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Platelets Dec 2023
Topics: Humans; Blood Platelets
PubMed: 37126352
DOI: 10.1080/09537104.2023.2204619 -
Thrombosis Research Nov 2023Platelet ageing is an area of research which has gained much interest in recent years. Newly formed platelets, often referred to as reticulated platelets, young... (Review)
Review
Platelet ageing is an area of research which has gained much interest in recent years. Newly formed platelets, often referred to as reticulated platelets, young platelets or immature platelets, are defined as RNA-enriched and have long been thought to be hyper-reactive. This latter view is largely rooted in associations and observations in patient groups with shortened platelet half-lives who often present with increased proportions of newly formed platelets. Evidence from such groups suggests that an increased proportion of newly formed platelets is associated with an increased risk of thrombotic events and a reduced effectiveness of standard anti-platelet therapies. Whilst research has highlighted the existence of platelet subpopulations based on function, size and age within patient groups, the common intrinsic changes which occur as platelets age within the circulation are only just being explored. By understanding the changes that occur during the natural ageing processes of platelets, we may be able to identify the triggers for alterations in platelet life span and platelet reactivity. Here we review research on platelet ageing in the context of health and disease, paying particular attention to the experimental approaches taken and the robustness of conclusions that can be drawn.
Topics: Humans; Blood Platelets; Aging
PubMed: 36587993
DOI: 10.1016/j.thromres.2022.12.004 -
Journal of Advanced Research Jul 2023Environmental microparticle is becoming a global pollutant and the entire population is increasingly exposed to the microparticles from artificial materials. The...
INTRODUCTION
Environmental microparticle is becoming a global pollutant and the entire population is increasingly exposed to the microparticles from artificial materials. The accumulation of microparticles including microplastics and its subsequent effects need to be investigated timely to keep sustainable development of human society.
OBJECTIVES
This study aimed to explore the accumulation of environmental particles in thrombus, the pathological structure in the blood circulation system.
METHODS
Patients receiving cardiovascular surgical operations were screened and twenty-six thrombi were collected, digested and filtered. Non-soluble microparticles were enriched on the filter membrane and then were analyzed and identified with Raman Spectrometer. The associations of particle status (presence or absence) or particle number in the thrombus and clinical indicators were examined. One strict quality control-particle detection system was designed to eliminate environmental contaminations.
RESULTS
Among twenty-six thrombi, sixteen contained eighty-seven identified particles ranging from 2.1 to 26.0 μm in size. The number of microparticles in each thrombus ranged from one to fifteen with the median reaching five. All the particles found in thrombi were irregularly block-shaped. Totally, twenty-one phthalocyanine particles, one Hostasol-Green particle, and one low-density polyethylene microplastic, which were from synthetic materials, were identified in thrombi. The rest microparticles included iron compounds and metallic oxides. After the adjustment for potential confounders, a significantly positive association between microparticle number and blood platelet levels was detected (P < 0.01).
CONCLUSION
This study provides the first photograph and Raman spectrum evidence of microparticles in thrombi. A large number of non-soluble particles including synthetic material microparticles could accumulate in arteries, suggesting that the risk of microparticle exposure was under-estimated and the re-evaluation of its health effects is urgently needed. There will be a series of reports on assessing the health effects of microparticle exposure in humans in the future and this research provided clues for the subsequent research.
Topics: Humans; Microplastics; Plastics; Thrombosis; Blood Platelets; Polyethylene
PubMed: 36116710
DOI: 10.1016/j.jare.2022.09.004 -
Blood Feb 2024In humans, ∼0.1% to 0.3% of circulating red blood cells (RBCs) are present as platelet-RBC (P-RBC) complexes, and it is 1% to 2% in mice. Excessive P-RBC complexes are...
In humans, ∼0.1% to 0.3% of circulating red blood cells (RBCs) are present as platelet-RBC (P-RBC) complexes, and it is 1% to 2% in mice. Excessive P-RBC complexes are found in diseases that compromise RBC health (eg, sickle cell disease and malaria) and contribute to pathogenesis. However, the physiological role of P-RBC complexes in healthy blood is unknown. As a result of damage accumulated over their lifetime, RBCs nearing senescence exhibit physiological and molecular changes akin to those in platelet-binding RBCs in sickle cell disease and malaria. Therefore, we hypothesized that RBCs nearing senescence are targets for platelet binding and P-RBC formation. Confirming this hypothesis, pulse-chase labeling studies in mice revealed an approximately tenfold increase in P-RBC complexes in the most chronologically aged RBC population compared with younger cells. When reintroduced into mice, these complexes were selectively cleared from the bloodstream (in preference to platelet-free RBC) through the reticuloendothelial system and erythrophagocytes in the spleen. As a corollary, patients without a spleen had higher levels of complexes in their bloodstream. When the platelet supply was artificially reduced in mice, fewer RBC complexes were formed, fewer erythrophagocytes were generated, and more senescent RBCs remained in circulation. Similar imbalances in complex levels and senescent RBC burden were observed in humans with immune thrombocytopenia (ITP). These findings indicate that platelets are important for binding and clearing senescent RBCs, and disruptions in platelet count or complex formation and clearance may negatively affect RBC homeostasis and may contribute to the known risk of thrombosis in ITP and after splenectomy.
Topics: Humans; Animals; Mice; Aged; Blood Platelets; Erythrocytes; Thrombocytopenia; Anemia, Sickle Cell; Malaria
PubMed: 37992231
DOI: 10.1182/blood.2023021611 -
Periodontology 2000 Feb 2024The use of platelet-rich fibrin (PRF) has gained tremendous popularity in recent years owing to its ability to speed wound healing postsurgery. However, to date, many... (Review)
Review
The use of platelet-rich fibrin (PRF) has gained tremendous popularity in recent years owing to its ability to speed wound healing postsurgery. However, to date, many clinicians are unaware of methods designed to optimize the technology. This overview article will discuss the advancements and improvements made over the years aimed at maximizing cell and growth factor concentrations. First, a general understanding explaining the differences between RPM and RCF (g-force) is introduced. Then, the low-speed centrifugation concept, fixed angle versus horizontal centrifugation, and methods to maximize platelet concentrations using optimized protocols will be discussed in detail. Thereafter, the importance of chemically modified PRF tubes without the addition of chemical additives, as well as regulation of temperature to induce/delay clotting, will be thoroughly described. This article is a first of its kind summarizing all recent literature on PRF designed to optimize PRF production for clinical treatment.
Topics: Humans; Platelet-Rich Fibrin; Centrifugation; Wound Healing; Blood Platelets; Intercellular Signaling Peptides and Proteins; Platelet Count; Blood Coagulation
PubMed: 37681522
DOI: 10.1111/prd.12521 -
EMBO Molecular Medicine Sep 2023Hyperreactive platelets are commonly observed in diabetic patients indicating a potential link between glucose homeostasis and platelet reactivity. This raises the...
Hyperreactive platelets are commonly observed in diabetic patients indicating a potential link between glucose homeostasis and platelet reactivity. This raises the possibility that platelets may play a role in the regulation of metabolism. Pancreatic β cells are the central regulators of systemic glucose homeostasis. Here, we show that factor(s) derived from β cells stimulate platelet activity and platelets selectively localize to the vascular endothelium of pancreatic islets. Both depletion of platelets and ablation of major platelet adhesion or activation pathways consistently resulted in impaired glucose tolerance and decreased circulating insulin levels. Furthermore, we found platelet-derived lipid classes to promote insulin secretion and identified 20-Hydroxyeicosatetraenoic acid (20-HETE) as the main factor promoting β cells function. Finally, we demonstrate that the levels of platelet-derived 20-HETE decline with age and that this parallels with reduced impact of platelets on β cell function. Our findings identify an unexpected function of platelets in the regulation of insulin secretion and glucose metabolism, which promotes metabolic fitness in young individuals.
Topics: Humans; Insulin Secretion; Insulin-Secreting Cells; Insulin; Blood Platelets; Glucose
PubMed: 37490001
DOI: 10.15252/emmm.202216858 -
International Journal of Molecular... Dec 2023Thrombocytes play an essential role in hemostasis and thrombosis. Moreover, the controlled activation of thrombocytes is required in reproduction and fertility. The... (Review)
Review
Thrombocytes play an essential role in hemostasis and thrombosis. Moreover, the controlled activation of thrombocytes is required in reproduction and fertility. The platelet-activating factor and the controlled activation of platelets have important roles in folliculogenesis, ovulation, placental development, implantation and embryo development. Activated platelets accumulate in the follicular vessels surrounding the follicle and, due to its released soluble molecules (factors, mediators, chemokines, cytokines, neurotransmitters), locally increase oocyte maturation and hormone secretion. Furthermore, activated platelets are involved in the pathogenesis of ovarian hyperstimulation syndrome (OHSS) and preeclampsia. Low-dose aspirin can prevent OHSS during ovulation induction, while intrauterine or intraovarian administration of platelet-rich plasma (PRP) increases the endometrium thickness and receptivity as well as oocyte maturation. Activated thrombocytes rapidly release the contents of intracellular granules and have multiple adhesion molecules and receptors on their surface. Considering the numerous homeostatic endocrine functions of thrombocytes, it is reasonable to suppose a platelet-associated regulatory system (PARS) in reproduction. Although we are far from a complete understanding of the regulatory processes, the results of PARS research and the therapeutic application of aspirin and PRP during in vitro fertilization are promising.
Topics: Pregnancy; Female; Humans; Blood Platelets; Placenta; Fertility; Fertilization in Vitro; Embryo Implantation; Ovarian Hyperstimulation Syndrome; Platelet-Rich Plasma; Aspirin
PubMed: 38139165
DOI: 10.3390/ijms242417336 -
JCI Insight Jul 2023Kawasaki disease (KD) is the leading cause of acquired heart disease among children. Increased platelet counts and activation are observed during the course of KD, and...
Kawasaki disease (KD) is the leading cause of acquired heart disease among children. Increased platelet counts and activation are observed during the course of KD, and elevated platelet counts are associated with higher risks of developing intravenous immunoglobulin resistance and coronary artery aneurysms. However, the role of platelets in KD pathogenesis remains unclear. Here, we analyzed transcriptomics data generated from the whole blood of patients with KD and discovered changes in the expression of platelet-related genes during acute KD. In the Lactobacillus casei cell wall extract (LCWE) murine model of KD vasculitis, LCWE injection increased platelet counts and the formation of monocyte-platelet aggregates (MPAs), upregulated the concentration of soluble P-selectin, and increased circulating thrombopoietin and interleukin 6 (IL-6). Furthermore, platelet counts correlated with the severity of cardiovascular inflammation. Genetic depletion of platelets (Mpl-/- mice) or treatment with an anti-CD42b antibody significantly reduced LCWE-induced cardiovascular lesions. Furthermore, in the mouse model, platelets promoted vascular inflammation via the formation of MPAs, which likely amplified IL-1B production. Altogether, our results indicate that platelet activation exacerbates the development of cardiovascular lesions in a murine model of KD vasculitis. These findings enhance our understanding of KD vasculitis pathogenesis and highlight MPAs, which are known to enhance IL-1B production, as a potential therapeutic target for this disorder.
Topics: Animals; Mice; Mucocutaneous Lymph Node Syndrome; Blood Platelets; Disease Models, Animal; Vasculitis; Inflammation
PubMed: 37279077
DOI: 10.1172/jci.insight.169855 -
Journal of Thrombosis and Haemostasis :... Jul 2023Platelets play a central role in the arrest of bleeding. The ability of platelets to engage with extracellular matrix proteins of the subendothelium has long been... (Review)
Review
Platelets play a central role in the arrest of bleeding. The ability of platelets to engage with extracellular matrix proteins of the subendothelium has long been recognized as a pivotal platelet attribute, underpinning adequate hemostasis. The propensity of platelets to rapidly bind and functionally respond to collagen was one of the earliest documented events in platelet biology. The receptor primarily responsible for mediating platelet/collagen responses was identified as glycoprotein (GP) VI and successfully cloned in 1999. Since that time, this receptor has held the attention of many research groups, and through these efforts, we now have an excellent understanding of the roles of GPVI as a platelet- and megakaryocyte-specific adheso-signaling receptor in platelet biology. GPVI is considered a viable antithrombotic target, as data obtained from groups across the world is consistent with GPVI being less involved in physiological hemostatic processes but participating in arterial thrombosis. This review will highlight the key aspects of GPVI contributions to platelet biology and concentrate on the interaction with recently identified ligands, with a focus on fibrin and fibrinogen, discussing the role of these interactions in the growth and stability of thrombi. We will also discuss important therapeutic developments that target GPVI to modulate platelet function while minimizing bleeding outcomes.
Topics: Humans; Blood Platelets; Collagen; Fibrin; Hemorrhage; Platelet Activation; Platelet Membrane Glycoproteins; Thrombosis
PubMed: 36990158
DOI: 10.1016/j.jtha.2023.03.022 -
International Journal of Molecular... Sep 2023Kidney disease is a major global health concern, affecting millions of people. Nephrologists have shown interest in platelets because of coagulation disorders caused by... (Review)
Review
Kidney disease is a major global health concern, affecting millions of people. Nephrologists have shown interest in platelets because of coagulation disorders caused by renal diseases. With a better understanding of platelets, it has been found that these anucleate and abundant blood cells not only play a role in hemostasis, but also have important functions in inflammation and immunity. Platelets are not only affected by kidney disease, but may also contribute to kidney disease progression by mediating inflammation and immune effects. This review summarizes the current evidence regarding platelet abnormalities in renal disease, and the multiple effects of platelets on kidney disease progression. The relationship between platelets and kidney disease is still being explored, and further research can provide mechanistic insights into the relationship between thrombosis, bleeding, and inflammation related to kidney disease, and elucidate targeted therapies for patients with kidney disease.
Topics: Humans; Immunity, Innate; Blood Platelets; Hemostasis; Inflammation; Kidney Diseases; Disease Progression
PubMed: 37834171
DOI: 10.3390/ijms241914724