[Zhuyu Pills promote polarization of macrophages toward M2 phenotype to prevent atherosclerosis via PPARγ/NF-κB signaling pathway].

This article aims to investigate the effect of Zhuyu Pills on atherosclerosis and decipher the underlying mechanism. The mouse model of atherosclerosis was induced by a high-fat diet, and the total modeling period was 12 weeks. A total of 47 ApoE~(-/-) mice successfully modeled were randomized into 5 groups, including 10 in the model group, 9 in each of low-, medium-, and high-dose(130.54, 261.08 and 522.16 mg·kg~(-1)·d~(-1), respectively) Zhuyu Pills groups, and 10 in the atorvastatin calcium(10.40 mg·kg~(-1)·d~(-1)) group. In addition, 10 C57BL/6J mice were included as the normal group. The mice in the normal group and model group were administrated with an equal volume of sterile distilled water, and those in other groups with corresponding agents by gavage once a day for 12 weeks. At the end of drug intervention, the levels of total cholesterol(TC), triglyceride(TG), high-density lipoprotein cholesterol(HDL-C), and low-density lipoprotein cholesterol(LDL-C) were measured by the biochemical method. Hematoxylin-eosin(HE) staining was employed to observe the plaque distribution in the aortic region. The serum levels of pro-inflammatory cytokines tumor necrosis factor-α(TNF-α) and interleukin(IL)-6 in M1 macrophages and anti-inflammatory cytokines IL-13 and IL-4 in M2 macrophages were determined by enzyme-linked immunosorbent assay(ELISA). The expression levels of inducible nitric oxide synthase(iNOS) and arginase-1(Arg-1) were examined by immunofluorescence. Real-time fluorescence quantitative polymerase chain reaction(real-time PCR) was employed to measure the mRNA levels of peroxisome proliferator-activated receptor γ(PPARγ), nuclear factor-κB(NF-κB), Arg-1, and iNOS in the aorta. Western blot was employed to determine the protein levels of PPARγ and NF-κB in the aorta. The results showed that compared with the normal group, the modeling elevated the TC, TG, and LDL-C levels, lowered the HDL-C level, caused large area thickening of the aortic intima, elevated the TNF-α and IL-6 levels, lowered the IL-4 and IL-13 levels, down-regulated the mRNA and protein levels of PPARγ and Arg-1, and up-regulated the mRNA and protein levels of iNOS and NF-κB in the aorta(P<0.01). Compared with the model group, low-, medium-, and high-dose Zhuyu Pills and atorvastatin calcium lowered the TC, TG, and LDL-C levels, elevated the HDL-C level, reduced the plaque area in a concentration-dependent manner, lowered the TNF-α and IL-6 levels, elevated the IL-4 and IL-13 levels, up-regulated the mRNA and protein levels of PPARγ and Arg-1, and down-regulated the mRNA and protein levels of NF-κB and iNOS in the aorta(P<0.05 or P<0.01). In conclusion, Zhuyu Pills may play an anti-atherosclerosis role by regulating PPARγ/NF-κB signaling pathway, inhibiting the polarization of macrophages toward the M1 phenotype, promoting the polarization of macrophages toward the M2 phenotype, and improving the inflammatory microenvironment of macrophages.

Long-term dietary nitrate supplementation slows the progression of established atherosclerosis in ApoE-/- mice fed a high fat diet.

BACKGROUND AND AIMS: Atherosclerosis is associated with a reduction in the bioavailability and/or bioactivity of endogenous nitric oxide (NO). Dietary nitrate has been proposed as an alternate source when endogenous NO production is reduced. Our previous study demonstrated a protective effect of dietary nitrate on the development of atherosclerosis in the apoE-/- mouse model. However most patients do not present clinically until well after the disease is established. The aims of this study were to determine whether chronic dietary nitrate supplementation can prevent or reverse the progression of atherosclerosis after disease is already established, as well as to explore the underlying mechanism of these cardiovascular protective effects. METHODS: 60 apoE-/- mice were given a high fat diet (HFD) for 12 weeks to allow for the development of atherosclerosis. The mice were then randomized to (i) control group (HFD + 1 mmol/kg/day NaCl), (ii) moderate-dose group (HFD +1 mmol/kg/day NaNO3), or (iii) high-dose group (HFD + 10 mmol/kg/day NaNO3) (20/group) for a further 12 weeks. A group of apoE-/- mice (n = 20) consumed a normal laboratory chow diet for 24 weeks and were included as a reference group. RESULTS: Long-term supplementation with high dose nitrate resulted in ~ 50% reduction in plaque lesion area. Collagen expression and smooth muscle accumulation were increased, and lipid deposition and macrophage accumulation were reduced within atherosclerotic plaques of mice supplemented with high dose nitrate. These changes were associated with an increase in nitrite reductase as well as activation of the endogenous eNOS-NO pathway. CONCLUSION: Long-term high dose nitrate significantly attenuated the progression of established atherosclerosis in the apoE-/- mice fed a HFD. This appears to be mediated in part through a XOR-dependent reduction of nitrate to NO, as well as enhanced eNOS activation via increased Akt and eNOS phosphorylation.

Targeting the CCL2-CCR2 axis for atheroprotection.

Decades of research have established atherosclerosis as an inflammatory disease. Only recently though, clinical trials provided proof-of-concept evidence for the efficacy of anti-inflammatory strategies with respect to cardiovascular events, thus offering a new paradigm for lowering residual vascular risk. Efforts to target the inflammasome-interleukin-1ß-interleukin-6 pathway have been highly successful, but inter-individual variations in drug response, a lack of reduction in all-cause mortality, and a higher rate of infections also highlight the need for a second generation of anti-inflammatory agents targeting atherosclerosis-specific immune mechanisms while minimizing systemic side effects. CC-motif chemokine ligand 2/monocyte-chemoattractant protein-1 (CCL2/MCP-1) orchestrates inflammatory monocyte trafficking between the bone marrow, circulation, and atherosclerotic plaques by binding to its cognate receptor CCR2. Adding to a strong body of data from experimental atherosclerosis models, a coherent series of recent large-scale genetic and observational epidemiological studies along with data from human atherosclerotic plaques highlight the relevance and therapeutic potential of the CCL2-CCR2 axis in human atherosclerosis. Here, we summarize experimental and human data pinpointing the CCL2-CCR2 pathway as an emerging drug target in cardiovascular disease. Furthermore, we contextualize previous efforts to interfere with this pathway, scrutinize approaches of ligand targeting vs. receptor targeting, and discuss possible pathway-intrinsic opportunities and challenges related to pharmacological targeting of the CCL2-CCR2 axis in human atherosclerotic disease.

Cardiovascular events and atherosclerosis in patients with type 2 diabetes and impaired glucose tolerance: What are the medical treatments to prevent cardiovascular events in such patients?

Type 2 diabetes mellitus and impaired glucose tolerance (IGT) significantly induce advanced coronary artery disease and systemic atherosclerosis. Thus, type 2 diabetes mellitus and IGT are traditional risk factors of cardiovascular disease. In contrast, acute coronary syndrome is frequently caused by the rupture of coronary atherosclerotic plaques, which reduces patients' quality of life and might result in death. To date, many trials have sought to identify ways to determine the coronary plaque volume and its vulnerability, and many studies have shown that some specific antihyperglycemic agents might prevent coronary or carotid plaque progression, decrease plaque volume, induce plaque stability, and improve clinical outcomes in patients with type 2 diabetes mellitus and IGT. This article reviews the following: (i) the association between coronary or carotid plaques and abnormal glucose tolerance, including type 2 diabetes mellitus; and (ii) the effects of oral antihyperglycemic drugs to improve clinical outcomes and stabilize atherosclerotic plaques in patients with type 2 diabetes mellitus and IGT.

Neuroimmune cardiovascular interfaces control atherosclerosis.

Atherosclerotic plaques develop in the inner intimal layer of arteries and can cause heart attacks and strokes1. As plaques lack innervation, the effects of neuronal control on atherosclerosis remain unclear. However, the immune system responds to plaques by forming leukocyte infiltrates in the outer connective tissue coat of arteries (the adventitia)2-6. Here, because the peripheral nervous system uses the adventitia as its principal conduit to reach distant targets7-9, we postulated that the peripheral nervous system may directly interact with diseased arteries. Unexpectedly, widespread neuroimmune cardiovascular interfaces (NICIs) arose in mouse and human atherosclerosis-diseased adventitia segments showed expanded axon networks, including growth cones at axon endings near immune cells and media smooth muscle cells. Mouse NICIs established a structural artery-brain circuit (ABC): abdominal adventitia nociceptive afferents10-14 entered the central nervous system through spinal cord T6-T13 dorsal root ganglia and were traced to higher brain regions, including the parabrachial and central amygdala neurons; and sympathetic efferent neurons projected from medullary and hypothalamic neurons to the adventitia through spinal intermediolateral neurons and both coeliac and sympathetic chain ganglia. Moreover, ABC peripheral nervous system components were activated: splenic sympathetic and coeliac vagus nerve activities increased in parallel to disease progression, whereas coeliac ganglionectomy led to the disintegration of adventitial NICIs, reduced disease progression and enhanced plaque stability. Thus, the peripheral nervous system uses NICIs to assemble a structural ABC, and therapeutic intervention in the ABC attenuates atherosclerosis.

5-Heptadecylresorcinol Protects against Atherosclerosis in Apolipoprotein E-Deficient Mice by Modulating SIRT3 Signaling: The Possible Beneficial Effects of Whole Grain Consumption.

SCOPE: Whole grain consumption has been proven to be inversely associated with the risk of cardiovascular diseases. As a biomarker for whole grain dietary intake, 5-heptadecylresorcinol (AR-C17) has attracted increased attention due to its potential health-improving activity. However, the beneficial effect of AR-C17 on atherosclerosis prevention and the underlying mechanism remain unclear. METHODS AND RESULTS: High-fat diet fed apolipoprotein E-deficient (ApoE-/- ) mice are administrated with or without AR-C17 (30 and 150 mg kg-1 ) for 16 weeks. Histological staining is performed for plaque analysis. Immunofluorescence, western blot, and seahorse cell analysis are carried out to investigate the action of mechanism of AR-C17. The results indicate that AR-C17 supplementation lowered serum total cholesterol, triglyceride, VLDL-C, and LDL-C levels. Moreover, the atherosclerotic plaques in the aortic root region of mice heart are significantly reduced by AR-C17 intervention compared with ApoE-/- control group. In addition, AR-C17 treatment alleviates endothelial cell damage and apoptosis by improving mitochondrial function via sirtuin3 signaling pathway both in ApoE-/- mice and oxidized-LDL-treated human umbilical vein endothelial cells. CONCLUSION: AR-C17 may be applied as a promising grain-based dietary bioactive ingredient for atherosclerosis prevention. Meanwhile, as a mitochondrial protective agent, it can offer support for the suggested health claim of whole grain diet.

Ablation of Plasma Prekallikrein Decreases Low-Density Lipoprotein Cholesterol by Stabilizing Low-Density Lipoprotein Receptor and Protects Against Atherosclerosis.

BACKGROUND: High blood cholesterol accelerates the progression of atherosclerosis, which is an asymptomatic process lasting for decades. Rupture of atherosclerotic plaques induces thrombosis, which results in myocardial infarction or stroke. Lowering cholesterol levels is beneficial for preventing atherosclerotic cardiovascular disease. METHODS: Low-density lipoprotein (LDL) receptor (LDLR) was used as bait to identify its binding proteins in the plasma, and the coagulation factor prekallikrein (PK; encoded by the KLKB1 gene) was revealed. The correlation between serum PK protein content and lipid levels in young Chinese Han people was then analyzed. To investigate the effects of PK ablation on LDLR and lipid levels in vivo, we genetically deleted Klkb1 in hamsters and heterozygous Ldlr knockout mice and knocked down Klkb1 using adeno-associated virus-mediated shRNA in rats. The additive effect of PK and proprotein convertase subtilisin/kexin 9 inhibition also was evaluated. In addition, we applied the anti-PK neutralizing antibody that blocked the PK and LDLR interaction in mice. Mice lacking both PK and apolipoprotein e (Klkb1-/-Apoe-/-) were generated to assess the role of PK in atherosclerosis. RESULTS: PK directly bound LDLR and induced its lysosomal degradation. The serum PK concentrations positively correlated with LDL cholesterol levels in 198 young Chinese Han adults. Genetic depletion of Klkb1 increased hepatic LDLR and decreased circulating cholesterol in multiple rodent models. Inhibition of proprotein convertase subtilisin/kexin 9 with evolocumab further decreased plasma LDL cholesterol levels in Klkb1-deficient hamsters. The anti-PK neutralizing antibody could similarly lower plasma lipids through upregulating hepatic LDLR. Ablation of Klkb1 slowed the progression of atherosclerosis in mice on Apoe-deficient background. CONCLUSIONS: PK regulates circulating cholesterol levels through binding to LDLR and inducing its lysosomal degradation. Ablation of PK stabilizes LDLR, decreases LDL cholesterol, and prevents atherosclerotic plaque development. This study suggests that PK is a promising therapeutic target to treat atherosclerotic cardiovascular disease.

Predictive mouse model reflects distinct stages of human atheroma in a single carotid artery.

Identification of patients with high-risk asymptomatic atherosclerotic plaques remains an elusive but essential step in preventing stroke. However, there is a lack of animal model that provides a reproducible method to predict where, when and what types of plaque formation, which fulfils the American Heart Association (AHA) histological classification of human plaques. We have developed a predictive mouse model that reflects different stages of human plaques in a single carotid artery by means of shear-stress modifying cuff. Validated with over 30000 histological sections, the model generates a specific pattern of plaques with different risk levels along the same artery depending on their position relative to the cuff. The further upstream of the cuff-implanted artery, the lower the magnitude of shear stress, the more unstable the plaques of higher grade according to AHA classification; with characteristics including greater degree of vascular remodeling, plaque size, plaque vulnerability and inflammation, resulting in higher risk plaques. By weeks 20 and 30, this model achieved 80% and near 100% accuracy respectively, in predicting precisely where, when and what stages/AHA types of plaques develop along the same carotid artery. This model can generate clinically-relevant plaques with varying phenotypes fulfilling AHA classification and risk levels, in specific locations of the single artery with near 100% accuracy of prediction. The model offers a promising tool for development of diagnostic tools to target high-risk plaques, increasing accuracy in predicting which individual patients may require surgical intervention to prevent stroke, paving the way for personalized management of carotid atherosclerotic disease.

Piezo1 mediates endothelial atherogenic inflammatory responses via regulation of YAP/TAZ activation.

The vascular endothelium plays a key role in the pathobiology of atherosclerotic cardiovascular disease. Endothelial cell Piezo1 mediates blood vessel formation, angiogenesis and regulation of blood pressure. However, changes of Piezo1 expression in atherosclerosis (AS) and the role of Piezo1 in the progression of atherosclerotic diseases remains obscure. Thus, the current study is to elucidate the role and mechanism of which Piezo1 mediates vascular inflammation in atherosclerotic mice and vascular endothelial inflammation induced by oxidized low density lipoprotein (ox-LDL) in vitro. Here, we have shown that the expression of Piezo1 was significantly increased in the stenotic carotid artery of ApoE-/- mice fed by high-fat diet (HFD). Pharmacological inhibition of Piezo1 (GsMTx-4) attenuated plaque formation, decreased the level of inflammation related factors (JNK, TNF-α, NF-κB, VCAM-1) of carotid plaque in atherosclerotic mice. Meanwhile, ox-LDL also upregulates Piezo1 and inflammation proteins (NF-κB, JNK and TNF-α) in endothelium cells (ECs). YAP/TAZ is activated accompanied by the enhanced Piezo1 activity in ECs induced by ox-LDL. Interference by siRNA of Piezo1 abolished the expression of YAP/TAZ and inflammation proteins (JNK, NF-κB and TNF-α). In addition, Ca2+ influx in ECs induced by ox-LDL was increased than control group, Piezo1 siRNA can reduce the calcium content. Piezo1 agonist Yoda1 increased Ca2+ influx and promote YAP nucleus translocation in ECs, genetic deletion of Piezo1 reversed it. Our results indicate that Piezo1 could mediate endothelial atherogenic inflammatory responses via regulation of YAP/TAZ activation and nuclear localization. Piezo1 may be a potential therapeutic target for atherosclerotic diseases in the future.

S-1-Propenylcysteine promotes IL-10-induced M2c macrophage polarization through prolonged activation of IL-10R/STAT3 signaling.

Atherosclerosis is a chronic inflammatory disease that may lead to the development of serious cardiovascular diseases. Aged garlic extract (AGE) has been reported to ameliorate atherosclerosis, although its mode of action remains unclear. We found that AGE increased the mRNA or protein levels of arginase1 (Arg1), interleukin-10 (IL-10), CD206 and hypoxia-inducible factor 2α (HIF2α) and decreased that of CD68, HIF1α and inducible nitric oxide synthase in the aorta and spleen of apolipoprotein E knockout mice. We also found that S-1-propenylcysteine (S1PC), a characteristic sulfur compound in AGE, increased the level of IL-10-induced Arg1 mRNA and the extent of M2c-like macrophage polarization in vitro. In addition, S1PC increased the population of M2c-like macrophages, resulting in suppressed the population of M1-like macrophages and decreased lipopolysaccharide-induced production of pro-inflammatory cytokines. These effects were accompanied by prolonged phosphorylation of the IL-10 receptor α (IL-10Rα) and signal transducer and activator of transcription 3 (STAT3) that inhibited the interaction between IL-10Rα and Src homology-2-containing inositol 5'-phosphatase 1 (SHIP1). In addition, administration of S1PC elevated the M2c/M1 macrophage ratio in senescence-accelerated mice. These findings suggest that S1PC may help improve atherosclerosis due to its anti-inflammatory effect to promote IL-10-induced M2c macrophage polarization.

Elimination of Ox-LDL through the liver inhibits advanced atherosclerotic plaque progression.

Aim: In the late stage of atherosclerosis, the endothelial barrier of plaque is destroyed. The rapid deposition of oxidized lipids in the circulation leads to migration of numerous smooth muscle cells and macrophages, as well as foaming necrosis. The plaque progresses rapidly, and vulnerable plaques can easily induce adverse cardiovascular events. Here, we take the principle of gene editing to transfer the liver to express the LOX-1 receptor which is more sensitive to Ox-LDL by using AAV8 containing a liver-specific promoter. In this way, we want to explore whether the progress of advanced atherosclerosis and the stability of advanced plaque can be improved when the liver continues to clear Ox-LDL from the circulation. Methods and Results: In order to explore the effect of the physiological and continuous elimination of Ox-LDL through the liver on advanced atherosclerosis, we chose ApoE-/- mice in high-fat diet for 20 weeks. After 16 weeks of high-fat diet, the baseline group was sacrificed and the specimens were collected. The virus group and the control group were injected with the same amount of virus dilution and normal saline through the tail vein, and continued to feed until 20 weeks of high-fat diet, and then sacrificed to collect specimens. The results showed that LOX-1 was ectopically and functionally expressed in the liver as an Ox-LDL receptor, reducing the content of it in circulation. Compared with the control group, the degree of plaque progression in the virus group was significantly reduced, similar to the baseline group, the plaque necrosis core decreased, and the collagen fiber content increased. In addition, there are more contractile smooth muscle cells in the plaques of the virus group instead of synthetic ones, and the content of macrophages was also reduced. These data suggested that the virus group mice have greatly increased advanced plaque stability compared with the control group mice. Conclusions: Due to the destruction of endothelial barrier in advanced plaques, rapid deposition of Ox-LDL can result in fast plaque progression, increased necrotic cores, and decreased stability. Our research shows that the use of AAV8 through gene editing allows the liver to express LOX-1 receptors that are more sensitive to Ox-LDL, so that it can continue to bind Ox-LDL in the circulation and exploit the liver's strong lipid metabolism ability to physiologically clear Ox-LDL, which can inhibit the rapid progress of advanced plaque and increase the stability of plaque.

(-)-Epicatechin gallate blocks the development of atherosclerosis by regulating oxidative stress in vivo and in vitro.

(-)-Epicatechin gallate (ECG), as a compound in green tea extract polyphenols, has specific therapeutic effects against oxidative stress. Oxidative stress exists throughout the pathological development of atherosclerosis. In this study, two atherosclerosis models, oxidized low-density lipoprotein (ox-LDL)-induced vascular smooth muscle cells (VSMCs) and high fat diet (HFD)-induced ApoE-/- mice, were applied to explore the mechanism of ECG intervention on AS. In vivo and in vitro studies showed that ECG reduced the level of MDA and increased the activity of SOD, which are oxidative stress factors. ECG also improved HFD-induced disorder of lipid factor expression in the serum of ApoE-/- mice and alleviated oxidative stress by enhancing the antioxidant activity. The potential mechanism was supposed to be the inhibition of the phosphorylation of p65 by ECG in the NF-κB pathway in the aorta, thereby blocking the expression of inflammatory mediators. In addition, ECG increased the stability of atherosclerosis plaques by reducing the expression of MMP-2 and ICAM-1 in atherosclerosis diseased tissues. ECG reduced lipid accumulation in the aorta and its roots and also plaque neoplasia. Western blotting experiments indicated that ECG increased the nuclear transfer of Nrf2 and the expression of heme oxygenase 1 (HO-1) was increased. These results demonstrated that ECG significantly reduced the formation of aortic plaque in ApoE-/- mice which was possibly triggered by the inhibition of hyperlipidemia and oxidative stress that exhibited the anti-atherosclerotic potential.

Floralozone protects endothelial function in atherosclerosis by ameliorating NHE1.

Endothelial dysfunction is the pathological basis of atherosclerosis. Incomplete understanding of endothelial dysfunction etiology has impeded drug development for this devastating disease despite the currently available therapies. Floralozone, an aroma flavor, specifically exists in rabbit ear grass. Recently, floralozone has been demonstrated to inhibit atherosclerosis, but the underlying mechanisms are undefined. The present study was undertaken to explore whether floralozone pharmacologically targets endothelial dysfunction and therefore exerts therapeutic effects on atherosclerosis. The Na+/H+ exchanger 1 (NHE1), a channel protein, plays a vital role in atherosclerosis. Whether NHE1 is involved in the therapeutic effects of floralozone on endothelial dysfunction has yet to be further answered. By performing oil red staining and hematoxylin-eosin staining, vascular functional study, and oxidative stress monitoring, we found that floralozone not only reduced the size of carotid atherosclerotic plaque but also prevented endothelial dysfunction in atherosclerotic rats. NHE1 expression was upregulated in the inner membrane of carotid arteries and H2O2-induced primary rat aortic endothelial cells. Inspiringly, floralozone prevented the upregulation of NHE1 in vivo and in vitro. Notably, the administration of NHE1 activator LiCl significantly weakened the protective effect of floralozone on endothelial dysfunction in vivo and in vitro. Our study demonstrated that floralozone exerted its protective effect on endothelial dysfunction in atherosclerosis by ameliorating NHE1. NHE1 maybe a drug target for the treatment of atherosclerosis, and floralozone may be an effective drug to meet the urgent needs of atherosclerosis patients by dampening NHE1.

Colchicine for Prevention of Atherothrombotic Events in Patients With Coronary Artery Disease: Review and Practical Approach for Clinicians.

A better understanding of the central role of inflammation in the development of coronary artery disease (CAD) has been the impetus for the evaluation of therapeutic strategies targeting the interleukin-1ß/interleukin-6 cytokine signaling pathway, involved in both chronic atherogenesis and in triggering of atherosclerotic plaque rupture. As an inexpensive pharmacologic agent with relatively few adverse effects that tend to be mild and tolerable, the role of colchicine in secondary prevention of atherothrombotic events has been the focus of multiple recent large-scale randomized controlled trials involving patients with stable CAD (Low-Dose Colchicine [LoDoCo] and LoDoCo2 trials), a recent myocardial infarction (Colchicine Cardiovascular Outcome Trial [COLCOT], Colchicine in Patients With Acute Coronary Syndrome [COPS], and Colchicine and Spironolactone in Patients With Myocardial Infarction/Synergy Stent Registry [CLEAR SYNERGY] trials), and undergoing percutaneous coronary interventions (Colchicine in Percutaneous Coronary Intervention [COLCHICINE-PCI] trial). Based on this evidence, low-dose colchicine (0.5 mg once daily) should be considered in patients with recent myocardial infarctions-within 30 days and, ideally, within 3 days-or with stable CAD to improve cardiovascular outcomes. Colchicine should not be used in patients with severe renal or hepatic disease because of the risk of severe toxicity. No serious adverse effect was associated with the combined use of colchicine and high-intensity statin therapy in large trials. The impact of colchicine in high-risk populations of patients with peripheral arterial disease and in those with diabetes for the primary prevention of CAD remains to be established.

High fluid shear stress prevents atherosclerotic plaque formation by promoting endothelium denudation and synthetic phenotype of vascular smooth muscle cells.

Low blood fluid shear stress (SS) promotes vascular remodeling and atherosclerosis; however, the effects of high (H)SS on vascular remodeling and atherogenesis is not fully clarified. The major goal of this study was to investigate the role of HSS in atherosclerotic plaque formation. A perivascular SS modifier was implanted in the right carotid artery of apolipoprotein E (ApoE)­/­ mice to induce HSS, whereas the left carotid artery represented undisturbed (U)SS as a control in vivo. In vitro modeling used human umbilical vein endothelial cells and vascular smooth muscle cells exposed to HSS (2.5 Pa) using a parallel­plate flow system. The results demonstrated that there were no plaque formations or endothelial cells in the HSS regions of the carotid artery in ApoE­/­ mice. The number of umbilical vein endothelial cells was markedly decreased in a time­dependent manner in HSS. HSS significantly decreased α­smooth muscle actin and increased osteopontin protein expression levels compared with USS in vascular smooth muscle cells (P<0.05). In addition, HSS significantly increased the protein expression levels of collagen α1(XVIII) chain/endostatin and matrix metalloproteinase­8 in vascular smooth muscle cells. These data indicated that HSS may prevent atherosclerotic plaque formation through endothelium denudation and contractile­to­synthetic phenotypic conversion of smooth muscle cells.

National Heart Foundation of Australia: position statement on coronary artery calcium scoring for the primary prevention of cardiovascular disease in Australia.

INTRODUCTION: This position statement considers the evolving evidence on the use of coronary artery calcium scoring (CAC) for defining cardiovascular risk in the context of Australian practice and provides advice to health professionals regarding the use of CAC scoring in primary prevention of cardiovascular disease in Australia. Main recommendations: CAC scoring could be considered for selected people with moderate absolute cardiovascular risk, as assessed by the National Vascular Disease Prevention Alliance (NVDPA) absolute cardiovascular risk algorithm, and for whom the findings are likely to influence the intensity of risk management. (GRADE evidence certainty: Low. GRADE recommendation strength: Conditional.) CAC scoring could be considered for selected people with low absolute cardiovascular risk, as assessed by the NVDPA absolute cardiovascular risk algorithm, and who have additional risk-enhancing factors that may result in the underestimation of risk. (GRADE evidence certainty: Low. GRADE recommendation strength: Conditional.) If CAC scoring is undertaken, a CAC score of 0 AU could reclassify a person to a low absolute cardiovascular risk status, with subsequent management to be informed by patient-clinician discussion and follow contemporary recommendations for low absolute cardiovascular risk. (GRADE evidence certainty: Very low. GRADE recommendation strength: Conditional.) If CAC scoring is undertaken, a CAC score > 99 AU or ≥ 75th percentile for age and sex could reclassify a person to a high absolute cardiovascular risk status, with subsequent management to be informed by patient-clinician discussion and follow contemporary recommendations for high absolute cardiovascular risk. (GRADE evidence certainty: Very low. GRADE recommendation strength: Conditional.) CHANGES IN MANAGEMENT AS A RESULT OF THIS STATEMENT: CAC scoring can have a role in reclassification of absolute cardiovascular risk for selected patients in Australia, in conjunction with traditional absolute risk assessment and as part of a shared decision-making approach that considers the preferences and values of individual patients.

The benzoate plant metabolite ethyl gallate prevents cellular- and vascular-lipid accumulation in experimental models of atherosclerosis.

Ethyl gallate (EG) is a well-known constituent of medicinal plants, but its effects on atherosclerosis development are not clear. In the present study, the anti-atherosclerosis effects of EG and the underlying mechanisms were explored using macrophage cultures, zebrafish and apolipoprotein (apo) E deficient mice. Treatment of macrophages with EG (20 µM) enhanced cellular cholesterol efflux to HDL, and reduced net lipid accumulation in response to oxidized LDL. Secretion of monocyte chemotactic protein-1 (MCP-1) and interleukin-6 (IL-6) from activated macrophages was also blunted by EG. Fluorescence imaging techniques revealed EG feeding of zebrafish reduced vascular lipid accumulation and inflammatory responses in vivo. Similar results were obtained in apoE-/- mice 6.5 months of age, where plaque lesions and monocyte infiltration into the artery wall were reduced by 70% and 42%, respectively, after just 6 weeks of injections with EG (20 mg/kg). HDL-cholesterol increased 2-fold, serum cholesterol efflux capacity increased by ∼30%, and the levels of MCP-1 and IL-6 were reduced with EG treatment of mice. These results suggest EG impedes early atherosclerosis development by reducing the lipid and macrophage-content of plaque. Underlying mechanisms appeared to involve HDL cholesterol efflux mechanisms and suppression of pro-inflammatory cytokine secretion.

Mouse bone marrow derived mesenchymal stem cells-secreted exosomal microRNA-125b-5p suppresses atherosclerotic plaque formation via inhibiting Map4k4.

BACKGROUND: Accumulating evidence has reported the role of microRNA (miR) on atherosclerosis (AS), while it is unclear about the relationship between microRNA-125b-5p (miR-125b-5p) and AS. Thus, the object of this study was to investigate the impact of exosomal miR-125b-5p targeting mitogen-activated protein 4 kinase 4 (Map4k4) on AS plaque formation. METHODS: The AS model was established using a high fat diet in ApoE-/- mice. Mouse bone marrow-derived mesenchymal stem cells (BMSCs) were selected and BMSC-exosomes (BMSC-EXO) were extracted and then identified. The targeted relationship between miR-125b-5p and Map4k4 was tested. BMSC-EXO were modified with miR-125b-5p- and Map4k4-related sequences to interfere with AS mice. MiR-125b-5p and Map4k4 expression in AS tissues were tested. The inflammation-related indices, blood lipid, plaque area, apoptosis index, MMP-9 and α-SMA expression in mice with AS were measured. RESULTS: BMSCs and BMSC-EXO were successfully isolated. MiR-125b-5p was down-regulated and Map4k4 was up-regulated in aorta tissues from ApoE-/- mice after AS modeling, verses those from C57BL/6 mice without modeling. MiR-125b-5p targeted Map4k4. BMSC-EXO increased miR-125b-5p expression and decreased Map4k4 expression. BMSC-EXO/up-regulated miR-125b-5p and down-regulated Map4k4 in exosomes decreased inflammatory reaction, blood lipid, plaque area, MMP-9 expression and increased α-SMA expression, as well as inhibited apoptosis index of AS mice. CONCLUSION: Functional studies revealed that exosomal miR-125b-5p from BMSCs suppresses atherosclerotic plaque formation via inhibiting Map4k4 expression.

Digestive n-6 Lipid Oxidation, a Key Trigger of Vascular Dysfunction and Atherosclerosis in the Western Diet: Protective Effects of Apple Polyphenols.

SCOPE: A main risk factor of atherosclerosis is a Western diet (WD) rich in n-6 polyunsaturated fatty acids (PUFAs) sensitive to oxidation. Their oxidation can be initiated by heme iron of red meat leading to the formation of 4-hydroxy-2-nonenal (4-HNE), a cytotoxic aldehyde. An increased 4-HNE production is implicated in endothelial dysfunction and atherosclerosis. By contrast, a diet rich in proanthocyanidins reduces oxidative stress and arterial diseases. This study evaluates the effects of a WD on vascular integrity in ApolipoproteinE (ApoE-/- ) mice and the protective capacity of apple extract and puree rich in antioxidant proanthocyanidins. METHODS AND RESULTS: ApoE-/- mice are fed during 12 weeks with a WD with or without n-6 PUFAs. Moreover, two WD + n-6 PUFAs groups are supplemented with apple puree or phenolic extract. An increase in digestive 4-HNE production associated with a rise in plasmatic 4-HNE and oxidized LDL concentrations is reported. Oxidizable n-6 PUFAs consumption is associated with a worsened endothelial dysfunction and atherosclerosis. Interestingly, supplementations with apple polyphenol extract or puree prevented these impairments while reducing oxidative stress. CONCLUSION: n-6 lipid oxidation during digestion may be a key factor of vascular impairments. Nevertheless, an antioxidant strategy can limit 4-HNE formation during digestion and thus durably protect vascular function.