Abstract: Abstract:Objective To observe the effect of paired box gene 2 (PAX2) on the surface markers of renal tubular epithelial cells and induction of PAX2 on epithelial-mesenchymal transition (EMT) in vitro,and to provide basis for treatment of renal fibrosis. Methods The  rat normal renal tubular epithelial cell line NRK52E were divided into  control group,empty vector group(transfected with pGC-FU empty vector),and transfection group(transfected  with pGC-FU-GFP-PAX2 vector). The morphology of cells 72 h after transfection was evaluated by inverted phase contrast microscope. The expression levels of PAX2 protein and mRNA were evaluated by Western blotting and Real-time PCR methods.72 h after transfection,the expressions of E-cadherin and α-smooth muscle actin (α-SMA)  and their mRNA expressions were detected by  immunohistochemistry,Western blotting and Real-time PCR methods. Results 72 h after  tranfection of pGC-FU-GFP-PAX2,the fluorescence intensity   in transfection group was stronger than that in control group,and the shape of renal tubular epithelial cells  elongated.The  Western blotting results showed that the expression level of  PAX2 protein in transfection group was increased  compared with control and empty vector groups(P<0.05);the Real-time PCR results showed that  the expression level of PAX2 mRNA  in transfection group was increased  compared with control  group and empty vector group(P<0.05).The dyeing  of E-cadherin got weaker and the dyeing of α-SMA got stronger  in transfection group compared with control and  empty vector groups. The Western blotting results showed that the expression level of E-cadherin in transfection group was decreased and α-SMA was increased  compared with control and empty vector groups (P<0.05).The Real-time PCR results showed that the expression level of E-cadherin mRNA in transfection group was decreased and the expression level of α-SMA mRNA was increased in transfection group  compared with control and empty vector groups (P<0.05). Conclusion PAX2 transfection can reduce E-cadherin expression and increase α-SMA 　expression. PAX2 may  induce renal tubular mesenchymal transition in vitro.

Key words: paired box gene 2, renal tubular epithelial cells, transition, gene transfer