[Effects of silencing transforming growth factor-beta1 by RNAi upon transdifferentiation of renal allograft tubular epithelial cells in rats].

Objective: To investigate the effects of shRNA-transforming growth factor (TGF)-beta1 plasmid upon epithelial-myofibroblast transdifferentiation of renal allograft in rats.

Methods: Divided the Wistar rats into 4 groups: Group J (sham-operated group), T (plasmid group), H (vacant plasmid group) and Y (simply transplantation group). The SD to Wistar rat transplant kidney-sclerosis accelerated model was constructed and transfected with the plasmid based on hydromechanics. Transplanted kidneys were collected at Months 1, 2 and 3 post-transplantation. The gene transcriptional levels of TGF-beta1 and E-cadherin were detected by RT-PCR and the protein variation of E-cadherin was examined by Western blotting. The pathological changes and infiltrated inflammatory cells were assessed by HE staining and the immunohistochemical staining of E-cadherin and alpha-SMA used to label epithelial cells and fibroblast in order to exhibit cell transdifferentiation.

Results: Compared with Group H and Y, the mRNA transcription of TGF-beta1 was obviously inhibited in the Group T: at Month 3, the TGF-beta1 mRNA of Group T is 0.73 +/- 0.08, significantly lower than Group H and Y (0.92 +/- 0.07 and 0.95 +/- 0.04, both P < 0.01); the expression of E-cadherin was maintained at a high level: at the Month 3, the E-cadherin mRNA of Group T is 0.39 +/- 0.11, significantly higher than Group H and Y (0.15 +/- 0.07, and 0.17 +/- 0.06, both P < 0.01); the E-cadherin protein of Group T is 0.38 +/- 0.08, significantly higher than group H and Y (0.15 +/- 0.07 and 0.15 +/- 0.07, both P < 0.01); epithelial cells were much more and fibroblast was much less than that of Group H and Y; there were also less infiltrated chronic inflammatory cells and extracellular matrix deposition in the Group T.

Conclusion: The shRNA-TGF-beta1 plasmid can inhibit the epithelial-myofibroblast transdifferentiation of renal allograft in rats. The mechanisms may be associated with its effects of down-regulating TGF-beta1 and up-regulating E-cadherin.