Multiplexed Targeted Spatial Mass Spectrometry Imaging Assays to monitor lipids and NAD+ metabolites in CD38 knockout mice exhibiting improved metabolism.

Schurman, C. A.; Bons, J.; Kumaar, P. V.; Fang, J.; Hormazabal, G. V.; Roberts, A.; Riley, R. R.; Tao, N.; Verdin, E.; Schilling, B.

doi:10.1101/2025.05.25.655991

bioRxiv · 10.1101/2025.05.25.655991

Multiplexed Targeted Spatial Mass Spectrometry Imaging Assays to monitor lipids and NAD+ metabolites in CD38 knockout mice exhibiting improved metabolism.

Schurman, C. A.·Bons, J.·Kumaar, P. V.·Fang, J.·Hormazabal, G. V.·Roberts, A.·Riley, R. R.·Tao, N.·Verdin, E.·Schilling, B.

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Abstract

Mass spectrometry imaging (MSI) is a rapidly advancing technology that provides mapping of the spatial molecular landscape of tissues for a variety of analytes. Matrix-assisted laser desorption/ionization (MALDI)-MSI is commonly employed, however, confident in situ identification and accurate quantification of analytes remain challenging. We present a novel imaging methodology combining trapped ion mobility spectrometry (TIMS)-based parallel accumulation-serial fragmentation (PASEF) with MALDI ionization for targeted imaging parallel reaction monitoring (iprm-PASEF). We investigated the spatial distribution of lipids and metabolites in liver tissues from male wild-type and CD38 knockout mice (CD38-/-). CD38, an enzyme involved in nicotinamide adenine dinucleotide (NAD) metabolism, significantly influences liver metabolic function and contributes to age-related NAD decline. Although CD38 deletion previously was linked to improved metabolic phenotypes, the underlying spatial metabolic mechanisms are poorly understood. The spatial iprm-PASEF workflow enabled confident identification and differentiation of lipid isomers at the MS2 fragment ion level and confirmed increased NAD+ and decreased adenosine diphosphate ribose (ADPR), a by-product of NAD+ hydrolysis, in CD38-/- livers. This approach provided confident, specific, and robust MS2-based identification and quantification of fragment ions in spatial MSI experiments. Additionally, the innovative iprm-PASEF opens unprecedented opportunities for spatial metabolomics and lipidomics, offering spatially resolved insights into molecular mechanisms.

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Schurman, C. A., Bons, J., Kumaar, P. V., Fang, J., Hormazabal, G. V., Roberts, A., Riley, R. R., Tao, N., Verdin, E., Schilling, B.. 2025-05-26. Multiplexed Targeted Spatial Mass Spectrometry Imaging Assays to monitor lipids and NAD+ metabolites in CD38 knockout mice exhibiting improved metabolism.. https://doi.org/10.1101/2025.05.25.655991

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