Protection of β2GPI-Deficient Mice from Thrombosis Reflects a Defect in PAR3-facilitated Platelet Activation.

Antibodies to β2-glycoprotein I (β2GPI) cause thrombosis in antiphospholipid syndrome, however the role of β2GPI in coagulation in vivo is not understood. To address this issue, we developed β2GPI-deficient mice (Apoh-/-) by deleting exon 2 and 3 of Apoh using CRISPR/Cas9 and compared the development of thrombosis in wild-type (WT) and Apoh-/- mice using rose bengal and FeCl3-induced carotid thrombosis, laser-induced cremaster arteriolar injury, and inferior vena cava (IVC) stasis models. We also compared tail bleeding times and activation of platelets from WT and Apoh-/- mice in the absence and presence of β2GPI.

Lysophosphatidylcholine induces oxidative stress and calcium-mediated cell death in human blood platelets.

Platelets are essential component of circulation that plays a major role in hemostasis and thrombosis. During activation and its demise, platelets release platelet-derived microvesicles, with lysophosphatidylcholine (LPC) being a prominent component in their lipid composition. LPC, an oxidized low-density lipoprotein, is involved in cellular metabolism, but its higher level is implicated in pathologies like atherosclerosis, diabetes, and inflammatory disorders.

Nanogold-coated stent facilitated non-invasive photothermal ablation of stent thrombosis and restoration of blood flow.

In-stent restenosis (ISR) and stent thrombosis (ST) are the most serious complications of coronary angioplasty and stenting. Although the evolution of drug-eluting stents (DES) has significantly restricted the incidence of ISR, they are associated with an enhanced risk of ST. In the present study, we explore the photothermal ablation of a thrombus using a nano-enhanced thermogenic stent (NETS) as a modality for revascularization following ST.

Non-canonical non-genomic morphogen signaling in anucleate platelets: a critical determinant of prothrombotic function in circulation.

Circulating platelets derived from bone marrow megakaryocytes play a central role in thrombosis and hemostasis. Despite being anucleate, platelets express several proteins known to have nuclear niche. These include transcription factors and steroid receptors whose non-genomic functions are being elucidated in platelets.

Protection of β2GPI Deficient Mice from Thrombosis Reflects a Defect in PAR3-facilitated Platelet Activation.

Background: Antibodies to β2-glycoprotein I (β2GPI) cause thrombosis in antiphospholipid syndrome, however the role of β2GPI itself in regulation of coagulation pathways is not well understood.

Methods: We developed β2GPI-deficient mice by deleting exon 2 and 3 of using CRISPR/Cas9 and compared the propensity of wild-type (WT) and mice to develop thrombosis using rose bengal and FeCl -induced carotid thrombosis, laser-induced cremaster arteriolar injury, and inferior vena cava (IVC) stasis models. We also compared tail bleeding times and assessed platelet activation in WT and mice in the absence and presence of exogenous β2GPI.

Necroptosis executioner MLKL plays pivotal roles in agonist-induced platelet prothrombotic responses and lytic cell death in a temporal order.

Necroptosis is a form of programmed cell death executed by receptor-interacting serine/threonine protein kinase 1 (RIPK1), RIPK3, and mixed lineage kinase domain-like (MLKL). Platelets are circulating cells that play central roles in haemostasis and pathological thrombosis. In this study we demonstrate seminal contribution of MLKL in transformation of agonist-stimulated platelets to active haemostatic units progressing eventually to necrotic death on a temporal scale, thus attributing a yet unrecognized fundamental role to MLKL in platelet biology.

Energy metabolism in platelets fuels thrombus formation: Halting the thrombosis engine with small-molecule modulators of platelet metabolism.

Platelets are circulating cells central to haemostasis that follows vessel injury, as well as thrombosis that ensues as a consequence of pathological stasis or plaque rupture. Platelet responses to various stimuli that mediate these processes are all energy-intensive. Hence, platelets need to adapt their energy metabolism to fulfil the requirements of clot formation while overcoming the adversities of the thrombus niche such as restricted access to oxygen and nutrient.

Fatty acid oxidation fuels agonist-induced platelet activation and thrombus formation: Targeting β-oxidation of fatty acids as an effective anti-platelet strategy.

Platelet mitochondria possess remarkable plasticity for oxidation of energy substrates, where metabolic dependency on glucose or fatty acids is higher than glutamine. Since platelets metabolize nearly the entire pool of glucose to lactate rather than fluxing through mitochondrial tricarboxylic acid cycle, we posit that majority of mitochondrial ATP, which is essential for platelet granule secretion and thrombus formation, is sourced from oxidation of fatty acids. We performed a comprehensive analysis of bioenergetics and function of stimulated platelets in the presence of etomoxir, trimetazidine and oxfenicine, three pharmacologically distinct inhibitors of β-oxidation.

Maternal serum irisin levels in normotensive and preeclamptic pregnancies: a systematic review and meta-analysis.

Background: Altered irisin levels have been reported in pregnancy-associated disorders, such as preeclampsia.

Objective: A systematic review and meta-analysis were conducted to evaluate the changes in maternal circulatory irisin levels in preeclampsia as compared to normotensive healthy pregnant controls.

Methods: Relevant studies were identified by searching PubMed and other databases.

D-dimer, disease severity, and deaths (3D-study) in patients with COVID-19: a systematic review and meta-analysis of 100 studies.

Hypercoagulability and the need for prioritizing coagulation markers for prognostic abilities have been highlighted in COVID-19. We aimed to quantify the associations of D-dimer with disease progression in patients with COVID-19. This systematic review and meta-analysis was registered with PROSPERO, CRD42020186661.

AMPK inhibition protects against arterial thrombosis while sparing hemostasis through differential modulation of platelet responses.

AMP-activated protein kinase (AMPK) is a metabolic master switch that has critical role in wide range of pathologies including cardiovascular disorders. As AMPK-α2 knockout mice exhibit impaired thrombus stability, we asked whether pharmacological inhibition of AMPK with a specific small-molecule inhibitor, compound C, could protect against arterial thrombosis without affecting hemostasis. Mice pre-administered with compound C exhibited decreased mesenteric arteriolar thrombosis but normal tail bleeding time compared to vehicle-treated animals.

Correction to: Plasma Fibrinogen Is a Natural Deterrent to Amyloid β-Induced Platelet Activation and Neuronal Toxicity.

Following publication of the original article [1], the author reported an error in Figure 1. The correct version of Figure 1 is as follows.

Platelet HIF-2α promotes thrombogenicity through PAI-1 synthesis and extracellular vesicle release.

Oxygen-compromised environments, such as high altitude, are associated with platelet hyperactivity. Platelets confined within the relatively impervious core of an aggregate/thrombus have restricted access to oxygen, yet they continue to perform energy-intensive procoagulant activities that sustain the thrombus. Studying platelet signaling under hypoxia is, therefore, critical to our understanding of the mechanistic basis of thrombus stability.

Aerobic glycolysis fuels platelet activation: small-molecule modulators of platelet metabolism as anti-thrombotic agents.

Platelets are critical to arterial thrombosis, which underlies myocardial infarction and stroke. Activated platelets, regardless of the nature of their stimulus, initiate energy-intensive processes that sustain thrombus, while adapting to potential adversities of hypoxia and nutrient deprivation within the densely packed thrombotic milieu. We report here that stimulated platelets switch their energy metabolism to aerobic glycolysis by modulating enzymes at key checkpoints in glucose metabolism.

Plasma Fibrinogen Is a Natural Deterrent to Amyloid Beta-Induced Platelet Activation.

Alzheimer's disease (AD) is a devastating neurodegenerative disorder, characterized by extensive loss of neurons, and deposition of amyloid beta (Aβ) in the form of extracellular plaques. Aβ is considered to have critical role in synaptic loss and neuronal death underlying cognitive decline. Platelets contribute to 95% of circulating amyloid-precursor protein that releases Aβ into circulation.

Cellular fibronectin containing extra domain A promotes arterial thrombosis in mice through platelet Toll-like receptor 4.

Cellular fibronectin containing extra domain A (Fn-EDA+), which is produced in response to tissue injury in several disease states, has prothrombotic activity and is known to interact with Toll-like-receptor 4 (TLR4). The underlying mechanism and cell types involved in mediating the prothrombotic effect of Fn-EDA+ still remain unknown. Using intravital microscopy, we evaluated susceptibility to carotid artery thrombosis after FeCl3-induced injury in mice expressing Fn lacking EDA (Fn-EDA(-/-) mice) or Fn containing EDA (Fn-EDA(+/+) mice).

Thrombospondin 1 requires von Willebrand factor to modulate arterial thrombosis in mice.

Thrombospondin 1 (TSP1) has been suggested as a counter receptor to platelet glycoprotein Ibα that supports initial platelet adhesion in absence of von Willebrand factor (VWF). Conversely, several other studies have shown that TSP1 interacts with VWF and may play a mechanistic role in modulating thrombosis. However, the in vivo evidence to support this mechanism remains unclear.

Amyloid β peptide stimulates platelet activation through RhoA-dependent modulation of actomyosin organization.

Platelets contribute to 95% of circulating amyloid precursor protein in the body and have widely been employed as a "peripheral" model of neurons in Alzheimer's disease. We sought to analyze the effects of amyloid β (Aβ) on platelets and to understand the underlying molecular mechanism. The Aβ active fragment containing amino acid sequence 25-35 (Aβ(25-35); 10-20 μM) was found to induce strong aggregation of human platelets, granule release, and integrin activation, similar to that elicited by physiological agonists.

Regulatory role of proteasome in determination of platelet life span.

Limit of platelet life span (8-10 days) is determined by the activity of a putative "internal clock" composed of Bcl-2 family proteins, whereas the role of other molecular players in this process remains obscure. Here, we sought to establish a central role of proteasome in platelet life span regulation. Administration of mice with inhibitors of proteasome peptidase activity induced significant thrombocytopenia.

Amine-modified graphene: thrombo-protective safer alternative to graphene oxide for biomedical applications.

Graphene and its derivatives have attracted significant research interest based on their application potential in different fields including biomedicine. However, recent reports from our laboratory and elsewhere have pointed to serious toxic effects of this nanomaterial on cells and organisms. Graphene oxide (GO) was found to be highly thrombogenic in mouse and evoked strong aggregatory response in human platelets.

Avocado fruit (Persea americana Mill) exhibits chemo-protective potentiality against cyclophosphamide induced genotoxicity in human lymphocyte culture.

Diets rich in fruits and vegetables have been associated with reduced risks for many types of cancers. Avocado (Persea americana Mill.) is a widely consumed fruit containing many cancer preventing nutrients, vitamins and phytochemicals.