Role of platelets in the development of atherosclerosis

Mean platelet volume is associated with periodontitis: a cross-sectional study

BACKGROUND

It is uncertain if mean platelet volume and periodontitis are related. The objective of this study was to examine the association between levels of mean platelet volume and moderate/severe periodontitis in adult persons who inhabit the U.S.

METHODS

We screened 6,809 people from the National Health and Nutrition Examination Survey (NHANES 2009-2012). Mean platelet volume was measured in the Mobile Examination Centers (MECs) using the Beckman Coulter analyzer. The category of periodontitis was defined by the CDC/AAP using clinical periodontal parameters. Multiple logistic regression models were employed to examine the distribution for covariate differences across the various independent groups. Four models were employed to examine the relationship between mean platelet volume level and periodontitis. Smoothed curve fitting was utilized to confirm the linearity of the relationships. To determine the impact of factors on the connection between MPV and periodontitis, subgroup analysis and interaction testing were utilized.

RESULTS

Results from the multiple logistic regression analysis indicate a significant association between moderate/severe periodontitis and the mean platelet level, even after considering any potential confounding variables (OR = 1.090, 95% CI: 1.019-1.166, P-value = 0.01211). Additionally, those in the upper tertile of mean platelet volume levels had a 21.6% higher probability of developing periodontitis when compared with those in the least tertile of mean platelet levels (OR = 1.216, 95% CI:1.052-1.406, P-value = 0.00816). Moreover, it showed a positive correlation between mean platelet volume (MPV) and moderate/severe periodontitis. Subgroup analyses indicated a positive association between the level of mean platelet volume and moderate/severe periodontitis among individuals who were under 60 years of age, had low income, were obese, never smoked, were heavy drinkers, had hypertension, and had no cardiovascular disease (p < 0.05). However, none of the subgroups exhibited significant interactions (p for interaction > 0.05).

CONCLUSION

A correlation has been found between mean platelet volume levels and periodontal disease in individuals residing in the United States.

Targeted Delivery of Mesenchymal Stem Cell-Derived Bioinspired Exosome-Mimetic Nanovesicles with Platelet Membrane Fusion for Atherosclerotic Treatment

Purpose

Accumulating evidence indicates that mesenchymal stem cells (MSCs)-derived exosomes hold significant potential for the treatment of atherosclerosis. However, large-scale production and organ-specific targeting of exosomes are still challenges for further clinical applications. This study aims to explore the targeted efficiency and therapeutic potential of biomimetic platelet membrane-coated exosome-mimetic nanovesicles (P-ENVs) in atherosclerosis.

Methods

To produce exosome-mimetic nanovesicles (ENVs), MSCs were successively extruded through polycarbonate porous membranes. P-ENVs were engineered by fusing MSC-derived ENVs with platelet membranes and characterized using transmission electron microscopy (TEM), nanoparticle tracking analysis (NTA), and Western blot. The stability and safety of P-ENVs were also assessed. The targeted efficacy of P-ENVs was evaluated using an in vivo imaging system (IVIS) spectrum imaging system and immunofluorescence. Histological analyses, Oil Red O (ORO) staining, and Western blot were used to investigate the anti-atherosclerotic effectiveness of P-ENVs.

Results

Both ENVs and P-ENVs exhibited similar characteristics to exosomes. Subsequent miRNA sequencing of P-ENVs revealed their potential to mitigate atherosclerosis by influencing biological processes related to cholesterol metabolism. In an ApoE-/- mice model, the intravenous administration of P-ENVs exhibited enhanced targeting of atherosclerotic plaques, resulting in a significant reduction in lipid deposition and necrotic core area. Our in vitro experiments showed that P-ENVs promoted cholesterol efflux and reduced total cholesterol content in foam cells. Further analysis revealed that P-ENVs attenuated intracellular cholesterol accumulation by upregulating the expression of the critical cholesterol transporters ABCA1 and ABCG1.

Conclusion

This study highlighted the potential of P-ENVs as a novel nano-drug delivery platform for enhancing drug delivery efficiency while concurrently mitigating adverse reactions in atherosclerotic therapy.

Platelets, Protean Cells with All-Around Functions and Multifaceted Pharmacological Applications

Platelets, traditionally known for their roles in hemostasis and coagulation, are the most prevalent blood component after erythrocytes (150,000-400,000 platelets/μL in healthy humans). However, only 10,000 platelets/μL are needed for vessel wall repair and wound healing. Increased knowledge of the platelet's role in hemostasis has led to many advances in understanding that they are crucial mediators in many other physiological processes, such as innate and adaptive immunity. Due to their multiple functions, platelet dysfunction is involved not only in thrombosis, mediating myocardial infarction, stroke, and venous thromboembolism, but also in several other disorders, such as tumors, autoimmune diseases, and neurodegenerative diseases. On the other hand, thanks to their multiple functions, nowadays platelets are therapeutic targets in different pathologies, in addition to atherothrombotic diseases; they can be used as an innovative drug delivery system, and their derivatives, such as platelet lysates and platelet extracellular vesicles (pEVs), can be useful in regenerative medicine and many other fields. The protean role of platelets, from the name of Proteus, a Greek mythological divinity who could take on different shapes or aspects, is precisely the focus of this review.

Early reocclusion after successful mechanical thrombectomy for large artery occlusion-related stroke

BACKGROUND AND PURPOSE

Despite initial successful recanalization after mechanical thrombectomy (MT), some patients with large artery occlusion (LAO)-related stroke will experience an early reocclusion of the injured vessel which may worsen their prognosis. We aimed to investigate the prevalence, associated factors and prognosis of early reocclusion after successful MT in a large prospective cohort of stroke patients with LAO.

METHODS

We included patients from the Lille reperfusion registry with LAO-related stroke involving M1 segment, internal carotid artery terminus or tandem ICA-M1 occlusion, with successful recanalization after MT and available 24 h imaging follow-up. Early reocclusion was defined as internal carotid artery terminus or M1 occlusion on 24 h magnetic resonance imaging (MRI) or computed tomography (CT) vascular imaging. Multivariable logistic regression models were used to investigate factors associated with early reocclusion and its impact on outcomes.

RESULTS

Between 2015 and 2020, 62 of 1015 included patients experienced an early reocclusion (6.1%). Age (odds ratio (OR) per 15 years decrease: 1.38 (1.05-1.81)) antiplatelet use (OR: 0.41 (0.19-0.89)), several device passes (OR: 2.13 (1.18-3.83)), atherosclerosis cause (OR: 2.38 (1.19-4.78)), and early clinical worsening (OR: 2.45 (1.18-5.07)) were independently associated with early reocclusion. Early reocclusion was independently associated with poor prognosis (OR: 7.15 (3.49-14.65)) and mortality (OR: 2.05 (1.07-3.91)) at 3 months.

CONCLUSION

Six percent of patients with LAO-related stroke and initial successful recanalization experienced early reocclusion. This event is associated with a 7-fold increased risk of poor functional outcome and a 2-fold increased risk of mortality. Further efforts are warranted to refine early detection of patients at risk of reocclusion and to improve their management.

The impact of the PCSK-9/VLDL-Receptor axis on inflammatory cell polarization

BACKGROUND

Studies have shown that lipoproteins, such as LDL and VLDL, as well as its major protein component ApoE2 impact on macrophage polarization important in atherosclerosis. Proprotein convertase subtilisin/kexin 9 (PCSK9) is a key regulator of lipoprotein receptor expression. The present study investigated the effect of the VLDL/VLDL-receptor (VLDL-R) axis on mononuclear cell polarization, as well as the role of PCSK9 and PCSK9 inhibitors (PCSK9i) within this network.

METHODS

Human monocytic THP-1 cells and human monocyte-derived macrophages isolated from peripheral blood mononuclear cells (PBMC) were treated with either LPS/IFN-γ to induce a pro-inflammatory phenotype, or with IL-4/IL-13 to induce an anti-inflammatory phenotype. Cells were then subjected to further treatments by lipoproteins, PCSK9, PCSK9i and lipoprotein receptor blockers.

RESULTS

LPS/IFN-γ treatment promoted a pro-inflammatory state with an increased expression of pro-inflammatory mediators such as TNF-α, CD80 and IL-1β. VLDL co-treatment induced a switch of this pro-inflammatory phenotype to an anti-inflammatory phenotype. In pro-inflammatory cells, VLDL significantly decreased the expression of pro-inflammatory markers e.g., TNF-α, CD80, and IL-1β. These effects were eliminated by PCSK9 and restored by co-incubation with a specific anti-PCSK9 monoclonal antibody (PCSK9i). Migration assays demonstrated that pro-inflammatory cells displayed a significantly higher invasive capacity when compared to untreated cells or anti-inflammatory cells. Moreover, pro-inflammatory cell chemotaxis was significantly decreased by VLDL-mediated acquisition of the anti-inflammatory phenotype. PCSK9 significantly lessened this VLDL-mediated migration inhibition, which was reversed by the PCSK9i.

CONCLUSION

VLDL promotes mononuclear cell differentiation towards an anti-inflammatory phenotype. PCSK9, via its capacity to inhibit VLDL-R expression, reverses the VLDL-mediated anti-inflammatory action, thereby promoting a pro-inflammatory phenotype. Thus, PCSK9 targeting therapies may exert anti-inflammatory properties within the vessel wall.

Potential Roles of Selectins in Periodontal Diseases and Associated Systemic Diseases: Could They Be Targets for Immunotherapy?

Periodontal diseases are predisposing factors to the development of many systemic disorders, which is often initiated via leukocyte infiltration and vascular inflammation. These diseases could significantly affect human health and quality of life. Hence, it is vital to explore effective therapies to prevent disease progression. Periodontitis, which is characterized by gingival bleeding, disruption of the gingival capillary's integrity, and irreversible destruction of the periodontal supporting bone, appears to be caused by overexpression of selectins in periodontal tissues. Selectins (P-, L-, and E-selectins) are vital members of adhesion molecules regulating inflammatory and immune responses. They are mainly located in platelets, leukocytes, and endothelial cells. Furthermore, selectins are involved in the immunopathogenesis of vascular inflammatory diseases, such as cardiovascular disease, diabetes, cancers, and so on, by mediating leukocyte recruitment, platelet activation, and alteration of endothelial barrier permeability. Therefore, selectins could be new immunotherapeutic targets for periodontal disorders and their associated systemic diseases since they play a crucial role in immune regulation and endothelium dysfunction. However, the research on selectins and their association with periodontal and systemic diseases remains limited. This review aims to discuss the critical roles of selectins in periodontitis and associated systemic disorders and highlights the potential of selectins as therapeutic targets.

Direct Impact of Human Platelets on the Development of Transplant Arteriosclerosis

BACKGROUND

Platelets play an important role in the pathogenesis of inflammatory and proliferative vascular changes. The aim of this study was to investigate whether human platelets are able to induce transplant arteriosclerosis in a humanized C57/Bl6-Rag2-/-γc-/- mouse xenograft model.

METHODS

Nonactivated and in vitro-activated human platelets were analyzed and phenotyped for surface markers by flow cytometry. Side branches of human mammary arteries were implanted into the infrarenal aorta of recipients, followed by daily application of human platelets and histological analyzed on day 30 after transplantation.

RESULTS

Human platelets collected by apheresis had low levels of platelet activation markers. However, after in vitro activation, expression was markedly increased. Sixty minutes after injection in recipient mice, nonactivated human platelets become significantly activated. Increased adhesion of platelets to the vascular endothelium was detected by in vivo fluorescence microscopy. After intravenous injection of nonactivated or activated platelets, human xenografts showed pronounced intimal proliferation. Immunohistological analysis showed that the group treated with activated human platelets exhibited significantly increased intragraft protein expression of intracellular adhesion molecule-1 and platelet-derived growth factor receptor beta and smooth muscle cell migration into the neointima.

CONCLUSIONS

These data demonstrate that an isolated daily application of both in vivo- and in vitro-activated human platelets results in the development of transplant arteriosclerosis in a humanized mouse transplantation model.

Prognostic significance of platelet-to-lymphocyte and platelet-to-neutrophil ratios in patients with mechanical thrombectomy for acute ischemic stroke

Objective

The present study aimed to analyze the correlation between platelet-to-lymphocyte ratio (PLR) and platelet-to-neutrophil ratio (PNR) with prognosis of patients who underwent mechanical thrombectomy (MT).

Methods

A total of 432 patients was included, PLR and PNR were calculated from laboratory data on admission. Prognosis was evaluated with a modified Rankin Scale at 3 months after MT. Using receiver operating characteristic (ROC) analysis, optimal cutoff values of PLR and PNR were identified to predict the prognosis after MT. Multivariate analyses were performed to identify the relationship of PLR and PLR with prognosis of MT.

Results

Patients with favorable outcomes had a lower mean PLR (135.0, standard deviation [SD] 120.3) with a higher mean PNR (47.1 [SD] 24.6) compared with patients with unfavorable outcomes (167.6 [SD] 139.3 and 35.4 [SD] 22.4) (p<0.001 and <0.001, respectively). In ROC analyses, the optimal cutoff value of PLR and PNR to predict the 3 months prognosis were 145 and 41, respectively (p=<0.001 and p=0.006). In multivariate analysis, PLR less than 145 (odds ratio [OR] 1.29, 95% confidence interval [CI] 1.06–2.06; p=0.016) and PNR greater than 41 (OR 1.22, 95% CI 1.10–1.62; p=0.022) were predictors of favorable outcome at 3 months.

Conclusions

In patients with MT, PLR and PNR on admission could be predictive factors of prognosis and mortality at 3 months. Decreased PLR and increased PNR were associated with favorable clinical outcome 3 months after MT.

Platelets, a Key Cell in Inflammation and Atherosclerosis Progression

Platelets play important roles in thrombosis-dependent obstructive cardiovascular diseases. In addition, it has now become evident that platelets also participate in the earliest stages of atherosclerosis, including the genesis of the atherosclerotic lesion. Moreover, while the link between platelet activity and hemostasis has been well established, the role of platelets as modulators of inflammation has only recently been recognized. Thus, through their secretory activities, platelets can chemically attract a diverse repertoire of cells to inflammatory foci. Although monocytes and lymphocytes act as key cells in the progression of an inflammatory event and play a central role in plaque formation and progression, there is also evidence that platelets can traverse the endothelium, and therefore be a direct mediator in the progression of atherosclerotic plaque. This review provides an overview of platelet interactions and regulation in atherosclerosis.

Association between Platelet to Neutrophil Ratio (PNR) and Clinical Outcomes in STEMI Patients after Successful pPCI: A Secondary Analysis Based on a Cohort Study

Purpose

This study was aimed at investigating whether the platelet-to-neutrophil ratio (PNR) is independently related to the prognosis of patients with ST-elevation myocardial infarction (STEMI) after successful primary percutaneous coronary intervention (pPCI).

Methods

This was a secondary analysis of data retrieved from the DATADRYAD database, which was a prospective cohort study. A total of 464 STEMI patients who underwent successful pPCI were recruited between January 2010 and October 2014. The target-independent variable, PNR, was measured at the baseline. The dependent variable in the current study was the occurrence of major adverse cardiovascular events (MACEs) during the 30-month follow-up.

Results

Two patients were excluded from the final analysis because their platelet counts were unavailable. The average age of the 462 participants was 63 ± 11.92 years, and approximately 76.6% were male. After adjusting for age, sex, anterior wall myocardial infarction (MI), history of MI, apelin-12, apelin-12 change rate, left ventricular end-diastolic diameter, peak cardiac troponin I, pathological Q wave, Killip classification grade, fasting blood glucose, albumin, GENSINI score, and estimated glomerular filtration rate, a nonlinear relationship was found between the PNR and MACEs in the included cohort. The threshold value of the PNR for MACEs was 23.1. Over this cutoff value, the incidence rate of MACEs increased by 43% per 10-unit change in PNR (95% CI: 1.16–1.75, p = 0.0006).

Conclusion

There was a threshold relationship between PNR and MACEs in patients with STEMI who underwent successful pPCI. The incidence of MACEs was positively associated with the PNR when the PNR exceeded 23.1.

Changes of Hematological and Hemorheological Parameters in Rabbits with Hypercholesterolemia

Hypercholesterolemia plays an important role in the development of atherosclerosis, leading to endothelial dysfunction, ischemic events, and increased mortality. Numerous studies suggest the pivotal role of rheological factors in the pathology of atherosclerosis. To get a more detailed hematological and hemorheological profile in hypercholesterolemia, we carried out an experiment on rabbits. Animals were divided into two groups: the control group (Control) was kept on normal rabbit chow, the high-cholesterol diet group (HC) was fed with special increased cholesterol-containing food. Hematological parameters (Sysmex K-4500 automate), whole blood and plasma viscosity (Hevimet-40 capillary viscometer), red blood cell (RBC) aggregation (Myrenne MA-1 aggregometer), deformability and mechanical stability (LoRRca MaxSis Osmoscan ektacytometer) were tested. The white blood cell and platelet count, mean corpuscular volume, and mean corpuscular hemoglobin were significantly higher in the HC group, while the RBC count, hemoglobin, and hematocrit values were lower than the Control data. Viscosity values corrected to 40% hematocrit were higher in the HC group. The RBC aggregation significantly increased in the HC vs. the Control. The HC group showed significantly worse results both in RBCs' deformability and membrane stability. In conclusion, the atherogenic diet worsens the hematological and macro- and micro-rheological parameters, affecting blood flow properties and microcirculation.

Endothelial transmigration of platelets depends on soluble factors released by activated endothelial cells and monocytes

Cardiovascular diseases (CVDs) remain leading causes of death worldwide. While platelet-mediated thrombus formation following the rupture of an atherosclerotic plaque is one of the key pathophysiologic events in CVDs, the role of platelets in previous or more advanced stages of atherosclerosis is less known. Interestingly, the presence of platelets has been observed at the core of the atherosclerotic plaque.In order to study the conditions necessary for platelets to migrate toward an atherosclerotic lesion, we designed an in vitro co-culture model. Platelets were co-cultured with monocytes in Transwell inserts covered with a confluent endothelium and the number of migrating platelets and/or monocytes was determined under different conditions. Platelets were also exposed to media conditioned obtained from co-cultures prior to migration assays.Here we show that coculturing platelets and monocytes increased platelet transmigration, with a considerable number of transmigrated platelets found not associated to monocytes. Interestingly, conditioned media from platelet-monocyte co-cultures also increased platelet transmigration and aggregation, suggesting the existence of soluble factors secreted by monocytes that enhance the migratory and pro-aggregating capabilities of platelets.We conclude that platelets have the machinery to migrate through an activated endothelium, a response that requires the interaction with secreted factors produce in the context of the interaction with monocytes under atherogenic conditions.

Resveratrol Confers Vascular Protection by Suppressing TLR4/Syk/NLRP3 Signaling in Oxidized Low-Density Lipoprotein-Activated Platelets

This study investigated the effect of resveratrol on Toll-like receptor 4- (TLR4-) mediated matrix metalloproteinase 3 (MMP3) and MMP9 expression in oxidized low-density lipoprotein- (ox-LDL-) activated platelets and the potential molecule mechanism. Human platelets were used in the present study. The results showed that resveratrol suppressed TLR4, MMP3, and MMP9 expression in ox-LDL-activated platelets. The TLR4 inhibitor CLI-095 also inhibited MMP3 and MMP9 expression and secretion in ox-LDL- and lipopolysaccharide- (LPS-) activated platelets. The combination of resveratrol and CLI-095 synergistically suppressed MMP3 and MMP9 expression in ox-LDL- and LPS-activated platelets. These findings suggest that the resveratrol-induced inhibition of MMP3 and MMP9 expression is linked to the suppression of TLR4 activation. Resveratrol also suppressed spleen tyrosine kinase (Syk) phosphorylation and nucleotide-binding domain leucine-rich repeat containing protein 3 (NLRP3) expression and IL-1β secretion in ox-LDL- and LPS-treated platelets. The coimmunoprecipitation results showed that resveratrol inhibited the binding of Syk and NLRP3. Finally, resveratrol reduced vascular senescence cells and the expression of TLR4, MMP3, and MMP9 and prevented alterations of vascular structure in 52-week-old mice. Our findings demonstrated that resveratrol decreased inflammatory protein expression and improved vascular structure in aged mice. Resveratrol inhibited the expression of TLR4 and secretion of MMP3, MMP9, and IL-1β. The mechanism of action of resveratrol appears to be associated with the inhibition of TLR4/Syk/NLRP3 activation in ox-LDL-activated platelets.

Platelet membrane camouflaged nanoparticles: Biomimetic architecture for targeted therapy

Cell membrane coating strategy is one of the promising techniques for biomimetic functionalization of nanoparticle. The biomimetic nanoparticles camouflage themselves utilizing the fundamental properties of native cells. Cell membranes are extracted from various cells to cloak the nanoparticles for targeted drug delivery. Platelet membrane is one such cell membrane proposing itself as a potential camouflager to escape the immune surveillance and aid prolonged blood circulation with minimum systemic cytotoxicity. Platelets play a very important role in the physiological functions of the body and also feature in few pathological disorders like cancer, atherosclerosis and rheumatoid arthritis. This review comprises of preparation and characterization of platelet membrane camouflaged nanoparticles and also focuses on their recent developments towards targeted therapy in cancer, immune diseases, atherosclerosis and phototherapy. Although platelet membrane camouflaged nanoparticles are currently in the preliminary stage of development, there is huge potential to explore this biodegradable and biocompatible delivery system.

Targeting Platelet in Atherosclerosis Plaque Formation: Current Knowledge and Future Perspectives

Besides their role in hemostasis and thrombosis, it has become increasingly clear that platelets are also involved in many other pathological processes of the vascular system, such as atherosclerotic plaque formation. Atherosclerosis is a chronic vascular inflammatory disease, which preferentially develops at sites under disturbed blood flow with low speeds and chaotic directions. Hyperglycemia, hyperlipidemia, and hypertension are all risk factors for atherosclerosis. When the vascular microenvironment changes, platelets can respond quickly to interact with endothelial cells and leukocytes, participating in atherosclerosis. This review discusses the important roles of platelets in the plaque formation under pro-atherogenic factors. Specifically, we discussed the platelet behaviors under disturbed flow, hyperglycemia, and hyperlipidemia conditions. We also summarized the molecular mechanisms involved in vascular inflammation during atherogenesis based on platelet receptors and secretion of inflammatory factors. Finally, we highlighted the studies of platelet migration in atherogenesis. In general, we elaborated an atherogenic role of platelets and the aspects that should be further studied in the future.

Activated Platelets Induce Endothelial Cell Inflammatory Response in Psoriasis via COX-1

OBJECTIVE

Patients with psoriasis have impaired vascular health and increased cardiovascular disease (CVD). Platelets are key players in the pathogenesis of vascular dysfunction in cardiovascular disease and represent therapeutic targets in cardiovascular prevention. The object of this study was to define the platelet phenotype and effector cell properties on vascular health in psoriasis and evaluate whether aspirin modulates the platelet-induced phenotype. Approach and Results: Platelets from psoriasis patients (n=45) exhibited increased platelet activation (relative to age- and gender-matched controls, n=18), which correlated with psoriasis skin severity. Isolated platelets from psoriasis patients demonstrated a 2- to 3-fold (P<0.01) increased adhesion to human aortic endothelial cells and induced proinflammatory transcriptional changes, including upregulation of IL 8 (interleukin 8), IL1β, and Cox (cyclooxygenase)-2 Platelet RNA sequencing revealed an interferon signature and elevated expression of COX-1, which correlated with psoriasis disease severity (r=0.83, P=0.01). In a randomized trial of patients with psoriasis, 2 weeks of 81 mg low-dose aspirin, a COX-1 inhibitor, reduced serum thromboxane (Tx) B2 and reduced brachial vein endothelial proinflammatory transcript expression >70% compared with the no-treatment group (P<0.01). Improvement in brachial vein endothelial cell inflammation significantly correlated with change in serum TxB2 (r=0.48, P=0.02).

CONCLUSIONS

In patients with psoriasis, platelets are activated and induce endothelial cell inflammation. Low-dose aspirin improved endothelial cell health in psoriasis via platelet COX-1 inhibition. These data demonstrate a previously unappreciated role of platelets in psoriasis and endothelial cell inflammation and suggests that aspirin may be effective in improving vascular health in patients with psoriasis. Registration: URL: http://www.clinicaltrials.gov. Unique identifier: NCT03228017.

Platelet activation and prothrombotic mediators at the nexus of inflammation and atherosclerosis: Potential role of antiplatelet agents

Platelets are central to inflammation-related manifestations of cardiovascular diseases (CVD) such as atherosclerosis. Platelet-activating factor (PAF), thrombin, thromboxane A₂ (TxA₂), and adenosine diphosphate (ADP) are some of the key agonists of platelet activation that are at the intersection between a plethora of inflammatory pathways that modulate pro-inflammatory and coagulation processes. The aim of this article is to review the role of platelets and the relationship between their structure, function, and the interactions of their constituents in systemic inflammation and atherosclerosis. Antiplatelet therapies are discussed with a view to primary prevention of CVD by the clinical reduction of platelet reactivity and inflammation. Current antiplatelet therapies are effective in reducing cardiovascular risk but increase bleeding risk. Novel therapeutic antiplatelet approaches beyond current pharmacological modalities that do not increase the risk of bleeding require further investigation. There is potential for specifically designed nutraceuticals that may become safer alternatives to pharmacological antiplatelet agents for the primary prevention of CVD but there is serious concern over their efficacy and regulation, which requires considerably more research.

Anti‑platelet activity of mineral‑balanced deep sea water is mediated via the regulation of Akt and ERK pathway crosstalk

Mineral‑balanced deep sea water (MBDSW), an unlimited natural sea source, has been demonstrated to minimize the risk of developing cardiovascular diseases, such as obesity, hypertension, inflammation and hyperlipidemia. This study investigated the effects of MBDSW [magnesium (Mg):calcium (Ca) ratio, 3:1] on platelet activation. MBDSW significantly inhibited the collagen‑ and thrombin‑induced platelet aggregation of human platelets. In collagen‑induced platelets, MBDSW inhibited intracellular calcium mobilization, granule secretion [serotonin, adenosine triphosphate (ATP) and P‑selectin expression] and thromboxane A2 (TXA2) production. Moreover, MBDSW markedly inhibited Akt and extracellular signal‑regulated kinase (ERK) phosphorylation, but not that of c‑Jun N‑terminal kinase (JNK) and p38. Moreover, MBDSW phosphorylated inositol 1,4,5‑triphosphate receptor (IP3R) and vasodilator‑stimulated phosphoprotein (VASP), and it increased the cyclic adenosine monophosphate (cAMP) level in collagen‑induced human platelets. Dipyridamole, a phosphodiesterase (PDE) inhibitor, significantly increased the cAMP level and regulated the Akt, ERK and VASP (Ser157) levels in a manner similar to that of MBDSW. In addition, LY294002, an Akt inhibitor, inhibited the phosphorylation of ERK, and U0126, an ERK inhibitor, inhibited the phosphorylation of Akt. Taken together, the results of the present investigation suggest that the inhibitory effects of MBDSW on platelet aggregation may be associated with the cross‑inhibition of Akt and ERK phosphorylation. These results strongly indicate that MBDSW may have preventive or therapeutic potential for platelet aggregation‑mediated diseases, such as thrombosis, atherosclerosis and myocardial infarction.

Platelet-to-lymphocyte and neutrophil-to-lymphocyte ratios as markers of erythropoietin resistance in chronic haemodialysis patients: a multicentre cross-sectional study

INTRODUCTION

The platelet-to-lymphocyte (PLR) and neutrophil-to-lymphocyte (NLR) ratios are emerging markers of inflammation. Erythropoietin resistance is associated with increased morbidity and mortality in patients with chronic kidney disease and is influenced by inflammation, among other factors. Therefore, it would be reasonable to expect a relationship between these markers and erythropoietin resistance.

METHODS

Multicentre cross-sectional study. The records of the haemodialysis sessions of 534 patients belonging to four of our dialysis centres were studied. 137 patients were excluded, so the final number of patients studied was 397. NLR, PLR and the erythropoietin resistance index (ERI) were calculated.

RESULTS

The ERI was divided into quartiles and compared with the mean NLR and PLR of the four groups, with these differences being statistically significant (p=0.00058). In the regression analysis, the NLR value was able to predict ERI significantly (p<0.0001) (R²=0.029). The PLR value also predicted ERI significantly (p<0.0001) (R²=0.103). The ability of PLR to predict erythropoietin resistance was measured with the area under the ROC curve (AUC=0.681) (95% CI, 0.541-0.821). A PLR cut-off point of 125.5 would result in a sensitivity of 80.95% and 42.82% specificity.

CONCLUSIONS

Both PLR and NLR could be considered acceptable markers of erythropoietin resistance. The PLR was a better predictor for the ERI than the NLR.

The association between platelet/lymphocyte ratio, neutrophil/lymphocyte ratio, and carotid artery stenosis and stroke following carotid endarterectomy

Objectives

Platelet/lymphocyte ratio is considered to be a recent biomarker which is not only related with inflammation but also associated with the atherosclerotic process. In this study, we aimed to investigate the relationship between carotid artery stenosis, platelet/lymphocyte ratio, neutrophil/lymphocyte ratio, and mean platelet volume in patients undergoing carotid endarterectomy.

Methods

A total of 160 patients (127 males, 33 females; mean age 69.98 ± 9.76 years; range 48–92 years), who were undergoing carotid endarterectomy due to severe carotid artery stenosis, were evaluated and compared with 201 patients (140 males, 61 females, mean age 66.30 ± 9.24 years, range 41–90 years) without severe carotid artery stenosis. The patients were divided into four groups with respect to the carotid artery stenosis as: Group I (<50% stenosis), Group II (50–70% stenosis), Group III (70–90% stenosis), and Group IV (90–99% stenosis).

Results

Platelet/lymphocyte ratio, neutrophil/lymphocyte ratio and mean platelet volume were found higher in Group IV (patients with severe carotid artery stenosis) (p < 0.01) and were positively correlated with the degree of stenosis (p < 0.01). Platelet/lymphocyte ratio is an independent predictor for post operative stroke (p = 0.047) at multivariate analysis. A threshold level of 145.304 of platelet/lymphocyte ratio combined with a sensitivity 83.3% and specificity 73.8% (95% CI, 0.802–0.921, area under the curve = 0.862 ± 0.03; p = 0.002) for the identification of post operative stroke.

Conclusions

This retrospective study suggests that platelet/lymphocyte ratio in the blood which was taken preoperatively could be considered as an additional, easy, and inexpensive method to predict a possible higher incidence of postoperative stroke after carotid endarterectomy.

The Role of Transient Receptor Potential Vanilloid 1 in Common Diseases of the Digestive Tract and the Cardiovascular and Respiratory System

Transient receptor potential vanilloid subtype 1 (TRPV1), a member of the transient receptor potential vanilloid (TRPV) channel family, is a nonselective cation channel that is widely expressed in sensory nerve fibers and nonneuronal cells, including certain vascular endothelial cells and smooth muscle cells. The activation of TRPV1 may be involved in the regulation of various physiological functions, such as the release of inflammatory mediators in the body, gastrointestinal motility function, and temperature regulation. In recent years, a large number of studies have revealed that TRPV1 plays an important role in the physiological and pathological conditions of the digestive system, cardiovascular system, and respiratory system, but there is no systematic report on TRPV1. The objective of this review is to explain the function and effects of TRPV1 on specific diseases, such as irritable bowel syndrome, hypertension, and asthma, and to further investigate the intrinsic relationship between the expression and function of TRPV1 in those diseases to find new therapeutic targets for the cure of related diseases.

Engineering Cell Membrane-Based Nanotherapeutics to Target Inflammation

Inflammation is ubiquitous in the body, triggering desirable immune response to defend against dangerous signals or instigating undesirable damage to cells and tissues to cause disease. Nanomedicine holds exciting potential in modulating inflammation. In particular, cell membranes derived from cells involved in the inflammatory process may be used to coat nanotherapeutics for effective targeted delivery to inflammatory tissues. Herein, the recent progress of rationally engineering cell membrane-based nanotherapeutics for inflammation therapy is highlighted, and the challenges and opportunities presented in realizing the full potential of cell-membrane coating in targeting and manipulating the inflammatory microenvironment are discussed.

Emerging Roles for Eph Receptors and Ephrin Ligands in Immunity

Eph receptors are the largest family of receptor tyrosine kinases and mediate a myriad of essential processes in humans from embryonic development to adult tissue homeostasis through interactions with membrane-bound ephrin ligands. The ubiquitous expression of Eph receptors and ephrin ligands among the cellular players of the immune system underscores the importance of these molecules in orchestrating an optimal immune response. This review provides an overview of the various roles of Eph receptors and ephrin ligands in immune cell development, activation, and migration. We also discuss the role of Eph receptors in disease pathogenesis as well as the implications of Eph receptors as future immunotherapy targets. Given the diverse and critical roles of Eph receptors and ephrin ligands throughout the immune system during both resting and activated states, this review aims to highlight the critical yet underappreciated roles of this family of signaling molecules in the immune system.

Can Yellow Stripe Scad Compete with Salmon on Its Role in Platelet Phospholipid Membrane and Its Cardiovascular Benefits?

This review article stresses the effective role of dietary fish fillet docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) on overweight as a risk factor of cardiovascular disease (CVD) via platelet phospholipid modification. Several reports have demonstrated that saturated fat in overweight evokes systemic inflammation and more importantly predisposes it to cardiovascular disorder. Prospective studies have shown that saturated fat is directly proportional to the level of arachidonic acids (AA), precursor of thromboxane in the platelet phospholipid membrane as omega-6 fatty acid in overweight and obese people. Some literature has demonstrated that omega-3 fatty acid from fish fillet ameliorates inflammation, reduces proinflammatory cytokine, inhibits signaling pathway, and regulates the physical composition of inflammatory leukocytes and free radicals (ROS). Yellow stripe scad (YSS) is a local Malaysian fish that has been shown to contain a comparable level of EPA/DHA content as observed in salmon. This review article will focus on the dietary role of fish fillet that will balance the omega-6 fatty acid/omega-3 fatty acid ratio in platelet phospholipid from YSS to manage and prevent healthy overweight/obesity-related risk factor of CVD and to avoid the risk orthodox drug treatment.

Cardiovascular injury induced by tobacco products: assessment of risk factors and biomarkers of harm. A Tobacco Centers of Regulatory Science compilation

Although substantial evidence shows that smoking is positively and robustly associated with cardiovascular disease (CVD), the CVD risk associated with the use of new and emerging tobacco products, such as electronic cigarettes, hookah, and heat-not-burn products, remains unclear. This uncertainty stems from lack of knowledge on how the use of these products affects cardiovascular health. Cardiovascular injury associated with the use of new tobacco products could be evaluated by measuring changes in biomarkers of cardiovascular harm that are sensitive to the use of combustible cigarettes. Such cardiovascular injury could be indexed at several levels. Preclinical changes contributing to the pathogenesis of disease could be monitored by measuring changes in systemic inflammation and oxidative stress, organ-specific dysfunctions could be gauged by measuring endothelial function (flow-mediated dilation), platelet aggregation, and arterial stiffness, and organ-specific injury could be evaluated by measuring endothelial microparticles and platelet-leukocyte aggregates. Classical risk factors, such as blood pressure, circulating lipoproteins, and insulin resistance, provide robust estimates of risk, and subclinical disease progression could be followed by measuring coronary artery Ca2+ and carotid intima-media thickness. Given that several of these biomarkers are well-established predictors of major cardiovascular events, the association of these biomarkers with the use of new and emerging tobacco products could be indicative of both individual and population-level CVD risk associated with the use of these products. Differential effects of tobacco products (conventional vs. new and emerging products) on different indexes of cardiovascular injury could also provide insights into mechanisms by which they induce cardiovascular harm.

Chemical Characterization and Antiplatelet Potential of Bioactive Extract from Tomato Pomace (Byproduct of Tomato Paste)

We examined the ability of tomato pomace extract (by-product) to affect platelet aggregation in healthy humans (clinical pilot study). In phase 1 the tolerance of participants (n = 15; 5 per dose level) ingesting tomato pomace extract across three dose levels (1, 2.5, and 10 g) was evaluated. Phase 2 was a single-blind, placebo-controlled, parallel design human (male, n = 99; 33 per group) pilot intervention trial investigating the acute and repeated dose effects (5 days) of different doses of tomato pomace extract (1 g, 2.5 g or placebo) on platelet aggregation ex vivo. Various flavonoids (coumaric acid, floridzin, floretin, procyanidin B₂, luteolin-7-O-glucoside, kaempferol, and quercitin) and nucleosides (adenosine, inosine, and guanosine) were identified in the tomato pomace extract. The clinical study showed that the daily consumption of 1 g of aqueous extract of tomato pomace for 5 days exerted an inhibitory activity on platelet aggregation.

Potentially critical roles of TNPO1, RAP1B, ZDHHC17, and PPM1B in the progression of coronary atherosclerosis through microarray data analysis

OBJECTIVE

This study aimed to identify more potentially critical genes associated with atherosclerotic coronary artery disease (CAD).

MATERIALS AND METHODS

Gene expression profile of GSE12288 was downloaded from the Gene Expression Omnibus (GEO) database. Differentially expressed genes (DEGs) were screened in atherosclerotic CAD samples compared with controls, followed by weighed gene coexpression network analysis (WGCNA) by which the most significant module was identified. Gene coexpression network was constructed based on genes in the most significant module, and functional annotation was also performed. In addition, microRNAs (miRNAs) that were directly associated with CAD were screened from the literature, and the miRNA-target regulatory network was constructed based on genes in the most significant module, followed by Gene Ontology (GO) and pathway enrichment analysis. Furthermore, we used another data set of GSE42148 from the GEO database to perform data validation.

RESULTS

WGCNA analysis showed that the turquoise module may have the most important role in atherosclerotic CAD. Genes in this module were involved in translational elongation and intracellular signal transduction. Besides, we identified five confirmed CAD-related miRNAs. TNPO1, RAP1B, and ZDHHC17 could be targeted by four of these miRNAs. Genes such as PPM1B could be regulated by three miRNAs. Moreover, TNPO1 and ZDHHC17 were involved in the GO terms associated with protein localization and transport and the immune system; RAP1B and PPM1B were linked with intracellular signal transduction-related pathways. In addition, PPM1B and ZDHHC17 had accordantly significant expression changes in another data set GSE42148.

CONCLUSION

TNPO1, RAP1B, ZDHHC17, and PPM1B may play essential roles in the progression of coronary atherosclerosis.

Radiopaque nano and polymeric materials for atherosclerosis imaging, embolization and other catheterization procedures

A review of radiopaque nano and polymeric materials for atherosclerosis imaging and catheterization procedures is presented in this paper. Cardiovascular diseases (CVDs) are the leading cause of death in the US with atherosclerosis as a significant contributor for mortality and morbidity. In this review paper, we discussed the physics of radiopacity and X-ray/CT, clinically used contrast agents, and the recent progress in the development of radiopaque imaging agents and devices for the diagnosis and treatment of CVDs. We focused on radiopaque imaging agents for atherosclerosis, radiopaque embolic agents and drug eluting beads, and other radiopaque medical devices related to catheterization procedures to treat CVDs. Common strategies of introducing radiopacity in the polymers, together with examples of their applications in imaging and medical devices, are also presented.

Nanoparticle Functionalization with Platelet Membrane Enables Multifactored Biological Targeting and Detection of Atherosclerosis

Cardiovascular disease represents one of the major causes of death across the global population. Atherosclerosis, one of its most common drivers, is characterized by the gradual buildup of arterial plaque over time, which can ultimately lead to life-threatening conditions. Given the impact of the disease on public health, there is a great need for effective and noninvasive imaging modalities that can provide valuable information on its biological underpinnings during development. Here, we leverage the role of platelets in atherogenesis to design nanocarriers capable of targeting multiple biological elements relevant to plaque development. Biomimetic nanoparticles are prepared by coating platelet membrane around a synthetic nanoparticulate core, the product of which is capable of interacting with activated endothelium, foam cells, and collagen. The effects are shown to be exclusive to platelet membrane-coated nanoparticles. These biomimetic nanocarriers are not only capable of efficiently localizing to well-developed atherosclerotic plaque, but can also target subclinical regions of arteries susceptible to plaque formation. Using a commonly employed magnetic resonance imaging contrast agent, live detection is demonstrated using an animal model of atherosclerosis. Ultimately, this strategy may be leveraged to better assess the development of atherosclerosis, offering additional information to help clinicians better manage the disease.

Antiplatelet mechanism of an herbal mixture prepared from the extracts of Phyllostachys pubescens leaves and Prunus mume fruits

Background

Bamboo (Phyllostachys pubescens) leaves and Japanese apricot (Mume fructus) fruit are traditionally recognized to be safe herbs broadly used for food and medicinal purposes in Southeast Asia. Our group previously explored their antiplatelet effects. This study was designed to confirm inhibition effects of PM21 (a 2:1 mixture of bamboo leaf extract and Japanese apricot fruit extract) on platelet aggregation and evaluate its potency to use as an herbal remedy to prevent and/or treat the diseases caused by platelet aggregation and thrombus formation.

Methods

Washed platelets were prepared and platelet aggregation was induced by adding 5 μg/mL collagen. Anti-platelet effects of PM21 (75 mg/kg, 150 mg/kg, and 300 mg/kg for ex vivo and in vivo assays, and 50, 100, 200 μg/mL for in vitro assays) were evaluated. In ex vivo assays, PM21 was orally administered to rats daily after overnight fasting for 3 days and blood was collected 1 h after the final treatment. In vivo antithrombotic effect of PM21 was observed from a carrageenan induced mouse tail thrombosis model.

Results

In ex vivo assay, PM21 inhibited platelet aggregation significantly. PM21 showed a strong antithrombotic effect by reducing significantly the length of mouse tail thrombus. PM21 increased intracellular cAMP level and reduced the release of ATP, TXA₂, and serotonin. PM21 also reduced intracellular concentration of calcium ion, fibrinogen binding to integrin α_IIbβ₃, and phosphorylation of ERK2, p38, PLCγ2, and PI3 K.

Conclusions

PM21 showed remarkable inhibitory effects on platelet aggregation and thrombus formation. Its inhibitory function seems to influence on GPVI binding to its ligand and subsequent initiation of a signaling cascade that involves activation of effector proteins and secretion of effector molecules, such as ATP, TXA₂, serotonin, and Ca²⁺. PM21 also appears to exert its anti-platelet effect by deactivation of ERKs activation pathway as well as inhibition of fibrinogen binding to integrin α_IIbβ₃.

New Insights into the Role of Inflammation in the Pathogenesis of Atherosclerosis

Atherosclerosis is a chronic inflammatory disease characterized by the accumulation of lipids, smooth muscle cell proliferation, cell apoptosis, necrosis, fibrosis, and local inflammation. Immune and inflammatory responses have significant effects on every phase of atherosclerosis, and increasing evidence shows that immunity plays a more important role in atherosclerosis by tightly regulating its progression. Therefore, understanding the relationship between immune responses and the atherosclerotic microenvironment is extremely important. This article reviews existing knowledge regarding the pathogenesis of immune responses in the atherosclerotic microenvironment, and the immune mechanisms involved in atherosclerosis formation and activation.

Preventive and therapeutic effect of brozopine on stroke in Dahl Salt-sensitive hypertensive rats

Our aim was to explore the preventive and therapeutic effects of sodium (±)-5-bromo-2-(α-hydroxypentyl) benzoate (brand name: brozopine, BZP) on stroke in Dahl Salt-sensitive (Dahl-SS) hypertensive rats. Dahl-SS rats were fed a high-salt diet to observe the effect of BZP on blood pressure, and brain, heart, and kidney tissues. Additionally, the incidence of stroke was recorded according to the neurological score. The relative mechanisms investigated included anti-oxidative effects and anti-platelet aggregation. BZP reduced the incidence of stroke, neuronal necrosis in the brain, and cell swelling and inflammatory infiltration in the kidney. Its mechanisms were related to the increased activities of gluthatione peroxidase and catalase and the decreased level of plasma nitric oxide. BZP inhibited arachidonic acid (AA) - induced platelet aggregation (IC₅₀: 12µM) rather than that of adenosine diphosphate (ADP) - and/or thrombin-induced platelet aggregation in vitro. Interestingly, BZP inhibited ADP-, thrombin-, or AA-induced platelet aggregation and elevated the level of AMP-activated protein kinase, cyclic guanosine monophosphate, and vasodilator-stimulated-phosphoprotein, and attenuated ATP contents and mitogen-activated protein kinase levels in platelet and inhibited thrombus formation in a carotid artery thrombosis model, dose-dependently, in Dahl-SS hypertensive-induced stroke rats. In conclusion, BZP can have therapeutic and preventive effects on stroke in Dahl-SS hypertensive rats, the mechanisms of which may be related to anti-oxidant, anti-platelet aggregation and anti-thrombus formation.

In Vitro and Ex Vivo Approaches to Evaluate Next-Generation Tobacco and Non-Tobacco Products on Human Blood Platelets

Human blood platelets are major hemostatic regulators in the circulation and important in the mediation of chronic inflammation and immunomodulation. They are key elements that promote cardiovascular pathogenesis that leads to atherosclerosis, thrombosis, myocardial infarction, and stroke. New information on tobacco use and platelet dysregulation shows that these highly understudied vascular cells are dysregulated by tobacco smoke. Thus, platelet function studies should be an important consideration for the evaluation of existing and next-generation tobacco and non-tobacco products. Novel in vitro approaches are being sought to investigate these products and their influence on platelet function. Platelets are ideally suited for product assessment, as robust and novel in vitro translational methods are available to assess platelet function. Furthermore, the use of human biological systems has the advantage that risk predictions will better reflect the human condition.

Platelets and von Willebrand factor in atherogenesis

The role of platelet adhesion, activation, and aggregation in acute atherothrombotic events such as myocardial infarction and stroke is well established. There is increasing evidence that platelet-endothelial interactions also contribute to early atherosclerotic plaque initiation and growth. Through these interactions, platelet-derived factors can contribute to the proinflammatory and mitogenic status of resident mural cells. Among the many putative mechanisms for platelet-endothelial interactions, increased endothelial-associated von Willebrand factor, particularly in a multimerized form, which interacts with platelet glycoproteins and integrins, is a major factor and represents a therapeutic target in early atherogenesis.

Platelet secretion in inflammatory and infectious diseases

Platelets are small, anucleate circulating cells that possess a dynamic repertoire of functions spanning the hemostatic, inflammatory, and immune continuum. Once thought to be merely cell fragments with responses limited primarily to acute hemostasis and vascular wall repair, platelets are now increasingly recognized as key sentinels and effector cells regulating host responses to many inflammatory and infectious cues. Platelet granules, including α-granules and dense-granules, store hundreds of factors and secrete these mediators in response to activating signals. The cargo packaged and stored within platelet granules orchestrates communication between platelets and other circulating cells, augments host defense mechanisms to invading pathogens and tumor cells, and - in some settings - drives dysregulated and injurious responses. This focused review will highlight several of the established and emerging mechanisms and roles of platelet secretion in inflammatory and infectious diseases.

Human cells involved in atherosclerosis have a sex

The influence of sex has been largely described in cardiovascular diseases. Atherosclerosis is a complex process that involves many cell types such as vessel cells, immune cells and endothelial progenitor cells; however, many, if not all, studies do not report the sex of the cells. This review focuses on sex differences in human cells involved in the atherosclerotic process, emphasizing the role of sex hormones. Furthermore, we report sex differences and issues related to the processes that determine the fate of the cells such as apoptotic and autophagic mechanisms. The analysis of the data reveals that there are still many gaps in our knowledge regarding sex influences in atherosclerosis, largely for the cell types that have not been well studied, stressing the urgent need for a clear definition of experimental conditions and the inclusion of both sexes in preclinical studies.

Medicinal Plants with Antiplatelet Activity

Blood platelets play an essential role in the hemostasis and wound-healing processes. However, platelet hyperactivity is associated to the development and the complications of several cardiovascular diseases. In this sense, the search for potent and safer antiplatelet agents is of great interest. This article provides an overview of experimental studies performed on medicinal plants with antiplatelet activity available through literature with particular emphasis on the bioactive constituents, the parts used, and the various platelet signaling pathways modulated by medicinal plants. From this review, it was suggested that medicinal plants with antiplatelet activity mainly belong to the family of Asteraceae, Rutaceae, Fabaceae, Lamiaceae, Zygophyllaceae, Rhamnaceae, Liliaceae, and Zingiberaceae. The antiplatelet effect is attributed to the presence of bioactive compounds such as polyphenols, flavonoids, coumarins, terpenoids, and other substances which correct platelet abnormalities by interfering with different platelet signalization pathways including inhibition of the ADP pathway, suppression of TXA2 formation, reduction of intracellular Ca(2+) mobilization, and phosphoinositide breakdown, among others. The identification and/or structure modification of the plant constituents and the understanding of their action mechanisms will be helpful in the development of new antiplatelet agents based on medicinal plants which could contribute to the prevention of thromboembolic-related disorders by inhibiting platelet aggregation. Copyright © 2016 John Wiley & Sons, Ltd.

Bioavailability of Alfrutamide and Caffedymine and Their P-Selectin Suppression and Platelet-Leukocyte Aggregation Mechanisms in Mice

BACKGROUND

Alfrutamide and caffedymine are phenolic amides found in plants, including garlic and cocoa. However, the bioavailability of alfrutamide and caffedymine and their effects on cardiovascular diseases (CVDs), particularly via effects on P-selectin expression(PSE) and platelet-leukocyte aggregation (PLA), are unknown.

OBJECTIVE

The objective of this study was to investigate the bioavailability of alfrutamide and caffedymine and their effects on PSE and PLA, which are frequently involved in the progression of CVDs.

METHODS

Cyclooxygenase (COX) I and COX-II activities and cAMP were determined by using COX and cAMP kits. Bioavailability was determined by HPLC analysis of plasma samples from Swiss Webster mice orally administered alfrutamide and caffedymine (10 μg each). PSE and PLA were also measured by flow cytometry using blood samples from the same mice.

RESULTS

At 0.05 μmol/L, alfrutamide and caffedymine inhibited COX-I and COX-II by 20-40% (P < 0.05) and 16-33% (P < 0.05), respectively, compared with the control. At 0.1 μmol/L, the 2 compounds also inhibited platelet PSE by 28% (P < 0.05) and 35% (P < 0.05), respectively, compared with the control. The β2-adrenoceptor antagonists ICI118551 and butoxamine partially suppressed the inhibition of PSE by caffedymine, suggesting that β2 receptors are involved in inhibition by caffedymine but not by alfrutamide. At the same concentration (0.1 μmol/L), however, these 2 compounds inhibited PLA by 24-32% (P < 0.05) compared with the control. In addition, mice administered caffedymine and alfrutamide orally (10 μg/35 g body weight) exhibited maximum concentrations >0.6 μmol/L and significant inhibition of PSE by 23-34% (P < 0.05) and PLA by 20-27% (P < 0.05) compared with control mice.

CONCLUSIONS

These data show the adequate bioavailability of alfrutamide and caffedymine and their different mechanisms of suppressing PSE and PLA: alfrutamide exerts its effects only via COX inhibition, whereas caffedymine works through both COX inhibition and cAMP amplification.

Erythrocyte and platelet proteomics in hematological disorders

Erythrocytes undergo ineffective erythropoesis, hemolysis, and premature eryptosis in sickle cell disease and thalassemia. Abnormal hemoglobin variants associated with hemoglobinopathy lead to vesiculation, membrane instability, and loss of membrane asymmetry with exposal of phosphatidylserine. This potentiates thrombin generation resulting in activation of the coagulation cascade responsible for subclinical phenotypes. Platelet activation also results in the release of microparticles, which express and transfer functional receptors from platelet membrane, playing key roles in vascular reactivity and activation of intracellular signaling pathways. Over the last decade, proteomics had proven to be an important field of research in studies of blood and blood diseases. Blood cells and its fluidic components have been proven to be easy systems for studying differential expressions of proteins in hematological diseases encompassing hemoglobinopathies, different types of anemias, myeloproliferative disorders, and coagulopathies. Proteomic studies of erythrocytes and platelets reported from several groups have highlighted various factors that intersect the signaling networks in these anucleate systems. In this review, we have elaborated on the current scenario of anucleate blood cell proteomes in normal and diseased individuals and the cross-talk between the two major constituent cell types of circulating blood.

N-Acetylneuraminic acid attenuates hypercoagulation on high fat diet-induced hyperlipidemic rats

Background and objective

N-Acetylneuraminic acid (Neu5Ac), a type of sialic acid, has close links with cholesterol metabolism and is often used as a biomarker in evaluating the risk of cardiovascular diseases. However, most studies on the health implications of Neu5Ac have focused on its effects on the nervous system, while its effects on cardiovascular risk factors have largely been unreported. Thus, the effects of Neu5Ac on coagulation status in high fat diet (HFD)-induced hyperlipidemic rats were evaluated in this study.

Methods

Sprague Dawley male rats were divided into five different groups and fed with HFD alone, HFD low-dose Neu5Ac, HFD high-dose Neu5Ac, HFD simvastatin (10 mg/kg day), and normal pellet alone. Food was given ad libitum while body weight of rats was measured weekly. After 12 weeks of intervention, rats were sacrificed and serum and tissue samples were collected for biochemistry and gene expression analysis, respectively.

Results

The results showed that Neu5Ac could improve lipid metabolism and hyperlipidemia-associated coagulation. Neu5Ac exerted comparable or sometimes better physiological effects than simvastatin, at biochemical and gene expression levels.

Conclusions

The data indicated that Neu5Ac prevented HFD-induced hyperlipidemia and associated hypercoagulation in rats through regulation of lipid-related and coagulation-related genes and, by extension, induced metabolite and protein changes. The implications of the present findings are that Neu5Ac may be used to prevent coagulation-related cardiovascular events in hyperlipidemic conditions. These findings are worth studying further.

Platelet density per monocyte predicts adverse events in patients after percutaneous coronary intervention

Monocyte recruitment to damaged endothelium is enhanced by platelet binding to monocytes and contributes to vascular repair. Therefore, we studied whether the number of platelets per monocyte affects the recurrence of adverse events in patients after percutaneous coronary intervention (PCI). Platelet-monocytes complexes with high and low median fluorescence intensities (MFI) of the platelet marker CD42b were isolated using cell sorting. Microscopic analysis revealed that a high platelet marker MFI on monocytes corresponded with a high platelet density per monocyte while a low platelet marker MFI corresponded with a low platelet density per monocyte (3.4 ± 0.7 vs 1.4 ± 0.1 platelets per monocyte, P=0.01). Using real-time video microscopy, we observed increased recruitment of high platelet density monocytes to endothelial cells as compared with low platelet density monocytes (P=0.01). Next, we classified PCI scheduled patients (N=263) into groups with high, medium and low platelet densities per monocyte and assessed the recurrence of adverse events. After multivariate adjustment for potential confounders, we observed a 2.5-fold reduction in the recurrence of adverse events in patients with a high platelet density per monocyte as compared with a low platelet density per monocyte [hazard ratio=0.4 (95% confidence interval, 0.2-0.8), P=0.01]. We show that a high platelet density per monocyte increases monocyte recruitment to endothelial cells and predicts a reduction in the recurrence of adverse events in patients after PCI. These findings may imply that a high platelet density per monocyte protects against recurrence of adverse events.

Anti-citrullinated protein antibodies contribute to platelet activation in rheumatoid arthritis

Introduction

Although the role of platelets in rheumatoid arthritis (RA) is relatively unexplored, recent studies point towards a contribution of platelets in arthritis. We set out to determine platelet phenotype in RA and studied whether this could be influenced by the presence of anti-citrullinated protein antibodies (ACPA).

Methods

Platelets from healthy controls were incubated in the presence of plasma of patients with RA or age- and sex-matched healthy controls and plasma from ACPA^neg or ACPA^pos patients or in the presence of plate-bound ACPA. Characteristics of platelets isolated from patients with RA were correlated to disease activity.

Results

Platelets isolated from healthy controls displayed markers of platelet activation in the presence of plasma derived from RA patients, as determined by P-selectin expression, formation of aggregates and secretion of soluble CD40 ligand (sCD40L). Furthermore, levels of P-selectin expression and sCD40L release correlated with high ACPA titres. In accordance with these findings, enhanced platelet activation was observed after incubation with ACPA^pos plasma versus ACPA^neg plasma. Pre-incubation of platelets with blocking antibodies directed against low-affinity immunoglobulin G receptor (FcγRIIa) completely inhibited the ACPA-mediated activation. In addition, expression of P-selectin measured as number of platelets correlated with Disease Activity Score in 44 joints, C-reactive protein level, ACPA status and ACPA level.

Conclusions

We show for the first time that ACPA can mediate an FcγRIIa-dependent activation of platelets. As ACPA can be detected several years before RA disease onset and activated platelets contribute to vascular permeability, these data implicate a possible role for ACPA-mediated activation of platelets in arthritis onset.

Electronic supplementary material

The online version of this article (doi:10.1186/s13075-015-0665-7) contains supplementary material, which is available to authorized users.

Molecular anatomy of ascending aorta in atherosclerosis by MS Imaging: Specific lipid and protein patterns reflect pathology

The molecular anatomy of healthy and atherosclerotic tissue is pursued here to identify ongoing molecular changes in atherosclerosis development. Subclinical atherosclerosis cannot be predicted and novel therapeutic targets are needed. Mass spectrometry imaging (MSI) is a novel unexplored ex vivo imaging approach in CVD able to provide in-tissue molecular maps. A rabbit model of early atherosclerosis was developed and high-spatial-resolution MALDI-MSI was applied to comparatively analyze histologically-based arterial regions of interest from control and early atherosclerotic aortas. Specific protocols were applied to identify lipids and proteins significantly altered in response to atherosclerosis. Observed protein alterations were confirmed by immunohistochemistry in rabbit tissue, and additionally in human aortas. Molecular features specifically defining different arterial regions were identified. Localized in the intima, increased expression of SFA and lysolipids and intimal spatial organization showing accumulation of PI, PG and SM point to endothelial dysfunction and triggered inflammatory response. TG, PA, SM and PE-Cer were identified specifically located in calcified regions. Thymosin β4 (TMSB4X) protein was upregulated in intima versus media layer and also in response to atherosclerosis. This overexpression and localization was confirmed in human aortas. In conclusion, molecular histology by MS Imaging identifies spatial organization of arterial tissue in response to atherosclerosis.

Inflammation in coronary artery disease

Coronary artery disease (CAD) is the leading cause of death in the United States. Although CAD was formerly considered a lipid accumulation-mediated disease, it has now been clearly shown to involve an ongoing inflammatory response. Advances in basic science research have established the crucial role of inflammation in mediating all stages of CAD. Today, there is convincing evidence that multiple interrelated immune mechanisms interact with metabolic risk factors to initiate, promote, and ultimately activate lesions in the coronary arteries. This review aims to provide current evidence pertaining to the role of inflammation in the pathogenesis of CAD and discusses the impact of inflammatory markers and their modification on clinical outcomes.

Platelet to lymphocyte ratio and neutrophil to lymphocyte ratio in patients with rheumatoid arthritis

OBJECTIVES

It has been well documented that the platelet to lymphocyte ratio (PLR) and the neutrophil to lymphocyte ratio (NLR) are associated with outcomes for patients with gastric cancer, non-small cell lung cancer and acute heart failure. Inflammation may be the hidden factor that explains the correlation between NLP, PLR, and these diseases. However, to date, the data concerning NLR, PLR, and its association with inflammation are lacking in patients with rheumatoid arthritis (RA), thus, our aim to discuss whether NLR and PLR are associated with RA.

METHODS

Patients with RA and healthy individuals were included according to the determined criteria, and laboratory indicators were measured.

RESULTS

PLR and NLR were significantly higher in RA patients compared with healthy controls (3.20±2.06 vs. 1.56±0.47, P<0.01; 192.85±101.78 vs. 103.49±28.68, P<0.01). When leukocytes, neutrophil percentage, neutrophil, lymphocyte, platelet, C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), and rheumatoid factor (RF) were considered as confounders (crude model), our results indicated that ESR and RF were correlated to RA. Of note, ESR, RF, and PLR were associated with RA after further adjustment based on crude model for PLR and NLR. Receiver operating characteristic (ROC) curves analysis showed that PLR values higher than >115.7 evaluated RA with a sensitivity of 82.5%, a specificity of 74.8% and area under the curve ( AUC ) of 0.847.

CONCLUSIONS

Our results suggest that PLR is associated with RA, and PLR may be an underlying indicator indicating the chronic subclinical inflammation in patients with RA.

Effects of thyroid hormone status on metabolic pathways of arachidonic acid in mice and humans: A targeted metabolomic approach

Symptoms of cardiovascular diseases are frequently found in patients with hypothyroidism and hyperthyroidism. However, it is unknown whether arachidonic acid metabolites, the potent mediators in cardiovascular system, are involved in cardiovascular disorders caused by hyperthyroidism and hypothyroidism. To answer this question, serum levels of arachidonic acid metabolites in human subjects with hypothyroidism, hyperthyroidism and mice with hypothyroidism or thyroid hormone treatment were determined by a mass spectrometry-based method. Over ten arachidonic acid metabolites belonging to three catalytic pathways: cyclooxygenases, lipoxygenases, and cytochrome P450, were quantified simultaneously and displayed characteristic profiles under different thyroid hormone status. The level of 20-hydroxyeicosatetraenoic acid, a cytochrome P450 metabolite, was positively correlated with thyroid hormone level and possibly contributed to the elevated blood pressured in hyperthyroidism. The increased prostanoid (PG) I2 and decreased PGE2 levels in hypothyroid patients might serve to alleviate atherosclerosis associated with dyslipidemia. The elevated level of thromboxane (TX) A2, as indicated by TXB2, in hyperthyroid patients and mice treated with thyroid hormone might bring about pulmonary hypertension frequently found in hyperthyroid patients. In conclusion, our prospective study revealed that arachidonic acid metabolites were differentially affected by thyroid hormone status. Certain metabolites may be involved in cardiovascular disorders associated with thyroid diseases.