Review
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World J Psychiatr. Mar 22, 2016; 6(1): 84-101
Published online Mar 22, 2016. doi: 10.5498/wjp.v6.i1.84
Are the changes in the peripheral brain-derived neurotrophic factor levels due to platelet activation?
Montserrat Serra-Millàs
Montserrat Serra-Millàs, Osona Mental Health, Hospital Universitari de Vic, Salut Mental i Innovació Social (SaMIS), Universitat de Vic-Universitat Central de Catalunya, 08500 Vic, Barcelona, Spain
Author contributions: Serra-Millàs M solely contributed to this manuscript.
Conflict-of-interest statement: The author reports no conflicts of interest in this work.
Open-Access: This article is an open-access article which was selected byan in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Correspondence to: Montserrat Serra-Millàs, PhD, Osona Mental Health, Hospital Universitari de Vic, Salut Mental i Innovació Social (SaMIS), Universitat de Vic-Universitat Central de Catalunya, C/Francesc Pla «El Vigatà» nº 1, 08500 Vic, Barcelona, Spain. serra2mont@yahoo.es
Telephone: +34-93-8831111 Fax: +34-93-7027786
Received: August 28, 2015
Peer-review started: September 4, 2015
First decision: September 28, 2015
Revised: December 24, 2015
Accepted: January 21, 2016
Article in press: January 22, 2016
Published online: March 22, 2016
Abstract

Brain-derived neurotrophic factor (BDNF) plays an important role in central nervous system development, neurogenesis and neuronal plasticity. BDNF is also expressed in several non-neuronal tissues, and it could play an important role in other processes, such as cancer, angiogenesis, etc. Platelets are the major source of peripheral BDNF. However, platelets also contain high amounts of serotonin; they express specific surface receptors during activation, and a multitude of pro-inflammatory and immunomodulatory bioactive compounds are secreted from the granules. Until recently, there was insufficient knowledge regarding the relationship between BDNF and platelets. Recent studies showed that BDNF is present in two distinct pools in platelets, in α-granules and in the cytoplasm, and only the BDNF in the granules is secreted following stimulation, representing 30% of the total BDNF in platelets. BDNF has an important role in the pathophysiology of depression. Low levels of serum BDNF have been described in patients with major depressive disorder, and BDNF levels increased with chronic antidepressant treatment. Interestingly, there is an association between depression and platelet function. This review analyzed studies that evaluated the relationship between BDNF and platelet activation and the effect of treatments on both parameters. Only a few studies consider this possible confounding factor, and it could be very important in diseases such as depression, which show changes in both parameters.

Keywords: Platelets, Brain derived neurotrophic factor, Depression, Antidepressants, Biomarkers

Core tip: Brain-derived neurotrophic factor (BDNF) is expressed in neuronal and non- neuronal tissues and is stored peripherally in platelets. Platelet BDNF is present in α-granules and cytoplasm and only BDNF of granules is released by agonist stimulation. Little is known about mechanisms related to BDNF release in human platelets. Depressive disorders are associated with BDNF and platelet dysfunction. Low levels of serum BDNF have been described in major depression and they increased with antidepressant treatment. Only a few studies have evaluated the relationship between platelet activation and peripheral BDNF values. This review suggests that platelet reactivity may partly explain the alterations in BDNF.