Proteomic Profiling of Mouse Brains Exposed to Blast-Induced Mild Traumatic Brain Injury Reveals Changes in Axonal Proteins and Phosphorylated Tau

Article type: Research Article

Authors: Chen, Mei^{a; b; 1} | Song, Hailong^{c; 1} | Cui, Jiankun^{c; e} | Johnson, Catherine E.^d | Hubler, Graham K.^f | DePalma, Ralph G.^g | Gu, Zezong^{c; e; *} | Xia, Weiming^{a; h; *}

Affiliations: [a] Geriatric Research Education and Clinical Center, Office of Research and Development, Edith Nourse Rogers Memorial Veterans Hospital, Bedford, MA, USA | [b] Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, MA, USA | [c] Department of Pathology & Anatomical Sciences, University of Missouri School of Medicine, Columbia, MO, USA | [d] Department of Mining and Nuclear Engineering, Missouri University of Science and Technology, Rolla, MO, USA | [e] Truman VA Hospital Research Service, Columbia, MO, USA | [f] Sidney Kimmel Institute for Nuclear Renaissance, Department of Physics and Astronomy, University of Missouri, Columbia, MO USA | [g] Office of Research and Development, Department of Veterans Affairs, Washington, DC, USA Department of Surgery, Uniformed University of the Health Science, Bethesda, MD, USA | [h] Department of Pharmacology and Experimental Therapeutics, Boston University School of Medicine, Boston, MA, USA

Correspondence: [*] Correspondence to: Zezong Gu, MD, PhD, Department of Pathology & Anatomical Sciences, Center for Translational Neuroscience, University of Missouri-Columbia, School of Medicine, Columbia, MO 65212, USA. Tel.: 573-884-3880; Fax: 573-884-4612; E-mail: guze@health.missouri.edu and Weiming Xia, PhD, Building 70, Room 202, Geriatric Research Education and Clinical Center, Edith Nourse Rogers Memorial Veterans Hospital, Bedford, MA 01730, USA. Tel.: +1 781 687 2852; Fax: +1 781 687 3463; E-mail: weiming.xia@va.gov.

Note: [1] These authors contributed equally to this work.

Abstract: Alzheimer’s disease (AD), the most prevalent form of dementia, is characterized by two pathological hallmarks: Tau-containing neurofibrillary tangles and amyloid-β protein (Aβ)-containing neuritic plaques. The goal of this study is to understand mild traumatic brain injury (mTBI)-related brain proteomic changes and tau-related biochemical adaptations that may contribute to AD-like neurodegeneration. We found that both phosphorylated tau (p-tau) and the ratio of p-tau/tau were significantly increased in brains of mice collected at 3 and 24 h after exposure to 82-kPa low-intensity open-field blast. Neurological deficits were observed in animals at 24 h and 7 days after the blast using Simple Neuroassessment of Asymmetric imPairment (SNAP) test, and axon/dendrite degeneration was revealed at 7 days by silver staining. Liquid chromatography-mass spectrometry (LC-MS/MS) was used to analyze brain tissue labeled with isobaric mass tags for relative protein quantification. The results from the proteomics and bioinformatic analysis illustrated the alterations of axonal and synaptic proteins in related pathways, including but not being limited to substantia nigra development, cortical cytoskeleton organization, and synaptic vesicle exocytosis, suggesting a potential axonal damage caused by blast-induced mTBI. Among altered proteins found in brains suffering blast, microtubule-associated protein 1B, stathmin, neurofilaments, actin binding proteins, myelin basic protein, calcium/calmodulin-dependent protein kinase, and synaptotagmin I were representative ones involved in altered pathways elicited by mTBI. Therefore, TBI induces elevated phospho-tau, a pathological feature found in brains of AD, and altered a number of neurophysiological processes, supporting the notion that blast-induced mTBI as a risk factor contributes to AD pathogenesis. LC/MS-based profiling has presented candidate target/pathways that could be explored for future therapeutic development.

DOI: 10.3233/JAD-180726

Journal: Journal of Alzheimer's Disease, vol. 66, no. 2, pp. 751-773, 2018