The role of monocytosis and neutrophilia in atherosclerosis

Neutrophils and neutrophil extracellular traps in oral health and disease

Neutrophils perform essential functions in antimicrobial defense and tissue maintenance at mucosal barriers. However, a dysregulated neutrophil response and, in particular, the excessive release of neutrophil extracellular traps (NETs) are implicated in the pathology of various diseases. In this review, we provide an overview of the basic concepts related to neutrophil functions, including NET formation, and discuss the mechanisms associated with NET activation and function in the context of the prevalent oral disease periodontitis.

Association between pan-immune-inflammation value and coronary slow flow phenomenon in patients with angiographically normal coronary arteries

INTRODUCTION

Coronary slow flow phenomenon (CSFP) is characterized by the delayed contrast filling of terminal vessels of coronary arteries in the presence of normal or nearly normal epicardial coronary arteries. Given that inflammation plays a role in cardiovascular disorders, including CSFP, using peripheral blood-derived compound prognostic indexes could be a feasible way to predict the presence of CSFP. Therefore, in the present study, we evaluated the association between pan-immune-inflammation value (PIV) and the CSFP.

METHODS

This single-center, retrospective study was composed of 612 patients aged over 18 years who underwent CAG for suspected stable ischemic heart disease. The association of clinical and laboratory parameters with the CSFP was evaluated with univariate and multivariate analyses.

RESULTS

The median age of the patients was 54 (IQR 46-63) and 61.3% of the patients were male. The 12.6% (84/612) of the patients had CSFP, while the coronary flow was normal in the remaining 87.4% of patients. The PIV levels had moderate success for the prediction of the CSFP (AUC: 0.675, 95% CI: 0.615-0.735, p < 0.001). In multivariate analyses, male gender (OR: 4.858, 95% CI: 2.851-8.277, p < 0.001), presence of diabetes (OR: 2.672, 95% CI: 1.396-5.113, p = 0.003), lower HDL-C values (OR: 2.120, 95% CI: 1.286-3.496, p = 0.003), and higher PIV levels (OR: 2.527, 95% CI: 1.519-4.203, p < 0.001) were associated with a higher risk of CSFP.

CONCLUSION

We demonstrated that a higher risk of CSFP in patients with PIV levels. If supported by prospective evidence, PIV levels could be used as a minimally invasive reflector of CSFP.

Encapsulated Streptococcus suis impairs optimal neutrophil functions which are not rescued by priming with colony-stimulating factors

The porcine pathogen and zoonotic agent Streptococcus suis induces an exacerbated inflammation in the infected hosts that leads to sepsis, meningitis, and sudden death. Several virulence factors were described for S. suis of which the capsular polysaccharide (CPS) conceals it from the immune system, and the suilysin exhibits cytotoxic activity. Although neutrophils are recruited rapidly upon S. suis infection, their microbicidal functions appear to be poorly activated against the bacteria. However, during disease, the inflammatory environment could promote neutrophil activation as mediators such as the granulocyte colony-stimulating factor granulocyte (G-CSF) and the granulocyte-macrophages colony-stimulating factor (GM-CSF) prime neutrophils and enhance their responsiveness to bacterial detection. Thus, we hypothesized that CPS and suilysin prevent an efficient activation of neutrophils by S. suis, but that G-CSF and GM-CSF rescue neutrophil activation, leading to S. suis elimination. We evaluated the functions of porcine neutrophils in vitro in response to S. suis and investigated the role of the CPS and suilysin on cell activation using isogenic mutants of the bacteria. We also studied the influence of G-CSF and GM-CSF on neutrophil response to S. suis by priming the cells with recombinant proteins. Our study confirmed that CPS prevents S. suis-induced activation of most neutrophil functions but participates in the release of neutrophil-extracellular traps (NETs). Priming with G-CSF did not influence cell activation, but GM-CSF strongly promote IL-8 release, indicating its involvement in immunomodulation. However, priming did not enhance microbicidal functions. Studying the interaction between S. suis and neutrophils-first responders in host defense-remains fundamental to understand the immunopathogenesis of the infection and to develop therapeutical strategies related to neutrophils' defense against this bacterium.

Nanomedicine for Diagnosis and Treatment of Atherosclerosis

With the changing disease spectrum, atherosclerosis has become increasingly prevalent worldwide and the associated diseases have emerged as the leading cause of death. Due to their fascinating physical, chemical, and biological characteristics, nanomaterials are regarded as a promising tool to tackle enormous challenges in medicine. The emerging discipline of nanomedicine has filled a huge application gap in the atherosclerotic field, ushering a new generation of diagnosis and treatment strategies. Herein, based on the essential pathogenic contributors of atherogenesis, as well as the distinct composition/structural characteristics, synthesis strategies, and surface design of nanoplatforms, the three major application branches (nanodiagnosis, nanotherapy, and nanotheranostic) of nanomedicine in atherosclerosis are elaborated. Then, state-of-art studies containing a sequence of representative and significant achievements are summarized in detail with an emphasis on the intrinsic interaction/relationship between nanomedicines and atherosclerosis. Particularly, attention is paid to the biosafety of nanomedicines, which aims to pave the way for future clinical translation of this burgeoning field. Finally, this comprehensive review is concluded by proposing unresolved key scientific issues and sharing the vision and expectation for the future, fully elucidating the closed loop from atherogenesis to the application paradigm of nanomedicines for advancing the early achievement of clinical applications.

HDL Function and Atherosclerosis: Reactive Dicarbonyls as Promising Targets of Therapy

Epidemiologic studies detected an inverse relationship between HDL (high-density lipoprotein) cholesterol (HDL-C) levels and atherosclerotic cardiovascular disease (ASCVD), identifying HDL-C as a major risk factor for ASCVD and suggesting atheroprotective functions of HDL. However, the role of HDL-C as a mediator of risk for ASCVD has been called into question by the failure of HDL-C-raising drugs to reduce cardiovascular events in clinical trials. Progress in understanding the heterogeneous nature of HDL particles in terms of their protein, lipid, and small RNA composition has contributed to the realization that HDL-C levels do not necessarily reflect HDL function. The most examined atheroprotective function of HDL is reverse cholesterol transport, whereby HDL removes cholesterol from plaque macrophage foam cells and delivers it to the liver for processing and excretion into bile. Indeed, in several studies, HDL has shown inverse associations between HDL cholesterol efflux capacity and ASCVD in humans. Inflammation plays a key role in the pathogenesis of atherosclerosis and vulnerable plaque formation, and a fundamental function of HDL is suppression of inflammatory signaling in macrophages and other cells. Oxidation is also a critical process to ASCVD in promoting atherogenic oxidative modifications of LDL (low-density lipoprotein) and cellular inflammation. HDL and its proteins including apoAI (apolipoprotein AI) and PON1 (paraoxonase 1) prevent cellular oxidative stress and LDL modifications. Importantly, HDL in humans with ASCVD is oxidatively modified rendering HDL dysfunctional and proinflammatory. Modification of HDL with reactive carbonyl species, such as malondialdehyde and isolevuglandins, dramatically impairs the antiatherogenic functions of HDL. Importantly, treatment of murine models of atherosclerosis with scavengers of reactive dicarbonyls improves HDL function and reduces systemic inflammation, atherosclerosis development, and features of plaque instability. Here, we discuss the HDL antiatherogenic functions in relation to oxidative modifications and the potential of reactive dicarbonyl scavengers as a therapeutic approach for ASCVD.

Antibodies in action: the role of humoral immunity in the fight against atherosclerosis

The sequestering of oxidation-modified low-density lipoprotein by macrophages results in the accumulation of fatty deposits within the walls of arteries. Necrosis of these cells causes a release of intercellular epitopes and the activation of the adaptive immune system, which we predict leads to robust autoantibody production. T cells produce cytokines that act in the plaque environment and further stimulate B cell antibody production. B cells in atherosclerosis meanwhile have a mixed role based on subclass. The current model is that B-1 cells produce protective IgM antibodies in response to oxidation-specific epitopes that work to control plaque formation, while follicular B-2 cells produce class-switched antibodies (IgG, IgA, and IgE) which exacerbate the disease. Over the course of this review, we discuss further the validation of these protective antibodies while evaluating the current dogma regarding class-switched antibodies in atherosclerosis. There are several contradictory findings regarding the involvement of class-switched antibodies in the disease. We hypothesize that this is due to antigen-specificity, and not simply isotype, being important, and that a closer evaluation of these antibodies' targets should be conducted. We propose that specific antibodies may have therapeutical potential in preventing and controlling plaque development within a clinical setting.

Zinc oxide nanoparticles synthesized using Hyssopus Officinalis L. Extract Induced oxidative stress and changes the expression of key genes involved in inflammatory and antioxidant Systems

BACKGROUND

Recent advances in the synthesis of bioactive nanoparticles resulted in the discovery and introduction of new bioactive nanoparticles to the pharmaceutical industry. In this regard, this research is aimed to synthesize the zinc oxide nanoparticles (ZnO-NPs) using Hyssopus officinalis L. extract and to evaluate the safety of nanoparticles using Balb/C mice.

METHODS

Forty male mice were divided into four groups and received 0, 50, 100, and 200 mg/kg of ZnO-NPs for thirty days. At the end of the experiment, blood sugar, creatinine, aspartate aminotransferase (A.S.T.), and alanine aminotransferase (A.L.T.) were determined. Furthermore, histopathological and oxidative stress biomarker analyses in liver and kidney tissues were performed. The changes in the major inflammatory- and antioxidant-related genes were determined.

RESULTS

The results showed that blood sugar and creatinine reduced significantly (P < 0.05) when 50, 100, and 200 mg/kg ZnO-NPs were supplemented to the diet. The serum ALT and AST and lipid peroxidation in the liver and kidney tissues were increased significantly (p < 0.05) when 50, 100, and 200 mg/kg ZnO-NPs were supplemented to the diet. Supplementation of ZnO-NPs suppressed the expression of antioxidant-related genes (SOD and CAT) and up-regulated the inflammatory biomarkers (iNOS and TNF- α). The concentration of 200 mg/Kg nanoparticles indicated cellular degeneration and necrosis in the liver and kidney tissues.

CONCLUSIONS

Overall, it can be concluded that supplementation of ZnO-NPs synthesized using Hyssopus Officinalis L. extract in this study at 50 mg/kg or higher concentrations might be toxic to the mice.

Impact of medication on blood transcriptome reveals off-target regulations of beta-blockers

Background

For many drugs, mechanisms of action with regard to desired effects and/or unwanted side effects are only incompletely understood. To investigate possible pleiotropic effects and respective molecular mechanisms, we describe here a catalogue of commonly used drugs and their impact on the blood transcriptome.

Methods and results

From a population-based cohort in Germany (LIFE-Adult), we collected genome-wide gene-expression data in whole blood using in Illumina HT12v4 micro-arrays (n = 3,378; 19,974 gene expression probes per individual). Expression profiles were correlated with the intake of active substances as assessed by participants’ medication. This resulted in a catalogue of fourteen substances that were identified as associated with differential gene expression for a total of 534 genes. As an independent replication cohort, an observational study of patients with suspected or confirmed stable coronary artery disease (CAD) or myocardial infarction (LIFE-Heart, n = 3,008, 19,966 gene expression probes per individual) was employed. Notably, we were able to replicate differential gene expression for three active substances affecting 80 genes in peripheral blood mononuclear cells (carvedilol: 25; prednisolone: 17; timolol: 38). Additionally, using gene ontology enrichment analysis, we demonstrated for timolol a significant enrichment in 23 pathways, 19 of them including either GPER1 or PDE4B. In the case of carvedilol, we showed that, beside genes with well-established association with hypertension (GPER1, PDE4B and TNFAIP3), the drug also affects genes that are only indirectly linked to hypertension due to their effects on artery walls or their role in lipid biosynthesis.

Conclusions

Our developed catalogue of blood gene expressions profiles affected by medication can be used to support both, drug repurposing and the identification of possible off-target effects.

The neutrophil percentage-to-albumin ratio is associated with all-cause mortality in critically ill patients with acute myocardial infarction

Aim

In this study, we evaluated the utility of neutrophil percentage-to-albumin ratio (NPAR) in predicting in critically ill patients with acute myocardial infarction (AMI).

Methods

The information of patients were collected from Medical Information Mart for Intensive Care III database. Admission NPAR was calculated as neutrophil percentage divided by serum albumin. The endpoints of this study were 30-day, 90-day, 180-day, and 365-day all-cause mortality. Cox proportional hazards models and subgroup analyses were used to determine the relationship between admission NPAR and these endpoints.

Results

798 critically ill patients with AMI were enrolled in. After adjustments for age, race and gender, higher admission NPAR was associated with increased risk of 30-day, 90-day, 180-day, and 365-day all-cause mortality in critically ill patients with AMI. And after adjusting for possible confounding variables, two different trends have emerged. Stratified by tertiles, high admission NPAR was independently associated with 180-day and 365-day all-cause mortality in critically ill patients with AMI (tertile 3 vs. tertile 1: adjusted HR, 95% CI 1.71, 1.10–2.66, p < 0.05; 1.66, 1.10–2.51, p < 0.05). In other hand, stratified by quartiles, highest admission NPAR levels were independently associated with 90-day, 180-day and 365-day all-cause mortality (quartile 4 vs. quartile 1: adjusted HR, 95% CI 2.36, 1.32–4.23, p < 0.05; 2.58, 1.49–4.47, p < 0.05; 2.61, 1.56–4.37, p < 0.05). ROC test showed that admission NPAR had a moderate ability to predict all-cause mortality of critically ill patients with AMI. No obvious interaction was found by subgroup analysis in most subgroups.

Conclusions

Admission NPAR was an independent predictor for 180-day and 365-day all-cause mortality in critically ill patients with AMI.

Where the Action Is-Leukocyte Recruitment in Atherosclerosis

Atherosclerosis is the leading cause of death worldwide and leukocyte recruitment is a key element of this phenomenon, thus allowing immune cells to enter the arterial wall. There, in concert with accumulating lipids, the invading leukocytes trigger a plethora of inflammatory responses which promote the influx of additional leukocytes and lead to the continued growth of atherosclerotic plaques. The recruitment process follows a precise scheme of tethering, rolling, firm arrest, crawling and transmigration and involves multiple cellular and subcellular players. This review aims to provide a comprehensive up-to-date insight into the process of leukocyte recruitment relevant to atherosclerosis, each from the perspective of endothelial cells, monocytes and macrophages, neutrophils, T lymphocytes and platelets. In addition, therapeutic options targeting leukocyte recruitment into atherosclerotic lesions-or potentially arising from the growing body of insights into its precise mechanisms-are highlighted.

Associations of Monocytes and the Monocyte/High-Density Lipoprotein Ratio With Extracranial and Intracranial Atherosclerotic Stenosis

Background: Although the monocyte/high-density lipoprotein ratio (MHR) has been shown to be a potential marker of inflammatory of cardiovascular and cerebrovascular diseases, there are few studies on its relationships with the degree of intracranial and extracranial atherosclerotic stenosis and the stenosis distribution.

Methods: In total, 271 patients were admitted for digital subtraction angiography (DSA) examination and were classified into a non-stenosis group and a stenosis group. (1) The two groups were compared and the arteries were categorized according to the degree of intracranial or extracranial atherosclerotic stenosis (if ≥two branches were stenotic, the artery with the most severe stenosis was used). (2) Clinical baseline data and laboratory indexes of patients grouped according to stenosis location (intracranial vs. extracranial) were collected.

Results: (1) MHR × 10² [odds ratio (OR) = 1.119, p < 0.001], age (OR = 1.057, p = 0.007), and lymphocyte count (OR = 0.273, p = 0.002) significantly affected the presence of cerebral atherosclerotic stenosis, with an MHR area of 0.82 under the receiver operating characteristic (ROC) curve (AUC) and an optimal diagnostic value of 0.486. Analyses of the moderate, mild, and severe stenosis groups showed that MHR × 10² (OR = 1.07, p < 0.001) significantly affected the severity of stenosis in patients. (2) In the analysis of stenosis at different sites, the rate of extracranial artery stenosis in patients who smoked (OR = 3.86, p = 0.023) and had a reduced lymphocyte level (OR = 0.202, p = 0.001) was remarkably greater than that in patients who smoked (OR = 3.86, p = 0.023). With increasing age, the rate of extracranial artery stenosis raised sharply. With the increase in the MHR level, the stenosis rate of each group was highly greater than that of the non-stenosis group.

Conclusion: The MHR has a predictive value for the diagnosis of extracranial and intracranial atherosclerotic stenosis and is correlated with the degree and distribution of stenosis.

Trial Registration: Clinical Medical Research Center Project of Qinghai Province (2017-SF-L1). Qinghai Provincial Health Commission Project (Grant #2020-wjzdx-29).

New Horizons for the Roles and Association of APE1/Ref-1 and ABCA1 in Atherosclerosis

Atherosclerosis is the leading cause of death worldwide. APE1/Ref-1 and ABCA1 play key roles in the progression of atherosclerosis. APE1/Ref-1 suppresses atherosclerosis via multiple mechanisms, including reducing the IL-6-, TNF-α-, and IL-1β-mediated proinflammatory responses, suppressing ROS-mediated oxidant activity and Bax/Bcl-2-mediated vascular calcification and apoptosis, and reducing LOX-1-mediated cholesterol uptake. However, APE1/Ref-1 also promotes atherosclerosis by increasing the activity of the NK-κB and S1PR1 pathways. APE1/Ref-1 localizes to the nucleus, cytoplasm, and mitochondria and can be secreted from the cell. APE1/Ref-1 localization is dynamically regulated by the disease state and may be responsible for its proatherogenic and antiatherogenic effects. ABCA1 promotes cholesterol efflux and anti-inflammatory responses by binding to apoA-I and regulates apoptotic cell clearance and HSPC proliferation to protect against inflammatory responses. Interestingly, in addition to mediating these functions, ABCA1 promotes the secretion of acetylated APE1/Ref-1 (AcAPE1/Ref-1), a therapeutic target, which protects against atherosclerosis development. The APE1/Ref-1 inhibitor APX3330 is being evaluated in a phase II clinical trial. The LXR agonist LXR-623 (WAY-252623) is an agonist of ABCA1 and the first LXR-targeting compound to be evaluated in clinical trials. In this article, we review the roles of ABCA1 and APE1/Ref-1 in atherosclerosis and focus on new insights into the ABCA1-APE1/Ref-1 axis and its potential as a novel therapeutic target in atherosclerosis.

Urotensin II levels in patients with inflammatory bowel disease

BACKGROUND

Patients with inflammatory bowel disease (IBD) are associated with increased cardiovascular risk and have increased overall cardiovascular burden. On the other hand, urotensin II (UII) is one of the most potent vascular constrictors with immunomodulatory effect that is connected with a number of different cardiometabolic disorders as well. Furthermore, patients with ulcerative colitis have shown increased expression of urotensin II receptor in comparison to healthy controls. Since the features of IBD includes chronic inflammation and endothelial dysfunction as well, it is plausible to assume that there is connection between increased cardiac risk in IBD and UII.

AIM

To determine serum UII levels in patients with IBD and to compare them to control subjects, as well as investigate possible associations with relevant clinical and biochemical parameters.

METHODS

This cross sectional study consecutively enrolled 50 adult IBD patients (26 with Crohn’s disease and 24 with ulcerative colitis) and 50 age and gender matched controls. Clinical assessment was performed by the same experienced gastroenterologist according to the latest guidelines. Ulcerative Colitis Endoscopic Index of Severity and Simple Endoscopic Score for Crohn’s Disease were used for endoscopic evaluation. Serum levels of UII were determined using the enzyme immunoassay kit for human UII, according to the manufacturer’s instructions.

RESULTS

IBD patients have significantly higher concentrations of UII when compared to control subjects (7.57 ± 1.41 vs 1.98 ± 0.69 ng/mL, P < 0.001), while there were no significant differences between Crohn’s disease and ulcerative colitis patients (7.49 ± 1.42 vs 7.65 ± 1.41 ng/mL, P = 0.689). There was a significant positive correlation between serum UII levels and high sensitivity C reactive peptide levels (r = 0.491, P < 0.001) and a significant negative correlation between serum UII levels and total proteins (r = -0.306, P = 0.032). Additionally, there was a significant positive correlation between serum UII levels with both systolic (r = 0.387, P = 0.005) and diastolic (r = 0.352, P = 0.012) blood pressure. Moreover, serum UII levels had a significant positive correlation with Ulcerative Colitis Endoscopic Index of Severity (r = 0.425, P = 0.048) and Simple Endoscopic Score for Crohn’s Disease (r = 0.466, P = 0.028) scores. Multiple linear regression analysis showed that serum UII levels retained significant association with high sensitivity C reactive peptide (β ± standard error, 0.262 ± 0.076, P < 0.001) and systolic blood pressure (0.040 ± 0.017, P = 0.030).

CONCLUSION

It is possible that UII is involved in the complex pathophysiology of cardiovascular complications in IBD patients, and its purpose should be investigated in further studies.

Accuracy of neutrophil to lymphocyte and monocyte to lymphocyte ratios as new inflammatory markers in acute coronary syndrome

Background

Inflammation plays a key role in the development of atherosclerosis and in the pathogenesis of acute coronary syndrome (ACS). Leukocytes and leukocytes ratios were recognized as inflammatory markers in predicting the presence and severity of ACS.

Methods

This study aimed to investigate the diagnostic accuracy of neutrophil to lymphocyte ratio (NLR) and monocyte to lymphocyte ratio (MLR) with ACS. One hundred patients admitted to the Cardiac Center who were confirmed to have ACS and 100 healthy controls confirmed not to have ACS were enrolled in this study. ECG and troponin I test were used as gold standards to make sure that the participants with or without ACS. Total white blood cells (WBCs) count, NLR, and MLR values were estimated.

Results

Total WBCs, neutrophil, and monocyte counts were significantly higher while lymphocyte counts were significantly lower in ACS patients than in the healthy controls (p < 0.001). NLR and MLR were significantly higher in ACS patients than in the healthy controls (p < 0.001). Among all the studied markers, NLR was found to be the strongest predictive marker of ACS (OR: 3.3, p < 0.001), whereas MLR was non-significant (p > 0.05). A cut-off value of 2.9 of NLR had 90% sensitivity and 88% specificity while 0.375 cut-off value of MLR had 79% sensitivity, 91% specificity for predicting ACS presence.

Conclusions

NLR is a simple, widely available, and inexpensive inflammatory marker which can be an auxiliary biomarker in the diagnosis of ACS with a cut-off value of 2.9 in our population.

Irisin in atherosclerosis

Irisin, a novel exercise-induced myokine, has been shown to play important roles in increasing white adipose tissue browning, regulating energy metabolism and improving insulin resistance. Growing evidence suggests a direct role for irisin in preventing atherosclerosis (AS) by inhibiting oxidative stress, improving dyslipidemia, facilitating anti-inflammation, reducing cellular damage and recovering endothelial function. In addition, some studies have noted that serum irisin levels play an essential role in cardiovascular diseases (CVDs) risk prediction, highlighting that irisin has the potential to be a useful predictive marker and therapeutic target of AS, especially in monitoring therapeutic efficacy. This review summarizes the understanding of irisin-mediated regulation in essential biological pathways and functions in atherosclerosis and prompts further exploitation of the biological properties of irisin in the pathogenesis of atherosclerosis.

MUFAs in High-Fat Diets Protect against Obesity-Induced Bias of Hematopoietic Cell Lineages

SCOPE

The role of dietary fatty acids in the generation of bone marrow (BM) immune cells and their trafficking to extramedullary compartments in the obesity is not yet fully understood.

METHODS AND RESULTS

C57BL/6J mice are randomly assigned to isocaloric high-fat diets (HFDs) formulate with dietary fats rich in saturated fatty acids (SFAs), monounsaturated fatty acids (MUFAs) or MUFAs fortified with eicosapentaenoic and docosahexaenoic acids for 20 weeks, followed by profiling of the obese metabolic phenotype and immunophenotypic features of immune cells in blood, spleen, and BM. All HFDs induce an obese phenotype, but it becomes largely less disruptive after the HFDs are enriched in MUFAs, which also induce signs of granulopoiesis and an expansion of long-term hematopoietic stem and granulocyte-macrophage progenitor cells in BM. In contrast, a HFD enriched in SFAs disturbs the fitness of medullary lymphocytes and promotes monopoiesis in favor of pro-inflammatory activated subsets.

CONCLUSION

The reshaping of the fatty acid pools with MUFAs from the diet serves to manipulate the generation and trafficking of immune cells that are biased during obesity. These findings reveal a novel strategy by which dietary MUFAs may be instrumental in combating HFD-induced dysfunctional immune systems.

Cross-Talk of Atherosclerosis and Ischemic Stroke: Dramatic Role of Neutrophils

Context: Current investigations illustrate the increasing prevalence of atherosclerosis (AS) through the aggravating role of inappropriate lifestyle patterns. Atherosclerosis is the cause of important vascular-related diseases such as ischemic stroke (IS). Understanding AS pathophysiology can help reduce the incidence of AS-mediated diseases like ischemic stroke. Evidence Acquisition: For this narrative review article, we used the five mega databases of PubMed, Google Scholar, Scopus, Springer, and Science Direct. We searched from 2010 Jan to 2020 Dec and based on keywords and inclusion criteria, 77 articles were enrolled. Results: Based on prior articles on atherosclerosis and ischemic stroke pathophysiology, local and systemic inflammation is a vigorous factor in both diseasesIndeed, the fundamental inflammatory pathway involved atherosclerosis, and ischemic stroke is associated with the toll-like receptor 4/myeloid differentiation primary response 88/nuclear factor-kappa B (TLR4/ Myd88/ NF-κB) cascade. The functional paw of these intricate mechanisms are pro-inflammatory mediators, such as interleukin-1 beta (IL-1β), tumor necrosis factor (TNF-α), and interleukin-18 (IL-18) incite inflammation. Besides, the essential structures termed inflammasomes (multi proteins components), and multiplicity of immune and non-immune cells (i.e., neutrophils, monocytes, platelets, and macrophages) are beneficial in the induction of inflammatory microenvironment. Conclusions: Neutrophils could be the most effective cells in the inflammation-based mechanism in IS and AS. It is clarified that neutrophils with the recruitment of own vesicles and granules can afford to amplify inflammatory conditions and be a key cell in AS and IS cross-talk. Therefore, utilizing methods to control neutrophils-mediated mechanisms could be an effective method for the prevention of AS and IS.

Zebrafish Model for Screening Antiatherosclerosis Drugs

This study is aimed at establishing a zebrafish model of AS, which can be applied for high-throughput screening anti-AS drugs. A zebrafish AS model was induced by high cholesterol diet (HCD) and lipopolysaccharide (LPS). In the early stage of modeling, HCD induced zebrafish to show some early symptoms similar to human AS, mainly cholesterol accumulation, vascular inflammation, lipid metabolism disorder, and oxidative stress. In addition to lipid metabolism disorders, LPS also induced the same symptoms. And when HCD and LPS exist at the same time, these AS symptoms in zebrafish become more severe. When the modeling time reached 45 days, HCD and LPS induce the formation of plaques in zebrafish blood vessels, and these plaques contain fibrous tissue and lipids, which are similar to human AS plaques. We also evaluated the efficacy of some anti-AS drugs (atorvastatin, aspirin, and vitamin C) through these zebrafish AS models. The results found that atorvastatin can significantly reduce the symptoms of AS induced by HCD and LPS, and aspirin and vitamins can significantly reduce the symptoms of AS induced by LPS. It is feasible to use zebrafish to establish an AS model, and the zebrafish AS model can be used for high-throughput screening of anti-AS drugs.

Chronic radiation exposure aggravates atherosclerosis by stimulating neutrophil infiltration

BACKGROUND

Radiation exposure is known to increase the risk of chronic inflammatory diseases, such as atherosclerosis, by modulating inflammation.

METHODS

To investigate the infiltration of leukocytes in radiation-aggravated atherosclerosis, we examined low-density lipoprotein receptor-deficient (Ldlr-/-) mice and C57BL/6j mice after exposure to 0.5 or 1 Gy radiation over 16 weeks.

RESULTS

We found that radiation exposure induced atherosclerosis development in Ldlr-/- mice, as demonstrated by increased lipid-laden plaque size, reactive oxygen species levels, and levels of the pro-inflammatory cytokines, IL-1β and TNF-α, in the aortas and spleens. Total plasma cholesterol, triglyceride, and LDL cholesterol levels were also increased by radiation exposure, along with cardiovascular risk. We also showed dose-dependent increases in neutrophils and monocytes that coincided with a reduction in lymphocytes in the spleens of Ldlr-/- mice. The correlation between the infiltration of leukocytes and cytokine production was also confirmed in the hearts and spleens of these mice.

CONCLUSIONS

We concluded that chronic radiation exposure increased the production of pro-inflammatory mediators, which was associated with the migration of neutrophils and inflammatory monocytes into sites of atherosclerosis. Thus, our data suggest that the accumulation of neutrophils and inflammatory monocytes, together with the reduction of lymphocytes, contribute to aggravated atherosclerosis in Ldlr-/- mice under prolonged exposure to radiation.

Associations between Hypertriglyceridemia and Circulating Neutrophil Subpopulation in Patients with Dyslipidemia

Background

There is strong evidence to suggest that the negative influence of triglyceride-rich lipoproteins (TRLs) on atherosclerosis development and progression is at least partially mediated by their proinflammatory effects. However, the effect of hypertriglyceridemia (HTG) on the subpopulation composition of circulating neutrophils has not been studied so far. The aim of this study was to examine correlations between the level of triglycerides (TGs) and the subpopulation composition of circulating neutrophils in middle-aged patients with dyslipidemia without established atherosclerotic cardiovascular diseases (ASCVDs).

Methods

Ninety-one patients with dyslipidemia, including 22 (24.2%) patients with HTG, were enrolled in the study. Phenotying of neutrophil subpopulations was performed through flow cytometry (Navios 6/2, Beckman Coulter, USA). For phenotyping of neutrophil subpopulations, conjugated monoclonal antibodies were used: CD16, PE-Cyanine7 (Invitrogen, USA); CD11b-FITC (Beckman Coulter, USA); CD62L-PE (Beckman Coulter, USA); and CD184 (CXCR4)-PE-CF594 (BD Biosciences, USA).

Results

Following the correlation analysis, the TG level directly correlated with the number of circulating leukocytes (r = 0.443; p < 0.0001) and neutrophils (r = 0.311; p=0.008). HTG patients displayed a significantly high number of circulating neutrophils with CD16^hiCD11b^hiCD62L^hi and CD16^hiCD11b^loCD62L^br phenotypes. TG levels directly correlated with the number of circulating neutrophils having CD16^hiCD11b^hiCD62L^hi and CD16^hiCD11b^loCD62L^br phenotypes. Following the linear regression analysis, statistically significant correlations between TG levels and neutrophil subpopulations having CD16^hiCD11b^loCD62L^br and CD16^hiCD11b^brCD62L^loCXCR4^hi phenotypes were established. Changes in TG levels could explain up to 19.1% of the variability in the number of studied neutrophil subpopulations.

Conclusion

Among middle-aged patients without established ASCVDs, patients with HTG demonstrated a significantly higher overall number of neutrophils and neutrophils having CD16^hiCD11b^hiCD62L^hi (mature neutrophils) and CD16^hiCD11b^loCD62L^br (immunosuppressive neutrophils) than patients with normal TG levels. The TG level was associated with an increase in the number of CD16^hiCD11b^loCD62L^br and CD16^hiCD11b^brCD62L^loCXCR4^hi (ageing neutrophils) neutrophils, adjusted for the sex and age of the patients.

Targeting inflammation-associated AMPK//Mfn-2/MAPKs signaling pathways by baicalein exerts anti-atherosclerotic action

Inflammatory responses in macrophages, endothelial cells, and vascular smooth muscle cells play crucial roles in the development of atherosclerosis. Baicalein, a flavonoid phytochemical, possesses anti-inflammatory properties, but the underlying mechanisms of its action are not fully understood. The aim of this study was to explore whether baicalein inhibited inflammatory activities in RAW264.7, HUVEC, and MOVAS cells and to analyze its underlying mechanisms. Our results showed that baicalein treatment effectively reduced the levels of IL-6, TNF-α, PAI-1, and MMP-9 released by these cells upon stimulation with Ang II or ox-LDL. We discovered that the molecular mechanisms underlying baicalein suppression of the generation of proinflammatory cytokines were associated with the inhibition of MAPK/NF-κB pathway activity. Moreover, Ang II and ox-LDL intervention decreased the content of Mfn-2 in the three types of cells, but incubation of baicalein alleviated the Ang II/ox-LDL-induced reduction of Mfn-2 levels. Adv-Mfn2 treatment not only increased the expression of Mfn-2 but also reduced the levels of phosphorylated ERK1/2, p38, JNK, and NF-κB, followed by a decrease in the concentrations of IL-6, TNF-α, PAI-1, and MMP-9 in the supernatant. Furthermore, our findings indicated that baicalein treatment markedly suppressed the decrease in AMPK activity induced with Ang II and ox-LDL, and incubation with Compound C reversed the effects of baicalein on AMPK activation and Mfn-2 expression. In conclusion, our data suggest that baicalein shows anti-inflammatory properties, probably by activating the AMPK/Mfn-2 axis, accompanied by inhibition of downstream MAPKs/NF-κB signaling transduction.

The effect of coronary slow flow on left atrial structure and function

The coronary slow flow phenomenon (CSFP) is common in coronary angiography, however its impact on left atrial (LA) function is still controversial. This study aims to evaluate the LA structure and function of patients with CSFP using two-dimensional speckle tracking echocardiography (2D-STE). Consecutive patients scheduled for coronary angiography from January 2016 to September 2017 were enrolled in this study. Patients’ demographic data, clinical histories, laboratory and angiographic findings were collected and recorded. Diagnostic criteria for CSFP is based on Beltrame et al. proposed in 2012. Meanwhile 139 patients who have no significant stenosis (≤ 40%) and normal blood flow were selected as control. All patients received an echocardiographic examination 24 h before coronary angiography. LA structure and function were measured with echocardiography and 2D-STE. Our results showed that among the 1,954 patients who had received coronary angiography, 512 patients were included in the analysis after the exclusion criteria was implemented. Of those, 101 patients met the CSFP criteria (5.5%). CSFP is mainly seen in LAD (~ 70%). There was no statistical difference in baseline characteristics between the CSFP group and control group, except for a higher proportion of smokers in the CSFP group (P = 0.001). The percentage of monocytes is an independent risk factor for the occurrence of CSFP (P = 0.036) after binary logistic regression analysis. The LA global longitudinal strain (LA-GLS, represents reservoir functions) decreased and LA strain rate at late diastole (LA-SRa, represents booster function) increased in patients with CSFP compared to the control group (P < 0.05). Correlation test of continuous variables by Pearson test suggested that LA-GLS was negatively correlated with TIMI frame count (TFC). We concluded that the percentage of monocytes is an independent risk factor for the CSFP; the LA reservoir and booster functions were impaired in patients with CSFP; LA-GLS is negatively correlated with TFC.

Activating transcription factor 3 is a potential target and a new biomarker for the prognosis of atherosclerosis

ATF3 (activating transcription factor 3) is a member of the mammalian activation transcription factor/cAMP-responsive element-binding (CREB) family. It plays a role in inflammation and innate immunity, and suggests that ATF3 is associated with atherosclerosis. In our study, we analyzed datasets of atherosclerosis from the NCBI-GEO (Gene Expression Omnibus) database and found that expression levels of ATF3 were lower in macrophages from ruptured atherosclerotic plaques than from stable atherosclerotic plaques. Expression levels of ATF3 correlated with the stability of atherosclerotic plaques. KEGG analysis of different expression genes (DEGs) between ruptured and stable atherosclerotic plaques was performed by Metascape database. The PI3K-AKT pathway may be a potential pathway of the formation of ruptured atherosclerotic plaques. High-fat diet-induced atherosclerosis apoE-/- mice were divided into two groups: a model group and an ATF3 overexpression (OE)-group. Tests on atherosclerotic plaques in the aortic root suggested that absence of ATF3 and increase of macrophages may be risk factors for the formation of ruptured atherosclerotic plaques. We found decreased areas of lesions in aortic roots and branches of aortic arch, as well as increased lesional content of macrophages as well as TUNEL-positive areas. Consistent with these results, we found reduced degradation and incidence of elastic plate cracks accompanied by suppressed MMPs expression and transduction pathway protein PI3K/AKT activation. These data suggest that ATF3 is a signaling molecule that mediates the progression and stability of atherosclerotic plaques. ATF3 could be a potential new biomarker for the prognosis of atherosclerosis and may be a therapeutic target to reduce atherosclerosis.

Elevated White Blood Cell Count Resultant Atherogenesis is Associated With Panoramic-Imaged Carotid Plaque

PURPOSE

Atherosclerotic plaques develop as a result of a low-grade, chronic, systemic inflammatory response to the injury of endothelial cells arising from lipid deposition within the intima. Increased white blood cell count (WBCC) is both a validated "biologic marker" of the extent of this inflammatory process and a key participant in the development of subsequent atherosclerotic ischemic heart disease manifesting as myocardial infarction. We sought to determine if calcified carotid artery plaque (CCAP) on a panoramic image (PI), also a validated risk indicator of future myocardial infarction, is associated with increased WBCC.

PATIENTS AND METHODS

We retrospectively evaluated the PI and medical records of White male military veterans aged 55 years and older treated by a VA dental service. Established were 2 cohorts of patients, 50 having plaques (CCAP+) and 50 without plaques (CCAP-). Predictor variable was CCAP+; outcome variable was WBCC. Bootstrapping analysis determined the differences in mean WBCCs between groups. Statistical significance set at ≤ 0.05.

RESULTS

The study group, (mean age 74; range 59 to 91 years) demonstrated a mean WBCC of 8,062 per mm³. The control group, (mean age 72 range; 57 to 94) evidenced a mean WBCC of 7,058 per mm³. Bootstrapping analysis of WBCC values demonstrated a significant (P = .012) difference (95% confidence interval of difference of mean, -806, 742; observed effect size, 1004) between groups.

CONCLUSIONS

The presence of CCAP demonstrated on PIs of older Caucasian men is associated with elevated WBCC. Concomitant presence of CCAP on PI and increased WBCC (≥7,800 per mm³) amplifies need for medical consultation before intravenous anesthesia and maxillofacial surgical procedures.

Contribution of Extramedullary Hematopoiesis to Atherosclerosis. The Spleen as a Neglected Hub of Inflammatory Cells

Cardiovascular diseases (CVDs) incidence is becoming higher. This fact is promoted by metabolic disorders such as obesity, and aging. Atherosclerosis is the underlying cause of most of these pathologies. It is a chronic inflammatory disease that begins with the progressive accumulation of lipids and fibrotic materials in the blood-vessel wall, which leads to massive leukocyte recruitment. Rupture of the fibrous cap of the atherogenic cusps is responsible for tissue ischemic events, among them myocardial infarction. Extramedullary hematopoiesis (EMH), or blood cell production outside the bone marrow (BM), occurs when the normal production of these cells is impaired (chronic hematological and genetic disorders, leukemia, etc.) or is altered by metabolic disorders, such as hypercholesterolemia, or after myocardial infarction. Recent studies indicate that the main EMH tissues (spleen, liver, adipose and lymph nodes) complement the hematopoietic function of the BM, producing circulating inflammatory cells that infiltrate into the atheroma. Indeed, the spleen, which is a secondary lymphopoietic organ with high metabolic activity, contains a reservoir of myeloid progenitors and monocytes, constituting an important source of inflammatory cells to the atherosclerotic lesion. Furthermore, the spleen also plays an important role in lipid homeostasis and immune-cell selection. Interestingly, clinical evidence from splenectomized subjects shows that they are more susceptible to developing pathologies, such as dyslipidemia and atherosclerosis due to the loss of immune selection. Although CVDs represent the leading cause of death worldwide, the mechanisms involving the spleen-atherosclerosis-heart axis cross-talk remain poorly characterized.

Neutrophil Extracellular Traps: Signaling Properties and Disease Relevance

Neutrophil extracellular traps (NETs) are characterized as extracellular DNA fibers comprised of histone and cytoplasmic granule proteins. NETs were first described as a form of innate response against pathogen invasion, which can capture pathogens, degrade bacterial toxic factors, and kill bacteria. Additionally, NETs also provide a scaffold for protein and cell binding. Protein binding to NETs further activate the coagulation system which participates in thrombosis. In addition, NETs also can damage the tissues due to the proteins they carry. Many studies have suggested that the excessive formation of NETs may contribute to a range of diseases, including thrombosis, atherosclerosis, autoimmune diseases, and sepsis. In this review, we describe the structure and components of NETs, models of NET formation, and detection methods. We also discuss the molecular mechanism of NET formation and their disease relevance. Modulation of NET formation may provide a new route for the prevention and treatment of releated human diseases.

Deciphering Macrophage Phenotypes upon Lipid Uptake and Atherosclerosis

In the progression of atherosclerosis, macrophages are the key immune cells for foam cell formation. During hyperlipidemic condition, phagocytic cells such as monocytes and macrophages uptake oxidized low-density lipoproteins (oxLDLs) accumulated in subintimal space, and lipid droplets are accumulated in their cytosols. In this review, we discussed the characteristics and phenotypic changes of macrophages in atherosclerosis and the effect of cytosolic lipid accumulation on macrophage phenotype. Due to macrophage plasticity, the inflammatory phenotypes triggered by oxLDL can be re-programmed by cytosolic lipid accumulation, showing downregulation of NF-κB activation followed by activation of anti-inflammatory genes, leading to tissue repair and homeostasis. We also discuss about various in vivo and in vitro models for atherosclerosis research and next generation sequencing technologies for foam cell gene expression profiling. Analysis of the phenotypic changes of macrophages during the progression of atherosclerosis with adequate approach may lead to exact understandings of the cellular mechanisms and hint therapeutic targets for the treatment of atherosclerosis.

Medicinal Plants as a Potential and Successful Treatment Option in the Context of Atherosclerosis

Atherosclerosis is a chronic multifactorial disease characterized by mainly changes of blood lipids profile and inflammation in vessel wall. The cardiovascular disease based on atherosclerosis is currently the leading cause of mortality in developed countries. Therefore, timely prevention and therapy of atherosclerosis are able to reduce the risk of the development of its clinical manifestations. Anti-atherosclerotic activity of medicinal plants mainly appears in their multiple effects such as anti-inflammatory, antioxidant, anti-atherogenic, hypotensive, lipid-lowering, anti-thrombotic. Moreover, most of medicinal plants are characterized by their pleiotropic anti-atherosclerotic action. In addition, the medicinal plants-derived pharmacological substances and/or compounds are characterized by relative safety and fewer side effects that allows considering them as one of potential anti-atherosclerotic effective agents. The direct anti-atherosclerotic effect of some medicinal plants was confirmed in clinical trials of carotid Intima-media thickness (IMT) progression during long-term medication with medicinal plants. This review attempted to determine the current status of the databases PubMed and Scopus (until November, 2019) to investigate the medicinal plants possessing anti-atherosclerotic activity in experimental and clinical studies.

Therapeutic targeting of neutrophil exocytosis

Dysregulation of neutrophil activation causes disease in humans. Neither global inhibition of neutrophil functions nor neutrophil depletion provides safe and/or effective therapeutic approaches. The role of neutrophil granule exocytosis in multiple steps leading to recruitment and cell injury led each of our laboratories to develop molecular inhibitors that interfere with specific molecular regulators of secretion. This review summarizes neutrophil granule formation and contents, the role granule cargo plays in neutrophil functional responses and neutrophil-mediated diseases, and the mechanisms of granule release that provide the rationale for development of our exocytosis inhibitors. We present evidence for the inhibition of granule exocytosis in vitro and in vivo by those inhibitors and summarize animal data indicating that inhibition of neutrophil exocytosis is a viable therapeutic strategy.

Olmesartan alleviates bleomycin-mediated vascular smooth muscle cell senescence via the miR-665/SDC1 axis

Olmesartan (OMST) is a new angiotensin II receptor antagonist recently approved by the FDA to treat cardiovascular diseases. We investigated the molecular mechanisms by which OMST regulates vascular senescence. In the present study, bleomycin (BLM) was used to induce senescence in vascular smooth muscle cells (VSMCs); after which, the cells were treated with OMST. The effects of OMST on BLM-mediated cell senescence were evaluated using cell adhesion, NAD⁺/NADH, and Annevin V/PI double staining assays, as well as by immunofluorescence staining of γH2AX, Edu flow cytometry, and evaluations of senescence-associated β-gal activity. Differentially expressed microRNAs (DEMs) were identified by miRNA microarray assays, and subsequently validated by quantitative real time PCR. Bisulfite sequencing PCR (BSP) was used to detect the methylation status of the miR-665 promoter. The target genes of miR-665 were predicted and confirmed using luciferase reporter assays. We found that miR-665 was upregulated in VSMCs in response to BLM-induced cellular senescence. BSP studies revealed that CpG sites in the promoter region of the miR-665 gene underwent extensive demethylation during BLM-induced cellular senescence, and there was a concomitant up-regulation of miR-665 expression. SDC1 mRNA was identified as a direct target of miR-665. Either miR-665 overexpression or SDC1 knockdown significantly reversed the effects of OMST on BLM-induced VSMC senescence. Moreover, SDC1 overexpression partially reversed the changes that occurred in cells with BLM-induced senescence caused by miR-665 overexpression. Our findings suggest that the miR-665/SDC1 axis functions as a vital modulator of VSMC senescence, and may represent a novel biological target for treating atherosclerosis.

Low human and murine Mcl-1 expression leads to a pro-apoptotic plaque phenotype enriched in giant-cells

The anti-apoptotic protein myeloid cell leukemia 1 (Mcl-1) plays an important role in survival and differentiation of leukocytes, more specifically of neutrophils. Here, we investigated the impact of myeloid Mcl-1 deletion in atherosclerosis. Western type diet fed LDL receptor-deficient mice were transplanted with either wild-type (WT) or LysMCre Mcl-1^fl/fl (Mcl-1^−/−) bone marrow. Mcl-1 myeloid deletion resulted in enhanced apoptosis and lipid accumulation in atherosclerotic plaques. In vitro, Mcl-1 deficient macrophages also showed increased lipid accumulation, resulting in increased sensitivity to lipid-induced cell death. However, plaque size, necrotic core and macrophage content were similar in Mcl-1^−/− compared to WT mice, most likely due to decreased circulating and plaque-residing neutrophils. Interestingly, Mcl-1^−/− peritoneal foam cells formed up to 45% more multinucleated giant cells (MGCs) in vitro compared to WT, which concurred with an increased MGC presence in atherosclerotic lesions of Mcl-1^−/− mice. Moreover, analysis of human unstable atherosclerotic lesions also revealed a significant inverse correlation between MGC lesion content and Mcl-1 gene expression, coinciding with the mouse data. Taken together, these findings suggest that myeloid Mcl-1 deletion leads to a more apoptotic, lipid and MGC-enriched phenotype. These potentially pro-atherogenic effects are however counteracted by neutropenia in circulation and plaque.

Role of Inflammatory Cell Subtypes in Heart Failure

Inflammation is a well-known feature of heart failure. Studies have shown that while some inflammation is required for repair during injury and is protective, prolonged inflammation leads to myocardial remodeling and apoptosis of cardiac myocytes. Various types of immune cells are implicated in myocardial inflammation and include neutrophils, macrophages, eosinophils, mast cells, natural killer cells, T cells, and B cells. Recent clinical trials have targeted inflammatory cascades as therapy for heart failure with limited success. A better understanding of the temporal course of the infiltration of the different immune cells and their contribution to the inflammatory process may improve the success for therapy. This brief review outlines the major cell types involved in heart failure, and some of their actions are summarized in the supplementary figure.

Modulation of Bone and Marrow Niche by Cholesterol

Bone is a complex tissue composing of mineralized bone, bone cells, hematopoietic cells, marrow adipocytes, and supportive stromal cells. The homeostasis of bone and marrow niche is dynamically regulated by nutrients. The positive correlation between cardiovascular disease and osteoporosis risk suggests a close relationship between hyperlipidemia and/or hypercholesterolemia and the bone metabolism. Cholesterol and its metabolites influence the bone homeostasis through modulating the differentiation and activation of osteoblasts and osteoclasts. The effects of cholesterol on hematopoietic stem cells, including proliferation, migration, and differentiation, are also well-documented and further relate to atherosclerotic lesions. Correlation between circulating cholesterol and bone marrow adipocytes remains elusive, which seems opposite to its effects on osteoblasts. Epidemiological evidence has demonstrated that cholesterol deteriorates or benefits bone metabolism depending on the types, such as low-density lipoprotein (LDL) or high-density lipoprotein (HDL) cholesterol. In this review, we will summarize the latest progress of how cholesterol regulates bone metabolism and bone marrow microenvironment, including the hematopoiesis and marrow adiposity. Elucidation of these association and factors is of great importance in developing therapeutic options for bone related diseases under hypercholesterolemic conditions.

Silencing of junctional adhesion molecule-like protein attenuates atherogenesis and enhances plaque stability in ApoE-/- mice

Background: Although junctional adhesion molecule-like protein (JAML) has recently been implicated in leukocyte recruitment during inflammation and wound repair, its role in atherosclerosis remains to be elucidated. Methods and results: First, we showed that JAML was strongly expressed in atherosclerotic plaques of cardiovascular patients. Similar results were obtained with atherosclerotic plaques of ApoE^-/- mice. Co-immunofluorescence staining showed that JAML was mainly expressed in macrophages. Enhanced expression of JAML in cultured macrophages was observed following exposure of the cells to oxLDL. The functional role of JAML in atherosclerosis and macrophages function was assessed by interference of JAML with shRNA in vivo and siRNA in vitro Silencing of JAML in mice significantly attenuated atherosclerotic lesion formation, reduced necrotic core area, increased plaque fibrous cap thickness, decreased macrophages content and inflammation. In addition, histological staining showed that JAML deficiency promoted plaques to stable phenotype. In vitro, JAML siRNA treatment lowered the expression of inflammatory cytokines in macrophages treated with oxLDL. The mechanism by which JAML mediated the inflammatory responses may be related to the ERK/NF-κB activation. Conclusions: Our results demonstrated that therapeutic drugs which antagonize the function of JAML may be a potentially effective approach to attenuate atherogenesis and enhance plaque stability.

Long noncoding RNA LINC00341 promotes the vascular smooth muscle cells proliferation and migration via miR-214/FOXO4 feedback loop

Increasing evidences have indicated the vital roles of long noncoding RNA (lncRNA) in the atherosclerosis. However, whether lncRNA LINC00341 play pivotal roles in the vascular smooth muscle cells (VSMCs) is still unclear. This work presents the authentic functions of LINC00341 on the proliferation and migration of VSMCs and unveils the underlying mechanism. Functional experiment data demonstrated that LINC00341 expression was increased in the ox-LDL induced VSMCs with dose-dependent and time-dependent mode. Moreover, the knockdown of LINC00341 suppressed the proliferation and migration ability of VSMCs. Mechanically, we found that LINC00341 promoted the FOXO4 protein expression via sponging miR-214, which, in return, resulting in the transcription activation of LINC00341. In conclusion, the results conclude that LINC00341 promotes the proliferation and migration of VSMCs and confirm the positive feedback loop of LINC00341/miR-214/FOXO4 axis.

LncRNA MEG8 regulates vascular smooth muscle cell proliferation, migration and apoptosis by targeting PPARα

Atherosclerosis is the leading risk factor for cardiovascular disease, in which vascular smooth muscle cell (VSMC) proliferation and apoptosis play an important role. Research has demonstrated that long non-coding RNAs (lncRNAs) are critical regulatory factors for VSMC function, however, the molecular mechanism leading to this pathology is still not fully understood. To explore this further, an ox-LDL induced VSMC model was established, in which lncRNA MEG8 expression was suppressed, while miR-181a-5p was enhanced in a dose- and time-dependent manner. Enhanced MEG8 expression suppressed the proliferation and migration ability of VSMCs, and induced apoptosis. Mechanically, MEG8 was found to promote the PPARα protein via sponging miR-181a-5p. Rescue experiments demonstrated that MEG8 and PPARα collectively regulate the proliferation, migration and apoptosis of VSMCs. Overall, this research illustrates that MEG8 regulates the proliferation and migration of VSMCs via the MEG8/miR-181a/PPARα axis.

Urotensin II: an inflammatory cytokine

Urotensin II (UII) is a polypeptide molecule with neurohormone-like activity. It has been confirmed that UII is widely distributed in numerous organs of different animal species from fish to mammals, including humans. The UII receptor is orphan G-protein coupled receptor 14, also known as UT. The tissue distribution of UII and UT is highly consistent, and their expression may be regulated by autocrine and paracrine mechanisms. In the body, UII has many physiological and pathophysiological activities, such as vasoconstrictor and vasodilatory actions, cell proliferation, pro-fibrosis, neuroendocrine activity, insulin resistance, and carcinogenic and inflammatory effects, which have been recognized only in recent years. In fact, UII is involved in the process of inflammatory injury and plays a key role in the onset and development of inflammatory diseases. In this paper, we will review the roles UII plays in inflammatory diseases.

The role of neutrophils in the pathogenesis of atherosclerosis

Atherosclerosis (AS) is one of the causes of cardiovascular disease. The formation of atherosclerotic lesions of the arteries is a long process, and clinical symptoms appear already at the stage of atherosclerotic plaque (ASB), which prevents blood flow and can cause coronary heart disease, as well as acute coronary syndrome. The study of atherosclerosis mechanisms at the subclinical level is relevant. This article provides a summary of current data on the structure and functions of neutrophils (NF) in physiological processes. Particular attention is paid to the participation of neutrophils in the damage and formation of vascular endothelial dysfunction. Discusses several mechanisms of involvement of neutrophils in atherogenesis: the production of reactive oxygen species, which cause direct endothelial damage; the synthesis of cytokines that trigger the migration of leukocytes in inflammation; the formation of protein complexes with cholesterol, contributing to their deposition in the vessels, and neutrophil traps, triggering destructive-alterative reactions.

The Impact of Integrin β2 on Granulocyte/Macrophage Progenitor Proliferation

Previously, we reported that although the HSPC frequency in bone marrow cells (BMC) was comparable between β2-/- and β2+/+ mice, transplantation of β2-/- BMC into lethally irradiated CD45.1 recipient resulted in more myeloid cell production than β2+/+ BMC. The objective of this study is to address if integrin β2 deficiency skews granulocyte/macrophage progenitor (GMP) proliferation. FACS analysis demonstrated that GMP frequency and cell number were higher and megakaryocyte/erythrocyte progenitor frequency and cell number were lower in β2-/- mice than β2+/+ mice. However, the common myeloid progenitors (CMP) frequency and cell number were similar between the two groups. The increased GMP number was due to GMP proliferation as evidenced by the percentage of BrdU-incorporating GMP. Whole genome transcriptome analysis identified increased FcεRIα expression in β2-/- CMP compared to β2+/+ CMP. FcεRIα expression on β2-/- GMP was detected increased in β2-/- mice by qRT-PCR and FACS. Although transplantation of FcεRIα^hi GMP or FcεRIα^lo GMP into lethally irradiated CD45.1 recipient resulted in comparable myeloid cell production, transplantation of β2 deficient FcεRIα^hi GMP generated more myeloid cells than β2+/+ FcεRIα^hi GMP. GATA2 expression was increased in β2-/- GMP. Using a luciferase reporter assay, we demonstrated that mutation of the GATA2 binding site in the FcεRIα promoter region diminished FcεRIα transcription. In vitro, the addition of IgE, the ligand of FcεRIα, promoted GMP expansion, which was abrogated by inhibition of JNK phosphorylation. Integrin β2 deficiency promoted GMP proliferation and myeloid cell production, which was mediated via FcεRIα/IgE-induced JNK phosphorylation in GMP. Stem Cells 2019;37:430-440.

Amphiregulin Regulates Phagocytosis-Induced Cell Death in Monocytes via EGFR and Matrix Metalloproteinases

Neonates are highly susceptible to microbial infections which is partially attributable to fundamental phenotypic and functional differences between effector cells of the adult and neonatal immune system. The resolution of the inflammation is essential to return to tissue homeostasis, but given that various neonatal diseases, such as periventricular leukomalacia, necrotizing enterocolitis, or bronchopulmonary dysplasia, are characterized by sustained inflammation, newborns seem predisposed to a dysregulation of the inflammatory response. Targeted apoptosis of effector cells is generally known to control the length and extent of the inflammation, and previous studies have demonstrated that phagocytosis-induced cell death (PICD), a special type of apoptosis in phagocytic immune cells, is less frequently triggered in neonatal monocytes than in adult monocytes. We concluded that a rescue of monocyte PICD could be a potential therapeutic approach to target sustained inflammation in neonates. The EGFR ligand amphiregulin (AREG) is shed in response to bacterial infection and was shown to mediate cellular apoptosis resistance. We hypothesized that AREG might contribute to the reduced PICD of neonatal monocytes by affecting apoptosis signaling. In this study, we have examined a cascade of signaling events involved in extrinsic apoptosis by using a well-established in vitro E. coli infection model in monocytes from human peripheral blood (PBMO) and cord blood (CBMO). We found that CBMO shows remarkably higher pro-AREG surface expression as well as soluble AREG levels in response to infection as compared to PBMO. AREG increases intracellular MMP-2 and MMP-9 levels and induces cleavage of membrane-bound FasL through engagement with the EGF receptor. Our results demonstrate that loss of AREG rescues PICD in CBMO to the level comparable to adult monocytes. These findings identify AREG as a potential target for the prevention of prolonged inflammation in neonates.

Association of monocyte myeloperoxidase with incident cardiovascular disease: The Atherosclerosis Risk in Communities Study

Myeloperoxidase (MPO) is a heme-containing peroxidase found in azurophilic granules of neutrophils and monocytes. Epidemiological studies have reported greater plasma MPO concentration to be associated with increased incidence of several cardiovascular diseases (CVD), but the association of intracellular monocyte MPO (mMPO) with CVD is unclear. The prospective population-based Atherosclerosis Risk in Communities (ARIC) cohort study measured mMPO using flow cytometry in 1,465 participants. The association of mMPO with incident cardiovascular disease (CVD, comprising incident coronary heart disease (CHD), heart failure, stroke, peripheral artery disease, and cardiovascular mortality) was examined over a median 9.6 years of follow-up (n = 290 CVD events). There was no statistically significant association between mMPO and all incident CVD events in either age, sex, and race-adjusted proportional hazards models (HR (95% CI) across tertiles of mMPO: 1, 1.09 (0.76, 1.57), and 0.78 (0.52, 1.15), P-trend = 0.21) or adjusted for other major CVD risk factors (HR (95% CI): 1, 1.17 (0.81, 1.69), and 0.87 (0.58, 1.29), P-trend = 0.50). There also was no association between mMPO tertiles and incident CHD, heart failure, or all-cause mortality, examined separately. In conclusion, intracellular monocyte myeloperoxidase was not associated with incident cardiovascular disease in this prospective population-based study.

Anti-Inflammatory Effects of Resveratrol: Mechanistic Insights

Inflammation is the principal response invoked by the body to address injuries. Despite inflammation constituting a crucial component of tissue repair, it is well known that unchecked or chronic inflammation becomes deleterious, leading to progressive tissue damage. Studies over the past years focused on foods rich in polyphenols with anti-inflammatory and immunomodulatory properties, since inflammation was recognized to play a central role in several diseases. In this review, we discuss the beneficial effects of resveratrol, the most widely investigated polyphenol, on cancer and neurodegenerative, respiratory, metabolic, and cardiovascular diseases. We highlight how resveratrol, despite its unfavorable pharmacokinetics, can modulate the inflammatory pathways underlying those diseases, and we identify future opportunities for the evaluation of its clinical feasibility.