Novel anti-inflammatory strategies in atherosclerosis

Association between composite dietary antioxidant index and atherosclerosis cardiovascular disease in adults: A cross-sectional study

BACKGROUND AND AIM

The objective of our study was to examine the association between composite dietary antioxidant index (CDAI) and atherosclerotic cardiovascular disease (ASCVD) in adults.

METHODS AND RESULTS

Data was gathered from the National Health and Nutrition Examination Survey (NHANES) between 2001 and 2018. To examine the connection between CDAI and ASCVD, multiple logistic regression analyses were performed. Restricted cubic splines were utilized to examine non-linear correlations, and the inflection point was identified using a two-piecewise linear regression approach. Subgroup analyses were performed to demonstrate stability of results. A total of 44,494 individuals were included in the study. The multivariate logistic regression model was fully adjusted and revealed an odds ratio of 0.968 (95% CI: 0.959-0.978; P < 0.001) for the correlation between CDAI and ASCVD. Furthermore, individuals in the highest quartile of CDAI exhibited a decreased risk of ASCVD compared to those in the lowest quartile [0.716 (0.652-0.787); P < 0.001]. Moreover, restricted cubic spline (RCS) analysis revealed non-linear relationship between CDAI and ASCVD, with inflection point at -0.387. The analysis of subgroups showed that the importance of CDAI remained consistent among various age, sex, race, body mass index (BMI), and physical activity.

CONCLUSIONS

Our research revealed an inverse and non-linear relationship between CDAI and ASCVD in adults. The implications of these findings are significant for future studies and the formulation of dietary guidelines.

Potential of natural products in inflammation: biological activities, structure-activity relationships, and mechanistic targets

A balance between the development and suppression of inflammation can always be found in the body. When this balance is disturbed, a strong inflammatory response can damage the body. It sometimes is necessary to use drugs with a significant anti-inflammatory effect, such as nonsteroidal anti-inflammatory drugs and steroid hormones, to control inflammation in the body. However, the existing anti-inflammatory drugs have many adverse effects, which can be deadly in severe cases, making research into new safer and more effective anti-inflammatory drugs necessary. Currently, numerous types of natural products with anti-inflammatory activity and distinct structural features are available, and these natural products have great potential for the development of novel anti-inflammatory drugs. This review summarizes 260 natural products and their derivatives with anti-inflammatory activities in the last two decades, classified by their active ingredients, and focuses on their structure-activity relationships in anti-inflammation to lay the foundation for subsequent new drug development. We also elucidate the mechanisms and pathways of natural products that exert anti-inflammatory effects via network pharmacology predictions, providing direction for identifying subsequent targets of anti-inflammatory natural products.

Mechanisms of Xiong-Pi-Fang in treating coronary heart disease associated with depression: A systematic pharmacology strategy and in vivo pharmacological validation

BACKGROUND

Coronary heart disease (CHD) and depression are very common and often co-existing disorders. Xiong-Pi-Fang (XPF), a therapeutic classical traditional Chinese medicine (TCM) formula, has shown satisfactory efficacy in treating CHD associated with depression. However, its mechanism of action is still unknown.

PURPOSE

To employ a systematic pharmacology approach for identifying the action mechanisms of XPF in treating CHD associated with depression.

METHODS

We used a systematic pharmacology approach to identify the potential active mechanisms of XPF in treating CHD with depression. Potential active compounds in XPF and the diseases targets were screened using relevant databases to build corresponding pathways, following the experiments that were conducted to confirm whether the presumptive results of systemic pharmacology were correct.

RESULTS

Network pharmacology predicted 42 key targets and 20 signaling pathways involved in XPF-mediated treatment, with IL-6/JAK2/STAT3/HIF-1α/VEGF-A pathway significantly affected. The common influences were hypothalamic-pituitary-adrenal axis (HPA axis) and glucocorticoid signaling, validated through chronic unexpected mild stress (CUMS) with isoprenaline (ISO) for inducing CHD within the depression model in rats. In addition, XPF intake reduced depressive-like behaviors and improved ECG ischemic changes. Furthermore, XPF exerted some anti-inflammatory effects by inhibiting the interleukin-6 (IL-6) induced phosphorylation of janus kinase 2 (JAK2) and signal transducer and activator of transcription 3 (STAT3), ultimately downregulating hypoxia-inducible factor 1-α (HIF-1α) and vascular endothelial growth factor-A (VEGF-A) activation. The dysfunctional HPA axis feedback loop was also regulated, which enhanced the glucocorticoid receptor (GR) expression. In contrast, it improved glucocorticoid resistance by reducing the mineralocorticoid receptor expression.

CONCLUSIONS

Suppressing IL-6 release and maintaining the HPA feedback loop balance could be the primary mechanism of XPF against CHD with depression. The significance of the IL-6 and HPA axis identified indicates their potential as essential targets for CHD therapy with depression.

Association of the systemic immune-inflammation index with all-cause mortality in patients with arteriosclerotic cardiovascular disease

Objective

Systemic immune-inflammation index (SII), derived from blood cell counts of circulating platelets, neutrophils, and lymphocytes, has been identified as a novel inflammatory and prognostic marker. However, the clinical value of SII in patients with arteriosclerotic cardiovascular disease (ASCVD) had not been further explored. Thus, this study is designed to explore the associations of SII with mortality in ASCVD individuals.

Methods

All individuals with ASCVD aged ≥20 years were included from the National Health and Nutritional Examination Surveys (NHANES) 2005–2014 and followed for survival until 31 December 2019. Multivariable Cox analysis investigated the associations between SII, evaluated as a continuous variable with splines, as categorical ones (quartiles), and the all-cause death. To demonstrate the association between SII and mortality, subgroup analysis, restricted cubic spline along with piecewise linear regression were also conducted.

Results

A total of 2,595 participants (57.8% men) were included. During a median of 7.7 years of follow-up, 1,122 deaths due to all-cause were recorded. After adjusting for multiple confounders, when compared with the patients in quartile 1 (SII ln transform), those in quartile 4 had a 46% increased risk for all-cause death [hazard ratio (HR) = 1.46, 95% confidence interval (CI) = 1.22–1.75]. As a continuous variable, each unit of raised ln-SII was associated with a 24% increased risk of all-cause death (HR = 1.24, 95% CI = 1.10–1.38). In the restricted cubic spline regression model, the relationship between ln-SII and all-cause death was non-linear. The cutoff value of ln-SII for mortality was 6.57 and those with a higher than the threshold point had a 1.25-fold risk of mortality. No significant difference was noted below the threshold points.

Conclusion

An association was detected between the baseline ln-SII and all-cause mortality in a United States ASCVD population. Increased SII is associated with poor survival in individuals with ASCVD.

The Role of Plasma Interleukin-6 Levels on Atherosclerotic Cardiovascular Disease and Cardiovascular Mortality Risk Scores in Javanese Patients with Chronic Kidney Disease

Interleukin-6 (IL-6) has been identified as an important pro-inflammatory factor involved in mediating the severity of chronic kidney disease (CKD). This study sought to determine the effect of plasma IL-6 levels on atherosclerotic cardiovascular disease (ASCVD) and cardiovascular mortality risk scores in Javanese CKD patients. We also analyzed the frequency of IL-6 G174C single nucleotide polymorphism (SNP) in the population. This study was a cross-sectional study involving seventy-three patients of Javanese ethnic origin with stable chronic kidney disease. We assessed the ASCVD risk score, cardiovascular mortality score, genotyping of IL-6 G174C SNP, and plasma IL-6 levels in these patients. The genotype distribution and allele frequencies of the IL-6 G174C SNP were predominated by the G genotype/allele (GG: 97.26%, GC: 1.37%, CC: 1.37%, G-allele: 97.95%, and C-allele: 2.05%). Despite the fact that plasma IL-6 levels did not directly affect cardiovascular mortality risk, further analysis revealed its direct effect on the ASCVD risk score (path coefficient = 0.184, p = 0.043, 95% CI = 0.018−0.380), which in turn affected cardiovascular mortality risk (path coefficient = 0.851, p = <0.01, 95% CI = 0.714−0.925). In conclusion, plasma IL-6 levels play important roles on ASCVD risk and cardiovascular mortality risk in Javanese patients with CKD.

Ten-year atherosclerosis cardiovascular disease (ASCVD) risk score and its components among an Iranian population: a cohort-based cross-sectional study

BACKGROUND

Atherosclerotic cardiovascular disease (ASCVD) continues to be the first cause of mortality globally. Effective preventive strategies require focused efforts to clarify ASCVD risk factors in different subgroups of a population. This study aimed to identify individuals at higher risk of ASCVD among Shiraz University employees to guide decision-making for primary prevention.

METHODS

This cohort-based cross-sectional study was conducted on data of 1191 participants (25-70 years old) from Shiraz University employees selected by systematic random sampling. The 10-year ASCVD risk was calculated with an ASCVD risk score estimator developed by the American College of Cardiology/American Heart Association (ACC/AHA). To analyze the data, descriptive and chi-square tests were used. All statistical analyses were conducted using the SPSS version 16.0 software. The p-value < 0.05 was considered a significant level.

RESULTS

This study demonstrated that 75.3% of the participants had low risk scores, whereas 13.2% and 2.5% of them had intermediate and high risk scores, respectively. Additionally, it revealed that among women 93.7%, 2.7%, and 0.6% had low intermediate and had high risk scores, respectively, whereas among men, 61.5%, 21.1%, and 3.9% had low intermediate and high risk scores, respectively. Based on the results of the chi-square test, men were significantly more prone to ASCVD (38.5%) than women (6.3%) were. Interestingly, 40.9% of known cases of hypertension had uncontrolled blood pressure, and 62.5% of individuals without any history of hypertension, who were considered new cases of hypertension, had abnormal blood pressure. Furthermore, 38.5% of diabetic patients and 1.6% of people who did not have a history of diabetes had abnormal serum fasting blood sugar.

CONCLUSION

It was revealed that nearly 15.7% of participants were at intermediate and high risk of developing ASCVD in the next 10 years with greater risk in men. Considerably, some of hypertensive and diabetic participants had uncontrolled blood pressure and blood sugar levels, respectively. New cases of diabetes and hypertension were also recognized in our study. Therefore, to address the primary prevention of ASCVD in this population, it is necessary to have plans for targeted interventions, which can be effective in modifying their risk factors.

The Cholinergic Anti-Inflammatory Pathway Attenuates the Development of Atherosclerosis in Apoe-/- Mice through Modulating Macrophage Functions

(1) Background: The cholinergic anti-inflammatory pathway (CAP) has been implicated in the regulation of various diseases, including chronic inflammatory cardiovascular disorders such as atherosclerosis (AS). This study aims to explore the underlying regulatory mechanisms of CAP activity in the progression of AS. (2) Methods: The Apoe^-/- mice were subjected to sham, bilateral cervical vagotomy surgery (VGX), and VGX supplemented with Gainesville Tokushima scientists (GTS)-21 (4 mg/kg/d) and then fed with a high-fat diet for 10 weeks. Atherosclerotic lesion size and inflammation levels were investigated by histology and inflammatory cytokines analysis. The blood M1/M2 macrophages were analyzed by flow cytometry. Primary mouse bone marrow-derived macrophages (BMDM), peritoneal macrophages, and RAW264.7 cells were treated with CAP agonists acetylcholine (Ach) and GTS-21 to study their effects on macrophage functions. (3) Results: Compared with the sham group, inhibition of CAP by the VGX resulted in growing aortic lipid plaque area, deteriorated inflammatory levels, and aberrant quantity of M1/M2 macrophages in Apoe^-/- mice. However, these detrimental effects of VGX were significantly ameliorated by the reactivation of CAP through GTS-21 treatment. The in vitro study using macrophages revealed that stimulation with CAP agonists suppressed M1, but promoted M2 macrophage polarization through the upregulation of TNFAIP3 and phosphorylation STAT3 levels, respectively. Moreover, the activation of CAP inhibited the formation of macrophage foam cells in the peritoneal cavity by regulating genes related to cholesterol metabolism. (4) Conclusions: This study provides novel evidence and mechanisms that the CAP plays an important role in the regulation of AS development by controlling macrophage functions, implying a potential use of CAP activation as a therapeutic strategy for AS treatment.

Neutrophil-lymphocyte ratio predicts disease severity and outcome after lower extremity procedures

OBJECTIVE

Neutrophil-lymphocyte ratio (NLR) has been associated with inferior outcomes after lower extremity interventions. NLR has been associated with systemic inflammation and atherosclerotic burden. We examined NLR, severity of peripheral artery disease (PAD), and outcomes after endovascular or open surgical procedures.

METHODS

Inpatients undergoing lower extremity procedures (2008-2016) were selected from Cerner Health Facts database (Cerner Corporation, North Kansas City, Mo) using International Classification of Diseases, Ninth Revision procedure codes. Disease severity was grouped into claudication, rest pain, and tissue loss. Outcomes were identified using International Classification of Diseases, Ninth Revision codes. NLR was calculated preoperatively and postoperatively. A χ² analysis and multivariable logistic regression were performed. A receiver operating characteristic curve analysis was used to determine the cutoff for preoperative (low, <3.65; high, ≥3.65) and postoperative (low, <5.96; high, ≥5.96) NLR values.

RESULTS

There were 3687 patients evaluated; 2183 (59%) underwent endovascular procedures and 1504 (41%) had open procedures. Compared with black patients, claudication was more frequent in white patients (81.7% vs 72.7%; P < .0001), and tissue loss was less common (12.9% vs 20.9%; P < .0001). NLR values were higher for patients with tissue loss than for patients with rest pain or claudication (4.89, 4.33, and 3.11, respectively; P < .0001). Open procedures were associated with higher postoperative NLR values than endovascular procedures (6.8 vs 5.2; P < .0001). Mean preoperative and postoperative NLR values were greater in patients with more severe PAD. Multivariable analysis demonstrated that preoperative high NLR was strongly associated with in-hospital death (odds ratio [OR], 5.4; 95% confidence interval [CI], 1.68-17.07), cardiac complications (OR, 2.9; 95% CI, 1.57-5.40), amputation (OR, 2.5; 95% CI, 1.65-3.87), renal failure (OR, 1.9; 95% CI, 1.18-2.93), respiratory complications (OR, 1.7; 95% CI, 1.09-2.76), and prolonged length of stay (OR, 1.9; 95% CI, 1.89-3.71).

CONCLUSIONS

Preoperative and postoperative NLR significantly increases with disease severity for PAD, providing further evidence of NLR as a biomarker of a patient's systemic inflammatory state. After adjustment for confounders, NLR still remained strongly associated with death and other adverse outcomes after intervention for PAD. Further study of the clinical association of NLR with other vascular disorders, such as symptomatic carotid stenosis and symptomatic and ruptured aortic aneurysmal disease, is planned to guide individualized treatment to prevent stroke or aneurysm rupture.

Knockdown of GAS5 Inhibits Atherosclerosis Progression via Reducing EZH2-Mediated ABCA1 Transcription in ApoE-/- Mice

Atherosclerosis is a disorder occurring in the large arteries and the primary cause of heart diseases. Accumulating evidence has implicated long non-coding RNAs (lncRNAs) in atherosclerosis. This study aims to clarify the potential effects of lncRNA growth arrest-specific 5 (GAS5) on cholesterol reverse-transport and intracellular lipid accumulation in atherosclerosis. GAS5 was mainly localized in the nucleus and highly expressed in the human monocytic leukemia cell line (THP-1) macrophage-derived foam cells in coronary heart disease. Overexpressed GAS5 increased THP-1 macrophage lipid accumulation. Of note, GAS5 can inhibit the expression of ATP-binding cassette transporter A1 (ABCA1) by binding to enhancer of zeste homolog 2 (EZH2). Overexpression of EZH2 reduced cholesterol efflux and ABCA1 expression. EZH2 promoted triple methylation of lysine 27 (H3K27) in the ABCA1 promoter region. Subjected to overexpressed GAS5, overexpressed EZH2, or downregulated ABCA1, the Apolipoprotein E (ApoE)^−/− mice with atherosclerosis showed increased total cholesterol (TC), free cholesterol (FC), cholesterol ester (CE), low-density lipoprotein (LDL) levels, aortic plaque, and lipid accumulation, accompanied by reduced high-density lipoprotein (HDL) level and cholesterol outflow. Altogether, knockdown of GAS5 can potentially promote reverse-transportation of cholesterol and inhibit intracellular lipid accumulation, ultimately preventing the progression of atherosclerosis via reducing EZH2-mediated transcriptional inhibition of ABCA1 by histone methylation.

IL-37 Expression Reduces Lean Body Mass in Mice by Reducing Food Intake

The human cytokine interleukin (IL)-37 is an anti-inflammatory member of the IL-1 family of cytokines. Transgenic expression of IL-37 in mice protects them from diet-induced obesity and associated metabolic complications including dyslipidemia, inflammation and insulin resistance. The precise mechanism of action leading to these beneficial metabolic effects is not entirely known. Therefore, we aimed to assess in detail the effect of transgenic IL-37 expression on energy balance, including food intake and energy expenditure. Feeding homozygous IL-37 transgenic mice and wild-type (WT) control mice a high-fat diet (HFD; 45% kcal palm fat) for 6 weeks showed that IL-37 reduced body weight related to a marked decrease in food intake. Subsequent mechanistic studies in mice with heterozygous IL-37 expression versus WT littermates, fed the HFD for 18 weeks, confirmed that IL-37 reduces food intake, which led to a decrease in lean body mass, but did not reduce fat mass and plasma lipid levels or alterations in energy expenditure independent of lean body mass. Taken together, this suggests that IL-37 reduces lean body mass by reducing food intake.

The Dipeptidyl Peptidases 4, 8, and 9 in Mouse Monocytes and Macrophages: DPP8/9 Inhibition Attenuates M1 Macrophage Activation in Mice

Atherosclerosis remains the leading cause of death in Western countries. Dipeptidyl peptidase (DPP) 4 has emerged as a novel target for the prevention and treatment of atherosclerosis. Family members DPP8 and 9 are abundantly present in macrophage-rich regions of atherosclerotic plaques, and DPP9 inhibition attenuates activation of human M1 macrophages in vitro. Studying this family in a mouse model for atherosclerosis would greatly advance our knowledge regarding their potential as therapeutic targets. We found that DPP4 is downregulated during mouse monocyte-to-macrophage differentiation. DPP8 and 9 expression seems relatively low in mouse monocytes and macrophages. Viability of primary mouse macrophages is unaffected by DPP4 or DPP8/9 inhibition. Importantly, DPP8/9 inhibition attenuates macrophage activation as IL-6 secretion is significantly decreased. Mouse macrophages respond similarly to DPP inhibition, compared to human macrophages. This shows that the mouse could become a valid model species for the study of DPPs as therapeutic targets in atherosclerosis.

Thresholds for Arterial Wall Inflammation Quantified by 18F-FDG PET Imaging: Implications for Vascular Interventional Studies

Objectives

This study assessed 5 frequently applied arterial ¹⁸fluorodeoxyglucose (¹⁸F-FDG) uptake metrics in healthy control subjects, those with risk factors and patients with cardiovascular disease (CVD), to derive uptake thresholds in each subject group. Additionally, we tested the reproducibility of these measures and produced recommended sample sizes for interventional drug studies.

Background

¹⁸F-FDG positron emission tomography (PET) can identify plaque inflammation as a surrogate endpoint for vascular interventional drug trials. However, an overview of ¹⁸F-FDG uptake metrics, threshold values, and reproducibility in healthy compared with diseased subjects is not available.

Methods

¹⁸F-FDG PET/CT of the carotid arteries and ascending aorta was performed in 83 subjects (61 ± 8 years) comprising 3 groups: 25 healthy controls, 23 patients at increased CVD risk, and 35 patients with known CVD. We quantified ¹⁸F-FDG uptake across the whole artery, the most-diseased segment, and within all active segments over several pre-defined cutoffs. We report these data with and without background corrections. Finally, we determined measurement reproducibility and recommended sample sizes for future drug studies based on these results.

Results

All ¹⁸F-FDG uptake metrics were significantly different between healthy and diseased subjects for both the carotids and aorta. Thresholds of physiological ¹⁸F-FDG uptake were derived from healthy controls using the 90th percentile of their target to background ratio (TBR) value (TBR_max); whole artery TBR_max is 1.84 for the carotids and 2.68 in the aorta. These were exceeded by >52% of risk factor patients and >67% of CVD patients. Reproducibility was excellent in all study groups (intraclass correlation coefficient >0.95). Using carotid TBR_max as a primary endpoint resulted in sample size estimates approximately 20% lower than aorta.

Conclusions

We report thresholds for physiological ¹⁸F-FDG uptake in the arterial wall in healthy subjects, which are exceeded by the majority of CVD patients. This remains true, independent of readout vessel, signal quantification method, or the use of background correction. We also confirm the high reproducibility of ¹⁸F-FDG PET measures of inflammation. Nevertheless, because of overlap between subject categories and the relatively small population studied, these data have limited generalizability until substantiated in larger, prospective event-driven studies. (Vascular Inflammation in Patients at Risk for Atherosclerotic Disease; NTR5006)

Regulation of macrophage polarization and plasticity by complex activation signals

Macrophages are versatile cells of the immune system that play an important role in both advancing and resolving inflammation. Macrophage activation has been described as a continuum, and different stimuli lead to M1, M2, or mixed phenotypes. In addition, macrophages expressing markers associated with both M1 and M2 function are observed in vivo. Using flow cytometry, we examine how macrophage populations respond to combined M1 and M2 activation signals, presented either simultaneously or sequentially. We demonstrate that macrophages exposed to a combination of LPS, IFN-γ, IL-4, and IL-13 acquire a mixed activation state, with individual cells expressing both M1 marker CD86 and M2 marker CD206 instead of polarizing to discrete phenotypes. Over time, co-stimulated macrophages lose expression of CD86 and display increased expression of CD206. In addition, we find that exposure to LPS/IFN-γ potentiates the subsequent response to IL-4/IL-13, whereas pre-polarization with IL-4/IL-13 inhibits the response to LPS/IFN-γ. Mathematical modeling of candidate regulatory networks indicates that a complex inter-dependence of M1- and M2-associated pathways underlies macrophage activation. Specifically, a mutual inhibition motif was not by itself sufficient to reproduce the temporal marker expression data; incoherent feed-forward of M1 activation as well as both inhibition and activation of M2 by M1 were required. Together these results corroborate a continuum model of macrophage activation and demonstrate that phenotypic markers evolve with time and with exposure to complex signals.

Main applications of hybrid PET-MRI contrast agents: a review

In medical imaging, the continuous quest to improve diagnostic performance and optimize treatment strategies has led to the use of combined imaging modalities. Positron emission tomography (PET) and computed tomography (CT) is a hybrid imaging existing already for many years. The high spatial and contrast resolution of magnetic resonance imaging (MRI) and the high sensitivity and molecular information from PET imaging are leading to the development of this new hybrid imaging along with hybrid contrast agents. To create a hybrid contrast agent for PET-MRI device, a PET radiotracer needs to be combined with an MRI contrast agent. The most common approach is to add a radioactive isotope to the surface of a small superparamagnetic iron oxide (SPIO) particle. The resulting agents offer a wide range of applications, such as pH variation monitoring, non-invasive angiography and early imaging diagnosis of atherosclerosis. Oncology is the most promising field with the detection of sentinel lymph nodes and the targeting of tumor neoangiogenesis. Oncology and cardiovascular imaging are thus major areas of development for hybrid PET-MRI imaging systems and hybrid contrast agents. The aim is to combine high spatial resolution, high sensitivity, morphological and functional information. Future prospects include the use of specific antibodies and hybrid multimodal PET-MRI-ultrasound-fluorescence imaging with the potential to provide overall pre-, intra- and postoperative patient care.

Novel directions in inflammation as a therapeutic target in atherosclerosis

PURPOSE OF REVIEW

Atherosclerosis is a chronic disease of the arterial wall largely driven by inflammation; hence, therapeutics targeting inflammatory pathways are considered an attractive strategy in atherosclerotic cardiovascular disease (ASCVD). The purpose of this review is to describe the randomized, placebo-controlled clinical trials currently investigating the impact of anti-inflammatory strategies in ASCVD patients, to discuss novel insights and targets into the role of innate immunity in atherosclerosis and to address the promise of local drug delivery as opposed to systemic therapies in atherosclerotic disease.

RECENT FINDINGS

The first clinical trials using systemic anti-inflammatory drugs in ASCVD patients might be able to strengthen the case for immunomodulation once showing an improved ASCVD outcome. Several specific targets in innate immunity bear therapeutic potential, of which some have already entered the clinical arena. To prevent immunosuppression by systemic effects, drug delivery systems are increasingly being applied to locally attenuate plaque inflammation.

SUMMARY

Anti-inflammatory therapies seem promising for future treatment of ASCVD. In view of the risk of immunosuppression in case of long term and systemic use of anti-inflammatory drugs, there is a clinical need for highly selective and targeted therapies in patients with atherosclerosis.

Exacerbation of tumor necrosis factor-induced vascular leak syndrome by aging

Aging is associated with upregulation of tumor necrosis factor (TNF) and increased vascular inflammation. TNF is a major proinflammatory cytokine that contributes to both vascular inflammation and vascular leak syndrome (VLS). The purpose of this study was to investigate whether the aging affects TNF-induced VLS. Vascular leak, histology, and cytokine assays were performed in young and aged groups of wild-type and TNF overexpressing transgenic (Tg) mice. An aged group of TNF Tg mice showed substantially amplified VLS compared with young Tg mice. Age-related amplification of TNF-induced VLS appears to be related to local vascular fibrosis and the systemic upregulation of TNF and MCP-1 levels in older TNF Tg mice. Our finding suggests that chronic high-grade TNF exposure could mediate the severe vascular pathogenicity of VLS.

The nutraceutical potential of omega-3 alpha-linolenic acid in reducing the consequences of stroke

Stroke is a worldwide major cause of mortality and morbidity. Preclinical studies have identified over 1000 molecules with brain-protective properties. More than 200 clinical trials have evaluated neuroprotective candidates for ischemic stroke yet, to date almost all failed, leading to a re-analysis of treatment strategies against stroke. An emerging view is to seek combinatory therapy, or discovering molecules able to stimulate multiple protective and regenerative mechanisms. A pertinent experimental approach to identify such candidates is the study of brain preconditioning, which refers to how the brain protects itself against ischemia and others stress-inducing stimuli. The recent discovery that nutrients like alpha-linolenic acid (ALA is an essential omega-3 polyunsaturated fatty acid required as part of our daily diet), may be an efficient brain preconditionner against stroke fosters the novel concept of brain preconditioning by nutraceuticals. This review stresses the underestimated role of nutrition in preventing and combating stroke. Although there is a consensus that increased consumption of salt, fatty foods and alcoholic beverages may promote pathologies like hypertension, obesity and alcoholism - all of which are well known risk factors of stroke - few risk factors are attributed to a deficiency in an essential nutrient in the diet. The ALA deficiency observed in the Western modern diets may itself constitute a risk factor. This review outlines how ALA supplementation by modification of the daily diet prevented mortality and cerebral damage in a rodent model of ischemic stroke. It also describes the pleiotropic ability of ALA to trigger responses that are multicellular, mechanistically diverse, resulting in neuronal protection, stimulation of neuroplasticity, and brain artery vasodilation. Overall, this review proposes a promising therapeutic opportunity by integrating a nutritional-based approach focusing on enriching the daily diet in ALA to prevent the devastating damage caused by stroke.

Prednisolone-containing liposomes accumulate in human atherosclerotic macrophages upon intravenous administration

Drug delivery to atherosclerotic plaques via liposomal nanoparticles may improve therapeutic agents' risk-benefit ratios. Our paper details the first clinical studies of a liposomal nanoparticle encapsulating prednisolone (LN-PLP) in atherosclerosis. First, PLP's liposomal encapsulation improved its pharmacokinetic profile in humans (n=13) as attested by an increased plasma half-life of 63h (LN-PLP 1.5mg/kg). Second, intravenously infused LN-PLP appeared in 75% of the macrophages isolated from iliofemoral plaques of patients (n=14) referred for vascular surgery in a randomized, placebo-controlled trial. LN-PLP treatment did however not reduce arterial wall permeability or inflammation in patients with atherosclerotic disease (n=30), as assessed by multimodal imaging in a subsequent randomized, placebo-controlled study. In conclusion, we successfully delivered a long-circulating nanoparticle to atherosclerotic plaque macrophages in patients, whereas prednisolone accumulation in atherosclerotic lesions had no anti-inflammatory effect. Nonetheless, the present study provides guidance for development and imaging-assisted evaluation of future nanomedicine in atherosclerosis.

FROM THE CLINICAL EDITOR

In this study, the authors undertook the first clinical trial using long-circulating liposomal nanoparticle encapsulating prednisolone in patients with atherosclerosis, based on previous animal studies. Despite little evidence of anti-inflammatory effect, the results have provided a starting point for future development of nanomedicine in cardiovascular diseases.

Alpha-linolenic acid: an omega-3 fatty acid with neuroprotective properties-ready for use in the stroke clinic?

Alpha-linolenic acid (ALA) is plant-based essential omega-3 polyunsaturated fatty acids that must be obtained through the diet. This could explain in part why the severe deficiency in omega-3 intake pointed by numerous epidemiologic studies may increase the brain's vulnerability representing an important risk factor in the development and/or deterioration of certain cardio- and neuropathologies. The roles of ALA in neurological disorders remain unclear, especially in stroke that is a leading cause of death. We and others have identified ALA as a potential nutraceutical to protect the brain from stroke, characterized by its pleiotropic effects in neuroprotection, vasodilation of brain arteries, and neuroplasticity. This review highlights how chronic administration of ALA protects against rodent models of hypoxic-ischemic injury and exerts an anti-depressant-like activity, effects that likely involve multiple mechanisms in brain, and may be applied in stroke prevention. One major effect may be through an increase in mature brain-derived neurotrophic factor (BDNF), a widely expressed protein in brain that plays critical roles in neuronal maintenance, and learning and memory. Understanding the precise roles of ALA in neurological disorders will provide the underpinnings for the development of new therapies for patients and families who could be devastated by these disorders.

Inflammation and atherosclerosis: a review of the role of interleukin-6 in the development of atherosclerosis and the potential for targeted drug therapy

It has recently been appreciated that atherosclerosis is predominantly an inflammatory process. Atherosclerosis begins with a fatty streak, which is made up almost entirely of monocyte-derived macrophages. The development of an atheroma continues as T-cells, mast cells, and other inflammatory cells are recruited to the intima. This collection of inflammatory cells promotes smooth muscle cell replication and extracellular matrix elaboration, thereby increasing the lesion size. Various studies have highlighted that interleukin-6 (IL-6) is an upstream inflammatory cytokine that plays a central role in propagating the downstream inflammatory response responsible for atherosclerosis. IL-6 release is stimulated by acute infections, chronic inflammatory conditions, obesity, and physiologic stress. The high level of IL-6 found in such conditions has a myriad of functions, including hepatic synthesis of acute-phase reactants, activation of endothelial cells, increased coagulation, activation of the hypothalamic-pituitary-adrenal axis, and promotion of lymphocyte proliferation and differentiation. Considering the importance of IL-6 in the development of coronary artery disease, targeting its actions could prove to be beneficial. Individuals with a variant in the IL-6 receptor that impairs classic IL-6 signaling were found to have a decreased risk for coronary heart disease. Tocilizumab is a monoclonal antibody that targets the IL-6 receptor and has been show to alleviate symptoms in patients with rheumatoid arthritis, a disease largely driven by the proinflammatory actions of IL-6. Therefore, further studies are needed to determine the role of tocilizumab and other IL-6 receptor blockers in decreasing the inflammatory response key in the development of atherosclerosis.

Pathophysiological basis for compromised health beyond generations: role of maternal high-fat diet and low-grade chronic inflammation

Early exposure to a fat-enriched diet programs the developmental profile and thus is associated with disease susceptibility in subsequent generations. Chronic low-grade inflammation, resulting from maternal high-fat diet, is activated in the fetal environment and in many organs of offspring, including placenta, adipose, liver, vascular system and brain. The prevalence of an inflammatory response is highly associated with obesity incidence, cardiovascular diseases, nonalcoholic fatty liver disease and brain damage. Substantial studies using high-fat model have consistently demonstrated the incidence of such inflammatory reactions; however, the potential contribution of active inflammation toward the physiological outcomes and developmental diseases is neither discussed in depth nor systemically integrated. Therefore, we aim to summarize the current findings in regards to how a maternal high-fat diet influences the inflammatory status, and probable pathogenic effects on the offspring. More importantly, since limited research has been conducted to reveal the epigenetic regulation of these inflammatory markers by maternal high-fat diet, we sincerely hope that our review will not only outline the pathophysiological relevance of inflammation but also identify a future direction for mechanistic investigation and clinical application.

Association of interleukin-6 with the progression of carotid atherosclerosis: a 9-year follow-up study

BACKGROUND AND PURPOSE

Limited information is available on the long-term effects of interleukin-6 (IL-6) on systemic atherosclerosis. The purpose of the present study was to clarify the relationship between chronic elevation of IL-6 and the long-term progression of carotid atherosclerosis.

METHODS

We prospectively evaluated 210 patients with ≥1 vascular risk factors for 9.0±1.0 years. Carotid mean-maximal intima-media thickness (mmIMT), the serum high-sensitivity C-reactive protein (hs-CRP) level, and the serum IL-6 level were measured at baseline and every 3 years. The associations between the progression of mmIMT and the long-term average levels of hs-CRP and IL-6 were analyzed.

RESULTS

Carotid mmIMT increased throughout the study period (0.031±0.026 mm/y). Baseline mmIMT was significantly associated with baseline hs-CRP (P=0.002) and baseline IL-6 (P<0.001) levels. Progression of mmIMT was positively correlated with average hs-CRP (P=0.001) and average IL-6 (P<0.001) levels. When adjusted for age, sex, traditional risk factors, and baseline mmIMT, mmIMT progression remained significantly associated only with the average IL-6 level (standardized β=0.17; P=0.02), but not with the average hs-CRP level (standardized β=0.10; P=0.18).

CONCLUSIONS

Chronic elevation of serum IL-6 was associated with the progression of atherosclerosis in patients with vascular risk factors. IL-6 could be used as a quantitative marker and a potential therapeutic target for accelerated atherosclerosis.

Paraoxonases and chemokine (C-C motif) ligand-2 in noncommunicable diseases

Oxidative stress and inflammation underpin most diseases; their mechanisms are inextricably linked. Chronic inflammation is associated with oxidation, anti-inflammatory cascades are linked to decreased oxidation, increased oxidative stress triggers inflammation, and redox balance inhibits the inflammatory cellular response. Whether or not oxidative stress and inflammation represent the cause or consequence of cellular pathology, they contribute significantly to the pathogenesis of noncommunicable diseases (NCD). The incidence of obesity and other related metabolic disturbances are increasing, as are age-related diseases due to a progressively aging population. Relationships between oxidative stress, inflammatory signaling, and metabolism are, in the broad sense of energy transformation, being increasingly recognized as part of the problem in NCD. In this chapter, we summarize the pathologic consequences of an imbalance between circulating and cellular paraoxonases, the system for scavenging excessive reactive oxygen species and circulating chemokines. They act as inducers of migration and infiltration of immune cells in target tissues as well as in the pathogenesis of disease that perturbs normal metabolic function. This disruption involves pathways controlling lipid and glucose homeostasis as well as metabolically driven chronic inflammatory states that encompass several response pathways. Dysfunction in the endoplasmic reticulum and/or mitochondria represents an important feature of chronic disease linked to oxidation and inflammation seen as self-reinforcing in NCD. Therefore, correct management requires a thorough understanding of these relationships and precise interpretation of laboratory test results.

Atorvastatin improves plaque stability in ApoE-knockout mice by regulating chemokines and chemokine receptors

It is well documented that statins protect atherosclerotic patients from inflammatory changes and plaque instability in coronary arteries. However, the underlying mechanisms are not fully understood. Using a previously established mouse model for vulnerable atherosclerotic plaque, we investigated the effect of atorvastatin (10 mg/kg/day) on plaque morphology. Atorvastatin did not lower plasma total cholesterol levels or affect plaque progression at this dosage; however, vulnerable plaque numbers were significantly reduced in the atorvastatin-treated group compared to control. Detailed examinations revealed that atorvastatin significantly decreased macrophage infiltration and subendothelial lipid deposition, reduced intimal collagen content, and elevated collagenase activity and expression of matrix metalloproteinases (MMPs). Because vascular inflammation is largely driven by changes in monocyte/macrophage numbers in the vessel wall, we speculated that the anti-inflammatory effect of atorvastatin may partially result from decreased monocyte recruitment to the endothelium. Further experiments showed that atorvastatin downregulated expression of the chemokines monocyte chemoattractant protein (MCP)-1, chemokine (C-X3-C motif) ligand 1 (CX3CL1) and their receptors CCR2 and, CX3CR1, which are mainly responsible for monocyte recruitment. In addition, levels of the plasma inflammatory markers C-reactive protein (CRP) and tumor necrosis factor (TNF)-α were also significantly decrease in atorvastatin-treated mice. Collectively, our results demonstrate that atorvastatin can improve plaque stability in mice independent of plasma cholesterol levels. Given the profound inhibition of macrophage infiltration into atherosclerotic plaques, we propose that statins may partly exert protective effects by modulating levels of chemokines and their receptors. These findings elucidate yet another atheroprotective mechanism of statins.

Carotid intima media thickness and arterial stiffness in children with acute rheumatic fever

Acute rheumatic fever (ARF) and rheumatic heart disease (RHD) constitute important public health problems in developing countries. Inflammation is present both in the early and late stages of the diseases. Chronic inflammation is known to be associated with atherosclerosis. We hypothesize that subclinical atherosclerosis and arterial stiffness may increase due to the ongoing inflammation as well as the increased pulse pressure and left-ventricular systolic dysfunction in RHD. The purpose of the present study was to investigate carotid intima media thickness (CIMT) and carotid artery stiffness in patients with ARF. Forty patients in follow-up due to ARF in the age group of 7-16 years (disease duration 1-10 years) and 36 volunteered subjects with similar body mass index were included in the study. The subjects included in the present study were compared regarding M-mode echocardiographic parameters and CIMT as well as carotid arterial strain (CAS), carotid artery distensibility (CAD), beta stiffness index (βSI), and pressure-strain elasticity modulus (Ep) as carotid artery stiffness parameters. CIMT (0.52 ± 0.08 and 0.48 ± 0.07 mm, p = 0.01), βSI (5.29 ± 2.98 and 3.02 ± 1.30, p < 0.001), and Ep (426.53 ± 210.50 and 254.44 ± 104.69 p < 0.001) were increased, whereas CAS (0.11 ± 0.01 and 0.19 ± 0.09, p < 0.001) and CAD (10.27 ± 4.69 and 17.76 ± 14.41, p < 0.001) were decreased in patients with ARF compared with the control group. There was a positive correlation between pulse pressure and βSI (r = 0.25, p = 0.02) and Ep (r = 0.28, p = 0.01) in addition to a correlation between left atrial dilatation and CIMT (r = 0.55 p < 0.001) in patients with ARF. CIMT and carotid artery stiffness were increased in patients with ARF. Patients with ARF may have an increased risk of subclinical atherosclerosis and cardiovascular events.

Activation of mTOR modulates SREBP-2 to induce foam cell formation through increased retinoblastoma protein phosphorylation

AIMS

Our previous studies demonstrated that inflammation contributes to atherosclerosis through disruption of the low density lipoprotein receptor (LDLr) pathway. However, this effect is overridden by rapamycin, which is an inhibitor of mammalian target of rapamycin (mTOR). This study investigated the role of the mTOR pathway in atherosclerosis in vivo and in vitro.

METHODS AND RESULTS

To induce inflammation, we used subcutaneous injection of 10% casein in apolipoprotein E knockout (ApoE KO) mice and lipopolysaccharide stimulation in rat vascular smooth muscle cells (VSMCs). Results showed that inflammation increased lipid accumulation in aortas of ApoE KO mice and in VSMCs, which were correlated with increased expressions of LDLr, sterol regulatory element-binding protein (SREBP) cleavage-activating protein (SCAP), and SREBP-2 as well as with enhanced translocation of SCAP/SREBP-2 complex from the endoplasmic reticulum (ER) to the Golgi. Furthermore, inflammation increased both the percentage of cells in the S phase of cell cycle and protein expressions of the phosphorylated forms of retinoblastoma tumour suppressor protein (Rb), mTOR, eukaryotic initiation factor 4E-binding protein 1 (4EBP1), and P70 S6 kinase. After treatment with rapamycin or mTOR siRNA, the activity of the mTOR pathway was blocked. Interestingly, the expression levels of LDLr, SCAP, and SREBP-2 and the translocation of SCAP/SREBP-2 complex from the ER to the Golgi in treated VSMCs were decreased even in the presence of inflammatory stress.

CONCLUSION

Our findings demonstrate for the first time that inflammation disrupts LDLr feedback regulation through the activation of the mTOR pathway. Increased mTORC1 activity was found to up-regulate SREBP-2-mediated cholesterol uptake through Rb phosphorylation.

Fosinoprilat alleviates lipopolysaccharide (LPS)-induced inflammation by inhibiting TLR4/NF-κB signaling in monocytes

OBJECTIVE

To evaluate the effect of the fosinoprilat on lipopolysacharides (LPS) induced inflammation in monocytes in vitro.

METHODS

Human mononuclear THP1 cells were cultured in complete medium, treated with or without LPS and different concentrations (0,0.25,0.5,1,5,and 10μmol/L) of fosinoprilat. Toll-like receptor (TLR4) mRNA expression was detected by real-time RT-PCR and TLR4 protein level on the surface of monocyte was determined by flow cytometry. Nuclear factor-kappa B (NF-κB) protein level was detected by Western blotting. Cultured supernatant of the THP1 cells in different groups were analyzed by ELISA to detect the levels of interleukin (IL)-1β, IL-6 and tumor necrosis factor (TNF-α).

RESULTS

Both the mRNA and surface protein level of the TLR4 in the THP1 cells were enhanced by the LPS treatment and down-regulated by pretreatment of the fosinoprilat. Accordingly, LPS-induced NF-κB protein was decreased by the fosinoprilat treatment. The increasing secretion of IL-1β, IL-6 and TNF-α induced by LPS could also be attenuated by the fosinoprilat treatment.

CONCLUSION

The inhibitory effect of the fosinoprilat on the TRL4/NF-κB signaling pathway reveals a potential anti-inflammatory and anti-atherosclerosis target.

Atherosclerosis, dyslipidemia, and inflammation: the significant role of polyunsaturated Fatty acids

Phospholipids play an essential role in cell membrane structure and function. The length and number of double bonds of fatty acids in membrane phospholipids are main determinants of fluidity, transport systems, activity of membrane-bound enzymes, and susceptibility to lipid peroxidation. The fatty acid profile of serum lipids, especially the phospholipids, reflects the fatty acid composition of cell membranes. Moreover, long-chain n-3 polyunsatured fatty acids decrease very-low-density lipoprotein assembly and secretion reducing triacylglycerol production. N-6 and n-3 polyunsatured fatty acids are the precursors of signalling molecules, termed "eicosanoids," which play an important role in the regulation of inflammation. Eicosanoids derived from n-6 polyunsatured fatty acids have proinflammatory actions, while eicosanoids derived from n-3 polyunsatured fatty acids have anti-inflammatory ones. Previous studies showed that inflammation contributes to both the onset and progression of atherosclerosis: actually, atherosclerosis is predominantly a chronic low-grade inflammatory disease of the vessel wall. Several studies suggested the relationship between long-chain n-3 polyunsaturated fatty acids and inflammation, showing that fatty acids may decrease endothelial activation and affect eicosanoid metabolism.