Multiple Infusion Start Time Mass Spectrometry Imaging of Dynamic SIL-Glutathione Biosynthesis Using Infrared...

Area of Science:

• Metabolomics
• Biochemistry
• Analytical Chemistry

Background:

• Glutathione metabolism is closely linked to various disease states.
• Understanding glutathione kinetics and microenvironmental influences is crucial for disease research.

Purpose of the Study:

• To develop and apply an analytical technique for studying spatial changes in glutathione kinetics.
• To investigate the impact of microenvironmental factors on glutathione metabolism.

Main Methods:

• Combined multiple infusion start time protocol with stable isotope labeling.
• Utilized infrared matrix-assisted laser desorption electrospray ionization and high-resolution accurate mass-mass spectrometry imaging.
• Developed a tool in MSiReader to compute percent isotope enrichment (PIE) and visualize data.

Main Results:

• Successfully mapped the metabolism of stable isotope-labeled glycines into glutathione isotopologues in mouse liver tissue.
• Quantified isotopic enrichment of glutathione with median values of 1.6%, 1.8%, and 1.5% for different labels.
• Visualized spatial distribution of glutathione flux using heat-maps.

Conclusions:

• The developed method enables detailed spatial analysis of glutathione kinetics.
• This technique can be adapted to study glutathione flux heterogeneity in diseased versus healthy tissues.
• Provides a new tool for understanding the role of glutathione in disease pathogenesis.