Desorption Electrospray Ionization Cyclic Ion Mobility-Mass Spectrometry Imaging for Traumatic Brain Injury Spatial...

Area of Science:

• * Biochemistry and Molecular Biology
• * Neuroscience
• * Analytical Chemistry

Background:

• * Lipidomics is crucial for understanding metabolic processes and disease pathology.
• * Lipid structural diversity and isobaric/isomeric species pose identification challenges, especially in mass spectrometry imaging (MSI).
• * Ion mobility (IM) is emerging as a solution to enhance MSI capabilities.

Purpose of the Study:

• * To evaluate desorption electrospray ionization cyclic ion mobility mass spectrometry (DESI cIM MSI) for traumatic brain injury (TBI) rat brain studies.
• * To assess the impact of multiple passes in the ion mobility cell on data quality and lipid identification.
• * To identify novel lipid alterations and metabolic changes associated with TBI.

Main Methods:

• * Pilot MSI study on rat brains subjected to TBI.
• * Utilized DESI cIM MSI with one and six passes through the cyclic ion mobility cell.
• * Analyzed lipid profiles and metabolite changes, focusing on phosphoinositides, NAD, and adenine metabolites.

Main Results:

• * Increasing ion mobility passes enhanced resolving power and isobaric lipid resolution, creating more specific brain maps.
• * Drift time data revealed multiply charged phosphoinositide species, previously unreported in TBI MSI studies.
• * Observed decreased phosphoinositides in the hippocampus, reduced NAD, and altered adenine metabolites post-TBI.

Conclusions:

• * DESI cIM MSI effectively improves lipid identification and spatial mapping in TBI studies.
• * Identified novel lipid changes, including decreased phosphoinositides, suggesting altered enzymatic activity and inflammation post-TBI.
• * Confirmed significant disruption of brain energy metabolism following TBI, evidenced by NAD and adenine metabolite alterations.