[Effects of tanshinone IIA on Wnt/beta-catenin signaling pathway of high glucose induced renal tubular epithelial cell transdifferentiation].

OBJECTIVE: To observe the expressions of Wnt/beta-catenin and the effects of tanshinone IIA (TII A) on Wnt/beta-catenin signaling pathway in high glucose induced renal tubular epithelial cell transdifferentiation.

METHODS: Human kidney proximal tubular epithelial cells (HK-2) were divided into three groups, i. e., the normal glucose group, the high glucose group, and the high glucose plus tanshinone IIA group. The expression of beta-catenin was observed using immunocytochemical staining. The protein expression of beta-catenin, E-cadherin, and alpha-smooth muscle actin (alpha-SMA) were detected by Western blot. The mRNA levels of beta-catenin and E-cadherin were detected by RT-PCR.

RESULTS: Compared with the normal glucose group, both the protein and the mRNA expressions of beta-catenin were significantly enhanced (P < 0.01), the expression of E-cadherin significantly decreased (P < 0.01), the expression of beta-catenin increased in the cytoplasm and nucleus in the high glucose group. TIIA at the final concentration of 100 micromol/L significantly reduced the ectopic expression of beta-catenin. At that concentration, the protein and mRNA expressions of beta-catenin in the nucleus significantly decreased, while the protein and mRNA expressions of E-cadherin were up-regulated. Meanwhile, the expression of alpha-SMA obviously decreased.

CONCLUSIONS: Wnt/beta-catenin signaling pathway participated in the high glucose induced renal tubular epithelial cell transdifferentiation. TIIA inhibited the transdifferentiation process possibly through down-regulating the activities of Wnt/beta-catenin signaling pathway, thus further playing a role in renal protection.