Introduction
Urine is an important specimen for biomarker discovery and health monitoring due to easy and noninvasive accesses. As a part of human urine proteomics, children’s samples are also important. Since kidney functions develop fast in young ages, we focus on comparative urinary quantitative proteomics of children and adults to clear age, gender or individual variance.
Methods
16 urine samples of 4 to 13-year-old children and 50 urine samples of 20’s to 70’s healthy volunteers were collected. Pre-centrifuged urine samples were stored at -20C until protein preparation. Purified tryptic peptides each was analyzed in IDA and DIA methods alternately. Protein Identification (ID) done by against SWISSPROT human database. SWATH-MS data processing was set as 6 peptides / protein, 6 transitions / peptide with at least 95% confidence threshold. Valve of each protein normalized by summed intensity value of all proteins in ppm level. Quality and quantitative proteomics between 2 groups were compared in gender and ages respectively.
Results
Protein concentration of urine was variable in all ages and no relationship with gender. In current, ~1,200 protein groups in children and ~2,000 protein groups in adults were identified in total. Some proteins with high expression observed in urine of children and some in girls also show a similar trend in adult females. As high expression proteins in boy’s samples, most of them are binding proteins and catalytic activity proteins, 1/3 of them are related to cellular biological process. It may show the high level of such process in young male at the age of 5-13.
Conclusions
Urine protein information of young age may be one of important references to support more precision identification of urine biomarker for disease detection and health monitoring for children in future.