The Urinary Proteomics Study In Unilateral UPJO Patients

ObjectivesUreteropelvic junction obstruction is a common obstructive disease that can result in hydronephrosis.Surgery is an approach to release obstruction.However,it is still controversial in identifying which children require surgical intervention versus observation.Tandem mass tag(TMT)and liquid chromatography-tandem mass spectrometry(LC-MS/MS)were applied to identify and analyze the differences of protein profiles in urine between unilateral UPJO patients with DRF<40% and normal controls in this study,aiming to find ideal urinary biomarkers which involved in the pathogenesis of UPJO.Methods1.Bladder urine and pelvic urine of unilateral UPJO patients with DRF<40% were collected.Urine of sex and age matched normal controls were also collected.These urine samples were defined as UPJO bladder urine group(BU),UPJO pelvic urine group(PU)and normal controls urine(CON).Urine samples were analyzed by LC-MS/MS.The protein identification was searched in the database of Swissprot Human with the help of Proteome Discoverer 2.2.2.Bioinformatics analysis was performed to analyze the role and function of identified urinary proteins,including GO analysis and COG analysis.GO enrichment and pathway analysis were also performed for common differentially expressed urinary protein.3.The differentially expressed proteins which were selected as potential biomarkers were validated by Western blot.Results1.By TMT labeling in conjunction with LC-MS/MS,finally,we identified and quantified a total of 1130 proteins,6922 peptides sequences.Proteins with a fold change of at least 1.3 and P-values less than 0.05 were considered statistically significant proteins.Out of which 81 and 186 significantly changed in the UPJO BU and PU groups,respectively,compared with the normal control group.50 proteins overlaps existed between these two sets of statistically significant proteins.Bioinformatics analysis showed that biological processes associated with the 50 common proteins panel were phagocytosis,transport,inflammatory response,signaling pathway.2.The Western blot results showed the significant increasing level of 5 selected differentially expressed proteins,including AGP1,AGP2,Fetuin-A,PGDS and protein AMBP in the UPJO BU and UPJO PU groups,compared with the normal control group.Conclusions1.This research used TMT quantitative proteomics technology to screen urinary biomarkers both in bladder urine and ipsilateral pelvic urine of unilateral UPJO patients with DRF <40%.We established a database of differential urinary proteins of unilateral UPJO patients with DRF <40%.2.The research showed that 5 proteins(AGP1,AGP2,Fetuin-A,PGDS and protein AMBP)may be the potential urinary biomarker of UPJO,and the pathogenesis of UPJO should be studied further by these proteins in the future.