Abstract
Background: Alzheimer’s disease (AD) and progressive supranuclear palsy (PSP) are examples of neurodegenerative diseases, characterized by abnormal tau inclusions, that are called tauopathies. AD is characterized by highly insoluble paired helical filaments (PHFs) composed of tau with abnormal post-translational modifications. PSP is a neurodegenerative disease with pathological and clinical heterogeneity. There are six tau isoforms expressed in the adult human brain, with repeated microtubule-binding domains of three (3R) or four (4R) repeats. In AD, the 4R:3R ratio is 1:1. In PSP, the 4R isoform predominates. The lesions in PSP brains contain phosphorylated tau aggregates in both neurons and glial cells. Objective: Our objective was to evaluate and compare the processing of pathological tau in PSP and AD. Methods: Double and triple immunofluorescent labeling with antibodies to specific post-translational tau modifications (phosphorylation, truncation, and conformational changes) and thiazin red (TR) staining were carried out and analyzed by confocal microscopy. Results: Our results showed that PSP was characterized by phosphorylated tau in neurofibrillary tangles (NFTs) and glial cells. Tau truncated at either Glu391 or Asp421 was not observed. Extracellular NFTs (eNFTs) and glial cells in PSP exhibited a strong affinity for TR in the absence of intact or phosphorylated tau. Conclusion: Phosphorylated tau was as abundant in PSP as in AD. The development of eNFTs from both glial cells and neuronal bodies suggests that truncated tau species, different from those observed in AD, could be present in PSP. Additional studies on truncated tau within PSP lesions could improve our understanding of the pathological processing of tau and help identify a discriminatory biomarker for AD and PSP.
| Original language | English |
|---|---|
| Pages (from-to) | 1517-1531 |
| Number of pages | 15 |
| Journal | Journal of Alzheimer's Disease |
| Volume | 79 |
| Issue number | 4 |
| Early online date | 15 Jan 2021 |
| DOIs | |
| Publication status | Published - 16 Feb 2021 |
Bibliographical note
ACKNOWLEDGMENTSThis work was supported by Fondo Nacional de Ciencia y Tecnologia, FONDOCyT, from the Ministry of Higher Education, Science and Technology, Dominican Republic (2015-3A2-127 to MP-H) and (2018-2019-2A3-208 to JL-M and MP-H). The authors want to express their gratitude to the following: Dr. P. Davies† (Albert Einstein College of Medicine, Bronx, NY, USA) and Lester I. Binder† (North Western, Chicago, IL, USA) for the generous gift of mAbs TG–3 and Alz–50, and Tau–1, Tau–5 and Tau–7, respectively; Tec. Amparo Viramontes Pintos for the handling of the brain tissue; support in the confocal microscopy unit of CIIDIR Durango, Instituto Politecnico Nacional; Union Medica Uni-
A. Mart´ınez-Maldonado et al. / Molecular Processing of Tau Protein in Progressive Supranuclear Palsy 1529 versity Clinic, Dominican Republic, for their support and collaboration in the development of this research project. We also want to express our gratitude to the Mexican families who have donated the brain of their loved ones affected with Alzheimer’s disease and
made our research possible. This work is dedicated to the memory of Professor Dr. Jose Ra ´ ul Mena L ´ opez ´ †. †Deceased. Authors’ disclosures available online (https://
www.j-alz.com/manuscript-disclosures/20-1139r2).
Keywords
- Alzheimer’s disease
- neurofibrillary tangle
- progressive supranuclear palsy
- tau protein
- truncation
- Alzheimer's disease
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© 2021 – The authors. Published by IOS Press. This is an Open Access article distributed under the terms of the Creative Commons Attribution-NonCommercial License (CC BY-NC 4.0).