Abstract: Objective To investigate the expressions and mechanism of transforming growth factor-β1 (TGF-β1) and alpha smooth muscle actin (α-SMA) in autosomal dominant polycystic kidney disease (ADPKD). Methods According to the preoperative glomerular filtration rate (GFR) of abnormal kidney, 62 ADPKD patients were divided into two groups: high GFR group (group A, n=29), and low GFR group (group B, n=33). Another 20 patients treated with radical nephrectomy were chosen as controls(the control group). Kidney tissues from patients in groups A and B, and tumor-adjacent tissues from the controls were collected. Expressions of TGF-β1 and α-SMA of the three groups were detected with immunohistochemical method. Results TGF-β1 and α-SMA were positively expressed in groups A and B, with cord-like or patch-like distribution in the renal interstitial fibrosis area. No significant expression was found in the control group. The positive expression rate of α-SMA in groups A and B was statistically significant (P<0.05). The expressions of TGF-β1 and α-SMA were positively correlated (P<0.05). Conclusion TGF-β1 and α-SMA are highly expressed in ADPKD, both of which promote epithelial-to-mesenchymal transition, leading to renal fibrosis.

Key words: Renal fibrosis, Transforming grow factor-beta, Epithelial-to-mesenchymal transition, Autosomal dominant polycystic kidney disease, α-smooth muscle actin