Role of connective tissue growth factor in high glucose-induced epithelial-mesenchymal transition in podocytes

AIM: To investigate the role of connective tissue growth factor (CTGF) in high glucose-induced epithelial-mesenchymal transition (EMT) in podocytes. METHODS: The differentiated podocytes cultured under different conditions for 24 h at 37 ℃ were divided into 4 groups: control (5 mmol/L glucose solution), 5 mmol/L glucose solution supplemented with 50 μg/L CTGF, high glucose (30 mmol/L glucose solution) and high glucose supplemented with CTGF (50 μg/L). The morphology of cultured podocytes was observed under phase-contrast microscope. To study the relevant markers of EMT, the mRNA and protein expression was analyzed by real-time RT-PCR and Western blotting, respectively. In addition, the effect of CTGF inhibition with anti-CTGF antibody on high glucose-induced EMT in podocytes was investigated. RESULTS: High glucose induced phenotypic transition in the podocytes from an arborization morphology to a cobblestone morphology. After addition of CTGF to high glucose culture, the podocytes developed a feature of spindle. Under high glucose condition, podocytes underwent EMT, as the epithelial marker (nephrin) was decreased and the mesenchymal marker (desmin) was increased. Exogenous CTGF showed the effect of synergy on high glucose-induced EMT. Moreover, high glucose-induced EMT in podocytes was prevented by CTGF inhibition with anti-CTGF antibody. CONCLUSION: CTGF is involved in high glucose-induced EMT in podocytes. Inhibition of CTGF might prevent podocytes from injury in diabetes.