Virginia Research Day 2025

Medical Student Research Biomedical

15 Spinal Cord Concussion: Local and Systemic Analysis of Neuronal Biomarkers

Taylor Dickson 1 ; Anastasiya Loos 1 ; Josiah Thomas 1 ; Tamir Abbasi 1 ; Helen Zak 1 ; Carly Norris 2 ; Susan Murphy 2 ; Pamela VandeVord 2 ; Kelly Roballo 2 ; Juliana Lopez-Vivas 3 Corresponding author: tdickson@vt.vcom.edu

1 Edward Via College of Osteopathic Medicine - Virginia Campus 2 Virginia Tech Biomedical Engineering and Mechanics, Blacksburg, VA 3 Virginia Tech College of Science, Blacksburg, VA Protein homeostasis (proteostasis) is paramount for cell regulation. An imbalance of proteostasis can cause a build-up of misfolded and irregular proteins, that can impair the proper function of the cell. The accumulation of these proteins is associated with injury. Two of the systems responsible for this integral regulation are the ubiquitin-proteasome system and the lysosome/autophagy proteolytic system. Ubiquitin C-Terminal Hydrolase L1 (UCH-L1), a member of deubiquitinating enzymes expressed in the central nervous system, has been a broadly used neuronal biomarker for determining the extent of brain concussions in humans. The level of this biomarker has been found to correlate to damage severity of the brain. While the concept of looking at the neuronal biomarkers after brain concussion is familiar, analysis of spinal cord cell culture is novice and will provide depth into the understanding of the clinical use of these biomarkers for determining injury extent and identifying targets for clinical intervention. The goal of this study was to analyze UCH-L1, among other potential biomarkers and cytokines, over time in rat

spinal cord cell culture and plasma to compare local and systemic response after the rats have sustained a spinal cord injury classified as a mild injury or concussion. For that, we used male rats with 250 300g with 8 animals per group which include sham group, no injured animals, and injured, animals that have experienced blunt, isolated, spinal cord trauma. All procedures performed in this project received IACUC approval (# 22-182) and followed all laboratory animal guidelines and ethical procedures. At 24 hours or 72 hours post injury, animals were euthanized following all the animal guidelines, and spinal cords were isolated for cell culture and the rat’s plasma was retrieved. Spinal cord cells were seeded at the concentration of 300,000 cells in 1 mL of basal medium in a coated plate and cultured for 48 hours. After this period, media from the cell culture were isolated and used to evaluate the injury level and tissue response to the injury based on biomarker concentrations quantified by ELISA. The general markers measured were UCH-L1, VEGF, Nitrous

Oxide, GFAP, and Cortisol. The results show increase of UCH-L1 in injured animals in the cell culture media and plasma, as both a local and systemic marker indicating that there was an injury affecting CNS, while cortisol was more of a systemic marker, with an increase in injured animal in the plasma only. VEGF shows a local response rather than systemic. Lastly, NO shows a local response, most notably after 72 hours. Nitrous Oxide was selected as a marker to indicate oxidative stress, a component of chronic neuroinflammation caused be each of these markers. From our results, UCH-L1 is particularly useful for clinical application due to its local and systemic presence. This data shows that UCH-L1 is not solely a marker for brain concussion, but also a marker of spinal cord concussion in this model of isolated spinal cord blunt trauma. Our results provide a foundation for growth and discovery within the field of spinal cord concussion and revolutionizing clinical testing for this group of injuries.

80