± 2.70 fg/mL, -0.20 ± 0.05 pg/mL, and -33.28 ± 12.35 fg/mL, respectively) after MSD compared with LSD (main diet effect; P < 0.05). CM adherence was reduced (mean ± SEM: -0.86 ± 0.34; P = 0.034) after HSD compared with LSD. IM migration was reduced after MSD and HSD compared with LSD (mean ± SEM: -0.39 ± 0.09 and -0.56 ± 0.14, respectively; P < 0.05).

CONCLUSIONS

Four weeks of MSD consumption reduced fasting plasma IL-6 and postprandial plasma IL-1β, IL-8, and TNF-α as well as altering monocyte function.This trial was registered at clinicaltrials.gov as NCT03064932.

Effect of Proteasome Inhibitor on Vascular Cell Adhesion Molecule-1 (VCAM-1) and Intercellular Adhesion Molecule-1 (ICAM-1) Expressions in Rat Model of Atherosclerosis

BACKGROUND

The effect of proteasome inhibitors on atherosclerosis is known to vary depending on the atherosclerosis stage. Previous studies have shown that the highest proteasome expression in atherosclerotic lesions is at the progression stage. Adhesion molecules play a role in the progression stage of atherosclerosis, but no studies have analyzed the effect of proteasome inhibitors on the expression of adhesion molecules at this stage.

METHODS

This experimental study aimed to analyze the effect of a proteasome inhibitor, namely bortezomib, on the vascular cell adhesion molecule-1 (VCAM-1) and intercellular adhesion molecule1 (ICAM-1) expressions in blood vessels of rat model of atherosclerosis at the progression stage. This study used 18 male Wistar rats divided into three groups, i.e. group I that is the control group given standard feed, group II induced by atherosclerosis, and group III induced by atherosclerosis and given bortezomib. Atherosclerosis induction was performed using vitamin D3 (700,000 IU/kg) orally by gastric intubation on the 1st day and atherogenic feed given for four days. Bortezomib 50 µg/kgBW/day was administered intra-peritoneally. The expression of VCAM-1 and ICAM-1 molecules was measured using immunohistochemistry and analyzed quantitatively using Adobe Photoshop software.

RESULTS

The statistical test showed differences in VCAM-1 expression between atherosclerosis + Bortezomib group and atherosclerosis group, but there were no differences in the expression of ICAM-1 and atherosclerotic lesions between the groups.

CONCLUSION

Administration of bortezomib 50μg/kg for four days in progressive atherosclerosis model rats can inhibit VCAM-1 expression, although it does not affect ICAM-1 expression and cannot inhibit atherosclerotic lesion formation.

Modular 3D In Vitro Artery-Mimicking Multichannel System for Recapitulating Vascular Stenosis and Inflammation

Inflammation and the immune response in atherosclerosis are complex processes involving local hemodynamics, the interaction of dysfunctional cells, and various pathological environments. Here, a modular multichannel system that mimics the human artery to demonstrate stenosis and inflammation and to study physical and chemical effects on biomimetic artery models is presented. Smooth muscle cells and endothelial cells were cocultured in the wrinkled surface in vivo-like circular channels to recapitulate the artery. An artery-mimicking multichannel module comprised four channels for the fabrication of coculture models and assigned various conditions for analysis to each model simultaneously. The manipulation became reproducible and stable through modularization, and each module could be replaced according to analytical purposes. A chamber module for culture was replaced with a microfluidic concentration gradient generator (CGG) module to achieve the cellular state of inflamed lesions by providing tumor necrosis factor (TNF)-α, in addition to the stenosis structure by tuning the channel geometry. Different TNF-α doses were administered in each channel by the CGG module to create functional inflammation models under various conditions. Through the tunable channel geometry and the microfluidic interfacing, this system has the potential to be used for further comprehensive research on vascular diseases such as atherosclerosis and thrombosis.

Ataxin-10 Inhibits TNF-α-Induced Endothelial Inflammation via Suppressing Interferon Regulatory Factor-1

Endothelial inflammation is a crucial event in the initiation of atherosclerosis. Here, we identify Ataxin-10 protein as a novel negative modulator of endothelial activation by suppressing IRF-1 transcription activity. The protein level of Ataxin-10 is relatively higher in human vascular endothelial cells, which can be significantly suppressed by TNF-α in both HUVECs and HLMECs. Overexpression of Ataxin-10 markedly inhibited the mRNA expressions of VCAM-1 and several cytokines including MCP-1, CXCL-1, CCL-5, and TNF-α; thus, it can also suppress monocyte adhesion to endothelial cells. Accordingly, Ataxin-10 silencing promoted endothelial inflammation. However, Ataxin-10 did not affect the MAPK/NF-κB signaling pathway stimulated by TNF-α in HUVECs. Using the yeast two-hybrid assay, we found that Ataxin-10 can directly bind to interferon regulatory factor-1 (IRF-1). Upon TNF-α stimulation, Ataxin-10 promoted the cytoplasmic localization of IRF-1, which inhibited the transcription of VCAM-1. Moreover, knockdown of IRF-1 can eliminate the effect of Ataxin-10 on the expression of VCAM-1 in HUVECs induced by TNF-α. Taken together, these results indicate that Ataxin-10 inhibits endothelial cell activation and may serve as a promising therapeutic target for some vascular inflammatory-related diseases such as atherosclerosis.

Ethanol extract of Gynura bicolour reduces atherosclerosis risk by enhancing antioxidant capacity and reducing adhesion molecule levels

CONTEXT

Gynura bicolour (Roxb. and Willd.) DC (Asteraceae) leaf is a common vegetable. Ethanol extracts of fresh G. bicolour leaves (GBEE) have several physiological effects, but studies on atherosclerosis are limited.

OBJECTIVE

We investigated the oxidant scavenging ability and vascular adhesion molecule expression of these extracts.

MATERIALS AND METHODS

The antioxidant effects of 0.05-0.4 mg/mL GBEE were analyzed in vitro. Intracellular antioxidant capacity and adhesion molecule levels were detected in EA.hy926 cells pre-treated with 10-100 μg/mL GBEE for 8 h, then TNF-α for 3 h. The antioxidant capacity of red blood cells and the adhesion molecule levels in the thoracic aorta were detected in high-fat diet (HFD)-fed Sprague-Dawley rats treated with GBEE for 12 weeks.

RESULTS

The in vitro EC₅₀ values of GBEE based on its DPPH radical-scavenging ability, reducing power, and ferrous ion-chelating ability were 0.20, 3.21 and 0.49 mg/mL, respectively. In TNF-α-treated EA.hy926 cells, the thiobarbituric acid-reactive substance levels were decreased after 10, 50, or 100 μg/mL GBEE treatments (IC₅₀: 19.1 mg/mL). When HFD-fed rats were co-treated with GBEE, the GBEE-H group exhibited 25% higher glutathione levels than the HFD group (p < 0.05). E-selectin, intercellular adhesion molecule-1, and vascular cell adhesion protein-1 levels were decreased in TNF-α-treated EA.hy926 cells after GBEE treatment (by approximately 11-73%; p < 0.05), and the above three adhesion molecules levels were decreased in HFD-fed rats with combined GBEE treatment (by approximately 30-77%; p < 0.05).

CONCLUSIONS

GBEE can protect the vascular endothelium by reducing adhesion molecule expression and regulating antioxidants. It may have the potential to prevent atherosclerosis.

Intermittent Fasting Inhibits High-Fat Diet-Induced Atherosclerosis by Ameliorating Hypercholesterolemia and Reducing Monocyte Chemoattraction

Atherosclerosis is a major pathology for cardiovascular diseases (CVDs). Clinically, the intermittent fasting (IF) has been observed to reduce the risk of CVDs. However, the effect of IF on the development of atherosclerosis has not been fully elucidated. Herein, we determined the protection of IF against high-fat diet–induced atherosclerosis in pro-atherogenic low-density lipoprotein receptor deficient (LDLR^-/-) mice and the potentially involved mechanisms. The LDLR^-/- mice were scheduled intermittent fasting cycles of 3-day HFD feeding ad libitum and 1 day fasting, while the mice in the control group were continuously fed HFD. The treatment was lasted for 7 weeks (∼12 cycles) or 14 weeks (∼24 cycles). Associated with the reduced total HFD intake, IF substantially reduced lesions in the en face aorta and aortic root sinus. It also increased plaque stability by increasing the smooth muscle cell (SMC)/collagen content and fibrotic cap thickness while reducing macrophage accumulation and necrotic core areas. Mechanistically, IF reduced serum total and LDL cholesterol levels by inhibiting cholesterol synthesis in the liver. Meanwhile, HFD-induced hepatic lipid accumulation was attenuated by IF. Interestingly, circulating Ly6C^high monocytes but not T cells and serum c-c motif chemokine ligand 2 levels were significantly reduced by IF. Functionally, adhesion of monocytes to the aortic endothelium was decreased by IF via inhibiting VCAM-1 and ICAM-1 expression. Taken together, our study indicates that IF reduces atherosclerosis in LDLR^-/- mice by reducing monocyte chemoattraction/adhesion and ameliorating hypercholesterolemia and suggests its potential application for atherosclerosis treatment.

Molecular Interactions Between Vascular Smooth Muscle Cells and Macrophages in Atherosclerosis

Atherosclerosis is the largest contributor toward life-threatening cardiovascular events. Cellular activity and cholesterol accumulation lead to vascular remodeling and the formation of fatty plaques. Complications arise from blood clots, forming at sites of plaque development, which may detach and result in thrombotic occlusions. Vascular smooth muscle cells and macrophages play dominant roles in atherosclerosis. A firm understanding of how these cells influence and modulate each other is pivotal for a better understanding of the disease and the development of novel therapeutics. Recent studies have investigated molecular interactions between both cell types and their impact on disease progression. Here we aim to review the current knowledge. Intercellular communications through soluble factors, physical contact, and extracellular vesicles are discussed. We also present relevant background on scientific methods used to study the disease, the general pathophysiology and intracellular factors involved in phenotypic modulation of vascular smooth muscle cells. We conclude this review with a discussion of the current state, shortcomings and potential future directions of the field.

HIV Tat-Mediated Induction of Monocyte Transmigration Across the Blood-Brain Barrier: Role of Chemokine Receptor CXCR3

HIV trans-activator of transcription (Tat), one of the cytotoxic proteins secreted from HIV-infected cells, is also known to facilitate chemokine-mediated transmigration of monocytes into the brain leading, in turn, to neuroinflammation and thereby contributing to the development of HIV-associated neurocognitive disorders (HAND). The mechanism(s) underlying HIV Tat-mediated enhancement of monocyte transmigration, however, remain largely unknown. CXC chemokine receptor 3 (CXCR3) that is expressed by the peripheral monocytes is known to play a role in the monocyte influx and accumulation. In the present study, we demonstrate for the first time that exposure of human monocytes to HIV Tat protein resulted in upregulated expression of CXCR3 leading, in turn, to increased monocyte transmigration across the blood–brain barrier (BBB) both in the in vitro and in vivo model systems. This process involved activation of toll-like receptor 4 (TLR4), with downstream phosphorylation and activation of TANK-binding kinase 1 (TBK1), and subsequent phosphorylation and nuclear translocation of interferon regulatory factor 3 (IRF3), ultimately leading to enhanced expression of CXCR3 in human monocytes. These findings imply a novel molecular mechanism underlying HIV Tat-mediated increase of monocyte transmigration across the BBB, while also implicating a novel role of CXCR3-dependent monocyte transmigration in HIV Tat-mediated neuroinflammation.

Antiatherogenic Effects of Quercetin in the THP-1 Macrophage Model In Vitro, With Insights Into Its Signaling Mechanisms Using In Silico Analysis

Background: Atherosclerosis (AS), a major risk factor for stroke and brain tissue destruction, is an inflammatory disease of the blood vessels, and the underlying pathology is inflammation mediated by various chemokines and cytokines. Quercetin, a natural flavonol, is reported to have both anti-inflammatory and antioxidant properties. As such, in the present study, we evaluated the antiatherogenic effects of quercetin in a human THP-1 cell line in vitro and also the signaling mechanisms using in silico analysis.

Materials and Methods: THP-1 macrophages exposed to different concentrations of quercetin (5–100 μM for 24 h) were tested for cytotoxicity. Real-time gene expression assay for intercellular adhesion molecule-1 (ICAM-1) and monocyte chemoattractant protein-1 (MCP-1) was carried out following treatment with quercetin at 15 and 30 μM for 24 h either in the absence or presence of interferon (IFN-γ) for 3 h to induce inflammation. Monocyte migration and cholesterol efflux were also assessed.

Results: Quercetin did not exert any cytotoxic effects on THP-1 cells at the various concentrations tested. The gene expression assay showed a significant decrease in ICAM-1 (by 3.05 and 2.70) and MCP-1 (by 22.71 and 27.03), respectively. Quercetin at 15 µM decreased THP-1 monocyte migration by 33% compared to the MCP-1-treated cells. It also increased cholesterol efflux significantly by1.64-fold and 1.60-fold either alone or in combination with IFN-γ, respectively. Ingenuity Pathway Analysis of the molecular interactions of quercetin identified canonical pathways directly related to lipid uptake and cholesterol efflux. Furthermore, CD36, SR-A, and LXR-α also demonstrated significant increases by 72.16-, 149.10-, and 29.68-fold, respectively.

Conclusion: Our results from both in vitro and in silico studies identified that quercetin inhibited the THP-1 monocyte migration, MCP-1, and ICAM-1 and increased cholesterol efflux probably mediated via the LXR/RXR signaling pathway. Therefore, quercetin will help prevent cell infiltration in atherosclerotic plaques and reduce the risk of stroke or brain destruction.

Leucine-Rich α-2-Glycoprotein 1 Suppresses Endothelial Cell Activation Through ADAM10-Mediated Shedding of TNF-α Receptor

Elevated serum concentrations of leucine-rich α-2-glycoprotein (LRG1) have been reported in patients with inflammatory, autoimmune, and cardiovascular diseases. This study aims to investigate the role of LRG1 in endothelial activation. LRG1 in endothelial cells (ECs) of arteries and serum of patients with critical limb ischemia (CLI) was assessed by immunohistochemistry and ELISA, respectively. LRG1 expression in sheared and tumor necrosis factor-α (TNF-α)-treated ECs was analyzed. The mechanistic role of LRG1 in endothelial activation was studied in vitro. Plasma of 37-week-old Lrg1 ^-/- mice was used to investigate causality between LRG1 and tumor necrosis factor receptor 1 (TNFR1) shedding. LRG1 was highly expressed in ECs of stenotic but not normal arteries. LRG1 concentrations in serum of patients with CLI were elevated compared to healthy controls. LRG1 expression was shear dependent. It could be induced by TNF-α, and the induction of its expression was mediated by NF-κB activation. LRG1 inhibited TNF-α-induced activation of NF-κB signaling, expression of VCAM-1 and ICAM-1, and monocyte capture, firm adhesion, and transendothelial migration. Mechanistically, LRG1 exerted its function by causing the shedding of TNFR1 via the ALK5-SMAD2 pathway and the subsequent activation of ADAM10. Consistent with this mechanism, LRG1 and sTNFR1 concentrations were correlated in the serum of CLI patients. Causality between LRG1 and TNFR1 shedding was established by showing that Lrg1 ^-/- mice had lower plasma sTNFR1 concentrations than wild type mice. Our results demonstrate a novel role for LRG1 in endothelial activation and its potential therapeutic role in inflammatory diseases should be investigated further.

Anti-inflammatory potential of simvastatin loaded nanoliposomes in 2D and 3D foam cell models

Atherosclerosis is a multifactorial disease triggered and sustained by risk factors such as high cholesterol, high blood pressure and unhealthy lifestyle. Inflammation plays a pivotal role in atherosclerosis pathogenesis. In this study, we developed a simvastatin (STAT) loaded nanoliposomal formulation (LIPOSTAT) which can deliver the drug into atherosclerotic plaque, when administered intravenously. This formulation is easily prepared, stable, and biocompatible with minimal burst release for effective drug delivery. 2D and 3D in vitro models were examined towards anti-inflammatory effects of STAT, both free and in combination with liposomes. LIPOSTAT induced greater cholesterol efflux in the 2D foam cells and significantly reduced inflammation in both 2D and 3D models. LIPOSTAT alleviated inflammation by reducing the secretion of early and late phase pro-inflammatory cytokines, monocyte adherence marker, and lipid accumulation cytokines. Additionally, the 3D foam cell spheroid model is a convenient and practical approach in testing various anti-atherosclerotic drugs without the need for human tissue.

Erythrocytes: Central Actors in Multiple Scenes of Atherosclerosis

The development and progression of atherosclerosis (ATH) involves lipid accumulation, oxidative stress and both vascular and blood cell dysfunction. Erythrocytes, the main circulating cells in the body, exert determinant roles in the gas transport between tissues. Erythrocytes have long been considered as simple bystanders in cardiovascular diseases, including ATH. This review highlights recent knowledge concerning the role of erythrocytes being more than just passive gas carriers, as potent contributors to atherosclerotic plaque progression. Erythrocyte physiology and ATH pathology is first described. Then, a specific chapter delineates the numerous links between erythrocytes and atherogenesis. In particular, we discuss the impact of extravasated erythrocytes in plaque iron homeostasis with potential pathological consequences. Hyperglycaemia is recognised as a significant aggravating contributor to the development of ATH. Then, a special focus is made on glycoxidative modifications of erythrocytes and their role in ATH. This chapter includes recent data proposing glycoxidised erythrocytes as putative contributors to enhanced atherothrombosis in diabetic patients.

In vitro evaluation of the involvement of Nrf2 in maslinic acid-mediated anti-inflammatory effects in atheroma pathogenesis

AIMS

Maslinic acid (MA) is a naturally occurring pentacyclic triterpene known to exert cardioprotective effects. This study aims to investigate the involvement of nuclear factor erythroid 2-related factor 2 (Nrf2) for MA-mediated anti-inflammatory effects in atheroma pathogenesis in vitro, including evaluation of tumor necrosis factor-alpha (TNF-α)-induced monocyte recruitment, oxidized low-density lipoprotein (oxLDL)-induced scavenger receptors expression, and nuclear factor-kappa B (NF-ĸB) activity in human umbilical vein endothelial cells (HUVECS) and human acute monocytic leukemia cell line (THP-1) macrophages.

MATERIALS AND METHODS

An in vitro monocyte recruitment model utilizing THP-1 and HUVECs was developed to evaluate TNF-α-induced monocyte adhesion and trans-endothelial migration. To study the role of Nrf2 for MA-mediated anti-inflammatory effects, Nrf2 inhibitor ML385 was used as the pharmacological inhibitor. The expression of Nrf2, monocyte chemoattractant protein-1 (MCP-1), vascular cell adhesion molecule 1 (VCAM-1), cluster of differentiation 36 (CD36), and scavenger receptor type A (SR-A) in HUVECs and THP-1 macrophages were investigated using RT-qPCR and Western blotting. The NF-κB activity was determined using NF-κB (p65) Transcription Factor Assay Kit.

KEY FINDINGS

The results showed opposing effects of MA on Nrf2 expression in HUVECs and THP-1 macrophages. MA suppressed TNF-α-induced Nrf2 expression in HUVECs, but enhanced its expression in THP-1 macrophages. Combined effects of MA and ML385 suppressed MCP-1, VCAM-1, and SR-A expressions. Intriguingly, at the protein level, ML385 selectively inhibited SR-A but enhanced CD36 expression. Meanwhile, ML385 further enhanced MA-mediated inhibition of NF-κB activity in HUVECs. This effect, however, was not observed in THP-1 macrophages.

SIGNIFICANCE

MA attenuated foam cell formation by suppressing VCAM-1, MCP-1, and SR-A expression, as well as NF-κB activity, possibly through Nrf2 inhibition. The involvement of Nrf2 for MA-mediated anti-inflammatory effects however differs between HUVECs and macrophages. Future investigations are warranted for a detailed evaluation of the contributing roles of Nrf2 in foam cells formation.

Effects from the induction of heat shock proteins in a murine model due to progression of aortic atherosclerosis

Heat shock proteins (HSPs) are molecular chaperones that repair denatured proteins. The relationship between HSPs and various diseases has been extensively studied. However, the relationship between HSPs and atherosclerosis remains unclear. In this study, we induced the expression of HSPs and analyzed the effects on the development/progression of atherosclerosis in vivo. Remarkably, when HSPs were induced in apolipoprotein E deficient (ApoE^-/-) mice prior to the formation of atheromas, the progression of atherosclerosis was inhibited; the short-term induction of HSPs significantly decreased the mRNA expression of intercellular adhesion molecule 1 (ICAM-1) and vascular cell adhesion molecule 1 (VCAM-1) in the aorta. In contrast, the induction of HSPs after the formation of atheromas promoted the progression of atherosclerosis. In fact, the short-term induction of HSPs, after the formation of atheromas, significantly increased the mRNA expression of tumor necrosis factor-alpha, and interleukin 6 in the aorta. Of note, the induction of HSPs also promoted the formation of macrophage-derived foam cells. Overall, these results indicate that HSPs exerts different effects in the context of aortic atherosclerosis, depending on its degree of progression. Therefore, the induction and inhibition of HSPs should be considered for the prevention and treatment of atherosclerosis, respectively.

Skeletal muscle-specific forkhead box protein-O1 overexpression suppresses atherosclerosis progression in apolipoprotein E-knockout mice

Calorie restriction (CR) reportedly prevents atherosclerotic diseases. Furthermore, CR induces forkhead box protein-O1 (FOXO-1) expression in the skeletal muscle, altering the character of the skeletal muscle. We previously reported that the change in skeletal muscle character, induced by the overexpression of peroxisome proliferator-activated receptor γ coactivator-1α, suppresses atherosclerotic progression in an atherosclerotic apolipoprotein E-knockout (ApoE-KO) mouse model. Thus, we hypothesized that skeletal muscle alternation induced by FOXO-1 may also have an anti-atherosclerotic effect in ApoE-KO mice. In this study, we investigated whether skeletal muscle-specific FOXO-1 overexpression suppresses the progression of atherosclerosis in ApoE-KO mice. We generated ApoE-KO/FOXO-1 mice, in which an ApoE-KO mouse was crossbred with a mouse presenting skeletal muscle-specific FOXO-1 overexpression (FOXO-1Tg). The mice were sacrificed at 20 weeks of age, and atherosclerotic plaque area and protein expression in the plaque were measured. Additionally, we measured the tumor necrosis factor α (TNFα)- induced mRNA expression in human umbilical vein endothelial cells (HUVECs), using serum collected from the FOXO-1Tg mice. Accordingly, ApoE-KO/FOXO-1 mice showed a 65% reduced atherosclerotic plaque area when compared with the ApoE-KO mice, with concomitantly reduced vascular cell adhesion molecule-1 (VCAM-1) and macrophage infiltration. As compared to serum from wild-type mice, the serum collected from the FOXO-1Tg mice significantly suppressed the mRNA expression of VCAM-1, an atherosclerosis initiation factor, in TNFα-treated HUVECs. Therefore, these data suggest that skeletal muscle-specific FOXO-1 overexpression suppresses the progression of atherosclerosis in ApoE-KO mice. In part, the CR-induced anti-atherosclerotic effect could be attributed to FOXO-1 upregulation in the skeletal muscle.

Plasma from obese children increases monocyte-endothelial adhesion and affects intracellular insulin signaling in cultured endothelial cells: Potential role of mTORC1-S6K1

Childhood obesity is characterized by the loss of vascular insulin sensitivity along with altered oxidant-antioxidant state and chronic inflammation, which play a key role in the onset of endothelial dysfunction. We previously demonstrated a reduced insulin-stimulated Nitric Oxide (NO) bioavailability in Human Umbilical Vein Endothelial cells (HUVECs) cultured with plasma from obese pre-pubertal children (OB) compared to those cultured with plasma of normal-weight children (CTRL). However, mechanisms underlying endothelial dysfunction in childhood obesity remains poorly understood. Hence, the present study aimed to better investigate these mechanisms, also considering a potential involvement of mammalian Target Of Rapamycin Complex1 (mTORC1)-ribosomal protein S6 Kinase beta1 (S6K1) pathway. OB-children (N = 32, age: 9.2 ± 1.7; BMI z-score: 2.72 ± 0.31) had higher fasting insulin levels and increased HOMA-IR than CTRL-children (N = 32, age: 8.8 ± 1.2; BMI z-score: 0.33 ± 0.75). In vitro, HUVECs exposed to OB-plasma exhibited significant increase in Reactive Oxygen Species (ROS) levels, higher vascular and intercellular adhesion molecules exposure, together with increased monocytes-endothelial interaction. This was associated with unbalanced pro- and anti-atherogenic endothelial insulin stimulated signaling pathways, as measured by increased Mitogen Activated Protein Kinase (MAPK) and decreased Insulin Receptor Substrate-1 (IRS-1)/protein kinase B (Akt)/ endothelial NO Synthase (eNOS) phosphorylation levels, together with augmented S6K1 activation. Interestingly, inhibition of mTORC1-S6K1 pathway using rapamycin significantly restored the IRS-1/Akt/eNOS activation, suggesting a feedback regulation of IRS-1/Akt signal through S6K1. Overall, our in vitro data shed light on new mechanisms underlying the onset of endothelial dysfunction in childhood obesity.

Endothelial dysfunction in neuroprogressive disorders-causes and suggested treatments

BACKGROUND

Potential routes whereby systemic inflammation, oxidative stress and mitochondrial dysfunction may drive the development of endothelial dysfunction and atherosclerosis, even in an environment of low cholesterol, are examined.

MAIN TEXT

Key molecular players involved in the regulation of endothelial cell function are described, including PECAM-1, VE-cadherin, VEGFRs, SFK, Rho GEF TRIO, RAC-1, ITAM, SHP-2, MAPK/ERK, STAT-3, NF-κB, PI3K/AKT, eNOS, nitric oxide, miRNAs, KLF-4 and KLF-2. The key roles of platelet activation, xanthene oxidase and myeloperoxidase in the genesis of endothelial cell dysfunction and activation are detailed. The following roles of circulating reactive oxygen species (ROS), reactive nitrogen species and pro-inflammatory cytokines in the development of endothelial cell dysfunction are then described: paracrine signalling by circulating hydrogen peroxide, inhibition of eNOS and increased levels of mitochondrial ROS, including compromised mitochondrial dynamics, loss of calcium ion homeostasis and inactivation of SIRT-1-mediated signalling pathways. Next, loss of cellular redox homeostasis is considered, including further aspects of the roles of hydrogen peroxide signalling, the pathological consequences of elevated NF-κB, compromised S-nitrosylation and the development of hypernitrosylation and increased transcription of atherogenic miRNAs. These molecular aspects are then applied to neuroprogressive disorders by considering the following potential generators of endothelial dysfunction and activation in major depressive disorder, bipolar disorder and schizophrenia: NF-κB; platelet activation; atherogenic miRs; myeloperoxidase; xanthene oxidase and uric acid; and inflammation, oxidative stress, nitrosative stress and mitochondrial dysfunction.

CONCLUSIONS

Finally, on the basis of the above molecular mechanisms, details are given of potential treatment options for mitigating endothelial cell dysfunction and activation in neuroprogressive disorders.