Endothelial damage effects of circulating microparticles from patients with stable angina are reduced by aspirin through ERK/p38 MAPKs pathways

Extracellular Vesicles in Atherosclerosis: State of the Art

Atherosclerosis is a chronic inflammatory disease driven by lipid accumulation in the arteries, leading to narrowing and thrombosis that causes mortality. Emerging evidence has confirmed that atherosclerosis affects younger people and is involved in the majority of deaths worldwide. EVs are associated with critical steps in atherosclerosis, cholesterol metabolism, immune response, endothelial dysfunction, vascular inflammation, and remodeling. Endothelial cell-derived EVs can interact with platelets and monocytes, thereby influencing endothelial dysfunction, atherosclerotic plaque destabilization, and the formation of thrombus. EVs are potential diagnostic and prognostic biomarkers in atherosclerosis (AS) and cardiovascular disease (CVD). Importantly, EVs derived from stem/progenitor cells are essential mediators of cardiogenesis and cardioprotection and may be used in regenerative medicine and tissue engineering.

Effect of Thrombolysis on Circulating Microparticles in Patients with ST-Segment Elevation Myocardial Infarction

Objective

We demonstrated that circulating microparticles (MPs) are increased in patients with coronary heart disease (both chronic coronary syndrome (CCS) and acute coronary syndrome). Whether thrombolysis affects MPs in patients with ST-segment elevation myocardial infarction (STEMI) with or without percutaneous coronary intervention (PCI) is unknown.

Methods

This study was divided into three groups: STEMI patients with thrombolysis (n = 18) were group T, patients with chronic coronary syndrome (n = 20) were group CCS, and healthy volunteers (n = 20) were the control group. Fasting venous blood was extracted from patients in the CCS and control groups, and venous blood was extracted from patients in the T group before (pre-T) and 2 hours after (post-T) thrombolysis. MPs from each group were obtained by centrifugation. After determining the concentration, the effects of MPs on endothelial nitric oxide synthase (eNOS) and inducible nitric oxide synthase (iNOS) in rat myocardial tissue in vitro were detected by immunohistochemistry and western blotting. Changes in nitric oxide (NO) and oxygen free radicals (O2•-) were also detected. The effect of MPs on vasodilation in isolated rat thoracic aortae was detected.

Results

Compared with that in the control group (2.60 ± 0.38 mg/ml), the concentration of MPs was increased in patients with CCS (3.49 ± 0.72 mg/ml) and in STEMI patients before thrombolysis (4.17 ± 0.58 mg/ml). However, thrombolysis did not further increase MP levels (post-T, 4.23 ± 1.01 mg/ml) compared with those in STEMI patients before thrombolysis. Compared with those in the control group, MPs in both CCS and STEMI patients before thrombolysis inhibited the expression of eNOS (both immunohistochemistry and western blot analysis of phosphorylation at Ser1177), NO production in the isolated myocardium and vasodilation in vitro and stimulated the expression of iNOS (immunohistochemistry and western blot analysis of phosphorylation at Thr495), and the generation of O2•- in the isolated myocardium. The effects of MPs were further enhanced by MPs from STEMI patients 2 hours after thrombolysis.

Conclusion

Changes in MP function after thrombolysis may be one of the mechanisms leading to ischemia-reperfusion after thrombolysis.

Antioxidant Properties of Oral Antithrombotic Therapies in Atherosclerotic Disease and Atrial Fibrillation

The thrombosis-related diseases are one of the leading causes of illness and death in the general population, and despite significant improvements in long-term survival due to remarkable advances in pharmacologic therapy, they continue to pose a tremendous burden on healthcare systems. The oxidative stress plays a role of pivotal importance in thrombosis pathophysiology. The anticoagulant and antiplatelet drugs commonly used in the management of thrombosis-related diseases show several pleiotropic effects, beyond the antithrombotic effects. The present review aims to describe the current evidence about the antioxidant effects of the oral antithrombotic therapies in patients with atherosclerotic disease and atrial fibrillation.

Kinetics of Circulating Extracellular Vesicles Over the 24-Hour Dosing Interval After Low-Dose Aspirin Administration in Patients at Cardiovascular Risk

Extracellular vesicles (EVs) are small vesicles deriving from all cell types during cell activation, involved in transcellular communication, and regarded as predictors of vascular damage and of cardiovascular events. We tested the hypothesis that, in patients on chronic low-dose aspirin treatment for cardiovascular prevention, aspirin may affect the release of EVs within the 24-hour interval. We enrolled 84 patients, mostly at high or very high cardiovascular risk, on chronic low-dose aspirin treatment. The numbers of circulating EVs (cEVs) and annexinV+ cEVs (total, platelet-derived, endothelial-derived, and leucocyte-derived) were assessed immediately before, and after 10 and 24 hours of a witnessed aspirin administration. Platelet cyclooxygenase 1 (COX-1) recovery was characterized by measuring serum thromboxane B₂ (sTXB₂ ) at the same timepoints. Nine healthy participants were also enrolled. In patients, daily aspirin administration acutely inhibited after 10 hours following aspirin administrations the release of cEVs (total and leukocyte-derived) and annexinV+ cEVs (total, platelet-derived, endothelial-derived, and leukocyte-derived), with a rapid recovery at 24 hours. The inhibition after 10 hours suggests a COX-1-dependent mechanism. Interestingly, the slope of platelet-derived and of annexinV+ platelet-derived cEVs were both directly related to sTXB₂ slope and COX-1 messenger RNA, raising the hypothesis that vice versa, cEVs may affect the rate of COX-1 recovery and the subsequent duration of aspirin effect. In healthy participants, no circadian difference was observed, except for leukocyte-derived cEVs. Our findings suggest a previously unappreciated effect of aspirin on the kinetics of a subset of cEVs possibly contributing to the cardioprotective effects of this drug.

Deposition of platelet-derived microparticles in podocytes contributes to diabetic nephropathy

BACKGROUND

Diabetic nephropathy (DN) is the leading cause of end-stage renal disease in the developed world. Podocyte injury is a critical cellular event involved in the progression of DN. Our previous studies demonstrated that platelet-derived microparticles (PMPs) mediated endothelial injury in diabetic rats. This study aimed to investigate whether PMPs are deposited in podocytes and to assess their potential effects on podocyte injury in DN.

METHODS

The deposition of PMPs in podocytes was assessed by immunofluorescent staining and electron microscopy. The changes in renal pathology and ultra-microstructure were assessed by periodic acid-Schiff staining and electron microscopy, respectively. The expression of inflammatory cytokines and extracellular matrix proteins was measured by immuno-histochemical staining and western blot.

RESULTS

PMPs were widely deposited in podocytes of glomeruli in diabetic patients and animal models and closely associated with DN progression. Interestingly, aspirin treatment significantly inhibited the accumulation of PMPs in the glomeruli of diabetic rats, alleviated mesangial matrix expansion and fusion of foot processes, and decreased the protein expression of inflammatory cytokines and extracellular matrix secretion. An in vitro study further confirmed the deposition of PMPs in podocytes. Moreover, PMP stimulation induced the phenotypic transition of podocytes through decreased podocin protein expression and increased protein expression of α-SMA and fibronectin, which was correlated with increased production of inflammatory cytokines.

CONCLUSION

Our findings demonstrated for the first time that the deposition of PMPs in podocytes contributed to the development of DN.

Extracellular Vesicles as Drivers of Immunoinflammation in Atherothrombosis

Atherosclerotic cardiovascular disease is the leading cause of morbidity and mortality all over the world. Extracellular vesicles (EVs), small lipid-bilayer membrane vesicles released by most cellular types, exert pivotal and multifaceted roles in physiology and disease. Emerging evidence emphasizes the importance of EVs in intercellular communication processes with key effects on cell survival, endothelial homeostasis, inflammation, neoangiogenesis, and thrombosis. This review focuses on EVs as effective signaling molecules able to both derail vascular homeostasis and induce vascular dysfunction, inflammation, plaque progression, and thrombus formation as well as drive anti-inflammation, vascular repair, and atheroprotection. We provide a comprehensive and updated summary of the role of EVs in the development or regression of atherosclerotic lesions, highlighting the link between thrombosis and inflammation. Importantly, we also critically describe their potential clinical use as disease biomarkers or therapeutic agents in atherothrombosis.

Different Contribution of Monocyte- and Platelet-Derived Microvesicles to Endothelial Behavior

Several contributions of circulating microvesicles (MVs) to the endothelial dysfunction have been reported in the past; a head-to-head comparison of platelet- and monocyte–derived MVs has however never been performed. To this aim, we assessed the involvement of these MVs in vessel damage related processes, i.e., oxidative stress, inflammation, and leukocyte-endothelial adhesion. Platelets and monocytes isolated from healthy subjects (HS, n = 15) were stimulated with TRAP-6 and LPS to release MVs that were added to human vascular endothelial cell (hECV) culture to evaluate superoxide anion production, inflammatory markers (IL-6, TNFα, NF-κB mRNA expression), and hECV adhesiveness. The effects of the MVs-induced from HS were compared to those induced by MVs spontaneously released from cells of patients with ST-segment elevation myocardial infarction (STEMI, n = 7). MVs released by HS-activated cells triggered a threefold increase in oxidative burst in a concentration-dependent manner. Only MVs released from monocytes doubled IL-6, TNFα, and NF-κB mRNA expression and monocyte-endothelial adhesion. Interestingly, the effects of the MVs isolated from STEMI-monocytes were not superimposable to previous ones except for adhesion to hECV. Conversely, MVs released from STEMI-platelets sustained both redox state and inflammatory phenotype. These data provide evidence that MVs released from activated and/or pathologic platelets and monocytes differently affect endothelial behavior, highlighting platelet-MVs as causative factors of impaired endothelial function in the acute phase of STEMI.

Antiplatelet drugs and liver fibrosis

Liver fibrosis results from an imbalance between extracellular matrix formation and degradation. The background of liver fibrosis is chronic inflammation and subsequent microcirculation disturbance including microthrombosis. Platelets actively participate in liver fibrosis not only as a part of the clotting system but also by releasing granules containing important mediators. In fact, platelets may play a dual role in the pathophysiology of liver fibrosis as they are able to stimulate regeneration as well as aggravate the destruction of the liver. Recent studies revealed that antiplatelet therapy correlates with inhibition of liver fibrosis. However, liver impairment is associated with extensive coagulation disorders thus the safety of antiplatelet therapy is an area for detailed exploration. In this review, the role of platelets in liver fibrosis and accompanying hemostatic disorders are discussed. Additionally, results of animal and human studies on antiplatelet drugs in liver disorders and their potential therapeutic utility are presented.

The Material Basis and Mechanism of Xuefu Zhuyu Decoction in Treating Stable Angina Pectoris and Unstable Angina Pectoris

METHODS

Firstly, we used a network proximity approach to calculate and compare the effectiveness of the formula with that of Western drugs for each type of angina, including all targets and intersecting targets, from a topological perspective. Secondly, we compared the mechanisms of action of the two angina pectoris at three levels and five aspects, including conventional and modular analysis approaches. Thirdly, based on the unique functions of each angina in the complex heterogeneous network, we designed a reverse process for finding the material basis using dynamic, static, and enriched items as well as a total item. Finally, the designed inverse process, material basis, and mechanism of action were validated.

RESULTS

The target network of Xuefu Zhuyu decoction is closer to the target network of each type of angina than that of Western drugs, and the intersection targets have a closer proximity. Comparison of the mechanisms of action showed that stable angina and unstable angina had 158 common targets, while the unique targets were 34 and 1, respectively. Modularity analysis showed that the GO similarity of target modules was highly correlated with KEGG similarity. We ended up with 67 compounds upregulated for stable angina and 47 compounds upregulated for unstable angina. Our results were validated by literature mining, high-volume molecular docking, and miRNA enrichment analysis.

CONCLUSIONS

For both types of angina pectoris, Xuefu Zhuyu decoction is superior to Western drugs. A comparison of various aspects led to the unique mechanisms of action, from which the material basis of each type of angina was deduced.

Aspirin Actions in Treatment of NSAID-Exacerbated Respiratory Disease

Non-steroidal Anti-inflammatory drugs (NSAID)-exacerbated respiratory disease (N-ERD) is characterized by nasal polyposis, chronic rhinosinusitis, adult-onset asthma and hypersensitive reactions to cyclooxygenase-1 (COX-1) inhibitors. Among the available treatments for this disease, a combination of endoscopic sinus surgery followed by aspirin desensitization and aspirin maintenance therapy has been an effective approach. Studies have shown that long-term aspirin maintenance therapy can reduce the rate of nasal polyp recurrence in patients with N-ERD. However, the exact mechanism by which aspirin can both trigger and suppress airway disease in N-ERD remains poorly understood. In this review, we summarize current knowledge of aspirin effects in N-ERD, cardiovascular disease, and cancer, and consider potential mechanistic pathways accounting for the effects of aspirin in N-ERD.

Vascular damage effect of circulating microparticles in patients with ACS is aggravated by type 2 diabetes

As a common factor of both type 2 diabetes mellitus (T2DM) and acute coronary syndrome (ACS), circulating microparticles (MPs) may provide a link between these two diseases. The present study compared the content and function of MPs from patients with ACS with or without T2DM. MPs from healthy subjects (n=20), patients with ACS (n=24), patients with T2DM (n=20) and patients with combined ACS and T2DM (n=24) were obtained. After incubating rat thoracic tissue with MPs, the effect of MPs on endothelial‑dependent vasodilatation, expression of caveolin‑1 and endothelial nitric oxide synthase (eNOS), phosphorylation of eNOS at the S1177 and T495 sites and its association with heat shock protein 90 (Hsp90), and the generation of NO and superoxide anion (O_2˙‑) were determined. MP concentrations were higher in patients with T2DM and patients with ACS with or without T2DM than in healthy subjects. Moreover, MPs from patients with T2DM or ACS led to impairment in endothelial‑dependent vasodilatation, decreased expression of NO, as well as eNOS and its phosphorylation at Ser1177 and association with Hsp90, but increased eNOS phosphorylation at T495, caveolin‑1 expression and O_2˙‑ generation. These effects were strengthened by MPs from patients with ACS combined with T2DM. T2DM not only increased MP content but also resulted in greater vascular impairment effects in ACS. These results may provide novel insight into the treatment of patients with ACS and T2DM.

Platelet-Derived Extracellular Vesicles as Target of Antiplatelet Agents. What Is the Evidence?

Platelet-derived large extracellular vesicles (often referred to as microparticles in the field of cardiovascular disease) have been identified as effector in the atherothrombotic process, therefore representing a target of pharmacological intervention of potential interest. Despite that, limited evidence is so far available concerning the effects of antiplatelet agents on the release of platelet-derived extracellular vesicles. In the present narrative review, the mechanisms leading to vesiculation in platelets and the pathophysiological processes implicated will be discussed. This will be followed by a summary of the present evidence concerning the effects of antiplatelet agents under experimental conditions and in clinical settings.

The role of microvesicles and its active molecules in regulating cellular biology

Cell‐derived microvesicles are membrane vesicles produced by the outward budding of the plasma membrane and released by almost all types of cells. These have been considered as another mechanism of intercellular communication, because they carry active molecules, such as proteins, lipids and nucleic acids. Furthermore, these are present in circulating fluids, such as blood and urine, and are closely correlated to the progression of pathophysiological conditions in many diseases. Recent studies have revealed that microvesicles have a dual effect of damage and protection of receptor cells. However, the nature of the active molecules involved in this effect remains unclear. The present study mainly emphasized the mechanism of microvesicles and the active molecules mediating the different biological effects of receptor cells by affecting autophagy, apoptosis and inflammation pathways. The effective ways of blocking microvesicles and its active molecules in mediating cell damage when microvesicles exert harmful effects were also discussed.