Glycoprotein Ib clustering in platelets can be inhibited by α-linolenic acid as revealed by cryo-electron tomography

Abstract

Platelet adhesion to the sub-endothelial matrix and damaged endothelium occurs through a multi-step process mediated in the initial phase by glycoprotein Ib binding to von Willebrand factor, which leads to the subsequent formation of a platelet plug. The plant-derived omega-3 fatty acid alpha-linolenic acid is an abundant alternative to fish-derived n-3 FA and has antiinflammatory and anti-thrombotic properties. In this study, we investigated the impact of alpha-linolenic acid on human platelet binding to vWF under high-shear flow conditions (mimicking blood flow in stenosed arteries). Pre-incubation of fresh human blood from healthy donors with alpha-linolenic acid at dietary relevant concentrations reduced platelet binding and rolling on vWF-coated microchannels at a shear rate of 100 dyn/cm 2. Depletion of membrane cholesterol by incubation of platelet-rich-plasma with methyl-beta cyclodextrin abrogated platelet rolling on vWF. Analysis of glycoprotein Ib by applying cryo-electron tomography to intact platelets revealed local clusters of glycoprotein Ib complexes, upon shear-force exposure, whose formation could be prevented by alpha-linolenic acid treatment. This study provides novel findings on the rapid local rearrangement of the glycoprotein Ib complexes in response to high-shear flow and highlights the mechanism of in vitro inhibition of platelet binding to and rolling on vWF by alpha-linolenic acid.

Lifelong dietary omega-3 fatty acid suppresses thrombotic potential through gut microbiota alteration in aged mice

“…Indeed, lifelong dietary ALA decreased some genera belonging to the phyla Proteobacteria including Desulfovibrio and Firmicutes including Clostridia_VadinBB60 group , which both are known to be positively associated with inflammatory responses during aging process ( Fu et al., 2020 ; Zou et al., 2020 ; Burrello et al., 2018 ; Conley et al., 2016 ). Based on the current findings that a lifelong high ALA diet could decrease plasma TMAO levels within old mice and on our previous studies showing that ALA interferes with clustering of GPIb receptors on platelet surface under high-shear rates ( Stivala et al., 2020 ), we indicate that ALA may modulate both directly, via amelioration of platelet reactivity and adhesion to vWF and decrease in procoagulant factors, and indirectly, via the reduction of TMAO production and inflammatory cytokines and increase in SCFA acetate.…”

“…Impedance platelet aggregometry assays were performed as previously described ( Stivala et al., 2020 ). In brief, whole blood was collected from old (>18-month-old) or young (2-3-month-old) mice under different treatments using sodium citrate (0.109 M).…”

“…Microfluidic shear flow experiments were performed using the Bioflux Microfluidics System (Fluxion Biosciences, San Francisco, CA, USA) ( Stivala et al., 2020 ). Each micro channel of a 24-well plate was coated with human vWF (100 ug/ml, Hematologic Technologies Inc., USA) and placed at room temperature for 1 hr.…”

“…Short-chain, plant-derived omega-3 poly-unsaturated fatty acid (PUFA), alpha-linolenic acid (ALA, 18:3 n-3) have been claimed for health benefits — to prevent cardiometabolic diseases and thrombotic events — which are supported by evidence from experimental and clinical trials ( Bonetti et al, 2021 ; Reiner et al., 2017 ; Stivala et al., 2013 ). Our recent findings have demonstrated the beneficial anti-platelet effects of a diet supplemented with ALA on in vivo mouse models of arterial thrombosis and atherosclerosis ( Stivala et al., 2020 ; Winnik et al., 2011 ; Holy et al., 2011 ). PUFA-rich diet counteracts inflammation and protects healthy metabolic state ( Caesar et al., 2015 ; Oh et al., 2010 ; Calder, 2006 ), whereas saturated fatty acids promote inflammatory responses in diverse organs, leading to metabolic diseases ( Kennedy et al., 2009 ).…”

The Omega-3 Fatty Acid Eicosapentaenoic Acid (EPA) Correlates Inversely with Ischemic Brain Infarcts in Patients with Atrial Fibrillation

“…ALA was not associated with the prevalence of LNCCIs or markers of small vessel disease. Previous studies reported that ALA improved endothelial function [ 30 ], reduced vascular inflammation [ 12 ], and inhibited platelet adhesion and aggregation [ 31 , 32 ]. The well-described anti-inflammatory and anti-thrombotic effects in vitro and in rodents, however, did not translate to significant clinical results.…”