Citation

Kokjohn TA, Maarouf CL, Daugs ID, Hunter JM, Whiteside CM, Malek-Ahmadi M, Rodriguez E, Kalback W, Jacobson SA, Sabbagh MN, Beach TG, Roher AE. J. Neurotrauma 2013; 30(11): 981-997.

Affiliation

Banner Sun Health Research Institute, The Longtine Center for Neurodegenerative Biochemistry, Sun City, Arizona, United States; tkokjo@midwestern.edu.

Copyright

(Copyright © 2013, Mary Ann Liebert Publishers)

DOI

10.1089/neu.2012.2699

PMID

23268705

Abstract

Dementia pugilistica (DP) is a suite of neuropathological and cognitive function declines following chronic traumatic brain injury (TBI) present in approximately 20% of retired boxers. Epidemiological studies indicate TBI is a risk factor for neurodegenerative disorders including Alzheimer's disease (AD) and Parkinson's disease (PD). Some biochemical alterations observed in AD and PD may be recapitulated in DP and other TBI subjects. In this report we investigate long-term biochemical changes in the brains of former boxers with neuropathogically confirmed DP. Our experiments revealed biochemical and cellular alterations in DP that are complementary to and extend information already provided by histological methods. ELISA and 1D- and 2D-Western blot techniques revealed differential expression of select molecules between 3 DP cases and 3 age-matched non-demented control (NDC) cases without a history of TBI. Structural changes such as disturbances in the expression and processing of glial fibrillary acidic protein, tau and α-synuclein were evident. The levels of the Aβ-degrading enzyme neprilysin were reduced in the DP cases. Amyloid-β levels were elevated in the DP subject with the concomitant diagnosis of AD. In addition, the levels of brain-derived neurotrophic factor and the axonal transport proteins kinesin and dynein were substantially decreased in DP relative to NDC subjects. Traumatic brain injury is a risk factor for dementia development and our findings are consistent with permanent structural and functional damage in the cerebral cortex and white matter of boxers. Understanding the precise threshold of damage required for the induction of pathology in DP and TBI is vital.

Language: en