Platelet CD62p expression and microparticle in murine acquired immune deficiency syndrome and chronic ethanol consumption

Hutchinson-Gilford progeria syndrome mice display accelerated arterial thrombus formation and increased platelet reactivity

INTRODUCTION

Hutchinson-Gilford Progeria Syndrome (HGPS) is an ultra-rare premature aging genetic disorder caused by a point mutation in the lamin A gene, LMNA. Children with HGPS display short lifespans and typically die due to myocardial infarction or ischemic stroke, both acute cardiovascular events that are tightly linked to arterial thrombosis. Despite this fact, the effect of the classic HGPS LMNA gene mutation on arterial thrombosis remains unknown.

METHODS

Heterozygous LmnaG609G knock-in (LmnaG609G/+) mice, yielding an equivalent classic mutation observed in HGPS patients (c.1824C>T; pG608G mutation in the human LMNA gene) and corresponding wild-type (WT) control littermates underwent photochemically laser-induced carotid injury to trigger thrombosis. Coagulation and fibrinolytic factors were measured. Furthermore, platelet activation and reactivity were investigated.

RESULTS

LmnaG609G/+ mice displayed accelerated arterial thrombus formation, as underlined by shortened time to occlusion compared to WT littermates. Levels of factors involved in the coagulation and fibrinolytic system were comparable between groups, while LmnaG609G/+ animals showed higher plasma levels of thrombin-antithrombin complex and lower levels of antithrombin. Bone marrow analysis showed larger megakaryocytes in progeric mice. Lastly, enhanced platelet activation upon adenosine diphosphate, collagen-related peptide, and thrombin stimulation was observed in LmnaG609G/+ animals compared to the WT group, indicating a higher platelet reactivity in progeric animals.

CONCLUSIONS

LMNA mutation in HGPS mice accelerates arterial thrombus formation, which is mediated, at least in part, by enhanced platelet reactivity, which consequently augments thrombin generation. Given the wide spectrum of antiplatelet agents available clinically, further investigation is warranted to consider the most suitable antiplatelet regimen for children with HGPS to mitigate disease mortality and morbidity.

Noninvasive Biomarkers for Alcohol-Related Liver Disease-A Proteomic Related Preliminary Report

Increased alcohol intake over decades leads to progressive alcohol-related liver disease (ALD) and contributes to increased mortality. It is characterized by reduced platelet count. Platelets have a role in protecting vascular integrity and involved in liver regeneration. Alcohol affects the platelet count and its function. Platelet function is regulated by their proteins, released during pathophysiological conditions. Therefore, platelet proteome plays a vital role during ALD. This preliminary study consists of 10 patients with ALD. It includes the preparation of human platelets for the proteomic approach. We performed liquid chromatography-mass spectrometry for the samples. A total of 536 proteins were identified in patients with ALD of which 31 proteins were mentioned as a candidate based on their clinical significance. The advancement of diagnostic or therapeutic tools based on the application of platelet proteins in ALD is still far off. Platform for platelet and its proteome research may give diagnostic and prognostic insights into ALD. Platelet proteomes could possibly be concluded as therapeutic and potential diagnostic or prognostic markers in ALD.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12291-023-01120-9.

Functional analysis and expression profile of human platelets infected by EBV in vitro

Platelet activation is commonly detected after infection by multiple viruses such as human immunodeficiency virus (HIV), H1N1 influenza, Hepatitis C virus (HCV), Ebola virus (EBV), and Dengue virus (DENV). Non-coding RNAs (ncRNAs) constitute the majority of the human transcribed genome, but the biology of platelet ncRNAs is largely unexplored. In this study, we performed microarray profiling to characterize the expression profile of human platelets infected with EBV in vitro after 2 h. A total of 187 long non-coding RNAs (lncRNAs) displayed differences, of which 114 were upregulated and 73 were downregulated; 78 microRNAs (miRNAs) showed differences, including 73 upregulated and 5 downregulated; 808 mRNAs displayed differences, among which 367 were upregulated and 441 were downregulated. Gene ontology (GO) analysis mostly related to G protein-coupled receptor signaling pathway, detection of chemical stimulus involved in sensory perception of smell and regulation of transcription by RNA polymerase II. Pathway analysis showed that the differentially expressed genes were mainly enriched in cell metabolism and immune-related response. A ceRNA network was established based on predicting regulatory pairs in differentially expressed genes, in which hsa-miR-6877-3p had the highest regulatory capability (degree = 31), FAM230A was the lncRNA with the highest regulatory capability (degree = 28). According to the EBV related miRNA regulation network, it revealed that ebv-miR-BART19-3p had the most target genes and BRWD1, FAM126B, TFRC and JMY were the genes most regulated by EBV-related miRNAs. After overlapping the three networks, we found that the EIFAK2 gene was strongly correlated with autologous ncRNAs, including hsa-miR-1972, hsa-miR-504-3p and hsa-miR-6825-5p, as well as with EBV ncRNAs, including EBER1, EBER2, miR-BART7-3p and miR-BART16. The present study contributes to a better understanding of the expression profiling of ncRNAs and their functions in platelets activated by EBV in vitro, and paves the way to further study on platelet function.

[Effect of ethanol on platelet biology]

In recent years, interest in the study of platelets, significantly increased due to recent discoveries providing convincing evidence that their functions by are not limited to their participation in the blood coagulation mechanism. Many works are devoted to the study of the functional state of platelets under conditions of acute and chronic alcohol exposure. The results of such studies can be useful for the development of new markers of the degree of alcohol intoxication of the body for the subsequent choice of the method drug correction of disorders caused by acute or chronic alcohol effects. The review summarizes results in vivo and in vitro of studies performed during more than 60 years on the effect of ethanol on the biogenesis, number, morphology and biochemistry of platelets.

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

BACKGROUND

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

The emerging roles of microvesicles in liver diseases

Microvesicles (MVs) are extracellular vesicles released by virtually all cells, under both physiological and pathological conditions. They contain lipids, proteins, RNAs and microRNAs and act as vectors of information that regulate the function of target cells. This Review provides an overview of the studies assessing circulating MV levels in patients with liver diseases, together with an insight into the mechanisms that could account for these changes. We also present a detailed analysis of the implication of MVs in key processes of liver diseases. MVs have a dual role in fibrosis as certain types of MVs promote fibrolysis by increasing expression of matrix metalloproteinases, whereas others promote fibrosis by stimulating processes such as angiogenesis. MVs probably enhance portal hypertension by contributing to intrahepatic vasoconstriction, splanchnic vasodilation and angiogenesis. As MVs can modulate vascular permeability, vascular tone and angiogenesis, they might contribute to several complications of cirrhosis including hepatic encephalopathy, hepatopulmonary syndrome and hepatorenal syndrome. Several results also suggest that MVs have a role in hepatocellular carcinoma. Although MVs represent promising biomarkers in patients with liver disease, methods of isolation and subsequent analysis must be standardized.

Flow cytometric assessment of circulating platelet and erythrocytes microparticles in young thalassemia major patients: relation to pulmonary hypertension and aortic wall stiffness

Heart disease is the leading cause of mortality and morbidity in β-thalassemia major (β-TM). Aggregability of abnormal red cells and membrane-derived microparticles (MPs) stemming from activated platelets and erythrocytes are responsible for thrombotic risk. We measured platelet and erythrocyte MPs (PMPs and ErMPs) in 60 young β-TM patients compared with 40 age- and sex-matched healthy controls and assessed their relation to clinicopathological characteristics and aortic elastic properties. Patients were studied stressing on transfusion history, splenectomy, thrombotic events, chelation therapy, hematological and coagulation profiles, flow cytometric measurement of PMPs (CD41b(+) ) and ErMPs (glycophorin A(+) ) as well as echocardiographic assessment of aortic elastic properties. Aortic stiffness index and pulmonary artery pressure were significantly higher, whereas aortic strain and distensibility were lower in TM patients than controls (P < 0.001). Both PMPs and ErMPs were significantly elevated in TM patients compared with controls, particularly patients with risk of pulmonary hypertension, history of thrombosis, splenectomy or serum ferritin >2500 μg/L (P < 0.001). Compliant patients on chelation therapy had lower MPs levels than non-compliant patients (P < 0.001). PMPs and ErMPs were positively correlated to markers of hemolysis, serum ferritin, D-dimer, vWF Ag, and aortic stiffness, whereas negatively correlated to hemoglobin level and aortic distensibility (P < 0.05). We suggest that increased MPs may be implicated in vascular dysfunction, pulmonary hypertension risk, and aortic wall stiffness observed in thalassemia patients. Their quantification could provide utility for early detection of cardiovascular abnormalities and monitoring the biological efficacy of chelation therapy.

Platelet-Derived Microparticles and Platelet Function Profile in Children With Congenital Heart Disease

Platelet microparticles (PMPs) and function profile in children with congenital heart disease (CHD) have not been widely explored. We investigated platelet aggregation, flow cytometric platelet surface receptors (P-selectin and glycoprotein (GP) IIb/IIIa) and PMPs in 23 children with cyanotic CHD (CCHD), 30 children with acyanotic CHD (ACHD) and 30 healthy controls correlating these variables to hematological and coagulation parameters including von Willebrand factor antigen (vWF Ag) as a marker of endothelial dysfunction. Hemoglobin, hematocrit (HCT), d-dimer, and vWF Ag were significantly higher in CCHD than ACHD group. Platelet MPs and P-selectin expression were increased in patients than controls, particularly in CCHD and positively correlated to HCT, d-dimer, and vWF Ag while platelet count, aggregation, and GP IIb/IIIa expression were decreased in CCHD compared with ACHD group and negatively correlated to HCT. The overproduction of PMPs and platelet activation with suppressed aggregation may be implicated in the pathogenesis of coagulation/hemostatic abnormalities in children with CCHD.

Whole blood aggregation, coagulation, and markers of platelet activation in diet-induced diabetic C57BL/6J mice

AIMS

Type 2 diabetes in humans is associated with hypercoaguability; however, little is known about platelet function in mouse models of type 2 diabetes used to study this disorder. Therefore, the purpose of this study was to examine platelet aggregation, coagulation, and markers of platelet activation in a diet-induced mouse model of type 2 diabetes.

METHODS

Four week old, male, C57BL/6J mice were randomized to a standard chow or high fat (60% beef lard) diet for 4 months. To examine platelet function we measured ADP-induced whole blood aggregometry, whole blood coagulation by thromboelastography, tail bleeding times, platelet microparticle and platelet expression of p-selectin and platelet expression of CD61 by flow cytometry.

RESULTS

Diabetic mice exhibited less aggregation (p<0.05), less coagulation (p<0.01), prolonged tail bleeding times (n.s.), and lower agonist stimulated platelet CD61 expression (p<0.001) compared to non-diabetic mice. There was no difference in platelet microparticle and platelet p-selectin expression.

CONCLUSIONS

Diet-induced type 2 diabetic mouse do not demonstrate the hypercoagulability and platelet activation typically observed in humans with this disorder. More studies are warranted to further explore platelet function in this mouse model; to determine their applicability for studying these alterations in type 2 diabetes.

Plasmodium yoelii yoelii 17XNL constitutively expressing GFP throughout the life cycle

Plasmodium yoelii is a rodent parasite commonly used as a model to study malaria infection. It is the preferred model parasite for liver-stage immunological studies and is also widely used to study hepatocyte, erythrocyte and mosquito infection. We have generated a P. yoelii yoelii 17XNL line that is stably transfected with the green fluorescent protein (gfp) gene. This parasite line constitutively expresses high levels of GFP during the complete parasite life cycle including liver, blood and mosquito stages. These fluorescent parasites can be used in combination with fluorescence activated cell sorting or live microscopy for a wide range of experimental applications.

Alcohol consumption and platelet activation and aggregation among women and men: the Framingham Offspring Study

BACKGROUND

Alcohol intake has been associated with lower platelet activity; however, few large-scale studies have included women, and to our knowledge, the relationship of alcohol intake with measures of platelet activation has not been studied.

METHODS

We performed a cross-sectional analysis of adults free of cardiovascular disease enrolled in the Framingham Offspring Study. Study physicians assessed alcohol consumption with a standardized questionnaire. We measured platelet activation in response to 1 and 5 microm of adenosine diphosphate (ADP) with a P-selectin assay among 1037 participants and platelet aggregability in response to ADP, epinephrine, and collagen among 2013 participants.

RESULTS

Alcohol consumption was inversely associated with P-selectin expression in response to 1 microm ADP (p = 0.007) and 5 microm ADP (p = 0.02) among men but not women. Alcohol consumption was also inversely associated with platelet aggregation induced by ADP among both women (p = 0.04) and men (p trend = 0.008) and by epinephrine among men (p = 0.03)

CONCLUSIONS

Alcohol consumption is inversely associated with both platelet activation and aggregation, particularly in men. Additional research is needed to determine whether these findings contribute to the contrasting associations of alcohol consumption with risk of thrombotic and hemorrhagic cardiovascular events.