Influence of Cardiometabolic Risk Factors on Platelet Function

Current Strategies to Guide the Antiplatelet Therapy in Acute Coronary Syndromes

The role of antiplatelet therapy in patients with acute coronary syndromes is a moving target with considerable novelty in the last few years. The pathophysiological basis of the treatment depends on platelet biology and physiology, and the interplay between these aspects and clinical practice must guide the physician in determining the best therapeutic options for patients with acute coronary syndromes. In the present narrative review, we discuss the latest novelties in the antiplatelet therapy of patients with acute coronary syndromes. We start with a description of platelet biology and the role of the main platelet signal pathways involved in platelet aggregation during an acute coronary syndrome. Then, we present the latest evidence on the evaluation of platelet function, focusing on the strengths and weaknesses of each platelet's function test. We continue our review by describing the role of aspirin and P2Y12 inhibitors in the treatment of acute coronary syndromes, critically appraising the available evidence from clinical trials, and providing current international guidelines and recommendations. Finally, we describe alternative therapeutic regimens to standard dual antiplatelet therapy, in particular for patients at high bleeding risk. The aim of our review is to give a comprehensive representation of current data on antiplatelet therapy in patients with acute coronary syndromes that could be useful both for clinicians and basic science researchers to be up-to-date on this complex topic.

Plasma growth factors maintain constitutive translation in platelets to regulate reactivity and thrombotic potential

ABSTRACT

Mechanisms of proteostasis in anucleate circulating platelets are unknown and may regulate platelet function. We investigated the hypothesis that plasma-borne growth factors/hormones (GFHs) maintain constitutive translation in circulating platelets to facilitate reactivity. Bio-orthogonal noncanonical amino acid tagging (BONCAT) coupled with liquid chromatography-tandem mass spectrometry analysis revealed constitutive translation of a broad-spectrum translatome in human platelets dependent upon plasma or GFH exposure, and in murine circulation. Freshly isolated platelets from plasma showed homeostatic activation of translation-initiation signaling pathways: phosphorylation of p38/ERK upstream kinases, essential intermediate MNK1/2, and effectors eIF4E/4E-BP1. Plasma starvation led to loss of pathway phosphorylation, but it was fully restored with 5-minute stimulation by plasma or GFHs. Cycloheximide or puromycin infusion suppressed ex vivo platelet GpIIb/IIIa activation and P-selectin exposure with low thrombin concentrations and low-to-saturating concentrations of adenosine 5'-diphosphate (ADP) or thromboxane analog but not convulxin. ADP-induced thromboxane generation was blunted by translation inhibition, and secondary-wave aggregation was inhibited in a thromboxane-dependent manner. Intravenously administered puromycin reduced injury-induced clot size in cremaster muscle arterioles, and delayed primary hemostasis after tail tip amputation but did not delay neither final hemostasis after subsequent rebleeds, nor final hemostasis after jugular vein puncture. In contrast, these mice were protected from injury-induced arterial thrombosis and thrombin-induced pulmonary thromboembolism (PE), and adoptive transfer of translation-inhibited platelets into untreated mice inhibited arterial thrombosis and PE. Thus, constitutive plasma GFH-driven translation regulates platelet G protein-coupled receptor reactivity to balance hemostasis and thrombotic potential.

Targeting Cysteine Oxidation in Thrombotic Disorders

Oxidative stress increases the risk for clinically significant thrombotic events, yet the mechanisms by which oxidants become prothrombotic are unclear. In this review, we provide an overview of cysteine reactivity and oxidation. We then highlight recent findings on cysteine oxidation events in oxidative stress-related thrombosis. Special emphasis is on the signaling pathway induced by a platelet membrane protein, CD36, in dyslipidemia, and by protein disulfide isomerase (PDI), a member of the thiol oxidoreductase family of proteins. Antioxidative and chemical biology approaches to target cysteine are discussed. Lastly, the knowledge gaps in the field are highlighted as they relate to understanding how oxidative cysteine modification might be targeted to limit thrombosis.

The role of platelets in non-alcoholic fatty liver disease: From pathophysiology to therapeutics

Platelets are one of the key mediators in thrombosis as well as in the progression of many diseases. An increase in platelet activation and a decrease in platelet count is associated with a plethora of liver diseases. In non-alcoholic fatty liver disease (NAFLD), platelets are highly activated and participate in the disease progression by enhancing the pro-thrombotic and pro-inflammatory state. Some altered platelet parameters such as mean platelet volume, plateletcrits, and platelet distribution width, aspartate transaminase to platelet ratio index, liver stiffness to platelet ratio and red cell distribution width to platelet ratio were found to be associated with NAFLD disease. Further, platelet contributes to the progression of cardiovascular complications in NAFLD is gaining the researcher's attention. An elevated mean platelet volume is known to enhance the risk of stroke, atherosclerosis, thrombosis, and myocardial infarction in NAFLD. Evidence also suggested that modulation in platelet function using aspirin, ticlopidine, and cilostazol help in controlling the NAFLD progression. Future research should focus on antiplatelet therapy as a treatment strategy that can control platelet activation in NAFLD as well as its cardiovascular risk. In the present review, we have detailed the role of platelets in NAFLD and its cardiovascular complications. We further aimed to highlight the growing need for antiplatelet therapy in NAFLD.

Crizanlizumab in sickle cell disease

Vaso-occlusion in sickle cell disease (SCD) leads to a myriad of manifestations driving morbidity and mortality in patients with SCD. Increased leucocyte adhesion and P-selectin expression on platelets and endothelial cells is an inciting event that leads to obstruction of microcirculation by adhesion with rigid sickled red blood cells. Crizanlizumab is a first-in-class monoclonal antibody that inhibits P-selectin and has been shown to decrease the frequency of vaso-occlusive pain crises in patients with SCD in clinical trials. The role of crizanlizumab in other manifestations of SCD still needs further investigation.

Platelets as Potential Non-Traditional Cardiovascular Risk Factor-Analysis Performed in Healthy Donors

Abnormal lipid profile, increased glucose level, and elevated body weight are traditional cardiometabolic risk factors; however, the role of platelets in the development of cardiovascular disease (CVD) is increasingly being highlighted. The aim of this study was to select platelet-related parameters (non-genetic molecular and routine laboratory measurements) that may be associated with increased cardiovascular risk among healthy populations. We evaluated the level of platelet indices, platelet-based inflammatory markers, platelet reactivity parameters, and platelet reactive oxygen species (ROS) generation in relation to selected cardiometabolic risk factors. We noted the association between total cholesterol and LDL cholesterol with platelet aggregation and platelet ROS generation. We found the relationship between triglycerides, glucose, and body mass index with the relatively new multi-inflammatory indices (MII-1 and MII-3). Moreover, we noticed that the mean platelet volume-to-lymphocyte ratio in healthy subjects is not a good source of information about platelets and inflammation. We also highlighted that platelet-to-HDL-cholesterol ratio may be a promising prognostic cardiometabolic indicator. The association between platelet-related (especially molecular) and cardiometabolic parameters requires further research. However, the goal of this study was to shed light on the consideration of platelets as a non-traditional cardiovascular risk factor and a crucial element in identifying individuals at high-risk of developing CVD in the future.

Insulin Resistance-Induced Platelet Hyperactivity and a Potential Biomarker Role of Platelet Parameters: A Narrative Review

Background

Insulin has an inhibitory effect on platelets; however, this is compromised in circumstances of Insulin Resistance (IR), leading to platelet hyperactivity. Platelet parameters such as mean platelet volume, platelet count, and platelet distribution width are simple and accessible potential biomarkers for the early diagnosis and prognosis of IR. Therefore, the aim of this review is to provide insight on the current status of knowledge regarding IR-induced platelet hyperactivation and the potential biomarker role of platelet parameters.

Methods

This narrative review included articles published in the English language. Searches were carried out at the electronic databases PubMed and Google Scholar. The search strategy was done by combining key words and related database-specific subject terms (Mesh terms) with the appropriate Boolean operators.

Conclusion

Increasing insulin sensitivity in insulin resistant patients would possibly cause substantial reduction in platelet activation, which in turn reduce complications related with platelet hyperactivation. The standard methods to measure IR are not frequently employed in clinical practice due to their expensiveness and complexity. Thus, early detection of IR using a simple and more widely available biomarkers such as mean platelet volume, platelet count and platelet distribution width would be beneficial. Particularly in developing countries where resource scarcity is a major constraint of the health sector, utilizing such easy and affordable biomarkers may have a crucial role.

Neuroprotection from protein misfolding in cerebral hypoperfusion concurrent with metabolic syndrome. A translational perspective

Based on clinical and experimental evidence, metabolic syndrome (MetS) and type 2 diabetes (T2D) are considered risk factors for chronic cerebral hypoperfusion (CCH) and neurodegeneration. Scientific evidence suggests that protein misfolding is a potential mechanism that explains how CCH can lead to either Alzheimer's disease (AD) or vascular cognitive impairment and dementia (VCID). Over the last decade, there has been a significant increase in the number of experimental studies regarding this issue. Using several animal paradigms and different markers of CCH, scientists have discussed the extent to which MetSor T2D causes a decrease in cerebral blood flow (CBF). In addition, different models of CCH have explored how long-term reductions in oxygen and energy supply can trigger AD or VCID via protein misfolding and aggregation. Research that combines two or three animal models could broaden knowledge of the links between these pathological conditions. Recent experimental studies suggest novel neuroprotective properties of protein-remodeling factors. In this review, we present a summarized updated revision of preclinical findings, discussing clinical implications and proposing new experimental approaches from a translational perspective. We are confident that research studies, both clinical and experimental, may find new diagnostic and therapeutic tools to prevent neurodegeneration associated with MetS, diabetes, and any other chronic non-communicable disease (NCD) associated with diet and lifestyle risk factors.

Impact of Physical Exercise on Platelets: Focus on Its Effects in Metabolic Chronic Diseases

Chronic disorders are strongly linked to cardiovascular (CV) diseases, and it is unanimously accepted that regular exercise training is a key tool to improving CV risk factors, including diabetes, dyslipidemia, and obesity. Increased oxidative stress due to an imbalance between reactive oxygen species production and their scavenging by endogenous antioxidant capacity is the common ground among these metabolic disorders, and each of them affects platelet function. However, the correction of hyperglycemia in diabetes and lipid profile in dyslipidemia as well as the lowering of body weight in obesity all correlate with amelioration of platelet function. Habitual physical exercise triggers important mechanisms related to the exercise benefits for health improvement and protects against CV events. Platelets play an important role in many physiological and pathophysiological processes, including the development of arterial thrombosis, and physical (in)activity has been shown to interfere with platelet function. Although data reported by studies carried out on this topic show discrepancies, the current knowledge on platelet function affected by exercise mainly depends on the type of applied exercise intensity and whether acute or habitual, strenuous or moderate, thus suggesting that physical activity and exercise intensity may interfere with platelet function differently. Thus, this review is designed to cover the aspects of the relationship between physical exercise and vascular benefits, with an emphasis on the modulation of platelet function, especially in some metabolic diseases.

Endothelial dysfunction, platelet hyperactivity, hypertension, and the metabolic syndrome: molecular insights and combating strategies

Metabolic syndrome (MetS) is a multifaceted condition that increases the possibility of developing atherosclerotic cardiovascular disease. MetS includes obesity, hypertension, dyslipidemia, hyperglycemia, endothelial dysfunction, and platelet hyperactivity. There is a concerning rise in the occurrence and frequency of MetS globally. The rising incidence and severity of MetS need a proactive, multipronged strategy for identifying and treating those affected. For many MetS patients, achieving recommended goals for healthy fat intake, blood pressure control, and blood glucose management may require a combination of medicine therapy, lifestyles, nutraceuticals, and others. However, it is essential to note that lifestyle modification should be the first-line therapy for MetS. In addition, MetS requires pharmacological, nutraceutical, or other interventions. This review aimed to bring together the etiology, molecular mechanisms, and dietary strategies to combat hypertension, endothelial dysfunction, and platelet dysfunction in individuals with MetS.

Association of ADP-Induced Whole-Blood Platelet Aggregation with Serum Low-Density Lipoprotein Cholesterol in Patients with Coronary Artery Disease When Receiving Maintenance Ticagrelor-Based Dual Antiplatelet Therapy

The degree of platelet inhibition in patients undergoing dual antiplatelet therapy (DAPT) affects cardiovascular outcomes after acute coronary syndromes (ACS) and/or percutaneous coronary intervention. Our aim was to search for correlates of residual ex vivo platelet reactivity and circulating soluble P-selectin (sP-selectin), an index of in vivo platelet activation, in patients being treated by DAPT with ticagrelor. Adenosine diphosphate (ADP)-induced platelet aggregability (by multiple electrode aggregometry) and plasma sP-selectin were estimated in 62 stable post-ACS subjects (46 men and 16 women; mean age: 64 ± 10 years; 30 with type 2 diabetes (T2DM)) undergoing maintenance DAPT with ticagrelor and aspirin. These patients did not exhibit heart failure or other relevant coexistent diseases except for properly controlled T2DM, mild renal insufficiency, and hypertension. We also assessed this in 64 subjects on clopidogrel-based DAPT matched for age, sex, and T2DM status. ADP-induced platelet aggregation was below the optimal levels (190-460 arbitrary units (AU) * min) in most patients receiving ticagrelor-based DAPT, especially in those with below-median (<1.9 mmol/L) serum concentrations of low-density lipoprotein cholesterol (LDL-c) (128 ± 61 vs. 167 ± 73 AU * min for below-median and above-median LDL-c, respectively, p = 0.025). In contrast, platelet reactivity did not differ by LDL-c on clopidogrel-based DAPT (246 ± 101 vs. 268 ± 108 AU * min for below-median and above-median LDL-c, respectively, p > 0.4). Plasma sP-selectin was found to be unrelated to serum LDL-c when receiving DAPT with ticagrelor (p > 0.4) or clopidogrel (p > 0.8). In conclusion, our preliminary observational study suggests the association of lower residual ex vivo platelet aggregability with better LDL-c control in patients undergoing ticagrelor-based maintenance DAPT, which does not appear to be reflected by plasma sP-selectin. Whether the serum LDL-c level should be considered among the factors affecting the degree of platelet inhibition for those treated with ticagrelor-based DAPT needs to be investigated in larger studies.

LncRNAs associated with oxidative stress in diabetic wound healing: Regulatory mechanisms and application prospects

Diabetes is a group of chronic diseases with blood glucose imbalance, and long-term hyperglycaemia causes sustained damage to various organs of the body, resulting in vascular lesions, neuropathy and impaired wound healing. Diabetic wound formation involves a variety of complex mechanisms, and they are characterized by a persistent chronic inflammatory response, degradation of angiogenesis and imbalance of extracellular matrix regulation, all of which are related to oxidative stress. Additionally, repair and healing of diabetic wounds require the participation of a variety of cells, cytokines, genes, and other factors, which together constitute a complex biological regulatory network. Recent studies have shown that long noncoding RNAs (lncRNAs) can be involved in the regulation of several key biological pathways and cellular functions demonstrating their critical role in diabetic wound healing. LncRNAs are a major family of RNAs with limited or no protein-coding function. Numerous studies have recently reported a strong link between oxidative stress and lncRNAs. Given that both lncRNAs and oxidative stress have been identified as potential drivers of diabetic wound healing, their link in diabetic wound healing can be inferred. However, the specific mechanism of oxidative stress related to lncRNAs in diabetic wound healing is still unclear, and elucidating the functions of lncRNAs in these processes remains a major challenge. This article reviews the mechanisms of lncRNAs related to oxidative stress in several stages of diabetic wound healing and discusses diagnostic and treatment potential of lncRNAs to treat diabetic wounds by improving oxidative stress, as well as the challenges of using lncRNAs for this purpose. It is hoped that these results will provide new targets and strategies for the diagnosis and treatment of impaired wound healing in diabetic patients.

Platelets and Cardioprotection: The Role of Nitric Oxide and Carbon Oxide

Nitric oxide (NO) and carbon monoxide (CO) represent a pair of biologically active gases with an increasingly well-defined range of effects on circulating platelets. These gases interact with platelets and cells in the vessels and heart and exert fundamentally similar biological effects, albeit through different mechanisms and with some peculiarity. Within the cardiovascular system, for example, the gases are predominantly vasodilators and exert antiaggregatory effects, and are protective against damage in myocardial ischemia-reperfusion injury. Indeed, NO is an important vasodilator acting on vascular smooth muscle and is able to inhibit platelet activation. NO reacts with superoxide anion (O₂(^-•)) to form peroxynitrite (ONOO(^-)), a nitrosating agent capable of inducing oxidative/nitrative signaling and stress both at cardiovascular, platelet, and plasma levels. CO reduces platelet reactivity, therefore it is an anticoagulant, but it also has some cardioprotective and procoagulant properties. This review article summarizes current knowledge on the platelets and roles of gas mediators (NO, and CO) in cardioprotection. In particular, we aim to examine the link and interactions between platelets, NO, and CO and cardioprotective pathways.

In Vitro Exposure to Glucose Alters the Expression of Phosphorylated Proteins in Platelets

Diabetes mellitus (DM) is a pro-thrombotic state that can potentially cause serious cardiovascular complications. Platelet hyperactivation plays an important role in these pathological processes, however there is little or no information on the effect of hyperglycemia on platelet proteins. The aim of this study was to identify the molecular targets associated with platelet reactivity under hyperglycemia. Towards this goal, we examined the effects of the exposure of platelets to 1 and 2 h glucose (300 mg/dL) and control (vehicle and osmolality control using mannitol) on platelet proteins (n = 4 samples per group) using two-dimensional fluorescence difference gel electrophoresis (2D-DIGE) combined with MALDI-TOF/TOF tandem mass spectrometry. Two-hour exposure to glucose significantly up-regulated the expression of ATP synthase subunit beta, filamin-A, and L-lactate dehydrogenase A chain in platelets. Pro-Q Diamond staining confirmed the effect of 2 h glucose on vinculin, heat shock protein HSP 90-alpha, filamin-A, and fructose-bisphosphate aldolase A (platelet phosphorylated proteins). The identified proteins are involved in various cellular processes and functions and possibly in platelet reactivity under hyperglycemic conditions.

Efficient megakaryopoiesis and platelet production require phospholipid remodeling and PUFA uptake through CD36

Lipids contribute to hematopoiesis and membrane properties and dynamics, however, little is known about the role of lipids in megakaryopoiesis. Here, a lipidomic analysis of megakaryocyte progenitors, megakaryocytes, and platelets revealed a unique lipidome progressively enriched in polyunsaturated fatty acid (PUFA)-containing phospholipids. In vitro, inhibition of both exogenous fatty acid functionalization and uptake and de novo lipogenesis impaired megakaryocyte differentiation and proplatelet production. In vivo, mice on a high saturated fatty acid diet had significantly lower platelet counts, which was prevented by eating a PUFA-enriched diet. Fatty acid uptake was largely dependent on CD36, and its deletion in mice resulted in thrombocytopenia. Moreover, patients with a CD36 loss-of-function mutation exhibited thrombocytopenia and increased bleeding. Our results suggest that fatty acid uptake and regulation is essential for megakaryocyte maturation and platelet production, and that changes in dietary fatty acids may be a novel and viable target to modulate platelet counts.

The Link between NAFLD and Metabolic Syndrome

Metabolic syndrome (MetS) is characterized by an association of cardiovascular and diabetes mellitus type 2 risk factors. Although the definition of MetS slightly differs depending on the society that described it, its central diagnostic criteria include impaired fasting glucose, low HDL-cholesterol, elevated triglycerides levels and high blood pressure. Insulin resistance (IR) is believed to be the main cause of MetS and is connected to the level of visceral or intra-abdominal adipose tissue, which could be assessed either by calculating body mass index or by measuring waist circumference. Most recent studies revealed that IR may also be present in non-obese patients, and considered visceral adiposity to be the main effector of MetS' pathology. Visceral adiposity is strongly linked with hepatic fatty infiltration also known as non-alcoholic fatty liver disease (NAFLD), therefore, the level of fatty acids in the hepatic parenchyma is indirectly linked with MetS, being both a cause and a consequence of this syndrome. Taking into consideration the present pandemic of obesity and its tendency to drift towards a progressively earlier onset due to the Western lifestyle, it leads to an increased NAFLD incidence. Novel therapeutic resources are lifestyle intervention with physical activity, Mediterranean diet, or therapeutic surgical respective metabolic and bariatric surgery or drugs such as SGLT-2i, GLP-1 Ra or vitamin E. NAFLD early diagnosis is important due to its easily available diagnostic tools such as non-invasive tools: clinical and laboratory variables (serum biomarkers): AST to platelet ratio index, fibrosis-4, NAFLD Fibrosis Score, BARD Score, fibro test, enhanced liver fibrosis; imaging-based biomarkers: Controlled attenuation parameter, magnetic resonance imaging proton-density fat fraction, transient elastography (TE) or vibration controlled TE, acoustic radiation force impulse imaging, shear wave elastography, magnetic resonance elastography; and the possibility to prevent its complications, respectively, fibrosis, hepato-cellular carcinoma or liver cirrhosis which can develop into end-stage liver disease.

Hematological parameters and early-onset coronary artery disease: a retrospective case-control study based on 3366 participants

Background

Thrombosis and inflammation are crucial elements in the pathogenesis of cardiovascular disease. Hematological parameters elucidate information involving the inflammatory and blood coagulation processes.

Objectives

The current study explored the association of hematological parameters with EOCAD to identify specific risk factors.

Design

A single-center retrospective case-control study was conducted with 1693 coronary artery disease patients and 1693 controls.

Methods

Hematological parameters were examined through an automated analyzer.

Results

The basophil percentage was significantly reduced in EOCAD (0.43 ± 0.26, p < 0.001) and MI (0.33 ± 0.24, p < 0.001) groups compared with controls (0.54 ± 0.28). The eosinophil percentage was also significantly lower in EOCAD (2.21 ± 1.71, p < 0.001) and MI (1.71 ± 2.44, p < 0.001) groups compared with controls (2.41 ± 1.75). The lymphocyte percentage in patients of EOCAD and MI and controls was 31.65 ± 7.93, 25.48 ± 9.43, and 34.82 ± 7.28, respectively. A significant difference was observed among the groups (p < 0.001). Except for the mean corpuscular hemoglobin (MCH), other red blood cell (RBC) parameters significantly differed between EOCAD patients and controls. The red blood cell distribution width (RDW), hematocrit (HCT), RBC count, mean corpuscular hemoglobin concentration (MCHC), mean corpuscular volume (MCV), and hemoglobin level were associated with EOCAD prevalence after adjusting for baseline differences. Platelet volume distribution width (PDW) also correlated with EOCAD prevalence (OR_adjust = 1.087, 95% CI: 1.044-1.131).

Conclusions

Hematological parameters are closely associated with EOCAD. Moreover, leukocyte parameters correlated with the presence and severity of the disease. In addition, erythrocyte parameters were associated with the disease presence but not with the disease severity. Among the platelet parameters, only PDW was related to the disease presence.

Dolutegravir potentiates platelet activation by a calcium-dependent, ionophore-like mechanism

Dolutegravir is a highly potent HIV integrase strand transfer inhibitor that is recommended for first-line anti-retroviral treatment in all major treatment guidelines. A recent study has shown that people taking this class of anti-retroviral treatment have a substantially higher risk of early-onset cardiovascular disease, a condition shown previously to be associated with increased platelet reactivity. To date, few studies have explored the effects of dolutegravir on platelet activation. Accordingly, the current study was undertaken with the primary objective of investigating the effects of dolutegravir on the reactivity of human platelets in vitro. Platelet-rich plasma, isolated platelets, or buffy coat cell suspensions prepared from the blood of healthy adults were treated with dolutegravir (2.5-10 µg/ml), followed by activation with adenosine 5'-diphosphate (ADP), thrombin, or a thromboxane A₂ receptor agonist U46619. Expression of platelet CD62P (P-selectin), formation of heterotypic neutrophil:platelet aggregates, and calcium (Ca²⁺) fluxes were measured using flow cytometry and fluorescence spectrometry, respectively. Dolutegravir caused dose-related potentiation of ADP-, thrombin- and U46619-activated expression of CD62P by platelets, as well as a significant increases in formation of neutrophil:platelet aggregates. These effects were paralleled by a spontaneous, receptor-independent elevation in cytosolic Ca²⁺ that appears to underpin the mechanism by which the antiretroviral agent augments the responsiveness of these cells to ADP, thrombin and U46619. The most likely mechanism of dolutegravir-mediated increases in platelet cytosolic Ca²⁺ relates to a combination of lipophilicity and divalent/trivalent metal-binding and/or chelating properties of the anti-retroviral agent. These properties are likely to confer ionophore-type activities on dolutegravir that would promote movement of Ca²⁺ across the plasma membrane, delivering the cation to the cytosol where it would augment Ca²⁺-dependent intracellular signaling mechanisms. These effects of dolutegravir may lead to hyper-activation of platelets which, if operative in vivo, may contribute to an increased risk for cardiometabolic co-morbidities.

Curcumin nanoemulsion counteracts hepatic and cardiac complications associated with high-fat/high-fructose diet in rats

The relationship between the incidence of cardiovascular abnormalities and non-alcoholic fatty liver disease (NAFLD) has long been postulated. Curcumin (CUR) is a potential anti-atherosclerotic agent but its poor water solubility hinders its pharmacological use. Therefore, the present study aimed to investigate the effect of formulation of CUR nanoemulsion prepared using the spontaneous emulsification technique on high fat high fructose (HFHF)-induced hepatic and cardiac complications. Fifty Wistar rats were divided into five groups. CUR nanoemulsion at doses of 5 and 10 mg/kg and conventional powdered CUR at a dose of 50 mg/kg were orally administered daily to rats for two weeks, and compared with normal control and HFHF control. Results revealed that the high dose level of CUR nanoemulsion was superior to conventional CUR in ameliorating the HFHF-induced insulin resistance status and hyperlipidemia, with beneficial impact on rats' recorded electrocardiogram (ECG), serum aspartate aminotransferase (ALT) and alanine aminotransferase (AST) levels, leptin, adiponectin, creatine phosphokinase, lactate dehydrogenase and cardiac troponin-I. In addition, hepatic and cardiac oxidative and nitrosative stresses, oxidative DNA damage and disrupted cellular energy statuses were counteracted. Results were also confirmed by histopathological examination. PRACTICAL APPLICATIONS: The use of curcumin nanoemulsion could be beneficial in combating hepatic and cardiac complications resulting from HFHF diets.

Platelet Redox Imbalance in Hypercholesterolemia: A Big Problem for a Small Cell

The imbalance between reactive oxygen species (ROS) synthesis and their scavenging by anti-oxidant defences is the common soil of many disorders, including hypercholesterolemia. Platelets, the smallest blood cells, are deeply involved in the pathophysiology of occlusive arterial thrombi associated with myocardial infarction and stroke. A great deal of evidence shows that both increased intraplatelet ROS synthesis and impaired ROS neutralization are implicated in the thrombotic process. Hypercholesterolemia is recognized as cause of atherosclerosis, cerebro- and cardiovascular disease, and, closely related to this, is the widespread acceptance that it strongly contributes to platelet hyperreactivity via direct oxidized LDL (oxLDL)-platelet membrane interaction via scavenger receptors such as CD36 and signaling pathways including Src family kinases (SFK), mitogen-activated protein kinases (MAPK), and nicotinamide adenine dinucleotide phosphate (NADPH) oxidase. In turn, activated platelets contribute to oxLDL generation, which ends up propagating platelet activation and thrombus formation through a mechanism mediated by oxidative stress. When evaluating the effect of lipid-lowering therapies on thrombogenesis, a large body of evidence shows that the effects of statins and proprotein convertase subtilisin/kexin type 9 inhibitors are not limited to the reduction of LDL-C but also to the down-regulation of platelet reactivity mainly by mechanisms sensitive to intracellular redox balance. In this review, we will focus on the role of oxidative stress-related mechanisms as a cause of platelet hyperreactivity and the pathophysiological link of the pleiotropism of lipid-lowering agents to the beneficial effects on platelet function.

The combination of danhong injection plus tissue plasminogen activator ameliorates mouse tail thrombosis-induced by κ-carrageenan

BACKGROUND

After thrombosis, t-PA thrombolysis is the first choice, but the use of t-PA can easily lead to hemorrhagic injury and neurotoxicity. The combination of Danhong injection (DHI) and tissue plasminogen activator (t-PA) therapy may be a new strategy to find high-efficiency anti-thrombosis and low bleeding risk. However, nothing is about the effect of DHI plus t-PA on platelet activation.

PURPOSE

The present research was to explore the optimal dose of DHI and t-PA in vivo and mechanisms involved with the treatment of combining DHI and t-PA for thrombotic disease and determined whether DHI plus t-PA affects thrombotic processes related to platelet activation.

METHODS

Mice were induced by administering κ-carrageenan intraperitoneally, the ratio of different doses of DHI and t-PA in vivo, and the optimal dose effects on platelet aggregation, platelet adhesion, thrombosis formation, and platelet activation were determined. The effects of the αIIbβ3 signaling pathway were analyzed in mice.

RESULTS

In vitro, DHI (62% v/v), t-PA (1 mg/ml), and DHI + t-PA (62% v/v + 1 mg/ml) decreased rat platelet aggregation and adhesion, with a stronger effect from the combination as compared to t-PA monotherapy. In vivo, injections of κ-carrageenan were used to induce BALB/c mice. The optimal dose of DHI, t-PA, and DHI + t-PA is 12 ml/kg, 10 mg/kg, and 12 ml/kg + 7.5 mg/kg. The administration of DHI (12 ml/kg), t-PA (10 mg/kg), and DHI + t-PA (12 ml/kg + 7.5 mg/kg) decreased thrombi in mouse tissue vessels. Furthermore, the reduction of thrombosis formation by DHI, t-PA, and DHI + t-PA was related to lower collagen deposition, and lowered expressions of collagen I, matrix metalloproteinase 2 (MMP-2), and metalloproteinase 9 (MMP-9) in mouse tails, with increased efficacy in combination as compared to t-PA alone. The anti-thrombosis actions of DHI, t-PA, and their combination regulated the expression of CD41, purinergic receptor (P2Y₁₂), guanine nucleotide-binding protein G (q) subunit alpha (GNAQ), phosphatidylinositol phospholipase c beta (PLCβ), Ras-related protein 1 (Rap1), RIAM, talin1, fibrinogen alpha chain (FG), kindlin-3, and RAS guany1-releasing protein 1 (RasGRP1).

CONCLUSIONS

Based on expression, the mechanism responsible for thrombosis may be attributed to platelet activation via the αIIbβ3 signaling pathway. Combination therapy with DHI and t-PA exerted potent thrombolytic effects. Thus, our data can be used as a foundation for further clinical studies examining the efficacy of traditional Chinese medicines for the treatment of thrombosis.

The Role of Platelets in Diabetic Kidney Disease

Diabetic kidney disease (DKD) is among the most common microvascular complications in patients with diabetes, and it currently accounts for the majority of end-stage kidney disease cases worldwide. The pathogenesis of DKD is complex and multifactorial, including systemic and intra-renal inflammatory and coagulation processes. Activated platelets play a pivotal role in inflammation, coagulation, and fibrosis. Mounting evidence shows that platelets play a role in the pathogenesis and progression of DKD. The potentially beneficial effects of antiplatelet agents in preventing progression of DKD has been studied in animal models and clinical trials. This review summarizes the current knowledge on the role of platelets in DKD, including the potential therapeutic effects of antiplatelet therapies.

The Roles of Platelet-Activating Factor and Magnesium in Pathophysiology of Hypertension, Atherogenesis, Cardiovascular Disease, Stroke and Aging

Hypertension and atherosclerosis are debilitating diseases that affect millions each year. Long-term consequences include but are not limited to stroke, myocardial infarction, and kidney failure. Platelet-activating factor (PAF) is a proinflammatory mediator synthesized from a subclass of phosphatidylcholines that increases platelet activation, leukocyte adhesion, infiltration of macrophages, and intracellular lipid accumulation, thereby contributing to atherosclerosis. Magnesium, a key micronutrient and free radical scavenger, is a water-soluble mineral that regulates peripheral vasodilation and calcium, phosphate, and hydroxyapatite homeostasis. Magnesium’s antihypertensive ability stems from its role as a natural calcium antagonist and promoter of vasodilatory mediators, such as nitric oxide. Platelet-activating factor and magnesium share an inverse relationship, and elevated magnesium levels have been shown to have protective effects against plaque formation as well as antihypertensive and antiarrhythmic effects, all of which allow for healthier aging. The purpose of this literature review is to investigate the role of platelet-activating factor and magnesium in the pathophysiology of hypertension, atherosclerosis, cardiovascular disease, stroke, and aging. Since the pathophysiology of the platelet-activating factor biomolecule is underexplored, further research studies are warranted in order to navigate the putative signaling pathways involved in the cardioprotective effects of dietary magnesium as a natural anti-PAF agent.

Impairment of Anti-Aggregatory Responses to Nitric Oxide and Prostacyclin: Mechanisms and Clinical Implications in Cardiovascular Disease

The propensity towards platelet-rich thrombus formation increases substantially during normal ageing, and this trend is mediated by decreases in platelet responsiveness to the anti-aggregatory nitric oxide (NO) and prostacyclin (PGI₂) pathways. The impairment of soluble guanylate cyclase and adenylate cyclase-based signalling that is associated with oxidative stress represents the major mechanism of this loss of anti-aggregatory reactivity. Platelet desensitization to these autacoids represents an adverse prognostic marker in patients with ischemic heart disease and may contribute to increased thrombo-embolic risk in patients with heart failure. Patients with platelet resistance to PGI₂ also are unresponsive to ADP receptor antagonist therapy. Apart from ischemia, diabetes and aortic valve disease are also associated with impaired anti-aggregatory homeostasis. This review examines the association of impaired platelet cyclic nucleotide (i.e., cGMP and cAMP) signalling with the emerging evidence of thromboembolic risk in cardiovascular diseases, and discusses the potential therapeutic strategies targeting this abnormality.

Comparison of Immature Platelet Fraction and Factors Associated with Inflammation, Thrombosis and Platelet Reactivity Between Left and Right Atria in Patients with Atrial Fibrillation

Background

Recent trials found poor temporal relationship between atrial fibrillation (AF) episodes and strokes. Thus, stroke in AF patients probably involves more mechanisms than cardiac embolism. We compared factors of inflammation, thrombosis and platelet reactivity between left (LA) and right atria (RA) and femoral vein (FV) in patients with AF.

Methods

Blood samples were collected from patients undergoing AF-ablation from the FV, RA and LA for neutrophil to lymphocyte ratio (NLR), immature platelet fraction (IPF) and count (IPC), CD40 ligand, P-selectin and E-Selectin. IPF was measured by an autoanalyzer; CD40 ligand, P-selectin, and E-Selectin were measured by ELISA and NLR was calculated from complete blood counts.

Results

Sixty-seven patients were included (age 65±10y, 63% male, CHA₂DS₂-VASc score 2.8±1.8, LA volume index 40±24 mL/m², 63% paroxysmal AF). There was no difference between FV, RA and LA regarding NLR and CD40 ligand. Factors associated with platelets activity: P-selectin, IPC and IPF% were higher in RA vs LA (60.3 IQR 49.0-76.4 ng/ml vs. 59.3 IQR 49.0-74.7, respectively, p=0.03 for P-selectin, 7.5 IQR 5.2-10 103/μL vs. 7.1 IQR 5-9.8, p<0.01 for IPC, and 3.6 IQR 2.7-5.0 % vs. 3.6 IQR 2.6-4.8, p<0.01 for IPF%). Similar trends were for E-selectin (41.2 IQR 31.1-51.2 ng/mL vs. 38.7 IQR 27.9-50.4 p=0.09). Similar significant differences were found in patients with CHA₂DS₂-VASC≥2 but not in patients with low score.

Conclusions

Patients with AF, especially those with CHA₂DS₂-VASc≥2, have higher markers of thrombogenicity in RA compared to LA. There was no difference in inflammatory properties between the atria.

Real life behaviour of direct oral anticoagulants in patients with nonvalvular atrial fibrillation and morbid obesity

Atrial fibrillation (AF) is the most prevalent arrhythmia worldwide and the main cause of anticoagulation, being direct oral anticoagulants (DOAC) increasingly used in this context. On the other hand, obesity is a known risk thromboembolic factor. In the clinical trials that led to the approval of DOAC for ischemic stroke prevention, patients with morbid obesity were underrepresented. The International Society of Thrombosis and Haemostasis suggests not using these drugs in morbid obese patients. Thus, the primary objectives of this study were to analyse the rates of mortality, thrombotic and haemorrhagic events in patients with morbid obesity. As secondary objectives, factors statistically associated with these events were analysed. Methods: multicentre retrospective study that included patients diagnosed with AF on treatment with DOAC from January 2013 to December 2016. The subgroup of patients with morbid obesity (BMI > 40 and / or weight > 120 kg) was analysed. Mean follow-up was 1.7 years. Results: Amongst 2,492 patients included in the study, 135 patients had morbid obesity (mean age was 71 ± 11 years). The mean scores of the CHA2DS2-VASc and HAS-BLED risk scales were 3.7 ± 1.6 and 2.2 ± 0.9, respectively. Neither differences were found regarding mortality (5.2 vs 6/100 patient-years, p = 0.662), ischemic stroke (0.8 vs 1.9/100 patient-years, p = 0.261) and major bleeding rates (3 vs 3.1/100 patient-years, p = 0.983) between morbidly obese population and general population. Nor was there an association found between the degree of obesity and any of the events studied. Conclusion: DOAC are safe and effective in morbidly obese patients.

Ultrastructural Study of Platelet Behavior and Interrelationship in Sprouting and Intussusceptive Angiogenesis during Arterial Intimal Thickening Formation

Platelets in atherosclerosis, bypass stenosis, and restenosis have been extensively assessed. However, a sequential ultrastructural study of platelets in angiogenesis during the early phases of these lesions has received less attention. Our objective was the study of platelets in angiogenesis and vessel regression during intimal thickening (IT) formation, a precursor process of these occlusive vascular diseases. For this purpose, we used an experimental model of rat occluded arteries and procedures for ultrastructural observation. The results show (a) the absence of platelet adhesion in the de-endothelialized occluded arterial segment isolated from the circulation, (b) that intraarterial myriad platelets contributed from neovessels originated by sprouting angiogenesis from the periarterial microvasculature, (c) the association of platelets with blood components (fibrin, neutrophils, macrophages, and eosinophils) and non-polarized endothelial cells (ECs) forming aggregates (spheroids) in the arterial lumen, (d) the establishment of peg-and-socket junctions between platelets and polarized Ecs during intussusceptive angiogenesis originated from the EC aggregates, with the initial formation of IT, and (e) the aggregation of platelets in regressing neovessels (‘transitory paracrine organoid’) and IT increases. In conclusion, in sprouting and intussusceptive angiogenesis and vessel regression during IT formation, we contribute sequential ultrastructural findings on platelet behavior and relationships, which can be the basis for further studies using other procedures.

More frequent olive oil intake is associated with reduced platelet activation in obesity

BACKGROUND AND AIMS

Obesity is an independent risk factor for atherosclerotic cardiovascular disease (CVD), and platelet hyperactivation in obesity may contribute to this association. Olive oil consumption is associated with lower cardiovascular disease (CVD) risk in the general population. However, little is known for individuals with obesity. We investigated whether olive oil intake is associated with platelet activation in obesity.

METHODS AND RESULTS

We assessed platelet activation (surface P-selectin expression) with and without thrombin exposure and diet composition in 63 patients with severe obesity. Among 63 subjects with obesity, the mean age was 32.2 ± 8.0 years and BMI 44.1 ± 8.5 kg/m². Olive oil intake was stratified into <1 time/week (n = 21), 1-3 times/week (n = 18), ≥4 times/week (n = 24). Strata did not differ by age, BMI or platelet count. Unstimulated P-selectin expression did not differ by olive oil consumption. Subjects with more frequent olive oil intake exhibited lower P-selectin expression on submaximal thrombin exposure.

CONCLUSIONS

More frequent olive oil intake is associated with reduced thrombin-induced platelet activation in obesity.

Ergothioneine supplementation in people with metabolic syndrome (ErgMS): protocol for a randomised, double-blind, placebo-controlled pilot study

Background

Ergothioneine is a naturally occurring metabolite of histidine found in many foods and in high amounts in mushrooms. In vivo, ergothioneine acts as an antioxidant and is widely distributed in most mammalian tissues. While ergothioneine is sold as a dietary supplement for its antioxidant and anti-inflammatory properties, to date there are no published intervention trials examining its health benefits in humans. The aim of this work was to develop a study protocol for a pilot interventional trial that will establish the primary and secondary outcomes, and the power required, for a definitive randomised controlled trial to test the hypothesis that ergothioneine supplementation is beneficial for people with metabolic syndrome.

Methods

We have designed the ErgMS study as a single-centre, randomised, double-blind, placebo-controlled, 3-arm parallel, pilot intervention trial, which aims to supplement participants with either placebo, 5 or 30 mg/day ergothioneine for 12 weeks. Measurements of metabolic syndrome risk factors, serum markers of oxidative stress (lipid peroxidation), inflammation, blood platelet function and liver function will take place at baseline, and after 6 weeks and 12 weeks of supplementation. In addition, we will examine if there are any changes in the serum metabolome in response to ergothioneine supplementation. Linear regression and two-way ANOVA will be utilised to analyse the association between ergothioneine and measured variables.

Discussion

The ErgMS study will be the first study to address the question does ergothioneine supplementation have health benefits for people with metabolic syndrome. Study results will provide preliminary data as to which dose may improve inflammatory markers in adults with metabolic syndrome and will inform dose and primary outcome selection for a definitive randomised controlled trial.

Trial registration

ISRCTN, ISRCTN25890011 Registered February 10^th, 2021

Supplementary Information

The online version contains supplementary material available at 10.1186/s40814-021-00929-6.

Mean Platelet Volume is Associated with Pancreatic β-Cell Dysfunction in Nondiabetic Patients with Coronary Artery Disease

Purpose

Mean platelet volume (MPV) is an indicator of platelet activation. Pancreatic β-cell dysfunction is one of the fundamental defects contributing to the development of type 2 diabetes. The aim of this study was to assess the relationship between β-cell dysfunction and MPV in nondiabetic patients with coronary artery disease (CAD).

Patients and Methods

A total of 1143 consecutive nondiabetic patients (874 males and 269 females; mean age 60.0±10.3 years) with CAD were recruited for this analysis. All patients were individuals who underwent coronary angiography with a suspicion of CAD. Homeostatic model assessment 2 (HOMA2) of β-cell function (HOMA2-β%) was performed, and β-cell dysfunction was defined by a HOMA2-β% in the lowest quartile.

Results

MPV was significantly higher in CAD patients with β-cell dysfunction than in controls [(10.6±1.0)fl vs (10.0±1.0)fl, P=0.011]. According to the multiple regression model, pancreatic β-cell dysfunction was independently associated with MPV (β=0.210, P=0.006) and age (β=0.008, P=0.028).

Conclusion

MPV was significantly elevated in nondiabetic CAD patients with β-cell dysfunction compared to patients with normal β-cell function.

Inflammatory Mediators of Platelet Activation: Focus on Atherosclerosis and COVID-19

Background: Atherosclerotic cardiovascular diseases are characterized by a dysregulated inflammatory and thrombotic state, leading to devastating complications with increased morbidity and mortality rates. Summary: In this review article, we present the available evidence regarding the impact of inflammation on platelet activation in atherosclerosis. Key messages: In the context of a dysfunctional vascular endothelium, structural alterations by means of endothelial glycocalyx thinning or functional modifications through impaired NO bioavailability and increased levels of von Willebrand factor result in platelet activation. Moreover, neutrophil-derived mediators, as well as neutrophil extracellular traps formation, have been implicated in the process of platelet activation and platelet-leukocyte aggregation. The role of pro-inflammatory cytokines is also critical since their receptors are also situated in platelets while TNF-α has also been found to induce inflammatory, metabolic, and bone marrow changes. Additionally, important progress has been made towards novel concepts of the interaction between inflammation and platelet activation, such as the toll-like receptors, myeloperoxidase, and platelet factor-4. The accumulating evidence is especially important in the era of the coronavirus disease-19 pandemic, characterized by an excessive inflammatory burden leading to thrombotic complications, partially mediated by platelet activation. Lastly, recent advances in anti-inflammatory therapies point towards an anti-thrombotic effect secondary to diminished platelet activation.

The platelet to high density lipoprotein -cholesterol ratio is a valid biomarker of nascent metabolic syndrome

AIMS

The metabolic syndrome (MetS) is a major global problem, and inflammation and insulin resistance appear to be key underpinnings in this cardio-metabolic cluster. MetS predisposes to an increased risk of diabetes and atherosclerotic cardiovascular disease (ASCVD). It has a procoagulant diathesis which included increased platelet activity and impaired fibrinolysis. High density lipoprotein (HDL) appears to be anti-thrombotic. Accordingly, we examined the ratios between platelets to HDL-cholesterol(C) and adiponectin (Adipo) in patients with nascent MetS without the confounding of diabetes, ASCVD and smoking to determine their validity as biomarkers of MetS.

METHODS

Patients with nascent MetS (n = 58) and matched controls (n = 44) were recruited. Fasting blood samples were obtained for complete blood counts, basic metabolic panel, lipids, insulin, and Adipo. Ratios of platelets to HDL-C and Adipo were calculated.

RESULTS

Following adjustment for adiposity, only the platelet: HDL ratio was significantly increased in MetS and increased with severity of MetS. Receiver operating characteristic curve analysis showed that the platelet: HDL-C area under the curve (AUC) significantly added to both platelets and platelet lymphocyte ratio AUCs. Also the platelet: HDL-C ratio correlated with all cardio-metabolic features of MetS, high sensitivity C-reactive protein, insulin resistance chemerin, and leptin.

CONCLUSIONS

The ratio of platelets: HDL-C is significantly increased in patients with nascent MetS and appear to be a valid biomarker of MetS. It could also emerge as a biomarker for athero-thrombotic risk. However, these preliminary findings need confirmation in large prospective studies.

The Role of P-Selectin in COVID-19 Coagulopathy: An Updated Review

In severe COVID-19, which is characterized by blood clots and neutrophil-platelet aggregates in the circulating blood and different tissues, an increased incidence of cardiovascular complications and venous thrombotic events has been reported. The inflammatory storm that characterizes severe infections may act as a driver capable of profoundly disrupting the complex interplay between platelets, endothelium, and leukocytes, thus contributing to the definition of COVID-19-associated coagulopathy. In this frame, P-selectin represents a key molecule expressed on endothelial cells and on activated platelets, and contributes to endothelial activation, leucocyte recruitment, rolling, and tissue migration. Briefly, we describe the current state of knowledge about P-selectin involvement in COVID-19 pathogenesis, its possible use as a severity marker and as a target for host-directed therapeutic intervention.

The Role of Chemokines in Psoriasis-An Overview

By participating in both the recruitment and activation of T lymphocytes, macrophages and neutrophils at the site of psoriatic inflammation, chemokines play an important role in the pathogenesis of psoriasis and, crucially, may be one indicator of the response to the systemic treatment of the disease. As a result of their major involvement in both physiological and pathological processes, both chemokines and their receptors have been identified as possible therapeutic targets. Due to their presence in the inflammatory process, they play a role in the pathogenesis of diseases that often coexist with psoriasis, such as atherosclerosis and psoriatic arthritis. Chemokines, cytokines and adhesion molecules may be biological markers of disease severity in psoriasis. However, the mechanism of inflammation in psoriasis is too complex to select only one marker to monitor the disease process and improvement after treatment. The aim of this review was to summarize previous reports on the role of chemokines in the pathogenesis of psoriasis, its treatment and comorbidities.

Exposure to fine particulate matter promotes platelet activation and thrombosis via obesity-related inflammation

Short-term exposure to fine particulate matter (PM_2.5) increases thrombotic risk particularly in obese individuals, but the underlying mechanisms remain unclear. This study aims to compare the effects of PM_2.5 on inflammation and platelet activation in obese versus normal-weight adults, and investigate potential causal pathways. We conducted a panel study measuring blood markers in 44 obese and 53 normal-weight adults on 3 separate occasions in 2017-2018. Associations between PM_2.5/black carbon (BC) and biomarkers were estimated using mixed-effect models. An interaction analysis compared PM_2.5/BC-related effects between subgroups. Biomarker combinations and mediation analysis were performed to elucidate the biological pathways. There was a significant "low-high-low" trend of PM_2.5 levels across the 3 study periods. Increases in pro-inflammatory cytokines and changes of platelet activation and aggregation markers were associated with PM_2.5/BC in obese subgroup only. Among obese subjects, the combination of pro-inflammatory cytokines and that of platelet markers increased 26.8% (95% CI: 16.0%, 37.9%) and 14.7% (95% CI: 1.9%, 27.0%) per IQR increase in PM_2.5 over 5-day and 7-day averages. Inflammation mediated 24.5% of the pathways through which PM_2.5 promoted platelet activation. This study suggested obese people are susceptible to pro-thrombotic impacts of PM_2.5 exposures. PM_2.5 may aggravate thrombosis through obesity-related inflammation.

PCSK9 Biology and Its Role in Atherothrombosis

It is now about 20 years since the first case of a gain-of-function mutation involving the as-yet-unknown actor in cholesterol homeostasis, proprotein convertase subtilisin/kexin type 9 (PCSK9), was described. It was soon clear that this protein would have been of huge scientific and clinical value as a therapeutic strategy for dyslipidemia and atherosclerosis-associated cardiovascular disease (CVD) management. Indeed, PCSK9 is a serine protease belonging to the proprotein convertase family, mainly produced by the liver, and essential for metabolism of LDL particles by inhibiting LDL receptor (LDLR) recirculation to the cell surface with the consequent upregulation of LDLR-dependent LDL-C levels. Beyond its effects on LDL metabolism, several studies revealed the existence of additional roles of PCSK9 in different stages of atherosclerosis, also for its ability to target other members of the LDLR family. PCSK9 from plasma and vascular cells can contribute to the development of atherosclerotic plaque and thrombosis by promoting platelet activation, leukocyte recruitment and clot formation, also through mechanisms not related to systemic lipid changes. These results further supported the value for the potential cardiovascular benefits of therapies based on PCSK9 inhibition. Actually, the passive immunization with anti-PCSK9 antibodies, evolocumab and alirocumab, is shown to be effective in dramatically reducing the LDL-C levels and attenuating CVD. While monoclonal antibodies sequester circulating PCSK9, inclisiran, a small interfering RNA, is a new drug that inhibits PCSK9 synthesis with the important advantage, compared with PCSK9 mAbs, to preserve its pharmacodynamic effects when administrated every 6 months. Here, we will focus on the major understandings related to PCSK9, from its discovery to its role in lipoprotein metabolism, involvement in atherothrombosis and a brief excursus on approved current therapies used to inhibit its action.

Platelets: The Emerging Clinical Diagnostics and Therapy Selection of Cancer Liquid Biopsies

Due to the inherent molecular heterogeneity of metastatic tumours and the dynamic evolution ability of tumour genomes, tumour tissues obtained through biopsy and other methods cannot capture all of the features of tumour genomes. A new diagnostic concept called “liquid biopsy” has received widespread attention in recent years. Liquid biopsy has changed the clinical practice of oncology and is widely used to guide targeted drug utilization, monitor disease progression and track drug resistance. The latest research subject in liquid biopsy is platelets. Platelets originate from multifunctional haematopoietic stem cells in the bone marrow haematopoietic system. They are small cells from the cytoplasm of bone marrow megakaryocytes. Their main physiological functions are to participate in the processes of physiological haemostasis and coagulation. Tumour cells transfer biomolecules (such as RNA) to platelets through direct contact and release of exosomes, which changes the platelet precursor RNA. Under the stimulation of tumour cells and the tumour microenvironment, platelet precursor mRNA is spliced into mature RNA and converted into functional protein to respond to external stimuli, forming tumour-educated platelets (TEPs). The detection of TEPs in the peripheral blood of patients is expected to be used in clinical tumour diagnosis. This emerging liquid biopsy method can replace and supplement the current tumour detection methods. Further research on the role of platelets in tumour diagnosis will help provide a novel theoretical basis for clinical tumour diagnosis.

The emerging role of phosphorus in human health

Phosphorus, an essential nutrient, performs vital functions in skeletal and non-skeletal tissues and is pivotal for energy production. The last two decades of research on the physiological importance of phosphorus have provided several novel insights about its dynamic nature as a nutrient performing functions as a phosphate ion. Phosphorous also acts as a signaling molecule and induces complex physiological responses. It is recognized that phosphorus homeostasis is critical for health. The intake of phosphorus by the general population world-wide is almost double the amount required to maintain health. This increase is attributed to the incorporation of phosphate containing food additives in processed foods purchased by consumers. Research findings assessed the impact of excessive phosphorus intake on cells' and organs' responses, and highlighted the potential pathogenic consequences. Research also identified a new class of bioactive phosphates composed of polymers of phosphate molecules varying in chain length. These polymers are involved in metabolic responses including hemostasis, brain and bone health, via complex mechanism(s) with positive or negative health effects, depending on their chain length. It is amazing, that phosphorus, a simple element, is capable of exerting multiple and powerful effects. The role of phosphorus and its polymers in the renal and cardiovascular system as well as on brain health appear to be important and promising future research directions.

The relationship between mean platelet volume and metabolic syndrome in patients with type 2 diabetes mellitus: A retrospective study

This study aimed to investigate the association between mean platelet volume (MPV) and metabolic syndrome (MetS) in patients with type 2 diabetes mellitus (T2DM). Data for 1240 patients with T2DM admitted to the Department of Endocrinology at the First Affiliated Hospital of Guangxi Medical University between January 1, 2017 and June 1, 2020 were collected retrospectively via electronic medical records, including demographic information, complete blood count, lipid profile, and glucose metabolism indexes. MetS was defined according to the Chinese Diabetes Society. Among the 1240 patients enrolled, 873 (70.40%) had MetS. MPV was significantly higher in patients with MetS (P < .001). For individual MetS components, MPV was significantly higher in the presence of abdominal obesity (P = .013) and hypertriglyceridemia (P = .026), but did not differ in the presence of elevated blood pressure (P = .330) or low high-density lipoprotein cholesterol (P = .790). Moreover, MPV was independently associated with MetS after adjustment for sex, smoking, alcohol drinking, white blood cell count, fasting C-peptide, and body mass index (odds ratio 1.174, 95% confidence interval 1.059-1.302). The odds ratio for MetS in the highest tertile, compared with the lowest MPV tertile, was 1.724 (95% confidence interval 1.199-2.479, P for trend = .003) after multiple adjustment. In stratified analyses, the positive correlation of MPV with MetS was significant only in patients who were older, male, or overweight, or who had poor glycemic control. In conclusion, high MPV was positively associated with the presence of MetS in patients with T2DM, particularly older, male, or overweight patients, or those with poor glycemic control.

The role of oxidant-antioxidant markers and resistin in metabolic syndrome elderly individuals

In elderly, hormones and oxidant-antioxidant interplay are suggested to mediate biochemical balance between adipose tissue to other tissues. Thus the study attempts to explore metabolic traits, plasma resistin, and oxidant-antioxidant markers in metabolic syndrome (MetS) in comparison to non-metabolic syndrome (non-MetS) elderly individuals. A total of 541 healthy elderly Caucasians, with no acute and/or chronic disorders were invited. After taking into account inclusion/exclusion criteria's the MetS was defined as the presence of three out of five abnormal findings and allowed to divided groups into: non-metabolic syndrome, non-MetS (n = 25, median age 69.0 years), and newly diagnosed MetS (n = 29; median age 70.5 years) individuals. Glucose, plasma lipids, resistin (Res), thiobarbituric acid-reacting substances (TBARS), total antioxidant status (TAS), and Cu,Zn-superoxide dismutase (SOD-1) were measured. The MetS had higher resistin than non-MetS (p < 0.04). The linear correlation (all at p < 0.05) showed correlation for Res&triacylglycerols (R = 0.44), and for Res&diastolic blood pressure (R = -0.58) and for SOD-1&fasting glucose (R = -0.34) in MetS, while in the non-MetS group fasting glucose correlates with Res (R = 0.58) and with TAS (R = -0.43). The multiple regression analysis (alone and in combination) showed that independently from other factors resistin correlated positively with fasting glucose (β = 0.37; R = 0.58; R2 = 0.23; p < 0.01) in all investigated elderly participants. In the MetS resistin correlated negatively with diastolic blood pressure (β = -0.68; R = 0.80; R2 = 0.53; p = 0.0004) moreover in that group TAS correlated negatively with HDL-C (β = -0.71; R = 0.72; R2 = 0.37; p = 0.01). While age correlated negatively with systolic blood pressure (β = -0.60; R = 0.62; R2 = 0.14; p = 0.03) independently from other factors in the non-MetS group. Various metabolic factors contribute to maintain serum resistin and oxidant-antioxidant balance in the elderly people in the presence or absence of MetS. Resistin may serve as a predictor of MetS in the elderly, while strong antioxidant defense interactions in older individuals may indicate good health.

Protein Disulphide Isomerase and NADPH Oxidase 1 Cooperate to Control Platelet Function and Are Associated with Cardiometabolic Disease Risk Factors

Background: Protein disulphide isomerase (PDI) and NADPH oxidase 1 (Nox-1) regulate platelet function and reactive oxygen species (ROS) generation, suggesting potentially interdependent roles. Increased platelet reactivity and ROS production have been correlated with cardiometabolic disease risk factors. Objectives: To establish whether PDI and Nox-1 cooperate to control platelet function. Methods: Immunofluorescence microscopy was utilised to determine expression and localisation of PDI and Nox-1. Platelet aggregation, fibrinogen binding, P-selectin exposure, spreading and calcium mobilization were measured as markers of platelet function. A cross-sectional population study (n = 136) was conducted to assess the relationship between platelet PDI and Nox-1 levels and cardiometabolic risk factors. Results: PDI and Nox-1 co-localized upon activation induced by the collagen receptor GPVI. Co-inhibition of PDI and Nox-1 led to additive inhibition of GPVI-mediated platelet aggregation, activation and calcium flux. This was confirmed in murine Nox-1^−/− platelets treated with PDI inhibitor bepristat, without affecting bleeding. PDI and Nox-1 together contributed to GPVI signalling that involved the phosphorylation of p38 MAPK, p47phox, PKC and Akt. Platelet PDI and Nox-1 levels were upregulated in obesity, with platelet Nox-1 also elevated in hypertensive individuals. Conclusions: We show that PDI and Nox-1 cooperate to control platelet function and are associated with cardiometabolic risk factors.

Till Death Do Us Part-The Multifaceted Role of Platelets in Liver Diseases

Platelets are tightly connected with the liver, as both their production and their clearance are mediated by the liver. Platelets, in return, participate in a variety of liver diseases, ranging from non-alcoholic fatty liver diseases, (viral) hepatitis, liver fibrosis and hepatocellular carcinoma to liver regeneration. Due to their versatile functions, which include (1) regulation of hemostasis, (2) fine-tuning of immune responses and (3) release of growth factors and cellular mediators, platelets quickly adapt to environmental changes and modulate disease development, leading to different layers of complexity. Depending on the (patho)physiological context, platelets exert both beneficial and detrimental functions. Understanding the precise mechanisms through which platelet function is regulated at different stages of liver diseases and how platelets interact with various resident and non-resident liver cells helps to draw a clear picture of platelet-related therapeutic interventions. Therefore, this review summarizes the current knowledge on platelets in acute and chronic liver diseases and aims to shed light on how the smallest cells in the circulatory system account for changes in the (patho)physiology of the second largest organ in the human body.

Mechanisms Underlying Hepatocellular Carcinoma Progression in Patients with Type 2 Diabetes

Hepatocellular carcinoma (HCC) ranks third in cancer-related deaths from solid tumors worldwide. The incidence of type 2 diabetes mellitus (T2DM) has increased worldwide in conjunction with the expansion of the Western lifestyle. Furthermore, patients with T2DM have been documented to have an increased risk of HCC, as well as bile tract cancer. Growing evidence shows that T2DM is a strong additive metabolic risk factor for HCC, but how diabetes affects the incidence of HCC requires additional investigation. In this review, we discuss the underlying mechanisms of HCC in patients with T2DM. Topics covered include abnormal glucose and lipid metabolism, hyperinsulinemia, and insulin resistance; the effect of activated platelets; hub gene expression associated with HCC; inflammation and signaling pathways; miRNAs; altered gut microbiota and immunomodulation. The evidence suggests that reducing obesity, diabetes, and nonalcoholic fatty liver disease/nonalcoholic steatohepatitis through efficient measures of prevention may lead to decreased rates of T2DM-related HCC.

Effect of Differently Fed Farmed Gilthead Sea Bream Consumption on Platelet Aggregation and Circulating Haemostatic Markers among Apparently Healthy Adults: A Double-Blind Randomized Crossover Trial

Fish consumption beneficially affects coagulation markers. Few dietary intervention studies have investigated differently fed farmed fish against these cardio-metabolic risk factors in humans. This double-blind randomized crossover trial evaluated differently fed farmed gilthead sea bream consumption against platelet aggregation and circulating haemostatic markers among apparently healthy adults. Subjects aged 30-65 years, with a body mass index 24.0-31.0 kg/m², consuming less than 150 g cooked fish per week, were recruited in Attica, Greece. Participants were randomized (n = 38, 1:1) to one of two sequences; consumption of fish fed with fish oil diet (conventional fish, CF)/fish fed with olive pomace-enriched diet (enriched fish, EF) versus EF/CF. The primary outcomes were ex vivo human platelet aggregation and circulating plasminogen activator inhibitor-1 (PAI-1) and P-selectin (sP-selectin) concentrations. EF consumption had no significant effect on platelet sensitivity or haemostatic markers compared to CF. Platelet sensitivity to platelet-activating factor (PAF) decreased after CF consumption during the second period (p < 0.01). Plasma PAI-1 and sP-selectin concentrations increased after CF consumption during both periods (p < 0.01 for both). Based on current findings, consumption of enriched farmed gilthead sea bream had no greater effect on coagulation markers in adults compared to the conventionally fed fish.

INTERRELATIONS BETWEEN GROWTH DIFFERENTIATION FACTOR 15, P-SELECTIN AND GALECTIN-3 AND CLINICAL COURSE IN PATIENTS WITH ARTERIAL HYPERTENSION AND TYPE 2 DIABETES MELLITUS

The aim of our study was to determine the base levels of Growth Differentiation Factor 15, P-selectin and Galectin-3 in blood plasma in patients with AH and T2DM and to assess their association with the diseases clinical course. Materials and methods. A total of 121 patients were included in our study (60 female and 61 male, mean age 64.7±10.6 years, with AH and/or T2DM). Patients were divided into three groups: 1st group with AH only (51 patient), 2nd group with AH and T2DM (57 patients) and 3rd group with T2DM only (13 patients, control group). GDF-15, Galectin-3 and P-selectin tests were performed using standard enzyme-linked immunosorbent assay kits (ELISA). Results. Compared with AH without T2DM and T2DM only groups, AH with T2DM group had a statistically significant higher level of GDF-15. Grade 3 hypertension group had a significantly lower level of GDF-15 compared with Grade 1&2 hypertension groups. P-selectin mean level was significantly higher in Grade 3 hypertension group GDF-15 compared with Grade 1&2 hypertension groups. We observed weak correlation between Galectin-3 and GDF-15 in blood plasma, which was confirmed by linear regression analysis. Conclusions. A combination of hypertension and type 2 diabetes mellitus revealed a significant increase of GDF-15 levels in compare with patients with only hypertension or type 2 diabetes mellitus, which may be due to a greater response to oxidative stress and low-intensity systemic inflammation. P-selectin mean level was higher in patients with grade 3 hypertension, which reflects a greater platelet activation as a part of the systemic inflammatory response. Galectin-3 mean level was higher in patients with stage 3 hypertension compared with patients with stages 1 and 2 due to possibly more pronounced fibrosis progression.

Leptin, Resistin, and Proprotein Convertase Subtilisin/Kexin Type 9: The Role of STAT3

In a condition of dysfunctional visceral fat depots, as in the case of obesity, alterations in adipokine levels may be detrimental for the cardiovascular system. The proinflammatory leptin and resistin adipokines have been described as possible links between obesity and atherosclerosis. The present study was aimed at evaluating whether proprotein convertase subtilisin/kexin type 9 (PCSK9), a key regulator of low-density lipoprotein metabolism, is induced by leptin and resistin through the involvement of the inflammatory pathway of STAT3. In HepG2 cells, leptin and resistin up-regulated PCSK9 gene and protein expression, as well as the phosphorylation of STAT3. Upon STAT3 silencing, leptin and resistin lost their ability to activate PCSK9. The knockdown of STAT3 did not affect the expression of leptin and resistin receptors or that of PCSK9. The analysis of the human PCSK9 promoter region showed that the two adipokines raised PCSK9 promoter activity via the involvement of a sterol regulatory element motif. In healthy males, a positive association between circulating leptin and PCSK9 levels was found only when the body mass index was <25 kg/m². In conclusion, this study identified STAT3 as one of the molecular regulators of leptin- and resistin-mediated transcriptional induction of PCSK9.

Hypercoagulopathy and Adipose Tissue Exacerbated Inflammation May Explain Higher Mortality in COVID-19 Patients With Obesity

COVID-19, caused by SARS-CoV-2, is characterized by pneumonia, lymphopenia, exhausted lymphocytes and a cytokine storm. Several reports from around the world have identified obesity and severe obesity as one of the strongest risk factors for COVID-19 hospitalization and mechanical ventilation. Moreover, countries with greater obesity prevalence have a higher morbidity and mortality risk of developing serious outcomes from COVID-19. The understanding of how this increased susceptibility of the people with obesity to develop severe forms of the SARS-CoV-2 infection occurs is crucial for implementing appropriate public health and therapeutic strategies to avoid COVID-19 severe symptoms and complications in people living with obesity. We hypothesize here that increased ACE2 expression in adipose tissue displayed by people with obesity may increase SARS-CoV-2 infection and accessibility to this tissue. Individuals with obesity have increased white adipose tissue, which may act as a reservoir for a more extensive viral spread with increased shedding, immune activation and pro-inflammatory cytokine amplification. Here we discuss how obesity is related to a pro-inflammatory and metabolic dysregulation, increased SARS-CoV-2 host cell entry in adipose tissue and induction of hypercoagulopathy, leading people with obesity to develop severe forms of COVID-19 and also death. Taken together, it may be crucial to better explore the role of visceral adipose tissue in the inflammatory response to SARS-CoV-2 infection and investigate the potential therapeutic effect of using specific target anti-inflammatories (canakinumab or anakinra for IL-1β inhibition; anti-IL-6 antibodies for IL-6 inhibition), anticoagulant or anti-diabetic drugs in COVID-19 treatment of people with obesity. Defining the immunopathological changes in COVID-19 patients with obesity can provide prominent targets for drug discovery and clinical management improvement.