Conquering Atherosclerotic Cardiovascular Disease - 50 Years of Progress

Nobiletin alleviates atherosclerosis by inhibiting lipid uptake via the PPARG/CD36 pathway

BACKGROUND

Atherosclerosis (AS) is a persistent inflammatory condition triggered and exacerbated by several factors including lipid accumulation, endothelial dysfunction and macrophages infiltration. Nobiletin (NOB) has been reported to alleviate atherosclerosis; however, the underlying mechanism remains incompletely understood.

METHODS

This study involved comprehensive bioinformatic analysis, including multidatabase target prediction; GO and KEGG enrichment analyses for function and pathway exploration; DeepSite and AutoDock for drug binding site prediction; and CIBERSORT for immune cell involvement. In addition, target intervention was verified via cell scratch assays, oil red O staining, ELISA, flow cytometry, qRT‒PCR and Western blotting. In addition, by establishing a mouse model of AS, it was demonstrated that NOB attenuated lipid accumulation and the extent of atherosclerotic lesions.

RESULTS

(1) Altogether, 141 potentially targetable genes were identified through which NOB could intervene in atherosclerosis. (2) Lipid and atherosclerosis, fluid shear stress and atherosclerosis may be the dominant pathways and potential mechanisms. (3) ALB, AKT1, CASP3 and 7 other genes were identified as the top 10 target genes. (4) Six genes, including PPARG, MMP9, SRC and 3 other genes, were related to the M0 fraction. (5) CD36 and PPARG were upregulated in atherosclerosis samples compared to the normal control. (6) By inhibiting lipid uptake in RAW264.7 cells, NOB prevents the formation of foam cell. (7) In RAW264.7 cells, the inhibitory effect of oxidized low-density lipoprotein on foam cells formation and lipid accumulation was closely associated with the PPARG signaling pathway. (8) In vivo validation showed that NOB significantly attenuated intra-arterial lipid accumulation and macrophage infiltration and reduced CD36 expression.

CONCLUSIONS

Nobiletin alleviates atherosclerosis by inhibiting lipid uptake via the PPARG/CD36 pathway.

Exposome in ischaemic heart disease: beyond traditional risk factors

Ischaemic heart disease represents the leading cause of morbidity and mortality, typically induced by the detrimental effects of risk factors on the cardiovascular system. Although preventive interventions tackling conventional risk factors have helped to reduce the incidence of ischaemic heart disease, it remains a major cause of death worldwide. Thus, attention is now shifting to non-traditional risk factors in the built, natural, and social environments that collectively contribute substantially to the disease burden and perpetuate residual risk. Of importance, these complex factors interact non-linearly and in unpredictable ways to often enhance the detrimental effects attributable to a single or collection of these factors. For this reason, a new paradigm called the 'exposome' has recently been introduced by epidemiologists in order to define the totality of exposure to these new risk factors. The purpose of this review is to outline how these emerging risk factors may interact and contribute to the occurrence of ischaemic heart disease, with a particular attention on the impact of long-term exposure to different environmental pollutants, socioeconomic and psychological factors, along with infectious diseases such as influenza and COVID-19. Moreover, potential mitigation strategies for both individuals and communities will be discussed.

Impact of particulate matter on the incidence of atrial fibrillation and the risk of adverse clinical outcomes: A review

BACKGROUND

Atrial fibrillation (AF) is common and increases the risk of stroke and mortality. Previous studies have suggested that air pollution is an important risk factor for new-onset AF. Herein, we review the evidence regarding: 1) the association between exposure to particulate matter (PM) and new-onset AF, and 2) the risk of worse clinical outcomes in patients with pre-existent AF and their relation to PM exposure.

METHODS

A selection of studies between 2000 and 2023 linking PM exposure and AF was performed through searches in PubMed, Scopus, Web of Science, and Google Scholar.

RESULTS

17 studies from different geographical areas demonstrated that exposure to PM was associated with an increased risk of new-onset AF, although the results were heterogeneous regarding the temporal pattern (short- or long-term) ultimately related to AF. Most of the studies concluded that the risk of new-onset AF increased between 2 %-18 % per 10 μg/m³ increment in PM_2.5 or PM₁₀ concentrations, whereas the incidence (percentage of change of incidence) increased between 0.29 %-2.95 % per 10 μg/m³ increment in PM_2.5 or PM₁₀. Evidence about the association between PM and adverse events in patients with pre-existent AF was scarce but 4 studies showed a higher risk of mortality and stroke (between 8 %-64 % in terms of hazard ratio) in patients with pre-existent AF when PM exposure was higher.

CONCLUSIONS

Exposure to PM (both PM_2.5 and PM₁₀) is a risk factor for AF, and a risk factor for mortality and stroke in patients who already suffer from AF. Since the relationship between PM and AF is independent of the region of the world, PM should be considered as a global risk factor for both AF and worse clinical outcomes in AF patients. Specific measures to prevent air pollution exposure need to be adopted.

Impact of air pollution on ischemic heart disease: Evidence, mechanisms, clinical perspectives

Ambient air pollution, and especially particulate matter (PM) air pollution <2.5 μm in diameter (PM_2.5), has clearly emerged as an important yet often overlooked risk factor for atherosclerosis and ischemic heart disease (IHD). In this review, we examine the available evidence demonstrating how acute and chronic PM_2.5 exposure clinically translates into a heightened coronary atherosclerotic burden and an increased risk of acute ischemic coronary events. Moreover, we provide insights into the pathophysiologic mechanisms underlying PM_2.5-mediated atherosclerosis, focusing on the specific biological mechanism through which PM_2.5 exerts its detrimental effects. Further, we discuss about the possible mechanisms that explain the recent findings reporting a strong association between severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, increased PM_2.5 exposure, and morbidity and mortality from IHD. We also address the possible mitigation strategies that should be implemented to reduce the impact of PM_2.5 on cardiovascular morbidity and mortality, and underscoring the strong need of clinical trials demonstrating the efficacy of specific interventions (including both PM_2.5 reduction and/or specific drugs) in reducing the incidence of IHD. Finally, we introduce the emerging concept of the exposome, highlighting the close relationship between PM_2.5 and other environmental exposures (i.e.: traffic noise and climate change) in terms of common underlying pathophysiologic mechanisms and possible mitigation strategies.

State-level disparities in burden of ischemic heart diseases mortality attributable to ambient fine particulate matter in the United States, 1990-2019: Observational analysis for the Global Burden of Disease (2019) study

BACKGROUND

ambient fine particulate air pollution (PM2.5) is an important yet often overlooked risk factor for cardiovascular disease in the United States. However, epidemiologic evidence suggests that current knowledge does not comprehensively capture state-level disparities in mortality for ambient PM2.5-related ischemic heart diseases.

METHODS

I performed serial cross sectional analysis with ambient PM2.5-attributable ischemic heart diseases decedents between 1990 and 2019. I used the Global Health Data Exchange to extract age adjusted mortality rates in each state, and used Joinpoint software to calculate average annual percentage change.

RESULTS

the average age adjusted mortality rates (AAMR) for ischemic heart diseases attributable to ambient PM2.5 for both sex ranged from 1.5 (1.3-1.8) per 100,000 in Hawaii to 1.1 (0.9-1.3) per 100,000 in Mississippi, respectively. The rate of change in AAMR varied widely across states. Compared with the national level, the number of states with smaller decline has increased from 3 before 2002 to 10 after 2011. Oregon, Idaho, and Montana showed an upward trend in AAMR, which was independent of sex after 2011. Between 1990 and 2019, average AAMR for ischemic heart diseases attributable to ambient PM2.5 was higher for male than female in all states. But the number of states with sex disparities in the rate of change has decreased, from 13 in 1990-2002 to 5 after 2011.

CONCLUSIONS

wide state-level disparities exist in burden of ischemic heart diseases attributable to ambient PM2.5. After 2011, the association between rate of AAMR decline and sex weakened across states. State-level policies and programs are needed to address the avoidable burden of ischemic heart diseases deaths attributable to ambient particulate pollution, with priority for states with a higher burden.

Air Pollution and the Heart: Updated Evidence from Meta-analysis Studies

PURPOSE OF REVIEW

Although environmental exposure such as air pollution is detrimental to cardiovascular disease (CVD), the effects of different air pollutants on different CVD endpoints produced variable findings. We provide updated evidence between air pollutants and CVD outcomes including mitigation strategies with meta-analytic evidence.

RECENT FINDINGS

An increased exposure to any class of air pollutants including particulate matter (PM), gas, toxic metals, and disruptive chemicals has been associated with CVD events. Exposure to PM < 2.5 μm has been consistently associated with most heart diseases and stroke as well as CVDs among at-risk individuals. Despite this, there is no clinical approach available for systemic evaluation of air pollution exposure and management. A large number of epidemiological evidence clearly suggests the importance of air pollution prevention and control for reducing the risk of CVDs and mortality. Cost-effective and feasible strategies for air pollution monitoring, screening, and necessary interventions are urgently required among at-risk populations and those living or working, or frequently commuting in polluted areas.

Assessment of Atherosclerotic Cardiovascular Disease Risk in Primary Prevention

PURPOSE

The objective of this report was to review the application of the pooled cohort equations in primary prevention and the assessment of cardiovascular health.

REVIEW METHODS

Literature review was conducted using the PubMed database. In addition, the 2018 Multi-Society Guidelines on Management of Blood Cholesterol and the 2019 American College of Cardiology/American Heart Association Guidelines on the Primary Prevention of Cardiovascular Disease were reviewed.

SUMMARY

Primary prevention refers to individuals with no history of atherosclerotic cardiovascular disease, severe hypercholesterolemia, or diabetes. For these adults, aged 40-75 yr, who have a low-density lipoprotein-cholesterol of ≥70 mg/dL and <190 mg/dL, the pooled cohort equations should be used to provide a quantitative assessment of 10-yr atherosclerotic cardiovascular disease risk. From here, individuals are grouped as low risk (<5%), borderline risk (5 to <7.5%), intermediate risk (7.5 to <20%), or high risk (≥20%). Statin therapy should be strongly advised in those with an atherosclerotic cardiovascular disease risk of ≥20%, while statin therapy can be considered in those with a risk between 5% and <20%, especially if risk enhancing factors are present. If uncertainty still exists regarding treatment, a coronary artery calcium score can help further refine risk. All individuals, regardless of atherosclerotic cardiovascular disease risk, should have a cardiovascular health assessment using Life's Essential 8, which includes diet, physical activity, nicotine exposure, body mass index, blood glucose, blood lipids, blood pressure, and sleep.

Anti-atherosclerotic therapies: Milestones, challenges, and emerging innovations

Atherosclerosis is the main underlying pathology for many cardiovascular diseases (CVDs), which are the leading cause of death globally and represent a serious health crisis. Atherosclerosis is a chronic condition that can lead to myocardial infarction, ischemic cardiomyopathy, stroke, and peripheral arterial disease. Elevated plasma lipids, hypertension, and high glucose are the major risk factors for developing atherosclerotic plaques. To date, most pharmacological therapies aim to control these risk factors, but they do not target the plaque-causing cells themselves. In patients with acute coronary syndromes, surgical revascularization with percutaneous coronary intervention has greatly reduced mortality rates. However, stent thrombosis and neo-atherosclerosis have emerged as major safety concerns of drug eluting stents due to delayed re-endothelialization. This review summarizes the major milestones, strengths, and limitations of current anti-atherosclerotic therapies. It provides an overview of the recent discoveries and emerging game-changing technologies in the fields of nanomedicine, mRNA therapeutics, and gene editing that have the potential to revolutionize CVD clinical practice by steering it toward precision medicine.

Population study of the gut microbiome: associations with diet, lifestyle, and cardiometabolic disease

BACKGROUND

The human gut harbors trillions of microbes that play dynamic roles in health. While the microbiome contributes to many cardiometabolic traits by modulating host inflammation and metabolism, there is an incomplete understanding regarding the extent that and mechanisms by which individual microbes impact risk and development of cardiovascular disease (CVD). The Framingham Heart Study (FHS) is a multi-generational observational study following participants over decades to identify risk factors for CVD by correlating genetic and phenotypic factors with clinical outcomes. As a large-scale population-based cohort with extensive clinical phenotyping, FHS provides a rich landscape to explore the relationships between the gut microbiome and cardiometabolic traits.

METHODS

We performed 16S rRNA gene sequencing on stool from 1423 participants of the FHS Generation 3, OMNI2, and New Offspring Spouse cohorts. Data processing and taxonomic assignment were performed with the 16S bioBakery workflow using the UPARSE pipeline. We conducted statistical analyses to investigate trends in overall microbiome composition and diversity in relation to disease states and systematically examined taxonomic associations with a variety of clinical traits, disease phenotypes, clinical blood markers, and medications.

RESULTS

We demonstrate that overall microbial diversity decreases with increasing 10-year CVD risk and body mass index measures. We link lifestyle factors, especially diet and exercise, to microbial diversity. Our association analyses reveal both known and unreported microbial associations with CVD and diabetes, related prescription medications, as well as many anthropometric and blood test measurements. In particular, we observe a set of microbial species that demonstrate significant associations with CVD risk, metabolic syndrome, and type 2 diabetes as well as a number of shared associations between microbial species and cardiometabolic subphenotypes.

CONCLUSIONS

The identification of significant microbial taxa associated with prevalent CVD and diabetes, as well as risk for developing CVD, adds to increasing evidence that the microbiome may contribute to CVD pathogenesis. Our findings support new hypothesis generation around shared microbe-mediated mechanisms that influence metabolic syndrome, diabetes, and CVD risk. Further investigation of the gut microbiomes of CVD patients in a targeted manner may elucidate microbial mechanisms with diagnostic and therapeutic implications.

Permanent Medical Grounding in Royal Canadian Air Force Pilots (20082017)

BACKGROUND: The aim of this retrospective registry study was to review the medical causes of RCAF pilot permanent grounding during the period 20082017 and to compare our findings to the previous study of 19781987 to determine if disease patterns had changed.METHODS: Material was obtained from the RCAF 1 Canadian Air Division Surgeons' medical registry of military pilots. Anonymized data for permanently grounded pilots were classified by medical diagnosis, age, and training status.RESULTS: During the period 20082017, there were a total of 162 pilots permanently grounded, of which 110 were trained and 52 untrained.DISCUSSION: In comparison to the 1991 study, there has been a decrease in permanent groundings due cardiovascular disease, but an increase due to mental health conditions, musculoskeletal issues, and motion sickness.Haworth D, Gray G, Zoltenko R, Bashirzadeh AJ. Permanent medical grounding in Royal Canadian Air Force pilots (20082017). Aerosp Med Hum Perform. 2021; 92(11): 913-918.

Matrix metalloproteinase-2 on activated platelets triggers endothelial PAR-1 initiating atherosclerosis

AIMS 

Platelets participate in atherogenesis with mechanisms not yet fully clarified. Vascular wall MMP-2 is involved in the arterial remodelling accompanying atherosclerosis. Platelets contain and release MMP-2 but no informations are available on its role in atherosclerotic lesion formation.

METHODS AND RESULTS 

We generated double knockout mice lacking the LDL receptor and MMP-2 only in circulating blood cells showing that they develop significantly lesser femoral intima thickening after photochemical-induced arterial damage and atherosclerotic lesions in the aorta, measured by the en face method, after 4 months of atherogenic diet. Moreover, repeated transfusions of autologous-activated platelets in LDLR-/- mice on atherogenic diet significantly enhanced the extension of aortic atherosclerotic lesions while transfusion of activated platelets from MMP-2-/- mice did not. In vitro coincubation studies showed that platelet-derived MMP-2 plays a pivotal role in the development and progression of atherosclerosis through a complex cross-talk between activated platelets, monocyte/macrophages, and endothelial cells. Translational studies in patients with CAD and chronic HIV infection showed that platelet surface expression of MMP-2 highly significantly correlated with the degree of carotid artery stenosis.

CONCLUSION 

We show a previously unknown mechanism of the pathway through which platelets expressing MMP-2 trigger the initial phases of atherosclerosis and provide a mechanism showing that they activate endothelial PAR-1 triggering endothelial p38MAPK signalling and the expression of adhesion molecules. The development of drugs blocking selectively platelet MMP-2 or its expression may represent a new approach to the prevention of atherosclerosis.

Salidroside Ameliorated Intermittent Hypoxia-Aggravated Endothelial Barrier Disruption and Atherosclerosis via the cAMP/PKA/RhoA Signaling Pathway

Background: Endothelial barrier dysfunction plays a key role in atherosclerosis progression. The primary pathology of obstructive sleep apnea-hypopnea syndrome is chronic intermittent hypoxia (IH), which induces reactive oxygen species (ROS) overproduction, endothelial barrier injury, and atherosclerosis. Salidroside, a typical pharmacological constituent of Rhodiola genus, has documented antioxidative, and cardiovascular protective effects. However, whether salidroside can improve IH-aggravated endothelial barrier dysfunction and atherosclerosis has not been elucidated.

Methods and results: In normal chow diet-fed ApoE^−/− mice, salidroside (100 mg/kg/d, p. o.) significantly ameliorated the formation of atherosclerotic lesions and barrier injury aggravated by 7-weeks IH (21%–5%–21%, 120 s/cycle). In human umbilical vein endothelial cells (HUVECs), exposure to IH (21%–5%–21%, 40 min/cycle, 72 cycles) decreased transendothelial electrical resistance and protein expression of vascular endothelial cadherin (VE-cadherin) and zonula occludens 1. In addition, IH promoted ROS production and activated ras homolog gene family member A (RhoA)/Rho-associated protein kinase (ROCK) pathway. All of these effects of IH were reversed by salidroside. Similar to salidroside, ROCK-selective inhibitors Y26732, and Fasudil protected HUVECs from IH-induced ROS overproduction and endothelial barrier disruption. Furthermore, salidroside increased intracellular cAMP levels, while the PKA-selective inhibitor H-89 attenuated the effects of salidroside on IH-induced RhoA/ROCK suppression, ROS scavenging, and barrier protection.

Conclusion: Our findings demonstrate that salidroside effectively ameliorated IH-aggravated endothelial barrier injury and atherosclerosis, largely through the cAMP/PKA/RhoA signaling pathway.