Spatial Lipidomics Maps Brain Alterations Associated with Mild Traumatic Brain Injury.

Area of Science:

• Neuroscience
• Biochemistry
• Mass Spectrometry Imaging

Background:

• Traumatic brain injury (TBI), particularly mild (mTBI) and repetitive (rmTBI) forms, is a significant global health issue affecting millions annually.
• The underlying pathologies of mTBI and rmTBI remain incompletely understood, with limited data on brain lipid alterations post-injury.

Approach:

• Developed a non-targeted spatial lipidomics workflow using ultrahigh-resolution mass spectrometry imaging to map brain lipid changes in rats after injury.
• Utilized discriminant multivariate models for specific brain regions (hippocampus, cortex, corpus callosum) to identify lipid species differentiating injured from sham animals.

Key Points:

• A hippocampal model accurately differentiated injured tissue (AUC=0.994) using only four lipid species.
• Discriminant lipid classes included phosphatidylcholines (PC), lysophosphatidylcholines (LPC), and LPC-plasmalogens (LPC-P), many containing polyunsaturated fatty acids.
• Several identified altered lipid species, particularly PC and LPC-P, have not been previously linked to mTBI.

Conclusions:

• Observed lipid alterations suggest neuroinflammation, oxidative stress, and sodium-potassium pump dysfunction as key pathologies in rmTBI.
• These pathologies may explain cognitive deficits associated with rmTBI.
• Targeting these identified pathologies could offer therapeutic benefits for mitigating persistent damage after mild brain injuries.