Expression of Resistin, Chemerin, and Chemerin's Receptor in the Unstable Carotid Atherosclerotic Plaque

Circulating Sex-Specific Markers of Plaque Instability in Women and Men With Severe Carotid Atherosclerosis

BACKGROUND

Sex-specific differences in plaque composition and instability underscore the need to explore circulating markers for better prediction of high-risk plaques. This cross-sectional study aims to (1) investigate differences in lipid, immune, and adipokine circulating profiles between men and women with stable versus unstable plaques and (2) identify circulating markers that can better classify men and women according to plaque instability.

METHODS

Preoperative blood samples and plaque specimens were collected from consecutive men and women with carotid artery stenosis ≥50% and who underwent a carotid endarterectomy between 2009 and 2018. Adipokine, lipid, and immune profiling was conducted. Plaque stability was determined by gold-standard histological classifications. Statistical analyses, including χ2, ANOVA, Kruskal-Wallis, and logistic regression, assessed differences in plaque features and blood parameters between men and women with stable and unstable plaques.

RESULTS

Of 470 recruited patients (aged 70.8±9.2 years), the final study analyses included 317 men and 143 women (aged 71.0±9.0 years). Men exhibited more unstable plaques (P<0.001), characterized by increased plaque hemorrhage, larger lipid core, and inflammation (P<0.001), along with less favorable circulating profiles. Antagonistic interactions between sex and white blood cell (WBC) counts, basophil-to-WBC ratio, and platelet counts influenced plaque instability. In men, low WBC counts, high monocyte-to-WBC ratio, low basophil-to-WBC ratio, and high LDL-C (low-density lipoprotein cholesterol) levels were associated with greater plaque instability (odds ratio, 0.827 [95% CI, 0.713-0.926], 1.158 [95% CI, 1.027-1.305], 0.495 [95% CI, 0.281-0.871], and 1.564 [95% CI, 1.001-2.443], respectively) and more unstable features (ie, inflammation, foam cells, and neovascularization). In women, a high basophil-to-WBC ratio was associated with greater plaque instability (3.142 [95% CI, 1.220-8.093]), hemorrhage, and thrombosis, while a high molecular weight-to-total adiponectin ratio was associated with decreased instability (0.014 [95% CI, 0.000-0.646]) and inflammation.

CONCLUSIONS

Our findings demonstrated sex-specific differences, with women displaying more stable plaque phenotypes and favorable circulating profiles compared with men. This proof-of-concept study was also designed as the key first step in exploring novel sex-specific associations between circulating lipid, immune, and adipokine profiles and carotid plaque instability.

Association of plasma chemerin with all-cause and disease-specific mortality - results from a population-based study

BACKGROUND AND OBJECTIVES

Various cross-sectional studies have observed an association between high circulating concentrations of the adipokine chemerin and an unfavorable metabolic profile. However, the prognostic value of chemerin for the risk of associated diseases and mortality was examined only in a few studies mostly using small and highly selected patient populations. We aimed to analyze the association between plasma chemerin concentrations and all-cause as well as cause-specific mortality in the general population.

STUDY DESIGN AND METHODS

From the Study of Health in Pomerania (SHIP), participants of two independent cohorts (SHIP-START-1 [n = 3037], SHIP-TREND-0 [n = 4193]) were followed up for 15 and 9 years (median), respectively. The association between plasma chemerin and all-cause mortality was analyzed using multivariable Cox proportional hazard regression models. Additionally, cause-specific hazards for cardiovascular disease (CVD) and cancer mortality were modeled considering competing events.

RESULTS

A total number of 507 and 208 deaths occurred during follow-up in SHIP-START-1 and SHIP-TREND-0, respectively. Multivariable regression analyses revealed a significant association between high plasma chemerin concentrations and greater overall mortality that was independent of major confounders. Each 30 ng/mL increase in chemerin was associated with a 17% higher risk of all-cause mortality (95%-confidence interval: 1.10-1.26). Cause-specific analyses further showed that the chemerin concentration was significantly associated with cancer mortality but not with CVD mortality.

CONCLUSION

The present study detected a positive association between plasma chemerin concentrations and all-cause mortality in a large population-based study sample. Cause-specific analyses have shown that chemerin is likely to play a decisive role in cancer-related deaths. However, a direct association with cardiovascular mortality could not be established.

Adipokines in atherosclerosis: unraveling complex roles

Adipokines are biologically active factors secreted by adipose tissue that act on local and distant tissues through autocrine, paracrine, and endocrine mechanisms. However, adipokines are believed to be involved in an increased risk of atherosclerosis. Classical adipokines include leptin, adiponectin, and ceramide, while newly identified adipokines include visceral adipose tissue-derived serpin, omentin, and asprosin. New evidence suggests that adipokines can play an essential role in atherosclerosis progression and regression. Here, we summarize the complex roles of various adipokines in atherosclerosis lesions. Representative protective adipokines include adiponectin and neuregulin 4; deteriorating adipokines include leptin, resistin, thrombospondin-1, and C1q/tumor necrosis factor-related protein 5; and adipokines with dual protective and deteriorating effects include C1q/tumor necrosis factor-related protein 1 and C1q/tumor necrosis factor-related protein 3; and adipose tissue-derived bioactive materials include sphingosine-1-phosphate, ceramide, and adipose tissue-derived exosomes. However, the role of a newly discovered adipokine, asprosin, in atherosclerosis remains unclear. This article reviews progress in the research on the effects of adipokines in atherosclerosis and how they may be regulated to halt its progression.

The Role of Chemerin in Metabolic and Cardiovascular Disease: A Literature Review of Its Physiology and Pathology from a Nutritional Perspective

Chemerin is a novel adipokine that plays a major role in adipogenesis and lipid metabolism. It also induces inflammation and affects insulin signaling, steroidogenesis and thermogenesis. Consequently, it likely contributes to a variety of metabolic and cardiovascular diseases, including atherosclerosis, diabetes, hypertension and pre-eclampsia. This review describes its origin and receptors, as well as its role in various diseases, and subsequently summarizes how nutrition affects its levels. It concludes that vitamin A, fat, glucose and alcohol generally upregulate chemerin, while omega-3, salt and vitamin D suppress it. Dietary measures rather than drugs acting as chemerin receptor antagonists might become a novel tool to suppress chemerin effects, thereby potentially improving the aforementioned diseases. However, more detailed studies are required to fully understand chemerin regulation.

Relationship between circulating adipokines and cholesterol efflux in subjects with severe carotid atherosclerosis

AIMS

Cholesterol efflux capacity (CEC) as a measure of high-density lipoprotein functionality is independently and inversely associated with increased risk of cardiovascular events and mortality, and advanced plaque morphology. Adipokines, adipose tissue-derived factors, can influence systemic lipoprotein metabolism, and participate in the regulation of vascular function and inflammation. We aimed to investigate the association between CEC and circulating adipokine levels (anti-inflammatory adiponectin, and pro-inflammatory chemerin and resistin) in subjects with severe carotid atherosclerotic disease and evaluate its impact on post-surgical outcomes.

METHODS AND RESULTS

This is a cross-sectional study with a 5-year follow-up component. Consecutive patients with severe carotid atherosclerosis scheduled for a carotid endarterectomy were recruited from hospital-based centres in Montreal, Canada (n = 285). Fasting blood samples were collected pre-operatively and used to measure plasma total and high-molecular weight (HMW) adiponectin, chemerin, and resistin, and to perform cholesterol efflux assays in J774 macrophage-like cells. Five-year post-surgery outcomes were obtained through medical chart review. Subjects had a mean age of 70.1 ± 9.4, were 67.0 % male, had various comorbidities (hypercholesterolemia [85.3 %], hypertension [83.5 %], type 2 diabetes [34.5 %], coronary artery disease [38.6 %]), and previously experienced cerebrovascular symptomatology (77.9 %). CEC was independently and positively associated with total and HMW adiponectin levels (ß [95 % confidence interval]; 0.216 [0.134-0.298] and 0.107 [0.037-0.176], respectively) but not with chemerin or resistin. Total adiponectin had the greatest association accounting for 8.3 % of the variance in CEC. Interaction regression models demonstrated a significant interaction between adiponectin and chemerin in increasing CEC. Notably, with each unit increase in CEC there was a 93.9 % decrease in the odds of having an ischemic cerebrovascular event 5 years post-surgery (0.061 [0.007-0.561]).

CONCLUSIONS

Our findings demonstrated circulating adiponectin to have a strong association with increased CEC in subjects with severe carotid atherosclerosis and high CEC to be associated with more favourable post-surgical outcomes. These findings reflect the importance of adipose tissue health in influencing CEC levels and atherosclerotic cardiovascular disease risk.

Gender Differences and Cardiometabolic Risk: The Importance of the Risk Factors

Metabolic syndrome (Mets) is a clinical condition characterized by a cluster of major risk factors for cardiovascular disease (CVD) and type 2 diabetes: proatherogenic dyslipidemia, elevated blood pressure, dysglycemia, and abdominal obesity. Each risk factor has an independent effect, but, when aggregated, they become synergistic, doubling the risk of developing cardiovascular diseases and causing a 1.5-fold increase in all-cause mortality. We will highlight gender differences in the epidemiology, etiology, pathophysiology, and clinical expression of the aforementioned Mets components. Moreover, we will discuss gender differences in new biochemical markers of metabolic syndrome and cardiovascular risk.

Osteopontin as Candidate Biomarker of Coronary Disease despite Low Cardiovascular Risk: Insights from CAPIRE Study

Stratification according high cardiovascular (CV) risk categories, still represents a clinical challenge. In this analysis of the CAPIRE study (NCT02157662), we investigate whether inflammation could fit between CV risk factors (RFs) and the presence of coronary artery disease (CAD). In total, 544 patients were included and categorized according with the presence of CAD and CV risk factor burden (low/multiple). The primary endpoint was to verify any independent association of neutrophil-related biomarkers with CAD across CV risk categories. The highest values of osteopontin (OPN) were detected in the low RF group and associated with CAD (23.2 vs. 19.4 ng/mL; p = 0.001), although no correlation with plaque extent and/or composition were observed. Conversely, myeloperoxidase (MPO) and resistin did not differ by CAD presence. Again, OPN was identified as independent variable associated with CAD but only in the low RF group (adjOR 8.42 [95% CI 8.42–46.83]; p-value = 0.015). As an ancillary finding, a correlation linked OPN with the neutrophil degranulation biomarker MPO (r = 0.085; p = 0.048) and resistin (r = 0.177; p = 3.4 × 10−5). In the present study, OPN further strengthens its role as biomarker of CAD, potentially bridging subclinical CV risk with development of atherosclerosis.

Non-stenotic Carotid Plaques in Embolic Stroke of Unknown Source

Embolic stroke of unknown source (ESUS) represents one in five ischemic strokes. Ipsilateral non-stenotic carotid plaques are identified in 40% of all ESUS. In this narrative review, we summarize the evidence supporting the potential causal relationship between ESUS and non-stenotic carotid plaques; discuss the remaining challenges in establishing the causal link between non-stenotic plaques and ESUS and describe biomarkers of potential interest for future research. In support of the causal relationship between ESUS and non-stenotic carotid plaques, studies have shown that plaques with high-risk features are five times more prevalent in the ipsilateral vs. the contralateral carotid and there is a lower incidence of atrial fibrillation during follow-up in patients with ipsilateral non-stenotic carotid plaques. However, non-stenotic carotid plaques with or without high-risk features often coexist with other potential etiologies of stroke, notably atrial fibrillation (8.5%), intracranial atherosclerosis (8.4%), patent foramen ovale (5-9%), and atrial cardiopathy (2.4%). Such puzzling clinical associations make it challenging to confirm the causal link between non-stenotic plaques and ESUS. There are several ongoing studies exploring whether select protein and RNA biomarkers of plaque progression or vulnerability could facilitate the reclassification of some ESUS as large vessel strokes or help to optimize secondary prevention strategies.