Colchicine reduces platelet aggregation by modulating cytoskeleton rearrangement via inhibition of cofilin and LIM domain kinase 1
Authors: Francesco S Loffredo
Stefano Conte
Giovanni Cimmino
Gaetano Calì
Bruno Trimarco
Grazia Pellegrino
Andrea Morello
Nicola De Luca
Roberta Tarallo
Plinio Cirillo
Paolo Golino
Journal: Vascular pharmacology (2018)
Discipline: PHARMACOLOGY & TOXICOLOGY
Keywords: Colchicine; Cytoskeleton; Platelets.
Affiliations: Department of Cardiothoracic and Respiratory Sciences, Section of Cardiology, University of Campania "Luigi Vanvitelli", Naples, Italy., Laboratory of Molecular Medicine and Genomics, Department of Medicine, Surgery and Dentistry "Schola Medica Salernitana", University of Salerno, Baronissi, SA, Italy., Department of Advanced Biomedical Sciences, Division of Cardiology, University of Naples "Federico II", Naples, Italy., Molecular Cardiology, International Centre for Genetic Engineering and Biotechnology, Trieste, Italy; Cardiovascular Department, Ospedale Riuniti and University of Trieste, Trieste, Italy., Department of Molecular Medicine, Medical Biotechnologies University "Federico II", Naples, Italy; Endocrinology and Experimental Oncology Institute, CNR, Naples, Italy., Department of Advanced Biomedical Sciences, Division of Cardiology, University of Naples "Federico II", Naples, Italy. Electronic address: .

Abstract:  Introduction: Platelets activation/aggregation with subsequent thrombus formation is the main event in the pathophysiology of acute coronary syndrome. Once activated, platelets show an extensive cytoskeleton rearrangement that leads to recruitment of additional platelets to finally cause haemostatic plug formation. Thus, the cytoskeleton plays a pivotal role in this phenomenon. Colchicine (COLC) is an anti-inflammatory drug proven to reduce major cardiovascular events in patients with coronary artery disease. The molecular mechanisms by which COLC exerts these protective effects remain partially still unknown. Since COLC causes disruption of tubulin, a component of cell cytoskeleton, we investigated whether this drug might interfere with platelet aggregation by acting on cytoskeleton rearrangement. Methods and results: Platelets isolated from healthy volunteers were activated with Adenosine Diphosphate (ADP, 20 μM) Collagen (COLL, 60 μg/ml) and Thrombin Activating Receptor Peptide (TRAP 25 μM) with/without COLC 10 μM pretreatment. After stimulus, aggregation was measured by light aggregometry overtime. Microtubules structure was assessed by immunohistochemistry and key proteins involved in regulation of actin-filament assembly and contractility such as Myosin Phosphatase Targeting subunit (MYPT), LIM domain kinase 1(LIMK1) and cofilin were evaluated by Western Blot analysis. Colchicine pretreatment significantly blunted ADP/COLL/TRAP-induced platelet aggregation (up to 40%). COLC effects appeared mediated by microtubules depolymerization and cytoskeleton disarrangement associated to inactivation of MYPT and LIMK1 that finally interfered with cofilin activity. Conclusions: Our data indicate that colchicine exerts anti-platelet effects in vitro via inhibition of key proteins involved in cytoskeleton rearrangement, suggesting that its beneficial cardiovascular properties may be due, at least in part, to an inhibitory effect of platelet activity. 

Retracted: No

PubPeer comments:
 Several questions arising from this paper. 1. The effects of colchicine on human platelet microtubules was examined via electron microscopy by James White and reported in 1969 in the American Journal of Pathology. Can the authors explain why this seminal work was not cited? 2. The effects of colchicine on platelet aggregation and secretion were well known by 1980 from several published studies, including Menche et al. in Journal of Clinical Investigation in 1980. Why is none of this prior work cited here? 3. The present paper presents several immunoblots purporting to show the effects of various treatments on phosphorylation of assorted platelet proteins. Can the author explain why there are such clear differences in the band patterns shown from what are described as multiple probings of the same blots? ![file] 4. Figure 7 is described as showing confocal immunofluorescence microscopy of platelets under various conditions that is meant to indicate the status of the platelet cytoskeletal tubulin ring. However, the images shown provide almost no insights into the morphology of that structure under any set of conditions. ![file] ,