Ticagrelor induces paraoxonase-1 (PON1) and better protects hypercholesterolemic mice against atherosclerosis compared to clopidogrel

Modulation of the antioxidant enzyme paraoxonase-1 for protection against cardiovascular diseases

AIM

The enzyme paraoxonase 1 (PON1) bound to high-density lipoprotein has received special attention for its protective role against stress-mediated damage and use as a potential regulatory target in atherosclerosis and related vascular diseases.

DATA SYNTHESIS

We present an overview of the literature on PON1 activity and mRNA levels by investigating its modulation for clinical translations. Specifically, the expression of PON1 and its regulated activity can be modified in different ways with natural substances, drugs, and lifestyle factors thar affect the development of atherosclerosis.

CONCLUSIONS

The endothelial contribution of PON1 to overcome differences considering an individual's disease development risk is supported by polymorphism interaction data and the susceptibility to modify PON1 responses in chronic events composed by biological and environmental factors.

A Comprehensive Review of the Pleiotropic Effects of Ticagrelor

AIMS

This review summarizes the findings of preclinical studies evaluating the pleiotropic effects of ticagrelor. These include attenuation of ischemia-reperfusion injury (IRI), inflammation, adverse cardiac remodeling, and atherosclerosis. In doing so, it aims to provide novel insights into ticagrelor's mechanisms and benefits over other P2Y12 inhibitors. It also generates viable hypotheses for the results of seminal clinical trials assessing ticagrelor use in acute and chronic coronary syndromes.

METHODS AND RESULTS

A comprehensive review of the preclinical literature demonstrates that ticagrelor protects against IRI in the setting of both an acute myocardial infarction (MI), and when MI occurs while on chronic treatment. Maintenance therapy with ticagrelor also likely mitigates adverse inflammation, cardiac remodeling, and atherosclerosis, while improving stem cell recruitment. These effects are probably mediated by ticagrelor's ability to increase local interstitial adenosine levels which activate downstream cardio-protective molecules. Attenuation and augmentation of these pleiotropic effects by high-dose aspirin and caffeine, and statins respectively may help explain variable outcomes in PLATO and subsequent randomized controlled trials (RCTs).

CONCLUSION

Most RCTs and meta-analyses have not evaluated the pleiotropic effects of ticagrelor. We need further studies comparing cardiovascular outcomes in patients treated with ticagrelor versus other P2Y12 inhibitors that are mindful of the unique pleiotropic advantages afforded by ticagrelor, as well as possible interactions with other therapies (e.g., aspirin, statins, caffeine).

The Regulatory Variant -108C/T in the Promoter of Paraoxonase 1 (PON1) Gene has a More Important Role in Regulating PON1 Activity Compared to rs3735590 in 3'-UTR in Patients with Coronary Artery Disease

Background

This study aimed to assess the serum activity of paraoxonase 1 (PON1) in patients with coronary artery disease (CAD) based on two genetic variants including the -108C/T variant in the promoter region and the rs3735590 variant in the binding site of miR-616 at the 3'-UTR of the PON1 gene.

Materials and Methods

A total of 140 subjects who exhibited clinical symptoms of CAD underwent diagnostic coronary angiography. The patients with CAD were further categorized into two groups: single-vessel disease (SVD) and multi-vessel disease (MVD). The study variants were genotyped using the restriction fragment length polymorphism (RFLP) technique after polymerase chain reaction amplification.

Results

After adjusting for age, gender, body mass index, metformin, and statin usage, a significant association was observed between the -108C/T variant and PON1 activity (P < 0.001). In the sub-groups of both SVD and MVD, individuals with the TC+CC genotypes exhibited significantly higher PON1 activity compared to TT homozygotes (P = 0.001 for SVD and P = 0.01 for MVD). As for the rs3735590 variant, individuals with the A allele (GA+AA genotypes) had higher PON1 activity compared to those with the GG genotype in both the SVD and MVD groups, although the results did not reach statistical significance.

Conclusions

Our study findings indicate a significant decrease in PON1 activity among patients with obstructive CAD. Notably, our results suggest that the -108C/T variant exerts a greater influence on PON1 activity compared to the rs3735590 variant. These findings highlight the crucial role of the -108C/T variant in modulating PON1 activity within the context of atherosclerosis.

Ticagrelor, but Not Clopidogrel, Attenuates Hepatic Steatosis in a Model of Metabolic Dysfunction-Associated Steatotic Liver Disease

BACKGROUND

Previous studies have suggested that platelets are associated with inflammation and steatosis and may play an important role in liver health. Therefore, we evaluated whether antiplatelet agents can improve metabolic disorder-related fatty liver disease (MASLD).

METHODS

The mice used in the study were fed a high-fat-diet (HFD) and were stratified through liver biopsy at 18 weeks. A total of 22 mice with NAFLD activity scores (NAS) ≥ 4 were randomly divided into three groups (HFD-only, clopidogrel (CLO; 35 mg/kg/day), ticagrelor (TIC; 40 mg/kg/day) group). And then, they were fed a feed mixed with the respective drug for 15 weeks. Blood and tissue samples were collected and used in the study.

RESULTS

The TIC group showed a significantly lower degree of NAS and steatosis than the HFD group (p = 0.0047), but no effect on the CLO group was observed. Hepatic lipogenesis markers' (SREBP1c, FAS, SCD1, and DGAT2) expression and endoplasmic reticulum (ER) stress markers (CHOP, Xbp1, and GRP78) only reduced significantly in the TIC treatment group. Inflammation genes (MCP1 and TNF-α) also decreased significantly in the TIC group, but not in the CLO group. Nile red staining intensity and hepatic lipogenesis markers were reduced significantly in HepG2 cells following TIC treatment.

CONCLUSION

Ticagrelor attenuated NAS and hepatic steatosis in a MASLD mice model by attenuating lipogenesis and inflammation, but not in the CLO group.

The Role of Polyphenols in Modulating PON1 Activity Regarding Endothelial Dysfunction and Atherosclerosis

The incidence and prevalence of cardiovascular diseases are still rising. The principal mechanism that drives them is atherosclerosis, an affection given by dyslipidemia and a pro-inflammatory state. Paraoxonase enzymes have a protective role due to their ability to contribute to antioxidant and anti-inflammatory pathways, especially paraoxonase 1 (PON1). PON1 binds with HDL (high-density lipoprotein), and high serum levels lead to a protective state against dyslipidemia, cardiovascular diseases, diabetes, stroke, nonalcoholic fatty liver disease, and many others. Modulating PON1 expression might be a treatment objective with significant results in limiting the prevalence of atherosclerosis. Lifestyle including diet and exercise can raise its levels, and some beneficial plants have been found to influence PON1 levels; therefore, more studies on herbal components are needed. Our purpose is to highlight the principal roles of Praoxonase 1, its implications in dyslipidemia, cardiovascular diseases, stroke, and other diseases, and to emphasize plants that can modulate PON1 expression, targeting the potential of some flavonoids that could be introduced as supplements in our diet and to validate the hypothesis that flavonoids have any effects regarding PON1 function.

Computational drug repositioning of clopidogrel as a novel therapeutic option for focal segmental glomerulosclerosis

Focal segmental glomerulosclerosis (FSGS) is a glomerular lesion often associated with nephrotic syndrome. It is also associated with a high risk of progression to end-stage kidney disease. Current treatment of FSGS is limited to systemic corticosteroids or calcineurin inhibition, along with inhibitors of the renin-angiotensin-aldosterone system. FSGS is heterogeneous in etiology, and novel therapies targeting specific, dysregulated molecular pathways represent a major unmet medical need. We have generated a network-based molecular model of FSGS pathophysiology using previously established systems biology workflows to allow computational evaluation of compounds for their predicted interference with molecular processes contributing to FSGS. We identified the anti-platelet drug clopidogrel as a therapeutic option to counterbalance dysregulated FSGS pathways. This prediction of our computational screen was validated by testing clopidogrel in the adriamycin FSGS mouse model. Clopidogrel improved key FSGS outcome parameters and significantly reduced urinary albumin to creatinine ratio (p<0.01) and weight loss (p<0.01), and ameliorated histopathological damage (p<0.05). Clopidogrel is used to treat several cardiovascular diseases linked to chronic kidney disease. Clopidogrel's favorable safety profile and its efficacy in the adriamycin mouse FSGS model thus recommend it as an attractive drug repositioning candidate for clinical trial in FSGS.

Changes in lipoproteins associated with lipid-lowering and antiplatelet strategies in patients with acute myocardial infarction

Background

Despite lipid-lowering and antiplatelet therapy, the pattern of residual lipoproteins seems relevant to long-term cardiovascular outcomes. This study aims to evaluate the effects of combined therapies, commonly used in subjects with acute myocardial infarction, in the quality of low-density lipoprotein (LDL) particles.

Methods

Prospective, open-label trial, included patients with acute myocardial infarction. Patients were randomized to antiplatelet treatment (ticagrelor or clopidogrel) and subsequently to lipid-lowering therapy (rosuvastatin or simvastatin/ezetimibe) and were followed up for six months. Nonlinear optical properties of LDL samples were examined by Gaussian laser beam (Z-scan) to verify the oxidative state of these lipoproteins, small angle X-ray scattering (SAXS) to analyze structural changes on these particles, dynamic light scattering (DLS) to estimate the particle size distribution, ultra violet (UV)-visible spectroscopy to evaluate the absorbance at wavelength 484 nm (typical from carotenoids), and polyacrylamide gel electrophoresis (Lipoprint) to analyze the LDL subfractions.

Results

Simvastatin/ezetimibe with either clopidogrel or ticagrelor was associated with less oxidized LDL, and simvastatin/ezetimibe with ticagrelor to lower cholesterol content in the atherogenic subfractions of LDL, while rosuvastatin with ticagrelor was the only combination associated with increase in LDL size.

Conclusions

The quality of LDL particles was influenced by the antiplatelet/lipid-lowering strategy, with ticagrelor being associated with the best performance with both lipid-lowering therapies. Trial registration: NCT02428374.

Pleiotropic Effects of Ticagrelor: Influence on CYP4F2 Gene and Protein Expression in HUVEC and HepG2, and Escherichia coli Bacterial Survival

Background

Antiplatelet drugs, such as ticagrelor, which target platelet P2Y₁₂ receptors, are used for prevention of ischemic heart disease. Ticagrelor is also known to have pleiotropic effects of unknown mechanisms. Ticagrelor could influence the expression of molecules involved in resolution of inflammation. This study aimed to investigate if ticagrelor could change the expression of CYP4F2 and its encoded protein concentration and, additionally, to determine ticagrelor possible antibacterial activity against gram-negative bacteria.

Methods

CYP4F2 expression was determined in HUVEC and HepG2 cell lines by qPCR. CYP4F2 protein concentration was determined by ELISA. Antibiotic susceptibility testing was performed using a disc diffusion method.

Results

Ticagrelor was observed to reduce the expression of CYP4F2 in HUVEC and HepG2 cell lines. It also reduced CYP4F2 protein levels in HUVEC cells. Ticagrelor had no bactericidal activity against gram-negative third generation cephalosporin resistant E. coli.

Conclusion

Ticagrelor reduced CYP4F2 protein concentration in HUVEC, and CYP4F2 expression in HUVEC and HepG2 cells, but had no effect on third-generation cephalosporin-resistant E. coli strains.

Pleiotropic effects of clopidogrel

Clopidogrel is a widely prescribed prodrug with anti-thrombotic activity through irreversible inhibition of the P2Y₁₂ receptor on platelets. It is FDA-approved for the clinical management of thrombotic diseases like unstable angina, myocardial infarction, stroke, and during percutaneous coronary interventions. Hepatic clopidogrel metabolism generates several distinct metabolites. Only one of these metabolites is responsible for inhibiting the platelet P2Y₁₂ receptor. Importantly, various non-hemostatic effects of clopidogrel therapy have been described. These non-hemostatic effects are perhaps unsurprising, as P2Y₁₂ receptor expression has been reported in multiple tissues, including osteoblasts, leukocytes, as well as vascular endothelium and smooth muscle. While the "inactive" metabolites have been commonly thought to be biologically inert, recent findings have uncovered P2Y₁₂ receptor-independent effects of clopidogrel treatment that may be mediated by understudied metabolites. In this review, we summarize both the P2Y₁₂ receptor-mediated and non-P2Y₁₂ receptor-mediated effects of clopidogrel and its metabolites in various tissues.

Ticagrelor alleviates high-carbohydrate intake induced altered electrical activity of ventricular cardiomyocytes by regulating sarcoplasmic reticulum-mitochondria miscommunication

Metabolic syndrome (MetS) is associated with additional cardiovascular risk in mammalians while there are relationships between hyperglycemia-associated cardiovascular dysfunction and increased platelet P2Y12 receptor activation. Although P2Y12 receptor antagonist ticagrelor (Tica) plays roles in reduction of cardiovascular events, its beneficial mechanism remains poorly understood. Therefore, we aimed to clarify whether Tica can exert a direct protective effect in ventricular cardiomyocytes from high-carbohydrate diet-induced MetS rats, at least, through affecting sarcoplasmic reticulum (SR)-mitochondria (Mit) miscommunication. Tica treatment of MetS rats (150 mg/kg/day for 15 days) significantly reversed the altered parameters of action potentials by reversing sarcolemmal ionic currents carried by voltage-dependent Na+ and K+ channels, and Na+/Ca2+-exchanger in the cells, expressed P2Y12 receptors. The increased basal-cytosolic Ca2+ level and depressed SR Ca2+ load were also reversed in Tica-treated cells, at most, though recoveries in the phosphorylation levels of ryanodine receptors and phospholamban. Moreover, there were marked recoveries in Mit structure and function (including increases in both autophagosomes and fragmentations) together with recoveries in Mit proteins and the factors associated with Ca2+ transfer between SR-Mit. There were further significant recoveries in markers of both ER stress and oxidative stress. Taken into consideration the Tica-induced prevention of ER stress and mitochondrial dysfunction, our data provided an important document on the pleiotropic effects of Tica in the electrical activity of the cardiomyocytes from MetS rats. This protective effect seems through recoveries in SR-Mit miscommunication besides modulation of different sarcolemmal ion-channel activities, independent of P2Y12 receptor antagonism.

Extracellular Adenosine Diphosphate Stimulates CXCL10-Mediated Mast Cell Infiltration Through P2Y1 Receptor to Aggravate Airway Inflammation in Asthmatic Mice

Asthma is an inflammatory disease associated with variable airflow obstruction and airway inflammation. This study aimed to explore the role and mechanism of extracellular adenosine diphosphate (ADP) in the occurrence of airway inflammation in asthma. The expression of ADP in broncho-alveolar lavage fluid (BALF) of asthmatic patients was determined by enzyme linked immunosorbent assay (ELISA) and the expression of P2Y1 receptor in lung tissues was determined by reverse transcription-quantitative polymerase chain reaction. Asthmatic mouse model was induced using ovalbumin and the mice were treated with ADP to assess its effects on the airway inflammation and infiltration of mast cells (MCs). Additionally, alveolar epithelial cells were stimulated with ADP, and the levels of interleukin-13 (IL-13) and C-X-C motif chemokine ligand 10 (CXCL10) were measured by ELISA. We finally analyzed involvement of NF-κB signaling pathway in the release of CXCL10 in ADP-stimulated alveolar epithelial cells. The extracellular ADP was enriched in BALF of asthmatic patients, and P2Y1 receptor is highly expressed in lung tissues of asthmatic patients. In the OVA-induced asthma model, extracellular ADP aggravated airway inflammation and induced MC infiltration. Furthermore, ADP stimulated alveolar epithelial cells to secrete chemokine CXCL10 by activating P2Y1 receptor, whereby promoting asthma airway inflammation. Additionally, ADP activated the NF-κB signaling pathway to promote CXCL10 release. As a “danger signal” extracellular ADP could trigger and maintain airway inflammation in asthma by activating P2Y1 receptor. This study highlights the extracellular ADP as a promising anti-inflammatory target for the treatment of asthma.

Dietary Avian Proteins Are Comparable to Soybean Proteins on the Atherosclerosis Development and Fatty Liver Disease in Apoe-Deficient Mice

Background and aim: The type and amount of dietary protein has become a topic of renewed interest in light of their involvement in metabolic diseases, atherosclerosis and thrombosis. However, little attention has been devoted to the effect of avian proteins despite their wide human consumption. The aim was to investigate the influence of chicken and turkey as sources of protein compared with that of soybean on atherosclerosis and fatty liver disease. Methods and results: To this purpose, male and female Apoe-deficient were fed purified Western diets differing in their protein sources for 12 weeks. After this period, blood, liver, aortic tree and heart base samples were taken for analyses of plasma lipids and atherosclerosis. Plasma triglycerides, non-esterified fatty acids, esterified cholesterol levels and radical oxygen species in lipoproteins changed depending on the diet and sex. Females consuming the turkey protein-containing diet showed decreased atherosclerotic foci, as evidenced by the en face atherosclerosis analyses. The presence of macrophages and smooth muscle cells in plaques were not modified, and no changes were observed in hepatic lipid droplets in the studied groups either. Paraoxonase activity was higher in the group consuming turkey protein without sex differences, but only in females, it was significantly associated with aortic lesion areas. Conclusions: Compared to soybean protein, the consumption of avian proteins depending on sex resulted in similar or lower atherosclerosis development and comparable hepatic steatosis.

The pleiotropic effects of antithrombotic drugs in the metabolic-cardiovascular-neurodegenerative disease continuum: impact beyond reduced clotting

Antithrombotic drugs are widely used for primary and secondary prevention, as well as treatment of many cardiovascular disorders. Over the past few decades, major advances in the pharmacology of these agents have been made with the introduction of new drug classes as novel therapeutic options. Accumulating evidence indicates that the beneficial outcomes of some of these antithrombotic agents are not solely related to their ability to reduce thrombosis. Here, we review the evidence supporting established and potential pleiotropic effects of four novel classes of antithrombotic drugs, adenosine diphosphate (ADP) P2Y12-receptor antagonists, Glycoprotein IIb/IIIa receptor Inhibitors, and Direct Oral Anticoagulants (DOACs), which include Direct Factor Xa (FXa) and Direct Thrombin Inhibitors. Specifically, we discuss the molecular evidence supporting such pleiotropic effects in the context of cardiovascular disease (CVD) including endothelial dysfunction (ED), atherosclerosis, cardiac injury, stroke, and arrhythmia. Importantly, we highlight the role of DOACs in mitigating metabolic dysfunction-associated cardiovascular derangements. We also postulate that DOACs modulate perivascular adipose tissue inflammation and thus, may reverse cardiovascular dysfunction early in the course of the metabolic syndrome. In this regard, we argue that some antithrombotic agents can reverse the neurovascular damage in Alzheimer's and Parkinson's brain and following traumatic brain injury (TBI). Overall, we attempt to provide an up-to-date comprehensive review of the less-recognized, beneficial molecular aspects of antithrombotic therapy beyond reduced thrombus formation. We also make a solid argument for the need of further mechanistic analysis of the pleiotropic effects of antithrombotic drugs in the future.

Purinergic Signaling in Controlling Macrophage and T Cell Functions During Atherosclerosis Development

Atherosclerosis is a hardening and narrowing of arteries causing a reduction of blood flow. It is a leading cause of death in industrialized countries as it causes heart attacks, strokes, and peripheral vascular disease. Pathogenesis of the atherosclerotic lesion (atheroma) relies on the accumulation of cholesterol-containing low-density lipoproteins (LDL) and on changes of artery endothelium that becomes adhesive for monocytes and lymphocytes. Immunomediated inflammatory response stimulated by lipoprotein oxidation, cytokine secretion and release of pro-inflammatory mediators, worsens the pathological context by amplifying tissue damage to the arterial lining and increasing flow-limiting stenosis. Formation of thrombi upon rupture of the endothelium and the fibrous cup may also occur, triggering thrombosis often threatening the patient’s life. Purinergic signaling, i.e., cell responses induced by stimulation of P2 and P1 membrane receptors for the extracellular nucleotides (ATP, ADP, UTP, and UDP) and nucleosides (adenosine), has been implicated in modulating the immunological response in atherosclerotic cardiovascular disease. In this review we will describe advancements in the understanding of purinergic modulation of the two main immune cells involved in atherogenesis, i.e., monocytes/macrophages and T lymphocytes, highlighting modulation of pro- and anti-atherosclerotic mediated responses of purinergic signaling in these cells and providing new insights to point out their potential clinical significance.