Protein expression in vesicoureteral reflux: What about children?

Pathogenesis of vesicoureteral reflux (VUR) which concerns improper embryonal ureteric bud development still remains controversial, despite current studies have revealed several candidate genes. In this study, we aimed to determine the protein expression of certain genes which might play role in the pathogenesis of VUR, in the resected ureterovesical junction segments. The study group consisted of 19 children; 12(63%) girls, 7(37%) boys who had ureteroneocystostomy (UNC) operation; 3(15.7%) right sided, 7(36.8%) left sided, 9(47.3%) bilateral due to VUR. As a total, 28 ureterovesical junction segments were available for analysis of protein expressions of GDNF/RET, PAX2 and FGFR2 genes by their Western Blot analysis. Protein based expressions of FGFR2, PAX2 and RET were significantly lower than β-Actin (p = 0.001, for all proteins). Correlation analyses between grade of reflux and protein expressions revealed no significant relations (p>0.05, for all proteins). When we grouped the patients into 2 groups as high grade (grade 4–5) and low grade reflux (grade 1–3) for convenient analyses, no statistically significant difference was found between groups (p>0.05, for all proteins). Renal units were also grouped according to differential functions (≥40% and 0.05, for all proteins). Our study revealed decreased protein expressions of GDNF/RET, PAX2 and FGFR2 genes in the patients with VUR. Relation between clinical parameters and expression levels were statistically uncorrelated. Prospective studies of larger sample size are necessary in order to delineate the impact of certain proteins in the etiopathogenesis of VUR.