Microheterogeneity and Individual Differences of Human Urinary <i>N</i>-Glycome under Normal Physiological Conditions

oleh: Hend Zedan, Kousuke Morimura, Amr Elguoshy, Tadashi Yamamoto, Shunji Natsuka

Format: Article
Diterbitkan: MDPI AG 2023-04-01

Deskripsi

Urine is considered an outstanding biological fluid for biomarker discovery, reflecting both systemic and urogenital physiology. However, analyzing the <i>N</i>-glycome in urine in detail has been challenging due to the low abundance of glycans attached to glycoproteins compared to free oligosaccharides. Therefore, this study aims to thoroughly analyze urinary <i>N</i>-glycome using LC-MS/MS. The <i>N</i>-glycans were released using hydrazine and labeled with 2-aminopyridine (PA), followed by anion-exchange fractionation before LC-MS/MS analysis. A total of 109 <i>N</i>-glycans were identified and quantified, of which 58 were identified and quantified repeatedly in at least 80% of samples and accounted for approximately 85% of the total urinary glycome signal. Interestingly, a comparison between urine and serum <i>N</i>-glycome revealed that approximately 50% of the urinary glycome could originate from the kidney and urinary tract, where they were exclusively identified in urine, while the remaining 50% were common in both. Additionally, a correlation was found between age/sex and the relative abundances of urinary <i>N</i>-glycome, with more age-related changes observed in women than men. The results of this study provide a reference for human urine <i>N</i>-glycome profiling and structural annotations.