Walford, T, Musa, FI and Harper, AGS (2015) Nicergoline inhibits human platelet Ca2+ signalling through triggering a microtubule-dependent reorganisation of the platelet ultrastructure. British Journal of Pharmacology, 173 (1). pp. 234-247.

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A Harper - Nicergoline Supplementary Material.pdf - Accepted Version

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A Harper - Nicergoline inhibits human platelet Ca2+ signalling through triggering a microtubule-dependent reorganisation of the platelet ultrastructure.pdf - Accepted Version

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Abstract

BACKGROUND AND PURPOSE:
Recently, we demonstrated that a pericellular Ca(2+) recycling system potentiates agonist-evoked Ca(2+) signalling and granule secretion in human platelets and hypothesized a role for the membrane complex (MC) in orchestrating the accumulation of Ca(2+) in the pericellular region. Previous work has demonstrated that treatment with high concentrations of nicergoline may disrupt the MC through an ability to trigger a re-organization of the dense tubular system. Experiments were therefore performed to assess whether nicergoline-induced changes in platelet ultrastructure affects thrombin-evoked Ca(2+) fluxes and dense granule secretion.

EXPERIMENTAL APPROACH:
Thrombin-evoked Ca(2+) fluxes were monitored in Fura-2- or Fluo-5N-loaded human platelets, or using platelet suspensions containing Fluo-4 or Rhod-5N K(+) salts. Fluorescence microscopy was utilized to monitor microtubule structure and intracellular Ca(2+) store distribution in TubulinTracker- and Fluo-5N-loaded platelets respectively. Dense granule secretion was monitored using luciferin-luciferase.

KEY RESULTS:
Nicergoline treatment inhibited thrombin-evoked Ca(2+) signalling and induced alterations in the microtubule structure and the distribution of intracellular Ca(2+) stores in platelets. Nicergoline altered the generation and spreading of thrombin-induced pericellular Ca(2+) signals and almost completely prevented dense granule secretion. Stabilization of microtubules using taxol reversed most effects of nicergoline on platelet Ca(2+) signalling and partially reversed its effects on dense granule secretion.

CONCLUSIONS AND IMPLICATIONS:
Nicergoline-induced alterations to platelet ultrastructure disrupt platelet Ca(2+) signalling in a manner that would be predicted if the MC had been disrupted. These data suggest that nicergoline may be a useful prototype for the discovery of novel MC-disrupting anti-thrombotics.

Item Type: Article
Subjects: Q Science > Q Science (General)
Divisions: Faculty of Medicine and Health Sciences > Institute for Science and Technology in Medicine
Depositing User: Symplectic
Date Deposited: 14 Oct 2015 10:28
Last Modified: 23 Apr 2019 11:32
URI: http://eprints.keele.ac.uk/id/eprint/1028

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