Abstract

Background:
Neuroinflammation can be triggered by several causes, including traumatic brain injury (TBI) and exposure to toxicants such as chlorpyrifos (CPF), leading to chronic disabilities and substantial healthcare costs. Proteins such as CD59 and GMFB are implicated in various brain regulatory mechanisms. Investigating their roles can provide valuable insights into their role in pathologies such as TBI.

Aim:
This study aimed to analyze the molecular characteristics of the CD59 and gmfb genes and assess their relative gene expression in brain tissues of Piaractus orinoquensis subjected to brain injury using quantitative PCR (qPCR).

Methods:
Thirty Piaractus orinoquensis were allocated to brain injury or CFP exposure models. Brain injury was induced by telencephalic stab puncture, and CPF exposure was performed at a sublethal concentration of 0.011 µg/L. Brain regions, including the olfactory bulb, telencephalon, and optic chiasm, were collected at designated time points, and qPCR analysis was performed. CD59 and gmfb genes were sequenced and characterized using bioinformatic tools.

Results:
Both genes exhibited conserved features compared to other fish species. In the brain injury model, fish subjected to brain injury showed reduced expression of CD59 and gmfb compared to controls, suggesting a loss of immunomodulation associated with brain damage. Conversely, in the CPF-treated group, increased expression of CD59 in the olfactory bulb and gmfb in the optic chiasm was observed.

Conclusion:
CD59 downregulation after brain injury suggests a loss of immunomodulatory capacity following brain damage. In CPF-exposed fish, the overexpression of both CD59 and gmfb in some of the brain tissues demonstrated the capacity of the toxicant to generate region-specific immunoactivity and neurotoxicity in the brain.

Key words: Chlorpyrifos; QPCR; Red–bellied pacu; Traumatic brain injury.