Comparative Proteome Analyses of Ureteropelvic Junction Obstruction and Surrounding Ureteral Tissue

Abstract

Ureteropelvic junction (UPJ) obstruction is a common problem in children, but its etiology remains unclear. In this study, the proteome profiles of the obstructed segment and its surrounding distal and proximal parts were comparatively evaluated. Twelve children younger than 2 years of age with unilateral intrinsic UPJ obstruction were included. The excised operational tissue was divided into three parts immediately after resection: the obstructed part (Obst), the distal normal ureteral part (Dist), and the proximal part of the obstructed segment (Prox). Proteins extracted from the tissue samples were subjected to two-dimensional gel electrophoresis analysis to identify differentially regulated proteins. Spot analysis revealed that four proteins, namely tropomyosin beta and alpha-1 chains, actin and desmin, were upregulated in Obst in comparison to Dist. A similar analysis between Obst and Prox showed that heat shock protein beta-1 and carbonic anhydrase-1 were upregulated in Obst, while tropomyosin alpha 3 chain and ATP synthase beta were upregulated in Prox. The last comparative analysis between Dist and Prox revealed upregulation of annexin-A5 and annexin-A1 in Dist and vimentin, mitochondrial ATP synthase subunit-beta, peroxiredoxin-2, and apolipoprotein-A1 in Prox. Bioinformatics analysis using the STRING server indicated that the differentially regulated proteins, altogether, point to the changes occurring in muscle filament sliding pathway. When regulations occurring in each group were mutually compared, a change in lipase inhibition activity was detected by STRING. This is the first study scrutinizing changes occurring in protein profiles in UPJ.