Quantitative comparison of the renal pelvic urine and bladder urine to examine modifications of the urine proteome by the lower urinary tract

• Published in: Proteomics. Clinical applications Vol. 18; no. 2; pp. e2300004 - n/a
• Main Authors: Pan, Yilin, Wong, Christine Yim‐Ping, Ma, Haiying, Tse, Ryan Tsz‐Hei, Cheng, Carol Ka‐Lo, Tan, Miaomiao, Chiu, Peter Ka‐Fung, Teoh, Jeremy Yuen‐Chun, Wang, Xin, Ng, Chi‐Fai, Zhang, Liang
• Format: Journal Article
• Language: English
• Published: Germany Wiley Subscription Services, Inc 01.03.2024
• Subjects: Biomarkers; Bladder; bladder urine; Chromatography, Liquid; Design of experiments; Exosomes; Humans; Hydroxyproline; Kidney Pelvis - chemistry; Kidney Pelvis - metabolism; Male; Pelvis; Peptides; Proteins; Proteome - analysis; Proteomes; Proteomics; Reabsorption; renal pelvic urine; Tandem Mass Spectrometry; Urinary Bladder - chemistry; Urinary Bladder - metabolism; Urinary tract; Urine; urine proteomics; Urogenital system; urothelial–urinary interactions; urine proteomics; renal pelvic urine; urothelial-urinary interactions; bladder urine
• ISSN: 1862-8346; 1862-8354
• DOI: 10.1002/prca.202300004

Purpose Urine proteome is a valuable reservoir of biomarkers for disease diagnosis and monitoring. Following formation as the plasma filtrate in the kidney, urine is progressively modified by the active reabsorption and secretion of the urinary tract. However, little is known about how the urine proteome changes as it passes along the urinary tract. Experimental design To investigate this, we compared the proteome composition of the renal pelvis urine (RPU) and individually self‐voided bladder urine (BU) collected from seven unilateral urinary tract obstruction male patients by LC‐MS/MS screening. To our knowledge, this is the first proteomic comparison of RPU and BU samples from the same individual. Results Overall, RPU and BU proteomes did not exhibit proteins that were exclusively present in all samples of one urine type while in none of the other type. Nonetheless, BU had more overrepresented proteins that were observed at a higher frequency than RPU. Label‐free quantitative analyses revealed BU–RPU differential proteins that are enriched in exosomes and extracellular proteins. However, the differences were not significant after corrections for multiple testing. Interestingly, we observed a significant increase of collagen peptides with hydroxyproline modifications in the BU samples, suggesting differences in protein modifications. Conclusions and clinical relevance Our study revealed no substantial differences at the protein level between the BU and RPU samples. Future investigations with expanded cohorts would provide more insights about the urothelial–urinary interactions.