RESUMO
Objective To investigate the expression pattern of microRNA (miRNA) in the kidneys of unilateral ureteral obstruction (UUO) rats and to identify specific miRNA related to renal interstitial fibrosis (RIF).Methods Forty-eight male SD rats were divided into two groups:UUO group and sham-operated (Sham) group.Rats were sacrificed at 3,7 and 14 days after operation.Histologic changes were examined by Masson staining.Forty-eight selected miRNAs were examined by stem-loop real-time qPCR.Results At the 3rd day after operation,obstructed kidneys from operation rats showed mild edema in the interstitium and mononuclear cell infiltration.At the 7th day after operation,focal interstitial fibrosis was observed.At the 14th day after operation,fibrosis became more severe.The Sham kidneys showed no pathological changes.At the 3th day after operation,25 miRNAs were differentially expressed.At the 7th day after operation,24 miRNAs were aberrantly expressed,whereas 21 miRNAs were differentially expressed at the 14th day after operation (P＜0.05).Among these miRNAs,miR-132,miR-192,miR-194,miR-29c and miR-203 were consistently up-regulated or down-regulated in a time-dependent manner after operation.There were significantly correlations between the expression of five miRNAs and severity of tubulointerstitial injury (P＜0.05).Conclusions There are at least 20 miRNAs differentially expressed in the process of RIF induced by UUO.There are significantly correlations between the expression of miR-132,miR-192,miR-194,miR-29c and miR-203 and the severity of tubulointerstitial injury.They may be closely related to RIF.A further study is needed.