Biomarkers Track Damage after Graded Injury Severity in a Rat Model of Penetrating Brain Injury

Abstract The goal of this project was to determine whether biochemical markers of brain damage can be used to diagnose and assess the severity of injury in a rat model of penetrating ballistic-like brain injury (PBBI). To determine the relationship between injury magnitude and biomarker levels, rats underwent three discrete PBBI severity levels defined by the magnitude of the ballistic component of the injury, calibrated to equal 5%, 10%, or 12.5% of total rat brain volume. Cortex, cerebrospinal fluid (CSF), and blood were collected at multiple time points. Levels of three biomarkers (αII-spectrin breakdown product [SBDP150], glial fibrillary acidic protein [GFAP], and ubiquitin C-terminal hydrolase-L1 [UCH-L1]), were measured using quantitative immunoblotting and/or enzyme-linked immunosorbent assays. In injured cortex, SBDP150 and GFAP levels were increased significantly over controls. Cortical SBDP150 was elevated at 1 day but not 7 days, and GFAP at 7 days but not 1 day. At their respective time point...