Matrix-Assisted Laser Desorption/Ionization-Mass Spectrometry Imaging of Lipids in Experimental Model of Traumatic Brain Injury Detecting Acylcarnitines as Injury Related Markers

Identifying new lipid markers linked to traumatic brain injury (TBI) is of major importance in characterizing their central role in the regeneration process and inflammatory response in such an injury model. In the present study, an advanced lipidomics analysis using high spectral resolution matrix-assisted laser desorption/ionization-mass spectrometry imaging was performed on different brain regions in an experimental rat model of moderate controlled cortical impact (CCI) while considering different time points (1 day, 3 days, 7 days, and 10 days) assessing the acute and subacute phase after injury. Our results revealed a new family of lipids, the acylcarnitines, as TBI-lipid related markers, with maximum expression at 3 days after impact and main colocalization within resident microglia of the brain. Furthermore, our experiments highlighted the upregulation of these acylcarnitine lipids, secreted by microglia, in the ipsilateral substantia nigra, the main region in the brain affected in Parkinson’s disease (PD).