Platelet Hyperactivity Research Articles

Role of Thrombosis in Neurodegenerative Diseases: An Intricate Mechanism of Neurovascular Complications.

Thrombosis, the formation of blood clots in arteries or veins, poses a significant health risk by disrupting the blood flow. It can potentially lead to major cardiovascular complications such as acute myocardial infarction or ischemic stroke (arterial thrombosis) and deep vein thrombosis or pulmonary embolism (venous thrombosis). Nevertheless, over the course of several decades, researchers have observed an association between different cardiovascular events and neurodegenerative diseases, which progressively harm and impair parts of the nervous system, particularly the brain. Furthermore, thrombotic complications have been identified in numerous clinical instances of neurodegenerative diseases, particularly Alzheimer's disease, Parkinson's disease, multiple sclerosis, and Huntington's disease. Substantial research indicates that endothelial dysfunction, vascular inflammation, coagulation abnormalities, and platelet hyperactivation are commonly observed in these conditions, collectively contributing to an increased risk of thrombosis. Thrombosis can, in turn, contribute to the onset, pathogenesis, and severity of these neurological disorders. Hence, this concise review comprehensively explores the correlation between cardiovascular diseases and neurodegenerative diseases, elucidating the cellular and molecular mechanisms of thrombosis in these neurodegenerative diseases. Additionally, a detailed discussion is provided on the commonly employed antithrombotic medications in the context of these neuronal diseases.

Functional Foods in Preventing Human Blood Platelet Hyperactivity-Mediated Diseases—An Updated Review

Backgrounds/Objectives: Abnormal platelet functions are associated with human morbidity and mortality. Platelets have emerged as critical regulators of numerous physiological and pathological processes beyond their established roles in hemostasis and thrombosis. Maintaining physiological platelet function is essential to hemostasis and preventing platelet-associated diseases such as cardiovascular disease, cancer metastasis, immune disorders, hypertension, diabetes, sickle cell disease, inflammatory bowel disease, sepsis, rheumatoid arthritis, myeloproliferative disease, and Alzheimer’s disease. Platelets become hyperactive in obesity, diabetes, a sedentary lifestyle, hypertension, pollution, and smokers. Platelets, upon activation, can trawl leukocytes and progenitor cells to the vascular sites. Platelets release various proinflammatory, anti-inflammatory, and angiogenic factors and shed microparticles in the circulation, thus promoting pathological reactions. These platelet-released factors also maintain sustained activation, further impacting these disease processes. Although the mechanisms are unknown, multiple stimuli induce platelet hyperreactivity but involve the early pathways of platelet activation. The exact mechanisms of how hyperactive platelets contribute to these diseases are still unclear, and antiplatelet strategies are inevitable for preventing these diseases. Reducing platelet function during the early stages could significantly impact these diseases. However, while this is potentially a worthwhile intervention, using antiplatelet drugs to limit platelet function in apparently healthy individuals without cardiovascular disease is not recommended due to the increased risk of internal bleeding, resistance, and other side effects. The challenge for therapeutic intervention in these diseases is identifying factors that preferentially block specific targets involved in platelets’ complex contribution to these diseases while leaving their hemostatic function at least partially intact. Since antiplatelet drugs such as aspirin are not recommended as primary preventives, it is essential to use alternative safe platelet inhibitors without side effects. Methods: A systematic search of the PUBMED database from 2000 to 2023 was conducted using the selected keywords: “functional foods”, “polyphenols”, “fatty acids”, “herbs”, fruits and vegetables”, “cardioprotective agents”, “plant”, “platelet aggregation”, “platelet activation”, “clinical and non-clinical trial”, “randomized”, and “controlled”. Results: Potent natural antiplatelet factors have been described, including omega-3 fatty acids, polyphenols, and other phytochemicals. Antiplatelet bioactive compounds in food that can prevent platelet hyperactivity and thus may prevent several platelet-mediated diseases, including cardiovascular disease. Conclusions: This narrative review describes the work during 2000–2023 in developing functional foods from natural sources with antiplatelet effects.

Dynamics of endothelial function in patients with arterial hypertension with different cardiovascular risk against the background of antihypertensive therapy

The aim of the work was to investigate the dynamics of endothelial markers in patients with arterial hypertension with different cardiovascular risk under the influence of the prescribed treatment during a year of observation. The first group (with a moderate risk of cardiovascular events) included 48 patients with arterial hypertension (AH). The second group consisted of 54 patients with hypertension and a high risk of cardiovascular events, namely type 2 diabetes. Each group of patients was randomized into two subgroups by blood pressure (BP) medication. In patients of subgroup 1a (n=29) and subgroup 2a (n=35) – the main subgroups – the therapy necessarily included the angiotensin II receptor antagonist losartan potas­sium in a dosage of 50-150 mg/day, depending on the blood pressure level. Patients of subgroup 1b (n=19) and subgroup 2b (n=19) – comparison subgroups were treated with antihypertensive drugs of other first-line groups according to the data of the unified clinical protocol for the treatment of hypertension. According to the ROC analysis, it was determined that the dynamics of endothelin-1 (ET-1) indicators after 9 and 12 months of therapy (a decrease of 12% or more from the initial level) can predict the normalization of indicators of the coagulation and anticoagulation systems with indicators of sensitivity and specificity – 85% (95% CI 62.1-96.6%) and 92.9% (95% CI 76.5-98.9%), respectively. A decrease in the level of Willebrand factor (fV) by 23% or more due to such a treatment time can be used as a prognostic sign in determining the regression of endothelial dysfunction with sensitivity – 75% (95% CI 50.9-91.2%), specificity – 100% (95% CI 87.5-100%). According to the given data, both in the group with moderate and with high cardiovascular risk, there is a relationship between endothelial dysfunction (ED) and the duration of hypertension, indicators of the lipid spectrum and abdominal obesity – factors that increase the viscous resistance of the blood circulation, as well as platelet hyperactivity in the bloodstream. We have also established that according to the dynamics of ET-1 indicators after 9 and 12 months of therapy (decrease by 27% or more from the initial level), it is possible to predict the normalization of indicators of the coagulation and anticoagulation systems with indicators of sensitivity – 81.8% (95% CI 59.7-94.7%), specificity – 90.6% (95% CI 75-97.9%). A decrease in the level of fV by 24.5% or more after a year of treatment can be used as a prognostic sign in determining the regression of endothelial dysfunction with sensitivity – 68.2% (95% CI 45.1-86.1%), specificity – 71.9% (95% CI 53.3-86.2%). The obtained results testify to the dominant role of type 2 diabetes as a factor in platelet disorders of hemostasis. Taking into account the positive dynamics of the above-mentioned markers of ED during the year of treatment, their relationship with the reduction of blood pressure, indicators of the lipid spectrum and abdominal obesity, it should be noted the positive effect of angiotensin II receptor blockers (BRA II) as endothelioprotective drugs. Considering the irrefutable literary data about the absence of thrombomodulin in the blood stream, even its insignificant appearance indicates the presence of endothelial dysfunction. Determining the state and dynamics of changes in endothelial function under the influence of prescribed therapy will make it possible to improve the diagnosis of endothelial function disorders and increase the effectiveness of treatment of patients with hypertension and various cardiovascular risks.

GSDME-mediated pyroptosis contributes to chemotherapy-induced platelet hyperactivity and thrombotic potential

AbstractThrombotic complications due to platelet hyperreactivity are a major cause of death in patients undergoing chemotherapy. However, the underlying mechanisms are not fully understood. Herein, using human platelets and platelets from mice lacking gasdermin E (GSDME), we showed that GSDME is functionally expressed in anucleate platelets, and that GSDME-mediated pyroptosis, a newly identified form of cell death in mammalian nucleated cells, contributes to platelet hyperactivity in cisplatin-based chemotherapy. Cisplatin or etoposide activates caspase-3 to cleave GSDME, thereby releasing the N-terminal fragment of GSDME (GSDME-N) toward the platelet plasma membrane, subsequently forming membrane pores and facilitating platelet granule release. This eventually promotes platelet hyperactivity and thrombotic potential. We identified flotillin-2, a scaffold protein, as a GSDME-N interactor that recruits GSDME-N to the platelet membrane. Loss of GSDME protects mice from cisplatin-induced platelet hyperactivity. Our results provide evidence that targeting GSDME-mediated pyroptosis could reduce thrombotic potential in chemotherapy.

Loss of Endogenous Nox2-NADPH Oxidase does not Prevent Age-induced Platelet Activation and Arterial Thrombosis in Mice

BackgroundReactive oxygen species (ROS) are known to contribute to platelet hyperactivation and thrombosis during aging, however, mechanistic contribution of the specific oxidative pathway remains elusive. We hypothesized that during aging, endogenous Nox2-NADPH oxidase contributes to platelet ROS accumulation and that loss of Nox2 will protect from platelet activation and thrombosis. MethodsWe studied littermates of Nox2-knockout (Nox2-KO) and wild type (Nox2-WT) mice at young (3-4 months) and old (18-20 months) age. Within platelets, we examined expression of subunits of NADPH oxidase and enzyme activity, oxidant levels, activation markers, aggregation, and secretion. We also assessed susceptibility to in vivo thrombosis in two experimental models. ResultsWhile aged Nox2-WT mice displayed increased mRNA levels for Nox2, aged Nox2-KO mice showed increase in Nox4 mRNA. However, neither the protein levels of several subunits, nor the activity of NADPH oxidase were found altered with age or genotype. Both aged Nox2-WT and aged Nox2-KO mice exhibited similar enhancement in levels of platelet-oxidants, granule release, αIIbβ3 activation, annexin V binding, aggregation and secretion, and a greater susceptibility to platelet-induced pulmonary thrombosis compared to young mice. In a photochemical injury model, adoptive transfer of platelets from aged Nox2-WT or Nox2-KO mice to the aged host mice resulted in similar time to develop occlusive thrombus in the carotid artery. These findings suggest that loss of endogenous Nox2 does not protect against age-related platelet activation and arterial thrombosis in mice. ConclusionsWe conclude that Nox2 is not an essential mediator of prothrombotic effects associated with aging.

A review of gut microbial metabolites and therapeutic approaches in hypertension

Abstract Background Hypertension is a prevalent and complex disease that is increasingly recognized to be influenced by the gut microbiome and its metabolites. Understanding the relationship between gut microbial metabolites and blood pressure regulation could provide new therapeutic avenues. Main body This review examines the role of key microbial metabolites—short-chain fatty acids, trimethylamine N-oxide, tryptophan derivatives, polyamines, bile acids, and phenylacetylglutamine—in blood pressure regulation. Short-chain fatty acids, produced through dietary fiber fermentation, can lower blood pressure by modulating immune responses and reducing inflammation. Elevated trimethylamine N-oxide levels are associated with increased cardiovascular risk and hypertension, influencing cholesterol metabolism and promoting atherosclerosis. Tryptophan derivatives interact with vascular and renal functions to modulate blood pressure. Polyamines affect blood pressure regulation through their impact on nitric oxide synthesis and vascular tone. Bile acids influence blood pressure via gut microbiota modulation and activation of metabolic receptors. Phenylacetylglutamine has been linked to hypertension through its effects on platelet hyperactivity and thrombosis. Therapeutic approaches targeting these metabolites, including probiotics, prebiotics, fecal microbiota transplantation, dietary interventions, and polyphenols, have shown varying degrees of success. Probiotics and prebiotics promote the growth of beneficial gut bacteria and may lower blood pressure. Dietary interventions, such as the Mediterranean diet, positively affect blood pressure and cardiovascular health by modulating the gut microbiota. Polyphenols, known for their antioxidant properties, are associated with blood pressure reductions and improved vascular function. Fecal microbiota transplantation shows promise in restoring gut microbial balance and improving metabolic health, potentially influencing blood pressure regulation. Conclusion The review highlights the significant role of gut microbial metabolites in regulating blood pressure, offering new avenues for hypertension management. Key metabolites, including short-chain fatty acids, trimethylamine N-oxide, and bile acids, play critical roles in blood pressure modulation. Therapeutic strategies targeting these metabolites, such as probiotics, prebiotics, and dietary interventions, hold promise, though further research is needed to fully understand their mechanisms and optimize their use. Advancing microbiota-based interventions through large-scale studies and exploring personalized therapies will be essential for developing effective treatments in hypertension management.

Double-stranded DNA enhances platelet activation, thrombosis, and myocardial injury via cyclic GMP-AMP synthase

Abstract Aims Elevated dsDNA levels in STEMI patients are associated with increased infarct size and worse clinical outcomes. However, the direct effect of dsDNA on platelet activation remains unclear. This study aims to investigate the direct influence of dsDNA on platelet activation, thrombosis, and the underlying mechanisms. Methods and Results Analysis of clinical samples revealed elevated plasma dsDNA levels in STEMI patients, which positively correlated with platelet aggregation and markers of neutrophil extracellular traps (NETs) such as MPO-DNA and CitH3. Platelet assays demonstrated the activation of the cGAS-STING pathway in platelets from STEMI patients. DsDNA directly potentiated platelet activation and thrombus formation. Mechanistic studies using G150 (cGAS inhibitor), H151 (STING inhibitor), and MCC950 (NLRP3 inhibitor), as well as cGAS-/-, STING-/- and NLRP3-/- mice showed that dsDNA activated cGAS, a previously unreported DNA sensor in platelets, and induced activation of the STING/NLRP3/caspase-1/IL-1β axis. This cascade enhanced platelet activation and thrombus formation. Platelet cGAS depletion or Palbociclib, a cGAS-STING inhibitor, approved by the FDA for advanced breast cancer, ameliorated myocardial ischemia-reperfusion injury in ApoE-/- mice fed with a high-fat diet for 12 weeks. Conclusions These results suggested that dsDNA is a novel driver of platelet activation and thrombus formation in STEMI patients. Translational Perspective ST-elevated myocardial infarction (STEMI) patients exhibit high levels of plasma double-stranded DNA (dsDNA), which directly potentiates platelet activation through the platelet cGAS/STING/NLRP3/caspase-1/IL-1β signaling pathway. STEMI patients may benefit from cGAS inhibition in the prevention of platelet hyperactivity and thrombus formation.

The effect of vibroacoustic therapy on the structural integrity of erythrocytes and platelets in patients with acute exogenous poisoning

Background. Vibroacoustic therapy is used as a non-drug method of correcting respiratory disorders in various diseases, including acute poisoning. The effect of vibroacoustic therapy on blood cells currently remains unexplored.Objective. To evaluate the impact of vibroacoustic therapy on the morphofunctional rate of erythrocytes and platelets in patients with acute poisoning in patients with acute poisoning.Material and methods. Thirty eight patients with complicated acute poisoning transferred to the Toxicology Department of the N.V. Sklifosovsky Research Institute for Emergency Medicine were examined. In 19 patients, along with the standard therapy, a vibroacoustic therapy was performed using a VibroLUNG device (the main study group); the other 19 patients received only standard therapy (the comparison group). Vibroacoustic therapy began on the 2nd day after the patient admission to the Toxicology Department. The course of vibroacoustic therapy consisted of 2–9 procedures. Morphofunctional analysis of erythrocytes and platelets in all cases was performed before the start of the vibroacoustic therapy (before treatment) and before discharge from the hospital (1–2 days after completing the vibroacoustic therapy course).Results. In both groups, before treatment, we noted normal morphofunctional rate of erythrocytes and normal level of platelets with granules in the circulating blood. The level of severely damaged or altered platelets was only slightly higher than normal and did not differ between the groups. Meanwhile, in 50% of patients, platelets had a tendency to spontaneous activation and hyperactivation. Before discharge, the morph functional parameters of erythrocytes and platelets did not significantly change in both groups, while treatment with vibroacoustic therapy allowed to eliminate or reduce spontaneous platelet activation in 7 of 9 patients in the main study group. In the comparison group spontaneous platelet activation was absent in only 3 of 10 patients. In parallel, the time till pneumonia resolution turned statistically significantly reduced, by 1.5 times.Conclusions. In acute exogenous poisoning with complicated course, the risk of spontaneous platelet activation and hyperactivation increases. Vibroacoustic therapy does not violate the structural integrity of circulating erythrocytes and platelets. Vibroacoustic therapy, using the VibroLUNG device, reduces the tendency of platelets to spontaneous activation and hyperactivation, reduces the time for resolving pneumonia.

Role of platelet autophagy in cardiovascular diseases

Platelet hyperactivity leads to thrombosis, the primary cause of cardiovascular and cerebrovascular adverse events. Emerging evidence suggests that autophagy plays a fundamental role in platelet function, both at baseline and in response to stress. Autophagy is an intracellular mechanism devoted to the removal and recycling of damaged cytoplasmic cargoes. Basal level of autophagy ensures physiological platelet aggregation and hemostasis. Autophagy is impaired in platelets isolated from subjects at high cardiovascular risk whereas autophagy stimulation reduces platelet hyperactivity, along with an overall amelioration of oxidative stress status. In this mini-review, we explore the current literature on the role of autophagy in platelet biology and its relevance as a therapeutic target for counteracting cardiovascular diseases.

Ginsenoside Rb prevents the metastasis of hepatocarcinoma by blocking the platelet-tumor cell interaction.

The interaction between platelets and tumor cells is a crucial step in the progression of tumor metastasis. Blocking platelet-tumor cell interaction is a potential target against metastasis. Ginsenoside Rb (G-Rb) exhibits potential anti-tumor pharmacological properties and may offer a therapeutic option for cancer. This study aimed to investigate anti-metastatic effects of G-Rb through regulating the crosstalk of platelets with tumor cells. In order to explore anti-metastatic effects of G-Rb in vitro, HepG2 cell and platelets were co-cultured to mimic the interaction of platelets with tumor cells. Wound healing and Transwell assays were used to assess the effect of G-Rb on cell migration and invasion. The expression of epithelial-mesenchymal transition (EMT)-related markers was determined by RT-qPCR and western blot assays. The aggregation and activation of platelets were detected by flow cytometry. Moreover, a lung metastasis model of mice was established to evaluate inhibitory effects of G-Rb in vivo. Metastatic nodules on the lung surface were counted and sections of lung tissues were stained by H&E. G-Rb effectively suppressed tumor metastasis in the co-culture of platelets with HepG2 cell. First, G-Rb treatment significantly inhibited the migration and invasion of HepG2 cells induced by platelets. Second, the expressions of EMT-related markers, including N-cadherin, Snail, and MMP9, were decreased by the treatment of G-Rb in the presence of platelets. Meanwhile, G-Rb also suppressed platelet hyperactivity by regulating the adhesion to tumor cells, activation, TCIPA, and TGF-β1 secretion of platelets in vitro. In addition, the results of in vivo experiments proved G-Rb administration not only significantly decreased lung metastasis but also attenuated platelets aberrant aggregation and activation in vivo. Our findings showed that G-Rb inhibited tumor metastasis and platelet activation through mediating platelet-tumor cell interaction, indicating the potential values of G-Rb in tumor metastasis therapy.

P-275 Advanced hemostasis assessment in endometriosis: strengthening confidence in the safety of hormonal treatments

Abstract Study question Are women with endometriosis in a state of systemic imbalance between pro- and anti-coagulants? Summary answer Women with endometriosis do not seem to exhibit a coagulation imbalance, at least at a systemic level. What is known already A state of platelet hyperactivation potentially leading to a hypercoagulation status has been described in women with endometriosis. This phenomenon could induce an altered local environment, promoting platelet-mediated paracrine changes in endometrial tissue and also increasing cardiovascular risk, which could be worsened by the use of estrogen dependent hormonal treatments. However, despite a slight difference in some coagulation parameters has been observed between women affected and controls, their levels remain, generally, within the normal reference range. Study design, size, duration This prospective case-control study including 101 women seeking infertility consultation at the Infertility Unit of Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, Milano between January and July 2023 aimed to assess hemostasis function beyond traditional coagulation parameters. Participants/materials, setting, methods Blood of women with endometriosis (n = 51) or tubal or male factor infertility (controls; n = 50) was obtained before any ART treatment, and a complete panel of coagulation tests were performed, including basic parameters (aPTT, PT, FVIII, FII, PC, AT, FIV-C, DD, vWF, ADMT) as well as more sophisticated ones, such as Thrombin Generation Assay and Thromboelastometry, providing data on endogenous thrombin potential (ETP), clot formation time (CFT) and maximal clot firmness (MCF). Main results and the role of chance There were no significant differences between cases and controls in terms of age (37 [34-39] vs 36 [33-39]; p = 0.53, respectively) and smoking habits (14% vs 28%; p = 0.14, respectively). Women affected had a lower BMI compared to controls (22.7 [20.9-24.9] vs 21.4 [19.6-23.8]; p = 0.03), as it is usually expected. Results from TGA were expressed as ETP ratio (with-/without- thrombomodulin), and high ones were indicative of thrombomodulin resistance, taken as indexes of procoagulant imbalance; however, it was not different between women with and without the disease (0.75 [0.65-0.82] vs 0.75 [0.66-0.82]; p = 0.82, respectively). Other markers of procoagulant imbalance evaluated by thromboelastometry were also similar between cases and controls, including CFT (66 sec [58-78] vs 65 sec [59-79]; p = 0.69, respectively) and MCF (65 mm [62-68] vs 66mm [63-68]; p = 0.95, respectively). Considering the vWF/ADAMTS13 ratio, recently proposed to be altered in endometriosis, no difference was seen between affected and no-affected women (0.95 [0.76-1.14] vs 0.91 [0.68-1.15]; p = 0.41, respectively). Finally, all the basic coagulation parameters were also similar between groups. Limitations, reasons for caution Our sample size does not allow us to perform sub-analyses regarding the type of endometriosis, although we cannot exclude differences according to the various manifestations of the disease. Also, not having a systemic haemostasis imbalance does not exclude the possibility of local coagulation imbalances. Wider implications of the findings An altered systemic haemostasis could be worsened by the use of hormonal treatments. Our result indicating that there is no coagulation imbalance at a systemic level reassures about the absence of further contraindications to hormonal drugs as a treatment for endometriosis. Trial registration number not applicable

Aging-related alterations in mechanistic target of rapamycin signaling promote platelet hyperreactivity and thrombosis

BackgroundAging is an independent risk factor for the development of cardiovascular, thrombotic, and other chronic diseases. However, mechanisms of platelet hyperactivation in aging remain poorly understood. ObjectivesHere, we examine whether and how aging alters intracellular signaling in platelets to support platelet hyperactivity and thrombosis. MethodsQuantitative mass spectrometry with tandem mass tag labeling systematically measured protein phosphorylation in platelets from healthy aged (>65 years) and young human (<45 years) subjects. The role of platelet mechanistic target of rapamycin (mTOR) in aging-induced platelet hyperreactivity was assessed using pharmacologic mTOR inhibition and a platelet-specific mTOR-deficient mouse model (mTORplt−/−). ResultsQuantitative phosphoproteomics uncovered differential site-specific protein phosphorylation within mTOR, Rho GTPase, and MAPK pathways in platelets from aged donors. Western blot confirmed constitutive activation of the mTOR pathway in platelets from both aged humans and mice, which was associated with increased aggregation compared with that in young controls. Inhibition of mTOR with either Torin 1 in aged humans or genetic deletion in aged mice reversed platelet hyperreactivity. In a collagen–epinephrine pulmonary thrombosis model, aged wild-type (mTORplt+/+) mice succumbed significantly faster than young controls, while time to death of aged mTORplt−/− mice was similar to that of young mTORplt+/+ mice. Mechanistically, we noted increased Rac1 activation and levels of mitochondrial reactive oxygen species in resting platelets from aged mice, as well as increased p38 phosphorylation upstream of thromboxane generation following agonist stimulation. ConclusionAging-related changes in mTOR phosphorylation enhance Rac1 and p38 activation to enhance thromboxane generation, platelet hyperactivity, and thrombosis.

1.8-cineole prevents platelet activation and aggregation by activating the cAMP pathway via the adenosine A2A receptor

AimsDysregulated platelet aggregation is a fatal condition in many bacterial- and virus-induced diseases. However, classical antithrombotics cannot completely prevent immunothrombosis, due to the unaddressed mechanisms towards inflammation. Thus, targeting platelet hyperactivation together with inflammation might provide new treatment options in diseases, characterized by immunothrombosis, such as COVID-19 and sepsis. The aim of this study was to investigate the antiaggregatory effect and mode of action of 1.8-cineole, a monoterpene derived from the essential oil of eucalyptus leaves, known for its anti-inflammatory proprieties. Main methodsPlatelet activity was monitored by measuring the expression and release of platelet activation markers, i.e., P-selectin, CD63 and CCL5, as well as platelet aggregation, upon treatment with 1.8-cineole and stimulation with several classical stimuli and bacteria. A kinase activity assay was used to elucidate the mode of action, followed by a detailed analysis of the involvement of the adenylyl-cyclase (AC)-cyclic adenosine monophosphate (cAMP)-protein kinase A (PKA) pathway by Western blot and ELISA. Key findings1.8-cineole prevented the expression and release of platelet activation markers, as well as platelet aggregation, upon induction of aggregation with classical stimuli and immunological agonists. Mechanistically, 1.8- cineole influences the activation of the AC-cAMP-PKA pathway, leading to higher cAMP levels and vasodilator-stimulated phosphoprotein (VASP) phosphorylation. Finally, blocking the adenosine A2A receptor reversed the antithrombotic effect of 1.8-cineole. SignificanceGiven the recognized anti-inflammatory attributes of 1.8-cineole, coupled with our findings, 1.8-cineole might emerge as a promising candidate for treating conditions marked by platelet activation and abnormal inflammation.

Biomarkers of in vivo platelet activation in thoroughbreds during their first long-term training.

Physical exercise has an activating effect on platelet function that differs between trained and untrained subjects, depending on the type of exercise and training status. In humans, soluble P-selectin (sP-sel) and platelet-derived extracellular vesicles (PEVs) are considered reliable markers of in vivo platelet activation during exercise. In untrained humans, they increase after transient physical exercise, whereas long-term training induces a decrease in their resting levels due to an improved ability to adapt to hemodynamic changes. The aim of this study was to assess whether circulating levels of sP-sel and PEVs may be useful markers to explore in vivo platelet function in never-trained Thoroughbreds during their first 4 months of incremental training. A total of 29 clinically healthy, untrained Thoroughbreds (17 males and 12 females) were enrolled. All horses were trained with the same training schedule (90 days). Blood samples were collected on the day the training program began (T0), 30 days (T30), and 90 days (T90) after its incremental increase to quantify platelet count, sP-sel (horse enzyme-linked immunosorbent assay) and PEVs (flow cytometry). Statistical analysis was performed using RM one-way analysis of variance with the Geisser-Greenhouse correction. Soluble P-selectin tended to increase at T30 compared with T0, while T90 levels returned to baseline values. Significantly higher circulating levels of PEVs CD61+/AnnV+ were observed at T30 and T90 compared to baseline confirming platelet hyperactivity. The detection and quantification of sP-sel and PEVs in equine racehorses during the training period appears to be a promising tool to study exercise-induced primary hemostatic changes and may provide an important marker for exercise selection.

Study of Platelet Indices as a Predictive Parameter for Diabetic Complications in Type II Diabetes Mellitu-A Cross Sectional Study

Introduction: Diabetes Mellitus is a prothrombotic state with enhanced platelet activity. The enhanced platelet activity may result in the development of microvascular and macrovascular complications. Platelet indices i.e. Mean Platelet volume (MPV), Platelet Distribution Width (PDW) are routinely available in alllaboratories and can be used to study as a prognostic marker for the patients. Aim: To evaluate platelet indices in patients with type 2 diabetes mellitus. Methods and Material: Cross sectional study was conducted in the Department of Pathology at a tertiary care centre over a period of 18 months. Samples of 120 patients of type 2 diabetes with and without complicationswere investigated. Haematological (platelet count and platelet indices i.e. Mean platelet indices and Platelet distribution width) and biochemical parameters (Fasting blood sugar and HbA1c) were compared between diabetic patients with and without complications. Platelet indices were measured using automated haematology analyser. Statistical evaluation was performed using SPSS version 16.0. Results: In DM with complication17 (28.33%) out of 60 cases were between the age group of 51-60 years, 14 (23.33%) out 60 belonged to the age group of 61-70 years and 12 (20%) patients were &gt;70 years of age. The mean platelet volume was 12.74±3.076 and 8.65±1.58 for diabetes with and without complications. The mean platelet distribution width was 15.54 and 13.94±2.66 for diabetes with and without complications. The mean HbA1c was 8.33 and 6.75 for diabetes with and without complications. The mean platelet count was 3.12 Lac/mm3 and 2.45 Lac/mm3 for diabetes with and without complications. The mean fasting blood sugar was 219.65 and 109.96 for diabetes with and without complications. Conclusion: Diabetes is responsible for endothelial dysfunction and platelet hyperactivity. In our study, diabetic patients with uncontrolled glycaemic index and raised fasting blood sugar level had raised platelet indices in comparison to patients without complication where the platelet count, platelet indices level and glycaemic index were within normal limits. These indices can also be used as a prognostic tool.

Insulin resistance and stroke: mechanisms and therapeutic approaches

The review analyzed literature data on the epidemio­logy, risk factors, and mechanisms of acute cerebrovascular accident (ACVA) in patients with diabetes mellitus. The role of insulin resistance and the effectiveness of therapeutic approaches to its correction in cerebral stroke are considered. Diabetes mellitus is recognized as an independent modifiable risk factor for ACVA. In people with diabetes of different age, the risk of stroke is increased by 2–6 times, and the indicators are especially high in patients of young working age. The presence of diabetes mellitus is associated with more severe symptoms, increased risk of complications, longer hospitalization, and higher mortality. Research results show that insulin resistance is one of the main triggers for the development of ischemic stroke due to embolism caused by oxidative stress, endothelial dysfunction and platelet hyperactivation, as well as due to atherosclerotic changes caused by inflammation, proliferation of smooth muscle cells of the vascular wall, dyslipidemia and hypertension on the background of hyperglycemia and hyperinsulinemia. It has been proven that insulin resistance not only provokes ACVA, but also negatively affects their prognosis. Metformin is a key drug for improving insulin sensitivity and is recognized as one of the most important first-line therapeutic agents to achieve and maintain treatment goals in patients with type 2 diabetes. The results of expe­rimental and clinical studies proved that this agent has a whole range of neuroprotective properties, which generally prevent the development of cerebral ischemia and reduce the negative consequences in case of its occurrence. Animals with experimental acute cerebral ischemia who have been treated with metformin had a better overall neurological score, significantly smaller infarct size, better coordination scores, and higher numbers of neurons and microglia. The neuroprotective effect of metformin in stroke is realized through the AMPK (5’AMP-activated protein kinase) signaling pathway with reduction of oxidative stress, neuroinflammation, stimulation of angiogenesis and neurogenesis, autophagy, and inhibition of apoptosis. According to data from cohort and randomized clinical trials, the use of metformin is associated with a significantly lower risk of developing ACVA. Long-term use of this drug in type 2 diabetes contributes to a milder course of stroke, is associated with better functional recovery, and a decrease in disability and mortality rates.

Platelet, Antiplatelet Therapy and Metabolic Dysfunction-Associated Steatotic Liver Disease: A Narrative Review.

Metabolic dysfunction-associated steatotic liver disease (MASLD) is not only related to traditional cardiovascular risk factors like type 2 diabetes mellitus and obesity, but it is also an independent risk factor for the development of cardiovascular disease. MASLD has been shown to be independently related to endothelial dysfunction and atherosclerosis. MASLD is characterized by a chronic proinflammatory response that, in turn, may induce a prothrombotic state. Several mechanisms such as endothelial and platelet dysfunction, changes in the coagulative factors, lower fibrinolytic activity can contribute to induce the prothrombotic state. Platelets are players and addresses of metabolic dysregulation; obesity and insulin resistance are related to platelet hyperactivation. Furthermore, platelets can exert a direct effect on liver cells, particularly through the release of mediators from granules. Growing data in literature support the use of antiplatelet agent as a treatment for MASLD. The use of antiplatelets drugs seems to exert beneficial effects on hepatocellular carcinoma prevention in patients with MASLD, since platelets contribute to fibrosis progression and cancer development. This review aims to summarize the main data on the role of platelets in the pathogenesis of MASLD and its main complications such as cardiovascular events and the development of liver fibrosis. Furthermore, we will examine the role of antiplatelet therapy not only in the prevention and treatment of cardiovascular events but also as a possible anti-fibrotic and anti-tumor agent.

Quantitative and structural changes of blood platelet cytoskeleton proteins in multiple sclerosis (MS)

Epidemiological studies show that cardiovascular events related to platelet hyperactivity remain the leading causes of death among multiple sclerosis (MS) patients. Quantitative or structural changes of platelet cytoskeleton alter their morphology and function. Here, we demonstrated, for the first time, the structural changes in MS platelets that may be related to their hyperactivity. MS platelets were found to form large aggregates compared to control platelets. In contrast to the control, the images of overactivated, irregularly shaped MS platelets show changes in the cytoskeleton architecture, fragmented microtubule rings. Furthermore, MS platelets have long and numerous pseudopodia rich in actin filaments. We showed that MS platelets and megakaryocytes, overexpress β1-tubulin and β-actin mRNAs and proteins and have altered post-translational modification patterns. Moreover, we identified two previously undisclosed mutations in the gene encoding β1-tubulin in MS. We propose that the demonstrated structural changes of platelet cytoskeleton enhance their ability to adhere, aggregate, and degranulate fueling the risk of adverse cardiovascular events in MS.

New light on changes in the number and function of blood platelets stimulated by cocoa and its products.

Hyperactivation of blood platelets, one of the causes of heart attack, and other cardiovascular diseases (CVDs), is influenced by various dietary components, including phenolic compounds from vegetables, fruits, teas, wines, cocoa and its products, including chocolate. The present paper sheds new light on the effect of cocoa and its products, especially dark chocolate, on the number and function of blood platelets, and the anti-platelet activity of their constituent phenolic compounds. A review was performed of papers identified in various electronic databases, including PubMed, Science Direct, Scopus, Web of Knowledge, and Google Scholar, with the aim of determining whether their anti-platelet activity may serve as part of a sweet strategy in countering CVDs. Various studies demonstrate that cocoa consumption, especially in the form of dark chocolate, with a high flavanol concentration, has anti-platelet activity and may play a significant role in cardioprotection; they also note that cocoa consumption may be a good strategy in diminishing cardiovascular risk, including hyperactivation of blood platelets.

High platelet adrenergic activity and concomitant activation of the pituitary/medullar axis as alarming laboratory parameters in ACS survivors-the STRESS-AMI study.

Kinetics of stress-related biological parameters were determined in acute coronary syndrome (ACS) patients undergoing complex cardiovascular rehabilitation. We determined platelet functionality in the absence/presence of a selective alpha-2 adrenergic receptor inhibitor, atipemazole parallel with salivary cortisol levels at enrolment, and at 3- and 12-months follow-up in 75 ACS patients with percutaneous coronary intervention. Pharmacological/non-pharmacological secondary prevention methods have been efficiently applied. Baseline aggregometry indicated platelet hyperactivity, decreasing gradually and being significantly reduced late, at 12 months (p < 0.05). Cortisol levels followed similar kinetics (p < 0.05). Baseline epinephrine-induced aggregations (EIA) significantly correlated with most of the other platelet agonists, even at subsequent time-points. Patients with upper-quartile EIA at enrolment (EIA-UQ) had significantly higher ADP- and collagen-induced aggregations at enrolment, at 3- and 12-months follow-up as well, indicating that high adrenergic response in the acute phase is accompanied by general platelet hyperactivity and predicts sustained platelet activation. In the EIA-UQ group higher cardiac biomarker release, elevated C-reactive protein and cortisol levels, and lower baseline left ventricular ejection fraction were detected.Atipemazole significantly reduced platelet aggregation induced by several platelet agonists, being most potent and comparable to full in vitro P2Y12 inhibition on collagen-induced aggregations (p < 0.05), indicating that catecholamines might serve as promt/long-term modulators of platelet function. Despite effective CCR programme and dual antiplatelet therapy, prolonged activation of sympathetic neuroendocrine system and general platelet hyperactivity can be detected up to one year in ACS patients with high adrenergic platelet activity. Moreover, initial high adrenergic activity is accompanied by clinical parameters associated to increased cardiovascular risk, therefore early identification of these patients might support complex optimal long-term therapy.