Renal expression of epidermal growth factor and transforming growth factor-beta 1 in children with congenital hydronephrosis

Abstract

Objectives To study the potential role of pelviureteral junction obstruction (PUJO) in causing progressive renal damage in children through the renal expression of epidermal growth factor (EGF) and transforming growth factor-beta 1 (TGF-β 1). Methods The expression of EGF and TGF-β 1 was evaluated in the renal tissues of 25 children with congenital hydronephrosis by immunohistochemistry, in situ hybridization, and reverse transcriptase polymerase chain reaction techniques. Results Children with PUJO had a significant increase in TGF-β 1 and a marked reduction in EGF expression compared with controls. The TGF-β 1/glyceraldehyde phosphate dehydrogenase ratio in the hydronephrotic kidney and normal kidney was 0.53 ± 0.13 and 0.24 ± 0.10 respectively, and the difference was significant ( P = 0.000). The EGF/glyceraldehyde phosphate dehydrogenase ratio in the hydronephrotic kidney and normal kidney was 0.15 ± 0.06 and 0.55 ± 0.13, respectively, and the difference was also significant ( P = 0.0001). Positive correlations were found between the TGF-β 1 gene and the drainage clearance half-time ( r = 0.47; P = 0.018), TGF-β 1 protein and drainage clearance half-time ( r = 0.44; P = 0.028), TGF-β 1 gene and histologic grade ( r = 0.53; P = 0.006), and TGF-β 1 protein and histologic grade ( r = 0.76; P = 0.000). Negative correlations were found between the EGF gene and drainage clearance half-time ( r = −0.59; P = 0.002), EGF protein and drainage clearance half-time ( r = −0.61; P = 0.001), EGF gene and histologic grade ( r = −0.58; P = 0.003), and EGF protein and histologic grade ( r = −0.47; P = 0.019). Conclusions TGF-β 1 expression was increased and EGF expression was decreased in the renal tissue after clinical PUJO. The alterations of TGF-β 1 and EGF may play a potential role in the pathogenesis of renal damage in PUJO.