IMR Press / FBL / Volume 27 / Issue 5 / DOI: 10.31083/j.fbl2705153
Open Access Original Research
Platelet TAU is Associated with Changes in Depression and Alzheimer's Disease
Show Less
1 Protein Core Facility, Institute of Medical Biochemistry, Biocenter, Medical University of Innsbruck, 6020 Innsbruck, Austria
2 Laboratory of Psychiatry and Experimental Alzheimer’s Research, Medical University of Innsbruck, 6020 Innsbruck, Austria
3 Department of Psychiatry and Psychotherapy A, Hall State Hospital, 6060 Hall in Tirol, Austria
*Correspondence: (Christian Humpel)
Academic Editors: Fabio Moda and Giorgio Giaccone
Front. Biosci. (Landmark Ed) 2022, 27(5), 153;
Submitted: 1 March 2022 | Revised: 4 April 2022 | Accepted: 22 April 2022 | Published: 12 May 2022
Copyright: © 2022 The Author(s). Published by IMR Press.
This is an open access article under the CC BY 4.0 license.

Background: Platelets (thrombocytes) are small anuclear cells that play an important role in blood clotting. They are activated and dysfunctional in brain disorders, such as Alzheimer’s disease (AD) and depression. Platelets express the amyloid-precursor protein (APP) and release beta-amyloid40 into the blood. Recent evidence reports that platelets also express the microtubule-associated protein tau. In this study, we further characterized the molecular appearance of tau and examined its alterations in patients with neurocognitive impairment. Methods: Platelets were isolated from patients with AD, mild cognitive impairment (MCI) or depression and compared to healthy controls. Subsequently, FACS analysis was employed to characterize platelets for platelet surface P-selectin (CD62P). In order to enhance the detection levels, samples were pooled (15 samples per group) and analyzed by Lumipulse Assay, Western blots, and mass spectrometry. Results: Tau is expressed in human platelets and tau levels were decreased in platelets isolated from patients with AD and depression. Additionally, phospho-tau-181 was slightly increased in patients with depression. We show that tau is highly fragmented (20–40 kDa) in the platelet extracts using Western blot analysis. The mass spectrometry data did not show a clear identification of tau in the pooled platelet samples. Conclusions: Our data reveal that tau is found in platelets, possibly in a highly fragmented form. Tau levels may be used as a potential diagnostic approach to differentiate AD and depression from healthy controls.

mass spectrometry
Fig. 1.
Back to top