Interleukin 6 gene transcripts are expressed in human atherosclerotic lesions

Essential and Non-Essential Metals and Metalloids and Their Role in Atherosclerosis

Peripheral arterial disease (PAD) is becoming more prevalent in the aging developed world and can have significant functional impacts on patients. There is a recent recognition that environmental toxicants such as circulating metals and metalloids may contribute to the pathogenesis of atherosclerotic disease, but the mechanisms are complex. While the broad toxic biologic effects of metals in human systems have been extensively reviewed, the role of non-essential exposure and essential metal aberrancy in PAD specifically is less frequently discussed. This review of the literature describes current scientific knowledge regarding the individual roles several major metals and metalloids play in atherogenesis and highlights areas where a dearth of data exist. The roles of lead (Pb), arsenic (As), cadmium (Cd), iron (Fe), copper (Cu), selenium (Se) are included. Contemporary outcomes of therapeutic trials aimed at chelation therapy of circulating metals to impact cardiovascular outcomes are also discussed. This review highlights the supported notion of differential metal presence within peripheral plaques themselves, although distinguishing their roles within these plaques requires further illumination.

Interleukin-6: Molecular Mechanisms and Therapeutic Perspectives in Atrial Fibrillation

Atrial fibrillation (AF) is a prevalent cardiac arrhythmia with a multifactorial pathophysiology involving electrical, structural, and autonomic remodeling of the atria. AF is closely associated with elevated interleukin-6 (IL-6) levels, which contribute to atrial remodeling and the progression of AF. This review summarizes the mechanisms by which IL-6 promotes AF through inflammatory pathways, atrial fibrosis, electrical remodeling, and calcium mishandling. Experimental models have demonstrated that IL-6 neutralization reduces the incidence of AF, highlighting its potential as a therapeutic target. Future studies should focus on IL-6 blockade strategies to manage AF, aiming to improve patient outcomes.

Network Pharmacology and Experimental Verification: SanQi-DanShen Treats Coronary Heart Disease by Inhibiting the PI3K/AKT Signaling Pathway

Objective

To employee network pharmacology to predict the components and pathways of SanQi-DanShen (SQDS) in treating coronary heart disease, followed by in vitro experiments to validate the molecular mechanism of SQDS in treating coronary heart disease.

Methods

We sourced the active ingredients and targets of Panax notoginseng and Danshen from the Traditional Chinese Medicine Systems Pharmacology database. Coronary heart disease related genes were retrieved from the OMIM, Genecards, and Therapeutic Target databases. Using Cytoscape 3.7.2 software, we constructed a network diagram illustrating the components and targets of SQDS. The associated targets were then imported into the STRING database to build a protein-protein interaction network. The Metascape database and WeChat software were utilized for Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analyses. Lastly, we performed molecular docking between the key components and related targets using AutoDock Vina. To validate the potential mechanism of SQDS in treating coronary heart disease, we established an acute coronary heart disease rat model via tail vein injection of pituitrin.

Results

Network pharmacology analysis revealed that 65 active ingredients and 167 targets of SQDS are implicated in the treatment of coronary heart disease. The key targets identified include AKT1, TNF, TP53, IL6, and VEGFA. Notably, the PI3K/AKT signaling pathway emerged as the primary pathway. Furthermore, animal experiments showed that, compared to the model group, SQDS significantly reduced levels of TNF-α, IL-6, Bax, and cardiac troponin I, while increasing Bcl-2 content. It also notably suppressed the expression of p-PI3K and p-AKT, thereby offering protection to myocardial tissue.

Conclusion

Through the integrated approach of network pharmacology and molecular docking, we have established that SQDS exerts a multi-component, multi-target, and multi-pathway synergistic therapeutic effect on coronary heart disease. Its mechanism may involve the inhibition of the PI3K/AKT signaling pathway and the reduction of inflammatory factor expression.

The Role of Pro-Inflammatory Cytokines in the Pathogenesis of Cardiovascular Disease

With cardiovascular disease (CVD) being a primary source of global morbidity and mortality, it is crucial that we understand the molecular pathophysiological mechanisms at play. Recently, numerous pro-inflammatory cytokines have been linked to several different CVDs, which are now often considered an adversely pro-inflammatory state. These cytokines most notably include interleukin-6 (IL-6),tumor necrosis factor (TNF)α, and the interleukin-1 (IL-1) family, amongst others. Not only does inflammation have intricate and complex interactions with pathophysiological processes such as oxidative stress and calcium mishandling, but it also plays a role in the balance between tissue repair and destruction. In this regard, pre-clinical and clinical evidence has clearly demonstrated the involvement and dynamic nature of pro-inflammatory cytokines in many heart conditions; however, the clinical utility of the findings so far remains unclear. Whether these cytokines can serve as markers or risk predictors of disease states or act as potential therapeutic targets, further extensive research is needed to fully understand the complex network of interactions that these molecules encompass in the context of heart disease. This review will highlight the significant advances in our understanding of the contributions of pro-inflammatory cytokines in CVDs, including ischemic heart disease (atherosclerosis, thrombosis, acute myocardial infarction, and ischemia-reperfusion injury), cardiac remodeling (hypertension, cardiac hypertrophy, cardiac fibrosis, cardiac apoptosis, and heart failure), different cardiomyopathies as well as ventricular arrhythmias and atrial fibrillation. In addition, this article is focused on discussing the shortcomings in both pathological and therapeutic aspects of pro-inflammatory cytokines in CVD that still need to be addressed by future studies.

Enhanced Akt3 kinase activity reduces atherosclerosis in hyperlipidemic mice in a gender-dependent manner

Akt3 is one of the three members of the serine/threonine protein kinase B (AKT) family, which regulates multiple cellular processes. We have previously demonstrated that global knockout of Akt3 in mice promotes atherogenesis in a macrophage-dependent manner. Whether enhanced Akt3 kinase activity affects atherogenesis is not known. In this study, we crossed atherosclerosis-prone ApoE-/- mice with a mouse strain that has enhanced Akt3 kinase activity (Akt3nmf350) and assessed atherosclerotic lesion formation and the role of macrophages in atherogenesis. Significant reduction in atherosclerotic lesion area and macrophage accumulation in lesions were observed in ApoE-/-/Akt3nmf350 mice fed a Western-type diet. Experiments using chimeric ApoE-/- mice with either ApoE-/-/Akt3nmf350 bone marrow or ApoE-/- bone marrow cells showed that enhanced Akt3 activity specifically in bone marrow-derived cells is atheroprotective. The atheroprotective effect of Akt3nmf350 was more pronounced in male mice. In line with this result, the release of the pro-inflammatory cytokines IL-6, MCP1, TNF-α, and MIP-1α was reduced by macrophages from male but not female ApoE-/-/Akt3nmf350 mice. Levels of IL-6 and TNF-α were also reduced in atherosclerotic lesions of ApoE-/-/Akt3nmf350 male mice compared to ApoE-/- mice. Macrophages from male ApoE-/-/Akt3nmf350 mice were also more resistant to apoptosis in vitro and in vivo and tended to have more pronounced M2 polarization in vitro. These findings demonstrated that enhanced Akt3 kinase activity in macrophages protects mice from atherosclerosis in hyperlipidemic mice in a gender-dependent manner.

Integrin β Expression as a New Diagnostic Marker for Arteriovenous Thrombosis: A Single-Center Prospective Study

Integrin β plays an important role in the pathogenesis of thrombosis and inflammation, and it may be a shared pathogenic mechanism between arterial and venous thromboses. With the goal of identifying new treatment targets for thrombotic diseases and specific diagnostic markers for venous thromboembolism (VTE), this prospective clinical study was performed to clarify the relationship between integrin and thrombosis. The levels of integrin β1-3, interleukin-6 (IL-6), and C-reactive protein were significantly higher in patients with acute myocardial infarction (AMI; n = 44) and acute VTE (n = 43) compared to healthy controls (n = 33). The IL-6 and integrin β1-3 levels were also significantly higher in the AMI group compared to the VTE and control groups. Logistic regression analysis identified IL-6 and integrin β1-3 levels as independent risk factors for thrombotic disease. Based on the receiver-operating characteristic curve, Youden index, sensitivity, and specificity, the diagnostic accuracy value for VTE was greater than 0.8 when integrins β1, β2, and β3 were combined. Overall, these results suggest that integrin β levels can contribute to improving the diagnosis and treatment of arteriovenous thrombosis.

Mast cell-mediated immune regulation in health and disease

Mast cells are important components of the immune system, and they perform pro-inflammatory as well as anti-inflammatory roles in the complex process of immune regulation in health and disease. Because of their strategic perivascular localization, sensitivity and adaptability to the microenvironment, and ability to release a variety of preformed and newly synthesized effector molecules, mast cells perform unique functions in almost all organs. Additionally, Mast cells express a wide range of surface and cytoplasmic receptors which enable them to respond to a variety of cytokines, chemicals, and pathogens. The mast cell's role as a cellular interface between external and internal environments as well as between vasculature and tissues is critical for protection and repair. Mast cell interactions with different immune and nonimmune cells through secreted inflammatory mediators may also turn in favor of disease promoting agents. First and forefront, mast cells are well recognized for their multifaceted functions in allergic diseases. Reciprocal communication between mast cells and endothelial cells in the presence of bacterial toxins in chronic/sub-clinical infections induce persistent vascular inflammation. We have shown that mast cell proteases and histamine induce endothelial inflammatory responses that are synergistically amplified by bacterial toxins. Mast cells have been shown to exacerbate vascular changes in normal states as well as in chronic or subclinical infections, particularly among cigarette smokers. Furthermore, a potential role of mast cells in SARS-CoV-2-induced dysfunction of the capillary-alveolar interface adds to the growing understanding of mast cells in viral infections. The interaction between mast cells and microglial cells in the brain further highlights their significance in neuroinflammation. This review highlights the significant role of mast cells as the interface that acts as sensor and early responder through interactions with cells in systemic organs and the nervous system.

Role of interleukin-6 and interleukin-10 in morphological and functional changes of the blood-brain barrier in hypertriglyceridemia

BACKGROUND

Hypertriglyceridemia is closely linked to atherosclerosis related inflammatory processes and blood-brain barrier (BBB) dysfunction. Using apolipoprotein B-100 (APOB-100) transgenic mice, an animal model of chronic hypertriglyceridemia, we analyzed BBB function and morphology in vitro and ex vivo. Our objective was to determine which BBB characteristics are produced mainly by interleukin (IL)-6, an atherosclerosis promoting cytokine, and whether these actions can be antagonized by IL-10, an anti-inflammatory cytokine.

METHODS

Brain endothelial and glial cell cultures and brain microvessels were isolated from wild type (WT) and APOB-100 transgenic mice and were treated with IL-6, IL-10 and their combination. First, IL-6 and IL-10 production was measured in WT and APOB-100 microvessels using qPCR. Then functional parameters of endothelial cell cultures were analyzed and immunocytochemistry for key BBB proteins was performed.

RESULTS

IL-6 mRNA levels were higher in brain microvessels than in brain parenchyma of APOB-100 transgenic mice. Transendothelial electric resistance and P-glycoprotein activity were lower, and paracellular permeability was higher in cultured APOB-100 brain endothelial cells. These features were sensitive to both IL-6 and IL-10 treatments. A decreased P-glycoprotein immunostaining was measured in transgenic endothelial cells under control conditions and in WT cells after treating them with IL-6. This effect was antagonized by IL-10. Changes in immunostaining for tight junction proteins were observed after IL-6 exposure, which were in part antagonized by IL-10. In glial cell cultures an increase in aquaporin-4 immunolabeling in the transgenic group and an increase in microglia cell density in WT glia cultures was detected after IL-6 treatment, which was antagonized by IL-10. In isolated brain microvessels a decrease in P-glycoprotein immunolabeled area fraction was measured in APOB-100 microvessels under control conditions and in WT microvessels after every cytokine treatment. ZO-1 immunolabeling showed characteristics similar to that of P-glycoprotein. No change was seen in claudin-5 and occludin immunoreactive area fractions in microvessels. A decrease in aquaporin-4 immunoreactivity was measured in WT microvessels treated by IL-6, which was antagonized by IL-10.

CONCLUSION

IL-6 produced in microvessels contributes to BBB impairment observed in the APOB-100 mice. We showed that IL-10 partly antagonizes the effects of IL-6 at the BBB.

Mechanisms of Arsenic Exposure-Induced Hypertension and Atherosclerosis: an Updated Overview

Arsenic is an abundant element in the earth's crust. In the environment and within the human body, this toxic element can be found in both organic and inorganic forms. Chronic exposure to arsenic can predispose humans to cardiovascular diseases including hypertension, stroke, atherosclerosis, and blackfoot disease. Oxidative damage induced by reactive oxygen species is a major player in arsenic-induced toxicity, and it can affect genes expression, inflammatory responses, and/or nitric oxide homeostasis. Exposure to arsenic in drinking water can lead to vascular endothelial dysfunction which is reflected by an imbalance between vascular relaxation and contraction. Arsenic has been shown to inactivate endothelial nitric oxide synthase leading to a reduction of the generation and bioavailability of nitric oxide. Ultimately, these effects increase the risk of vascular diseases such as hypertension and atherosclerosis. The present article reviews how arsenic exposure contributes to hypertension and atherosclerosis development.

Decoding the transcriptome of calcified atherosclerotic plaque at single-cell resolution

Atherogenesis involves an interplay of inflammation, tissue remodeling and cellular transdifferentiation (CTD), making it especially difficult to precisely delineate its pathophysiology. Here we use single-cell RNA sequencing and systems-biology approaches to analyze the transcriptional profiles of vascular smooth muscle cells (VSMCs) and endothelial cells (ECs) in calcified atherosclerotic core (AC) plaques and patient-matched proximal adjacent (PA) portions of carotid artery tissue from patients undergoing carotid endarterectomy. Our results reveal an anatomic distinction whereby PA cells express inflammatory mediators, while cells expressing matrix-secreting genes occupy a majority of the AC region. Systems biology analysis indicates that inflammation in PA ECs and VSMCs may be driven by TNFa signaling. Furthermore, we identify POSTN, SPP1 and IBSP in AC VSMCs, and ITLN1, SCX and S100A4 in AC ECs as possible candidate drivers of CTD in the atherosclerotic core. These results establish an anatomic framework for atherogenesis which forms the basis for exploration of a site-specific strategy for disruption of disease progression.

Single-cell RNA sequencing and systems biology are used to profile the human vascular cell populations in calcified atherosclerotic core plaques from carotid endarterectomy samples, showing an anatomic distinction between gene expression of inflammatory versus matrix-secreting factors.

Increased serum IL-6 is predictive of long-term cardiovascular events in high-risk patients submitted to coronary angiography: an observational study

BACKGROUND

Interleukin-6 (IL-6) is an inflammation-related cytokine associated with an elevated risk of cardiovascular events. In a previous study, we demonstrated that increased IL-6 was predictive of sub-clinical atherosclerotic coronary disease in intermediate-risk patients undergoing coronary angiography. In the present study, we investigated whether increased serum IL-6 is predictive of cardiovascular events in high-risk patients.

METHODS

In this observational study, consecutive patients referred for elective coronary angiography due to stable chest pain/myocardial ischemia had IL-6 measured immediately before the procedure. Long-term follow-up was performed by phone call or e-mail, and their clinical registries were revised. The primary outcome was a composite of new myocardial infarction, new ischemic stroke, hospitalization due to heart failure, new coronary revascularization, cardiovascular death, and death due to all causes.

RESULTS

From 141 patients submitted to coronary angiography and IL-6 analysis, 100 had complete follow-up data for a mean of 5.7 years. The median age was 61.1 years, 44% were men, and 61% had type-2 diabetes. The median overall time-to-event for the primary outcome was 297 weeks (95% confidence interval [CI] 266.95-327.16). A receiver operator characteristic curve defined the best cut-off value of baseline serum IL-6 (0.44 pg/mL) with sensitivity (84.37%) and specificity (38.24%) to define two groups. High (> 0.44 pg/mL) IL-6 levels were predictive of cardiovascular events. (p for interaction = 0.015) (hazard ratio = 2.81; 95% CI 1.38-5.72, p = 0.01). Subgroup analysis did not find interactions between patients with or without diabetes, obesity, or hypertension.

CONCLUSION

In conclusion, an interleukin-6 level higher than 0.44 pg/mL, obtained just before elective coronary angiography, was associated with a poorer prognosis after a mean of 5,7-year. A pre-procedure IL-6 below 0.44 pg/mL, on the other hand, has a very good negative predictive value, suggesting a good prognosis, and may be useful to better indicate coronary angiography in high-risk patients. .

Identification of Potential Ferroptosis-Related Biomarkers and Immune Infiltration in Human Coronary Artery Atherosclerosis

Objective

Ferroptosis is a specific subtype of programmed cell death, which plays an essential role in the immune-associated disease, atherosclerosis (AS). The purpose of this study was to identify potential ferroptosis-related gene biomarkers and its association with immune infiltration characteristics in atherosclerosis with bioinformatics methods.

Methods

Differentially expressed genes (DEGs) between AS and control groups were screened from GSE40231, analyzed for functional enrichment and then intersected with ferroptosis-related genes. Then, a random forest model was constructed based on these differentially expressed ferroptosis-related genes (DE-FRGs) and validated with dataset GSE132651. The performance of the models was evaluated with the area under receiver operating characteristic curves (AUC). Finally, we analyzed the correlation between DE-FRGs above and the characteristics of immune infiltration via CIBERSORT method.

Results

Six DE-FRGs (IL6, ANGPTL7, CDKN1A, AKR1C3, NOX4 and VLDLR) were detected based on dataset of GSE40231. Furthermore, a random forest model was constructed based on them with a compelling diagnostic performance of AUC = 0.8974 in the validation dataset GSE132651. In addition, the proportion of follicular helper T (Tfh) cells was significantly higher in AS group (P < 0.001). And we found significant correlation relationship between Tfh and expression level of ANGPTL7 (R = 0.35, P < 0.01), CDKN1A (R = 0.4, P < 0.0001), AKR1C3 (R = 0.64, P < 0.0001), NOX4 (R = 0.32, P < 0.01) and VLDLR (R = −0.43, P < 0.0001).

Conclusion

This study identified 6 DE-FRGs and validated a predicted model for the early prediction of AS, which also proved the close relationship between ferroptosis and immunity in the pathogenesis of AS.

Diagnostic value of using exosome-derived cysteine-rich protein 61 as biomarkers for acute coronary syndrome

Acute coronary syndrome (ACS) is the main manifestation of cardiovascular disease and the primary cause of adult hospitalization in China. There is an urgent demand for novel biomarkers for the diagnosis of ACS. Although plasma cysteine-rich protein 61 (Cyr61) has been previously reported to be accurate for ACS diagnosis, the accuracy of exosomal Cyr61 in ACS diagnosis remains unknown. In the present study, the aim was to assess the potential of applying exosomal Cyr61 in ACS diagnosis and to explore the role of Cyr61 in vascular remodeling in vitro. The abundance of Cyr61 in plasma-derived exosomes from patients with unstable angina pectoris (UAP), acute myocardial infarction (AMI) patients in addition to those isolated from healthy individuals were detected using an ELISA kit. The association between exosomal Cyr61 levels and clinical characteristics of ACS patients was analyzed through χ² test, Fisher's exact test and Student's t-test. Receiver operating characteristic (ROC) curve analysis was used to determine the accuracy of using exosomal Cyr61 as a biomarker of ACS diagnosis. Furthermore, independent predictors of the existence of ACS were investigated through a multivariate analysis. Subsequently, the role of Cyr61 on vascular remodeling was evaluated in vascular smooth muscle cells (VSMCs) upon oxidized low-density lipoprotein (ox-LDL) treatment by performing Cyr61 knockdown, Cell Counting Kit-8, flow cytometry and Transwell assays. Exosomal Cyr61 expression was found to be significantly elevated in patients with ACS compared with that in healthy individuals. In addition, exosomal Cyr61 levels were associated with sex, family history of ACS and glucose levels. ROC curve analyzes revealed that exosomal Cyr61 expression could be used to differentiate patients with UAP, AMI and ACS from healthy individuals. Furthermore, exosomal Cyr61 levels were independently correlated with the existence of ACS. In vitro, Cyr61 expression was demonstrated to be significantly increased in VSMCs after ox-LDL exposure in a concentration- and time-dependent manner. Functionally, the elevated cell viability and migration of VSMCs induced by ox-LDL were partially but significantly inhibited by Cyr61 knockdown. By contrast, knocking down Cyr61 expression significantly elevated the apoptosis rate of VSMCs compared with that in the ox-LDL-treated group. In conclusion, data from the present study suggest that Cyr61 serve a regulatory role in vascular remodeling in vitro, where exosomal Cyr61 levels may represent a promising biomarker for ACS diagnosis.

Matrine ameliorates the inflammatory response and lipid metabolism in vascular smooth muscle cells through the NF-κB pathway

Atherosclerosis is a chronic inflammatory disease associated with inflammatory responses and the uncontrolled proliferation and excessive apoptosis of vascular smooth muscle cells. However, the effects of matrine on the inflammatory response, abnormal lipid metabolism and cell proliferation and apoptosis marker proteins in human aortic vascular smooth muscle cells (HAVSMCs) have not been elucidated. Therefore, the present study aimed to investigate the effect of matrine on an in vitro model of atherosclerosis using HAVSMCs. The HAVSMCs were divided into normal, model and matrine groups. The model group was treated with oxidized low-density lipoprotein (oxLDL), the matrine group was treated with oxLDL and matrine and the normal group was treated with physiological saline. Total cholesterol (TC), free cholesterol (FC) and cholesterol ester (CE) levels were measured in the cell supernatant. In addition, the relative mRNA levels of inflammatory factors were quantified using reverse transcription-quantitative PCR, and the cell proliferation and apoptosis rates were evaluated using Cell Counting Kit-8 and flow cytometry assays, respectively. The expression levels of proteins associated with proliferation and apoptosis were also determined using western blotting. The levels of TC, FC and CE and the mRNA levels of IL-1β, IL-6, and TNF-α in the matrine group were lower than those in the model group, but higher than those in the normal group. After 48 and 96 h of treatment, the cell proliferation and apoptotic rates were lower in the matrine group compared with the model group. The relative expression levels of Ki-67, proliferating cell nuclear antigen and Bax were decreased, while that of Bcl-2 was increased in the matrine group compared with the model group. In addition, the relative protein expression of nuclear factor κB (NF-κB) in the matrine group was lower than that in the model group, but higher than that in the normal group. In summary, matrine inhibited activation of the NF-κB pathway and reduced cell proliferation and apoptosis in the oxLDL-induced atherosclerosis model, and exhibited anti-inflammatory effects. These results suggest that matrine attenuated abnormal biological reactions in HAVSMCs through the NF-κB pathway.

Regulation of Macrophage Activation and Differentiation in Atherosclerosis

Chronic inflammation is a hallmark of atherosclerosis and macrophages play a central role in controlling inflammation at all stages of atherosclerosis. In atherosclerosis, macrophages and monocyte-derived macrophages are continuously exposed to cholesterol, oxidized lipids, cell debris, cytokines, and chemokines. Not only do these stimuli induce a specific macrophage phenotype, but they also interact extensively, leading to macrophage heterogeneity in atherosclerotic plaques. Herein, we review the diverse phenotypes of macrophages, the mechanisms underlying macrophage activation, and the contributions of macrophages to atherosclerosis in this context. We also summarize recent studies on foamy macrophages and monocyte-derived macrophages in plaque during disease progression. We provide a comprehensive overview of transcriptional, epigenetic, and metabolic reprogramming of macrophages and discuss the emerging concepts of targeting cytokines and macrophages to modulate atherosclerosis.

Association of interleukin 6 -174 G/C polymorphism with coronary artery disease and circulating IL-6 levels: a systematic review and meta-analysis

INTRODUCTION

Circulating IL-6 levels and at least one polymorphic form of IL6 gene (IL6 -174 G/C, rs1800795) have been shown to be independently associated with coronary artery disease (CAD) by several investigators. Despite more than 12 published meta-analyses on this subject, association of -174 G/C with CAD, especially amongst distinct ancestral population groups remain unclear. We, therefore, conducted a systematic review and an updated meta-analysis to comprehensively ascertain the association of IL6 -174 G/C with CAD and circulating IL-6 levels.

MATERIALS AND METHODS

Relevant case-control/cohort studies investigating association of -174 G/C with CAD and circulating IL-6 levels were identified following a comprehensive online search. Association status for CAD was determined for the pooled sample, as well as separately for major ancestral subgroups. Association status for circulating IL-6 levels was assessed for the pooled sample, as well as separately for CAD cases and CAD free controls. Study-level odds ratios (OR) and 95% confidence intervals (CI) were pooled using random/fixed-effects model.

RESULTS

Quantitative synthesis for the CAD endpoint was performed using 55 separate qualifying studies with a collective sample size of 51,213 (19,160 cases/32,053 controls). Pooled association of -174 G/C with CAD was found to be statistically significant through dominant (OR 1.15; 95% CI 1.05-1.25, p = 0.002) as well as allelic genetic model comparisons (OR 1.13, 95% CI 1.06-1.21, p = 0.0003). This effect was largely driven by Asian and Asian Indian ancestral subgroups, which also showed significant association with CAD in both genetic model comparisons (OR range 1.29-1.53, p value range ≤ 0.02). Other ancestral subgroups failed to show any meaningful association. Circulating IL-6 levels were found to be significantly higher amongst the 'C' allele carriers in the pooled sample (Standard mean difference, SMD 0.11, 95% CI 0.01-0.22 pg/ml, p = 0.009) as well as in the CAD free control subgroup (SMD 0.10, 95% CI 0.02-0.17 pg/ml, p = 0.009), though not in the CAD case subgroup (SMD 0.17, 95% CI = - 0.02 to 0.37, p = 0.12).

CONCLUSIONS

The present systematic review and meta-analysis demonstrate an overall association between IL6 -174 G/C polymorphism and CAD, which seems to be mainly driven by Asian and Asian Indian ancestral subgroups. Upregulation of plasma IL-6 levels in the 'C' allele carriers seems to be at least partly responsible for this observed association. This warrants further investigations with large, structured case-control studies especially amongst Asian and Asian Indian ancestral groups.

Interleukin-6: A Novel Target for Cardio-Cerebrovascular Diseases

Cardio-Cerebrovascular Disease is a collective term for cardiovascular disease and cerebrovascular disease, being a serious threat to human health. A growing number of studies have proved that the content of inflammatory factors or mediators determines the stability of vascular plaque and the incidence of cardio-cerebrovascular event, and involves in the process of Cardio-Cerebrovascular Diseases. Interleukin-6 is a widely used cytokine that causes inflammation and oxidative stress, which would further result in cardiac and cerebral injury. The increased expression of interleukin-6 is closely related to atherosclerosis, myocardial infarction, heart failure and ischemic stroke. It is a key risk factor for these diseases by triggering inflammatory reaction and inducing other molecules release. Therefore, interleukin-6 may become a potential target for Cardio-Cerebrovascular Diseases in the future. This paper is aimed to discuss the expression changes and pathological mechanisms of interleukin-6 in Cardio-Cerebrovascular Diseases, and to provide a novel strategy for the prevention and treatment of Cardio-Cerebrovascular Diseases.

Anti-inflammatory and Immunomodulatory Therapies in Atherosclerosis

Hypercholesterolemia is a major risk factor in atherosclerosis development and lipid-lowering drugs (i.e., statins) remain the treatment of choice. Despite effective reduction of LDL cholesterol in patients, a residual cardiovascular risk persists in some individuals, highlighting the need for further therapeutic intervention. Recently, the CANTOS trial paved the way toward the development of specific therapies targeting inflammation, a key feature in atherosclerosis progression. The pre-existence of multiple drugs modulating both innate and adaptive immune responses has significantly accelerated the number of translational studies applying these drugs to atherosclerosis. Additional preclinical research has led to the discovery of new therapeutic targets, offering promising perspectives for the treatment and prevention of atherosclerosis. Currently, both drugs with selective targeting and broad unspecific anti-inflammatory effects have been tested. In this chapter, we aim to give an overview of current advances in immunomodulatory treatment approaches for atherosclerotic cardiovascular diseases.

Intercellular adhesion molecule-1 is a surrogate biomarker for subclinical atherosclerosis in Type 2 diabetes mellitus

Aim: We aimed to investigate biomarkers of inflammation, oxidative stress as surrogate markers of subclinical atherosclerosis in patients with Type 2 diabetes mellitus (T2DM). Materials & methods: Subjects were grouped based on carotid intima media thickness (CIMT). Group 1: healthy controls (CIMT <0.57 mm); Group 2: T2DM without subclinical atherosclerosis (CIMT <0.57 mm); Group 3: T2DM with subclinical atherosclerosis (CIMT ≥0.57 mm). Results: Significantly higher MDA, Hs-CRP, Ox-LDL, PTX-3, IL-6, ICAM-1 and lower FRAP, IL-10 levels in T2DM groups compared with controls (p = 0.001). Changes were more significant in Group 3 compared with Group 2. ICAM-1 had the highest sensitivity and specificity at a cut-off value of >40.34 ng/ml compared with Ox-LDL and PTX-3 (p < 0.001). Conclusion: ICAM can be considered as an alternate surrogate biomarker of CIMT.

Monocyte Recruitment, Specification, and Function in Atherosclerosis

Atherosclerotic lesions progress through the continued recruitment of circulating blood monocytes that differentiate into macrophages within plaque. Lesion-associated macrophages are the primary immune cells present in plaque, where they take up cholesterol and store lipids in the form of small droplets resulting in a unique morphology termed foam cell. Recent scientific advances have used single-cell gene expression profiling, live-cell imaging, and fate mapping approaches to describe macrophage and monocyte contributions to pro- or anti-inflammatory mechanisms, in addition to functions of motility and proliferation within lesions. Yet, many questions regarding tissue-specific regulation of monocyte-to-macrophage differentiation and the contribution of recruited monocytes at stages of atherosclerotic disease progression remain unknown. In this review, we highlight recent advances regarding the role of monocyte and macrophage dynamics in atherosclerotic disease and identify gaps in knowledge that we hope will allow for advancing therapeutic treatment or prevention strategies for cardiovascular disease.

Expression of Interleukin 6 signaling receptors in carotid atherosclerosis

Interleukin (IL) 6 contributes to atherosclerotic plaque development through IL6 membrane-bound (IL6R and gp130) and soluble (sIL6R and sgp130) receptors. We investigated IL6 receptor expression in carotid plaques and its correlation with circulating IL6 and soluble receptor levels. Plasma samples and carotid plaques were obtained from 78 patients in the Biobank of Karolinska Endarterectomies study. IL6, sIL6R, and sgp130 were measured in plasma and IL6, IL6R, sIL6R, GP130, and sGP130-RAPS (sGP130) gene expression assessed in carotid plaques. Correlations between plaque IL6 signaling gene expression and plasma levels were determined by Spearman’s correlation. Differences in plasma and gene expression levels between patients with (n = 53) and without (n = 25) a history of a cerebral event and statin-treated (n = 65) and non-treated (n = 11), were estimated by Kruskal–Wallis. IL6 and its receptors were all expressed in carotid plaques. There was a positive, borderline significant, moderate correlation between plasma IL6 and sIL6R and the respective gene expression levels (rho 0.23 and 0.22, both p = 0.05). IL6R expression was higher in patients with a history of a cerebrovascular event compared to those without (p = 0.007). Statin-treated had higher IL6R, sIL6R, and sGP130 expression levels and plasma sIL6R compared to non-treated patients (all p < 0.05). In conclusion, all components of the IL6 signaling pathways are expressed in carotid artery plaques and IL6 and sIL6R plasma levels correlate moderately with IL6 and sIL6R. Our data suggest that IL6 signaling in the circulation might mirror the system activity in the plaque, thus adding novel perspectives to the role of IL6 signaling in atherosclerosis.

Notch1 signaling determines the plasticity and function of fibroblasts in diabetic wounds

Fibroblasts play a pivotal role in wound healing. However, the molecular mechanisms determining the reparative response of fibroblasts remain unknown. Here, we identify Notch1 signaling as a molecular determinant controlling the plasticity and function of fibroblasts in modulating wound healing and angiogenesis. The Notch pathway is activated in fibroblasts of diabetic wounds but not in normal skin and non-diabetic wounds. Consistently, wound healing in the FSP-1 ^+/- ;ROSA ^LSL-N1IC+/+ mouse, in which Notch1 is activated in fibroblasts, is delayed. Increased Notch1 activity in fibroblasts suppressed their growth, migration, and differentiation into myofibroblasts. Accordingly, significantly fewer myofibroblasts and less collagen were present in granulation tissues of the FSP-1 ^+/- ;ROSA ^LSL-N1IC+/+ mice, demonstrating that high Notch1 activity inhibits fibroblast differentiation. High Notch1 activity in fibroblasts diminished their role in modulating the angiogenic response. We also identified that IL-6 is a functional Notch1 target and involved in regulating angiogenesis. These findings suggest that Notch1 signaling determines the plasticity and function of fibroblasts in wound healing and angiogenesis, unveiling intracellular Notch1 signaling in fibroblasts as potential target for therapeutic intervention in diabetic wound healing.

Cathelicidin Modulates Vascular Smooth Muscle Cell Phenotypic Switching through ROS/IL-6 Pathway

Vascular smooth muscle cells (VSMC) are stromal cells of the blood vessels and their differentiation is thought to be essential during atherosclerosis. Cathelicidin-related antimicrobial peptides (CRAMP) are suggested to play a role in the development of atherosclerosis. Even so, the relationship of CRAMP and VSMC remains unclear. The present study was to determine whether CRAMP regulates VSMC phenotypic transformation and underlying mechanisms. We demonstrated that CRAMP could reverse platelet-derived growth factor-BB (PDGF-BB)-induced VSMC phenotypic transformation, evidencing by increasing α-smooth muscle actin (α-SMA), smooth muscle 22α (SM22α) and decreasing of proliferation and migration. Further studies showed that CRAMP inhibited nuclear factor κB (NF-κB)-induced autocrine of interleukin-6 (IL-6), which further activated of janus kinase 2 (JAK2)/signal transducer and activator 3 (STAT3). Meanwhile, our data showed that CRAMP can significantly inhibit PDGF-BB enhanced intracellular reactive oxygen species (ROS) level which further affected the NF-κB signaling pathway, indicating that CRAMP can regulate the phenotypic transformation of VSMC by regulating oxidative stress. These results indicated that CRAMP regulated the differentiation of VSMC by inhibiting ROS-mediated IL-6 autocrine, suggesting that targeting CRAMP is a potential avenue for regulating the differentiation of VSMC and treatment of atherosclerosis.

The protective effects of aloperine against ox-LDL-induced endothelial dysfunction and inflammation in HUVECs

Atherosclerosis is a potentially life-threatening cardiovascular disease characterized by chronic endothelial inflammation and the formation of atherosclerotic lesions. Circulating ox-LDL is known to induce atherosclerosis by triggering oxidative stress, the expression of inflammatory mediators and adhesion molecules, as well as downregulating the atheroprotective transcriptional factor KLF2. Aloperine is an alkaloid compound isolated from the plant Sophora alopecuroides. Here, we employed various experimental methods to determine the effects of aloperine on ox-LDL-induced markers of atherosclerosis. DHE staining revealed that aloperine may restore the oxidant/antioxidant balance in HUVECs by reducing the level of ROS and rescuing the reduction in NOQ-1 and GCLC induced by ox-LDL. Aloperine treatment reduced ox-LDL-induced expression of IL-6, MCP-1, VCAM-1, and E-selectin and rescued the reduction in KLF2. Aloperine also downregulated ox-LDL-induced expression of the LOX-1. We also demonstrate that aloperine improved cell viability and inhibited the adhesion of U937 monocytes to HUVECs. Finally, we demonstrate that the effects of aloperine are mediated through the rescue of KLF2 expression via suppression of the phosphorylation of p53 protein. Together, our results implicate the potential of aloperine as a safe and effective antiatherosclerosis treatment.

Agonism of GPR120 prevents ox-LDL-induced attachment of monocytes to endothelial cells

Oxidized low-density lipoprotein (ox-LDL)-induced endothelial inflammation plays an important role in the development of cardiovascular diseases. G protein-coupled receptors (GPCR) are gaining traction as potential treatment targets due to their roles in mediating a wide range of physiological processes. GPR120 is a recently identified omega-3 fatty acid receptor. We hypothesized that agonism of GPR120 might attenuate ox-LDL-induced endothelial dysfunction. In the present study, we tested the effects of two GPR120 agonists-GW9508 and TUG-891-in mitigating endothelial insult induced by ox-LDL in human aortic endothelial cells (HAECs). Real-time PCR, western blot, and ELISA analyses were used in our experiments. Our findings demonstrate that GPR120 is downregulated by exposure to ox-LDL, suggesting a role for GPR120 in mediating ox-LDL insult. Furthermore, we found that agonism of GPR120 could suppress oxidative stress and inflammation by inhibiting the production of reactive oxygen species and the expression of proinflammatory cytokines. Importantly, we show that agonism of GPR120 prevents the attachment of monocytes to endothelial cells by suppressing the expression of VCAM-1 and E-selectin. Finally, we show that agonism of GPR120 exerts a remarkable atheroprotective effect by elevating the expression level of Krüppel-like factor 2 (KLF2). Together, our results demonstrate a potential role for specific agonism of GPR120 in the prevention of endothelial damages induced by ox-LDL.

Metabolic Health, Insulin, and Breast Cancer: Why Oncologists Should Care About Insulin

Studies investigating the potential link between adult pre-menopausal obesity [as measured by body mass index (BMI)] and triple-negative breast cancer have been inconsistent. Recent studies show that BMI is not an exact measure of metabolic health; individuals can be obese (BMI > 30 kg/m²) and metabolically healthy or lean (BMI < 25 kg/m²) and metabolically unhealthy. Consequently, there is a need to better understand the molecular signaling pathways that might be activated in individuals that are metabolically unhealthy and how these signaling pathways may drive biologically aggressive breast cancer. One key driver of both type-2 diabetes and cancer is insulin. Insulin is a potent hormone that activates many pathways that drive aggressive breast cancer biology. Here, we review (1) the controversial relationship between obesity and breast cancer, (2) the impact of insulin on organs, subcellular components, and cancer processes, (3) the potential link between insulin-signaling and cancer, and (4) consider time points during breast cancer prevention and treatment where insulin-signaling could be better controlled, with the ultimate goal of improving overall health, optimizing breast cancer prevention, and improving breast cancer survival.

Gene variants in the NF-KB pathway (NFKB1, NFKBIA, NFKBIZ) and risk for early-onset coronary artery disease

The nuclear-factor kappa-beta (NF-KB) is a driver of inflammation, and plays an important role in the pathogenesis of atherosclerosis and coronary artery disease (CAD). Early-onset CAD is defined as a coronary ischaemic episode at an age ≤55 years, and in our population was strongly associated with male sex and smoking. Our aim was to determine whether common variants in three NF-KB genes were associated with early-onset CAD. We studied 609 patients with early-onset CAD and 423 healthy controls, all male. Allele and genotype frequencies for the NFKB1 rs28362491 (-94 delATTG) and NFKBIA rs8904 were not significantly different between the two groups. For the NFKBIZ rs3217713, the deletion allele was significantly more frequent in the patients than in controls (0.27 vs. 0.22; p = 0.004). Deletion-carriers were more frequent in the patients (p < 0.001), with an OR = 1.48 (95%CI = 1.15-1.90). We performed a multiple logistic regression (linear generalized model) with smoking, hypercholesterolemia, type 2 diabetes, hypertension, and the rs3217713 deletion carriers remained significantly associated with early-onset CAD (p = 0.01). In our population, the NFKBIZ variant was an independent risk factor for developing early-onset CAD.

Gene polymorphism associated with TNF-α (G308A) IL-6 (C174G) and susceptibility to coronary atherosclerotic heart disease: A meta-analysis

To evaluate the association between gene polymorphisms of TNF-α G308A, IL-6 C174G, and coronary atherosclerotic heart disease (CHD) risk.We used computers to collect related case-control studies. After screening, a meta-analysis was conducted to assess the strength of association by Stata 12.0 software.Thirty-five articles were included. Among them, 17 studies were related to TNF-α (G308A) gene mutation and CHD, and 18 studies examined IL-6 (C174G) gene mutation. According to the results of subgroup analysis of ethnicity, it suggested that TNF-α (G308A) polymorphism was not significantly associated with CHD risk under all models in Asians (P > .05). There were no connected of IL-6 C174G polymorphism with CHD risk under all models in Caucasians after subgroup analysis (P > .05).The present evidence shows that TNF-α (G308A) have no connected with the risk of CHD in Asians; IL-6 (C174G) gene were not associated with the risk of CHD in Caucasians.

Cytokine production capabilities of human primary monocyte-derived macrophages from patients with diabetes mellitus type 2 with and without diabetic peripheral neuropathy

INTRODUCTION

Monocytes from patients with diabetes mellitus type 2 (DM2) are dysfunctional, persistently primed, and prone to a proinflammatory phenotype. This may alter the phenotype of their differentiation to macrophages and result in diabetic peripheral neuropathy (DPN), nerve damage, nerve sensitization, and chronic pain. We have previously demonstrated that CD163 is a molecule that promotes an anti-inflammatory cellular phenotype in human primary macrophages, but this has not been proven in macrophages from patients with DM2 or DPN. Thus, we hypothesize that macrophages from patients with DM2 or DPN display an altered proinflammatory functional phenotype related to cytokine production and that the induction of CD163 expression will promote a more homeostatic phenotype by reducing their proinflammatory responsiveness.

PATIENTS AND METHODS

We tested these hypotheses in vitro using blood monocyte-derived macrophages from healthy subjects and patients with DM2 with and without DPN. Cells were incubated in the presence or the absence of 5 µg/mL of lipopolysaccharide (LPS). The concentrations of interleukin-10, interleukin-6, tumor necrosis factor-alpha (TNF-α), TGF-β, and monocyte chemoattractant protein-1 (MCP-1) were measured using ELISA assays. Macrophages were transfected with an empty vector plasmid or a plasmid containing the CD163 gene using mannosylated polyethylenimine nanoparticles.

RESULTS

Our results show that nonstimulated DM2 or DPN macrophages have a constitutive primed proinflammatory state and display a deficient production of proinflammatory cytokines upon a proinflammatory challenge when compared to healthy macrophages. CD163 induction produced an anti-inflammatory phenotype in the healthy control group, and this effect was partial in DM2 or DPN macrophages.

CONCLUSION

Our results suggest that diabetic macrophages adopt a complex phenotype that is only partially reversed by CD163 induction. Future experiments are focused on elucidating this differential responsiveness between healthy and diabetic macrophages.

Mitochondrial Impairment in Oligodendroglial Cells Induces Cytokine Expression and Signaling

Widespread inflammatory lesions within the central nervous system grey and white matter are major hallmarks of multiple sclerosis. The development of full-blown demyelinating multiple sclerosis lesions might be preceded by preactive lesions which are characterized by focal microglia activation in close spatial relation to apoptotic oligodendrocytes. In this study, we investigated the expression of signaling molecules of oligodendrocytes that might be involved in initial microglia activation during preactive lesion formation. Sodium azide was used to trigger mitochondrial impairment and cellular stress in oligodendroglial cells in vitro. Among various chemokines and cytokines, IL6 was identified as a possible oligodendroglial cell-derived signaling molecule in response to cellular stress. Relevance of this finding for lesion development was further explored in the cuprizone model by applying short-term cuprizone feeding (2-4 days) on male C57BL/6 mice and subsequent analysis of gene expression, in situ hybridization and histology. Additionally, we analyzed the possible signaling of stressed oligodendroglial cells in vitro as well as in the cuprizone mouse model. In vitro, conditioned medium of stressed oligodendroglial cells triggered the activation of microglia cells. In cuprizone-fed animals, IL6 expression in oligodendrocytes was found in close vicinity of activated microglia cells. Taken together, our data support the view that stressed oligodendrocytes have the potential to activate microglia cells through a specific cocktail of chemokines and cytokines among IL6. Further studies will have to identify the temporal activation pattern of these signaling molecules, their cellular sources, and impact on neuroinflammation.

Use of Measures of Inflammation and Kidney Function for Prediction of Atherosclerotic Vascular Disease Events and Death in Patients With CKD: Findings From the CRIC Study

RATIONALE & OBJECTIVE

Traditional risk estimates for atherosclerotic vascular disease (ASVD) and death may not perform optimally in the setting of chronic kidney disease (CKD). We sought to determine whether the addition of measures of inflammation and kidney function to traditional estimation tools improves prediction of these events in a diverse cohort of patients with CKD.

STUDY DESIGN

Observational cohort study.

SETTING & PARTICIPANTS

2,399 Chronic Renal Insufficiency Cohort (CRIC) Study participants without a history of cardiovascular disease at study entry.

PREDICTORS

Baseline plasma levels of biomarkers of inflammation (interleukin 1β [IL-1β], IL-1 receptor antagonist, IL-6, tumor necrosis factor α [TNF-α], transforming growth factor β, high-sensitivity C-reactive protein, fibrinogen, and serum albumin), measures of kidney function (estimated glomerular filtration rate [eGFR] and albuminuria), and the Pooled Cohort Equation probability (PCEP) estimate.

OUTCOMES

Composite of ASVD events (incident myocardial infarction, peripheral arterial disease, and stroke) and death.

ANALYTICAL APPROACH

Cox proportional hazard models adjusted for PCEP estimates, albuminuria, and eGFR.

RESULTS

During a median follow-up of 7.3 years, 86, 61, 48, and 323 participants experienced myocardial infarction, peripheral arterial disease, stroke, or death, respectively. The 1-decile greater levels of IL-6 (adjusted HR [aHR], 1.12; 95% CI, 1.08-1.16; P<0.001), TNF-α (aHR, 1.09; 95% CI, 1.05-1.13; P<0.001), fibrinogen (aHR, 1.07; 95% CI, 1.03-1.11; P<0.001), and serum albumin (aHR, 0.96; 95% CI, 0.93-0.99; P<0.002) were independently associated with the composite ASVD-death outcome. A composite inflammation score (CIS) incorporating these 4 biomarkers was associated with a graded increase in risk for the composite outcome. The incidence of ASVD-death increased across the quintiles of risk derived from PCEP, kidney function, and CIS. The addition of eGFR, albuminuria, and CIS to PCEP improved (P=0.003) the area under the receiver operating characteristic curve for the composite outcome from 0.68 (95% CI, 0.66-0.71) to 0.73 (95% CI, 0.71-0.76).

LIMITATIONS

Data for cardiovascular death were not available.

CONCLUSIONS

Biomarkers of inflammation and measures of kidney function are independently associated with incident ASVD events and death in patients with CKD. Traditional cardiovascular risk estimates could be improved by adding markers of inflammation and measures of kidney function.

High glucose induces a priming effect in macrophages and exacerbates the production of pro-inflammatory cytokines after a challenge

Introduction

Painful diabetic neuropathy is associated with chronic inflammation, in which macrophages are the key effectors. We utilized an in vitro approach to determine the effects of high glucose on macrophage phenotype.

Materials and methods

We exposed human THP-1 macrophages to normal glucose (5 mM) and a clinically relevant high glucose environment (15 mM) and measured the expression and concentration of molecules associated with a diabetic cellular phenotype.

Results

We found that THP-1 macrophages in high glucose conditions did not influence the basal expression of cyclooxygenase-2, Toll-like receptor-4, or class A scavenger receptor mRNA, or the concentrations of the cytokines interleukin (IL)-6, monocyte chemoattractant protein (MCP)-1, and IL-10, but induced a priming effect on tumor necrosis factor (TNF)-α. Then, we stimulated THP-1 macrophages with a strong pro-inflammatory stimulus lipopolysaccharide (LPS; 5 µg/mL). After stimulation with LPS, we observed an exacerbated increase in TNF-α, IL-6, and MCP-1 concentration in the high glucose condition compared to the normal glucose environment. THP-1 macrophages in high glucose conditions developed tolerance to IL-10 anti-inflammatory effects (TNF-α production) when challenged with LPS.

Conclusion

Our in vitro approach allows the study of macrophages as potential targets for therapeutic purposes since it compares them to primary human macrophages exposed to high glucose and macrophages from patients with diabetes or complications of painful diabetic neuropathy (i.e. ulcers, adipocytes, and pancreas).

Depression severity is associated with increased inflammation in veterans with peripheral artery disease

The present study examines the association between depressive symptoms and inflammatory markers in peripheral artery disease (PAD) to better understand the mechanistic relationship between depression and PAD. A cross-sectional sample of 117 patients with PAD (97% male, 76% Caucasian) was recruited from the San Francisco Veterans Affairs Medical Center. Patients were categorized into three subgroups based upon current depressive symptom severity, as defined by Patient Health Questionnaire-8 scores: no symptoms (score of 0-4, n = 62), mild symptoms (score of 5-9, n = 33), and moderate/severe symptoms (score ≥ 10, n = 22). Serum levels of high-sensitivity C-reactive protein (hs-CRP), interleukin-6 (IL-6), soluble intercellular adhesion molecule-1 (ICAM-1), and tumor necrosis factor-alpha (TNF-α) were assayed and log-transformed for multivariable analysis. To decrease the possibility of Type 1 errors, inflammatory markers were standardized and summed to create a total inflammatory score. In a multivariable analysis controlling for demographics, PAD severity, and atherosclerotic risk factors, mild and moderate/severe depressive symptoms were predictive of a higher total inflammatory score when compared to the group with no symptoms (mild symptoms p = 0.04, moderate/severe symptoms p = 0.007). Exploratory multivariable analyses of individual inflammatory markers found IL-6 levels were significantly higher in the moderate/severe symptoms group ( p = 0.006) than in the no symptoms group. Moreover, hs-CRP and ICAM-1 trended upwards with increasing depression severity. TNF-α was not associated with depression severity. We conclude that depressive symptom severity was independently associated with greater inflammation in PAD. Future research should examine the strength and directionality of this association through larger prospective cohort studies, as well as investigate the pathophysiological mechanisms responsible.

Metabolic syndrome, inflammation and atherothrombosis

Extensive research of the past decades altered our traditional concept about the genesis of atherosclerosis fundamentally. Today, the crucial role of inflammation in the formation and progression of atherosclerotic plaques is indisputable. Patients at high risk for developing cardiovascular disease, owing to poor diet, obesity and low physical activity have been shown to exhibit a particular inflammatory pattern.

Therefore, the present review highlights the crosslink between the metabolic syndrome (MetS), adipose tissue, adipokines and selected inflammatory cytokines in the context of atherothrombosis and cardiovascular disease.

An Interleukin-6 Receptor Antibody Suppresses Atherosclerosis in Atherogenic Mice

IκBNS is a nuclear IκB protein which negatively regulates nuclear factor-κB activity. We demonstrated that IκBNS deficiency accelerates atherosclerosis in LDL receptor-deficient (LDLr^-/-) mice via increased interleukin (IL)-6 production by macrophages. Previous studies showed that the increase in IL-6 might contribute to the development of atherosclerotic lesions. However, whether an anti-mouse IL-6 receptor antibody (MR16-1) can protect atherosclerotic lesions in atherogenic mice remains to be elucidated. We investigated atherosclerotic lesions in LDLr^-/- and IκBNS^-/-/LDLr^-/- mice after 16 weeks consumption of a high-fat diet. All mice received intraperitoneal injections of MR16-1 or phosphate-buffered saline (PBS) (control) once a week during a high-fat diet consumption. Treatment of MR16-1 yielded no adverse systemic effects, and we detected no significant differences in serum cholesterol levels in either group. The atherosclerotic lesions were significantly increased in IκBNS^-/-/LDLr^-/- compared with LDLr^-/- mice (p < 0.01) under treatment of PBS. However, MR16-1 treatment abolished the significant difference of atherosclerotic lesions between IκBNS^-/-/LDLr^-/- and LDLr^-/- mice. Interestingly, MR16-1 also significantly decreased atherosclerotic lesions in LDLr^-/- mice compared with PBS treatment (p < 0.05). Immunostaining revealed percent phospho-STAT3-positive cell were significantly decreased in the atherosclerotic lesions of MR16-1 treated both IκBNS^-/-/LDLr^-/- and LDLr^-/- mice compared with PBS-treated mice, indicating MR16-1 could suppress atherosclerotic lesions via the inhibition of IL-6-STAT3 signaling pathway. This study highlights the potential therapeutic benefit of anti-IL-6 therapy in preventing atherogenesis induced by dyslipidemia and/or inflammation.

The influence of low-grade inflammation on platelets in patients with stable coronary artery disease

Inflammation is likely to be involved in all stages of atherosclerosis. Numerous inflammatory biomarkers are currently being studied, and even subtle increases in inflammatory biomarkers have been associated with increased risk of cardiovascular events in patients with coronary artery disease (CAD). Low-grade inflammation may influence both platelet production and platelet activation potentially leading to enhanced platelet aggregation. Thrombopoietin is considered the primary regulator of platelet production, but it likely acts in conjunction with numerous cytokines, of which many have altered levels in CAD. Previous studies have shown that high-sensitive C-reactive protein (CRP) independently predicts increased platelet aggregation in stable CAD patients. Increased levels of CRP, fibrinogen, interleukin-6, stromal cell-derived factor-1, CXC motif ligand 16, macrophage migration inhibitory factor, RANTES, calprotectin, and copeptin have been associated with increased risk of cardiovascular events in CAD patients. Additionally, some of these inflammatory markers have been associated with enhanced platelet activation and aggregation. However, CRP and other inflammatory markers provide only limited additional predictive value to classical risk factors such as smoking, blood pressure, and cholesterol levels. Existing data do not clarify whether inflammation simply accompanies CAD and increased production and aggregation of platelets, or whether a causal relationship exists. In this review, we provide a comprehensive overview of inflammatory markers in stable CAD with particular emphasis on platelet production, activation, and aggregation in CAD patients.

Cytokines and MicroRNA in Coronary Artery Disease

Cardiovascular disease (CVD) is a major health problem globally. The high incidence and case fatality of CVD are, to a large extent, a consequence of its late diagnosis and lack of highly sensitive and specific markers. Only a very small number of biomarkers, such as troponin, detect late disease. There is some evidence of an association and dysregulation between specific cytokines in the pathogenesis of CVD. These molecules are involved in inflammatory and immune mechanisms associated with atherogenesis. Several molecular/cellular pathways that include STAT, MAPK, and SMAD are modulated by cytokines. Against this background, microRNAs (miRNAs) are a class of noncoding RNAs with important roles in pathological events, leading to atherosclerotic CVD. It has been shown that the latter could affect cytokine production and contribute to progression of atherosclerotic CVD. Moreover, modulation of miRNAs appears to inhibit cardiomyocyte apoptosis, attenuate infarct size, and reduce cardiac dysfunction. This review highlights several recent preclinical and clinical studies on the role of cytokines in CVD, novel miRNA-based therapeutic approaches for therapeutic intervention, and potential circulating cytokines that have promise as biomarkers in CVD.

Benzo[a]pyrene activates interleukin-6 induction and suppresses nitric oxide-induced apoptosis in rat vascular smooth muscle cells

Benzo[a]pyrene, a ubiquitous environmental pollutant, has been suggested to be capable of initiating and/or accelerating atherosclerosis. Accumulation of vascular smooth muscle cells (VSMCs) in vessel intima is a hallmark of atherosclerosis. Nitric oxide (NO) can suppress VSMCs proliferation and induce VSMCs apoptosis. NO plays a compensatory role in the vascular lesions to reduce proliferation and/or accelerate apoptosis of VSMCs. The aim of this study was to investigate whether benzo[a]pyrene can affect VSMCs growth and apoptosis induced by NO. Benzo[a]pyrene (1–30 μmol/L) did not affect the cell number and cell cycle distribution in VSMCs under serum deprivation condition. Sodium nitroprusside (SNP), a NO donor, decreased cell viability and induced apoptosis in VSMCs. Benzo[a]pyrene significantly suppressed SNP-induced cell viability reduction and apoptosis. VSMCs cultured in conditioned medium from cells treated with benzo[a]pyrene could also prevent SNP-induced apoptosis. Benzo[a]pyrene was capable of inducing the activation of nuclear factor (NF)-κB and phosphorylation of p38 mitogen-activated protein kinase (MAPK) in VSMCs. Both NF-κB inhibitor and p38 MAPK inhibitor significantly reversed the anti-apoptotic effect of benzo[a]pyrene on SNP-treated VSMCs. Incubation of VSMCs with benzo[a]pyrene significantly and dose-dependently increased interleukin (IL)-6 production. A neutralizing antibody to IL-6 effectively reversed the anti-apoptotic effect of benzo[a]pyrene on SNP-treated VSMCs. Taken together, these results demonstrate for the first time that benzo[a]pyrene activates IL-6 induction and protects VSMCs from NO-induced apoptosis. These findings propose a new mechanism for the atherogenic effect of benzo[a]pyrene.

Renal Calcium Oxalate Deposits Induce a Pro-Atherosclerotic and Pro-Osteoporotic Response in Mice

Urinary stone disease (USD) is increasing in adult and pediatric populations. Adult and pediatric studies have demonstrated decreased bone mineral density and increased fracture rates. USD has also been independently linked to increased rates of myocardial infarction and cerebral vascular accidents. Although USD is a multisystem disorder involving the kidneys, bone, and vasculature, the molecular mechanisms linking these three organs remain unknown. Calcium oxalate nephropathy was induced in C57BL/6J mice with intra-peritoneal (ip) injection of sodium glyoxolate. Half of each kidney underwent Pizzalato staining and half was snap frozen for RNA extraction. RT² Profiler Mouse Atherosclerosis, Osteoporosis, and Calcium Signaling PCR Arrays (Qiagen) were performed. Only results that passed quality checks in PCR array reproducibility and genomic DNA contamination were included. Genes had to show at least fourfold differential expression and P < 0.01 to be considered significant. Atherosclerosis array showed upregulation of 19 genes by fourfold, 10 of which were ≥10-fold. All 19 had P ≤ 0.002. The Osteoporosis array showed fourfold upregulation of 10 genes, five showed >10-fold increase. All 10 have P ≤ 0.003. The calcium signaling array showed significant fourfold upregulation of 10 genes, four of which were ≥10-fold. All 10 have P ≤ 0.03. We have demonstrated that calcium oxalate nephropathy can induce upregulation of atherosclerotic, metabolic bone, and calcium homeostasis genes in a murine model. This may be and initial step in identifying the molecular mechanisms linking stone, bone, and cardiovascular disease. J. Cell. Biochem. 118: 2744-2751, 2017. © 2017 Wiley Periodicals, Inc.

Transplantation of Autologous Bone Marrow Mononuclear Cells Regulates Inflammation in a Rabbit Model of Carotid Artery Atherosclerosis

OBJECTIVE

It is well known that inflammation plays key roles in the development of atherosclerosis and that the transplantation of bone marrow mononuclear cells (BMMNCs) can suppress inflammation in rodent models of ischemic diseases. Here, we explored whether transplantation of autologous BMMNCs could prevent the progression of atherosclerosis by the alleviation of inflammatory responses in a rabbit model of carotid artery atherosclerosis.

METHODS AND RESULTS

The atherosclerotic rabbit model was established by air desiccation followed by a high-cholesterol diet for 8 weeks. Then, 1 × 107 BMMNCs labeled with BrdU or an equal volume of vehicle were injected into the rabbits via the ear vein. Using an ultrasonographic imaging method, we found that autologous BMMNC treatment significantly decreased the area of atherosclerotic plaques compared to the vehicle-treated group (p < 0.05). The results were further confirmed by hematoxylin-eosin staining. RT-PCR results demonstrated that BMMNC treatment significantly reduced the expression of interleukin (IL)-6 and CD147 but increased the expression of IL-10 and transforming growth factor-β compared with vehicle treatment (p < 0.05), which was consistent with Western blot results.

CONCLUSIONS

Transplantation of autologous BMMNCs delays the development of atherosclerosis, most probably via the attenuation of inflammatory responses, which could be a new approach for treating carotid atherosclerosis.

Relationship between Interleukin-6 (-174G/C and -572C/G) Promoter Gene Polymorphisms and Risk of Intracerebral Hemorrhage: A Meta-Analysis

BACKGROUND

Polymorphisms of -174G/C and -572C/G in the Interleukin-6 (IL-6) promoter gene can affect both transcription and secretion of IL-6 and may be involved in the inflammatory mechanisms in early and delayed phases after intracerebral hemorrhage (ICH). The role of these polymorphisms remains unclear for the pathogenesis of ICH.

METHODS

PubMed, EMBASE, MEDLINE and Google Scholar searches were conducted from January 1, 1950 to February 29, 2016 and were supplemented with relevant articles identified in the references. The following search terms were used: ('interleukin-6' or 'IL-6') and ('genetic polymorphism' or 'single nucleotide polymorphisms' or 'SNP') and ('intracerebral hemorrhage' or 'ICH') and ('hemorrhagic stroke' or 'HS'). Fixed or random effects models were used to estimate the pooled odds ratios and 95% confidence intervals. Begg's funnel plot was used to assess the potential for publication bias.

RESULTS

In our meta-analysis, three case-control studies involving 446 ICH cases and 2,322 controls were included. No significant association was observed for the IL-6 (-174G/C and -572C/G) gene polymorphisms with the risk of ICH under dominant, recessive and allelic models.

CONCLUSION

Our meta-analysis suggests that IL-6 gene polymorphisms are not associated with the risk of ICH. However, caution must be taken while considering the results of our meta-analysis due to the presence of small sample size. Our results cannot be extrapolated to represent the effect of entire IL-6 genetic polymorphism on stroke patients worldwide. Therefore, further well-designed studies with large sample size are warranted to validate our findings and provide a profound conclusion.

Innate immunity and atherogenesis

Atherosclerosis is recognized as the pathological basis of cardiovascular disease (CVD) and recent advances in basic science have shown that it should be considered as a chronic inflammatory process. Both elements of the innate and the adaptive immunity appear to be actively involved in atherogenesis. In fact, the potential role played by pattern-recognition receptors (Toll-like receptors and scavenger receptors), cytokines (such as IL-1, IL-6, TNFa), chemokines and pentraxines (such as CRP and PTX3) represents an emerging field of investigation in atherogenesis. In the near future we expect a better definition of the real biological and clinical impact on CVD of these mediators. On one side, they could become useful to complement traditional risk factors, in order to identify new categories of subjects prone to CVD development. On the other, they could become an additional potential target for therapeutic strategies.

Genetic Variation in NFKB1 and NFKBIA and Susceptibility to Coronary Artery Disease in a Chinese Uygur Population

OBJECTIVES

Coronary artery disease (CAD) is the most common chronic inflammatory disease worldwide. NF-κB, a central regulator of inflammation, is involved in various inflammatory diseases. The aim of this study was to investigate the association between NFKB1 and NFKBIA polymorphisms and the susceptibility to CAD and their impact on plasma levels of IL-6 in a Chinese Uygur population.

METHODS

We genotyped NFKB1-94ins/del ATTG (rs28362491) and NFKBIA3' UTR A/G (rs696) using TaqMan SNP genotyping assays in 960 Uygur CAD cases and Uygur 1060 CAD-negative controls. IL-6 plasma levels were measured in 360 stable angina pectoris (SAP) cases and 360 controls using ELISA method.

RESULTS

There was no significant difference in the distribution of the genotypes and alleles of rs696 polymorphism in CAD cases and controls. Significant difference in the frequency of genotypes (P = 0.001) and alleles (P = 0.001) of rs28362491 polymorphism was observed in CAD cases compared to controls. In multivariate logistic regression analysis, SNP rs28362491 was consistently associated with CAD risk in a recessive model after adjustment for cardiovascular risk factors (OR = 1.581, 95% CI 1.222 to 2.046, P<0.001). SAP cases had significantly higher plasma levels of IL-6 compared to controls (P<0.001). General linear model analysis showed rs28362491 was independently associated with increased IL-6 levels by analyses of a recessive model (P<0.001) after adjustment for covariates.

CONCLUSIONS

Our study indicates that NFKB1-94 ins/del ATTG polymorphism may play a role in CAD susceptibility in Chinese Uygur population and is functionally associated with IL-6 expression, suggesting a mechanistic link between NFKB1-94 ins/del ATTG polymorphism and CAD susceptibility.

Does Inflammation Have a Role in the Pathogenesis of Cardiac Syndrome X? A Genetic-Based Clinical Study With Assessment of Multiple Cytokine Levels

We compared Turkish patients with cardiac syndrome X (CSX) and controls with respect to serum pro- and anti-inflammatory cytokine levels, as well as the single-nucleotide polymorphisms located in the promoter regions of their related genes. This study included 111 consecutive patients angiographically diagnosed with CSX and 111 healthy controls with similar demographic characteristics. Serum interleukin (IL) 6, tumor necrosis factor α (TNF-α), and IL-10 levels were measured, and the genotypes of the patients and controls were determined using standard methods. Serum IL-6 and IL-10 levels were significantly higher in the CSX group than in the control group ( P < .01, respectively). Serum TNF-α level was lower in the CSX group than in the control group ( P < .001). On the other hand, participants with CSX and healthy controls were not significantly different with respect to the genotype distributions of IL-6, TNF-α, and IL-10 genes. As a result of our study, both pro-inflammatory and anti-inflammatory cytokines may play a role in the pathogenesis of CSX. In contrast, the studied gene polymorphisms did not influence CSX pathogenesis.

A Novel ASK Inhibitor AGI-1067 Inhibits TLR-4-Mediated Activation of ASK1 by Preventing Dissociation of Thioredoxin from ASK1

The cell type that normally limits the inflammatory and atherosclerotic process is the vascular endothelial cell (EC) that can be regulated by proinflammatory and various stresses. Toll-like receptor-4 (TLR4) plays an important role in the pathogenesis of atherosclerosis, in part, by activating apoptosis signal-regulating kinase 1 (ASK1) to initiate the activation of MAP kinases pathways and the expression of inflammatory genes. In the present study, we test the hypothesis that AGI-1067 acts as an anti-inflammatory agent by inhibiting the activation of ASK1 in human EC. Pretreatment of human aortic endothelial cells with AGI-1067 inhibits TLR4 ligand (LPS)-induced activation of ASK1 and the downstream p38 and c-Jun N-terminal kinase (JNK) MAP kinases. LPS dissociates two endogenous inhibitors thioredoxin-1 (Trx1) and 14-3-3 from ASK1, leading to ASK1 autoactivation. Interestingly, AGI-1067 inhibits the dissociation of Trx1, but not 14-3-3, from ASK1. However, inhibition of Trx1 dissociation from ASK1 by AGI-1067 is sufficient to suppress LPS-mediated phosphorylation of the transcription factors c-Jun and activating transcription factor 2, and inhibit LPS-induced inflammatory genes including vascular cell adhesion molecule 1, E-selectin, IL-6 and monocyte chemoattractant protein 1. Our findings suggest that AGI-1067 as a unique ASK1 inhibitor to inhibit TLR4-mediated ASK1 activation, contributing to its anti-inflammatory properties.

Human cytomegalovirus-encoded pUL7 is a novel CEACAM1-like molecule responsible for promotion of angiogenesis

Persistent human cytomegalovirus (HCMV) infection has been linked to several diseases, including atherosclerosis, transplant vascular sclerosis (TVS), restenosis, and glioblastoma. We have previously shown that factors secreted from HCMV-infected cells induce angiogenesis and that this process is due, at least in part, to increased secretion of interleukin-6 (IL-6). In order to identify the HCMV gene(s) responsible for angiogenesis promotion, we constructed a large panel of replication-competent HCMV recombinants. One HCMV recombinant deleted for UL1 to UL10 was unable to induce secretion of factors necessary for angiogenesis. Fine mapping using additional HCMV recombinants identified UL7 as a viral gene required for production of angiogenic factors from HCMV-infected cells. Transient expression of pUL7 induced phosphorylation of STAT3 and ERK1/2 MAP kinases and production of proangiogenic factors, including IL-6. Addition of recombinant pUL7 to cells was sufficient for angiogenesis and was again associated with increased IL-6 expression. Analysis of the UL7 structure revealed a conserved domain similar to the immunoglobulin superfamily domain and related to the N-terminal V-like domain of carcinoembryonic antigen-related cell adhesion molecule 1 (CEACAM1). Our report therefore identifies UL7 as a novel HCMV-encoded molecule that is both structurally and functionally related to cellular CEACAM1, a proangiogenic factor highly expressed during vasculogenesis.

IMPORTANCE

A hallmark of cytomegalovirus (CMV) infection is its ability to modulate the host cellular machinery, resulting in the secretion of factors associated with long-term diseases such as vascular disorders and cancer. We previously demonstrated that HCMV infection alters the types and quantities of bioactive proteins released from cells (designated the HCMV secretome) that are involved in the promotion of angiogenesis and wound healing. A key proangiogenic and antiapoptotic factor identified from a proteomic-based approach was IL-6. In the present report, we show for the first time that HCMV UL7 encodes a soluble molecule that is a structural and functional homologue of the CEACAM1 proangiogenic cellular factor. This report thereby identifies a critical component of the HCMV secretome that may be responsible, at least in part, for the vascular dysregulation associated with persistent HCMV infection.

Dynamic interplay between metabolic syndrome and immunity

Obesity and its co-morbidities as metabolic syndrome, type 2 diabetes mellitus and cardiovascular diseases are major health problems worldwide. Several reports indicated that nutrient excess and metabolic syndrome are linked with altered immune response. Indeed, metabolic syndrome is characterized by insulin resistance and chronic low-grade inflammation, which conditions are the consequences of the complex interaction between adipocytes and immune cells. Enlarged white adipose tissue is infiltrated by immune cells and secretes various bioactive substances, like adipokines, cytokines and other inflammatory mediators. Due to its special architecture in which metabolic and immune cells are in intimate proximity, metabolic and immunologic pathways are closely integrated in adipose tissue. With the contribution of altered gut microbiota, adipokines and cytokines modulate insulin signaling and immune response leading to adipose tissue inflammation and systemic insulin resistance. In this chapter, we focus on the cellular and molecular mechanisms that lead to impaired insulin sensitivity and chronic low-grade inflammation in obesity. We also detail the potential role of adipokines and immune cells in this deleterious process, and the concerns of vaccination in metabolic syndrome. Finally, we address the links between obesity and gut microbiota as an emerging new field of interest, and scratch the surface of potential therapeutic opportunities.