Antioxidant and Cytoprotective Properties of Polyphenol-Rich Extracts from Antirhea borbonica and Doratoxylon apetalum against Atherogenic Lipids in Human Endothelial Cells

The endothelial integrity is the cornerstone of the atherogenic process. Low-density lipoprotein (LDL) oxidation occurring within atheromatous plaques lead to deleterious vascular effects including endothelial cell cytotoxicity. The aim of this study was to evaluate the vascular antioxidant and cytoprotective effects of polyphenol-rich extracts from two medicinal plants from the Reunion Island: Antirhea borbonica (A. borbonica), Doratoxylon apetalum (D. apetalum). The polyphenol-rich extracts were obtained after dissolving each dry plant powder in an aqueous acetonic solution. Quantification of polyphenol content was achieved by the Folin–Ciocalteu assay and total phenol content was expressed as g gallic acid equivalent/100 g plant powder (GAE). Human vascular endothelial cells were incubated with increasing concentrations of polyphenols (1–50 µM GAE) before stimulation with oxidized low-density lipoproteins (oxLDLs). LDL oxidation was assessed by quantification of hydroperoxides and thiobarbituric acid reactive substances (TBARS). Intracellular oxidative stress and antioxidant activity (catalase and superoxide dismutase) were measured after stimulation with oxLDLs. Cell viability and apoptosis were quantified using different assays (MTT, Annexin V staining, cytochrome C release, caspase 3 activation and TUNEL test). A. borbonica and D. apetalum displayed high levels of polyphenols and limited LDL oxidation as well as oxLDL-induced intracellular oxidative stress in endothelial cells. Polyphenol extracts of A. borbonica and D. apetalum exerted a protective effect against oxLDL-induced cell apoptosis in a dose-dependent manner (10, 25, and 50 µM GAE) similar to that observed for curcumin, used as positive control. All together, these results showed significant antioxidant and antiapoptotic properties for two plants of the Reunion Island pharmacopeia, A. borbonica and D. apetalum, suggesting their therapeutic potential to prevent cardiovascular diseases by limiting LDL oxidation and protecting the endothelium.

The association between plasma furin and cardiovascular events after acute myocardial infarction

Background Furin is the key enzyme involved in the cleavage of pro-BNP and plays a critical role in the cardiovascular system through its involvement in lipid metabolism, blood pressure regulation and the formation of atheromatous plaques. NT-proBNP and recently, corin, also a key enzyme in the cleavage of pro-BNP, have been accepted as predictors of prognosis after acute myocardial infarction (AMI). This cohort study was conducted to investigate the relationship between plasma furin and the prognostic outcomes of AMI patients. Methods In total, 1100 AMI patients were enrolled in the study and their plasma furin concentrations were measured. The primary endpoint was major adverse cardiac events (MACE), a composite of cardiovascular (CV) death, non-fatal myocardial infarction (MI) and non-fatal stroke. The associations between plasma furin concentration and AMI outcomes were explored using Kaplan–Meier curves and multivariate Cox regression analysis. Results The results showed a slight increase in mean cTNT in patients with higher furin concentrations (P = 0.016). Over a median follow-up of 31 months, multivariate Cox regression analysis indicated that plasma furin was not significantly associated with MACE (HR 1.01; 95% CI 0.93–1.06; P = 0.807) after adjustment for potential conventional risk factors. However, plasma furin was associated with non-fatal MI (HR 1.09; 95% CI 1.01–1.17; P = 0.022) in the fully adjusted model. Subgroup analyses indicated no relationship between plasma furin and MACE in different subgroups. Conclusions This study found no association between plasma furin and risk of MACE. Thus, plasma furin may not be a useful predictor of poor prognosis after AMI. However, higher levels of plasma furin may be associated with a higher risk of recurrent non-fatal MI.

Relationship between epicardial fat volume measured by multi-detector computed tomography and coronary artery disease

Background The association between epicardial fat thickness and coronary artery disease (CAD) has been evaluated previously using echocardiography. Recently, multidetector computed tomography (MDCT), as a valuable tool in cardiovascular CT imaging, can improve characterization of CAD and give a more accurate volumetric quantitation of EF. The purpose of our study was to evaluate the relationship between the epicardial fat volume and CAD using multi-detector row CT. Results Out of the studied 120 patients, 22 patients were negative for CAD, while 98 patients had positive CAD. There was significant difference between both groups as regard epicardial fat volume (p < 0.001), and good relation was found between the amount of epicardial fat volume and coronary calcium score, number of affected vessel, plaque burden and degree of stenosis (p = < 0.001). Conclusion EAT volume was larger in the presence of obstructive CAD and atheromatous plaques. These data suggest that EAT is associated with the development of coronary atherosclerosis and potentially the most dangerous types of plaques.

Recent insights into atherosclerotic plaque cell autophagy

Cardiovascular and cerebrovascular diseases, such as coronary heart disease and stroke, caused by atherosclerosis have become the “number one killer”, seriously endangering human health in developing and developed countries. Atherosclerosis mainly occurs in large and medium-sized arteries and involves intimal thickening, accumulation of foam cells, and formation of atheromatous plaques. Autophagy is a cellular catabolic process that has evolved to defend cells from the turnover of intracellular molecules. Autophagy is thought to play an important role in the development of plaques. This review focuses on studies on autophagy in cells involved in the formation of atherosclerotic plaques, such as monocytes, macrophages, endothelial cells, dendritic cells, and vascular smooth muscle cells, indicating that autophagy plays an important role in plaque development. We mainly discuss the roles of autophagy in these cells in maintaining the stability of atherosclerotic plaques, providing a reference for the next steps to unravel the mechanisms of atherogenesis.

Computed tomography angiography of the coronary arteries: major findings in the clinical routine of a general hospital

Almost two decades ago, it became possible to use coronary computed tomography for the noninvasive assessment of the coronary arteries. That is an extremely accurate method for detecting or excluding coronary artery disease, even the subclinical forms. This pictorial essay aims to show the main imaging findings in 47 coronary computed tomography scans acquired at a general hospital between January 2014 and June 2018. The most common findings were atheromatous plaques (in 87%) and stents (in 34%). There were also incidental findings, not directly related to coronary artery disease, such as pulmonary nodules and aortic stenosis.

Extracellular NLRP3 inflammasome particles are internalized by human coronary artery smooth muscle cells and induce pro-atherogenic effects

Inflammation driven by intracellular activation of the NLRP3 inflammasome is involved in the pathogenesis of a variety of diseases including vascular pathologies. Inflammasome specks are released into the extracellular compartment from disrupting pyroptotic cells. The potential uptake and function of extracellular NLRP3 inflammasomes in human coronary artery smooth muscle cells (HCASMC) are unknown. Fluorescently labeled NLRP3 inflammasome particles were isolated from a mutant NLRP3-YFP cell line and used to treat primary HCASMC for 4 and 24 h. Fluorescent and expressional analyses showed that extracellular NLRP3-YFP particles are internalized into HCASMC, where they remain active and stimulate intracellular caspase-1 (1.9-fold) and IL-1β (1.5-fold) activation without inducing pyroptotic cell death. Transcriptomic analysis revealed increased expression level of pro-inflammatory adhesion molecules (ICAM1, CADM1), NLRP3 and genes involved in cytoskleleton organization. The NLRP3-YFP particle-induced gene expression was not dependent on NLRP3 and caspase-1 activation. Instead, the effects were partly abrogated by blocking NFκB activation. Genes, upregulated by extracellular NLRP3 were validated in human carotid artery atheromatous plaques. Extracellular NLRP3-YFP inflammasome particles promoted the secretion of pro-atherogenic and inflammatory cytokines such as CCL2/MCP1, CXCL1 and IL-17E, and increased HCASMC migration (1.8-fold) and extracellular matrix production, such as fibronectin (5.8-fold) which was dependent on NFκB and NLRP3 activation. Extracellular NLRP3 inflammasome particles are internalized into human coronary artery smooth muscle cells where they induce pro-inflammatory and pro-atherogenic effects representing a novel mechanism of cell-cell communication and perpetuation of inflammation in atherosclerosis. Therefore, extracellular NLRP3 inflammasomes may be useful to improve the diagnosis of inflammatory diseases and the development of novel anti-inflammatory therapeutic strategies.

Effect of Dysferlin Deficiency on Atherosclerosis and Plasma Lipoprotein Composition Under Normal and Hyperlipidemic Conditions

Dysferlinopathies are a group of muscle disorders caused by mutations to dysferlin, a transmembrane protein involved in membrane patching events following physical damage to skeletal myofibers. We documented dysferlin expression in vascular tissues including non-muscle endothelial cells, suggesting that blood vessels may have an endogenous repair system that helps promote vascular homeostasis. To test this hypothesis, we generated dysferlin-null mice lacking apolipoprotein E (ApoE), a common model of atherosclerosis, dyslipidemia and endothelial injury when stressed with a high fat, and cholesterol-rich diet. Despite high dysferlin expression in mouse and human atheromatous plaques, loss of dysferlin did not affect atherosclerotic burden as measured in the aortic root, arch, thoracic, and abdominal aortic regions. Interestingly, we observed that dysferlin-null mice exhibit lower plasma high-density lipoprotein cholesterol (HDL-C) levels than their WT controls at all measured stages of the disease process. Western blotting revealed abundant dysferlin expression in protein extracts from mouse livers, the main regulator of plasma lipoprotein levels. Despite abnormal lipoprotein levels, Dysf/ApoE double knockout mice responded to cholesterol absorption blockade with lower total cholesterol and blunted atherosclerosis. Our study suggests that dysferlin does not protect against atherosclerosis or participate in cholesterol absorption blockade but regulates basal plasma lipoprotein composition. Dysferlinopathic patients may be dyslipidemic without greater atherosclerotic burden while remaining responsive to cholesterol absorption blockade.

Aortic Endarterectomy for Aortic Occlusive Disease: An Old Operation With a Re-emerging Role

Introduction: Descending aortic complex atheromatous plaques can cause claudication, critical lower limb ischaemia (CLI), and are an independent risk factor for systemic embolization. Current practice involves dealing with most cases using endovascular techniques. However, open repair remains superior in terms of the patency rates and may be the only valid option in a subgroup of patients who are unsuitable for endovascular treatments. Most of the current data investigating open procedures are now historic. The aim of this study is to determine whether it is a feasible option in the current day practice. Patients and methods: Ten years data from 2010 to 2020 were collected retrospectively from the hospital records. Clinic letters, radiologic scans, operative records and discharge letters were reviewed. Death records were reviewed to identify patients who survived. Results: Ten cases were identified. The average age was 55 and the mean BMI was 29.4. The mean hospital stay in days was 12 (range: 4 to 22). The mean follow-up period was 147 days (range: 30 to 360 days). Four of the patients were TASC B, four were TASC C and two were TASC D. Two cases had to return to theatres. One patient had transient post-op AF and another had transient post-op ileus. One patient was readmitted within 30 days of discharge for urosepsis. All cases are alive to date except one case which only survived three years after procedure. Conclusion: AE is a procedure that should be considered in selected cases where endovascular approach is not feasible. There is a trend towards lower mortality than the historic data available in literature. Larger case series or registry data may be required to accurately estimate the current day mortality and morbidity figures.

Ferryl Hemoglobin and Heme Induce Α1-Microglobulin in Hemorrhaged Atherosclerotic Lesions with Inhibitory Function against Hemoglobin and Lipid Oxidation

Infiltration of red blood cells into atheromatous plaques and oxidation of hemoglobin (Hb) and lipoproteins are implicated in the pathogenesis of atherosclerosis. α1-microglobulin (A1M) is a radical-scavenging and heme-binding protein. In this work, we examined the origin and role of A1M in human atherosclerotic lesions. Using immunohistochemistry, we observed a significant A1M immunoreactivity in atheromas and hemorrhaged plaques of carotid arteries in smooth muscle cells (SMCs) and macrophages. The most prominent expression was detected in macrophages of organized hemorrhage. To reveal a possible inducer of A1M expression in ruptured lesions, we exposed aortic endothelial cells (ECs), SMCs and macrophages to heme, Oxy- and FerrylHb. Both heme and FerrylHb, but not OxyHb, upregulated A1M mRNA expression in all cell types. Importantly, only FerrylHb induced A1M protein secretion in aortic ECs, SMCs and macrophages. To assess the possible function of A1M in ruptured lesions, we analyzed Hb oxidation and heme-catalyzed lipid peroxidation in the presence of A1M. We showed that recombinant A1M markedly inhibited Hb oxidation and heme-driven oxidative modification of low-density lipoproteins as well plaque lipids derived from atheromas. These results demonstrate the presence of A1M in atherosclerotic plaques and suggest its induction by heme and FerrylHb in the resident cells.

Identification of Periopathogens in Atheromatous Plaques Obtained from Carotid and Coronary Arteries

Increasing attention has been paid to the possible link between periodontal disease and atherosclerosis over the past decade. The aim of this study is to investigate the presence of five periopathogens: Porphyromonas gingivalis (P.g.), Aggregatibacter actinomycetemcomitans (A.a.), Tannerella forsythia (T.f.), Treponema denticola (T.d.), and Prevotella intermedia (P.i.) in atheromatous plaques obtained from the carotid and coronary arteries in patients who underwent coronary artery bypass graft surgery and carotid endarterectomy. Group I (carotid arteries) consisted of 30 patients (mean age: 54.5 ± 14.8 ), and group II (coronary arteries) consisted of 28 patients (mean age: 63 ± 12.1 ). Clinical periodontal examinations consisted of plaque index, gingival index, sulcus bleeding index, and periodontal probing depth and were performed on the day of vascular surgery. The presence of periopathogens in periodontal pockets and atherosclerotic vessels was detected using polymerase chain reaction. In both subgingival plaque and atherosclerotic plaque of carotid arteries, P.g., A.a., T.f., T.d., and P.i. were detected in 26.7%, 6.7%, 66.7%, 10.0%, and 20.0%, respectively, while for coronary arteries, P.g. was detected in 39.3%, A.a. in 25%, T.f. in 46.4%, T.d. in 7.1%, and P.i. in 35.7%. The presence of five periopathogens in carotid and coronary atherosclerotic vessels showed correlation in regard to the degree of periodontal inflammation. The present study suggests the relationship between periodontal pathogenic bacteria and atherogenesis. Further studies are necessary in relation to the prevention or treatment of periodontal disease that would result in reduced mortality and morbidity associated with atherosclerosis.