Microheterogeneity and Individual Differences of Human Urinary N-Glycome under Normal Physiological Conditions

Area of Science:

• Biochemistry
• Analytical Chemistry
• Biomarker Discovery

Background:

• Urine is a rich source for biomarker discovery due to its reflection of systemic and urogenital physiology.
• Detailed analysis of urinary N-glycome is challenging due to low glycan abundance compared to free oligosaccharides.

Purpose of the Study:

• To thoroughly analyze and quantify the human urinary N-glycome using advanced LC-MS/MS techniques.
• To establish a reference profile for human urine N-glycans and their structural annotations.

Main Methods:

• N-glycans were released using hydrazine and labeled with 2-aminopyridine (PA).
• Anion-exchange fractionation was performed prior to LC-MS/MS analysis.
• Identification and quantification of N-glycans were conducted using LC-MS/MS.

Main Results:

• A total of 109 N-glycans were identified and quantified in urine.
• 58 N-glycans were consistently detected (≥80% of samples), representing ~85% of the total signal.
• Approximately 50% of the urinary N-glycome may originate from the kidney/urinary tract, with age and sex influencing N-glycan abundance.

Conclusions:

• This study provides the first comprehensive reference map of the human urine N-glycome.
• The findings offer insights into the origin of urinary N-glycans and their potential as biomarkers.
• Age and sex-dependent variations in the urine N-glycome highlight its dynamic nature.