Spatial Profiling of Glycosaminoglycans (GAGomics) From Laser Microdissected Mouse Brain

Area of Science:

• Biochemistry
• Analytical Chemistry
• Neuroscience

Background:

• Glycosaminoglycans (GAGs), including heparan sulfate (HS) and chondroitin sulfate (CS), are crucial for cellular functions but challenging to analyze due to their heterogeneity.
• Current structural analysis of HS and CS is limited to bulk tissues, hindering spatially resolved insights.

Purpose of the Study:

• To develop an integrated workflow for the identification and quantification of HS and CS disaccharides from small, spatially resolved tissue sections.
• To enable detailed structural analysis of GAGs in specific regions of the mouse brain.

Main Methods:

• Integrated workflow combining laser microdissection (LMD), hydrophilic interaction liquid chromatography (HILIC), and cyclic ion mobility mass spectrometry (cIM-MS).
• Sequential enzymatic digestion of HS and CS chains from LMD-collected tissue sections.
• Quantitative analysis using linear calibration curves.

Main Results:

• Successfully identified and quantified common and rare HS and CS disaccharides, including saturated uronic acid residues and lyase-resistant tetrasaccharides.
• HILIC separated disaccharides by composition and hydrophilicity; cIM-MS resolved positional isomers.
• Quantitative data on disaccharide abundances from small-scale tissue sections were obtained.

Conclusions:

• The LMD-HILIC-cIM-MS workflow is effective for spatial GAGomics, providing detailed analysis of HS and CS.
• This method holds potential for biomarker discovery and advancing therapeutic applications by enabling site-specific GAG analysis.