Implications of early structural-functional changes in the endothelium for vascular disease

A Co-Culture System for Studying Cellular Interactions in Vascular Disease

Cardiovascular diseases (CVDs) are leading causes of morbidity and mortality globally, characterized by complications such as heart failure, atherosclerosis, and coronary artery disease. The vascular endothelium, forming the inner lining of blood vessels, plays a pivotal role in maintaining vascular homeostasis. The dysfunction of endothelial cells contributes significantly to the progression of CVDs, particularly through impaired cellular communication and paracrine signaling with other cell types, such as smooth muscle cells and macrophages. In recent years, co-culture systems have emerged as advanced in vitro models for investigating these interactions and mimicking the pathological environment of CVDs. This review provides an in-depth analysis of co-culture models that explore endothelial cell dysfunction and the role of cellular interactions in the development of vascular diseases. It summarizes recent advancements in multicellular co-culture models, their physiological and therapeutic relevance, and the insights they provide into the molecular mechanisms underlying CVDs. Additionally, we evaluate the advantages and limitations of these models, offering perspectives on how they can be utilized for the development of novel therapeutic strategies and drug testing in cardiovascular research.

Vascular Impairment, Muscle Atrophy, and Cognitive Decline: Critical Age-Related Conditions

The triad of vascular impairment, muscle atrophy, and cognitive decline represents critical age-related conditions that significantly impact health. Vascular impairment disrupts blood flow, precipitating the muscle mass reduction seen in sarcopenia and the decline in neuronal function characteristic of neurodegeneration. Our limited understanding of the intricate relationships within this triad hinders accurate diagnosis and effective treatment strategies. This review analyzes the interrelated mechanisms that contribute to these conditions, with a specific focus on oxidative stress, chronic inflammation, and impaired nutrient delivery. The aim is to understand the common pathways involved and to suggest comprehensive therapeutic approaches. Vascular dysfunctions hinder the circulation of blood and the transportation of nutrients, resulting in sarcopenia characterized by muscle atrophy and weakness. Vascular dysfunction and sarcopenia have a negative impact on physical function and quality of life. Neurodegenerative diseases exhibit comparable pathophysiological mechanisms that affect cognitive and motor functions. Preventive and therapeutic approaches encompass lifestyle adjustments, addressing oxidative stress, inflammation, and integrated therapies that focus on improving vascular and muscular well-being. Better understanding of these links can refine therapeutic strategies and yield better patient outcomes. This study emphasizes the complex interplay between vascular dysfunction, muscle degeneration, and cognitive decline, highlighting the necessity for multidisciplinary treatment approaches. Advances in this domain promise improved diagnostic accuracy, more effective therapeutic options, and enhanced preventive measures, all contributing to a higher quality of life for the elderly population.

Sex-specific association between monocyte to high-density lipoprotein cholesterol and extensive abdominal aortic calcification in humans

Recent studies have identified monocyte-to-high-density lipoprotein cholesterol ratio (MHR) as a simple marker of atherosclerosis. Abdominal aortic calcification (AAC) is a direct result of vascular atherosclerosis. Our study aims to investigate the association between MHR and the prevalent extensive AAC and assess the value of MHR for identifying prevalent extensive AAC. 2857 subjects (28.07%) from the cross-sectional National Health and Nutrition Examination Survey 2013-2014 were included in our study. AAC was detected through dual-energy x-ray absorptiometry and quantified by Kauppila score. Extensive AAC was identified in 153 (10.44% of 1465) females and 146 (10.49% of 1392) males. With the full adjustment, each SD increase of MHR resulted in an 87.3% additional risk for extensive AAC in females. When dividing into quartiles, the top quartile had a 3.472 times risk of prevalent extensive AAC than the bottom quartile. However, no significant association was observed in males. Furthermore, smooth curve fitting implicated that the significant association was linear in the whole range of MHR among females. Additionally, ROC demonstrated an improvement in the identification of extensive AAC only among females when introducing MHR into established risk factors of atherosclerosis (0.808 vs. 0.864, p < 0.001). Finally, category-free net reclassification index and integrated discrimination index also supported the improvement by MHR in females. Our study revealed a linear association between MHR and prevalent extensive AAC in females. Moreover, our results implicated the potential value of MHR to refine the identification of prevalent extensive AAC in females.

Dynamic metabolism of endothelial triglycerides protects against atherosclerosis in mice

Blood vessels are continually exposed to circulating lipids, and elevation of ApoB-containing lipoproteins causes atherosclerosis. Lipoprotein metabolism is highly regulated by lipolysis, largely at the level of the capillary endothelium lining metabolically active tissues. How large blood vessels, the site of atherosclerotic vascular disease, regulate the flux of fatty acids (FAs) into triglyceride-rich (TG-rich) lipid droplets (LDs) is not known. In this study, we showed that deletion of the enzyme adipose TG lipase (ATGL) in the endothelium led to neutral lipid accumulation in vessels and impaired endothelial-dependent vascular tone and nitric oxide synthesis to promote endothelial dysfunction. Mechanistically, the loss of ATGL led to endoplasmic reticulum stress-induced inflammation in the endothelium. Consistent with this mechanism, deletion of endothelial ATGL markedly increased lesion size in a model of atherosclerosis. Together, these data demonstrate that the dynamics of FA flux through LD affects endothelial cell homeostasis and consequently large vessel function during normal physiology and in a chronic disease state.

Endothelial Dysfunction in Obesity and Therapeutic Targets

Parallel to the increasing prevalence of obesity in the world, the mortality from cardiovascular disease has also increased. Low-grade chronic inflammation in obesity disrupts vascular homeostasis, and the dysregulation of adipocyte-derived endocrine and paracrine effects contributes to endothelial dysfunction. Besides the adipose tissue inflammation, decreased nitric oxide (NO)-bioavailability, insulin resistance (IR), and oxidized low-density lipoproteins (oxLDLs) are the main factors contributing to endothelial dysfunction in obesity and the development of cardiorenal metabolic syndrome. While normal healthy perivascular adipose tissue (PVAT) ensures the dilation of blood vessels, obesity-associated PVAT leads to a change in the profile of the released adipo-cytokines, resulting in a decreased vasorelaxing effect. Higher stiffness parameter β, increased oxidative stress, upregulation of pro-inflammatory cytokines, and nicotinamide adenine dinucleotide phosphate (NADP) oxidase in PVAT turn the macrophages into pro-atherogenic phenotypes by oxLDL-induced adipocyte-derived exosome-macrophage crosstalk and contribute to the endothelial dysfunction. In clinical practice, carotid ultrasound, higher leptin levels correlate with irisin over-secretion by human visceral and subcutaneous adipose tissues, and remnant cholesterol (RC) levels predict atherosclerotic disease in obesity. As a novel therapeutic strategy for cardiovascular protection, liraglutide improves vascular dysfunction by modulating a cyclic adenosine monophosphate (cAMP)-independent protein kinase A (PKA)-AMP-activated protein kinase (AMPK) pathway in PVAT in obese individuals. Because the renin-angiotensin-aldosterone system (RAAS) activity, hyperinsulinemia, and the resultant IR play key roles in the progression of cardiovascular disease in obesity, RAAS-targeted therapies contribute to improving endothelial dysfunction. By contrast, arginase reciprocally inhibits NO formation and promotes oxidative stress. Thus, targeting arginase activity as a key mediator in endothelial dysfunction has therapeutic potential in obesity-related vascular comorbidities. Obesity-related endothelial dysfunction plays a pivotal role in the progression of type 2 diabetes (T2D). The peroxisome proliferator-activated receptor gamma (PPARγ) agonist, rosiglitazone (thiazolidinedione), is a popular drug for treating diabetes; however, it leads to increased cardiovascular risk. Selective sodium-glucose co-transporter-2 (SGLT-2) inhibitor empagliflozin (EMPA) significantly improves endothelial dysfunction and mortality occurring through redox-dependent mechanisms. Although endothelial dysfunction and oxidative stress are alleviated by either metformin or EMPA, currently used drugs to treat obesity-related diabetes neither possess the same anti-inflammatory potential nor simultaneously target endothelial cell dysfunction and obesity equally. While therapeutic interventions with glucagon-like peptide-1 (GLP-1) receptor agonist liraglutide or bariatric surgery reverse regenerative cell exhaustion, support vascular repair mechanisms, and improve cardiometabolic risk in individuals with T2D and obesity, the GLP-1 analog exendin-4 attenuates endothelial endoplasmic reticulum stress.

High-fat diet causes endothelial dysfunction in the mouse ophthalmic artery

Obesity is a significant health concern that leads to impaired vascular function and subsequent abnormalities in various organs. The impact of obesity on ocular blood vessels, however, remains largely unclear. In this study, we examined the hypothesis that obesity induced by high-fat diet produces vascular endothelial dysfunction in the ophthalmic artery. Mice were subjected to a high-fat diet for 20 weeks, while age-matched controls were maintained on a standard diet. Reactivity of isolated ophthalmic artery segments was assessed in vitro. Reactive oxygen species (ROS) were quantified in cryosections by dihydroethidium (DHE) staining. Redox gene expression was determined in ophthalmic artery explants by real-time PCR. Furthermore, the expression of nicotinamide adenine dinucleotide phosphate oxidase 2 (NOX2), the receptor for advanced glycation end products (RAGE), and of the lectin-like oxidized low-density-lipoprotein receptor-1 (LOX-1) was determined in cryosections using immunofluorescence microscopy. Ophthalmic artery segments from mice on a high-fat diet exhibited impaired vasodilation responses to the endothelium-dependent vasodilator acetylcholine, while endothelium-independent responses to nitroprusside remained preserved. DHE staining intensity in the vascular wall was notably stronger in mice on a high-fat diet. Messenger RNA expression for NOX2 was elevated in the ophthalmic artery of mice subjected to high fat diet. Likewise, immunostainings revealed increased expression of NOX2 and of RAGE, but not of LOX-1. These findings suggest that a high-fat diet triggers endothelial dysfunction by inducing oxidative stress in the ophthalmic artery via involvement of RAGE and NOX2.

Studies on the Effects of Hypercholesterolemia on Mouse Ophthalmic Artery Reactivity

Atherogenic lipoproteins may impair vascular reactivity, leading to tissue damage in various organs, including the eye. This study aimed to investigate whether ophthalmic artery reactivity is affected in mice lacking the apolipoprotein E gene (ApoE-/-), a model for hypercholesterolemia and atherosclerosis. Twelve-month-old male ApoE-/- mice and age-matched wild-type controls were used to assess vascular reactivity using videomicroscopy. Moreover, the vascular mechanics, lipid content, levels of reactive oxygen species (ROS), and expression of pro-oxidant redox enzymes and the lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1) were determined in vascular tissue. Unlike the aorta, the ophthalmic artery of ApoE-/- mice developed no signs of endothelial dysfunction and no signs of excessive lipid deposition. Remarkably, the levels of ROS, nicotinamide adenine dinucleotide phosphate oxidase 1 (NOX1), NOX2, NOX4, and LOX-1 were increased in the aorta but not in the ophthalmic artery of ApoE-/- mice. Our findings suggest that ApoE-/- mice develop endothelial dysfunction in the aorta by increased oxidative stress via the involvement of LOX-1, NOX1, and NOX2, whereas NOX4 may participate in media remodeling. In contrast, the ophthalmic artery appears to be resistant to chronic apolipoprotein E deficiency. A lack of LOX-1 expression/overexpression in response to increased oxidized low-density lipoprotein levels may be a possible mechanism of action.

Ultrastructural features mirror metabolic derangement in human endothelial cells exposed to high glucose

High glucose-induced endothelial dysfunction is the early event that initiates diabetes-induced vascular disease. Here we employed Cryo Soft X-ray Tomography to obtain three-dimensional maps of high D-glucose-treated endothelial cells and their controls at nanometric spatial resolution. We then correlated ultrastructural differences with metabolic rewiring. While the total mitochondrial mass does not change, high D-glucose promotes mitochondrial fragmentation, as confirmed by the modulation of fission-fusion markers, and dysfunction, as demonstrated by the drop of membrane potential, the decreased oxygen consumption and the increased production of reactive oxygen species. The 3D ultrastructural analysis also indicates the accumulation of lipid droplets in cells cultured in high D-glucose. Indeed, because of the decrease of fatty acid β-oxidation induced by high D-glucose concentration, triglycerides are esterified into fatty acids and then stored into lipid droplets. We propose that the increase of lipid droplets represents an adaptive mechanism to cope with the overload of glucose and associated oxidative stress and metabolic dysregulation.

The Role of Txnip in Mediating Low-Magnesium-Driven Endothelial Dysfunction

Magnesium deficiency is associated with a greater risk of developing cardiovascular diseases since this cation is fundamental in regulating vascular function. This clinical evidence is sustained by in vitro studies showing that culturing endothelial cells in low concentrations of magnesium promotes the acquisition of a pro-oxidant and pro-inflammatory phenotype. Here, we show that the increase in reactive oxygen species in endothelial cells in low-magnesium-containing medium is due to the upregulation of the pro-oxidant protein thioredoxin interacting protein (TXNIP), with a consequent accumulation of lipid droplets and increase in endothelial permeability through the downregulation and relocalization of junctional proteins. Silencing TXNIP restores the endothelial barrier and lipid content. Because (i) mitochondria serve multiple roles in shaping cell function, health and survival and (ii) mitochondria are the main intracellular stores of magnesium, it is of note that no significant alterations were detected in their morphology and dynamics in our experimental model. We conclude that TXNIP upregulation contributes to low-magnesium-induced endothelial dysfunction in vitro.

Emerging Therapies for the Treatment of Atherosclerotic Cardiovascular Disease: From Bench to Bedside

Primarily a consequence of sedentary lifestyle, atherosclerosis has already reached pandemic proportions, and with every year the burden of it is only increasing. As low-density lipoprotein cholesterol (LDL-C) represents a crucial factor in atherosclerosis formation and progression, stringent lipid-lowering therapy could conceivably be the key to preventing the unfavorable outcomes that arise as a consequence of atherosclerosis. The use of statins in lipid-lowering is often burdened by adverse events or is insufficient to prevent cardiovascular events as a monotherapy. Therefore, in the present review, the authors aimed to discuss the underlying mechanisms of dyslipidemia and associated atherosclerotic cardiovascular disease (ASCVD) and preclinical and clinical trials of novel therapeutic approaches to its treatment, some of which are still in the early stages of development. Apart from novel therapies, a novel change in perspective is needed. Specifically, the critical objective in the future management of ASCVD is to embrace emerging evidence in the field of atherosclerosis, because clinicians are often burden by common practice and personal experience, both of which have so far been shown to be futile in the setting of atherosclerosis.

MicroRNA-17-5p, a novel endothelial cell modulator, controls vascular re-endothelialization and neointimal lesion formation

BACKGROUND

The functions of miR-17-5p in tumorigenesis have been explored. However, their functionalities in arterial endothelial cells (ECs) have not been investigated. Besides, the issue of vascular remodelling is barely addressed.

OBJECTIVES

The study aimed to determine the effect of overexpression or inhibition of miR-17-5p on arterial endothelial cells' (ECs) function and vascular remodelling in vitro and the rat carotid arteries model.

METHODS

Quantitative RT-PCR analysis was performed to examine the expression of miR-17-5p. Then, gain-of-function and loss-of-function approaches were employed to investigate the functional roles of miR-17-5p in cultured human coronary artery endothelial cells (HCAECs); further, TargetScan software analysis and luciferase reporter activity assay were performed to investigate the potential mechanism. Lastly, the results of the cell segment were verified in a rat carotid artery balloon injury model by Western blot analysis, measurement of the vascular cGMP level and plasma 8-iso-prostaglandin F2 (8-iso-PGF2) testing. Moreover, morphometric analysis was implemented to detect the re-endothelialization and neointimal formation in rat carotid artery after balloon injury.

RESULTS

This study firstly found that miR-17-5p expression was upregulated in the injured vascular walls and highly expressive in ECs; overexpression of miR-17-5p inhibited HCAECs' proliferation and migration, whereas miR-17-5p knockdown strengthened its proliferative and migratory roles, influenced inflammatory response, through regulating VEGRA and VEGFR2. It was found that miR-17-5p bind to VEGFA and VEGFR2 at the 3'UTR. Next, downregulation of miR-17-5p promotes re-endothelialization, and attenuates neointimal formation as measured by the I/M ratio (0.63±0.05 vs 1.45±0.06, antagomiR-17-5p vs. Lenti-NC, p < 0.05). In addition, the functional recovery of the endothelium was also accelerated by miR-17-5p knockdown.

CONCLUSION

Our study suggests that miR-17-5p is a feasible strategy for the selective modulation of endothelialization and vascular remodelling through regulating VEGFA and VEGFR2.

Association between monocyte to high-density lipoprotein ratio and coronary heart disease in US adults in the National Health and Nutrition Examination Surveys 2009-2018

BACKGROUND

Monocyte to high-density lipoprotein ratio (MHR) is associated with coronary heart disease (CHD) events. The purpose of this study was to analyze the correlation between MHR and CHD in American adults from 2009 to 2018 in the National Health and Nutrition Examination Surveys (NHANES) database.

METHODS

A total of 25 862 persons in the NHANES from 2009 to 2018 were included in the cross-sectional analysis. The independent variable was MHR and the outcome variable was CHD. MHR was obtained by dividing the number of monocytes by the high-density lipoprotein concentration, and whether it is CHD is obtained through a questionnaire. Univariate analysis, stratified analysis, and a multivariate linear regression model were used to study the correlation between MHR and CHD.

RESULTS

In each multivariate linear regression model, MHR was positively correlated with CHD, and this positive correlation was stable in both men and women [man odds ratio (OR): 1.54; 95% confidence interval (CI), 1.17-2.03; woman OR: 2.21; 95% CI, 1.40-3.50]. Our results show that the association between MHR and CHD was significant until MHR was less than 0.6 (OR: 7.2; 95% CI, 4.0-13.0); however, in cases where MHR was greater than 0.6, the results were negative but not significantly different (OR: 0.6; 95% CI, 0.3-1.2).

CONCLUSION

MHR has a clear association with CHD. Our prediction model and validation model show that MHR is highly predictive and robust as a predictor of CHD, therefore it can play an important role in the prediction of CHD.

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.

Current Evidence of Watermelon (Citrullus lanatus) Ingestion on Vascular Health: A Food Science and Technology Perspective

The amino acid L-arginine is crucial for nitric oxide (NO) synthesis, an important molecule regulating vascular tone. Considering that vascular dysfunction precedes cardiovascular disease, supplementation with precursors of NO synthesis (e.g., L-arginine) is warranted. However, supplementation of L-citrulline is recommended instead of L-arginine since most L-arginine is catabolized during its course to the endothelium. Given that L-citrulline, found mainly in watermelon, can be converted to L-arginine, watermelon supplementation seems to be effective in increasing plasma L-arginine and improving vascular function. Nonetheless, there are divergent findings when investigating the effect of watermelon supplementation on vascular function, which may be explained by the L-citrulline dose in watermelon products. In some instances, offering a sufficient amount of L-citrulline can be impaired by the greater volume (>700 mL) of watermelon needed to reach a proper dose of L-citrulline. Thus, food technology can be applied to reduce the watermelon volume and make supplementation more convenient. Therefore, this narrative review aims to discuss the current evidence showing the effects of watermelon ingestion on vascular health parameters, exploring the critical relevance of food technology for acceptable L-citrulline content in these products. Watermelon-derived L-citrulline appears as a supplementation that can improve vascular function, including arterial stiffness and blood pressure. Applying food technologies to concentrate bioactive compounds in a reduced volume is warranted so that its ingestion can be more convenient, improving the adherence of those who want to ingest watermelon products daily.

Specialized Pro-Resolving Lipid Mediators: New Therapeutic Approaches for Vascular Remodeling

Vascular remodeling is a typical feature of vascular diseases, such as atherosclerosis, aneurysms or restenosis. Excessive inflammation is a key mechanism underlying vascular remodeling via the modulation of vascular fibrosis, phenotype and function. Recent evidence suggests that not only augmented inflammation but unresolved inflammation might also contribute to different aspects of vascular diseases. Resolution of inflammation is mediated by a family of specialized pro-resolving mediators (SPMs) that limit immune cell infiltration and initiate tissue repair mechanisms. SPMs (lipoxins, resolvins, protectins, maresins) are generated from essential polyunsaturated fatty acids. Synthases and receptors for SPMs were initially described in immune cells, but they are also present in endothelial cells (ECs) and vascular smooth muscle cells (VSMCs), where they regulate processes important for vascular physiology, such as EC activation and VSMC phenotype. Evidence from genetic models targeting SPM pathways and pharmacological supplementation with SPMs have demonstrated that these mediators may play a protective role against the development of vascular remodeling in atherosclerosis, aneurysms and restenosis. This review focuses on the latest advances in understanding the role of SPMs in vascular cells and their therapeutic effects in the vascular remodeling associated with different cardiovascular diseases.

Transient Hyperglycemia and Hypoxia Induce Memory Effects in AngiomiR Expression Profiles of Feto-Placental Endothelial Cells

Gestational diabetes (GDM) and preeclampsia (PE) are associated with fetal hyperglycemia, fetal hypoxia, or both. These adverse conditions may compromise fetal and placental endothelial cells. In fact, GDM and PE affect feto-placental endothelial function and also program endothelial function and cardiovascular disease risk of the offspring in the long-term. MicroRNAs are short, non-coding RNAs that regulate protein translation and fine tune biological processes. A group of microRNAs termed angiomiRs is particularly involved in the regulation of endothelial function. We hypothesized that transient hyperglycemia and hypoxia may alter angiomiR expression in feto-placental endothelial cells (fpEC). Thus, we isolated primary fpEC after normal, uncomplicated pregnancy, and induced hyperglycemia (25 mM) and hypoxia (6.5%) for 72 h, followed by reversal to normal conditions for another 72 h. Current vs. transient effects on angiomiR profiles were analyzed by RT-qPCR and subjected to miRNA pathway analyses using DIANA miRPath, MIENTURNET and miRPathDB. Both current and transient hypoxia affected angiomiR profile stronger than current and transient hyperglycemia. Both stimuli altered more angiomiRs transiently, i.e., followed by 72 h culture at control conditions. Pathway analysis revealed that hypoxia significantly altered the pathway ‘Proteoglycans in cancer’. Transient hypoxia specifically affected miRNAs related to ‘adherens junction’. Our data reveal that hyperglycemia and hypoxia induce memory effects on angiomiR expression in fpEC. Such memory effects may contribute to long-term adaption and maladaption to hyperglycemia and hypoxia.

Vitamin D Prevents High Glucose-Induced Lipid Droplets Accumulation in Cultured Endothelial Cells: The Role of Thioredoxin Interacting Protein

Vitamin D (VitD) exerts protective effects on the endothelium, which is fundamental for vascular integrity, partly by inhibiting free radical formation. We found that VitD prevents high glucose-induced Thioredoxin Interacting Protein (TXNIP) upregulation. Increased amounts of TXNIP are responsible for the accumulation of reactive oxygen species and, as a consequence, of lipid droplets. This is associated with increased amounts of triglycerides as the result of increased lipogenesis and reduced fatty acid oxidation. Remarkably, VitD rebalances the redox equilibrium, restores normal lipid content, and prevents the accumulation of lipid droplets. Our results highlight TXNIP as one of the targets of VitD in high glucose-cultured endothelial cells and shed some light on the protective effect of VitD on the endothelium.

Effects of colchicine on tissue factor in oxLDL-activated T-lymphocytes

Several studies have shown that T-cells might be involved in pathophysiology of acute coronary syndromes (ACS). Tissue factor (TF) plays a key role in ACS. Many evidences have indicated that some statins reduce TF expression in several cell types. However, literature about rosuvastatin and TF and about statins effects on T-cells is still scanty. Colchicine is an anti-inflammatory drug recently proven to have beneficial effects in ACS via unknown mechanisms. This study investigates the effects of colchicine and rosuvastatin on TF expression in oxLDL-activated T-cells. T-cells, isolated from buffy coats of healthy volunteers, were stimulated with oxLDL (50 µg/dL). T-cells were pre-incubated with colchicine (10 µM) or rosuvastatin (5 µM) for 1 h and then stimulated with oxLDL (50 μg/mL). TF gene (RT-PCR), protein (western blot), surface expression (FACS) and procoagulant activity (FXa generation assay) were measured. NF-κB/IκB axis was examined by western blot analysis and translocation assay. Colchicine and rosuvastatin significantly reduced TF gene, and protein expression and procoagulant activity in oxLDL stimulated T-cells. This effect was associated with a significant reduction in TF surface expression as well as its procoagulant activity. These phenomena appear modulated by drug effects on the transcription factor NF-kB. Rosuvastatin and colchicine prevent TF expression in oxLDL-stimulated T-cells by modulating the NF-κB/IκB axis. Thus, we speculate that this might be another mechanism by which these drugs exert benefic cardiovascular effects.

Development of Dextran-Coated Magnetic Nanoparticles Loaded with Protocatechuic Acid for Vascular Inflammation Therapy

Vascular inflammation plays a crucial role in the progression of various pathologies, including atherosclerosis (AS), and thus it has become an attractive therapeutic target. The protocatechuic acid (PCA), one of the main metabolites of complex polyphenols, is endowed with anti-inflammatory activity, but its formulation into nanocarriers may increase its bioavailability. In this study, we developed and characterized dextran shell‒iron oxide core nanoparticles loaded with PCA (MNP-Dex/PCA) and assessed their cytotoxicity and anti-inflammatory potential on cells acting as key players in the onset and progression of AS, namely, endothelial cells (EC) and monocytes/macrophages. The results showed that MNP-Dex/PCA exert an anti-inflammatory activity at non-cytotoxic and therapeutically relevant concentrations of PCA (350 μM) as supported by the reduced levels of inflammatory molecules such as MCP-1, IL-1β, TNF-α, IL-6, and CCR2 in activated EC and M1-type macrophages and functional monocyte adhesion assay. The anti-inflammatory effect of MNP-Dex/PCA was associated with the reduction in the levels of ERK1/2 and p38-α mitogen-activated protein kinases (MAPKs) and NF-kB transcription factor. Our data support the further development of dextran shell-magnetic core nanoparticles as theranostic nanoparticles for guidance, imaging, and therapy of vascular inflammation using PCA or other anti-inflammatory compounds.

Impact of monocyte to high-density lipoprotein ratio on the identification of prevalent coronary heart disease: insights from a general population

BACKGROUND

Recent studies have identified monocyte to high-density lipoprotein ratio (MHR) as a simple, practical surrogate of atherosclerosis. Considering atherosclerosis is a major mechanism of coronary heart disease (CHD). The present study aims to evaluate the association between MHR and the prevalence of CHD.

METHODS AND RESULTS

The present cross-sectional work included 6442 participants (mean age: 59.57 years, 60.2% females), all of them were included from rural areas of northern China between October 2019 to April 2020. MHR was acquired as monocytes count divided by high-density lipoprotein concentration. Prevalent CHD researched 3.14%. After adjustment of sex, age, current drinking and smoking, BMI, WC, diabetes, hypertension, LDL-C, TG, eGFR, lipid-lowering therapy and cerebrovascular disease history, each standard deviation increase of MHR cast a 39.5% additional CHD risk. Furthermore, the top quartile of MHR had an additional 89.0% CHD risk than the bottom quartile. Besides, smooth curve fitting revealed a linear pattern of the association. Additionally, the stratified evaluation showed a robust correlation among the subgroups divided by CHD risk factors. Finally, area under the curve demonstrated an advancement when including MHR into common CHD risk factors (0.744 vs 0.761, p < 0.001). Consistently, reclassification analysis indicated the improvement from MHR (all P = 0.003).

CONCLUSION

Our work suggests the robust and linear relationship between MHR and the prevalent CHD in a general population, providing epidemiological evidence for laboratory studies. More importantly, the findings implicate the efficacy of MHR to be a potential indicator to identify the prevalent CHD.

Differentially Expressed Circular Non-coding RNAs in Atherosclerotic Aortic Vessels and Their Potential Functions in Endothelial Injury

Background: Circular non-coding RNA (circRNA) has a variety of biological functions. However, the expression profile and potential effects of circRNA on atherosclerosis (AS) and vascular endothelial injury have not been fully elucidated. This study aims to identify the differentially expressed circRNAs in atherosclerotic aortic vessels and predict their potential functions in endothelial injury.

Method: ApoE-/- mice were fed with high-fat diet for 12 weeks to induce AS. Atherosclerotic plaques were evaluated by H&E and Masson staining and immunohistochemistry; differentially expressed circRNAs were detected by Arraystar Circular RNA Microarray and verified by RT-PCR; the potential target mircoRNAs of circRNAs were predicted by miRanda, Tarbase, Targetscan and their expression changes were verified by RT-PCR; the potential target genes of mircoRNAs were predicted by Targetscan and verified by Western blot; the signaling pathways that they might annotate or regulate and their potential functions in vascular endothelial injury were predicted by gene enrichment analysis.

Results: Fifty two circRNAs were up-regulated more than twice and 47 circRNAs were down-regulated more than 1.5 times in AS aortic vessels. Mmmu_circRNA_36781 and 37699 were up-regulated both in AS aortic vessels and H₂O₂-treated mouse aortic endothelial cells (MAECs). The expression of miR-30d-3p and miR-140-3p, the target microRNA of circRNA_37699 and circRNA_36781, were downregulated both in AS vessels and H₂O₂-treated MAECs. On the contrary, MKK6 and TP53RK, the potential target gene of miR-140-3p and miR-30d-3p, were upregulated both in AS aortic roots and H₂O₂-treated MAECs. Besides, gene enrichment analysis showed that MAPK and PI3K-AKT signaling pathway were the most potential signaling pathways regulated by the differentially expressed circRNAs in atherosclerosis.

Conclusions: Mmu_circRNA_36781 (circRNA ABCA1) and 37699 (circRNA KHDRBS1) were significantly up-regulated in AS aortic vessels and H₂O₂-treated MAECs. They have potential regulatory effects on atherosclerosis and vascular endothelial injury by targeting miR-30d-3p-TP53RK and miR-140-3p-MKK6 axis and their downstream signaling pathways.

Circulating Biomarkers Reflecting Destabilization Mechanisms of Coronary Artery Plaques: Are We Looking for the Impossible?

Despite significant strides to mitigate the complications of acute coronary syndrome (ACS), this clinical entity still represents a major global health burden. It has so far been well-established that most of the plaques leading to ACS are not a result of gradual narrowing of the vessel lumen, but rather a result of sudden disruption of vulnerable atherosclerotic plaques. As most of the developed imaging modalities for vulnerable plaque detection are invasive, multiple biomarkers were proposed to identify their presence. Owing to the pivotal role of lipids and inflammation in the pathophysiology of atherosclerosis, most of the biomarkers originated from one of those processes, whereas recent advancements in molecular sciences shed light on the use of microRNAs. Yet, at present there are no clinically implemented biomarkers or any other method for that matter that could non-invasively, yet reliably, diagnose the vulnerable plaque. Hence, in this review we summarized the available knowledge regarding the pathophysiology of plaque instability, the current evidence on potential biomarkers associated with plaque destabilization and finally, we discussed if search for biomarkers could one day bring us to non-invasive, cost-effective, yet valid way of diagnosing the vulnerable, rupture-prone coronary artery plaques.

TNFα-Induced LDL Cholesterol Accumulation Involve Elevated LDLR Cell Surface Levels and SR-B1 Downregulation in Human Arterial Endothelial Cells

Excess lipid droplets are frequently observed in arterial endothelial cells at sites of advanced atherosclerotic plaques. Here, the role of tumor necrosis factor alpha (TNFα) in modulating the low-density lipoprotein (LDL) content in confluent primary human aortic endothelial cells (pHAECs) was investigated. TNFα promoted an up to 2 folds increase in cellular cholesterol, which was resistant to ACAT inhibition. The cholesterol increase was associated with increased ¹²⁵I-LDL surface binding. Using the non-hydrolysable label, Dil, TNFα could induce a massive increase in Dil-LDL by over 200 folds. The elevated intracellular Dil-LDL was blocked with excess unlabeled LDL and PCSK9, but not oxidized LDL (oxLDL), or apolipoprotein (apoE) depletion. Moreover, the TNFα-induced increase of LDL-derived lipids was elevated through lysosome inhibition. Using specific LDLR antibody, the Dil-LDL accumulation was reduced by over 99%. The effects of TNFα included an LDLR cell surface increase of 138%, and very large increases in ICAM-1 total and surface proteins, respectively. In contrast, that of scavenger receptor B1 (SR-B1) was reduced. Additionally, LDLR antibody bound rapidly in TNFα-treated cells by about 30 folds, inducing a migrating shift in the LDLR protein. The effect of TNFα on Dil-LDL accumulation was inhibited by the antioxidant tetramethythiourea (TMTU) dose-dependently, but not by inhibitors against NF-κB, stress kinases, ASK1, JNK, p38, or apoptosis caspases. Grown on Transwell inserts, TNFα did not enhance apical to basolateral LDL cholesterol or Dil release. It is concluded that TNFα promotes LDLR functions through combined increase at the cell surface and SR-B1 downregulation.

The protective effects of wine pomace products on the vascular endothelial barrier function

Endothelial dysfunction is associated with cardiovascular diseases and involves a chronic inflammatory process that together with oxidative stress increases the permeability of the vascular endothelium. The aim of this study was to evaluate the role of red and white wine pomace products (rWPPs and wWPPs) in the maintenance of endothelial integrity in hyperglycemia of EA.hy926 endothelial cells. EA.hy926 endothelial cells exposed to hyperglycemia were treated with the in vitro digested fractions of rWPPs and wWPPs. A Real Time Cellular Analysis (RTCA) system was used to evaluate the endothelial monolayer integrity after INF-γ stimulation of pre-treated endothelial cells with the digested fractions. The changes in cell viability, NO, ROS and NOX4 were recorded and actin cytoskeleton and E-cadherin junctions were evaluated by immunofluorescence. All digested fractions prevent the hyperglycemic actions in the cell viability and NO/ROS balance. The inflammatory mediator INF-γ and hyperglycemia caused a decrease in RTCA adhesion of the EA.hy926 endothelial cell monolayer. Pre-treatment with all digested fractions enhanced the EA.hy926 endothelial monolayer integrity and maintained actin cytoskeleton and E-cadherin junctions. These in vitro studies elucidate that the anti-hyperglycemic and anti-inflammatory actions of wine pomace products involve a decrease in ROS production and the stabilization of junction proteins via modulation of VE-cadherin and actin cytoskeleton suggesting a potential prevention of endothelial damage by these natural products.

Cardiovascular Outcomes in the Acute Phase of COVID-19

The cumulative number of cases in the current global coronavirus disease 19 (COVID-19) pandemic, caused by the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has exceeded 100 million, with the number of deaths caused by the infection having exceeded 2.5 million. Recent reports from most frontline researchers have revealed that SARS-CoV-2 can also cause fatal non-respiratory conditions, such as fatal cardiovascular events. One of the important mechanisms underlying the multiple organ damage that is now known to occur during the acute phase of SARS-CoV-2 infection is impairment of vascular function associated with inhibition of angiotensin-converting enzyme 2. To manage the risk of vascular dysfunction-related complications in patients with COVID-19, it would be pivotal to clearly elucidate the precise mechanisms by which SARS-CoV-2 infects endothelial cells to cause vascular dysfunction. In this review, we summarize the current state of knowledge about the mechanisms involved in the development of vascular dysfunction in the acute phase of COVID-19.

Profilin 1 and Mitochondria-Partners in the Pathogenesis of Coronary Artery Disease?

Atherosclerosis remains a large health and economic burden. Even though it has been studied for more than a century, its complex pathophysiology has not been elucidated. The relatively well-established contributors include: chronic inflammation in response to oxidized cholesterol, reactive oxygen species-induced damage and apoptosis. Recently, profilin 1, a regulator of actin dynamics emerged as a potential new player in the field. Profilin is abundant in stable atherosclerotic plaques and in thrombi extracted from infarct-related arteries in patients with acute myocardial infarction. The exact role of profilin in atherosclerosis and its complications, as well as its mechanisms of action, remain unknown. Here, we summarize several pathways in which profilin may act through mitochondria in a number of processes implicated in atherosclerosis.

Colchicine inhibits the prothrombotic effects of oxLDL in human endothelial cells

BACKGROUND

Tissue Factor (TF) plays a pivotal role in coronary thrombosis. Oxidized low-density lipoproteins (oxLDL) are crucial in development of atherosclerosclerosis. Moreover, oxLDL are known to induce TF expression on several cell types including endothelial cells. The lectin-type oxidized LDL receptor 1 (LOX-1) represent the oxLDL receptor. Colchicine is an anti-mitotic drug recently proven to have beneficial effects in cardiovascular disease via unknown mechanisms. Thus, we aim at investigating colchicine effects on TF expression in oxLDL stimulated human vascular endothelial cells (HUVEC). Some molecular mechanism(s) potentially involved were investigated.

METHODS

HUVEC were pre-incubated with colchicine 10 μM for 1 h and then stimulated with oxLDL (50 μg/mL). TF gene (RT-PCR), protein (western blot), surface expression (FACS) and procoagulant activity (FXa generation assay) were measured. TF translocation to cell surface was investigated by immunofluorescence. NF-κB/IκB axis was examined by western blot analysis and translocation assay. Finally, LOX-1 expression was also investigated.

RESULTS

Colchicine significantly reduced TF gene and protein expression as well as its procoagulant activity in oxLDL-treated HUVEC. These effects seem to be related mainly to action of colchicine on microtubules that, in turn, modulate TF trafficking in the cytoplasm, NF-κB/IκB pathway and LOX-1 expression.

CONCLUSIONS

Data of the present study, although in vitro, indicate that one of the hypothetical mechanisms by which colchicine exert protective cardiovascular effects might be its ability to inhibit the pro-thrombotic activity of oxLDL.

Acute e-cig inhalation impacts vascular health: a study in smoking naïve subjects

This study was designed to investigate the acute effects of nonnicotinized e-cigarette (e-cig) aerosol inhalation in nonsmokers both in terms of blood-based markers of inflammation and oxidative stress and evaluate their association with hemodynamic-metabolic MRI parameters quantifying peripheral vascular reactivity, cerebrovascular reactivity, and aortic stiffness. Thirty-one healthy nonsmokers were subjected to two blood draws and two identical MRI protocols, each one before and after a standardized e-cig vaping session. After vaping, the serum levels of C-reactive protein, soluble intercellular adhesion molecule, and the danger signal machinery high-mobility group box 1 (HMGB1) and its downstream effector and the NLR family pyrin domain containing 3 (NLRP3) inflammasome (as monitored by its adaptor protein ASC) increased significantly relative to the respective baseline (prevaping) values. Moreover, nitric oxide metabolites and reactive oxygen species production decreased and increased, respectively. These observations were paralleled by impaired peripheral vascular reactivity (with reduced flow-mediated dilation and attenuated hyperemic response after a cuff-occlusion test) and metabolic alterations expressed by decreased venous oxygen saturation, postvaping. The current results suggest propagation of inflammation signaling via activation of the danger signaling axis (HMGB1-NLRP3). The findings indicate that a single episode of vaping has adverse impacts on vascular inflammation and function.NEW & NOTWORTHY Endothelial cell signaling and blood biomarkers were found to correlate with functional vascular changes in a single episode e-cigarettes inhalation in healthy adults. This is indicative of the potential of e-cigarettes (even when inhaled acutely) to lead of vascular dysfunction.

The Role of Natural Killer (NK) Cells in Acute Coronary Syndrome: A Comprehensive Review

With poor outcomes and an immense financial burden, acute coronary syndrome (ACS) and its ischemic repercussions still present a major global health problem. Unfavorable outcomes seem to be mainly due to adverse cardiac remodeling. Since the inflammatory response takes an important role in remodeling secondary to myocardial infarction (MI), and as inflammation in this manner has not been completely elucidated, we attempted to give rise to a further understanding of ACS pathophysiology. Hence, in this review, we integrated current knowledge of complex communication networks between natural killer (NK) cells and immune and resident heart cells in the context of ACS. Based on available data, the role of NK cells seems to be important in the infarcted myocardium, where it affects heart remodeling. On the other hand, in atherosclerotic plaque, NK cells seem to be mere passers-by, except in the case of chronic infections by atherogenic pathogens. In that case, NK cells seem to support proinflammatory milieu. NK cell research is challenging due to ethical reasons, convergent evolution, and phenotypic diversity among individuals. Therefore, we argue that further research of NK cells in ACS is valuable, given their therapeutic potential in improving postischemic heart remodeling.

Hyperlipidaemia and IFNgamma/TNFalpha Synergism are associated with cholesterol crystal formation in Endothelial cells partly through modulation of Lysosomal pH and Cholesterol homeostasis

BACKGROUND

Inflammation plays an important role in the development of cardiovascular disease (CVD). Patients with chronic inflammation diseases have high levels of inflammation and early fatal myocardial infarction due to early, unstable coronary plaques. Cholesterol crystals (CC) play a key role in atherogenesis. However, the underlying mechanisms of endothelial cell (EC)-derived CC formation are not well understood in chronic inflammation.

METHODS

We utilized a combination of a mouse psoriasis model (K14-Rac1V12 mouse model) and human psoriasis patients to study the effect of inflammatory cytokines on CC formation in ECs. Lysosomal pH, alterations in lipid load and inflammatory proteins were evaluated as potential mechanisms linking inflammatory cytokines to CC formation. Coronary CT angiography was performed (n = 224) to characterize potential IFNγ and TNFα synergism on vascular diseases in vivo.

FINDINGS

We detected CC presence in the aorta of K14-Rac1V12 mice on chow diet. IFNγ and TNFα were found to synergistically increase LDL-induced CC formation by almost 2-fold. There was an increase in lysosomal pH accompanied by a 28% loss in pH-dependent lysosomal signal and altered vATPaseV1E1 expression patterns. In parallel, we found that LDL+IFNγ/TNFα treatments increased free cholesterol content within EC and led to a decrease in SOAT-1 expression, an enzyme critically involved cholesterol homeostasis. Finally, the product of IFNγ and TNFα positively associated with early non-calcified coronary burden in patients with psoriasis (n = 224; β = 0.28, p < 0.001).

INTERPRETATION

Our results provide evidence that IFNγ and TNFα accelerate CC formation in endothelial cells in part by altering lysosomal pH and free cholesterol load. These changes promote early atherogenesis and contribute to understanding the burden of CVD in psoriasis.

FUNDING

Funding was provided by the Intramural Research Program at NIH (NNM) and the National Psoriasis Foundation (NNM and YB).

Vitamin D inhibits Tissue Factor and CAMs expression in oxidized low-density lipoproteins-treated human endothelial cells by modulating NF-κB pathway

Epidemiologic studies have clearly demonstrated the correlation existing between Vitamin D (Vit. D) deficiency and increased risk of developing cardiovascular disease, suggesting that it might have a protective role in this clinical setting. Although many experimental studies have investigated the molecular mechanisms by which Vit. D might exert these effects, its potential role in protecting against athero-thrombosis is still partially unknown. We have investigated whether Vit. D might exert anti athero-thombotic effects by preventing expression of adhesion molecules (CAMs) and Tissue Factor (TF), molecules involved in atherothrombotic pathophysiology, in oxLDL stimulated endothelial cells (HUVEC). Moreover, we have investigated whether Vit. D effects might be due to the NF-kB modulation. HUVEC cultivated in medium enriched with Vit. D (10 nM) were stimulated with oxLDL (50 μg/ml). TF gene (RT-PCR), protein (Western blot), surface expression (FACS) and procoagulant activity (FXa generation assay) were measured. Similarly, CAMs gene (RT-PCR), surface expression (FACS) and soluble values (ELISA) were measured. NF-kB translocation was also investigated. Vit. D significantly reduced TF gene as well protein expression and procoagulant activity in oxLDL-treated HUVEC. Similar effects were observed for CAMs. These effects were associated with Vit. D modulation of NF-κB pathway. This study, although in vitro, indicate that Vit. D has protective effect on endothelial cells by inhibiting expression of TF and CAMs, proteins involved in atherothrombotic pathophysiology. Further studies will be necessary to translate these findings to a clinical scenario to better define the potential therapeutical role of Vit. D supplementation in the management of cardiovascular disease in patients with Vit. D deficiency.

Integral role of receptor for advanced glycation end products (RAGE) in nondiabetic atherosclerosis

An advanced glycation end products (AGE)/a receptor for AGE (RAGE) axis plays a central role in the pathogenesis of diabetic vascular remodeling. This study was conducted to clarify the role of RAGE in nondiabetic atherosclerosis. We used the aortic and coronary atherosclerotic lesions of Watanabe heritable hyperlipidemic (WHHL) rabbits prone to myocardial infarction (WHHLMI) at 1 to 14 months. Immunohistochemistry demonstrated the significant expression of RAGE as early as at 1 month with the stronger expression at 3 and 7 months, which was remarkably diminished at 14 months. RAGE expression was concordant with AGE accumulation. The major original sources of RAGE expression were macrophages and smooth muscle cells in addition to endothelial cells, and RAGE expression was distributed in the areas of phospholipid products, a component of oxidized LDL and nitrotyrosine. The concentrations of serum AGE did not alter significantly with aging. These findings suggested the expression of RAGE was induced by hyperlipidemia and oxidative stress independent of diabetes in WHHLMI rabbits. Additionally, our in vitro study showed that silencing of RAGE tended to attenuate oxidized-LDL-triggered PAI-1 expression in human cultured macrophages, as well as oxidized-LDL-induced tissue factor expression in peritoneal macrophages, suggesting a possible role of RAGE in prothrombogenic molecular regulation. In conclusion, the present study provides in vivo evidence that RAGE plays an integral role in the initiation and progression of nondiabetic atherosclerosis, suggesting that RAGE may be a novel target for treating not only diabetic but also nondiabetic vascular complications.

Laboratory Parameters of Hemostasis, Adhesion Molecules, and Inflammation in Type 2 Diabetes Mellitus: Correlation with Glycemic Control

Background: Type 2 diabetes mellitus (T2DM) is characterized by a prothrombotic state, predisposing to vascular complications. Some related markers, linking thrombophilia to hemostasis and inflammation, however, have been poorly explored in relation to patients’ glycemia. We therefore investigated the association of laboratory hemostatic parameters, circulating adhesion molecules (ADMs), white blood cell (WBC) count, and neutrophil/lymphocyte ratio (NLR) with T2DM and glycemic control. Research design: In this study, 82 subjects, grouped into T2DM patients (n = 41) and healthy individuals (n = 41) were enrolled. To evaluate glycemic control, the T2DM cohort was expanded to 133 patients and sub-classified according to glycated hemoglobin (HbA1c) <7% and ≥ 7% (n = 58 and n = 75, respectively). We assessed glycemia, HbA1c, prothrombin time (PT), activated partial thromboplastin time (aPTT), fibrinogen, plasminogen activator inhibitor-1 (PAI-1), platelet and leukocyte parameters, vascular cell adhesion molecule 1 (VCAM-1), intercellular adhesion molecule 1 (ICAM-1), and selectins (E-, P-, L-). Results: PT % activity, PAI-1, VCAM-1, WBC, and neutrophil counts were significantly higher in T2DM patients than in healthy subjects. Poor glycemic control (HbA1c ≥ 7%) was correlated with increased PT activity (p = 0.015), and higher levels of E-selectin (p = 0.009), P-selectin (p = 0.012), and NLR (p = 0.019). Conclusions: Both T2DM and poor glycemic control affect some parameters of hemostasis, inflammation, and adhesion molecules. Further studies are needed to establish their clinical utility as adjuvant markers for cardio-vascular risk in T2DM patients.

Biointerface topography mediates the interplay between endothelial cells and monocytes

Endothelial cell (EC) monolayers located in the inner lining of blood vessels serve as a semipermeable barrier between circulating blood and surrounding tissues. The structure and function of the EC monolayer affect the recruitment and adhesion of monocytes, which plays a pivotal role in the development of inflammation and atherosclerosis. Here we investigate the effect of material wrinkled topographies on the responses of human umbilical vein endothelial cells (HUVECs) and adhesion of monocytes to HUVECs. It is found that HUVEC responses are non-linearly mediated by surface topographies with different dimensions. Specifically, more cell elongation and better cell orientation on the wrinkled surface with a 3.5 μm amplitude and 10 μm wavelength (W10) are observed compared to other surfaces. The proliferation rate of HUVECs on the W10 surface is higher than that on other surfaces due to more 5-ethynyl-2′-deoxyuridine (EdU) detected on the W10 surface. Also, greater expression of inflammatory cytokines from HUVECs and adhesion of monocytes to HUVECs on the W10 surface is shown than other surfaces due to greater expression of p-AKT and ICAM, respectively. This study offers a new in vitro system to understand the interplay between HUVEC monolayers and monocytes mediated by aligned topographies, which may be useful for vascular repair and disease modeling for drug testing.

This study offers a new in vitro system to understand the interplay between HUVEC monolayer and monocytes mediated by aligned topographies, which may be useful for vascular repair and disease modeling for drug testing.

Spontaneous hemangioendothelial cell hyperplasia of the heart in a young ICR mouse

Spontaneous nonneoplastic proliferative lesions of the cardiac hemangioendothelium are extremely rare in humans and animals. Here, we describe a spontaneous hemangioendothelial cell hyperplasia in the heart of a 9-week-old male ICR mouse. The lesion was observed focally in the interventricular septum, with no compression of the surrounding tissues. In the lesion, a single layer of hemangioendothelial cells that had a polygonal shape with enlarged nuclei and plump cytoplasm closely lined surrounding widened capillary vascular spaces and cardiac muscles. There was little cellular atypia, and there were no multilayered endothelial cells. Immunohistochemical staining revealed that these cells were partly positive for factor VIII and CD31, hemangioendothelial cell markers, and negative for Ki-67. These features were consistent with those in aged female B6C3F₁ mice in the only report in mice of spontaneous cardiac hemangioendothelial cell hyperplasia. Therefore, this is the first report of spontaneous hemangioendothelial cell hyperplasia in the heart of a young mouse.

Apolipoprotein E Deficiency Causes Endothelial Dysfunction in the Mouse Retina

Objective

Atherogenic lipoproteins may impair vascular reactivity consecutively causing tissue damage in multiple organs via abnormal perfusion and excessive reactive oxygen species generation. We tested the hypothesis that chronic hypercholesterolemia causes endothelial dysfunction and cell loss in the retina.

Methods

Twelve-month-old apolipoprotein E-deficient (ApoE-/-) mice and age-matched wild-type controls were used in this study (n = 8 per genotype for each experiment). Intraocular pressure, blood pressure, and ocular perfusion pressure were determined. Retinal arteriole responses were studied in vitro, and reactive oxygen and nitrogen species were quantified in the retinal and optic nerve cryosections. The expression of the lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1) and the NADPH oxidase isoforms, NOX1, NOX2, and NOX4, were determined in retinal cryosections by immunofluorescence microscopy. Pro- and antioxidant redox genes were quantified in retinal explants by PCR. Moreover, cell number in the retinal ganglion cell layer and axon number in the optic nerve was calculated.

Results

Responses to the endothelium-dependent vasodilator, acetylcholine, were markedly impaired in retinal arterioles of ApoE-/- mice (P < 0.01). LOX-1 (P = 0.0007) and NOX2 (P = 0.0027) expressions as well as levels of reactive oxygen species (P = 0.0022) were increased in blood vessels but not in other retinal structures. In contrast, reactive nitrogen species were barely detectable in both mouse genotypes. Messenger RNA for HIF-1α, VEGF-A, NOX1, and NOX2, but also for various antioxidant redox genes was elevated in the retina of ApoE-/- mice. Total cell number in the retinal ganglion cell layer did not differ between ApoE-/- and wild-type mice (P = 0.2171). Also, axon number in the optic nerve did not differ between ApoE-/- and wild-type mice (P = 0.6435).

Conclusion

Apolipoprotein E deficiency induces oxidative stress and endothelial dysfunction in retinal arterioles, which may trigger hypoxia in the retinal tissue. Oxidative stress in nonvascular retinal tissue appears to be prevented by the upregulation of antioxidant redox enzymes, resulting in neuron preservation.

Lipoproteins in Atherosclerosis Process

BACKGROUND

Dyslipidaemias is a recognized risk factor for atherosclerosis, however, new evidence brought to light by trials investigating therapies to enhance HDLcholesterol have suggested an increased atherosclerotic risk when HDL-C is high.

RESULTS

Several studies highlight the central role in atherosclerotic disease of dysfunctional lipoproteins; oxidised LDL-cholesterol is an important feature, according to "oxidation hypothesis", of atherosclerotic lesion, however, there is today a growing interest for dysfunctional HDL-cholesterol. The target of our paper is to review the functions of modified and dysfunctional lipoproteins in atherogenesis.

CONCLUSION

Taking into account the central role recognized to dysfunctional lipoproteins, measurements of functional features of lipoproteins, instead of conventional routine serum evaluation of lipoproteins, could offer a valid contribution in experimental studies as in clinical practice to stratify atherosclerotic risk.

Ultramorphological analysis of plaque advancement and cholesterol crystal formation in Ldlr knockout mouse atherosclerosis

BACKGOUND AND AIMS

The low-density lipoprotein receptor-deficient (Ldlr^-/-) mouse has been utilized by cardiovascular researchers for more than two decades to study atherosclerosis. However, there has not yet been a systematic effort to document the ultrastructural changes that accompany the progression of atherosclerotic plaque in this model.

METHODS

Employing several different staining and microscopic techniques, including immunohistochemistry, as well as electron and polarized microscopy, we analyzed atherosclerotic lesion development in Ldlr^-/- mice fed an atherogenic diet over time.

RESULTS

Lipid-like deposits occurred in the subendothelial space after only one week of atherogenic diet. At two weeks, cholesterol crystals (CC) formed and increased thereafter. Lipid, CC, vascular smooth muscles cells, and collagen progressively increased over time, while after 4 weeks, relative macrophage content decreased. Accelerated accumulation of plate- and needle-shaped CC accompanied plaque core necrosis. Lastly, CC were surrounded by cholesterol microdomains, which co-localized with CC through all stages of atherosclerosis, indicating that the cholesterol microdomains may be a source of CC.

CONCLUSIONS

Here, we have documented, for the first time in a comprehensive way, atherosclerotic plaque morphology and composition from early to advanced stages in the Ldlr^-/- mouse, one of the most commonly used animal models utilized in atherosclerosis research.

The impact of monocyte to high-density lipoprotein ratio on reduced renal function: insights from a large population

Aim: To investigate whether monocyte to HDL cholesterol ratio (MHR) can improve the risk stratification of reduced renal function by estimating atherosclerosis. Patients & methods: The cross-sectional study included 8159 subjects (males: 45.73%, mean age: 54.12 years) from Northeast China in 2013. Results: Each standard deviation increase of MHR brought 42.9% additional risk of reduced renal function in males. In females, MHR strongly correlated with reduced renal function before it reached a breakpoint (MHR = 0.25). Additionally, net reclassification improvement identified the value of MHR (0.199; 95% CI: 0.030–0.369; p = 0.021) to improve the risk classification of renal function reduction. Conclusion: This study implicates that MHR is independently associated with reduced renal function and can refine the risk stratification of renal function reduction.

Assessing the performance of monocyte to high-density lipoprotein ratio for predicting ischemic stroke: insights from a population-based Chinese cohort

Background

Monocyte to high-density lipoprotein cholesterol ratio (MHR) is a recently emerged measure of inflammation and oxidative stress and has been used to predict multiple cardiovascular abnormalities, but data relative to ischemic stroke are lacking. The goal of this study was to estimate the associations of MHR and prevalent ischemic stroke among a large cohort of general Chinese population.

Method

The study analyzed 8148 individuals (mean age: 54.1 years; 45.7% males) enrolled in a cross-sectional population-based Northeast China Rural Cardiovascular Health Study (NCRCHS). We identified 194 patients admitted from January and August 2013 with ischemic stroke.

Results

After adjustment for age, sex, and potential confounders, each standard deviation (SD) increment of MHR was predictive to a greater odd of ischemic stroke (odds ratio, 1.276; 95% confidence interval [CI], 1.082–1.504), with subjects in the highest quartile of MHR levels having a 1.6-fold higher risk of prevalent ischemic stroke (95% CI, 1.045–2.524) as compared with those in the lowest quartile. Moreover, smoothing curve showed a linear positive pattern of this association. The area under the curve (AUC) significantly increased (P = 0.042) to 0.808 (95% CI, 0.779–0.837) when the combined MHR was added to the baseline logistic regression model with ischemic stroke risk factors. Also, MHR (0.004) significantly improved integrated discrimination improvement when added to the baseline model.

Conclusions

The present study demonstrated for the first time a linear relation between MHR levels and the odds of ischemic stroke in a large community-based population. The MHR, a marker of high atherosclerotic burden, demonstrated incremental predictive value over traditional clinical risk factors, thus providing clinical utility in risk stratification in subjects presenting with ischemic stroke. These findings had implications for strategies aimed at lowering MHR to prevent adverse cardiovascular and cerebrovascular outcomes.

How many cadherins do human endothelial cells express?

The vasculature is the paradigm of a compartment generated by parallel cellular barriers that aims to transport oxygen, nutrients and immune cells in complex organisms. Vascular barrier dysfunction leads to fatal acute and chronic inflammatory diseases. The endothelial barrier lines the inner side of vessels and is the main regulator of vascular permeability. Cadherins comprise a superfamily of 114 calcium-dependent adhesion proteins that contain conserved cadherin motifs and form cell-cell junctions in metazoans. In mature human endothelial cells, only VE (vascular endothelial)-cadherin and N (neural)-cadherin have been investigated in detail. Although both cadherins are essential for regulating endothelial permeability, no comprehensive expression studies to identify which other family members could play a relevant role in endothelial cells has so far been performed. Here, we have reviewed gene and protein expression databases to analyze cadherin expression in mature human endothelium and found that at least 24 cadherin superfamily members are significantly expressed. Based on data obtained from other cell types, organisms and experimental models, we discuss their potential functions, many of them unrelated to the formation of endothelial cell-cell junctions. The expression of this new set of endothelial cadherins highlights the important but still poorly defined roles of planar cell polarity, the Hippo pathway and mitochondria metabolism in human vascular homeostasis.

Anti-hypercholesterolemic Effects and a Good Safety Profile of SCM-198 in Animals: From ApoE Knockout Mice to Rhesus Monkeys

Although several lipid-lowering agents have been introduced for the treatment of atherosclerosis (AS), currently marketed medications have not solved the problem completely. This study aims to investigate the effects of leonurine (SCM-198) on dyslipidemia in mammals with ApoE knockout (ApoE^-/-) mice, New Zealand white rabbits and senile Rhesus monkeys fed with high fat diet were dosed daily with leonurine or atorvastatin. The serum total cholesterol (TC), triglyceride (TG), low density lipoprotein (LDL), and high-density lipoprotein (HDL) were determined. Moreover, in Rhesus monkeys, bodyweight, arterial ultrasound of right common carotid artery, Apolipoprotein A1 (ApoA1) and ApoB levels, hematologic and toxicological examinations were detected. Serum TC and TG in both mice and rabbits were significantly reduced by SCM-198 and atorvastatin. In the 10 mg/kg SCM-198 group of monkeys, maximum TC reduction of 24.05% was achieved at day 150, while 13.16% LDL reduction achieved at day 60, without arterial morphologic changes or adverse events. Atorvastatin (1.2 mg/kg) showed similar effects as SCM-198 in improving lipid profiles in monkeys, yet its long-term use could induce tolerance. Furthermore, leonurine suppressed genes expression of fatty acid synthesis, such as fatty acid synthase (FASN), stearoyl-CoA desaturase (SCD-1), sterol regulatory element-binding protein (SREBF) in liver in high fat diet feeding ApoE^-/- mice. SCM-198, with a reliable safety profile, is of high value in improving lipid profiles in mammals, providing an alternative to a substantial population who are statin-intolerant.

Biological Effects of Tetrahydroxystilbene Glucoside: An Active Component of a Rhizome Extracted from Polygonum multiflorum

Polygonum multiflorum Thunb. (PM), a traditional Chinese medicinal herb, has been widely used in the Orient as a tonic and antiaging agent. 2,3,5,4'-Tetrahydroxystilbene-2-O-β-D-glucoside (TSG, C20H22O9, FW = 406.38928) is one of the active components extracted from PM. TSG is an antioxidant agent, which exhibits remarkable antioxidative activities in vivo and in vitro. The antioxidant effect of TSG is achieved by its radical-scavenging effects. TSG can inhibit apoptosis and protect neuronal cells against injury through multifunctional cytoprotective pathways. TSG performs prophylactic and therapeutic activities against Alzheimer's disease, Parkinson's disease, and cerebral ischemia/reperfusion injury. It is also antiatherosclerotic and anti-inflammatory. However, the mechanisms underlying these pharmacological activities are unclear. This study aimed at reviewing experimental studies and describing the effectiveness and possible mechanisms of TSG.

CTRP5 promotes transcytosis and oxidative modification of low-density lipoprotein and the development of atherosclerosis

BACKGROUND AND AIMS

Increased transcytosis of low-density lipoprotein (LDL) across the endothelium and oxidation of LDL deposited within the subendothelial space are crucial early events in atherogenesis. C1q/TNF-related protein (CTRP) 5 is a novel secreted glycoprotein and its biological functions are largely undefined.

METHODS

Expression of CTRP5 was analyzed in sera and atherosclerotic plaques of patients with coronary artery disease (CAD). The role of CTRP5 in atherogenesis was investigated in vitro and in vivo.

RESULTS

We found CTRP5 serum levels were higher in patients with than without CAD (247.26 ± 61.71 vs. 167.81 ± 68.08 ng/mL, p < 0.001), and were positively correlated with the number of diseased vessels (Spearman's r = 0.611, p < 0.001). Increased expression of CTRP5 was detected in human coronary endarterectomy specimens as compared to non-atherosclerotic arteries. Immunofluorescence further showed that CTRP5 was predominantly localized in the endothelium, infiltrated macrophages and smooth muscle cells in the neointima. In vivo and in vitro experiments demonstrated that CTRP5 promoted transcytosis of LDL across endothelial monolayers, as well as the oxidative modification of LDL in endothelial cells. Mechanistically, we found that CTRP5 up-regulated 12/15-lipoxygenase (LOX), a key enzyme in mediating LDL trafficking and oxidation, through STAT6 signaling. Genetic or pharmacological inhibition of 12/15-LOX dramatically attenuated the deposition of oxidized LDL in the subendothelial space and the development of atherosclerosis.

CONCLUSIONS

These data indicate that CTRP5 is a novel pro-atherogenic cytokine and promotes transcytosis and oxidation of LDL in endothelial cells via up-regulation of 12/15-LOX.

Strategy for marker-based differentiation of pro- and anti-inflammatory macrophages using matrix-assisted laser desorption/ionization mass spectrometry imaging

Macrophages are large phagocytes playing a crucial role in the development and progression of atherosclerosis. The phenotypic polarization and activation of macrophages in atherosclerotic plaques depends on their complex micro-environment and at the same time has a major impact on the vulnerability or stability of advanced atherosclerotic lesions. Many in vitro and in vivo studies have been designed to define markers for macrophage subtypes to better understand the mechanism of plaque progression but they have rather added to the confusion. Nonetheless, some of the in vitro defined macrophage subtypes, like the pro-inflammatory M1 or the anti-inflammatory M2a/b/c macrophage, have been shown to be present in atherosclerotic plaques. Herein, we developed a comprehensive workflow to distinguish between human in vitro differentiated pro-inflammatory M1 and anti-inflammatory M2a and M2c macrophages. The cells were analyzed using qPCR and FACS analyses for defining suitable markers on the transcript (mRNA) and protein level as well as MALDI MSI for the assignment of metabolic markers, which can be used for the identification of the corresponding macrophage subtypes in atherosclerotic plaques. Data obtained using both qPCR and FACS analyses were in agreement with the literature. For the analysis of the macrophages with MALDI MSI, a comprehensive workflow was developed and the obtained data were subjected to different statistical analysis methods like principal component analysis (PCA) to define markers for each macrophage type. Our MALDI MSI results revealed that the method produces reliable and reproducible results but that the heterogeneity of the monocytes derived from different donors is too high to define universal markers on the metabolic level. Moreover, the results show that a sample set of three biological replicates is not sufficient to obtain representative data and therefore we recommend performing ring experiments in which the samples are measured by different laboratories.

Endocytosis of lipoproteins

During their metabolism, all lipoproteins undergo endocytosis, either to be degraded intracellularly, for example in hepatocytes or macrophages, or to be re-secreted, for example in the course of transcytosis by endothelial cells. Moreover, there are several examples of internalized lipoproteins sequestered intracellularly, possibly to exert intracellular functions, for example the cytolysis of trypanosoma. Endocytosis and the subsequent intracellular itinerary of lipoproteins hence are key areas for understanding the regulation of plasma lipid levels as well as the biological functions of lipoproteins. Indeed, the identification of the low-density lipoprotein (LDL)-receptor and the unraveling of its transcriptional regulation led to the elucidation of familial hypercholesterolemia as well as to the development of statins, the most successful therapeutics for lowering of cholesterol levels and risk of atherosclerotic cardiovascular diseases. Novel limiting factors of intracellular trafficking of LDL and the LDL receptor continue to be discovered and to provide drug targets such as PCSK9. Surprisingly, the receptors mediating endocytosis of high-density lipoproteins or lipoprotein(a) are still a matter of controversy or even new discovery. Finally, the receptors and mechanisms, which mediate the uptake of lipoproteins into non-degrading intracellular itineraries for re-secretion (transcytosis, retroendocytosis), storage, or execution of intracellular functions, are largely unknown.