title: Decrease of renal aquaporins 1-4 is associated with renal function impairment in pediatric congenital hydronephrosis.
abstract: BACKGROUND
  Renal aquaporins (AQP1-4) concentration is downregulated and is in proportion to the degree of hydronephrosis graded by ultrasound in pediatric congenital hydronephrosis (CH). However, the relationship between the expression of AQP1-4 with the changes of renal function impairment (RFI) evaluated by (99m)Tc-DTPA renal dynamic imaging is still unclear. This study aimed to investigate the relationship between AQP1-4 expression and degree of RFI in children with CH.
  
  
  METHODS
  The expression of AQP1-4 was evaluated in 45 children with unilateral ureteropelvic junction obstruction (28 boys and 17 girls, average age: 28±10 months) and 15 children undergoing nephrectomy for nephroblastoma (8 boys and 7 girls, average age: 26±8 months) by immunoblotting and immunohistochemistry. Renal function was graded into mild and severe RFI by (99m)Tc-DTPA renal dynamic imaging.
  
  
  RESULTS
  One-way analysis of variance with Bonferonni's correction showed a significantly reduced protein expression of AQP1-4 in the severe RFI group compared with those in both mild RFI group and controls (AQP1: 0.52±0.09 vs. 0.91±0.06 vs. 1.23±0.033; AQP2: 0.68±0.12 vs. 1.09±0.06 vs. 1.52±0.08; AQP3: 0.59±0.16 vs. 0.94±0.08 vs. 1.31±0.07; AQP4: 0.64±0.06 vs. 1.14±0.07 vs. 1.61±0.07; P<0.001, respectively). In kidneys with severe RFI, there was a reduction in the protein concentration of all four AQP isoforms which was more pronounced compared with those seen in kidneys with mild RFI and in the controls.
  
  
  CONCLUSIONS
  AQP1-4 expression is reduced in proportion with the impairment degree of renal function graded by (99m)Tc-DTPA renal dynamic imaging in human CH.
authors.affiliation: The Institute of Clinical Medicine, First Affiliated Hospital of Zhengzhou University, Zhengzhou, China.
authors.forename: Zhen-Zhen
authors.initials: ZZ
authors.lastname: Li
authors.forename: Lu
authors.initials: L
authors.lastname: Xing
authors.forename: Zhan-Zheng
authors.initials: ZZ
authors.lastname: Zhao
authors.forename: Jin-Sheng
authors.initials: JS
authors.lastname: Li
authors.forename: Rui
authors.initials: R
authors.lastname: Xue
authors.forename: Avinash
authors.initials: A
authors.lastname: Chandra
authors.forename: Rikke
authors.initials: R
authors.lastname: Nørregaard
authors.forename: Jian-Guo
authors.initials: JG
authors.lastname: Wen
mesh_terms: D051398:Aquaporin 1 / Q000378:metabolism; D051399:Aquaporin 2 / Q000378:metabolism; D051400:Aquaporin 3 / Q000378:metabolism; D051401:Aquaporin 4 / Q000378:metabolism; D020346:Aquaporins / Q000378:metabolism*; D002675:Child, Preschool; D005260:Female; D006801:Humans; D006869:Hydronephrosis; D007223:Infant; D007668:Kidney / Q000503:physiopathology*; D007680:Kidney Neoplasms / Q000378:metabolism* / Q000503:physiopathology; D008297:Male; D014517:Ureteral Obstruction / Q000378:metabolism* / Q000503:physiopathology; D009396:Wilms Tumor / Q000378:metabolism* / Q000503:physiopathology
chemical_list: D051399:Aquaporin 2; D051401:Aquaporin 4; D020346:Aquaporins; D051398:Aquaporin 1; D051400:Aquaporin 3