Comprehensive Analytical Approach toward Glycomic Characterization and Profiling in Urinary Exosomes.

Area of Science:

• * Glycomics and Proteomics
• * Extracellular Vesicle Biology
• * Biomarker Discovery

Background:

• * Exosomes are nanosized extracellular vesicles involved in intercellular communication.
• * While exosomal proteins and nucleic acids are studied for cancer biomarkers, their glycoconjugate content remains largely unexplored.
• * Understanding exosome glycosylation is crucial for their application in diagnostics.

Purpose of the Study:

• * To comprehensively analyze the N-glycan and O-glycan structures of exosomes isolated from normal human urine.
• * To establish detailed glycomic profiles of urinary exosomes using advanced mass spectrometry techniques.
• * To identify potential glycan biomarkers on exosomes.

Main Methods:

• * Isolation of exosomes from normal urine via multistep differential centrifugation.
• * Enzymatic release of N-glycans and chemical release of O-glycans from isolated exosomes.
• * Analysis using MALDI mass spectrometry, LC/MS-MS, and porous graphitized carbon (PGC) chromatography for detailed glycan structure elucidation and isomeric separation.

Main Results:

• * Identification of paucimannosidic, high-mannose, and complex N-glycans with determined relative abundances.
• * Detailed structural analysis of N-glycans, including minor multiantennary and sulfated glycans, through microfractionation and advanced LC/MS-MS techniques.
• * Characterization of unusual O-glycan structures from urinary exosomes.

Conclusions:

• * Urinary exosomes possess a complex repertoire of N- and O-glycans, including novel structures.
• * Advanced glycomic analysis provides a deeper understanding of exosome composition.
• * Detailed exosomal glycan profiling may lead to the discovery of new diagnostic biomarkers.