Candidate genes involved in the defunctionalization and refunctionalization of the urinary bladder induced by bladder anuria and reperfusion.

AIMS We develop a novel rabbit urinary diversion model of bladder defunctionalization due to bladder anuria followed by refunctionalization due to urine reperfusion to investigate the molecular biological background. To validate the results, we used reverse transcription-polymerase chain reaction (RT-PCR) to analyze human specimens from defunctionalized bladders in patients receiving dialysis before kidney transplantation. METHODS Female rabbits were divided into three groups: control, defunctionalized, and refunctionalized. The bilateral ureters were anastomosed to vagina in the defunctionalized and refunctionalized groups at 0 weeks. In the refunctionalized group, the unilateral ureter was reanastomosed to the bladder at 8 weeks. RESULTS The capacity and compliance of the rabbit bladder in the refunctionalized group were significantly lower than those in the control group at 8 weeks and higher than those in the defunctionalized group at 14 weeks. The significant downregulation of IGFBP2, UPK1B, and CST6 in the defunctionalized group compared with that in the control groups, and the significant downregulation of AGTR2 in the refunctionalized group compared with that in the defunctionalized group in the rabbit bladder-muscle DNA microarray were validated by RT-PCR. Human bladder muscle indicated significant downregulation of UPK1B and CST6 and significant downregulation of IGFBP2 in the defunctionalized group, which is consistent with both rabbit bladder-muscle DNA microarray and rabbit bladder RT-PCR results. CONCLUSIONS The present study using novel model of bladder defunctionalization followed by refunctionalization indicated the consistent downregulation of UPK1B and CST6 in muscle and the consistent downregulation of IGFBP2 in mucosa in process of bladder defunctionalization, which was validated by human specimens.