The role of HDL in plaque stabilization and regression: basic mechanisms and clinical implications

Risk of Ischemic Stroke in Relation to Helicobacter pylori Infection and Eradication Status: A Large-Scale Prospective Observational Cohort Study

Background/Aims

: A few studies have suggested the association between Helicobacter pylori (HP) infection and ischemic stroke. However, the impact of HP eradication on stroke risk has not been well evaluated. This study aimed to assess the influence of HP eradication on the incidence of ischemic stroke, considering the potential effect of sex.

Methods

: This prospective observational cohort study was conducted at Seoul National University Bundang Hospital, from May 2003 to February 2023, and involved gastroscopy-based HP testing. Propensity score (PS) matching was employed to ensure balanced groups by matching patients in the HP eradicated group (n=2,803) in a 3:1 ratio with patients in the HP non-eradicated group (n=960). Cox proportional hazard regression analysis was used to evaluate the risk of ischemic stroke.

Results

: Among 6,664 patients, multivariate analysis after PS matching indicated that HP eradication did not significantly alter the risk of ischemic stroke (hazard ratio, 0.531; 95% confidence interval, 0.221 to 1.270; p=0.157). Sex-specific subgroup analyses, both univariate and multivariate, did not yield statistically significant differences. However, Kaplan-Meier analysis revealed a potential trend: the females in the HP eradicated group exhibited a lower incidence of ischemic stroke than those in the HP non-eradicated group, although this did not reach statistical significance (p=0.057).

Conclusions

: This finding suggests that HP eradication might not impact the risk of ischemic stroke. However, there was a trend showing that females potentially had a lower risk of ischemic stroke following HP eradication, though further investigation is required to establish definitive evidence.

Apolipoproteins as potential communicators play an essential role in the pathogenesis and treatment of early atherosclerosis

Atherosclerosis as the leading cause of the cardiovascular disease is closely related to cholesterol deposition within subendothelial areas of the arteries. Significantly, early atherosclerosis intervention is the critical phase for its reversal. As atherosclerosis progresses, early foam cells formation may evolve into fibrous plaques and atheromatous plaque, ulteriorly rupture of atheromatous plaque increases risks of myocardial infarction and ischemic stroke, resulting in high morbidity and mortality worldwide. Notably, amphiphilic apolipoproteins (Apos) can concomitantly combine with lipids to form soluble lipoproteins that have been demonstrated to associate with atherosclerosis. Apos act as crucial communicators of lipoproteins, which not only can mediate lipids metabolism, but also can involve in pro-atherogenic and anti-atherogenic processes of atherosclerosis via affecting subendothelial retention and aggregation of low-density lipoprotein (LDL), oxidative modification of LDL, foam cells formation and reverse cholesterol transport (RCT) in macrophage cells. Correspondingly, Apos can be used as endogenous and/or exogenous targeting agents to effectively attenuate the development of atherosclerosis. The article reviews the classification, structure, and relationship between Apos and lipids, how Apos serve as communicators of lipoproteins to participate in the pathogenesis progression of early atherosclerosis, as well as how Apos as the meaningful targeting mass is used in early atherosclerosis treatment.

The Effectiveness and Safety of Intensive Lipid-Lowering with Different Rosuvastatin-Based Regimens in Patients at High Cardiovascular Disease Risk: A Nonblind, Randomized, Controlled Trial

Background

A statin alone or non-statins as add-ons have been introduced to intensive low-density lipoprotein cholesterol (LDL-C) -lowering therapy in patients at risk for high cardiovascular disease (CVD). The purpose of this study was to evaluate the effectiveness and safety of different rosuvastatin-based regimens for patients at high risk.

Methods

Three hundred patients at high CVD risk were randomly assigned to the statin group (rosuvastatin, 20 mg/d), statin_EZ group (statin 10 mg/d + ezetimibe 10 mg/d), statin_pcsk group (statin 10 mg/d + alirocumab 75 mg/2 weeks) or combine3 group (statin 10 mg/d + ezetimibe 10 mg/d + alirocumab 75 mg/2 weeks). The primary outcome measure was cholesterol levels after 24 weeks of follow-up. Secondary outcomes included safety markers and the proportion of patients achieving the 70 mg/dL (1.8 mmol/L) target for LDL-C. A logistic regression model was performed to explore the factors affecting lipid target achievement.

Results

The total cholesterol (TC) and LDL-C levels in the four groups after treatment were significantly lower than those before treatment. TC and LDL-C levels after treatment were significantly different among the four groups (p < 0.05). The levels in both the combine3 and statin_pcsk9 groups were significantly lower than those in the statin and statin_EZ groups (p < 0.05), but there was no significant difference between the combine3 and statin_pcsk9 groups. Fifty-one participants (69%) in the statin_pcsk9 group and 56 participants (78%) in the combine3 group achieved the target. Body mass index (BMI) and hypertensive status were related to LDL-C target achievement. The incidence of adverse events in the four groups was low.

Conclusions

The combination of a statin and a PCSK9 inhibitor was safe and more effective for the treatment of high-risk CVD patients, while the addition of ezetimibe was unable to significantly lower lipid levels any further. The rate of achieving the target was higher in patients with hypertension and a low BMI.

Clinical Trial Registration

Chinese Clinical Trial Registry, Identifier: ChiCTR2200058389, Date of Registration: 2022-04-08.

HDL-Based Therapy: Vascular Protection at All Stages

It is known that lipid metabolism disorders are involved in a wide range of pathologies. These pathologies include cardiovascular, metabolic, neurodegenerative diseases, and even cancer. All these diseases lead to serious health consequences, which makes it impossible to ignore them. Unfortunately, these diseases most often have a complex pathogenesis, which makes it difficult to study them and, in particular, diagnose and treat them. HDL is an important part of lipid metabolism, performing many functions under normal conditions. One of such functions is the maintaining of the reverse cholesterol transport. These functions are also implicated in pathology development. Thus, HDL contributes to vascular protection, which has been demonstrated in various conditions: Alzheimer’s disease, atherosclerosis, etc. Many studies have shown that serum levels of HDL cholesterol correlate negatively with CV risk. With these data, HDL-C is a promising therapeutic target. In this manuscript, we reviewed HDL-based therapeutic strategies that are currently being used or may be developed soon.

On the Aggregation of Apolipoprotein A-I

In vivo, apolipoprotein A-I (ApoA-I) is commonly found together with lipids in so-called lipoprotein particles. The protein has also been associated with several diseases—such as atherosclerosis and amyloidosis—where insoluble aggregates containing ApoA-I are deposited in various organs or arteries. The deposited ApoA-I has been found in the form of amyloid fibrils, suggesting that amyloid formation may be involved in the development of these diseases. In the present study we investigated ApoA-I aggregation into amyloid fibrils and other aggregate morphologies. We studied the aggregation of wildtype ApoA-I as well as a disease-associated mutant, ApoA-I K107Δ, under different solution conditions. The aggregation was followed using thioflavin T fluorescence intensity. For selected samples the aggregates formed were characterized in terms of size, secondary structure content, and morphology using circular dichroism spectroscopy, dynamic light scattering, atomic force microscopy and cryo transmission electron microscopy. We find that ApoA-I may form globular protein-only condensates, in which the α-helical conformation of the protein is retained. The protein in its unmodified form appears resistant to amyloid formation; however, the conversion into amyloid fibrils rich in β-sheet is facilitated by oxidation or mutation. In particular, the K107Δ mutant shows higher amyloid formation propensity, and the end state appears to be a co-existence of β-sheet rich amyloid fibrils and α-helix-rich condensates.

Monocyte/High-Density Lipoprotein Ratio Predicts the Prognosis of Large Artery Atherosclerosis Ischemic Stroke

Objective: Monocyte to high-density lipoprotein ratio is considered as a new inflammatory marker and has been used to predict the severity of coronary heart disease and the incidence of adverse cardiovascular events (ACEs). However, there is a lack of data relative to large artery atherosclerosis (LAA) ischemic stroke. We investigated whether the monocyte to high-density lipoprotein (HDL) ratio (MHR) is related to the 3-month functional prognosis of LAA ischemic stroke.

Materials and Methods: A retrospective analysis was conducted on 316 LAA ischemic stroke patients. The 3-month functional outcome was divided into good and poor according to the modified Rankin Scale (mRS) score. Multivariate logistic regression analysis was performed to evaluate the correlation between MHR and prognosis of ischemic stroke.

Results: The MHR level of poor functional outcome group was higher than that of the good functional outcome group [0.44 (0.3, 0.55) vs. 0.38 (0.27, 0.5), P = 0.025]. Logistic stepwise multiple regression revealed that MHR [odds ratio (OR) 9.464, 95%CI 2.257–39.678, P = 0.002] was an independent risk factor for the 3-month poor outcome of LAA ischemic stroke. Compared to the lower MHR tertile, the upper MHR tertile had a 3.03-fold increase (95% CI 1.475–6.225, P = 0.003) in the odds of poor functional outcome after adjustment for potential confounders. Moreover, a multivariable-adjusted restricted cubic spline (RCS) showed a positive close to a linear pattern of this association.

Conclusion: Elevated MHR was independently associated with an increased risk of poor 3-month functional outcome of patients with LAA ischemic stroke.

Intestinal and Hepatic Uptake of Dietary Peroxidized Lipids and Their Decomposition Products, and Their Subsequent Effects on Apolipoprotein A1 and Paraoxonase1

Both pro- and antiatherosclerotic effects have been ascribed to dietary peroxidized lipids. Confusion on the role of peroxidized lipids in atherosclerotic cardiovascular disease is punctuated by a lack of understanding regarding the metabolic fate and potential physiological effects of dietary peroxidized lipids and their decomposition products. This study sought to determine the metabolic fate and physiological ramifications of 13-hydroperoxyoctadecadienoic acid (13-HPODE) and 13-HODE (13-hydroxyoctadecadienoic acid) supplementation in intestinal and hepatic cell lines, as well as any effects resulting from 13-HPODE or 13-HODE degradation products. In the presence of Caco-2 cells, 13-HPODE was rapidly reduced to 13-HODE. Upon entering the cell, 13-HODE appears to undergo decomposition, followed by esterification. Moreover, 13-HPODE undergoes autodecomposition to produce aldehydes such as 9-oxononanoic acid (9-ONA). Results indicate that 9-ONA was oxidized to azelaic acid (AzA) rapidly in cell culture media, but AzA was poorly absorbed by intestinal cells and remained detectable in cell culture media for up to 18 h. An increased apolipoprotein A1 (ApoA1) secretion was observed in Caco-2 cells in the presence of 13-HPODE, 9-ONA, and AzA, whereas such induction was not observed in HepG2 cells. However, 13-HPODE treatments suppressed paraoxonase 1 (PON1) activity, suggesting the induction of ApoA1 secretion by 13-HPODE may not represent functional high-density lipoprotein (HDL) capable of reducing oxidative stress. Alternatively, AzA induced both ApoA1 secretion and PON1 activity while suppressing ApoB secretion in differentiated Caco-2 cells but not in HepG2. These results suggest oxidation of 9-ONA to AzA might be an important phenomenon, resulting in the accumulation of potentially beneficial dietary peroxidized lipid-derived aldehydes.

Biomarker Discovery in Atherosclerotic Diseases Using Quantitative Nuclear Magnetic Resonance Metabolomics

Despite great progress in the management of atherosclerosis (AS), its subsequent cardiovascular disease (CVD) remains the leading cause of morbidity and mortality. This is probably due to insufficient risk detection using routine lipid testing; thus, there is a need for more effective approaches relying on new biomarkers. Quantitative nuclear magnetic resonance (qNMR) metabolomics is able to phenotype holistic metabolic changes, with a unique advantage in regard to quantifying lipid-protein complexes. The rapidly increasing literature has indicated that qNMR-based lipoprotein particle number, particle size, lipid components, and some molecular metabolites can provide deeper insight into atherogenic diseases and could serve as novel promising determinants. Therefore, this article aims to offer an updated review of the qNMR biomarkers of AS and CVD found in epidemiological studies, with a special emphasis on lipoprotein-related parameters. As more researches are performed, we can envision more qNMR metabolite biomarkers being successfully translated into daily clinical practice to enhance the prevention, detection and intervention of atherosclerotic diseases.

JTP-109192, a novel G protein-coupled receptor 119 agonist, prevents atherosclerosis by improving hypercholesterolaemia in congenic spontaneously hyperlipidaemic mice

G protein-coupled receptor 119 (GPR119) expression in pancreatic β-cells and intestinal L-cells is a potential therapeutic target for the treatment of type 2 diabetes. Previously, we have reported that the GPR119 agonist JTP-109192 improves glucose metabolism with single and repeated administration. Conversely, overexpression of the Gpr119 gene reportedly regulates cholesterol transporter expression in animal models, and a natural GPR119 agonist, oleoylethanolamide (OEA), improves atherosclerosis. Therefore, improving dyslipidaemia is considered a possible feature of GPR119 agonists. In the present study, the lipid-lowering effect of JTP-109192 was examined in BALB/c background spontaneously hyperlipidaemic (SHL) mice with repeated administration, once daily for 12 weeks. On repeated administration, JTP-109192 revealed a cholesterol-lowering effect and improved atherosclerosis following histopathological examination. With further investigation, the cholesterol-lowering effect and subsequent antiatherosclerotic effect of JTP-109192 was attributed to changes in intestinal cholesterol metabolism gene expression. Based on these results, JTP-109192 represents a new potential antihypercholesterolaemic agent for the treatment of dyslipidaemia.

Regional Variation in Genetic Control of Atherosclerosis in Hyperlipidemic Mice

Atherosclerosis is a polygenic disorder that often affects multiple arteries. Carotid arteries are common sites for evaluating subclinical atherosclerosis, and aortic root is the standard site for quantifying atherosclerosis in mice. We compared genetic control of atherosclerosis between the two sites in the same cohort derived from two phenotypically divergent Apoe-null (Apoe ^-/-) mouse strains. Female F2 mice were generated from C57BL/6 (B6) and C3H/He (C3H) Apoe ^-/- mice and fed 12 weeks of Western diet. Atherosclerotic lesions in carotid bifurcation and aortic root and plasma levels of fasting lipids and glucose were measured. 153 genetic markers across the genome were typed. All F2 mice developed aortic atherosclerosis, while 1/5 formed no or little carotid lesions. Genome-wide scans revealed 3 significant loci on chromosome (Chr) 1, Chr15, 6 suggestive loci for aortic atherosclerosis, 2 significant loci on Chr6, Chr12, and 6 suggestive loci for carotid atherosclerosis. Only 2 loci for aortic lesions showed colocalization with loci for carotid lesions. Carotid lesion sizes were moderately correlated with aortic lesion sizes (r = 0.303; P = 4.6E-6), but they showed slight or no association with plasma HDL, non-HDL cholesterol, triglyceride, or glucose levels among F2 mice. Bioinformatics analyses prioritized Cryge as a likely causal gene for Ath30, Cdh6 and Dnah5 as causal genes for Ath22 Our data demonstrate vascular site-specific effects of genetic factors on atherosclerosis in the same animals and highlight the need to extend studies of atherosclerosis to sites beyond aortas of mice.

Cardioprotective Properties of HDL: Structural and Functional Considerations

BACKGROUND

As Mendelian Randomization (MR) studies showed no effect of variants altering HDL-cholesterol (HDL-C) levels concerning Cardiovascular Disease (CVD) and novel therapeutic interventions aiming to raise HDL-C resulted to futility, the usefulness of HDL-C is unclear.

OBJECTIVE

As the role of HDL-C is currently doubtful, it is suggested that the atheroprotective functions of HDLs can be attributed to the number of HDL particles, and their characteristics including their lipid and protein components. Scientific interest has focused on HDL function and on the causes of rendering HDL particles dysfunctional, whereas the relevance of HDL subclasses with CVD remains controversial.

METHODS

The present review discusses changes in quality as much as in quantity of HDL in pathological conditions and the connection between HDL particle concentration and cardiovascular disease and mortality. Emphasis is given to the recently available data concerning the cholesterol efflux capacity and the parameters that determine HDL functionality, as well as to recent investigations concerning the associations of HDL subclasses with cardiovascular mortality.

RESULTS

MR studies or pharmacological interventions targeting HDL-C are not in favor of the hypothesis of HDL-C levels and the relationship with CVD. The search of biomarkers that relate with HDL functionality is needed. Similarly, HDL particle size and number exhibit controversial data in the context of CVD and further studies are needed.

CONCLUSION

There is no room for the old concept of HDL as a silver bullet,as HDL-C cannot be considered a robust marker and does not reflect the importance of HDL particle size and number. Elucidation of the complex HDL system, as well as the finding of biomarkers, will allow the development of any HDL-targeted therapy.

Myeloperoxidase As a Multifaceted Target for Cardiovascular Protection

Significance: Myeloperoxidase (MPO) is a heme peroxidase that is primarily expressed by neutrophils. It has the capacity to generate several reactive species, essential for its inherent antimicrobial activity and innate host defense. Dysregulated MPO release, however, can lead to tissue damage, as seen in several diseases. Increased MPO levels in circulation are therefore widely associated with conditions of increased oxidative stress and inflammation. Recent Advances: Several studies have shown a strong correlation between MPO and cardiovascular disease (CVD), through which elevated levels of circulating MPO are linked to poor prognosis with increased risk of CVD-related mortality. Accordingly, circulating MPO is considered a "high-risk" biomarker for patients with acute coronary syndrome, atherosclerosis, heart failure, hypertension, and stroke, thereby implicating MPO as a multifaceted target for cardiovascular protection. Consistently, recent studies that target MPO in animal models of CVD have demonstrated favorable outcomes with regard to disease progression. Critical Issues: Although most of these studies have established a critical link between circulating MPO and worsening cardiac outcomes, the mechanisms by which MPO exerts its detrimental effects in CVD remain unclear. Future Directions: Elucidating the mechanisms by which elevated MPO leads to poor prognosis and, conversely, investigating the beneficial effects of therapeutic MPO inhibition on alleviating disease phenotype will facilitate future MPO-targeted clinical trials for improving CVD-related outcomes.

Carotid and Femoral Atherosclerotic Plaques in Asymptomatic and Non-Treated Subjects: Cardiovascular Risk Factors, 10-Years Risk Scores, and Lipid Ratios´ Capability to Detect Plaque Presence, Burden, Fibro-Lipid Composition and Geometry

Carotid and/or femoral atherosclerotic plaques (AP) assessment through imaging studies is an interesting strategy for improving individual cardiovascular risk (CVR) stratification and cardiovascular disease (CVD) and/or events prediction. There is no consensus on who would benefit from image screening aimed at determining AP presence, burden, and characteristics.

AIMS

(1) to identify, in asymptomatic and non-treated subjects, demographic factors, anthropometric characteristics and cardiovascular risk factors (CRFs), individually or grouped (e.g., CVR equations, pro-atherogenic lipid ratios) associated with carotid and femoral AP presence, burden, geometry, and fibro-lipid content; (2) to identify cut-off values to be used when considering the variables as indicators of increased probability of AP presence, elevated atherosclerotic burden, and/or lipid content, in a selection scheme for subsequent image screening.

METHODS

CRFs exposure and clinical data were obtained (n = 581; n = 144 with AP; 47% females). Arterial (e.g., ultrasonography) and hemodynamic (central [cBP] and peripheral blood pressure; oscillometry/applanation tonometry) data were obtained. Carotid and femoral AP presence, burden (e.g., AP number, involved territories), geometric (area, width, height) and fibro-lipid content (semi-automatic, virtual histology analysis, grayscale analysis and color mapping) were assessed. Lipid profile was obtained. Lipid ratios (Total cholesterol/HDL-cholesterol, LDL-cholesterol/HDL-cholesterol, LogTryglicerides(TG)/HDL-cholesterol) and eight 10-years [y.]/CVR scores were quantified (e.g., Framingham Risk Scores [FRS] for CVD).

RESULTS

Age, 10-y./CVR and cBP showed the highest levels of association with AP presence and burden. Individually, classical CRFs and lipid ratios showed almost no association with AP presence. 10-y./CVR levels, age and cBP enabled detecting AP with large surfaces (˃p75th). Lipid ratios showed the largest association with AP fibro-lipid content. Ultrasound evaluation could be considered in asymptomatic and non-treated subjects aiming at population screening of AP (e.g., ˃ 45 y.; 10-y./FRS-CVD ˃ 5-8%); identifying subjects with high atherosclerotic burden (e.g., ˃50 y., 10-y./FRS-CVD ˃ 13-15%) and/or with plaques with high lipid content (e.g., LogTG/HDL ˃ 0.135).

Regression of atherosclerosis: lessons learned from genetically modified mouse models

PURPOSE OF REVIEW

Regression, or reversal, of atherosclerosis has become an important clinical objective. The development of consistent models of murine atherosclerosis regression has accelerated this field of research. The purpose of this review is to highlight recent mouse studies that reveal molecular mechanisms as well as therapeutics targeted for regression.

RECENT FINDINGS

Atherosclerosis regression does not involve the same mechanisms as progression in reverse order. Distinct molecular processes within the plaque characterize regression. These processes remained elusive until the advent of murine regression models including aortic transplant, the Reversa mouse, gene complementation and dietary intervention. Studies revealed that depletion of plaque macrophages is a quintessential characteristic of regression, driven by reduced monocyte recruitment into plaques, increased egress of macrophages from plaques and reduced macrophage proliferation. In addition, regression results in polarization of remaining plaque macrophages towards an anti-inflammatory phenotype, smaller necrotic cores and promotion of an organized fibrous cap. Furthermore, type 1 diabetes hinders plaque regression, and several therapeutic interventions show promise in slowing plaque progression or inducing regression.

SUMMARY

Mouse models of atherosclerosis regression have accelerated our understanding of the molecular mechanisms governing lesion resolution. These insights will be valuable in identifying therapeutic targets aimed at atherosclerosis regression.

What We Have Learned from the Recent Meta-analyses on Diagnostic Methods for Atherosclerotic Plaque Regression

PURPOSE OF REVIEW

Atherosclerosis has major morbidity and mortality implications globally. While it has often been considered an irreversible degenerative process, recent evidence provides compelling proof that atherosclerosis can be reversed. Plaque regression is however difficult to appraise and quantify, with competing diagnostic methods available. Given the potential of evidence synthesis to provide clinical guidance, we aimed to review recent meta-analyses on diagnostic methods for atherosclerotic plaque regression.

RECENT FINDINGS

We identified 8 meta-analyses published between 2015 and 2017, including 79 studies and 14,442 patients, followed for a median of 12 months. They reported on atherosclerotic plaque regression appraised with carotid duplex ultrasound, coronary computed tomography, carotid magnetic resonance, coronary intravascular ultrasound, and coronary optical coherence tomography. Overall, all meta-analyses showed significant atherosclerotic plaque regression with lipid-lowering therapy, with the most notable effects on echogenicity, lipid-rich necrotic core volume, wall/plaque volume, dense calcium volume, and fibrous cap thickness. Significant interactions were found with concomitant changes in low density lipoprotein cholesterol, high density lipoprotein cholesterol, and C-reactive protein levels, and with ethnicity. Atherosclerotic plaque regression and conversion to a stable phenotype is possible with intensive medical therapy and can be demonstrated in patients using a variety of non-invasive and invasive imaging modalities.