Objective  To evaluate the effect and mechanism of terminal fucosylation inhibitor 2-deoxy-D-galactose (2-D-gal) on ciclosporin (CsA)-induced renal epithelial-mesenchymal transition (EMT).

  Methods  Fifteen male C57BL/6 mice aged 8-10 weeks were randomly and evenly divided into the control group (Ctrl group), CsA group and CsA+2-D-gal group (n=5). The expression levels of fucosyltransferase 1 (FUT1), EMT-associated proteins including E-cadherin, Vimentin, α-smooth muscle actin (α-SMA) in the kidney tissues of the Ctrl and CsA groups were detected by Western blot. The expression levels of terminal fucose in the kidney tissues of Ctrl and CsA groups were determined by immunofluorescence. The renal fibrosis of mice in each group was evaluated by Masson staining. The blood urea nitrogen and serum creatinine levels of mice in each group were detected. The in vitro EMT model of renal tubular epithelial cell HK2 was induced by CsA. HK2 cells were stimulated with 0, 2.5, 5.0 and 10.0 μmol/L CsA for 24 h, respectively. In addition, HK2 cells were divided into the Ctrl, 2-D-gal, CsA and CsA+2-D-gal groups. The morphology of HK2 cells after stimulation with different concentrations of CsA and in each group was observed. The expression levels of FUT1, E-cadherin, Vimentin and α-SMA in HK2 cells after stimulation with different concentrations of CsA and in each group were detected by Western blot. The expression level of terminal fucose in HK2 cells of the Ctrl and CsA groups was measured by immunofluorescence.

  Results  Compared with the Ctrl group, the relative expression of E-cadherin protein was down-regulated, those of FUT1, Vimentin and α-SMA proteins were up-regulated (all P < 0.05), and that of terminal fucose in the mouse kidney tissues was up-regulated in the CsA group. Compared with the Ctrl group, the blood urea nitrogen and serum creatinine levels in the CsA and CsA+2-D-gal groups were up-regulated (all P < 0.05). Compared with the CsA group, the blood urea nitrogen and serum creatinine levels in the CsA+2-D-gal group were down-regulated (both P < 0.05). Compared with the Ctrl group, the collagen fiber deposition was increased and the relative expression of α-SMA protein was up-regulated in the mouse kidney tissues of CsA and CsA+2-D-gal groups (all P < 0.05). Compared with the CsA group, the collagen fiber deposition was decreased and the relative expression of α-SMA protein in the mouse kidney tissues was down-regulated in the CsA+2-D-gal group (both P < 0.05). With the increase of CsA concentration, the morphology of HK2 cells gradually became longer and thinner from original normal cobblestone shape, the relative expression levels of FUT1, Vimentin and α-SMA protein in HK2 cells were up-regulated, and that of E-cadherin protein was down-regulated in a concentration-dependent manner. Compared with the Ctrl group, the expression level of terminal fucose of HK2 cells was up-regulated in the CsA group. After CsA treatment combined with 2-D-gal intervention, the morphology of HK2 cells in the CsA+2-D-gal group was restored to resemble that of normal HK2 cells. Compared with the CsA group, the relative expression of E-cadherin protein in HK2 cells was up-regulated, whereas those of Vimentin and α-SMA proteins were down-regulated in the CsA+2-D-gal group (all P < 0.05).

  Conclusions  CsA may induce EMT both in vivo and in vitro, and the terminal fucosylation is increased. 2-D-gal may inhibit CsA-induced EMT by suppressing the terminal fucosylation.