The iterative lipid impact on inflammation in atherosclerosis

The role of systemic inflammation in remnant cholesterol associated cardiovascular risk: insights from the EPIC-Norfolk study

AIMS

Both plasma levels of remnant cholesterol and low-density lipoprotein cholesterol (LDL-C) levels are independent risk factors for atherosclerotic cardiovascular disease. However, only remnant cholesterol has consistently been associated with systemic inflammation. In this study, we aimed to assess the extent to which inflammation mediates the effect of remnant and LDL cholesterol on (non)fatal major adverse cardiovascular events (MACE), comprising of coronary artery disease and ischemic stroke.

METHODS AND RESULTS

This prospective study included 16,445 participants without prior atherosclerotic cardiovascular disease from the EPIC-Norfolk study, with a mean age of 58.8±9.1 years, of which 9,357 (56.9%) were women. Every 1 mmol/L higher remnant cholesterol was associated with 29.5% higher high-sensitivity C-reactive protein (hsCRP) levels (95% Confidence Interval (CI): 22.1, 37.4, p<0.001), whereas LDL-C was not significantly associated with hsCRP levels in the fully adjusted model. Additionally, each 1 mmol/L higher remnant cholesterol was associated with a hazard ratio (HR) of 1.31 (95% CI: 1.14, 1.50, p<0.001) for MACE, compared to a HR of 1.21 (95% CI: 1.13, 1.31, p<0.001) for LDL-C. Mediation analysis showed that hsCRP mediated 5.9% (95% CI: 1.2, 10.6%, p<0.001) of the effect of remnant cholesterol on MACE, whereas hsCRP did not mediate the effect of LDL-C.

CONCLUSIONS

Plasma remnant cholesterol levels are independently associated with systemic inflammation and cardiovascular events. Inflammation, as measured with hsCRP, contributed minorly to the association between remnant cholesterol and MACE. This underscores the need to address both remnant cholesterol and systemic inflammation separately in the clinical management of cardiovascular disease.

Plasma metabolomic signature of a proinflammatory diet in relation to breast cancer risk: a prospective cohort study

BACKGROUND

A proinflammatory diet has been linked to an increased risk of breast cancer. However, the underlying metabolic roles remain to be elucidated.

OBJECTIVES

This study aimed to investigate the metabolic mechanism between proinflammatory diet and breast cancer risk.

METHODS

This prospective study included 273,324 females from the UK Biobank. The dietary inflammatory potential was assessed via an energy-adjusted dietary inflammatory index (E-DII) based on a 24-h recall questionnaire. The plasma metabolome was profiled via high-throughput nuclear magnetic resonance spectroscopy. A metabolic signature was constructed by summing selected metabolite concentrations weighted by the coefficients via absolute shrinkage and selection operator analysis. Multivariate Cox regression was applied to assess the associations of the E-DII and metabolic signature with breast cancer risk.

RESULTS

We constructed a metabolic signature comprising 26 metabolites associated with a proinflammatory diet. These metabolites primarily included lipoproteins, amino acids, fatty acids, and ketone bodies. Both the E-DII and metabolic signature were positively associated with breast cancer risk [hazard ratio (HR) comparing the highest quintile with the lowest quintile: 1.17; 95% CI: 1.04, 1.32; and 1.21; 95% CI: 1.01, 1.46, respectively]. Furthermore, we found that saturated fatty acids to total fatty acids percentage and acetone concentration were positively associated (HR: 1.20; 95% CI: 1.04, 1.37; HR: 1.15; 95% CI: 1.01, 1.32, respectively), whereas the degree of unsaturation was inversely associated with breast cancer risk (HR: 0.86; 95% CI: 0.75, 0.99).

CONCLUSIONS

We identified a metabolic signature that reflects a proinflammatory diet and is associated with increased risk of breast cancer.

Predictive value of remnant cholesterol inflammatory index for stroke risk: Evidence from the China health and Retirement Longitudinal study

INTRODUCTION

Remnant cholesterol (RC) and high-sensitivity C-reactive protein (hs-CRP) are established stroke risk factors, but their joint impact remains unclear.

OBJECTIVES

This study aimed to evaluate the predictive value of the remnant cholesterol inflammatory index (RCII), a novel index integrating RC and hs-CRP, in assessing stroke risk.

METHODS

We analyzed 9,898 participants aged 45 years or older, with no history of stroke at baseline, from the China Health and Retirement Longitudinal Study (CHARLS). RCII was calculated using the formula: RCII = RC (mg/dL) × hs-CRP(mg/L)/10. A subset of 5,704 participants was studied to investigate the relationship between cumulative RCII exposure and stroke incidence. The associations of both baseline and cumulative RCII with stroke risk were assessed using Cox proportional hazards regression model.

RESULTS

During a median 7-year follow-up, 560 participants (5.7 %) experienced an incident stroke. Stroke incidence escalated with increasing RCII quartiles, from 3.5 % (Q1) to 7.6 % (Q4). In multivariable-adjusted analyses, each standard deviation increase in RCII was significantly associated with a 10.6 % increased risk of stroke (HR = 1.106, 95 % CI: 1.048-1.167). ROC analysis revealed that RCII had the highest AUC at 0.581, higher than RC (0.566) and hs-CRP (0.560), though the difference with RC was not statistically significant (P = 0.166). Mediation analysis indicated a reciprocal mediation between RC and hs-CRP on stroke risk. In a 3-year subset analysis, 288 participants suffered a stroke. Participants with cumulative RCII levels exceeding 36.14 had a significantly increased risk of incident stroke (HR = 1.462, 95 % CI: 1.102-1.939). Subgroup analyses showed a significant positive association between elevated RCII levels and stroke risk in males, but not in females.

CONCLUSIONS

Elevated levels of RCII, both at baseline and cumulative, are significantly associated with an increased risk of stroke. Early intervention in patients with high RCII may further help reduce stroke risk.

Ancestry specific distribution of LPA Kringle IV-Type-2 genetic variants highlight associations to apo(a) copy number, glucose, and hypertension

Background

High Lp(a) levels contribute to atherosclerotic cardiovascular disease and are tightly regulated by the LPA gene . Lp(a) levels have an inverse correlation with LPA Kringle IV Type-2 (KIV-2) copy number (CN). Black (B) and Hispanic (H) individuals exhibit higher levels of Lp(a), and rates of CVD compared to non-Hispanic Whites (NHW). Therefore, we investigated genetic variations in the LPA KIV-2 region across three ancestries and their associations with metabolic risk factors.

Methods

Using published pipelines, we analyzed a multi-ethnic whole exome dataset comprising 3,817 participants from the Washington Heights and Inwood Columbia Aging Project (WHICAP): 886 [NHW (23%), 1,811 Caribbean (C) H (47%), and 1,120 B individuals (29%). Rare and common variants (alternative allele carrier frequency, CF < 0.01 or > 0.99 and 0.01 < CF < 0.99, respectively) were identified and KIV-2 CN estimated. The associations of variants and CN with history of heart disease, hypertension (HTN), stroke, lipid levels and clinical diagnosis of Alzheimer's disease (AD) was assessed. A small pilot provided in-silico validation of study findings.

Results

We report 1421 variants in the LPA KIV-2 repeat region, comprising 267 exonic and 1154 intronic variants. 61.4% of the exonic variants have not been previously described. Three novel exonic variants significantly increase the risk of HTN across all ethnic groups: 4785-C/A (frequency = 78%, odds ratio [OR] = 1.45, p = 0.032), 727-T/C (frequency = 96%, OR = 2.11, p = 0.032), and 723-A/G (frequency = 96%, OR = 1.97, p = 0.038). Additionally, six intronic variants showed associations with HTN: 166-G/A, 387-G/C, 402-G/A, 4527-A/T, 4541-G/A, and 4653-A/T. One intronic variant, 412-C/T, was associated with decreased blood glucose levels (frequency = 72%, β = -14.52, p = 0.02).Three of the associations were not affected after adjusting for LPA KIV-2 CN: 412-C/T (β = -14.2, p = 0.03), 166-G/A (OR = 1.41, p = 0.05), and 387-G/C (OR = 1.40, p = 0.05). KIV CN itself was significantly associated with 314 variants and was negatively correlated with plasma total cholesterol levels.

Conclusions

In three ancestry groups, we identify novel rare and common LPA KIV-2 region variants. We report new associations of variants with HTN and Glucose levels. These results underscore the genetic complexity of the LPA KIV-2 region in influencing cardiovascular and metabolic health, suggesting potential genetic regulation of pathways that can be studied for research and therapeutic interventions.

Peripheral blood mononuclear cell low molecular mass protein 7 in acute ischemic stroke: vertical change from admission to discharge and correlation with disability, stroke recurrence, and death

Objective

Low molecular mass protein 7 (LMP7) aggravates abnormal T cell differentiation and atherosclerosis, but its clinical role in acute ischemic stroke (AIS) is still unclear. This study aimed to investigate the correlation of peripheral blood mononuclear cell (PBMC) LMP7 with T cell subsets, disease severity, and prognosis in AIS patients.

Methods

A total of 162 AIS patients were enrolled for detecting PBMC LMP7 and T helper (Th) 1, Th2, and Th17 cells via reverse transcriptase-polymerase chain reaction and flow cytometry, respectively. In addition, PBMC LMP7 at discharge was also quantified.

Results

Increased LMP7 at admission was associated with decreased Th2 cells (P=0.014), elevated Th17 cells (P<0.001), C-reactive protein (P=0.005), National Institutes of Health Stroke Scale (NIHSS) score (P=0.007), and disease severity (defined by NIHSS score) (P=0.010). LMP7 at admission reflected a high risk of stroke recurrence (area under curve (AUC): 0.748, 95% confidence interval (CI): 0.564-0.932), but not mRS score at month 3 (M3) >2 (AUC: 0.585, 95%CI: 0.479-0.691), or death (AUC: 0.723, 95%CI: 0.338-1.000). LMP7 at discharge was reduced compared to that at admission (P<0.001). LMP7 at discharge was positively correlated with the risk of stroke recurrence (AUC: 0.849, 95%CI: 0.735-0.963) and death (AUC: 0.919, 95%CI: 0.836-1.000), but had a weak capacity to reflect mRS score at M3 >2 (AUC: 0.671, 95%CI: 0.578-0.765).

Conclusion

PBMC LMP7 positively correlates with Th17 cells, inflammation, and disease severity in AIS patients, meanwhile, its level at discharge shows a good ability to reflect the risks of stroke recurrence and death.

Exploring the mechanism of Erchen decoction in the treatment of atherosclerosis based on network pharmacology and molecular docking

BACKGROUND

Atherosclerosis (AS) is the cause of most cardiovascular diseases and imposes a huge economic burden on society. Erchen decoction (ECD) is an effective formula for treating AS, but its therapeutic mechanism remains unclear. This study will explore the mechanism of ECD mechanism for treating AS using network pharmacology and molecular docking.

METHODS

We searched ECD chemical composition information and related targets via Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform and SwissTargetPrediction databases, and gene names correction was performed using the UniProt database. AS-related targets were retrieved from OMIM, GeneCards, and DrugBank databases, and Venny 2.1 were used for intersection analysis. Protein-protein interaction network was constructed by the STRING database, and an interactive network of the drug-component-target-disease was drawn using the Cytoscape 3.9.0 software. Gene ontology and Kyoto Gene and Genome Encyclopedia enrichment analysis were performed by the DAVID database, and molecular docking validation of vital active ingredients and action targets of ECD was performed using AutoDock Vina software.

RESULTS

The 127 active components of ECD act on AS by regulating 231 targets and 151 pathways. The 6 core components are quercetin, polyporenic acid C, 18α-hydroxyglycyrrhetic acid, glyuranolide, 3beta-hydroxychloroxy-24-methylene-8-lanostene-21-oic acid, and obacunone. They may regulate AS by regulating core target genes, such as JUN, SRC, AKT1, PTGS2, ESR1, AR, MAPK1, MAPK3, and RELA, and acting on multiple vital pathways, such as AGE-RAGE signaling pathway in diabetic complications, Lipid and AS, and Fluid shear stress and AS. Molecular docking showed that the selected target protein had good binding activity to the active ingredient.

CONCLUSIONS

ECD has the characteristics of multi-components, multi-targets and multi-pathways in the treatment of AS. The results provide a theoretical basis for the clinical application of ECD and its mechanism.

Apoe-knockout induces strong vascular oxidative stress and significant changes in the gene expression profile related to the pathways implicated in redox, inflammation, and endothelial function

Apolipoprotein E (APOE) was recognized as a key regulator of lipid metabolism, which prompted the Apoe-knockout (Apoe^-/-) mouse to be the most widely used atherosclerotic model. However, with more and more important physiological roles of APOE being revealed, it is necessary to reacquaint its comprehensive function in the aorta. In this study, we aimed to reveal how Apoe-knockout impacts the gene pathways and phenotypes in the aorta of mice. We performed transcriptome sequencing to acquire the gene expression profile (GEP) for C57BL/6J and Apoe^-/- mouse aorta, and used enrichment analysis to reveal the signal pathways enriched for differentially expressed genes (DEGs). In addition, we used immunofluorescence and ELISA to detect the phenotypic differences of vascular tissues and plasma in the two-group mice. Apoe-knockout resulted in significant changes in the expression of 538 genes, among which about 75% were up-regulated and 134 genes were altered more than twice. In addition to the lipid metabolism pathways, DEGs were also mainly enriched in the pathways implicated in endothelial cell proliferation, migration of epithelial cells, immune regulatory, and redox. GSEA shows that the up-regulated genes are mainly enriched in 'immune regulation pathways' and 'signal regulation' pathways, while the down-regulated genes are enriched in lipid metabolism pathways, 'regulation_of_nitric_oxide_synthase_activity' and the pathways involved in redox homeostasis, including 'monooxygenase regulation', 'peroxisomes' and 'oxygen binding'. A significant increase of reactive oxygen species and a remarkable reduction of GSH/GSSG ratio were respectively observed in the vascular tissues and plasma of Apoe^-/- mice. In addition, endothelin-1 significantly increased in the vascular tissue and the plasma of Apoe^-/- mice. Taken together, our results suggest that besides functioning in lipid metabolism, APOE may be an important signal regulator that mediates the expression of the genes related to the pathways involved in redox, inflammation, and endothelial function. Apoe-knockout-induced strong vascular oxidative stress is also the key factor contributing to atherosclerosis.

The Concentration of PCSK9-Lp(a) Complexes and the Level of Blood Monocytes in Males with Coronary Atherosclerosis

In this study we analyzed the concentration of lipoprotein(a) (Lp(a)), PCSK9-Lp(a) complexes and the circulating monocyte subsets in coronary atherosclerosis. For this study, 257 patients with coronary atherosclerosis and 68 patients without stenotic atherosclerosis in the coronary, carotid and lower extremity arteries (control group) were enrolled. The monocyte subpopulations (classical CD14++CD16-, intermediate CD14++CD16+ and non-classical CD14+CD16++) were analyzed by direct immunofluorescence and flow cytometry. The Lp(a) and PCSK9-Lp(a) complexes in the serum were detected by ELISA. The concentration of Lp(a) was higher in the coronary atherosclerosis group compared with the controls (23.0 (9.1; 73.3) mg/dL versus 10.7 (4.7; 25.0) mg/dL, p < 0.05). No correlations between the level of Lp(a) and the concentration of the PCSK9-Lp(a) complexes, nor between the level of Lp(a) or PCSK9 and the total number of monocytes, were observed in either group. A slight positive correlation between the concentration of PCSK9-Lp(a) complexes and the absolute level of monocytes was obtained (r = 0.20, p = 0.002) in the patients with atherosclerosis due to the intermediate monocyte subsets (r = 0.33, p = 0.04). According to regression analysis, both the PCSK9-Lp(a) complexes concentration and BMI were related to the absolute number of blood monocytes in patients with atherosclerosis. Further studies are required to determine the pathogenetic contribution of PCSK9-Lp(a) complexes to the development of atherosclerosis.

Supporting evidence for lipoprotein(a) measurements in clinical practice

High levels of lipoprotein(a) [Lp(a)] are causal for development of atherosclerotic cardiovascular disease and highly regulated by genetics. Levels are higher in Blacks compared to Whites, and in women compared to men. Lp(a)'s main protein components are apolipoprotein (apo) (a) and apoB100, the latter being the main component of Low-Density Lipoprotein (LDL) particles. Studies have identified Lp(a) to be associated with inflammatory, coagulation and wound healing pathways. Lack of validated and accepted assays to measure Lp(a), risk cutoff values, guidelines for diagnosis, and targeted therapies have added challenges to the field. Scientific efforts are ongoing to address these, including studies evaluating the cardiovascular benefits of decreasing Lp(a) levels with targeted apo(a) lowering treatments. This review will provide a synopsis of evidence-based effects of high Lp(a) on disease presentation, highlight available guidelines and discuss promising therapies in development. We will conclude with current clinical information and future research needs in the field.

Vascular stiffening and endothelial dysfunction in atherosclerosis

PURPOSE OF REVIEW

Aging is an important risk factor for cardiovascular disease and is associated with increased vessel wall stiffness. Pathophysiological stiffening, notably in arteries, disturbs the integrity of the vascular endothelium and promotes permeability and transmigration of immune cells, thereby driving the development of atherosclerosis and related vascular diseases. Effective therapeutic strategies for arterial stiffening are still lacking.

RECENT FINDINGS

Here, we overview the literature on age-related arterial stiffening, from patient-derived data to preclinical in-vivo and in-vitro findings. First, we overview the common techniques that are used to measure stiffness and discuss the observed stiffness values in atherosclerosis and aging. Next, the endothelial response to stiffening and possibilities to attenuate this response are discussed.

SUMMARY

Future research that will define the endothelial contribution to stiffness-related cardiovascular disease may provide new targets for intervention to restore endothelial function in atherosclerosis and complement the use of currently applied lipid-lowering, antihypertensive, and anti-inflammatory drugs.

Elevated lipoprotein (a) levels and risk of peripheral artery disease outcomes: A systematic review

BACKGROUND

Despite strong association of elevated lipoprotein (a) (Lp(a)) levels with incident coronary and cerebrovascular disease, data for incident peripheral artery disease (PAD) are less robust. The main objective of the present systematic review was to analyze the association between elevated Lp(a) levels and PAD outcomes.

METHODS

This systematic review was performed according to PRISMA guidelines. A literature search was performed to detect randomized clinical trials or observational studies with a cohort design that evaluated the association between Lp(a) levels and PAD outcomes.

RESULTS

Fifteen studies including 493,650 subjects were identified and considered eligible for this systematic review. This systematic review showed that the vast majority of the studies reported a significant association between elevated Lp(a) levels and the risk of PAD outcomes. The elevated Lp(a) levels were associated with a higher risk of incident claudication (RR: 1.20), PAD progression (HR: 1.41), restenosis (HR: 6.10), death and hospitalization related to PAD (HR: 1.37), limb amputation (HR: 22.75), and lower limb revascularization (HR: 1.29 and 2.90). In addition, the presence of elevated Lp(a) values were associated with a higher risk of combined PAD outcomes, with HRs in a range between 1.14 and 2.80, despite adjusting for traditional risk factors. Heterogeneity of results can be explained by different patient populations studied and varying Lp(a) cut-off points of Lp(a) analyzed.

CONCLUSION

This systematic review suggests that evidence is available to support an independent positive association between Lp(a) levels and the risk of future PAD outcomes. PROSPERO Registration No.: 289253.

Pathophysiology of Atherosclerosis

Atherosclerosis is the main risk factor for cardiovascular disease (CVD), which is the leading cause of mortality worldwide. Atherosclerosis is initiated by endothelium activation and, followed by a cascade of events (accumulation of lipids, fibrous elements, and calcification), triggers the vessel narrowing and activation of inflammatory pathways. The resultant atheroma plaque, along with these processes, results in cardiovascular complications. This review focuses on the different stages of atherosclerosis development, ranging from endothelial dysfunction to plaque rupture. In addition, the post-transcriptional regulation and modulation of atheroma plaque by microRNAs and lncRNAs, the role of microbiota, and the importance of sex as a crucial risk factor in atherosclerosis are covered here in order to provide a global view of the disease.

Lipoprotein(a), Immune Cells and Cardiovascular Outcomes in Patients with Premature Coronary Heart Disease

The detection of lipoprotein(a) [Lp(a)] in the artery wall at the stage of lipid-bands formation may indicate that it participates in the atherosclerosis local nonspecific inflammatory process. Innate immune cells are involved in atherogenesis, with monocytes playing a major role in the initiation of atherosclerosis, while neutrophils can contribute to plaque destabilization. This work studies the relationship between Lp(a), immune blood cells and major adverse cardiovascular events (MACE) in patients with the early manifestation of coronary heart disease (CHD). The study included 200 patients with chronic CHD, manifested up to the age of 55 in men and 60 in women. An increased Lp(a) concentration [hyperLp(a)] was shown to predict cardiovascular events in patients with premature CHD with long-term follow-up. According to the logistic regression analysis results, an increase in the monocyte count with OR = 4.58 (95% CI 1.04–20.06) or lymphocyte-to-monocyte ratio with OR = 0.82 (0.68–0.99), (p < 0.05 for both) was associated with MACE in patients with early CHD, regardless of gender, age, classical risk factors, atherogenic lipoproteins concentration and statin intake. The combination of an increased monocyte count and hyperLp(a) significantly increased the proportion of patients with early CHD with subsequent development of MACE (p = 0.02, ptrend = 0.003). The odds of cardiovascular events in patients with early CHD manifestation were highest in patients with an elevated lymphocyte-to-monocyte ratio and an elevated Lp(a) level. A higher neutrophil blood count and an elevated neutrophil-to-lymphocyte ratio determined the faster development of MACE in patients with a high Lp(a) concentration. The data obtained in this study suggest that the high atherothrombogenicity of Lp(a) is associated with the “inflammatory” component and the innate immune cells involvement in this process. Thus, the easily calculated immunological ratios of blood cells and Lp(a) concentrations can be considered simple predictors of future cardiovascular events.

High Sensitivity C-Reactive Protein Increases the Risk of Carotid Plaque Instability in Male Dyslipidemic Patients

BACKGROUND

The aim of this study was to evaluate how the high sensitivity C-reactive protein (hs-CRP) values influence the risk of carotid plaque instability in association with other cardiovascular risk factors.

METHODS

One hundred and fifty-six carotid plaques from both symptomatic and asymptomatic patients requiring surgical carotid endarterectomy were retrospectively collected. According to the modified American Heart Association, atherosclerosis plaques have been histologically distinguished into unstable and stable. The following anamnestic and hematochemical data were also considered: age, gender, hypertension, diabetes mellitus, smoking habit, therapy, low-density lipoprotein (LDL)-C, kidney failure and hs-CRP.

RESULTS

The results of our study clearly show that high levels of hs-CRP significantly increase the carotid plaque instability in dyslipidemic patients. Specifically, a 67% increase of the risk of carotid plaque instability was observed in patients with high LDL-C. Therefore, the highest risk was observed in male dyslipidemic patients 2333 (95% CI 0.73-7.48) and in aged female patients 2713 (95% CI 0.14-53.27).

DISCUSSION

These data strongly suggest a biological relationship between the hs-CRP values and the alteration of lipidic metabolism mostly in male patients affected by carotid atherosclerosis. The measurement of hs-CRP might be useful as a potential screening tool in the prevention of atheroscletotic disease.