Spatial lipidomics maps brain alterations associated with mild traumatic brain injury

Area of Science:

• Neuroscience
• Biochemistry
• Pathology

Background:

• Traumatic brain injury (TBI) is a significant global health issue, with mild (mTBI) and repetitive mild (rmTBI) forms being common.
• The underlying pathologies of mTBI and rmTBI, particularly brain lipid dysregulation, remain largely unclear.

Purpose of the Study:

• To investigate brain region-specific lipid alterations following mild traumatic brain injury.
• To identify novel lipid biomarkers associated with mTBI and rmTBI pathology.

Main Methods:

• Development of a non-targeted spatial lipidomics workflow using high-resolution mass spectrometry imaging in a rat model.
• Application of discriminant multivariate models to analyze lipid changes in the hippocampus, cortex, and corpus callosum.

Main Results:

• A multivariate model accurately differentiated injured from sham rat brains using only four lipid species, achieving an AUC of 0.99 for the hippocampus.
• Key discriminant lipid classes included phosphatidylcholines (PC) and lysophosphatidylcholines (LPC), particularly those containing polyunsaturated fatty acids and LPC-plasmalogens (LPC-P).
• Several identified altered lipids, including specific PC and LPC-P species, have not been previously linked to mTBI.

Conclusions:

• Observed lipid alterations suggest neuroinflammation and oxidative stress are key pathological mechanisms in rmTBI.
• These findings highlight potential therapeutic targets for mitigating persistent damage and cognitive deficits after mild brain injuries.